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Search Results: 1 - 10 of 406329 matches for " Kevin M. Farinholt "
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Damage Identification of Wind Turbine Blades Using Piezoelectric Transducers
Seong-Won Choi,Kevin M. Farinholt,Stuart G. Taylor,Abraham Light-Marquez,Gyuhae Park
Shock and Vibration , 2014, DOI: 10.1155/2014/430854
Abstract: This paper presents the experimental results of active-sensing structural health monitoring (SHM) techniques, which utilize piezoelectric transducers as sensors and actuators, for determining the structural integrity of wind turbine blades. Specifically, Lamb wave propagations and frequency response functions at high frequency ranges are used to estimate the condition of wind turbine blades. For experiments, a 1?m section of a CX-100 blade is used. The goal of this study is to assess and compare the performance of each method in identifying incipient damage with a consideration given to field deployability. Overall, these methods yielded a sufficient damage detection capability to warrant further investigation. This paper also summarizes the SHM results of a full-scale fatigue test of a 9?m CX-100 blade using piezoelectric active sensors. This paper outlines considerations needed to design such SHM systems, experimental procedures and results, and additional issues that can be used as guidelines for future investigations. 1. Introduction Wind turbines are becoming a larger source of renewable energy in the world. The US government projects that 20% of the US electrical supply could be produced via wind power by 2030 [1]. To achieve this goal, the turbine manufacturers have been increasing the size of the turbine blades, often made of composite materials, to maximize power output. As a result of severe wind loadings and the material level flaws in composite structures, blade failure has been a more common occurrence in the wind industry. Monitoring the structural health of the turbine blades is particularly important as they account for 15–20% of the total turbine cost. In addition, blade damage is the most expensive type of damage to repair and can cause serious secondary damage to the wind turbine system due to rotating imbalance created during blade failure. Therefore, it is imperative that a structural health monitoring (SHM) system be incorporated into the design of the wind turbines in order to monitor flaws before they lead to a catastrophic failure. There has been a considerable research effort focused on applying SHM techniques on wind turbine blades [2, 3]. However, most of these studies focus on a single technique for damage detection; consequently very little work has been done to compare the results of multiple active-sensing techniques. Thus, the goal of this study is to assess the relative performance of high-frequency SHM techniques, namely, Lamb wave propagation and frequency response functions (FRFs), as a way to nondestructively
An Ideal Characterization of the Clifford Operators
J. M. Farinholt
Mathematics , 2013, DOI: 10.1088/1751-8113/47/30/305303
Abstract: The Clifford operators are an important and well-studied subset of quantum operations, in both the qubit and higher-dimensional qudit cases. While there are many ways to characterize this set, this paper aims to provide an ideal characterization, in the sense that it has the same characterization in every finite dimension, is characterized by a minimal set of gates, is constructive, and does not make any assumptions about non-Clifford operations or resources (such as the use of ancillas or the ability to make measurements). While most characterizations satisfy some of these properties, this appears to be the first characterization satisfying all of the above. As an application, we use these results to briefly analyze characterizations of Clifford embeddings, that is, the action of logical Clifford operations acting on qunits embedded in higher-dimensional qudits, inside the qudit Clifford framework.
The Geometry of Qubit Weak Values
J. M. Farinholt,A. Ghazarians,J. E. Troupe
Physics , 2015,
Abstract: The concept of a \emph{weak value} of a quantum observable was developed in the late 1980s by Aharonov and colleagues to characterize the value of an observable for a quantum system in the time interval between two projective measurements. Curiously, these values often lie outside the eigenspectrum of the observable, and can even be complex-valued. Nevertheless, the weak value of a quantum observable has been shown to be a valuable resource in quantum metrology, and has received recent attention in foundational aspects of quantum mechanics. This paper is driven by a desire to more fully understand the underlying mathematical structure of weak values. In order to do this, we allow an observable to be \emph{any} Hermitian operator, and use the pre- and post-selected states to develop well-defined linear maps between the Hermitian operators and their corresponding weak values. We may then use the inherent Euclidean structure on Hermitian space to geometrically decompose a weak value of an observable. In the case in which the quantum systems are qubits, we provide a full geometric characterization of weak values.
Pauli Automorphisms, Clifford Groups, and Local Clifford Groups for Higher-Dimensional Systems
Jacob Farinholt
Physics , 2012,
Abstract: NOTE: PAPER WITHDRAWN (See Comments) The Clifford and Local Clifford groups for $d > 2$ dimensional systems have been topics of recent interest due to their applications in graph states, quantum codes, and possible applications in fast quantum algorithms. This paper studies these groups more abstractly, by first characterizing the Pauli Automorphism and Local Automorphism groups, and then using these results to determine characteristics of the Clifford and Local Clifford groups. Not only does such an approach reveal new information about the Clifford and Local Clifford groups, but it also shows how many previously derived results arise naturally as simple corollaries. Lastly, we give a systematic method of building an arbitrary Local Clifford operator from a small number of previously known gates, as well as a method to physically implement such an operator.
Self-Regulation of Goals and Performance: Effects of Discrepancy Feedback, Regulatory Focus, and Self-Efficacy  [PDF]
Jessica M. Nicklin, Kevin J. Williams
Psychology (PSYCH) , 2011, DOI: 10.4236/psych.2011.23030
Abstract: We adopted a social cognitive approach of motivation (Bandura, 1986, 1989, 2002) to examine the influence of normative feedback and self-set goals on positive discrepancy creation and goal revision in the face of a novel task. The moderating effects of self-efficacy and regulatory focus were also examined. A laboratory study in-cluding 297 undergraduate students demonstrated that feedback, whether based on normative standards of performance or goal-performance discrepancies was a strong predictor of positive discrepancy creation and goal revision. Self-efficacy was also an independent predictor of goal revision, but regulatory focus was not. These findings have important practical implications for a variety of performance contexts (e.g., work, school, sports). Individuals will modify their goals based largely on feedback received (goal-performance discrepancies and normative standards); however, self-efficacy independently influences goal revision beyond the effects of feed-back. Other implications for research and practice are discussed.
A Preliminary Investigation of the Optimal Percentage Requirement in an Electricity Market with Tradable Green Certificates  [PDF]
Kevin M. Currier, Susanne Rassouli-Currier
Theoretical Economics Letters (TEL) , 2012, DOI: 10.4236/tel.2012.22039
Abstract: Around the world, energy markets are being liberalized with the goal of achieving fully competitive markets while at-taining environmental policy objectives. This paper considers a system of Tradable Green Certificates (TGCs)—a mar-ket based regulatory instrument designed to promote electricity generation from renewable energy sources. In a TGC program, the principal policy instrument is the “percentage requirement” which stipulates the percentage of total elec-tricity generation that must be obtained from renewable sources. This paper provides a preliminary investigation of the socially optimal choice of the percentage requirement in a Cournot duopoly setting. The paper discusses the problem geometrically and considers some of the practical difficulties associated with the determination of the optimal percent-age requirement. Several important avenues for generalization of the results are also discussed.
Psychosocial Correlates of the Short-Form-36 Multidimensional Health Survey in University Students  [PDF]
M. Scott DeBerard, Kevin S. Masters
Psychology (PSYCH) , 2014, DOI: 10.4236/psych.2014.58104
Abstract:

Stress, social support, and coping correlates of the Short-Form 36 Health Survey (SF-36) were examined in 307 undergraduate students. Instruments included the SF-36, the Perceived Stress Scale, the Multidimensional Scale of Perceived Social Support, and the Ways of Coping Inventory-Revised. HRQOL appeared worse and reported stress and use of maladaptive coping strategies were higher than age-appropriate national norms. Stress, social-support, and coping strategies were correlated with SF-36 physical and mental health subscales. In a stepwise multiple regression equation predicting the SF-36 Mental Health Composite Scale, stress, escape-avoidance coping, problem-focused coping, and accepting-responsibility coping emerged as significant predictors. In another stepwise multiple regression equation predicting the SF-36 Physical Composite Scale, self-control coping and family support emerged as significant predictors. Results suggest that psychosocial measures are excellent predictors of mental HRQOL but are not as strong for physical HRQOL. Possible interventions for improving health status among college students are offered.

Antibacterial Activity of Acylglucinol Derivatives against Flavobacterium columnare  [PDF]
Kumudini M. Meepagala, Kevin K. Schrader
Journal of Agricultural Chemistry and Environment (JACEN) , 2014, DOI: 10.4236/jacen.2014.33011
Abstract: Columnaris (caused by Flavobacterium columnare) is one of the most common bacterial diseases affecting the pond-raised channel catfish (Ictalurus punctatus) in the southeastern United States of America resulting in annual losses of millions of dollars. As part of our continuing effort to discover environmentally benign compounds for the control of columnaris disease, acyl derivatives of phloroglucinol were synthesized and tested against F. columnare using a rapid bioassay. Among the analogs that were tested, diacyl analogs showed very high antibacterial activity against F. columnare in the laboratory bioassay. Diisovaleryl and diisobutyryl analogs were found to have the strongest activity against F. columnare (isolate ALM-00-173) based on 24-h 50% inhibitory concentration (IC50) and minimum inhibitory concentration (MIC). Diisovaleryl and diisobutyryl analogs had IC50 values 0.82 mg/L and 0.80 mg/L, respectively, whereas the drug control florfenicol had an IC50 value of 0.81 mg/L. Diisovaleryl and diisobutyryl analogs also had 24-h relative-to- drug-control IC50 values around 1.0 indicating activities similar to florfenicol, which is included in medicated feed and is one of the current management approach for columnaris.
Why Buildings Fail: Are We Learning From Our Mistakes?
M. Kevin Parfitt
Buildings , 2012, DOI: 10.3390/buildings2030326
Abstract: Most building professionals have investigated or performed remedial designs for at least one architectural or engineering system failure during their careers. Other practitioners, especially those who work for forensic consultants or firms specializing in disaster response and repair, are more familiar with the variety and extent of building failures as they assist their clients in restoring damaged or deficient buildings. The advent of social medial and twenty-four-hour news channels along with the general ease of finding more examples of failures in the Internet have made us realize that building failures in the broad sense are much more common than we may have realized.Relatively recent events leading to building failures such as the Christchurch, New Zealand earthquakes, the roof/parking deck of the Algo Centre mall in the northern Ontario, Canada city of Elliot Lake and the Indiana State Fairground stage collapse in the US are just a few reminders that much more work needs to be done on a variety of fronts to prevent building failures from a life safety standpoint. The need is compounded by economic concerns from what would be considered more mundane or common failures. Inspections by the author after Hurricane Katrina revealed a huge number of failures associated rain water alone as roofs, windows, flashing, mechanical penetrations etc. failed leading to interior water penetration often resulting in more damage from damp conditions and mold propagation than outright structural collapses.
Dissecting complex traits: recent advances in hypertension genomics
Kevin M O'Shaughnessy
Genome Medicine , 2009, DOI: 10.1186/gm43
Abstract: The idea that blood pressure (BP) and (by definition) hypertension are polygenic traits arose half a century ago from the famous debate between George Pickering and Robert Platt about the nature of the frequency distribution of BP [1].Many epidemiological studies have subsequently confirmed the heritability of BP; however, its inheritance is not Mendelian as Platt believed, but rather complex. In fact the major diseases of industrialized societies, including obesity, diabetes, and coronary artery disease (CAD), have complex genetics. The favored model for these complex diseases is often referred to as the 'common disease-common variant' hypothesis (CD-CV), in which each susceptibility locus in the human genome for a complex disease is explained by a single (or a handful of) gene variant(s) or allele(s) [2]. This relatively simple allelic architecture, of many susceptibility genes but few variants of each gene, has not been extensively tested. Some loci do fall neatly into this classification, such as the ApoE locus in CAD [3] and PPARG in type 2 diabetes [4], which have single coding variants. However, others, such as the NOD2 locus in Crohn's disease [4] or the calpain 10 (CAPN10) locus in type 2 diabetes [5], cannot be explained so simply. To date, the problem for essential hypertension has been more fundamental, with a difficulty in confidently identifying any susceptibility loci. Linkage-based approaches have been used, but they require family structures that are difficult to recruit in very large numbers. Even when linked loci have been identified [6], there remains the formidable task of finding a functional variant within a locus that perhaps covers a substantial fraction of a chromosome and contains hundreds of genes.In contrast to the difficulties of using linkage, association studies are ideally suited for chasing putative CD-CV gene variants. Initially, association studies explored individual candidate genes, but key genomic discoveries and technological
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