Towards the Shifting of 5G Front Haul Traffic on Passive Optical Network

Wireless Personal Communications - Centralized radio access network (CRAN) is getting considerable attention in 5G radio access network infrastructure because of supporting deployments of small...     

Bayesian estimation and prediction for Burr‐Rayleigh mixture model using censored data

In this study, Burr‐XII and Rayleigh distributions are combined to form a new mixture model that is considered to model heterogeneous data. Our objective is to estimate parameters of the proposed mixture model using Bayesian technique under type‐I censoring. Bayesian parameter estimation for the said mixture model is conducted by using informative priors, ie, gamma and squared root inverted gamma (SRIG) as well as noninformative prior, ie, Jeffrey's prior. Squared error loss function (SELF) and quadratic loss function (QLF) are employed to obtain and Bayes estimators. Properties of the proposed Bayes estimators are highlighted through a simulation study. When prior distributions and loss functions utilized in the study are compared in terms of posterior risks, informative prior found to be more suitable and decision turns out to be in favor of QLF. Prediction limits for the single sample case and two sample case are obtained to provide an insight into future sample data. Application of the proposed model is also elaborated using a real‐life example.     

Dynamic analysis and open‐loop start‐up of an integrated radiant syngas cooler and steam methane reformer

The transient performance of an integrated radiant syngas cooler (RSC) of an entrained‐bed gasifier and steam methane reformer (SMR) is investigated. Base‐case designs using either co‐current or counter‐current configurations are subjected to operating transients to evaluate the feasibility to transition to new steady states. Each system, under open loop, is subjected to changes in key variables of the SMR feed on the tube side and disturbances to variables of the coal‐derived syngas on the RSC side to determine the dynamics and stability of the integrated system. The results indicate that the co‐current configuration is flexible to move to new operating steady states and more safe than the counter‐current configuration, although it provides less cooling and has poorer methane conversion. The variables likely to violate the design limit in the event of a disturbance are identified. A start‐up procedure is also established based on industrial practices employed for entrained‐bed gasifiers and methane reformers. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1602–1619, 2017     

A multi-scale dynamic two-dimensional heterogeneous model for catalytic steam methane reforming reactors

A multi-scale, dynamic, two-dimensional, heterogeneous model for catalytic steam methane reforming (SMR) is developed. The model, derived from first principles, accounts for diffusional limitations for both mass and energy within large industrial-scale catalyst particles. The diffusional limitations have been incorporated, not by the conventional method of computing the effectiveness factor, but by accounting for the transfer of species as a function of the concentration and temperature gradients existing between the gas phase and catalyst surface along the reactor length. The model has been validated with available industrial steady-state data from literature. The model was then used to study the dynamic behaviour of key variables and the effects of feed disturbances on catalyst core and tube wall temperatures.     

Hierarchically Porous Donut-Like Fe3Ni2Se4 Bimetallic Selenide: An Ultra-High-Rate Anode for Potassium Ions Storage

Transition-metal selenides are considered as one of the promising anode materials for potassium ion batteries (PIBs) due to their high theoretical capacities. However, addressing the issue of irreversibility caused by the large volume changes during potassiation/depotassiation, especially at high rates, remains a major challenge. This challenge is tackled by constructing nickel-iron selenide (NFS) with a unique hierarchically porous donut-like morphology using a simple template-free solvothermal strategy. With the bimetallic strategy and well-designed architecture, the donut-like NFS displays outstanding potassium storage performance, exhibiting a high reversible capacity (458 mAh g⁻¹ even after 100 cycles at a slow rate of 0.1 A g⁻¹), an impressive rate capability up to 10 A g⁻¹ (≈10 mA cm⁻²), and an excellent capacity retention over 1000 cycles at 2 A g⁻¹. By combining theoretical and experimental techniques, a two-stage intercalation-conversion reaction mechanism is put forward. This work provides an effective approach to develop bimetallic selenides electrode materials for applications in PIBs and potentially for other energy storage devices.     

Guided image filtering using data mining and decomposition

Owing to local linear model, guided image filter may contain from ringing artefacts. A modified guided image filter based on data mining techniques and decomposition is proposed in this paper. Image is split into patches, passing through the guided filter, clustered into number of clusters and transformed into compact domain using principal component analysis. Edges are preserved and halo artefacts are removed using detail enhancement based on weighted least square. Simulation results demonstrate the strength of the proposed technique as compared with other techniques especially around the edges where noise and halo artefacts may be present in the image.     

Industry structure modeling for competitive analysis: An integrated AI and systems approach

This paper describes a new approach to model the industry structure that will determine the market share equilibrium in a competitive environment. This approach takes advantage of certain developments in the Expert Systems area in the field of Artificial Intelligence to organize qualitative knowledge of industry structure, and combines such a knowledge base with mathematical systems modeling techniques to develop a market share equilibrium model. The rich structural information embedded in the model makes it potentially a very powerful tool for use in industry assessment and competitive strategy development. One version of the model is implemented in SRI International. The system is fully interactive and is currently used to assess the competitive environment for the polyolefins industry.     

A novel near-infrared fluorescence sensor for detection of thrombin activation in blood

Thrombosis is an important pathophysiologic component of many cardiovascular diseases. Thrombin, a serine protease, plays a central role in thrombosis formation. Detection and imaging of thrombin activity may thus be of considerable biomedical interest. The goal of this study was to design, synthesize, and characterize a novel thrombin-activated near-infrared fluorescence (NIRF) probe. The probe consisted of a thrombin-cleavable peptide spacer (...D-Phe-Pip-Arg...; Pip=pipecolic acid) and contained a terminal fluorescence reporter which was quenched when conjugated to a biocompatible delivery vehicle. A control peptide spacer was synthesized that differed by one amino acid. Following thrombin addition, the probe was activated within minutes. The NIRF signal increased by a factor of 27-fold within 20 minutes, and was inhibited by hirudin, a specific thrombin inhibitor. NIRF optical imaging experiments confirmed rapid activation of the probe in both buffer and human blood. The control probe showed minimal activation in all experiments. In addition to potentially furthering our understanding of thrombin regulation in vivo, the thrombin-activated near-infrared probe may have broad clinical application to the diagnosis of arterial and venous thrombosis.