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Bank reputation and securitization quality:European evidence
We examine the link between issuer bank reputation and the performance of mortgage-backed securities (MBS) in the European market. We find that MBS sold by reputable issuer banks are collateralised by higher quality asset pools with lower delinquency rates and are less likely to be downgraded. However, during boom periods – characterized by declining credit standards, MBS originated by reputable issuer banks tend to be collateralised by lower quality assets, compared to normal periods
Modeling of seawater intrusion in a coastal aquifer of Karaburun Peninsula, western Turkey
Seawater intrusion is a major problem to freshwater resources especially in coastal areas where fresh groundwater is surrounded and could be easily influenced by seawater. This study presents the development of a conceptual and numerical model for the coastal aquifer of Karareis region (Karaburun Peninsula) in the western part of Turkey. The study also presents the interpretation and the analysis of the time series data of groundwater levels recorded by data loggers. The SEAWAT model is used in this study to solve the density-dependent flow field and seawater intrusion in the coastal aquifer that is under excessive pumping particularly during summer months. The model was calibrated using the average values of a 1-year dataset and further verified by the average values of another year. Five potential scenarios were analyzed to understand the effects of pumping and climate change on groundwater levels and the extent of seawater intrusion in the next 10 years. The result of the analysis demonstrated high levels of electrical conductivity and chloride along the coastal part of the study area. As a result of the numerical model, seawater intrusion is simulated to move about 420 m toward the land in the next 10 years under “increased pumping” scenario, while a slight change in water level and TDS concentrations was observed in “climate change” scenario. Results also revealed that a reduction in the pumping rate from Karareis wells will be necessary to protect fresh groundwater from contamination by seawater.Scientific and Technological Research Council of Turkey (TUBITAK 113Y042
Effect of kinetic resonances on the stability of Resistive Wall Mode in Reversed Field Pinch
The kinetic effects, due to the mode resonance with thermal particle drift
motions in the reversed field pinch (RFP) plasmas, are numerically investigated
for the stability of the resistive wall mode, using a non-perturbative
MHD-kinetic hybrid formulation. The kinetic effects are generally found too
weak to substantially change the mode growth rate, or the stability margin,
re-enforcing the fact that the ideal MHD model is rather adequate for
describing the RWM physics in RFP experiments.Comment: Submitted to: Plasma Phys. Control. Fusio
Octilinear Force-Directed Layout with Mental Map Preservation for Schematic Diagrams
We present an algorithm for automatically laying out metro map style schematics using a force-directed approach, where we use a localized version of the standard spring embedder forces combined with an octilinear magnetic force. The two types of forces used during layout are naturally conflicting, and the existing method of simply combining these to generate a resultant force does not give satisfactory results. Hence we vary the forces, emphasizing the standard forces in the beginning to produce a well distributed graph, with the octilinear forces
becoming prevalent at the end of the layout, to ensure that the key requirement of line angles at intervals of 45? is obtained. Our method is considerably faster than the more commonly used search-based approaches, and we believe the results are superior to the previous force-directed approach. We have further developed this technique to address the issues of dynamic schematic layout. We use a Delaunay triangulation to construct a schematic “frame”, which is used to retain relative node positions and permits full control of the level of mental map preservation.
This technique is the first to combine mental map preservation techniques with the additional layout criteria of schematic diagrams. To conclude, we present the results of a study to investigate the relationship between the level of mental map preservation and the user response time and accuracy
State-driven Implicit Modeling for Sparsity and Robustness in Neural Networks
Implicit models are a general class of learning models that forgo the
hierarchical layer structure typical in neural networks and instead define the
internal states based on an ``equilibrium'' equation, offering competitive
performance and reduced memory consumption. However, training such models
usually relies on expensive implicit differentiation for backward propagation.
In this work, we present a new approach to training implicit models, called
State-driven Implicit Modeling (SIM), where we constrain the internal states
and outputs to match that of a baseline model, circumventing costly backward
computations. The training problem becomes convex by construction and can be
solved in a parallel fashion, thanks to its decomposable structure. We
demonstrate how the SIM approach can be applied to significantly improve
sparsity (parameter reduction) and robustness of baseline models trained on
FashionMNIST and CIFAR-100 datasets
Mass Handling of Watermelon Microcuttings
Modifications were made in the configurations of the unitizing, nonselective wire cutters used by Alper et al.(1992) for mass cuttings of Stage II Citrullus lanatus cv. Charlee (watermelon) plant tissue cultures to further enhance productivity. Mounting the cutter in an inverted position over the receiving vessel eliminated time required for filling. This cut-and-dump technique became 4.8 times more productive for the total transfer process than the conventional scalpel and forceps technique when both time and yield of cut segments with visible buds were considered. A concept for growing fewer, larger tissue clusters per vessel in mini-trays with orienting cells and cutting with correspondingly sized orientedcell wire cutters yielded as much tissue fresh weight as conventional agar vessels and afforded the potential to reduce time required for the removal job function with the cut-and-dump technique
Unitized, Nonselective Cutting of In Vitro Watermelon
Unitized, nonselective mass cutting of Stage II Citrullus lanatus cv. Charlee (watermelon) plant tissue cultures has been achieved with various configurations and sizes of wire cutter devices. Time studies revealed that the wire cutters increased the productivity of the cutting function over conventional scalpel and forceps by a factor of 14, Total transfer productivity, including the manual functions of removing tissue from an initial culture vessel and filling (sorting and placing cut tissue segments) new vessels, was increased by a factor of 1,8, The square grid-type cutting devices yielded from 48 to 59% as many viable bud clusters per culture vessel as hand cutting and from 65 to 95% as much tissue fresh weight. An oriented-cell configuration of wire cutter actually increased tissue fresh weight about 20% over hand cutting. The simplicity of construction and quality of material of the wire cutter render it readily autoclavable and highly flexible to function both as an aid to small operations and as an element in more sophisticated mechanical devices for larger operations
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