A multiprocessor DSP System for a high throughput control application

This paper describes the hardware concept and realization of an experimental multiprocessor system with Digital Signal Processors TMS320C6701. For convenience and efficiency piggyback modules have been used. The structure is organized in master-slave manner. The slaves are accessed from the master through their host port interfaces. Special address decoding provides broadcasted write from the master to all slaves besides individual read and write access. Some experimental results are provided

Statischer Kraftausgleich mit Bandgetrieben und Federn

Ausgleichsmechanismen mit Federn werden sehr oft zur Reduzierung von Bedienkräften genutzt. Bekannte Beispiele sind im Umfeld der Möbelindustrie bei der Betätigung von Schranktüren, Sesseln oder Tischen zu finden. Ebenso kann ein Kraftausgleich durch Federn auch zur Kompensation statischer Kräften aus parasitären Steifigkeiten auf einfache Weise dienen. Um eine passende und i. d. R. nichtlineare Ausgleichskraft zu generieren, ist es erforderlich, die im Allgemeinen linear mit dem Federweg ansteigende Federkraft in einen zur Kompensation erforderlichen Kraft- bzw. Drehmomentverlauf umzuwandeln. Dies ist z. B. durch Getriebe mit nichtlinearer Charakteristik möglich. Jedoch sind die Anpassungsmöglichkeiten bei Verwendung einfacher Koppelgetriebe begrenzt. Ausgehend von der Darstellung der klassischen Synthese für ein Feder-Bandgetriebe nach HAIN wird in diesem Beitrag ein einfaches Bandgetriebe der Struktur DB~SD zum vollständigen Kraftausgleich beschrieben. Im Gegensatz zum zeichnerisch geprägten Lösungsansatz für Bandgetriebe mit Federn nach HAIN, das von Anbeginn die Getriebestruktur in den Syntheseprozess einbezieht, wird bei der nun vorgestellten Synthese zunächst eine Übertragungsfunktion in Abhängigkeit der Federparameter durch einen speziellen Optimierungsansatz bestimmt. Im Anschluss erfolgt für eine ausgewählte Bandgetriebestruktur die Maßsynthese der gesuchten und stetig konvex gekrümmten Bandkurvenscheibe. Die zur Generierung der Bandkurvenkontur erforderliche Evolvente wird unter Einbeziehung der Momentanpollagen neu hergeleitet. Zur Anwendung dieser Methodik im Umfeld der antriebstechnischen Systemsimulation wurden die neu geschaffenen Funktionen in die Software SimulationX integriert. Abschließend wird für eine Oberschranktür die Funktionsweise des Gewichtskraftausgleichs beispielhaft berechnet und experimentell verifiziert.Compensation mechanisms with springs are often used to reduce operating forces. Well-known examples are in the vicinity of the furniture industry in the operation of cabinet doors, tables or chairs. Similarly, a force balance by springs also serves to compensate for static forces from parasitic stiffness in a simple way. To generate an appropriate and usually non-linear compensating force, it is necessary to convert the generally linear with the travel rising spring force into a force or torque curve required for compensation. This is possible, for example, by gear with non-linear characteristic. However, the customization options are limited when using simple linkage. Starting from the presentation of the classical synthesis of a spring-band transmission of HAIN a simple band structure of transmission DB~SD to the full force balance is described in this paper. In marked contrast to the approach to the drawing band transmission with springs that includes transmission structure from the outset in the synthesis process, wherein the synthesis is first of all now presented a transfer function. It’s determined in dependence on the parameters of the spring by a specific optimization approach. After the determination of the transfer function is a selection of the transmission band structure. Here, the synthesis of this and continuously convexly curved band cam is performed. The required to generate the band contour curve involute is derived taking into account the new instantaneous location. The newly created functions were integrated into the system simulation for the application of this methodology in the field of drive engineering system simulation. Finally, the function of the weight balance is exemplified calculated and experimentally verified by upper cabinet door

The Sommerfeld enhancement for scalar particles and application to sfermion co-annihilation regions

We study the impact of the Sommerfeld enhancement on the thermal relic density of the lightest neutralino in the case of large co-annihilation effects with a scalar particle. The proper way of including the Sommerfeld effect in this case is discussed, and the appropriate formulas for a general scenario with a set of particles with arbitrary masses and (off-)diagonal interactions are provided. We implement these results to compute the relic density in the neutralino sfermion co-annihilation regions in the mSUGRA framework. We find non-negligible effects in whole sfermion co-annihilation regimes. For stau co-annihilations the correction to the relic density is of the order of several per cent, while for stop co-annihilations is much larger, reaching a factor of 5 in some regions of the parameter space. A numerical package for computing the neutralino relic density including the Sommerfeld effect in a general MSSM setup is made public available.Comment: 6 pages, 7 figures; reference added, minor corrections, results unchanged; version to be published in Physics Letters

Surrogates for myocardial power and power efficiency in patients with aortic valve disease

We aimed to assess surrogate markers for left ventricular (LV) myocardial power and efficiency in patients with isolated aortic stenosis (AS) and combined stenosis/regurgitation (AS/AR). In AS (n = 59), AS/AR (n = 21) and controls (n = 14), surrogates for LV myocardial power and circulatory/external myocardial efficiency were obtained from cardiac MRI. Median surrogate LV myocardial power was increased in AS, 7.7 W/m2 (interquartile range 6.0-10.2; p = 0.010) and AS/AR, 10.8 W/m2 (8.9-13.4; p < 0.001) when compared to controls, 5.4 W/m2 (4.2-6.5), and was lower in AS than AS/AR (p < 0.001). Surrogate circulatory efficiency was decreased in AS, 8.6% (6.8-11.1; p < 0.001) and AS/AR, 5.4% (4.1-6.2; p < 0.001) when compared to controls, 11.8% (9.8-16.9). Surrogate external myocardial efficiency was higher in AS, 15.2% (11.9-18.6) than in AS/AR, 12.2% (10.1-14.2; p = 0.031) and was significantly lower compared to controls, 12.2% (10.7-18.1) in patients with reduced ejection fraction (EF), 9.8% (8.1-11.7; p = 0.025). In 16% of all cases, left ventricular mass/volume indices and EF were within normal ranges, wheras surrogate LV myocardial power was elevated and patients were symptomatic. Although influenced by pressure/volume load, the myocardium is additionally affected by remodelling processes. Surrogates for circulatory efficiency and LV myocardial power gradually reflect alterations in patients with AS and AS/AR, even when surrogate external myocardial efficiency, EF, mass and volume indices still remain compensated

J/psi Production via Fragmentation at the Tevatron

The production of \jpsi at large transverse momenta (\pt > M_\jpsi) in $p\bar p$ collisions is considered by including the mechanism of fragmentation. Both contributions of fragmentation to \jpsi and of fragmentation to $\chi$ states followed by radiative decay to \jpsi are taken into account. The latter is found to be dominant and larger than direct production. The overall theoretical estimate is shown to be nearly consistent with the experimental observation.Comment: LaTeX, 7 pages. Preprint FNT/T-94/13, LNF-94/024(P). Data taken from a reference were incorrect and have been changed. Complete postscript file available via anonymous ftp at cobra1.pv.infn.it, as pub/jpsi.ps(.Z)(.gz

A wide scalar neutrino resonance and b\bar{b} production at LEP

In supersymmetric models with R-parity violation, scalar neutrinos may be produced as s-channel resonances in e^+e^- colliders. We note that within current constraints, the scalar neutrino may have a width of several GeV into b\bar{b} and be produced with large cross section, leading to a novel supersymmetry discovery signal at LEP II. In addition, if the scalar neutrino mass approximately equals m_Z, such a resonance necessarily increases R_b and reduces A_{FB}(b), significantly improving the fit to electroweak data. Bounds from B meson and top quark decays are leading constraints, and we stress the importance of future measurements.Comment: 8 pages. LaTex + RevTex. Revised to include a discussion of ISR effects. Version to appear in Phys. Rev. Let

Effective Field Theory of Anomalous Gauge-Boson Couplings at High-Energy pp Colliders

We compute the effects of anomalous gauge-boson couplings at high-energy hadron colliders using next-to-leading order $SU(2) \times SU(2)$ chiral perturbation theory. By comparing the yields from the universal $p^2$ terms with those arising from new physics at order $p^4$, we estimate the sensitivity of the SSC and LHC to the indirect effects of electroweak symmetry breaking.Comment: FERMILAB-PUB-92/75-T; Figures not include