• Title/Summary/Keyword: key-agreement

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Effective Key Agreement Protocol on Zig-Bee Network (ZigBee 네트워크에서 효율적인 키 분배 프로토콜)

  • Han, Jae-Hong;Kim, Sang-Jin;Oh, Hee-Kuck
    • Proceedings of the Korea Information Processing Society Conference
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    • 2007.05a
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    • pp.993-996
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    • 2007
  • LR-WPAN의 대표적인 기술인 ZigBee는 저속 전송속도를 갖는 홈오토메이션 및 데이터 네트워크를 위해 IEEE 802.15.4 표준을 기반으로 상위 프로토콜과 응용을 규격화한 기술이다. 특히 개방된 무선 환경인 ZigBee 네트워크에서는 무엇보다 보안의 중요성이 대두되고 있으며, ZigBee Alliance 규격에도보안 계층이 포함되어 있다. 그러나 암호화에 사용되는 링크키를 생성하기 위해 신뢰성 있는 정보(마스터키)를 평문으로 전송하기 때문에 직접적으로 노출되는 위험성과 방문자 위치 추적 등 디바이스의 이동이 빈번한 환경에서 PAN 코디네이터의 과부하가 발생할 수 있는 등의 여러 가지 문제점이 존재하고 있다. 본 논문에서는 Du 등이 제안한 사전 키 분배 기법을 이용하여 ZigBee 네트워크에서의 효율적인 키 분배 프로토콜을 제안하였다. 제안된 프로토콜은 디바이스에게 임의의 행렬 열과 행 값을 송신하여 링크키를 생성함으로서 이전의 문제점을 해결하고 더욱 빠른 통신이 가능하도록 하였다.

Password-Based Authentication Protocol for Remote Access using Public Key Cryptography (공개키 암호 기법을 이용한 패스워드 기반의 원거리 사용자 인증 프로토콜)

  • 최은정;김찬오;송주석
    • Journal of KIISE:Information Networking
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    • v.30 no.1
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    • pp.75-81
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    • 2003
  • User authentication, including confidentiality, integrity over untrusted networks, is an important part of security for systems that allow remote access. Using human-memorable Password for remote user authentication is not easy due to the low entropy of the password, which constrained by the memory of the user. This paper presents a new password authentication and key agreement protocol suitable for authenticating users and exchanging keys over an insecure channel. The new protocol resists the dictionary attack and offers perfect forward secrecy, which means that revealing the password to an attacher does not help him obtain the session keys of past sessions against future compromises. Additionally user passwords are stored in a form that is not plaintext-equivalent to the password itself, so an attacker who captures the password database cannot use it directly to compromise security and gain immediate access to the server. It does not have to resort to a PKI or trusted third party such as a key server or arbitrator So no keys and certificates stored on the users computer. Further desirable properties are to minimize setup time by keeping the number of flows and the computation time. This is very useful in application which secure password authentication is required such as home banking through web, SSL, SET, IPSEC, telnet, ftp, and user mobile situation.

A Study on the utilization plan of Mutual Recognition Agreement for Korea-China FTA: Focused on TBT and Conformity Assessment (한중 FTA체결에 따른 정부의 MRA 활용 방안에 관한 연구 -TBT 및 적합성평가를 중심으로-)

  • Jun, Byoung Ho;Kang, Byung Goo
    • International Commerce and Information Review
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    • v.17 no.3
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    • pp.177-201
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    • 2015
  • Korea-China FTA was initialized in 2015. Korea has a high level of dependence on trade for its economic growth, especially to China. Technical Barriers to Trade(TBT) among various non-tariff barriers is becoming increasingly important. Elimination of TBT is one of the key issues in which the South Korean government is interested since technical barriers significantly affect trade between the two countries. MRA has been considered as an effective tool to relieve such technical barriers. Several studies and surveys showed that MRA would mitigate the barriers of import and solve the problems that many companies face in international market. This study tries to seek utilization plan of MRA for Korea-China FTA. It suggests suitable utilization plan of MRA considering the difference of technical regulations between two countries. This paper has value in that it provides specific MRA strategies targeting China while other prior studies have merely analyzed the necessity of MRA.

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Numerical Simulation of High-Velocity Oblique Impact of Mild Steel Spheres Against Mild Steel Plates (연강 판재에 대한 연강 구의 고속경사충돌 수치해석)

  • Yu, Yo-Han;Jang, Sun-Nam;Jeong, Dong-Taek
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.3
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    • pp.576-585
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    • 2002
  • A three-dimensional Lagrangian explicit time-integration finite element code for analyzing the dynamic impact phenomena was developed. It uses four node tetrahedral elements. In order to consider the effects of strain rate hardening, strain hardening and thermal softening, which are frequently observed in high-velocity deformation phenomena, Johnson-Cook model is used as constitutive model. For more accurate and robust contact force computation, the defense node contact algorithm was adopted and implemented. In order to evaluate the performance of the newly developed three-dimensional hydrocode NET3D, numerical simulations of the oblique impact of mild steel plate by mild steel sphere were carried out. Ballistic limit about various oblique angle between 0 degree and 80 degree was estimated through a series of simulations with different initial velocities of sphere. Element eroding by equivalent plastic strain was applied to mild steel spheres and targets. Ballistic limits and fracture characteristics obtained from simulation were compared with experimental results conducted by Finnegan et al. From numerical studies, the following conclusions were reached. (1) Simulations could successfully reproduce the key features observed in experiment such as tensile failure termed "disking"at normal impacts and outwards bending of partially formed plus segments termed "hinge-mode"at oblique impacts. (2) Simulation results fur 60 degrees oblique impact at 0.70 km/s and 0.91 km/s were compared with experimental results and Eulerian hydrocode CTH simulation results. The Lagrangian code NET3D is superior to Eulerian code CTH in the computational accuracy. Agreement with the experimentally obtained final deformed cross-sections of the projectile is excellent. (3) Agreement with the experimental ballistic limit data, particularly at the high-obliquity impacts, is reasonably good. (4) The simulation result is not very sensitive to eroding condition but slightly influenced by friction coefficient.

High-Speed Korean Address Searching System for Efficient Delivery Point Code Generation (효율적인 순로코드 발생을 위한 고속 한글 주소검색 시스템 개발)

  • Kim, Gyeong-Hwan;Lee, Seok-Goo;Shin, Mi-Young;Nam, Yun-Seok
    • The KIPS Transactions:PartD
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    • v.8D no.3
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    • pp.273-284
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    • 2001
  • A systematic approach for interpreting Korean addresses based on postal code is presented in this paper. The implementation is focused on producing the final delivery point code from various types of address recognized. There are two stages in the address interpretation : 1) agreement verification between the recognized postal code and upper part of the address and 2) analysis of lower part of the address. In the agreement verification procedure, the recognized postal code is used as the key to the address dictionary and each of the retrieved addresses is compared with the words in the recognized address. As the result, the boundary between the upper part and the lower part is located. The confusion matrix, which is introduced to correct possible mis-recognized characters, is applied to improve the performance of the process. In the procedure for interpreting the lower part address, a delivery code is assigned using the house number and/or the building name. Several rules for the interpretation have been developed based on the real addresses collected. Experiments have been performed to evaluate the proposed approach using addresses collected from Kwangju and Pusan areas.

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Characteristics of Post 2020 Architect and Application of Differentiation in the Post 2020 Regime (신기후체제 설계의 특징과 신기후체제에서 차별화 적용 방안)

  • Lee, Sangyun;Choi, Dohyun
    • Journal of Environmental Policy
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    • v.14 no.3
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    • pp.95-118
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    • 2015
  • The 2015 Agreement, an initial architect of the Post-2020 Regime, is expected to be adopted at the twenty-first session of the Conference of Parties to be held in Paris in 2015. We discussed key characteristics of the Post-2020 Regime and applications of differentiation which is most contentious issue in the Post-2020 negotiation. In the Post-2020 Regime, automatic ambition increases of Parties could be accomplished through applications of the circular nature of Intented Nationally Determined Contributions (INDC) as well as the progression of mitigation efforts. In terms of differentiation, it would be better to advocate a new method to applying differentiation in the Post-2020 Regime taking into account our own national circumstances. Specifically, promotion of self-differentiation which fits nearly with the philosophy of INDC could be an alternative. In order to promote self-differentiation, rules to apply self-differentiation needs to be devised, and the purpose of such rules should be the ambition increase.

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Causes and implications of increased export of frozen dumplings

  • Hye-Jung Kang;Seyoon Oh;Chanho Sohn;Hanpil Moon
    • Korean Journal of Agricultural Science
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    • v.50 no.3
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    • pp.539-549
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    • 2023
  • Domestic processed food exports might increase due to the free trade agreement (FTA) and spread of the Korean Wave, Hallyu. However, the share of the domestic raw materials in the domestic processed food industry is very low at 31.4%, which limits the spillover effect on domestic agriculture. Therefore, we selected frozen dumplings as a representative processed food whose exports are growing rapidly and conducted a multiple regression analysis to examine the effects of Hallyu and FTA variables on the frozen dumpling exports. We tried to link them to an increase in agricultural income through the expansion of demand for the domestic raw materials. This study analyzed tariff indicator as the FTA variable, cosmetics export value indicator as the Hallyu Wave variable, and other variables expected to change the trade environment such as gross domestic product (GDP) and the relative exchange rate by country as the key explanatory variables that affect changes in the trade environment. The analysis showed that the core hypothesis, the Hallyu variable and the FTA variable, have a positive impact on frozen dumpling exports. Frozen dumpling exports are expected to increase as the FTAs and the spread of Hallyu are expected to continue for the foreseeable future. Therefore, we should seek ways to increase the proportion of domestically produced ingredients in the frozen dumplings to spread the economic impact to domestic agriculture. We reviewed previous studies and determined, the price-related factors play a major role in the use of imported ingredients, and that price stability and competitiveness are essential to increase the share of the domestically produced ingredients. Based on these conclusions, we reviewed the current status of food industry-related policies and determined measures needed to expand the use of domestically produced ingredients.

A Case Study on the Limitations of the Choice of Law caused by Internationally Mandatory Rules in Entering into the Turn-Key Contracts (턴키계약체결시 국제적 강행규정에 의한 준거법 제한에 관한 사례연구 - Clough Engineering Ltd v Oil & Natural Gas Corp Ltd 사건을 중심으로 -)

  • Oh, Won-Suk;Kim, Yong-Il
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.54
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    • pp.145-166
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    • 2012
  • This article examines the limitations of the choice of law caused by Internationally Mandatory Rules in Entering into the Turn-Key Contracts. In June 2007, Clough Engineering, a corporation based in Western Australia, approached the Federal Court of Australia seeking injunctive relief and leave to commence proceedings against an entity located outside Australia, the Oil & Natural Gas Corp of India (ONGC). Clough had contracted with ONGC to provide a range of services in relation to the construction of gas and oil wells off the coast of India. The contract was governed by Indian law, and included a clause by which the parties agreed to submit their disputes to arbitration. Yet the Federal Court assumed jurisdiction over the dispute, principally because Clough had framed its claim as a plea for relief for contraventions of Australia's Trade Practices Act 1974. The result of this cases that it is possible for an arbitral tribunal to hear a claim made under the Trade Practices Act even if that claim arises "in connection with"a contract the proper law of which is not the law of Australia. However, in Transfield Philippines Inc v Pacific Hydro Ltd, the turnkey contract included a choice of law provision, selecting the law of the Philippines, and a clause providing that all disputes arising out of or in connection with the agreement were to be arbitrated under the ICC Rules, with the seat in Singapore. Hearings were in fact conducted in Melbourne, Australia, although all awards were published in Singapore. The result of this cases that it would not be appropriate for an Australian court to adjudicate claims for misrepresentation under Australian statutes dealing with misleading and deceptive conduct, once the arbitral tribunal had determined, applying appropriate choice of law rules, that such claims are governed by the law of the Philippines. To do so would lead to a multiplicity of proceedings, usurp the jurisdiction of the tribunal and deny the intention of the parties as expressed by them in the arbitration agreement. In short, the Internationally Mandatory Rules as an active part of public order create limitation of party autonomy in choice of law rules in a different way. The court is fully entitled to refuse to use those rules of law applicable on the contract which are in the contradiction to the internationally mandatory rules of law of the forum. And the court may give an effect to those Internationally Mandatory Rules that form a part of a law of foreign country when deciding about applicability of certain rules of applicable law.

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Ginsenoside (20S)Rg3 Ameliorates Synaptic and Memory Deficits in an Animal Model of Alzheimer's Disease

  • Kim, Tae-Wan
    • 한국약용작물학회:학술대회논문집
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    • 2011.09a
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    • pp.31-45
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    • 2011
  • The amyloid ${\beta}$-peptide ($A{\beta}$), which originates from the proteolytic cleavage of amyloid precursor protein (APP), plays a central role in the pathogenesis of Alzheimer's disease (AD). Mounting evidence indicates that different species of $A{\beta}$, such as $A{\beta}$ oligomers and fibrils, may contribute to AD pathogenesis via distinct mechanisms at different stages of the disease. Importantly, elevation and accumulation of soluble $A{\beta}$ oligomers closely correlate with cognitive decline and/or disease progression in animal models of AD. In agreement with these studies, oligomers of $A{\beta}$ have been shown to directly affect synaptic plasticity, a neuronal process that is known to be essential for memory formation. Our previous studies showed that $A{\beta}$ induces the breakdown of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), a phospholipid that regulates key aspects of neuronal function. PI(4,5)P2 breakdown was found to be a key step toward synaptic and memory dysfunction in a mouse model of AD. To this end, we seek to identify small molecules that could elevate the levels of PI(4,5)P2 and subsequently block $A{\beta}$ oligomer-induced breakdown of PI(4,5)P2 and synaptic dysfunction.. We found that (20S)Rg3, an active triterpene glycoside from heat-processed ginseng, serves as an agonist for phosphatidylinositol 4-kinase IIalpha (PI4KIIalpha), which is a lipid kinase that mediates a rate-limiting step in PI(4,5)P2 synthesis. Consequently, (20S)Rg3 stimulates PI(4,5)P2 synthesis by directly stimulating the activity of PI4KIIalpha. Interestingly, treatment of a mouse model of AD with (20S)Rg3 leads to reversal of memory deficits. Our data suggest that the PI(4,5)P2-promoting effects of (20S)Rg3 may help mitigate the cognitive symptoms associated with AD.

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Galloping of steepled main cables in long-span suspension bridges during construction

  • An, Yonghui;Wang, Chaoqun;Li, Shengli;Wang, Dongwei
    • Wind and Structures
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    • v.23 no.6
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    • pp.595-613
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    • 2016
  • Large amplitude oscillation of steepled main cables usually presents during construction of a long-span bridge. To study this phenomenon, six typical main cables with different cross sections during construction are investigated. Two main foci have been conducted. Firstly, aerodynamic coefficients of a main cable are obtained and compared through simulation and wind tunnel test: (1) to ensure the simulation accuracy, influences of the numerical model's grid size, and the jaggy edges of main cable's cross section on main cable's aerodynamic coefficients are investigated; (2) aerodynamic coefficients of main cables at different wind attack angles are obtained based on the wind tunnel test in which the experimental model is made by rigid plastic using the 3D Printing Technology; (3) then numerical results are compared with wind tunnel test results, and they are in good agreement. Secondly, aerodynamic coefficients of the six main cables at different wind attack angles are obtained through numerical simulation. Then Den Hartog criterion is used to analyze the transverse galloping of main cables during construction. Results show all the six main cables may undergo galloping, which may be an important reason for the large amplitude oscillation of steepled main cables during construction. The flow structures around the main cables indicate that the characteristic of the airflow trajectory over a steepled main cable may play an important role in the galloping generation. Engineers should take some effective measures to control this harmful phenomenon due to the big possibility of the onset of galloping during the construction period.