• 제목/요약/키워드: Flexibility Analysis

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유연 매니퓰레이터 동역학 모델링의 비선형 커플링 요소 (Nonlinear Coupling Factor in Dynamic Model of Flexible Manipulator)

  • 이진호;임성수;이순걸
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 추계학술대회 논문집
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    • pp.404-408
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    • 2005
  • Having flexibility in a manipulator will degrade trajectory tracking control and manipulator tip positioning. In practice, however, constraints imposed by various operating requirements, will render the presence of such flexibility unavoidable. The dynamic analysis of the flexible manipulator is essential in designing proper control systems. A flexible manipulator consists of infinite number of elastic modes and the modes are usually coupled to each other. For the practicality, however, it is usually assumed that the flexible system consists of finite number of elastic modes and the modes are decoupled. These assumptions result in a linear and decoupled mathematical model of the flexible manipulator and simplify the analysis of the dynamic behavior and the design of the control system. The decoupling and linearization of the flexible link, however, has been assumed without in depth analysis. This paper focuses on the analysis of the significance of the non-linear coupling factors.

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강성변화의 선체응답에의 영향 (Effect of Flexibility Variations on Ship Responses)

  • 권영섭
    • 한국해양공학회지
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    • 제6권2호
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    • pp.151-171
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    • 1992
  • 선체응답의 변화를 고찰, 계산 결과를 요약하였다. 이에 대한 계산은 유체 동력학적 해석을 이용하였으며 본 이론의 합리성을 아울러 지적하였다. 선체의 유연성을 증가시킴으로서 추격선두 굽힘 모멘트는 줄지만, 모멘컴 굽힘 모멘트는 일반적으로 증가함이 나타났다.

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작업공간의설계-CAD에 의한 접근 (Workplace design-A CAD approach)

  • 이남식;박경수
    • 대한인간공학회지
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    • 제1권1호
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    • pp.29-34
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    • 1982
  • Traditional methodologies for ergonomic evaluation are too laborious to be accepted broadly. CAD flex- flexibility and its ease can be a key to breaking this barrier. In this paper, a biokinematic modelis suggested for interactive computer aided ergonomic evaluation. Model parameters are derived and validated by regression analysis. This model showes more flexibility than the stick and joint models. An application is presented to show the clarity of this approach.

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신경가동기법, 정적신장기법, 유지-이완기법이 뇌졸중 환자의 슬괵근 유연성에 미치는 효과 비교 (Comparison of Nerve Mobilization, Static Stretching, and Hold-Relax on Hamstring Flexibility in Stroke Patients)

  • 성재현;최종덕
    • 한국전문물리치료학회지
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    • 제17권2호
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    • pp.67-74
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    • 2010
  • The purpose of this study was to examine the acute effects of nerve mobilization, static stretching, and hold-relax on the flexibility of hamstring muscles and their surface electromyographic (EMG) responses to passive stretches in poststroke hemiparesis. This study was a randomized cross-over trial. Fourteen subjects received three treatment sessions in random order with each consisting of ten repetitions. The treatment sessions included nerve mobilization, static stretching, and hold-relax. The treatment sessions were held at least 24 hours apart to minimize any carryover effect. The outcome was measured by the distance between the greater trochanter and lateral malleolus and hamstring EMG activity during passive knee extension stretching. Repeated-measures analysis of variance showed significant changes in hamstring flexibility and EMG activity in main effect of time pre, post and followup (p<.05). However, no significant differences occurred among the three stretching techniques. No technique was consistently found to be superior. The three stretching techniques in this study make it difficult to determine the most effective technique. Therefore, clinicians use nerve mobilization of effective stretching techniques with other stretching techniques.

수산자원의 가격형성모형의 선택에 관한 연구 (A Study on the Choice of Price Formation Models for Fishery Resources)

  • 박환재
    • 수산경영론집
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    • 제44권1호
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    • pp.59-70
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    • 2013
  • The purpose of this paper is to integrate various models of price formation and let the data choose the most proper model. After the data choose the proper model, one can analyze the price formation process and demand structures for fishery resources under the restriction of Korean fisheries regulations. This study suggests the integrated model including quasi-linear price formation model, Translog price formation model, AIDS price formation model and Lewbel price formation model as level variables. It also suggests another integrated model including AIDS price formation model, Rotterdam price formation model, Latinen-Theil price formation model and Neves price formation model as difference variables. The empirical results show that the AIDS price formation model is the most preferred in both level and difference variables of fishery resources. The estimated parameters show that all sample species have (-) sign of price flexibilities, thus following the law of demand. The scale flexibilities of all species are estimated as (-) sign, thus being adapted to the theory. The contribution and results are summarized as follows. First, the integrated model of fishery market demand has been developed and the data can choose the proper model without arbitrary choice of the researcher. Second, the fishery market demand structure could be analyzed in a way different from the ordinary demand analysis, which is based upon price flexibility and scale flexibility. Third, the integrated model for fishery resources can be used easily when catching restrictions are imposed by policies.

오픈 하우징의 가변성 대응 계획수법 비교 연구 - 일본, 네덜란드, 핀란드의 오픈 하우징 사례분석을 중심으로 - (A Study on the Comparative Analysis of Flexible Design Methods on Open Housing)

  • 김수암;이성옥;황은경;임석호
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2005년도 추계학술대회 논문집
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    • pp.157-162
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    • 2005
  • It is necessary for us to research and analyze of Open Housing in order to change new housing system, because exiting multi family housing is lack of flexibility and easy remodeling. The purpose of this study is to supply and grasp basic planning and design data for flexibility of Open Housings in Korea. This study is based on the literature survey and actual investigation through visiting 17 open housing sites from 1995 to 2005 in Netherlands, Finland and Japan, which are main Open Housing. We analyzed the planning methods and elements for flexibility of open housing block and unit plan, and described the contents of analyses. We found a lot of planning and design methods-supplying option plan and user participation before occupation, various structural system for openness, common piping shaft location, slab-down and applying access flooring system, movable and demountable partition wall system etc. -applied to the open housings, and findings are applicable to the planning and designing works of apartment housings in Korea.

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Blast load induced response and the associated damage of buildings considering SSI

  • Mahmoud, Sayed
    • Earthquakes and Structures
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    • 제7권3호
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    • pp.349-365
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    • 2014
  • The dynamic response of structures under extremely short duration dynamic loads is of great concern nowadays. This paper investigates structures' response as well as the associated structural damage to explosive loads considering and ignoring the supporting soil flexibility effect. In the analysis, buildings are modeled by two alternate approaches namely, (1) building with fixed supports, (2) building with supports accounting for soil-flexibility. A lumped parameter model with spring-dashpot elements is incorporated at the base of the building model to simulate the horizontal and rotational movements of supporting soil. The soil flexibility for various shear wave velocities has been considered in the investigation. In addition, the influence of variation of lateral natural periods of building models on the obtained response and peak response time-histories besides damage indices has also been investigated under blast loads with different peak over static pressures. The Dynamic response is obtained by solving the governing equations of motion of the considered building model using a developed Matlab code based on the finite element toolbox CALFEM. The predicted results expressed in time-domain by the building model incorporating SSI effect are compared with the corresponding model results ignoring soil flexibility effect. The results show that the effect of surrounding soil medium leads to significant changes in the obtained dynamic response of the considered systems and hence cannot be simply ignored in damage assessment and response time-histories of structures where it increases response and amplifies damage of structures subjected to blast loads. Moreover, the numerical results provide an understanding of level of damage of structure through the computed damage indices.

An Empirical Study on the Effect of Trust between Firms in the Supply Chain on Agility and Logistics Performance

  • Soohyo KIM;Changjoon LEE;Byoung Chun HA
    • 유통과학연구
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    • 제22권7호
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    • pp.95-106
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    • 2024
  • Purpose: This study explores the effect on supply chain agility and logistics performance of building mutual trust between manufacturing companies that have adopted supply chain management. Previous studies have categorized trust into affective and cognitive types, and speed, flexibility, and responsiveness are recognized as subfactors of supply chain agility. Methodology: A survey gathered responses from employees of domestic manufacturing firms with supply chain management implementations. 254 valid responses underwent statistical analysis using structural equation modeling (SPSS 23.0 and AMOS 23.0). Results: Affective trust positively influences speed and responsiveness but not flexibility. Cognitive trust positively affects speed, flexibility, and responsiveness. Supply chain agility positively impacts logistics performance. However, neither affective nor cognitive trust significantly influences logistics performance. Conclusions: The study suggests that cognitive trust based on capabilities is more important than affective trust for flexibility in corporate relationships, a subfactor of supply chain agility. However, trust alone cannot enhance corporate performance. This research is significant as it examines the roles of trust and agility in the context of the COVID-19 pandemic, which has exacerbated the manufacturing business environment.

이동질량과 크랙을 가진 단순지지 보의 동특성에 관한 연구 (A Study on the Dynamic Behavior of a Simply Supported Beam with Moving Masses and Cracks)

  • 윤한익;손인수;조정래
    • 한국해양공학회지
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    • 제17권6호
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    • pp.47-52
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    • 2003
  • To determine the effect of transverse open crack on the dynamic behavior of simply-supported Euler-Bernoulli beam with the moving masses, an iterative modal analysis approach is developed. The influence of depth and position of the crack in the beam, on the dynamic behavior of the simply supported beam system, have been studied by numerical method. The cracked section is represented by a local flexibility matrix, connecting two undamaged beam segments that is, the crack is modeled as a rotational spring. This flexibility matrix defines the relationship between the displacements and forces across the crack section, and is derived by applying a fundamental fracture mechanics theory. As the depth of the crack is increased, the mid-span deflection of the simply-supported beam, with the moving mass, is increased. The crack is positioned in the middle point of the pipe, and the mid-span defection of the simply-supported pipe represents maximum deflection.

A comparative study of along and cross-wind responses of a tall chimney with and without flexibility of soil

  • Gorski, Piotr;Chmielewski, Tadeusz
    • Wind and Structures
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    • 제11권2호
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    • pp.121-135
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    • 2008
  • The paper is concerned with a comparative study of both the along and cross-wind responses of a tall industrial chimney with and without flexibility of soil. The along-wind response has been estimated by means of approaches presented in three Standards: the Polish, the ISO and the Eurocode and by random vibration approach which is outlined below. The cross-wind response has been estimated by means of the three models developed by Vickery and Basu, Ruscheweyh and Flaga and methods presented in Standards: the Polish, the ISO and the Eurocode (Approach 1 and 2). Computer programmes were developed to obtain estimates of responses of a six-flue, 250 m-tall chimney. The analytical results computed according to the methods presented in different standards and random vibration approaches have been compared. Some unexpected conclusions have been observed.