• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2594-2596
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• 2003

유한요소법(FEM)은 많은 공학문제를 해결하는 가장 중요한 방법 중 하나로 인식되고 있다. 본 논문에서는 자동제어 및 신호처리 문제해결에 효율적이며 강력한 수치해석 패키지인 CEMTool환경에서 유한요소법을 이용하여 일반적인 편미분방정식 Solver 구현에 관한사항을 논의하고자 한다. 기본적으로 영역정보 및 노드수 등의 정보를 입력받아 각 노드의 정보를 출력하는 Mesh함수를 구현하며, 생성된 요소방정식들을 조립하는 Assemble함수를 작성한 뒤, Boundary함수를 통해 경계조건을 적용시킨 후 선형행렬 방정식을 풀어 전체노드의 값을 찾아내는 Solve함수를 구현하는 과정을 알아본다. 구현된 FEM Solver의 전체적인 구조를 통해 구현시 고려해야 할 사항을 논의하며 기본적인 편미분방정식의 예제를 통해 FEM PDE Solver의 동작과정을 검증할 것이다.

• Journal of IKEEE
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• v.22 no.4
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• pp.1036-1043
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• 2018

This paper presented future power system protection technologies through the HW/SW integration platform with IEC 61850 and IEEE c37.238 standards. To determine the implementation performance of the integrated platform, an example of EVM (Evaluation Module) was constructed to satisfy the standards. The platform has been identified as a future power system integrated IED(Intelligent Electronic Device) HW/SW technology that meets the level of error required by the time sync standard and the level of delay required by protecting the power system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.11
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• pp.861-869
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• 2013

We consider an information system where viruses arrive according to a Poisson process with rate ${\lambda}$. The information system has two types of anti-virus operation policies including 'real-time scan' and 'batch scan.' In the real-time scan policy, a virus is assumed to be scanned immediately after its arrival. Consequently, the real-time scan policy assumes infinite number of anti-viruses. We assume that the time for scanning and curing a virus follows a general distribution. In the batch scan policy, a system manager operates an anti-virus every deterministic time interval and scan and cure all the viruses remaining in the system simultaneously. In this paper we suggest a probability model for the operation of anti-virus software. We derive a condition under which the operating policy is achieved. Some numerical examples with various cost structure are given to illustrate the results.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.8
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• pp.18-21
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• 2009

In the digital system, ROM has a large power-consumption and a speed-bottleneck. According to gradual growth of system speed, ROM is demanded to have low-power consumption and high-speed operation design. The ROM adapted in FFT or FIR filter needs method of sequential accessed addressing. We proposed a reduction method for the number of storage cells in this paper. The number of storage cells which is connected with bi-line is reduced by the proposed method so that the capacitance value of bit-time is reduced. In this case, delay time, and power consumption are reduced. Design result of ROM in this paper using the proposed method could reduce up to 86.3% of storage cell '1' compare with conventional method.

• Journal of KIISE:Software and Applications
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• v.31 no.6
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• pp.741-749
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• 2004

Component users must customize components they obtain from providers, in order to fit them to their own purposes. Normally, a component consists of black-box parts and white-box parts. Component users customize a component by modifying white-box parts of a component, and the customization faults appear through the interaction between black-box parts and white-box parts. Customization testing could be an integration testing of these two parts of a component. Also, customization testing in CBSD should select effective test data to reduce the testing cost, since CBSD aims to reduce the development cost. Therefore, this paper proposes a customization testing technique based on COM architecture through analyzing many COM components, and the technique selects effective test data. This paper evaluates the effectiveness of the test data selected by the proposed technique through an empirical study. It applies the techlique to a large-scale component-based system, Chamois, and it shows that the technique enables us to test customized COM components that run in a real component-based system

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.696-702
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• 2010

In many industrial applications, it is very important to control the temperature of the controlled object to the target temperature as closely as possible. Although it is apparent that the great obstacles in controller design are time-delay of the thermal responses of the controlled object and the effect of thermal interference between neighboring heating zones, one more fundamental obstacle is a very large amount of time which is required during repeated experiments in controller design process. Therefore, a convenient simulation environment, which can represent thermal behavior accurately within appropriate time, is needed. In this paper, a prototype of 2D FEM (finite element method) heat transfer simulation environment using MATLAB is constructed to be usefully adopted into industrial applications with temperature controller design.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.86-96
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• 2013

Unified Speech and Audio Coding (USAC) is the speech/audio codec with the best quality, approved on Final Draft International Standard (FDIS) at MPEG meeting in 2011. Since MPEG conventionally standardizes only the decoder, it is not easy to study on the encoder technologies. Furthermore, Reference Model(RM) shows extremely poor performance. To solve these problems, the open source project(JAME) proposes the methods to make the improved performance of main encoder technologies in USAC. Especially, this paper introduces the encoder modules: the signal classifier for selective operation between two coders, the psychoacoustic model in frequency domain, and window transition technology. Finally, the results of verification test for FDIS and the performance of Common Encoder are appended.

• Journal of IKEEE
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• v.18 no.1
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• pp.45-56
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• 2014

Recently, damages from disasters such as downpours, earthquakes and typhoons are increasing throughout the world. The downpour days of Korean Peninsula are also increasing every year due to rapid climate change. According to statistics over the last 30 years of the earthquakes in Korean Peninsula, the probability of a future earthquake is very high. In addition, super typhoons will hit Korean Peninsula due to the temperature rise in the nearby sea caused by the deepening of global warming. Thus, damage costs of the waterfront structures by natural disasters are also growing. But damage information system for integrated management of waterfront structures are insufficient. In this paper, we designed and implemented a damage information system for integrated management of waterfront structures. First, we classified damage information caused by natural disaster. Then we designed the databases of damage information and implemented damage information system. Lastly, we checked operations and the feasibility by testing queries on the proposed system.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.103-112
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• 2006

In this paper, we propose a PC based immersive virtual environment system with expandability and compatibility in contrary to existing immersive virtual environment(IVE) systems which have been implemented by supercomputer or special computing system. The application based on commercial personal compute may have two major advantage: one is variety of resources, the other is user-friendly interface. This system intends to offer easy contact to IVE system, realistic images, and convenience. Also, the system can handle various virtual reality at real-time and make it easier to interface existing complicated haptic device. Geometric techniques are adopted to calculate and visualize the physical phenomenon to speed up the computing time. The proposed implementation method of PC based immersive virtual environment system is implemented to the example in which user move around inside of and interact with virtual office environment wearing data glove, behavior recognition devices, and HMD.

• The Journal of Korean Institute for Practical Engineering Education
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• v.2 no.2
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• pp.30-35
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• 2010

This paper proposes several methods for effective teaching of programing language(especially C). The programing languages are very important and basic subjects in the Department of Computer Engineering and Science. Many students have some difficulty in learning the programming languages. So, we will suggest several effective methods for effective teaching of programming languages. First, in order to understand the programming language effectively, we need to teach some basic computer architecture and operation principles of computer program to students. Second, it is better to teach many example-based programing skills instead of conventional grammar teaching. Third, if we teach the memory status(memory allocation/release) during the program operation, it will be much better to understand the pointer variables and memory problems. Fourth, let's improve the programming skills through effective homework assignments and experiments. Fifth, let students be guided so that they do programing by themselves. Finally, we can maximize the programming skill through the final termproject.