3,970 research outputs found
WIMPs search by scintillators: possible strategy for annual modulation search with large-mass highly-radiopure NaI(Tl)
The DAMA experiments are running deep underground in the Gran Sasso National
Laboratory. Several interesting results have been achieved so far. Here a
maximum likelihood method to search for the WIMP annual modulation signature is
discussed and applied to a set of preliminary test data collected with large
mass highly radiopure NaI(Tl) detectors. Various related technical arguments
are briefly addressed.Comment: 6 pages, 4 figures, LaTex. Contributed paper to TAUP97; to appear in
the Proceeding
Assessing the feasibility of a life history calendar to measure HIV risk and health in older South Africans
Life history calendars capture patterns of behavior over time, uncovering transitions and trajectories. Despite the growing numbers of older persons living with HIV in southern Africa, little is known about how HIV testing and risk unfold in this population. Operationalizing a life course approach with the use of an innovative Testing and Risk History Calendar [TRHC], we collected pilot data on older South Africans’ risk and HIV testing. We found older persons were able to provide (1) reference points to facilitate recall over a 10-year period, (2) specifics about HIV tests during that decade, and (3) details that contextualize the testing data, such as living arrangements, relationships, and health status. Interviewer debriefing sessions after each interview captured information on context and links across domains. On a larger scale, the TRHC has potential to reveal pathways between sexual behavior, HIV testing and risk perception, and health at older ages
Mutation of Directed Graphs -- Corresponding Regular Expressions and Complexity of Their Generation
Directed graphs (DG), interpreted as state transition diagrams, are
traditionally used to represent finite-state automata (FSA). In the context of
formal languages, both FSA and regular expressions (RE) are equivalent in that
they accept and generate, respectively, type-3 (regular) languages. Based on
our previous work, this paper analyzes effects of graph manipulations on
corresponding RE. In this present, starting stage we assume that the DG under
consideration contains no cycles. Graph manipulation is performed by deleting
or inserting of nodes or arcs. Combined and/or multiple application of these
basic operators enable a great variety of transformations of DG (and
corresponding RE) that can be seen as mutants of the original DG (and
corresponding RE). DG are popular for modeling complex systems; however they
easily become intractable if the system under consideration is complex and/or
large. In such situations, we propose to switch to corresponding RE in order to
benefit from their compact format for modeling and algebraic operations for
analysis. The results of the study are of great potential interest to mutation
testing
Memory Gaps in the American Time Use Survey. Investigating the Role of Retrieval Cues and Respondents’ Level of Effort
Unaccounted respondent memory gasp- i.e., those activity gaps that are attributed by interviewers to respondents\u27 memory failure- have serious implications for data quality. We contribute to the existing literature by investigating interviewing dynamics using paradata, distinguishing temporary memory gaps, which can be resolved during the interview, from enduring memory gaps, which cannot be resolved. We investigate factors that are associated with both kinds of memory gaps and how different response strategies are associated with data quality. We investigate two hypotheses that are associated with temporary and enduring memory gaps. The motivated cuing hypothesis posits that respondents who display more behaviors related to the presence and use of retrieval cues throughout the survey will resolve temporary memory gaps more successfully compared to respondents displaying fewer such behaviors. This should result in overall lower levels of enduring memory gaps. The lack of effort hypothesis suggests that respondent who are less eager to participate in the survey will expend less cognitive effort to resolve temporary memory gaps compared to more motivated respondents. This should then result in a positive association with enduring memory gaps and no association with temporary memory gaps. Using survey and paradata from the 2010 ATUS, our analyses indicate that, as hypothesized, behaviors indicating the use of retrieval cues are positively associated with temporary memory gaps and negatively associated with enduring memory gaps. Motivated respondents experiencing memory difficulties overcome what otherwise would result in enduring memory gaps more successfully compared to other respondents. Indicators of lack of effort, such as whether or not the respondent initially refused to participate in the survey, are positively associated with enduring memory gaps suggesting that reluctant respondents do not resolve memory gaps. The paper concludes with a discussion of implications for survey research
DAMA annual modulation effect and asymmetric mirror matter
The long-standing model-independent annual modulation effect measured by DAMA
Collaboration is examined in the context of asymmetric mirror dark matter,
assuming that dark atoms interact with target nuclei in the detector via
kinetic mixing between mirror and ordinary photons, both being massless. The
relevant ranges for the kinetic mixing parameter are obtained taking into
account various existing uncertainties in nuclear and particle physics
quantities as well as characteristic density and velocity distributions of dark
matter in different halo models.Comment: 27 pages, 5 figures, 2 tables; version in publication on Eur. Phys.
J.
Observations of annual modulation in direct detection of relic particles and light neutralinos
The long-standing model-independent annual modulation effect measured by the
DAMA Collaboration, which fulfills all the requirements of a dark matter annual
modulation signature, and the new result by the CoGeNT experiment that shows a
similar behavior are comparatively examined under the hypothesis of a dark
matter candidate particle interacting with the detectors' nuclei by a coherent
elastic process. The ensuing physical regions in the plane of the dark
matter-particle mass versus the dark matter-particle nucleon cross-section are
derived for various galactic halo models and by taking into account the impact
of various experimental uncertainties. It is shown that the DAMA and the CoGeNT
regions agree well between each other and are well fitted by a supersymmetric
model with light neutralinos which satisfies all available experimental
constraints, including the most recent results from CMS and ATLAS at the CERN
Large Hadron Collider.Comment: 13 pages, 7 figure
Depletion-induced biaxial nematic states of boardlike particles
With the aim of investigating the stability conditions of biaxial nematic
liquid crystals, we study the effect of adding a non-adsorbing ideal depletant
on the phase behavior of colloidal hard boardlike particles. We take into
account the presence of the depletant by introducing an effective depletion
attraction between a pair of boardlike particles. At fixed depletant fugacity,
the stable liquid crystal phase is determined through a mean-field theory with
restricted orientations. Interestingly, we predict that for slightly elongated
boardlike particles a critical depletant density exists, where the system
undergoes a direct transition from an isotropic liquid to a biaxial nematic
phase. As a consequence, by tuning the depletant density, an easy experimental
control parameter, one can stabilize states of high biaxial nematic order even
when these states are unstable for pure systems of boardlike particles
An Exploratory High-Density EEG Investigation of the Misinformation Effect: Attentional and Recollective Differences between True and False Perceptual Memories
The misinformation effect, a phenomenon in which eyewitness memories are altered via exposure to post-event misinformation, is one of the most important paradigms used to investigate the reconstructive nature of human memory. The aim of this study was to use the misinformation effect paradigm to investigate differences in attentional and recollective processing between true and false event memories. Nineteen participants completed a variant of the misinformation paradigm in which recognition responses to true and misinformation based event details embedded within a narrative context, were investigated using high-density (256-channel) EEG with a 1-day delay between event exposure and test. Source monitoring responses were used to isolate event-related-potentials (ERPs) associated with perceptual (i.e. event) source attributions. Temporal-spatial analyses of these ERPs showed evidence of an elevated P3b and Late-Positive Component, associated with stronger context-matching responses and recollective activity respectively, in true perceptual memories relative to false misinformation based ones. These findings represent the first retrieval focused EEG investigation of the misinformation effect and highlight the interplay between attention and retrieval processes in episodic memory recognition
Charge dynamics of a single donor coupled to a few electrons quantum dot in silicon
We study the charge transfer dynamics between a silicon quantum dot and an
individual phosphorous donor using the conduction through the quantum dot as a
probe for the donor ionization state. We use a silicon n-MOSFET (metal oxide
field effect transistor) biased near threshold in the SET regime with two side
gates to control both the device conductance and the donor charge. Temperature
and magnetic field independent tunneling time is measured. We measure the
statistics of the transfer of electrons observed when the ground state D0 of
the donor is aligned with the SET states
Representasi Pesan Moral dalam Film Rudy Habibie Karya Hanung Bramantyo (Analisis Semiotika Roland Barthes)
The research entitled moral representation in the movie hanung bramantyo habibie rudy the works (analysis of semiotic roland barthes). The story of the film in the true story of young man named baharudin jusuf habibie who tried to create an aircraft as well as build the aerospace industry Indonesia. Inu research aims to find out how the moral messages in the film rudy habibie presented which then generate moral as human relationships with humans, the relationship of man with god, as well as human relationships the social environment.This study uses qualitative methods, with Roland Barthes semiotics analysis approach, taking a subject that is focused upon the character rudy. With views through faceted Denoted (signifier) describes the relationship of signifier and signified on reality, meaning explicit. Connotation (signified) describes the relationship of signifier and signified to non-reality, generate an implicit meaning and myth (the myth) explained the habits and beliefs prevailing in the society. In this study the scene is divided into 3 parts namely the relationship of man with man, the human relationship with the social environment with 11 scene data analysis unit. Data collection with the corpus contained in the film in accordance with the categorization of the already determined.The results of this research show that the representation of the moral messages in the film rudy this is habibie. First, look at human relationships with humans. Second, look at the relationship of man with god. Third, look at human relationships with the people in the social environment
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