The fundamental step in video content analysis is the temporal segmentation of video stream into shots, which is known as Shot Boundary Detection (SBD). The sudden transition from one shot to another is known as Abrupt Transition (AT), whereas if the transition occurs over several frames, it is called Gradual Transition (GT). A unified framework for the simultaneous detection of both AT and GT have been proposed in this article. The proposed method uses the multiscale geometric analysis of Non-Subsampled Contourlet Transform (NSCT) for feature extraction from the video frames. The dimension of the feature vectors generated using NSCT is reduced through principal component analysis to simultaneously achieve computational efficiency and performance improvement. Finally, cost efficient Least Squares Support Vector Machine (LS-SVM) classifier is used to classify the frames of a given video sequence based on the feature vectors into No-Transition (NT), AT and GT classes. A novel efficient method of training set generation is also proposed which not only reduces the training time but also improves the performance. The performance of the proposed technique is compared with several state-of-the-art SBD methods on TRECVID 2007 and TRECVID 2001 test data. The empirical results show the effectiveness of the proposed algorithm. 相似文献
Nano-TiO2 crystals showing visible light driven photocatalytic activity were synthesized by hydrothermal reaction in an ethanol-water mixture. The experiments were conducted to optimise the synthesis conditions for nano titania, in the range of temperature from 200 to 400 °C. X-ray diffraction depicted that the products obtained were anatase at 250 °C and above. For the products obtained at 250 °C, detailed analysis was conducted since it depicted high crystallinity with smallest particle sizes. Shape of the crystal was rounded rectangular with the size of 4 ± 1 nm to 7 ± 1 nm. The high-resolution transmission electron microscopy (HRTEM) revealed the existence of novel nano-twin structure in anatase grains and surface defects around the nanocrystals. Photocatalytic property was investigated for these undoped titania samples under UV and visible light. The nano twin structure, surface defects, and nano-meter size of the synthesized titania are believed to play a crucial role for the high catalytic activity. 相似文献
Functionalization of metal oxides nanomaterial by different organic and inorganic species could considerably enhance the electrochemical performance of a supercapacitor. Here, we have synthesized and functionalized ZnO nanoparticles (NPs) via organic compounds of E. cognate and then doped the synthesized nanomaterials by NiO following hydrothermal route involving the bioactive compounds. As synthesized ZnO@NiO was analyzed by field emission-scanning electron microscopy at nanoscale. The organic functional groups were delineated by X-ray photoelectron spectroscopy as well as by Fourier transform infrared spectroscopy. What is more, Tauc plot revealed drastically decreased band gap energy of ZnO@NiO to 2.48 eV resulting in an enhanced electrochemical properties. Therefore, organic framework derived ZnO@NiO nanomaterial was scrutinized as an electrode for supercapacitor by galvanostatic charge-discharge, cyclicvoltammetry and electrochemical impedance spectroscopy. ZnO@NiO electrode demonstrated specific capacitance of 185 Fg−1 by cyclicvoltammetry, proposing its potential towards supercapacitor due to nanoscale particles and incorporated C, O, and N atoms of organic compounds. 相似文献
Metallurgical and Materials Transactions A - The present study investigates the orientation dependence of deformation-induced martensite (DIM) transformation in carbide-free bainitic steel using... 相似文献
The role of energy in economic, social and ecological development of a country defines its significance in sustainable development. We propose here a method to classify a nation’s hydrocarbon development into one of five classes: (1) futuristic; (2) conforming; (3) sustainable; (4) unsustainable; or, (5) critical. K means clustering is a method of unsupervised classification in which the clusters cannot be labeled due to their lack of a class value. We propose a unique method to label unsupervised classes which is then used to divide the energy data of nations into five clusters. The labeled clusters are structured in an ID3 decision tree which provides a hierarchical structure to evaluate the hydrocarbon development in a given country. The results indicate some useful and interesting patterns in sustainability indicators. 相似文献
Boric acid is a weak inorganic acid type which is generally being used in glass, ceramics, detergents, agriculture, nuclear energy, and medicine fields, which has white crystal color and which can easily dissolve in water. Boric acid is being produced from colemanite which is a boron mineral having wide reserves in Turkey. In recent years, intense studies have been performed on the alternative usage areas of boric acid in Turkey. In this study, boric acid was used as a leaching reagent for the demineralization of coal with high ash content. For the accurate determination of the success of boric acid in dissolving mineral matter, first a series of leaching tests were performed with boric acid, and then studies for removing mineral matter with strong acids such as hydrofluoric acid (HF), HCl, and H2SO4 were performed. 相似文献
The aerodynamic characteristics of nine configurations of supersonic continuous deflectable nose guided missiles have been investigated. The optimized geometry was achieved based on the accuracy of confliction with constant target in ground to ground mission. The studied configurations consist of a spherical nose tip, a tangent ogive, one set of stabilizing tail fines and a cylindrical body whose midsection is flexible to form an arc of a circle. So the cylindrical body consists of a fixed part in the vicinity of the nose, middle flexible part and main body with stabilizers. The effects of fixed length (Fix = 0, 1.5, 3Cal) and flexible length (Flex = 1, 2.5, 5Cal) parameters on the aerodynamics and flight dynamics of guided missile have been studied. A code has been developed to solve full Navier-Stokes equations using finite volume and Runge-Kutta time stepping techniques and modified Baldwin-Lomax turbulence model. Multi-block technique was also used to solve the main body and fin parts flow fields. Further, a 3 degree of freedom code along with a pure pursuit guidance subroutine was developed to compare planar flight dynamics of missiles. It was found that although the missiles with bigger lengths for fixed and flex parts show more maneuverability, but this is not favorable for all missile missions as sometimes it decreases the confliction accuracy. Flight dynamic analysis shows that a change in initial launch angle may shift the favorite configuration. This means only the aerodynamic defined aim functions cannot completely supersede flight dynamic analysis in geometric optimization. Further, the thrust vector moment is an important portion of total control moment as it enhances the hitting accuracy and also decreases the importance of geometry.