• Title/Summary/Keyword: Carrying

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

  • 조영태
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1998.10a
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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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Ac Magnetic Field Analysis of Current Carrying Conductor Design for EHV GIS (초고압 GIS 모선의 통전설계를 위한 교류자계해석)

  • Kim, Hyeon-Hun;Lee, Jeong-Seop;Han, Seong-Jin;Jeong, Jin-Gyo;Lee, Byeong-Yun;Park, Gyeong-Yeop
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.48 no.5
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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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Fatigue Strength Assessment of the Cruciform Fillet Welded Joint Using Hot-spot Stress Approach (Hot-spot 응력을 이용한 십자형 필렛 용접재의 피로강도 평가)

  • Seok, Chang-Sung;Kim, Dae-Jin;Koo, Jae-Mean;Seo, Jung-Won;Goo, Byeong-Choon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.11 s.242
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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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    • v.26 no.2
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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.

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

  • Chai, Won-Kyu;Lee, Myeong-Gu
    • Journal of the Korean Society of Safety
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    • v.27 no.6
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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.

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

  • 이경재;오구균;조재창
    • Journal of the Korean Institute of Landscape Architecture
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    • v.15 no.2
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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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The Historical Change of Carrying Systems in Fashion (패션에서의 캐링 시스템[Carrying System]에 관한 사적 변천)

  • Woo, Ju-Hyung;Park, Myung-Hee
    • Journal of the Korean Society of Costume
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    • v.56 no.8 s.108
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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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    • v.12 no.2
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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.

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

  • Jeong-Won Son
    • The Korean Journal of Emergency Medical Services
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    • v.27 no.3
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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.

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

  • Cho, Yoon-Sik;Hong, Sok-Jin;Park, Sung-Eun;Jung, Rae-Hong;Lee, Won-Chan;Lee, Suk-Mo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.16 no.1
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    • pp.21-29
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    • 2010
  • The concept of carrying capacity for bivalve culture of an area can be classified into four hierarchical categories, according to their level of complexity and scope, such as physical, production, ecological and social carrying capacity. Most scientific efforts to date have been directed towards modelling production carrying capacity and some of the resultant models have been used successfully. But, the modelling of ecological carrying capacity is still in its infancy, because it should consider the whole ecosystem and all culture activities. A more holistic approach is needed to determine the influence of bivalve aquaculture on the environment and ecological carrying capacity. As an alternative, we can use a set of ecological indicators which can show the environmental performance of bivalve farms and assess ecological carrying capacity. Clearance efficiency and filtration pressure indicators show the value of 0.331 and 0.203, respectively, and these indicators suggest that the present level of culture in GeojeHansan Bay is above the ecological carrying capacity of 0.05. Consequently, these indicators can provide a guidance on the present level of culture in regard to production and ecological carrying capacity in GeojeHansan Bay.