• 대한기계학회논문집A
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• 제26권8호
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• pp.1506-1511
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• 2002

A computer aided expert system fur spur, helical, bevel and worm gears was newly developed by using AutoiCAD system and its AutoLISP computer language in the present study. Two methods are available for a designer to draw a gear. The first method needs the gear design parameters such as pressure, module, number of tooth, shaft angle, velocity, materials, etc. When the gear design parameters are inputted, a gear is drawn in AutoCAD system and maximum allowable power and shaft diameter are calculated additionally. The second method calculates all dimensions and gear design parameters to draw a gear when the information such as transmission, reduction ratio, nm, materials and pressure are inputted. The system includes four programs. Each program is composed of a data input module, a database module, a strength calculation module, a drawing module, a text module and a drawing edit module. In conclusion, the CAD system would be widely used in companies to find the geometric data and manufacturing course.

• 한국기계가공학회지
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• 제14권6호
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• pp.129-135
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• 2015

This paper shows significant methods that improve the lifespan of LED modules as well as efficiently using an aluminum heat-sink for LED module in high power. It proposes a method that raises stability and lifespan to protect LED modules and the power unit when the LED module has been used for a long hours at high temperatures. During the research, we applied a method of pulse-width modulation (PWM) in order to prevent the phenomenon that the entire power of a system is turned off and the lifespan is reduced when the LED nodule reacts to the high temperatures. To protect the LED module and SMPS based on high efficiency, a temperature sensor is attached underneath the circuit board and the sensor measures the temperature of circuit board when the LED module is powered on. The electrical power connected to SMPS is controlled by PWM when the temperature of the LED module reaches a particular temperature.

• 한국정보전자통신기술학회논문지
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• 제4권1호
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• pp.39-45
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• 2011

본 논문에서는 공통의 플랫폼을 기반으로 하는 모바일 와이맥스 기지국 운용용 휴대형 신호분석 시스템의 설계방법을 제안하고, 이를 하드웨어 모듈로 구현하였다. 새롭게 제안한 신호분석 방법은 RF 신호의 IF 신호로의 하향 변환 및 이득제어를 수행하는 광대역 RF 모듈과 계측 기능을 수행하는 DSP 기반 디지털 신호분석 모듈로 구현하는 것이다. 타 고정 대형 시스템과의 비교를 통해 수행한 신호분석 알고리즘의 성능을 검증한 결과, 분해능의 차이는 없음을 확인하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.624-629
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• 2001

An experimental study was performed to investigate adiabatic wall temperature and heat transfer coefficient around on a module with longitudinal fin heat sink cooled by forced air flow. In the first method, inlet air flow(1-7m/s) and input power(3-5W) was varied after a heated module were placed on an adiabatic floor($320{\times}550{\times}1mm^{3}$). An adiabatic wall temperature was determinated to use liquid crystal film(LCF). In the second method to determinate heat transfer coefficient, inlet air flow(1-7m/s) and the heat flux of rubber heater($0.031-0.062\;W/cm^{2}$) was varied after an adiabatic module was placed on rubber heater covering up an adiabatic floor. In addition, surface oil-film visualization were performed to characterize the macroscopic flow-field around a module.

• 전력전자학회논문지
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• 제25권4호
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• pp.311-318
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• 2020

A photovoltaic (PV) system uses an AC module integrated converter (MIC) to operate PV cells at a maximum power point (MPP) and for high efficiency. The MPP of a PV cell varies depending on partial shading conditions, and loss occurs differently according to the configuration method of the PV-MIC. Therefore, this study compares the losses of passive components and power semiconductors according to the partial shading conditions of the PV module. Theoretical loss analysis is performed using parameters for the datasheet and PSIM simulation results. Analysis results verify that the one-stage PV-MIC demonstrates high efficiency.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2490-2495
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• 2005

The scheduling of plant should be determined based on the product demands correctly forecasted by reasonable methods. However, because most existing forecasting packages need user's knowledge about forecasting, it has been hard for plant engineers without forecasting knowledge to apply forecasted demands to scheduling. Therefore, a forecasting module has been developed for plant engineers without forecasting knowledge. In this study, for the development of the forecasting module, an automatic method using the ARIMA model that is framed from the modified Box-Jenkins process is proposed. And a new method for safety inventory determination is proposed to reduce the penalty cost by forecasting errors. Finally, using the two proposed methods, the web-based automatic module has been developed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.987-993
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• 2003

The module UPS can flexibly implement expansion of power system capacities. Furthermore, it can be used to build up the parallel redundant system to improve the reliability of power system operation. To realize the module UPS, load sharing without interconnection among parallel connecting modules as well as a small scale and lightweight topology is necessary. In this paper, the three-arm converter/inverter is compared with the general full-bridge and half-bridge topology from a practical point of view and chosen as the module UPS topology. The switching control approaches based on a pulse width modulation of the converter and inverter of the system are presented independently The frequency and voltage droop method is applied to parallel operation control to achieve load sharing. Two prototype 3kVA modules are designed and implemented to confirm the effectiveness of the proposed approaches. Experimental results show that the three-arm UPS system has a high power factor, a low distortion of output voltage and input current, and good load sharing characteristic.

• 한국태양에너지학회 논문집
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• 제22권2호
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• pp.1-10
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• 2002

This study is a study on the building integrated method of Photovoltaic. It was analyzed into a basic installation condition and an integrated form in this study. And it was confirmed through the 3D simulation & drawing work of an integrated situation to the real domestic building. The Photovoltaic installation of the country to an optimal efficiency for the year must be installed to the due south with an angle of thirty degrees. And also a module spacing must be more than doubled from the bottom to the top of module to prevent from efficiency falling by a shadow of photovoltaic module in a roof setting of flat roof. If Photovoltaic module is an adequate material that is a basic requirement as a building's finishing material, it's not only an efficiency of alternation with an existing finishing material but also a building's design element.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.643-648
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• 2005

Headlight monitoring is one of the new requirement in the modern Metro EMU design. In order to meet this requirement. several kinds methods are already provided in the train. This paper introduces another method. which is designed with the darlington circuit and can switch off/on the headlight with the circuit. Following the conceptual method. the monitoring module was developed and installed in domestic line. Investigation of the concept shall be focused on the more smaller module and expending the module to other part.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.250-253
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• 1998

This paper presents a multi-modal neural network composed of a preprocessing module and a multi-layer neural network module in order to enhance the nonlinear characteristics of neural network. The former module is based on spectral method using Chebyschev polynomials and transforms input data into spectra. The latter module identifies the system using the spectra generated by the preprocessing module. The omnibus numerical experiments show that the method is applicable to many a nonlinear dynamic system in the real world, and that preprocessing using Chebyschev polynomials reduces the number of neurons required for the multi-layer neural network.