• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2531-2533
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• 2002

In this paper, we evaluate feasibility of an object-oriented method in a distributed real-time control environment through the prediction of delay expected. We adopt CAN as the distributed network and the application layer of the CAN is composed of client/server communication model of COM and surroundings for the support of real-time capability of the COM. Mathematical models formalizing delays which are predicted to invoke in the COM architecture are proposed. Sensors and actuators which are widely used in distributed network-based systems are represented by COM objects in this paper. It is expected that the mathematical models can be used to protect distributed network-based systems from violation of real-time features by the COM.

• Journal of the Korea Society of Computer and Information
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• v.20 no.7
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• pp.109-114
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• 2015

With the realization that the police's personal information gathering activities can violate the authority to decide one's information guaranteed by the Constitution, many people are interested in the legal terms of the police's information gathering and handling. The police's personal information gathering activities imply both the purpose of public welfare and order and the risk of violation of basic rights of citizens, their effective balance is critical. In this respect, this study reviews the principle of proportion as a principle of control of personal information gathering and handling (police intelligence activities) by state to discuss its implications on legislation.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.95-100
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• 1990

An optimization method has been developed to find the minimum weight design of steel building structures which consist of the commercially available discrete sections. In this study, an emphasis was particularly placed on the practical applicability of optimization algorithm in engineering practice. The structure Is optimized through element optimization under the element level constraints first and then, if there is any violation of structural level constraints, it is adequately compensated by the constraint error correction vector obtained through the sensitivity analysis. A scaling procedure is introduced for the problems of large violated displacement constraint. The oscillation control in the objective function is also discussed. By dividing the available H-sections into two groups based on their section characteristics, much improved relationships between section variables were obtained and used efficiently in searching the optimum section in the section table.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.123-126
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• 2018

자율 주행 자동차는 다수의 센서와 ECU 등으로 구성된 분산 시스템이다. 이 시스템은 다양한 시간적 제약사항들을 갖는 자율주행 응용들을 구동하며 각 응용들에 대한 시간적 제약사항 위반을 탐지해야한다. 이러한 분산 시스템에서 응용들 간의 통신을 위해 사용되는 미들웨어들 중 대표적인 것은 DDS이다. DDS는 높은 확장성을 지원하는 발행-구독 통신 모델을 기반으로 하며, 실시간성을 고려한 다양한 QoS 정책들을 제공한다. 하지만 DDS는 자율주행 응용이 요구하는 시간적 제약사항들 중 deadline과 correlation 제약 사항에 대한 위반 여부를 탐지하지 못한다. 본 논문은 DDS 기반 시스템에서 deadline과 correlation 제약 사항 위반 여부를 런타임에서 탐지하는 기법을 제안한다. 본 연구진은 제안된 기법을 DDS의 구현들 중 하나인 Vortex 사의 OpenSplice 기반 시스템에 구현하였다. 실험을 통해 검증한 결과, deadline과 correlation 제약 사항에 대한 위반 여부를 적은 오버헤드와 함께 성공적으로 탐지하였다.

• KIEE International Transactions on Power Engineering
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• v.5A no.2
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• pp.152-158
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• 2005

This paper describes a reactive optimal power flow incorporating margin enhancement constraints. Margin sensitivity at a steady-state voltage instability point is calculated using invariant space parametric sensitivity, and it can provide valuable information for selection of effective control parameters. However, the weakest buses in neighboring regions have high margin sensitivities within a certain range. Hence, the control determination using only the sensitivity information might cause violation of operational limits of the base operating point, at which the control is applied to enhance voltage stability margin in the direction of parameter increase. This paper applies an interior point method (IPM) to solve the optimal power flow formulation with the margin enhancement constraints, and shunt capacitances are mainly considered as control variables. In addition, nonlinearity of margin enhancement with respect to control of shunt capacitance is considered for speed-up control determination in the numerical example using the IEEE 118-bus test system.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.368-377
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• 2005

The Internet technologies allows anybody who has connect a network to access various multimedia information. But, it brings new issues about the violation of intellectual property and copyright of multimedia contents. Digital right managements have been actively studied as approaches to solve them. In this paper, we propose license-based schemes for the protection of contents and its rights on digital right management. The proposed schemes provide limited distribution and superdistribution of contents, and guarantee to securely use contents by usage rules.

• Journal of the Korea Society for Simulation
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• v.9 no.3
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• pp.27-41
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• 2000

As the application domains of rule-based systems become larger and more complicated, the integration of rule-based systems within the database systems has become the topic of many research works. This paper suggests a simulation modeling using expert system and database. The integration methods employed in this research are as follows. First, we defined new states and state transition functions to interrelate simulation model and expert system. Second, we designed and implemented FCL(Fact Class Library) as a interface of expert system and database. FCL has facilities of filtering data from database, and assigning a meaning to the filtered data. Also, FCL detects the violation of the integrity rules in database, as the result of inference is reflected. Some implementation problems are pointed out and the methods to solve these problems are discussed in this paper, We developed a simulation model of the grating production line and executed it to validate the functions of the proposed method.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.65-72
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• 2008

The Manchester Driver Behavior Questionnaire (DBQ) is the most commonly used frameworks for investigating the relationship between self-reported driving behavior and accident involvement. After Reason et al. introduced DBQ, there were many studies replicating the research of Reason et al. in many countries. There was, however, no study replication of the Reason's research in Korea. The aim of this study is to replicate the distinction among errors, lapses and violations, and to evaluate the relationship of these behaviors with road traffic accidents on Korean drivers. 223 Korean drivers completed the Korean version of original DBQ with questions regarding background information, such as age, gender, annual mileage and accident involvement. Participants answered self-assessment questions, also. Factor analysis revealed three factors like Reason et al. The three factors were dangerous errors, violations and relatively harmless errors.

• International Journal of Control, Automation, and Systems
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• v.6 no.2
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• pp.160-170
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• 2008

Temperature control of an enclosed thermal system which has many applications including Rapid Thermal Processing (RTP) of semiconductor wafers showed an input-constraint violation for nonlinear controllers due to inherent strong coupling between the elements [1]. In this paper, a constrained nonlinear optimal control design is developed, which accommodates input constraints using the linear algebraic equivalence of the nonlinear controllers, for the temperature control of an enclosed thermal process. First, it will be shown that design of nonlinear controllers is equivalent to solving a set of linear algebraic equations-the linear algebraic equivalence of nonlinear controllers (LAENC). Then an input-constrained nonlinear optimal controller is designed based on that LAENC using the constrained linear least squares method. Through numerical simulations, it is demonstrated that the proposed controller achieves the equivalent performances to the classical nonlinear controllers with less total energy consumption. Moreover, it generates the practical control solution, in other words, control solutions do not violate the input-constraints.

• Journal of the Korean Data and Information Science Society
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• v.16 no.2
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• pp.195-205
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• 2005

In decision tree analysis, C4.5 and CART algorithm have some problems of computational complexity and bias on variable selection. But QUEST algorithm solves these problems by dividing the step of variable selection and split point selection. When input variables are continuous, QUEST algorithm uses ANOVA F-test under the assumption of normality and homogeneity of variances. In this paper, we investigate the influence of violation of normality assumption and effect of the transformation of variables in the QUEST algorithm. In the simulation study, we obtained the empirical powers of variable selection and the empirical bias of variable selection after transformation of variables having various type of underlying distributions.