• 한국생산제조학회지
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• 제20권4호
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• pp.376-381
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• 2011

CVT(Continuously Variable Transmission) is one of the most promising candidates for the future automobile transmission because of its continuously variable gear ratio and reduced shift shock. It is also possible to operate the power source at its high efficiency region with CVT. The CVT system consists of thrust plate, driving pulley, belt, driven pulley, and preload spring of output shaft. In this paper, the dynamic modeling of a CVT system is completed to obtain the static performances of CVT system. A simulator is implemented on Matlab(Simulink), which can analyse the static performances of a CVT system. The methods for improving the total efficiency of a motorcycle system are also proposed based on the simulation results. In this study we increase the capacity factor of CVT up to the three times of default specification.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.175-177
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• 2007

This paper presents for the torque characteristics and improving the efficiency of driving system of electric bicycle which applied IEWPM(Independently Excited Winding Permanent Magnet) motor. IEWPM motor can expand the number of phase from 3 phases to multiphase like SRM motor because stator windings are unconnected directly. BLDC motor raise rotor'-s electromagnetic torque per unit volume by using Spoke type permanent magnet. By using two photo sensor per phase and applying excited width, advance angle and bipolar control, we confirmed higher torque at a low speed, higher out-put at a high speed, and efficiency improvement at a wide speed control area.

• 로봇학회논문지
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• 제15권1호
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• pp.32-38
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• 2020

This paper describes a method for tracking attitude and position of underwater robots. Underwater work with underwater robots is subject to differences in work efficiency depending on the skill of the operator and the utilization of additional sensors. Therefore, this study developed an underwater robot that can operate autonomously and maintain a certain attitude when working underwater to reduce difference of work efficiency. The developed underwater robot uses 8 thrusters to control 6 degrees of freedom motion, IMU (Inertial Measurement Unit), DVL (Doppler Velocity Log) and PS (Pressure Sensor) to measure attitude and position. In addition, the thruster allocation algorithm was designed to follow the control desired value using 8 thrusters, and the motion control experiments were performed in the engineering water basin using the thruster allocation method.

• 한국멀티미디어학회논문지
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• 제10권6호
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• pp.699-706
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• 2007

This article is an approach to improving the clustering of Web images by using high-level semantic features from text information relevant to Web images as well as low-level visual features of image itself. These high-level text features can be obtained from image URLs and file names, page titles, hyperlinks, and surrounding text. As a clustering algorithm, a self-organizing map (SOM) proposed by Kohonen is used. To evaluate the clustering efficiencies of SOMs, we propose a simple but effective measure indicating the accumulativeness of same class images and the perplexities of class distributions. Our approach is to advance the existing measures through defining and using new measures accumulativeness on the most superior clustering node and concentricity to evaluate clustering efficiencies of SOMs. The experimental results show that the high-level text features are more useful in SOM-based Web image clustering.

• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.789-793
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• 2003

This study focused on the optimization of the illumination method for efficient use of light energies in a photobioreactor. In order to investigate the effect of radiator position, a model simulation study was carried out using Synechococcus sp. PCC 6301 and an internally radiating photobioreactor as a model system. The efficiency of light transfer in a photobioreactor was analyzed by estimating the average light intensity in a photobioreactor. The simulation result, indicate that there exists an optimal position of internal radiators, and that the optimal position varies with radiator number and cell concentration. When light radiators are placed at the optimal position, the average light intensity is about 30% higher than that obtained by placing radiators at the circumstance or center of a photobioreactor. The method presented in this work may be useful for improving light transfer efficiency in a photobioreactor.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1531-1533
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• 2007

We made a high-efficiency lamp with same spec. as a normal lamp by improving physical constants of a lamp and then analyzed varied effects. By applying novel physical constants to an EEFL, we acquired decrease of lamp operating power and voltage.

• 시큐리티연구
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• 제8호
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• pp.197-218
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• 2004

This study has been conducted to provide data that contribute to increasing efficiency of 'Private Security', which is cooperated by customer, security companies and the police which carried out 'Public Law Enforcement' and controls security companies. To reach this purpose, we investigated the status of the 'Security Alarm Systems' operated by security service companied in Korea, analyzed arising problems, considered the polices for improving the operational quality. 'Electronic Security Systems' will increase working efficiency in performing 'Private Security'. There can be no two opinions on this matter. Therefore, it can be supposed that the improvement of operational quality of 'Electronic Security System' is an important factor to accomplish security services. 'Security Alarm System' is one of the 'Electronic Security System'. The critical problems in operating 'Security Alarm system' are unnecessary response by false alarm and nuisance alarm. To reduce the problems, it is suggested that security specialist officially licensed should improve security planning, installation and maintenance, and the 'Alarm Verification System' should be introduced with appropriate facilities.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.304-305
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• 2014

New and Renewable eco-friendly energy technique can be to enable rational use of resources, as well as securing economic efficiency. Therefore, most of the public facilities must apply eco-friendly energy systems. In this study was applied the solar light energy system to the construction projects. As a result, the proposed system was implemented various effect such as the power cost savings in public facilities. In addition to, the proposed system was improved functional aspects such as improving space utilization.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.129-130
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• 2011

2009 Presidential Council on National Competitiveness to plan trying to the advancement in the construction industry 'design and engineering of the global competitiveness' in the content of weak points of the design and engineering capabilities to secure the overall problem. In domestic technological of design and engineering behind the other building construction sector about 70%. Especially hindrance factor was founded between design ordering organization, design firm and subcontractor in working design stage. In this paper carried out to hindrance factor that decrease the efficiency in working design stage for a strategy to improve the utilization of basic data.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1786-1788
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• 2001

A standard source was constructed, and then simulated its light distribution characteristics of the basic arrangements by shape, by angle, and by displacement. And it was constructed a light collecting holder of optical fiber lighting systems using RGB LED. As a result, we obtained the improving light collecting efficiency was improved 6.5 times with compared to existing systems.