Engineering Commons^™

An Equivalent Circuit For Corona Discharges Caused By A Point To Plane Arrangement At Ac, Dc And Combined Voltages, Tobias Dezenzo, Thomas Betz, Andreas Schwarzbacher

Conference papers

In this paper a new two stage equivalent circuit for corona discharges is introduced. Its aim is to fill the gap between complexity of the circuit and accurate representation of the physical properties, which underlay a corona discharge. The first stage represents the voltage distribution and the occurrence of a discharge with respect to the applied voltage. The second stage models the physical discharge behavior like ionization, number of electrons, positive and negative ions as well as their interaction. The proposed circuit is able to model the different modes of corona discharges, which is experimentally verified. The simulation results are …

A Hardware One-Time Pad Prototype Generator For Localising Cloud Security, Jonathan Blackledge, Paul Tobin, Lee Tobin, Mick Mckeever

Conference papers

Abstract: In this paper, we examine a system for encrypting data before storing in the Cloud. Adopting this system gives excellent security to stored data and complete control for accessing data by the client at different locations. The motivation for developing this personal encryption came about because of poor Cloud security and doubts over the safety of public encryption algorithms which might contain backdoors. However, side-channel attacks and other unwanted third-party interventions in Cloud security, probably contribute more to the poor security record history. These factors led to the development of a prototype for personalising security locally which defeats cryptanalysis. …

Simultaneous Measurement Of Both Magnetic Field Strength And Temperature With A Microfiber Coupler Based Fiber Laser Sensor, Fangfang Wei, Dejun Liu, Yuliya Semenova, Gerald Farrell, Arun Mallik

Conference papers

In this paper we propose and investigate a novel magnetic field sensor based of a ring erbium-doped fiber laser combined with a fiber Bragg grating and a Sagnac loop containing a microfiber coupler and magnetic fluid. In addition to the magnetic field sensing capability, the proposed structure can simultaneously provide temperature information. Thanks to the dual-ring structure of the MFC-Sagnac loop and the FBG-assisted resonant cavity, the output has two distinct laser peaks. Experimentally demonstrated magnetic field sensitivity of one of the laser peaks is 15 pm/mT in the magnetic field range from 0 to 100 mT. The spectral position …

Investigation Of Electrical Defects Arising From Excessive Sidewall Force And Excessive Tensile Strain On Power Cables, Darren Mcconnon, Joseph Kearney, Tom Looby, James O'Shaughnessy

Conference papers

The study includes a comprehensive review of the existing literature and guidelines regarding the effects of sidewall force and tensile strain on power cables during installation. The most appropriate diagnostic test methods required to analyse these effects are also assessed. The results of tests and analysis of the existing literature are then combined in an attempt to determine a realistic basis for guidelines and recommendations relevant to cable installation forces.

A Review Of Control Methodologies For Dynamic Glazing, Eoin D. Mclean, Brian Norton, Derek Kearney, Philippe Lemarchand

Conference papers

With adaptive building façade technologies, a building envelope can provide a comfortable indoor environment under varying external conditions with minimal additional heating or cooling. The control strategy applied to the adaptation of the façade is a key determining factor in the successful integration of these technologies into a building. The building envelope plays a key role in regulating light, heat and mass transfer from the outdoor environment to the indoor. Dynamic glazing can be used to adjust the amount of solar radiation entering a building. The control strategies that ultimately determine the success of these switchable technologies to affect a …

Switchable Windows - Spectral Transmission And Switching Times, Philippe Lemarchand, Eoin D. Mclean, Brian Norton

Conference papers

The switching time and spectral transmission in fully clear and fully opaque states of polymer dispersed liquid crystals (PDLC), suspended particle device (SPD) and electrochromic (EC) switchable windows were evaluated to assess their suitability to control solar heat transmission though glazed façade and comfort to building occupants. The transmission measurement on a SPD film showed a very effective absorption modulation in the visible range but fast decrease in the near infrared region. The switching speed was demonstrated to be related strongly to wavelengths. A SPD film with a larger absorption and faster switching speed in the infrared region was shown …

Design Of An Underwater Cable Fault Location Device To Precisely Locate Submarine Cable Faults, Glenn O'Reilly, Joseph Kearney, John Lawler, Tom Looby

Conference papers

The objective of the paper is to develop a robust and reliable method to pinpoint submarine cable faults. Submarine cables have existed for over 100 years but there is still no single method used to determine the precise location of a submarine cable fault. The various methods used to pinpoint cable faults, both submarine and non-submarine were researched and investigated to produce a method which would accurately pinpoint submarine cable faults. From this, the idea of a hydrophone string was derived from a non-submarine pinpointing method currently used. The hydrophone string was tested and it accurately pinpointed the location of …

A Fast Linear Electro-Optical Effect In A Non-Chiral Bent-Core Liquid Crystal, Yuri Panarin, S.P. Sreenilayam, J.K. Vij, A. Lehmann, C. Tschierske

Articles

We report the observation of an electro-optical effect for a linear rotation of the optical axis as function of the electric field in an achiral tilted bent-core liquid crystalline compound, in which 4-cyanoresorcinol bisbenzoate core is symmetrically terminated by long linear alkyl chains (n =16) on both ends. The linear electro-optic effect observed in this material is similar to the deformed helical ferroelectric liquid crystal (DHFLC) effect reported previously in a FLC material except that dimensions of the helical pitch differ by two orders of magnitude. In the chiral systems, the helical pitch usually lies on the scale of sub-optical …

Assessment Of Mental Workload: A Comparison Of Machine Learning Methods And Subjective Assessment Techniques, Karim Moustafa, Saturnino Luz, Luca Longo

Articles

Mental workload (MWL) measurement is a complex multidisciplinary research field. In the last 50 years of research endeavour, MWL measurement has mainly produced theory-driven models. Some of the reasons for justifying this trend includes the omnipresent uncertainty about how to define the construct of MWL and the limited use of datadriven research methodologies. This work presents novel research focused on the investigation of the capability of a selection of supervised Machine Learning (ML) classification techniques to produce data-driven computational models of MWL for the prediction of objective performance. These are then compared to two state-of-the-art subjective techniques for the assessment …

Assessing Peer Review By Gauging The Fate Of Rejected Manuscripts: The Case Of The Journal Of Artificial Societies And Social Simulation, Niccolò Casnici, Francisco Grimaldo, Nigel Gilbert, Pierpaolo Dondio, Flaminio Squazzoni

Articles

This paper investigates the fate of manuscripts that were rejected from JASSS-The Journal of Artificial Societies and Social Simulation, the flagship journal of social simulation. We tracked 456 manuscripts that were rejected from 1997 to 2011 and traced their subsequent publication as journal articles, conference papers or working papers. We compared the impact factor of the publishing journal and the citations of those manuscripts that were eventually published against the yearly impact factor of JASSS and the number of citations achieved by the JASSS mean and top cited articles. Only 10% of the rejected manuscripts were eventually published in a …

Benchmarking Javascript Frameworks, Carl Lawrence Mariano

Dissertations

JavaScript programming language has been in existence for many years already and is one of the most widely known, if not, the most used front-end programming language in web development. However, JavaScript is still evolving and with the emergence of JavaScript Frameworks (JSF), there has been a major change in how developers develop software nowadays. Developers these days often use more than one framework in order to fulfil their job which has given rise to the problem for developers when it comes to choosing the right JavaScript framework to develop software which is partly due to the availability of countless …

Critical Comparison Of The Classification Ability Of Deep Convolutional Neural Network Frameworks With Support Vector Machine Techniques In The Image Classification Process, Robert Kelly

Dissertations

Recently, a number of new image classification models have been developed to diversify the number of options available to prospective machine learning classifiers, such as Deep Learning. This is particularly important in the field of medical image classification as a misdiagnosis could have a severe impact on the patient. However, an assessment on the level to which a deep learning based Convolutional Neural Network can outperform a Support Vector Machine has not been discussed. In this project, the use of CNN and SVM classifiers is used on a dataset of approx. 55,000 images. This dataset was used to assess the …

An Exploration Study Of Using The Universities Performance And Enrolments Features For Predicting The International Quality, Aeshah Althagafi

Dissertations

Quality ranking systems are crucial in the assessment of the academic performance of an institution because these assessment systems give details about how different learning institutions deliver their services. Education quality is also of paramount importance to the students because it is through quality education that these students develop skills that are needed in the job market. Besides, education enhances a student's academic and reasoning capacities. When universities are subjected to ranking systems, they are likely to improve their quality to be ranked high in the system. When the university administrators are exposed to ranking, competition gears up. Through competition, …

Exploring The Factors That Affect Secondary Student’S Mathematics And Portuguese Performance In Portugal, Lulu Cheng

Dissertations

Secondary education provides not only knowledge and skills, but also inculcates values, training of instincts, fostering right attitude and habits to enable adolescents to move into tertiary education or to ensure a workplace for students who decided to terminate their secondary schooling. Without secondary education to guide the development of young people through their adolescence, they will be ill prepared for tertiary education or for workplace, moreover, the possibility of juvenile delinquency and teenage pregnancy becomes higher. These negative effects will increase the pressures and expenditures on society and socio-economic. In 2006, Portugal was reported having the higher school-leaving rate …

The Influence Of Sensor-Based Intelligent Traffic Light Control On Traffic Flow In Dublin, Katja Rademacher

Dissertations

With growing cities and the increased use of vehicles for transportation purposes, there is a demand to make the traffic management in cities smarter. An intelligent traffic light control that dynamically adapts to the existing traffic conditions can help reduce traffic congestion and CO2 emissions. This thesis reviews the popular traffic light control approaches - static, actuated and adaptive – based on their influences on recorded traffic conditions in Dublin. The Irish capital relies heavily on busses for public transport adding to the number of already moving vehicles in the city centre. Using vehicle count data from inductive loop detectors …

Can Phishing Education Enable Users To Recognize Phishing Attacks?, Hanaa Alghamdi

Dissertations

Phishing attacks have increased rapidly and caused many drastic damages and losses for internet users‟ .The purpose of this research is to investigate on effectiveness of phishing education and training to help users identify different forms of phishing threats. The study has been conducted through developing a phishing quiz mobile application which includes four kinds of phishing threats. It tested the ability of users to recognize spoofed emails, SMS phishing (SMshing), scam phone calls (Vishing), and phishing through social media networks. A comprehensive literature review was discussed to investigate on the research area, understand the research problem, support the proposed …

A Comparison Of Supervised Machine Learning Classification Techniques And Theory-Driven Approaches For The Prediction Of Subjective Mental Workload, Dmitrii Gmyzin

Dissertations

In the modern world of technological progress, systems and interfaces are becoming more and more complex. As a consequence, it is a crucial to design the human-computer interaction in the most optimal way to improve the user experience. The construct of Mental Workload is a valid metric that can be used for such a goal. Among the different ways of measuring Mental Workload, self-reporting procedures are the most adopted for their ease of use and application. This research is focused on the application of Machine Learning as an alternative to theory-driven approaches for Mental Workload measurement. In particular, the study …

Evaluating The Effectiveness Of The Gestalt Principles Of Perceptual Observation For Virtual Reality User Interface Design, William Macnamara

Dissertations

There is a lot of interest and excitement surrounding the areas of Virtual Reality and Head-Mounted Displays with the recent releases of devices such as the Oculus Rift, Sony PSVR and the HTC Vive. While much of the focus for these devices has been related to sectors of the entertainment industries, namely the cinema and video game industries, there are many more practical applications for these technologies, with potential benefits in educational, training/simulation, therapeutic and modelling/design software. Developing a set of reliable guidelines for Virtual Reality User Interface Design could play a crucial role in whether the medium successfully integrates …

Physical Human Activity Recognition Using Machine Learning Algorithms, Haritha Vellampalli

Dissertations

With the rise in ubiquitous computing, the desire to make everyday lives smarter and easier with technology is on the increase. Human activity recognition (HAR) is the outcome of a similar motive. HAR enables a wide range of pervasive computing applications by recognizing the activity performed by a user. In order to contribute to the multi facet applications that HAR is capable to offer, predicting the right activity is of utmost importance. Simplest of the issues as the use of incorrect data manipulation or utilizing a wrong algorithm to perform prediction can hinder the performance of a HAR system. This …

Towards Improving Visqol (Virtual Speech Quality Objective Listener) Using Machine Learning Techniques, Joseph Mcnally

Dissertations

Vast amounts of sound data are transmitted every second over digital networks. VoIP services and cellular networks transmit speech data in increasingly greater volumes. Objective sound quality models provide an essential function to measure the quality of this data in real-time. However, these models can suffer from a lack of accuracy with various degradations over networks. This research uses machine learning techniques to create one support vector regression and three neural network mapping models for use with ViSQOLAudio. Each of the mapping models (including ViSQOL and ViSQOLAudio) are tested against two separate speech datasets in order to comparatively study accuracy …

A Transfer Matrix Approach To Aid In The Design And Optimization Of Hybrid Advanced Passive Structures For Enhancing Photovoltaic Efficiency, James Walshe, Sarah Mccormack, Hind Ahmed, John Doran

Conference Papers

The addition of a luminescent down-shifting (LDS) layer directly onto a photovoltaic (PV) cell introduces additional loss mechanisms within the system. The combination of non-ideal photo-luminescent materials encapsulated within a limited range of viable host materials, with the increased reflection losses arising from the newly created interface represent losses which must be overcome for LDS to offer an enhancement to the underlying cells efficiency. Exploiting the interaction between the highly enhanced electric fields established close to a metal nanoparticles (MNP’s) surface is one route aimed at mitigating the poor optical properties of the luminophore-host combinations available. Alternative approaches, aimed at …

Development And Characterisation Of A Bath-Based Vertical Blackbody Cavity Calibration Source For The Range −30 °C To 150 °C, Sam Boles, Igor Pušnik, Dubhaltach Mac Lochlainn, David Fleming, Izabela Naydenova, Suzanne Martin

Articles

Industrial use of Radiation Thermometers (RTs) is becoming increasingly common due to the perceived advantages and wide market availability. Blackbody Cavity Radiation Sources (BCRSs) are typically used for calibration of these instruments, and these cavities are oriented horizontally in most cases. For BCRSs based in thermal baths, this necessitates the use of custom-built baths with side openings. This paper presents a unique design of vertical bath-based BCRS that may be immersed in conventional calibration baths without modifications to the baths. The method, results, and analysis of an international comparison comparing this vertical BCRS, standard horizontal BCRSs, and a previous iteration …

Hydraulic Conductivity Testing Of Cement-Bentonite Mixes For Use In Annular Well Seals, Amy Lynn Norval

Masters Theses

"Grout is the material used in the annulus of water supply and monitoring wells to prevent movement of water from adjacent formations or from the land surface into the well. Grout is critical for preventing cross-contamination of aquifers through a borehole when a single well penetrates multiple aquifers and for protecting aquifers from surface contamination. The composition and emplacement of grout is regulated in most states, with standard mixes of bentonite and cement being the most widely used types of grout. Despite widespread adoption of grout regulations, surprisingly little literature is available to describe the effectiveness of different grout mixtures. …

Developing Restoration Schemes For A Road Transportation Network In The Event Of A Disaster, Ebin Antony

Masters Theses

"Transportation systems such as rail, road, and waterways are key component of critical infrastructure systems, providing connectivity between other components to enable the production and distribution of goods and services. During large scale disasters such as earth quakes and floods, this connectivity is disrupted, restricting or completely halting the flow of goods and services. To ensure that the connectivity between the different modes of transportation are restored in an aftermath of these disruptions, the interdependence between them and the importance of individual elements to the overall connectivity have to be studied and formulated to develop a system-level restoration plan. This …

Nuclei Segmentation Of Histology Images Based On Deep Learning And Color Quantization And Analysis Of Real World Pill Images, Sudhir Sornapudi

Masters Theses

"Medical image analysis has paved a way for research in the field of medical and biological image analysis through the applications of image processing. This study has special emphasis on nuclei segmentation from digitized histology images and pill segmentation. Cervical cancer is one of the most common malignant cancers affecting women. This can be cured if detected early. Histology image feature analysis is required to classify the squamous epithelium into Normal, CIN1, CIN2 and CIN3 grades of cervical intraepithelial neoplasia (CIN). The nuclei in the epithelium region provide the majority of information regarding the severity of the cancer. Segmentation of …

Quantifying Ceramic Proppant Transport In Complex Fracture Networks, Vivekvardhan Reddy Kesireddy

Masters Theses

"Water fracs have become an essential part of unconventional reservoirs to create deeper fracture networks. Proppant transport in water fracs is challenging in terms of fluids ability to carry the proppant deeper into these fracture networks. This experimental study investigates the impact of the flow rates, fracture widths and complexity controlling the ability of proppant to flow into complex fracture networks. This research attempts to nullify the knowledge gap in understanding width heterogeneity in primary and secondary fractures. This study speaks for settling pattern and proppant transport through a slot flow model with a unique approach to understand stage wise …

Characterizing Groundwater Flow At Fort Leonard Wood Using Universal Cokriging With Trend Removal, Rachel Mae Uetrecht

Masters Theses

"Groundwater elevation interpolation is necessary for the prediction of groundwater flow direction and contaminant transport. Kriging is a geostatistical tool commonly used to interpolate groundwater elevation. Kriging requires a relatively large number of monitoring wells at the site of interest. The variogram model is a crucial element to the kriging equations. The variogram modelling process is an iterative procedure that is often very time consuming. This study presents a literature based approach that provides a point of departure for the variogram modelling process as well as other kriging parameters. A literature database is developed in order to provide insight and …

Evaluation Of Preformed Particle Gel As A Diverting Agent For Acidizing, Bo Wei

Masters Theses

"Preformed particle gels (PPGs) have been developed and successfully used to improve conformance in heterogeneous reservoirs. However, no research has been reported to show their potential diverting applications in acidizing because of their unknown performance in this process. This work targets on evaluating the potential of PPGs to be used as diverting agents and factors influencing the diverting performance.

The swelling properties of three types of PPGs (PPG #1, #2, and #3) were first studied in brine and acid, including the swelling kinetics and equilibrium, PPG strength, and deswelling performance. Effects of different brine concentration, acid concentration, and temperature were …

2d Vector Map And Database Design For Indoor Assisted Navigation, Luciano Caraciolo Albuquerque

Dissertations and Theses

In this paper we implemented a 2D Vector Map, map editor and Database design intended to provide an efficient way to convert cad files from indoor environments to a set of vectors representing hallways, doors, exits, elevators, and other entities embedded in a floor plan, and save them in a database for use by other applications, such as assisted navigation for blind people.

A graphical application as developed in C++ to allow the user to input a CAD DXF file, process the file to automatically obtain nodes and edges, and save the nodes and edges to a database for posterior …

Influence Of Fibroblasts On Metastatic Cancer Cell Drug Resistance In A 3d Microfluidic Cell Array, Elizabeth C. Benoy

Dissertations and Theses

Modeling an accurate depiction of the tumor microenvironment, (TME), is essential to observe the effect external factors might have on the tumor in vivo. In cancer therapy specifically, the outcomes of clinical treatments are heavily dependent on drug testing methods despite the cytotoxic effects these methods might have on the patient. Our lab has previously developed a three layered microfluidic cell array (3D μFCA) to reconstruct the relevantly spatial configuration of tumor and microvasculature found in vivo in order to develop a more efficient tool of high throughput drug discovery and screening. In this study, we optimized this device to …