• Journal of Environmental Policy
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• v.10 no.4
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• pp.3-37
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• 2011

This paper investigates the existence of the environmental Kuznets curve (EKC) for carbon dioxide $CO_2$ emissions and its causal relationships with economic growth and openness by using time series data (1971-2006) from China (an emerging market), Korea (a newly industrialized country), and Japan (a developed country). The sample countries span a whole range of development stages from industrialized to newly industrialized and emerging market economies. The environmental consequences according to openness and economic growth do not show uniform results across the countries. Depending on the national characteristics, the estimated EKC show different temporal patterns. China shows an N-shaped curve while Japan has a U-shaped curve. Such dissimilarities are also found in the relationship between $CO_2$ emissions and openness. In the case of Korea, and Japan it represents an inverted U-shaped curve while China shows a U-shaped curve. We also analyze the dynamic relationships between the variables by adopting a vector auto regression or vector error correction model. These models through the impulse response functions allow for analysis of the causal variable's influence on the dynamic response of emission variables, and it adopts a variance decomposition to explain the magnitude of the forecast error variance determined by the shocks to each of the causal variables over time. Results show evidence of large heterogeneity among the countries and variables impacts.

• Journal of dental hygiene science
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• v.11 no.5
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• pp.411-416
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• 2011

Streptococcus mutans (S. mutans) is the major causative bacteria in dental caries. Xylitol is effective anticarious natural sugar substitute by inhibiting the virulence of S. mutans. However, long-term xylitol consumption leads to the emergence of the xylitol-resistant (XR) strains which means xylitol is no more inhibited their growth. We therefore confirmed the general characteristics and the virulence factors of the xylitol-sensitive (XS) and XR S. mutans for different concentrations of xylitol. S. mutans KCTC 3065 was maintained in TYE medium containing 0.4% glucose with 1% xylitol during 30 days at $37^{\circ}C$, 10% $CO_2$ to form XR strain. The strains were transferred to new medium every 24 hr and the same procedures without xylitol were repeated for the formation of XS S. mutans. Both XS and XR were cultured in different concentrations of xylitol (0%, 0.1% and 1%) then, cell growth, acid production and mRNA expression of gtf genes were analyzed. Xylitol reduced the cell growth of XS S. mutans in dose-dependent manner, but not reduced that of XR. Xylitol inhibited acid production of XS in dose-dependent manner, but not inhibited that of XR. Xylitol reduced the gtfB and gtfD mRNA expression of XS S. mutans which genes synthesized soluble and insoluble extracellular polysaccharides, but not reduced that of XR. These results indicate that the virulence of XR S. mutans is different characters of XS strains, which suggests XR strains may have different cariogenicity of XS strains. Further study is needed to explain the mechanism related to extracellular polysaccharide in the XR strains.

• Journal of the Economic Geographical Society of Korea
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• v.4 no.2
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• pp.57-77
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• 2001

The Honam region has been recognized as one of the most lagging regions in Korea. Drawing upon some decompositions oi Gross Regional Domestic Product(GRDP) per head and labor productivity, the overall trend of inequalities in Korea has been revealed and the trajectory of the Honam region's economic change has been identified by examining how the region's economic performance changed relative to that of Korea in the 1990s. There are some findings. First of all, Korea is characterized by strong divergence in the development of its region economies, in terms o\ulcorner per capita GRDP, which relies upon productivity differentials rather than differences in employment rates. Second, the Honam region has displayed poor economic performances in terms of GRDP per head except for Jeonnam. Third, the dramatic fall in cumulative population growth relative to the national average has been an important factor in the Jeonnam's overwhelming economic performance measured by per capita GRDP. Fourth, the decline in the relative productivity of the Honam region is mostly explained by falling relative regional productivity growth in construction, transport and manufacturing, although it should be noted that the latter sector has made positive contribution to raising relative regional productivity of Jeonnam. Fifth, overall the shift in employment to service sector, especially to social, personal, public, health, education, other services other than distribution, hotels, catering has tended to support relative regional productivities, along with the positive contribution being made oi agriculture, forestry and fishing to relative regional productivity growth in the Honam region.

• Journal of KIISE
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• v.44 no.3
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• pp.314-322
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• 2017

In MMORPG (Massively Multiplayer Online Role-Playing Game), users advance their own characters to get to the maximum (max) level by performing given tasks in the game scenario. Although it is crucial to retain users with high levels for running online games successfully, little efforts have been paid to investigate them. In this study, by analyzing approximately 60 million in-game logs of over 50,000 users, we aimed to investigate the process through which users achieve the max level and churn of such users since the moment of achieving the max level, and determine possible indicators related to churn after the max level. Based on the result, we can predict churn of the max level users by employing behavioral patterns before the max level. Moreover, we found users who are socially active and communicate with many people before the max level are less likely to leave the service (p<0.05). This study supports that communication patterns are important factors for persistent usage of the users who achieve the max level, which has practical implications to guide elite users on enjoying online games in the long run.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.6
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• pp.531-536
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• 2002

In this paper, we have applied Genetic Algorithms(GAs) to Intrusion Detection System(TDS), and then proposed and simulated the misuse detection model firstly. We have implemented with the KBD contest data, and tried to simulated in the same environment. In the experiment, the set of record is regarded as a chromosome, and GAs are used to produce the intrusion patterns. That is, the intrusion rules are generated. We have concentrated on the simulation and analysis of classification among the Data Mining techniques and then the intrusion patterns are produced. The generated rules are represented by intrusion data and classified between abnormal and normal users. The different rules are generated separately from three models "Time Based Traffic Model", "Host Based Traffic Model", and "Content Model". The proposed system has generated the update and adaptive rules automatically and continuously on the misuse detection method which is difficult to update the rule generation. The generated rules are experimented on 430M test data and almost 94.3% of detection rate is shown.3% of detection rate is shown.

• The Journal of Society for e-Business Studies
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• v.14 no.2
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• pp.41-56
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• 2009

The purpose of this paper is to present a statistical model that can predict the rapid shift of users' attention by analyzing the lifecycle patterns of news in a social news aggregation service. Internet news service sites have a distinct characteristic in a sense that users' attention change very quickly in a short period of time. In this research, we propose a regression model for each news category which can model the decay pattern of users' attention and the content promotion policy of a social news aggregator is proven to be a major source of the rapid growth in the popularity of news. The proposed model is expected to be useful for evaluation of the social news aggregation service provider's content promotion policy that attempts to maximize users' attention as well as the diversity of news contents.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.372-380
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• 2010

Generally, data mining is the process of analyzing data from different perspectives and summarizing it into useful information that can be used to increase revenue, cuts costs, or both. It allows users to analyze data from many different dimensions or angles, categorize it, and summarize the relationships identified. Technically, data mining is the process of finding correlations or patterns among dozens of fields in large relational databases. Data mining is one of the fastest growing field in the computer industry. Because of According to computer technology has been improving, Massive customer data has stored in database. Using this massive data, decision maker can extract the useful information to make a valuable plan with data mining. Data mining offers service providers great opportunities to get closer to customer. Data mining doesn't always require the latest technology, but it does require a magic eye that looks beyond the obvious to find and use the hidden knowledge to drive marketing strategies. Automotive market face an explosion of data arising from customer but a rate of increasing customer is getting lower. therefore, we need to determine which customer are profitable clients whom you wish to hold. This paper builds model of customer loyalty detection and analyzes customer buying patterns in automotive market with data mining using decision tree as a quinlan C4.5 and basic statics methods.

• Journal of Korea Multimedia Society
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• v.8 no.9
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• pp.1163-1176
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• 2005

The Web is the largest distributed information space but, the individual's capacity to read and digest contents is essentially fixed. In these Web environments, mining traversal patterns is an important problem in Web mining with a host of application domains including system design and information services. Conventional traversal pattern mining systems use the inter-pages association in sessions with only a very restricted mechanism (based on vector or matrix) for generating frequent K-Pagesets. We extend a family of novel algorithms (termed WebPR - Web Page Recommend) for mining frequent traversal patterns and then pageset to recommend. We add a WebPR(A) algorithm into a family of WebPR algorithms, and propose a new winWebPR(T) algorithm introducing a window concept on WebPR(T). Including two extended algorithms, our experimentation with two real data sets, including LadyAsiana and KBS media server site, clearly validates that our method outperforms conventional methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.404-414
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• 2020

This study aims to explore latent classes in terms of changing patterns in achievement motivation among the samples from elementary school to middle school students in multicultural families and to investigate factors to predict latent groups and their relationship with academic achievement. 1254 pairs of mother and child from the 1st to 6th years of Multicultural Adolescents Panel Study (MAPS) was utilized for the Latent Class Growth Analysis (LCGA), One-way ANOVA, Multinomial Logistic Regression. The results showed that there were four distinct subgroups within the samples in terms of achievement goal orientations (i.e. very-high changing group, average changing group, low stable group, very-low stable group) at all six time points, and students who reported high achievement motivation were likely to have higher academic achievement. Four groups were extracted based on parent's efficacy, students' self-esteem, and teacher's support. Suggestions and practical implications for understanding the types of subgroups for the achievement motivation of multicultural families were discussed.

• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1055-1060
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• 2005

Purpose : The purpose of this study is to compare the growth pattern of breast fed and formula fed infants in the first 1 year of life. Methods : Anthropometric data(weight, length, head circumference) of at birth, 1, 3, 6, 9 and 12 months were collected by chart review and characteristics of subjects were collected by questionnaires. Among 358 infants, breast fed infants were 161(84 males, 77 females) and formula fed infants were 90(42 males, 48 females). Neither group was given solid foods before 4 months. The weight for age, length for age and head circumference for age were calculated. Breast fed infants were separated into 2 groups(breast fed for 4-11 months and breast fed for more than 12 months). Results : Characteristics of infants and mothers were similar in both groups except for maternal age. Mean weight of breast fed group was lower than that of formula fed group at 12 months of age(male : P=0.004, female : P=0.004). However, mean weight of 12 months breast fed group was below formula fed groups weight at 9 and 12 months(P<0.05). Mean length and head circumference were similar between groups. Conclusion : The growth indices of breast fed and formula fed infants are similar at birth, but weight curves of two groups differ in the first 1 year.