• 전기학회논문지
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• 제58권3호
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• pp.539-543
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• 2009

This paper describes the sensitivity enhancement in measurement of the hydrogen gas dissolved in oil using gas collection time. On-line gas measurement is a useful for continuous monitoring of power transformer. Recently many studies on hydrogen gas measurement, due to their simplicity and low price, have been done for transformer monitoring. In measurement of the hydrogen gas in oil, the suitable sensitivity and resolution in the desired ranges of the gas concentrations are needed for the reliable monitoring of power transformers. In this study, the sensor output trends were analyzed with the hydrogen gas collection time which means the time to collect the hydrogen gas before reaction of hydrogen gas sensor. It is indicated that the sensor outputs were increased with the increase of hydrogen gas collection times at the same hydrogen gas concentrations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.159-160
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• 2006

This paper discusses sensitivity analysis for determining adequate locations of series-type FACTS devices. The main objective of FACTS reinforcement is to alleviate line over-loadings against violation of thermal limits after disturbances. This paper, to obtain the information concerning series-type FACTS locations, proposes a formulation for the sensitivity of the PI (Performance Index) with respect to the variation of the branch parameters, and applies to 5-bus test system to show the effectiveness of the sensitivity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.847-849
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• 1998

In this paper, we propose the generalized on-line economic dispatch algorithm including transmission loss. it was derived from the process developing matrix form of the classic ELD problem. it can rapidly calculate generation power using transmission loss and transmission loss sensitivity calculated from the result of power flow analysis. Transmission loss sensitivity ${\partial}P_{loss}/{\partial}P_G$ is derived using optimization technique.

• 한국전자파학회논문지
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• 제15권6호
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• pp.573-578
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• 2004

전기 기폭장치(EED, electroexplosive device)는 브리지 와이어, 추진제, 리드 핀 및 금속관으로 구성되었고, 기폭신호가 인가되면 브리지와이어의 발열에 의해 추진제를 점화시킨다. 또한 고출력 통신기나 레이더에서 방사되는 전자파에 의해 EED는 예기치 않은 기폭이 발생할 수 있어, EED에 대한 EMC 설계 및 시험관련 군사규격서를 제정하여 적용하고 있다. 본 논문은 항공기에 대한 전기체 EMC 시험평가를 수행할 때, 항공기에 설치 된 EED 대신에 사용할 기폭용 퓨즈의 RF 감도 특성을 기술하였다 RF 기폭수준은 전송선로 이론을 활용하여 예측하였고, 군사규격서에 규정된 DC 감도와 RE 감도를 측정하였다.

• 한국학교ㆍ지역보건교육학회지
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• 제22권3호
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• pp.41-54
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• 2021

Objectives: This study aimed to confirm the degree of gender sensitivity, gender role conflict, nursing professionalism of nursing students and the factors that affect nursing professionalism. Methods: During Jan. 19 to Feb. 5 in 2021, the structured questionnaire was used for 187 nursing students by on-line research methods. Data were analyzed by descriptive analysis, mean comparison(t-test, ANOVA), correlation analysis(Pearson's correlation coefficient) and multiple regression using SPSS/WIN 25.0. Results: The gender sensitivity had positive relationship with nursing professionalism, and gender role conflict had negative relationship with nursing professionalism. And the prediction factors influencing nursing professionalism were major satisfaction, gender sensitivity and gender role conflict. The total variance was 8.2% by predictors. Conclusions: In order to improve the nursing professionalism of nursing students, various ways to increase the satisfaction level of major should be sought, and program should be prepared to improve gender sensitivity and reduce gender role conflict.

• Nuclear Engineering and Technology
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• 제39권2호
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• pp.133-142
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• 2007

The Electric Power Research Institute (EPRI) demonstrated a method for monitoring the performance of instrument channels in Topical Report (TR) 104965, 'On-Line Monitoring of Instrument Channel Performance.' This paper presents the results of several models originally developed by EPRI to monitor three nuclear plant sensor sets: Pressurizer Level, Reactor Protection System (RPS) Loop A, and Reactor Coolant System (RCS) Loop A Steam Generator (SG) Level. The sensor sets investigated include one redundant sensor model and two non-redundant sensor models. Each model employs an Auto-Associative Kernel Regression (AAKR) model architecture to predict correct sensor behavior. Performance of each of the developed models is evaluated using four metrics: accuracy, auto-sensitivity, cross-sensitivity, and newly developed Error Uncertainty Limit Monitoring (EULM) detectability. The uncertainty estimate for each model is also calculated through two methods: analytic formulas and Monte Carlo estimation. The uncertainty estimates are verified by calculating confidence interval coverages to assure that 95% of the measured data fall within the confidence intervals. The model performance evaluation identified the Pressurizer Level model as acceptable for on-line monitoring (OLM) implementation. The other two models, RPS Loop A and RCS Loop A SG Level, highlight two common problems that occur in model development and evaluation, namely faulty data and poor signal selection

• Structural Engineering and Mechanics
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• 제53권3호
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• pp.519-536
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• 2015

On-line electric vehicle (OLEV) is a new eco-friendly transportation system that collects electricity from a power cable buried beneath the road surface, allowing the system to resolve various problems associated with batteries in electric vehicles. This paper presents a finite element (FE) based thermo-mechanical analysis of precast concrete structures that are utilized in the OLEV system. An experimental study is also conducted to identify materials used for a joint filler, and the observed experimental results are applied to the FE analysis. Traffic loading and boundary conditions are modeled in accordance with the related standards and environmental characteristics of a road system. A series of structural analyses concerning various test scenarios are conducted to investigate the sensitivity of design parameters and to evaluate the structural performance of the road system.

• 전기학회논문지
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• 제63권6호
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• pp.828-833
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• 2014

Grid connected transformerless solar power generation system is frequently used with the benefits of cost and efficiency. However, significant DC leakage current can flow from the DC line into the ground with dielectric breakdown in the transformerless solar power generation system. The leakage current occurred in the DC line causes accidents such as fire and electric shock on human. To resolve this problem, high sensitivity DC leakage current sensor is needed. But recently the studies on safety of DC line are not performed. In this paper, a high sensitivity DC leakage current sensor that can detect DC leakage current in solar power generation system, is proposed. Based on the studies, DC leakage current sensor is fabricated and characteristic tests are carried out. Finally, the accuracy of sensor performance is verified by leakage current experiments in solar power generation system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.806-807
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• 2007

Systematic studies on the dispatch scheduling algorithm and related constraints can enhance the effectiveness of electricity market operation. When System Operator (SO) establishes a dispatch schedule, the bid information should be preserved in the schedule as much as possible. In this paper, we introduce a new type of sensitivity factor called Line Outage Impact Factor (LOIF) to screen a transmission line causing the most severe outage when scheduling the dispatch. This screening can assure the stable system operation and make an efficient feedback between the SO and market participants. We propose a transmission line contingency constrained Pre-dispatch algorithm using sensitivity indices in a suitable Pre-dispatch scheduling. The proposed algorithm has been tested on sample system and the results show more secure operation against critical contingencies.

• Structural Engineering and Mechanics
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• 제71권3호
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• pp.291-303
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• 2019

In the paper the analysis of natural vibrations of the transmission line with use of spectral elements and the laboratory experiments is performed. The purpose of the investigation is to analyze the natural vibrations of the transmission line and compare with the results obtained in the numerical simulations. Particular attention is paid to the hysteretic and aerodynamic damping analysis. Sensitivity of the wave number is performed for changing of the tension force, as well as for the different damping parameters. The numerical model is made using the Spectral Element Method. In the spectral model, for various parameters of stiffness, damping and tension force, the system response is checked and compared with the results of the accelerations obtained in the measurements. A frequency response functions (FRF) are calculated. The credibility of the model is assessed through a validation process carried out by comparing graphical plots of FRF and time history analysis and numerical values expressing differences in acceleration amplitude (MSG), phase angle differences (PSG) and differences in acceleration and phase angle total (CSG) values. The next aspect constituting the purpose of this paper is to present the wide possibilities of modelling and simulation of slender conductors using the Spectral Element Method. The obtained results show good accuracy in the range of both experimental measurements as well as simulation analysis. The paper emphasizes the ease with which the sensitivity of the conductor and its response to changes in density of spectral mesh division, tensile strength or material damping can be studied.