• Title/Summary/Keyword: Spatial structure-based approach

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A Study on the Morphogenesis of Polyhedra as Design Sources of Architectural Structures (건축구조 디자인 요소로서 다면체의 형태구성에 관한 연구)

  • Choi, Sun-Young;Park, Sun-Woo;Park, Chan-Soo;Choi, Chui-Kyung
    • Journal of Korean Association for Spatial Structures
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    • v.6 no.2 s.20
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    • pp.107-114
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    • 2006
  • The purpose of this study is to explore the morphology of polyhedra as a tool diversifying the approach to structures and shapes, and to consider the way of the morphogenesis as structural design sources. First, through many examples in nature and styles used as the rhetorical representation of buildings, the shapes of which are based on one of polyhedra are shown. Secondly, the morphogenetic characteristics of polyhedra limited to pure lattice structure are investigated. Thereby the methodology of spatial morphogenesis of polyhedra as structural design sources are generated.

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A Simple Spatial Scheme for Adaptive Antennas in CDMA Systems

  • Su, Pham-Van;Tuan, Le-Minh;Giwan Yoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.320-322
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    • 2002
  • A new simple spatial scheme for base station with adaptive antenna in Code Division Multiplexing Access (CDMA) systems is presented. In the proposed scheme, by applying the new spatial structure lot the receiver, the system can debate the problem of which the number of users exceeds the number of adaptive antenna elements existing in the conventional spatial scheme. An adaptive algorithm based on the Mean Square Error (MSE) criterion is also derived to update the weight matrix of the proposed scheme. The results of the system capacity enhancement can be achieved by using the proposed approach. Numerical simulations are included fer illustration and verification.

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MIMO Channel Analysis Method using Ray-Tracing Propagation Model (전파예측모델을 이용한 MIMO 채널 분석 방법)

  • 오상훈;명로훈
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.8
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    • pp.759-764
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    • 2004
  • This paper proposes a method that estimates MIMO channel characteristics analytically using a 3D ray tracing propagation model. We calculate the discrete spatial correlation between sub-channels by considering phase differences of paths, and using this, estimate the mean capacity upper bound of MIMO channel by Jensen's inequality. This analysis model is a deterministic model that do not approach stochastically through measurement nor approach statistically through Monte-Carlo simulations, so this model has high efficiency for time and cost. And based on the electromagnetic theory, this model may analyze quantitatively the parameters which can affect the channel capacity - antenna pattern, polarization mutual coupling, antenna structure and etc. This model may be used for the development of an optimal antenna structure for MIMO systems.

Response of a frame structure on a canyon site to spatially varying ground motions

  • Bi, Kaiming;Hao, Hong;Ren, Weixin
    • Structural Engineering and Mechanics
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    • v.36 no.1
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    • pp.111-127
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    • 2010
  • This paper studies the effects of spatially varying ground motions on the responses of a bridge frame located on a canyon site. Compared to the spatial ground motions on a uniform flat site, which is the usual assumptions in the analysis of spatial ground motion variation effects on structures, the spatial ground motions at different locations on surface of a canyon site have different intensities owing to local site amplifications, besides the loss of coherency and phase difference. In the proposed approach, the spatial ground motions are modelled in two steps. Firstly, the base rock motions are assumed to have the same intensity and are modelled with a filtered Tajimi-Kanai power spectral density function and an empirical spatial ground motion coherency loss function. Then, power spectral density function of ground motion on surface of the canyon site is derived by considering the site amplification effect based on the one dimensional seismic wave propagation theory. Dynamic, quasi-static and total responses of the model structure to various cases of spatially varying ground motions are estimated. For comparison, responses to uniform ground motion, to spatial ground motions without considering local site effects, to spatial ground motions without considering coherency loss or phase shift are also calculated. Discussions on the ground motion spatial variation and local soil site amplification effects on structural responses are made. In particular, the effects of neglecting the site amplifications in the analysis as adopted in most studies of spatial ground motion effect on structural responses are highlighted.

New horizon of geographical method (인문지리학 방법론의 새로운 지평)

  • ;Choi, Byung-Doo
    • Journal of the Korean Geographical Society
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    • v.38
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    • pp.15-36
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    • 1988
  • In this paper, I consider the development of methods in contemporary human geography in terms of a dialectical relation of action and structure, and try to draw a new horizon of method toward which geographical research and spatial theory would develop. The positivist geography which was dominent during 1960s has been faced both with serious internal reflections and strong external criticisms in the 1970s. The internal reflections that pointed out its ignorance of spatial behavior of decision-makers and its simplication of complex spatial relations have developed behavioural geography and systems-theoretical approach. Yet this kinds of alternatives have still standed on the positivist, geography, even though they have seemed to be more real and complicate than the previous one, The external criticisms that have argued against the positivist method as phenomenalism and instrumentalism suggest some alternatives: humanistic geography which emphasizes intention and action of human subject and meaning-understanding, and structuralist geography which stresses on social structure as a totality which would produce spatial phenomena, and a theoretical formulation. Human geography today can be characterized by a strain and conflict between these methods, and hence rezuires a synthetic integration between them. Philosophy and social theory in general are in the same in which theories of action and structural analysis have been complementary or conflict with each other. Human geography has fallen into a further problematic with the introduction of a method based on so-called political ecnomy. This method has been suggested not merely as analternative to the positivist geography, but also as a theoretical foundation for critical analysis of space. The political economy of space with has analyzed the capitalist space and tried to theorize its transformation may be seen either as following humanistic(or Hegelian) Marxism, such as represented in Lefebvre's work, or as following structuralist Marxism, such as developed in Castelles's or Harvey's work. The spatial theory following humanistic Marxism has argued for a dialectic relation between 'the spatial' and 'the social', and given more attention to practicing human agents than to explaining social structures. on the contray, that based on structuralist Marxism has argued for social structures producing spatial phenomena, and focused on theorising the totality of structures, Even though these two perspectives tend more recently to be convergent in a way that structuralist-Marxist. geographers relate the domain of economic and political structures with that of action in their studies of urban culture and experience under capitalism, the political ecnomy of space needs an integrated method with which one can overcome difficulties of orthhodox Marxism. Some novel works in philosophy and social theory have been developed since the end of 1970s which have oriented towards an integrated method relating a series of concepts of action and structure, and reconstructing historical materialism. They include Giddens's theory of structuration, foucault's geneological analysis of power-knowledge, and Habermas's theory of communicative action. Ther are, of course, some fundamental differences between these works. Giddens develops a theory which relates explicitly the domain of action and that of structure in terms of what he calls the 'duality of structure', and wants to bring time-space relations into the core of social theory. Foucault writes a history in which strategically intentional but nonsubjective power relations have emerged and operated by virtue of multiple forms of constrainst wihthin specific spaces, while refusing to elaborate any theory which would underlie a political rationalization. Habermas analyzes how the Western rationalization of ecnomic and political systems has colonized the lifeworld in which we communicate each other, and wants to formulate a new normative foundation for critical theory of society which highlights communicatie reason (without any consideration of spatial concepts). On the basis of the above consideration, this paper draws a new norizon of method in human geography and spatial theory, some essential ideas of which can be summarized as follows: (1) the concept of space especially in terms of its relation to sociery. Space is not an ontological entity whch is independent of society and has its own laws of constitution and transformation, but it can be produced and reproduced only by virtue of its relation to society. Yet space is not merlely a material product of society, but also a place and medium in and through which socety can be maintained or transformed.(2) the constitution of space in terms of the relation between action and structure. Spatial actors who are always knowledgeable under conditions of socio-spatial structure produce and reproduce their context of action, that is, structure; and spatial structures as results of human action enable as well as constrain it. Spatial actions can be distinguished between instrumental-strategicaction oriented to success and communicative action oriented to understanding, which (re)produce respectively two different spheres of spatial structure in different ways: the material structure of economic and political systems-space in an unknowledged and unitended way, and the symbolic structure of social and cultural life-space in an acknowledged and intended way. (3) the capitalist space in terms of its rationalization. The ideal development of space would balance the rationalizations of system space and life-space in a way that system space providers material conditions for the maintainance of the life-space, and the life-space for its further development. But the development of capitalist space in reality is paradoxical and hence crisis-ridden. The economic and poltical system-space, propelled with the steering media like money, and power, has outstriped the significance of communicative action, and colonized the life-space. That is, we no longer live in a space mediated communicative action, but one created for and by money and power. But no matter how seriously our everyday life-space has been monetalrized and bureaucratised, here lies nevertheless the practical potential which would rehabilitate the meaning of space, the meaning of our life on the Earth.

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Analysis on Spatial Sampling and Implementation for Primal Trees (Primal Tree의 공간 분할 샘플링 분석 및 구현)

  • Park, Taejung
    • Journal of Digital Contents Society
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    • v.15 no.3
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    • pp.347-355
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    • 2014
  • The general octree structure is common for various applications including computer graphics, geometry information analysis and query. Unfortunately, the general octree approach causes duplicated sample data and discrepancy between sampling and representation positions when applied to sample continuous spatial information, for example, signed distance fields. To address these issues, some researchers introduced the dual octree. In this paper, the weakness of the dual octree approach will be illustrated by focusing on the fact that the dual octree cannot access some specific continuous zones asymptotically. This paper shows that the primal tree presented by Lefebvre and Hoppe can solve all the problems above. Also, this paper presents a three-dimensional primal tree traversal algorithm based the Morton codes which will help to parallelize the primal tree method.

Efficient Derivation of Closed-Form Green`s Functions for a Microstrip Structure

  • Oh, Byoung-Hee;Kim, Eui-Joong;Lee, Young-Soon;Young-Ki
    • Journal of electromagnetic engineering and science
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    • v.1 no.1
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    • pp.63-66
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    • 2001
  • In order to derive simple and accurate closed-form spatial Greep’s functions for the thick microstrip substrate, an efficient method based on the two-level approach, which circumvents the burdensome steps (i.e., without necessity of extraction of quasi-static contributions and subsequent determination of approximation parameters) in the previous complex image method, is considered in conjunction with the use of the original Prony`s method. The present method is observed to give more accurate results for the evaluation of the Green`s functions over wider frequency range independently of the source-to-field distances than the previous method.

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Integrating IndoorGML and Indoor POI Data for Navigation Applications in Indoor Space

  • Claridades, Alexis Richard;Park, Inhye;Lee, Jiyeong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.5
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    • pp.359-366
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    • 2019
  • Indoor spatial data has great importance as the demand for representing the complex urban environment in the context of providing LBS (Location-based Services) is increasing. IndoorGML (Indoor Geographic Markup Language) has been established as the data standard for spatial data in providing indoor navigation, but its definitions and relationships must be expanded to increase its applications and to successfully delivering information to users. In this study, we propose an approach to integrate IndoorGML with Indoor POI (Points of Interest) data by extending the IndoorGML notion of space and topological relationships. We consider two cases of representing Indoor POI, by 3D geometry and by point primitive representation. Using the concepts of the NRS (node-relation structure) and multi-layered space representation of IndoorGML, we define layers to separate features that represent the spaces and the Indoor POI into separate, but related layers. The proposed methodology was implemented with real datasets to evaluate its effectiveness for performing indoor spatial analysis.

Numerical Study on Flame Structure and Pollutant Formation for Syngas Turbulent Nonpremixed Swirling Flames (석탄가스 난류 선회 비예혼합 연소기의 화염구조 및 공해물질 생성의 해석)

  • Lee, Jeongwon;Kim, Yongmo
    • 한국연소학회:학술대회논문집
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    • 2012.04a
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    • pp.289-291
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    • 2012
  • The present study numerically investigate detailed flame structure of the Syngas diffusion flames. In order to realistically represent the turbulence-chemistry interaction and the spatial inhomogeneity of scalar dissipation rate, the Eulerian Particle Flamelet Model(EPFM) with multiple flamelets has been applied to simulate the combustion processes and NOx formation in the syngas turbulent nonpremixed flames. And level-set approach is also utilized to account for the partially premixing effect at fuel and oxidizer injector in KEPRI nonpremixed combustor. Based on numerical results, the detailed discussion has been made for the precise structure and NOx formation characteristics of the turbulent syngas nonpremixed flames.

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Securing Placeness at Rural Tourism Village Via Storytelling Implementation -Focusing on Case study of Gaesil Village- (스토리텔링구현을 통한 농촌관광마을에서의 장소성확보 -개실마을의 사례를 중심으로-)

  • Lee, Byoung-Hoon
    • Journal of Korean Society of Rural Planning
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    • v.18 no.1
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    • pp.47-57
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    • 2012
  • The following study has examined possible methodological approach and prospect of implementing storytelling in rural tourism field. It is aimed towards deducing principles of space composition behind securing placeness of rural tourism village through storytelling. The research had been conducted by archival research and case study on field of interest, and its findings are as follows: 1) Storytelling exhibits principles of narrative structure (exposition, complication, climax, and resolution) in various fields, and has shown tendency to structuralize a plot. 2) It can be said that storytelling is deeply related with people's associations of their inner mind. This can be a logical explanation of a certain sight or location, which is a physical environment itself being the actual narrator and distributor in storytelling. 3) In order to convey a story in a more convincing way, storytelling a naming strategy based on a rhetorical technique, which has been shown to positively influence creating unique placeness of a rural village. As indicated in our study, means of storytelling-"Continuity and tourist circulation of space composition with a narrative structure, spatial hierarchical order, concealment and revelation, cast, and naming based on rhetorical technique and facilities positioning"-is a viable solution that can bring recovery of the rural village's unique placeness, as well as spatial development for sustainable rural tourism.