• Journal of Korean Society of Forest Science
• /
• v.100 no.2
• /
• pp.226-231
• /
• 2011

Ulmus davidiana var. japonica is a deciduous tree species used for traditional medicine. This study was conducted to investigate the variation of samara, seed, germination and growth characteristics among populations and among individuals within five natural populations of U. davidiana var. japonica distributed in Korea. The ten characteristics of samara and seed, the three germination behaviors as well as the two growth traits were studied in samaras collected from total 32 trees. Statistical analysis of all characteristics showed that there were significant differences among populations as well as among individuals within populations. In this study, the mean characteristics of this species were 13.0 mm in samara length, 9.7 mm in samara width, 1.37 in samara index, 0.015 g in samara weight, 3.07 mm in samara stalk length, 3.85 seed length, 2.66 mm in seed width, 1.46 in seed index, 1.29 mm seed thickness, 0.0062 g in seed weigh, 34.8% in germination percentage, 8.6 days in mean germination time, 3.5 ea./day in gemination rate, 37.7 cm in height and 4.90 mm in root collar diameter. Especially, coefficients of variations in samara weight, germination percentage, germination rate, height and root collar diameter were relatively high (${\geq}30.0%$) compared to other traits. There was no significant relationship between population association and geographical distribution. The results of principal component analysis for 15 characteristics showed that primary four principal components (PC's) explained 100% of the total variation. The first PC accounted for 41.8% of the variability which correlated with morphological traits, the second PC accounted for 32.9% of the variability which correlated with germination behaviors and the third PC accounted for 16.3% of the variability which correlated with growth traits.

• Korean Journal of Environmental Biology
• /
• v.22 no.2
• /
• pp.295-299
• /
• 2004

The lacertid lizard Takydromus wolteri widely distributed in South Korea, but intraspecific diversity of this species was not almost studied. T. wolteri represented by 8 specimens collected from 5 localities were analyzed by the Randomly Amplified Polymorphic DNA (RAPD) method with 28 random decamer primers and the phenogram constructed by using the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) method based on RAPD data. The populations of T. wolteri using in this paper were collected from Gyeonggi-do, Chungcheongbuk-do, Jeju-do, Jeollanam-do and Gyeongsangnam -do in South Korea. Among 68 different bands detected in RAPD analysis, 59 bands (87％) showed polymorphism. The phenogram showed that the populations of T. wolteri were grouped into two. These results suggest that T. wolteri were supported intraspecific diversity.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.23 no.6
• /
• pp.425-438
• /
• 1990

Acoustic and ichthyoplankton data collected from Shelikof Strait in 1981, 1984 and 1985 were examined to determine spawning ground and period of walleye pollock, Theragra chalcogramma. Walleye pollock in the Gulf of Alaska migrated into Shelikof Strait for spawning during late winter and early spring. They entered Shelikof Strait via the warm and saline deep layer (continental slope water mass) in the southwestern channel, and major fish schools concentrated for spawning along the deep trough (250~300m) in the western part of the central strait. Peak spawning activity occurred there from late March to early April. Peak spawning time and area in Shelikof Strait varied little between years, despite difference in hydrography. Geographical advantages together with some oceanographic phenomena (reduced water transport and reduced mixed layer depth in spring) made that area an optimal spawning ground in the Gulf of Alaska during early April. After early April, spawning intensity decreased rapidly and the spawning area tended to expand to the northeast and southwest.

• Journal of the Economic Geographical Society of Korea
• /
• v.18 no.1
• /
• pp.1-16
• /
• 2015

It is widely believed that increasing socio-economic polarization inspired by globalization and economic restructuring worsens residential segregation by class in Korean cities. However, the existing literature falls short in showing the recent changes of the residential segregation, particularly after the 1997 financial crisis, with reliable and systematic segregation measures. Noting that there are the two major dimension in residential segregation - evenness-concentration and exposure-clustering - this study introduced not only global measure (dissimilarity index and isolation/interaction index) but also local measures (location quotient and Local Moran's I) for each dimension. These measures are applied to the case study of Seoul in the 2000s. The class is defined by education attainment and the data is obtain through the MicroData System Service System(MDSS). The result shows that the residential segregation by education attainment persists through 2000s and even get worse in some dimension. More significantly, it turns out that high-class and low-class residence are nearly mirror-images of each other, indicating high segregation.

• Journal of the Korean Geographical Society
• /
• v.49 no.1
• /
• pp.57-76
• /
• 2014

Conventional treatments of war diffusion focus extensively on dyadic relationships, whose impact is thought to be immutable over the course of the conf lict. This study indicates that such conceptions are at best incomplete, and more likely misleading to explain the spatial diffusion of wars. Using social network analysis, we examine war joining behavior during World War I. By employing social network analysis, we attempted to overcome the dichotomous understanding of geography as space and network in the discipline of conflict studies. Empirically, networked structural elements of state relationships (e.g., rivalry, alliances) have explanatory and predictive value that must be included alongside dyadic considerations in analyzing war joining behavior. In addition, our analysis demonstrates that the diffusion of conflict involves different driving forces over time.

• Animal Systematics, Evolution and Diversity
• /
• v.11 no.3
• /
• pp.359-377
• /
• 1995

Morphological and isozyme analyses were used to examine closely related species of Tridentiger obscurus and \ulcorner: brevispinis, a pair of cryptic species which has intricate problem with regard to species boundary, and to clarify the taxonomic position. In this study, it was revealed from their 17 allopatric streams that there are differences of band ornamentation on the lateral side and three genetic markers between two species. However, genetic relationship between them (S = 0.813, D = 0.192) was within the intraspecific level of similarity. However, at the sympatry of two species no hybrid was found except at Bangjuk stream where the electrophoretic hybrids with slight deficiency of heterozygosity were observed. It is shown that at sympatry there is a finer microenvironmental subdivision between two species at all populations including Bangjuk stream. To manifest the extent of assortative mating, four syrnpatric subpopulations at Bangjuk stream were analyzed for departure from Hardy-Weinberg equillibrium by F-statistics. All subpopulations were deviated significantly from the expectation under random mating. The evidences presented here supports the recognition of Tridentiger obscurus and T. brevispinis as semispecies in the late stage of reproductive isolation

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.12A
• /
• pp.1171-1180
• /
• 2010

In wireless sensor networks, reliable event detection is one of the most important research issues. For the reliable event detection, previous works usually assume the events are only individual objects such as tanks and soldiers. Recently, many researches focus on detection of continuous objects such as wild fire and bio-chemical material, but they merely aim at methods to reduce communication costs. Hence, we propose a reliable continuous object detection scheme. However, it might not be trivial. Unlike individual objects that could be referred as a point, a continuous object is shown in a dynamic two-dimensional diagram since it may cover a wide area and it could dynamically alter its own shape according to physical environments, e.g. geographical conditions, wind, and so on. Hence, the continuous object detection reliability can not be estimated by the indicator for individual objects. This paper newly defines the reliability indicator for continuous object detection and proposes an error recovery mechanism relying on the estimation result from the new indicator.

• Journal of the Korean Geographical Society
• /
• v.47 no.6
• /
• pp.899-920
• /
• 2012

The purpose of this study is to examine and better understand student's perception of territory in the deterritorialized world. Students' sketch maps were analyzed to investigate the way of which they recognized the form of national territory, border, geographic location, and neighboring countries. In addition, students' values, attitudes, and affection for their homeland and other countries were observed through the awareness of North Korea, DMZ, and Dok-do island. Scrutinizing students' sketch maps and follow-up interviews provided much more in-depth context for understanding students' narratives about territorial identity than did the analysis of structured surveys since they can freely draw and sketch their cognition. A qualitative data analysis builded a code list with 67 codes generated from 626 quotations. These data were exported to CSV format to elicit and evaluate differential variances of territorial identity along with student's Social Studies score and Grade Point Average for inferential statistics and quantitative data analysis using SPSS. Based on the results of data analysis and discussion, some suggestions to build a model of territorial education and to develop teaching and learning materials in the domain of geography education were provided.

• Journal of Life Science
• /
• v.14 no.2
• /
• pp.345-350
• /
• 2004

The present study was investigated microgeographic variations to spatial autocorrelation in the Korean alder, Alnus hirsuta. Separate counts of each type of join (combination of genotypes at a single locus) for each allele, and for each distance class of separation, were tested for significant deviation from random expectations by calculating the Standard Normal Deviation (SND). Moran's I was significantly different from the expected value in 24 of 120 cases (20.0%). 17 of these values (14.2%) were significantly negative, indicating genetic dissimilarity among pairs of individuals in the ten distance classes. Many Korean populations of alder are small and are distributed by men for firewood. This occasional cutting of seed-bearing stems may bring a high level of gene flow. In addition, stump sprouting ability also may contribute to the fact that the Chengkwang population at Gijang is unusual in lacking spatial genetic structure.

• Journal of Korean Society for Geospatial Information Science
• /
• v.20 no.3
• /
• pp.57-63
• /
• 2012

The ordinary least square (OLS) regression model is assumed that the relationship between distribution of longevity population and environmental factors to be identical. Therefore, the OLS regression analysis can't explain sufficiently the spatial characteristics of longevity phenomenon and related variables. The geographically weighted regression (GWR) model can be representing the spatial relationship of adjacent area using geographically weighted function. It also characterized which can locally explain the spatial variation of distribution of longevity population by environmental characteristics. From this point of view, this study was performed the comparative analysis between OLS and GWR model for ecological factors of longevity existing studies. In the results, GWR model has higher corresponded to model than OLS model and can be accounting for spatial variability about effect of specific environmental variables.