• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.93-100
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• 2012

In this paper we have proposed a linear time algorithm for solving the minimum sharable-bandwidth tree construction problem. The public-shared network is a user generated infrastructure on which a user can access the Internet and transfer data from any place via access points with sharable bandwidth. Recently, the idea of constructing the SVC video streaming delivery system on public-shared network has been proposed. To send video stream from the stream server to clients on public-shared network, a tree structure is constructed. The problem of constructing a tree structure to serve the video streaming requests by using minimum amount of sharable bandwidth has been shown to be NP-hard. The previously published algorithms for solving this problem are either unable to find solutions frequently or less efficient. The experimental results showed that our algorithm is excellent both in the success rate of finding solutions and in the quality of solutions.

• Journal of the Korea Society of Computer and Information
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• v.20 no.4
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• pp.87-93
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• 2015

Recently, an idea has been suggested in which members construct the network by sharing their surplus bandwidth of their own access point. This kind of network is called public-shared network. As an application, SVC video streaming delivery system on public-shared network has been proposed. To send video stream from the stream server to clients, a tree structure is constructed where the root is a stream server, internal nodes are sharable access points, and leafs are clients. The previous researches have focused on constructing the minimal sharable-bandwidth tree which can serve all video streaming requests using the minimal sharable bandwidth. In this paper, we have shown that the problem of constructing a tree structure with given sharable access points to serve maximal video streaming requests is NP-hard. We also have developed an efficient heuristic algorithm for this problem and evaluated experimentally our algorithm.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.5
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• pp.109-119
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• 2004

The home network environment can be defined as a network environment, connecting digital home devices such as computer systems, digital appliances, and mobile devices. In this kind of home network environments, there will be numerous local/remote interactions to monitor and control the home network devices and the home gateway. Such an environment may result in communication bottleneck. By applying the mobile agents that can migrate among the computing devices autonomously and work on behalf of the user, remote interactions and network traffics can be reduced enormously. The mobile agent authentication is necessary to apply mobile agent concept to the home network environments, as a prerequisite technology for authorization or access control to the home network devices and resources. The existing mobile agent systems have mainly used the public key based authentication scheme, which is not suitable to the home network environments, composed of digital devices of limited computation capability. In this paper, we propose a shared key based mobile agent authentication scheme for single home domain and expand the scheme to multiple domain environments with the public key based authentication scheme. Application of the shared key encryption scheme to the single domain mobile agent authentication enables to authenticate the mobile agent with less overhead than the public key based authentication scheme.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.2
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• pp.157-171
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• 2014

A organization of social enterprises is to achieve various goals such as private interests, the public nature, and social policy. For fulfilling these goals, we have to understand the various success factors. These success factors were shared among peoples. This study explored a position of structure of social network formed by success factors of Social Enterprises with importance. A position within social network defined a number of link connected other nodes. A position is closely associated with to individual's behaviors, opinions and thinking. We used social network analysis with two mode method for explaining feathers of structure of social network formed by success factors shared among peoples. We choose degree centrality for determining a position within social network. Centrality is a key measure in social network analysis. Results is that shared success factors are operation capital(15.15%) totally, and by Buying experience of products of Social Enterprises, Business Compliance(14.39%) and planning(12.88%), and by usage time of smart devices, Business Support(17.05%) and planning(16.10%). and the dominant success factor was not explored.

• Korean Journal of Health Education and Promotion
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• v.33 no.3
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• pp.1-11
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• 2016

Objectives: The challenging issue of public health program is to strengthen partnership and network between health resources. This study identified the structure and characteristics of school health program network. Methods: In this paper we collected data from schools and organizations in 4 local communities in 2014 that participated to school health program. Using social network analysis techniques we measured the number of component, diameter, density, average degree, node centralization for each network. Results: We determined that networks shared some common organizational structure such as less density, low average degree, and short diameter. Networks were dominated by the health center, and directions of collaborations between nodes were mostly one-way. Conclusions: These findings can help to depict the network of school health program. The further research is necessary to define causal relationship between network effectiveness and public health outcomes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.823-832
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• 1997

As enterprises use ATM networks for their private networks and as these private networks use public ATM networks for wide area communication, the need for the customers to be able to manage both private and public networks. Currently, some standardization work is being done towards providing this capability to customers. In this paper, we propose a new customer network management (CNM) system architecture for the management of both ATM a private network and a public network in a uniform way. The particular features of the proposed architecture lies in the efficient support of the complex hierarchial TMN manager-agent relationships at M3 and M4 interfaces, and the support of SNMP and CMIP integration which is necessary for the implementation of a CNM system. The TMN hierarchical many-to-many manager-agent relationships are realized by the utilization of CORBA-Based SMK (Shared Management Knowledge) implementation. We have also implemented the prototype of a ATM CNM system, and measures the performance for the demonstration of the suitability of the proposed architecture.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.9
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• pp.1051-1056
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• 2014

Social Network Services are widely used by mass population and it is used as an important communications tool because it allows distribution of diverse and abundant amount of information. This thesis proposes to add a new valuable service function in social network for mobile-based civil complaint management. Therefore, we will develop a social network application for civil affair services that allows immediate civil compliant management while being able to share the contents related to civil affairs with other people. As a result of the experiment, the effect and efficiency of the method proposed in this thesis for social network-based civil affair services was proven. Hence, the social network for mobile-based civil affair services always provides new and improved service components. Moreover, discussing civil complaints in a social network point of view, we can expect high ripple effect and encourage more participation of public users dealing with civil affairs.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.11
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• pp.35-44
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• 2005

In Mobile IP protocol, because a mobile node still uses its home IP address even though it moves to foreign network from home network, authentication among mobile node, foreign network and home network is critical issue. Many researches about this issue have been based on shared secret, for example mobile node and home agent authenticate each other with pre-shared symmetry key. And they missed several security issues such as replay attack. Although public key scheme could be applied to this issue easily, since the public key cryptography is computationally complicated, it still has the problem that it is not practical to realistic environment. In this paper, we describe several security issues in Mobile IP protocol. And we propose new Mobile IP authentication protocol that is applicable to realistic environment using public key algorithm based on certificate. It has scalability for mobile nodes and is applicable to the original Mobile IP protocol without any change. Finally we prove security of the proposed protocol and that it might not affect performance of the original Mobile IP protocol.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.47-47
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• 2000

Most measuring devices are equipped with RS-232 or GPIB interface for communicating data with computers. If the measuring devices can be accessed by a server computer, the valuable information from the devices can be effectively shared with other computers via internet. But, if the measuring devices and the server computer are too far away, it is difficulty to directly connect them by RS232 interface. PSTN(Public Switched Telephone Network) refers to the world's collection of interconnected voice-oriented public telephone networks. Measuring computer system which is equipped with RS232 interface and modem for PSTN can be introduced to overcome the aforementioned distance problem, In this work, an internet based remote monitoring system which utilizes PSTN and VRML for 3-dimensional GUI is proposed.

• Journal of Public Diplomacy
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• v.1 no.2
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• pp.49-74
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• 2021

In this paper, I applied grounded theory in exploring how Twitter became the battlefield for China's public diplomacy campaign. China's new move to global social media platforms, such as Twitter and Facebook, has been a controversial strategy in public diplomacy. This study analyzes Chinese Foreign Spokesperson Zhao Lijian's Twitter posts and comments. It models China's recent diplomatic move to Twitter as a "war of words" model, with features including "leadership," "polarization," and "aggression," while exerting possible effects as "resistance," "hatred," and "sarcasm" to the global community. Our findings show that by failing to gage public opinion and promote the country's positive image, China's current digital diplomacy strategy reflected by Zhao Lijian's tweets has instead constructed a polarized political public sphere, contradictory to the country's promoted "shared human destiny." The "war of words" model extends our understanding of China's new digital diplomacy move as a hybrid of state propaganda and self-performance. Such a strategy could spread hate speech and accelerate political polarization in cyberspace, despite improvements to China's homogenous network building on Twitter.