• 전기학회논문지P
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• 제59권2호
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• pp.191-196
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• 2010

The electricity distribution system in Korea is adopting a multi-grounding system. Protection of this distribution system against lightning is performed by installing overhead ground wires over the high voltage wires, and connecting the overhead ground wires to the ground every 200 m. The ground resistance in this system is limited not to exceed $50\Omega$ and overhead ground wire and neutral wire are multiple parallel lines. Although overhead ground wire and neutral wire are installed in different locations on the same pole, this circuit configuration has duplicated functions of providing a return path for unbalanced currents and protecting the distribution system against induced lightning. Therefore, the purpose of this study is to analyze the induced lightning shielding effect according to the neutral wire installation structure of a 22.9kV distribution line in order to present a new 22.9kV distribution line structure model and characteristics. This study calculated induced lightning voltage by performing numerical analysis when an overhead ground wire is present in the multi-grounding type 22.9kV distribution line structure, and calculated the induced lightning shielding effect based on this calculated induced lightning voltage. In addition, this study proposed and analyzed an improved distribution line model allowing the use of both overhead wire and neutral wire to be installed in the current distribution lines. The result of MATLAB simulation using the conditions applied by Yokoyama showed almost no difference between the induced lightning voltage developed in the current line and that developed in the proposed line. This signifies that shielding the induced lightning voltage through overhead wire makes no difference between current and proposed distribution line structures. That is, this study found that the ground resistance of the overhead wire had an effect on the induced lightning voltage, and that the induced lightning shielding effect of overhead wire is small.

• 패션비즈니스
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• 제20권1호
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• pp.1-16
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• 2016

Korean cosmetic distribution channels were formerly divided into sales visits and specialty shops, which made up the entire cosmetics market. However, recently the market and cosmetic distribution channels have become much more diversified. Thus, research for this study focused on the usage and purchase situations of cosmetic distribution channels depending on cosmetic type perception. This study also focused on the intent to purchase cosmetics by a cosmetic distribution channel in order to provide a precise cognitive background of consumers regarding cosmetic distribution channels. In doing so, the competitiveness of those channels could be procured and the causal relationships between these variables can be investigated. To achieve these purposes, the research model and hypotheses were derived through literature research on the cosmetics industry, cosmetic distribution channels, and consumers' intent to purchase. A survey was implemented from September $1^{st}$ to $14^{th}$, 2014 for empirical testing. and was given to female consumers in their 20s. 468 out of 500 surveys were collected; a total of 415 were used for analysis while the others were excluded due to with unreliable responses. The SPSS 21.0 program was used for analysis of materials. The overall conclusion of this study is that there is a relationship between perception of cosmetic distribution channels and intent to purchase. The above research results may stimulate establishment of marketing implications and research material when establishing marketing strategies to promote cosmetic distribution and consumption.

• 한국농공학회지
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• 제31권4호
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• pp.31-49
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• 1989

It is of the most urgent necessity to get hydrological time series of long duration for the establishment of rational design and operation criterion for the Agricultural hydraulic structures. This study was conducted to select best fitted frequency distribution for the monthly runoff and to simulate long series of generated flows by multi-season first order Markov model with comparison of statistical parameters which are derivated from observed and sy- nthetic flows in the five watersheds along Geum river basin. The results summarized through this study are as follows. 1. Both two parameter gamma and two parameter lognormal distribution were judged to be as good fitted distributions for monthly discharge by Kolmogorov-Smirnov method for goodness of fit test in all watersheds. 2. Statistical parameters were obtained from synthetic flows simulated by two parameter gamma distribution were closer to the results from observed flows than those of two para- meter lognormal distribution in all watersheds. 3. In general, fluctuation for the coefficient of variation based on two parameter gamma distribution was shown as more good agreement with the observed flow than that of two parameter lognormal distribution. Especially, coefficient of variation based on two parameter lognormal distribution was quite closer to that of observed flow during June and August in all years. 4. Monthly synthetic flows based on two parameter gamma distribution are considered to give more reasonably good results than those of two parameter lognormal distribution in the multi-season first order Markov model in all watersheds. 5. Synthetic monthly flows with 100 years for eack watershed were sjmulated by multi- season first order Markov model based on two parameter gamma distribution which is ack- nowledged to fit the actual distribution of monthly discharges of watersheds. Simulated sy- nthetic monthly flows may be considered to be contributed to the long series of discharges as an input data for the development of water resources. 6. It is to be desired that generation technique of synthetic flow in this study would be compared with other simulation techniques for the objective time series.

• International Journal of Korean Welding Society
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• 제4권1호
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• pp.23-29
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• 2004

In weaving welding where a V groove exists, the heat input distribution is an important factor that determines the defectiveness of the bead shape, undercut and over-lap. In this study, the amount of heat input, which is determined by the welding current, voltage, speed and weaving conditions is calculated through mathematical development and numerical methods. Furthermore, the heat input distribution as a two- dimensional heat source was observed when applied to each groove.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.975-980
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• 1993

In accordance with increase, if electronic power demanded, more efficient supervisory control of distribution system will be required. This study contains development of MMI(man-machine-interface) system with GUI(graphic-user-interface), for the automatic power distribution system. The main function of MMI system is to edit network of power distribution and to management of data base for network. The GUI function of MMI system enables more efficient management of power distribution system.

• International Journal of Reliability and Applications
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• 제10권1호
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• pp.43-57
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• 2009

In this article, we study the reliability equivalence factor of a series system. The failure rates of the system components are functions of time t. we study two cases of non-constat failure rates (i) weibull distribution (ii) linear increasing failure rate distribution. There are two methods are used to improve the given system. Two types of reliability equivalence factors are discussed. Numerical examples are presented to interpret how one can utilize the obtained results.

• 충청수학회지
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• 제21권2호
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• pp.157-163
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• 2008

We study essentially disjoint one dimensionally indexed classes whose members are distribution sets of a self-similar Cantor set. The Hausdorff dimension of the union of distribution sets in a same class does not increases the Hausdorff dimension of the characteristic distribution set in the class. Further we study the Hausdorff dimension of some uncountable union of distribution sets.

• 한국태양에너지학회 논문집
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• 제27권3호
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• pp.127-133
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• 2007

Underfloor air distribution system is generally known to be more energy-saving and provide more comfort as compared with overhead air distribution system. In practice, however, some buildings to which underfloor air distribution system is applied have less effectiveness in saving energy and are getting dissatisfaction with cold draft caused by wind velocity of air distribution in terms of comfort. It is judged that such problems are due to failure to consider properties of underfloor air distribution system in applying it and identical design with the design standards for the existing overhead air distribution system. This study aims at introducing an air conditioning type of the occupied zone for underfloor all distribution system to see its effectiveness in saving energy for air conditioning of the occupied zone through a comparative simulation with the existing air conditioning type.

• 한국유통학회지:유통연구
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• 제1권2호
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• pp.199-220
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• 1996

Our courtry's distribrtion business is on the luring point by opening the market to foreign countries from this year. It can be said that industrial goods are intermediated goods for the production of other goods or service So it requires quality and specialty than any other things. But the lack of understanding, small scale and classification by non-productive industry by government bring about difficulty to the distribution itself and other fields. Industrial goods have a long distribution channel. This distribution stracture can be reduce the channel by establishment of distribution complex. Establishment of distribution complex will strengthen the role of quality management and go far toward quality improvement. This study examine the distribution status of industrial goods, problems and study the extablishment of complex and expected affect.

• Communications for Statistical Applications and Methods
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• 제16권4호
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• pp.647-658
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• 2009

It is already known from the previous study that flood seems to have heavier tail. Therefore, to make prediction of future extreme label, some agreement of tail behavior of extreme data is highly required. The LH-moments estimation method, the generalized form of L-moments is an useful method of characterizing the upper part of the distribution. LH-moments are based on linear combination of higher order statistics. In this study, we have formulated LH-moments of five distributions useful in hydrology such as, two types of three parameter kappa distributions, beta-${\kappa}$ distribution, beta-p distribution and a generalized Gumbel distribution. Using LH-moments reduces the undue influences that small sample may have on the estimation of large return period events.