• Title/Summary/Keyword: geographic distance

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Identifying Urban Spatial Structure through GIS and Remote Sensing Data -The Case of Daegu Metropolitan Area- (지리정보시스템과 원격탐사자료를 이용한 도시공간구조의 파악 -대구광역권 사례연구-)

  • Kim, Jae-Ik;Kwon, Jin-Hwi
    • Journal of the Korean Association of Geographic Information Studies
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    • v.12 no.2
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    • pp.44-51
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    • 2009
  • The main purpose of this study is to identify urban spatial structure by applying geographic information system and remote sensing data. This study identifies the urban spatial structure of non-megalopolis by analyzing the spatial distribution of population and employment in the case of Daegu metropolitan area. For this purpose, multi-temporal satellite image data (Landsat TM; 1995, 2000 and 2005) were utilized through the geographic information system. The distance-decay estimations in terms of population and employment density show that Daegu region as a whole shows monocentric urban characteristics. However, some evidences of polycentricism such as low explanation power of monocentric urban model, rises in multiple employment centers, decentralization of employment are emerging.

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Determining the Location of Urban Health Sub-center According to Geographic Accessibility (지리적 접근성을 이용한 도시지역 보건지소의 입지선정)

  • Lee, Kun-Sei;Kim, Chang-Yup;Kim, Yong-Ik;Shin, Young-Soo
    • Journal of Preventive Medicine and Public Health
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    • v.29 no.2 s.53
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    • pp.215-225
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    • 1996
  • Decentralization to local governments and amending of Health Center Law are to promote the efforts of health planning at the level of local agencies. In the health facility planning, it is important to take into account that what to be built, where to be located, how far should be service area and so forth, because health facilities are immovable, and require capital as well as personnel and consumable supplies. The aim of our study, answering to the question of 'where to be located?', is to determine the best location of urban health sub-center. At the local level, planning is the matter of finding the best location of specific facilitiy, in relation to population needs. We confine the accessibility, which is basic to location planning, to geographic one. Location-Allocation Model is used to solve the problem where the location is to maximize geographic accessibility. To minimize the weighted travel distance, objective function, $R_k=\sum{\sum}a_{ij}w_{i}d_{ij}$ is used. Distances are measured indirectly by map measure-meter with 1:25,000 Suwon map, and each potential sites, 10 administrative Dongs in Kwonson Gu, Suwon, are weighted by each number of households, total population, maternal age group, child age group, old age group, Relief for the livelihood, and population/primary health clinics. We find that Kuwoon-Dong, Seodun-Dong, Seryu3-Dong, according the descending orders, are best sites which can minimize the weighted distance, and conclude that it is reasonable to determine the location of urban health sub-center among those sites.

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Geographic variation in the acoustic signals of black-billed magpies (Pica pica) in South Korea and Japan

  • Lee, Sang-Im;Lee, Sun-Hee;Nam, Hyun-Young;Choe, Jae-Chun
    • Journal of Ecology and Environment
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    • v.34 no.2
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    • pp.167-174
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    • 2011
  • Black-billed magpies (Pica pica) are a highly sedentary species due to their short and round wings, which are not adequate for long distance flights. We investigated geographic variation in the vocal signals of magpies residing in South Korea and Japan (subspecies sericea). Based on the magpie's limited dispersal ability, we predicted that the variation in vocal signals of black-billed magpies could be explained by geographic barriers such as mountain ranges and straits. We analyzed four-syllable chatter calls of magpies from five localities in South Korea, which are separated by mountain ranges (Seoul, Daejeon, Daegu, Gwangju, and Busan), and two island localities separated from the mainland by straits (Jeju in Korea and Saga in Japan). We found significant differences in the characteristics of magpie chatter calls recorded in the seven localities, and the variation pattern was independent among the variables. Mainland-island differentiation and north-south differentiation were observed. In general, magpies on Saga were the most distinctive. North-south differentiation was observed among the Korean mainland localities. However, the pattern was not related to the presence of putative geographic barriers. We hypothesize that the patterns of geographic variation in the structure of magpie chatter calls residing in South Korea might have been shaped by a sudden expansion of magpies followed by low level of local isolation, which may have led to vocal differentiation. Along with elucidating the vocal environment of Korean magpie populations, more extensive sampling is needed to clarify the functional aspects of geographic variation in the vocal signals of Korean magpies.

Establishment of Equi-Distance River Cross Section and Finite Element Mesh Using ArcView and Observed Cross Section (ArcView와 실측단면을 이용한 등간격 하도단면 및 유한요소망 구축)

  • Choi, Seung-Yong;Han, Kun-Yeun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.12 no.4
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    • pp.95-112
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    • 2009
  • The river cross section in the input/output data which are needed in the area of river flow analysis is very important factor. The bottom elevation of actual river cross section has to be correctly reflected to obtain correct results when two dimensional flow analysis is conducted for natural river. But to reflect virtually the bottom elevation of river cross section is impossible. The objective of this study is to suggest a method for creating equi-distance river cross section by using both HEC section and ArcView and constructing the finite element mesh. The main channels of Han and Nakdong river were selected and equi-distance river cross sections constructed in this study have shown good agreement with the observed river cross sections. In addition, high quality finite element meshes can be applied to many areas of study such as finite element analysis for water quality and two dimensional flow analysis using the suggested method for equi-distance river cross sections in this study.

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The Seasonal Variation of Free Chlorine Residuals by Water Supply Distance in Daegu (대구 지역의 계절 변화에 따른 급수관내 잔류염소 농도 거동)

  • Lee, Tae-Gwan
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.3
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    • pp.363-369
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    • 2005
  • This paper presents the integrated technique of water quality analysis and Geographic Information System(GIS) for assessing the variation of free chlorine residuals by water temperature and supply distance in Sangri water supply system in Daegu. GIS was utilized for mapping projectmap, extraction of a pipeline route, and supply distance. Free chlorine residual is analyzed every month for appraising the seasonal variation. As a result, free chlorine residuals are affected both water temperature and water supply distance, and it becomes worse as water temperature and water supply distance is increased. To maintain 0.4mg/l of free chlorine residual, initial dose concentration should be over 1.85mg/l in summer.

Geographic Variation of Granulilittorina exigua (Littorinidae, Gastropoda) in Korea Based on the Mitochondrial Cytochrome b Gene Sequence

  • Song, Jun-Im;Suh, Jae-Hwa;Kim, Sook-Jung
    • Animal cells and systems
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    • v.4 no.3
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    • pp.267-272
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    • 2000
  • Partial sequence of the mitochondrial cytochrome b gene was analyzed to investigate genetic variation from 10 geographic populations of Granulilittorina exigua in Korea. The sequence of 282 base pairs was determined by PCR-directed silver sequencing method. The sequences of two species within the genus Littorina reserved in NIH blast search were utilized to determine geographic variations of species referred. The levels of mtDNA sequence differences were 0.00-2.54% within populations and 0.71-4.43% between populations. There were four amino acid differences between representative species of the genera Granulilittorina and Littorina, but no differences within populations of the genus Granulilittorina. The UPGMA and the N-J trees based on Tamura-Nei genetic distance matrix were constructed, which showed that the genus Granulilittorina was divided into three groups such as eastern (even exception for Tokdo population), southern, and western regional populations. The degrees of genetic divergence within populations of each group were p=0.021, p=0.019, and p=0.018, respectively. The divergence between the eastern and southern populations was p=0.032, showing closer relationship than with the western populations (p=0.052). Based on the diverged time estimation, the eastern and southern populations of Granulilittorina exigua in Korea diverged from the western populations about 2.1 MYBP, and the eastern and southern populations diverged from each other about 1.3 MYBP.

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Locational Characteristics of Highly Pathogenic Avian Influenza(HPAI) Outbreak Farm (고병원성 조류인플루엔자(HPAI) 발생농가 입지특성)

  • KIM, Dong-Hyeon;BAE, Sun-Hak
    • Journal of the Korean Association of Geographic Information Studies
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    • v.23 no.4
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    • pp.140-155
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    • 2020
  • This study was conducted to identify the location characteristics of infected farms in the areas where livestock diseases were clustered(southern Gyeonggi-do and Chungcheong-do), analyze the probability of disease occurrence in poultry farms, find out the areas corresponding to the conditions, and use them as the basis for prevention of livestock diseases, selection of discriminatory prevention zones, and establishment of prevention strategies and as the basic data for complementary measures. The increase of one poultry farm within a radius of 3-kilometers increases the risk of HPAI infection by 10.9% compared to the previous situation. The increase of 1m in distance from major roads with two lanes or more reduces the probability of HPAI infection by 0.001% compared to the previous situation. If the distance of the poultry farm located with 15 kilometers from a major migratory bird habitat increases by 15 to 30 kilometers, the chance of infection with HPAI is reduced by 46.0%. And if the distance of the same poultry farm increase by more than 30 kilometers, the chances of HPAI infection are reduced by 88.5%. Based on the results of logistic regression, the predicted probability was generated and the actual area of the location condition with 'more than 15 poultry farms within 3km a radius of, within 1km distance from major roads, and within 30km distance from major migratory birds habitat was determined and the infection rate was measured. It is expected that the results of this study will be used as basic data for preparing the data and supplementary measures when the quarantine authorities establish discriminatory quarantine areas and prevention strategies, such as preventive measures for the target areas and farms, or control of vehicles, by identifying the areas where livestock diseases are likely to occur in the region.

A Spatial Statistical Approach to the Delimitation of CBD (도심경계설정을 위한 공간통계학적 접근)

  • Kim, Ho-Yong;Kim, Ji-Sook;Lee, Sung-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.4
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    • pp.42-54
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    • 2012
  • The main purpose of this study is to suggest the spatial statistical approach suitable for the delimitation of Busan CBD. For this purpose, Getis-Ord $G_i^*$ and both of IDW (Inverse Distance Weight) and FDB(Fixed Distance Band) were applied to delimit the CBD boundary. And then, the results of the CBD boundary were compared and verified with the methodologies of the previous studies. The result of IDW accorded with the previous study relating to the delimitation of the boundary of CBD, and the result of FDB was reflecting the characteristics of the mixed-use residential of a transition zone. As a result of the land use quotient, the mixed land use of residential and commercial was highly specialized in the boundary of FDB. These results will be able to support the understanding of urban spatial structure and the effective CBD management.

Analysing Potential Improvement of Public Transit Services in OD Level Using Time-Distance Accessibility and Smartcard Traffic Volume (시간거리 접근성과 교통카드 기반 통행량을 이용한 OD별 잠재적 대중교통 서비스 개선량 분석)

  • YANG, Hyun-Jae;NAM, Hyun-Woo;JUN, Chul-Min
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.2
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    • pp.80-93
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    • 2018
  • Public transit services are generally analyzed based on the correlation of demand and supply. The computation of supply uses accessibility while demand uses travel demands estimation based on residential population. However, the traditional demand estimation has a limitation in analysing in micro-scale compared to the smartcard data traffic. This study analyzed potential improvement of public transit services using smartcard traffic data. The supply of transportation was defined using time distance accessibility. Also, time loss was calculated in those origin destination(OD) pairs where time distance accessibilities are relatively low. The proposed method was applied at Seoul. The results showed that the areas where OD pairs need improvement include Seodaemun-gu, Guro-gu and Nowon-gu.

Study about the Applicable Plan of GIS on Range of Magnetic Field Emitted from 60 Hz Powerline (60Hz 고압 송전선로의 자기장 발생범위에 대한 GIS 적용 방안에 대한 연구)

  • Hong, Seung Cheol;Choi, Seong Ho;Kim, Yoon Shin;Park, Jae Young
    • Journal of Environmental Impact Assessment
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    • v.15 no.4
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    • pp.271-277
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    • 2006
  • In this study, we investigated the applicable plan of GIS on the environmental impact assessment of 60 Hz Powerline. So we assessed distance data based on calculations by use of 2D and 3D Geographical information systems(GIS) and distance data based on measurements on 1: 5000 maps accord with on site distance measurements to use input data for calculating magnetic field. One hundred eight of the on site measured addresses were selected from residences. The data were achieved by measuring the distance between residence and power line on maps with scales of 1: 5000. The digital map was obtained from National Geographic Information Institute with scales of 1: 5000, and we made 2D and 3D map. Correlation analyses were performed for statistical analyses. For the 3D GIS versus on site comparison of different exposure categories, 70 of 108 measurements were assigned to the correct category. Similarly for 2D GIS versus on site comparison, 71 of 108 were correctly categorized. When comparing map measurement with on site measurement, 62 of 108 were correctly categorized. When the correlation analysis was performed, best correlation was found between 3D GIS and on site measurements with r = 0.84947 (p<0.0001). The correlation between map and on site measurement yielded an r of 0.76517 (p<0.0001). Since the GIS measurements and map measurement were made from the center point in the building and the on site measurements had to be made from the closest wall on the building, this might introduce and additional error in urban areas. The difference between 2D and 3D calculations were resulted from the height of buildings.