• International Journal of Highway Engineering
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• v.17 no.2
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• pp.143-150
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• 2015

PURPOSES : The authors set out to estimate the related carbon emissions, energy use, and costs of the national freeways and highways in Korea. To achieve this goal, a macro-level methodology for estimating those amounts by road type, road structure type, and road life cycle was developed. METHODS : The carbon emissions, energy use, and costs associated with roads vary according to the road type, road structure type, and road life cycle. Therefore, in this study, the road type, road structure type, and road life cycle were classified into two or three categories based on criteria determined by the authors. The unit amounts of carbon emissions and energy use per unit road length by classification were estimated using data gathered from actual road samples. The unit amounts of cost per unit road length by classification were acquired from the standard cost values provided in the 2013 road business manual. The total carbon emissions, energy use, and cost of the national freeways and highways were calculated by multiplying the road length by the corresponding unit amounts. RESULTS: The total carbon emissions, energy use, and costs associated with the national freeways and highways in Korea were estimated by applying the estimated unit amounts and the developed method. CONCLUSIONS: The developed method can be employed in the road planning and design stage when decision makers need to consider the impact of road construction from an environmental and economic point of view.

• Industrial Engineering and Management Systems
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• v.8 no.3
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• pp.162-170
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• 2009

This paper deals with a closed-loop remanufacturing system with one manufacturer and one remanufacturer. The manufacturer sells new products bearing the 'Extended Producer Responsibility (EPR).' It is assumed that the manufacturer's collection rate of used products depends only on the buy-back cost, while that of the remanufacturer depends on the minimum allowed quality level of used products in addition to the buy-back cost. Through the development of mathematical models with the objective function of maximizing profit, we study an efficient operation policy of each party. The decision variables are the unit selling price of new products and remanufactured products, the unit buy-back cost of the used products of the manufacturer and remanufacturer, and the minimum allowed quality level. The validity of the model is examined through numerical examples and sensitivity analysis.

• The KSFM Journal of Fluid Machinery
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• v.13 no.3
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• pp.24-29
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• 2010

Axial fans for an air-conditioning unit are designed to equip the system with an expected flow-rate and low noise level by applying the blade design method of multi-sectioning and local camber generation. In this study, the distributions of chord length, stagger angle, and camber angle are globally and locally determined for the given specific speed, which is considered to be relatively high. The mock-up fans are observed to satisfy the aerodynamic performance and the noise level for the system simultaneously and discussed in terms of local flow patterns related to the emitted noise.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.784-786
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• 1997

In this Paper, the effective method of determining the water discharge of a pondage hydro-unit for hydro dispatch is proposed. The water discharge of a pondage hydro-unit can be determined subtracting the spillage discharge from summation of the inflow and the pondage according to variation of the water level of the reservoir. Proposed method calculates the inflow using the duration curve, the water level from initial level on January 1, and the spillage discharge from the water discharge.

• Journal of The Korean Association For Science Education
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• v.17 no.1
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• pp.21-29
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• 1997

Many middle school students have difficulty in understanding biological concepts because too many concepts are presented in the textbook compared to limited school hours. So, it is necessary to select concepts which are indispensable. The purpose of this study is to select key concepts in the unit 'The Continuity of Life' by surveying students' and teachers' cognition on the concepts. In this study, 78 concepts were extracted from 'Science 3', unit II 'The Continuity of Life'. To survey how students and teachers think the concepts, Likert type questionnaires were made. 300 third grade middle school students and 34 biology teachers were selected by random sampling and the questionnaires were applied. The following results were obtained:1. Students thought 59 concepts out of 78 were important and the mean score of important level of the concepts was 3.60. Students thought 26 concepts out of 78 were difficult and the mean score of diffculty level'of the concepts was 3.26. The more they think the concepts important, the more they think them difficult (r=0.7462, p<0.001). 2. Teachers thought 55 concepts out of 78 were important and the mean score of important level of the concepts was 3.82. Teachers thought 33 concepts out of 78 were difficult and the mean score of diffculty level of the concepts was 3.31. The more they think the concepts important, the more they think them difficult (r=0.6138, p<0.001). 3. The selected concepts were considered more important by teachers than by students(t=2.0150, p<0.05). However, there was no significant difference in evaluating the difficulty level of the concepts(t=0.7327, p>0.05). 4. It was found that students have difficulty in understanding concepts when they are presented in the textbook to require formal preparation than concrete preperation(t=2.6612, p<0.05).

• Journal of Korean Society of Water and Wastewater
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• v.31 no.5
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• pp.447-457
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• 2017

This study derived the unit of industrial water usage reflecting the latest industry trends. Available for establishing plans such as the master plan for water supply system and analyzed changes in the basic unit by a comparison with the current basic unit values. This study analyzed 4,038 samples with a sampling error of less than 1.5 % at the 95 % confidence level after removing outliers according to a log-normal distribution. As a result, the unit of industrial water usage per site area in the whole manufacturing industry was 7.11 m3/1,000m2/d. The ten industrial categories (C10, C13, C20, C21, C22, C25, C27, C30, C32, C33) showed a similar unit value compared to before, and the four industrials categories (C11, C17, C22, C31) showed a more unit value than before. With regard to the nine industrial categories (C14, C15, C16, C18, C19, C24, C26, C28, C29), the unit value decreased. Cases that companies examined before were the same as the companies examined in this study were analyzed. The result that the changes in the unit industrial water usage were reasonable was obtained. However, in some industrial categories (C17, C14, C24, C29), the unit value was changed by a small number of companies with large-scale water use or unit value of sampling had a large deviation. It was considered necessary to survey them periodically. The unit of industrial water usage derived by the survey in this study reflects the current industrial trends in 2016. Water use in manufacturing companies has continuously changed by the development of manufacturing technologies and simplification of manufacturing processes. In order to deal with this, it is considered necessary to survey the usage of industrial water periodically from a long-term perspective.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.4
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• pp.27-47
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• 2022

The purpose of the study is to develop a unit catalog system that can be linked with the curriculum. As for the research method, first, unit subject words were extracted through the analysis of middle school curriculum and science textbooks in all grades. Based on this, we designed a unit catalog system that has a unit book catalog by connecting books related to the unit topic of the subject, an index word catalog that organizes unit subject words into index words, and a grade and school level linked subject linked to the unit topic as a subsystem. Using the Notion program, a unit catalog system was implemented on the web using a middle school science unit 1 as a sample. To evaluate the system, experiments and surveys were conducted targeting students, and very positive results were shown in terms of satisfaction with the system and intention to use it in the future. Meanwhile, this study was limited to middle school science departments, but it was proposed to expand the application to all grades and subjects.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.15 no.4
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• pp.531-538
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• 2008

Purpose: The purpose of this study was to identify factors influencing Vancomycin-resistant enterococcus infection control among nurses in intensive care units. Method: Data were collected from August 15 to October 14, 2007 from 188 nurses working in intensive care units. The nurses answered a 26 item-questionnaire, which included management of the cohort (14 items), hand washing (6 items) and management of the environment (6 items). Descriptive statistics, t or F test, ANOVA, and multiple regression analysis were used with SPSS PC+ 14.0 to analyze the data. Results: The participant's level of awareness of Vancomycin-resistant enterococcus infection control was 3.87; that of compliance was 3.74. Significant factors influencing the level of compliance with Vancomycin-resistant enterococcus infection control were'the level of the awareness' and 'the type of intensive care unit'. These two variables accounted for 21.0% of variance for compliance with the Vancomycin-resistant enterococcus infection control among the participants. Conclusion: In order to develop a strategy to increase the compliance with Vancomycin-resistant enterococcus infection control, it is necessary to be concerned about 'the level of the awareness', 'the type of intensive care unit;', and 'experiences of caring for patients with Vancomycin-resistant enterococcus'.

• Journal of Korean Society of Rural Planning
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• v.16 no.3
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• pp.27-41
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• 2010

This study developed a settlement environment diagnostic indices (SEDI) of rural villages which can apply to analyze variable conditions of villages having development projects. The index consists of 5 diagnostic areas (first level) with 13 items (second level), including detail indices of 40 criteria (third level) defined by specialists' brainstorming process. In order to develop the index system, object-oriented approach was used to extract the 5 diagnostic areas (infra-basic settlement facility, life condition & environmental resources, industry & economic infrastructure, community, and residents) from rural villages. For the 40 criteria, it was introduced a quantification method that all villages have absolute values in national level, not relative value between villages within an unit area. The diagnostic diagram and table were developed to evaluate the villages compositively. The developed SEDI was applied to study areas, 56 villages in 2 subdivision areas of county, located on county of Keumsan. Applicability of the index system, database system should be developed with the surveying method of data in village level.

• Journal of Korean Society for Quality Management
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• v.43 no.1
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• pp.31-42
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• 2015

Purpose: System consists of a lot of units with coherent function. In design phase, various units could be considered with the same function. In this study, we consider the alternative units with the same function and redundancy allocation to maximize system reliability in multi level system. Methods: The redundancy allocation problem with the alternative units in multi level system is formulated. Memetic algorithm(MA) is proposed to optimize the redundancy allocation problem. In addition, the performance of the proposed algorithm is explained by a numerical experiment. Results: MA showed better results than genetic algorithm(GA) and the convergence of the solutions in MA was also faster than GA. In addition, we could know from experiment that system reliability is increased and the chosen unit for redundancy allocation is changed if cost limit is increased. Conclusion: The chose unit for redundancy allocation is changed as resource constraints. It means we need to consider the alternative units in system design. In the future, we need to consider various problem related to redundancy allocation in multi level system and develop the better method to enhance search performance.