• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1273-1288
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• 2016

With the swift growth of wireless technologies, an increasing number of users rely on the mobile services which can exchange information in mobile networks. Security is of key issue when a user tries to access those services in this network environment. Many authentication schemes have been presented with the purpose of authenticating entities and wishing to communicate securely. Recently, Chou et al. and Farash-Attari presented two ID authentication schemes. They both claimed that their scheme could withstand various attacks. However, we find that the two authentication schemes are vulnerable to trace attack while having a problem of clock synchronization. Additionally, we show that Farash-Attari's scheme is still susceptible to key-compromise impersonation attack. Therefore, we present an enhanced scheme to remedy the security weaknesses which are troubled in these schemes. We also demonstrate the completeness of the enhanced scheme through the Burrow-Abadi-Needham (BAN) logic. Security analysis shows that our scheme prevents the drawbacks found in the two authentication schemes while supporting better secure attributes. In addition, our scheme owns low computation overheads compared with other related schemes. As a result, our enhanced scheme seems to be more practical and suitable for resource-constrained mobile devices in mobile networks.

• Journal of Welding and Joining
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• v.27 no.1
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• pp.65-70
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• 2009

Ir-192 radiation sealed sources are widely employed to the therapeutic applications as well as the non-destructive testing. Production of Ir-192 sources requires a delicate but robust welding technique because it is employed in a high radioactive working environment. A GTA(Gas Tungsten Arc) welding technique is currently well established for this purpose. However, this welding method requires a frequent replacement of the electrode, which results in the delay of the production to take a preparatory action such as to isolate the radiation sources from the working place before getting access to the welding machine. Hence, a resistance welding technique is considered as an alternative method of the GTA welding technique. The advantages of resistance welding are high welding speed and high-rate production. Also it has very long life of electrode comparing to GTA welding. In this study, the resistance welding system and proper welding conditions were established for sealing Ir-192 source capsule. As a results of various experiments, it showed that electrode displacement can be employed as a indicator to predict welding quality. We proposed two mathematical models(linear and curvilinear) to estimate electrode displacement with process parameters such as applied force, welding current and welding time by using regression analysis method. Predicting results of both linear and curvilinear model were relatively good agreement with experiment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.5
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• pp.885-896
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• 2013

MTC(Machine Type Communications), providing a variety of services anytime and anywhere by connecting the cellular network to the machine and things without human intervention, is being considered as a major challenge of the next-generation communications. Currently, When a massive MTC devices simultaneously connect to the network, each MTC device needs an independent access authentication process. Because of this process, authentication signaling congestion and overload problems will cause in LTE-Advanced. In this paper, we propose a group-based authentication protocol and a key management protocol. For managing the MTC devices as group units, the proposed protocol elects a group leader and authentications only once with the core network. After the authentication is completed, a group leader manages the rest members and MME(Mobility Management Entity) by constructing a binary tree. Finally, the propose protocol analysis show that the proposed protocol not only can reduces the authentication signaling which generated in between the MTC devices and the core network but also can manages the MTC devices, efficiently.

• Journal of Distribution Science
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• v.16 no.7
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• pp.57-65
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• 2018

Purpose - Recently, internet access and social network utilization using smart phone are increasing. In such a smart environment, interactive activities such as information generation, information searching and information sending are increasing rapidly on-line environment. Therefore, consumers tend to purchase something according to eWOM and also meet the social consensus online environment. In connectivity society, consumers became accessible and engaged in the opinions of others easily. Many decisions that seem like personal decisions are actually social decisions on online connectivity. This paper seeks to explore factors that can help generate a social decision on purchasing of new products in an online environment. Research design, data, and methodology - The process of collecting a lot of wisdom and making an agreement online is called social decision. The purpose of this paper is to examine empirically the influence of factors such as online ties, online eWOM expectancy and online information behavior on online social decision. In addition, We studied online social decision by analyzing the moderating effect of new product innovation. To understand this structural relationship, research hypotheses and research models were set up and empirical analysis was conducted. In order to verify the hypothesis, 208 questionnaires were collected from the residents of Seoul city/Gyeonggi province. The answered questionnaire verifies reliability and validity using SPSS/AMOS and test hypotheses through path analysis and multiple regression analysis. Results - According to the research results, First, online ties don't have a positive impact on online social decision, Second, online eWOM expectancy have a positive impact on online social decision. Third, online information behaviors have a positive impact on online social decision. The degree of innovation of new products have a moderating effect between Independent variables of three factors and dependent variable of social decision. Conclusions - Social decisions have a positive impact on purchasing decisions about new product. There is a great significance in the fact that the online social influence and online social decision have been studied academically. It is meaningful that we have studied in depth the changing phenomenon of consumer purchase decision process in smart environment. The results of these studies provide academic and practical implications.

• Journal of the Korean Society for information Management
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• v.34 no.2
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• pp.159-180
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• 2017

This study analyzed changes to copyright policies in KCI journals comparatively using the previous 2 research results published in 2008 and 2016 and then gave insight into the meaning of the changes. The results of the study are as follows: Journals making the subject of copyright public had increased from 34% in 2008 to 67% in 2016. Journals transferring copyright from authors remained almost the same, with only a slight increase from 90% to 91% in the same period. Journals using the term 'publication rights' instead of 'copyright' had decreased; on the other hand, journals using the term 'reproduction right' and 'right of transmission' had increased. Use of copyright transfer agreement had increased from 25% to 50%; on the other hand, self archiving policy remained almost the same, decreasing slightly from 13% to 12%. This study argues that these changes mean the establishment of copyright industrialization for Korean journals and that the publishing bodies appear to be the most powerful main agent among stakeholders participating in scholarly publishing in this process.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.18
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• pp.159-188
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• 2002

International joint ventures are usually formed and managed by domestic companies and foreign investors for the common objectives. They offer an opportunity for each partner to benefit significantly from the comparative advantages of the other. Local partners bring knowledge of the domestic market; familiarity with government bureaucracies and regulations; understanding of local labor markets; and existing manufacturing facilities. Foreign partners can offer advanced process and product technologies, management know-how, and access to export markets. In Korea, joint ventures have been encouraged to usher in foreign investors with foreign currency capital badly needed during the IMF financial crisis. In the meantime, Korean laws and regulations with respect to joint ventures have been largely overhauled to promote foreign direct investment (FDI) both inbound and outbound. They include four types of FDI, i.e., acquisition of foreign stocks, provision of long-term loans, participation in joint operations like resources development, and establishment of foreign offices. From the legal point of view, the formal joint venture agreement must be an offspring of a series of tough negotiations between domestic and foreign partners. They usually stress the long-term relationship with the good will and dedication to each other, and restrict the free transfer of stocks. Both partners are earnestly interested in the ownership and management of the joint venture. So they keep a close eye on the articles of incorporation, changes of business environment, conflict resolution methods, transparency of accounting and other financial matters. When a multinational corporation (MNC) is involved in the joint venture, conflicts over management strategies, marketing and other issues take place more often than not between the MNC and local partners. We have to pay attention to joint ventures, particularly, in China and North Korea. As witnessed in other transition economies, China is eagerly bringing in foreign direct investments for the development of nation's economy. China encourages foreign investors to establish ordinary joint ventures, contractual joint ventures, solely invested foreign capital companies and jointly operated development companies with local partners. In North Korea, however, joint ventures have a different meaning like contractual joint ventures in China, in which North Korean partners have an initiative in the management. Rather, jointly operated companies or simply processing-for-wage companies are recommended in view of the unpredictable legal infrastructure in North Korea.

• The KIPS Transactions:PartC
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• v.16C no.2
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• pp.183-188
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• 2009

Wireless sensor networks will be broadly deployed in the real world and widely utilized for various applications. A prerequisite for secure communication among the sensor nodes is that the nodes should share a session key to bootstrap their trust relationship. The open problems are how to verify the identity of communicating nodes and how to minimize any information about the keys disclosed to the other side during key agreement. At any rate, any one of the existing schemes cannot perfectly solve these problems due to some drawbacks. Accordingly, we propose a new pre-distribution scheme with the following merits. First, it supports authentication services. Second, each node can only find some indices of key spaces that are shared with the other side, without revealing unshared key information. Lastly, it substantially improves resilience of network against node capture. Performance and security analyses have proven that our scheme is suitable for sensor networks in terms of performance and security aspects.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.467-470
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• 2005

There are about 10 motors for tile actuator of the automation system in an auto-mobile recently. The performance of the motor-case is much related to the noise and the vibration of an auto-mobile Multi-Forming process is so much the better than existing deep-drawing or Multi-step forming by press by less cost, installation and staff. But there isn't the specific and general process design, so we aren't good at competition. So in the first step, I want to study about the core design for the multi-forming process. We can access by the elasto-plastic theory and the finite element method, and we use a commercial package of the Deform-2D and, Deform-3D which is based on three-dimensional elasto-plastic finite element, evaluated propriety oi the package. The evaluation of the package propriety was simulated by simple bending example. It was found the elasto-plastic theory was mostly in agreement with the simulation. We proposed that three type of section for the core and analyzed by finite element method (Deform-2D). We can get the best result with the ellipse type core. Then we apply the result of the preceding analysis to the finite element method (Deform-3D). In 3D-finite element analysis, we can get the result of 8/100mm-roundness. This result can help the improvement of the multi-forming process.

• KIISE Transactions on Computing Practices
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• v.21 no.4
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• pp.308-314
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• 2015

Usability has become an important consideration for product development, and as a result, there is a growing need for systems and tools that can support usability test projects. However, few studies so far have developed such systems and tools. During a usability test project, many participants take up different roles, such as project managers, usability testers, and subjects. We implement a web-based usability test system with which a project manager can manage and control all participants and documents throughout the entire usability test process, from the design of a usability test project to the analysis of the test results. A usability test generates many documents, such as subject agreement forms and before/after questionnaires. Since many different subjects can participate in a usability test, consistency during testing with different participants and efficient document management are the keys to success for a usability test. Since all users that participate in usability test projects can access web-based usability test systems through a web browser, regardless of the place where they are, the reliability of the testing results can improve since the tests are conducted in the locations where the target products are meant to be used. In particular, our system is useful for disabled individuals who cannot move.

• Convergence Security Journal
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• v.19 no.1
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• pp.49-60
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• 2019

Medical record is part of the personal information that values the dignity and value of an individual, and can lead to serious social prejudice and disadvantage to an individual when it is breached illegally. In addition, the medical record has been highly threatened because its value is relatively high, and external threats are continuing. In this paper, we propose a medical record sharing framework that guarantees patient's privacy based on blockchain using ciphertext policy-based attribute based proxy re-encryption scheme. The proposed framework first uses the blockchain technology to ensure the integrity and transparency of medical records, and uses the stealth address to build the unlinkability between physician and patient. Besides, the ciphertext policy attribute-based proxy re-encryption scheme is used to enable fine-grained access control, and it is possible to share information in emergency situations without patient's agreement.