• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.92-101
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• 2020

It is necessary to develop a rational method for evaluating the safety of bridges for the passage of inseparable crane vehicles exceeding the limit weight. In this study, the same method applied to the development of the recently introduced reliability-based highway bridge design code - limit state design method is applied to the calibration of the live load factor for the crane vehicle. Structural analysis was performed on the concrete bridge and the required strengths of the previous design code, the current design code and AASHTO LRFD were compared. When comparing the unfactored live load effect, the live load of the crane was greater than that of the current and previous design code. When comparing the required strength by applying the calibrated live load factor, the previous design code demands the largest strength and the current design code and the crane live load effect yields similar value. The results of safety evaluation of the actual bridges on the candidate route for the crane passage secured the same reliability as the target reliability index required by the design code and the strength of the cross section of the actual bridge is calculated greater than the required strength for the passage of the crane, which confirms the safety for the passage of the crane.

• The Korean Society of Law and Medicine
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• v.22 no.4
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• pp.59-88
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• 2021

The National Assembly of the Republic of Korea recently enacted laws to fortify sanctions about data manipulation of pharmaceutical companies. The medicine approval system is the result of legislative efforts to prevent accidents that caused damages to patients' life and health. The medicine approval system is based on the trust that the data submitted by pharmaceutical companies is not manipulated. The Supreme Court of Korea clarified that strict standard shoud be required to secure the medicine safety in Supreme Court Decision 2008Du8628 decided November 13, 2008. We agree. This paper suggest legislation to weaken the economic incentives for pharmaceutical companies to choose data manipulation by minimizing the expected profit. In addition to revoking the marketing authorization of the medicine, the 'unfair' profits the pharmaceutical company has earned must be recovered. In addition, in order to increase the possibility to discover data manipulation, it is necessary to strengthen the review capacity and to activate the whistle-blowing.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.107-118
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• 2022

The social need for stable hydrogen storage technologies that respond to the increasing demand for hydrogen energy is increasing. Among them, underground hydrogen storage is recognized as the most economical and reasonable storage method because of its vast hydrogen storage capacity. In Korea, low-depth hydrogen storage using artificial protective structures is being considered. Further, establishing corresponding safety standards and ground stability evaluation is becoming essential. This study evaluated the hydro-mechanical behavior of the ground during a hydrogen gas leak from a low-depth underground hydrogen storage facility through the HM coupled analysis model. The predictive reliability of the simulation model was verified through benchmark experiments. A parameter study was performed using a metamodel to analyze the sensitivity of factors affecting the surface uplift caused by the upward infiltration of high-pressure hydrogen gas. Accordingly, it was confirmed that the elastic modulus of the ground was the largest. The simulation results are considered to be valuable primary data for evaluating the complex analysis of hydrogen gas explosions as well as hydrogen gas leaks in the future.

• Journal of Korea Water Resources Association
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• v.55 no.3
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• pp.177-189
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• 2022

The purpose of this study is to apply the d4PDF (Data for Policy Decision Making for Future Change) constructed from a large-scale ensemble climate simulation to estimate the probable rainfall with low frequency and high intensity. In addition, this study analyzes the uncertainty caused by the application of the frequency analysis by comparing the probable rainfall estimated using the d4PDF with that estimated using the observed data and frequency analysis at Geunsam, Imsil, Jeonju, and Jangsu stations. The d4PDF data consists of a total of 50 ensembles, and one ensemble provides climate and weather data for 60 years such as rainfall and temperature. Thus, it was possible to collect 3,000 annual maximum daily rainfall for each station. By using these characteristics, this study does not apply the frequency analysis for estimating the probability rainfall, and we estimated the probability rainfall with a return period of 10 to 1000 years by distributing 3,000 rainfall by the magnitude based on a non-parametric approach. Then, the estimated probability rainfall using d4PDF was compared with those estimated using the Gumbel or GEV distribution and the observed rainfall, and the deviation between two probability rainfall was estimated. As a result, this deviation increased as the difference between the return period and the observation period increased. Meanwhile, the d4PDF reasonably suggested the probability rainfall with a low frequency and high intensity by minimizing the uncertainty occurred by applying the frequency analysis and the observed data with the short data period.

• Journal of Industrial Convergence
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• v.20 no.11
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• pp.113-126
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• 2022

In Small and Medium-sized Enterprises(SMEs) compared to major, competence of CEO relatively has a large impact on management performance, so the biggest factor to strengthen the competitiveness is the competence of CEO. Meanwhile, a consultant is defined as a subject of execution that directly and indirectly participates in management by inducing objective and rational decision-making on various management issues and problems facing companies. The management expertise, problem-solving skills, communication skills, insights, and leadership that a consultant must have in order to perform his or her duties are the same as the role and capabilities that the CEO must have in enhancing the company's performance and competitiveness. Therefore, through previous studies, this study divided consultant competences of CEO into job competence, communication competence, learning competence, and innovation competence and tried to understand whether those competences affect corporate's innovation performance and management performance. The survey was conducted on SMEs and the analysis techniques were reliability and validity analysis, confirmatory factor analysis, and structural equation analysis. As a result, it was found that the CEO's job competence, communication competence, learning competence, and innovation competence had a significant effect on innovation performance of the company, and second, innovation performance had a significant effect on the management performance. Through, this study derived a common factor of consultant competences of SMEs CEO, and derived implications for the competence characteristics of the CEO necessary to improve the performance of SMEs.

• Korean Association of Arts Management
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• no.52
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• pp.39-73
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• 2019

The purpose of this study is to explore the issues and alternatives in the promotion of space and exhibition support projects in visual arts, and to suggest an applicable direction of the government grant program. For this study, FGI and in-depth interviews were conducted in the direct beneficiaries of the grant program, the staff of the grant program, and the group of visual arts expert. As a result, the deliberation and selection of the support project should be carried out with sufficient time in consideration of the specificity of the support project. And the project requires to divide into two kinds of the projects based on the understanding of the social role and differentiation of non-profit exhibition spaces and private art museums. For the grant application and assessments, a long-term support is necessary to bring the capability and issues in efficient allocation of the budget, flexibility of budget item, and the budget shortfalls. Furthermore, the reliability between the grant program and beneficiaries needs to form a healthy partnership, and the evaluation criteria and eNARADOEUM system should be more practical and rationally established. Through this analysis, the implications of understanding the specificity of visual arts support projects, establishment of sustainable visual arts creation policies, and budget utilization were derived. Consequently, cultural and artistic support projects were directed to place more emphasis on efficiency than control, direction considering the position of consumers than suppliers, and long-term business planning rather than short-term perspective.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.227-234
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• 2008

This study examines which models are more suitable for representing mechanical property of unbound materials to analyze behavior of asphalt pavement structure. Results from FWD (Falling Weight Deflectometer) test were used to apply to nonlinear elastic model. The new method which can deduct material constants of nonlinear elastic model is suggested from FWD test data rather than laboratory resilient modulus ($M_R$) test. It is confirmed that the material constants are within the common range in subbase. Test output from FWD and MDD (Multi-Depth Deflectometer) was used to verify reliability of the model. From the results of verification, this study shows that a non-linear elastic model agrees to MDD test data more than a linear elastic model does.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2C
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• pp.109-120
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• 2006

SPT-Uphole test is a seismic field test using receivers on ground surface and a SPT (Standard penetration test) source in depth. Even though this method is simple and economic, it makes hesitate to apply in real field that it is difficult to obtain reliable travel time information of shear wave because of the characteristics of SPT impact source. To overcome this shortcoming, in this paper, modified SPT-Uphole method using two component surface geophones was suggested. Numerical analysis was performed using finite element method for understanding the characteristics of surface motion induced by in-depth vertical source, and comparison study of the various methods which determine the travel time information in SPT-Uphole method was performed. In result, it is thought that the most reasonable method is using the first local maximum point of the root mean square value signals of vertical and horizontal component in time domain. Finally, modified SPT-Uphole method using two component surface geophones was performed at the site, and the applicability in field was verified by comparing wave velocity profiles determined by the SPT-Uphole method with the profiles determined by SASW method and SPT-N values.

• Journal of the Korean Geosynthetics Society
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• v.22 no.4
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• pp.17-26
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• 2023

To consider the risk of damage and fracture of P.C strands, the existing post-maintenance system alone has the limitations, hence it is necessary to quantitatively evaluate and predict the deterioration, durability and safety of facilities and establish a reasonable maintenance system considering the asset value of facilities. Therefore, it is worth considering a preventive maintenance plan that allows proactive measures to be taken before a major defect occurs in the temporary anchor. This study devised a preventive over tension method, reviewed its effectiveness through design and field tests, by calculating the resistance factors by performing a reliability-based optimization design. At this time, the over tension anchor method was evaluated using the ratio of the residual tension force after the fracture of P.C strands to the effective tension force before the fracture of P.C strand, followed by the resistance factor calculated by the optimal solution for each random variables using Excel solver and applying it to the limit state equations. As a result of the study, if the over tension ratio is 125% to 130%, the remaining strands showed a high resistance effect even after the fracture of P.C strand. As a result of the optimization design, it was found that it is appropriate to apply the load factor (γ) of 1.25, and the resistance factors of Φ₁, Φ₂, Φ₃ as 0.7, 0.5, 0.6.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.6
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• pp.1077-1086
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• 2023

The searchable encryption model allows to selectively search for encrypted data stored on a remote server. In a real-world scenarios, the model must be able to support multiple search keywords, multiple data owners/users. In this paper, these models are referred to as Multi Ranked Searchable Encryption model. However, at the time this paper was written, the proposed models use fully-trusted trapdoor centers, some of which assume that the connection between the user and the trapdoor center is secure, which is unlikely that such assumptions will be kept in real life. In order to improve the practicality and security of these searchable encryption models, this paper proposes a new Multi Ranked Searchable Encryption model which uses random keywords to protect search words requested by the data downloader from an honest-but-curious trapdoor center with an external attacker without the assumptions. The attacker cannot distinguish whether two different search requests contain the same search keywords. In addition, experiments demonstrate that the proposed model achieves reasonable performance, even considering the overhead caused by adding this protection process.