386 research outputs found
Why Clean Generalization and Robust Overfitting Both Happen in Adversarial Training
Adversarial training is a standard method to train deep neural networks to be
robust to adversarial perturbation. Similar to surprising ability in the standard deep learning setting, neural networks
trained by adversarial training also generalize well for . However, in constrast with clean generalization, while adversarial
training method is able to achieve low , there
still exists a significant , which promotes
us exploring what mechanism leads to both during learning process. In this paper, we provide
a theoretical understanding of this CGRO phenomenon in adversarial training.
First, we propose a theoretical framework of adversarial training, where we
analyze to explain how adversarial training
leads network learner to CGRO regime. Specifically, we prove that, under our
patch-structured dataset, the CNN model provably partially learns the true
feature but exactly memorizes the spurious features from training-adversarial
examples, which thus results in clean generalization and robust overfitting.
For more general data assumption, we then show the efficiency of CGRO
classifier from the perspective of . On the
empirical side, to verify our theoretical analysis in real-world vision
dataset, we investigate the during
training. Moreover, inspired by our experiments, we prove a robust
generalization bound based on of loss landscape,
which may be an independent interest.Comment: 27 pages, comments welcom
Persistence In Commodity ETF Performance
Commodities ETFs have became popular investments since first introduced in the market. This type of funds provide investors a simple way to gain exposure to commodities, and these types of funds are considered as an asset class to diversify investment portfolios and as a hedge against economic recessions. With more capital invested in commodities ETFs by investors, argument about the efficiency in commodity ETF market are heated debate by economists. This paper developed a reasonable method to explore persistence in commodity ETFs. 30 commodities ETFs, which ranked high in terms of large assets, are selected during the period of 2008 to 2013. The pair-wised t-test results shows neither persistence nor reversal in commodity ETF returns for both short-term and long-term. The correlation indicates in general there exist high correlation among different ranking mix over different time frames. We conclude that there is no persistence in commodity ETF performance and the commodity ETF market is efficient
Comment on "Atomic Scale Structure and Chemical Composition across Order-Disorder Interfaces"
Interfaces have long been known to be the key to many mechanical and electric
properties. To nickel base superalloys which have perfect creep and fatigue
properties and have been widely used as materials of turbine blades, interfaces
determine the strengthening capacities in high temperature. By means of high
resolution scanning transmission electron microscopy (HRSTEM) and 3D atom probe
(3DAP) tomography, Srinivasan et al. proposed a new point that in nickel base
superalloys there exist two different interfacial widths across the
{\gamma}/{\gamma}' interface, one corresponding to an order-disorder
transition, and the other to the composition transition. We argue about this
conclusion in this comment
Clinical application of transcranial magnetic stimulation for functional bowel disease
Functional bowel disorder (FBD) is a common gastrointestinal disease syndrome characterized by dysmotility and secretion without known organic lesions. The pathogenesis of FBD is still unclear. In recent years, with the rise of neurogastroenterology, it has initially revealed its close relationship with the “brain-gut axis.” Transcranial magnetic stimulation (TMS) is a technique for detecting and treating the nervous system, that is characterized by non-invasiveness and painlessness. TMS plays an important role in the diagnosis and treatment of diseases, and provides a new method for the treatment of FBD. In this paper, we summarized and analyzed the research progress of using TMS therapy applied to patients with irritable bowel syndrome and functional constipation by domestic and foreign scholars in recent years by means of literature search, and found that TMS therapy could improve the intestinal discomfort and accompanying mental symptoms in patients with FBD
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