• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.63-72
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• 2017

This paper proposes a procedure to improve the operational efficiency of the automotive parts manufacturing process by applying classical IE techniques composed of process analysis, work method analysis, and motion analysis, and a specific application case is outlined. The proposed procedure was developed originally by the Task Force organized in L company's automotive parts manufacturing business unit. The balance efficiency and production capacity were used as measures of operational efficiency. The developed procedure follows the general procedure of analyzing the phenomenon at the manufacturing shop, deriving an improvement solution to solve the problem, evaluating each derived alternative, and implementing it to the field to achieve productivity improvement. Among the methods used in each phase of the procedure, function analysis used in the waste discovery phase and R&R evaluation method used in the alternative assessment phase are unique techniques developed by L company's TF. The R&R Evaluation method techniques are described in detail because this method is highly applicable and extensible. A case of applying developed procedures to improve the EPS motor manufacturing process is discussed. As a result, the line balance efficiency and production capacity were increased to a satisfactory level.

• Korean journal of applied entomology
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• v.19 no.4 s.45
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• pp.212-220
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• 1980

The purpose of this study is to establish a standard amount of pesticide per unit area of the lumber over the sea level. This establishment is required in applying the sea water dipping disinfection method to the imported soft woods to control the pests living on the surface of the lumber. The major findings of this study are as follows; 1. The average length and diameter of the imported soft wood was respectively 11.12m and 76.46Cm. 2. The average cubic content of the lumber over the sea level to the whole cubic content was 20.82 percent. 3. The ratio of the lumber over the sea level to the whole cubic content was 2.3356 at the $95\%$ significance level. 4. The sampling error of the ratio of the area of the lumber over the sea level to the cubic content was lower in the case of the pieces of lumber in a vessel than the average between ten tressels. 5. The optimum amount of pesticide spray per $1\;M^2$ of the soft wood was 0.298 cc in the case of using the hand spray, but 0.245 cc the motor spray. 6. For example, in the case of applying the sea water dipping disinfection method to the 5,000 $M^3$ of the imported soft wood, the required amount of pesticide with a motor spray can be estimated as follow. $$5,000\;M^3\times2.333=11,678\;M^2$$ $$11,678M^2\times0.295=3,445cc$$.

• The Journal of Internal Korean Medicine
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• v.19 no.1
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• pp.57-72
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• 1998

This study has been carried out to investigate the effects of Ukgansan(UGS) extract on anti-convulsive, antipyretic, analgesic, sedative and GABAergic system of experimental animals. The results of this study were as follows : 1. UGS extract prolonged significantly the beginning time to convulsion and death induced by strychnine. 2. UGS extract prolonged significantly the time to death induced by electrical shock of ECT unit.(3 sec, 200 F, 25 mA) 3. On the experiment of hypothermic effects of UGS extract on the rectal temperature of mouse, UGS extract decreased significantly the rectal temperature of mouse 4. On the experiment of antipyretic effects of UGS extract on the febrile induced by the subcutaneous injection of $150\;{\mu}g/kg$ endotoxin in mouse, UGS extract decreased significantly the rectal temperature of mouse. 5. On the experiment of analgesic effects of UGS extract on the writhing syndrome induced by intraperitoneal injection 0.7% acetic acid 1 ml/100g in mouse, the writhing syndrome induced by acetic acid was reduced significantly by administration of UGS extract. 6. On the experiment of effects of UGS extract on spontaneous motor activity measured by wheel cage method in mice, the spontaneous motor activity was reduced significantly by administration of UGS extract. 7. On the experiment of effects of UGS extract on the activity of GABA-transaminase(GABA-T) in mouse brains after 21 days of oral administration of UGS extract. the activity of GABA-T was reduced significantly by administration of UGS extract. 8. On the experiment of effects of UGS extract on the activity concentration of GABA in mouse brain after 21 days of oral administration of UGS extract, the activity concentration of GABA was reduced significantly by administration of UGS extract. 9 On the experiment of effect of UGS water extract on the activity of GAD in mouse brain after 21 days of oral administration of UGS extract, the activity of GAD was reduced significantly by administration of UGS extract. According to the these results, Ukgansan extracts reveal the effects on the anti-convulsive, antipyretic, analgesic, sedative and GABAergic system.

• Korean Journal of Oriental Medicine
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• v.2 no.1
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• pp.205-225
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• 1996

This study has been carried out to investigate the effects of Youngyanggaksan (YGS) extract on the anticonvulsive, antipyretic, anlgesic, sedative and GABAergic system of experimental animals. The results of this study were as follows : 1. YGS extract prolonged significantly the beginning time to convulsion and time to death induced by strychnine. 2. YGS extract prolonged significantly the time to death induced by electrical shock of ECT unit (3sec, 200F, 25mA). 3. On the experiment of hypothermic effects of YGS extract on the rectal temperature of rats, YGS extract decreased significantly the rectal temperature of rats. 4. On the experiment of antipyretic effects of YGS extract on the febrile induced by the subcutaneous injection of $150{\mu}g/kg$ endotoxin in rats, YGS extract decreased significantly the rectal temperature of rats. 5. On the experiment of analgesic effects of YGS extract on the writhing syndrome induced by intraperitoneal injection 0.7% acetic acid 1ml/100g in rats, the writhing syndrome was reduced significantly by administration of YGS extract. 6. On the experiment of sedative effects of YGS extract on spontaneous motor activity measured by wheel cage method in mice, the spontaneous motor activity was reduced significantly by administration of YGS extract. 7. On the experiment of effects of YGS extract on the activity of GABA-transaminase(GABA-T) in rat brains after 21 days of oral administration of YGS extract, the activity of GABA-T was reduced significantly by administration of YGS extract. 8. On the experiment of effects of YGS extract on the activity concentration of GABA in rat brains after 21 days of oral administration of YGS extract the activity concentration of GABA was reduced significantly by administration of YGS extract. 9. On the experiment of effects of YGS extract on the activity of GAD in rat brains after 21 days of oral adminstration of YGS extract, the activity of GAD was reduced significantly by administration of YGS extract. According to the those results, Youngyanggaksan extract reveals the effects on the anticonvulsive, antipyretic, anlgesic, sedative and GABAergic system.

• Journal of Power Electronics
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• v.11 no.4
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• pp.408-417
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• 2011

The plug-in hybrid electric vehicles (PHEVs) are specialized hybrid electric vehicles that have the potential to obtain enough energy for average daily commuting from batteries. The PHEV battery would be recharged from the power grid at home or at work and would thus allow for a reduction in the overall fuel consumption. This paper proposes an integrated power electronics interface for PHEVs, which consists of a novel Eight-Switch Inverter (ESI) and an interleaved DC/DC converter, in order to reduce the cost, the mass and the size of the power electronics unit (PEU) with high performance at any operating mode. In the proposed configuration, a novel Eight-Switch Inverter (ESI) is able to function as a bidirectional single-phase AC/DC battery charger/ vehicle to grid (V2G) and to transfer electrical energy between the DC-link (connected to the battery) and the electric traction system as DC/AC inverter. In addition, a bidirectional-interleaved DC/DC converter with dual-loop controller is proposed for interfacing the ESI to a low-voltage battery pack in order to minimize the ripple of the battery current and to improve the efficiency of the DC system with lower inductor size. To validate the performance of the proposed configuration, the indirect field-oriented control (IFOC) based on particle swarm optimization (PSO) is proposed to optimize the efficiency of the AC drive system in PHEVs. The maximum efficiency of the motor is obtained by the evaluation of optimal rotor flux at any operating point, where the PSO is applied to evaluate the optimal flux. Moreover, an improved AC/DC controller based Proportional-Resonant Control (PRC) is proposed in order to reduce the THD of the input current in charger/V2G modes. The proposed configuration is analyzed and its performance is validated using simulated results obtained in MATLAB/ SIMULINK. Furthermore, it is experimentally validated with results obtained from the prototypes that have been developed and built in the laboratory based on TMS320F2808 DSP.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.118-124
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• 2011

To reach the Euro-6 regulations of PM and $NO_x$ for light-duty diesel vehicles, it will be necessary to apply the CDPF and the de-$NO_x$ catalyst. The described system consists of a catalytic configuration, where the CDPF is placed downstream of the diesel engine and followed by a urea injection unit and a urea-SCR catalyst. One of the advantages of this system configuration is that, in this way, the SCR catalyst is protected from PM, and both white PM and deposits become reduced. In the urea-SCR system, the injection control of reductant is the most important thing in order to have good performance of $NO_x$ reduction. The ideal ratio of $NH_3$ molecules to $NO_x$ molecules is 1:1 based on $NH_3$ consumption and having $NH_3$ available for reaction of all of the exhaust $NO_x$. However, under the too low and too high temperature condition, the $NO_x$ reduction efficiency become slower, due to temperature window of SCR catalyst. And space velocity also affects to $NO_x$ conversion efficiency. In this paper, rig-tests were performed to evaluate the effects of $NO_x$ and $NH_3$ concentrations, gas temperature and space velocity on the $NO_x$ conversion efficiency of the urea-SCR system. And vehicle test was performed to verify control strategy of reductatnt injection. The developed control strategy of reductant injection was improved over all $NO_x$ reduction efficiency and $NH_3$ consumption in urea-SCR system. Results of this paper contribute to develop urea-SCR system for light-duty vehicles to meet Euro-5 emission regulations.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.2
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• pp.21-32
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• 2013

This is a preliminary study for the real-time feedback vibration control of building structures. The study developed a wireless acceleration sensor system based on authentic technology capacities, to integrate with the Prototype AMD system and ultimately construct the feedback vibration control system. These systems were used to evaluate the basic performance levels of the control systems within model building structures. For this purpose, the study first developed a wireless acceleration sensor unit that integrates an MEMS sensor device and bluetooth communication module. Also, the study developed an operating program that enables control output based on real-time acceleration response measurement and control law. Furthermore, the Prototype AMD and motor driver system were constructed to be maneuvered by the AC servo-motor. Eventually, all these compositions were used to evaluate the real-time feedback vibration control system of a 2-story model building, and qualitatively measure the extent of vibrational reduction of the target structure within the laboratory validation tests. As a result of the tests, there was a definite vibrational reduction effect within the laboratory validation tests. As a result of the tests, there was a definite vibrational reduction effect within 1st and 2nd resonance frequency as well as the random frequency of the model building structure. Ultimately, this study confirmed the potential of its wireless acceleration sensor system and AMD system as an effective tool that can be applied to the active vibration control of other structures.

• The Journal of Internal Korean Medicine
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• v.18 no.2
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• pp.65-82
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• 1997

This study has been carried out to investigate the effects of Cheonmagudeungyeum(CGY) extract on anti-convulsive, antipyretic, analgesic, sedative and GABAergic system of experimental animals. The results of this study were as follows : 1. CGY extract prolonged significantly the beginning time to convulsion and death induced by strychnine. 2. CGY extract prolonged significantly the time to death induced by electrical shock of ECT unit(3 sec, 200 F, 25 mA) 3. On the experiment of hypothermic effects of CGY extract on the rectal temperature of mice, CGY extract decreased the rectal temperature of mice. 4. On the experiment of antipyretic effects of CGY extract on the febrile induced by the subcutaneous injection of $150\;{\mu}g/kg$ endotoxin in mice, CGY extract decreased significantly the rectal temperature of mice. 5. On the experiment of analgesic effects of CGY extract on the writhing syndrome induced by intraperitoneal injection 0.7% acetic acid 1 ml/100g in mice, the writhing syndrome induced by acetic acid was reduced significantly by administration of CGY extract. 6. On the experiment of effects of CGY extract on spontaneous motor activity measured by wheel cage method in mice, the spontaneous motor activity was reduced significantly by administration of CGY extract 7. On the experiment of effects of CGY extract on the activity of GABA - transaminase (GABA-T) in mouse brains after 21 days of oral administration of CGY extract, the activity of GABA-T was reduced significantly by administration of CGY extract. 8. On the experiment of effects of CGY extract on the activity concentration of GABA in mouse brain after 21 days of oral administration of CGY extract, the activity concentration of GABA was reduced significantly by administration of CGY extract. 9. On the experiment of effect of CGY water extract on the activity of GAD in mouse brain after 21 days of oral administration of CGY extract, the activity of GAD was reduced significantly by administration of CGY extract. According to the these results, Cheonmagudeungyeum extracts reveal the effects on the anti-convulsive, antipyretic, analgesic, sedative and GABAergic system.

• Journal of Korean Society of Transportation
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• v.32 no.1
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• pp.1-12
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• 2014

The tier 3 methodology used in estimation of greenhouse gas emissions from road sectors is based on mileage data. However, such data can neither accurately represent the mileage of regional unit nor have sufficient integrated data reflecting the characteristics by region, vehicle type, fuel type and road type. Such estimation of greenhouse gas emissions is not reliable. Accordingly, the purpose of this study is, firstly to accumulate activity data based on distance traveled which enables us to accurately estimate the amount of green gas emitted by regional unit(emission point), and secondly, to develop a methodology for estimation of greenhouse gas emissions using these data. To do this, the study utilizes the mileage data of Korea Transportation Safety Authority(TS), statistics of registered motor vehicles, statistical yearbook of traffic volume from the Ministry of Land, Infrastructure and Transport(MLIT), the Korea Transport Database of the Korea Transport Institute(KOTI), and average road speed by local government. Methodology for estimation by local government level(emission point) is meaningful, because it reflects traffic pattern data including flow in and out and internal traffics. Finally, to verify the methodology presented in this study, it is applied to Seoul. Both greenhouse gas estimates, one by multiplying the average mileage and the number of registered vehicles and the other by multiplying traffic volume and road extension, are less than the amount estimated by the methodology presented in this study.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.11
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• pp.979-986
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• 2016

The tripod shafts of constant-velocity joint are used in both the trains KTX and KTX-sanchon. It is an important component that connects the motor reduction unit and the axle reduction unit in a power bogie. The tripod shaft not only transmits drive and brake torque in the rotational direction, but also slides in the axial direction. If the drive system is loaded with an excessive torque, the fuse part of the shaft will be fractured firstly to protect the other important components. In this study, a rig was developed for conducting torsion tests on the tripod shaft, which is a type of mechanical fuse. The tripod shafts were subjected to torsional fracture test and torsional fatigue test on the rig. The weak zone of the tripod shaft was identified, and its fatigue life was predicted using finite element analysis (FEA). After analyzing the FEA results, design solutions were proposed to improve the strength and fatigue life of the tripod shaft. Furthermore, the deterioration trend and time for failure of the tripod shaft were verified using the hysteresis loops which had been changed with the advancement of the torsional fatigue test.