River Flow Estimation and Forecasting by Using Two Different Adaptive Neuro-Fuzzy Approaches

This paper demonstrates the application of two different adaptive neuro-fuzzy (ANFIS) techniques for the estimation of monthly streamflows. In the first part of the study, two different ANFIS models, namely ANFIS with grid partition (ANFIS-GP) and ANFIS with sub clustering (ANFIS-SC), were used in one-month ahead streamflow forecasting and the results were evaluated. Monthly flow data from two stations, the Besiri Station on the Garzan Stream and the Baykan Station on the Bitlis Stream in the Firat-Dicle Basin of Turkey were used in the study. The effect of periodicity on the model’s forecasting performance was also investigated. In the second part of the study, the performance of the ANFIS techniques was tested for streamflow estimation using data from the nearby river. The results indicated that the performance of the ANFIS-SC model was slightly better than the ANFIS-GP model in streamflow forecasting.     

Measurement and analysis of the stress distribution during die compaction using neutron diffraction

The full axisymmetric stress state of a granular material undergoing compaction in a cylindrical die has been measured using a technique based on neutron powder diffraction. This technique allowed the detailed distribution of stress to be measured in situ, deep within a copper powder inside a solid die. Four components of normal strain were measured over a radial cross section. These components consisted of the axial, radial, hoop and an off-axis strain in the axial-radial direction. This allowed for the reconstruction of the full axisymmetric stress tensor as a distribution over the radial cross section. Many interesting features were observed in this distribution, such as exponential decay of the axial stress (described by Janssen in Zeitschrift des Vereines duetscher Ingenieure 39:1045, 1895), and highly localised regions of high shear stress. The potential of this type of data in the validation of numerical models is discussed.     

Nanoscale communication with molecular arrays in nanonetworks

Molecular communication is a promising nanoscale communication paradigm that enables nanomachines to exchange information by using molecules as communication carrier. Up to now, the molecular communication channel between a transmitter nanomachine (TN) and a receiver nanomachine (RN) has been modeled as either concentration channel or timing channel. However, these channel models necessitate exact time synchronization of the nanomachines and provide a relatively low communication bandwidth. In this paper, the Molecular ARray-based COmmunication (MARCO) scheme is proposed, in which the transmission order of different molecules is used to convey molecular information without any need for time synchronization. The MARCO channel model is first theoretically derived, and the intersymbol interference and error probabilities are obtained. Based on the error probability, achievable communication rates are analytically obtained. Numerical results and performance comparisons reveal that MARCO provides significantly higher communication rate, i.e., on the scale of 100 Kbps, than the previously proposed molecular communication models without any need for synchronization. More specifically, MARCO can provide more than 250 Kbps of molecular communication rate if intersymbol time and internode distance are set to 2 μs and 2 nm, respectively.     

Adversarial security mitigations of mmWave beamforming prediction models using defensive distillation and adversarial retraining

International Journal of Information Security - The design of a security scheme for beamforming prediction is critical for next-generation wireless networks (5G, 6G, and beyond). However, there is...     

Theoretical and experimental investigation of the W-Al-B and Mo-Al-B systems to approach bulk WAlB synthesis

MAB phases are a family of ternary transition metal borides with a layered crystal structure, that provides them with properties likely to be suitable for applications within extreme environments. Here, we report a computational and experimental examination of the W-Al-B system compared to the isostructural Mo-Al-B system. Utilising DFT calculations, WAlB and MoAlB were found to be thermodynamically favourable compared to their most stable competing phases, with respective total energy differences of -0.15 eV and -0.28 eV at 0 K. Partial substitution of W on the Mo-site of MoAlB was observed for certain solid solution compositions. The experimental results indicate that synthesis of (Mo,W)AlB compounds is driven by in-situ formation of metal boride solid solutions, (Mo,W)B, which further react with Al, Mo-Al, W-Al or (Mo,W)-Al compounds to obtain the MAB phase structure. Finally, reactive hot-pressing was shown to be a promising avenue for the production of dense engineering (Mo,W)AlB-containing components.     

Defect-Enhanced Polarization Switching in the Improper Ferroelectric LuFeO3

Results of switching behavior of the improper ferroelectric LuFeO₃ are presented. Using a model set of films prepared under controlled chemical and growth-rate conditions, it is shown that defects can reduce the quasi-static switching voltage by up to 40% in qualitative agreement with first-principles calculations. Switching studies show that the coercive field has a stronger frequency dispersion for the improper ferroelectrics compared to a proper ferroelectric such as PbTiO₃. It is concluded that the primary structural order parameter controls the switching dynamics of such improper ferroelectrics.     

Influence of Hydrostatic Pressure on the t→o Transformation in Mg-PSZ Studied by In Situ Neutron Diffraction

The influence of hydrostatic pressure on the t → o transformation in Mg-PSZ has been studied using a series of neutron diffraction measurements on samples cooled to cryogenic temperatures. A hydrostatic pressure of 400 MPa led to the t → o onset temperature being depressed by 75 K, and the yield of o phase at the base temperature (40 K) being halved. This lends support to the notion that the t particles in this system are predisposed to undergo the t → o transformation by thermal expansion mismatch stresses. It is estimated from thermal expansion data that the mismatch stresses could be as high as 760 MPa along the c -axis of the tetragonal precipitates and that the mismatch strains are qualitatively very similar to the transformation strains for the t → o transformation. It is proposed that the critical factor in determining the transformation path ( t → o vs t → m ) is the presence, in multiphase systems, of a coherent interface between the t phase and the surrounding phases.     

Elastic Constants of Tetragonal Zirconia Measured by a New Powder Diffraction Technique

Elastic constants for 12 mol% Ce-doped tetragonal zirconia have been determined from peak shifts in neutron diffraction patterns recorded under applied uniaxial stress. When these diffraction data are combined with a measured value of Young's modulus, a complete set of elastic constants is obtained. The values are c ₁₁= 327, c ₁₂= 100, c ₁₃= 62, c ₃₃= 264, c ₄₄= 59, and c ₆₆= 64 (units: GPa). These are the first reported results using a new technique for the measurement of elastic constants for anisotropic materials via neutron diffraction measurements on polycrystalline samples.     

Viscous flow of medieval cathedral glass

A popular urban legend concerns the apparent flow of stained glass windows in medieval cathedrals, where the glass windows are commonly observed to be thicker at the bottom than they are at the top. Advances in glass transition theory and experimental characterization techniques now allow for us to address this urban legend directly. In this work, we investigate the dynamics of a typical medieval glass composition used in Westminster Abbey. Depending on the thermal history of the glass, the room temperature viscosity is on the order of 10²⁴ to 10²⁵ Pa·s, about 16 orders of magnitude lower than found in a previous study of soda lime silicate glass. This measurement is in quantitative agreement with a newly derived model for the composition dependence of the nonequilibrium viscosity of glass. Despite this significantly lower value of the room temperature viscosity, the viscosity of the glass is much too high to observe measurable viscous flow on a human time scale. Using analytical expressions to describe the glass flow over a wall, we calculate a maximum flow of ~1 nm over a billion years.     

Adaptive neuro-fuzzy computing technique for suspended sediment estimation

This paper investigates the accuracy of an adaptive neuro-fuzzy computing technique in suspended sediment estimation. The monthly streamflow and suspended sediment data from two stations, Kuylus and Salur Koprusu, in Kizilirmak Basin in Turkey are used as case studies. The estimation results obtained by using the neuro-fuzzy technique are tested and compared with those of the artificial neural networks and sediment rating curves. Root mean squared errors, mean absolute errors and correlation coefficient statistics are used as comparing criteria for the evaluation of the models’ performances. The comparison results reveal that the neuro-fuzzy models can be employed successfully in monthly suspended sediment estimation.