• Journal of Korean Society on Water Environment
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• v.27 no.4
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• pp.499-508
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• 2011

We analyzed the variations of water quality with flow regime alterations to determine the characteristics of the stream where the stream management is considerably difficult due to the high variability of the flow rates. In this study, both flow rates and water qualities were monitored at the tributaries, 34 in count, of both Geum River and Sabgyo Lake Basins. The variation of water qualities were divided into 2 types, based on their stream flow rates, known as Type I and Type II. If the water quality of a stream increases during low flow rate periods compared with high flow rate periods, it is classified as Type I; if the water quality of the stream increases during high flow rate periods compared with low flow rate periods, it falls under Type II. The analysis for the variations of water qualities, of all 43 basins, resulted to 24 basins under Type I and Nineteen 19 basins under Type II. The variations of water qualities were analyzed first by using Regression Analysis followed by Statistical Analysis. The average slope of the variations of water qualities and the slope of the standard deviations were 0.00135 and 0.00477, respectively. The Probability Distributions of both Type I and Type II basins were 61.1% and 38.9%, respectively. The basin having a probability distribution of 61.1% and is also known as Type I, increases during periods of low flow rates, due to the presence of point sources. Therefore, the basin should be enforced with stream management. Before the stream management can be implemented in all streams falling under Type II, the sources of contaminants should first be estimated. These contaminants can be classified into two parts, the first is Point source pollution and the second is Non-point source pollution, where the Non-Point source pollution can be sub-divided into two types, with storm runoff and without storm runoff.

• Journal of People, Plants, and Environment
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• v.22 no.6
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• pp.551-561
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• 2019

This study was conducted to find out differences in the removal efficiency of particulate matter (PM) depending on the type of plants and the morphological characteristics of leaves. A total of 12 plants were used, with three plants selected for each type of leaves (big leaf, small leaf, compound leaf, needle leaf). We measured the removed amount of PM10 and PM2.5, the structure of the abaxial leaf surface, and the weight of the wax layer of each plant. Plants with the high removal efficiency of PM included Pachira aquatica Aubl., Ardisia crenata, and Dieffenbachia 'Marianne', and plants with the low removal efficiency included Nandina domestica Thunb, Schefflera arboricola, and Quercus dentata. The abaxial leaf surface having a high removal efficiency of PM had many large wrinkles, and the abaxial leaf surface having a medium removal efficiency was flat and smooth. On the other hand, there were many fine hairs on the abaxial leaf surface with a low removal efficiency. According to the plant leaf type, the PM10 removal efficiency of plants with needle leaves was about three times higher than that of other plants. In particular, the wax layer of conifers weighed 6-24 times higher than those of other plants. The stomata of conifers were evenly distributed on the adaxial and abaxial leaf surfaces; however, the stomata of Sciadopitys verticillata appeared in the form of papillae unlike general stomata. Therefore, the removal efficiency of PM varied depending on the macro-, and micro-morphological characteristics of plant leaves such as the structure of the abaxial leaf surface, and the weight of the wax layer. Based on this research, selecting plants that are effective in reducing PM in consideration of the plant type and leaf characteristics will improve indoor air quality and decrease exposure of PM to human body.

• Journal of Science Education
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• v.40 no.3
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• pp.254-266
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• 2016

In this study, MBL experiments in the Korean secondary science textbooks and chemistry textbooks under the 2007 and the 2009 curriculum revision were analyzed in terms of curriculum revision era, grade, context of experiment in the textbook, field of science, topic, sensor, and publisher. As a result, 25 MBL experiments were found in the science textbooks under the 2007 revision, and 29 experiments under the 2009 revision (19 for middle school textbook and 10 for high school textbook). MBL experiments in middle school textbooks were not increased after curriculum revision while those in high school textbooks appeared for the first time. Most of them were in the textbooks for grade 7 and presented as an essential experiment rather than optional one. Motion sensor and temperature sensor were used most frequently, and oxygen sensor and carbon dioxide sensor were followed. In aspect of publishers, a frequency of MBL experiment was decreased in most textbook and some publishers didn't include MBL experiment at all. Based on these results, educational implications were discussed.

• Korean Journal of Remote Sensing
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• v.29 no.1
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• pp.151-160
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• 2013

Recently, although many efforts have been made to estimate insolation over Korean Peninsula based on satellite imagery, most of them have utilized overseas satellite imagery. This paper aims to estimate insolation over the Korean Peninsula based on the Korean stationary orbit satellite imagery. It utilizes level 1 data and level 2 cloud image of COMS MI, the first meteorological satellite of Korea, and OMI image of NASA as input data. And Kawamura physical model which has been known to be suitable for East Asian area is applied. Daily global horizontal insolation was estimated by using satellite images of every fifteen minutes for the period from May 2011 to April 2012, and the estimates were compared to the ground based measurements. The estimated and observed daily insolations are highly correlated as the $R^2$ value is 0.86. The error rates of monthly average insolation was under ${\pm}15%$ in most stations, and the annual average error rate of horizontal global insolation ranged from -5% to 5% except for Seoul. The experimental results show that the COMS MI based approach has good potential for estimating insolation over the Korean Peninsula.

• Journal of the Korean association of regional geographers
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• v.16 no.5
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• pp.474-496
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• 2010

In this article I try to investigate fifteen place names presented in the area of Baekdu mountain and Duman river of "Daedongnyeojido". The aims of the investigation are to clear Jeongho Kim's understanding on the national boundary implicated in the map, to search the etymology of the place names, and to analyze the place names miswritten. Through the investigation it will be suggested that the map presents the idea of 'Tomun river = Duman river = Bungye river', and recognizes 'Abrok river-Jeonggyebi-Duman river' as the landmarks of the boundary between Joseon(Korea) and Qing(China). Through the etymological analysis of the place names it will be suggested that some place names(Bundonggang, Geongatoi, Sihuasan, Geolodong and Daedong) originated from Nuzhen(Manchurian), the other place names(Gulsan and Guambong) originated from Korean. The location of the place names will be suggested also.

• The KIPS Transactions:PartC
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• v.12C no.4 s.100
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• pp.597-602
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• 2005

In this study, file size for measurement and the service system's billing data were submitted to a comparative analysis by performing a verification test on the billing system of three major mobile communication services providers, based on the wireless Internet service packet. As shown in the result of the verification test, there were some differences in the billing data due to transmission overhead, according to the network quality that is affected by the wireless environment of mobile operators. Consequently, the packet analysis system was proposed as a means of applying consistent packet billing to all service providers being compared. If the packet analysis system is added to supplement the current billing system various user requirements can be met. Billing by Packet among mobile operators and differentiated billing based on the content value are available, since the packet data can be extracted through protocol analysis by service, and it can be classified by content tape through traffic data analysis. Furthermore, customer's needs can be satisfied who request more information on the detailed usage, and more flexible and diverse billing policies can be supported like application of charging conditions to the non-charging packet handling. All these services are expected to contribute to the popularization of the wireless Internet service, since user complaints about the service charge could be reduced.

• Korean Journal of Cognitive Science
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• v.24 no.1
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• pp.49-69
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• 2013

While we interact with other people or objects, the brain continuously updates our own body schema to recognize the agent of observed actions. The Extrastriate Body Area (EBA) provides an initial interface for the sense of agency by integrating visual inputs of body parts with internal signals related to self-generated body movements. Less is known, however, about how the functional use of tools contributes to such processes. Here, we investigated whether tool-specific affordance would differentially affect the neural responses in the EBA depending on the agency of imaginary actions. In each trial we presented a picture of an object in a rectangular frame. Objects were either the tools typically brought towards the body (body tools; e.g., telescope, earphones) or away from the body (world tools; e.g., pen, dice; Rueschemeyer, Pfeiffer, & Bekkering, 2010). Depending on the color of the frame, participants imagined either themselves or the other person using the tool (self vs. other conditions). These four types of trials were randomly intermixed with blank trials. As results, independently localized right EBA regions of interest showed greater activation when participants imagined themselves using body tools than using world tools whereas no such differential activations were found when they imagined the other person using the tools. The postscan test revealed no significant difference in vividness of imagery between the self and other conditions. Our results suggest that the EBA incorporates functional affordance of tools into the body schema in order to enhance the sense of agency and to guide our own actions.

• Journal of the Korean Chemical Society
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• v.62 no.1
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• pp.43-51
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• 2018

In this study, visually impaired secondary students' conception of "changes of state of water" was explored. Science inquiry activity for students with visual impairments was implemented to 16 middle school students and 15 high school students from school for the blind. 14 of them were totally blind, 13 had low vision and the others were not identified. Inquiry activities were conducted by communicating with the researcher while students were individually exploring the molecular models of water and ice developed for the study. After the exploration, students were asked to explain the concept of changes of state of water with the model they explored. Opinion on the need and the usability of this kind of tactile model was also asked to them. All conversations were recorded, transcribed, and analyzed. As a result, students with visual impairments answered exactly about the materials used for the model and their numbers. However, they didn't know what the model stood for. They had experiences of learning molecule of water and changes of state of water, but it was a phenomenon and superficial understanding. Students got to understand the molecular structures of water and ice, and had a positive perception on the need and the usability of the model. Based on these results, educational implications were discussed.

• Journal of The Korean Association For Science Education
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• v.38 no.1
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• pp.87-96
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• 2018

In this study, the trend of research and practice of science education for students with special educational needs was discussed in consideration of the aim of science education. Since the 1980s 'science for all' has been suggested as an important goal of science education and it has been pursued in the National Curriculum of Korea with differentiated teaching and learning approach. The meaning of 'science for all' should be expanded to science education for all students including minorities. However, comparing to 'normal' students, there have been relatively little researches and practices for those who need special educational supports as to meet their special talents or as to meet their special mental or physical challenges. Especially, the efforts for handicapped students or students with special educational needs (SEN) have been deficient in comparison to that of talented or gifted students. In this study the authors introduced the history and procedures of a 'Science Fair of Hope' with SEN students as an example of practice of science education for all, and then described the change among pre-service science teachers' attitudes towards disability and inclusive education, so as to discuss the practice and significance of science education for all students including SEN students.

• Journal of The Korean Association For Science Education
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• v.35 no.4
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• pp.609-618
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• 2015

The purpose of this study is to investigate the perspectives of science educators on the learning situations of visually impaired students through scientific inquiry in a darkroom. Twenty-four science educators who came to the annual conference of the Korean Association for Science Education volunteered to participate in 'the scientific inquiry in the darkroom' activities. They were encouraged to touch models of 'the molecular structure of ice' and 'the structure of eyes' and to discuss with participants during the activities. Surveys were done before and after darkroom activities, and the discussions during and after the activities were recorded and analyzed. As a result, participants recognized that science education for visually impaired students is both very feasible and necessary. Also, some of them, who have had an experience of teaching blind students and thought that they fully understood the learning situation of the visually impaired, were especially surprised by the fact that they did not actually understand how it was like to be a visually impaired and responded that they were able to more deeply comprehend the learning situation of visually impaired students through these activities. Through this experience, participants also became resolute to try more deeply to understand not only the visually impaired students, but also sighted students with learning disabilities. Based on these results, educational implications of scientific inquiry in the darkroom were discussed.