3,695 research outputs found
Role of bank branch locations in minority lending
Past studies on discrimination in home mortgage lending have focused on the loan approval process, yet results show that most of the variation in minority lending across banks is due to the variation in the volume of minority applications and not the variation in the minority approval rate. This paper focuses instead on the application stage and the impact of branch locations on minority applications and lending. The presence of branches in minority areas significantly increases a bank\u27s volume of minority applications and hence its minority lending; however, branch locations do not appear to affect the minority approval rate. These finding refute the argument that banks take in deposits but do not lend in minority areas, and the view that technological innovations such as telephone banking have made branches obsolete. They suggest that the current policy of emphasizing branches in minority areas may be effective in increasing minority lending at individual banks, but not necessarily the overall lending in a minority area
NEW APPROACHES FOR VERY SHORT-TERM STEADY-STATE ANALYSIS OF AN ELECTRICAL DISTRIBUTION SYSTEM WITH WIND FARMS
Distribution networks are undergoing radical changes due to the high level of penetration of dispersed generation. Dispersed generation systems require particular attention due to their incorporation of uncertain energy sources, such as wind farms, and due to the impacts that such sources have on the planning and operation of distribution networks. In particular, the foreseeable, extensive use of wind turbine generator units in the future requires that distribution system engineers properly account for their impacts on the system. Many new technical considerations must be addressed, including protection coordination, steady-state analysis, and power quality issues. This paper deals with the very short-term, steady-state analysis of a distribution system with wind farms, for which the time horizon of interest ranges from one hour to a few hours ahead. Several wind-forecasting methods are presented in order to obtain reliable input data for the steady-state analysis. Both deterministic and probabilistic methods were considered and used in performing deterministic and probabilistic load-flow analyses. Numerical applications on a 17-bus, medium-voltage, electrical distribution system with various wind farms connected at different busbars are presented and discusse
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Rational Herding and The Spatial Clustering of Bank Branches: An Empirical Analysis
Bank Branches in NYC tend to be spatial clustered. For instance, of the 221 branches that were opened in NYC between July 1990 and June 1995-, 181 or 82 percent were opened in census tracts that already had at least one other branch. A number of recent theoretical papers have highlighted the possibility of rational herding in various arenas of economic activity. This paper explores empirically whether the apparent clustering of bank branches can be at least partially attributed to rational herding by banks. We find that even after controlling for the expected profitability of operating a branch in an area, branch openings follow other, existing branches. Moreover, such band wagon behavior appears to reduce branch profits. These findings, combined, suggest that herd behavior may be a factor in the branch location decisions of banks
Molecular Modification of CNT Junctions
Carbon nanotube networks (CNNs) are increasingly finding applications as thin film transistors (TFTs), integrated circuits, and display drivers on flexible, transparent substrates. This is attributed to the higher carrier mobility of CNNs as compared to amorphous silicon and organic TFTs [1,2]. However, high electrical [3-5] and thermal [6,7] resistances at individual nanotube junctions (NJs) limit the performance of CNN devices. The resistances of the junctions are no less than an order of magnitude higher than those of individual carbon nanotubes (CNTs). This causes high power dissipation at the NJs. In the end this causes degradation of the overall device performance and reliability [3,4]. Previous studies have shown how molecular modification of CNT junctions can reduce the sheet resistance of conducting and transparent CNN electrodes. [refs to Vikar and Bao]. However, to our knowledge, the effects of molecular modification of CNT junctions on device performance remain unreported.
In this study, we present a novel method to improve CNN TFT performance, through the application of 0-dimensional (0D) molecules, e.g. C60 fullerenes and CdSe quantum dots, onto the surface of the CNN device. These materials can be applied through spin-coating, dip-coating, or spray coating. We find the absorbance spectra of the 0D materials correlate with their HOMO-LUMO gap and concentration of these molecules in solution. Our preliminary data also suggest preferential attachment of these nanoparticles to NJs, eliminating the need for lithography to selectively deposit 0D materials at NJs. Our results suggests these molecules may act as a nanosolder or nanoglue at the NJs, modifying their electrical and thermal resistances for improved device performance.
[1] D. Sun, et al., Nat. Nanotechnol. 6, 156 (2011); [2] Q. Cao, et al., Nature 454, 495 (2008); [3] P. Nirmalraj, et al., Nano Lett. 9, 3890 (2009); [4] M. Stadermann, et al., Phys. Rev. B: Condens. Matter Mater. Phys. 69, 201402 (2004); [5] A. Kyrylyuk, et al., Nat. Nanotechnol. 6, 364 (2011); [6] R. Prasher, et al., Phys. Rev. Lett. 102, 105901 (2009); [7] J. Yang, et al., Appl. Phys. Lett. 96, 023109 (2010)
Handing the Microphone to Women: Changes in Gender Representation in Editorial Contributions Across Medical and Health Journals 2008-2018
The editorial materials in top medical and public health journals are opportunities for experts to offer thoughts that might influence the trajectory of the field. To date, while some studies have examined gender bias in the publication of editorial materials in medical journals, none have studied public health journals. In this perspective, we studied the gender ratio of the editorial materials published in the top health and medical sciences journals between 2008 and early 2018 to test whether gender bias exists. We studied a total of 59 top journals in health and medical sciences. Overall, while there is a trend of increasing proportion of female first authors, there is still a greater proportion of male than female first authors. The average male-to-female first author ratio during the study period across all journals was 2.08. Ensuring equal access and exposure through journal editorials is a critical step, albeit only one step of a longer journey, towards gender balance in health and medical sciences research. Editors of top journals have a key role to play in pushing the fields towards more balanced gender equality, and we strongly urge editors to rethink the strategies for inviting authors for editorial materials
Matterport3D: Learning from RGB-D Data in Indoor Environments
Access to large, diverse RGB-D datasets is critical for training RGB-D scene
understanding algorithms. However, existing datasets still cover only a limited
number of views or a restricted scale of spaces. In this paper, we introduce
Matterport3D, a large-scale RGB-D dataset containing 10,800 panoramic views
from 194,400 RGB-D images of 90 building-scale scenes. Annotations are provided
with surface reconstructions, camera poses, and 2D and 3D semantic
segmentations. The precise global alignment and comprehensive, diverse
panoramic set of views over entire buildings enable a variety of supervised and
self-supervised computer vision tasks, including keypoint matching, view
overlap prediction, normal prediction from color, semantic segmentation, and
region classification
Multi-Device Task-Oriented Communication via Maximal Coding Rate Reduction
Task-oriented communication offers ample opportunities to alleviate the
communication burden in next-generation wireless networks. Most existing work
designed the physical-layer communication modules and learning-based codecs
with distinct objectives: learning is targeted at accurate execution of
specific tasks, while communication aims at optimizing conventional
communication metrics, such as throughput maximization, delay minimization, or
bit error rate minimization. The inconsistency between the design objectives
may hinder the exploitation of the full benefits of task-oriented
communications. In this paper, we consider a specific task-oriented
communication system for multi-device edge inference over a multiple-input
multiple-output (MIMO) multiple-access channel, where the learning (i.e.,
feature encoding and classification) and communication (i.e., precoding)
modules are designed with the same goal of inference accuracy maximization.
Instead of end-to-end learning which involves both the task dataset and
wireless channel during training, we advocate a separate design of learning and
communication to achieve the consistent goal. Specifically, we leverage the
maximal coding rate reduction (MCR2) objective as a surrogate to represent the
inference accuracy, which allows us to explicitly formulate the precoding
optimization problem. We cast valuable insights into this formulation and
develop a block coordinate descent (BCD) solution algorithm. Moreover, the MCR2
objective also serves the loss function of the feature encoding network, based
on which we characterize the received features as a Gaussian mixture (GM)
model, facilitating a maximum a posteriori (MAP) classifier to infer the
result. Simulation results on both the synthetic and real-world datasets
demonstrate the superior performance of the proposed method compared to various
baselines.Comment: submitted to IEEE for possible publicatio
Scala with Explicit Nulls
The Scala programming language makes all reference types implicitly nullable. This is a problem, because null references do not support most operations that do make sense on regular objects, leading to runtime errors. In this paper, we present a modification to the Scala type system that makes nullability explicit in the types. Specifically, we make reference types non-nullable by default, while still allowing for nullable types via union types. We have implemented this design for explicit nulls as a fork of the Dotty (Scala 3) compiler. We evaluate our scheme by migrating a number of Scala libraries to use explicit nulls. Finally, we give a denotational semantics of type nullification, the interoperability layer between Java and Scala with explicit nulls. We show a soundness theorem stating that, for variants of System F_? that model Java and Scala, nullification preserves values of types
Scala with Explicit Nulls (Artifact)
This artifact is a companion to the paper "Scala with Explicit Nulls", where we present a modification to the Scala type system that makes nullability explicit in the types. Specifically, we make reference types non-nullable by default, while still allowing for nullable types via union types.
The artifact contains an implementation of this new type system design as a fork of the Dotty (Scala 3) compiler. Additionally, the artifact contains the source code of multiple Scala libraries that we used to evaluate our design
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