• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.91-94
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• 2006

Miniature BLDC is widely used in industrial applications and especially medical appliances because of there character that high driving efficiency and high torque characteristic. However torque ripple of a high speed miniature BLDC is serous in switching period cue to the very electrical time constant. This paper present instant voltage and current control for torque ripple reduction of a high speed miniature BLDC. Computer simulation and experiment test for 40,000 rpm miniature BLDC show the verification of the proposed control method.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.117-119
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• 2004

In order to successfully exploit underwater resources, the first step would be a marine environmental research and exploration on the seafloor. Traditionally one sets up a long-term underwater experimental unit on the seafloor and retrieves the unit later after a certain period time. Essential to these applications is the reliable teleoperation and telemetering of the unit. This study presents ultrasonic-wave remote control system and an underwater sound recognition algorithm that can identify the sound signal without the influence of disturbances due to underwater environmental changes. The proposed method provides a means suitable for units which require low power dissipation and long-time underwater operation. We demonstrate its ability of securing stability and fast sound recognition through experimental methods.

• KSBB Journal
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• v.8 no.5
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• pp.504-507
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• 1993

A declining tendency in embryogenic capability was seen during 6 months culture period during which embryo production decreased from 1000 embryos/ml to 500 embryos/ml. The presence of extracellular factors extracted from newly established embryo cultures restored the embryogenic capability and even enhanced the embryo production up to 5 times (2500 embryos/ml) for old carrot suspension cultures compared with that of control cultures. The stimulating effect on the embryo production indicates that the enhancing effect comes from extracellular compounds that are probably protein molecules.

• Journal of the Korean Home Economics Association
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• v.42 no.10 s.200
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• pp.143-152
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• 2004

This study presents the effects of serum lipids and blood glucose on retort Samgyetang intake in rats. For this purpose, we measured the ingredients and contents of Samgyetang, and produced a diet for experimental rats. The animal experiment was done in three different diet groups: control, Samgyetang(I) and Samgyetang(II). The results were as follows; 1) There was no sign of difference between the three groups in the body weight gain and food intake due to the effect of dietary component. 2) The density of serum triglyceride in the Samgyetang(II) group was decreased, but there was no sign of difference between the control group and Samgyetang(II). 3) There were no statistically significant differences of serum cholesterol and phospholipid among my of the diet groups. 4) The free fatty acid density and blood glucose level in the Samgyetang(I) and (II) groups were higher than in the control group. In the author's opinion, it is necessary to reexamine them for a long period through the animal experiment.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.116-121
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• 2013

The effects of oligosaccharide supplementation on the growth performance, flock uniformity and GIT development of broiler chickens were investigated. Four diets, one negative control, one positive control supplemented with zinc-bacitracin, and two test diets supplemented with mannoligosaccharide (MOS) and fructooligosaccharide (FOS), were used for the experiment. Birds given MOS or FOS had improved body weight (BW) and feed efficiency (FCR), compared to those fed the negative control diet during the 35-d trial period. The effect on FCR became less apparent when the birds got older. FOS and MOS supplementation reduced the pancreas weight as a percentage of BW, with an effect similar to that of the antibiotic, at 35 d of age. Birds given MOS tended to have a heavier bursa (p = 0.164) and lower spleen/bursa weight ratio (p = 0.102) at 35 d of age. MOS and Zn-bacitracin showed a clear improvement on flock uniformity, compared to FOS. The mortality rate was not affected by FOS or MOS.

• Journal of Korean Academy of Nursing
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• v.37 no.4
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• pp.510-518
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• 2007

Purpose: This study examined the effects of an insight-oriented nursing program on schizophrenic patients' insight, positive and negative syndromes, and depression. Method: A non-equivalent control group non-synchronized design was utilized. For this research, a total of 34 subjects were selected at a psychiatric hospital in Daegu during the period ranging from Oct. 1st, 2005 to Feb. 11th, 2006 (experimental group=17, control group=17). Result: After the treatment, between the experimental and control groups, there wasa significant difference in the level of SUMD(t=-4.52, p=.000) and positive syndrome(t=6.97, p=.013), but no significant difference in the negative syndrome(t=-1.81, p=.079) and depression(t=2.23, p=.145). Conclusion: The results of this study show that the insight-oriented nursing program works well for schizophrenic patients. Therefore, it is recommended that this program should be used in clinical practice as an effective nursing intervention for schizophrenic patients.

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.305-314
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• 2005

Injection rate shape control is one feature of a diesel fuel injection system that is strongly desired at this time. In the conventional common rail system, it is difficult to control the injection rate since the fuel pressure is constant during the injection period, resulting in a nearly rectangular rate shape. In order to look into possible injection modulations, injectors equipped with standard and geometrically modified control valves were investigated in detail by means of computer modelling and simulation. Experiments were carried out to validate the feasibility of such a shaping. The results of this study show a noteworthy dependence of the fuel rate on geometrical modifications in the piloting stage of the injector.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.1
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• pp.94-100
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• 2004

Most power steering systems obtain the power by a hydraulic mechanism. Therefore, it consumes more energy because the oil power should be sustained all the times. Recently, to solve this problem the electric power system has been developed and become widely equipped in passenger vehicles. In this research the simulation integration technique for an electric power steering system with MATLAB/SIMULINK and a full vehicle model with ADAMS has been developed. A full vehicle model interacted with electronic control unit algorithm is concurrently simulated with an impulsive steering wheel torque input. The dynamic responses of vehicle chassis and steering system are evaluated. This integrated method allows engineers to reduce the prototype testing cost and to shorten the developing period.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.197-198
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• 2011

A technique to manage harmonic pollution at the point of common coupling (PCC) has been presented using a control chart. The recursive least-squares technique has been used to estimate the parameters of the Thevenin equivalent load model. With the estimated data from the measured voltage and current waveform at the PCC during certain period violating upper control limit, the individual contributions to the distortion of voltage waveform at an interested harmonic frequency have been calculated and shown by simple graph.

• Journal of Environmental Health Sciences
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• v.30 no.1
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• pp.1-6
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• 2004

This study was performed to estimate the effects of washing of food wastes on temperature, pH, weight and volume reduction and salinity in aerobic composting of food wastes. Weight ratios of food wastes to water in washing were 1:0(Control), 1:1 (W-1), 1:2(W-2), 1:3(W-3) and :4(W-4), respectively. Ratios of food wastes to wood chips in reactor of Control, W-1, W-2, W-3 and W-4 were 5 kg:5 1, respectively. Reactors were operated for 24 days with 1 hour stirring by 1 rpm and 2 hours aeration per day. The increase in the ratio of food wastes to water used in washing resulted in the decrease of the highest reaction temperature and the elongation of the high temperature reaction period. The lowering of the ratio of food wastes to water used in washing resulted in faster pH increase and the steady state in the weight reduction rate and the volume reduction rate of composts. The final salinities of Control, W-1, W-2, W-3 and W-4 were 0.95%, 0.73％, 0.65%, 0.57％ and 0.41％, respectively.