Approximate Straight-Line Motion From Simple Spatial Mechanisms

1976 ◽  
Vol 98 (4) ◽  
pp. 1250-1254
Author(s):  
M. W. Reid ◽  
K. H. Hunt ◽  
H. Nolle
Keyword(s):  
Simple Form ◽  
Circular Motion ◽  
Spatial Mechanisms ◽  
Straight Line

A simple form of spin-surface is investigated and it is shown how, via this surface, spatial mechanisms may readily be synthesized to give twelve-point straight line motion or twelve-point circular motion. The spatial mechanisms are obtained by adding links to plane four-bar linkages.

Kinematic Analysis of Spatial Mechanisms Via Successive Screw Displacements

1975 ◽  
Vol 97 (2) ◽  
pp. 739-747 ◽  
Author(s):  
Dilip Kohli ◽  
A. H. Soni
Keyword(s):  
Closed Form ◽  
Kinematic Analysis ◽  
Closed Loop ◽  
Displacement Velocity ◽  
Spatial Mechanism ◽  
Spatial Mechanisms ◽  
Straight Line ◽  
Unified Method

A new, unified method is proposed and demonstrated to conduct kinematic analysis of spatial mechanisms involving revolute, cylindrical, prismatic, helical and spherical pairs. The paper derives the equations for the successive screw displacements, and the equations for pair constraints. Using these equations, closed-form relationships for displacement, velocity and acceleration of single or multi-loop spatial mechanisms are obtained by (1) breaking the mechanism at a critical joint (2) unfolding the mechanism along a straight line (3) providing successive screw displacement at each joint and (4) reassembling the mechanism to form a closed loop. The application of this newly developed approach is demonstrated by considering an example of a two-loop spatial mechanism with revolute, cylindrical and spherical pairs.

scholarly journals Hypothes About The Motion Of Photon In The Space

2019 ◽  
Author(s):  
jinjun Cheng
Keyword(s):  
Plane Motion ◽  
Circular Motion ◽  
Movement Speed ◽  
Linear Motion ◽  
Straight Line ◽  
Space Motion ◽  
Energy Formula ◽  
Photon Frequency ◽  
Simple Logic ◽  
Planck Energy

This paper attempts to photons and known according to the axiom of the definition, using simple logic, reasoning about propositions of photons and its movement in space.The light is by the space motion photon component. The space motion photon has the energy and the quality. Photon in space along straight line direction movement speed identically equal in c. A photon moves in space with uniform helical motion, which is a combination of uniform circular motion and uniform linear motion in which the speed of the linear motion and the linear speed of the circular motion are always equal to c. Photon's Planck energy formula E=hv=2π v, is the approximate Planck constant, which is the angular momentum of photons moving along the circumference plane direction mcr, r is the photon along the circumference plane motion radius; v is photon each second completes the circular motion by link speed c the number of times c/2πr, also is the photon frequency. By replacing the mcr and c/2πr with the Planck energy formula, may obtain Einstein mass energy formula E=mc2.The greater its mass and energy, the smaller the radius of its circular motion, the higher its frequency, and the shorter its wavelength. The lower its mass and energy, the greater the radius of its circular motion, the lower its frequency, and the longer its wavelength. The uncertainty principle is essentially caused by our misunderstanding of the motion of light. The existence and motion of light can be determined.

Research on Localization Principle and Method for Multistation Range-only Target Tracking System

2013 ◽  
Vol 380-384 ◽  
pp. 1091-1095
Author(s):  
Lu Wang ◽  
Zhong Liu
Keyword(s):  
Target Tracking ◽  
Simple Form ◽  
Tracking System ◽  
High Accuracy ◽  
Target Localization ◽  
Localization Principle ◽  
Straight Line ◽  
Simulation Results ◽  
Underwater Target ◽  
Line Movement

Observable condition for multistation range-only system was analyzed according to the characteristics of underwater target localization in the conditions of network warfare. When the target is stationary or travels in straight-line movement, it is able to be observed by range-only system. The target localization parameters are estimated by least squares estimator algorithm, which has simple form and does not need initial values. Simulation results show that the algorithm has fast convergence speed, good stability and high accuracy.

Friction Damping of Circular Motion and Its Implications to Vibration Control

1991 ◽  
Vol 113 (2) ◽  
pp. 225-229 ◽  
Author(s):  
J. H. Griffin ◽  
C.-H. Menq
Keyword(s):  
Friction Force ◽  
Extreme Case ◽  
Circular Motion ◽  
Circular Path ◽  
Two Dimensional ◽  
Friction Contact ◽  
Constrained System ◽  
Peak Response ◽  
One Dimensional ◽  
Straight Line

When vibrating bodies are mutually constrained through friction contact they may move with respect to each other and dissipate energy at the interface. If the relative motion of the contacting surfaces follows a straight line the motion is said to be one-dimensional. This case has been examined extensively in the literature. More generally the point of contact can follow a path which is not a straight line. For the case of a periodic response the path will form a closed loop. In this paper we investigate the simplest, yet most extreme case of two dimensional motion—when the contacting point moves in a circular path. It is found that an exact solution can be derived for the problem of a frictionally constrained system when it is subjected to a circular excitation. The solution is used to determine the characteristics of the system’s response and they are compared with those for one-dimensional motion. In the case of one-dimensional motion if the contacting surfaces are compliant they will stick for at least a portion of each cycle. This is not the case for circular motion as it is found that the interface is either always stuck for small motions or always slipping if the excitation is above a certain level. This result suggests that the slip/stick transition which occurs during every cycle for the one-dimensional case may not be as important for the more general two-dimensional friction contact problem. Friction is often a major source of energy dissipation in vibrating machinery. As a result, the friction contact is sometimes used to reduce the peak response of the system by designing the contacting parts so as to have an optimum friction constraint. In order to investigate this effect expressions are derived for the peak amplitude as a function of the friction force, for the friction force that will minimize peak response, and for the amplitude of the peak response under optimum friction conditions. The results for circular motion are compared with those for straight line motion in order to assess the importance of two-dimensional effects.

Microdensitometer—computer correlation analysis of ultrastructural periodicity

1978 ◽  
Vol 36 (2) ◽  
pp. 32-33
Author(s):  
D.R. Ensor ◽  
C.G. Jensen ◽  
J.A. Fillery ◽  
R.J.K. Baker
Keyword(s):  
Correlation Analysis ◽  
Background Noise ◽  
Computer Control ◽  
Optical Diffraction ◽  
Screw Thread ◽  
Straight Line ◽  
Computer Storage ◽  
Correlation Process ◽  
Electron Microscope Image ◽  
Fixed Beam

Because periodicity is a major indicator of structural organisation numerous methods have been devised to demonstrate periodicity masked by background “noise” in the electron microscope image (e.g. photographic image reinforcement, Markham et al, 1964; optical diffraction techniques, Horne, 1977; McIntosh,1974). Computer correlation analysis of a densitometer tracing provides another means of minimising "noise". The correlation process uncovers periodic information by cancelling random elements. The technique is easily executed, the results are readily interpreted and the computer removes tedium, lends accuracy and assists in impartiality.A scanning densitometer was adapted to allow computer control of the scan and to give direct computer storage of the data. A photographic transparency of the image to be scanned is mounted on a stage coupled directly to an accurate screw thread driven by a stepping motor. The stage is moved so that the fixed beam of the densitometer (which is directed normal to the transparency) traces a straight line along the structure of interest in the image.

Freeze fracture imaging and computer simulation of liposome structure: Membrane geometry and defects

1983 ◽  
Vol 41 ◽  
pp. 646-647
Author(s):  
Joseph A. Zasadzinski
Keyword(s):  
Liquid Crystalline ◽  
Freeze Fracture ◽  
Continuum Theory ◽  
Closed Surfaces ◽  
Straight Line ◽  
Low Weight ◽  
Concentric Spheres ◽  
Membrane Geometry ◽  
Dupin Cyclides ◽  
Limiting Case

At low weight fractions, many surfactant and biological amphiphiles form dispersions of lamellar liquid crystalline liposomes in water. Amphiphile molecules tend to align themselves in parallel bilayers which are free to bend. Bilayers must form closed surfaces to separate hydrophobic and hydrophilic domains completely. Continuum theory of liquid crystals requires that the constant spacing of bilayer surfaces be maintained except at singularities of no more than line extent. Maxwell demonstrated that only two types of closed surfaces can satisfy this constraint: concentric spheres and Dupin cyclides. Dupin cyclides (Figure 1) are parallel closed surfaces which have a conjugate ellipse (r1) and hyperbola (r2) as singularities in the bilayer spacing. Any straight line drawn from a point on the ellipse to a point on the hyperbola is normal to every surface it intersects (broken lines in Figure 1). A simple example, and limiting case, is a family of concentric tori (Figure 1b).To distinguish between the allowable arrangements, freeze fracture TEM micrographs of representative biological (L-α phosphotidylcholine: L-α PC) and surfactant (sodium heptylnonyl benzenesulfonate: SHBS)liposomes are compared to mathematically derived sections of Dupin cyclides and concentric spheres.

Human Enamel Replication

1976 ◽  
Vol 34 ◽  
pp. 180-181
Author(s):  
Norman L. Dockum ◽  
John G. Dockum
Keyword(s):  
Organic Matrix ◽  
Human Teeth ◽  
Human Enamel ◽  
Straight Line ◽  
Ultrastructural Characteristics

Ultrastructural characteristics of fractured human enamel and acid-etched enamel were compared using acetate replicas shadowed with platinum and palladium. Shadowed replications of acid-etched surfaces were also obtained by the same method.Enamel from human teeth has a rod structure within which there are crystals of hydroxyapatite contained within a structureless organic matrix composed of keratin. The rods which run at right angles from the dentino-enamel junction are considered to run in a straight line perpendicular to the perimeter of the enamel, however, in many areas these enamel rods overlap, interlacing and intertwining with one another.

Background Fitting in the Low-Loss Region of Electron Energy Loss Spectra

1990 ◽  
Vol 48 (2) ◽  
pp. 56-57
Author(s):  
C P Scott ◽  
A J Craven ◽  
C J Gilmore ◽  
A W Bowen
Keyword(s):  
Energy Loss ◽  
Multiple Scattering ◽  
Simple Form ◽  
Single Scattering ◽  
Low Loss ◽  
Characteristic Energy ◽  
Normal Method ◽  
Fitting In ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

The normal method of background subtraction in quantitative EELS analysis involves fitting an expression of the form I=AE-r to an energy window preceding the edge of interest; E is energy loss, A and r are fitting parameters. The calculated fit is then extrapolated under the edge, allowing the required signal to be extracted. In the case where the characteristic energy loss is small (E < 100eV), the background does not approximate to this simple form. One cause of this is multiple scattering. Even if the effects of multiple scattering are removed by deconvolution, it is not clear that the background from the recovered single scattering distribution follows this simple form, and, in any case, deconvolution can introduce artefacts.The above difficulties are particularly severe in the case of Al-Li alloys, where the Li K edge at ~52eV overlaps the Al L2,3 edge at ~72eV, and sharp plasmon peaks occur at intervals of ~15eV in the low loss region. An alternative background fitting technique, based on the work of Zanchi et al, has been tested on spectra taken from pure Al films, with a view to extending the analysis to Al-Li alloys.

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