Computer in management july 2003

COMPUTER IN MANAGEMENT MBA – 3.22JULY - 2003

Q1 (a). What is System Bus ? What is Word size ?What is difference between Mhz and MIPS ?

(b). What are the differences between PROM , SDRAM , and Cache L1 ? (c). What are the major components of Mother board ? What do you mean by a Chip set ?

Ans. (a) System Bus : A single route to which several items of a computer system may be connected in parallel so that signals can be passed between them .

A Bus is also called a Trunk in US and a highway in UK . The signal on a bus may be only of a particular as in an Address

Bus or Data Bus or they may be intermixed . The number of lines in the bus should equal to the

sum of the number of bits in a data word , the maximum address , and the number of control lines .

Word size : The number of bits , referred to as the Word Length Or Word Size . The memory of computer is divided

into words i.e.. subdivided into Bytes . A Word is long enough to contain an instruction or

an integer .

Difference between Mhz and MIPS :

Frequency is measured in Hz or Cycles per second and 1024 Hz = 1Khz or 1024 Khz = 1Mhz .

Cycles ( Analog signals ) that are made in 1 second is called Frequency of that signal , whereas Instruction rate is

measured in bits per second .1024 instruction per second = 1 KIPS 1024 KIPS= 1 MIPS

(b). Difference between PROM , SDRAM , and Cache L1 :

PROM : PROM stands for Programmable Read-only Memory . A form of semi-conductor read-only memory , ROM ,

Whose contents are added by a separate process after the device has been manufactured .

This process of programming the PROM is accompli- -shed by means of a device known as a PROM Programmer .

SDRAM : SDRAM stand for Static - Dynamic Random Access Memory .Static RAM are fabricated from either bipolar or MOS components . Dynamic RAM cells , which comprise MOS

Device ,the cell contents must be refreshed at regular intervals .

Static RAM and Dynamic RAM have larger cell densities typically up to 64 K cells on chip , but slower access times .

Cache L1 : A type of memory , used in high-performance system, Inserted between the processor and memory .

A memory hierarchy on a system contains registers in the processor , which are the highest-speed storage , and at a slightly lower level of Accessibility ,the contents of the memory .

The cache is intended to reduce the discrepancy in accessibility between these two types of unit , and functions by holding small regions that map the contents of main memory .

(c). Major Components of Mother board : The following are the major components of Mother board :

i. RAMii. ROM

iii. Cache Memoryiv. Batteryv. Modem slot

vi. Printer slotvii. HDD slot

viii. Floppy drive slotix. CD-ROM / Writer slotx. Sound card slot

xi. Power supply slotxii. NIC ( Network Interface Card ) slot

Chip set : A set of integrated circuits that when connected together from a single functional block within a computer system .

Q2 (a). How many operating systems you are familiar with ? Write the name of minimum five of them . (b). What are the major difference between Windows 98 and Window95 mention about their size ? (c). What are 4GLs ? What are the difference between application gen-

-erators and application software packages ? (d). What are the new trends in software capabilities ?

Ans. (a) I am familiar with 12 Operating System .

1. UNIX / LINUX2. OS23. MAC4. Macintosh5. WINDOWS 9X

(b). Difference between Windows 95 and Windows 98 :

Windows 95 has not User Account facility Whereas Windows 98 has .Windows 98 more secure rather than Windows 95 . Peer-to-peer networking is easier in Windows 98 rather than Windows 95 .

(c). 4GLs : 4GLs stands for Fourth Generation Languages also called Non-procedural Languages . The Non-proce-

-dural Language implies a program by “specifying the desired result , rather than specifying action required to achieve that result” .

4GLs encompasses of broad array of data base query and reporting languages , program and application generators and other very high level Non-procedural language .

4GLs paradigm includes some or all of following tools :

Non-procedural language for database query, report gene- -ration , data manipulation , screen interaction and definition , and code generation ; high-level graphics capabilities and spre- -adsheet capability .

Difference between Application Generators and Application Languages :

Application Packages : A suite of programs or modules i.e.. directed at generic application and

can be tailored to the needs of specific instance of that application

Application Languages : Languages which can be used to design an Application Packages is

called the Application Language .

For example : C , C++ , ADA , FLEX , Euclid

Q3. (a) What are the components of Communication System ? (b) Write five differences between Coaxial cable and Optical fiber ?

(c) What is the difference between Analog and digital signals ? How analog signal is converted into digital signal ?

Ans. (a) Components of Communication System : The components of communication

system are :

Source : This device generates the data to be transmitted . For example : Phones and Personal computers .

Transmitter : A transmitter transforms and encodes the Infor- -mation such a way to produce electromagnetic

signals that can be transmitted across of transmission system .

Transmission System : This can be a single transmission lineor a complex network connecting

source and destination .

Receiver : The receiver accepts the signal from the transmis- -sion system and converts it into a form that can

be handled by destination device . For example : A modem will accept an analog signal coming

from a network or transmission line and convert it into a digital bit stream .

Destination : Takes the incoming data from the receiver .

(c). Difference between Analog signal and Digital signal :

Analog signal Digital signal1. Analog signal is a continuous electromagnetic waves that may be propagated over a media depending on freq- -uency .2. For example : Copper wire media , such as Twisted pair and Coaxial cable , Fiber optic cable and atmosphere or space propagation ( wireless ) .3. Analog data can be represe- -nted by digital signals .

4. Analog data are encoded to occupy a different portion of spectrum .

1. Digital signal is a sequence of voltage pulses that may be transmitted over copper wire medium .

2. For example : A constant positive vol- -tage level may represent binary 1 and a constant negat- -ive voltage level may repres- -ent binary 0 .3. Digital data can be represent- -ed directly , in binary form , by two voltage levels .4. Analog data are encoded using a codec to produce a digital bit stream .

Analog signal converted into Digital signal : Analog signal is converted into Digital signal by either of two methods :

1. PCM ( Pulse code Modulation )2. Delta Modulation ( DM )

PCM is based on Sampling theorem whereas DM is binary behavior .

Q4. (a) What is the difference between LAN , WAN , and MAN ?(b) Describe in brief major network topologies . Write their advantages and Disadvantages ?(c) Define the terms Modem , Protocol , Ethernet , and Broadband ?(d) Describe network services such as ATM , Frame Relay , and ISDN ?

Ans. (a) Difference between LAN , MAN , WAN :

LAN MAN WAN1. LAN stands for 1. MAN stands for 1. WAN stands for

Local Area Netw- -ork .2. Used Guided Media

3. A communication network linking a number of stations in same local area .

4. LAN generally pro- -vide a high-speed 100 Kbps to 100 Mbps .

Metropolitan Area Network .2. Used may be Guided or may be Unguided media .3. This network share the characteristics of packet broad-casting networks .

4. A MAN is optimized for a large geographi- -cal area than LAN .

Wide Area Net- -ork .2. Used Unguided media .

3. A communication network distingu- -ished from a Local Area Netw- -ork .4. Its long distance communications , which may or may not be provi- -ded by public packet network .

(b). Network Topologies : The common topologies are Bus , Tree , Ring , and Star .

1. Bus topology : Bus are characterized by the use of a multi- -point medium . In Bus , all stations attach through hardware interfacing known as Tap directly to a linear tran- -smission medium or bus .

Full duplex operation between the station and the tap allows the data to be transmitted onto the bus and received from bus .

Advantage is that Low installation cost and Disadvantage is that If cable break-down all the network will be

down .

2. Tree topology : The tree topology is a generalization of Bus topology . The Tree layout begins at a point known as the Headend , where one or more cables start and each of

these may have branches . Advantage is that faster data rate and Disadvantage is that High Installation rate .

3. Ring topology : The network consist of a set of repeaters joined by point-to-point . The repeater is a device of

receiving data on one link and transmitting them , bit by bit on other link as fast as they are received .

The links are unidirectional i.e.. data are trans- -mitted in one direction only . Data circulate around the ring in one direction .

Advantage is that Low communication cost

And Disadvantage is that If Ring is break-up then whole Ring is Divided into two parts .

4. Star topology : In Star topology , each station is directly con- -nected to a central node , referred to as the

star coupler , via two point-to-point links , one for transmission in each direction .

The central node to act as a frame switching device . An incoming frame is buffered in the node and then retrans-

-mited on an outgoing link to the destination station . Advantage is that No installation cost with

Unshielded twisted pair and Disadvantage is that If two devices Transmit it the same time , there will be a collision .

(c). Modem : Modem combined with two words Modulator and Demodulator . A device that can convert a digital bit

Stream into an analog signal for transmission over some communic- -ation channel is called Modulation and can convert incoming

analog signals back into digital signals known as Demodulation . Modems are used to connect digital devices across

Analog transmission lines .

Protocol : An entity is capable of sending or receiving information and a system is a physically distinct object that contains one or more entities .

The key elements of Protocol are : i. Syntax : Includes such things as data format , coding , and

signal levels .ii. Semantics : Includes control information for co-ordination and error handling .

iii. Timing : Includes speed matching and sequencing .

HDLC is an example of Protocol .The data to be exchanged must be sent in frames of a specific format .

Ethernet : The most commonly used medium access control techniques for bus/tree and star topologies is Multiple

access with collision detection or CSMA / CD . CSMA / CD can be termed random access or conten-

-tion techniques .They are random access that there is no predictable or scheduled time for any station to transmit ; station transmissions are ordered randomly .

An important rule followed in CSMA / CD systems , Including the IEEE standard , is that frames should be long enough

to allow collision detection prior to the end of transmission .

Broadband : Communication uses a Modulation to apply a data signal to a transmission medium in analog form .

Multiple signal can be present simultaneously using Frequency division multiplexing . Ethernet are inherently broadband in nature . Communication systems that use Broadband networking techniques on Coaxial cable .

There are two classifications of Broadband Coaxial system . In one way system signal travel in only one direction in the cable . This kind of system is Cable TV systems .

In two-way system signals can travel in both directions on the cable .Two-way systems fall into mid-split or sub- -split categories .

(d). ATM : ATM stands for Asynchronous Transfer Mode . ATM is widespread application its use as part of broadband .

ATM does not provide error control and flow control mechanisms . ATM is the data transfer interface for B-ISDN . ATM is not based

on HDLC ,but it is based on completely new frame format known as cell , that provides minimum processing overhead .

The cell has a fixed length of 53 octets or 424 bits .

Frame Relay : Frame Relay is a data link control facility designed to provide a capability for use over high-speed packet-switched networks .

Frame relay provides a more efficient packet Switching than X.25 and widespread use , not only in ISDN but in

other networking context . A critical component of Frame relay is conges-

-tion control .

ISDN : The ISDN is intended to be a worldwide public Telecommunications network to replace existing

Public telecommunications networks . ISDN support of a wide range of voice and non-

-voice applications in same network . ISDN support a variety of applications including

both switched and non-switched connection . An ISDN will contain intelligence for the purpose

of providing service features , maintenance and network manage- -ment functions .

ISDN will be based on the concepts for telephoneIDN . ISDN support both circuit switching and packet switching .

Q5 . (a) What are the three components of database management system ?(b) What are the advantages of database approach over traditional file

Approach ?(c) What are the elements of SQL ?(d) What is the difference between a Foreign key and Primary key ?(e) What is entity integrity ? What is a relation ?

Ans. (a) Components of Database management system : The comp- -onents of

DBMS following are :

1. DDL Compiler : DDL compiler processes schema defi- -nations , specified in the DDL , and ,

stores description of the schemas in the DBMS catalog . The catalog includes information as

the name of file , data items , mapping information among schemas and constraints .

2. Run-time database processor : It handles database accesses at run time ; it

receives retrieval or update operations on the database . The query compiler handles high-level queries that are entered interactively .

3. Pre-compiler : The pre - compiler extracts DML commands from an application program

written in a host programming language . These commands are sent to the DML compiler for compilation into object

code for database access .

(b) Advantages of database over traditional file approach :

1. Controlling Redundancy2. Restricting Unauthorized Access3. Providing Multiple user interfacing4. Providing Backup and Recovery5. Representing complex relationship among data6. Enforcing integrity constraints

(c) Elements of SQL : SQL language provides a high-level

declarative language interface . SQL includes some features from relational algebra but is based on the tuple relational calculus .The SQL syntax is more user- -friendly than either of two formal languages .

SQL stands for Structured query Language . SQL was called SEQUEL ( Structured English

Query Language ) . SQL is a comprehensive database language . It has statements for data definition , query , and update . Hence , it is both a DDL and a DML .

It has facilities for defining views on the Database , for specifying security and authorization , for defining Integrity constraints and for specifying transaction controls .

(d) Difference between a Foreign key and Primary key :

Foreign Key Primary Key

1. A foreign key can refer to its own relation .

2. One or more Foreign key can be treated in Parent table .3. Foreign key constraints can be defined at the column or table constraint level .

1. The Primary key clause speci- -fies one or more attributes that make up primary key of a relation .2. One Primary key can be treated for each table .

3. Primary key constraint is a column or set of columns that uniquely identifies each row in in a table .

(e). Entity integrity : The entity integrity constraint state that no Primary key value can be NULL , because

the primary key value is used to identify individual tuple in a relation having NULL values .

Key constraints and entity integrity constraints are specified on individual relations .

Relation : A relation is an association among several entities .A relation is a set of relationship of the same type .

A relation may also have descriptive attributes . The number of

entity set that participate in a relationship is also the degree of therelationship set .

Q6. (a) It has been said that you do not need database management Software to create a database environment . Discuss .

(b) What is Schema ? Explain with the help of an example .(c) What are the different types of data models ? Explain in brief .

Ans. (a) To create a database it is not necessary to adopt a database management system we can create its own database system with the help of some conventional languages like C , C++ ,VB etc. But this type of database system require complex programming , complex retrieval , complex query management . Due to this reason ,we adopt the database management environment . So that , the retrieve our data easily and with consistently .

(b) Schema : The DBA ( Database Administrator ) creates the database schema by a set of definitions , that is ,

translated by the DDL compiler , i.e.. stored permanently in the Data dictionary .

The description of a database is called the database Schema , which is specified during database design .

The three-schema architecture is to separate the user Applications and the physical database :

1. The Internal level has an Internal schema , which describes of the database .The internal schema uses a Physical data model .

2. The conceptual level has a conceptual schema , which describes the structure of the whole database

for a community of a user .A high-level data model or an impl-

-ementation data model can be used at this level .

3. The External or View level includes a number ofExternal schemas or User views . Each External

schema describes the part of database that a partic--ular user group is interested in and hides the rest ofthe database from the user group .

For example : A schema for a Student and a Course are

STUDENT

Name Student number Class Major

COURSE

Course name Course number Credit hours Department

(c). Data Models : A collection of concepts that can be used to the structure of a database . By structure of

a database , the data types , relationships , and constraints that should hold on data .

Categories of data model are : 1. High-level or Conceptual data model provides concepts

that are close to many users perceive data .

2. Low-level or Physical data model provide concepts that describe the details of how data is stored in the computer

3. Representational or Implementation data models ,which provide concepts that may be understood by end users

but that are not too far removed from the way data is

organized within the computer .

4. Conceptual data models use concepts as –entities , attri- -butes and relationship . Entity-relationship model a popular high-level conceptual data model .

Q8. (a) How WWW is different from TFTP ? (b) What is relationship between TCP/IP and Internet ?

(c) What is difference between Intranet and LAN ? (d) What is meaning of Firewall ? Name other security

mechanism of E-commerce ?

Ans. (a) Difference between WWW and TFTP :

WWW : WWW stands for World Wide Web or Web is A system that has made to access any docum-

-ent on the net , including sound , pictures , video . On the WWW , information is displayed in the

Form of Web pages . The Web pages can hold :

1. Formatted text2. Pictures3. Audio4. Video

Web pages also contain Hyperlink. Hyperlink are text or other objects that are linked to other pages .

TFTP : TFTP stands for Trivial File Transfer Protocol , supports the transfer of small

Files without user authentication . It transfers 512-byte packets using unacknowledged UDP services .

RFC 1350 defines TFTP . The syntax of TFTP is that : tftp [ -i ] host [ get / put ] source [ destination ]

-i This option is used to transfer the file in Binary mode , byte-by-byte .

(b) Difference between TCP / IP and Internet :

TCP / IP : TCP / IP stands for Transmission Control

Protocol / Internet Protocol .TCP imple- -ments reliable connections between hosts . It is also resp- -onsible for the delivery of packets in correct order .If data

are lost , TCP is responsible for automatic retransmission of the lost data .

Whereas IP provides tha datagram service . An IP datagram is a self-contained packet of information

i.e.. forwarded by routers using address on the packet . IP is a communication protocol that provide

a datagram service .

Internet : The Internet or Net , it is referred to a Network of Networks .The TCP/IP transfer

Protocol provides the bindings that connect all computers .The Internet Protocol is used to break-down the data intoPackets that are transferred over the network . The Transm--ission Control Protocol keeps track of these data packets and reach the destination .

The WWW is a subset of Internet .

(c) Difference between Intranet and LAN :

Intranet : An Internet is a “network that uses Internet -based technologies within an organization

to facilitate communication and access to information .” Intranet are typically based on Web Framework .

There are three types of people who design and use the Intranet :

1. Users : Are the people in the organization who will use the Intranet to get information .

2. Information Providers : Are the internal groups which provides the requ-

-ired information . 3. Developers : Are the people who develop tools ,

applications or gateways to applic- -ations across the organization .

LAN : LAN stands for Local Area Network ,which Wide-spread in same building . The scope

of LAN is small , a single building or a cluster a building.

The internal data rates of LAN are typically

much greater than Intranet .

(d). Firewall : Firewall are technique that most organisa- -tion use to maintain the integrity of their

information . “ A network firewall is a system or group

of systems that forces an access control policy between two networks .”

It gives auditing , logging ,alerting facility. It can hide the internal private network . It can support The remote dial-in user authentication .

Other security mechanism of E-commerce :

1. RSA data security2. DES ( Data Encryption standard ) security