University of California, Santa Barbara

About: University of California, Santa Barbara is a education organization based out in Santa Barbara, California, United States. It is known for research contribution in the topics: Population & Laser. The organization has 30281 authors who have published 80852 publications receiving 4626827 citations. The organization is also known as: UC Santa Barbara & UCSB.

Anomaly detection of web-based attacks

Abstract: Web-based vulnerabilities represent a substantial portion of the security exposures of computer networks. In order to detect known web-based attacks, misuse detection systems are equipped with a large number of signatures. Unfortunately, it is difficult to keep up with the daily disclosure of web-related vulnerabilities, and, in addition, vulnerabilities may be introduced by installation-specific web-based applications. Therefore, misuse detection systems should be complemented with anomaly detection systems. This paper presents an intrusion detection system that uses a number of different anomaly detection techniques to detect attacks against web servers and web-based applications. The system correlates the server-side programs referenced by client queries with the parameters contained in these queries. The application-specific characteristics of the parameters allow the system to perform focused analysis and produce a reduced number of false positives. The system derives automatically the parameter profiles associated with web applications (e.g., length and structure of parameters) from the analyzed data. Therefore, it can be deployed in very different application environments without having to perform time-consuming tuning and configuration.

Evidence for an excess of B̄→D( *)τ -ν ̄τ decays

Abstract: Based on the full BaBar data sample, we report improved measurements of the ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B -> D(*) l Nu), where l is either e or mu. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D) = 0.440 +- 0.058 +- 0.042 and R(D*) = 0.332 +- 0.024 +- 0.018, which exceed the Standard Model expectations by 2.0 sigma and 2.7 sigma, respectively. Taken together, our results disagree with these expectations at the 3.4 sigma level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model. We also report the observation of the decay B -> D Tau Nu, with a significance of 6.8 sigma.

Exciton diffusion in organic semiconductors

Abstract: The purpose of this review is to provide a basic physical description of the exciton diffusion in organic semiconductors. Furthermore, experimental methods that are used to measure the key parameters of this process as well as strategies to manipulate the exciton diffusion length are summarized. Special attention is devoted to the temperature dependence of exciton diffusion and its relationship to Forster energy transfer rates. An extensive table of more than a hundred measurements of the exciton diffusion length in various organic semiconductors is presented. Finally, an outlook of remaining challenges for future research is provided.

Nonvisual navigation by blind and sighted: assessment of path integration ability

Abstract: Blindfolded sighted, adventitiously blind, and congenitally blind subjects performed a set of navigation tasks. The more complex tasks involved spatial inference and included retracing a multisegment route in reverse, returning directly to an origin after being led over linear segments, and pointing to targets after locomotion. As a group, subjects responded systematically to route manipulations in the complex tasks, but performance was poor. Patterns of error and response latency are informative about the internal representation used; in particular, they do not support the hypothesis that only a representation of the origin of locomotion is maintained. The slight performance differences between groups varying in visual experience were neither large nor consistent across tasks. Results provide little indication that spatial competence strongly depends on prior visual experience.

General Predictive Syntheses of Cubic, Hexagonal, and Lamellar Silica and Titania Mesostructured Thin Films§

Abstract: Well-ordered mesostructured silica and titania films were prepared using poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide) triblock copolymer species (Pluronic P123) as the structure-directing agents. By varying the volume ratio between the copolymer and inorganic components of the precursor solution, silica and titania thin films with cubic, 2D hexagonal, and lamellar mesostructures were prepared. The regions over which the three phases were obtained correspond well with those of the water−block copolymer binary phase diagram when considered in terms of the volume fraction of copolymer incorporated. In particular, a cubic mesostructure with crystalline TiO2 (anatase) in the walls, stable to 400 °C, was synthesized.