17,626 research outputs found

    Tractability of multivariate problems for standard and linear information in the worst case setting: part II

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    We study QPT (quasi-polynomial tractability) in the worst case setting for linear tensor product problems defined over Hilbert spaces. We assume that the domain space is a reproducing kernel Hilbert space so that function values are well defined. We prove QPT for algorithms that use only function values under the three assumptions: 1) the minimal errors for the univariate case decay polynomially fast to zero, 2) the largest singular value for the univariate case is simple and 3) the eigenfunction corresponding to the largest singular value is a multiple of the function value at some point. The first two assumptions are necessary for QPT. The third assumption is necessary for QPT for some Hilbert spaces

    Being With Friends and the Potential for Binge Drinking During the First College Semester

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    In this prospective study, we assess the relationship between being with high school friends during the college transition and binge drinking. Across analyses (n = 489), the presence of high school friends during the college transition was associated with reduced binge drinking at the end of the first college semester among individuals at risk for this behavior because they drank in high school, associated alcohol use with the student role, or engaged in binge drinking at the beginning of the fall term. This is consistent with research linking social integration to behavioral regulation and suggests the presence of high school friends during the college transition serves as a source of social control at a juncture characterized by a reduction in normative constraint. Implications for practitioners seeking to assess new students\u27 risks for binge drinking and to more effectively meet the needs of vulnerable groups are discussed in relation to the study results

    Individual and Society: Sociological Social Psychology

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    Unlike the few other texts for undergraduate sociological social psychology courses that present 3 distinct traditions (or faces ) ... Symbolic Interactionist (SI), Social Structure and Personality (SSP), and Group Processes and Structure (GPS) by topic alone, this text initially discusses these faces by research tradition, and emphasizes the different theoretical frameworks within which social psychological analyses are conducted. With this approach, the authors make clear the link between face of sociological social psychology, theory, and methodology. And students gain an appreciably better understanding of the field of sociological social psychology; how and why social psychologists trained in sociology ask particular kinds of questions; the types of research they are involved in; and how their findings have been, or can be, applied to contemporary societal patterns and problems. Great writing makes this approach successful and interesting for students, resulting in a richer, more powerful course experience. A website offers instructors high quality support material, written by the authors, which you will appreciate and value -- Provided by publisher

    Code trolley: hardware-assisted control flow obfuscation

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    Many cybersecurity attacks rely on analyzing a binary executable to find exploitable sections of code. Code obfuscation is used to prevent attackers from reverse engineering these executables. In this work, we focus on control flow obfuscation - a technique that prevents attackers from statically determining which code segments are original, and which segments are added in to confuse attackers. We propose a RISC-V-based hardware-assisted deobfuscation technique that deobfuscates code at runtime based on a secret safely stored in hardware, along with an LLVM compiler extension for obfuscating binaries. Unlike conventional tools, our work does not rely on compiling hard-to-reverse-engineer code, but on securing a secret key. As such, it can be seen as a lightweight alternative to on-the-fly binary decryption.Published versio

    CodeTrolley: Hardware-Assisted Control Flow Obfuscation

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    Many cybersecurity attacks rely on analyzing a binary executable to find exploitable sections of code. Code obfuscation is used to prevent attackers from reverse engineering these executables. In this work, we focus on control flow obfuscation - a technique that prevents attackers from statically determining which code segments are original, and which segments are added in to confuse attackers. We propose a RISC-V-based hardware-assisted deobfuscation technique that deobfuscates code at runtime based on a secret safely stored in hardware, along with an LLVM compiler extension for obfuscating binaries. Unlike conventional tools, our work does not rely on compiling hard-to-reverse-engineer code, but on securing a secret key. As such, it can be seen as a lightweight alternative to on-the-fly binary decryption.Comment: 2019 Boston Area Architecture Workshop (BARC'19

    Single cell measurement of telomerase expression and splicing using microfluidic emulsion cultures.

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    Telomerase is a reverse transcriptase that maintains telomeres on the ends of chromosomes, allowing rapidly dividing cells to proliferate while avoiding senescence and apoptosis. Understanding telomerase gene expression and splicing at the single cell level could yield insights into the roles of telomerase during normal cell growth as well as cancer development. Here we use droplet-based single cell culture followed by single cell or colony transcript abundance analysis to investigate the relationship between cell growth and transcript abundance of the telomerase genes encoding the RNA component (hTR) and protein component (hTERT) as well as hTERT splicing. Jurkat and K562 cells were examined under normal cell culture conditions and during exposure to curcumin, a natural compound with anti-carcinogenic and telomerase activity-reducing properties. Individual cells predominantly express single hTERT splice variants, with the α+/β- variant exhibiting significant transcript abundance bimodality that is sustained through cell division. Sub-lethal curcumin exposure results in reduced bimodality of all hTERT splice variants and significant upregulation of alpha splicing, suggesting a possible role in cellular stress response. The single cell culture and transcript abundance analysis method presented here provides the tools necessary for multiparameter single cell analysis which will be critical for understanding phenotypes of heterogeneous cell populations, disease cell populations and their drug response

    Climate Effects on Rainfall Index Insurance Purchase Decisions

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    Rainfall Index insurance is a pilot insurance product offered to producers of hay and pasture in 9 states. This analysis examines the expected payoff of the RI insurance for bi-monthly periods based on rainfall shortage probabilities in alternative climate phases. Differences in expected returns indicate that selection of ENSO-specific optimal intervals may result in higher returns than those based on pooled rainfall series.rainfall insurance, ENSO, expected indemnity, Production Economics, Risk and Uncertainty,

    Determinants of Agricultural Disaster Payments in the Southeastern U.S.: County Level Analysis

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    Using county level data we study if weather and climate variables or variables used as proxies for rent-seeking behavior determine disaster payment in the Southeast. We do not find evidence of rent-seeking but find that, in addition to weather, long term climate variables affect disaster payments.Farm Management, Risk and Uncertainty,

    Design, Fabrication and Test of Multi-Fiber Laminates

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    Unidirectional and angleply multifiber laminates were tested for improved impact strength and other mechanical properties. The effects of several variables on the mechanical properties of epoxy matrix materials were described. These include fiber type (HMS and AS graphites, glass, and Kevlar 49), ratio of primary to hybridizing fiber and hybrid configuration. It is demonstrated that AS graphite/S glass in an intraply configuration results in the best combination of static and Charpy impact properties as well as superior ballistic impact resistance. Pendulum impact tests which were conducted on thin specimens are shown to produce different ranking of materials than tests conducted on standard thickness Charpy specimens. It is shown that the thin specimen results are in better agreement with the ballistic impact data. Additional static test data are reported as a function of temperature for the seven best hybrid configurations having epoxy, polyimide (PMR-15) and polyphenylquinoxaline resins as the matrix
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