• Journal of Radiation Protection and Research
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• 제1권1호
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• pp.10-14
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• 1976

공동(空洞)크기가 LiF 열형광선량계(熱螢光線量計)의 감응(感應)에 미치는 영향(影響)을 포리에틸렌 매질내(媒質內)에 삽입(揷入)한 구형(球型) 열형광선량계공동(熱螢光線量計空洞)의 가상계(假想系)에서 이론적(理論的)로 연구(硏究)하였다. 크기가 다른 반경(半徑)을 가진 구형공동(球型空洞)의 감응(感應)은 최근(最近)의 공동이론(空洞理論)을 適用(적용)하여 입사광자(入射光子) 에너지의 함수(函數)로서 계산(計算)하였다. 그반경(半徑)은 1.578mm에서 6.528mm까지 취하였고 입사광자(入射光子)에너지는 0.02MeV에서 0.3Mev까지의 범위를 택하였다. 결과(結果)로서 매질내(媒質內)에 삽입(揷入)한 공동(空洞)으로서의 LiF 열형광선량계(熱螢光線量計)의 감응(感應)은 입사광자(入射光子)의 에너지는 물론 선량계(線量計) 자체(自體)크기의 함수(函數)라는 것을 발견(發見)하였다.

• Journal of Information Technology Applications and Management
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• 제12권4호
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• pp.123-131
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• 2005

Since most of the conventional web servers have been designed to Provide the general purpose and user's convenience as the primary goal, there is an overhead to apply them to the embedded system for remote monitoring and controlling the operation status of the Internet appliance. To cope with this overhead, an embedded Linux web server Is suggested in this paper The basic concept is to provide miniaturization and extendability by simplifying the requirements of web server as the services to the requests of web document for the user's menu and the execution of CGI Program for monitoring and controling the Internet appliance, and satisfying only the indispensable requirements of HTTP which are necessary for the interface with the conventional web browsers. For the evaluation of its feasibility, each module has been implemented on Linux environment, and tested with the MS Explorer 6.0.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.99-106
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• 1998

A study was conducted to develope a system for optimum design, safe appraisal and repair works on agricultural structures. Locations of structures were identified using GPS and imbedded into GIS data base with related information. A graphical program assisting ensile field investigation of typical agricultural structural problems such as fractures and cracks of members was developed. Typical rehabilitation methods were coded for data base development. Optimum design programs for several structures were developed and CAD program which automatically draw draft was also developed.

• 시스템엔지니어링학술지
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• 제11권1호
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• pp.67-72
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• 2015

It has been tested for SW reliability in order to prevent the SW error during the development of weapons systems. According to a recent report, defects such as memory leak, buffer overflow, and null deference occur usually in the development stage, but also in the mass production stage. Although it is intended to enhance the SW test and evaluation to prevent SW failures in the development stage, the non-functional problems like syntax errors are not completely revised due to the limitation of the schedule and costs. In addition, SW failure rate are usually fluctuated by the operational environment through SW upgrade in contrast with HW. In this paper, we propose a method to increase SW reliability in the mass production stage of Korean weapon systems.

• 전자공학회논문지A
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• 제31A권1호
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• pp.1-8
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• 1994

In this paper, we have analyzed the performance of a BRAM (The Broadcasting Recognizing Access Method) protocol, as a CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) scheme, which is widely used in wireles LAN systems. We have selected a Fair BRAM protocol among CSMA/CA schemes, considering the fairness of channel usage and the simplicity of the protocol. We have compared the performance of BRAM protocol to that of CSMA/CD. to research the characteristics of BRAM in wireless LAN system. In order to analyze the performance of this system, we have set up an imbedded Markov chain and calculated state transition probabilities. Then we have calculated steady state probabilities and finally derived the throughput of a Fair BRAM moder. To verify our analysis, we have simulated practical models. Then, we have found that analytic results are very close to simulation ones. Our analysis of the BRAM protocol will be expected to be very helpful to design and evaluate a MAC (Media Access Control) protocol in wireless LAN systems.

• 제어로봇시스템학회논문지
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• 제18권6호
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• pp.519-525
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• 2012

Electric brake booster systems replace conventional pneumatic brake boosters with electric motors and rotary-todisplacement mechanisms including ECU (Electronic Control Unit). Electric booster brake systems require precise target pressure tracking and control robustness because vehicle brake systems operate properly given the large range of loading and temperature, actuator saturation, load-dependent friction. Also for the implement of imbedded control system, the controller should be selected considering the limited memory size and the cycle time problem of real brake ECU. In this study, based on these requirements, a sliding mode controller has been chosen and applied considering both model uncertainty and external disturbance. A mathematical model for the electric booster is derived and simulated. The developed sliding mode controller considering chattering problem has been compared with a conventional cascade PID controller. The effectiveness of the controller is demonstrated in some braking cases.

• 중소기업융합학회논문지
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• 제4권3호
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• pp.21-25
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• 2014

Group communications are becoming popular in Internet applications such as video conferences, on-line chatting programs, games, and gambling. Secure and efficient group communication is needed for message integration, confidentiality, and system usability. However, the conventional group key agreement protocols are too much focused on minimizing the computational overhead by concentrating on generating the common group key efficiently for secure communication. As a result, the common group key is generated efficiently but a failure in authentication allows adversaries to obtain valuable information during the group communication. After achieving the secure group communication, the secure group communication should generate the group key efficiently and distribute it to group members securely, so the balance of security and system usage must be considered at the same time. Therefore, this research proposes the software architecture model of a secure and efficient group communication that will be imbedded into networking applications.

• 조명전기설비학회논문지
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• 제19권2호
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• pp.107-113
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• 2005

본 연구에서는 임베디드 리눅스와 HTTP(Hypertext Transfer Protocol) 웹 서버인 GoAhead를 포팅한 32비트 RISC프로세서인 PXA255를 이용하여 웹 서버를 구축하고, 웹 서버를 기반으로 자동차의 순항제어나 무인 운전을 위한 일련의 환경과 상황을 모니터링하고 제어할 수 있는 시스템을 구현하였다. 자동차의 동작 상태와 변화를 감지하기 위해서 ECU와 임베디드 시스템을 인터페이스 시켜 필요한 데이터를 추출하고, 스로를 밸브에 스텝모터를 연결하여 자동차의 엔진을 회전시켜 자동차의 무인 이동을 제어한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.673-676
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• 2003

In this paper, we designed the embedded system used for wireless LAN communication. Embedded system kernel is made from general linux kernel 2.4.18 by applying the ARM patch (2.4.18-rmk7) and the SA1100 patch(2.4.18-rmk7), then porting board level suitable to target system. The SA-1110 PCMCIA interface provides controls for one PCMCIA card slot with a PSKTSEL pin for support of a second slot. The embedded system requires external logic to complete the PCMCIA socket interface. For dual-voltage support, level shifting buffers are required for all SA-1110 input signals. Hot insertion capability requires that each socket be electrically isolated from each other, and from the remainder of the memory system. embedded system is for socket services approaching PCMCIA socket, detecting number of sockets, sensing insertion and removal, and applying power. It also provides interface with Card services. Embedded system supports Host driver for lucent chips that is installed orinoco driver cross compiled. The meaning can say that is doing wireless LAN communication through wireless LAN in imbedded system.

• 인터넷정보학회논문지
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• 제7권2호
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• pp.121-136
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• 2006

재구성(reconfiguration) 기능을 갖춘 SDR(Software Defined Radio) 시스템이 가져야할 소프트웨어 아키텍처와 컴포넌트들 사이에 필요한 프로토콜에 대한 분석을 수행하고 기능 구현을 위한 시스템 설계 내용을 제시한다. 이를 위해 SDR의 기술동향을 분석하고, SDR 시스템을 구축하기 위한 모델을 임베디드 시스템 (Imbedded System)에 입각하여 설계하였다. SDR 시스템 아키텍처는 하드웨어, 운영체제, 미들웨어, 서비스 객체, 응용 계층으로 이루어지는 5계층 구조를 제시한다. SDR 시스템은 리눅스 운영체제 기반에서 구축하였으며, SDR의 주요 특징인 확장성 (scalability)과 재구성 기능이 상호보완적이 되도록 하였다. 5계층 구조에서 SDR의 핵심 기능인 소프트웨어 다운로드 (Software Download) 기능을 구현하기 위한 프로토콜 및 객체의 상태천이도를 수용하는 소프트웨어 설계 내용을 제시한다.