SMU MBA 3RD SEM ASSIGNMENT SET-2

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MI0033 – SOFTWARE ENGINEERING
Q1. Write a note on myths of Software.
ANSWER:

ASSIGNMENT - SET- 2

Myth is defined as "widely held but false notation" by the oxford dictionary, so assign other fields software arena also has some myths to demystify. Pressman insists “Software myths- beliefs about software and the process used to build it- can be traced to earliest days of computing. Myths have anumber of attributes that have made them insidious." So software myths prevail but though they do are not clearly visible they have the potential to harm all the parties involved in the software development process mainly the developer team. Tom DeMarco expresses “In the absence of meaningful standards, a new industry like software comes to depend instead on folklore." The given statement points out that the software industry caught pace just some decades back so it has not matured to formidable level and there are no strict standards in software development. There does not exist one best method of software development that ultimately equates to the ubiquitous software myths. Primarily, there are three types of software myths, all the three are stated below: 1.Management Myth2.CustomerMyth3.Practitioner/Developer Myth before defining the above three myths one by one lets scrutinize why these myths occur on the first place. The picture below tries to clarify the complexity of the problem of software development requirement analysis mainly between the developer team and the clients.

Q2. Explain Version Control & Change Control.
ANSWER:

Version Control & Change Control. A version control system (or revision control system) is a combination of technologies and practices fort racking and controlling changes to a project's files, in particular to source code, documentation, andweb pages. If you have never used version control before, the first thing you should do is go find someone who has, and get them to join your project. These days, everyone will expect at least your project‟s source code to be under version control, and probably will not take the project seriously if it doesn‟t use version control with at least minimal competence. The reason version control is so universal is that it helps with virtually every aspect of running a project: inter-developer communications, release management, bug management, code stability and experimental development efforts, and attribution and authorization of changes by particular developers. The version control system provides a central coordinating force among all of these areas. The core of version control is change management: identifying each discrete change made to theproject's files, annotating each change with metadata like the change's date and author, and then replaying these facts to whoever asks, in whatever way they ask. It is a communications mechanism where a change is the basic unit of information. This section does not discuss all aspects of using a version control system. It's so all-encompassing that it must be addressed topically throughout the book. Here, we will concentrate on choosing and setting upa version control system in a way that will foster cooperative development down the road.

Q3. Discuss the SCM Process.
ANSWER:

In software engineering, software configuration management (SCM) is the task of tracking and controlling changes in the software. Configuration management practices include revision control and the establishment of baselines.SCM concerns itself with answering the question "Somebody did something, how can one reproduce it?"Often the problem involves not reproducing "it" identically, but with controlled, incremental changes. Answering the question thus becomes a matter of comparing different results and of analyzing their differences. Traditional configuration management typically focused on controlled creation of relatively simple products. Now, implementers of SCM face the challenge of dealing with relatively minor increments under their own control, in the context of the complex system being developed. According to another simple definition: Software Configuration Management is how you control the evolution of software project.

The goals of SCM          Configuration identification - Identifying configurations, configuration items and baselines. Configuration control - Implementing a controlled change process. This is usually achieved by setting upa change control board whose primary function is to approve or reject all change requests that are sentagainst any baseline. Configuration status accounting - Recording and reporting all the necessary information on the status of the development process. Configuration auditing - Ensuring that configurations contain all their intended parts and are sound withrespect to their specifying documents, including requirements, architectural specifications and usermanuals. Build management - Managing the process and tools used for builds. Process management - Ensuring adherence to the organization's development process. Environment management - Managing the software and hardware that host the system. Teamwork - Facilitate team interactions related to the process. Defect tracking - Making sure every defect has traceability back to the source.

Q4. Explain i. Software doesn’t Wear Out.
ANSWER:

ii. Software is engineered & not manufactured.

Software doesn‟t Wear Out.
The hardware can wear out whereas software can't. In case of hardware we have a "bathtub “like curve, which is a curve that lies in between failure-rate and time. In this curve, in the starting time there is relatively high failure rate. But, after some period of time, defects get corrected and failure-rate drops to a steady-state for some time period. But, the failure-rate again rises due to the effects of rain, dust, temperature extreme and many other environment effects. The hardware begins to wear out. But, the software is not responsible to the failure rate of hardware. The failure rate of software can be understood by the "idealized curve". In this type of curve the failure rate in the initial state is very high. But, the errors in the software get corrected and the curve flattens. However, the implication is clear that the software can "deteriorate" it does not "wear out”. This can be explained by the actual curve. As soon as that error gets corrected the curveencounters another spike that means another error in the software. After some time the steady state of the software don't remains steady and the failure rate begins to rise. If hardware getsfailed then it can be replaced but there is no replacement in case of software. Software is engineered & not manufactured. The roadmap to building high quality software products is software process.  Software processes are adapted to meet the needs of software engineers and managers as they undertake the development of a software product.  A software process provides a framework for managing activities that can very easily get out of control.  Different projects require different software processes.  The software engineer's work products (programs, documentation, data) are produced as consequences of the activities defined by the software process.  The best indicators of how well a software process has worked are the quality,timeliness, and long-term viability of the resulting software product.

Q5.Explain the Different types of Software Measurement Techniques.
ANSWER:

Most estimating methodologies are predicated on analogous software programs. Expert opinion is based on experience from similar programs; parametric models stratify internal data based to simulate environments from many analogous programs;engineering builds reference similar experience at the unit level; and cost estimating relationships like parametric models regress algorithms from several analogousprograms. Deciding which of these methodologies or combination or methodlogies is the most appropriate for your program usually depends on availability of data. Which is inturn depends on where you are in the life cycle or your scope definition. Analogies. Cost and schedule are determined based on data from competed similar efforts. When applying this method, it is often difficult to find analogous efforts at the total system level. It may be possible, however, to find analogous efforts at the subsystem or lower level computer software configuration item/computer software component/computer software unit (CSCI/CSC/CSU). Furthermore, You may be able to find completed efforts that are

more or less similar in complexity. If this is the case, a scaling factor may be applied based on expert opinion. After an analogous effort hasbeen found. Associated data need to be assessed. It is prefereable to use effort rather than cost data; however, if only cost data are available, these costs must be normalized to the same base year as your effort using current and appropriate inflation indices. As with all methods, the quality of the estimate is directly proportional to the credibility of the data. Expert (Engineering opinion). Cost and schedule are estimated by determining requiredeffort based on input from personnel with extensive experience on similar programs. Due to the inherent subjectivity of this method, it is especially important that input from several independent sources be used. It is also important to request only effort data rather than cost.

Q6. Write a Note on Spiral Model.
ANSWER:

The spiral model, also known as the spiral lifecycle model, is a systems development lifecycle (SDLC) model used in information technology (IT). This model of development combines the features of the prototyping model and the waterfall model. The spiral model is favored for large, expensive, and complicated projects. The steps in the spiral model can be generalized as follows:
The new system requirements are defined in as much detail as possible. This usually involves interviewing a number of users representing all the external or internal users and other aspects of the existing system. 2. A preliminary design is created for the new system. 3. A first prototype of the new system is constructed from the preliminary design. This is usually a scaled-down system, and represents an approximation of the characteristics of the final product. 4. A second prototype is evolved by a fourfold procedure: (1) evaluating the first prototype in terms of its strengths, weaknesses, and risks; (2) defining the requirements of the second prototype; (3) planning and designing the second prototype; (4) constructing and testing the second prototype. 5. At the customer's option, the entire project can be aborted if the risk is deemed too great. Risk factors might involve development cost overruns, operating-cost miscalculation, or any other factor that could, in the customer's judgment, result in a less-than-satisfactory final product. 6. The existing prototype is evaluated in the same manner as was the previous prototype, and, if necessary, another prototype is developed from it according to the fourfold procedure outlined above. 7. The preceding steps are iterated until the customer is satisfied that the refined prototype represents the final product desired. 8. The final system is constructed, based on the refined prototype. The final system is thoroughly evaluated and tested. Routine maintenance is carried out on a continuing basis to prevent large-scale failures and to minimize downtime. 1.

MI0034 – DATABASE MANAGEMENT SYSTEM
Q1. Define Data Model & discuss the categories of Data Models? What is the difference between logical data Independence & Physical Data Independence?
ANSWER Data Model : 1. It is a set of Concepts for viewing a set of data in a structured way. 2. This can be easily understood by professionals and nontechnical users. 3. It can explain the way in which the organization uses and manages the information.

ASSIGNMENT - SET- 2

Categories of Data Model:
Entity An entity is something that has a distinct, separate existence, though it need not be of a material existence. E.g. – Employee. Attribute It is the property that describes an entity It is a characteristic or property of an object, such as weight, size, or color Relationship: Describes the relationship between two or more entities. Logical data independence: This is the ability to modify the conceptual scheme without causing application programs to be rewritten. This is usually done when the logical structure of database is altered. Logical data independence is harder to achieve, as the application programs are usually heavily dependent on the logical structure of the data. An analogy is made to abstract data types in programming languages. Physical data independence: This is the ability to modify the physical scheme without causing application programs to be rewritten. Modifications at this level are usually to improve performance.

Q2. What is a B+Trees? Describe the structure of both internal and leaf nodes of a B+Tree?
ANSWER A B+ tree is a multilevel index, but it has got different a structure. A typical node of the B+ tree contains upto n-1 search key values such as k1,k2…n-1 and n pointers p1,p2…pn. The search key values within anode are kept in sorted order, ki < kj. The number of pointers in a node is called the fan out of the node. The structure of a non-leaf node is the same as leaf nodes, except that all pointers are pointers to tree nodes. Each internal node is of the form >p1, k1,p2,k2.pq-1, kq-1, pq> The root node has at least 2 tree pointers. Each leaf node is of the form<<k1, pr1>,<k2, pr2><kn-1, prn-1>, pnext> each pri is a data pointer, and pnext points to the next leaf node of the B+ tree. All leaf nodes are at the same level. Consider an example, assume that we wish to insert a record in a B+ tree of order n=3 and pleaf=2, first we observe that root is the only node in the tree, so it is also a leaf node. As soon as more than one level is created, the tree is divided into

internal nodes and leaf nodes. Notice that every value must exist at the leaf level, because all the data pointers are at the leaf level. However, only some values exist in internal nodes to guide the search. Notice also that every value appearing in an internal node also appears in the sub tree as the rightmost value. Say for example, to insert 12, the node is split into two nodes. The figure shows the two leaf nodes that result from inserting 12. An existing node contains 7 and 8 and remaining value 12 in a new node. The first J = [((Pleaf+ 1)1/2)] = 3/2 = 2 entries in the original node are kept there and the remaining entries are moved to a new leaf node. The Jth search value is replicated in the parent internal node, and an extra pointer to the new node is created in the parent. If the parent internal node is full, it must be split. This splitting can propagate all the way up to create a new root node.

Q3. Describe Projection operation, Set theoretic operation & join operation?
ANSWER

Projection operation:
Projection operation is used to select only few columns from a table. The mathematical symbol p<ATTRIBUTE LIST>(<relation>)Here, <attribute list> is a list of attributes from the relation r hence the degree (number of columns) of the result is equal to the number of attributes specified in the attribute list. Eg 1. Select the name and salary of all the employees. pNAME. SALARY (EMPLOYEE).This query selected only name and salary attributes from relation EMPLOYEE Eg. 2. Select names and addresses of all employees working for department 10. pNAME, ADDRESS (DNO=10(EMPLOYEE). Set theoretic operations: These are used to merge the elements of two sets in various ways, including union, intersection and difference. Three of these operations require the table to be union compatible. The two relations are said to require the table to be union compatible. The two relations are said to be union compatible if the following conditions are satisfied. 1. The two relation/tables (say R & S) that have the same number of columns (have the same degree). 2. Each column of the first relation/table must be either the same data type as the corresponding column of the second relation/table(s).

Join Operation:
The join operation, denoted by is used to combine two relations to retrieve useful information. A join operation matches data from two or more tables; based on the values of one or more columns in each table, it allows us to process more than one table at a time. The general form of a Join operation is R<join condition>S For example by joining employee and department relations, we can get the name of the department in which the employee is working (department name exists in department table). Select emp_no, ename, dept.dname from emp.dept Where emp.deptno = dept.dept_no and emp_no = &emp_no. Emp_dept<--employee e.deptno=d.deptnoDEPT Result<-IIemp.enam,dname)emp_dept) The first operation in the joint operation will combine the tuples of the employee and department relationson the basis of the dept no.to form a relation called emp_dept. Then the PROJECT operation will create arelation RESULT with the attributes eno. Ename, and dname. To perform join between two relations,there should be a common field between them.

Theta Join:
A join condition is of the form<Condition>and<condition>and<condition>Where each condition is of the form Ai 0 Bj (dept.deptno = emp.dept_no). Ai is an attribute of R and Bj is an attribute of S. Ai and Bj have the same domain (same

values) and 0 is one of the comparison operators(=,<,<=,>,>=,!=).A join operation with such a general join condition is called a "Theta join".

Equi Join:
While joining if the comparison operator is = then it is equijoin.Eg. Select emp_no.ename.dept.dname from emp.dept.Where emp.deptno = dept.dept_no.

Natural Join:
The standard definition of natural join requires that the joinattributes have the same name in both relations. In general, natural join is performed by equating allattribute pairs that have the same name in the two relations. The general format is:

Outer join:
It returns both matching and non matching rows. It differs from the inner join, in that the rows in one table having no matching rows in the other table will also appear in the results table, with nulls in the other attribute position, instead of being ignored as in the case with the inner join. It outputs rows even if they do not satisfy the join condition; the outer join operator is used with the table having n matching rows.

Left outer join:
The left outer join operation keeps every tuple in the first or left relation R in relation

Right outer join:
Keeps every tuple in the second or right relation S in the result of R .

Full outer join:
Keeps all tuples in both the left and right relations and when no matching tuples are found, filled with null values as needed.

Q4. Discuss Multi Table Queries?
ANSWER SIMPLE EQUI-JOINS: When two tables are joined together we must follow these guidelines: Table names in the FROM clause are separated by commas. Use appropriate joining condition. This means that the foreign key of table 1 will be made equal to the primary key of table 2. This column acts as the joining attribute. For example, dno of employee table and dno of department will be involved in the joining condition of WHERE clause. EXAMPLE-1: This example demonstrates the equijoin and the purpose is to display the employee names and the department names for which they work. SELECT NAME, DNAMEFROM Employee, Department WHERE employee.Dno = department.Dno OUTPUT: NAME DNAME Prasad Accounts Reena Accounts Deepak Admin Venkat Accounts Pooja Research SELF JOIN and TABLE ALIASES: The self-join is one where you involve the same table in the join. This is illustrated in the following example. This technique is used fully to solve many queries. To find the employee who earns more than venkat. SELECT e1.name, e1.salary FROM Employee e1, Employee e2 WHERE (e1.salary > e2.salary) AND (e2.name = 'venkat')

OUT PUT: NAME SALARY Prasad 32000 OUTER JOINS: Outer joins are used to display rows that do not meet the join condition. For left outer join use a plus sign(+) to left condition and for right outer join use the plus sign to the right condition. The syntax for left and right outer joins is given below: Left outer join: SELECT table1.col, table2.col FROM table1 t1, table2 t2 WHERE t1.col (+) = t2.col; Notice that the plus sign cannot be placed on both sides of the condition. EXAMPLE: This example demonstrates the right outer join by retaining the right side table(department) tuples and giving null values for the tuples that do not match the left side table (employee). SELECT Name, Dname FROM Employee E, Department D WHERE E.Name(+) =D.Dname; OUTPUT: NAME DNAME Accounts Admin

Q5. Discuss Transaction Processing Concept? Describe properties of Transactions?
ANSWER Transaction Processing Concept: A transaction is an atomic unit comprised of one or more SQL statements. A transaction begins with the first executable statement and ends when it is committed or rolled back. Single User V/S Multi User systems: A DBMS is used if at most one user at a time can use the system. It is multi-user if many users can use the system and have access to the DB concurrently. For e.g.: An air line reservation system is used by 100‟s of travel agency and clerks concurrently. Multiple users can access databases and use computer systems simultaneously. Because of the concept of multiprogramming, this system executes some commands from one process than suspend that process, and executes some command from the next process. Therefore it is inter leaved. In a single user system one can execute at most one process at a time. The Read and Write operations and DBMS Buffers: A transaction is a logical unit of database processing that includes one or more database access operations (insertion, delet e etc). Only retrieving of data is called read only transaction. The basic database access operations are 1) Read-item (x)® It reads a database item named „x‟ into a program variable. 2) Write-item (x) ® writes the value of the program variable x into the database. Concurrent control: The data in the database must perform their transactions concurrently without violation the ACID (Atomicity, Consistency, Integrity and Durability) properties of a database. It takes place during the progression of an activity. It involves the regulation of ongoing activities that are part of transformation process to ensure that they confor m to organizational standards. Concurrency control solves the major issues involved with allowing multiple people simultaneous access to shared entities, and their object representations… Why concurrency control is needed: In a multiuser database, transactions submitted by the various users may execute concurrently and may update the same data. Concurrently executing transactions must be guaranteed to produce the same effect as serial execution of transactions [one by one]. Several problems can occur when concurrent transactions execute in

an uncontrolled manner, therefore the primary concern of a multiuser database includes how to control data concurrency and consistency. Data concurrency: Access to data concurrently (simultaneously) used by many users must be co-ordinates. Data consistency: A user always sees a consistent (accurate) view of all data committed by other transactions as of that time and all changes made by the user up to that time. Several problems can occur when concurrent transactions execute in an uncontrolled manner. Transaction states and additional operations: A transaction is an atomic unit of work that is entirely completed or not done at all. For recovery purpose the system needs to keep track of when the transaction starts, terminates, commits or aborts. Hence the recovery manager keeps track of the following operations. 1. Begin transaction: This marks the beginning of transaction execution, 2. Read/Write: These specify read/write operation execution. 3. End transaction: This specifies that the read and write transaction operations have ended, and marks the end of the transaction execution. At this point it maybe necessary to check whether the changes can be permanently applied to the DB or aborted. 4. Commit transaction: This signals a successful end of the transaction, so that any changes executed by the transaction can be committed to the DB. 5. Roll Back: This signals that the transactions has ended unsuccessfully, so that any changes that the transaction may have applied to the database must be undone. Properties of Transactions: To ensure data integrity, the database management system should maintain the following transaction properties. These are often called the ACID properties. 1. Atomicity: A transaction is an atomic unit of processing. It is either performed in its entirety (completely) or not performed at all. 2. Consistency: The basic idea behind ensuring atomicity is as follows. The database system keeps back of the old values of any data on which a transaction performs a write, and if the transaction does not complete its execution, the old values are restored to make it appear as though the transaction was never executed.

Q6. Describe the advantage of Distributed database? What is Client/server Model? Discuss briefly the security and Internet violation?
ANSWER

Advantages of Distributed Databases:
1. Increased reliability and availability: Reliability is broadly defined as the probability that a system isrunning at a certain time point, whereas reliability is defined as the system that is continuously availableduring a time interval. When the data and DBMS software are distributed over several sites, one site mayfail while other sites continue to operate. Only the data and software that exist at the failed site cannot beaccessed. In a centralized system, failure at a single site makes the whole system unavailable to all users. 2. Improved performance: Large database is divided into smaller databases by keeping the necessary data where it is needed most. Data localization reduces the contention for CPU and I/O services, and simultaneously reduces access delays involved in wide area network. When a large database is distributed over multiple sites, smaller databases exist at each site. As a result, local queries and transactions accessing data at a single site have better performance because of the smaller local databases. To improve parallel query processing a single large transaction is divided into a number of smaller transactions and executes multiple transactions at different sites. 3. Data sharing: Data can be accessed by users at other remote sites through the distributed database management system (DBMS) Software. Client-Server Model The Client-Server model is basic to distributed systems; it allows clients to make requests that are routed to the appropriate server in the form of transactions. The client-server model consists of three parts.

1. Client The client is the machine (workstation or pc) running the front and applications. It interacts with a user through the keyboard, display and mouse. The client has no direct data access responsibilities. The client machine provides frontend application software for accessing the data on the server. The clients initiates transactions, the server processes the transactions. Interaction between client and server might be processed as follows during processing of an SQL query. 1. The client passes a user query and decomposes it into a number of independent site queries. Each site query is sent to the appropriate server site. 2. Each server processes the local query and sends the resulting relation to the client site. 3. The client site combines the results of the queries to produce the result of the originally submitted query. So the server is called database processor or back end machine, where as the client is called application processor or front end machine. Another function controlled by the client is that of ensuring consistency of replicated copies of a data item by using distributed concurrency control techniques. The client must also ensure the atomicity of global transactions by performing global recovery when certain sites fail. It provides distribution transparency, which is the client hides the details of data distribution from the user. 1. Server : The server is the machine that runs the DMS software. It is referred to as back end. The server processes SQL and other query statements received from client applications. It can have large disk capacity and fast processors. 2. Network:The network enables remote data access through client server and server-to-server communication. Each computer in a network is a node, acts as a client, a server, or both, depending on the situation. Advantages: Client applications are not dependent on physical location of the data. If the data is moved or distributed to other database servers, the application continues to function with little or no modification. It provides multi-tasking and shared memory facilities; as a result they can deliver the highest possible degree of concurrency and data integrity. In networked environment, shared data is stored on the servers, rather than on all computers in the system. This makes it easier and more efficient to manage concurrent access. Inexpensive, low-end client work stations can access the remote data of the server effectively. Security and Integrity Violations Misuse of database can be categorized as being either intentional or accidental. Accidental loss of data consistency: 1. System crashes during transaction processing 2. Due to multi-users accessing the database. 3. Distribution of data over several computers. Intentional loss of data may be due to reading, writing or destruction of data by unauthorized users. Database security usually protects data by several techniques Certain portion [selected columns] of a database is available only to those persons who are authorized to access it. This ensures that the confidentiality of data is maintained. For e.g.: In large organizations, where different users may use the same database, sensitive information such as employees salaries should be kept confidential from most of the other users. To protect database we must take security measures at several levels. Network security is also important as database security. Security within the operating system is implemented by providing a password for the user accounts. It protects data in primary memory by avoiding direct access to the data.

MI0035 – COMPUTER NETWORKS
Q.1 Write down the features of Fast Ethernet and Gigabit Ethernet.
ANSWER:

ASSIGNMENT - SET- 2

Fast Ethernet : The basic idea behind fast Ethernet was simple: keep all the old frame formats, interfaces, and procedural rules, but just reduce the bit time from 100 nsec to 10 nsec.  100Base-T4 uses a signaling speed of 25 MHz, only 25 percent faster than standard Ethernet‟s 20 MHz. However, to achieve the necessary bandwidth, 100Base-T4 requires four twisted pairs.  100Base-TX is simpler because the wires can handle clock rates of 125 MHz. Only two twisted pairs per station are used, one to the hub and one from it. Straight binary coding is not used; instead a scheme called used4B/5Bis It is taken from FDDI and compatible with it. The 100Base-TX system is full duplex; stations can transmit at 100 Mbps and receive at 100 Mbps at the same time.  100Base-TX and 100Base-T4 are collectively referred to as 100Base-T.  100Base-FX, uses two strands of multimode fiber, one for each direction, so it, too, is full duplex with 100 Mbps in each direction. The distance between a station and the hub can be up to 2 km. Gigabit Ethernet : Goals of Gigabit Ethernet goals:  Make Ethernet go 10 times faster yet remain backward compatible with all existing Ethernet standards.  Gigabit Ethernet supports two different modes of operation: full-duplex mode and half-duplex mode.  Gigabit Ethernet had to offer unacknowledged datagram service with both unicast and multicast, use the same 48-bit addressing scheme already in use, and maintain the same frame format, including the minimum and maximum frame sizes. Gigabit Ethernet uses new encoding rules on the fibers. Manchester encoding at 1 Gbps would require a 2 Gbaud signal, which was too difficult and also too wasteful of bandwidth. Instead a new scheme, called 8B/10B, was chosen, based on fiber channel. Each 8-bit byte is encoded on the fiber as 10 bits; hence the name 8B/10B.Gigabit Ethernets using 1000Base-T use a different encoding scheme since clocking data onto copper wire in 1 nsec is too difficult.

Q.2 Differentiate the working between pure ALOHA and slotted ALOHA.
ANSWER:

ALOHA: ALOHA is an efficient method to solve the channel allocation problem. There are two versions of ALOHA: pure and slotted. They differ with respect to whether time is divided into slots into which all frames must fit. Pure ALOHA does not require global time synchronization as slotted ALOHA does. Pure ALOHA The basic idea of an ALOHA system is simple: let users transmit whenever they have data to be sent. There will be collisions, of course, and the colliding frames will be damaged. Due to the feedback property of broadcasting, a sender can always find out whether its frame was destroyed by listening to the channel, the same way other users do. If the frame was destroyed, the sender just waits a random amount of time and sends it again. Systems in which multiple users share a common channel in a way that can lead to conflicts are widely known as contention systems.

Fig. Pure ALOHA Fig. depicts frame generation in an ALOHA system. Frames are of same length because the throughput of ALOHA systems is maximized by having a uniform frame size rather than by allowing variable length frames. Packet sent at t0 collides with other Packets sent in [t0-1, t0+1]. Whenever two frames try to occupy the channel at the same time, there will be a collision and both will be garbled. If the first bit of a new frame overlaps with just the last bit of a frame almost finished, both frames will be totally destroyed and both will have to be retransmitted later. The checksum cannot (and should not) distinguish between a total loss and a near miss. Slotted ALOHA To double the capacity of an ALOHA system, time is divided into discrete intervals, each interval corresponding to one frame which is known as slotted ALOHA. This approach requires the users to agree on slot boundaries. One way to achieve synchronization would be to have one special station emit a pip at the start of each interval, like a clock.

Fig. Slotted Aloha

Q.3 Write down distance vector algorithm. Explain path vector protocol.
ANSWER:

Distance Vector Routing algorithm: 1) For each node, estimate the cost from itself to each destination. 2) For each node, send the cost information the neighbors. 3) Receive cost information from the neighbor, update the routing tables accordingly. 4) Repeat steps 1 to 3 periodically. A path vector protocol is a computer network routing protocol which maintains the path information that gets updated dynamically. Updates which have looped through the network and returned to the same node are easily detected and discarded. This algorithm is sometimes used in Bellman–Ford routing algorithms to avoid "Count to Infinity" problems. It is different from the distance vector routing and link state routing. Each entry in the routing table contains the destination network, the next router and the path to reach the destination. Path Vector Messages in BGP: The autonomous system boundary routers (ASBR), which participate in path vector routing, advertise the reachability of networks. Each router that receives a path vector message must verify that the advertised path is according to its policy. If the messages comply with the policy, the ASBR modifies its routing table and the message before sending it to the next neighbor. In the modified message it sends its own AS number and replaces the next router entry with its own identification. BGP is an example of a path vector protocol. In BGP the routing table maintains the autonomous systems that are traversed in order to reach the destination system. Exterior Gateway Protocol (EGP) does not use path vectors.

Q.4 State the working principle of TCP segment header and UDP header.
ANSWER:

TCP Segment Header:
Figure below shows the layout of a TCP segment. Every TCP segment begins with a fixed-format, 20-byte header. The fixed header may be followed by header options. After the options, data bytes may follow. Segments without any data are legal and are commonly used for acknowledgements and control messages.

Fig. The TCP header  The Source port and Destination port fields identify the local end points of the connection. The source and destination end points together identify the connection.  The Sequence number and Acknowledgement number fields perform their usual functions. The latter specifies the next byte expected, not the last byte correctly received.  The TCP header length tells how many 32-bit words are contained in the TCP header. This information is needed because the Options field is of variable length.  Next comes a 6-bit field that is not used. Which is left for future use  Now comes six 1-bit flags. URG bit is set to 1 if the Urgent pointer is in use. The ACK bit is set to 1 to indicate that the Acknowledgement number is valid. If ACK is 0, the segment does not contain an acknowledgement so the Acknowledgement number field is ignored. The PSH bit indicates PUSHed data. The receiver is hereby kindly requested to deliver the data to the application upon arrival and not buffer it until a full buffer has been received. The RST bit is used to reset a connection that has become confused due to a host crash or some other reason. The SYN bit is used to establish connections. The connection request has SYN = 1 and ACK = 0 to indicate that the piggyback acknowledgement field is not in use. The connection reply does bear an acknowledgement, so it has SYN = 1 and ACK = 1. The FIN bit is used to release a connection. It specifies that the sender has no more data to transmit.  The Window size field tells how many bytes may be sent starting at the byte acknowledged.  A Checksum is also provided for extra reliability. It checksums the header and the data.  The Urgent pointer is used to indicate a byte offset from the current sequence number at which urgent data are to be found.  The Options field provides a way to add extra facilities not covered by the regular header. UDP Header: UDP transmits segments consisting of an 8-byte header followed by the payload.

Fig. The UDP header  The source port is primarily needed when a reply must be sent back to the source. By copying the source port field from the incoming segment into the destination port field of the outgoing segment, the process sending the reply can specify which process on the sending machine is to get it.  The UDP length field includes the 8-byte header and the data.  The UDP checksum is optional and stored as 0 if not.

Q.5. What is IP addressing? Discuss different classes of IP Addressing.
ANSWER:

Internet protocols The Internet Protocol (IP) is the method or protocol by which data is sent from one computer to another on the Internet. Each computer is known as a host on the Internet and has at least one IP address that uniquely identifies it from all other computers on the Internet. When you send or receive data (for example, an e-mail note or a Web page), the message gets divided into little chunks called packets. Each of these packets contains both the sender‟s Internet address and the receiver‟s address. Any packet is sent first to a gateway computer that understands a small part of the Internet. The gateway computer reads the destination address and forwards the packet to an adjacent gateway that in turn reads the destination address and so forth across the Internet until one gateway recognizes the packet as belonging to a computer within its immediate neighborhood or domain. That gateway then forwards the packet directly to the computer whose address is specified. Because a message is divided into a number of packets, each packet can, if necessary, be sent by a different route across the Internet. Packets can arrive in a different order than the order they were sent in. The Internet Protocol just delivers them. It‟s up to another protocol, the Transmission Control Protocol (TCP) to put them back in the right order. IP is a connectionless protocol, which means that there is no continuing connection between the end points that are communicating. Each packet that travels through the Internet is treated as an independent unit of data without any relation to any other unit of data. (The reason the packets do get put in the right order is because of TCP, the connection-oriented protocol that keeps track of the packet sequence in a message.) In the Open Systems Interconnection (OSI) communication model, IP is in layer 3, the Networking Layer. IP Addresses As with any other network-layer protocol, the IP addressing scheme is integral to the process of routing IP datagram‟s through an internetwork. Each IP address has specific components and follows basic format. Each host on IP network is assigned a unique 32-bit logical address that is divided into two main parts: the network number and the host number. The network number identifies a network and must be assigned by the Internet Network Information Center (InterNIC) if the network is to be part of the Internet. An Internet Service Provider (ISP) can obtain blocks of network addresses from the InterNIC and can itself assign address space as necessary. The host number identifies a host on a network and is assigned by the local network administrator.

The 32-bit IP address is grouped eight bits at a time, separated by dots, and represented in decimal format (known as dotted decimal notation). Each bit in the octet has a binary weight (128, 64, 32, 16, 8, 4, 2, and 1). The minimum value for an octet is 0, and the maximum value for an octet is 255.An IP address consists of 32 bits, grouped into four octets. IP Address Classes IP addressing supports five different address classes: A, B, C, D, and E. Only, classes A, B, and C are available for commercial use. The left-most (high-order) bits indicate the network class. Table below provides reference information about the five IP address classes.

The class A, B, C, and D formats allow for up to:  128 networks with 16 million hosts each  16,384 networks with up to 64k hosts  million networks with up to 256 hosts each  Also supported is multicast, in which a datagram is directed to multiple hosts.  Addresses beginning with 1111 are reserved for future use.

Q.6 Define Cryptography. Discuss two cryptographic techniques.
ANSWER:

Cryptography Cryptography comes from the Greek words for „‟secret writing‟‟. Cryptographic techniques allow a sender to disguise data so that an intruder can gain no information from the intercepted data. The receiver will be able to recover the original data from the disguised data.

Fig. Cryptographic components Suppose Alice wants to send a message to Bob. Alice‟s message in its original form is known as plaintext, or clear text. Alice encrypts her plaintext message using an encryption algorithm so that the encrypted message, known as cipher text, looks unintelligible to any intruder. As illustrated in Fig .Alice provides a key, KA, as input to the encryption algorithm. The encryption algorithm takes the key and the plaintext as input and produces cipher text as output. Similarly Bob provide a key KB, to the decryption algorithm, that takes the cipher text and Bob‟s key as input and produces the original plaintext as output. There are two Cryptographic techniques: · Symmetric key Technique: In this technique identical keys will be shared by both sender and receiver of data. Same keys will be used to encrypt and decrypt the data. · Paired key Technique: In this technique pair of keys (Public/Private pair) will be shared among the sender and receiver of data. Sender uses receivers public key to encrypt the data and the receiver uses his own private key to decrypt the data. Data Encryption Standard (DES): The Data Encryption Standard (DES) is a symmetric key encryption standard.  The DES consists of two permutation steps (the first and last steps of the algorithm) in which all 64 bits are permuted, and 16 identical "rounds" of operation in between.  The operation of each round is identical, taking the output of the previous round as input. During each round, the rightmost 32 bits of the input are moved to the left 32 bits of the output.  The entire 64-bit input to the ith round and the 48 bit key for the ith round (derived from the larger DES 56-bit ) are taken as input to a function that involves expansion of four-bit input chunks into six-bit chunks, exclusive ORing with the expanded six bit chunks of the 48-bit key Ki, a substitution operation and further exclusive OR-ing with the leftmost 32 bits of the input.  The resulting 32-bit output of the function is then used as the rightmost 32 bits of the rounds 64-bit output, as shown in Figure  Decryption works by reversing the algorithm‟s operations.

Digital Signatures: Just as with human signatures, digital signing should be done in such a way that digital signatures are verifiable, nonforgible, and non-repudiable. That is, it must be possible to "prove" that a document signed by an individual was indeed signed by that individual and that only that individual could have signed the document (the signature can not be forged, and a signer cannot later repudiate or deny having signed the document). This is easily accomplished with public key cryptography.

MI0036 – BUSINESS INTELLIGENCE TOOLS
Q.1 Explain business development life cycle in detail?
ANSWER:

ASSIGNMENT - SET- 2

Business Intelligence Lifecycle Business Intelligence (BI) lifecycle refers to the computer-based techniques used in gathering, evaluating business information, such as sales revenue by products and/divisions associated prices and profits. The BI lifecycle frequently aims to enhance superior business decision-making techniques. The BI lifecycle representation mainly highlights on the iterative approach which is necessary to effectively pull out the greatest profit from investment in Business Intelligence. This approach is iterative as the BI solution needs to progress as and when the business develops. A quick example is a customer who developed a good product for standard selling cost per unit. This made sense and facilitated them to discover price demands in their market and take suitable action. On the other hand when they obtained a company whose standard selling cost was 100 times greater than the metric became deformed and required a second thought. The BI lifecycle model begins with Design phase which has suitable key performance indicators; It executes the structure with proper methodologies and equipments. The Utilise phase involves its own performance cycle. Plan phase concludes what value the key performance indicators should be, and Monitors what they are. Analyses phase is to recognize the variations. Monitoring will use the control panels and scorecards to explain the information quickly and evidently. Analyses will take the benefit of new BI tools such as Excel Microsoft ProClarity, QlikView or other professional software to investigate the information and genuinely know trends in the essential data. A significant step is then to take stock of the procedure. It is to find out how it is performing or it requires any alterations. The Refine phase is critical as it takes BI to the next significant phase, and is often misplaced from a BI program in the excitement of a successful execution. The Business Intelligence Lifecycle acts similar to the Data Maturity Lifecycle to offer a complete maturation model on information intelligence. Also this model gives a roadmap to utilise certain rules which helps in the development of a business intelligence program. BI Program is a long term scheme but not a short term. As the business goes on changing, and knowledge that supports analytics also improves, this lifecycle can repeat and forms a complete new performance management. Note: Key performance indicators (KPI) are very significant factors in business intelligence operation. It is the aspect, which gives information about present status of business and future action plan to develop the business.

Q.2 Discuss the various components of data warehouse?
ANSWER

Data Extraction is the act or the process of extracting data out of, which is usually unstructured or badly structured, data sources for added data processing or data storage or data migration. This data can be extracted from the web. The internet pages in the html, xml etc can be considered to be unstructured data source because of the wide variety in the code styles. This also includes exceptions and violations of the standard coding practices. The import into the intermediate extracting system can be usually followed by data transformation and possibly the inclusion of metadata prior to export to another stage in the data workflow. Usually unstructured data sources include web pages, emails, documents, PDFs, scanned text, mainframe reports, spool files etc. Extracting the data from these unstructured sources has become a considerable technical challenge where as historically data extraction had to deal with changes in physical hardware formats. Majority of the current data extraction deals with extracting the data from the unstructured data sources, and from different software formats. The rising process of data extraction from the web is also known as Web scraping. The process of adding structure to unstructured data can be done in a number of forms:  Using a text pattern matching which is also known as Regular expression to recognise small or large scale structure. For example, records in a report and their related data from headers and footers.

 

Using the table-based approach to recognise the common sections within a limited domain. For example, in resumes identify the skills, previous work experience, qualifications etc. Using a standard set of commonly used headings. For example, Education might be found under Education or Qualification or Courses. Using the text analytics to try to understand the text and then link it to other information.

Overview of Extraction, Transformation, and Loading (ETL) The data warehouse should be loaded regularly so that the purpose of facilitating business analysis can be served. In order to perform this operation, data from one or more operational systems must be obtained and copied into the warehouse. The process of obtaining data from the source systems and bringing it into the data warehouse is usually called Extraction, Transformation, and Loading (ETL). ETL is perhaps too simple, because it omits the transportation phase and indicates that each of the other phases of the process is different. The whole process along with data loading is referred to as ETL. ETL relates to a broad process and not to the three well-defined steps. The methodology and the tasks of ETL have been well known for many years, and are not essentially unique to data warehouse environments where a wide variety of proprietary applications and database systems are considered as the IT backbone of any enterprise. Data has to be shared between the applications or systems, try to combine them, and give at least two applications the same picture of the world. This kind of data sharing was regularly addressed by mechanisms similar to what is now known as ETL. In Data warehouse environments apart from exchange there is additional burden of integrating, rearranging and consolidating data over many systems, thus, providing a new combined information base for business intelligence. Furthermore, the data volume in data warehouse environment tends to be very big. In the ETL process, during extraction the desired data will be identified and extracted from many different sources including database systems and applications. Often it is not possible to recognise the particular subset of interest, therefore more data than required has to be extracted, so the recognition of the appropriate data can be done at a later point in time. Depending on the source system‟s capabilities, for example in the operating system resources, some transformations can take place during the extraction process. The size of the extracted data can range from hundreds of kilobytes up to gigabytes, depending on the source system and the business situation. The same is true for the time delta between two logically identical extractions where the time span can differ between days/hours and minutes to near real-time. The Web server‟s log files for example can easily become hundreds of megabytes in a very short span of time. After extracting the data, it has to be physically moved to the target system or to an intermediate system for further processing. Depending on the selected way of transportation, some transformations can be done during this process. For example, a SQL statement which can directly access a remote target through a gateway can concatenate two columns using the SELECT statement. Offline Extract, Transform, and Load (ETL) Previously the one common interface that was given between the dissimilar systems in an organisation was magnetic tape. They were standardized and any system could have written tapes that could be read by other systems. So, the first data warehouses were fed by magnetic tapes prepared by different systems within the organisation which left the problem of data disparity. There is often little relation to data written to tape to one system to data written by another system. The data warehouse‟s database was designed to support the analytical functions necessary for the business intelligence function. The database design was a well structured database with complex indices to support the Online Analytical Processing (OLAP). The databases configured for OLAP allows the complex analytical and ad hoc queries with quick execution time. The data given to the data warehouse from the enterprise system gets transformed to a format understandable to the data warehouse. To overcome the problem of loading the data initially to the data warehouse, keeping it updated and resolving discrepancies the Extract, Transform and Load (ETL) utilities were developed. The key to the success of this approach is the transformation function. The transform function is the key to the success of this approach and helps to apply a series of rules to the extracted data so that it is correctly formatted for loading into t he data warehouse. The examples of transformation rules are:  Selecting the data to load.  Translating the encoded items.  Encoding and standardizing the free-form values.  Deriving the new calculated values that is sale price = price – discount.

     

Merging of data from multiple sources. Summarizing or aggregating certain rows and columns. Splitting a column into multiple columns for example- a comma-separated list. Resolving the discrepancies between similar data items. Validating the data. Ensuring the data consistency.

The ETL function allows the integration of multiple data sources into a well-structured database for the use in complex analyses. The ETL process will have to be executed periodically such as daily, weekly, or monthly, depending on the business needs. This process is called the offline ETL because the target database is not always updated. It is updated periodically on batch basis. Though the offline ETL serves its purpose well there are some serious drawbacks which are as follows:  The data in the data warehouse could be weeks old. Therefore, it is helpful for planned functions but is not particularly adaptable for tactical uses.  The source database typically should be inactive during the extract process. Or else, the target database is not in a consistent state following the load. Considering this result, the applications must be shut down, often for hours. In online ETL, the function of ETL is to support the real-time business intelligence which should be continuous and noninvasive. In contrast to offline ETL which gives old but consistent responses to queries the online ETL gives present but varying responses to successive queries. This is because the data that it uses is continuously updated to reflect the present state of the enterprise. The Offline ETL technology has always served businesses for decades. The intelligence that is obtained from this data informs long-term reactive strategic decision making. On the other hand, the short-term operational and proactive tactical decision making will continue to rely on instinct.

Q.3.Discuss data extraction process? What are the various methods being used for data extraction?
ANSWER

Various data extraction techniques The extraction method has to be selected based on the source system and also on the business needs in the target data warehouse environment. Often there‟s no option to add additional logic to the source systems to improve an incremental extraction of data due to the performance or the increased workload of these systems. Sometimes even the customer cannot add anything to an out-of-the-box application system. The expected amount of the data to be extracted and the stage in the ETL process which can be initial load or maintenance of data may also affect the decision of how to extract. Basically, the decision has to be made on how to extract data logically and physically.

1. The Logical Extraction Methods
There are two kinds of logical extraction methods:  Full Extraction  Incremental Extraction Full Extraction: In full extraction the data is extracted totally from the source system. Since, this extraction reflects all the data which is presently available on the source system there will be no need to keep track of the changes to the data source since the previous successful extraction. The source data will be given as it is and no additional logical information for example timestamps is required on the source site. An example for full extraction may be an export file of a distinct table or a remote SQL statement scanning the complete source table. Incremental Extraction: At a particular point in time, only the data that has been altered since a well-defined event back in the history will be extracted. This event might be the last time of extraction or a more difficult business event like the last booking day of a

fiscal period. To recognise this delta change there must be an option to recognise all the changed information since this particular time event. This information can be either given by the source data like an application column. This might reflect the last changed timestamp or a changed table where an appropriate additional mechanism will keep track of the changes apart from the originating transactions. In most of the cases, using the latter method means adding the extraction logic to the source system. There are many data warehouses which do not use any change-capture techniques as part of the extraction process. Instead the entire table from the source systems is extracted to the data warehouse or to the staging area, and these tables are then compared with a previous extract from the source system to recognize the changed data. This approach may not have important affect on the source systems, but can clearly place an important burden on the data warehouse processes.

2. Physical Extraction Methods
Depending on the selected logical extraction method and the potentials and limitations on the source side, the retrieved data can be physically extracted using two methods. The data can be either extracted online from the source system or from an offline structure. Such an offline structure may already exist or it may be created by an extraction routine. The following are the methods of physical extraction:  Online Extraction  Offline Extraction Online Extraction In online extraction the data is extracted directly from the source system itself. The extraction process can then connect directly to the source system to access the source tables themselves or to an intermediate system that keeps the data in a preconfigured manner. For example, snapshot logs or change tables . Note that the middle system is not essentially physically different from the source system. With online extractions, we need to consider if the distributed transactions are using the original source objects or the prepared source objects. Offline Extraction The data is not extracted directly from the source system but is kept explicitly outside the original source system. The data already has an existing structure for example, redo logs, archive logs or transportable tablespaces. The following structures can be considered:  Flat files: In flat files the data is in a defined, generic format. The Additional information about the source object is required for further processing.  Dump files: In Dump files the information about the containing objects is included.  Redo and archive logs: In redo and archive logs the information is in a special, additional dump file.  Transportable table spaces: Transportable tablespaces are a powerful way to extract and move large volumes of data between Oracle databases. Oracle Corporation suggests that the transportable tablespaces can be used whenever possible, because they can provide significant advantages in performance and manageability over the other extraction techniques.

3. Change Data Capture
An important consideration in extraction is the incremental extraction, also known Change Data Capture. If a data warehouse extracts data from an operational system on an every night basis, then the data warehouse may require only the data that has changed since the last extraction which might be the data that has been modified in the past 24 hours. When it is possible to ably identify and extract only the most recently changed data, the extraction process as well as all the downstream operations in the ETL process can be much more efficient, because it must extract a much smaller volume of data. Unfortunately, for many source systems, recognising the recently modified data can be difficult or intrusive to the operation of the system. Change Data Capture is typically the most demanding technical issue in data extraction. This is because the change data capture is often desirable as part of the extraction process and it may not be possible to use Oracle‟s Change Data Capture mechanism. There are several techniques for implementing a self-developed change capture on Oracle source systems:  Timestamps  Partitioning  Triggers

These techniques are based on the characteristics of the source systems, or may need modifications to the source systems. Thus, each of these techniques must be carefully evaluated by the owners of the source system before the implementation. Each of these techniques can work in combination with the data extraction techniques. For example, the timestamps can be used whether the data is being unloaded to a file or accessed through a distributed query. Timestamps There are some tables in operational systems which have timestamp columns. This timestamp tells the time and date that a given row was last modified. If the table in an operational system has columns having timestamps, then the latest data can be easily identified using the timestamp columns. For example, the following query might help in extracting today‟s data from an orders table: SELECT * FROM orders WHERE TRUNC(CAST(order_date AS date),‟dd‟) = TO_DATE(SYSDATE,‟dd-mon-yyyy‟) If the timestamp information is not there in an operational source system, then it may not be possible to modify the system to include timestamps. Such modifications would first require modifying the operational system‟s tables to include a new timestamp column and then creating a trigger which would help to update the timestamp column after every operation that modifies a given row. Partitioning Some source systems may use Oracle range partitioning, so that the source tables are partitioned along a date key, which would allow easy identification of new data. For example, if you are extracting from an orders table, and the orders table is partitioned by week, then it is easy to identify the present week‟s data. Triggers Triggers can be created in operational systems to keep track of the recently updated records. They can then be used along with timestamp columns to recognise the exact time and date when a given row was last modified. This can be done by creating a trigger on each source table that requires change data capture. Following each DML statement that is executed on the source table, this trigger helps to update the timestamp column with the current time. Thus, the timestamp column gives the exact time and date when a given row was last modified. A similar internalised trigger-based technique is used for Oracle materialised view logs. These are the logs which are used by materialised views to identify changed data, and these are the logs which are accessible to end users. A materialised view log can be created on each source table which would require change data capture. Whenever there are any modifications to be made to the source table, a record is inserted into the materialised view log showing which rows were modified. Materialised view logs rely on triggers, but also provide an advantage in the creation and maintenance of the change-data system which is largely managed by Oracle. However, Oracle suggests the use of synchronous Change Data Capture for trigger based change capture. Since, Change Data Capture provides an externalized interface for accessing the change information and also provide a framework for maintaining the distribution of the information to various clients. The Trigger-based techniques affect the performance on the source systems, and should be carefully considered before applying on a production source system. Extracting data from the operational systems The data in the operational system has to be located within the company once the data for analysis purpose has been identified. The data which is required for the warehouse is extracted from the source operational systems and written into the staging area which will be later transformed. To minimize the performance impact on the source database the data should be loaded without applying the transformations to it. More often the operational system‟s owners will not let the warehouse developers to directly access the systems but can give periodic extracts. These extracts will usually be in the form of flat, sequential operating system files, which will make the staging area. The application programs have to be developed to select the fields and records necessary for the warehouse. If the data is kept in a legacy system, then it can b e written in COBOL which will require special logic to handle things such as the repeating fields in the "COBOL occurs clause." The data warehouse designers have to work with the application developers for the OLTP systems which are usually built to extract scripts which provide the required columns and formats of the data. As part of designing the ETL process, how frequently data should be extracted from the operational systems should be determined. It can be at the end of some time period or business event, such as at the end of the day or week or the closing of the fiscal quarter. The meaning of "end of the day" or the "last day of the week," has to be clearly defined if the system is used across different time zones. This kind of extraction can be done at different times for different systems and considered to be loaded into the warehouse during an upcoming batch window. Another feature of the warehouse design process involves deciding what level of aggregation has to be used to answer the business queries. This also has an effect on what and how much data is extracted and transported across the network.

Some of the operational systems may be in relational databases, such as Oracle 8i or 9i, Oracle Rdb, DB2/MVS, Microsoft SQL Server, Sybase, or Informix. Others can be in a legacy database format, such as the IMS or Oracle DBMS. Others may be in the VSAM, RMS indexed files, or some other structured file system. If it is possible to access the source systems directly, then the data can be obtained out by a variety of techniques depending on the type of system the data is in. For small amounts of data, you can use a gateway or Open Database Connectivity (ODBC). When there are large amounts of data, a custom program will be directly connected to the source database in the database‟s native. Many ETL tools will simplify the extraction process by giving connectivity to the source. The Data to be used in the data warehouse must be extracted from the operational systems that will have the source data. Data should first be extracted during the data warehouse creation, and the ongoing periodic extractions will occur during the updates of the data warehouse. Data extraction can be a simple operation, if the source data is kept in a single relational database, or a very complex operation, if the source data is kept in multiple heterogeneous operational systems. The aim of the data extraction process is to bring all the source data into a common, consistent format so it will be available for loading into the data warehouse. It is better if the data in the source operational systems do not contain validation errors. For example, the purchase records for which there are no relevant customer records to recognise the purchasers are clearly the errors in the source data, and should be corrected in the source operational system before the data is extracted for loading into the data warehouse. It might be possible to implement error checking in the source operational system so that the errors can be detected before extracting the data for the data warehouse. If such errors occur frequently, then the operational system will have to be examined and modified to reduce such errors because such errors might affect the organisation‟s business as well as the data warehouse. It may not be possible to identify the validation errors until the data has been extracted from the operational systems. This situation can take place when the data is extracted from multiple data sources. For example, integrating data extracted from separate sales tracking, shipping, and billing systems might uncover discrepancies that should be addressed in one or more of the source systems. You may also recognize the inconsistencies other than the errors in the data after it has been extracted. For example, different type of data sources may used for different coding systems for the similar kind of data. You can also use translation tables to reconcile the differences during the extraction operation or later during the transformation operations. For example, a legacy system might code state province names using a three-character code, whereas another system might use a two-character code. The data obtained from one or both of these systems should be translated into a single set of codes before the data is loaded into the data warehouse. In other cases, inconsistencies can be discovered if the source systems allow free-form entry of text information. Such data is often internally not consistent because different data-entry personnel can enter the same data in different ways. The inconsistent representations of the same data will have to be reconciled if such data is used for analysis. For example, in a data source that allows free-form text entry for the state or province portion of an address then the state of Florida can be entered as FL, Fla, Florida, or even Flor. It may become difficult to modify legacy source systems to implement a standard coding validation. The Manual transformation adjustments might be necessary to reconcile such differences if the contributing source systems cannot be modified. Data in Operational Systems The source systems usually store data in two ways. The operational data in the source system can be classified into two broad categories. The type of data extraction technique may depend on the nature of each of the following two categories:  Current Value  Periodic Status Current Value: In current value most of the attributes in the source systems fall into this category. Here, the stored value of an attribute shows the value of the attribute at this moment of time. The values of which are transient or transitory. As the business transactions occur, the values will also change. Prediction of how long the present value will stay or when it will get changed cannot be made. Therefore, the current value is the stored value of an attribute which occurs at that moment of time. Periodic Status: In periodic status the value of the attributes are stored as the status every time a change happens. This means the status value is stored with the reference to the time. For example, the data about an insurance policy is kept as the status data of

the policy at every point of time. So the history of the changes is kept in the source systems themselves. This makes the data extraction becomes relatively simple.

Q.4 Discuss the needs of developing OLAP tools in details?
ANSWER

Online Analytical Processing OLAP is a data warehousing tool used to organise, partition and summarise data in the data warehouse and data marts. OLAP is an approach to respond quickly to multi-dimensional analytical queries. OLAP belongs to the category of business intelligence. OLAP finds applications in business reporting for sales, marketing, budgeting and forecasting, management reporting, business process management, financial reporting and similar areas. The output of an OLAP query is displayed as a matrix. The dimensions form the rows and columns of the matrix and the measures form the values. OLAP creates a hypercube of information. The cube metadata is usually created from a star schema or snowflake schema (to be discussed later) of tables in a relational database. Characteristics of OLAP The data warehouse dealers and few other researchers have extracted a general definition for OLAP which is FASMI. It stands for Fast, Analysis, Shared, Multidimensional, and Information. Let us discuss these characteristics in detail.  Fast: This refers to the ability of OLAP to respond to the user requests in less than 5 seconds. The response time for a complex requests would probably take 20 seconds. The speed is achieved by using various techniques like specialised data storage, certain hardware components, pre-calculations and so on.  Analysis: OLAP has the capacity of handling any business or statistical analysis for users. The most commonly used analysis techniques are slice and dice and drill down.  Shared: When multiple write access is granted, the system has the ability to maintain confidentiality and lock simultaneous update. The recent OLAP products realise the need for write access and are capable of handling updates from multiple users in a timely order. Shared also refers to the ability of the system to provide multiple user access without letting the files to duplicate.  Multidimensionality: It is the main feature of OLAP products. Multidimensionality requires organising data in the format as per the organisation‟s actual business dimension. For example, in a marketing company, the dimensions maybe lined on dimensions like clients, products, sales, time and so on. The cells contain relevant data at the intersection of dimensions. Sometimes cells are left blank. For example, a client may not always buy products at all time frames. This is called sparsity.  Information: Refers to all the data and required information for users. The data capacity varies with factors like data access methods and level of data duplication. OLAP must contain the data which the user requires and must provide efficient data analysis techniques. Different techniques can be followed to attain FASMI objectives which include client-server architecture, time series analysis, object orientation, parallel processing, optimised data storage, and multi-threading. OLAP Tools Online Analytical Processing falls under the group of software tools which enables the analysis of data stored in a database. It is often used in data mining. Using this tool, user can analyse various dimensions of a multidimensional data. For example, it provides both the time analysis and the trend analysis views. There are two types of OLAP tools. They are: Multidimensional OLAP (MOLAP): In this type of OLAP a cube is extracted from the relational data warehouse. Once the user generates a report request, the MOLAP tools responds quickly as the data is extracted. Relational OLAP (ROLAP): In this type of OLAP, the data is not extracted. The ROLAP engine behaves like a smart SQL generator. The ROLAP tool comes with a „Designer‟ piece, where the data warehouse administrator can not only specify the relationship between the relational tables, but also how dimensions, attributes, and hierarchies map to the database tables. As of now the ROLAP and MOLAP traders are going in for the combination of both. MOLAP traders find it necessary to get down to low levels of details at times and ROLAP traders find it important to deliver results to users at a rapid pace. Hence the traders find it essential to merge both the tools.

Q.5 What do you understand by the term statistical analysis? Discuss the most important statistical techniques?
ANSWER

STATISTICAL ANALYSIS Statistical analysis refers to a collection of methods used to process large amounts of data and report overall trends. Statistical analysis is particularly useful when dealing with noisy data. Statistical analysis provides ways to objectively report on how unusual an event is based on historical data. Our server uses statistical analysis to examine the tremendous amount of data produced every day by the stock market. We usually prefer statistical analysis to more traditional forms of technical analysis because statistical analysis makes use of every print. Candlesticks, by comparison, throw away an arbitrary number of prints before the analysis starts. Candlesticks, point and figure charts, and other traditional forms of technical analysis were designed long ago. They were specifically created for people who were analyzing the data by hand. Statistical analysis looks at more data, and typically requires a computer.

Q.6 What are the methods for determining the executive needs?
ANSWER

Five basic methods for determining information needs:  By-Product Method  Null Method  Key Indicator Method  Total Study Method Critical Success Factors Method

MI0050 – RESEARCH METHODOLOGY
Q1. What is the significance of research in social and business sciences?
ANSWER:

ASSIGNMENT - SET- 2

According to a famous Hudson Maxim, “All progress is born of inquiry. Doubt is often better than overconfidence, for it leads to inquiry, and inquiry leads to invention”. It brings out the significance of research, increased amounts of which makes progress possible. Research encourages scientific and inductive thinking, besides promoting the development of logical habits of thinking and organization. The role of research in applied economics in the context of an economy or business is greatly increasing in modern times. The increasingly complex nature of government and business has raised the use of research in solving operational problems. Research assumes significant role in formulation of economic policy, for both the government and business. It provides the basis for almost all government policies of an economic system. Government budget formulation, for example, depends particularly on the analysis of needs and desires of the people, and the availability of revenues, which requires research. Research helps to formulate alternative policies, in addition to examining the consequences of these alternatives. Thus, research also facilitates the decision making of policy-makers, although in itself it is not a part of research. In the process, research also helps in the proper allocation of a country‟s scare resources. Research is also necessary for collecting information on the social and economic structure of an economy to understand the process of change occurring in the country. Collection of statistical information though not a routine task, involves various research problems. Therefore, large staff of research technicians or experts is engaged by the government these days to undertake this work. Thus, research as a tool of government economic policy formulation involves three distinct stages of operation which are as follows:    Investigation of economic structure through continual compilation of facts Diagnoses of events that are taking place and the analysis of the forces underlying them; and The prognosis, i.e., the prediction of future developments

Research also assumes a significant role in solving various operational and planning problems associated with business and industry. In several ways, operations research, market research, and motivational research are vital and their results assist in taking business decisions. Market research is refers to the investigation of the structure and development of a market for the formulation of efficient policies relating to purchases, production and sales. Operational research relates to the application of logical, mathematical, and analytical techniques to find solution to business problems such as cost minimization or profit maximization, or the optimization problems. Motivational research helps to determine why people behave in the manner they do with respect to market characteristics. More specifically, it is concerned with the analyzing the motivations underlying consumer behaviour. All these researches are very useful for business and industry, which are responsible for business decision making. Research is equally important to social scientist for analyzing social relationships and seeking explanations to various social problems. It gives intellectual satisfaction of knowing things for the sake of knowledge. It also possesses practical utility for the social scientist to gain knowledge so as to be able to do something better or in a more efficient manner. This, research in social sciences is concerned with both knowledge for its own sake, and knowledge for what it can contribute to solve practical problems.

Q2. What is the meaning of hypothesis? Discuss the types of hypothesis.
ANSWER

A hypothesis is an assumption about relations between variables. It is a tentative explanation of the research problem or a guess about the research outcome. A hypothesis carries clear implications for testing the stated relationship, i.e., it contains variables that are measurable and specifying how they are related. A statement that lacks variables or that does not explain how the variables are related to each other is no hypothesis in scientific sense.

Types of Hypothesis There are many kinds of hypothesis the researcher has to be working with. One type of hypothesis asserts that something is the case in a given instance; that a particular object, person or situation has particular characteristics. Another type of hypothesis deals with the frequency of occurrence or of association among variables; this type of hypothesis may state that X is associated with Y. A certain Y proportion of items e.g. urbanism tends to be accompanied by mental disease or than something are greater or lesser than some other thing in specific settings. Yet another type of hypothesis asserts that a particular characteristics is one of the factors which determine another characteristic, i.e. X is the producer of Y. hypothesis of this type are called causal hypothesis. Null Hypothesis and Alternative Hypothesis In the context of statistical analysis, we often talk null and alternative hypothesis. If we are to compare method A with method B about its superiority and if we proceed on the assumption that both methods are equally good, then this assumption is termed as null hypothesis. As against this, we may think that the method A is superior, it is alternative hypothesis. Symbolically presented as: Null hypothesis = H0 and Alternative hypothesis = Ha Suppose we want to test the hypothesis that the population mean is equal to the hypothesis mean (µ H0) = 100. Then we would say that the null hypotheses are that the population mean is equal to the hypothesized mean 100 and symbolical we can express as: H0: µ= µ H0=100

If our sample results do not support these null hypotheses, we should conclude that something else is true. What we conclude rejecting the null hypothesis is known as alternative hypothesis. If we accept H0, then we are rejecting Ha and if we reject H0, then we are accepting Ha. For H0: µ= µ H0=100, we may consider three possible alternative hypotheses as follows:

The null hypothesis and the alternative hypothesis are chosen before the sample is drawn (the researcher must avoid the error of deriving hypothesis from the data he collects and testing the hypothesis from the same data). In the choice of null hypothesis, the following considerations are usually kept in view:  Alternative hypothesis is usually the one which wishes to prove and the null hypothesis are ones that wish to disprove. Thus a null hypothesis represents the hypothesis we are trying to reject, the alternative hypothesis represents all other possibilities.  If the rejection of a certain hypothesis when it is actually true involves great risk, it is taken as null hypothesis because then the probability of rejecting it when it is true is α (the level of significance) which is chosen very small.  Null hypothesis should always be specific hypothesis i.e., it should not state about or approximately a certain value.  Generally, in hypothesis testing we proceed on the basis of null hypothesis, keeping the alternative hypothesis in view. Why so? The answer is that on assumption that null hypothesis is true, one can assign the probabilities to different possible sample results, but this cannot be done if we proceed with alternative hypothesis. Hence the use of null hypothesis (at times also known as statistical hypothesis) is quite frequent.

Q3. Explain the sampling process.
ANSWER

The decision process is a complicated one. The researcher has to first identify the limiting factor or factors and must judiciously balance the conflicting factors. The various criteria governing the choice of the sampling technique are: 1. Purpose of the Survey: What does the researcher aim at? If he intends to generalize the findings based on the sample survey to the population, then an appropriate probability sampling method must be selected. The choice of a particular type of probability sampling depends on the geographical area of the survey and the size and the nature of the population under study.

2. Measurability: The application of statistical inference theory requires computation of the sampling error from the sample itself. Only probability samples allow such computation. Hence, where the research objective requires statistical inference, the sample should be drawn by applying simple random sampling method or stratified random sampling method, depending on whether the population is homogenous or heterogeneous. 3. Degree of Precision: Should the results of the survey be very precise, or could even rough results serve the purpose? The desired level of precision is one of the criteria for sampling method selection. Where a high degree of precision of results is desired, probability sampling should be used. Where even crude results would serve the purpose (E.g., marketing surveys, readership surveys etc), any convenient non-random sampling like quota sampling would be enough. 4. Information about Population: How much information is available about the population to be studied? Where no list of population and no information about its nature are available, it is difficult to apply a probability sampling method. Then an exploratory study with non-probability sampling may be done to gain a better idea of the population. After gaining sufficient knowledge about the population through the exploratory study, an appropriate probability sampling design may be adopted. 5. The Nature of the Population: In terms of the variables to be studied, is the population homogenous or heterogeneous? In the case of a homogenous population, even simple random sampling will give a representative sample. If the population is heterogeneous, stratified random sampling is appropriate. 6. Geographical Area of the Study and the Size of the Population: If the area covered by a survey is very large and the size of the population is quite large, multi-stage cluster sampling would be appropriate. But if the area and the size of the population are small, single stage probability sampling methods could be used. 7. Financial Resources: If the available finance is limited, it may become necessary to choose a less costly sampling plan like multistage cluster sampling, or even quota sampling as a compromise. However, if the objectives of the study and the desired level of precision cannot be attained within the stipulated budget, there is no alternative but to give up the proposed survey. Where the finance is not a constraint, a researcher can choose the most appropriate method of sampling that fits the research objective and the nature of population. 8. Time Limitation: The time limit within which the research project should be completed restricts the choice of a sampling method. Then, as a compromise, it may become necessary to choose less time consuming methods like simple random sampling, instead of stratified sampling/sampling with probability proportional to size; or multi-stage cluster sampling, instead of single-stage sampling of elements. Of course, the precision has to be sacrificed to some extent. 9. Economy: It should be another criterion in choosing the sampling method. It means achieving the desired level of precision at minimum cost. A sample is economical if the precision per unit cost is high, or the cost per unit of variance is low. The above criteria frequently conflict with each other and the researcher must balance and blend them to obtain a good sampling plan. The chosen plan thus represents an adaptation of the sampling theory to the available facilities and resources. That is, it represents a compromise between idealism and feasibility. One should use simple workable methods, instead of unduly elaborate and complicated techniques.

Q4. Distinguish between Schedules and Questionnaires?
ANSWER

There is a difference between a schedule and a questionnaire. A schedule is a form that the investigator fills himself through surveying the units or individuals. A questionnaire is a form sent (usually mailed) by an investigator to respondents. The respondent has to fill it and then send it back to the investigator. Questionnaires Often, information is collected through questionnaires. The questionnaires are filled with questions pertaining to the investigation. They are sent to the respondents with a covering letter soliciting cooperation from the respondents (respondents are the people who respond to questions in the questionnaire). The respondents are asked to give correct information and to mail the questionnaire back. The objectives of investigation are explained in the covering letter together with assurance for keeping information provided by the respondents as confidential. Good questionnaire construction is an important contributing factor to the success of a survey. When questionnaires are properly framed and constructed, they become important tools by which statements can be made about specific people or entire populations. This method is generally adopted by research workers and other official and non-official agencies. This method is used to cover large areas of investigation. It is more economical and free from investigator‟s bias. However, it results in many

“non-response” situations. The respondent may be illiterate. The respondent may also provide wrong information due to wrong interpretation of questions. Schedule Filled By Investigators Information can be collected through schedules filled by investigators through personal contact. In order to get reliable information, the investigator should be well trained, tactful, unbiased and hard working. A schedule is suitable for an extensive area of investigation through investigator‟s personal contact. The problem of nonresponse is minimised. There is a difference between a schedule and a questionnaire. A schedule is a form that the investigator fills himself through surveying the units or individuals. A questionnaire is a form sent (usually mailed) by an investigator to respondents. The respondent has to fill it and then send it back to the investigator.

Q5. What are the problems encountered in the interview?
ANSWER

Interview Problems In personal interviewing, the researcher must deal with two major problems, inadequate response, non-response and interviewer‟s bias. 1. Inadequate response Kahn and Cannel distinguish five principal symptoms of inadequate response. They are:  partial response, in which the respondent gives a relevant but incomplete answer  non-response, when the respondent remains silent or refuses to answer the question  irrelevant response, in which the respondent‟s answer is not relevant to the question asked  inaccurate response, when the reply is biased or distorted and  verbalized response problem, which arises on account of respondent‟s failure to understand a question or lack of information necessary for answering it. 2. Interviewer’s Bias The interviewer is an important cause of response bias. He may resort to cheating by „cooking up‟ data without actually interviewing. The interviewers can influence the responses by inappropriate suggestions, word emphasis, tone of voice and question rephrasing. His own attitudes and expectations about what a particular category of respondents may say or think may bias the data. Another source of response of the interviewer‟s characteristics (education, apparent social status, etc) may also bias his answers. Another source of response bias arises from interviewer‟s perception of the situation, if he regards the assignment as impossible or sees the results of the survey as possible threats to personal interests or beliefs he is likely to introduce bias. As interviewers are human beings, such biasing factors can never be overcome completely, but their effects can be reduced by careful selection and training of interviewers, proper motivation and supervision, standardization or interview procedures (use of standard wording in survey questions, standard instructions on probing procedure and so on) and standardization of interviewer behaviour. There is need for more research on ways to minimize bias in the interview. 3. Non-response Non-response refers to failure to obtain responses from some sample respondents. There are many sources of nonresponse; non-availability, refusal, incapacity and inaccessibility. 4. Non-availability Some respondents may not be available at home at the time of call. This depends upon the nature of the respondent and the time of calls. For example, employed persons may not be available during working hours. Farmers may not be available at home during cultivation season. Selection of appropriate timing for calls could solve this problem. Evenings and weekends

may be favourable interviewing hours for such respondents. If someone is available, then, line respondent‟s hours of availability can be ascertained and the next visit can be planned accordingly. 5. Refusal Some persons may refuse to furnish information because they are ill-disposed, or approached at the wrong hour and so on. Although, a hardcore of refusals remains, another try or perhaps another approach may find some of them cooperative. Incapacity or inability may refer to illness which prevents a response during the entire survey period. This may also arise on account of language barrier. 6. Inaccessibility Some respondents may be inaccessible. Some may not be found due to migration and other reasons. Non-responses reduce the effective sample size and its representativeness. 7. Methods and Aims of control of non-response Kish suggests the following methods to reduce either the percentage of non-response or its effects: 1. Improved procedures for collecting data are the most obvious remedy for non-response. Improvements advocated are a. guarantees of anonymity, b. motivation of the respondent to co-operate c. arousing the respondents‟ interest with clever opening remarks and questions, d. Advance notice to the respondents. 2. Call-backs are most effective way of reducing not-at-homes in personal interviews, as are repeated mailings to noreturns in mail surveys. 3. Substitution for the non-response is often suggested as a remedy. Usually this is a mistake because the substitutes resemble the responses rather than the non-responses. Nevertheless, beneficial substitution methods can sometimes be designed with reference to important characteristics of the population. For example, in a farm management study, the farm size is an important variable and if the sampling is based on farm size, substitution for a respondent with a particular size holding by another with the holding of the same size is possible. Attempts to reduce the percentage or effects on non-responses aim at reducing the bias caused by differences on nonrespondents from respondents. The non-response bias should not be confused with the reduction of sampled size due to non-response. The latter effect can be easily overcome, either by anticipating the size of non-response in designing the sample size or by compensating for it with a supplement. These adjustments increase the size of the response and the sampling precision, but they do not reduce the non-response percentage or bias.

Q6. Write short notes on the following: a. Dispersion b. Mathematical averages
ANSWER

Dispersion : Dispersion is the tendency of the individual values in a distribution to spread away from the average. Many economic vari8bleSilke income, wage etc., are widely varied from the mean. Dispersion is a statistical measure, which understands the degree of variation of items from the average. Objectives of Measuring Dispersion: Study of dispersion is needed to: 1. To test the reliability of the average 2. To control variability of the data 3. To enable comparison with two or more distribution with regard to their variability 4. To facilitate the use of other statistical measures. Measures of dispersion points out as to how far the average value is representative of the individual items. I f the dispersion value is small, the average tends to closely represent the individual values and it is reliable. When dispersion is large, the

average is not a typical representative value. Measures of dispersion are useful to control the cause of variation. In industrial production, efficient operation requires control of quality variation. Measures of variation enable comparison of two or more series with regard to their variability. A high degree of variation would mean little consistency and low degree of variation would mean high consistency. Properties of a Good Measure of Dispersion : A good measure of dispersion should besimple to understand. 1. It should be easy to calculate 2. It should be rigidly defined 3. It should be based on all the values of a distribution 4. It should be amenable to further statistical and algebraic treatment. 5. It should have sampling stability 6. It should not be unduly affected by extreme values. Measures of Dispersion: 1. Range 2. Quartile deviation 3. Mean deviation 4. Standard deviation 5. Lorenz curve Range, Quartile deviation, Mean deviation and Standard deviation are mathematical measures of dispersion. Lorenz curve is a graphical measure of dispersion. Measures of dispersion can be absolute or relative. An absolute measure of dispersion is expressed in the same unit of the original data. When two sets of data are expressed in different units, relative measures of dispersion are used for comparison. A relative measure of dispersion is the ratio of absolute measure to an appropriate average. The following are the important relative measures of dispersion. 1. Coefficient of range 2. Coefficient of Quartile deviation 3. Coefficient of Mean deviation 4. Coefficient of Standard deviation Mathematical averages In a data distribution, the individual items may have a tendency to come to a central position or an average value. For instance, in a mark distribution, the individual students may score marks between zero and hundred. In this distribution, many students may score marks, which are near to the average marks, i.e. 50. .Such a tendency of the data to concentrate to the central position of the distribution is called central tendency. Central tendency of the data is measured by statistical averages. Averages are classified into two groups. 1. 1.Mathematical averages 2. 2.Positional average

Arithmetic mean, geometric mean and harmonic mean are mathematical averages. Median and mode are positional averages. These statistical measures try to understand how individual values in a distribution concentrate to a central value like average. If the values of distribution approximately come near to the average value, we conclude that the distribution has central tendency. Arithmetic mean is the most commonly used statistical average. It is the value obtained by dividing the sum of the item by the number of items in a series.

MI0051 – LEGAL ASPECTS OF BUSINESS
Q1. “Freedom to contract is a myth or an illusion”. Discuss
ANSWER:

ASSIGNMENT - SET- 2

Freedom to Contract 1. Freedom to contract is a myth or an illusion The freedom of the parties is limited by two factors. There are certain laws for the protection of the employees, and an employer cannot, therefore, induce his employees to enter into any contract favourable to the employer. 2. What is a standard form contract? A standard form contract is a document which is generally printed, containing terms and conditions, with certain blanks to be filled in. It is prepared by the business people. The customer has only to sign it. Therefore, from his standpoint, the freedom to contract is restricted. Many of the contracts now being entered into by consumers are not the result of individual negotiations; rather they are one-sided contracts.

Q2. Distinguish between a contract of guarantee and a contract of indemnity.
ANSWER:

Indemnity and guarantee are two important ways to safeguard ones interests when entering into a contract. There are many similarities between the two concepts though they differ a lot also. Distinction between a contract of guarantee and a contract of indemnity: L.C. Mather in his book „Securities Acceptable to the Lending Banker‟ has brought out the distinction between indemnity and guarantee by the following illustration. A contract in which A says to B, “If you lend Rs. 1 Lac to C, I will see that your money comes back” is an indemnity. On the other hand undertaking in these words, “If you lend 1 Lac to C and he does not pay you, I will pay” is a guarantee. Thus, in a contract of indemnity, there are only two parties, indemnifier and indemnified. In case of a guarantee, on the other hand, there are three parties, the „principal debtor‟, the „creditor‟ and the „surety‟. A guarantee is a promise to someone that a third party will meet its obligation to them. “If they do not pay you, I will pay you”. An indemnity is a promise to be responsible for another person‟s loss and to agree to compensate them for any loss or damage on mutually agreed terms. For example, one agrees to pay the difference of repairs if they exceed a certain limit.

Q3. What is Partnership? Briefly state special features of a partnership on the basis of which its existence can be determined under the Indian Partnership Act?
ANSWER:

Meaning and Nature of Partnership A partnership is defined as “the relationship between persons who have agreed to share profits of a business carried on by all, or by any of them acting for all”. On analysis of the definition, certain essential elements of partnership emerge. Thes e elements must be present so as to form a partnership and are discussed below. 1. Partnership is an association of two or more than two persons. There must be at least two persons who should join together to constitute a partnership, because one person cannot become a partner with himself. These persons must be natural persons having legal capacity to contract. Thus, a company (which is an artificial person) cannot be a partner. Similarly, a partnership firm cannot be a partner of another partnership firm. As regards maximum number of partners in a partnership firm, Sec.11 of the Companies Act, 1956, puts the limit at 10 in case of banking business and 20 in case of any other business. 2. Partnership must be the result of an agreement between two or more persons. An agreement presupposes a minimum number of two persons. As mentioned above, a partnership to arise, at least two persons must make an agreement. Partnership is the result of an agreement between two or more persons (who are known as partners after the partnership comes into existence). 3. The agreement must be to carry on some business. The term „business‟ includes every trade, occupation or profession [Sec.2(b)]. Though the word „business‟ generally conveys the idea of numerous transactions, a person may become a partner with another even in a particular adventure or undertaking (Sec.8). Unless the person joins for the purpose of carrying on a business, it will not amount to partnership. 4. The agreement must be to share profits of the business. The joint carrying on of a business alone is not enough; there must be an agreement to share profits arising from the business. Unless otherwise so agreed, sharing of profits also involves sharing of losses. But whereas the sharing of profits is an essential element of partnership, sharing of losses is not. Example: A, a trader, owed money to several creditors. He agreed to pay his creditors out of the profits of his business (run under the creditors‟ supervision) what he owed to them. Held, the arrangement did not make creditors partners with A in business Formation of partnerships All the essential elements of a valid contract must be present in a partnership as it is based on an agreement. Therefore, while constituting a partnership. The following points must be kept in mind: 1. The Act provides that a minor may be admitted to be benefits of partnership. 2. No consideration is required to create partnership. A partnership is an extension of agency for which no consideration is necessary. 3. The partnership agreement may be express (i.e., oral or writing) or implied and the latter may be inferred from the conduct or the course of dealings of the parties or from the circumstances of the case. However, it is always advisable to have the partnership agreement in writing. 4. An alien friend can enter into partnership, an alien enemy cannot. 5. A person of unsound mind is not competent to enter into a partnership. 6. A company, incorporated under the Companies Act, 1956 can enter into a contract of partnership. Duration of partnership The duration of partnership may or may not be fixed. It may be constituted even for a particular adventure. Partnership at will In accordance with Sec.7, a partnership is called a partnership at will where; (i) it is not constituted for a fixed period of time and (ii) there is no provision made as to the determination of partnership in any other way. Therefore such a partnership has no fixed or definite date of termination. Accordingly death or retirement of a partner does not affect the continuance of such a partnership.

Particular partnership In accordance with Sec.8 a particular partnership is one which is formed for a particular adventure or a particular undertaking. Such a partnership is usually dissolved on the completion of the adventure or undertaking. Limited partnership In this type of partnership, the liability of certain partners is limited to the amount of capital which they have agreed to contribute to the business. In a limited partnership, there will be at least one general partner whose liability is unlimited and one or more special partners whose liability is limited.

Q4. Distinguish between condition and warranty. State the circumstance under which a condition can be waived and treated as a warranty.
ANSWER:

Conditions and Warranties (Sec.11-17) In a contract of sale, parties make certain stipulations, i.e., agree to certain terms. All stipulations cannot be treated on the same footing. Some may be intended by the parties to be of a fundamental nature, e.g., quality of the goods to be supplied, the breach of which, therefore, will be regarded as a breach of the contract. Some may be intended by the parties to be binding, but of a subsidiary or inferior character, e.g., time of payment, so that a breach of these terms will not put an end to the contract but will make the party committing the breach liable to damages. The former stipulations are called „conditions‟ and the latter „warranties‟. Breach of condition to be treated as breach of warranty (Sec.13). Under certain circumstances a breach of condition is to be treated as a breach of warranty, i.e., the right to repudiate the contract is deemed to have been lost. These circumstances are: i) Where a contract of sale is subject to any condition to be fulfilled by the seller, the buyer may either (a) waive the condition, or (b) elect to treat the breach of the condition as a breach of warranty. In such situations, the buyer is active and is either waiving the condition or electing to treat the breach of condition as a breach of warranty. If the buyer decides to waive the condition, he cannot later on insist that the condition be fulfilled. Where the buyer treats the breach of condition as a breach of warranty, he has to give a notice to the seller to that effect. ii) There is also a compulsory treatment of breach of condition as a breach of warranty. Where the contract of sale is not severable and the buyer has accepted the goods or part thereof, the breach of any condition to be fulfilled by the seller can only be treated as a breach of warranty. However, the agreement may provide otherwise, i.e. may permit repudiation of the contract in spite of the acceptance of the goods by the buyer. Express and implied conditions and warranties. Conditions and warranties may be either express or implied. They are said to the „express‟ when the terms of the contract expressly, provide for them. They are said to be „implied‟ when the law deems their existence in the contract even without their actually having been put in the contract. However, an implied condition or warranty may be negative by an express term to the contrary. Sec.62 recognizes the following two principles: i. what is expressed makes what is implied to cease and ii. custom and agreement overrule law. Express condition or warranty. These may be of any kind that the parties may choose to agree upon, e.g., it may be agreed that delivery of goods shall be made or taken on or before a certain date. Similarly, in a contract of sale of a car, express warranty as to its soundness may be incorporated. Implied conditions and warranties [Secs.14-17]. Implied conditions and warranties are deemed to be incorporated by law in every contract of sale of goods unless the terms of the contract show a contrary intention. The implied conditions: i. condition as to title (Sec.14), ii. sale by description (Sec.15), iii. condition as to quality or fitness for buyer‟s purpose (Sec.16(1)), iv. condition as to merchantable quality [Sec.16(2)],

v. condition as to wholesomeness, vi. implied condition in the case of sale by sample (Sec.17), (vii) implied condition in the case of sale by sample as well as description (Sec.15). Doctrine of caveat emptor The doctrine of caveat emptor is a fundamental principle of the law of sale of goods. It means „CAUTION BUYER‟, i.e., „let the buyer beware‟. In other words, it is no part of the seller‟s duty to point out defects of his own goods. The buyer must inspect the goods to find out if they will suit his purpose.

Q5. “A cheque is a bill of exchange drawn on a banker”. Comment..
ANSWER:

Cheques A cheque is the usual method of withdrawing money from a current account with a banker. Savings bank accounts are also permitted to be operated by cheques provided certain minimum balance is maintained. A cheque, in essence, is an order by the customer of the bank directing his banker to pay on demand, the specified amount, to or to the order of the person named therein or to the bearer. Sec.6 defines a cheque. The Amendment Act 2002 has substituted new section for Sec.6. It provides that a ‘cheque’ is a bill of exchange drawn on a specified banker and not expressed to be payable otherwise than on demand and it includes the electronic image of a truncated cheque and a cheque in the electronic from. „A cheque in the electronic form‟ means a cheque which contains the exact mirror image of a paper cheque, and is generated, written and signed in a secure system ensuring the minimum safety standards with the use of digital signature and asymmetric crypto system. Every bank has its own printed cheque forms which are supplied to the account holders at the time of opening the account as well as subsequently whenever needed. These forms are printed on special security paper which is sensitive to chemicals and makes any chemical alterations noticeable. Although, legally, a customer may withdraw his money even by writing his directions to the banker on a plain paper but in practice bankers honour only those orders which are issued on the printed forms of cheques. Requisites of a cheque The requisites of a cheques are: 1. Written instrument. A cheque must be an instrument in writing. Regarding the writing materials to be used, law does not lay down any restrictions and therefore cheque may be written either with (a) pen (b) typewriter or may be (c) printed. 2. Unconditional order. A cheque must contain an unconditional order. It is, however, not necessary that the word order or its equivalent must be used to make the document a cheque., Generally, the order to bank is expressed by the word “pay”. If the word “please” precedes “pay” the document will not be regarded as invalid merely on this account. 3. On a specified banker only. A cheque must be drawn on a specified banker. To avoid any mistake, the name and address of the banker should be specified. 4. A certain sum of money. The order must be only for the payment of money and that too must be specified. Thus, orders asking the banker to deliver securities or certain other things cannot be regarded as cheques. Similarly, an order asking the banker to pay a specified amount with interest, the rate of interest not specified, is not a cheque as the sum payable is not certain. 5. Payee to be certain. A cheque to be valid must be payable to a certain person. „Person‟ should not be understood in a limited sense including only human beings. The term in fact includes „legal persons‟ also. Thus, instruments drawn in favour of a body corporate, local authorities, clubs, institutions, etc., are valid instruments being payable to legal persons. 6. Payable on demand. A cheque to be valid must be payable on demand and not otherwise. Use of the words „on demand‟ or their equivalent is not necessary. When the drawer asks the banker to pay and does not specify the time for its payment, the instrument is payable on demand (Sec.19). 7. Dating of cheques. The drawer of a cheque is expected to date it before it leaves his hands. A cheque without a date is considered incomplete and is returned unpaid by the banks. The drawer can date a cheque with the date earlier or later than the date on which it is drawn. A cheque bearing an earlier date is antedated and the one bearing the later date is called post-dated. A post-dated cheque cannot be honoured, except at the personal risk of the bank‟s manager, till the date mentioned. A post-dated cheque is as much negotiable as a cheque for which payment is due, i.e., the transferee of a post-dated cheque, like that of the cheque on which payment is due, acquires a better title than its transferor, if he is a holder in due course. A cheque that bears a date earlier than six months is a stale cheque and cannot be claimed for.

Q6. Write short note on
ANSWER:

a. Digital signature b. Prospectus

Digital Signature 1. Authentication of electronic records. Authentication is a process used to confirm the identity of a person or to prove the integrity of information. The authentication of message involves determining its source and verifying that it has not been modified or replaced in transit. Subject to the provisions of section 3 any subscriber may authenticate an electronic record by affixing his digital signature. The “hash function” means an algorithm mapping or translation of one sequence of bits into another, generally smaller set known as “hash result” such that an electronic record yields the same hash result every time the algorithm is executed with the same electronic record as its input making it computationally infeasible (a) to derive or reconstruct the original electronic record from the hash result produced by the algorithm; (b) that two electronic records can produce the same hash result using the algorithm. Prospectus 1. A prospectus, as per Sec.2(36), means any document described or issued as prospectus and includes any notice, circular, advertisement or other document inviting deposits from the public or inviting offers from the public for the subscription or purchase of any shares in or debentures of a body corporate. Thus, a prospectus is not merely an advertisement; it may be a circular or even a notice. A document shall be called a prospectus if it satisfies two things: 1. It invites subscriptions to share or debentures or invites deposits. 2. The aforesaid invitation is made to the public. Contents of a prospectus: Sec.56 lays down that the matters and reports stated in Schedule II to the Act must be included in a prospectus. The format of a prospectus is divided into three parts.
1. General information. Under this head information is given about i. Name and address of registered office of the company. ii. Name/(s) of stock exchange/(s) where application for listing is made. iii. Declaration about refund of the issue if minimum subscription of 90 per cent is not received within 90 days from closure of the issue. iv. Declaration about the issue of allotment letters/refunds within a period of 10 weeks and interest in case of any delay in refund, at the prescribed rate, under Sec.73. v. Date of opening of the issue. vi. Date of closing of the issue. vii. Name and address of auditors and lead managers. viii. Whether rating from CRISIL or any rating agency has been obtained for the proposed debentures/preference shares issue. If no rating has been obtained, this should be answered as „No‟. Names and address of the underwriters and the amount underwritten by them. In the first part brief particulars are to be given about matters as mentioned below:

2. Capital structure of the company.
i. ii. Authorised, issued, subscribed and paid-up capital. Size of the present issue, giving separately reservation for preferential allotment to promoters and others. Terms of payment. How to apply. Any special tax benefits. objects. Project cost. Means of Financing (including contribution of promoters.

3. Terms of the present issue.
i. ii. iii. i. ii. iii.

4. Particulars of the issue.

6.Outstanding litigations:

relating to financial matters or criminal proceedings against the company or directors Here in regard to the company and other listed companies under the same under Schedule XIII. management this made any capital issue during the last 3 years.

5. Certain prescribed particulars

2 Stock Exchange Board of India guidelines relating to disclosure on prospectus Every prospectus submitted to Stock Exchange Board of India (SEBI) for vetting shall, in addition to the requirements of Schedule II to the Act, contain/specify certain particulars as are announced from time to time.

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