A vehicle detection scheme based on two-dimensional HOG features in the DFT and DCT domains

Multidimensional Systems and Signal Processing - Histogram of oriented gradients (HOG) are often used as features for object detection in images, since they are robust to changes in illumination...     

Improving combustion characteristics of diesel and biodiesel droplets by graphite oxide addition for diesel engine applications

Graphite oxide (GO) is an important member of the graphene family of carbon nanomaterials with remarkable physical, chemical, and thermal properties. We conducted an experimental investigation on the combustion characteristics of diesel and biodiesel droplets dosed with 0.1% GO. The fuels were tested by a single droplet combustion experiment in which the temporal variation in the burning behavior of a suspended droplet was captured using a high‐speed camera. Numerical analysis of the combustion data suggests that the addition of GO in both fuels resulted in shortened ignition delay (by up to 38.2%), increased burn‐rate constant (by up to 29.4%), lowered peak temperature (by up to 7.8%), and shortened burning period (by up to 11.6%). To illustrate, the burn‐rate constant increased from 0.68 to 0.88 mm²/second, and the burning period reduced from 2.7 to 2.2 seconds when GO was dosed in diesel. By contrast, the ignition delay and peak temperature both decreased from 1.6 to 1.4 seconds and 659 to 611 K, respectively, when GO was added in biodiesel. Our results suggest that the fuel additive–induced benefits could effectively reduce emissions and improve fuel consumption for diesel engine applications.     

An improved surveillance video synopsis framework: a HSATLBO optimization approach

Video surveillance cameras capture huge amount of data 24 hours a day. However, most of these videos contain redundant data which make the process difficult for browsing and analysis. A significant amount of research findings have been made in summarization of recorded video, but such schemes do not have much impact on video surveillance applications. On the contrary, video synopsis is a smart technology that preserves all the activities of every single object and projects them concurrently in a condensed time. The energy minimization module in video synopsis framework plays a vital role, which in turn minimizes the activity loss, number of collision and temporal consistency cost. In most of the reported schemes, Simulated Annealing (SA) algorithm is employed to solve the energy minimization problem. However, it suffers from slow convergence rate resulting in a high computational load to the system. In order to mitigate this issue, this article presents an improved energy minimization scheme using hybridization of SA and Teaching Learning based Optimization (TLBO) algorithms. The suggested framework for static surveillance video synopsis generation consists of four computational modules, namely, Object detection and segmentation, Tube formation, Optimization, and finally Stitching and the central focus is on the optimization module. Thus, the present work deals with an improved hybrid energy minimization problem to achieve global optimal solution with reduced computational time. The motivation behind hybridization (HSATLBO) is that TLBO algorithm has the ability to search rigorously, ensuring to reach the optimum solution with less computation. On the contrary, SA reaches the global optimum solution, but it may get disarrayed and miss some critical search points. Exhaustive experiments are carried out and results compared with that of benchmark schemes in terms of minimizing the activity, collision and temporal consistency costs. All the experiments are conducted on five widely used videos taken from standard surveillance video data set (PETS 2001, MIT Surveillance Dataset, ChangeDetection.Net, PETS 2006 and UMN Dataset) as well as one real generated surveillance video from the IIIT Bhubaneswar Surveillance Dataset. To make a fair comparison, additionally, performance of the proposed hybrid scheme to solve video synopsis optimization problem is also compared with that of the other benchmark functions. Experimental evaluation and analysis confirm that the proposed scheme outperforms other state-of-the-art approaches. Finally, the suggested scheme can be easily and reliably deployed in the off-line video synopsis generation.

     

Robust coding in a global subspace model and its collaboration with a local model for visual tracking

Multimedia Tools and Applications - The sparse representation-based trackers has attracted much attention in the research community due to its superior performance in spite of its computational...     

Harmonic interaction between 1500 kVA supply transformer and VFDload at an industrial plant

The application of variable-frequency drives (VFDs) in industrial and commercial facilities has seen a tremendous increase. However, when multiple VFDs are fed from one dedicated power transformer, care should be taken not to drive the transformer into saturation. At one industrial location, nine VFDs rated at 200 HP each, and fed from a single 1500 kVA air-cooled transformer, showed saturation phenomenon, which had the potential of causing serious damage to the transformer. This paper discusses the input AC current waveform asymmetry caused by the interaction of the transformer and the nine 200 HP VFD load fed from it. The term waveform asymmetry is used when the positive half of the input AC current cycle is not equal to the negative half of the input AC current cycle. This results in the existence of DC components along with even harmonics in the input at current waveform. The various tests and the eventual solution to the waveform asymmetry caused by the VFDs is presented. The value of the inductance in the DC smoothing inductor (DC-link choke), which is included as part of the VFD, was found to contribute significantly to the waveform asymmetry. Experimental results showing the performance of a reconfigured DC-link inductor to reduce its interaction with the power transformer are presented     

Structure–property relationship of starch‐filled chain‐extended polyurethanes

Chain‐extended polyurethane (PU) elastomers were prepared using castor oil with 4,4′‐methylene bis (phenyl isocyanate) (MDI) as a crosslinker and 4,4′‐diamino diphenyl sulphone (DDS) as an aromatic diamine chain extender. A series of starch‐filled (from 5 to 25% wt/wt) diamines chain‐extended PUs have been prepared. The starch‐filled PU composites were characterized for physico‐mechanical properties viz, density, surface hardness, tensile strength, and percentage elongation at break. Thermal stability of PU/starch have been carried out by using thermogravimetric analyzer (TGA). Thermal degradation process of PU/starch were found to proceed in three steps. TGA thermograms of PU/starch shows that all systems were stable upto 235°C, and maximum weight loss occur at temperature 558°C. The microcrystalline parameters such as crystal size (〈N〉) and lattice strain (g in %) of PU/starch have been established using wide‐angle X‐ray scattering (WAXS) method. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2945–2954, 2003     

Etched multimode microfiber knot-type loop interferometer refractive index sensor

We propose a novel refractive index sensor based on multimode microfiber knot-type loop (NL) interferometer. The middle portion (~5 cm) of a 15 cm long multimode fiber is etched in 48% hydrofluoric acid to reduce its diameter to ~12 μm. A NL of diameter <1 mm is made from the etched fiber. The ends of etched fiber are spliced with single-mode fibers for launching and detecting light from the NL interferometer. The NL introduces path differences to produce interferometric spectra with free spectral range ~16 nm. The spectrum shifts as the surrounding refractive index of the loop is changed by adding chemicals. We observe the highest sensitivity of the NL interferometer ~172 nm/RIU (refractive index unit) at a refractive index value 1.370 as obtained experimentally using commonly available chemicals. The design could be used as simple, low cost, and highly sensitive biological and chemical sensor.     

Compressibility of baddeleyite-type TiO2 from static compression to 40 GPa

We present room-temperature pressure–volume data for TiO₂ baddeleyite obtained from powder X-ray diffraction with a diamond anvil cell from room pressure to 40 GPa. A zero-pressure unit cell volume V_o=110.48(5) ų was obtained from a sample recovered cryogenically from 37 GPa. This datum together with in situ high-pressure volume data upto 40 GPa was fitted to a Birch–Murnaghan equation of state to yield a bulk modulus value of 303(5) GPa and its pressure derivative 3.9(2).     

An Adaptive Multiuser Detection Algorithm for CDMA Systems Using Antenna Diversity

Based on the minimum mean squared error (MMSE) between the data stream and the linear combiner output, a new multiuser detection (MUD) algorithm that combines space–time (ST) processing and antenna array on direct-sequence CDMA signals is proposed. The proposed ST-MUD algorithm is proved to be equivalent to two existing MMSE-based ST-MUD algorithms, and the theoretical BER performances for all the three algorithms are the same. The most attractive feature of the new ST-MUD algorithm is based on the fact that the new method does not require explicit estimation of channel and signaling information. This avoids any channel estimation error, and the method is thus more robust and more accurate than the other two ST-MUD algorithms in practical implementation. Adaptation of the proposed ST-MUD algorithm is implemented by using training sequences. Performance of this new multiuser detector is compared with that of two existing MMSE multiuser detectors and the conventional single-user space–time rake receiver through simulations. The proposed ST-MUD algorithm provides a performance better than existing algorithms and is especially suitable for practical CDMA systems.