• 한국IT서비스학회지
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• 제15권4호
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• pp.97-109
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• 2016

The rapid deployment of millions of mobile sensors and smart devices has resulted in high demand for opportunistic encounter-based networking. For the cooperative video surveillance of dashboard cameras in nearby vehicles, a fast and energy-efficient asynchronous neighbor discovery protocol is indispensable because a dashboard camera is an energy-hungry device after the vehicle's engine has turned off. In the existing asynchronous neighbor discovery protocols, all nodes always try to discover all neighbors. However, a dashboard camera needs to discover nearby dashboard cameras when an event is detected. In this paper, we propose a fast and energy-efficient asynchronous neighbor discovery protocol, which enables nodes : 1) to have different roles in neighbor discovery, 2) to discover neighbors within a search range, and 3) to report promptly the exact discovery result. The proposed protocol has two modes: periodic wake-up mode and active discovery mode. A node begins with the periodic wake-up mode to be discovered by other nodes, switches to the active discovery mode on receiving a neighbor discovery request, and returns to the periodic wake-up mode when the active discovery mode finishes. In the periodic wake-up mode, a node wakes up at multiples of number ${\alpha}$, where ${\alpha}$ is determined by the node's remaining battery power. In the active discovery mode, a node wakes up for consecutive ${\gamma}$ slots. Then, the node operating in the active discovery mode can discover all neighbors waking up at multiples of ${\beta}$ for ${\beta}{\leq}{\gamma}$ within ${\gamma}$ time slots. Since the proposed protocol assigns one half of the duty cycle to each mode, it consumes equal to or less energy than the existing protocols. A performance comparison shows that the proposed protocol outperforms the existing protocols in terms of discovery latency and energy consumption, where the frequency of neighbor discovery requests by car accidents is not constantly high.

• Journal of Platform Technology
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• 제12권3호
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• pp.62-70
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• 2024

최근의 감시 시스템은 카메라, 레이더 등 다양한 센서를 중복 사용하여 침입 탐지의 정확도를 향상시키려는 노력을 기울이고 있다. 그러나 야간, 악천후, 침입자의 위장 등으로 인해 카메라(RGB, Thermal) 센서를 통한 객체 인식이 정확하지 않을 때도 있다. 이러한 상황에서는 카메라나 레이더 센서를 통해 추출된 객체의 궤적을 활용하여 침입자를 탐지할 수 있다. 본 논문에서는 객체 인식이 어려운 환경에서 궤적 정보만을 이용하여 침입자를 탐지하는 방법을 제안한다. 제안하는 방법은 동물, 사람의 정상 및 비정상(침입, 배회) 궤적 데이터를 이용하여 LSTM-Attention 기반 궤적 분류 모델을 학습하고, 이 모델을 이용해서 사람의 비정상 궤적을 찾아내서 침입 탐지를 수행한다. 마지막으로, 제안하는 방법의 타당성을 실 데이터를 이용한 실험을 통해 입증한다.

• Journal of information and communication convergence engineering
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• 제9권3호
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• pp.347-352
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• 2011

In this paper, although Radar has been used for a long time, integrated scheme with visual camera is an efficient way to enhance marine surveillance system. Camera image is focused by radar information but it is easy to be fallen into inaccurate operation due to environmental noises. We have proposed a method to filter the noises by moving average filter and Kalman filter. It is proved that Kalman filtered results preserves linearity while the former includes larger variance.

• 로봇학회논문지
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• 제13권1호
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• pp.45-54
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• 2018

This paper presents a vision-based fall detection system to automatically monitor and detect people's fall accidents, particularly those of elderly people or patients. For video analysis, the system should be able to extract both spatial and temporal features so that the model captures appearance and motion information simultaneously. Our approach is based on 3-dimensional convolutional neural networks, which can learn spatiotemporal features. In addition, we adopts a thermal camera in order to handle several issues regarding usability, day and night surveillance and privacy concerns. We design a pan-tilt camera with two actuators to extend the range of view. Performance is evaluated on our thermal dataset: TCL Fall Detection Dataset. The proposed model achieves 90.2% average clip accuracy which is better than other approaches.

• 한국측량학회지
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• 제28권4호
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• pp.403-411
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• 2010

This research demonstrates a 3D virtual visualization of urban environment and video fusion for effective damage prevention and surveillance system using open standard. We present the visualization and interaction simulation method to increase the situational awareness and optimize the realization of environmental monitoring through the CCTV video and 3D virtual environment. New camera prototype was designed based on the camera frustum view model to project recorded video prospectively onto the virtual 3D environment. The demonstration was developed by the X3D, which is royalty-free open standard and run-time architecture, and it offers abilities to represent, control and share 3D spatial information via the internet browsers.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.802-804
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• 2011

CCTV를 이용해 다양한 관제시스템을 구축하고 있는 상황에서, 악의적인 해킹으로 관제 시스템이 일부만 동작하는 상황을 대비하기 위한 연구를 수행 하였다. 현재 운용 중인 방범용 CCTV 관제 시스템을 실험 대상으로, 정상적인 상황과, 일부 CCTV 카메라가 동작하지 않는 상황을 두고, 관제 운용 영역을 감소시켜 보았다. 그리고 이 성능 저하를 객관적으로 나타내기 위한 규칙을 제시하였다.

• 전기학회논문지
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• 제61권1호
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• pp.143-147
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• 2012

The rapid growth of camera technology can provide various types of information which was not previously provided. Furthermore, IP camera which has rapid data transfer rate and high resolution particularly provide a lot of useful functions beyond the existing simple surveillance capabilities. We are developing Real-Time Face Recognition Access Control System based on the camera technology, and improvement of face detection and recognition algorithms are vitally needed to realize that system. In this paper, we proposes a method to improve the computing speed and detection rate by adding new features to the existing Viola-Jones detection algorithm.

• 한국컴퓨터정보학회논문지
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• 제23권1호
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• pp.25-32
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• 2018

In this paper, we propose an edge detection algorithm for auto focus of infrared camera. We designed and implemented the edge detection of infrared image by using a spatial filter on FPGA. The infrared camera should be designed to minimize the image processing time and usage of hardware resource because these days surveillance systems should have the fast response and be low size, weight and power. we applied the $3{\times}3$ mask filter which has an advantage of minimizing the usage of memory and the propagation delay to process filtering. When we applied Laplacian filter to extract contour data from an image, not only edge components but also noise components of the image were extracted by the filter. These noise components make it difficult to determine the focus state. Also a bad pixel of infrared detector causes a problem in detecting the edge components. So we propose an adaptive edge detection filter that is a method to extract only edge components except noise components of an image by analyzing a variance of pixel data in $3{\times}3$ memory area. And we can detect the bad pixel and replace it with neighboring normal pixel value when we store a pixel in $3{\times}3$ memory area for filtering calculation. The experimental result proves that the proposed method is effective to implement the edge detection for auto focus in infrared camera.

• 한국전자통신학회논문지
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• 제17권6호
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• pp.1025-1032
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• 2022

본 논문에서는 기존 유선기반 CCTV 감시시스템과 IP 카메라 시스템에서 발생되는 구축비용에 대한 부담을 절감하고자 무선 통신기술을 활용한 TDMA기반 PoE 무선 다중 IP 카메라 전송시스템 개발이며, 국산 무선통신기술을 활용한 고화질 영상의 원거리 무선 전송 기술에 대해 설계 및 구현 하고자 한다. 제안 관련 기술에 대한 선 IP 전송 시스템의 송수신 프로토타입과 무선 다중 IP 카메라 전송 단말장치 및 영상 수집 장치(SB-200)에 대해 기술하였다.

• 한국전자통신학회논문지
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• 제18권1호
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• pp.1-10
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• 2023

본 논문에서는 기존 유선기반 CCTV 감시시스템과 IP 카메라 시스템에 국산 무선통신기술을 활용한 고화질 영상의 원거리 무선 전송 기술에 대해 설계 및 구현에 대해 성능 평가을 하였다. 무선 다중 IP 카메라 전송 단말장치및 무선통신 RF 모듈간 연동시험과 무선 다중 IP 카메라 기반 영상전송시스템 통합 연동시험으로 영상 전송 시 모듈 연동 적합성을 확인한다.