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Articles 63271 - 63300 of 197438

Full-Text Articles in Engineering

Energetic And Exergetic Analysis Of A Heat Pipe Evacuated Tube Solar Collector Using Mwcnt/Water Nanofluid, Mahmoud Eltaweel, Ahmed A. Abdel-Rehim Jan 2020

Energetic And Exergetic Analysis Of A Heat Pipe Evacuated Tube Solar Collector Using Mwcnt/Water Nanofluid, Mahmoud Eltaweel, Ahmed A. Abdel-Rehim

Mechanical Engineering

Increasing the energy demand and the limited availability of conventional energy sources are the main challenges to secure the human future. Solar energy is an attractive source of energy to ensure the sustainability of energy in this world for now and for the future. Evacuated tube solar collector is a solar thermal collector mostly used for domestic applications. The replacement of the working fluid with nanofluid can enhance the heat transfer even for low temperature applications. The effect of multi-walled carbon nanotubes and water nanofluid as working fluid in evacuated tube solar collector is used to experimentally investigate the energy …

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An Evaluation Of Ground-Freezing Methods In The Zone Of Discontinuous Permafrost, Northwest Territories, Elzbieta Mastej Ms Jan 2020

An Evaluation Of Ground-Freezing Methods In The Zone Of Discontinuous Permafrost, Northwest Territories, Elzbieta Mastej Ms

Theses and Dissertations (Comprehensive)

Northwestern Canada is one of the most rapidly warming regions on Earth. The southern limit of the discontinuous permafrost zone is highly sensitive to small climatic fluctuations and presently experiencing a rapid landscape change due to accelerated permafrost thaw, which is further exacerbated by anthropogenic disturbances such as seismic exploration. Recent research has begun to examine both natural and mechanical approaches to minimize permafrost loss, although the utility of such methods in peatland environments is not well understood. This study explored the efficiency of natural and artificial ground cooling processes in a peatland environment by evaluating snow exclusion and thermosyphon …

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A Closed-Loop Renewable Energy Evaluation Framework, Tony Kealy Jan 2020

A Closed-Loop Renewable Energy Evaluation Framework, Tony Kealy

Articles

Many businesses that have embraced renewable energy projects as part of their corporate sustainability efforts lack direction concerning how the projects are assessed. This study presents a framework that prescribes the necessary stages that allow a robust project evaluation to take place. The framework should assist practitioners in ascertaining if renewable energy projects, such as wind turbines and hydroelectric generators, contribute to energy cost savings and a reduction in CO2 emissions. The conceptual framework was developed using empirical data accessed from an 850-kW wind turbine case study and a 40-kW hydro-electric case study and embraced the action research methodology. Both …

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Performance Investigation Of Peak Shrinking And Interpolating The Papr Reduction Technique For Lte-Advance And 5g Signals, Somayeh Mohammady, Ronan Farrell, David Malone, John Dooley Jan 2020

Performance Investigation Of Peak Shrinking And Interpolating The Papr Reduction Technique For Lte-Advance And 5g Signals, Somayeh Mohammady, Ronan Farrell, David Malone, John Dooley

Articles

Orthogonal frequency division multiplexing (OFDM) has become an indispensable part of waveform generation in wideband digital communication since its first appearance in digital audio broadcasting (DAB) in Europe in 1980s, and it is indeed in use. As has been seen, the OFDM based waveforms work well with time division duplex operation in new radio (NR) systems in 5G systems, supporting delay-sensitive applications, high spectral efficiency, massive multiple input multiple output (MIMO) compatibility, and ever-larger bandwidth signals, which has demonstrated successful commercial implementation for 5G downlinks and uplinks up to 256-QAM modulation schemes. However, the OFDM waveforms suffer from high peak …

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Self-Similar Pcosecond Pulse Compression For Supercontinuum Generation At Mid-Infrared Wavelength In Silicon Strip Waveguides, Yujun Cheng, Jinhui Yuan, Chao Mei, Feng Li, Zhe Kang, Binbin Yan, Xian Zhou, Qiang Wu, Kuiru Wang, Xinzhu Sang, Keping Long, Chongxiu Yu, Gerald Farrell Jan 2020

Self-Similar Pcosecond Pulse Compression For Supercontinuum Generation At Mid-Infrared Wavelength In Silicon Strip Waveguides, Yujun Cheng, Jinhui Yuan, Chao Mei, Feng Li, Zhe Kang, Binbin Yan, Xian Zhou, Qiang Wu, Kuiru Wang, Xinzhu Sang, Keping Long, Chongxiu Yu, Gerald Farrell

Articles

Self-similar pulse compression has important application in highly coherent supercontinuum (SC) generation. In this paper, we numerically present the mid-infrared self-similar picosecond pulse compression in a tapered suspended silicon strip waveguide, which is designed with exponentially decreasing dispersion profile along the direction of propagation. When the variation of the Kerr nonlinear coefficient ��(z), linear and nonlinear losses, higher-order nonlinearity, and higher-order dispersion are taken into consideration, the simulation result shows that a 1 ps input pulse centered at wavelength 2.8 μm could be self-similarly compressed to 47.06 fs in a 3.9-cm waveguide taper, along with a compression factor ��c of …

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Cognitive Performance In Midlife Type 2 Diabetes: Results Form The Enbind Study, A. H. Dyer, L. Mckenna, G. Gamage, N. M. Bourke, Isabelle Killane, M. Widdowson, C. P. Woods, J. Gibney, R. Reilly, D. O'Neill, S. P. Kennelly Jan 2020

Cognitive Performance In Midlife Type 2 Diabetes: Results Form The Enbind Study, A. H. Dyer, L. Mckenna, G. Gamage, N. M. Bourke, Isabelle Killane, M. Widdowson, C. P. Woods, J. Gibney, R. Reilly, D. O'Neill, S. P. Kennelly

Articles

Aims: To establish the impact of uncomplicated type 2 diabetes on cognitive and neuropsychological performance in midlife. Methods: We performed a cross-sectional study of middle-aged adults with uncomplicated type 2 diabetes and a cohort of healthy control participants. General cognition was assessed using the Montreal Cognitive Assessment test and neuropsychological assessment was undertaken using a detailed neuropsychological assessment battery. Results: A total of 152 participants (102 with type 2 diabetes and 50 controls) were recruited (mean age 52 ± 8 years, 51% women). Participants with midlife type 2 diabetes were more than twice as likely to make an error on …

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Crystal-Field Engineering Of Ultrabroadband Mid-Infrared Emission In Co2+-Doped Nano-Chalcogenide Glass Composites, Xiasong Lu, Runan Zhang, Yindong Zhang, Shaoqian Zhang, Jing Ren, Lukas Strizik, Thomas Wagner, Gerald Farrell, Pengfei Wang Jan 2020

Crystal-Field Engineering Of Ultrabroadband Mid-Infrared Emission In Co2+-Doped Nano-Chalcogenide Glass Composites, Xiasong Lu, Runan Zhang, Yindong Zhang, Shaoqian Zhang, Jing Ren, Lukas Strizik, Thomas Wagner, Gerald Farrell, Pengfei Wang

Articles

unable and ultrabroadband mid-infrared (MIR) emissions in the range of 2.5–4.5 μm are firstly reported from Co2+-doped nano-chalcogenide (ChG) glass composites. The composites embedded with a variety of binary (ZnS, CdS, ZnSe) and ternary (ZnCdS, ZnSSe) ChG nanocrystals (NCs) can be readily obtained by a simple one-step thermal annealing method. They are highly transparent in the near- and mid-infrared wavelength region. Low-cost and commercially available Er3+-doped fiber lasers can be used as the excitation source. By crystal-field engineering of the embedded NCs through cation- or anion-substitution, the emission properties of Co2+ including its emission peak wavelength and bandwidth can be …

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Applications Of Artificial Intelligence To Cryptography, Jonathan Blackledge, Napo Mosola Jan 2020

Applications Of Artificial Intelligence To Cryptography, Jonathan Blackledge, Napo Mosola

Articles

This paper considers some recent advances in the field of Cryptography using Artificial Intelligence (AI). It specifically considers the applications of Machine Learning (ML) and Evolutionary Computing (EC) to analyze and encrypt data. A short overview is given on Artificial Neural Networks (ANNs) and the principles of Deep Learning using Deep ANNs. In this context, the paper considers: (i) the implementation of EC and ANNs for generating unique and unclonable ciphers; (ii) ML strategies for detecting the genuine randomness (or otherwise) of finite binary strings for applications in Cryptanalysis. The aim of the paper is to provide an overview on …

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Reformulating The Binary Masking Approach Of Adress As Soft Masking, Ruairí De Fréin Jan 2020

Reformulating The Binary Masking Approach Of Adress As Soft Masking, Ruairí De Fréin

Articles

Binary masking forms the basis for a number of source separation approaches that havebeen successfully applied to the problem of de-mixing music sources from a stereo recording.A well-known problem with binary masking is that, when music sources overlap in the time-frequencydomain, only one of the overlapping sources can be assigned the energy in a particulartime-frequency bin. To overcome this problem, we reformulate the classical pan-pot source separationproblem for music sources as a non-negative quadratic program. This reformulation gives rise toan algorithm, called Redress, which extends the popular Adress algorithm. It works by definingan azimuth trajectory for each source based on …

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Optimal Sizing Of Energy Storage With Embedded Wind Power Generation, Nicholas Roche, Jane Courtney Jan 2020

Optimal Sizing Of Energy Storage With Embedded Wind Power Generation, Nicholas Roche, Jane Courtney

Articles

Energy storage technologies are key to increased penetration of renewable energies on the distribution system. Not only do they increase availability of energy, but they contribute to the overall reliability of the system. However, the cost of large-scale storage systems can often be prohibitive, and storage needs to be sized appropriately, both to fill the energy gaps inevitable in renewable energies such as wind and to minimize costs. In this work, a Monte Carlo Simulation is performed to optimally size an energy storage system while minimizing overall system cost. 30 years of historical wind speed data are used to model …

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Impact Assessment Of High-Power Domestic Ev Charging Proliferation Of A Distribution Network, Arsalan Zaidi, Keith Sunderland, Michael Conlon Jan 2020

Impact Assessment Of High-Power Domestic Ev Charging Proliferation Of A Distribution Network, Arsalan Zaidi, Keith Sunderland, Michael Conlon

Articles

Transport electrification is becoming the mainstream as a means to improve efficiency, performance, andsustainability of transportation systems. Electrical vehicles (EVs) can help to de-carbonise the environment, but a downside isthe technical issues presented to the low-voltage distribution network. To quantify the stochastic nature of transport-affectedelectrification, probabilistic load flow is employed. Monte Carlo-based simulation is applied to accommodate the probabilisticuncertainties associated with variable EV charging patterns. This study considers high-power charging (up to 11 kW) at thedomestic level while monitoring power quality variations (voltage drop, voltage unbalance factor, voltage sag) standards. Thiswork focuses on the Irish and UK, distribution system operator's–transmission …

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A Wide Frequency Scanning Printed Bruce Array Antenna With Bowtie And Semi-Circular Elements, Zeeshan Ahmed, Patrick Mcevoy, Max Ammann Jan 2020

A Wide Frequency Scanning Printed Bruce Array Antenna With Bowtie And Semi-Circular Elements, Zeeshan Ahmed, Patrick Mcevoy, Max Ammann

Articles

A printed edge-fed counterpart of the wire Bruce array antenna, for frequency scanning applications, is presented in this paper. The unit-cell of the proposed antenna consists of bowtie and semi-circular elements to achieve wide bandwidth from below 22 GHz to above 38 GHz with open-stopband suppression. The open-stopband suppression enables a wide seamless scanning range from backward, through broadside, to forward endfire. A sidelobe threshold level of −10 dB is maintained to evaluate efficient scanning performance of the antenna. The antenna peak realized gain is 15.30 dBi, and, due to its compact size, has the ability to scan from −64° …

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Anti-Resonance, Inhibited Coupling And Mode Transitionin Depressed Core Fibers, Xiaokang Lian, Gerald Farrell, Qiang Wu, Wei Han, Changyu Shen, Youqiao Ma, Yuliya Semenova Jan 2020

Anti-Resonance, Inhibited Coupling And Mode Transitionin Depressed Core Fibers, Xiaokang Lian, Gerald Farrell, Qiang Wu, Wei Han, Changyu Shen, Youqiao Ma, Yuliya Semenova

Articles

The depressed core fiber (DCF), consisting of a low-index solid core, a high-index cladding and air surrounding, is in effect a bridge between the conventional step-index fiber and the tube-type hollow-core fiber from the point of view of the index profile. In this paper the dispersion diagram of a DCF is obtained by solving the full-vector eigenvalue equations and analyzed using the theory of anti-resonant and the inhibited coupling mechanisms. While light propagation in tube-type hollow-core fibers is commonly described by the symmetric planar waveguide model, here we propose an asymmetric planar waveguide for the DCFs in an anti-resonant reflecting …

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Investigation On The Polarization Dependence Of An Angled Polished Multimode Fibre Structure, Ruoning Wang, Ke Tian, Meng Zhang, Yuxuan Jiang, Libo Yuan, Guoyong Jin, Gerald Farrell, Elfed Lewis, Pengfei Wang Jan 2020

Investigation On The Polarization Dependence Of An Angled Polished Multimode Fibre Structure, Ruoning Wang, Ke Tian, Meng Zhang, Yuxuan Jiang, Libo Yuan, Guoyong Jin, Gerald Farrell, Elfed Lewis, Pengfei Wang

Articles

An angled polished multimode (APM) fibre structure is described for the first time, to the best our knowledge, and its polarization dependence is investigated theoretically and experimentally. Two angled planes are established in the multimode fibre (MMF) section of a single-mode-multimode-single-mode (SMS) fibre structure using the fibre side-polishing technique, forming the APM fibre structure. This designed circular asymmetric geometry induces different propagation characteristics for the TE and TM modes within the MMF. Simulated and experimental results both show that this difference is enhanced as the polishing angle increases, and a maximum extinction ratio (ER) of the spectrum of 13 dB …

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Spectral Dependence Of Transmission Losses In High-Index Polymer Coated No-Core Fibers, Xiaokang Lian, Gerald Farrell, Qiang Wu, Wei Han, Changyu Shen, Youqiao Ma, Yuliya Semenova Jan 2020

Spectral Dependence Of Transmission Losses In High-Index Polymer Coated No-Core Fibers, Xiaokang Lian, Gerald Farrell, Qiang Wu, Wei Han, Changyu Shen, Youqiao Ma, Yuliya Semenova

Articles

A high-index polymer coated no-core fiber (PC-NCF) is effectively a depressed core fiber, where the light is guided by the anti-resonant, inhibited coupling and total internal reflection effects and the dispersion diagram shows periodic resonant and anti-resonant bands. In this paper, the transmission spectra of the straight and bent PC-NCFs (length > 5 cm) are measured and analyzed from a modal dispersion perspective. For the purpose of the study, the PC-NCFs are contained within a fiber hetero-structure using two single-mode fiber (SMF) pigtails forming a SMF-PC-NCF-SMF structure. The anti-resonance spectral characteristics are suppressed by the multimode interference in the PC-NCF with …

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Indirect Sliding Mode Control For Dc-Dc Sepic Converters, Hasan Komurcugil, Samet Biricik, Naki Guler Jan 2020

Indirect Sliding Mode Control For Dc-Dc Sepic Converters, Hasan Komurcugil, Samet Biricik, Naki Guler

Articles

This article presents an indirect sliding mode control (SMC) for single-ended primary-inductor converters (SEPIC). Unlike the conventional SMC methods, the proposed SMC method employs a sliding surface function based on the input current error only. The use of such sliding surface function not only simplifies the implementation but also reduces the cost of implementation. It is shown that the output voltage control can be achieved indirectly. The input current reference is generated by a proportional-integral (PI) regulator. The existence condition and the region of the closed-loop system are determined for all possibilities of the PI gains. The performance of the …

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Carbon-Based Interlayers In Perovskite Solar Cells, Aleksandr P. Litvin, Xiaoyu Zhang, Kevin Berwick, Anatoly V. Fedorov, Weitao Zheng, Alexander V. Baranov Jan 2020

Carbon-Based Interlayers In Perovskite Solar Cells, Aleksandr P. Litvin, Xiaoyu Zhang, Kevin Berwick, Anatoly V. Fedorov, Weitao Zheng, Alexander V. Baranov

Articles

Perovskites are solution-processed, high-performance semiconductors of interest in low-cost photovoltaics. The interfaces between the perovskite photoactive layers and the top and bottom contacts are crucial for efficient charge transport and minimizing trapping. Control of the collection of charge carriers at these interfaces is decisive to device performance. Here, we review recent progress in the realization of efficient perovskite solar cells using cheap, easily processed, stable, carbon-based interlayers. Interface materials including graphene, carbon nanotubes, fullerenes, graphene quantum dots and carbon dots are introduced and their influence on device performance is discussed.

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Classification And Biological Identity Of Complex Nano Shapes, Luca Boselli, Hender Lopez, Wei Zhang, Qi Cai, Valeria A. Giannone, Jingji Li, Alirio Moura, João M. De Araujo, Jennifer Cookman, Valentina Castagnola, Yan Yan, Kenneth A. Dawson Jan 2020

Classification And Biological Identity Of Complex Nano Shapes, Luca Boselli, Hender Lopez, Wei Zhang, Qi Cai, Valeria A. Giannone, Jingji Li, Alirio Moura, João M. De Araujo, Jennifer Cookman, Valentina Castagnola, Yan Yan, Kenneth A. Dawson

Articles

Everywhere in our surroundings we increasingly come in contact with nanostructures that have distinctive complex shape features on a scale comparable to the particle itself. Such shape ensembles can be made by modern nano-synthetic methods and many industrial processes. With the ever growing universe of nanoscale shapes, names such as “nanoflowers” and “nanostars” no longer precisely describe or characterise the distinct nature of the particles. Here we capture and digitise particle shape information on the relevant size scale and create a condensed representation in which the essential shape features can be captured, recognized and correlated. We find the natural emergence …

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The Missing Parameter In Renewable Energy Power Quality Analysis, I.E. The Coefficient Of Variation: Case Study Of A 3-Mw On-Site Wind Turbine Project In Ireland, Tony Kealy Jan 2020

The Missing Parameter In Renewable Energy Power Quality Analysis, I.E. The Coefficient Of Variation: Case Study Of A 3-Mw On-Site Wind Turbine Project In Ireland, Tony Kealy

Articles

Businesses are employing distributed generation techniques, such as wind turbines, to decarbonise their electrical energy supply by reducing their dependence on fossil-fuel-generated energy. This study investigates the effectiveness of a company making a €3,500,000 investment in a 3-MW on-site wind turbine to supply some or all of their factory electrical loads. The results should benefit the investing company and other potential investors by evaluating the economic, environmental, and social outcomes of the investment. A case study methodology was used. The study found that the payback period was six and a half years, and the turbine installation benefited the environment by …

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How To Achieve Efficiency And Accuracy In Discrete Element Simulation Of Asphalt Mixture: A Drf-Based Equivalent Model For Asphalt Sand Mortar, Yu Liu, Peifeng Su, Miaomiao Li, Hui Yao, Junfu Liu, Mei Xu, Xiaodong Zhou, Zhanping You Jan 2020

How To Achieve Efficiency And Accuracy In Discrete Element Simulation Of Asphalt Mixture: A Drf-Based Equivalent Model For Asphalt Sand Mortar, Yu Liu, Peifeng Su, Miaomiao Li, Hui Yao, Junfu Liu, Mei Xu, Xiaodong Zhou, Zhanping You

Michigan Tech Publications, Part 1

The clump-based discrete element model is one of the asphalt mixture simulation methods, which has the potential to not only predict mixture performance but also simulate particle movement during compaction, transporting, and other situations. However, modelling of asphalt sand mortar in this method remains to be a problem due to computing capacity. Larger-sized balls (generally 2.0-2.36 mm) were usually used to model the smaller particles and asphalt binder, but this replacement may result in the mixture's unrealistic volumetric features. More specifically, replacing original elements with equal volume but larger size particles will increase in buck volume and then different particle …

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Reversible And Irreversible Adsorption Of Bare And Hybrid Silica Nanoparticles Onto Carbonate Surface At Reservoir Condition, Zain-Ul-Abedin Arain, Sarmad Al-Anssari, Muhammad Ali, Shoaib Memon, Masood Ahmed Bhatti, Christopher Lagat, Mohammad Sarmadivaleh Jan 2020

Reversible And Irreversible Adsorption Of Bare And Hybrid Silica Nanoparticles Onto Carbonate Surface At Reservoir Condition, Zain-Ul-Abedin Arain, Sarmad Al-Anssari, Muhammad Ali, Shoaib Memon, Masood Ahmed Bhatti, Christopher Lagat, Mohammad Sarmadivaleh

Research outputs 2014 to 2021

© 2020 Southwest Petroleum University Realistic implementation of nanofluids in subsurface projects including carbon geosequestration and enhanced oil recovery requires full understanding of nanoparticles (NPs) adsorption behaviour in the porous media. The physicochemical interactions between NPs and between the NP and the porous media grain surface control the adsorption behavior of NPs. This study investigates the reversible and irreversible adsorption of silica NPs onto oil-wet and water-wet carbonate surfaces at reservoir conditions. Each carbonate sample was treated with different concentrations of silica nanofluid to investigate NP adsorption in terms of nanoparticles initial size and hydrophobicity at different temperatures, and pressures. …

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Comparative Study Of Green And Synthetic Polymers For Enhanced Oil Recovery, Nasiru Salahu Muhammed, Md. Bashirul Haq, Dhafer Al-Shehri, Mohammad Mizanur Rahaman, Alireza Keshavarz, S. M. Zakir Hossain Jan 2020

Comparative Study Of Green And Synthetic Polymers For Enhanced Oil Recovery, Nasiru Salahu Muhammed, Md. Bashirul Haq, Dhafer Al-Shehri, Mohammad Mizanur Rahaman, Alireza Keshavarz, S. M. Zakir Hossain

Research outputs 2014 to 2021

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Several publications by authors in the field of petrochemical engineering have examined the use of chemically enhanced oil recovery (CEOR) technology, with a specific interest in polymer flooding. Most observations thus far in this field have been based on the application of certain chemicals and/or physical properties within this technique regarding the production of 50–60% trapped (residual) oil in a reservoir. However, there is limited information within the literature about the combined effects of this process on whole properties (physical and chemical). Accordingly, in this work, we present a clear distinction …

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A Sample Weight And Adaboost Cnn-Based Coarse To Fine Classification Of Fruit And Vegetables At A Supermarket Self-Checkout, Khurram Hameed, Douglas Chai, Alexander Rassau Jan 2020

A Sample Weight And Adaboost Cnn-Based Coarse To Fine Classification Of Fruit And Vegetables At A Supermarket Self-Checkout, Khurram Hameed, Douglas Chai, Alexander Rassau

Research outputs 2014 to 2021

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. The physical features of fruit and vegetables make the task of vision-based classification of fruit and vegetables challenging. The classification of fruit and vegetables at a supermarket self-checkout poses even more challenges due to variable lighting conditions and human factors arising from customer interactions with the system along with the challenges associated with the colour, texture, shape, and size of a fruit or vegetable. Considering this complex application, we have proposed a progressive coarse to fine classification technique to classify fruit and vegetables at supermarket checkouts. The image and weight of …

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Simulating Der Adoption In Wholesale Power Markets Using Agent Based Computational Economics, Islam H. El-Adaway, Charles Sims, Mohamed Eid, Yinan Liu, Gasser Galal Ali Jan 2020

Simulating Der Adoption In Wholesale Power Markets Using Agent Based Computational Economics, Islam H. El-Adaway, Charles Sims, Mohamed Eid, Yinan Liu, Gasser Galal Ali

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

There is a transition from centralized electricity generation to distributed energy resources (DER). An increasing number of customers are adopting distributed solar generation (DSG). However, utilities face the difficulty of predicting electrical demand and therefore dispatching and controlling generation. The goal of this research is to study the evolving dynamic market behavior affected by DER investment decisions. To that end, agent-based modeling (ABM) is used to study the emerging behavior of the market under those conditions. The model is developed from the existing and validated AMES framework, which is used for agent-based computational economics (ACE) simulation of wholesale power markets. …

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Analysis Of Antenna Designs For The Maximum Power Transmission, Lauryn P. Smith Jan 2020

Analysis Of Antenna Designs For The Maximum Power Transmission, Lauryn P. Smith

College of Graduate Studies: Theses & Dissertations

Since Nikola Tesla discovered wireless power transmission, it has become a very interesting topic of study in the antennas and wireless propagation community. Various aspects and applications for wireless power transmission are studied today, a few of which are investigated in this work. First, various antenna geometries are analyzed for radiative near-field wireless power transfer in terms of electrical field strength. It is determined that the meander antenna is ideal for maximum power transfer in its radiative near-field region, contrary to its far-field behavior. Next, in the application of radio frequency identification, a directive, UHF RFID tag antenna is designed …

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A Numerical And Experimental Study On Effect Of Composition Of Ar-N2 Shielding Gas On The Weld Bead Profile And Its Prediction For Hot Wire Arc Additive Manufacturing, Niraj Pudasaini Jan 2020

A Numerical And Experimental Study On Effect Of Composition Of Ar-N2 Shielding Gas On The Weld Bead Profile And Its Prediction For Hot Wire Arc Additive Manufacturing, Niraj Pudasaini

College of Graduate Studies: Theses & Dissertations

Wire arc additive manufacturing is a process of making three-dimensional metal parts in a layer-by-layer approach using a feed wire and electric arc as a heat source. Wire arc additive manufacturing (WAAM) is becoming more popular due to its ability to create complex 3D parts, less build time, high deposition rate, and significant cost savings. Out of the many parameters used in WAAM, one of the important parameters is shielding gas which plays a significant role in material quality, properties, and defects. In this study, a controlled amount of Argon (Ar) and Nitrogen (N2) shielding gases are used …

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Applying Artificial Intelligence To Medical Data, Shaikh Shiam Rahman Jan 2020

Applying Artificial Intelligence To Medical Data, Shaikh Shiam Rahman

College of Graduate Studies: Theses & Dissertations

Machine learning, data mining, and deep learning has become the methodology of choice for analyzing medical data and images. In this study, we implemented three different machine learning techniques to medical data and image analysis. Our first study was to implement different log base entropy for a decision tree algorithm. Our results suggested that using a higher log base for the dataset with mostly categorical attributes with three or more categories for each attribute can obtain a higher accuracy. For the second study, we analyzed mental health data tuning the parameters of the decision tree (splitting method, depth and entropy). …

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Rational Catalyst Design For N2 Reduction Under Ambient Conditions: Strategies Towards Enhanced Conversion Efficiency, Lei Shi, Yu Yin, Shaobin Wang, Hongqi Sun Jan 2020

Rational Catalyst Design For N2 Reduction Under Ambient Conditions: Strategies Towards Enhanced Conversion Efficiency, Lei Shi, Yu Yin, Shaobin Wang, Hongqi Sun

Research outputs 2014 to 2021

Ammonia (NH3), one of the basic chemicals in most fertilizers and a promising carbon-free energy storage carrier, is typically synthesized via the Haber–Bosch process with high energy consumption and massive emission of greenhouse gases. The photo/electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions has attracted increasing interests recently, providing alternative routes to realize green NH3 synthesis. Despite rapid advances achieved in this most attractive research field, the unsatisfactory conversion efficiency including a low NH3 yield rate, and limited Faradaic efficiency or apparent quantum efficiency still remains as a great challenge. The NRR performance is intrinsically related …

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Investigating The Factors Impacting The Success Of Immiscible Carbon Dioxide Injection In Unconventional Shale Reservoirs: An Experimental Study, Sherif M. Fakher Jan 2020

Investigating The Factors Impacting The Success Of Immiscible Carbon Dioxide Injection In Unconventional Shale Reservoirs: An Experimental Study, Sherif M. Fakher

Doctoral Dissertations

"Unconventional shale reservoirs are currently gaining significant interest due to the huge hydrocarbon volumes that they bear. Enhanced oil recovery (EOR) techniques have been suggested to increase recovery from shale reservoirs. One of the most promising EOR methods is gas EOR (GEOR), most notably carbon dioxide (CO2). Not only can CO2 increase oil recovery by interacting with the oil and the shale, but it has also been shown to adsorb to the shale rock and thus is effective in both EOR applications and also carbon storage purposes. This research aims to experimentally investigate several of the interactions …

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Development Of Radiation Transport Techniques For Modelling A High-Resolution Multi-Energy Photon Emission Tomography System, Seth Kilby Jan 2020

Development Of Radiation Transport Techniques For Modelling A High-Resolution Multi-Energy Photon Emission Tomography System, Seth Kilby

Doctoral Dissertations

”Nondestructive characterization techniques such as gamma tomography represent powerful tools for the analysis and quantification of physical defects and radionuclide concentrations within nuclear fuel forms. Gamma emission tomography, in particular, has the ability to utilize the inherent radiation within spent nuclear fuel to provide users with information about the migration and concentration of fission and activation products within the fuel form. Idaho National Laboratory is interested in using this technology to analyze new nuclear fuel forms for potential use in next generation nuclear reactors. In this work, two aspect of the system are analyzed. The first is a semi-analytic radiation …

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