• Korean Journal of Remote Sensing
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• v.36 no.3
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• pp.461-474
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• 2020

Korea launched Geostationary Environmental Monitoring Satellite (GEMS), a UV/visible spectrometer that measure pollution gases on 18 February 2020. Because satellite retrieval is an ill-posed inverse solving process, the validation with ground-based measurements or other satellite measurements is essential to obtain reliable products. For this purpose, satellite-based OMI and OMPS total column ozone (TCO), and ground-based Pandora TCO in Busan and Seoul were selected for future GEMS validation. First of all, the goal of this study is to validate the ground ozone data using characteristics that satellite data provide coherent ozone measurements on a global basis, although satellite data have a larger error than the ground-based measurements. In the cross validation between Pandora and OMI TCO, we have found abnormal deviation in ozone time series from Pandora #29 observed in Seoul. This shows that it is possible to perform inverse validation of ground data using satellite data. Then OMPS TCO was compared with verified Pandora TCO. Both data shows a correlation coefficient of 0.97, an RMSE of less than 2 DU and the OMPS-Pandora relative mean difference of >4%. The result also shows the OMPS-Pandora relative mean difference with SZA, TCO, cross-track position and season have insignificant dependence on those variables.In addition, we showed that appropriate thresholds depending on the spatial resolution of each satellite sensor are required to eliminate the impact of the cloud on Pandora TCO.

• Science of Emotion and Sensibility
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• v.12 no.4
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• pp.489-500
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• 2009

This research takes a user-centered approach to define relevance, the core concept in information retrieval. The literature on relevance has identified numerous factors affecting such a judgment. We examined the model of user relevance judgment that describes the relationship between user relevance criteria and different types of relevance with information search task. We consider 7 criteria of user relevance-topicality, novelty, reliability, understandability, specificity, richness, and interest-and 3 type of user relevance-cognitive relevance, situational relevance, and affective relevance. Data were collected from a semi-controlled survey and analyzed by a structural equation modeling. As a result, topicality and reliability were found to be the essential relevance criteria in all information retrieval tasks. In the fact search task, topicality, reliability, novelty, richness, and interest were found to be significant. In the problem solving search task, topicality, reliability, understandability, and specificity were found to be significant. In the decision making search task, topicality, reliability, novelty, understandability, richness, specificity, and interest were found to be significant. In addition, the relationships between types of user relevance were determined. This research made theoretical and practical contributions to the field of information retrieval by identifying a definite model of user relevance judgment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.122-126
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• 2017

The aim of this study was to develop a device for solving the heating problem of living space using heated air, utilizing a simple air heater type collector for solar energy. At the present time, this study assessed the possibility of a development system through theoretical calculations for the amount of available energy according to the size change of the air-heated solar energy collector. To produce and supply hot water using the heat energy of the sun, hot water at $100^{\circ}C$ or less was produced using a flat or vacuum tube type collector. The purpose of this study was to research the air heating type solar collector that utilizes heating energy with heating air above $75^{\circ}C$, by designing and manufacturing an air piping type solar collector that is a simpler type than a conventional solar collector system. The analysis results were obtained for the generated air temperature ($^{\circ}C$) and the production of air (kg/h) to determine the performance of air heating by an air-heated solar collector according to the heat transfer characteristics in the collector of the model when a specified amount of heat flux was dropped into a solar collector of a certain size using PHOENICS, which is a heat flow analysis program applying the Finite Volume Method. From the analysis result, the temperature of the air obtained was approximately $40.5^{\circ}C$, which could be heated using an air heating tube with an inner diameter of 0.1m made of aluminum in a collector with a size of $1.2m{\times}1.1m{\times}0.19m$. The production of air was approximately 161 m3/h. This device can be applied to maintain a suitable environment for human activity using the heat energy of the sun.

• The Journal of Industrial Distribution & Business
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• v.9 no.8
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• pp.51-60
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• 2018

Purpose - Civil affairs are increasing in various forms, but civil servants who are able to handle them want to reduce the complaints and provide keywords that will help in the future due to their lack of time. While various ideas are presented and implemented as policies in solving civil affairs, there are many cases that are not policies that people can sympathize with. Therefore, it is necessary to analyze the complaints accurately and to present correct solutions to the analyzed civil complaint data. Research design, data, and methodology - We analyzed the complaints data for the last three years and found out how to solve the problems of Yongin City and alleviate the burdens of civil servants. To do this, the Hadoop platform and Design Thinking process were reviewed, and proposed a new process to fuse it. The big data analysis stage focuses on civil complaints - Civil data extraction - Civil data analysis - Categorization of the year by keywords analyzing them and the needs of citizens were identified. In the forecast analysis for deriving insights, - The case of innovation case study - Idea derivation - Idea evaluation - Prototyping - Case analysis stage used. Results - Through this, a creative idea of providing free transportation cards to solve the major issues of construction, apartment, installation, and vehicle problems was discovered. There is a specific problem of how to provide these services to certain areas, but there is a pressing need for a policy that can contribute as much as it can to the citizens who are suffering from various problems at this moment. Conclusions - In the past, there were many cases in which free traffic cards were issued mainly to the elderly or disabled. In other countries, foreign residents of other area visit the areas for accommodation, and may give out free transportation cards as well. In this case, the local government will be able to set up a framework to present with a win-win scenario in various ways. It is necessary to reorganize the process in future studies so that the actual solution will be adopted, reduce civil complaints, help establish policies in the future, and be applied in other cities as well.

• Journal of the Korean Society for Library and Information Science
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• v.48 no.4
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• pp.267-295
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• 2014

The purpose of this study is to analyze empirically relationships between learners' psychological factors, knowledge sourcing behavior and knowledge utilization outcomes and to analyze the mediation effect of social learning and relationships among learners. Another purpose is to understand learners' attitude on social learning and knowledge sourcing behavior. The main results of this study are as follows: First, regression results on relationships among learners' psychological factors, knowledge sourcing behavior, knowledge utilization outcomes show that learners' self-efficacy has a positive effect on social learning activity participation, and goal orientation has a positive influence on group knowledge sourcing and social learning activity participation. Users' experiences of social media has a positive effect on group knowledge sourcing, social learning activity participation and social learning interaction. From a knowledge utilization perspective, published knowledge sourcing positively affects knowledge reuse, knowledge application and knowledge innovation. Dyadic knowledge sourcing has positive influence on knowledge reuse. Group knowledge sourcing affects positively knowledge application and knowledge innovation. Second, social learning activity participation factor has full mediation effect on relationship between learners' goal orientation and group knowledge sourcing, and the relationship between users' experiences of social media and group knowledge sourcing. A relationship among members factor has full mediation effect on the relationship between published knowledge sourcing and knowledge reuse, and relationship between published knowledge sourcing and knowledge innovation. Third, the results of in-depth interview show that learners trust and easily collect knowledge from social network services in general. Also, they get a variety of idea for solving information problem from interaction among members in social learning community.

• Journal of Educational Research in Mathematics
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• v.24 no.2
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• pp.181-204
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• 2014

This research aims to have some implications for revision of curriculum and textbooks by analysing connections between the 2009 revised national curriculum and its textbooks in elementary school mathematics. The results of analyses for 3~4 grades can be summarized in four aspects: Firstly, we noticed that the reconstructed achievement criteria were reflected properly in the textbooks except for use of calculators in 'Numbers and Operations'. Secondly, the analysis of connections between unit objectives of textbooks and the reconstructed achievement criteria suggests that 10 units must receive attention. Especially, the range of decimal numbers for adding and subtracting needs to be corrected. Thirdly, mathematical terms and symbols excluding 'unit fraction' were found in the textbooks. Finally, mathematical processes were also fully reflected in the textbooks. However 'simplifying' as a strategy for problem solving was only missing. This result shows good or poor connections between the curriculum and its textbooks, therefore it is expected to be used effectively to revise the national curriculum for mathematics and its textbooks.

• Journal of Science Education
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• v.37 no.2
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• pp.374-388
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• 2013

The purpose of this study was to investigate pre-service physics teachers' perceptions on the physics education major curriculum. We surveyed 15 junior, and 13 senior college students of physics education major in an university in southern part of Korea. Among them, 24 participants(86 %) took the physics 1 course in high school and 22 participants(79 %) chose the physics 1 in their Korea Scholastic Aptitude Test. The responses showed that the most necessary part in pre-service students' learning was the understanding of high school level physics(36 %), and the understanding of introductory level physics(29 %). In the wish list of courses to be open, high school level physics course was ranked first among seven options by 61 % of respondents. Also, there was some concurrence among respondents in opinion of the necessity for understanding introductory physics. Students felt difficulties in understanding it especially owing to the lack of problem solving skill and comprehension. They added that the sufficient explanation of core concepts should be the first action in the innovative plan. Most participants of pre-service physics teachers hoped to have the revised major curriculum which could help their understanding of high school level or introductory level of physics. However, there was a gap of opinions between the group of students with completion of the high school physics 1 & 2 course and those with non-completion of them. The approach of changing major curriculum with consideration of learners' needs was recommended because the number of students with completion of the high school physics course would probably be decreasing rapidly under these circumstances such as the application of new national curriculum, the reduction of the number of the elective courses in Korea Scholastic Aptitude Test and so on.

• Journal of The Korean Association For Science Education
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• v.33 no.7
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• pp.1418-1430
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• 2013

In this study, we investigated the writing process components and the writing strategies that appeared in the process of argumentative writing through students' think-alouds and semi-structured interviews. The subjects were 18 eighth graders. During argumentative writing, students were asked to decide whether they agreed with the given argument or not on the basis of information provided in the writing task. We categorized the writing process components and the writing strategies by analyzing the protocols of students' think-alouds and interviews, and evaluated the level of their written compositions. The analyses of the results indicated that the writing process components of argumentative writing showed different characteristics from those of problem solving writing in several components such as setting goals, organizing an outline, and evaluating content. In addition, the writing process component 'coordinating information' was newly discovered in argumentative writing. The writing strategies were categorized into four groups by the types of decision making (reflective/intuitive) and the existence of outline organization: Reflective decision making and outline organization, reflective decision making and no outline organization, intuitive decision making and outline organization, and intuitive decision making and no outline organization. Students with the reflective decision making and outline organization strategy were found to get the highest scores in written composition in terms of the relationship between the argument and its grounds, the rebuttal of the opposing argument, and the structure of the writing. Educational implications are discussed.

• Fire Science and Engineering
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• v.25 no.6
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• pp.136-145
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• 2011

One of a large proportion among the causes of fire is electrical factors, and of fire by electric factors, the accident which accounted for over certain percentage is electric leakage and ground fault. In order to reduce the electric leakage and ground fault, the technical guidelines on the protection of ground fault in the low-voltage electrical line (KECG 1091-2011) was amended for reflecting recent international standard, IEC 60364-4-41, and new conservation methods, which improved the reliability by recovering the facility's all-time use operation and breakdown defect, was on the rise. Accordingly, in this paper, after grasping the fire's status for last 10 years and analyzing the risk of electrical fires, and as a way to improve the electric leakage and ground fault accident which accounted for more than certain percentage, the revision of KECG 1091-2011 will be reviewed. And then, after applying to the preventive conservation methods in order to enhance the protection reliability of electric leakage and ground fault detection, the problems at issue routine inspection scheme and durable years scheme in time-scheduled conservation method are listed, along with suggestion of the problem-solving scheme, and the leakage current integrated monitoring systems and digital electric leakage devices by status monitor conservation method will be proposed.

• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.649-656
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• 2015

The objective of this study was to analyze the optimal thinning regimes for timber or carbon managements in Cryptomeria japonica stands of Hannam Experimental Forest, Korea Forest Research Institute. In solving the problem, PATH algorithm, developed by Paderes and Brodie, was used as the decision-making tool and the individual-tree/distance-free stand growth simulator for the species, developed by Kwon et al., was used to predict the stand growth associated with density control by thinning regimes and mortality. The results of this study indicate that the timber management for maximum net present value (NPV) needs less number of but higher intensity thinnings than the carbon management for maximum carbon absorption does. In case of carbon management, the amount of carbon absorption is bigger than that of timber management by about 6% but NPV is reduced by about 3.2%. On the other hand, intensive forest managements with thinning regimes promotes net income and carbon absorption by about 60% compared with those of the do-nothing option.