• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.91-99
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• 2014

The main game architectures for multiplayer online games are the traditional client-server architectures, multi-server architectures and P2P(peer-to-peer) architectures. P2P architectures, due to their distributed and collaborative nature, have low infrastructure costs and can achieve high scalability as well as fast response time by creating direct connections between players. However, P2P architectures face many challenges. Distributing a game among peers makes maintaining control over the game more complex. These architectures also tend to be vulnerable to churn and cheating. Providing consistency control in P2P systems is also more difficult since conflicting updates might be executed at different sites resulting in inconsistency. In order to avoid or correct inconsistencies, most multiplayer games use a primary-copy replication approach where any update to the object has to be first performed on the primary copy. This paper presents the primary-copy model with the update dissemination mechanism that provides consistency control over an object in P2P architectures for multiplayer online games. The performance for this model is evaluated through simulation experiments and analysis.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.37-43
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• 2015

Technical treatments of image contents on the web include the copy protection method such as the image capture protection technology and the traitor tracing method to detect unauthorized duplications through watermarking insertion or feature information technology. However, these two methods have their own weaknesses. The image capture protection method is unable to protect illegal captures when the URLs of image sources are exposed. The traitor tracing method is fundamentally unable to protect illegal captures due to its post-treatment method. Besides, the weakness of using the copyright information display technology involves easy removal of copyright information from copyrighted contents. This paper suggests a model of the web image contents protection system which makes it hard to separate copyright information from web image contents and allows image contents to be shown only in the authorized websites.

• Journal of Information Management
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• v.36 no.4
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• pp.199-215
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• 2005

Experts participating in the knowledge expert network externalize their implicit knowledge by providing information or writing reports. Almost all the members of the network share externalized knowledge and the network facilitate the dissemination and diffusion of knowledge. Individuals reproduce another implicit knowledge by internalizing shared knowledge through the network and re-created knowledge is externalized, establishing knowledge circulation. In this paper, we analyze the expert groups of the Global Network of Korean Scientists & Engineers(KOSEN, www.kosen21.org), the Korea's No. 1 science and engineering knowledge expert community, with the application of the theory of policy network proposed by Marsh & Rhodes. According to the principal standards of policy network classification such as the number of participants, interaction among participants, consistency, distribution of resources and dependency, we categorize the KOSEN expert groups as closed policy network and opened issue network, and divide closed policy network into core community and periphery community.

• Journal of Korean society of Dental Hygiene
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• v.13 no.4
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• pp.623-629
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• 2013

Objectives : The aim of the study is to investigate the health belief model affecting the oral health behavior in elementary school students by applying health belief model. Methods : Subjects were 216 elementary school students including 6th grade 103 boys and 113 girls in Gyeonggi-do from February 1 to February 28, 2013. They completed self-reported questionnaires after receiving informed consents. Results : Oral health belief model showed cues to action($20.39{\pm}3.11$), benefits($19.63{\pm}3.37$), self-efficacy($16.62{\pm}2.60$), severity($14.53{\pm}3.94$), susceptibility($14.31{\pm}4.62$), and barrier($11.74{\pm}3.85$). Oral health belief revealed the lower the level of barrier(p=0.004) and the higher cues to action, Benefits and self-efficacy were the best oral health behavior(p=0.000). The most influencing factors of oral health belief were self-efficacy(0.267) and Cues to action(0.239). Conclusions : Children's oral health belief is associated with oral health behavior. children's self efficacy and cues to action toward oral care influenced on oral behavior. It is important to enhance the recognition toward self efficacy and cues to action by following recommended behavior and effective health educational program.

• Journal of the Korea Computer Industry Society
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• v.5 no.8
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• pp.781-790
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• 2004

This paper describes intrusion detection rule mangement using mobile agents. Intrusion detection can be divided into anomaly detection and misuse detection. Misuse detection is best suited for reliably detecting known use patterns. Misuse detection systems can detect many or all known attack patterns, but they are of little use for as yet unknown attack methods. Therefore, the introduction of mobile agents to provide computational security by constantly moving around the Internet and propagating rules is presented as a solution to misuse detection. This work presents a new approach for detecting intrusions, in which mobile agent mechanisms are used for security rules propagation. To evaluate the proposed appraoch, we compared the workload data between a rules propagation method using a mobile agent and a conventional method. Also, we simulated a rules management using NS-2(Network Simulator) with respect to time.

• Proceedings of The Korean Society of Health Promotion Conference
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• 2009.05a
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• pp.87-87
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• 2009

2008년부터 화성시에서는 담배연기 없는 맑은 화성 만들기 사업에 착수하였다. 이는 흡연으로 인한 사망 및 질환 유병의 감소, 간접흡연에의 노출, 감소 개인행위 통제를 위한 역량 강화, 지역사회 협력체계 구축 및 지원적 환경의 조성을 목적으로 하고 있다. 포괄적 흡연통제프로그램 모델을 기반으로 하여 각기 적합한 환경을 위한 수행전략과 실행계획을 수립하였다 ; 담배연기 없는 환경조성, 홍보 및 캠페인, 금연클리닉을 통한 교육, 상담의 금연프로그램 운영, 모니터링과 평가, 사업관리를 위한 지침과 교육 등. 2008년 1년 동안 총 1714명이 금연클리닉을 방문하였으며, 이중 90%는 금연시도 4주간, 57%는 6개월 동안 금연상태를 유지하였다. 6개월 동안 금연상태를 유지한 대상 중 67%는 50세 이하 연령이었으며, 6개월 동안 금연상태를 유지한 대상 중 28%에게는 행동수정요법을 적용하였다. 금연환경 조성을 위해 지역사회내 건물과 시설을 모니터링하였으며, 경로당, 유치원, 초등학교, 문화재 등과 같은 특정 환경에 초점을 맞춘 교육과 관리를 수행하였다. 또한 2009년 사업추진방향설정을 위해 지역사회주민들 대상으로 하는 금연정책에 대한 전화조사를 실시하였다. 건강한 도시를 구축하기 위해서는 모든 지역사회구성원을 대상으로 하는 다양하고 효과적인 프로그램을 지속적으로 추진하는 것이 필요하다. 특히 학생, 가족, 학교, 지역사회와 정부간의 담배 없는 화성을 만들기 위한 협력적 관계 구축이 무엇보다 중요하다고 할 수 있다. 향후 보다 나은 사업추진을 위해 현상황에 대한 분석을 토대로 적절한 전략을 개발하는 것이 필요하다.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.363-367
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• 2009

We propose Cubical User Interface(CUI) for toy block composition in Augmented Reality. The creation of new object by composing virtual object is able to construct various AR contents effectively. However, existing GUI method requires learning time or is lacking of intuitiveness between act of user and offered interface. In case of AR interfaces, they mainly have been supported one handed operation and it did not consider composition property well. Therefore, the CUI provide tangible cube as the manipulation tool for virtual toy block composition in AR. The tangible cube which is attached multi-markers, magnets, and buttons supports free rotation, combination, and button input. Also, we propose two kinds of two-handed composing interactions based on CUI. First is Screw Driving(SD) method which is possible to free 3-D positioning and second is Block Assembly(BA) method which support visual guidance and is fast and intuitive. We expected that proposed interface can apply as the authoring system for content such as education, entertainment, Digilogbook.

• Korean Journal of Cognitive Science
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• v.11 no.2
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• pp.19-35
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• 2000

Learning by examples has proven to be an efficient method in mastering various subjects including programming languages. This study hypothesizes that the number of examples and the type of examples are two significant dimensions that influence the performance of learning programming languages by examples. A set of experiments was conducted to investigate the impacts of the two dimensions in the domain of JAVA programming. The results showed that providing two examples is more effective than providing only one example even though significantly more explanations are attached to the single example. Among the 'two-example' groups, the group that was given functionally similar examples performed better than those with functionally dissimilar examples. Explanations for these results are provided in this paper based on the behavioral patterns of individual subjects in terms of time and frequency. This paper concludes with the implications of the study results for the development of effective tutoring systems for programming languages.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.5
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• pp.1141-1151
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• 2018

In an APT attack, the communication stage between infected hosts and C&C(Command and Control) server is the key stage for intrusion into the attack target. Attackers can control multiple infected hosts by the C&C Server and direct intrusion and exploitation. If the C&C Server is exposed at this stage, the attack will fail. Therefore, in recent years, the Domain Generation Algorithm (DGA) has replaced DNS in C&C Server with a short time interval for making detection difficult. In particular, it is very difficult to verify and detect all the newly registered DNS more than 5 million times a day. To solve these problems, this paper proposes a model to judge DGA-DNS detection by the morphological similarity analysis of normal DNS and DGA-DNS, and to determine the sign of APT attack through it, then we verify its validity.

• Archives of design research
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• v.16 no.2
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• pp.171-178
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• 2003

The visual, sensible and social situation that the modern digital technologies create became the background for the works of architects in extreme modernism and their space modeling suggested another possibility that was emancipated from the restriction of a property of matter and gravity in the existing space. The architecture design process using the digital technology has been attempted in diverse ways and summarized with several characteristics such as displacement, nonlinear space, flexibility of space and non-Euclidean geometry system. However, the conceptual and very technical design process that is called as digital architecture has been indiscriminately used with mixed meanings and the common features and differences between works and theories are not studied. This study aims to classify and identify the digital architecture by type as analyzing the non-linear composition process that is common in the digital architecture.