1,161 research outputs found
Users and accounting information preferences of government department financial reports
The introduction of an accounting standard requiring government departments to replace fund-type, cash-based accounting statements with business-type, accrual based accounting statements has led to criticism that business-type, general purpose financial statements do not take account of the information requirements of major users. Such criticism echoes a long standing debate in which the users of public sector financial statements and their informational requirements are analysed in competing models. One view suggests that there are many users with homogeneous informational needs, who can be classified into a few broad groups. The other view maintains that there are few users who have differential informational requirements. This research adds to the few empirical studies on the usefulness of public sector accounting statement information. The purpose of this research is to test the hypothesis that users perceive that there is no difference in the usefulness of fund-type, cash-based; business-type, accrual-based accounting statements, and both cash and accrual combined accounting statements. Responses from legislators, citizen/ interest group members, and preparers to a questionnaire provides the data for statistical analysis. Test results suggest that there is only moderate support for the hypothesis that heterogenous users have different information needs. Strong support is found for the hypothesis that combined sets of statements as opposed to cash, or accrual are more useful. This conclusion holds for both the importance and useability dimensions of the construct perceived usefulness
An experimental investigation of the laminar horseshoe vortex around an emerging obstacle
An emerging long obstacle placed in a boundary layer developing under a
free-surface generates a complex horseshoe vortex (HSV) system, which is
composed of a set of vortices exhibiting a rich variety of dynamics.
The present experimental study examines such flow structure and characterizes
precisely, using PIV measurements, the evolution of the HSV geometrical and
dynamical properties over a wide range of dimensionless parameters (Reynolds
number , boundary layer development ratio and obstacle aspect ratio ).
The dynamical study of the HSV is based on the categorization of the HSV
vortices motion into an enhanced specific bi-dimensional typology, separating a
coherent (due to vortex-vortex interactions) and an irregular evolution (due to
appearance of small-scale instabilities).
This precise categorization is made possible thanks to the use of vortex
tracking methods applied on PIV measurements,
A semi-empirical model for the HSV vortices motion is then proposed to
highlight some important mechanisms of the HSV dynamics, as (i) the influence
of the surrounding vortices on a vortex motion and (ii) the presence of a phase
shift between the motion of all vortices.
The study of the HSV geometrical properties (vortex position and
characteristic lengths and frequencies) evolution with the flow parameters
shows that strong dependencies exist between the streamwise extension of the
HSV and the obstacle width, and between the HSV vortex number and its
elongation.
Comparison of these data with prior studies for immersed obstacles reveals
that emerging obstacles lead to greater adverse pressure gradients and
down-flows in front of the obstacle
Production delays, supply distortions and endogenous price dynamics
It takes time to produce commodities, and different production technologies may take different lengths of time. Suppose that firms may switch between different production technologies that take different lengths of time. A natural implication of such a scenario is that not all firms would then offer their commodities in every period, i.e. firms’ total
supply schedule would become a time-varying quantity. Based on a behavioral cobweb framework, we analytically demonstrate that commodity markets become unstable when firms switch too rapidly between production technologies that take different lengths of time. In particular, we observe that supply distortions lead to endogenous
commodity price dynamics due to a mismatch between supply and demand
The effect of uniaxial pressure on the magnetic anomalies of the heavy-fermion metamagnet CeRu2Si2
The effect of uniaxial pressure (P_u) on the magnetic susceptibility (X),
magnetization (M), and magnetoresistance (MR) of the heavy-fermion metamagnet
CeRu2Si2 has been investigated. For the magnetic field along the tetragonal c
axis, it is found that characteristic physical quantities, i.e., the
temperature of the susceptibility maximum (T_max), the pagamagnetic Weiss
temperature (Q_p), 1/X at 2 K, and the magnetic field of the metamagnetic
anomaly (H_M), scale approximately linearly with P_u, indicating that all the
quantities are related to the same energy scale, probably of the Kondo
temperature. The increase (decrease) of the quantities for P_u || c axis (P_u
|| a axis) can be attributed to a decrease (increase) in the nearest Ce-Ru
distance. Consistently in MR and X, we observed a sign that the anisotropic
nature of the hybridization, which is believed to play an important role in the
metamagnetic anomaly, can be controlled by applying the uniaxial pressure.
PACS numbers: 75.20.Hr, 71.27.+a, 74.62.FjComment: 7 pages, ReVTeX, 6 EPS figures : Will appear in Phys. Rev.
Spontaneous deformation of the Fermi surface due to strong correlation in the two-dimensional t-J model
Fermi surface of the two-dimensional t-J model is studied using the
variational Monte Carlo method. We study the Gutzwiller projected d-wave
superconducting state with an additional variational parameter t'_v
corresponding to the next-nearest neighbor hopping term. It is found that the
finite t'_v<0 gives the lowest variational energy in the wide range of
hole-doping rates. The obtained momentum distribution function shows that the
Fermi surface deforms spontaneously. It is also shown that the van Hove
singularity is always located very close to the Fermi energy. Using the
Gutzwiller approximation, we show that this spontaneous deformation is due to
the Gutzwiller projection operator or the strong correlation.Comment: 4 pages, 3 eps figures, revte
Glacial climate sensitivity to different states of the Atlantic Meridional Overturning Circulation: results from the IPSL model
Paleorecords from distant locations on the globe show rapid and large amplitude climate variations during the last glacial period. Here we study the global climatic response to different states of the Atlantic Meridional Overturning Circulation (AMOC) as a potential explanation for these climate variations and their possible connections. We analyse three glacial simulations obtained with an atmosphere-ocean coupled general circulation model and characterised by different AMOC strengths (18, 15 and 2 Sv) resulting from successive ~0.1 Sv freshwater perturbations in the North Atlantic. These AMOC states suggest the existence of a freshwater threshold for which the AMOC collapses. A weak (18 to 15 Sv) AMOC decrease results in a North Atlantic and European cooling. This cooling is not homogeneous, with even a slight warming over the Norwegian Sea. Convection in this area is active in both experiments, but surprisingly stronger in the 15 Sv simulation, which appears to be related to interactions with the atmospheric circulation and sea-ice cover. Far from the North Atlantic, the climatic response is not significant. The climate differences for an AMOC collapse (15 to 2 Sv) are much larger and of global extent. The timing of the climate response to this AMOC collapse suggests teleconnection mechanisms. Our analyses focus on the North Atlantic and surrounding regions, the tropical Atlantic and the Indian monsoon region. The North Atlantic cooling associated with the AMOC collapse induces a cyclonic atmospheric circulation anomaly centred over this region, which modulates the eastward advection of cold air over the Eurasian continent. This can explain why the cooling is not as strong over western Europe as over the North Atlantic. In the Tropics, the southward shift of the Inter-Tropical Convergence Zone appears to be strongest over the Atlantic and Eastern Pacific and results from an adjustment of the atmospheric and oceanic heat transports. Finally, the Indian monsoon weakening appears to be connected to the North Atlantic cooling via that of the troposphere over Eurasia. Such an understanding of these teleconnections and their timing could be useful for paleodata interpretation
Acoustic stimulation time-locked to the beginning of sleep apnea events reduces oxygen desaturations: a pilot-study.
We aimed to determine whether bone-conducted acoustic stimulation could prematurely terminate sleep apnea events, thereby decreasing amplitude and duration of subsequent oxygen desaturation. As oxygen desaturation has been linked to cardiovascular consequences, we postulate this could be a viable therapy in some cases.
Eight patients with severe Obstructive Sleep Apnea (2 women, 45 [20-68] y.o. Apnea-Hypopnea Index: 77.7 ± 22.3/h) underwent polysomnography at the Lausanne University Sleep Center. Short acoustic stimulations were administered by bone conduction every second event of sleep apnea. Sounds were remotely administered using a Dreem® headband worn by patients while undergoing nocturnal polysomnography. Amplitude (%) and duration(s) of oxygen desaturations following terminated apneas were compared to that of non-stimulated previous and subsequent events.
549 stimulations (68.6 ± 38 sounds per patient) in N1 (16.2%), N2 (69.9%), N3 (4.2%), and REM(9.6%) were conducted. Compared to the previous and subsequent non-stimulated apnea, stimulations reduced event duration by 21.4% (-3.4 ± 7.2 s, p < 0.0001) while oxygen desaturation amplitude and duration were reduced by 30.4% (mean absolute difference ± SD: -1.9 ± 2.8%, p < 0.0001), and 39.6% (-5.7 ± 9.2 s, p < 0.0001) respectively. For these variables, each patient showed a significant improvement following acoustic stimulation. Sound-associated discomfort was rated 1.14 ± 1.53 on an 8 points scale (8 = worst) and only 6.8% of emitted sounds were perceived by the patients, suggesting a well-tolerated intervention.
Bone-conducted sound stimuli decreased apnea events duration as well as duration and amplitude of associated oxygen desaturations. Stimulations were well tolerated and rarely perceived by patients. This therapeutic approach deserves further investigation, with monitoring of effects on sleep quality, daytime function/sleepiness and cardiovascular parameters
Pressure Evolution of the Magnetic Field induced Ferromagnetic Fluctuation through the Pseudo-Metamagnetism of CeRu2Si2
Resistivity measurements performed under pressure in the paramagnetic ground
state of CeRu2Si2 are reported. They demonstrate that the relative change of
effective mass through the pseudo metamagnetic transition is invariant under
pressure. The results are compared with the first order metamagnetic transition
due to the antiferromagnetism of Ce0.9La0.1Ru2Si2 which corresponds to the
"negative" pressure of CeRu2Si2 by volume expansion. Finally, we describe the
link between the spin-depairing of quasiparticles on CeRu2Si2 and that of
Cooper pairs on the unconventional heavy fermion superconductor CeCoIn5.Comment: 5 pages, 6 figures, accepted for publication in J. Phys. Soc. Jp
- …