The first step in a video indexing process is the segmentation of videos into meaningful parts called shots. In this paper we present a formal model of the video shot segmentation process. Starting from a mathematical characterization of the most common transition effects, a video segmentation algorithm capable to detect both abrupt and gradual transitions is proposed. The proposed algorithm is based on the computation of an arbitrary similarity measure between consecutive frames of a video. The algorithm has been tested adopting a similarity metric based on the Animate Vision theory and results have been reported. 相似文献
Liquid–liquid interfaces are highly dynamic and characterized by an elevated interfacial tension as compared to solid–liquid interfaces. Therefore, they are gaining an increasing interest as viable templates for ordered assembly of molecules and nanoparticles. However, liquid–liquid interfaces are more difficult to handle compared to solid–liquid interfaces; their intrinsic instability may affect the assembly process, especially in the case of multiple deposition. Indeed, some attempts have been made in the deposition of polymer multilayers at liquid–liquid interfaces, but with limited control over size and stability. This study reports on the preparation of an ultrastable liquid–liquid interface based on an O/W secondary miniemulsion and its possible use as a template for the self‐assembly of polymeric multilayer nanocapsules. Such polymer nanocapsules are made of entirely biodegradable materials, with highly controlled size—well under 200 nm—and multi‐compartment and multifunctional features enriching their field of application in drug delivery, as well as in other bionanotechnology fields. 相似文献
Metabolic P (MP) grammars are a particular class of multiset rewriting grammars introduced in the MP theory for modelling metabolic processes. In this paper, a new algebraic formulation of inverse problems, based on MP grammars and Kronecker product, is given, for further motivating the correctness of the LGSS (Log-Gain Stoichiometric Stepwise) algorithm, introduced in 2010s for solving inverse problems in the MP framework. At the end of the paper, a section is included that introduces the problem of multicollinearity, which could arise during the execution of LGSS, and that defines an algorithm, based on a hierarchical clustering technique, that solves it in a suitable way. 相似文献
A micromachined chemoresistive gas sensor was studied from the point of view of heat distribution and thermal dissipation: this innovative device for environmental pollutant gas monitoring, is based on a sensitive film of semiconductor metal oxides, kept in temperature by a platinum resistor. In order to avoid electrical interactions between the film heater and the contacts for the film reading, the heater is driven by a square wave, and the film is read when no voltage is provided. Since the working temperature of the film is extremely important for its operation, it is crucial to maintain the temperature fluctuations within few degrees; to this end, in this work we study the heat distribution and dissipation of such a device, aiming to set a proper heating frequency, which will assure a right stability of the working temperature. 相似文献
A distillation process for the production of hyperazeotropic ethanol from a dilute wine obtained from the fermentation of biomass has been studied. This process utilizes the coupling of a soft preconcentration stage and of a dehydration stage based on the salting-out effect produced by calcium chloride on the ethanol in an aqueous solution, with the disappearance of the azeotrope. The salt is employed in a close cycle, due to the presence of a regeneration stage, therefore no consumption of calcium chloride is noticed.
The distillation process utilizes one column consisting of two sections operating at different pressures in order to reach an efficient heat recovery.
In this paper, a simplified flow-sheet of the process and the principal operating conditions of the distillation column are illustrated. When compared with other processes, conventional or under development, this one is characterized by the promising reduction of the specific energy requirement.
The operating conditions chosen for the distillation with salt have been experimentally checked using a laboratory column running continuously with calcium chloride as salting-out agent. Moreover, the experiments confirmed the reliability of the mathematical model of the process. Further experiments are in progress with the aim of utilizing a mixture of salts which can be fed from the bottom of the dehydration section back to the fermentor, so that the salt regeneration stage can be reduced. 相似文献
Particle tracking in turbulent flows in complex domains requires accurate interpolation of the fluid velocity field. If grids are non-orthogonal and curvilinear, the most accurate available interpolation methods fail. We propose an accurate interpolation scheme based on Taylor series expansion of the local fluid velocity about the grid point nearest to the desired location. The scheme is best suited for curvilinear grids with non-orthogonal computational cells. We present the scheme with second-order accuracy, yet the order of accuracy of the method can be adapted to that of the Navier-Stokes solver.An application to particle dispersion in a turbulent wavy channel is presented, for which the scheme is tested against standard linear interpolation. Results show that significant discrepancies can arise in the particle displacement produced by the two schemes, particularly in the near-wall region which is often discretized with highly-distorted computational cells. 相似文献