The Research of Phase Method of Laser Ranging Measurement System

2012 ◽  
Vol 479-481 ◽  
pp. 632-635 ◽  
Author(s):  
Jing Huang ◽  
Bao Quan Dong
Keyword(s):  
Measurement System ◽  
Continuous Wave ◽  
Phase Variation ◽  
Frequency Measurement ◽  
Phase Method ◽  
Laser Ranging ◽  
Time Interval ◽  
Overall Design ◽  
Phase Discrimination ◽  
The Difference

The phase method of laser ranging modulates laser by using a continuous wave, calculating the time interval indirectly through the phase variation of the modulation wave when it propagates between the measured targets, and make out the measured distance. This paper uses the principle of phase method of laser ranging, proposes the overall design scheme of phase method of laser measurement system which achieves the distance measurement by using methods of the difference frequency measurement and digital phase discrimination as well as the microcontroller. It also analysis the system possible errors from many aspects, puts forward the appropriate measures to improve the accuracy of the measurement.

High speed and high precision time-interval measurement system in pulsed laser ranging

2015 ◽  
Vol 30 (1) ◽  
pp. 83-88 ◽  
Author(s):  
岱钦 DAI Qin ◽  
毛有明 MAO You-ming ◽  
吴凯旋 WU Kai-xuan ◽  
吴杰 WU Jie ◽  
李业秋 LI Ye-qiu
Keyword(s):  
High Precision ◽  
Measurement System ◽  
High Speed ◽  
Pulsed Laser ◽  
Laser Ranging ◽  
Time Interval ◽  
Interval Measurement ◽  
Precision Time ◽  
Time Interval Measurement

scholarly journals Vital Signal Detection Using Multi-Radar for Reductions in Body Movement Effects

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7398
Author(s):  
Ah-Jung Jang ◽  
In-Seong Lee ◽  
Jong-Ryul Yang
Keyword(s):  
Signal Detection ◽  
Continuous Wave ◽  
Signal To Noise Ratio ◽  
Body Movement ◽  
Phase Variation ◽  
Maximum Velocity ◽  
The Body ◽  
Wave Radar ◽  
The Difference ◽  
Correlated Signals

Vital signal detection using multiple radars is proposed to reduce the signal degradation from a subject’s body movement. The phase variation in the transceiving signals of continuous-wave radar due to respiration and heartbeat is generated by the body surface movement of the organs monitored in the line-of-sight (LOS) of the radar. The body movement signals obtained by two adjacent radars can be assumed to be the same over a certain distance. However, the vital signals are different in each radar, and each radar has a different LOS because of the asymmetric movement of lungs and heart. The proposed method uses two adjacent radars with different LOS to obtain correlated signals that reinforce the difference in the asymmetrical movement of the organs. The correlated signals can improve the signal-to-noise ratio in vital signal detection because of a reduction in the body movement effect. Two radars at different frequencies in the 5.8 GHz band are implemented to reduce direct signal coupling. Measurement results using the radars arranged at angles of 30°, 45°, and 60° showed that the proposed method can detect the vital signals with a mean accuracy of 97.8% for the subject moving at a maximum velocity of 53.4 mm/s.

CW (Continuous Wave) Measurement System. Operating Manual

1982 ◽  
Author(s):  
J. E. Bridge ◽  
IV. Burns ◽  
Gagliano J. ◽  
Reinman G. A. ◽  
R. B.
Keyword(s):  
Measurement System ◽  
Continuous Wave ◽  
Wave Measurement ◽  
System Operating

scholarly journals A scoping review of chronotype and temporal patterns of eating of adults: Tools used, findings, and future directions

2021 ◽  
pp. 1-51
Author(s):  
Yan Yin Phoi ◽  
Michelle Rogers ◽  
Maxine P. Bonham ◽  
Jillian Dorrian ◽  
Alison M. Coates
Keyword(s):  
Energy Intake ◽  
Scoping Review ◽  
Assessment Tool ◽  
Temporal Patterns ◽  
Time Interval ◽  
Dark Cycle ◽  
Future Directions ◽  
Meal Skipping ◽  
Optimal Health ◽  
The Difference

Abstract Circadian rhythms, metabolic processes, and dietary intake are inextricably linked. Timing of food intake is a modifiable temporal cue for the circadian system and may be influenced by numerous factors, including individual chronotype—an indicator of an individual’s circadian rhythm in relation to the light-dark cycle. This scoping review examines temporal patterns of eating across chronotypes and assesses tools that have been used to collect data on temporal patterns of eating and chronotype. A systematic search identified thirty-six studies in which aspects of temporal patterns of eating including meal timings; meal skipping; energy distribution across the day; meal frequency; time interval between meals, or meals and wake/sleep times; midpoint of food/energy intake; meal regularity; and duration of eating window were presented in relation to chronotype. Findings indicate that compared to morning chronotypes, evening chronotypes tend to skip meals more frequently, have later mealtimes, and distribute greater energy intake towards later times of the day. More studies should explore the difference in meal regularity and duration of eating window amongst chronotypes. Currently, tools used in collecting data on chronotype and temporal patterns of eating are varied, limiting the direct comparison of findings between studies. Development of a standardised assessment tool will allow future studies to confidently compare findings to inform the development and assessment of guidelines that provide recommendations on temporal patterns of eating for optimal health.

scholarly journals Two maize cultivars of contrasting leaf size show different leaf elongation rates with identical patterns of extension dynamics and coordination

AoB Plants ◽  
2021 ◽  
Author(s):  
Tiphaine Vidal ◽  
Hafssa Aissaoui ◽  
Sabrina Rehali ◽  
Bruno Andrieu
Keyword(s):  
Genotypic Variation ◽  
Leaf Size ◽  
High Rate ◽  
Time Interval ◽  
Extension Rate ◽  
Leaf Production ◽  
Maize Cultivars ◽  
Plant Environment ◽  
The Difference ◽  
Leaf Extension

Abstract Simulating leaf development from initiation to maturity opens new possibilities to model plant–environment interactions and the plasticity of plant architecture. This study analyses the dynamics of leaf production and extension along a maize (Zea mays) shoot to assess important modelling choices. Maize plants from two cultivars originating from the same inbred line, yet differing in the length of mature leaves were used in this study. We characterised the dynamics of the blade and sheath lengths of all phytomers by dissecting plants every 2–3 days. We analysed how differences in leaf size were built up and we examined the coordination between the emergence of organs and phases of their extension. Leaf extension rates were higher in the cultivar with longer leaves than in the cultivar with shorter leaves; no differences were found in other aspects. We found that (i) first post-embryonic leaves were initiated at a markedly higher rate than upper leaves; (ii) below ear position, sheaths were initiated at a time intermediate between tip emergence and appearance, while above the ear position, sheaths were initiated at a high rate, such that the time interval between the blade and sheath initiations decreased for these leaves; and (iii) ear position also marked a change in the correlation in size between successive phytomers with little correlation of size between upper and lower leaves. Our results identified leaf extension rate as the reason for the difference in size between the two cultivars. The two cultivars shared the same pattern for the timing of initiation events, which was more complex than previously thought. The differences described here may explain some inaccuracies reported in functional-structural plant models. We speculate that genotypic variation in behaviour for leaf and sheath initiation exists, which has been little documented in former studies.

Synchronization in Dual Delay Line SAW Sensors

2004 ◽  
Author(s):  
Duck-Bong Seo ◽  
Z. C. Feng
Keyword(s):  
Delay Line ◽  
Phase Measurement ◽  
Surface Adsorption ◽  
Propagation Speed ◽  
Frequency Measurement ◽  
Frequency Change ◽  
Averaged Equations ◽  
Excited Oscillation ◽  
The Difference ◽  
Delay Differential

Surface acoustic wave (SAW) sensors are self-excited oscillators. Self-excitation is a consequence of the finite amount of delay in the circuit. The oscillation frequency is affected by the wave propagation speed which further depends on surface adsorption. Therefore, measurement on the surface adsorption is done by measuring the frequency change of the self-excited oscillation. In dual delay line oscillators the difference between the surface physical conditions is reflected through the difference in oscillation frequencies. Delay differential equations are used to model the sensor. Bifurcation analysis of the averaged equations indicates the presence of synchronization. The occurrence of synchronization is further demonstrated through numerical simulations. Synchronization makes the frequency measurement irrelevant. We propose phase measurement as an alternative in the presence of strong coupling between the two oscillators.

Design of Measurement System of the Center of Gravity

2013 ◽  
Vol 706-708 ◽  
pp. 733-736
Author(s):  
Fang Li
Keyword(s):  
Measurement System ◽  
Center Of Gravity ◽  
Actual Position ◽  
Ideal Position ◽  
The Future ◽  
The Difference ◽  
New System ◽  
The Ideal

It is very difficult to confirm the position of the center of gravity irregular object.This paper introduces a new system,which can be used in measuring and adjusting of the center of gravity.The irregular object was put on the support parts,then the center of gravity was given.When the actual position was compared with the ideal position,the difference was given. Until actual position and ideal position were coincided,the machining was continuing. Matlab was programmed in this measure system. It will be applied widely in the future.

LONG‐TIME RESPONSE PREDICTED BY EXACT ELASTIC RAY THEORY

Geophysics ◽  
1965 ◽  
Vol 30 (3) ◽  
pp. 363-368 ◽  
Author(s):  
T. W. Spencer
Keyword(s):  
Formal Solution ◽  
Intermediate Stage ◽  
Time Limit ◽  
Time Interval ◽  
Individual Response ◽  
Axially Symmetric ◽  
Long Time ◽  
The Difference ◽  
The Individual ◽  
Significant Figures

The formal solution for an axially symmetric radiation field in a multilayered, elastic system can be expanded in an infinite series. Each term in the series is associated with a particular raypath. It is shown that in the long‐time limit the individual response functions produced by a step input in particle velocity are given by polynomials in odd powers of the time. For rays which suffer m reflections, the degree of the polynomials is 2m+1. The total response is obtained by summing all rays which contribute in a specified time interval. When the rays are selected indiscriminately, the difference between the magnitude of the partial sum at an intermediate stage of computation and the magnitude of the correct total sum may be greater than the number of significant figures carried by the computer. A prescription is stated for arranging the rays into groups. Each group response function varies linearly in the long‐time limit and goes to zero when convolved with a physically realizable source function.

Synchronization of cardiac-related discharges of sympathetic nerves with inputs from widely separated spinal segments

1995 ◽  
Vol 268 (6) ◽  
pp. R1472-R1483 ◽  
Author(s):  
G. L. Gebber ◽  
S. Zhong ◽  
S. M. Barman
Keyword(s):  
Phase Angle ◽  
Cervical Spinal Cord ◽  
Sympathetic Nerves ◽  
Time Interval ◽  
Renal Nerve ◽  
Cardiac Nerve ◽  
Spinal Segments ◽  
The Difference ◽  
Decerebrate Cats ◽  
Inferior Cardiac Nerve

We used phase spectral analysis to study the relationships between the cardiac-related discharges of pairs of postganglionic sympathetic nerves in urethan-anesthetized or decerebrate cats. Phase angle when converted to a time interval should equal the difference in conduction times from the brain to the nerves (i.e., transportation lag) if their cardiac-related discharges have a common central source. Transportation lag was estimated as the difference in the onset latencies of activation of the nerves by electrical stimulation of the medulla or cervical spinal cord. The phase angle for the cardiac-related discharges of two nerves was not always equivalent in time to the transportation lag. For example, in some cases the cardiac-related discharges of the renal nerve were coincident with or led those of the inferior cardiac nerve. In contrast, the electrically evoked responses of the renal nerve lagged those of the inferior cardiac nerve by > or = 32 ms. These observations are consistent with a model of multiple and dynamically coupled brain stem generators of the cardiac-related rhythm, each controlling a different sympathetic nerve or exerting nonuniform influences on different portions of the spinal sympathetic outflow.

scholarly journals The effect of diminazene aceturate on cholinesterase activity in dogs with canine babesiosis

1997 ◽  
Vol 68 (4) ◽  
Author(s):  
R.J. Milner ◽  
F. Reyers ◽  
J.H. Taylor ◽  
J.S. Van den Berg
Keyword(s):  
Treatment Group ◽  
Underlying Mechanism ◽  
Time Interval ◽  
Control Groups ◽  
Canine Babesiosis ◽  
Diminazene Aceturate ◽  
Time Intervals ◽  
Significant Depression ◽  
The Difference ◽  
And Control

A clinical trial was designed to evaluate the effects of diminazene aceturate and its stabiliser antipyrine on serum pseudocholinesterase (PChE) and red blood cell acetylcholinesterase (RBC AChE) in dogs with babesiosis. The trial was conducted on naturally occurring, uncomplicated cases of babesiosis (n = 20) that were randomly allocated to groups receiving a standard therapeutic dose of diminazene aceturate with antipyrine stabiliser (n = 10) or antipyrine alone (n = 10). Blood was drawn immediately before and every 15 minutes for 1 hour after treatment. Plasma PChE showed a 4 % decrease between 0 and 60 min within the treatment group (p < 0.05). No statistically significant differences were found between the treatment and control groups at any of the time intervals for PChE. There was an increase in RBC AChE activity at 15 min in the treatment group (p < 0.05). No significant differences were found between the treatment and control groups at any time interval for RBC AChE. In view of the difference in PChE, samples from additional, new cases (n = 10) of canine babesiosis were collected to identify the affect of the drug over 12 hours. No significant depression was identified over this time interval. The results suggests that the underlying mechanism in producing side-effects, when they do occur, is unlikely to be through cholinesterase depression.

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