• Journal of Energy Engineering
• /
• v.13 no.1
• /
• pp.51-59
• /
• 2004

The NSSS (Nuclear Steam Supply System) thermal-hydraulic programs adopted in the domestic full-scope power plant simulators were provided in early 1980s by foreign vendors. Because of limited compulsational capability at that time, they usually used very simplified physical models for a real-time simulation of NSSS thermal-hydraulic transients, which entails inaccurate results and, thus, the possibility of so-called "negative training", especially for complicated two-phase flows in the reactor coolant system. In resolve the problem, KEPRI developed a realistic NSSS T/H program ARTS which was based on the RETRAN-3D code for the improvement of the Nuclear Power Plant full-scope simulator. The ARTS (based on the RETRAN-3D code) guarantees the real-time calculations of almost all transients and ensures the robustness of simulations. However, there is some possibility of failing to calculate in the case of large break loss of coolant accident (LBLOCA) and low-pressure low-flow transient. In this case, the backup calculation system cover automatically the ARTS. The backup calculation system was expected to provide substantially more accurate predictions in the analysis of the system transients involving LBLOCA. The results were reasonable in terms of accuracy, real-time simulation, robustness and education of operators, complying with FSAR and the AMSI/ANS-3.5-1998 simulator software performance criteria.

• The Journal of the Korea Contents Association
• /
• v.17 no.7
• /
• pp.113-123
• /
• 2017

This research is designed to review the systems thinking and STEAM theory while ascertaining the effects of the classroom application of the STEAM programs based on systems thinking appropriate for studying climate change. The systems thinking based STEAM program has been developed by researchers and experts, who had participated in expert meetings in a continued manner. The program was applied to science classes over the course of eight weeks. Therefore, the application effects of the systems thinking based STEAM program were analyzed in students' systems thinking, STEAM semantics survey, and students' academic achievement. The findings are as follows. First, the test group has shown a statistically meaningful difference in the systems thinking analysis compared to the control group in the four subcategories of 'Systems Analysis', 'Personal Mastery', 'Shared Vision' and 'Team Learning' except for 'Mental Model'. Second, in the pre- and post-knowledge tests, the independent sample t-test results in the areas of science, technology, engineering, art and mathematics show statistically meaningful differences compared to the control group. Third, in the academic performance test regarding climate change, the test group displayed higher achievement than the control group. In conclusion, the system-based STEAM program is considered appropriate to enhance amalgamative thinking skills based on systems thinking. In addition, the program is expected to improve creative thinking and problem-solving abilities by offering new ideas based on climate change science.

• Journal of the Korea Convergence Society
• /
• v.9 no.1
• /
• pp.21-29
• /
• 2018

The purpose of this study is to explore supporting strategies for teaching and learning based on students' effect recognition and continuous intention in college flipped learning. It was analyzed 426 data by multivariate analysis of variance (MANOVA) by examining student's effect recognition and continuous intention on 15 flipped learning classes of K-university in Chungnam. The characteristics of learners were male, senior students, students who knew flipped learning, students who did not have previous experience, and students who were learning video at anytime. As a teaching strategy, it was found that effect recognition and continuous intention were high in the supplementary deepening flipped learning class and natural science or engineering area. As a teaching and learning supporting strategies, First, the university should develop and operate flipped class learning strategy program for females and low-grade students. Second, it should support the development of good flipped learning design and operation model of instructor. Third, it should support the development of high quality online learning contents that students can learn from time to time. Fourth, it should support the strengthening of teaching competency to develop and operate flipped learning classes. This study can be used as basic data to support and spread the effective flipped learning classes of the university in the future.

• Industry Promotion Research
• /
• v.5 no.1
• /
• pp.47-52
• /
• 2020

In this study, parallel work-learning training, which was started in 2013 as a pre-employment promotion policy, is an important factor that determines the success or failure of training. As a time when various institutional supplementation is needed to encourage company participation, this study is to identify the factors of participation of companies participating in work-learning parallel. To this end, a questionnaire survey was conducted of companies participating in parallel work-learning in Chungnam, and the results were analyzed using the structural equation model. As a result of the study, the reason for the company's participation in parallel work-learning was firstly, 84% of government subsidy received education and training expenses. Second, 66% of workers were able to pay less than regular workers, and thirdly, it was easy to hire new employees in the field. 26%, 17% of them were invited by acquaintances for no particular reason. Therefore, the study suggests that participation in the work-learning parallel training contributes to the management costs, management of employee turnover, and human resource development. In future research, it is necessary to subdivide tests and estimates by conducting studies on regions, occupations, gender, wages, and years of service in Korea.

• Economic and Environmental Geology
• /
• v.28 no.4
• /
• pp.395-404
• /
• 1995

The geologic structure of the Cheju volcanic island has been investigated by analyzing the gravity and magnetic data. Bouguer gravity map shows apparent circular low anomalies at the central volacanic edifice, and the maximum difference of the anomaly values on the island appears to be 30 mgal. The subsurface structure of the island is modeled by three-dimensional depth inversion of gravity data by assuming the model consists of a stacked grid of rectangular prisms of volcanic rocks bounded below by basement rocks. The gravity modeling reveals that the interface between upper volvanic rocks and underlying basement warps downward under Mt. Halla with the maximum depth of 5 km. Magnetic data involve aeromagnetic and surface magnetic survey data. Both magnetic anomaly maps show characteristic features which resemble the typical pattern of total magnetic anomalies caused by a magnetic body magnetized in the direction of the geomagnetic field in the middle latitude region, though details of two maps are somewhat different. The reduced-to-pole magnetic anomaly maps reveal that main magnetic sources in the island are rift zones and the Halla volcanic edifice. The apparent magnetic boundaries inferred by the method of Cordell and Grauch (1985) are relatively well matched with known geologic boundaries such as that of Pyosunri basalt and Sihungri basalt which form the latest erupted masses. Inversion of aeromagnetic data was conducted with two variables: depth and susceptibility. The inversion results show high susceptibility bodies in rift zones along the long axis of the island, and at the central volcano. Depths to the basement are 1.5~3 km under the major axis, 1~1.5 km under the lava plateau and culminates at about 5 km under Mt. Halla. The prominent anomalies showing N-S trending appear in the eastern part of both gravity and magnetic maps. It is speculated that this trend may be associated with an undefined fault developed across the rift zones.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.10 no.4
• /
• pp.157-165
• /
• 2015

The purpose of this study is to suggest a successful operating strategy of co-working space. Therefore, the operating elements were identified through a literature research. And then, verified through site investigation and interview of operation managers. We found out that the high level operating elements are 'Co-working management', 'Membership management' and 'Supporting management' And the low level elements of Co-working management are 'Relationship facilitation', 'Networking event & Party' and 'Community & Communication', Membership management's are 'Service diversity & Price plan', 'Promotion & PR' and 'Alliance & Partnership', Supporting management's are 'Space & Interior', 'Facility & Device, Solution' and 'Mentoring & Education'. And the questionnaire was designed and conducted to Co-working space operators through the AHP method. As a result of the collected data analyzing, the highest priority was the operational element 'Community & Communication', and 'space and interior' is next, 'Service diversity & Price plan' is the third. The results were discussed with the relevant experts and it presents the following operating strategies. First, to create an environment suitable to voluntary coworking is the most important element. In particular, good management of 'Community & Communication' should be considered as a high priority operations strategy in a coworking space. Second, interior and space utilization helps in making the environment and atmosphere conducive to coworking. Office devices and facilities such as IT infra, printer, fax, scan, paper...etc are also important elements. But the reason why these necessary items are given a low priority is that these items don't need any special strategy. Third, in order to create a stable profit, 'Service diversity & Price plan' should be the characteristics of each coworking space because it will attract and secure enough customers. This study is valuable, it could be a great guideline for coworking space in an early stage to adopt operating model and strategy

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.3
• /
• pp.345-351
• /
• 2008

Fe-impregnated activated carbon(Fe-AC) was prepared by Fe(III) loading on activated carbon(AC) in various preparation pH. In order to evaluate the stability of Fe-AC, dissolution of iron from Fe-AC in acidic conditions was measured. In addition, batch experiments were conducted to monitor the removal efficiency of copper by Fe-AC. Results of stability test for Fe-AC showed that the amount of extracted iron increased with contact time but decreased with increasing solution pH. The dissolved amount of iron gradually increased at solution pH 2 and finally 13% of the total iron loaded on activated carbon was extracted after 12 hr. However dissolution of iron was negligible over solution pH 3. Removal of Cu(II) by Fe-AC was greatly affected by solution pH and was decreased as solution pH increased as well as initial Cu(II) concentration decreased. Surface complexation modeling was performed by considering inner-sphere complexation reaction and using the diffuse layer model with MINTEQA2 program.

• Journal of the Society of Disaster Information
• /
• v.20 no.1
• /
• pp.106-116
• /
• 2024

Purpose: This paper conducts IoT and CCTV-based safety monitoring to analyze accidents and potential risks occurring at construction sites, and detect and analyze risks such as falls and collisions or abnormalities and to establish a system for early warning using devices like a walkie-talkie and chatbot service. Method: A safety management service model is presented through smart construction technology case studies at the construction site and review a relevant literature analysis. Result: According to 'Construction Accident Statistics,' in 2021, there were 26,888 casualties in the construction industry, accounting for 26.3% of all reported accidents. Fatalities in construction-related accidents amounted to 417 individuals, representing 50.5% of all industrial accident-related deaths. This study suggests implementing AI chatbot services for construction site safety management utilizing IoT-based health monitoring technologies in smart construction practices. Construction sites where stakeholders such as workers participate were demonstrated by implementing an artificial intelligence chatbot system by selecting major risk areas within the workplace, such as scaffolding processes, openings, and access to hazardous machinery. Conclusion: The possibility of commercialization was confirmed by receiving more than 90 points in the satisfaction survey of participating workers regarding the empirical results of the artificial intelligence chatbot service at construction sites.