• 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.

• Geomechanics and Engineering
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• v.17 no.6
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• pp.565-572
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• 2019

Spatial variability is an inherent characteristic of soil, and auto-correlation length (ACL) is a very important parameter in the reliability or probabilistic analyses of geotechnical engineering that consider the spatial variability of soils. Current methods for estimating the ACL need a large amount of laboratory or in-situ experiments, which is a great obstacle to the application of random field theory to geotechnical reliability analysis and design. To estimate the ACL reasonably and efficiently, we propose a micro-structure based numerical simulation method. The quartet structure generation set algorithm is used to generate stochastic numerical micro-structure of soils, and scanning electron microscope test of soil samples combined with digital image processing technique is adopted to obtain parameters needed in the QSGS algorithm. Then, 2-point correlation function is adopted to calculate the ACL based on the generated numerical micro-structure of soils. Results of a case study shows that the ACL can be estimated efficiently using the proposed method. Sensitivity analysis demonstrates that the ACL will become stable with the increase of mesh density and model size. A model size of $300{\times}300$ with a grid size of $1{\times}1$ is suitable for the calculation of the ACL of clayey soils.

• Journal of Korean Association for Spatial Structures
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• v.19 no.3
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• pp.93-100
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• 2019

In this study, the retractable-roof spatial structure was chosen as the analytical model and a tuned mass damper (TMD) was installed in the analytical model in order to control the seismic response. The analysis model is mainly consisted of runway trusses (RT) and transverse trusses (TT), and the displacement response was analyzed by installing TMD on those trusses. The mass of the single TMD which is installed in the analytical model was set to 1% of the total structure mass and the total TMD mass ratio was set to be 8% or 6%. In addition, the mass of a single TMD was varied depending on the number of installations. As a result of analyzing the optimal number of installations of TMD, the displacement response was reduced in all cases compared to the case without TMD. Above all, the case with 8 TMDs was the most effective in reducing he displacement response. However, in this case, as the load on the upper structure of the retractable-roof spatial structure increases, the total mass ratio of TMD was maintained and the number of TMDs was increased to reduce the mass ratio of one TMD.

• Structural Engineering and Mechanics
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• v.39 no.4
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• pp.541-558
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• 2011

This paper presents an analysis of stochastic eigenvalue problem of plane bar structures. Particular attention is paid to the effect of spatial variations of the flexural properties of the structure on the first four eigenvalues. The problem of spatial variations of the structure properties and their effect on the first four eigenvalues is analyzed in detail. The stochastic eigenvalue problem was solved independently by stochastic finite element method (stochastic FEM) and Monte Carlo techniques. It was revealed that the spatial variations of the structural parameters along the structure may substantially affect the eigenvalues with quite wide gap between the two extreme cases of zero- and full-correlation. This is particularly evident for the multi-segment structures for which technology may dictate natural bounds of zero- and full-correlation cases.

• Journal of Digital Convergence
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• v.4 no.2
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• pp.67-73
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• 2006

This paper is an analysis of the Category Individual Residence urban spatial structure along the National Route BO (Koushu-Kaido), one of the major roads in Japan, and the degree of differences between locations and its changes between the points of time. The analysis was based on the GIS technique. Whilst, previous studies were based on municipal boundaries or mesh units as sources of data, GIS allowed the use of variable geographical units, Roadside zone, Inner zone, North zone, South zone, Blocks. As an example to apply the technology of GIS, 1986's and 1991's building polygon data of the Urban Planning Bureau of Tokyo Metropolitan Government are used. The layers referred to the analyses is the building polygons with the amount of stories, building area, floor area and the material of the building. Two statistical analysis are executed; one is the test of the regional equality about the number of story of building, building area, floor area and fireproof building ratio.

• Korean Institute of Interior Design Journal
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• v.26 no.1
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• pp.83-90
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• 2017

The purpose of this study is to investigate the possibilities of architectural planning and expression of the relationship between structure and skin in contemporary architecture. For this purpose, we show interior space images -integration of structure and skin architecture- to students and experts of the related majors, and let them mark their feeling on the questionnaire composed spatial expression vocabulary extracted through the literature study on spatial sensibility, and analysis data. As a result, in contemporary architecture where the structure and the skin are integrated, form elements have a stronger influence on formation of space sense than elements of light and size, and aesthetics, characteristic, and temporality are common in the inner space, Three types of four types showed unique characteristics, and it was confirmed that there is a causal relationship between the spatial feeling factor and the spatial feeling. This means that the relationship between the structure and the skin can be considered as a planning factor, and this study is expected to be used as such basic data.

• Journal of Korean Association for Spatial Structures
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• v.7 no.2 s.24
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• pp.75-82
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• 2007

Building costs means capital costs which include cost of land, cost of acquiring and preparing the site, construction costs, engineering fees, furnishings, cost of financing the project, and cost of management required to run and maintenance the building for use. An economic analysis is one of the most important factor to determine the project feasibility. The purpose of the this study is to analysis on the construction cost structure of steel truss stadium.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.3
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• pp.50-57
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• 1999

This study aim to clarify the way of spatial composition of Tongdo Temple by diachronic analysis. The way of spatial composition was clarified through the analysis of built in architectural system in three periods. The result are as follows; 1. Spatial composition of Tongdo temple was changed in three period that it were establishment period, 1300s, and 1700s by the transition of meaning structure occurring the transition of spatial composition. 2. It was found out that the wat of spatial composition was three through the diachronic analysis the transition of spatial composition in Tongdo temple. 3. Juxtaposition as a way of spatial composition found out through the diachronic analysis is equivalent articulation of three sections; an upper, a middle, and a lower section and polyaxis or polycore in the each sections. Fusion is heterogenetic minglement mingling different kind of buildings and conjugation conjugating different kind of decorations. And accumulation of layer is mutilayer laying different time of layer and multi aspect aligning different kind of aspects since the temple's establishment.

• Steel and Composite Structures
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• v.3 no.4
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• pp.277-287
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• 2003

The low boundary of load carrying capacity of the elastic-plastic spatial grid structures depend on numerous values and their variability assumed in designing process. Analysed influence all this values in searching for optimal variant of the structure lead to too great problem even taking into consideration actual computational power we have in disposal. Therefore one can take only a few values which have greatest influence on the optimal choice. In optimal analysis of the elastic-plastic spatial grid structures the previously proposed method with subsequent modification (Karczewski 1980), (Karczewski, Barszcz and Donten 1996), (Karczewski and Donten 2001) as well as computer program which was worked out by Donten K. to make possible practical utilisation this method was employed. The paper deal with evaluation of influence dimensions of particular values for choice of optimal variant of the structure. One among this values is distribution of the struts in the structure.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.36 no.1
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• pp.93-104
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• 2020

The purpose of this research is to clarify the relationship between the location of markets and the spatial structure of historic center in Beijing of 18th century by network analysis method onto the historic map of Beijing 'Qianlong-Jincheng-Quantu(乾隆京城全圖)' produced in 1750. By categorizing the grade of each market, it is revealed that the location of markets in Beijing under Qing Dynasty was not only decided by the various factors as policy of the regime and traditional social usages but also by the spatial structure of urban space in historic part of the city. At the same time, the sociopolitical factors and the spatial structure of urban space might influence reciprocally in defining the physical state of urban space.