• Korean Journal of Computational Design and Engineering
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• v.15 no.5
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• pp.383-392
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• 2010

The purpose of this study is to develop three Judo-doll systems for enhancement of Judo's performance. Traditional Judo training requires a human training partner. Unfortunately it is not always easy to find one. Multifunctional Judo-doll training system has therefore been developed, and is described here. The system consists of a dummy, a power generating mechanism, and kinematic links. The power-generating mechanism generates forces similar to those of a human, by adjusting deadweights and controlling powderbrake's forces. The powderbrake force is controlled by the microprocessor according to the exercise scenario. The kinetic links, which mimic a human training partner's motions, has been developed based on a $Vicon^{TM}$ system's analysis of the movement of human training partners. This mechanism whose name is "L link-wire" consists of L type links, wire, roller, and dead weight. This mechanism generates the force that leads the link to the neutral position regardless the link is pushed or pulled. The lifting mechanism that lifts the doll when the one-armed shoulder throw skill is applied is also developed. A 32-bit microprocessor controls the whole system; it reads the loadcell data, controls the electromagnetic force, and communicates with a PC via Bluetooth. The training history, including loadcell data, date, and training time, is stored in the PC for analysis. This training system can be used to enhance the Judo performance of any self training player.

• Journal of Biosystems Engineering
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• v.35 no.1
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• pp.31-36
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• 2010

A small unmanned helicopter was suggested to replace the conventional spray system. Aerial application using an agricultural helicopter helps precise and timely spraying, and reduces labor intensity and environmental pollution. In this research, a rotor system (SW05) was developed and its lift capability was evaluated. Lift force for the dead weight of the helicopter was obtained at the grip pitch angle of $12^{\circ}$. As the pitch angle increased to $14^{\circ}$ and $16^{\circ}$, the payload increased to 176 N and 216 N, respectively. Compared with SW04 airfoil performance in the total lift, the SW05 airfoil showed nearly the same capacity, but the payload of the SW05 was reduced because of the increased dead weight. A rated flight condition was defined as lifting mean payload of 294 N with the grip pitch angles of $16{\sim}17^{\circ}$ at the rotor rotating speed of 850~950 rpm for the adjusted engine power. The fuel consumption would be 4.8~6.0 L/hr, and the air temperature of cooling fan should be kept below $160^{\circ}C$.

• The Journal of Korean Medicine
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• v.33 no.1
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• pp.136-147
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• 2012

Objectives: The purpose of this study was to evaluate work-related risk factors of musculoskeletal disorders (MSDs) in various departments and tasks at an oriental medicine hospital. Methods: 269 hospital workers were selected for the study. The questionnaire survey included general characteristics, work-related characteristics and MSDs. Cross-tabulation analysis, multiple logistic regression, adjusted for age, work time, job demand and workload, were used to evaluate the effects of work-related factors on MSDs. Results: There were differences in MSDs depending on gender, age, occupation, and work-related factors. Prevalence rates of MSDs were 23.79% shoulder, 14.13% back, 10.41% neck. Risk factors for MSDs was packaging of drugs, transfer, and exercise therapy of physical therapist. Shoulder pain was significantly influenced by using power tools, over-reaching, and job demand while back pain was significantly influenced by weight-lifting operations and keyboard typing. Conclusions: The results of this study suggest that consideration of MSDs characteristics of workers in oriental medicine hospital is necessary to change unsuitable work environments and educate on preventing MSDs.

• Journal of Korean Physical Therapy Science
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• v.9 no.2
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• pp.133-141
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• 2002

This purpose of this study was to design the effect of recovering of a hand amputees by Myoelectronic hand. It was designed with 2 degree of freedom in the laboratory. Myoelectronic hand had only one degree of freedom and one movement until now. Also this myoelectronic hand had multi-joint and it could move widely. Wire was used in transmission. Myoelectronic hand data was obtained by analyzing hand anatomically and measuring and that data was applied when it was designed. PID controller of Myoelectronic hand was used to it. Displacement control was applied the first link. Experiment was accomplished in Tip grasp, Power grasp and Hook grasp modes. Displacement control was good in low frequency. Velocity control was applied to each mode. The objective of the study was to develop more better multifunction myoelectronic control strategies. A myoelectronic hand with a hand amputees could do some jobs such as grasping materials, lifting weighting, holding cup and etc. As a result of this study, all subjects with hand amputees significantly improved in ADL. Further studies were needed to evaluate the effect of a myoelectronic hand with more precise laboratory equipment.

• Ocean and Polar Research
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• v.36 no.4
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• pp.455-463
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• 2014

This paper presents data from performance tests carried out to assess a manganese nodule crusher. Manganese nodules should be crushed into smaller pieces in order to assure the slurry flow of the lifting system. Both artificial nodules and real manganese nodules are used to evaluate nodule breaking ability of the crusher. The crushing performance of the crusher depends on the flow rate and pressure of the power transmission device. The size of the crushed manganese nodules also depends on the shape of the crushing drum. In this paper, several comparative tests are carried out to evaluate and improve the crushing performance and find the optimal design point of the crusher.

• The KSFM Journal of Fluid Machinery
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• v.14 no.5
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• pp.12-17
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• 2011

The seawater lift pump system is responsible for maintaining the open canal level to provide the suction flow of circulating water pump at the set point. The objective of this paper is to design a 2-stage mixed flow pump (for seawater lifting) by inverse design method and to evaluate the overall performance and the local flow fields of the pump by using a commercial CFD code. Rotating speed of the impeller is 1,750 rpm with the flow rate of 2,700 $m^3$/h. Finite volume method with structured mesh and realized k-${\varepsilon}$ turbulent model is used to guaranty more accurate prediction of turbulent flow in the pump impeller. The numerical results such as static head, brake horse power and efficiency of the mixed flow pump are compared with the design data. The simulated results are good agreement with the design data less 3% error.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.556-560
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• 2011

The seawater lift pump system is responsible for maintaining the open canal level to provide the suction flow of circulating water pump at the set point. The objective of this paper is to design a 2-stage mixed flow pump(for seawater lifting) by inverse design and to evaluate the overall performance and the local flow fields of the pump by using a commercial CFD code. Rotating speed of the impeller is 1,750 rpm with the flow rate of 2,700 $m^3/h$. Finite volume method with structured mesh and Realizable ${\kappa}-{\varepsilon}$ turbulent model is used to guaranty more accurate prediction of turbulent flow in the pump impeller. The numerical results such as static head brake horse power and efficiency of the mixed flow pump are compared with the reference data. Also, the periodic condition calculation method for the mixed flow pump was carried out in order to investigate the pump performance characteristics with the modification of impeller geometry.

• Journal of Drive and Control
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• v.12 no.4
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• pp.35-40
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• 2015

A gas spring provides support force for lifting, positioning, lowering, and counterbalancing weights. It offers a wide range of reaction force with a flat force characteristic, simple mounting, compact size, speed controlled damping, and cushioned end motion. The most common usage is as a support on a horizontally hinged automotive tail gate. However, its versatility and ease of use has been applied in many other industrial applications ranging from office equipment to off-road vehicles. The cylinder of a gas spring is filled with compressed nitrogen gas, which is applied with equal pressure on both sides of the piston. The surface area of the rod side of the piston is smaller than the opposite side, producing a pushing force. The magnitude of the reaction force is determined by the cross-sectional area of the piston rod and the internal pressure inside the cylinder. The reaction force is influenced by many design parameters such as initial chamber volume, diameter ratio, etc. In this paper, we investigated the reaction force characteristics and carried out parameter sensitivity analysis for the design parameters of a gas spring.

• Journal of Drive and Control
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• v.15 no.4
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• pp.17-22
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• 2018

Mobile hydraulics require higher energy efficiency, and a simpler as well as robust design, than general industrial hydraulics. The 6/3-way directional control valve is widely used as a mobile hydraulic control valve. However, since the 6/3-way directional control valve is a spool type valve, it is difficult to maintain the load. A counterbalance valve is typically used, to maintain the load, and lift down. However, in an industrial field using a mobile hydraulics device, a pilot controlled check valve may be used to implement holding and lifting operation of the self-weight load, and a relief valve may be used simply to exert back pressure. But no comparative analysis of advantages and disadvantages of each method was revealed. In this study, various methods of holding and unloading load with self-weight in mobile hydraulics are investigated, and compared through simulation using AMESim software. This is experimentally verified by using Festo's mobile hydraulic test rig TP800.

• Journal of Korean Gerontological Nursing
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• v.20 no.3
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• pp.204-216
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• 2018

Purpose: The purpose of this study was to examine effects of a muscle strength reinforcement exercise program (MSREP) for older adult patients with hemodialysis (OAPHD) which was designed to improve health status and quality of life of these older adult patients. Methods: Participants were 40 patients with OAPHD: 20 in the experimental group and 20 in the control group. MSREP was conducted with the experimental group for 12 weeks at H geriatric hospital. An assessment was done to determine effects on physical performance, inflammation index, fatigue, muscle strength and quality of life. Short physical performance battery, C-Reactive Protein (CRP), visual analog scale for fatigue, object lifting' proposed by the Life Options Rehabilitation Advisory Council, sit-to-stand test, and quality of life index were used to gather data. Results: Between the 2 groups there was no significant difference in scores for physical performance, fatigue or quality of life. However, the 2 groups showed significant difference in CRP values and muscle power scores on post-test. Conclusion: Findings provide evidence for the potential utility of education for older adult patients with hemodialysis. Also, this program could allow these patients to increase muscle strength, and contribute to achieving better health conditions in OAPHD care.