• Journal of the Korean GEO-environmental Society
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• v.9 no.5
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• pp.15-20
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• 2008

Compressibility of the marine clay was mainly studied velocity of consolidation and numerical analysis by this time but studies of reevaluated from the field measurement data was a little. For last three years, areal fills and extensive field instrumentations including settlement and pore water pressure were performed in the site of the Youngsan River estuary site, South Korea. From the settlement data, field consolidation curves for sub-layers were reconstructed. Effective surcharge loads during the staged loadings were calculated using the fill heights and the excess pore water pressures in the ground. In the numerical analysis (PLAXIS), prefabricated vertical drains were also simulated. Laboratory, field, and numerical analysis showed good agreements in compressibility. Due to different conditions and limitations of the clay was the same range of the oedometer tests.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.106-119
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• 2013

As open source can reduce costs and apply to various fields rapidly, many countries have actively adopted open source. However, geo-spatial open source in Korea is not actively promoted yet comparing to other countries having similar infra environments. In this study, we analyzed the perception of geo-spatial open source, utilization status, the development possibility and future direction using questionnaire survey completed by experts dealing with spatial information. The survey result shows that many experts have experiences of using geo-spatial open source but they got a lack of understanding about open source license or regulations and only a few people got professional training. Insufficient references, the difficulty of maintenance, lack of support and low technical reliability have hindered the adoption of geo-spatial open source. Only some part of geo-spatial open source software or libraries in some field have been used in the country. However, many researchers rate highly development potential and plan to use geo-spatial open source soon. If user's convenience, reference materials, technical trust and policy support are improved, open source field for spatial information will be developed greatly in the future.

• Korean Journal of Geomatics
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• v.5 no.1
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• pp.43-49
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• 2005

It is well known that GPS technique can be used for high accuracy leveling positioning if a precise geoid model is available to use at a surveying point. In this study, KOGD2003 geoid model was developed in and around Korean peninsula and this geoid model could be achieved by combining GPS/leveling data with the formerly developed KOGD2002. To this end, the software for orthometric height obtaining and geodetic datum transformation has been implemented with the visual C++ language, what we called GPS-GeoL v.1.0. In order to evaluate the performance and the accuracy of the software, GPS field tests were carried out in the Korean second-order leveling network over Chollabukdo area. Results of the tests have shown that the mean value of the differences between outputs of the software developed in this research and officially announced orthometric heights by NGII (National Geographic Information Institute) was 0.0221 m and also those of RMS was 0.0332 m. Therefore, it was possible to conclude that the KOGD2003 and GPS-GeoL v.1.0 software could be used to determine orthometric heights for civil construction field applications with cm-level accuracy.

• The KIPS Transactions:PartD
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• v.8D no.5
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• pp.516-572
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• 2001

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

• Journal of the Korean GEO-environmental Society
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• v.14 no.3
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• pp.13-17
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• 2013

Determination of geotechnical characteristics of soil is either to use the field samples to measure the characteristics of soil through laboratory test or measuring the characteristics directly in the field. Field test can be derived similar value by considering characteristics of site and laboratory test can be confirmed the characteristic of soil by testing with field samples. This article describes relative density as the measure of compaction for cohesionless soils and presents several simple and mathematical relationships to help engineers estimate needed parameters for relative density calculations. The main purpose of this research is to investigate possible correlations between coefficient of uniformity, coefficient of curvature, maximum and minimum void ratio, mean grain size. Results show a linear relationship between the minimum and maximum void ratios and a power function relationship between coefficient of uniformity and the limiting void ratios. Void ratio range, which is the difference between the maximum and minimum void ratios, appeared to be log normally distributed but showed no simple mathematical fit to the data. these results were shown to help engineers estimate needed parameters for relative density calculations.

• Journal of the Korean GEO-environmental Society
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• v.12 no.3
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• pp.37-46
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• 2011

To investigate the applicability of Precious Slag Ball as the alternative material such as vertical drains, it is necessary to check the drainage effect of it in the field construction. In order to attain an successful design it is important to predict problems encountered in field construction. Accordingly, in this study the laboratory tests were executed under different conditions before applying of the field. 4 cases including Precious Slag Ball, sand+Precious Slag Ball, pack Precious Slag Ball and sand as vertical drains were conducted, and under the base of the laboratory tests the field test was executed and analyzed. By the upper results it is apposite to use Precious Slag Ball as vertical drains.

• Journal of the Korean GEO-environmental Society
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• v.5 no.2
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• pp.33-39
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• 2004

Most of pile foundations are a condition of fixed head on pile, but lateral loading test of pile have performed to free head on generally. This study performed field lateral loading test accompanying lateral displacement by depth of pile for two cases(fixed head and free head) and analyzed lateral behavior of large drilled shaft. Furthermore compared theoretical equation with result of lateral loading test.

• Journal of the Semiconductor & Display Technology
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• v.7 no.4
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• pp.57-62
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• 2008

Image retrieval is one of the most exciting and rapidly growing research issues in the field of multimedia technology. This paper proposes a new method that performs search the relevant images by using query-by-example. The proposed method for search and retrieval of images utilizes the location information where the image had been taken. The system associates the photo images with their corresponding GPS coordinates that are used as metadata for searching. Experimental results show that the proposed method demonstrates better performance improving up to 59% of average recall and 49% of average precision. Moreover, we learned from the experimental results geo-location information embedded within the image header is more effective and positive on the search and storage.

• Economic and Environmental Geology
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• v.45 no.3
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• pp.335-346
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• 2012

This study investigates the differences of recognition about geo-technologies outcome between experts and nonexperts. Based on these findings, this study would offer suggestions for future communication strategies on research outcome in a various field of scientific research as well as KIGAM. The result shows that there are differences between expert and nonexpert in the level of recognition about geoscience research outcome. The findings of this study emphasize the needs for recognizing the concept that geo-technologies are directly related to people's lives and external communication is necessary.

• Geomechanics and Engineering
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• v.23 no.1
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• pp.61-69
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• 2020

The uniaxial compressive strength (UCS) of rock is a basic parameter in underground engineering design. The disadvantages of this commonly employed laboratory testing method are untimely testing, difficulty in performing core testing of broken rock mass and long and complicated onsite testing processes. Therefore, the development of a fast and simple in situ rock UCS testing method for field use is urgent. In this study, a multi-function digital rock drilling and testing system and a digital core bit dedicated to the system are independently developed and employed in digital drilling tests on rock specimens with different strengths. The energy analysis is performed during rock cutting to estimate the energy consumed by the drill bit to remove a unit volume of rock. Two quantitative relationship models of energy analysis-based core drilling parameters (ECD) and rock UCS (ECD-UCS models) are established in this manuscript by the methods of regression analysis and support vector machine (SVM). The predictive abilities of the two models are comparatively analysed. The results show that the mean value of relative difference between the predicted rock UCS values and the UCS values measured by the laboratory uniaxial compression test in the prediction set are 3.76 MPa and 4.30 MPa, respectively, and the standard deviations are 2.08 MPa and 4.14 MPa, respectively. The regression analysis-based ECD-UCS model has a more stable predictive ability. The energy analysis-based rock drilling method for the prediction of UCS is proposed. This method realized the quick and convenient in situ test of rock UCS.