• Proceedings of the Korean Information Science Society Conference
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• 2006.06c
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• pp.232-234
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• 2006

항공기, 핸드폰, 자동차 등 여러 분야에서 내장형 S/W가 사용되고 있다. 내장형 S/W는 일반 S/W와는 달리 운용 및 개발 환경이 특화되고 다양하여 개발비용이 많이 들고 관리에 어려움이 있다. 이러한 문제점들을 해결하기 위하여 미군에서는 공통운용환경(Common Operating System)을 도입하여 시스템들의 통합을 용이하게 하고 상호운용성을 증진하고 있다. 공통운용환경은 운영체계 및 시스템 S/W는 표준화하고 공통으로 재사용가능한 부분을 일종의 컴포넌트라 할 수 있는 세그먼트로 개발하여 재사용하는 개발 및 운용환경을 말한다. 본 논문에서는 공통운용환경의 컴포넌트 기반 개발 방법을 소개하였다. 그리고 내장형 S/W 개발 및 운용에 필요한 내장형 공통운용환경 구조를 정의하고 세그먼트를 설계하였다.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1052-1057
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• 1993

A scara type Direct Drive Arm(DDA) with two degrees-of-freedom is designed and implemented. The direct drive motor is used to furnish large torque to reduce the modeling error by the gear and chains. To control the DDA, a multiprocessor control structure with multirate dynamic control algorithm is designed. In the control algorithm, the dynamics of system is used to calculate the nominal control torque and the feedback controls are calculated with a parallel processing algorithm for each joint. The laboratory experiments on Hong-Ik DDA by dynamic control algorithm are presented and compared to that of PID control algorithm. This result shows that the proposed controller guarantees small trajectory error and stability. With this research, Hong-Ik DDA is expected to be utilized as A basic tool for robotics and control engineering.

• The Korean Journal of Ceramics
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• v.6 no.1
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• pp.58-63
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• 2000

The preparation of Y-doped $SrZrO_3$powder by ultrasonic spray pyrolysis was investigated as a representative system, in order to produce fine, single phase multicomponent oxide powders. A precursor solution containing metal nitrates, citric acid and ethylene glycol was atomized glycol was atomized with an ultrasonic spray nozzle. Gel particles formed by organic functional groups were pyrolyzed and subsequently calcined at $800^{\circ}C$ to obtain well-crystallized, single perovskite phase. Most of large particles exhibited macroscopic pores and weak agglomeration between primary particles. However, strong agglomeration was observed in the surfaces of large particles. The effect of the microstructures of these particles on size reduction to submicron particles was described.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.945-950
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• 1990

An automatic visual classification system is introduced which provides for measuring the length and diameter of coilform cores and dividing them into 5 different classed in terms of how far their length be from the desired length. This task is fully automated by controlling two STEP motors and by using image processing techniques. The classification procedure is broken into three logical parts, First, cores in the form of randomly stacked bundle are lined up one by one so as to be well captured by a camera. The second part involves capturing core image. Then, it enters the measuring process. Finally, this machine would retain all the information relating to the length. According to the final result, cores are sent to the corresponding bin. This considerably simplifies the selecting task and facilitates a greatly improved reliablity in precision. The average classifying capability is about 2 pieces per second.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.182-186
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• 1997

This paper presents a mathematical approach to implementing distributed optimal power flow (OPF), wherein a regional decomposition technique is adopted to parallelize the OPF. Three mathematical decomposition coordination methods are introduced firs to implement the proposed distributed scheme: the Auxiliary Problem Principle (APP), the Predictor-Corrector Proximal Multiplier Method (PCPM), and the Alternating Direction Method (ADM). Then two alternative schemes for modeling distributed OPF are introduced; the Dummy Generator-Dummy Generator (DGDG) scheme and Dummy Generator-Dummy Load (DGDL) scheme. We present the mathematical analyses of the proposed approach, and demonstrate the approach on several test, systems, including IEEE Reliability Test Systems and parts of the ERCOT (Electric Reliability Council of Texas) system.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.1477-1480
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• 2000

분산서비스거부(Distributed Denial of Service or DDoS)틀 이용한 공격은 공격목표시스템이 보안이 철저하다고 해도 쉽게 공격을 가할 수 있는 공격법이다. 근래에 들어 이러한 공격법은 여러 해킹 툴의 보급과 함께 급격히 증가하고 있다. 하지만, 시스템 자체의 보안만으로 대처 방안이 되지 못하고 있는 실정이다. DDoS 공격을 방지하기 위해서는 전체 시스템들이 모두 보안체계를 갖추고 있어야 하지만, 이것은 현실적으로 불가능하다. 결국 DDoS 공격을 탐지하고 대처하기 위해서는 라우터와 네트워크를 기반으로 한 대응시스템 설계가 요구된다. 또한 DDoS 공격의 재발을 막기 위해서는 DDoS 공격 시스템으로 이용된 시스템을 찾아 악성프로그램을 탐지하고 제거할 수 있는 악성에이전트 탐지 및 제거 시스템을 설계하였다.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.781-783
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• 1996

An important purpose of screening DSM(Demand Side Management) programs is to determine which programs or technologies seem to be moot worthy of further development, given the characteristics of the particular utility system. Complication found in screening DSM technologies is the consideration of costs and benefits from several perspectives : the utility, society, participants, free riders and nonparticipants. In this paper, a nation-wide DSM screening model is presented using a rigorous mathematical formulation on the financial basis and the concept of marginal coots considering all affected parties inside the nation is fully exploited.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1205-1207
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• 1996

The computed-torque method (CTM) shows good trajectory tracking performance in controlling robot manipulator if there is no disturbance or modelling errors. But with the increase of a payload or the disturbance of a manipulator, the tracking errors become large. So there have been many researchs to reduce the tracking error. In this paper, we propose a new control algorithm based on the CTM that decreases a tracking error by generating new reference trajectory to the controller. In this algorithm we used a fuzzy system based on the rule bases. For the numerical simulation, we used a 2-link robot manipulator. To simulate the disturbance due to a modelling uncertainty, we added errors to each elements of the inertia matrix and the nonlinear terms and assumed a payload to the end-effector. In the simulations of several cases, our method showed better trajectory tracking performance compared with the CTM.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.329-331
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• 1994

In this paper, we present a speaker-dependent Korean Isolated digit recognition system. At the preprocessing step, LPC cepstral coefficients are extracted from speech signal, and are used as the input of a Frequency Sensitive Competitive Learning(FSCL) neural network. We carried out the postprocessing based on the winning-neuron histogram. Experimetal results Indicate the possibility of commercial auto-dial telephones.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.456-460
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• 1999

Transparent conducting tin (IV) oxide thin films have been studies and developed for the electrode materials of solar cell substrate. Fabrication of tin oxide thin films by sol-gel method is process development of lower cost photovoltaic solar cell system. The research is focused on the establishment of process condition and development of precursor. The precursor solution was made of tin isopropoxide dissolved in isopropyl alcohol. The hydrolysis rate was controlled by addition of triethanolamine. Dip and spin coating technique were applied to coat tin oxide on borosilicate glass. The resistivity of the thin film was lower than 0.1Ω-cm and the transmittance is higher than 90% in a visible range.