• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1313-1317
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• 2013

With increasing demand of power, the equipment of power system is enlarging and the absolute capacity is going up. As a result, when a fault occurs, the fault current is consistently increasing. Therefore, I suggested some solution for limiting the fault current more efficiently. This study shows the characteristics of superconducting limiting elements and normal conducting elements combined with a transformer. We performed a short-circuit test about the fault current by using SCR switching control system operated from a CT. When short circuit accidents happened in the secondary side of a transformer, fault currents flowed and a SCR switching control system was operated. It resulted in a decrease of the fault current in the limited elements of third winding connected in parallel. For this test, we used YBCO thin films and normal conducting elements as the limited elements. Within a cycle, a superconducting fault current limiter with YBCO thin films reduced more than 90% of fault current because the resistance of superconducting elements sustainedly grew. On the other hand, the limiter with normal conductors limited as much as a set value because its resistance characteristic was linear. Consequently, in case of the limiter with superconductor, limiting range of the circuit was wide but the range of protective detection was undefined. In contrast, as for the limiter with normal conductors, limiting range and protection duty were appropriate.

• Journal of Power Electronics
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• v.18 no.3
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• pp.714-722
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• 2018

This paper presents a wide-range speed control scheme of brushless DC (BLDC) motors based on a hall sensor with separated low- and normal-speed controllers. However, the use of the hall sensor signal is insufficient to detect motor speed in the low-speed region because of low sensor resolution and time delay. In the proposed method, a micro-stepping current control method according to the torque angle variation is presented. In this mode, the motor current frequency and rotating angle are determined by the reference speed without the actual speed fed by the hall sensor. The detected torque angle is used to adjust the current value in a limited band to control the current value in accordance with the load. The torque angle is detected exactly at the changing point of the hall sensor signal. The rotor can follow the rotating flux with the variable torque angle. In a normal speed range, the conventional vector control scheme is used to control the motor current with a PI speed controller using the hall sensor. The torque characteristics are analyzed on the basis of the back EMF and current shape. To adopt the vector control scheme, the continuous rotor position is estimated by the measured speed and hall sensor position. At the mode changing point between low and normal speed range, the proper initial current command and reference rotor position are calculated. The calculated current command can reduce the torque ripple during transient mode. The proposed method is simple but effective in extending the speed control range of a conventional BLDC motor with hall sensor without the need for a high-resolution encoder. The effectiveness of the proposed method is verified by various experiments on a practical BLDC motor.

• Journal of Acupuncture Research
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• v.25 no.2
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• pp.139-149
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• 2008

Objectives : The 7-zone-diagnostic system is a diagnostic device to predetermine bodily locations by measuring the energy of body. This study was to investigate the relation between the different patterns of Zone 2, 6 of Factor AA in VEGA DFM 722(VEGA, Germany), 7-zone-diagnostic system and clinical parameters. The purpose of this study was relation Korean traditional medicine and western medicine with the data from 7-zone-diagnostic system and the clinical parameters. Methods : This study was carried out with the data from some clinical parameters. We made two groups according to the Factor AA patterns of VEGA DFM 722. The Factor AA pattern of Group A is that the red bar graph of zone 2 was higher than the normal range and the red bar graph of zone 6 was lower than the normal range. The Factor AA pattern of Group B was that the red bar graph of zone 2 was lower than the normal range and the red bar graph of zone 6 was higher than the normal range. After the data from clinical parameters to correspond with conditions of each group were selected, the data from clinical parameters between each gropus analyzed statistically. Results and Conclusions : The values of Direct Bilirubin, GOT, BUN and BUN/Creatinine ratio of Group A were higher than them of Group B. The values of Sodium and Tyroxine of Group A were lower than them of Group B. These results mean that Group A has low energy but has increading tendency. To conclude, it is thought that the red bar graph of zone 2 is higher, the group is the more increasing and the red bar graph of zone 6 is lower, the group has the lower energy.

• Journal of Chest Surgery
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• v.22 no.4
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• pp.562-572
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• 1989

The changes of serum glutamic oxaloacetic transaminase [SGOT], serum glutamic pyruvic transaminase [SGPT], serum lactic dehydrogenase [LDH] and serum creatine phosphokinase [CPK] were examined during and after the open heart surgery. In the total of 52 patients with heart diseases including 40 cases of congenital heart anomalies and 12 cases of acquired valvular heart diseases who undergone open heart surgery under cardiopulmonary bypass. The results obtained are as follows: 1. The average value of SGOT before surgery was 30.27 [ 18:86 units. The enzyme was reached to the maximum of 139.88 [ 89.43 units on the 1st day after the operation [p< 0.05], the enzyme activity was gradually decreased from the 3rd day after the operation, returned to the normal range on the 7th day after the operation. 2. The average value of SGPT before surgery was 14.36 [ 7.45 units. The enzyme was reached to the maximum of 34.67 [ 27.64 units on the 2nd day after the operation, but it was valueless statistically, the enzyme activity was gradually decreased from the 3rd day after the operation, returned to the normal range on the 5th day after the operation. 3. The average value of LDH before surgery was 263.07 * 86.66 units. The enzyme was reached to the maximum of 662.29 * 303.60 units on the 2nd day after the operation [p < 0.05], the enzyme activity was gradually decreased from the 5th day after the operation, returned to the normal range on the 7th day after the operation. 4. The average value of CPK before surgery was 141.35 * 43.44 units. The enzyme was reached to the maximum of 377.42 [ 222.02 units on the 1st day after the operation [p < 0.05], the enzyme activity was gradually decreased from the 5th day after the operation, returned to the normal range on the 7th day after the operation. 5. In the relationships of the serum enzymes and duration of the extracorporeal circulation, the values on the group over 90 minute of the extracorporeal circulation were increased than on the group below 90 minute of the extracorporeal circulation, but it was valueless statistically.

• Journal of Chest Surgery
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• v.15 no.1
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• pp.46-52
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• 1982

Activities of serum glutamic pyruvic transaminase [SGPT], serum glutamic oxaloacetic transaminase [SGOT] and serum lactic dehydrogenase [LDH] were determined during and after surgery In a total of 18 patients with heart diseases Including 8 cases of congenital heart anomaly and 10 cases of acquired valvular diseases who undergone open heart surgery under cardiopulmonary bypass. The results obtained are as follows: 1]The average value of the activity of SGPT before the surgery was $27.94{\pm}12.24$ units. The value was increased following the operation and reached to the maximum value of $43.83{\pm}37.02$ units 2 days after the operation, which was slightly deviated from the normal range. The enzyme activity returned to the normal range of $32.82{\pm}23.61$ units 4 days after the operation. 2]The average value of the activity of SGOT before the surgery was observed to be $30.5{\pm}11.29$ units. The value increased during the operation and reached to the maximum value of $95.56{\pm}43.38$ units. 2 days after the operation, the enzyme activity was gradually decreased thereafter and returned to the normal range 6 days after the operation. 3]The average value of the activity of serum LDH before the surgery was found to be $258.0{\pm}88.96$ units. The value was increased during the operation and reached to the maximum value of $930.55{\pm} 258.23$ units 2 days after the operation. The enzyme activity was gradually decreased thereafter and returned to normal range 7 days after the operation. 4]It was observed that the longer the time required for the extracorporeal circulation in the open heart surgery became, the greater the changed in activity of SGOT, SGPT and serum LDH were found.

• Journal of Acupuncture Research
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• v.25 no.1
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• pp.15-23
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• 2008

Objectives : The aim of our study was to demonstrate the clinical application of a diagnosis relating the 7-zone-diagnostic system and heart rate variability. Materials and Methods : Subjects were divided into two groups according to the factor AA form of the 7-zone-diagnostic system(VEGA-DFM722, VEGA, Germany). Subjects in group A showed a factor-AA red bar graph in which zone 2 was higher than the normal range, and zone 6 was lower than the normal range. Subjects in group B showed a factor-AA red bar graph in which zone 2 was lower than the normal range, and zone 6 was higher than the normal range. We investigated how to differentiate the index of heart-rate variability(HRV, LX-3202, LAXTHA, Korea) for each group. We did independent sample t-tests and evaluated the results of the HRV at the 5% significance level using SPSS 10.0 for Windows. Results : The differences of the MeanRR, MeanHRV, SDNN, complexity, HRV-index, RMSSD, SDSD, and pNN50 values between the groups was not significant. The differences of the Ln(TP), Ln(VLF), Ln(HF), LF/(LF+HF), LF/HF, norm LF, and norm HF values between the groups was also not significant. The differences were not significant, but generally the values of SDNN, complexity, RMSSD, SDSD, Ln(VLF), Ln(HF) and norm LF for group B were higher than those for group A, and the values of pNN50 and norm HF for group B were lower than those for group A. Conclusions : This study suggests that differences in the HRV values between the groups was not significant, but group B has a tendency to be healthier than group A because of stress. Accordingly, further study will be required.

• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.231-236
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• 1998

This study was undertaken to evaluate the psychosocial status of the preoperative orthognathic surgery patient through SCL-90-R. Subjects used in this study were composed of 67 patients under presurgical orthodontic treatment. Males are 40 and females are 27. Comparison between the personality characteristics of male and female patients was made by the t-test. From this study, the results were as follows. 1. In preoperative patients group, all T-scores were within the normal range. 2. In male patients group, all T-scores were within the normal range. 3. In female patients group, all T-scores were within the normal range. 4. Only in PHOB scales, the T-scores of male patients group were higher than those of female patients group. 5. Although all T-scores were within the normal range,9 patients($13.4\%$ of all patients) shows abnormal T-scores in at least one scale.($T{\geqq}65$)

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.3
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• pp.204-210
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• 2007

This study was intended to compare the cranial base morphology between the mandibular prognathism and maxillary retrognathism in skeletal class III patients. The subject of the present study was composed of 88 patients divided into two groups; Group 1 (Skeletal Class III with mandibular prognathism. SNA within normal range, SNB over normal range, n=54) and Group 2(Skeletal Class III with maxillary retrognathism. SNA below normal range, SNB within normal range, n=34). Lateral cephalogram were taken immediate before surgery and 18 landmarks were used to analyze the characteristics of cranial base and maxillomandibular skeleton. The result revealed that cranial base angle is significantly smaller in Group 1 than Group 2, which implies the influence of the cranial base angulation on the mandibular position. However the posterior cranial base length did not influence the mandibular horizontal position and anterior cranial base length did not influence the maxillary horizontal position. As the anterior cranial base length was closely related with ramal height, it is recommendable to investigate the regulatory mechanism of chondrogenesis of cranial base and condyle cartilage in the future research.

• Korean Journal of Veterinary Service
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• v.25 no.1
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• pp.45-52
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• 2002

The acute phase serum protein response is a well-known general indicator of inflammation, trauma or other pathological conditions and its relevance for the monitoring of the health status of domestic animals is being increasingly realized. The changes in serum protein composition which occur after tissue damage represent a part of the systemic response of the injured animals which is mediated by pro-inflammatory cytokines such as TNF-$\alpha$, IL-6 and IL-1. These responses play a vital role in containing the tissue damage and enhancing the processes of repair and resolution. From a clinical perspective, the assay of acute phase proteins can provide a method for detecting inflammation. In animals, the most sensitive acute phase proteins are haptoglogin, serum amyloid A and at-acid glycoprotein in response to inflammatory condition. The aim of this study was to assess the diagnostic value of the concentrations of serum amyloid A(SAA) and haptoglobin(HP) in serum of pigs infected with Aujeszky's disease virus(ADV). Fifty pigs infected with ADV and 5 normal pigs were used in this experiment. The mean serum concentration of Shh of pigs infected with ADV was 96.8 $\pm$ 7.1 $\mu\textrm{g}$/㎖(range, 36.0∼187.5 $\mu\textrm{g}$/㎖) and that of normal pigs was 42.9$\pm$3.3 $\mu\textrm{g}$/㎖(range, 17.3∼127.8 $\mu\textrm{g}$/㎖). The mean serum concentration of HP of pigs infected with ADV was 1,164.4 $\pm$ 96.9 $\mu\textrm{g}$/㎖ (range, 790.2∼l,769.2 $\mu\textrm{g}$/㎖) and that of normal pigs was 675.4 $\pm$ 56.3 $\mu\textrm{g}$/㎖ (range, 650.0-690.4 $\mu\textrm{g}$/㎖). The mean concentrations of SAA and HP in serum of pigs infected with ADV compared with those of normal pigs showed approximately a two-fold. It was concluded that the concentrations of Shh and HP in serum may proved to be diagnostic marker of Aujeszky's disease.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2283-2296
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• 1995

Experiments of normal shock wave/turbulent boundary layer interaction were conducted in a supersonic diffuser. The flow Mach number just upstream of the normal shock wave was in the range of 1.10 to 1.70 and Reynolds number based upon the turbulent boundary layer thickness was varied in the range of 2.2*10$^{[-994]}$ -4.4*10$^{[-994]}$ . The wall pressures in streamwise and spanwise directions were measured for two test cases, in which the turbulent boundary layer thickness incoming into the supersonic diffuser was changed. The results show that the interactions of normal shock wave with turbulent boundary layer in the supersonic diffuser can be divided into three patterns, i.e., transonic interaction, weak interaction and strong interaction, depending on Mach number. The weak interactions generate the post-shock expansion which its strength is strong as the Mach number increases and the strong interactions form the pseudo-shock waves. From the spanwise measurements of wall pressure, it is known that if the flow Mach number is low, the interacting flow fields essentially appear two-dimensional, but they have an apparent 3-dimensionality for the higher Mach numbers.