Survey of partitioning techniques in silicon compilation

In the silicon compilation design process, partitioning is usually the first problem to be investigated because partitioning algorithms form the backbone of many algorithms including: system synthesis, processor synthesis, floorplanning, and placement. In this survey, several partitioning techniques will be examined. In addition, this paper will review the partitioning algorithms used by synthesis systems at different design levels

The Source Size Dependence on the M_hadron Applying Fermi and Bose Statistics and I-Spin Invariance

The emission volume sizes of pions and Kaons, r_{\pi^\pm \pi^\pm} and r_{K^\pm K^\pm}, measured in the hadronic Z^0 decays via the Bose-Einstein Correlations (BEC), and the recent measurements of r_{\Lambda\Lambda} obtained by through the Pauli exclusion principle are used to study the r dependence on the hadron mass. A clear r_{\pi^\pm \pi^\pm} > r_{K^\pm K^\pm} > r_{\Lambda \Lambda} hierarchy is observed which seems to disagree with the basic string (LUND) model expectation. An adequate description of r(m) is obtained via the Heisenberg uncertainty relations and also by Local Parton Hadron Duality approach using a general QCD potential. These lead to a relation of the type r(m) ~ Constant/sqrt{m}. The present lack of knowledge on the f_o(980) decay rate to the K^0\bar{K}^0 channel prohibits the use of the r_{K^0_SK^0_S} in the r(m) analysis. The use of a generalised BEC and I-spin invariance, which predicts an BEC enhancement also in the K^{\pm}K^0 and \pi^{\pm}\pi^0 systems, should in the future help to include the r_{K^0_SK^0_S} in the r(m) analysis.Comment: 7 pages, 4 figures, Based on an invited talk given by G. Alexander at the XXIX Int. Symp. on Multiparticle Dynamics, 9-13 August 1999, Providence RI, USA. (to be published in the proceedings of this conference

Measurements with the Chandra X-Ray Observatory's flight contamination monitor

NASA's Chandra X-ray Observatory includes a Flight Contamination Monitor (FCM), a system of 16 radioactive calibration sources mounted to the inside of the Observatory's forward contamination cover. The purpose of the FCM is to verify the ground-to-orbit transfer of the Chandra flux scale, through comparison of data acquired during the ground calibration with those obtained in orbit, immediately prior to opening the Observatory's sun-shade door. Here we report results of these measurements, which place limits on the change in mirror--detector system response and, hence, on any accumulation of molecular contamination on the mirrors' iridium-coated surfaces.Comment: 7pages,8figures,for SPIE 4012, paper 7

Measurement of the circular polarization in radio emission from extensive air showers confirms emission mechanisms

We report here on a novel analysis of the complete set of four Stokes parameters that uniquely determine the linear and/or circular polarization of the radio signal for an extensive air shower. The observed dependency of the circular polarization on azimuth angle and distance to the shower axis is a clear signature of the interfering contributions from two different radiation mechanisms, a main contribution due to a geomagnetically-induced transverse current and a secondary component due to the build-up of excess charge at the shower front. The data, as measured at LOFAR, agree very well with a calculation from first principles. This opens the possibility to use circular polarization as an investigative tool in the analysis of air shower structure, such as for the determination of atmospheric electric fields.Comment: Accepted for publication in Phys. Rev.

Multichannel telemetry system

A two-channel telemetry system is described in which one channel is used for high-rate data and the other channel for low-rate data communication. In the transmitter a signal, which subsequently phase modulates a carrier, is produced which is a function of at least the high-rate data, the low-rate data and the frequency of the subcarrier of the low-rate channel. In the receiver which includes a phase-locked loop, the high-rate data is detected off the receiver inphase channel output and the low-rate off the quadrature channel output

Hydrodynamic interactions in dense active suspensions: from polar order to dynamical clusters

We study the role of hydrodynamic interactions in the collective behaviour of collections of microscopic active particles suspended in a fluid. We introduce a novel calculational framework that allows us to separate the different contributions to their collective dynamics from hydrodynamic interactions on different length scales. Hence we are able to systematically show that lubrication forces when the particles are very close to each other play as important a role as long-range hydrodynamic interactions in determining their many-body behaviour. We find that motility-induced phase separation is suppressed by near-field interactions, leading to open gel-like clusters rather than dense clusters. Interestingly, we find a globally polar ordered phase appears for neutral swimmers with no force dipole that is enhanced by near field lubrication forces in which the collision process rather than long-range interaction dominates the alignment mechanism.Comment: 7 pages, 4 figure

Extraction of System States from Natural Language Requirements

In recent years, simulations have proven to be an important means to verify the behavior of complex software systems. The different states of a system are monitored in the simulations and are compared against the requirements specification. So far, system states in natural language requirements cannot be automatically linked to signals from the simulation. However, the manual mapping between requirements and simulation is a time-consuming task. Named-entity Recognition is a sub-task from the field of automated information retrieval and is used to classify parts of natural language texts into categories. In this paper, we use a self-trained Named-entity Recognition model with Bidirectional LSTMs and CNNs to extract states from requirements specifications. We present an almost entirely automated approach and an iterative semi-automated approach to train our model. The automated and iterative approach are compared and discussed with respect to the usual manual extraction. We show that the manual extraction of states in 2,000 requirements takes nine hours. Our automated approach achieves an F1-score of 0.51 with 15 minutes of manual work and the iterative approach achieves an F1-score of 0.62 with 100 minutes of work

Stochastic Green's function approach to disordered systems

Based on distributions of local Green's functions we present a stochastic approach to disordered systems. Specifically we address Anderson localisation and cluster effects in binary alloys. Taking Anderson localisation of Holstein polarons as an example we discuss how this stochastic approach can be used for the investigation of interacting disordered systems.Comment: 12 pages, 7 figures, conference proceedings: Progress in Nonequilibrium Green's Functions III, 22-26 August 2005, University of Kiel, German

Differential sensitivity of Atriplex patula and Chenopodium album to sugar beet herbicides : a possible cause for the upsurge of A. patula in sugar beet fields

In the last decade, the prevalence of Atriplex patula as a weed in the Belgian sugar beet area has increased. Possible reasons for its expansion in sugar beet fields, besides a poor implementation of the low-dose phenmedipham/activator/soil-acting herbicide (FAR) system, might be low sensitivity or evolved resistance to one or more herbicides used in sugar beet. Dose-response pot bioassays were conducted in the glasshouse to evaluate the effectiveness of five foliar-applied sugar beet herbicides (metamitron, phenmedipham, desmedipham, ethofumesate and triallate) and three pre-plant-incorporated herbicides (metamitron, lenacil, dimethenamid-P) for controlling five Belgian A.patula populations. Local metamitron-susceptible and metamitron-resistant populations of Chenopodium album were used as reference populations. Effective dosages and resistance indices were calculated. DNA sequence analysis of the photosystem II psbA gene was performed on putative resistant A.patula populations. Overall, A.patula exhibited large intraspecific variation in herbicide sensitivity. In general, A.patula populations were less susceptible to phenmedipham, desmedipham, ethofumesate and triallate relative to C.album populations. Two A.patula populations bear the leucine-218 to valine mutation on the chloroplast psbA gene conferring low level to high level cross-resistance to the photosystem II inhibitors phenmedipham, desmedipham, metamitron and lenacil. In order to avoid insufficient A.patula control and further spread, seedlings should preferentially be treated with FAR mixtures containing higher-than-standard doses of metamitron and phenmedipham/desmedipham and no later than the cotyledon stage