• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.35 no.2
• /
• pp.75-80
• /
• 2017

Recently, there has been growing interest in spatial data that combines information and communication technology with smart cities. The high-precision LiDAR (Light Dectection and Ranging) equipment is mainly used to collect three-dimensional spatial data, and the acquired data is also used to model geographic features and to manage plant construction and cultural heritages which require precision. The LiDAR equipment can collect precise data, but also has limitations because they are expensive and take long time to collect data. On the other hand, in the field of computer vision, research is being conducted on the methods of acquiring image data and performing 3D reconstruction based on image data without expensive equipment. Thus, precise 3D spatial data can be constructed efficiently by collecting and processing image data using CCTVs which are installed as infrastructure facilities in smart cities. However, this method can have an accuracy problem compared to the existing equipment. In this study, experiments were conducted and the results were analyzed to increase the number of extracted matching points by applying the feature-based method and the area-based method in order to improve the precision of 3D spatial data built with image data acquired from stereo CCTVs. For techniques to extract matching points, SIFT algorithm and PATCH algorithm were used. If precise 3D reconstruction is possible using the image data from stereo CCTVs, it will be possible to collect 3D spatial data with low-cost equipment and to collect and build data in real time because image data can be easily acquired through the Web from smart-phones and drones.

• Journal of the Korean GEO-environmental Society
• /
• v.7 no.6
• /
• pp.133-143
• /
• 2006

A fully coupled effective stress dynamic analysis procedure for modeling seismic liquefaction on slope is presented. An elasto-plastic formulation is used for the constitutive model UBCSAND in which the yield loci are radial lines of constant stress ratio and the flow rule is non-associated. This is incorporated into the 2D version of Fast Lagrangian Analysis of Continua (FLAC) by modifying the existing Mohr-Coulomb model. This numerical procedure is used to simulate centrifuge test data from the Rensselaer Polytechnic Institute (RPI). UBCSAND is first calibrated to cyclic direct simple shear tests performed on Nevada sand. Both pre- and post-liquefaction behaviour is captured. The centrifuge test is then modeled and the predicted accelerations, excess porewater pressures, and displacements are compared with the measurements. The results are shown to be in general agreement. The procedure is currently being used in the design of liquefaction remediation measures for a number of dam, bridge, tunnel, and pipeline projects in Western Canada.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.1285-1290
• /
• 2008

The interest in use of new field of energy and unused existing potential energy has been raised in number of advanced countries including South Korea. As a respond of the interest and the following reactions, a new technology which helps to reduce bad environmental factors and decrease national energy consumption rate in the way of extract cold-heat energy in dam water. This research focuses on a method that enables taking the water flows in desirable temperature range whilst keeping water temperature boundaries of bottom level water. The analysis was made in simulating on CFD. In order to keep the temperature boundary level, a deep well pump was set in piping in the simulation. As the significant result, the most alteration in temperature was found when the smallest size of pipe was plumbed. However, when the flow has small value of velocity, no matter how big the piping size was, the temperature variation was negligible. Therefore, possible hypothesis was made as bigger piping as fast flow will have better function in the way to keep the temperature boundary level.

• Journal of Korean Society for Geospatial Information Science
• /
• v.8 no.1 s.15
• /
• pp.105-110
• /
• 2000

Since the advent of high resolution satellite image, possibilities of applying various human interpretation mechanism to these images have increased. Also many studies about these possibilities in many fields such as computer vision, pattern recognition, artificial intellegence and remote sensing have been done. In this field of these studies, texture is defined as a kind of quantity related to spatial distribution of brightness and tone and also plays an important role for interpretation of images. Especially, methods of obtaining texture by statistical model have been studied intensively. Among these methods, texture measurement method based on cooccurrence matrix is highly estimated because it is easy to calculate texture features compared with other methods. In addition, these results in high classification accuracy when this is applied to satellite images and aerial photos. But in the existing studies using cooccurrence matrix, features have been chosen arbitrarily without considering feature variation. And not enough studies have been implemented for appropriate resolution selection in which cooccurrence matrix can extract texture. Therefore, this study reviews the concept of cooccurrence matrix as a texture measurement method, evaluates usefulness of several features obtained from cooccurrence matrix, and proposes appropriate resolution by investigating variance trend of several features.

• Journal of Environmental Science International
• /
• v.19 no.1
• /
• pp.39-45
• /
• 2010

When the Juam multipurpose dam which is connected with existing large water supply facilities is finished, water environment is changed from stream to lake. The changed quality of water should be examined. In this study, the result of water quality forecasting is analysed and an effective management plan of water quality is presented. Tn this study, the WASPS model that is a dynamic water quality simulation model was selected to forecast the water quality. This model forecasts movement of change of pollutants. For an application of the model, the subject areas were divided into seventeen sub-areas by considering change temperature depending measuring points and on depth of water. Meteorological data collected by the meteorological observatory and data about quality measured by the Korea Water Resources Development Corporation were used for an operation of the model. As a result of quality examination through quality data and estimated pollutant loading, the water quality environment criterion was grade II and the nutritive condition was measured as meso-graphic grade. In this study, an effective management was planned to improve water quality by reducing pollution load. According to the result of examination, when more than 30% of BOD was reduced it was recorded that the environment standard of water quality was improved to the second grade.

• Journal of the Institute of Electronics Engineers of Korea TE
• /
• v.37 no.1
• /
• pp.50-57
• /
• 2000

By supporting wireless communication technology, there is gradually expansion of the commercial application for Wireless Local Loop(WLL) technology, which is to replace existing telephone line with wireless one. The WLL system application helps a operator to have merits of the installation and maintenance of line and also a subscriber to make a high speed value-added service. As mentioned above reasons for both sides, many manufactories and operators are concerned with development and application respectively. This paper presents hardware implementation of Radio Port Controller(RPC) and also describes the system configuration, functions, and Inter Processor Communication(IPC) structure of RPC. We performed inter-module communication test via IPC backplane bus. And inter-module integration test also completed through data communication and signal waveform measurement repeatedly.

• Journal of Korea Water Resources Association
• /
• v.32 no.2
• /
• pp.143-152
• /
• 1999

South-eastern part of Kyungbuk Province is suffering from lack of suitable water development sources due to geographic condition and insufficient water sources condition. In order to find an appropriate solution, extensive studies are carried out such as investigation of new dam sites, regional water supply system, modification of existing water supply system, rehabilitation of old water resources structures and development of off-stream reservoirs. The network optimization model is applied for evaluation of the newly suggested water development alternatives. The results show that if water supply system is constructed until 2011, the reliability of water supply to Pohang and Kyungju region will be more than 95% and the network optimization model can be used to analyse the management of water resources system considering water rights or priority orders.

• Water for future
• /
• v.24 no.4
• /
• pp.49-58
• /
• 1991

Flood routing in the Youngsan River was performed for the flood event of July, 1989 by two finite difference methods. The Saint Venant eq., a kind of hyperbolic partial differential equation is employed as governing equation and the explicit scheme (Leap Frog) and implicit scheme (Preissmann) are used to discretize the GE. As for the external boundary conditions, discharge and tidal elevation are upstream and downstream BC, respectively and estuary dam is included in internal BC. Lateral inflows and upstream discharges are the hourly results from storage function method, At Naju station, a Relatively upstream points in this river, the outputs are interpreted as good ones by comparing two numerical results of FDMs with the observed data and the calibrated results by storage function method. and two computational results are compared at the other sites, from middle stream and downstream points, and thus are considered reliable. Therefore, we can conclude from this research that these numerical models are adaptable in simulating and forecasting the flood in natural channels in Korea as well as existing hydrologic models. And the study about optimal gate control at the flood time is expected as further study using these models.

• Journal of Korea Water Resources Association
• /
• v.35 no.6
• /
• pp.797-805
• /
• 2002

The EV ROM, a joint reservoir operation model for flood control that accounts for the downstream flow condition, has been introduced in the preceding article (Shin et al, 2000). A joint reservoir operation model computer program for the Geum river basin, developed by FORTRAN Power Station 4.0 using the EV ROM, is hereby presented. Three case studies of flood control by joint operation of the Yongdam and Daechung Multipurpose Dams in the Geum river basin revealed that the performance of the EV ROM was superior to the existing Rigid ROM and Technical ROM. This is because the EV ROM can account for the downstream flow condition as well as the upstream inflow and the reservoir water level. In order to apply for various floods events in the future, consistent improvement of the developed EV ROM and efforts for more accurate rainfall prediction are required.

• Korean Journal of Remote Sensing
• /
• v.26 no.1
• /
• pp.39-45
• /
• 2010

This study used the keypoint observed simultaneously on two images and on twodimensional intensity image data, which was obtained along with the two point clouds data that were approached for automatic focus among points on terrestrial LiDAR data, and selected matching point through SIFT algorithm. Also, for matching error diploid, RANSAC algorithm was applied to improve the accuracy of focus. As calculating the degree of three-dimensional rotating transformation, which is the transformation-type parameters between two points, and also the moving amounts of vertical/horizontal, the result was compared with the existing result by hand. As testing the building of College of Science at Konkuk University, the difference of the transformation parameters between the one through automatic matching and the one by hand showed 0.011m, 0.008m, and 0.052m in X, Y, Z directions, which concluded to be used as the data for automatic focus.