Hewlett-Packard

About: Hewlett-Packard is a company organization based out in Palo Alto, California, United States. It is known for research contribution in the topics: Signal & Substrate (printing). The organization has 34663 authors who have published 59808 publications receiving 1467218 citations. The organization is also known as: Hewlett Packard & Hewlett-Packard Company.

Standard solar models and the uncertainties in predicted capture rates of solar neutrinos

Abstract: caused by a specified uncertainty in any of the parameters is evaluated with the aid of a series of standard solar models that were constructed for this purpose; the results are expressed in terms of the logarithmic partial derivative of each flux with respect to each parameter. The effects on the neutrino fluxes of changing individual parameters by large amounts can usually be estimated to satisfactory accuracy by making use of the tabulated partial derivatives. An overall "effective 3o. level of uncertainty" is defined using the requirement that the true value should lie within the estimated range unless someone has made a mistake. Effective 3o. levels of uncertainty, as well as best estimates, are determined for the following possible detectors of solar neutrinos: H, Li, Cl, 'Ga, Br, 'Br, Mo, Mo, ' In, and electronneutrino scattering. The most important sources of uncertainty in the predicted capture rates are identified and discussed for each detector separately. For the Cl detector, the predicted capture rate is 7.6+3.3 (effective 3o. errors) SNU. The measured production rate is (Cleveland, Davis, and Rowjley, 1981) 2. 1+0.3 SNU ( lo. error). For a 'Ga detector, the expected capture rate is 106(1+o08) SNU (also effective 3o. errors). The relatively small uncertainty quoted for the Ga detector is a direct result of the fact that 'Ga is primarily sensitive to neutrinos from the basic proton-proton reaction, the rate of which is determined largely by the observed solar luminosity. The Caltech and Munster measured values for the cross-section factor for the reaction He(a, y) Be are inconsistent with each other. The capture rates quoted above were obtained using the Caltech value for the cross-section factor. If the Munster value is used instead, then the predicted capture rate for the Cl experiment is 4.95+ 2. 1 SNU (effective 3o. errors) and, for the 'Ga experiment, 96.7 (1 ~&o8} SNU (effective 3o. errors). In order for the bestestimate value to agree with the observation of Davis (1978) of 2 SNU for the Cl experiment, the cross-section factor S34 (0) would have to be reduced by about 15o. to less than the Caltech value, i.e. to 7o. less than the Munster value. The characteristics of the standard solar model, constructed with the best available nuclear parameters, solar opacity, and equation of state, are presented in detail. The computational methods by which this and similar models were obtained are also described brieAy. The primordial helium abundance inferred with the aid of standard solar models is Y = 0.25+ 0.01. The complementary relation between observations of solar neutrinos and of the normal modes of oscillation of the sun is examined. It is shown that the splitting of the observed large-n, small-l, p-mode (five minute) oscillations of the sun primarily originates in the outer ten percent of the solar mass, while the neutrinos from B beta decay originate primarily in the inner five percent of the solar mass. The solar luminosity, and the flux of neutrinos from the proton-proton reaction, come mostly from an intermediate region.

The triangle processor and normal vector shader: a VLSI system for high performance graphics

Abstract: Current affordable architectures for high-speed display of shaded 3D objects operate orders of magnitude too slowly. Recent advances in floating point chip technology have outpaced polygon fill time, making the memory access bottleneck between the drawing processor and the frame buffer the most significant factor to be accelerated. Massively parallel VLSI system have the potential to bypass this bottleneck, but to date only at very high cost. We describe a new more affordable VLSI solution. A pipeline of triangle processors rasterizes the geometry, then a further pipeline of shading processors applies Phong shading with multiple light sources. The triangle processor pipeline performs 100 billion additions per second, and the shading pipeline performs two billion multiplies per second. This allows 3D graphics systems to be built capable of displaying more than one million triangles per second. We show the results of an anti-aliasing technique, and discuss extensions to texture mapping, shadows, and environment maps.

Analysis of Oligonucleotides by HPLC-Electrospray Ionization Mass Spectrometry.

Abstract: A new interface procedure has been developed that allows, for the first time, the high-efficiency analysis of synthetic oligonucleotides up to 75 bases by reversed-phase HPLC and on-line electrospray ionization mass spectrometry. For oligonucleotides up to 30 bases in length, single-base resolution can be obtained with low levels of cation adduct formation in the negative ion electrospray mass spectra. A key part of the method uses 1,1,1,3,3,3-hexafluoro-2-propanol as an additive to the HPLC mobile phase, adjusted to pH 7.0 with triethylamine. This novel additive results in both good HPLC separation and efficient electrospray ionization. The broad potential of this new method is demonstrated for synthetic homopolymers of thymidine (PolyT), fragments based on the pBR322 plasmid sequence, and phosphorothioate ester antisense oligonucleotides. This approach will be of particular utility for the characterization of DNA probes and PCR primers and quality control of antisense compounds such as phosphorothioates...

SPARQL basic graph pattern optimization using selectivity estimation

Abstract: In this paper, we formalize the problem of Basic Graph Pattern (BGP) optimization for SPARQL queries and main memory graph implementations of RDF data. We define and analyze the characteristics of heuristics for selectivity-based static BGP optimization. The heuristics range from simple triple pattern variable counting to more sophisticated selectivity estimation techniques. Customized summary statistics for RDF data enable the selectivity estimation of joined triple patterns and the development of efficient heuristics. Using the Lehigh University Benchmark (LUBM), we evaluate the performance of the heuristics for the queries provided by the LUBM and discuss some of them in more details.

Applying electric field sensing to human-computer interfaces

Abstract: A non-contact sensor based on the interaction of a person with electric fields for human-computer interface is investigated. Two sensing modes are explored: an external electric field shunted to ground through a human body, and an external electric field transmitted through a human body to stationary receivers. The sensors are low power (milliwatts), high resolution (millimeter) low cost (a few dollars per channel), have low latency (millisecond), high update rate (1 kHz), high immunity to noise (>72 dB), are not affected by clothing, surface texture or reflectivity, and can operate on length scales from microns to meters. Systems incorporating the sensors include a finger mouse, a room that knows the location of its occupant, and people-sensing furniture. Haptic feedback using passive materials is described. Also discussed are empirical and analytical approaches to transform sensor measurements into position information.