• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.10
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• pp.20-37
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• 1996

A current-controlled OTA-R schemitt trigger circuit is described. It consists of two OTA's and two resistors. The output level of the circuit is determined by one OTA and one resistor, and the threshold level by the other OtA and resistor. The theory of operation is presented and computer simulation results and experimental results using CMOS arrays are used to verify theoretical predictions. The results show close agreement between predicted behaviour and experimental performance.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2416-2418
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• 2000

The new-type measuring modules for unmanned remote supervisory system using mobile communication network have been designed in this study. Measuring modules consist of temperature measuring module, humidity measuring module and human body sensing module. And we will design a main part to collect and process informations of each modules, evaluate reliability of combined total system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.1
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• pp.92-96
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• 2005

This paper deals with a batch processor model in which the batch processing times depend on the jobs assigned to the batch. Each job has a distinct processing time which is determined as not the exact value but the range from the lower limit to the upper, which makes it possible to group several jobs into the same batch. In point of this flexibility our model can be referred to as the generalization of the bum-in model in which the upper limit of each job is unbounded. The jobs to be scheduled may be available nonsimultaneously. Therefore they have different ready times. We develop the model to describe the problem situation and the heuristic methods to minimize the total tardiness. And our batching rule is compared with other dispatching ones.

• Spatial Information Research
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• v.10 no.4
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• pp.515-532
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• 2002

Planning Support System (PSS), an alternative framework of computer-aided planning system combining geographic information system (GIS), urban models, and visualization tools, has been actively researched and applied in many developed countries. This paper introduces a PSS-based land use change model, What if\ulcorner PSS, by applying it to Chongju City, Korea. This model application study used the spatial database, Restricted Development Zone (RDZ), and other hypothetical land supply- and demand-related policies of Chongju City. The collaborative PSS model supported land use planning process by helping users to speedily and easily create and test policy-oriented scenarios. The study found that the fully operational PSS model was readily applicable and useful to Korean local land use planning. The paper discusses the conceptual model framework, data requirement, application process, model output, and practical usage. This study would be considered as a prototypical approach of PSS-based land use plan making for Korean cities.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2209-2211
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• 2001

Unmanned remote supervisory system consists of data processing unit and measuring systems-temperature measuring module, humidity measuring module and human body sensing module. The data processing unit to collect and process informations of each measuring modules has functions of data communication between a mobile cellular-telephone and measuring systems.

• Journal of the Korean Institute of Rural Architecture
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• v.2 no.3
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• pp.65-76
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• 2000

This study aims to clarify the characteristics of townhouse corresponding to the changing life style for the future, and suited to the small and medium urban areas of Korea(focused on Chongju area) from its traditionality and regionality's point of view. The results of this study are as follows; 1. The traditional design elements of Chongju area : 1) A court; a court of inner building - light, wind. 2) A balcony; intermediate space, cornice. 3) Eave line; a horizontal line for approach. 2. The regional design elements of Chongju area : 1) Maintenance of skyline which had the same building height as strip of road. 2) The formal spatial design elements to think about natural view. 3) Simple appearance and delicate detail.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.368-371
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• 2001

In this paper, the experiment and simulation results of the Boost converter for PFC(power factor correction) using metal powder inductor are presented. The metal powder inductor used in the experiment was composed of Ni-Fe-Mo, Ni-Fe, Fe-Si-Al compound respectively The performance of the 500w class PFC rectifier with the average current mode control and the 300W class PFC rectifier with the variable frequency control, are evaluated.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3253-3255
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• 1999

출생시 국내에서 영아 사망률은 약 1%에 이르고 태아의 질병발생과 사망은 계속적으로 일어나고 있으므로 저가의 태아감시기술의 개발이 절실하다. 이를 위하여 본 연구는 임산부의 복부로부터 태아의 움직임과 심음을 검출하는 증폭기의 개발을 목표로 한다. 검출된 신호는 듣거나 녹음할 수 있으며. A/D 변환할 경우 PC에서 태아의 심음을 분석할 수 있게 한다. 개발된 증폭기를 이용하여 잡음에 노출된 일반 대학병원 환경에서 30명의 임산부를 대상으로 임상실험을 수행한 결과, 저잡음 특성을 나타내고. 빠른 경우 22주에서도 태아의 심음을 검출할 수 있었고. 심음의 주기검출이 가능하였다.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1193-1195
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• 2003

In this paper, to analyze efficiency characteristic, one of important factors in design of DC-DC converter prototype, theoretically derived power loss of individual components generating in DC-DC converter and compared theoretical results with experimental results. For evaluation of results, active clamp type Forward DC-DC converter with synchronous rectifier was composed of experimental converter. Efficiency result measured in experimental converter was compared with theoretical efficiency result derived in this paper. In comparative result, a fact that derived theoretical value and experimental value comparatively correspond have been able to verify.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1196-1198
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• 2003

In this Paper, a PC-based virtual measuring program for efficiency measurement of DC-DC converter is developed. Furthermore, a newly developed highly accurate and reliable data acquisition system for DC-DC converter is presented. The virtual measuring system consists of two different types of monitoring and measuring system. Also, this paper give a full explanation for a LabVIEW realization of the measuring system for DC-DC converter.