• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.574-579
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• 2011

In this study, we suggested a design modification method to reduce the vibration of an air conditioner for railway vehicles and increase the durability of its pipe lines. Through experimental vibrational mode analyses and structural modifications on the air conditioning system, vibration reduction scheme was suggested and evaluated its effectiveness by empirical modal analysis. The derived design idea was applied to a real air conditioning system and the expected improvement was obtained.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1561-1564
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• 1997

In the study, simulation result was studied by connecting PID controller in series to the established Neural Networks Controller. Neural Network model is composed of two layers to evaluate tracking performance improvement. The reqular dynamic characteristics was also studied for the expected error to be minimized by using Widrow-Hoff delta rule. As a result of the study, We identified that tracking performance inprovement was developed more in case of connecting PID than Neural Network Contoller and that tracking plant parameter in 251 sample was approached rapidly case of time variable.

• 한국경영과학회지
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• 제6권2호
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• pp.7-11
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• 1981

An inspection-maintenance policy is investigated for a system having various states. A policy is characterized by the type of maintenance and the next inspection time. Maintenance actions are classified into various types according to the depth of maintenance. Policy evaluation criterion is the expected cost accumulated up to the failure of the system. The problem is formulated as a Markov decision process and an optimal policy is found by using a policy improvement procedure. A numerical example illustrates the policy for a system having five states.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1993년도 추계학술발표회논문집
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• pp.51-54
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• 1993

In this paper, it is proposed the the SCADA(Supervisory control and Data Acquisition) system in Apartment complex. The proposed SCADA system make use of the computer CRT(Cathod RAy Tube), which automatically observe the Electrical Facility, Elvator Facility, Fire Alarm Facility and process in the real-time data. In order to improve the hardware performance and the information process, the SCADA system composed of master-slave topology and decentralized the supervisory Facility. This system is expected the retrenchment of construction expenditure and the level-up of supervisory execution.

• 환경위생공학
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• 제16권3호
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• pp.54-60
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• 2001

The need and concern about ecosystem are growing rapidly. However, ecosystem management systems are still in the first stage since the data are handled locally and separately. It results in the waste of money and time. In this research, we designed and implemented ecosystem management system of stream region using geographical information system(GIS) that is able to be used to manage the natural resource efficiently. It is expected to be used as a useful tool for Improvement of environment and management of ecosystem as well as recovery of natural environment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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• pp.94-96
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• 1993

At an operating point of the induction motor, there are many sets of stator frequency and voltage. This paper presents an algorithm to determine the stator frequency and voltage which maximizes the power factor without any informations of motor parameters. Improvement of efficiency us also expected due to high-power-factor operation.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.283-284
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• 2008

A cross-layer optimization is becoming a popular design methodology for the IP based next generation wireless network. We begin by investigating a cross-layer optimization scheme to enhance the system performance in wireless networks. By applying cross-layer optimization methodology to WiBro distributed network, the WiBro systems are expected to gain significant performance improvement and resource utilization enhanced. For further study we highlight some open challenges and new opportunities for cross-layer design.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.253-256
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• 2002

In Currently, OTFTS are actively studied around the world because they are expected to create new novel applications, which can not be implemented by the conventional Si semiconductor, due to the unique characteristics of organic materials. In this paper, the hole field effect mobility has been improved to the level of a-Si TFTs with 0.3cm2/V.sec, simply applying the surface treatment process on the gate with organic molecules. In addition, the model has been suggested and the temperature dependence of hole mobility analyzed.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1997년도 춘계학술발표회 논문집
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• pp.328-332
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• 1997

Hot stretching focused on the improvement of properties of poly(L-lactic acid) fiber. Some aliphatic polyesters are biodegradable under microbial attack and the new unique applications are expected. Generally, these materials have a somewhat low melting temperature and low mechanical properties compared with the aromatic polyesters. In this study, melt-spinning of poly(L-lactic acid) was conducted. We investigated effects of the stretching and the molecular orientation of aliphatic polyester fibers on the change of fine-structure. Glass transition temperature, molecular orientation and crystallinity increased according to the increase of stretching ratio.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
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• pp.417-420
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• 2000

The purpose of this paper is to design the menu of mobile phone based on the impression engineering. Free response survey analysis was used to collect impression data on mobile phone functions with time interval. Simultaneity analysis was applied to finding the relationship among selected impression. We cluster the related impression so as to design the menu of a mobile phone accordingly. This research is expected to contribute to the improvement of customer satisfaction by reflecting customer's impression in the process of product design.