• Journal of Astronomy and Space Sciences
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• 제26권4호
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• pp.529-546
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• 2009

인공위성 광학 감시 시스템 적용에 가장 효과적인 고전적 예비궤도 결정법은 Gauss와 Laplace 방법이 있다. 이 두 방법은 세 쌍의 광학 관측 자료를 이용하여 위성의 궤도를 결정하는 방법으로 관측 시간간격에 따라 정밀도가 변화하는 특성이 있다. 이번 연구에서는 이러한 특성에 관련된 국내의 기존 연구 결과들에서 일부 상이한 점을 발견하여, 세 점의 시간간격에 대한 정밀도 변화 특성을 재검토해 보았다. 이러한 특성 연구는 다양한 위성 궤도 형태를 고려해야 하기 때문에 궤도 정보가 알려진 위성 전체를 대상으로 하였다. SGP4/SDP4 궤도전파 모델을 이용한 모의 관측 자료를 사용하여 방법론적인 정밀도 특성 을 확인하였고, 특정 위성의 실제 관측 자료를 사용 하여 인공위성 광학 감시 시스템에 적용할 시에 발생되는 특성을 확인하였다. 결과적으로, 세 점의 시간간격에 대한 최기궤도 결정의 정밀도 변화 특성은 관측된 위성의 위치로 인해 달라질 수 있음을 확인하였다.

• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.288-296
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• 2021

Automated face recognition in a runtime environment is gaining more and more important in the fields of surveillance and urban security. This is a difficult task keeping in mind the constantly volatile image landscape with varying features and attributes. For a system to be beneficial in industrial settings, it is pertinent that its efficiency isn't compromised when running on roads, intersections, and busy streets. However, recognition in such uncontrolled circumstances is a major problem in real-life applications. In this paper, the main problem of face recognition in which full face is not visible (Occlusion). This is a common occurrence as any person can change his features by wearing a scarf, sunglass or by merely growing a mustache or beard. Such types of discrepancies in facial appearance are frequently stumbled upon in an uncontrolled circumstance and possibly will be a reason to the security systems which are based upon face recognition. These types of variations are very common in a real-life environment. It has been analyzed that it has been studied less in literature but now researchers have a major focus on this type of variation. Existing state-of-the-art techniques suffer from several limitations. Most significant amongst them are low level of usability and poor response time in case of any calamity. In this paper, an improved face recognition system is developed to solve the problem of occlusion known as FRS-OCC. To build the FRS-OCC system, the color and texture features are used and then an incremental learning algorithm (Learn++) to select more informative features. Afterward, the trained stack-based autoencoder (SAE) deep learning algorithm is used to recognize a human face. Overall, the FRS-OCC system is used to introduce such algorithms which enhance the response time to guarantee a benchmark quality of service in any situation. To test and evaluate the performance of the proposed FRS-OCC system, the AR face dataset is utilized. On average, the FRS-OCC system is outperformed and achieved SE of 98.82%, SP of 98.49%, AC of 98.76% and AUC of 0.9995 compared to other state-of-the-art methods. The obtained results indicate that the FRS-OCC system can be used in any surveillance application.

• 우주기술과 응용
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• 제4권2호
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• pp.169-183
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• 2024

한국천문연구원은 인공위성 정밀 궤도 결정, 우주 감시, 우주 측지 등 과학 연구 및 국가적 우주 미션을 수행하기 위해 거창 SLR(satellite laser ranging) 시스템을 개발하였다. 시스템을 구성하는 여러 서브시스템 중 하나인 운영 시스템은 다른 서브시스템을 제어하고 관측 알고리즘을 기반으로 수동 및 자동 관측 모드를 제공하여, 지상에서 인공위성까지의 거리를 계산하는 소프트웨어로써 네트워크 기반의 서버와 클라이언트 방식으로 개발되었다. 본 연구에서는 운영 시스템의 요구사항을 분석하고, 서버 및 클라이언트 통신을 위한 개발환경, 소프트웨어 구조 및 관측 알고리즘을 기술한다. 그리고 개발된 운영 시스템을 이용하여 지상보정 및 측지 전용 인공위성 STARLETTE에 대한 레이저 추적을 통해 취득한 관측 데이터를 처리하여 ILRS(international laser ranging service) 국제기구에서 배포한 전 세계 SLR 관측소와 거리측정 정밀도를 비교 분석하였다.

• 안보군사학연구
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• 통권2호
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• pp.285-314
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• 2004

The forms of current war are diversified over the pan-national industry. Among these, one kind of threats which has permeated the cyber space based on the advanced information technology causes a new type of war. C4ISR, the military IT revolution, as a integrated technology innovation of Command, Control, Communications, Computer, Intelligence, Surveillance and Reconnaissance suggests that the aspect of the future war hereafter is changing much. In this paper, we design the virtual decoy system and intrusion trace marking mechanism which can capture various attempts and evidence of intrusion by hackers in cyber space, trace the penetration path and protect a system. By the suggested technique, we can identify and traceback the traces of intrusion in cyber space, or take a legal action with the seized evidence.

• 한국실천공학교육학회논문지
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• 제2권1호
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• pp.84-88
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• 2010

최근들어 보안이 중요시되는 공간에서 임의의 객체를 추적하고 인식할 수 있는 시스템의 필요성이 점차 중요시 되고 있다. 이에 따라 본 논문에서는 효율적인 영상 처리 교육을 위한 지능형 영상 시스템을 구현하고 제안하고자 한다. 제안된 시스템은 검지 영역내 차량의 진입 및 추적 실험을 하였고, 차량이 검지영역 내에서 정차시 Pan-Tilt-Zoom 카메라를 제어하여 객체의 확대 영상을 취득하도록 하였다. 실험 결과 움직이는 차량의 경우 97.4%, 정차해 있는 차량의 경우 91%의 추적율을 나타내었다. 또한 제안된 시스템은 교육진행시 실시간 영상 데이터 사용 및 카메라 제어를 다수의 학생들이 동시에 할 수 있음으로 효율적인 영상 처리 교육을 진행 할 수 있을 것으로 사료된다.

• Journal of Information Processing Systems
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• 제10권1호
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• pp.1-22
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• 2014

Recent technological advances provide the opportunity to use large amounts of multimedia data from a multitude of sensors with different modalities (e.g., video, text) for the detection and characterization of criminal activity. Their integration can compensate for sensor and modality deficiencies by using data from other available sensors and modalities. However, building such an integrated system at the scale of neighborhood and cities is challenging due to the large amount of data to be considered and the need to ensure a short response time to potential criminal activity. In this paper, we present a system that enables multi-modal data collection at scale and automates the detection of events of interest for the surveillance and reconnaissance of criminal activity. The proposed system showcases novel analytical tools that fuse multimedia data streams to automatically detect and identify specific criminal events and activities. More specifically, the system detects and analyzes series of incidents (an incident is an occurrence or artifact relevant to a criminal activity extracted from a single media stream) in the spatiotemporal domain to extract events (actual instances of criminal events) while cross-referencing multimodal media streams and incidents in time and space to provide a comprehensive view to a human operator while avoiding information overload. We present several case studies that demonstrate how the proposed system can provide law enforcement personnel with forensic and real time tools to identify and track potential criminal activity.

• 로봇학회논문지
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• 제6권3호
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• pp.210-219
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• 2011

This paper studies how to combine devices such as monocular/stereo cameras, motors for panning/tilting, fisheye lens and convex mirrors, in order to solve vision-based robotic problems. To overcome the well-known trade-offs between optical properties, we present two mixed versions of the new systems. The first system is the robot photographer with a conventional pan/tilt perspective camera and fisheye lens. The second system is the omnidirectional detector for a complete 360-degree field-of-view surveillance system. We build an original device that combines a stereo-catadioptric camera and a pan/tilt stereo-perspective camera, and also apply it in the real environment. Compared to the previous systems, we show benefits of two proposed systems in aspects of maintaining both high-speed and high resolution with collaborative moving cameras and having enormous search space with hybrid configuration. The experimental results are provided to show the effectiveness of the mixing collaborative and hybrid systems.

• 로봇학회논문지
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• 제2권1호
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• pp.21-28
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• 2007

The Intelligent Space(ISpace) provides challenging research fields for surveillance, human-computer interfacing, networked camera conferencing, industrial monitoring or service and training applications. ISpace is the space where many intelligent devices, such as computers and sensors, are distributed. According to the cooperation of many intelligent devices, the environment, it is very important that the system knows the location information to offer the useful services. In order to achieve these goals, we present a method for representing, tracking and human following by fusing distributed multiple vision systems in ISpace, with application to pedestrian tracking in a crowd. And the article presents the integration of color distributions into particle filtering. Particle filters provide a robust tracking framework under ambiguity conditions. We propose to track the moving objects by generating hypotheses not in the image plan but on the top-view reconstruction of the scene. Comparative results on real video sequences show the advantage of our method for multi-object tracking. Also, the method is applied to the intelligent environment and its performance is verified by the experiments.

• International Journal of Aeronautical and Space Sciences
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• 제18권4호
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• pp.767-779
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• 2017

Automated mission planning for unmanned aerial vehicles (UAVs) is difficult because of the propagation of several sources of error into the solution, as for any large scale autonomous system. To ensure reliable system performance, we quantify all sources of error and their propagation through a mission planner for operation of UAVs in an obstacle rich environment we developed in prior work. In this sequel to that work, we show that the mission planner developed before can be made robust to errors arising from the mapping, sensing, actuation, and environmental disturbances through creating systematic buffers around obstacles using the calculations of uncertainty propagation. This robustness makes the mission planner truly autonomous and scalable to many UAVs without human intervention. We illustrate with simulation results for trajectory generation of multiple UAVs in a surveillance problem in an urban environment while optimizing for either maximal flight time or minimal fuel consumption. Our solution methods are suitable for any well-mapped region, and the final collision free paths are obtained through offline sub-optimal solution of an mTSP (multiple traveling salesman problem).

• International Journal of Aeronautical and Space Sciences
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• 제10권2호
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• pp.148-160
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• 2009

By the development of recent technology, a new variant of rotorcrafts having four rotors start drawing attention from aerial-robotics engineers more than before. Its potential spans from just being control device test bed to performing difficult task such as carrying surveillance device to unreachable places. In this regards, modeling a quad-rotor is significant in analyzing its dynamic behavior and in synthesizing control system for such a vehicle. This paper summarizes the modeling of a mini quad-rotor aerial vehicle. A first principle approach is considered for deriving the model based on Euler-Newton equations of motion. The result of the modeling is a simulation platform that is expected to acceptably predict the dynamic behavior of the quad-rotor in various flight conditions. Linear models associated with different flight condition can be extracted for the purpose of control synthesis.