• Information Systems Review
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• v.11 no.1
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• pp.161-179
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• 2009

Nowadays an increasing number of Internet users are running individual websites as Blog or Cyworld. As this type of personal media has a great influence on communication among people, business comes to care about Network Effect, Network Software, and Social Network. For instance, Cyworld created the web service called 'Minihompy' for individual web-logs, and acquired 2.4milion users in 2007. Although many people assumed that the popularity of Minihompy, or Blog would be a passing fad, Cyworld has improved its service, and expanded its Network with various contents. This kind of expansion reflects survival efforts from infinite competitions among ISPs (Internet Service Provider) with focus on enhancing usability to users. However, Cyworld's Network Effect is gradually diminished in these days. Both of low production cost of service vendors and the low searching/conversing costs of users combine to make ISPs hard to keep their market share sustainable. To overcome this lackluster trend, Cyworld has adopted new strategies and try to lock their users in their service. Various efforts to improve the continuance and expansion of Network effect remain unclear and uncertain. If we understand beforehand how a service would improve Network effect, and which service could bring more effect, ISPs can get substantial help in launching their new business strategy. Regardless many diverse ideas to increase their user's duration online ISPs cannot guarantee 'how the new service strategies will end up in profitability. Therefore, this research studies about Network effect of Cyworld's 'Minihompy' using System-Dynamics method which could analyze dynamic relation between users and ISPs. Furthermore, the research aims to predict changes of Network Effect based on the strategy of new service. 'Page View' and 'Duration Time' can be enhanced for the short tenn because they enhance the service functionality. However, these services cannot increase the Network in the long-run. Limitations of this research include that we predict the future merely based on the limited data. We also limit the independent variables over Network Effect only to the following two issues: Increasing the number of users and increasing the Service Functionality. Despite of some limitations, this study perhaps gives some insights to the policy makers or others facing the stiff competition in the network business.

• Information Systems Review
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• v.16 no.3
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• pp.49-68
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• 2014

These days, consumers have increasingly preferred to digital real-time streamlining and downloading to listen to music because this is convenient and affordable for the consumers. Accordingly, sales of music in compact disk formats have steadily declined. In this regards, online digital music has become a new communication channel to listen musics, where digital files can be delivered over various online networks to people's computing devices. The majority of online digital music distributors has Music Recommender Systems for sales of digital music on their websites. Music Recommender Systems are parts of information filtering systems that provide the ratings or preferences that users give to music. Korean online digital music distributors have Music Recommender Systems. But those online music distributors didn't provide any rules or clear procedures that recommend music. Therefore, we raise important questions as follows: "Is Music Recommender Systems Fair?", "What is the impact of Music Recommender Systems on online music rankings and sales?" While previous studies have focused on usefulness of Music Recommender Systems, this study investigates not only fairness of Current Music Recommender Systems but also Relationship between Music Recommender Systems and online Music Charts. This study examines these issues based on Bandwagon effect, ranking effect, Slot effect theories. For our empirical analysis, we selected the most famous five online digital music distributors in terms of market shares. We found that all recommended music is exposed to the top of 'daily music charts' in online digital music distributors' websites. We collected music ranking data and recommended music data from 'daily music chart' during a one month. The result shows that online music recommender systems are not fair, since they mainly recommend particular music that supported by a specific music production company. In addition, the recommended music are always exposed to the top of music ranking charts. We also find that recommended music usually appear at the top 20 ranking charts within one or two days. Also, the most music in the top 50 or 100 ranks are the recommended music. Moreover, recommended music usually remain the ranking charts more than one month while non-recommended music often disappear at the ranking charts within two week. Our study provides an important implication to online music industry. Because music recommender systems and music ranking charts are closely related, music distributors may improperly use their recommender systems to boost the sales of music that related to their own companies. Therefore, online digital music distributor must clearly announce the rules and procedures about music recommender systems for the better music industry.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3395-3402
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• 2015

Background: Preoperative 5-fluorouracil (5-FU)-based chemoradiotherapy is a standard treatment for locally advanced colorectal cancer (CRC). However, CRC cells often develop chemoradiation resistance (CRR). Recent studies have shown that long non-coding RNA (lncRNA) plays critical roles in a myriad of biological processes and human diseases, as well as chemotherapy resistance. Since the roles of lncRNAs in 5-FU-based CRR in human CRC cells remain unknown, they were investigated in this study. Materials and Methods: A 5-FU-based concurrent CRR cell model was established using human CRC cell line HCT116. Microarray expression profiling of lncRNAs and mRNAs was undertaken in parental HCT116 and 5-FU-based CRR cell lines. Results: In total, 2,662 differentially expressed lncRNAs and 2,398 mRNAs were identified in 5-FU-based CRR HCT116 cells when compared with those in parental HCT116. Moreover, 6 lncRNAs and 6 mRNAs found to be differentially expressed were validated by quantitative real time PCR (qRT-PCR). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis for the differentially expressed mRNAs indicated involvement of many, such as Jak-STAT, PI3K-Akt and NF-kappa B signaling pathways. To better understand the molecular basis of 5-FU-based CRR in CRC cells, correlated expression networks were constructed based on 8 intergenic lncRNAs and their nearby coding genes. Conclusions: Changes in lncRNA expression are involved in 5-FU-based CRR in CRC cells. These findings may provide novel insight for the prognosis and prediction of response to therapy in CRC patients.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.3075-3078
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• 2013

Background: KLK3 gene products, like human prostate-specific antigen (PSA), are important biomarkers in the clinical diagnosis of prostate cancer (PCa). G protein-coupled receptor RFX6, C2orf43 and FOXP4 signaling plays important roles in the development of PCa. However, associations of these genes with PCa in northern Chinese men remain to be detailed. This study aimed to investigate their impact on occurrence and level of malignancy. Methods: All subjects were from Beijing and Tianjin, including 266 cases with prostate cancer and 288 normal individuals as controls. We evaluated associations between clinical covariates (age at diagnosis, prostate specific antigen, Gleason score, tumor stage and aggressive) and 6 candidate PCa risk loci, genotyped by PCR- high resolution melting curve and sequencing methods. Results: Case-control analysis of allelic frequency of PCa associated with PCa showed that one of the 6 candidate risk loci, rs339331 in the RFX6 gene, was associated with reduced risk of prostate cancer (odds ratio (OR) = 0.73, 95% confidence interval (CI) =0.57-0.94, P = 0.013) in northern Chinese men. In addition, subjects with CX (CC+TC) genotypes had a decreased risk for prostrate cancer compared to those carrying the TT homozygote (OR =0.64, 95% CI = 0.45- 0.90, P = 0.008). The TT genotype of 13q22 (rs9600079, T) was associated with tumor stage (P=0.044, OR=2.34, 95% CI=0.94-5.87). Other SNPs were not significantly associated with clinical covariates in prostate cancer (P > 0.05). Conclusions. rs339331 in the RFX6 gene may be associated with prostate cancer as a susceptibility locus in northern Chinese men.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.195-202
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• 2010

Purpose : Despite recent advances in pulmonary hypertension management and surgery, appropriate guidelines remain to be developed for operability in congenital heart disease with pulmonary artery hypertension (PAH). Our aim was to evaluate clinical outcomes of patients with severe PAH who underwent surgical closure of left-to-right shunt lesions (LRSL) on the basis of pulmonary reactivity. Methods : We retrospectively reviewed 21 patients who underwent surgical closure of LRSL with severe PAH (${\geq}8$ Wood unit) from January 1995 to April 2009. The median age at operation was 26 years. Atrial septal defect, ventricular septal defect (VSD), VSD and patent ductus arteriosus (PDA), and PDA was present in 11, 4, 4, and 2 patients, respectively. Results : Operability was based on vasoreactivity of PAH. Of the 21 patients, 5 showed response to pulmonary vasodilator therapy and 8 showed vasoreactivity after balloon occlusion of defects. The remaining 8 patients were considered operable because of significant left-to-right shunt (Qp/Qs ${\geq}1.5$). Five patients underwent total closure of defects and 16 were left with small residual shunts. The median follow-up duration was 32 months. There was no significant postoperative mortality or morbidity. Systolic pulmonary artery pressure (PAP) decreased in all but 2 patients. All patients except 1 showed improvement of New York Heart Association functional class. Conclusion : Closure of LRSL in patients with severe PAH on the basis of pulmonary vasoreactivity seems reasonable. PAP and clinical symptoms improved in most patients. Further research is needed for the evaluation of long-term results.

• Clinical and Experimental Pediatrics
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• v.51 no.8
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• pp.804-811
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• 2008

Purpose : Childhood obesity is a problem that places a child at great risk for becoming an obese adult. To prevent obesity, it is important to focus on early life risk factors that may contribute to childhood obesity. The aim of this study is to find obesity-causing infantile risk factors in preschool children. Methods : A total of 223 children aged 3 to 5 years old from Busan were the subjects of this study. We calculated their body mass index (BMI) and classified them into two groups (normal weight and overweight/obese children). Information regarding parental weight and height, mother's educational level and employment status, birth weight, feeding patterns, start time of weaning, duration of night feeding, and fosterer was obtained by using questionnaires. Results : There were 68 (30.5%) overweight/obese children and 155 (69.5%) normal weight children. Overweight/obese children were significantly associated with formula milk feeding, rapid weight gain during the first 6 months, and maternal obesity (P<0.05). There were no statistical differences in paternal obesity, mothers educational level and employment status, birth weight, start time of weaning, duration of night feeding, and fosterer between the normal and overweight/obese children. Conclusion : Although healthy diet and regular exercise will remain the cornerstones of weight management in obese children, our data supports the view that education about maintaining a normal weight could be introduced much earlier in families with high-risk children.

• Journal of Wetlands Research
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• v.6 no.3
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• pp.55-70
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• 2004

The wetland ecosystem is a complex products of various erosion force, accumulation as water flows, hydrogeomorphic units, seasonal changes, the amount of rainfalls, and other essential element. There is no single, correct, ecologically sound definition for wetlands because of the diversity of wetlands and the demarcation between dry and wet environments occurs along a continuum, but wetland plays various ecosystem functions. Despite comprehensive integration through classification and impact factors there is still lacking in systematic management of wetlands. Classification system developed by the USFWS(1979) is hierarchical progresses from systems and subsystems at general levels to classes, subclasses, dominance types, and habitat modifiers. Systems and subsystems are delineated according to major physical attributes such as tidal flushing, ocean-derived salts, and the energy of flowing water or waves. Classes and subclasses describe the type of substrate and habitat or the physiognomy of the vegetation or faunal assemblage. Wetland classes are divided into physical types and biotic types. For the wise management of wetlands in Korea, this study was carried out to examine methodology of USFWS classification system and discuss its application for Korean wetland hydrogeomorphic units already known. Seven wetland types were chosen as study sites in Korea divided into some different types based on USFWS system. Three wetland types belonging to palustrine system showed no difference between Wangdungjae wetland and Mujechi wetland, but Youngnup of Mt. Daeam was different from the former two types at the level of dominant types. This fact means that setting of classification system for management of wetland is needed. Although we may never know much about the wetland resources that have been lost, there are opportunities to conserve the riches that remain. Extensive inventory of all wetland types and documentation of their ecosystem functions are vital. Unique and vulnerable examples in particular need to be identified and protected. Furthermore, a framework with which to demonstrate wetland characteristics and relationships is needed that is sufficiently detailed to achieve the identification of the integrity and salient features of an enormous range of wetland types.

• Korean Journal of Heritage: History & Science
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• v.53 no.1
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• pp.4-23
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• 2020

This study examines the universal meaning of the roof-end tile, our cultural property, and especially focuses on an ontological interpretation of the "Smile of Silla" roof-end tile. In addition, the problem of good and evil read here is considered in connection with the universal problem of philosophy. The issue of good and evil is a theme in philosophy, theology, religion, and culture that will endure throughout human history in both the East and the West. Augustine and Schelling inquired deeply into the source of evil and obtained an answer to this question based on their methods, but their answer is not universal or absolute, or an answer that applies to everyone. This is because the issue of good and evil possesses both a direct relationship with every human being and a characteristic that will remain unresolved. That is to say, the metaphysical question regarding the source of evil will always be one that is open. Nietzsche, however, repudiated the morals handed down through Socrates and Christianity, and urged that we reside "beyond good and evil." This brief review argues that good and evil exists in the form of a being in itself, whether it is within our grasp or not, and reveals that good and evil is more "this-worldly" than it is "other-worldly". The roof-end tiles with facial markings passed on to us also presuppose that evil is in full force in this world and exerts its influence. This review taps into several folk methods for coping with the existence of an invincible evil that surpasses human capability and contemplates the extraordinary and creative ideas of the Silla people through their "Smile of Silla" roof-end tiles with facial markings that were used to counter evil.

• Journal of the Korean association of regional geographers
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• v.5 no.1
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• pp.25-75
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• 1999

This study concern with the pattern of Pusan Station Shopping District within Pusan City, Korea, one of the third ranked centers within Pusan-the first ranked is CBD, the second is subCBD, the third are Spa Shopping district, Tongnae shopping district, Jobang-Ap shopping district and Yangjeong shopping district. This paper serves as a part of series studies which attempt to clarify the internal structure of Pusan as a whole. Part(I) of this study deals with the pattern of functions including information & culture, business, recreation and retailing. The results are as follows. 1. Pusan Station is one of higher ranked class of central places within Pusan City. But the ratio of dwelling houses is the highest in Pusan Station among the 9 higher ranked central places within Pusan. It means that the residential areas still remain along the maze type of narrower streets inner part of the blocks, especially western belt of this shopping district. 2. Business functions are one of the important criteria which classified the central places within the city and Pusan Station is the first ranked shopping districts in terms of these criteria among the 9 higher ranked central places including CBD within Pusan City. It suggests that Pusan Station is the miniature of the CBD, SubCBD is not the miniature of CBD in the view point of business function. It also means that Pusan Station Shopping District has been developed as a special shopping district or as a special central place. It has not been evolved as a center of the hierarchy of central places within the city by the natural or organic growth. 3. Pusan Station as 'the third space or drinking place' and it's characteristics as a amusement center presents at so called the 'Texas Town'-free tax area- whose customers are mainly U. S. soldiers and foreign sailors. But from the 1990s, this 'Town' changed to 'Russian Town', You can easy to meet many Russians and Russian lettered signboards-not English- along the street. 4. Convenient stores distribute mainly at back streets or along the narrower streets. It means that this kinds of stores have a residential oriented character. And a certain convenient stores locate with almost same distances. It suggests that it's hinterland is limited in nearer neighborhoods.

• Journal of the Korean Geographical Society
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• v.31 no.3
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• pp.489-507
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• 1996

The purpose of this study is to examine the increasing number of unregistered manufacturing plants and related problems, and to recommend alternative solutions to the problems. Data are obtained from a field survey of randomly selected small scale manufacturing plants in Seoul and its suburban cities. A total number or respondents are 533, and 416 of them are unregistered plants. The Capital Regional Planning has had a goal during last three decades to lead a balanced regional economic development by restriction manufacturing plants in the Capital Region and by encouraging them in other regions in the nation. It was 1984 when a comprehensive planning was established to achieve this goal. Sets of various regulations, by-laws and codes have been implemented to regulate manu-facturing activities in the Capital Region to achieve the goal. The region is divided into three sub-regions, and a different degree of regulations is applied to each sub-region. Only a certain types of industries are allowed in a particular sub-region. For instance, a plant manufacturing high-technology products could be allowed in the most urbanized sub-region. All manu-facturing plant in the Capital Region which has ares size of larger than 200"\;"$m^2$ is compulsory to register to the local government office. In practice, however, it is not common or sometimes almost impossible to get approval for many applicant manufacturers because of strict regulations. There have been increasing number of plants in the Capital Region during last several decades, despite the strict regulations. Many of those newly established plants are without formal registration at the local administration office. howerver. These are so called 'unregisterd' plants. Surveyed data and many government official data show that many of unregistered plants have been established in recent years. which indicate that current regulations are no longer effective. The number of unregistered plants are increasing tin the Capital Region because of many locational advantages in the region for plants, particularly those in small scale. Unregistered plants are the source of many problems, such as local water pollution or noise pollution in residential areas. There are also many administration problems, bed\cause they are not registered. The central government has attempted to cure the problems of unregistered plants. For example, the government allowed a unregistered plant to remain at present site for three ydars, if it met certain conditions in three years. However, this program was unsuccessful because many of those plants were not able to meet the concitions. Three times the government renewed the term for those which did not meet conditions since 1989, but it was afraid to be without success. There are many evidences that current policies to control manufacturing plants are not effective. The Capital Region must face mounting problems if ploicies are not reformed soon. This study suggests that the policy of the Capital Regional Planning has to be reoriented to provide more favorable policies for manufacturing plants in the Capital Region than current regulations which is aimed to restrict manufacturing activities. It is time to improve many existing problems in the region through reforms and of current regulations to foster unregistered plants. This study also proposes many smaller-area sub-divisions instead of current three large area sub-regions which is too broad to apply single kind of regulation, or codes. Flexible regulations and codes can be applied to such a small-area sub-divivisions based on location and industrial characteristics of the individual sub-divisions. It is necessary to provide decent industrial environment in the Capital Region, which is best equipped to provide many favorable industrial locational factors in the nation, thus this nation can be further prepared to compete in an inter-national market at an era of globalization in manufacturing.