• 제목/요약/키워드: limitation

검색결과 8,420건 처리시간 0.042초

Eddy current compensation using a gradient system modeling in MR Spiral scan imaging (MR Spiral scan 영상에서 Gradient system의 모델링을 이용한 Eddy current compensation)

  • Cho, S.H.;Kim, P.K.;Kang, S.W.;Ahn, C.B.
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.339-340
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    • 2007
  • Gradient system에 spiral waveform 입력을 가하면 Hardware limitation에 의하여 만들어지는 gradient fields에 Transient time delay가 발생한다. 이를 보상하기 위하여, Gradient system을 R-L-C 회로로 모델링하여 재구성에 필요한 k-space trajectory를 보정하여 개선된 image를 획득하였다.

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Study on the effect of GND via on High-speed signal transmission (고속 신호 전송에 대한 GND Via 의 효과 연구)

  • Im, Jang-Hyuk;Kim, Young-Kil
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 한국해양정보통신학회 2010년도 춘계학술대회
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    • pp.695-698
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    • 2010
  • 본 논문은 High-speed signal에 대한 기본적인 설계 방법론, Differential signaling, Impedence matching, Decoupling Method 등에 대하여 논한 후 High-speed signal 의 전송 품질을 개선하기 위한 GND via 의 효과에 대하여 논하고자 한다. S-parameter simulation 및 실제 제품 적용 후 파형의 변화를 관찰하여 GND via 의 효용성을 살펴보아 High-speed signal Design 할 때 Design limitation 상황에 대해 적절한 방법론을 말하고자 한다.

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A Snubber Design for Low Power Dissipation and Overvoltage Limitation in Three-Level GTO Inverters (3-레벨 GTO 인버터를 위한 새로운 스너버회로 설계)

  • Suh, Jae-Hyeong;Suh, Bum-Seok;Hyun, Dong-Seok
    • Proceedings of the KIEE Conference
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    • 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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    • pp.153-155
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    • 1994
  • This paper presents a new low loss snubber including the overvoltage snubber for three-level GTO inverters. The proposed snubber can not only minimizes the snubber loss and the number of components but also improve blocking voltage balancing problem between the inner and the outer GTOs.

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Towards 4-dimensional Geographic Information Systems

  • Lee, Seong-Ho;Park, Jong-Hyun
    • Proceedings of the KSRS Conference
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.473-475
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    • 2003
  • To overcome the limitation that traditional GISs lose much information for the real world, 4-dimensional GIS has the additional reference systems including object's height and temporal dimension. This paper describes the 4-dimensional geometric object model and components. The prototype for 4-dimensional GIS consists of the data provider, manager, and renderer components. We show the virtual city that its database contains topographic maps, buildings, roads and temporal history data. This provides spatial, temporal operations and analysis functions.

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The Application of NMR Techniques to the Structural Confirmation of O-Substituted 3,4-Dihydroxyphenylacetic Acid Derivatives

  • Lee, Sueg-Geun;Choi, Joong-Kwon;Park, No-Sang;Hong, Mi-Sook;Ha, Deok-Chan
    • Bulletin of the Korean Chemical Society
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    • 제13권1호
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    • pp.87-91
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    • 1992
  • The structures of the compounds, 1, 2, 3, and 4, which were precursors of analgesics, were confirmed by modern NMR techniques. The complete $^{13}C-NMR$ assignments of these systems were established by applying COLOC (COrrelated spectroscopy for LOng range Couplings), HETCOR (HETeronuclear CORrelated spectroscopy), RCT (Relay Coherence Transfer), and NOE difference spectroscopy. The limitation of COLOC approach which has been widely used recently is discussed.

Optimal Tolerance Design within Limited Costs using Genetic Algorithm (유전 알고리즘을 이용한 한계비용내의 최적 공차 설계)

  • 장현수;이병기;김선호
    • Journal of Korean Society of Industrial and Systems Engineering
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    • 제22권49호
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    • pp.33-41
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    • 1999
  • The original tolerances, which are assigned by designers on the basis of handbooks and experience, cannot always be expected to be optimal or feasible, because they may yield an unacceptable manufacturing costs. So the systematic tolerance design considering manufacturing costs should be done. Therefore, this research analyzes the tolerance within the tolerance design using Monte-Carlo simulation method and sensitivity analysis and using genetic algorithm by tolerance allocation method. The genetic algorithm was developed for allocation of the optimal tolerance under the manufacturing limitation cost.

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Digital Therapeutics for Obesity Care (비만 관리를 위한 디지털 치료제)

  • Seo, Yoo Bin
    • Archives of Obesity and Metabolism
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    • 제1권2호
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    • pp.47-52
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    • 2022
  • Digital therapeutics (DTx) are emerging as a novel solution to improve lifestyle and prevent non-communicable diseases. Obesity is a complex, multi-factorial, chronic condition that requires patient-centered lifestyle modification. DTx, such as mobile applications and wearables, may offer easily accessible, efficient, and personalized care in the field of obesity and metabolic diseases. Yet, there is controversy over its clinical usefulness. This review will provide a comprehensive overview of DTx, including its potential role and current limitation in obesity care, based on recent literature.

Kinetic Characterization of Brain Distribution for KR-31378 in Rats

  • Kim, Ji-Hye;Shim, Chang-Koo;Chung, Suk-Jae
    • Proceedings of the PSK Conference
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.421.2-421.2
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    • 2002
  • Recent studies show that KR-31378 [(2S.3SAR)-N"-cyano-N-(6-amino-3A-dihydro-3-hydroxy-2-methyl-2-dimethoxymethyl-2H-benzopyran-4-yl)-N${\cdots}$-benzylguanidine] has the neuroprotective effect as evidenced by the limitation of the size of infarct of the ischemia-reperfusion injury after an administration of KR-31378. In the literature. however. kinetics of KR-31378 distribution into the brain has not been systematically studied. (omitted)

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Study of Fashion Design Applying the Formative Beauty of Architectural Works by Antoni Gaudi (패턴 절개를 응용한 의상의 조형적 형태미의 표현 연구 - 안토니오 가우디 건축 작품 형태를 중심으로 -)

  • Shin, Hyo-Jung;Lee, Young-Min
    • The Research Journal of the Costume Culture
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    • 제17권5호
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    • pp.849-865
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    • 2009
  • This research is a study of fashion design that applied formative features of formal beauty of architecture into clothing design; we focused on Gaudi's architectural style as well as Art Nouveau style that became popular from the end of the 19th century to the beginning of the 20th century. We noted that in general the simple and flat features of cloth impose a limitation on the expression of formal features in clothing design, but a unique diversity of designs can be achieved, evoking a sense of freshness by an ideal combination of flat patterns and draping. The aim of this research is to present a possibility of extending the sphere of design expression by creating three-dimensional clothes with pattern-cutting skills and applications of three-dimensional patterns as well as flat patterns found in Gaudi's works of architecture that are distinguished in curvaceousness and formal beauty. As for the research method, we reviewed previous studies by making a close review of books, papers, the pictures and web sites related to this topic. We made our clothes on the basis of this theoretical consideration. We found the following points. First, by presenting a work of fashion inspired by architectural designs, we realized that formal beauty in architect can become a motive for clothing design in a broad scale by noting the formal images, decoration details, and formative features of architectural works. Second, the characteristic lines of Gaudi's architecture are suitable to be adapted for expressing the detailed lines of decoration in clothes. Third, we can express formative beauty in clothes by highlighting the variation of shapes and lines through various attempts of change in background pattern, even though there is a limitation in the availability of cloth material because we must choose pieces of cloth with right texture and thickness that can be cut and sewn appropriately to express formative beauty. Fourth, we confirmed that it was possible to create unique formative designs by a creative application of both flat and three-dimensional cutting.

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Study on the view of human body and disease in 『Donguibogam』(1) -View of the life in 『Donguibogam』- (『동의보감』의 ‘신체관’과 ‘질병관’에 관한 연구(1) -『동의보감』에서 본 생명관-)

  • Jeong Woo Yeal
    • Journal of Physiology & Pathology in Korean Medicine
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    • 제16권1호
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    • pp.1-7
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    • 2002
  • The development of life science has given many insights into life phenomenons to mankind. Nevertheless, many questions for various phenomenon in life has not been satisfied. Recently, scientific development in human's knowledge showed the limitation of science comparing With the variety of life phenomenon. The fundmental reason of the limitation is thought that the subject of study in life science has been material, and so life has been thought a matter of material in life science. The thought of Hu Jun about this problem, the nature of living things is an important interest in Korean Traditional Medicine, Haneuihak(韓醫學). In this study, the view of human body and disease of Hu Jun(許浚) about the nature of living things which was appeared in 『Donguibogam』 was illuminated. The content of 『Donguibogam』 was edited in the order of Naekyung(內景篇; internal part of the body)ㆍOuihyung(外形編; external part of the body)ㆍJabbyung(雜病篇; diseases)ㆍTangaek(湯液偏; medicinal decoction)ㆍChimgu(針灸篇; acupuncture and moxibustion). The part of Naekyung(內景篇; internal part of the body) is thesis about basic theories and his thought about human body and life, which was seen in ‘Shinhyungjangbu-do(身形臟腑圖; figure of body and shape, and the organs and viscera)’ㆍthe part of ‘Jeong(精)’ㆍ‘Gi(氣)’ㆍ‘Sin(神)’ theory. In this study, the parts which were related with his view of life were selected and compared with the China philosohy of those days to elucidate what is his thought of life appeared in 『Donguibogam』.