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.
This paper presents a methodology for the segmentation and analysis of the tissues in color images of leg ulcers. The segmentation is obtained through an automatic analysis made in the RGB and SI channels by changing ...
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ISBN:
(纸本)0769511139
This paper presents a methodology for the segmentation and analysis of the tissues in color images of leg ulcers. The segmentation is obtained through an automatic analysis made in the RGB and SI channels by changing from the RGB color space to the HSI color space. The aim is to determine which of the five channels have the characteristic that will make the segmentation process more efficient. After the analysis, the selected channel is segmented and used as a mask over the original image, allowing that only the inner tissues of the wound be analyzed. The analysis is done through predetermined functions that attribute membership grade for each processed pixel as well as its level of engagement in a specified tissue class. The article also shows the results obtained from both the segmentation and analysis of tissues using the proposed method.
Proposes an information system to support complex physiological information models. The system architecture requires three essential parts: a networked client that generates a request for information; a computation se...
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Proposes an information system to support complex physiological information models. The system architecture requires three essential parts: a networked client that generates a request for information; a computation server that performs the calculation; and a model database that provides detailed parameters to the computation server to facilitate solution. The model database is organized as an object-oriented hierarchy following the design used to store medical images and their metadata in accordance with the international DICOM standard for medical images. A fourth critical component is also defined: a case database that archives the input data that has been used by the client to define the case to be computed, and archives the output from the solution. This system is applied to a complex contemporary model of the electrophysiology of cardiac myocyte cells.
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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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.
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.
Although NMR has the ability to investigate biological systems non-destructively, it suffers from low sensitivity compared to other analytical techniques. Therefore, optimizing radio frequency (RF) coils to improve se...
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Although NMR has the ability to investigate biological systems non-destructively, it suffers from low sensitivity compared to other analytical techniques. Therefore, optimizing radio frequency (RF) coils to improve sensitivity is an area of significant focus in NMR Sensitivity can be improved for mass- and volume-limited samples by reducing, coil diameter, and adding sensing layers to the coil. This paper demonstrates that around skin depth, coil sensitivity can be increased with additional sensing layers, by using multilayered scroll coil geometries. While solenoids have demonstrated increased sensitivity over conventional coils (Helmholtz, Saddle, and Birdcage), their dimensions are limited by wire diameter, and difficulty in fabrication at reduced dimensions. The novel scroll geometry avails of microfabrication techniques to provide flexibility in manufacturing coils at very reduced dimensions.
Summary form only given. We report the room temperature operation of a novel unipolar self-organized quantum dot FIR laser (13.3 /spl mu/m) based on transitions between discrete bound electron states in self-organized...
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Summary form only given. We report the room temperature operation of a novel unipolar self-organized quantum dot FIR laser (13.3 /spl mu/m) based on transitions between discrete bound electron states in self-organized dots. A typical photoluminescence spectrum of InGaAs-GaAs self-organized quantum dots is shown.
Presents a neural-based approach to classifying and estimating the statistical parameters of speckle noise found in biomedical ultrasound images. Speckle noise, a very complex phenomenon, has been modeled in a variety...
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Presents a neural-based approach to classifying and estimating the statistical parameters of speckle noise found in biomedical ultrasound images. Speckle noise, a very complex phenomenon, has been modeled in a variety of different ways: and there is currently no clear consensus as to its precise statistical characteristics. In this study, different neural network architectures are used to classify ultrasound images contaminated with three types of noise, based upon three one-parameter statistical distributions. At the same time: the parameter is estimated. It is expected that accurate characterization of ultrasound speckle noise will benefit existing post-processing methods, and may lead to new refinements in these techniques.
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