95,690 research outputs found
Science and Subpoenas: When do the Courts Become Instruments of Manipulation?
Fischer says he believes that the uneasy relationship between law and science is likely to continue regarding disclosure of scientific research materials
Aspects of quark mass generation on a torus
In this talk we report on recent results for the quark propagator on a
compact manifold. The corresponding Dyson-Schwinger equations on a torus are
solved on volumes similar to the ones used in lattice calculations. The
quark-gluon interaction is fixed such that the lattice results are reproduced.
We discuss both the effects in the infinite volume/continuum limit as well as
effects when the volume is small.Comment: 3 pages, 3 figures; talk given by CF at QNP06, Madrid, June 200
European hoarding: currency use among immigrants in Switzerland
Do immigrants have a higher demand for large denominated banknotes than natives? This study examines whether cash orders for CHF 1000 notes, a banknote not used for daily transactions, is concentrated in Swiss cities with a high foreign-to-native ratio. Controlling for a range of socio-economic indicators across 250 Swiss cities, European immigrants in Switzerland are found to hoard less CHF 1000 banknotes than natives. A 1 percent increase in the immigrant-to-native ratio leads to a reduction in currency orders by CHF 4000. This negative correlation between immigrant-to-native ratio and currency orders for CHF 1000 notes holds irrespective of the European immigrants' country of origin. Hoarding of large denominated banknotes by natives is attributed tax avoidance.Money ; Immigrants ; Bank notes ; Monetary policy
On the Inadequacy of Newswire Reports for Empirical Research on Foreign Exchange Interventions
Newswire reports have become an accepted tool for empirical studies analyzing informational asymmetries in FX markets. This paper tests the accuracy of such reports for Swiss interventions in the foreign exchange market. The evidence finds that the time stamp of the reports does not always lie near the recorded time of the first intervention trade as is commonly assumed in market microstructure studies. The standard deviation of the time difference is measured in hours and not in minutes. These and other regression results question the accuracy of newswire reports for Swiss interventions.Central Bank Interventions, Intra-Daily Data, Newswire Reports
Measuring carrier density in parallel conduction layers of quantum Hall systems
An experimental analysis for two parallel conducting layers determines the
full resistivity tensor of the parallel layer, at magnetic fields where the
other layer is in the quantum Hall regime. In heterostructures which exhibit
parallel conduction in the modulation-doped layer, this analysis quantitatively
determines the charge density in the doping layer and can be used to estimate
the mobility. To illustrate one application, experimental data show magnetic
freeze-out of parallel conduction in a modulation doped heterojunction. As
another example, the carrier density of a minimally populated second subband in
a two-subband quantum well is determined. A simple formula is derived that can
estimate the carrier density in a highly resistive parallel layer from a single
Hall measurement of the total system.Comment: 7 pages, 7 figure
REGIONS, TECHNOLOGICAL INTERDEPENDENCE AND GROWTH IN EUROPE
This paper presents a theoretical neoclassical growth model with two kinds of capital, and technological interdependence among regions. Technological interdependence is assumed to operate through spatial externalities caused by disembodied knowledge diffusion between technologically similar regions. The transition from theory to econometrics yields a reduced-form empirical model that in the spatial econometrics literature is known as spatial Durbin model. Technological dependence between regions is formulated by a connectivity matrix that measures closeness of regions in a technological space spanned by 120 distinct technological fields. We use a system of 158 regions across 14 European countries over the period from 1995 to 2004 to empirically test the model. The paper illustrates the importance of an impact-based model interpretation, in terms of the LeSage and Pace (2009) approach, to correctly quantify the magnitude of spillover effects that avoid incorrect inferences about the presence or absence of significant capital externalities among technologically similar regions.Economic growth, augmented Mankiw-Romer-Weil model, disembodied knowledge diffusion, technological similarity between regions, spatial econometrics, European regions
GIS and Network Analysis
Both geographic information systems (GIS) and network analysis are burgeoning fields, characterised by rapid methodological and scientific advances in recent years. A geographic information system (GIS) is a digital computer application designed for the capture, storage, manipulation, analysis and display of geographic information. Geographic location is the element that distinguishes geographic information from all other types of information. Without location, data are termed to be non-spatial and would have little value within a GIS. Location is, thus, the basis for many benefits of GIS: the ability to map, the ability to measure distances and the ability to tie different kinds of information together because they refer to the same place (Longley et al., 2001). GIS-T, the application of geographic information science and systems to transportation problems, represents one of the most important application areas of GIS-technology today. While traditional GIS formulation's strengths are in mapping display and geodata processing, GIS-T requires new data structures to represent the complexities of transportation networks and to perform different network algorithms in order to fulfil its potential in the field of logistics and distribution logistics. This paper addresses these issues as follows. The section that follows discusses data models and design issues which are specifically oriented to GIS-T, and identifies several improvements of the traditional network data model that are needed to support advanced network analysis in a ground transportation context. These improvements include turn-tables, dynamic segmentation, linear referencing, traffic lines and non-planar networks. Most commercial GIS software vendors have extended their basic GIS data model during the past two decades to incorporate these innovations (Goodchild, 1998). The third section shifts attention to network routing problems that have become prominent in GIS-T: the travelling salesman problem, the vehicle routing problem and the shortest path problem with time windows, a problem that occurs as a subproblem in many time constrained routing and scheduling issues of practical importance. Such problems are conceptually simple, but mathematically complex and challenging. The focus is on theory and algorithms for solving these problems. The paper concludes with some final remarks.
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