11,208 research outputs found
State of Procedures in High Risk, Highly Regulated Processing Industries
PresentationThe general state of procedures in the highly regulated, high risk industries is poor. Most companies continue to use “Typewriter Technology,” such as MS Word to create procedures and manage them through standard document management systems such as SharePoint, OpenText or Documentum. Companies have focused on minimum compliance, at best, with little regard for incorporating human factors and technology innovations, including digitization, mobilization and personalization. Since the “typewriter technology” limits outputs to paper and requires substantial manual formatting, very little improvements are being made to enhance usage and effectiveness and are rapidly becoming both expensive and archaic to maintain
An Efficient Algorithm For Chinese Postman Walk on Bi-directed de Bruijn Graphs
Sequence assembly from short reads is an important problem in biology. It is
known that solving the sequence assembly problem exactly on a bi-directed de
Bruijn graph or a string graph is intractable. However finding a Shortest
Double stranded DNA string (SDDNA) containing all the k-long words in the reads
seems to be a good heuristic to get close to the original genome. This problem
is equivalent to finding a cyclic Chinese Postman (CP) walk on the underlying
un-weighted bi-directed de Bruijn graph built from the reads. The Chinese
Postman walk Problem (CPP) is solved by reducing it to a general bi-directed
flow on this graph which runs in O(|E|2 log2(|V |)) time. In this paper we show
that the cyclic CPP on bi-directed graphs can be solved without reducing it to
bi-directed flow. We present a ?(p(|V | + |E|) log(|V |) + (dmaxp)3) time
algorithm to solve the cyclic CPP on a weighted bi-directed de Bruijn graph,
where p = max{|{v|din(v) - dout(v) > 0}|, |{v|din(v) - dout(v) < 0}|} and dmax
= max{|din(v) - dout(v)}. Our algorithm performs asymptotically better than the
bidirected flow algorithm when the number of imbalanced nodes p is much less
than the nodes in the bi-directed graph. From our experimental results on
various datasets, we have noticed that the value of p/|V | lies between 0.08%
and 0.13% with 95% probability
Well-posedness and asymptotic behavior of a multidimensional model of morphogen transport
Morphogen transport is a biological process, occurring in the tissue of
living organisms, which is a determining step in cell differentiation. We
present rigorous analysis of a simple model of this process, which is a system
coupling parabolic PDE with ODE. We prove existence and uniqueness of solutions
for both stationary and evolution problems. Moreover we show that the solution
converges exponentially to the equilibrium in topology. We
prove all results for arbitrary dimension of the domain. Our results improve
significantly previously known results for the same model in the case of one
dimensional domain
Noninvasive Measurement of Dissipation in Colloidal Systems
According to Harada and Sasa [Phys. Rev. Lett. 95, 130602 (2005)], heat
production generated in a non-equilibrium steady state can be inferred from
measuring response and correlation functions. In many colloidal systems,
however, it is a nontrivial task to determine response functions, whereas
details about spatial steady state trajectories are easily accessible. Using a
simple conditional averaging procedure, we show how this fact can be exploited
to reliably evaluate average heat production. We test this method using
Brownian dynamics simulations, and apply it to experimental data of an
interacting driven colloidal system
Tagged particle in a sheared suspension: effective temperature determines density distribution in a slowly varying external potential beyond linear response
We consider a sheared colloidal suspension under the influence of an external
potential that varies slowly in space in the plane perpendicular to the flow
and acts on one selected (tagged) particle of the suspension. Using a
Chapman-Enskog type expansion we derive a steady state equation for the tagged
particle density distribution. We show that for potentials varying along one
direction only, the tagged particle distribution is the same as the equilibrium
distribution with the temperature equal to the effective temperature obtained
from the violation of the Einstein relation between the self-diffusion and
tagged particle mobility coefficients. We thus prove the usefulness of this
effective temperature for the description of the tagged particle behavior
beyond the realm of linear response. We illustrate our theoretical predictions
with Brownian dynamics computer simulations.Comment: Accepted for publication in Europhys. Let
Unexpected phase locking of magnetic fluctuations in the multi-k magnet USb
The spin waves in the multi-k antiferromagnet USb soften and become quasielastic well below the antiferromagnetic ordering temperature TN. This occurs without a magnetic or structural transition. It has been suggested that this change is in fact due to dephasing of the different multi-k components: a switch from 3-k to 1-k behavior. In this work, we use inelastic neutron scattering with tridirectional polarization analysis to probe the quasielastic magnetic excitations and reveal that the 3-k structure does not dephase. More surprisingly, the paramagnetic correlations also maintain the same clear phase correlations well above TN (up to at least 1.4TN)
Temperature-dependent Hall scattering factor and drift mobility in remotely doped Si:B/SiGe/Si heterostructures
Hall-and-Strip measurements on modulation-doped SiGe heterostructures and combined Hall and capacitance–voltage measurements on metal-oxide-semiconductor (MOS)-gated enhancement mode structures have been used to deduce Hall scattering factors, rH, in the Si1 – xGex two-dimensional hole gas. At 300 K, rH was found to be equal to 0.4 for x = 0.2 and x = 0.3. Knowing rH, it is possible to calculate the 300 K drift mobilities in the modulation-doped structures which are found to be 400 cm2 V – 1 s – 1 at a carrier density of 3.3 × 1011 cm – 2 for x = 0.2 and 300 cm2 V – 1 s – 1 at 6.3 × 1011 cm – 2 for x = 0.3, factors of between 1.5 and 2.0 greater than a Si pMOS control
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