468 research outputs found
Adversarial-Playground: A Visualization Suite Showing How Adversarial Examples Fool Deep Learning
Recent studies have shown that attackers can force deep learning models to
misclassify so-called "adversarial examples": maliciously generated images
formed by making imperceptible modifications to pixel values. With growing
interest in deep learning for security applications, it is important for
security experts and users of machine learning to recognize how learning
systems may be attacked. Due to the complex nature of deep learning, it is
challenging to understand how deep models can be fooled by adversarial
examples. Thus, we present a web-based visualization tool,
Adversarial-Playground, to demonstrate the efficacy of common adversarial
methods against a convolutional neural network (CNN) system.
Adversarial-Playground is educational, modular and interactive. (1) It enables
non-experts to compare examples visually and to understand why an adversarial
example can fool a CNN-based image classifier. (2) It can help security experts
explore more vulnerability of deep learning as a software module. (3) Building
an interactive visualization is challenging in this domain due to the large
feature space of image classification (generating adversarial examples is slow
in general and visualizing images are costly). Through multiple novel design
choices, our tool can provide fast and accurate responses to user requests.
Empirically, we find that our client-server division strategy reduced the
response time by an average of 1.5 seconds per sample. Our other innovation, a
faster variant of JSMA evasion algorithm, empirically performed twice as fast
as JSMA and yet maintains a comparable evasion rate.
Project source code and data from our experiments available at:
https://github.com/QData/AdversarialDNN-PlaygroundComment: 5 pages. {I.2.6}{Artificial Intelligence} ; {K.6.5}{Management of
Computing and Information Systems}{Security and Protection}. arXiv admin
note: substantial text overlap with arXiv:1706.0176
The effect of insect herbivory on the growth and fitness of introduced Verbascum thapsus L.
A majority of the plant species that are introduced into new ranges either do not become established, or become naturalized yet do not attain high densities and are thus considered ecologically and economically unproblematic. The factors that limit these relatively “benign” species are not well studied. The biotic resistance hypothesis predicts that herbivores, pathogens and competition reduce growth and reproduction of individual plants and so suppress population growth of non-native species. We explored the effect of insect herbivory and surrounding vegetation on growth and fitness of the non-native biennial plant Verbascum thapsus (common mullein) in Colorado, USA. Mullein is widespread in its introduced North American range, yet is infrequently considered a management concern because populations are often ephemeral and restricted to disturbed sites. To evaluate the impact of insect herbivores on mullein performance, we reduced herbivory using an insecticide treatment and compared sprayed plants to those exposed to ambient levels of herbivory. Reducing herbivory increased survival from rosette to reproduction by 7%, from 70–77%. Of plants that survived, reducing herbivory increased plant area in the first year and plant height, the length of the reproductive spike, and seed set during the second year. Reducing herbivory also had a marked effect on plant fitness, increasing seed set by 50%, from about 48,000 seeds per plant under ambient herbivory to about 98,000 per plant under reduced herbivory. Our findings also highlight that the relationship between herbivory and performance is complex. Among plants exposed to ambient herbivory, we observed a positive relationship between damage and performance, suggesting that, as predicted by the plant vigor hypothesis, insect herbivores choose the largest plants for feeding when their choice is not restricted by insecticide treatment. In contrast to the strong effects of experimentally reduced herbivory, we found that cover of other plants surrounding our focal plants explained relatively little variation in performance outcomes. Overall, we found that herbivore-induced impacts on individual plant performance and seed set are substantial, and thus may help prevent this naturalized species from becoming dominant in undisturbed recipient communities
Augmentation of the Egg Parasitoid Anaphes iole (Hymenoptera: Mymaridae) for Lygus hesperus (Heteroptera:Miridae) Management in Strawberries
The impact of repeated releases of Anaphes iole (Girault) on the development of Lygus hesperus Knight populations and fruit damage in commercial strawberry fields was evaluated. Following the release of 37,000 parasitoids per hectare, 50% of L. hesperus eggs were parasitized. Parasitism levels declined rapidly; after 96 h, parasitism levels had declined to an average of only 3.5% in these plots. A release rate of 12,300 parasitoids per hectare produced parasitism levels of 6.3 and 7.0% 48 and 96 h after release, respectively. The high release rate of the parasitoids resulted in a 43% reduction in the number of L. hesperus nymphs and a 22% reduction in the amount of fruit damage. The low release rate responded in a comparable fashion, with nymph and damage levels 19 and 14% lower than control plots, respectively. The effect of the parasitoid releases on L. hesperus populations increased through time. On average, there was a proportionally greater reduction in nymph densities in the higher release rate plots during the latter half of the season. In all the plots, there was a significant relationship between the number of L. hesperus nymphs found in the plot and the amount of fruit damage. The significance of these results to management of L. hesperus in strawberries is discusse
Einstein equations in the null quasi-spherical gauge III: numerical algorithms
We describe numerical techniques used in the construction of our 4th order
evolution for the full Einstein equations, and assess the accuracy of
representative solutions. The code is based on a null gauge with a
quasi-spherical radial coordinate, and simulates the interaction of a single
black hole with gravitational radiation. Techniques used include spherical
harmonic representations, convolution spline interpolation and filtering, and
an RK4 "method of lines" evolution. For sample initial data of "intermediate"
size (gravitational field with 19% of the black hole mass), the code is
accurate to 1 part in 10^5, until null time z=55 when the coordinate condition
breaks down.Comment: Latex, 38 pages, 29 figures (360Kb compressed
A more representative chamber: representation and the House of Lords
Since 1997 there has been substantive reform of the House of Lords in an effort to make the chamber ‘more democratic and more representative’. Whilst the Labour government failed to press ahead with any of the proposed plans for further reform following the removal of the bulk of the hereditary peers in 1999, it remained committed to the notion that such reform must make the second chamber ‘more representative’. The coalition government's programme advocates a long-term aspiration for a House wholly or mainly elected on the basis of proportional representation, and a short-term approach based on additional appointments to ensure a balance of the parties. What is clear in all of these proposals for reform is a desire for the House of Lords to become more representative than it is at present. However, what is less clear is what is meant by ‘representative’ – who the House of Lords is supposed to represent, and what form representation will take. Moreover, in proposing to make the chamber more representative, either through appointment or election, little attention has been paid to how the current House of Lords provides representation. This article examines these questions in the context of Pitkin's classic conceptions of representation and peers' attitudes towards their own representative rol
MEMS practice, from the lab to the telescope
Micro-electro-mechanical systems (MEMS) technology can provide for deformable
mirrors (DMs) with excellent performance within a favorable economy of scale.
Large MEMS-based astronomical adaptive optics (AO) systems such as the Gemini
Planet Imager are coming on-line soon. As MEMS DM end-users, we discuss our
decade of practice with the micromirrors, from inspecting and characterizing
devices to evaluating their performance in the lab. We also show MEMS wavefront
correction on-sky with the "Villages" AO system on a 1-m telescope, including
open-loop control and visible-light imaging. Our work demonstrates the maturity
of MEMS technology for astronomical adaptive optics.Comment: 14 pages, 15 figures, Invited Paper, SPIE Photonics West 201
A faculty–librarian collaboration successsStory: Implementing a teach-the-teacher library and information literacy instruction model in a first-year agricultural science course
Teaching information literacy requires a constant and evolving paradigm shift in today's fast-changing technology era. Add to this the intricacy of agricultural science education, and it becomes clear that instructors face challenges teaching the necessary research skills to prepare the next generation of scientists. Two faculty members in Colorado State University's College of Agricultural Sciences identified a need to redesign a core agricultural science course after observing their students struggle with research and writing. These professors improved their course through a redesign program that connected them with librarians. This collaboration led to the creation of a scaffold to help students build information literacy skills through a first-year agricultural science course. In this paper the authors discuss this collaboration, including four key factors to the program's success: a) a faculty–librarian partnership through a learning and teaching institute; b) early exposure to information literacy skills in a first-year agricultural science course; c) the integration of a research guide in a Learning Management System (LMS), and a step-by-step library and information literacy instruction session with a library assignment; and d) a teach-the-teacher model using graduate students from the respective discipline. The authors also analyze student evaluation outcomes and reflect on future improvements
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