A Proof of the Reflective Property of the Parabola

Author(s):  
Howard Sporn
Keyword(s):  
1980 ◽  
Vol 87 (4) ◽  
pp. 294
Author(s):  
James H. Foster ◽  
Jean J. Pedersen
Keyword(s):  

1969 ◽  
Vol 25 (5) ◽  
pp. 241-247
Author(s):  
Hiroaki Nakazato ◽  
Masanori Meguro

2017 ◽  
Vol 9 (4) ◽  
pp. 583-585 ◽  
Author(s):  
Pengde Han ◽  
Yiqing Zhu ◽  
Tianjing Li ◽  
Qingle Shi ◽  
Qitu Zhang

2014 ◽  
Vol 87 (4) ◽  
pp. 276-279 ◽  
Author(s):  
Stephan Berendonk
Keyword(s):  

1987 ◽  
Vol 94 (7) ◽  
pp. 667
Author(s):  
Robert C. Williams
Keyword(s):  

1971 ◽  
Vol 69 (1) ◽  
pp. 201-215 ◽  
Author(s):  
Jon T. Schnute

1. Introduction. The historical basis for the work in this paper lies in a remarkable fact discovered by Dean in 1948. He found that time-periodic surface waves in an ideal fluid experience no reflexion when they encounter normally a fixed, submerged, right-circular cylinder. We might reasonably ask if a similar non-reflective property carries over to different geometrical configurations of submerged objects, for example, two or more cylinders. This question motivates the investigation which follows.


2014 ◽  
Vol 614 ◽  
pp. 79-83
Author(s):  
Wen Yan Zhang ◽  
Ling Yun Hao ◽  
Chun Hua Lu ◽  
Chun Hua Feng ◽  
Qin Lin ◽  
...  

Conical arrays of polydimethyl siloxane were fabricated by duplicating the morphology of needle tips. The prepared cones have periodic order and regular shape, with the bottom diameter of about 80 μm and height of about 250 μm. Due to their special structure, the conical arrays of polydimethyl siloxane exhibited broadband anti-reflective property. Compared with smooth surface, they could reduce the reflection of incident electromagnetic wave at ultraviolet, visible and near-infrared region. The specular reflectance was lower than 0.75% in the range of 250-2600 nm. The prepared PDMS cones have potential to be applied for antireflective devices. The method was simple for mass production of PDMS cones at low cost.


2021 ◽  
Vol 29 (2) ◽  
Author(s):  
Shanyu Chua ◽  
Chee Chin Lim ◽  
Swee Kheng Eng ◽  
Yen Fook Chong ◽  
Chiun Tai Loh

Phase-shifting fringe projection methods have been developed for three-dimensional scanning (Zuo et al., 2018). However, the 3-Dimensional (3D) scanning of objects with a high dynamic reflectivity range based on structured light is a challenging task to achieve (Feng et al., 2018). The incorrect intensities captured will cause phase and measurement errors. Thus, this paper proposes a method that improves the current High Dynamic Range (HDR) (Jiang et al., 2016)) method to increase the dynamic range. The camera and projector have 3 channels, red, green, and blue, which can absorb and project these lights independently. This paper proposes a method that makes use of this by controlling the intensity of each projected for the camera. Each image can be split into 3 channels and provide 3 images which contain different intensities, then it will be used to compute the 3D information. In general, this is done by controlling the projection of red, green and blue (RGB) channel and apply the Jiang’s algorithm (Jiang et al., 2016). The results are compared and analysed with current HDR (Jiang’s method) and the regular three-step phase-shifting methods. From the experimental results, it has shown that our proposed method outperforms the current HDR and the regular three-step phase-shifting methods. Specifically, the proposed method manages to increase the dynamic range of the reflective property of objects. Additionally, our proposed method has also significantly reduced the times of 3D object measurements.


Sign in / Sign up

Export Citation Format

Share Document