• Title/Summary/Keyword: Bending work

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Analysis and Improvement Methods of Unsafe Posture Associated with Various Agricultural Works

  • Jung, Hwa-Shik
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.4
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    • pp.473-480
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    • 2011
  • Objective: This paper presents the results of a literature review undertaken to analyze the types and risk factors of unsafe posture in accordance with the crops and the working position and to introduce various ergonomic intervention approaches. Background: There is clear and consistent evidence that agricultural work has been rated as one of the dangerous occupations in the world. A considerable number of adverse health conditions, including musculoskeletal disorders(MSDs) are related to agricultural work. Method: An agricultural work requires squatting, kneeling, and bending(stooping) postures for significant periods of the work day which due to a wide variety of activities such as planting, cultivating and harvesting various agricultural products. Thus, each of these postures is analyzed in detail to recommend the improvement methods. Results: Various unsafe postures in agricultural works are revealed and analyzed. It is proven that ergonomics intervention has the potential benefits to reduce MSDs among agricultural workers. Two types of ergonomic intervention methods were discussed to improve unsafe working postures, engineering controls and administrative controls. Conclusion & Application: As a concluding remark, this article can be used as a reference manual for the agricultural workers and also used to raise the research community's awareness to the risk of unsafe working postures for workers in agriculture.

Fracture Behavior of $Al_2O_3$ Macro-composites with Layered and Fibrous Structure (층상 및 섬유상 $Al_2O_3$ 거시복합체의 파괴거동)

  • 신동우;윤대현;박삼식;김해두
    • Journal of the Korean Ceramic Society
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    • v.34 no.7
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    • pp.758-766
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    • 1997
  • Non-brittle fracture behaviour of the two composite structures made of two different brittle materials was investigated using 3-point bending test. First, the layered and fibrous macro-composites were fabricated using the material easily formed, yet showing a brittle fracture behaviour similar to ceramics. The layered and fibrous Al2O3 /Al2O3 composites with weak interface were also fabricated using plate of 2 mm thickness and rod of 3 mm diameter respectively. Comparison of the mechanical properties between these two structures was performed in the lights of flexural strength and work of fracture for the composites consisting of Al2O3 and simulated materials respectively. The strength ratio of layered structure to the monolith of same volume was 0.6 and the ratio of fibrous one was about 0.2 for the composites made of simulated brittle material. The ratio of the work of fracture of the fibrous to the layered was 0.47. For Al2O3/Al2O3 composites, the strength ratio of layered and fibrous structures to the monolith with same volume were about 0.6 and 0.2 respectively. The ratio of work of fracture of the fibrous to the layered was 0.6. These confirmed that the layered structure was superior to the fibrous one in terms of flexural strength and work of fracture.

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Analysis of Working Posture for Construction Workers Using OWAS Method (OWAS 기법을 활용한 건설업 근로자의 작업 자세 분석)

  • Eom, Ran-i;Lee, Yejin
    • Fashion & Textile Research Journal
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    • v.20 no.6
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    • pp.704-712
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    • 2018
  • This study analyzed working postures using the Ovako Working Posture Analysis System (OWAS) to improve work clothes for construction workers. A video taken at a construction work site was stopped at regular intervals and the postures of relevant body parts proposed by OWAS was recorded. Additionally, based on analysis of the working postures code, the level of work action for each postures was classified from stage I to IV. General workers frequently straightened or bent forward at the waist, and used their legs to stand, bend, or walk. Wood workers moved extensively from the waist, keeping their legs relatively straight and their arms held below their shoulders, repeatedly tapping with a hammer weighing less than 10.0kg. Rebar bending workers mainly bent forward at the waist, with both legs bent or standing with one leg bent. Rebar transport and fixing workers walked with the waist straight, and occasionally one or both hands held above the shoulders. Their work also involved holding a hook, which weigh less than 10.0kg, in their hands, and the difficult task of lifting and placing long rebars, which weigh from 10.0 to 20.0kg or more. Concrete pouring workers bent or twisted their back to the side. Therefore, this study suggests that design goals should be different when developing workwear for each type of worker.

The Study of the Prevalence and Causes of Occurrence on Work-Related Musculoskeletal Disorders(WMSDs) in Physical Therapist (물리치료사의 직무관련 근골격계 통증의 유병률과 발생요인에 관한 연구)

  • Kwon, Won-An;Lee, Jae-Hong;Kim, So-Yeon;Lee, Young-Hwa
    • PNF and Movement
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    • v.10 no.3
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    • pp.19-23
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    • 2012
  • Purpose : The purpose of the present study was to describe the prevalence and causes of occurrence on work-related musculoskeletal disorders(WMSDs) in physical therapist. Methods : Self-administered questionnaires were distributed by mail to 100 physical therapists in Daegu city. 85 of the questionnaires were returned and 80 of them except 5 unclearly answered ones were analyzed. Results : They felt the pain at shoulders(80%), lower back(74%), wrists(71%), neck(70%), elbow(48%), finger(40%). The major causes of the pain were "repeating the same job constantly(93%)," and "bending wrists too much and doing things that require excessive strength(90%)." It was significant different more Exercise therapist than modality therapist. Conclusion : We suggest that physical therapist for exercise therapy need the development and applies of various program for prevention of work-related musculoskeletal disorders.

Improvement of Grommet Work Safety by Comparision of Domestic and Foreign Guidelines (국내외 지침 비교를 통한 Grommet 작업 안전성 향상 방안 연구)

  • Lee, Jin Woo;Han, Cheol Ho;Lee, Song Woo;Jeon, Young Hun;Lee, Chang Hee
    • Journal of the Korean Society of Safety
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    • v.37 no.4
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    • pp.63-72
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    • 2022
  • The number of deaths caused by power crane accidents continues to decline. Nevertheless, more than 50 people die each year due to these accidents. Various types of slings, such as wire rope sling, chain sling, belt sling, and grommet, are used in industries, depending on the characteristics of the work involved. To reduce the number of accidents involving these slings, the formulation of technical measures and education of workers are necessary. This study compares and analyzes local and international guidelines as well as those found in manufacturer manuals in relation to grommets, which are widely used in shipyards and construction sites. Moreover, measures for improving the safety of work using grommet are reviewed. This paper further proposes the revision of the technical guidelines of the Korea Occupational Safety and Health Agency such that the information directly affecting the safety of work involving grommets is included. By clarifying the guidelines that manufacturers provide in their manuals, accident prevention through worker awareness is anticipated in the future.

Application Technology and Implementation Method based on VR for Korean Beef Deborning Work (한우 발골 작업을 위한 가상현실 기반의 응용 기술과 구현 방법)

  • Sung-Jun Park
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.4
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    • pp.71-76
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    • 2024
  • In this paper, we propose a platform for learning deboning technology of Korean beef through vr-based experiential learning. The Korean beef deboning process is not only a food ingredient that has represented Korea for a long time, but also an object with high traditional cultural value. However, due to the hard and dangerous work envrionment of the deboning field, the number of skilled dobiners is gradually decreasing. This study proposes a platform that can train these deboning technicians in virtual reality and covers applied technologies used. In particular, we discussed how processes such as bending, opening, and cutting are implemented during meat cutting, which is a very important part of deboning work. In the experiment, cutting work was performed based on actual meat modeling, and complete cutting was tested.

신경회로망에 의한 로보트의 역 기구학 구현

  • 이경식;남광희
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.144-148
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    • 1989
  • We solve the inverse kinematics problems in robotics by employing a neural network. In the practical situation. it is not easy to obtain the exact inverse kinematics solution, since there are many unforeseen errors such as the shift of a robot base the link's bending, et c. Hence difficulties follow in the trajectory planning. With the neural network, it is possible to train the robot motion so that the robot follows the desired trajectory without errors even under the situation where the unexpected errors are involved. In this work, Back-Propagation rule is used as a learning method.

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Deducing thick plate solutions from classical thin plate solutions

  • Wang, C.M.
    • Structural Engineering and Mechanics
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    • v.11 no.1
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    • pp.89-104
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    • 2001
  • This paper reviews the author's work on the development of relationships between solutions of the Kirchhoff (classical thin) plate theory and the Mindlin (first order shear deformation) thick plate theory. The relationships for deflections, stress-resultants, buckling loads and natural frequencies enable one to obtain the Mindlin plate solutions from the well-known Kirchhoff plate solutions for the same problem without much tedious mathematics. Sample thick plate solutions, deduced from the relationships, are presented as benchmark solutions for researchers to use in checking their numerical thick plate solutions.

Resin Impregnation of Sawdust Board for Making Woodceramics (I) - Effect of Impregnation Method and Time on Physical and Mechanical Properties -

  • Oh, Seung-Won
    • Journal of the Korean Wood Science and Technology
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    • v.32 no.3
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    • pp.25-32
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    • 2004
  • This research work explored physical and mechanical properties of impregnated sawdust boards from three softwood species (P, densifora, L. kaemferi, and P. koraiensis) with phenol-formaldehyde (PF) resin by various vacuum treatment methods of combining pressure, vacuum, and ultrasonic waves. Simultaneous vacuum and ultrasonic wave treatments with no pressure resulted in the greatest increase in resin content, density, dimensional changes (thickness and length), bending strength, and hardness of impregnated board. This result seemed to be attributed to the ultrasonic wave treatment.