• Journal of Mechanical Science and Technology
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• 제17권6호
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• pp.825-835
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• 2003

Previous studies have demonstrated the importance of joint angle errors mainly due to skin artifact and measurement errors during gait analysis. Joint angle errors lead to unreliable kinematics and kinetic analyses in the investigation of human motion. The purpose of this paper is to present the Joint Averaging Coordinate System (JACS) method for human gait analysis. The JACS method is based on the concept of statistical data reduction of anatomically referenced marker data. Since markers are not attached to rigid bodies, different marker combinations lead to slightly different predictions of joint angles. These different combinations can be averaged in order to provide a "best" estimate of joint angle. Results of a gait analysis are presented using clinically meaningful terminology to provide better communication with clinical personal. In order to verify the developed JACS method, a simple three-dimensional knee joint contact model was developed, employing an absolute coordinate system without using any kinematics constraint in which thigh and shank segments can be derived independently. In the experimental data recovery, the separation and penetration distance of the knee joint is supposed to be zero during one gait cycle if there are no errors in the experimental data. Using the JACS method, the separation and penetration error was reduced compared to well-developed existing methods such as ACRS and Spoor & Veldpaus method. The separation and penetration distance ranged up to 15 mm and 12 mm using the Spoor & Veldpaus and ACRS method, respectively, compared to 9 mm using JACS method. Statistical methods like the JACS can be applied in conjunction with existing techniques that reduce systematic errors in marker location, leading to an improved assessment of human gait.

• 한국도로학회논문집
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• 제13권3호
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• pp.65-73
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• 2011

최근 들어 도로포장의 품질 개선을 위해 성능보증 계약제도를 도입하려는 연구가 활발히 진행되고 있다. 성능보증 계약제도는 구조물이 준공 이후부터 일정한 공용기간 동안 미리 정해진 성능수준을 유지할 것을 시공자가 보증하는 계약의 한 형태이다. 성능보증 계약제도는 구조물의 품질향상, 생애주기비용의 절감, 시공기술 개발 등에 기여하는 것으로 알려져 유럽 및 미국에서 사용이 증가되고 있다. 이 계약제도를 국내에 효과적으로 도입하기 위해서는 도로포장의 성능인자, 임계한도, 그리고 성능보증 기간에 대한 연구가 반드시 필요하다. 본 연구에서는 미국 미네소타, 인디애나, 플로리다 주의 콘크리트 포장 성능보증계약제도에 관한 문헌을 조사하였다. 국내 21개 고속국도 노선의 줄눈 콘크리트 포장 구간에서 포장성능에 영향을 미치는 주요 파손을 조사 및 분석하여 해외의 성능인자, 임계한도, 그리고 성능보증 기간과 비교하였다. 계획된 구간에서 장기간에 걸쳐 조사가 실시된다면 보다 정확한 비교가 가능할 것으로 예상된다.

• 한국시뮬레이션학회논문지
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• 제22권4호
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• pp.29-38
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• 2013

국방 M&S 분야에서 모의 기반 획득 방법이 필수적인 정책으로 인식되면서 획득 단계별 M&S 적용을 위한 협업이 필요해지고 M&S 컴포넌트를 쉽게 개발하고 공유하기 위한 공통 기반환경의 구축이 필요하게 되었다. 이를 위하여 본 연구에서는 모델 개발 재사용성 향상을 위한 형식론 기반의 시뮬레이션 프레임워크와 신속 개발을 위한 GUI 기반 모델링 환경을 제안한다. 제안하는 프레임워크는 플러그인 기반으로 동작하며 XML 기반 객체 모델을 바탕으로 하고 있기 때문에 모델의 개발과 변경에 대해 유연한 설계를 할 수 있으며 외부체계 연동, 모델 데이터 로깅과 같은 시뮬레이션 지원 기능을 구현하는데 효과적이다. 본 논문에서는 이러한 프레임워크 및 모델링 개발 도구의 구조와 기능 요소들에 대해 설명한다.

• 한국정보통신학회논문지
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• 제20권5호
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• pp.942-948
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• 2016

WSN은 센서 노드에 의해 구성된 네트워크로, 센서 노드는 한번 배치되면 재충전하거나 위치적으로 재배치가 불가능하다. 또한 센서노드들은 제한된 에너지를 가지고 통신에 참여하게 된다. 그러나 기존 제안되었던 클러스터링 기법들은 불균일한 분포로 배치된 WSN환경에 적용 시 지역적 특징으로 통신 단절이 발생되는 문제점으로 네트워크의 신뢰성에 문제점을 갖는다. 따라서 제안 알고리즘에서는 WSN환경에서 센서노드의 불균형 배치를 고려해 센서필드를 분할하고 분할영역의 센서노드 밀집도에 따라 고정, 정적, 동적 클러스터링 알고리즘을 선별적으로 적용함으로 센서노드의 통신 참여율을 25% 향상시켰다. 그리고 전체 네트워크 생명주기는 14%연장하여 네트워크의 신뢰성을 보장하였다.

• 생약학회지
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• 제39권4호
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• pp.271-289
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• 2008

In the Oriental Medicine field the great three reference books are Hwantienaekyung(黃帝內徑, HJNK), Sihnnongbonchokyung(神農本草經, BCK) and Shanghanlun(SHR). HJNK has been a theory book regarded as a bible of the Oriental Medicine, BCK, a herbal book with 365 species of red letters noticed from Bonchokyungjipjoo(本草經集註) and SHR, very important clinical book with concrete prescriptions for the therapy of patients. Though these books were written by Chinese people ca. 2000 years ago, yet they are no doubt very important and effective ones in these days. Unfortunately they are handed down to all transmitted books for a long times because original ones were destroyed by fire and another troubles. In this study we have tried to extract three common terminological words and common theories from the prescription law by theoretical principles(理法方藥, clinical therapeutic mechanism) acquired through the comparative analysis of these three books. They are qi(氣), cold or heat(寒熱) and yin & yang(陰陽), and their practical basic theories have been evidenced through exterior & interior of body(表裏) and deficiency or exessiveness(虛實) by the heat of Sun. Also we would have realized that Oriental Medicine should be analyzed through various scientific techniques and clinical experiences, and necessarily unified to yin & yang monism from qi theory of the Sun in all human's life cycle(生老病死).

• 한국항행학회논문지
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• 제21권1호
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• pp.50-57
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• 2017

최근 국내에서 추진된 항공 관련 안전필수시스템 기술 개발 사업들이 중도에 종료되거나 최종 단계에서 실용화되지 못하는 사례가 종종 발생했다. 사업실패의 원인은 여러 가지 요인이 있겠지만 본 연구에서는 불완전한 시험평가 절차에 주안점을 두고 관련 연구를 수행하였다. 일반적으로 안전필수시스템의 시험평가 프로세스는 시스템의 전 수명주기에 걸쳐 분포되고 단계별 연속성을 가져야 하며 시스템 설계 및 획득 전략의 성숙도에 따라 다양한 방법으로 실행될 수 있다. 본 논문의 목적은 국내 안전필수 항행시스템 개발 사업의 리스크를 줄이고 성공률을 높이기 위한 방안으로 국내외 시험평가 프로세스를 분석하여 새로운 전략을 제시하는 것이다. 먼저 안전필수시스템에 대한 검증 및 확인 기법에 대해 토의하고 선진기관의 시험평가 프로세스 및 절차와 국내 현황을 분석한 뒤 국내외 시험평가 프로세스를 비교함으로써 불완전한 시험평가 절차에 대한 보완책을 제시하였다.

• 한국한의학연구원논문집
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• 제8권2호통권9호
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• pp.95-107
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• 2002

Yukmijihwang-tang(YM) is a noted herbal prescription in Chinese and Korean traditional medicines, and it has been known to reinforce the vital essence and has been widely used for a variety of disease such as stroke, osteoporosis, anti-tumor, and hypothyrodism. Regarding its traditional use, YM has been known to reinforce the Yin (vital essence) of liver and kidney. Also it has been known to reinforce nutrition and biological function in brain. Recently, studies suggested that YM increase antioxidant activities and exert the protective effect against oxidant-induced liver cell injury. We investigated the high-throughput gene expression analysis on the Yukmijihwang-tang administrated in SD rats. Microarray data were validated on a limited number of genes by semiquantitative RT-PCR and Western blot analyses. The recent availability of microarrays provides an attractive strategy for elaborating an unbiased molecular profile of large number of genes in drug discovery This experimental approach offers the potential to identify molecules or cellular pathways not previously associated with herbal medicine. Total RNA from normal control brain and Yukmijihwang-tang administrated brain were hybridized to microarrays containing 10,000 rat genes. The 52 genes were found to be up-regulated(twice or more) excluding EST gene. The nine genes were found to be down-regulated(twice or more) excluding EST gene. Gene array technology was used to identify for the first time many genes expression pathway analysis that arecell cycle pathway, apoptosis pathway, electron transport chain pathway, cytoplasmic ribosomal protein pathway, fatty acid degradation pathway, and TGF-beta signaling pathway. These differentially expressed genes pathway analysis have not previously been iavestigated in the context of herbal medicine efficacy and represent novel factors for further study of the mechanism of herbal medicine efficacy.

• 한국건축시공학회지
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• 제6권1호
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• pp.87-91
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• 2006

Since water leakage and cracks are not the source of serious problems such as long-term lowering of performance and durability of a stricture, including damages to operating facilities of a structure, damages to internal finishing materials, exhibition, and goods, and pollution of residential environment, they might have led to development of positive coping skills; however, an instant loss of lives or property due to earthquake, explosion, typhoon, or a fire was indeed neglected. In these days, repair materials for leakage cannot help but being taken in temporary way without any noticeable countermeasure. This kind of repair is socially criticized many times that is defective construction even if this costs a lot. It was not arrange the standard for construction methods of sealer of injection type for leakage maintenance, even it has been used various type of construction methods for leakage part. In conclusion, we suggest that the construction methods of sealer of injection type for leakage maintenance for leakage to establish the leakage repairing technology as increase of structure demand. Therefore, it would be possible to provide a stage-by-stage solution by developing systematic research activities among the industry, schools, and research institutes to spread maintenance management techniques globally through technical solution to water leakage and cracks, acquisition of structural safety with prolonged durability for life cycle, reduction of water leakage repair expense s, and so on.

• 한국정밀공학회지
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• 제19권3호
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• pp.88-94
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• 2002

Recently, the life cycle and the lead-time of a product are to be shortened in order to satisfy consumer's demand. It is thus important to reduce the time and cost in manufacturing trial products. Several technique have been developed and successfully commercialized in the market of RPM(Rapid Prototyping and Manufacturing). However, most commercial systems currently use resins or waxes as the raw materials. So, the limited mechanical strength for functional testing is regarded as an obstacle towards broader application of rapid prototyping techniques. To overcome these problems, high-speed machining technology is being investigated worldwide for rapid manufacturing and even for direct rapid tooling application. In this paper, some fundamental experiments and analyses are carried out to obtain the filling time, materials, method, and process parameters for HisRP(High-Speed RP) process. HisRP is a new RP process that is combined high-speed machining with automatic filling. In filling process, Bi58-Sn alloy is chosen as filling material because of the properties of low-melting point, low coefficient of thermal expansion and no harm to environment. Also the use of filling wire it if advantage since it needs simple and flexible mechanism. Then the rapid product, for example a skull, is manufactured for aluminum material by HisRP process with an automatic set-up device thor 4-faces machining.

• Journal of Electrochemical Science and Technology
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• 제5권1호
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• pp.1-18
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• 2014

Li-air cell is an exotic type of energy storage and conversion device considered to be half battery and half fuel cell. Its successful commercialization highly depends on the timely development of key components. Among these key components, the catalyst (i.e., the core portion of the air electrode) is of critical importance and of the upmost priority. Indeed, it is expected that these catalysts will have a direct and dramatic impact on the Li-air cell's performance by reducing overpotentials, as well as by enhancing the overall capacity and cycle life of Li-air cells. Unfortunately, the technological advancement related to catalysts is sluggish at present. Based on the insights gained from this review, this sluggishness is due to challenges in both the commercialization of the catalyst, and the fundamental studies pertaining to its development. Challenges in the commercialization of the catalyst can be summarized as 1) the identification of superior materials for Li-air cell catalysts, 2) the development of fundamental, material-based assessments for potential catalyst materials, 3) the achievement of a reduction in both cost and time concerning the design of the Li-air cell catalysts. As for the challenges concerning the fundamental studies of Li-air cell catalysts, they are 1) the development of experimental techniques for determining both the nano and micro structure of catalysts, 2) the attainment of both repeatable and verifiable experimental characteristics of catalyst degradation, 3) the development of the predictive capability pertaining to the performance of the catalyst using fundamental material properties. Therefore, under the current circumstances, it is going to be an extremely daunting task to develop appropriate catalysts for the commercialization of Li-air batteries; at least within the foreseeable future. Regardless, nano materials are expected to play a crucial role in this field.