SRI International

About: SRI International is a nonprofit organization based out in Menlo Park, California, United States. It is known for research contribution in the topics: Ionosphere & Laser. The organization has 7222 authors who have published 13102 publications receiving 660724 citations. The organization is also known as: Stanford Research Institute & SRI.

Longitudinal changes in cognition, gait, and balance in abstinent and relapsed alcoholic men: relationships to changes in brain structure.

Abstract: Chronic alcoholism is associated with cognitive and motor deficits, and there is evidence for reversibility with sobriety. Alcoholic men were examined after 1 month of sobriety and 2 to 12 months later with cognitive and motor tests and magnetic resonance imaging. In this naturalistic study, 20 alcoholic participants had abstained and 22 had resumed drinking at retesting. Abstainers sustained greater improvement than relapsers on tests of delayed recall of drawings, visuospatial function, attention, gait, and balance. Shrinkage in 3rd ventricle volume across all participants significantly correlated with improvement in nonverbal short-term memory. Additional brain structure-function relationships, most involving short-term memory, were observed when analyses were restricted to alcoholic men who had maintained complete abstinence, were light relapsers for at least 3 months, or had consumed no more than 10 drinks prior to follow-up testing. Thus, alcoholic men who maintain abstinence can show substantial functional improvement that is related to improvement in brain structure condition.

Field ionizer and field emission cathode structures and methods of production

Abstract: Field-forming devices primarily useful as field ionizers and field emission cathodes and having as a basic element an array of closely spaced cones with sharp points supported on a substrate (in the most usual case conductive or semiconductive) are disclosed. Preferably, the field-forming structure is completed by a screen-like structure, e.g. as fine mesh screen, insulatively supported above the points with the center of apertures in the screen substantially aligned with the longitudinal axis of corresponding cones. A novel method of forming such structures includes placing a screen with a mesh corresponding to the desired number and packing density of sharp conical points in close proximity to, or in contact with, the substrate and projecting material through the screen onto the substrate whereby sharp cones of the material are formed on the substrates.

Spin dynamics in magnets: Equation of motion and finite temperature effects.

Abstract: General equations of motion are introduced for the evaluation of spin dynamics in magnetic materials. The theory uses the adiabatic separation of diagonal and off-diagonal components of the spin density matrix. This adiabatic approach considers the orientation of the local magnetic moments to be slowly varying relative to their magnitudes. The angles of the magnetization density are introduced as collective variables in density functional theory. The equations and technique can be simultaneously combined with those of first-principles molecular dynamics for the consistent treatment of spin-lattice interactions. Stochastic and deterministic approaches for treating finite temperature effects are introduced for such dynamics. The method is implemented within the local density approximation and applied to \ensuremath{\gamma}-Fe, a frustrated system where we obtain additional low-energy magnetic configurations. \textcopyright{} 1996 The American Physical Society.

DroidMiner: Automated Mining and Characterization of Fine-grained Malicious Behaviors in Android Applications

Abstract: Most existing malicious Android app detection approaches rely on manually selected detection heuristics, features, and models. In this paper, we describe a new, complementary system, called DroidMiner, which uses static analysis to automatically mine malicious program logic from known Android malware, abstracts this logic into a sequence of threat modalities, and then seeks out these threat modality patterns in other unknown (or newly published) Android apps. We formalize a two-level behavioral graph representation used to capture Android app program logic, and design new techniques to identify and label elements of the graph that capture malicious behavioral patterns (or malicious modalities). After the automatic learning of these malicious behavioral models, DroidMiner can scan a new Android app to (i) determine whether it contains malicious modalities, (ii) diagnose the malware family to which it is most closely associated, (iii) and provide further evidence as to why the app is considered to be malicious by including a concise description of identified malicious behaviors. We evaluate DroidMiner using 2,466 malicious apps, identified from a corpus of over 67,000 third-party market Android apps, plus an additional set of over 10,000 official market Android apps. Using this set of real-world apps, we demonstrate that DroidMiner achieves a 95.3% detection rate, with only a 0.4% false positive rate. We further evaluate DroidMiner’s ability to classify malicious apps under their proper family labels, and measure its label accuracy at 92%.

To ‘errrr’ is human: ecology and acoustics of speech disfluencies

Abstract: Unlike read or laboratory speech, spontaneous speech contains high rates of disuencies (e.g. repetitions, repairs, ®lled pauses, false starts). This paper aims to promotedisuency awareness' especially in the ®eld of phonetics ± which has much to offer in the way of increasing our understanding of these phenomena. Two broad claims are made, based on analyses of disuencies in different corpora of spontaneous American English speech. First, an Ecology Claim suggests that disuencies are related to aspects of the speaking environments in which they arise. The claim is supported by evidence from task effects, location analyses, speaker effects and sociolinguistic effects. Second, an Acoustics Claim argues that disuency has consequences for phonetic and prosodic aspects of speech that are not represented in the speech patterns of laboratory speech. Such effects include modi®cations in segment durations, intonation, voice quality, vowel quality and coarticulation patterns. The ecological and acoustic evidence provide insights about human language production in real-world contexts. Such evidence can also guide methods for the processing of spontaneous speech in automatic speech recognition applications.