• Steel and Composite Structures
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• v.42 no.1
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• pp.91-106
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• 2022

Concrete-filled square stainless steel tubes (CFSSST), which possess relatively large flexural stiffness, high corrosion resistance and require simple joint configurations and low maintenance cost, have a great potential in constructional applications. Despite that the use of stainless steel may result in high initial cost compared to their conventional carbon steel counterparts, the whole-life cost of CFSSST is however considered to be lower, which offers a competitive choice in engineering practice. In this paper, a comprehensive experimental and numerical program on 24 CFSSST stub column specimens, including 3 austenitic and 3 duplex stainless steel square hollow section (SHS) stub columns and 9 austenitic and 9 duplex CFSSST stub columns, has been carried out. Finite element (FE) models were developed to be used in parametric analysis to investigate the influence of the tube thickness and concrete strength on the ultimate capacities more accurately. Comparisons of the experimental and numerical results with the predictions made by design guides ACI 318, ANSI/AISC 360, Eurocode 4 and GB 50936 have been performed. It was found that these design methods generally give conservative predictions to the ultimate capacities of CFSSST stub columns. Improved calculation methods, developed based on the Continuous Strength Method, have been proposed to provide more accurate estimations of the ultimate resistances of CFSSST stub columns. The suitability of these proposals has been validated by comparison with the test results, where a good agreement between the predictions and the test results have been achieved.

• Steel and Composite Structures
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• v.52 no.3
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• pp.357-376
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• 2024

In this paper, weakly bonded ultra-high-strength steel bars (UHSS) were used as longitudinal reinforcement in recycled aggregate concrete shear walls to achieve resilient performance. The study evaluated the repairability and hysteresis performance of shear walls before and after retrofitting. Quasi-static tests were performed on recycled aggregate concrete (RAC) and steel fiber reinforced recycled aggregate concrete (FRAC) shear walls to investigate the reparability of resilient shear walls when loaded to 1% drift ratio. Results showed that shear walls exhibited drift-hardening properties. The maximum residual drift ratio and residual crack width at 1% drift ratio were 0.107% and 0.01mm, respectively, which were within the repairable limits. Subsequently, shear walls were retrofitted with bonded X-shaped CFRP strips and steel plates wrapped at the bottom and retested. Except for a slight reduction in initial stiffness, earthquake-damaged resilient shear walls retrofitted with a composite method still had satisfactory hysteresis performance. A revised damage assessment index D, has been proposed to assess of damage degree. Moreover, finite-element analysis for the shear wall before and after retrofit retrofitting was established in OpenSees and verified with experimental results. The finite element results and test results were in good agreement. Finally, parametric analysis was performed.

• Journal of Arbitration Studies
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• v.15 no.2
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• pp.61-91
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• 2005

It is well recognized that the availability of prompt, effective and economical means of dispute resolution is an important element in the orderly growth and encouragement of international trade and investment. Increasingly, ADR(Alternative Dispute Resolution) including arbitration and mediation, instead of litigation in national courts, has become the preferred means of resolving private international commercial disputes. Under the situation, efforts for settlement of trade and investment disputes by ADR have been made between Korea and China through trade and investment agreements and arbitration agreement. Judging from the importance of economic exchange between Korea and Qingdao including Shandong Province, The Korean Commercial Arbitration Board(KCAB) and The Qingdao Arbitration Commission(QAC) should strengthen mutual cooperation to develop efficient methods of resolving commercial disputes arising between the two countries and to assist parties in solving those disputes through conclusion of arbitral agreement. Recently, efforts for conclusion of a Korea-China-Japan Free Trade Agreement(FTA) received strong support at Korea-Japan and Korea-China Summit Meeting held on June and July, 2003 respectively. If the conclusion of FTA among the three countries would be realized, it would promote regional trade and investment, contributing to economic growth in the Northeast Asian region. Under the circumstances, the key arbitral institutions including KCAB and QAC should consider to take the initiative in setting up tentatively called ${\ulcorner}$Joint Arbitration Center for Northeast Asia${\lrcorner}$ for which the CAMCA of NAFTA will be the good example.

• Korean Journal of Construction Engineering and Management
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• v.19 no.2
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• pp.25-37
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• 2018

In recent times, private sector allocates the risk between private sector investors in terms of equity transaction and agreement transaction. The additional risk-allocation have made the cash flows of private sector investors fluctuated and some of the PPP projects delayed. Therefore, analyzing the impact of the risk reallocation between private sector investors on their cash flows is critical for encouraging the private sector participants. In this study, a model to evaluate the financial viability of PPP project is developed based on the discounted cash flow analysis. The model can analyze the variability by equity and agreement transaction by identifying key variables of equity transaction, influence factors of agreement transaction, and relationship between the transactions and investor's profitability. It is expected that the private sector can determine the investment decision for PPP projects when the risk reallocation is occurred.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.312-319
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• 2003

In late 90s, organizations recognized the information technology as an key enabler of the business strategic accomplishment which lead them heavy increment on IT investment. These organizations tried to hold the competitive advantage by focusing on their core competency. And these acts raise their interests on IT outsourcing. Recent trends of the organizations concern on evaluating the effectiveness of the previous IT investment and the reasonable selection on IT investment type. Also, the objective evaluation of the service level and continuous improvement are major concern of the outsourcer. Consequently, interests on Service Level Agreement (SLA), an immanence operating tool for managing the level of the information system service objectively and qualitatively, were raised among IT outsourcing service providers, outsourcers, and operating departments. Yet, only a few domestic conglomerates adopted the SLA, and exact usage of the SLA is currently unknown. Because of the importance of the SLA between a service provider and an outsourcer, the agreement is treated with high confidentiality. This raised the problems to both the private and public organizations, are considering the SLA, with absence of concrete guide line to internalize SLA management process. This study provides the organizational and environmental factors of the adopting and applying the Service Level Agreement (SLA) by conducting multiple case research. The sampled companies are currently implementing the SLA over 1 year of usage period. Factors were used to provide the operational contribution for implementing the SLA. The study also provides the effects on IT performance through the SLA. For this, in depth interview was conducted for each sampled company. As a result, if SLA between outsourcer and service provider can be used as an immanence operation tool and actively implemented, SLA will be an strategic tool for various decision making in IT management practice with long term relationship, better shared partnership, and continuous service improvement.

• Korea Trade Review
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• v.42 no.4
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• pp.185-215
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• 2017

While the future of Trans-Pacific Partnership Agreement is uncertain, TPP did succeed in convincing certain developing countries, which had been reluctant to open its government procurement market in the past, to open their markets. In this paper, we compare the government procurement chapter of TPP with WTO Government Procurement Agreement to see what factors may have convinced these countries to open their government procurement markets. The key factors seem to be an initially very high levels of threshold, coupled with an extended transition period (up to 20 years) to lower the threshold to figures comparable to other countries; and reduction of legal and regulatory burdens dealing with some transparency and procedural requirements. Korea should use these strategies in their future FTA negotiations to try to open foreign government procurement markets. If Korea wants to accede to TPP, it should have very few problems since Korea has similar threshold levels as current TPP members, and legal and regulatory requirements are more strict under GPA, of which Korea is a member.

• Journal of Korean society of Dental Hygiene
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• v.17 no.5
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• pp.921-930
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• 2017

Objectives: The purposes of this study were to analyze the trade newspapers related to 'recognition of the dental hygienist as the healthcare professional' using R program and to identify opinions of groups concerned with dental hygienists. Methods: This study was designed with contents analysis and cross-sectional. The subjects of the study were the articles for the last three years in medical and dental newspapers about the recognition of the dental hygienist as the healthcare professional. The collected articles were categorized and classified for each group's opinions about the issue. The key words were extracted according to the priorities of the opinions of agreement and disagreement. They were visualized after frequency analysis using R, a big data analysis program. Results: A total of 237 newspaper articles were extracted among 270 ones containing opinions. 245 were positive opinions and 25 were negatives. The main key words of the agreement were 'Amendment of Medical Law', 'Medical Practice', and 'Legal Guarantee of the Practice'. Advocates addressed that the issues should be resolved with the amendment of the law, as dental hygienists are not guaranteed to work based on the current law although they are actually doing the medical practices. Main key words of disagreement were 'Legal Guarantee of the Practice', 'Revision of Medical Technician Law', and 'Review of Job Type'. They described that the problem can be resolved by revising medical technicians act, and it needs to consider as job types of all healthcare professional. Conclusions: In the group who showed the positive opinions, it is possible to utilize measures such as promoting the cooperation of dental hygienists and developing public consensus through publicity.

• Journal of the Korea Institute of Building Construction
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• v.13 no.3
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• pp.242-252
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• 2013

Although many researchers and practitioners are in agreement about the potential applicability and benefit of BIM in construction, it is still unclear why BIM is adopted, and what factors enhance the adoption and implementation of BIM. As such, the mechanism of BIM acceptance and use remains in question. Therefore, this paper aims to identify the key factors affecting the acceptance of BIM in construction organizations, and to analyze the effect of intrinsic and extrinsic motivation factors on BIM acceptance. The key factors in BIM acceptance are identified through a literature review in TAM (Davis 1989) and related theories, and consolidated by interviews and pilot studies with professionals in the construction industry. Based on the factors, a questionnaire was designed and sent out to a total of 114 construction organizations in Korea, such as contractors, architects, and engineers. Using SPSS 12.0, the data was analyzed to determine the relationship between intrinsic and extrinsic motivation factors and BIM acceptance through multiple regression analysis. These findings will clarify what the highly prioritized factors are, and can also be used in an assessment tool for the performance of BIM utilization.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.457-462
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• 2006

In UMTS (Universal Mobile Telecommunication System), a protocol called UMTS AKA is used to authenticate MSs (Mobile Stations). When an MS is in a foreign network, the serving network contacts the AuC (Authentication Center) located at the home network of the MS to authenticate it. To reduce this cost, AuC sends n AVs(Authentication Vectors) to the serving network. Although the use of AVs allows the serving network to authenticate an MS without contacting the AuC each time, there are also shortcomings such as synchronization problem. Subsequently, a set of protocols adopting the same or similar method have been proposed. In this paper, we analyze and compare authentication protocols for UMTS with respect to the use of AVs and its alternatives. We conclude that using Kerberos-like ticket key overcomes some of the drawbacks of using AVs, whereas AVs provide much better security.

• Smart Structures and Systems
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• v.13 no.6
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• pp.943-957
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• 2014

When subjected to fatigue loading, the main failure mode of partially prestressed concrete (PPC) structure is the fatigue fracture of tensile reinforcement. Therefore, monitoring and evaluation of the steel stresses/strains in the structure are essential issues for structural design and healthy assessment. The current study experimentally investigates the possibility of using fiber Bragg grating (FBG) sensors to measure the steel strains in PPC beams in the process of fatigue loading. Six full-scale post-tensioned PPC beams were exposed to fatigue loading. Within the beams, the FBG and resistance strain gauge (RSG) sensors were independently bonded onto the surface of tensile reinforcements. A good agreement was found between the recorded results from the two different sensors. Moreover, FBG sensors show relatively good resistance to fatigue loading compared with RSG sensors, indicating that FBG sensors possess the capability for long-term health monitoring of the tensile reinforcement in PPC structures. Apart from the above findings, it can also be found that during the fatigue loading, there is stress redistribution between prestressed and non-prestressed reinforcements, and the residual strain emerges in the non-prestressed reinforcement. This phenomenon can bring about an increase of the steel stress in the non-prestressed reinforcement.