24,531 research outputs found
A Multifunctional Processing Board for the Fast Track Trigger of the H1 Experiment
The electron-proton collider HERA is being upgraded to provide higher
luminosity from the end of the year 2001. In order to enhance the selectivity
on exclusive processes a Fast Track Trigger (FTT) with high momentum resolution
is being built for the H1 Collaboration. The FTT will perform a 3-dimensional
reconstruction of curved tracks in a magnetic field of 1.1 Tesla down to 100
MeV in transverse momentum. It is able to reconstruct up to 48 tracks within 23
mus in a high track multiplicity environment. The FTT consists of two hardware
levels L1, L2 and a third software level. Analog signals of 450 wires are
digitized at the first level stage followed by a quick lookup of valid track
segment patterns.
For the main processing tasks at the second level such as linking, fitting
and deciding, a multifunctional processing board has been developed by the ETH
Zurich in collaboration with Supercomputing Systems (Zurich). It integrates a
high-density FPGA (Altera APEX 20K600E) and four floating point DSPs (Texas
Instruments TMS320C6701). This presentation will mainly concentrate on second
trigger level hardware aspects and on the implementation of the algorithms used
for linking and fitting. Emphasis is especially put on the integrated CAM
(content addressable memory) functionality of the FPGA, which is ideally suited
for implementing fast search tasks like track segment linking.Comment: 6 pages, 4 figures, submitted to TN
Daytime REM sleep affects emotional experience but not decision choices in moral dilemmas
Moral decision-making depends on the interaction between automatic emotional responses and rational cognitive control. A natural emotional regulator state seems to be sleep, in particular rapid eye movement (REM) sleep. We tested the impact of daytime sleep, either with or without REM, on moral decision. Sixty participants were presented with 12 sacrificial (6 Footbridge-and 6 Trolley-type) and 8 everyday-type moral dilemmas at 9 AM and at 5 PM. In sacrificial dilemmas, participants had to decide whether or not to kill one person to save more people (utilitarian choice), and to judge how morally acceptable the proposed choice was. In everyday-type dilemmas, participants had to decide whether to endorse moral violations involving dishonest behavior. At 12 PM, 40 participants took a 120-min nap (17 with REM and 23 with NREM only) while 20 participants remained awake. Mixed-model analysis revealed that participants judged the utilitarian choice as less morally acceptable in the afternoon, irrespective of sleep. We also observed a negative association between theta activity during REM and increased self-rated unpleasantness during moral decisions. Nevertheless, moral decision did not change across the day and between groups. These results suggest that although both time and REM sleep may affect the evaluation of a moral situation, these factors did not ultimately impact the individual moral choices
Asymptotic Signal Detection Rates with 1-bit Array Measurements
This work considers detecting the presence of a band-limited random radio
source using an antenna array featuring a low-complexity digitization process
with single-bit output resolution. In contrast to high-resolution
analog-to-digital conversion, such a direct transformation of the analog radio
measurements to a binary representation can be implemented hardware and
energy-efficient. However, the probabilistic model of the binary receive data
becomes challenging. Therefore, we first consider the Neyman-Pearson test
within generic exponential families and derive the associated analytic
detection rate expressions. Then we use a specific replacement model for the
binary likelihood and study the achievable detection performance with 1- bit
radio array measurements. As an application, we explore the capability of a
low-complexity GPS spectrum monitoring system with different numbers of
antennas and different observation intervals. Results show that with a moderate
amount of binary sensors it is possible to reliably perform the monitoring
task
IR-UWB Detection and Fusion Strategies using Multiple Detector Types
Optimal detection of ultra wideband (UWB) pulses in a UWB transceiver
employing multiple detector types is proposed and analyzed in this paper. We
propose several fusion techniques for fusing decisions made by individual
IR-UWB detectors. We assess the performance of these fusion techniques for
commonly used detector types like matched filter, energy detector and amplitude
detector. In order to perform this, we derive the detection performance
equation for each of the detectors in terms of false alarm rate, shape of the
pulse and number of UWB pulses used in the detection and apply these in the
fusion algorithms. We show that the performance can be improved approximately
by 4 dB in terms of signal to noise ratio (SNR) for perfect detectability of a
UWB signal in a practical scenario by fusing the decisions from individual
detectors.Comment: Accepted for publishing in IEEE WCNC 201
Logic Programming and Logarithmic Space
We present an algebraic view on logic programming, related to proof theory
and more specifically linear logic and geometry of interaction. Within this
construction, a characterization of logspace (deterministic and
non-deterministic) computation is given via a synctactic restriction, using an
encoding of words that derives from proof theory.
We show that the acceptance of a word by an observation (the counterpart of a
program in the encoding) can be decided within logarithmic space, by reducing
this problem to the acyclicity of a graph. We show moreover that observations
are as expressive as two-ways multi-heads finite automata, a kind of pointer
machines that is a standard model of logarithmic space computation
Introducing Quantified Cuts in Logic with Equality
Cut-introduction is a technique for structuring and compressing formal
proofs. In this paper we generalize our cut-introduction method for the
introduction of quantified lemmas of the form (for
quantifier-free ) to a method generating lemmas of the form . Moreover, we extend the original method to predicate
logic with equality. The new method was implemented and applied to the TSTP
proof database. It is shown that the extension of the method to handle equality
and quantifier-blocks leads to a substantial improvement of the old algorithm
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