• Title/Summary/Keyword: Geographic variation

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The Relationship Between Phytoplankton Distribution and Environmental Conditions of the Upwelling Cold Water in the Eastern Coast of the Korean Peninsula (동해남부연안 냉수대 변동과 관련된 해양환경 및 식물플랑크톤의 변동 특성)

  • Oh, Hyun Ju;Suh, Young Sang;Heo, Seung
    • Journal of the Korean Association of Geographic Information Studies
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    • v.7 no.4
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    • pp.166-173
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    • 2004
  • By analyzing the sea surface temperature (SST), phytoplankton and NOAA/AVHRR satellite data of Gijang, located at the eastern coast of the korean peninsula during the period of 2001 to 2003, we have analyzed the daily variation in the upwelling cold water, phytoplankton, and chlorophyll a. The SST of Gijang coast appealed rapid change due to the temporal and spatial variation of the upwelling cold water. This in turn led to an increase in the number of phytoplanktons and other varieties of organisms inhabiting in the Gijang coastal region.

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Mitochondrial DNA Sequence Variation of the Tiny Dragonfly, Nannophya pygmaea(Odonata: Libellulidae)

  • Kim, Ki-Gyoung;Jang, Sang-Kyun;Park, Dong-Woo;Hong, Mee-Yeon;Oh, Kyoung-Hee;Kim, Kee-Young;Hwang, Jae-Sam;Han, Yeon-Soo;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.15 no.1
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    • pp.47-58
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    • 2007
  • The tiny dragonfly, Nannophya pygmaea(Odonata: Libellulidae) is one the smallest dragonflies in the world and listed as a second-degree endangered wild animal and plant in Korea. For the long-term conservation of such endangered species, an investigation on nation-wide genetic magnitude and nature of genetic diversity is required as a part of conservation strategy. We, thus, sequenced a portion of mitochondrial COI gene, corresponding to "DNA Barcode" region(658 bp) from 68 N. pygmaea individuals collected over six habitats in Korea. The sequence data were used to investigate genetic diversity within populations and species, geographic variation within species, phylogeographic relationship among populations, and phylogenetic relationship among haplotypes. Phylogenetic analysis and uncorrected pairwise distance estimate showed overall low genetic diversity within species. Regionally, populations in southern localities such as Gangjin and Gokseong in Jeollanamdo Province showed somewhat higher genetic diversity estimates than those of remaining regions in Korean peninsula. Although geographic populations of N. pygmaea were subdivided into two groups, distance- or region-based geographic partition was not observed.

Development of Estimation Method for Velocity Pressure Exposure Coefficient of Buildings Based on Spatial Information (공간정보기반 건축물의 풍속고도분포계수 산정 방법 개발)

  • SEO, Eun-Su;CHOI, Se-Hyu
    • Journal of the Korean Association of Geographic Information Studies
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    • v.20 no.2
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    • pp.32-46
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    • 2017
  • Recent rapid urban expansion and crowding of various industrial facilities has affected the features of a significant part of downtown area, resulting in areas having buildings with a wide range of height and the foothills. To compute a velocity pressure exposure coefficient, namely the design wind speed factor, this study defines ground surface roughness by utilizing concentration analysis for the height of each building. After obtaining spatial data by extracting a building layer from digital maps, the study area was partitioned for the concentration analysis and to allow investigation of the frequency distribution of building heights. Concentration analysis by building height was determined with the Variation-to-Means Ratio (VMR) and Poisson distribution analysis using a buildings distribution chart, with statistical significance determined using Chi-square verification. Applying geographic information systems (GIS) with the architectural information made it possible to estimate a velocity pressure exposure coefficient factor more quantitatively and objectively, by including geographic features, as compared to current methods. Thus, this method is expected to eliminate inaccuracies that arise when building designers calculate the velocity pressure exposure coefficient in subjective way, and to help increase the wind resistance of buildings in a more logical and cost-effective way.

: I. An Analysis on Striped Field Mice, Apodemus agrarius coreae Thomas, from Cheongju

  • Koh, Hung-Sun
    • The Korean Journal of Zoology
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    • v.26 no.2
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    • pp.123-134
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    • 1983
  • Age variation and secondary sexual dimorphism in four external and 27 cranial characters of 102 specimens of striped firld mice, Apodemus agrarius coreae Thomas, from Cheongju, Korea, were analyzed statistically. Specimens were classified as subadults, young adults, middle-aged adults, and old adults, and variation of morphometric characters among the four age classes was evident. Significant secondary sexual dimorphism among sexes of the same age class was not revealed. Teh specimens of the same age class have to be used in further analyses to clarify geographic variation of morphometric characters in Apodemus agrarius from Korea.

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: I. Geographic Variation of Morphometric Characters in Striped Field Mice, Apodemus agrarius coreae Thomas (한국산 설치류의 계통분류학적 연구 1.등줄쥐, Apodemus agrarius coreae Thomas 의 형태적 형질의 지리적 변이)

  • Koh, Hung-Sun
    • The Korean Journal of Zoology
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    • v.28 no.1
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    • pp.9-20
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    • 1985
  • Univariate and multivariate analyses of morphometric characters were performed with samples of striped field mice, Apodemus agrarius coreae Thomas, collected from Mt. Taebaek area, Mt. Wolak area, Mt. Palgong area, and Chongju area. It was confirmed that the samples of A. agrarius coreae were similar with one another to be grouped into a single subspecies. Moreover, clinal variation related with the altitude of localities where samples were collected was revealed in the first axis resulted from discriminant analysis and in the length of tail vertebrae.

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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.

Current Status of Taeniasis in Thailand

  • Anantaphruti, Malinee Thairungroj
    • Parasites, Hosts and Diseases
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    • v.51 no.1
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    • pp.37-42
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    • 2013
  • Taeniasis is prevalent in all regions of Thailand, except the South. Infections were more frequently found in males than females of any age from 7-83 years. Taenia saginata is the most common species throughout the country. Taenia asiatica was reported only in the province of Kanchanaburi in the Central region. Co-infections, with Taenia solium and T. asiatica or T. solium and T. saginata, were found. Hybridization between T. asiatica and T. saginata is evidence that co-infection is never found between these 2 species. Finding more than 1 worm in a single patient was not entirely rare. Genetic variation was found without correlation to its geographic distribution in T. saginata, whereas no variation was found in T. asiatica.

A Comparison of Spatio-Temporal Variation Pattern of Sea Surface Temperature According to the Regional Scale in the South Sea of Korea (지역 규모에 따른 한국 남부해역 표층수온의 시·공간적 변동 패턴 비교)

  • Yoon, Dong-Young;Choi, Hyun-Woo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.4
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    • pp.182-193
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    • 2011
  • In order to compare the spatio-temporal variation pattern of sea surface temperature (SST) in Korea's Southern areas of the sea according to a regional scale, this study has selected the winter and summer seasons for 31 years (1980~2010) in a period aspect and selected three areas of the sea such as the Western areas of the sea (region B) and Eastern areas of the sea (region C) around Jeju Island in addition to overall Southern areas of the sea (region A) in regional aspect. The regression analysis was applied to find out a temporal variation pattern of SST, and the weighted mean center (WMC) of SST as well as analysis of a standard deviational ellipse (SDE) was respectively applied. As a result of regression analysis of SST, it showed a rising long-term trend for all two seasons in three regions. However, though the average SST for 31 years was all similar in three regions in the summer season, the region C appeared more highly than region B in the winter season. The spatial variation pattern of SST for two seasons showed that it is respectively different from each other in three regions. The spatial variation pattern of SST appeared as E-W direction in region A, SE-NW direction in region B and SW-NE direction in region C. In addition, the relationship between the location of the WMC of SST and the average SST showed correlation in regions A and B in the winter season, whereas it appeared that there is no correlation in region C. Accordingly, it can be known that the regional scale should be considered in case of analysis of spatio-temporal variation patterns of SST.

A Spatio-Temporal Variation Pattern of Oiling Status Using Spatial Analysis in Mallipo Beach of Korea (공간분석 기법을 이용한 만리포 유분의 시·공간 변동 패턴 분석)

  • Kim, Tae-Hoon;Choi, Hyun-Woo;Kim, Moon-Koo;Shim, Won-Joon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.4
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    • pp.90-103
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    • 2012
  • Mallipo is a representative beach contaminated by Hebei Spirit oil spill accident in December 2007. This study aims to compare the differences of two seasons (winter and summer) for the spatio-temporal variation patterns of oiling status in the whole area and divided five regions of Mallipo beach. In the whole area, the decreasing rate of average TPH (total petroleum hydrocarbon) in winter was twice greater than summer during four years. According to the spatial variation pattern analysis of oiling status using weighted mean center and weighted standard distance, the oil concentration was clustered on southwestern region in winter, however, the TPH was dispersed in the whole area in summer. Temporal variation pattern of TPH in each of Mallipo's five regions showed that TPH had been consistently decreased in winter, but oil concentration had not been changed in summer since 2009 except the southwestern region. Therefore, in order to evaluate and predict the progress of oiling status, it is needed to analyze the spatio-temporal variation pattern of TPH using spatial analysis after separating data into seasons (e.g., winter and summer). In addition, time series analysis is useful in the regional scales through spatial partitioning rather than the whole beach area for the understanding of temporal variation pattern.

Genetic Characterization of Indigenous Goats of Sub-saharan Africa Using Microsatellite DNA Markers

  • Chenyambuga, S.W.;Hanotte, O.;Hirbo, J.;Watts, P.C.;Kemp, S.J.;Kifaro, G.C.;Gwakisa, P.S.;Petersen, P.H.;Rege, J.E.O.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.4
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    • pp.445-452
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    • 2004
  • Genetic diversity of sub-Saharan African goats was assessed using 19 microsatellite markers. Breeds were sampled from eastern Africa (Maasai, Kigezi, Mubende, North West Highland, Arsi-Bale), southern Africa (Ndebele, Pafuri) and West Africa (West African Dwarf, Maure, Djallonke). European breeds (Grisons Striped, Toggenburg), Asian breeds (Mongolian Cashmere, Bandipur) and a Middle East breed (Arab) were also included. The mean number of alleles per locus and average gene diversity ranged from 5.26$\pm$0.464 (Djallonke) to 7.05$\pm$0.516 (Mubende) and from 0.542$\pm$0.036 (Pafuri) to 0.672$\pm$0.031 (Ndebele), respectively. The between breeds variation evaluated using $$G_{ST}$$ and $\theta$ were found to account for 14.6% ($\theta$) and 15.7% ($$G_{ST}$$) of the total genetic variation. The $D_{A}$ measure of genetic distance between pairs of breeds indicated that the largest genetic distance was between Pafuri and Djallonke while the lowest genetic distance was between Arsi-Bale and North West Highland. A neighbour-joining tree of breed relationships revealed that the breeds were grouped according to their geographic origins. Principal component analysis supported the grouping of the breeds according to their geographic origins. It was concluded that the relationships of sub-Saharan African goat breeds were according to their geographical locations implying that the goats of eastern Africa, West Africa and southern Africa are genetically distinct. Within each sub-region, goat populations could be differentiated according to morphological characteristics.