We consider the problem of target location estimation in the context of large scale, dense sensor networks. We model the probability of detection in each sensor, p(d), as a function of the distance between the sensor ...
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ISBN:
(纸本)0780385454
We consider the problem of target location estimation in the context of large scale, dense sensor networks. We model the probability of detection in each sensor, p(d), as a function of the distance between the sensor and the target. Based on a binary (detection vs. no detection) information from each sensor and the model Of p(d), we propose two different fusion rules for estimating the target location: a maximum likelihood estimate and an empirical risk minimization method. Moreover, we also consider the case where only sensors with a positive detection transmit their reading. This can be helpful to economize the power of sensor units. By employing gaussian like p(d) models, we develop versions of both methods based on simple initialization procedures and a gradient search. We compare and discuss both algorithms in terms of complexity and accuracy.
This paper proposes an iterative compensation method to deal with relative change of sound source location caused by rapid movements of a microphone array and a sound source. This method introduces a delay filter that...
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ISBN:
(纸本)0780385454
This paper proposes an iterative compensation method to deal with relative change of sound source location caused by rapid movements of a microphone array and a sound source. This method introduces a delay filter that has shifted and sampled sinc functions. This paper presents a concept that applies both the error function of the adaptive algorithms to estimate two-dimensional direction-of-arrival and the coordinate system of a moving microphone array. This method directly estimates the relative directions of the microphone array to the sound source directions by minimizing the relative differences of arrival time among the observed signals, not by estimating the time difference of arrival (TDOA) between two observed signals. This method compensates the time delay of the observed signals simultaneously, and it has a feature to ensure that the output signals are in phase. Simulation results support effectiveness of the method.
This paper describes sound spot generation by 128-channel surrounded speaker array. A sound spot is a limited area within which an emitted sound is amplified. Sound spot generation is achieved by the Sum and Delay Bea...
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ISBN:
(纸本)0780385454
This paper describes sound spot generation by 128-channel surrounded speaker array. A sound spot is a limited area within which an emitted sound is amplified. Sound spot generation is achieved by the Sum and Delay Beam Former (SDBF). A dedicated PCI 128-channel simultaneous input digital-to-analog (D/A) board is developed for a 128 channel speaker array with a maximum sampling rate of 22.7 us/sample. The 128-channel square speaker array can generate steerable a sound spot towards a specific point. Sound spots can be moved in approximately 10 ms. The speaker array can also generate different sound spots at specific points simultaneously. The performance of sound spot generation is evaluated by using sound pressure distribution maps. The speaker array can be used to that transmit necessary sound information to only a specific person in quiet places, such as a museum and a hospital.
Electronic noses and tongues are two recent examples in chemical sensing that employ statistical array techniques in order to overcome the intrinsic limitations of current solid-state chemical sensors like ion-selecti...
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ISBN:
(纸本)0780385454
Electronic noses and tongues are two recent examples in chemical sensing that employ statistical array techniques in order to overcome the intrinsic limitations of current solid-state chemical sensors like ion-selective field transistors (ISFET). In particular, ISFETs are sensitive to the concentration of a particular ion in a solution to be measured, but it can be also strongly affected by several interfering ions found in the solution. Hence, they must be employed in regions in which the effect of interferences is negligible thus limiting their range of operation. However, since ISFETs behave as non-linear mixers of main ion activities and interfering ones, an attempt to separate the original main ion activity and interferences from the mixed response is suitable with blind source separation (BSS) techniques and related methods like independent component analysis (ICA) methods. In this direction, several experiments with real ISFET measurements demonstrate the interest of employing BSS for dealing with the separation in ISFET responses, and further reconstruction, of ion activities in those operating regions in which interferences notably affect their response.
Single- and dual-polarized arrays are used for direction-of-arrival estimation. In this paper, we present a generalized framework describing the spatio-polarimetric correlation properties of both types of arrays. It i...
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This work proposes a train wheel detection system based on an electromagnetic sensorarray. This sensorarray is distributed in points along a section of the railway. Each sensor of the array is located next to the ra...
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The presence of measurement noise and model uncertainties in sensorarrays and the lack of statistical information poses several challenges for development of effective and robust algorithms for the Direction-of-Arriv...
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In this paper, an improved ultrasonic system for detection of falling objects or alive beings intrusion in railways is presented. The basic ultrasonic arraysensor is composed of four emitters and six receivers and ca...
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Wavefield Modeling is a formalism for arrayprocessing based on expressing the output of a sensors' array as a product of a wavefieId-independent sampling matrix and an array-independent coefficient vector. This a...
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This work describes a sensorarray based on optical emitters, which allows to detect obstacles in railways. The sensorial system consists of a barrier of emitters and another of receivers, placed at opposite sides of ...
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