• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.1
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• pp.104-109
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• 2005

The aircraft gas turbine engines with the Electronic Engine Controls(EEC) had been developed to save fuel and enhance their performance in the early days, and had employed the health monitoring function in the Full Authority Digital Engine Controls(FADEC) to improve their reliability. This has led to an increasing demand for the certification technology of these controls. The design and certification issues of power supply, aircraft supplied data, failure modes, software verification/validation, and lightning requirements need to be addressed. This paper presents the design considerations and the certification techniques applied to the electronic engine controls. And it is believed that this paper will be basis to establish a requirement in Korean Airworthiness Standard.

• Journal of the Korea Society for Simulation
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• v.16 no.3
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• pp.19-28
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• 2007

We considered the authoritative representations of torpedo systems that was the engagement level model to develop system specifications and to analyze operational requirements on concept design phase. The Work Breakdown Structure(WBS) of models was defined about authoritative representations of the torpedo systems. The communication of information among each subsystems and input/output parameters were defined. In the heavy weight and light weight torpedo model, presetter, underwater maneuver, war head, sonar, guidance and control, propulsion subsystem modeling were developed for heavy-weight and the light-weight torpedo systems. The authoritative representations of torpedo systems have similar structures with those of the engineering level models and could be verified via engagement level simulations according to the V&V process in the future.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1718-1724
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• 2017

Recently, Smart plugs for real time monitoring of household appliances based on IoT(Internet of Things) have been activated. Through this, consumers are able to save energy by monitoring real-time energy consumption at all times, and reduce power consumption through alarm function based on consumer setting. In this paper, we measure the alternating current from a wall power outlet for real-time monitoring. At this time, the current pattern for each household appliance was classified and it was experimented with deep learning to determine which product works. As a result, we used a cross validation method and a bootstrap verification method in order to the classification performance according to the type of appliances. Also, it is confirmed that the cost function and the learning success rate are the same as the train data and test data.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.353-362
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• 2007

Unlike large satellites, small satellites, such as nanosatellite and microsatellite, can provide a limited interior space for components mounting. In order to mitigate this issue, the compact Bus Electronic Unit(BEU) that integrates satellite electronic modules, combining most of bus subsystems and payload electronic modules into one unit, has been developed for HAUSAT-2 nanosatellite. This paper addresses the design and environmental test result analyses of BEU. The vibration and thermal vacuum tests were conducted at qualification level for the verification of design margin of newly developed BEU. The performance of individual electronic subsystem modules has been verified through performance tests before and after the qualification tests. It was confirmed that the natural frequency of BEU satisfies the design stiffness requirement without structural damage in the vibration test. Thermal analysis results were also almost consistent with test results through modified thermal analysis modeling.

• Journal of the Korea Society of Computer and Information
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• v.26 no.10
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• pp.167-172
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• 2021

After the Ferry Sewol accident, public interest in marine safety has increased. However, as the marine leisure tourism population increases, the number of casualties caused by marine accidents is increasing, so marine safety education is urgently needed. Since facilities related to marine safety education in Korea are geographically biased to the west, regional imbalances in education are significant. Therefore, this study suggested solutions to the problems of developing educational contents and securing budgets and professionals by using idle facilities of the Korea Institute of Maritime and Fisheries Technology(KIMFT) located in Busan as a maritime safety education center. In addition, as a result of estimating demand using the gravity model, it was estimated that the demand would range from 150,000 to 130,000 per year. This study sufficiently proved social policy validity for policy suggestions using existing idle sites as maritime safety education centers based on objective verification methods and is expected to contribute substantially to policy promotion in the future.

• Convergence Security Journal
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• v.18 no.3
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• pp.141-148
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• 2018

The purpose of this study is to analyze the safety needs and life satisfaction of users of security system. The contents of the questionnaire consisted of "safety need, use satisfaction, life satisfaction". As a result of the analysis, Chronbach's alpha coefficient was calculated as 0.897 for safety needs, 0.888 for use satisfaction, and 0.887 for life satisfaction. The items were found to have internal consistency. In the validation of discriminant validity, both AVE and CR values were found to be 0.6 or more than the reference value of 0.8. The intuitiveness of the variables used in this study was found to be largely secured. As the hypothesis test result, the standardization factor was calculated as 0.993 for 'safety needs ⇨ use satisfaction' and 0.453 for 'use satisfaction ⇨ life satisfaction', and both hypotheses were positive. As a result of the verification, it was analyzed that the higher the user's safety needs, the higher the use satisfaction, and the higher the use satisfaction, the higher the life satisfaction.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.5
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• pp.323-331
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• 2019

In this study, a computational model approach for the modeling of hydrodynamic pressures acting on radial gates during strong earthquakes is proposed. The use of the dynamic layering method with the Arbitrary Lagrangian Eulerian (ALE) algorithm and the SIMPLE method for simulating free reservoir surface flow in addition to moving boundary interfaces between the fluid domain and a structure due to earthquake excitation are suggested. The verification and validation of the proposed approach are realized by comparisons performed using the renowned formulation derived by the experimental results for vertical and inclined dam surfaces subjected to earthquake excitation. A parameter study for the truncated lengths of the two-dimensional fluid domain demonstrates that twice the water level leads to efficient and converged computational results. Finally, numerical simulations for large radial gates with different curvatures subjected to two strong earthquakes are successfully performed using the suggested computational model.

• 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 Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.95-103
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• 2022

Quick and accurate understanding of the situation in a severe accident is essential for conducting the appropriate accident management and response using the accident diagnosis information. This study employed deep learning technology to diagnose severe accidents through the major safety parameters transferred from a nuclear power plant (NPP) to AtomCARE. After selecting the major accident scenarios to consider, a learning database was established for particular scenarios affiliated with major scenarios by performing a large number of severe accident analyses using MAAP5 code. The severe accident diagnosis technology, which classifies detailed accident scenarios using the major safety parameters from NPPs, was developed by training it with the established database . Verification and validation were conducted by blind test and principal component analysis. The technology developed in this study is expected to be extended and applied to all severe accident scenarios and be utilized as a base technology for quick and accurate severe accident diagnosis.

• Journal of Software Assessment and Valuation
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• v.10 no.1
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• pp.19-26
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• 2014

In this paper, we propose a method for protecting Android applications against reverse engineering attacks. In this method, the server encrypts the original executable code (DEX) included in an APK file, inserts into the APK file a stub code that decrypts the encrypted DEX later at run-time, and distributes the modified APK file. The stub code includes an integrity validation code to detect attacks on itself. When a user installs and executes the APK file, the stub code verifies the integrity of itself, decrypts the encrypted DEX, and loads it dynamically to execute. Since the original DEX is distributed as an encrypted one, we can effectively protect the intellectual property. Further, by verifying the integrity of the stub code, we can prevent malicious users from bypassing our method. We applied the method to 15 Android apps, and evaluated its effectiveness. We confirmed that 13 out of them operates normally.