Fast intra prediction mode decision for H.264/AVC video coding

Abstract

Intra coding is used for reducing the spatial redundancy in video coding. H.264 supports several macroblocks of predictions for intra coding such as luma block four 16×16 modes, nine 4×4 modes and chroma block four modes, which significantly improve intra coding efficiency, but increase the encoding complexity. In order to select the best mode, we need to calculate the cost of the various modes. In this paper, a fast intra prediction mode decision for H.264/AVC video coding is proposed. Based on Laplacian, this intra prediction mode decision detects edges and selects the best mode for the block. This mode decision can shorten the time to reduce the encoding time. The experimental results show that the proposed algorithm achieves an encoding time saving of 70% on average.     

Developing a factory-wide intelligent predictive maintenance system based on Industry 4.0

Abstract

The main purpose of predictive maintenance (PdM) is to reduce unscheduled downtime and consequently improve productivity and reduce production cost. PdM has been featured as a key theme of Industry 4.0. However, the traditional PdM system was only designed for a single tool; as such, the resources allocation will become extremely complicated when hundreds of tools are working together in a factory. A manageable hierarchy and various health indexes are required for factory-wide equipment maintenance. To solve the problem mentioned above, this paper proposes a factory-wide intelligent predictive maintenance system by applying the so-called cyber-physical agent and advanced manufacturing cloud of Things to fulfill the requirements of Industry 4.0, the baseline predictive maintenance scheme to accomplish the PdM functions, and the newly proposed health index hierarchy to supervise factory-wide equipment maintenance.     

Efficient rate control scheme using modified inter-layer dependency for spatial scalability

Scalable video coding extension has been added to H.264AVC to support compression and encoding of multiple resolution video sequences, having different frame rates and fidelities in a single bit stream. The motion vectors and the residual data of the enhancement layers are derived from up-sampling the co-located macroblock (MB) of the base layer. The peak signal to noise ratio (PSNR) across the enhancement layers is degraded as up-sampling introduces distortion of high-frequency components. In this paper, a spatial-resolution-ratio-based MB mode decision scheme is proposed for spatially enhanced layers. The scheme uses the motion estimated at the base layer, to encode the respective MBs in the enhancement layers. The spatial–temporal search schemes at the enhancement layers are used to derive motion vectors and residues that are encoded using a quantization parameter obtained using independent rate control (IRC) scheme. The IRC from the prior art is modified to achieve better rate control per layer by recursive updates for mean absolute difference values of each basic unit. Proposed modified inter-layer dependency shows improvement in the PSNR for enhancement layers while the updated IRC enforces better IRC for all the layers.     

Seamless coupling of molecular dynamics and material point method via smoothed molecular dynamics

A concurrent multiscale method coupling molecular dynamics (MD) and continuum‐based material point method (MPM) is proposed. Seamless coupling is realized by utilizing smoothed molecular dynamics (SMD) method. One set of background mesh is used in SMD method. Atomic equations of motion are assembled onto mesh nodes, and atomic variables are updated with nodal increments. SMD allows much larger time step size than MD critical time step size but keeps nice global accuracy. SMD is similar to MD except for the mapping process between background mesh nodes and atoms. SMD and MPM share the feature using the background mesh to solve momentum equations and to update variables. So bridging MD and MPM via SMD is straightforward and concise. A recently proposed transition scheme based on frequency decomposition is adopted to suppress phonon reflection at MD‐SMD interface. The nodal equations in SMD–MPM interface region have contributions from both atoms and material points, which ensure the consistency between SMD region and MPM region. A multiple‐time‐step scheme is adopted for high efficiency. Numerical examples including wave propagation, bending, and crack propagation validate the proposed method, and the results show nice accuracy. The computational cost is greatly saved compared with pure MD computation. Copyright © 2017 John Wiley & Sons, Ltd.     

Design of a low‐power way‐predicting cache using valid‐bit pre‐decision strategy

Abstract

Way‐predicting cache is one of the set‐associative caches that can effectively reduce power consumption, which only speculatively selects an MRU (most recently used) way before starting a normal cache access. Focusing on the way‐predicting cache using sub‐block placement, we propose a new cache scheme that uses valid bits from data memory to decide the disabled tag‐subarrays and data‐subarrays. By using valid‐bit pre‐decision, the proposed scheme has a significant improvement in average energy saving over the conventional way‐predicting cache, especially for large associativity and small sub‐block size. Moreover, because those original second accessed ways are first accessed during the first cycle when the valid bit of the MRU way does not exist, the proposed cache also can reduce the average access time.     

Flux‐difference splitting scheme with modified multidimensional dissipation on unstructured meshes

Abstract

A flux‐difference splitting scheme with a modified multidimensional dissipation for high‐speed compressible flow analysis on unstructured meshes is presented. The scheme eliminates unphysical flow behaviors such as a spurious bump of the carbuncle phenomenon that occurs on the bow shock from flow over a blunt body, and the expansion shock generated from flow over a forward facing step. The switching function suggested by Quirk is implemented as a choice to detect the vicinity of strong shock. The proposed scheme is further extended to obtain higher‐order spatial and temporal solution accuracy. The scheme is, in addition, combined with an adaptive meshing technique that generates unstructured triangular meshes to resemble the flow phenomena for reducing computational effort. The entire procedure is evaluated by solving several benchmarks as well as steady‐state and transient high‐speed compressible flow problems.     

Molecular dynamics‐smoothed molecular dynamics (MD‐SMD) adaptive coupling method with seamless transition

Smoothed molecular dynamics (SMD) method is a recently proposed efficient molecular simulation method by introducing one set of background mesh and mapping process into molecular dynamics (MD) flow chart. SMD can sharply enlarge MD time step size while maintaining global accuracy. MD‐SMD coupling method was proposed to improve the capability to describe local atom disorders. The coupling method is greatly improved in this paper in two essential aspects. Firstly, a transition scheme is proposed to avoid artificial wave reflection at the interface of MD and SMD regions. The new transition scheme has simple formulation and high efficiency, and the wave reflection can be well suppressed. Secondly, an adaptive scheme is proposed to automatically identify the regions requiring MD simulation. Two adaptive criteria, the centro‐symmetry parameter criterion and the displacement criterion, are also proposed. It is found that both the two criteria can achieve good accuracy but the efficiency of the displacement criterion is much better. The coupling method does not demand reduction in mesh size near the interface, and a multiple time stepping scheme is adopted to ensure high efficiency. Numerical results including wave propagation, nano‐indentation, and crack propagation validate the method and show nice accuracy. Copyright © 2016 John Wiley & Sons, Ltd.     

Temporal evaluation of fringe patterns with spatial carrier with an improved asynchronous phase demodulation algorithm

Abstract

A method for temporal evaluation of fringe patterns with a spatial carrier is presented. The proposed technique consists in the recording of the temporal irradiance fluctuations obtained when a linear variation of the set-up sensitivity is introduced. In this way, the use of a spatial carrier introduces a linear temporal carrier frequency. This allows the use of fast and low time consuming temporal asynchronous demodulation algorithms, similar to those employed in spatial phase shifting techniques. An existing five-step algorithm has been corrected for asynchronous demodulation. It is shown that it is possible to fix the sensitivity variation in such a way that the algorithm presents optimum behaviour against noise and nonlinearities presented by the temporal irradiance signal. Finally, the technique has been applied to measure the shape of an object, using a fringe projection set-up.     

The effect of extended‐hours hemodialysis on outcomes: A systematic review and meta‐analysis

Extended‐hours hemodialysis is associated with improvements in quality of life (QoL) and mortality, but it may accelerate the loss of residual kidney function (RKF) and increase vascular access complications. Multiple established databases were systematically searched; randomized and non‐randomized studies were pooled separately. QoL outcomes were assessed using standardized mean difference (SMD), vascular access adverse events and mortality were assessed with relative risk ratios (RR). Four hundred seventy‐six patients from six trials were eligible. Data from randomized controlled trials (RCTs) could only be synthesized for vascular access adverse events and mortality, which demonstrated no significant change in vascular access adverse events (RR 1.25, 95% CI 0.88 to 1.77) or mortality (RR 2.29, 95% CI 0.60 to 8.71). Pooled data from non‐randomized trials demonstrated no significant difference in QoL (SF‐36 Physical Component Summary SMD 0.61, 95% CI ?0.10 to 1.31, SF‐36 Mental Component Summary SMD ?0.04, 95% CI ?0.61 to 0.54). RKF was assessed in one report which demonstrated a potential reduction over 12 months with extended‐hours hemodialysis. The majority of trials had high risk of bias. Extended‐hours hemodialysis was not associated with improved QoL or mortality, or increased vascular access events. Adequately powered RCTs are needed to fully assess extended‐hours hemodialysis.     

Colour image coding scheme using absolute moment block truncation coding and block prediction technique

Abstract

A predictive colour image compression scheme based on absolute moment block truncation coding is proposed. In this scheme, the high correlations among neighbouring image blocks are exploited by using the similar block prediction technique. In addition, the bit plane omission technique and the coding of quantisation levels are used to cut down the storage cost of smooth blocks and complex blocks respectively. According to the experimental results, the proposed scheme provides better performance than the comparative schemes based on block truncation coding. It provides better image qualities of compressed images at low bit rates. Meanwhile, it consumes very little computational cost. In other words, the proposed scheme is quite suitable for real time multimedia applications.     

Measurement of the spatial coherence of superluminescent diodes

Abstract

In recent years, superluminescent diodes (SLDs) have gained increasing importance as light sources for partial coherence interferometry and optical coherence tomography. The requirements of SLDs are high spatial coherence, low temporal coherence, and, for some applications, high power. Since there might be a trade-off between these properties we built an instrument for measuring the spatial coherence of SLDs. This instrument consists of a hybrid bulk optic-fibre optic Mach-Zehnder interferometer. The special advantages of the instrument are the ability to measure the spatial coherence between arbitrary points within the light beam and to observe directly the measurement points within the beam which facilitates the alignment. We used this instrument to evaluate the spatial coherence of several commercially available SLDs. As expected, a single mode fibre pigtailed SLD shows the best spatial coherence. If free-space emitting SLDs are considered, those with a more complicated chip structure have a somewhat poorer spatial coherence, however, their temporal coherence is considerably better than that of a SLD which is only antireflection coated.     

New model diagnostics for spatio-temporal systems in epidemiology and ecology

A cardinal challenge in epidemiological and ecological modelling is to develop effective and easily deployed tools for model assessment. The availability of such methods would greatly improve understanding, prediction and management of disease and ecosystems. Conventional Bayesian model assessment tools such as Bayes factors and the deviance information criterion (DIC) are natural candidates but suffer from important limitations because of their sensitivity and complexity. Posterior predictive checks, which use summary statistics of the observed process simulated from competing models, can provide a measure of model fit but appropriate statistics can be difficult to identify. Here, we develop a novel approach for diagnosing mis-specifications of a general spatio-temporal transmission model by embedding classical ideas within a Bayesian analysis. Specifically, by proposing suitably designed non-centred parametrization schemes, we construct latent residuals whose sampling properties are known given the model specification and which can be used to measure overall fit and to elicit evidence of the nature of mis-specifications of spatial and temporal processes included in the model. This model assessment approach can readily be implemented as an addendum to standard estimation algorithms for sampling from the posterior distributions, for example Markov chain Monte Carlo. The proposed methodology is first tested using simulated data and subsequently applied to data describing the spread of Heracleum mantegazzianum (giant hogweed) across Great Britain over a 30-year period. The proposed methods are compared with alternative techniques including posterior predictive checking and the DIC. Results show that the proposed diagnostic tools are effective in assessing competing stochastic spatio-temporal transmission models and may offer improvements in power to detect model mis-specifications. Moreover, the latent-residual framework introduced here extends readily to a broad range of ecological and epidemiological models.     

Bayesian Nonparametric Joint Mixture Model for Clustering Spatially Correlated Time Series

Abstract

We develop a Bayesian nonparametric joint mixture model for clustering spatially correlated time series based on both spatial and temporal similarities. In the temporal perspective, the pattern of a time series is flexibly modeled as a mixture of Gaussian processes, with a Dirichlet process (DP) prior over mixture components. In the spatial perspective, the spatial location is incorporated as a feature for clustering, like a time series being incorporated as a feature. Namely, we model the spatial distribution of each cluster as a DP Gaussian mixture density. For the proposed model, the number of clusters does not need to be specified in advance, but rather is automatically determined during the clustering procedure. Moreover, the spatial distribution of each cluster can be flexibly modeled with multiple modes, without determining the number of modes or specifying spatial neighborhood structures in advance. Variational inference is employed for the efficient posterior computation of the proposed model. We validate the proposed model using simulated and real-data examples. Supplementary materials for the article are available online.     

Temporal phase evaluation by fourier analysis of fringe patterns with spatial carrier

Abstract

A new method is presented for the temporal evaluation of fringe patterns with spatial carrier. The proposed technique involves recording the irradiance fluctuations obtained when a linear variation of the set-up sensitivity is introduced. In this condition, the use of a spatial carrier introduces a linear temporal carrier frequency. In this way, Fourier analysis can be performed to obtain the phase and, finally, the quantity to be measured. The optimum conditions for the sensitivity variation have been studied in order to minimize the errors associated with the Fourier analysis. The technique has been applied to measure the distribution of ray deflections on the surface of two ophthalmic lenses using a deflectometric set-up.     

混凝土大坝加高施工关键技术研究

以国内外混凝土坝加高工程施工实践为基础,系统总结混凝土重力坝后帮整体式加高施工中的四项关键技术,即混凝土原材料及配合比、新老混凝土结合、原有结构体的控制拆除与转移、施工期资源的时间与空间调配。针对其中的每一项关键技术,分析了其施工技术难点与特点、施工技术要求,并总结了其技术措施和解决策略,以期为同类型工程建设提供参考与借鉴。     

Rotating Gratings Reveal the Temporal Transfer Function of the Observing System

Abstract

It is shown that a rotating sinusoidal grating is a useful sweep signal for the analysis of the temporal behaviour of linear imaging systems. For a suitably chosen angular velocity and spatial frequency, the spatial a.c. component of the grating appears modulated in one dimension at the output of the system. The profile of this modulation is the temporal transfer function (TTF) of the system. A quantitative analysis of this effect is presented, and results from experiments with a photographic camera are shown. It is proposed to use this method in the field of vision research since it is presently the only way to demonstrate the complex-valued TTF of the visual system for suprathreshold grating stimuli. The main consequence of the first psycho-physical investigations was the discovery of a phase reversal at the origin of the TTF of the human visual system for gratings of low spatial frequency.     

Game Theory Based Decision Coordination Strategy of Agricultural Logistics Service Information System

Under the background of “Internet plus” rapid development, the agricultural logistics industry should apply information technology to every link of the agricultural product logistics industry chain. By making full use of the decision making module of the agricultural logistics information system, we can realize the full sharing of information and data resources, which makes the decision-making scheme of the agricultural logistics information system more optimized. In real economic society, the uncertainty and mismatch between the customer’s logistics service demand and the logistics service capability that the logistics service function provider can provide, that is, when the two information are asymmetric, how to use the third-party contract to coordinate the income and profit distribution of the two, to make the information system decision making more reasonable? This paper mainly studies the coordination scheme of agricultural logistics information system decision making under uncertain output and demand information by introducing the spot market. A joint coordination strategy based on revenue sharing and penalty feedback contracts proposes decentralized decision making based on game theory. Experiments show that the flexible ordering strategy proposed in this paper can reduce the logistics service supply chain’s uncertainty and significantly improve the logistics service supply chain’s overall income level through coordination contracts.     

Fuzzy-based coverage and capacity scheme in LTE heterogeneous networks

Abstract

Coverage and capacity optimization (CCO) is a crucial procedure in Long-Term Evolution (LTE) Self-Organizing Network (SON). In recent studies, fuzzy theory has been widely applied for CCO in centralized SON but not in distributed SON. Distributed SON can be applied in user-deployed small cells such as femtocells. In the present paper, a distributed, autonomous, and low-complexity fuzzy-based coverage and capacity scheme is proposed for LTE heterogeneous networks (HetNet). To accomplish this goal, the proposed scheme manages radio resources to minimize inter-cell interference. A tradeoff exists between cell coverage and capacity due to inter-cell interference. By leveraging three fuzzy memberships, the scheduling decision is adaptively made by a low-complexity intersection function. Different from conventional fuzzy approaches, the proposed approach does not depend on pre-defined fuzzy rules and pre-defined fuzzy membership models. System performance is evaluated in terms of throughput and energy efficiency. The simulation results show that the proposed approach improves system performance by up to about 39% compared with a joint optimization algorithm.     

Intra mode decision and frame layer Lagrange multiplier adjustment scheme for H.264 based on structural similarity

H.264 takes rate distortion optimisation (RDO) technique to perform intra and inter mode decision and achieves higher coding efficiency, but the objective distortion metric such as mean square error (MSE) is employed in traditional RDO framework, which cannot acquire optimal subjective quality. In this paper, structural similarity (SSIM)-based subjective distortion is applied to RDO-based intra mode decision in H.264 I frame video coding, and a linear SSIM distortion model is firstly proposed and SSIM-based rate distortion cost function for intra mode decision is defined. Furthermore, a content adaptive frame layer Lagrange multiplier adjustment scheme is proposed to balance the tradeoff between rate and SSIM distortion better. Experimental results show that, the proposed method encodes image structural information more effectively and thus acquires better perceptual quality and subjective RDO performance compared with objective distortion-based RDO method. Under the same perceptual quality, our scheme achieves about 8·03% I frame bit rate reduction on average for various sequences over MSE-based RDO employed in JM reference software.