• Journal of the Korean Solar Energy Society
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• v.31 no.6
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• pp.103-110
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• 2011

The aim of this study was to analysis the Heating/cooling performance and Daylighting performance of Solar Window System built in apartments. the solar window is the idea to integrate daylight as a third form of solar energy into a PV/Solar Collector system. The process of this study is as follows: 1)Solar Window system was designed through the investigation of previous paper and work. 2)The simulation program(Lightscape3.2) was used in daylighting performance analysis. the reference model of simulation was made up to analysis daylighting performance on Solar Window system. 3)The simulation program(ESP-r, Therm5.0, Window6.0) was used in energy performance analysis. the reference model of simulation was made up to analysis energy and daylighting performance on Solar Window system. 4)The Size of Simulation model for daylighting and heating/cooling energy analysis was $148.5m^2$ 5)The lighting performance analysis was carried out with various variants, such as the size and installed area of Solar Window system. 6)Energy performance simulation was carried out with various variants, such as Integrated U-value of Solar Window system according to its position, installed angle and insulation thickness. Consequently, When Solar Window system is equipped with balcony window of Apartment, Annual heating and cooling energy of reference model was cut down at the average of $4.1kWh/m^2$ or 4.2%.

• Journal of The Korean Association For Science Education
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• v.4 no.2
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• pp.64-73
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• 1984

This study aimed at identifying the characteristics of current science curriculum in several countries in terms of its format, aims and objectives, contents and guidelines and discussed about therm. The curricula were collected from 9 countries- The United States of America(5 states), Canada(4 Provinces), England, West Germany, France, Australia, Newzealand, Japan and the republic of China. Each country had her own characteristics of science curriculum, but there also common characteristics among several countries. First, the format of science curricula in eastern countries were very different from those of western countries. The western countries had the curriculum format which included characteristics and needs of science education, philosophy and background, aims and objectives, contents, characteristics of learners, teaching and learning strategy, teaching materials, guide of experiments, evaluation methods, and other concrete informations while eastern countries had the curriculum format which included only objectives, contents and guidelines. I think that the format of science curriculum in western countries is more recommendable than that of eastern countries. Second, the aims and objectives of science curricula in eastern countries focused on scientific knowledges and concepts, while those of countries emphasized scientific methods and attitudes. Third, the contents of science curricula were very similar regardless of eastern countries or western countries. In other words, all the countries in this study emphasized life science and earth science at lower grade level and physical science at upper grade level. Especially the observation and concrete learning activities were suggested at lower grade level and logical reasoning was emphasized at upper grade level. I think that the integrated (topic-centered) science curriculum is more recommendable than our current non-integrated science curriculum in lower grade levels. Finally, the guidelines of science curriculum in eastern countries did not suggest specific information about teaching contents, experimental methods, teaching-learning activities, evaluation methods, teaching and learning meterals, while those of western countries provided more specific information which teachers could utilize very effectively.

• School Mathematics
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• v.18 no.3
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• pp.611-623
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• 2016

This study explored the problems of definitions and choices of terms and notations and proposed a few tasks for improvement of them included , , of high school mathematics based on 2009 revised mathematics curriculum and textbooks. We explored the problems on the features of the methods and contents of definitions of terms and notations in the viewpoint of the possibilities of difficulties on students' understanding, and proposed several criteria for choices of terms and notations in curriculum. And we proposed several tasks to improve the problems as follows: we need to implement much analyses and discussions on terms and notations and to open the results, to make the criteria for the examinations of mathematics textbooks in the viewpoint of therm and notation, to consider the differences of the methods of definitions among primary, middle, and high schools, and to consider the changes of terms and notations and the methods for introduction of them in textbooks.

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.47-52
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• 2011

Currently, Exterior wall's U-value about building envelope is 0.36 W/$m^2K$(Central Region), but window's one is 2.1 W/$m^2K$ according to air gap of glazing, filling gas, coating and type of windows. The door"s one is 1.6~5.5 W/$m^2{\cdot}K$ depending on material and configuration of door. As such, energy loss per unit of door is considerably larger like windows. The door for the recognition was relatively low because energy loss through the door is relatively small compared to window area. In this paper, thermal performance was analyzed through simulation targeting the door which has thermal break that can improve the insulation performance and doesn't have one. As a results of simulations, case1 was calculated as the average of 1.63 w/m2k and case 2 was calculated as the average of 4.14 w/m2k. The thermal performance of door depends on the type and condition of insulations. As a results of final simulations, Case1 was calculated as 1.06 w/m2k and Case2 was calculated as 1.27 w/m2k. As a results of the experiments, thermal performance of case 1 was measured as 1.28 w/m2k. Error between experiments and simulations is considered problems encountered when creating the samples. The effect of door frame on the overall thermal performance is slight because it's a small proportion of the door frame.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.1-10
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• 2022

Recently, semiconductor devices have been used in many fields owing to various applications of mobile electronics, wearable and flexible devices and substrates. During the semiconductor chip bonding process, the mismatch of coefficient of therm al expansion (CTE) between the substrate and the solder, and the excessive heat applied to the entire substrate and components affect the performance and reliability of the device. These problems can cause warpage and deterioration of long-term reliability of the electronic packages. In order to improve these issues, many studies on low-melting temperature solders, which is capable of performing a low-temperature process, have been actively conducted. Among the various low-melting temperature solders, such as Sn-Bi and Sn-In, Sn-58Bi solder is attracting attention as a promising low-temperature solder because of its advantages such as high yield strength, moderate mechanical property, and low cost. However, due to the high brittleness of Bi, improvement of the Sn-Bi solder is needed. In this review paper, recent research trends to improve the mechanical properties of Sn-Bi solder by adding trace elements or particles were introduced and compared.

• Archives of Plastic Surgery
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• v.35 no.1
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• pp.110-115
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• 2008

Purpose: The objective of this study is to propose an effective management of unstable zygomatic arch fracture. The reduction methods of arch fracture were relatively simple but the maintenance of reduction state is very troublesome. On this, authors introduce an effective management method of unstable zygomatic arch fracture. Methods: Authors experienced 23 cases of unstable segmental zygomatic arch fractures and used Thermo-splint in all cases. All the arch fractures were reduced through Gillies' approach under the general anesthesia. After the reduction, the most effective suspension points were marked on the covering skin of the fractured arch. A needle of heavy nonabsorbable suture material was inserted toward the marking site under the reduced zygomatic arch. And then Therm-splint was dipped in the hot water, and we got the splint pattern of patient face. Reshaped Thermo-splint was trimmed and fixated with previous suspension suture materials. More additive suspension was done if necessary. The splint was applied for in two to three weeks postoperatively. Results: In all the cases, good cosmetic and functional results were observed without severe complications. There were 4 cases of incomplete reductions but they also had no specific problems. There were no facial nerve symptom and scar(stitch mark). Postoperative slight tenderness and trismus were completely subsided after removal of the splint. Conclusion: The Thermo-splint safely protect and maintain the postoperative reduction state. The application, maintenance and removal were easy and simple. It could be reformed to any contour of face and had enough rigidity for supporting. Above all these things, effective prevention of displacement and easy manipulation were significant merit. Authors experienced good results with Thermo-splint, and would introduce it for another method of management of zygomatic arch fracture.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.3
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• pp.63-74
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• 2019

This study carried out a human risk assessment of Cu, Pb, Zn and Ni contained in soil contaminated by improperly buried heavy metal wastes in railway sites. The purpose of the human risk assessment is to derive the need for soil remediation and factors that should be considered during soil remediation. Risk assessment was performed in accordance with the Environment Ministry's Risk Assessment Guidelines. The results of the human risk assessment of contaminated heavy metal soil contaminated by improperly buried waste in the railway site were presented after the process of determining exposure concentration, calculating exposure, and determining carcinogenic hazards. The heavy metal content of soil is 621.3 Cu mg/kg, 2,824.5 Pb mg/kg, 1,559.1 Zn mg/kg and 45 Ni mg/kg, which is the exposure concentration of the target contaminant. The results of human exposure according to exposure pathways were high in the order of soil outdoor dust >soil ingestion >soil contact, and Pb >Zn >Cu >Ni were higher in order of contaminant. The carcinogenic and noncarcinogenic risks of soil contaminated with heavy metal waste were higher than the allowable carcinogenic risks (TCR> $10^{-6}$) and the risk index (Hi < 1.0) suggested by USEPA. Therefore, the site needs to be remediated.