We examine the feasibility of designing a gyroscope-free inertial navigation system (INS) that uses only accelerometers to compute the linear and angular motions of a rigid body. The accelerometer output equation is d...
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We examine the feasibility of designing a gyroscope-free inertial navigation system (INS) that uses only accelerometers to compute the linear and angular motions of a rigid body. The accelerometer output equation is derived to relate the linear and angular motions of a rigid body relative to a fixed inertial frame. A sufficient condition is given to determine if a configuration of accelerometers is feasible. If the condition is satisfied, the angular and linear motions can be computed separately using two decoupled equations of an input-output (I/O) dynamical system; a state equation for angular velocity and an output equation for linear acceleration. This simple computation scheme is derived from the corresponding dynamical system equations for a special cube configuration for which the angular acceleration is expressed as a linear combination of the accelerometer outputs.
The Doubly Linked Face List (DLFL) structure introduces a powerful modeling paradigm that allows users to alternatively apply topological change operations and subdivision operations on a mesh structure. Moreover the ...
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ISBN:
(纸本)0769508537
The Doubly Linked Face List (DLFL) structure introduces a powerful modeling paradigm that allows users to alternatively apply topological change operations and subdivision operations on a mesh structure. Moreover the DLFL is topologically robust in the sense that it always guarantees valid 2-manifold surfaces. We further study the relationship between DLFL structure and subdivision algorithms. First, we develop a new corner cutting scheme, which provides a tension parameter to control the shape of the subdivided surface. Second, we develop a careful and efficient algorithm for our corner cutting scheme on the DLFL structure that uses only the basic operations provided by the DLFL structure. This implementation ensures that our new corner cutting scheme preserves topological robustness. The comparative study shows that the corner cutting schemes create better handles and holes than Catmull-Clark (1978) scheme.
Summary form only given. In a periodically modulated waveguide, an optical beam along the z direction is strongly coupled with the reflected beam if the index periodicity satisfies the Bragg condition. The optoelectro...
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Summary form only given. In a periodically modulated waveguide, an optical beam along the z direction is strongly coupled with the reflected beam if the index periodicity satisfies the Bragg condition. The optoelectronic effect is exploited to raise the index perturbation. AlGaAs is selected as the guiding layer because of its relatively high electro-optic coefficient and index flexibility. Interdigitated electrodes induce the periodic index perturbation.
Daphne is a computer-assisted musical analysis system that analyzes musical structure and other information necessary for computer music applications, especially for performance synthesis. The obtained analysis result...
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In this paper we present a case study of our candidate design for the user-interface of a wireless vital-signs monitor. We reflect on our design of the user-interface, and relate our design experience to theories of a...
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ISBN:
(纸本)9781450373265
In this paper we present a case study of our candidate design for the user-interface of a wireless vital-signs monitor. We reflect on our design of the user-interface, and relate our design experience to theories of artefact design, evaluating from this case study how the theories apply to the broader design context of design for AR. Theories of 'good design' in artefact design literature do not unilaterally apply to the design for an augmented reality device. In many cases, design in AR fields requires the designer to create new cultural conventions by virtue of the fact that the designer is immersing the user in an unfamiliar environment. Thus, the designer is often unable to utilise affordances and existing cultural conventions because the functions and/or use of the object expands the environment in which affordances and cultural conventions currently have meaning. Copyright 2000 ACM.
Signals from 12 soprano and mezzo-soprano singers are analyzed with the modal distribution, a high-resolution time-frequency analysis method, to obtain measures of instantaneous amplitude and frequency of the signals...
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Proposes a method for data clustering in a n-dimensional space using the elastic net algorithm which is a variant of the Kohonen topographic map learning algorithm. The elastic net algorithm is a mechanical metaphor i...
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Proposes a method for data clustering in a n-dimensional space using the elastic net algorithm which is a variant of the Kohonen topographic map learning algorithm. The elastic net algorithm is a mechanical metaphor in which an elastic ring is attracted by points in a bi-dimensional space while their internal elastic forces try to shun the elastic expansion. The different weights associated with these two kinds of forces lead the elastic to a gradual expansion in the direction of the bi-dimensional points. In this method, the elastic net algorithm is employed with the help of a heuristic framework that improves its performance for application in the n-dimensional space of cluster analysis. Tests were made with two types of data sets: (1) simulated data sets with up to 1000 points randomly generated in groups linearly separable with up to dimension 10 and (2) the Fisher Iris Plant database, a well-known database referred to in the pattern recognition literature. The advantages of the method presented are its simplicity, its fast and stable convergence, beyond efficiency in cluster analysis.
Photoconductance spectroscopy was used to probe the effects of quantum confinement in nanocrystalline (nc)-Si/amorphous (a)-SiO2 superlattices (SLs). A Metal-Oxide-Semiconductor (MOS)-like structure with the nc-Si SL ...
Photoconductance spectroscopy was used to probe the effects of quantum confinement in nanocrystalline (nc)-Si/amorphous (a)-SiO2 superlattices (SLs). A Metal-Oxide-Semiconductor (MOS)-like structure with the nc-Si SL incorporated in the oxide was fabricated to study charging/discharging processes in Si nanocrystals. The fine structure observed in photoconductance spectra at low temperatures was interpreted in terms of singularities in the carrier density of states, possibly due to energy quantization. In addition, a low-resistance sample exhibited photocurrent oscillations with a frequency of several kHz, which could be a manifestation of sequential resonant carrier tunneling in the nc-Si/a-SiO2 SL.
The AlGaN/GaN heterostructure is important for both electronic and optoelectronic devices. In addition to having a large band gap, the heterostructure has a strong piezoelectric effect and a large spontaneous polariza...
The AlGaN/GaN heterostructure is important for both electronic and optoelectronic devices. In addition to having a large band gap, the heterostructure has a strong piezoelectric effect and a large spontaneous polarization. This allows one to incorporate a large electric field (>106 V/cm) and high sheet charge (>1013 cm−2) without doping. Theoretical studies are done to examine how polarization effects controls the sheet charge density. The studies also focus on how interface roughness, aluminum mole fraction in the barrier, impurity scattering, sheet charge density, and phonon scattering influence mobility. Results are compared with experimental studies on samples grown by both molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD). We find that interface roughness is a dominant source of scattering in the samples reported. Due to the variation in growth techniques we find that the MBE samples have a smoother interface quality compared to the MOCVD samples. By carefully fitting the experimental data we present results on interface roughness parameters for MBE and MOCVD samples.
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