• Title/Summary/Keyword: Detection techniques

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Automated Geometric Correction of Geostationary Weather Satellite Images (정지궤도 기상위성의 자동기하보정)

  • Kim, Hyun-Suk;Lee, Tae-Yoon;Hur, Dong-Seok;Rhee, Soo-Ahm;Kim, Tae-Jung
    • Korean Journal of Remote Sensing
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    • v.23 no.4
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    • pp.297-309
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    • 2007
  • The first Korean geostationary weather satellite, Communications, Oceanography and Meteorology Satellite (COMS) will be launched in 2008. The ground station for COMS needs to perform geometric correction to improve accuracy of satellite image data and to broadcast geometrically corrected images to users within 30 minutes after image acquisition. For such a requirement, we developed automated and fast geometric correction techniques. For this, we generated control points automatically by matching images against coastline data and by applying a robust estimation called RANSAC. We used GSHHS (Global Self-consistent Hierarchical High-resolution Shoreline) shoreline database to construct 211 landmark chips. We detected clouds within the images and applied matching to cloud-free sub images. When matching visible channels, we selected sub images located in day-time. We tested the algorithm with GOES-9 images. Control points were generated by matching channel 1 and channel 2 images of GOES against the 211 landmark chips. The RANSAC correctly removed outliers from being selected as control points. The accuracy of sensor models established using the automated control points were in the range of $1{\sim}2$ pixels. Geometric correction was performed and the performance was visually inspected by projecting coastline onto the geometrically corrected images. The total processing time for matching, RANSAC and geometric correction was around 4 minutes.

Detection and Analysis of Three-dimensional Changes in Haeundae Marine and Beach Topography using RS and GIS Technology (RS.GIS 기법을 활용한 해운대 해저.해빈지형의 3차원 입체변화 탐지 및 분석)

  • Hong, Hyun-Jung;Choi, Chul-Uong;Han, Kyung-Soo;Jeon, Seong-Woo
    • Korean Journal of Remote Sensing
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    • v.22 no.4
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    • pp.243-253
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    • 2006
  • As the ocean and beaches have suffered from the losses of sand, it is necessary to monitor the zones that are prone to erosion continuously with the object of the long-term management. However, each ward offices are busy trying to supply sand without analyzing the marine and beach topographic changes. Therefore a long term effect of erosion has not been shown. In this study, we proposed methods to collect accurate spatial data of the oceans and beaches through sounding and GPS surveys, and detected and analyzed topographic changes quantitatively and qualitatively, by using an integrated RS and GIS techniques. The result of this study revealed that the marine topography has been eroded for 25 years, because of the straight construction of the river and the vast development of urban features, in addition with change of the mean depth 0.40 m, the water surface area 11,028 $m^2$, and submarine volume 2,207,884 $m^3$. The beach topography has accreted for 5 years and the change of the mean elevation is 0.27m, the area 6,501 $m^2$, and volume 25,667 $m^3$, because of the installation of geogrids and the seasonal effect. We conducted monitoring works on the topographic survey of the ocean and beaches and analyzed the present condition of the coastal erosions. Therefore, it is estimated that necessary information on the supply of sand, the safe marine leisure and the management of bating place could be provided.

Fire Severity Mapping Using a Single Post-Fire Landsat 7 ETM+ Imagery (단일 시기의 Landsat 7 ETM+ 영상을 이용한 산불피해지도 작성)

  • 원강영;임정호
    • Korean Journal of Remote Sensing
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    • v.17 no.1
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    • pp.85-97
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    • 2001
  • The KT(Kauth-Thomas) and IHS(Intensity-Hue-Saturation) transformation techniques were introduced and compared to investigate fire-scarred areas with single post-fire Landsat 7 ETM+ image. This study consists of two parts. First, using only geometrically corrected imagery, it was examined whether or not the different level of fire-damaged areas could be detected by simple slicing method within the image enhanced by the IHS transform. As a result, since the spectral distribution of each class on each IHS component was overlaid, the simple slicing method did not seem appropriate for the delineation of the areas of the different level of fire severity. Second, the image rectified by both radiometrically and topographically was enhanced by the KT transformation and the IHS transformation, respectively. Then, the images were classified by the maximum likelihood method. The cross-validation was performed for the compensation of relatively small set of ground truth data. The results showed that KT transformation produced better accuracy than IHS transformation. In addition, the KT feature spaces and the spectral distribution of IHS components were analyzed on the graph. This study has shown that, as for the detection of the different level of fire severity, the KT transformation reflects the ground physical conditions better than the IHS transformation.

Estimation of Individual Tree and Tree Height using Color Aerial Photograph and LiDAR Data (컬러항공사진과 LiDAR 데이터를 이용한 수목 개체 및 수고 추정)

  • Chang, An-Jin;Kim, Yong-Il;Lee, Byung-Kil;Yu, Ki-Yun
    • Korean Journal of Remote Sensing
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    • v.22 no.6
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    • pp.543-551
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    • 2006
  • Recently efforts to extract information about forests by using remote sensing techniques for efficient forest management have progressed actively. In terms of extraction of tree information using single remote sensing data, however, the accuracy of tree recognition and the quantity of extracted information is limited. The objective of this study is to carry out tree modeling in domestic environment applying the latest core technique for tree modeling using color aerial photographs and LiDAR data and to estimate the result of tree modeling. A small-scale coniferous forest was investigated in Daejeon. It was 0.77 that the $R^2$ of accuracy test of tree numbers that estimated with color aerial photography and LiDAR data. In terms of tree height, there was no difference between the estimated value and the field measurements in the case of the group accuracy test of the recently unchanged area. Moreover $R^2$ was 0.83 in the case of the individual accuracy test.

Evaluation of Grid-Based ROI Extraction Method Using a Seamless Digital Map (연속수치지형도를 활용한 격자기준 관심 지역 추출기법의 평가)

  • Jeong, Jong-Chul
    • Journal of Cadastre & Land InformatiX
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    • v.49 no.1
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    • pp.103-112
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    • 2019
  • Extraction of region of interest for satellite image classification is one of the important techniques for efficient management of the national land space. However, recent studies on satellite image classification often depend on the information of the selected image in selecting the region of interest. This study propose an effective method of selecting the area of interest using the continuous digital topographic map constructed from high resolution images. The spatial information used in this research is based on the digital topographic map from 2013 to 2017 provided by the National Geographical Information Institute and the 2015 Sejong City land cover map provided by the Ministry of Environment. To verify the accuracy of the extracted area of interest, KOMPSAT-3A satellite images were used which taken on October 28, 2018 and July 7, 2018. The baseline samples for 2015 were extracted using the unchanged area of the continuous digital topographic map for 2013-2015 and the land cover map for 2015, and also extracted the baseline samples in 2018 using the unchanged area of the continuous digital topographic map for 2015-2017 and the land cover map for 2015. The redundant areas that occurred when merging continuous digital topographic maps and land cover maps were removed to prevent confusion of data. Finally, the checkpoints are generated within the region of interest, and the accuracy of the region of interest extracted from the K3A satellite images and the error matrix in 2015 and 2018 is shown, and the accuracy is approximately 93% and 72%, respectively. The accuracy of the region of interest can be used as a region of interest, and the misclassified region can be used as a reference for change detection.

Current status on the modification of the scope for GMO regulation on the gene edited plants with no remnants of inserted foreign DNA fragments (외래 DNA단편이 잔존하지 않는 유전자교정식물에 대한 GMO규제 범위의 제외에 관한 국제 동향)

  • Lee, Shin-Woo
    • Journal of Plant Biotechnology
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    • v.46 no.3
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    • pp.137-142
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    • 2019
  • Gene edited crops can be classified as SDN-1, SDN-2 and SDN-3 group depending on their mutation's range and the usage of donor DNA. The SDN-1 and SDN-2 crops, in particular, could be developed as 100% transgene-free, which do not contain any DNA fragment of the vector or guide RNA used for gene editing such as CRISPR Cas9 system. Therefore, there are no scientific methods available for the detection of these crops and differentiation with the one produced by conventional cross breeding techniques. Additionally, it would be impossible to properly implement the existing GMO regulation law, in particular, the national legislation for "GMO labelling". In this regard, Australia has announced that SDN-1 crops will not be subjected to the existing GMO regulation. Furthermore, Argentina and Brazil have established a new policy that GE crops with no transgene (100% transgene-free crops) should be exempted from the scope of the GMO. In addition, Japan has also announced that "an organism that has no remnants of inserted nucleic acid processed extracellularly is not subjected to the Cartagena Act". It means that SDN-2 crops can also be exempted from the scope of GMO. In this trend, in South Korea, I suggested that gene edited crops with no remnants of inserted foreign DNA fragments should be excluded from the existing GMO regulation. Thus, I expect that diverse elite crop lines should be developed by using advanced gene editing technologies

Analysis of Access Authorization Conflict for Partial Information Hiding of RDF Web Document (RDF 웹 문서의 부분적인 정보 은닉과 관련한 접근 권한 충돌 문제의 분석)

  • Kim, Jae-Hoon;Park, Seog
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.18 no.2
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    • pp.49-63
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    • 2008
  • RDF is the base ontology model which is used in Semantic Web defined by W3C. OWL expands the RDF base model by providing various vocabularies for defining much more ontology relationships. Recently Jain and Farkas have suggested an RDF access control model based on RDF triple. Their research point is to introduce an authorization conflict problem by RDF inference which must be considered in RDF ontology data. Due to the problem, we cannot adopt XML access control model for RDF, although RDF is represented by XML. However, Jain and Farkas did not define the authorization propagation over the RDF upper/lower ontology concepts when an RDF authorization is specified. The reason why the authorization specification should be defined clearly is that finally, the authorizatin conflict is the problem between the authorization propagation in specifying an authorization and the authorization propagation in inferencing authorizations. In this article, first we define an RDF access authorization specification based on RDF triple in detail. Next, based on the definition, we analyze the authoriztion conflict problem by RDF inference in detail. Next, we briefly introduce a method which can quickly find an authorization conflict by using graph labeling techniques. This method is especially related with the subsumption relationship based inference. Finally, we present a comparison analysis with Jain and Farkas' study, and some experimental results showing the efficiency of the suggested conflict detection method.

A Study on Detection Technique of Anomaly Signal for Financial Loan Fraud Based on Social Network Analysis (소셜 네트워크 분석 기반의 금융회사 불법대출 이상징후 탐지기법에 관한 연구)

  • Wi, Choong-Ki;Kim, Hyoung-Joong;Lee, Sang-Jin
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.4
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    • pp.851-868
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    • 2012
  • After the financial crisis in 2008, the financial market still seems to be unstable with expanding the insolvency of the financial companies' real estate project financing loan in the aftermath of the lasted real estate recession. Especially after the illegal actions of people's financial institutions disclosed, while increased the anxiety of economic subjects about financial markets and weighted in the confusion of financial markets, the potential risk for the overall national economy is increasing. Thus as economic recession prolongs, the people's financial institutions having a weak profit structure and financing ability commit illegal acts in a variety of ways in order to conceal insolvent assets. Especially it is hard to find the loans of shareholder and the same borrower sharing credit risk in advance because most of them usually use a third-party's name bank account. Therefore, in order to effectively detect the fraud under other's name, it is necessary to analyze by clustering the borrowers high-related to a particular borrower through an analysis of association between the whole borrowers. In this paper, we introduce Analysis Techniques for detecting financial loan frauds in advance through an analysis of association between the whole borrowers by extending SNA(social network analysis) which is being studied by focused on sociology recently to the forensic accounting field of the financial frauds. Also this technique introduced in this pager will be very useful to regulatory authorities or law enforcement agencies at the field inspection or investigation.

A Development of Welding Information Management and Defect Inspection Platform based on Artificial Intelligent for Shipbuilding and Maritime Industry (인공지능 기반 조선해양 용접 품질 정보 관리 및 결함 검사 플랫폼 개발)

  • Hwang, Hun-Gyu;Kim, Bae-Sung;Woo, Yun-Tae;Yoon, Young-Wook;Shin, Sung-chul;Oh, Sang-jin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.2
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    • pp.193-201
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    • 2021
  • The welding has a high proportion of the production and drying of ships or offshore plants. Non-destructive testing is carried out to verify the quality of welds in Korea, radiography test (RT) is mainly used. Currently, most shipyards adopt analog-type techniques to print the films through the shoot of welding parts. Therefore, the time required from radiography test to pass or fail judgment is long and complex, and is being manually carried out by qualified inspectors. To improve this problem, this paper covers a platform for scanning and digitalizing RT films occurring in shipyards with high resolution, accumulating them in management servers, and applying artificial intelligence (AI) technology to detect welding defects. To do this, we describe the process of designing and developing RT film scanning equipment, welding inspection information integrated management platform, fault reading algorithms, visualization software, and testing and verification of each developed element in conjunction.

Road Extraction from Images Using Semantic Segmentation Algorithm (영상 기반 Semantic Segmentation 알고리즘을 이용한 도로 추출)

  • Oh, Haeng Yeol;Jeon, Seung Bae;Kim, Geon;Jeong, Myeong-Hun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.3
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    • pp.239-247
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    • 2022
  • Cities are becoming more complex due to rapid industrialization and population growth in modern times. In particular, urban areas are rapidly changing due to housing site development, reconstruction, and demolition. Thus accurate road information is necessary for various purposes, such as High Definition Map for autonomous car driving. In the case of the Republic of Korea, accurate spatial information can be generated by making a map through the existing map production process. However, targeting a large area is limited due to time and money. Road, one of the map elements, is a hub and essential means of transportation that provides many different resources for human civilization. Therefore, it is essential to update road information accurately and quickly. This study uses Semantic Segmentation algorithms Such as LinkNet, D-LinkNet, and NL-LinkNet to extract roads from drone images and then apply hyperparameter optimization to models with the highest performance. As a result, the LinkNet model using pre-trained ResNet-34 as the encoder achieved 85.125 mIoU. Subsequent studies should focus on comparing the results of this study with those of studies using state-of-the-art object detection algorithms or semi-supervised learning-based Semantic Segmentation techniques. The results of this study can be applied to improve the speed of the existing map update process.