• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.2
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• pp.54-61
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• 2016

Purpose Precocious Puberty is defined as the development of secondary sexual characteristics in girls younger than 8 years, and boys 9 years. Cause premature closure of the epiphysis is a disease that eventually decreases the final adult height. In this study, we retrospectively analyzed to evaluate the diagnostic difference the GnRH (Gonado-tropin-releasing Hormone) stimulation test results with medical records of precocious puberty in girls. Materials and Methods From February 2015 to December 2015 it was enrolled in the girls 118 people who visited the Seoul National University Bundang Hospital, Pediatrics, Endocrinology Internal Medicine. True precocious puberty group (n=57), early puberty group (n=39), were divided into Premature thelarche (n=22) group. A Tanner stage, chronological age, bone age, height, body weight for each group was determined by examining the mean${\pm}$standard deviation. GnRH test result was compared LH (Basal, 30 min, 45 min, 60 min), FSH (Basal, 30 min, 60 min) for each group, Each group LH, FSH Peak value distribution, the mean${\pm}$standard deviation was calculated for the peak LH/LH basal ratio, peak LH/Peak FSH ratio. The significance probability (P-value) between the value of each third group was determined. Results The average height of the true precocious puberty group $131{\pm}14.85$, the mean weight was $28.80{\pm}4.93$, the average chronological age $7.1{\pm}0.81$, the mean bone age was $9.9{\pm}0.9$, The average height of early puberty group was $134{\pm}5.10$, the average weight $28.50{\pm}4.43$, the average chronological age $8.05{\pm}0.03$, the mean bone age was $10.0{\pm}0.62$, The average height of Premature thelarche $129{\pm}6,01$, the average weight was $28.65{\pm}5.98$, the average chronological age $7.02{\pm}0.58$, the mean bone age was $8.04{\pm}1.29$. There was no significant difference when compared to the height and weight. There was a significant difference between the groups in the chronologic age and bone age difference (P <0.0002) True precocious puberty group showed peak LH levels at 30'(82.5%), 45'(12.3%), 60'(5.3%), in Peak FSH 30'(8.8%), 60'(91.2%). Early Puberty group showed high values in Peak LH at 30'(79.5%), 45'(17.9%), 60'(2.6%), in peak FSH levels at 30'(7.7%), 60'(92.32%). In Premature thelarche Group it showed the Peak LH levels at 30'(30%), 45'(59%), 60'(9.09%), Peak FSH levels at 30'(0%) 60'(100%). When compared with the The Peak LH/basal LH ratio, True precocious puberty group was $19.09{\pm}17.15$, early puberty group was $15.23{\pm}10.88$, Premature thelarche group showed significant differences between the three groups as $4.93{\pm}4.36$.(P <0.0001) LH Peak/FSH Peak ratio, true precocious puberty group was $1.222{\pm}0.77$, early puberty group was $1.34{\pm}1.23$, Premature thelarche group showed significant differences between the three groups as $0.3{\pm}0.09$(P <0.0001) Conclusion In order to diagnose the true precocious puberty have a diagnostic value when the LH peak after GnRH stimulation is increased by more than two to three times compared to baseline or a predetermined level or more than 5~10 IU/L increases. GnRH Test is a test for a long time and the patient discomfort due to repeated blood sampling, but the hypothalamus-pituitary gland- gonad axis activity evaluate and is the most basic accurate test in the differential diagnosis of precocious puberty disorders.

• Journal of Oral Medicine and Pain
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• v.32 no.1
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• pp.9-33
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• 2007

In the field of dentistry, there existed relatively few emergency patients or patients who need intensive care and thus had low medical dispute rates. However, these days, there is a general tendency of increased medical disputes. Although many medical disputes are caused by medical accidents of the dentists, because dental assistants are also lawfully involved in practicing dentistry, there is a possibility of medical disputes or medical accidents caused by dental assistants. Therefore, the role of the dental assistants cannot be ignored. This study consists of a survey given to dental hygienists currently working in general hospitals, dental hospitals and private dental clinics. Following is the results of the analysis of 275 respondents' backgrounds, medical disputes rates including patients' complaints, their understanding of medical regulations and their general understanding of overall dental practice and medical disputes. 1. 251 of 274(91.6%) respondents doubted the risk of medical accident and dispute. 2. 81(29.5%) dental hygienist experienced complaint from patients. They have been working in the private dental clinic, the rate of this experience was high. 3. 349 case of 1805(19.3%) the complaints by patients, highest percentage among its category, were those regarding dental fees and poor service. 4. 129 case of 1805(7.1%) patients' complaints, highest percentage among it's subcategory, were those regarding the absence of explanations of precautions or request of agreements before dental treatment. 5. 252 of 267 (94.4%) dental hygienists chart after a scaling treatment. However, only 55(20.7%) dental hygienists chart the fact of explaining the precautions. 6. 6(2.2%) dental hygienists do not inspect patients' medical history, if patients don't mention it. 7. 104 of 274(38.0%) dental hygienists responded to be capable of administering first aid treatment. 8. 115(41.8%) dental hygienists have a first aid kit and equipment. 9. In case of medical dispute, 268(97.8%) dental hygienists respond that, charting plays a big role in resolving the dispute. 10. In case of medical dispute, 272(93.3%) dental hygienists respond that, explanation and agreement before treatment have an important role in settlement of dispute 11. Only 160(58.4%) dental hygienists responded correct answer that the duration of keeping medical records is 10 years. 12. 124(45.3%) respondents thought that it is legal for a dental hygienist to take a panoramic dental X-ray, 71(25.9%) respondents thought that it is legal practice cervical resin treatment by dental hygienist, and 37(13.5%) respondents thought that it is legal extract primary teeth by dental hygienist. 13. 24(18.76%) respondents thought that it doesn't matter to tell patient's state to others 14. 272(99.27%) responded that receiving education for the prevention of medical disputes was needed and of them, 61.0% thought it was urgent. 15. 186(64.2%) has never had classes regarding the prevention of medical disputes while in school and 212(77.4%) has not had the same type of classes after graduating from school. 16. 256(93.4%) responded that there will be even more of an increased number of medical disputes. Among them, 83.3% of respondents though that due to the increased opportunity of acquiring information through the internet and mass media. The study shows that 29.5 percentage of dental hygienists have experienced the medical disputes and complaints and they are lack of recognition of medical regulations and dental hygienist's official duty. So, there is a big potential of the percentage to increase. Therefore, the correct understanding of explaining precautions and requesting agreement before dental treatments and performing them are mandatory. Moreover, classes regarding the prevention and counterplans of medical disputes need to be widely offered.

• 한국초등상담교육학회:학술대회논문집
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• 2004.01a
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• pp.223-245
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• 2004

The purpose of this study was to investigate the differences in depression, irrational faith and the school adaptation of elementary school students by their sex and region, to provide basic materials to teach children with the likelihood to be depressed by analyzing the correlation of depression, irrational faith and school adaptation, and help them to have healthy emotion and behaviors. To achieve these goals, following agenda were set. First, what are the differences in the depression, the irrational faith and the school adaptation of elementary school students by their sex and region? Second, what is the relationship between the depression characteristics and the irrational faith of elementary school students? Third, what is the relationship between the irrational faith and the school adaptation of elementary school students? Fourth, what is the relationship between the depression characteristics and school adaptation of elementary school students? : To resolve these agenda, the subjects were selected from Grade 6 students from the elementary schools locatec in Suwon and Hwaseong. The jubjects were selected from the two schools in Suwon and three schools in Hwaseong which were randomly chosen. The subjects were 670 in total. 70 insincere answers were excluded from the analysis. Therefore the subjects used in the analysis were 600 in total(150 male and female students in city respectively and 150 male and female students in rural area respectively). The tools used for this study were Children's Depression Inventory (CDI), Irrational Faith Test (over-self-reliance, dichotomy, determinism, over-concern, evasive faith, over dependent faith), School Adaptation Test (Attitudes to teachers and school environments, hobbies and specialties, academic achievements, peer relationship). Materials were processed with the SPSS program for ANOVA and correlation analysis. All the statistical values were verified at .05 level. The followings are the results of the analysis of the collected data. First, in the analysis of depression, there was significant difference between male and female students (F=4.75, p<.05). Female students (X =56.93) showed a little higher value than male students (X =53.83). There was significant difference between regions (F=13.02, p<.001), too. Rural area students (X =57.93) showed higher value than city area students (X =52.82). When analyzing irrational faith, there was significant difference between male and female students (F=S.60, p<.05). Female students (X =81.32) showed a little higher value than male students (X =77.72). There was no significant difference according to regions. When analyzing the school adaptation, there was no significant difference according to either sex or region. Second, depression and irrational faith showed highly positive correlations in all areas. In particular, over concern and evasive faith showed the highest correlation with depression inclination (r=.68, p<.001). When looking into the results by sex and by region, female students (r=.70, p<.001) and the rural area students (r=.69, p<.001) showed higher correlation between depression and irrational faith than male students and city area students (r=.63, p<.001). Additionally, in all areas including by sex and by region, a positive correlation was shown. In all variables such as male students (r=.63, p<.001), female students (r=.72, p<.001), city area students (r=.66, p<.001), and rural area students (r=.69, p<.001), over concern and evasive faith showed the highest correlation with depression inclinations. Third, irrational faith (overall) and its sub factors such as over-self-reliance, dichotomy, determinism, over-concern and evasive faith had significant negative correlations with school adaptation (overall) and its sub factors in the scope of $r=-.27{\sim}-.52$. Determinism out of the sub factors of the irrational faith had the highest negative correlation with school adaptation (overall) and sub factors at the scope of $r=-.37{\sim}-.51$. However, over-self-reliance showed the negative correlation with school adaptation (overall) and its sub factors only partially. When looking into the results by gender, both genders showed significant negative correlation between irrational faith (overall) and its sub factors with school adaptation. Male students showed highly negative correlations with school adaptation (overall) and its sub factors in determinism ($r=-.35{\sim}-52$) and over-concern and evasive faith($r=-.31{\sim}-.51$), and fern ale students showed in over-self-reliance ($r=-.27{\sim}-.45$). However over-self-reliance showed negative correlation with school adaptation and its sub factors only partially. When looking into by region, both city and rural areas showed significant negative correlation between irrational faith (overall) and it sub factors, and school adaptation. Rural areas showed higher negative correlation in irrational faith (overall) ($r=-.39{\sim}-.53$) and over-self-reliance ($r=-.32{\sim}-.44$) and dichotomy ($r=-.28{\sim}-.39$) than city areas. However over-self-reliance showed negative correlation with school adaptation and its sub factors only partially. Fourth, depression and school adaptation showed the negative correlation in all areas. In particular, academic achievements and peer relationship showed the highest negative correlation with depression (r=-.53 p<.001). When looking into the results by sex and by region, female students (r=-.62, p<.001) and rural area students (r=-.61, p<.001) showed higher negative correlation with depression and school adaptation than female students (r=-.56, p<.001) and city area students (r=-.57, p<.001). Although there was negative correlation in all areas by sex and by region, male students (r=-.52, p<.001) and rural area students (r=-.56, p<.001) showed the highest negative correlation in peer relationship and female students (r=-.57, p<.001) and city area students (r=-.56, p<.001) showed the highest negative correlation in academic records. Based on the results of the study, it is proposed to provide elementary school students sho are likely to be depressed very easily with careful counselling and teaching based on the attention and love in school fields so that they can adapt themselves to home, school and society with positive and reasonable thinking.

• Economic and Environmental Geology
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• v.39 no.4 s.179
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• pp.369-384
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• 2006

Korean Peninsula, located on the southeastern part of Eurasian plate, belongs to the intraplate region. The characteristics of intraplate earthquake show the low and rare seismicity and the sparse and irregular distribution of epicenters comparing to interplate earthquake. To evaluate the exact seismic activity in intraplate region, long-term seismic data including historical earthquake data should be archived. Fortunately the long-term historical earthquake records about 2,000 years are available in Korea Peninsula. By the analysis of this historical and instrumental earthquake data, seismic activity was very high in 16-18 centuries and is more active at the Yellow sea area than East sea area. Comparing to the high seismic activity of the north-eastern China in 16-18 centuries, it is inferred that seismic activity in two regions shows close relationship. Also general trend of epicenter distribution shows the SE-NW direction. In Korea Peninsula, the first seismic station was installed at Incheon in 1905 and 5 additional seismic stations were installed till 1943. There was no seismic station from 1945 to 1962, but a World Wide Standardized Seismograph was installed at Seoul in 1963. In 1990, Korean Meteorological Adminstration(KMA) had established centralized modem seismic network in real-time, consisted of 12 stations. After that time, many institutes tried to expand their own seismic networks in Korea Peninsula. Now KMA operates 35 velocity-type seismic stations and 75 accelerometers and Korea Institute of Geoscience and Mineral Resources operates 32 and 16 stations, respectively. Korea Institute of Nuclear Safety and Korea Electric Power Research Institute operate 4 and 13 stations, consisted of velocity-type and accelerometer. In and around the Korean Peninsula, 27 intraplate earthquake mechanisms since 1936 were analyzed to understand the regional stress orientation and tectonics. These earthquakes are largest ones in this century and may represent the characteristics of earthquake in this region. Focal mechanism of these earthquakes show predominant strike-slip faulting with small amount of thrust components. The average P-axis is almost horizontal ENE-WSW. In north-eastern China, strike-slip faulting is dominant and nearly horizontal average P-axis in ENE-WSW is very similar with the Korean Peninsula. On the other hand, in the eastern part of East Sea, thrust faulting is dominant and average P-axis is horizontal with ESE-WNW. This indicate that not only the subducting Pacific Plate in east but also the indenting Indian Plate controls earthquake mechanism in the far east of the Eurasian Plate. Crustal velocity model is very important to determine the hypocenters of the local earthquakes. But the crust model in and around Korean Peninsula is not clear till now, because the sufficient seismic data could not accumulated. To solve this problem, reflection and refraction seismic survey and seismic wave analysis method were simultaneously applied to two long cross-section traversing the southern Korean Peninsula since 2002. This survey should be continuously conducted.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.3
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• pp.221-229
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• 1990

The horizontal distribution of squid gill-net fishing ground in the North Pacific Ocean was examined within the main fishing season, May to October, during 1986~1989. Data of sea surface temperature were selected from Technical Reports of National Fisheries Research Development Agency of Korea, Data Records of Hokkaido University, Deep-sea Training Reports of Korea Fishing Training centre, Fishing Operation Reports of Daelim Fisheries Co., Ltd., Oyang Fisheries Co., Ltd. and Dong-won Industrial Co., Ltd.. Data of catch were also collected from Deep-sea Training Reports of Korea Fishing Training Centre and Fishing Operation Report of three fisheries companies in Korea. The fishing ground was segmented in every 1 degree of latitude from $34^{\circ}N$ to $46^{\circ}N$ and 2 degree of longitude from $144^{\circ}E$ to $162^{\circ}W.$ The distribution and centeroid of fishing ground, fished and optimum surface temperature, catch per unit effort (CPUE) in the fishing ground were computed, based on the above data. The resulted obtained can be summarized as follows: 1. Range of fishing ground can be estimated as $35^{\circ}~40^{\circ}N,$ $178^{\circ}~166^{\circ}W$ in May, $36^{\circ}~41^{\circ}N,$ $178^{\circ}E~166^{\circ}W$ in June, $38^{\circ}~44^{\circ}N,$ $170^{\circ}E~170^{\circ}W$ in July, $39^{\circ}~44^{\circ}N,$ $144^{\circ}~180^{\circ}E$ in August, $39^{\circ}~44^{\circ}N,$ $144^{\circ}~170^{\circ}E$ in September and $40^{\circ}~44^{\circ}N,$ $144^{\circ}~154^{\circ}E$ in October. 2. Fishing ground in May, June and October is similarly distributed along longitude and latitude, but the range of the former is larger than that of the latter in July, August and September. Monthly centeroids of fishing sectors is estimated as #3888 in May, #3884 in June, #4078 in July, #4154 in August, #4146 in September and #4044 in October respectively. 3. Fished temperature and optimum and temperature are estimated as $14.0~18.5^{\circ}C$ and $15.0~16.0^{\circ}C$ in May, $13.5~18.5^{\circ}C$ and $14.5~16.0^{\circ}C$ in June, $14.0~20.0^{\circ}C$ and $14.5^{\circ}C,$ $19.0^{\circ}C$ in July, $16.0~21.5^{\circ}C$ and $18.0~20.0^{\circ}C$ in August, $14.5~22.0^{\circ}C$ and $17.0~18.5^{\circ}C$ in September, $14.0~18.0^{\circ}C$ and $16.0~17.0^{\circ}C$ in October. 4. Monthly mean CPUE which corresponds to the net weight of catch(kg) divided by the sheet number of operated gillnets is calcuted as 3.2, 4.5, 4.3, 5.1, 6.4 and 5.8 kg/sheet respectively. 5. Considering the monitoring program of the squid gill-net fishery in the North Pacific Ocean during 1989~1990, set by the Korean Government, 12 sectors may be restricted out of 21 fishing sectors in May, 7 out of 24 in June, 4 out of 25 in July. They are free from restriction hereafter August.

• Journal of Intelligence and Information Systems
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• v.23 no.4
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• pp.111-126
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• 2017

Recommender systems based on association rule mining significantly contribute to seller's sales by reducing consumers' time to search for products that they want. Recommendations based on the frequency of transactions such as orders can effectively screen out the products that are statistically marketable among multiple products. A product with a high possibility of sales, however, can be omitted from the recommendation if it records insufficient number of transactions at the beginning of the sale. Products missing from the associated recommendations may lose the chance of exposure to consumers, which leads to a decline in the number of transactions. In turn, diminished transactions may create a vicious circle of lost opportunity to be recommended. Thus, initial sales are likely to remain stagnant for a certain period of time. Products that are susceptible to fashion or seasonality, such as clothing, may be greatly affected. This study was aimed at expanding association rules to include into the list of recommendations those products whose initial trading frequency of transactions is low despite the possibility of high sales. The particular purpose is to predict the strength of the direct connection of two unconnected items through the properties of the paths located between them. An association between two items revealed in transactions can be interpreted as the interaction between them, which can be expressed as a link in a social network whose nodes are items. The first step calculates the centralities of the nodes in the middle of the paths that indirectly connect the two nodes without direct connection. The next step identifies the number of the paths and the shortest among them. These extracts are used as independent variables in the regression analysis to predict future connection strength between the nodes. The strength of the connection between the two nodes of the model, which is defined by the number of nodes between the two nodes, is measured after a certain period of time. The regression analysis results confirm that the number of paths between the two products, the distance of the shortest path, and the number of neighboring items connected to the products are significantly related to their potential strength. This study used actual order transaction data collected for three months from February to April in 2016 from an online commerce company. To reduce the complexity of analytics as the scale of the network grows, the analysis was performed only on miscellaneous goods. Two consecutively purchased items were chosen from each customer's transactions to obtain a pair of antecedent and consequent, which secures a link needed for constituting a social network. The direction of the link was determined in the order in which the goods were purchased. Except for the last ten days of the data collection period, the social network of associated items was built for the extraction of independent variables. The model predicts the number of links to be connected in the next ten days from the explanatory variables. Of the 5,711 previously unconnected links, 611 were newly connected for the last ten days. Through experiments, the proposed model demonstrated excellent predictions. Of the 571 links that the proposed model predicts, 269 were confirmed to have been connected. This is 4.4 times more than the average of 61, which can be found without any prediction model. This study is expected to be useful regarding industries whose new products launch quickly with short life cycles, since their exposure time is critical. Also, it can be used to detect diseases that are rarely found in the early stages of medical treatment because of the low incidence of outbreaks. Since the complexity of the social networking analysis is sensitive to the number of nodes and links that make up the network, this study was conducted in a particular category of miscellaneous goods. Future research should consider that this condition may limit the opportunity to detect unexpected associations between products belonging to different categories of classification.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.2
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• pp.26-44
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• 2017

Regarded as Korea's traditional pond, Gungnamj Pond was surmised to be "Gungnamji" due to its geological positioning in the south of Hwajisan (花枝山) and relics of the Gwanbuk-ri (官北里) suspected of being components to the historical records of Muwang (武王)'s pond of The Chronicles of the Three States [三國史記] and Sabi Palace, respectively, yet was subjected to a restoration following a designation to national historic site. This study is focused on the distortion of authenticity identified in the course of the "Gungnamji Pond" restoration and the invention of tradition, whose summarized conclusions are as follows. 1. Once called Maraebangjuk (마래방죽), or Macheonji (馬川池) Pond, Gungnamji Pond was existent in the form of a low-level swamp of vast area encompassing 30,000 pyeong during the Japanese colonial period. Hong, Sa-jun, who played a leading role in the restoration of "Gungnamji Pond," said that even during the 1940s, the remains of the island and stone facilities suspected of being the relics of Gungnamji Pond of the Baekje period were found, and that the traces of forming a royal palace and garden were discovered on top of them. Hong, Sa-jun also expressed an opinion of establishing a parallel between "Gungnamji Pond" and "Maraebangjuk" in connection with a 'tale of Seodong [薯童說話]' in the aftermath of the detached palace of Hwajisan, which ultimately operated as a theoretical ground for the restoration of Gungnamj Pond. Assessing through Hong, Sa-jun's sketch, the form and scale of Maraebangjuk were visible, of which the form was in close proximity to that photographed during the Japanese colonial period. 2. The minimized restoration of Gungnamji Pond faced deterrence for the land redevelopment project implemented in the 1960s, and the remainder of the land size is an attestment. The fundamental problem manifest in the restoration of Gungnamji Pond numerously attempted from 1964 through 1967 was the failure of basing the restorative work in the archaeological facts yet in the perspective of the latest generations, ultimately yielding a replication of Hyangwonji Pond of Gyeongbok Palace. More specifically, the methodologies employed in setting an island and a pavilion within a pond, or bridging an island with a land evidenced as to how Gungnamji Pond was modeled after Hyangwonji Pond of Gyeongbok Palace. Furthermore, Chihyanggyo (醉香橋) Bridge referenced in the designing of the bridge was hardly conceived as a form indigenous to the Joseon Dynasty, whose motivation and idea of the misguided restoration design at the time all the more devaluated Gungnamji Pond. Such an utterly pure replication of the design widely known as an ingredient for the traditional landscape was purposive towards the aesthetic symbolism and preference retained by Gyeongbok Palace, which was intended to entitle Gungnamji Pond to a physical status of the value in par with that of Gyeongbok Palace. 3. For its detachment to the authenticity as a historical site since its origin, Gungnamji Pond represented distortions of the landscape beauty and tradition even through the restorative process. The restorative process for such a historical monument, devoid of constructive use and certain of distortion, maintains extreme intimacy with the nationalistic cultural policy promoted by the Park, Jeong-hee regime through the 1960s and 1970s. In the context of the "manipulated discussions of tradition," the Park's cultural policy transformed the citizens' recollection into an idealized form of the past, further magnifying it at best. Consequently, many of the historical sites emerged as fancy and grand as they possibly could beyond their status quo across the nation, and "Gungnamji Pond" was a victim to this monopolistic government-led cultural policy incrementally sweeping away with new buildings and structures instituted regardless of their original space, and hence, their value.

• Journal of Intelligence and Information Systems
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• v.16 no.2
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• pp.19-32
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• 2010

Volatility plays a central role in both academic and practical applications, especially in pricing financial derivative products and trading volatility strategies. This study presents a novel mechanism based on generalized autoregressive conditional heteroskedasticity (GARCH) models that is able to enhance the performance of intelligent volatility trading systems by predicting Korean stock market volatility more accurately. In particular, we embedded the concept of the volatility asymmetry documented widely in the literature into our model. The newly developed Korean stock market volatility index of KOSPI 200, VKOSPI, is used as a volatility proxy. It is the price of a linear portfolio of the KOSPI 200 index options and measures the effect of the expectations of dealers and option traders on stock market volatility for 30 calendar days. The KOSPI 200 index options market started in 1997 and has become the most actively traded market in the world. Its trading volume is more than 10 million contracts a day and records the highest of all the stock index option markets. Therefore, analyzing the VKOSPI has great importance in understanding volatility inherent in option prices and can afford some trading ideas for futures and option dealers. Use of the VKOSPI as volatility proxy avoids statistical estimation problems associated with other measures of volatility since the VKOSPI is model-free expected volatility of market participants calculated directly from the transacted option prices. This study estimates the symmetric and asymmetric GARCH models for the KOSPI 200 index from January 2003 to December 2006 by the maximum likelihood procedure. Asymmetric GARCH models include GJR-GARCH model of Glosten, Jagannathan and Runke, exponential GARCH model of Nelson and power autoregressive conditional heteroskedasticity (ARCH) of Ding, Granger and Engle. Symmetric GARCH model indicates basic GARCH (1, 1). Tomorrow's forecasted value and change direction of stock market volatility are obtained by recursive GARCH specifications from January 2007 to December 2009 and are compared with the VKOSPI. Empirical results indicate that negative unanticipated returns increase volatility more than positive return shocks of equal magnitude decrease volatility, indicating the existence of volatility asymmetry in the Korean stock market. The point value and change direction of tomorrow VKOSPI are estimated and forecasted by GARCH models. Volatility trading system is developed using the forecasted change direction of the VKOSPI, that is, if tomorrow VKOSPI is expected to rise, a long straddle or strangle position is established. A short straddle or strangle position is taken if VKOSPI is expected to fall tomorrow. Total profit is calculated as the cumulative sum of the VKOSPI percentage change. If forecasted direction is correct, the absolute value of the VKOSPI percentage changes is added to trading profit. It is subtracted from the trading profit if forecasted direction is not correct. For the in-sample period, the power ARCH model best fits in a statistical metric, Mean Squared Prediction Error (MSPE), and the exponential GARCH model shows the highest Mean Correct Prediction (MCP). The power ARCH model best fits also for the out-of-sample period and provides the highest probability for the VKOSPI change direction tomorrow. Generally, the power ARCH model shows the best fit for the VKOSPI. All the GARCH models provide trading profits for volatility trading system and the exponential GARCH model shows the best performance, annual profit of 197.56%, during the in-sample period. The GARCH models present trading profits during the out-of-sample period except for the exponential GARCH model. During the out-of-sample period, the power ARCH model shows the largest annual trading profit of 38%. The volatility clustering and asymmetry found in this research are the reflection of volatility non-linearity. This further suggests that combining the asymmetric GARCH models and artificial neural networks can significantly enhance the performance of the suggested volatility trading system, since artificial neural networks have been shown to effectively model nonlinear relationships.

• Journal of Intelligence and Information Systems
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• v.19 no.3
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• pp.93-111
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• 2013

As Internet and information technology (IT) continues to develop and evolve, the issue of big data has emerged at the foreground of scholarly and industrial attention. Big data is generally defined as data that exceed the range that can be collected, stored, managed and analyzed by existing conventional information systems and it also refers to the new technologies designed to effectively extract values from such data. With the widespread dissemination of IT systems, continual efforts have been made in various fields of industry such as R&D, manufacturing, and finance to collect and analyze immense quantities of data in order to extract meaningful information and to use this information to solve various problems. Since IT has converged with various industries in many aspects, digital data are now being generated at a remarkably accelerating rate while developments in state-of-the-art technology have led to continual enhancements in system performance. The types of big data that are currently receiving the most attention include information available within companies, such as information on consumer characteristics, information on purchase records, logistics information and log information indicating the usage of products and services by consumers, as well as information accumulated outside companies, such as information on the web search traffic of online users, social network information, and patent information. Among these various types of big data, web searches performed by online users constitute one of the most effective and important sources of information for marketing purposes because consumers search for information on the internet in order to make efficient and rational choices. Recently, Google has provided public access to its information on the web search traffic of online users through a service named Google Trends. Research that uses this web search traffic information to analyze the information search behavior of online users is now receiving much attention in academia and in fields of industry. Studies using web search traffic information can be broadly classified into two fields. The first field consists of empirical demonstrations that show how web search information can be used to forecast social phenomena, the purchasing power of consumers, the outcomes of political elections, etc. The other field focuses on using web search traffic information to observe consumer behavior, identifying the attributes of a product that consumers regard as important or tracking changes on consumers' expectations, for example, but relatively less research has been completed in this field. In particular, to the extent of our knowledge, hardly any studies related to brands have yet attempted to use web search traffic information to analyze the factors that influence consumers' purchasing activities. This study aims to demonstrate that consumers' web search traffic information can be used to derive the relations among brands and the relations between an individual brand and product attributes. When consumers input their search words on the web, they may use a single keyword for the search, but they also often input multiple keywords to seek related information (this is referred to as simultaneous searching). A consumer performs a simultaneous search either to simultaneously compare two product brands to obtain information on their similarities and differences, or to acquire more in-depth information about a specific attribute in a specific brand. Web search traffic information shows that the quantity of simultaneous searches using certain keywords increases when the relation is closer in the consumer's mind and it will be possible to derive the relations between each of the keywords by collecting this relational data and subjecting it to network analysis. Accordingly, this study proposes a method of analyzing how brands are positioned by consumers and what relationships exist between product attributes and an individual brand, using simultaneous search traffic information. It also presents case studies demonstrating the actual application of this method, with a focus on tablets, belonging to innovative product groups.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.4-23
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• 2018

Seo Byeong-o (徐丙五, 1862-1936) played a central role in the formation of the Daegu artistic community-which advocated artistic styles combining poetry, calligraphy and painting-during the Japanese colonial period, when the introduction of the Western concept of 'art' led to the adoption of Japanese and Western styles of painting in Korea. Seo first entered the world of calligraphy and painting after meeting Lee Ha-eung (李昰應, 1820-1898) in 1879, but his career as a scholar-artist only began in earnest after Korea was annexed by Japan in 1910. Seo's oeuvre can be broadly divided into three periods. In his initial period of learning, from 1879 to 1897, his artistic activity was largely confined to copying works from Chinese painting albums and painting works in the "Four Gentlemen" genre, influenced by the work of Lee Ha-eung, in his spare time. This may have been because Seo's principal aim at this time was to further his career as a government official. His subsequent period of development, which lasted from 1898 until 1920, saw him play a leading social role in such areas as the patriotic enlightenment movement until 1910, after which he reoriented his life to become a scholar-artist. During this period, Seo explored new styles based on the orchid paintings of Min Yeong-ik (閔泳翊, 1860-1914), whom he met during his second trip to Shanghai, and on the bamboo paintings of Chinese artist Pu Hua (蒲華, 1830-1911). At the same time, he painted in various genres including landscapes, flowers, and gimyeong jeolji (器皿折枝; still life with vessels and flowers). In his final mature period, from 1921 to 1936, Seo divided his time between Daegu and Seoul, becoming a highly active calligrapher and painter in Korea's modern art community. By this time his unique personal style, characterized by broad brush strokes and the use of abundant ink in orchid and bamboo paintings, was fully formed. Records on, and extant works from, Seo's early period are particularly rare, thus confining knowledge of his artistic activities and painting style largely to the realm of speculation. In this respect, eleven recently revealed nanjukseok (蘭竹石圖; orchid, bamboo and rock) paintings, produced by Seo in 1889, provide important clues about the origins and standards of his early-period painting style. This study uses a comparative analysis to confirm that Seo's orchid paintings show the influence of the early gunran (群蘭圖; orchid) and seongnan (石蘭圖; rock and orchid) paintings produced by Lee Ha-eung before his arrest by Qing troops in July 1882. Seo's bamboo paintings appear to show both that he adopted the style of Zheng Xie (鄭燮, 1693-1765) of the Yangzhou School (揚州畵派), a style widely known in Seoul from the late eighteenth century onward, and of Heo Ryeon (許鍊, 1809-1892), a student of Joseon artist Kim Jeong-hui (金正喜,1786-1856), and that he attempted to apply a modified version of Lee Ha-eung's seongnan painting technique. It was not possible to find other works by Seo evincing a direct relationship with the curious rocks depicted in his 1889 paintings, but I contend that they show the influence of both the late-nineteenth-century-Qing rock painter Zhou Tang (周棠, 1806-1876) and the curious rock paintings of the middle-class Joseon artist Jeong Hak-gyo (丁學敎, 1832-1914). In conclusion, this study asserts that, for his 1889 nanjukseok paintings, Seo Byeong-o adopted the styles of contemporary painters such as Heo Ryeon and Jeong Hak-gyo, whom he met during his early period at the Unhyeongung through his connection with its occupant, Lee Ha-eung, and those of artists such as Zheng Xie and Zhou Tang, whose works he was able to directly observe in Korea.