• Journal of Internet Computing and Services
• /
• v.1 no.1
• /
• pp.47-62
• /
• 2000

Geographic Information System(GIS) deal with data which can potentially be useful for a wida range of applications. However, the information needs of each application usually vary, specially in resolution, detail level, and representation style, as defined in the modeling phase of the geographic database design. To be able to deal with such diverse needs, the GIS must after features that allow multiple representations for each geographic entity of phenomenon. This paper addresses the problem of formal definition of the objects and their relationships on geographical information systems. The geographical data is divided in two main classes: geo-objects and geo-fields, which describe discrete and continuous representations of spatial reality. I will study the classes and the roles of relationships over geo-fields, geo-objects and nongeo-objects. Therefore, this paper will contribute the efficient design of geographical class hierarchy schema by means of formalizing attribute-domains of classes.

• Journal of Korea Spatial Information System Society
• /
• v.12 no.1
• /
• pp.37-48
• /
• 2010

In this paper, we analyze the shortcomings of the previous declustering methods, which are based on grid-like partitioning and a mapping function from a cell to a disk number, for high-dimensional space and propose a solution. The problems arise from the fact that the number of splitting is small(for the most part, binary-partitioning is sufficient), and the side length of a range query whose selectivity is small is quite large. To solve this problem, we propose a mathematical model to estimate the performance of a grid-like partitioning method. With the proposed estimation model, we can choose a good grid-like partitioning method among the possible schemes and this results in overall improvement in declustering performance. Several experimental results show that we can improve the performance of a previous declustering method up to 2.7 times.

• Journal of Korea Spatial Information System Society
• /
• v.12 no.1
• /
• pp.100-104
• /
• 2010

Recently with advent of Web 2.0, RESTful Web Services are becoming increasing trend to emphasize Web as platform. There are already many services and the number of service increases in very fast pace. So it is difficult to find the service what we want by keyword based search. To solve this problem, we developed the search method using sem antic technologies about RESTful Web Services. For that, first we define the system structure and model the description format based on the integrated search system for OpenAPIs, and then we add Semantic Markup (tagging, semantic annotation) on the HTML description pages. Next we extract RDF document from them and store it in service repository. Based on the keywords that are extended by means of ontology, the developed system provides more purified and extended results than similarity-based keyword searching system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.18 no.1
• /
• pp.67-73
• /
• 2000

The water quality of inland stream is polluting with industrialization and urbanization, and with that water quality of lake also deteriorated, to manage water quality pollution problem of lake, new water quality management method is needed. As a pilot study of the method that manage water quality of lake using GSIS(Geo-Spatial Information System), we study the method which automatically extract the hydraulic characteristic informations of lake in GSIS environment. Also, as an example of practical use of the extracted hydraulic characteristic information of lake, we carry out the characteristic analysis of waterbody flow using finite different method. With the automation the extraction procedure of hydraulics characteristic information needed in characteristic analysis of waterbody flow, we carried out the analysis efficiently. Particularly, with the extraction of section information on lake not in layout form, in analyzable form, we make the analysis that section information of lake was indispenably required(e.g. stratification analysis) possible in GSIS environment.

• Journal of Korean Society of Steel Construction
• /
• v.14 no.4
• /
• pp.509-518
• /
• 2002

In order to perform the spatial buckling and static analysis of the nonsymmetric thin-walled beam-column element, improved exact static stiffness matrices were evaluated using equilibrium equation and force-deformation relationships. This numerical technique was obtained using a generalized linear eigenvalue problem, by introducing 14 displacement parameters and system of linear algebraic equations with complex matrices. Unlike the evaluation of dynamic stiffness matrices, some zero eigenvalues were included. Thus, displacement parameters related to these zero eigenvalues were assumed as polynomials, with their exact distributions determined using the identity condition. The exact displacement functions corresponding to three loadingcases for initial stress-resultants were then derived, by consistently combining zero and nonzero eigenvalues and corresponding eigenvectors. Finally, exact static stiffness matrices were determined by applying member force-displacement relationships to these displacement functions. The buckling loads and displacement of thin-walled beam were evaluated and compared with analytic solutions and results using ABAQUS' shell element or straight beam element.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.15 no.12 s.105
• /
• pp.1378-1388
• /
• 2005

Spatial control of sound is essential to deliver better sound to the listener's position in space. As it can be experienced in many listening environments. the quality of sound can not be manifested over every Position in a hall. This motivates us to control sound in a region we select. The primary focus of the developed method has to do with the brightness and contrast of acoustic image in space. In particular, the acoustic brightness control seeks a way to increase loudness of sound over a chosen area, and the contrast control aims to enhance loudness difference between two neighboring regions. This enables us to make two different kinds of zone - the zone of quiet and the zone of loud sound - at the same time. The other perspective of this study is on the direction of sound. It is shown that we can control the direction of perceived sound source by focusing acoustic energy in wavenumber domain. To begin with, the proposed approaches are formulated for pure-tone case. Then the control methods are extended to a more general case, where the excitation signal has broadband spectrum. In order to control the broadband signal in time domain, an inverse filter design problem is defined and solved in frequency domain. Numerical and experimental results obtained in various conditions certainly validate that the acoustic brightness, acoustic contrast, direction of wave front can be manipulated for some finite region in space and time.

• Journal of Korea Spatial Information System Society
• /
• v.11 no.4
• /
• pp.9-18
• /
• 2009

R&D businesses lead by a government of each countries are recognized as important businesses that may affect the destinies of the nation. However, the process of developing a new business has not been so favorable as the process was primarily managed by engineers who concentrate on research development. The problem was solved by applying a business model regarding outcomes of a developed research. Yet it is difficult to apply the business model methods that are commonly used for enterprises to government's research businesses due to their unique research development characteristics. Therefore, it is developed a business model methodology for national R&D project in this study. In addition, the methodology applies to a sub-project of Korean Land Spatialization Program(KLSP) organized by Ministry of Land, Transport and Maritime Affairs to verify the possibility of practical application.

• Journal of Korea Spatial Information System Society
• /
• v.7 no.2 s.14
• /
• pp.67-79
• /
• 2005

For tracing tag locations, the trajectories should be modeled and indexed in a radio frequency identification (RFID) system. The trajectory of a tag is represented as a line that connects two spatiotemporal locations captured when the tag enters and leaves the vicinity of a reader. If a tag enters but does not leave a reader, its trajectory is represented only as a point captured at entry. Because the information that a tag stays in a reader is missing from the trajectory represented only as a point, it is impossible to find the tag that remains in a reader. To solve this problem we propose the data model in which trajectories are defined as intervals and new index scheme called the Interval R-tree. We also propose new insert and split algorithms to enable efficient query processing. We evaluate the performance of the proposed index scheme and compare it with the R-tree and the R*-tree. Our experiments show that the new index scheme outperforms the other two in processing queries of tags on various datasets.

• Journal of Korean Society for Geospatial Information Science
• /
• v.19 no.2
• /
• pp.55-61
• /
• 2011

The land use has been changed artificially and caused the result of temperature increase of city compared with the outside of city or region of park and forest. The purpose of this research is to analyze the change of the urban surface temperature with land use zoning in Jinju using Landsat TM/$ETM^+$ imagery and to provide the correlation between NDVI(Normalized Difference Vegetation Index) and urban surface temperature change. The results presented that the spatial distribution of urban surface temperature was depending on the change of NDVI values on land use zoning. Considering to the average temperature by land use zoning, industrial area was the highest temperature but green area was the lowest temperature. Also as a result of comparing the correlation between surface temperature and NDVI, the green and residential area had higher correlation values than the commercial and industrial area. These results will be played a part as one of the major factors for implementing the sustainable urban planning considering the urban heat island effect problem.

• Journal of Korea Spatial Information System Society
• /
• v.11 no.4
• /
• pp.39-46
• /
• 2009

Generally, Path-finding algorithms which use heuristic function may occur a problem of the increase of exploring cost in case of that there is no way determined by heuristic function or there are 2 way more which have almost same cost. In this paper, we propose an abstract graph for path-finding with dynamic information. The abstract graph is a simple graph as real road network is abstracted. The abstract graph is created by fixed-size cells and real road network. Path-finding with the abstract graph is composed of two step searching, path-finding on the abstract graph and on the real road network. We performed path-finding algorithm with the abstract graph against A* algorithm based on fixed-size cells on road network that consists of 106,254 edges. In result of evaluation of performance, cost of exploring in path-finding with the abstract graph is about 3~30% less than A* algorithm based on fixed-size cells. Quality of path in path-finding with the abstract graph is, However, about 1.5~6.6% more than A* algorithm based on fixed-size cells because edges eliminated are not candidates for path-finding.