• Journal of Broadcast Engineering
• /
• v.17 no.4
• /
• pp.640-658
• /
• 2012

One of the existing terrestrial multi-channel DTV service frameworks, called KoreaView, provides four programs, composed of MPEG-2 based one HD video and H.264/AVC based three SD videos within one single 6MHz frequency bandwidth. However the additional 3 SD videos can not provide enough quality due to its reduced spatial resolution and low target bitrates. In this paper, we propose a framework, which is called a terrestrial multi-channel high quality hybrid DTV service, to overcome such a weakness of KoreaView services. In the proposed framework, the three additional SD videos are encoded based on an H.264/SVC Spatial Base layer, which is compliant with H.264/AVC, and are delivered via broadcasting networks. On the other hand, and the corresponding three additional HD videos are encoded based on an H.264/SVC Spatial Enhancement layer, which are transmitted over broadband networks such as Internet, thus allowing the three additional videos for users with better quality of experience. In order to verify the effectiveness of the proposed framework, various experimental results are provided for real video contents being used for DTV services. First, the experimental results show that, when the SD sequences are encoded by the H.264/SVC Spatial Base layer at a target bitrate of 1.5Mbps, the resulting PSNR values are ranged from 34.5dB to 42.9dB, which is a sufficient level of service quality. Also it is noted that 690kbps-8,200kbps are needed for the HD test sequences when they are encoded in the H.264/SVC Spatial Enhancement layer at similar PSNR values for the same HD sequences encoded by MPEG-2 at a target bitrate of 12 Mbps.

• Journal of the Korean Society of Radiology
• /
• v.10 no.3
• /
• pp.215-222
• /
• 2016

X-ray mammography is the most effective method for the diagnosis of calcified lesions of various breast diseases. To reduce patient dose and to obtain optimal image required for diagnosis, the performance of the mammography system should be maintained continuously. Because the target (anode) angle of the X-ray tube is measured from the central X-ray, the effective angle can be slightly different in view of the position on the detector, which can result in degrading spatial resolution of the imaging within the field of view. In this study, we measured the MTF to examine spatial resolution for positions on the detector in the digital mammography system. For a tungsten wire of $50{\mu}m$ diameter, the highest spatial frequency was obtained. It meant that a wire diameter for measuring MTF through LSF should be small compared to the pixel size of the detector used in the mammography system. The spatial resolution showed slightly different performance according to positions on the detector. The center position gave the best spatial resolution and positions away from the center showed the degraded performance although the difference of the spatial resolution was small. The effective focal spot size of the full width at half maximum also showed similar result. It concluded that the slightly increase of the effective focal spot size gave the degradation of the spatial resolution for positions on the detector.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.24 no.4
• /
• pp.184-193
• /
• 2021

The system for managing spatial data updates the existing information by extracting only the information that is different from the existing information for the newly obtained spatial information file to update the stored information. In order to extract only objects that have changed from existing information, it is necessary to compare whether there is any difference from existing information for all objects included in the newly obtained spatial information file. This study was conducted to improve this total inspection method in a situation where the amount of spatial information that is frequently updated increases and data update is required at the national level. In this study, before inspecting individual objects in a new acquisition space information file, a method of determining whether individual space objects have been changed only by the information in the file was considered. Spatial data files have structured data characteristics different from general image or text document files, so it is possible to determine whether to change the file unit in a simpler way compared to the existing method of creating and managing file hash. By reducing the number of target files that require full inspection, it is expected to improve the use of resources in the system by saving the overall data quality inspection time and saving data extraction time.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.22 no.5
• /
• pp.182-199
• /
• 2023

Since 2021, government departments have been promoting Automated Driving Technology Development and Innovation Project as national research and development(R&D) project. The automated vehicles and service technologies developed as part of these projects are planned to be subsequently provided to the public at the selected Living Lab City. Therefore, it is important to determine a spatial area and operation section that enables safe and stable automated driving, depending on the purpose and characteristics of the target service. In this study, the static Operational Design Domain(ODD) elements for Level 4 automated driving services were reclassified by reviewing previously published papers and related literature surveys and investigating field data. Spatial analysis techniques were used to consider the reclassified ODD elements for level 4 in the real area of level 3 automated driving services because it is important to reflect the spatial factors affecting safety related to real automated driving technologies and services. Consequently, a total of six driving mode changes(disengagement) were derived through spatial information analysis techniques, and the factors affecting the safety of automated driving were crosswalk, traffic light, intersection, bicycle road, pocket lane, caution sign, and median strip. This spatial factor analysis method is expected to be useful for determining special areas for the automated driving service.

• Economic and Environmental Geology
• /
• v.36 no.3
• /
• pp.243-255
• /
• 2003

The mathematical models for GIS-based spatial data integration have been developed for geological applications such as mineral potential mapping or landslide susceptibility analysis. Among various models, the effectiveness of fuzzy logic based integration of multiple sets of geological data is investigated and discussed. Unlike a traditional target-driven fuzzy integration approach, we propose a data-driven approach that is derived from statistical relationships between the integration target and related spatial geological data. The proposed approach consists of four analytical steps; data representation, fuzzy combination, defuzzification and validation. For data representation, the fuzzy membership functions based on the likelihood ratio functions are proposed. To integrate them, the fuzzy inference network is designed that can combine a variety of different fuzzy operators. Defuzzification is carried out to effectively visualize the relative possibility levels from the integrated results. Finally, a validation approach based on the spatial partitioning of integration targets is proposed to quantitatively compare various fuzzy integration maps and obtain a meaningful interpretation with respect to future events. The effectiveness and some suggestions of the schemes proposed here are illustrated by describing a case study for landslide susceptibility analysis. The case study demonstrates that the proposed schemes can effectively identify areas that are susceptible to landslides and ${\gamma}$ operator shows the better prediction power than the results using max and min operators from the validation procedure.

• Journal of the Korea Convergence Society
• /
• v.11 no.10
• /
• pp.9-18
• /
• 2020

The purpose of this study is to suggest a method of predicting seismic vulnerability and safety conditions of each building in a targeted area. The scope of this study includes 'developing a simulation model for precaution activities,' 'testing the validity of the developed model', From the facility point of view, target of this study is a local building system. According to the literature review, the number of earthquake prediction modeling and cases with GIS applied is extremely few and the results are not proficient. This study is conducted as a way to improve the previous researches. Statistic analyses are conducted using 348 domestic and international data. Finally, as a result of the series of statistical analyses, an adequate model is developed using optimization scale method. The ratio of correct expectation is estimated as 87%. In order to apply the developed model to predict the vulnerability of the several chosen local building systems, spatial analysis technique is applied. Gangnam-gu and Jongro-gu are selected as the target areas to represent the characteristics of the old and the new downtown in Seoul. As a result of the analysis, it is discovered that buildings in Gangnam-gu are relatively more dangerous comparing to those of Jongro-gu and Eunpyeong-gu.

• Journal of Korean Society of Rural Planning
• /
• v.28 no.1
• /
• pp.17-26
• /
• 2022

It is necessary to prepare a stable production base in advance for a change in the global grain market, and it is required to prepare comprehensive countermeasures such as securing technical skills and cultivation technology. Therefore, Korea, which relies on imports of major grains other than rice, could be exposed to a food crisis at any time unless the self-sufficiency rate of grains is improved. In order to respond to this new food crisis, it is necessary to find ways to efficiently utilize rice fields to increase the domestic grain self-sufficiency rate. From this point of view, interest and demand for the generalization of farmland that can be used as paddy fields and returned to paddy fields are increasing, and related research is also being continuously performed. In order to select a multipurpose farmland project site, this study extracted farmland containing 10% or more purchased and stockpiled farmland through spatial analysis (buffer, dissolve, intersect, etc.), and finally presented areas subject to multipurpose farmland projects. The target site for the multipurpose farmland project was finally selected by integrating data onto a point-by-point basis so that the current status of farmland purchased and stockpiled, Farm Manager Registration Records, and the Korean Soil Information System data (drainage classes, surface soil texture, field-suitability classification, etc.) can be used in combination. There are 175 areas where the multipurpose farmland is possible. Incheon 2, Gyeongbuk 40, Gangwon 2, Chungbuk 7, Chungnam 48, Jeonbuk 34, Jeonnam 19, Gyeongbuk 15, Gyeongnam 8. Chungcheongnam-do has the most target site for the multipurpose farmland project, and Gangwon-do is the least. It is expected to contribute to new commercialization and business expansion by deriving business areas by identifying the scale of the farmland multipurpose farmland project using Farm Manger Registration Records and spatial data.

• Progress in Medical Physics
• /
• v.7 no.1
• /
• pp.3-7
• /
• 1996

The accuracy in target localization of CT, MR, and digital angiography were investigated for stereotactic radiosurgery. The images using CT and MR were obtained out of geometrical phantom which was designed to produce exact coordinates of several points within a 0.lmm error range. The slice interval was 3mm and FOV was 35cm for CT and 28cm for MR. These images were transferred to treatment planning computer using TCP/IP in forms of GE format. Measured 3-D coordinates of these images from planning computer were compared to known values by geometrical phantom. Anterior-posterior and lateral films were taken by digital angiography for measurement of spatial accuracy. Target localization errors were 1.2${\pm}$0.5mm with CT images, 1.7${\pm}$0.4mm with MR-coronal images, and 2.1${\pm}$0.7mm with MR-sagittal images. But, in case of MR-axial images, the target localization error was 4.7${\pm}$0.9mm. Finally, the target localization error of digital angiography was 0.9${\pm}$0.4mm. The accuracy of diagnostic machines such as CT, MR, and angiography depended on their resolutions and distortions. The target localization error mainly depended on the resolution due to slice interval with CT and the image distortion as well as the resolution with MR However, in case of digital angiography, the target localization error was closely related to the distortion of fiducial markers. The results of our study should be considered when PTV (Planning Target Volume) was determined.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.38 no.6
• /
• pp.511-519
• /
• 2020

For camera calibration, a checkerboard is generally used to determine the principal point, focal length, and lens distortions. The checkerboard has a planar and three-dimensional shape, and camera calibration parameters are affected by the size of the checkerboard, the placement of the target, and the number of target points. In this study, the accuracies of the types of checkerboards were compared using checkpoints for stereo camera calibration, and the purpose of this study was to propose the best performance checkerboard. The checkerboard with large flat shape showed comparatively high accuracy through comparison with the check points. However, due to the size of the checkerboard, it was inconvenient to move and rotate, and there was a disadvantage in that it was difficult to shoot so that the target points could all appear in the stereo camera. The checkerboard, which was manufactured in a small size in a flat shape, was easy to move and rotate but had the lowest three-dimensional accuracy. The checkerboard with targets with height values had the hassle of having to determine the three-dimensional coordinates of the target points by using observation equipment for camera calibration, but it was small in size, convenient to move and rotate, and showed the highest three-dimensional accuracy.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.39 no.4
• /
• pp.77-84
• /
• 2021

This paper attempted to examine the value of private house garden as a historical garden among local cultural heritages remaining in Chungcheong-do Province. To this end, the following conclusions were drawn through the framework of value analysis in which the contents of Ji Cheng's Yuanye of China, Tachibana Toshitsuna's Sakuteiki in Japan, and HISTORIC GARDENS THE FLORENCE CHARTER 1981 were applied to target sites. First, local cultural heritage belong to unregistered cultural heritage, and a total of 616 local cultural heritages in Chungcheong-do Province were identified, and Cheongju City possesses the largest number of local cultural heritages. Most of the local cultural heritages are distributed in ancient capital or adjacent to it, and five of the local heritages are related to historical garden. Second, the target sites were old houses constructed during the Joseon Dynasty with a long history, and although there were few changes in spatial division, the scale of some gardens and outer yard spaces was reduced due to urban planning, etc. Third, the target site is Sangjihapui(相地合宜) and Inchacheui(因借體宜) in location and space division, so the space is divided according to the surrounding terrain and the landscape is naturally drawn to construct a garden. Fourth, the garden of the target site has a structural value of a garden that is Jeongihapui(精而合宜) and Gyoideukche(巧而得體) as it is subtle and naturally constructed with the garden by grasping the surrounding terrain. Fifth, for the continuous preservation of historical garden, it is necessary to strengthen the already enacted local cultural heritage ordinance, and to establish a documentary project for each spatial component and a plan for climate change.