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Financial Fraud Detection using Text Mining Analysis against Municipal Cybercriminality (지자체 사이버 공간 안전을 위한 금융사기 탐지 텍스트 마이닝 방법)

  • Choi, Sukjae;Lee, Jungwon;Kwon, Ohbyung
    • Journal of Intelligence and Information Systems
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    • v.23 no.3
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    • pp.119-138
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    • 2017
  • Recently, SNS has become an important channel for marketing as well as personal communication. However, cybercrime has also evolved with the development of information and communication technology, and illegal advertising is distributed to SNS in large quantity. As a result, personal information is lost and even monetary damages occur more frequently. In this study, we propose a method to analyze which sentences and documents, which have been sent to the SNS, are related to financial fraud. First of all, as a conceptual framework, we developed a matrix of conceptual characteristics of cybercriminality on SNS and emergency management. We also suggested emergency management process which consists of Pre-Cybercriminality (e.g. risk identification) and Post-Cybercriminality steps. Among those we focused on risk identification in this paper. The main process consists of data collection, preprocessing and analysis. First, we selected two words 'daechul(loan)' and 'sachae(private loan)' as seed words and collected data with this word from SNS such as twitter. The collected data are given to the two researchers to decide whether they are related to the cybercriminality, particularly financial fraud, or not. Then we selected some of them as keywords if the vocabularies are related to the nominals and symbols. With the selected keywords, we searched and collected data from web materials such as twitter, news, blog, and more than 820,000 articles collected. The collected articles were refined through preprocessing and made into learning data. The preprocessing process is divided into performing morphological analysis step, removing stop words step, and selecting valid part-of-speech step. In the morphological analysis step, a complex sentence is transformed into some morpheme units to enable mechanical analysis. In the removing stop words step, non-lexical elements such as numbers, punctuation marks, and double spaces are removed from the text. In the step of selecting valid part-of-speech, only two kinds of nouns and symbols are considered. Since nouns could refer to things, the intent of message is expressed better than the other part-of-speech. Moreover, the more illegal the text is, the more frequently symbols are used. The selected data is given 'legal' or 'illegal'. To make the selected data as learning data through the preprocessing process, it is necessary to classify whether each data is legitimate or not. The processed data is then converted into Corpus type and Document-Term Matrix. Finally, the two types of 'legal' and 'illegal' files were mixed and randomly divided into learning data set and test data set. In this study, we set the learning data as 70% and the test data as 30%. SVM was used as the discrimination algorithm. Since SVM requires gamma and cost values as the main parameters, we set gamma as 0.5 and cost as 10, based on the optimal value function. The cost is set higher than general cases. To show the feasibility of the idea proposed in this paper, we compared the proposed method with MLE (Maximum Likelihood Estimation), Term Frequency, and Collective Intelligence method. Overall accuracy and was used as the metric. As a result, the overall accuracy of the proposed method was 92.41% of illegal loan advertisement and 77.75% of illegal visit sales, which is apparently superior to that of the Term Frequency, MLE, etc. Hence, the result suggests that the proposed method is valid and usable practically. In this paper, we propose a framework for crisis management caused by abnormalities of unstructured data sources such as SNS. We hope this study will contribute to the academia by identifying what to consider when applying the SVM-like discrimination algorithm to text analysis. Moreover, the study will also contribute to the practitioners in the field of brand management and opinion mining.

Dynamic forecasts of bankruptcy with Recurrent Neural Network model (RNN(Recurrent Neural Network)을 이용한 기업부도예측모형에서 회계정보의 동적 변화 연구)

  • Kwon, Hyukkun;Lee, Dongkyu;Shin, Minsoo
    • Journal of Intelligence and Information Systems
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    • v.23 no.3
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    • pp.139-153
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    • 2017
  • Corporate bankruptcy can cause great losses not only to stakeholders but also to many related sectors in society. Through the economic crises, bankruptcy have increased and bankruptcy prediction models have become more and more important. Therefore, corporate bankruptcy has been regarded as one of the major topics of research in business management. Also, many studies in the industry are in progress and important. Previous studies attempted to utilize various methodologies to improve the bankruptcy prediction accuracy and to resolve the overfitting problem, such as Multivariate Discriminant Analysis (MDA), Generalized Linear Model (GLM). These methods are based on statistics. Recently, researchers have used machine learning methodologies such as Support Vector Machine (SVM), Artificial Neural Network (ANN). Furthermore, fuzzy theory and genetic algorithms were used. Because of this change, many of bankruptcy models are developed. Also, performance has been improved. In general, the company's financial and accounting information will change over time. Likewise, the market situation also changes, so there are many difficulties in predicting bankruptcy only with information at a certain point in time. However, even though traditional research has problems that don't take into account the time effect, dynamic model has not been studied much. When we ignore the time effect, we get the biased results. So the static model may not be suitable for predicting bankruptcy. Thus, using the dynamic model, there is a possibility that bankruptcy prediction model is improved. In this paper, we propose RNN (Recurrent Neural Network) which is one of the deep learning methodologies. The RNN learns time series data and the performance is known to be good. Prior to experiment, we selected non-financial firms listed on the KOSPI, KOSDAQ and KONEX markets from 2010 to 2016 for the estimation of the bankruptcy prediction model and the comparison of forecasting performance. In order to prevent a mistake of predicting bankruptcy by using the financial information already reflected in the deterioration of the financial condition of the company, the financial information was collected with a lag of two years, and the default period was defined from January to December of the year. Then we defined the bankruptcy. The bankruptcy we defined is the abolition of the listing due to sluggish earnings. We confirmed abolition of the list at KIND that is corporate stock information website. Then we selected variables at previous papers. The first set of variables are Z-score variables. These variables have become traditional variables in predicting bankruptcy. The second set of variables are dynamic variable set. Finally we selected 240 normal companies and 226 bankrupt companies at the first variable set. Likewise, we selected 229 normal companies and 226 bankrupt companies at the second variable set. We created a model that reflects dynamic changes in time-series financial data and by comparing the suggested model with the analysis of existing bankruptcy predictive models, we found that the suggested model could help to improve the accuracy of bankruptcy predictions. We used financial data in KIS Value (Financial database) and selected Multivariate Discriminant Analysis (MDA), Generalized Linear Model called logistic regression (GLM), Support Vector Machine (SVM), Artificial Neural Network (ANN) model as benchmark. The result of the experiment proved that RNN's performance was better than comparative model. The accuracy of RNN was high in both sets of variables and the Area Under the Curve (AUC) value was also high. Also when we saw the hit-ratio table, the ratio of RNNs that predicted a poor company to be bankrupt was higher than that of other comparative models. However the limitation of this paper is that an overfitting problem occurs during RNN learning. But we expect to be able to solve the overfitting problem by selecting more learning data and appropriate variables. From these result, it is expected that this research will contribute to the development of a bankruptcy prediction by proposing a new dynamic model.

A Protection Management Characteristic and Preservation Plan of World Heritage Mt. Huangshan (세계유산 황산의 보호관리 특성 및 보전방안)

  • Shin, Hyun-Sil
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.36 no.1
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    • pp.120-128
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    • 2018
  • The purpose of this study is to establish basic data for the continuous protection management policy of domestic natural world heritage and mixed world heritage, and to examine the present situation and characteristics of the protection management according to the World Heritage Convention on the World Heritage listed Huangshan. The results of this study are as follows. First, Huangshan began to be protected by the establishment of the Huangshan Construction Committee in 1933, and after the designation of national park in 1982, laws and regulations were established in the central ministries, And various projects related to utilization have been implemented. Secondly, the establishment of the boundary for protection was actively intervened by the central government, such as the reorganization of the boundary of Huangshan through the administrative district plan. In order to protect the ecological and landscape value as well as the cultural factor, And designated a heritage designated area. Third, the protection management of Huangshan was divided into four major stages. The first phase was divided into the period when administrative measures were taken to manage the protection of Huangshan. The second phase was designated as a national park in Huangshan. The third period was the time of the protection-oriented project according to the recommendation of the international organizations after the World Heritage listed. The fourth period was the expansion of the tourism industry for the continuous use of protection of Huangshan city, My preservation business was being implemented. Fourth, Huangshan is managed by the central government and the city government. Huangshan, which is a mixed heritage, is managed jointly by the Ministry of Cultural Heritage Administration and the Ministry of Natural Heritage Administration. The protection and management of Huangshan promoted the efficiency and expertise of the heritage-related work through the establishment of the administrative unit-specific management system, and the local governments were entrusted with the authority to implement the protection management policies that meet local characteristics. Fifth, the preservation area of Huangshan has been destroyed by the development policy centered on the mountain. In addition, according to the operation of accommodation facilities, there are problems such as sewage, garbage disposal, and environmental pollution caused by tourists, and the damage caused by pests and diseases in planted plantations around the area and changes in ecosystem due to the composition of cable cars. Sixth, for the continuous protection of Huangshan, strict regulations on new construction, extension and management of accommodation are required, and it is necessary to install facilities to limit and control the number of visitors.

CONFOCAL LASER SCANNING MICROSCOPIC MORPHOLOGY OF DENTIN-RESIN INTERFACE AND ITS RELATIONSHIP WITH SHEAR BOND STRENGTH (상아질-레진 계면의 공초점 현미경적 형태 및 전단결합강도와의 관계)

  • Choi, Nak-Won;Cho, Byeong-Hoon;Son, Ho-Hyun
    • Restorative Dentistry and Endodontics
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    • v.24 no.2
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    • pp.310-321
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    • 1999
  • In this in vitro study, confocal laser scanning microscopic morphology of dentin-resin interface and its relationship to shear bond strength were investigated after the exposed dentin surfaces were treated with 3 different kinds of dentin adhesive systems[three-step; Scotchbond Multi-Purpose Plus(SMPP), self-priming bonding resin; Single Bond(SB), self-etching primer; Clearfil Liner Bond 2(LB2)]. 52 extracted human molar teeth without caries and/or restorations. The experimental teeth were randomly divided into three groups of seventeen teeth each. In five teeth of each group, class V cavities(depth: 1.5mm) with 900 cavosurface angles were prepared at the cementoenamel junction on buccal and lingual surfaces. Bonding resins of each dentin adhesive system were mixed with rhodamine B. Primer of SMPP was mixed with fluorescein. In group 1. the exposed dentin was conditioned with etchant, applied with above primer and bonding resin of SMPP. In group 2, with etchant and self-priming bonding agent of SB. In group 3, with self-etching primer and bonding agent of LB2. After treatment with dentin adhesive systems, composite resin were applied and photocured. The experimental teeth were cut longitudinally through the center line of restoration and grounded so that about $90{\mu}m$-thick wafers of buccolingually orientated dentin were obtained. And, $70{\sim}80{\mu}m$-thick wafers sectioned horizontally, thus presenting a dentinal tubules at 900 to the cut surface of a remaining tooth, were obtained. Primer of SMPP mixed with rhodamine B was applied to these wafers. Confocal laser scanning microscopic investigations of these wafers were done within of 24 hours after treatment. To measure shear bond strength, the remaining twelve teeth of each group were grounded horizontally below the dentinoenamel junction, so that no enamel remained. After applying dentin adhesive systems on the dentin surface, composite was applied in the shape of cylinder. The cylinder was 5mm in diameter, and 2mm in thickness. Shear bond strength was measured using Instron with a cross-head speed of 0.5mm/min. It was concluded as follows ; 1. Hybrid layer of SMPP(mean: $4.56{\mu}m$) was thicker than that of any other groups. This value was not statistically significant thicker than that of SB(mean: $3.41{\mu}m$, p>0.05), and significant thicker than that of LB2(mean: $1.56{\mu}m$, p<0.05). There was a statistical difference between SB and LB2(p<0.05). 2. Although there were variations in the length of resin tag even in a sample, and in a group, most samples in SMPP and SB showed resin tags extending above $20{\mu}m$. But samples in LB2 showed resin tags of $10{\mu}m$ at best. 3. Besides primer's infiltration into demineralized peritubular dentin and dentinal tubules, fluorophore of primer was detected in the lateral branches of dentinal tubules. 4. All groups demonstrated statistically significant differences from one another(p<0.05), with shear bond strengths given in descending order as follows: SMPP(18.3MPa), SB(16.0MPa) and LB2(12.4MPa). 5. LB2 having thinnest hybrid layer($1.56{\mu}m$) showed the lowest shear bond strength(12.4MPa).

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Hightechnology industrial development and formation of new industrial district : Theory and empirical cases (첨단산업발전과 신산업지구 형성 : 이론과 사례)

  • ;Park, Sam Ock
    • Journal of the Korean Geographical Society
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    • v.29 no.2
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    • pp.117-136
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    • 1994
  • Contemporary global space economy is so dynamic that any one specific structural force can not explain the whole dynamic processes or trajectories of spatial industrial development. The major purpose of this paper is extending the traditional notion of industrial districts to functioning and development of new industrial districts with relation to the development of high technology industries. Several dynamic forces, which are dominated in new industrial districts in the modern space economy, are incorporated in the formation and dynamic aspects of new industrial districts. Even though key forces governing Marshallian industrial district are localization of small firms, division of labor between firms, constructive cooperation, and industrial atmosphere, Marshall points out a possibility of growing importance of large firms and non-local networks in the districts with changes of external environments. Some of Italian industrial districts can be regarded as Marshallian industrial districts in broader context, but the role of local authorities or institutions and local embeddedness seem to be more important in the Italian industrial districts. More critical implication form the review of Marshallian industrial districts and Italian industrial districts is that the industrial districts are not a static concept but a dynamic one: small firm based industrial districts can be regarded as only a specific feature evolved over time. Dynamic aspects of new industrial districts are resulting from coexistence of contrasting forces governing the functioning and formation of the districts in contemporary global space economy. The contrasting forces governing new industrial districts are coexistence of flexible and mass production systems, local and global networks, local and non-local embeddedness, and small and large firms. Because of these coexistence of contrasting forces, there are various types of new industrial districts. Nine types of industrial districts are identified based on local/non-local networks and intensity of networks in both suppliers and customers linkages. The different types of new industrial districts are described by differences in production systems, embeddedness, governance, cooperation and competition, and institutional factors. Out of nine types of industrial districts, four types - Marshallian; suppliers hub and spoke; customers hub and spoke; and satellite - are regarded as distinctive new industrial districts and four additional types - advanced hub and spoke types (suppliers and customers) and mature satellites (suppliers and customers) - can be evolved from the distinctive types and may be regarded as hybrid types. The last one - pioneering high technology industrial district - can be developed from the advanced hub and spoke types and this type is a most advanced modern industrial district in the era of globalization and high technology. The dynamic aspects of the districts are related with the coexistence of the contrasting forces in the contemporary global space economy. However, the development trajectory is not a natural one and not all the industrial districts can develop to the other hybrid types. Traditionally, localization of industries was developed by historical chances. In the process of high technology industrial development in contemporary global space economy, however, policy and strategies are critical for the formation and evolution of new industrial districts. It needs formation of supportive tissues of institutions for evolution of dyamic pattern of high technology related new industrial districts. Some of the original distinctive types of new industrial districts can not follow the path or trajectory suggested in this paper and may be declined without advancing, if there is no formation of supportive social structure or policy. Provision of information infrastructure and diffusion of an entrepreneurship through the positive supports of local government, public institutions, universities, trade associations and industry associations are important for the evolution of the dynamic new industrial districts. Reduction of sunk costs through the supports for training and retraining of skilled labor, the formation of flexible labor markets, and the establishment of cheap and available telecommunication networks is also regarded as a significant strategies for dynamic progress of new industrial districts in the era of high technology industrial development. In addition, development of intensive international networks in production, technology and information is important policy issue for formation and evolution of the new industrial districts which are related with high technology industrial development.

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The Brand Personality Effect: Communicating Brand Personality on Twitter and its Influence on Online Community Engagement (브랜드 개성 효과: 트위터 상의 브랜드 개성 전달이 온라인 커뮤니티 참여에 미치는 영향)

  • Cruz, Ruth Angelie B.;Lee, Hong Joo
    • Journal of Intelligence and Information Systems
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    • v.20 no.1
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    • pp.67-101
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    • 2014
  • The use of new technology greatly shapes the marketing strategies used by companies to engage their consumers. Among these new technologies, social media is used to reach out to the organization's audience online. One of the most popular social media channels to date is the microblogging platform Twitter. With 500 million tweets sent on average daily, the microblogging platform is definitely a rich source of data for researchers, and a lucrative marketing medium for companies. Nonetheless, one of the challenges for companies in developing an effective Twitter campaign is the limited theoretical and empirical evidence on the proper organizational usage of Twitter despite its potential advantages for a firm's external communications. The current study aims to provide empirical evidence on how firms can utilize Twitter effectively in their marketing communications using the association between brand personality and brand engagement that several branding researchers propose. The study extends Aaker's previous empirical work on brand personality by applying the Brand Personality Scale to explore whether Twitter brand communities convey distinctive brand personalities online and its influence on the communities' level or intensity of consumer engagement and sentiment quality. Moreover, the moderating effect of the product involvement construct in consumer engagement is also measured. By collecting data for a period of eight weeks using the publicly available Twitter application programming interface (API) from 23 accounts of Twitter-verified business-to-consumer (B2C) brands, we analyze the validity of the paper's hypothesis by using computerized content analysis and opinion mining. The study is the first to compare Twitter marketing across organizations using the brand personality concept. It demonstrates a potential basis for Twitter strategies and discusses the benefits of these strategies, thus providing a framework of analysis for Twitter practice and strategic direction for companies developing their use of Twitter to communicate with their followers on this social media platform. This study has four specific research objectives. The first objective is to examine the applicability of brand personality dimensions used in marketing research to online brand communities on Twitter. The second is to establish a connection between the congruence of offline and online brand personalities in building a successful social media brand community. Third, we test the moderating effect of product involvement in the effect of brand personality on brand community engagement. Lastly, we investigate the sentiment quality of consumer messages to the firms that succeed in communicating their brands' personalities on Twitter.

The Effect of PNF Technique application Using Thera-Band on the Balance and Gait of Females over 65 years old (세라밴드를 이용한 PNF 기법 적용이 65세 이상 여성노인의 균형과 보행에 미치는 영향)

  • Kang, Dal-Won;Kang, Mi-Kyoung;Kang, Eun-Sil;Go, Yu-Ri;Kim, Da-Woon;Kim, Dae-Yong;Kim, Jung-Eun;Kim, Won-Hwang;Kim, Ja-Yeon;Kim, Hwan;Jung, Dae-In;Kim, Myung-Hoon;Kim, Sang-Yup;Lee, Dong-Jin;Kim, Chan-Kyu;Kim, Hyun-Jin
    • Journal of Korean Physical Therapy Science
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    • v.18 no.1
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    • pp.1-10
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    • 2011
  • Purpose: Study on the effect of the use of Proprioceptive Neuromuscular Facilitation(PNF) method by use of the direction and charge regulation which is the advantage of the Thera-band therapy on the walks and balances in old people and comparison with the result after applying the general PNF technique. Method: The study has been performed on 30 females over 65 years old. The study has been done by dividing the object group in 3 patterns, which are number 1, the comparison group of 10, two ones that are applied the PNF technique using Thera-band and third, the ones that are applied only the PNF technique. For the PNF and the Thera-band using PNF, we have divided the group into Combination of Isotonic technique and the Rhythmical stabilization technique according to the patient's acquaintance pattern and applied them to the patient's body. Evaluation was the balancing ability which was calculated by using the BIODEX Balance system / FRT and for the evaluation of walking ability, we have used the speed of walking for 10M / TUG. Result: In the comparison group of 10, the balancing ability and the walking ability did not change much before and after the experiment, which made it possible to compare the group with the other two easily(p>0.05). For the other two groups, we have recognized the enhancement both in the balancing ability and the walking ability, but they did not know much difference between themselves(p<0.05). Conclusion: Though there were not a big difference in the sense of improvement between the Thera-band using PNF and the PNF technique only, we could infer that these two therapy has enhanced much in the walking and balancing ability for people over 65 and through these result we can foresee that not only using the method shown in this study but also by using many advantages of Thera-band, we could diminish the tiredness of healer, enhance the efficiency of exercise in them and also by forming self training program for older people we could help them build the prevention program from falls.

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Ecological Role of Urban Stream and Its Improvement (도시하천의 생태학적 역할과 개선방안)

  • Son, Myoung-Won
    • Journal of the Korean association of regional geographers
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    • v.4 no.1
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    • pp.15-25
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    • 1998
  • A stream plays an important role as the source of drinking water, the ecological space and the living space. But the today's urban stream whose ecosystem is destroyed and water quality become worse in consequence of covering, concrete dyke construction, and the adjustment of high-water-ground[dunchi], is deprived of the function as a stream. Therefore this paper aims to elucidate the role that urban stream plays ecologically and to try to find a improvement to the problem. A stream is the pathway through which several types of the solar radiation energy are transmitted and the place which is always full of life energy. In the periphery of a stream, primary productivity is high and carrying capacity of population is great. Thus ancient cities based on agricultural products grew out of the fertile surroundings of stream. In Korea most cities of the Chosen Dynasty Period based on the agriculture have grown out of the erosional basins where solar energy is concentrated. The role of a stream in this agricultural system is the source of energy and material(water and sediment) and a lifeline. In consequence of the growth of cities and the rapid growing demands of water supply after the Industrial Revolution, a stream has become a more important locational factor of city. However, because cities need the life energy of urban streams no longer, urban streams cannot play role as a lifeline. And As pollutant waste water has poured into urban streams after using external streams' water, urban streams have degraded to the status of a ditch. As the results of the progress of urbanization, the dangerousness of inundation of urban stream increased and its water quality became worse. For the sake of holding back it, local governments constructed concrete dyke, adjusted high-water-ground[dunchi], and covered the channel. But stream ecosystem went to ruin and its water quality became much worse after channelization. These problems of urban stream can be solved by transmitting much energy contained in stream to land ecosystem as like rural stream. We should dissipate most of the energy contained in urban stream by cultivating wetland vegetation from the shore of stream to high-water-ground, and should recover a primitive natural vigorous power by preparation of ecological park.

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Solid Waste Disposal Site Selection in Rural Area: Youngyang-Gun, Kyungpook (농촌지역 쓰레기 매립장 입지선정에 관한 연구 -경상북도 영양군을 사례로-)

  • Park, Soon-Ho
    • Journal of the Korean association of regional geographers
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    • v.3 no.1
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    • pp.63-80
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    • 1997
  • This study attempts to establish the criteria of site selection for establishing solid waste disposal facility, to determine optimal solid waste disposal sites with the criteria, and to examine the suitability of the selected sites. The Multi-Criteria Evaluation(MCE) module in Idrisi is used to determine optimal sites for solid waste disposal. The MCE combines the information from several criteria in interval and/or ratio scale to form a single index of evaluation without leveling down the data scale into ordinal scale. The summary of this study is as follows: First, the considerable criteria are selected through reviewing the literature and the availability of data: namely, percent of slope, fault lines, bedrock characteristics, major residential areas, reservoirs of water supply, rivers, inundated area, roads, and tourist resorts. Second, the criteria maps of nine factors have been developed. Each factor map is standardized and multiplies by its weight, and then the results are summed. After all of the factors have been incorporated, the resulting suitability map is multiplied by each of the constraint in turn to "zero out" unsuitable area. The unsuitable areas are discovered in urban district and its adjacencies, and mountain region as well as river, roads, resort area and their adjacency districts. Third, the potential sites for establishing waste disposal facilities are twenty five districts in Youngyang-gun. Five districts are located in Subi-myun Sinam-ri, nine districts in Chunggi-myun Haehwa-ri and Moojin-ri, and eleven districts in Sukbo-myun Posan-ri. The first highest score of suitability for waste disposal sites is shown at number eleven district in Chunggi-myun Moojin-ri and the second highest one is discovered at number twenty one district in Sukbo-myun Posan-ri that is followed by number nine district in Chunggi-myun Haehwa-ri, number seventeen and twenty three in Sukbo-myun Posan-ri, and number two in Subi-myun Sinam-ri. The first lowest score is found in number six district in Chunggi-myun Haehwa-ri, and the second lowest one is number five district in Subi-myun Sinam-ri. Finally, the Geographic Information System (GIS) helps to select optimal sites with more objectively and to minimize conflict in the determination of waste disposal sites. It is important to present several potential sites with objective criteria for establishing waste disposal facilities and to discover characteristics of each potential site as a result of that final sites of waste disposal are determined through considering thought of residents. This study has a limitation of criteria as a result of the restriction of availability of data such as underground water, soil texture and mineralogy, and thought of residents. To improve selection of optimal sites for a waste disposal facility, more wide rage of spatial and non-spatial data base should be constructed.

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Case Study of Hydrochemical Contamination by Antimony Waste Disposal in Korea (국내 안티몬폐기물에 의한 수질화학적 오염 사례연구)

  • Jeong, Chan-Ho
    • The Journal of Engineering Geology
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    • v.18 no.4
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    • pp.471-482
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    • 2008
  • This study was carried out to investigate the contamination characteristics of surface water, soil water and groundwater around and in antimony waste landfill site in Wonsung-ri, Yeonki-kun, Chungnam. The waste disposed in the study was excavated and transported to the other site in several years ago. For this study, we collected 35 water samples including groundwater, soil water and surface in the study site and also collected 2 groundwater samples from a comparison site. The data of chemical analysis of soil water samples show the antimony concentration of $48.75{\sim}74.81\;ppb$, which is much higher than groundwater in a comparison site and is highly excess than regulation level for a drinking water of some advanced countries. A relatively high antimony concentration was detected in three stream water samples nearby landfill site and two groundwater samples. Fe and Mn contents in soil water and stream water were measured as maxium 6.5 mg/L and 7.3 mg/L, respectively. Although other heavy metals of water samples in the study site are higher concentration than water sample of comparison site, their absolute levels are lower than regulation level for a drinking water. The chemical data of water samples are plotted widely from Ca - $HCO_3$ type to Ca - ($Cl +SO_4+NO_3$) type. Some groundwater show high contents of potassium and nitrate, which would come from fertilizer and sewage. Conclusively, some heavy metals including antimony have been still remained under the soil surface of the landfill site in the past. These metals have leaked out into nearby stream and groundwater system, and threaten the ecology, crops and the health of residents in this site. Therefore, the government have to prepare the strategy to prevent the diffusion of heavy metals into aquatic environment and have to process the reclamation work for contaminated site. It is also necessary to make a regulation level of the antimony concentration for a drinking water and soil environment in Korea.