Optical fiber fault locator by the step frequency method

1987 ◽  
Vol 26 (3) ◽  
pp. 440 ◽  
Author(s):  
Junichi Nakayama ◽  
Keigo Iizuka ◽  
John Nielsen
Keyword(s):  
Optical Fiber ◽  
Step Frequency ◽  
Frequency Method

scholarly journals Two-step frequency conversion for connecting distant quantum memories by transmission through an optical fiber

2018 ◽  
Vol 57 (6) ◽  
pp. 062801 ◽  
Author(s):  
Shuhei Tamura ◽  
Kohei Ikeda ◽  
Kotaro Okamura ◽  
Kazumichi Yoshii ◽  
Feng-Lei Hong ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Frequency Conversion ◽  
Step Frequency

scholarly journals Natural Frequency Method: estimating the preferred walking speed of Tyrannosaurus rex based on tail natural frequency

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Pasha A. van Bijlert ◽  
A. J. ‘Knoek’ van Soest ◽  
Anne S. Schulp
Keyword(s):  
Energy Storage ◽  
Natural Frequency ◽  
Elastic Energy ◽  
Walking Speed ◽  
Natural Frequencies ◽  
Body Parts ◽  
Step Frequency ◽  
Frequency Method ◽  
Cost Of Transport ◽  
Moment Arms

Locomotor energetics are an important determinant of an animal's ecological niche. It is commonly assumed that animals minimize locomotor energy expenditure by selecting gait kinematics tuned to the natural frequencies of relevant body parts. We demonstrate that this allows estimation of the preferred step frequency and walking speed of Tyrannosaurus rex , using an approach we introduce as the Natural Frequency Method. Although the tail of bipedal dinosaurs was actively involved in walking, it was suspended passively by the caudal interspinous ligaments. These allowed for elastic energy storage, thereby reducing the metabolic cost of transport. In order for elastic energy storage to be high, step and natural frequencies would have to be matched. Using a 3D morphological reconstruction and a spring-suspended biomechanical model, we determined the tail natural frequency of T. rex (0.66 s −1 , range 0.41–0.84), and the corresponding walking speed (1.28 m s −1 , range 0.80–1.64), which we argue to be a good indicator of preferred walking speed (PWS). The walking speeds found here are lower than earlier estimations for large theropods, but agree quite closely with PWS of a diverse group of extant animals. The results are most sensitive to uncertainties regarding ligament moment arms, vertebral kinematics and ligament composition. However, our model formulation and method for estimation of walking speed are unaffected by assumptions regarding muscularity, and therefore offer an independent line of evidence within the field of dinosaur locomotion.

Bending loss formulas for step-index optical fiber and their applicable regions

1981 ◽  
Vol 64 (10) ◽  
pp. 95-103
Author(s):  
Kiyonobu Kusano ◽  
Shigeo Nishida
Keyword(s):  
Optical Fiber ◽  
Step Index ◽  
Bending Loss

Heating and Burning of Optical Fibers and Cables by Light Scattered from Bubble Train Formed by Optical Fiber Fuse

2012 ◽  
Vol E95.B (8) ◽  
pp. 2638-2641 ◽  
Author(s):  
Makoto YAMADA ◽  
Akisumi TOMOE ◽  
Takahiro KINOSHITA ◽  
Osanori KOYAMA ◽  
Yutaka KATUYAMA ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fibers
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