• Journal of Positioning, Navigation, and Timing
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• 제3권1호
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• pp.1-10
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• 2014

Recently, monitoring of two-body ground vehicles carrying extremely hazardous materials has been considered as one of the most important national issues. This issue induces large cost in terms of national economy and social benefit. To monitor and counteract accidents promptly, an efficient methodology is required. For accident monitoring, GPS can be utilized in most cases. However, it is widely known that GPS cannot provide sufficient continuity in urban cannons and tunnels. To complement the weakness of GPS, this paper proposes an accident monitoring method based on a monocular vision sensor. The proposed method estimates angular acceleration from a sequence of image frames captured by a monocular vision sensor. The possibility of using angular acceleration is investigated to determine the occurrence of accidents such as jackknifing and rollover. By an experiment based on actual measurements, the feasibility of the proposed method is evaluated.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권1호
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• pp.50-58
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• 2013

Estimating a driver's head pose is an important task in driver-assistance systems because it can provide information about where a driver is looking, thereby giving useful cues about the status of the driver (i.e., paying proper attention, fatigued, etc.). This study proposes a system for estimating the head pose using monocular images, which includes a novel use of backprojection. The system can use a single image to estimate a driver's head pose at a particular time stamp, or an image sequence to support the analysis of a driver's status. Using our proposed system, we compared two previous pose estimation approaches. We introduced an approach for providing ground-truth reference data using a mannequin model. Our experimental results demonstrate that the proposed system provides relatively accurate estimations of the yaw, tilt, and roll angle. The results also show that one of the pose estimation approaches (perspective-n-point, PnP) provided a consistently better estimate compared to the other (pose from orthography and scaling with iterations, POSIT) using our proposed system.

• 정보처리학회논문지B
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• 제17B권6호
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• pp.429-436
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• 2010

본 논문에서는 단일 카메라로부터 획득한 영상으로부터 물체의 3차원 윤곽선을 구성하는 방법을 제안한다. MOPS(Multi-Scale Oriented Patches) 알고리즘을 이용하여 물체의 대략적인 윤곽선을 검출하고 윤곽선 위에 분포한 특징점의 공간좌표를 획득한다. 동시에 SIFT(Scale Invariant Feature Transform) 알고리즘을 통하여 물체의 윤곽선 내부에 존재하는 특징점 공간좌표를 획득한다. 이러한 정보를 병합하여 물체의 전체 3차원 윤곽선 정보를 구성한다. 본 논문에서 제안하는 방법은 대략적인 물체의 윤곽선만 구성하기 때문에 빠른 계산이 가능하며 SIFT 특징점을 통해 윤곽선 내부 정보를 보완하기 때문에 물체의 자세한 3차원 정보를 얻을 수 있는 장점이 있다.

• 한국멀티미디어학회논문지
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• 제23권2호
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• pp.127-134
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• 2020

In this paper, we propose a map alignment method for maps generated by point-line monocular SLAM. In the proposed method, the information of feature lines as well as feature points extracted from multiple maps are fused into a single map. To this end, the proposed method first searches for similar areas between maps via Bag-of-Words-based image matching. Thereafter, it calculates the similarity transformation between the maps in the corresponding areas to align the maps. Finally, we merge the overlapped information of multiple maps into a single map by removing duplicate information from similar areas. Experimental results show that maps created by different users are combined into a single map, and the accuracy of the fused map is similar with the one generated by a single user. We expect that the proposed method can be utilized for fast imagery map generation.

• 한국안광학회지
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• 제14권4호
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• pp.71-75
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• 2009

목적: 광주지역에서 근시안경 착용 초등학생을 대상으로 착용안경의 굴절상태와 사위 및 단안PD 상태를 파악해 보고자 한다. 방법: 근시안경 착용 초등학생 145명(290안)을 대상으로 사위 및 단안PD 검사 후 자각적 타각적 굴절검사를 실시하였다. 결과: 1. 양안 2.00D이상 굴절성부등시에 해당되는 학생은 4명(3%)으로 나타났다. 2. 남학생 저교정 시력 19명 중 부등시는 9명(47%)이며 여학생 저교정 시력 25명 중 부등시는 16명(64%)으로 나타났다. 3.67명의 근시안경 착용 남학생중 동공중심과 안경의 광학중심점이 일치된 안경은 30%(양안), 동공중심과 광학중심점이 불일치된 안경은 70%(양안)이다. 78명의 근시안경 착용 여학생의 경우 동공중심과 안경의 광학중심점이 일치된 안경은 23%(양안), 동공중심과 광학중심점이 불일치된 안경은 77%(양안), 동공중심거리와 안경의 광학중심점 거리는 남녀 모두 안경의 광학중심점 거리가 더 크게 나타났다. 4. 사위검사결과 원거리에서 정위가 14%, 외사위는 63%, 내사위는 23%이다. 근거리에서 정위가 10%, 외사위는 76%, 내사위는 14%로 나타났다. 결론: 부정확한 굴절 검사와 잘못된 PD로 안경을 착용하면 안정피로 및 사위를 유발시킬 수 있기 때문에 정확한 굴절검사와 단안PD를 측정하여 안경을 착용 하는 것이 좋을 것 같다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.588-591
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• 2004

In this paper, we propose a ground plane detection algorithm, using a new image processing method (IPD). To extract the ground plane from the color image acquired by monocular camera, we use a new identical pixel detection method (IPD) and an edge detection method. This IPD method decides whether the pixel is identical with the ground plane pixel or not. The IPD method needs the reference area and its performance depends on the reference area size. So we propose the reference area auto-expanding algorithm in accordance with situation. And we evaluated the proposed algorithm by the experiments in the various environments. From the experiments results, we know that the proposed algorithm is efficient in the real indoor environment.

• 대한인간공학회지
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• 제23권2호
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• pp.25-36
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• 2004

The effects of task characteristics on the relative efficiency of visual display dimension were studied using a simulated tele-robotic task. Through a conventional method of task analysis. the tele-robotic task was divided into two categories: the task element requiring focused attention (FA task) and the task element requiring global attention (CA task). Time-ta-completion data were collected for a total of 120 trials involving 10 participants. For the CA task. there was no significant difference between the multiple two-dimensional (20) display and the three-dimensional (3D) monocular display. For the FA task. however. the multiple 20 display was superior to the 3D monocular display. The results suggest that the characteristics of a given task have a considerable effect on the choice of display dimensionality and the multiple 3D display is better for human operators to effectively judge depth if the task requires frequent use of focused attention.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.582-584
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• 2006

This paper describes a monocular PSD-based motion capture sensor to employ with commercial video game systems such as Microsoft's XBOX and Sony's Playstation II. The system compact, low-cost, and only requires a one-time calibration at the factory. The system includes a PSD(Position Sensitive Detector) and active infrared (IR) LED markers that are placed on the object to be tracked. The PSD sensor is placed in the focal plane of a wide-angle lens. The micro-controller calculates the 3D position of the markers using only the measured intensity and 2D position on the PSD. A series of experiments were performed to evaluate the performance of our prototype system. From the experimental results we see that the proposed system's compact size, low-cost, ease of installation, and high frame rates are suitable for high speed motion tracking in games.

• 대한전자공학회논문지SP
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• 제41권6호
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• pp.187-193
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• 2004

본 논문에서는 무한원점의 특성과 단일 비젼 시스템을 이용하여 자율 주행을 위한 GPS 위치 데이터 보정법을 제안한다. 실제 도로를 약 60 km의 거리를 주행하며 제안한 방법에 적용한 주행실험 결과를 제시하였다. 제안하는 방법은 직선도로의 환경에서 GPS 위치 오차론 최소 약 53% 이상 감소시켰고, 거리로는 0.5m 이내로 추정되었다. 그러나 곡선도로와 직선이 아닌 산악도로 등의 도로환경에서 정확도를 판별하기 어려운 관계로 직선도로에서의 오차만을 제시하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.1025-1026
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• 2008

This paper describes a monocular PSD-based motion capture sensor to employ with commercial video game systems such as Microsoft's XBOX and Sony's Playstation II. The system includes a PSD(Position Sensitive Detector) and active infrared (IR) LED markers that are placed on the object to be tracked. The micro-controller calculates the 3D position of the markers using only the measured intensity and the 2D position on the PSD. A series of experiments were performed to evaluate the performance of our prototype system. From the experimental results we see that the proposed system has the advantages of the compact size, the low cost, the easy installation, and the high frame rates to be suitable for high speed motion tracking in games.