• Steel and Composite Structures
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• v.53 no.2
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• pp.243-252
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• 2024

Conventional carbon mild steel is a type of steel known for its low carbon content and generally used in the construction industry. Its easily formable and weldable properties make this steel a widely preferred material for buildings, bridges and various construction projects. Other advantages of these steels are their low cost and good mechanical properties. However, high temperatures have an impact on the microstructure and mechanical characteristics of these materials. When high temperatures are present during a fire, steels show significant microstructural changes. Elevated temperatures often decrease the mechanical characteristics of steels. For this purpose, evaluating the post-fire behavior of conventional structural mild steel is an important issue in terms of safety. A combined experimental and parametric study was conducted to estimate fire damage to steel buildings, which is an important issue in the construction field. Tensile test coupons were cut from conventional structural S235JR mild steel sheets with thicknesses ranging from 6 mm to 12 mm. These samples were exposed to temperatures as high as 1200 ℃. After heat treatment, the specimens were allowed to naturally cool to ambient temperature using air cooling before being tested. A tensile test was performed on these coupons to evaluate their mechanical properties after fire, such as their elastic modulus, yield strength, and ultimate tensile strength. The mechanical behavior of conventional S235JR structural steel changed significantly when the heating temperature reached 600℃. The thickness of the steel had a negligible effect on yield strength loss, with the highest measured loss being 50% for 8 mm thickness at 1200℃. For thinner sections (6 mm), yield strength decreased by up to 40%, while thicker samples (12 mm) showed similar reductions. Ultimate tensile strength also showed minimal changes up to 600℃, but beyond this point, a notable decline occurred, with approximately 30% strength loss at 1200℃. The modulus of elasticity remained almost constant up to 800℃, but at 1200℃, the loss reached around 20% for thicker sections (10 mm and 12 mm) and up to 35% for thinner sections (6 mm and 8 mm). Overall, high temperatures led to significant deterioration in both yield and ultimate strength, with a general loss of load-bearing capacity above 600℃. A new equation was formulated from experimental results to predict changes in the mechanical properties of S235JR steels. This equation offers a precise evaluation of buildings made from conventional structural S235JR mild steel after fire exposure. Furthermore, the empirical equation is applicable to low-strength steels with yield strengths ranging from 235 MPa to 420 MPa.

• The Journal of Industrial Distribution & Business
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• v.10 no.3
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• pp.73-83
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• 2019

Purpose - This study is to clarify the structural relationship between the direct supervisor and organizational commitment and organizational citizenship behavior through mediation of the Leader-member exchange (LMX) in the hospital organization, and to confirm the mediating effect of the LMX. Through this study, we will provide basic data on the aspects of HR to enhance organizational immersion and organizational civic behavior in hospital organizations, and present suggestions on academic contribution and effective organizational operation measures. Research design, data, and methodology - This study is to investigate the relationship between authentic leadership and OC and OCB of the organization member, which is proposed to secure more active and high competitiveness in the recent changing medical environment, with multi-regression and B&K(1986) method. For this purpose, 653 employees of senior hospitals in Seoul and Kyeong-In area were surveyed using structured questionnaires. Each questionnaire was composed of 7-point scale, and each hypothesis was testified by multiple leaner regression and by BK method for testifying mediator effect. Result - As a result of the analysis, it was found that the male and non-medical staff had higher recognition level than the medical staff in the LMX, organizational commitment and organizational citizenship behavior. In the senior management or more than 5 years' experience group, organizational commitment and organizational citizenship behavior were recognized higher than the group of subordinate managers. Second, authentic leadership has a positive influence on LMX, organizational commitment and organizational citizenship behavior, and LMX has a significant positive impact on organizational commitment and organizational citizenship behavior. In addition, as a result of analyzing LMX mediating effect in the relationship of authentic leadership and organizational effectiveness by BK method, LMX had partial mediating effects between authentic leadership and organizational citizenship behavior, and between authentic leadership and organizational commitment. Conclusion - Results of the study confirmed that all the members of the hospital organization that were lacking served as positive factors for the relationships of authentic leadership and LMX, and authentic leadership and organizational effectiveness. It is expected that the hospital organization will be able to suggest such as the organizational approach to expect high organizational effectiveness centering on authentic leadership ability as psychological capital.

• The Journal of Korean Society for School & Community Health Education
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• v.1 no.2
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• pp.105-125
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• 2000

The purpose of this study was to examine the influence of school safety accident on teacher's normal educational activities and to seek some desirable ways to cope with it. The subjects in this study were 351 class teachers randomly selected from Seoul and Kyonggi Province and surveyed from April through July, 2000. The conclusions were as follows; 1. Actual Condition of School Safety Accident 1) Approximately many teachers investigated had had an experience to suffer safety accident. Safety accident occurred most during break or class, but there was a significant difference according to service area. 2) Safety accident took place most in playground, and the most common cause was student's own carelessness, and the most widely occurred accident type was an injury. But there was no significant difference caused by the general characteristics of the teachers. 2. Influence of Safety Accident On Teacher's Educational Activities. 1) The largest reason they offered safety education was to ensure student safety. The greatest number of them had an opinion they would consider changing or giving up a planned normal educational activity if they recognized any possibilities of safety accident. There was a significant difference in this point according to gender and career. 2) They worried about possible safety accident most during field study, but there was a significant difference according to gender or presence or absence of safety accident experience. 3) The general characteristics of teacher produced a significant difference to an experience of avoiding educational activity due to psychological withdrawal, but safety accident experience didn't make any difference. 3. Minimization of Teacher Damage or Loss from Safety Accident. 1) The dominant opinion about teacher's small mistake for any occurrence of safety accident was that the responsibility should be escaped to maintain teacher's authority. For severe mistake, however, there were two different opinions at the same percentage: one was being exempted and the other was taking civil liability. 2) Establishing teacher insurance was preferred as a way to minimize teacher's economic loss from safety accident, but there was a significant difference according to gender. 3) The dominant opinion about the payment of insurance premium for safety accident was that it should be paid from school operating expenses.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.5
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• pp.99-112
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• 2020

This study empirically analyzed the relationship with major influencing factors in enhancing innovation capability of start-ups and their influence on innovation performance. If the existing innovation competency studies were analyzed from a general corporate perspective, In this study, it was analyzed from the perspective of start-up companies with less than 7 years of founding. As a result of a survey on startups, learning competency among the sub-variables of innovation competency, R&D competency and marketing competency are significant positive (+) consistent with both organizational competence related to organizational culture and organizational goals, technology commercialization competency, and close product competency. Has been shown to affect. The technical competence part does not have a significant effect on the product competency. However, it could not be interpreted that the importance of these competencies was low. This is because although technical competence did not directly affect product competency, it was analyzed as a meaningful result in relation to R&D competency. In addition, the characteristics of the company were classified into technology orientation and market orientation, and the relationship between each sub-variable was analyzed. The technical competence of a technology-oriented company did not have a significant effect on the product competency, but it was found that it had an effective effect on the R&D capacity. It is also consistent with the research findings that the initial survival rate is low as the characteristics of start-ups are often based on technology and ideas. Based on these results, There is a difference in major innovation capabilities according to the growth stage of a company. From a practical point of view, I would like to present approaches and implications for strengthening the competence of start-ups.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.2
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• pp.7-12
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• 2012

Recently the medical field to efficiently process the vast amounts of information to decision trees, neural networks, Bayesian Networks, including the application method of various data mining techniques are investigated. In addition, the basic personal information or patient history, family history, in addition to information such as MRI, HRCT images and additional information to collect and leverage in the diagnosis of disease, improved diagnostic accuracy is to promote a common status. But in real world situations that affect the results much because of the variable exists for a particular data mining techniques to obtain information through the enemy can be seen fairly limited. Medical images were taken as well as a minor can not give a positive impact on the diagnosis, but the proportion increased subjective judgments by the automated system is to deal with difficult issues. As a result of a complex reality, the situation is more advantageous to deal with the relative probability of the multivariate model based on Bayesian network, or TAN in the K2 search algorithm improves due to expansion model has been proposed. At this point, depending on the type of search algorithm applied significantly influenced the performance characteristics of the extended Bayesian network, the performance and suitability of each technique for evaluation of the facts is required. In this paper, we extend the Bayesian network for diagnosis of diseases using the same data were carried out, K2, TAN and changes in search algorithms such as classification accuracy was measured. In the 10-fold cross-validation experiment was performed to compare the performance evaluation based on the analysis and the onset of high-risk classification for patients with HRCT images could be possible to identify high-risk data.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.405-412
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• 2021

The objective of this study is to investigate the environmental impact of fine dust generated at the construction waste intermediate treatment plants, and to propose engineering data and measures to suppress the generation of fine dust to cope with the expected strengthened environmental regulations of the government. The following study conclusions are drawn. 1) T he maximum concentration of fine dust in the workplace was measured as 160㎍/m³ from the crushing operation followed by the point of waste unloading, where focused suppression plan of the fine dust generation is needed in the future. 2) Fine dust concentrations of 113㎍/m³ in wet road conditions and 50㎍/m³ in dry conditions were measured, indicating that fine dust could be reduced by 50% with watering alone. 3) The effect of distancing from the dust source was studied. PM10 during operation of the workplace was measured as about 25㎍/m³ higher than those of the neighboring areas. Whereas there was no significant difference in case of PM2.5 between workplace and neighboring areas. 4) The measurement results of the heavy metal contents showed that these metals did not affect neighboring areas.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.3
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• pp.76-92
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• 2018

This study aimed to establish database of rainfall inundation area by rainfall scenarios and conduct a real time prediction for urban flood mitigation. the data leaded model was developed for the mapping of inundated area with rainfall forecast data provided by korea meteorological agency. for the construction of data leaded model, 1d-2d modeling was applied to Gangnam area, where suffered from severe flooding event including september, 2010. 1d-2d analysis result agree with observed in term of flood depth. flood area and flood occurring report which maintained by NDMS(national disaster management system). The fitness ratio of the NDMS reporting point and 2D flood analysis results was revealed to be 69.5%. Flood forecast chart was created using pre-flooding database. It was analyzed to have 70.3% of fitness in case of flood forecast chart of 70mm, and 72.0% in case of 80mm flood forecast chart. Using the constructed pre-flood area database, it is possible to present flood forecast chart information with rainfall forecast, and it can be used to secure the leading time during flood predictions and warning.

• Management & Information Systems Review
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• v.36 no.4
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• pp.187-209
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• 2017

Service industry performance and competitive advantage depend on the attitudes and behavior of customer service employees who produce and deliver services through contact with customers. Most studies on customer service employees so far have concentrated on kindness, attitudes, or benefits. This study focuses on the increasing importance of customer service employees and intends to study them from the viewpoint of human brands that recognize customer service employees as a brand. In addition to the role of the employee at the service contact point, the customer participation behavior affects the interaction process with the customer service employee. Ultimately, customers could no longer be excluded from control to improve service quality. This study based on theory that the human brand characteristics of the customer service employees lead the customer's participation, which has a positive effect on the relationship with the service brand and the service brand attitude surveyed and analyzed customers who use service brand. This study is summarized as follows. First, the relationship between the service brand and the customer is examined. Second, this study also expands prior studies by examining the human brand characteristics of customer service employees and customers' willingness to participate in providing information on the impact of the consumer-brand relationship. The results of the study indicate that among the customer service employees' human brand characteristics reliability, familiarity, and empathy were found to affect the relationship between customers, the service brand, and the attitude toward the service brand the most. This study provides important implications for theoretical and practical strategies by examining the qualities and characteristics of customer service employees, which are the most important agents of marketing.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.143-149
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• 2014

Currently, despite the quantitative growth of domestic journal, objective and metric criterion to evaluate the contents and quality of those journals is inadequate. As a result, depending on a foreign citation index like SCI to evaluate the research result is causing some problems such as, thesis of an excellent standard being presented and published in foreign countries, thus, neglecting journals written in Korean. Hereat, the Korea Citation Index(KCI) is constructing a database of the journals published by academic associations; scientific paper information, articles information, and bibliographic, analyzing the quoting relation. Consequently, KCI is providing the basic information and the corresponding quoting relations of journals and papers on its webpage. This study compares the impact level of domestic accounting related journals by KCI and analyzes the network among journals using the cross-citation frequency from a social network analysis point of view. As a result, Accounting-related journals are now more desirable than the location in order to have a variety of interdisciplinary research needs to be encouraged. Through this exchange of other disciplines and actively made, which is the phase of apparent accounting-related journals expect to be greatly enhanced looks.

• The Journal of the Korea Contents Association
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• v.12 no.1
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• pp.91-102
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• 2012

Generally today's culture and the arts industry has been focusing more on economic value than the arts. Therefore this paper will elucidate the meaning of the culture and the arts can be a break though which can only include commercial and economic values but transcend its values ultimately. First of all, this paper will suggest an advanced 3D stereoscopic images by analysis of examples and environments of realistic media arts. Looking into the changes of related technologies and market environments, the motion-recognition technology, as seem in SF film "Minority report", has become a feasible technology. In the past, 3D stereoscopic images were shown in the theme park theatre and exhibition halls for group viewing. but recent 3D TV and display devices have changed those environments to personal. Since domestic researches of realistic media art has been little, this paper will analyze them respecting to three broad classifications. The results are : Firstly, in CAVE method, more impact capabilities of spectators are expected that they can manipulate interactive interfaces freely and the physical movements of spectators can operate interactively. Secondly, inter-network communications and expansion of viewers' perceptions are predicted by way of HMD method, sensor suites and communication equipments. Thirdly, combinations of HMD and motion tracking utilization is foreseen. With the convergent usages of these three features, we can prospect the possibilities of interactive 4D that spectators wearing 3D stereoscopic display devices can experience and make their own 3D stereoscopic images actively at the point of their views.