• Journal of Ecology and Environment
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• v.41 no.8
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• pp.223-234
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• 2017

Background: Spatial structure of plants in a population reflects complex interactions of ecological and evolutionary processes. For dioecious plants, differences in reproduction cost between sexes and sizes might affect their spatial distribution. Abiotic heterogeneity may also affect adaptation activities, and result in a unique spatial structure of the population. Thus, we examined sex- and size-related spatial distributions of old-growth forest of dioecious tree Torreya nucifera in extremely heterogeneous Gotjawal terrain of Jeju Island, South Korea. Methods: We generated a database of location, sex, and size (DBH) of T. nucifera trees for each quadrat ($160{\times}300m$) in each of the three sites previously defined (quadrat A, B, C in Site I, II, and III, respectively). T. nucifera trees were categorized into eight groups based on sex (males vs. females), size (small vs. large trees), and sex by size (small vs. large males, and small vs. large females) for spatial point pattern analysis. Univariate and bivariate spatial analyses were conducted. Results: Univariate spatial analysis showed that spatial patterns of T. nucifera trees differed among the three quadrats. In quadrat A, individual trees showed random distribution at all scales regardless of sex and size groups. When assessing univariate patterns for sex by size groups in quadrat B, small males and small females were distributed randomly at all scales whereas large males and large females were clumped. All groups in quadrat C were clustered at short distances but the pattern changed as distance was increased. Bivariate spatial analyses testing the association between sex and size groups showed that spatial segregation occurred only in quadrat C. Males and females were spatially independent at all scales. However, after controlling for size, males and females were spatially separated. Conclusions: Diverse spatial patterns of T. nucifera trees across the three sites within the Torreya Forest imply that adaptive explanations are not sufficient for understanding spatial structure in this old-growth forest. If so, the role of Gotjawal terrain in terms of creating extremely diverse microhabitats and subsequently stochastic processes of survival and mortality of trees, both of which ultimately determine spatial patterns, needs to be further examined.

• Journal of Distribution Science
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• v.17 no.3
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• pp.21-30
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• 2019

Purpose - While many related prior studies have focused on the segregation by race and ethnicity, the academic interest in the separation of residence by income and social class is gradually increasing. This study aims to not only investigate spatial pattern of economic segregation and poverty rate in South Korea, but also shed light on what affect residential distribution of the poor. Research design, data, and methodology - The unit of analysis is Si-Gun-Gu municipal level entities of South Korea. Most demographic, socioeconomic, and residential variables were derived from Korean Census Data in 2015. In order to examine spatial patterns of economic segregation and poverty rate in South Korea, a series of measurements and visualization was conducted through the Geo-Segregation Analyzer and ArcGIS programs. Determinants of economic segregation and local poverty rates were investigated by regression analyses using STATA. Results - The spatial patterns of areas with high poverty rates were extremely clustered, while the distribution of areas with high economic segregation was relatively evenly distributed. Demographic, residential, and local factors appeared to affect whether the poor live in particular area or spread evenly. Conclusions - The factors that raise the poverty rate result in lower level of economic segregation, while factors that reduce the poverty rate lead to severe level of economic segregation.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.1
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• pp.45-56
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• 2003

In this study the distribution patterns of the metallic components were analyzed both before and after the Asian Dust (AD) events at 2001 by comparing the chemical composition of metallic components in terms of various statistical methods. According to the AD/NAD concentration ratio of metallic components, the main components of crustal soils were exhibiting the values above 1.0; but opposite results were seen dominantly for hazardous metallic components. Examination of fine-to-coarse (F/C) ratios of metallic components showed higher values for major anthropogenic components including Pb (5.83). Ni (2.61), etc. Comparison of our measurement data with those obtained within and across the Korean peninsula indicated that the metallic distribution patterns of the study area can be distinguished from previous studies. The results of our analysis, when investigated in relation with air mass movement patterns. indicated evidence of the direct influence of AD events and anthropogenic processes.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.272-275
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• 1997

Noninvasive multifrequency microwave radiometry using coaxial waveguide antenna has been investigated for a homogeneous and our layer human body model. We derived finite-difference time-domain(FDTD) algorithm and equation of MUR and generalized perfectly matched layer(GPML) absorbing boundary conditions(ABCs) in cylindrical coordination. The coupling between coaxial waveguide antenna and a biological object was analyzed by use of the FDTD method using MUR and GPML ABCs to obtain the absorbed power patterns in the media. The specific absorption rates(SAR) distribution which was corresponding to the temperature distribution was calculated in each region by use of the steady-state response in FDTD method. The SAR patterns of FDTD method using MUR ABCs was compared with those of FDTD method using GPML ABCs.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.1
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• pp.225-232
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• 2005

The paper presented results of the strength distributions and tension failure behaviors of splices subjected to tension forces. The bolting patterns in the tension splices are regular and staggered patterns in the research. The finite element analyses were carried out to examine the experimental results and evaluated the stress distribution patterns. The yield stresses, maximum tension stresses, stress distribution ratios, and effective net areas were analyzed through the tension experiments.

• Journal of the Ergonomics Society of Korea
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• v.12 no.1
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• pp.3-15
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• 1993

The pressure distribution between human body and seat surface has been considered as an important factor affecting seating comfort. However, it is rare to find general guidelines of how to analyze these pressure patterms related to the seating comfort. In order to investigate the relationship between the pressure patterns and the subjective feeling of seating comfort, a high-resolution body pressure measurement system was adopted. The measured patterns showed that the clear distinctions between the comfortable seats. It was also possible to estimate the seating comfort based upon the analysis of the pressure patterns. The further research will be focused on finding out the relationship between physical seat design parameters and the seating discomfort.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.1
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• pp.41-46
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• 2022

Psalidoremus is one of the subgenus which consists of five species and eleven subspecies through Taiwan, Japan, Korea and north eastern part of China which present strong endemism to their distribution. While most of advance studies focus on the new species or subspecies from this taxon, this paper suggests paleogeographical assumption and hypothesis of how they diverged from common ancestors. Phylogeographical patterns illustrated by the distribution of five species, which including Prosopocoilus inclinatus, Prosopocoilus hachijoensis, Prosopocoilus dissimilis, Prospocoilus pseudodissimilis, Prosopocoilus motschulskii respectively, has been assessed in this research. Speciation history is suggested by morphological tendencies especially in male mandibles with assumption from geographical patterns of under sea level.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.427-430
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• 1991

In this study, in order to observe treeing of prebreakdown phenomena, time variation of acoustic emission properties due to initiation and propagation of tree in LDPE was investigated under AC voltage. The experimental results were as following, pulse number and average amplitude of AE were increased along with near breakdown rather than tree initiation, also, according to increasing of applied voltage, tree propagation was blunted, while pulse number and average amplitude of AE was promoted. In each applied voltage, ${\phi}-a$ distributions during propagation of tree were changed to special patterns, skewness S and kurtosis K reflected well time variation of ${\phi}-a$ distribution patterns. It is thought that initiation and propagation state of tree can be easily monitored, so long as time variation of pulse number and average amplitude of AE, skewness Sand kurtosis K of ${\phi}-a$ distribution are always monitored.

• Journal of Environmental Impact Assessment
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• v.15 no.3
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• pp.179-191
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• 2006

The authors argue that the current Government Information System for asthmatics appears to be non-user friendly due to lack of the cartographic representation for the text based statistical data. Acknowledging these constraints, an operational, user-friendly map for asthmatic prevalence has been generated by combining existing statistical data with the administrative Dong boundary map under GIS environment. The Geographical User Interface, in particular, were ideally suited to deriving the major distribution patterns that more asthmatic prevalence tends to be occurred on conventional commercial district and industrial complex. A visual map using spatial modelling technology were generated to show the fact that some degree of increasing or decreasing trends of asthmatic prevalence already exists in the experimental sites. It could be used as an evidence to restrict initiation of development activities causing negative influence to asthma such as road construction. The result of this study would play a crucial role in improving the quality of environmental health information service if it is operationally introduced into the Government since the highly user-friendly interface provides a completely new means for disseminating information for asthmatics in a visual and interactive manner to the general public.

• ALGAE
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• v.27 no.2
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• pp.115-123
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• 2012

The establishment of algal spores plays an essential role in adult kelp distribution and abundance patterns. Sedimentation is a key variable regulating algal spore settlement and success, possibly controlling species-specific dominance $in$ $situ$. Laboratory experiments were used to determine spore attachment and survival rates of two Alaskan canopy-forming kelps, $Nereocystis$ $luetkeana$ (K. Mertens) Postels & Ruprecht and $Eualaria$ $fistulosa$ (Postels & Ruprecht) M. J. Wynne, to various types of sediment loading. Spore attachment for both species was significantly and similarly affected by three sediment treatments: suspended particles; settled sediment covering the substratum; and smothering of attached spores by settling sediment. Spore attachment decreased by approximately 90% at 420 mg sediment $L^{-1}$, the highest sediment load tested here, under all three treatments for both species. These results suggest that increases in sedimentation may constrain the success of the spore stages, but sediment does not seem to be a likely factor explaining species-specific distribution patterns. However, while sedimentation affected spores of both species similarly, timing of spore release in relation to times of maximum sediment load in the water might differ for different species, possibly explaining kelp species distribution patterns.