• Journal of the Korean housing association
• /
• v.25 no.2
• /
• pp.63-70
• /
• 2014

The dependence on cars for urban mobility and the exponential increase in traffic and urban infrastructure to sustain traffic have lead to an encapsulated way of life, where the connection with the natural environment is much more reduced and programmed. In a previous study, a process based on estimating distances showed that children who move around their city by automobile do not appreciate their environment as a spatial continuum, but rather as a series of independent spaces that are reached by automobile or bus, thereby evidencing a different way of conceptualizing urban space in the light of different cognitive structures (Goluboff, Garc$\acute{i}$a-Mira, and Garc$\acute{i}$a-Font$\acute{a}$n, 2002). The present study is concerned with the process of understanding and knowledge of urban space, and contrasting the cognitive structure of different groups. The implications that this study may have for urban planning are discussed.

• Journal of the Korean Geographical Society
• /
• v.46 no.6
• /
• pp.724-737
• /
• 2011

The goal of solving a contiguous land acquisition problem is to find an optimal cluster of land parcels so that one can move from an acquired parcel to another without leaving the cluster. In many urban and regional planning applications, criteria such as acquisition cost and compactness of acquired parcels are important. Recent research has demonstrated that spatial contiguity can be formulated in a mixed integer programming framework. Spatial compactness, however, is typically formulated in an approximate manner using parameters such as external border length or other shape indices of acquired land parcels. This paper first develops an alternative measure of spatial compactness utilizing the characteristics of the internal structure of a contiguous set of land parcels and then incorporates this new measure into a mixed integer program of contiguous land acquisition problems. A set of computational experiments are designed to demonstrate the use of our model in a land acquisition context.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.29 no.3
• /
• pp.145-152
• /
• 1987

This paper suggests a method for the analysis of box girders which are subject to the membrane and the plate bending actions, Moreover, the method is applied to the box girders under distributed loads which have various geometrical types of cross sections and are made out of different materials. The approach is based on the finite element technique in which the structure is considered to be a spatial assemblage of flat plate elements and the deformations of the plates are to be approximated with 9-noded parabolic isoparametric elements. The results are summarized as follows. 1.In all models, the larger the widths of top flange inside of web are, the larger the vertical deflections are. 2.The maximum transverse and longitudinal moments in the composite box girders are judged to be larger than those in the RC box girders. 3.The transverse and the longitudinal moments in top flange of composite box. girders are larger than those in that of the RC box girders. 4.The transverse and longitudinal moments in web and bottom flange of the composite box girders are estimated to be very small in compare to those in web and bottom flange of the RC box girders.

• Proceeding of KASS Symposium
• /
• 2006.05a
• /
• pp.142-152
• /
• 2006

The purpose of this study is to explore an inquisitive and innovative approach to structure and form, Calatrava's morphogenetic mechanism and to trace the ideas behind his working methods and his theoretical preoccupations. The bridges and buildings of S. Calatrava possess a breathtaking rhythm and of them some are designed to expand and contract like living organisms. The analogy Calatrava has used as a creative tool to mutate human bodies into arcing roof forms and bridge suspensions is introduced to illustrate the morphogenetic process. At the same time, the analysis used developing how to design frame structures foldable with brilliant mathematical solution is also investigated. Consequently, the potentialities of Calatrava's morphogenetic mechanism to invent new systems are generated by methodological hypothesis; analysis and analogy.

• Korean Journal of Remote Sensing
• /
• v.24 no.5
• /
• pp.473-481
• /
• 2008

This paper presents an approach to Back-propagation and Radial Basis Function neural network method with various training set for automatic vehicle detection from aerial images. The initial extraction of candidate object is based on Mean-shift algorithm with symmetric property of a vehicle structure. By fusing the density and the symmetry, the method can remove the ambiguous objects and reduce the cost of processing in the next stage. To extract features from the detected object, we describe the object as a log-polar shape histogram using edge strengths of object and represent the orientation and distance from its center. The spatial histogram is used for calculating the momentum of object and compensating the direction of object. BPNN and RBFNN are applied to verify the object as a vehicle using a variety of non-car training sets. The proposed algorithm shows the results which are according to the training data. By comparing the training sets, advantages and disadvantages of them have been discussed.

• Journal of KIISE:Databases
• /
• v.30 no.5
• /
• pp.451-463
• /
• 2003

Recently, there have been various research efforts to develop strategies for accelerating OLAP operations on huge amounts of spatio-temporal data. Most of the work is based on multi-tree structures which consist of a single R-tree variant for spatial dimension and numerous B-trees for temporal dimension. The multi~tree based frameworks, however, are hardly applicable to spatio-temporal OLAP in practice, due mainly to high management cost and low query efficiency. To overcome the limitations of such multi-tree based frameworks, we propose a new approach called Hilbert Cube(H-Cube), which employs fractals in order to impose a total-order on cells. In addition, the H-Cube takes advantage of the traditional Prefix-sum approach to improve Query efficiency significantly. The H-Cube partitions an embedding space into a set of cells which are clustered on disk by Hilbert ordering, and then composes a cube by arranging the grid cells in a chronological order. The H-Cube refines cells adaptively to handle regional data skew, which may change its locations over time. The H-Cube is an adaptive, total-ordered and prefix-summed cube for spatio-temporal data warehouses. Our approach focuses on indexing dynamic point objects in static spatial dimensions. Through the extensive performance studies, we observed that The H-Cube consumed at most 20% of the space required by multi-tree based frameworks, and achieved higher query performance compared with multi-tree structures.

• Korean Journal of Remote Sensing
• /
• v.28 no.6
• /
• pp.661-670
• /
• 2012

Urban forests provide great ecosystem services to population in metropolitan areas even though they occupy little green space in a huge gray landscape. Unfortunately, urbanization inherently results in threatening the green infrastructure, and the recent urbanization trends drew great attention of scientists and policy makers on how to preserve or restore green infrastructure in metropolitan area. For this reason, mapping the spatial distribution of the green infrastructure is important in urban environments since the resulting map helps us identify hot green spots and set up long term plan on how to preserve or restore green infrastructure in urban environments. As a preliminary step for mapping green infrastructure utilizing multi-source remote sensing data in urban environments, the objective of this study is to map vegetation volume by fusing LiDAR and multispectral data in urban environments. Multispectral imageries are used to identify the two dimensional distribution of green infrastructure, while LiDAR data are utilized to characterize the vertical structure of the identified green structure. Vegetation volume was calculated over the metropolitan Chicago city area, and the vegetation volume was summarized over 16 NLCD classes. The experimental results indicated that vegetation volume varies greatly even in the same land cover class, and traditional land cover map based above ground biomass estimation approach may introduce bias in the estimation results.

• Journal of Korean Society of Forest Science
• /
• v.111 no.3
• /
• pp.435-449
• /
• 2022

Forest canopy height is an indispensable vertical structure parameter that can be used for understanding forest biomass and carbon storage as well as for managing a sustainable forest ecosystem. Plot-based field surveys, such as the national forest inventory, have been conducted to provide estimates of the forest canopy height. However, the comprehensive nationwide field monitoring of forest canopy height has been limited by its cost, lack of spatial coverage, and the inaccessibility of some forested areas. These issues can be addressed by remote sensing technology, which has gained popularity as a means to obtain detailed 2- and 3-dimensional measurements of the structure of the canopy at multiple scales. Here, we reviewed both international and domestic studies that have used remote sensing technology approaches to estimate the forest canopy height. We categorized and examined previous approaches as: 1) LiDAR approach, 2) Stereo or SAR image-based point clouds approach, and 3) combination approach of remote sensing data. We also reviewed upscaling approaches of utilizing remote sensing data to generate a continuous map of canopy height across large areas. Finally, we provided suggestions for further advancement of the Korean forest canopy height estimation system through the use of various remote sensing technologies.

• Journal of Korea Spatial Information System Society
• /
• v.5 no.1 s.9
• /
• pp.65-74
• /
• 2003

Location-based service is an important spatiotemporal database application area that provides the location-aware information of wireless terminals via positioning devices such as GPS. With the rapid advances of wireless communication systems, the requirement of mobile application areas including traffic, mobile commerce and supply chaining management became the center of attention for various research issues in spatiotemporal databases. In this paper we present the A-Quadtree, an efficient indexing method for answering location-based queries where the movement vector information (e.g., speed and velocity) is not presented. We implement the A-Quadtree with an index structure for object identifiers as a.Net component to apply the component to multiplatforms. We present our approach and describe the performance evaluation through various experiments. In our experiments, we compare the performance with previous approaches and show the enhanced efficiency of our method.

• The Korean Journal of Applied Statistics
• /
• v.30 no.3
• /
• pp.417-426
• /
• 2017

It is important to predict the flowering dates of Japanese cherry and autumnal dates in Korea. Flowering date is decided by heating requirement with daily maximum and minimum temperature used to calculate the pre-determined heating requirements for flowering. Recent, changes in climate have impacted the flowering season of Japanese cherry in Korea. When compared with the current normal, the flowering of Japanese cherry is expected to be about 10 days earlier than in near future normal years. In this paper, we first consider a linear model based on meteorological data that predicts the flowering date and then incorporate a spatial structure into the model. Real data analysis indicates that the proposed approach provides more reasonable predicted dates.