• Title/Summary/Keyword: scale detection

Search Result 1,197, Processing Time 0.028 seconds

A Study for Introducing a Method of Detecting and Recovering the Shadow Edge from Aerial Photos (항공영상에서 그림자 경계 탐색 및 복원 기법 연구)

  • Jung, Yong-Ju;Jang, Young-Woon;Choi, Yun-Woong;Cho, Gi-Sung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.24 no.4
    • /
    • pp.327-334
    • /
    • 2006
  • The aerial photos need in a simple object such as cartography and ground cover classification and also in a social objects such as the city plan, environment, disaster, transportation etc. However, the shadow, which includes when taking the aerial photos, makes a trouble to interpret the ground information, and also users, who need the photos in their field tasks, have a restriction. Generally the shadow occurs by the building and surface topography, and the detail cause is by changing of the illumination in an area. For removing the shadow this study uses the single image and processes the image without the source of image and taking situation. Also, applying the entropy minimization method it generates the 1-D gray-scale invariant image for creating the shadow edge mask and using the Canny edge detection creates the shadow edge mask, and finally by filtering in Fourier frequency domain creates the intrinsic image which recovers the 3-D color information and removes the shadow.

3D Building Reconstruction and Visualization by Clustering Airborne LiDAR Data and Roof Shape Analysis

  • Lee, Dong-Cheon;Jung, Hyung-Sup;Yom, Jae-Hong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.25 no.6_1
    • /
    • pp.507-516
    • /
    • 2007
  • Segmentation and organization of the LiDAR (Light Detection and Ranging) data of the Earth's surface are difficult tasks because the captured LiDAR data are composed of irregularly distributed point clouds with lack of semantic information. The reason for this difficulty in processing LiDAR data is that the data provide huge amount of the spatial coordinates without topological and/or relational information among the points. This study introduces LiDAR data segmentation technique by utilizing histograms of the LiDAR height image data and analyzing roof shape for 3D reconstruction and visualization of the buildings. One of the advantages in utilizing LiDAR height image data is no registration required because the LiDAR data are geo-referenced and ortho-projected data. In consequence, measurements on the image provide absolute reference coordinates. The LiDAR image allows measurement of the initial building boundaries to estimate locations of the side walls and to form the planar surfaces which represent approximate building footprints. LiDAR points close to each side wall were grouped together then the least-square planar surface fitting with the segmented point clouds was performed to determine precise location of each wall of an building. Finally, roof shape analysis was performed by accumulated slopes along the profiles of the roof top. However, simulated LiDAR data were used for analyzing roof shape because buildings with various shapes of the roof do not exist in the test area. The proposed approach has been tested on the heavily built-up urban residential area. 3D digital vector map produced by digitizing complied aerial photographs was used to evaluate accuracy of the results. Experimental results show efficiency of the proposed methodology for 3D building reconstruction and large scale digital mapping especially for the urban area.

Automatic Photovoltaic Panel Area Extraction from UAV Thermal Infrared Images

  • Kim, Dusik;Youn, Junhee;Kim, Changyoon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.34 no.6
    • /
    • pp.559-568
    • /
    • 2016
  • For the economic management of photovoltaic power plants, it is necessary to regularly monitor the panels within the plants to detect malfunctions. Thermal infrared image cameras are generally used for monitoring, since malfunctioning panels emit higher temperatures compared to those that are functioning. Recently, technologies that observe photovoltaic arrays by mounting thermal infrared cameras on UAVs (Unmanned Aerial Vehicle) are being developed for the efficient monitoring of large-scale photovoltaic power plants. However, the technologies developed until now have had the shortcomings of having to analyze the images manually to detect malfunctioning panels, which is time-consuming. In this paper, we propose an automatic photovoltaic panel area extraction algorithm for thermal infrared images acquired via a UAV. In the thermal infrared images, panel boundaries are presented as obvious linear features, and the panels are regularly arranged. Therefore, we exaggerate the linear features with a vertical and horizontal filtering algorithm, and apply a modified hierarchical histogram clustering method to extract candidates of panel boundaries. Among the candidates, initial panel areas are extracted by exclusion editing with the results of the photovoltaic array area detection. In this step, thresholding and image morphological algorithms are applied. Finally, panel areas are refined with the geometry of the surrounding panels. The accuracy of the results is evaluated quantitatively by manually digitized data, and a mean completeness of 95.0%, a mean correctness of 96.9%, and mean quality of 92.1 percent are obtained with the proposed algorithm.

Development of leakage test facility for leak signal characteristic analysis in water pipeline (상수도관로 누수신호의 특성 분석을 위한 누수 실험시설 개발)

  • Park, Sanghyuk;Kwak, Philljae;Lee, Hyundong;Choi, Changho
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.31 no.5
    • /
    • pp.459-469
    • /
    • 2017
  • A real scale leakage test facility was developed to study the leak signal characteristics of water supply pipelines, and then leak tests were carried out. The facility was designed to overcome the limited experimental circumstances of domestic water supply pipeline experimental facilities. The length of the pipeline, which was installed as a straight line, is 280m. Six pipes were installed on a 70m interval with different pipe material and diameters that are DCIP(D200, D150, D100, D80), PE(D75) and PVC(D75).The intensity of the leakage is adjusted by changing the size of the leak hole and the opening rate of ball valve. Various pressure conditions were simulated using a pressure reducing valve.To minimize external noise sources which, deteriorate the quality of measured leak signal, the facility was built at a quiet area, where traffic and water consumption by customers is relatively rare. In addition, the usage of electric equipment was minimized to block out noise and the facility was operated using manual mode. From the experimental results of measured leakage signal at the facility, it was found that the signal intensity weakened and the signal of high frequency band attenuated as the distance from the water leakage point increased.

A Comparative Study of Serologic Methods for Detection of Mumps Antibody in Korean Children (한국 소아의 Mumps 바이러스 항체보유에 관한 혈청학적 진단방법의 비교)

  • Park, Hae-Kyung
    • The Journal of the Korean Society for Microbiology
    • /
    • v.21 no.4
    • /
    • pp.473-480
    • /
    • 1986
  • Mumps is an extremly common infectious disease affecting predominantly young children hut it is not a severe disease in terms of mortality. One hundred and two sera from infants of 3 different groups which are vaccinated, unvaccinated and unknown were detected to mumps antibody. The tests used were Complement Fixation(CF) test, Single Radial Hemolysis(SRH) test, Hemagglutination Inhibition(HI) test, Enzyme Linked Immunosorbent Immunoglobulin G(ELISA IgG) test, Enzyme Linked Immunosorbent Immunoglobulin M(ELISA IgM) test. 1. The rate of positivity for mumps antibody in 102 sera wera 89.16%(74/83) by Hl test, 68.83%(53/77) by ELISA IgG test, 64.58%(62/96) by SRH test, 63.24%(43/68) by ELISA IgM test and 50.00%(49/98) by CF test. 2. The rate of positivity by 5 tests for 55 sera turned out to be very similar with above results respectively. 3. The correlation coefficients(r) between ELISA IgG test ant H1 test, ELISA IgG test and ELISA IgM test were 0.34(P<0.0l) and 0.31(P<0.02), respectively. 4. The percentage of apparently natural infection of mumps seemed to be 65.15%(43/66) in infants. 5. Seroconversion rate of mumps by vaccination were 90.91%(10/11). 6. Among the 53 infants who were tested with ELISA IgG 15 were below 15 months age of(28.30%) and this percentage may be taken as a suggestion that mumps vaccination should be given earlier than present practice. 7. ELISA IgG test was found very sensitive and recommendable method for large scale screening for the presence of antibody to mumps.

  • PDF

Application of MODIS Satellite Observation Data for Air Quality Forecast (MODIS 인공위성 관측 자료를 이용한 대기질 예측 응용)

  • Lee, Kwon-Ho;Lee, Dong-Ha;Kim, Young-Joon
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.22 no.6
    • /
    • pp.851-862
    • /
    • 2006
  • Satellites have been valuable tool for global/regional scale atmospheric environment monitoring as well as emission source detection. In this study, we present the results of application of satellite remote sensing data for air quality forecast in Seoul metropolitan area. AOT (Aerosol Optical Thickness) data from TERRA/MODIS (Moderate Resolution Imaging Spectre-radiometer) satellite were compared to ground based $PM_{10}$ mass concentrations, and used to estimate the possibility of the aerosol forecasting in Seoul metropolitan area. Although correlation coefficient (${\sim}0.37$) between MODIS AOT products and surface $PM_{10}$ concentration data was relatively low, there was good correlation between MODIS AOT and surface PM concentration under certain atmospheric conditions, which supports the feasibility of using the high-resolution MODIS AOT for air quality forecasting. The MODIS AOT data with trajectory forecasts also can provide information on aerosol concentration trend. The success rate of the 24 hour aerosol concentration trend forecast result was about 75% in this study. Finally, application of satellite remote sensing data with ground-based air quality observations could provide promising results for air quality monitoring and more exact trend forecast methodology by high resolution satellite data and verification with long term measurement dataset.

Detection of Candidate Areas for Automatic Identification of Scirtothrips Dorsalis (볼록총채벌레 자동판정을 위한 후보영역 검출)

  • Moon, Chang Bae;Kim, Byeong Man;Yi, Jong Yeol;Hyun, Jae Wook;Yi, Pyoung Ho
    • Journal of Korea Society of Industrial Information Systems
    • /
    • v.17 no.6
    • /
    • pp.51-58
    • /
    • 2012
  • Scirtothrips Dorsalis (Thysanoptera: Thripidae) recently has been recognized as a major source of the pest damage in the citrus fruit orchards. So its arrival has been predicted periodically but it is difficult to identify adults of the pest with the naked eyes because of their size smaller than the 0.8mm. In this paper, we propose a method to detect candidate areas for automatic identification of Scirtothrips Dorsalis on forecasting traps. The proposed method uses a histogram-based template matching where the composite image synthesized with the gray-scale image and the gradient image is used. In our experiments, images are acquired by the optical microscopy with 50 magnifications. To show the usefulness of the proposed method, it is compared with the method we previously suggested. Also, the performances when the proposed method is applied to noise-reduced images and gradient images are examined. The experimental results show that the proposed method is approximately 14.42% better than our previous method, 41.63% higher than the case that the noise-reduced image is used, and 21.17% higher than the case that the gradient image is used.

A Bio-fluidic Device for Adaptive Sample Pretreatment and Its Application to Measurements of Escherichia coli Concentrations

  • Choi Won-Jae;Park Je-Kyun
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.11 no.1
    • /
    • pp.54-60
    • /
    • 2006
  • In this paper, we describe a bio-fluidic device for adaptive sample pretreatment, in order to optimize the conditions under which absorbance assays can be conducted. This device can be successfully applied to the measurement of Escherichia coli (E. coli) concentrations using adaptive dilution, with which the dilution ratio can be adjusted during the dilution. Although many attempts have been previously made to miniaturize complex biochemical analyses at the chip scale, very few sample pretreatment processes have actually been miniaturized or automated at this point. Due to the lack of currently available on-chip pretreatments, analytical instruments tend to suffer from a limited range of analysis. This occasionally hinders the direct and quantitative analysis of specific analyses obtained from real samples. In order to overcome these issues, we exploit two novel strategies: dilution with a programmable ratio, and to-and-fro mixing. The bio-fluidic device consists of a rectangular chamber constructed of poly(dimethylsiloxane) (PDMS). This chamber has four openings, an inlet, an outlet, an air control, and an air vent. Each of the dilution cycles is comprised of four steps: detection, liquid drain, buffer injection, and to-and-fro mixing. When using adaptive sample pretreatment, the range in which E. coli concentrations can be measured is broadened, to an optical density (O.D.) range of $0.3{\sim}30$. This device may prove useful in the on-line monitoring of cell concentrations, in both fermenter and aqueous environments.

Identification of 1,531 cSNPs from Full-length Enriched cDNA Libraries of the Korean Native Pig Using in Silico Analysis

  • Oh, Youn-Shin;Nguyen, Dinh Truong;Park, Kwang-Ha;Dirisala, Vijaya R.;Choi, Ho-Jun;Park, Chan-Kyu
    • Genomics & Informatics
    • /
    • v.7 no.2
    • /
    • pp.65-84
    • /
    • 2009
  • Sequences from the clones of full-length enriched cDNA libraries serve as valuable resources for functional genomics related studies, genome annotation and SNP discovery. We analyzed 7,392 high-quality chromatograms (Phred value ${\geq}$30) obtained from sequencing the 5' ends of clones derived from full-length enriched cDNA libraries of Korean native pigs including brainstem, liver, cerebellum, neocortex and spleen libraries. In addition, 50,000 EST sequence trace files obtained from GenBank were combined with our sequences to identify cSNPs in silico. The process generated 11,324 contigs, of which 2,895 contigs contained at least one SNP and among them 610 contigs had a minimum of one sequence from Korean native pigs. Of 610 contigs, we randomly selected 262 contigs and performed in silico analysis for the identification of cSNPs. From the results, we identified 1,531 putative coding single nucleotide polymorphisms (cSNPs) and the SNP detection frequency was one SNP per 465 bp. A large-scale sequencing result of clones from full-length enriched cDNA libraries and identified cSNPs will serve as a useful resource to functional genomics related projects such as a pig HapMap project in the near future.

Electrical Property of Immobilized SWNTs Bundle as Bridge between Electrodes in Nanobiosensor Depending on Solvent Characteristics (시료용액의 특성에 따른 고정화된 단일벽 탄소나노튜브의 전기적 거동)

  • Lee, Jinyoung;Cho, Jaehoon;Park, Chulhwan
    • Korean Chemical Engineering Research
    • /
    • v.55 no.1
    • /
    • pp.115-120
    • /
    • 2017
  • In recent, it is worldwide issued that nanoscale science and technology as a solution have supported to increase the sensing performance in carbon nanotube based biosensor system. Containing material chemistry in various nanostructures has formed their high potentials for stabilizing and activating biocatalyst as a bioreceptor for medical, food contaminants, and environmental detections using electrode modification technologies. Especially, the large surface area provides the attachment of biocatalysts increasing the biocatalyst loading. Therefore, nano-scale engineering of the biocatalysts have been suggested to be the next stage advancement of biosensors. Here, we would like to study the electrical mechanism depending on the exposure methods (soaking or dropping) to the sample solution to the assembled carbon nanotubes (CNTs) on the gold electrodes of biosensor for a simple and highly sensitive detection. We performed various experiments using polar and non-polar solutions as sampling tests and identified electrical response of assembled CNTs in those solutions.