• 제목/요약/키워드: 선택적 공유

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Frequency Reuse Method for Multi-Site Weather Radar (Multi-site 기상 레이다를 위한 주파수 재사용 기법)

  • Lim, Sun-Min;Yoon, Young-Keun;Lee, Young-Hwan;Chong, Young-Jun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.2
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    • pp.109-116
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    • 2014
  • In this paper, we propose a frequency reuse method for efficient frequency use of multi-site weather radar. Our method uses a set of orthogonal pulse compression codes and CLEAN algorithm for sidelobe interference cancellation. Computer simulation results show that performance of proposed method meet performance requirements of [1], The current S-band weather radars in South Korea use the 8 different frequency channels to avoid interference. Using proposed method, number of occupied channels can reduce from 8 to 1, the 7 frequency channels may be use for other services.

Realization of CAT Interface supporting Multitask (다중처리를 지원하는 CAT 인터페이스에 관한 연구)

  • 전동근;노승환;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.12
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    • pp.1423-1436
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    • 1992
  • In the paper, a CAT interface supporting multitask is realized. To interface a computer with measuring instruments, a GPIB card is designed and implemented. Controlling and displaying software using OOP and GUI are programmed with C++. A spectrum analyzer and a power meter are chosen as object instrument to be controlled. Total 9 modules are configured to manage the various resources and each module in integrated system. Also in case that several instruments are used, the system is realized to be capable of multitasking to exchange the data mutually. The multitasking is implemented under the time-sharing DOS environment. Thread-based method is used for processing, and Round Robin method for scheduling. Provided proper software modules for other object instruments are integrated, the system can control more measuring instruments simultaneously by the computer. Users can save the time and errors even without expert knowledge.

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철의장 설계 전산 개발/적용

  • 임대청;이종범
    • Bulletin of the Society of Naval Architects of Korea
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    • v.30 no.2
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    • pp.44-52
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    • 1993
  • 선박에 있어서 철의장품은 종류와 수량이 다양하고 형상이 불규칙하여 대부분의 사업장에서 설계 전산화가 이루어지지 못하고 있는 실정이다. 의장설계실에서는 이를 전산화하기 위하여 먼저 철의장품의 표준을 제정 및 극대화하고 설계작업절차와 물량의 흐름을 전산과 연계하여 체계화 및 표준화하였다. 또한 선박의 전구역에 설치되는 철의장품들을 관련 양식과 함께 국제표준을 근거로 BASICA CADDS, SURFACE DESING, SDDP(structural Design & Detailing Package) SOFTWARE를 이용하여 2차원(2-dimension) 및 3차원(3-dimension) 데이터베이스(database)화 하였으며 이를 POP-UP MENU를 이용, 쉽게 선택함으로써 모델링(modeling) 작업시수를 대폭 감소 시켰으며, 그래픽(graphic)에서 추출한 의장품의 데이터(data)를 의장품의 표준정보 FILE과 연계하여 라벨(LABEL) 및 치수(DIMENSION)를 기입하여 배치도를 추출하고 의장품의 제작, 설치, 계산 및 관리에 소요되는 설치도, 제작도 및 관련 보고서인 BOM(bill of material), PML(pallet material list), 의장제작품 LIST, COG(center of gravity), 관리점 등을 자동추출 및 관리전산망(PC-lan)과 연계할 수 있는 DECOM(철의장 전산설계 전용 package)을 89년에 개 발하여 의장설계에 적용하여 왔으며 ORACLE사의 RDBMS(relational database management system)를 도입하여 이를 보완하므로써 정보의 일관화 및 공유화가 가능하게 되었다. 그 결과 설계 M/H절감, 생산성 향상, 자재 및 관련 정보 전달에 혁신적인 변화 향상을 가져오게 되었다.

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A Simulator for Measuring the Computation Loads of Client/ Server Applications (클라이언트/서버 응용의 연산 부하 측정을 위한 시뮬레이터)

  • Lee, Jun-Yeon;Kim, Dae-Hyeon;Kim, Yeong-Chan
    • Journal of KIISE:Computing Practices and Letters
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    • v.5 no.2
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    • pp.185-195
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    • 1999
  • 1990년대에 들어 컴퓨터 시스템의 급진적 발전으로 인한 소형 컴퓨터의 성능 향상과 가격 하락으로 보급량이 증가하고, LAN/WAN 및 인터넷 통신 기술 발달에 힘입어 여러 분야에서 많은 응용들이 클라이언트/서버 환경에서 개발되고 있다. 클라이언트/서버 환경을 도입하는 이유는 개방형 시스템으로서의 표준화와 자원 공유, 확장성, 가용성, 응용의 생산성 등의 장점 때문이다. 클라이언트/서버 환경에서 운용되는 대부분의 프로그램은 다계층 구조에서 표현계층(사용자 인터페이스) , 응용 로직, 그리고 데이카로 나뉘어질 수 있다. 클라이언트/서버 환경에서 최적의 성능을 얻기 위해서는 어느 자원을 어디로 분산하여야 하는가 하는 것이 문제가 된다. 만약 개발자가 코딩 단계에서 각 노드의 시스템의 부하 정보를 얻을 수 있다면, 클라이언트/서버 환경에서 부하가 적절히 분산된 최적의 프로그램임을 쉽게 개발할수 있다. 본 연구에서는 자바 소스 코드의 분석을 통하여 시스템 부하를 측정할수 있는 시뮬레이터를 개발하였다. 시뮬레이터는 시스템 환경 변수와 자바 소스 코드를 받아들여 모의실험한 후, 응답시간을 라인 그래프 및 막대그래프의 형태로 표현한다. 마지막으로, 시뮬레이터의 정확성을 검증하기 위하여 임의의 프로그램을 선택하여 설제 실행 시간과 본 시뮬레이터에서 측정된 응답시간을 비교, 분석하였다.

Exploring for Impact of Learning Strategies on Participation Level in Online Collaborative Learning Process (온라인 협력학습 과정의 참여 수준에 대한 학습전략의 영향 탐색)

  • Lee, Eun-Chul
    • The Journal of the Korea Contents Association
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    • v.18 no.6
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    • pp.63-72
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    • 2018
  • This study was conducted to explore the impact of learning strategies on the level of participation in the online collaborative learning process. To do this, We studied 91 students who took professorship courses at A university in the Seoul metropolitan area. At the beginning of the semester, the learning strategies were measured through MSLQ, rehearsal, elaboration, organizing, critical thinking, metacognition, learning management, effort control, peer learning, and seeking help. Next, cooperative tasks were carried out to measure the interaction, and group composition consisted of 4-5 persons. The level of participation was measured by scores given to the messages created for interaction. The process of collaborative learning was divided into the steps of identifying learning goals, learning plans, performing individual learning, sharing learning results, and writing reports. The effects of learning strategies on participation level were analyzed through multiple regression analysis (stepwise selection method). As a result, the learning goal step influenced the highest level of metacognition, and the learning plan is the management of the learning time, the demonstration of the learning execution, the adjustment of the effort, the acquisition of help, the collegial learning, Writing was influenced by organization, elaboration, critical thinking, and critical thinking, metacognition, and elaboration.

Self-disclosure and Privacy in the Age of Web 2.0 A Case Study (웹 2.0 시대의 프라이버시 청년 UCC 이용자들의 인식과 실천을 중심으로)

  • Lee, Dong-Hoo
    • Korean journal of communication and information
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    • v.46
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    • pp.556-589
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    • 2009
  • With the advent of the so-called Web 2.0 age, the interconnections of various contents on the web, as well as the user-participatory services from blogs, web-based communities, picture sharing sites, and social networking sites, to the sites for collective knowledge productions, have been further vitalized. As the User Generated Contents(UGCs) are flourishing on the web, they have channeled users' desires for self-expression and social acknowledgement, and yet have created the new kinds of invasion of privacy. This study attempts to look at how the networked individuals' everyday perceptions of privacy have been reconstructed in the age of Web 2.0. By investigating how users have used the UGCs for their sociality on the web and how they have set the boundaries of the private and the public in these public or semi-public disclosures of self-expressions, it has traced the changing perceptions of privacy in everyday communication practices. For this study, it has interviewed Korean youngsters in their 10s and 20s who have grown up with the Internet and have received self-expressions and social communication on the web as everyday activities. Based on their interviews, it inquires into the concurrent notion of privacy and discuss its cultural implications.

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Modeling of Video Data for Sffective Content-based Retrival (효율적인 의미 검색을 위한 동영상 데이터 모델링)

  • Jeong, Mi-Yeong;Lee, Won-Seok
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.4
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    • pp.908-922
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    • 1997
  • In this paper,we present an dffcient way to describe the commplex meaning embedded in video data for the cintent-based retrival in a video database.Intead of viewing the data stored in a file as continuous bit stream,we associate the desired interval in the stream with a set of atteibute and value pairs which describe its meaning.Since the meaning of video data can be cimplex and can change dyamically. It is necessary to com-bine the fixed schema of attributes used in the traditional database systrm with a description method through a set of attribute and value pairs that can be defined dynamically.As the cintent of viedo data can be expressed differently according to the view point of a user,it is important ot maintain the meaning of the attribute and value pairs cinsistently for different users.This paper proposes the dffctive way to manage the set of attri-bute and value pairs.In addition,it also describes a way to define a new video presentation by separating a video stream phsycally or by sharing the portion of a bit stream,and the new method can minimize the required storage space.

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A Study to Generate a Theory of Coordination for Intelligent Agent Societies (지능형 에이전트 집단을 위한 조정 이론 생성에 관한 연구)

  • Kim, Eun-Gyung
    • The KIPS Transactions:PartB
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    • v.9B no.2
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    • pp.147-154
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    • 2002
  • In bulding Intelligent Agent Societies (IAS), it is very important to design and implement coordination in accordance with the known requirement and anticipated working conditions. Coordination consists of a set of mechanisms necessary for the effective operation of IAS. Currently, there is little theoretical support that could help in this research is to generate an empirically-based solving systems in which all agent share an identical goal structure and fully cooperate. And we developed a simulation model called "P-System" which produces basic data to be used for statistical analysis to generate a theory of coordination. Coordination among agent in the P-System is dependent on 23 control variables calld TEs(tweakable emtities.)And the level of coordination is represennted by an independent variabe called QMC (Quality Measure Coordination) expressed in numerical terms according tn the definiion of this study. Also, we have studied how to select unbiased subset from the huge total experimental space of the P-System and how to decide the scale of the subset.

Effective resource selection and mobility management scheme in mobile grid computing (모바일 그리드 컴퓨팅에서 효율적인 자원 확보와 이동성 관리 기법)

  • Lee, Dae-Won
    • The Journal of Korean Association of Computer Education
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    • v.13 no.1
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    • pp.53-64
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    • 2010
  • In this paper, we tried to enable a mobile device as a resource to access to mobile grid networks. By advanced Internet techniques, the use of mobile devices has been rapidly increased. Some researches in mobile grid computing tried to combine grid computing with mobile devices. However, according to intrinsic properties of mobile environments, mobile devices have many considerations, such as mobility management, disconnected operation, device heterogeneity, service discovery, resource sharing, security, and so on. To solve these problems, there are two trends for mobile grid computing: a proxy-based mobile grid architecture and an agent-based mobile grid architecture. We focus on a proxy-based mobile grid architecture with IP-paging, which can easily manage idle mobile devices and grid resource status information. Also, we use SIP(Session Initiation Protocol)to support mobility management, mobile grid services. We manage variation of mobile device state and power by paging cache. Finally, using the candidate set and the reservation set of resources, we perform task migration. The performance evaluation by simulation, shows improvement of efficiency and stability during execution.

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The XP-table: Runtime-efficient Region-based Structure for Collective Evaluation of Multiple Continuous XPath Queries (The XP-table: 다중 연속 XPath 질의의 집단 처리를 위한 실행시간 효율적인 영역 기반 구조체)

  • Lee, Hyun-Ho;Lee, Won-Suk
    • Journal of KIISE:Databases
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    • v.35 no.4
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    • pp.307-318
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    • 2008
  • One of the primary issues confronting XML message brokers is the difficulty associated with processing a large set of continuous XPath queries over incoming XML seams. This paper proposes a novel system designed to present an effective solution to this problem. The proposed system transforms multiple XPath queries before their run-time into a new region-based data structure, called an XP-table, by sharing their common constraints. An XP-table is matched with a stream relation (SR) transformed from a target XML stream by a SAX parser. This arrangement is intended to minimize the runtime workload of continuous query processing. Also, system performance is estimated and verified through a variety of experiments, including comparisons with previous approaches such as YFilter and LazyDFA. The proposed system is practically linear- scalable and stable for evaluating a set of XPath queries in a continuous and timely fashion.