• 조명전기설비학회논문지
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• 제14권1호
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• pp.102-108
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• 2000

본 논문은 주상변압기의 부하관리를 위한 부하 상관식 조정에 관한 실증적 연구 결과를 제시하였다. 부하 상관식 조정을 위하여 주상 변압기의 사용전력량[kWh]과 최대 부하[A] 사이의 상관 관계를 분석하였다. 또한 상관식의 정확성을 높이기 위하여 12개의 지역 패턴으로 분류하였다. 그리고 각 지역 패턴에 24개씩의 표본 주상 변압기를 선정하였다. 부하 상관식에 사용된 데이터의 신뢰성을 위하여 표본 주상변압기에 부하관리기를 설치하였다. 온-라인 데이터 취득을 통하여, 데이터 베이스를 구축하였다. 부하 상관식 조정에 있어서 본 논문에서는 두 부분에 대해 고려를 하였다. 그중 하나는 부하 상관식의 적합성 또 하나는 과부하로 인한 주상변압기 손실 방지이다. 최종적으로 1, 2차 상관함수를 병용하는 상관식올 제안하였다. 또한 사례 연구를 통하여 제안한 부하 상관식이 기존에 사용하는 상관식 보다 오차 비율이 감소했음을 입증하였다.

• 설비공학논문집
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• 제17권12호
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• pp.1185-1191
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• 2005

Published correlation equations of the enthalpy of vaporization are reviewed and a new four-parameter correlation equation is proposed. Performance of the proposed equation is examined using the ASHRAE data for 22 pure substance refrigerants as reference data. The new equation yields an average absolute deviation of $0.05\%$, which is smaller than those of published equations, such as equations of Guermouche-Vergnaund $(0.08\%)$, Aerebrot $(0.13\%)$, Radoz-Lydersen $(0.08\%)$, and Somayajulu $(0.08\%)$. The three adjustable parameters of the modified correlation are optimized and reported for 22 substances. The equation proposed in this work is valid over the entire temperature range where data points exist.

• International Journal of Air-Conditioning and Refrigeration
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• 제14권3호
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• pp.118-123
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• 2006

A few commonly used correlation equations of the enthalpy of vaporization essential to the analysis of refrigeration cycles are reviewed. A new four-parameter correlation equation is proposed assuming that the enthalpy of vaporization could be represented with a linear form of the temperature and an additional function which slowly decreases as the temperature increases. It is not a common practice to measure the enthalpy of vaporization by experiment; therefore, performance of the new correlation is examined using numeric data from the ASHRAE tables for 22 pure substance refrigerants. The new correlation equation and other existing ones are fitted to the data optimizing the root mean squared deviation. All data points are weighted equally and NBP (normal boiling point) is used as a fixed point since the NBP is important for refrigeration application. The new four-parameter equation yields an average absolute deviation of 0.05% for 22 refrigerants which is smaller than those of other four-parameter equations, such as Guermouche-Vergnaud (0.08%), Aerebrot (0.13%), Radoz-Lyderson (0.08%), and Somayajulu four-parameter equation (0.08%).

• International Journal of Air-Conditioning and Refrigeration
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• 제12권4호
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• pp.214-219
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• 2004

A few commonly used correlation equations of the enthalpy of vaporization are reviewed and a new three-parameter correlation equation is proposed. Performance of the pro­posed equation is examined using the data listed in the ASHRAE table for 22 pure substance refrigerants. The new equation yields an average absolute deviation of $0.14\%$ for 22 refrig­erants, which is better than those of other equations, such as Xiang $(0.18\%),$ Majer-Svoboda­Pick $(0.18\%),$ and Somayajulu equation $(0.23\%)$.

• 설비공학논문집
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• 제15권8호
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• pp.704-709
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• 2003

A few commonly used correlation equations of the enthalpy of vaporization are reviewed and a new three-parameter correlation equation is proposed. Performance of the proposed equation is examined using the data listed in the ASHRAE table for 22 pure substance refrigerants. The new equation yields an average absolute deviation of 0.14% for 22 refrigerants, which is better than those of other equations, such as Xiang (0.18%), Major-Svoboda-Pick (0.18%), and Somayajulu equation (0.23%).

• 설비공학논문집
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• 제10권5호
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• pp.550-557
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• 1998

The saturated vapor density correlation proposed here relates logarithmic density to the inverse of temperature. Its performance is examined correlating the date listed in the ASHTAE tables for 40 refrigerants. The correlation equation is valid over the entire range where data point exist and gives better results than a conventional equation with the same number of adjustable coefficients. Number of terms in the equation is a variable so that great flexibility can be given to the representation of data.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1996년도 추계학술발표회논문집
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• pp.101-103
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• 1996

This Paper describes Peak load forecasting technique of pole transformers with correlation equation. While customers are demanding safe energy supply, current correlation equation that is used for load management of pole transformers has some problems. To get accurate correlation equation. several correlation equation were examined using past data and nu data collected using the measuring instrument developed for this study. It was recognized that the quadratic equation was the most accurate for peak load forecasting from working electrical energy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.929-931
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• 1998

This paper describes the peak load forecasting technique of distribution transformers with correlation equation. While customers are demanding safe energy supply, conventional correlation equation that is used for load management of distribution transformers in domestic has some problems. To get accurate correlation equation, se-correlation equation were examined using new collected using the measuring instrument dev for this study. It was recognized that the qua equation was the most accurate for peak forecasting from working electrical energy.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.766-770
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• 2005

Cascade-Correlation Neural Networks Model(CCNNM) is used to estimate daily evaporation using limited climatical variables such as atmospheric temperature, dewpoint temperature, relative humidity, wind speed, sunshine duration and radiation. DeBruln equation is applied to estimate daily free-surface evaporation. It is converted into pan evaporation using pan coefficient. The results of CCNNM shows better than those of Debruin equation. This research represents that the strong nonlinear relationship such as evaporation modeling can be generalized by the CCNNM ; a special type of Backpropagation algorithm Neural Networks Model.

• Bulletin of the Korean Chemical Society
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• 제25권8호
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• pp.1165-1170
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• 2004

The applicability of the combined nearly ideal binary solvent/Redlich-Kister (CNIBS/R-K) equation for correlation of various solvatochromic parameters (SP) with composition is shown employing 84 experimental data sets for aqueous and organic binary solvent systems at temperatures ranging 15 to $75^{\circ}C$. The model provides a simple computational model to correlate/predict different SP values in various binary solvent systems. In proposed equations, $MPD_s$ (mean percentage deviations) are between 0.0500% and 6.9591% in mixtures of dimethyl sulfoxide with 2-methylpropan-2-ol and benzene with 2-methylpropan-2-ol, respectively. Correlation of the calculated and experimental values of various SP give an equation with an overall mean percentage deviation (OMPD) of 1.1900, $R^2$ = 0.99692, s.e = 0.01223 and F = 341925.51. Approximately 70% of the calculated SP values have IPD (individual percentage deviation) lower than one and it is possible to predict unmeasured SP values by using only eight experimental data.