• Journal of Communications and Networks
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• v.16 no.6
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• pp.656-666
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• 2014

In delay tolerant networks (DTNs), delay is inevitable; thus, making better use of buffer space to maximize the packet delivery rate is more important than delay reduction. In DTNs, epidemic routing is a well-known routing protocol. However, epidemic routing is very sensitive to buffer size. Once the buffer size in nodes is insufficient, the performance of epidemic routing will be drastically reduced. In this paper, we propose a buffer scheme to optimize the performance of epidemic routing on the basis of the Lagrangian and dual problem models. By using the proposed optimal buffer scheme, the packet delivery rate in epidemic routing is considerably improved. Our simulation results show that epidemic routing with the proposed optimal buffer scheme outperforms the original epidemic routing in terms of packet delivery rate and average end-to-end delay. It is worth noting that the improved epidemic routing needs much less buffer size compared to that of the original epidemic routing for ensuring the same packet delivery rate. In particular, even though the buffer size is very small (e.g., 50), the packet delivery rate in epidemic routing with the proposed optimal buffer scheme is still 95.8%, which can satisfy general communication demand.

• Asia Marketing Journal
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• v.19 no.4
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• pp.1-14
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• 2018

Social networking service(SNS) helps users manage, share and delivery a vast information as a communication tool. When users read crisis news in SNS, they communicate the information with others by considering not only their belief (i.e., cognitive risk perception) but also emotion (i.e., affective risk perception). However, few researches have been interested in the construct of communication behaviors of crisis in SNS. This study aimed to explore the role of risk perception (cognitive and affective risk perception) between crisis responsibility and communication behavior through dual processing theory. As a result of the empirical analysis, crisis responsibility had a positive effect on cognitive risk perception and affective risk perception. In addition, cognitive risk perception had no significant effect on communication behavior whereas affective risk perception had influence on communication behavior positively. Thus, our findings may predict that the affective risk perception through crisis responsibility is more potentially important to communication behavior such as sharing information rather than cognitive risk perception. The results give insightful ideas why marketer should reduce perceived emotion caused by risk to strengthen prospective SNS users understanding of communication behavior intention.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.1
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• pp.37-48
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• 2004

Important Java network application services have been rapidly increased along with the growth of the Internet. So, it is desirable for such applications to serve transparently, continuously and safely even if the network is temporally partitioned or certain hosts running those services are crashed down. To satisfy such requirements, many group communication systems have been developed. However, existing Java-based group communication systems do not support both the extended virtual synchrony and various types of message delivery such as FIFO, causal, total and safe delivery service. In this paper, we present the design and implementation of a Java group communication system, named JACE, supporting various types of message delivery between group members and the extended virtual synchrony model. The JACE system consists of a number of protocol modules which can be stacked on top of each other in a variety of ways. In addition, using the JACE system, we have developed an experimental UDDI registry for discovering and publishing information about Web services.

• Proceedings of the Korean Society of Computer Information Conference
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• 2009.01a
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• pp.391-394
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• 2009

All-IP는 통신에 관련된 모든 개체가 IP를 사용하는 네트워크를 의미한다. All-IP 네트워크에서는 보안을 위해 통신 내용에 대한 암호화가 반드시 이루어져야 하며, 신뢰할 수 있는 3자 (trusted third party)는 서비스 중재 및 부가 서비스 제공을 위해 통신에 사용된 암호화 키를 획득할 수 있어야 한다. 이는 통신 개체가 다른 개체에게 암호화 키를 전달하는 메커니즘이 필요하다는 것을 의미한다. 우리는 본 논문을 통해, 통신 개체가 다른 개체에게 키를 전달하는 기법을 37에로 분류하고 각 기법에 대해 상세히 설명한다. 또한, 우리는 새로운 키 전달 프로토콜을 제안하고 3가지 운용 모드를 제시한다. 우리가 제안하는 프로토콜용 사용자의 필요에 따라 보안 기능을 선택적으로 운용할 수 있다. 성능평가 및 분석 결과에 따르면, 보안 가능과 성능은 뚜렷한 트레이드오프(trade-off) 관계가 있음을 알 수 있고, 기본적인 기능만을 운용할 경우 추가적인 오버헤드가 거의 없음을 알 수 있다.

• Macromolecular Research
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• v.17 no.7
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• pp.464-468
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• 2009

Gelatin nanoparticles derived from bovine or porcine have been developed as various types of drug delivery system, and they need to be cross-linked to maintain their physicochemical properties in aqueous environments. Although gelatin is a widely used material in pharmaceutical industries, the safety issue of animal-origin gelatins, such as transmissible mad cow disease and anaphylaxis, remains to be solved. The purpose of this study was to prepare type A gelatin (GA) nanoparticles by modified, two-step, desolvation method and compare the toxicity of the resulting GA nanoparticles with recombinant human gelatin (rHG) nanoparticles. The GA nanoparticles were characterized, and drug loading and release pattern were measured. FITC-BSA, a model protein, was efficiently loaded in the nanoparticles and then released in a biphasic and sustained release pattern without an initial burst. In particular, the cell viability of the GA nanoparticles was less than that of the rHG nanoparticles. This finding suggests that rHG nanoparticles should be considered as an alternative to animal-origin gelatin nanoparticles in order to minimize the safety problems.

• The Journal of the Korea Contents Association
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• v.8 no.7
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• pp.146-152
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• 2008

In the modern times, video media area is dramatically developing and growing. The motion graphic that is one of video presentation technique as an effective communication way between sender and receiver is beginning to make its appearance. The motion graphic provides the clearance of visual information to deliver it more easily and accurately and improves the effect of communication to increase the effect of image and information delivery. In this research, the writer wants to examine the production method of motion graphic to improve convenience and efficiency of communication to the better direction for production process by researching and analyzing the title design and its structure having short and significant information delivery and strong visual presentation function.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.6
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• pp.602-609
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• 2003

Emerging high-speed next-generation Internet is enabling immersive media communication systems and applications to realize geographically distributed team collaborations while overcoming the limit of distance and time. Focusing on the reliable real-time delivery of 3D (i.e., stereo) video among corresponding parties, in this paper, key schemes for stereo video processing/display and reliable transport of stereo video packets over high-speed Internet are designed and implemented. The performance of proposed stereo video delivery system is evaluated both by emulating various network situations for quantitative comparison and by transmitting over real-world Internet up to the speed of around 100 Mbps. The results demonstrate the feasibility of the proposed system in supporting the desired immersive communication.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.5
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• pp.1-10
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• 2002

This study is based on user requirements before the implementation of B2B order and delivery systems. For accurate and easy understanding of the user's requirements I have expressed my specifications in graphical method and to make use of multiple diagrams, I have used UML. In these specifications, I have implemented B2B order and delivery systems with the use of XML, with company 'N' which is domestic aluminum manufacturer as the study object. The results of this study are as follows. First, both a developer and a user can understand the problems associated with specifying study objects through this system. Second, the communication between developers and users is more effective using this system. Third programming became easier because or the formalized specifications of this system. Fourth, this system facilitates the rapid handling of marketing department and stock management. Fifth, order and reservation management became more rapid and accurate through the use of this system. Sixth, this system can help nate B2B order and delivery systems that can be direct transactions. Seventh, this system helps to reduce purchasing costs by allowing for the rapid and simple order and delivery of raw materials. Finally, this study emphasized the advertising effect of an aluminum vessel.

• Journal of Korean Library and Information Science Society
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• v.35 no.1
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• pp.377-397
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• 2004

This study investigated the use of community information and communication technologies in light of its dual visions (i.e., serving as an affordable Internet service provider and a community building tool). Surveying the randomly selected users of a community network (n = 213), this study examined the influence of the community features on service use compared to that of Internet features. The present study found that the respondents were using the service mainly for general Internet features, such as email and web access. More than two-thirds of the respondents did not recognize community contents as available service. Community features of the service were found as significant predictors of use only among people who were aware of community contents but not among people who were not. Nonetheless, there was no difference in the amount of use between the two groups, indicating that the awareness of community contents itself did not increase use. Findings suggest that the service providers did not fully communicate the community aspect of the service with the users although the very aspect distinguishes the service from other Internet services.

• Journal of Korean Library and Information Science Society
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• v.24
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• pp.45-79
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• 1996

Rising publication costs and declining financial resources have resulted in renewed interest among librarians in resource sharing. Although the idea of sharing resources is not new, there is a sense of urgency not seen in the past. Driven by rising publication costs and static and often shrinking budgets, librarians are embracing resource sharing as an idea whose time may finally have come. Resource sharing in electronic environments is creating a shift in the concept of the library as a warehouse of print-based collection to the idea of the library as the point of access to need information. Much of the library's material will be delivered in electronic form, or printed. In this new paradigm libraries can not be expected to su n.0, pport research from their own collections. These changes, along with improved communications, computerization of administrative functions, fax and digital delivery of articles, advancement of data storage technologies, are improving the procedures and means for delivering needed information to library users. In short, for resource sharing to be truly effective and efficient, however, automation and data communication are essential. The possibility of using full-text online databases as a su n.0, pplement to interlibrary loan for document delivery is examined. At this point, this article presents possibility of using full-text online databases as a means to interlibrary loan for document delivery. The findings of the study can be summarized as follows : First, turn-around time and the cost of getting a hard copy of a journal article from online full-text databases was comparable to the other document delivery services. Second, the use of full-text online databases should be considered as a method for promoting interlibrary loan services, as it is more cost-effective and labour saving. Third, for full-text databases to work as a document delivery system the databases must contain as many periodicals as possible and be loaded on as many systems as possible. Forth, to contain many scholarly research journals on full-text databases, we need guidelines to cover electronic document delivery, electronic reserves. Fifth, to be a full full-text database, more advanced information technologies are really needed.