• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.914-934
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• 2016

In the mobile distributed environment, an entity may move across domains with great frequency. How to utilize the trust information in the previous domains and quickly establish trust relationships with others in the current domain remains a challenging issue. The classic trust models do not support cross-domain and the existing cross-domain trust models are not in a fully distributed way. This paper improves the outstanding Certified Reputation (CR) model and proposes a Lightweight Cross-domain Trust (LCT) model for the mobile distributed environment in a fully distributed way. The trust certifications, in which the trust ratings contain various trust aspects with different interest preference weights, are collected and provided by the trustees. Furthermore, three factors are comprehensively considered to ease the issue of collusion attacks and make the trust certifications more accurate. Finally, a cross-domain scenario is deployed and implemented, and the comprehensive experiments and analysis are conducted. The results demonstrate that our LCT model obviously outperforms the Bayesian Network (BN) model and the CR model in our cross-domain scenario, and significantly improves the successful interaction rates of the honest entities without increasing the risks of interacting with the malicious entities.

• Journal of Intelligence and Information Systems
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• v.13 no.3
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• pp.119-140
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• 2007

Recommender systems enable a user to decide which information is interesting and valuable in our world of information overload. As the recent studies of distributed computing environment have been progressing actively, recommender systems, most of which were centralized, have changed toward a peer-to-peer approach. Collaborative Filtering (CF), one of the most successful technologies in recommender systems, presents several limitations, namely sparsity, scalability, cold start, and the shilling problem, in spite of its popularity. The move from centralized systems to distributed approaches can partially improve the issues; distrust of recommendation and abuses of personal information. However, distributed systems can be vulnerable to attackers, who may inject biased profiles to force systems to adapt their objectives. In this paper, we consider both effective CF in P2P environment in order to improve overall performance of system and efficient solution of the problems related to abuses of personal data and attacks of malicious users. To deal with these issues, we propose a multi-agent framework for a distributed CF focusing on the trust relationships between individuals, i.e. web of trust. We employ an agent-based approach to improve the efficiency of distributed computing and propagate trust information among users with effect. The experimental evaluation shows that the proposed method brings significant improvement in terms of the distributed computing of similarity model building and the robustness of system against malicious attacks. Finally, we are planning to study trust propagation mechanisms by taking trust decay problem into consideration.

• Culinary science and hospitality research
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• v.19 no.1
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• pp.103-120
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• 2013

This study aims to examine consumers' trust and purchase intention in environment-friendly agricultural products and factors influencing purchase intention degree of environment-friendly agricultural products. In addition, it aims to help seek national health promotion methods through purchase of consumers' environment-friendly agricultural products by providing the government, businesses, consumer organizations, etc. with basic data on them. The survey was performed for 2 months from August 1, 2012 to September 30, 2012, and a total of 350 questionnaires were distributed and 321(91.7%) copies out of them were used as final analysis data. The results of the study are as follows. First, the analysis of the effects of environment-friendly consumption value on trust in environment-friendly agricultural products showed that all the independent variables including environmental conservation value and economic value had a significant influence on trust in environment-friendly agricultural products, and economic value among them was the most influential item. Second, the analysis of the effects of environment-friendly consumption value on purchase intention for environment-friendly agricultural products showed that all the independent variables including environmental conservation value and economic value had a significant influence on purchase intention for environment-friendly agricultural products, and economic value was the most influential item. Third, the analysis of the effects of trust in environment-friendly agricultural products on purchase intention for environment-friendly agricultural products showed that as trust in environment-friendly agricultural products gets higher, consumers' purchase intention for them increased.

• Journal of Korea Multimedia Society
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• v.9 no.3
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• pp.342-352
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• 2006

Nowadays, Computing environment is changing to ubiquitous. In such ubiquitous computing environments, entities expect to access resources and services at any time from anywhere. Therefore, tile wily how to establish trust relationship among previously unknown devices or resources is needed under such environments. In this paper, we firstly review a model to delegate the trust to communicating entities in ubiquitous environment and its security problems(e.g., malicious right-delegation and revocation of right-delegation). Then, we design a new model for secure delegation over communication entities which is based on two-party signature scheme, and implement it.

• The Journal of Industrial Distribution & Business
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• v.11 no.11
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• pp.19-28
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• 2020

Purpose: The supply of and demand for medical services continue to increase as the current social environment changes. Consequently, competition among medical institutions is intensifying and hospitals must establish appropriate management strategies to improve the medical services they provide. This study suggests that the authenticity of doctors is a factor in improving medical-service quality and examines the effect authenticity has on the affective trust and satisfaction of patients. Design, methodology, and approach: The study utilized previous studies to examine the significance of potential variables, established hypotheses and used a questionnaire to confirm these hypotheses. The questionnaire was distributed to patients who had visited a hospital in the previous six months. Responses were analyzed empirically using structural equation modeling. Findings: The analysis found that a physician's authenticity has a significant impact on the affective trust of patients. While patients' affective trust does not have a similar strong impact on patient satisfaction, physician authenticity does have a significant impact on patient satisfaction. Conclusion and implications: This study examined the roles of authenticity, affective trust, and patient satisfaction in doctor-patient relationships in the medical services field. The implication of the findings is that physician authenticity is a prerequisite for patient satisfaction of medical services.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.4
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• pp.731-751
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• 2021

The Internet of Things is a huge group of devices communicating each other and the interconnection of objects in the network is a basic requirement. Choosing a reliable device is critical because malicious devices can compromise networks and services. However, it is difficult to create a trust management model due to the mobility and resource constraints of IoT devices. For the centralized approach, there are issues of single point of failure and resource expansion and for the distributed approach, it allows to expand network without additional equipment by interconnecting each other, but it has limitations in data exchange and storage with limited resources and is difficult to ensure consistency. Recently, trust management models using fog nodes and blockchain have been proposed. However, blockchain has problems of low throughput and delay. Therefore, in this paper, a trust management model for selecting reliable devices in a fog-based IoT environment is proposed by applying IOTA, a blockchain technology for the Internet of Things. In this model, Directed Acyclic Graph-based ledger structure manages trust data without falsification and improves the low throughput and scalability problems of blockchain.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2337-2344
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• 2013

Mobile Agent is an autonomous mobility technology is being applied in various fields. In particular, mobile agents execution in the Internet environment through the safe execution of the security must be guaranteed. Also, agent to run the agent, the agent's workload should be distributed. In this paper, a trust model based on the security mechanism of the agent execution is proposed. Proposed mechanism to ensure safe execution of the agent was not considered in existing relative researches for rational agent workload distribution and load balancing to improve throughput was. The proposed trust-based security mechanisms for agents to go through security analysis proved safe execution of the agent.

• The KIPS Transactions:PartC
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• v.12C no.7 s.103
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• pp.1015-1024
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• 2005

A delegation of privileges is one of important processes that empower authority to relevant node to process job that user wants in large-stale distributed environment such as Grid Computing. However, existing delegation methods do not give suitable privilege about Job, and do not atomize range of delegation and exists delegation of access privilege for only resources itself that is not delegation about executing process of job itself. Also, they do not apply about process that needs delegation before and after. execution of job such as reservation of system resources or host access before and after execution. Therefore, this paper proposes a method and specification for restricted delegation in distributed environment. Proposed method separates delegation for job side and privilege side, and express specification and procedure of delegation using XML schema and UML and present restricted delegation scenario in distributed computing environment.

• The Korean Journal of Franchise Management
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• v.9 no.4
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• pp.45-56
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• 2018

Purpose - Consumers perceive various risks while using food service franchise stores. Food service franchise stores offer consumers not just menus, but services, physical environment, and prices, which can be perceived as risk to consumers. This means that consumer behavior in foos service franchise stores needs to be studied based on perceived risk theory. Perceived risk consists of performance risk, financial risk, social risk, psychological risk, and time risk. The purpose of this study is to investigate the effects of perceived risk on satisfaction and trust, and in turn affect loyalty. The results of this study will provide guidelines for marketers to develop strategies to reduce the perceived risk of consumers. Research design, data, methodology - In order to achieve research purposes, the authors developed several hypotheses. Data were through online survey through an online survey firm. A questionnaire survey was distributed to customers who have visited the restaurant in the past three months. The survey was conducted from March 5, 2017 to October 14, 2017. A total of 1,500 people were e-mailed and 260 were returned. A total of 245 items were used in the analysis except 15 of the questionnaire. Data was analyzed by using SPSS 21.0 and AMOS 21.0. Results - The findings of this study are as follows: First, performance risk, economic risk, and psychological risk had negative effects on satisfaction. Social and time risks did not affect on satisfaction. Performance risk and time risk had negative impact on trust. Second, economic, social, and psychological risks did not affect trust, but satisfaction had significant positive effect on trust and loyalty. Third, satisfaction had positive effect on loyalty. Conclusions - The implications of this study are as follows. First, food service franchise marketers should increase their customer loyalty by establishing a risk reduction strategy. Second, there are various risks to customers visiting the store. Therefore, marketers need to analyze the perceived risks of customers. Third, it is also necessary to eliminate the perceived risks of customers. In addition, a restaurant franchise company needs to find a reasonable way to reduce the material cost and present a reasonable menu price.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.993-996
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• 1999

A mobile agent is a program which is capable of migrating autonomously from host to host in the heterogeneous network, to perform some computation on behalf of the user. Mobile agents have many advantages in the distributed computing environment. But they are likely to suffer many attacks on the security due to the mobility. In order to make use of a mobile agent in the real applications, the security issues must be addressed. We deal with the problem which is concerned with protecting a mobile agent in transit and detecting a mobile agent clone. In this paper we propose a trust center based secure mobile agent transfer protocol. This protocol transfers a mobile agent securely from host to host and detects a mobile agent clone. We further show the security of the protocol against many attacks.