• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.10
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• pp.102-111
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• 2004

The procedure of design and manufacture of sub-scale combustor using bipropellant swirl injector with external mixing for a liquid rocket engine are described. The results of cold flow test, ignition test and combustion test of the sub-scale combustor are also given in this paper. The sub-scale combustor uses liquid oxygen(LOx) and kerosene as propellants and has a injector head, an ablative material combustor wall and a water cooled nozzle. The injector head has LOx manifold, fuel manifold, fire face plate, one center swirl injector and 18 main swirl injectors. The cold flow, ignition and combustion tests were successfully performed without damage of combustor. Results of hot firing tests show that combustion efficiency meets the target of design and operations of start and stop cyclogram are stable and high frequency combustion instability does not occur.

• Journal of the Korean Chemical Society
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• v.42 no.5
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• pp.531-538
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• 1998

The ion selective membrane electrode made of calix[4]arene-based host 1 as ionophore, poly (vinyl chloride) (PVC) as matrix and dioctylsebacate (DOS) as a plasticizer was studied. The potential responses of this membrane electrode to alkali, alkaline earth and transition metal cations were investigated. Especially this membrane electrode was turned out to be affinitive for $Pb^{2+}$ in the deionized water. It was observed that the response was linear in the concentration range from $1.0 \times 10^{-1} M to 1.0 \times 10^{-6} M of Pb^{2+}$ and its slope (26.5 mV/decade) was near to the sub-Nernstian response in deionized water. Also, the potential was maintained constantly in the range of pH $4.00 \sim 12.00$, which supports the potential usage as $Pb^{2+}$ affinitive electrode in the deionized water.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.551-556
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• 2017

Creation by human starts from ascribed situation. That means creating new relationships among seemingly unrelated things. The art production process requires creativity which materializes the inspiration emerging as an image. The production of sculpture utilizing waste is creative in regard of its advantage of being easy to recognize since it de-categorizes ascribed things and needs an overall view of considering decomposed sculpture elements syntagmatically according to the new image. Students have different point of view and develop creativity and originality in their curiosity of seeking something new, observing things of their vision, the standard of using material and in the process of selecting the materials, etc. This research suggests an extensive creativity education of producing sculpture, which implies the environmental consciousness and life respect, by means of change their recognition about seemingly meaningless waste.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.4
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• pp.423-430
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• 2016

The implant prosthesis can be divided into the screw retained prosthesis and cement retained prosthesis. Each type has advantages as well as disadvantages which is unfavorable to maintain the implants. To overcome these drawbacks, T-screw system was developed. T-screw system which utilizes a lingual direction of the screw to retain the implant prosthesis, has advantages of retrievability of the prosthesis, passive fit, and possibility to form esthetic and functional occlusal surface. The prior prosthesis which utilized horizontal screws had difficulty in fabrication especially in the case of multiple units, and also limited use with all-ceramic prosthesis. In this case, fabricating the implant prosthesis by using the T-screw system showed superior results in easy maintenance, esthetics, and also functions. In addition, we are to report the method of using the T-screw system in implant prosthesis, such as multiple units of implant prosthesis and all ceramic prosthesis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.61-69
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• 2008

In this paper, an automatic escalator system is manufactured for concentrate lighting efficiency and maintenance improvement technology of street light used a solar condenser. It can be linked with street light used a solar condenser, improved concentrate lighting efficiency by regulating concentrate light angle of a solar condenser. It can be remove and attach to solar condenser and street light. By developing street light used a solar condenser with an automatic escalator system, the lighting efficiency of street light and the concentrate lighting efficiency of solar condenser are High. The maintenance fee of street light significantly reduce and traffic congestion during working hours of street light is prevent.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.581-582
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• 2010

This paper performed the basic study for developing the Photodynamic Therapy Equipment for medical treatment. We developed the equipment palpating cell proliferation using a high brightness LED. This equipment was fabricated using a micro-controller and a high brightness LED, and designed to enable us to control light irradiation time, intensity, frequency and so on. Especially, to control the light irradiation frequency, FPGA was used, and to control the change of output value, TLC5941 was used. Control stage is divided into 30 step by program. Consequently, the current value could be controlled by the change of level in Continue Wave(CW) and Pulse Width Modulation(PWM), and the output of a high brightness LED could be controlled stage by stage.

• 한국HCI학회:학술대회논문집
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• 2006.02b
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• pp.442-449
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• 2006

탈 장르화와 영상의 다양화로 예술에서의 표현의 한계는 극대화 되고 있으며, 디지털 매체를 통한 인터랙션 역시 디지털 아트에서의 보편적인 표현 방법으로 전환 되었다. 예술에서의 상호작용은 보여주는 것에서 참여하는 것으로의 전환을 꿰 하고 있고, 디지털을 기반으로 한 다매체, 다중화가 이를 뒷받침 한다. 상호작용을 위한 디지털 아트 작품을 위해서는 센서를 이용한 표현방법들이 있으나, 기타의 센서도구를 사용치 않고, 단지 카메라로부터 입력된 신호만을 기반으로 영상과 관객의 상호작용을 끌어 낼 수 있다. 이를 위해서는 모션트레킹을 위한 알고리즘을 응용함으로써 사물의 밝기 값에 충족한 데이터를 만들어 낼 수 있고 그에 해당하는 밝기의 변환 값을 이용해 미세한 사물의 변화를 감지 할 수 있는 것이다. 이런 일련의 영상작업을 위해서는 사물의 움직임과 반복성을 얼마만큼 인지하고 감지 해내느냐고 관건인데, 다시 말해 한번 측정한 움직임이 있는 사물의 데이터도 프로그램상에서 계속하여 인지가 되어야 하고, 그 데이터 값을 영상으로 반환하여야 하는데, 이는 영상의 지속적인 변화를 가져 올 수 있다는 걸 의미한다. 따라서 본 논문에서는 모션 트래킹의 기본 알고리즘을 제시하고 영상작품과 인턱래션작품의 변환를 위해 사용된, 센서 대체도구인 웹 캠의 데이터 즉, 색상 값과 밝기 값을 적절하게 활용함으로써 표현의 다양성을 이끌어 내고 디지털 인터랙티브 작품으로써의 제작을 꾀하고자 한다.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.6
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• pp.1-7
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• 2009

The gas turbine engine performance is greatly relied on its component performance characteristics. Generally, acquisition of component maps is not easy for engine purchasers because it is an expensive intellectual property of gas turbine engine supplier. In the previous work, the maps were inversely generated from engine performance deck data, but this method is limited to obtain the realistic maps due to calculated performance deck data. Therefore this work proposes newly to generate more realistic compressor map from experimental performance test data. And then a realistic compressor map can be generated form those processed data using the proposed extended scaling method at each rotational speed. Evaluation can be made through comparison between performance analysis results using the performance simulation program including the generated compressor map and on-condition monitoring performance data.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.173-176
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• 2010

A subscale gas generator was designed and manufactured to understand a reason for increased pressure drop of liquid oxygen injectors observed in a technology demonstration model of a 75 ton-class gas generator. A total of 6 hot-firing tests were successfully performed including experimental conditions of design and off-design points. The hot-firing results showed that discharge coefficients of fuel and liquid oxygen remained constant as the mixture ratio varied at a fixed chamber pressure. At a fixed mixture ratio, it was also found that discharge coefficients of fuel and liquid oxygen was constant as the chamber pressure was increased.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.2
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• pp.89-94
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• 2014

This research notes dramatic increase of wheelchair usage along with rapidly aging population and handicapped people in Korea. Differentiated from existing electronic wheelchairs, we have invented an electronic wheelchair that is collapsible even when the battery is installed and a guardian can ride along with a patient. It is also easy to put in a small space such as car trunks. Additionally, we have improved stoic design to be preferable for patients. The model ensures there's neither abrupt acceleration nor sudden stop and, lastly, is much cheaper than other imported models.