scholarly journals The Behavior of Midsets When Repeatedly Taking the Midset of Two Lines inℓ1Geometry

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Joshua M. Fitzhugh ◽  
David L. Farnsworth
Keyword(s):  
Angle Measurement ◽  
Minkowski Geometries

We study the outcome of taking midsets of two lines inℓ1geometry. We establish the algorithm for repeatedly finding these midsets and characterize the limiting midsets. We discuss the issue of angle measurement in Minkowski geometries, especially with respect to the limiting midsets.

One-shot Multi-angle Measurement Device for Evaluating the Sparkle Impression

2020 ◽  
Vol 2020 (5) ◽  
pp. 60401-1-60401-8
Author(s):  
Shuhei Watanabe
Keyword(s):  
Spatial Frequency ◽  
Product Design ◽  
Angle Measurement ◽  
Observation Angle ◽  
Light Sources ◽  
Quantification Method ◽  
Material Appearance ◽  
Subjective Score ◽  
Measurement Devices ◽  
Rotation Stage

The quantification of material appearance is important in product design. In particular, the sparkle impression of metallic paint used mainly for automobiles varies with the observation angle. Although several evaluation methods and multi-angle measurement devices have been proposed for the impression, it is necessary to add more light sources or cameras to the devices to increase the number of evaluation angles. The present study constructed a device that evaluates the multi-angle sparkle impression in one shot and developed a method for quantifying the impression. The device comprises a line spectral camera, light source, and motorized rotation stage. The quantification method is based on spatial frequency characteristics. It was confirmed that the evaluation value obtained from the image recorded by the constructed device correlates closely with a subjective score. Furthermore, the evaluation value is significantly correlated with that obtained using a commercially available evaluation device.

Automated dihedral angle measurement in liquid phase sintered alloys

2004 ◽  
Vol 95 (1) ◽  
pp. 3-7 ◽  
Author(s):  
P. Chhillar ◽  
S. Sangal ◽  
A. Upadhyaya
Keyword(s):  
Liquid Phase ◽  
Dihedral Angle ◽  
Angle Measurement ◽  
Sintered Alloys

Investigation of the Accuracy of Reference Instruments for Measuring Vertical Angles by Reference Method of Their Calibration

2020 ◽  
pp. 3-14
Author(s):  
O. M. Samoylenko ◽  
O. V. Adamenko ◽  
B. P. Kukareka
Keyword(s):  
Horizontal Plane ◽  
Opposite Sign ◽  
Reference Method ◽  
Angle Measurement ◽  
Measurement Standard ◽  
Vertical Angle ◽  
Measurement Standards ◽  
Measurement Results ◽  
Electronic Measurement ◽  
Systematic Biases

Reference method for simultaneous calibration of the three and more measurement standards for vertical angle measurement is developed. This method can to use for obtaining the systematic biases of the vertical angles measurements for each of the measuring standards relative of the horizontal plain was averaged from measurement results in time their calibration or comparison. For realization of the reference method was developed the autocollimationel electronic measurement standard for the automatization measurement of the vertical angles SeaLineZero_Standard™ (SLZ_S™). Summary standard deviation (k=1) of the vertical angle measurement relative the horizontal plane, from the results of their calibration by reference method, is not more 0,07ʺ…0,15ʺ. This result was obtained without the use the systematic biases, for each measurement standards, as measurements corrections (with opposite sign). The measuring standards, that were developed and researched, are necessary for obtaining the systematic biases of the vertical angle measurement for total stations and theodolites, that have the normed standard error 0,5ʺ and 1ʺ, when these instruments are calibrating.

Sparse Representation Based Dielectric Loss Angle Measurement

2015 ◽  
Vol 9 (1) ◽  
pp. 566-570
Author(s):  
Zhang Ji ◽  
Jianfeng Zheng
Keyword(s):  
Dielectric Loss ◽  
Power Systems ◽  
Sparse Representation ◽  
Precise Measurement ◽  
Angle Measurement ◽  
Measuring Error ◽  
Loss Angle ◽  
Analysis Method ◽  
Electric Capacity ◽  
Dielectric Loss Angle

Precise measurement of dielectric loss angle is very important for electric capacity equipment in recent power systems. When signal-to-noise is low and fundamental frequency is fluctuating, aiming at the measuring error of dielectric loss angle based on some recent Fourier transform and wavelet transform harmonics analysis method, we propose a novel algorithm based on sparse representation, and improved it to be more flexible for signal sampling. Comparison experiments describe the advantages of our method.

scholarly journals Validity and reliability of smartphone applications for measurement of hip rotation, compared with three‐dimensional motion analysis

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Phob Ganokroj ◽  
Nuchanun Sompornpanich ◽  
Pichitpol Kerdsomnuek ◽  
Bavornrat Vanadurongwan ◽  
Pisit Lertwanich
Keyword(s):  
Internal Rotation ◽  
Motion Analysis ◽  
Supine Position ◽  
External Rotation ◽  
Three Dimensional ◽  
Angle Measurement ◽  
Smartphone Applications ◽  
Rater Reliability ◽  
Link Type ◽  
Hip Rotation

Abstract Background Measurement of hip rotation is a crucial clinical parameter for the identification of hip problems and the monitoring of symptoms. The objective of this study was to determine whether the use of two smartphone applications is valid and reliable for the measurement of hip rotation. Methods An experimental, cross-sectional study was undertaken to assess passive hip internal and external rotation in three positions by two examiners. The hip rotational angles were measured by a smartphone clinometer application in the sitting and prone positions, and by a smartphone compass application in the supine position; their results were compared with those of the standard, three-dimensional, motion analysis system. The validities and inter-rater and intra-rater reliabilities of the smartphone applications were evaluated. Results The study involved 24 participants. The validities were good to excellent for the internal rotation angles in all positions (ICC 0.81–0.94), good for the external rotation angles in the prone position (ICC 0.79), and fair for the sitting and supine positions (ICC 0.70–0.73). The measurement of the hip internal rotation in the supine position had the highest ICC value of 0.94 (0.91, 0.96). The two smartphone applications showed good-to-excellent intra-rater reliability, but good-to-excellent inter-rater reliability for only three of the six positions (two other positions had fair reliability, while one position demonstrated poor reliability). Conclusions The two smartphone applications have good-to-excellent validity and intra-rater reliability, but only fair-to-good inter-rater reliability for the measurement of the hip rotational angle. The most valid hip rotational position in this study was the supine IR angle measurement, while the lowest validity was the ER angle measurement in the sitting position. The smartphone application is one of the practical measurements in hip rotational angles. Trial registration Number 20181022003 at the Thai Clinical Trials Registry (http://www.clinicaltrials.in.th) which was retrospectively registered at 2018-10-18 15:30:29.

scholarly journals An Optical Frequency Domain Angle Measurement Method Based on Second Harmonic Generation

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 670
Author(s):  
Wijayanti Dwi Astuti ◽  
Hiraku Matsukuma ◽  
Masaru Nakao ◽  
Kuangyi Li ◽  
Yuki Shimizu ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Second Harmonic Generation ◽  
Frequency Domain ◽  
Harmonic Generation ◽  
Measurement Method ◽  
Second Harmonic ◽  
Angle Measurement ◽  
Laser Source ◽  
Optical Frequency ◽  
Measurable Range

This paper proposes a new optical angle measurement method in the optical frequency domain based on second harmonic generation with a mode-locked femtosecond laser source by making use of the unique characteristic of the high peak power and wide spectral range of the femtosecond laser pulses. To get a wide measurable range of angle measurement, a theoretical calculation for several nonlinear optical crystals is performed. As a result, LiNbO3 crystal is employed in the proposed method. In the experiment, the validity of the use of a parabolic mirror is also demonstrated, where the chromatic aberration of the focusing beam caused the localization of second harmonic generation in our previous research. Moreover, an experimental demonstration is also carried out for the proposed angle measurement method. The measurable range of 10,000 arc-seconds is achieved.

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