GATOR: Requirements capturing of telephony features

We are developing a natural language-based, requirements gathering system called GATOR (for the GATherer Of Requirements). GATOR assists in the development of more accurate and complete specifications of new telephony features. GATOR interacts with a feature designer who describes a new feature, set of features, or capability to be implemented. The system aids this individual in the specification process by asking for clarifications when potential ambiguities are present, by identifying potential conflicts with other existing features, and by presenting its understanding of the feature to the designer. Through user interaction with a model of the existing telephony feature set, GATOR constructs a formal representation of the new, 'to be implemented' feature. Ultimately GATOR will produce a requirements document and will maintain an internal representation of this feature to aid in future design and specification. This paper consists of three sections that describe (1) the structure of GATOR, (2) POND, GATOR's internal knowledge representation language, and (3) current research issues

Mössbauer Studies of Nickel-Iron Hydrotalcites

Hydrotalcite-like Fe-Ni-hydroxides [Ni2/3IIFe1/3III(OH)2](CO3)1/6(H2O)y , [Ni3/4IIFe1/4III(OH)2]-(CO3)1/8(H2O)y and [Ni3/4II/IIIFe1/4III(OH)2](CO3)0.14(H20)y as well as the ternary oxide NaNi2/3Fe1/3O2 have been studied by 57Fe-Mössbauer spectroscopy. All samples contain Fe3+ in a high spin state. The quadrupole interaction is smaller if a magnetic splitting is present, which may indicate a non-parallel arrangement of the principal axis of the EFG and the hyperfine field. The temperature dependence of the spectra has been understood in terms of collective cluster excitations. In this model the magnetic energy of a single domain depends on the direction of the total magnetic moment and on magnetic interaction with the neighbourhood. The spectral lineshape could be fitted assum­ing uniaxial relaxation

Transmitters and receivers in SiGe BiCMOS technology for sensitive gas spectroscopy at 222 - 270 GHz

This paper presents transmitter and receiver components for a gas spectroscopy system. The components are fabricated in IHP's 0.13 μm SiGe BiCMOS technology. Two fractional-N phase-locked loops are used to generate dedicated frequency ramps for the transmitter and receiver and frequency shift keying for the transmitter. The signal-to-noise ratio (SNR) for the absorption line of gaseous methanol (CH 3 OH) at 247.6 GHz is used as measure for the performance of the system. The implemented mixer-first receiver allows a high performance of the system due to its linearity up to an input power of -10 dBm. Using a transmitter-array with an output power of 7 dBm an SNR of 4660 (integration time of 2 ms for each data point) was obtained for the 247.6 GHz absorption line of CH 3 OH at 5 Pa. We have extended our single frequency-band system for 228 - 252 GHz to a 2-band system to cover the range 222 - 270 GHz by combining corresponding two transmitters and receivers with the frequency bands 222 - 256 GHz and 250 - 270 GHz on single transmitter- and receiver-chips. This 2-band operation allows a parallel spectra acquisition and therefore a high flexibility of data acquisition for the two frequency-bands. The 50 GHz bandwidth allows for highly specific and selective gas sensing. © 2019 Author(s)

The Generation of Fullerenes

We describe an efficient new algorithm for the generation of fullerenes. Our implementation of this algorithm is more than 3.5 times faster than the previously fastest generator for fullerenes -- fullgen -- and the first program since fullgen to be useful for more than 100 vertices. We also note a programming error in fullgen that caused problems for 136 or more vertices. We tabulate the numbers of fullerenes and IPR fullerenes up to 400 vertices. We also check up to 316 vertices a conjecture of Barnette that cubic planar graphs with maximum face size 6 are hamiltonian and verify that the smallest counterexample to the spiral conjecture has 380 vertices.Comment: 21 pages; added a not

The chromosphere: gateway to the corona, or the purgatory of solar physics?

I argue that one should attempt to understand the solar chromosphere not only for its own sake, but also if one is interested in the physics of: the corona; astrophysical dynamos; space weather; partially ionized plasmas; heliospheric UV radiation; the transition region. I outline curious observations which I personally find puzzling and deserving of attention.Comment: To appear in the proceedings of the 25th NSO Workshop "Chromospheric Structure and Dynamics. From Old Wisdom to New Insights", Memorie della Societa' Astronomica Italiana, Eds. Tritschler et a

Mesostructured ZnO/Au nanoparticle composites with enhanced photocatalytic activity

Ease of catalyst separation from reaction mixtures represents a significant advantage in heterogeneous photocatalytic wastewater treatment. However, the activity of the catalyst strongly depends on its surface-to-volume ratio. Here, we present an approach based on cylindrical polybutadiene-block-poly(2-vinylpyridine) polymer brushes as template, which can be simultaneously loaded with zinc oxide (ZnO) and gold (Au) nanoparticles. Pyrolytic template removal of the polymer yields in mesostructured ZnO/Au composites, showing higher efficiencies in the photocatalytic degradation of ciprofloxacin and levofloxacin (generic antibiotics present in clinical wastewater) as compared to neat mesostructured ZnO. Upscaling of the presented catalyst is straightforward promising high technical relevance

Theory of Adsorption and Surfactant Effect of Sb on Ag (111)

We present first-principles studies of the adsorption of Sb and Ag on clean and Sb-covered Ag (111). For Sb, the {\it substitutional} adsorption site is found to be greatly favored with respect to on-surface fcc sites and to subsurface sites, so that a segregating surface alloy layer is formed. Adsorbed silver adatoms are more strongly bound on clean Ag(111) than on Sb-covered Ag. We propose that the experimentally reported surfactant effect of Sb is due to Sb adsorbates reducing the Ag adatom mobility. This gives rise to a high density of Ag islands which coalesce into regular layers.Comment: RevTeX 3.0, 11 pages, 0 figures] 13 July 199

The Challenge for Innovation in Direct Restorative Materials

During the past 50 years, a series of key UN conferences have established a framework to minimize human health risks from environmental exposures to key chemicals. In January 2013, more than 140 countries agreed to the text of new treaty to minimize Hg effects on the environment (the Minamata Convention). Dental caries is omnipresent around the globe, affecting 60% to 90% of school children and most adults, and producing discomfort that affects quality of life. Dental amalgam is frequently used to treat carious lesions and its use releases mercury into the environment. The best way to avoid the use of dental amalgam is to emphasize caries prevention. Alternatives to amalgam are suitable in some applications, but no replacement for amalgam has been found for large posterior restorations. For any restorative material, safety and environmental impacts are part of clinical risk assessment. Safety is freedom from unacceptable risks. Risk is a combination of probability of exposure and severity of harm. Best management practices are crucial to manage dental amalgam, but these impose additional that are disproportionately more for developing countries. The Minamata Convention seeks a phase-out of all mercury-based products except dental amalgam, where a phase-down is the present goal. For dentistry, the most important focus is the promotion of caries prevention and research on new materials