• Title, Summary, Keyword: geographic distribution

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A Geographic Distributed Hash Table for Virtual Geographic Routing in MANET (MANET에서 가상 위치 기반 라우팅을 위한 지역 분산 해쉬 테이블 적용 방법)

  • Ko, Seok-Kap;Kim, Young-Han
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.12
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    • pp.58-65
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    • 2008
  • This paper presents a new geographic distributed hash table (GDHT) for MANETs or Mesh networks, where virtual geographic protocol is used. In previous wort GDHT is applied to a network scenario based on two dimensional Cartesian coordinate system. Further, logical data space is supposed to be uniformly distributed. However, mobile node distribution in a network using virtual geographic routing is not matched to data distribution in GDHT. Therefore, if we apply previous GDHT to a virtual geographic routing network, lots of DHT data are probably located at boundary nodes of the network or specific nodes, resulting in long average-delay to discover resource (or service). Additionally, in BVR(Beacon Vector Routing) or LCR(Logical Coordinate Routing), because there is correlation between coordinate elements, we cannot use normal hash function. For this reason, we propose to use "geographic hash function" for GDHT that matches data distribution to node distribution and considers correlation between coordinate elements. We also show that the proposed scheme improves resource discovery efficiently.

A Quantitative Analysis of the Spatial Agglomeration Pattern among the Korean Cities (한국 도시들의 공간집적 패턴에 대한 계량분석)

  • Sohn, Jungyul
    • Journal of the Korean Geographical Society
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    • v.48 no.1
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    • pp.56-71
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    • 2013
  • The purpose of this study is to examine the spatial distributional characteristics of industries among the Korean cities and to conduct industry classification using the findings. For this purpose, 82 cities in Korea are investigated with respect to 15 industrial sectors. In the analysis, concentration of and association between industries are recognized using both geographic and non-geographic measures. In order to measure concentration and association, locational Gini coefficient, Moran's I, correlation coefficient, and bivatiate Moran are used and 15 industrial sectors are classified based on these estimates. The findings reveal that the chemical sector shows strong geographic and non-geographic concentrations while the assembly, machinery and electronics sector only shows a strong geographic concentration. Printing and publishing, wholesale, and business services show a strong non-geographic association with other sectors. The remaining ten sectors show no explicit distribution patterns among cities. This study contributes to providing the methodology that analyzes the spatial distribution patterns of industries in a comprehensive way and is able to provide useful information in implementing industrial location policies including industrial clusters.

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Geographic Analysis of Neurosurgery Workforce in Korea

  • Park, Hye Ran;Park, Sukh Que;Kim, Jae Hyun;Hwang, Jae Chan;Lee, Gwang Soo;Chang, Jae-Chil
    • Journal of Korean Neurosurgical Society
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    • v.61 no.1
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    • pp.105-113
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    • 2018
  • Objective : In respect of the health and safety of the public, universal access to health care is an issue of the greatest importance. The geographic distribution of doctors is one of the important factors contributing to access to health care. The aim of this study is to assess the imbalances in the geographic distribution of neurosurgeons across Korea. Methods : Population data was obtained from the National Statistical Office. We classified geographic groups into 7 metropolitan cities, 78 non-metropolitan cities, and 77 rural areas. The number of doctors and neurosurgeons per 100000 populations in each county unit was calculated using the total number of doctors and neurosurgeons at the country level from 2009 to 2015. The density levels of neurosurgeon and doctor were calculated and depicted in maps. Results : Between 2009 and 2015, the number of neurosurgeons increased from 2002 to 2557, and the ratio of neurosurgeons per 100000 populations increased from 4.02 to 4.96. The number of neurosurgeons per 100000 populations was highest in metropolitan cities and lowest in rural areas from 2009 to 2015. A comparison of the geographic distribution of neurosurgeons in 2009 and 2015 showed an increase in the regional gap. The neurosurgeon density was affected by country unit characteristics (p=0.000). Conclusion : Distribution of neurosurgeons throughout Korea is uneven. Neurosurgeons are being increasingly concentrated in a limited number of metropolitan cities. This phenomenon will need to be accounted when planning for a supply of neurosurgeons, allocation of resources and manpower, and the provision of regional neurosurgical services.

Shifts of Geographic Distribution of Pinus koraiensis Based on Climate Change Scenarios and GARP Model (GARP 모형과 기후변화 시나리오에 따른 잣나무의 지리적 분포 변화)

  • Chun, Jung Hwa;Lee, Chang Bae;Yoo, So Min
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.4
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    • pp.348-357
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    • 2015
  • The main purpose of this study is to understand the potential geographic distribution of P. koraiensis, which is known to be one of major economic tree species, based on the RCP (Representative Concentration Pathway) 8.5 scenarios and current geographic distribution from National Forest Inventory(NFI) data using ecological niche modeling. P. koraiensis abundance data extracted from NFI were utilized to estimate current geographic distribution. Also, GARP (Genetic Algorithm for Rule-set Production) model, one of the ecological niche models, was applied to estimate potential geographic distribution and to project future changes. Environmental explanatory variables showing Area Under Curve (AUC) value bigger than 0.6 were selected and constructed into the final model by running the model for each of the 27 variables. The results of the model validation which was performed based on confusion matrix statistics, showed quite high suitability. Currently P. koraiensis is distributed widely from 300m to 1,200m in altitude and from south to north as a result of national greening project in 1970s although major populations are found in elevated and northern area. The results of this study were successful in showing the current distribution of P. koraiensis and projecting their future changes. Future model for P. koraiensis suggest large areas predicted under current climate conditions may be contracted by 2090s showing dramatic habitat loss. Considering the increasing status of atmospheric $CO_2$ and air temperature in Korea, P. koraiensis seems to experience the significant decrease of potential distribution range in the future. The final model in this study may be used to identify climate change impacts on distribution of P. koraiensis in Korea, and a deeper understanding of its correlation may be helpful when planning afforestation strategies.

Geographic Information System for Developing Advanced Distribution Management System (차세대 배전지능화시스템 개발을 위한 지리정보시스템 적용)

  • Kim, DongWook;Cho, SungHo;Seo, Hojin;Park, YoungBae
    • KEPCO Journal on Electric Power and Energy
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    • v.5 no.2
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    • pp.67-74
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    • 2019
  • Recently, as the renewable distributed energy resources has increased, the variability within the electrical power distribution system has increased, so that there is a growing concern about the stable electrical power distribution system. For efficient management of future electrical power distribution system, it is necessary to improve the electrical power distribution system operation using new visualization technology. In this paper, we describe the current status of GIS introduction and related technology trends in the field of electrical power distribution, and analyze the necessity of GIS system for electrical power distribution system operation and problems to be solved when introducing GIS technology.

A Study on the Preparation Method of Fruit Cropping Distribution Map using Satellite Images and GIS (위성영상과 GIS를 이용한 과수재배 분포도 작성 기법에 관한 연구)

  • Jo, Myung-Hee;Bu, Ki-Dong;Lee, Jung-Hyoup;Lee, Kwang-Jae
    • Journal of the Korean Association of Geographic Information Studies
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    • v.3 no.4
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    • pp.73-86
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    • 2000
  • This study focused on extracting an efficient method in the fruit cropping distribution mapping with various classification methods using multi-temporal satellite images and Geographic Information Systems(GIS). For this study, multi-temporal Landsat TM images, in observation data and existing fruit cropping area statistics were used to compare and analyze the properties of fruit cropping and seasonal distribution per classification method. As a result, this study concludes that Maximum Likelihood Method with earlier autumn satellite image was most efficient for the fruit cropping mapping using Landsat TM image. In addition, it was clarified that cropping area per administrative boundary was prepared and distribution pattern was identified efficiently using GIS spatial analysis.

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Geographic Distribution and Epidemiology of Lung Cancer During 2011 in Zhejiang Province of China

  • Lin, Xia-Lu;Chen, Yan;Gong, Wei-Wei;Wu, Zhao-Fan;Zou, Bao-Bo;Zhao, Jin-Shun;Gu, Hua;Jiang, Jian-Min
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.13
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    • pp.5299-5303
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    • 2014
  • Background: To explore etiology for providing scientific clues for the prevention of lung cancer. Materials and Methods: Data for lung cancer incidence and meteorological geographic factors from 25 counties in Zhejiang province of China during 2011 were studied. Stepwise multiple regression and correlation analysis were performed to analyze the geographic distribution and epidemiology of lung cancer. Results: 8,291 new cases (5,998 in males and 2,293 females) of lung cancer during 2011 in Zhejiang province were reported in the 25 studied counties. Reported and standardized incidence rates for lung cancer were 58.0 and 47.0 per 100,000 population, respectively. The incidence of lung cancer increased with age. Geographic distribution analysis shows that the standardized incidence rates of lung cancer in northeastern Zhejiang province were higher than in the southwestern part, such as in Nanhu, Fuyang, Wuxing and Yuyao counties, where the rates were more than 50 per 100,000 population. In the southwestern Zhejiang province, for instance, in Yueqing, Xianju and Jiande counties, the standardized incidence rates of lung cancer were lower than 37 per 100,000 population. Spearman correlation tests showed that forest coverage rate, air quality index (AQI), and annual precipitation level are associated with the incidence of lung cancer. Conclusions: Lung cancer in Zhejiang province shows obvious regional differences. High incidence appears associated with low forest coverage rate, poor air quality and low annual precipitation. Therefore, increasing the forest coverage rate and controlling air pollution may play an important role in lung cancer prevention.

Classification , Distribution and Geographic Variation of Two Species of the Genus Moroco in Korea (한국산 버들치속(Genus Moroco) 어류 2 종의 분류.분포 및 지리적 변이에 관하여)

  • 민미숙;양서영
    • Animal Systematics, Evolution and Diversity
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    • v.2 no.1
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    • pp.63-78
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    • 1986
  • Two species of Moroco oxycephalus and M. lagowskii were studied to examine patterns of genic variation and morphological difference within and between populations of two species, and to clarify their taxonomic status and geographic distribution. The number of scales above lateral line(SAL) was the key character to classify these species. On the average, M.lagowskii had 22 or more SAL whereas M.oxycephalus had 20 or less. Previously known character of the position of dorsal fin was found to be not appropriate to distinguish them. Five loci, Gp, st-1, Est-2, Est-3 and Got-1 , showed fixed difference electrophoretically between two species and these could be used as genetic markers to identify them. The degree of genic variation of M. oxycephalus was four fold higher(H=0.032) than that of M. lagowskii(H=0.008) but both species were far less than the average genic variation of freshwater fish in general. Rogers' genetic similarity coefficients between two species were S=0.692 and their presumed divergent time was estimated to be sbout 1.8million years ageo. Detailed survey of the geographic distribution of thses revealed that M.lagowskii was distributed in northeastern part of South Korea(Ganseong , Gangreung, Wangsan, and Oggye) and M. oxycephalus was occupied rest of the peninsula. The distrance between Oggye, the southern limit of M. lagowskii distribution , and Samwha (near Samcheog), the northern limit of M.oxycephalus, was aobut 15 Km apart and no symparty was found in between.

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A Study on the Implementation of Geographic Information System for an Intelligent Power Distribution Network with Location Informations of Power Line Communication-based Automatic Meter Reading System (전력선통신 기반 저압원격검침 시스템의 공간 정보를 활용한 지능형 배전망 지리정보시스템 구축에 관한 연구)

  • Seo, Chung-Ki;Lee, Seung-Gol
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.3
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    • pp.365-369
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    • 2015
  • In this paper, geographic information system(GIS) for an intelligent power distribution network was implemented with location informations acquired from automatic meter reading system, where the location informations of power line communication(PLC) modems installed at customer side were collected at data concentration units(DCUs) of headend equipment via PLC and then were transmitted to front end processor server. By displaying the connection status of the power distribution network on GIS map, operation of advanced metering infrastructure(AMI) or management of power grid system could be performed intuitionally and in real time, because the configuration state of the power grid could be easily monitored. The feasibility of the proposed system was confirmed with the especially constructed laboratory-level test bed and the verification test of the system will be carried out for a real power distribution network.

Diversity and Geographic Distribution of Anti-cancer Higher Fungi in Korea

  • Cho, Duck-Hyun
    • Korean Journal of Plant Resources
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    • v.11
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    • pp.51-79
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    • 1998
  • Many higher fungi were collected at Korea from 1976 to 1998. They were identified and surveyed on resources with many reference books. According to the results, fungal fungi were 40 families, 90 general and 215 species. Among them , anti-cancer resources used in Korea were Ganoderma lucidum, Phellinus linteus, Agaricus brazei and Cordyceps militaris. Three species exception Agaricus brazei were distributed in Korea. All these are cultivated in Korea.

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