• 제목/요약/키워드: Flexible member

검색결과 52건 처리시간 0.01초

지반의 비선형 특성이 차세대원전 구조물의 지진응답에 미치는 영향 (Effects of Soil Nonlinearity Characteristics on the Seismic Response of KNGRStructures)

  • 장영선
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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    • pp.137-146
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    • 1999
  • The SSI(Soil-Structure Interaction) analyses are being performed for the KNGR(Korean Next Generation Reactor) design because the KNGR is developed as a standard nuclear power plant concept enveloping various soil conditions. the SASSI program which adopts the flexible volume method is used for the SSI analyses. The soil curves used in the three dimensional SSI analyses of KNGR Nuclear Island(NI) structures are based on the upper bound shear modulus curve and lower bound damping degradation on SSI response the average shear modulus curve with average damping curve was used for two soil cases. This study presents the results of the variances by using different soil nonlinearity parameters based on the paametric SSI analyses. The results include the maximum member forces(shear and axial force) at the base of the NI structures and the 5% damping Floor Response Spectra (FRS) at some representative locations at the top of the NI superstructures. They are also compared together with the enveloped SSI results for eight soil cases and fixed-base analysis for rock case by using two control motions.

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칼슘 용출 열화에 의해 표면이 손상된 콘크리트 부재의 구조적 거동에 관한 해석적 연구 (Analytical Study on Structural Behavior of Surface Damaged Concrete Member by Calcium Leaching Degradation)

  • 최윤석;장용환;최소영;김일순;양은익
    • 한국구조물진단유지관리공학회 논문집
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    • 제18권4호
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    • pp.22-32
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    • 2014
  • 다양한 열화 인자에 의해 저감된 콘크리트의 내구성은 구조물의 구조적 성능과 사용 수명에 부정적인 영향을 미치게 되며 콘크리트 연구 분야 중에서도 매우 중요하고 매력적인 주제라고 할 수 있다. 이러한 이유로 콘크리트의 내구성과 관련된 많은 연구들이 발표되었으나 물리-화학적 열화에 기인하는 콘크리트의 본질적인 물성 변화에 주된 초점이 맞춰져 왔으며, 콘크리트 내구성과 구조물의 구조적 성능 사이의 관계 정립은 아직 미흡한 실정이다. 본 연구에서는 콘크리트의 강도 감소에 원인이 되는 칼슘 용출 열화를 적용하였으며, 열화 정도에 따른 구조적 거동을 평가하기 위하여 열화 손상을 입은 콘크리트 부재의 압축 및 휨 거동 실험을 수행하고 그 결과를 비선형 유한요소해석 결과와 비교 분석하였다. 연구 결과에 따르면 칼슘 용출 열화는 콘크리트의 압축 강도를 저하시키며, 열화가 진행됨에 따라 취성 거동에서 연성 거동으로 변화되는 경향을 나타냈다. 또한 열화에 의한 압축 영역의 손상 정도가 심화될수록 RC 부재의 내하력과 강성은 저하되었으며, 이러한 구조적 거동은 ABAQUS의 CDP 모델을 사용한 비선형 유한요소해석의 결과와도 비교적 잘 일치하였다.

대학생과 물리치료사의 치매노인에 대한 태도 연구 (Study on Attitude of College Students and Physical Therapists towards Seniors with Dementia)

  • 이민수;김명철;김승균
    • 대한통합의학회지
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    • 제2권2호
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    • pp.21-29
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    • 2014
  • Purpose : This study is aimed at offering basic data for fostering the flexible attitude of physical therapy students towards seniors with dementia and the clinical ability to deal with such patients without fear after employment. Method : We investigated 181 physical therapists and 225 university students by using questionnaires from August 12 to September 19 2013. The questionnaire that used in this study was consisted by question about general characteristics, knowledge of dementia, attitude of dementia. The following result was obtained by using SPSS 19.0. Result : Attitude scores for dementia, Physical therapist was 41.66. Physical Therapy student was 40.34. Non-student Department of Health was 39.22. Non-Department of Health student was affected by acquisition of dementia information and living with the elderly. Physical Therapy student had significant influence depending on the household monthly income. Non-Department of Health student had significant influence depending on student age. Physical therapist had significant influence in accordance with dementia information. Conclusion : The study has revealed that the following factors of the therapists influence their attitudes towards dementia: their age; educational level; whether or not they have a family member with dementia; whether or not they have obtained information on dementia. Based on the finding, it is necessary to foster the flexible attitude of students towards seniors with dementia and provide education on effective clinical approaches upon physical therapy.

인터넷기업에서 기업구성원 자율중심의 보안관리 방안 연구 (A Study on the Corporate Members' Autonomy-centric Security Management in the Context of Internet Companies)

  • 서현진;김정덕
    • 한국전자거래학회지
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    • 제25권1호
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    • pp.45-64
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    • 2020
  • 급변하고 있는 비즈니스 환경에서 인터넷기업들은 비즈니스 특성상 유연하고 개방적이며 자율성을 강조하는 조직문화의 특징을 가지며, 시간과 장소에 구애받지 않는 유연한 스마트 업무환경으로 변화하고 있다. 이러한 인터넷 비즈니스 환경에도 불구하고 보안관리체계는 여전히 인터넷기업의 비즈니스 환경과 조직문화를 반영하지 못하고 있으며, 이로 인해 인터넷기업에서의 통제중심의 보안관리 방식은 한계에 부딪히고 있다. 따라서 본 연구에서는 인터넷기업의 비즈니스 환경과 조직문화의 특성을 고려한 보안관리의 연구를 위해 기업구성원 자율중심의 보안역할 항목을 설계하고 개발하였다. 본 연구결과는 민첩한 비즈니스 환경과 자율적인 조직문화의 인터넷기업에서 기업구성원 자율중심의 보안관리체계를 구현하고 운영하는데 활용될 것으로 기대된다.

수산업 역할의 재인식과 기본과제 (A Reconsideration of the Fishing Industry of Korea and Its Basic Problems)

  • 최정윤
    • 수산경영론집
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    • 제28권1호
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    • pp.51-70
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    • 1997
  • The fishing industry of Korea is now i a critical transitional stage. That is, broadly speaking, there are two dominant factors that constrain the further development of Korea fishey and effective competition in the international fishing industry. First of all, the global fishing industry has experienced many significant changes due to the execution of U.N, maritime law, the establishment of EEZ(the Exclusive Economic Zones), the increased roles of WTO(the World Trade Organization) as well as Korea being a member of OECD(the Organization for Economic Co-operation and Development). Second, the fishing industry of Korea is faced with the following domestic troubles, such as the icreasing fishing expenses, insufficient labor supply, and the collapse of traditional local co-operative organizations of fishing villages, etc. However, the demand for aquatic products of home consumers not only continues to increase but also is shifting to select more valuable species, completely ignoring the above-mentioned serious pressures incurred by the Korean fishery. To solve these problems and keep developing steadily, it is necessary for the fishing industry of Korea to adopt a more active and flexible development pattern in order to reset up the regional economic base in fishing villages nation-wide and make the exploitation of fishing resources balance. The paper gives an reconsideration to the primary alternatives facing the Korean fishery and its prospective roles in a realistic and far-sighted attitude. It may serve as an endeavour in seeking an outlet for the fishing industry of korea to advance forwardly and lastingly.

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기학학적 비선형을 고려한 Zetlin형 케이블 돔 구조물의 장력제어 기법에 관한 연구 (A Study on the Stress Control Technique of Zetlin-Typed Cable Dome Structures Considering Geometrical Nonlinearity)

  • 정을석;손수덕;김승덕
    • 한국공간구조학회:학술대회논문집
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    • 한국공간구조학회 2005년도 춘계학술발표회 및 정기총회 2권1호(통권2호)
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    • pp.116-124
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    • 2005
  • The recent large-spatial structures are frequently made from light-weight structural system and it has a good mechanical efficiency and uses new materials. The large space is made by light-weight structural system using tension members mainly, and generally it is called a soft structure. The cable dome structures which are a soft structures are very flexible, the stresses and nodal coordinates of other members are changed when we control the stress of one member. Therefore, we have to do two kind of works for effective and accurate construction of the cable dome structures. The first work is making a working scenario to complete the final objective form and the second is revising constructional errors occurred in process of the actual works. These works are called constructional analysis. At this time, we have to consider geometric nonlinearity to reflect the sensitivity by the initial stresses of cable dome structures, and constructional analysis comes down to a nonlinear problem after all. In this study, we try to approach the constructional analysis of the cable dome structures using the numerical method, and then verify it.

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Molecular Cloning and NMR Characterization of the Nonreceptor Tyrosine Kinase PTK6 SH3-SH2-Linker Domain

  • Lee, Young-Min;Ahn, Kyo-Eun;Ko, Sung-Geon;Lee, Weon-Tae
    • Bulletin of the Korean Chemical Society
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    • 제30권5호
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    • pp.1043-1046
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    • 2009
  • Human protein tyrosine kinase-6 (PTK6) is a member of the non-receptor protein tyrosine kinase family and it is found in two-thirds of all breast tumors. Very recently, we proposed that the SH3 domain of PTK6 interacts with the linker region (Linker) between the SH2 and kinase domains, proving that the interaction between SH3 domain and Linker plays an important role in auto-inhibition mechanism. Residues from 1 to 191 corresponding region of SH3-SH2-Linker (SH32L) of PTK6 was cloned into the pET32a expression vector with Tobbaco etch virus (TEV) protease enzyme site by sequence homology and 3D structural model. The purified PTK6-SH32L was determined as a monomer conformation in solution. The amide proton resonances in the $^{15}N-^{1}H$ 2D-HSQC spectrum suggest that PTK6-SH32L possesses disordered structural region of the flexible/unstructured linker region. In addition, the backbone amide proton chemical shifts of the SH3 domain in the PTK6-SH32L differ from that of the independent domain, indicating that intra-molecular interaction between SH3 and Linker in the PTK6-SH32L is present.

Nonlinear analysis of cable-stayed spatial latticed structures

  • Zhou, Dai;Liu, Hongyu;Jin, Bo
    • Structural Engineering and Mechanics
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    • 제15권4호
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    • pp.415-436
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    • 2003
  • The combination of spatial latticed structures (hereafter SLS) and flexible cables, the cable-stayed spatial latticed structures (hereafter CSLS) can cross longer span. According to variation principle, a novel geometric nonlinear formulation for 3-D bar elements considering large displacement and infinitesimal rotation increments with second-order precision is developed. The cable nonlinearity is investigated and it is taken that the secant modulus method can be considered as an exact method for a cable member. The tower column with which the cables link is regarded as a special kind of beam element, and, a new simplified stiffness formulation is presented. The computational strategies for the nonlinear dynamic response of structures are given, and the ultimate load carrying capacities and seismic responses are analyzed numerically. It is noted that, compared with corresponding spatial latticed shells, the cable-stayed spatial latticed shells have more strength and more stiffness, and that the verical seismic responses of both CSLS and CLS are remarkably greater than the horizontal ones. In addition, the computation shows that the stiffness of tower column influences the performance of CSLS to a certain extent and the improvement of structural strength and stiffness of CSLS is relevant not only to cables but also to tower columns.

Multivariable Optimal Control of a Direct AC/AC Converter under Rotating dq Frames

  • Wan, Yun;Liu, Steven;Jiang, Jianguo
    • Journal of Power Electronics
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    • 제13권3호
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    • pp.419-428
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    • 2013
  • The modular multilevel cascade converter (MMCC) is a new family of multilevel power converters with modular realization and a cascaded pattern for submodules. The MMCC family can be classified by basic configurations and submodule types. One member of this family, the Hexverter, is configured as Double-Delta Full-Bridge (DDFB). It is a novel multilevel AC/AC converter with direct power conversion and comparatively fewer required components. It is appropriate for connecting two three-phase systems with different frequencies and driving an AC motor directly from a utility grid. This paper presents the dq model of a Hexverter with both of its AC systems by state-space representation, which then simplifies the continuous time-varying model into a periodic discrete time-invariant one. Then a generalized multivariable optimal control strategy for regulating the Hexverter's independent currents is developed. The resulting control structure can be adapted to other MMCCs and is flexible enough to include other control criterion while guaranteeing the original controller performance. The modeling method and control design are verified by simulation results.

1 자유도 엔드 이펙터를 갖는 여유 자유도 로봇을 사용한 브레이크 모듈 조립 (Brake Module Assembly Using a Redundant Robot Having an 1 DOF End Effector)

  • 정재웅;성영휘;주백석;권순재
    • 융합신호처리학회논문지
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    • 제15권3호
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    • pp.104-111
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    • 2014
  • 이 논문에서는 자동차의 제동장치에 사용되는 브레이크 모듈 조립 작업을 로봇을 사용하여 자동화한 사례를 소개한다. 브레이크 모듈은 하나의 토크 멤버에 두 개의 브레이크 패드와 두 개의 패드 라이너를 장착하여 조립을 완성한다. 이 조립 작업은 로봇의 방향을 자주 바꾸어 주어야하기 때문에 일반적인 산업용 로봇 핸드를 사용하면 조립 시간이 오래 걸린다. 이 논문에서는 두 가지 방법을 제안한다. 첫 번째 방법은 다섯 개의 그리퍼를 갖는 로봇 엔드 이펙터를 설계, 제작하여 기존의 산업용 6축 머니퓰레이터에 장착하여 조립 작업을 수행하는 방법이다. 이 방법에서는 두 개의 브레이크 패드와 두 개의 패드 라이너를 한꺼번에 파지하여 조립 작업을 수행하며 따라서 하나의 그리퍼 만을 가지고 있는 기존의 엔드 이펙터에 비해 조립 시간을 줄일 수 있었다. 두 번째 방법에서는 첫 번째 방법을 더욱 개선하여 엔드 이펙터가 하나의 부가적인 자유도를 가지도록 설계, 제작하여 기존의 산업용 6축 머니퓰레이터에 장착하였다. 이 방법에서는 전체 로봇 머니퓰레이터가 7 자유도를 갖는 여유자유도 머니퓰레이터가 되어 로봇의 동작을 최소화하면서 조립에 필요한 다양한 로봇 방향을 구현할 수 있었다.