The design and characterization of a multi-modality system is presented for imaging of breast lesions based on co-registered diffuse optical and X-Ray tomography. Inherent limitations of X-Ray are overcome by combinat...
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Ultrasonic backscatter can provide information on the density of scatterers within biological media, and is therefore an important tool in tissue characterization. In this paper, a novel neural network approach to est...
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Ultrasonic backscatter can provide information on the density of scatterers within biological media, and is therefore an important tool in tissue characterization. In this paper, a novel neural network approach to estimate scatterer density from generalized entropy is proposed. Neural estimation compares favorably with nonlinear least-squares models.
Energy-efficient communication is critical for increasing life of power limited wireless ad hoc networks. There has been considerable interest in minimum energy broadcast operations. In this paper, we develop bounds a...
Energy-efficient communication is critical for increasing life of power limited wireless ad hoc networks. There has been considerable interest in minimum energy broadcast operations. In this paper, we develop bounds and an algorithm for minimizing energy cost for broadcasting from any source to all other nodes in the network. Most prior work have used simpler model for energy cost for wireless communications by accounting only the analog radiation cost for transmission and ignored the fixed cost for electronics in transmission and reception circuitry in nodes. Furthermore, in a network it is possible for some node pairs not be able to communicate directly even though they are in their radio ranges due to obstacles present in the terrain of the network.
作者：
Vieira, Luis CarlosPrograma de Pós-Graduação em Engenharia Elétrica e Informática Industrial
Departamento de Eletrônica e Telecomunicações (Graduate Program in Electrical Engineering and Industrial Computer Science Department of Electronics and Telecommunications) Centro Federal de Educação Tecnológica do Paraná (Federal Center of Technological Education of Paraná) Curitiba Brazil
A neural-statistical approach to biomedical image interpolation using generalized regression neural networks is presented. These networks are basis function architectures that approximate any arbitrary function betwee...
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ISBN:
(纸本)0780370449
A neural-statistical approach to biomedical image interpolation using generalized regression neural networks is presented. These networks are basis function architectures that approximate any arbitrary function between input and output vectors directly from training samples, and with any desired degree of smoothness, and thus can be used for multidimensional interpolation. Experimental results compare favorably with other interpolation techniques. Because of their flexibility and ease of training, generalized regression networks can be used to complement existing approaches, and can be especially useful for post-registration image fusion and visualization.
We report an observation of essentially full spatial coherence in a high average power soft-x-ray laser. Rapid coherence buildup due to strong refractive antiguiding in a long plasma column is experimentally demonstra...
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We report an observation of essentially full spatial coherence in a high average power soft-x-ray laser. Rapid coherence buildup due to strong refractive antiguiding in a long plasma column is experimentally demonstrated. This allows the generation of fully coherent, milliwatt-level average power soft-x-ray radiation by a tabletop device. The peak brightness of this laser reaches 2×1025photonss−1mm−2mrad−2 within 0.01% spectral bandwidth, making it one of the brightest soft-x-ray sources available.
Routing in ad-hoc networks is a difficult challenge that involves a tradeoff between efficiency and responsiveness. An ad-hoc network routing algorithm must adapt rapidly enough to topology changes to meet the perform...
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ISBN:
(纸本)0769510922
Routing in ad-hoc networks is a difficult challenge that involves a tradeoff between efficiency and responsiveness. An ad-hoc network routing algorithm must adapt rapidly enough to topology changes to meet the performance demands of users, without over-utilizing network resources. This paper presents the (/spl alpha/,t) cluster framework which utilizes a distributed dynamic clustering strategy to organize nodes into clusters in which the probability of path failure due to node movement can be bounded over time. The objective of the clustering strategy is to achieve scalability and support robust, efficient routing subject to a wide range of mobility rates. Based on the (/spl alpha/,t) cluster scheme, routes within clusters are maintained on a proactive basis, whereas hierarchical routing between clusters is managed on a demand-basis. Simulation results show that the cluster organization can be effectively adapted to node mobility and that routing is both more robust and efficient than routing in fully proactive, reactive or fixed-hybrid schemes.
A micro-mechanical switch has been designed and fabricated in which the bounce after contact closure has been reduced by using mechanical momentum transfer and magnetic damping, while maintaining high contact forces. ...
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ISBN:
(纸本)0780359984
A micro-mechanical switch has been designed and fabricated in which the bounce after contact closure has been reduced by using mechanical momentum transfer and magnetic damping, while maintaining high contact forces. The period of chatter has been reduced from 1.5 milliseconds to less than 0.3 milliseconds, while the switching speed is 5 millisecond. The switch has been fabricated using Permalloy (78% Ni and 22% Fe) and copper. The LIGA process was used in the fabrication of the switch. An improved copper process allowed the fabrication of high aspect ratio (20:1) structures which were subsequently freed and assembled.
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.
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