2,230 research outputs found
Liquidity, term spreads and monetary policy
We propose a model that delivers endogenous variations in term spreads driven primarily by banks' portfolio decision and their appetite to bear the risk of maturity transformation. We first show that fluctuations of the future profitability of banks' portfolios affect their ability to cover for any liquidity shortage and hence influence the premium they require to carry maturity risk. During a boom, profitability is increasing and thus spreads are low, while during a recession profitability is decreasing and spreads are high, in accordance with the cyclical properties of term spreads in the data. Second, we use the model to look at monetary policy and show that allowing banks to sell long-term assets to the central bank after a liquidity shock leads to a sharp decrease in long-term rates and term spreads. Such interventions have significant impact on long-term investment, decreasing the amplitude of output responses after a liquidity shock. The short-term rate does not need to be decreased as much and inflation turns out to be much higher than if no QE interventions were implemented. Finally, we provide macro and micro-econometric evidence for the U.S. confirming the importance of expected financial business profitability in the determination of term spread fluctuations
Lending relationships and monetary policy
Financial intermediation and bank spreads are important elements in the analysis of business cycle transmission and monetary policy. We present a simple framework that introduces lending relationships, a relevant feature of financial intermediation that has been so far neglected in the monetary economics literature, into a dynamic stochastic general equilibrium model with staggered prices and cost channels. Our main findings are: (i) banking spreads move countercyclically generating amplified output responses, (ii) spread movements are important for monetary policy making even when a standard Taylor rule is employed (iii) modifying the policy rule to include a banking spread adjustment improves stabilization of shocks and increases welfare when compared to rules that only respond to output gap and inflation, and finally (iv) the presence of strong lending relationships in the banking sector can lead to indeterminacy of equilibrium forcing the central bank to react to spread movements
Liquidity effects and cost channels in monetary transmission
We study liquidity effects and cost channels within a model of nominal rigidities and imperfect competition that gives explicit role for money-credit markets and investment decisions. We find that cost channels matter for monetary transmission, amplifying the impact of supply shocks and dampening the effects of demand shocks. Liquidity effects only obtain when the policy is specified by an interest rate policy rule and money-credit conditions are determined endogenously. We also find that determinacy issues are particularly relevant when models include the cost channel and explicit money-credit markets
Investment cost channel and monetary transmission
We show that a standard DSGE model with investment cost channels has important model stability and policy implications. Our analysis suggests that in economies characterized by supply side well as demand side channels of monetary transmission, policymakers may have to resort to a much more aggressive stand against inflation to obtain locally unique equilibrium. In such an environment targeting output gap may cause model instability. We also show that it is difficult to distinguish between the New Keynesian model and labor cost channel only case, while with investment cost channel differences are more significant. This result is important as it suggests that if one does not take into account the investment cost channel, one is underestimating the importance of supply side effects
Foreword to the special issue on pattern recognition in remote sensing
Cataloged from PDF version of article.The nine papers in this special issue focus on covering different aspects of remote sensing image analysis. © 2012 IEE
Medium-run implications of changing demographic structures for the macro-economy
While there may be an important, but transitory, cyclical component in the poor performance of the past decade, we will emphasise the secular forces: the impact of demographic structure and innovation. We draw on the empirical and theoretical work reported in Aksoy, Basso, Smith and Grasl (2015), ABSG, about the impact of changes in demographic structure on macroeconomic outcomes. This suggests that changes in age profile not only have significant implications for savings, investment, real interest rates and growth but also for innovation. The size of the effects seems plausible. For instance, if in 2015 the UK had the 1970 age structure, it would have added 0.68 percentage points to the long-run annual growth rate. The model suggests that the population ageing predicted for the next decades will tend to reduce output growth and real interest rates across OECD countries
Automatic mapping of linear woody vegetation features in agricultural landscapes using very high resolution imagery
Cataloged from PDF version of article.Automatic mapping and monitoring of agricultural
landscapes using remotely sensed imagery has been an important
research problem. This paper describes our work on developing
automatic methods for the detection of target landscape features
in very high spatial resolution images. The target objects of interest
consist of linear strips of woody vegetation that include
hedgerows and riparian vegetation that are important elements of
the landscape ecology and biodiversity. The proposed framework
exploits the spectral, textural, and shape properties of objects
using hierarchical feature extraction and decision-making steps.
First, a multifeature and multiscale strategy is used to be able
to cover different characteristics of these objects in a wide range
of landscapes. Discriminant functions trained on combinations of
spectral and textural features are used to select the pixels that may
belong to candidate objects. Then, a shape analysis step employs
morphological top-hat transforms to locate the woody vegetation
areas that fall within the width limits of an acceptable object,
and a skeletonization and iterative least-squares fitting procedure
quantifies the linearity of the objects using the uniformity of the
estimated radii along the skeleton points. Extensive experiments
using QuickBird imagery from three European Union member
states show that the proposed algorithms provide good localization
of the target objects in a wide range of landscapes with very
different characteristics
Intrinsic Harmonization for Illumination-Aware Compositing
Despite significant advancements in network-based image harmonization
techniques, there still exists a domain disparity between typical training
pairs and real-world composites encountered during inference. Most existing
methods are trained to reverse global edits made on segmented image regions,
which fail to accurately capture the lighting inconsistencies between the
foreground and background found in composited images. In this work, we
introduce a self-supervised illumination harmonization approach formulated in
the intrinsic image domain. First, we estimate a simple global lighting model
from mid-level vision representations to generate a rough shading for the
foreground region. A network then refines this inferred shading to generate a
harmonious re-shading that aligns with the background scene. In order to match
the color appearance of the foreground and background, we utilize ideas from
prior harmonization approaches to perform parameterized image edits in the
albedo domain. To validate the effectiveness of our approach, we present
results from challenging real-world composites and conduct a user study to
objectively measure the enhanced realism achieved compared to state-of-the-art
harmonization methods.Comment: 10 pages, 8 figures. Accepted to SIGGRAPH Asia 2023 (Conference
Track). Project page: https://yaksoy.github.io/intrinsicCompositing
Investigation of metallo beta lactamases and oxacilinases in carbapenem resistant acinetobacter baumannii strains isolated from inpatients
Background: Resistance to beta-lactam antibiotics is widespread among Acinetobacter strains. Plasmid-mediated metallo beta lactamases (MBL) are responsible for carbapenem resistance, as are oxacillinases (OXA). In recent years, MBL producing carbapenem-resistant strains have been reported in the world and in Turkey in increasing rates. In our country, besides the OXA 51- like enzyme which is inherent in A. baumannii strains, OXA 58-like and OXA 23-like carbapenemases producing strains have also been widely detected. In addition, Verona Imipenemase (VIM) and (IMP)-type MBL have been reported in some centers. Aims: The aim of our study was to investigate the presence of carbapenemases in Acinetobacter strains isolated from hospitalized patients in Edirne. Study Design: Cross-sectional study. Methods: A total of 52 imipenem-resistant A. baumannii strains isolated between January and March 2013 were investigated. The presence of MBL was described phenotypically by the combined disk diffusion test (CDDT), double disk synergy test (DDST), MBL E- test (only performed in 28 strains) and modified Hodge test. blaIMP , blaVIM, blaGIM, blaSIM, blaSPM genes and blaOXA-23, blaOXA-51, blaOXA-40, blaOXA-58 genes were inves- tigated by multiplex polymerase chain reaction (PCR). The blaNDM-1 gene was determined by PCR. Results: By modified Hodge test, 50 strains (96%) were found to be MBL positive. Positivity of MBL was 21% by both CDDT (0.1 M EDTA) and DDST. Twen- ty-four of 28 strains (85.7%) were positive by MBL E-test. OXA 23-like and OXA 51-like carbapenemases were detected in all strains, but OXA 58-like and OXA 40-like carbapenemases-producing A. baumannii were not detected. Also, MBL genes were not detected by genotypic methods. Conclusion: Only OXA 23-like carbapenemase was responsible for carbapenem resistance in carbapenem- resistant Acinetobacter strains in Edirne. The MBL- producing Acinetobacter strain is not yet a problem in our hospital. MBL resistance was found by phenotyp- ing tests, which must be confirmed by genotypic meth- ods; multiplex PCR tests can be easily used for screen- ing MBL
Symmetry fractionalization, mixed-anomalies and dualities in quantum spin models with generalized symmetries
We investigate the gauging of higher-form finite Abelian symmetries and their
sub-groups in quantum spin models in spatial dimensions and 3. Doing so,
we naturally uncover gauged models with dual higher-group symmetries and
potential mixed 't Hooft anomalies. We demonstrate that the mixed anomalies
manifest as the symmetry fractionalization of higher-form symmetries
participating in the mixed anomaly. Gauging is realized as an isomorphism or
duality between the bond algebras that generate the space of quantum spin
models with the dual generalized symmetry structures. We explore the mapping of
gapped phases under such gauging related dualities for 0-form and 1-form
symmetries in spatial dimension and 3. In , these include several
non-trivial dualities between short-range entangled gapped phases with 0-form
symmetries and 0-form symmetry enriched Higgs and (twisted) deconfined phases
of the gauged theory with possible symmetry fractionalizations. Such dualities
also imply strong constraints on several unconventional, i.e., deconfined or
topological transitions. In , among others, we find, dualities between
topological orders via gauging of 1-form symmetries. Hamiltonians self-dual
under gauging of 1-form symmetries host emergent non-invertible symmetries,
realizing higher-categorical generalizations of the Tambara-Yamagami fusion
category.Comment: 90 pages, 19 figure
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