3,883 research outputs found
PROPERTIES OF TWO U.S. INFLATION MEASURES (1985-2005)
Analyses are presented of 84 quarterly observations 1/85-4/05 on two U.S. index numbers of nominal prices often employed to measure inflation. Analyses are designed to answer two key questions of interest to macroeconomists. Is inflation stationary (I(0)) or stochastically non-stationary (I(1))? If it is I(1), is it scalar or multivariate? Both measures of inflation are found clearly to be I(1) and, for these measures, inflation is found clearly to be scalar. The paper also illustrates univariate analysis procedures (and report standards) considered to be more effective and convincing than those found in the existing literature on inflation measures.
Information Misweighting and Stock Recommendations
I provide evidence that analysts whose earnings forecast revisions showed signs of greater exaggeration in the past make recommendation changes that lead to lower abnormal returns than their peers. Interpreting stock recommendations as a forecast of future abnormal returns, I show that this evidence is consistent with the hypothesis that analysts who typically exaggerate or overstate the weight of their private information when issuing forecasts also do so when making recommendations. I also show that past earnings forecast provide incremental information about analysts' recommending behavior beyond that contained in past recommendations.Information misweighting; stock recommendations; earnings forecasts; financial analysts
Modelling hydrological connectivity in burned areas. A case study from South of Spain
Overland flow connectivity depends on the spatio-temporal interactions of hydrological and geomorphic processes as well as on the human footprint on the landscape.
This study deals with the modelling of hydrological connectivity in a burned area with different levels of fire severity. Namely, the objectives are to: i) characterize and ii) modelling the pre- (PreF) and post-fire (PostF) scenarios, as well as iii) evaluate the effect of the vegetation changes due to the fire and the initial post-fire management practices (construction of new skid trails and check-dams) on the magnitude and spatial pattern of connectivity. Four post-fire scenarios are simulated: immediately after the fire (PostF1), with new skids and without check-dams (PostF2), with new skids and check-dams and without vegetation recovery (PostF3), and with new skids and check-dams and incipient vegetation cover (PostF4).
The study area corresponds to eleven headwater sub-catchments (total area of 329 ha) that cover the entire burned area of the mountain in the West and Southwest facing hillslopes (ca. 200 ha). This site is located in the province of Malaga, South of Spain, and all sub-catchments are disconnected between them.
The fire started in 2014, 27 June and lasted two days. The landscape is mainly mountainous, with very steep slopes and marble rocks, Mediterranean climate, and a land use of shrubs and pine forests (pre-fire scenario). Settlements appear at the bottom of the slopes. After the wildfire, land management were carried out in order to remove completely the burned trees and thus new skid trails were built. Then, eleven concrete check-dams and twelve wooded check-dams were built in the main gullies. The different scenarios of linear landscape elements, vegetation cover and modifications on the topography related to the construction of new trails and check-dams were included in the simulations. The IC index of hydrological connectivity was chosen to perform this metric at a spatial resolution of 5 x 5 meters.
The analysis of the different spatial patterns and temporal changes was done considering the different levels of fire severity and changes on hydrological connectivity were also analysed at the outlet of each sub-catchment.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Improved construction of irregular progressive edge-growth Tanner graphs
The progressive edge-growth algorithm is a well-known procedure to construct
regular and irregular low-density parity-check codes. In this paper, we propose
a modification of the original algorithm that improves the performance of these
codes in the waterfall region when constructing codes complying with both,
check and symbol node degree distributions. The proposed algorithm is thus
interesting if a family of irregular codes with a complex check node degree
distribution is used.Comment: 3 pages, 3 figure
Blind Reconciliation
Information reconciliation is a crucial procedure in the classical
post-processing of quantum key distribution (QKD). Poor reconciliation
efficiency, revealing more information than strictly needed, may compromise the
maximum attainable distance, while poor performance of the algorithm limits the
practical throughput in a QKD device. Historically, reconciliation has been
mainly done using close to minimal information disclosure but heavily
interactive procedures, like Cascade, or using less efficient but also less
interactive -just one message is exchanged- procedures, like the ones based in
low-density parity-check (LDPC) codes. The price to pay in the LDPC case is
that good efficiency is only attained for very long codes and in a very narrow
range centered around the quantum bit error rate (QBER) that the code was
designed to reconcile, thus forcing to have several codes if a broad range of
QBER needs to be catered for. Real world implementations of these methods are
thus very demanding, either on computational or communication resources or
both, to the extent that the last generation of GHz clocked QKD systems are
finding a bottleneck in the classical part. In order to produce compact, high
performance and reliable QKD systems it would be highly desirable to remove
these problems. Here we analyse the use of short-length LDPC codes in the
information reconciliation context using a low interactivity, blind, protocol
that avoids an a priori error rate estimation. We demonstrate that 2x10^3 bits
length LDPC codes are suitable for blind reconciliation. Such codes are of high
interest in practice, since they can be used for hardware implementations with
very high throughput.Comment: 22 pages, 8 figure
Untainted Puncturing for Irregular Low-Density Parity-Check Codes
Puncturing is a well-known coding technique widely used for constructing
rate-compatible codes. In this paper, we consider the problem of puncturing
low-density parity-check codes and propose a new algorithm for intentional
puncturing. The algorithm is based on the puncturing of untainted symbols, i.e.
nodes with no punctured symbols within their neighboring set. It is shown that
the algorithm proposed here performs better than previous proposals for a range
of coding rates and short proportions of punctured symbols.Comment: 4 pages, 3 figure
Rate Compatible Protocol for Information Reconciliation: An application to QKD
Information Reconciliation is a mechanism that allows to weed out the
discrepancies between two correlated variables. It is an essential component in
every key agreement protocol where the key has to be transmitted through a
noisy channel. The typical case is in the satellite scenario described by
Maurer in the early 90's. Recently the need has arisen in relation with Quantum
Key Distribution (QKD) protocols, where it is very important not to reveal
unnecessary information in order to maximize the shared key length. In this
paper we present an information reconciliation protocol based on a rate
compatible construction of Low Density Parity Check codes. Our protocol
improves the efficiency of the reconciliation for the whole range of error
rates in the discrete variable QKD context. Its adaptability together with its
low interactivity makes it specially well suited for QKD reconciliation
Global survey of development banks
Historically, development banks have been an important instrument of governments to promote economic growth by providing credit and a wide range of advisory and capacity building programs to households, small and medium enterprises, and even large private corporations, whose financial needs are not sufficiently served by private commercial banks or local capital markets. During the current financial crisis, most development banks in Latin America, followed by Asia, Africa, and Europe, have assumed a countercyclical role by scaling up their lending operations exactly when private banks experienced temporary difficulties in granting credit to the private sector. Despite the importance of development banks during crisis and non-crisis periods, little is known about them. This survey examines how development banks operate, what their policy mandates are, what financial services they offer, which type of clients they target, how they are regulated and supervised, what business models they have adopted, what governance framework they have, and what challenges they face. It also examines the countercyclical role played by development banks during the recent financial crisis. This survey is based on new data that have been collected from 90 national development banks in 61 countries.Banks&Banking Reform,Access to Finance,Debt Markets,Bankruptcy and Resolution of Financial Distress,Emerging Markets
- …