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Smart Structures and Materials 2003 Conference

作者： Zuo, L Nayfeh, SA MIT Dept Mech Engn Cambridge MA 02139 USA

ISBN: (纸本)0819448575

The characteristics of multiple tuned-mass dampers (MTMDs) attached to a single-degree-of-freedom primary system have been examined by many researchers, and several papers have included some parameter optimization. in this paper, we propose an efficient numerical algorithm to optimize the stiffness and damping of each of the tuned-mass dampers (TMDs) in such a system directly. We formulate the parameter optimization as a decentralized H2 control problem where the block-diagonal feedback gain matrix is composed of the stiffness and damping coefficients of the TMDs. The gradient of the root-mean-square (RMS) response with respect to the design parameters is evaluated explicitly, and the optimization can be carried out efficiently. The effects of the mass distribution, number of dampers, total mass ratio, and uncertainties in system parameters are studied. Numerical results indicate that the optimal designs have neither uniformly spaced tuning frequencies nor identical damping coefficients, and that optimization of the individual parameters in the MTMD system yields a substantial improvement in performance. We also find that the distribution of mass among the TMDs has little impact on the performance of the system provided that the stiffness and damping can be individually optimized.

关键词： Solids Lithium Control systems Yield improvement algorithm development Analytical research Feedback control Matrices Mechanical engineering Smart materials

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Remote resupply systems for unmanned FCS-related vehicles

Remote resupply systems for unmanned FCS-related vehicles

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Conference on Unmanned Ground Vehicle Technology V

作者： Murphy, R Gonzalez, N Fitz-Coy, N Papila, N Shyy, W Univ S Florida Ctr Robot Assisted Search & Rescue Tampa FL 33620 USA

ISBN: (纸本)0819449423

This paper summarizes a study on refueling and rearming FCS-related vehicles in the field. In keeping with the FCS philosophy, the resupply process should be unmanned. For the purposes of the study, a resupply (RS) system is defined as an autonomous robotic platform, which interacts with a combat vehicle (CV). The purpose of the interaction is transfer of liquid fuel and/or ammunition. The RS may be capable of providing both the fuel and the ammunition simultaneously, or there may be separate resupply vehicles, each dedicated to one consumable. The CV may be resupplied while on-station and operational or may be taken out of service and moved to a resupply point. The study proposed a resupply system, which consists of two RS vehicles (i.e., separate vehicles for fuel and ammunition) to refuel the CV. Four families of scenarios were considered: the RS moves to the CV ("door to door"), the RS and CV both move ("rendezvous"), the CV move the RS ("filling station"), and the CV move to a pod dropped nearby. The "door to door" scenario was rated the most feasible, with the rendezvous scenario a close second. The study ascertained that RS vehicles using a robotic manipulator for the transfer mechanism is based on best engineering practices and constitute a low risk design. The required level of autonomy to accomplish resupply is teleoperation, though a mixed-initiative approach poses relatively low risk. A teleoperator or simple mixed-initiative system can be completed in 3 years, and offers significant performance benefits. Full autonomy was determined to be too high risk, but mixed-initiative work could serve as a basis for evolving to full autonomy. The study also considered the impact of emerging technologies on resupply. The key technical risks in ascending order of investment priority are: platform design, munitions transfer mechanism, and human-robot interaction (HRI). The platform design and munitions transfer mechanism are lower risk than HRI, which is a relatively

关键词： Remote sensing Sensors Robotics Control systems algorithm development Fluorescence correlation spectroscopy Liquids Prototyping Telecommunications Navigation systems

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False alarm reduction by the And-ing of multiple multivariate Gaussian classifiers

False alarm reduction by the And-ing of multiple multivariat...

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Conference on Detection and Remediation Technologies for Mines and Minelike Targets VIII

作者： Dobeck, GJ Cobb, JT USN Ctr Surface Warfare Coastal Syst Stn Dahlgren Div Panama City FL 32407 USA

ISBN: (纸本)0819449490

The high-resolution sonar is one of the principal sensors used by the Navy to detect and classify sea mines in minehunting operations. For such sonar systems, substantial effort has been devoted to the development of automated detection and classification (D/C) algorithms. These have been spurred by several factors including (1) aids for operators to reduce work overload, (2) more optimal use of all available data, and (3) the introduction of unmanned minehunting systems. The environments where sea mines are typically laid (harbor areas, shipping lanes, and the littorals) give rise to many false alarms caused by natural, biologic, and man-made clutter. The objective of the automated D/C algorithms is to eliminate most of these false alarms while still maintaining a very high probability of mine detection and classification (PdPc). In recent years, the benefits of fusing the outputs of multiple D/C algorithms have been studied. We refer to this as algorithm Fusion. The results have been remarkable, including reliable robustness to new environments. This paper describes a method for training several multivariate Gaussian classifiers such that their And-ing dramatically reduces false alarms while maintaining a high probability of classification. This training approach is referred to as the Focused- Training method. This work extends our 2001-2002 work where the Focused-Training method was used with three other types of classifiers: the Attractor-based K-Nearest Neighbor Neural Network (a type of radial-basis, probabilistic neural network), the Optimal Discrimination Filter Classifier (based linear discrimination theory), and the Quadratic Penalty Function Support Vector Machine (QPFSVM). Although our experience has been gained in the area of sea mine detection and classification, the principles described herein are general and can be applied to a wide range of pattern recognition and automatic target recognition (ATR) problems.

关键词： Feature selection Matrices Naval mines Detection and tracking algorithms Mining Land mines algorithm development Automatic target recognition Image classification Neural networks

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Source adaptive blind source separation: Gaussian models and sparsity

Source adaptive blind source separation: Gaussian models and...

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Wavelets - Applications in Signal and Image Processing X Conference

作者： Pham, DT Cardoso, JF Lab Modelisat & Calcul F-38041 Grenoble 9 France

ISBN: (纸本)0819450804

Using the time-frequency (or -scale) diversity of the source processes allows the blind source separation problem to be tackled within Gaussian models. In this work, we show that this approach amounts to minimizing a certain sparseness criterion for the energy distribution of the source over the time-frequency (or -scale) plane. We also explore the link between independence and sparsity and shows that other sparsity criteria (some examples of which are provided) can be used. Further, we introduce an adaptive method which tries to find the best sparse representation of the. source energy in order to exploit the sparsity in a most efficient way. An algorithm, adapted from that of Coifman and Wickerhauser has been developed for this end. Finally a simulation example has been given.

关键词： Chemical species Time-frequency analysis algorithm development Error analysis Matrices Statistical analysis Signal processing Statistical modeling Stochastic processes Wavelets

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Binary matrices, decomposition and multiply-add architectures

Binary matrices, decomposition and multiply-add architecture...

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Conference on Image Processing - algorithms and Systems II

作者： Sarukhanyan, H Agaian, S Astola, J Egiazarian, K NAS Armenia Inst Informat & Automat Problems Yerevan Armenia

ISBN: (纸本)0819448141

Binary matrices or (+/-1)-matrices have found numerous applications in coding, signal processing, and communications. In this paper, a general and efficient algorithm of decomposition of binary matrices is developed. As a special case, Hadamard matrices are considered. The proposed scheme requires no zero padding of the input data. The problem of the construction of 4n-point Hadamard transform is related to the Hadamard problem: the question of existence of Hadamard matrices. (It is not proved whether for every integer n, there exists an orthogonal 4n x 4n matrix with elements +/-1). The number of real operation in developed algorithms is reduced from O(N-2) to O(Nlog(2)N). Comparisons revealing the efficiency of the proposed algorithms with respect to the known ones are given. In particular, it is demonstrated that, in typical applications, the proposed algorithm is more efficient than the conventional Walsh Hadamard transform. Note that for Hadamard matrices of orders greater than or equal to 96 the general algorithm is more efficient than the classical Walsh-Hadamard transform whose order is a power of two. The algorithm has a simple and symmetric structure. The results of numerical examples are presented.

关键词： Matrices algorithm development Binary data Ytterbium Signal processing algorithms Radon Detection and tracking algorithms Image processing Reconstruction algorithms

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Resolution enhancement and sampling with wavelets and footprints

Resolution enhancement and sampling with wavelets and footpr...

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Wavelets - Applications in Signal and Image Processing X Conference

作者： Dragotti, PL Vetterli, M Univ London Imperial Coll Sci Technol & Med London SW7 2BT England

ISBN: (纸本)0819450804

In this paper, we consider classes of not bandlimited signals, namely, streams of Diracs and piecewise polynomial signals, and show that these signals can be sampled and perfectly reconstructed using wavelets as sampling kernel. Due to the multiresolution structure of the wavelet transform, these new sampling theorems naturally lead to the development of a new resolution enhancement algorithm based on wavelet footprints.(2) Preliminary results show that this algorithm is also very resilient to noise.

关键词： Wavelets Resolution enhancement technologies Reconstruction algorithms algorithm development Wavelet transforms algorithms Electronic filtering Filtering (signal processing) Interference (communication) Signal to noise ratio

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Fusion of acoustic/seismic and GPR detection algorithms

Fusion of acoustic/seismic and GPR detection algorithms

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Conference on Detection and Remediation Technologies for Mines and Minelike Targets VIII

作者： Gader, PD Wilson, JN Wang, T Keller, JM Lee, WH Grandhi, R Hocaoglu, AK McElroy, J Univ Florida Dept Comp & Informat Sci & Engn Gainesville FL 32611 USA

ISBN: (纸本)0819449490

A variety of sensors have been investigated for the purpose of detecting buried landmines in outdoor environments. Mines with little or no metal are very difficult to detect with traditional mine detection systems. Ground Penetrating Radar (GPR) sensors have shown great promise in detecting low metal mines and can easily detect metal mines. Unfortunately, it can still be difficult to detect low-metal mines with GPR due to very low contrast between the mine and the surrounding medium. Acoustic-seismic systems were proposed by Sabatier ***. and have also shown great promise in detecting low metal mines. There are now a wealth of references that discuss these systems and algorithms for processing data from these systems. Therefore, they will not be discussed in detail here. In fact, low-metal mines are easier to detect than metal mines with this acoustic-seismic systems. Low metal mines that are difficult for a GPR to detect can be quite easy to detect with acoustic-seismic systems. Sensor fusion with these sensors is of interest since together they can find a broader range of mines with relative ease. The algorithmic challenge is to determine a strategy for combining the multi-sensor information in a way that can increase the probability of detection without increasing the false alarm rate significantly. In this paper, we investigate fusion of information obtained from GPR and acoustic-seismic on real data measured from a mine lane containing three types of buried landmines and also areas containing no landmines. algorithms are applied to data acquired from each sensor and confidence values are assigned to each location at which a measurement is made by each sensor. The GPR is used as a primary sensor. At each location at which the GPR algorithm declares an alarm, a modified likelihood-based approach is used to increase the GPR derived confidence if the likelihood that a mine is present, defined by the acoustic-based confidence, is larger than the likelihood that no

关键词： General packet radio service Acoustics Mining Sensors Land mines Metals Palladium Detection and tracking algorithms algorithm development Data acquisition

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Exposure-focus critical dimension feedback control in 300mm manufacturing technologies

Exposure-focus critical dimension feedback control in 300mm ...

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Conference on Advanced Process Control and Automation

作者： Narendra, A Carson, S Morrison, C Intel Corp Hillsboro OR 97124 USA

ISBN: (纸本)0819448494

Control of DCCDs (Develop Check Critical Dimension) is a key aspect of successfully manufacturing semiconductors at Intel. DCCD control was formerly achieved through manual adjustments of the exposure dose on the tool to account for the known effects of non-stationary tool/process drift. An automated application EFCC (Exposure-Focus CD Control) was developed at Intel, to create a robust algorithm and automated implementation, replacing the manual adjustment process. The EFCC algorithm uses DCCD summary measurements as the feedback to the stepper. At the stepper, the exposure setting is adjusted to correct for non-stationary tool/process drift. A weighted average of data from previous lots is used to determine the recommended exposure dose settings. The feedback scheme weights prior lots using a combination of traditional EWMA based weighting and within lot (across sites on wafer) variance based weighting. The EFCC implementation has benefits in increased Cpk, reduced rework, continuous adjustment. Furthermore, as this is an automated control solution, it can be easily extended to support more sophisticated adjustment algorithms.

关键词： Manufacturing Data modeling Process control Process modeling algorithm development Control systems Feedback control Correlation function Detection and tracking algorithms Semiconductor manufacturing

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development and validation of altimeter wind speed algorithms using an extended collocated buoy/Topex dataset

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IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 2002年第2期40卷 251-260页

作者： Gommenginger, CP Srokosz, MA Challenor, PG Cotton, PD Southampton Oceanog Ctr James Rennell Div Ocean Circulat & Climate Southampton SO14 3ZH Hants England

The development and validation of altimeter wind speed algorithms is investigated following the collation of the largest dataset to-date of coincident altimeter/buoy open ocean measurements. Nonlinear relationships between buoy wind and Topex backscatter are fitted to the 4500 points dataset using least-squares (LSQ). The addition of altimeter significant wave height (SWH) information causes a small but significant reduction of about 10% in root-mean-square (rms) error. The new LSQ algorithms yield significant improvement of the global wind speed bias and rms error compared to earlier models, but describe the wind to backscatter relationship poorly at extreme wind speeds. Best results are obtained with the Gourrion et al. (2000) model, improving on the Witter and Chelton (WC91) (1991) model used operationally. A residual dependence on sea state persists in all wind algorithms, which underestimate winds in young sea conditions on average by 1-1.5 m/s. A case study confirms that ordinary LSQ attribute excessive weight to the peak of the wind speed histogram and yield algorithms with poor performance at extreme winds. Measurement errors are shown to greatly influence the fitted models performance, as accounting for normally distributed errors in both altimeter and buoy measurements with orthogonal distance regressions (ODRs) yields significant improvements. Hence, algorithms developed from relatively small collocated datasets (few thousand points) may perform as well as models developed from much larger datasets (tens of thousands of points) given adequate treatment of errors. However, it is anticipated that the ultimate accuracy of wind speed algorithms is still dependent on the quality of the fitted datasets.

关键词： algorithm development altimeter wind speed collocated dataset wave age

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Comparative study on morphological skeletonization and fuzzy medial axis transformation

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JOURNAL OF ELECTRONIC IMAGING 2002年第1期11卷 38-49页

作者： Jan, SR Hsueh, YC MingHsin Inst Technol Dept Informat Management Hsinchu 304 Taiwan Natl Chiao Tung Univ Dept Comp & Informat Sci Hsinchu 300 Taiwan

In this paper, we make a comparative study on morphological skeletonization (MSK) and fuzzy medial axis transformation (FMAT), Methods have been proposed to construct convex FMAT from the morphological skeleton points and to translate FMAT to MSK respectively. For the case of translating MSK to convex FMAT the experimental results reveal that the combination of the proposed method and the redundant removal algorithm is very effective. Especially, the combined method is faster than the original method for constructing convex FMAT of smoothed images. (C) 2002 SPIE and IST.

关键词： Fuzzy logic Binary data algorithm development Superposition Computing systems Digital image processing Mathematical morphology Information science Information technology Machine vision

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