Why do These Match? Explaining the Behavior of Image Similarity Models

Explaining a deep learning model can help users understand its behavior and allow researchers to discern its shortcomings. Recent work has primarily focused on explaining models for tasks like image classification or visual question answering. In this paper, we introduce Salient Attributes for Network Explanation (SANE) to explain image similarity models, where a model's output is a score measuring the similarity of two inputs rather than a classification score. In this task, an explanation depends on both of the input images, so standard methods do not apply. Our SANE explanations pairs a saliency map identifying important image regions with an attribute that best explains the match. We find that our explanations provide additional information not typically captured by saliency maps alone, and can also improve performance on the classic task of attribute recognition. Our approach's ability to generalize is demonstrated on two datasets from diverse domains, Polyvore Outfits and Animals with Attributes 2. Code available at: https://github.com/VisionLearningGroup/SANEComment: Accepted at ECCV 202

Global shape processing involves feature-selective and feature-agnostic coding mechanisms

Recent research and modeling proposes that a closed shape is accurately described by both the curvature and angular location of its parts relative to the shape center, implying that the shape is coded along with its overall orientation.We tested this proposition. Radial frequency (RF) patterns were employed as stimuli as they can represent a range of familiar closed shapes and are processed globally. We measured a RF amplitude aftereffect (RFAAE) as a function of the shape orientation difference between adapt and test patterns of the same RF. For RF3 and RF4, RFAAEs were largest when adapt and test patterns were the same orientation, and then linearly decreased as the adaptor was rotated away from the test. RFAAEs did not, however, reach zero, instead plateauing significantly above zero. On the other hand, when adapt and test were of opposite luminance polarity, RFAAEs, although lower than same luminance-polarity RFAAEs, were invariant to differences between adapt and test orientations. Our findings provide evidence for two global shape mechanisms: one that is selective for shape orientation and luminance polarity, and one that is agnostic to these characteristics

Using projective invariants for constant time library indexing in model based vision

Projectively invariant shape descriptors allow fast indexing into model libraries, because recognition proceeds without reference to object pose. This paper describes progress in building a large model based vision system which uses many projectively invariant descriptors. We give a brief account of these descriptors and then describe the recognition system, giving examples of the invariant techniques working on real images. We demonstrate the ease of model acquisition in our system, where models are generated directly from images. We demonstrate fast recognition without determining object pose or camera parameters

Imaging correlates of molecular signatures in oligodendrogliomas.

Molecular subsets of oligodendroglioma behave in biologically distinct ways. Their locations in the brain, rates of growth, and responses to therapy differ with their genotypes. Retrospectively, we inquired whether allelic loss of chromosomal arms 1p and 19q, an early molecular event and favorable prognostic marker in oligodendrogliomas, were reflected in their appearance on magnetic resonance imaging. Loss of 1p and 19q was associated with an indistinct border on T(1) images and mixed intensity signal on T(1) and T(2). Loss of 1p and 19q was also associated with paramagnetic susceptibility effect and with calcification, a common histopathological finding in oligodendrogliomas. These data encourage prospective evaluation of molecular alterations and magnetic resonance imaging characteristics of glial neoplasms

Temporal and spatial programming in soft composite hydrogel objects

Soft composite hydrogel objects formed from the biopolymer sodium alginate, the enzyme urease, and oil droplets are formed by a simple gelation procedure to produce autonomous bodies with both time and spatial programming. These continuous objects of non-uniform dimensional composition selectively respond to an environmental stimulus of urea and change colour or disintegrate at pre-defined locations within the hydrogel structure after pre-set time intervals. The spatial and temporal responses of these hydrogels to an environmental stimulus are valuable tools in areas such as soft robotics

Origins and population genetics of sambar deer (Cervus unicolor) introduced to Australia and New Zealand

Context. Some populations of introduced species cause significant undesirable impacts but can also act as reservoirs for genetic diversity. Sambar deer (Cervus unicolor) are ‘Vulnerable’ in their native range and invasive in Australia and New Zealand. Genetic data can be used to determine whether these introduced populations might serve as genetic reservoirs for declining native populations and to identify spatial units for management. Aims. We aimed to identify the provenance of sambar deer in Australia and New Zealand, and to characterise their genetic diversity and population structure. Methods. We used mitochondrial control region sequences and 18 nuclear microsatellite loci of 24 New Zealand and 63 Australian sambar deer collected across continuous habitat in each location. We estimated genetic diversity and population differentiation by using pairwise FST, AMOVA, and STRUCTURE analyses. We compared our data with 27 previously published native and invasive range sequences to identify phylogenetic relationships. Key results. Sambar deer in Australia and New Zealand are genetically more similar to those in the west of the native range (South and Central Highlands of India, and Sri Lanka), than to those in the east (eastern India, and throughout Southeast Asia). Nuclear genetic diversity was lower than in the native range; only one mitochondrial haplotype was found in each introduced population. Australian and New Zealand sambar deer were genetically distinct but there was no population structure within either population. Conclusions. The genetic differences we identified between these two introduced populations at putatively neutral loci indicate that there also may be underlying diversity at functional loci. The lack of population genetic structure that we found within introduced populations suggests that individuals within these popula- tions do not experience barriers to dispersal across the areas sampled. Implications. Although genetic diversity is reduced in the introduced range compared with the native range, sambar deer in Australia and New Zealand harbour unique genetic variants that could be used to strengthen genetic diversity in populations under threat in the native range. The apparent high levels of gene flow across the areas we sampled suggest that localised control is unlikely to be effective in Australia and New Zealand

Research Article Effects on Semiconductor Optical Amplifier Gain Quality for Applications in Advanced All-optical Communication Systems

Abstract: Semiconductor optical amplifiers are strong candidates to replace traditional erbium-doped-fibreamplifiers in future all-optical networks by virtue of their proven functional capabilities, in addition to gain. They are also smaller, cheaper and easier to integrate than fibre amplifiers. This study summarizes the gain quality of the semiconductor optical amplifier with varying effects such as input power, bias current and wavelength and data rate. The results reported herein show high quality gain, coupled with accept ably low noise figure values

Effects on semiconductor optical amplifier gain quality for applications in advanced all-optical communication systems

Semiconductor optical amplifiers are strong candidates to replace traditional erbium-doped-fibre-amplifiers in future all-optical networks by virtue of their proven functional capabilities, in addition to gain. They are also smaller, cheaper and easier to integrate than fibre amplifiers. This study summarizes the gain quality of the semiconductor optical amplifier with varying effects such as input power, bias current and wavelength and data rate. The results reported herein show high quality gain, coupled with accept ably low noise figure values

Neutron scattering for STRUCTURAL BIOLOGY

The past two decades have seen explosive growth in research on structural molecular biology. High-throughput techniques for determining biological structures are yielding large amounts of information about atomic-, cellular-, and tissue-scale organization. Advances are driven by modern high-brilliance synchrotron sources, synchrotron-based full-field x-ray microscopy and tomography, free-electron lasers, and cryoelectron microscopy facilities. The scientific landscape is changing at a remarkable pace with increasing emphasis being placed on interdisciplinary and multi-technique approaches. Neutron scattering facilities around the globe are expanding their capabilities to provide unique and complementary insights about biological systems