• Proceedings of the KSR Conference
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• 2010.06a
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• pp.371-379
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• 2010

Since Kyoto Protocol to the United Nations Framework Convention on Climate Change in 2005 takes effect, the transportation policies of most countries move toward encouraging the use of the transit mode with energy efficient and low carbon. Korea is 8th country of producing Co2 emissions and will be one of obligation countries decreasing Co2 after year 2013. In order to improve the efficiency of national transport system investment, this study developed the strategies toward rail-oriented transport system by considering operational speed and accessability, rail-oriented development, and introduce of ubiquitous technique in railway. The four major strategies targeted for future year are introduced here such as One-hour rail(connecting major cities within one hour), Seamless 30(accessing major railway stations within 30 minutes, Rail urbanism (railway-based urban planning), and U-rail (railway service with ubiquitous technique). Each strategy includes several action plans and their priorities are investigated using AHP(Analytic Hierarchy Process) to organize them by time scheme as short, mid, and long term perspective.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.7
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• pp.540-544
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• 2007

Researches on Sensor Network has become much more active and is currently being applied to many different fields. However since sensor network is limited to only collecting and reporting information regarding a certain event, and requires human intervention with that given information, it is often difficult to react to an event or situation immediately and proactively. To overcome this kind of limitation, Wireless Sensor and Actor Networks (WSANs) with immediate-response Actor Nodes has been proposed which adds greater mobility and activity to exisiting sensor networks. Although WSANs shares many common grounds with sensor networks, it is difficult to apply exisiting security technologies due to the fact that WSAN contains Actor Nodes that are resource-independent and mobile. This research therefore seeks to demonstrate ways to provide security, integrity and authentication services for WSAN's secure operation, by separating networks into hierarchcial structure by each node's abilities and providing different encryption key-based secure protocols for each level of hierarchy: Pair-wise Key, Node Key, and Region Key for sensor levels, and Public Key for actor levels.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.8
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• pp.465-472
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• 2004

Proxy signatures is a signature scheme that an original signer delegates one's signature capability to a proxy signer, and then the proxy signer creates a signature on behalf of the original signer. Delegation of authority is a common practice in the real world, in particular, it happens naturally in hierarchical groups such as company, bank and army, etc. In this paper, we propose a new dynamic multi-proxy signature scheme allowing repetitive delegations in a hierarchical group. We adopt multi-proxy signatures to enhance the security of proxy signature. In multi-proxy signatures, plural proxy signers can generate a valid proxy signature collectively on behalf of one original signer. In our scheme, the proxy group is not fixed but constructed dynamically according to some situations. Delegations are processed from higher level to lower level in the hierarchy using delegation tickets. When the original signer wants to delegate one's signature authority, the original signer generates a delegation ticket based on secret sharing and Diffie-Hellman problems. The delegation ticket is shared among proxy signers and then all the proxy signers can generate a valid proxy signature collectively by reconstructing the original signer's delegation ticket. If a certain proxy signer can not attend the proxy signature generating protocol, the proxy signer can also delegate repetitively his partial signature authority to the lower level participants, and then the proxies are constructed dynamically.

• Journal of Environmental Policy
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• v.8 no.2
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• pp.83-118
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• 2009

Clean Development Mechanism(CDM) projects under the Kyoto Protocol have two objectives. One is to assist the Parties included in Annex I in achieving compliance with their quantified emission limitation and reduction commitments in cost-effective ways by allowing them to implement emission reduction projects in Non-Annex I countries and receive CERs, which will offset their reduction commitments. The other is to assist Parties not included in Annex I in achieving sustainable development and technology transfers through investments by Annex I countries. However, in reality, it is said that the former objective is achievable but the latter is not. In this light, this article suggests sustainability appraisal criteria applicable for Korea. Among various methodologies, we used the 'multi-attributes utility theory(MAUT)'; one of the 'multi-criteria analysis (MCA)' methodologies judged to be the most practical and relevant. Based on the guidelines of the MAUT methodology, we identified sustainability criteria that meet the guidelines. We took two tracks, the first to find the preferences of Korean experts, and the other to check foreign cases. In all, 37 preliminary criteria were suggested to Korean experts and each criterion was scored, from between 1 and 3, in terms of relevance, possibility of real improvement, easiness of data collection, and preferences. We combined foreign cases and the results of a survey conducted in Korea and selected 12 core criteria and 10 additional criteria. After that, all the criteria were converted into indicators. The indicators were applied to a CDM project for case study. We chose the "Sihwa Tidal Power Project", which is currently the biggest tidal power plant in the world. Twelve core indicators and 3 additional indicators were applied. In order to weight each indicator, the 'analytical hierarchy process (AHP)' was used. A total of 30 experts were asked to suggest weights and 21 answered. Among them, only 14 respondents were proven to meet the consistency ratio. We analyzed the 14 responses through Expert Choice and the CDM project was scored (+)53.082. In addition, sensitivity analysis was undertaken with the result of (+)44.667 to (+)65.522. As a result of this study, it was proven that this project would contribute to the sustainable development of Korea.