• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.2355-2358
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• 2003

The purpose of this paper is to investigate two major feature extraction techniques based on generic modular face recognition system. Detailed algorithms are described for principal component analysis (PCA) and independent component analysis (ICA). PCA and ICA ate statistical techniques for feature extraction and their incorporation into a face recognition system requires numerous design decisions. We explicitly state the design decisions by introducing a modular-based face recognition system since some of these decision are not documented in the literature. We explored different implementations of each module, and evaluate the statistical feature extraction algorithms based on the FERET performance evaluation protocol (the de facto standard method for evaluating face recognition algorithms). In this paper, we perform two experiments. In the first experiment, we report performance results on the FERET database based on PCA. In the second experiment, we examine performance variations based on ICA feature extraction algorithm. The experimental results are reported using four different categories of image sets including front, lighting, and duplicate images.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2006년도 춘계학술대회
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• pp.133-140
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• 2006

유비쿼터스 컴퓨팅 기술이 발전함에 따라 상황인지는 유비쿼터스 환경을 구성하는 중요한 요소들 중의 하나로 안정되고 있다. 그러나 아직까지 모든 유비쿼터스 컴퓨팅 환경에 적용될만한 일반적인 상황모형 (generic context model)은 제시되지 못하고 있다. 따라서 본 논문의 목적은 혼합형 다단계(hybrid multi-level) 다이어그램을 이용해 보다 적합한 일반적 상황모형을 제안하는 것이다. 이를 위해 먼저 기존의 다양한 상황 모형들을 분석하고 이를 토대로 유비쿼터스 지능 공간에서의 컴퓨팅 시스템 환경에 적합한 일반적 상황모형을 제안하였다.

• 대한수학회지
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• 제50권4호
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• pp.695-713
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• 2013

We formulate and study a predator-prey model with non-monotonic functional response type and weak Allee effects on the prey, which extends the system studied by Ruan and Xiao in [Global analysis in a predator-prey system with nonmonotonic functional response, SIAM J. Appl. Math. 61 (2001), no. 4, 1445-1472] but containing an extra term describing weak Allee effects on the prey. We obtain the global dynamics of the model by combining the global qualitative and bifurcation analysis. Our bifurcation analysis of the model indicates that it exhibits numerous kinds of bifurcation phenomena, including the saddle-node bifurcation, the supercritical and the subcritical Hopf bifurcations, and the homoclinic bifurcation, as the values of parameters vary. In the generic case, the model has the bifurcation of cusp type of codimension 2 (i.e., Bogdanov-Takens bifurcation).

• 한국시스템다이내믹스연구
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• 제11권1호
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• pp.103-131
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• 2010

This paper aims to investigate a dynamic mechanism underlying the process of knowledge creation and growth with a focus on the 'knowledge-friendly culture' conceptually coined by Davenport and Prusak in 2000. To achieve this objective, key attributes of knowledge are first identified by exploring the generic characteristics and information and interpreting the definitions of knowledge, from which four modes of knowledge growth (Socialization, Externalization, Combination, Internalization) are delineated into a dynamic SECI model by identifying cultural attributes underlying each mode and modeling their casual relationships based on the systems thinking. Further, a series of sensitivity analysis through computer simulation were made to find how 'knowledge-friendly' cultural factors affect the knowledge growth. It is found that individual knowledge is most influenced by organization's cohesion whereas organizational knowledge is most affected by the openness of organization.

• Environmental Analysis Health and Toxicology
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• 제18권3호
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• pp.183-191
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• 2003

Although the variety and quantities of chemicals used have been increasing, no management strategies have been developed for these chemicals in our country. Therefore, it is important to identify the hazardous characteristics of chemicals and establish reasonable and effective management plans for them. However, because insufficient resources are available to evaluate all aspects of many varieties of chemicals, studies on suitable chemical ranking and scoring (CRS) system should be performed to ensure effective screening of priority chemicals.. In addition, because most CRS systems have their own goals, it is impossible for only one generic system to be consistent with all the uses that have been developed. Therefore, priority systems should be developed with specific and clearly defined purposes in our nation. In this study, we investigated and discussed exist-ing CRS systems, and proposed several elements and principles when designing CRS systems. First of all, the system should have clearly defined goals, keep neutral, and employ simple methods. In addition, researchers need to perform sensitivity analysis to find the main variables responsible for uncertainties and use the tiered approach to compose the effective management strategies for chemicals.

• 전기학회논문지
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• 제62권1호
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• pp.95-100
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• 2013

This paper presents a new state feedback control approach for communication networks based control systems in which control input and output observation time-delay natures are generally occurred in practice. We first establish a generic state feedback control framework based on well-known linear system theory. A maximum time-delay value which allows critical stability of whole control system are defined to make a positive definite Lyapunov function which is mathematically composed of controlled system states. We analytically derive its control parameters by using a steepest descent optimization method in order to guarantee a stability condition through Lyapunov theory. Computer simulation is numerically carried out for demonstrating reliability of the proposed NCS algorithm and a comparative study is accomplished to prove its superiority for which the traditional control approach for NCS is made use of under same simulation scenarios.

• Journal of Power Electronics
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• 제16권1호
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• pp.102-110
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• 2016

Contactless power transfer technology is gaining increasing attention in city transportation applications because of its high mobility and flexibility in charging and its commensurate power level with conductive power transfer method. In this study, an inductively coupled contactless charging system for a 48 V light electric vehicle is proposed. Although this study does not focus on system efficiency, the generic problems in an inductively coupled contactless power transfer system without ferromagnetic structure are discussed. An active load matching method is also proposed to control the power transfer on the receiving side through a load matching converter. Small signal modeling and linear control technology are applied to the load matching converter for port voltage regulation, which effectively controls the power flow into the load. A prototype is built, and experiments are conducted to reveal the intrinsic characteristics of a series-series resonant inductive power charger in terms of frequency, air gap length, power flow control, coil misalignment, and efficiency issues.

• 대한원격탐사학회지
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• 제7권1호
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• pp.1-12
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• 1991

토양의 특성은 토지이용에 제한을 가하는 물리적 요소로 활용되고 있으며, 이러한 토양 특성정보는 전통적으로 전문가에 의한 해석에 기초하여 토양도에 서류 형태로 저장, 보관되어 왔 다. 최근에 널리 쓰이기 시작하는 토지정보체계(Geographical Information System, GIS)는 종래의 자료저장, 해석기법을 digital database라는 특성을 이용하여, 새로운 자료분석이 가능한 도구를 제공하게 되었다. 본 연구에서는 위상적으로 체계화된(topologically structured) vector형 토지정 보체계의 관계형 Database Management System(DBMS)과 토양 전문가의 지식을 결합하여 포괄 적인 토양적지 평가모델을 수립한 후, 전문가에 의한 평가, 토양도에 수록된 평가와 각각 비교하 였다. 비교한 결과, 본 연구에서 수립된 토양적지 평가모델은 전문가에 의한 평가와 크게 다르지 않았으며, 이는 토양도의 평가와 비교하여서도 마찬가지였다. 따라서, 본 연구에서 시도된 포괄적 인 토양적지 분석모델은 계속 발전하여 토지정보체계에서의 전문가 기법으로 활용이 가능하다고 판단되어진다.

• 제어로봇시스템학회논문지
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• 제9권10호
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• pp.836-843
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• 2003

The automatic train control (ATC) system development project for the Automated Guideway Transit (AGT) system has high technical risk because the system is unmanned train control system using wireless technology which was unprecedented in train control industry of Korea. To overcome the technical risk during concept design phase of the ATC system development project, the integrated product team(IPT) carried out a reverse and reengineering process using a systems engineering design model. The generic systems engineering process is incorporated in the both reverse and reengineering process. As a result of the systems engineering effort, the IPT has built top layer systems engineering design model of the ATC subsystem. The purpose of this paper is to deliver the reverse and reengineering process which was used to develop the systems engineering design model of ATC system using a computer aided systems engineering tool. This study also shows that the model based reverse and reengineering process can reduce the technical risk by identifying the differences of requirement, functional and physical architecture between a reference system and a target system.

• 전기학회논문지
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• 제60권5호
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• pp.913-920
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• 2011

Distribution systems for operating the various systems should be operated organically. Distribution systems for organic operations extend the functionality of the system and system integration for the extension is doing. However, in systems integration for each unique non-standard definition of linkage and exchange systems are used. Non-standard definition of a unique linkage and exchange systems in the maintenance and expansion will result in many negative results. To solve these problems, the system and the exchange of information about the links between systems should define standards. IEC (International Electrotechnical Commission) power to solve these problems in the field of the Common Information Model (Common Information Model, CIM) standard (IEC61970, IEC61968) is defined as the transmission and distribution system integration and standardization for the exchange of information. In this paper, standardized system for building CIM-based distribution automation system should describe the process of building. In addition, the process of establishing a common information model needed (CIM) defined and associated services for a defined set of models is proposed in the standardization process.