• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.5
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• pp.423-429
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• 2014

Passive attitude stabilization methods using the permanent magnet combined with hysteresis damper and the gravity gradient boom have been widely used for the attitude determination and control of cube satellite, due to its advantage of system simplicity. In this paper, on-orbit thermal characteristics of the cube satellite considering the attitude profiles obtained from the above passive attitude stabilization methods have been investigated through on-orbit thermal analysis. In addition, the effectiveness of the various thermal coatings on the panel for the communication antenna installation has been verified.

• Journal of Korea Game Society
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• v.8 no.2
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• pp.47-55
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• 2008

This paper introduces that SSFE(Skeleton System for Facial Expression) to deform facial expressions by rigging of skeletons does same functions with 14 facial muscles based on anatomy. A three dimensional animation tool (MAYA 8.5) is utilized for making the SSFE that presents deformation of mesh models implementing facial expressions around eyes, nose and mouse. The SSFE has a good reusability within diverse human mesh models. The reusability of SSFE can be understood as OSMU(One Source Multi Use) of three dimensional animation production method. It can be a good alternative technique for reducing production budget of animations. It can also be used for three dimensional animation industries such as virtual reality and game.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.2
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• pp.168-175
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• 1987

In this paper, a FFH-SS hybrid communication method using digital frequency synthesizer is proposed. This can simultaneously share the same frequency band with conventional band limited communication method without interference. In the experiment the selective hopping pattern is attained by some conbination of serial to parallel conversion of maximal code from pseudo random noise generater, and it is observed that the selective hopping band transition can be more easily achieved when the hop interval is nonuniform than it is uniform. Digital frequency synthesizer is now reported to have very poor spurious suppression ability below 50~60dB, the reason of this is observed from the experimental result, and the way of how to solve this problem is presneted.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.284-284
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• 2020

지하수 흐름 모의를 위한 2차원 수조모형 실내 실험은 현장에서 발생하는 복잡성을 배재하는 동시에 간편함과 재현가능성을 제시하는 실험 방식이다. 지하수 흐름 모형은 수치모델을 구현하여 계산할 때 검증용 실험 결과를 얻는 목적으로 운용할 수 있으며 또한 테스트베드 규모의 실증 실험을 대신할 용도로 실증부지의 환경을 축소 모의하고자 하는 용도에도 사용할 수 있다. 본 연구는 모형의 길이에 비해 두께가 상대적으로 얇아 지하수 2차원을 모의할 수 있는 실내실험 방식의 표준을 제안한다. 연구 방법에서 인공 매질 및 모래와 같이 수조모형의 흐름 영역을 채우는 매질의 수리전도도 값을 간편하고 신속하게 계산하는 방식을 Dupuit 가정을 바탕으로 구현하였다. 모의하고자 하는 실증 부지와 수조 모형 사이에는 실험 규모의 축소와 확대의 근거를 이론적으로 뒷받침하는 상사성 (similarity)이 존재하여야 한다. 본 연구에서는 상사성을 구현하는데 사용할 수 있는 무차원 변수를 수리지질학적 변수의 조합으로 표현하고자 하였다. 마지막으로 무차원화 변수를 수조 모형에 대입하여 실증부지를 모의하고 결과를 표출하는 방식을 제안하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.366-366
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• 2021

도시의 기본 인프라인 배수망은 도시의 홍수를 막기위한 중요한 시설로 강우로 발생되는 유출수를 최대한 빨리 도시 밖으로 배수할 수 있도록 설계되어 왔다. 하지만 기후변화로 인하여 극한강우 빈도의 증가 및 급속한 도시화는 도시유역의 유출수를 빨리 배제하는 것이 하류의 홍수부담량을 증가시켜 하류의 홍수피해가 커지는 역설적인 현상을 초래하고 있다. 이러한 현상은 빠른 배수를 목적으로 설계되었던 배수망의 기존 설계방식이 더 이상 유의미하다고 할 수 없으며, 새로운 형태 또는 새로운 개념의 배수망 설계방식이 필요한 시점이라 할 수 있다. 본 연구는 폭함수를 이용하여 유출형태를 분석하였다. 총 512개의 조합된 네트워크를 통하여 각 네트워크별 최대 유출량 및 최대 유로 연장을 분석하여 3개의 그룹으로 분류하였다. 일부 그룹은 상류에 만곡도가 낮은 배수망을 배치하고 하류에 만곡도가 높은 배수망을 배치할 경우 유출량이 크게 증가하였으나, 그 반대의 경우인 상류에 만곡도가 높은 배수망을 배치하고 중류에 만곡도가 낮은 배수망을 배치할 경우 하류의 만곡도에 관계 없이 유출량이 감소하는 결과를 얻을수 있었다. 또한 일부 그룹에서는 상류의 만곡도를 낮게, 중류의 만곡도를 낮게, 하류의 만곡도를 낮게 배치할 경우 유량을 최소화 할 수 있는 것으로 분석되었다. 이러한 결과는 향후 배수망 설계 방식에 대한 새로운 관점을 제시하며, 배수망을 통하여 유출량을 저감시키는 것은 기존의 홍수저감 방식에 사용되는 비용절감 및 인위적 조작이 필요한 홍수저감 시설의 설치를 줄임으로서 지속가능한 도시홍수저감에 도움이 될 것으로 사료된다.

• Journal of Internet Computing and Services
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• v.13 no.1
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• pp.83-98
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• 2012

Recently Web services and SOA(Service Oriented Architecture) is widely used for an effective integration way of distributed applications. The service choreography is a way of service compositions to define workflows and the message exchange protocols among several partner ser-vices in the B2B business process environment. It defines the overall business process from a global perspective. However, it must be transformed into some kind of the executable form to implement service compositions, because it does not support an execution mechanism but is a de-clarative form. Therefore, the transformed executable model must be validated with the original choreography model to guarantee behavior equivalence. In this paper, we propose the conformity assessment with respect to service compositions method between the choreography model and the transformed executable model. And we suggest the test method to show behavior equivalence between them from a viewpoint of the dynamic execution.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1147-1154
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• 1999

We developed three-wavelength solar bank which is a very important part of the solar simulator with the commercial mercury lamps and projected halogen lamps. This was developed to satisfy simultaneously following three points: the ${\pm}10%$ uniformity of irradiance of the target area and irradiance in the each wave region and $1120W/m^2$ maximum irradiance of the solar in the summer. We used spectral radiance to determine the standard of the spectral irradiance and developed the perfect three-wavelength solar bank,considering of directionality, irradiance distance, interval both lamps, lamps combination and lamp numbers based on the measured spectral irradiance. To proof the capability of the three wavelength solar bank, We carefully analyzed color differences and heat transfer. As a result, we found that three wavelength solar bank was much better than commercial infrared lamp bank in terms of the color differences, heat transfer phenomena.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.569-580
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• 2008

Web services are the current most promising technology for service oriented architecture(SOA) implementations. However, in spite of the large scale acceptance of web services, they have been relegated to internal integration projects, and the grand vision of virtual enterprises where partners can be integrated on demand is yet to be realized. The main reason is that the current standards of web services are not very suitable for the dynamic web service discovery and integration. In this paper, we present a novel SemanticBPEL solution that merges the benefit of WS-BPEL, with the advantage of OWL-S for building a semi-automatic web service composition system. In particular, this work proposes a multi-phase search method for solving dynamic discovery and integration problems of web services. The proposed method is compared with the existing keyword based retrieval method. These comparisons show that our approach outperforms the existing method.

• Geophysics and Geophysical Exploration
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• v.14 no.3
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• pp.185-190
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• 2011

In marine controlled-source electromagnetic (CSEM) modeling, it may be difficult to evaluate primary fields accurately using conventional linear filters because they decay very rapidly with distance. However, since there exists a closed-form solution to the Hankel transform in TM mode for a homogeneous half space, we can assess the accuracy of linear filters for evaluating the Hankel transform. As a result, only nine out of 36 source-receiver pairs show that EM fields decrease linearly in semi-log scale with an increase of source-receiver distance, while EM fields are either 0 or not reduced significantly due to an effect of the air layer. There also exist closed-form solutions for the nine pairs, and the others can be evaluated accurately with a relatively short filter. This paper proposes a method which uses closed-form solutions for TM-mode Hankel transforms and a filter with 61 coefficients for TE-mode ones.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1487-1493
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• 2008

In order to investigate the cooling capacity of multi-heat pump applying an inverter compressor, the experiment on the cooling performance characteristics of heat pump with 3 indoor units was performed under the cooling standard and cooling low-temperature conditions. The system data were measured by the psychrometric calorimeter. The operation characteristics and the behavior of the cooling cycle of the heat pump with 3 indoor units were understood from the cooling capacity, COP, and P-h diagram by indoor-unit combination. The operating load and performance of the multi-heat pump depends on the indoor-unit combination. The cooling capacity and COP of the low temperature condition were larger than those of the standard one. Also the cycle was analyzed by using P-h diagram.