• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.72-77
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• 2017

This paper focuses on the development of a supporting S/W tool for the automated design of an automotive press trim die. To define the die design process based on automation, we analyze the press die design process of the current industry and group repetitive works in the 3D modeling process. The proposed system consists of two modules, namely the template models of the trim steel parts and UI function for their auto-positioning. Four kinds of template models are developed to adapt to various situations and the rules of the interaction formula which are used for checking and correcting the directions of the datum point, datum curve, datum plane are implemented to eliminate errors. The system was developed using CATIA Knowledgeware, CAA(CATIA SDK) and Visual C++, in order for it to function as a plug-in module of CATIA V5, which is one of the major 3D CAD systems in the manufacturing industry. The developed system was tested by applying it to various panels of current automobiles and the results showed that it reduces the time-cost by 74% compared to the traditional method.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2006.03a
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• pp.195-203
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• 2006

The crossing construction under railroad have two methods which are cut and cover and trenchless method. first, cut and cover method is an extremely limited method concerning non-running time. Whereas, trenchless method is free from restriction such as train speed and running time, and has the strong points of safe and rapid construction. Front Jacking method, one of the trenchless methods, is frequently applied recently due to its stability during construction and vantage of assuring schedule reliability. The procedure is that after minimizing interlocking friction with structure and earth pressure due to jacking the small steel tube, pulling the precast box manufactured at the field in the ground using PC strand and hydraulic Jack. This method is able to be applied regardless of section size and length of box and condition of ground. And that is also pro-environmental. This paper presents the case of Daejeon E. W. perforate Road Project applied with the Front Jacking method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.4
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• pp.828-834
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• 2009

To get a better profit, standalone mobile game market shifts network-based mobile game. Currently, most of the game platform are separated into mobile to mobile, desktop to desktop, and console to console. Multi platform network game has a diverse problems including consistency control, object management technique, and bandwidth inconsistency. n this paper, we will introduce a multi-platform arcade game "Push-Push", which is played on desktop to mobile environment. The game guarantees realtime play between heterogeneous machine users and game item sharing between two platforms. e will focus n the issues of the 3rd generation multi platform games and propose some techniques or solving these problems. Our server database is implemented on MS SQL database, also the desktop programming tool is Visual Basic, and WIPI(Wireless Internet Platform or Interoperability) as a mobile platform.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.646-654
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• 2005

The crossing construction under railroad have two methods which are cut and cover and trenchless method. First, cut and cover method is an extremely limited method concerning non-running time. Whereas, trenchless method is free from restriction such as train speed and running time, and has the strong points of safe and rapid construction. Front Jacking method, one of the trenchless methods, is frequently applied recently due to its stability during construction and vantage of assuring schedule reliability. The procedure is that after minimizing interlocking friction with structure and earth pressure due to jacking the small steel tube, pulling the precast box manufactured at the field in the ground using PC strand and hydraulic Jack. This method is able to be applied regardless of section size and length of box and condition of soil. And that is also pro-environmental. This paper presents the case of Daejeon E. W. perforate Road Project applied with the Front Jacking method.

• Journal of Biosystems Engineering
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• v.31 no.5 s.118
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• pp.423-429
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• 2006

The heat pump water heater developed in this research consisted of one evaporator, one compressor, 1st condenser, 2nd condenser, one expansion valve, one water tank, one recirculation circuit and etc. The performance of heat pump water heater was tested and analyzed. The quantities of output water changed linearly from 2380 to $660{\ell}/h$, and the output water temperature changed curvedly from 29.9 to $44.5^{\circ}C$ when the opening rate of recirculation valve changed from 0 to 100%. The COP of heat pump water heater increased from 3.0 to 3.8 when the quantities of output water changed from 660 to $2380{\ell}/h$. When the temperature distributions of water tank were measured during 50 minutes after turning on the heat pump, the temperature stratification by the level appeared apparently. When the inlet water temperature changed from 30 to$50^{\circ}C$, the output energy of heat pump hardly changed. The surface area of double pipe heat exchanger changed from 0.429 to $6.254m^2$ when the compressor capacity increased from 1.0 to 50.0 PS.

• Journal of Biosystems Engineering
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• v.32 no.1 s.120
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• pp.30-36
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• 2007

Geothermal heat pump systems use the earth as a heat source in heating mode and a heat sink in cooling mode. These systems can be used for heating or cooling systems in farm facilities such as greenhouses for protected horticulture, cattle sheds, mushroom house, etc. A horizontal type means that a geothermal heat exchanger is laid in the trench buried in 1.2 to 1.8 m depth. Because a horizontal type has advantages of low installation, operation and maintenance costs compared to a vertical type, it is easy to be adopted to agriculture. In this study, to heat and cool farm facilities and obtain basic data for practical application of horizontal geothermal heat pump systems in agriculture, a horizontal geothermal heat pump system of 10 RT scale was installed in greenhouse. Heating performance of this system was estimated. The horizontal geothermal heat pump used in this study had heating COP of 4.57 at soil temperature of 14$^{\circ}C$ for depth of 1.75m and heating COP of 3.75 at soil temperature of 7$^{\circ}C$ for the same depth. The stratification of water temperature in heat tank appeared during the whole heat rejection period.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.587-589
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• 2009

The districts of underground geologic structure in Jeju island where underground air is distributed are lava cave, pyroclastic, open joint, and crushing zone. Such districts are identified to secure an enough airflow when air ventilation layer is to secure 25-35m in depth. In Jeju, Ground air is used for heating greenhouse and fertilizing natural $CO_2$ gas by suppling directly into greenhouse. But the heating method by suppling ground air into greenhouse directly bring about several problem. The occurrence of disease of the crops by high humidity is worried because the underground air which becomes discharge from underground air layer has over 90% relative humidity. The underground air is inadequate in heating for crops which need high temperature heating such as mangos, Hallbong and mandarin orange because the temperature of it is $15{\sim}18^{\circ}C$. Also There is worry where the ventilation loss becomes larger because the air pressure inside greenhouse is high by supplying underground air directly. In this study the heat pump system using underground air as heat source was developed and heating performance of the system was analysed. Heating COP of the system was 2.5~5.0 and rejecting heat into greenhouse and extracting heat from underground air were 40,000~27,000 kcal/h, 30,000~18,000 kcal/h respectively.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.03a
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• pp.219-219
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• 1999

마직물은 통기성, 흡수성, 투습성이 좋고 건조가 빠른 편이므로 여름철 직물로 많이 사용되어 왔다. 마직물은 또한 뻣뻣하며 몸에 감기지 않고 촉감이 깔깔하여 시원한 느낌을 주며 다른 직물에 비해 강직하고 표면이 거칠고 드레이프성이 떨어지는 등의 독특한 태를 가지고 있다. KES-F 시험기에 의해 여러 물성량들을 종합적으로 계측할 수 있게 됨에 따라 의복의 착용감에 만족을 주는 소재의 성능에 대한 연구가 종래의 주관적평가에서 KES-F 시스템을 이용하여 객관적으로 태를 예측하는 방법으로 진행되고 있다. 그러나 태를 평가하는 객관적 방법에서는 일반적으로 Kawabata와 Niwa에 의해 만들어진 평가식들이 주로 사용되나 이런 식들은 주로 모직물이나 합성섬유직물들을 평가하기에는 적합하지만 마직물의 독특한 태를 평가하기에는 부족하다고 생각된다. 마직물의 태가 기존의 객관적 평가방법만으로는 규명되지 않기 때문에 주관적 태평가방법을 아울러 실시해야 할 필요가 있다고 생각된다. 따라서 본 연구에서는 마직물의 태를 평가하는 방법의 하나로 주관적 평가척도를 개발하고 이 척도를 사용하여 마직물의 주관적인 태 특성을 살펴보았다. 그리고 KES-FB 시스템을 사용한 객관적인 태를 측정하여 주관적 평가치와 객관적 측정치로부터 태 평가의 산출식을 유도하였다. 실험에 사용된 직물은 혼방률, 밀도, 두께 등이 다양한 암, 저마 그리고 마혼방직물과 한산모시, 중국마, 신합섬 직물 등 총 54종을 사용하였다. 마직물의 주관적 태 평가를 위해 26문항의 형용사쌍으로 구성된 9점의 의미미분척도를 개발하였으며 이 척도를 사용해 주관적 평가를 실시하였다. 또 객관적 평가를 위해 KES-FB 시스템을 통해 역학적 특성치를 구하였다. 주관적 평가를 실시한 결과 마직물의 태에 영향을 미치는 7개의 요인이 추출되었다. 이 요인들은 표면성질, 신축성/드레이프성, 중량감, 강연성, 회복성, 수분특성, 밀도감이었으며, 요인들로 설명되는 누적분산값은 67.18%였다.주관적 평가의 결과와 객관적 평가 결과를 이용해 마직물의 태를 평가하는 산출식을 제시하였다. 태 평가치의 경우 16가지 특성치를 모두 넣는 방법과 stepwise 방법, 또 Kawabatark 사용한 순차적 군 회귀법의 세가지 방법의 회귀식 중 16가지 특성치를 모두 넣는 방법의 결정계수가 가장 높았다.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.372-378
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• 2012

This study was carried out in order to determine the optimum length of a roll type PE pipe heat exchanger employed in the water-to-water heat pump system using the waste heat of the heated effluent flowed out from thermal power generation plants as a heat source. And the heat pump system of 30 RT for an experimental test was designed and manufactured. And also PE pipes were employed to recover the waste heat from the heated effluent. The inside diameter of PE pipe heat exchanger was 20 mm, the thickness was 2 mm and the diameter of a roll was 1,000 mm. And from the results of this study, we found that the optimum length of PE pipe heat exchanger was 75 m per the heat pump capacity of 1.0 RT (3.51 kW) and then the heating COP of heat pump system was 3.8.

• Journal of Biosystems Engineering
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• v.32 no.4
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• pp.247-255
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• 2007

During the winter season in Korea, the relative humidity of greenhouse at night often exceeds 90% because air temperature inside the greenhouse is usually controlled using a heater with all of windows closed to minimize heat loss, thereby requiring the use of a dehumidifier that can maintain optimum humidity levels of $70{\sim}80%$ to provide a good growth condition of crops. Also, such a high humid condition can cause the development of a pest, such as insects, fungi or diseases. However, the use of most conventional dehumidifiers for low temperature dehumidification is limited because their performance is degraded due to frost accumulation on the evaporator coil. This study was carried out to develop a refrigeratory-based dehumidifier suitable for low temperature dehumidification in greenhouse cultivation. The developed dehumidifier consists of a condenser and an evaporator installed separately so that relative and absolute humidity levels can be reduced when air passed through the condenser and evaporator, respectively. The prototype dehumidifier showed a dehumidification capacity of $5{\sim}7kg/h$ when air with a temperature of $15{\sim}25^{\circ}C$ and a relative humidity of $70{\sim}95%$ came into the dehumidifier. Under the condition that either temperature or relative humidity was fixed, the amount of condensed water was proportional to the levels of both temperature and relative humidity.