Engineering Commons^™

Query From Examples: An Iterative, Data-Driven Approach To Query Construction, Hao Li, Chee-Yong Chan, David Maier

Computer Science Faculty Publications and Presentations

In this paper, we propose a new approach, called Query from Examples (QFE), to help non-expert database users construct SQL queries. Our approach, which is designed for users who might be unfamiliar with SQL, only requires that the user is able to determine whether a given output table is the result of his or her intended query on a given input database. To kick-start the construction of a target query Q, the user first provides a pair of inputs: a sample database D and an output table R which is the result of Q on D. As there will be …

Design Analysis Of A 12.5 Ghz Pll In 130 Nm Sige Bicmos Process, Kehan Zhu, Vishal Saxena, Xinyu Wu, Sakkarapani Balagopal

Electrical and Computer Engineering Faculty Publications and Presentations

A systematic design method is applied to study and analyze the loop stability and phase noise of a type-II 3^rd-order charge pump PLL. The designed PLL outputs at 12.5 GHz, which is intended to provide a clock for a silicon photonic transmitter prototype. The charge pump current and loop filter resistor are made tunable to cover process and temperature variations. The PLL is designed in a 130 nm SiGe BiCMOS process. The rms jitter of the studied PLL output is about 5 ps with a 97.7 MHz reference clock with 4.9 ps rms jitter from a 0.05 to …

Dynamics Of Silver Photo-Diffusion Into Ge-Chalcogenide Films: Time-Resolved Neutron Reflectometry, M. Ailavajhala, M. R. Latif, K. Wolf, M. Mitkova, M. W. A. Skoda

Electrical and Computer Engineering Faculty Publications and Presentations

Silver diffuses into an amorphous (a-) chalcogenide layer while visible light illuminates Ag/a-chalcogenide films and neutron reflectometry is a suitable technique probing time evolution of the depth profiles without damaging the sample by the probe beam itself. In this paper, we report the results of time-resolved neutron reflectivity measurements of a-Ge₄₀Se₆₀/Ag/ Si films taken while the films are exposed to visible light. From the measurements, we found enormous changes in the neutron reflectivity profile, including a loss of total reflection region, with continuous illumination even after forming one homogeneous layer, which occurred about 50 min after …

A Cmos Spiking Neuron For Dense Memristor-Synapse Connectivity For Brain-Inspired Computing, Xinyu Wu, Vishal Saxena, Kehan Zhu

Electrical and Computer Engineering Faculty Publications and Presentations

Neuromorphic systems that densely integrate CMOS spiking neurons and nano-scale memristor synapses open a new avenue of brain-inspired computing. Existing silicon neurons have molded neural biophysical dynamics but are incompatible with memristor synapses, or used extra training circuitry thus eliminating much of the density advantages gained by using memristors, or were energy inefficient. Here we describe a novel CMOS spiking leaky integrate-and-fire neuron circuit. Building on a reconfigurable architecture with a single opamp, the described neuron accommodates a large number of memristor synapses, and enables online spike timing dependent plasticity (STDP) learning with optimized power consumption. Simulation results of an …

A Comprehensive Design Approach For A Mzm Based Pam-4 Silicon Photonic Transmitter, Kehan Zhu, Vishal Saxena, Xinyu Wu

Electrical and Computer Engineering Faculty Publications and Presentations

A 4-level pulse amplitude modulation (PAM-4) silicon photonic transmitter targeting operation at 25 Gb/s is designed using an electrical-photonic co-design methodology. The prototype consists of an electrical circuit and a photonics circuit, which were designed in 130 nm IBM SiGe BiCMOS process and 130nm IME SOI CMOS process, respectively. Then the two parts will be interfaced via side-by-side wire bonding. The electrical die mainly includes a 12.5 GHz PLL, a full-rate 4- channel uncorrelated 2⁷ − 1 pseudo-random binary sequence (PRBS) generator and CML drivers. The photonics die is a 2-segment Mach-Zehnder modulator (MZM) silicon photonics device with thermal …

A New Equivalent Circuit Of A Salient-Pole Synchronous Machine And Its Phasor Interpretation, Said Ahmed-Zaid, Danyal Mohammadi, Ahmed M. A. Oteafy

Electrical and Computer Engineering Faculty Publications and Presentations

This paper examines a shortcoming of the classical phasor diagram of a salient-pole synchronous machine based on the well-established two-reaction theory. Unlike in the phasor diagram of a smooth-air-gap machine, it is not possible to readily identify the internally-developed electromagnetic power of a salient-pole synchronous machine from this phasor diagram. By defining new machine reactances, a single equivalent circuit of a salient-pole synchronous machine is proposed together with a phasor diagram where the internally-developed electromagnetic power is made apparent. The revised two-reaction theory is illustrated using the mathematical model of a two-phase salient-pole synchronous machine whose equations are manipulated using …

Measuring The Effects Of Pre-College Engineering Experiences, Year 2, Noah Salzman, Matthew W. Ohland, Monica E. Cardella

Electrical and Computer Engineering Faculty Publications and Presentations

The implementation of co-curricular and extracurricular pre-college engineering programs has expanded dramatically in recent years. Many states now include engineering as part of their education standards for both students and teachers, reflecting the increasing acceptance of engineering at the K-12 level and its potential value to students. In addition to promoting outcomes that benefit all students regardless of career aspirations such as increased math and science achievement and greater technological literacy, K-12 engineering programs have been identified as a means of recruiting and retaining potential students in engineering.

The growth of pre-college engineering programs means that increasing numbers of incoming …

Template Generation From Postmarks Using Cascaded Unsupervised Learning, Elisa H. Barney Smith, Gernot Fink

Electrical and Computer Engineering Faculty Publications and Presentations

Information in historical datasets comes in many forms. We are working with a set of World War I era postcards that contain hand written text, some preprinted text, postage stamps and postmark/cancellation stamps. The postmarks are of considerable interest to collectors looking for images of samples they had not previously seen. The postmarks also provide information on the originating location of the card that complements the information in the address block.

The postmarks vary considerably with towns and dates, but also styles. The styles can be grouped into categories. A method for automatically extracting templates for each category of these …

Almost Sure Asymptotic Stabilization Of Differential Equations With Time-Varying Delay By Lévy Noise, Dezhi Liu, Weiqun Wang, Jose Luis Menaldi

Mathematics Faculty Research Publications

This paper aims to determine that the Lévy noise can stabilize the given differential equations with time-varying delay, which has generalized the Brownian motion case. An analysis is developed and sufficient conditions on the stabilization for stochastic differential equations with time-varying delay are presented. Our stabilization criteria is in terms of linear matrix inequalities (LMIs), whence the feedback controls can be designed more easily in practice.

Elementary Teachers Committed To Actively Teaching Science And Engineering, Julianne Radkowski Opperman Phd

All Student Scholarship

Committed elementary teachers of science and engineering, members of a professional learning community called Collaborative Conversations in STEM, were studied to elicit their perceptions of experiences that influenced their commitment to, and their pedagogical content knowledge of, STEM teaching and learning.

Does Choice Of Programming Language Affect Student Understanding Of Programming Concepts In A First Year Engineering Course?, Benjamin D. Mcpheron, Stephanie M. Gratiano, William J. Palm

Engineering, Computing & Construction Management Faculty Publications

Most undergraduate engineering curricula include computer programming to some degree,introducing a structured language such as C, or a computational system such as MATLAB, or both. Many of these curricula include programming in first year engineering courses, integrating the solution of simple engineering problems with an introduction to programming concepts. In line with this practice, Roger Williams University has included an introduction to programming as a part of the first year engineering curriculum for many years. However, recent industry and pedagogical trends have motivated the switch from a structured language (VBA) to a computational system (MATLAB). As a part of the …

Living-Learning Communities Improve First-Year Engineering Student Academic Performance And Retention At A Small Private University, William J. Palm, Charles R. Thomas

Engineering, Computing & Construction Management Faculty Publications

Living-Learning Communities (LLCs), in which students share a residence, one or more classes, and extracurricular activities, have been shown to improve first-year student engagement, academic performance, and retention in non-engineering fields. Research on Engineering LLCs has focused primarily on student engagement. Two studies to examine performance and retention found that LLCs had little effect on first-semester grades but increased first-year retention in engineering by 2 to 12%. Unfortunately, one of these studies did not control for differences in incoming student characteristics, and another used a comparison group that differed little from the LLC group, possibly causing them to understate the …

Change In Chirality Of Semiconducting Single-Walled Carbon Nanotubes Can Overcome Anionic Surfactant Stabilisation: A Systematic Study Of Aggregation Kinetics, Iftheker A. Khan, Joseph R. V. Flora, A. R. M. Nabiul Afrooz, Nirupam Aich, P. Ariette Schierz, P. Lee Ferguson, Tara Sabo-Attwood, Navid B. Saleh

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Single-walled carbon nanotubes’ (SWNT) effectiveness in applications is enhanced by debundling or stabilisation. Anionic surfactants are known to effectively stabilise SWNTs. However, the role of specific chirality on surfactant-stabilised SWNT aggregation has not been studied to date. The aggregation behaviour of chirally enriched (6,5) and (7,6) semiconducting SWNTs, functionalised with three anionic surfactants – sodium dodecyl sulfate, sodium dodecyl benzene sulfonate and sodium deoxycholate – was evaluated with time-resolved dynamic light scattering. A wide range of mono- (NaCl) and divalent (CaCl₂) electrolytes as well as a 2.5 mg total organic carbon (TOC) L^–1 Suwannee River humic acid …

Switchable Release Of Entrapped Nanoparticles From Alginate Hydrogels, Cathal J. Kearney, Hadas Skaat, Stephen M. Kennedy, Jennifer Hu, Max Darnell, Theresa M. Raimondo, David J. Mooney

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Natural biological processes are intricately controlled by the timing and spatial distribution of various cues. To mimic this precise level of control, the physical sizes of gold nanoparticles are utilized to sterically entrap them in hydrogel materials, where they are subsequently released only in response to ultrasound. These nanoparticles can transport bioactive factors to cells and direct cell behavior on‐demand.

Calculus For Decision Systems, Jorge Antonio Samayoa Ranero

Open Access Dissertations

The conceptualization of the term "system" has become highly dependent on the application domain. What a physicist means by the term system might be different than what a sociologist means by the same term. In 1956, Bertalanffy [1] defined a system as " a set of units with relationships among them". This and many other definitions of system share the idea of a system as a black box that has parts or elements interacting between each other. This means that at some level of abstraction all systems are similar, what eventually differentiates one system from another is the set of …

A Network Path Advising Service, Xiongqi Wu

Theses and Dissertations--Computer Science

A common feature of emerging future Internet architectures is the ability for applications to select the path, or paths, their packets take between a source and destination. Unlike the current Internet architecture where routing protocols find a single (best) path between a source and destination, future Internet routing protocols will present applications with a set of paths and allow them to select the most appropriate path. Although this enables applications to be actively involved in the selection of the paths their packets travel, the huge number of potential paths and the need to know the current network conditions of each …

Applying The Analytic Hierarchy Process To Oil Sands Environmental Compliance Risk Management, Izak Johannes Roux

Walden Dissertations and Doctoral Studies

Oil companies in Alberta, Canada, invested $32 billion on new oil sands projects in 2013. Despite the size of this investment, there is a demonstrable deficiency in the uniformity and understanding of environmental legislation requirements that manifest into increased project compliance risks. This descriptive study developed 2 prioritized lists of environmental regulatory compliance risks and mitigation strategies and used multi-criteria decision theory for its theoretical framework. Information from compiled lists of environmental compliance risks and mitigation strategies was used to generate a specialized pairwise survey, which was piloted by 5 subject matter experts (SMEs). The survey was validated by a …

Inventory Optimization In Manufacturing Organizations, Scott William Lemke

Walden Dissertations and Doctoral Studies

Inventories totaling 1.7 trillion U.S. dollars represent an opportunity for U.S. manufacturers. This exploratory case study researched supply chain strategies used to manage inventory in manufacturing operations of a U.S. manufacturing company. A mature value chain contained within a single organization using the value chain framework was the basis for this study. Individual interviews conducted with 16 managers responsible for defining and implementing inventory control strategies, and 4 internal users provided primary information for the study. Other sources of information included a value chain map created through the observation of operations, various inventory measurements, and policies and guidelines related to …

Improving Fracture Toughness Of Silicon Carbide Based Ceramics By Microstructure Tailoring, Sheikh Fahad Ferdous

Mechanical and Aerospace Engineering Dissertations - Archive

Ceramic materials are one of the most promising materials for wide variety of technical applications such as automotive, aerospace, medical, and other applications. They have very high strengths and high melting points relative to metals. However, low fracture toughness is one of the main barriers of ceramics prohibiting their wide-spread applications. This is because ceramics are mainly bonded with directional bonds which don’t allow dislocations based deformation. Several attempts have been made to increase the toughness of ceramic materials without sacrificing significantly the other mechanical properties. Here three different types of SiC based ceramics have been computationally (atomistic and up-scaled …

Novel Device And Methods For Composite Material Characterization, Michael M. Tadros

Mechanical and Aerospace Engineering Dissertations - Archive

Composite materials have several advantages over metallic materials, with their high specific strength and ability to be elastically tailored to create advantageous structural responses. However, the widespread implementation of composite materials in primary structures is limited by our knowledge of how damage mechanisms interact and spread inside composite parts. To date, characterization has been conducted using one of two methods, surface measurements and subsurface measurements. Surface measurements cannot in general capture the failure of multidirectional composite laminates. Subsurface measurements allow for observations of the internal material structure and damage mechanisms inside the composite which might facilitate greater understanding of the …

Computational Analysis Of I.T. Rack Under Vibration Load, Framroz Meheryar Bharucha

Mechanical and Aerospace Engineering Theses - Archive

Structural failure of a rack due to vibration could result in injury to people, damage to IT equipment, or interruption of services that depend on proper functioning of the IT and networking equipment in the rack. In this topic, a computational study of an IT rack and a group of racks placed adjacent to each other under three vibration load scenarios: transportation, office and earthquake vibration is presented.Each rack can weigh as much as 1600 kg (3500 lb.) when fully populated with IT equipment. Two standards commonly used for testing racks with synthetic seismic loads are the GR-63-CORE Network Equipment …

Performance Analysis Of A Helium Cooled Vhtr Powered Brayton Cycle Topping Unit On An Existing Steam Cycle Using Numerical Propulsion System Simulation, Warren Romao Caetano Freitas

Mechanical and Aerospace Engineering Theses - Archive

With the decommissioning of ageing coal power plants due to outdated technology and high levels of air pollution, the advantages of overhauling existing infrastructure is twofold. First, by providing an alternate, sustainable fuel source, like nuclear power, the problem of air pollution can be brought to check. Second, utilizing existing steam plant infrastructure reduces initial investment costs and allows investors to keep the existing steam plant running until the new infrastructure is ready to go online.The focus of this research is to design and analyze the topping cycle required to support an existing 300 MW power plant based on the …

Quantifying Air Flow Rate Through A Server In An Operational Data Center And Assessing The Impact Of Using Theoretical Fan Curve, Neha Shigrekar

Mechanical and Aerospace Engineering Theses - Archive

Cooling is one of the major cost factors in data centres that accounts for 37% of the total data centre electricity consumption. Demands on cooling systems have increased substantially in recent years, due to increasing server densities. To avoid the overheating of servers, cooling aisles are over provisioned, but little attention is paid to the actual scenario at the server level. Cooling requirements of the servers is calculated on the basis of fan manufacturer’s published data for the air flow capacity of the server fan and system impedance data obtained from the server designer put together. Thus, the air flow …

Optimal Operation Of Microgrid Under A Stochastic Environment, Zhaohao Ding

Electrical Engineering Dissertations - Archive

With its technological and regulatory innovation of scale and structure, microgrids have been developed all over the world as a mean to address the high penetration level of renewable generation, reduce the greenhouse gas emission, and provide economical solutions for the currently non-electrified area. The operation of microgrid requires resource planning for those fossil-fuel based generators, energy storage systems, and demand resources if demand side management is implemented. Due to the stochastic nature of renewable energy resources, load behaviors and market prices, enormous uncertainties are involved in the microgrid operation and scheduling problems for both short-term and longer term. These …

Employing Online Data For Dynamic Equivalent Model Parameter Identification Of Large Scale Wind Farm, Xueyang Cheng

Electrical Engineering Dissertations - Archive

As one of the major renewable energy sources, wind power has experienced a fast growth in recent years. The installed capacity of wind farms has increased dramatically. Similar to other generator facilities, their impacts on power system transient stability and power quality should be carefully studied when large scale wind farms are integrated into the power grid. Therefore, it is necessary to establish an accurate dynamic model of large scale wind farm for researches and engineers. A large scale wind farm may have hundreds of WTGs and the structure of WTGs is very complicated and manufacture dependent. If each machine …

Electrostatic And Piezoelectric Micro Energy Harvesters For Environmental Vibrational Energy Scavenging, Yi Li

Electrical Engineering Dissertations - Archive

Nowadays wireless sensors are widely used in all kinds of fields such as biomedical, commercial and military. Micro energy harvesters converting the wasteful energy from environment into electricity enable the possibility of self-powered wireless sensor systems. This dissertation aims to develop micro energy harvesters to harness wasted mechanical vibrational energy. An electrostatic micro energy scavenger was designed to incorporate MEMS comb-drive in-plane overlap as well as in-plane gap closing topologies into one hybrid structure. The device geometry and dimensions were optimized to maximize the energy harvesting efficiency. UV-LIGA process combined with nickel electroplating was utilized to fabricate the devices. A …

A Microwave Backscattering Model For Precipitation, Seda Ermis

Electrical Engineering Dissertations - Archive

A geophysical microwave backscattering model for space borne and ground-based remote sensing of precipitation is developed and used to analyze backscattering measurements from rain and snow type precipitation. Vector Radiative Transfer (VRT) equations for a multilayered inhomogeneous medium are applied to the precipitation region for calculation of backscattered intensity. Numerical solution of the VRT equation for multiple layers is provided by the matrix doubling method to take into account close range interactions between particles. In previous studies, the VRT model was used to calculate backscattering from a rain column on a sea surface [41]. In the model, Mie scattering theory …

Autonomous Robotic Landmine Detection, Mapping And Avoidance, Sandesh Gowda

Electrical Engineering Theses - Archive

The objective of this thesis is to develop detection algorithm to can solve socially challenging issue of Landmine mapping & removal. Landmines which used to be a safety measure during wars, play a dangerous role in civilian life, in and around the post combat regions with approximately 78 countries observing an estimate of 42 human lives killed every day. To prevent the number of casualties and manual mine clearance, mobile robots can be used for detection & mapping of the mine field region.Mapping, detection and avoidance are the primary challenges faced on a landmine removal. In this thesis, mine center …

Lighting Design In Europe: Aligning The Demands For Lower Energy Usage With Better Quality., Kevin Kelly, James Duff

Articles

Lighting design is one of the fastest changing areas in building engineering. It has evolved significantly in recent years due to changing technology and demands for improved quality, better control, reduced energy and sustainability. This paper is an overview of what is happening in Europe and elsewhere and examines the literature to find that latest recommendations in the Code for Lighting issued by the SLL (Society of Light and Lighting) in the UK change previous demands for equal illuminance across a working plane to more specific and demanding criteria. There are recommendations for qualitative metrics and better distribution of light …

Hemodynamic Responses To Thermal Stimulation In The Prefrontal Cortex Of The Brain Measured By Fnirs, Koumudi Chari

Bioengineering Theses - Archive

Although FMRI has marked its importance in the neurological research by understanding the brain activities, FNIRS has also set a new standard in the brain imaging study research with non-invasive and easy to use technology. FNIRS is a portable, inexpensive optical imaging method that measures the changes in the oxygenated and de-oxygenated hemoglobin of the brain that results from the neurological activity. In this study, FNIRS has been used to study the pain processing in humans by measuring the pre-frontal cortex area of the brain. Eight (n=8) healthy subjects were induced with pain using a thermal stimulator device with temperatures …