• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.213-224
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• 2010

In this paper, we propose an algorithm both geometric correction using a grid point image and radiometric adaptive projection that dependent upon the luminance of the input image and that of the background. This method projects and captures the grid point image then calculates the geometrically corrected position by difference between the two images. Next, to compensate color, a corrected image is calculated by the ratio divided luminance of an input image by luminance of arbitrary surface. In addition, we found the scaling factor which controls the contrast to avoid clipping error. At this time, the scaling factor is dependent on mean image lightness when background is determined. Experimental results show that the proposed method achieves good performance and is able to reduce the perceived color clipping and artifacts, better approximating the projection on a white screen.

• Journal of Electrical Engineering and Technology
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• v.3 no.4
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• pp.520-527
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• 2008

This work focuses on the evaluation of active power filter which is controlled by fuzzy logic and neural network based controller for harmonic mitigation and power factor enhancement. The APF consists of a variable DC voltage source and a DC/AC inverter. The task of an APF is to make the line current waveform as close as possible to a sinusoid in phase with the line voltage by injecting the compensation current. The compensation current is estimated using adaptive neural network. Using the estimated current, the proposed APF is controlled using neural network and fuzzy logic. Computer simulations of the proposed APF are performed using MATLAB. The results show that the proposed techniques for the evaluation of APF can reduce the total harmonic distortion less than 3% and improve the power factor of the system to almost unity.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.71-72
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• 2019

In this study, we describe a method of measuring position using the Additional Secondary Factor (ASF) compensation technique of the eLoran concept in the situation where only Loran-C signals are received without eLoran time broadcasting. Next, we describe the result of test performed to verify the method. The test results showed the position accuracy within 20m and we found the possibility of the method. The method is expected to be used to verify user positioning accuracy before improving Loran-C to eLoran.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.2
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• pp.21-31
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• 2018

PURPOSE: This study examined the differences between male and female workers by investigating the various factors that affected the workers' abilities to return to work according to the International Classification of Functioning standards. METHODS: We analyzed the personal factor, environmental factor, work performance and participation factor related to ICF according to worker's gender. For this purpose data from the third Worker's Compensation Insurance panel survey conducted by the Korea Workers' Compensation & Welfare Service were analyzed. In order to verify the research model, we used frequency analysis, cross analysis to compare the differences between male and female workers according to personal, environmental, work performance, and participation factors and hierarchical regression analysis to identify significant factors affecting job performance. RESULTS: The results, indicate that the level of education, license status, working period, socioeconomic status and employment type of female workers were lower than those of male workers. Factors that have the greatest influence on job performance are grade of disability, status of disability, economic activity status, and instrumental activities of daily living (p<.05). CONCLUSION: It is necessary to provide socially stable employment support and social policy support without discrimination to allow disabled female workers to return to work and maintain their jobs and to study factors influencing job performance further.

• Journal of Power Electronics
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• v.19 no.5
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• pp.1087-1098
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• 2019

In this paper, a detuning factor (DeFac) method is proposed to design the key parameters for optimizing the transfer power and efficiency of an Inductively Coupled Power Transfer (ICPT) system with primary-secondary side compensation. Depending on the robustness of the system, the DeFac method can guarantee the stability of the transfer power and efficiency of an ICPT system within a certain range of resistive-capacitive or resistive-inductive loads. A MATLAB-Simulink model of a ICPT system was built to assess the system's main evaluation criteria, namely its maximum power ratio (PR) and efficiency, in terms of different approaches. In addition, a magnetic field simulation model was built using Ansoft to specify the leakage flux and current density. Simulation results show that both the maximum PR and efficiency of the ICPT system can reach almost 70% despite the severe detuning imposed by the DeFac method. The system also exhibited low levels of leakage flux and a high current density. Experimental results confirmed the validity and feasibility of an ICPT system using DeFac-designed parameters.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.196-198
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• 2003

The low load power factor causes various problems such as the increase of the power loss and the voltage instability. The demand of reactive power increases continuously with the growth of active power and the restructuring of electric power companies makes the integrated management of ractive power troublesome, from which the systematic control of load power factor is required. In this paper, the load power factor sensitivity of the generation cost is derived and its effects in supplying the reactive power and enhancing the load power factor are analyzed in a small-scale power system. The load power factor sensitivity of the generation cost is applied for determining the locations and capacities of reactive power compensation devices. It is shown that the generation cost can be reduced and the system power factor can be enhanced effectively using the load power factor sensitivity.

• Proceedings of the KIEE Conference
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• summer
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• pp.153-155
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• 2004

Various problems such as the increase of the power loss and the voltage instability may often occur in the case of low load power factor. The demand of reactive power increases continuously with the growth of active power and the restructuring of electric power companies makes the integrated management of ractive power a troublesome problem, so that the systematic control of load power factor is required. In this paper, the load power factor sensitivity of the generation cost is used for determining the locations of reactive power compensation devices effectively and for enhancing the load power factor appropriately. In addition, the integrated costs are used for determining the value of the load power factor from the point of view of the economic operation. It is shown through the application to a large-scale power system that the system power factor can be enhanced effectively and appropriately using the load power factor sensitivity and integrated costs.

• The Journal of Korean Academic Society of Nursing Education
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• v.14 no.2
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• pp.195-204
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• 2008

Purpose: This study was performed to measure the justice of compensation (distributive justice, procedural justice) and the intention of turnover perceived by nurses, and to identify the relationship between these two variables. Method: This study was a cross-sectional survey. From May 26 to June 30, 2008, data were collected from the 300 nurses working at 6 general hospitals in 5 cities, Korea. Result: The score of compensatory justice was 2.47(distributive justice was 2.46, procedural justice was 2.48), and the score of turnover intention was 3.39. The Pearson Correlation Coefficient between these two variables was -.496. The perceived compensatory justice(distributive justice, procedural justice)by nurses, their age and working periods were the affecting factors on their turnover intention, and the power of explanation of these affecting factors was 43.4%. Conclusion: According to the results, procedural justice is the most powerful factor among these affecting factors. Therefore, it is concluded that to decrease nurses' turnover intention, nursing or hospital managers have to fairly operate their compensation system, especially procedural justice, in their organization.

• ETRI Journal
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• v.22 no.4
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• pp.32-39
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• 2000

In low earth orbit (LEO) satellite communication systems, more severe phase distortion due to Doppler shift is frequently detected in the received signal than in cases of geostationary earth orbit (GEO) satellite systems or terrestrial mobile systems. Therefore, an estimation of Doppler shift would be one of the most important factors to enhance performance of LEO satellite communication system. In this paper, a new adaptive Doppler compensation scheme using location information of a user terminal and satellite, as well as a weighting factor for the reduction of prediction error is proposed. The prediction performance of the proposed scheme is simulated in terms of the prediction accuracy and the cumulative density function of the prediction error, with considering the offset variation range of the initial input parameters in LEO satellite system. The simulation results showed that the proposed adaptive compensation algorithm has the better performance accuracy than Ali's method. From the simulation results, it is concluded the adaptive compensation algorithm is the most applicable method that can be applied to LEO satellite systems of a range of altitude between 1,000 km and 2,000 km for the general error tolerance level, M = 250 Hz.

• Journal of the Korea Fashion and Costume Design Association
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• v.20 no.1
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• pp.79-91
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• 2018

The objective of this study was to determine the influence of women's attitudes toward women's underwear on image-creation efficacy and appearance management attitude. A total of 405 surveys of women working at an industrial complex in the Daegu-Kyoungbuk area were used for data analysis. Frequency, factor analysis, reliability analysis, and regression analysis were used for data analysis. The findings were as follows. The sub-factors of women's attitudes regarding women's underwear were found to be 'aesthetics/body-style compensation', 'ostentation', 'functionality', and 'manner estimation' and the sub-factors of image-making efficacy were 'display confidence', 'face-image confidence' and 'display ability'. Appearance management attitude had factors such as total coordination, weight management, skin management, and pursuit of change. Aesthetics/body-style compensation, functionality, and ostentation, which were sub-variables of attitudes toward underwear, had a significant influence on image-creation efficacy. Aesthetics/body-style compensation and ostentation had significant influences on appearance management attitude. Aesthetics/body-style compensation was found to have a significant influence on all sub-variables of both image-creation efficacy and appearance management attitude.