60,673 research outputs found

    Stationary states in Langevin dynamics under asymmetric L\'evy noises

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    Properties of systems driven by white non-Gaussian noises can be very different from these systems driven by the white Gaussian noise. We investigate stationary probability densities for systems driven by α\alpha-stable L\'evy type noises, which provide natural extension to the Gaussian noise having however a new property mainly a possibility of being asymmetric. Stationary probability densities are examined for a particle moving in parabolic, quartic and in generic double well potential models subjected to the action of α\alpha-stable noises. Relevant solutions are constructed by methods of stochastic dynamics. In situations where analytical results are known they are compared with numerical results. Furthermore, the problem of estimation of the parameters of stationary densities is investigated.Comment: 9 pages, 9 figures, 3 table

    Design and Implementation of the UniProt Website

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    The UniProt consortium is the main provider of protein sequence and annotation data for much of the life sciences community. The "www.uniprot.org":http://www.uniprot.org website is the primary access point to this data and to documentation and basic tools for the data. This paper discusses the design and implementation of the new website, which was released in July 2008, and shows how it improves data access for users with different levels of experience, as well as to machines for programmatic access

    Guidelines for Effective Online Instruction Using Multimedia Screencasts

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    Using Case Work as a Pretest to Measure Crisis Leadership Preparedness

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    Today’s leaders must thrive in a world of turbulence and constant change. Unstable conditions frequently generate crises, emphasizing the need for crisis leadership preparedness, which is missing from many business curricula. Thus, the purpose of this work was to develop a learning module in crisis leadership preparedness. As a baseline measure or pretest, 217 graduate students were asked to analyze two crisis leadership cases during the first week of an entry leadership class. Content analysis provided the method to identify where student analyses fell short. These gaps in learning then informed the creation of student learning objectives. Applying inquiry-based learning, I then suggest instructional methods that I incorporated into an active learning module to better prepare today’s leaders for crisis leadership

    Risk and Machine Protection for Stored Magnetic and Beam Energies

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    Risk is a fundamental consideration when designing electronic systems. For most systems a view of risk can assist in setting design objectives, whereas both a qualitative and quantitative understanding of risk is mandatory when considering protection systems. This paper gives an overview of the risks due to stored magnetic and beam energies in high-energy physics, and shows how a risk-based approach can be used to design new systems mitigating these risks, using a lifecycle inspired by IEC 61508. Designing new systems in high-energy physics can be challenging as new and novel techniques are difficult to quantify and predict. This paper shows how the same lifecycle approach can be used in reverse to analyse existing systems, following their operation and first experiences.Comment: 19 pages, contribution to the 2014 CAS - CERN Accelerator School: Power Converters, Baden, Switzerland, 7-14 May 201

    Information Outlook, October 2003

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    Volume 7, Issue 10https://scholarworks.sjsu.edu/sla_io_2003/1009/thumbnail.jp

    The RAppArmor Package: Enforcing Security Policies in R Using Dynamic Sandboxing on Linux

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    The increasing availability of cloud computing and scientific super computers brings great potential for making R accessible through public or shared resources. This allows us to efficiently run code requiring lots of cycles and memory, or embed R functionality into, e.g., systems and web services. However some important security concerns need to be addressed before this can be put in production. The prime use case in the design of R has always been a single statistician running R on the local machine through the interactive console. Therefore the execution environment of R is entirely unrestricted, which could result in malicious behavior or excessive use of hardware resources in a shared environment. Properly securing an R process turns out to be a complex problem. We describe various approaches and illustrate potential issues using some of our personal experiences in hosting public web services. Finally we introduce the RAppArmor package: a Linux based reference implementation for dynamic sandboxing in R on the level of the operating system
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