• Title/Summary/Keyword: Temporal Difference

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Influences on Time and Spatial Characteristics of Soccer Pass Success Rate: A Case Study of the 2018 World Cup in Russia (시간과 공간적 특성에 따른 축구 패스 성공률 분석: 2018 러시아 월드컵 대회 자료를 중심으로)

  • Lee, Seung-Hun;Kim, Young-Hoon
    • Journal of Digital Convergence
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    • v.19 no.1
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    • pp.475-483
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    • 2021
  • The purpose of this study is to identify the temporal and spatial characteristics of pass accuracy by utilizing the second processing data and official records collected from the 2018 FIFA World Cup Russia video data. For a total of 128 games, the success rate of passes based on the results of the game, passing time, and passing position was two-way ANOVA with repeated measure. The results showed no difference between winning and losing groups, and no interaction effects were found for passing time and location. The difference in passing time was high in the first half, with the highest success rate in the middle of the first half (79.2%) and the middle of the second half (77.9%) in the 15~30 minutes and the 60~75 minutes. Pass success rates were in the order of defense-midfield area (83.9%), midfield-attack area (81.7%), defense area (70.6%) and attack area (61.1%). In conclusion, there was no difference in the passing success rate of the winning and losing teams depending on the characteristics of the relative competitive strength of the World Cup games, and it is believed that follow-up research is needed to analyze the game contents rather than the factors of the winning and losing in the future.

Spatial Composition Affecting Bird Collision in Suwon-city, South Korea (수원시의 조류 충돌에 영향을 미치는 공간 구성)

  • Kim, Suryeon;Choi, Jaeyeon;Seo, Jayoo;Kim, Sukyoung;Baek, Jiwon;Song, Wonkyong;Park, Chan
    • Journal of Environmental Impact Assessment
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    • v.31 no.4
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    • pp.241-249
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    • 2022
  • Humans and wild birds coexist in cities, where habitat fragmentation due to urbanization threatens the habitat and movement of birds. In this study, in order to identify landscape features associated with wild bird collide, we characterized landscape composition within a 500 m radius and points of wild bird carcasses in Suwon-city, South Korea. Dead birds were identified as having a Normalized Difference Vegetation Index (NDVI) of 0.3, Normalized Difference Built-up Index (NDBI) of -0.05, and Normalized Difference Water Index (NDWI) of -0.16 at the points of collide. And there were NDVI of 0.34, NDBI of -0.01, NDWI of -0.18, building height of 13.8 m, and soundproof wall length of 227.3 m within a radius of 500 m. Land cover type was dominated by grassland, used area, and bare land. In particular, the edges of urbanized areas, where apartments bordered forests, reservoirs, and golf courses, were identified as high-risk spaces. In order to minimize bird mortality risk in urban environments, the impact of changes to a vertical landscape should be reviewed from an environmental impact assessment approach. In addition, a preventive management plan that considers the temporal and spatial features that wild animals can safely avoid and adapt to in urbanized spaces should be prepared.

A Theoretical Study on the Landscape Development by Different Erosion Resistance Using a 2d Numerical Landscape Evolution Model (침식저항도 차이에 따른 지형발달 및 지형인자에 대한 연구 - 2차원 수치지형발달모형을 이용하여 -)

  • Kim, Dong-Eun
    • Economic and Environmental Geology
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    • v.55 no.5
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    • pp.541-550
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    • 2022
  • A pre-existing landform is created by weathering and erosion along the bedrock fault and the weak zone. A neotectonic landform is formed by neotectonic movements such as earthquakes, volcanoes, and Quaternary faults. It is difficult to clearly distinguish the landform in the actual field because the influence of the tectonic activity in the Korean Peninsula is relatively small, and the magnitude of surface processes (e.g., erosion and weathering) is intense. Thus, to better understand the impact of tectonic activity and distinguish between pre-existing landforms and neotectonic landforms, it is necessary to understand the development process of pre-existing landforms depending on the bedrock characteristics. This study used a two-dimensional numerical landscape evolution model (LEM) to study the spatio-temporal development of landscape according to the different erodibility under the same factors of climate and the uplift rate. We used hill-slope indices (i.e., relief, mean elevation, and slope) and channels (i.e., longitudinal profile, normalized channel steepness index, and stream order) to distinguish the difference according to different bedrocks. As a result of the analysis, the terrain with high erosion potential shows low mean elevation, gentle slope, low stream order, and channel steepness index. However, the value of the landscape with low erosion potential differs from that with high erodibility. In addition, a knickpoint came out at the boundary of the bedrock. When researching the actual topography, the location around the border of difference in bedrock has only been considered a pre-existing factor. This study suggested that differences in bedrock and various topographic indices should be comprehensively considered to classify pre-existing and active tectonic topography.

Development of a Method for Tracking Sandbar Formation by Weir-Gate Opening Using Multispectral Satellite Imagery in the Geumgang River, South Korea (금강에서 다분광 위성영상을 이용한 보 운영에 따른 모래톱 형성 추적 방법의 개발)

  • Cheolho Lee;Kang-Hyun Cho
    • Ecology and Resilient Infrastructure
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    • v.10 no.4
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    • pp.135-142
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    • 2023
  • A various technology of remote sensing and image analysis are applied to study landscape changes and their influencing factors in stream corridors. We developed a method to detect landscape changes over time by calculating the optical index using multispectral images taken from satellites at various time points, calculating the threshold to delineate the boundaries of water bodies, and creating binarized maps into land and water areas. This method was applied to the upstream reach of the weirs in the Geumgang River to track changes in the sandbar formed by the opening of the weir gate. First, we collected multispectral images with a resolution of 10 m × 10 m taken from the Sentinel-2 satellite at various times before and after the opening of the dam in the Geumgang River. The normalized difference water index (NDWI) was calculated using the green light and near-infrared bands from the collected images. The Otsu's threshold of NDWI calculated to delineate the boundary of the water body ranged from -0.0573 to 0.1367. The boundary of the water area determined by remote sensing matched the boundary in the actual image. A map binarized into water and land areas was created using NDWI and the Otsu's threshold. According to these results of the developed method, it was estimated that a total of 379.7 ha of new sandbar was formed by opening the three weir floodgates from 2017 to 2021 in the longitudinal range from Baekje Weir to Daecheong Dam on the Geumgang River. The landscape detection method developed in this study is evaluated as a useful method that can obtain objective results with few resources over a wide spatial and temporal range.

Evaluating Changes in Blue Carbon Storage by Analyzing Tidal Flat Areas Using Multi-Temporal Satellite Data in the Nakdong River Estuary, South Korea (다중시기 위성자료 기반 낙동강 하구 지역 갯벌 면적 분석을 통한 블루카본 저장량 변화 평가)

  • Minju Kim;Jeongwoo Park;Chang-Uk Hyun
    • Korean Journal of Remote Sensing
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    • v.40 no.2
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    • pp.191-202
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    • 2024
  • Global warming is causing abnormal climates worldwide due to the increase in greenhouse gas concentrations in the atmosphere, negatively affecting ecosystems and humanity. In response, various countries are attempting to reduce greenhouse gas emissions in numerous ways, and interest in blue carbon, carbon absorbed by coastal ecosystems, is increasing. Known to absorb carbon up to 50 times faster than green carbon, blue carbon plays a vital role in responding to climate change. Particularly, the tidal flats of South Korea, one of the world's five largest tidal flats, are valued for their rich biodiversity and exceptional carbon absorption capabilities. While previous studies on blue carbon have focused on the carbon storage and annual carbon absorption rates of tidal flats, there is a lack of research linking tidal flat area changes detected using satellite data to carbon storage. This study applied the direct difference water index to high-resolution satellite data from PlanetScope and RapidEye to analyze the area and changes of the Nakdong River estuary tidal flats over six periods between 2013 and 2023, estimating the carbon storage for each period. The analysis showed that excluding the period in 2013 with a different tidal condition, the tidal flat area changed by up to approximately 5.4% annually, ranging from about 9.38 km2 (in 2022) to about 9.89 km2 (in 2021), with carbon storage estimated between approximately 30,230.0 Mg C and 31,893.7 Mg C.

Variability of Satellite-derived Chlorophyll-a Concentration in Relation to Indian Ocean Dipole (IOD) Variation (인도양 쌍극진동 변동에 따른 위성에서 추정된 표층 클로로필-a 농도 변화 연구)

  • Son, Young Baek;Kim, Suk Hyun;Kim, Sang-Hyun;Rho, TaeKeun
    • Korean Journal of Remote Sensing
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    • v.33 no.6_1
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    • pp.917-930
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    • 2017
  • To understand the temporal and spatial variations of surface chlorophyll-a concentration (Chl-a) distribution in the Indian Ocean ($30^{\circ}E{\sim}120^{\circ}E$, $30^{\circ}S{\sim}30^{\circ}N$) by the Indian Ocean Dipole (IOD), we conducted EOF and K means analyses of monthly satellite-derived Chl-a data in the region during 1998~2016 periods. Chl-a showed low values in the central region of the Indian Ocean and relatively high values in the upwelling region and around the marginal regions of the Indian Ocean. It also had a strong seasonal variation of Chl-a, showing the lowest value in the spring and the highest value in summer due to the change of the monsoon and current system. The EOF analysis showed that Chl-a variation in EOF mode 1 is related to ENSO (El $Ni{\tilde{n}}o$/Southern Oscillation) and that of mode 2 is linked to IOD. Both modes explained spatially opposite trends of Chl-a in the east and west Indian Ocean. From K means analysis, the Chl-a variation in the east and west Indian Ocean, and around India have relatively good relationship with IOD while that in the tropical and middle Indian Ocean closely associated with ENSO. The spatial and temporal distribution of Chl-a also showed distinct spatial and temporal variations depend on the different types of IOD events. IOD classifies two patterns, which occurred during the developing ENSO (First Type IOD) and the year following ENSO event (Second Type IOD). Chl-a variation in the First Type IOD started in summer and peaked in fall around the east and west Indian Ocean. Chl-a variation in the Second Type IOD occurred started in spring, peaked in summer and fall, and disappeared in winter. In the Chl-a variation related to IOD, developing process appearing in the Chl-a difference between the east and west Indian ocean was similar. Chl-a variation in the northern Indian Ocean were opposite trend with changing developing phase of IOD.

Cerebral Activity by Motor Task in Welders Exposed to Manganese through fMRI (fMRI를 이용한 망간 노출 용접공의 운동수행에 따른 뇌 활성도 평가)

  • Choi, Jae-Ho;Jang, Bong-Ki;Lee, Jong-Wha;Hong, Eun-Ju;Lee, Myeong-Ju;Ji, Dong-Ha
    • Journal of Environmental Health Sciences
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    • v.37 no.2
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    • pp.102-112
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    • 2011
  • Objectives: The purpose of this study is to analyze the effects of chronic exposure by welders to manganese (Mn) through an analysis of the degree of brain activity in different activities such as cognition and motor activities using the neuroimaging technique of functional magnetic resonance imaging (fMRI). The neurotoxic effect that Mn has on the brain was examined as well as changes in the neuro-network in motor areas, and the usefulness of fMRI was evaluated as a tool to determine changes in brain function from occupational exposure to Mn. Methods: A survey was carried out from July 2010 to October 2010 targeting by means of a questionnaire 160 workers from the shipbuilding and other manufacturing industries. Among them, 14 welders with more than ten years of job-related exposure to Mn were recruited on a voluntary basis as an exposure group, and 13 workers from other manufacturing industries with corresponding gender and age were recruited as a control group. A questionnaire survey, a blood test, and an fMRI test were carried out with the study group as target. Results: Of 27 fMRI targets, blood Mn concentration of the exposure group was significantly higher than that of the control group (p<0.001), and Pallidal Index (PI) of the welder group was also significantly higher than that of the control group (p<0.001). As a result of the survey, the score of the exposure group in self-awareness of abnormal nerve symptoms and abnormal musculoskeletal symptoms was higher than those of the control group, and there was a significant difference between the two groups (p<0.05, respectively). In the correlation between PI and the results of blood tests, the correlation coefficient with blood Mn concentration was 0.893, revealing a significant amount of correlation (p<0.001). As for brain activity area within the control group, the right and the left areas of the superior frontal cortex showed significant activity, and the right area of superior parietal cortex, the left area of occipital cortex and cerebellum showed significant activity. Unlike the control group, the exposure group showed significant activity selectively on the right area of premotor cortex, at the center of supplementary motor area, and on the left side of superior temporal cortex. In the comparison of brain activity areas between the two groups, the exposure group showed a significantly higher activation state than did the control group in such areas as the right and the left superior parietal cortex, superior temporal cortex, and cerebellum including superior frontal cortex and the right area of premotor cortex. However, in nowhere did the control group show a more activated area than did the exposure group. Conclusions: Chronic exposure to Mn increased brain activity during implementation of hand motor tasks. In an identical task, activation increased in the premotor cortex, superior temporal cortex, and supplementary motor area. It was also discovered that brain activity increase in the frontal area and occipital area was more pronounced in the exposure group than in the control group. This result suggests that chronic exposure to Mn in the work environment affects brain activation neuro-networks.

Temporal and Spatial Variation of Polychaete Community in Kwangyang Bay, Southern Coast of Korea (광양만 다모류군집의 시.공간적 변화)

  • 신현출;고철환
    • 한국해양학회지
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    • v.25 no.4
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    • pp.205-216
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    • 1990
  • This study was carried out to investigate the composition and the distribution of the polychaete community in Kwangyang Bay during 1987-1988, and to deduce causal factors of temporal changes in community by the comparison with the results of 1982 (Choi, 1984). In the present study, the Polychaetes comprised a total of 79 species, and had a mean density of 520 ind. $.$m/SUP -2/. They showed high abundance and species diversity in the main tidal channel and the north channel of Myodo. The most abundant polychaete was Lumbrineris longifolia (28.2%), and followed by Nephtys polybranchia (16.3%) and Stermaspis scutata (8.3%). Comparing the polychaete community in summer of 1987 with that in summer of 1982, Lagis bocki and Chone teres, the most dominant species in 1982, disappeared in 1987, while Lumbrineris longifolia, Nephtys polybranchia, Terebellides horikoshii, and Sternapis scutata experienced above twice increases in densities. the community in the north channel was distinguished from those in other regions by the high abundance of L. bocki in 1982, but was similar to that of the main channel by the disappearance of L. bocki in 1987. The community in the western inner bay was similar to that of the main channel in 1982, but became to be distinguished by the disappearance of l. longifolia and the high densities of S. scutata and Tharyx sp. in 1987. The temporal change in species composition and regional difference might be induced by the combined effects in the changes of hydrologic and sedimentary environments owing to the reclamation on the delta of Seomjing River and the dredging of the north chnnel.L.bocki in the north chnnel vanished after the habitat disturbance by the reclamation and dredging.S.scutata and Tharyxsp.dominated in the western inner bay because of the accumulationfo fine sediments through weakenend durrent flow by the obstruction of a new bank constructed on the delta.

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Spatio-Temporal Changes of Beetles and Moths by Habitat Types in Agricultural Landscapes (농촌경관에서 서식지 유형에 따른 딱정벌레와 나방의 시공간적 변화 양상)

  • Kim, Nang-Hee;Choi, Sei-Woong;Lee, Jae-Seok;Lee, Jaeha;Ahn, Kee-Jeong
    • Korean Journal of Environmental Biology
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    • v.36 no.2
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    • pp.180-189
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    • 2018
  • Agricultural landscapes in Korea comprise a large cultivation area of rice paddies, other crops, and forests which surround the cropland and the farmers' residential village. The forests in this agricultural landscape play important roles as ecological corridors and refuges for plants and animals in this agroecosystem. The present study investigated the spatial and temporal diversity patterns among these components of the agroecosystem to provide baseline data that describes how fauna change in the studies system. Insect sampling was conducted at four sites in two regions, Chungcheong (Ockcheon and Geumsan) and Jeonnam (Younggwang and Haenam), from March to August of 2014, using an UV light trap for moths and five pitfall traps for beetles. Beetles comprised 225 species and 2,457 individuals in 35 families, while moths consisted of 141 species and 403 individuals in 17 families. Beetles showed higher diversity in Chungcheong than Jeonnam, while moths showed no difference in diversity between regions. Forests showed the highest number of species and individuals, followed by orchards and rice paddies. The food preference of beetles showed that forests contained a higher proportion of herbivores, while orchards and rice paddies had a higher proportion of carnivores. Temporal changes in moths in the two regions were synchronous, while those of beetles were nonsynchronous. Moths increased from spring to summer across all habitats, especially in rice paddies during summer. Beetles also increased from spring to summer in orchards and rice paddies, although the beetles in the forests increased in the middle of summer. A detailed and long-term study is needed to reveal the causes of different diversity patterns of taxa among the different habitats within the agroecosystems.

Temporal and Spatial Variation and Characteristics of Ambient Air Quality in Urban Areas in Gyeonggi Province (경기도 도시지역 환경대기질의 시공간적 추이와 특성)

  • Kim, Jong-Chan
    • Journal of Environmental Health Sciences
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    • v.38 no.3
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    • pp.269-276
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    • 2012
  • Objectives: The purpose of this study was to provide policy directions for air pollution reduction by analyzing the variation in the characteristics of air contaminants around the Gyeonggi Province area. Methods: The data used in the study was obtained from air quality monitoring stations operated by the Gyeonggi Provincial Government. The target area was the air quality management area of the Gyeonggi Province region. Results: The concentration of $PM_{10}$ (particles measuring $10{\mu}m$ or less) in 2009 was $60{\mu}g/m^3$, which has been reduced by about 2.7% per year after improvement countermeasures were emplaced. The air pollution control policy was especially more effective for coarse particulate matter (CPM, $PM_{10-2.5}$). The improvement of $NO_2$ pollution was generally very low, especially in cities which had considerable automobile traffic. The concentration of $SO_2$ pollution was rapidly improved in industrial areas, but did not show any difference for multiple and general cities. The predicted concentration of $PM_{10}$ for 2014 based on the trend over 2001-2009 was $53.4{\mu}g/m^3$, which fails to meet the target concentration of $40{\mu}g/m^3$. The predicted concentration of $NO_2$ shows a very low probability of achieving the target concentration of 22 ppb, and thus the current improvement of air quality has proven unsatisfactory. Conclusion: Air pollution control policy should be enforced according to regional pollution characteristics in order to obtain maximum effectiveness in improvement.