With the advantages such as high security and far responding distance, the passive location has a broad application in military and civil domains such as radar and aerospace. However, most of the current passive locat...
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With the advantages such as high security and far responding distance, the passive location has a broad application in military and civil domains such as radar and aerospace. However, most of the current passive location methods are based on the framework of the probability theory and cannot be used to deal with fuzzy uncertainty in the passive location systems. Though the fuzzy Kalman filter can be used in the uncertainty systems, it could not deal with the abrupt change of state like the maneuvering target which will lead to the filter divergence. Therefore, in order to track the maneuvering target in the fuzzy passive system, we proposed a robust fuzzy extended Kalman filter based on the orthogonality principle and the fuzzy filter in the paper. Conclusion can be made based on the simulation result that this new approach is more precise and more robust than the fuzzy filter.
We provide an algorithm for computing the centered Hausdorff measures of self-similar sets satisfying the strong separation condition. We prove the convergence of the algorithm and test its utility on some examples. (...
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We provide an algorithm for computing the centered Hausdorff measures of self-similar sets satisfying the strong separation condition. We prove the convergence of the algorithm and test its utility on some examples. (C) 2011 Elsevier Ltd. All rights reserved.
This paper gives algorithms for determining real-valued univariate unimodal regressions, that is, for determining the optimal regression which is increasing and then decreasing. Such regressions arise in a wide variet...
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This paper gives algorithms for determining real-valued univariate unimodal regressions, that is, for determining the optimal regression which is increasing and then decreasing. Such regressions arise in a wide variety of applications. They are shape-constrained nonparametric regressions, closely related to isotonic regression. For unimodal regression on n weighted points our algorithm for the L-2 metric requires only Theta(n) time, while for the L-1 metric it requires Theta(n log n) time. For unweighted points our algorithm for the L. metric requires only Theta(n) time. All of these times are optimal. Previous algorithms were for the L-2 metric and required Omega(n(2)) time. All previous algorithms used multiple calls to isotonic regression, and our major contribution is to organize these into a prefix isotonic regression, determining the regression on all initial segments. The prefix approach reduces the total time required by utilizing the solution for one initial segment to solve the next. (C) 2008 Elsevier B.V. All rights reserved.
Using the dynamic properties of fractional-order Duffing system, a sequential parameter identification method based on differential evolution optimization algorithm is proposed for the fractional-order Duffing system....
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Using the dynamic properties of fractional-order Duffing system, a sequential parameter identification method based on differential evolution optimization algorithm is proposed for the fractional-order Duffing system. Due to the step by step parameter identification method, the dimension of parameter identification of each step is greatly reduced and the search capability of the differential evolution algorithm has been greatly improved. The simulation results show that the proposed method has higher convergence reliability and accuracy of identification and also has high robustness in the presence of measurement noise.
Covalent modifications on therapeutic proteins are traditionally monitored by chromatographic techniques, which quantify limited number of protein modifications at a time. In this report, computer algorithms for autom...
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Covalent modifications on therapeutic proteins are traditionally monitored by chromatographic techniques, which quantify limited number of protein modifications at a time. In this report, computer algorithms for automated analyses of liquid chromatography/tandem mass spectrometry (LC/MS/MS) data for large-scale identification and quantification of known and unknown modifications are described. Peptide identification is achieved by comparing the experimental fragmentation spectrum to the predicted spectrum of each native or modified peptide. Peak areas of related peptide ions under their selected-ion chromatograms (SIC) are used for relative quantification of modified peptides. A matched window function is used to generate SIC for more reliable quantification. In an LC/MS/MS analysis of a tryptic digestion of an IgG2 monoclonal antibody, 1712 peptide ions were identified with a false-discovery rate of similar to 0.4%, and 227 modifications were identified and quantified. The accuracy of the mass spectrometry-based quantification is evaluated by comparing the abundance of different glycoforms determined by mass spectrometry to that determined by a fluorescence-based chromatography method. This large-scale method may potentially replace many chromatographic methods for assessing the quality attributes of therapeutic proteins.
Inspired by the advanced capabilities of fish-like swimmers, we seek a greater understanding of the hydrodynamic mechanisms they employ. Borrowing tools from geometric mechanics, we develop a large-amplitude gait desi...
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Inspired by the advanced capabilities of fish-like swimmers, we seek a greater understanding of the hydrodynamic mechanisms they employ. Borrowing tools from geometric mechanics, we develop a large-amplitude gait design technique for self-propelling deformable swimmers in potential flow and Stokes flow. Additionally, a heuristically-developed control algorithm is implemented to nearly optimize thrust-generation for a swimmer moving through its own nearly-periodic vortex wake.
This paper describes the experimental comparison among four model-based control algorithms on a direct-drive robotic arm. We present experimental results of the following controllers: Computed-Torque control, PD + con...
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This paper describes the experimental comparison among four model-based control algorithms on a direct-drive robotic arm. We present experimental results of the following controllers: Computed-Torque control, PD + control, PD control with computed feedforward and PD control. All controllers include Coulomb and viscous friction compensation as well as cancellation of gravitational torques. They are tested under common trajectory specification and performance index. (C) 2000 Elsevier Science Ltd. All rights reserved.
By exploiting the direction of arrival (DoA) information of azimuth ambiguity, an innovative algorithm for the adaptive suppression of azimuth ambiguity for multichannel synthetic aperture radar (SAR) wide-swath imagi...
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By exploiting the direction of arrival (DoA) information of azimuth ambiguity, an innovative algorithm for the adaptive suppression of azimuth ambiguity for multichannel synthetic aperture radar (SAR) wide-swath imaging is presented. It firstly estimates the DoA value of each azimuth component within a Doppler cell using the efficient noise subspace-based iterative estimation technique. Then the spatial filter for sequentially extracting the desired azimuth component is derived, which is designed to be used with the newly estimated DoA information within each Doppler bin. Finally, the azimuth ambiguities can be suppressed via the implementation of spatial filtering. The proposed approach is robust to aircraft velocity errors, and its effectiveness is validated via simulation results.
We are proposing a multiresolution representation which uses a subdivision surface as a smooth base surface with respect to which a high resolution mesh is defined by normal displacement. While this basic representati...
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We are proposing a multiresolution representation which uses a subdivision surface as a smooth base surface with respect to which a high resolution mesh is defined by normal displacement. While this basic representation is quite straightforward, our actual contribution ties in the automatic generation of such a representation. Given a high resolution mesh, our algorithm is designed to derive a subdivision control mesh whose structure is properly adjusted and aligned to the major geometric features. This implies that the control vertices of the subdivision surface not only control globally smooth deformations but in addition that these deformations are meaningful in the sense that their support and shape correspond to the characteristic structure of the input mesh. This is achieved by using a new decimation scheme for general polygonal meshes (not just triangles) that is based on face merging instead of edge collapsing. A face-based integral metric makes the decimation scheme very robust such that we can obtain extremely coarse control meshes which in turn allow for deformations with large support.
In this paper, mobile robot navigation on a 3D terrain with a single obstacle is addressed. The terrain is modelled as a smooth, complete manifold with well-defined tangent planes and the hazardous region is modelled ...
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In this paper, mobile robot navigation on a 3D terrain with a single obstacle is addressed. The terrain is modelled as a smooth, complete manifold with well-defined tangent planes and the hazardous region is modelled as an enclosing circle with a hazard grade tuned radius representing the obstacle projected onto the terrain to allow efficient path-obstacle intersection checking. To resolve the intersections along the initial geodesic, by resorting to the geodesic ideas from differential geometry on surfaces and manifolds, we present a geodesic-based planning and replanning algorithm as a new method for obstacle avoidance on a 3D terrain without using boundary following on the obstacle surface. The replanning algorithm generates two new paths, each a composition of two geodesics, connected via critical points whose locations are found to be heavily relying on the exploration of the terrain via directional scanning on the tangent plane at the first intersection point of the initial geodesic with the circle. An advantage of this geodesic path replanning procedure is that traversability of terrain on which the detour path traverses could be explored based on the local Gauss-Bonnet Theorem of the geodesic triangle at the planning stage. A simulation demonstrates the practicality of the analytical geodesic replanning procedure for navigating a constant speed point robot on a 3D hill-like terrain.
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