7,121 research outputs found
The relationship between capacity utilization and inflation
There's a common belief among economists that when thereâs slack in the economy â that is, when labor and capital are not fully employed â the economy can expand without an increase in inflation. One measure of the intensity with which labor and capital are used in producing output is the capacity utilization rate. According to some economists, when capacity utilization is low, firms can increase employment and their use of capital without incurring large increases in the costs of production. So firms will not be forced to raise prices in order to make profits on additional output. But this theory is not universally accepted. In âThe Relationship Between Capacity Utilization and Inflation,â Mike Dotsey and Tom Stark investigate some of the problems with what, at first glance, seems a compelling story.Inflation (Finance) ; Industrial capacity
Asymptotic enumeration of 2-covers and line graphs
In this paper we find asymptotic enumerations for the number of line graphs
on -labelled vertices and for different types of related combinatorial
objects called 2-covers.
We find that the number of 2-covers, , and proper 2-covers, , on
both have asymptotic growth where is the th Bell number, while the number of
restricted 2-covers, , restricted, proper 2-covers on , , and
line graphs , all have growth
In our proofs we use probabilistic arguments for the unrestricted types of
2-covers and and generating function methods for the restricted types of
2-covers and line graphs
Asymptotics for incidence matrix classes
We define {\em incidence matrices} to be zero-one matrices with no zero rows
or columns. A classification of incidence matrices is considered for which
conditions of symmetry by transposition, having no repeated rows/columns, or
identification by permutation of rows/columns are imposed. We find asymptotics
and relationships for the number of matrices with ones in these classes as
.Comment: updated and slightly expanded versio
Trading locality for time: certifiable randomness from low-depth circuits
The generation of certifiable randomness is the most fundamental
information-theoretic task that meaningfully separates quantum devices from
their classical counterparts. We propose a protocol for exponential certified
randomness expansion using a single quantum device. The protocol calls for the
device to implement a simple quantum circuit of constant depth on a 2D lattice
of qubits. The output of the circuit can be verified classically in linear
time, and is guaranteed to contain a polynomial number of certified random bits
assuming that the device used to generate the output operated using a
(classical or quantum) circuit of sub-logarithmic depth. This assumption
contrasts with the locality assumption used for randomness certification based
on Bell inequality violation or computational assumptions. To demonstrate
randomness generation it is sufficient for a device to sample from the ideal
output distribution within constant statistical distance.
Our procedure is inspired by recent work of Bravyi et al. (Science 2018), who
introduced a relational problem that can be solved by a constant-depth quantum
circuit, but provably cannot be solved by any classical circuit of
sub-logarithmic depth. We develop the discovery of Bravyi et al. into a
framework for robust randomness expansion. Our proposal does not rest on any
complexity-theoretic conjectures, but relies on the physical assumption that
the adversarial device being tested implements a circuit of sub-logarithmic
depth. Success on our task can be easily verified in classical linear time.
Finally, our task is more noise-tolerant than most other existing proposals
that can only tolerate multiplicative error, or require additional conjectures
from complexity theory; in contrast, we are able to allow a small constant
additive error in total variation distance between the sampled and ideal
distributions.Comment: 36 pages, 2 figure
Analysis of the Accase Mutation Profile of Italian Ryegrass (Lolium Perenne SSP. Multiflorum) Accessions Resistant to Accase Inhibitors
Lolium perenne ssp. multiflorum (Italian ryegrass) resistant to ACCase inhibiting herbicides has been reported in many wheat producing counties across Arkansas. Resistance is believed to be the result of point mutations creating amino acid substitutions in the CT domain of the plastidic ACCase gene. This study explores the occurrence of mutations in the ACCase gene of ryegrass populations. Plant material was collected and DNA was extracted from 10 Arkansas ryegrass populations. Six of the populations were known to be resistant to the ACCase inhibitor diclofop-methyl, while the remaining four populations were known to be susceptible to diclofop-methyl. Two highly conserved regions of the plastidic ACCase gene known to contain mutations that confer resistance to ACCase inhibiting herbicides were then amplified and sequenced. Analysis of the sequences revealed that only 41% of the resistant populations expressed a mutation known to confer resistance. Several resistant populations of ryegrass did not contain any of the known mutations in their plastidic ACCase gene. This result means that either a mutation in a different region of the CT domain affects the affinity to ACCase inhibiting herbicides or the plants harbor a different mechanism of resistance. Further, in some resistant populations, not all plants within that population possessed a mutation known to cause resistance to ACCase inhibitors. This suggests that within a population, multiple mechanisms of resistance may exist. Further research is needed to determine the mechanism of resistance in diclofop-resistant plants that do not harbor mutations in the tested ACCase herbicide-binding domains
An Extensible Timing Infrastructure for Adaptive Large-scale Applications
Real-time access to accurate and reliable timing information is necessary to
profile scientific applications, and crucial as simulations become increasingly
complex, adaptive, and large-scale. The Cactus Framework provides flexible and
extensible capabilities for timing information through a well designed
infrastructure and timing API. Applications built with Cactus automatically
gain access to built-in timers, such as gettimeofday and getrusage,
system-specific hardware clocks, and high-level interfaces such as PAPI. We
describe the Cactus timer interface, its motivation, and its implementation. We
then demonstrate how this timing information can be used by an example
scientific application to profile itself, and to dynamically adapt itself to a
changing environment at run time
Advanced semantics for accelerated graph processing
Large-scale graph applications are of great national, commercial, and societal importance, with direct use in ïŹelds such as counter-intelligence, proteomics, and data mining. Unfortunately, graph-based problems exhibit certain basic characteristics that make them a poor match for conventional computing systems in terms of structure, scale, and semantics. Graph processing kernels emphasize sparse data structures and computations with irregular memory access patterns that destroy the temporal and spatial locality upon which modern processors rely for performance. Furthermore, applications in this area utilize large data sets, and have been shown to be more data intensive than typical ïŹoating-point applications, two properties that lead to inefficient utilization of the hierarchical memory system. Current approaches to processing large graph data sets leverage traditional HPC systems and programming models, for shared memory and message-passing computation, and are thus limited in efficiency, scalability, and programmability. The research presented in this thesis investigates the potential of a new model of execution that is hypothesized as a promising alternative for graph-based applications to conventional practices. A new approach to graph processing is developed and presented in this thesis. The application of the experimental ParalleX execution model to graph processing balances continuation-migration style ïŹne-grain concurrency with constraint-based synchronization through embedded futures. A collection of parallel graph application kernels provide experiment control drivers for analysis and evaluation of this innovative strategy. Finally, an experimental software library for scalable graph processing, the ParalleX Graph Library, is deïŹned using the HPX runtime system, providing an implementation of the key concepts and a framework for development of ParalleX-based graph applications
Culture, Utility or Social Systems?:Explaining the Cross-National Ties of Emigrants from Borsa, Romania
Emigrants from BorĆa, Romania, display two quite distinct patterns of ties with their community of origin: migration to Italy is discernibly transnational, with a strong reliance on migrant networks; while migration to the UK is more individualistic, with emigrants shunning interaction with compatriots and retaining only weak ties to BorĆa. We argue that prevalent theories of cross-national ties fail adequately to explain this divergence. Instead, we draw on systems theory to explain the discrepancy in terms of divergent conditions for societal inclusion. In Italy, incorporation into parallel, unofficial structures of work, welfare and accommodation encouraged a reliance on cultural criteria for maintaining social ties. In the UK, migrants were obliged to integrate into state-sponsored systems, encouraging the relinquishing of ethnic ties in favour of more strategic networking to facilitate societal inclusion
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