• 한국정보통신학회논문지
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• 제8권2호
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• pp.471-476
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• 2004

본 논문에서는 영상처리를 이용하여 온라인으로 교통표지판을 인식하는 비젼 시스템을 제안한다. 제안된 시스템은 넓은 두 개의 카메라, 즉 광각렌즈(wide-angle lends)와 망원렌즈(telephoto lends)를 장착하였고, 이미지처리 보드가 있는 PC로 구성되었다. 이 시스템은 색상, 자기, 형태 등과 같은 정보를 이용하여 광각이미지의 교통표지판을 추출한 다음, 보다 큰 이미지에서 정확한 표지판 후보영역을 추출하기 위해 망원렌즈에서 포착된 이미지를 이용하여 처리하였다. 실험결과로써 수동으로 촬영한 비디오 연속장면에서 포착한 영상을 시용하여 실험한 결과 속도표지판은 추출율 96.5%, 인식률 34.4% 그리고 안내표지판은 추출율 100%, 인식률 40%의 결과를 나타내었다. 또한 간단한 실행과정으로 빠른 인식률을 얻을 수 있었으며, 도로상에서의 실험으로 시스템의 효용성을 입증하였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.699-701
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• 2017

장거리 관측용 카메라의 일반적인 운용방법은 광각에서 표적에 대한 탐지를 하며, 망원으로 표적에 대한 인지/식별을 하게 된다. 탐지/인지거리 성능은 방산용 적외선카메라의 성능을 평가하는 중요한 항목이다. 탐지거리 성능이 증가하려면 카메라의 시야가 좁아져야 하고, 좁은 시야각으로 인하여 표적을 찾게 될 확률이 상대적으로 낮아지게 된다. 본 연구에서는 탐지거리 성능을 유지하면서 넓은 시야각을 제공하여 표적에 대한 탐색을 용이하게 할 수 있는 방안을 검토하였다. 그리고 M&S 및 최적화 설계를 통하여 시야 확장형 적외선카메라를 제작하고 시험한 결과를 정리하였다.

• Current Optics and Photonics
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• 제1권4호
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• pp.351-357
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• 2017

This paper proposes a LED bicycle headlamp with a wide viewing angle to help bicyclists see the front effectively and because of its high visibility to reduce the risks of accidents around intersections or blind spots. The wide viewing angle was determined to be $28^{\circ}$ because it can illuminate a 5 m wide area 10 m away. Therefore, the road conditions of the intersection can be observed with the bicycle handlebar tilted slightly to the left or right. The headlamp has a compact reflector with a width of 30 mm, height of 27 mm, and length of 17 mm. Owing to its size, a change in the position of a light source leads to severe changes in light distribution. Therefore, the tolerance of the source position was analyzed by a simulation. The tolerance was ${\pm}0.5mm$ at the X, Y and Z axes within a less centered aiming range of ${\pm}1^{\circ}$. Finally, the prototype of the bicycle headlamp was made and the light distribution was measured by an automotive headlamp light measurement system. The experimental results indicate that the headlamp illuminates a 5 m wide area with an edge light of 3.2 lx as well as meeting the K-mark regulation.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.348-351
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• 2008

We suggest a viewing angle control mode of liquid crystal display(LCD) with additive thermal controllable optical layer [TCOL], which composed of homeotropically or homogenously well aligned LC layer and patterned hating lines on a substrate. In this system, LCD modes with wide viewing angle characteristics can be used as a main panel.

• Journal of Korean Neurosurgical Society
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• 제64권4호
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• pp.552-561
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• 2021

Objective : To compare the anterior cervical discectomy and fusion (ACDF) and posterior cervical fusion (PCF) with wide facetectomy in the treatment of parallel-shaped bony foraminal stenosis (FS). Methods : Thirty-six patients underwent surgery due to one-or-two levels of parallel-shaped cervical FS. ACDF was performed in 16 patients, and PCF using CPS was performed in 20 patients. All patients were followed up at 1, 3, 6, and 12 months postoperatively. Standardized outcome measures such as Numeric rating scale (NRS) score for arm/neck pain and Neck disability index (NDI) were evaluated. Cervical radiographs were used to compare the C2-7 Cobb's angle, segmental angle, and fusion rates. Results : There was an improvement in NRS scores after both approaches for radicular arm pain (mean change -6.78 vs. -8.14, p=0.012), neck pain (mean change -1.67 vs. -4.36, p=0.038), and NDI score (-19.69 vs. -18.15, p=0.794). The segmental angle improvement was greater in the ACDF group than in the posterior group (9.4°±2.7° vs. 3.3°±5.1°, p=0.004). However, there was no significant difference in C2-7 Cobb angle between groups (16.2°±7.9° vs. 14.8°±8.5°, p=0.142). As a complication, dysphagia was observed in one case of the ACDF group. Conclusion : In the treatment of parallel-shaped bony FS up to two surgical levels, segmental angle improvement was more favorable in patients who underwent ACDF. However, PCF with wide facetectomy using CPS should be considered as an alternative treatment option in cases where the anterior approach is burdensome.

• Journal of Information Display
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• 제12권3호
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• pp.153-158
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• 2011

This study was conducted for the purpose of evaluating the impressions gained by the members of the audience who have seen contents in a dome theater, based on their seating positions. Dome Theater Gaia provided the environment where the contents for evaluation were to be presented, and enquete (survey) was used as the investigative method. The survey results showed that the presentation of wide-viewing-angle three-dimensional (3D) contents proved effective in enhancing the 3D effect and the presence in a dome theater. Moreover, the study results confirmed that in relation to the impression evaluation of the contents for different seating positions, the optimal seating position varied according to the presentation method of the 3D and 2D contents.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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• pp.629-632
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• 2003

This paper has been studied analysis and design of microstrip Rotman lens operating over wide band and wide steering angle by the contour integral method along with the segmentation method. All mutual coupling, internal reflections between ports with exponential taper are taken into account. Equally spaced ports are designed and realized which gives less amplitude ripple at array ports. The measured results of 12 input and 12 output lens show $\pm$1.8 dB insertion loss deviation over 6~18GHz wide frequency range and beam steering accuracy less than 1$^{\circ}$ over $\pm$53$^{\circ}$ angle and agrees well with the analysis results.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.510-514
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• 1994

This paper deals with an application of neural network to camera calibration with wide angle lens and 2-D range finding. Wide angle lens has an advantage of having wide view angles for mobile environment recognition ans robot eye in hand system. But, it has severe radial distortion. Multilayer neural network is used for the calibration of the camera considering lens distortion, and is trained it by error back-propagation method. MLP can map between camera image plane and plane the made by structured light. In experiments, Calibration of camers was executed with calibration chart which was printed by using laser printer with 300 d.p.i. resolution. High distortion lens, COSMICAR 4.2mm, was used to see whether the neural network could effectively calibrate camera distortion. 2-D range of several objects well be measured with laser range finding system composed of camera, frame grabber and laser structured light. The performance of 3-D range finding system was evaluated through experiments and analysis of the results.

• 한국전자파학회논문지
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• 제13권8호
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• pp.777-782
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• 2002

일반적인 시간 영역에서의 레이더 신호들은 표적의 관측각에 민감하게 변화한다. 따라서 대표적인 시간영역 레이더 신호인 1차원 range profile을 이용하여 구분실험을 하는 경우에 있어서 central moments와 PCA를 결합하여 먼저 특성벡터를 추출한 후 clustering 기법에 기반한 subclass concept을 사용하는 구분기를 사용하여 넓은 관측각에서의 표적인식 성능을 향상시킨 결과들을 보여준다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.299-301
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• 1996

Since a standard lens has small sight angle, a fish-eye lens can be used in order to obtain wide sight angle for the robot vision system. In spite of the advantage, the image through the lens has variable resolution; the central information of the lens is of high resolution, but the peripheral information is of low resolution. Owing to this difference of resolution, the variable resolution image should be transformed to a uniform resolution image in order to determine the positions of the objects in the image. In this work, the correction method for the distorted image is presented and the performance is analyzed. Furthermore, the camera with a fish eye lens can be used to determine the real world coordinates. The performance is shown through experiments.