TECHNICAL ENGINEER EXAMINATION (NETWORK)(MORNING) pot

Which of the following is the most accurate statement regarding the number of cylinders required if the blocking factor is 2, 6 and 8, respectively.. Item Specification Effective recordi

2001 Autumn

Questions must be answered in accordance with the following:

Question Nos Q1 to Q50

Question Selection All questions are compulsory

Examination Time 9:30-11:00 90 minutes

Select one answer (a through d)) for each question

Mark your answer as shown in the following sample

Q1 Which of the following is used as a memory error control system with 2-bit error detection

function and 1-bit error correction function?

a) Odd parity b) Horizontal parity

Q2 The specifications for a magnetic disk device are shown in the table One record stores

1,000 bytes of data Which of the following is the most accurate statement regarding the number of cylinders required if the blocking factor is 2, 6 and 8, respectively For this problem, assume that there are 10,000 or more records?

Item Specification

Effective recording capacity/track 13,000 bytes

a) The number of cylinders required when the blocking factor is 2 is less than when the blocking factor is 6

b) The number of cylinders required when the blocking factor is 6 is less than when the blocking factor is 8

c) The number of cylinders required is greatest when the blocking factor is 6

d) The number of cylinders required is smallest when the blocking factor is 8

Q3 Consider a system where main storage is accessed twice per instruction on average and

there is 40 ms of overhead per access when a page fault occurs How low must the frequency of page faults be in order to make the delay per instruction due to page faults 0.4

um or less? For this problem, ignore overhead when there is no page fault

a) 5×10-6 b) 1×10-5 c) 5×10-5 d) 1×10-4

Q4 Consider a real time system where there are three tasks A, B and C of descending level of

priority If Task A is waiting for the release of a resource currently secured by Task C, and

B becomes executable, Task B, which has a lower priority level than Task A, will execute first Which of the following is an appropriate method of preventing a reversal in the priority levels of Tasks A and Task B?

a) Make the priority level of Task A temporarily the same as Task C

b) Make the priority level of Task B temporarily the same as Task A

c) Make the priority level of Task B temporarily the same as Task C

d) Make the priority level of Task C temporarily the same as Task A

Q5 In case of two-phase commit protocol used for distributed transaction processing, there is a

coordinator, which starts commit processing, and a participant, which starts necessary actions after receiving instructions from the coordinator Which of the following is the most accurate statement regarding two-phase commit protocol?

a) If the participant returns a “commit OK” response to the coordinator in Phase 1, commit processing proceeds locally even if a Phase 2 commit request is not received b) If the coordinator becomes blocked, depending on the point where the problem occurred, a situation occurs where no participants can perform commit or rollback until recovery processing has ended

c) It is possible for more than one coordinator and participant to exist for a single distributed transaction For example, when five systems (programs) are involved, the number of coordinators may be 2 and the number of participants may be 3

d) The coordinator can forcibly commit a transaction even in the case, where there is a participant which gives no response in Phase 1

Q6 Consider a certain online system which handles 5,000 transactions per hour and has an

average processing time of 0.3 seconds/transaction

Assuming that an M/M/1 wait queue model can be applied to the processing of this online system, what is the approximate average processing time per transaction (in seconds)?

Q7 Which of the following is the most accurate statement regarding improvement to system

performance in terms of capacity management?

a) Even if the clock frequency of the CPU is doubled, job throughput is not necessarily doubled Therefore the system need to be enhanced together with peripherals

b) In the case of a virtual storage system, increasing the capacity of auxiliary storage decreases the average CPU time per job

c) Assuming that a single server system is an M/M/1 wait queue model, the average response time can be represented in a normal distribution graph Therefore the results

of analyzing peaks in the graph are reflected in planning

d) In a transaction processing system, if the number of transactions which arrive per unit

of time increases by a factor of n (where n = 2, 3, ), hardware must be enhanced out

of consideration of the fact that the average response time also increases by a factor of

n

Q8 Consider a component with a reliability of 0.9 We wish to increase reliability by

connecting this component in parallel so that if even one of these components fails, the prescribed function can be achieved At least how many components are required to achieve an overall reliability of 0.9999?

Q9 Which of the following is the most accurate statement regarding failsafe?

a) Even if the system malfunctions, the system is always controlled on the safe side b) If a fault occurs in the system’s functions, operations continue by reducing the functions performed without immediately stopping the system

c) System reliability is increased by equipping it with more than one of each of those system components which greatly impacts reliability

d) The system is designed in such a way that malfunctions can hardly happen even if an unspecified number of people operate it

Q10 Which of the following is the most accurate statement regarding data mining?

a) Data mining is taking a large volume of data and analyzing it using statistical techniques to uncover hidden rules and interrelationships which cannot be found merely by searching

b) Data mining is taking some of the data stored in a data warehouse and storing in a database for a particular application or special use

c) Data mining is the act of defining data structures, meanings, and an operational framework based on the information which will be the object of data processing d) Data mining is storing multiple attributes in a database, performing various types of analysis in a short period of time using combinations of different attributes

Q11 Which of the following is the most accurate statement regarding a repository used in

d) A repository consists of software used for analysis of source programs used to perform reverse engineering and a database used to store the results of that analysis

Q12 Which of the following is the most accurate statement regarding the characteristics of

Java?

a) A Java compiler converts source code into a byte code, and a virtual Java machine executes the byte code

b) A browser is required to execute programs developed using Java

c) It is necessary to re-compile programs developed in Java in order to execute them on other platforms

d) Due to security concerns, an applet can only communicate with machines running a browser

Q13 Which of the following is a list of graphic symbols used in DFD?

a) Relationship, entity, attribute

b) Source/sink, entity, data flow

c) Source/sink, data store, process

d) Attribute, data store, data flow

Q14 Which property of the object-oriented concept allows data or methods from a higher order

class to be re-used by a lower order class?

a) Inheritance b) Encapsulation

c) Abstraction d) Polymorphism

Q15 Assume that you want to test a program that outputs a header and 30 records on a single

page as an output ledger Prepare test data to test boundary values of this program Which

of the following combinations of values have the same value class as setting the number of records to 0, 1 through 30, and 31 or higher for the same value class?

Q17 Which of the following statements regarding work management charts describes the

characteristics of a Gantt chart?

a) Expressing the order of tasks and their interrelationships, and useful in understanding which tasks are important, a Gantt chart is used in task planning for projects

b) Although it is difficult to understand the interrelationships between tasks, a Gantt chart

is useful in grasping actual output resulting from scheduled work, and is used in progress management for individuals and groups

c) Useful in expressing time transitions, a Gantt chart is used to understand and anticipate time transitions

d) Useful in progress management for understandings milestones, a Gantt chart is used in progress management for individuals

Q18 A system failure occurred while using a database, and has been recovered up to the status

represented by checkpoint t1 Which of the five transactions, TR1, TR2, TR3, TR4 and TR5, must be rolled forward? For this problem, assume that at a checkpoint an information log is produced that includes information about the transaction executing at that point in time and the update history of the database, and that information is also written to the database

Q19 Which of the following is the most accurate statement regarding lock operations used in

simultaneous execution control?

a) Common lock requests generated during common lock are accepted

b) Exclusive lock requests generated during common lock are accepted

c) Common lock requests generated during exclusive lock are accepted

d) Exclusive lock requests generated during exclusive lock are accepted

Q20 To decrease communication network costs, line multiplexing hardware (indicated by in

the figure) has been installed for the communication network that directly connects the head office in Tokyo with each branch office What is the monthly economic benefit of this

in hundreds of dollars? For this problem, assume that the monthly cost of lines between each office in the old and new networks is as indicated in the figure Also assume that the multiplexing hardware was installed under a lease agreement at a monthly rate of 2% of it's full cost of 30 thousand dollars per unit The cost of communication equipment such as modems may be ignored

Nagoya branch office

Kyoto branch office

Osaka branch office

Nagoya branch office

Osaka branch office

Q21 Which of the following is the most accurate statement regarding frame sequence number

control for HDLC protocol?

a) When the receiver receives correctly an I frame whose transmission sequence number

is equal to the receive status variable, “1” is added to the receive status variable

b) The control sections of the data transmission (I) format and the supervision (S) format

both include transmission sequence numbers

c) In the case of an 8-bit I frame, a transmission sequence number ranging from 0 to 127

is applied

d) When an I frame is sent, the sender sets the send sequence number to a value of one

greater than the value of the send status variable

Q22 What is the maximum length (in bytes) of TCP data that can be included in one frame

when performing TCP/IP communications under conditions given in the table using

Ethernet connections where the maximum transfer unit (MTU) is 1,500 bytes?

Total length of non-data sections (preamble, destination address, originating

address, protocol type, CRC) of the Ethernet frame format 26

Q24 Which of the following is a connectionless protocol used on the Internet and placed in the

network layer of the OSI basic reference model?

Q25 Which of the following is the most accurate statement regarding IPv6?

a) IPv6 is designed so that no problems occur even if a global IP address is duplicated b) IPv6 is designed to resolve the problem of insufficient global IP addresses

c) IPv6 is designed to support Internet connections via communication satellites

d) Ipv6 is designed to support Internet connections using optical fiber

Q26 How many host addresses can be assigned as Class B IP addresses under TCP/IP?

Q27 Which of the following is the most accurate statement regarding OSPF?

a) Routing is done by the link state algorithm that includes the concept of areas

b) OSPF is an exterior gateway protocol used between regions that employ different management policies

c) Under OSPF, it is impossible to dynamically change the route based on operational status of the network

d) As a routing protocol based on the load between adjacent nodes, OSPF does not take costs into consideration

Q28 Which of the following is the most accurate description of RARP—protocol related to

TCP/IP?

a) RARP is a protocol which queries MAC addresses based on the IP addresses

b) RARP is a protocol that is used for error control of the IP protocol

c) RARP is a protocol that resolves MAC addresses to IP addresses

d) RARP is a protocol which dynamically creates a routing table while exchanging routing information

Q29 Which information is included in a TCP header field, but not in a UDP header field?

a) Destination port number b) Sequence number

c) Sender port number d) Checksum

Q30 Once a PPP link is established, a challenge message is sent at fired periods to the other

party, and that party responds to the message with a value calculated using a hash function Which protocol identifies other parties in this way?

Q31 Which of the following is the most accurate statement regarding ITU-T Recommendation

X.25?

a) Using the multiplexing method of X.25, one timeslot inside a frame is pre-assigned for each terminal

b) The network layer of X.25 is connectionless

c) When a frame is lost due to a transmission error, recovery processing is triggered by the notification of a sequence error

d) LAPD is used for the transmission control protocol procedures

Q32 Which of the following is the most accurate statement regarding connectionless

communication?

a) When communicating using UDP, which is one type of connectionless

communication, connectionless communication for line switching and leased lines is not performed

b) Information indicating the destination is added to all packets to be sent

c) Connectionless communication always assumes a connection type called “PVC” under which the other party and a communication path are pre-set so that communications can be performed without any connection operations being performed

d) Since connections are established and released separately for each packet, connectionless communication is not particularly suited to large volume data communications

Q33 IEEE 802.3 is a LAN access standard that uses the CSMA/CD method Of the layers

contained in the OSI basic reference model, which is the topmost layer defined in IEEE 802.3?

a) Session layer b) Data link layer

c) Transport layer d) Network layer

Q34 Which of the four protocols LAPGB, MHS, X.21 and X.25PLP is second from the top

when they are listed in order according to the corresponding OSI basic reference model hierarchy?

(mod2 calculation in all cases)

As long as at least one of c0, c1 or c2 is non-zero,

i = c0 + c1 × 2 + c2 × 4

is calculated, and errors are corrected by reversing the i-th bit from the left

Which of the following is the correct code word on the sender side when the 7-bit code word received is 1000101?

a) 1000001 b) 1000101 c) 1001101 d) 1010101