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Commonly shape and material optimization for complex structures having complicated boundary and loading conditions requires FE analysis in order to determine accurately enough (especially for composite structures) objective functions. The solutions of such class of problems become difficult as we use probabilistic algorithms. Therefore, a general method using the Markov chain and stochastic equations...
We present here an optimized shape of an acoustical chamber for gaseous photoacoustic spectroscopy needs. Since the relative positioning of the linear sound source -a laser beam- and the microphone presents few symmetry, 3D topology optimization was used here in order to derive non-axisymmetric shapes. The methodology implemented with COMSOL Multiphysics maximizes the retrieved sound pressure at the...
Chinese calligraphy style evaluation and generation are important to the aim of cultural heritage preservation. Character skeleton extraction is a key preprocessing step and most existing algorithms suffer from drawbacks of non-single pixel width, bifurcation etc. In this paper, an optimization process is proposed to overcome these drawbacks to some extent. It gets the provisional skeleton using a...
We present a variant of the regularized dual averaging (RDA) algorithm for stochastic sparse optimization. Our approach differs from the previous studies of RDA in two respects. First, a sparsity-promoting metric is employed, originated from the proportionate-type adaptive filtering algorithms. Second, the squared-distance function to a closed convex set is employed as a part of the objective functions...
Restoration of shredded signals remains a relevant and significant challenge in archaeological and forensic efforts. In this work, we present a novel approach for reconstruction of shredded signals (including text documents and images) within a context of general multidimensional sparse signals. To this end, we present a generic efficient non-convex optimization method that employs iterative sparsity...
In this work, the synthesis of clustered antenna array architectures is addressed. The sub-arraying problem is formulated as a tiling one, and solved considering tiles of rectangular shape (domino). An optimization strategy is proposed to deals with medium/large array apertures, obtaining tiling configurations that are optimal in terms of aperture efficiency and sidelobe level (SLL). A simple example...
In this paper we propose a novel approach to identify and label the structural elements of furniture e.g. wardrobes, cabinets etc. Given a furniture item, the subdivision into its structural components like doors, drawers and shelves is difficult as the number of components and their spatial arrangements varies severely. Furthermore, structural elements are primarily distinguished by their function...
3D field shaping is a canonical problem in wave physics that could impact next generation of therapeutic systems. In this framework, we present an innovative and effective strategy that relies on the convex relaxation of the original NP hard problem by taking inspiration from the optimal constrained power focusing method. The formulation presented in this paper in terms of convex programming allows...
The paper introduces an accurate solution to dense orthographic Non-Rigid Structure from Motion (NRSfM) in scenarios with severe occlusions or, likewise, inaccurate correspondences. We integrate a shape prior term into variational optimisation framework. It allows to penalize irregularities of the time-varying structure on the per-pixel level if correspondence quality indicator such as an occlusion...
In this paper, we show how to minimise a quadratic function on a set of orthonormal matrices using an efficient semidefinite programming solver with application to dense non-rigid structure from motion. Thanks to the proposed technique, a new form of the convex relaxation for the Metric Projections (MP) algorithm is obtained. The modification results in an efficient single-core CPU implementation...
This paper presents the design and performance of a waveguide septum polarizer where the longitudinal profile of the septum blade is shaped with Legendre polynomials. A performance comparison with a conventional septum polarizer based on a blade with a stepped profile is performed at Ka-band (27.5–30.0 GHz) to show the merit of the proposed profile shaping. Preliminary results indicate an increase...
Compiler optimizations discover facts about program behavior by querying static analysis. However, developing or extending precise analysis is difficult. Some prior works implement analysis with a single algorithm, but the algorithm becomes more complex as it is extended for greater precision. Other works achieve modularity by implementing several simple algorithms and trivially composing them to...
We proposed a topology optimization method that incorporates the concept of cluster and cleaning method in Genetic algorithm (GA). This method can design a rotor structure from the empty space, which has high output power and less permanent magnet volume. In this paper, the effect of strength of the cleaning method on the obtained rotor structure is investigated. Using the optimal strength of the...
The double-sided slotted permanent magnet synchronous linear motor (PMSLM) has the advantages of high thrust density and high power factor. This paper adopted the structure of tooth-shifted double sides and obtained the influence law on thrust characteristic under different tooth-shifted distance by using finite element simulation. It also compared tooth-shifting and pole-shifting. Combining the orthogonal...
Recently, one of the most important problems is energy shortage. Therefore, it is required the high efficiency electromagnetic device like motors. One of them is interior permanent magnetic synchronous motor (IPMSM). It has a high degree of freedom of shape design because permanent magnets are placed in the interior of a rotor. This paper presents optimal design method of a rotor in IPMSM by differential...
This paper proposes the design of antipodal Vivaldi antennas using the kernel regression method. The kernel regression is applied for training a cost function model to predict the next sample with improved cost values, and the information of the predicted sample is employed to re-train the model. This process is repeated until the cost value converges to our design goal. The shapes of the tapered...
The results of study of optimal geometrical parameters of magnetic sensor, which is used in the automatic machine control, are presented. The initial configuration was the coil with cylindrical core. Optimization criterion was intended to increasing the sensitivity of the sensor in the work space.
Cloud is a common element of the sky and plays an important role in outside scene modeling. In this paper, a novel cloud surface shape estimation method from an image is proposed based on Shape from Shading(SFS). Shape from shading(SFS) algorithm is inherently ill-posed for the one image, which means that no shape or more shapes may synthetic the same input image. To estimate the cloud surface shape...
Existing distance metric learning methods define an objective function and seek a distance metric (or equivalently a projection) that minimizes it. In this paper, we propose a different approach that illustrates how to formulate distance metric learning as a regression problem. First, the objective function is minimized to learn target representations. Then, a regression method is employed to learn...
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