2,116 research outputs found

    Strange Quark Contribution to the Nucleon Spin from Electroweak Elastic Scattering Data

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    The total contribution of strange quarks to the intrinsic spin of the nucleon can be determined from a measurement of the strange-quark contribution to the nucleon's elastic axial form factor. We have studied the strangeness contribution to the elastic vector and axial form factors of the nucleon, using elastic electroweak scattering data. Specifically, we combine elastic νp\nu p and νˉp\bar{\nu} p scattering cross section data from the Brookhaven E734 experiment with elastic epep and quasi-elastic eded and ee-4^4He scattering parity-violating asymmetry data from the SAMPLE, HAPPEx, G0 and PVA4 experiments. We have not only determined these form factors at individual values of momentum-transfer (Q2Q^2), but also have fit the Q2Q^2-dependence of these form factors using simple functional forms. We present the results of these fits, along with some expectations of how our knowledge of these form factors can be improved with data from Fermilab experiments.Comment: 3 pages, 1 figure, CIPANP 201

    "If You Can't Beat them, Join them": A Usability Approach to Interdependent Privacy in Cloud Apps

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    Cloud storage services, like Dropbox and Google Drive, have growing ecosystems of 3rd party apps that are designed to work with users' cloud files. Such apps often request full access to users' files, including files shared with collaborators. Hence, whenever a user grants access to a new vendor, she is inflicting a privacy loss on herself and on her collaborators too. Based on analyzing a real dataset of 183 Google Drive users and 131 third party apps, we discover that collaborators inflict a privacy loss which is at least 39% higher than what users themselves cause. We take a step toward minimizing this loss by introducing the concept of History-based decisions. Simply put, users are informed at decision time about the vendors which have been previously granted access to their data. Thus, they can reduce their privacy loss by not installing apps from new vendors whenever possible. Next, we realize this concept by introducing a new privacy indicator, which can be integrated within the cloud apps' authorization interface. Via a web experiment with 141 participants recruited from CrowdFlower, we show that our privacy indicator can significantly increase the user's likelihood of choosing the app that minimizes her privacy loss. Finally, we explore the network effect of History-based decisions via a simulation on top of large collaboration networks. We demonstrate that adopting such a decision-making process is capable of reducing the growth of users' privacy loss by 70% in a Google Drive-based network and by 40% in an author collaboration network. This is despite the fact that we neither assume that users cooperate nor that they exhibit altruistic behavior. To our knowledge, our work is the first to provide quantifiable evidence of the privacy risk that collaborators pose in cloud apps. We are also the first to mitigate this problem via a usable privacy approach.Comment: Authors' extended version of the paper published at CODASPY 201

    Hat hier jemand gesagt, der Kaiser sei nackt? Eine Verteidigung der Geussschen Kritik an Rawls? idealtheoretischem Ansatz [?Did Somebody Just Say the Emperor is Naked? In Defence of Geuss's Objections to Rawls's Ideal-Theoretical Approach?]

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    In this paper, we take up two objections Raymond Geuss levels against John Rawls? ideal theory in Philosophy and Real Politics. We show that, despite their fundamental disagreements, the two theorists share a common starting point: they both (a) reject doing political philosophy by way of applying an independently derived moral theory; and (b) grapple with the danger of unduly privileging the status quo. However, neither Rawls? characterization of politics nor his ideal theoretical approach as response to the aforementioned danger is adequate or so we argue. Moreover, contrary to received opinion, Geuss? political philosophy is the more reflective and the more philosophical of the two. In a final section, we highlight another agreement: both think that political philosophers should develop conceptual innovations as a way of clarifying and overcoming practical problems. We demonstrate that Geuss could offer a number of reasons for finding Rawls? conceptual innovations wanting

    Approximate roots of a valuation and the Pierce-Birkhoff Conjecture

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    This paper is a step in our program for proving the Piece-Birkhoff Conjecture for regular rings of any dimension (this would contain, in particular, the classical Pierce-Birkhoff conjecture which deals with polynomial rings over a real closed field). We first recall the Connectedness and the Definable Connectedness conjectures, both of which imply the Pierce - Birkhoff conjecture. Then we introduce the notion of a system of approximate roots of a valuation v on a ring A (that is, a collection Q of elements of A such that every v-ideal is generated by products of elements of Q). We use approximate roots to give explicit formulae for sets in the real spectrum of A which we strongly believe to satisfy the conclusion of the Definable Connectedness conjecture. We prove this claim in the special case of dimension 2. This proves the Pierce-Birkhoff conjecture for arbitrary regular 2-dimensional rings

    Collaborating beyond the Campus: University Librarians in the K-12 Classroom

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    The challenge of developing information literate college students begins long before freshmen enter the university classroom. However as tight budgets force many K-12 districts to cut important information resources, many high school graduates may be missing foundational research skills when they arrive on campus. This presentation will detail an ongoing collaboration between academic librarians, an education professor, public librarians, and a middle school teacher to help fill this gap by providing basic information literacy workshops for sixth-grade students. In weekly workshops the sixth-graders work alongside university education majors to develop research questions, locate information, evaluate sources, and integrate findings into presentations; these are then showcased each semester in an exhibition event on the university campus. The presenters, two academic librarians and an education professor, will discuss the process of collaborating on this initiative, changes and improvements to the workshop curriculum, and a multi-faceted approach to assessment. Attendees will be able to identify methods of engaging both middle school and university students with research skills, and discover new ideas about how to move collaborative information literacy initiatives beyond the campus and into the community

    AutoFolio: An Automatically Configured Algorithm Selector (Extended Abstract)

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    Article in monograph or in proceedingsLeiden Inst Advanced Computer Science

    AutoFolio: An Automatically Configured Algorithm Selector (Extended Abstract)

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    Article in monograph or in proceedingsLeiden Inst Advanced Computer Science
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