Spatial Kinematic Analysis of the Upper Extremity Using a Biplanar Videotaping Method

1981 ◽  
Vol 103 (1) ◽  
pp. 11-17 ◽  
Author(s):  
N. A. Langrana
Keyword(s):  
Upper Extremity ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Assistive Device ◽  
Kinematic Data ◽  
Computer Aided ◽  
Extremity Motion ◽  
Accuracy And Repeatability ◽  
Three Dimensional Space

A biplanar videotaping system is used to generate spatial kinematic data of an upper extremity motion. The technique is based upon the characterization of each segment by four points in three-dimensional space using biplanar videotaping and subsequent analysis by computer-aided descriptive geometry. The tests were conducted to determine the system’s accuracy and repeatability. The results of the joint kinematics of the test subjects performing a diagonal reaching activity with and without an orthosis (or an assistive device) are presented.

scholarly journals Isothermic surfaces in sphere geometries as Moutard nets

2007 ◽  
Vol 463 (2088) ◽  
pp. 3171-3193 ◽  
Author(s):  
Alexander I Bobenko ◽  
Yuri B Suris
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Gauss Map ◽  
Point Property ◽  
Property A ◽  
Lie Geometry ◽  
Möbius Geometry ◽  
Isothermic Surfaces ◽  
Three Dimensional Space

We give an elaborated treatment of discrete isothermic surfaces and their analogues in different geometries (projective, Möbius, Laguerre and Lie). We find the core of the theory to be a novel characterization of discrete isothermic nets as Moutard nets. The latter are characterized by the existence of representatives in the space of homogeneous coordinates satisfying the discrete Moutard equation. Moutard nets admit also a projective geometric characterization as nets with planar faces with a five-point property: a vertex and its four diagonal neighbours span a three-dimensional space. Restricting the projective theory to quadrics, we obtain Moutard nets in sphere geometries. In particular, Moutard nets in Möbius geometry are shown to coincide with discrete isothermic nets. The five-point property, in this particular case, states that a vertex and its four diagonal neighbours lie on a common sphere, which is a novel characterization of discrete isothermic surfaces. Discrete Laguerre isothermic surfaces are defined through the corresponding five-plane property, which requires that a plane and its four diagonal neighbours share a common touching sphere. Equivalently, Laguerre isothermic surfaces are characterized by having an isothermic Gauss map. S-isothermic surfaces as an instance of Moutard nets in Lie geometry are also discussed.

Energy Harvesting Aspects of Irregular Vibrating Forces Acting on Piezoelectric Devices

2015 ◽  
pp. 143-158
Author(s):  
Alessandro Massaro
Keyword(s):  
Energy Harvesting ◽  
Piezoelectric Materials ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Output Current ◽  
Vibrating System ◽  
External Forces ◽  
Piezoelectric Devices ◽  
Three Dimensional Space

After a brief introduction of piezoelectric materials, this chapter focuses on the characterization of vibrating freestanding piezoelectric AlN devices forced by different external forces acting simultaneously. The analyzed vibrating forces are applied mainly to piezoelectric freestanding structures stimulated by irregular vibration phenomena. Particular kinds of theoretical noise signals are commented. The goal of the chapter is to analyze the effect of the noise in order to model the chaotic vibrating system and to predict the output current signals. Moreover, the author also shows a possible alternative way to detect different vibrating force directions in the three dimensional space by means of curved piezoelectric layouts.

scholarly journals NMR Characterization of the Interactions Between Glycosaminoglycans and Proteins

2021 ◽  
Vol 8 ◽  
Author(s):  
Changkai Bu ◽  
Lan Jin
Keyword(s):  
Protein Interactions ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Gag Protein ◽  
Physiological Processes ◽  
Nmr Characterization ◽  
Mammalian Tissues ◽  
Three Dimensional Space

Glycosaminoglycans (GAGs) constitute a considerable fraction of the glycoconjugates found on cellular membranes and in the extracellular matrix of virtually all mammalian tissues. The essential role of GAG-protein interactions in the regulation of physiological processes has been recognized for decades. However, the underlying molecular basis of these interactions has only emerged since 1990s. The binding specificity of GAGs is encoded in their primary structures, but ultimately depends on how their functional groups are presented to a protein in the three-dimensional space. This review focuses on the application of NMR spectroscopy on the characterization of the GAG-protein interactions. Examples of interpretation of the complex mechanism and characterization of structural motifs involved in the GAG-protein interactions are given. Selected families of GAG-binding proteins investigated using NMR are also described.

scholarly journals On Chasles' Property of the Helicoid in Tri-Twisted Real Ambient Space

2015 ◽  
Vol 23 (2) ◽  
pp. 121-132
Author(s):  
Peter T. Ho ◽  
Lucy H. Odom ◽  
Bogdan D. Suceavă
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Arbitrary Point ◽  
Invariance Property ◽  
Elementary Property ◽  
Invariance Condition ◽  
Xixth Century ◽  
Rigidity Property ◽  
Three Dimensional Space

Abstract An elementary property of the helicoid is that at every point of the surface the following condition holds: cot θ = C · d; where d is the distance between an arbitrary point to the helicoid axis, and θ is the angle between the normal and the helicoid’s axis. This rigidity property was discovered by M. Chasles in the first half of the XIXth century. Starting from this property, we give a characterization of the so-called tri-twisted metrics on the real three dimensional space with the property that a given helicoid satisfies the classical invariance condition. Similar studies can be pursued in other geometric contexts. Our most general result presents a property of surfaces of rotation observing an invariance property suggested by the analogy with Chasles’s property.

A new variational characterization of three-dimensional space forms

2001 ◽  
Vol 145 (2) ◽  
pp. 251-278 ◽  
Author(s):  
Matthew J. Gursky ◽  
Jeff A. Viaclovsky
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Variational Characterization ◽  
Space Forms ◽  
Three Dimensional Space

scholarly journals Computer aided geological design: AutoCAD® applications in structural geology

2017 ◽  
Vol 13 (2) ◽  
pp. 113
Author(s):  
Sebastián González Chiozza
Keyword(s):  
Structural Geology ◽  
Structural Analysis ◽  
3D Modeling ◽  
Dimensional Space ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Geological Structures ◽  
Computer Aided ◽  
Fault Displacement ◽  
Three Dimensional Space

The three-dimensional (3D) modeling environment of AutoCAD is used to represent and solve problems of structural geology. As an alternative to bi-dimensional (2D) techniques of classical structural analysis, the 3D capabilities of the software are used for modeling, positioning and measuring geological structures. To introduce the proposed method, two practical examples are presented as exercises with detailed instructions. The technique consists in precisely representing the geometrical entities that comprise the geological problem within three-dimensional space to enable the direct measurement of structural parameters. Accurate results, such as fault displacement and the attitude of several structures, are obtained with the dimension tools of the program, so no calculations are required. Diverse 3D viewing perspectives can be adopted to enhance the comprehension of the analyzed situation.

A novel characterization of organic molecular crystal structures for the purpose of crystal engineering

2015 ◽  
Vol 71 (4) ◽  
pp. 463-477 ◽  
Author(s):  
Noel W. Thomas
Keyword(s):  
Crystal Structures ◽  
Crystal Engineering ◽  
Molecular Crystal ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Close Packing ◽  
Organic Molecular Crystal ◽  
Reference Axis ◽  
Three Dimensional Space

A novel analytical approach is proposed for the characterization of organic molecular crystal structures where close packing is an important factor. It requires the identification of a unique reference axis within the crystal, along which three-dimensional space is divided into close-packed blocks (CPB) and junction zones (JZ). The degree of close packing along the reference axis is quantified by a two-dimensional packing function, φ2D, of symmetry determined by the space group. Values of φ2Dreflect the degree of area-filling in planes perpendicular to this axis. The requirement of close packing within CPB allows the planar structures perpendicular to the reference axis to be analysed as tessellations of area-filling molecular-based cells (MBC), which are generally hexagonal. The form of these cells reflects the molecular shape in the cross-section, since their vertices are given by the centres of the voids between molecules. There are two basic types of MBC, Type 1, of glide or pseudo-glide symmetry, and Type 2, which is formed by lattice translations alone and generally requires a short unit-cell axis. MBC at layers of special symmetry are used to characterize the structures in terms of equivalent ellipses with parametersaell,belland χell. The ratioaell/bellallows the established α, β, γ classification to be integrated into the current framework. The values of parametersaellandbellarising from all the structures considered, polynuclear aromatic hydrocarbons (PAH), substituted anthracenes and anthraquinones (SAA) and 2-benzyl-5-benzylidene (BBCP) are mapped onto a universal curve. The division of three-dimensional space into CPB and JZ is fundamentally useful for crystal engineering, since the structural perturbations brought about by substitution at hydrogen positions located within JZ are minimal. A contribution is also made to ongoing debate concerning the adoption of polar space groups, isomorphism and polymorphism.

Extension of the Spatial PDI Model to Three Dimensions

1997 ◽  
Vol 84 (1) ◽  
pp. 176-178
Author(s):  
Frank O'Brien
Keyword(s):  
Population Density ◽  
Dimensional Space ◽  
Finite Lattice ◽  
Three Dimensional ◽  
Upper Bounds ◽  
Three Dimensions ◽  
Lower And Upper Bounds ◽  
Density Index ◽  
Three Dimensional Space

The author's population density index ( PDI) model is extended to three-dimensional distributions. A derived formula is presented that allows for the calculation of the lower and upper bounds of density in three-dimensional space for any finite lattice.

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