• Title/Summary/Keyword: geographical distributions

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Comparison of bivalves of Family Pinnidae from Southern Vietnam: A morphometric approach

  • Silina, Alla V.
    • The Korean Journal of Malacology
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    • v.27 no.4
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    • pp.345-351
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    • 2011
  • Comparison of different morphological characteristics of bivalves is very useful for distinguishing species. Therefore, this study used a morphometric approach to document patterns of phenotypic change through the specimens of family Pinnidae inhabiting the bottom sediments at the coasts of An Thoi Archipelago (south-eastern Gulf of Thailand), in that way excluding intraspecific variations among different populations along a wide geographical range. It was revealed that individuals determined as Pinna trigonium separated from specimens of Pinna nigra and Atrina vexillum at high level, but P. nigra and A. vexillum were the single species A. vexillum, as it is assumed now. Also, it was found that both groups of P. trigonium individuals and A. vexillum specimens divided into tree subgroups unified the specimens with the similar morphometric parameters: small, medium and large within the populations, though there were no evident divisions into subgroups in the size distributions of the populations. In addition to the interspecific morphological variations, the species also showed significant intraspecific morphological variations even in the same population. Most probable reason for the appearance of the intraspecific morphological variations and division of all specimens into size-specific subgroups in the population is the fact that the growth of Pinnidae bivalves is not isometric.

Analysis of Construction Plans of Rapid Charging Infrastructures based on Gas Stations in Rural Areas to Propagate Electric Vehicles (전기자동차 보급을 위한 농촌지역의 주유소 기반 급속 충전인프라 구축 방안 분석)

  • Kim, Solhee;Kim, Taegon;Suh, Kyo
    • Journal of Korean Society of Rural Planning
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    • v.21 no.1
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    • pp.19-28
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    • 2015
  • As environmental concerns including climate change drive the strong regulations for car exhaust emissions, electric vehicles attract the public eye. The purpose of this study is to identify rural areas vulnerable for charging infrastructures based on the spatial distributions of the current gas stations and provide the target dissemination rates for promoting electric cars. In addition, we develop various scenarios for finding optimal way to expand the charging infrastructures through the administrative districts data including 11,677 gas stations, the number of whole national gas stations. Gas stations for charging infrastructures are randomly selected using the Monte Carlo Simulation (MCS) method. Evaluation criteria for vulnerability assessment include five considering the characteristic of rural areas. The optimal penetration rate is determined to 21% in rural areas considering dissemination efficiency. To reduce the vulnerability, the charging systems should be strategically installed in rural areas considering geographical characteristics and regional EV demands.

Monitoring of Fish Aggregations Responding to Artificial Reefs Using a Split-beam Echo Sounder, Side-scan Sonar, and an Underwater CCTV Camera System at Suyeong Man, Busan, Korea (소너 및 수중 CCTV 카메라 시스템을 이용한 수영만 인공어초 주변에 군집한 어군의 모니터링)

  • Lee, Dae-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.3
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    • pp.266-272
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    • 2013
  • The objective of this study was to monitor and evaluate the schooling characteristics, including the distribution density (volume backscattering strength) and acoustic size (target strength), of commercially valuable species swimming in response to artificial reefs installed at Suyeong Man, Busan, Korea. Fish aggregations at two artificial reef areas and at a nearby natural rocky reef habitat were recorded and analyzed using a 70 kHz split-beam echo sounder and 330 kHz side-scan sonar from August to September, 2006. An underwater CCTV camera system was also used to observe marine organisms in physical contact with and swimming very close to artificial reefs. During the acoustic observations at three reef sites, useful information about schooling characteristics of fish aggregations responding to artificial reefs were obtained, but more trials are needed to confirm significant differences in schooling behavior and geographical distributions in areas containing natural reef structures and artificial reefs.

Wetness or Warmth, Which is the Dominant Factor for Vegetation?

  • Suzuki, Rikie;Xu, Jianqing;Motoya, Ken
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.147-149
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    • 2003
  • The wetness, a function of precipitation and temperature etc, and the warmth, a function of temperature, are the dominant factor for global vegetation distribution. This paper employs the normalized difference vegetation index (NDVI), warmth index (WAI), and wetness index (WEI), and focuses on an essential climate-vegetation relationship at global scale. The NDVI was acquired from ‘Twenty-year global 4-minute AVHRR NDVI dataset.’ The WEI is defined as the fraction of the precipitation to the potential evaporation. The WAI was calculated by accumulating the monthly mean temperature of the portion exceeded 5$^{\circ}C$ throughout the year. Meteorological data for the WEI and WAI calculation were obtained from the ISLSCP CD-ROM. All analyses were conducted for 1 ${\times}$ 1 degree grid box on the terrestrial area of the Earth, and on annual value basis averaged in 1987 and 1988. The result of analyses demonstrated that there are two regimes in their relations, that is, a regime in which NDVIs vary depending on the WEI, and a regime in which NDVIs vary depending on the WAI. These two regimes appeared to correspond to the wetness dominant and warmth dominant vegetation, respectively. The geographical distributions of two regimes were mapped. Most of the world vegetation is categorized into wetness dominant, while warmth dominant vegetation is seen in the high-latitude area mainly to the north of 60$^{\circ}$N in the Northern Hemisphere and high-altitude areas.

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Global Assessment of Current Water Resources using Total Runoff Integrating Pathways and Global GIS

  • Taikan Oki;Takao Saruhashi;Yasushi Agata;Shinjiro Kanae;Katumi Musiake
    • Proceedings of the Korea Water Resources Association Conference
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    • 2001.05a
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    • pp.67-75
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    • 2001
  • Anticipated water scarcity in the first half of this century is one of the most concerned international issues. However, even though the issue has an international impact and world wide monitoring is critical, there are limited number of global estimates at present. In this study, annual water availability was derived from annual runoff estimated by land surface models using Total Runoff Integrating Pathways (TRIP) with 0.5 degree by 0.5 degree longitude/latitude resolution globally. Global distribution of water withdrawal for each sector in the same horizontal spatial resolution was estimated based on country-base statistics of municipal water use, industrial water use, and agricultural intake, using global geographical information system with global distributions of population and irrigated crop land area. The total population under water stress estimated for 1995 corresponded very well with former estimates, however, the number is highly depend on how to assume the ratio how much water from outside of the region can be used for water resources within the region. It suggests the importance of regional studies evaluating the possibility of water intake as well as the validity of the investment for water resources withdrawal facilities.

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Effect of temperature on the development of Alphitobius diaperinus (Coleoptera: Tenebrionidae)

  • Kim, Seonghyun;Park, Haechul;Park, Ingyun;Han, Taeman;Kim, Hong Geuan
    • International Journal of Industrial Entomology and Biomaterials
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    • v.35 no.2
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    • pp.106-110
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    • 2017
  • The developmental responses of insects to temperature are important considerations in gaining a better understanding of their ecology and life histories. Temperature dependent models permit examination of the effect of temperature on the geographical distributions, population dynamics, and management of insects. The measurements of insect developmental and survival responses to temperature pose practical challenges that depend. The developmental characteristics of A. diaperinus were investigated at four temperature regimes (20, 25, 30 and $35^{\circ}C$), a relative humidity of 60%, and a light:dark photoperiod of 16:8h. The developmental time from larva to adult was 129.0, 49.8, 40.5 and 31.9 days at temperatures of 20, 25, 30 and $35^{\circ}C$, respectively. Pupal rate was 80.0%, 100%, 83.3% and 91.7% at temperatures of 20, 25, 30 and 35 respectively. There is an increasing need for a standardized manual for rearing this. Pupa had significantly lower weights at $35^{\circ}C$ than at the other temperatures. Female pupae (20mg) were significantly heavier than male (17mg).

Distribution Characteristics and Diversity of Alpine and Subalpine Plants Growing Naturally in National Parks (국립공원 내 자생하는 고산 및 아고산식물의 분포 특성과 다양성)

  • Hyun-Hee Kim;Hyeong-Jin Yoon;Jin-Won Kim
    • Journal of Environmental Science International
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    • v.33 no.6
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    • pp.367-382
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    • 2024
  • Alpine and subalpine plants are isolated and distributed in mountaintop areas at high altitudes and, are among the species most vulnerable to global warming. If the rate of warming continues at its current rate, it is highly likely that this species will be unable to find new refugia and will be the last to go extinct in their current habitats. Therefore, research on the distribution and diversity of alpine and subalpine plants is urgently needed and is important from the perspective of biodiversity conservation. Therefore, this study focused on the distribution of alpine and subalpine plants native to national parks. Alpine and subalpine plants distributed across the 12 national parks accounted for approximately half (47.78%) of all alpine plants in Korea. The average relative frequency of occurrence was 0.23, plant similarity between national parks was 37.19%, and beta diversity was 0.63. The number of species was positively correlated with the latitude, elevation, and area of the national park. Thus the geographical distributions of alpine and subalpine plants haves distinct spatial specificities and physical environmental differences.

Intraspecific variation and geographic study of Lonicera insularis (Caprifoliaceae) based on chloroplast DNA sequences (엽록체 DNA를 이용한 섬괴불나무(Lonicera insularis Nakai)의 종내변이 및 지리학적 연구)

  • Jeong, Keum Seon;Kim, Mi Sun;Lee, Woong;Pak, Jae-Hong
    • Korean Journal of Plant Taxonomy
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    • v.44 no.3
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    • pp.202-207
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    • 2014
  • Lonicera insularis Nakai (Caprifoliaceae) is Korean endemic plant that lives along the shore of Ulleungdo and Dokdo. The aim of this study is to construct a phylogenetic relationship within six species (L.maackii, L.chrysantha, L.subsessilis, L. harai, L. morrowii) of genus Lonicera L. and Wigela subsessilis as outgroup and intraspecific variation of L. insularis using chloroplast DNA five regions sequences. Sequence analysis revealed that both L. insularis and L. morrowii showed complete homologies in the intergenic regions of trnL-trnF, trnS-trnG, psbM-trnD and matK coding region. However, sequence in the petN-psbM intergenic region showed a single nucleotide difference between both species, thus we designated them as CP01 and CP02. The plants having CP01 are prevalent in the Ulleungdo and Dokdo, while L. insularis and L. morrowii from Ulleungdo and of Dokdo, and Japan have CP02. This confirmed the existence of two cp DNA lineages with different geographical distributions. We can infer the allopatric speciation by geographical barrier. The result will provide the important basal data to study speciation and specie evolution of ocean islands such as Ulleungdo and Dokdo.

Reviews in Medical Geography: Spatial Epidemiology of Vector-Borne Diseases (벡터매개 질병(vector-borne diseases) 공간역학을 중심으로 한 보건지리학의 최근 연구)

  • Park, Sunyurp;Han, Daikwon
    • Journal of the Korean Geographical Society
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    • v.47 no.5
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    • pp.677-699
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    • 2012
  • Climate changes may cause substantial changes in spatial patterns and distribution of vector-borne diseases (VBD's), which will result in a significant threat to humans and emerge as an important public health problem that the international society needs to solve. As global warming becomes widespread and the Korean peninsula characterizes subtropical climate, the potentials of climate-driven disease outbreaks and spread rapidly increase with changes in land use, population distributions, and ecological environments. Vector-borne diseases are typically infected by insects such as mosquitoes and ticks, and infected hosts and vectors increased dramatically as the habitat ranges of the VBD agents have been expanded for the past 20 years. Medical geography integrates and processes a wide range of public health data and indicators at both local and regional levels, and ultimately helps researchers identify spatiotemporal mechanism of the diseases determining interactions and relationships between spatial and non-spatial data. Spatial epidemiology is a new and emerging area of medical geography integrating geospatial sciences, environmental sciences, and epidemiology to further uncover human health-environment relationships. An introduction of GIS-based disease monitoring system to the public health surveillance system is among the important future research agenda that medical geography can significantly contribute to. Particularly, real-time monitoring methods, early-warning systems, and spatial forecasting of VBD factors will be key research fields to understand the dynamics of VBD's.

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GIS-Based Methods to Assess the Population Distribution Criteria for Undesirable Facilities: The Case of Nuclear Power Plants (비선호 시설의 인구분포 관련 입지기준 평가를 위한 GIS-기반 방법론 연구 -원자력 발전소의 경우-)

  • Lee, Sang-Il;Cho, Daeheon
    • Journal of the Korean Geographical Society
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    • v.47 no.5
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    • pp.755-774
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    • 2012
  • The main objective of the study is to propose GIS-based methods to assess the population distribution criteria for undesirable facilities such as nuclear power plants. First of all, a review of the relevant criteria was conducted for the official documents compiled by such institutions as IAEA (International Atomic Energy Agency), U.S. NRC (Nuclear Regulatory Commission), and some national institutes including the Korea Institute of Nuclear Safety. It is informed from the review that the fundamental principle underlying the various criteria is to maximize the distance between a plant and the nearest population center. It is realized that two interrelated GIS-based techniques need to be devised to put the principle into practice; sophisticated ways of representing population distribution and identifying population centers. A dasymetric areal interpolation is proposed for the former and cell-based and area-based critical density methods are introduced. Grid-based population distributions at various spatial resolutions are created by means of the dasymetric areal interpolation. By applying the critical density methods to the gridded population distribution, some population centers satisfying the population size and density criteria can be identified. These methods were applied to the case of the Gori-1 nuclear power plant and their strengths and limitations were discussed. It was revealed that the assessment results could vary depending upon which method was employed and what values were chosen for various parameters. This study is expected to contribute to foster the applications of methods and techniques developed in geospatial analysis and modeling to the site selection and evaluation.

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