The silicate speciation forms an important aspect of the structure of silicate melts, a subject of interest to both the earth and materials science communities. in this study, the Q(n) speciation of binary cesium sili...
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The silicate speciation forms an important aspect of the structure of silicate melts, a subject of interest to both the earth and materials science communities. in this study, the Q(n) speciation of binary cesium silicate glasses was studied by Raman spectroscopy. A method to extract the equilibrium constant from a set of Raman spectra is presented, and the least-squares optimization algorithm is given (in Supporting Information). Log(K), the equilibrium constant of the speciation reaction, 2Q(3) = Q(4) + Q(2), equals -2.72 +/- 0.11 at the glass transition. This extends the previously established correlation between log(K) and the inverse of the ionic radius of the network modifier to cesium. Copyright (C) 2009 John Wiley & Sons, Ltd.
This study is intended to provide a method to estimate the sea ice parameters in a nonlinear non-smooth thermodynamic system (NNTS) from the sea ice temperature measurements. A new optimization algorithm is constructe...
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This study is intended to provide a method to estimate the sea ice parameters in a nonlinear non-smooth thermodynamic system (NNTS) from the sea ice temperature measurements. A new optimization algorithm is constructed to estimate the coefficients describing the salinity and other two parameters in NNTS. Another simulation for sea ice temperature during different measurement period is operated. Results show that a better simulation of the temperature distribution is possible with the estimated parameters than with the experimental parameters. (C) 2008 Elsevier Masson SAS. All rights reserved.
A new airspace design concept, tube networks, could enable high-density operations with less air traffic control workload. To construct tubes optimally, it is necessary to identify the commonality of flight trajectori...
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A new airspace design concept, tube networks, could enable high-density operations with less air traffic control workload. To construct tubes optimally, it is necessary to identify the commonality of flight trajectories. This paper proposes a new strategy to cluster great circle flight trajectories for forming tubes. The Hough transform is applied to identify groups or clusters of great circle trajectories that could form the tube networks. The genetic algorithm is then applied to optimize the tube network. Results show that small deviations from great circle routes could yield tubes that accommodate significant traffic levels within feasible computational time.
In this paper the problem of designing a robust controller with given structure for a plant describing a drag-free satellite is addressed. From recent experiences in drag-free control design we first derive an uncerta...
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In this paper the problem of designing a robust controller with given structure for a plant describing a drag-free satellite is addressed. From recent experiences in drag-free control design we first derive an uncertain plant set representative of many drag-free missions with nonspherical test masses. The design plant is uncertain and a performance requirement is imposed on the absolute acceleration of the test mass along a measurement axis. The v-gap metric is first used to derive a simplified uncertain design plant. Then the main performance requirement is broken down into requirements on the uncertain closed loop behavior of the simplified system. The fulfillment of this new set of requirements guarantees robust achievement of the overall system goal. Then optimal single-input-single-output controllers are designed that robustly achieve the desired level of performance. The method proposed allows one to properly account for the uncertainties in the system retaining the decentralized structure (of the controller suggested by the peculiar features of the design plant.
Many spectroscopic applications of femtosecond laser pulses require properly-shaped spectral phase profiles. The optimal phase profile can be programmed on the pulse by adaptive pulse shaping. A promising optimization...
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Many spectroscopic applications of femtosecond laser pulses require properly-shaped spectral phase profiles. The optimal phase profile can be programmed on the pulse by adaptive pulse shaping. A promising optimization algorithm for such adaptive experiments is evolution strategy (ES). Here, we report a four fold increase in the rate of convergence and ten percent increase in the final yield of the optimization, compared to the direct parameterization approach, by using a new version of ES in combination with Legendre polynomials and frequency-resolved detection. Such a fast learning rate is of paramount importance in spectroscopy for reducing the artifacts of laser drift, optical degradation, and precipitation. (C) 2009 Optical Society of America
Satellites that use low-thrust propulsion systems for maneuvering, although efficient, can take a long time to complete significant orbit changes. Determining the nonlinear optimal controls for such multirevolution ma...
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Satellites that use low-thrust propulsion systems for maneuvering, although efficient, can take a long time to complete significant orbit changes. Determining the nonlinear optimal controls for such multirevolution maneuvers using the instantaneous orbital state dynamics can he riddled with numerical errors and are often subject to long computation times, due to the large number of discretization nodes required by the optimization algorithm. An approach to optimal control of an electrodynamic tether is examined using averaged orbital state dynamics as constraints instead of instantaneous dynamic constraints. A mean-square libration state is introduced in the dynamic model that captures the average of the out-of-plane libration of the tether. A sample long-term optimal orbit change maneuver of a librating electrodynamic tether subject to atmospheric drag is investigated. The method of averaging is employed to transform the optimal control problem from the time domain into Fourier space, in which the complex problem is significantly reduced to a Zermelo-type problem that is solved using a pseudospectral method. To validate the dynamic model of averaged states, the instantaneous states are propagated from the initial conditions using the resulting optimal controls.
. This study describes two types of algorithms for skid-to-turn unmanned aerial vehicles to plan paths between two waypoints under constant wind conditions. The first type of algorithm is a rigorous optimization algor...
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. This study describes two types of algorithms for skid-to-turn unmanned aerial vehicles to plan paths between two waypoints under constant wind conditions. The first type of algorithm is a rigorous optimization algorithm based on the Euler-Lagrange formulation with analytical integration of the path. The second type of algorithm is a fast algorithm describing the path by two circular arcs connected by a line segment or another circular are in the air mass frame, which is similar to the Dubins path. The latter algorithm is developed for actual airborne application, whereas the former algorithm is developed to check the quasi-optimality of the path calculated by the latter algorithm. We present a convergence proof of the latter algorithm under certain assumptions and its quasi-optimality in comparison with the former algorithm. Furthermore, the computational efficiency and the convergence reliability of the latter algorithm are demonstrated through numerical examples.
Nonspecific target binding (i.e., cross-hybridization) is a major challenge for interpreting oligonucleotide microarray results because it is difficult to determine what portion of the signal is due to binding of comp...
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Nonspecific target binding (i.e., cross-hybridization) is a major challenge for interpreting oligonucleotide microarray results because it is difficult to determine what portion of the signal is due to binding of complementary (specific) targets to a probe versus that due to binding of nonspecific targets. Solving this challenge would be a major accomplishment in microarray research potentially allowing quantification of targets in biological samples. Marcelino et al. recently described a new approach that reportedly solves this challenge by iteratively deconvoluting 'true' specific signal from raw signal, and quantifying ribosomal (rRNA) sequences in artificial and natural communities (i.e., "Accurately quantifying low-abundant targets amid similar sequences by revealing hidden correlations in oligonucleotide microarray data", Proc. Natl. Acad. Sci. 103, 13629-13634). We evaluated their approach using high-density oligonucleotide microarrays and Latin-square designed experiments consisting of 6 and 8 rRNA targets in 16 different artificial mixtures. Our results show that contrary to the claims in the article, the hidden correlations in the microarray data are insufficient for accurate quantification of nucleic acid targets in complex artificial target mixtures. (c) 2008 Elsevier B.V. All rights reserved.
A method of Course-Timetabling Problem is proposed based on immune genetic algorithm. Aimed at the flaws of the genetic algorithm, a method of immune genetic algorithm based on immune system theory and self-adaptation...
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ISBN:
(纸本)9781424435197
A method of Course-Timetabling Problem is proposed based on immune genetic algorithm. Aimed at the flaws of the genetic algorithm, a method of immune genetic algorithm based on immune system theory and self-adaptation of the genetic operator was intruded. This algorithm could solve the problem of premature convergence of genetic algorithm and assure the diversity of the colony. The simulated results show that the effect of classes arrangement based on immune genetic algorithm was pretty good and this method can quickly and efficiently search for the global solution.
3D model is used for vision based vehicle location. An improved Hausdorff distance based on edge-strength is proposed to evaluate the similarity between 3D model projection and image feature, and to establish location...
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ISBN:
(纸本)9780769535579
3D model is used for vision based vehicle location. An improved Hausdorff distance based on edge-strength is proposed to evaluate the similarity between 3D model projection and image feature, and to establish location optimization function In order to avoid local minimum during optimization, estimation of distribution algorithm concerning related multi-variables is used. The relationship between matching parameters are described with a probability model, and the distribution of parameter evolves towards the direction of dominant character through probability model learning and the corresponding operation, which is proposed to solve the problem of overmany iteration and slow constringency velocity. The experiments show that the optimal matching parameters between 3D model and 2D image feature can be found accurately and efficiently, and the algorithm outperforms other approaches in both accuracy and rapidity.
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