Realization of 2-D Variable IIR Digital Filter Structures with a Small Amount of Calculations for Coefficient Update

This paper proposes 2-D variable IIR digital filter structures with a small amount of calculations for coefficient update. The proposed realization method uses the 2-D parallel allpass structure derived from the separable denominator 2-D filter as the prototype structure for 2-D variable digital filters. In order to reduce the amount of calculations, all the redundant first-order complex allpass sections are combined by modularization of the variable structure. Furthermore, we can realize a very compact variable structure with a minimal number of first-order complex allpass sections by combining complex allpass sections with their complex conjugate allpass sections. Comparison of the calculation loads of the variable structures is presented to demonstrate that the amount of calculations for coefficient update of the proposed variable structure is far less than that of the original and the modular variable structure.     

Preparation of modified polyesters containing triphosphorous and their applications to PU flame-retardant coatings

Three phosphorous functional groups were introduced in one structural unit of polymer backbone to enhance the flame retardancy of PU coatings. In the first step, we synthesized tetramethylene bis(orthophosphate) (TBOP) that contained two phosphorus functional groups in one structural unit. In the next step, we synthesized modified polyesters (ATBTP-10,-20,-30) that contained triphosphorous groups by condensing polymerization of TBOP, 1,4-butanediol, trimethylolpropane, adipic acid, and phenylphosphonic acid (PPA). The amount of PPA in the ATBTPs was 10, 20, and 30 wt%. Then, flame-retardant PU coatings (AHFC−10,−20,−30) were prepared by curing ATBTPs with hexamethylene diisocyanate-biuret (curing agent) at room temperature. From the TGA analysis of diphosphorus-modified polyester (ATBT) and ATBTPs, the residues of ATBT, ATBTP-10, ATBTP-20, and ATBTP-30 were 24.6, 27.5, 29.2, and 31.9%, respectively. From this result, it was found that the residue increased in relation to the amount of PPA. Physical properties of the films of flame-retardant coatings were deteriorated with the addition of PPA (flame retarding component), however, all the films of flame-retardant coatings, except AHFC-30, met the required physical properties standard for coatings. Char lengths of the AHFCs measured by the 45° Meckel burner method were 2.9∼4.8 cm, and LOI values were 28∼31%, which indicates that the prepared AHFCs showed good flame retardancy.     

A Fast H.264 Intra Frame Encoder with Serialized Execution of 4 × 4 and 16 × 16 Predictions and Early Termination

This paper presents a fast H.264 intra frame encoder that processes a single macroblock of 1920 × 1080 size video in 334 cycles on average which is 20% faster than the previous best design. The speed-up is mainly achieved by early termination of either 4 × 4 intra prediction or 16 × 16 intra prediction. The executions of intra 4 × 4 and 16 × 16 predictions are serialized and the second prediction is terminated early by using the cost of the first prediction as the stop criterion. A simple and efficient algorithm by making use of spatial locality is proposed to select the mode that is processed first. To avoid the bubble cycles caused by this serialized execution of 4 × 4 and 16 × 16 predictions, the modified processing order presented in (Jung et al. 2008) is employed for intra 4 × 4 prediction in order to schedule dependent 4 × 4 blocks apart from each other. To further reduce the execution time of 4 × 4 prediction, neighboring pixels with the same value are grouped, and only one prediction mode in the group is evaluated. Experimental results show that the PSNR drop is 0.0619 dB and the bitrate increase is 0.842% when compared with the JM reference software. The additional hardware cost to support the proposed methods is less than eight thousand gates which are very small when compared with the hardware size of a whole intra frame encoder.     

Automatic Generation of Modular Time-Space Mappings and Data Alignments

Time-space transformations and data alignments that can lead to efficient execution of parallel programs have been extensively studied. Recently, modular time-space transformations have been proposed to generate a class of algorithm mappings that cannot be described by linear time-space transformations. This paper proposes a new class of data alignments, called expanded modular data alignments (EMDAs), for programs that result from modular time-space transformations. An EMDA subsumes multiple modular data alignments, which are described by affine functions modulo a constant vector. Conditions of a modular time-space mapping and an EMDA for perfect alignment are described. However, these conditions together with other conditions for validity and optimality of a modular mapping introduce nonlinear constraints in the problem of generating modular mappings. A method of O(n ²) complexity is provided to choose some entries of a transformation matrix so that nonlinear constraints are transformed into linear ones, where n is the dimension of the computation domain (e.g., the number of nested loops). Although the solution space of the problem is reduced by assigning fixed values to some entries, the proposed heuristic attempts to minimize the number of the fixed entries and consequently to exclude as few solutions as possible.     

Effect of Load Distribution on the Voltage Drop and the Luminance Variation in an AC-PDP

In an alternating-current plasma display panel (AC-PDP), the displayed luminance of a cell is often different from the target luminance because the luminance is affected by the voltage applied to the cell, which is determined by the distribution of on-cells. In this letter, a circuit model of an AC-PDP is presented, and the effect of load distribution on the applied voltage is analyzed with the circuit model. The analytical results are validated by the experimental measurements with an AC-PDP set.     

A fast seed detection using local geometrical feature for automatic tracking of coronary arteries in CTA

We propose a fast seed detection for automatic tracking of coronary arteries in coronary computed tomographic angiography (CCTA). To detect vessel regions, Hessian-based filtering is combined with a new local geometric feature that is based on the similarity of the consecutive cross-sections perpendicular to the vessel direction. It is in turn founded on the prior knowledge that a vessel segment is shaped like a cylinder in axial slices. To improve computational efficiency, an axial slice, which contains part of three main coronary arteries, is selected and regions of interest (ROIs) are extracted in the slice. Only for the voxels belonging to the ROIs, the proposed geometric feature is calculated. With the seed points, which are the centroids of the detected vessel regions, and their vessel directions, vessel tracking method can be used for artery extraction. Here a particle filtering-based tracking algorithm is tested. Using 19 clinical CCTA datasets, it is demonstrated that the proposed method detects seed points and can be used for full automatic coronary artery extraction. ROC (receiver operating characteristic) curve analysis shows the advantages of the proposed method.     

Analysis and modeling of highway truck traffic volume variations during severe winter weather conditions in Canada

Railway Engineering Science - This paper investigates the impact of cold and snow on daily and hourly truck traffic volume on a primary highway in Alberta, Canada. This research is based on a...     

Relative efficiency appraisal of discrete choice modeling algorithms using small-scale maximum likelihood estimator through empirically tailored computing environment

Discrete choice models are widely used in multiple sectors such as transportation, health, energy, and marketing, etc., where the model estimation is usually carried out by using commercial software. Nonetheless, tailored computer codes offer modellers greater flexibility and control of unique modelling situation. Aligned with empirically tailored computing environment, this research discusses the relative performance of six different algorithms of a discrete choice model using three key performance measures: convergence time, number of iterations, and iteration time. The computer codes are developed by using Visual Basic Application (VBA). Maximum likelihood function (MLF) is formulated and the mathematical relationships of gradient and Hessian matrix are analytically derived to carry out the estimation process. The estimated parameter values clearly suggest that convergence criterion and initial guessing of parameters are the two critical factors in determining the overall estimation performance of a custom-built discrete choice model.

     

MVDet: multi-view multi-class object detection without ground plane assumption

Pattern Analysis and Applications - Although many state-of-the-art methods of object detection in a single image have achieved great success in the last few years, they still suffer from the false...