• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.163-173
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• 2014

When evaluating the spatial resolution images and evaluation of low contrast resolution using CT standard phantom, and might present a automated quantitative evaluation method for minimizing errors by subjective judgment of the evaluator be, and try to evaluate the usefulness. 120kVp and 250mAs, 10mm collimation, SFOV(scan field of view) of 25cm or more than, exposure conditions DFOV(display field of view) of 25cm, and were evaluated the 24 passing images and 20 failing images taken using a standard reconstruction algorithm by using the Nuclear Associates, Inc. AAPM CT Performance Phantom(Model 76-410). Quantitative evaluation of low contrast resolution and spatial resolution was using an evaluation program that was self-developed using the company Mathwork Matlab(Ver. 7.6. (R2008a)) software. In this study, the results were evaluated using the evaluation program that was self-developed in the evaluation of images using CT standard phantom, it was possible to evaluate an objective numerical qualitative evaluation item. First, if the contrast resolution, if EI is 0.50, 0.51, 0.52, 0.53, as a result of evaluating quantitatively the results were evaluated qualitatively match. Second, if CNR is -0.0018~-0.0010, as a result of evaluating quantitatively the results were evaluated qualitatively match. Third, if the spatial resolution, as a result of using a image segmentation technique, and automatically extract the contour boundary of the hole, as a result of evaluating quantitatively the results were evaluated qualitatively match.

• Journal of Korea Multimedia Society
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• v.4 no.3
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• pp.197-204
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• 2001

In order to increase the performance of spatial database systems, a spatial indexing method is necessary to manage spatial objects efficiently in both dynamic and static environments. A spatial indexing method considering a spatial locality is required to increase the retrieval performance. And the spatial locality is related to the location property of objects. The previous spatial indexing methods did not consider the circular location property of objects. In this paper, we introduce the CR-Tree that is a spatial index structure for clustering spatially adjacent objects in which a search space is constructed with the circular and linear domains. Using a spatial index structure considered a circular location property of objects, we show that high hit ratio and bucket utilization are increased through the simulation.

• Journal of the Korean housing association
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• v.3 no.2
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• pp.13-19
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• 1992

The purpose of this study is to grasp spatial effects of colours in interior design. The visual feeling in the 1/10 living room scale models that are different in the colour combination of ceilings, walls and floors is judged using a semantic scale of the fifteen adjectives. The major findings are as follows; 1) As a result of factor analysis, three dimensions, "evaluation", "activity" and "warmness" are extracted. Dimension 1, "evaluation", is most greatly affected by the chroma and hue of the room colour, dimension 2, "activity", by the hue and value, by the difference in hue and value of ceilings, walls and floors, dimensions 3, "warmness", by mainly the hue of the rooms. 2) Concerning the spatial effects of colour, the subjects felt higher vlaue with relevance to the hue of GY, Y, low chroma and high value. The room colours other than walls is felt more comfortable in similar colour, especially hue and value.re comfortable in similar colour, especially hue and value.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.178-182
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• 2007

In this study, we evaluated current raingauge network of Soyanggang dam region applying spatial-correlation analysis and Entropy theory to recommend an optimized raingauge network. In the process of analysis, correlation distance of raingauge stations is estimated and evaluated via spatial-correlation method and entropy method. From this correlation distances, respective influencing radii of each dataset and each methods is assessed. The result of correlation and entropy analysis has estimated correlation distance of 25.546km and influence radius of 7.206km, deducing a decrease of network density from $224.53km^2$ to $122.47km^2$ which satisfy the recommended minimum densities of $250km^2$ in mountainous regions(WMO, 1994) and an increase of basin coverage from 59.3% to 86.8%. As for the elevation analysis the relative evaluation ratio increased from 0.59(current) to 0.92(optimized) resulting an obvious improvement.

• Journal of Korea Spatial Information System Society
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• v.9 no.2
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• pp.1-11
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• 2007

Recently, with the development of collecting methods of spatial data, the spatial data is produced, circulated, and used in various fields of industry and research. To manage the mass spatial data efficiently, the researches on extension of the existing commercial DBMS, such as ESRI's ArcSDE or Oracle's Oracle Spatial, is making progress actively. However, the usage of the extension of the commercial DBMS Incurs an additional expense and causes an interoperability problem due to differences in spatial data types and spatial operators. Therefore, in this paper, we developed an OpenGIS Spatial Interface for Oracle, which supports a standard interface by fellowing the "Simple Features Specification for SQL" proposed by OGC(Open Geospatial Consortium). Since the OpenGIS Spatial Interface provides all spatial data types and spatial operators proposed in "Simple Features Specification for SQL", users can manage mass spatial data of Oracle efficiently by using the standard interface without additional expense. In addition, we proved that the OpenGIS Spatial Interface is superior to the Oracle Spatial in the response time through the performance evaluation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.2
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• pp.129-136
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• 1999

The quality of image classification results is not always uniform over entire image. Thus, this study proposes the concept of ISDd (Index of Spatial Distribution by distance) and ISDs (ISD by scatteredness) for the evaluation of unevenness of result quality, and spatial distribution of satellite image classification errors. The ISDd is indexed mean distance of misclassified pixels and the ISDs is statistical indicator of scatteredness of misclassified pixels. In this study, the ISDd and the ISDs are calculated and evaluated for some satellite images, then misclassified area is extracted and the reasons of misclassification are examined. As the result of this study, using both the ISDd and the ISDs, the basis of decision on adoption/rejection of classification results is offered at sub-image level by evaluation of the local aggregation of misclassified pixels. Using Index of Spatial Distribution. as well as overall classification accuracy, users can understand the spatial distribution of misclassified pixels, and can have the additional criterion of the judgement on suitability and reliability of classification results.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1046-1053
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• 2006

In the large scale recent reclaiming works performed within the wide spatial boundary, evaluation of long-term consolidation settlement and residual settlement of the whole construction area is sometimes made with the results of the limited ground investigation and measurement. Then the reliability of evaluation has limitations due to the spatial uncertainty. Additionally, in case of large scale deep excavation works such as urban subway construction, there are a lot of hazardous elements to threaten the safety of underground pipes or adjacent structures. Therefore it is necessary to introduce a damage prediction system of adjacent structures and others. For the more accurate analysis of monitoring information in the wide spatial boundary works and large scale urban deep excavations, it is necessary to perform statistical and spatial analysis considering the geographical spatial effect of ground and monitoring information in stead of using diagrammatization method based on a time-series data expression that is traditionally used. And also it is necessary that enormous ground information and measurement data, digital maps are accumulated in a database, and they are controlled in a integrating system. On the abovementioned point of view, we developed Geomonitor 2.0, an Internet based real time monitoring program with a new concept by adding GIS and geo-statistical analysis method to the existing real time integrated measurement system that is already developed and under useful use. The new program enables the spatial analysis and database of monitoring data and ground information, and helps the construction- related persons make a quick and accurate decision for the economical and safe construction.

• Journal of Korea Spatial Information System Society
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• v.1 no.1 s.1
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• pp.29-37
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• 1999

Recently, brisk up the construction of the spatial information, many people highly concern to tile information circulation of GIS. Each system like GIS has a structure of the information circulation to itself. In this paper, we study on the performance evaluation method of tile structure which to circulate tile spatial information based on the internet. To do this, we hypothesize values of content and scale of the geo-spatial information on each internet network and volumes of the information to circulate between internet networks. Then we suggest a method to evaluate the performance of the structure to aid the circulation of spatial information based on queueing model. Henceforth, with the volumes of data stored and circulated information of each GIS, this method can help to design the structure to circulate the GIS information more efficiently.

• Journal of Wetlands Research
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• v.16 no.1
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• pp.103-112
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• 2014

Area average rainfall estimation is important to determine the exact amount of the available water resources and the essential input data for rainfall-runoff analysis. Like that, the necessary criterion for accurate area average rainfall estimate is the uniform spatial distribution of raingauge network. In this study, we suggest the spatial distribution evaluation methodology of raingauge network to estimate better area average rainfall and after the suggested method is applied to Han River and Geum River basin. The spatial distribution of rainfall network can be quantified by the nearest neighbor index. In order to evaluate the effects of the spatial distribution of rainfall network by each basin, area average rainfall was estimated by arithmetic mean method, the Thiessen's weighting method and estimation theory for 2013's rainfall event, and evaluated the involved errors by each cases. As a result, it can be found that the estimation error at the best basin of spatial distribution was lower than the worst basin of spatial distribution.

• Journal of Korean Association for Spatial Structures
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• v.17 no.4
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• pp.20-26
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• 2017