• Journal of Korean Society of Disaster and Security
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• v.14 no.3
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• pp.51-63
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• 2021

This study is for the quality improvement of water-sealing & reinforcement grouting in tunnel of the construction of the underground transportation network underneath the city. Existing tunnel grouting process did not technically utilize P~q~t charts fully. It is due to the absence of technical methods to decide how P~q~t charts change in the presence of trouble and what the change represents in grouting. There were no standards to decide which chart pattern represents which ground characteristics, how to categorize ground types, and how to take measures according to the standards. This paper studies on the grouting type, ground characteristics, ground type categorizing method, and countermeasures for both general and algorithm-processed grouting in soil and rock layer to address the aforementioned problems. Newly improved P~q~t charts from grouting in soil was categorized into six different types. Different characteristics and categorization method was developed for each type. Countermeasures for each type of grouting process were developed so that on-site application can be readily available. Improved P~q~t charts for rock layer also have six different types of grouting. Each type was given the countermeasures for rock layer grouting process for easier applications. Therefore, it is expected to be used through out the entire process of grouting from preparation to the last report of the water-sealing & reinforcement grouting in tunnel of the construction of the underground transportation network underneath the city.

• The Journal of Korean Association of Computer Education
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• v.9 no.6
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• pp.41-51
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• 2006

Educators have recognized the usefulness of the e-BBS(electronic-Bulletin Board System) as an asynchronous communication medium for collaborative learning. However, theoretical outcomes to understand the structural analysis of thc e-BBS are not adequate enough. As a consequence, we are left with inadequate supportive tools to understand complex communication phenomena and to assist teachers to guide students to educational purposes. This can cause teachers to have a laissez-faire approach using BBS as a communication medium for education due to the lack of understanding the structural and overall situation. To address this issue, this paper presents a theoretical foundation to help understand the structure of discussion activities via the e-BBS and then presents a computational model, based on the structural analysis, for the behavioral analysis of participants. The formal representation of bi-directional discussion activities is realized by devising two graphs - the reply graph and the connection graph. Various measurements and statistics for the analysis are presented in the paper. To clarify the analysis, we classify the results produced through the analysis of discussion activities and participants' behaviors.

• Korean Journal of Environment and Ecology
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• v.25 no.3
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• pp.412-420
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• 2011

This study was conducted to quantitatively analyze the temporal change of green space network at multi-scales from 1975 to 2006 with the application of graph theory in Seoul, Korea. Remarkable change of connectivity was detected in green space networks at the scale ranging from 1,000 ~ 1,600 m during 30 years. Green spaces and their networks have been restoring after 1990 since forest areas had been fragmented in 1975. In 2006, we identified the important core habitat areas that can sustain diverse wildlife species and stepping stones composed of small patches that can link these core habitat areas. Green spaces showed high correlation with the relative importance value of green space connectivity. So, this study could graphically represent green space networks of Seoul City. Green spaces of core areas distributed at the northern and southern boundary, and those of stepping stones possessing the high value of betweenness centrality consisted at the middle, eastern and western boundary. These results indicate that green space network can be graphically and quantitatively explained by degree centrality, betweenness centrality and relative importance value of connectivity with the application of graph theory.

• Journal of the Korean Geographical Society
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• v.44 no.3
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• pp.410-427
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• 2009

This study aims to rethink the meaning of graphicacy, discuss the possible criteria to evaluate the level of graphicacy, and show how the graphicacy differs through different grades. First, it finds that as school grades advance, implicit information processing abilities, and conceptual information processing abilities were more required comparing to explicit information processing abilities, when interpreting graphic data. Secondly, the percentage of items which examinee showed a proficient level, decreased as school grades advanced. Thirdly, the graphicacy level of sixth graders was the status of being able to derive explicit information from pictorial maps and read implicit information in simple contour map or line graphs. Ninth graders were able to infer causal relationship between geographic phenomenons by utilizing graphic materials. Tenth graders could read graphic materials by utilizing simple knowledge and experience.

• Communications of Mathematical Education
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• v.23 no.3
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• pp.583-597
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• 2009

The purposes of this study are to analyze error that the students in science and engineering show in the process of thinking a extremum value. First, in view of examples of incorrect answers that appeared in a test by students in science and engineering, it has been found that the most frequent incorrect answers were due to a lack of understanding about necessary matters and concepts. In this regard, it is necessary to use various examples and pictures(graphs) to teach students in science and engineering. In addition, it has been found that it is more effective to use questions asking why it happens and why they think that way to help those having difficulties in understanding various concepts and principles.

• Journal of the Korean earth science society
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• v.30 no.7
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• pp.897-908
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• 2009

Inscriptions are integral parts of the current science textbooks, and become medium that makes sense of scientific concepts effectively. This study analyzed the inscriptions from five science textbooks at the secondary level in terms of its type, function, and structures. Analyzing types of inscriptions resulted that the ratio of frequently used photographs and illustrations were much higher than that of graphs and tables used. In case of function analysis, illustrative and complementary functions were dominant in terms of frequency and ratio, whereas explanatory, decorative and inquisitive functions were relatively rare. Inscriptions of single structure was much more than multiple structure. Multiple structure of pair and series were mainly used for representing contrast and sequence, respectively. The proportion of inscriptions in type, function and structure across the textbooks was significantly different. Based on the results, it was suggested that semiotic study about the function and the structure of inscriptions need to be carried out in earth science area to better understand the pedagogical implications of inscriptions in school science.

• Education of Primary School Mathematics
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• v.27 no.3
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• pp.227-246
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• 2024

The purposes of this study were to analyze the levels of cognitive demand and questioning types in tasks of 'Data and Chance' presented in elementary mathematics textbooks in Korea, the United States, and Australia. The levels of cognitive demand of textbook tasks were analyzed according to the knowledge and process and thinking types required in the tasks. The tasks were also analyzed for questioning types, answer types, and response types. As a result, in terms of knowledge and process and thinking types in tasks, all three countries had something in common: the percentage of tasks requiring 'representation' and process was the highest, and the percentage of tasks requiring 'basic application of skill/concept' was also the highest. From a thinking types perspective, differences were found between textbook tasks in the three countries in graph and chance learning. The results of analyzing questioning types showed that in all three textbooks, the percentage of observational reasoning questions was highest, followed by the percentage of factual questions. The proportions and characteristics of the constructing questions included in the U.S. and Australian textbooks differed from those in the Korean textbooks. Based on these results, this study presents implications for constructing elementary mathematics textbook tasks in 'Data and Chance.'

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_1
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• pp.483-491
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• 2013

By a development of car navigation systems and mobile or positioning technology, it increases interest in location based services, especially pedestrian navigation systems. Updating of digital maps is important because digital maps are mass data and required to short updating cycle. In this paper, we proposed change detection for different network data-sets based on areal feature matching. Prior to change detection, we defined type of updating between different network data-sets. Next, we transformed road lines into areal features(block) that are surrounded by them and calculated a shape similarity between blocks in different data-sets. Blocks that a shape similarity is more than 0.6 are selected candidate block pairs. Secondly, we detected changed-block pairs by bipartite graph clustering or properties of a concave polygon according to types of updating, and calculated Fr$\acute{e}$chet distance between segments within the block or forming it. At this time, road segments of KAIS map that Fr$\acute{e}$chet distance is more than 50 are extracted as updating road features. As a result of accuracy evaluation, a value of detection rate appears high at 0.965. We could thus identify that a proposed method is able to apply to change detection between different network data-sets.

• Communications of Mathematical Education
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• v.38 no.2
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• pp.263-286
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• 2024

With the introduction of AI digital textbooks, interest in the use of technology tools in mathematics education is increasing. Technology tools have the advantage of visualizing mathematical concepts and discovering mathematical principles through experimentation and inquiry. The 2015 revised mathematics curriculum in Korea already mentions the use of technology tools, and accordingly, various teaching and learning activities using technology tools are presented in mathematics textbooks. However, there is still a lack of systematic analysis on the types and utilization methods of technology tools presented in textbooks. Therefore, this study analyzed the current status of the use of technology tools presented in high school mathematics textbooks based on the 2015 revised curriculum. To this end, the types of technology tools presented in mathematics textbooks were categorized, and the utilization ratio of each category was investigated. In addition, the utilization patterns of technology tools were analyzed by subject and content area, and the utilization ratio of technology tools according to the type of teaching and learning activities was examined. The results showed that technology tools were used in various types and ratios according to the subject and content area. In particular, technology tools in the symbol-manipulation graphing software category accounted for 58% of the total usage cases, showing the highest proportion. By subject, the use of symbol-manipulation graphing software was prominent in subjects dealing with the analysis area, while the use of dynamic geometry software was relatively high in the geometry area. In terms of teaching and learning activity types, the utilization ratio of auxiliary tool type (49%) and intended inquiry induction type (37%) was high. The results of this study show that technology tools play various roles in mathematics textbooks and provide useful implications for improving mathematics teaching and learning methods using technology tools in the future. Furthermore, it can contribute to the establishment of educational policies related to AI digital textbooks and the development of teacher training programs.

• Journal of the Korean Society of Earth Science Education
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• v.10 no.1
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• pp.50-61
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• 2017

The purpose of this study is to analysis eye tracking for high school students' learning styles in the process of solving in the behavioral domains of the College Scholastic Ability Test on Earth Science I. The subjects of this study were 50 students from two classes out of 4 classes in E high school in Chungcheong province. Among them, we conducted experiments by randomly sampling 2 students of each type of learning based on the criteria that they had not encountered the problem of Earth Science I from the past two years. The findings indicate that the item correctness rate of divergers, assimilators, convergers, and accommodators were higher in the knowledge domain, application domain, knowledge-understanding domain, and understanding domain. This confirms that there is a difference among the four learning styles in the level of achievement according to the behavioral areas of the assessment questions. The latter finding was that the high eye-share of AOI 2 appeared higher than AOI 1, 3, 4 in the course of solving the problems. This is because the four types of learners pay more careful attention to the AOI 2 area, which is the cue-or-information area of problem solving, that is, the Table, Figure, and Graph area. Therefore, in order to secure the fairness and objectivity of the selection, it is necessary that an equal number of questions of each behavioral domain be selected on the Earth Science I Test of the College Scholastic Ability Test in general. Besides, it seems to be necessary that the knowledge, understanding, application, and the behavior area of the inquiry be highly correlated with the AOI 2 area in development of test questions.