• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.458-465
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• 2000

Although Fly ash possess viable engineering properties, an overwhelming majority of the fly ash from coal combustion is still placed in storage or disposal sites. Similarly, sludges generated from various water treatment operations are predominantly subject to the fate of land disposal. To prepare sludges for land disposal typically requires time consuming dewatering schemes, which can become extremely difficult to execute dependent upon the composition of the sludge and its affinity for water. This test was undertaken to reuse of fly ash and sludge with mix. In this paper includes of geotechnical properties of fly ash and fly ash-sludge mixture and results of compaction test, unconfined test, falling head test and CBR test and it was analyzed the effect on mixing fly ash with sludge.

• Journal of Korea Association of Health Promotion
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• v.3 no.2
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• pp.147-164
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• 2005

The purpose of this study was to examine the effects of physical activity on women's health. I conducted literature reviews for meta-analyses and randomized controlled trials with the target diseases including cardiovascular diseases, diabetes, cancers osteoporosis, and pregnancy outcomes. Women who were active had less total mortality and smaller incidence of hypertension, coronary heart diseases, and stroke. Exercise was better than drug therapies in preventing diabetes and effective in preventing colon and breast cancers. Exercise can reduce the risks of falling injury in elderly women. Walking during pregnancy was not harmful to the mothers and their infants, and desirable to prevent the complications of pregnancy or weight gain after pregnancy. Physical activity at work and leisure-time showed similar effects on women's health. Based on these results, moderate-intensity physical activity should be recommended to all women, Resistive, muscle strength, and balance-training exercise also can be recommended. Doctors' advices are effective to make women exercise, especially using handouts or motivational interviewing techniques. It is desirable to recommend to peform other health promotion measures together such as smoking cessation, weight control and diet control.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.663-668
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• 1997

In Korea, the temperature of winter seasons are really severe and cause lot's of snow-falling and iceing in the pavements. Several de-iceing mehtod have generally been adopted to melt the ice on the surface of pavement. Therefore, the Study of experimental in the first stage was given to the verification of the icers's effects. First, Contrete and asphalt pavement specimens were made and scattered with a CaC2-deicers. then 3cm and 5cm thickness of artificial snow were prepared on the surface of specimens. It reveals that the early calorification due to de- icers as high as the temperature of laboratory increases within about 10 minutes and last for more then 2 hours and the test of ice-formation on the surface of contrete and asphalt specimen due to snow leads to the similar rate of freezing time about 20 minutes. Second, three kinds of de-icers, such as CaC2 CaC2+Nacl, Cacl Flaket are rested in the snowy highway to check the iceing-resistance. The CaC2 is proved to be the most effective de-icers so far.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.57-60
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• 2005

This study discusses spalling and fire enduring performance of high performance concrete (HPC) RC column subjected to loading under heating for 3 hours. According to the test, both the plain concrete and the concrete attached with fire enduring PC panel exceed allowable temperature after 60 minutes due to the exposure of steel bar and falling off of concrete resulting from severe spalling failure. It leads to buckling of main bar and at the same time, occurrence of collapse of plain HPC column member is observed after 2 hours and 1 hour 40 minutes's exposure to fire, respectively. On the other hand, HPC applying both PP fiber of 0.1$\%$ by mass of concrete and PP fiber+lateral confinement by metal lath maintains their original cross section, which is satisfied with the 3 hours fire endurance criteria, by discharging internal vapour pressure and enhanced lateral confinement force.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.69.3-70
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• 2016

We study the orbital histories of Virgo galaxies undergoing different HI gas stripping stages using phase-space diagrams. Based on the HI properties of galaxies, we find that location of galaxies is in good agreement with ram-pressure stripping predicted by numerical simulations with different infall time. For example, galaxies experiencing active gas stripping are mostly found in the first infall region showing high velocity with respect to the cluster center. Meanwhile, most galaxies that are likely to have lost gas a while ago are found in the cluster outskirts with low orbital velocities. We also discuss the cases where observational properties of galaxies and their locations in the phase-space do not well agree. In addition, we probe the phase-space of filaments and subgroups around or within Virgo. Our results strongly suggest that substructures can play important roles in galaxy evolution while galaxies are falling to the cluster.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.562-564
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• 2005

This paper presents the reasonable design parameters of a SRM for hybrid electric vehicle driving. For the design of SRM, the initial model is designed using the equivalent magnetic circuit method. In order to optimize the SRM for HEV. The initial model is redesigned by FEM with the variation of the stock length and turns of winding. This paper shows that a flat-topped current of a phase can be made from a change of the stack length and the number of turns for high efficiency, high average torque and a lower torque ripple. The change of current falling time as a variation of turn-off angle was shown by FEA. The iron loss and copper loss were described. The torque of the redesigned motor is suitable for low and high speed ranges to drive a HEV that was verified by the speed-torque curve.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.96-98
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• 2005

Proposed Multi-level PDP sustain Driver make use of element which has a low voltage rating instead of suggested method by the existing Webber and it passes through a second phase both rising and falling at sustaining voltage waveform In accordance with the change of timing phase(Tr1, Ti1, Tr2) performance comparison of a electric discharge characteristics in a PDP module has been carried out. At the conclusion of experimentation, the feature is extended by alteration of Ti1 and it has little to do with alteration of Tr1.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.46
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• pp.93-101
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• 1998

A great number of firms have used overall equipments effectiveness index to evaluate the effect of TPM activities. Overall equipments effectiveness is very useful index to emphasize the need of decreasing equipments loss time when TPM system is first implemented. And it is powerful to evaluate prductivity growth rate according to TPM activities when GNP growth rate is high level. However, during the depression period, the increase of overall equipments effectiveness does not contribute fully to the cost down, the reason is that demand is falling. In this paper, we present the rectified TPM activities which can be applied to the depression period, and analysis the improvement activities of production part how to contribute to the cost down,

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.8
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• pp.358-363
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• 2005

This paper presents the reasonable design parameters of a switched reluctance motor to drive a hybrid electric vehicle by using the equivalent magnetic circuit method. The designed motor can be redesigned by using finite element analysis as a variation of the parameter for the purpose of improving performance. This paper shows that a flat-topped current of a phase can be made from a change of the lamination stack length for high average torque and a lower torque ripple. The change of current falling time as a variation of turn-off angle was shown by finite element analysis. The core loss and copper loss were described. The torque of the redesigned motor is suitable for low and high speed ranges to drive a HEV. which is verified by the speed-torque curve.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.460-463
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• 1993

In this paper, The laser transmitter module is designed as the subsystem of the high repetitive laser rangefinder. The module consists of high voltage power supply, high voltage control circuits, high voltage discharger, electro-optic Q-switch driver, and laser resonator. The high voltage power supply is composed of 2-phase flyback converter. And it has 220W power level and 78% conversion efficiency. From the Q-switch driver of the crossed porro resonator, the phase retardation voltage is switched from 600V to -1500V with 200ns falling time. The module can be operated up to 15Hz. And it generates the laser pulse which has 20ns width and 80mJ.