On the usefulness of government spending in the EU area

We investigate the effects of fiscal policy on private consumption and investment in the European Union. A certain consensus has aroused that fiscal impulses have expansionary Keynesian effects on the economic activity. However, the existing empirical literature has concentrated on few countries, mostly outside the EU. We check the validity of this result for the EU area, by using annual data and a panel vector auto-regression approach (PVAR). Our results show that increases in public spending lead to positive and significant effects on private consumption and private investment. According to our baseline estimate, a 1% increase in public spending produces a 0.36% on impact rise in private consumption, and a 0.79% impact rise in private investment. The effects are substantial, and die out slowly (faster in the case of private consumption). A further disaggregation between wage and non-wage components reveals different effects. As for the impact on private consumption, our results show that public salaries have a relatively stronger stimulating role, a result which is probably due to the importance of the public sector especially in continental Europe. On the other hand, the positive impact on private investment is mainly due to the non-wage component of government consumption.

Consumption Multipliers of Different Types of Public Spending: a Structural Vector Error Correction Analysis for the UK

The aim of this paper is to investigate the relationship between government spending and private consumption in the UK, for which there is scarce previous empirical evidence. We disaggregate public expenditure into three categories and search for the corresponding private consumption multipliers. Our analysis includes the estimation of a structural vector error correction (SVEC) model, using quarterly non-interpolated data for the period 1981:1 – 2007:4. Initially, we estimate negative effects on consumption of shocks to total public spending. Then, using the spending decomposition, we find that while shocks to public wages crowd-out private consumption as predicted by neoclassical models, shocks to the non-systematic component of social spending and government purchases of goods and services generate a positive reaction, so to crowd-in private consumption. Thus, the qualitative and quantitative dimensions of fiscal multipliers on private consumption change across different public spending categories. Our findings suggest that any empirical support of competing theoretical models on the issue would benefit from a disaggregation of government expenditure, rather than focusing on the aggregate measure

Detection and period measurements of GX1+4 at hard x ray energies with the SIGMA telescope

The galactic Low Mass X ray Binary GX1+4 was detected by the coded aperture hard X ray gamma ray SIGMA telescope during the Feb. to April 1991 observations of the galactic center regions. The source, whose emission varied during the survey of a factor greater than 40 pct., reached a maximum luminosity in the 40 to 140 energy range of 1.03 x 10(exp 37) erg/s (D = 8.5 kpc), thus approaching the emission level of the 1970 to 1980 high state. Two minute flux pulsations were detected on Mar. 22 and on Mar. 31 and Apr. 1. Comparison with the last period measurements shows that the current spin-down phase of GX1+4 is ending. Concerning the proposed association of this source with the galactic center 511 keV annihilation emission, upper limits were derived

Speeding up Simplification of Polygonal Curves using Nested Approximations

We develop a multiresolution approach to the problem of polygonal curve approximation. We show theoretically and experimentally that, if the simplification algorithm A used between any two successive levels of resolution satisfies some conditions, the multiresolution algorithm MR will have a complexity lower than the complexity of A. In particular, we show that if A has a O(N2/K) complexity (the complexity of a reduced search dynamic solution approach), where N and K are respectively the initial and the final number of segments, the complexity of MR is in O(N).We experimentally compare the outcomes of MR with those of the optimal "full search" dynamic programming solution and of classical merge and split approaches. The experimental evaluations confirm the theoretical derivations and show that the proposed approach evaluated on 2D coastal maps either shows a lower complexity or provides polygonal approximations closer to the initial curves.Comment: 12 pages + figure

The Agile Alert System For Gamma-Ray Transients

In recent years, a new generation of space missions offered great opportunities of discovery in high-energy astrophysics. In this article we focus on the scientific operations of the Gamma-Ray Imaging Detector (GRID) onboard the AGILE space mission. The AGILE-GRID, sensitive in the energy range of 30 MeV-30 GeV, has detected many gamma-ray transients of galactic and extragalactic origins. This work presents the AGILE innovative approach to fast gamma-ray transient detection, which is a challenging task and a crucial part of the AGILE scientific program. The goals are to describe: (1) the AGILE Gamma-Ray Alert System, (2) a new algorithm for blind search identification of transients within a short processing time, (3) the AGILE procedure for gamma-ray transient alert management, and (4) the likelihood of ratio tests that are necessary to evaluate the post-trial statistical significance of the results. Special algorithms and an optimized sequence of tasks are necessary to reach our goal. Data are automatically analyzed at every orbital downlink by an alert pipeline operating on different timescales. As proper flux thresholds are exceeded, alerts are automatically generated and sent as SMS messages to cellular telephones, e-mails, and push notifications of an application for smartphones and tablets. These alerts are crosschecked with the results of two pipelines, and a manual analysis is performed. Being a small scientific-class mission, AGILE is characterized by optimization of both scientific analysis and ground-segment resources. The system is capable of generating alerts within two to three hours of a data downlink, an unprecedented reaction time in gamma-ray astrophysics.Comment: 34 pages, 9 figures, 5 table

PRACTICAL DESIGN EXAMPLES FOR HUMAN HABITATS IN SPACE, OFF-GRID, AND IN LOW-IMPACT COMMUNITIES

All human habitat problems fall into three major categories- the environment, the habitat itself, and the occupants. By breaking these problems down into common themes and addressing them directly, we can build a common knowledge base for all three challenges faced by humanity. A crew living in space has the new problems of coping with radiation, microgravity, and vacuum. All the while, they are dealing the usual issues of eating, sleeping, and getting along with the rest of the occupants. By isolating the differences between space and earth habitats, we can create common architectural styles for each human habitat challenge where commonality is appropriate. We can then examine the differences, then isolate and modularize the secondary systems where possible. This simplifies experimentation and testing of the physical and psychological design of a structure on Earth prior to attempting use in space. It also allows spin-off architectures for extreme environments, off-grid settlements, research bases, and low impact communities on Earth. By isolating and testing each attribute of the system in parallel with control groups, we can scientifically refine the systems for human shelter regardless of environment. This paper will show numerous examples of architectures designed for space or space analog research bases. These designs can be both de-scoped to off-grid sustainable architecture, and scoped up for space habitat applications. Concepts such as internal greenhouses, enclosed permaculture, thermal protection, energy management, and radiation shielding are included for both minimal habitats and large bases. These systems can then be applied for disaster first responders, research bases in extreme environments, o-grid homes, and low-impact communities

AGILE detection of a strong gamma-ray flare from the blazar 3C 454.3

We report the first blazar detection by the AGILE satellite. AGILE detected 3C 454.3 during a period of strongly enhanced optical emission in July 2007. AGILE observed the source with a dedicated repointing during the period 2007 July 24-30 with its two co-aligned imagers, the Gamma-Ray Imaging Detector and the hard X-ray imager Super-AGILE sensitive in the 30 MeV-50 GeV and 18-60 keV, respectively. Over the entire period, AGILE detected gamma-ray emission from 3C 454.3 at a significance level of 13.8-$\sigma$ with an average flux (E$>$100 MeV) of $(280 \pm 40) \times 10^{-8}$ photons cm$^{-2}$ s$^{-1}$. The gamma-ray flux appears to be variable towards the end of the observation. No emission was detected by Super-AGILE in the energy range 20-60 keV, with a 3-$\sigma$ upper limit of $2.3 \times 10^{-3}$ photons cm$^{-2}$ s$^{-1}$. The gamma-ray flux level of 3C 454.3 detected by AGILE is the highest ever detected for this quasar and among the most intense gamma-ray fluxes ever detected from Flat Spectrum Radio Quasars.Comment: Accepted by Astrophysical Journal Letters; 14 pages, 3 EPS Figures, 1 Tabl