• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.1
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• pp.1-8
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• 2014

Using the level set and the meshfree methods, we develop a topological shape optimization method applied to linear elasticity problems. Design gradients are computed using an efficient adjoint design sensitivity analysis(DSA) method. The boundaries are represented by an implicit moving boundary(IMB) embedded in the level set function obtainable from the "Hamilton-Jacobi type" equation with the "Up-wind scheme". Then, using the implicit function, explicit boundaries are generated to obtain the response and sensitivity of the structures. Global nodal shape function derived on a basis of the reproducing kernel(RK) method is employed to discretize the displacement field in the governing continuum equation. Thus, the material points can be located everywhere in the continuum domain, which enables to generate the explicit boundaries and leads to a precise design result. The developed method defines a Lagrangian functional for the constrained optimization. It minimizes the compliance, satisfying the constraint of allowable volume through the variations of boundary. During the optimization, the velocity to integrate the Hamilton-Jacobi equation is obtained from the optimality condition for the Lagrangian functional. Compared with the conventional shape optimization method, the developed one can easily represent the topological shape variations.

• Journal of the Korean Data and Information Science Society
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• v.28 no.4
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• pp.769-781
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• 2017

The purpose of this study was to investigate the effects of nurses' perceived burden from work and health problems on the presentism of nurses. The study subjects were recruited from four general and tertiary hospitals in K province and D metropolitan city. A quarter of nurses had shoulder, back, and neck pain and average number of health problems was 3.62. The nurses' presenteeism score was $43.37{\pm}12.43$ points out of 100 points. There was a statistically significant relationship between nurses' perceived burden, numbers of health problems, and presenteeism. The numbers of health problems and perceived burden of nurses had significant effects on presenteeism of nurses while controlling demographic factors such as length of work experience, job position, types of hospital, and gender. These results suggested that the less burden from work and the lower number health problems could result in the lower level of presenteeism of nurses. Therefore, it is necessary to develop diverse strategies to reduce the burden of nurses and health problems at both individual and organizational levels as a way to increase productivity of hospital.

• The Korean Journal of Air & Space Law and Policy
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• v.21 no.2
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• pp.97-121
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• 2006

Inter-Korean exchanges using civil aviation has been continuing since the temporary direct air route from Pyongyang to Seoul was opened on June 15th, 2000 for the summit meeting with North Korea. In this paper, I analyze the North Korea Aviation law by focusing on the differences with South Korean Aviation law. While South Korean Aviation law is modeled on the Pandect system, North Korean Aviation law can only be understood by looking at North Korea's socialist ideology. Therefore, North Korean Aviation law has some expressions which can hardly be understood. With respect to the source of aviation law, both South and North Korea are in compliance with the Convention on International Civil Aviation (Signed at Chicago, on 7 December, 1944). Thus, they established the aviation law based on the standards and recommendations provided by ICAO. For this reason, they have similar legal systems and composition. From this analysis, a few differences are also derived regarding aircraft ownership, airports, airline liability, aircraft accident investigation organization and aviation insurance. It is important to note that this paper has a particular limitation. Not only is the information about North Korean law very limited, but North Korea also does not provide easy access to its national legal codes. This paper describes the legal comparison of South and North Korea by focusing on the formation and framework of North Korean aviation law.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.3
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• pp.253-266
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• 2016

In accordance with the classification system of radioactive waste in Korea, all the disused sealed radioactive sources (DSRSs) fall under the category of EW, VLLW or LILW, and should be managed in compliance with the restrictions for the disposal method. In this study, the management and disposal method are drawn in consideration of half-life of radionuclides contained in the source and A/D value (i.e. the activity A of the source dividing by the D value for the relevant radionuclide, which is used to provide an initial ranking of relative risk for sources) in addition to the domestic classification scheme and disposal method, based on the characteristic analysis and review results of the management practices in IAEA and foreign countries. For all the DSRSs that are being stored (as of March 2015) in the centralized temporary disposal facility for radioisotope wastes, applicability of the derivation result is confirmed through performing the characteristic analysis and case studies for assessing quantity and volume of DSRSs to be managed by each method. However, the methodology derived from this study is not applicable to the following sources; i) DSRSs without information on the radioactivity, ii) DSRSs that are not possible to calculate the specific activity and/or the source-specific A/D value. Accordingly, it is essential to identify the inherent characteristics for each of DSRSs prior to implementation of this management and disposal method.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.1
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• pp.103-112
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• 2012

This study aims at assessment of local festivals focused on analysis of operation program for local festivals held in Jeonbuk province. The subjects were 65 local festivals held in Jeonbuk in 2010 excluding festivals held in province, county, and town level, and those held with single purpose. Type of festivals were classified to type for residents' unity, tourism, industry, and special purpose type. The portion was industry type 36.9%, type for residents' unity 23.1% in the order. By theme, animal, plant, nature phenomenon, history, culture and tradition, special product, regional industry were classified - the portion was special product 36.9%, culture and tradition 24.6%, history 13.8%. Assessment of operation program was conducted with assessment indexes such as compliance with theme, uniqueness, diversity, effect of experience, size, educational effect, and entertainment. As a result, it appeared that because local festivals of Jeonbuk had high uniqueness, duplication of program between local festivals was very low and educational effect was comparatively high. On the other hand, because entertainment and effect of experience was very low, considerations of entertainment and effect of experience are necessary in planning of program.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.185-191
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• 2015

This paper suggest the safety class communication board in order to design the safety network of the nuclear safety class controller. The reactor protection system use the digitized networks because from analog system to digital system. The communication board shall be provided to pass the required performance and test of the safety class in the digital network used in the nuclear safety class. Communication protocol is composed of physical layer(PHY), data link layer(MAC: Medium Access Control), the application layer in the OSI 7 layer only. The data link layer data package for the cyber security has changed. CRC32 were used for data quality and the using one way communication, not requests and not responses for receiving data, does not affect the nuclear safety system. It has been designed in accordance with requirements, design, verification and procedure for the approving the nuclear safety class. For hardware verification such as electromagnetic test, aging test, inspection, burn-in test, seismic test and environmental test in was performed. FPGA firmware to verify compliance with the life-cycle of IEEE 1074 was performed by the component testing and integration testing.

• Korean Security Journal
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• no.61
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• pp.137-161
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• 2019

The purpose of this research is to explore ways to improve private security officers' compliance with security policies by analyzing the effects of transformational leadership and organizational trust. Data were collected from private security officers employed in the cities of Seoul and Busan by using survey questionnaire. Statistical analyses were conducted with SPSS 22.0 and AMOS 23.0. The results showed that transformational leadership increased organizational trust which was found to have a positive effect on willingness to comply with security policies. In addition, transformational leadership did not affect willingness to comply with security policies directly but had an indirect effect on it through organizational trust. The findings of current research suggest the leaders of security businesses consider various ways to increase officers' organizational trust such as improved job security and benefits in order to maximize their willingness to comply with security policies.

• The Journal of Bigdata
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• v.3 no.2
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• pp.19-33
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• 2018

Owing to the increase of FTA, food trade, and versatile preferences of consumers, food import has increased at tremendous rate every year. While the inspection check of imported food accounts for about 20% of the total food import, the budget and manpower necessary for the government's import inspection control is reaching its limit. The sudden import food accidents can cause enormous social and economic losses. Therefore, predictive system to forecast the compliance of food import with its preemptive measures will greatly improve the efficiency and effectiveness of import safety control management. There has already been a huge data accumulated from the past. The processed foods account for 75% of the total food import in the import food sector. The analysis of big data and the application of analytical techniques are also used to extract meaningful information from a large amount of data. Unfortunately, not many studies have been done regarding analyzing the import food and its implication with understanding the big data of food import. In this context, this study applied a variety of classification algorithms in the field of machine learning and suggested a data preprocessing method through the generation of new derivative variables to improve the accuracy of the model. In addition, the present study compared the performance of the predictive classification algorithms with the general base classifier. The Gaussian Naïve Bayes prediction model among various base classifiers showed the best performance to detect and predict the nonconformity of imported food. In the future, it is expected that the application of the abnormality detection model using the Gaussian Naïve Bayes. The predictive model will reduce the burdens of the inspection of import food and increase the non-conformity rate, which will have a great effect on the efficiency of the food import safety control and the speed of import customs clearance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.535-546
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• 2019

The purpose of this research was to analyze the relationship between human risk factors and evacuation behavior stages for tunnel safety. Therefore, we conducted a survey using a structured questionnaire on the relationship between safety facilities and safety behavior in order to derive an optimized interaction between the two. The research subjects were 141 tunnel users who understand the tunnel environment. The survey period was from June 24, 2018, to September 28, 2018. As data analysis methods, we employed a frequency analysis, a multiple regression analysis, and an independent-sample t-test. In the analysis of the correlation between the human risk factors and the major variables of evacuation behavior, the evacuation phases 1, 2, and 3 were all correlated with acceleration and delay, and the human risk factors were partially correlated. In the multiple regression analysis, the will to comply with laws (${\beta}=0.188$, p=0.034) and information recognition within the tunnel (${\beta}=0.220$, p=0.009) were factors that influence the relationship between human risk factors and evacuation behavior, indicating 12% explanatory power of the impact of human risk factors for the acceleration of evacuation behavior 3. The important variables between human risk factors and evacuation behavior were compliance with laws and information recognition in tunnels. Hence, it is necessary to study the elements that interact with the environment in the tunnel.

• Journal of Aerospace System Engineering
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• v.15 no.3
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• pp.71-78
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• 2021

Since most functions of modern aircraft are controlled by software, software errors are directly related to aircraft safety. The criterion in Chapter 15 of the MIL-HDBK-516C addresses safe development and verification of military aircraft software. As the U.S. Air Force repeatedly experienced non-compliance with Chapter 15 criterion of the MIL-HDBK-516C, it published an Airworthiness Circular (AC-17-01) as a guide to meeting the criterion. In this paper, Chapter 15 of MIL-HDBK-516C, AC-17-01 and the SW Qualification Guideline (DO-178C) as applied by the Federal Aviation Administration are compared and analyzed. For the analysis, a matching ratio formula between the MIL-HDBK-516C criteria specified in AC-17-01 and the DO-178C specified in MIL-HDBK-516C criteria is defined. The sections that satisfy MIL-HDBK-516C criterion are derived when AC-17-01 or DO-178C matches. Based on the analysis results, the aircraft software development process is established and examples of application of Chapter 15 of MIL-HDBK-516C are addressed.