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Abstract

Details

Industrial Robot: An International Journal, vol. 44 no. 4
Type: Research Article
ISSN: 0143-991X

Content available
Article
Publication date: 1 April 2004

Giovanni Muscato

349

Abstract

Details

Industrial Robot: An International Journal, vol. 31 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Content available
Article
Publication date: 3 May 2010

Giovanni Muscato

503

Abstract

Details

Industrial Robot: An International Journal, vol. 37 no. 3
Type: Research Article
ISSN: 0143-991X

Article
Publication date: 1 April 2004

Domenico Longo and Giovanni Muscato

The system proposed in this paper is the Alicia3 robot, which is based on the Alicia II module. Its aim is to inspect non‐porous vertical walls like those of aboveground…

1083

Abstract

The system proposed in this paper is the Alicia3 robot, which is based on the Alicia II module. Its aim is to inspect non‐porous vertical walls like those of aboveground petrochemical tanks, with a wide range of surface materials and cleanliness levels. To meet this aim, pneumatic‐like adhesion has been selected for the system. The system is also required to move over the surface at a suitable speed, to pass over obstacles and to have a suitable payload to carry mission‐specific instrumentation. The robot design mainly aimed at finding a solution with a high degree of modularity, so that it can easily be disassembled for maintenance purposes and to replace consumable parts such as the wheels and the sealing, making its design easier. Some onboard control algorithms have also been introduced to increase system reliability and reduce energy consumption.

Details

Industrial Robot: An International Journal, vol. 31 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 1 April 2000

Jack Hollingum

There has been a considerable growth of interest in climbing and walking robots since the first international conference in Brussels last year. The two‐day event at…

Abstract

There has been a considerable growth of interest in climbing and walking robots since the first international conference in Brussels last year. The two‐day event at Portsmouth University attracted speakers from 20 countries, a number of whom were able to report on machines that have been built and successfully tested, and in some cases are under evaluation in industry. Supporting these from the end of academic research were papers dealing with simulation, control, locomotion, teleoperation, navigation, sensing and other aspects. Much of the work is being funded by the European Commission under the Brite‐Euram programme. The conference was preceded by a workshop day and included a small industrial exhibition.

Details

Industrial Robot: An International Journal, vol. 27 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Content available
Article
Publication date: 1 April 2004

Clive Loughlin

398

Abstract

Details

Industrial Robot: An International Journal, vol. 31 no. 2
Type: Research Article
ISSN: 0143-991X

Article
Publication date: 1 March 2005

Giovanni Mascali and Vittorio Romano

On the basis of the maximum entropy principle, seeks to formulate a hydrodynamical model for electron transport in GaAs semiconductors, which is free of any fitting parameter.

Abstract

Purpose

On the basis of the maximum entropy principle, seeks to formulate a hydrodynamical model for electron transport in GaAs semiconductors, which is free of any fitting parameter.

Design/methodology/approach

The model considers the conduction band to be described by the Kane dispersion relation and includes both Γ and L valleys. Takes into account electron‐non‐polar optical phonon, electron‐polar optical phonon and electro‐acoustic phonon scattering.

Findings

The set of balance equation of the model forms a quasilinear hyperbolic system and for its numerical integration a recent high‐order shock‐capturing central differencing scheme has been employed.

Originality/value

Presents the results of simulations of n+ ‐nn+ GaAs diode and Gunn oscillator.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 24 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 31 January 2020

Marco Coco and Giovanni Nastasi

The purpose of this paper is to simulate charge transport in monolayer graphene on a substrate made of hexagonal boron nitride (h-BN). This choice is motivated by the fact…

Abstract

Purpose

The purpose of this paper is to simulate charge transport in monolayer graphene on a substrate made of hexagonal boron nitride (h-BN). This choice is motivated by the fact that h-BN is one of the most promising substrates on account of the reduced degradation of the velocity due to the remote impurities.

Design/methodology/approach

The semiclassical Boltzmann equations for electrons in the monolayer graphene are numerically solved by an approach based on a discontinuous Galerkin (DG) method. Both the conduction and valence bands are included, and the inter-band scatterings are taken into account as well.

Findings

The importance of the inter-band scatterings is accurately evaluated for several values of the Fermi energy, addressing the issue related to the validity of neglecting the generation-recombination terms. It is found out that the inclusion of the inter-band scatterings produces sizable variations in the average values, like the current density, at zero Fermi energy, whereas, as expected, the effect of the inter-band scattering becomes negligible by increasing the absolute value of the Fermi energy.

Research limitations/implications

The correct evaluation of the influence of the inter-band scatterings on the electronic performances is deeply important not only from a theoretical point of view but also for the applications. In particular, it will be shown that the time necessary to reach the steady state is greatly affected by the inter-band scatterings, with not negligible consequences on the switching on/off processes of realistic devices. As a limitation of the present work, the proposed approach refers to the spatially homogeneous case. For the simulation of electron devices, non-homogenous numerical solutions are required. This last case will be tackled in a forthcoming paper.

Originality/value

As observed in Majorana et al. (2019), the use of a Direct Simulation Monte Carlo (DSMC) approach, which properly describes the inter-band scatterings, is computationally very expensive because the valence band is highly populated and a huge number of particles is needed. Even by simulating holes instead of electrons does not overcome the problem because there is a certain degree of ambiguity in the generation and recombination terms of electron-hole pairs. The DG approach, used in this paper, does not suffer from the previous drawbacks and requires a reasonable computing effort.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 39 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 2 March 2012

Giovanni Mascali and Vittorio Romano

This paper intends to present a hydrodynamical model which describes the hole motion in silicon and couples holes and electrons.

Abstract

Purpose

This paper intends to present a hydrodynamical model which describes the hole motion in silicon and couples holes and electrons.

Design/methodology/approach

The model is based on the moment method and the closure of the system of moment equations is obtained by using the maximum entropy principle (hereafter MEP). The heavy, light and split‐off valence bands are considered. The first two are described by taking into account their warped shape, while for the split‐off band a parabolic approximation is used.

Findings

The model for holes is coupled with an analogous one for electrons, so obtaining a complete description of charge transport in silicon. Numerical simulations are performed both for bulk silicon and a p‐n junction.

Research limitations/implications

The model uses a linear approximation of the maximum entropy distribution in order to close the system of moment equations. Furthermore, the non‐parabolicity of the heavy and light bands is neglected. This implies an approximation on the high field results. This issue is under current investigation.

Practical implications

The paper improves the previous hydrodynamical models on holes and furnishes a complete model which couples electrons and holes. It can be useful in simulations of bipolar devices.

Originality/value

The results of the paper are new since a better approximation of the band structure is used and a description of both electron and hole behavior is present, therefore the results are of a certain relevance for the theory of charge transport in semiconductors.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

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