On the Terminology for Redundant Parallel Manipulators

2008 ◽  
Author(s):  
Andreas Mu¨ller
Keyword(s):  
Dynamic Properties ◽  
Parallel Manipulators ◽  
Point Of View ◽  
Linear Control Systems ◽  
Parallel Kinematics ◽  
Parallel Kinematics Machines ◽  
Geometric Point ◽  
Different Types ◽  
Potential Applications ◽  
General Mathematical Model

Different types of redundancy in parallel kinematics machines (PKM) can be used to improve their kinematic and dynamic properties. The meaning of redundancy of PKM is often differently understood in the literature. In this paper a terminology for redundant PKM is proposed. The basis for this classification is a general mathematical model. With the help of this model PKM are regarded as non-linear control systems. The different types of redundancy are clearly distinguished, and their potential applications are discussed. Redundancy is considered from a geometric point of view. Redundancy is a means to deal with singularities of PKM. The different types of singular configurations are considered in the paper, and the potential of redundancy to cope with such situations is discussed. Again singularities are considered from a geometric point of view.

On the terminology and geometric aspects of redundant parallel manipulators

Robotica ◽  
2012 ◽  
Vol 31 (1) ◽  
pp. 137-147 ◽  
Author(s):  
Andreas Müller
Keyword(s):  
Vector Fields ◽  
Kinematic Model ◽  
Parallel Manipulators ◽  
Redundant Actuation ◽  
Parallel Kinematics ◽  
Kinematic Redundancy ◽  
Control Vector ◽  
Serial Manipulators ◽  
Actuation Redundancy ◽  
Parallel Kinematics Machines

SUMMARYParallel kinematics machines (PKMs) can exhibit kinematics as well as actuation redundancy. While the meaning of kinematic redundancy has been already clarified for serial manipulators, actuation redundancy, which is only possible in PKMs, is differently classified in the literature. In this paper a consistent terminology for general redundant PKM is proposed. A kinematic model is introduced with the configuration space (c-space) as central part. The notion of kinematic redundancy is recalled for PKM. C-space, output, and input singularities are distinguished. The significance of the c-space geometry is emphasized, and it is pointed out geometrically that input singularities can be avoided by redundant actuation schemes. In order to distinguish different actuation schemes of PKM, a nonlinear control system is introduced whose dynamics evolves on c-space. The degree of actuation (DOA) is introduced as the number of independent control vector fields, and PKMs are classified as full-actuated and underactuated machines. Relating this DOA to degree of freedom allows to classify the actuation redundancy.

Decorative motifs on oil lamps from Grimm's 1973 excavations in Alexandria

2019 ◽  
Author(s):  
Heba Abdel Wahed Sayed
Keyword(s):  
Point Of View ◽  
Symbolic Meaning ◽  
Ancient History ◽  
Different Types ◽  
Decorative Motifs ◽  
Egyptian Culture ◽  
Late Roman

A collection of 30 clay oil lamps from Gunther Grimm's excavations in 1973 in the Western necropolis of Alexandria has been classified by Safaa Samir Abu Al Yazid from Tanta University and found to represent 12 different types ranging in time from the Hellenistic to the late Roman periods in Egypt's ancient history. The present paper looks at this collection from the point of view of the symbolic significance of the decorative motifs used in their decoration. These motifs— figural, floral and geometric—had obvious symbolic meaning to their users and signified more than a simple belief in certain deities. They also reflected Roman Egyptian culture.

Microcavities

2017 ◽  
Author(s):  
Alexey V. Kavokin ◽  
Jeremy J. Baumberg ◽  
Guillaume Malpuech ◽  
Fabrice P. Laussy
Keyword(s):  
Quantum Wells ◽  
Strong Light ◽  
Fundamental Physics ◽  
Postgraduate Students ◽  
Optical Cavities ◽  
Semiconductor Quantum Wells ◽  
Exciton Polaritons ◽  
Different Types ◽  
Potential Applications ◽  
Experimental Findings

Both rich fundamental physics of microcavities and their intriguing potential applications are addressed in this book, oriented to undergraduate and postgraduate students as well as to physicists and engineers. We describe the essential steps of development of the physics of microcavities in their chronological order. We show how different types of structures combining optical and electronic confinement have come into play and were used to realize first weak and later strong light–matter coupling regimes. We discuss photonic crystals, microspheres, pillars and other types of artificial optical cavities with embedded semiconductor quantum wells, wires and dots. We present the most striking experimental findings of the recent two decades in the optics of semiconductor quantum structures. We address the fundamental physics and applications of superposition light-matter quasiparticles: exciton-polaritons and describe the most essential phenomena of modern Polaritonics: Physics of the Liquid Light. The book is intended as a working manual for advanced or graduate students and new researchers in the field.

scholarly journals Engineering nucleosomes for generating diverse chromatin assemblies

2021 ◽  
Author(s):  
Zenita Adhireksan ◽  
Deepti Sharma ◽  
Phoi Leng Lee ◽  
Qiuye Bao ◽  
Sivaraman Padavattan ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Dna Nanostructures ◽  
Macromolecular Assemblies ◽  
Maximum Resolution ◽  
Different Types ◽  
Chromatin Structural ◽  
Dna Fragment

Abstract Structural characterization of chromatin is challenging due to conformational and compositional heterogeneity in vivo and dynamic properties that limit achievable resolution in vitro. Although the maximum resolution for solving structures of large macromolecular assemblies by electron microscopy has recently undergone profound increases, X-ray crystallographic approaches may still offer advantages for certain systems. One such system is compact chromatin, wherein the crystalline state recapitulates the crowded molecular environment within the nucleus. Here we show that nucleosomal constructs with cohesive-ended DNA can be designed that assemble into different types of circular configurations or continuous fibers extending throughout crystals. We demonstrate the utility of the method for characterizing nucleosome compaction and linker histone binding at near-atomic resolution but also advance its application for tackling further problems in chromatin structural biology and for generating novel types of DNA nanostructures. We provide a library of cohesive-ended DNA fragment expression constructs and a strategy for engineering DNA-based nanomaterials with a seemingly vast potential variety of architectures and histone chemistries.

scholarly journals Mesoporous Silica Nanoparticles: Their Projection in Nanomedicine

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
María Vallet-Regí
Keyword(s):  
Drug Delivery ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Surrounding Medium ◽  
Stimuli Responsive ◽  
Guest Molecules ◽  
Different Types ◽  
Potential Applications ◽  
Inorganic Nanomaterials

Mesoporous silica nanoparticles are receiving growing attention by the scientific biomedical community. Among the different types of inorganic nanomaterials, mesoporous silica nanoparticles have emerged as promising multifunctional platforms for nanomedicine. Since their introduction in the drug delivery landscape in 2001, mesoporous materials for drug delivery are receiving growing scientific interest for their potential applications in the biotechnology and nanomedicine fields. The ceramic matrix efficiently protects entrapped guest molecules against enzymatic degradation or denaturation induced by pH and temperature as no swelling or porosity changes take place as a response to variations in the surrounding medium. It is possible to load huge amounts of cargo into the mesopore voids and capping the pore entrances with different nanogates. The application of a stimulus provokes the nanocap removal and triggers the departure of the cargo. This strategy permits the design of stimuli-responsive drug delivery nanodevices.

scholarly journals Embodied Energy and Embodied GWP of Windows: A Critical Review

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3788
Author(s):  
Francesco Asdrubali ◽  
Marta Roncone ◽  
Gianluca Grazieschi
Keyword(s):  
Critical Analysis ◽  
Strong Dependence ◽  
Primary Energy ◽  
Point Of View ◽  
Embodied Energy ◽  
Construction Sector ◽  
Industrialized Countries ◽  
Different Types ◽  
Operational Phase ◽  
Operational Impact

The construction sector is one of the most energy-intensive in the industrialized countries. In order to limit climate change emissions throughout the entire life cycle of a building, in addition to reducing energy consumption in the operational phase, attention should also be paid to the embodied energy and CO2 emissions of the building itself. The purpose of this work is to review data on embodied energy and GWP derived from EPDs of different types of windows, to identify the LCA phases, the most impacting materials and processes from an environmental point of view and to perform a critical analysis of the outcomes. The results show a strong dependence on the typology of the frame, with wooden windows having competitive performances: lower average primary energy non-renewable (1123 MJ/FU), higher average primary energy renewable (respectively 817 MJ/FU) and lower global warming potential (54 kgCO2eq/FU). More transparency and standardization in the information conveyed by the program operators is, however, desirable for a better comparability of windows performances. In particular, the inclusion of the operational impact in the EPD is sporadic, but strongly important, since it can be the most impactful phase.

scholarly journals Microgels and Nanoparticles: Where Micro and Nano Go Hand in Hand

2015 ◽  
Vol 229 (1-2) ◽  
Author(s):  
Beatriz H. Juarez ◽  
Luis M. Liz-Marzán
Keyword(s):  
Magnetic Nanoparticles ◽  
Optical Tweezers ◽  
Hybrid System ◽  
Inorganic Nanoparticles ◽  
Stimuli Responsive ◽  
Single Particles ◽  
Nanoscale Systems ◽  
Different Types ◽  
Potential Applications ◽  
Very High

AbstractThe integration of different types of materials in a single hybrid system allows the combination of multiple functionalities, which can even be used in conjunction with each other. This strategy has been exploited in nanoscale systems for the creation of so-called smart nanomaterials. Within this category, the combination of inorganic nanoparticles with stimuli-responsive microgels is of very high interest because of the wide variety of potential applications. We present here a short overview of this type of materials in which the nano- and micro-scales get nicely integrated, with a great potential to expand the range of technological applications. We focus mainly on the integration of metal nanoparticles, either by themselves or in combination with semiconductor and magnetic nanoparticles. Various examples of the synergic properties that can be obtained are described, as well as the possibility to extract useful information when optical tweezers are used to manipulate single particles. We expect that this review will stimulate additional research in this field.

scholarly journals Laws of the iterated logarithm on covering graphs with groups of polynomial volume growth

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ryuya Namba
Keyword(s):  
Random Walks ◽  
Quadratic Forms ◽  
Volume Growth ◽  
Moderate Deviation ◽  
Point Of View ◽  
Iterated Logarithm ◽  
Large Numbers ◽  
Geometric Point ◽  
Rate Functions ◽  
The Given

AbstractModerate deviation principles (MDPs) for random walks on covering graphs with groups of polynomial volume growth are discussed in a geometric point of view. They deal with any intermediate spatial scalings between those of laws of large numbers and those of central limit theorems. The corresponding rate functions are given by quadratic forms determined by the Albanese metric associated with the given random walks. We apply MDPs to establish laws of the iterated logarithm on the covering graphs by characterizing the set of all limit points of the normalized random walks.

Text Analysis of Project Completion Reports

2021 ◽  
Author(s):  
César E. Montiel Olea ◽  
Leonardo R. Corral
Keyword(s):  
Text Analysis ◽  
Text Documents ◽  
Project Completion ◽  
Analysis Tools ◽  
Development Effectiveness ◽  
Different Types ◽  
Potential Applications ◽  
Project Cycle ◽  
Main Instrument ◽  
Unique Dataset

Project Completion Reports (PCRs) are the main instrument through which different multilateral organizations measure the success of a project once it closes. PCRs are important for development effectiveness as they serve to understand achievements, failures, and challenges within the project cycle they can feed back into the design and execution of new projects. The aim of this paper is to introduce text analysis tools for the exploration of PCR documents. We describe and apply different text analysis tools to explore the content of a sample of PCRs. We seek to illustrate a way in which PCRs can be summarized and analyzed using innovative tools applied to a unique dataset. We believe that the methods presented in this investigation have numerous potential applications to different types of text documents routinely prepared within the Inter-American Development Bank (IDB).

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