• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.1
• /
• pp.35-45
• /
• 2013

Owing to the increase in the penetration of distributed generation the DGs connected to the distribution system have an effect on the system conditions of the transmission system and neighboring distribution systems. This makes the separate analysis of the transmission and distribution system no longer valid and requires the consideration of both the system in the analysis process. This paper proposes a transmission/distribution integrated analysis hybrid algorithm that would ensure the accurate analysis of the system by reflecting the results of the transmission and distribution system analysis on each other. Different scenarios are being analysed in order to verify the effectiveness of the hybrid algorithm by observing the effects of the DG connected distribution system on the transmission system and neighboring distribution systems. The algorithm and simulations performed are being conducted by MATLAB and the IEEE 30 bus system and a test distribution system has been utilized for the transmission and distribution systems respectively.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.784-791
• /
• 2008

In this study, we recognized about application of the load distribution factor for design of tunnel in 3D numerical analysis. Generally, load distribution factor of tunnel is applied to describe 3D arching effect that can not describe when 2D numerical analysis. Through result of 3D numerical analysis, we used to apply in numerical analysis for the load distribution factor that ratio of finally displacement to displacement of construction step. But 3D numerical analysis need to apply to load distribution factor for convenience of numerical analysis. Therefore, we proposed load distribution factor that reduce time and coast. It corrected variable of advanced length in load distribution factor of 3D numerical analysis.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.616-619
• /
• 2007

Nowadays, urbanized area expands its boundary, and distribution of urbanized area is gradually transformed into more complicated pattern. In Korea, SMA(Seoul Metropolitan Area) has outstanding urbanized area since 1950s. But it is ambiguous whether urban distribution is clustered or dispersed. This study aims to show the way in which expansion of urbanized area impacts on spatial distribution pattern of urbanized area. We use quadrat analysis, nearest-neighbor analysis and fractal analysis to know distribution pattern of urbanized area in time-series urban growth. The quadrat analysis indicates that distribution pattern of urbanized area is clustered but the cohesion is gradually weakened. And the nearest-neighbor analysis shows that point patterns are changed that urbanized area distribution pattern is progressively changed from clustered pattern into dispersed pattern. The fractal dimension analysis shows that 1972's distribution dimension is 1.428 and 2000's dimension is 1.777. Therefore, as time goes by, the complexity of urbanized area is more increased through the years. As a result, we can show that the cohesion of the urbanized area is weakened and complicated.

• The Journal of Industrial Distribution & Business
• /
• v.10 no.8
• /
• pp.17-24
• /
• 2019

Purpose - The purpose of this study is to find out research directions for distribution and fusion and complex field to many domestic and foreign researchers carrying out related academic research by confirming research trends in the Journal of Distribution Science (JDS). Research Design, Data, and Methodology - To do this, I used keywords from a total of 904 papers published in the JDS excluding 19 papers that were not presented with keywords among 923. The analysis utilized word clouding, topic modeling, and weighted frequency analysis using the R program. Results - As a result of word clouding analysis, customer satisfaction was the most utilized keyword. Topic modeling results were divided into ten topics such as distribution channels, communication, supply chain, brand, business, customer, comparative study, performance, KODISA journal, and trade. It is confirmed that only the service quality part is increased in the weighted frequency analysis result of applying to the year group. Conclusion - The results of this study confirm that the JDS has developed into various convergence and integration researches from the past studies limited to the field of distribution. However, JDS's identity is based on distribution. Therefore, it is also necessary to establish identity continuously through special editions of fields related to distribution.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.52 no.2
• /
• pp.69-78
• /
• 2003

This paper presents a voltage analysis method of distribution systems interconnected with DG(Distributed Generation). Nowadays, small scale DG becomes to be introduced into power distribution systems. But in that case, it is difficult to properly maintain the terminal voltage of low voltage customers by using only ULTC(Under Load Tap Changer). This paper presents a voltage analysis method of distribution systems with DC for proper voltage regulation of power distribution systems with ULTC. In order to develop the voltage analysis method, distribution system modeling method and advanced loadflow method are proposed. Proposed method has been applied to a 22.9 kV practical power distribution systems.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.6
• /
• pp.1043-1050
• /
• 2010

This paper examined the probabilistic load analysis for the tailplane during pitching maneuvering in the conceptual aircraft design phase. The flight load analysis based on the probabilistic distribution of design variables are compared with the results of the deterministic analysis. Two forms of variable distribution are used in this paper. One is standard normal distribution, the other distribution is calculated from the results of short-period longitudinal equation of aircraft motion. The influence of the distribution parameter on the probabilistic load analysis was investigated and the significant design variables that have an impact on the mean and variance of probabilistic load were identified. The comparison indicates that probabilistic load analysis provides more reliable probabilistic load distribution for the structural design than the traditional deterministic analysis.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2005.05b
• /
• pp.943-947
• /
• 2005

This study was intended to interpose an objection about the analysis of rainfall spatial distribution without a proper standard, and offer the improved approach using 1,he geostatistical analysis method to analyze it. For this, spatially distributed daily rainfall data sets were collected for 41 weather stations in study area, and variogram and correlation analysis were conducted. In the results of correlation analysis, it was found that the longer distance between the stations reduces the correlation of the rainfall data, and maltes the characteristics of the rainfall spatial distribution. The variogram analysis shows that correlation range was less than 50 km for the 17 daily rainfall data sets of total 91 sets. It says that it involves some rike, to determine the application method for rainfall spatial distribution without some qualifications, hence the Application standards of the Rainfall Spatial Distribution Analysis Technique, were essential and that was contingent on characteristics of rainfall and landscape.

• Journal of Korean Society of Water and Wastewater
• /
• v.13 no.2
• /
• pp.23-33
• /
• 1999

This study is to investigate the effect of C factor errors on the analysis of water distribution systems. For this purpose, an artificial distribution network and a real distribution network were selected as the study networks. Results are as follows. 1. The C factor of a pipe which has small velocity didn't give significant effect on the analysis of a water distribution system. 2. The effect of decreased value of C factors give more influence on the analysis of water distribution systems than that of the increased values. 3. For the C factor calibration, errors of the residual water heads as well as those of the head losses should be considered together. 4. In the analysis of water distribution systems, changes of C factors can give influences only on the nodes which locate behind the pipe. Therefore, this characteristics should be considered in the selection of nodes for the measurement of water heads.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.6
• /
• pp.737-743
• /
• 2013

This paper describes the overvoltage through lightning surge analysis on underground system in DC combined distribution systems. It is considered that operating micro grid including distributed generation with smart grid can make possibility of composing new distribution system different from existing one. However, there are many papers about low voltage DC distribution in grids or buildings but not many about replacement or distributing 22.9kV AC distribution system to DC system. Among many research need for DC system development, overvoltage is studied in this paper. Overvoltage is simulated on DC cable when lightning strikes to overhead grounding wire which is installed at the nearest location from power cable section. Analysis as well as modeling is performed in EMTP/ATPDraw. It is evaluated that analysis results can be used to design of DC underground distribution power cable system.

• Communications for Statistical Applications and Methods
• /
• v.21 no.3
• /
• pp.225-234
• /
• 2014

We propose a novel hierarchical clustering for distribution valued dissimilarities. Analysis of large and complex data has attracted significant interest. Symbolic Data Analysis (SDA) was proposed by Diday in 1980's, which provides a new framework for statistical analysis. In SDA, we analyze an object with internal variation, including an interval, a histogram and a distribution, called a symbolic object. In the study, we focus on a cluster analysis for distribution valued dissimilarities, one of the symbolic objects. A hierarchical clustering has two steps in general: find out step and update step. In the find out step, we find the nearest pair of clusters. We extend it for distribution valued dissimilarities, introducing a measure on their order relations. In the update step, dissimilarities between clusters are redefined by mixture of distributions with a mixing ratio. We show an actual example of the proposed method and a simulation study.