Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2017

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 2251 - 2280 of 8353

Full-Text Articles in Engineering

Peptide-Directed Nanoparticle Synthesis With A Denovo Pd-Binding Sequence Fused To A Reporter Protein, Rita Eloisa Tejada Vaprio Aug 2017

Peptide-Directed Nanoparticle Synthesis With A Denovo Pd-Binding Sequence Fused To A Reporter Protein, Rita Eloisa Tejada Vaprio

Graduate Theses and Dissertations

There is a need for low-cost nanoparticle materials in the context of new technologies for catalyst development. The purpose of this work was to recombinantly produce a 45- amino acid long metal binding peptide that is useful for nanoparticle synthesis. Using splicing by overlap extension PCR, a synthetic gene containing the fusion of the metal binding peptide with Green Fluorescent Protein (GFPUV) was constructed. The metal binding peptide, fused to reporter protein GFPUV, was expressed using high cell density fermentation. Palladium nanoparticles of an average diameter of 1.18 0.45 nm were synthesized by using the crude cell extract containing the …


A Functional Subnetwork Approach To Designing Synthetic Nervous Systems That Control Legged Robot Locomotion, Nicholas Szczecinski, Alexander J. Hunt, Roger Quinn Aug 2017

A Functional Subnetwork Approach To Designing Synthetic Nervous Systems That Control Legged Robot Locomotion, Nicholas Szczecinski, Alexander J. Hunt, Roger Quinn

Mechanical and Materials Engineering Faculty Publications and Presentations

A dynamical model of an animal’s nervous system, or synthetic nervous system (SNS), is a potentially transformational control method. Due to increasingly detailed data on the connectivity and dynamics of both mammalian and insect nervous systems, controlling a legged robot with an SNS is largely a problem of parameter tuning. Our approach to this problem is to design functional subnetworks that perform specific operations, and then assemble them into larger models of the nervous system. In this paper, we present networks that perform addition, subtraction, multiplication, division, differentiation, and integration of incoming signals. Parameters are set within each subnetwork to …


Effect Of Multiphase Radiation On Coal Combustion In A Pulverized Coal Jet Flame, Bifen Wu, Somesh Roy, Xinyu Zhao, Michael F. Modest Aug 2017

Effect Of Multiphase Radiation On Coal Combustion In A Pulverized Coal Jet Flame, Bifen Wu, Somesh Roy, Xinyu Zhao, Michael F. Modest

Mechanical Engineering Faculty Research and Publications

The accurate modeling of coal combustion requires detailed radiative heat transfer models for both gaseous combustion products and solid coal particles. A multiphase Monte Carlo ray tracing (MCRT) radiation solver is developed in this work to simulate a laboratory-scale pulverized coal flame. The MCRT solver considers radiative interactions between coal particles and three major combustion products (CO2, H2O, and CO). A line-by-line spectral database for the gas phase and a size-dependent nongray correlation for the solid phase are employed to account for the nongray effects. The flame structure is significantly altered by considering nongray radiation and …


Removal Of Nitrates From Stormwater Using Nanoclays, Rubia Siddiqi Aug 2017

Removal Of Nitrates From Stormwater Using Nanoclays, Rubia Siddiqi

Master's Theses

Creeks and rivers are often polluted as a result of stormwater runoff that carries various contaminants in to open water bodies, causing adverse environmental and health effects. Low impact development (LID) techniques are currently employed to treat this runoff prior to discharge. Nitrate, however, is not consistently removed by these LID techniques. This study analyzed the ability of several nanoclays to remove nitrate in runoff and determined the feasibility of using them as a soil supplement for LID implementation. Six different nanoclays and HCl-treated clays were compared (pre-modified trimethyl stearyl ammonium nanoclay, pre-modified dimethyl dialkyl amine nanoclay, unmodified hydrophilic bentonite, …


On-Chip Detection Of Gel Transition Temperature Using A Novel Micro-Thermomechanical Method, Tsenguun Byambadorj, Erfan Dashtimoghadam, Mohamadali Malakoutian, Benyamin Davaji, Lobat Tayebi, James E. Richie, Chung-Hoon Lee Aug 2017

On-Chip Detection Of Gel Transition Temperature Using A Novel Micro-Thermomechanical Method, Tsenguun Byambadorj, Erfan Dashtimoghadam, Mohamadali Malakoutian, Benyamin Davaji, Lobat Tayebi, James E. Richie, Chung-Hoon Lee

Electrical and Computer Engineering Faculty Research and Publications

We present a new thermomechanical method and a platform to measure the phase transition temperature at microscale. A thin film metal sensor on a membrane simultaneously measures both temperature and mechanical strain of the sample during heating and cooling cycles. This thermomechanical principle of operation is described in detail. Physical hydrogel samples are prepared as a disc-shaped gels (200 μm thick and 1 mm diameter) and placed between an on-chip heater and sensor devices. The sol-gel transition temperature of gelatin solution at various concentrations, used as a model physical hydrogel, shows less than 3% deviation from in-depth rheological results. …


Membranes For Food And Bioproduct Processing, Alexandru Marius Avram Aug 2017

Membranes For Food And Bioproduct Processing, Alexandru Marius Avram

Graduate Theses and Dissertations

Modified membranes for process intensification in biomass hydrolysis

Production of biofuels and chemicals from lignocellulosic biomass is one of the leading candidates for replacement of petroleum based fuels and chemicals. However, conversion of lignocellulosic biomass into fuels and chemicals is not cost effective compared to the production of fuels and chemicals from crude oil reserves. Some novel and economically feasible approaches involve the use of ionic liquids as solvents or co-solvents, since these show improved solvation capability of cellulose over simple aqueous systems. Membranes offer unique opportunities for process intensification which involves fractionation of the resulting biomass hydrolysate leading to …


Evaluating Thermal Comfort Of Broiler Chickens During Transportation Using Heat Index And Simulated Electronic Chickens, Kaushik Luthra Aug 2017

Evaluating Thermal Comfort Of Broiler Chickens During Transportation Using Heat Index And Simulated Electronic Chickens, Kaushik Luthra

Graduate Theses and Dissertations

Broilers experience high physiological stress during pre-slaughter transport, especially under extremes of thermal environment. Characterization of thermal environment on the trailer is crucial to identify stress-prone regions during transportation. At the same time, Broilers experience high physiological stress during pre-slaughter transport, especially under extremes of thermal environment. Characterization of thermal environment on the trailer is crucial to identify stress-prone regions during transportation. At the same time, quantification of heat loss of the broilers loaded on trailers is important in understanding the well-being of the broilers. We have developed four electronic chickens (E-chickens) to simulate the sensible heat loss of live …


Decision Support System For Container Port Selection Using Multiple-Objective Decision Analysis, Rivelino De Icaza Aug 2017

Decision Support System For Container Port Selection Using Multiple-Objective Decision Analysis, Rivelino De Icaza

Graduate Theses and Dissertations

Ports are essential for maritime transportation and global supply chains since they are nodes that connect the sea- and land-based modes of transportation. With containerization and supply chains stimulating global trade, ports are challenged to adjust to changes in the market to create value to their customers. Therefore, this dissertation research focuses on the container port selection decision analysis to provide information to help shipping lines select the best port for their shipping networks. Since the problem is complex, dynamic, and involves multiple and conflicting criteria, the research proposes to use the multi-objective decision analysis with Value-Focused Thinking approach. The …


The Effects Of Sprayer Speed And Droplet Size On Herbicide Burndown Efficacy, Justin Carroll Aug 2017

The Effects Of Sprayer Speed And Droplet Size On Herbicide Burndown Efficacy, Justin Carroll

Graduate Theses and Dissertations

An Apache AS1220 self-propelled boom sprayer with a 27.4 m (90 ft) boom was equipped with different sizes (02, 04 and 06) and types (TeeJet AI, XR, AIXR and TTI) of nozzles to achieve medium, very coarse and ultra coarse droplet sizes traveling 11 km/h (7 mph), 19 km/h (12 mph), and 29 km/h (18 mph). These combinations of speed and droplet size were evaluated for percent coverage of the spray and percent control of targeted weeds 3, 7, and 15 days after treatment (DAT). Four replications were conducted for each speed and droplet size combination except for at 19 …


Is It We Or They? The Effect Of Identity On Collaboration And Performance In Buyer-Supplier Relationships, Siqi Ma Aug 2017

Is It We Or They? The Effect Of Identity On Collaboration And Performance In Buyer-Supplier Relationships, Siqi Ma

Graduate Theses and Dissertations

In today’s scale-driven and technology-intensive global economy, collaboration becomes the supply chain’s core capability (Liker and Choi, 2004). A well-developed ability to create and sustain fruitful collaborations gives companies a significant competitive advantage (Kanter, 1994). Retailers are increasingly relying on their suppliers to reduce costs, improve quality, and develop new processes and products faster than their rivals’ vendors can. On the other hand, suppliers benefit from retailers that they are able to monitor store-level demand in real time in order to ensure the top-selling items are in-stock or the accuracy and timeliness of retailer’s demand forecast. Previous literature has shown …


Mushroom Inoculation On Switchgrass Feedstock During Storage: Effects Of Subsequent Pre-Processing For Intended Biofuels Production, Amandeep Singh Turay Aug 2017

Mushroom Inoculation On Switchgrass Feedstock During Storage: Effects Of Subsequent Pre-Processing For Intended Biofuels Production, Amandeep Singh Turay

Graduate Theses and Dissertations

The objective of this project was to examine the effect of fungal treatment and liquid hot water pretreatment of switchgrass combine in view of increasing glucose release. The fungal treatment consisted of incubating Pleurotus ostreatus in square switchgrass bales, at 50% moisture content for 25 days, 54 days, and 82 days. The digestibility of the switchgrass biomass was subsequently evaluated using Accelerase 1500 enzyme. Lignin is an important barrier to enzymatic hydrolysis, and it was stipulated that incubation with P. ostreatus would disrupt plant cell walls, resulting in enhanced saccharification. Three different concentrations of P. ostreatus were evaluated: 0%, 2%, …


Statistical Movement Classification Based On Hilbert-Huang Transform, Shanqi Sun Aug 2017

Statistical Movement Classification Based On Hilbert-Huang Transform, Shanqi Sun

Graduate Theses and Dissertations

The goal of this project is to introduce an automatic movement classification technique of

finger movement signals using Hilbert-Huang Transform (HHT). Due to the nonlinear and

nonstationary processing behavior, movement signals are analyzed with the Hilbert-Huang

Transform (HHT). The slope of auto-correlation function and mean of frequency from first

three Intrinsic Mode Functions (IMFs) was used as feature parameters for each category.

Finally, performing support vector machine (SVM) for pattern classification completes clas-

sifying types of finger movement. According to the records of 669 trial samples of two types

of finger movement signals (thumb and pinky), average accuracy is 93.28%. …


Optimization Of Miniaturized Resonant Microwave Cavities For Use In Q-Thrusters, Joshua Steven Pennington Aug 2017

Optimization Of Miniaturized Resonant Microwave Cavities For Use In Q-Thrusters, Joshua Steven Pennington

Graduate Theses and Dissertations

A gedankenexperiment was considered to compare a hypothetical thruster that used no reaction mass to propulsion methods currently in use. A brief discussion of previous research work done on closed resonant cavity thrust devices was conducted. Using the previous work as a template, a simulation plan was devised. Computational models of resonant microwave cavities were constructed and investigated using COMSOL software. These COMSOL simulations were verified against known analytical solutions using Matlab software as a computational tool. Multiphysics simulations were created to study the microwave heating environment of the resonant cavities. From the COMSOL study outputs, the electromagnetic field magnitude, …


Effects Of Filtration Conditions On Clearance Of Bacteriophage, Rigen Te Aug 2017

Effects Of Filtration Conditions On Clearance Of Bacteriophage, Rigen Te

Graduate Theses and Dissertations

Virus Clearance is one of the major challenges in biopharmaceutical industry, especially in the manufacturing of drugs. U.S. Food and Drug Administration (FDA) recommends using several model bacteriophages as surrogates of pathogenic mammalian virus for process validation. In this work, two bacteriophages were tested against 30 kDa, 100 kDa, 300 kDa polyethersulfone (PES) membranes to investigate the effects of pore size on virus clearance. Virus particles were spiked into the protein feed solutions containing bovine serum albumin (BSA) or lysozyme at different concentrations. Besides protein concentration, the effects of feed pH on the filtration performance and virus rejection were also …


Evaluating Methods For Quantifying Evapotranspiration In Arkansas Rice, Colby Reavis Aug 2017

Evaluating Methods For Quantifying Evapotranspiration In Arkansas Rice, Colby Reavis

Graduate Theses and Dissertations

The goal of this study was to evaluate different methods for quantifying evapotranspiration (ET) in commercial rice fields using different irrigation regimes. The rice fields were located in south central Arkansas. The different irrigation regimes were alternate wetting and drying (AWD) and continuous flooding (CF). Alternate wetting and drying and conventional flooding estimates of ET were 602 mm and 570 mm, respectively, based on field observations using eddy covariance. Models used to estimate ET estimated values between 498 and 653 mm for the 2015 growing season. The Penman Monteith actual evapotranspiration model (PM AET) performed best when compared to the …


Membrane Surface Engineering For Biochemical Applications, Anh T. Vu Aug 2017

Membrane Surface Engineering For Biochemical Applications, Anh T. Vu

Graduate Theses and Dissertations

Synthetic membranes have been frequently used for many fields, such as, the food and beverage, biopharmaceutical, and biofuel industries. In the beer industry, microfiltration frequently suffers from fouling due to the interaction between different species. It is shown that polyphenols can form cross-links with protein molecules, forming insoluble aggregates. However, by adding an optimal amount of polysaccharides these aggregates can be disrupted thus reducing fouling by the aggregates. Confocal laser scanning microscopy (CLSM) is a powerful technique to locate the foulants inside the wet membrane in order to understand more about the behavior of fouling in microfiltration.

Membrane surface modification …


Optimal Constrained Wireless Emergency Network Antenna Placement, Swapnil Gaikwad, David Anastasiu Aug 2017

Optimal Constrained Wireless Emergency Network Antenna Placement, Swapnil Gaikwad, David Anastasiu

Faculty Publications

Communication is paramount, especially during a natural disaster or other emergency. Even when traditional lines of communication become unavailable, emergency response teams must be able to communicate with each other and the outside world. To facilitate this need, major cities across the United States are deploying wireless emergency networks (WENs) that serve as a secure communication channel between emergency response points (police stations, shelters, food banks, hospitals, etc.) and the outside world. An important question when designing such networks is identifying the locations within the city where access points (APs) should be placed to construct a reliable WEN. We propose …


Defects In Skeletal Muscle Subsarcolmmal Mitochondria In A Non-Obese Model Of Type 2 Diabetes Mellitus, Nicola Lai, China Kummitha, Charles Hoppel Aug 2017

Defects In Skeletal Muscle Subsarcolmmal Mitochondria In A Non-Obese Model Of Type 2 Diabetes Mellitus, Nicola Lai, China Kummitha, Charles Hoppel

Electrical & Computer Engineering Faculty Publications

Skeletal muscle resistance to insulin is related to accumulation of lipid-derived products, but it is not clear whether this accumulation is caused by skeletal muscle mitochondrial dysfunction. Diabetes and obesity are reported to have a selective effect on the function of subsarcolemmal and interfibrillar mitochondria in insulin-resistant skeletal muscle. The current study investigated the role of the subpopulations of mitochondria in the pathogenesis of insulin resistance in the absence of obesity. A non-obese spontaneous rat model of type 2 diabetes mellitus, (Goto-Kakizaki), was used to evaluate function and biochemical properties in both populations of skeletal muscle mitochondria. In subsarcolemmal mitochondria, …


Nanostructure Evolution Of Magnetron Sputtered Hydrogenated Silicon Thin Films, Dipendra Adhikari, Maxwell M. Junda, Sylvain X. Marsillac, Robert W. Collins, Nikolas J. Podraza Aug 2017

Nanostructure Evolution Of Magnetron Sputtered Hydrogenated Silicon Thin Films, Dipendra Adhikari, Maxwell M. Junda, Sylvain X. Marsillac, Robert W. Collins, Nikolas J. Podraza

Electrical & Computer Engineering Faculty Publications

Hydrogenated silicon (Si:H) thin films have been prepared by radio frequency (RF) magnetron sputtering. The effect of hydrogen gas concentration during sputtering on the resultant film structural and optical properties has been investigated by real time spectroscopic ellipsometry (RTSE) and grazing incidence x-ray diffraction (GIXRD). The analysis of in-situ RTSE data collected during sputter deposition tracks the evolution of surface roughness and film bulk layer thickness with time. Growth evolution diagrams depicting amorphous, nanocrystalline and mixed-phase regions for low and high deposition rate Si:H are constructed and the effects of process parameter (hydrogen gas concentration, total pressure and RF power) …


Facilitation Of Nanoscale Thermal Transport By Hydrogen Bonds, Lin Zhang Aug 2017

Facilitation Of Nanoscale Thermal Transport By Hydrogen Bonds, Lin Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thermal transport performance at the nanoscale and/or of biomaterials is essential to the success of many new technologies including nanoelectronics, biomedical devices, and various nanocomposites. Due to complicated microstructures and chemical bonding, thermal transport process in these materials has not been well understood yet. In terms of chemical bonding, it is well known that the strength of atomic bonding can significantly affect thermal transport across materials or across interfaces between materials. Given the intrinsic high strength of hydrogen bonds, this dissertation explores the role of hydrogen bonds in nanoscale thermal transport in various materials, and investigates novel material designs incorporating …


Anaplasma Phagocytophilum Infection Modulates Expression Of Megakaryocyte Cell Cycle Genes Through Phosphatidylinositol-3-Kinase Signaling, Supreet Khanal, Hameeda Sultana, John D. Catravas, Jason A. Carlyon, Girish Neelakanta Aug 2017

Anaplasma Phagocytophilum Infection Modulates Expression Of Megakaryocyte Cell Cycle Genes Through Phosphatidylinositol-3-Kinase Signaling, Supreet Khanal, Hameeda Sultana, John D. Catravas, Jason A. Carlyon, Girish Neelakanta

Biological Sciences Faculty Publications

Anaplasma phagocytophilum, the agent of human granulocytic anaplasmosis infects neutrophils and other cells from hematopoietic origin. Using human megakaryocytic cell line, MEG-01, we show that expression of cell cycle genes in these cells are altered upon A. phagocytophilum infection. Expression of several cell cycle genes in MEG-01 cells was significantly up regulated at early and then down regulated at later stages of A. phagocytophilum infection. Lactate dehydrogenase (LDH) assays revealed reduced cellular cytotoxicity in MEG-01 cells upon A. phagocytophilum infection. The levels of both PI3KCA (p110 alpha, catalytic subunit) and PI3KR1 (p85, regulatory subunit) of Class …


Electrical Characterization Of Irradiated Semiconducting Amorphous Hydrogenated Boron Carbide, George Glen Peterson Aug 2017

Electrical Characterization Of Irradiated Semiconducting Amorphous Hydrogenated Boron Carbide, George Glen Peterson

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Semiconducting amorphous partially dehydrogenated boron carbide has been explored as a neutron voltaic for operation in radiation harsh environments, such as on deep space satellites/probes. A neutron voltaic device could also be used as a solid state neutron radiation detector to provide immediate alerts for radiation workers/students, as opposed to the passive dosimetry badges utilized today. Understanding how the irradiation environment effects the electrical properties of semiconducting amorphous partially dehydrogenated boron carbide is important to predicting the stability of these devices in operation. p-n heterojunction diodes were formed from the synthesis of semiconducting amorphous partially dehydrogenated boron carbide on silicon …


Design And Experimentation Of Cable-Driven Platform Stabilization And Control Systems, Matthew Newman Aug 2017

Design And Experimentation Of Cable-Driven Platform Stabilization And Control Systems, Matthew Newman

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Agricultural researchers are constantly attempting to generate crops superior to those currently in use by the world. Whether this means creating crops with greater yield, crops that are more resilient to disease, or crops that can tolerate harsh environments with fewer failures, test plots of these experimental crops must be studied in real-world environments with minimal invasion to determine how they will perform in full-scale agricultural settings. To monitor these crops without interfering on their natural growth, a noninvasive sensor system has been implemented. This system, instituted by the College of Agricultural Sciences and Natural Resources at the University of …


Design And Experimentation Of Cable-Driven Platform Stabilization And Control Systems, Matthew Newman Aug 2017

Design And Experimentation Of Cable-Driven Platform Stabilization And Control Systems, Matthew Newman

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Agricultural researchers are constantly attempting to generate crops superior to those currently in use by the world. Whether this means creating crops with greater yield, crops that are more resilient to disease, or crops that can tolerate harsh environments with fewer failures, test plots of these experimental crops must be studied in real-world environments with minimal invasion to determine how they will perform in full-scale agricultural settings. To monitor these crops without interfering on their natural growth, a noninvasive sensor system has been implemented. This system, instituted by the College of Agricultural Sciences and Natural Resources at the University of …


Cyber-Physical System Characterization And Co-Regulation Of A Quadrotor Uas, Seth E. Doebbeling Aug 2017

Cyber-Physical System Characterization And Co-Regulation Of A Quadrotor Uas, Seth E. Doebbeling

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

An Unmanned Aircraft System (UAS) is a Cyber-Physical System (CPS) in which a host of real-time computational tasks contending for shared resources must be cooperatively managed to obtain mission objectives. Traditionally, control of the UAS is designed assuming a fixed, high sampling rate in order to maintain reliable performance and margins of stability. But emerging methods challenge this design by dynamically allocating resources to computational tasks, thereby affecting control and mission performance. To apply these emerging strategies, a characterization and understanding of the effects of timing on control and trajectory following performance is required. Going beyond traditional control evaluation techniques, …


Development Of The End-Effector Of A Cable-Driven Parallel Manipulator For Automated Crop Sensing, Iman Salafian Aug 2017

Development Of The End-Effector Of A Cable-Driven Parallel Manipulator For Automated Crop Sensing, Iman Salafian

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

A four cable-driven parallel manipulator (4CDPM), consisting of sophisticated spectrometers and imagers, is under development for use in acquiring phenotypic and environmental data over an acre-sized maize field. This thesis presents the design, controls, and testing of two sub-systems in a 4CDPM: a Center of Mass Balance System (CMBS) and a Drop-Down System (DDS).

One of the factors that influences stability is the center of mass (COM) position of the end effector. An offset in COM can cause a pendulum effect or an undesired tilt angle. A center of mass balancing system is presented in this thesis to minimize the …


Stretch Control Of Adipocyte Insulin Signaling, Tasneem Bouzid Aug 2017

Stretch Control Of Adipocyte Insulin Signaling, Tasneem Bouzid

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Obesity and related metabolic disorders have reached global epidemic proportions in recent decades. Excess and hypertrophic adipose tissue has been implicated in the development of various pathological diseases and disorders including Type-2 diabetes mellitus (Type-2 DM). In addition to serving as energy storage for the body, evidence also suggests that adipose tissue behaves as an endocrine organ capable of secreting bioactive cytokines known as adipokines, which mediate insulin signaling pathways in various tissues. Physical exercise has been demonstrated to positively affect insulin signaling activities potentially through increasing the secretion of insulin sensitizing adipokines and/or decreasing the secretion of pro-inflammatory insulin …


Simulation Modeling Approach For Evaluating A Solution Designed To Alleviate The Congestion Of Passenger Flow At The Composure Area Of Security Checkpoints, Maria Luisa Janer Rubio Aug 2017

Simulation Modeling Approach For Evaluating A Solution Designed To Alleviate The Congestion Of Passenger Flow At The Composure Area Of Security Checkpoints, Maria Luisa Janer Rubio

Graduate Theses and Dissertations

In a previous study, we found that replacing the exit roller of a security checkpoint lane for a continuously circulating conveyor could potentially increase the throughput of passengers by over 28% while maintaining the TSA security-waiting time limit (Janer and Rossetti 2016). This study intends to expand this previous effort by investigating the impact of this circulating conveyor on the secondary screening related processes. Leone and Liu (2011) found that imposing a limit on the x-ray screening time, and diverting any item exceeding this limit to secondary screening, could decrease the waiting time by 43%. Our objective is to verify …


Observation And Understanding Of The Initial Unstable Electrical Contact Behaviors, Wanbin Ren, Nan Jiang, Cheng Chang, Shengjun Xue, Yu Chen, Ronald A. Coutu Jr. Aug 2017

Observation And Understanding Of The Initial Unstable Electrical Contact Behaviors, Wanbin Ren, Nan Jiang, Cheng Chang, Shengjun Xue, Yu Chen, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

Reliable and long-lifetime electrical contact is a very important issue in the field of radio frequency microelectromechanical systems (MEMS) and in energy transmission applications. In this paper, the initial unstable electrical contact phenomena under the conditions of micro-newton-scale contact force and nanometer-scale contact gap have been experimentally observed. The repetitive contact bounces at nanoscale are confirmed by the measured instantaneous waveforms of contact force and contact voltage. Moreover, the corresponding physical model for describing the competition between the electrostatic force and the restoring force of the mobile contact is present. Then, the dynamic process of contact closure is explicitly calculated …


Geometric Approaches For Top-K Queries [Tutorial], Kyriakos Mouratidis Aug 2017

Geometric Approaches For Top-K Queries [Tutorial], Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

Top-k processing is a well-studied problem with numerous applications that is becoming increasingly relevant with the growing availability of recommendation systems and decision-making software. The objective of this tutorial is twofold. First, we will delve into the geometric aspects of top-k processing. Second, we will cover complementary features to top-k queries, with strong practical relevance and important applications, that have a computational geometric nature. The tutorial will close with insights in the effect of dimensionality on the meaningfulness of top-k queries, and interesting similarities to nearest neighbor search.