• Title/Summary/Keyword: detecting change points

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An Analysis of the Effect of Climate Change on Flow in Nakdong River Basin Using Watershed-Based Model (유역기반 모형을 이용한 기후변화에 따른 낙동강 유역의 하천유량 영향 분석)

  • Shon, Tae-Seok;Lee, Sang-Do;Kim, Sang-Dan;Shin, Hyun-Suk
    • Journal of Korea Water Resources Association
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    • v.43 no.10
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    • pp.865-881
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    • 2010
  • To evaluate influence of the future climate change on water environment, it is necessary to use a rainfall-runoff model, or a basin model allowing us to simultaneously simulate water quality factors such as sediment and nutrient material. Thus, SWAT is selected as a watershed-based model and Nakdong river basin is chosen as a target basin for this study. To apply climate change scenarios as input data to SWAT, Australian model (CSIRO: Mk3.0, CSMK) and Canadian models (CCCma: CGCM3-T47, CT47) of GCMs are used. Each GCMs which have A2, B1, and A1B scenarios effectively represent the climate characteristics of the Korean peninsula. For detecting climate change in Nakdong river basin, precipitation and temperature, increasing rate of these were analyzed in each scenarios. By simulation results, flow and increasing rate of these were analyzed at particular points which are important in the object basin. Flow and variation of flow in the scenarios for present and future climate changes were compared and analyzed by years, seasons, divided into mid terms. In most of the points temperature and flow rate are increased, because climate change is expected to have a significant effect on rising water temperature and flow rate of river and lake, further on the basis of this study result should set enhancing up water control project of hydraulic structures caused by increasing outer discharge of the Nakdong River Basin due to climate change.

Real-Time Lane Detection Based on Inverse Perspective Transform and Search Range Prediction (역 원근 변환과 검색 영역 예측에 의한 실시간 차선 인식)

  • Jeong, Seung-Gweon;Kim, In-Soo;Kim, Sung-Han;Lee, Dong-Hwoal;Yun, Kang-Sup;Lee, Man-Hyung
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.3
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    • pp.68-74
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    • 2001
  • A lane detection based on a road model or feature all needs correct acquirement of information on the lane in an image. It is inefficient to implement a lane detection algorithm through the full range of an image when it is applied to a real road in real time because of the calculating time. This paper defines two (other proper terms including"modes") for detecting lanes on a road. First is searching mode that is searching the lane without any prior information of a road. Second is recognition mode, which is able to reduce the size and change the position of a searching range by predicting the position of a lane through the acquired information in a previous frame. It allows to extract accurately and efficiently the edge candidate points of a lane without any unnecessary searching. By means of inverse perspective transform which removes the perspective effect on the edge candidate points, we transform the edge candidate information in the Image Coordinate System(ICS) into the plan-view image in the World Coordinate System(WCS). We define a linear approximation filter and remove faulty edge candidate points by using it. This paper aims at approximating more correctly the lane of an actual road by applying the least-mean square method with the fault-removed edge information for curve fitting.e fitting.

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Real-Time Lane Detection Based on Inverse Perspective Transform and Search Range Prediction (역원근 변환과 검색 영역 예측에 의한 실시간 차선 인식)

  • Kim, S.H.;Lee, D.H.;Lee, M.H.;Be, J.I.
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.2843-2845
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    • 2000
  • A lane detection based on a road model or feature all need correct acquirement of information on the lane in a image, It is inefficient to implement a lane detection algorithm through the full range of a image when being applied to a real road in real time because of the calculating time. This paper defines two searching range of detecting lane in a road, First is searching mode that is searching the lane without any prior information of a road, Second is recognition mode, which is able to reduce the size and change the position of a searching range by predicting the position of a lane through the acquired information in a previous frame. It is allow to extract accurately and efficiently the edge candidates points of a lane as not conducting an unnecessary searching. By means of removing the perspective effect of the edge candidate points which are acquired by using the inverse perspective transformation, we transform the edge candidate information in the Image Coordinate System(ICS) into the plane-view image in the World Coordinate System(WCS). We define linear approximation filter and remove the fault edge candidate points by using it This paper aims to approximate more correctly the lane of an actual road by applying the least-mean square method with the fault-removed edge information for curve fitting.

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Detecting Malicious Scripts in Web Contents through Remote Code Verification (원격코드검증을 통한 웹컨텐츠의 악성스크립트 탐지)

  • Choi, Jae-Yeong;Kim, Sung-Ki;Lee, Hyuk-Jun;Min, Byoung-Joon
    • The KIPS Transactions:PartC
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    • v.19C no.1
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    • pp.47-54
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    • 2012
  • Sharing cross-site resources has been adopted by many recent websites in the forms of service-mashup and social network services. In this change, exploitation of the new vulnerabilities increases, which includes inserting malicious codes into the interaction points between clients and services instead of attacking the websites directly. In this paper, we present a system model to identify malicious script codes in the web contents by means of a remote verification while the web contents downloaded from multiple trusted origins are executed in a client's browser space. Our system classifies verification items according to the origin of request based on the information on the service code implementation and stores the verification results into three databases composed of white, gray, and black lists. Through the experimental evaluations, we have confirmed that our system provides clients with increased security by effectively detecting malicious scripts in the mashup web environment.

Speaker Segmentation System Using Eigenvoice-based Speaker Weight Distance Method (Eigenvoice 기반 화자가중치 거리측정 방식을 이용한 화자 분할 시스템)

  • Choi, Mu-Yeol;Kim, Hyung-Soon
    • The Journal of the Acoustical Society of Korea
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    • v.31 no.4
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    • pp.266-272
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    • 2012
  • Speaker segmentation is a process of automatically detecting the speaker boundary points in the audio data. Speaker segmentation methods are divided into two categories depending on whether they use a prior knowledge or not: One is the model-based segmentation and the other is the metric-based segmentation. In this paper, we introduce the eigenvoice-based speaker weight distance method and compare it with the representative metric-based methods. Also, we employ and compare the Euclidean and cosine similarity functions to calculate the distance between speaker weight vectors. And we verify that the speaker weight distance method is computationally very efficient compared with the method directly using the distance between the speaker adapted models constructed by the eigenvoice technique.

Development of a CAD-based Utility for Topological Identification and Rasterized Mapping from Polygonal Vector Data (CAD 수단을 이용한 벡터형 공간자료의 위상 검출과 격자도면화를 위한 유틸리티 개발)

  • 조동범;임재현
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.4
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    • pp.137-142
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    • 1999
  • The purpose of this study is to develope a CAD-based tool for rasterization of polygonal vector map in AutoCAD. To identity the layer property of polygonal entity with user-defined coordinates as topology, algorithm in processing entity data of selection set that intersected with scan line was used, and the layers were extracted sequentially by sorted intersecting points in data-list. In addition to the functions for querying and modifying topology, two options for mapping were set up to construct plan projection type and to change meshes' properties in existing DTM data. In case of plan projection type, user-defined cell size of 3DFACE mesh is available for more detailed edge, and topological draping on landform can be executed in case of referring DTM data as an AutoCAD's drawing. The concept of algorithm was simple and clear, but some unexpectable errors were found in detecting intersected coordinates that were AutoCAD's error, not the utility's. Also, the routines to check these errors were included in algorithmic processing. Developed utility named MESHMAP was written in entity data control functions of AutoLISP language and dialog control language(DCL) for the purpose of user-oriented interactive usage. MESHMAP was proved to be more effective in data handling and time comparing with GRIDMAP module in LANDCADD which has similar function.

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Knowledge Based Automated Boundary Detection for Quantifying of Left Ventricular Function in Low Contrast Angiographic Images (저대조 혈관 조영상에서 좌심실 기능의 정량화를 위한 지식 기반의 경계선 자동검출)

  • 전춘기;권용무
    • Journal of Biomedical Engineering Research
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    • v.17 no.1
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    • pp.109-120
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    • 1996
  • Cardiac function is evaluated quantitatively using angiographic images via the analysis of the shape change or the heart wall boundaries. To kin with, boundary defection or ESLV(End Systolic Lert Ventricular) and EDLV(End Diastolic Left Ventricular) is essential for the quantitative analysis of cardiac function. The boundary detection methods proposed in the past were almost semi-automatic. Intervention by a knowledgeable human operator was still required Of con, manual tracing of the boundaries is currently used for subsequent analysis and diagnosis. This method would not cut excessive time, labor, and subjectivity associated with manual intervention by a human operator. EDLV images have noncontiguous and ambiguous edge signal on some boundary regions. In this paper, we propose a new method for automated detection of boundaries in noncontiguous and ambiguous EDLV images. The boundary detection scheme which based on a priori knowledge information is divided into two steps. The first step is to detect the candidate edge points of EDLV using ESLV boundaries. The second step is to correct detected boundaries of EDLV using the LV shape. We developed the algorithm of modifying EDLV boundaries defined adaptive modifier. We experimented the method proposed in this paper and compared our proposed method with the manual method in detecting boundaries of EDLV. In the areas within estimated boundaries of EDLV, the percentage of error was about 1.4%. We verified the useflilness and obtained the satisfying results througll the experiments of the proposed method.

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Health monitoring of pressurized pipelines by finite element method using meta-heuristic algorithms along with error sensitivity assessment

  • Amirmohammad Jahan;Mahdi Mollazadeh;Abolfazl Akbarpour;Mohsen Khatibinia
    • Structural Engineering and Mechanics
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    • v.87 no.3
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    • pp.211-219
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    • 2023
  • The structural health of a pipeline is usually assessed by visual inspection. In addition to the fact that this method is expensive and time consuming, inspection of the whole structure is not possible due to limited access to some points. Therefore, adopting a damage detection method without the mentioned limitations is important in order to increase the safety of the structure. In recent years, vibration-based methods have been used to detect damage. These methods detect structural defects based on the fact that the dynamic responses of the structure will change due to damage existence. Therefore, the location and extent of damage, before and after the damage, are determined. In this study, fuzzy genetic algorithm has been used to monitor the structural health of the pipeline to create a fuzzy automated system and all kinds of possible failure scenarios that can occur for the structure. For this purpose, the results of an experimental model have been used. Its numerical model is generated in ABAQUS software and the results of the analysis are used in the fuzzy genetic algorithm. Results show that the system is more accurate in detecting high-intensity damages, and the use of higher frequency modes helps to increase accuracy. Moreover, the system considers the damage in symmetric regions with the same degree of membership. To deal with the uncertainties, some error values are added, which are observed to be negligible up to 10% of the error.

Building change detection in high spatial resolution images using deep learning and graph model (딥러닝과 그래프 모델을 활용한 고해상도 영상의 건물 변화탐지)

  • Park, Seula;Song, Ahram
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.3
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    • pp.227-237
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    • 2022
  • The most critical factors for detecting changes in very high-resolution satellite images are building positional inconsistencies and relief displacements caused by satellite side-view. To resolve the above problems, additional processing using a digital elevation model and deep learning approach have been proposed. Unfortunately, these approaches are not sufficiently effective in solving these problems. This study proposed a change detection method that considers both positional and topology information of buildings. Mask R-CNN (Region-based Convolutional Neural Network) was trained on a SpaceNet building detection v2 dataset, and the central points of each building were extracted as building nodes. Then, triangulated irregular network graphs were created on building nodes from temporal images. To extract the area, where there is a structural difference between two graphs, a change index reflecting the similarity of the graphs and differences in the location of building nodes was proposed. Finally, newly changed or deleted buildings were detected by comparing the two graphs. Three pairs of test sites were selected to evaluate the proposed method's effectiveness, and the results showed that changed buildings were detected in the case of side-view satellite images with building positional inconsistencies.

Pulse wave Measurement System by analyzing a Moving Pulse Image in the Capillary Tube (모세관 맥동파 영상을 이용한 맥파 측정 시스템)

  • Lee, Woo-Beom;Choi, Chang-Yur;Hong, You-Sik;Lee, Sang-Suk;Nam, Dong-Hyun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.2
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    • pp.145-151
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    • 2012
  • The pulsimeter is a representative device in the oriental medicine, which can analysis a risk factor in a cardiovascular diseases. However, most of the previous methods have the limit by the contacted sate of the brachial pulse and sensor in the measuring time, the inaccuracy of detected pulse, and the difficulty of pulse analysis. Accordingly, we propose the moving pulse image analysis based pulsimeter that can acquire a pulse of patient in real time by analyzing a moving image. then this video is shot the state change of the T.S. occurred by a pulse in capillary. In order to evaluate the performance of the our pulsimeter, we measured a respective detecting-rate about the essential 5 feature-points in the pulse analysis from the detected original pulse. As a result, the proposed method is very successful.