• Title/Summary/Keyword: Flexible member

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

  • 장영선
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.10a
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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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Analytical Study on Structural Behavior of Surface Damaged Concrete Member by Calcium Leaching Degradation (칼슘 용출 열화에 의해 표면이 손상된 콘크리트 부재의 구조적 거동에 관한 해석적 연구)

  • Choi, Yoon-Suk;Jang, Yong-Hwan;Choi, So-Yeong;Kim, Il-Sun;Yang, Eun-Ik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.4
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    • pp.22-32
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    • 2014
  • Durability is one of the most important and attractive subjects in concrete research field because not only durability of concrete is reduced by various degradation factors but also its reduction adversely influences the structural performance and service life of concrete structure. For this reason, a considerable amount of papers associated with concrete durability have been published and those researches were mainly focused on the changes of intrinsic properties of concrete due to chemicophysical degradations. However, the relationship between durability of concrete and structural behavior of concrete member has not been well established yet. In this study, calcium leaching degradation, a cause of concrete strength reduction, was dealt with. The experiments of compressive and flexural behavior of degraded concrete member were performed to evaluate the characteristics of structural behavior according to degradation level. Finally, the results from the experiments were compared with those obtained from nonlinear FEM analysis. The results from this study clearly showed that leaching degradation leads to decrease in compressive strength and compressive behavior evolves from brittle to ductile failure pattern during the degradation process. Load capacity and flexible rigidity of the degraded RC member decreased when the degradation level increased, in compressive zone. Additionally, it was found that the values from nonlinear FEM analysis, CDP model in ABAQUS, coincided well with the experimental results.

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

  • Lee, Minsoo;Kim, Myungchul;Kim, Seungkyun
    • Journal of The Korean Society of Integrative Medicine
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    • v.2 no.2
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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.

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

  • Seo, Hyunjin;Kim, Jungduk
    • The Journal of Society for e-Business Studies
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    • v.25 no.1
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    • pp.45-64
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    • 2020
  • In the rapidly changing business environments, Internet companies have the characteristics of organizational culture that emphasize the flexible, open and autonomous nature of organizational culture, and are transforming into flexible smart working environment that is independent of time and place. Despite such an Internet business environment, the security management system still fails to reflect the business environment and organizational culture of the Internet company, and the control-focused security management system in the Internet company is facing limitations. Therefore, this study designed and developed Corporate members' autonomy-centered security items that considering the characteristics of the business environment and organizational culture of the Internet company. The results of this study are expected to be used to implement and operate corporate members' autonomy-centered security management system in internet companies with an agile business environment and an autonomous organizational culture.

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

  • 최정윤
    • The Journal of Fisheries Business Administration
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    • v.28 no.1
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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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A Study on the Stress Control Technique of Zetlin-Typed Cable Dome Structures Considering Geometrical Nonlinearity (기학학적 비선형을 고려한 Zetlin형 케이블 돔 구조물의 장력제어 기법에 관한 연구)

  • Jeong, Eul-Seok;Shon, Su-Deog;Kim, Seung-Deog
    • Proceeding of KASS Symposium
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    • 2005.05a
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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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    • v.30 no.5
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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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    • v.15 no.4
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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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    • v.13 no.3
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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.

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

  • Jeong, Jae Ung;Sung, Young-Whee;Chu, Baek-Suk;Kwon, Soon-Jae
    • Journal of the Institute of Convergence Signal Processing
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    • v.15 no.3
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    • pp.104-111
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    • 2014
  • In this paper, we deal with robotic automation for assembling car brake modules. A car brake module is comprises of a torque member, two brake pads, and two pad liners. In the assembly process, brake pads and pad liners are needed to be inserted in a torque member. If we use a typical robotic hand for the assembly, task time takes too long. So, we propose two methods. The first method is to use an end effector that has five grippers capable of gripping five assembly parts. In the first method we attached the implemented end effector to a conventional 6 degrees of freedom industrial manipulator and performed the bake module assembly task. Experimental results show that the task time is remarkably reduced. The brake module assembly task needs the robot to change its orientation frequently, so, in the second method, we added one degree of freedom to the end effector that is used in the first method. By attaching it to a conventional 6 degrees of freedom industrial manipulator, we composed a 7 degrees of freedom redundant manipulator. A redundant manipulator has the advantage of flexible manipulation so the robot can change its orientation easily and can perform assembly task very fast. Experimental results show that the second method dramatically reduce whole task time for brake module assembly.