254 research outputs found

    Quantifying intelligence cooperation: The United States International Intelligence Behavior (USIIB) dataset

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    Cataloged from PDF version of article.This report describes the creation of the United States International Intelligence Behavior dataset (USIIB). The USIIB represents the first collection of event data specifically intended for exploring in a quantifiable manner the international intelligence cooperation behaviors of the United States. A total of 293,615 events are recorded in the USIIB, covering the years 2000–09. The report first provides a detailed description of the steps involved in building such a dataset, including the development of search terms, the use of a machine coding program (TABARI – Text Analysis by Augmenting Replacement Instructions) to extract data from wire news releases, and the extension of an existing coding scheme (CAMEO) to include intelligence behaviors. Following a discussion of issues related to the reliability and validity of event datasets in general and the USIIB in particular, the report then includes suggestions and examples for how the data in the current USIIB dataset may be used in order to add to our understandings of patterns and anomalies in international intelligence cooperation behavior. As a specific example, it offers results from an empirical test exploring variation in intelligence cooperation behaviors among democracies and non-democracies, asking specifically whether the United States has been more likely in the early 21st century to cooperate on intelligence matters with democratic states, and finding this not to have been the case. Finally, it aims to provide a guide for others who would like to extend this dataset to explore intelligence cooperation activity of other countries or regions

    Low temperature photoluminescence spectra of InS single crystals

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    Cataloged from PDF version of article.Photoluminescence (PL) spectra of InS were investigated in the wavelength region 477.5–860 nm and in the temperature range 8.5–293 K. We observed three PL bands centered at 605 nm (A-band), 626 nm (B-band) and 820 nm (C-band). The A- and B-bands are due to radiative transitions from the donor level at 0.01 eV below the bottom of the conduction band to the valence band and from the donor level at 0.06 eV below the bottom of the conduction band to the acceptor level 0.12 eV above the top of the valence band, respectively. The proposed energy-level scheme allows us to interpret the recombination processes in InS single crystals. Copyright © 1997 Published by Elsevier Ltd

    Price Promotion for Emotional Impact

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    Managers and academics often think of price promotions merely as incentives that entice consumers to accept offers that they might not have considered otherwise. Yet the prospect of paying a lower price for a product of given quality can also discourage deliberation, in a sense "dumbing down" the purchase encounter by making it less consequential. The authors examine this possibility in a dual-system theory of consumer behavior. Specifically, they argue that price promotion lowers a consumer's motivation to exert mental effort, in which case purchase decisions are guided less by extensive information processing and more by a quicker, easier, strong conditioner of preference: affect. Field data from a large daily deal company and four controlled experiments support this idea and document its implications primarily for product choice, in turn providing insight into the form and cause of brand switching that manufacturers and retailers can leverage to improve the allocation of promotional budgets and category management

    Trap levels in layered semiconductor Ga2SeS

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    Cataloged from PDF version of article.Trap levels in nominally undoped Ga2SeS layered crystals have been characterized by thermally stimulated current (TSC) measurements. During the measurements, current was allowed to flow along the c-axis of the crystals in the temperature range of 10-300 K. Two distinct TSC peaks were observed in the spectra, deconvolution of which yielded three peaks. The results are analyzed by curve fitting, peak shape and initial rise methods. They all seem to be in good agreement with each other. The activation energies of three trapping centers in Ga2SeS are found to be 72, 100 and 150 meV. The capture cross section of these traps are 6.7 x 10(-23), 1.8 x 10(-23) and 2.8 x 10(-22) cm(2) with concentrations of 1.3 x 10(12), 5.4 x 10(12) and 4.2 x 10(12) cm(-3), respectively. (C) 2004 Elsevier Ltd. All rights reserved

    Low dielectric constant Parylene-F-like films for intermetal dielectric applications

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    Cataloged from PDF version of article.We report on the dielectric properties and thermal stability of thin polymer films that art: suitable candidates for replacing silicon dioxide as the intermetal dielectric material in integrated circuits. Parylene-F-Iike films, (-CF2-C6H4-CF2-)(n), were produced by plasma deposition from a mixture of Ar and 1,4-bis(trifluoromethyl)benzene (CF3-C6H4-CF3) discharges and characterized using infrared absorption spectroscopy, spectroscopic ellipsometry, and capacitance measurements. The dielectric constant and the magnitude of the electronic and ionic contributions to the dielectric constant were determined through capacitance measurements and Kramers-Kronig analysis of the infrared absorption data. The film's dielectric constant ranges between 2 and 2.6 depending on the deposition conditions and the largest contribution to the dielectric constant is electronic. The films deposited at 300 degrees C are stable above 400 degrees C and further optimization could push this limit to as high as 500 degrees C. (C) 1999 American Institute of Physics

    Visible photoluminescence from planar amorphous silicon nitride microcavities

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    Fabry-Perot microcavities were used for the enhancement and inhibition of photoluminescence (PL) in a hydrogenated amorphous silicon nitride (a-SiNx:H) microcavity fabricated with and without ammonia. A planar microcavity was realized that included a metallic back mirror and an a-SiNx:H-air or a metallic front mirror. The PL extends from the red part of the spectrum to the near infrared for the samples grown without ammonia. The PL is in the blue-green part of the spectrum for the samples grown with ammonia. The PL amplitude is enhanced and the PL linewidth is reduced with respect to those in bulk a-SiNx:H. The numerically calculated transmittance, reflectance, and absorbance spectra agree well with the experimentally measured spectra. (C) 1998 Optical Society of America [S0740-3224(98)00211-2] OCIS codes: 230.5750, 250.5230, 310.0310

    Low temperature photoluminescence spectra of layered semiconductor TlGaS2

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    Cataloged from PDF version of article.Photoluminescence (PL) spectra of TlGaS2 layered single crystals were studied in the wavelength region 500-860 nm and in the temperature range 9.5-293 K. We observed a total of three PL bands centered at 568 nm (2.183 eV, A-band), 718 nm (1.727 eV, B-band) and 780 nm (1.590 eV, C-band) at various temperatures. We have also studied the variations of the A- and B-band intensities vs excitation laser density in the range from 7 × 10-2 to 9 W cm-2. The A- and B-bands were found to be due to radiative transitions from the deep donor levels located at 0.362 and 0.738 eV below the bottom of the conduction band to the shallow acceptor levels at 0.005 and 0.085 eV located above the top of the valence band, respectively. The proposed energy-level diagram permits us to interpret the recombination processes in TlGaS2 layered single crystals. © 1997 Elsevier Science Ltd

    Temperature dependence of the Raman-active phonon frequencies in indium sulfide

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    Cataloged from PDF version of article.The temperature dependence of the Raman-active mode frequencies in indium sulfide was measured in the range from 10 to 300 K. The analysis of the temperature dependence of the A(g) intralayer optical modes show that Raman frequency shift results from the change of harmonic frequency with volume expansion and anharmonic coupling to phonons of other branches. The pure-temperature contribution (phonon-phonon coupling) is due to three- and four-phonon processes. (C) 1999 Elsevier Science Ltd. All rights reserved

    Infrared luminescence of annealed germanosilicate layers

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    Cataloged from PDF version of article.In the light of growing importance of semiconductor nanocrystals for photonics, we report on the growth and characterization of annealed germanosilicate layers used for Ge nanocrystal formation. The films are grown using plasma enhanced chemical vapor deposition (PECVD) and post-annealed in nitrogen at temperatures between 600 and 1200 degrees C for as long as 2 h. Transmission electron microscopy (TEM), Raman scattering and photoluminescence spectroscopy (PL) has been used to characterize the samples both structurally and optically. Formation of Ge precipitates in the germanosilicate layers have been observed using Raman spectroscopy for a variety of PECVD growth parameters, annealing temperatures and times. Ge-Ge mode at similar to 300 cm(-1) is clearly observed at temperatures as low as 700 degrees C for annealing durations for 45 min. Raman results indicate that upon annealing for extended periods of time at temperatures above 900 degrees C; nanocrystals of few tens of nanometers in diameter inside the oxide matrix and precipitation and interdiffusion of Ge, forming SiGe alloy at the silicon and oxide interface take place. Low temperature PL spectroscopy has been used to observe luminescence from these samples in the vicinity of 1550 nm, an important wavelength for telecommunications. Observed luminescence quenches at 140 K. The photoluminescence data displays three peaks closely interrelated at approximately 1490,, 1530 and 1610 nm. PL spectra persist even after removing the oxide layer indicating that the origin of the infrared luminescent centers are not related to the Ge nanocrystals in the oxide layer. (C) 2013 Elsevier B.V. All rights reserved
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