Maximum Optical Paths

Nature ◽  
1934 ◽  
Vol 133 (3370) ◽  
pp. 830-831 ◽  
Author(s):  
T. SMITH
Keyword(s):  
2018 ◽  
Vol 32 (4) ◽  
pp. 182-190 ◽  
Author(s):  
Kenta Matsumura ◽  
Koichi Shimizu ◽  
Peter Rolfe ◽  
Masanori Kakimoto ◽  
Takehiro Yamakoshi

Abstract. Pulse volume (PV) and its related measures, such as modified normalized pulse volume (mNPV), direct-current component (DC), and pulse rate (PR), derived from the finger-photoplethysmogram (FPPG), are useful psychophysiological measures. Although considerable uncertainties exist in finger-photoplethysmography, little is known about the extent of the adverse effects on the measures. In this study, we therefore examined the inter-method reliability of each index across sensor positions and light intensities, which are major disturbance factors of FPPG. From the tips of the index fingers of 12 participants in a resting state, three simultaneous FPPGs having overlapping optical paths were recorded, with their light intensity being changed in three steps. The analysis revealed that the minimum values of three coefficients of Cronbach’s α for ln PV, ln mNPV, ln DC, and PR across positions were .948, .850, .922, and 1.000, respectively, and that those across intensities were .774, .985, .485, and .998, respectively. These findings suggest that ln mNPV and PR can be used for psychophysiological studies irrespective of minor differences in sensor attachment positions and light source intensity, whereas and ln DC can also be used for such studies but under the condition of light intensity being fixed.


Author(s):  
J.E. López de Vergara ◽  
M. Ruiz ◽  
L. Gifre ◽  
M. Ruiz ◽  
L. Vaquero ◽  
...  

2005 ◽  
Vol 333 (3) ◽  
pp. 401-413 ◽  
Author(s):  
Michele Flammini ◽  
Alfredo Navarra ◽  
Andrzej Proskurowski
Keyword(s):  

2006 ◽  
Author(s):  
Olga K. Voitsekhovskaya ◽  
Victor N. Cherepanov ◽  
Alexander Yu. Zaprjagaev ◽  
Zlata A. Voitsekhovskaya

Author(s):  
Henning Bulow ◽  
Jozef Dubovan ◽  
Reinhold Herschel
Keyword(s):  

Author(s):  
Wei Sha ◽  
Chao Fang ◽  
Yu Niu ◽  

As an important part of laser interferometry system, optical bench is one of the core technologies for the detection of spaceborne gravitational waves. As the first step of the space Taiji program, Taiji-1 provides the measurement accuracy of laser interferometry system better than 100 pm/Hz[Formula: see text](@10 mHz–1 Hz). Taiji-1 is required to be able to track the motion of test mass in inertial sensor. According to the requirements, four interfering optical paths were designed. By adopting an integrated satellite design and selecting the optical and mechanical materials with low linear expansion coefficient, the high stability of optical path was achieved. By using the DOE method, the alignment errors (position/attitude) of four optical paths were all reduced to below 50 [Formula: see text]m/100 [Formula: see text]rad. In the performance test, the accuracy of laser interferometry system was better than 100 pm/Hz[Formula: see text](@10 mHz–1 Hz), and the modulation signal of inertial sensor was successfully detected. The results show that all technical indexes of optical bench have met or exceeded the design requirements.


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