1,246 research outputs found
A phenomenological approach to multisource data integration: Analysing infrared and visible data
A new method is described for combining multisensory data for remote sensing applications. The approach uses phenomenological models which allow the specification of discriminatory features that are based on intrinsic physical properties of imaged surfaces. Thermal and visual images of scenes are analyzed to estimate surface heat fluxes. Such analysis makes available a discriminatory feature that is closely related to the thermal capacitance of the imaged objects. This feature provides a method for labelling image regions based on physical properties of imaged objects. This approach is different from existing approaches which use the signal intensities in each channel (or an arbitrary linear or nonlinear combination of signal intensities) as features - which are then classified by a statistical or evident approach
Positional estimation techniques for an autonomous mobile robot
Techniques for positional estimation of a mobile robot navigation in an indoor environment are described. A comprehensive review of the various positional estimation techniques studied in the literature is first presented. The techniques are divided into four different types and each of them is discussed briefly. Two different kinds of environments are considered for positional estimation; mountainous natural terrain and an urban, man-made environment with polyhedral buildings. In both cases, the robot is assumed to be equipped with single visual camera that can be panned and tilted and also a 3-D description (world model) of the environment is given. Such a description could be obtained from a stereo pair of aerial images or from the architectural plans of the buildings. Techniques for positional estimation using the camera input and the world model are presented
High density p-type Bi0.5Sb1.5Te3 nanowires by electrochemical templating through ion-track lithography
High density p-type Bi0.5Sb1.5Te3 nanowire arrays are produced by a combination of electrodeposition and ion-track lithography technology. Initially, the electrodeposition of p-type wBi(0.5)Sb(1.5)Te(3) films is investigated to find out the optimal conditions for the deposition of nanowires. Polyimide-based Kapton foils are chosen as a polymer for ion track irradiation and nanotemplating Bi0.5Sb1.5Te3 nanowires. The obtained nanowires have average diameters of 80 nm and lengths of 20 mu m, which are equivalent to the pore size and thickness of Kapton foils. The nanowires exhibit a preferential orientation along the {110} plane with a composition of 11.26 at.% Bi, 26.23 at.% Sb, and 62.51 at.% Te. Temperature dependence studies of the electrical resistance show the semiconducting nature of the nanowires with a negative temperature coefficient of resistance and band gap energy of 0.089 +/- 0.006 eV
Математическое моделирование сложных объектов с распределенными параметрами в задачах автоматического управления структурно-перестраиваемых систем
Рассматривается моделирование управления нестационарными температурными полями объектов со сложной геометрической конфигурацией. Приводятся сравнительные динамические характеристики замкнутых систем автоматического регулирования с перестраиваемой и фиксированной структурами
Nanostructured thermoelectric generator for energy harvesting
This paper presents the development processes towards a new generation of nanostructured thermoelectric generators for power harvesting from small temperature gradients by using a combination of traditional silicon microfabrication techniques, electroplating and submicron ion-track nanolithography. Polyimide nanotemplates with pore diameters ranging from 30nm to 120 nm were fabricated. Preliminary results for Bi2Te3 nanowires (50 and 120 nm diameter) electroplated into polycarbonate ion-track commercial membranes are presented. Bi2Te3 nanowires of R ̄ 3m structure, with preferential orientation in the (015) and (110) crystallographic plans with nearly stoichiometric composition were electroplated. The fine-grained observed microstructure (6-10 nm) and (110) crystalline orientation appear extremely promising for improving thermoelectric material properties
View-Invariant Regions and Mobile Robot Self-Localization
This paper addresses the problem of mobile robot self-localization
given a polygonal map and a set of observed edge segments. The
standard approach to this problem uses interpretation tree search with
pruning heuristics to match observed edges to map edges. Our approach
introduces a preprocessing step in which the map is decomposed into
'view-invariant regions' (VIRs). The VIR decomposition captures
information about map edge visibility, and can be used for a variety of
robot navigation tasks. Basing self-localization
search on VIRs greatly reduces the branching factor of the search
tree and thereby simplifies the search task. In this paper we define
the VIR decomposition and give algorithms for its computation and for
self-localization search. We present results of simulations comparing
standard and VIR-based search, and discuss the application of the VIR
decomposition to other problems in robot navigation
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Recombination in the Open-Ended Value Landscape of Digital Innovation
Digital innovation introduces a new open-ended value landscape to anyone seeking to generate or capture new value. To understand this landscape, we distinguish between design recombination and use recombination, explore how they play out together, and redirect the attention from products and services toward digital resources. Digital resources serve as building-blocks in digital innovation, and they hold the potential to simultaneously be part of multiple value paths, offered through design recombination and assembled through use recombination. Building on this perspective, we offer the value spaces framework as a tool for better understanding value creation and capture in digital innovation. We illustrate the framework and offer the early contours of a research agenda for information systems researchers
Ion-track etched templates for the high density growth of nanowires of bismuth telluride and bismuth antimony telluride by electrodeposition
We report the electrochemical growth of high density arrays of n- type Bi2Te3 and p-type Bi0.5Sb1.5Te3 nanowires into ion-track etched polyimide-based Kapton membranes with a density of 5 x 109 wires/cm2. The average diameter of the nanowires is 80 nm with a length of 20 µm, which is comparable to the pore size and thickness of the employed Kapton foils. The electroplating parameters and microstructural properties are reported for the nanowires whilst thermoelectric properties have been investigated for thin films of Bi2Te3 and Bi0.5Sb1.5Te3
Understanding the selective etching of electrodeposited ZnO nanorods
ZnO nanotubes were prepared by selective dissolution of electrodeposited nanorods. The effect of solution pH, rod morphology, and chloride ion concentration on the dissolution mechanism was studied. The selective etching was rationalized in terms of the surface energy of the different ZnO crystal faces and reactant diffusion. The nanorod diameter and chloride concentration are the most influential parameters on the dissolution mechanism because they control homogeneous dissolution or selective etching of the (110) and (002) surfaces. Bulk solution pH only has an effect on the rate of dissolution. By accurate control of the dissolution process, the nanomorphology can be tailored, and the formation of rods with a thin diameter (10-20 nm), cavity, or ultra-thin-walled tubes (2-5 nm) can be achieved
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