• 제목/요약/키워드: Computer I/O

검색결과 601건 처리시간 0.025초

휴대용 데이터베이스를 위한 지연된 소거 리스트를 이용하는 플래시 메모리 쉐도우 페이징 기법 (Flash Memory Shadow Paging Scheme Using Deferred Cleaning List for Portable Databases)

  • 변시우
    • Journal of Information Technology Applications and Management
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    • 제13권2호
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    • pp.115-126
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    • 2006
  • Recently, flash memories are one of best media to support portable computer's storages in mobile computing environment. We propose a new transaction recovery scheme for a flash memory database environment which is based on a flash media file system. We improved traditional shadow paging schemes by reusing old data pages which are supposed to be invalidated in the course of writing a new data page in the flash file system environment. In order to reuse these data pages, we exploit deferred cleaning list structure in our flash memory shadow paging (FMSP) scheme. FMSP scheme removes the additional storage overhead for keeping shadow pages and minimizes the I/O performance degradation caused by data page distribution phenomena of traditional shadow paging schemes. We also propose a simulation model to show the performance of FMSP. Based on the results of the performance evaluation, we conclude that FMSP outperforms the traditional scheme.

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전력계통 자동화 시스템의 MMI 한글화에 관한 연구 (A Study on the Hanguel implemention for the MMI of the SCADA system)

  • 최성수;이영훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 A
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    • pp.183-185
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    • 1993
  • The SCADA (Supervisory Control And Data Acquisition) system made by HARRIS corporation of U.S.A for special propose industrial computer is currently used for Power control in KEPCO (Korea Electric Power corporation). But it's I/O expression is composed or only alpha-numeric and semi-graphic characters. So operators have had some troubles and difficulties. We have studied and implemented Hanguel (Korean Character) in this system to solve these difficulties. In this paper we'll discuss the method and technics of Hanguel Implementation on SCADA system, and trendency of Hanguel implementation will be added.

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전기로 온도제어를 위한 화면감시 제어기 설계 (A Design of a Screen Monitoring Controller for the Electric Furnace Temperature Control)

  • 오진석
    • 한국안전학회지
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    • 제12권2호
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    • pp.80-86
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    • 1997
  • In this paper, a temperature controller with monitor function is proposed for the electric furnace system. This controller includes holding and ramp control function, and the control program for the temperature process monitor of the electric furnace. For this purpose, the implementation and performance of auto tuning algorithms in a computer-based controller was studied in relation to the control of nonlinear electric furnace system which is characterized with large delay time. The control program for this controller programmed by c-language. To communicate a control and detection signals, between the controller and the electric furnace is implemented by the I/O data card. We apply the temperature controller to the practical electric furnace. As a result, the proposed controller shows the better status characteristic.

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Feasibility and Performance Analysis of RDMA Transfer through PCI Express

  • Choi, Min;Park, Jong Hyuk
    • Journal of Information Processing Systems
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    • 제13권1호
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    • pp.95-103
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    • 2017
  • The PCI Express is a widely used system bus technology that connects the processor and the peripheral I/O devices. The PCI Express is nowadays regarded as a de facto standard in system area interconnection network. It has good characteristics in terms of high-speed, low power. In addition, PCI Express is becoming popular interconnection network technology as like Gigabit Ethernet, InfiniBand, and Myrinet which are extensively used in high-performance computing. In this paper, we designed and implemented a evaluation platform for interconnect network using PCI Express between two computing nodes. We make use of the non-transparent bridge (NTB) technology of PCI Express in order to isolate between the two subsystems. We constructed a testbed system and evaluated the performance on the testbed.

반도체 회로를 이용한 정전기제거에 관한 연구 (A Study On The Control Techniques Of Electra-Static Discharges Using Semiconductor Circuits)

  • 오홍재;박기주;김병인;김남오;김형곤;김덕태
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 제4회 영호남학술대회 논문집
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    • pp.19-24
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    • 2002
  • Static electricity is an everyday phenomenon. There can be few of us who have not experienced a static shock after sliding across a car seat. Other static nuisance effects include the cling of some fabrics to the body, the sticking of a plastic document cover, or the attraction of dust to a TV or computer screen. However, static electricity has been a serious industrial problem. The age of electronics brought with it new problems associated with static electricity and electrostatic discharge. And, as electronic devices became faster and smaller, their sensitivity to ESD increased. In this work, We are study on the control technique of electo-static discharges using semiconductor circuits. Our circuits are prevented well to electrostatic shock or damages from triboelectric charging in cars everyday life.

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An Empirical Performance Analysis on Hadoop via Optimizing the Network Heartbeat Period

  • Lee, Jaehwan;Choi, June;Roh, Hongchan;Shin, Ji Sun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권11호
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    • pp.5252-5268
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    • 2018
  • To support a large-scale Hadoop cluster, Hadoop heartbeat messages are designed to deliver the significant messages, including task scheduling and completion messages, via piggybacking to reduce the number of messages received by the NameNode. Although Hadoop is designed and optimized for high-throughput computing via batch processing, the real-time processing of large amounts of data in Hadoop is increasingly important. This paper evaluates Hadoop's performance and costs when the heartbeat period is controlled to support latency sensitive applications. Through an empirical study based on Hadoop 2.0 (YARN) architecture, we improve Hadoop's I/O performance as well as application performance by up to 13 percent compared to the default configuration. We offer a guideline that predicts the performance, costs and limitations of the total system by controlling the heartbeat period using simple equations. We show that Hive performance can be improved by tuning Hadoop's heartbeat periods through extensive experiments.

AI의 이동통신시스템 적용 (Artificial Intelligence Applications on Mobile Telecommunication Systems)

  • 예충일;장갑석;고영조
    • 전자통신동향분석
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    • 제37권4호
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    • pp.60-69
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    • 2022
  • So far, artificial intelligence (AI)/machine learning (ML) has produced impressive results in speech recognition, computer vision, and natural language processing. AI/ML has recently begun to show promise as a viable means for improving the performance of 5G mobile telecommunication systems. This paper investigates standardization activities in 3GPP and O-RAN Alliance regarding AI/ML applications on mobile telecommunication system. Future trends in AI/ML technologies are also summarized. As an overarching technology in 6G, there appears to be no doubt that AI/ML could contribute to every part of mobile systems, including core, RAN, and air-interface, in terms of performance enhancement, automation, cost reduction, and energy consumption reduction.

모델기준형 적응제어를 이용한 전기유압 서보계의 제어에 관한 연구 (A study on control of electrohydraulic servosystem with using model reference adaptive contorl theory)

  • 김기홍;윤일노;박재범;김종겸;염만오
    • 한국정밀공학회지
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    • 제14권5호
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    • pp.92-99
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    • 1997
  • A model reference adaptive control(MRAC) theory is very useful for controlling a plant of which the parameters are unknown or vary during operation usint only input-output signal of plant. In this study, 2' nd order discreter time MRAC controller is designed for an electrohydraulic position control system which is represented with nonlinear mathematical model and the least square method is adopted for the para-meter adjustment law. This control algorthm is applied to the position control of electrohydraulic servosystem through computer simulation and the effect of the change of load, sampling time upon the performance following reference model and upon the performance of estimating plant parameters are examined.

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대용량 데이터 색인에 적합한 역파일의 구현 (Implementation of the Inverted File for Indexing Large-volume Data)

  • 임성채
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2008년도 추계학술발표대회
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    • pp.909-912
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    • 2008
  • 대용량 문서에 대한 키워드 검색을 위해 역파일(inverted-file) 색인 기법이 널리 쓰이고 있다. 역파일 색인 기법을 구현함에 있어 고려되어야 할 점은 키워드 검색 처리 시에 디스크 사용을 최소로 할 수 있는 방법이다. 크기가 작은 역파일이라면 디스크 I/O 사용도 작고 필요시 역파일을 메모리에 적재하여 둠으로써 디스크 사용을 크게 줄일 수 있다. 하지만, 웹 검색이나 규모가 큰 도서관 시스템에서와 같이 색인 데이터 크기가 매우 큰 경우 역파일을 읽는 디스크 비용이 급격히 증가할 수 있다. 본 논문에서는 매우 큰 크기의 역파일을 사용하는 검색 환경에서 디스크 사용을 최소로 할 수 있는 역파일 구조를 제안한다. 제안된 구조는 질의 처리 과정을 고려해 계층 구조로 설계되며 실제 상용 시스템에 적용되어 안정성 및 성능을 입증했다.

TFA-MOD법으로 제조된 YBCO 박막의 습도분압 효과 (The humidity effect of YBCO film by TFA-MOD process)

  • 장석헌;임준형;윤경민;이승이;김규태;이창민;주진호;나완수;이희균;홍계원
    • Progress in Superconductivity
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    • 제8권1호
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    • pp.65-70
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    • 2006
  • We fabricated $YBa_2Cu_33O_{7-x}$(YBCO) films on(00l) $LaAlO_3$ substrates prepared by metal organic deposition(MOD) method using trifluoroacetate(TFA) solution and evaluated the effects of the humidity on the microstructure, phase purity, and critical properties. The films calcined at $430^{\circ}C$ were fired at $775^{\circ}C$ at 0%, 4.2%, 12.1%, and 20.0% humidified As gas mixed with 0.1% $O_2$. We observed that the amount of $BaF_2$ phase was effectively reduced and that a sharp and strong biaxial texture formed under a humidified atmosphere, leading to increased critical properties. For the films fired at 0% humidity, the $T_c\;and\;I_c$ were undetectably small. When the humidity was increased to 4.2%, the corresponding $T_c$(onset) and $I_c$ were increased to 90.5 K and 8 A/cm-width, respectively. For the films at the humidity range of 12.1-20.0%, the $I_c$ was found to be 35 A/cm-width. According to the results of the XRD, pole-figure, and SEM, these improved critical properties are probably attributed to the formation of a purer YBCO phase, larger grain size, and stronger c-axis orientation.

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