• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.939-955
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• 2010

With the progress of IT and mobile positioning technologies, various types of location-based services (LBS) have been proposed and implemented. Finding a shortest path between two nodes is one of the most fundamental tasks in many LBS related applications. So far, there have been many research efforts on the shortest path finding problem. For instance, $A^*$ algorithm estimates neighboring nodes using a heuristic function and selects minimum cost node as the closest one to the destination. Pruning method, which is known to outperform the A* algorithm, improves its routing performance by avoiding unnecessary exploration in the search space. For pruning, shortest paths for all node pairs in a map need to be pre-computed, from which a shortest path container is generated for each edge. The container for an edge consists of all the destination nodes whose shortest path passes through the edge and possibly some unnecessary nodes. These containers are used during routing to prune unnecessary node visits. However, this method shows poor performance as the number of unnecessary nodes included in the container increases. In this paper, we focus on this problem and propose a new border line-based pruning scheme for path routing which can reduce the number of unnecessary node visits significantly. Through extensive experiments on randomly-generated, various complexity of maps, we empirically find out optimal number of border lines for clipping containers and compare its performance with other methods.

• Health Policy and Management
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• v.30 no.2
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• pp.192-198
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• 2020

Background: Korea National Health Insurance Service (NHIS) is operated as a social insurance system in which people pay a portion of their monthly income as insurance premiums and receive benefits when they experience illness or injury. Since 2005, the national health insurance remained surplus accumulating cumulative reserves each year. However, as of 2018, NHIS revenue recorded 62.11 trillion won and spending of 62.29 trillion won. The deterioration of NHIS finances is expected to accelerate with the aging population, income growth, new medical technology development, and enhanced security policies. Methods: To examine the financial health and sustainability of NHIS, we estimated the future revenue and spending until 2030 using the data from Korea Health Insurance Review and Assessment Service statistical yearbook. 2004-2018 average percentage change in NHIS revenue and spending was calculated. We estimated the future NHIS financial status using two methods. In the first method, we calculated the revenue and spending of the future NHIS by applying the 2004-2018 average percentage change to the subsequent years consecutively. In the second method, we estimated the future NHIS financial status after adjusting for the predicted demographic changes such as the aging population and declining birth rate in South Korea. Results: The estimates from this study suggest that the NHIS's cumulative reserves will run out by 2024. Conclusion: In terms of spending on current health insurance, there should be a search for ways of more efficient spending and funding options.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.405-413
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• 2016

To solve various problems of the Internet as well as to enhance network performance, various future Internet architectures utilize cached data in network nodes or in proxy servers. Named-data networking (NDN), one of future Internet architectures, implements in-network data caching functionality, and then responds itself to request messages. However, it can cause users' privacy invasion that the publisher of data can not engage in the sharing/using process of the data anymore after the data was cached in-network. So NDN implements both encryption-based access control and group access control. But, since such access control schemes need to exchange additional messages in order to search for a proper access control list and keys, it causes inefficiency. This paper surveys the access control schemes of NDN, and then proposes an improved scheme.

• Journal of Korean Society on Water Environment
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• v.30 no.2
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• pp.226-241
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• 2014

This study proposes schemes of GIS-based system development for integrated information management in water environment linked with Korean Reach File (KRF). For this purpose, precedent studies and systems of the U.S. were investigated and analyzed to induce optimal methodology for Korean circumstances. Thereafter, data linkage methods of KRF and Water Environment Information System (WEIS), system configuration plans, application development plans, and KRF improvement and maintenance plans were considered. For data linkage and system configuration, three methods were suggested: an overlay operation-based data linkage method, entering spatial addresses into the existing DB, and creating link information between KRF and the existing DB. The first method was predicted to be the most effective for system implementation, the second method is advantageous for search tasks, and the third method is advantageous for system security and maintenance. Various types of applications should be developed in the consideration of the types of the users and their usages. Moreover, there is a need for further research on regular renewal of KRF, standard development, expansion of construction areas, etc. Based on the present results, research on actual system design and development also should be conducted for supporting Total Maximum Daily Loads (TMDLs).

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.4
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• pp.183-198
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• 2011

With the recent development of IT technology, the existing contents have been digitalized through various distribution channels. Accordingly, a lot of studies have been done in order to figure out the distribution and features of digital contents, In these studies, however, categorical characteristics of digital contents were not considered ; most of the previous researchers saw digital contents as only a single item or focused on some contents within particular part such as movie, music, etc. So, this study divides digital contents into movies, music and texts. I was going to study which factors affect Customer Satisfaction in relation with the kind of contents. With SERVQUAL as independent variables, which affect the Customer satisfaction, I used five factors :Design Quality, Information Quality, Security Quality, Communication Quality and Transaction Quality. As for the detailed items, I corrected them with Open-End Question and Pre Survey Research, which are more fit into the features of digital contents. This research conducted Principle Component Analysis, Reliability Test, Correlation Analysis and Regression Analysis. I verified that each factor of Service Qualities has a positive effect on Customer Satisfaction. Moreover, the factors of the effect are different according to the kind of digital contents. This paper was added Exploratory Study to find the best distribute channel. For the study, I search the possible distribute channel in each digital contents and their characteristic.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.167-173
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• 2011

Most of the terminologies used in medical domain is not intended to be applied directly in clinical setting but is developed to integrate the terms by defining the reference terminology or concept relations between the terms. Therefore, it is needed to develop the subsets of the terminology which classify categories properly for the purpose of use and extract and organize terms with high utility based on the classified categories in order to utilize the clinical terms conveniently as well as efficiently. Moreover, it is also necessary to develop and upgrade the terminology constantly to meet user's new demand by changing or correcting the system. This study has developed a mapping tool that allows accurate expression and interpretation of clinical terms used for medical records in electronic medical records system and can furthermore secure semantic interoperability among the terms used in the medical information model and generate common terms as well. The system is designed to execute both 1:1 and N:M mapping between the concepts of terms at a time and search for and compare various terms at a time, too. Also, in order to enhance work consistency and work reliability between the task performers, it allows work in parallel and the observation of work processes. Since it is developed with Java, it adds new terms in the form of plug-in to be used. It also reinforce database access security with Remote Method Invocation (RMI). This research still has tasks to be done such as complementing and refining and also establishing management procedures for registered data. However, it will be effectively used to reduce the time and expenses to generate terms in each of the medical institutions and improve the quality of medicine by providing consistent concepts and representative terms for the terminologies used for medical records and inducing proper selection of the terms according to their meaning.

• Journal of the Korea Society of Computer and Information
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• v.18 no.5
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• pp.103-111
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• 2013

This paper provide a framework for an IGILMS(internet-based global integrated logistics management system) which can access and mediate cargo transportations among small- and medium-sized domestic/international logistics corporations as regards cargo, registration and search for space, public tender and negotiation, contract, payment and safety-guarantee, transportation through the internet, wireless communication means, or smart phone etc. In addition, we describe a model to provide customized services in the B2B e-market for IGILMS and the structure and the control of its fulfillment process, and provide technical architecture of the IGILMS for an internet-based global logistics management system. To validate an efficiency of the proposed system, we develop a simulation model and analyze the performance of the proposed system.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.26.1-26.10
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• 2018

Background: This study aimed to evaluate the mechanical, biological, and esthetic stability of a zirconium abutment according to evidence-based dentistry. Main text: An electronic search was performed. Domestic studies were found using the keywords "zirconia abutments" and "zirconium abutment" in KMbase, KoreaMed, and the National Assembly Library, and international studies were found using the same keywords in PubMed. All identified studies were divided by evidence level from the viewpoint of the research type utilizing the evidence-based review manual. A total of 102 domestic studies (with Korean language) were found, and 9 of these studies were selected. In these nine studies, 3 had evidence level 3 and 6 had evidence level 4. A total of 97 international studies (with English language) were found, and 19 were selected. Among these 19 studies, 5 had evidence level 2 and 7 had evidence level 3, whereas the remainder had evidence level 4. According to the studies, zirconium abutments are mechanically, biologically, and esthetically stable, but the evidence level of these studies is low, and the follow-up duration is no longer than 5 years. Conclusions: All examined studies verified the mechanical stability of zirconium abutments for a period no longer than 5 years. Therefore, a long-term clinical observation is needed. Zirconium abutments are thought to be biologically stable, but they are not superior to titanium abutments. As the esthetic stability of such abutments had a low evidence level in the studies that examined here, a much higher evidence level is needed.

• Journal of Digital Convergence
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• v.11 no.9
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• pp.189-194
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• 2013

Semantic Web is what supports a search, data integration, and automated web service by developing technology of giving help so that a computer can understand information a little more on the web. As amount of information gets growing and diverse, there is a problem of offering by efficiently extracting and processing only information proper for users' demand. Semantic Web isn't what is distinguished completely from the existing web. It gives a meaning, which was well defined, to information of being inserted on web by expanding the current web. Through this, a computer and a person come to perform work cooperatively. To implement Semantic Web, the limit of HTML needs to be overcome. The existing access authorization has not taken information and semantics into account due to the limitations of HTML. It is difficult to expand or integrate many relevant documents by using HTML. Program or software agent, not a person, cannot extract a meaning of document automatically. This study suggests a method of Access Authorization Policy Management that is in the Semantic Web configuration. Accordingly, the policy, which was designed in this study, improved the authorization process more than the existing method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.394-402
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• 2010

At a recent, enterprises based on online-service are established because of rapid growth of information network. These enterprises collect personal information and do customer management. If customers use a paid service, company send billing information to customer and customer pay it. Such circulation and management of information is big issue but most companies don't care of information security. Actually, personal information that was managed by largest internal open-market was exposed. For safe customer information management, this paper proposes the method that decrease load of RSA cryptography algorithm that is commonly used for preventing from illegal attack or hacking. The method for decreasing load was designed by Binary NAF Method and it can operates modular Exponentiation rapidly. We implemented modular Exponentiation algorithm using existing Binary Method and Windows Method and compared and evaluated it.