• Communications of the Korean Mathematical Society
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• v.16 no.3
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• pp.459-485
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• 2001

The aim of EIT (electrical impedance tomography) system is to image cross-section conductivity distribution of a human body by means of both generating and sensing electrodes attached on to the surface of the body, where currents are injected and voltages are measured. EIT has been suffered from the severe ill-posedness which is caused by the inherent low sensitivity of boundary measurements to any changes of internal tissue conductivity values. With a limited set of current-to-voltage data, figuring out full structure of the conductivity distribution could be extremely difficult at present time, so it could be worthwhile to extract some necessary partial information of the internal conductivity. We try to extract some key patterns of current-to-voltage data that furnish some core information on the conductivity distribution such s location and size. This overview provides our recent observation on the location search and the size estimation.

• Asia pacific journal of information systems
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• v.32 no.3
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• pp.514-536
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• 2022

Online reviews offer valuable information to businesses by reflecting consumer experiences about their products and services. Two crucial aspects of online reviews are the topics consumers choose to address, and the sentiments expressed in their reviews. Building upon previous literature that shows online reviews are context-dependent, we employ the Expectation-Confirmation Theory (ECT) to examine the impact of topic distribution on review sentiment in South Korea and the U.S. during pre- and post-pandemic periods. After applying a topic modeling to Airbnb app review data, we measure the contribution of each topic on review sentiment using SHAP values. Our results indicate variations in topic distribution trends between 2018 and 2021. In addition, the order and magnitude of topics' impact on review sentiment change between pre- and post-pandemic periods for both countries. This study can help businesses understand how topics and sentiments associated with their products and services changed after the pandemic and thus identify areas of improvement.

• Journal of Information Technology Applications and Management
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• v.15 no.3
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• pp.79-90
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• 2008

With the corporate environment nowadays being surrounded by plenty of information, the sharing of information among businesses through mutual cooperation tops the list of hot issues. Predictions of demands from the customer, business, or consumer by sharing information can affect the inventory and order production system. However, notwithstanding the importance of sharing information, empirical studies on quantitative use of information still remain insufficient in spite of many a discussion now being made on the sharing of information. This paper proposes to examine the ways meteorological information may affect the rises in the achievements of supply chains in distributive businesses, the kind of information that noticeably affects the consumer behavioral patterns in the distributive businesses but rarely perceived as a form of information shared by businesses. This study is based on a model in which meteorological information has been added as the one used to predict demands, after the beer distribution game has been modified to fit the current status, and simulations under an assumptive situation, where decisions are made on a daily basis, were conducted 50 times for a period of 1000 days for the generalization of the results, while at the same time a Duncan Test was conducted to determine the threshold to use the meteorological information that will be most profitable to the retailer, wholesaler, supplier and the supply chain as a whole. Our findings indicate that corporations have thresholds that vary from business to business depending upon the ratio of backlog costs to inventory costs. At the same time, our findings also show that there existed effective thresholds depending upon the ratio of backlog costs to inventory costs for the performance of the overall supply chain.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.2
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• pp.1-16
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• 2020

The current status of geographical distribution range of Deutzia paniculata, one of the korean endemic plants, was investigated based on the species distribution information. The information of the geographical range used for analysis includes all the published references to the distribution of D. paniculata, herbarium specimens in Korea National Arboretum (KH) including its online database: http://www.nature.go.kr, and field research. Although, D. paniculata was firstly recorded in Wonsan, Hamgyeongnam-do, North Korea, this research revelaved that D. paniculata is mainly distributed in Gyeongsangbuk-do and Gyeongsangnam-do, southern regions of the Korean Peninsula. According to the distribution map, this species was estimated on distribution edge of in Anyang region of Gyeonggi-do, Mt. Naejang of Jeollabuk-do and Mt. Taebaek of Gwangwon-do on the distribution edge. However, it was made use of intensive field survey to identify the natural population of the species in these regions. D. paniculata habitat was mainly distributed between 290 meters and 491 meters in altitude, but it was also found ranged from 936 to 959 meters in Gun-wi, Gyeongsangbuk-do, South Korea. The distribution slope was 5° to 35° and the north, N, NE and NW in the aspect. The flora of vascular plants in D. paniculata habitats was listed in 137 taxa: 54 families, 103 genera, 120 species, 2 subspecies, 12 varieties and 3 forms while Korean endemic plants were found in three taxa, Stewartia koreana, Weigela subsessilis and D. Paniculata. Based on a collection of non-biological environment and biological environment data, D. paniculata population were discussed to make strategy and basic research methods for sustainable preservation.

• Spatial Information Research
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• v.16 no.3
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• pp.359-372
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• 2008

This research estimated Pinus densiflora distribution and suggested an optimal grid size of DEM for ecologically better explaining spatial distribution and appearance pattern of Pinus densiflora and analyze appearance frequency of Pinus densiflora by topographical factors. And this work ultimately aimed at topographically analyzing spatial distribution of Pinus densiflora by comparing impact of topographical factors. The aspect was analyzed in detail, east, west, south, north, from DEM with 1m grid size, and simply, east, west, south or east, south from DEM with bigger grid size. As a result of distribution of Pinus densiflora by aspect, Pinus densiflora appeared in all aspect with smaller grid size, while distribution in specific aspect decreased with bigger grid size. The analysis of appearance frequency with 100m grid size represented spatial distribution characteristics of Pinus densiflora as visual interpretation showed. The results of comparing impact of aspect, slope, TWI proved that aspect have more impact on distribution of Pinus densiflora than slope and there was not enough a difference between impact of slope and TWI.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.825-833
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• 2013

An estimation of confidence intervals is essential to calculate uncertainty for greenhouse gases inventory. It is generally assumed that the population has a normal distribution for the confidence interval of parameters. However, in case data distribution is asymmetric, like nonnormal distribution or positively skewness distribution, the traditional estimation method of confidence intervals is not adequate. This study compares two estimation methods of confidence interval; parametric and non-parametric method for exponential distribution as an asymmetric distribution. In simulation study, coverage probability, confidence interval length, and relative bias for the evaluation of the computed confidence intervals. As a result, the chi-square method and the standardized t-bootstrap method are better methods in parametric methods and non-parametric methods respectively.

• International Commerce and Information Review
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• v.14 no.2
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• pp.3-27
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• 2012

As Chinese political and economical status gets higher, a lot of multinational firms have tried to find some chances from the Chinese market successfully. Though geographically Korea is located closely to China, a lot of firms entering into Chinese market have turned out failed. Thus, this study researched Korean manufacturing firms in China, surveyed their localization degree of distribution, and tried to find out factors which influence these localization from a far-reaching literature. As a result of analyzing 146 questionnaires, the length of channel, among Chinese environmental factors, has a positive influence on the distribution localization degree. In addition, the factor of distribution relation assets has a positive effect on the distribution localization degree. Considering this study, the Chinese market, especially distribution field, has recently grown up to the world-class level. Therefore a firm intending to enter into China needs to be careful not to underestimate China.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.6
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• pp.159-169
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• 2020

A cold chain logistics (CCL) model for chilled food (-1℃ to 8℃) distributed in China was developed in this study. The CCL model consists of a distribution center (DC) and distribution target points (DT). The objective function of the CCL model is to minimize the total distribution routes of all distributors. To find the optimal result of the objective function, the hybrid genetic algorithm (HGA) approach is proposed. The HGA approach was constructed by combining the improved K-means and genetic algorithm (GA) approaches. In the case study, three scenarios were considered for the CCL model based on the distribution routes and the available distance, and they were solved using the proposed HGA approach. Analysis results showed that the distribution costs and mileage were reduced by approximately 19%, 20% and 16% when the proposed HGA approach was used.

• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.23-45
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• 2012

The objective of this study is to provide development strategies in the production and distribution system of highland Chinese cabbage by evaluating and analyzing problems of the current system, focusing on several main stages between production and distribution system of highland Chinese cabbage. Through interview of groups such as farmers, distributers in the main producing areas, commission merchants of the wholesale market and large-scale distributors the relavant information was collected. Also, data such as production situations in main producing areas, distribution conditions in the wholesale market was analyzed. The functions of highland Chinese cabbage were classified and the current state of highland Chinese cabbage distribution system was investigated to provide an overall insight into the highland Chinese cabbage distribution system. Also the factors which will affect a price of wholesale market and consumer of highland Chinese cabbage were examined. Finally problems and improvements in the production and distribution system through analysis of the distribution system of highland Chinese cabbage were provided. the main contents of this study are as follows. The first is to keep stability of production in main producing areas by applying a differentiated production method, for example, rainshelter cultivation method. The second is to establish the distribution system which the relevant information is opened transparently. The third is that the consistent cold transportation system from main producing areas to consumers must be built.

• Communications for Statistical Applications and Methods
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• v.21 no.4
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• pp.297-307
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• 2014

We derive a test statistic for the general linear test in the ridge regression model. The exact distribution for the test statistic is too difficult to derive; therefore, we suggest an approximate reference distribution. We use numerical studies to verify that the suggested distribution for the test statistic is appropriate. A asymptotic result for the test statistic also is considered.