• Journal of KIISE:Computing Practices and Letters
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• v.13 no.2
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• pp.86-99
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• 2007

Packet filtering is to filter out potentially malicious network packets. In order to test a packet filtering function we should verify whether security policies are performed correctly as intended. However there are few existing tools to test the function. Besides, they need user participation when generating test cases or deciding test results. Many security administrators have a burden to test systematically new security policies when they establish new policies or modify the existing ones. To mitigate the burdens we suggest a new test method with minimal user articipation. Our tool automates generation steps of the test cases and the test oracles, respectively. By using the test oracles generated automatically, deciding test results is possible without user intervention. Our method realizes an automatic testing in three phases; test preparation phase, test execution, and test evaluation. As a result it may enhance confidence of test activities more highly. This paper describes the design and implementation of our test method and tool.

• Journal of KIISE:Information Networking
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• v.36 no.6
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• pp.481-491
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• 2009

In this paper, we proposed a hybrid P2P overlay structure for live media streaming. The proposed structure consists of the mesh overlay organized by peers according to the geographical proximity and similar bandwidth range and the tree overlay formed by the peers for which the stability of participation is approved. The proposed scheme enhances the robustness of tree overlay and the long delay of mesh overlay by intelligently combining the utilization of the tree overlay and the mesh overlay. Furthermore, the peers with a large up-link bandwidth are located near to the media source peer. Therefore, it reduces the height of tree, and as a result, the stream transmission delay. Through simulation, we evaluated the performance of the proposed scheme in terms of scalability and quality of services.

• Journal of Internet of Things and Convergence
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• v.5 no.2
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• pp.67-72
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• 2019

As Internet voting can take place regardless of a voter's location, the participation rate of the voters would be increased and economic costs will be reduced. But the drawback of it is that all participants have to trust the election management server. If the server colludes with the specific candidate, the other candidates cannot prove rigged election. In addition, majority of researches on Internet voting are mainly focused on the voting restricted by the region and the country. Thus, it's not appropriate for the election in Internet community such as YouTube channels. As the Internet community is composed of members from all around the world, the new type of voting model is needed. In this study, we propose the smart contract based Internet voting model applicable on the blockchain network. The proposed smart contract model consists of candidate registration, voter registration, voting and counting stages. In the proposed model, anonymity of the voter is assured in the voter registration and voting stages, and all candidates can confirm the fairness of the election in the counting stage.

• Informatization Policy
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• v.20 no.4
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• pp.3-22
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• 2013

This study analyzed the research trends and methodologies through meta analysis method on the issues of ICT policy and e-government in Korean major journals and proceedings including Korean Association of Public Administration (KAPA), Korean Association of Policy Studies (KAPS), and Korean Journal of Information Policy of NIA (National Information Agency). The results showed that methodology has changed from explorative study with conceptualization to experimental study with theoretical model and cases. Qualitative approaches including case studies and description with policy implications were employed more as analyses tools. In terms of contents, system effectiveness and e-governance issues prevailed in the early 2000s, and since then, it has changed into ICT-based social changes and looking for generalization of theories including e-democracy, e-service, e-participation, digital divide, and post-information society. Now we are facing another ICT revolution of social network via web3.0 and gov3.0 and it is time to open a new theoretical debate, deconstruction of discourse, and collaborative perspective among different disciplines.

• Journal of the Korea Computer Graphics Society
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• v.18 no.3
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• pp.29-35
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• 2012

As the distribution rate of the Smart mobile increased, the software technology and ideas for the ubiquitous systems advanced day after day to establish an environment where the public can easily access and experience such technologies. The communication between an individual and the many became more convenient through the social network services (SNS) and the individuals started to attempt to communicate in various methods. The communication methods and techniques became more diverse and the media art pieces focusing on the communications among many also became more interesting. This study attempted to create a prototype of the visual communication media art through the indirect participation of one of the widespread SNS, Twitter, for the communication and also to suggest the direct and indirect communication routes among the humans. In addition, the use of the typography in the pieces also attempted to examine a new type of work that combines the SNS and media art while delivering the text messages.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.99-114
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• 2012

Proxy Mobile IPv6 (PMIPv6) has received considerable attention between telecommunications and the Internet communities and does not require active participation of the Mobile Node (MN) by way of network-based mobility management. The PMIPv6 domain is studying establishment in progress to support extensively a number of MN by using a low handover latency. In this research, we are propose a novel 3S scheme for building Scalable and Secure and Seamless PMIPv6 domains. In the proposed scheme, all of Mobility Access Gateway (MAG) are acting as the Local Mobility Anchor (LMA) and composing a virtual ring with another MAG. General hashing is used in the efficient distribution-mapping between each MN and the MN's LMA of all MAGs. And, MAG and MN are authenticated using the symmetric key. Through mathematical analysis, we verifies the safety, scalability, and seamless service for 3S. Also, we're propose a handover procedure of 3S and show better than the existing schemes in terms of handover latency.

• 한국정보교육학회:학술대회논문집
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• 2011.01a
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• pp.211-217
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• 2011

Recent IT (information technology) environmental changes, such as emerging social network services or increasing user participation in multimedia environment, have made it necessary for e-learning systems to undergo changes in various ways. Metadata is an agreement for interoperability between different systems. The standardization of metadata for e-learning system has been driven by some domestic and international organizations, but applying diverse environmental changes into the design of e-learning metadata is in dire need. In this paper, we present a methodology for the analysis and design of modeling e-learning metadata and elicit the design requirements, on the basis of the metadata standard KEM 3.0, about the elements that are expected to be needed in future e-learning systems. Based on the requirements from the analysis, we present the three-layer model for classifying the requirements by the importance of metadata elements per Kana Model. An intelligent e-learning system is to be developed based on the proposed modeling design, which we hope to influence the development of an international standard in the future.

• Journal of the Korean Society of Costume
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• v.67 no.4
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• pp.131-152
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• 2017

The purpose of this study is to analyze modern fashion culture in the 20th century through changes in transmedia in order to better understand characteristics of fashion contents. The study also strived to identify the characteristics of remediation in modern fashion and media by exploring the cultural code, and use it to establish an integrated view. The subjects and the method of the study are as follows. First, the study analyzed the development of transmedia and fashion culture since the 20th century. Second, it identified the transitional characteristics of transmedia. Third, the study analyzed the characteristics of remediation in modern fashion culture by using the characteristics of mediation, which appeared with the transitional characteristics of transmedia. The study results are as follows. First, the types of remediation are 'borrowing,' 'Representation,' 'Expansion,' 'Refashion,' and 'Absorb.' In old and new media, each type can be aesthetically experienced in 'transparency,' opaqueness,' 'Hypermediacy,' and 'Immediacy.' Second, fashion culture can undergo a transformation from its original form to a second and a third iteration, and this process allows for possibility of an expansion of multiple plots and well-rounded character settings. This opens up the possibility for fashion consumer participation, and signifies a transition into an environment where expansion of time and space is possible. The third finding is the non-mediation of fashion objects. The mediating relationship between clothes and media is directly connected to the development of new media. The immersion of new media by fashion consumers has the characteristics of 'transparency'/'Non-mediation,' and the reinterpretation and reproduction of original fashion styles have the characteristics of 'opaqueness'/'Hyper-mediation.' Fourth, fashion culture has data variability. Through 'Borrowing,' 'Representation,' 'Expansion,' 'Remodeling,' and 'Absorption,' the cultural hierarchy of reproduced fashion forms a multi-layered integrated network. Mediation code, which repurposes fashion culture contents, also creates new media fashion through transmedia.

• The Mathematical Education
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• v.45 no.3 s.114
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• pp.295-313
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• 2006

University teacher education programs have sought for ways of how to improve student teaching in order to supply mathematics teachers with practical theory to achieve the goals of the current educational reform in school mathematics. In this context, the purpose of this research is to investigate the effect of student teachers' teaching experience in the after-school mathematics programs and the ways of how to develop the after-school learning programs as an effective site for learning to teach based on the inquiry into student teachers' own teaching experience. For the purpose, data were collected through the interviews with the student teachers who had taught after-school mathematics class. In addition, data were collected through survey, class observation, and seminal meetings with the student teachers in order to supplement the findings from the interview analysis. Data analysis focused on the student teachers' experience with teaching in after-school mathematics classes, that is, what and how they had learned as teachers, what kinds of difficulties they encountered in their teaching and supports that they expect to improve their learning through teaching. The analysis shows that the teaching experience in the after-school programs had positively contributed to their development as future mathematics teachers. Specifically, the after-school programs provide the site for learning through teaching at the early stage of teacher education program. The after-school programs provided the students teachers for the opportunity to participate peripherally in educational practice of school. Through the participation, the student teachers developed positive attitudes toward teaching career and became to have more solid ideas about how to teach mathematics. Based on the analysis, this research provides following suggestions concerning how to improve student teaching. First, it is necessary to provide student teachers to participate into the practice of teaching at the early stage of teacher education programs. Second, it is important to give students teacher opportunity to participate in teaching at peripheral and legitimate positions. Finally, it is necessary to construct mentoring networks to support student teachers to move from a peripheral position toward a center of teaching practice.

• Journal of Preventive Medicine and Public Health
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• v.41 no.1
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• pp.1-9
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• 2008

Objectives : This study evaluated knowledge structure and its effect factor by analysis of co-author and keyword networks in Korea's preventive medicine sector. Methods : The data was extracted from 873 papers listed in the Journal of Preventive Medicine and Public Health, and was transformed into a co-author and keyword matrix where the existence of a 'link' was judged by impact factors calculated by the weight value of the role and rate of author participation. Research achievement was dependent upon the author's status and networking index, as analyzed by neighborhood degree, multidimensional scaling, correspondence analysis, and multiple regression. Results : Co-author networks developed as randomness network in the center of a few high-productivity researchers. In particular, closeness centrality was more developed than degree centrality. Also, power law distribution was discovered in impact factor and research productivity by college affiliation. In multiple regression, the effect of the author's role was significant in both the impact factor calculated by the participatory rate and the number of listed articles. However, the number of listed articles varied by sex. Conclusions : This study shows that the small world phenomenon exists in co-author and keyword networks in a journal, as in citation networks. However, the differentiation of knowledge structure in the field of preventive medicine was relatively restricted by specialization.