TECHNICAL ENGINEER EXAMINATION (NETWORK)(MORNING) pot

1 2001 Autumn Technical Engineer Examination (Network) (Morning) 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 Instructions: 1. Use an HB pencil. If you need to change an answer, erase your previous answer completely and neatly. Wipe away any eraser debris. 2. Mark your answers in accordance with the instructions below. (1) Examinee Number Write your examinee number in the space provided, and mark the appropriate space below each digit. (2) Date of Birth Write your date of birth (in numbers) exactly as it is printed on your examination admission card, and mark the appropriate space below each digit. (3) Answers Select one answer (a through d)) for each question. Mark your answer as shown in the following sample question. [Sample Question] In which month is the Autumn Fundamental Engineer Examination conducted? a) 8 b) 9 c) 10 d) 11 Since the correct answer is “C” (10), mark your answer sheet as follows: [Sample Reply] a) b) c) d) How to Mark Your Answers Right Wrong Faint Do not open the exam booklet until instructed to do so. In q uiries about the exam q uestions will not be answered. 2 Company names and product names appearing in the test questions are trademarks or registered trademarks of their respective companies. Note that the ® and ™ symbols are not included in the test questions. 3 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 c) Checksum d) Humming code 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 Cylinders/disk 800 cylinders Tracks/cylinder 20 tracks Effective recording capacity/track 13,000 bytes Block size 235 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. 4 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. High Low Task A Task B Task C Waiting for release of Resource S Interrupt Interrupt Stop Stop Resource S released Restart Restart Passage of time Resource S secured Execution Execution Priority level Execution 5 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)? a) 0.13 b) 0.17 c) 0.21 d) 0.51 6 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? a) 2 b) 3 c) 4 d) 5 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. 7 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 software development? a) A repository consists of tools used for developing applications and a database for storing data models. b) A repository is a database of software components provided to assist in development. c) A repository is a database used for centralized control of various information used in software development and maintenance. 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. 8 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 9 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? a) 0 20 40 b) 0 1 30 31 c) 0 20 30 40 d) 0 1 20 30 31 Q16. According to the scheduling shown in the figure, how many days are required until Task E can be started? A     B C D E F G Task Required number of days A B C D E F G 3 6 5 3 4 5 3 a) 7 b) 9 c) 12 d) 13  ¦ ¡ ¢ £ ⁄ A B E FC 10 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. . Technical Engineer Examination (Network) (Morning) Questions must be answered in accordance with the following: Question Nos. Q1 to Q50 Question Selection All questions are compulsory Examination. the following sample question. [Sample Question] In which month is the Autumn Fundamental Engineer Examination conducted? a) 8 b) 9 c) 10 d) 11 Since the correct answer is “C” (10),. digit. (2) Date of Birth Write your date of birth (in numbers) exactly as it is printed on your examination admission card, and mark the appropriate space below each digit. (3) Answers Select