• 제목/요약/키워드: carrying

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분산형 복합재료의 손상 메커니즘 (Damage Mechanics in Particle or short-Fiber Reinforced Composite)

  • 조영태
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1998년도 추계학술대회 논문집
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    • pp.287-292
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    • 1998
  • In particle or short-fiber reinforced composites. cracking of the reinforcements is a significant damage mode because the broken reinforcements lose load carrying capacity. This paper deals with the load carrying capacity of intact and broken ellipsoidal inhomogeneities embedded in an infinite body and a damage theory of particle or short-fiber reinforce composites. The average stress in the inhomogeneity represents its load carrying capacity. and the difference between the average stresses of the intact t and broken inhomogeneities indicates the loss of load carrying capacity due to cracking damage. The composite in damage process contains intact and broken reinforcements in a matrix. An incremental constitutive relation of particle or short-fiber reinforced composites including the progressive cracking damage of the reinforcements have been developed based on the Eshelby's equivalent inclusion method and Mori and Tanaka's mean field concept. Influence of the cracking damage on the stress-strain response of the composites is demonstrated.

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초고압 GIS 모선의 통전설계를 위한 교류자계해석 (Ac Magnetic Field Analysis of Current Carrying Conductor Design for EHV GIS)

  • 김현훈;이정섭;한성진;정진교;이병윤;박경엽
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제48권5호
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    • pp.233-240
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    • 1999
  • The current carrying conductor and the tank which consist of GIS must be properly designed to withstand the electrical, thermal and mechanical stresses that arise during normal service and during short-circuit conditions. In order to design the current carrying conductor for EHV GIS, it is important to consider temperature-rise when rated current flows. In this paper, we analyze magnetic field distribution and power-loss, according to the change of materials when AC current flows into single-phase and three-phase bus bar, respectively. These results will be used as the basic design data when determining dimensions and materials for the current carrying conductor of EHV GIS.

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Hot-spot 응력을 이용한 십자형 필렛 용접재의 피로강도 평가 (Fatigue Strength Assessment of the Cruciform Fillet Welded Joint Using Hot-spot Stress Approach)

  • 석창성;김대진;구재민;서정원;구병춘
    • 대한기계학회논문집A
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    • 제29권11호
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    • pp.1488-1493
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    • 2005
  • In this study, fatigue tests to obtain S-N curves and FE analyses to obtain structural stress concentration factors were conducted for the two types of cruciform fillet welded joints, that is, load-carrying and non load-carrying types. Then we changed the obtained S-N curve of load carrying joint to that based on hot spot stress. As a result, the S-N curve of load carrying joint based on hot-spot stress was almost exactly coincided with that of non load-carrying joint based on nominal stress. So we have conducted that the fatigue strength of a welded joint with different geometry from the non stress distribution along the expected crack path.

Recreation Ecology and Visitor Carrying Capacity Management: Implications for Protected Areas in East Asia

  • Leung, Yu-Fai;Lee, Ju-Hee
    • The Korean Journal of Ecology
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    • 제26권2호
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    • pp.53-58
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    • 2003
  • Ever-growing recreation, tourism and ecotourism worldwide have become a significant factor of resource degradation in many protected areas. Managers of these areas are increasingly challenged to implement policies, strategies and actions that would protect the resource base while providing quality visitor experience. One major issue in managing protected area visitations is that of carrying capacity, or the question of "how much use is too much\ulcorner". Scientific studies of visitor impacts, often known as recreation ecology, has generated a knowledge base that provides valuable input to the visitor carrying capacity management process adopted by the U.S. National Park Service. This paper aims at (a) providing an overview of recreation ecology research and its application in managing visitor carrying capacity, and (b) examining the relevance of recreation ecology to East Asian protected areas with special reference to the visitor capacity issue.ity issue.

교량의 공용내하력과 환산충격계수 관계 연구 (The Relationship between the Load Carrying Capacity and Transformed Impact Factor of Highway Bridge)

  • 채원규;이명구
    • 한국안전학회지
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    • 제27권6호
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    • pp.138-143
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    • 2012
  • In this thesis, the relationship between the load carrying capacity and the transformed impact factor of the highway bridges were studied. The bridges are classified according to superstructures type. The result of the comparison between the load carrying capacity and the transformed impact factor, if the load capacity ratio of 0.57, the transformed impact factor was less in order of RC T-beam bridge, RC slab bridge, PC beam bridge, I-beam bridge. By the regression analysis on these results, the empirical formulae to predict the the load carrying capacity of bridge were suggested.

선정릉의 적정수용능력추정 및 관리방안(II) (Carrying Capacity Estimation and Management Planning of the Seonjeong Royal Tomb(II))

  • 이경재;오구균;조재창
    • 한국조경학회지
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    • 제15권2호
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    • pp.79-90
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    • 1987
  • This second consecutive research was connected to 7he previous first research with same title. The purpose of this research is to estimate the carrying capacity for the Seonjeong royal tomb and to propose its management planning. User's characteristics and relationship between user's density and vegetational environment were analized for the above objective. The result of this research shall be summarized as follows. 1. The site was damaged seriously by pupils and social groups'picnic activities concentrated in special periods of Friday and weekend during April and May. 2. Social-psychological carrying capacity estimation would be impossible due to lack of relationship between user's density and satisfaction. 3. Maximum user's density limits as a ecological carrying capacity was 1.4 persons per 100 square meters and modified optimum ecological carrying capacity was estimated as 1.0persons per 100 square meters. Maximum visitors as a optimum carrying capacity of the Seonjeong royal tomb area was estimated as 6,000 persons when supposing the proposed landuse planning. 4. To restore and preserve the tomb landscape as a traditional historic site, Seonjeong royal tomb shall be managed by three landuse areas ; protection and control area, natural picnic area and shaded picnic area. And the protection and control area include three sites ; natural reclamation site, natural preservation site and tomb landscape conservation site.

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패션에서의 캐링 시스템[Carrying System]에 관한 사적 변천 (The Historical Change of Carrying Systems in Fashion)

  • 우주형;박명희
    • 복식
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    • 제56권8호
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    • pp.45-59
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    • 2006
  • The change into the information society converts people's daily lift into nomadic lifestyle, and this change of lifestyle needs to reinforce the portability in fashion. The purpose of this study is to know the historical diversion of the rallying system, characteristics and reason of this change after recognizing of the implication of fashion and portable methods. The carrying system from the primitive age to modern society was changed from use of body to designing potable equipments - belts, wrapping cloths, bags, pockets, etc. These are changed by modifying of the form of society and fashion. This change result from the development of technique, the entry of women in public affair, the change of life style, the impoverishment of nature. The carrying system of modern fashion means not only the spares in the clothing, but also a new attached system in which nomadic necessities are transformed or unified. The carrying system becomes one of the important details which designers cannot neglect in designing, and must be. developed with consideration of use and function.

Comparison of Bag Weight and Applied Location on Plantar Pressure and Gait in the Twenties Student

  • Jinho Yu;Jaecheol Park;Mingyun Ko
    • Physical Therapy Rehabilitation Science
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    • 제12권2호
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    • pp.155-160
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    • 2023
  • Objective: The purpose of this study is to confirm a comparison of bag weight and applied location change on plantar pressure and gait parameters (stride time, stride length, cadence) of the 20s students. Design: One group cross-sectional design Methods: The subjects were measured in each condition. Each condition was no carrying a bag, carrying a 3kg bag, and a 6kg bag on the right shoulder, and walked on the gait analyzer. After the location of the bag was changed, measured when a 3kg backpack and a 6kg backpack was each carried on the back while walking. Results: There was a statistically significant difference in plantar pressure according to bag weight when carried on the right shoulder (p<0.05). As a result of the post-hoc analysis, carrying a 6kg bag was a significant difference between no carrying a bag and carrying a 3kg bag (p<0.05). There was no statistically significant difference in changes in stride time, stride length, and cadence. There was no statistically significant difference in plantar pressure and gait parameters according to backpack weight. Conclusions: As a result of this study, it is thought that it will be possible to present a method for the application of the correct bag on location and weight in 20s students, and to prevent and reduce muscle musculoskeletal system diseases caused by incorrect bag wearing.

119구급대원의 업무 관련성 근골격계 질환 위험성 평가 : 환자 운반 작업을 중심으로 (Assessing the risk of work-related musculoskeletal disorders in 119 EMT: a focus on patient-carrying tasks)

  • 손정원
    • 한국응급구조학회지
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    • 제27권3호
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    • pp.33-46
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    • 2023
  • Purpose: This study aims to evaluate the risk of work-related musculoskeletal disorders (WMSDs) in 119 EMT during patient-carrying tasks using a long backboard (LBB) and a variable stretcher. Methods: Manikins were used as patients, and 45 new 119 EMT from K Fire Academy were filmed performing patient-carrying tasks on stairs. The tasks were analyzed using Ovako working posture analysis system (OWAS) and Rapid entire body assessment (REBA). Results: In using LBB, the OWAS score was Mode 3(Mean 2.37, Maximum 3), requiring as soon as possible corrective action, the REBA score was Mode 11(Mean 9.16, Maximum 11), requiring immediate improvement. In using variable stretcher, the OWAS score was Mode 1(Mean 2.33, Maximum 3), non-necessity for corrective action, the REBA score was Mode 9(Mean 8.0, Maximum 11), requiring as soon as possible. Conclusion: In conclusion, improvement was needed in one task (carrying a patient using a LBB) in the OWAS and in two tasks (carrying a patient using a LBB, carrying a patient using a variable stretcher) in the REBA. Thereby, required attention and management of WMSDs during training. In addition, it is essential to carry out objective and quantitative assessments through ergonomic analysis by occupational health professionals when designing future training programs to prevent WMSDs.

거제한산만 굴양식장의 지속적 이용을 위한 생태지표의 적용 (Application of Ecological Indicator to Sustainable Use of Oyster Culture Grounds in GeojeHansan Bay, Korea)

  • 조윤식;홍석진;박성은;정래홍;이원찬;이석모
    • 해양환경안전학회지
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    • 제16권1호
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    • pp.21-29
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    • 2010
  • 지금까지 연안 양식장의 지속적인 생산 및 체계적인 관리를 위해 어장환경용량 산정 및 활용에 관하여 많은 연구가 선행되어 왔다. 그러나, 생태학적 부하를 고려한 지속적 적정 생산을 위해서는 4가지 계층구조(물리적 수용능력, 생산 수용능력, 생태학적 수용능력 및 사회적 수용능력)에 의한 어장환경용량 산정 개념을 활용할 수 있다. 생태학적 수용 능력 산정의 경우, 환경과 패류 양식의 상호작용에 관한 좀 더 전체적인 접근이 필요하여 아직까지 모델 개발은 초기 단계에 있으므로, 이에 대한 대안접근으로 패류양식장이 해양생태계의 가능을 어떻게 변화시킬 수 있는지 패류양식장의 생태적 효율을 평가할 수 있는 생태지표의 필요성이 대두되었다. 현재 거제한산만 굴양식장의 정화율 생태지표는 0.331, 여과압 생태지표는 0.203으로 계산되었으며, 이는 연안 생태계에 부하를 주지 않는 생태학적 수용 능력인 0.05를 초과하고 있음을 나타내었다. 본 연구에서는 생태학적 수용 능력의 개념에 근거한 생태지표를 거제한산만에 적용하여, 현재의 굴 양식장의 개발 수준이 어느 정도인지를 평가하여 지속적인 생산과 효과적인 양식어장 관리 지침으로 활용하는 방안을 마련하고자 하였다.