• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.4
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• pp.161-161
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• 2003

The applications of SRM(Switched Reluctance motor) are dramatically increasing due to a simple mechanical structure, a high efficiency and a high speed drive characteristics. Energy recovery in the regenerative region is very important when SRM is used in traction drive. This is to reduce energy loss during mechanical braking and/or to have a high efficiency drive. To control excitation voltage during motoring and regenerating voltage in the generator operation in the SRM, multi-level voltage control is effective. This paper suggests multi-level inverter which is useful for motoring and regenerative operation. The proposed method is verified through simulations and experiments.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.326-332
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• 2018

In this paper, the design process and the control method of the power conversion system (PCS) that consists of a bidirectional DC-DC converter and a 3-level T-type inverter for an energy storage system is presented. Especially the design method of the output LCL filter for a 3-lvel T-type inverter without complex mathematical process are proposed. The validity of the control method and design process in this paper are verified through simulation and experimental analysis.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.86.5-86
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• 2001

This work describes a design and implementation of the level & flow rate control system by using a single-chip microcontroller. The proposed model system is designed based on the use of the single-chip microcontroller 8031 with the EPROM emulator for programming the computer software. The microcontroller reaches the input level and flow signals from the level sensor and the turbine flowmeter, respectively, via the signal conditioning circuits and A/D converters in order to calculate the control signal. Moreover, the status of the process variable can easily be set up and controlled by program monitoring through the emulator, and can be graphically displayed on the computer screen. Experiment results were carried out which can be ...

• The Journal of Korean Medicine
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• v.25 no.2
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• pp.194-206
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• 2004

Objectives : JiaoTeng-Yuan(교등원) is said to be a prescription for preservation of health in $\ulcorner$HuaTuo.ZhongZangJing (화타.중장경)$\lrcorner$. It is known to have the effect of Bu-Shen (보신: strengthening kidney) and Yi-Shou (익수: prolonging the span of one's life). This study investigates whether JTY is effective on inhibition of oxidation stress. Methods : Sprague-Dawley rats (12-week-old, weight $300{\pm}20g$) were divided into 3 groups. The normal group (n=8) was injected with PBS (1ml/body, s.c) subcutaneously behind the neck. The control group (n=8) was injected with D-galactose (50mg/kg, 1ml PBS/body, s.c) to induce pathological animals. The JTY group was injected with the same treatment as the control group, and fed containing JTY (10%). All groups were treated 1 time per day for 6 weeks. After the rats were sacrificed anti-oxidant enzyme (SOD, CAT, G-px) activity, GSH quantity of RBC and tissue (heart, liver and kidney), and plasma Vit-C quantity were examined. Also, the MDA levels of liver and kidney, lipofuscin of heart and endurance of erythrocyte membrane were measured. Results : In the JTY group, RBC's SOD activity decline was halted by 21 % of the normal level, compared to the control group, G-px activity (unit/g of Hb) increased significantly, compared to the normal group, and the level of Vit-C in plasma increased by 16%. Heart's SOD activity was kept at the same level as that of the normal group; and CAT activity decline was halted by 26%. Kidney's CAT and G-px activities were kept at the same level as that shown in the normal group, implying the existence of a halting effect. Liver also showed a slight halting effect against the decline of anti-oxidant ability, but the effect was not significant (${\alpha}=0.05$). A comparison between the levels of peroxide in SD rats showed that the level of TBARS in plasma increased significantly in the control group and that it was normal in the JTY group. The livers in the JTY group, compared to those in the control group, showed 36% halting effect of the normal level while their kidney's indicated the level significantly lower than the normal level. Heart's lipofuscin increased significantly in the control group, but was alike in both the JTY and the normal groups. Endurance of erythrocyte membrane (%) decreased significantly in the control group while it was kept at the similar level in both the JTY and the normal groups, indicating the halting effect. Conclusions : This study suggests that JTY is effective to defend oxidation stress caused by D-galactose in the animals. It showed that the anti-oxidant ability was maintained and strengthened. On the other hand, it reduced the level of peroxide in animals. In sum, JTY appeared to have the equilibrium normal physiological function in SD rat.

• Journal of Power Electronics
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• v.18 no.6
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• pp.1791-1804
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• 2018

To achieve a fast dynamic response and to solve the multi-objective control problems of the output currents, capacitor voltages and system constraints, this paper proposes a deadbeat and hierarchical predictive control with space-vector modulation (DB-HPC-SVM) for five-level nested neutral point piloted (NNPP) converters. First, deadbeat control (DBC) is adopted to track the reference currents by calculating the deadbeat reference voltage vector (DB-RVV). After that, all of the candidate switching sequences that synthesize the DB-RVV are obtained by using the fast SVM principle. Furthermore, according to the redundancies of the switch combination and switching sequence, a hierarchical model predictive control (MPC) is presented to select the optimal switch combination (OSC) and optimal switching sequence (OSS). The proposed DB-HPC-SVM maintains the advantages of DBC and SVM, such as fast dynamic response, zero steady-state error and fixed switching frequency, and combines the characteristics of MPC, such as multi-objective control and simple inclusion of constraints. Finally, comparative simulation and experimental results of a five-level NNPP converter verify the correctness of the proposed DB-HPC-SVM.

• The Journal of the Korean life insurance medical association
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• v.30 no.2
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• pp.16-19
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• 2011

In patents with diabetes, the higher the serum glucose level was, the more cardiovascular events and death were observed. But with a certain kind of group, to control glucose level tightly does not decrease the incidence of these events. Several studies show that intensive glucose control does not gain benefit in patient with long standing, uncontrolled diabetes, especially having previous cardiovascular events, while definitely preventing progression of newly onset of diabetic nephropathy. Whether intensive glucose control increases mortality in high risk group is obscure and needs more studies with longer observation time.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.115-120
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• 1993

It is difficult to establish a mathematical furnace model and automatic-fumace control because of the difficulty in direct measurement of the inner condition of a blast furnace. To solve this problem, we has developed and actually operated a blast furnace operation control system using artificial intelligence tool to be applied to the blast furnace process computer system. Since this system has a function of automatic Treat level control, higher practicality has been proved than the previous guidance-level expert system. This paper introduces an outline of the system and the result of application.

• Journal of the Korean Society of Food Culture
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• v.19 no.3
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• pp.326-335
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• 2004

The purpose of this study was to investigate the changes of food habits and anxiety level of obese children on body weight control program. The body weight control program included nutrition education, psychotherapy and exercise for weekly session during 9 months. The results from this study were as follows. A total of 27 obese children(boys 44.4%, girls 55.6%) participated in this study. The average age of children was 11.7 years, average height and weight were 141.7cm and 48.1kg respectively. $R{\ddot{o}}hrer$ index(RI) of children was significantly decreased from 167 to 163(p<0.001) and BMI was significantly decreased from 24.5 to 23.9 (p<0.01) after body weight control program. This study also found obesity index(OI) was significantly decreased from 133% to 128%(p<0.01) of 18 children after program. There was not significant difference in food habits score but frequency of overeating, and eating frequency of meats were significantly decreased(p<0.05) after body weight control program. Also depression score significantly decreased after body weight control program(p<0.001) and there was significant negative correlation(r=-0.552) between food habits and anxiety level. The factors analysis of anxiety items indicated that children had feelings more calm and sate after program(p<0.05). Therefore continuous and practical nutritional education and psychotherapy to change food habits and anxiety level are necessary to decrease child obesity. These results suggest that body weight control program including nutrition education, exercise and psychotherapy may be effective physiological and psychological body health of obese children.

• Journal of the Korean Society of Food Culture
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• v.20 no.4
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• pp.476-486
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• 2005

The purpose of this study was to investigate the effects of eating habits and control of overeating of obese children on the body weight control program. The program included nutritional education, psychotherapy and physical exercise on weekly session for 9 months. The results of this study were as follows. Participants of the study involved 30 obese children attending elementary school. The average age of the children was 11.78 years, mean height and weight were 146.22cm and 50.61kg. The average BMI and body fat contents were 24.06 and 30.49% respectively and WHR of the children was 0.87. There was a significant difference between boys and girls' BMI(25.18, 23.31, p<0.01). As a result of the eating habits test, 50% of the subjects showed low level of regularity of diet, and 76.7% of the subjects showed high level of balanced diet score. Large portion(83.3%) of the subjects had high level of healthy behavior score. WHR of girls significantly decreased from 0.86 to 0.82(p<0.01) after the body weight control program. There were no significant differences in serum components of the obese children after the program. When regarding the score of eating habits in relation to obesity indices, the WHR significantly decreased(p<0.05) in a group of children with high eating habits score. Also in the group of overeating controls, significantly decreased WHR(p<0.05). In the results of correlation analysis, body weight was positively correlated with BMI(r=0.624), the level of total cholesterol(r=0.5109) and HDL cholesterol(r=0.5088). The score of healthy behavior was positively correlated with height(r=0.5286) and negatively correlated with the level of LDL cholesterol(r=0.3555) and WHR(r=0.4028) These results suggest that the body weight control program must be considerate of the different groups of children with different scores in the eating habits and overeating controls test.

• The Journal of Pediatrics of Korean Medicine
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• v.20 no.1
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• pp.165-180
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• 2006

Objective : This study has been carried out to understand the effect of several herbal medicine concentrated solution on the hyperglycemic mice Induced with streptozotocin(STZ). Methods : The 60 mg/kg of STZ injection into mice twice by 24 h interval and then 120 mg/kg of STZ injection again 3 days after the earlier injection. Control group was subjected to natural recovery, however, treated groups were fed 0.2 ml of several herbal medicine-concentrated solution (PA (x2, several herbal medicine-concentrated solution 1 group); PB (x4 several herbal medicine-concentrated solution 2 group) daily for 6 weeks. Result : The weight of PA was higher than that of control, but weight of PB was lower than control. The blood level of control increased continuously, reaching to 350mg/dL after 6 weeks, however, PA and PB showed a fast reduction of blood glucose. In blood glucose tolerance test, PA and PB showed better resistance than control. The GOT level in significantly(p<0.05) decreased in PA and PB compared with control group. The BUN and creatinine levels are significantly(p<0.01) decreased in PA compared with control group. Feeding of several herbal medicine-concentrated solution in a concentration of PA had an efficient effect on regeneration or recovery of Langerhans islet and ${\beta}-cell$ damaged by STZ. More Langerhans islet and high insulin-immunohistochemical resistance were observed in PA compared with control, but they were higher in PB than in PA. The number of Langerhans islet ${\beta}-cell$ and Langerhans islet. Conclusions : The result from the six weeks of observation demonstrates that the several herbal medicine concentrated solution have a positive effect of lowering the level of blood sugar and they increased insulin concentration. They have an effect for recovery of pancreas tissue and recovery of kidney, liver function from a diabetes mellitus.