• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.755-762
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• 2004

In our country, when the replacement for individual components of equipment in nuclear power plants is required, establishment of individual criteria i.e. Required Response Spectra(RRS) of seismic test/analysis for the component is very difficult because of the absence of Test Response Spectra(TRS) for the individual component to be replaced, from the existing qualification documents. In this case, it is required to perform the structural analysis for the nuclear equipment including the components to be replaced. After the structural analysis, Analysis Response Spectra(ARS) at the point of the component shall be generated and used for seismic test of the component. However, as of today, no standard program authorized for the response spectra generation by using the structural analysis exists in korea. Because of above reason, the STAR-Egs computer program was developed by using the method which calculates directly the expected response spectrum(frequency vs. acceleration type) of the selected points in the nuclear equipment with input spectrum(Required Response Spectra, RRS), based on the dynamic characteristics of the Finite Element(FE) model that is equivalent to the nuclear equipment. The STAR-Egs controls ANSYS/I-DEAS commercial software and automatically extract modal parameters of the FE model. The STAR-Egs calculates response spectrum using the established algorithm based on the extracted modal parameters, too. Reliance on the calculation result of the STAR-Egs was verified through comparison output with the result of MATLAB commercial software based on the identical algorithm. Moreover, actual seismic testing was performed as per IEEE344-1987 for the purpose of program verification by comparison of the FE analysis results.

• Structural Engineering and Mechanics
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• v.8 no.2
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• pp.165-180
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• 1999

The cost effectiveness of using steel roof systems for residential buildings is becoming increasingly apparent with the decrease in manufacturing cost of steel components, reliability and efficiency in construction practices, and the economic and environmental concerns. While steel has been one of the primary materials for structural systems, it is only recently that its use for residential buildings is being explored. A comprehensive system for the design of residential steel roof truss systems is presented. In the first stage of the research the design curves obtained from the AISI-LRFD code for the manufactured cross-sections were verified experimentally. Components of the truss systems were tested in order to determine their member properties when subjected to axial force and bending moments. In addition, the experiments were simulated using finite element analysis to provide an additional source of verification. The second stage of the research involved the development of an integrated design approach that would automatically design a lowest cost roof truss given minimal input. A modified genetic algorithm was used to handle sizing, shape and topology variables in the design problem. The developed methodology was implemented in a software system for the purpose of designing the lowest cost truss that would meet the AISI code provisions and construction requirements given the input parameters. The third stage of the research involved full-scale testing of a typical residential steel roof designed using the developed software system. The full scale testing established the factor of safety while validating the analysis and design procedures. Evaluation of the test results indicates that designs using the present approach provide a structure with enough reserve strength to perform as predicted and are very economical.

• Smart Media Journal
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• v.10 no.3
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• pp.60-67
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• 2021

This study attempted to examine the effects of SW education using EPL and coding robots on computing thinking and problem-solving skills among various teaching and learning methods of software education. To this end, a survey was conducted on 350 students from middle schools A and B in Gwangju and Jeollanam-do, and the difference in mean was analyzed through t-verification and one-way analysis of variance in order to investigate the relationship between variables. Based on the research results obtained through this, we will identify the effects, strengths, and weaknesses of SW education using EPL and coding robots, provide basic data and information for efficient teaching and learning methods of SW education, and further suggest better directions in terms of academic and practical aspects.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.5
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• pp.1089-1097
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• 2019

An era of smart manufacturing is coming through the rapid development of information and communication technology. As a result, many companies have begun to utilize a variety of hardware and software for the efficient business of the manufacturing process. At this time, the hardware and software used are supplied through manufacturing and distribution processes. These supply processes are exposed to a variety of security threats. As the recent cases of supply chain attacks have increased, foreign countries are establishing supply chain management systems and managing supply chain risks. In Korea, on the other hand, there was research on supply chain risk management in some fields. In this paper, we emphasizes the necessity of supply chain risk management through supply chain attack cases. In addition, we analyze trends of foreign supply chain management system and explains the necessity of domestic supply chain security strategy.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.1
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• pp.29-36
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• 2021

The amount of data generated has been growing exponentially, and the complexity of data has been increasing owing to the advancement of information technology (IT). Big data analysts and engineers have therefore been actively conducting research to minimize the analysis targets for faster processing and analysis of big data. Hadoop, which is widely used as a big data platform, provides various processing and analysis functions, including minimization of analysis targets through Hive, which is a subproject of Hadoop. However, Hive uses a vast amount of memory for data deduplication because it is implemented without considering the complexity of data. Therefore, an efficient algorithm has been proposed for data deduplication of complex structures. The performance evaluation results demonstrated that the proposed algorithm reduces the memory usage and data deduplication time by approximately 79% and 0.677%, respectively, compared to Hive. In the future, performance evaluation based on a large number of data nodes is required for a realistic verification of the proposed algorithm.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.2
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• pp.239-248
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• 2012

VANET (Vehicular Ad-hoc Network) is a type of MANET (Mobile Ad-hoc Network) which is the next-generation networking technology to provide communication between vehicles or between vehicle and RSU (Road Side Unit) using wireless communication. In VANET system, a vehicle accident is likely to cause awful disaster. Therefore, in VANET environment, authentication techniques for the privacy protection and message are needed. In order to provide them privacy, authentication, and conditional, non-repudiation features of the group signature scheme using a variety of security technologies are being studied. In this paper, and withdrawal of group members to avoid frequent VANET environment is suitable for vehicles produced by the group administrator for a private signing key to solve the key escrow problem of a group signature scheme is proposed. We proposed a message batch verification scheme using Bloom Filter that can verify multiple messages efficiently even for multiple communications with many vehicles.

• Journal of The Korean Association of Information Education
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• v.25 no.3
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• pp.547-555
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• 2021

The purpose of this study is to develop a Goldberg device-based software(SW) convergence Education tool. The 2015 revised curriculum emphasizes convergence with various subjects for effective SW education. In particular, physics is often used as a material for SW convergence education because it is closely related to computational thinking such as sequential movement, quantification of energy and simulation. In this study, we developed an educational program based on the Goldberg device that utilizes physical knowledge, concepts and manipulation. In order to verify the effectiveness of the program, the survey questions were developed through Delphi verification and a basic satisfaction survey was conducted based on this. As a result, the developed program can be effectively used as a program for SW convergence education.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.242-263
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• 2021

This paper presents a method to implement a low-cost driving simulator for developing autonomous driving algorithms. This is implemented by using GTA V, a physical engine-based commercial game software, containing a function to emulate output and data of various sensors for autonomous driving. For this, NF of Script Hook V is incorporated to acquire GT data by accessing internal data of the software engine, and then, various sensor data for autonomous driving are generated. We present an overall function of the developed driving simulator and perform a verification of individual functions. We explain the process of acquiring GT data via direct access to the internal memory of the game engine to build up an autonomous driving algorithm development environment. And, finally, an example applicable to artificial neural network training and performance evaluation by processing the emulated sensor output is included.

• Journal of The Korean Association of Information Education
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• v.26 no.2
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• pp.121-128
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• 2022

In the 2022 revised curriculum general study released by the Ministry of Education in September 2021, environmental issues are emerging as a socially important topic, with climate and environmental education appearing at the forefront along with software education. In this study, by applying Python Monte Carlo simulation, a program for high school students was developed that combines environmental education and software education emphasized in the 2022 revised curriculum. The developed program verified the validity of the program with Lawshe's Content Validity Ratio for science, environment, and information subject education experts, and the verification results showed that the program meets the development purpose, environment, and information subject achievement standards.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.6
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• pp.1069-1080
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• 2022

Zero trust, which means never trust anything before verifying it, is emerging as a hot issue in security field. After authenticating users, zero trust establishes network boundaries so that only networks in the trusted range can be accessed. This concept is also consistent with the concept of SDP, which performs pre-verification and creates a network boundary with a dynamic firewall so that clients can access only as many as they have permission to connect. Therefore, we recommend the SDP model as an example of how zero trust can be achieved in a zero trust architecture. In this paper, we point out the areas where SDP needs to be modified for zero trust and suggest ways to overcome them. In addition, we propose an onboarding method, which is one of the processes for becoming an SDP entity, and present performance measurement results.