• 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.

• Steel and Composite Structures
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• v.49 no.2
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• pp.125-141
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• 2023

Firstly, a new kind of prismatic tensegrity structures with redundant cables is defined, the topology, geometry and forming conditions of which are introduced further. The development of its mechanical properties including self-stress states and structural stiffness with the increment of the twist angle is also investigated carefully. Combined with the topology of this kind of structures, a reasonable erection scheme is proposed, in which some temporary lifting points need to be set and two groups of vertical cables are tensioned in batches. Then, a simplified dynamic relaxation method is employed to track the erection process inversely, which aims to predict each intermediate equilibrium state during the construction, and give the key structural parameters that can effectively guide the construction. The removal of the active cables, the relaxation or tension of the passive cables are simulated by controlling their axial stiffness, so that the structural composition as well as the serial numbers of the elements always keep invariant regardless of the withdrawal of the slack cables. The whole analysis process is clear in concept, simple to implement and easy to popularize. Finally, several examples are given to verify the practicability and effectiveness of the proposed method further.

• Journal of the Korean Society of Safety
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• v.22 no.4
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• pp.90-95
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• 2007

The objective of this study was to find the musculoskeletal stress problems at chicken farms in Korea. One typical chicken farm was surveyed in this study. NLE(NIOSH Lifting Equation), REBA(Rapid Entire Body Assessment), and OWAS(Ovako Working Analysis System) were used to evaluate the extent of the musculoskeletal stress. It was found that there were some tasks which required fast innovation. It was also found that the RWL (Recommended Weight of Lift) was 4.6Kg. that was lower than weights which were handled by these workers.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.44
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• pp.323-332
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• 1997

This study evaluated the compression force at the L5/S1 disc using EMG(Electromyography). EMG signals were analyzed under the condition of fixed vertical factor (20Cm∼80Cm), two horizontal factors (35Cm, 55Cm), and two weight factors (10Kg, 25Kg) 2 times per minute for each posture. Also, the result was compared with the compression force of each posture which computated by the equation of NIOSH(National Institute for Occupational Safety and Health) guide to manual lifting(1991). The experimental result show that EMG signals have more an effect on the Weight than the Horizontal factors. Also, there are not significant differences on the analysis result of EMG signals between Health members and not, because the body buildings which doing Health members are not enhanced the motor unit due to the MMH(Manual Material Handing).

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.07a
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• pp.77-82
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• 1999

현재까지 마늘 생산의 생력기계화 작업체계는 확립되어 있지 않으며, 특히 마늘의 수확은 많은 노동력을 필요로 하여 마늘 생산비에 수확비용이 차지하는 비중은 매우 높다. 따라서 마늘 수확의 생력화를 위해 마늘수확기 개발이 시급한 실정이다. 마늘수확기의 개발을 위해 분석, 구명되어야 할 중요한 인자는 수확기의 소모동력, 작업성능, 메커니즘의 간결성과 편리성, 수확효율 및 수확후 처리 등에 관계되는 모든 인자들이 포함된다. 나아가 마늘수확기에 고려되어야 할 주요 작동부는 동력발생부, 동력전달부, 마늘수확부 및 이송부, 마늘 수확을 위한 전처리부 및 후처리부, 마늘수확기 운행에 필요한 운전부 등으로 나눌 수 있다. (중략)

• Journal of computational fluids engineering
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• v.8 no.4
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• pp.26-33
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• 2003

Smart UAV Development Program, one of the 21c Frontier R&D Program sponsored by MOST(Ministry of Science and Technology), was launched in 2002 As an air vehicle for the Smart UAV, CRW(Canard Rotor/wing) concept was one of the candidates compared in trade-off study. The CRW concept has not only been proven completely but its aerodynamic characteristics not known in detail yet. Two calculation methods were adopted in this study to obtain aerodynamic data for the CRW First method was the superpose DATCOM method which is capable of three lifting sufaces, and second one is the full Navier-Stokes computation around CRW configuration using overset grid method. Basic aerodynamic characteristics of the CRW configuration was analyzed and the minimum drag level with lift to drag ratio is presented. The peculiar flow characteristics around rotor/wing and hub were also examined and considered in the configuration design.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.458-463
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• 2011

A CHS(Container Handling System) is a system to load and to unload ISO 2000 or ISO 4000 standard containers which is widely used for various industrial transport purpose. A new light type of CHS is introduced in this paper, in order to reduce weight of cargos and to give the convenience in cargo loading and unloading without additional lifting equipments. The structural models of this system are created to assemble the smooth integration of system and to interface the each composing units with the specification of truck chassis to be mounted. These models are applied to find the suitable design parameters under the condition of force restrictions of each units. Finally, the stability of this system are investigated by analyzing the dynamic simulation using Visual NASTRAN 4D, and it could be recommend the good design parameters for the manufacturing purpose.

• The Journal of Engineering Geology
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• v.7 no.1
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• pp.1-10
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• 1997

The construction of Kyungbu canal connecting Han and Naktong rivers is needed to facilitate the carriage of goods and enhance the economic growth. The two rivers are liflked by the Choryeong tunnel with 20.5 km length and 125 m altitude. Seven locks involving of 25 m lifting height are planned to reach the tunnel from Shingok dam along the Han river. The tunnel and dams are located favorably by topographic and geologic map analysis. The water needed to fill the chamber of high lock will he supplied by construction of additional dams above Chungju-dam and/or intmduction of water-saving lock system.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.1044-1047
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• 2011

본 연구는 소방대원의 현장 작업자세 평가와 분석을 통하여 소방대원의 근골격계 부담작업 유해요인을 분석하고자 한다. B시에 소재하고 있는 소방서의 남자 소방대원을 대상으로 소방 현장에서 많이하는 자세 중 요구조자 이송작업자세, 방수작업자세, 유압구조장비 작업자세, 만능도끼작업 자세를 인간공학적 평가 기법인 Rapid Entire Body Assessment(REBA), Rapid Upper Limb Assessment(RULA)와 NIOSH Lifting Equation(NLE)를 이용하여 평가하고 분석하였다. 자세 분석결과, RULA 분석에서 모든 작업이 최고 점수인 7점으로 평가되었고 REBA는 5점에서 10점까지로 RULA분석에 비하여 낮은 점수를 나타내었다. 따라서, 소방대원들의 작업환경과 자세에 문제가 많다는 것을 알 수 있었다.

• 한국기계연구소 소보
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• v.4 no.2
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• pp.49-63
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• 1982

In this paper, a classical gust problem is treated by using the numerical lifting¬-surface theory to verify the effect of gust-a sudden fluctuating fluid velocity around an object, which is normal to the main stream direction-on the hydrody¬namic forces, especially the mean thrust in upstream direction, acting on the two¬-dimensional flat plate. In this case, the mean thrust wholly resorts to the leading edge suction, and it is the same situation to the case of the heaving plate in uniform flow. The ph¬enomenon of leading edge suction is very important for the flapping propulsion of animals, typical to fish and birds, and can be related to the prediction of the hydrodynamic forces acting on marine propellers operating in gustlike wakes of ships. The results of this paper can be easily superposed to those of the reference [1J in order to solve the problem of the two-dimensional oscillacting plate in gust