• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.1 s.232
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• pp.139-144
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• 2005

A vehicle cruise control algorithm using an Interacting Multiple Model (IMM)-based Multi-Target Tracking (MTT) method has been presented in this paper. The vehicle cruise control algorithm consists of three parts; track estimator using IMM-Probabilistic Data Association Filter (PDAF), a primary target vehicle determination algorithm and a single-target adaptive cruise control algorithm. Three motion models; uniform motion, lane-change motion and acceleration motion. have been adopted to distinguish large lateral motions from longitudinal motions. The models have been validated using simulated and experimental data. The improvement in the state estimation performance when using three models is verified in target tracking simulations. The performance and safety benefits of a multi-model-based MTT-ACC system is investigated via simulations using real driving radar sensor data. These simulations show system response that is more realistic and reflective of actual human driving behavior.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.759-762
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• 2014

반도체소자의 제조 공정 기술 중 구리패턴을 얻기 위해서 사용하는 화학.기계적 연마(CMP)를 이용한 평탄화와 연마 공정에서 Wafer에 도포된 구리의 두께를 실시간으로 측정하여 정밀하게 제어할 필요가 있는데, 이때 획득되는 센서값을 실제 두께 값으로 환산하는 계산과정에서 오차가 발생할 수 있다. 실제 측정 값에 근사한 값을 얻도록 단순평균을 이용한 방법, 이동 평균, 필터 들을 사용하여 결과를 비교하여 옹고스트롬 단위의 두께를 실시간으로 측정하는 제어 시스템의 편차를 줄이도록 하는 방법의 구현에 대해 기술한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.3
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• pp.57-64
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• 2005

In two-degree of freedom(TDOF) inertial sensors, two axes are mechanically correlated with each other. Fault source of one axis sensor may affect the other axis sensor, and therefore multiple fault detection and isolation(FDI) technique is required. Conventional FDI techniques using hardware redundancy need four TDOF inertial sensors for FDI. In this study, three TDOF inertial sensor redudancy case is considered, where conventional FDI technique can detect the fault, but cannot isolate the fault sensor. Hybrid FDI technique is proposed to solve this problem. Hybrid FDI technique utilizes the analytic redundancy by utilizing the unscented kalman filter as well as hardware redundancy for FDI. To verify the effectiveness of the proposed FDI technique, numerical simulations are performed using six degree of freedom nonlinear aircrft dynamics.

• Resources Recycling
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• v.17 no.3
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• pp.21-28
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• 2008

Using the post-consumer waste and edge scrap mixed PET with small amount PP air filter elements of automobiles. It was studied that these mixed waste plastics of the various types of the PET were practicable for the material recycling. Various waste PET/PP plastics were collected, crushed, dried in vacuum, and extruded to recycled PET/PP chips. These chips were mixed with three kinds compatibilizers, EVA, MBS, and recycled PVB of the ratio of $3{\sim}10wt.%$ for the purpose of the compatibility for the post-consumer waste and edge scrap. We investigated mechanical and thermal properties of PET/PP mixtures which were compound with the weight ratio of compatibilizers. Compatibilizer, MBS application was showed the most excellent mechanical properties in the range of the $3{\sim}5wt.%$ EVA application was displayed good impact strength and thermal property in the range of $3{\sim}5wt.%$ Last, recycled PVB application was showed poor mechanical properties in the whole range ratio of the PVB.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.8
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• pp.1180-1187
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• 2022

As the likelihood of occurrence of the localized microbursts or severe flooding is increased due to the unusual weather changes, it is the very urgent problem to detect these weather hazards with a local weather radar. For a local weather radar of this purpose, it is essential to detect the low altitude and the fast varying weather conditions. Therefore, the very fast update of the weather information and the efficient clutter removal is very important. To achieve this goal, the appropriate method should be applied which does not need the mechanical elevation scanning and has the capability of the efficient clutter removal. Therefore, in this paper, the usefulness of the implementation of elevational filter banks with the spatial FFT algorithm was analyzed and investigated using a simple array antenna. It is shown that the suggested method can be used for both the minimization of the ground clutter and the fast update of weather information.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06c
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• pp.315-319
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• 2008

인터넷 환경은 놀랄만한 속도로 발전하고 있다. 사용자의 수가 늘어나고 그와 동시에 자료의 양도 폭발적으로 늘어나고 있음에 따라, 정확한 정보를 찾고 불필요한 정보를 필터링 하는 기술이 요구되기 시작하였다. 그 대표적인 기술이 시맨틱 웹(Semantic Web)[1] 으로 시맨틱 웹은 웹상의 정보에 메타데이터를 추가로 정의하여 사람 뿐 아니라 컴퓨터가 그 정보의 의미를 파악 할 수 있도록 하는 것이다. 이러한 시맨틱 웹을 위해서는 기계가 의미를 이해할 수 있도록 온톨로지(Ontology)를 먼저 구축해야만 한다. 온톨로지는 자원과 개념의 관계를 정의해 놓은 일종의 사전으로 이를 기술하기 위한 언어로는 RDF, OWL등이 있다. 온톨로지 데이터가 증가함에 따라 온톨로지 저장소의 크기가 증가하게 되면 성능을 위해 지역적으로 온톨로지 저장소를 분산해야 한다. 이에 따라 본고는 분산 환경에서의 통합된 질의에 대한 연구를 바탕으로 확장 가능하고 유연한 구조의 분산 온톨로지 모델을 제시한다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.189-192
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• 2005

공학시스템의 설계 문제는 시스템 구성이 복잡하고, 구조적으로 열려있으며, 전기, 기계, 유압, 열등의 서로 다른 에너지 도메인 구성 요소를 포함한다. 최적의 설계를 위해서는 각 도메인에 대한 통합된 설계 방법과 자동적이고 구조적으로 열린 공간에 대한 효율적인 탐색방법이 요구된다. 본 논문은 도메인에 독립적이며 모델링과 해석에 장점을 가진 본드 그래프 (bond graph)와 대규모 공간 해의 탐색에 접합한 진화 알고리즘의 일종인 유전자 프로그래밍(Genetic Programming)을 결합하여 멀티 도메인 동적시스템에 대한 디자인 해를 자동적으로 생성해주는 설계 방법을 제시하고, 제안된 설계방법의 효용성을 입증하기 위해서 이를 아나로그 필터 설계에 문제에 적용하였다.

• Journal of Hydrogen and New Energy
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• v.34 no.5
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• pp.497-504
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• 2023

This study analyzes pressure distribution and pressure drop in the receptacle used in charging system of hydrogen fuel cell vehicles. The objective is to minimize receptacle-induced pressure drop by redesigning internal flow channels. Through numerical simulations, three receptacle variants are compared with a baseline case. Results show reduced pressure drop in the filter section. However, the check valve section exhibits higher pressure drop, requiring further improvement. By increasing throat diameter, pressure drop is decreased by 28% between inlet and outlet of the receptacle. This study shows the relationship between dynamic pressure and pressure drop, providing a guideline for receptacle performance optimization. The redesigned receptacle offers potential for enhancing hydrogen charging efficiency.

• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.59-68
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• 2013

In the present study, sea water reverse osmosis desalination system was composed with an ultra-filtration membrane as a pre-treatment. Sea water was induced into the pre-treatment composed with an auto-screen filter and an ultra-filtration membrane. It was proved that the permeate of the pre-treatment was adequate for reverse osmosis desalination system by measuring the $SDI_{15}$ and the turbidity. Feed salinities was changed by mixing the brine and the permeate. Inlet salinities effected the performances of sea water reverse osmosis desalination system in a large amount such as the salt rejection, the recovery ratio, the pressure, the product salinity. Energy consumptions per the ton of the product were almost linearly increased with the inlet salinities.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.8
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• pp.44-49
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• 2003

In case of an extrinsic Fabry-Perot interferometric sensor, the phase compensating technique is particularly necessary in applying the interferometer to detecting acoustic emission signals because of signal-fading problems. The technique makes it possible to maintain the phase at the quadrature point. In this paper, we developed the stabilization control sensor system that is composed of a broadband light source, a tunable Fabry-Perot (F-P) filter and a control-circuit board. A tension test of a composite specimen was performed to verify if the developed system could compensate the phase change induced from the tension strain and keep the phase at the quadrature point.