• ETRI Journal
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• v.43 no.1
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• pp.74-81
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• 2021

The mixture model is a very powerful and flexible tool in clustering analysis. Based on the Dirichlet process and parsimonious Gaussian distribution, we propose a new nonparametric mixture framework for solving challenging clustering problems. Meanwhile, the inference of the model depends on the efficient online variational Bayesian approach, which enhances the information exchange between the whole and the part to a certain extent and applies to scalable datasets. The experiments on the scene database indicate that the novel clustering framework, when combined with a convolutional neural network for feature extraction, has meaningful advantages over other models.

• Journal of Distribution Science
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• v.16 no.10
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• pp.65-76
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• 2018

Purpose - This paper investigates how the market value of the firms are impacted by distribution information technology investment in Korea over time and across markets, industries and project characteristics. This is the first empirical study on the market payoffs from the RFID investment in Korea. The purpose of this study is to provide a appropriate guideline for investors and practitioners with respect to the announcement representing RFID adoption in Korea. This reaction guideline will stimulate the practitioners to monitor and evaluate the benefits and costs of the innovative RFID technology. Research design, data, and methodology - This paper employs event study methodology to analyze the payoffs from distribution information technology investment announcements over a fifteen-year period from 2003 to 2017. Event study method is based on the assumptions such as market efficiency, unanticipated RFID invest announcements and no confounding effects in the data. This study collected the information on RFID investment announcements by using a full text search engine Bigkinds provided by Korea Press Foundation over a fifteen-year period from January 2003 through December 2017. This paper selected 88 announcements representing RFID adoption by 46 firms. This paper estimated the payoffs from RFID investment announcement through events windows by using the market model of Mcwilliams and Siegel (1997) and calculated the Z-values. Using this test statistics we could infer if RFID adoption make large differences in abnormal returns across various classifications of the firms. Results - There is significant positive market returns from the announcement representing distribution information technology investment in the pre-2009 time period, the significances of payoffs disappear in the post-2009 time period. For this reason investors or practitioners can understand the importance of market entry time and the fact that the greater rewards may belong to early innovators while late imitators cannot reap such a rewards. This paper also find that there is a large differences in the payoffs from the announcement across markets, industries and project characteristics. Conclusions - Analysing the selected sample of 88 announcements representing RFID Adoption over fifteen-year period from 2003 to 2017, this study find that there is not only significant abnormal excess returns from RFID investment announcements but also there is great differences in the abnormal returns over time and across firm sizes or affiliated markets, industries, and project characteristics. This means that there are considerable values for the investors across various firm classifications. The findings of this paper provide useful implications for the practitioners to make judicious decisions whether to adopt the innovative technologies in general or not considering the various concrete circumstances in Korea.

• Journal of the Korean Regional Science Association
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• v.14 no.1
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• pp.127-141
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• 1998

The purpose of this paper is to present an informatization stratagem for a balanced development around the whole country by employing Regional Information Index. In order to demonstrate the region information level by applying the factor analysis in the study, it has been divided into three catagories, such as the generation of information, the distribution of information, and the consumption of information. According to the empirical analysis between 1985 and 1995, the regional differences of the levels of the consumption and the distribution of information have been reduced gradually. On the other hand, the generation of information is significantly concentrated around Seoul Metropolitan Area. Therefore, strategic efforts providing information infrastructures as well as introducing information industries associated with informatization will guarantee a balanced development around the country.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1760-1766
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• 2009

Digital broadcasting and digital CATV and IPTV will continue in the competition, regardless of how the content of the program was broadcast over the Internet distribution and the damage of piracy is also growing. Excellent quality of the content of the digital CATV sales of DVD and high-density storage media because there is no difference in content and quality is the problem of illegal distribution. However, users can record and reuse program in the position of the guaranteed rights, and the purpose of training in fair and illegal recording and distribution needs to be separate from it. In this paper using a digital certificate recorded by the user and the process to ensure the purpose of illegal distribution of pharmaceutical distribution system design and implementation of the program was broadcast.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.167-174
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• 2016

The Korean distribution line currently consists of overhead ground wires (OHGW), overhead distribution lines, neutral wires (NW), and messenger wires (MW). The MW is installed under the NW. The lightning protection system in Korea is focused on OHGW and lightning arrester and the MW are not considered. Therefore, this paper proposes the applicability of MW for purpose of lightning protection. For this, we analyzed the effects of lightning overvoltage according to the existence of OHGW and MW and the grounding conditions of the MW in the Korean distribution system. The grounding conditions of the MW that we took into consideration were the common or separate grounding of the MW and NW. The analysis based on the equivalent circuit of the distribution pole at each condition was performed. The distribution lines and lightning were modeled using the Electromagnetic Transients Program (EMTP). For each of the installation conditions of the OHGW and MW, the various lightning conditions were simulated and analyzed for both direct and indirect lightning. The simulation results showed that, if the OHGW was not installed in the Korean distribution system, the lightning overvoltage could be reduced by the common grounding of the MW and NW.

• Journal of the Korean Society for information Management
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• v.24 no.4
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• pp.255-265
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• 2007

In this paper we analyzed regularity of daily patterns of distribution of Queries coming from internet search engine. And then, we proposed a Pareto distribution and Zipf law for identifying the query distribution and applied them to daily queries on the search engine during 2 week. We found that there is some evidence that Pareto and Zipf laws can be applied to evaluate the regularity of daily patterns of distribution of queries in search engine. Those results can be used to provide a better understanding of the social interests and trends using the query distribution patterns.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.105-107
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• 2015

In this paper, we proposed LTD(Load Tolerance Density-distribution) algorithm using dynamic density for analyzing distribute routing path. MANET(Mobile Ad-hoc Networks) consists of the node that has a mobility. By the Mobility, the topology is exchanged frequently. To reduce the exchange of topology, the hierarchy network is studied. However, if the load is concentrated at the cluster head node, the communication is disconnected. the proposed algorithm measure the dynamic density of the node using poisson distribution. And this algorithm provides distribute routing path using dynamic density. The simulation results, the proposed algorithm shows improved packet delivery ratio than the compared algorithm.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.3
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• pp.1-9
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• 2014

The inverse Rayleigh model distribution and Rayleigh distribution model were widely used in the field of reliability station. In this paper applied using the finite failure NHPP models in order to growth model. In other words, a large change in the course of the software is modified, and the occurrence of defects is almost inevitable reality. Finite failure NHPP software reliability models can have, in the literature, exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, proposes the inverse Rayleigh and Rayleigh software reliability growth model, which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination($R^2$), for the sake of efficient model, were employed. In order to insurance for the reliability of data, Laplace trend test was employed. In many aspects, Rayleigh distribution model is more efficient than the reverse-Rayleigh distribution model was proved. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can helped.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.4
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• pp.193-203
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• 2012

This study analyzed regular transportation costs between port warehouses and processing plants and between processing plants and central distribution centers and further transportation costs relations according to empty transfer rates in each circulation by examining the distribution routes of imported grain including wheat, barley, corn, and soybean, namely port warehouses, processing plants, and central distribution centers. Based on the results, the study compared and reviewed the logistics transportation costs. The analysis results of the alternative model show that logistics operational costs could be considerably cut down by introducing a flexible vehicle transportation operational method, which is to change the vehicle loading parts for proper substitute transportation after unloading and transport them to other locations such as central distribution centers instead of returning empty, as an alternative to high operational costs deriving from empty vehicle operation in each circulation after unloading items in case of transportation of imported grain and processed items. The results allow for a more realistic approach to general problems with large-scale distribution network operation and provide a theoretical foundation to serve as a guide to establish policies for corporate operation of imported grain logistics systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.12A
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• pp.1828-1835
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• 2000

In this paper, we analyzed the other-cell interference characteristics for various non-uniform traffic distributions and their effects on the capacity of multi-cell CDMA system. We consider three different traffic distributions, i.e., linear, exponential and Gaussian traffic distribution with distribution parameters. Changing the distribution parameter, we can obtain the center-focused distributions or uniform distributions for each model. From the results of other-cell interference calculation we can see that the other-cell interference decreases, as the user concentrates on the base station. Also using frequency reuse efficiency indicating the capacity reduction of a multi-cell system when compared to a single cell system, we evaluate the effect of traffic distribution on the reverse link CDMA capacity. For linear case, the capacity of multi-cell system is reduced to 0.637∼0.867 times that of single cell system. On the other hand, for both exponential and Gaussian cases, the capacity under a multi-cell environment is equal to 70∼100% of that under a single cell. Therefore, we conclude that the average capacity of multi-cell CDMA system are increased when users are likely to be at near the cell base station due to reduced total other-cell interference and decreased when users exist at near the cell edge regardless of traffic distribution models.