• Title/Summary/Keyword: Spatial Unit of Analysis

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UAV Photogrammetry Accuracy Analysis at Marine Using Arbitrary Reference Points (임의의 기준점을 이용한 해상에서의 UAV 사진측량 정확도 분석)

  • Oh, Jae Hyun;Kim, Byung Woo;Hwang, Dae Young;Hong, Soon Heon
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.4
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    • pp.39-45
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    • 2016
  • In this study, with arbitrary reference points on the water, photogrammetry accuracy analysis was conducted using unmanned aerial vehicle(UAV). A small reservoir is a research area, and twenty buoys were used as arbitrary reference points. Errors of location coordinate were identified with control of amounts of used reference points. cases are categorized by index scores per photos. Accuracy of X is 0.141m~0.166m and accuracy of Y is 0.136m~0.241m. Considering that allowable error for the maritime boundary survey is ${\pm}2m$, it is possible to get the accuracy data available for the photogrammetry of UAV using an reference point. In addition, the coefficient of correlation between the number of reference points per unit and number of buoys used as reference point and the ratio of the reference point per square measure, and percentage of buoys used as reference point and the coefficient of x and y were performed. Each element, x, and y showed a strong correlation and the coefficient of number of buoys used as reference point was irrelevant. The results of this correlation analysis can be analyzed that the number of reference points used in each picture is greater than the actual number of reference points used in location accuracy.

An Analysis of Systems Thinking Revealed in Middle School Astronomy Classes: The Case of Science Teachers' Teaching Practices for the Unit of Stars and Universe (중학교 과학 천문 수업에서 나타나는 시스템 사고 분석: 별과 우주 단원에 대한 과학 교사의 교수 실행 사례)

  • Oh, Hyunseok;Lee, Kiyoung;Park, Young-Shin;Maeng, Seungho;Lee, Jeong-A
    • Journal of the Korean earth science society
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    • v.36 no.6
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    • pp.591-608
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    • 2015
  • The purpose of this study was to analyze system thinking revealed in science teachers' teaching practices of middle school astronomy classes. Astronomy lessons were video-taped from four eighth grade science teachers. The video recordings were all transcribed and analyzed by employing a framework for systems thinking analysis after modifying an existing frame of hierarchial structure used in relevant previous studies. In addition, four participants were interviewed in order to uncover their orientation toward teaching using video stimulated recall method. Findings are as follows: All participating teachers were not able to employ the four levels of system thinking appropriately and only utilized the low level of systems thinking. They also demonstrated teacher-centered practices for employing system thinking despite their student-centered orientation toward teaching. The main reason for these results may be that teachers focused more on spatial thinking, than on system thinking as well as the lack of teacher's knowledge about the content and formative assessment of non-earth science teachers. Implications on how to effectively employ the system thinking in astronomy class are discussed in this paper.

Major Factors Influencing Landslide Occurrence along a Forest Road Determined Using Structural Equation Model Analysis and Logistic Regression Analysis (구조방정식과 로지스틱 회귀분석을 이용한 임도비탈면 산사태의 주요 영향인자 선정)

  • Kim, Hyeong-Sin;Moon, Seong-Woo;Seo, Yong-Seok
    • The Journal of Engineering Geology
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    • v.32 no.4
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    • pp.585-596
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    • 2022
  • This study determined major factors influencing landslide occurrence along a forest road near Sangsan village, Sancheok-myeon, Chungju-si, Chungcheongbuk-do, South Korea. Within a 2 km radius of the study area, landslides occur intensively during periods of heavy rainfall (August 2020). This makes study of the area advantageous, as it allows examination of the influence of only geological and tomographic factors while excluding the effects of rainfall and vegetation. Data for 82 locations (37 experiencing landslides and 45 not) were obtained from geological surveys, laboratory tests, and geo-spatial analysis. After some data preprocessing (e.g., error filtering, minimum-maximum normalization, and multicollinearity), structural equation model (SEM) and logistic regression (LR) analyses were conducted. These showed the regolith thickness, porosity, and saturated unit weight to be the factors most influential of landslide risk in the study area. The sums of the influence magnitudes of these factors are 71% in SEM and 83% in LR.

The Structure of Interrelationship Among the Influential Factors of Migration Using Path Analysis (경로분석을 이용한 인구이동 결정요인들 간의 인과구조)

  • Lee, Hee-Yeon;Park, Jung-Ho
    • Journal of the Economic Geographical Society of Korea
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    • v.12 no.2
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    • pp.123-141
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    • 2009
  • Interregional migration is viewed as the most important component in regional population change in Korea. The purpose of this study is to analyze the structure of interrelationship among influential factors of interregional migration from the macro-viewpoint. During the period of 2000-05 the correlation between immigration and outmigration among 223 shi gun gu spatial unit was over 0.95, indicating that regions with high outmigration received high immigration. In this study the hypothesized cause-and-effect relationship among six influential factors of total migration flow was analyzed using path analysis. Based on the direct effect culturalwelfare environment has the biggest impact on immigration, while education environment and new housing environment are somewhat less and industrial-job opportunity environment the smallest impact. However based on the indirect effect, fiscal environment has the biggest impact on immigration, while industrial-job opportunity environment and infrastructure environment are somewhat less and new housing environment the smallest impact. If we consider the total effect, fiscal environment and cultural-welfare environment have the most significantly influenced on immigration. In particular, the influence of fiscal environment was remarkable in migration process through nonrecursive path and feedback loop.

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Chronological Analysis on the Accessibility Change of Outdoor Space in Apartment Complexes in Cheonan City Using Space Syntax (공간구문론을 활용한 천안시 아파트단지 외부공간의 시기별 접근성 변화 분석)

  • Lee, Ki-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.12
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    • pp.32-41
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    • 2017
  • This study examined the arrangement attribute of each component based on the relationship among the components using space syntax at the entire complex level when analyzing the outdoor space of an apartment complex in Cheonan and as a preliminary study. The accessibility change in the access space to each space and to the facilities were examined based on a resident walking in the perspective that the outdoor spaces of the apartment complex are one spatial structure connected together. The space was divided into a total of 5 periods and the access space to the facilities and spaces located in outdoor space of the apartment complex were established as the unit space. In this study, a total of 6 analysis items were established: main complex access space, main building access space, shopping mall within complex, control office/center for senior citizens, children's playground, and resident sports facilities. In the analysis, the following conclusion was obtained. First, the accessibility to the main complex access space was high over almost all periods and the main building access space generally showed low accessibility. Second, the shopping mall showed a tendency that the closer the period, the more the accessibility is increased. Third, the control office/center for senior citizens, which can be considered as a common resident space and the children's playground out of the resident sports facilities, showed an exceptional tendency, the integration order was constantly high without a large change by the period and the control office/center for senior citizens showed the tendency for a high integration order, indicating that it is planned mainly in a location with good accessibility.

Analysis of activities task using multiple intelligence in middle school 「Technology·Home Economics」 textbooks - Focusing on the 'Dietary Life' unit according to the curriculum of the 2015 revised Practical Arts(Technology·Home Economics) curriculum - (중학교 기술·가정 교과서 다중지능 활용 활동과제 분석 - 2015 개정 실과(기술·가정) 교육과정에 따른 '식생활' 단원을 중심으로 -)

  • Choi, Seong-Youn;Lee, Young-Sun;Choi, Ye-Ji;Joo, Hyun-Jung;Kim, Seung-Hee;Park, Mi-Jeong
    • Journal of Korean Home Economics Education Association
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    • v.30 no.3
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    • pp.19-42
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    • 2018
  • The purpose of this study is to analyze the tasks of 'dietary life' in the textbook developed according to the 2015 revised middle school 「Technology·Home economics」 education curriculum based on the multiple intelligence teaching and learning methods. To accomplish this purpose, 12 textbooks of middle school 「Technology·Home economics」 textbooks were titled "Nutrition and Dietary Behavior of Adolescents", "Planning and Choosing Meals", "Choosing Foods and Safe Cooking" except the questions, the tasks that the students can perform are analyzed based on the teaching and learning methods using multiple intelligences. Analysis methods were analyzed by using contents analysis method, focusing on learning activities, and sub-questions of activities were all included in each activity, and the process of preparing activities on a continuous line was grouped into one. Three people analyzed the activities and proceeded to revise and supplement the analysis standard through consultation. The other three researchers confirmed it. As a result of analyzing 12 kinds of textbooks, the number of activity tasks was 25~74 for each kind of textbooks, and the total number of activities was 527. According to the ratio of multiple intelligences, 35% of the tasks were using logical-mathematical intelligence, and 26.8% of linguistic intelligence, 23% of intrapersonal intelligence, 7.2% of interpersonal intelligence, 3.8% of spatial intelligence, bodily-kinesthetic(2.7%) and musical intelligence(1.5%). On the other hand, it was analyzed that there is no activity task using naturalist intelligence. Except to the naturalist intelligence, general intelligence was utilized. This indicates that the home economics curriculum is a convergence of the home economics curriculum in that it is a reorganization by extracting the contents and methods of other curriculum related to dietary life, is interpreted. This study is expected to provide a framework for various teaching and learning methods to activate students' participation classes and to provide an alternative to realize convergence education in home economics curriculum.

Prediction Study on Major Movement Paths of Otters in the Ansim-wetland Using EN-Simulator (EN-Simulator를 활용한 안심습지 일원 수달의 주요 이동경로 예측 연구)

  • Shin, Gee-Hoon;Seo, Bo-Yong;Rho, Paikho;Kim, Ji-Young;Han, Sung-Yong
    • Journal of Environmental Impact Assessment
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    • v.30 no.1
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    • pp.13-23
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    • 2021
  • In this study, we performed a Random Walker analysis to predict the Major Movement Paths of otters. The scope of the research was a simulation analysis with a radius of 7.5 km set as the final range centered on the Ansim-wetland in Daegu City, and a field survey was used to verify the model. The number of virtual otters was set to 1,000, the number of moving steps was set to 1,000 steps per grid, and simulations were performed on a total of 841 grids. As a result of the analysis, an average of 147.6 objects arrived at the boundary point under the condition of an interval of 50 m. As a result of the simulation verification, 8 points (13.1%) were found in the area where the movement probability was very high, and 9 points (14.8%) were found in the area where the movement probability was high. On the other hand, in areas with low movement paths probabilities, there were 8 points (13.1%) in low areas and 4 points (6.6%) in very low areas. Simulation verification results In areas with high otter values, the actual otter format probability was particularly high. In addition, as a result of investigating the correlation with the otter appearance point according to the unit area of the evaluation star of the movement probability, it seems that 6.8 traces were found per unit area in the area where the movement probability is the highest. In areas where the probability of movement is low, analysis was performed at 0.1 points. On the side where otters use the major movement paths of the river area, the normal level was exceeded, and as a result, in the area, 23 (63.9%), many form traces were found, along the major movement paths of the simulation. It turned out that the actual otter inhabits. The EN-Simulator analysis can predict how spatial properties affect the likelihood of major movement paths selection, and the analytical values are used to utilize additional habitats within the major movement paths. It is judged that it can be used as basic data such as to grasp the danger area of road kill in advance and prevent it.

Estimation of Flows and Pollutant Loads from GIS Analysis using Cell-based Geospatial and Georgraphic Information Data (격자기반의 지형 및 지리정보자료와 GIS분석기법을 이용한 유역의 유출량 및 오염부하량 추정)

  • Cho, Jae-Myoung;Lee, Mi-Ran;Yun, Hong-Sik
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.4
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    • pp.381-392
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    • 2011
  • Pollutant loads calculated with unit factor method can not identity seasonal variations of pollutant inputs. Estimation of pollutant loads considering rainfall runoff can overcome these limits. SCS curve number method was applied to estimate runoff of each event of Koeup watershed of Koheung estuary lake. SCS curve numbers were calculated based upon land use, soil types of the catchment using GIS. Point and nonpoint source pollutant loads were summed up for total loads estimation. Those from nonpoint source were estimated by multiplying the calculated runoff and expected mean concentrations (EMC) presented by the Minister of Environment of Korea. DEM can present three dimensional views of a terrain, identity stream networks and flow accumulation. Furthermore, it can examine accumulated pollutant loads of specific point of a catchment. Therefore, cell based pollutant load estimation was attempted using DEM. ArcView was utilized to collect, store and manipulate spatial and attribute data of pollutant sources and features of the catchment. Cell-based DEM which was established by the GRID module of ARC/INFO was employed to estimate flows and pollutant loads.

Fire District Adjustment for Improving Fire Service Vulnerable Areas in Jinju (진주시 소방서비스 취약지역 개선을 위한 소방권역 조정)

  • Yoo, Hwan Hee;Koo, Seul
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.1
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    • pp.19-26
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    • 2013
  • This study analyzed the vulnerable areas to the fire service in regard to 119 safety centers, currently established in Jinju city. In this study, the district of fire was examined through the analysis of the OD cost matrix to find the transference or increase methods of the existing centers for improving the fire services. The study results demonstrate that the numbers of 119 safety centers were lacking in comparison with the areas of the administrative district in Jinju. In particular, relocation and the transference or increase of centers were required for the Cheonjeon 119 safety centers, which is the creation area of the National Industrial Complex among five 119 safety centers located in Jinju, and the fire service jurisdiction of Munsan 119 safety centers (including Banseong 119 regional unit), which is the location of a big fire risk due to the increase of population according to the development of the new town. In addition, the OD cost matrix analysis in this study reveals the fact that the time of fire service in the Jeonchon Industrial Complex, which is the significantly vulnerable area, will be reduced from 8 minutes to 3.3 minutes if the current Cheonjeon 119 safety center is moved to Gaho-dong. It indicates that the increase of safety centers in Geumsan-myeon areas, where the population has increased rapidly in recent days due to the development of the new town, is keenly needed.

Present-Day Climate of the Korean Peninsula Centered Northern East Asia Based on CMIP5 Historical Scenario Using Fine-Resolution WRF (CMIP5 Historical 시나리오에 근거한 WRF를 이용한 한반도 중심의 동북아시아 상세기후)

  • Ahn, Joong-Bae;Hong, Ja-Young;Seo, Myung-Suk
    • Atmosphere
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    • v.23 no.4
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    • pp.527-538
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    • 2013
  • In this study, climate over Korea based on the Historical scenario induced by HadGEM2-AO is simulated by WRF. For this purpose, a system that can be used be for numerical integration over the Far East Asian area of the center of the Korean Peninsula with 12.5 km-horizontal resolution was set-up at "Haebit", the early portion of KMA Supercomputer Unit-3. Using the system, the downscaling experiments were conducted for the period 1979-2010. The simulated results of HadGEM2-AO and WRF are presented in terms of 2 m-temperature and precipitation during boreal summer and winter of Historical for the period 1981~2005, compared with observation. As for the mean 2 m-temperature, the general patterns of HadGEM2-AO and WRF are similar with observation although WRF showed lower values than observation due to the systematic bias. WRF reproduced a feature of the terrain-following characteristics reasonably well owing to the increased horizontal resolution. Both of the models simulated the observed precipitation pattern for DJF than JJA reasonably, while the rainfall over the Korean Peninsula in JJA is less than observation. HadGEM2-AO in DJF 2 m-temperature and JJA precipitation has warm and dry biases over the Korean Peninsula, respectively. WRF showed cold bias over JJA 2 m-temperature and wet bias over DJF precipitation. The larger bias in WRF was attributed to the addition of HadGEM2-AO's bias to WRF's systematic bias. Spatial correlation analysis revealed that HadGEM2-AO and WRF had above 0.8 correlation coefficients except for JJA precipitation. In the EOF analysis, both models results explained basically same phase changes and variation as observation. Despite the difference in mean and bias fields for both models, the variabilities of the two models were almost similar with observation in many respects, implying that the downscaled results can be effectively used for the study of regional climate around the Korean Peninsula.