• Title/Summary/Keyword: Joint Energy

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The Planning Techniques and Layout Models of Sustainable Rural Villages (환경친화.자원절약형 농촌마을 계획기술 및 배치모델 연구)

  • Im, Seung-Bin;Shin, Ji-Hoon;Yun, Hee-Jeong
    • Journal of Korean Society of Rural Planning
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    • v.9 no.1 s.18
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    • pp.1-9
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    • 2003
  • This study intends to select the planning techniques and develop the layouts of environmentally friendly rural villages. As the results of this study, the planning techniques of rural villages are as follows: (1) Development of agricultural technology(organic farming), (2) Environmentally friendly layout considering natural energy, conservation of natural landscape and ecosystem, and sewage and rainwater, (3) Community restoration considering joint work, economic interchange between urban people and rural residents, and unity of rural resident's opinion, and (4) Activation of rural tourism considering satisfaction of tourists, conservation of ecological and cultural resources, and resident's income increasement. According to these 4 techniques, this study also developed 4 general models: (1) land-use and flow, (2) green and blue networks, (3) networks of ecological and cultural resources, and (4) finally residential model, divided rural villages into 2 types. Therefore when we develop a countryside, we can apply to these models, considering the current ecological and cultural resources conditions.

The Effect of Attention Focusing Strategies on the Speed and Segment Coordination Characteristics of Taekwondo Hand Techniques (주의초점 전략이 태권도 기본동작의 속도 및 분절 협응패턴에 미치는 효과)

  • Kang, Sungchul;Kim, Kitae
    • Korean Journal of Applied Biomechanics
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    • v.24 no.3
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    • pp.229-238
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    • 2014
  • This study comparatively analyzed the speed and segment coordination characteristics of Taekwondo hand techniques, while different attention focusing strategies were utilized. Ten elite Taekwondo poomsae athletes participated, and three different strategies (no focus, target focus, body focus) were utilized in random order. The hand velocity and upper body segment coordination characteristics were analyzed, with the following results. First, the maximum magnitudes of the hand velocity differed between the focus conditions for the Araenaereomakgi and Momtongjireugi techniques. Second, the angular velocity and kinetic energy transfer patterns of the segments differed between the focus conditions, and in the case of the body focus condition, the movement was more correct according to the theory. Third, the shoulder and elbow joint coordination patterns differed between the focus conditions, with more efficient movement shown with the body focus condition. In conclusion, we confirmed the potential of effectively using an attention focusing strategy in a taekwondo teaching situation. However, the effect on the movement coordination and results of the movement could be changed by a difference in the cue provided or the type of the task. In addition, depending on the task, the attention focusing strategy could affect the efficiency of the movement. Therefore, coaches and masters of Taekwondo will have to constitute determine the appropriate attention focusing cues based on the task.

Radurization and Radicidation of Spices (향신료(香辛料)의 방사선조사(放射線照射) 살균(殺菌))

  • Byun, Myung-Woo
    • Korean Journal of Food Science and Technology
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    • v.17 no.4
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    • pp.311-318
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    • 1985
  • This review was intended to develop the sterilization method of spices by gamma irradiation and the results are summarized as follows. Microbial load of spices was different according to the kind of spices and the number was ranged from $10^{2}$-$10^{5}/g$ to $10^{7}$-$10^{8}/g$, gamma irradiation up to 4-10 kGy could decreased or sterilized to the microorganism of spices. In physicochemical properties of spices such as chemical components,essential oil and flavor, irradiated group with optimum dose was almost similar to the nonirradiated one, while fumigant treated group was remarkably deteriorated in the properties of spices compared with control, and free radicals produced by irradiation was disappeared during a few days storage. Irradiated spices should be an aptitude for good quality the storeability of processing food. Optimum dose irradiation below less than that proposed by FAO/IAEA/WHO Joint Committee and FDA was remarkably effect on the sterilization of spices and superior in wholesomeness and economic feasibiity compared with traditional methods. Irradiation might be an alternative to traditional sterilization methods of spices by fumigants such as ethylene oxide and ethylene dibromide because their treatments have been banned in U.S.A and other countries since 1982.

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Study of a Gravity Compensator for the Lower Body (중력보상기 기반의 하지용 외골격 장치 설계 연구)

  • Choi, Hyeung-Sik;Kim, Dong-Ho;Jeon, Ji-Kwang
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.4
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    • pp.455-462
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    • 2011
  • This paper is about the design of a new gravity compensator for the lower body exo-skeleton device. The exo-skeleton devices is for increasing the torque of the human body joint for the purpose of helping the disabled, workers in the industry, and military soldiers. So far, most of studied exo-skeleton devices are actuated by the motors, but motors are limited in energy such that a short durability is always a big problem. In this paper, a new gravity compensator is proposed to reduce the torque load applied to human body joints due to gravity. The gravity compensator is designed using a tortional bar spring, and its structure and characteristics are studied through the test and computer simulation. A design concept on the exo-skeleton device using the gravity compensator is presented. An analysis and computer simulation on the torque reduction of the proposed exo-skeleton device that applies and non-applies the gravity compensator are performed.

Force and Pose control for Anthropomorphic Robotic Hand with Redundancy (여유자유도를 가지는 인간형 로봇 손의 자세 및 힘 제어)

  • Yee, Gun Kyu;Kim, Yong Bum;Kim, Anna;Kang, Gitae;Choi, Hyouk Ryeol
    • The Journal of Korea Robotics Society
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    • v.10 no.4
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    • pp.179-185
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    • 2015
  • The versatility of a human hand is what the researchers eager to mimic. As one of the attempt, the redundant degree of freedom in the human hand is considered. However, in the force domain the redundant joint causes a control issue. To solve this problem, the force control method for a redundant robotic hand which is similar to the human is proposed. First, the redundancy of the human hand is analyzed. Then, to resolve the redundancy in force domain, the artificial minimum energy point is specified and the restoring force is used to control the configuration of the finger other than the force in a null space. Finally, the method is verified experimentally with a commercial robot hand, called Allegro Hand with a force/torque sensor.

Calculation of Iron Loss under Rotational Magnetic Field Using Finite Element Method (회전 자계에 의한 철손의 유한요소 해석)

  • Lee, H.Y.;Park, G.S.;Hahn, S.Y.
    • Proceedings of the KIEE Conference
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    • 1994.07a
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    • pp.147-149
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    • 1994
  • In designing high efficiency electrical machines, calculation of iron loss is very important. And it is reported that in the induction motor and in the T-joint of 3 phase transformer, there occurred rotational magnetic field and much iron loss is generated owing to this field. In this paper, rotational power loss in the electrical machine under rotational magnetic field is discussed. Until now, loss analysis is based on the magnetic properties under alternating field. And with this one dimensional magnetic propertis, it is difficult to express iron loss under rotational field. In this paper, we used two dimensional magnetic property data for the numerical calculation of rotational power loss. We used finite element method for calculation and the analysis model is two dimensional magnetic property measurement system. We used permeability tensor instead of scalar permeability to present two dimensional magnetic properties. And in this case, we cannot uniquely define energy functional because of the asymmetry of the permeability tensor, so Galerkin method is used for finite element analysis.

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Effectiveness of some conventional seismic retrofitting techniques for bare and infilled R/C frames

  • Kakaletsis, D.J.;David, K.N.;Karayannis, C.G.
    • Structural Engineering and Mechanics
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    • v.39 no.4
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    • pp.499-520
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    • 2011
  • The effectiveness of a technique for the repair of reinforced concrete members in combination with a technique for the repair of masonry walls of infilled frames, damaged due to cyclic loading, is experimentally investigated. Three single - story, one - bay, 1/3 - scale frame specimens are tested under cyclic horizontal loading, up to a drift level of 4%. One bare frame and two infilled frames with weak and strong infills, respectively, have been tasted. Specimens have spirals as shear reinforcement. The applied repair technique is mainly based on the use of thin epoxy resin infused under pressure into the crack system of the damaged RC joint bodies, the use of a polymer modified cement mortar with or without a fiberglass reinforcing mesh for the damaged infill masonry walls and the use of CFRP plates to the surfaces of the damaged structural RC members, as external reinforcement. Specimens after repair, were retested in the same way. Conclusions concerning the effectiveness of the applied repair technique, based on maximum cycles load, loading stiffness, and hysteretic energy absorption capabilities of the tested specimens, are drawn and commented upon.

Investigation of torsion, warping and distortion of large container ships

  • Senjanovic, Ivo;Vladimir, Nikola;Tomic, Marko
    • Ocean Systems Engineering
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    • v.1 no.1
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    • pp.73-93
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    • 2011
  • Large deck openings of ultra large container ships reduce their torsional stiffness considerably and hydroelastic analysis for reliable structural design becomes an imperative. In the early design stage the beam model coupled with 3D hydrodynamic model is a rational choice. The modal superposition method is ordinary used for solving this complex problem. The advanced thin-walled girder theory, with shear influence on both bending and torsion, is applied for calculation of dry natural modes. It is shown that relatively short engine room structure of large container ships behaves as the open hold structure with increased torsional stiffness due to deck effect. Warping discontinuity at the joint of the closed and open segments is compensated by induced distortion. The effective torsional stiffness parameters based on an energy balance approach are determined. Estimation of distortion of transverse bulkheads, as a result of torsion and warping, is given. The procedure is illustrated in the case of a ship-like pontoon and checked by 3D FEM analysis. The obtained results encourage incorporation of the modified beam model of the short engine room structure in general beam model of ship hull for the need of hydroelastic analysis, where only the first few natural modes are of interest.

A Review of Pressure Tube Failure Accident in the CANDU Reactor and Methods for Improving Reactor Performance

  • Yoo, Ho-Sik;Chung, Jin-Gon
    • Nuclear Engineering and Technology
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    • v.30 no.3
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    • pp.262-272
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    • 1998
  • The experiences and causes of pressure tube cracking accidents in the CANDU reactors and the development of the fuel channel at AECL(Atomic Energy Canada Limited) have been described. Most of the accidents were caused by Delayed Hydride Cracking(DHC). In the cases of the Pickering units 3&4 and the Bruce unit 2, excessive residual stresses induced by an improper rolled joint process played a role in DHC. In the Pickering unit 2, cracks formed by contact between the pressure and calandria tubes due to the movement of the garter spring were the direct cause of the failure. To extend the life of a fuel channel, several R&D programs examining each component of the fuel channel have been carried out in Canada. For a pressure tube, the main concern is focused on changing the fabrication processes, e.g., increasing cold working rate, conducting intermediate annealing and adding a third element like Fe, V, and Cr to the tube material. In addition to them, chromium plating on the end fitting and increasing wall thickness at both ends of the calandria tube are considered. There has also been much interest in the improvement of fuel channel performance in our country and several development programs are currently under way.

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3D FEM Analysis of Warm Forging Process Design for Socket at Automotive Steering Unit (자동차 조향장치용 소???R의 온간단조 공정 설계를 위한 3차원 유한요소해석)

  • Lee Y. S.;Lee J. H.;Lee J. Y.;Bae M. H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.05a
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    • pp.186-189
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    • 2001
  • In keeping with the needs of the times for energy and labor saving and simplifying production processes, interests has been growing in warm forging. Moreover, it is interested in increasing the material usage and production amounts. To improve the productivity and material usage, it is studied the process design of warm forging for socket. Until now, socket is manufactured by hot forging in hammer. The percentage of material usage is under $60\%$ in hammer forging. On the other han4 the percentage can be increased over $90\%$ in warm forging. To change the process from hot forging to warm forging, process designs must be performed. In this time, by using the FEM package, DEFORM-3D, we could get the shape of 1st process and minimum sealing pressure. They are very essential design data to decrease the trial and error. Practically, the overlap defect could be detected and eliminated with design modification of rib height and fillet radius. Moreover, forging load and minimum sealing pressure was defined by the 3D FEM analysis.

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