• Nuclear Engineering and Technology
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• v.50 no.3
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• pp.519-525
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• 2018

Obtaining knowledge of the absorbed dose up-taken by a certain material when it is exposed to a specific ionizing radiation field is a very important task. Even though there are a plenitude of methods for determining the absorbed dose, each one has its own strong points and also drawbacks. In this article, an innovative idea for the development of a new gamma-ray dosimetry system is proposed. The method described in this article is based on optical colorimetry techniques. A color standard is fixed to the back of a BK-7 glass plate and then placed in a point in space where the absorbed dose needs to be determined. Gamma-ray-induced defects (color centers) in the glass plate start occurring, leading to a degree of saturation of the standard color, which is proportional, on a certain interval, to the absorbed dose. After the exposure, a high-quality digital image of the sample is taken, which is then processed (MATLAB), and its equivalent $I_{RGB}$ intensity value is determined. After a prior corroboration between various well-known absorbed dose values and their corresponding $I_{RGB}$ values, a calibration function is obtained. By using this calibration function, an "unknown" up-taken dose value can be determined.

• Structural Engineering and Mechanics
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• v.55 no.6
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• pp.1121-1137
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• 2015

High powered computers and engineering computer systems allow designers to routinely simulate complex physical phenomena. The presented work deals with the analysis of two finite element method optimization techniques (First Order Method-FOM and Subproblem Approximation Method-SAM) implemented in the individual Design Optimization module in the Ansys software to analyze the behavior of real problems. A design optimization is a difficult mathematical process, intended to find the minimum or maximum of an objective function, which is mostly based on iterative procedure. Using optimization techniques in engineering designs requires detailed knowledge of the analyzed problem but also an ability to select the appropriate optimization method. The methods embedded in advanced computer software are based on different optimization techniques and their efficiency is significantly influenced by the specific character of a problem. The efficiency, robustness and accuracy of the methods are studied through strictly convex two-dimensional optimization problem, which is represented by volume minimization of two bars' plane frame structure subjected to maximal vertical displacement limit. Advantages and disadvantages of the methods are described and some practical tips provided which could be beneficial in any efficient engineering design by using an optimization method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2732-2753
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• 2019

With the application of wireless sensor networks in the fields of ecological observation, defense military, architecture and urban management etc., the security problem is becoming more and more serious. Characteristics and constraint conditions of wireless sensor networks such as computing power, storage space and battery have brought huge challenges to protection research. Inspired by the danger theory in biological immune system, this paper proposes an intrusion detection model for wireless sensor networks. The model abstracts expressions of antigens and antibodies in wireless sensor networks, defines meanings and functions of danger signals and danger areas, and expounds the process of intrusion detection based on the danger theory. The model realizes the distributed deployment, and there is no need to arrange an instance at each sensor node. In addition, sensor nodes trigger danger signals according to their own environmental information, and do not need to communicate with other nodes, which saves resources. When danger is perceived, the model acquires the global knowledge through node cooperation, and can perform more accurate real-time intrusion detection. In this paper, the performance of the model is analyzed including complexity and efficiency, and experimental results show that the model has good detection performance and reduces energy consumption.

• Journal of Korean Elementary Science Education
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• v.38 no.1
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• pp.87-101
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• 2019

The purpose of this study was to investigate elementary school teachers' perception and the status of education program on science museum field trips by using a questionnaire (188 teachers) and interview (6 teachers). The results of the research are as follows. First, factors influencing elementary school teachers who choose the science museum as a place for field trips were 'student's interest', 'teacher's own experience related to the science museum', 'science curriculum', 'suggestions from a fellow teacher', 'space available for field work' and so on. Second, 82% of the respondents conducted pre-education program, but they mainly conducted safety education. Third, the teacher conducted post-education program less than pre-education program. In the post-education program, the most activities were to express and share knowledge and experience gained from the science museum. Fourth, 52.2% of the teachers provided tasks or activity sheets during science museum field trips. Fifth, the teachers mainly served as safety guide. In addition, the teachers thought that safety guide was the most important role of teacher in science museum field trips. Sixth, the teachers thought that the method of viewing the science museum's collection, which emphasizes the role of docent rather than the teacher, was more educational.

• Journal of Engineering Education Research
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• v.21 no.6
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• pp.81-89
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• 2018

Patents have been recognized as a core knowledge asset which are closely related with company's technological competitiveness. However, only a small portion of patents are actually contributing to the profit of the company. In addition, it costs a lot of money continuously to maintain the patent rights regardless of their values. Thus, effective methodologies are required to create patents with high values. It is examined what kind of differences exist between high value patents and the others in the use of TRIZ methodologies. For the purpose, we analyzed the US granted patents of Samsung Electronics. The analysis shows that there is no significant difference in the use of inventive principles, but high value patents utilize 'separation by condition' the most where as the others 'separation by space' the most frequently in the use of separation principles. In the use of standard solutions, high value patents use the 'class 2' principles frequently than the others.

• Journal of the Korean Society of Clothing and Textiles
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• v.43 no.4
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• pp.491-505
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• 2019

This study analyzes global fashion clusters to provide insight for the domestic fashion market to form a competitive fashion cluster. We examine formation factors and operation types of the global fashion clusters to understand their characteristics. We also explore the effectiveness of each global fashion cluster by investigating the stage of development in fashion clusters. Fourteen cases of global fashion clusters are collected and analyzed. First, global fashion clusters show three types of formation and operation: self-formation, self-formation & government based development, and government, institute, and enterprise based formation & development. Second, the characteristics of global fashion clusters are based on functions related to space, learning, innovation, network, and knowledge. Third, there are four steps in the development stage of global fashion clusters: professional clusters, industrial clusters, learning clusters and innovative industrial clusters. In particular, innovative industrial clusters, the final stage of development, have high levels of effectiveness in terms of co-growth and collaboration among fashion-related businesses in fashion clusters. The results of this study can help guide the development of local fashion cluster in Korea.

• Safety and Health at Work
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• v.10 no.3
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• pp.341-346
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• 2019

Background: Although the concept of workload is important to nursing practice, only a few nursing researchers have focused on the issue of workload within the nursing context. Knowledge of how the dynamics of workload affects the job stress of nurses working in a specific unit or department in a hospital setting, and the influence of coworker support on this relationship, still remains limited. This study, therefore examined the effect of workload on job stress of Ghanaian outpatient department nurses and the moderating effect of coworker support on this relationship. Methods: A cross-sectional survey design was used, and questionnaire was used to collect data from a sample of 216 outpatient department nurses from four major hospitals in Ghana. The data collected measured workload, job stress, and coworker support using National Aeronautics and Space Administration (NASA) Task Load Index, job stress scale, and coworker support scale, respectively. Data were analysed using descriptive statistics, correlation, and hierarchical regression. Results: High levels of workload were associated with high levels of job stress of the nurses. Also, higher levels of workload were related to higher levels of job stress for nurses who received high levels of coworker support, but this was not the case for those who received low levels of coworker support (reserve buffering effect). Conclusion: The finding reiterates the adverse effect of workloads on employees' health, and the reverse buffering effect implies that supporting a colleague at work should be conveyed in a positive manner devoid of negative appraisal.

• International Journal of Computer Science & Network Security
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• v.21 no.9
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• pp.151-154
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• 2021

State information policy is an important component of foreign and domestic policy of the country and covers all spheres of society. The rapid development of the information sphere is accompanied by the emergence of fundamentally new threats to the interests of the individual, society, state and its national security. The article considers the components of the state information policy to ensure information security of the country and identifies the main activities of public authorities in this area. Internal and external information threats to the national security of Ukraine and ways to guarantee the information security of the country are analyzed. Information security is seen as a component of national security, as well as a global problem of information protection, information space, information sovereignty of the country and information support of government decisions. Approaches to ensure the process of continuity of the information security system of the state in order to monitor new threats, identify risks and levels of their intensity are proposed.

• Progress in Medical Physics
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• v.31 no.3
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• pp.124-134
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• 2020

Here we review the evolutionary history of radiation therapy technology through the festschrift of articles in celebration of the 30th anniversary of Korean Society of Medical Physics (KSMP). Radiation therapy technology used in clinical practice has evolved over a long period of time. Various areas of science, such as medical physics, mechanical engineering, and computer engineering, have contributed to the continual development of new devices and techniques. The scope of this review was restricted to two areas; i.e., output energy production and functional development, because it is not possible to include all development processes of this technology due to space limitations. The former includes the technological transition process from the initial technique applied to the first model to the latest technique currently used in a variety of machines. The latter has had a direct effect on treatment outcomes and safety, which changed the paradigm of radiation therapy, leading to new guidelines on dose prescriptions, innovation of dose verification tools, new measurement methods and calculation systems for radiation doses, changes in the criteria for errors, and medical law changes in all countries. Various complex developments are covered in this review. To the best of our knowledge, there have been few reviews on this topic and we consider it very meaningful to provide a review in the festschrift in celebration of the 30th anniversary of the KSMP.

• The Journal of Information Systems
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• v.31 no.2
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• pp.19-43
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• 2022

Purpose Due to the COVID-19 pandemic, many companies are building virtual workplaces based on virtual reality technology. Through this study, we intend to identify the trend of convergence and convergence research between virtual reality technology and work space, and suggest future promising fields based on this. Design/methodology/approach For this purpose, 12,250 bibliographic data of research papers related to Virtual Reality (VR) and Workplace were collected from Scopus from 1982 to 2021. The bibliographic data of the collected papers were analyzed using Text Mining and Pathfinder Network, Parallel Neighbor Clustering, Nearest Neighbor Centrality, and Triangle Betweenness Centrality. Through this, the relationship between keywords by period was identified, and network analysis and visualization work were performed for virtual reality-based workplace research. Findings Through this study, it is expected that the main keyword knowledge structure flow of virtual reality-based workplace convergence research can be identified, and the relationship between keywords can be identified to provide a major measure for designing directions in subsequent studies.