• Title/Summary/Keyword: continuum

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Shape Optimization of Three-Dimensional Continuum Structures by Force Approximation Techniques (힘 근사화 기법에 의한 3차원 연속체 구조물의 형상최적화)

  • Han, Sang Hoon;Lee, Woong Jong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.1
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    • pp.39-46
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    • 1993
  • The need to develop method which can improve the shape design efficiency using high quality approximation is being brought up. In this study, to perform shape optimal design of three-dimensional continuum structures an efficient approximation method for stress constraints is proposed, based on expanding the nodal forces in Taylor series with respect to shape variables. Numerical examples are performed using the 3-D cantilever beam and fixed-fixed beam and compared with other method to demonstrate the efficiency and convergence rate of the Force Approximation method. It is shown that by taking advantage of this high quality approximation, the total number of finite element analysis required for shape optimization of 3-D continuum structures can be reduced significantly, resulting to the same level of efficiency achieved previously in sizing optimization problems. Also, shape representation by super curve technique applied to obtain optimal shape finds useful method.

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The Continuum of Rehabilitation Care and the Rehabilitation Services that are Needed by People with Severe Disabilities (재가 중증 장애인의 지속적 재활 관리 실태와 재활 서비스 요구)

  • Jang, Soong-Nang;Kim, Wan-Ho;Lee, Kyu-Beom;Kim, Su-Kyung;Lim, Jae-Young;Rhee, Seon-Ja
    • Journal of Preventive Medicine and Public Health
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    • v.39 no.3
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    • pp.263-269
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    • 2006
  • Objectives: As the number of people with disabilities is increasing and their needs for care are varied, the continuum and comprehensiveness of their rehabilitative care are getting more important. This study was performed to understand the utilization of rehabilitation services and requirements of care among the people with severe disabilities in Korea. Methods: We interviewed 578 disabled persons who had severe extremity and cerebral impairment in the urban and rural areas of Korea. The questionnaire included questions on their general characteristics, the type of disability, their physical function (ADL, IADL), their use of rehabilitation services after discharge and their requirements for rehabilitation care Results: Only 12.6% of people with disability in the community continuously used the available medical rehabilitation care. The associated factors for utilization of rehabilitation services were pain and admission for rehabilitative treatment in the acute phase. There was a great need for rehabilitation services in community and this varied according to gender, the socio-economic status, the functional status and the geographic region. The gap between utilization and need for rehabilitation services was largest in the economic support. The gap of primary health care was larger in the rural area than in the urban area. Conclusions: The needs for rehabilitation service were diverse according to the individual functional status, the regional characteristics and other general characteristics of people with disability. Strategies should be considered to eliminate the barriers to obtain rehabilitation services for the people with disability in the community.

The Factors that Affect on CRM Performance in a Medical Institution (의료기관의 CRM 성과와 영향 요인)

  • Lee, Jae-Hong;Min, Kyung-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.2
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    • pp.758-764
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    • 2010
  • This study showed effective and new applicative direction of CRM of medical management after arranging CRM researches, measuring CRM activity and the results of medical institutions and clearing factors having an effect. In other words, 'Human Factors' variables and 'Physical Factors' variables have an effect on the result of CRM. 'Human Factors' variables have an effect on the qualitative result and 'Physical Factors' variables have an effect on the quantitative performance. In more strategic CRM continuum, Human Factors have a significant effect on the whole performance of CRM. And in more tactical, CRM continuum Human Factors and Physical Factors have significant effect on the whole performance of CRM. Consequently, The key point is grasp of what characteristics exist in CRM between strategic level and tactical level. This provides the foundation for the variables in marketing practice.

Elastic-plastic formulation for concrete encased sections interaction diagram tracing

  • Fenollosa, Ernesto;Gil, Enrique;Cabrera, Ivan;Vercher, Jose
    • Steel and Composite Structures
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    • v.19 no.4
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    • pp.861-876
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    • 2015
  • Composite sections design consists on checking that the point defined by axial load and bending moment keeps included within the surface enclosed by the section interaction curve. Eurocode 4 suggests a method for tracing this diagram based on the plastic stress distribution method. However curves obtained according to this criterion overvalue concrete encased sections bearing capacity, especially when axial force comes with high bending moment values, so a correction factor is required. This article proposes a method for tracing this diagram based on the strain compatibility method. When stresses on the section are integrated by considering the Navier hypothesis, the use of the materials nonlinear constitutive equations provides curves much more adjusted to reality. This process requires the use of rather complex software which might reveal as too complex for practitioners. Preserving the same criteria of an elastic-plastic stress distribution, this article presents alternative expressions to obtain the failure internal forces in five significant points of the interaction diagram having considered five different positions of the neutral axis. These expressions are simply enough for their practical application. Concordance of curves traced strictly relying on these five points with those obtained by computer assisted stress integration considering the strain compatibility method and even with Eurocode 4 weighted curves will be presented for three different cross-sections and two different concrete strengths, revealing very good results.

Strength Prediction on Composite Laminates Including Material Nonlinearity and Continuum Damage Mechanics (재료 비선형과 연속체 손상역학을 고려한 복합 적층판의 강도 예측)

  • Park, Kook-Jin;Kang, Hee-Jin;Shin, Sangjoon;Choi, Ik-Hyun;Kim, Minki;Kim, Seung-Jo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.11
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    • pp.927-936
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    • 2014
  • This paper presents development and verification of the progressive failure analysis upon the composite laminates. Strength and stiffness of the fiber-reinforced composite are analyzed by property degradation approach with emphasis on the material nonlinearity and continuum damage mechanics (CDM). Longitudinal and transverse tensile modes derived from Hashin's failure criterion are used to predict the thresholds for damage initiation and growth. The modified Newton-Raphson iterative procedure is implemented for determining nonlinear elastic and viscoelastic constitutive relations. Laminar properties of the composite are obtained by experiments. Prediction on the un-notched tensile (UNT) specimen is performed under the laminate level. Stress-strain curves and strength results are compared with the experimental measurement. It is concluded that the present nonlinear CDM approach is capable of predicting the strength and stiffness more accurately than the corresponding linear CDM one does.