25,265 research outputs found
A New Method to Improve the Sensitivity of Leak Detection in Self-Contained Fluid-filled Cables
A method of real-time detection of leaks for self-contained fluid-filled cables without taking them out of service has been assessed and a novel machine learning technique, i.e. support vector regression (SVR) analysis has been investigated to improve the detection sensitivity of the self-contained fluid-filled (FF) cable leaks. The condition of a 400 kV underground FF cable route within the National Grid transmission network has been monitored by Drallim pressure, temperature and load current measurement system. These three measured variables are used as parameters to describe the condition of the cable system. In the regression analysis the temperature and load current of the cable circuit are used as independent variables and the pressure within cables is the dependent variable to be predicted. As a supervised learning algorithm, the SVR requires data with known attributes as training samples in the learning process and can be used to identify unknown data or predict future trends. The load current is an independent variable to the fluid-filled system itself. The temperature, namely the tank temperature is determined by both the load current and the weather condition i.e. ambient temperature. The pressure is directly relevant to the temperature and therefore also correlated to the load current. The Gaussian-RBF kernel has been used in this investigation as it has a good performance in general application. The SVR algorithm was trained using 4 days data, as shown in Figure 1, and the optimized SVR is used to predict the pressure using the given load current and temperature information
Phase-space analysis of bosonic spontaneous emission
We present phase-space techniques for the modelling of spontaneous emission
in two-level bosonic atoms. The positive-P representation is shown to give a
full and complete description and can be further developed to give exact
treatments of the interaction of degenerate bosons with the electromagnetic
field in a given experimental situation. The Wigner representation, even when
truncated at second order, is shown to need a doubling of the phase-space to
allow for a positive-definite diffusion matrix in the appropriate Fokker-Planck
equation and still fails to agree with the full quantum results of the
positive-P representation. We show that quantum statistics and correlations
between the ground and excited states affect the dynamics of the emission
process, so that it is in general non-exponential.Comment: 16 pages, 6 figure
Leading, Learning, and Leadership Support
Offers a framework for improving learning-focused leadership through the use of data and evidence, reallocation of resources, redefined roles and responsibilities, assessment of leadership performance, better governance, and a focus on high schools
Eigenspace techniques for active flutter suppression
The use of eigenspace techniques for the design of an active flutter suppression system for a hypothetical research drone is discussed. One leading edge and two trailing edge aerodynamic control surfaces and four sensors (accelerometers) are available for each wing. Full state control laws are designed by selecting feedback gains which place closed loop eigenvalues and shape closed loop eigenvectors so as to stabilize wing flutter and reduce gust loads at the wing root while yielding accepatable robustness and satisfying constrains on rms control surface activity. These controllers are realized by state estimators designed using an eigenvalue placement/eigenvector shaping technique which results in recovery of the full state loop transfer characteristics. The resulting feedback compensators are shown to perform almost as well as the full state designs. They also exhibit acceptable performance in situations in which the failure of an actuator is simulated
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âI havenât heard anything about religion whatsoeverâ: Audience perceptions of anti-Muslim racism in Sacha Baron Cohenâs The Dictator
Since the late 1990s, Sacha Baron Cohen's characters have raised controversy, criticism and protest from various groups (for example, from Black activists in 2002 and Hasidic Jews in 2012). The comedy has also been described as satirical or anti-racist. Baron Cohen, as either Ali G, Borat, Bruno or General Aladeen, has consistently provided comedy that leads to public debate on the relationship between comedy and race, ethnicity and stereotype, and the nature of racism and âotheringâ in comedy. Despite this significance, very little research has been conducted on how audiences receive the comedy. We present results from a recent focus group, audience reception study of the comedy of Baron Cohen, which recorded discourse from young people aged 18 to 29 years (n 49). The article examines the perceptions of Islamophobia or anti-Muslim racism in the comedy, focusing on The Dictator. Four discourses are outlined from the focus groups. First, discussions that show agreement in the focus group and argue the comedy is Islamophobic or anti-Muslim; second, discussions that show disagreement in the focus group over the presence of Islamophobic or anti-Muslim content; third, discussions that view no, or almost no, signifiers in the comedy that denote either Islam as a religion or Muslims as an ethnic group; and forth, one example that suggests the comedy uses signifiers of the âotherâ for ironic satire. These conversations are analysed through rhetorical discourse analysis to highlight the tropes that construct meaning in each.The project was funded by a Brunel Research Initiative & Enterprise Fund 2013/14 (BRIEF award), Brunel University â âExamining âRaceâ, Racism and Representation: An audience reception study of the comedy of Sacha Baron Cohenâ
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Assessing Feeding Damage from Two Leaffooted Bugs, Leptoglossus clypealis Heidemann and Leptoglossus zonatus (Dallas) (Hemiptera: Coreidae), on Four Almond Varieties.
Leaffooted bugs (Leptoglossus spp; Hemiptera: Coreidae) are phytophagous insects native to the Western Hemisphere. In California, Leptoglossus clypealis and Leptoglossus zonatus are occasional pests on almonds. Early season feeding by L. clypealis and L. zonatus leads to almond drop, while late season feeding results in strikes on kernels, kernel necrosis, and shriveled kernels. A field cage study was conducted to assess feeding damage associated with L. clypealis and L. zonatus on four almond varieties, Nonpareil, Fritz, Monterey, and Carmel. The objectives were to determine whether leaffooted bugs caused significant almond drop, to pinpoint when the almond was vulnerable, and to determine the final damage at harvest. Branches with ~20 almonds were caged and used to compare almond drop and final damage in four treatments: (1) control branches, (2) mechanically punctured almonds, (3) adult Leptoglossus clypealis, and (4) adult Leptoglossus zonatus. Replicates were set up for eight weeks during two seasons. Early season feeding resulted in higher almond drop than late season, and L. zonatus resulted in greater drop than L. clypealis. The almond hull width of the four varieties in the study did not influence susceptibility to feeding damage. The final damage assessment at harvest found significant levels of kernel strikes, kernel necrosis, and shriveled almonds in bug feeding cages, with higher levels attributed to L. zonatus than L. clypealis. Further research is warranted to develop an Integrated Pest Management program with reduced risk controls for L. zonatus
The Impact of "Deregulation" on Regulator Behavior: An Empirical Analysis of the Telecommunications Act of 1996
This paper examines how regulators set local prices in response to the changes brought on by the Telecommunications Act of 1996 (âTelecom Actâ). We are particularly interested in the extent to which state regulators set prices that promoted efficiency or were influenced by private-interest groups who had secured rents under a regime of regulated monopoly. Using regional Bell operating company (RBOC) data, our empirical results indicate that private interests continue to influence the structure of retail and wholesale prices, although their influence appears to be waning. We find that changes to the regulatory structure, as measured by federal approval of RBOC Section 271 applications that open up markets to competition and universal service subsidies, resulted in a re-balancing of retail prices and lower overall price levels.competition, political contributions, private interest, public interest, regulation, telecommunications, universal service
Persistent current formation in a high-temperature Bose-Einstein condensate: an experimental test for c-field theory
Experimental stirring of a toroidally trapped Bose-Einstein condensate at
high temperature generates a disordered array of quantum vortices that decays
via thermal dissipation to form a macroscopic persistent current [T. W. Neely
em et al. arXiv:1204.1102 (2012)]. We perform 3D numerical simulations of the
experimental sequence within the Stochastic Projected Gross-Pitaevskii equation
using ab initio determined reservoir parameters. We find that both damping and
noise are essential for describing the dynamics of the high-temperature Bose
field. The theory gives a quantitative account of the formation of a persistent
current, with no fitted parameters.Comment: v2: 7 pages, 3 figures, new experimental data and numerical
simulation
Estimation and optimal designing under latent variable models for paired comparisons studies via a multiplicative algorithm
We consider:<BR/>
1. The problem of estimating the parameters of latent variable models such as the Bradley Terry or Thurstone Model by the method of maximum likelihood, given data from a paired comparisons experiment. The parameters of these models can be taken to be weights which are positive and sum to one;<BR/>
2. The problem of determining approximate locally optimal designs for good estimation of these parameters; i.e of determining optimal design weights which are also positive and sum to one
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