• Computers and Concrete
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• v.24 no.6
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• pp.541-553
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• 2019

Alkali-silica reaction (ASR) in concrete can induce degradation in its mechanical properties, leading to compromised serviceability and even loss in load capacity of concrete structures. Compared to other properties, ASR often affects the modulus of elasticity more significantly. Several empirical models have thus been established to estimate elastic modulus reduction based on the ASR expansion only for condition assessment and capacity evaluation of the distressed structures. However, it has been observed from experimental studies in the literature that for any given level of ASR expansion, there are significant variations on the measured modulus of elasticity. In fact, many other factors, such as cement content, reactive aggregate type, exposure condition, additional alkali and concrete strength, have been commonly known in contribution to changes of concrete elastic modulus due to ASR. In this study, an artificial intelligent model using artificial neural network (ANN) is proposed for the first time to provide an innovative approach for evaluation of the elastic modulus of ASR-affected concrete, which is able to take into account contribution of several influence factors. By intelligently fusing multiple information, the proposed ANN model can provide an accurate estimation of the modulus of elasticity, which shows a significant improvement from empirical based models used in current practice. The results also indicate that expansion due to ASR is not the only factor contributing to the stiffness change, and various factors have to be included during the evaluation.

• Proceedings of the Technology Innovation Conference
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• 2002.06a
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• pp.157-179
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• 2002

Many advanced scholars and policy makers say that biotechnology is and will be the most important technology in 21th century. And biotechnology has a lots of character which are new and high tech industry, costing too much on early R&D stage and so on. One of them is that it can't be developed all seater by one single firm. So effective and efficient way to solve this generic problem is using the infrastructure which is given by government for flourishing the bio industry, especially, Knowledge infrastructure. The purpose of this study is to understand and give the information about which knowledge infrastructure affects biotechnology firms to obtain competitive advantage in technological improvement. To develop this object, I made 5 variables about infrastructure in biotechnology such as high-skilled researchers infrastructure, R&D policy infrastructure, industrialization infrastructure that supports the biotechnology industry, networking infrastructure between firms, universities, research centers, and finally bio-safety infrastructure. According to this study, to obtain technological competitive advantage for Korean bio firms, all main actors those are government, industry, university, research center they try to develop bio sector at the same time. After this cooperated effort, Korean bio firms and industry can get a international competitiveness in the global society which no one conquer the market.

• Korean Journal of Remote Sensing
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• v.33 no.5_3
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• pp.773-786
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• 2017

This study was to analyze data of climate change impacts on social infrastructure using text-mining methodology, and to visualize the spatial information by integrating those with regional data layers. First of all, the study identified that the following social infrastructure; power, oil and resource management, transport and urban, environment, and water supply infrastructures, were affected by five kinds of climate factors (heat wave, cold wave, heavy rain, heavy snow, strong wind). Climate change impacts on social infrastructure were then analyzed and visualized by regions. The analysis resulted that transport and urban infrastructures among all kinds of infrastructure were highly impacted by climate change, and the most severe factors of the climate impacts on social infrastructure were heavy rain and heavy snow. In addition, it found out that social infrastructure located in Seoul and Gangwon-do region were relatively largely affected by climate change. This study has significance that atypical data in media was used to analyze climate change impacts on social infrastructure and the results were translated into spatial information data to analyze and visualize the climate change impacts by regions.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.6_1
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• pp.485-497
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• 2007

By the rapid development of Information Communication Technology (ICT) and Geo-spatial Technology (GT) and the increased usage of spatial data for planning and infrastructure management, the National Geographic Information System (NGIS) for more efficient and effective utilization of spatial information has been developed by the central government in Korea since 1995. NGIS is the base of Spatial Data Infrastructure (SDI). SDI is developed as one of National Information Infrastructures (NII). Among the hierarchy of SDI, National Spatial Data Infrastructure (NSDI) has very important role in the success of SDI development. Many research articles show that the USA's NSDI initiatives, development strategy have been strongly influenced all over the world. In these viewpoints, to propose the future directions of Korean NGIS, the development of NSDI strategy of USA is reviewed by literature through published book and internet resources. The conclusions of this study are as follow: 1) top-down and bottom-up approach are needed for integrated data sharing and standardization. 2) the creative and evolutionary vision and strategy has to be suggested. 3) the training program and lecture material has to be developed and diffused to the users and providers of spatial data. 4) governance system has to be built for NSDI evaluation. 5) the formation of geo-spatial forum to discuss the spatial-related problems and make research agenda, etc.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.857-880
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• 2016

Due to an increasing number of cyberattacks globally, cybersecurity has become a crucial part of national security in many countries. In particular, the Digital Pearl Harbor has become a real and aggressive security threat, and is considered to be a global issue that can introduce instability to the dynamics of international security. Against this context, the cyberattacks that targeted nuclear power plants (NPPs) in the Republic of Korea triggered concerns regarding the potential effects of cyber terror on critical infrastructure protection (CIP), making it a new security threat to society. Thus, in an attempt to establish measures that strengthen CIP from a cybersecurity perspective, we perform a case study on the cyber-terror attacks that targeted the Korea Hydro & Nuclear Power Co., Ltd. In order to fully appreciate the actual effects of cyber threats on critical infrastructure (CI), and to determine the challenges faced when responding to these threats, we examine factual relationships between the cyberattacks and their responses, and we perform analyses of the characteristics of the cyberattack under consideration. Moreover, we examine the significance of the event considering international norms, while applying the Tallinn Manual. Based on our analyses, we discuss implications for the cybersecurity of CI in South Korea, after which we propose a framework for strengthening cybersecurity in order to protect CI. Then, we discuss the direction of national policies.

• Smart Structures and Systems
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• v.23 no.6
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• pp.579-587
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• 2019

In this paper, pounding tuned mass dampers (PTMDs) were designed to mitigate the multi-mode vortex-induced vibration (VIV) of stay cable utilizing the viscous-elastic material's energy-dissipated ability. The PTMD device consists of a cantilever metal rod beam, a metal mass block and a specially designed damping element covered with viscous-elastic material layer. Wind-tunnel experiment on VIV of stay cable model was set up to validate the effectiveness of the PTMD on multi-mode VIV mitigation of stay cable. By analyzing and comparing testing results of all testing cases, it could be verified that the PTMD with viscous-elastic pounding boundary can obviously mitigate the VIV amplitude of the stay cable. Moreover, the installed location and the design parameters of the PTMD device based on the controlled modes of the primary stay cable, would have a certain extent suppression on the other modal vibration of the stay cable, which means that the designed PTMDs are effective among a large band of frequency for the multi-mode VIV control of the stay cable.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.335-340
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• 2003

Our country is projected the technical development studies, constructed the digital maps, developed standards, established rules, and educated users during the first NGIS plan. This National Geospatial Information Infrastructure is proceeding with the program as arranged. In the second NGIS plan, our government try to construct the framework data for the maximization of GIS utilization. But National Geospatial Information Infrastructure included some problems from view of data framework particularly. In this paper, we make a comparative study of foreign countries, analyze the cause of our problem, and present the standards for Korean National Spatial Data Infrastructure.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.391-396
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• 2003

For efficient maintenance on urban transit infrastructure, computerized system using wireless communication system which allows to inquire necessary data and to record maintenance work on the spot in realtime is required. Also, for efficient maintenance progress on urban transit infrastructure which have geographic data, computerized system united with geographic information system that offers visual information is required. In this paper, investigations on new IT technology and on computerized system of foreign country are conducted. And development direction and model of computerized system for maintenance on urban transit infrastructure are proposed.

• The Journal of Information Systems
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• v.11 no.1
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• pp.105-127
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• 2002

The objective of this study is to analyze factors affecting usage of b2b e-marketplace. For this purpose, we suggest a research framework where the factors are e-business infrastructure, expectation of competitive advantages and perceived barriers with current and future usages as result variables. For empirical test, 219 companies are surveyed and 177 valid ones among them are analyzed. In result, e-business infrastructure and competitive advantage affect to both current and future usage positively and perceived barriers affect to future usage negatively. The results shows the following two: First, many companies expect improvement of competitive advantages such as bargaining power and efficiency by usage of e-marketplace. Second, for more aggressive usage of e-marketplace, it is important not only to build e-business infrastructure but also to resolve perceived barriers.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.2
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• pp.55-65
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• 2016

Distributed Denial of service attack is one of the major threats nowadays especially to the government infrastructure that give huge impact to the reputation and interrupt the services and resource. Our survey start with brief introduction about DDoS attacks, we illustrate the trends and incident happened at government from various countries. We then provide an extensive literature review on the existing research about implication, types of attacks and initiative to defence against the DDoS attacks. Our discussion aims to identify the trends in DDoS attacks, in depth impact of DDoS attacks to government infrastructure, classification of attacks and techniques against the attacks. And we will use for a fire fight safety and management.