• Journal of Intelligence and Information Systems
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• v.24 no.2
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• pp.59-83
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• 2018

With the increasing importance of sentiment analysis to grasp the needs of customers and the public, various types of deep learning models have been actively applied to English texts. In the sentiment analysis of English texts by deep learning, natural language sentences included in training and test datasets are usually converted into sequences of word vectors before being entered into the deep learning models. In this case, word vectors generally refer to vector representations of words obtained through splitting a sentence by space characters. There are several ways to derive word vectors, one of which is Word2Vec used for producing the 300 dimensional Google word vectors from about 100 billion words of Google News data. They have been widely used in the studies of sentiment analysis of reviews from various fields such as restaurants, movies, laptops, cameras, etc. Unlike English, morpheme plays an essential role in sentiment analysis and sentence structure analysis in Korean, which is a typical agglutinative language with developed postpositions and endings. A morpheme can be defined as the smallest meaningful unit of a language, and a word consists of one or more morphemes. For example, for a word '예쁘고', the morphemes are '예쁘(= adjective)' and '고(=connective ending)'. Reflecting the significance of Korean morphemes, it seems reasonable to adopt the morphemes as a basic unit in Korean sentiment analysis. Therefore, in this study, we use 'morpheme vector' as an input to a deep learning model rather than 'word vector' which is mainly used in English text. The morpheme vector refers to a vector representation for the morpheme and can be derived by applying an existent word vector derivation mechanism to the sentences divided into constituent morphemes. By the way, here come some questions as follows. What is the desirable range of POS(Part-Of-Speech) tags when deriving morpheme vectors for improving the classification accuracy of a deep learning model? Is it proper to apply a typical word vector model which primarily relies on the form of words to Korean with a high homonym ratio? Will the text preprocessing such as correcting spelling or spacing errors affect the classification accuracy, especially when drawing morpheme vectors from Korean product reviews with a lot of grammatical mistakes and variations? We seek to find empirical answers to these fundamental issues, which may be encountered first when applying various deep learning models to Korean texts. As a starting point, we summarized these issues as three central research questions as follows. First, which is better effective, to use morpheme vectors from grammatically correct texts of other domain than the analysis target, or to use morpheme vectors from considerably ungrammatical texts of the same domain, as the initial input of a deep learning model? Second, what is an appropriate morpheme vector derivation method for Korean regarding the range of POS tags, homonym, text preprocessing, minimum frequency? Third, can we get a satisfactory level of classification accuracy when applying deep learning to Korean sentiment analysis? As an approach to these research questions, we generate various types of morpheme vectors reflecting the research questions and then compare the classification accuracy through a non-static CNN(Convolutional Neural Network) model taking in the morpheme vectors. As for training and test datasets, Naver Shopping's 17,260 cosmetics product reviews are used. To derive morpheme vectors, we use data from the same domain as the target one and data from other domain; Naver shopping's about 2 million cosmetics product reviews and 520,000 Naver News data arguably corresponding to Google's News data. The six primary sets of morpheme vectors constructed in this study differ in terms of the following three criteria. First, they come from two types of data source; Naver news of high grammatical correctness and Naver shopping's cosmetics product reviews of low grammatical correctness. Second, they are distinguished in the degree of data preprocessing, namely, only splitting sentences or up to additional spelling and spacing corrections after sentence separation. Third, they vary concerning the form of input fed into a word vector model; whether the morphemes themselves are entered into a word vector model or with their POS tags attached. The morpheme vectors further vary depending on the consideration range of POS tags, the minimum frequency of morphemes included, and the random initialization range. All morpheme vectors are derived through CBOW(Continuous Bag-Of-Words) model with the context window 5 and the vector dimension 300. It seems that utilizing the same domain text even with a lower degree of grammatical correctness, performing spelling and spacing corrections as well as sentence splitting, and incorporating morphemes of any POS tags including incomprehensible category lead to the better classification accuracy. The POS tag attachment, which is devised for the high proportion of homonyms in Korean, and the minimum frequency standard for the morpheme to be included seem not to have any definite influence on the classification accuracy.

• Asia pacific journal of information systems
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• v.20 no.3
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• pp.139-166
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• 2010

The supply chain management (SCM) systems have emerged as strong managerial tools for manufacturing firms in enhancing competitive strength. Despite of large investments in the SCM systems, many companies are not fully realizing the promised benefits from the systems. A review of literature on adoption, implementation and success factor of IOS (inter-organization systems), EDI (electronic data interchange) systems, shows that this issue has been examined from multiple theoretic perspectives. And many researchers have attempted to identify the factors which influence the success of system implementation. However, the existing studies have two drawbacks in revealing the determinants of systems implementation success. First, previous researches raise questions as to the appropriateness of research subjects selected. Most SCM systems are operating in the form of private industrial networks, where the participants of the systems consist of two distinct groups: focus companies and vendors. The focus companies are the primary actors in developing and operating the systems, while vendors are passive participants which are connected to the system in order to supply raw materials and parts to the focus companies. Under the circumstance, there are three ways in selecting the research subjects; focus companies only, vendors only, or two parties grouped together. It is hard to find researches that use the focus companies exclusively as the subjects probably due to the insufficient sample size for statistic analysis. Most researches have been conducted using the data collected from both groups. We argue that the SCM success factors cannot be correctly indentified in this case. The focus companies and the vendors are in different positions in many areas regarding the system implementation: firm size, managerial resources, bargaining power, organizational maturity, and etc. There are no obvious reasons to believe that the success factors of the two groups are identical. Grouping the two groups also raises questions on measuring the system success. The benefits from utilizing the systems may not be commonly distributed to the two groups. One group's benefits might be realized at the expenses of the other group considering the situation where vendors participating in SCM systems are under continuous pressures from the focus companies with respect to prices, quality, and delivery time. Therefore, by combining the system outcomes of both groups we cannot measure the system benefits obtained by each group correctly. Second, the measures of system success adopted in the previous researches have shortcoming in measuring the SCM success. User satisfaction, system utilization, and user attitudes toward the systems are most commonly used success measures in the existing studies. These measures have been developed as proxy variables in the studies of decision support systems (DSS) where the contribution of the systems to the organization performance is very difficult to measure. Unlike the DSS, the SCM systems have more specific goals, such as cost saving, inventory reduction, quality improvement, rapid time, and higher customer service. We maintain that more specific measures can be developed instead of proxy variables in order to measure the system benefits correctly. The purpose of this study is to find the determinants of SCM systems success in the perspective of vendor companies. In developing the research model, we have focused on selecting the success factors appropriate for the vendors through reviewing past researches and on developing more accurate success measures. The variables can be classified into following: technological, organizational, and environmental factors on the basis of TOE (Technology-Organization-Environment) framework. The model consists of three independent variables (competition intensity, top management support, and information system maturity), one mediating variable (collaboration), one moderating variable (government support), and a dependent variable (system success). The systems success measures have been developed to reflect the operational benefits of the SCM systems; improvement in planning and analysis capabilities, faster throughput, cost reduction, task integration, and improved product and customer service. The model has been validated using the survey data collected from 122 vendors participating in the SCM systems in Korea. To test for mediation, one should estimate the hierarchical regression analysis on the collaboration. And moderating effect analysis should estimate the moderated multiple regression, examines the effect of the government support. The result shows that information system maturity and top management support are the most important determinants of SCM system success. Supply chain technologies that standardize data formats and enhance information sharing may be adopted by supply chain leader organization because of the influence of focal company in the private industrial networks in order to streamline transactions and improve inter-organization communication. Specially, the need to develop and sustain an information system maturity will provide the focus and purpose to successfully overcome information system obstacles and resistance to innovation diffusion within the supply chain network organization. The support of top management will help focus efforts toward the realization of inter-organizational benefits and lend credibility to functional managers responsible for its implementation. The active involvement, vision, and direction of high level executives provide the impetus needed to sustain the implementation of SCM. The quality of collaboration relationships also is positively related to outcome variable. Collaboration variable is found to have a mediation effect between on influencing factors and implementation success. Higher levels of inter-organizational collaboration behaviors such as shared planning and flexibility in coordinating activities were found to be strongly linked to the vendors trust in the supply chain network. Government support moderates the effect of the IS maturity, competitive intensity, top management support on collaboration and implementation success of SCM. In general, the vendor companies face substantially greater risks in SCM implementation than the larger companies do because of severe constraints on financial and human resources and limited education on SCM systems. Besides resources, Vendors generally lack computer experience and do not have sufficient internal SCM expertise. For these reasons, government supports may establish requirements for firms doing business with the government or provide incentives to adopt, implementation SCM or practices. Government support provides significant improvements in implementation success of SCM when IS maturity, competitive intensity, top management support and collaboration are low. The environmental characteristic of competition intensity has no direct effect on vendor perspective of SCM system success. But, vendors facing above average competition intensity will have a greater need for changing technology. This suggests that companies trying to implement SCM systems should set up compatible supply chain networks and a high-quality collaboration relationship for implementation and performance.

• Journal of Food Hygiene and Safety
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• v.13 no.4
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• pp.441-447
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• 1998

This study was performed to investigate the changes of amount of S. typhimurium during cooking processes using pork and japchae (a Korean food which is made from meat, vegetables and noodles), and to support a practical application to develop a hazard analysis critical control point (HACCP) model. The pork was purchased in a retail shop, cut ($0.5\;cm\;{\times}\;10\;cm\;{\times}\;10\;cm$, 25 g), tested for Salmonella contamination (results: negative), inoculated with S. typhimurium ($10^{7}\;CFU/g$), then treated in various conditions related to cooking. Mter thawing for 24 hours in various conditions, the number of S. typhimurium was increased to $10^{10}\;CFU/g$ at a refrigerated temperature ($4~10^{\circ}C$), and to $10^{21}\;CFU/g$ at room temperature ($22~29^{\circ}C$). Mter thawing in a microwave oven for 40 seconds, the number of S. typhimurium increased to $10^{8}\;CFU/g$. During the thawing period, the number of S. typhimurium increased over time. At the refrigerated temperature, the number of the bacteria was $10^{10}\;CFU/g$ after 24 hours, $10^{13}\;CFU/g$ after 48 hours, and $10^{20}\;CFU/g$ after 72 hours. At room temperature the number of bacteria reached $10^{11}\;CFU/g$ in 2 hours, $10^{15}\;CFU/g$ in 4 hours, $10^{16}\;CFU/g$ in 8 hours, $10^{18}\;CFU/g$ in 12 hours, and $10^{21}\;CFU/g$ in 24 hours. Mter cooking in a frying pan (150{\pm}7^{\circ}C$) for 3 minutes, the bacterial count was $10^{16}\;CFU/g$. After cooking in hot water for 20 minutes, the bacterial count was $10^{7}\;CFU/g\;at\;60^{\circ}C,\;10^{6}\;CFU/g\;at\;63^{\circ}C,\;and\;10^{4}\;CFU/g\;at\;65^{\circ}C$. The fried pork was mixed with cooked vegetables, noodles, sesame oil, sesame seeds, and seasonings to make Korean japchae. This process took $10{\pm}2$ minutes. The bacterial count in the japchae increased to $10^{7}\;CFU/g$ from the count of $10^{6}\;CFU/g$ of the fried pork before it was mixed with the other ingredients. These results indicate that the amount of S. typhimurium is effected by various different cooking processes. This study can suggest that pork should be cooked in water at over $65^{\circ}C$ for 20 minutes in order to prevent food poisoning, if the pork is contaminated with S. typhimurium. The presence of S. typhimurium in the raw pork is identified in an HA for japchae, and the primary CCP for japchae is inadequate cooking (cooking method and time/temperature). We need to standardize time-temperature-size and amount of pork in cooking japchae, because pork is usually cooked in ordinary frying pans when we make this food.

• Journal of Intelligence and Information Systems
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• v.23 no.4
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• pp.169-196
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• 2017

The fourth industrial revolution represents a revolutionary change in the business environment and its ecosystem, which is a fusion of Information Technology (IT) and other industries. In line with these recent changes, the Ministry of Employment and Labor of South Korea announced 'the Fourth Industrial Revolution Leader Training Program,' which includes five key support areas such as (1) smart manufacturing, (2) Internet of Things (IoT), (3) big data including Artificial Intelligence (AI), (4) information security, and (5) bio innovation. Based on this program, we can get a glimpse of the South Korean government's efforts and willingness to emit leading human resource with advanced IT knowledge in various fusion technology-related and newly emerging industries. On the other hand, in order to nurture excellent IT manpower in preparation for the fourth industrial revolution, the role of educational institutions capable of providing high quality IT education services is most of importance. However, these days, most IT educational institutions have had difficulties in providing customized IT education services that meet the needs of consumers (i.e., learners), without breaking away from the traditional framework of providing supplier-oriented education services. From previous studies, it has been found that the provision of customized education services centered on learners leads to high satisfaction of learners, and that higher satisfaction increases not only task performance and the possibility of business application but also learners' recommendation intention. However, since research has not yet been conducted in a comprehensive way that consider both antecedent and consequent factors of the learner's satisfaction, more empirical research on this is highly desirable. With the advent of the fourth industrial revolution, a rising interest in various convergence technologies utilizing information technology (IT) has brought with the growing realization of the important role played by IT-related education services. However, research on the role of IT education service quality in the context of IT education is relatively scarce in spite of the fact that research on general education service quality and satisfaction has been actively conducted in various contexts. In this study, therefore, the five dimensions of IT education service quality (i.e., tangibles, reliability, responsiveness, assurance, and empathy) are derived from the context of IT education, based on the SERVPERF model and related previous studies. In addition, the effects of these detailed IT education service quality factors on learners' educational satisfaction and their work application/recommendation intentions are examined. Furthermore, the moderating roles of learner position (i.e., practitioner group vs. manager group) and participation motivation (i.e., voluntary participation vs. involuntary participation) in relationships between IT education service quality factors and learners' educational satisfaction, work application intention, and recommendation intention are also investigated. In an analysis using the structural equation model (SEM) technique based on a questionnaire given to 203 participants of IT education programs in an 'M' IT educational institution in Seoul, South Korea, tangibles, reliability, and assurance were found to have a significant effect on educational satisfaction. This educational satisfaction was found to have a significant effect on both work application intention and recommendation intention. Moreover, it was discovered that learner position and participation motivation have a partial moderating impact on the relationship between IT education service quality factors and educational satisfaction. This study holds academic implications in that it is one of the first studies to apply the SERVPERF model (rather than the SERVQUAL model, which has been widely adopted by prior studies) is to demonstrate the influence of IT education service quality on learners' educational satisfaction, work application intention, and recommendation intention in an IT education environment. The results of this study are expected to provide practical guidance for IT education service providers who wish to enhance learners' educational satisfaction and service management efficiency.

• Journal of Global Scholars of Marketing Science
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• v.18 no.2
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• pp.65-88
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• 2008

Since the implementation of economic reforms in 1978, the Chinese economy grows rapidly at an average annul growth rate of 9% over the post two decades. Franchising has been widely recognized as an important source of entrepreneurial activity. Trust is important in that it facilitates relational exchanges by permits partners to transcend short-run inequities or risks to concentrate on long-term profits or gains. In the relationship between the franchisors and franchisees, trust has been described as an important source of competitive advantage. However, little research has been done on the factors affecting trust in Chinese franchisor-franchisee relationships. The purpose of this study is to investigate what factors affect the trust in the franchise system in China, and to provide guidelines and insights to franchisors which enter Chinese market. In this study, according to Morgan and Hunt (1994), trust is defined as the extending when one party has confidence in an exchange partner's reliability and integrity. We offered a conceptual model of the empirical study. The model shows that the factors affecting the trust include franchisor's supports, communication, satisfaction with previous outcome and conflict. We also suggested the franchisor's supports and communication like to enhance the franchisee's satisfaction with previous outcome, and the franchisor's supports, communication and he franchisee's satisfaction with previous outcome tend to decrease conflict. Before the formal study, a pretest involving exploratory interviews with owners from three franchisees was conducted to make sure the questionnaire was relevant and clear to the respondents. The data were collected using trained interviewers to carry out personal interviews with the aid of an unidentified, muti-page, structured questionnaire. The respondents comprised of owners, managers, and owner managers of franchisee-owned food service franchises located in Beijing, China. Even though a total of 256 potential franchises were initially contacted, the finally usable sample consisted of 125 respondents. As expected, the sampling method was successful in soliciting respondents with waried personal and firm characteristics. Self-administrated questionnaires were used for all measures. And established scales were used to measure the latent constructs in this study. The measures tapped the franchisees' perceptions of the relationship with the referent franchisor. Five-point Likert-type scales ranging from "strongly disagree" (=1) to "strongly agree" (=7) were used throughout the constructs (trust, eight items; support, five items; communication, four items; satisfaction, six items; conflict, three items). The reliability measurements traditionally employed, such as the Cronbach's alpha, were used. All the reliabilities were greater than.80. The proposed measurement model was estimated using SPSS 12.0 and AMOS 5.0 analysis package. We conducted A series of exploratory factor analyses and confirmatory factor analyses to assess the convergent validity, discriminant validity, and reliability. The results indicate reasonable overall fits between the model and the observed data. The overall fit of measurement model were $X^2$= 159.699, p=0.004, d.f. = 116, GFI =.879, NFI =.898, CFI =.969, IFI =.970, TLI =.959, RMR =.058. The results demonstrated that the data reasonably fitted the model. We also examined construct reliability and reliability and average variance extracted (AVE). The construct reliability of each construct was greater than.80 and the AVE of each construct was greater than.50. According to the analysis of Structure Equation Modeling (SEM), the results of path model indicated an adequate fit of the model: $X^2$= 142.126, p = 0.044, d.f. = 115, GFI =.892, NFI =.909, CFI =.981, IFI =.981, TLI =.974, RMR =.057. As hypothesized, the results showed that it is strategically important to establish trust in a franchise system, and the franchisor's supports, communication and satisfaction with previous outcome tend to reinforce franchisee's trust. The results also showed trust seems to decrease as the experience of conflict episodes increases. And we also noticed that franchisor's supports and communication tend to enhance the franchisee's satisfaction with previous outcome, and communication tend to decrease conflict. If the trust between the franchisor and franchisee can be established in a franchise system, franchising offers many benefits and reduces many costs. To manage a mutual trust of relationship with their franchisees, franchisor's should provide support effectively to their franchisees. Effective assistant services have direct effect on franchisees' satisfaction with previous outcome and trust in franchisor. Especially, franchise sales process, orientation, and training in the start-up period are key elements for success of the franchise system. Franchisor's support is an accumulated separate satisfaction evaluation with different kind of service provided by the franchisor. And providing support definitely can improve the trustworthy image of the franchisor. In the franchise system, conflicts of interests and exertions of different power sources are very common. The experience of conflict episodes seems to negatively relate to trust. Therefore, it is important to reduce the negative side of the relationship conflicts. Communication actually plays a broader role in reducing conflict and establish mutual trust in franchisor-franchisee relationship. And effective communication between franchisors and franchisees can improve franchisees' satisfaction toward the franchise system. As the diversification of Chinese markets, both franchisors and franchisees must keep the relevant, timely, and reliable communication. And it is very important to improve the quality of communication. Satisfaction with precious outcomes seems to positively relate to trust. Franchisors and franchisees that are highly satisfied with the previous outcomes that flow from their relationship will perceive their partner as advancing their goal achievement. Therefore, it is necessary for both franchisor and their franchisees to make the welfare of partner with effort. Little literature has focused on what factors affect the trust between franchisors and their franchisees in China. This study developed the hypotheses regarding the factors affecting trust in the transaction relationship. The results of data analysis supported the hypotheses strongly. There are certain limitations in this study. First, we may point out that some other factors missed in this study could be significantly important. Second, the context of this study, food service industry, limits its potential generalizability for all franchise systems. More studies in different categories of franchise system are needed to broaden its generalizability. Third, the model was tested empirically in a sample in Beijing, more empirical tests of the proposed model in other Chinese areas are needed. Finally, the analysis in this study was solely based on the perception of franchisees and the opinions of franchisors were not included.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.4
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• pp.14-23
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• 2014

The purpose of this study is to contribute in building credibility of the methodology of the appearance of the traditional colors and the interpretation of the meaning of those appearances by analyzing the spatial construction and configuration and the traditional colors that appear in spatial elements about the scenery component that appear in Seyeonjeong. We conducted a literature research about the traditional colors, the background of the creation of Seyeonjeong, and etc. For the contents for the empirical analysis, we took the scenery and space elements in the poems, such as Eobusasisa and O-u-ga, and the contents of poems related to ojeongsaek (five Korean traditional colors) based on the Yin-Yang and the Five Elements ideology Particularly, after dividing the spatial elements appearing in Seyoenjeong into visual, synesthetic, symbolic/cognitive spatial element, we further distinguished the visual space into positions and directions of the of the spaces and the scenery of the season; the synesthetic space into seasons, time and five senses; and the symbolic/cognitive space into chiljeong (or the seven passions) and sadan (or the four clues). Then we carried out the study by analyzing the correlation between the intention of the garden creation and the meaning of the spaces, through the analysis of ojeongsaek system for each spatial element. Firstly, spatial structure and format that appear in Seyeonjeong can be divided into two directional axes of southeast and northwest according to the flat form of the Seyeongjeong's rectangular palace, with Seyeongjoeng as the center. Secondly, in spatial component element, the frequencies of appearance of the traditional colors of Seyoenjeong are 33.2% for white, 20.8% for blue, 20.8% for black, 18.7% for red and 6.3% for yellow. Thirdly, based on the analysis of the traditional colors the most frequent appearance of 'white' left a room for interpretation like the creation of Seyeonjeong was to enjoy secular living without lingering political feelings so that the high mountains remain clear and clean. Also, the predominant frequency of appearance of blue, similar frequency of appearance of black and red, and the least frequent appearance of yellow is in agreement with or can be at least interpreted related to Yun Seon-do's intention for creating Seyeonjeong not for political rank or power but as a place to enjoy nature, through which he can build on his knowledge, and to lead rest of his life as a noble being through plays, like dancing and writing poems. Fourthly, these interpretations of the analysis of the frequency of appearance of the traditional colors of Seyeongjong shows the reliability, validity, and consistency of the methodology of the analysis of the frequency of appearance of the traditional colors and the interpretation of the meanings in the context that the color white appears most frequently in Soswewon as well and that the background life of the Soswewon's creator Yangsanbo can be interpreted in a similarly way. Above all, this study is significant from the fact that we proposed a theory about the method of analysis and interpretation of the traditional colors in a traditional landscape space. Moreover, there is a great significance of discovering that traditional colors appear in traditional spaces and this can be used as a methodological framework to interpret things like, intention for creation of (buildings/architectures).

• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.217-227
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• 2006

Micronutrient status in soils and crops of plastic film house and their relationship were investigated. Total 203 plastic film houses were selected (red pepper, 66; cucumber, 63; tomato, 74) in Yeongnam region and soil and leaf samples were collected. Hot-water extractable B and 0.1 N HCl extractable Cu, Zn, Fe, and Mn in soil samples and total micronutrients in leaf samples were analyzed. Contents Zn, Fe, and Mn in most of the investigated soils were higher than the upper limits of optimum level for general crop cultivation. Contents of Cu in most soils of cucumber and tomato cultivation were higher than the upper limit of optimum level, but Cu contents in about 30% of red pepper cultivation soils were below the sufficient level. Contents of B in most soils of cucumber and tomato were above the sufficient level but in 48% of red pepper cultivation soils B were found to be deficient. Micronutrient contents in leaf of investigated crops were much variable. Contents of B, Fe, and Mn were mostly within the sufficient levels, while in 71% of red pepper samples Cu was under deficient level and in 44% of cucumber samples Cu contents were higher than the upper limit of sufficient level. Contents of Zn in red pepper and cucumber samples were mostly within the sufficient level but in 62% of tomato samples Zn contents were under deficient condition. However, any visible deficiency or toxicity symptoms of micronutrients were not found in the crops. No consistent relationships were found between micronutrient contents in soil and leaf, and this indicates that growth and absorption activity of root and interactions among the nutrients in soil might be important factors in overall micronutrient uptake of crops. For best management of micronutrients in plastic film house, much attention should be focused on the management of soil and plant characteristics which control the micronutrient uptake of crops.

• Journal of the Mineralogical Society of Korea
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• v.20 no.1 s.51
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• pp.47-60
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• 2007

While sedimentological researches on Western coastal tidal flats of Korea have been much pelformed previously, mineralogical and biogeochemical studies are beginning to be studied. The objectives of this study were to investigate mineralogical characteritics of the inter-tidal flat sediments and to explore phase transformation of iron(oxyhydr)oxides and biomineralization by metal-reducing bacteria enriched from the inter-tidal flat sediments from Muan, Jeollanam-do, Korea. Inter-tidal flat sediment samples were collected in Chungkye-myun and Haeje-myun, Muan-gun, Jeollanam-do. Particle size analyses were performed using the pipette method and sedimentation method. The separates including sand, silt and clay fractions were examined by scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), and X-ray diffiaction (XRD). After enriching the metal-.educing bacteria from the into,-tidal flat sediments, the bacteria were used to study phase transformation of the synthesized iron (oxyhydr)oxides and iron biomineralization using lactate or glucose as the electron donors and Fe(III)-containing iron oxides as the electron accepters. Mineralogical studies showed that the sediments of tidal flats in Chung]rye-myun and Haeje-myun consist of quartz, plagioclase, microcline, biotite, kaolinite and illite. Biogeochemical researches showed that the metal-reducing bacteria enriched from the inter-tidal flat sediments reduced reddish brown akaganeite and mineralized nanometer-sized black magnetite. The bacteria also reduced the reddish brown ferrihydrite into black amorphous phases and reduced the yellowish goethite into greenish with formation of nm-sized phases. These results indicate that microbial Fe(III) reduction may play one of important roles in iron and carbon biogeochemistry as well as iron biomineralization in subsurface environments.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.67-74
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• 2015

In recent years, frequent itemset mining for considering the importance of each item has been intensively studied as one of important issues in the data mining field. According to strategies utilizing the item importance, itemset mining approaches for discovering itemsets based on the item importance are classified as follows: weighted frequent itemset mining, frequent itemset mining using transactional weights, and utility itemset mining. In this paper, we perform empirical analysis with respect to frequent itemset mining algorithms based on transactional weights. The mining algorithms compute transactional weights by utilizing the weight for each item in large databases. In addition, these algorithms discover weighted frequent itemsets on the basis of the item frequency and weight of each transaction. Consequently, we can see the importance of a certain transaction through the database analysis because the weight for the transaction has higher value if it contains many items with high values. We not only analyze the advantages and disadvantages but also compare the performance of the most famous algorithms in the frequent itemset mining field based on the transactional weights. As a representative of the frequent itemset mining using transactional weights, WIS introduces the concept and strategies of transactional weights. In addition, there are various other state-of-the-art algorithms, WIT-FWIs, WIT-FWIs-MODIFY, and WIT-FWIs-DIFF, for extracting itemsets with the weight information. To efficiently conduct processes for mining weighted frequent itemsets, three algorithms use the special Lattice-like data structure, called WIT-tree. The algorithms do not need to an additional database scanning operation after the construction of WIT-tree is finished since each node of WIT-tree has item information such as item and transaction IDs. In particular, the traditional algorithms conduct a number of database scanning operations to mine weighted itemsets, whereas the algorithms based on WIT-tree solve the overhead problem that can occur in the mining processes by reading databases only one time. Additionally, the algorithms use the technique for generating each new itemset of length N+1 on the basis of two different itemsets of length N. To discover new weighted itemsets, WIT-FWIs performs the itemset combination processes by using the information of transactions that contain all the itemsets. WIT-FWIs-MODIFY has a unique feature decreasing operations for calculating the frequency of the new itemset. WIT-FWIs-DIFF utilizes a technique using the difference of two itemsets. To compare and analyze the performance of the algorithms in various environments, we use real datasets of two types (i.e., dense and sparse) in terms of the runtime and maximum memory usage. Moreover, a scalability test is conducted to evaluate the stability for each algorithm when the size of a database is changed. As a result, WIT-FWIs and WIT-FWIs-MODIFY show the best performance in the dense dataset, and in sparse dataset, WIT-FWI-DIFF has mining efficiency better than the other algorithms. Compared to the algorithms using WIT-tree, WIS based on the Apriori technique has the worst efficiency because it requires a large number of computations more than the others on average.

• Journal of the Korean Geographical Society
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• v.31 no.2
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• pp.295-308
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• 1996

1. Retrospect of Political Geographic Studies since Liberation, 1945 : 1) Period from 1945 to mid 1960s : There was not political geography as a science in Korea at the time of liberation from Japan 1945. At that time were not pure political geographers in Korea. In 1947, Moon-Hwa Pyo, economics professor, published a book titled Outline of Korean Geopolitics. This book was a first one in the field of political geography and available at that time in the logical descriptions. Bok-Hyon Choi was a first political geographer who in 1959 wrote a book titled Political geography for the collegians of Seoul National University. Professor Choi introduced American-style political geography through the book above mentioned. In 1963, Kie-Joo Hyong published an article titled "Korean Unification: Possibility from the Geopolitical Viewpoint" which was a first article published by Korean young scholar who studied geography in this country. 2) Period from late 1960s to late 1980s : Both Yoon Cha and Duck-Soon Im published frequently several articles of political geography or geopolitics respectively in 1968-1969. And they issued geopolitical disputes on Korean geopolitical structure and an application of rimland theory to Korean peninsula in 1969 through a magazine named Joung-Kyong Younku (the political and economic researches). The disputes played an important role of showing political geography (or geopolitics) to political sciences especially international political Science. Active researches still continued in 1970s. In that atmosphere the first Korean book of political geography written by a post-liberation scholar (Duck-Soon Im) titled Principles of Political Geography was published in 1973. This book was influenced much by American political geography after Second World War. In 1980s, the researches continued more actively. Especially administrative districts, capital cities, and sub-capital cities were frequently studied during this period. 3) Period from late 1980s to Present: Recent Studies : 1985 was a year of much production of articles of political geography. The first Ph.D thesis of political geography published in the same year in our country. And since 1985 produced many M.A. articles. Several categories of esearches of political geography was made in the period from late 1980s to present. Capital cities, Korean unification, administrative districts, urban politics, elections, sub-capital cities, and defense walls were important research categories. Reviewing the researches from 1945 to present. I found eight categories of political geography in Korea: capital cities, administrative districts, geopolitical structure of Korean peninsula, division and unification of Korea, sub-capital cities, defense walls, elections, and urban politics. Each category includes several scholars respectiveiy. 2. Study Tasks and Prospects in Korean Political Geography: In relation to Korean circumstances there are three study-tasks. The first task of Korean people is unification of two Koreas. Political geographers of Korea must al survey titled Survey Methods of Human Geography for collegians. This book was first one on survey part in Korea. The book however, is insufficient in comprehensiveness in aspects too. I think that the important tasks of general-synoptic human geography in Korea are \circled1 publication of comprehensive books of human geography in the aspects and methodologies for collegians and \circled2 acceptance of academic world of human geography in Korea of variety in methodologies of human geography for future progress. progress.