2,997 research outputs found
Discovering Class-Specific Pixels for Weakly-Supervised Semantic Segmentation
We propose an approach to discover class-specific pixels for the
weakly-supervised semantic segmentation task. We show that properly combining
saliency and attention maps allows us to obtain reliable cues capable of
significantly boosting the performance. First, we propose a simple yet powerful
hierarchical approach to discover the class-agnostic salient regions, obtained
using a salient object detector, which otherwise would be ignored. Second, we
use fully convolutional attention maps to reliably localize the class-specific
regions in a given image. We combine these two cues to discover class-specific
pixels which are then used as an approximate ground truth for training a CNN.
While solving the weakly supervised semantic segmentation task, we ensure that
the image-level classification task is also solved in order to enforce the CNN
to assign at least one pixel to each object present in the image.
Experimentally, on the PASCAL VOC12 val and test sets, we obtain the mIoU of
60.8% and 61.9%, achieving the performance gains of 5.1% and 5.2% compared to
the published state-of-the-art results. The code is made publicly available
VIP: Incorporating Human Cognitive Biases in a Probabilistic Model of Retweeting
Information spread in social media depends on a number of factors, including
how the site displays information, how users navigate it to find items of
interest, users' tastes, and the `virality' of information, i.e., its
propensity to be adopted, or retweeted, upon exposure. Probabilistic models can
learn users' tastes from the history of their item adoptions and recommend new
items to users. However, current models ignore cognitive biases that are known
to affect behavior. Specifically, people pay more attention to items at the top
of a list than those in lower positions. As a consequence, items near the top
of a user's social media stream have higher visibility, and are more likely to
be seen and adopted, than those appearing below. Another bias is due to the
item's fitness: some items have a high propensity to spread upon exposure
regardless of the interests of adopting users. We propose a probabilistic model
that incorporates human cognitive biases and personal relevance in the
generative model of information spread. We use the model to predict how
messages containing URLs spread on Twitter. Our work shows that models of user
behavior that account for cognitive factors can better describe and predict
user behavior in social media.Comment: SBP 201
REITs and Idiosyncratic Risk
This study examines various determinants of idiosyncratic risk from the perspective of un-diversified REIT investors, managers holding options, other option holders, and arbitrageurs. Since real estate investment trusts (REITs) enjoy a unique organizational structure and tax status, the relevant determinants derived from the two-stage regression model are different from other industrial firms. Results suggest that efficiency, liquidity and earnings variability are the important determinants of idiosyncratic risk, whereas size and capital do not
Stationarity and Co-Integration in Systems with Three National Real Estate Indices
This study examines the stochastic properties of the commercial real estate wealth indices for three countries (the U.S., Canada, and the U.K.) and for several property types (aggregate, office, retail, and industrial). Each of the indices is tested for a unit root and all series are found to be nonstationary. Furthermore, all indices also indicate the presence of both drift and trend. The results are strongest when the indices are tested in real estate and exchange rate-adjusted form. Application of Johansen's model indicates that the system for the three countries shows evidence of co-integration for the aggregate, retail, office, and industrial properties. Again, the evidence is the strongest when the indices are tested in real and exchange rate-adjusted form. Hence, it is conceivable that inflationary expectations may be the factor that provides the common linkage between commercial real estate across national boundaries.
Long-Term Structural Price Relationships in Real Estate Markets
This study investigates the long-run stochastic properties of real estate assets by geographical breakdown. We also study their linkages with financial assets. The initial tests find that almost all property types exhibit the presence of nonstationarity. Thus, cointegrated methodologies are used. Structural breakpoints identified in the literature are used as a guide to divide the data into two windows, 1983-1989 and 1990-1996. The results show that real estate in the different regions exhibit a closer relationship with each other in the second period, compared with the first. Also, strong linkages between real estate regions and financial assets are noted in the second period. The South is the only region to exhibit segmentation in both periods. Overall, the information derived from our analysis sheds light on linkages among real estate assets and between real estate and financial assets and also provides a framework for creating diversified portfolios.
Uncertainties of size measurements in electron microscopy characterization of nanomaterials in foods
Electron microscopy is a recognized standard tool for nanomaterial characterization, and recommended by the European Food Safety Authority for the size measurement of nanomaterials in food. Despite this, little data have been published assessing the reliability of the method, especially for size measurement of nanomaterials characterized by a broad size distribution and/or added to food matrices. This study is a thorough investigation of the measurement uncertainty when applying electron microscopy for size measurement of engineered nanomaterials in foods. Our results show that the number of measured particles was only a minor source of measurement uncertainty for nanomaterials in food, compared to the combined influence of sampling, sample preparation prior to imaging and the image analysis. The main conclusion is that to improve the measurement reliability, care should be taken to consider replications and matrix removal prior to sample preparation
Are GCC Financial Markets Weak Form Efficient? An Analysis Using Multiple Variance Ratio Test
This paper examined the Efficient Market Hypothesis ( EMH) for seven financial markets located in the Gulf Cooperative Council (GCC) countries; Bahrain Securities Market (BSE), Qatar\u27s Doha Financial Market (DFM), Kuwait Securities Market (KSE) , Oman\u27s Muscat Securities Market (MSM), Saudi Arabia\u27s Tadawul All-Shares Index (TASI), and the two UAE markets, Dubai Securities Market (DSM) and Abu Dhabi Securities Exchange (ADX). This paper utilizes both the runs and multiple variance ratio (MVR) tests on weekly and daily index returns between June 2003 and June 2008. The runs test on weekly data rejects EMH for five out of the seven markets. The more powerful MVR test rejects the EMH for only two markets, Dubai Securities Market (DSM) and Abu Dhabi Securities Exchange (ADX). Keywords: GCC, Multiple Variance Ratio, Weak Form Efficien
Worth Fighting For: Thirty-Five Years of Title IX Advocacy in the Courts, Congress and the Federal Agencies
This article focuses on Title IX and women\u27s continuing struggle to secure equal opportunity on the playing fields. But athletics is not unique. Indeed, the lessons of Title IX in athletics, its importance to women and girls, and how the law has been shaped over the years by advocacy in each branch of government, apply to all the fields of endeavor that still remain only partially available to the young women of this nation. Women and girls continue to lag behind in the STEM (science, technology, engineering and math) fields, remain clustered in “traditionally female” programs such as cosmetology that prepare them for low-wage careers, and are still treated like second-class citizens on the playing fields
Focal Plane Array Sensor for Imaging Infrared Seeker of Antitank Guided Missile
Technological issues and Processes for fabrication of mercury cadmium telluride detector arrays, charge coupled device readout arrays and integration of these into a focal plane array sensor have been discussed. Mini arrays of 16 X 16 size have been realised and tested to prove the technology and process schedule with a view to scaling up this for larger arrays to be used in the antitank guided missile
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