2,288 research outputs found
Gauge Independence and Relativistic Electron Dispersion Equation in Dense Media
We discuss the gauge parameter dependence of particle spectra in statistical
quantum electrodynamics and conclude that the electron spectrum is
gauge-parameter dependent. The physical spectrum being obtained in the Landau
gauge, which leads to gauge invariance in a restricted class of gauge
transformations.Comment: Style corrections 16 pages, three figures, RevTe
On the Significance of the Quantity "A Squared"
We consider the gauge potential A and argue that the minimum value of the
volume integral of A squared (in Euclidean space) may have physical meaning,
particularly in connection with the existence of topological structures. A
lattice simulation comparing compact and non-compact ``photodynamics'' shows a
jump in this quantity at the phase transition, supporting this idea.Comment: 6 pages, one figur
Entrepreneurship Education’s Impact on Entrepreneurial Intention: A Predictive Regression Model of Chinese University Students
“Entrepreneurship education’s impact on entrepreneurial intention: A predictive regression model of Chinese university students” is a dissertation study by Brian A. Lavelle, doctoral candidate at George Fox University. The study investigates the impact of entrepreneurship education on entrepreneurial intention using quantitative methods and survey data from China. The study uses Ajzen’s (1991) Theory of Planned Behavior and the Entrepreneurial Intention Questionnaire (Linan & Chen, 2009) to investigate the impact between personal attitude, subjective norms, perceived behavioral control, and entrepreneurship education on entrepreneurial intention. The data was collected from eleven college and university programs in Wuxi, Jiangsu Province, in the People’s Republic of China. The primary methodology of the study was regression analysis which allowed the researcher to assess the individual impact of each antecedent factor in the regression model. The findings of the study provide no evidence that entrepreneurship education positively impacts entrepreneurial intention in China. The author concludes that the self-selection bias and differences between ranked universities and vocational colleges in China may explain the results of the study. This research provides findings with implications to university communities and policy-makers in China, which may serve as a performance measurement of entrepreneurship education policies. This research provides findings with implications to scholars as the entrepreneurship education-entrepreneurial relationship in China is currently inconclusive
Concurrent optimization of airframe and engine design parameters
An integrated system for the multidisciplinary analysis and optimization of airframe and propulsion design parameters is being developed. This system is known as IPAS, the Integrated Propulsion/Airframe Analysis System. The traditional method of analysis is one in which the propulsion system analysis is loosely coupled to the overall mission performance analysis. This results in a time consuming iterative process. First, the engine is designed and analyzed. Then, the results from this analysis are used in a mission analysis to determine the overall aircraft performance. The results from the mission analysis are used as a guide as the engine is redesigned and the entire process repeated. In IPAS, the propulsion system, airframe, and mission are closely coupled. The propulsion system analysis code is directly integrated into the mission analysis code. This allows the propulsion design parameters to be optimized along with the airframe and mission design parameters, significantly reducing the time required to obtain an optimized solution
Quantumness in decoherent quantum walk using measurement-induced disturbance
The classicalization of a decoherent discrete-time quantum walk on a line or
an n-cycle can be demonstrated in various ways that do not necessarily provide
a geometry-independent description. For example, the position probability
distribution becomes increasingly Gaussian, with a concomitant fall in the
standard deviation, in the former case, but not in the latter. As another
example, each step of the quantum walk on a line may be subjected to an
arbitrary phase gate, without affecting the position probability distribution,
no matter whether the walk is noiseless or noisy. This symmetry, which is
absent in the case of noiseless cyclic walk, but is restored in the presence of
sufficient noise, serves as an indicator of classicalization, but only in the
cyclic case. Here we show that the degree of quantum correlations between the
coin and position degrees of freedom, quantified by a measure based on the
disturbance induced by local measurements (Luo, Phys. Rev. A 77, 022301
(2008)), provides a suitable measure of classicalization across both type of
walks. Applying this measure to compare the two walks, we find that cyclic
quantum walks tend to classicalize faster than quantum walks on a line because
of more efficient phase randomization due to the self-interference of the two
counter-rotating waves. We model noise as acting on the coin, and given by the
squeezed generalized amplitude damping (SGAD) channel, which generalizes the
generalized amplitude damping channel.Comment: 8 pages with 8 figures, Published versio
Recommended from our members
Threats to safe transitions from hospital to home: a consensus study in North West London primary care.
BACKGROUND: Transitions between healthcare settings are vulnerable points for patients. AIM: To identify key threats to safe patient transitions from hospital to primary care settings. DESIGN AND SETTING: Three-round web-based Delphi consensus process among clinical and non-clinical staff from 39 primary care practices in North West London, England. METHOD: Round 1 was a free-text idea-generating round. Rounds 2 and 3 were consensus-obtaining rating rounds. Practices were encouraged to complete the questionnaires at team meetings. Aggregate ratings of perceived level of importance for each threat were calculated (1-3: 'not important', 4-6: 'somewhat important', 7-9: 'very important'). Percentage of votes cast for each patient or medication group were recorded; consensus was defined as ≥75%. RESULTS: A total of 39 practices completed round 1, 36/39 (92%) completed round 2, and 30/36 (83%) completed round 3. Round 1 identified nine threats encompassing problems involving communication, service organisation, medication provision, and patients who were most at risk. 'Poor quality of handover instructions from secondary to primary care teams' achieved the highest rating (mean rating at round 3 = 8.43) and a 100% consensus that it was a 'very important' threat. Older individuals (97%) and patients with complex medical problems taking >5 medications (80%) were voted the most vulnerable. Anticoagulants (77%) were considered to pose the greatest risk to patients. CONCLUSION: This study identified specific threats to safe patient transitions from hospital to primary care, providing policymakers and healthcare providers with targets for quality improvement strategies. Further work would need to identify factors underpinning these threats so that interventions can be tailored to the relevant behavioural and environmental contexts in which these threats arise
Gluon condensate, quark propagation, and dilepton production in the quark-gluon plasma
A calculation of the thermal quark propagator is presented taking the gluon
condensate above the critical temperature into account. The quark dispersion
relation and the dilepton production following from this propagator are
derived.Comment: 4 pages, LATEX (style file included), 3 PostScript figures, to be
published in the proceedings of the Quark Matter'99 conferenc
- …