• 전기학회논문지
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• 제65권6호
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• pp.955-961
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• 2016

Fault location estimation is an important element for rapid recovery of power system when fault occur in transmission line. In order to calculate line impedance, most of fault location algorithm uses by measuring relaying waveform using DFT. So if there is a calculation error due to the influence of phasor by DC offset component, due to large vibration by line impedance computation, abnormal and non-operation of fault locator can be issue. It is very important to implement the robust fault location algorithm that is not affected by DC offset component. This paper describes an enhanced fault location algorithm based on the DC offset elimination filter to minimize the effects of DC offset on a long transmission line. The proposed DC offset elimination filter has not need any erstwhile information. The phase angle delay of the proposed DC offset filter did not occurred and the gain error was not found. The enhanced fault location algorithm uses DFT filter as well as the proposed DC offset filter. The behavior of the proposed fault location algorithm using off-line simulation has been verified by data about several fault conditions generated by the ATP simulation program.

• 대한기계학회논문집B
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• 제27권7호
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• pp.948-955
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• 2003

Pressure coefficient in rotating discharge hole was measured to gain insight into the influence of rotation to the discharge characteristics of rotating discharge hole. Pressure measurements were done by the telemetry system that had been developed by the authors. The telemetry system measures static pressure using piezoresistive pressure sensors. Pressure coefficients in rotating discharge hole were measured in longitudinal direction and circumferential direction with various rotating speed and 3 pressure ratios. From the results, the pressure coefficient, and therefore the discharge coefficient, is known to decrease with the increase of Ro number owing to the increase of flow approaching angle to the discharge hole inlet. However, there exists critical Ro number where the decrease rate of discharge coefficient with the increase of Ro number changes abruptly; flow separation occurs from the discharge hole exit at this critical Ro number. Critical Ro number increases with the increase of length-to-diameter ratio, but the increase is small where the length-to-diameter ratio is higher than 3. The decrease rate of discharge coefficient with the increase of Ro number depends on the pressure recovery at the discharge hole, and the rate is different from each length-to-diameter ratio; it has tendency that the short discharge hole shows higher decrease rate of discharge coefficient.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.2315-2320
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• 2016

Background: This study investigated the influence of religious beliefs on the health of cancer patients and identified the factors contributing to the influence. Materials and Methods: A questionnaire survey was conducted using a convenient sampling method. A structured questionnaire was used to the samplings, and the data of 200 cancer patients were collected. Results: The effects of religion on the health of cancer patients achieved an average score of 3.58. The top five effects are presented as follows: (a) Religion provides me with mental support and strength, (b) religion enables me to gain confidence in health recovery, (c) religion motivates me to cope with disease-related stress positively and optimistically, (d) religion helps me reduce anxiety, and (e) religion gives me courage to face uncertainties regarding disease progression. Moreover, among the demographic variables, gender, type of religion, and experience of religious miracles contributed to the significantly different effects of religion on patients. Specifically, the effect of religion on the health of patients who were female and Christian and had miracle experiences was significantly (p< .01) higher than that on other patients. Conclusions: These results are helpful in understanding the influence of religious beliefs on the health of cancer patients and identified the factors contributing to the influence. The result can serve as a reference for nursing education and clinical nursing practice.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.511-511
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• 2009

Lignocellulosic biomass is the most abundant organic material on earth and also promising raw material for bioenergy production. Agricultural residues in the process of bio-oil extraction, is an abundant and low-cost lignocellulosic material. The technology for conversion of lignocellulosic biomass resources to fuels and chemicals, such as ethanol, has been under development for decades. One of the well-studied technologies that are currently being commercialized is to use a dilute acid-catalyzed pretreatment followed by enzymatic hydrolysis and fermentation to produce ethanol. In this work, the dilute-acid hydrolysis of agricultural residues was optimized through the utilization of statistical experimental design. Evaluation criteria for optimization of the pretreatment conditions were based on high xylose recovery and low inhibitor contents in the hydrolyzates. The purpose of this study was to gain a more accurate understanding of the quantities of acid required for effective hydrolysis and the reactivity trade-offs with reaction time and temperature that will enable overall process optimization.

• 한국구조물진단유지관리공학회 논문집
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• 제12권5호
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• pp.65-73
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• 2008

본 연구는 칼만(Kalman) 필터 적용에 따른 LQG 제어기의 안정도 여유 상실을 극복하기위해 적용한 LTR 제어 시스템의 성능을 시간영역과 주파수영역에서 분석해 보고, 설계에 중요한 요소인 안정도 여유의 회복이 DUOX 구조물에 대해서도 실현되는지 여부를 확인해 보고자 함에 그 목적이 있다. 제어 대상의 구조물은 4층 골조로서 상부에 TMD와 AMD로 구성된 DUOX 시스템이 설치된 하이브리드 시스템이다. LTR/DUOX 제어기법으로 제어한 결과, 주파수응답의 Bode 선도를 통해 구한 게인 여유가 약 30dB로써 LQG/DUOX 제어기의 유실된 게인 여유를 20배 이상 회복시켜 보다 안정도 강인성이 우수한 제어기 설계가 구현되었다.

• 한국통신학회논문지
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• 제21권3호
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• pp.737-746
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• 1996

In this paper, we present simulation result of quantization effects about a new Angular From Carrier Recovery Loop(AF CR loop) for PSK modulation technique. AF CR loop includes detected angle symbol and Multi Level hardimiter. In general, detected angle is used in dtermining symbol. Because detected angle is used to make an error signal of phase detector output, hardware implementation of AF CR loop is simpler than that of other loops. Before hardware implementation of AF CR loop, the result due to quantization effect should be investigated. In order to confirm quntization effect of AF CR loop, we evaluate performance of this loop by Monte-Carlosimulation method. Under both in the AWGN and Jake's fading noise channel environments, we confirmed the characteristics of AF CR loop in terms of RMS jitter due to quntization effect. Differential APSK modulation schemeis used in this paper. Especially, Jake's fading channel is used as a channel model and also AGC(Automatic Gain Control) is used in the overall process of performance evaluation. We obtained the resonable result of quantization effect about AF CR loop. With the result of performanceevaluation based on quantization effects, we can expect to operate AF CRloop under the fading channel environments reasonably well.

• 대한조선학회논문집
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• 제30권1호
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• pp.30-44
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• 1993

추진 효율 향상을 위한 비대칭형 전류 고정날개-프로펠러 추진 시스템의 성능해석에 대한 이론적 실험적 고찰과 이에 대한 비교를 수행하였다. 성능해석을 위한 비대칭 및 대칭 해석 프로그램은 양력면 이론에 의해 개발되어졌으며, 실험과의 상호관계를 통하여 보다 정도 높은 설계 및 성능해석을 수행할 수 있도록 만들어졌으며 특히 불균일 반류에서의 고정날개 성능해석을 통한 비대칭 설계가 가능하여 졌다. 개발된 프로그램을 이용하여 새로운 비대칭 고정날개를 설계하였으며 성능해석을 이론적으로 수행한 결과 단독 프로펠러에 비하여 약 6%의 효율증가를 보이고 있다.

• Toxicological Research
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• 제12권2호
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• pp.309-318
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• 1996

This study was conducted to investigate the subacute intravenous toxicity of rHu-EPO in Sprague-Dawley rats. rHu-EPO was daily administered to male and female rats for 30 days with different dose levels(100, 500, 2,500 unit/ kg). After the administration period of 30 days, 5 males and 5females rats per each dose group were assigned for recovery period of additional 30 days. There were no clinical signs compared with control group but slight decrease in spontaneous motor activities and locomotions were observed at high dose groups of males and females. In males, feed consumption was reduced at 500 unit/kg and body weight gain was retarded. In the administration sites of tail, focal congestion was observed in a few animals treated with rHu-EPO. No deaths were occurred during the course of study. In hematological examination. a significant increase of hemoglobin and hematocrit was observed in the males and females rats receiving high dose of rHu-EPO. rHu-EPO administration for 30 days showed a marked decrease in glucose concentration. At the highest dose groups, there was a significant incerase in the weights of spleens in both sexes. but this was considered to be related to its pharmacological activity. These results indicate that rHu-EPO does not induce any significant toxic effect on Sprague-Dawley rats for 30 days.

• Journal of Power Electronics
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• 제17권6호
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• pp.1391-1401
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• 2017

In this paper, a secondary resonance half-bridge dc-dc converter with an inductive output filter is presented. The primary side of such a converter utilizes asymmetric pulse width modulation (APWM) to achieve zero-voltage switching (ZVS) of the switches, and clamps the voltage of the switch to the input voltage. In addition, zero current switching (ZCS) of the output diode is achieved by a half-wave rectifier circuit with a filter inductor and a resonant branch in the secondary side of the proposed converter. Thus, the switching losses and diode reverse-recovery losses are eliminated, and the performance of the converter can be improved. Furthermore, an inductive output filter exists in the converter reduce the output current ripple. The operational principle, performance analysis and design equation of this converter are given in this paper. The analysis results show that the output diode voltage stress is independent of the duty cycle, and that the voltage gain is almost linear, similar to that of the isolation Buck-type converter. Finally, a 200V~380V input, 24V/2A output experimental prototype is built to verify the theoretical analysis.

• 동의신경정신과학회지
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• 제30권3호
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• pp.119-128
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• 2019

Objectives: This study suggests the application of philosophical counseling in the clinical field of Korean medicine and analyze the specific case. Methods: Through the analysis of coexisting factors of Korean medicine and philosophical counseling, we establish the area of philosophical counseling that Korean medicine practitioner can apply in the medical field. We described effects of philosophical counseling on the patient's symptom and the progress after discharge through a counseling approach based on philosophical questions. Results: During philosophical counseling, the Korean medical doctor asks questions about the nature of suffering and encourages patients to gain insight into their problems. In answering the vital philosophical questions, the patient leads to a creative interpretation of future life directions. We described the method of specific approaches through the description of the two cases. Conclusions: The philosophical counseling is compatible with the concept of Korean medicine, therefore, a Korean medicine practitioner can induce the recovery of mind and body through the creative interpretation of the patient by asking the patient the appropriate question which causes reflective thinking.