• Title/Summary/Keyword: Signed Networks

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Metered Signatures: How to Restrict the Signing Capability

  • Kim, Woo-Hwan;Yoon, Hyo-Jin;Cheon, Jung-Hee
    • Journal of Communications and Networks
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    • v.12 no.3
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    • pp.201-208
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    • 2010
  • We propose a new notion of metered signatures. Metered signature is an extension of k-times signatures in which a signer can generate only k signatures. However, the restriction of metered signatures can be more elaborate: It can be used k-times every day or to preserve the order of signed messages in some applications. Any violation of this regulation reveals a secret key or the signature on a predetermined message. The applications includes proxy signatures, limited free downloads, and the rating web site. We give two instances of metered signatures: One is based on the computational Diffie-Hellman problem (CDHP) using a bilinear map and the other is based on the RSA problem. In both schemes, the signature and certificate size and the verification cost are constant with respect to k. Further, we show that the proposed metered signatures admit batch verification of many signatures almost at one verification cost with small security loss.

The Economics of Conflict and Cooperation in the Asia-Pacific: RCEP, CPTPP and the US-China Trade War

  • Park, Cyn-Young;Petri, Peter A.;Plummer, Michael G.
    • East Asian Economic Review
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    • v.25 no.3
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    • pp.233-272
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    • 2021
  • The Regional Comprehensive Economic Partnership (RCEP) agreement, signed in November 2020, comes shortly after the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) entered into force and the US-China Trade War escalated. We use a computable general equilibrium model to assess the long-term effects of these three developments on income, trade, economic structure, factor returns and employment across the world, and especially in Asia-Pacific countries. The results suggest that RCEP could generate income gains that will be almost twice as large as those of the CPTPP, and that the two agreements together will largely offset the substantial negative effects of the US-China Trade War for the world as a whole. All three policy developments, but especially RCEP, will deepen East Asian production networks and will raise productivity and increase wages and employment in much of East Asia. At the sectoral level, regional trade in non-durable and durable manufactures will experience the most growth.

Neural network for automatic skinning weight painting using SDF (SDF를 이용한 자동 스키닝 웨이트 페인팅 신경망)

  • Hyoseok Seol;Taesoo Kwon
    • Journal of the Korea Computer Graphics Society
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    • v.29 no.4
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    • pp.17-24
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    • 2023
  • In computer graphics and computer vision research and its applications, various representations of 3D objects, such as point clouds, voxels, or triangular meshes, are used depending on the purpose. The need for animating characters using these representations is also growing. In a typical animation pipeline called skeletal animation, "skinning weight painting" is required to determine how joints influence a vertex on the character's skin. In this paper, we introduce a neural network for automatically performing skinning weight painting for characters represented in various formats. We utilize signed distance fields (SDF) to handle different representations and employ graph neural networks and multi-layer perceptrons to predict the skinning weights for a given point.

Stakeholder Networks Supplying Rural Tourism in The Mekong Delta, Vietnam: The Case of Thoi Son Islet, Tien Giang Province (메콩델타지역 농촌관광의 공급자 네트워크: 티엔장성(省) 터이선 섬을 사례로)

  • Hoang, Chau Ngoc Minh;Kim, Doo-Chul
    • Journal of the Economic Geographical Society of Korea
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    • v.16 no.3
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    • pp.423-444
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    • 2013
  • Tourism in Thoi Son Islet has been the advanced model for rural tourism in the Mekong Delta region since the 1990s. The continuously rising number of tourists, however, has also created problems that affect sustainable rural development. To understand these problems, this research analyzed how rural tourism has been operated through the methodology of a stakeholder network. After investigating the network among key stakeholders (Ho Chi Minh travel agencies (HCMTAs), local travel agencies (LTAs), and local residents, the result showed that in the current model, HCMTAs and LTAs have played the role of connectors, working as hubs to shift tourists (demand) to match local residents (supply), with the networking being dominated by signed contracts (formal networks). The networks between LTAs and local residents are both formal and informal. Inter- and intra-networks among local residents are dominated by informal networks of established working relationships based on networks of family, friends, and neighbors. Moreover, this research has found that there is no cooperating network among LTAs. Among owners of tourist sites was not also found cooperating network. The primary motivating factor for these stakeholders is price competition; this has led to a disproportionately small share of revenue for local stakeholders, with most tourism revenue going to HCMTAs. Additionally, because of the high competition among local stakeholders, this results in local stakeholders having little or no negotiating power when conducting business with HCMTAs. Meanwhile the Tien Giang Tourism Association is inefficient in fostering cooperation among local stakeholders to increase their negotiating power.

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A Threshold Ring Group Signature for Ubiquitous Electronic Commerce (유비쿼터스 전자거래를 위한 쓰레시홀드 링 그룹 서명)

  • Sung, Soon-Hwa
    • The KIPS Transactions:PartD
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    • v.14D no.4 s.114
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    • pp.373-380
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    • 2007
  • Ubiquitous electronic commerce can offer anytime, anywhere access to network and exchange convenient informations between individual and group, or between group and group. To use secure ubiquitous electronic commerce, it is essential for users to have digital signature with the properties of integrity and authentication. The digital signature for ubiquitous networks is required neither a trusted group manager, nor a setup procedure, nor a revocation procedure etc. because ubiquitous networks can construct or deconstruct groups anytime, anwhere as occasion demands. Therefore, this paper proposes a threshold ring signature as digital signature for secure ubiquitous electronic commerce using the ring signature without forgery (integrity) and the (n,t) ring signature solving the problem cannot prove the fact which a message is signed by other signer. Thus the proposed threshold ring signature is ubiquitous group signature for the next generation.

The Mobile Voting Scheme Providing Voting Fairness Assured by Candidates (후보자들에 의한 선거의 공정성을 제공하는 모바일 투표 기법)

  • Yun, Sung-Hyun
    • Journal of Digital Convergence
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    • v.10 no.2
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    • pp.161-169
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    • 2012
  • It requires a lot of costs and manpower to manage the election system. The electronic voting scheme is needed to make the election system to be economic and fair. Especially, wide spread use of smart phones and wireless networks makes the mobile voting is of major concern. In mobile voting scheme, a smart phone user can vote regardless of the places. In this paper, the mobile voting scheme is proposed where candidates can guarantee fairness of the election system. We analyze mobile voting requirements and create the mobile ID which has legal binding forces and PKI based digital signature keys. In the proposed scheme, a voter's ballot is signed by all candidates using undeniable multi-signature scheme. During the counting stage, the multi-signature on the ballot is not verified without help of all candidates.

A Study on Effect of Trans-Pacific Partnership through East Asia Trade Network (환태평양경제동반자협정이 동아시아 무역네트워크에 미치는 영향에 관한 연구)

  • Han, Neung-Ho
    • Korea Trade Review
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    • v.41 no.4
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    • pp.293-313
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    • 2016
  • In the East Asian region, the advancement of trade networks is being facilitated, which turns out that economic integration across borders is being advanced due to FTA expansion, freedom of business activity growing through the reform of regulatory system in each country, and the processing of division of labor between processes across borders. Trans-Pacific Partnership(TPP), which is a U.S. led multilateral FTA, was signed on February 4 2016 in Auckland, New Zealand by 12 countries, by which changes in the East Asia Trade Network are also expected. For this reason, this study examined the impact that TPP would have on East Asia Trade Network. According to the result of this study, it was determined that TPP, as the regulation and system which will lead globalization of the supply chain, will change Supply Chain structure and result in a positive effect on Value Chain. This will have a significant impact on the East Asian trade network, and connect to enhanced competitiveness of participating enterprises. In addition, TPP seems to be the basis for realization of FTAAP(Free Trade Area of the Asia-Pacific) in the future, Therefore, Korea who has high Degree of Dependence upon Foreign Trade will have to pay make political effort to effectively deal with this changing trading environment in East Asia.

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A Comparative Study on Government R&D Evaluation System in Selected Countries (주요국의 정부 연구개발(R&D) 평가제도에 관한 비교 연구)

  • Kim, Jong-Woon;Ha, Kyu-Soo
    • Journal of Digital Convergence
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    • v.11 no.4
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    • pp.77-90
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    • 2013
  • This study is to seek measures for streamlining the evaluation system by analyzing the examples of advanced countries. This study was conducted, based on the relevant government policy documents and previous research papers, in the manner of comparing and analyzing the issues and cases regarding the government evaluation system of public-funded R&D programs in selected countries. In Korea, a national R&D performance evaluation system was introduced by law in 2006. In United States, Obama government has enhanced government performance management by signed into law the GPRA Modernezation Act of 2010. The Japanese Government issued a newly revised Guideline on National R&D Evaluation in late 2012. European Union has also been constantly updating its evaluation system for Framework Programmes(FPs) begun since 1984. This study gets some insights from the recent development of R&D evaluation in the other countries. It is important for the government R&D evaluation system to be in line with national S&T policy and agency's mission. In micro views, specific evaluation approaches and methods by types of various R&D programs should be more illustratively developed. Additionally it is suggested to monitor recent trends and techniques on R&D evaluation by participating in activities to communicate and share their knowledge and experiences in international evaluation research networks.

A Real-Time Messaging System for Twitter Users and Their Followers (트위터 사용자와 팔로워들 간의 실시간 메시지 교류 시스템 개발)

  • Park, Jong-Eun;Kwon, O-Jin;Lee, Hong-Chang;Lee, Myung-Joon
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.9
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    • pp.87-95
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    • 2011
  • Recently, as smartphones have rapidly come into wide use and various social networking services have grown, people perform a variety of interactions through the virtual and real world based on them. Usually, such services focus on easy formation of social links among users, supporting the exchange of simple messages among users on the networks. Twitter, one of such services used worldwide, supports short message service named Tweet and has over 200 million members signed up. n this paper, we propose techniques for supporting real-time group messaging based on the social network of Twitter and describe a smartphone group messaging system developed with the techniques. The system automatically forms a group that include a Twitter user and the followers of the user, supporting real-time group messaging among the group members. The developed system is composed of an XMPP protocol-based messaging server and smartphone client applications which perform real-time messaging based on the social network of Twitter. Twitter users can easily use the system utilizing Tweet messages, exchanging real-time messages with their followers within the groups instantly established on the XMPP server.

The Current Status of the Warsaw Convention and Subsequent Protocols in Leading Asian Countries (아시아 주요국가(主要國家)들에 있어서의 바르샤바 체제(體制)의 적용실태(適用實態)와 전망(展望))

  • Lee, Tae-Hee
    • The Korean Journal of Air & Space Law and Policy
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    • v.1
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    • pp.147-162
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    • 1989
  • The current status of the application and interpretation of the Warsaw Convention and its subsequent Protocols in Asian countries is in its fredgling stages compared to the developed countries of Europe and North America, and there is thus little published information about the various Asian governments' treatment and courts' views of the Warsaw System. Due to that limitation, the accent of this paper will be on Korea and Japan. As one will be aware, the so-called 'Warsaw System' is made up of the Warsaw Convention of 1929, the Hague Protocol of 1955, the Guadalajara Convention of 1961, the Guatemala City Protocol of 1971 and the Montreal Additional Protocols Nos. 1,2,3 and 4 of 1975. Among these instruments, most of the countries in Asia are parties to both the Warsaw Convention and the Hague Protocol. However, the Republic of Korea and Mongolia are parties only to the Hague Protocol, while Burma, Indonesia and Sri Lanka are parties only to the Warsaw Convention. Thailand and Taiwan are not parties only to the convention or protocol. Among Asian states, Indonesia, the Phillipines and Pakistan are also parties to the Guadalajara Convention, but no country in Asia has signed the Guatemala City Protocol of 1971 or the Montreal Additional Protocols, which Protocols have not yet been put into force. The People's Republic of China has declared that the Warsaw Convention shall apply to the entire Chinese territory, including Taiwan. 'The application of the Warsaw Convention to one-way air carriage between a state which is a party only to the Warsaw Convention and a state which is a party only to the Hague Protocol' is of particular importance in Korea as it is a signatory only to the Hague Protocol, but it is involved in a great deal of air transportation to and from the united states, which in turn is a party only to the Warsaw Convention. The opinion of the Supreme Court of Korea appears to be, that parties to the Warsaw Convention were intended to be parties to the Hague Protocol, whether they actually signed it or not. The effect of this decision is that in Korea the United States and Korea will be considered by the courts to be in a treaty relationship, though neither State is a signatory to the same instrument as the other State. The first wrongful death claim in Korea related to international carriage by air under the Convention was made in Hyun-Mo Bang, et al v. Korean Air Lines Co., Ltd. case. In this case, the plaintiffs claimed for damages based upon breach of contract as well as upon tort under the Korean Civil Code. The issue in the case was whether the time limitation provisions of the Convention should be applicable to a claim based in tort as well as to a claim based in contract. The Appellate Court ruled on 29 August 1983 that 'however founded' in Article 24(1) of the Convention should be construed to mean that the Convention should be applicable to the claim regardless of whether the cause of action was based in tort or breach of contract, and that the plaintiffs' rights to damages had therefore extinguished because of the time limitation as set forth in Article 29(1) of the Convention. The difficult and often debated question of what exactly is meant by the words 'such default equivalent to wilful misconduct' in Article 25(1) of the Warsaw Convention, has also been litigated. The Supreme Court of Japan dealt with this issue in the Suzuki Shinjuten Co. v. Northwest Airlines Inc. case. The Supreme Court upheld the Appellate Court's ruling, and decided that 'such default equivalent to wilful misconduct' under Article 25(1) of the Convention was within the meaning of 'gross negligence' under the Japanese Commercial Code. The issue of the convention of the 'franc' into national currencies as provided in Article 22 of the Warsaw Convention as amended by the Hague Protocol has been raised in a court case in Korea, which is now before the District Court of Seoul. In this case, the plaintiff argues that the gold franc equivalent must be converted in Korean Won in accordance with the free market price of gold in Korea, as Korea has not enacted any law, order or regulation prescribing the proper method of calculating the equivalent in its national currency. while it is unclear if the court will accept this position, the last official price of gold of the United States as in the famous Franklin Mint case, Special Drawing Right(SDR) or the current French franc, Korean Air Lines has argued in favor of the last official price of gold of the United States by which the air lines converted such francs into us Dollars in their General Conditions of Carriage. It is my understanding that in India, an appellate court adopted the free market price valuation. There is a report as well saying that if a lawsuit concerning this issue were brought in Pakistan, the free market cost of gold would be applied there too. Speaking specifically about the future of the Warsaw System in Asia though I have been informed that Thailand is actively considering acceding to the Warsaw Convention, the attitudes of most Asian countries' governments towards the Warsaw System are still wnot ell known. There is little evidence that Asian countries are moving to deal concretely with the conversion of the franc into their own local currencies. So too it cannot be said that they are on the move to adhere to the Montreal Additional Protocols Nos. 3 & 4 which attempt to basically solve many of the current problems with the Warsaw System, by adopting the SDR as the unit of currency, by establishing the carrier's absolute liability and an unbreakable limit and by increasing the carrier's passenger limit of liability to SDR 100,000, as well as permiting the domestic introduction of supplemental compensation. To summarize my own sentiments regarding the future, I would say that given the fact that Asian air lines are now world leaders both in overall size and rate of growth, and the fact that both Asian individuals and governments are becoming more and more reliant on the global civil aviation networks as their economies become ever stronger, I am hopeful that Asian nations will henceforth play a bigger role in ensuring the orderly and hasty development of a workable unified system of rules governing international commercial air carriage.

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