Price formation, nominal anchors, and stabilization policies in Hungary : an empirical analysis

The authors empirically explore the inflationary process in Hungary. Using monthly data, they provide econometric estimates of the determinants of inflation for 1990-92. Empirical estimates of price equations - both consumer price index (CPI) and producer price index (PPI) - show the exchange rate's quantitative importance and statistical significance in price formation in Hungary during the period of intensified reform as the economy became more open to international trade in both inputs and final goods. Their estimates show that the money supply affects consumer and producer prices with several lags; its impact on prices is small in the short run. Nominal wages have a more significant effect on the CPI than on the PPI. The authors present policy simulations of alternative rules for the exchange rate and the money supply and their effect on the rate of inflation and the level of the real exchange rate. They find that a rule of fixing the exchange rate entails a lower level of CPI inflation - 5 percentage points less of CPI inflation a year - than if the rule is based only on reducing the rate of money growth (to 1 percent a month). But a fixed exchange rate policy is associated with greater appreciation of the real exchange rate than is the policy of money-based disinflation - nearly 4 percentage points more real appreciation a year. A PPI-based exchange rate rule stabilizes the real exchange rate at the cost of a substantial acceleration in inflation. These exercises illustate the nature and magnitude of the tradeoffs between faster disinflation and the level of external competitiveness in an open economy such as Hungary that uses the exchange rate as a nominal anchor in disinflation.Economic Theory&Research,Environmental Economics&Policies,Economic Stabilization,Macroeconomic Management,Markets and Market Access

A new model of the upper mantle structure beneath the western rim of the East European Craton

We present a new 1-D <i>P</i> wave seismic velocity model (called MP1-SUW) of the upper mantle structure beneath the western rim of the East European Craton (EEC) based on the analysis of the earthquakes recorded at the Suwałki (SUW) seismic station located in NE Poland which belongs to the Polish Seismological Network (PLSN). Motivation for this study arises from the observation of a group of reflected waves after expected <i>P</i>₄₁₀P at epicentral distances 2300–2800 km from the SUW station. Although the existing global models represent the first-arrival traveltimes, they do not represent the full wavefield with all reflected waves because they do not take into account the structural features occurring regionally such as 300 km discontinuity. We perform <i>P</i> wave traveltime analysis using 1-D and 2-D forward ray-tracing modelling for the distances of up to 3000 km. We analysed 249 natural seismic events from four azimuthal spans with epicentres in the western Mediterranean Sea region (WMSR), the Greece and Turkey region (GTR), the Caucasus region (CR) and the part of the northern Mid-Atlantic Ridge near the Jan Mayen Island (JMR). For all chosen regions, except the JMR group for which 2-D modelling was performed, we estimate a 1-D average velocity model which will characterize the main seismic discontinuities. It appears that a single 1-D model (MP1-SUW model) explains well the observed traveltimes for the analysed groups of events. Differences resulting from the different azimuth range of earthquakes are close to the assumed picking uncertainty. The MP1-SUW model documents the bottom of the asthenospheric low-velocity zone (LVZ) at the depth of 220 km, 335 km discontinuity and the zone with the reduction of <i>P</i> wave velocity atop 410 km discontinuity which is depressed to 440 km depth. The nature of the regionally occurring 300 km boundary is explained here by tracing the ancient subduction regime related to the closure of the Iapetus Ocean, the Rheic Ocean and the Tornquist Sea

OH Radical Imaging in a DI Diesel Engine and the Structure of the Early Diffusion Flame

Laser-sheet imaging studies have considerably advanced our understanding of diesel combustion; however, the location and nature of the flame zones within the combusting fuel jet have been largely unstudied. To address this issue, planar laser-induced fluorescence (PLIF) imaging of the OH radical has been applied to the reacting fuel jet of a direct-injection diesel engine of the ``heavy-duty`` size class, modified for optical access. An Nd:YAG-based laser system was used to pump the overlapping Q{sub 1}9 and Q{sub 2}8 lines of the (1,0) band of the A{yields}X transition at 284.01 nm, while the fluorescent emission from both the (0,O) and (1, I) bands (308 to 320 nm) was imaged with an intensified video camera. This scheme allowed rejection of elastically scattered laser light, PAH fluorescence, and laser-induced incandescence. OH PLIF is shown to be an excellent diagnostic for diesel diffusion flames. The signal is strong, and it is confined to a narrow region about the flame front because the threebody recombination reactions that reduce high flame-front OH concentrations to equilibrium levels occur rapidly at diesel pressures. No signal was evident in the fuel-rich premixed flame regions where calculations and burner experiments indicate that OH concentrations will be below detectable limits. Temporal sequences of OH PLIF images are presented showing the onset and development of the early diffusion flame up to the time that soot obscures the images. These images show that the diffusion flame develops around the periphery of the-downstream portion of the reacting fuel jet about half way through the premixed burn spike. Although affected by turbulence, the diffusion flame remains at the jet periphery for the rest of the imaged sequence

Time-resolved gas temperatures in the oscillating turbulent flow of a pulse combustor tail pipe

The cyclic behavior of the gas temperature in the oscillating turbulent flow in a pulse combustor tail pipe was studied using two-line atomic fluorescence. In this flow, the oscillations result from an acoustic resonance, and have amplitudes of up to 5 times the mean velocity. Oscillation frequencies were varied from 67 to 101 Hz. Spatially resolved temperature measurements were made to within 400 [mu]m of the wall, providing cycle-resolved profiles of the temperature and the random temperature fluctuations. The combustor-cycle phase relationships among the gas temperature, random-temperature-fluctuation intensity, velocity, and combustion chamber pressure, are compared. Velocity field effects dominated the cyclic behavior of the gas temperature, over the effects of isentropic compressive heating and the convection of hot pockets of gas from the combustion chamber. Cycle-resolved profiles show the gas temperature to be constant across the tail pipe, except for a boundary layer region, at all times during the cycle. Although cyclic temperature oscillations of more than 200 K were observed, the thermal boundary layer was well developed at all times during the cycle. The gas temperature was greater than the wall temperature at all cycle times, unlike the reversing velocity field, indicating that Reynolds analogy between momentum and thermal transport is not valid in this flow. Time-resolved wall heat flux was also measured and its fundamental oscillation is found to be in phase with that of the gas temperature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28549/1/0000348.pd

Stochastics theory of log-periodic patterns

We introduce an analytical model based on birth-death clustering processes to help understanding the empirical log-periodic corrections to power-law scaling and the finite-time singularity as reported in several domains including rupture, earthquakes, world population and financial systems. In our stochastics theory log-periodicities are a consequence of transient clusters induced by an entropy-like term that may reflect the amount of cooperative information carried by the state of a large system of different species. The clustering completion rates for the system are assumed to be given by a simple linear death process. The singularity at t_{o} is derived in terms of birth-death clustering coefficients.Comment: LaTeX, 1 ps figure - To appear J. Phys. A: Math & Ge

Time-resolved velocities and turbulence in the oscillating flow of a pulse combustor tail pipe

The cyclic behavior of the oscillating velocity field in the tail pipe of a pulse combustor was studied using laser doppler velocimetry. In this flow, the oscillations result from an acoustic resonance and have amplitudes of up to 5 times the mean velocity. Oscillation frequencies were varied from 67 to 101 Hz. Streamwise velocity and turbulence-intensity boundary layer profiles were measured to within 130 [mu]m of the wall, and transverse turbulence measurements were made to within 2 mm. The phase relationships of the velocity, turbulence intensity, and combustion chamber pressure oscillations are compared. Velocity oscillations near the wall are found to phase lead those in the center of the pipe, creating periodic flow reversals through the boundary layer. A comparison is made between this turbulent oscillating boundary layer and the laminar oscillating boundary layer for flow over a flat plate. The effects of axial position, pulsation frequency, pulsation amplitude, and mean flow rate on the velocity and turbulence profiles are discussed. Time-resolved wall shear stresses (directly calculated from the velocity measurements) are presented and compared with those of steady turbulent flow. Time-averaged velocity and turbulence profiles are also compared with those of conventional steady turbulent flows. The time-averaged velocity profile is found to be flatter than that of steady flow at the same mean Reynolds number, and both the streamwise and transverse turbulence intensities are found to be significantly higher than those of steady flow.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29484/1/0000570.pd

Heat transfer enhancement in the oscillating turbulent flow of a pulse combustor tail pipe

Heat transfer rates in pulse combustor tail pipes and in other reversing, oscillating, turbulent flows have been found to be much higher than those of steady turbulent flow. To elucidate the mechanisms of the enhancement, the temperature and velocity fields, measured with two-line atomic fluorescence (TLAF) and laser Doppier velocimetry (LDV), respectively, are compared. Time-resolved wall heat fluxes and Nusselt numbers are also presented and discussed. Possible causes for the heat transfer enhancement in oscillating flows are reviewed and discussed in view of the data presented in this paper and the recent literature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29892/1/0000246.pd

Valosin-Containing Protein (VCP) Disease and Familial Alzheimer’s Disease: Contrasts and Overlaps

Introduction Contrasts between two entities may be illuminating because of the emphasis on what each is not. Here we describe two proteinopathies producing brain neurodegeneration in mature adults, autosomal dominant valosin-containing protein (VCP) disease and Familial Alzheimer’s disease (FAD) caused by presenillin-1 (PSEN1) mutations, illustrating both contrasting patterns of clinical presentation and known neuropathologic and imaging features, and points of congruence

Evaluation of three 3ABC ELISAs for foot-and-mouth disease non-structural antibodies using latent class analysis

BACKGROUND: Foot-and-mouth disease (FMD) is a highly contagious viral disease of even-toed ungulates. Serological diagnosis/surveillance of FMD presents several problems as there are seven serotypes worldwide and in the event of vaccination it may be necessary to be able to identify FMD infected/exposed animals irrespective of their vaccination status. The recent development of non-structural 3ABC protein (NSP) ELISA tests has greatly advanced sero-diagnosis/surveillance as these tests detect exposure to live virus for any of the seven serotypes of FMD, even in vaccinated populations. This paper analyses the performance of three NSP tests using a Bayesian formulation of the Hui-Walter latent class model to estimate test sensitivity and specificity in the absence of a "gold-standard" test, using sera from a well described cattle population in Cameroon with endemic FMD. RESULTS: The analysis found a high sensitivity and specificity for both the Danish C-ELISA and the World Organisation for Animal Health (O.I.E.) recommended South American I-ELISA. However, the commercial CHEKIT kit, though having high specificity, has very low sensitivity. The results of the study suggests that for NSP ELISAs, latent class models are a useful alternative to the traditional approach of evaluating diagnostic tests against a known "gold-standard" test as imperfections in the "gold-standard" may give biased test characteristics. CONCLUSION: This study demonstrates that when applied to naturally infected zebu cattle managed under extensive rangeland conditions, the FMD ELISAs may not give the same parameter estimates as those generated from experimental studies. The Bayesian approach allows for full posterior probabilities and capture of the uncertainty in the estimates. The implications of an imperfect specificity are important for the design and interpretation of sero-surveillance data and may result in excessive numbers of false positives in low prevalence situations unless a follow-up confirmatory test such as the enzyme linked immunoelectrotransfer blot (EITB) is used