Motion Representation: Different Conventional Forms, Duplex Mapping and Conjugation Form

1992 ◽  
Author(s):  
Chih-Hsin Chen ◽  
Hong-Jian Chen
Keyword(s):  
Fundamental Equation ◽  
Body Motion ◽  
Surface Generation ◽  
Mobility Analysis ◽  
Vector Form ◽  
Motion Representation ◽  
Orientation Change ◽  
The Matrix ◽  
Potential Applications ◽  
Conjugate Surfaces

Abstract Four fundamental forms for representing rigid body motion, i.e. the rotation-of-vector form, the matrix form, the quaternion form and the screw form, all based on the conventional concept that motion is specified by the movement of a reference point together with an orientation change, are expounded. The inter-relationships among these forms are elucidated. The geometric images of these representation-forms, i.e. the motion mappings, are explained, and an innovative duplex-mapping, a powerful tool for mobility analysis of multi-loop mechanisms and robots, is introduced. An exotic motion representation, based on a concept totally different from the conventional concept, is described. This is a purely geometric representation, a representation by a pair of conjugate curves on respective conjugate surfaces, and is called the conjugation form of motion representation. The conversion from the conjugation form to the rotation-of-vector form and the inverse conversion are described. These conversions, which constitute the essential and featured contents of the Theory of Conjugate Surfaces, have great potential applications in motion design for numerically controlled manufacturing and in surface generation by numerically controlled manufacturing. The basis equations for the conversions, i.e. the three relationship-equations, are deduced. The fundamental equation conjugation, the four conjugato-kinematic entities and the five differential formulas for the inverse conversion are derived.

scholarly journals Development of a Decellularized Porcine Esophageal Matrix for Potential Applications in Cancer Modeling

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1055
Author(s):  
Hersh Chaitin ◽  
Michael L. Lu ◽  
Michael B. Wallace ◽  
Yunqing Kang
Keyword(s):  
Cell Growth ◽  
Lymphatic Vessels ◽  
Significant Loss ◽  
Cancer Cell Growth ◽  
Cell Growth And Migration ◽  
Decellularized Extracellular Matrix ◽  
Cancer Models ◽  
The Matrix ◽  
Potential Applications ◽  
And Migration

Many decellularized extracellular matrix-derived whole organs have been widely used in studies of tissue engineering and cancer models. However, decellularizing porcine esophagus to obtain decellularized esophageal matrix (DEM) for potential biomedical applications has not been widely investigated. In this study a modified decellularization protocol was employed to prepare a porcine esophageal DEM for the study of cancer cell growth. The cellular removal and retention of matrix components in the porcine DEM were fully characterized. The microstructure of the DEM was observed using scanning electronic microscopy. Human esophageal squamous cell carcinoma (ESCC) and human primary esophageal fibroblast cells (FBCs) were seeded in the DEM to observe their growth. Results show that the decellularization process did not cause significant loss of mechanical properties and that blood ducts and lymphatic vessels in the submucosa layer were also preserved. ESCC and FBCs grew on the DEM well and the matrix did not show any toxicity to cells. When FBS and ESCC were cocultured on the matrix, they secreted more periostin, a protein that supports cell adhesion on matrix. This study shows that the modified decellularization protocol can effectively remove the cell materials and maintain the microstructure of the porcine esophageal matrix, which has the potential application of studying cell growth and migration for esophageal cancer models.

Synthesis of Planar, Compliant Four-Bar Mechanisms for Compliant-Segment Motion Generation

1999 ◽  
Vol 123 (4) ◽  
pp. 535-541 ◽  
Author(s):  
L. Saggere ◽  
S. Kota
Keyword(s):  
Compliant Mechanisms ◽  
Shape Change ◽  
Synthesis Method ◽  
Elastic Equilibrium ◽  
Body Motion ◽  
Motion Generation ◽  
Generation Task ◽  
Potential Applications ◽  
Flexible Segment ◽  
Definition Of

Compliant four-bar mechanisms treated in previous works consisted of at least one rigid moving link, and such mechanisms synthesized for motion generation tasks have always comprised a rigid coupler link, bearing with the conventional definition of motion generation for rigid-link mechanisms. This paper introduces a new task called compliant-segment motion generation where the coupler is a flexible segment and requires a prescribed shape change along with a rigid-body motion. The paper presents a systematic procedure for synthesis of single-loop compliant mechanisms with no moving rigid-links for compliant-segment motion generation task. Such compliant mechanisms have potential applications in adaptive structures. The synthesis method presented involves an atypical inverse elastica problem that is not reported in the literature. This inverse problem is solved by extending the loop-closure equation used in the synthesis of rigid-links to the flexible segments, and then combining it with elastic equilibrium equation in an optimization scheme. The method is illustrated by a numerical example.

A High Invariance Motion Representation for Skeleton-Based Action Recognition

2016 ◽  
Vol 30 (08) ◽  
pp. 1650018 ◽  
Author(s):  
Songrui Guo ◽  
Huawei Pan ◽  
Guanghua Tan ◽  
Lin Chen ◽  
Chunming Gao
Keyword(s):  
Action Recognition ◽  
Relative Motion ◽  
Local Coordinate System ◽  
Research Work ◽  
Human Action Recognition ◽  
Human Action ◽  
Body Motion ◽  
Motion Representation ◽  
Representation Method ◽  
Relative Geometry

Human action recognition is very important and significant research work in numerous fields of science, for example, human–computer interaction, computer vision and crime analysis. In recent years, relative geometry features have been widely applied to the description of relative relation of body motion. It brings many benefits to action recognition such as clear description, abundant features etc. But the obvious disadvantage is that the extracted features severely rely on the local coordinate system. It is difficult to find a bijection between relative geometry and skeleton motion. To overcome this problem, many previous methods use relative rotation and translation between all skeleton pairs to increase robustness. In this paper we present a new motion representation method. It establishes a motion model based on the relative geometry with the aid of special orthogonal group SO(3). At the same time, we proved that this motion representation method can establish a bijection between relative geometry and motion of skeleton pairs. After the motion representation method in this paper is used, the computation cost of action recognition reduces from the two-way relative motion (motion from A to B and B to A) to one-way relative motion (motion from A to B or B to A) between any skeleton pair, namely, permutation problem [Formula: see text] is simplified into combinatorics problem [Formula: see text]. Finally, the experimental results of the three motion datasets are all superior to present skeleton-based action recognition methods.

Effect of Composition of Fibers on Properties of Hybrid Composites

2017 ◽  
Vol 7 (4) ◽  
pp. 28-43
Author(s):  
R. Panneer
Keyword(s):  
Glass Fiber ◽  
Hybrid Composites ◽  
Low Cost ◽  
Natural Fibers ◽  
Absorption Capacity ◽  
Weight Percentage ◽  
Specific Strength ◽  
The Matrix ◽  
Potential Applications ◽  
Weight Design

Fibers embedded in the matrix of another material are the best example of modern day composite materials. Hybrid Composites made out of an amalgamation of Natural Fibers such as banana, jute, and coir along with glass fiber embedded in polymers have potential applications in automotive, aircraft and marine industries for their unique characteristics like high specific strength, light weight, design flexibility, corrosion resistance, biodegradability and low cost. In this work, epoxy hybrid composites reinforced with glass fiber mats and banana, jute, coir fibers of random lengths between 10-25 mm are prepared by varying their compositions in terms of weight percentage. The composites are fabricated by hand lay-up process and cut into test specimens as per ASTM Standards. Their mechanical characteristics such as Tensile Strength, Flexural Strength, Impact Strength, Hardness, Density and Water Absorption Capacity are evaluated and analysed.

scholarly journals Surface Modification of PET Fiber with Hybrid Coating and Its Effect on the Properties of PP Composites

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1726 ◽  
Author(s):  
Yapeng Mao ◽  
Qiuying Li ◽  
Chifei Wu
Keyword(s):  
Surface Modification ◽  
Bending Strength ◽  
Dip Coating ◽  
Mechanical Analysis ◽  
Single Fiber ◽  
X Ray Diffraction ◽  
Fiber Modification ◽  
The Matrix ◽  
Potential Applications ◽  
Pp Composites

Surface modification fundamentally influences the morphology of polyethylene terephthalate (PET) fibers produced from abandoned polyester textiles and improve the compatibility between the fiber and the matrix. In this study, PET fiber was modified through solution dip-coating using a novel synthesized tetraethyl orthosilicate (TEOS)/KH550/ polypropylene (PP)-g-MAH (MPP) hybrid (TMPP). The PET fiber with TMPP modifier was exposed to the air. SiO2 particles would be hydrolyzed from TEOS and become the crystalline cores of MPP. Then, the membrane formed by MPP, SiO2 and KH550 covered the surface of the PET fiber. TMPP powder was investigated and characterized by fourier transform infrared spectroscopy, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). TMPP-modified PET fiber was researched by X-ray diffraction and SEM. Furthermore, tensile strength of single fiber was also tested. PET fiber/PP composites were studied through dynamic mechanical analysis and SEM. Flexural properties of composites were also measured. The interfacial properties of PET fiber and PP matrix were indirectly represented by contact angle analysis. Results showed that the addition of TEOS is helpful in homogenizing the distribution of PP-g-MAH. Furthermore, TMPP generates an organic-inorganic ‘armor’ structure on PET fiber, which can make up for the damage areas on the surface of PET fiber and strengthen each single-fiber by 14.4%. Besides, bending strength and modulus of TMPP-modified PET fiber-reinforced PP composite respectively, increase by 10 and 800 MPa. The compatibility between PET fiber and PP was also confirmed to be increased by TMPP. Predictably, this work supplied a new way for PET fiber modification and exploited its potential applications in composites.

Low-Leakage Modular Regenerators for Gas-Turbine Engines

1997 ◽  
Author(s):  
James Anthony Kluka ◽  
David Gordon Wilson
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Regenerative Heat ◽  
Turbine Engine ◽  
Low Leakage ◽  
The Matrix ◽  
Potential Applications ◽  
Ceramic Honeycomb

One of the significant problems plaguing regenerator designs is seal leakage resulting in a reduction of thermal efficiency. This paper describes the preliminary design and analysis of a new regenerative heat-exchanger concept, called a modular regenerator, that promises to provide improved seal-leakage performance. The modular regenerator concept consists of a ceramic-honeycomb matrix discretized into rectangular blocks, called modules. Separating the matrix into modules substantially reduces the transverse sealing lengths and substantially increases the longitudinal sealing lengths as compared with typical rotary designs. Potential applications can range from small gas-turbine engines for automotive applications to large stationary gas turbines for industrial power generation. Descriptions of two types of modular regenerators are presented including sealing concepts. Results of seal leakage analysis for typical modular regenerators sized for a small gas-turbine engine (120 kW) predict leakage rates under one percent for most seal-clearance heights.

Cable-Suspended Vehicle Simulation System Concept

2007 ◽  
Author(s):  
Robert L. Williams
Keyword(s):  
Flight Simulation ◽  
Body Motion ◽  
Whole Body ◽  
Input Devices ◽  
Vehicle Simulation ◽  
Surround Sound ◽  
Flight Simulators ◽  
Potential Applications ◽  
High Bandwidth ◽  
Human Operators

This paper presents a concept for virtual-reality-based vehicle simulation with whole-body haptics. The cable-suspended NIST RoboCrane is adapted to carry human operators in simulating a variety of vehicle motions. A realistic, immersive VR system is proposed with 3D graphics, haptic motion input devices, 3D surround-sound audio, articulating fans, and an olfactory generator. The real-world cockpit and input devices will be used to increase realism, suspended from nine active cables for motion simulation. The intent is to replace existing heavy, expensive, and dangerous Stewart-Platform-based flight simulators with a lighter, more economical, stiff, safe, high bandwidth, cable-suspended system. Many potential applications are proposed in addition to flight simulation. Our long-term goal is to create an economical, safe, realistic vehicle simulator with full-body motion for operator training, research & development, vehicle design, entertainment, rehabilitation, and therapy.

Curvature Analysis of Conjugate Surfaces via a Tensor Approach

2012 ◽  
Vol 163 ◽  
pp. 251-255
Author(s):  
Peng Wang ◽  
Yi Du Zhang ◽  
Jie Deng
Keyword(s):  
Rigid Body ◽  
Helical Gear ◽  
Body Motion ◽  
Local Geometry ◽  
Line Contact ◽  
Rotation Tensor ◽  
Curvature Analysis ◽  
Conjugate Surfaces ◽  
Invariant Approach ◽  
Derivation Process

A novel invariant approach is proposed for derivation of curvature relationship between conjugate surfaces of line contact. Unlike other approaches found in the literature, tensor analysis is applied to the derivation process in which rigid-body motion is represented by rotation tensor and the local geometry of surface is expressed by curvature tensor, and the final result is given in a clear and compact form. An example of helical gear is provided to illustrate the application of the proposed approach.

scholarly journals Size-Controlled Transformation of Cu2O into Zero Valent Copper within the Matrix of Anion Exchangers via Green Chemical Reduction

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2629
Author(s):  
Irena Jacukowicz-Sobala ◽  
Ewa Stanisławska ◽  
Agnieszka Baszczuk ◽  
Marek Jasiorski ◽  
Elżbieta Kociołek-Balawejder
Keyword(s):  
Chemical Reduction ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Mechanical Resistance ◽  
Anion Exchangers ◽  
Design And Synthesis ◽  
The Matrix ◽  
Potential Applications ◽  
Great Possibility ◽  
Basic Anion

Composite materials containing zero valent copper (ZVC) dispersed in the matrix of two commercially available strongly basic anion exchangers with a macroreticular (Amberlite IRA 900Cl) and gel-like (Amberlite IRA 402OH) structure were obtained. Cu0 particles appeared in the resin phase as the product of the reduction of the precursor, i.e., copper oxide(I) particles previously deposited in the two supporting materials. As a result of a one-step transformation of preformed Cu2O particles as templates conducted using green reductant ascorbic acid and under mild conditions, macroporous and gel-type hybrid products containing ZVC were obtained with a total copper content of 7.7 and 5.3 wt%, respectively. X-ray diffraction and FTIR spectroscopy confirmed the successful transformation of the starting oxide particles into a metallic deposit. A scanning electron microscopy study showed that the morphology of the deposit is mainly influenced by the type of matrix exchanger. In turn, the drying steps were crucial to its porosity and mechanical resistance. Because both the shape and size of copper particles and the internal structure of the supporting solid materials can have a decisive impact on the potential applications of the obtained materials, the results presented here reveal a great possibility for the design and synthesis of functional nanocrystalline solids.

Introduction of L12-Ordered Precipitation to Alumina-Forming Austenitic Heat-Resistant Steels With Low Ni Content

2017 ◽  
Author(s):  
Bingbing Zhao ◽  
Xianping Dong ◽  
Feng Sun ◽  
Lanting Zhang
Keyword(s):  
High Temperature ◽  
Power Plants ◽  
Tensile Tests ◽  
Atomic Ratio ◽  
Composition Analysis ◽  
Heat Resistant ◽  
Ni Content ◽  
The Matrix ◽  
Potential Applications ◽  
Heat Resistant Steels

Alumina-forming austenitic (AFA) heat-resistant steels have been reported as a promising new class of steels in recent years with potential applications in advanced ultra-supercritical power plants. It is well known that L12-ordered γ’ phase is the most important precipitate for high-temperature strengthening in Ni-based superalloys and it can be stabilized by increasing the Ni content in heat-resistant steels. In the current work, the evolution of L12-ordered precipitates were compared in the Cu-bearing AFA alloys with 20, 27 and 35 wt.% Ni. After slow tensile tests at 700°C (∼2 × 10−5 s−1), L12-ordered precipitates occurred in all the alloys. Alloy AFA27 displayed the most densely distributed L12-particles in the matrix, whose ultimate tensile strength was also the highest. However, the L12-ordered precipitates were only observed in alloy AFA27 after the slow tensile test at 750°C due to the thermodynamic and kinetic reasons. Flow curves of slow tensile tests indicated different precipitation behaviors at 700°C and 750°C. Chemical composition analysis and thermodynamic calculation revealed that the occurrence of L12-ordered Ni-Cu-Al phase depends on temperature, Ni content and the atomic ratio of Ni/Al. This opens up new opportunities to promote the formation of L12-ordered phase in Fe-based austenitic heat-resistant steels with low Ni content and benefits high-temperature strengthening.

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