• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.1
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• pp.63-72
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• 2020

The purpose of this study is to investigate the effects of the application of various numerical models and frequency contents of earthquakes on the performances of the reactor containment building (RCB) in a nuclear power plant (NPP) equipped with an advanced power reactor 1400. Two kinds of numerical models are developed to perform time-history analyses: a lumped-mass stick model (LMSM) and a full three-dimensional finite element model (3D FEM). The LMSM is constructed in SAP2000 using conventional beam elements with concentrated masses, whereas the 3D FEM is built in ANSYS using solid elements. Two groups of ground motions considering low- and high-frequency contents are applied in time-history analyses. The low-frequency motions are created by matching their response spectra with the Nuclear Regulatory Commission 1.60 design spectrum, whereas the high-frequency motions are artificially generated with a high-frequency range from 10Hz to 100Hz. Seismic responses are measured in terms of floor response spectra (FRS) at the various elevations of the RCB. The numerical results show that the FRS of the structure under low-frequency motions for two numerical models are highly matched. However, under high-frequency motions, the FRS obtained by the LMSM at a high natural frequency range are significantly different from those of the 3D FEM, and the largest difference is found at the lower elevation of the RCB. By assuming that the 3D FEM approximates responses of the structure accurately, it can be concluded that the LMSM produces a moderate discrepancy at the high-frequency range of the FRS of the RCB.

• Journal of Science Education
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• v.32 no.2
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• pp.1-16
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• 2008

The purpose of this study was to analyze about STS contents in the next generation science textbook for 10th grade according to curriculum revision 2007 and high school science textbooks focused on the Earth Science which were published according to the 7th curriculum. The contents of STS were analyzed by the STS topics of Yager(1989), Piel's standard(1981), and student activities by SATIS. The results of this study are the same as follows: 'The next generation science textbook' was shown that 20.9% is STS material amount in average by Yager's standard. 'High school science textbooks' were shown that 11.3% is STS material amount in average. Based on the STS topics by Yager's standard, most of STS content is focused on 'Relativity with local community', 'Application of science' and 'Cooperative work on real problems'. However, there is rare contents such as 'Multiple dimensions of science', 'Practice with decision-making strategies' and 'Evaluation concerned for getting and using information' in the next generation science textbook. In high school science textbooks were shown that 'Applicability of science' is the highest and 'Relativity with local community' is the next high contents. Based on the STS topics by Piel's standard, most of STS contents are focused on 'Environmental quality', 'Space research' and 'National defence' in the next generation science textbook. But high school science textbooks are focused on 'Natural resources' and 'Technology development'. The activities were analyzed by SATIS student activities. The major categories of activities included in the next generation science textbook were 'Investigation', 'Simulation' and 'Data analysis'. But, there were rare activities like 'Roleplaying', 'Research design' and 'Simulation' in high school science textbooks.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.3
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• pp.147-154
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• 2011

Decision making in Environmental Impact Assessment (EIA) and Consultation on the Coastal Area Utilization (CCAU) is footing on the survey reports, thus requires concrete and accurate information on the natural habitats. In spite of the importance of reporting the ecological quality and status of habitats, the accumulated knowledge and recent techniques in ecology such as the use of investigated cases and indicators/indices have not been utilized in evaluation processes. Even the EIA report does not contain sufficient information required in a decision making process for conservation and development. In addition, for CCAU, sampling efforts were so limited that only two or a few stations were set in most study cases. This hampers transferring key ecological information to both specialist review and decision making processes. Hence, setting the effective number of sampling stations can be said as a prior step for better assessment. We introduced a few statistical techniques to determine the number of sampling stations in macrobenthos surveys. However, the application of the techniques requires a preliminary study that cannot be performed under the current assessment frame. An analysis of the spatial configuration of sampling stations from 19 previous studies was carried out as an alternative approach, based on the assumption that those configurations reported in scientific journal contribute to successful understanding of the ecological phenomena. The distance between stations and number of sampling stations in a $4{\times}4$ km unit area were calculated, and the medians of each parameter were 2.3 km, and 3, respectively. For each study, approximated survey area (ASA, $km^2$) was obtained by using the number of sampling stations in a unit area (NSSU) and total number of sampling stations (TNSS). To predict either appropriate ASA or NSSU/TNSS, we found and suggested statistically significant functional relationship among ASA, survey purpose and NSSU. This empirical approach will contribute to increasing sampling effort in a field survey and communicating with reasonable data and information in EIA and CCAU.

• Journal of Technology Innovation
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• v.25 no.2
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• pp.89-125
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• 2017

Complex product systems (CoPs) is a engineering-intensive products with high-ended design technology, which are closely linked with national economic growth and development of social infrastructures. Accordingly, in order to understand the technological evolution of CoPs, it is necessary to identify the macro-environmental drivers surrounding the CoPs and their impact on the technological evolution of the CoPS. Therefore, we investigate the effect of policy, economic and social drivers on the technological evolution of CoPS by implementing the longitudinal case study on nuclear power plant during the periods between 1950 and 2010s. Based on the analysis of various sources of secondary data and primary data through interviews, we found that the technological evolution of nuclear power plant is progressed as "Phase 1: Application research for peaceful utilization of nuclear energy" between 1950s and 1960s, "Phase 2: The first renaissance of nuclear energy" during 1970s, "Phase 3: Enhancement of safety and the catch-up of latecomers in nuclear energy" between 1990s and 2000s, and "Phase 4: Top prioritization of safety and the development of next generation reactors for the second renaissance of nuclear energy" since 2010s. We also found that various kinds of policy, economic and social drivers, such as energy policy, investment in technology development, economic growth and energy demand, social acceptability and environmental concern, have affected the technology evolution of nuclear power plant at each phase. We emphasize the role of macroenvironmental drivers in the technological evolution of CoPS. We also suggest that countries that endeavor to develop CoPs need to utilize those drivers for enhancing competitiveness and sustaining leadership.

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.39-53
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• 2007

Generally, fractured medium can be described with some key parameters, such as hydraulic conductivities or random field of hydraulic conductivities (continuum model), spatial and statistical distribution of permeable fractures (discrete fracture network model). Investigating the practical applicability of the well-known conceptual models for the description of groundwater flow in fractured media, various types of hydraulic tests were applied to studies on the highly fractured media in Geumsan, Korea. Results from single-hole packer test show that the horizontal hydraulic conductivities in the permeable media are between $7.67{\times}10^{-10}{\sim}3.16{\times}10^{-6}$ m/sec, with $7.70{\times}10^{-7}$ m/sec arithmetic mean and $2.16{\times}10^{-7}$ m/sec geometric mean. Total number of test interval is 110 at 8 holes. The number of completely impermeable interval is 9, and the low permeable interval - below $1.0{\times}10^{-8}$ m/sec is 14. In other words, most of test intervals are permeable. The vertical distribution of hydraulic conductivities shows apparently the good correlation with the results of flowmeter test. But the results from the cross-hole test show some different features. The results from the cross-hole test are highly related to the connectivity and/or the binary properties of fractured media; permeable and impermeable. From the viewpoint of the connection, the application of the general stochastic approach with a single continuum model may not be appropriate even in the moderately or highly permeable fractured medium. Then, further studies on the investigation method and the analysis procedures should be required for the reasonable and practical design of the conceptual model, with which the binary properties, including permeable/impermeable features, can be described.

• Journal of The Korean Association For Science Education
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• v.39 no.5
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• pp.573-584
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• 2019

It is necessary to look at the essence of STEAM education from the viewpoint of the teacher who is the subject of education execution. We carry out questionnaires and telephone interviews for the purpose, definition, change, etc. of STEAM education from eight elementary, middle, and high teachers who are rich in policy and field application experience. As a result of the analysis, the purpose of the STEAM education that the specialists mentioned includes the active participation of the students. Most experts pointed out that the definition of STEAM education is ambiguous. So, it is necessary to express a clear goal of STEAM education. The category and level meaning "fields" from "a convergence of two or more fields" are not indicative definitions, but can be different depending on the situation, considering the context of activities and the level of students. The perception of the experts on framework may be a guide for STEAM education and stumbling block. It is necessary for "Context" to shift away from the emphasis on the real life connection and to the emphasis on the interest of the student and the guidance of the class. "Creative design" must be based on trial and error in the process of solving problems. "Emotional touch" needs to correct elements that cannot be observed, evaluated, and applied to lessons that are elements of emotional experience. As for the expansion of STEAM education, most expert teachers have recognized that STEAM education is becoming increasingly stable and that policy change has continued to slow the pace of stabilization.

• Asia pacific journal of information systems
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• v.21 no.1
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• pp.81-101
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• 2011

In today's rapidly changing and increasingly competitive business environment, new product development in tune with market trends in a timely manner has been a matter of the utmost concern for all enterprises. Indeed, developing a sustainable new business has been a top priority for not only business enterprises, but also for the government policy makers accountable for the health of Its national economy as well as for decision makers in what type of organizations. Further, for a soft landing of new businesses, building a government-initiated industry base has been claimed to be necessary as a way to effectively boost corporate activities. However, the existing methodology in new service and new product development is not suitable for nurturing industry, because it is mainly focused on the research and development of corporate business activities instead of new product development. The approach for developing new business is based on 'innovation' and 'convergence.' Yet, the convergence among technologies, supplies, businesses and industries is believed to be more effective than innovation alone as a way to gain momentum. Therefore, it has become more important than ever to study a new methodology based on convergence in industrial quality new product development (NPD) and new service development (NDS). In this research, therefore, we reviewed any restrictions in the existing new product and new service development methodology and the existing business model development methodology. In doing so, we conducted industry standard collaboration analysis on a new service model development methodology in the private sector and the public sector. This approach is fundamentally different from the existing one in that ours focuses on new business development under private management. The suggested framework can be categorized into industry level and service level. First, in the industry level, we define new business opportunities In occurrence of convergence between businesses. For this, we analyze the existing industry at the industry level to identify the opportunities in a market and its business attractiveness, based on which the convergence industry is formulated. Also, through the analysis of environment and market opportunity at the industry level. we can trace how different industries are lined to one another so as to extend the result of the study to develop better insights into industry expansion and new industry emergence. After then, in the service level, we elicit the service for the defined new business, which is composed of private service and supporting service for nurturing industry. Private service includes 3steps: plan-design-do; supporting service for nurturing industry has 4 steps: selection-make environment- business preparation-do and see. The existing methodology focuses on mainly securing business competitiveness, building a business model for success, and offering new services based on the core competence of companies. This suggested methodology, on other hand, suggests the necessity of service development, when new business opportunities arise, in relation to the opportunity analysis of supporting service based on the clear understanding of new business supporting infrastructure optimization. Meanwhile, we have performed case studies on the printing and publishing field with the restrict procedure and development system to assure the feasibility and practical application. Even though the printing and publishing industry is considered a typical knowledge convergence industry, it is also known as a low-demand and low-value industry in Korea. For this reason, we apply the new methodology and suggest the direction and the possibility of how the printing and publishing industry can be transformed as a core dynamic force for new growth. Then, we suggest the base composition service for industry promotion(public) and business opportunities for private's profitability(private).

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.6
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• pp.126-133
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• 2009

This study aimed to propose the base data to promote the green belt(thereafter GB) regulations and management in Korea. The research took the methods of analysis of citizen's official petitions to the once, of interviews and questionnaire to the of officials of Seoul Metropolitan City who is under the job of managing the GB. The conclusions were as follows. The officials did understand function and necessity of GB well. They especially, put the importance of the purpose of GB on the prevention of the environment of the city and prevention of concentration of population, They recognized that they suffered from the overloaded job on the management of GB in quantity and quality. The seriousness of illegal action of the change of land use, piling-up of materials and productions on the forbidden land, using exclusively of warehouses for agriculture as for commerce and enlarging the area of warehouse with application of leased land for agriculture instead of the agricultural land in law were detected in the officials' cognition. The officials proposed some ideas to prevent above mentioned illegal actions including forcing a person who did illegal actions to punish money to restore environment etc..

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.4
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• pp.412-429
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• 2008

As the amount of electronic documents increases rapidly with the growth of the Internet, a parallel search engine capable of handling a large number of documents are becoming ever important. To implement a parallel search engine, we need to partition the inverted index and search through the partitioned index in parallel. There are two methods of partitioning the inverted index: 1) document-identifier based partitioning and 2) keyword-identifier based partitioning. However, each method alone has the following drawbacks. The former is convenient in inserting documents and has high throughput, but has poor performance for top h query processing. The latter has good performance for top-k query processing, but is inconvenient in inserting documents and has low throughput. In this paper, we propose a hybrid partitioning method to compensate for the drawback of each method. We design and implement a parallel search engine that supports the hybrid partitioning method using the Odysseus DBMS tightly coupled with information retrieval capability. We first introduce the architecture of the parallel search engine-Odysseus/parallel-OOSQL. We then show the effectiveness of the proposed system through systematic experiments. The experimental results show that the query processing time of the document-identifier based partitioning method is approximately inversely proportional to the number of blocks in the partition of the inverted index. The results also show that the keyword-identifier based partitioning method has good performance in top-k query processing. The proposed parallel search engine can be optimized for performance by customizing the methods of partitioning the inverted index according to the application environment. The Odysseus/parallel OOSQL parallel search engine is capable of indexing, storing, and querying 100 million web documents per node or tens of billions of web documents for the entire system.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.3
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• pp.464-471
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• 2002

Author applied several engineering methodologies to classical ultrasonic nebulizer to cope with it's demerits. After several trials and errors, we got the several meaningful results. To evaluate the modified ultrasonic nebulizer for inhalation toxicology of cadmium, author used light-scattering photometer. This paper is the one part of inhalation exposure systems for inhalation toxicology study of cadmium. According to the testing conditions, source temperature 50℃ and inlet-duct band temperature 150℃, aerosol generation results for sodium chloride and cadmium chloride were as followings: Coefficients of variation(CV) of sodium chloride and cadmium chloride for repeated trials were 3.38 and 4.77 for 10g, 2.47 and 5.02 for 5g, and 4.70 and 2.98 for 2.5g. All the CVs were within 10% of acceptance variability. Count Per Minute(CPM) changes of NaCl and CdCl₂ for 5 repeated trials were similar. CPM ratios of CdCl₂/NaCl were 1.13 for 10g, 0.76 for 5g, and 1.06 for 2.5g. Relative aerosol generation of cadmium chloride to sodium chloride was the highest in 10g. Efficiency increases of 24.50% for 5g NaCl, 14.91 % for 2.5g NaCl, and 16.48% for 2.5g CdCl₂ with respect to theoretical efficiency were observed but 0.04% efficiency decrease was observed in 5g CdC₂. According to the modifications of source temperature(20, 50, 70℃) and inlet-duct band temperature(20, 50, 100, 150, 200℃), aerosol generation results for NaCl and CdCl₂ were as followings: CPM trends for each quantity excepting 10g NaCl in inlet-duct band temperature 200℃ were similar, and the highest CPM was observed in source temperature 70℃ to each inlet-duct band temperature. The highest CPMs to 10, 5, and 2.5g NaCl were observed in source temperature 70℃ and inlet-duct band temperature 20℃. Aerosol generation of cadmium chloride was increased with the higher source temperature, excepting inlet-duct band temperature 200℃. The highest CPMs for 10, 5, and 2.5g CdCl₂ were observed in source temperature 70℃ and inlet-duct band temperature 20℃, and this trend was similar to NaCl aerosol generation The highest CPMs for 10, 5, and 2.5g CdCl₂ were observed in source temperature 70℃ and inlet-duct band temperature 20℃, and this result was similar to NaCl aerosol generation. Observed efficiencies of 5 and 2.5g NaCl were similar to ifs theoretical efficiency but -3.08% efficiency decrease of 5g CdCl₂, 17.47% efficiency increase of 2.5g CdCl₂ were observed. CPM ratio of CdCl₂/NaCl of 10g was different to 5 and 2.5g, and 2.5g ratio was higher than 5g ratio. In conclusion, to get maximum aerosol generation for NaCl and CdCl₂ will be the conditions that set the appropriate inlet-duct band temperature for each materials and increase the source temperature. Sodium chloride can be used to evaluate the performance and predict the concentration for cadmium aerosol in aerosol generator and inhalation exposure system.