9,776 research outputs found
Quantum Geometry Phenomenology: Angle and Semiclassical States
The phenomenology for the deep spatial geometry of loop quantum gravity is
discussed. In the context of a simple model of an atom of space, it is shown
how purely combinatorial structures can affect observations. The angle operator
is used to develop a model of angular corrections to local, continuum
flat-space 3-geometries. The physical effects involve neither breaking of local
Lorentz invariance nor Planck scale suppression, but rather reply on only the
combinatorics of SU(2) recouping theory. Bhabha scattering is discussed as an
example of how the effects might be observationally accessible.Comment: 5 pages, slightly extended version of the contribution to the
Loops'11 conference proceeding
Regulation of network industries in the European Union and in Central and Eastern Europe
Cost-based pricing has dominated the regulatory regime of network industries - and first of all, the regulation of the infocommunications sector - in the European Union since the early 1990s. When privatization of network industries began in Central and Eastern Europe (CEE), one of the main stumbling blocks on the road toward privately owned telecomm companies and postal services, energy producers and distributors, and other network industries was the lack of efficient and up-to-date industry regulations. From the mid-1990s, accessing countries that later became members of the EU, and other CEE countries that are still waiting for admission swiftly adopted the regulatory framework of the European Union. The EU has been striving for market opening and liberalization in these industries; it abolished industry regulation in several segments of the market of network industries. Now it applies so-called cost-based pricing in areas where regulation is still in place. CEE countries now use the same type of regulation as the advanced member states of the EU. But the regulatory capacity of most CEE countries is still far behind of their West European counterparts. Experts of network industries advocate, and telecommunications, energy and other market regulators in various parts of the world practice, cost-based pricing for inter-firm network access services. Cost-based pricing is carried out under the assumption that the regulator has perfect information regarding the costs of producing the services. We show in this paper that - under fairly general conditions - cost-based pricing creates incentives for regulated firms not to improve their efficiency. We also show that cost-based pricing results in smaller consumer welfare than incentive regulation that takes into account the existence of information asymmetry between the regulator and the firm. A model of interconnection with adverse selection and moral hazard is presented. --network industries,regulation,incentive contracts
Management accounting change in the Portuguese telecommunications industry
This paper sought to study the reasons that explain why has a telecommunications operator (called Marconi) changed its traditional management accounting systems (MAS) and replaced it with activity-based costing (ABC). The paper relied on qualitative data collected through a longitudinal and in-depth case study in the telecommunications sector. The investigation was informed by new institutional sociology (NIS) insights. The study evidenced that Marconi adopted ABC in order to fulfil its constituencies’ expectations of efficiency created with the reorganisation of the Portuguese telecommunications sector and the introduction of competition in the market. Furthermore, the paper contests the managerial emphasis that ABC has been subject to and claims that social accounting theories, such as institutionalism, should be adopted by management accounting researchers in order to achieve a deeper understanding of the ‘ABC phenomenon’
The three-dimensional carrier-envelope-phase map of focused few-cycle pulsed Gaussian beams
We derive an analytical expression that describes the complete
three-dimensional carrier-envelope phase (CEP) distribution of in the focal
volume of ultrashort pulsed Gaussian beams focused by spherical mirrors or
lenses. The focal CEP map depends on the so-called factor specifying the
frequency-dependence of the beam width of the source few-cycle pulse, on its
chirp and on the small chromatic aberration introduced by a lens without
appreciably distorting or broadening the few-cycle pulse. We show how to tailor
the CEP map of mirror-focused and lens-focused few-cycle pulses in order to
produce negligible transversal and axial CEP variations in specific regions of
the focal volume for phase-sensitive interactions of light with matter taking
place in a volume or on a surface. We propose a quasi-achromatic doublet lens
that can implement in practice these tailored CEP distributions.Comment: 9 pages, 6 figure
Spin-triplet paired phases inside ferromagnet induced by Hund's rule coupling and electronic correlations: Application to
We discuss a mechanism of real-space spin-triplet pairing, alternative to
that due to quantum paramagnon excitations, and demonstrate its applicability
to . Both the Hund's rule ferromagnetic exchange and
inter-electronic correlations contribute to the same extent to the equal-spin
pairing, particularly in the regime in which the weak-coupling solution does
not provide any. The theoretical results, obtained within the
orbitally-degenerate Anderson lattice model, match excellently the observed
phase diagram for with the coexistent ferromagnetic (FM1) and
superconducting (-type) phase. Additionally, weak - and -type
paired phases appear in very narrow regions near the metamaganetic (FM2
FM1) and FM1 paramagnetic first-order
phase-transition borders, respectively. The values of magnetic moments in the
FM2 and FM1 states are also reproduced correctly in a semiquantitative manner.
The Hund's metal regime is also singled out as appearing near FM1-FM2 boundary
A sock for foot-drop: A preliminary study on two chronic stroke patients
Background: Foot-drop is a common motor impairment of chronic stroke patients, which may be addressed with an ankle foot orthosis. Although there is reasonable evidence of effectiveness for ankle foot orthoses, user compliance is sometimes poor. This study investigated a new alternative to the ankle foot orthosis, the dorsiflex sock.
Case description and methods: The dorsiflex sock was evaluated using an A-B single case experimental design. Two community-dwelling, chronic stroke patients with foot-drop participated in this study. Measures were selected to span the International Classification of Function, Disability and Health domains and user views on the dorsiflex sock were also collected.
Findings and outcomes: The dorsiflex sock was not effective in improving participants’ walking symmetry, speed or energy expenditure. Participant 1 showed improvement in the distance he could walk in 6 min when using the dorsiflex sock, but this was in keeping with a general improvement trend over the course of this study. However, both participants viewed the dorsiflex sock positively and reported a positive effect on their walking.
Conclusion: Despite positive user perceptions, the study found no clear evidence that dorsiflex sock is effective in improving foot-drop.
Clinical relevance Although the dorsiflex sock offers an attractive alternative to an ankle foot orthosis, the case studies found no clear evidence of its efficacy. Clinicians should view this device with caution until further research becomes availabl
Effects of Cone Tip Changes On Wall-Cooled Hypersonic Boundary Layer Transition and Turbulence
Boundary layer measurements took place at Air Force Research Lab’s (AFRL) Mach-6 Ludwieg tube hypersonic wind tunnel on a 7-degree half angle spherically blunted nose cone with a 1.5 mm radius to study the effects of a cooled surface on the transition process. Experiments compared uncooled and cooled flow conditions on the blunt-nosed model, and then compared to past data for a sharp-tipped cone of similar geometry. Cooling the surface delayed the onset of transition on the blunt nose model. Combining the effects of nose blunting and cooling further increased transition delay than each acting individually compared to the sharp-tipped case. This outcome provides much needed data in an area of study with inconclusive results
Strategies to Reduce Voluntary Employee Turnover in Small Business
Increasing turnover rates are costly to businesses, causing problems with workloads and workflow. The annual resignation rate in the United States has approached 25%, which small business owners cannot afford. Guided by the Herzberg 2-factor theory, the purpose of this descriptive case study was to explore what strategies some small business owners have used to reduce voluntary employee turnover in the United States. Data saturation was achieved after conducting semistructured interviews and document reviews with 4 small business owners in southeast North Carolina who have been in business for at least 5 years and have not experienced any voluntary employee resignations within the past year. Data interpretations from the interview data were derived via an inductive analytic coding process; these interpretations were then triangulated with emergent themes derived from small business owners\u27 policies, procedures, and personnel manuals. Participants noted the need for training, equitable employee compensation, a professional work environment, and open effective communication as the top contributing factors to reducing voluntary employee turnover. The small business owners indicated the use of professionalism contributes to a positive work environment and recognized education as a factor of voluntary employee turnover. Social implications include the potential to decrease voluntary employee turnover in small businesses, thus contributing to the retention of skilled employees, reducing unemployment, and decreasing revenue losses
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