1,369 research outputs found
A cambridge ring node controller
This report gives a discussion of the design of a peripheral controller chip to Interface a Cambridge Ring Node to a MC68000 host machine using VLSI technology. The design of such a chip involves following a design strategy. The strategy used Identities what the Interface should be capable of doing. developing a functional description of the interface. mapping the interface onto silicon and finally verifying the design. The characteristics of the interface and the design strategy. along with the software used In the design. will be discussed
Maximum likelihood analysis of systematic errors in interferometric observations of the cosmic microwave background
We investigate the impact of instrumental systematic errors in
interferometric measurements of the cosmic microwave background (CMB)
temperature and polarization power spectra. We simulate interferometric CMB
observations to generate mock visibilities and estimate power spectra using the
statistically optimal maximum likelihood technique. We define a quadratic error
measure to determine allowable levels of systematic error that do not induce
power spectrum errors beyond a given tolerance. As an example, in this study we
focus on differential pointing errors. The effects of other systematics can be
simulated by this pipeline in a straightforward manner. We find that, in order
to accurately recover the underlying B-modes for r=0.01 at 28<l<384,
Gaussian-distributed pointing errors must be controlled to 0.7^\circ rms for an
interferometer with an antenna configuration similar to QUBIC, in agreement
with analytical estimates. Only the statistical uncertainty for 28<l<88 would
be changed at ~10% level. With the same instrumental configuration, we find the
pointing errors would slightly bias the 2-\sigma upper limit of the
tensor-to-scalar ratio r by ~10%. We also show that the impact of pointing
errors on the TB and EB measurements is negligibly small.Comment: 10 pages, 4 figures, accepted for publication in ApJS. Includes
improvements in clarity of presentation and Fig.4 added, in response to
refere
Measurement of cruelty in children: The Cruelty to Animals Inventory
Cruelty to animals may be a particularly pernicious aspect of problematic child development. Progress in understanding the development of the problem is limited due to the complex nature of cruelty as a construct, and limitations with current assessment measures. The Children and Animals Inventory (CAI) was developed as a brief self- and parent-report measure of F. R. Ascione''s (1993) 9 parameters of cruelty. The CAI emerged as a reliable, stable, and readily utilized measure of cruelty using parent and child reports. Children (especially the older children) reported higher rates of cruelty than their parents and boys reported more cruelty than girls. Self- and parent-reports showed good convergence with independent observations of cruelty versus nurturance during free interactions with domestic animals. The results indicate that cruelty to animals can be reliably measured using brief child and parent report measures
Throughput-Optimal Routing in Unreliable Networks
We demonstrate the feasibility of throughput-efficient routing in a highly unreliable network. Modeling a network as a graph with vertices representing nodes and edges representing the links between them, we consider two forms of unreliability: unpredictable edge-failures, and deliberate deviation from protocol specifications by corrupt nodes. The first form of unpredictability represents networks with dynamic topology, whose links may be constantly going up and down; while the second form represents malicious insiders attempting to disrupt communication by deliberately disobeying routing rules, by e.g. introducing junk messages or deleting or altering messages. We present a robust routing protocol for end-to-end communication that is simultaneously resilient to both forms of unreliability, achieving provably optimal throughput performance. Our proof proceeds in three steps: 1) We use competitive-analysis to find a lower-bound on the optimal throughput-rate of a routing protocol in networks susceptible to only edge-failures (i.e. networks with no malicious nodes); 2) We prove a matching upper bound by presenting a routing protocol that achieves this throughput rate (again in networks with no malicious nodes); and 3) We modify the protocol to provide additional protection against malicious nodes, and prove the modified protocol performs (asymptotically) as well as the original
The impact of Covid-19 on productivity
We analyse the impact of Covid-19 on productivity using data from an innovative monthly firm survey panel that asks for quantitative impacts of Covid on inputs and outputs. We find total factor productivity (TFP) fell by up to 5% during 2020-21. The overall impact combined large reductions in 'within-firm' productivity, with an offsetting positive 'between-firm' effects as less productive sectors, and less productive firms within them, contracted. Despite these large pandemic effects, firms' post-Covid forecasts imply surprisingly little lasting impact on aggregate TFP. We also see significant heterogeneity over firms and sectors, with the greatest impacts in those requiring extensive in-person activity. We also ask about unmeasured inflation in the form of deteriorating product quality, finding an additional 1.4% negative impact on TFP
Firming up price inflation
We use data from a large panel survey of UK firms to analyze the economic drivers of price setting since the start of the Covid pandemic. Inflation responded asymmetrically to movements in demand. This helps to explain why inflation did not fall much during the negative initial pandemic demand shock. Energy prices and shortages of labor and materials account for most of the rise during the rebound. Inflation rates across firms have become more dispersed and skewed since the start of the pandemic. We find that average price inflation is positively correlated with the dispersion and skewness of the distribution. Finally, we also introduce a novel measure of subjective inflation uncertainty within firms and show how this has increased during the pandemic, continuing to rise in 2022 even as sales uncertainty dropped back
CNF-FSS and its Applications
Function Secret Sharing (FSS), introduced by Boyle, Gilboa and Ishai [BGI15],
extends the classical notion of secret-sharing a *value* to secret sharing a
*function*. Namely, for a secret function f (from a class ), FSS provides a
sharing of f whereby *succinct shares (``keys\u27\u27) are distributed to a set of
parties, so that later the parties can non-interactively compute an additive
sharing of f(x), for any input x in the domain of f. Previous work on FSS
concentrated mostly on the two-party case, where highly efficient schemes are
obtained for some simple, yet extremely useful, classes (in particular,
FSS for the class of point functions, a task referred to as DPF -- Distributed
Point Functions [GI14,BGI15].
In this paper, we concentrate on the multi-party case, with p >= 3 parties and
t-security (1 <= t < p). First, we introduce the notion of CNF-DPF (or, more
generally, CNF-FSS), where the scheme uses the CNF version of secret sharing
(rather than additive sharing) to share each value . We then demonstrate
the utility of CNF-DPF by providing several applications. Our main result
shows how CNF-DPF can be used to achieve substantial asymptotic improvement in
communication complexity when using it as a building block for constructing
*standard* (t,p)-DPF protocols that tolerate t > 1 (semi-honest) corruptions.
For example, we build a 2-out-of-5 secure (standard) DPF scheme of
communication complexity O(N^{1/4}), where N is the domain size of f (compared
with the current best-known of O(N^{1/2}) for (2,5)-DPF). More generally,
with p > d*t parties, we give a (t,p)-DPF whose complexity grows as
O(N^{1/2d}) (rather than O(\sqrt{N}) that follows from the (p-1,p)-DPF scheme
of [BGI15]).
We also present a 1-out-of-3 secure CNF-DPF scheme, in which each party holds
two of the three keys, with poly-logarithmic communication complexity. These
results have immediate implications to scenarios where (multi-server) DPF was
shown to be applicable. For example, we show how to use such a scheme to
obtain asymptotic improvement (O(\log^2N) versus O(\sqrt{N})) in communication
complexity over the 3-party protocol of [BKKO20]
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