2,084 research outputs found
A high resolution solar atlas for fluorescence calculations
The characteristics required of a solar atlas to be used for studying the fluorescence process in comets are examined. Several sources of low resolution data were combined to provide an absolutely calibrated spectrum from 2250 A to 7000A. Three different sources of high resolution data were also used to cover this same spectral range. The low resolution data were then used to put each high resolution spectrum on an absolute scale. The three high resolution spectra were then combined in their overlap regions to produce a single, absolutely calibrated high resolution spectrum over the entire spectral range
From Representation by Population to the Pursuit of Elegance
Will the Canadian people be content with the present format of our recently won constitution? I do not think so. The obstacles to any further changes are indeed formidable, but they were equally formidable in the cases of the changes that have been achieved. In those cases, a popular will was at work which was spurred by the energy of a near-coalition of aggrieved groups, but which gently forced these energies into the formation of a more moderate working consensus. It is true that the consensus is a crippled one, especially concerning Quebec, and several problems will have to be settled before we can truly say that we have a satisfactory and nation-wide constitutional understandin
Pre-hospital pain management patterns and triage nurse documentation
Introduction: Little is known about the public's preferences for pain management prior to attending an Emergency Department (ED). Therefore, the aim of the study was to explore (i) triage documentation of pre-hospital analgesic patterns for patients presenting in pain; (ii) patient documented explanations for not self administering an analgesic in the pre-hospital setting; (iii) triage nurse documentation of pain descriptors and or pain scores; and (iv) the disposition of ED patients presenting in pain. Method: A 2-week retrospective exploratory review was conducted. Results: There were 2142 ED presentations during the 2-week study and 52% of patients had documented evidence of arriving with a painful condition. Of the 1113 patients 60% were documented to be in pain on arrival. Of the group documented to have arrived in pain only 28% self-administered or received an analgesic in the pre-hospital/community setting. Patients provided a variety of reasons for not self-administering a pre-hospital analgesic. Conclusion: Unnecessary suffering may be avoided if the public had a better understanding of pain and the benefits of pain management. Further research is required to better understand the beliefs and attitudes towards pain and pain management by clinicians and the public. © 2011 Elsevier Ltd
Fixed-Parameter Tractability of Token Jumping on Planar Graphs
Suppose that we are given two independent sets and of a graph
such that , and imagine that a token is placed on each vertex in
. The token jumping problem is to determine whether there exists a
sequence of independent sets which transforms into so that each
independent set in the sequence results from the previous one by moving exactly
one token to another vertex. This problem is known to be PSPACE-complete even
for planar graphs of maximum degree three, and W[1]-hard for general graphs
when parameterized by the number of tokens. In this paper, we present a
fixed-parameter algorithm for the token jumping problem on planar graphs, where
the parameter is only the number of tokens. Furthermore, the algorithm can be
modified so that it finds a shortest sequence for a yes-instance. The same
scheme of the algorithms can be applied to a wider class of graphs,
-free graphs for any fixed integer , and it yields
fixed-parameter algorithms
One-loop counterterms for the dimensional regularization of arbitrary Lagrangians
We present master formulas for the divergent part of the one-loop effective
action for an arbitrary (both minimal and nonminimal) operators of any order in
the 4-dimensional curved space. They can be considered as computer algorithms,
because the one-loop calculations are then reduced to the simplest algebraic
operations. Some test applications are considered by REDUCE analytical
calculation system.Comment: 39 pages, Latex, 3 PS figures, replaced with published versio
Reflectometer distance measurement between parallel conductive plates
This report presents an analytic and experimental investigation of the measurement problem in which a reflectometer is used to determine the distance to a target that is a highly conductive surface parallel to the reflectometer antenna ground plane. These parallel surfaces constitute a waveguide (WG) which can contribute parasitic perturbations that seriously degrade the accuracy of the measurements. Two distinct parallel-plate-waveguide (PPWG) phenomena are described, and their effects on both frequency and time-domain reflectometers are considered. The time-domain processing approach was found to be superior to a representative frequency-domain phase-measurement approach because of less susceptibility to perturbations produced by edge reflections and immunity to phase capture. Experimental results are presented which show that a simple radiating system modification can suppress parallel-plate (PP) propagation. The addition of a thin layer of lossy mu-metal 'magnetic absorber' to the antenna ground plane allowed a measurement accuracy of 0.025 cm (0.01 in.) when a vector network analyzer (VNA) is used as a time-domain reflectometer
Poems
Poems include: 5th Ave.--New York City, by Edwina Hearn, Trenchcoated and Delivered, by Erika T. Lersch, and Blue, by Michael Anthony Moor
The complexity of dominating set reconfiguration
Suppose that we are given two dominating sets and of a graph
whose cardinalities are at most a given threshold . Then, we are asked
whether there exists a sequence of dominating sets of between and
such that each dominating set in the sequence is of cardinality at most
and can be obtained from the previous one by either adding or deleting
exactly one vertex. This problem is known to be PSPACE-complete in general. In
this paper, we study the complexity of this decision problem from the viewpoint
of graph classes. We first prove that the problem remains PSPACE-complete even
for planar graphs, bounded bandwidth graphs, split graphs, and bipartite
graphs. We then give a general scheme to construct linear-time algorithms and
show that the problem can be solved in linear time for cographs, trees, and
interval graphs. Furthermore, for these tractable cases, we can obtain a
desired sequence such that the number of additions and deletions is bounded by
, where is the number of vertices in the input graph
Reconfiguration of Dominating Sets
We explore a reconfiguration version of the dominating set problem, where a
dominating set in a graph is a set of vertices such that each vertex is
either in or has a neighbour in . In a reconfiguration problem, the goal
is to determine whether there exists a sequence of feasible solutions
connecting given feasible solutions and such that each pair of
consecutive solutions is adjacent according to a specified adjacency relation.
Two dominating sets are adjacent if one can be formed from the other by the
addition or deletion of a single vertex.
For various values of , we consider properties of , the graph
consisting of a vertex for each dominating set of size at most and edges
specified by the adjacency relation. Addressing an open question posed by Haas
and Seyffarth, we demonstrate that is not necessarily
connected, for the maximum cardinality of a minimal dominating set
in . The result holds even when graphs are constrained to be planar, of
bounded tree-width, or -partite for . Moreover, we construct an
infinite family of graphs such that has exponential
diameter, for the minimum size of a dominating set. On the positive
side, we show that is connected and of linear diameter for any
graph on vertices having at least independent edges.Comment: 12 pages, 4 figure
Token Jumping in minor-closed classes
Given two -independent sets and of a graph , one can ask if it
is possible to transform the one into the other in such a way that, at any
step, we replace one vertex of the current independent set by another while
keeping the property of being independent. Deciding this problem, known as the
Token Jumping (TJ) reconfiguration problem, is PSPACE-complete even on planar
graphs. Ito et al. proved in 2014 that the problem is FPT parameterized by
if the input graph is -free.
We prove that the result of Ito et al. can be extended to any
-free graphs. In other words, if is a -free
graph, then it is possible to decide in FPT-time if can be transformed into
. As a by product, the TJ-reconfiguration problem is FPT in many well-known
classes of graphs such as any minor-free class
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