scholarly journals On the design of traps for feeding 3D parts on vibratory tracks

Robotica ◽  
2008 ◽  
Vol 26 (4) ◽  
pp. 537-550 ◽  
Author(s):  
Onno C. Goemans ◽  
A. Frank van der Stappen
Keyword(s):  
Geometric Structure ◽  
State Of The Art ◽  
Motion Model ◽  
Trap Design ◽  
Design Algorithm ◽  
New Class ◽  
Complete Set ◽  
Algorithmic Design ◽  
Bowl Feeder ◽  
Part Motion

SUMMARYIn the context of automated feeding (orienting) of industrial parts, we study the algorithmic design of traps in the bowl feeder track that filter out all but one orientation of a given polyhedral part. We propose a new class of traps that removes a V-shaped portion of the track. The proposed work advances the state-of-the-art in algorithmic trap design by extending earlier work1,6,17—which focuses solely on 2D parts—to 3D parts, and by incorporating a more realistic part motion model in the design algorithm. We exploit the geometric structure of the design problem and build on concepts and techniques from computational geometry to obtain an efficient algorithm that reports the complete set of valid traps.

scholarly journals Modeling Pedestrian Motion in Crowded Scenes Based on the Shortest Path Principle

2021 ◽  
Vol 12 (1) ◽  
pp. 381
Author(s):  
Yi Zou ◽  
Yuncai Liu
Keyword(s):  
Shortest Path ◽  
State Of The Art ◽  
Meaningful Work ◽  
Movement Behavior ◽  
Motion Model ◽  
Human Dynamics ◽  
Motion Trajectories ◽  
Crowd Motion ◽  
Crowded Scenes ◽  
Part Motion

In the computer vision field, understanding human dynamics is not only a great challenge but also very meaningful work, which plays an indispensable role in public safety. Despite the complexity of human dynamics, physicists have found that pedestrian motion in a crowd is governed by some internal rules, which can be formulated as a motion model, and an effective model is of great importance for understanding and reconstructing human dynamics in various scenes. In this paper, we revisit the related research in social psychology and propose a two-part motion model based on the shortest path principle. One part of the model seeks the origin and destination of a pedestrian, and the other part generates the movement path of the pedestrian. With the proposed motion model, we simulated the movement behavior of pedestrians and classified them into various patterns. We next reconstructed the crowd motions in a real-world scene. In addition, to evaluate the effectiveness of the model in crowd motion simulations, we created a new indicator to quantitatively measure the correlation between two groups of crowd motion trajectories. The experimental results show that our motion model outperformed the state-of-the-art model in the above applications.

scholarly journals A Millennial Myosin Census

2001 ◽  
Vol 12 (4) ◽  
pp. 780-794 ◽  
Author(s):  
Jonathan S. Berg ◽  
Bradford C. Powell ◽  
Richard E. Cheney
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Phylogenetic Analysis ◽  
Molecular Basis ◽  
General Interest ◽  
Class Iii ◽  
New Class ◽  
The Past ◽  
Human Genes ◽  
Complete Set ◽  
Myosin Superfamily

The past decade has seen a remarkable explosion in our knowledge of the size and diversity of the myosin superfamily. Since these actin-based motors are candidates to provide the molecular basis for many cellular movements, it is essential that motility researchers be aware of the complete set of myosins in a given organism. The availability of cDNA and/or draft genomic sequences from humans,Drosophila melanogaster, Caenorhabditis elegans, Arabidopsis thaliana,Saccharomyces cerevisiae, Schizosaccharomyces pombe, andDictyostelium discoideum has allowed us to tentatively define and compare the sets of myosin genes in these organisms. This analysis has also led to the identification of several putative myosin genes that may be of general interest. In humans, for example, we find a total of 40 known or predicted myosin genes including two new myosins-I, three new class II (conventional) myosins, a second member of the class III/ninaC myosins, a gene similar to the class XV deafness myosin, and a novel myosin sharing at most 33% identity with other members of the superfamily. These myosins are in addition to the recently discovered class XVI myosin with N-terminal ankyrin repeats and two human genes with similarity to the class XVIII PDZ-myosin from mouse. We briefly describe these newly recognized myosins and extend our previous phylogenetic analysis of the myosin superfamily to include a comparison of the complete or nearly complete inventories of myosin genes from several experimentally important organisms.

scholarly journals Sperm Cell Driven Microrobots—Emerging Opportunities and Challenges for Biologically Inspired Robotic Design

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 448 ◽  
Author(s):  
Ajay Singh ◽  
Mohammad Ansari ◽  
Mihir Mahajan ◽  
Shubhangi Srivastava ◽  
Shubham Kashyap ◽  
...  
Keyword(s):  
Targeted Drug Delivery ◽  
State Of The Art ◽  
Cell Manipulation ◽  
Small Scale ◽  
Sperm Cells ◽  
Biologically Inspired ◽  
New Class ◽  
Targeted Drug ◽  
New Applications ◽  
Coupling Mechanisms

With the advent of small-scale robotics, several exciting new applications like Targeted Drug Delivery, single cell manipulation and so forth, are being discussed. However, some challenges remain to be overcome before any such technology becomes medically usable; among which propulsion and biocompatibility are the main challenges. Propulsion at micro-scale where the Reynolds number is very low is difficult. To overcome this, nature has developed flagella which have evolved over millions of years to work as a micromotor. Among the microscopic cells that exhibit this mode of propulsion, sperm cells are considered to be fast paced. Here, we give a brief review of the state-of-the-art of Spermbots—a new class of microrobots created by coupling sperm cells to mechanical loads. Spermbots utilize the flagellar movement of the sperm cells for propulsion and as such do not require any toxic fuel in their environment. They are also naturally biocompatible and show considerable speed of motion thereby giving us an option to overcome the two challenges of propulsion and biocompatibility. The coupling mechanisms of physical load to the sperm cells are discussed along with the advantages and challenges associated with the spermbot. A few most promising applications of spermbots are also discussed in detail. A brief discussion of the future outlook of this extremely promising category of microrobots is given at the end.

scholarly journals Deep Learning Architecture for Collaborative Filtering Recommender Systems

2020 ◽  
Vol 10 (7) ◽  
pp. 2441 ◽  
Author(s):  
Jesus Bobadilla ◽  
Santiago Alonso ◽  
Antonio Hernando
Keyword(s):  
Neural Network ◽  
Deep Learning ◽  
Collaborative Filtering ◽  
Recommender Systems ◽  
State Of The Art ◽  
Prediction Errors ◽  
Abstraction Level ◽  
Complete Set ◽  
Open Datasets ◽  
Abstraction Levels

This paper provides an innovative deep learning architecture to improve collaborative filtering results in recommender systems. It exploits the potential of the reliability concept to raise predictions and recommendations quality by incorporating prediction errors (reliabilities) in the deep learning layers. The underlying idea is to recommend highly predicted items that also have been found as reliable ones. We use the deep learning architecture to extract the existing non-linear relations between predictions, reliabilities, and accurate recommendations. The proposed architecture consists of three related stages, providing three stacked abstraction levels: (a) real prediction errors, (b) predicted errors (reliabilities), and (c) predicted ratings (predictions). In turn, each abstraction level requires a learning process: (a) Matrix Factorization from ratings, (b) Multilayer Neural Network fed with real prediction errors and hidden factors, and (c) Multilayer Neural Network fed with reliabilities and hidden factors. A complete set of experiments has been run involving three representative and open datasets and a state-of-the-art baseline. The results show strong prediction improvements and also important recommendation improvements, particularly for the recall quality measure.

scholarly journals Mechanisms of action of ionic liquids on living cells: the state of the art

2020 ◽  
Vol 12 (5) ◽  
pp. 1187-1215 ◽  
Author(s):  
Pallavi Kumari ◽  
Visakh V.S. Pillai ◽  
Antonio Benedetto
Keyword(s):  
Ionic Liquids ◽  
Cell Membrane ◽  
State Of The Art ◽  
Industrial Applications ◽  
Mechanisms Of Action ◽  
The State ◽  
New Class ◽  
Interdisciplinary Field ◽  
Micro Organisms ◽  
Enzyme Functions

Abstract Ionic liquids (ILs) are a relatively new class of organic electrolytes composed of an organic cation and either an organic or inorganic anion, whose melting temperature falls around room-temperature. In the last 20 years, the toxicity of ILs towards cells and micro-organisms has been heavily investigated with the main aim to assess the risks associated with their potential use in (industrial) applications, and to develop strategies to design greener ILs. Toxicity, however, is synonym with affinity, and this has stimulated, in turn, a series of biophysical and chemical-physical investigations as well as few biochemical studies focused on the mechanisms of action (MoAs) of ILs, key step in the development of applications in bio-nanomedicine and bio-nanotechnology. This review has the intent to present an overview of the state of the art of the MoAs of ILs, which have been the focus of a limited number of studies but still sufficient enough to provide a first glimpse on the subject. The overall picture that emerges is quite intriguing and shows that ILs interact with cells in a variety of different mechanisms, including alteration of lipid distribution and cell membrane viscoelasticity, disruption of cell and nuclear membranes, mitochondrial permeabilization and dysfunction, generation of reactive oxygen species, chloroplast damage (in plants), alteration of transmembrane and cytoplasmatic proteins/enzyme functions, alteration of signaling pathways, and DNA fragmentation. Together with our earlier review work on the biophysics and chemical-physics of IL-cell membrane interactions (Biophys. Rev. 9:309, 2017), we hope that the present review, focused instead on the biochemical aspects, will stimulate a series of new investigations and discoveries in the still new and interdisciplinary field of “ILs, biomolecules, and cells.”

scholarly journals Thermodynamics of Charged Rotating Dilaton Black Branes Coupled to Logarithmic Nonlinear Electrodynamics

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
A. Sheykhi ◽  
M. H. Dehghani ◽  
M. Kord Zangeneh
Keyword(s):  
Thermal Stability ◽  
Electromagnetic Coupling ◽  
Nonlinear Electrodynamics ◽  
Black Brane ◽  
Dilaton Field ◽  
Coupling Constant ◽  
De Sitter ◽  
New Class ◽  
Unstable Phase ◽  
Complete Set

We construct a new class of charged rotating black brane solutions in the presence of logarithmic nonlinear electrodynamics with complete set of the rotation parameters in arbitrary dimensions. The topology of the horizon of these rotating black branes is flat, while due to the presence of the dilaton field the asymptotic behavior of them is neither flat nor (anti-)de Sitter [(A)dS]. We investigate the physical properties of the solutions. The mass and angular momentum of the spacetime are obtained by using the counterterm method inspired by AdS/CFT correspondence. We derive temperature, electric potential, and entropy associated with the horizon and check the validity of the first law of thermodynamics on the black brane horizon. We study thermal stability of the solutions in both canonical and grand-canonical ensemble and disclose the effects of the rotation parameter, nonlinearity of electrodynamics, and dilaton field on the thermal stability conditions. We find the solutions are thermally stable forα<1, while forα>1the solutions may encounter an unstable phase, whereαis dilaton-electromagnetic coupling constant.

Importance of Nanosensors: Feynman's Vision and the Birth of Nanotechnology

MRS Bulletin ◽  
2007 ◽  
Vol 32 (9) ◽  
pp. 718-725 ◽  
Author(s):  
Jozef T. Devreese
Keyword(s):  
Molecular Level ◽  
State Of The Art ◽  
Fast Response ◽  
Atomic Scale ◽  
Advanced Materials ◽  
New Class ◽  
Intelligent Sensors ◽  
Integrated Devices ◽  
Further Development ◽  
Better Than

In his visionary 1959 lecture at Caltech, Richard P. Feynman foresaw the potential of the ability to manipulate matter at the atomic scale. In this article, adapted from Integrated Nanosensors, MRS Symposium Proceedings Volume 952E, edited by I.K. Schuller, Y. Bruynseraede, L.M. Lechuga, and E. Johnson (2007), Jozef T. Devreese (University of Antwerp) discusses implementations of Feynman's vision in the field of nanosensors and perspectives of its further development and applications.Nanoparticles are unique tools as sensors. Particles with sizes at the nanoscale reveal physical properties that do not exist in bulk materials; these properties can operate well inside living cells. Nanosensors possess unique physical characteristics. Their sensitivity can be orders of magnitude better than that of conventional devices. Nanosensors possess such performance advantages as fast response and portability. State-of-the-art nanosensors are based on various advanced materials (quantum dots, nanoshells, nanopores, carbon nanotubes, etc.). Nanosensors furthermore allow for building an entirely new class of integrated devices that provide the elemental base for “intelligent sensors” capable of data processing, storage, and analysis. Advances can open unprecedented perspectives for the application of nanosensors in various fields, for example, as molecular-level diagnostic and treatment instruments in medicine and as networks of nanorobots for real-time monitoring of physiological parameters of a human body.

The cybotactic nematic phase of bent-core mesogens: state of the art and future developments

Soft Matter ◽  
2014 ◽  
Vol 10 (39) ◽  
pp. 7685-7691 ◽  
Author(s):  
Oriano Francescangeli ◽  
Francesco Vita ◽  
Edward T. Samulski
Keyword(s):  
Nematic Phase ◽  
State Of The Art ◽  
New Class ◽  
Future Developments ◽  
Molecular Clustering ◽  
Anisotropic Fluids

Cybotaxis, the molecular clustering observed in bent-core nematics, governs the unique properties of this new class of anisotropic fluids.

scholarly journals Using the properties of vehicles in the conceptof the multi-environment multi-modal quantomobile

2020 ◽  
Vol 17 (6) ◽  
pp. 195-205
Author(s):  
Ju. G. Kotikov ◽  
Keyword(s):  
Numerical Modeling ◽  
Research And Development ◽  
Physical Vacuum ◽  
Motion Model ◽  
Single Family ◽  
Coordinate Systems ◽  
Hypothetical Model ◽  
Ground Vehicle ◽  
New Class ◽  
The One

The development of the concept of the quantum engine, that uses the energy of physical vacuum, makes it possible to create a new class of vehicles, namely, the quantomobile, designed as a quantum - powered vehicle. The type of quantum vehicles can be versatile, starting from the simplest version (with the ground vehicle driving modes) to the multi-environment multi-modal quantomobile that can function on land, in the air and in water. To work out a hypothetical model of the multi-environment multi-modal quantomobile, it is necessary to use all the heritage of research and development in the sphere of transport engineering. For 10 variants of the multi-environment multi-modal quantomobile movement - from the air quantum helicopter (quantocraft) to a quantum submarine (quantomarine) - there has been made an analysis of the numerical modeling specifics, the use of coordinate systems, the implementation of the traffic of existing transport vehicles that can be reflected in the concept of multi-environment quantomobile. Two extreme methods of modeling are distinguished: 1) the one based on a single family of coordinate systems and a common (end-to-end for all types of environment) motion model; 2) the one based on models by type of motion with possible switching of coordinate systems.

scholarly journals An unrecognized inertial force induced by flow curvature in microfluidics

2021 ◽  
Vol 118 (29) ◽  
pp. e2103822118
Author(s):  
Siddhansh Agarwal ◽  
Fan Kiat Chan ◽  
Bhargav Rallabandi ◽  
Mattia Gazzola ◽  
Sascha Hilgenfeldt
Keyword(s):  
Entire Range ◽  
State Of The Art ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Inertial Force ◽  
Inertial Forces ◽  
Inertial Effects ◽  
Inviscid Flows ◽  
Flow Curvature ◽  
Complete Set

Modern inertial microfluidics routinely employs oscillatory flows around localized solid features or microbubbles for controlled, specific manipulation of particles, droplets, and cells. It is shown that theories of inertial effects that have been state of the art for decades miss major contributions and strongly underestimate forces on small suspended objects in a range of practically relevant conditions. An analytical approach is presented that derives a complete set of inertial forces and quantifies them in closed form as easy-to-use equations of motion, spanning the entire range from viscous to inviscid flows. The theory predicts additional attractive contributions toward oscillating boundaries, even for density-matched particles, a previously unexplained experimental observation. The accuracy of the theory is demonstrated against full-scale, three-dimensional direct numerical simulations throughout its range.

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