• Progress in Superconductivity
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• v.7 no.1
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• pp.36-40
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• 2005

The problem of fluctuation-induced digital errors in a rapid single flux quantum (RSFQ) circuit has been a very important issue. In this work, we calculated the bit error rate of an RSFQ switch used in superconductive arithmetic logic unit (ALU). RSFQ switch should have a very low error rate in the optimal bias. Theoretical estimates of the RSFQ error rate are on the order of $10^{-50}$ per bit operation. In this experiment, we prepared two identical circuits placed in parallel. Each circuit was composed of 10 Josephson transmission lines (JTLs) connected in series with an RSFQ switch placed in the middle of the 10 JTLs. We used a splitter to feed the same input signal to both circuits. The outputs of the two circuits were compared with an RSFQ exclusive OR (XOR) to measure the bit error rate of the RSFQ switch. By using a computerized bit-error-rate test setup, we measured the bit error rate of $2.18{\times}10^{-12}$ when the bias to the RSFQ switch was 0.398 mA that was quite off from the optimum bias of 0.6 mA.

• The Journal of Korean Physical Therapy
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• v.15 no.2
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• pp.168-181
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• 2003

The purpose of this study was to investigate the effects of circuit weight training(CWT) on isokinetic muscle strength and body composition in elderly. The subjects who engaged in this experiment exercised at 40$\%$ of 1-RM, 12 repetitions, followed by 15 sec as the subject moved to the each break training program which was consist of the circuit of 10 stations performed on 3 set a day, circuits 3 days a week during 10 weeks. The assessment of isokinetic factor was in concentric flexors and extensors of right and left knee joint. Tests were performed on the Cybex 770 Isokinetic Dynamometer and body composition were estimated the three parts of chest, abdomen and anterior thigh by using skinfold caliper, calculated the average and followed by Seri and Brozek way. Statistical analysis were performed using analysis of variance paired t-test, accepting level for all significant was above $\alpha$=.05 and $\alpha$=.01. Following is as a result of 10 weeks circuit weight training. 1. At the $60_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly (p < .01). 2. At the $180_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly (p < .01). 3. At the $60_{\circ}$ /sec, the right and left knee isokenetic concentric flexors and extensors average power increased significantly(p < 0.5, p < .01) and at the $180_{\circ}$ /sec, the right extensors didn't show any statistical significant. 4. At the $60_{\circ}$ /sec, the right and left knee Isokinetic concentric flexors and extensors total work increased significantly(p < .05, p < .01) but at the $180_{\circ}$ /su right concentric flexors didn't show any statistical significant. 5. The body composition changed significantly(p < .01). These results suggest that 10 weeks circuit weight training increases the peak torque, average power, total work significantly and decreases the $\%$body fat significantly.

• The Journal of Korean Physical Therapy
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• v.15 no.4
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• pp.398-411
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• 2003

The purpose of this study was to investigate the effects of circuit weight training(CWT) on isokinetic muscle strength and body composition in elderly. The subjects who engaged in this experiment exercised at $40\%$ of 1-RM, 12 repetitions, followed by 15 sec as the subject moved to the each break training program which was consist of the circuit of 10 stations performed on 3 set a day, circuits 3 days a week during 10 weeks. The assessment of isokinetic factor was in concentric flexors and extensors of right and left knee joint. Tests were performed on the Cybex 770 Isokinetic Dynamometer and body composition were estimated the three parts of chest, abdomen and anterior thigh by using skinfold caliper, calculated the average and followed by Seri and Brozek way. Statistical analysis were performed using analysis of variance paired t-test, accepting level for all significant was above ${\alpha}=.05$ and ${\alpha}=.01$. Following is as a result of 10 weeks circuit weight training. 1. At the $60_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly(p<.01). 2. At the $180_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly(p<.01). 3. At the $60_{\circ}$ /sec, the right and left knee isokenetic concentric flexors and extensors average power increased significantly(p<.05, p<.01) and at the $180_{\circ}$ /sec, the right extensors didn't show any statistical significant. 4. At the $60_{\circ}$ /sec, the right and left knee Isokinetic concentric flexors and extensors total work increased significantly(p<.05, p<.01) but at the $180_{\circ}$ /sec right concentric flexors didn't show any statistical significant. 5. The body composition changed significantly(p<.01). These results suggest that 10 weeks circuit weight training increases the peak torque, average power, total work significantly and decreases the $\%$body fat significantly.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.1
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• pp.13-20
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• 2020

Accurate parameters based on equivalent circuit are required for high-performance field-oriented control in a three-phase induction motor. In a normal case, stator resistance can be accurately measured using a measuring equipment. Except for stator resistance, all machine parameters on the equivalent circuit should be estimated with particular algorithms. In the viewpoint of traditional regions, the parameters of an induction motor can be identified through the no-load and standstill test. This study proposes an identification method that uses the d-axis model of the induction motor in a stationary frame with the predefined information on stator resistance. Mutual inductance is estimated on the rotational dq coordination similar to that in the traditional no-load experiment test. The leakage inductance and rotor resistance can be estimated simply by applying different voltages and frequencies in the d-axis model of the induction motor. The proposed method is verified through simulation and experimental results.

• Journal of the Korea Society of Computer and Information
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• v.22 no.8
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• pp.1-7
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• 2017

In this paper, we proposed the test equipment that can perform separate performance tests to mass-produce the Automatic Test Equipment. Until now, the performance test of the ATE has been performed after it has been assembled perfectly. It is possible to perform the performance test only when the external device manufacturing and setting of measurement resources and the internal wiring work have been completed. So we have been studying test equipment that separately tested the switching devices that played a key role in the performance of the ATE. To build the test equipment, we reviewed the circuit card assemblies that make up the switching devices. We designed a test equipment that satisfies the performance test and apply the completed test equipment to the actual production process to analyze whether it was effective in improving the time and workability of the performance test. The test equipment has the advantage that it can be used universally in the mass production process of ATE with the same type of switching device.

• 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 the Korean Institute of Telematics and Electronics C
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• v.35C no.12
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• pp.13-22
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• 1998

In this paper, we propose a high-performance BICS(built-in current sensor) which is fabricated in 0.8${\mu}{\textrm}{m}$ single-poly two-metal process for IDDQ testing of CMOS VLSI circuit. The CUT(circuit under test) is 4-bit full adder with a bridging fault. Using two nMOSs that have different size, two bridging faults that have different resistance values are injected in the CUT. And controlling a gate node, we experimented various fault effects. The proposed BICS detects the faulty current at the end of the clock period, therefore it can test a CUT that has a much longer critical propagation delay time and larger area than conventional BICSs. As expected in the HSPICE simulation, experimental results of fabricated chip demonstrated that the proposed BICS can exactly detect bridging faults in the circuit.

• Journal of Power System Engineering
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• v.9 no.1
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• pp.64-69
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• 2005

In evaluation of electronic reliability on the PCB(Print Circuit Borad),electrochemical migration is one of main test objects. The phenomenon of electrochemical migration occurs in the environment of the hight humidity and the hight temperature under bias through a continuous aqueous electrolyte. In this paper, the generating mechanism of electrochemical migration is investigated by using water drop acceleration test under various waters. The waters used in the water drop test are city water, distilled water and ionic water. It found that the generated velocity of electrochemical migration depended on electrolyte quantity which included in the various waters.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.113-121
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• 2015

This study aims to examine the risk of electrical fire in places where electric heat wires are used. In general, the use of electric heating wires is becoming more common and prevalent in a bid to prevent increasing damage caused by freezing and bursting in residential water pipes, factory pipes and irrigation pipes in vinyl greenhouse and a variety of heat wire products are available in market with legal safety requirements imposed on them. However, the widespread use of anti-freezing burst heat wire products has caused increasing incidents of fire, which often fail to be incorporated into statistics due to quick onsite extinguishing and insignificant damage although damage is gradually on the rise. Against this backdrop, this study aims to look into the possibility of ignition caused by electric heat wires and the mechanism of how it turns into catching fire through overheat and short circuit tests for anti-freezing burst electrical heat wires (hereinafter called the 'heat wire') and expects to serve as the basis for further observations and analyses on the cause of fire and the process of ignition in a scientific manner.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1291-1292
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• 2007

Recently, there were many researches for efficiency improvement of DSC. Among of these works, research of surface treatment is still a prerequisite for electron diffusion, light-harvesting and surface state of DSC.[1] Using of the surface treatment, it can be raise up porosity of $TiO_2$ nano-crystalline structure on photo-electrode. There are chemical, physical, electrical and optical methods which raise up its porosity. In this paper, we have designed and manufactured MOPA-type ultrasonic circuit (100W, frequency and duty variable). Manufactured ultrasonic circuit to use to force cavity density and power into $TiO_2$ paste. Then, we have optimized forcing time, frequency and duty of ultrasonic irradiation for surface treatment of photo-electrode of DSC. In I-V characteristic test of DSC, ultrasonic and thermal treated DSC shows 19% improved its efficiency against monolithic DSC. And it shows stability of light-harvesting from drastically change of light irradiation test.