• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.69-78
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• 2002

This paper examines the effects on mental fatigue of changes in the intensity of physical activity. A treadmill-equipped instrument and perception tester were used to attain several levels of physical activity In this paper, In order to determine the individual levels of physical activity of subjects, Borg-RPE scale, Heart Rate(HR) and Respiratory Quotient(RQ) were used. Also, an addition test in whole-body activity on treadmill-equipped instrument as an indicator of mental fatigue were performed. In the above experiments, the scores obtained in addition test administered before and after physical activity at each intensity level used. Restricted within the limits of this paper, the results of these tests showed that mental fatigue decreased after physical activity.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.203-205
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• 2006

This paper presents a study on the winding method and structure of core of single phase induction motor in order to design the high efficiency motor. In case of single phase induction motor, winding fill factor and the number of turns in each slot are not uniform in general. Moreover, these can be the critical parameters for high efficiency design in case the size of motor should be restricted within certain volume. Therefore, we should analyze the effects of these parameters related to efficiency parameter. The characteristic analysis was performed by using FEM.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.3
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• pp.262-267
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• 2007

Detection of gas leak from a tube is a very important issue in the quality control of machines such as the heat exchanger of an air-conditioner, because leakage of operating gas directly reduces the performance of machines. The acoustic emission (AE) method is a common way to detect leak of gas, however its application under the environment of mechanical vibration is restricted since most AE detectors are very sensitive to external vibration noise. In order to overcome this problem, we propose a method based on the mode analysis of the Lamb wave. In this method, the dominant Lamb mode and its frequency are found first, and then a proper band-pass filter is used to retain only this frequency component. In this way, we could improve the SNR (signal-to-noise ratio) of AE signal generated by gas leak from the tube even under vibratory environment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1247-1252
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• 2007

The machine equipment of the building inside occurs the vibration. In order to reduce this vibration spring, rubber pad is used. But efficiency of this classical mount is restricted at specific frequency. Also maximum efficiency design is complicated. This paper proposes and examines a attached mass isolation system that is used to reduce transmitted vibrations from machines onto their floor support. With attached mass the low frequency performance is improved overall. The performance is showed in 2 degree of freedom model test. And the proposed isolator has been validated by dynamic test and good agreement between theoretical and experimental results has been obtained.

• The Journal of Korean Physical Therapy
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• v.14 no.1
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• pp.109-115
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• 2002

This study conducts eccentric exercise ti non-dominant elbow flexor of 20 persons in order to examine the effects of transcutaneous electric nerve stimulation on sympathetic nerve activity in delayed onset muscle soreness, induces delayed onset muscle soreness, divides them into 10 persons respectively as experimental and control groups. And a stimulation for 2 min. with 100 pps is given to elbow flexor after repeated three times of 10 minutes rest, temperature, blood pressure and pulse are measured and as a result of two-way ANOVA, change of temperature didn't show a significant difference according to the elapse of times(p>0.05) and systolic pressure and pulses in showed a significant difference between experimental and control groups(p<0.05). These results suggest that transcutaneous electrical nerve stimulation has a direct or indirect influence on sympathetic nerve activity in delayed onset muscle soreness under a restricted condition of electrical stimulation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.164-167
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• 2003

Profile ring rolling process is simulated by using the general purpose commercial finite element analysis software MSC.Superform Because the deforming region is restricted to the vicinity of the roll gap, only a ring segment spanning the roll gap is analysed in order to save computation time and cost. A profile ring with an external round groove is chosen as an example to be analysed. The rolls with and without groove were analysed to compare the amount of side spread. It is found that the grooves in the rolls reduce the amount of side spread.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.3
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• pp.63-79
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• 1994

Many vehicle fleet planning systems have been suggested to minimize the routing distances of vehicles or reduce the transportation cost. But the more considerations the method takes, the higher complexites are involved in a large number of practical situations. The purpose of this paper is to vehicle fleet planning system. This paper is considered multi-objective optimization. The vehicle fleet planning system developed by this study involves such complicated and restricted conditions as one depot, multiple nodes (demand points), multiple vehicle types, multipel order items, and other many restrictions for operating vehicles. The proposed algorithm is compared with the nearest neighbor heuristic (NNH) and the savings heuristic (SAH) algorithm in terms of total logistics cost and driving time. This method constructs a route with a minimum number of vehicles for a given demand. This method can be used to any companys which vehicle fleet planning system under circumstances considered in this paper.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.846-849
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• 2004

It is important to decide the precise chloride diffusion coefficient in order to predict the durability plan of concrete structure chloride and prediction of remaining lifetime. However, the inland references are limited to the rapid test in laboratory. The purpose of this study is to examine and analyze the established data, which are restricted by chloride diffusion coefficient, and to examine the prediction of the concrete structure durability by an FEM interpretation and the chloride diffusion coefficient as a variable.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.115-119
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• 2007

In this paper, practical problems will be covered in applying preview control to real tracked vehicle systems. Previous researches about the preview control assume that the vehicle speed is constant and the actuators have full frequency bandwidth. However, in order to apply it to real systems, those should be taken into account. Therefore this paper show the algorithm to apply the preview control to speed changing vehicles and performance variation according to a restricted frequency bandwidth.

• The Korean Journal of Food And Nutrition
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• v.9 no.2
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• pp.176-180
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• 1996

In order to develop new bioactive functions ginseng extract, it was studies whether the ginseng extracts on the induction of immunological tolerance In mice. Oral immunologic tolerance was induced by the secondary exposure of egg albumin + alum following gastrointestinal exposure nth egg albumin In mice, and the effect on anti EA antibody in blood, 7 cell subset in spleen were Investigated. The results obtained were as follows. EA group and EA + GE group was capable of conferring tolerance, contained a profound for 5 weeks experimental but saline group restricted to induce tolerance. GE group did not show the activity of tolerance by the first immunogens exposure, but induced the tolerance by the secondary exposure. And also spleen T cells, CD 8+ and CD 4+ were decreased. These results suggested that ginseng may affect the induction of immunological tolerance, which may be associated proliferative response of CD 4+ and CD 8+ in splenocyte.