Integer k-matching preclusion of graphs

As a generalization of matching preclusion number of a graph, we provide the (strong) integer $k$-matching preclusion number, abbreviated as $MP^{k}$ number ($SMP^{k}$ number), which is the minimum number of edges (vertices and edges) whose deletion results in a graph that has neither perfect integer $k$-matching nor almost perfect integer $k$-matching. In this paper, we show that when $k$ is even, the ($SMP^{k}$) $MP^{k}$ number is equal to the (strong) fractional matching preclusion number. We obtain a necessary condition of graphs with an almost-perfect integer $k$-matching and a relational expression between the matching number and the integer $k$-matching number of bipartite graphs. Thus the $MP^{k}$ number and the $SMP^{k}$ number of complete graphs, bipartite graphs and arrangement graphs are obtained, respectively.Comment: 18 pages, 5 figure

The characterisation of growth hormone-related cardiac disease with magnetic resonance imaging & The effects of growth hormone dysregulation on adenosine monophosphate-activated protein kinase in cardiac tissue

PhDChronic growth hormone (GH) excess, acromegaly, causes a specific cardiomyopathy, which remains poorly understood. The pattern of hypertrophy is distinct from other forms of cardiac disease and begins to appear before hypertension or diabetes. GH deficiency (GHD) also causes cardiovascular problems, with reduced ability to mount a cardiovascular response to exercise. Acromegaly and GHD patients have increased cardiac mortality. Cardiac magnetic resonance imaging (CMR) is the gold standard for assessment of cardiac mass and provides data on cardiac function, fibrosis, valve function and ischaemia. This study used CMR to assess 23 patients with acromegaly or GHD, before and after treatment of their GH disorder, and 23 healthy controls. Patients with acromegaly demonstrated increased left ventricular mass index (LVMi), end diastolic volume index, stroke volume index and cardiac index, which persisted at one year, despite treatment of underlying disease. Patients with GHD demonstrated LVMi at the bottom (males) or beneath (females) published normal references ranges, which increased with one year of GH replacement. The mechanisms by which GH influences cardiac tissue are poorly understood. Adenosine monophosphate-activated protein kinase (AMPK) is an energy-regulator enzyme, which interacts with several metabolic hormones. Mutations in AMPK cause arrhythmias and cardiac hypertrophy. AMPK activation may be a mechanism by which GH causes some of its cardiac effects. This study used primary cardiomyocytes and mouse and rat models of GH excess and deficiency to study the effects of GH on cardiac AMPK. Acute GH treatment increased AMPK activity in both in vivo and in vitro studies; acute IGF-I treatment had the opposite effect. In 2 and 8 month old bovine GH-overexpressing (bGH) and GH receptor knock out (GHRKO) mice, functional AMPK assay did not demonstrate any difference in cardiac AMPK activity between transgenics and controls. However, Western blotting for Threonine-172 phospho (p)AMPK levels, a marker of AMPK activity, demonstrated increased cardiac pAMPK in 2 month old bGH mice and a reduction in cardiac pAMPK levels in 8 month old animals. A trend towards the same findings was seen in GHRKO mice. This indicates that both GH and IGF-I interact with myocardial AMPK, apparently via different mechanisms

Dielectric-barrier discharge plasma actuators for turbulent friction-drag manipulation via spanwise oscillations

Ein Plasmaaktuator wird über instationäre Betriebsmodi angesteuert, um wandnahe Fluidoszillationen zu erzeugen. Das Ziel ist es, spannweitig oszillierende Wände zugunsten einer Verringerung des turbulenten Reibungswiderstands nachzuahmen. Da der Aktuator keine beweglichen Teile besitzt, könnte er sich als nicht-mechanischer Ersatz der oszillierenden Wand eignen. Die Kombination von Betriebsmodus und zugrundeliegender Elektrodenanordnung ist eine Neuerung, welche die spannweitige Homogenität der Strömung solcher virtuellen Wandoszillationen verbessert. Die mechanische Charakterisierung wird mittels eines planaren Feldmessverfahrens durchgeführt, um sowohl die induzierten Strömungstopologien als auch die Effekte von Volumenkraft und „virtueller Wandgeschwindigkeit“, d.h. Reaktion des Fluids, aufzuzeigen. Daraus wird zur Bewertung und Optimierung der Leistungsfähigkeit des Aktuators ein universelles Diagramm hinsichtlich aktuatorspezifischer Parameter abgeleitet. Da die berechnete Volumenkraft die Art der Kraftausübung gut widerspiegelt, kann diese modellhaft zu verbesserten numerischen Simulationen der Aktuatorik dienen. Ferner wird eine neue Vorgehensweise für die Bestimmung der elektrischen Leistung von Aktuatoren mit mehreren Hochspannungselektroden bereitgestellt, welche die potenzielle Abschätzung des Nettogewinns in aktiven Kontrollszenarien ermöglicht. Zuletzt wird die unmittelbare Auswirkung der oszillatorischen Kraftausübung auf den Reibungswiderstand in der Querebene einer voll entwickelten turbulenten Kanalströmung mittels einer stereoskopischen Feldmesstechnik untersucht. Im Wesentlichen verbleibt die Strömung im sich entwickelnden Stadium und erfährt auf dem Aktuator eine Erhöhung des Reibungswiderstands, während sich dieser stromab des Aktuators verringert

Essentials of forensic accounting

https://egrove.olemiss.edu/aicpa_guides/2728/thumbnail.jp

Comparison of the vocabularies of the Gregg shorthand dictionary and Horn-Peterson's basic vocabulary of business letters

This study is a comparative analysis of the vocabularies of Horn and Peterson's The Basic Vocabulary of Business Letters1 and the Gregg Shorthand Dictionary.2 Both books purport to present a list of words most frequently encountered by stenographers and students of shorthand. The, Basic Vocabulary of Business Letters, published "in answer to repeated requests for data on the words appearing most frequently in business letters,"3 is a frequency list specific to business writing. Although the book carries the copyright date of 1943, the vocabulary was compiled much earlier. The listings constitute a part of the data used in the preparation of the 10,000 words making up the ranked frequency list compiled by Ernest Horn and staff and published in 1926 under the title of A Basic Writing Vocabulary: 10,000 Words Lost Commonly Used in Writing. The introduction to that publication gives credit to Miss Cora Crowder for the contribution of her Master's study at the University of Minnesota concerning words found in business writing. With additional data from supplementary sources, the complete listing represents twenty-six classes of business, as follows 1. Miscellaneous 2. Florists 3. Automobile manufacturers and sales companie

DEVELOPMENT OF A SIMPLIFIED, MASS PRODUCIBLE HYBRIDIZED AMBIENT, LOW FREQUENCY, LOW INTENSITY VIBRATION ENERGY SCAVENGER (HALF-LIVES)

Scavenging energy from environmental sources is an active area of research to enable remote sensing and microsystems applications. Furthermore, as energy demands soar, there is a significant need to explore new sources and curb waste. Vibration energy scavenging is one environmental source for remote applications and a candidate for recouping energy wasted by mechanical sources that can be harnessed to monitor and optimize operation of critical infrastructure (e.g. Smart Grid). Current vibration scavengers are limited by volume and ancillary requirements for operation such as control circuitry overhead and battery sources. This dissertation, for the first time, reports a mass producible hybrid energy scavenger system that employs both piezoelectric and electrostatic transduction on a common MEMS device. The piezoelectric component provides an inherent feedback signal and pre-charge source that enables electrostatic scavenging operation while the electrostatic device provides the proof mass that enables low frequency operation. The piezoelectric beam forms the spring of the resonant mass-spring transducer for converting vibration excitation into an AC electrical output. A serially poled, composite shim, piezoelectric bimorph produces the highest output rectified voltage of over 3.3V and power output of 145uW using ¼ g vibration acceleration at 120Hz. Considering solely the volume of the piezoelectric beam and tungsten proof mass, the volume is 0.054cm3, resulting in a power density of 2.68mW/cm3. Incorporation of a simple parallel plate structure that provides the proof mass for low frequency resonant operation in addition to cogeneration via electrostatic energy scavenging provides a 19.82 to 35.29 percent increase in voltage beyond the piezoelectric generated DC rails. This corresponds to approximately 2.1nW additional power from the electrostatic scavenger component and demonstrates the first instance of hybrid energy scavenging using both piezoelectric and synchronous electrostatic transduction. Furthermore, it provides a complete system architecture and development platform for additional enhancements that will enable in excess of 100uW additional power from the electrostatic scavenger

Integrated approaches to the optimization of process-utility systems

The goal of this work is to develop a conceptual framework and computational tools for the optimization of utility systems in the process industries. The emphasis is devoted to the development of systematic design techniques aimed at identifying modifications to the process and the associated utility-systems to jointly optimize the process and the utility system. The following contributions describe the specific results of this work: • Development of shortcut methods for modeling and optimizing steam systems and basic thermodynamic cycles with the objective of using these methods in the optimization of combined heat and power. To enable efficient mathematical programming formulations, simple yet accurate correlations have been developed for the thermodynamic properties of steam in the utility system. • Optimization of multi-level steam system for combined process requirements and power cogeneration. A general procedure is developed to determine rigorous cogeneration targets and the optimal configuration of the system with the associated design and operating variables. • Graph theory methods are also used to optimize the pipeline layout in the plant for the distributing the utilities. • Finally, because of the nonconvex nature of much of the developed optimization formulations, a global optimization method has also been suggested by using interval analysis and simulated annealing. The techniques proposed in this work are compared to previous works and their applicabilities are presented in case studies. These techniques outperform previously suggested ones in terms of the accuracy, computational efficiency and/or optimality