• 과학교육연구지
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• 제39권3호
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• pp.333-342
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• 2015

이 연구는 단계적 상황 교수자료를 개발하고 대학 물리학 수업에 적용하여 물리 학습에 대한 효과를 조사하는 데 있다. 연구대상은 지방 소재 대학의 사범대학 자연계열 1학년 대학생 총 35명으로 했다. 단계적 상황 교수자료는 상황 이상화하기, 상황 확장하기, 상황 비교하기 단계로 개발하고, 일차원 운동, 이차원 운동, 뉴턴의 운동 법칙 등 6차시 물리 수업에 적용했다. 물리 학습에 대한 효과는 힘 개념 검사지(FCI)와 물리 학습에 대한 신념(MPEX) 설문지를 사용하여 조사했다. 연구결과 단계적 상황 교수자료는 대학생의 힘 개념 변화에는 효과가 있었지만, 물리 학습에 대한 신념에는 유의미한 변화가 없었다. 결론적으로 단계적 상황 교수 학습 전략으로 개발된 교수자료는 학생에게 과학개념을 다양한 상황에 적용하는 기회를 주어 물리 개념 변화를 돕는 데 효과가 있다. 끝으로 연구 결과들을 통해 단계적 상황 물리 수업에 대한 교육적 시사점을 논의했다.

• 정보과학회 논문지
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• 제41권11호
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• pp.900-910
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• 2014

다시점 비디오는 하나의 3차원 장면을 여러 시점에서 다수의 카메라로 촬영 영상으로 다시점 비디오 부호화의 계산량은 카메라 수에 비례하여 증가한다. 본 논문에서는 다시점 비디오 부호화의 계산량을 줄이면서 영상 화질을 유지하는 예측 구조와 움직임 추정 기법을 제안한다. 제안한 개선된 예측 구조는 B계층 최대 인덱스 그리고 각 Bi계층의 화면수를 고려하였다. 제안한 움직임 추정 기법은 계층적인 탐색 기법으로 수정된 다이아몬드 탐색 패턴, 점진적인 다이아몬드 탐색 패턴 그리고 수정된 래스터 탐색 패턴으로 구성된다. 제안한 예측 구조와 움직임 추정 기법의 성능을 Fraunhofer-HHI의 계층적 B화면 구조와 TZ 움직임 추정 기법을 사용한 JMVC 참조 모델의 성능과 비교한 경우, 영상 화질과 발생 비트량은 비슷하지만 다시점 비디오 부호화의 계산량을 40~70% 줄인다.

• Journal of Information Technology Applications and Management
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• 제10권3호
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• pp.45-54
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• 2003

Security system with web camera remarkably has been developed at an Internet era. Using transmitted images from remote camera, the system can recognize current situation and take a proper action through web. Existing motion detection methods use simply difference image, background image techniques or block matching algorithm which establish initial block by set search area and find similar block. But these methods are difficult to detect exact motion because of useless noise. In this paper, the proposed method is updating changed background image as much as $N{\times}M$pixel mask as time goes on after get a difference between imput image and first background image. And checking image pixel can efficiently detect motion by computing fixed distance pixel instead of operate all pixel.

• Structural Engineering and Mechanics
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• 제51권6호
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• pp.909-922
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• 2014

In this paper, we present an alternative seismic design strategy for cable stayed bridges with concrete pylons when subjected to strong ground motions. The comparison of conventional seismic design using supplemental dampers (strategy A) and the new strategy using nonlinear seismic design of pylon columns (strategy B) is exemplified by one typical medium span cable stayed bridge subjected to strong ground motions from 1999 Taiwan Chi-Chi earthquake and 2008 China Wenchuan earthquake. We first conducted the optimization of damper parameters according to strategy A in response to the distinct features that strong ground motions contain. And then we adopted strategy B to carry out seismic analysis by introducing the elastic-plastic elements that allowing plasticity development in the pylon columns. The numerical results show that via strategy A, the earthquake induced structural responses can be kept in the desired range provided with the proper damping parameters, however, the extra cost of unusual dampers will be inevitable. For strategy B, the pylon columns may not remain elastic and certain plasticity developed, but the seismic responses of the foundation will be greatly decreased, meanwhile, the displacement at the top of pylon seems to be not affected much by the yielding of pylon columns, which indicates the pylon nonlinear design can be an alternative design strategy when strong ground motions have to be considered for the bridge.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권9호
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• pp.4438-4460
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• 2017

The Kernelized Correlation Filters (KCF) tracker has caused the extensive concern in recent years because of the high efficiency. Numerous improvements have been made successively. However, due to the abrupt motion between the consecutive image frames, these methods cannot track object well. To cope with the problem, we propose an extended KCF tracker based on swarm intelligence method. Unlike existing KCF-based trackers, we firstly introduce a swarm-based sampling method to KCF tracker and design a unified framework to track smooth or abrupt motion simultaneously. Secondly, we propose a global motion estimation method, where the exploration factor is constructed to search the whole state space so as to adapt abrupt motion. Finally, we give an adaptive threshold in light of confidence map, which ensures the accuracy of the motion estimation strategy. Extensive experimental results in both quantitative and qualitative measures demonstrate the effectiveness of our proposed method in tracking abrupt motion.

• Earthquakes and Structures
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• 제10권1호
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• pp.239-260
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• 2016

Tuned mass dampers (TMDs) have been frequently proposed to mitigate the detrimental effects of dynamic loadings in structural systems. The effectiveness of this protection strategy has been demonstrated for wind-induced vibrations and, to some extent, for seismic loadings. Within this framework, recent numerical studies have shown that beneficial effects can be achieved by placing a linear TMD on the roof of linear elastic structural systems subjected to pulse-like ground motions. Motivated by these positive outcomes, closed-form design formulations have been also proposed to optimize the device's parameters. For structural systems that undergo a near-fault pulse-like ground motion, however, it is unlikely that their dynamic response be linear elastic. Hence, it is very important to understand whether such strategy is effective for inelastic structural systems. In order to provide new useful insights about this issue, the paper presents statistical results obtained from a numerical study conducted for three shear-type hysteretic (softening-type) systems having 4, 8 and 16 stories equipped with a linear elastic TMD. The effectiveness of two design procedures is discussed by examining the performances of the protected systems subjected to 124 natural pulse-like earthquakes.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권2호
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• pp.188-200
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• 2018

This paper proposes a single control strategy to solve the problem of trans-media vehicle difficult control. The proposed control strategy is just to control the vehicle's air navigation, but not to control the underwater navigation. The hydrodynamic model of a vehicle when entering water obliquely at low speed has been founded to analyze the motion characteristics. Two methods have been used to simulate the vehicle entering water in the same condition: numerical simulation method and theoretical model solving method. And the results of the two methods can validate the hydrodynamic model founded in this paper. The entering water motion in the conditions of different velocity, different angle, and different attack angle has been simulated by this hydrodynamic model and the simulation has been analyzed. And the change rule of the vehicle's gestures and position when entering water has been obtained by analysis. This entering water rule will guide the follow-up of a series of research, such as the underwater navigation, the exiting water process and so on.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권2호
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• pp.855-870
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• 2019

In this paper, an adaptive iterative algorithm is proposed for motion deblurring by using the salient intensity prior. Based on the observation that the salient intensity of the clear image is sparse, and the salient intensity of the blurred image is less sparse during the image blurring process. The salient intensity prior is proposed to enforce the sparsity of the distribution of the saliency in the latent image, which guides the blind deblurring in various scenarios. Furthermore, an adaptive iteration strategy is proposed to adjust the number of iterations by evaluating the performance of the latent image and the similarity of the estimated blur kernel. The negative influence of overabundant iterations in each scale is effectively restrained in this way. Experiments on publicly available image deblurring datasets demonstrate that the proposed algorithm achieves state-of-the-art deblurring results with small computational costs.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 춘계학술대회논문집
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• pp.64-71
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• 2000

Yard cranes are very useful equipments for handling of heavy containers. But rope-driven yard cranes must have a little of sway and skew motion because ropes are passive mechanical device. So many researches have been concentrated on anti-sway algorithm controlling trolley speed. These approaches require sway angle. But it is very difficult to know sway angle and its derivative. Therefore control algorithm of trolley speed is not practical in general. On the contrary, control strategy using auxiliary rope is very useful to sway control of yard crane because rope length is shorter than quay-side container cranes. In this paper, we derive equations of motion of trolley system which have anti-sway controller to use auxiliary rope. And we propose the control strategy and analyse the behavior of the proposed system.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 추계학술대회논문집
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• pp.143-151
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• 2000

Yard cranes are very useful equipments for handling of heavy containers. But rope-driven yard cranes must have a little of sway and skew motion because ropes are passive mechanical device. So many researches have been concentrated on anti-sway algorithm controlling trolley speed. These approaches require sway angle. But it is very difficult to know sway angle and its derivative. Therefore control algorithm of trolley speed is not practical in general. On the contrary, control strategy using auxiliary rope is very useful to sway control of yard crane because rope length is shorter than quay-side container cranes. In this paper, we derive equations of motion of trolley system which have anti-sway controller to use auxiliary rope. And we propose the control strategy and analyse the behavior of the proposed system.