• Title/Summary/Keyword: Computers

Search Result 3,674, Processing Time 0.032 seconds

A Flash Memory Swap System for Mobile Computers (모바일 컴퓨터를 위한 플래시 메모리 스왑 시스템)

  • Jeon, Seon-Su;Ryu, Yeon-Seung
    • Journal of Korea Multimedia Society
    • /
    • v.13 no.9
    • /
    • pp.1272-1284
    • /
    • 2010
  • As the mobile computers are becoming powerful and are used like general-purpose computers, operating systems for mobile computers also require swap system functionality that utilizes main memory efficiently. Flash memory is widely used as storage device for mobile computers but current linux swap system does not consider flash memory. Swap system is tightly related with process execution since it stores the contents of process in execution. By taking advantage of this characteristics, in this paper, we study a new linux swap system called PASS(Process-Aware Swap System), which allocates the different flash memory blocks to each process. Trace-driven experimental results show that PASS outperforms existing linux swap system with existing garbage collection schemes in terms of garbage collection cost.

A Fault-Tolerant Scheme Based on Message Passing for Mission-Critical Computers (임무지향 컴퓨터를 위한 메시지패싱 고장감내 기법)

  • Kim, Taehyon;Bae, Jungil;Shin, Jinbeom;Cho, Kilseok
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.18 no.6
    • /
    • pp.762-770
    • /
    • 2015
  • Fault tolerance is a crucial design for a mission-critical computer such as engagement control computer that has to maintain its operation for long mission time. In recent years, software fault-tolerant design is becoming important in terms of cost-effectiveness and high-efficiency. In this paper, we propose MPCMCC which is a model-based software component to implement fault tolerance in mission-critical computers. MPCMCC is a fault tolerance design that synchronizes shared data between two computers by using the one-way message-passing scheme which is easy to use and more stable than the shared memory scheme. In addition, MPCMCC can be easily reused for future work by employing the model based development methodology. We verified the functions of the software component and analyzed its performance in the simulation environment by using two mission-critical computers. The results show that MPCMCC is a suitable software component for fault tolerance in mission-critical computers.

Awareness and Perception of Computer Ethics by Undergraduates of a Nigerian University

  • Oyewole, Olawale
    • Journal of Information Science Theory and Practice
    • /
    • v.5 no.4
    • /
    • pp.68-80
    • /
    • 2017
  • The invention of computers is one of the best things that have ever happened to mankind and undergraduate students can benefit immensely from the use of computers. However, observations have showed that in the present Nigerian society, there are a number of issues arising from unethical use of computers. Interactions with some undergraduate students revealed that a majority have fallen into the trap of unethical use of computers at one time or another. This seemingly alarming rate of unethical use of computers therefore calls for concern. A literature search has shown that awareness and perception of computer ethics have not been adequately researched within the Nigerian context. Thus, the main objective of this study was to examine the awareness and perception of computer ethics by undergraduate students in a Nigerian university. Descriptive survey research method was used and the study population was comprised of 12,894 undergraduate students of the University of Ibadan, Nigeria. The multistage random sampling technique was used to select a sample size of 292 and the questionnaire was used to collect data. Findings showed that the level of awareness of respondents on issues associated with computer ethics was high (mean=45.19). A majority of the respondents had a favorable perception of computer ethics and the most prominent factor identified that could hinder adherence to computer ethics as noted by most of the respondents was the poor economic situation of the country. Part of the recommendations was that government at all levels should provide responsible and responsive leadership.

A Study on System for Synchronization of Multiple UAVs and Ground Control System (무인이동체 및 지상국 컴퓨터 간의 시간 정보 동기화를 위한 시스템 연구)

  • Lee, Won-Seok;Lee, Woon-Sang;Song, Hyoung-Kyu
    • Journal of the Semiconductor & Display Technology
    • /
    • v.19 no.1
    • /
    • pp.11-16
    • /
    • 2020
  • In this paper, system that includes multiple unmanned aerial vehicles (UAVs) are considered. The vehicles are equipped with a mission computer for a specific mission and equipment. The mission equipment operates based on the time of mission computer. Also, data collected by flight computer and mission computer is saved with the time of each operating system. Generally, time offset between multiple computers always exists, though the computers are connected to the Internet. When the data collected by multiple computers is combined, the time offset causes damage on reliability of the combined data. Computers that connected to the Internet are synchronized by network time protocol (NTP). This paper proposes a system that the time of multiple mission computers are synchronized by the same NTP server to minimize the time offset. In the results of the measurement, the system time offset of multiple mission computer is maintained within 10ms from the system time of the server computer.

Hardware implementation of a conventional cryptosystem for personal computers (퍼스널 컴퓨터용 관용 암호화 시스템의 구현)

  • 강성기;이진수;이상곤;문상재
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
    • /
    • 1991.11a
    • /
    • pp.176-184
    • /
    • 1991
  • A realization of a conventional cryptosystem for personal computers using the DSP56001 digital signal processing chip is presented. An improved Lucifer-type algorithm is employed to encrypt, and executed in the DSP56001. The Diffie-Hellman method is employed to generate and distribute the key. The implemented hoard can be plugged in the I/O port of personal computers.

  • PDF

A study on the Design Techniques and Analysis of Fault-Tolerant Computers

  • Cho, Jai-Rip
    • Journal of Korean Society for Quality Management
    • /
    • v.21 no.1
    • /
    • pp.78-95
    • /
    • 1993
  • The art of designing and analyzing fault-tolerant computers is surveyed with special emphasis on problems of analyzing the behavior of computers that have autonomous repair capability. The survey covers the following topics : (1) general issues in computer reliability, (2) fault-tolerance state relations and requirements, (3) computational hierarchy, (4) fault characteristics, (5) fault diagnosis, (6) fault-tolerance schemes for logic network and machines, (7) fault-coverage effects, and (8) fault-tree analysis of coverage. This paper does not include techniques for verifying nonredundant hardware or system software designs or for verifying the correctness of application programs.

  • PDF

Development of A Wearable Input Device Recognizing Human Hand and Finger Motions as A New Mobile Input Device

  • Dae H. Won;Lee, Ho G.;Kim, Jin-Y;Park, Jong H.
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.153.3-153
    • /
    • 2001
  • Recently, the researches on the mobile computing technologies for palm computers, PDA´s and wearable computers became very active. In the development of mobile devices, one of the key technologies is the human interface. So, this paper suggests a new input device for PDA´s and wearable computers so-called key-glove. The design methods of key-glove are discussed in this paper and we manufactured the key-glove which recognizes that character is typed in though the hand´s movements analysis and is designed as an input device for wearable computers and virtual environment. Also, we are executes a performance test for alphanumeric data entry, command entry and X-Y pointer input. In the results, we are confirmed in its ...

  • PDF

Gender Disparities in the Use of ICT: A Survey of Students in Urban Schools

  • Basavaraja, M.T.;Sampath Kumar, B.T.
    • Journal of Information Science Theory and Practice
    • /
    • v.5 no.4
    • /
    • pp.39-48
    • /
    • 2017
  • This study aims to investigate gender differences in the use of ICT by the students of urban schools. The objectives of the study are to find out the use of computers and Internet by the students and also the problems encountered by them while using computers and Internet. The study found that there is a significant association between the place (p=.005) and frequency (p=.002) of use of computers and gender. It is also found that there are significant differences in the problems faced by students while using computers (p=.002), use of Internet (p=.004), and the gender. This clearly indicates that there exists a gender disparity in the use of ICT by the male and female students in the urban schools. In order to overcome this disparity, the school authority should provide the basic and necessary ICT infrastructure in schools which can be equally used by male and female students.

Teacher's Viewpoints on the Desirability of Computers In the Early Childhood Classroom: A Qualitative Study (유아컴퓨터 교육환경 조성에 관한 교사의 욕구 탐색 ; 질적 접근)

  • Sim, Hyeon Ae;Lee, So Hee
    • Korean Journal of Child Studies
    • /
    • v.18 no.1
    • /
    • pp.177-198
    • /
    • 1997
  • This study investigated the viewpoint of teachers on the desirability of computer education in the early childhood classroom. The subjects were 8 kindergarten teachers in Seoul and Kyong'gi Province who used computers in the classroom. Nondirective and open-ended interview methods were used for data collection. Five steps or stages of viewpoints were found: step1-teachers want to have computers in the classroom but have no particular purpose in mind; Step 2-teachers want the children to play with the computers as if it were a toy; Step 3-teachers want to use any programs that are in the computer; Step 4-teachers want to use the computer more purposefully for educational goals; Step 5-teachers want to unify the early childhood curriculum through the multi-media system.

  • PDF

Selections and applications of statistical packages for personal computers (개인용 컴퓨터에서의 통계페키지의 선택과 활용)

  • 김병천
    • The Korean Journal of Applied Statistics
    • /
    • v.1 no.1
    • /
    • pp.75-90
    • /
    • 1987
  • Statistical data analysis using the statisticaal packages can be performed on the personal computers. But it is not easy to select a personal computer in which statisticians could run statistical packages. The paper discusses some of the minimum requirements of the personal computers to use statistical packages and how to choose good statistical packages with better numerical results and introduces the statistical packages which are available in the personal computers.