Proportional-Integral-Plus Control Strategy of an Intelligent Excavator

This article considers the application of Proportional-Integral-Plus (PIP) control to the Lancaster University Computerised Intelligent Excavator (LUCIE), which is being developed to dig foundation trenches on a building site. Previous work using LUCIE was based on the ubiquitous PI/PID control algorithm, tuned on-line, and implemented in a rather ad hoc manner. By contrast, the present research utilizes new hardware and advanced model-based control system design methods to improve the joint control and so provide smoother, more accurate movement of the excavator arm. In this article, a novel nonlinear simulation model of the system is developed for MATLAB/SIMULINK, allowing for straightforward refinement of the control algorithm and initial evaluation. The PIP controller is compared with a conventionally tuned PID algorithm, with the final designs implemented on-line for the control of dipper angle. The simulated responses and preliminary implementation results demonstrate the feasibility of the approach

Structural Checking Tool Restructure and Matching Improvements

With the rising complexity and size of hardware designs, saving development time and cost by employing third-party intellectual property (IP) into various first-party designs has become a necessity. However, using third-party IPs introduces the risk of adding malicious behavior to the design, including hardware Trojans. Different from software Trojan detection, the detection of hardware Trojans in an efficient and cost-effective manner is an ongoing area of study and has significant complexities depending on the development stage where Trojan detection is leveraged. Therefore, this thesis research proposes improvements to various components of the soft IP analysis methodology utilized by the Structural Checking Tool. The Structural Checking Tool analyzes the register-transfer level (RTL) code of IPs to determine their functionalities and to detect and identify hardware Trojans inserted. The Structural Checking process entails parsing a design to yield a structural representation and assigning assets that encompass 12 different characteristics to the primary ports and internal signals. With coarse-grained asset reassignment based on external and internal signal connections, matching can be performed against trusted IPs to classify the functionality of an unknown soft IP. Further analysis is done using a Golden Reference Library (GRL) containing information about known Trojan-free and Trojan-infested designs and serves as a vital component for unknown soft IP comparison. Following functional identification, the unknown soft IP is run through a fine-grained reassignment strategy to ensure usage of up-to-date GRL assets, and then the matching process is used to determine whether said IP is Trojan-infested or Trojan-free. This necessitates a large GRL while maintaining a balance of computational resources and high accuracy to ensure effective matching

Stoking the Fires: The Relationship between Mary Tudor and Eustace Chapuys, 1529-1545

Most published research regarding the court of King Henry VIII and the early years of the English Reformation has relied upon the correspondence of ambassador Eustace Chapuys. Although Chapuys’ assessments of the goings on in England at the time have been often disputed among scholars in regard to their accuracy, little research has been attempted to understand the man writing the letters that have so frequently been cited. During his sixteen years as ambassador Chapuys became a close friend of Henry’s eldest living child, Mary Tudor, who later became Queen Mary I. This relationship has previously gone unexplored. This thesis examines the relationship between Mary and Chapuys through research of primary documents from the letters of Chapuys and others. It also makes extensive use of works by researchers of sixteenth-century England, who have often misjudged Chapuys’ personality and role in the events that took place in the 1530s and 1540s

The design and testing of a horizontal axis wind turbine with sailfoil blades

The work contained in this thesis covers the design, development and testing of a horizontal axis wind turbine (HAWT) with Sailfoil blades. Included is a brief history of wind turbine technology, its revival, a review of current wind energy developments and a literature survey of previous work on wind turbines with sail type blades. The Sailfoil blade consists of a framework of a leading edge D spar and a rigid trailing edge spar over which is stretched a fabric sock, forming a wing-like surface. The aerodynamic performance theories of HAWTs are described, as is the aerodynamic, structural and mechanical design of a 4 metre diameter, 3 bladed HAWT with Sailfoil blades. A wind turbine test facility was designed and developed for free air testing of wind turbines and is described. Free air tests were carried out on the Sailfoil wind turbine on the test facility to obtain power coefficient versus tip speed ratio curves and power versus wind speed curves for the wind turbine. These are presented and compared to predicted values

EFFECTS OF STATOR PLATFORM GEOMETRY FEATURES ON BLADE ROW PERFORMANCE

Real geometry features such as shroud cavities, interplatform and vane-pack gaps can affect the hub endwall flow through compressor blade rows. Additionally, misalignment of the platform endwalls due to manufacturing tolerances can be important. This paper details an experimental and computational investigation of these effects. To ensure that the measurements were representative a novel experimental technique was developed to generate end-wall skew in the linear cascade. Without the presence of the endwall boundary layer skew the cascade flow did not capture the flow features typically observed in multi-stage compressor operation. The skew generation method involves injecting flow along the endwall in such a manner as to control both the displacement thickness and tangential momentum thickness of the resulting boundary layer. The study reveals that real geometry features can have a significant impact on the flowfield within a blade passage. For stator shrouds, increasing leakage flow rates increases the stagnation pressure loss coefficient however, increasing the level of whirl pickup of the leakage flow can offset the natural secondary flow and thus reduce the loss. All of the steps and gaps that were found to be present in real compressors were found to increase the losses relative to a smooth endwall. It is also shown that CFD simulations are capable in capturing the trends observed in the experiments.Rolls-Royce pl

Early Identification of Students at Risk for High School Dropout

For years, many have hoped to identify why high school students drop out. Typically, studies focus on factors identified in high school or middle school. By tracking a cohort of North Carolina students from third grade onward, we attempt to identify areas for intervention even earlier in order to prevent dropouts. Indeed, we find that variables that can be viewed as indicators of high risk for drop out in middle school are already measurably present as early as third grade. This suggests interventions can begin when students are still very young and when treatment is likely to be more effective.Honors thesi

The evolution of novel fungal genes from non-retroviral RNA viruses

<p>Abstract</p> <p>Background</p> <p>Endogenous derivatives of non-retroviral RNA viruses are thought to be absent or rare in eukaryotic genomes because integration of RNA viruses in host genomes is impossible without reverse transcription. However, such derivatives have been proposed for animals, plants and fungi, often based on surrogate bioinformatic evidence. At present, there is little known of the evolution and function of integrated non-retroviral RNA virus genes. Here, we provide direct evidence of integration by sequencing across host-virus gene boundaries and carry out phylogenetic analyses of fungal hosts and totivirids (dsRNA viruses of fungi and protozoans). Further, we examine functionality by tests of neutral evolution, comparison of residues that are necessary for viral capsid functioning and assays for transcripts, dsRNA and viral particles.</p> <p>Results</p> <p>Sequencing evidence from gene boundaries was consistent with integration. We detected previously unknown integrated <it>Totivirus</it>-like sequences in three fungi (<it>Candida parapsilosis</it>, <it>Penicillium marneffei </it>and <it>Uromyces appendiculatus</it>). The phylogenetic evidence strongly indicated that the direction of transfer was from <it>Totivirus </it>to fungus. However, there was evidence of transfer of <it>Totivirus</it>-like sequences among fungi. Tests of selection indicated that integrated genes are maintained by purifying selection. Transcripts were apparent for some gene copies, but, in most cases, the endogenous sequences lacked the residues necessary for normal viral functioning.</p> <p>Conclusions</p> <p>Our findings reveal that horizontal gene transfer can result in novel gene formation in eukaryotes despite miniaturized genomic targets and a need for co-option of reverse transcriptase.</p

Transglobal comparisons of nuclear and mitochondrial genetic structure in a marine polyploid clam ( Lasaea , Lasaeidae)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75076/1/j.1365-2540.2000.00673.x.pd