• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.275-281
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• 2020

This study aims to explore a new approach of relationship assessment by partially employing attitudinal commitment to measure the influence on perception of cooperation within the Vietnamese rice supply chains, which begins from commercial enterprises up to the retailers in the Vietnamese market. The quantitative research is first built around the measurement instruments for the constructs of relationship quality (RQ) and its dimensions; next, a questionnaire is designed; finally, we deal with sample issues and analyze the data to answer the research questions. The truncated sampling technique and Likert-scale survey is a suitable method for analyzing Vietnamese rice retailers and data collection. The preliminary test was conducted using SPSS Statistics; the main test was, then, carried out to evaluate the proposed model and test the hypotheses. Appropriately, the results point to a significant influence of attitudinal factors on trust and satisfaction. In addition, with the involvement of perceived trust and satisfaction, that combination showed the mediating effect between the attitudinal factors and the relationship quality. The ad-hoc analysis indicated the significant role of the two mediators. To be more specific, the high degree of trust and satisfaction has a positive impact on the formation of the relationship between participants in the sector.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.2
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• pp.43-51
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• 2017

Recently, MANET has been used in many fields as the range of applications increases. However, the dynamic topology that MANET has makes it difficult to route and provides the cause of exposure to security vulnerabilities. Therefore, the security features that can be robust to many attacks must have been applied in the routing technique provided in the MANET. In this paper, we propose a secure routing method that secure route is established by reliability evaluation of nodes and secure data communication has applied through key exchange mechanism. The proposed technique used hierarchical structure for efficiency of reliability evaluation of nodes. The reliability of nodes is performed by trust management node and reliability of nodes managed periodically is broadcasted. And the key exchange for secure data transmission is dene without CA as the certificate issuing organization. This allows fast key exchange and the integrity of data transmission improved. The proposed technique improves the security of the data transmission because a secure route to the destination node is established by the reliability evaluation and the data transmission is performed after the key between the source node and the destination node is exchanged through the established route.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.1
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• pp.87-93
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• 2013

MANET has the advantage of having the flexibility to build easily a network in a difficult situation that builds a wired network. But, data transmission errors by movement of nodes and eavesdropping by wireless communications have become a problem of security. Authentication service is the most essential in order to overcome these problems and operate network stably. In this paper, we propose 3-tiers authentication structure to exclude of malicious node and operate stable network through more systematic and thorough node authentication. After network is composed into a cluster, cluster head which play CA role is elected. Among these, the highest-CA is elected. The highest-CA receives certificates to cluster head and the cluster head evaluates trust value of their member nodes. Authentication technique which issues member node key is used. We compared PSS and experimented to evaluate performance of proposed scheme in this paper and efficiency of the proposed technique through experience was confirmed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.6214-6242
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• 2019

Routing in mobile ad hoc networks is performed in a distributed fashion where each node acts as host and router, such that it forwards incoming packets for others without relying on a dedicated router. Nodes are mostly resource constraint and the users are usually inclined to conserve their resources and exhibit selfish behaviour by not contributing in the routing process. The trust and reputation models have been proposed to motivate selfish nodes for cooperation in the packet forwarding process. Nodes having bad trust or reputation are detected and secluded from the network, eventually. However, due to the lack of proper identity management and use of non-persistent identities in ad hoc networks, malicious nodes can pose various threats to these methods. For example, a malicious node can discard the bad reputed identity and enter into the system with another identity afresh, called whitewashing. Similarly, a malicious node may create more than one identity, called Sybil attack, for self-promotion, defame other nodes, and broadcast fake recommendations in the network. These identity-based attacks disrupt the overall detection of the reputation systems. In this paper, we propose a reputation-based scheme that detects selfish nodes and deters identity attacks. We address the issue in such a way that, for normal selfish nodes, it will become no longer advantageous to carry out a whitewash. Sybil attackers are also discouraged (i.e., on a single battery, they may create fewer identities). We design and analyse our rationale via game theory and evaluate our proposed reputation system using NS-2 simulator. The results obtained from the simulation demonstrate that our proposed technique considerably diminishes the throughput and utility of selfish nodes with a single identity and selfish nodes with multiple identities when compared to the benchmark scheme.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.75-87
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• 2010

Secure communication has been one of the main challenges in vehicular ad hoc networks(VANET) since broadcast messages from nearby vehicles contain life-critical information for drivers and passengers. So far various secure communication schemes have been proposed to secure the communication in VANET, and they satisfy most security requirements. However most of them need to put trust on roadside units(RSUs), which are usually deployed in unattended area and vulnerable to compromise. In this paper, we propose a secure communication scheme, which does not need to put trust on RSUs. And we adopt a grouping technique to averagely divide the huge burden in the server without jeopardizing the anonymity of users. Moreover we design a complete set of protocols to satisfy common security requirements with a relatively lower hardware requirement. At last, we evaluate the scheme with respect to security requirements, communication overhead, storage overhead and network performance.

• The Journal of Korean Medicine
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• v.31 no.4
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• pp.101-114
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• 2010

Background: Currently, evidence-based medicine is widely propagated as a reference for proper clinical practice. As a result, there is an increasing need for more clinical trials based on Oriental diagnostic methods to evaluate the efficacy of Oriental medicine, including acupuncture and herbal medicine. The purpose of this study was to confirm which symptoms are adequate indicators of effects of Ojeock-san for lower back pain and develop a questionnaire to evaluate its effects. Methods: We interviewed 102 Oriental medical doctors working in Seoul with a preformed questionnaire which included questions about symptoms of lower back pain and indicators for Ojeock-san. We sampled respondents who answered that they trust the effectiveness of Ojeock-san in telephone survey carried out using multistage stratified random sampling technique from March to April, 2009. We categorized the respondents into two groups, differentiating them by gender, career, workplace, and trust level of Ojeock-san effect. Results: About half of the respondents selected 13 questions as the adequate indicators of Ojeock-san for low back pain. There were no differences in the top 11 selected indicators in total selection and top 3 ranking selection. The comparison of frequency of top 13 questions in total selections between the two groups showed no difference. Conclusions: There were 13 symptoms which were considered adequate indicators of effects of Ojeock-san for lower back pain found by many Oriental medical doctors. This questionnaire can be utilized as a diagnostic adjunctive tool, tested for validity and reliability of questionnaires through further studies.

• Convergence Security Journal
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• v.14 no.7
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• pp.17-22
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• 2014

Wireless Ad hoc Network is threatened from many types of attacks because of its open structure, dynamic topology and the absence of infrastructure. Attacks by malicious nodes inside the network destroy communication path and discard packet. The damage is quite large and detecting attacks are difficult. In this paper, we proposed attack detection technique using secure authentication infrastructure for efficient detection and prevention of internal attack nodes. Cluster structure is used in the proposed method so that each nodes act as a certificate authority and the public key is issued in cluster head through trust evaluation of nodes. Symmetric Key is shared for integrity of data between the nodes and the structure which adds authentication message to the RREQ packet is used. ns-2 simulator is used to evaluate performance of proposed method and excellent performance can be performed through the experiment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.1
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• pp.57-64
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• 2017

In order to reduce damages to major railroad components, which have the potential to cause interruptions to railroad services and safety accidents and to generate unnecessary maintenance costs, the development of rolling stock maintenance technology is switching from preventive maintenance based on the inspection period to predictive maintenance technology, led by advanced countries. Furthermore, to enhance trust in accordance with the speedup of system and reduce maintenances cost simultaneously, the demand for fault diagnosis and prognostic health management technology is increasing. The objective of this paper is to propose a highly reliable learning model using various machine learning algorithms that can be applied to critical rolling stock components. This paper presents a model for railway rolling stock component fault diagnosis and conducts a mechanical failure diagnosis of motor components by applying the machine learning technique in order to ensure efficient maintenance support along with a data preprocessing plan for component fault diagnosis. This paper first defines a failure diagnosis model for rolling stock components. Function-based algorithms ANFIS and SMO were used as machine learning techniques for generating the failure diagnosis model. Two tree-based algorithms, RadomForest and CART, were also employed. In order to evaluate the performance of the algorithms to be used for diagnosing failures in motors as a critical railroad component, an experiment was carried out on 2 data sets with different classes (includes 6 classes and 3 class levels). According to the results of the experiment, the random forest algorithm, a tree-based machine learning technique, showed the best performance.

• Convergence Security Journal
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• v.14 no.4
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• pp.3-8
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• 2014

Wireless Ad hoc Network is threatened from many types of attacks because of its open structure, dynamic topology and the absence of infrastructure. Attacks by malicious nodes inside the network destroy communication path and discard packet. The damage is quite large and detecting attacks are difficult. In this paper, we proposed attack detection technique using secure authentication infrastructure for efficient detection and prevention of internal attack nodes. Cluster structure is used in the proposed method so that each nodes act as a certificate authority and the public key is issued in cluster head through trust evaluation of nodes. Symmetric Key is shared for integrity of data between the nodes and the structure which adds authentication message to the RREQ packet is used. ns-2 simulator is used to evaluate performance of proposed method and excellent performance can be performed through the experiment.

• International Commerce and Information Review
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• v.12 no.2
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• pp.59-83
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• 2010

The purposes of the study is to evaluate the discrepancy between user's expectation and satisfaction degree in the service of uTradeHub. In this regard, this study infers general solutions in order to induce the intersection area using IPA technique. Then this paper will present directions to improve the service of uTradeHub. In terms of methodology, this article disclosed that IPA model approach is greatly useful to evaluate user's attribute. First, variables like the link of different works(f1), trust of system(f4), information connection(f7) are located on the first quadrant. This means that importance and satisfaction are all high variables for user. So, this is very important variables that need continuous administration in order to maintain present state. Second, variables such as the speed of information acquisition(f2), improvement of use(f3), stability of system(f5) are located on the second quadrant. This means that user's importance is high but user's satisfaction is low. Therefore, this area needs an active improvement strategy and quick maintenance for e-Trade application. Third, variables like the appropriateness of information usage fees(f8), easy subscription(f9), customer support service(f10) are located on the third quadrant. Because these variables are all low for user's importance and satisfaction, we have to arrange strong and radical remedy for e-Trade service. Finally, variables like information offer(f6) are located on the fourth quadrant. This means that user's satisfaction is high but user's importance is low. The research result suggests that e-Trade service development would be re-organised as much as user feels the importance of process innovation.