• 한국정밀공학회지
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• 제22권11호
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• pp.72-81
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• 2005

A new spherical-type 3-degree-of-freedom parallel mechanism consisting of a two degree-of-freedom parallel module and a serial module is proposed. Two alternative designs for the serial sub-chain are suggested and compared. The first design employs RU joint arrangement for the serial sub chain structure. The second design incorporates a gear chain to drive the distal revolute joint of the serial sub-chain from the base platform of the mechanism. This modification significantly improves kinematic characteristics of the mechanism within its workspace. Firstly, the closed-form solutions of both the forward and the reverse position analysis are derived. Secondly, the first-order kinematic model with respect to three inputs which are located at the base is derived. Thirdly, it is confirmed through simulation that the modified mechanism has much more improved isotropic characteristic throughout the workspace of the mechanism. Lastly, the proposed mechanism is implemented to verify the results from this analysis.

• 한국주거학회논문집
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• 제23권4호
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• pp.41-48
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• 2012

The purpose of the study, approaching from the aspect of the construction technologies, is to determine the architectural techniques of traditional wood architects in existence, through which the systems and techniques that create the inherent characteristics of Korean Architecture are clarified. With understanding traditional construction system and focusing on the fact that built environment results from the consistent standards and technologies of architects, this study inquires into the systematic standard and its formation that present in the process of planning for the overall scale and shape of a building from the following (four) perspectives. The study determines the characteristics of '間(Kan)' (unit; fundamental unit that measures Korean traditional houses) and the methods of columns disposition of which the '間 (Kan)' is made up. Once the necessary spaces are decided according to the size of a building, then floor plans are drawn with the standard unit, '間(Kan)'. The '間(Kan)', as a modular unit, is not only composing the floor plans, but also functioning as an Area unit, Space unit and Structural unit. Composition of '間(Kan)' varies with disposition of columns, and therefore multiform of floor and spaces are created. In this study, the '間(Kan)', as a standard unit, is used in the form of specific size and area, and it is demonstrated how the floor plans are developed by organizing the columns in accordance with the spaces requested.

• 설비공학논문집
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• 제25권9호
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• pp.477-483
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• 2013

A numerical analysis of solid-liquid phase change was performed on a heat transfer module which consisted of circulating water path (BRINE), heat transfer plate (HTP) and phase change material (PCM) layers, such as high temperature PCM (HPCM, $78{\sim}79^{\circ}C$) and low temperature PCM (LPCM, $28{\sim}29^{\circ}C$). There were five arrangements, consisting of BRINE, HTP, LPCM and HPCM layers in the heat transfer module. The time and heat transfer rate for melting/solidification was compared to their arrangements, against each other. As results, the numerical time without convection was longer than the experimental one for melting/solidification. Moreover, the melting/solidification with the BRINE I-LPCM-BRINE II-HPCM arrangement was faster(10 hours) than the others; HPCM-BRINE-LPCM, BRINE I-HPCM-LPCM-BRINE II one.

• 대한기계학회논문집B
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• 제39권7호
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• pp.625-631
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• 2015

이번 연구는 패킹 모듈로 채워진 축열조의 방열 성능을 수치해석 하였다. 해석에는 PCM의 상변화 현상을 계산하기 위해 엔탈피-공극률 방법을 이용하였다. 이 방법을 통해서 방열 시 축열조 상부로부터 열전달유체가 흐를 때 모듈에서의 녹는 현상을 계산하였다. 축열조 디자인에 모듈 배치, 모듈 수 등의 다양한 인자가 있지만, 본 해석에서는 유량의 변화에 따라 나타나는 축열조 출구온도, 전체 PCM의 시간에 따른 녹은 양 및 축열밀도를 확인하였다. 결과적으로 유량이 증가할수록 출구온도가 높게 형성되었으며, 전체 PCM이 녹는데 필요한 시간이 짧아지고 축열 밀도 역시 증가하여 목표치의 93% 수준에 도달하는 것으로 나타났다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.243-246
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• 1996

Modular robot manipulator is a robotic system assembled from discrete joints and links into one of many possible manipulator configurations. This paper describes the design method of newly developed modular robot manipulator and the methodology of a task based reconfiguration of it. New locking mechanism is proposed and it provides quick coupling and decoupling. A parallel connection method is devised and it makes modular robot manipulator working well and the number of components on each module reduced. To automatically determine a sufficient or optimal arrangement of the modules for a given task, we also devise an algorithm that automatically generates forward and inverse manipulator kinematics, and we propose an algorithm which maps task specifications to the optimized manipulator configurations. Efficient genetic algorithms are generated and used to search for a optimal manipulator from task specifications. A few of design examples are shown.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.153-156
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• 2006

The vibration isolation system is a system that attenuates the vibration transmitted from surroundings by using external energy supply like electricity and feedback and/or feedforward functions. Such a system needs stiff structure to make precise positioning without ripple within a certain bandwidth. So, a horizontal and rotary arrangement of the actuation module is suggested by using lever linkage. Modeling and kinematic formulation are completed and system identification is accomplished to tune the design variables accurately. The vibration isolation control is performed by mu-synthesis with the uncertainties in design variables. Low frequency signal enhancement circuit and saturation proof integration algorithm are devised to use seismic sensors for displacement control. This overall system shows good disturbance rejection performance.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.68-70
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• 2005

The arrangement technique of solar cell and module is accomplished quickly with development of power semiconduc-tors. It reached to a practical cost linearly. Photovoltaic power system increases constantly. There are 3kWtracking photovoltaic system and fixed photovoltaic system in Chosun University. This paper compares operating characteristics of the fixed photovoltaic system and the tracking photovoltaic system with shows the efficiency.

• 센서학회지
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• 제20권2호
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• pp.77-81
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• 2011

This paper presents a single-pole eight-throw(SP8T) switch based on proposed a radio-frequency(RF) microelectromechanical systems (MEMS) switches. The proposed switch was driven by a double stop(DS) comb drive, with a lateral resistive contact. Additionally, the proposed switch was designed to have tapered signal line and bi-directionally actuated. A forward actuation connects between signal lines and contact part, and the output becomes on-state. A reverse actuation connects between ground lines and contact part, and the output becomes off-state. The SP8T switch of 3-stage tree topology was developed based on an arrangement of the proposed RF MEMS switches. The developed SP8T switch had an actuation voltage of 12 V, an insertion loss of 1.3 dB, a return loss of 15.1 dB, and an isolation of 31.4 dB at 6 GHz.

• 한국수소및신에너지학회논문집
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• 제34권2호
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• pp.132-140
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• 2023

In this study, rotary magnet holder (RMH) was manufactured to analyze the ion transport effect according to the rotating magnetic field for the hydrogen production efficiency by alkaline water electrolyte. In the experiment, the voltage signal according to the magnet arrangement inside the RMH, the rotation speed, and the rotation time was measured using the voltage measurement module. As a result of the voltage signal measurement experiment, the average potential difference increased as the rotation speed of the RMH increased. Through the results of the voltage signal measurement experiment, the most efficient magnet arrangement (case 2) was applied to the RMH to conduct a water electrolysis experiment. A 20% NaOH aqueous solution was filled in the electrolytic cell, and a direct current 2 V constant voltage was applied to measure the current value according to the RMH rotation to compare the hydrogen generation amount. When rotating at 100 RPM, the hydrogen production efficiency increased by 8.06% compared to when not rotating. Considering the area exceeding +25 mA, which was not measured at the beginning of the experiment, an increase in hydrogen production of about 10% or more can be expected.

• 한국항행학회논문지
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• 제20권1호
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• pp.86-92
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• 2016

최근 사람이 다수 붐비는 지역에 스마트 폰이나, 태블릿 등을 바로 충전할 수 있는 태양광 모듈이 설치되어 서비스를 제공하고 있다. 하지만 설치비용이 높아 이용인원이 적은 지역에 설치 할 경우 비용측면에서 부담이 되며, 협소한 지역에는 설치가 어려운 문제점이 존재한다. 본 논문에서는 이와 같은 문제를 해결하기 위해 국가에서 제공하는 데이터와, 실제 환경에서 수집한 데이터를 이용하여 각 지역에 해당 서비스를 제공받는 사람에 대한 정보를 분석 한 후 대기시간 및 태양광 충전시간을 고려하여 환경에 맞는 최적의 전력을 수집 및 제공하는 시스템을 제안하였다. 실험결과 수집전력이 충전전력량보다 상회하여 충전이 지연되지 않았으며, 약 95분경에 스마트 폰의 전력을 모두 충전할 수 있음을 확인하였으며, 버스 대기시간인 10분에서 20분 사이에 스마트 폰이 한 대일 경우 약 50%가량을 충전할 수 있으며, 여러 대일 경우 약 20%가량을 충전할 수 있음을 확인하였다.