• 제목/요약/키워드: Zone-Based Detection

검색결과 132건 처리시간 0.026초

Investigating the future changes of extreme precipitation indices in Asian regions dominated by south Asian summer monsoon

  • Deegala Durage Danushka Prasadi Deegala;Eun-Sung Chung
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2023년도 학술발표회
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    • pp.174-174
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    • 2023
  • The impact of global warming on the south Asian summer monsoon is of critical importance for the large population of this region. This study aims to investigate the future changes of the precipitation extremes during pre-monsoon and monsoon, across this region in a more organized regional structure. The study area is divided into six major divisions based on the Köppen-Geiger's climate structure and 10 sub-divisions considering the geographical locations. The future changes of extreme precipitation indices are analyzed for each zone separately using five indices from ETCCDI (Expert Team on Climate Change Detection and Indices); R10mm, Rx1day, Rx5day, R95pTOT and PRCPTOT. 10 global climate model (GCM) outputs from the latest CMIP6 under four combinations of SSP-RCP scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) are used. The GCMs are bias corrected using nonparametric quantile transformation based on the smoothing spline method. The future period is divided into near future (2031-2065) and far future (2066-2100) and then the changes are compared based on the historical period (1980-2014). The analysis is carried out separately for pre-monsoon (March, April, May) and monsoon (June, July, August, September). The methodology used to compare the changes is probability distribution functions (PDF). Kernel density estimation is used to plot the PDFs. For this study we did not use a multi-model ensemble output and the changes in each extreme precipitation index are analyzed GCM wise. From the results it can be observed that the performance of the GCMs vary depending on the sub-zone as well as on the precipitation index. Final conclusions are made by removing the poor performing GCMs and by analyzing the overall changes in the PDFs of the remaining GCMs.

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사이버 방어를 위한 적응형 다중계층 보호체제 (Adaptive Multi-Layer Security Approach for Cyber Defense)

  • 이성기;강태인
    • 인터넷정보학회논문지
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    • 제16권5호
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    • pp.1-9
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    • 2015
  • 사이버 공간에서 첨예화, 복잡화되고 있는 공격을 일대일 방식으로 방어하는데 한계가 있으므로 보다 효과적인 방어 방법이 필요하다. 본 고에서는 내외부의 공격에 대해 자산을 체계적 적응적으로 방어할 수 있는 다중계층 보안체제 구축 방안을 제시한다. 방어지역(Defense Zone)을 중심으로 한 다중계층 보안체제의 구조를 고안하고, 사이버 위협분석과 방어기술 자동할당 등 구현에 필요한 기술요소들에 대해 논의한다. 또한, 다중계층 보안체제에 대한 효과와 적용성을 보인다. 향후, 제시된 방안의 구체화를 위해 방어지역에 대한 상세구조설계, 최적 방어기술 자동선택방법, 위협 탐지를 위한 정상상태 모델링 기술 등에 대한 연구가 필요하다.

Detection of High-Risk Human Papillomaviruses in the Prevention of Cervical Cancer in India

  • Baskaran, Krishnan;Kumar, P Kranthi;Karunanithi, Santha;Sethupathy, Subramanian;Thamaraiselvi, B;Swaruparani, S
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권18호
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    • pp.8187-8190
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    • 2016
  • Human papillomaviruses (HPVs) are small, non-enveloped, double-stranded DNA viruses that infect epithelial tissues. Specific genotypes of human papillomavirus are the single most common etiological agents of cervical intraepithelial lesions and cervical cancer. Cervical cancer usually arises at squamous metaplastic epithelium of transformation zone (TZ) of the cervix featuring infection with one or more oncogenic or high-risk HPV (HR-HPV) types. A hospital-based study in a rural set up was carried out to understand the association of HR-HPV with squamous intraepithelial lesions (SILs) and cervical cancer. In the present study, HR-HPV was detected in 65.7% of low-grade squamous intraepithelial lesions (LSILs), 84.6% of high-grade squamous intraepithelial lesions (HSILs) and 94% of cervical cancer as compared to 10.7% of controls. The association of HPV infection with SIL and cervical cancer was analyzed with Chi square test (p<0.001). The significant association found confirmed that detection of HR-HPV is a suitable candidate for early identification of cervical precancerous lesions and in the prevention of cervical cancer in India.

레이저레이더 센서를 이용한 철도 건널목 지장물 검지 알고리즘 개발 (Algorithm Development of Level Crossing Obstacle Detection using Laser Radar Sensor)

  • 김영준;백종현;최규형
    • 전기학회논문지
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    • 제62권12호
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    • pp.1813-1819
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    • 2013
  • Existing level crossing obstacle detecting system was installed using a laser beam. Level crossing obstacle detecting system using a laser beam that has been a problem in relation to safety and maintainability failure according to weather conditions. We proposed laser radar level crossing obstacle detecting system as a way to overcome problem, and we developed an algorithm for this. Level crossing obstacle detecting system using a laser radar sensor algorithm is robust to external environment and a shadow zone does not exist. Sensor part of the laser radar level crossing obstacle detecting system of these is made up by the image processing unit and laser radar sensor, it operations by receiving train entering information from the control unit. In this paper, we proposed a detecting algorithm with calculation of the size of the laser radar sensor. Based on this, we were performance test on the basis of the scenario by making a prototype. In the future, laser radar level crossing obstacle detecting system to ensure the safety and reliability through the field test.

딥러닝 기반의 운전자의 안전/위험 상태 인지 시스템 개발 (Development of Driver's Safety/Danger Status Cognitive Assistance System Based on Deep Learning)

  • 미아오 쉬;이현순;강보영
    • 로봇학회논문지
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    • 제13권1호
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    • pp.38-44
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    • 2018
  • In this paper, we propose Intelligent Driver Assistance System (I-DAS) for driver safety. The proposed system recognizes safety and danger status by analyzing blind spots that the driver cannot see because of a large angle of head movement from the front. Most studies use image pre-processing such as face detection for collecting information about the driver's head movement. This not only increases the computational complexity of the system, but also decreases the accuracy of the recognition because the image processing system dose not use the entire image of the driver's upper body while seated on the driver's seat and when the head moves at a large angle from the front. The proposed system uses a convolutional neural network to replace the face detection system and uses the entire image of the driver's upper body. Therefore, high accuracy can be maintained even when the driver performs head movement at a large angle from the frontal gaze position without image pre-processing. Experimental result shows that the proposed system can accurately recognize the dangerous conditions in the blind zone during operation and performs with 95% accuracy of recognition for five drivers.

자동 임계값 추출 알고리즘과 KOMPSAT-3A를 활용한 무감독 변화탐지의 정확도 평가 (Accuracy Assessment of Unsupervised Change Detection Using Automated Threshold Selection Algorithms and KOMPSAT-3A)

  • 이승민;정종철
    • 대한원격탐사학회지
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    • 제36권5_2호
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    • pp.975-988
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    • 2020
  • 변화탐지는 서로 다른 시점에 촬영된 영상에서 일어난 변화를 관측하는 기술로 위성영상을 활용한 원격탐사 분야에서 중요한 기술이다. 변화탐지 기법 중 하나인 무감독 변화탐지 기법은 단시간 내에 변화지역을 추출할 수 있는 장점을 지니지만, 임계값을 통해 변화된 지역을 이진영상으로 나타내기 때문에 토지피복변화를 파악하기 어렵다는 단점이 있다. 본 연구는 이러한 무감독 변화탐지의 단점을 보완하기 위해 공간정보를 기반으로 생성된 격자 포인트를 이용하여 위성영상의 토지피복변화 및 정확도 평가를 수행하였다. 변화탐지 알고리즘은 Spectral Angle Mapper(SAM)를 사용하였으며, 김제자유무역지역 일대를 촬영한 KOMPSAT-3A(K3A) 위성영상을 대상으로 진행하였다. 변화탐지결과는 자동 임계값 추출 알고리즘들 중 Otsu, Kittler, Kapur, Tsai 방법을 사용하여 이진영상으로 나타냈다. 또한, 변화탐지에 사용된 두 시점의 위성영상은 계절에 의한 식생 변화가 존재하기 때문에 확률밀도함수를 통한 Differenced Normalized Difference Vegetation Index(dNDVI)의 임계값으로 계절적 영향을 받는 지역을 제거하였다. 연구 결과, 자동 임계값 추출 알고리즘 중 Otsu와 Kapur의 정확도가 58.16%로 나타났고, dNDVI를 통해 계절적 영향을 제거하였을 때 85.47%로 정확도가 개선된 결과를 보였다. 본 연구결과를 기반으로 생성된 알고리즘은 무감독 변화탐지를 수행할 때 정확도 평가와 토지피복변화를 정량적으로 파악하여 기존의 단점을 보완할 수 있다고 판단된다.

간접전류제어 기반의 계통연계형 인버터를 위한 단독운전방지 기법 (Anti-islanding Method for Indirect Current Control based Utility Interactive Inverter)

  • 오형민;김영우;최세완
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2011년도 추계학술대회
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    • pp.207-208
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    • 2011
  • 중요부하를 갖는 계통연계 인버터에서 계통이상시 독립운전으로 전환하여 중요부하에 지속적인 전력을 공급하여야 한다. 기존의 제어 방식은 독립운전시 전압제어를 계통연계시 전류제어를 하기 때문에 모드전환시 과도상태가 발생하고 단독운전 검출전에도 부하의 전압과 주파수가 변동하여 중요부하에 심각한 영향을 줄 수 있다. 본 논문에서는 모드 전환시 과도상태를 최소화하면서 단독운전 검출전에도 부하 전압과 주파수가 일정하게 유지하는 간접전류제어 기반의 계통연계 인버터에서 전압 고조파를 주입함으로써 NDZ(Non-Detection Zone)를 갖지 않는 단독운전방지 기법을 제안한다.

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고주파를 이용한 송전선로의 사고 검출 및 판별에 관한 연구 (A Study on the Fault Detection and Discrimination of Transmission Line using Fault-generated high frequency signals)

  • 임병호;김철환;이동준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 C
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    • pp.1376-1378
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    • 1999
  • Most conventional protection relays are based on processing information in the spectrum that is close to or at power frequency. It is, however, widely known that faults on transmission lines produce frequency components of a wide range In this respect, this paper describes the basis of a Protection technique for transmission lines which utilises high-frequency components. Fault-generated signals caused by post-fault and the signal derived from stack tuner is connected to the coupling capacitor of CVT. Digital signal processing is then applied to the captured information to determine whether the fault is inside or outside the Protected zone, and to discriminate the fault type on transmission line.

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3D Vision-based Security Monitoring for Railroad Stations

  • Park, Young-Tae;Lee, Dae-Ho
    • Journal of the Optical Society of Korea
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    • 제14권4호
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    • pp.451-457
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    • 2010
  • Increasing demands on the safety of public train services have led to the development of various types of security monitoring systems. Most of the surveillance systems are focused on the estimation of crowd level in the platform, thereby yielding too many false alarms. In this paper, we present a novel security monitoring system to detect critically dangerous situations such as when a passenger falls from the station platform, or when a passenger walks on the rail tracks. The method is composed of two stages of detecting dangerous situations. Objects falling over to the dangerous zone are detected by motion tracking. 3D depth information retrieved by the stereo vision is used to confirm fallen events. Experimental results show that virtually no error of either false positive or false negative is found while providing highly reliable detection performance. Since stereo matching is performed on a local image only when potentially dangerous situations are found; real-time operation is feasible without using dedicated hardware.

Fatigue performance assessment of welded joints using the infrared thermography

  • Fan, J.L.;Guo, X.L.;Wu, C.W.
    • Structural Engineering and Mechanics
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    • 제44권4호
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    • pp.417-429
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    • 2012
  • Taking the superficial temperature increment as the major fatigue damage indicator, the infrared thermography was used to predict fatigue parameters (fatigue strength and S-N curve) of welded joints subjected to fatigue loading with a high mean stress, showing good predictions. The fatigue damage status, related to safety evaluation, was tightly correlated with the temperature field evolution of the hot-spot zone on the specimen surface. An energetic damage model, based on the energy accumulation, was developed to evaluate the residual fatigue life of the welded specimens undergoing cyclic loading, and a good agreement was presented. It is concluded that the infrared thermography can not only well predict the fatigue behavior of welded joints, but also can play an important role in health detection of structures subjected to mechanical loading.