• Title/Summary/Keyword: Geographic variation

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Determination of Variable Rate Fertilizing Amount in Small Size Fields Using Geographic Information System

  • S. I. Cho;I. S. Kang;Park, S. H.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2000.11b
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    • pp.236-245
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    • 2000
  • The feasibility of precision farming for small sized fields was studied by determining fertilizing amount of nitrogenous and calcareous to a cite specific region. A detailed soil survey at three experimental fields of 672㎡, 300㎡ and 140㎡ revealed a considerable spatial variation of the pH and organic matter(OM) levels. Soil organic matter was measured using Walkley-Black method and soil pH was measured with a pH sensor. Soil sample was obtained by Grid Node Sampling Method. The soil sampling depth was 10 - 20 cm from the soil surface. To display soil nutrient variation, a soil map was made using Geographic Information System (GIS) software. In soil mapping, soil data between nodes was interpolated using Inverse Distance Weighting (IDW) method. The variation was about 1 - 1.8 in pH value and 1.4 -7 % in OM content. Fertilizing Amount of nitrogenous and calcareous was determined by the fertilizing equation which was proposed by National Institute of Agricultural Science and Technology.(NIAST). The variation of fertilizing amount was about 3 - 11 kg/10a in nitrogenous and 70 - 140 kg/10a in calcareous. The results showed a feasibility of precision fertilizing for small size fields.

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Morphological Variation in Polygonum setaceum (Polygonaceae) (여뀌과 식물 Polygonum setaceum의 형태적 변이)

  • 박종욱
    • Journal of Plant Biology
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    • v.34 no.3
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    • pp.177-183
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    • 1991
  • Patterns of morphological variation in Polygonum setaceum Baldwin ex Elliott are examined, and the taxonomic significance of the varieties recognized by Fernald is reevaluated. The diagnostic characters used to differentiate the varieties in P. setaceum demonstrate virtually continuous variation, and broad geographic intergradation is recognized. Principal components analyses of major morphological characters also fail to separate the varieties. These results strongly suggest that recognition of var. setaceum, var. interjectum, and var. tonsum by Fernald is unwarranted.

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Phylogenetic relationship of the wild silkworm, Bombyx mandarina, inferred from aninternal transcribed spacer (ITS) of rDNA

  • Kim, Kyung-ah;Nho, Si-kab
    • Proceedings of the Korean Society of Sericultural Science Conference
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    • 2003.04a
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    • pp.42-42
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    • 2003
  • The wild silkworm, Bombyx mandarina, was believed the only ancestor of B. mori, inhabits the limited area of Eastern Asia including China, Korea and Japan. However, the geographic dimorphism of B. mandarina was reported with chromosome number and arylphorin gene. In connection with those dimorphism, we studied the genetic differences of ITS-2 region in rDNA purposing the differentiation and geographic variation within the species of B. mandarina. (omitted)

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Geographic Variation of Lamina Circularis in Cobitis longicorpus (Pisces: Cobitidae) (왕종개 Colitis longicowus (Pisces: Cobitida티 골질반의 지리적 변이에 관하여)

  • 김종범;김재야양서영
    • The Korean Journal of Zoology
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    • v.34 no.1
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    • pp.103-109
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    • 1991
  • 한국 특산종 Cobitis longicorpus (왕종개)의 주요 분류형질인 골절반의 지리적 변이를 조사하기 위하여 남한의 12개집단 205개체를 이용, 골질반의 type분석과 계수학분석을 실시하였다. Type분석 결과, 동해유입하천집단(영덕의 송천, 축산천, 경주 형산강, 울주 회야강)의 골질반은 등근 삼각형, 삼각형, 인각형으로 남해 유입하천 및 도서집단의 타원형, 반타원형, 부채꼴과 구별되었다. 골질반의 계수화분석 결과에서도 동해유입하천의 골질반 폭은 비교적 좁아 남해유입하천 및 도서지방과의 평균 CD값이 1.64로 새종 수준 이상의 차이를 보였다. 아울러 조사, 비교된 제 1 체측반문도 동해유입하천에서는 C. longicorpus의 특징이 전혀 나타나지 않아, 원기재질단인 섬진강집단을 포함한 남해유입하천 및 도서집단과 구별된 새종수준의 종분화가 이루어진 것으로 사료되었다.

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Evaluation of Geographic Indices Describing Health Care Utilization

  • Kim, Agnus M.;Park, Jong Heon;Kang, Sungchan;Kim, Yoon
    • Journal of Preventive Medicine and Public Health
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    • v.50 no.1
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    • pp.29-37
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    • 2017
  • Objectives: The accurate measurement of geographic patterns of health care utilization is a prerequisite for the study of geographic variations in health care utilization. While several measures have been developed to measure how accurately geographic units reflect the health care utilization patterns of residents, they have been only applied to hospitalization and need further evaluation. This study aimed to evaluate geographic indices describing health care utilization. Methods: We measured the utilization rate and four health care utilization indices (localization index, outflow index, inflow index, and net patient flow) for eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee replacement surgery, caesarean sections, hysterectomy, computed tomography scans, and magnetic resonance imaging scans) according to three levels of geographic units in Korea. Data were obtained from the National Health Insurance database in Korea. We evaluated the associations among the health care utilization indices and the utilization rates. Results: In higher-level geographic units, the localization index tended to be high, while the inflow index and outflow index were lower. The indices showed different patterns depending on the procedure. A strong negative correlation between the localization index and the outflow index was observed for all procedures. Net patient flow showed a moderate positive correlation with the localization index and the inflow index. Conclusions: Health care utilization indices can be used as a proxy to describe the utilization pattern of a procedure in a geographic unit.

Mitochondrial DNA Sequence Variation of the Mason Bee, Osmia cornifrons (Hymenoptera: Apidae)

  • Kim, Hwa-Young;Lee, Kyeong-Yong;Lee, Sang-Beom;Kim, Se-Ryeon;Hong, Mee-Yeon;Kim, Dong-Young;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.16 no.2
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    • pp.75-86
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    • 2008
  • In order to understand geographic genetic variation and relationship among populations of the mason bee (Osmia cornifrons Radoszkowsky), which is used as pollinator for apple tree, we sequenced a portion of mitochondrial (mt) COI gene, which corresponds to "DNA Barcode" region (658 bp) from 81 O. cornifrons individuals collected over eight localities in Korea. The sequence data revealed overall moderate to low genetic diversity within species, with a maximum sequence divergence of 0.76%. Geographically, two haplotypes (BAROC01 and BAROC02) were widespread with a frequency of 82.7%, whereas several haplotypes were found in a locality as a single individual, suggesting that haplotype distribution can be summarized as coexistence of a few widespread haplotypes and several regionally restricted haplotypes. Overall, high rate of per generation female migration (Nm=$1.1{\sim}$infinite) and low level of geographic subdivision ($F_{ST}=0{\sim}0.315$) among localities were characteristic. Although two populations (p < 0.026) were genetically subdivided from the remaining localities, no clear polarity was observed. Taken together, the nature of genetic divergence of the mason bee populations is characterized as one that possessing moderate to low genetic diversity, high gene flow, and wide spread haplotypes with ahigh frequency, concordant with the capability of dispersal in connection with the lack of historical biogeographic barriers.

Geographic Variation and Genetic Diversity between Polluted and Unpolluted Sites of Korean Littorina brevicula(Gastropoda, Littorinidae) Based on the Mitochondrial Cytochrome b Gene Sequence (미토콘드리아 Cytochrome b 유전자의 염기서열 분석을 이용한 한국산 총알고둥(복족강, 총앙고둥과)의 지리적 변이 및 오염.비오염지역간의 유전적 다양성)

  • Suh, Jae-Hwa;Kim, Sook-Jung;Song, Jun-Im
    • Animal Systematics, Evolution and Diversity
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    • v.18 no.1
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    • pp.75-84
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    • 2002
  • MtDNA cyt b gene was used to investigate the geographic variation of 11 populations (106 individuals) of the planktonic developing, periwinkle Littorina brevicula, throughout Eastern, Western, and Southern coastal regions in Korea. The sequence of 500 base pairs and 13 different haplotypes were determined. Haplotype LbA was predominated through the populations studied with frequence of 0.877. Haplotypes were shown different frequencies in each coastal region (0.82, 0.90, and 1.00, respectively). enetic analysis of the 61 individuals of L. brevicula from the polluted and unpolluted sites yielded 8 distinct haplotypes. Haplotype LbA also was most common, and it was shared by 0.872 of frequency among specimens.

Geographic Variation and Distribution of Nuptial Color Patterns in Korean Chub, Zacco koreanus (Cyprinidae, Pisces) (참갈겨니, Zacco koreanus (잉어과, 어강)의 혼인색의 지리적 변이와 분포)

  • Chae, Byung Soo;Yoon, Hee Nam
    • Korean Journal of Ichthyology
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    • v.18 no.2
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    • pp.97-106
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    • 2006
  • In the investigation of geographic variations on the Zacco koreanus distributed widely in southern Korean Peninsula, it was found that there were distinct differences in the nuptial coloration among geographic populations. These color variations were presence of red band on anterior margin of pectoral fin and color patterns of dorsal fin. On the basis of those color variations three color types were recognized in Z. koreanus, that is, HK, NS and NE types. HK types were distributed mainly in Han and Geum River, NS types in Nakdong and Seomjin River, and NE types in Nakdong River and small streams on the east coast. It was noted ecologically and taxonomically that these three types were well separated geographically and two types of them, i.e., NS and NE types cohabit in the Nakdong River and shown a tendency of microhabitat segregation between them.

Small Area Variation (소규모 지역간 의료이용의 차이에 관한 문헌고찰)

  • 조우현;김한중
    • Health Policy and Management
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    • v.1 no.1
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    • pp.42-53
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    • 1991
  • Analysis of health care utilization is very important for health care policy development. Traditional studies of health care utilization were focused on measuring the level of health care utilization and on analyzing the determinants of health care utilization in the defined areas and populations. But there were some limitations in comparing the health care utilizations rates in traditional studies because so many factors were to be considered. Small area analysis is a method used to demonstrate substantial variations in health care utilization with popualtion-base use rates among similar geographic areas. This review discusses the methods, magnitude and trend of geographic variations, factors influencing small area variations, and makes suggestions for further study. Finally, the article discusses the necessity and feasibility of small area analysis in Korea.

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