• 제목/요약/키워드: energy principle

검색결과 1,027건 처리시간 0.025초

Mixed finite element model for laminated composite beams

  • Desai, Y.M.;Ramtekkar, G.S.
    • Structural Engineering and Mechanics
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    • 제13권3호
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    • pp.261-276
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    • 2002
  • A novel, 6-node, two-dimensional mixed finite element (FE) model has been developed to analyze laminated composite beams by using the minimum potential energy principle. The model has been formulated by considering four degrees of freedom (two displacement components u, w and two transverse stress components ${\sigma}_z$, $\tau_{xz}$) per node. The transverse stress components have been invoked as nodal degrees of freedom by using the fundamental elasticity equations. Thus, the present mixed finite element model not only ensures the continuity of transverse stress and displacement fields through the thickness of the laminated beams but also maintains the fundamental elasticity relationship between the components of stress, strain and displacement fields throughout the elastic continuum. This is an important feature of the present formulation, which has not been observed in various mixed formulations available in the literature. Results obtained from the model have been shown to be in excellent agreement with the elasticity solutions for thin as well as thick laminated composite beams. A few results for a cross-ply beam under fixed support conditions are also presented.

전해질 수용액의 고온 열역학 (High Temperature Thermodynamics of Aqueous electrolyte Solutions)

  • 이만승
    • 자원리싸이클링
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    • 제27권2호
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    • pp.63-67
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    • 2018
  • 자유에너지는 물질의 상대적인 안정도를 나타낸다. 수용액에 존재하는 이온의 종류는 다양하고 실험조건이 광범위하므로 열역학 자료가 부족하다. 이온의 표준생성엔탈피와 엔트로피로부터 표준수화엔탈피와 표준수화엔트로피의 절대값과 상대값을 구하는 방법을 설명하였다. 또한 대응원리를 이용하여 고온에서 열역학 자료를 추산하는 방법을 설명하였다.

Study on the Embedded SPC System Bused on LAN

  • Yin, Jianjun;Yu, Zhonghua;Wu, Zhaotong
    • International Journal of Quality Innovation
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    • 제4권1호
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    • pp.205-212
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    • 2003
  • Statistical Process Control (SPC) is recognized as one of the most important tool of quality control (QC), and is one research focus in order to implement SPC quickly and effectively using computer technology and network environments. This paper proposes the principle and topology of embedded SPC based on the Internet/lntranet, emphatically discusses the embedded data sampling block, embedded network interface and SPC strategy. An example of application is given.

플라이백 컨버터에서 누설인덕턴스 저장에너지의 새로운 회복회로 (A Novel Recovery Circuit of a Leakage Inductance Stored Energy in Flyback Converter)

  • 정용채
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2005년도 전력전자학술대회 논문집
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    • pp.526-528
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    • 2005
  • Nowadays, more than ever before, many researchers are paying attention to raising the efficiency of a Power converter. In Flyback converter, the resistor of RCD snubber consumes the stored energy in leakage inductor. It play a role in degrading the overall system efficiency Thus, In this paper, a novel energy recovery circuit of Flyback converter is proposed to improve the efficiency. The operational principle of the proposed circuit is explained in detail. And, it is verified through the simulation results.

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$SF_6$ 가스를 이용한 배전급 RMU용 소호부 개발 (Development of Medium Voltage $SF_6$ Interrupter for RMU)

  • 이방욱;손종만;서정민;최중웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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    • pp.301-304
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    • 2001
  • This paper considers the research of the hybrid interrupter which adopts both rotating arc and thermal expansion technology. The operating principle of this device defends on rapid arc rotation due to the magnetic field created by the fault current through a coil which is mounted on contacts and also relies on the principle of thermal expansion created by arc energy in extinguishing chamber and finally causes pressure rise in expansion volume. In this research, the principle of the interrupting techniques are given and experimental results of hybrid interrupter which is developed by new technology is introduced.

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분자의 전기음성도에 관한 이론적 고찰 (On the Electronegativity of Molecule)

  • 김호징;김종현
    • 대한화학회지
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    • 제29권1호
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    • pp.3-8
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    • 1985
  • Density functional theory에서의 전기음성도의 정의에 의해 전기음성도를 가전자(valence electron)만을 고려하여 구하였다. 전기음성도는 Hartree-Fock의 궤도 에너지(orbital energy)로 표시되는데 이로부터 구한 분자의 전기음성도 값은 다른 값들과 좋은 상관관계(correlation)를 보여준다. 또한 분자를 형성할 때 Sanderson의 법칙(electronegativity equalization principle)이 만족됨을 보였다.

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사암침법(舍巖鍼法)의 변형(變形)에 관(關)한 연구(硏究) (The Study on The variational Forms of Sa-Ahm's 5 Element Acupuncture Method)

  • 김달호;김중한
    • 한국한의학연구원논문집
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    • 제2권1호
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    • pp.337-380
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    • 1996
  • 'Nei Jing(內徑)' first defined the interrelationship of the true and tile false between evil factor affecting health(雅氣) and vital essence energy(精氣). According to 「'Nei Jing(內徑)', the above interrelationship is explained as 'If state of evil domination is considered as sthenia-syndrome(雅氣盛則實), if the consumption of healthy energy Is considered as asenia-syndrome(精氣尊則虛): 'Nei Jing(內徑)', proposed major features of the medicall treatment by 'regluate the vatal energy of asthenia and sthenia, treat the sthenia-syndrome by purgation, and treat the asenia-syndrome by therapy of invigoration(調其氣之虛實, 實則瀉之, 虛則補之): The above interrelationship was interpreted as 'treat the asthenia-syndrome of child organ by invigorating the mother organ(虛者補其母)'in the 69th of 'The Classic on Difficulty',(難經 六十九難). Go-Mu(高武) of Myung-dynasty describe therapy for invigoration and purgation of itself-meridian(自經 補瀉法), which locating acupuncture points according to the Therorr of Five Element in the five shu points of itself-meridian(自經 五유穴), based on the generation in the ${\ulcorner}$A Synthetical Book of Acupuncture and Moxibustion(針灸聚英)${\lrcorner}$, Sae-hyun Jang(張世賢) further extended location acupuncture points of the five shu points to the other-meridian in the ${\ulcorner}$Gyeo Jung Do Ju Nan Gyung(校正圖註難經)${\lrcorner}$ Sa-Ahm's 5 Element Acupuncture Method(舍嚴五行鍼法) was originated in 1644, the middle of the Yi-dynasty. It linked the reinforcing and reducing in acupuncture therapy which incorporated tlle asthenia-syndrome and sthenia-syndrome of the hollow organs, based on principle of the Yin Yang 5 Element Theory(陰陽五行學說), not only to the generation in the 5 element(相生關係) but also to the restriction in the 5 element(相剋關係). Furthermore it was devised for the medical treatment by comning therapy for invigoration and purgation of itself-meridian(自經 補瀉法) with that of the other-meridian. Even though many original forms(正形) of the therapy for invigoration and purgation of the Yin Yang 5 Element Theory comply with the principle of the generation and the restriction based on the principle of the Yin Yang 5 Element Theory are abailable, variational forms(變形) are also recognized by examining the nature of the Sa-Ahm's 5 Element Acupuncture Method(舍嚴五行鍼法), For this reason, it is very difficult to understand the Sa-Ahm's 5 Element Acupuncture Method(舍嚴五行鍼法) thoroughly. therefore, those variational forms are obstacles for the beginners to study the Sa-Ahm's 5 Element Acupuncture Method. In order to understand the principle of the practical clinical application of the Sa-Ahm's 5 Element Acupuncture Method, this study investigated which principle was based on the variations of the locating acupuncture points' method for the acupuncture prescription.

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Genetic Diversity among Korean Bermudagrass (Cynodon spp.) Ecotypes Characterized by Morphological, Cytological and Molecular Approaches

  • Kang, Si-Yong;Lee, Geung-Joo;Lim, Ki Byung;Lee, Hye Jung;Park, In Sook;Chung, Sung Jin;Kim, Jin-Baek;Kim, Dong Sub;Rhee, Hye Kyung
    • Molecules and Cells
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    • 제25권2호
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    • pp.163-171
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    • 2008
  • The genus Cynodon comprises ten species. The objective of this study was to evaluate the genetic diversity of Korean bermudagrasses at the morphological, cytological and molecular levels. Morphological parameters, the nuclear DNA content and ploidy levels were observed in 43 bermudagrass ecotypes. AFLP markers were evaluated to define the genetic diversity, and chromosome counts were made to confirm the inferred cytotypes. Nuclear DNA contents were in the ranges 1.42-1.56, 1.94-2.19, 2.54, and 2.77-2.85 pg/2C for the triploid, tetraploid, pentaploid, and hexaploid accessions, respectively. The inferred cytotypes were triploid (2n = 3x = 27), tetraploid (2n = 4x = 36), pentaploid (2n = 5x = 45), and hexaploid (2n = 6x = 54), but the majority of the collections were tetraploid (81%). Mitotic chromosome counts verified the corresponding ploidy levels. The fast growing fine-textured ecotypes had lower ploidy levels, while the pentaploids and hexaploids were coarse types. The genetic similarity ranged from 0.42 to 0.94 with an average of 0.64. UPGMA cluster analysis and principle coordinate analysis separated the ecotypes into 6 distinct groups. The genetic similarity suggests natural hybridization between the different cytotypes, which could be useful resources for future breeding and genetic studies.

사용편의성 향상을 위한 피부과 에너지베이스디바이스의 PUI 디자인 평가원칙 연구 (The PUI design evaluation principles of EBD is helpful in the dermatology clinic)

  • 정제윤;이해진;남원석
    • 한국융합학회논문지
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    • 제12권4호
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    • pp.141-149
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    • 2021
  • 피부과에서 치료를 목적으로 사용하는 에너지베이스디바이스(EBD)의 경우 디자인으로써 접근이 어려우며, 사용자의 범위가 좁기 때문에 사용자의 편의성을 고려한 연구 자료가 부족한 것이 현실이다. 본 연구는 피부과 EBD의 사용자 관점에서 의사와 간호사가 느끼는 문제점과 니즈를 분석하고, 그에 대한 개선 방향을 모색한 연구논문이다. 문헌조사와 관찰 조사를 통해 EBD의 유형과 구성요소를 파악한 후. 사용자를 대상으로 사용현황 및 만족도 설문을 통해 EBD의 구성요소별 문제점을 파악하였다. 그 후 전문가 집단 토론을 통해 에너지베이스디바이스의 PUI 디자인 사용편의성 평가원칙을 도출하였다. 본 논문에서 도출된 EBD의 PUI 디자인 사용편의성 평가원칙은 EBD 디자인의 문제점을 보완하는 기초자료로 사용될 수 있으며, 앞으로 디자인될 EBD의 사용편의성을 향상시킬 것으로 판단된다.