• 한국자동차공학회논문집
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• 제20권4호
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• pp.46-51
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• 2012

Injection pressure, an important factor in filling process, should be minimized to enhance injection molding quality. Injection pressure can be controlled by valve gate open timing. In this work, we decided the valve gate open timing to minimize the injection pressure. To solve this design problem, we integrated MAPS-3D (Mold Analysis and Plastic Solution-3Dimension), a commercial injection molding CAE tool, to PIAnO (Process Integration, Automation and Optimization), a commercial PIDO (Process Integration, and Design Optimization) tool using the file parsing method. In order to reduce computational cost, we performed an approximate optimization using meta-models that replaced expensive computer simulations. At first, we carried out DOE (Design of Experiments) using OLHD (Optimal Latin Hypercube Design) available in PIAnO. Then, we built Kriging models using the simulation results at the sampling points. Finally, we used micro GA (Genetic Algorithm) available in PIAnO. Using the proposed design approach, the injection pressure has been reduced by 13.7% compared to the initial one. This design result clearly shows the validity of the proposed design approach.

• 한국정보통신학회논문지
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• 제25권6호
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• pp.834-840
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• 2021

먹는 물을 생산하여 공급하는 상수도 관로에 있어서 압력계에 대한 설치와 관리 방안이 미비함에 따라 압력데이터 신뢰성의 확보 및 운영관리의 어려움을 겪고 있는 실정이다. 관망 및 펌프 등 운영관리 효율화 및 SWM(Smart Water Management)을 구현하기 위해서는 하부 계측 센서의 정확한 데이터 취득을 통하여 의사결정이 이루어져야 한다. 따라서, 본 연구에서는 게이트 밸브와 버터플라이 밸브를 중심으로 관로의 직경(D)을 기준으로 전단 -3D에서부터 후단 7D까지 압력계를 설치하여 밸브의 개도율을 조절하며 데이터를 취득하는 직관 거리 시험을 실시하였으며, 관로에 수직으로 상단(180°)부터 하단(0°)까지 45° 각도 간격으로 압력계를 설치한 후 수직 위치 시험을 실시하였으며, 이 결과들을 바탕으로 압력계의 최적 위치선정 방안을 제시하고자 한다.

• 한국유체기계학회 논문집
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• 제16권4호
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• pp.5-9
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• 2013

An experimental investigation has been carried out in order to evaluate characteristics of wetted-type multi-path ultrasonic flowmeters. The multi-path ultrasonic flowmeters were installed at various entrance and exit locations for several cases of pipe fitting(straight, $90^{\circ}$ double elbow) and valve(gate valve, butterfly valve). We measured the flow-rate at each location. The measurement data of test flowmeter were compared with the measured data of reference flowmeter. The uncertainties of reference flowmeter and test flowmeter are 0.3 %, 0.4 %, respectively. The results demonstrate the effects of flowmeter location as well as the measurement errors in flow rate. The distance between the flow disturbance factor and a flowmeter was an important element of the test.

• 한국자동차공학회논문집
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• 제24권2호
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• pp.232-241
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• 2016

The turbocharger, to decrease the harmful exhaust gas(CO, HC and etc.) and $CO_2$ emission as well as the increase of the engine output, would be an useful method for engine downsizing. Therefore the thermal endurance of turbine blade, the lubrication of turbine shaft and the engine knock according to the supercharge of the inlet air, had been studied. And there had been much progress in these research tasks to be achieved a breakthrough. But a study on the built-in WGV of a gasoline engine for a passenger car which may effect on the engine performance, is few. In this paper, the effect of the embedded WGV on the engine performance was performed through the endurance test, which was conducted more than 300 hrs using the 4 stroke, 1998 cc, water-cooled engine. To sum up the major results, there were an abrasion in the area of the WGV head edge and the thermal deformation on the WGV head face, These phenomena led to reducing the boost pressure which caused the reduction in the volumetric efficiency of the engine. It resulted in decreasing the engine power gradually during the life cycle of the embedded WGV.

• 한국기계가공학회지
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• 제11권3호
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• pp.160-165
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• 2012

The packing, among the components comprising the gate valve, is used to sustain the air-tightness and the study on change of shape or pattern has been carried out to maximize the functions, but the study on changing the location or the size of the packing in a bid to prevent the freezing has rarely been implemented. Thus, This study is intended to evaluate the thermal strain of packing by heat transfer from territory of extremely low temperature as well as the temperature distribution to the upper part of the packing using numerical analysis method.

• 한국정밀공학회지
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• 제29권6호
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• pp.648-653
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• 2012

Cavity pressure, an important factor in injection molding process, should be minimized to enhance injection molding quality. In this study, we decided the locations of valve gates to minimize the maximum cavity pressure. To solve this problem, we integrated MAPS-3D (Mold Analysis and Plastic Solution-3Dimension), a commercial injection molding analysis CAE tool, using the file parsing method of PIAnO (Process Integration, Automation and Optimization) as a commercial process integration and design optimization tool. In order to reduce the computational time for obtaining the optimal design solution, we performed an approximate optimization using a meta-model that replaced expensive computer simulations. To generate the meta-model, computer simulations were performed at the design points selected using the optimal Latin hypercube design as an experimental design. Then, we used micro genetic algorithm equipped in PIAnO to obtain the optimal design solution. Using the proposed design approach, the maximum cavity pressure was reduced by 17.3% compared to the initial one, which clearly showed the validity of the proposed design approach.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1044-1048
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• 2006

Nuclear power generation is very dangerous in occasion that skirt of structure by earthquake although it is high effective generation that can make a lot of energies with few raw material. when design, it must consider a lot of problems caused by an earthquake. The seismic analysis of the structure has been great concern in the engineering society with an effort to reduce the severe damages from an earthquake. So the earthquake resistant design is one of the crucial design procedures of a gate valve used in nuclear power generation. The gate valve which has the contact area between stem and bellows. Because of the contact area. The gate valve should be given high stress and frictional wear. In this thesis, Considering the gate valve which has some contact distance between stem and bellows. The gate valve which has some contact distance is analyzed by a commercial FEM code of Ansys and Then compared to the gate valve behavior which doesn't have contact distance.

• 한국전자통신학회논문지
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• 제12권1호
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• pp.147-154
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• 2017

본 논문은 휴대폰에서 사용할 수 있는 IoT 기반 홈 보안 시스템을 개발한다. 제안된 시스템은 데이터를 수집하는 센서, 카메라, 게이트웨이와 Xively 플랫폼으로 구성된다. 라즈베리파이는 3 종류의 센서로부터 데이터를 수집하고, Xively로 데이터를 전송하고, 카메라의 영상화면을 인터넷을 통하여 휴대폰의 클라이언트로 전송한다. 서버는 Xively, 라즈베파이에 존재하는 소켓 서버와 Google에 있는 이메일 서버로 구성된다. 제안된 시스템은 움직임, 화재 위험, 가스 누출이 발생하면 이메일, 텍스트 문자와 영상화면을 전송하고, 라즈베리파이를 통하여 가스 밸브를 제어할 수 있다. 실험결과로부터 가스 누출 등으로 위험이 발생하면 사용자는 이메일, 문자 메서지를 전송받고, WIFI 또는 LTE를 통하여 스마트폰으로 집내의 영상화면을 볼 수 있다는 것을 확인하였다.