Weightless neural networks for face recognition

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The interface with the real-world has proved to be extremely challenging throughout the past 70 years in which computer technology has been developing. The problem initially is assumed to be somewhat trivial, as humans are exceptionally skilled at interpreting real-world data, for example pictures and sounds. Traditional analytical methods have so far not provided the complete answer to what will be termed pattern recognition. Biological inspiration has motivated pattern recognition researchers since the early days of the subject, and the idea of a neural network which has self-evolving properties has always been seen to be a potential solution to this endeavour. Unlike the development of computer technology in which successive generations of improved devices have been developed, the neural network approach has been less successful, with major setbacks occurring in its development. However, the fact that natural processing in animals and humans is a voltage-based process, devoid of software, and self-evolving, provides an on-going motivation for pattern recognition in artificial neural networks. This thesis addresses the application of weightless neural networks using a ranking pre-processor to implement general pattern recognition with specific reference to face processing. The evaluation of the system will be carried out on open source databases in order to obtain a direct comparison of the efficacy of the method, in particular considerable use will be made of the MIT-CBCL face database. The methodology is cost effective in both software and hardware forms, offers real-time video processing, and can be implemented on all computer platforms. The results of this research show significant improvements over published results, and provide a viable commercial methodology for general pattern recognition

Evaluation of androgenic activity of allium cepa on spermatogenesis in the rat

Allium cepa (onion) has a beneficial effect on disease treatment worldwide and has been used since ancient times as a medicinal and food source. Recently several reports have shown that onion has high antioxidant activity. As antioxidants have an essential effect on sperm health parameters, we investigated the effect of the fresh juice of onion bulbs on the spermatogenesis cycle in rats. Wistar male rats (n = 30) were allocated into 3 groups, control (n = 10) and two test groups (each of 10). The animals in the test groups were subdivided into groups of 2 that received fresh onion juice equivalent to 0.5 and 1 g/rat/ /day of fresh onion. The fresh onion juice was administered by gavage for 20 consecutive days. The animals were kept in standard conditions. On the twentieth day, the testes of rats in all groups were removed and sperm was collected from the epididymis and was prepared for analysis. Serum total testosterone significantly increased in all the test groups (p < 0.05), and levels of LH significantly increased only in the group that received the high dose of fresh onion juice (p < 0.05), but the level of FSH did not differ between the experimental and control groups. The percentage of sperm viability and motility in both test groups significantly increased (p < 0.05), but the sperm concentration significantly increased only in the group that received the high dose of freshly extracted onion juice (p < 0.05). It was evident that there was no difference on sperm morphology and testis weight in test groups compared to the control group. In our study, freshly prepared onion juice significantly affected the sperm number, percentage of viability, and motility; it seems that using 4 g/kg of freshly prepared onion juice is effective in sperm health parameters

The application of multi-mission satellite data assimilation for studying water storage changes over South America

Constant monitoring of total water storage (TWS; surface, groundwater, and soil moisture) is essential for water management and policy decisions, especially due to the impacts of climate change and anthropogenic factors. Moreover, for most countries in Africa, Asia, and South America that depend on soil moisture and groundwater for agricultural productivity, monitoring of climate change and anthropogenic impacts on TWS becomes crucial. Hydrological models are widely being used to monitor water storage changes in various regions around the world. Such models, however, comes with uncertainties mainly due to data limitations that warrant enhancement from remotely sensed satellite products. In this study over South America, remotely sensed TWS from the Gravity Recovery And Climate Experiment (GRACE) satellite mission is used to constrain the World-Wide Water Resources Assessment (W3RA) model estimates in order to improve their reliabilities. To this end, GRACE-derived TWS and soil moisture observations from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) and Soil Moisture and Ocean Salinity (SMOS) are assimilated into W3RA using the Ensemble Square-Root Filter (EnSRF) in order to separately analyze groundwater and soil moisture changes for the period 2002–2013. Following the assimilation analysis, Tropical Rainfall Measuring Mission (TRMM)’s rainfall data over 15 major basins of South America and El Niño/Southern Oscillation (ENSO) data are employed to demonstrate the advantages gained by the model from the assimilation of GRACE TWS and satellite soil moisture products in studying climatically induced TWS changes. From the results, it can be seen that assimilating these observations improves the performance of W3RA hydrological model. Significant improvements are also achieved as seen from increased correlations between TWS products and both precipitation and ENSO over a majority of basins. The improved knowledge of sub-surface water storages, especially groundwater and soil moisture variations, can be largely helpful for agricultural productivity over South America

Natural candidates for the underlying symmetry of the Higgs field

As a small step toward understanding the nature of the Higgs field, the results of a study on its symmetry structure are announced. First, a toy model for the vacuum of a finite Higgs field (as the underlying field of the Steinberg group ${SU}_2(q^2)$) is developed with the aim of estimating its boson mass scale. Next, to find the actual underlying symmetry of the Higgs field, natural candidates beyond the Standard Model are explored. As a result of the exploration, the Weyl group of $E_8$ in 8 DOF, as well as the Conway group $Co_0$ in 24 DOF, are introduced as the "natural candidates" and the Fischer-Griess monster group in 24 DOF (that also matches the symmetry group of the FLM CFT model with the central charge of 24) is introduced as the "most natural candidate". Then, by applying the latter's specifications (order and the number of DOF) to the toy model, the corresponding boson mass is calculated at $125.4$ GeV, which validated the "most natural candidate". Afterward, replacing ${ SU}_2(q^2)$ by ${SU}_5(q^2)$ in the toy model, for the GUT scale, a prediction of $6.6\times 10^{17}$ GeV (comparable to its conventional scale of $10^{16}$ GeV) is reported. In the last prediction, first, it is observed that to reach a higher scale, the model delicately asks for a candidate with a smaller symmetry. Then, the other two natural candidates' specifications are applied to the toy model and the same value of $1.9\times 10^{19}$ GeV (close to the Planck scale $1.22\times 10^{19}$ GeV) is produced by both. In sum, the results suggest that the post-GUT age having a Fischer-Griess monster structure and the pre-GUT era having a $Co_0$ (or Weyl$(E_8)$) structure are imaginable, where the latter evolves to the former in the GUT epoch

Improved gravity anomaly fields from retracked multimission satellite radar altimetry observations over the Persian Gulf and the Caspian Sea

Satellite radar altimetry observations are used to derive short wavelength gravity anomaly fields over the Persian Gulf and the Caspian Sea, where in situ and ship-borne gravity measurements have limited spatial coverage. In this study the retracking algorithm ‘Extrema Retracking’ (ExtR) was employed to improve sea surface height (SSH) measurements that are highly biased in the study regions due to land contaminations in the footprints of the satellite altimetry observations. ExtR was applied to the waveforms sampled by the five satellite radar altimetry missions: TOPEX/POSEIDON, JASON-1, JASON-2, GFO and ERS-1. Along-track slopes have been estimated from the improved SSH measurements and used in an iterative process to estimate deflections of the vertical, and subsequently, the desired gravity anomalies. The main steps of the gravity anomaly computations involve estimating improved SSH using the ExtR technique, computing deflections of the vertical from interpolated SSHs on a regular grid using a biharmonic spline interpolation and finally estimating gridded gravity anomalies. A remove–compute–restore algorithm, based on the fast Fourier transform, has been applied to convert deflections of the vertical into gravity anomalies. Finally, spline interpolation has been used to estimate regular gravity anomaly grids over the two study regions.Results were evaluated by comparing the estimated altimetry-derived gravity anomalies (with and without implementing the ExtR algorithm) with ship-borne free air gravity anomaly observations, and free air gravity anomalies from the Earth Gravitational Model 2008 (EGM2008). The comparison indicates a range of 3–5 mGal in the residuals, which were computed by taking the differences between the retracked altimetry-derived gravity anomaly and the ship-borne data. The comparison of retracked data with ship-borne data indicates a range in the root-mean-square-error (RMSE) between approximately 1.8 and 4.4 mGal and a bias between 0.4062 and 2.1413 mGal over different areas. Also a maximum RMSE of 4.4069 mGal, with a mean value of 0.7615 mGal was obtained in the residuals. An average improvement of 5.2746 mGal in the RMSE of the altimetry-derived gravity anomalies corresponding to 89.9 per cent was obtained after applying the ExtR post-processing

Integrating satellite soil-moisture estimates and hydrological model products over Australia

Accurate soil-moisture monitoring is essential for water-resource management and agricultural applications, and is now widely undertaken using satellite remote sensing or terrestrial hydrological models’ products. While both methods have limitations, e.g. the limited soil depth resolution of space-borne data and data deficiencies in models, data-assimilation techniques can provide an alternative approach. Here, we use the recently developed data-driven Kalman–Takens approach to integrate satellite soil-moisture products with those of the Australian Water Resources Assessment system Landscape (AWRA-L) model. This is done to constrain the model’s soil-moisture simulations over Australia with those observed from the Advanced Microwave Scanning Radiometer-Earth Observing System and Soil-Moisture and Ocean Salinity between 2002 and 2017. The main objective is to investigate the ability of the integration framework to improve AWRA-L simulations of soil moisture. The improved estimates are then used to investigate spatiotemporal soil-moisture variations. The results show that the proposed model-satellite data integration approach improves the continental soil-moisture estimates by increasing their correlation to independent in situ measurements (∼10% relative to the non-assimilation estimates). Highlights Satellite soil-moisture measurements are used to improve model simulation. A data-driven approach based on Kalman–Takens is applied. The applied data-integration approach improves soil-moisture estimates

Investigating the Effect of Mechanical Activation Parameters on Structural Changes and Leaching Rate of Molybdenite Concentrate

AbstractIn this research, mechanical activation (MA) was employed for leaching rate improvement of molybdenite concentrate in nitric acid media. These experiments were performed in two groups: with and without aluminum oxide (alumina). A full factorial design was used for each group of experiments. Leaching rate increment up to 5 times was observed only in 2hours activation procedure. XRD analysis demonstrated structural disordering in activated MoS2. TEM images showed that particle size has been reduced to nanoscale. The initial powder size was 80% between 2-44μm and dropped to about 10nm and 140nm in MA experiments with and without alumina, respectively. This size reduction would be the main reason of leaching rate enhancement which is more achievable in MA in presence of alumina. The results demonstrate that alumina has a motivating effect in activation procedure to achieve a nanostructure molybdenite. Analysis of variance revealed milling speed is the main parameter in MA without alumina, while, ball to powder ratio is the most important factor in MA procedure in presence of alumina on leaching rate

A study on the dependence of structure of multi-walled carbon nanotubes on acid treatment

In the current research, the role of both concentrated nitric acid and ultrasound waves on oxidation of multi-walled carbon nanotubes (MWNTs) was studied. The functionalized MWCNTs were characterized by transmission electron microscopy (TEM), thermogravimetric analyzer, and Fourier transform infrared spectroscopy (FTIR) techniques. It was found that desirable modifications to MWNTs occurred after acid treatment. Carboxylic acid groups were appeared on the side surfaces of MWNTs. FTIR presented the formation of oxygen-containing groups such as C=O and COOH after modification by concentrated nitric acid. The TEM images showed that the aspect ratio of opened MWCNTs was controlled by both ultrasonic waves and acid treatment time. It was also found that the exposure of about 4 h in nitric acid led to the highest removal of the impurities with the least destructive effect

Fabrication of Iron Aluminide Coatings (Fe3Al and FeAl3) on Steel Substrate by Self-Propagating High Temperature Synthesis (SHS) Process

Iron aluminides (Fe3Al and FeAl3) coatings were fabricated on a steel substrate by self-propagating high temperature synthesis (SHS) method. Raw materials, Fe and Al powders, were mixed at two different stoichiometry ratios (3:1 and 1:3). The mixtures and the substrate were placed in a furnace at 950 °C to ignite the SHS process. Coating phases were investigated using X-ray diffraction (XRD) and Energy Dispersive Spectroscopy (EDS). The microstructure of the coatings was analyzed with optical microscopy (OM) and scanning electron microscopy (SEM). The results confirmed that it is possible to produce Fe3Al and FeAl3 coatings on steel substrate using SHS method. In addition, the results show that the coatings were composed of two different phases and their microstructures were non-porous and dense. Wear resistance of the coatings were higher than that of the substrate

The 2019–2020 rise in lake victoria monitored from space: exploiting the state-of-the-art grace-fo and the newly released era-5 reanalysis products

During the period 2019–2020, Lake Victoria water levels rose at an alarming rate that has caused various problems in the region. The influence of this phenomena on surface and subsurface water resources has not yet been investigated, largely due to lack of enough in situ measurements compounded by the spatial coverage of the lake’s basin, incomplete/inconsistent hydrometeorological data, and unavailable governmental data. Within the framework of joint data assimilation into a land surface model from multi-mission satellite remote sensing, this study employs the state-of-art Gravity Recovery and Climate Experiment follow-on (GRACE-FO) time-variable terrestrial water storage (TWS), newly released ERA-5 reanalysis, and satellite radar altimetry products to understand the cause of the rise of Lake Victoria on the one hand, and the associated impacts of the rise on the total water storage compartments (surface and groundwater) triggered by the extreme climatic event on the other hand. In addition, the study investigates the impacts of large-scale ocean–atmosphere indices on the water storage changes. The results indicate a considerable increase in water storage over the past two years, with multiple subsequent positive trends mainly induced by the Indian Ocean Dipole (IOD). Significant storage increase is also quantified in various water components such as surface water and water discharge, where the results show the lake’s water level rose by ∼ 1.4 m, leading to approximately 1750 gigatonne volume increase. Multiple positive trends are observed in the past two years in the lake’s water storage increase with two major events in April–May 2019 and December 2019–January 2020, with the rainfall occurring during the short rainy season of September to November (SON) having had a dominant effect on the lake’s rise