• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.973-974
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• 2008

As radar signal environments become denser and more complex, the capability of high-speed and accurate signal analysis is required for ES(Electronic warfare Support) system to identify individual radar signals at real-time. In this paper, we propose the new novel clustering algorithm of radar pulses to alleviate the load of signal analysis process and support reliable analysis. The proposed algorithm uses KDE(Kernel Density Estimation) and its CDF(Cumulative Distribution Function) to compose clusters considering the distribution characteristics of pulses. Simulation results show the good performance of the proposed clustering algorithm in clustering and classifying the emitters.

• 한국식품위생안전성학회지
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• 제7권1호
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• pp.1-6
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• 1992

Two Rice cultivars , a high yield variety of Cheongcheong and a Korea native kind of Chucheong were grown in paddy. 1$\mu\textrm{g}$ and 10$\mu\textrm{g}$ of aflatoxin B1 and Aspergillus flavus (106 conidia/ml) were inoculated at milk stage. At harvest, kernels from the inoculated plant showed slightly lower ripening rates and 100-grain weight than did those of controls. The nutrient and fatty acid composition of unpolished rice of inoculated group were similar to those of controls and difference between the control and inoculated group were not significantly different.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2001년도 제17회 학술발표회 논문초록집
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• pp.50-53
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• 2001

Flame propagation during the initial stages of ignition in a non-premixed swirl, having some of characteristics of the primary zone of an aero gas turbine combustor, has been investigated. Nd:YAG laser was adopted as the principal ignition source to allow arbitrary placing of the ignition site i subsequent flame development was monitored using a natural light high speed filming technique for many ignition site at two different swirl ratios and an overall equivalence ratio of 0.9. For ignition offset from the burner centreline, buoyancy force associated with radial pressure gradient produced a strong inward movement of the flame kernel. At the burner exit. flame kernels invariably developed into cylindrical form and a 'radial confinement /axia expansion' (RCAE) process was observed.

• 융합보안논문지
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• 제1권1호
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• pp.9-20
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• 2001

전 세계가 정보화의 물결 속에서 보다 신속하고 안전한 정보의 교류를 위한 기술 개발 및 연구는 시간의 변화와 더불어 급변하고 있다 정보의 중요성과 효용가치의 증대는 다양한 분야에서의 기술 발전을 함께 필요로 하게 되었고 특히, 정보보호의 필요성은 그 핵심기술로 자리잡게 되었다. 하지만, 대부분의 시스템 공격이 운영체제의 취약선을 기반으로 하고 있어, 응용 레벨에서의 보안 기술만으로는 소기의 목적을 달성하기에 어려움이 있다. 이런 문제점을 해결하기 위해 운영체제 자체에서 안전하고 신뢰성 있는 서비스를 제공하는 기술에 대한 연구가 많이 이루어지고 있다. 따라서 본 고에서는 현재 보안커널의 세계적인 추세와 동향을 파악하고자 안전한 운영체제 개발 프로젝트들을 소개하고 전자서명 검증을 운영체제 수준에서 수행하여 홈페이지 등의 파일시스템의 위ㆍ변조를 원천적으로 방지하는 File Griffin에 구현된 보안 메커니즘에 대하여 알아본다.

• 방사선산업학회지
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• 제17권3호
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• pp.275-282
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• 2023

Workers in nuclear power plants are likely to be exposed to radiation from various geometrical sources. In order to evaluate the exposure level, the point-kernel method can be utilized. In order to perform a dose assessment based on this method, the radiation source should be divided into point sources, and the number of divisions should be set by the evaluator. However, for the general public, there may be difficulties in selecting the appropriate number of divisions and performing an evaluation. Therefore, the purpose of this study is to develop an algorithm for dose assessment for arbitrary shaped sources based on the point-kernel method. For this purpose, the point-kernel method was analyzed and the main factors for the dose assessment were selected. Subsequently, based on the analyzed methodology, a dose assessment algorithm for arbitrary shaped sources was developed. Lastly, the developed algorithm was verified using Microshield. The dose assessment procedure of the developed algorithm consisted of 1) boundary space setting step, 2) source grid division step, 3) the set of point sources generation step, and 4) dose assessment step. In the boundary space setting step, the boundaries of the space occupied by the sources are set. In the grid division step, the boundary space is divided into several grids. In the set of point sources generation step, the coordinates of the point sources are set by considering the proportion of sources occupying each grid. Finally, in the dose assessment step, the results of the dose assessments for each point source are summed up to derive the dose rate. In order to verify the developed algorithm, the exposure scenario was established based on the standard exposure scenario presented by the American National Standards Institute. The results of the evaluation with the developed algorithm and Microshield were compare. The results of the evaluation with the developed algorithm showed a range of 1.99×10^-1~9.74×10^-1 μSv hr^-1, depending on the distance and the error between the results of the developed algorithm and Microshield was about 0.48~6.93%. The error was attributed to the difference in the number of point sources and point source distribution between the developed algorithm and the Microshield. The results of this study can be utilized for external exposure radiation dose assessments based on the point-kernel method.

• 대한기계학회논문집B
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• 제24권11호
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• pp.1486-1496
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• 2000

The initial flame kernel development and flame propagation in a constant volume combustion chamber is analyzed by the heat release rate and the mass fraction burnt. The combustion pressure is measured with a piezoelectric type pressure sensor. In order to evaluate the effects of ignition system and ignition energy on the flame propagation, four different ignition systems are designed and tested, and the ignition energy is varied by the dwell time. Several different spark plugs are also tested and examined to analysis the effects of electrodes on flame kernel development. The results show that the when the dwell time is increased, and when the spark plug gap is extended, heat release rate and the mass burnt fraction are increased. The materials and shapes of electrodes affect the flame development, because they change the energy transfer efficiency from electrical energy to chemical energy. The diameter of electrodes influences not only the heat release rate but also the mass burnt fraction as well.

• 한국자동차공학회논문집
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• 제3권1호
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• pp.54-64
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• 1995

The effects of swirl on early flame development and late combustion characteristic were investigated using a high speed single-shot visualized 51 engine. LDV measurements were performed to get better understanding of the flow field in this combustion chamber. Spark plugs were located at half radius (R/2) and central location of bore. High speed schlieren photographs at 20,000 frames/sec were taken to visualize the detailed formation and development of the flame kernel with cylinder pressure measurements. This study showed that high swirl gave favorable effects on combustion-related performances in terms of the maximum cylinder pressure and flame growth rate regardless of spark position. However, at R/2 ignition the low swirl shown desirable effects at low engine speed gave worse performances as engine speed increased than without swirl. There were distinct signs of slow-down in flame growth during the period when the flame front expanded from 2.5mm in radius until it reached 5.0mm apparently due to the presence of ground electrode. There seemed to be heat transfer effect on the flame expansion speed which was evidenced in high swirl case by the slowdown of the late flame front presumably caused by relatively large heat loss from burned gas to wall compared with low- or no-swirl cases.

• 수산해양기술연구
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• 제23권3호
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• pp.111-116
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• 1987

이상으로부터 다음의 결론을 얻는다. 조파저항 이론의 전개에서 Michell 적분보다 더욱 정밀한 Neumann-Kelvin 문제가 복잡한 kernel 함수 때문에 많은 시간과 노력이 필요하지만, 원점 부근에서 Kelvin 소오스의 점근거동을 조사하여 세장체 근사를 행함으로 N-K 문제의 kernel 함수에 대한 근사와 동등하게 처리될 수 있었다. 조파저항의 계산 결과가 Michell 적분과 비슷한 경향을 보이나, 실험치와의 정확한 비교를 할 수 없었다. 그러나 세장선 이론을 적용함으로써 훨씬 복잡하고 지루한 작업을 들 수 있었다. 전진 속도를 갖는 경우에는 수정된 Green정리를 이용하면 될 것으로 기대된다.

• 한국정보통신학회논문지
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• 제11권8호
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• pp.1528-1534
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• 2007

본 논문은 지능형 Gadget 시스템의 개발환경 구현에 관한 논문이다. 지능형 Gadget 시스템에서 사용된 임베디드시스템 응용 프로그램과 리눅스 커널의 구조 및 동작에 대해 논하고 지능형 Gadget 시스템에 필요한 기능 및 구성 요소에 대해 조사 및 분석을 통한 리눅스 커널과의 동작 및 기능 검증 구현을 보인다. 새로운 지능형 임베디드 시스템의 하나인 Gadget 시스템에 적용 가능하도록 요구되는 기능과 동작을 구현하고 새로운 소형 운영 체제를 위한 개발에 적용 가능하다. 그러한 소형 운영체제는 지능형 개인정보서비스를 위한 임베디드 Gadget 시스템으로써 지능형 정보화 기능을 지원하고 새로운 소형 운영 체제를 탑재한 시스템의 개발에 적용 가능하다. 본 논문에서는 그러한 지능형 임베디드 Gadget 시스템과 응용 개발을 위한 개발환경 구현에 대하여 기술한다.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.151-158
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• 2002

Automotive engineers involved in a new car project use various CAD systems that are chosen based on work requirements. For example, engineers in Hyundai Motors are using Pro/Designer and Alias fur the style design, but they use CATIA to design parts and assemblies, ANSYS for FEM analysis, and Pro/Engineer to design engines. Because they use different CAD systems, they have difficulties in collaborative design. Data, which contains errors, is transferred between CAD systems. It is difficult to find out such errors in a large CAD model. An evaluation method for CAD models has been developed in this study. This diagnosis tool analyses a STEP or an IGES file generated from a CAD system, and produces a quantitative error report. The tool has been tested with actual data sets. This paper proposes an algorithm that produces mathematical error values of entities of IGES models that have geometrical data, and entities of STEP models that have topological data, and inspects every part off model. To develop this system, we have used the OpenCASCADE kernel, which is an open source kernel developed by Matra Datavision of France.