• 한국광학회:학술대회논문집
• /
• 한국광학회 1999년도 제16회 광학 및 양자전자 학술발표회Proceedings of 16th Optics and Quantum Electronics Conference, 1999
• /
• pp.6-7
• /
• 1999

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제7권11호
• /
• pp.2769-2792
• /
• 2013

In this paper, we propose an authenticated key agreement scheme, TinyIBAK, based on the identity-based cryptography and bilinear paring, for large scale sensor networks. We prove the security of our proposal in the random oracle model. According to the formal security validation using AVISPA, the proposed scheme is strongly secure against the passive and active attacks, such as replay, man-in-the middle and node compromise attacks, etc. We implemented our proposal for TinyOS-2.1, analyzed the memory occupation, and evaluated the time and energy performance on the MICAz motes using the Avrora toolkits. Moreover, we deployed our proposal within the TOSSIM simulation framework, and investigated the effect of node density on the performance of our scheme. Experimental results indicate that our proposal consumes an acceptable amount of resources, and is feasible for infrequent key distribution and rekeying in large scale sensor networks. Compared with other ID-based key agreement approaches, TinyIBAK is much more efficient or comparable in performance but provides rekeying. Compared with the traditional key pre-distribution schemes, TinyIBAK achieves significant improvements in terms of security strength, key connectivity, scalability, communication and storage overhead, and enables efficient secure rekeying.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제2권1호
• /
• pp.5-21
• /
• 2008

In order to securely transmit multicast data packets in a mobile environment where frequent join/leave events are a characteristic of the environment, there is a need for a new secure and efficient group key management solution. We propose a secure group key generation/distribution solution providing scalability and reliability. Using this solution, when a mobile node, which is in a multicast session, enters a new domain, the agent of the domain joins the multicast session and coordinates its data packets with the mobile node. The agent encrypts and transmits subsequent data packets to the mobile node, using a local one-time pad key. This key is generated with FI sequences, enabling the mobile node to regenerate the same data packet, based on the information sent by the agent. Our performance analysis demonstrates that the proposed solution can significantly reduce the number of key generations and distributions, when it is applied to the hierarchical mobile IPv6 network.

• 유통과학연구
• /
• 제14권9호
• /
• pp.15-24
• /
• 2016

Purpose - Key account management is a supplier company initiated relational approach that has received great attention from both academics and practitioners manifested in the business-to-business relationship literatures. However, there is widespread debate and contention on what should be the underlying theoretical base for defining this vital part of relationship marketing. With the insights from the social exchange theory, present paper explores how social exchange affects the dynamic nature of key account management relationship at the organizational level. Research design, data, and methodology - The paper follows a comprehensive review approach to examine the relationship between social exchange theory and key account management approach. Conceptual arguments and findings are assessed across studies with the main objective of showing how social exchange theory develops the governance mechanism in maintaining the key account relationship. Results - Since relational norm is considered as a glue for the maintenance of buyer-seller relationship in social exchange theory, factors develop the non-contractual governance mechanism 'relationship' in business-to-business relationship and this norm replaces or supplements more formal governance mechanisms such as contracts are explored. Conclusions - This paper advances central relational norm to manage the company's most important key customers and demonstrates how this norm can be developed in buyer-seller key account relationship. Implications from this new perspective are forwarded.

• Earthquakes and Structures
• /
• 제16권6호
• /
• pp.679-690
• /
• 2019

This paper presents machine learning methods using Support Vector Machine (SVM) and Multilayer Perceptron (MLP) to analyze optimal damper distribution for structural vibration control. Regarding different building structures, a genetic algorithm based optimization method is used to determine optimal damper distributions that are further used as training samples. The structural features, the objective function, the number of dampers, etc. are used as input features, and the distribution of dampers is taken as an output result. In the case of a few number of damper distributions, multi-class prediction can be performed using SVM and MLP respectively. Moreover, MLP can be used for regression prediction in the case where the distribution scheme is uncountable. After suitable post-processing, good results can be obtained. Numerical results show that the proposed method can obtain the optimized damper distributions for different structures under different objective functions, which achieves better control effect than the traditional uniform distribution and greatly improves the optimization efficiency.

• Geomechanics and Engineering
• /
• 제25권2호
• /
• pp.135-142
• /
• 2021

This study provided a new research perspective for processing and analyzing AE data to evaluate rock failure. Cluster method and information entropy theory were introduced to investigate temporal and spatial correlation of acoustic emission (AE) events during the rock failure process. Laboratory experiments of granite subjected to compression were carried out, accompanied by real-time acoustic emission monitoring. The cumulative length and dip angle curves of single links were fitted by different distribution models and distribution functions of link length and directionality were determined. Spatial scale and directionality of AE event distribution, which are characterized by two parameters, i.e., spatial correlation length and spatial correlation directionality, were studied with the normalized applied stress. The entropies of link length and link directionality were also discussed. The results show that the distribution of accumulative link length and directionality obeys Weibull distribution. Spatial correlation length shows an upward trend preceding rock failure, while there are no remarkable upward or downward trends in spatial correlation directionality. There are obvious downward trends in entropies of link length and directionality. This research could enrich mathematical methods for processing AE data and facilitate the early-warning of rock failure-related geological disasters.

• Wind and Structures
• /
• 제33권6호
• /
• pp.423-435
• /
• 2021

Although existing algorithms can predict wind speed using historical observation data, for engineering feasibility, most use moment methods and probability density functions to estimate fitted parameters. However, extreme wind speed prediction accuracy for long-term return periods is not always dependent on how the optimized frequency distribution curves are obtained; long-term return periods emphasize general distribution effects rather than marginal distributions, which are closely related to potential extreme values. Moreover, there are different wind speed parent sample types; how to theoretically select the proper extreme value distribution is uncertain. The influence of different sampling time intervals has not been evaluated in the fitting process. To overcome these shortcomings, updated steps are introduced, involving parameter sensitivity analysis for different sampling time intervals. The extreme value prediction accuracy of unknown parent samples is also discussed. Probability analysis of mean wind is combined with estimation of the probability plot correlation coefficient and the maximum likelihood method; an iterative estimation algorithm is proposed. With the updated steps and comparison using a Monte Carlo simulation, a fitting policy suitable for different parent distributions is proposed; its feasibility is demonstrated in extreme wind speed evaluations at Longhua and Chuansha meteorological stations in Shanghai, China.

• 유통과학연구
• /
• 제20권8호
• /
• pp.59-67
• /
• 2022

Purpose: This study identifies how twelve key success factors of distribution strategies for community enterprises in Thailand achieve higher performances. Research design, data, and methodology: The samples in this study were 400 entrepreneurs throughout the country. The instrument for data elicitation was a questionnaire. The descriptive and inferential statistics for data analysis were percentage, mean, standard deviation, T-Test, F-Test, multiple regression, and multiple correlations. Results: The results revealed that, overall, the samples showed high opinions on online distribution strategies in all aspects. In detail, the three highest factors were as follows: 1) electronic satisfaction, 2) product characteristics and electronic trust, and 3) the quality and success in online distribution. In detail, the three highest aspects of online distribution success were customer loyalty, financial performance, and work management, respectively. The online distribution strategies influencing community enterprises' success were electronic trust, electronic loyalty, social information, electronic satisfaction, and online distribution tools, which had a statistical significance of 71. Conclusions: This research has made an essential contribution to community enterprise entrepreneurs should focus on and adopt these 8P+4ODS concepts to increase sales, maintain brand loyalty of existing customers, get new customers, develop learning, and improve the working potentials of community enterprise entrepreneurs.

• 한국멀티미디어학회논문지
• /
• 제20권11호
• /
• pp.1768-1775
• /
• 2017

The SIP(Session Initiation Protocol) is an application layer call signaling protocol which can create, modify and terminate the session of user, and provides various services in combination with numerous existing protocols. However, most of cryptosystems for SIP cannot prevent quantum computing attack because they have used ECC(Elliptic Curve Cryptosystem). In this paper, we propose a NTRU based authentication and key distribution protocol for SIP in order to protect quantum computing attacks. The proposed protocol can prevent various attacks such as quantum computing attack, server spoofing attack, man-in-the middle attack and impersonation attack anonymity, and our protocol can provide user's anonymity.

• 정보보호학회논문지
• /
• 제1권1호
• /
• pp.29-37
• /
• 1991

여러 Diffie-Hellman형 공용키이분배 프로토콜을 소개한다. 이 프로콜을 GF($2^m$) 의 정규기저를 사용하여 소프트웨어적으로 구현하여 시믈레이션하였다. GF($2^m$) 에서의 승산을 고속으로 할 수 있는 정규지저를 효과적으로 발굴하는 전산 프로그램도 개발하였다.