Implementation of the Trigonometric LMS Algorithm using Original Cordic Rotation

The LMS algorithm is one of the most successful adaptive filtering algorithms. It uses the instantaneous value of the square of the error signal as an estimate of the mean-square error (MSE). The LMS algorithm changes (adapts) the filter tap weights so that the error signal is minimized in the mean square sense. In Trigonometric LMS (TLMS) and Hyperbolic LMS (HLMS), two new versions of LMS algorithms, same formulations are performed as in the LMS algorithm with the exception that filter tap weights are now expressed using trigonometric and hyperbolic formulations, in cases for TLMS and HLMS respectively. Hence appears the CORDIC algorithm as it can efficiently perform trigonometric, hyperbolic, linear and logarithmic functions. While hardware-efficient algorithms often exist, the dominance of the software systems has kept those algorithms out of the spotlight. Among these hardware- efficient algorithms, CORDIC is an iterative solution for trigonometric and other transcendental functions. Former researches worked on CORDIC algorithm to observe the convergence behavior of Trigonometric LMS (TLMS) algorithm and obtained a satisfactory result in the context of convergence performance of TLMS algorithm. But revious researches directly used the CORDIC block output in their simulation ignoring the internal step-by-step rotations of the CORDIC processor. This gives rise to a need for verification of the convergence performance of the TLMS algorithm to investigate if it actually performs satisfactorily if implemented with step-by-step CORDIC rotation. This research work has done this job. It focuses on the internal operations of the CORDIC hardware, implements the Trigonometric LMS (TLMS) and Hyperbolic LMS (HLMS) algorithms using actual CORDIC rotations. The obtained simulation results are highly satisfactory and also it shows that convergence behavior of HLMS is much better than TLMS.Comment: 12 pages, 5 figures, 1 table. Published in IJCNC; http://airccse.org/journal/cnc/0710ijcnc08.pdf, http://airccse.org/journal/ijc2010.htm

E-beam lithography and dry processing for submicron fabrication

Imperial Users onl

Design and Optimization of the Injection Molding Process of Glass Fiber Reinforced Polymeric Car Fender Using Computational Simulation

The increasing demand for lightweight and energy-efficient materials in the automotive industry has accelerated the adoption of fiber-reinforced polymer composites. This research presents the design and optimization of the injection molding process for glass fiber-reinforced polymer (GFRP) car fenders using computational simulation. The effects of various gate types and locations on key process parameters, including fiber orientation, volumetric shrinkage, shear rate, and fill time, were investigated using Finite Element Analysis (FEA), Autodesk Moldflow Insight 2024, and MATLAB-based Multi-Criteria Decision-Making (MCMD) techniques. Simulations were conducted across multiple configurations involving three, four, and five gates, with several variations in location. Among all, the four-gate configuration at Location 2 exhibited the most optimal performance. This location demonstrated the lowest shrinkage, stable and consistent fiber orientation, and a manageable shear rate, indicating superior dimensional accuracy and process stability. Fiber orientation was predicted using the Folgar-Tucker model, and the Tsai-Wu criterion was implemented to assess stress distribution without directly estimating mechanical strength. The results determine the crucial role of gate placement in influencing material behavior during molding and reducing common flaws. A simulation-driven method for optimizing injection molding settings is presented in this paper, enabling increased production efficiency, reduced trial-and-error, and improved quality control. The study presents a valuable approach for enhancing the production of GFRP car components by integrating process simulation and decision-making frameworks. These findings can inform future mold design strategies in the automotive sector, leading to improved quality control, reduced trial-and-error processes, and enhanced production efficiency

Characterization of molybdenum black coatings with reference to photothermal conversion of solar energy

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.A study of thermal, structural, electrical and optical characteristics of molybdenum black surface coatings on various substrates has been made. The suitability of these coatings for use as selective absorbers for solar collector applications has been assessed. Molybdenum black (Mo black) coatings were prepared by electrodeposition (on aluminium) and a chemcial conversion method (on zinc and electroplated cobalt on nickel plated copper substrates). The solar absorptancer (αs) and thermal emittances (εth) of the coatings were determined from room temperature spectral reflectance measurements in the solar (0.3 to 2.5μm) and infrared regions (2.5 to 50 μm) respectively. The effect of different preparation parameters and substrate pretreatments on the spectral selectivity has been investigated in order to optimize the thermal performance. The spectral selectivity is related to the Mo-black coating thickness and surface roughness together with the microstructure, of the substrate and the intermediate layer. Dip coatings on polished zinc have significant selectivity (αs/ εth = 8.4 when αs = 0.76). The absorptance of the dip coatings is increased to 0.87 with εth = 0.13 by chemical etching of zinc prior to coating deposition. For coatings on electroplated cobalt on nickel plated copper (cobalt (NC) substrate), an absorptance as high as 0.94 has been obtained with an emittance value 0.3. By using an addition agent in the plating solution of cobalt the high emittance can be reduced to 0.1 with αs = 0.91 giving a coating with a relatively high efficiency (82.5%) for photo-thermal energy conversion. A study of the surface composition and microstructure of the coatings has been made using scanning and transmission electron microscopy together with electron diffraction, X-ray diffraction and X-ray photoelectron spectroscopy. The structural investigations indicate that Mo-black coatings contain polycrystals of orthorhombic Mo4O11 with a small proportion of Ni(OH)2. Presence of water and also Mo4O11 in the coatings are evident from IR spectroscopy study. The bandgap of the coating has been determined from optical transmission spectra (1.66 eV) and also from reflectance spectra (0.85 eV). The discrepancy between these two values has been discussed. The refractive indices of the coatings have also been estimated. The band gaps and refractive indices are found to be related to the spectral selectivity of the coatings. The durability test of the coatings shows that the coatings on etched zinc are more resistant to heat treatment than the coatings on unetched zinc. The coatings on cobalt (NC) substrates also show good stability for relatively short periods at temperatures ~400ºC. A study of the electrical properties of Mo-black coatings suggests that at electrical field strengths (greater than 106v/m the dominant conduction process is of the Poole-Frenkel type. The activation energy of the conduction process has been estimated to be -0.56 eV at higher temperatures. The effect of heat treatment on the electrical properties of the coatings has been examined. The dielectric constant of Mo-black has been estimated from A. C. measurements. At high frequency (20 kHz) the value of the dielectric constant is about 4.0.Association of Commonwealth Universities; Department of Mechanical Engineering, Brunel Universit

Determination of pond water quality for aquaculture and ecosystem management

Fish is the main source of animal protein for the common people of Bangladesh. About 37% of the inland fishes are obtained from the closed water fish culture where ponds play vital roles in the production system. The present study was carried out to determine the water quality (physico-chemical and biological factors) of five uncultivated or under cultivated ponds in the Chittagong University campus, Bangladesh, for aquaculture and ecosystem management. Temperature, pH, EC, BOD, COD, TSS, turbidity, NO2-, PO4 -, free CO2, CO3 -, HCO3-, Cl-, total viable bacterial count and total coliform were determined. Isolation and identification of Escherichia coli and Salmonella sp. from the water samples were performed to investigate the antibiotic sensitivity. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against ciprofloxacin was also investigated. The findings reveal that there was no significant difference in temperature (19°C to 20°C), pH (6.7 to 7.4), electrical conductivity and Cl- values in the water among the ponds and that was within the range of the requirements for the fish cultivation. Both turbidity and total dissolved solids was highest in the uncultivated botanical garden pond 2 (BGP2). BOD, COD, NO2- , PO 4-2, HCO3-, and free CO2 concentration was beyond the permissible limits for aquaculture. Total viable count and total coliform ranged from 1.3 × 10 4 to 6.6 × 10 5 cfu ml-1 and from 0.0205×10 2 to 1.10×10 2 ml-1 respectively, among the ponds where both these parameters were highest in the naturally polluted BGP2. Most of the isolated E. coli and Salmonella sp. were sensitive but few showed resistance against the antibiotics, especially in BGP1, where fishes were cultivated commercially

GWAS Meta-Analysis: Methodology and Application to Human Meiotic Recombination

Human meiotic recombination is critical to successful human reproduction and to maintain genetic diversity. Recombination anomalies are associated with aberrant meiotic outcomes with significant consequences. One important method for studying recombination is genome-wide association studies (GWAS) of recombination phenotypes. Because such studies require nuclear or three-generation family samples that have been genotyped on GWAS chips, the number of suitable datasets is limited. The goal of this dissertation is to develop methods for increasing the available sample sizes for GWAS of recombination phenotypes. We developed two different approaches for increasing sample size. First, we made it possible to include additional family types in the analysis. We developed methods for scoring recombination for half-sibling pedigrees and three generation pedigrees with ungenotyped individuals. Second, we developed a regionally smoothed meta-analysis method for GWAS data, which will allow the combination datasets that have been genotyped on different chips. This method will help increase available sample sizes for recombination studies, but is also applicable to all GWAS studies. The public health significance of this work is that our developments will allow us to find new genes that control recombination and more information about already-known genes. This information can be used for improved treatment and prevention of the consequences of aberrant recombination, including infertility and births with significant chromosomal anomalies

Isotopic Evaluation on Nitrogen Reduction in Mangrove Ecosystems of Okinawa, Japan

2020東京農業大

Joint workload scheduling and BBU allocation in cloud-RAN for 5G networks

Copyright 2017 ACM. Cloud-radio access network (C-RAN) emerges as a solution to satisfy the demand for a diverse range of applications, massive connectivity, and network heterogeneity. C-RAN uses central cloud network for processing user requests. Efficient management of cloud resources (e.g., computation and transmission resources) is one of the important challenges in C-RAN. In this paper, we investigate a joint workload scheduling and baseband unit (BBU) allocation in Cloud-RAN for 5G networks. First, we establish a queueing model in C-RAN. We then formulate an optimization problem for joint workload scheduling and BBU allocation with the aim to minimize mean response time and aggregate power. Queueing stability and workload conservation constraints are considered in the optimization problem. To solve this problem, we propose an energy efficient joint workload scheduling and BBU allocation (EE-JWSBA) algorithm using the concept of queueing theory. The EE-JWSBA algorithm is evaluated via simulations by considering three different scheduling weights (e.g., random, normalized, and upper limit). Simulation results demonstrate the effectiveness of proposed scheme using different scheduling weights

Methionine and Glycine Stabilize Mitochondrial Activity in Sake Yeast During Ethanol Fermentation

Dodatak aminokiselina u fermentacijsku podlogu utječe na rast i aktivnost kvasca, a zadržavanje aktivnosti mitohondrija tijekom alkoholnog vrenja je kritično za aktivnost pivskog kvasca. Međutim, mehanizam djelovanja aminokiselina u fermentacijskoj podlozi i njihov utjecaj na aktivnost mitohondrija pivskog kvasca tijekom vrenja još uvijek nije poznat. U ovom radu smo utvrdili da aminokiseline u fermentacijskoj podlozi, osobito metionin i glicin, stabiliziraju aktivnost mitohondrija kvasca tijekom proizvodnje pića sake. Pomoću mutanta atg32△, koji ima narušenu aktivnost mitohondrija, istražili smo aminokiseline koje povećavaju aktivnost mitohondrija kvasca tijekom vrenja. Identificirali smo metionin i glicin kao aminokiseline koje bi mogle povećati aktivnost mitohondrija kvasca tijekom proizvodnje pića sake. Da bismo to potvrdili, izmjerili smo količinu reaktivnih oblika kisika u kvascu nakon vrenja u podlozi s metioninom i glicinom. Kvasac koji je fermentirao u podlozi s metioninom i glicinom zadržao je relativno veliku količinu reaktivnih oblika kisika u usporedbi s kvascem koji je fermentirao u podlozi bez dodatka aminokiselina. Osim toga, stanice koje su fermentirale u podlozi s dodatkom metionina imale su različit metabolom od stanica koje su fermentirale u podlozi bez dodatka aminokiseline. Rezultati pokazuju da određene aminokiseline, poput metionina i glicina, stabiliziraju aktivnost mitohondrija kvasca tijekom proizvodnje pića sake i na taj način upravljaju aktivnošću kvasca.Addition of amino acids to fermentation media affects the growth and brewing profiles of yeast. In addition, retaining mitochondrial activity during fermentation is critical for the fermentation profiles of brewer’s yeasts. However, a concrete mechanism linking amino acids in fermentation media with mitochondrial activity during fermentation of brewer’s yeasts is yet unknown. Here, we report that amino acids in fermentation media, especially methionine (Met) and glycine (Gly), stabilize mitochondrial activity during fermentation of sake yeast. By utilizing atg32Δ mutant sake yeast, which shows deteriorated mitochondrial activity, we screened candidate amino acids that strengthened the mitochondrial activity of sake yeast during fermentation. We identified Met and Gly as candidate amino acids that fortify mitochondrial activity in sake yeast during fermentation. To confirm this biochemically, we measured reactive oxygen species (ROS) levels in sake yeast fermented with Met and Gly. Yeast cells supplemented with Met and Gly retained high ROS levels relative to the non-supplemented sake yeast. Moreover, Met-supplemented cells showed a metabolome distinct from that of non-supplemented cells. These results indicate that specific amino acids such as Met and Gly stabilize the mitochondrial activity of sake yeast during fermentation and thus manipulate brewing profiles of yeast

Genome-wide association Scan of dental caries in the permanent dentition

Background: Over 90% of adults aged 20 years or older with permanent teeth have suffered from dental caries leading to pain, infection, or even tooth loss. Although caries prevalence has decreased over the past decade, there are still about 23% of dentate adults who have untreated carious lesions in the US. Dental caries is a complex disorder affected by both individual susceptibility and environmental factors. Approximately 35-55% of caries phenotypic variation in the permanent dentition is attributable to genes, though few specific caries genes have been identified. Therefore, we conducted the first genome-wide association study (GWAS) to identify genes affecting susceptibility to caries in adults. Methods: Five independent cohorts were included in this study, totaling more than 7000 participants. For each participant, dental caries was assessed and genetic markers (single nucleotide polymorphisms, SNPs) were genotyped or imputed across the entire genome. Due to the heterogeneity among the five cohorts regarding age, genotyping platform, quality of dental caries assessment, and study design, we first conducted genome-wide association (GWA) analyses on each of the five independent cohorts separately. We then performed three meta-analyses to combine results for: (i) the comparatively younger, Appalachian cohorts (N = 1483) with well-assessed caries phenotype, (ii) the comparatively older, non-Appalachian cohorts (N = 5960) with inferior caries phenotypes, and (iii) all five cohorts (N = 7443). Top ranking genetic loci within and across meta-analyses were scrutinized for biologically plausible roles on caries. Results: Different sets of genes were nominated across the three meta-analyses, especially between the younger and older age cohorts. In general, we identified several suggestive loci (P-value ≤ 10E-05) within or near genes with plausible biological roles for dental caries, including RPS6KA2 and PTK2B, involved in p38-depenedent MAPK signaling, and RHOU and FZD1, involved in the Wnt signaling cascade. Both of these pathways have been implicated in dental caries. ADMTS3 and ISL1 are involved in tooth development, and TLR2 is involved in immune response to oral pathogens. Conclusions: As the first GWAS for dental caries in adults, this study nominated several novel caries genes for future study, which may lead to better understanding of cariogenesis, and ultimately, to improved disease predictions, prevention, and/or treatment