• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.603-605
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• 1997

A new algorithm using 1-dimensional wavelet transform for autofocusing of optical instrument has been developed. Previous studies based on the conventional frequency analysis have shown that as the lens-object distance approaches the optimum value, the high frequency energy in the corresponding image shows a consistent increase. However, as conventional frequency analysis techniques hide spatial distribution of each band energy, shape information in the original signal cannot be easily utilized. In this paper, a newly devised wavelet based focus measuring scheme is presented. Unlike other frequency domain analysis techniques that simply produce "frequency-only" spectra, wavelet analysis provides a "time-frequency" localized view of a given signal. As a result, both frequency band filtering and spatial distribution filtering can easily be realized. Depending on the proposed focus quality measuring algorithm, a fast and reliable automatic focus adjustment of optical devices could be implemented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기설비전문위원
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• pp.66-70
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• 2006

Frequency is an important operating parameter of a power system. Electric power systems sustain transient frequency swings whenever the balance between generation and load does not no longer hold. To cope with this Constraints, il requires an accurate and high speedy frequency deviation estimation technique and suitable adjustment to obtain the power system energy balance. This paper describes the design, computational aspects and implementation of an iterative technique for measuring power system. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154[KV] double T/L system by using EMTP software. Some test results are presented in the paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 전문대학교육위원
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• pp.68-71
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• 2004

Frequency is an important operating parameter of a power system. Electric power systems sustain transient frequency swings whenever the balance between generation and load does not no longer hold. To cope with this Constraints, it requires an accurate and high speedy frequency deviation estimation technique and suitable adjustment to obtain the power system energy balance. This paper describes the design, computational aspects and implementation of an iterative technique for measuring power system. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154[KV] double T/L system by using EMTP software. Some test results are presented in the paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술대회 논문집 전문대학교육위원
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• pp.92-95
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• 2003

Frequency is an important operating parameter of a power system. Electric power systems sustain transient frequency swings whenever the balance between generation and load does not no longer hold. To cope with this Constraints. it requires an accurate and high speedy frequency deviation estimation technique and suitable adjustment to obtain the power system energy balance. This paper describes the design, computational aspects and implementation of an iterative technique for measuring power system. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154[KV] double T/L system by using EMTP software. Some test results are presented in the paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 전문대학교육위원
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• pp.145-149
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• 2005

Frequency is an important operating parameter of a power system. Electric power systems sustain transient frequency swings whenever the balance between generation and load does not no longer hold. To cope with this Constraints, it requires an accurate and high speedy frequency deviation estimation technique and suitable adjustment to obtain the power system energy balance. This paper describes the design, computational aspects and implementation of an iterative technique for measuring power system. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154[KV] double T/L system by using EMTP software. Some test results are presented in the paper.

• 대한가정학회지
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• 제38권6호
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• pp.149-169
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• 2000

The purpose of this study was to examine the environmental characteristics of adolescents in low-income families, identify the high-risk & protective factors among environmental contexts surrounding adolescents, and investigate the relative importance of high-risk & protective factors to adolescents'psychological and behavioral adjustment separately. The present study was the primary research of developing prevention program for adolescents'deviant behaviors in low-income families. Subjects of this study consisted of 176 adolescents drawn from 8 social-welfare institutions in Chungbuk province. The pilot study was done to examine the applicability of survey instrument. Data were analyzed by the frequency, percentage, Pearson correlation, stepwise regression using SPSS/WIN program. The results were as followings: 1. There was statistically correlated with each other in environmental high-risk and protective factors except an housing environment. The results implies that environmental contexts itself surrounding adolescents in low-income families can be either high-risk factors or protective factors. 2. The adolescents in low-income families perceived that stresses from consumer and school environments were high-risk factors among other environmental contexts. 3. The adolescents in low-income families perceived that resources from friend and school were protective factors among other environmental contexts. 4. The stresses from friend and eating behaviors were significant factors predicting adolescents'relative psychological adjustment. However, the behavioral adjustment was not predicted by environmental contexts. 5. The resources from school, consumer, and eating behaviors were significant factors predicting adolescents'relative psychological adjustment. Also, the resources from school, eating behavior, and family were predictors of behavioral adjustment. This research implies that the findings can be based on the development of prevention program for adolescents deviant behaviors in low-income families.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권4호
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• pp.201-205
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• 2004

The CCFL dimming control methods are generally used lamp current regulation or average current adjustment method feeding the CCFL inverter. Inverter operation frequency is higher than resonant frequency for safe operation. In this study, we design the half-bridge type series and parallel resonant converter circuit that switches at variable frequency modulation methods to control the output power. This method has advantages such as low EMI and reduced harmonics, and it is convenient for dimming control using a microprocessor. The validity of this study is confirmed from the simulation and experimental results.

• 디지털산업정보학회논문지
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• 제9권1호
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• pp.53-58
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• 2013

In this paper, we proposed low power algorithm for battery residual capacity and a task. Algorithm the mobile devices power of the battery residual capacity for the task to perform power consumption to reduce the frequency alters. Task is different in power consumption according to kinds of in time accomplishment device to use. Adjustment of power consumption analyzes kinds of given tasks from having the minimum power consumption task to having the maximum power consumption task. Control frequency so that power consumption waste to be exposed to battery residual capacity can be happened according to the results analyzed. Experiment the frequency by adjusting power consumption a method to reduce using [7] and in the same environment power of the battery residual capacity consider the task to perform frequency were controlled. Efficiency was proved compare with the experiment results [7]. The experiments results show increment in the number of processing by 45.46% comparing with that [7] algorithm.

• 대한기계학회논문집B
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• 제21권10호
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• pp.1262-1272
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• 1997

An experimental study on the frequency control of an inverter heat pump to get the desired indoor room temperature has been conducted for the performance characteristics during the steady, 4, 8, and 16 step frequency operations. The heat pump model used in this study was operated to meet the experimental conditions of ASHRAE standard. The performance of the system was tested by measuring the temperature and pressure of the refrigerant, and cooling capacity, power consumption, etc. of the system. As the controlling frequency steps increased, the running time of the compressor increased as well as the electric consumption of the system and the cooling energy due to the wall heating load. However, the average cooling COP was improved.

• 디지털융복합연구
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• 제13권8호
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• pp.515-523
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• 2015

이 연구의 목적은 융합 여가스포츠 활동에 참여하는 대학생들의 사회적 지지가 자아존중감 및 대학생활적응에 미치는 인과관계를 규명하는 데 있다. 이 연구의 대상은 경기도, 충청도, 전라도에 위치한 대학교에서 실시하고 있는 여가스포츠 관련 교과를 수강한 수강생 300명이다. 이중 불성실한 응답으로 간주되는 59부를 제외하여 총 241부를 최종 유효표본으로 선정하였다. 이들을 대상으로 다음과 같은 결론이 도출되었다. 첫째, 사회적 지지의 하위요인인 가족의 지지와 타인의 지지 모두 자아 존중감의 긍정적 자아에는 정적인 영향을 미치는 것으로 나타났고, 부정적 자아에는 부적인 영향을 미치는 것으로 확인되었다. 둘째, 여가스포츠 활동에 참여하는 대학생들의 자아존중감은 대학생활적응에 정적인 영향을 미치는 것으로 확인되었다. 셋째, 여가스포츠 활동에 참여하는 대학생들의 사회적 지지는 대학생활 적응에 유의한 영향을 미치는 것으로 나타났다.