3,374 research outputs found

    Telecommunications systems design techniques handbook

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    Handbook presents design and analysis of tracking, telemetry, and command functions utilized in these systems with particular emphasis on deep-space telecommunications. Antenna requirements are also discussed. Handbook provides number of tables outlining various performance criteria. Block diagrams and performance charts are also presented

    Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I

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    We have embarked on a project, under the aegis of the Nearby Stars (NStars)/ Space Interferometry Mission Preparatory Science Program to obtain spectra, spectral types, and, where feasible, basic physical parameters for the 3600 dwarf and giant stars earlier than M0 within 40 parsecs of the sun. In this paper we report on the results of this project for the first 664 stars in the northern hemisphere. These results include precise, homogeneous spectral types, basic physical parameters (including the effective temperature, surface gravity and the overall metallicity, [M/H]) and measures of the chromospheric activity of our program stars. Observed and derived data presented in this paper are also available on the project's website at http://stellar.phys.appstate.edu/

    OM4 LONG-TERM COST-EFFECTIVENESS OF A DIABETES RISK SCORE IN CLINICAL PRACTICE

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    Physical aspects of oracles for randomness, and Hadamard's conjecture

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    We analyze the physical aspects and origins of currently proposed oracles for (absolute) randomness.Comment: 10 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1405.140

    Not Merely Experiential: Unconscious Thought Can Be Rational

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    Individuals often form more reasonable judgments from complex information after a period of distraction vs. deliberation. This phenomenon has been attributed to sophisticated unconscious thought during the distraction period that integrates and organizes the information (Unconscious Thought Theory; Dijksterhuis and Nordgren, 2006). Yet, other research suggests that experiential processes are strengthened during the distraction (relative to deliberation) period, accounting for the judgment and decision benefit. We tested between these possibilities, hypothesizing that unconscious thought is distinct from experiential processes, and independently contributes to judgments and decisions during a distraction period. Using an established paradigm, Experiment 1 (N = 319) randomly induced participants into an experiential or rational mindset, after which participants received complex information describing three roommates to then consider consciously (i.e., deliberation) or unconsciously (i.e., distraction). Results revealed superior roommate judgments (but not choices) following distraction vs. deliberation, consistent with Unconscious Thought Theory. Mindset did not have an influence on roommate judgments. However, planned tests revealed a significant advantage of distraction only within the rational-mindset condition, which is contrary to the idea that experiential processing alone facilitates complex decision-making during periods of distraction. In a second experiment (N = 136), we tested whether effects of unconscious thought manifest for a complex analytical reasoning task for which experiential processing would offer no advantage. As predicted, participants in an unconscious thought condition outperformed participants in a control condition, suggesting that unconscious thought can be analytical. In sum, the current results support the existence of unconscious thinking processes that are distinct from experiential processes, and can be rational. Thus, the experiential vs. rational nature of a process might not cleanly delineate conscious and unconscious thought

    Mobile Element Studies in Rocks (RAT) from Columbia Hills/West Spur at Gusev

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    Using elemental abundances determined by SPIRIT APX spectrometer on rocks and soils at Gusev Plains and Columbia Hills/ West Spur regions, the Athena Team discussed the aqueous geochemical implications at these sites on Mars. They suggested that these rocks were exposed to variable degrees of aqueous alteration (low to high) at Gusev crater. Earlier, we developed analytical procedures for studying aqueous geochemical behavior of fluids on rocks at Meridiani. In the present study, we apply these methods to rocks at Columbia Hills/West Spur in order to understand the significance of the Gusev rock results in reference to aqueous geochemical processes on Mars . The data analysis procedure is based on treating SO3 ("a") and Cl ("b") as two variables and tracking the relationship between "a" and "b" when the fluids undergo evaporation. This process of evaporation leads to concentration changes in these two elements finally producing salt assemblages on Martian rocks. In some cases on plotting "a"/ "b" versus "b" in salt assemblages, they yield a hyperbolic distribution. The relationship is transformed into a straight line when "a"/"b" is again plotted against 1/"b" in the system. Earlier, we used this procedure in the case of Merdiani rock abrasion tool (RAT) rocks and in this study, we discuss the application of this procedure to Gusev rocks. This study shows that the Gusev Plains rocks were exposed to low SO3/Cl solutions (sulfate-poor) for short period of time (weak interaction), whereas solutions with high SO3/Cl ratios (sulfate-rich) seem to have pervasively interacted with Columbia Hills/ West Spur rocks (strong interaction) at Gusev crater. Our conclusions seem to be consistent with the Mossbauer results given for these rock

    Isotopic Evidence for a Martian Regolith Component in Martian Meteorites

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    Noble gas measurements in gas-rich impact-melt (GRIM) glasses in EET79001 shergottite showed that their elemental and isotopic composition is similar to that of the Martian atmosphere [1-3]. The GRIM glasses contain large amounts of Martian atmospheric gases. Those measurements further suggested that the Kr isotopic composition of Martian atmosphere is approximately similar to that of solar Kr. The (80)Kr(sub n) - (80)Kr(sub M) mixing ratio in the Martian atmosphere reported here is approximately 3%. These neutron-capture reactions presumably occurred in the glass-precursor regolith materials containing Sm- and Br- bearing mineral phases near the EET79001/ Shergotty sites on Mars. The irradiated materials were mobilized into host rock voids either during shock-melting or possibly by earlier aeolian / fluvial activity
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