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An integrated manufacturing and distribution model for a multi-echelon structure

  • Hwang, Heung-Suk
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1990.04a
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    • pp.222-244
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    • 1990
  • A multi-echelon structure of manufacturing and distribution system in considered, where the raw materials are transformed into a finished good through a number to manufacturing echelons and it is distributed to the lower echelons(retailers, or customers). The raw material, work-in-process, finished good inventory and the distribution costs are unified into one model. The objective is to determine the ordering policy of raw materials, manufacturing lot size, the number of sub-batch and the distribution policy of the finished good which minimize the annual total system cost. A computer program for a heuristic search technique is developed, by which a numerical example is examined.

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An Investigation into the Impact on Voltage Sag due to Faults in Low Voltage Power Distribution Systems

  • Aggarwal R. K.
    • KIEE International Transactions on Power Engineering
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    • v.5A no.2
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    • pp.97-102
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    • 2005
  • Voltage sags are the most widespread quality issues affecting distribution systems. This paper describes in some detail the voltage sag characteristics due to different types and locations of fault in a practical low voltage power distribution system encountered in the UK. The results not only give utility engineers very useful information when identifying parts of the system most likely to pose problems for customer equipments, but also assist the facility personnel to make decisions on purchasing power quality mitigation equipment.

Isolation and Identification of Candida dubliniensis and Distribution of Candida spp. from Oral Cavity of Healthy People

  • Kim, Su Jung
    • Korean Journal of Clinical Laboratory Science
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    • v.45 no.4
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    • pp.144-148
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    • 2013
  • Candida spp. are yeast form fungi, which cause an opportunistic infections in a immune suppressed patients however it is a normal flora of the respiratory system, the gastrointestinal system, and the urogenital system of healthy person. It is investigated that the distribution of Candida spp. cause an oral disease from oral cavity of healthy people and also identified Candia dubliniensis. Distribution and identification of the yeast form fungi in oral cavities of healthy people was investigated by an automatic identifier, VITEK2 system. We found 21 strains of Candida albicans, 3 strains of Candida famata, one strain of Candida tropicalis, Candida haemulonii, Candida krusei, and Candida dubliniensis. In addition, one strain of Cryptococcus spp., Saccharomyces spp., and two unknown strains were isolated. Candida dubliniensis which forms a mass by more than 2 chlamydospores was isolated from a healthy person for the first time. Candida dubliniensis was not grown at $42^{\circ}C$ whereas Candida albicans was grown well. It is known that Candida dubliniencis was isolated in AIDS while it is found in healthy people from this study, which will be helpful to investigate the distribution of Candida spp.

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An Adaptive Reclosing Scheme Based on the Classification of Fault Patterns in Power distribution System (사고 패턴 분류에 기초한 배전계통의 적응 재폐로방식)

  • Oh, Jung-Hwan;Kim, Jae-Chul;Yun, Sang-Yun
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.3
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    • pp.112-119
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    • 2001
  • This paper proposes an adaptive reclosing scheme which is based on the classification of fault patterns. In case that the first reclosing is unsuccessful in distribution system employing with two-shot reclosing scheme, the proposed method can determine whether the second reclosing will be attempted of not. If the first reclosing is unsuccessful two fault currents can be measured before the second reclosing is attempted, where these two fault currents are utilized for an adaptive reclosing scheme. Total harmonic distortion and RMS are used for extracting the characteristics of two fault currents. And the pattern of two fault currents is respectively classified using a mountain clustering method a minimum-distance classifier. Mountain clustering method searches the cluster centers using the acquired past data. And minimum-distance classifier is used for classifying the measured two currents into one of the searched centers respectively. If two currents have the different pattern it is interpreted as temporary fault. But in case of the same pattern, the occurred fault is interpreted as permanent. The proposed method was tested for the fault data which had been measured in KEPCO's distribution system, and the test results can demonstrate the effectiveness of the adaptive reclosing scheme.

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Diagnosis of Lead Time Demand Based on the Characteristics of Negative Binomial Distribution (음이항분포의 특성을 이용한 조달기간 수요 분석)

  • Ahn Sun-Eung;Kim Woo-Hyun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.28 no.2
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    • pp.146-151
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    • 2005
  • Some distributions have been used for diagnosing the lead time demand distribution in inventory system. In this paper, we describe the negative binomial distribution as a suitable demand distribution for a specific retail inventory management application. We here assume that customer order sizes are described by the Poisson distribution with the random parameter following a gamma distribution. This implies in turn that the negative binomial distribution is obtained by mixing the mean of the Poisson distribution with a gamma distribution. The purpose of this paper is to give an interpretation of the negative binomial demand process by considering the sources of variability in the unknown Poisson parameter. Such variability comes from the unknown demand rate and the unknown lead time interval.

Diagnosis of Lead Time Demand Based on the Characteristics of Negative Binomial Distribution (음이항분포의 특성을 이용한 조달기간 수요 분석)

  • Ahn, Sun-Eung;Kim, Woo-Hyun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.28 no.4
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    • pp.79-84
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    • 2005
  • Some distributions have been used for diagnosing the lead time demand distribution in inventory system. In this paper, we describe the negative binomial distribution as a suitable demand distribution for a specific retail inventory management application. We here assume that customer order sizes are described by the Poisson distribution with the random parameter following a gamma distribution. This implies in turn that the negative binomial distribution is obtained by mixing the mean of the Poisson distribution with a gamma distribution. The purpose of this paper is to give an interpretation of the negative binomial demand process by considering the sources of variability in the unknown Poisson parameter. Such variability comes from the unknown demand rate and the unknown lead time interval.

A Re-Configuration Genetic Algorithm for Distribution Systems (배전계통에서 유전적 알고리즘을 이용한 접속변경순서결정방법)

  • Choi, Dai-Seub
    • Proceedings of the KIEE Conference
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    • 2005.05b
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    • pp.62-63
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    • 2005
  • Recently, sectionalizing switches have been coming to be operated by remote control through the distribution SCADA system. However, the problem of determining the optimal switching sequence is a combinatorial optimization problem, and is quite difficult to solve, Hence, it is imperative to develop practically applicable solution algorithms create a new arbitral distribution system configuration from an initial configuration, and some of these algorithms do not show a load transfer sequence to reach the objective system.

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A Re-Configuration Genetic Algorithm for Distribution Systems (배전계통에서 유전적 알고리즘을 이용한 접속변경순서 결정방법)

  • Choi, Dai-Seub
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.11a
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    • pp.381-383
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    • 2004
  • Recently, sectionalizing switches have been coming to be operated by remote control through the distribution SCADA system. However, the problem of determining the optimal switching sequence is a combinatorial optimization problem, and is quite difficult to solve. Hence, it is imperative to develop practically applicable solution algorithms create a new arbitral distribution system configuration from an initial configuration, and some of these algorithms do not show a load transfer sequence to reach the objective system.

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A Re-Configuration Genetic Algorithm for Distribution Systems (배전계통에서 유전적 알고리즘을 이용한 접속변경순서결정방법)

  • Choi, Dai-Seub
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.05a
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    • pp.418-420
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    • 2005
  • Recently, sectionalizing switches have been coming to be operated by remote control through the distribution SCADA system. However, the problem of determining the optimal switching sequence is a combinatorial optimization problem, and is quite difficult In solve. Hence, it is imperative to develop practically applicable solution algorithms create a new arbitral distribution system configuration from an initial configuration and some of these algorithms do not show a load transfer sequence to reach the objective system.

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Study for importing and exporting database in Distribution Automation System (NDIS와 배전자동화시스템 연계방안에 관한 연구)

  • Cho, Nam-Hun;Ha, Bok-Nam;Lim, Seong-Il;Kang, Moon-Ho
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.489-491
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    • 2000
  • A DAS(Distribution Automation System) enhances the efficiency and productivity of a utility. It also provides intangible benefits such as improved public image and market adventages. This paper discusses an approach to the integration of NDIS(New Distribution Information System) and DAS that will allow benefits from both technologies to support a common database and distributed computing architecture, thereby improving the ability of many functions to justify implementation of integrated systems based on transferring' data comparisons.

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