• Journal of the Korean Institute of Gas
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• v.28 no.3
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• pp.21-35
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• 2024

Due to climate change, energy sources that do not emit pollutants such as hydrogen, solar power, and wind power are attracting attention worldwide. In Korea, interest in hydrogen, an eco-friendly energy source, is increasing through the 'Roadmap to Revitalize the Hydrogen Economy' in 2019. In line with this, the supply of hydrogen is actively being promoted, so research related to the safe operation and risk management of hydrogen charging stations is needed. In this study, risk assessment was conducted using HyRAM+ and PHAST v8.7, which are risk assessment programs, based on the report value of the US National Laboratory Sandia National Laboratory (SNL). As a result, the Jet fire scenario conducted using HyRAM+ derived the greatest impact range of 40m in the tube trailer. As a result of Catastrophic rupture using PHAST v8.7, the greatest impact range of 1 psi in the tube trailer was derived with 240m. In addition, as a result of determining the location of the hydrogen charging station using ITALY's Land Use Planning (LUP), it was confirmed that the hydrogen charging station was an appropriate location as F area based on LUP.

• Journal of The Korean Association For Science Education
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• v.38 no.3
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• pp.319-329
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• 2018

Research Projects allow students to experience of scientific research by conducting experiments on specific scientific subjects and writing reports. The process of research begins as students find and propose research questions and its importance has been consistently emphasized. In this study, we developed various strategies to support students to draw research questions and applied to each phase. We analyzed how students' research questions were developed at different phases. The program consists of five phases, such as (1) Exploration, (2) Literature Review and Data Collection, (3) Modification and Extension, (4) Sharing and Evaluation, (5) Final Selection and Research Plan. The program was applied to high school Research Project for 12 hours. A total of 13 students were divided into four groups of 3-4 students and conducted researches. The results of each student's research process and final research plans were then collected and analyzed. The overall quality of research questions produced by the students showed improvement in each phase. Each strategy improved in various aspects of the research questions at each level. Students were able to find their own area of interest in the 'Exploration' phase and then they began to suggest verifiable plans in the 'Literature and Data Collection' phase. They were able to find a variety of variables under the 'Modification and Extension' phase, whereas the precision of research questions improved in the 'Sharing and Evaluation' and the 'Final Selection and Research Plan' phase.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6630-6638
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• 2014

The concerns for higher returns among investors in Korea are increasing as local interest rates lag behind the global market. The aim of this study was to provide a basis for estimating the precise return on investment to private investors and stakeholders of office buildings by identifying the optimal scale estimation of office building space, derived from managerial expenses. The literature on the economies theories of scales were reviewed, and the average administrative costs on an appropriate scale were assessed by cross-analysis and regression analysis using the U-shaped quadratic and cubic function. The findings suggest that the average office building managerial costs are approximately 6-11% according to the region, 10-13% according to the grade, and 8-9% according to size. Corporate-owned buildings represent the highest in terms of the average managerial costs, and there is an approximately 11.5% difference when it comes to outsourcing. In addition, the elapsed year showed that approximately 5.3 years to meet the lowest U-shaped curve of the average managerial cost. The 'Total floor area' variable shows a ${\bigcap}$-shape as it continue to increase to 72,000-Pyung then decrease gradually. This study presents the fundamental proposition of efficient and practical management of cost, lease and operation for real estate management firms by utilizing LCC.

• Journal of the Korean Regional Science Association
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• v.34 no.3
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• pp.3-11
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• 2018

Urban regeneration is a worldwide challenging project, showing a great interest in the sector. In order for Korea's urban regeneration to be settled successfully in the early stage, it is necessary to analyze and review the opinions and business performance of the urban regeneration areas. The purpose of this study is to evaluate the urban regeneration planning factors affecting urban regeneration on the satisfaction of citizens, public administration and region. This study surveyed the residents and experts of the Yeongju city, Gyeongsangbuk-do, where urban regeneration is actively doing with active participation of residents and local government. Based on the data of the survey, this paper performed frequency analysis, correlation analysis and multiple regression analysis as a analytic methods. The results revealed that 'community factor' was the most important factor to the satisfaction of residents in the urban regeneration project in progress. In the final stage(at present), both 'community factor' (0.387) and 'physical factor'(0.454) were found to have a significant effect on satisfaction. While the satisfaction from 'the economic factor'(0.111) has slowed but it has increased with 'the physical factors' in the process of regeneration project, 'the social factors'(-0.007) shows a downward trend. If the role of social factors and community factors are supported at the beginning step of the urban regeneration project, the physical factors and economic factors are continued to lead a sustainable urban regeneration in the long term.

• Journal of the Korean earth science society
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• v.29 no.6
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• pp.474-486
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• 2008

There has been an amounting interest and subjects in gifted education in recent years as a number of studies dealt with the development of gifted education programs. However, earth science area remained as a low profile in developing educational programs and materials that meet the varying curiosities and needs of gifted students with a focus on their characteristic development. This study developed a small group-based active-cooperative learning program in middle school to investigate the effects of the program in terms of the creative problem solving ability in science and learning attitude of the gifted students. Then the study examined the conceptions of the students after the implementation of the small group-based active-cooperative learning program. Findings of the study showed that there was a significant increase in participated gifted students' creative problem solving skills and their learning attitude. In addition, the small group-based active-cooperative learning program apparently increased the participants' interests, satisfaction, and participation toward the instruction, and significantly influenced their affective domain. It implies that these findings were not caused by the lectures from the teachers, but by the variety of activities in which the gifted students discussed and debated with the classmates to derive a positive reciprocal action. In conclusion, a small group-based active-cooperative learning program promoted a reciprocal action among all the students who participated in a small group by sharing their opinions and respecting each other.

• Journal of The Korean Association For Science Education
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• v.36 no.2
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• pp.253-267
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• 2016

Everybody dreams of a bright future. A future career determines the direction and quality of an individual's life. Achieving positive career development is one of the most crucial tasks during adolescence. In both national and personal perspectives, the vocational identity of science-gifted students provides some important points to discuss. The purpose of this study is to examine the vocational identity of science-gifted students. Participants included 103 science-gifted students who have received an acceptance letter from a science-gifted school. The modified VISA (Vocational Identity Status Assessment) model was used to analyze the vocational identities of gifted students with 'a letter to myself in the future'. The study found that vocational identity status of the science-gifted students was determined as Foreclosed and Searching Moratorium. The science-gifted students demonstrated more Commitment than Exploration and Reconsideration. They also showed higher levels in Career Identification, In-Narrow Exploration, and Career Flexibility. In addition, they shared common orientations in vocational identity such as strong enthusiasm, challenging limits, and responsibility towards humanity. We expect that this study will contribute to the social interest of science-gifted students in the area of career education. In order for science-gifted students to nurture their full potential with a deeper awareness of education, follow-up studies have to be conducted to provide greater and ideal career education.

• Journal of the Korean Vacuum Society
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• v.12 no.3
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• pp.168-173
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• 2003

Recently, according to the rapid progress in Flat-panel-display industry, there has been a growing interest in the poly-Si process. Compared with a-Si, poly-Si offers significantly high carrier mobility, so it has many advantages to high response rate in Thin Film Transistors (TFT's). We have investigated a new process for the high temperature Solid Phase Crystallization (SPC) of a-Si films without any damages on glass substrates using thin film heater. because the thin film heater annealing method is a very rapid thermal process, it has very low thermal budget compared to the conventional furnace annealing. therefore it has some characteristics such as selective area crystallization, high temperature annealing using glass substrates. A 500 $\AA$-thick a-Si film was crystallized by the heat transferred from the resistively heated thin film heaters through $SiO_2$ intermediate layer. a 1000 $\AA$-thick $TiSi_2$ thin film confined to have 15 $\textrm{mm}^{-1}$ length and various line width from 200 to 400 $\mu\textrm{m}$ was used as the thin film heater. By this method, we successfully crystallized 500 $\AA$-thick a-Si thin films at a high temperature estimated above $850^{\circ}C$ in a few seconds without any thermal deformation of g1ass substrates. These surprising results were due to the very small thermal budget of the thin film heaters and rapid thermal behavior such as fast heating and cooling. Moreover, we investigated the time dependency of the SPC of a-Si films by observing the crystallization phenomena at every 20 seconds during annealing process. We suggests the individual managements of nucleation and grain growth steps of poly-Si in SPC of a-Si with the precise control of annealing temperature. In conclusion, we show the SPC of a-Si by the thin film heaters and many advantages of the thin film heater annealing over other processes

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.245-253
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• 2011

Due to the imprudent spending of the fossil fuels, the environment was contaminated seriously and the exhaustion problems of the fossil fuels loomed large. Therefore people become taking a great interest in alternative energy resources which can solve problems of fossil fuels. The wind power energy is one of the most interested energy in the new and renewable energy. However, the plants of wind power energy and the traditional power plants should be balanced between the power generation and the power consumption. Therefore, we need analysis and prediction to generate power efficiently using wind energy. In this paper, we have performed a research to predict power generation patterns using the wind power data. Prediction approaches of datamining area can be used for building a prediction model. The research steps are as follows: 1) we performed preprocessing to handle the missing values and anomalous data. And we extracted the characteristic vector data. 2) The representative patterns were found by the MIA(Mean Index Adequacy) measure and the SOM(Self-Organizing Feature Map) clustering approach using the normalized dataset. We assigned the class labels to each data. 3) We built a new predicting model about the wind power generation with classification approach. In this experiment, we built a forecasting model to predict wind power generation patterns using the decision tree.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.391-397
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• 2017

Recently, digital image correlation (DIC) techniques have been used to measure dynamic deformation during tensile testing. The standard tensile test method measures the average displacement of the relevant specimen to calculate the true stress-strain curve. Therefore, the validity of the true stress curve is restricted to the stress incurred within the uniform stretching interval, i.e., the maximum stress corresponds to the starting point of the necking deformation. Alternatively, if DIC is used, the effective range of the strain and strain rate can be extended to the breaking point of the tensile specimen, because of the feasibility of measuring the local strain over the entire area of interest. Because of these advantages, many optical 3D measurement systems have been introduced and used in research and industry. However, the conventional 3D measurement systems are exceedingly expensive and time consuming. In addition, these systems have the disadvantage of a very large equipment size which makes their transport difficult. In this study, a 2D image correction method employing a 2D DIC measurement method in conjunction with a numerical analysis method is developed using a smartphone. The results of the proposed modified 2D DIC method yielded higher accuracy than that obtained via the 3D measurement equipment. In conclusion, it was demonstrated that the proposed 2D DIC and calibration methods yield accurate measurement results with low time costs.

• Current Research on Agriculture and Life Sciences
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• v.32 no.3
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• pp.111-117
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• 2014

Phytophthora blight caused by Phytophthora capsici Leonian is a dangerous disease threatening pepper growers worldwide. The efficacy of chemical control is generally low as the pathogen is soil-borne and rapidly spread by zoospores during the rainy season. Thus, based on the demand for resistant varieties, various good resistant sources, such as CM334, AC2258, and PI201234, have been reported and their inheritance of resistance studied by many different authorities. However, the mode of inheritance remains unclear, as 1 or 2 independent dominant genes, 3 genes, or multiple genes have all been reported as responsible for resistance. Recently, QTL mappings of the gene factors for resistance have been reported, and molecular markers for resistance used in breeding programs. With the release of many resistant commercial hybrid cultivars, differentiation of pathotypes of the pathogen is attracting interest among breeders and plant pathologists. Various authorities have already classified the pathogen strains into different races according to the inter-action between resistant host plants, including the source of resistance, such as CM334 and PI201234, and resistant commercial varieties and P. capsici isolates. However, no standard differential host sets have yet been established, so the results are good only for the pathogen strains used in the experiments. Thus, for breeding varieties with durable resist-ance, it is important to introduce resistance from different sources and use diverse local pathogen strains collected in the target area for distribution in a breeding program.