11,271 research outputs found
Magnetic Field Effects in the Pseudogap Phase: A Precursor Superconductivity Scenario
We demonstrate that the observed dependences of and on small
magnetic fields can be readily understood in a precursor superconductivity
approach to the pseudogap phase. In this approach, the presence of a pseudogap
at (but not at ) and the associated suppression of the density of
states lead to very different sensitivities to pair-breaking perturbations for
the two temperatures. Our semi-quantitative results address the puzzling
experimental observation that the coherence length is weakly dependent on
hole concentration throughout most of the phase diagram. We present our
results in a form which can be compared with the recent experiments of
Shibauchi et al, and argue that orbital effects contribute in an important way
to the dependence of .Comment: 6 pages, 1 figure, elsart.cls included. Submitted to the proceeding
of SNS 2001, Chicag
Computer Aided Diagnosis System for Wireless Capsule Endoscopy Video
Along with the advancing of technology in wireless and miniature camera, Wireless Capsule Endoscopy (WCE), the combination of both, enables a physician to diagnose patient's digestive system without actually perform a surgical procedure. Although WCE is a technical breakthrough that allows physicians to visualize the entire small bowel noninvasively, the video viewing time takes 1 - 2 hours. Not only it sets a limit on the wide application of this technology but also it incurs considerable amount of cost. Therefore, it is important to automate such process so that the medical clinicians only focus on interested events. As an extension from our previous work that characterizes the motility of digestive tract in WCE videos, we propose a new assessment system for energy based events detection (EG-EBD) to classify the events in WCE videos. For the system, we first extract general features of a WCE video that can characterize the intestinal contractions in digestive organs. Then, the event boundaries are identified by using High Frequency Content (HFC) function. The segments are classified into WCE event by special features. In this system, we focus on entering duodenum, entering cecum, and active bleeding. This assessment system can be easily extended to discover more WCE events, such as detailed organ segmentation and more diseases, by using new special features. In addition, the system provides a score for every WCE image for each event. Using the event scores, the system helps a specialist to speedup the diagnosis process
Turnover Premium, Foreign Institutional Ownership, and Time-Varying Risk Premium in Taiwan Equity Markets
The low turnover premium found in U.S. equity markets is also found in Taiwan market, unlike the mixed evidence for other stylized effects such as size, book-to-market ratio and momentum. Consistent with investor overconfidence hypothesis proposed by Odean (1998, 1999), the percentage of foreign institutional shareholdings in a stock is found to vary inversely with turnover premium. This inverse relation is robust to the influence of other forces that may interact with turnover rate, such as market capitalization, book-to-market ratio and 6-month past returns, respectively. Time-varying risk premium, particularly in low turnover-low foreign institutional shareholdings percentage portfolio, provides partial explanation for the phenomenon, but the inverse relation persists after risk adjustment by models such as unconditional CAPM, Fama-French three factor model and conditional CAPM
Existence theorems for a crystal surface model involving the p-Laplace operator
The manufacturing of crystal films lies at the heart of modern
nanotechnology. How to accurately predict the motion of a crystal surface is of
fundamental importance. Many continuum models have been developed for this
purpose, including a number of PDE models, which are often obtained as the
continuum limit of a family of kinetic Monte Carlo models of crystal surface
relaxation that includes both the solid-on-solid and discrete Gaussian models.
In this paper we offer an analytical perspective into some of these models. To
be specific, we study the existence of a weak solution to the boundary value
problem for the equation - \Delta e^{-\mbox{div}\left(|\nabla u|^{p-2}\nabla
u\right)}+au=f, where are given numbers and is a given
function. This problem is derived from a crystal surface model proposed by
J.L.~Marzuola and J.~Weare (2013 Physical Review, E 88, 032403). The
mathematical challenge is due to the fact that the principal term in our
equation is an exponential function of a p-Laplacian. Existence of a
suitably-defined weak solution is established under the assumptions that
, and . Our investigations reveal that the
key to our existence assertion is how to control the set where
-\mbox{div}\left(|\nabla u|^{p-2}\nabla u\right) is
Tianditu: China's first official online mapping service
Tianditu is China’s first state-sponsored web mapping service. Beijing considers Tianditu part and parcel of its burgeoning endeavor to build a ‘digital China’. The Chinese state created Tianditu to regain some of the ground lost when its monopoly on geographic information was effectively broken. This effort goes hand in hand with Beijing’s intention to compete with and shrink the space occupied by Google mapping services (Google Maps, Google Earth, etc.). Although Tianditu does bestow a certain degree of power on civilian users to interact with and explore geographic data, for political and social reasons the Chinese state tightly controls Tianditu. It is a tool that the regime uses to maintain political power and push ideologies it supports. This type of top-down reinforcement of static geographic knowledge is a far cry from the concept of civilian empowerment as understood in liberal democracies
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