New radar technology applications need more and more advancedsignalprocessingalgorithms. In order to design processingalgorithms it is necessary to dispose sufficiently accurate signal model. In this paper the 2-d...
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ISBN:
(纸本)8390666278
New radar technology applications need more and more advancedsignalprocessingalgorithms. In order to design processingalgorithms it is necessary to dispose sufficiently accurate signal model. In this paper the 2-d correlation properties of sea surface radar return are analysed. The data for the analysis are real registered radar signals. The results show the dependence of correlation coefficients and correlation distances on range. Some parameters of power spectral density are introduced and analysed too. The conclusions formulated can be useful formodelling, simulation and segmentation of 2-d radar signals (images).
tracking the structure health status of the aircraft fleet is one of the important factors for improving safety in the aviation industry. US Airforce Research Lab is working hard to develop technology to monitor the s...
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ISBN:
(数字)9781728101378
ISBN:
(纸本)9781728101378
tracking the structure health status of the aircraft fleet is one of the important factors for improving safety in the aviation industry. US Airforce Research Lab is working hard to develop technology to monitor the structural health status of aircraft before and after takeoff. This technology is called Structural Health Monitoring or Structural Health Management (SHM), and uses advancedsignalprocessing techniques. The advantages of this include improving the technology and safety factors of the aircraft by increasing the robustness of the aircraft structure as well as reduce the cost of the labor maintenance. This research paper focuses on developing a software system that is capable of detecting a crack in the aircraft structure at an early stage Also, the developed software will be used to estimate the crack lengths within 90% accuracy. The developed software uses the Matlab environment for all algorithms developed: calculating and finding the crack, and estimating the crack length. Artificial Intelligent (AI) techniques such as fuzzy logic and neural networks are used to support the decision regarding the length of the crack Also, developed decision fusion frameworks are designed to increase the accurate percentage rate of the decision making results. The results obtained from this research are compared with the baseline developed by The Air Force Research Laboratory (AFRL). Finally, the results of this research along with the capabilities of using advancedsignalprocessing integrated with AI, show that the calculations for the crack and the crack length produce very acceptable results using a real data gathered by AFRL. Also, the percentage average error performance analysis of the developed software's system algorithms is provided in the research paper.
The research presents a preliminary approach to perform any type of image processing task using 16-bit digital signal controllers. Even though this attempt is aimed at Edge Detection, the research opens up possibiliti...
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ISBN:
(纸本)9783642259432
The research presents a preliminary approach to perform any type of image processing task using 16-bit digital signal controllers. Even though this attempt is aimed at Edge Detection, the research opens up possibilities for numerous other algorithms of signal and image processing that can be implemented using the same low cost hardware. FPGA's & DSP's are widely used to perform hardware-based signalprocessing task. It is an efficient but generally an expensive solution for image processing applications. On the other hand a conventional 8-bit MCU doesn't have enough capability to handle memory intensive DSP algorithms. In this regard. a digital signal controller offers a tradeoff between cost and performance.
A novel approach is proposed to overcome the maximum range limitations of noise radar technology while enhancing the computational efficiency of the correlation processing of batches of samples. The proposed algorithm...
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ISBN:
(纸本)9788394942113
A novel approach is proposed to overcome the maximum range limitations of noise radar technology while enhancing the computational efficiency of the correlation processing of batches of samples. The proposed algorithm also permits to flexibly manage both Range and Doppler ambiguities in the system design.
The problem addressed in this paper is to removing unwanted sounds from music sound. The sound to be removed could be disturbance such as cough. We shall present some preliminary results on this problem using statisti...
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ISBN:
(纸本)0819437611
The problem addressed in this paper is to removing unwanted sounds from music sound. The sound to be removed could be disturbance such as cough. We shall present some preliminary results on this problem using statistical properties of signals. Our approach consists of three steps. We first estimate the fundamental frequencies and partials given noise-corrupted music sound. This gives us the autoregressive (AR) model of the music sound. Then se filter the noise-corrupted sound using the AR parameters. The filtered signal is then subtracted from the original noise-corrupted signal to get the disturbance. Finally the obtained disturbance is used as reference signal to eliminate the disturbance from the noise-corrupted music signal. Above three steps are carried out in a recursive manner using a sliding window or an infinitely growing window with an appropriate forgetting factor.
Sound and Vision Engineering as an interdisciplinary branch of science should quickly assimilate new methods and new technologies. Meanwhile, there exist some advanced and well developed methods for analyzing and proc...
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This paper outlines means of combining and reconciling concepts associated with Cohen's class of distributions and with the wavelet transform. Both have their assets and their liabilities. Previous work has shown ...
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ISBN:
(纸本)0819425842
This paper outlines means of combining and reconciling concepts associated with Cohen's class of distributions and with the wavelet transform. Both have their assets and their liabilities. Previous work has shown that one can decompose any time-frequency distribution (TFD) in Cohen's class into a weighted sum of spectrogram. A set of orthogonal analysis windows which also have the scaling property in common with wavelets is proposed. Successful application of this theory offers very fast computation of TFDs, since very few analysis windows may be needed and fast algorithms can be used. In addition, the decomposition idea offers the possibility of shaping the analysis such that good local and global properties as well as a number of desirable TFD properties are retained. Finally, one may view the result in terms of conventional Cohen's class concepts or, alternatively, in terms of wavelet concepts and potentially combine powerful insights and concepts from both points of view. Preliminary results applied to radar backscatter are provided. Performance curves for several wavelet types are also provided.
This paper presents a system that combines NLP and hand-written rules for enhancing the text of authentic Web pages based on the needs of a specific language learner. It uses the Stanford CoreNLP system to process tex...
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ISBN:
(纸本)9781538638705
This paper presents a system that combines NLP and hand-written rules for enhancing the text of authentic Web pages based on the needs of a specific language learner. It uses the Stanford CoreNLP system to process texts, and applies handwritten rules for retrieving language information that is relevant according to a given Common European Framework of Reference for Languages (CEFR) level. After the text content of the Web page is processed, it is presented to the user with enhancements of various language structure. These enhancements are meant to draw the user's attention to linguistic structures that are present on the text, so that the reading activity does not encompass only the meaning of the text, but also serves as a reinforcement to language learning activities.
Blind source separation is an emerging field of fundamental research with a broad range of applications. It is motivated by practical problems that involve several source signals and several sensors. Each sensor recei...
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ISBN:
(纸本)0819425842
Blind source separation is an emerging field of fundamental research with a broad range of applications. It is motivated by practical problems that involve several source signals and several sensors. Each sensor receives an instantaneous linear mixture of the source signals. The problem of the blind source separation consists then of recovering the original waveforms of the sources without any knowledge of the mixture structure. So far, the problem of the blind source separation has been solved using statistical information available on the source signals. A blind source separation approach for non-stationary signals based on time-frequency representations (TFR) have been recently introduced by the authors (SPIE 1996). Herein, we generalize the TFR based blind source separation approach to arbitrary variables, including time and frequency. 'Spatial joint arbitrary variable distributions' are introduced and used for blind source separation via joint diagonalization techniques.
The determination of collision free grips is an important aspect of random bin picking, which describes the separation of unordered workpieces stored in bins by an industrial robot. Heuristic search algorithms are an ...
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ISBN:
(纸本)9781509060009
The determination of collision free grips is an important aspect of random bin picking, which describes the separation of unordered workpieces stored in bins by an industrial robot. Heuristic search algorithms are an appropriate approach to this problem. In this paper, we analyze the influence of relative height and lateral position of workpieces as well as orientation of tool center points on finding valid grips. From these results, we deduce heuristic functions, which can be used to improve the aforementioned heuristic search algorithms. Being able to reduce the calculation time for grip determination reduces overall cycle time and therefore makes bin picking more applicable for the producing industry.
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