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Groundnut spread likability, sensory properties, and intent to pay for quality certification
No full textQuality-certified, nutritious novel groundnut spread has great commercialization possibilities due to evolving urban lifestyles in Africa, but lack of information about likability, sensory attributes, and consumer safety awareness is a severe barrier for small enterprises. This paper examines a novel groundnut spread, made of sorted kernels deemed free of aflatoxin, intended for use on bread in a fashion similar to groundnut paste or groundnut butter, but with modified sensory characteristics. In particular, it seeks to measure the effects of sensory attributes of the novel spread on the intent to pay for safety certification and the role of consumer awareness of aflatoxin. A novel spread was prepared with groundnut paste from sorted kernels (to eliminate the risk of aflatoxin contamination) and cocoa. Adults intercepted at Ghana’s International Fair in 2012 volunteered to sample the spread and complete a questionnaire. Results from a tasting panel of untrained participants established that sensory attributes and panellist characteristics are relevant to the intent to pay for quality certification. Spread likability, aroma, education, knowledge about aflatoxin, packaging and being married were identified as major factors increasing the probability of intent to pay for quality certification whereas young age and the presence of children in a household lowered the probability. Results also identified income, education level, and having young children at home as increasing the chances of knowing about aflatoxin. Groundnut paste available in Ghana is often contaminated by aflatoxin as it is in other countries in the region and consumers cannot visually assess paste quality. Under the circumstances, quality certification is necessary
Predicting Split Decisions in MPEG-2 to HEVC Video Transcoding
No full textThis paper proposes learning-based approaches for transcoding MPEG-2 video into HEVC. In the training mode of the transcoder, mappings between extracted features and split decisions are calculated. While in the transcoding mode, the split decisions of coding units of the HEVC video are predicted. Two formulations are proposed for the prediction of split decisions based on multi model and multi-tier solutions. In the former solution, multi models are generated based on the total number of split flags in a coding unit. While in the latter solution, split decisions are modelled at three different coding depths. The proposed solutions are evaluated in terms of excessive bitrate, drop in PSNR, classification accuracy, model generation time and transcoding speedup. It is shown that the multi-tier solution maintains the rate-distortion behaviour of full re-encoding at the expense of lower gain in transcoding speedup. In comparison to existing work, it is shown that the proposed solutions offer a significant enhancement in terms of rate-distortion performance and classification accuracy
A Novel Stochastic Dynamic Modeling for PV Systems Considering Dust and Cleaning Effects
No full textA Master of Science thesis in Electrical Engineering by Armaghan Cheema entitled, “A Novel Stochastic Dynamic Modeling for PV Systems Considering Dust and Cleaning Effects”, submitted in November 2020. Thesis advisor is Dr. Mostafa Farouk Shaaban and thesis co-advisor is Dr. Mahmoud Hamed Ismail Ibrahim. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Stochastic photovoltaic (PV) modeling is essential for the long-term planning of renewable power generation. One of the most prevalent problems that PV systems face is the accumulation of dust on the PV panel surface that negatively impacts the output power. Wind speed along with other weather variables including relative humidity, temperature, and precipitation are some of the major factors that contribute to dust accumulation. Unlike the available models in the literature, this thesis presents a novel dynamic model of the PV output power profile considering the effect of dust accumulation using a Markov chain model. The proposed model is composed of three stages and it incorporates the seasonal variations in the weather conditions as well as the desired cleaning frequency, which affects the overall energy yield of the PV system. The first stage is the data acquisition and processing stage where the raw data is discretized and categorized. The second stage utilizes the outcome of the first stage in a Markovian Chain model, which is the core of the overall model. The third and final stage is the cumulative distribution function generation, which is generated using the probability mass function output of the Markov Chain simulation. The outcome of the model can be described as virtual scenarios, which can help the investors to decide on the optimal size of the PV system and the optimal cleaning frequency for each season subject to some constraints. The model outcome shows an error of less than 5% when compared to actual data collected from the field without cleaning. Various case studies are presented to show the effectiveness of the proposed model and its benefits.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Joshi’s Split Tree for Option Pricing
No full textIn a thorough study of binomial trees, Joshi introduced the split tree as a two-phase binomial tree designed to minimize oscillations, and demonstrated empirically its outstanding performance when applied to pricing American put options. Here we introduce a “flexible” version of Joshi’s tree, and develop the corresponding convergence theory in the European case: we find a closed form formula for the coefficients of 1/n and 1/n³/² in the expansion of the error. Then we define several optimized versions of the tree, and find closed form formulae for the parameters of these optimal variants. In a numerical study, we found that in the American case, an optimized variant of the tree significantly improved the performance of Joshi’s original split tree.American University of Sharja
On n-semiprimary ideals and n-pseudo valuation domains
No full textLet R be a commutative ring with 1 ≠ 0 and n a positive integer. A proper ideal I of R is an n-semiprimary ideal of R if whenever x^n y^n ∈ I for x, y ∈ R, then x^n ∈ I or y^n ∈ I. Let R be an integral domain with quotient field K. A proper ideal I of R is an n-powerful ideal of R if whenever x^n y^n ∈ I for x, y ∈ K, then x^n ∈ R or y^n ∈ R; and I is an n-powerful semiprimary ideal of R if whenever x^n y^n ∈ I for x, y ∈ K, then x^n ∈ I or y^n ∈ I. If every prime ideal of R is an n-powerful semiprimary ideal of R, then R is an n-pseudo-valuation domain (n-PVD). In this paper, we study the above concepts and relate them to several generalizations of pseudo-valuation domains
Beamforming Techniques for the Frequency Diverse Array
No full textA Master of Science thesis in Electrical Engineering by Yazan Youssef entitled, “Beamforming Techniques for The Frequency Diverse Array”, submitted in May 2020. Thesis advisors are Dr. Hasan Mir and Dr. Lutfi Albasha. Soft copy is available (Thesis, Approval Signatures, Completion Certificate, and AUS Archives Consent Form).One of the primary advantages of using a system that employs multiple antennas is the ability to perform spatial beamforming, wherein a phase shift is applied across each of the antenna elements in order to electronically steer the transmitted signal in a desired direction. This architecture is known as a phased array, and much work has been done in order to determine the optimal configuration of the phase shifts that yield a beampattern that exhibits a narrow mainlobe and low sidelobe levels, thus ensuring that the radiated signal is concentrated in the desired direction. However, a phased array is limited in providing control over the beampattern in the angle domain only. Recently, a novel multiple antenna architecture known as the frequency diverse array (FDA) was proposed in which a phase shift and a frequency shift is applied across each of the antenna elements. The beampattern that arises from such an architecture exhibits a dependence on angle, range, and time. Due to the time dependence, existing methods for FDA beamforming will only illuminate a desired spatial location at a specific moment in time. To overcome this problem, a solution has recently been proposed wherein a subarray based FDA receiver architecture consisting of a series of mixers and filters is used in order to perform what is termed as equivalent transmit beamforming. This thesis further develops the equivalent transmit beamforming paradigm at the FDA receiver with a novel and simplified method for achieving a time-invariant beampattern that illuminates the desired spatial location. To reduce the dimensionality of the optimization problem, a fixed form of the frequency offset is proposed based on a novel recursive frequency increment structure. The problem of determining the array weight coefficients in order to steer the array sensitivity to a desired spatial location is formulated as a convex optimization problem that can be easily solved using interior-point methods. Comprehensive simulation results show that the proposed architecture exhibits a beampattern with sidelobe levels comparable to existing methods but with a mainlobe width that has been reduced by nearly an order of magnitude.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
A Comparative Study for Various Coil Geometries in Electric Vehicle Wireless Charging System.
No full textA Master of Science thesis in Electrical Engineering by Hanin Hassan Kabalan entitled, “A Comparative Study for Various Coil Geometries in Electric Vehicle Wireless Charging System.”, submitted in November 2020. Thesis advisors are Dr. Mohamed Hassan and Dr. Ahmed Osman-Ahmed. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Inductive coupling wireless power transfer technology is gaining interest in recent years, especially in the field of wireless charging. Range limitations and charging of electric vehicles are major concerns in the modern intelligent transportation systems. A systematic approach to design the inductive link power pads is presented in detail and the Society of Automotive Engineers (SAE) recommended practice J2954 is followed for designing the physical dimension of these power pads. In this thesis, a comparative study for the design of different coil geometries considered for EV’s wireless charging systems is carried out. In particular, a comparative performance analysis is conducted for rectangular, Double-D (DD), Double-D Quadrature (DDQ), and Bipolar (BP) power pads. This study also aims at showing how design aspects, height and vertical displacement affect the coupling behavior and misalignment tolerance while investigating the effect of the different parameters on the magnetic null phenomenon. Based on the simulation results, the geometries in which DD and DDQ coils are considered for primary and secondary coils respectively provide the highest coupling factor and the highest inductive link efficiency at various alignment conditions over a range of horizontal displacement from -800 mm to +800 mm lateral misalignment, while having the minimum charging pads weight, when compared to DD coils. A commercial electromagnetic simulation software called (ANSYS Maxwell) was adopted to simulate different coil structures and evaluate the performance of the inductive link. It is concluded that turn-to-turn spacing has the most dominant effect on the coupling performance at a fixed wire diameter. The power pad combinations such as DD_DD, and DD_DDQ are considered the best combinations that gives the best coupling performance for misalignment conditions. Rectangular power pad combined with non-polarized geometries is the proper geometry combination for static charging in perfect alignment conditions. The conducted analysis reveals that the existence of ferrite core is necessary to enhance the inductive link overall performance.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Bioluminescence Imaging Applications in Cancer: A Comprehensive Review
No full textBioluminescence imaging (BLI), an optical preclinical imaging modality, is an invaluable imaging modality due to its low-cost, high throughput, fast acquisition times, and functional imaging capabilities. BLI is being extensively used in the field of cancer imaging, especially with the recent developments in genetic-engineering, stem cell, and gene therapy treatments. The purpose of this paper is to provide a comprehensive review of the principles, developments, and current status of BLI in cancer research. This paper covers the fundamental BLI concepts including BLI reporters and enzyme-substrate systems, data acquisition, and image characteristics. It reviews the studies discussing the use of BLI in cancer research such as imaging tumor-characteristic phenomena including tumorigenesis, metastasis, cancer metabolism, apoptosis, hypoxia, and angiogenesis, and response to cancer therapy treatments including chemotherapy, radiotherapy, immunotherapy, gene therapy, and stem cell therapy. The key advantages and disadvantages of BLI compared to other common imaging modalities are also discussed
Organizational forgetting Part I: a review of the literature and future research directions
No full textThe purpose of this paper is to systematically review and synthesize the literature on organizational forgetting. A systematic literature review approach was used to synthesize current theoretical and empirical studies on organizational forgetting. The review and synthesis of the literature revealed that the organizational forgetting literature is fragmented, with studies conducted across disparate fields and using different methodologies; two primary modes (i.e. accidental and purposeful) and three foci (i.e. knowledge depreciation, knowledge loss and unlearning) define current organizational forgetting literature; and the factors that influence organizational forgetting can be grouped into four clusters related to individuals, processes, tools and organizational context. This literature review has limitations related to time span coverage and journal article accessibility. This paper offers an integrative view of organizational forgetting that proposes a holistic and multilevel research approach and systematic synthesis of organizational forgetting research
Using the Age and Metallicity of 8 Star Clusters to confirm the Chemical Enrichment History of the LMC
No full textIn this paper, we find the ages and metallicities of 8 Large Magellanic Cloud (LMC) star clusters obtained from integrated light spectra and use them to obtain the Chemical Enrichment History of the host galaxy. Our results are in good agreement with those obtained from resolved studies. This confirms that this method can be used for far away galaxies for which their star clusters are not resolved