• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.267-271
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• 2005

The goal of data mining is to extract new and useful knowledge from large scale datasets. As the amount of available data grows explosively, it became vitally important to develop faster data mining algorithms for various types of data. Recently, an interest in developing data mining algorithms that operate on graphs has been increased. Especially, mining frequent patterns from structured data such as graphs has been concerned by many research groups. A graph is a highly adaptable representation scheme that used in many domains including chemistry, bioinformatics and physics. For example, the chemical structure of a given substance can be modelled by an undirected labelled graph in which each node corresponds to an atom and each edge corresponds to a chemical bond between atoms. Internet can also be modelled as a directed graph in which each node corresponds to an web site and each edge corresponds to a hypertext link between web sites. Notably in bioinformatics area, various kinds of newly discovered data such as gene regulation networks or protein interaction networks could be modelled as graphs. There have been a number of attempts to find useful knowledge from these graph structured data. One of the most powerful analysis tool for graph structured data is frequent subgraph analysis. Recurring patterns in graph data can provide incomparable insights into that graph data. However, to find recurring subgraphs is extremely expensive in computational side. At the core of the problem, there are two computationally challenging problems. 1) Subgraph isomorphism and 2) Enumeration of subgraphs. Problems related to the former are subgraph isomorphism problem (Is graph A contains graph B?) and graph isomorphism problem(Are two graphs A and B the same or not?). Even these simplified versions of the subgraph mining problem are known to be NP-complete or Polymorphism-complete and no polynomial time algorithm has been existed so far. The later is also a difficult problem. We should generate all of 2$^n$ subgraphs if there is no constraint where n is the number of vertices of the input graph. In order to find frequent subgraphs from larger graph database, it is essential to give appropriate constraint to the subgraphs to find. Most of the current approaches are focus on the frequencies of a subgraph: the higher the frequency of a graph is, the more attentions should be given to that graph. Recently, several algorithms which use level by level approaches to find frequent subgraphs have been developed. Some of the recently emerging applications suggest that other constraints such as connectivity also could be useful in mining subgraphs : more strongly connected parts of a graph are more informative. If we restrict the set of subgraphs to mine to more strongly connected parts, its computational complexity could be decreased significantly. In this paper, we present an efficient algorithm to mine frequent subgraphs that are more strongly connected. Experimental study shows that the algorithm is scaling to larger graphs which have more than ten thousand vertices.

• Journal of KIISE:Information Networking
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• v.36 no.1
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• pp.34-42
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• 2009

In this paper, we propose a practical hybrid transport error control scheme to provide SVC video streaming service over error-prone IP networks. Many error control mechanisms for various video coding standards have been proposed in the literature. However, there is little research result which can be practically applicable to the multilayered coding structure of SVC(the scalable extension of H.264/AVC). We present a new hybrid transport error control scheme that efficiently combines layered Forward Error Correction(FEC) and Automatic Repeat Request(ARQ) for better packet-loss resilience. In the proposed hybrid error control, we adopt ACK-based ARQ instead of NACK-based ARQ to maximize throughput which is the amount of effective data packets delivered over a physical link per time unit. In order to prove the effectiveness of the proposed hybrid error control scheme, we adopt NIST-Net network emulator which is a general-purpose tool for emulating performance dynamics in IP networks. It is shown by simulations over the NIST-Net that the proposed hybrid error control scheme shows improved packet-loss resilience even with much less number of overhead packets compared to various conventional error control schemes.

• The KIPS Transactions:PartC
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• v.17C no.3
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• pp.271-280
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• 2010

For the next generation mobile communication system, diverse wireless network techniques such as beyond 3G LTE, WiMAX/WiBro, and next generation WLAN etc. are proceeding to the form integrated into the All-IP core network. According to this development, Beyond 3G integrated into heterogeneous wireless access technologies must support the vertical handover and network to be used of several radio networks. However, unified management of each network is demanded since it is individually serviced. Therefore, in order to solve this problem this study is introducing the theory of Common Radio Resource Management (CRRM) based on Generic Link Layer (GLL). This study designs the structure and functions to support the vertical handover and propose the vertical handover algorithm of which policy-based and MCDM are composed between LTE and WLAN systems using GLL. Finally, simulation results are presented to show the improved performance over the data throughput, handover success rate, the system service cost and handover attempt number.

• Applied Biological Chemistry
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• v.51 no.3
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• pp.159-163
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• 2008

Xylogone sphaerospora ${\beta}$-mannanase was purified by Sephadex G-100 column chromatography. The specific activity of the purified enzyme was 8.44 units/ml protein, representing an 56.27-folds purification of the original crude extract. The final preparation thus obtained showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight was determined to be 42kDa. Konjac glucomannan was hydrolyzed by the purified ${\beta}$-mannanase, and then the hydrolysates was separated by activated carbon column chromatography. The main hydrolysates were composed of D.P. (Degree of Polymerization) 3 and 4 glucomannooligosaccharides. For elucidate the structure of D.P 3 and 4 glucomannooligosaccharides, sequential enzymatic action was performed. D.P 3 and 4 were identified as M-G-M and M-M-G-M (G- and M- represent glucosidic and mannosidic link-ages). To investigate the effects of konjac glucomannooligosaccharides on in vitro growth of Bifido-bacterium longum, B. bifidum, B. infantis, B. adolescentis, B. animalis, B. auglutum and B. breve. Bifidobacterium spp. were cultivated individually on the modified-MRS medium containing carbon source such as D.P. 3 and D.P. 4 glucomannooligosaccharides, respectively. B. longum and B. bifidum grew up 3.9-fold and 2.8-fold more effectively by the treatment of D.P. 4 glucomannooligosaccharides, compared to those of standard MRS medium. Especially, D.P. 4 was more effective than D.P. 3 glucomannooligosaccharide on the growth of Bifidobacterium spp.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.4
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• pp.79-85
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• 2007

Many countries foster the tour and leisure industries as a national strategic industry of the 21st century. The tour and leisure industry is expected to be reorganized from the land-based industry to the ocean-based industry as the GNP in a nation is over USD $20,000{\sim}30,000$ dollars. In Korea, since we adopt a five-day week, the total working hours for a week is shortened. As the result, leisure activities in family, such as experience tour, ecological tour, travel, and overnight tour, are expected to be increased. Leisure and sports tours, which link the tour and sports to rafting, hang gliding, and marine leisure, have been also increased over 21.6%. A number of small and big islands near Ho-Nam coastal areas play an important role as natural breakwater. Thus, the ports in Ho-Nam area is safely protected from physical effects by ocean waves and is maintained without constructing a breakwater. In this paper, we analyses the required conditions as the marine leisure base in the southwest sea area which has the natural advantages for marine leisure. We also discuss how to activate the yacht business on Ho-Nam coast area. And then we analyse the present situations and obstacles of a domestic marine leisure. We also suggest the plan to build up echo-marine leisure infrastructure for industrial growth of marine leisure in Ho-Nam area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.367-373
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• 2017

The O2O service is an efficient way to operate based on systematic connection of the offline and online states. At present, education, health checkups, and exposure management of radiation workers are separated from offline and online at nuclear-related workplaces. Therefore, we developed a radiation workers management program at the workplace and tried to link online and offline states. After applying the program to the local network, we developed a written employee management system as a computer program and applied it to radiation workers and radiation safety managers at a university hospital in Daejeon using a questionnaire. As a result of the survey, the results of this program can enhance the awareness of safety management and work convenience. There is also a demand for radiation closed workers as well as radiation relative workers. It will be necessary to collect opinions regarding the characteristics of each workplace for the generalization of the radiation workers management program. As a result, real-time radiation safety management and work improvement can be expected through network connections between the workplace, supervisory authority, and related organizations in the future. If a circle structure is formed using the employee management program, development of radiation safety management can be expected.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.639-654
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• 2014

What is noticeable in Changgeuk Madame Ong is that for "narrativization," a main character is replaced with Madame Ong and her mother and a reinvented story as a result thereof is the female liberation from oppression. The director sought for the completeness of the narrative with a plot line created (i) by daringly deleting the latter half (episode relating to Gangsoe's death), which was a persistent problem unsolved both in the original and its derivative contents, (ii) by diluting Gangsoe's patriarchal authority and thereby creating the ending of endless love and the fruition of love, and (iii) by severing the link between Madame Ong's doomed fate of widowhood and Gangsoe's doomed fate of death by the violation of a taboo (the key factors of the original story) and at the same time, thereby inserting the doomed fate of death by Jowang (god of fire), declaring a war against jangseung (Korean traditional totem pole), the aesthetic structure representing "fictionization," and enabling a female character to gain love, fame and life through free will and spirit of resistance. The director achieved a remarkable success in terms of composition by (i) taping into a variety of genres of music, (ii) by maximizing the effect of Madame Ong's solo, (iii) by strengthening the "uniqueness of each part" through chorus, (iv) by creating a dramatic atmosphere for the change of scene, (v) by applying a dual variation of tension (resistance theme) and relaxation (freedom theme), etc.

• The Journal of the Korea Contents Association
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• v.17 no.12
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• pp.1-10
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• 2017

Open data has received a lot of attention from around the world. The Korean government is also making efforts to open government data. However, despite the quantitative increase in public data, the lack of data is still pointed out. This paper proposes a method to improve data sharing and utilization by semantically linking public data. First, we propose a knowledge model for expressing administrative districts and their semantic relationships in Korea. An administrative district is an administrative unit that divides the territory of a nation, which is a unit of politics, according to the purpose of the state administration. The knowledge model of the administrative district defines the structure of the administrative district system and the relationship between administrative units based on the Local Autonomy Act. Second, a knowledge graph of the administrative districts is introduced. As a reference information to link public open data at a semantic level, some characteristics of a knowledge graph of administrative districts and methods for linking heterogeneous public open data and improving data quality are addressed. Finally, some use cases are addressed for interlinking between the knowledge graph of the administrative districts and public open data. In particular, national administrative organisations are interlinked with the knowledge graph, and it demonstrates how the knowledge graph can be utilised for improving data identification and data quality.

• Journal of Intelligence and Information Systems
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• v.24 no.3
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• pp.119-134
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• 2018

A knowledge map as the taxonomy used in a knowledge repository should be structured to support and supplement knowledge activities of users who sequentially inquire and select knowledge for problem solving. The conventional knowledge map with a hierarchical structure has the advantage of systematically sorting out types and status of the knowledge to be managed, however it is not only irrelevant to knowledge user's process of cognition and utilization, but also incapable of supporting user's activity of querying and extracting knowledge. This study suggests a methodology for constructing a networked knowledge map that can support and reinforce the referential navigation, searching and selecting related and chained knowledge in term of contents, between knowledge. Regarding a keyword as the semantic information between knowledge, this research's networked knowledge map can be constructed by aggregating each set of knowledge links in an automated manner. Since a keyword has the meaning of representing contents of a document, documents with common keywords have a similarity in content, and therefore the keyword-based document networks plays the role of a map expressing interactions between related knowledge. In order to examine the feasibility of the proposed methodology, 50 research papers were randomly selected, and an exemplified networked knowledge map between them with content relevance was implemented using common keywords.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.12
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• pp.1250-1260
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• 2014

In this paper, a novel resource scheduling, which is used for hub network based long distance airborne tactical communication, is proposed. Recently, some countries of the world has concentrated on developing data rate and networking performance of CDL, striving to keep pace with modern warfare, which is changed into NCW. And our government has also developed the next generation high capacity CDL. In hub network, a typical communication structure of CDL, hybrid FDMA/TDMA can be considered to exchange high rate data among multiple UAVs simultaneously, within limited bandwidth. However, due to different RTT and traffic size of UAV, idle time resource and unnecessary packet transmission delay can occur. And these losses can reduce entire efficiency of hub network in long distance communication. Therefore, in this paper, we propose RTT and data traffic size based UAV scheduling, which selects time/frequency resource of UAVs by using iterative sorting algorithm. The simulation results verified that the proposed scheme improves data rate and packet delay performance in low complexity.