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11.
Feature tracking and matching in video using programmable graphics hardware   总被引:2,自引:0,他引:2  
This paper describes novel implementations of the KLT feature tracking and SIFT feature extraction algorithms that run on the graphics processing unit (GPU) and is suitable for video analysis in real-time vision systems. While significant acceleration over standard CPU implementations is obtained by exploiting parallelism provided by modern programmable graphics hardware, the CPU is freed up to run other computations in parallel. Our GPU-based KLT implementation tracks about a thousand features in real-time at 30 Hz on 1,024 × 768 resolution video which is a 20 times improvement over the CPU. The GPU-based SIFT implementation extracts about 800 features from 640 × 480 video at 10 Hz which is approximately 10 times faster than an optimized CPU implementation.  相似文献   
12.
Unmanned Aircraft (UA) have become an integral part of the present-day joint air operations. UA have potential to be employed across the full spectrum of Air Force functions. On the other hand, UA technology could be a subject of an asymmetric use by state actors in high or low density conflict, and/or by non-state actors in many ways including terrorism, drug smuggling, and limited attack with unconventional payloads i.e. biological or chemical agents. Therefore countering the threat associated with the hostile UA use could be necessary in the future. First part of the research revealed that UA can be a threat in the future. In the second part of the research, the SWOT (Strengths-Weaknesses-Opportunities-Threats) analysis supplemented with the Tree analysis (SWOT+Tree) provided a broader look for investigating the factors related to hostile UA use analytically. In literature, there is little information about the concepts for CUAOPS. The final goal of the paper is to find possible solutions and means for a better understanding of the nature of CUAOPS.  相似文献   
13.
    
Reduced order models (ROMs) are often coupled with concurrent multiscale simulations to mitigate the computational cost of nonlinear computational homogenization methods. Construction (or training) of ROMs typically requires evaluation of a series of linear or nonlinear equilibrium problems, which itself could be a computationally very expensive process. In the eigenstrain-based reduced order homogenization method (EHM), a series of linear elastic microscale equilibrium problems are solved to compute the localization and interaction tensors that are in turn used in the evaluation of the reduced order multiscale system. These microscale equilibrium problems are typically solved using either the finite element method or semi-analytical methods. In the present study, a reduced order variational spectral method is developed for efficient computation of the localization and interaction tensors. The proposed method leads to a small stiffness matrix that scales with the order of the reduced basis rather than the number of degrees of freedom in the finite element mesh. The reduced order variational spectral method maintains high accuracy in the computed response fields. A speedup higher than an order of magnitude can be achieved compared to the finite element method in polycrystalline microstructures. The accuracy and scalability of the method for large polycrystals and increasing phase property contrast are investigated.  相似文献   
14.
    
Subjective wear trials were conducted to evaluate effects of disposable antibacterial sweat pads on foot thermal comfort. Sweat pads were produced with polypropylene and polylactic acid nonwoven topsheet layers which were treated with different herbal antibacterial materials. Trials were carried out with 10 male subjects under 10 °C and 50% relative humidity simulating sweating during a moderate activity in cold environments. Besides microclimate temperature and relative humidity measurements, subjective thermal (coolness, dampness, and comfort) and other sensations (stickiness, slippiness, etc.) were obtained by five point rating scales. Bending rigidity, friction coefficients, and moisture management properties of the topsheet fabrics and pads were tested. Results show that foot sweat pads enabled drier microclimate, warmer sensations, and higher comfort evaluations. Antibacterial treatments did not affect bending rigidity values of the nonwoven topsheet fabrics, but some applications decreased spreading speed, increased roughness of the pad surfaces, and wetting time values which are not preferable.  相似文献   
15.
    
Turbidity and chemical oxygen demand (COD) removal efficiencies were analyzed depending on electrode layouts by performing electrocoagulation experiments using horizontal and vertical electrochemical cells. Multiple aluminum plate electrodes were placed into different sections of the electrochemical cells. Removal efficiencies at the horizontal electrochemical cell were always higher than the one’s obtained from the vertical electrochemical cell. But the use of vertical electrochemical cell consumed less energy during the electrocoagulation tests. The highest COD removal efficiencies were 97% and 88% in the horizontal and vertical electrochemical cells, respectively. However, the energy consumption for COD removal in the horizontal electrochemical cell was 47% higher than the energy consumed in the vertical electrochemical cell.  相似文献   
16.
    
The spontaneous combustion liability of coal can be determined by using different experimental techniques. These techniques are well-known in their application, but no certain test method has become a standard to prove the reliability of all of them. A general characterisation which included proximate and ultimate analyses, petrographic properties and spontaneous combustion tests(thermogravimetric analysis(TGA) and the Wits-Ehac tests) were conducted on fourteen coal and four coal-shale samples.The spontaneous combustion liability of these samples collected between coal seams(above and below)were predicted using the TGA and the Wits-Ehac tests. Six different heating rates(3, 6, 9, 15, 20 and 25 °C/min) were selected based on the deviation coefficient to obtain different derivative slopes and a liability index termed the TG_(spc) index. This study found that coal and coal-shale undergo spontaneous combustion between coal seams when exposed to oxygen in the air. Their intrinsic properties and proneness towards spontaneous combustion differ considerably from one seam to the other. The Wits-Ehac test results agreed with the TG_(spc) results to a certain extent and revealed the incidents of spontaneous combustion in the coal mines.  相似文献   
17.
    
The characterization of the physical and chemical properties of coal on a standard provides an understanding of its characteristics towards spontaneous combustion. The trend of linear relationships between coal recording standards (% air-dried (ad), % dry (db) and % dry ash free (daf) basis) of 30 selected coal samples from the Witbank coalfields and spontaneous combustion liability indices were evaluated. The spontaneous combustion liability indices of these samples were evaluated by crossing point temperature (XPT), Stage II Slope, FCC (Feng, Chakravorty, Cochrane) and the Wits-Ehac tests, while the coal properties were determined from the proximate and ultimate analyses. The results obtained from these coal properties were related to different liability indices to develop trends of linear relationships using regression analysis. The ad basis indicated higher correlation coefficients than the db and daf basis for the XPT and FCC index, while the daf showed higher correlation coefficients than the ad and db basis for the Wits-Ehac index. It was found that the trend of linear relationships of these coal properties differs from one liability index to the next. The XPTs showed a better trend followed by the Stage II Slope on the coal properties among the spontaneous combustion liability indices evaluated.  相似文献   
18.
    
In this study, the effect of plasma treatment and nanofinishing on leather properties was investigated. O2 and N2 gases were used for activating the leather surface, and thin layers were deposited by hexamethyldisiloxane and tetraethyloxysilane. Nanofinishing process was performed using TiO2–SiO2 nanocomposite solution. The surface properties of the treated leathers were characterized by scanning electron microscopy and atomic force microscopy. The results showed that the hydrophobicity of leather was clearly improved after plasma end treatment with hexamethyldisiloxane, while treatment with tetraethyloxysilane increased its hydrophilic property. Moreover, the fastness properties and water vapor permeability of leathers were improved.  相似文献   
19.
Fecal indicators such as Escherichia coli and enterococci are used as regulatory tools to monitor water with 24 h cultivation techniques for possible input of sewage or feces and presence of potential enteric pathogens yet their source (human or animal) cannot be determined with routine methods. This critical uncertainty has furthered water pollution science toward new molecular approaches. Members of Bacteroides genus, such as Bacteroides thetaiotaomicron are found to have features that allow their use as alternative fecal indicators and for Microbial Source Tracking (MST). The overall aim of this study was to evaluate the concentration and fate of B. thetaiotaomicron, throughout a wastewater treatment facility and septage treatment facility. A large number of samples were collected and tested for E. coli and enterococci by both cultivation and qPCR assays. B. thetaiotaomicron qPCR equivalent cells (mean: 1.8 × 107/100 mL) were present in significantly higher concentrations than E. coli or enterococci in raw sewage and at the same levels in raw septage. The removal of B. thetaiotaomicron target qPCR signals was similar to E. coli and enterococci DNA during the treatment of these wastes and ranged from 3 to 5 log10 for wastewater and was 7 log10 for the septage. A significant correlation was found between B. thetaiotaomicron marker and each of the conventional indicators throughout the waste treatment process for both raw sewage and septage. A greater variability was found with enterococci when compared to E. coli, and CFU and equivalent cells could be contrasted by various treatment processes to examine removal and inactivation via septage and wastewater treatment. These results are compared and contrasted with other qPCR studies and other targets in wastewater samples providing a view of DNA targets in such environments.  相似文献   
20.
This paper examines the discharge and velocity distributions in natural open channel flows using the entropy theory. Flow measurements were carried out at four different cross‐sections in central Turkey. The mean and maximum velocities at these stations exhibited a linear distribution and the entropy parameter was calculated to be M=1.31. Using this value, discharges for all flow conditions were calculated as a function of the measured maximum velocities (umax). It was observed that the umax/H and zmax/H ratios remained relatively constant when 0.2≤y/T≤0.8, especially for the wider channels. Using these constant values for each station, umax and zmax could be determined solely as a function of the water depth H. Although the calculated velocities were higher than those measured at some verticals, the entropy‐based approach presents an attractive alternative to the traditional flow‐measurement techniques for the determination of flow properties because of its simplicity and quick application.  相似文献   
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