• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권6호
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• pp.1166-1191
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• 2011

This paper presents an adaptive active tracking system with sector based scanning for a single PTZ camera. Dividing sectors on an image reduces the search space to shorten selection time so that the system can cover many targets. Upon the selection of a target, the system estimates the target trajectory to predict the zooming location with a finite amount of time for camera movement. Advanced estimation techniques using probabilistic reason suffer from the unknown object dynamics and the inaccurate estimation compromises the zooming level to prevent tracking failure. The proposed system uses the simple piecewise estimation with a few frames to cope with fast moving objects and/or slow camera movements. The target is tracked in multiple steps and the zooming time for each step is determined by maximizing the zooming level within the expected variation of object velocity and detection. The number of zooming steps is adaptively determined according to target speed. In addition, the iterative estimation of a zooming location with camera movement time compensates for the target prediction error due to the difference between speeds of a target and a camera. The effectiveness of the proposed method is validated by simulations and real time experiments.

• 한국정밀공학회지
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• 제21권3호
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• pp.74-82
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• 2004

This paper proposes a fast zooming and focusing technique for implementing a real-time surveillance camera system which can capture a face image in less than 1 second. It determines the positions of zooming and focusing lenses using two-step algorithm. In the first step, it moves the zooming and focusing lenses simultaneously to the positions calculated using the lens equations for achieving the predetermined magnification. In the second step the focusing lens is adjusted so that it is positioned at the place where the focus measure is the maximum. The camera system implemented for the experiments has shown that the proposed algorithm spends about 0.56 second on average fur obtaining a focused image.

• 한국해양공학회지
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• 제18권5호
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• pp.29-35
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• 2004

A new approach, referred to as a successive zooming genetic algorithm (SZGA), is proposed for identifying a global solution, using continuous zooming factors for optimization problems. In order to improve the local fine-tuning of the GA, we introduced a new method whereby the search space is zoomed around the design variable with the best fitness per 100 generation, resulting in an improvement of the convergence. Furthermore, the reliability of the optimized solution is determined based on the theory of probability, and the parameter used for the successive zooming method is optimized. With parameter optimization, we can eliminate the time allocated for deciding parameters used in SZGA. To demonstrate the superiority of the proposed theory, we tested for the minimization of a multiple function, as well as simple functions. After testing, we applied the parameter optimization to a truss problem and wicket gate servomotor optimization. Then, the proposed algorithm identifies a more exact optimum value than the standard genetic algorithm.

• 한국통신학회논문지
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• 제36권8B호
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• pp.904-909
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• 2011

셀 주밍은 트래픽 변화에 따라 기지국의 셀 범위를 적응적으로 변화시킬 수 있도록 한다. 이러한 셀주밍은 안테나 각도 조절, 기지국 클러스터링 혹은 셀 릴레이를 통해 구현될 수 있다. 셀룰러 네트워크는 셀주밍을 이용하여 에너지 효율적으로 셀 범위를 조절하여 기지국에 소비되는 에너지를 절감할 수 있다. 하지만 기지국의 소비 에너지 절감과 사용자 측면에서의 호 단절 확률 간에는 trade-off가 있어 적절한 관리방법이 필요하다. 이를 위해 주기적으로 기지국들의 셀 주밍을 조절하는 방식이 사용되었다. 그러나 이 방식은 일정주기에 따라 동작하기 때문에 동적 특성을 가지는 트래픽의 경우에 적절하지 못하다는 단점을 가지고 있다. 본 논문에서는 트래픽 상황에 따라 반주기적 (semi-periodic)으로 기지국의 셀주밍을 관리하는 방식을 제안했다. 이와 관련하여 반주기적 셀주밍을 하는 기지국 선정방법과 그러한 기지국들의 동작방식도 제안했다. 시뮬레이션을 통한 성능평가에서 제안방식이 기존 방식보다 에너지 소비를 절감하면서도 비슷한 수준의 호 단절 확률을 유지할 수 있는 것을 확인하였다.

• 대한인간공학회지
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• 제27권4호
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• pp.15-26
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• 2008

Recently, Internet Protocol TV technology has a latent power for searching information by using internet-connected interactive TV media. It is hard to browse and search web site conveniently since the visual and input devices are not sufficient for navigating through the websites. Zoomable user interface is a possible solution that may reduce users' task load and improve their performance. In this paper, we made three types of web browsers as scroll, physical zooming and semantic zooming type. Fifteen participants asked to do searching tasks and their task time, accuracy and subjective responses are recorded. In the result, though scroll type is evaluated more efficient than other types in task time and accuracy since participants are familiar with scroll type interface, semantic zooming type is highly rated in subjective responses such as perceived searching efficiency, satisfaction and joyfulness. This result implied semantic zooming is a possible solution which is improving user experience of searching websites using Internet Protocol TV.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.98.5-98
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• 2002

1. Introduction 2. System Overview 3. Tracking and Auto Zooming algorithm 3.2 Automatic ROI Setting 3.3 Escaping of the local distracters 4. Pan/Tilt Control System, Performance Evaluation 5. Conclusion

• 한국광학회:학술대회논문집
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• 한국광학회 1988년도 광학 및 양자전자학 워크샵
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• pp.59-67
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• 1988

연속적으로 aplanat 조건을 만족하는 4 반사경의 zooming에서 aplanat 4구면 반사광학계가 갖는 astigmatism을 줄이기 위하여 4구면 중 하나의 반사경에 원추곡면을 사용함으로써 줌 궤적상의 한점에서 anatsigmat 조건을 만족하도록 하였다. 이방법에 의한 astigmatism 의 보정효과는 제 1 면에 ellipsoid를 사용하였을 때 가장 우수하였다.

• 대한기계학회논문집A
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• 제26권2호
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• pp.406-414
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• 2002

A new approach, referred to as a successive zooming genetic algorithm (SZGA), is Proposed for identifying a global solution for continuous optimization problems. In order to improve the local fine-tuning capability of GA, we introduced a new method whereby the search space is zoomed around the design point with the best fitness per 100 generation. Furthermore, the reliability of the optimized solution is determined based on the theory of probability. To demonstrate the superiority of the proposed algorithm, a simple genetic algorithm, micro genetic algorithm, and the proposed algorithm were tested as regards for the minimization of a multiminima function as well as simple functions. The results confirmed that the proposed SZGA significantly improved the ability of the algorithm to identify a precise global minimum. As an example of structural optimization, the SZGA was applied to the optimal location of support points for weight minimization in the radial gate of a dam structure. The proposed algorithm identified a more exact optimum value than the standard genetic algorithms.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1318-1321
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• 1997

A method for two-dimensional position measurement using an enclosing field has been studied and reported. The feature of this mehtod is zooming functional measurement by operating both the initial phase shift and the brightness ratio of the lighting function. An experimental system was developed and the experimental results on zooming effects are shown in this paper. This system is also an example of a "progressive learning measurement system".tem".uot;.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.71-75
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• 2009

In this paper, we present a real-time method to detect moving objects in a rotating and zooming camera. It is useful for camera surveillance of fixed but rotating camera, camera on moving car, and so on. We first compensate the global motion, and then exploit the displaced frame difference (DFD) to find the block-wise boundary. For robust detection, we propose a kind of image to combine the detections from consecutive frames. We use the block-wise detection to achieve the real-time speed, except the pixel-wise DFD. In addition, a fast block-matching algorithm is proposed to obtain local motions and then global affine motion. In the experimental results, we demonstrate that our proposed algorithm can handle the real-time detection of common object, small object, multiple objects, the objects in low-contrast environment, and the object in zooming camera.