• Structural Monitoring and Maintenance
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• v.4 no.3
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• pp.221-236
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• 2017

In this study, the feasibility of vibration-based damage alarming algorithms are numerically evaluated for wind turbine tower structures which are subjected to harmonic force excitation. Firstly, the algorithm of vibration-based damage alarming for the wind turbine tower (WTT) is visited. The natural frequency change, modal assurance criterion (MAC) and frequency-response-ratio assurance criterion (FRRAC) are utilized to recognize changes in dynamic characteristics due to a structural damage. Secondly, a finite element model based on a real wind turbine tower is established in a structural analysis program, Midas FEA. The harmonic force is applied at the rotor level as presence of excitation. Several structural damage scenarios are numerically simulated in segmental joints of the wind turbine model. Finally, the natural frequency change, MAC and FRRAC algorithm are employed to identify the structural damage occurred in the finite element model. The results show that these criteria could be used as promising damage existence indicators for the damage alarming in wind turbine supporting structures.

• Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.197-203
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• 2012

In this paper, study the substantial issues which occurs upon free flight environment by performing separation assurance under multiple conflict(over 3 Aircraft), recovery en route under the terms of time constrains and fixed way point after the conflict avoidance, correlations between conflict detection distance and separation assurance by utilizing Autonomous flight algorithm. Result of this experiment demonstrates that the extension of detection distance is advantageous to solution of separation assurance and enhancing of flight efficiency, choose to maneuver by applying time constrain terms and fixed way point according to the situation of conflict prediction in case of recovery maneuver after the conflict avoidance. And separation assurance can be solved by applying 2 degrees or more of bank angle. When choosing the optimal bank angle could be drastically improved flight efficiency.

• Journal of the Korean Society of Combustion
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• v.22 no.3
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• pp.47-52
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• 2017

The propellant tile and crack which account for the greatest proportion of solid rockets are profoundly affected by viscosity and mechanical properties of solid propellant. In this paper HTPB/AP/Al system propellant has been researched for the viscosity, mechanical properties and burning properties with type and contents of bonding agents. The viscosity of propellant was changed significantly depending on the type and contents of bonding agents, and mechanical properties of HTPB/AP/Al system propellant were also varied. Considering both lower viscosity and stable mechanical properties, the optimum type and contents of bonding agents can be identified as the main factors to the HTPB/AP/Al system propellant.

• Journal of Korean Society for Quality Management
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• v.44 no.4
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• pp.907-920
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• 2016

Purpose: This study was designed to examine the casual relationships among startup internship service quality and entrepreneurial capability, entrepreneurial intention in startup education. Also, we intended to explore significant factors on use entrepreneurial intention through causal model analysis in the viewpoint of total effect. Methods: Questionnaire, as a research tool, has gotten validity and reliability through literature study, exploratory study and pretest and sample 123 was selected. To carry out statistical treatment of pretest and main analysis, SPSS18.0 were employed and regression model was employed as analysis method. Results: Result of this study shows as follows. Three factors (empathy, responsiveness and assurance) have an effect entrepreneurial capability and entrepreneurial intention. We found that with an importance of empathy, responsiveness and assurance can be useful and significant factors in causal relationship of startup internship education. Conclusion: The present study shows that three factors(empathy, responsiveness and assurance) in via of entrepreneurial capability and entrepreneurial intention, were important factors that related startup education have to emphasize to raise performance, And also we confirmed new 5 factor 'empathy, responsiveness, assurance, reliability and tangibles'through this study. However, the present study has some limitations to be studied in the future.

• Korean Journal of Computational Design and Engineering
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• v.16 no.2
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• pp.92-103
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• 2011

The construction industry consists of various and massive architectural information as an architectural process includes a variety of design stages with cooperation of many disciplines. A Building Information Modeling (BIM) serves as a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life-cycle from inception onward. building SMART has developed Industry Foundation Classes (IFC) standard for interoperability of BIM based information. Several software tools are already IFC-compliant. However, there are a lot of problems related to efficient interoperability of software owing to the lack of guide regarding the software usage and insufficiency IFC interfaces of software. The purpose of this study is to suggest efficient IFC support interface development methodologies of existing IFC certified software. The scope of this study is interoperability test for open BIM based quality assurance. To achieve this purpose, the authors have classified subject of open BIM based quality assurance and investigated IFC certification process and certified software. In addition, the authors have exported and imported via IFC files using different IFC interfaces in the software for interoperability of architectural objects and their properties. Finally, the authors have suggested IFC support interface development methodologies and hereafter direction for efficient interoperability of IFC certified software based on open BIM.

• Convergence Security Journal
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• v.19 no.1
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• pp.31-40
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• 2019

Today, information security (INFOSEC) as a discipline is gaining more and more importance according to the emergence and extension of the cyberspace. Originated from Joint Doctrine for Information Operation (Joint Pub 3-13) by the U.S. Department of Defense, 'information assurance (IA)' is the concept widely used in the relevant field. Grown from the practice of information security, it encompasses broader and more proactive protection that includes countermeasures and repair, security management throughout an information system (IS)'s life-cycle, and trustworthiness of an IS in the process of risk analysis. In Korea, many industry professionals tend to misunderstand IA, remaining unaware of the conceptual differences between IA and INFOSEC. On this account, the current study attempted to provide a combined definition of IA by reviewing relevant literature. This study showed the validity of the wordings used in the proposed definition phrase by phrase.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.5
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• pp.57-67
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• 2003

Security Policy Model is a structured representation using informal, semiformal or formal method of security policy to be enforced by TOE. It provides TOE to get an assurance to mitigate security flaws resulted from inconsistency between security functional requirements and functional specifications. Therefore, Security Policy Model has been required under an hish evaluation assurance level on an evaluation criteria such as ISO/IEC 15408(Common Criteria, CC). In this paper, we present an evaluation method for security policy model based on assurance requirements for security policy model in Common Criteria through an analysis of concepts, related researches and assurance requirements for security policy model.

• Journal of Distribution Science
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• v.19 no.7
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• pp.5-17
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• 2021

Purpose: The distribution of goods and the flow of information, determined by consumer behavior toward online shopping, is drastically popular worldwide. This study examines some factors such as brand trust, online sales promotion, consumer personality, delivery service, quality assurance, information search, and online consumer satisfaction influence online shopping behavior. Research design, data, and methodology: A constructed questionnaire in an online survey was conducted with 241 random cluster respondents in the greater Jakarta Area. Structure equation model was utilized to analyze and verify all the data. Results: Research finding indicates online sales promotion, delivery service, quality assurance, and online consumer satisfaction positively influence information search. Meanwhile, brand trust, quality assurance, and information search positively influence online shopping behavior. However, the result illustrates that consumer personality negatively influences both information search and online shopping behavior. Conclusions: To influence online shopping behavior, the most important factors that need to be considered by marketplaces are quality assurance. It positively motivates Indonesia's citizens to collect information and make unplanned purchases. The study finding can be a reference for brands to maintain and build outstanding product quality, an informational website, and an excellent marketing strategy so that customers can meet their expectations. Besides, it also broadens both companies' and individuals' knowledge about the digital revolution on consumer behavior.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.4
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• pp.33-40
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• 2020

A sturdy on the adhesion properties of solid propellants, liners, and insulation was carried out according to the types of barrier coats. A barrier coats were used to prevent migration of the plasticizer or curative between the propellant/liner/insulation, and the barrier coat was selected out of Isocyanates with different molecular weight and number of -NCO in one molecule. As a result, it was found that the more the -NCO group and the larger molecular weight, the stronger adhesion. In addition, as a result of experiments about effects of the pot life after applying the barrier coat on bond strength, the adhesion strength was shown to increase as the pot life was short.

• Structural Engineering and Mechanics
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• v.82 no.6
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• pp.771-783
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• 2022

Structural damage identification (SDI) methods have been proposed to monitor the safety of structures. However, the traditional SDI methods using modal parameters, such as natural frequencies and mode shapes, are not sensitive enough to structural damage. To tackle this problem, this paper proposes a new SDI method based on transmissibility assurance criterion (TAC) and weighted Schatten-p norm regularization. Firstly, the transmissibility function (TF) has been proved a useful damage index, which can effectively detect structural damage under unknown excitations. Inspired by the modal assurance criterion (MAC), TF and MAC are combined to construct a new damage index, so called as TAC, which is introduced into the objective function together with modal parameters. In addition, the weighted Schatten-p norm regularization method is adopted to improve the ill-posedness of the SDI inverse problem. To evaluate the effectiveness of the proposed method, some numerical simulations and experimental studies in laboratory are carried out. The results show that the proposed method has a high SDI accuracy, especially for weak damages of structures, it can precisely achieve damage locations and quantifications with a good robustness.