• Journal of Information Management
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• v.43 no.2
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• pp.151-168
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• 2012

A viral marketing has been an effective marketing tool in various fields. In this study, we applied a viral marketing strategy for managing the Internet community website of scientists and engineers, KOSEN(www.kosen21.org). We developed a function that enables members to send promotional e-mails to their acquaintances, and we also designed a reward system for the members who participated in KOSEN viral marketing. With these strategies, KOSEN members reacted positively on the rewards (i.e., mileage points, gift card) and also the loyalty members took part in the viral marketing program more actively than other members. Furthermore, an attractive event was very effective for the prompt reaction of the viral marketing. Managing loyalty members is necessary for the continuous effects. The viral marketing strategies and analysis results of this research could be used for the management of an Internet service.

• International Journal of Computer Science & Network Security
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• v.24 no.9
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• pp.169-185
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• 2024

Due to levitate and rapid growth of E-Commerce, most of the organizations are moving towards cashless transaction Unfortunately, the cashless transactions are not only used by legitimate users but also it is used by illegitimate users and which results in trouncing of billions of dollars each year worldwide. Fraud prevention and Fraud Detection are two methods used by the financial institutions to protect against these frauds. Fraud prevention systems (FPSs) are not sufficient enough to provide fully security to the E-Commerce systems. However, with the combined effect of Fraud Detection Systems (FDS) and FPS might protect the frauds. However, there still exist so many issues and challenges that degrade the performances of FDSs, such as overlapping of data, noisy data, misclassification of data, etc. This paper presents a comprehensive survey on financial fraud detection system using such data mining techniques. Over seventy research papers have been reviewed, mainly within the period 2002-2015, were analyzed in this study. The data mining approaches employed in this research includes Neural Network, Logistic Regression, Bayesian Belief Network, Support Vector Machine (SVM), Self Organizing Map(SOM), K-Nearest Neighbor(K-NN), Random Forest and Genetic Algorithm. The algorithms that have achieved high success rate in detecting credit card fraud are Logistic Regression (99.2%), SVM (99.6%) and Random Forests (99.6%). But, the most suitable approach is SOM because it has achieved perfect accuracy of 100%. But the algorithms implemented for financial statement fraud have shown a large difference in accuracy from CDA at 71.4% to a probabilistic neural network with 98.1%. In this paper, we have identified the research gap and specified the performance achieved by different algorithms based on parameters like, accuracy, sensitivity and specificity. Some of the key issues and challenges associated with the FDS have also been identified.

• Microbiology and Biotechnology Letters
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• v.34 no.4
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• pp.342-351
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• 2006

The aim of this study was to survey susceptibilities of Escherichia coli and Klebsiella pneumoniae isolates against cefotaxime and to determine the prevalences of CTX-M type extended-spectrum $\beta$-lactamases (ESBLs) producing E. coli and K. pneumoniae in Korea. During the period of February to July, 2005, 153 E. coli and 52 K. neumoniae isolates were collected from 2 hospitals in Busan. Antimicrobial susceptibilities to cefotaxime were tested by the disk diffusion method. ESBL production of E. coli and K. pneumoniae was determined by the double disk synergy test. MICs of $\beta$-lactam antibiotics were determined by the agar dilution method. Blac$_{CTX-M}$ genes of the organism were detected by PCR. Among 153 isolates of E. coli and 52 isolates of K. neumoniae, 27 (17.6%) and 25 (48.0%) were intermediate or resistant to cefotaxime, respectively. Twenty-three (15.0%) isolates out of 153 E. coli and 13 (25.0%) out of 52 K. neumoniae isolates showed positive results for ESBL by the double disk synergy test. Twenty isolates out of 23 ESBL producing E. coli and 12 out of 13 ESBL producing K. neumoniae isolates harbored biacTx-M gene,11 of ESBL producing E. coli and 12 of ESBL producing K. neuinoniae isolates harbored bla$_{CTX-M}$ gene, 11 of the ESBL producing E. coli and 2 of ESBL producing K. neumoniae isolates harbored bla$_{TEM}$ gene, and 1 of the ESBL producing E. coli and 12 of ESBL producing K. neumoniae isolates harbored bla$_{SHV}$ gene. E. coli and K. neumoniae isolates producing CTX-M-type ESBLs were not uncommon in Korea. It is thought that continuous survey are necessary for inspecting the spread and novel variants of CTX-M-type ESBL genes. Further me]'e investigation and research on ESBL producing strains are needed in order to prevent the spread of resistant bacteria.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.12
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• pp.2202-2211
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• 2006

EXT3NS is a special-purpose file system for large scale multimedia streaming servers. It is built on top of streaming acceleration hardware device called Network-Storage card. The EXT3NS file system significantly improves streaming performance by eliminating memory-to-memory copy operations, i.e. sending video/audio from disk directly to network interface with no main memory buffering. In this paper, we design and implement a buffer cache mechanism, called PMEMCACHE, for EXT3NS file system. We also propose a buffer cache replacement method called ONS for the buffer cache mechanism. The ONS algorithm outperforms other existing buffer replacement algorithms in distributed multimedia streaming environment. In EXT3NS with PMEMCACHE, operation is 33MB/sec and random read operation is 2.4MB/sec. Also, the buffer replacement ONS algorithm shows better performance by 600KB/sec than other buffer cache replacement policies. As a result PMEMCACHE and an ONS can greatly improve the performance of multimedia steaming server which should supportmultiple client requests at the same time.

• Informatization Policy
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• v.22 no.4
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• pp.22-44
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• 2015

With the growing interest being reflected in the FinTech industry, much attention has been paid to mobile easy payment services as well. In the era of mobile commerce, the core advantage of using mobile easy payment services(simplifying complex payment procedures and thus facilitating user convenience and reducing the chance of giving up payment) are being more emphasized. Mobile easy payment service market not only includes mobile easy payment service providers but also users, non-users, affiliates, banks, and credit card companies as main stakeholders. Exploring those stakeholders is thus important to thoroughly understand such market. However, extant literature on mobile easy payment services mostly focuses on examining adoption intention of users or non-users. This study, an exploratory research based on interviews, thus aims to extract driving as well as inhibiting factors of mobile easy payment service use from six different perspectives (i.e., social platform, bank, credit card company, affiliate, user, and non-user) and analyze a sequence of cause and effect for each factor. For this, the causal loop diagram was developed to deduce key issues and propose an alternative. Theoretical and practical implications of this study will also be discussed.

• Physical Therapy Korea
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• v.3 no.3
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• pp.44-58
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• 1996

The purpose of this study was to compare and evaluate various hand functions in the most common position (chair sitting, standing, floor sitting) used by cerebral palsied children with spastic diplegia. The results, analysed statistically, could be useful in suggesting treatment strategy for the improvement of hand function in such patient. For this study, 27 children mild or moderate spastic diplegia were chosen. They were patients of the Rehabilitation Hospital, Yonsei University Medical Center. Both dominant and nondominant hands were tested by the Box and Block Test. Bilateral hand function was tested by bead striding and card sorting activities. Collected data was analysed using univariate correlation analysis and MANOVA. Results were as follows: 1) In chair sitting there was a significant positive correlation between dominant hand scores in the Bloc and Box Test and chronological age, gestation period, and time of treatment initiation. In bilateral hand function, card sorting scores correlated positively with time of treatment initiation. 2) In standing, there was a significantly positive correlation between dominant hand scores in the Block and Box Test and time of treatment initiation. 3) In floor sitting, there was a significantly positive correlation between the dominance hand scores in the Block and Box Test and the tine of treatment initiation. Bead stringing, a bilateral hand activity, correlated positively with gestation period and birth weight but negatively with the postnatal incubation period. 4) That score of children who walked showed no significant difference in any of the three postures. 5) Highest test scores in children who could nat walk were in the Box and Block Test for nondominant hand in bead stringing for bilateral hand function. There scores occurred with the children in thee chair sitting posture. The results showed that, in order to improve hand function in children with spastic diplegia, it is necessary to maintain a well supported upright trunk posture with variations allowed for relevance to the chosen position of thee improvements hand activity being performed.

• Journal of Distribution Science
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• v.13 no.1
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• pp.83-91
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• 2015

Purpose - Despite the structural irrationality of multi-level transportation and the oil price rise, the domestic freight transportation market continues to grow, mirroring the rise in e-commerce and resultant increase in courier services and freight volumes. Several studies on courier services have been conducted. However, few studies or statistics have been published regarding regular freight services although they have played a role in the freight service market. The present study identifies the characteristics of regular freight service users to seek competitiveness enhancement measures specific to regular freight services. Research design, data, and methodology - IPA is a comparative analysis of the relative importance of and satisfaction with each attribute simultaneously. This study used IPA because it facilitates the process of analyzing importance and performance, deriving implications and a visual understanding of results. To enhance the competitiveness of regular freight services, this study surveyed its current users regarding the importance of the regular freight service factors. A total of 200 copies of a questionnaire were circulated and 190 copies were returned. In addition to demographics, respondents answered questions about the importance of and satisfaction with services on a 5-point Likert scale. Excluding 3 inappropriate copies, 187 out of 190 copies were analyzed. PASW Statistics 18 was used for statistical analysis. A total of 20 question items were selected for the service factors presented in the questionnaire based on the 1st pilot survey and previous studies. Results - According to the IPA performed to compare the importance of and satisfaction with service factors, both importance and satisfaction are high in the 1st quadrant, which involves the economic advantage of using regular freight services, quick arrival at destinations, weight freight handling, and less time constraints on freight receipt/dispatch. This area requires continuous management. Satisfaction is higher than importance in the 2nd quadrant, which involves the adequacy of freight, cost savings over ordinary courier services, notification on freight arrival, and freight tracking information. This area requires intensive investment and management. Satisfaction is lower than importance in the 3rd quadrant, involving the credit card payment system, courier delivery service, distance to freight handling sites, easy access to freight handling sites, and prompt problem solving. This area requires further intensive management. Both importance and satisfaction are low in the 4th quadrant, involving the availability of collection service, storage space at freight handling sites, kindness of collection/delivery staff, kindness of outlet staff, and easy delivery checks. This area is a set of variables should be excluded from priority control targets. Conclusions - Based on the IPA, service factors that need priority controls because of high importance and low satisfaction include the credit card payment system, delivery service, distance to freight handling sites, easy access to freight handling sites, and prompt problem solving. The findings need to be applied to future marketing strategies for regular freight services and for developing competitiveness enhancement programs.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.3
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• pp.1-11
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• 2023

COVID-19 has caused the dramatic reduction of public transportation demand in Busan Metropolitan City, that is, daily public transportation trips in 2020 dropped by approximately 920,000 trips from 2019 based on the public transportation card data. This study investigated the underlying factors affecting the public transportation demand discrepancy between before and after COVID-19 at the primary administration unit(i.e., Eup, Myeon, Dong) level with Ordered Logistic Regression model. Finding of this study is as follows. The primary administration units characterized with high ratio of welfare recipients, industrial area, and day boarders were heavily dependent on public transit, indicating little change in public transportation demand. On the other hands, the primary administration units which have high ratio of urban rail transit uses experienced significant reduction of public transportation demand. In conclusion, transportation policies taken under emergent situation such as COVID-19 need to take into account the region-based characteristics rather than unilateral ones.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.489-492
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• 2005

We report new polymer stabilized ferroelectric liquid crystal (PSFLC) cells with mechanical stability which is achievable by introducing photospacers in the cells. It was found that the mechanical st ability of the PSFLC cell was effected by introduction of photo spacers. We analyzed the dependence of mechanical stability and memory property on the density of photospacers in the PSFLC cell. The stability and memory properties of PSFLC Cells depending on photospacer density are discussed. 1. Introduction Recently, flexible displays have attracted much attention because they have remarkable advantages: thinner, lighter, non-breakable and conformable features. Flexible displays have various potential applications such as e-book and e-paper displays utilizing the distinct features. E-book and E-paper displays demand very low power consumption, so that bistable memory liquid crystal modes are required in case of flexible plastic LCDs for those application. Three kinds of memory LC modes have been developed; bistable nematic, bistable cholesteric and bistable FLC. Among them SSFLC as one of bistable FLC has big advantages such as low driving voltage, wide view angle and fast response time, SSFLC cells are, however, very weak against mechanical shock. Polymer stabilized FLC (PSFLC) has been developed to overcome the poor mechanical stability of SSFLC. PSFLC was known to have network structure that FLCs are oriented with smectic layer ordering in polymer network. The polymer network stabilizes the FLC orientation, which leads to improvement of mechanical stability of PSFLCD. A lot of studies have been done for the application of PSFLC to flexible $LCDs.^{[1{\sim}12]}$ However, it should be noted that PSFLC does not have sufficient mechanical stability for the particular applications such as smart card LCD, where LCD is highly bendable.Bead spacer was mainly used to maintain cell gap of conventional PSFLCDs. But the spacer density of it is not locally uniform in the cell, so that it is generally difficult that the PSFLCDs with bead spacers show sufficient mechanical stability. In order to more improve the mechanical stability of PSFLCDs, we introduced photospacers into PSFLCDs. In this paper, we describe the improvement of mechanical stability by introducing photospacers into PSFLCDs.

• Archives of design research
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• v.17 no.3
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• pp.199-208
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• 2004

From the aspect that design should respond to the necessity of various cultural bases, design is important to be grafted to Korean traditional culture. This circumstance leads this study to clarify the plan of multimedia contents development of 'paintings and original forms of shaman spirit' in Korean shamanism as one of realistic re-illumination works for Korean cultural original forms. The main study results are conduded as followings through literature reviews, internet searches and case studies. First, 'the planning process' necessary for the development of scenarios, characters and multimedia contents are suggested based on the establishment of hierarchy structure among shaman spirits which are classified into necromancer, human being, nature and life after death. Second, relating to execution of process above, it is suggested that 'the strategic. plan by business items and its genres' such as blessing fancy goods, characters for mobile or game, scenarios for game or animation, online digital exorcisms, e-cards, e-talismans and so on. Finally, as future industrialization concerns, 'the industrial development plan' is suggested which can be extended to scenario-based original businesses such as game scenarios for online or mobile and heroism fictions. The study results highlight the fact that multimedia design approach are considered for expanding the target and scope of creative material for Korean cultural original forms. Future researches, based on the results of the study, are expected to be expanded to the various designerly-thinking approaches into 'Shaman' themes and rather to be re-illuminated to the development of Korean cultural original forms as a nation's strategic standpoint.