• Journal of the Korean Society for information Management
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• v.40 no.1
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• pp.1-21
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• 2023

This study specifically reviewed the performance of the ranking schemes as an efficient feature selection method for text classification. Until now, feature ranking schemes are mostly based on document frequency, and relatively few cases have used the term frequency. Therefore, the performance of single ranking metrics using term frequency and document frequency individually was examined as a feature selection method for text classification, and then the performance of combination ranking schemes using both was reviewed. Specifically, a classification experiment was conducted in an environment using two data sets (Reuters-21578, 20NG) and five classifiers (SVM, NB, ROC, TRA, RNN), and to secure the reliability of the results, 5-Fold cross-validation and t-test were applied. As a result, as a single ranking scheme, the document frequency-based single ranking metric (chi) showed good performance overall. In addition, it was found that there was no significant difference between the highest-performance single ranking and the combination ranking schemes. Therefore, in an environment where sufficient learning documents can be secured in text classification, it is more efficient to use a single ranking metric (chi) based on document frequency as a feature selection method.

• Archives of design research
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• v.18 no.1 s.59
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• pp.39-48
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• 2005

In the age of digital culture, TV broadcasting is exercising more influence as a information and communication medium compared to past. With the appearance of satellite broadcasting service in 2002, the broadcasting environment became a diversified field of local TV, cable TV, satellite, internet, etc. and created the time of multi-media and multi-channel. This ongoing change of broadcasting environment made the passive audience of the past, active image makers and new accepters, participants and users of communications, who know how to choose and use media as the active centerpiece, The active acceptor as the centerpiece of channel selections has become the center of the broadcasting, whereby they pick up and enjoy their favorite TV programs and came to remember the list of their favorite channels and zap them finally. In this point of spotting their favorite channels and improving the degree of recognition for the channels, the development of the noticeable brand for a particular program has made a great contribution. The aim of this study, therefore, is to recognize the factors, which are important in the habits of watching TV and to develop professional brands for TV broadcasting programs. The range of the survey for this study was home news programs and broadcasting stations abroad, which were on air from March to May in 2004. The focus of the survey was universal and professional news programs. Through this study, it was ascertained that, in the case of news, developing a brand for an anchor as well as for a professional brand of TV program could be an important element.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5C
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• pp.664-672
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• 2004

Widespread popularity of wireless data communication devices, coupled with the availability of higher bandwidths, has led to an increased user demand for content-rich media such as images and videos. Since such content often tends to be private, sensitive, or paid for, there exists a requirement for securing such communication. However, solutions that rely only on traditional compute-intensive security mechanisms are unsuitable for resource-constrained wireless and embedded devices. In this paper, we propose a selective partial image encryption scheme for image data hiding , which enables highly efficient secure communication of image data to and from resource constrained wireless devices. The encryption scheme is invoked during the image compression process, with the encryption being performed between the quantizer and the entropy coder stages. Three data selection schemes are proposed： subband selection, data bit selection and random selection. We show that these schemes make secure communication of images feasible for constrained embed-ded devices. In addition we demonstrate how these schemes can be dynamically configured to trade-off the amount of ded devices. In addition we demonstrate how these schemes can be dynamically configured to trade-off the amount of data hiding achieved with the computation requirements imposed on the wireless devices. Experiments conducted on over 500 test images reveal that, by using our techniques, the fraction of data to be encrypted with our scheme varies between 0.0244％ and 0.39％ of the original image size. The peak signal to noise ratios (PSNR) of the encrypted image were observed to vary between about 9.5㏈ to 7.5㏈. In addition, visual test indicate that our schemes are capable of providing a high degree of data hiding with much lower computational costs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12C
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• pp.1173-1183
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• 2006

In this paper, we propose an efficient method for improving visual quality of AR-FGS (Adaptive Reference FGS) which is adopted as a key scheme for SVC (Scalable Video Coding) or H.264 scalable extension. The standard FGS (Fine Granularity Scalability) adopts AR-FGS that introduces temporal prediction into FGS layer by using a high quality reference signal which is constructed by the weighted average between the base layer reconstructed imageand enhancement reference to improve the coding efficiency in the FGS layer. However, when the enhancement stream is truncated at certain bitstream position in transmission, the rest of the data of the FGS layer will not be available at the FGS decoder. Thus the most noticeable problem of using the enhancement layer in prediction is the degraded visual quality caused by drifting because of the mismatch between the reference frame used by the FGS encoder and that by the decoder. To solve this problem, we exploit the principle of cyclical block coding that is used to encode quantized transform coefficients in a cyclical manner in the FGS layer. Encoding block coefficients in a cyclical manner places 'higher-value' bits earlier in the bitstream. The quantized transform coefficients included in the ealry coding cycle of cyclical block coding have higher probability to be correctly received and decoded than the others included in the later cycle of the cyclical block coding. Therefore, we can minimize visual quality degradation caused by bitstream truncation by adjusting weighting factor to control the contribution of the bitstream produced in each coding cycle of cyclical block coding when constructing the enhancement layer reference frame. It is shown by simulations that the improved AR-FGS scheme outperforms the standard AR-FGS by about 1 dB in maximum in the reconstructed visual quality.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.539-554
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• 2002

To identify the trend of pediatric dentistry in USA and Japan, closely related to Korean pediatric dentistry. The Japanese Journal of Pediatric Dentistry(JJPD) and The Journal of the American Academy of Pediatric Dentistry(PD) were reviewed. We collected the bibliographical data of the articles published in the two journals from 1991 to 2000. We analyzed thematic distributions and chronological changes, and then compare those of two groups. The following results were obtained: 1. The 869 articles were published in JJPD and 672 in PD. This was about 30% more in JJPD. 2. In both JJPD and PD, the case reports were a quarter of scientific articles in quantity. 3. The studies on the systemic diseases had the highest proportion in both JJPD and PD. The studies on the dental caries and restorative materials also had high proportion in both journals. 4. The studies on the sedation and biochemical survey had high proportion in PD when had low proportion in JJPD. To the contrary, The studies on the behavior science in JJPD were about double of those in PD. 5. There was no statistically significant difference in quantity between JJPD and PD in the studies on the dental caries, prevention of dental caries, community dental survey, conservative treatment, restorative materials, pulp treatment, diagnosis and treatment of malocclusion, oral pathology and minor surgery, local anesthesia and nerve tissue, traumatic injuries. 6. There was statistically significant increase in the studies on the dental equipment in JJPD and in those on restorative materials in PD. 7. There was statistically significant decrease in the studies on the prevention of dental caries and local anesthesia and nerve tissue in JJPD, and those on conservative treatment in PD.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.4
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• pp.33-43
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• 2005

China Coastal Waters(CCW) usually appeared from June through October every years, and it appeared very strong in August. In the harmonic analysis for Sea level anomaly (SLA), the annual amplitude of the eastern part (8~9.5cm) in Jeju Island was lower than those of the western part (over 13cm). In the harmonic analysis for Sea Surface Temperature (SST), the annual amplitude of the eastern part($7{\sim}8.5^{\circ}C$) in Jeju Island was lower than those of the western part($5.5{\sim}6^{\circ}C$). For the Power Spectrum Density (PSD), SLA and SST remarkablely peaked on the annual period, semi-annual period and 3-monthly period. In summer and autumn, SLA of 1996 to 1999 was high in comparison to other years, and then it should be considered that the appearance of CCW was closely related to heavy rainfalls. The path of CCW formed this boundary of temperature between the yellow sea and the east china sea.

• KDI Journal of Economic Policy
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• v.14 no.1
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• pp.191-212
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• 1992

This paper discusses the role of money in the process of capital accumulation where financial markets are impeded by contract enforcement problems in the context of overlapping generations framework. In particular, in less developed countries (LDCs) creditors may know little about the repayment capability of potential debtors due to incomplete information so that financial instruments other than money may not acceptable to them. In this paper the impediments to the operation of the private finanical markets are explicitly modelled. We argue that creditors cannot observe actual investment decisions made by the potential borrowers, and as a result, loan contracts may not be fully enforceable. Therefore, a laissez-faire regime may fail to provide the economy with the appropriate financial instruments. Under these circumstances, we introduce a government operated discount window (DW) that acts as an open market buyer of private debt. This theoretical structure represents the practice of governments of many LDCs to provide loans (typically at subsidized interest rates) to preferred borrowers either directly or indirectly through the commercial banking system. It is shown that the DW can substantially overcome impediments to trade which are caused by the credit market failure. An appropriate supply of the DW loan enables producers to purchase the resources they cannot obtain through direct transactions in the credit market. This result obtains even if the DW is subject to the same enforcement constraint that is responsible for the market failure. Thus, the DW intervention implies higher investment and output. However, the operation of the DW may cause inflation. Furthermore, the provision of cheap loans through the DW results in a worse income distribution. Therefore, there is room for welfare enhancing schemes that utilize the higher output to develop. We demonstrate that adequate lump sum taxes-cum-transfers along with the operation of the DW can support an allocation that is Pareto superior to the laissez-faire equilibrium allocation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.4
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• pp.428-438
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• 2016

The aim of this study, in order to reduce the support burden of dementia primary caregiver, within the framework of long-term care insurance system to present its founding model for the development of new services. Previous research as analytical materials and based on the CARE study between 2012 to 2013. Primary caregiver burden of patient are both physical, psychological and economic aspects as well as difficulties in many aspects and had influence on many factors such as age, care burden, economic, health, and social support. It also came high-risk primary caregiver suffer from depression. This primary caregiver to take advantage of the elderly long-term care insurance system implemented at the time of the institutional support necessary for since 2008, presented additional services in this study. Of increasing the small sizes day care center (tentative name) to open an as established in the settlements at a scale of less than nine, within 5 minutes from the residence, limited dementia by expertise in the disease home care services scale model of the current system service It was to improve the quality of existing shares, small group sizes for day care centers and community life apart.

• International Commerce and Information Review
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• v.19 no.3
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• pp.3-23
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• 2017

With the globalization of the world economy, international trade networks are expanding beyond geographical proximity, and the expansion of such trade networks is playing a role in promoting globalization. Korea has established itself as a strong FTA for the past 13 years, starting with the Korea-Chile FTA. Successful establishment of a short-term FTA network has shown positive economic effects such as increased trade volume with partner countries and market share in overseas markets. Other countries are also turning to the paradigm of economic development through the formation of a regional economic integration and a bilateral trade agreement network, and it is time to investigate new opportunities through understanding the entire RTA and FTA network. In this study, we analyzed the status of RTA and FTA from the 1960s to 2010s, analyzed network structure and centrality through SNA(social network analysis). The results of the study show that the structure of the FTA network is gradually expanding, and the FTA network, which has been expanding to the center of the early European countries, is changing toward the Asian countries such as Korea, China and Japan. As a result of the analysis of the degree of centrality, Korea was ranked as the top in all the degree of centrality(Degree, Betweenness, Closeness and Eigenvector) indicators for a short period of time and it means that Korea's FTA strategy was evaluated as very successful. This study examines the FTA among the global RTAs, assesses the structure of the FTAs and evaluates Korea's FTA strategies and the FTA network from a network perspective.

• Korean Security Journal
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• no.10
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• pp.215-242
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• 2005

As CCTV can be an effective tool to prevent or suppress crime at low cost, they have been widesoread in developed countries. In spite of their effectiveness, they infringe some constitutional rights such as the right to privacy, the right of likeness and the right to control over personal information. The police and ward offices install CCTV in public areas to prevent crimes without a legal basis or standard. When information obtained in such a way is used as investigation data for the police or as an evidence in a court, it can cause serious trouble. To solve this problem, legal restriction on the installation of CCTV as should be clearer. Since current laws on public agencies' protection of personal information are too general, they are not effective enough to protect personal information. Therefore, Personal Information Protection Organic Act should be enacted to make a legal basis for protecting comprehensive personal information. It should be obvious who installs CCTVs, who pay for the cost and how they are managed. Before installation, the police and ward offices should obtain residents' consent through a public hearing or voting (on the range and purpose of installation), or conduct an impact assessment. During installation, CCTVs should be limited to prevent or suppress crimes, keep public order and void dangers. In case of making a sign of installation, it must specify its rights. After installation(operation/management phase), they should abide by principles of information protection and try not to infringe constitutional right. In the cognitive aspect, the police should constitutional rights must be secured although it is important to carry out their missions. The police should serve citizens and change to the police of communities. Citizens should understand that constitutional right can be infringed if public order is not maintained. When citizens cooperate with the police, they fear of crimes will decrease.