• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.432-433
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• 2010

본 논문에서는 직렬형 디젤 하이브리드 전기 트럭 구동을 위한 견인 전동기 제어 시스템 개발에 대해 소개한다. 높은 출력 밀도를 요구하는 복합형 전기 차량의 특성을 고려하여 매입형 영구자석 동기전동기를 선정하고, 대전류 고효율 시스템 구성을 위해 수랭식 MCU(Motor Control Unit)를 개발 하였다. 또한 빠른 토크 응답 특성과 넓은 영역의 속도 운전을 위한 약자속 제어 기법을 적용하였으며, 전체 시스템 효율을 향상시키기 위해 단위 전류당 최대 토크 제어 기법(MTPA)이 사용 되었다. 개발 된 제어 시스템 및 제어 기법을 실험을 통해 검증 하였다.

• Management Science and Financial Engineering
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• v.20 no.2
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• pp.33-37
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• 2014

A flow shop scheduling problem involves scheduling jobs on multiple machines in series in order to optimize a given criterion. The flow time of a job is the amount of time the job spent before its completion and the stretch of the job is the ratio of its flow time to its processing time. In this paper, a hybrid genetic algorithm (HGA) approach is proposed for minimizing the total stretch in flow shop scheduling. HGA adopts the idea of seed selection and development in order to reduce the chance of premature convergence that may cause the loss of search power. The performance of HGA is compared with that of genetic algorithms (GAs).

• KIEAE Journal
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• v.4 no.2
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• pp.11-18
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• 2004

Growing use of entire glass facades with metal frames are popularly witnessed in modern building practices and design competition as well. In spite of architectural aesthetics and view to outdoors, environmental issues still exist in that kind of buildings. One of the solutions for the problems might be the use of functional glasses such as a heat-resistant glass or various tinted glasses for the glass walls. This paper aims to provide performance data related to the impact of various transmittal materials of window systems on the light distribution. A series of computer simulation deals with the basic geometrical and optical design elements of a commonly used all-glass facades. Additionally an experimental configuration of the vertical window is proposed for better result of daylighting. A window system equipped with an inner-light shelf can improve the uniformity of natural light in a space by reducing the level of illumination near the window and redirecting light deeply into the space.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.768-769
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• 2017

본 연구에서는 시계열예측 신경망기법에서 특징 선별기법을 적용하여 학습의 효율을 높이고 성능을 개선하는 방법론을 고찰한다. 순환구조 신경망을 사용하여 시계열 예측기를 구현하였으며, 효과적인 특징을 선별하기 위하여 FMM 신경망을 사용하여 특징의 연관도 요소를 산출하는 방법을 제시하였다. 모바일 결제시스템에서 실제 측정된 데이터를 사용하여 사용빈도 예측실험을 수행하였으며 그 결과를 통하여 제안된 기법의 유용성을 고찰하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.1
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• pp.87-92
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• 2002

We present a simple experimental method for determination of limiting intrinsic fixed-pattern non-uniformity (NU) due to fabrication process in two-dimensional CCD multiplexers (MUXs) that are used for hybrid focal plane arrays. Here, this is done by determining separately the two NUs viz. that are $V_T$ dependent and $V_T$ independent. From these measurements, process dependent NU can be extracted. It is argued that $V_T$ dependent NU can be eliminated by designing novel input circuits whereas $V_T$ independent NU, primarily, dependent on process control and material variations may be reduced but cannot be eliminated completely and hence limits the FPA performance eventually.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.4
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• pp.402-411
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• 2000

The dental profession is currently experiencing a technology explosion. Processes are being replaced by modern, inexpensive, and precise techniques that can be used to solve complex restorative problems. Electrical discharge machining(EDM, known as spark erosion in Europe) is a nonconventional, industrial technique that has application in dentistry. EDM may be defined as a metal removal process using a series of sparks to erode material from a workpiece in a liquid medium under carefully controlled conditions. EDM is recently adopted in the dental laboratory to fabricate precision attachments, hybrid tele-scope crowns, Ti-ceramic crowns. EDM has also been used to achieve a passive precision metal-to-metal fit between the substructure bar and the removable superstructure and to correct the fit of implant retained restorations. In this article, a brief history and explanation of EDM is discussed and a description of the use of this process for fabricating attachments and crowns or for correcting the fit of cast restorations is presented.

• Journal of Plant Biology
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• v.12 no.1
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• pp.35-48
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• 1969

This study was made on the taxa Chrysanthemum zawadskii complex that grow in South Korea on the basis of chromosomes, epidermis, pollens and gross morphology. I have found four types of chromosome numbers, 36, 45, 54, and 72 as a polyploidal series. Even though the gross morphology was quite similar almost the same gross morphology, chromosome number was different among the taxa. The taxa of 36 chromosomes present broad and fine lobed leaves which grow separately, broad leafed taxon in the mainland of Korea and the other's in Ullungdo Island which is isolated form the mainland in the East Sea. The taxa of 54 chromosomes are also present in the broad and in the fine lobed leaves. The fine lobed leave taxon grows in central to northern Korea and in the high altitude of mountains. Broad leafed taxon grows in central to southern Korea and comparatively lower altitude of the mountains. The taxon of 72 chromosomes is grown in the high altitude of Mt. Hallasan which is isolated from the mainland of Korea. According to this study of Chrysanthemum zawadskii complex, I have arranged the scientific names, as Chrysanthemum zawadskii subsp. latilobum, subsp. acutilobum, subsp. naktongenese, subsp. lucidum, subsp. coreanum and hybrid between subsp. acutilobum X subsp. latilobum.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.130-135
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• 2009

This study investigates the need of calibrating a nodal network ventilation simulation model (CONTAMW 2.4). For this purpose, the series of ventilation experiments were conducted and then compared to simulation outputs from an uncalibrated simulation model, resulting in a significant difference between two. Hence, an optimization routine was employed to estimate unknown parameters in the simulation model. In the paper, the authors presents 1.3 unknown parameters with the validated simulation model. It was found that the model with estimated unknown parameters predicts the ventilation phenomena accurately.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.10a
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• pp.117-122
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• 1998

A servo system requires faster and more accurate dynamic reponses. Generally a PD control is mainly used to obtain the precision, and in the other hand a fuzzy control to improve the transient response and to cope with the nonlinearity of systems. Recently hybrid control, which is attempted to combine the advantages of PD control and a Fuzzy control was proposed, but this technique requires complicate design procedures. Therefore in this paper, designed on the Fuzzy controller with a various series rules, width of membership functions. And also it was showed to have the excellent adaptive performances against disturbances and the usefulness of this controller from the results of simulations.

• International Journal of High-Rise Buildings
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• v.8 no.3
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• pp.221-227
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• 2019

In this paper passive seismic retrofit devices for building structures developed by the author in recent years are introduced. The proposed damping devices were developed by slightly modifying the configuration of conventional devices and enhancing their effectiveness. First a seismic retrofit system consisting of a pin-jointed steel frame and rotational friction dampers installed at each corner of the steel frame was developed. Then two types of steel slit dampers were developed; box-type slit damper and multi-slit damper. In addition, hybrid dampers were developed by combining a slit damper and a friction damper connected in parallel. Finally a self-centering system was developed by using preloaded tendons and viscous dampers connected in series. For each retrofit system developed, an appropriate analytical model was developed, and the seismic performance was verified by loading test and earthquake analysis of case study structures. The experimental and analysis results show that the proposed systems can be used efficiently to enhance the seismic performance of building structures.