• Clinics in Shoulder and Elbow
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• v.17 no.2
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• pp.57-63
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• 2014

Background: To compare the effect of different starting periods of rehabilitative exercise (early or delayed passive exercise) on the rate of retear and other clinical outcomes after the arthroscopic repair of the rotator cuff. Methods: In total, 103 patients who underwent arthroscopic repair of the rotator cuff were included in the study. Determined at 2 weeks post-operation, patients who were incapable of passive forward elevation greater than $90^{\circ}$ were allotted to the early exercise group (group I: 79 patients; 42 males, 37 females), whilst those capable were allotted to the delayed exercise group (group II: 24 patients; 14 males, 10 females). The group I started passive exercise, i.e. stretching, within 2 weeks of operation, whilst group II started within 6 weeks. The results were compared on average 15.8 months (11-49 months) post-operation using the passive range of motion, the Visual Analog Scale (VAS) pain score, and the University of California at Los Angeles (UCLA) and Constant scores. Stiffness was defined as passive forward elevation or external rotation of less than $30^{\circ}C$ compared to the contralateral side. Follow-up magnetic resonance imaging (MRI) was carried out on average 1 year post-operation and the rate of retear was compared with Sugaya's criteria. Results: There were no differences between the two groups in gender, age, smoking, presence of diabetes, arm dominance, period of tear unattended, pre-operative range of motion, shape and size of tear, degree of tendon retraction, and tendon quality. There were no significant differences in clinical outcomes. Whilst stiffness was more frequent in group II (p-value 0.03), retear was more frequent in group I (p-value 0.028) according to the MRI follow-up. Conclusions: During rehabilitation after the arthroscopic repair of the rotator cuff, the delay of passive exercise seems to decrease the rate of retear but increase the risk of stiffness.

• Journal of Electrochemical Science and Technology
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• v.10 no.4
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• pp.381-386
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• 2019

Zn-air battery uses oxygen from the air, and hence, air holes in it are kept open for cell operation. Therefore, loss of water by evaporation through the holes is inevitable. When the water is depleted, the battery ceases to operate. There are two water consumption routes in Zn-air batteries, namely, active path (electrolysis) and passive path (evaporation and corrosion). Water loss by the active path (electrolysis) is much faster than that by the passive path during the early stage of the cycles. The mass change by the active path slows after 10 h. In contrast, the passive path is largely constant, becoming the main mass loss path after 10 h. The active path contributes to two-thirds of the electrolyte consumption in 24 h of cell operation in 4.0 M KOH. Although water is an important component for the cell, water vapor does not influence the cell operation unless the water is nearly depleted. However, high oxygen concentration favors the discharge reaction at the cathode.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.113-115
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• 2008

At the high speed operation, the high demagnetization voltage can reduce the negative torque, so the output power and efficiency can be improved. In this paper, a novel power converter for single phase SRM with high demagnetization voltage is proposed. A simple passive capacitor circuit is added in the front-end, which consists of three diodes and one capacitor. Based on this passive network, the two capacitors can be connected in series and parallel, so the phase winding of SRM obtains general do-link voltage in excitation mode and the double dc-link voltage in demagnetization mode. The operation modes of the proposed converter are analyzed in detail. Some computer simulation results is done to verify the performance of proposed converter.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.676-682
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• 2019

After the Fukushima Daiichi accident, there has been an increasing preference for passive safety features in the nuclear power industry. Some passive safety systems require limited active components to trigger subsequent passive operation. Under very serious accident conditions, passive safety features could be rendered inoperable or damaged. This study evaluates (i) the performance and effectiveness of the passive safety features of iPOWER (innovative Power Reactor), and (ii) whether a severe accident condition could be reached if the passive safety systems are damaged, namely the case of heat exchanger tube rupture. Analysis results show that the reactor coolant system remains in the hot shutdown condition without operator actions or electricity for over 72 h when the passive auxiliary feedwater systems (PAFSs) are operable without damage. However, heat exchanger tube rupture in the PAFS leads to core damage after about 18 h. Such results demonstrate that, to enhance the safety of iPOWER, maintaining the integrity of the PAFS is critical, and therefore additional protections for PAFS are necessary. To improve the reliability of iPOWER, additional battery sets are necessary for the passive safety systems using limited active components for accident mitigation under such extreme circumstances.

• Journal of the Korean Electrochemical Society
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• v.6 no.1
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• pp.23-27
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• 2003

In this study investigations have been carried out for the evaluation of small DMFCS under passive operation conditions for use in portable powers. Under passive conditions, a maximum performance was obtained at a methanol concentration of 4 M and at a catalyst loading of $8mg/cm^2$ on both electrodes. By optimizing various parameters, we could achieve the highest performance of $55mW/cm^2$ at 1 attn and at R.T.A monopolar stack consisting of 6 unit cells with active area of $4.5cm^2/cell$ was prepared and it showed a uniform voltage distribution all over the cells and it had a power output of 1 watt and a power density of $37mW/cm^2$ A monopolar stack which consisted of 16 cells and produced a 2.4W power was also fabricated and was tested for operation of a miniature car.

• Journal of the Korean Society of Safety
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• v.10 no.2
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• pp.72-76
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• 1995

An electrostatic passive neutralizer without HV power source has been used widely to reduce charges on insulators such as running plastic films, papers and cloths, but its elimination characteristics and safely have been hardly investigated in detail. Especially, an operation of the passive neutralizer depends primarily on the charged insulator and the elimination ability does not depend on only the neutralizer, because an electrostatic elimination is caused by corona discharges occurring between the passive neutralizer and charged insulator. From a reason described above, the purpose of this study is to examine experimentally the elimination ability of the passive neutralizer. Experiments were made on the corona discharges between the passive neutralizer and charged insulator running at high velocity in practical field to make clear the setting condition of the passive neutralizer for operating effectively and safely. Results obtained from field experiments are presented in this paper.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.89-91
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• 2007

In this paper, we developed DSP based control system to automatically open and close passive filter, which is used to reduce harmonics, according to operating condition of loads. Passive filter control system automatically open and close each branch of filter according to working conditions of loads by sending signals to open and close installation of passive filter after measuring and monitoring voltage, current, harmonics, reactive power, power factor and so on. We verified it's performance by connecting control system with passive filter in the power line using the 100[HP] d.c. motor drive, opening and closing passive filter according to operation condition of motor, and measuring harmonics and reactive power, etc.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.514-519
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• 1997

The MRX is an integral type ship reactor with 100 MWt power, which is designed by Japan Atomic Energy Research Institute. It is characterized by integral type PWR, in-vessel type control roe drive mechanism, water-filled containment vessel and passive decay heat removal system. Marine reactor should have high passive safety. Therefore, in this study, we simulated the loss of flow accident to verify the passive decay heat removal by natural circulation using RETRAN-03 code. auxiliary feed water systems are used for decay heat removal mechanism and results are compared with the loss of flow accident analysis using emergency decay heat removal system by JAERI. Results are very similar to case of EDRS 1 loop operation in JAERI analysis and decay heat is successfully removed by natural circulation.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.859-864
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• 1998

Compact and small size, reliable and failsafe operation and low cost featuring fault current limiter causing the designer to take a close look into the use of passive fault current limiter(FCL) for the protection of power semiconductor devices in power electronic systems. This paper has identified the main parameters responsible for the development of ideal passive magnetic current limiter. The effect of those parameters on the range of operation and the voltage-current characteristics of the magnetic current limiter has been studied using tableau approach. Desirable characteristics are discussed and the simulation results are presented.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.352-355
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• 2003

27 passive systems in 21 mines constructed by The Coal Industry Promotion Board since 1996 were investigated to evaluate the treatment efficiency of systems and find problems in each system, which will eventually lead to the improvement or suggesting the alternative method of the passive treatment system. Problems in operation include overflow, leakage, inefficiency and unusablness. The efficiency of systems which has been evaluated by metal(Fe) removal rate and/or by acidity removal rate do not reflect the poor removal rate of S $O_4$$^{2-}$. Especially high concentration of S $O_4$$^{2-}$ and high COD in the beginning of the operation would decrease the bacteria activity due to the lack of the nutrition. To solve the problem of overflow the upflow-type SAPS is being considered.