• Title/Summary/Keyword: Transformation power

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Transformation of Cooperative Groups for Agricultural Production with the Change Agricultural Productive Force (농업생산력의 변화에 따른 농업생산조직의 발전과정)

  • Joe, Soung-Back;Choi, Min-Ho
    • Journal of Agricultural Extension & Community Development
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    • v.3 no.1
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    • pp.1-16
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    • 1996
  • The purpose of this study was to interpret the transformation of Cooperative Groups for Agricultural Production(CGAP) with the change of the Agricultural Productive Force. The specific objectives were; 1) To investigate the change of agricultural labour-power, 2) To investigate the change of agricultural mechanization and arable land, 3) To interpret the transformation and content of CLAP. The population of farmhouseholds has decreased continuously since the late 1960s. Especially, with the move-outs of youth ages of twenties to forties, the condition of agricultural labour-power has been more serious. The processing of agricultural mechanization was a small scale step in the 1970s, but after the 1980s there was a spread of middle-large machines. However the usage rate of agricultural machines was constrained by the bad conditions of arable land. From the 1970s to now, the CGAP have bean processed by many kinds of patterns. In the 1970s, the lack of labour-power caused the creation of the Co-Working Team. After the late of 1970s, the wage of agricultural employees was raised, because the working population of agriculture was cut down. Also, the induction of agricultural machine was promoted. As a result, in the 1980s, the Machine-Using Team occurred due to these conditions of agricultural productive force. In the late of 1980s, the population decreased more rapidly, and the use of large machines were spread. Than farmhouseholds laking labour-power gave a trust to other farmhouseholds and Teams which had machines. In 1990, Given-Trust Cooperations were enacted by law, and in order to overcome the lack of labour-power, and solve the problem of the successors of agriculture, Cooperative Organizations were also enacted by law. Finally, in Korea from the 1970s to now, as the agricultural productive force has barn changed, the Co-Working Team was transformed into the Machine-Using Team, and the Machine-Using Team was transformed into the Given-Trust Cooperation, and the Cooperative Organization.

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Vibration Power Flow Analysis of Coupled Shell Structures (연성된 쉘 구조물의 진동 파워흐름해석)

  • Kim, Il-Hwan;Hong, Suk-Yoon;Park, Do-Hyun;Kil, Hyun-Gwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.352.2-352
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    • 2002
  • In this paper, Power Flow Analysis (PFA) method has been applied to the prediction of vibration energy density and intensity of coupled shell structures in the medium-to-high frequency ranges. To consider the wave transformation at joint between shell elements, power transmission and reflection coefficients are investigated for various joint angles, and here Donnell-Mushtari thin shell theory has been used. (omitted)

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A Study on PWM Buck-Boost AC-AC Converter for Improvement of Power Quality of Custom Power (Custom Power의 전력품질 향상을 위한 PWM Buck-Boost AC-AC 컨버터에 대한 연구)

  • Choi Nam-Sup
    • Proceedings of the KIPE Conference
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    • 2002.11a
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    • pp.129-132
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    • 2002
  • In this paper, a PWM Buck-Boost AC-AC converter for improvement of power quality of custom power is presented. The PWM Buck-Boost AC-AC converter is modelled by using circuit DQ transformation whereby the both static and dynamic characteristics are analyzed completely. Finally, the converter system is implemented with the design criteria and the experimental results show the validity of modelling and analysis.

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World Geodetic System Coordinate Transformation of The New Distribution Information System (신배전정보시스템의 세계측지계 좌표변환)

  • Jang, Jung-Hwan;Kwon, Jay-Hyoun;Kim, Dong-Young;Cho, Yong-Ju
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2007.04a
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    • pp.59-63
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    • 2007
  • Each country uses its own datum which well represent its topography. The uses of the space technology such as GPS and the effort of establishing the consistent data over the world, Korea changed the survey act to use a world geodetic system from January 1, 2007. In this study, spatial analysis carried out to transform the GIS DB of electric power distribution system based on the old Tokyo datum the new world geodetic system, KGD 2002. Based on the study, problems on the transformation had been identified and efficient solutions are suggested. The data used for the 7 parameter similarity transformation in this study is the blueprints of the electric equipment and base maps. It is expected that this study provide general scheme and procedure for efficient GIS DB transformation to the new world geodetic system.

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Validation Comparison of Credit Rating Models Using Box-Cox Transformation

  • Hong, Chong-Sun;Choi, Jeong-Min
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.3
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    • pp.789-800
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    • 2008
  • Current credit evaluation models based on financial data make use of smoothing estimated default ratios which are transformed from each financial variable. In this work, some problems of the credit evaluation models developed by financial experts are discussed and we propose improved credit evaluation models based on the stepwise variable selection method and Box-Cox transformed data whose distribution is much skewed to the right. After comparing goodness-of-fit tests of these models, the validation of the credit evaluation models using statistical methods such as the stepwise variable selection method and Box-Cox transformation function is explained.

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Extraction of a Distance Parameter in Optical Scanning Holography Using Axis Transformation

  • Kim, Tae-Geun;Kim, You-Seok
    • Journal of the Optical Society of Korea
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    • v.14 no.2
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    • pp.104-108
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    • 2010
  • We proposed an axis transformation technique which reveals a distance parameter directly from optical scanning holography (OSH). After synthesis of a real-only spectrum hologram and power fringe adjusted filtering, we transform an original frequency axis to a new frequency axis using interpolation. In the new frequency axis, the filtered hologram has a single frequency which is linearly proportional to the distance parameter. Thus, the inverse Fourier transformation of the filtered hologram gives a delta function pair in the new spatial axis. Finally, we extract the distance parameter by detecting the location of the delta function pair.

SAMPLE ENTROPY IN ESTIMATING THE BOX-COX TRANSFORMATION

  • Rahman, Mezbahur;Pearson, Larry M.
    • Journal of the Korean Data and Information Science Society
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    • v.12 no.1
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    • pp.103-125
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    • 2001
  • The Box-Cox transformation is a well known family of power transformation that brings a set of data into agreement with the normality assumption of the residuals and hence the response variable of a postulated model in regression analysis. This paper proposes a new method for estimating the Box-Cox transformation using maximization of the Sample Entropy statistic which forces the data to get closer to normal as much as possible. A comparative study of the proposed procedure with the maximum likelihood procedure, the procedure via artificial regression estimation, and the recently introduced maximization of the Shapiro-Francia W' statistic procedure is given. In addition, we generate a table for the optimal spacings parameter in computing the Sample Entropy statistic.

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Evaluation of Transformation Capacity for Degradation of Ethylene Chlorides by Methylosinus trichosporium OB3b

  • Lee, Eun-Yeol;Kang, Jung-Mee;Park, Sung-Hoon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.5
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    • pp.309-312
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    • 2003
  • The transformation capacity (T$\_$c/) of Methylosinus trichosporium OB3b in the degradation of ethylene chlorides was determined by measuring the decrease of soluble methane monooxygenase (sMMO) activity of resting cells in batch experiments. All measurements of sMMO activity were taken in the presence of 20 mM formate to avoid the deficiency of reducing power, and within 2 hrs to avoid the effect of natural inactivation from instability of the resting cells. The constant T$\_$c/ values of 0.58 ${\pm}$ 0.132 and 0.80 ${\pm}$ 0.17 ${\mu}$mol/mg cell were obtained for trichloroethylene (TCE) and 1,2-dichloroethylene (cis and trans-1,2-DCE), respectively, regardless of their concentrations. The transformation capacity measured by this method can be used to predict the amount of cells that should be stimulated in in-situ bioremediation.

Sliding-Mode Based Direct Power Control of a Doubly Fed Induction Generator for Wind Turbines (슬라이딩 모드 기반의 이중여자 유도형 풍력발전시스템의 직접전력제어기법)

  • Kim, Won-Sang;Sim, Gyung-Hun;Lee, Kyo-Beum;Jeong, Byoung-Chang;Song, Seung-Ho
    • The Transactions of the Korean Institute of Power Electronics
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    • v.13 no.2
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    • pp.152-162
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    • 2008
  • This paper presents a sliding mode controller (SMC) to directly control the active and reactive powers of a doubly ffd induction generator (DFIG) for wind turbines. Sliding-mode control (SMC) and space-vector modulation (SVM) are combined to ensure high-performance operation. SMC scheme is designed to provide robust and fast power controls without frame transformation and current controller used in the conventional FOC drive. Simulation results and experimental results demonstrate that proposed methods preserve the effectiveness and robustness during variations of active and reactive power.

Low Power Contrast Enhancement for OLED Displays (OLED 디스플레이를 위한 저전력 대조비 향상 기법)

  • Kim, Jin-Hwan;Lee, Chul;Lee, Chul-Woo;Kim, Chang-Su
    • Journal of Broadcast Engineering
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    • v.17 no.2
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    • pp.284-294
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    • 2012
  • A low power contrast enhancement algorithm for OLED displays is proposed in this work. The proposed algorithm increases the contrast of the image based on a linear transformation function, while reducing the power consumption of OLED displays. Furthermore, the proposed algorithm extends the global contrast enhancement to local contrast enhancement using the block-based transformation function. Simulation results demonstrate that the proposed algorithm reduces the power consumption, while enhancing the contrast of an input image.