A fixed-point action for the lattice Schwinger model
Lang, C B
1997-01-01
We determine non-perturbatively a fixed-point (FP) action for fermions in the two-dimensional U(1) gauge (Schwinger) model. Our parameterization for the fermionic action has terms within a $7\\times 7$ square on the lattice, using compact link variables. With the Wilson fermion action as starting point we determine the FP-action by iterating a block spin transformation (BST) with a blocking factor of 2 in the background of non-compact gauge field configurations sampled according to the (perfect) Gaussian measure. We simulate the model at various values of $\\beta$ and find excellent improvement for the studied observables.
Fixed point action for the massless lattice Schwinger model
Lang, C B
1998-01-01
We determine non-perturbatively the fixed-point action for fermions in the two-dimensional U(1) gauge (Schwinger) model. This is done by iterating a block spin transformation in the background of non-compact gauge field configurations sampled according to the (perfect) Gaussian measure. The resulting action has 123 independent couplings, is bilinear in the Grassmann fields, gauge-invariant by considered the compact gauge transporters and localized within a $7\\times 7$ lattice centered around one of the fermions. We then simulate the model at various values of $\\beta$ and compare with results obtained with the Wilson fermion action. We find excellent improvement for the studied observables (propagators and masses).
NASA Astrophysics Data System (ADS)
Mauroy, A.; Mezi?, I.; Moehlis, J.
2013-10-01
For asymptotically periodic systems, a powerful (phase) reduction of the dynamics is obtained by computing the so-called isochrons, i.e. the sets of points that converge toward the same trajectory on the limit cycle. Motivated by the analysis of excitable systems, a similar reduction has been attempted for non-periodic systems admitting a stable fixed point. In this case, the isochrons can still be defined but they do not capture the asymptotic behavior of the trajectories. Instead, the sets of interest-that we call “isostables”-are defined in the literature as the sets of points that converge toward the same trajectory on a stable slow manifold of the fixed point. However, it turns out that this definition of the isostables holds only for systems with slow-fast dynamics. Also, efficient methods for computing the isostables are missing. The present paper provides a general framework for the definition and the computation of the isostables of stable fixed points, which is based on the spectral properties of the so-called Koopman operator. More precisely, the isostables are defined as the level sets of a particular eigenfunction of the Koopman operator. Through this approach, the isostables are unique and well-defined objects related to the asymptotic properties of the system. Also, the framework reveals that the isostables and the isochrons are two different but complementary notions which define a set of action-angle coordinates for the dynamics. In addition, an efficient algorithm for computing the isostables is obtained, which relies on the evaluation of Laplace averages along the trajectories. The method is illustrated with the excitable FitzHugh-Nagumo model and with the Lorenz model. Finally, we discuss how these methods based on the Koopman operator framework relate to the global linearization of the system and to the derivation of special Lyapunov functions.
On fixed points of permutations
Persi Diaconis; Jason Fulman; Robert Guralnick
2008-01-01
The number of fixed points of a random permutation of {1,2,…,n} has a limiting Poisson distribution. We seek a generalization, looking at other actions of the symmetric group. Restricting\\u000a attention to primitive actions, a complete classification of the limiting distributions is given. For most examples, they\\u000a are trivial – almost every permutation has no fixed points. For the usual action
Chiral properties of the fixed point action of the Schwinger model
Farchioni, F; Wohlgenannt, M
1998-01-01
We study the spectrum properties for a recently constructed fixed point lattice Dirac operator. We also consider the problem of the extraction of the fermion condensate, both by direct computation, and through the Banks-Casher formula by analyzing the density of eigenvalues of a redefined antihermitean lattice Dirac operator.
NASA Astrophysics Data System (ADS)
Edler, F.; Ederer, P.
2014-07-01
The paper describes the construction and investigation of multiple fixed-point cells usable for the calibration of thermocouples at temperatures above 1100 C. These fixed-point cells made of pure graphite are characterized by a simple construction as well as by a flexible application. The cylindrical basic mount is equipped with a central hole for the insertion of a thermocouple, and with eight drill holes containing exchangeable cartridges which surround the central bore axially symmetrically. The cartridges are filled with different metal-carbon (Me-C) eutectics: cobalt-carbon (Co-C), nickel-carbon (Ni-C), palladium-carbon (Pd-C), and rhodium-carbon (Rh-C). The melting temperatures of the different Me-C eutectics of the cartridges were compared to the melting temperatures of commonly used Me-C eutectic fixed-point cells of the Physikalisch-Technische Bundesanstalt by using a Pt/Pd thermocouple (Co-C, Ni-C) and Type B thermocouples (Pd-C, Rh-C). The uncertainties () of the emfs measured at the inflection points of the melting curves are in the order of a few V which correspond to temperature equivalents between 0.3 K and 0.6 K. Furthermore, the difference between the melting temperatures of the Co-C and Ni-C cartridges was found to be 4.2 K by using simultaneously two sets of four cartridges filled with the two materials and placed alternately in the eight outer holes of one basic mount.
Fixed point theorems and dissipative processes.
NASA Technical Reports Server (NTRS)
Hale, J. K.; Lopes, O.
1973-01-01
Operators of the type considered by Hale et al. (1972) are used to show that under certain conditions there is a fixed point in a dissipative map within a Banach space. The conditions required for the existence of this fixed point are discussed in detail. Several fixed point theorems are formulated and proved.
Imaginary fixed points can be physical.
Zhong, Fan
2012-08-01
It has been proposed that a first-order phase transition driven to happen in the metastable region exhibits scaling and universality near an instability point controlled by an instability fixed point of a ?(3) theory. However, this fixed point has an imaginary value and the renormalization-group flow of the ?(3) coupling diverges at a finite scale. Here combining a momentum-space RG analysis and a nucleation theory near the spinodal point, we show that imaginary rather than real values are physical counterintuitively and thus the imaginary fixed point does control the scaling. PMID:23005808
Higgs boson spectrum from infrared fixed point
Leung, C.N.
1985-08-01
The fixed point structure of the renormalization group equations for the scalar quartic couplings in the one and two-doublet models is studied. Masses of the physical Higgs bosons can be determined by the infrared fixed points of the quartic coupling constants. The existence of these fixed points in the two-doublet model requires the presence of a heavy fourth generation in which quarks are coupled to both doublets. Otherwise, the potential can become quartically unstable at low energies for arbitrary initial stable values of the coupling constants. 9 refs., 5 figs.
Characterizations of fixed points of quantum operations
Li Yuan [College of Mathematics and Information Science, Shaanxi Normal University, Xi'an, 710062 (China)
2011-05-15
Let {phi}{sub A} be a general quantum operation. An operator B is said to be a fixed point of {phi}{sub A}, if {phi}{sub A}(B)=B. In this note, we shall show conditions under which B, a fixed point {phi}{sub A}, implies that B is compatible with the operation element of {phi}{sub A}. In particular, we offer an extension of the generalized Lueders theorem.
Some New Asymptotic Fixed Point Theorems
Browder, Felix E.
1974-01-01
For a continuous self mapping f of a locally convex topological vector space which is locally compact (i.e., f maps a neighborhood of each point into a relatively compact set), it is shown that a sufficient condition for the existence of a fixed point is the existence of a compact attractor K0 such that each orbit under f has a point of K0 in its closure. The proof is based upon the circle of ideas of the Lefschetz fixed point theorem. PMID:16592169
Infrared fixed point in quantum Einstein gravity
S. Nagy; J. Krizsan; K. Sailer
2012-06-28
We performed the renormalization group analysis of the quantum Einstein gravity in the deep infrared regime for different types of extensions of the model. It is shown that an attractive infrared point exists in the broken symmetric phase of the model. It is also shown that due to the Gaussian fixed point the IR critical exponent $\
On fixed points of quantum gravity
Daniel F. Litim
2006-06-06
We study the short distance behaviour of euclidean quantum gravity in the light of Weinberg's asymptotic safety scenario. Implications of a non-trivial ultraviolet fixed point are reviewed. Based on an optimised renormalisation group, we provide analytical flow equations in the Einstein-Hilbert truncation. A non-trivial ultraviolet fixed point is found for arbitrary dimension. We discuss a bifurcation pattern in the spectrum of eigenvalues at criticality, and the large dimensional limit of quantum gravity. Implications for quantum gravity in higher dimensions are indicated.
47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.
Code of Federal Regulations, 2010 CFR
2010-10-01
...Interconnection of private operational fixed point-to-point microwave stations. 101...Interconnection of private operational fixed point-to-point microwave stations. Private operational fixed point-to-point microwave stations may be...
Fixed point theorems of soft contractive mappings
Murat I. Yazar; Cigdem Gunduz; Sadi Bayramov
2013-08-04
The first aim of this paper is to examine some important properties of soft metric spaces. Second is to introduce soft continuous mappings and investigate properties of soft continuous mappings. Third is to prove some fixed point theorems of soft contractive mappings on soft metric spaces.
Fixed Point Theorems for Hybrid Mappings
Kamran, Tayyab; Karapinar, Erdal
2015-01-01
We obtain some fixed point theorems for two pairs of hybrid mappings using hybrid tangential property and quadratic type contractive condition. Our results generalize some results by Babu and Alemayehu and those contained therein. In the sequel, we introduce a new notion to generalize occasionally weak compatibility. Moreover, two concrete examples are established to illuminate the generality of our results. PMID:25629089
Fixed point theorems for hybrid mappings.
Samreen, Maria; Kamran, Tayyab; Karapinar, Erdal
2015-01-01
We obtain some fixed point theorems for two pairs of hybrid mappings using hybrid tangential property and quadratic type contractive condition. Our results generalize some results by Babu and Alemayehu and those contained therein. In the sequel, we introduce a new notion to generalize occasionally weak compatibility. Moreover, two concrete examples are established to illuminate the generality of our results. PMID:25629089
Reflexive Metric Spaces The Fixed Point Property
Khamsi, Mohamed Amine
some classical known fixed point results for uniformly Lipschitzian mappings to metric spaces using a weak-topology, the world topology is a little bit abused. Usually we only focus on sequences. The inves project. 1 #12;2 Convexity in Metric Spaces When we think of linearity, we think of a vector space
Precise Point Positioning with Partial Ambiguity Fixing
Li, Pan; Zhang, Xiaohong
2015-01-01
Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate. PMID:26067196
Precise Point Positioning with Partial Ambiguity Fixing.
Li, Pan; Zhang, Xiaohong
2015-01-01
Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate. PMID:26067196
47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.
Code of Federal Regulations, 2012 CFR
2012-10-01
...private operational fixed point-to-point microwave stations. 101.137 Section 101...SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101...private operational fixed point-to-point microwave stations. Private operational...
47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.
Code of Federal Regulations, 2013 CFR
2013-10-01
...private operational fixed point-to-point microwave stations. 101.137 Section 101...SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101...private operational fixed point-to-point microwave stations. Private operational...
47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.
Code of Federal Regulations, 2011 CFR
2011-10-01
...private operational fixed point-to-point microwave stations. 101.137 Section 101...SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101...private operational fixed point-to-point microwave stations. Private operational...
47 CFR 101.137 - Interconnection of private operational fixed point-to-point microwave stations.
Code of Federal Regulations, 2014 CFR
2014-10-01
...private operational fixed point-to-point microwave stations. 101.137 Section 101...SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Technical Standards § 101...private operational fixed point-to-point microwave stations. Private operational...
Sequential conditions for fixed and periodic points
Peters, Burnis Charles
1970-01-01
. Let (X, d) be a metric space and f a selfmap of X. It is shown that a number of known theorems on the existence of fixed and periodic points are related through simple properties of the n sequence (f ) of iterates . ACMOVI. EDGEMENTS I wish... and for each x in X, the sequence (f (x)) converges to u. For a proof of the contraction mapping theorem see [5, p. llg]. A sequence (x ) in a metric space (X, d) is isometric + (s-isometric) if d(x, x + ) d(x, x ) for all m, n, p in Z (all m+p' n+p m' n...
Partial Fixed-Point Logic on Infinite Structures
Stephan Kreutzer; RWTH Aachen
2002-01-01
Abstract: We consider an alternative semantics for partial fixed-point logic (PFP). To define the fixed point of a formula in this semantics, the sequence of stages induced by the formula is considered. As soon as this sequence becomes cyclic, the set of elements contained in every stage of the cycle is taken as the fixed point. It is shown that
The Fermi liquid as a renormalization group fixed point
NASA Astrophysics Data System (ADS)
Chitov, Guennadi
1998-12-01
The renormalization-group (RG) method is applied to study interacting fermions at finite temperature. A model based on the psi4-Grassmann effective action with SU(N)-invariant short-range interaction and a rotationally invariant Fermi surface in spatial dimensions d = 2, 3 is studied. We show how the key results of the Landau Fermi liquid theory can be recovered by this finite-temperature RG technique. Applying the RG to response functions, we find the compressibility and the spin susceptibility as solutions of the RG flow equations. We discuss subtleties associated with the symmetry properties of the four-point vertex (the implications of the Pauli principle). We point out distinctions between three quantities: the bare interaction of the low-energy effective action, the Landau function and the forward scattering vertex. The bare interaction of the effective action is not a RG fixed point, but a common starting point of the flow trajectories of two limiting forms of the four-point vertex. We have derived RG equations for the Landau channel that take into account both contributions of the direct (ZS) and the exchange (ZS') particle-hole graphs at one-loop level. The basic quantities of Fermi Liquid theory, the Landau interaction function and the forward scattering vertex, are calculated as fixed points of these flows in terms of the effective action's interaction function. The classic derivations of Fermi Liquid theory applying the Bethe-Salpeter equation and other analogous approaches, tantamount to some sort of RPA-type (decoupled) approximation, neglect the zero-angle singularity in the ZS' graph. As a consequence, the antisymmetry of the forward scattering vertex is not guaranteed in the final result, and the RPA sum rule must be imposed by hand on the components of the Landau function to satisfy the Pauli principle. This sum rule, not indispensable in the original phenomenological formulation of the Landau FLT, is equivalent, from the RG point of view, to a fine tuning of the effective interaction. Our results show that the strong interference of the direct and exchange processes of the particle-hole scattering near zero angle invalidates the RPA (decoupled) approximation in this region, resulting in temperature-dependent narrow-angle anomalies in the Landau function and scattering vertex, revealed by the RG analysis. In the present RG approach the Pauli principle is automatically satisfied. As follows from the RG solution, the amplitude sum rule, being an artefact of the RPA approximation, is not needed to respect statistics and, moreover, is not valid.
Galois Connections and Fixed Point Calculus Roland Backhouse
Backhouse, Roland
Galois Connections and Fixed Point Calculus Roland Backhouse October 15, 2001 Abstract Fixed point the theory and application of Galois connections between partially ordered sets. In par- ticular, the intimate relation between Galois connections and xed point equations is amply demonstrated. School
Fixed points for centralizers and Morita's Michael Handel
Vogtmann, Karen
is either an attracting or repelling fixed point for f : D D. Let G G denote the finite in- dex subgroup #12;Proving the Global Fixed Point Theorem By doubling we can work in S2 with invari- ant equator that has alternating attractors {pi} and repellers {qi}. U := basin of attraction f
On Fixed-point theorems in Intuitionistic Fuzzy metric Space
T. K. Samanta; Sumit Mohinta; Iqbal H. Jebril
2010-11-06
In this paper, first we have established two sets of sufficient conditions for a mapping to have unique fixed point in a intuitionistic fuzzy metric space and then we have redefined the contraction mapping in a intuitionistic fuzzy metric space and thereafter we proved the Banach Fixed Point theorem.
FIXED POINT SETS OF PARABOLIC ISOMETRIES OF CAT(0)-SPACES
Fujiwara, Koji
FIXED POINT SETS OF PARABOLIC ISOMETRIES OF CAT(0)-SPACES KOJI FUJIWARA, KOICHI NAGANO, AND TAKASHI CAT(0)-space. We show that the radius of the fixed point set is at most /2, and study its centers of Theorem 1.1 10 4. Dimension of Tits ideal boundaries 11 5. CAT(1)-spaces of small diameter 12 5.1. Small
A new compact fixed-point blackbody furnace
NASA Astrophysics Data System (ADS)
Hiraka, K.; Yamada, Y.; Ishii, J.; Oikawa, H.; Shimizu, T.; Kadoya, S.; Kobayashi, T.
2013-09-01
More and more NMIs are realizing their primary scale themselves with fixed-point blackbodies as their reference standard. However, commercially available fixed-point blackbody furnaces of sufficient quality are not always easy to obtain. CHINO Corp. and NMIJ, AIST jointly developed a new compact fixed-point blackbody furnace. The new furnace has such features as 1) improved temperature uniformity when compared to previous products, enabling better plateau quality, 2) adoption of the hybrid fixed-point cell structure with internal insulation to improve robustness and thereby to extend lifetime, 3) easily ejectable and replaceable heater unit and fixed-point cell design, leading to reduced maintenance cost, 4) interchangeability among multiple fixed points from In to Cu points. The replaceable cell feature facilitates long term maintenance of the scale through management of a group of fixed-point cells of the same type. The compact furnace is easily transportable and therefore can also function as a traveling standard for disseminating the radiation temperature scale, and for maintaining the scale at the secondary level and industrial calibration laboratories. It is expected that the furnace will play a key role of the traveling standard in the anticipated APMP supplementary comparison of the radiation thermometry scale.
A new compact fixed-point blackbody furnace
Hiraka, K.; Oikawa, H.; Shimizu, T.; Kadoya, S.; Kobayashi, T. [CHINO CORPORATION, Itabashi, Tokyo (Japan)] [CHINO CORPORATION, Itabashi, Tokyo (Japan); Yamada, Y.; Ishii, J. [National Metrology Institute of Japan, AIST, Tsukuba, Ibaraki (Japan)] [National Metrology Institute of Japan, AIST, Tsukuba, Ibaraki (Japan)
2013-09-11
More and more NMIs are realizing their primary scale themselves with fixed-point blackbodies as their reference standard. However, commercially available fixed-point blackbody furnaces of sufficient quality are not always easy to obtain. CHINO Corp. and NMIJ, AIST jointly developed a new compact fixed-point blackbody furnace. The new furnace has such features as 1) improved temperature uniformity when compared to previous products, enabling better plateau quality, 2) adoption of the hybrid fixed-point cell structure with internal insulation to improve robustness and thereby to extend lifetime, 3) easily ejectable and replaceable heater unit and fixed-point cell design, leading to reduced maintenance cost, 4) interchangeability among multiple fixed points from In to Cu points. The replaceable cell feature facilitates long term maintenance of the scale through management of a group of fixed-point cells of the same type. The compact furnace is easily transportable and therefore can also function as a traveling standard for disseminating the radiation temperature scale, and for maintaining the scale at the secondary level and industrial calibration laboratories. It is expected that the furnace will play a key role of the traveling standard in the anticipated APMP supplementary comparison of the radiation thermometry scale.
Coincidence and fixed points in symmetric spaces under strict contractions
NASA Astrophysics Data System (ADS)
Imdad, M.; Ali, Javid; Khan, Ladlay
2006-08-01
Some common fixed point theorems due to Aamri and El Moutawakil [M. Aamri, D. El Moutawakil, Some new common fixed point theorems under strict contractive conditions, J. Math. Anal. Appl. 270 (2002) 181-188] and Pant and Pant [R.P. Pant, V. Pant, Common fixed points under strict contractive conditions, J. Math. Anal. Appl. 248 (2000) 327-332] proved for strict contractive mappings in metric spaces are extended to symmetric (semi-metric) spaces under tight conditions. Some related results are derived besides discussing illustrative examples which establish the utility of results proved in this note.
IR fixed points in SU (3) gauge theories
NASA Astrophysics Data System (ADS)
Ishikawa, K.-I.; Iwasaki, Y.; Nakayama, Yu; Yoshie, T.
2015-09-01
We propose a novel RG method to specify the location of the IR fixed point in lattice gauge theories and apply it to the SU (3) gauge theories with Nf fundamental fermions. It is based on the scaling behavior of the propagator through the RG analysis with a finite IR cutoff, which we cannot remove in the conformal field theories in sharp contrast to the confining theories. The method also enables us to estimate the anomalous mass dimension in the continuum limit at the IR fixed point. We perform the program for Nf = 16 , 12 , 8 and Nf = 7 and indeed identify the location of the IR fixed points in all cases.
Is renormalized entanglement entropy stationary at RG fixed points?
NASA Astrophysics Data System (ADS)
Klebanov, Igor R.; Nishioka, Tatsuma; Pufu, Silviu S.; Safdi, Benjamin R.
2012-10-01
The renormalized entanglement entropy (REE) across a circle of radius R has been proposed as a c-function in Poincaré invariant (2 + 1)-dimensional field theory. A proof has been presented of its monotonic behavior as a function of R, based on the strong subadditivity of entanglement entropy. However, this proof does not directly establish stationarity of REE at conformal fixed points of the renormalization group. In this note we study the REE for the free massive scalar field theory near the UV fixed point described by a massless scalar. Our numerical calculation indicates that the REE is not stationary at the UV fixed point.
FIXED POINTS OF CONTRACTIVE MULTIVALUED MAPS
L. G ORNIEWICZ; S. A. MARANO; M. SLOSARSKI
For a class of contractive multivalued maps dened on a complete absolute retract and with closed bounded values, the set of xed points is proved to be an absolute retract. This result unies and extends to arbitrary absolute retracts both Theorem 1 by Ricceri (Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur. (8)81 (1987), 283{286) and Theorem 1
On the Expressive Power of Monadic Least Fixed Point Logic
Nicole Schweikardt
2004-01-01
Abstract Monadic least fixed point logic MLFP is a natural logic whose expressiveness lies between that of first-order logic FO and monadic,second-order logic MSO. In this paper we take a closer look at the expressive power of MLFP. Our results are (1) MLFP can describe graph properties beyond any fixed level of the monadic,second-
Heterogeneous Fixed Points with Application to Points-to Analysis
Kanade, Aditya
functions monotonically increase in some variables and decrease in others. Emami's (intraprocedural) points. In section 2, we show that monotonicity of functions in Emami's points- to analysis is not obvious. We of functions in Emami's points-to analysis is not obvious. We then reformulate the analysis to explicate
Orthomodular lattice obtained from addressing a fixed point
NASA Astrophysics Data System (ADS)
Gunji, Yukio-Pegio; Ito, Gen
1999-02-01
One of us previously proposed a model of internal measurement that is not only an interaction between internal elements but also involves the notion of an indefinite observer measuring the interaction. In this model, all interactions encompass the notion of detection. The latter can be expressed as a process generating a contradiction. Hereby a fixed point becomes invalid after inducing the contradiction. Instead of embedding this process as an instance along the time axis, we here represent the logical jump via a contradiction (fixed point). Specifically a new operation is defined which replaces the operation by which a fixed point is induced, and we show that both a set as a fixed point and this particular operation on a set can give rise to an orthomodular lattice that is a model of quantum logic. The new procedure is a mixture of inducing a fixed point and addressing a fixed point. It can be compared to mixing up indicating an element with indicating a set consisting of elements, that is, to Russel’s paradox. Finally, we point out that orthomodularity can ubiquitously be found in the evolutionary complex systems because it is generally relevant to resolving a paradox or a logical jump.
Proceedings 8th Workshop on Fixed Points in Computer Science
Miller, Dale; 10.4204/EPTCS.77
2012-01-01
This volume contains the proceedings of the Eighth Workshop on Fixed Points in Computer Science which took place on 24 March 2012 in Tallinn, Estonia as an ETAPS-affiliated workshop. Past workshops have been held in Brno (1998, MFCS/CSL workshop), Paris (2000, LC workshop), Florence (2001, PLI workshop), Copenhagen (2002, LICS (FLoC) workshop), Warsaw (2003, ETAPS workshop), Coimbra (2009, CSL workshop), and Brno (2010, MFCS-CSL workshop). Fixed points play a fundamental role in several areas of computer science and logic by justifying induction and recursive definitions. The construction and properties of fixed points have been investigated in many different frameworks such as: design and implementation of programming languages, program logics, and databases. The aim of this workshop is to provide a forum for researchers to present their results to those members of the computer science and logic communities who study or apply the theory of fixed points.
52. Fixed Span, Top Chord at Panel Point 6; diagonal ...
52. Fixed Span, Top Chord at Panel Point 6; diagonal member goes to intermediate connection 7 & then to bottom chord at 8; looking ESE. - Pacific Shortline Bridge, U.S. Route 20,spanning Missouri River, Sioux City, Woodbury County, IA
A new algorithm for fixed point quantum search
Tathagat Tulsi; LOV K. GROVER; Apoorva Patel
2005-01-01
The standard quantum search lacks a feature, enjoyed by many classical algorithms, of having a fixed point, i.e. monotonic convergence towards the solution. Recently a fixed point quantum search algorithm has been discovered, referred to as the Phase-$\\\\pi\\/3$ search algorithm, which gets around this limitation. While searching a database for a target state, this algorithm reduces the error probability from
Stray thermal influences in zinc fixed-point cells
Rudtsch, S.; Aulich, A.; Monte, C. [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin (Germany)] [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin (Germany)
2013-09-11
The influence of thermal effects is a major uncertainty contribution to the calibration of Standard Platinum Resistance Thermometers (SPRTs) in fixed-point cells. Axial heat losses strongly depend on the fixed-point temperature, constructional details of cells and SPRTs and the resulting heat transfer between cell, thermometer, furnace and environment. At the zinc point contributions by heat conduction and thermal radiation must be considered. Although the measurement of temperature gradients in the re-entrant well of a fixed-point cell provides very important information about the influence of axial heat losses, further investigations are required for a reliable estimate of the resulting uncertainty contribution. It is shown that specific modifications of a zinc fixed-point cell, following generally accepted principles, may result in systematic deviations of the measured fixed-point temperatures larger than typically stated in the uncertainty budget of National Metrology Institutes (NMIs). The underlying heat transport processes are investigated and the consequences for the construction of zinc cells are discussed.
Fixed point theory of iterative excitation schemes in NMR
NASA Astrophysics Data System (ADS)
Tycko, R.; Pines, A.; Guckenheimer, J.
1985-09-01
Iterative schemes for NMR have been developed by several groups. A theoretical framework based on mathematical dynamics is described for such iterative schemes in nonlinear NMR excitation. This is applicable to any system subjected to coherent radiation or other experimentally controllable external forces. The effect of the excitation, usually a pulse sequence, can be summarized by a propagator or superpropagator (U). The iterative scheme (F) is regarded as a map of propagator space into itself, Un+1=FUn. One designs maps for which a particular propagator ? or set of propagators {?} is a fixed point or invariant set. The stability of the fixed points along various directions is characterized by linearizing F around the fixed point, in analogy to the evaluation of an average Hamiltonian. Stable directions of fixed points typically give rise to broadband behavior (in parameters such as frequency, rf amplitude, or coupling constants) and unstable directions to narrowband behavior. The dynamics of the maps are illustrated by ``basin images'' which depict the convergence of points in propagator space to the stable fixed points. The basin images facilitate the optimal selection of initial pulse sequences to ensure convergence to a desired excitation. Extensions to iterative schemes with several fixed points are discussed. Maps are shown for the propagator space SO(3) appropriate to iterative schemes for isolated spins or two-level systems. Some maps exhibit smooth, continuous dynamics whereas others have basin images with complex and fractal structures. The theory is applied to iterative schemes for broadband and narrowband ? (population inversion) and ?/2 rotations, MLEV and Waugh spin decoupling sequences, selective n-quantum pumping, and bistable excitation.
Brief Announcement: Consistent Fixed Points and Negative Gain
NASA Astrophysics Data System (ADS)
Acharya, Hrishikesh B.; Elmallah, Ehab S.; Gouda, Mohamed G.
We discuss the stabilization properties of networks that are composed of "displacement elements". Each displacement element is defined by an integer K, called the displacement of the element, an input variable x, and an output variable y, where the values of x and y are non-negative integers. An execution step of this element assigns to y the maximum of 0 and K + x. The objective of our discussion is to demonstrate that two principles play an important role in ensuring that a network N is stabilizing, i.e. starting from any global state, network N is guaranteed to reach a global fixed point. The first principle, named consistent fixed points, states that if a variable is written by two subnetworks of N, then the values of this variable, when these two subnetworks reach fixed points, are equal. The second principle, named negative gain, states that the sum of displacements along every directed loop in network N is negative.
Some Unique Fixed Point Theorems in Multiplicative Metric Spaces
Muhammad Sarwar; Badshah-e-Rome
2014-12-29
\\"{O}zavsar and Cevikel(Fixed point of multiplicative contraction mappings on multiplicative metric space.arXiv:1205.5131v1 [math.GN] 23 may 2012)initiated the concept of the multiplicative metric space in such a way that the usual triangular inequality is replaced by "multiplicative triangle inequality $d(x,y)\\leq d(x,z).d(z,y)$ for all $x,y,z\\in X$". In this manuscript, we discussed some unique fixed point theorems in the context of multiplicative metric spaces. The established results carry some well known results from the literature to multiplicative metric space. We note that some fixed point theorems can be deduced in multiplicative metric space by using the established results. Appropriate examples are also given.
Cobalt-Carbon Eutectic Fixed Point for Contact Thermometry
NASA Astrophysics Data System (ADS)
Todd, A. D. W.; Gotoh, M.; Woods, D. J.; Hill, K. D.
2011-01-01
Two Co-C eutectic fixed points were constructed for thermocouple calibration. The eutectic fixed points were measured with a Pt/Pd thermocouple calibrated at the freezing temperatures of Sn, Zn, Al, Ag, and Au. A temperature of (1323.99 ± 0.52) °C ( k = 2) was determined via this method. The cell design allowed filling to be accomplished in a single step. Each cell was held above 1300 °C for at least 42 h and was subjected to at least 20 melt/freeze cycles with no mechanical failure occurring.
A fixed point for truncated quantum Einstein gravity
Forgács, Péter
2002-01-01
A perturbative quantum theory of the two Killing vector reduction of Einstein gravity is constructed. Although the reduced theory inherits from the full one the lack of standard perturbative renormalizability, we show that strict cutoff independence can be regained to all loop orders in a space of Lagrangians differing only by a field dependent conformal factor. A closed formula is obtained for the beta functional governing the flow of this conformal factor. The flow possesses a unique fixed point at which the trace anomaly is shown to vanish. The approach to the fixed point is compatible with Weinberg's ``asymptotic safety'' scenario.
A fixed point for truncated quantum Einstein gravity
P. Forgacs; M. Niedermaier
2002-07-02
A perturbative quantum theory of the two Killing vector reduction of Einstein gravity is constructed. Although the reduced theory inherits from the full one the lack of standard perturbative renormalizability, we show that strict cutoff independence can be regained to all loop orders in a space of Lagrangians differing only by a field dependent conformal factor. A closed formula is obtained for the beta functional governing the flow of this conformal factor. The flow possesses a unique fixed point at which the trace anomaly is shown to vanish. The approach to the fixed point is compatible with Weinberg's ``asymptotic safety'' scenario.
An order theoretic approach in fixed point theory
Yaé Ulrich Gaba
2014-11-07
In the present article, we show the existence of a coupled fixed point for an order preserving mapping in a preordered left K-complete quasi-pseudometric space using a preorder induced by an appropriate function. We also define the concept of left-weakly related mappings on a preordered space and discuss common coupled fixed points for two and three left-weakly related mappings in the same space. Similar results are given for right-weakly related mappings, the dual notion of left-weakly related mappings.
On R-symmetric Fixed Points and Superconformality
Antoniadis, Ignatios; Buican, Matthew
2011-05-15
An important unanswered question in quantum field theory is to understand precisely under which conditions scale invariance implies invariance under the full conformal group. While the general answer in two dimensions has been known for over 20 years, a precise nonperturbative relation between scale and conformal invariance in higher dimensions has been lacking. In this note, we specialize to four dimensions and give a full quantum mechanical proof that certain unitary R-symmetric fixed points are necessarily superconformal. Among other consequences, this result implies that the infrared fixed points of N=1 supersymmetric quantum chromodynamics are superconformal.
Measurement of thermodynamic temperature of high temperature fixed points
Gavrilov, V. R.; Khlevnoy, B. B.; Otryaskin, D. A.; Grigorieva, I. A.; Samoylov, M. L.; Sapritsky, V. I.
2013-09-11
The paper is devoted to VNIIOFI's measurements of thermodynamic temperature of the high temperature fixed points Co-C, Pt-C and Re-C within the scope of the international project coordinated by the Consultative Committee for Thermometry working group 5 'Radiation Thermometry'. The melting temperatures of the fixed points were measured by a radiance mode radiation thermometer calibrated against a filter radiometer with known irradiance spectral responsivity via a high temperature black body. This paper describes the facility used for the measurements, the results and estimated uncertainties.
Fixed Point Theorems in Logic Programming Mohamed A. Khamsi1
Khamsi, Mohamed Amine
, Universite Mohamed V, Faculte des Sciences, Rabat, Morocco. email:1 mohamed@math.utep.edu URL:1 http of Mathematical Sciences, University of Texas at El Paso, El Paso, TX 79968. 2Departement de Mathematiques- phistication applied to various sciences has changed drastically in recent years. Fixed point theory furnishes
THE HOMOTOPY FIXED POINT SPECTRA OF PROFINITE GALOIS EXTENSIONS
Behrens, Mark
THE HOMOTOPY FIXED POINT SPECTRA OF PROFINITE GALOIS EXTENSIONS MARK BEHRENS1 AND DANIEL G. DAVIS2 Abstract. Let E be a k-local profinite G-Galois extension of an E-ring spectrum A (in the sense of Rognes of Rognes's Galois correspondence extends to the profinite setting. We show that the function spectrum FA
On the expressive power of monadic least fixed point logic
Nicole Schweikardt
2006-01-01
Monadic least fixed point logic MLFP is a natural logic whose expressiveness lies between that of first-order logic FO and monadic second-order logic MSO. In this paper we take a closer look at the expressive power of MLFP. Our results are
LOCAL FIXED POINT INDICES OF ITERATIONS OF PLANAR MAPS
Romero Ruiz del Portal, Francisco
LOCAL FIXED POINT INDICES OF ITERATIONS OF PLANAR MAPS GRZEGORZ GRAFF, PIOTR NOWAK, it is usually difficult to establish the exact form of the indices for a given map. Never- theless, during the last years the description of indices was given for many important classes of maps such as: planar
Fixed Point Problems for Linear Transformations on Pythagorean Triples
ERIC Educational Resources Information Center
Zhan, M.-Q.; Tong, J.-C.; Braza, P.
2006-01-01
In this article, an attempt is made to find all linear transformations that map a standard Pythagorean triple (a Pythagorean triple [x y z][superscript T] with y being even) into a standard Pythagorean triple, which have [3 4 5][superscript T] as their fixed point. All such transformations form a monoid S* under matrix product. It is found that S*…
Newspaper Article Extraction Using Hierarchical Fixed Point Model
Roy, Sumantra Dutta
Newspaper Article Extraction Using Hierarchical Fixed Point Model Anukriti Bansal, Santanu,sumantra.dutta.roy,jbsrivas}@gmail.com Abstract--This paper presents a novel learning based frame- work to extract articles from newspaper images and features of each block to learn the layout of newspaper images and attains a contraction mapping to assign
A Discontinuity in the Distribution of Fixed Point Sums
Bender, Ed
A Discontinuity in the Distribution of Fixed Point Sums Edward A. Bender Department of Mathematics a sharp discontinuity in the neigh- borhood of r = n. We explain this discontinuity and study the possible existence of other discontinuities in f(n, r) for permutations. We generalize our results to other families
Chaotic associative recalls for fixed point attractor patterns
Liang Zhao; J. C. G. Caceres; H. Szu
2003-01-01
Human perception is a complex nonlinear dynamics. On the one hand it is periodic dynamics and on the other hand it is chaotic. Thus, we wish to propose a hybrid-the spatial chaotic dynamics for the associative recall to retrieve patterns, similar to Walter Freeman's discovery, and the fixed point dynamics for memory stage, similar to Hopfield and Grossberg's discoveries. In
Fixed Point Theorems with Applications to Economics and Game Theory
Kim C. Border
1985-01-01
One of the problems in economics that economists have devoted a considerable amount of attention in prevalent years has been to ensure consistency in the models they employ. Assuming markets to be generally in some state of equilibrium, it is asked under what circumstances such equilibrium is possible. The fundamental mathematical tools used to address this concern are fixed point
New triple fixed point results in cone metric spaces
NASA Astrophysics Data System (ADS)
Abusalim, Sahar Mohammad; Noorani, Mohd Salmi Md
2015-05-01
The conception of c-distance on a cone metric space was introduced in 2011. In this paper, some tripled fixed points theorems for some type of contraction mapping are evidenced in a cone metric space by using this concept of c-distance. We also provide examples to illustrate our obtained results.
Fixed point theorems for generalized contractions in ordered metric spaces
NASA Astrophysics Data System (ADS)
O'Regan, Donal; Petrusel, Adrian
2008-05-01
The purpose of this paper is to present some fixed point results for self-generalized contractions in ordered metric spaces. Our results generalize and extend some recent results of A.C.M. Ran, M.C. Reurings [A.C.M. Ran, MEC. Reurings, A fixed point theorem in partially ordered sets and some applications to matrix equations, Proc. Amer. Math. Soc. 132 (2004) 1435-1443], J.J. Nieto, R. Rodríguez-López [J.J. Nieto, R. Rodríguez-López, Contractive mapping theorems in partially ordered sets and applications to ordinary differential equations, Order 22 (2005) 223-239; J.J. Nieto, R. Rodríguez-López, Existence and uniqueness of fixed points in partially ordered sets and applications to ordinary differential equations, Acta Math. Sin. (Engl. Ser.) 23 (2007) 2205-2212], J.J. Nieto, R.L. Pouso, R. Rodríguez-López [J.J. Nieto, R.L. Pouso, R. Rodríguez-López, Fixed point theorem theorems in ordered abstract sets, Proc. Amer. Math. Soc. 135 (2007) 2505-2517], A. Petrusel, I.A. Rus [A. Petrusel, I.A. Rus, Fixed point theorems in ordered L-spaces, Proc. Amer. Math. Soc. 134 (2006) 411-418] and R.P. Agarwal, M.A. El-Gebeily, D. O'Regan [R.P. Agarwal, M.A. El-Gebeily, D. O'Regan, Generalized contractions in partially ordered metric spaces, Appl. Anal., in press]. As applications, existence and uniqueness results for Fredholm and Volterra type integral equations are given.
Non-Thermal Fixed Point in a Holographic Superfluid
Carlo Ewerz; Thomas Gasenzer; Markus Karl; Andreas Samberg
2015-05-11
We study the far-from-equilibrium dynamics of a (2+1)-dimensional superfluid at finite temperature and chemical potential using its holographic description in terms of a gravitational system in 3+1 dimensions. Starting from various initial conditions corresponding to ensembles of vortex defects we numerically evolve the system to long times. At intermediate times the system exhibits Kolmogorov scaling the emergence of which depends on the choice of initial conditions. We further observe a universal late-time regime in which the occupation spectrum and different length scales of the superfluid exhibit scaling behaviour. We study these scaling laws in view of superfluid turbulence and interpret the universal late-time regime as a non-thermal fixed point of the dynamical evolution. In the holographic superfluid the non-thermal fixed point can be understood as a stationary point of the classical equations of motion of the dual gravitational description.
Comparison of Fixed Point Realisations between Inmetro and PTB
NASA Astrophysics Data System (ADS)
Santiago, J. F. N.; Petkovic, S. G.; Teixeira, R. N.; Noatsch, U.; Thiele-Krivoj, B.
2003-09-01
An interlaboratory comparison in the temperature range between -190 °C and 420 °C was organised between the National Institute of Quality, Normalisation and Industrial Quality (Inmetro), Brazil, and the Physikalisch Technische Bundesanstalt (PTB), Germany. This comparison followed the same protocol as the EUROMET project 552 comparison and was carried out in the years 2001-2002. A standard platinum resistance thermometer (SPRT) of 25 ? was calibrated at the temperature fixed points of Ar, Hg, the triple point of water (TWP), Ga, In, Sn and Zn, with at least three realisations of each fixed point at both institutes. The uncertainty evaluation is given by Inmetro and some differences in the calibration procedures or in the measuring instruments used are described. The agreement between the results of laboratories was not in all cases within the combined uncertainties. Results of other comparisons are presented, which give additional information on the equivalence of the realised temperature scales.
New protocol for the realization of the triple points of cryogenic gases as temperature fixed points
NASA Astrophysics Data System (ADS)
Fellmuth, B.
2013-09-01
An improved protocol or measurement program is presented for the realization of the triple points of cryogenic gases as temperature fixed points. The protocol contains general recommendations in different directions: determination of the thermal parameters of the fixed-point cells containing the samples and of the apparatus, measurement conditions, series of measurements, reporting of data, establishment of an uncertainty budget, especially the reliable estimation of static and dynamic temperature-measurement errors. Such a detailed protocol is necessary for reaching the highest metrological level due to the special properties of the cryogenic gases as fixed-point substances. Considering the newest developments, the state-of-the-art level of the realization of the low-temperature fixed points is described.
Gravity Duals of Lifshitz-like Fixed Points
Kachru, Shamit; Mulligan, Michael
2008-01-01
We find candidate macroscopic gravity duals for scale-invariant but non-Lorentz invariant fixed points, which do not have particle number as a conserved quantity. We compute two-point correlation functions which exhibit novel behavior relative to their AdS counterparts, and find holographic renormalization group flows to conformal field theories. Our theories are characterized by a dynamical critical exponent $z$, which governs the anisotropy between spatial and temporal scaling $t \\to \\lambda^z t$, $x \\to \\lambda x$; we focus on the case with $z=2$. Such theories describe multicritical points in certain magnetic materials and liquid crystals, and have been shown to arise at quantum critical points in toy models of the cuprate superconductors. This work can be considered a small step towards making useful dual descriptions of such critical points.
Gravity Duals of Lifshitz-like Fixed Points
Shamit Kachru; Xiao Liu; Michael Mulligan
2008-08-25
We find candidate macroscopic gravity duals for scale-invariant but non-Lorentz invariant fixed points, which do not have particle number as a conserved quantity. We compute two-point correlation functions which exhibit novel behavior relative to their AdS counterparts, and find holographic renormalization group flows to conformal field theories. Our theories are characterized by a dynamical critical exponent $z$, which governs the anisotropy between spatial and temporal scaling $t \\to \\lambda^z t$, $x \\to \\lambda x$; we focus on the case with $z=2$. Such theories describe multicritical points in certain magnetic materials and liquid crystals, and have been shown to arise at quantum critical points in toy models of the cuprate superconductors. This work can be considered a small step towards making useful dual descriptions of such critical points.
Chiral-scale perturbation theory about an infrared fixed point
NASA Astrophysics Data System (ADS)
Crewther, R. J.; Tunstall, Lewis C.
2014-06-01
We review the failure of lowest order chiral SU(3)L ×SU(3)R perturbation theory ?PT3 to account for amplitudes involving the f0(500) resonance and O(mK) extrapolations in momenta. We summarize our proposal to replace ?PT3 with a new effective theory ?PT? based on a low-energy expansion about an infrared fixed point in 3-flavour QCD. At the fixed point, the quark condensate ?q?q?vac ? 0 induces nine Nambu-Goldstone bosons: ?,K,? and a QCD dilaton ? which we identify with the f0(500) resonance. We discuss the construction of the ?PT? Lagrangian and its implications for meson phenomenology at low-energies. Our main results include a simple explanation for the ?I = 1/2 rule in K-decays and an estimate for the Drell-Yan ratio in the infrared limit.
Banks-Zaks fixed point analysis in momentum subtraction schemes
J. A. Gracey; R. M. Simms
2015-04-01
We analyse the critical exponents relating to the quark mass anomalous dimension and beta-function at the Banks-Zaks fixed point in Quantum Chromodynamics (QCD) in a variety of representations for the quark in the momentum subtraction (MOM) schemes of Celmaster and Gonsalves. For a specific range of values of the number of quark flavours, estimates of the exponents appear to be scheme independent. Using the recent five loop modified minimal subtraction (MSbar) scheme quark mass anomalous dimension and estimates of the fixed point location we estimate the associated exponent as 0.263-0.268 for the SU(3) colour group and 12 flavours when the quarks are in the fundamental representation.
Banks-Zaks fixed point analysis in momentum subtraction schemes
Gracey, J A
2015-01-01
We analyse the critical exponents relating to the quark mass anomalous dimension and beta-function at the Banks-Zaks fixed point in Quantum Chromodynamics (QCD) in a variety of representations for the quark in the momentum subtraction (MOM) schemes of Celmaster and Gonsalves. For a specific range of values of the number of quark flavours, estimates of the exponents appear to be scheme independent. Using the recent five loop modified minimal subtraction (MSbar) scheme quark mass anomalous dimension and estimates of the fixed point location we estimate the associated exponent as 0.263-0.268 for the SU(3) colour group and 12 flavours when the quarks are in the fundamental representation.
Fixed points, stable manifolds, weather regimes, and their predictability
Deremble, Bruno; D'Andrea, Fabio; Ghil, Michael
2009-01-01
In a simple, one-layer atmospheric model, we study the links between low-frequency variability and the model’s fixed points in phase space. The model dynamics is characterized by the coexistence of multiple ''weather regimes.'' To investigate the transitions from one regime to another, we focus on the identification of stable manifolds associated with fixed points. We show that these manifolds act as separatrices between regimes. We track each manifold by making use of two local predictability measures arising from the meteorological applications of nonlinear dynamics, namely, ''bred vectors'' and singular vectors. These results are then verified in the framework of ensemblemore »forecasts issued from clouds (ensembles) of initial states. The divergence of the trajectories allows us to establish the connections between zones of low predictability, the geometry of the stable manifolds, and transitions between regimes.« less
Asymptotics of Fixed Point Distributions for Inexact Monte Carlo Algorithms
M. A. Clark; A. D. Kennedy
2007-10-18
We introduce a simple general method for finding the equilibrium distribution for a class of widely used inexact Markov Chain Monte Carlo algorithms. The explicit error due to the non-commutivity of the updating operators when numerically integrating Hamilton's equations can be derived using the Baker-Campbell-Hausdorff formula. This error is manifest in the conservation of a ``shadow'' Hamiltonian that lies close to the desired Hamiltonian. The fixed point distribution of inexact Hybrid algorithms may then be derived taking into account that the fixed point of the momentum heatbath and that of the molecular dynamics do not coincide exactly. We perform this derivation for various inexact algorithms used for lattice QCD calculations.
Fixed points, stable manifolds, weather regimes, and their predictability
Deremble, Bruno [Laboratoire de Meteorologie Dynamique (CNRS and IPSL), Paris (France); D'Andrea, Fabio [Laboratoire de Meteorologie Dynamique (CNRS and IPSL), Paris (France); Ghil, Michael [Univ. of California, Los Angeles, CA (United Staes). Atmospheric and Oceanic Sciences and Inst. of Geophysics and Planetary Physics
2009-01-01
In a simple, one-layer atmospheric model, we study the links between low-frequency variability and the model’s fixed points in phase space. The model dynamics is characterized by the coexistence of multiple ''weather regimes.'' To investigate the transitions from one regime to another, we focus on the identification of stable manifolds associated with fixed points. We show that these manifolds act as separatrices between regimes. We track each manifold by making use of two local predictability measures arising from the meteorological applications of nonlinear dynamics, namely, ''bred vectors'' and singular vectors. These results are then verified in the framework of ensemble forecasts issued from clouds (ensembles) of initial states. The divergence of the trajectories allows us to establish the connections between zones of low predictability, the geometry of the stable manifolds, and transitions between regimes.
Renormalization Fixed Point of the KPZ Universality Class
NASA Astrophysics Data System (ADS)
Corwin, Ivan; Quastel, Jeremy; Remenik, Daniel
2015-08-01
The one dimensional Kardar-Parisi-Zhang universality class is believed to describe many types of evolving interfaces which have the same characteristic scaling exponents. These exponents lead to a natural renormalization/rescaling on the space of such evolving interfaces. We introduce and describe the renormalization fixed point of the Kardar-Parisi-Zhang universality class in terms of a random nonlinear semigroup with stationary independent increments, and via a variational formula. Furthermore, we compute a plausible formula the exact transition probabilities using replica Bethe ansatz. The semigroup is constructed from the Airy sheet, a four parameter space-time field which is the Airy process in each of its two spatial coordinates. Minimizing paths through this field describe the renormalization group fixed point of directed polymers in a random potential. At present, the results we provide do not have mathematically rigorous proofs, and they should at most be considered proposals.
The computational core and fixed point organization in Boolean networks
NASA Astrophysics Data System (ADS)
Correale, L.; Leone, M.; Pagnani, A.; Weigt, M.; Zecchina, R.
2006-03-01
In this paper, we analyse large random Boolean networks in terms of a constraint satisfaction problem. We first develop an algorithmic scheme which allows us to prune simple logical cascades and underdetermined variables, returning thereby the computational core of the network. Second, we apply the cavity method to analyse the number and organization of fixed points. We find in particular a phase transition between an easy and a complex regulatory phase, the latter being characterized by the existence of an exponential number of macroscopically separated fixed point clusters. The different techniques developed are reinterpreted as algorithms for the analysis of single Boolean networks, and they are applied in the analysis of and in silico experiments on the gene regulatory networks of baker's yeast (Saccharomyces cerevisiae) and the segment-polarity genes of the fruitfly Drosophila melanogaster.
Thermal analysis on the realization of the tin fixed point
NASA Astrophysics Data System (ADS)
Tsai, S. F.
2013-09-01
A study on the thermal analysis of a new tin fixed-point open cell within a new three-zone furnace was carried out. The stability at the setting temperatures of liquid-solid coexisting together with some degree Celsius lower and higher than the tin fixed point; and the axial uniformity of furnace while tin is still in solid phase were investigated and analyzed. The impurities effect on the depression in temperature was investigated in terms of ?T (Tobserved-T1/F=0) and the inverse of the melted fraction (1/F) relationship during the melting and the following freezing realizations at various temperature settings of furnace. These thermal analysis results were also compared with those estimated by the CCT-WG1 recommended SIE (sum of individual estimates) method, which leads to a temperature correction along with a corresponding uncertainty through the individual impurity content detected by GDMS (glow discharge mass spectrometry).
Fixed points of multiplicative contraction mappings on multiplicative metric spaces
Muttalip Ozavsar; Adem Cengiz Cevikel
2012-05-23
In this paper, we first discussed multiplicative metric mapping by giving some topological properties of the relevant multiplicative metric space. As an interesting result of our discussions, we observed that the set of positive real numbers $\\mathbb{R}_+$ is a complete multiplicative metric space with respect to the multiplicative absolute value function. Furthermore, we introduced concept of multiplicative contraction mapping and proved some fixed point theorems of such mappings on complete multiplicative metric spaces
Expressive Equivalence of Least and Inflationary Fixed-Point Logic
Stephan Kreutzer; RWTH Aachen
2002-01-01
We study the relationship between least and inflationary fixed-point logic. By results of Gurevich and Shelah from 1986, it has been known that on finite structures both log- ics have the same expressive power. On infinite structures however, the question whether there is a formula inIFP not equivalent to anyLFP-formula was still open. In this paper, we settle the question
Fixed point structure of quenched, planar quantum electrodynamics
Love, S.T.
1986-07-01
Gauge theories exhibiting a hierarchy of fermion mass scales may contain a pseudo-Nambu-Boldstone boson of spontaneously broken scale invariance. The relation between scale and chiral symmetry breaking is studied analytically in quenched, planar quantum electrodynamics in four dimensions. The model possesses a novel nonperturbative ultraviolet fixed point governing its strong coupling phase which requires the mixing of four fermion operators. 12 refs.
Signatures of gravitational fixed points at the LHC
Daniel F. Litim; Tilman Plehn
2008-02-21
We study quantum-gravitational signatures at the Large Hadron Collider (LHC) in the context of theories with extra spatial dimensions and a low fundamental Planck scale in the TeV range. Implications of a gravitational fixed point at high energies are worked out using Wilson's renormalisation group. We find that relevant cross-sections involving virtual gravitons become finite. Based on gravitational lepton pair production we conclude that the LHC is sensitive to a fundamental Planck scale of up to 6 TeV.
Monotonic convergence of fixed-point algorithms for ICA.
Regalia, P A; Kofidis, E
2003-01-01
We re-examine a fixed-point algorithm proposed by Hyvarinen for independent component analysis, wherein local convergence is proved subject to an ideal signal model using a square invertible mixing matrix. Here, we derive step-size bounds which ensure monotonic convergence to a local extremum for any initial condition. Our analysis does not assume an ideal signal model but appeals rather to properties of the contrast function itself, and so applies even with noisy data and/or more sources than sensors. The results help alleviate the guesswork that often surrounds step-size selection when the observed signal does not fit an idealized model. PMID:18238073
Accuracy and Efficiency in Fixed-Point Neural ODE Solvers.
Hopkins, Michael; Furber, Steve
2015-10-01
Simulation of neural behavior on digital architectures often requires the solution of ordinary differential equations (ODEs) at each step of the simulation. For some neural models, this is a significant computational burden, so efficiency is important. Accuracy is also relevant because solutions can be sensitive to model parameterization and time step. These issues are emphasized on fixed-point processors like the ARM unit used in the SpiNNaker architecture. Using the Izhikevich neural model as an example, we explore some solution methods, showing how specific techniques can be used to find balanced solutions. We have investigated a number of important and related issues, such as introducing explicit solver reduction (ESR) for merging an explicit ODE solver and autonomous ODE into one algebraic formula, with benefits for both accuracy and speed; a simple, efficient mechanism for cancelling the cumulative lag in state variables caused by threshold crossing between time steps; an exact result for the membrane potential of the Izhikevich model with the other state variable held fixed. Parametric variations of the Izhikevich neuron show both similarities and differences in terms of algorithms and arithmetic types that perform well, making an overall best solution challenging to identify, but we show that particular cases can be improved significantly using the techniques described. Using a 1 ms simulation time step and 32-bit fixed-point arithmetic to promote real-time performance, one of the second-order Runge-Kutta methods looks to be the best compromise; Midpoint for speed or Trapezoid for accuracy. SpiNNaker offers an unusual combination of low energy use and real-time performance, so some compromises on accuracy might be expected. However, with a careful choice of approach, results comparable to those of general-purpose systems should be possible in many realistic cases. PMID:26313605
Surveying the three-dimensional fixed points of T duality
Ayon-Beato, Eloy [Centro de Estudios Cientificos (CECS), Casilla 1469, Valdivia (Chile); Departamento de Fisica, CINVESTAV-IPN, Apdo. Postal 14-740, 07000, Mexico D.F. (Mexico); Giribet, Gaston [Departamento de Fisica, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I (1428), Buenos Aires (Argentina)
2007-02-15
We explore the family of fixed points of T-duality transformations in three dimensions. For the simplest nontrivial self-duality conditions it is possible to show that, in addition to the spacelike isometry in which the T-duality transformation is performed, these backgrounds must be necessarily stationary. This allows us to prove that, for nontrivial string coupling, the low energy bosonic string backgrounds, which are additionally self-T-dual along an isometry direction generated by a constant norm Killing vector, are uniquely described by a two-parametric class, including only three nonsingular cases: the charged black string, the exact gravitational wave propagating along the extremal black string, and the flat space with a linear dilaton. Besides, for constant string coupling, the only self-T-dual lower energy string background under the same assumptions corresponds to the Coussaert-Henneaux spacetime. Thus, we identify minimum criteria that yield a classification of these quoted examples and only these. All these T-dual fixed points describe exact backgrounds of string theory.
24 CFR 50.16 - Decision points for policy actions.
Code of Federal Regulations, 2011 CFR
2011-04-01
...2011-04-01 false Decision points for policy actions. 50.16 Section 50.16 ...ENHANCEMENT OF ENVIRONMENTAL QUALITY General Policy: Decision Points § 50.16 Decision points for policy actions. Either an EA and FONSI or...
24 CFR 50.16 - Decision points for policy actions.
Code of Federal Regulations, 2010 CFR
2010-04-01
...2010-04-01 false Decision points for policy actions. 50.16 Section 50.16 ...ENHANCEMENT OF ENVIRONMENTAL QUALITY General Policy: Decision Points § 50.16 Decision points for policy actions. Either an EA and FONSI or...
24 CFR 50.16 - Decision points for policy actions.
Code of Federal Regulations, 2012 CFR
2012-04-01
...2012-04-01 false Decision points for policy actions. 50.16 Section 50.16 ...ENHANCEMENT OF ENVIRONMENTAL QUALITY General Policy: Decision Points § 50.16 Decision points for policy actions. Either an EA and FONSI or...
24 CFR 50.16 - Decision points for policy actions.
Code of Federal Regulations, 2013 CFR
2013-04-01
...2013-04-01 false Decision points for policy actions. 50.16 Section 50.16 ...ENHANCEMENT OF ENVIRONMENTAL QUALITY General Policy: Decision Points § 50.16 Decision points for policy actions. Either an EA and FONSI or...
24 CFR 50.16 - Decision points for policy actions.
Code of Federal Regulations, 2014 CFR
2014-04-01
...2014-04-01 false Decision points for policy actions. 50.16 Section 50.16 ...ENHANCEMENT OF ENVIRONMENTAL QUALITY General Policy: Decision Points § 50.16 Decision points for policy actions. Either an EA and FONSI or...
A Fixed-Point Iteration Method with Quadratic Convergence
Walker, Kevin P. [Engineering Science Software, Inc.; Sham, Sam [ORNL
2012-01-01
The fixed-point iteration algorithm is turned into a quadratically convergent scheme for a system of nonlinear equations. Most of the usual methods for obtaining the roots of a system of nonlinear equations rely on expanding the equation system about the roots in a Taylor series, and neglecting the higher order terms. Rearrangement of the resulting truncated system then results in the usual Newton-Raphson and Halley type approximations. In this paper the introduction of unit root functions avoids the direct expansion of the nonlinear system about the root, and relies, instead, on approximations which enable the unit root functions to considerably widen the radius of convergence of the iteration method. Methods for obtaining higher order rates of convergence and larger radii of convergence are discussed.
Fixed point of second virial coefficients in the glass transition
Jialin Wu
2007-01-16
Classical thermodynamic theory still holds true in subsystem that is a percolation connected by 8 orders of self-similar 2-body-3-body coupling clusters. The fixed point, $B_2^* \\equiv 3/8$, for the clusters of different size, existing in reduced second Virial coefficients has been proved by scaling theory in percolation field. It is shown that, if $B_2^* \\equiv 3/8$ is combined with $B_3^* \\equiv 5/8$, the potentials of 2-body-3-body coupling clusters, in critical local cluster growth phase transition, balance the kinetic energy in the glass transition. It is also proved that the glass transition corresponds to the regime in which the chemical potentials in all subsystems hold zero.
Unifying Bit-width Optimisation for Fixed-point and Floating-point Designs Altaf Abdul Gaffar1
Mencer, Oskar
Unifying Bit-width Optimisation for Fixed-point and Floating-point Designs Altaf Abdul Gaffar1- width of the various operands in the design. This sensitivity analysis enables us to explore and compare fixed-point and floating-point implementation for a particular design. As a result we can automate
Basins of attraction in quadratic dynamical systems with a Jordan fixed point Marco Abate
Roma Tor Vergata, UniversitÃ di
Basins of attraction in quadratic dynamical systems with a Jordan fixed point Marco Abate give su#cient conditions on the parameters for the existence of an open set attracted by the origin. Keywords: Discrete complex dynamics, parabolic fixed point, Jordan fixed point, basin of attraction. 0
New Insights from a Fixed Point Analysis of Single Cell IEEE 802.11 WLANs
Kumar, Anurag
1 New Insights from a Fixed Point Analysis of Single Cell IEEE 802.11 WLANs Anurag Kumar1, Eitan Altman2, Daniele Miorandi3 and Munish Goyal1 Abstract-- We study a fixed point formalisation of the well of the analysis. In this more general framework, the fixed point solution and performance measures resulting from
Fixed Point Analysis of Single Cell IEEE 802.11e WLANs: Uniqueness and Multistability
Kumar, Anurag
1 Fixed Point Analysis of Single Cell IEEE 802.11e WLANs: Uniqueness and Multistability Venkatesh Ramaiyan1 Anurag Kumar1 and Eitan Altman2 Abstract-- We consider the vector fixed point equations arisingFrame Space (AIFS) values. We consider balanced and unbalanced solutions of the fixed point equations arising
Fixed Point Analysis of the Saturation Throughput of IEEE 802.11 WLANs with Capture
Kumar, Anurag
1 Fixed Point Analysis of the Saturation Throughput of IEEE 802.11 WLANs with Capture Venkatesh capture, fading or frame error), using a fixed point framework developed in [7]. Here, we extend the work then obtain the fixed point equations for the infrastructure model. We show that these equations accurately
New Insights from a Fixed Point Analysis of Single Cell IEEE 802.11 WLANs
Kumar, Anurag
New Insights from a Fixed Point Analysis of Single Cell IEEE 802.11 WLANs Anurag Kumar1, Eitan Altman2, Daniele Miorandi2 and Munish Goyal1 Abstract-- We study a fixed point formalisation of the well. In this more general framework, the fixed point solution and performance measures resulting from it are studied
Clinical Evaluation of Proximal Contact Points in Fixed Prostheses.
Akhtar, Qayyum; Danyal, Sadia; Zareen, Shazia; Ahmed, Bilal; Maqsood, Muzamil; Azad, Azad Ali
2015-09-01
This cross-sectional study clinically assesses the tightness of proximal contact points of fixed dental prosthesis with natural teeth. Sixty nine (69) patients visiting the Department of Prosthodontics, Armed Forces Institute of Dentists (AFID), Rawalpindi, were included. The crowns, as a single unit or terminal abutment of bridge, prepared and fabricated at the same institute were included. Atotal of 142 Proximal Contact Points (PCPs) were assessed with the dental floss and categorized as acceptable, loose and tight. Among these, 83 (58.4%) were acceptable, 41 (28.8%) loose and 18 (12.6%) were tight. Out of 142 PCPs, 104 (73.2%) were Porcelain Fused to Metal (PFM) and 38 (26.7%), all metal. Out of 104 PFM crown/FPD PCPs 59 (56.7%) were acceptable, 32 (30.7%) were loose and 13 (12.5%) tight. Out of 38 all metal crown/FPD PCPs 24 (63%) acceptable, 9 (23%) were loose and 5 (13%) were tight. PCPs must be checked for acceptability before cementation. The PCPs of adjacent natural dentition in same patient may serve as guide for assessment. PMID:26374372
Standard map in magnetized relativistic systems: fixed points and regular acceleration
M. C. de Sousa; F. M. Steffens; R. Pakter; F. B. Rizzato
2010-07-30
We investigate the concept of a standard map for the interaction of relativistic particles and electrostatic waves of arbitrary amplitudes, under the action of external magnetic fields. The map is adequate for physical settings where waves and particles interact impulsively, and allows for a series of analytical result to be exactly obtained. Unlike the traditional form of the standard map, the present map is nonlinear in the wave amplitude and displays a series of peculiar properties. Among these properties we discuss the relation involving fixed points of the maps and accelerator regimes.
Some Extensions of Discrete Fixed Point Theorems and Their Applications to the Game Theory
NASA Astrophysics Data System (ADS)
Kawasaki, Hidefumi
2009-09-01
As is well-known in the game theory, fixed point theorems are useful to show the existence of Nash equilibrium. Since they are mathematical tools in continuous variables, it is expected that discrete fixed point theorems also useful to guarantee the existence of pure-strategy Nash equilibrium. In this talk, we review three types of discrete fixed point theorems, give some extensions, and apply them to non-cooperative games.
Jens Christian Claussen; Thorsten Mausbach; Alexander Piel; Heinz Georg Schuster
2006-09-20
Difference control schemes for controlling unstable fixed points become important if the exact position of the fixed point is unavailable or moving due to drifting parameters. We propose a memory difference control method for stabilization of a priori unknown unstable fixed points by introducing a memory term. If the amplitude of the control applied in the previous time step is added to the present control signal, fixed points with arbitrary Lyapunov numbers can be controlled. This method is also extended to compensate arbitrary time steps of measurement delay. We show that our method stabilizes orbits of the Chua circuit where ordinary difference control fails.
NASA Astrophysics Data System (ADS)
Wolber, L.; Fellmuth, B.
2011-01-01
The realization of the triple points of the cryogenic gases hydrogen, neon, oxygen, and argon as temperature fixed points at the highest level of accuracy requires consideration of the special properties of these fixed-point substances, as done in a general measurement protocol published elsewhere. The protocol is applied to the apparatus and methodology used for an international star intercomparison of sealed fixed-point cells. A generalized thermal model is developed to include the coexistence of different solid-liquid interfaces and various thermal resistances. This results in further components in the detailed uncertainty budget for the correction of the measuring power of the thermometer and for the extrapolation to the liquidus point. As a basis for an optimum fixed-point realization, especially an explanation is given why extremely long time periods may be necessary for the thermal recovery after pulses of the intermittent heating used for the calorimetric method.
Composition analysis of large samples with PGNAA using a fixed point iteration
NASA Astrophysics Data System (ADS)
Akkurt, Hatice
2002-09-01
The composition problem in large sample prompt gamma neutron activation analysis (PGNAA) is a nonlinear inverse problem. The basic form of the nonlinear inverse composition problem is presented. This problem is then formulated in a general way, as a fixed point problem, without addressing any specific application or sample type or linearization approach. This approach of formulating the problem as a fixed point problem suggested a natural fixed point iteration. The algorithm of the fixed point iteration solves the nonlinear composition problem using a combination of measured and computed data. The effectiveness of the fixed point iteration for composition analysis is demonstrated using purely numerical experiments. These numerical experiments showed that the fixed point iteration can be successfully applied to find the bulk composition of large samples, with excellent agreement between the estimated and true composition of the samples, in a few iterations, independent of the initial guess. In order to test the fixed point iteration using real experimental data, a series of large sample PGNAA measurements were performed at ANL-W. These experiments are described and the measured spectra for the samples are presented. Then, the fixed point iteration is applied for these real experiments to find the composition of the samples. In all of the cases, except borated polyethylene, the composition of the large samples are found in a few iterations with errors less than +/-1.3%. The effectiveness of the fixed point iteration is thus demonstrated with many proof-of-principle measurements. While testing the fixed point iteration algorithm, published values of the source spectrum and relative detector efficiencies are used. The sensitivity of the fixed point iteration to source spectrum is investigated and it is shown that the estimated composition results are not very sensitive to the change in the source spectrum. The reason behind the slow convergence for the borated polyethylene sample is also investigated and it is shown that the convergence is slow because of the presence of clean polyethylene in the experiment.
Nonanticommutative U(1) SYM theories: Renormalization, fixed points and infrared stability
Marco S. Bianchi; Silvia Penati; Alberto Romagnoni; Massimo Siani
2009-04-21
Renormalizable nonanticommutative SYM theories with chiral matter in the adjoint representation of the gauge group have been recently constructed in [arXiv:0901.3094]. In the present paper we focus on the U*(1) case with matter interacting through a cubic superpotential. For a single flavor, in a superspace setup and manifest background covariant approach we perform the complete one-loop renormalization and compute the beta-functions for all couplings appearing in the action. We then generalize the calculation to the case of SU(3) flavor matter with a cubic superpotential viewed as a nontrivial NAC generalization of the ordinary abelian N=4 SYM and its marginal deformations. We find that, as in the ordinary commutative case, the NAC N=4 theory is one-loop finite. We provide general arguments in support of all-loop finiteness. Instead, deforming the superpotential by marginal operators gives rise to beta-functions which are in general non-vanishing. We study the spectrum of fixed points and the RG flows. We find that nonanticommutativity always makes the fixed points unstable.
Teaching Hardware Design of Fixed-Point Digital Signal Processing Systems
David V. Anderson; Tyson S. Hall
Signal processing theory and practice are enabling and driving forces behind multimedia de- vices, communications systems, and even such diverse fields as automotive and medical sys- tems. Over 90% of the signal processing systems on the market used fixed-point arithmetic because of the cost, power, and area savings that fixed-point systems provide. However, most colleges and universities do not teach
New fixed points of the renormalisation group for two-body scattering
M. C. Birse; E. Epelbaum; J. Gegelia
2015-10-08
We outline a separable matrix ansatz for the potentials in effective field theories of nonrelativistic two-body systems with short-range interactions. We use this ansatz to construct new fixed points of the renormalisation-group equation for these potentials. New fixed points indicate a much richer structure than previously recognized in the RG flows of simple short-range potentials.
Geometric structures associated to triangulations as fixed point sets of involutions
Falbel, Elisha
Geometric structures associated to triangulations as fixed point sets of involutions E. FalbelÂmail: falbelmath.jussieu.fr March 31, 2009 Abstract We establish that hyperbolic structures and spherical CR structures on a three dimensional manifold are contained in fixed point sets of a larger class of structures
Geometric structures associated to triangulations as fixed point sets of involutions
Falbel, Elisha
Geometric structures associated to triangulations as fixed point sets of involutions E. Falbel-mail: falbelmath.jussieu.fr November 14, 2006 Abstract We establish that hyperbolic structures and spherical CR structures on a three dimensional manifold are contained in fixed point sets of a larger class of structures
FIXED POINT THEOREMS FOR NEW GENERALIZED HYBRID MAPPINGS IN HILBERT SPACES AND APPLICATIONS
Wong, Ngai-Ching
FIXED POINT THEOREMS FOR NEW GENERALIZED HYBRID MAPPINGS IN HILBERT SPACES AND APPLICATIONS WATARU of nonlinear mappings in a Hilbert space which contains the classes of nonexpansive mappings, non- spreading of such mappings. Using these results, we prove well-known and new fixed point theorems in a Hilbert space. We
FIXED POINT THEOREMS FOR GENERAL CONTRACTIVE MAPPINGS WITH W-DISTANCES IN METRIC SPACES
Wong, Ngai-Ching
FIXED POINT THEOREMS FOR GENERAL CONTRACTIVE MAPPINGS WITH W-DISTANCES IN METRIC SPACES WATARU-distances on a metric space, we first prove a generalized fixed point theorem for mappings without con- tinuity] and the nonconvex min- imization theorem according to Takahashi [15]. Let (X, d) be a metric space. A mapping T : X
A Fixed Point Charge Model for Water Optimized to the Vapor-Liquid Coexistence Properties
A Fixed Point Charge Model for Water Optimized to the Vapor-Liquid Coexistence Properties Jeffrey R@ipst.umd.edu #12;1 Abstract A new fixed-point charge potential model for water has been developed, targeting the accurate prediction of the vapor-liquid coexistence properties over a broad temperature range. The model
EA Models and Population Fixed-Points Versus Mutation Rates for Functions of Unitation
Wright, Alden H.
EA Models and Population Fixed-Points Versus Mutation Rates for Functions of Unitation J Neal theory of evolutionary algorithms, infinite population models, unitation functions, fixed points, genetic algorithms. 1. INTRODUCTION The Vose infinite population model [1] of simple genetic algorithms is a dynamic
Multiple positive fixed points of nonlinear operators on ordered Banach spaces
R. W. Leggett; L. R. Williams
1979-01-01
The existence of multiple positive fixed points of completely continuous nonlinear operators defined on the cone of an ordered Banach space is considered. The main results give sufficient conditions for such an operator to have two, and in some cases three, positive fixed points. (RWR)
Three positive fixed points of nonlinear operators on ordered banach spaces
A. C. Peterson
2001-01-01
We generalize the fixed-point theorem of Leggett-Williams, which is a theorem giving conditions that imply the existence of three fixed points of an operator defined on a cone in a Banach space. We then show how to apply our theorem to prove the existence of three positive solutions to a second-order discrete boundary value problem.
A Characterization of the Set of Fixed Points of the Quicksort Transformation
Janson, Svante
The limiting distribution ~ of the normalized number of key comparisons requ* *ired by the Quicksort sorting A Characterization of the Set of Fixed Points of the Quicksort algorithm is known to be the unique fixed point of a certain * *distributional transformation T
Convergence properties of fixed-point search with general but equal phase shifts for any iterations
D. Li; X. Li; H. Huang; X. Li
2008-07-16
Grover presented the fixed-point search by replacing the selective inversions by selective phase shifts of $\\pi /3$. In this paper, we investigate the convergence behavior of the fixed-point search algorithm with general but equal phase shifts for any iterations.
Triple point of e-deuterium as an accurate thermometric fixed point
Pavese, F.; McConville, G.T.
1986-01-01
The triple point of deuterium (18.7/sup 0/K) is the only possibility for excluding vapor pressure measurements in the definition of a temperature scale based on fixed points between 13.81 and 24.562/sup 0/K. This paper reports an investigation made at the Istituto di Metrologia and Mound Laboratory, using extremely pure deuterium directly sealed at the production plant into small metal cells. The large contamination by HD of commercially available gas, that cannot be accounted and corrected for due to its increase in handling, was found to be very stable with time after sealing in IMGC cells. HD contamination can be limited to less than 100 ppM in Monsanto cells, both with n-D/sub 2/ and e-D/sub 2/, when filled directly from the thermal diffusion column and sealed at the factory. e-D/sub 2/ requires a special deuterated catalyst. The triple point temperature of e-D/sub 2/ has been determined to be: T(NPL-IPTS-68) = 18.7011 +- 0.002/sup 0/K. 20 refs., 3 figs., 2 tabs.
Fixed Point of a TCP/RENO DiffServ Network with a Single Congested Link
Massachusetts at Amherst, University of
-point even at an exact- provisioned network. Since the green set-point is above the red set-point, soFixed Point of a TCP/RENO DiffServ Network with a Single Congested Link Y. Chait and C.V. Hollot DiffServ papers. 1 Preliminaries The DiffServ network under consideration run TCP RENO, uses a multi
A New Co-C Eutectic Fixed-Point Cell for Thermocouple Calibration at
NASA Astrophysics Data System (ADS)
Failleau, G.; Deuzé, T.; Jouin, D.; Mokdad, S.; Briaudeau, S.; Sadli, M.
2014-07-01
The eutectic Co-C is a promising system to serve as a thermometric fixed point beyond the freezing point of copper (). Some national metrology institutes have developed, characterized, and compared their Co-C fixed-point cells based on conventional designs. Indeed, the fixed-point cells constructed are directly inspired by the technologies applied to the fixed points of the ITS-90 to the lower levels of temperature. By studying the eutectic metal-carbon systems, is appears that the high temperatures of implementation give a set of difficulties, such as the strong mechanical stresses on the graphite crucibles, due to the important thermal expansion of the eutectic alloys during their phase transitions. If these devices are suitable with research activities to serve like primary standards, it is not envisaged to propose them for a direct application to the calibration activities for the industry. As regards the limited robustness of the conventional fixed-point cells constructed, an intensive use of these device would not be reasonable, in term of cost for example. In this paper, a new Co-C fixed-point design is introduced. This low cost device has been developed specifically for intensive use in thermocouple calibration activities, with the aim of achieving the lowest level of uncertainties as is practicable. Thus, in this paper, the metrological characterization of this device is also presented, and a direct comparison to a primary Co-C fixed-point cell previously constructed is discussed.
High-temperature fixed points for pre-launch calibration of earth observing sensors
NASA Astrophysics Data System (ADS)
Yamada, Yoshiro; Ishii, Juntaro
2011-10-01
High-temperature fixed points of metal-carbon systems, currently the target of a project in the international thermometry standards community, is also of high interest for pre-launch radiometric calibration of hyperspectral earth observing sensor in the blue wavelengths, where the conventional copper fixed point fails to supply sufficient radiance. For such a calibration, a fixed-point possibly around 2000 K is desired. One requirement for application of the high-temperature blackbody fixed-point cell to remote sensor calibration is to increase the radiating source aperture diameter to a size large enough to target with a radiance comparator based on a grating monochromator. In this presentation, a fixed-point cell of Co-C eutectic (1597 K) for remote sensor calibration application is described. An enlarged 7-mm aperture design is employed for the fixed-point cell while at the same time retaining the outer dimension to fit in existing fixed-point furnaces. The observed plateaux showed temperature and repeatability comparable to conventional 3-mm aperture cells, while cavity breakages indicates the need for improved robustness in the crucible design. Extension of the technique to Pt-C eutectic (2011 K) or Cr3C2-C peritectic (2100 K) systems, and subsequent application to calibration of the HISUI sensor is envisaged.
NASA Astrophysics Data System (ADS)
Dittmore, Andrew; Trail, Collin; Olsen, Thomas; Wiener, Richard J.
2003-11-01
We have previously demonstrated the experimental control of chaos in a Modified Taylor-Couette system with hourglass geometry( Richard J. Wiener et al), Phys. Rev. Lett. 83, 2340 (1999).. Identifying fixed points susceptible to algorithms for the control of chaos is key. We seek to learn about this process in the accessible numerical model of the damped, driven pendulum. Following Baker(Gregory L. Baker, Am. J. Phys. 63), 832 (1995)., we seek points susceptible to the OGY(E. Ott, C. Grebogi, and J. A. Yorke, Phys. Rev. Lett. 64), 1196 (1990). algorithm. We automate the search for fixed points that are candidates for control. We present comparisons of the space of candidate fixed points with the bifurcation diagrams and Poincare sections of the system. We demonstrate control at fixed points which do not appear on the attractor. We also show that the control algorithm may be employed to shift the system between non-communicating branches of the attractor.
NASA Astrophysics Data System (ADS)
Itou, Etsuko
2013-08-01
We report the nonperturbative behavior of the twisted Polyakov loop (TPL) coupling constant for the SU(3) gauge theories defined by the ratio of Polyakov loop correlators in finite volume with twisted boundary condition. We reveal the vacuum structures and the phase structure for the lattice gauge theory with the twisted boundary condition. Carrying out the numerical simulations, we determine the nonperturbative running coupling constant in this renormalization scheme for the quenched QCD and N_f=12 SU(3) gauge theories. First, we study the quenched QCD theory using the plaquette gauge action. The TPL coupling constant has a fake fixed point in the confinement phase. We discuss this fake fixed point of the TPL scheme and obtain the nonperturbative running coupling constant in the deconfinement phase, where the magnitude of the Polyakov loop shows the nonzero values. We also investigate the system coupled to fundamental fermions. Since we use the naive staggered fermion with the twisted boundary condition in our simulation, only multiples of 12 are allowed for the number of flavors. According to the perturbative two-loop analysis, the N_f=12 SU(3) gauge theory might have a conformal fixed point in the infrared region. However, recent lattice studies show controversial results for the existence of the fixed point. We point out possible problems in previous work, and present our careful study. Finally, we find the infrared fixed point (IRFP) and discuss the robustness of the nontrivial IRFP of a many-flavor system under the change of the analysis method. Some preliminary results were reported in the proceedings [E. Bilgici et al., PoS(Lattice 2009), 063 (2009); Itou et al., PoS(Lattice 2010), 054 (2010)] and the letter paper [T. Aoyama et al., arXiv:1109.5806 [hep-lat
Tino, Peter
Attractive Periodic Sets in Discrete Time Recurrent Networks (with Emphasis on Fixed Point), new attractive #12;xed points are created through the saddle-node bifurcation. Finally, for an N-neuron recurrent network, we give lower bounds on the rate of convergence of attractive periodic points towards
Melting Temperature of High-Temperature Fixed Points for Thermocouple Calibrations
NASA Astrophysics Data System (ADS)
Pearce, J. V.; Montag, V.; Lowe, D.; Dong, W.
2011-01-01
Thermocouples can be calibrated at pure metal ingot-based fixed points at temperatures up to the freezing point of copper (1084.62 °C). For Pt/Pd thermocouples, the deviation from the accepted reference function very often takes an approximately linear form up to the copper fixed point. The calibration of Pt/Pd thermocouples may therefore be more amenable to extrapolation than that of Pt/Pt-Rh thermocouples. Here, the melting temperatures of a Co-C and a Pd-C eutectic fixed point are determined by extrapolating the deviation functions of several Pt/Pd thermocouples, after the fashion of Edler et al. The results are compared with the melting temperatures measured using non-contact radiation thermometry. The expanded uncertainty ( k = 2) of the melting temperatures determined by extrapolation of the Pt/Pd thermocouple calibrations is ±0.32 °C for the Co-C fixed point, and ±0.49 °C for the Pd-C fixed point. For both fixed points, these uncertainties are comparable to those of non-contact radiation thermometry measurements. While a number of assumptions are made in performing the extrapolation of the calibrations, the method does appear to offer a useful complement to non-contact radiation thermometry measurements.
Examples involving shrinking conditions of fixed point theorems
Sharp, Douglas Andrew
1970-01-01
EXAMPLES INVOI. VING SHRINKING CONDITIONS OP PIXED YOINT 'r. 'EOREirS A Thesis DOUGLAS ANDRE':i SE"A & Submitted tn the Graduate ColleSe of Tera. AGIi Umiversity ir ps. -. tial fu'j illmeut of' the requiremcrrt for the "eS;cc of MASTER OT' S...: airm'n ~ "=, , ~, i t te. g ~H(l - D~g::"' . t) ~I"ice . x December lg(O ABHTHi Examples Invcl ~in- Zhcin'? n Boa" tion" of Pixed Point Theorems. (December 1/70) Douglas inc ew Bheop, B. l. , Texas ~". I Uni r rsitg j Directedj. by: Dr. Jac...
Existence of Tripled Fixed Points for a Class of Condensing Operators in Banach Spaces
Karakaya, Vatan; Bouzara, Nour El Houda; Do?an, Kadri; Atalan, Yunus
2014-01-01
We give some results concerning the existence of tripled fixed points for a class of condensing operators in Banach spaces. Further, as an application, we study the existence of solutions for a general system of nonlinear integral equations. PMID:25866836
Latif, Abdul
2014-01-01
We extend the notion of generalized weakly contraction mappings due to Choudhury et al. (2011) to generalized ?-?-weakly contraction mappings. We show with examples that our new class of mappings is a real generalization of several known classes of mappings. We also establish fixed point results for such mappings in metric spaces. Applying our new results, we obtain fixed point results on ordinary metric spaces, metric spaces endowed with an arbitrary binary relation, and metric spaces endowed with graph. PMID:24895662
High-temperature metal-carbon eutectic fixed-point cells with improved robustness
Y. Yamada; P. Bloembergen
2004-01-01
A novel metal-carbon eutectic fixed-point cell taking advantage of a hyper-eutectic porous structure to improve its robustness is proposed. This structure maintains its porous form and its shape even after melting. Investigation has revealed that the cell can withstand repeated rapid heating and cooling without breakage, and repeatability of the melting temperature comparable to conventional metal-carbon eutectic fixed point cells
On Fixed-point theorems in Intuitionistic Fuzzy metric Space I
T. K. Samanta; Sumit Mohinta
2011-03-15
In this paper, first we have established two sets of sufficient conditions for a TS-IF contractive mapping to have unique fixed point in a intuitionistic fuzzy metric space. Then we have defined \\,$(\\,\\epsilon \\,,\\, \\lambda\\,)$\\, IF-uniformly locally contractive mapping and \\,$\\eta\\,-$\\,chainable space, where it has been proved that the \\,$(\\,\\epsilon \\,,\\, \\lambda\\,)$\\, IF-uniformly locally contractive mapping possesses a fixed point
Evaluation of the Pd-C eutectic fixed point and the Pt/Pd thermocouple
NASA Astrophysics Data System (ADS)
Pearce, J. V.; Ogura, H.; Izuchi, M.; Machin, G.
2009-10-01
A Pd-C eutectic fixed point cell (1492 °C) was constructed to investigate its utility for thermocouple calibration. The primary aim of the study was to evaluate the long-term stability, immersion characteristics (influence of heat conduction along the thermocouple stem) and robustness of a Pd-C fixed point using a Pt/Pd thermocouple, especially constructed for this purpose. The performance of both devices at this relatively high temperature could therefore be tested. The melting and freezing plateaux at the Pd-C eutectic point were measured using the Pt/Pd thermocouple. The total exposure to the Pd-C melting temperature was about 850 h for the fixed point cell and 550 h for the thermocouple. The standard deviations of the melting and freezing points were 1.03 µV (0.041 °C) and 0.77 µV (0.031 °C) respectively. The emfs of the thermocouple at the melting point were observed to drift by about 0.1 °C. The immersion measurements show that for the current cell design, the measuring junction should be at most 30 mm from the bottom of the thermowell to be properly immersed. The long-term performance and robustness of the fixed point indicate a promising future for its use as a fixed point for calibration of noble metal thermocouples.
Analysis of fixed point FFT for Fourier domain optical coherence tomography systems.
Ali, Murtaza; Parlapalli, Renuka; Magee, David P; Dasgupta, Udayan
2009-01-01
Optical coherence tomography (OCT) is a new imaging modality gaining popularity in the medical community. Its application includes ophthalmology, gastroenterology, dermatology etc. As the use of OCT increases, the need for portable, low power devices also increases. Digital signal processors (DSP) are well suited to meet the signal processing requirements of such a system. These processors usually operate on fixed precision. This paper analyzes the issues that a system implementer faces implementing signal processing algorithms on fixed point processor. Specifically, we show the effect of different fixed point precisions in the implementation of FFT on the sensitivity of Fourier domain OCT systems. PMID:19965018
Extending the Nonlinear-Beam-Dynamics Concept of 1D Fixed Points to 2D Fixed Lines.
Franchetti, G; Schmidt, F
2015-06-12
The origin of nonlinear dynamics traces back to the study of the dynamics of planets with the seminal work of Poincaré at the end of the nineteenth century: Les Méthodes Nouvelles de la Mécanique Céleste, Vols. 1-3 (Gauthier Villars, Paris, 1899). In his work he introduced a methodology fruitful for investigating the dynamical properties of complex systems, which led to the so-called "Poincaré surface of section," which allows one to capture the global dynamical properties of a system, characterized by fixed points and separatrices with respect to regular and chaotic motion. For two-dimensional phase space (one degree of freedom) this approach has been extremely useful and applied to particle accelerators for controlling their beam dynamics as of the second half of the twentieth century. We describe here an extension of the concept of 1D fixed points to fixed lines in two dimensions. These structures become the fundamental entities for characterizing the nonlinear motion in the four-dimensional phase space (two degrees of freedom). PMID:26196806
Kumar, Anurag
Fixed Point Analysis of Single Cell IEEE 802.11e WLANs: Uniqueness, Multistability and Throughput Differentiation Venkatesh Ramaiyan1, Anurag Kumar1, Eitan Altman2 Abstract-- We consider the vector fixed point- bitration InterFrame Space (AIFS) values. We consider balanced and unbalanced solutions of the fixed point
Calibration of Radiation Thermometry Fixed Points Using Au/Pt Thermocouples
NASA Astrophysics Data System (ADS)
Jahan, F.; Ballico, M. J.
2011-01-01
At NMIA, radiation thermometers are calibrated by comparison with a number of reference radiation thermometers which are themselves calibrated using fixed-point cells on the ITS-90 temperature scale (In, Sn, Zn, Al, Ag, and Au). The suitability of NMIA fixed-point cells used for standard platinum resistance thermometers (SPRTs) is evaluated by the comparison of ensembles of cells at each fixed point, and by participation in the international BIPM Key-Comparisons K3 and K4. However, the NMIA fixed-point cells used for radiation thermometry are typically much smaller (only 110 mm in length) and the thermowell length immersed in the metal much shorter (85 mm) than those used for SPRTs. Further, the insulation at the front of the crucible needs to accommodate the F/10 viewing cone of the radiation thermometers, so significant temperature gradients exist near the top of the crucible. As a consequence, the conduction errors obtained using SPRTs are too large to be of practical use. A convenient methodology based on the use of a Au/Pt thermocouple, together with a protective tube assembly to reduce conduction errors, has been developed. This allows the convenient measurement of the phase transition temperature traceable, at the 30 mK level, to the fixed-point cells used at NMIA to realize and maintain the ITS-90 scale. As the measurements are made in situ, the temperature environment, and hence the geometry and formation of the liquid-solid interface during melting and freezing, are similar to that occurring when used with radiation thermometers. Results are presented for ITS-90 fixed points up to Ag, establishing formal traceability of radiation thermometry fixed-point cells to NMIA's primary ITS-90 cells.
A quantitative version of Kirk's fixed point theorem for asymptotic contractions
Gerhardy, Philipp
Introduction In [3], W.A. Kirk proved a fixedÂpoint theorem for soÂcalled asymptotic conÂ tractions on complete contractions as follows: Definition 1 (Kirk[3]) A function f : X # X on a metric space (X, d) is called point theorem proved by Kirk, we derive the following alternative definition of asymptotic contractions
FAST, ACCURATE STATIC ANALYSIS FOR FIXED-POINT FINITE-PRECISION EFFECTS IN DSP DESIGNS
Chen, Tsuhan
FAST, ACCURATE STATIC ANALYSIS FOR FIXED-POINT FINITE-PRECISION EFFECTS IN DSP DESIGNS Claire F is the bane of DSP hardware. DSP designs are routinely prototypedin high-precision float- ing point for ease- consuming task. We describe a new static analysis tech- nique that can accurately analyze finite
Hybrid Model of Fixed and Floating Point Numbers in Secure Multiparty Computations
International Association for Cryptologic Research (IACR)
to be applied. There exist numerous well-established statistical and data mining methods for data analysis. The basic idea is to consider the significand of the floating point number as a fixed point number Introduction Our contemporary society is growing more and more dependent on high-speed, high-volume data access
Fixed-Orientation Equilateral Triangle Matching of Point Sets Jasine Babu
Smid, Michiel
Fixed-Orientation Equilateral Triangle Matching of Point Sets Jasine Babu Department of Computer Science and Automation, Indian Institute of Science, Bangalore, India. Ahmad Biniaz, Anil Maheshwari, Michiel Smid School of Computer Science, Carleton University, Ottawa, Canada Abstract Given a point set P
Intercomparison of Copper Fixed-Point Cells by Using Pt/Pd Thermocouples
NASA Astrophysics Data System (ADS)
Edler, F.; Anagnostou, M.; Bojkovski, J.; Gaita, S.; García, C.; Grudniewicz, E.; Helgesen, F.; Ivarsson, J.; Pauza, A.; Rosenkranz, P.; Smid, M.; Weckström, T.; Zvizdic, D.
2008-02-01
The objective of the EUROMET Project No. 844 in the field of thermometry was the intercomparison of the freezing temperatures of the copper fixed-point cells ( t 90 = 1084.62°C) of the participating laboratories by using Pt/Pd thermocouples. For most of the 13 participating laboratories, agreement of the freezing temperatures of the different copper fixed points within ±0.06 K was found. Furthermore, the results of the intercomparison show that Pt/Pd thermocouples are suitable for use as transfer standards for the dissemination of temperatures and to approximate the ITS-90, at least up to the freezing point of copper.
NASA Astrophysics Data System (ADS)
Edler, F.; Baratto, A. C.
2006-12-01
Three nickel-carbon (Ni-C) and three iron-carbon (Fe-C) eutectic fixed points cells of a new design, meeting the requirements for reliable applications and being suitable for the calibration of thermocouples, were constructed at PTB and Inmetro. Their melting temperatures were compared by using the high-temperature furnace of PTB (HTF-R) and two platinum/palladium (Pt/Pd) thermocouples. The measured emfs of the Ni-C eutectic fixed point cells at the inflection points of the melting curves agree within a temperature equivalent of about 0.29 °C, compared with an agreement of about 0.09 °C found for the Fe-C cells. Additional comparison measurements of two Fe-C eutectic fixed point cells in a second high-temperature furnace (HTF-M, Inmetro) demonstrate the applicability of the Fe-C eutectic cells as transfer standards for the dissemination of temperatures.
Dark energy as a fixed point of the Einstein Yang-Mills Higgs Equations
Rinaldi, Massimiliano
2015-01-01
We study the Einstein Yang-Mills Higgs equations in the $SO(3)$ representation on a isotropic and homogeneous flat Universe, in the presence of radiation and matter fluids. We map the equations of motion into a closed dynamical system of first-order differential equations and we find the equilibrium points. We show that there is only one stable fixed point that corresponds to an accelerated expanding Universe in the future. In the past, instead, there is an unstable fixed point that implies a stiff-matter domination. In between, we find three other unstable fixed points, corresponding, in chronological order, to radiation domination, to matter domination, and, finally, to a transition from decelerated expansion to accelerated expansion. We solve the system numerically and we confirm that there are smooth trajectories that correctly describe the evolution of the Universe, from a remote past dominated by radiation to a remote future dominated by dark energy, passing through a matter-dominated phase.
The fate of the Wilson-Fisher fixed point in non-commutative ?^4
Badis Ydri; Adel Bouchareb
2012-11-06
In this article we study non-commutative vector sigma model with the most general \\phi^4 interaction on Moyal-Weyl spaces. We compute the 2- and 4-point functions to all orders in the large N limit and then apply the approximate Wilson renormalization group recursion formula to study the renormalized coupling constants of the theory. The non-commutative Wilson-Fisher fixed point interpolates between the commutative Wilson-Fisher fixed point of the Ising universality class which is found to lie at zero value of the critical coupling constant a_* of the zero dimensional reduction of the theory, and a novel strongly interacting fixed point which lies at infinite value of a_* corresponding to maximal non-commutativity beyond which the two-sheeted structure of a_* as a function of the dilation parameter disappears.
Listak, J.M.; Goodman, G.V.R.; Jankowski, R.A.
1999-07-01
Respirable dust studies were conducted at several underground coal mining operations to evaluate and compare the dust measurements of fixed-point machine-mounted samples on a continuous miner and personal samples of the remote miner operator. Fixed-point sampling was conducted at the right rear corner of the continuous miner which corresponded to the traditional location of the operator's cab. Although it has been documented that higher concentrations of dust are present at the machine-mounted position, this work sought to determine whether a relationship exists between the concentrations at the fixed-point position and the dust levels experienced at the remote operator position and whether this relationship could be applied on an industry-wide basis. To achieve this objective, gravimetric samplers were used to collect respirable dust data on continuous miner sections. These samplers were placed at a fixed position at the cab location of the continuous mining machine and on or near the remote miner operator during the 1 shift/day sampling periods. Dust sampling took place at mines with a variety of geographic locations and in-mine conditions. The dust concentration data collected at each site and for each sampling period were reduced to ratios of fixed-point to operator concentration. The ratios were calculated to determine similarities, differences, and/or variability at the two positions. The data show that dust concentrations at the remote operator position were always lower than dust concentrations measured at the fixed-point continuous miner location. However, the ratios of fixed-point to remote operator dust levels showed little consistency from shift to shift or from operation to operation. The fact that these ratios are so variable may introduce some uncertainty into attempting to correlate dust exposures of the remote operator to dust levels measured on the continuous mining machine.
Multi-Mini-Eutectic Fixed-Point Cell for Type C Thermocouple Self-Calibration
NASA Astrophysics Data System (ADS)
Ongrai, O.; Pearce, J. V.; Machin, G.; Norranim, U.
2015-03-01
Thermocouples are generally calibrated using a series of standard fixed-point cells. However, thermocouples in use, particularly base metal and refractory thermocouples, exhibit significant calibration drift due to factors such as inhomogeneity growth. It is not possible to reliably determine the magnitude of this drift by removing the thermocouple for recalibration and instead, must be quantified by some form of in situ calibration. Here, a multi-mini-cell for the use with a metal sheathed W-Re thermocouple (Type C) was developed. The cell contains two layers of different eutectic materials in the same crucible, one in each compartment, separated by a thin graphite disk. The cobalt-carbon and iron-carbon eutectic materials were selected to prove the concept. In addition, thermal modeling was performed to predict the performance of this design of this multi-fixed point. A prototype multi-mini-fixed-point cell was constructed and tested, and results are reported. The overall performance, despite only very small amounts of each fixed-point material being used, is that the repeatability of the W-Re thermocouple (melt-to-melt) was found to be 1.8 or for the Fe-C and 1.5 or for the Co-C . The lack of drift in the thermocouple enabled the repeatability and stability of the principle of multi-mini-fixed points for self-calibration to be demonstrated.
One-parameter semigroups of analytic functions, fixed points and the Koenigs function
NASA Astrophysics Data System (ADS)
Goryainov, Victor V.; Kudryavtseva, Olga S.
2011-07-01
Analogues of the Berkson-Porta formula for the infinitesimal generator of a one-parameter semigroup of holomorphic maps of the unit disc into itself are obtained in the case when, along with a Denjoy-Wolff point, there also exist other fixed points. With each one-parameter semigroup a so-called Koenigs function is associated, which is a solution, common for all elements of the one-parameter semigroup, of a certain functional equation (Schröder's equation in the case of an interior Denjoy-Wolff point and Abel's equation in the case of a boundary Denjoy-Wolff point). A parametric representation for classes of Koenigs functions that takes account of the Denjoy-Wolff point and other fixed points of the maps in the one-parameter semigroup is presented. Bibliography: 19 titles.
One-parameter semigroups of analytic functions, fixed points and the Koenigs function
Goryainov, Victor V; Kudryavtseva, Olga S
2011-07-31
Analogues of the Berkson-Porta formula for the infinitesimal generator of a one-parameter semigroup of holomorphic maps of the unit disc into itself are obtained in the case when, along with a Denjoy-Wolff point, there also exist other fixed points. With each one-parameter semigroup a so-called Koenigs function is associated, which is a solution, common for all elements of the one-parameter semigroup, of a certain functional equation (Schroeder's equation in the case of an interior Denjoy-Wolff point and Abel's equation in the case of a boundary Denjoy-Wolff point). A parametric representation for classes of Koenigs functions that takes account of the Denjoy-Wolff point and other fixed points of the maps in the one-parameter semigroup is presented. Bibliography: 19 titles.
Are judgments for action verbs and point-light human actions equivalent?
Bidet-Ildei, Christel; Toussaint, Lucette
2015-02-01
The aim of the present study was to examine whether the ability to judge action words and the ability to judge human actions share common mechanisms. With this purpose in mind, we proposed both a lexical and an action decision task to twenty-four healthy participants. For both tasks, the participants had to judge whether the stimulus that was presented (a letter string or a point-light sequence) was valid or not (i.e. a word vs. a pseudo-word, an action vs. a pseudo-action). The data analysis showed that the action decision task has common characteristics with the lexical decision task. As for verbal material, judgements of pseudo-actions were slower than judgements for actions. Moreover, we demonstrated that the ability to judge an action verb was positively correlated with the ability to judge a point-light human action, whereas no significant correlation appeared between nouns and point-light judgements abilities. This dissociation supports the argument that the judgement of action words and the judgement of human actions share a common but specific basis through the involvement of motor representations. PMID:25238900
On the Expressive Power of Monadic Least Fixed Point Logic (Full Version)
Nicole Schweikardt
Monadic least fixed point logic MLFP is a natural logic whose expres- siveness lies between that of first-order logic FO and monadic second-order logic MSO. In this paper we take a closer look at the expressive power of MLFP. Our results are 1. MLFP can describe graph properties beyond any fixed level of the monadic second-order quantifier alternation hierarchy.
Reference in Action: Links between Pointing and Language
ERIC Educational Resources Information Center
Cooperrider, Kensy Andrew
2011-01-01
When referring to things in the world, speakers produce utterances that are composites of speech and action. Pointing gestures are a pervasive part of such composite utterances, but many questions remain about exactly how pointing is integrated with speech. In this dissertation I present three strands of research that investigate relations of…
Recent direct measurement of the Top quark mass and quasi-infrared fixed point
Biswajoy Brahmachari
1997-06-24
We note that the recent direct measurement of the top quark mass at $173.3 \\pm 5.6 (stat) \\pm 6.2 (syst)$ by D0 collaboration severely constrains the theoretically attractive infra-red fixed point scenario of the top quark Yukawa coupling in supersymmetric GUTs. For one-step unified models the above mentioned measurement bounds the arbitrary but experimentally determinable parameter $\\tan \\beta$ to the range $1.3 \\le \\tan \\beta \\le 2.1$. Further crunch on the top quark mass may determine $\\tan \\beta$ even more accurately within the fixed point scenario. On the other hand an experimental value of $\\tan \\beta > 2.1$ will rule out the fixed point scenario bounding $h^2_t(M_X)/4 \\pi$ to 0.022 from above.
Fe-C eutectic fixed-point cells for contact thermometry: an investigation and comparison
NASA Astrophysics Data System (ADS)
Elliott, C. J.; Pearce, J. V.; Failleau, G.; Deuzé, T.; Briaudeau, S.; Sadli, M.; Machin, G.
2012-02-01
Five iron-carbon (Fe-C) eutectic fixed-point cells have been constructed between NPL and LNE-Cnam to investigate the robustness and to measure the agreement of their melting temperatures. Each cell was constructed with a different selection of materials sourced by NPL and LNE-Cnam. The measured emfs at the Fe-C fixed-point temperature (~1153 °C), compared between cells, agree within around 1.98 µV (~90 mK), where the most important contribution to the uncertainty of each measurement is the inhomogeneity associated with the measuring Pt/Pd thermocouple. This demonstrates that these cells are suitable for use as secondary fixed-point cells in contact thermometry but the robustness of the presented cells is not found to be sufficient for maintaining their integrity during repeated cycling procedures.
Finding Non-Zero Stable Fixed Points of the Weighted Kuramoto model is NP-hard
Richard Taylor
2015-02-24
The Kuramoto model when considered over the full space of phase angles [$0,2\\pi$) can have multiple stable fixed points which form basins of attraction in the solution space. In this paper we illustrate the fundamentally complex relationship between the network topology and the solution space by showing that determining the possibility of multiple stable fixed points from the network topology is NP-hard for the weighted Kuramoto Model. In the case of the unweighted model this problem is shown to be at least as difficult as a number partition problem, which we conjecture to be NP-hard. We conclude that it is unlikely that stable fixed points of the Kuramoto model can be characterized in terms of easily computable network invariants.
Fixed-point theorems for families of weakly non-expansive maps
NASA Astrophysics Data System (ADS)
Mai, Jie-Hua; Liu, Xin-He
2007-10-01
In this paper, we present some fixed-point theorems for families of weakly non-expansive maps under some relatively weaker and more general conditions. Our results generalize and improve several results due to Jungck [G. Jungck, Fixed points via a generalized local commutativity, Int. J. Math. Math. Sci. 25 (8) (2001) 497-507], Jachymski [J. Jachymski, A generalization of the theorem by Rhoades and Watson for contractive type mappings, Math. Japon. 38 (6) (1993) 1095-1102], Guo [C. Guo, An extension of fixed point theorem of Krasnoselski, Chinese J. Math. (P.O.C.) 21 (1) (1993) 13-20], Rhoades [B.E. Rhoades, A comparison of various definitions of contractive mappings, Trans. Amer. Math. Soc. 226 (1977) 257-290], and others.
Miniature Fixed-Point Cell Approaches for Monitoring of Thermocouple Stability
NASA Astrophysics Data System (ADS)
Failleau, G.; Elliott, C. J.; Deuzé, T.; Pearce, J. V.; Machin, G.; Sadli, M.
2014-07-01
In the framework of the European Metrology Research Project ENG08 "MetroFission," LNE-Cnam and NPL have undertaken cooperative research into the development of temperature measurement solutions for the next generation of nuclear fission power plants. Currently, in-pile temperature monitoring is usually performed with nickel-based (Type K or N) thermocouples. When these thermocouples are exposed to a neutron flux, the thermoelements transmute, leading to large and unknown drifts in output. In addition, it is impossible to routinely recalibrate the thermocouples after irradiation for obvious reasons of safety. To alleviate this problem, both LNE-Cnam and NPL have developed, via differing approaches, in situ calibration methods for the thermocouples. The self-validating thermocouple methodologies are based on the principle of a miniature fixed-point cell to be co-located with the thermocouple measurement junction in use. The drift of the thermocouple can be monitored and corrected for by regular determination of the output at the phase transition of the fixed-point material: in effect performing regular in situ calibration checks. The two institutes have constructed miniature fixed-point cells for use at three different temperatures; the freezing point of silver ; LNE-Cnam), the freezing point of copper ; LNE-Cnam and NPL), and the melting point of Fe-C (; NPL). This paper introduces the construction and validation of the miniature fixed-point cells prior to use, to ensure traceability to the ITS-90. A comparison of the performance of the two cell designs is discussed, where typical industrial Type N thermocouples have been used for measurement of the fixed-point cells. Such initial measurements demonstrate the feasibility of each of these two approaches.
The four fixed points of scale invariant single field cosmological models
Xue, BingKan
2012-10-01
We introduce a new set of flow parameters to describe the time dependence of the equation of state and the speed of sound in single field cosmological models. A scale invariant power spectrum is produced if these flow parameters satisfy specific dynamical equations. We analyze the flow of these parameters and find four types of fixed points that encompass all known single field models. Moreover, near each fixed point we uncover new models where the scale invariance of the power spectrum relies on having simultaneously time varying speed of sound and equation of state. We describe several distinctive new models and discuss constraints from strong coupling and superluminality.
Fixed Point Results for G-?-Contractive Maps with Application to Boundary Value Problems
Roshan, Jamal Rezaei
2014-01-01
We unify the concepts of G-metric, metric-like, and b-metric to define new notion of generalized b-metric-like space and discuss its topological and structural properties. In addition, certain fixed point theorems for two classes of G-?-admissible contractive mappings in such spaces are obtained and some new fixed point results are derived in corresponding partially ordered space. Moreover, some examples and an application to the existence of a solution for the first-order periodic boundary value problem are provided here to illustrate the usability of the obtained results. PMID:24895655
One loop beta functions and fixed points in higher derivative sigma models
Percacci, Roberto; Zanusso, Omar
2010-03-15
We calculate the one loop beta functions of nonlinear sigma models in four dimensions containing general two- and four-derivative terms. In the O(N) model there are four such terms and nontrivial fixed points exist for all N{>=}4. In the chiral SU(N) models there are in general six couplings, but only five for N=3 and four for N=2; we find fixed points only for N=2, 3. In the approximation considered, the four-derivative couplings are asymptotically free but the coupling in the two-derivative term has a nonzero limit. These results support the hypothesis that certain sigma models may be asymptotically safe.
Some Common Fixed Point Theorems in Complex Valued b-Metric Spaces
Mukheimer, Aiman A.
2014-01-01
Azam et al. (2011), introduce the notion of complex valued metric spaces and obtained common fixed point result for mappings in the context of complex valued metric spaces. Rao et al. (2013) introduce the notion of complex valued b-metric spaces. In this paper, we generalize the results of Azam et al. (2011), and Bhatt et al. (2011), by improving the conditions of contraction to establish the existence and uniqueness of common fixed point for two self-mappings on complex valued b-metric spaces. Some examples are given to illustrate the main results. PMID:24971385
Parallel fixed point implementation of a radial basis function network in an FPGA.
de Souza, Alisson C D; Fernandes, Marcelo A C
2014-01-01
This paper proposes a parallel fixed point radial basis function (RBF) artificial neural network (ANN), implemented in a field programmable gate array (FPGA) trained online with a least mean square (LMS) algorithm. The processing time and occupied area were analyzed for various fixed point formats. The problems of precision of the ANN response for nonlinear classification using the XOR gate and interpolation using the sine function were also analyzed in a hardware implementation. The entire project was developed using the System Generator platform (Xilinx), with a Virtex-6 xc6vcx240t-1ff1156 as the target FPGA. PMID:25268918
Parallel Fixed Point Implementation of a Radial Basis Function Network in an FPGA
de Souza, Alisson C. D.; Fernandes, Marcelo A. C.
2014-01-01
This paper proposes a parallel fixed point radial basis function (RBF) artificial neural network (ANN), implemented in a field programmable gate array (FPGA) trained online with a least mean square (LMS) algorithm. The processing time and occupied area were analyzed for various fixed point formats. The problems of precision of the ANN response for nonlinear classification using the XOR gate and interpolation using the sine function were also analyzed in a hardware implementation. The entire project was developed using the System Generator platform (Xilinx), with a Virtex-6 xc6vcx240t-1ff1156 as the target FPGA. PMID:25268918
Non-gaussian fixed point in four-dimensional pure compact U(1) gauge theory on the lattice
Jersák, Jiri; Neuhaus, T
1996-01-01
The line of phase transitions, separating the confinement and the Coulomb phases in the four-dimensional pure compact U(1) gauge theory with extended Wilson action, is reconsidered. We present new numerical evidence that a part of this line, including the original Wilson action, is of second order. By means of a high precision simulation on homogeneous lattices on a sphere we find that along this line the scaling behavior is determined by one fixed point with distinctly non-Gaussian critical exponent nu = 0.365(8). This makes the existence of a nontrivial and nonasymptotically free four-dimensional pure U(1) gauge theory in the continuum very probable. The universality and duality arguments suggest that this conclusion holds also for the monopole loop gas, for the noncompact abelian Higgs model at large negative squared bare mass, and for the corresponding effective string theory.
Fixed-point distributions of short-range Ising spin glasses on hierarchical lattices
NASA Astrophysics Data System (ADS)
Almeida, Sebastião T. O.; Nobre, Fernando D.
2015-03-01
Fixed-point distributions for the couplings of Ising spin glasses with nearest-neighbor interactions on hierarchical lattices are investigated numerically. Hierarchical lattices within the Migdal-Kadanoff family with fractal dimensions in the range 2.58 ?D ?7 , as well as a lattice of the Wheatstone-Bridge family with fractal dimension D ?3.58 are considered. Three initial distributions for the couplings are analyzed, namely, the Gaussian, bimodal, and uniform ones. In all cases, after a few iterations of the renormalization-group procedure, the associated probability distributions approached universal fixed shapes. For hierarchical lattices of the Migdal-Kadanoff family, the fixed-point distributions were well fitted either by stretched exponentials, or by q -Gaussian distributions; both fittings recover the expected Gaussian limit as D ?? . In the case of the Wheatstone-Bridge lattice, the best fit was found by means of a stretched-exponential distribution.
Fixed Points of Contractive Mappings in b-Metric-Like Spaces
Hussain, Nawab; Roshan, Jamal Rezaei
2014-01-01
We discuss topological structure of b-metric-like spaces and demonstrate a fundamental lemma for the convergence of sequences. As an application we prove certain fixed point results in the setup of such spaces for different types of contractive mappings. Finally, some periodic point results in b-metric-like spaces are obtained. Two examples are presented in order to verify the effectiveness and applicability of our main results. PMID:25143980
APMP Scale Comparison with Three Radiation Thermometers and Six Fixed-Point Blackbodies
NASA Astrophysics Data System (ADS)
Yamada, Y.; Shimizu, Y.; Ishii, J.
2015-08-01
New Asia Pacific Metrology Programme (APMP) comparisons of radiation thermometry standards, APMP TS-11, and -12, have recently been initiated. These new APMP comparisons cover the temperature range from to . Three radiation thermometers with central wavelengths of 1.6 , 0.9 , and 0.65 are the transfer devices for the radiation thermometer scale comparison conducted in the so-called star configuration. In parallel, a compact fixed-point blackbody furnace that houses six types of fixed-point cells of In, Sn, Zn, Al, Ag, and Cu is circulated, again in a star-type comparison, to substantiate fixed-point calibration capabilities. Twelve APMP national metrology institutes are taking part in this endeavor, in which the National Metrology Institute of Japan acts as the pilot. In this article, the comparison scheme is described with emphasis on the features of the transfer devices, i.e., the radiation thermometers and the fixed-point blackbodies. Results of preliminary evaluations of the performance and characteristic of these instruments as well as the evaluation method of the comparison results are presented.
Intermediate fixed point in a Luttinger liquid with elastic and dissipative backscattering
NASA Astrophysics Data System (ADS)
Altland, Alexander; Gefen, Yuval; Rosenow, Bernd
2015-08-01
In a recent work [A. Altland, Y. Gefen, and B. Rosenow, Phys. Rev. Lett. 108, 136401 (2012), 10.1103/PhysRevLett.108.136401], we have addressed the problem of a Luttinger liquid with a scatterer that allows for both coherent and incoherent scattering channels. We have found that the physics associated with this model is qualitatively different from the elastic impurity setup analyzed by Kane and Fisher, and from the inelastic scattering scenario studied by Furusaki and Matveev, thus proposing a paradigmatic picture of Luttinger liquid with an impurity. Here we present an extensive study of the renormalization group flows for this problem, the fixed point landscape, and scaling near those fixed points. Our analysis is nonperturbative in the elastic tunneling amplitudes, employing an instanton calculation in one or two of the available elastic tunneling channels. Our analysis accounts for nontrivial Klein factors, which represent anyonic or fermionic statistics. These Klein factors need to be taken into account due to the fact that higher-order tunneling processes take place. In particular, we find a stable fixed point, where an incoming current is split 1/2 -1/2 between a forward and a backward scattered beams. This intermediate fixed point, between complete backscattering and full forward scattering, is stable for the Luttinger parameter g <1 .
Remarks on lattice gauge theories with infrared-attractive fixed points
DeGrand, Thomas; Hasenfratz, Anna
2009-08-01
Theories of interacting gauge fields and fermions can possess a running gauge coupling with an infrared-attractive fixed point (IRFP). We present a minimal description of the physics of these systems and comment on some simple expectations for results from lattice simulations done within the basin of attraction of the IRFP in these theories.
A quantitative version of Kirk's fixed point theorem for asymptotic contractions
Gerhardy, Philipp
Introduction In [3], W.A. Kirk proved a fixed-point theorem for so-called asymptotic con- tractions on complete contractions as follows: Definition 1 (Kirk[3]) A function f : X X on a metric space (X, d) is called by Kirk, we derive the following alternative definition of asymptotic contractions: 3 Since an asymptotic
FIXED POINT THEOREMS FOR NONLINEAR NON-SELF MAPPINGS IN HILBERT SPACES AND
Wong, Ngai-Ching
FIXED POINT THEOREMS FOR NONLINEAR NON-SELF MAPPINGS IN HILBERT SPACES AND APPLICATIONS WATARU hybrid, in a Hilbert space which contains generalized hybrid mappings [10] and strict pseudo theorems for widely more generalized hybrid non- self mappings in a Hilbert space by using an idea of Hojo
FIXED POINT THEOREMS FOR THREE NEW NONLINEAR MAPPINGS IN BANACH SPACES
Wong, Ngai-Ching
FIXED POINT THEOREMS FOR THREE NEW NONLINEAR MAPPINGS IN BANACH SPACES WATARU TAKAHASHI, NGAI in Banach spaces which contain the class of 2-generalized hybrid mappings defined by Maruyama, Takahashi mappings in Banach spaces. 1. Introduction Let H be a real Hilbert space and let C be a nonempty closed
Weighted Fixed Points in Self-Similar Analysis of Time Series
NASA Astrophysics Data System (ADS)
Yukalov, V. I.; Gluzman, S.
The self-similar analysis of time series is generalized by introducing the notion of scenario probabilities. This makes it possible to give a complete statistical description for the forecast spectrum by defining the average forecast as a weighted fixed point and by calculating the corresponding a priori standard deviation and variance coefficient. Several examples of stock-market time series illustrate the method.
NASA Astrophysics Data System (ADS)
Edler, F.; Ederer, P.; Baratto, A. C.; Vieira, H. D.
2007-12-01
The objective of the present investigation was the determination of the melting temperatures of the eutectic compounds Fe C, Co C, and Ni C. Six eutectic fixed-point cells of the Physikalisch-Technische Bundesanstalt (PTB) (Fe C1, Fe C2, Co C1, Co C2, Ni C1, and Ni C2) and two cells of the Brazilian National Metrological Institute (Inmetro) (Fe C1V and Ni C1V), useable for the calibration of contact thermometers, were investigated. Their melting temperatures were calculated by extrapolation of the emf-temperature characteristics of four stable Pt/Pd thermocouples, which were calibrated at the eutectic fixed points and at conventional fixed points of the International Temperature Scale of 1990 (ITS-90). On the basis of the eight eutectic fixed-point cells and seven independent calibration runs, the melting temperatures of the Fe C, Co C, and Ni C eutectics resulted in 1153.67 ± 0.15°C, 1323.81 ± 0.27°C, and 1328.48 ± 0.20°C, respectively, with expanded uncertainties corresponding to a coverage factor of k = 2.
1 date: January 6, 1998 file: kearfo02 INTERVAL FIXED POINT THEORY
Kearfott, R. Baker
arithmetic. Furthermore, with outward round- ings, this evaluation can be carried out so that the floating are those of x, and whose i-th component is the lower bound xi of the i-th component xi of x. Define: The slope interval Newton method Brouwer fixed point theorem outward roundings Interval analysis
A Linear Algorithm for Solving Fixed-Point Equations on Transition Systems
Bart Vergauwen; Johan Lewi
1992-01-01
In this paper we present an algorithm for effectively computing extremal fixed-points of a system of mutually recursive equations over a finite transition system. The proposed algorithm runs in time linear in the size of the transition system and linear in the size of the system of equations, thereby improving on [AC].
2014-01-01
In the framework of ordered G-metric spaces, fixed points of maps that satisfy the generalized (?, ?)-Chatterjea type contractive conditions are obtained. The results presented in the paper generalize and extend several well known comparable results in the literature. PMID:24672307
A Common Fixed Point Theorem in Two Complete L-Fuzzy Metric Spaces
NASA Astrophysics Data System (ADS)
Sedghi, Shaban; Ghayekhloo, Somayeh; Salimi, Solaleh
2010-11-01
In this paper we first explain the concept L-fuzzy metric spaces and in this sequel explain the nation of Cauchy sequence and convergent in L-fuzzy metric spaces and finally we prove a common fixed point theorem in two complete L-fuzzy metric space.
Fixed Point Approximations for TCP Behavior in Networks of Routers Implementing
Gribaudo, Marco
Fixed Point Approximations for TCP Behavior in Networks of Routers Implementing Heterogeneous Queue to model the be- havior of a population of TCP flows traversing a network of routers im- plementing either such as router loss probability, TCP flow throughput, TCP flow end- to-end loss rates, and average round trip
Fixed point analysis of a scalar theory with an external field
Bonanno, A. [Istituto di Astronomia, Universita di Catania, Viale Andrea Doria 6, 95125 Catania (Italy)] [Istituto di Astronomia, Universita di Catania, Viale Andrea Doria 6, 95125 Catania (Italy); Zappala, D. [Dipartimento di Fisica, Universita di Catania, and INFN, sezione di Catania, Corso Italia 57, 95129 Catania (Italy)] [Dipartimento di Fisica, Universita di Catania, and INFN, sezione di Catania, Corso Italia 57, 95129 Catania (Italy)
1997-09-01
A momentum dependent projection of the Wegner-Hougton equation is derived for a scalar theory coupled to an external field. This formalism is useful to discuss the phase diagram of the theory. In particular we study some properties of the Gaussian fixed point. {copyright} {ital 1997} {ital The American Physical Society}
Fixed-point iterative sweeping methods for static Hamilton-Jacobi equations
Zhang, Yong-Tao
Fixed-point iterative sweeping methods for static Hamilton-Jacobi equations Yong-Tao Zhang1 , Hong for computations of static Hamilton-Jacobi equations. They take advantage of the properties of hyperbolic PDEs and try to cover a family of characteristics of the corresponding Hamilton-Jacobi equation in a certain
COMBINED FIXED POINT AND POLICY ITERATION FOR1 HAMILTON-JACOBI-BELLMAN EQUATIONS IN FINANCE
Forsyth, Peter A.
COMBINED FIXED POINT AND POLICY ITERATION FOR1 HAMILTON-JACOBI-BELLMAN EQUATIONS IN FINANCE 2 Y. HUANG , P.A. FORSYTH , AND G. LABAHN §3 Abstract. Implicit methods for Hamilton-Jacobi-Bellman (HJB control [25, 28,17 29], in which case the nonlinear PDEs are typically Hamilton Jacobi Bellman (HJB)18
PPF Dependent Fixed Point Results for Triangular ?c-Admissible Mappings
?iri?, Ljubomir; Alsulami, Saud M.; Salimi, Peyman
2014-01-01
We introduce the concept of triangular ?c-admissible mappings (pair of mappings) with respect to ?c nonself-mappings and establish the existence of PPF dependent fixed (coincidence) point theorems for contraction mappings involving triangular ?c-admissible mappings (pair of mappings) with respect to ?c nonself-mappings in Razumikhin class. Several interesting consequences of our theorems are also given. PMID:24672352
The Fuzzy Description Logic G-FL0 with Greatest Fixed-Point Semantics
Baader, Franz
The Fuzzy Description Logic G-FL0 with Greatest Fixed-Point Semantics Stefan Borgwardt1 , JosÃ© A the fuzzy extension of the Description Logic FL0 with semantics based on the GÃ¶del t-norm. We show restrictions (r.C). The DL ALC combines all the above constructors with negation (Â¬C). Fuzzy description logics
The log-concavity conjecture on semifree symplectic S^1-manifolds with isolated fixed points
Yunhyung Cho
2011-11-30
Let $(M,\\omega)$ be a closed $2n$-dimensional semifree Hamiltonian $S^1$-manifold with only isolated fixed points. We prove that a density function of the Duistermaat-Heckman measure is log-concave. Moreover, we prove that $(M,\\omega)$ and any reduced symplectic form satisfy the Hard Lefschetz property.
Is There a Curse of Dimensionality for Contraction Fixed Points in the Worst Case?
Traub, Joseph F.
Is There a Curse of Dimensionality for Contraction Fixed Points in the Worst Case? J. Rust, Rust (1997), Judd (1998), econometrics, Rust (1994), macroeconomics, Stokey and Lucas (1989), Cooper (1999), growth theory, Kydland and Prescott (1982), and finance and asset pricing, Lucas (1978), Rust
Combined GPS/GLONASS Precise Point Positioning with Fixed GPS Ambiguities
Pan, Lin; Cai, Changsheng; Santerre, Rock; Zhu, Jianjun
2014-01-01
Precise point positioning (PPP) technology is mostly implemented with an ambiguity-float solution. Its performance may be further improved by performing ambiguity-fixed resolution. Currently, the PPP integer ambiguity resolutions (IARs) are mainly based on GPS-only measurements. The integration of GPS and GLONASS can speed up the convergence and increase the accuracy of float ambiguity estimates, which contributes to enhancing the success rate and reliability of fixing ambiguities. This paper presents an approach of combined GPS/GLONASS PPP with fixed GPS ambiguities (GGPPP-FGA) in which GPS ambiguities are fixed into integers, while all GLONASS ambiguities are kept as float values. An improved minimum constellation method (MCM) is proposed to enhance the efficiency of GPS ambiguity fixing. Datasets from 20 globally distributed stations on two consecutive days are employed to investigate the performance of the GGPPP-FGA, including the positioning accuracy, convergence time and the time to first fix (TTFF). All datasets are processed for a time span of three hours in three scenarios, i.e., the GPS ambiguity-float solution, the GPS ambiguity-fixed resolution and the GGPPP-FGA resolution. The results indicate that the performance of the GPS ambiguity-fixed resolutions is significantly better than that of the GPS ambiguity-float solutions. In addition, the GGPPP-FGA improves the positioning accuracy by 38%, 25% and 44% and reduces the convergence time by 36%, 36% and 29% in the east, north and up coordinate components over the GPS-only ambiguity-fixed resolutions, respectively. Moreover, the TTFF is reduced by 27% after adding GLONASS observations. Wilcoxon rank sum tests and chi-square two-sample tests are made to examine the significance of the improvement on the positioning accuracy, convergence time and TTFF. PMID:25237901
Combined GPS/GLONASS precise point positioning with fixed GPS ambiguities.
Pan, Lin; Cai, Changsheng; Santerre, Rock; Zhu, Jianjun
2014-01-01
Precise point positioning (PPP) technology is mostly implemented with an ambiguity-float solution. Its performance may be further improved by performing ambiguity-fixed resolution. Currently, the PPP integer ambiguity resolutions (IARs) are mainly based on GPS-only measurements. The integration of GPS and GLONASS can speed up the convergence and increase the accuracy of float ambiguity estimates, which contributes to enhancing the success rate and reliability of fixing ambiguities. This paper presents an approach of combined GPS/GLONASS PPP with fixed GPS ambiguities (GGPPP-FGA) in which GPS ambiguities are fixed into integers, while all GLONASS ambiguities are kept as float values. An improved minimum constellation method (MCM) is proposed to enhance the efficiency of GPS ambiguity fixing. Datasets from 20 globally distributed stations on two consecutive days are employed to investigate the performance of the GGPPP-FGA, including the positioning accuracy, convergence time and the time to first fix (TTFF). All datasets are processed for a time span of three hours in three scenarios, i.e., the GPS ambiguity-float solution, the GPS ambiguity-fixed resolution and the GGPPP-FGA resolution. The results indicate that the performance of the GPS ambiguity-fixed resolutions is significantly better than that of the GPS ambiguity-float solutions. In addition, the GGPPP-FGA improves the positioning accuracy by 38%, 25% and 44% and reduces the convergence time by 36%, 36% and 29% in the east, north and up coordinate components over the GPS-only ambiguity-fixed resolutions, respectively. Moreover, the TTFF is reduced by 27% after adding GLONASS observations. Wilcoxon rank sum tests and chi-square two-sample tests are made to examine the significance of the improvement on the positioning accuracy, convergence time and TTFF. PMID:25237901
Searching for fixed point combinators by using automated theorem proving: A preliminary report
Wos, L.; McCune, W.
1988-09-01
In this report, we establish that the use of an automated theorem- proving program to study deep questions from mathematics and logic is indeed an excellent move. Among such problems, we focus mainly on that concerning the construction of fixed point combinators---a problem considered by logicians to be significant and difficult to solve, and often computationally intensive and arduous. To be a fixed point combinator, THETA must satisfy the equation THETAx = x(THETAx) for all combinators x. The specific questions on which we focus most heavily ask, for each chosen set of combinators, whether a fixed point combinator can be constructed from the members of that set. For answering questions of this type, we present a new, sound, and efficient method, called the kernel method, which can be applied quite easily by hand and very easily by an automated theorem-proving program. For the application of the kernel method by a theorem-proving program, we illustrate the vital role that is played by both paramodulation and demodulation---two of the powerful features frequently offered by an automated theorem-proving program for treating equality as if it is ''understood.'' We also state a conjecture that, if proved, establishes the completeness of the kernel method. From what we can ascertain, this method---which relies on the introduced concepts of kernel and superkernel---offers the first systematic approach for searching for fixed point combinators. We successfully apply the new kernel method to various sets of combinators and, for the set consisting of the combinators B and W, construct an infinite set of fixed point combinators such that no two of the combinators are equal even in the presence of extensionality---a law that asserts that two combinators are equal if they behave the same. 18 refs.
Synthetic foundations of cevian geometry, I: Fixed points of affine maps in triangle geometry
Igor Minevich; Patrick Morton
2015-03-29
We give synthetic proofs of many new results in triangle geometry, focusing especially on fixed points of certain affine maps which are defined in terms of the cevian triangle $DEF$ of a point $P$ with respect to a given triangle $ABC$, as well as the cevian triangle of the isotomic conjugate $P'$ of $P$ with respect to $ABC$. We prove a formula for the cyclocevian map in terms of the isotomic and isogonal maps using an entirely synthetic argument, and show that the complement $Q$ of the isotomic conjugate $P'$ has many interesting properties. If $T_P$ is the affine map taking $ABC$ to $DEF$, we show synthetically that $Q$ is the unique ordinary fixed point of $T_P$ when $P$ is any point not lying on the sides of triangle $ABC$, its anti-complementary triangle, or the Steiner circumellipse of $ABC$. We also show that $T_P(Q')=P$ if $Q'$ is the complement of $P$, and that the affine map $T_P T_{P'}$ is either a homothety or a translation which always has the $P$-ceva conjugate of $Q$ as a fixed point. Finally, we show that $P$ lies on the Steiner circumellipse if and only if $T_PT_{P'}=K^{-1}$, where $K$ is the complement map for $ABC$. This paper forms the foundation for several more papers to follow, in which the conic on the 5 points $A,B,C,P,Q$ is studied and its center is characterized as a fixed point of the map $\\lambda=T_{P'} T_P^{-1}$.
An Exact Holographic RG Flow Between 2d Conformal Fixed Points
NASA Astrophysics Data System (ADS)
Berg, Marcus; Samtleben, Henning
2002-05-01
We describe a supersymmetric RG flow between conformal fixed points of a two-dimensional quantum field theory as an analytic domain wall solution of the three-dimensional SO(4) × SO(4) gauged supergravity. Its ultraviolet fixed point is an N = (4,4) superconformal field theory related, through the double D1-D5 system, to theories modeling the statistical mechanics of black holes. The flow is driven by a relevant operator of conformal dimension ? = 3/2 which breaks conformal symmetry, breaks supersymmetry down to N = (1,1), and sends the theory to an infrared conformal fixed point with central charge cIR = cUV/2. Using the supergravity description, we compute counterterms, one-point functions and fluctuation equations for inert scalars and vector fields, providing the complete framework to compute two-point correlation functions of the corresponding operators throughout the flow in the two-dimensional quantum field theory. This produces a toy model for flows of N = 4 super Yang-Mills theory in 3+1 dimensions, where conformal-to-conformal flows have resisted analytical solution.
Evolution families of conformal mappings with fixed points and the Löwner-Kufarev equation
NASA Astrophysics Data System (ADS)
Goryainov, V. V.
2015-01-01
The paper is concerned with evolution families of conformal mappings of the unit disc to itself that fix an interior point and a boundary point. Conditions are obtained for the evolution families to be differentiable, and an existence and uniqueness theorem for an evolution equation is proved. A convergence theorem is established which describes the topology of locally uniform convergence of evolution families in terms of infinitesimal generating functions. The main result in this paper is the embedding theorem which shows that any conformal mapping of the unit disc to itself with two fixed points can be embedded into a differentiable evolution family of such mappings. This result extends the range of the parametric method in the theory of univalent functions. In this way the problem of the mutual change of the derivative at an interior point and the angular derivative at a fixed point on the boundary is solved for a class of mappings of the unit disc to itself. In particular, the rotation theorem is established for this class of mappings. Bibliography: 27 titles.
NASA Astrophysics Data System (ADS)
Yamada, Y.; Anhalt, K.; Battuello, M.; Bloembergen, P.; Khlevnoy, B.; Machin, G.; Matveyev, M.; Sadli, M.; Todd, A.; Wang, T.
2015-08-01
A multi-partner project to determine the thermodynamic temperatures of a selected set of high-temperature fixed points based on metal-carbon eutectics is underway as a working group activity within the Comité International des Poids et Mesures. The investigation focuses on four fixed-point types, namely, the three metal-carbon eutectic points of Re-C , Pt-C , and Co-C , and the Cu point . This paper describes the construction, pre-evaluation, and screening stage of the cells prior to their thermodynamic temperature determinations. The construction of the HTFP cells was undertaken by nine national metrology institutes (NMIs) according to instructions laid out in a pre-agreed protocol that ensures production of best quality cells. Four NMIs conducted the evaluation, each for a certain fixed-point type, and screened out cells that did not meet pre-determined selection criteria while assuring sufficient variety in the sources of the cells in the final selected sets. In autumn 2012, the selected cells were successfully passed on to the final stage of the project, the thermodynamic temperature measurement, and assignment.
A Fixed-Point Phase Lock Loop in a Software Defined Radio
NASA Astrophysics Data System (ADS)
Johannes, Michael T.
2002-09-01
A software defined radio is a much more flexible platform than traditional, hardware implemented radios, By implementing radio functions in software, and putting those functions on a Field Programmable Gate Array (FPGA) chip, users will have the ability to download mission specific radio capabilities. This thesis examines a fundamental piece of the receiver, the Phase-Lock Loop (PLL), simulates a software PLL, and investigates the effects of fixed-point versus floating point mathematics required for an FPGA based PLL. With a fixed-point PLL simulator, figures of merit such as lock-time, lock range, and pull-in range are determined% for typical signal-to-noise ratio (SNR) levels.
Non-Fermi liquid fixed point in a Wilsonian theory of quantum critical metals
A. Liam Fitzpatrick; Shamit Kachru; Jared Kaplan; S. Raghu
2013-09-10
We study the problem of disorder-free metals near a continuous quantum critical point. We depart from the standard paradigm of Hertz and Millis, and treat both fermions and bosons i.e. order parameter fields) on equal footing. We construct a Wilsonian effective field theory that integrates out only high energy boson and fermion modes. Below the upper critical dimension of the theory (d=3 spatial dimensions), we find new fixed points in which the bosons are described by the Wilson-Fisher fixed point and are coupled to a non-Fermi liquid metal. We describe subtleties with the renormalization group flow of four-Fermi interactions, which can be surmounted in a controlled large N limit. In this limit, we find that the theory has no superconducting instability.
Bilateral ITS-90 comparison at WC-C peritectic fixed point between NIM and NPL
NASA Astrophysics Data System (ADS)
Dong, W.; Lowe, D. H.; Lu, X.; Machin, G.; Yuan, Z.; Wang, T.; Bloembergen, P.; Xiao, C.
2013-09-01
The WC-C peritectic fixed point, nominal melting and freezing temperature 2747 °C, shows extremely good metrological potential. Elsewhere, we published a prototype scale comparison of the ITS-90 between NPL, NIM and CEM, using high temperature eutectic fixed points (HTFPs) of Co-C (1324 °C), Pt-C (1738 °C), and Re-C (2474 °C). In this paper we present the further results of the bilateral comparison of the ITS-90 at an even higher temperature, 2747 °C, between NIM and NPL using WC-C peritectic fixed points. A NIM single zone high temperature furnace, model Chino IR-80, was modified to extend its temperature to 2800 °C. Then, an NPL researcher, on secondment to NIM, filled two WC-C cells in the modified furnace in a vertical position. The two WC-C cells were then realized in the same furnace, in an horizontal position. Their melting temperatures, defined by the inflection point of the melting curves, were measured by a linear pyrometer, model NIM-PSP. NIM's ITS-90 scale was assigned to the two cells, which were then transported to NPL. The realization of NPL's ITS-90 was then assigned to the two cells by using a model HT9500 Thermogauge furnace to realize the fixed points and a linear pyrometer, model LP3, to determine their temperature. The difference from the mean value of the NIM and NPL ITS-90 values for the WC-C points was derived. This allowed us to compare ITS-90 as realized by the two institutes and to determine the uncertainty in the scale comparison.
Experimental Investigation of the Cr3C2 C Peritectic Fixed Point
NASA Astrophysics Data System (ADS)
Zheng, W.; Yamada, Y.; Wang, Y.
2008-06-01
The Cr3C2 C (1,826°C) peritectic point was investigated for its performance as a high-temperature fixed point. Dependence on the impurity content was observed, although it was less severe for the higher of the two equilibrium temperatures obtained with the same cell, the Cr3C2 C peritectic point, than for the lower, the Cr7C3 Cr3C2 eutectic point. Thermal history had an effect on the melting plateau duration, but not on the point-of-inflection temperature nor on the melting range. The melting rate had no apparent effect. The repeatability evaluated as the standard deviation of the repeated melting plateaux within a day was 20 mK for the Cr3C2 C peritectic point, while for the Cr7C3 Cr3C2 eutectic point, this was 210 mK. For both the Cr3C2 C peritectic and the Cr7C3 Cr3C2 eutectic, the freezing plateaux often showed deep supercools, which made them unsuitable for use. The observed good repeatability shows the peritectic-point performance to be comparable to the best MC-eutectic high-temperature fixed points investigated so far. The insensitivity to thermal history constitutes an important and practical advantage. The low price of chromium is a clear benefit as compared to Pt C (1,738°C) or Ru C (1,953°C) eutectic points, the M C eutectic points in this temperature range.
Realization of Open Copper Fixed-Point Cells for Thermocouple Calibration
NASA Astrophysics Data System (ADS)
Megharfi, Mohammed; Devin, Eric; Royer, Anne; Morice, Ronan
2003-09-01
BNM-LNE had studied Pt/Pd thermocouple behavior with the aim of adopting this type of sensor as an approximation of the ITS-90 above 660 °C. In order to complete a set of fixed-point cells which are available for the calibration of Pt/Pd thermocouples and other Pt-based thermocouples, BNM-LNE has recently developed an open copper fixed-point cell. This cell was developed as a test cell in order to improve the realization method, to estimate uncertainty contributions and also to determine the freezing temperature traceable to ITS-90. The cell was checked using a copper fixed-point mini-cell. This paper describes all the steps of the construction needed for cell realization and its characterization. The choice to manufacture an open cell at this point is justified in the paper. Metal impurities, metal filling conditions in the cell and atmospheric pressure effects are studied. The freezing temperature of ITS-90 was preliminarily estimated by contact thermometry awaiting a comparison with a radiation thermometry realization. The consistency of this estimated uncertainty will be confirmed by a comparison with other NMI facilities organized in Europe (Euromet project 624). This comparison is under process.
NASA Astrophysics Data System (ADS)
Machin, G.; Teixeira, R.; Lu, X.; Lowe, D.
2015-03-01
There is an on-going requirement to perform scale comparisons above the silver point with reduced uncertainties. Previous comparisons have been performed with high stability lamps or radiation thermometers, neither of which were able to achieve the required uncertainty. Ideally a set of driftless unknown temperature fixed points would be used to compare scales, but up to now such artifacts did not exist. This study develops blind high-temperature comparison artifacts based on doped versions of the high-temperature fixed point (HTFP) Ni-C (nominal temperature ). At INMETRO three HTFP blackbodies were constructed, one of pure Ni-C and two doped with different levels of Cu. To ascertain the effect of doping on the transition temperature, the cells were compared to the reference pure Ni-C cell. The doped cells were then transported to NPL and their temperatures measured. NPL was not informed of the INMETRO result ensuring that the measurements remained blind. The cells were then returned to INMETRO and re-measured to establish their stability. The temperatures measured at INMETRO and NPL were then compared and showed very good equivalence of the scale at the fixed-point temperatures. The results of the comparison of the NPL and INMETRO temperature scale, at nominally , are reported, along with evidence of the stability of the artifacts determined from repeat measurements. These promising results indicate that it may be possible to make HTFPs with altered temperatures which are stable enough to serve as comparison artifacts.
Tympanic thermometer performance validation by use of a body-temperature fixed point blackbody
NASA Astrophysics Data System (ADS)
Machin, Graham; Simpson, Robert
2003-04-01
The use of infrared tympanic thermometers within the medical community (and more generically in the public domain) has recently grown rapidly, displacing more traditional forms of thermometry such as mercury-in-glass. Besides the obvious health concerns over mercury the increase in the use of tympanic thermometers is related to a number of factors such as their speed and relatively non-invasive method of operation. The calibration and testing of such devices is covered by a number of international standards (ASTM1, prEN2, JIS3) which specify the design of calibration blackbodies. However these calibration sources are impractical for day-to-day in-situ validation purposes. In addition several studies (e.g. Modell et al4, Craig et al5) have thrown doubt on the accuracy of tympanic thermometers in clinical use. With this in mind the NPL is developing a practical, portable and robust primary reference fixed point source for tympanic thermometer validation. The aim of this simple device is to give the clinician a rapid way of validating the performance of their tympanic thermometer, enabling the detection of mal-functioning thermometers and giving confidence in the measurement to the clinician (and patient!) at point of use. The reference fixed point operates at a temperature of 36.3 °C (97.3 °F) with a repeatability of approximately +/- 20 mK. The fixed-point design has taken into consideration the optical characteristics of tympanic thermometers enabling wide-angled field of view devices to be successfully tested. The overall uncertainty of the device is estimated to be is less than 0.1°C. The paper gives a description of the fixed point, its design and construction as well as the results to date of validation tests.
Video-Based Point Cloud Generation Using Multiple Action Cameras
NASA Astrophysics Data System (ADS)
Teo, T.
2015-05-01
Due to the development of action cameras, the use of video technology for collecting geo-spatial data becomes an important trend. The objective of this study is to compare the image-mode and video-mode of multiple action cameras for 3D point clouds generation. Frame images are acquired from discrete camera stations while videos are taken from continuous trajectories. The proposed method includes five major parts: (1) camera calibration, (2) video conversion and alignment, (3) orientation modelling, (4) dense matching, and (5) evaluation. As the action cameras usually have large FOV in wide viewing mode, camera calibration plays an important role to calibrate the effect of lens distortion before image matching. Once the camera has been calibrated, the author use these action cameras to take video in an indoor environment. The videos are further converted into multiple frame images based on the frame rates. In order to overcome the time synchronous issues in between videos from different viewpoints, an additional timer APP is used to determine the time shift factor between cameras in time alignment. A structure form motion (SfM) technique is utilized to obtain the image orientations. Then, semi-global matching (SGM) algorithm is adopted to obtain dense 3D point clouds. The preliminary results indicated that the 3D points from 4K video are similar to 12MP images, but the data acquisition performance of 4K video is more efficient than 12MP digital images.
Cryostat for Fixed-Point Calibration of Capsule-Type SPRTs
NASA Astrophysics Data System (ADS)
Yang, I.; Song, C. H.; Kim, Y.-G.; Gam, K. S.
2011-12-01
A cryostat for fixed-point calibration of capsule-type SPRTs (standard platinum resistance thermometers) was developed. Using this system, cryogenic fixed points defined on the International Temperature Scale of 1990 (ITS-90) were realized. The cryogenic cells were argon, oxygen, neon, and two equilibrium-hydrogen (e-H2) cells, made by INRiM, Italy. The uncertainty of the realization of each fixed point was estimated to range from 0.53 mK to 0.43 mK ( k = 2). The realizations of the triple point of e-H2 using two sealed cells coincided within 0.1 mK. Therefore, we are able to calibrate capsule-type SPRTs down to 24.5561 K within an uncertainty of 1 mK ( k = 2) by this system. A closed-cycle helium gas refrigerator was used for the cryostat. Each sealed cell was designed so that it could accommodate three sealed cells in the thermometer wells made within the cell. Therefore, the cryostat was designed to accommodate only one sealed cell at a time. The base temperature of this liquid-free cryostat, when one sealed cell and three capsule-type SPRTs were attached for calibration, was ~17 K. For the realization of the triple point of e-H2, we used liquid helium for additional cooling. Adiabatic melting of the triple point was realized by controlling the inner-most radiation shield at a temperature very close to that of the triple point, and by applying a heat pulse by a heater directly wound to the cell. The amount of the heater power and the waiting time for the thermal equilibrium after each heat pulse were chosen in a way that the adiabatic melting could be finished within ~6 h for each cell. The triple point of each cryogenic fixed point was deduced from the equilibrium temperatures between the heat pulses and subsequent extrapolation to the liquidus point. For the oxygen cell, temperatures of two solid-solid transitions ( ?- ? and ?- ? transitions) were also measured, and the results were consistent with values reported in the literature within the designated uncertainty.
Rigorous high-precision enclosures of fixed points and their invariant manifolds
NASA Astrophysics Data System (ADS)
Wittig, Alexander N.
The well established concept of Taylor Models is introduced, which offer highly accurate C0 enclosures of functional dependencies, combining high-order polynomial approximation of functions and rigorous estimates of the truncation error, performed using verified arithmetic. The focus of this work is on the application of Taylor Models in algorithms for strongly non-linear dynamical systems. A method is proposed to extend the existing implementation of Taylor Models in COSY INFINITY from double precision coefficients to arbitrary precision coefficients. Great care is taken to maintain the highest efficiency possible by adaptively adjusting the precision of higher order coefficients in the polynomial expansion. High precision operations are based on clever combinations of elementary floating point operations yielding exact values for round-off errors. An experimental high precision interval data type is developed and implemented. Algorithms for the verified computation of intrinsic functions based on the High Precision Interval datatype are developed and described in detail. The application of these operations in the implementation of High Precision Taylor Models is discussed. An application of Taylor Model methods to the verification of fixed points is presented by verifying the existence of a period 15 fixed point in a near standard Henon map. Verification is performed using different verified methods such as double precision Taylor Models, High Precision intervals and High Precision Taylor Models. Results and performance of each method are compared. An automated rigorous fixed point finder is implemented, allowing the fully automated search for all fixed points of a function within a given domain. It returns a list of verified enclosures of each fixed point, optionally verifying uniqueness within these enclosures. An application of the fixed point finder to the rigorous analysis of beam transfer maps in accelerator physics is presented. Previous work done by Johannes Grote is extended to compute very accurate polynomial approximations to invariant manifolds of discrete maps of arbitrary dimension around hyperbolic fixed points. The algorithm presented allows for automatic removal of resonances occurring during construction. A method for the rigorous enclosure of invariant manifolds of continuous systems is introduced. Using methods developed for discrete maps, polynomial approximations of invariant manifolds of hyperbolic fixed points of ODEs are obtained. These approximations are outfit with a sharp error bound which is verified to rigorously contain the manifolds. While we focus on the three dimensional case, verification in higher dimensions is possible using similar techniques. Integrating the resulting enclosures using the verified COSY VI integrator, the initial manifold enclosures are expanded to yield sharp enclosures of large parts of the stable and unstable manifolds. To demonstrate the effectiveness of this method, we construct enclosures of the invariant manifolds of the Lorenz system and show pictures of the resulting manifold enclosures. To the best of our knowledge, these enclosures are the largest verified enclosures of manifolds in the Lorenz system in existence.
Probability of local bifurcation type from a fixed point: A random matrix perspective
D. J. Albers; J. C. Sprott
2005-10-24
Results regarding probable bifurcations from fixed points are presented in the context of general dynamical systems (real, random matrices), time-delay dynamical systems (companion matrices), and a set of mappings known for their properties as universal approximators (neural networks). The eigenvalue spectra is considered both numerically and analytically using previous work of Edelman et. al. Based upon the numerical evidence, various conjectures are presented. The conclusion is that in many circumstances, most bifurcations from fixed points of large dynamical systems will be due to complex eigenvalues. Nevertheless, surprising situations are presented for which the aforementioned conclusion is not general, e.g. real random matrices with Gaussian elements with a large positive mean and finite variance.
The fixed point formulation for large sample PGNAA—Part 1: theory
NASA Astrophysics Data System (ADS)
Holloway, J. P.; Akkurt, H.
2004-04-01
The determination of large sample composition via prompt gamma measurements is examined as a non-linear inverse problem. We show that this non-linear problem can be formulated as a fixed point problem that always has a physically meaningful solution, even in the presence of significant contributions to photopeak area from gammas emitted by the surroundings. The formulation involves only ratios of measured photopeak areas, and, separately, ratios of modeled photopeak areas. It therefore does not require the absolute comparison of measured or modeled quantities. The proof of the existence of meaningful solutions relies on very simple and natural hypotheses of positivity and continuity. The natural fixed point iteration is examined, and certain physical limits where its global convergence can be guaranteed are examined. Several computational examples are presented.
The fixed point formulation for large sample PGNAA—Part 2: experimental demonstration
NASA Astrophysics Data System (ADS)
Akkurt, H.; Holloway, J. P.; Smith, L. E.
2004-04-01
We present composition estimation results using fixed point iteration compared to the true composition of sample for prompt gamma measurements. The analysis showed that the fixed point iteration algorithm converges very rapidly to true composition of the sample independent of the initial guess when there is no significant background contribution. Even in the presence of significant background contribution, the true composition of the sample was estimated with high precision but with slower convergence. Although approximate data for neutron source spectrum and relative efficiency of the detector was used for analysis, the results showed that the method is not very sensitive to the details of the model since it is based on ratios. Despite the approximate data used for computations, the composition estimation results are in excellent agreement with chemical analysis.
Fixed-point quantum search with an optimal number of queries.
Yoder, Theodore J; Low, Guang Hao; Chuang, Isaac L
2014-11-21
Grover's quantum search and its generalization, quantum amplitude amplification, provide a quadratic advantage over classical algorithms for a diverse set of tasks but are tricky to use without knowing beforehand what fraction ? of the initial state is comprised of the target states. In contrast, fixed-point search algorithms need only a reliable lower bound on this fraction but, as a consequence, lose the very quadratic advantage that makes Grover's algorithm so appealing. Here we provide the first version of amplitude amplification that achieves fixed-point behavior without sacrificing the quantum speedup. Our result incorporates an adjustable bound on the failure probability and, for a given number of oracle queries, guarantees that this bound is satisfied over the broadest possible range of ?. PMID:25479481
Fixed-Point Quantum Search with an Optimal Number of Queries
NASA Astrophysics Data System (ADS)
Yoder, Theodore J.; Low, Guang Hao; Chuang, Isaac L.
2014-11-01
Grover's quantum search and its generalization, quantum amplitude amplification, provide a quadratic advantage over classical algorithms for a diverse set of tasks but are tricky to use without knowing beforehand what fraction ? of the initial state is comprised of the target states. In contrast, fixed-point search algorithms need only a reliable lower bound on this fraction but, as a consequence, lose the very quadratic advantage that makes Grover's algorithm so appealing. Here we provide the first version of amplitude amplification that achieves fixed-point behavior without sacrificing the quantum speedup. Our result incorporates an adjustable bound on the failure probability and, for a given number of oracle queries, guarantees that this bound is satisfied over the broadest possible range of ? .
Emittance and damping of electrons in the neighborhood of resonance fixed points
Crosbie, E.A.
1993-07-01
The stable fixed points generated by nonlinear field harmonics in a cyclic lattice define a multiturn stable orbit. The position of the orbit for each turn in each magnet of the lattice determines the betatron tunes and lattice dispersion functions describing the linear motion of charged particles with respect to the stable orbit. Since the position of the fixed points is dependent in part on the central orbit tune, it turns out that the multiturn orbit dispersion function depends to a large extent on the central orbit chromaticity. In particular, the horizontal partition number can be made to vary from values less than zero (horizontal antidamping for electrons) to values greater than three (longitudinal antidamping). The central orbit chromaticity therefore plays a major role in determining the characteristic emittance of an electron beam with respect to the multiturn orbit.
Wilson, fixed point and Neuberger's lattice Dirac operator for the Schwinger model
Farchioni, F; Lang, C B
1998-01-01
We perform a comparison between different lattice regularizations of the Dirac operator for massless fermions in the framework of the single and two flavor Schwinger model. We consider a) the Wilson-Dirac operator at the critical value of the hopping parameter; b) Neuberger's overlap operator; c) the fixed point operator. We test chiral properties of the spectrum, dispersion relations and rotational invariance of the mesonic bound state propagators.
The analysis of the number of fixed points in the key extending algorithm of RC4
Kejian Xu; Liang He; Zhaopeng Dai; Xiubin Fan
2008-01-01
The probabilities of the state transitions of the initial value S\\u000a 0 in the S table of RC4 are described by a kind of bistochastic matrices, and then a computational formula for such bistochastic matrices\\u000a is given, by which the mathematical expectation of the number of fixed points in the key extending algorithm of RC4 is obtained.\\u000a As a result,
FullyDiverse MultipleAntenna Signal Constellations and FixedPointFree Lie Groups
Hassibi, Babak
FullyÂDiverse MultipleÂAntenna Signal Constellations and FixedÂPointÂFree Lie Groups Babak Hassibi groups and, in particular, their most interesting case, Lie groups. Two such fpf Lie groups are currentlyÂtransmitÂantenna schemes are based. In LieÂgroupÂtheoretic jargon these are referred to as U(1) and SU(2). A natural
Fixed-point fluid–structure interaction solvers with dynamic relaxation
Ulrich Küttler; Wolfgang A. Wall
2008-01-01
A fixed-point fluid–structure interaction (FSI) solver with dynamic relaxation is revisited. New developments and insights\\u000a gained in recent years motivated us to present an FSI solver with simplicity and robustness in a wide range of applications.\\u000a Particular emphasis is placed on the calculation of the relaxation parameter by both Aitken’s $${\\\\Delta^{2}}$$ method and the method of steepest descent. These methods
Modified van der Pauw method based on formulas solvable by the Banach fixed point method
Cie?li?ski, Jan L
2012-01-01
We propose a modification of the standard van der Pauw method for determining the resistivity and Hall coefficient of flat thin samples of arbitrary shape. Considering a different choice of resistance measurements we derive a new formula which can be numerically solved (with respect to sheet resistance) by the Banach fixed point method for any values of experimental data. The convergence is especially fast in the case of almost symmetric van der Pauw configurations (e.g., clover shaped samples).
Modified van der Pauw method based on formulas solvable by the Banach fixed point method
Jan L. Cie?li?ski
2012-03-31
We propose a modification of the standard van der Pauw method for determining the resistivity and Hall coefficient of flat thin samples of arbitrary shape. Considering a different choice of resistance measurements we derive a new formula which can be numerically solved (with respect to sheet resistance) by the Banach fixed point method for any values of experimental data. The convergence is especially fast in the case of almost symmetric van der Pauw configurations (e.g., clover shaped samples).
5d fixed points from brane webs and O7-planes
Oren Bergman; Gabi Zafrir
2015-08-15
We explore the properties of five-dimensional supersymmetric gauge theories living on 5-brane webs in orientifold 7-plane backgrounds. These include $USp(2N)$ and $SO(N)$ gauge theories with fundamental matter, as well as $SU(N)$ gauge theories with symmetric and antisymmetric matter. We find a number of new 5d fixed point theories that feature enhanced global symmetries. We also exhibit a number of new 5d dualities.
Furnace for High-Temperature Metal (Carbide)Carbon Eutectic Fixed-Point
B. Khlevnoy; M. Sakharov; S. Ogarev; V. Sapritsky; Y. Yamada; K. Anhalt
A new large-area furnace with maximum temperature of 3500 K was designed at the VNIIOFI as a furnace for high-temperature M(C)-C fixed points, and then investigated at the NMIJ. Temperature uniformity was investigated as to its dependence on various heater and cell holder arrangements. One Re-C and one TiC-C cells were made using BB3500YY and then compared with a Re-C
Bifurcation from stable fixed point to N-dimensional attractor in the border collision normal form
NASA Astrophysics Data System (ADS)
Glendinning, Paul
2015-10-01
The N-dimensional border collision normal form describes bifurcations of piecewise smooth systems. It is shown that there is an open set of parameters such that on one side of the bifurcation the map has a stable fixed point and on the other an attractor with Hausdorff dimension N. For generic parameters this attractor contains open sets and hence has topological dimension equal to N.
Long-Term Monitoring of Thermocouple Stability with Miniature Fixed-Point Cells
NASA Astrophysics Data System (ADS)
Elliott, C. J.; Failleau, G.; Deuzé, T.; Sadli, M.; Pearce, J. V.; Machin, G.
2014-04-01
In the framework of the European Metrology Research Programme ENG08 "MetroFission" project, two National Measurement Institutes, LNE-Cnam (France) and NPL (UK), have cooperatively developed methods of in situ validation of thermocouple output for application in next-generation nuclear fission power plants. Miniature fixed-point cells for use at three temperatures were constructed in the first step of this project: at the freezing point of silver (), the freezing point of copper (), and the melting point of the iron-carbon eutectic (). This paper reports the results of a second step in the study, where the robustness of the self-validation method has been investigated. Typical industrial Type N thermocouples have been employed with each of the miniature fixed-point devices installed, and repeatedly thermally cycled through the melting and freezing transitions of the fixed-point ingots. The devices have been exposed to a total of up to 90 h in the molten state. Furthermore, the LNE-Cnam devices were also subjected to fast cool-down rates, on five occasions, where the rate is estimated to have been between and . The devices are shown to be repeatable, reliable, and robust over the course of these tests. The drift of the Type N thermocouple has been identified separately to the behavior of the device. A reliable method for improving thermocouple performance and process control is therefore demonstrated. Requirements for implementation and the advantages of each approach for monitoring and correcting thermocouple drift are discussed, and an uncertainty budget for self-validation is presented.
Nonthermal fixed points, vortex statistics, and superfluid turbulence in an ultracold Bose gas
NASA Astrophysics Data System (ADS)
Nowak, Boris; Schole, Jan; Sexty, Dénes; Gasenzer, Thomas
2012-04-01
Nonthermal fixed points of the dynamics of a dilute degenerate Bose gas far from thermal equilibrium are analyzed in two and three spatial dimensions. Universal power-law distributions, previously found within a nonperturbative quantum-field theoretical approach and recently shown to be related to vortical dynamics and superfluid turbulence [Phys. Rev. B1098-012110.1103/PhysRevB.84.020506 84, 020506(R) (2011)], are studied in detail. The results imply an interpretation of the scaling behavior in terms of independent vortex excitations of the superfluid and show that the statistics of topological excitations can be described in the framework of wave turbulence. The particular scaling exponents observed in the single-particle momentum distributions are found to be consistent with irreversibility as well as conservation laws obeyed by the wave interactions. Moreover, long-wavelength acoustic excitations of the vortex-bearing condensate, driven by vortex annihilations, are found to follow a nonthermal power law. Considering vortex correlations in a statistical model, the long-time departure from the nonthermal fixed point is related to vortex-antivortex pairing. The studied nonthermal fixed points are accessible in cold-gas experiments. The results shed light on fundamental aspects of superfluid turbulence and have strong potential implications for related phenomena, for example, in early universe inflation or quark-gluon plasma dynamics.
New Experimental Technique for the Study of Phase Transition Evolution in Fixed-Point Cells
NASA Astrophysics Data System (ADS)
Nemeth, T.; Nemeth, S.; Turzo-Andras, E.
2015-08-01
A new advanced technique was developed at the Hungarian Metrological Institute (MKEH), devoted to optimizing the realization of the International Temperature Scale ITS-90. The work was performed within the framework of the European project "Novel techniques for traceable temperature dissemination." The paper is devoted to describing this new measurement technique and its setup. The time evolution of the solid fraction and melt fraction along the phase transformation has been followed, using a technique based on the difference of the electrical conductivity between the solid and liquid phases of the metal. The measurement technique provides electrical signals, which are suitable for improving the quality of the freezing plateaus realized in the case of different fixed-point realizations, covering the temperature range from to . The ideal section of the freezing plateau can be maintained by ensuring a continuous flow of mass and energy of the fixed-point substance in the axial direction. The intervention is achieved by modifying the temperatures of the different zones of the furnace controller with more degrees, with the aid of developed intervening devices. Recent developments permit the selection of the ideal section of a freezing plateau and, what is more, the increase of this plateau section to practically unlimited for all metal fixed points.
New Experimental Technique for the Study of Phase Transition Evolution in Fixed-Point Cells
NASA Astrophysics Data System (ADS)
Nemeth, T.; Nemeth, S.; Turzo-Andras, E.
2015-04-01
A new advanced technique was developed at the Hungarian Metrological Institute (MKEH), devoted to optimizing the realization of the International Temperature Scale ITS-90. The work was performed within the framework of the European project "Novel techniques for traceable temperature dissemination." The paper is devoted to describing this new measurement technique and its setup. The time evolution of the solid fraction and melt fraction along the phase transformation has been followed, using a technique based on the difference of the electrical conductivity between the solid and liquid phases of the metal. The measurement technique provides electrical signals, which are suitable for improving the quality of the freezing plateaus realized in the case of different fixed-point realizations, covering the temperature range from -39°C to 962°C. The ideal section of the freezing plateau can be maintained by ensuring a continuous flow of mass and energy of the fixed-point substance in the axial direction. The intervention is achieved by modifying the temperatures of the different zones of the furnace controller with more degrees, with the aid of developed intervening devices. Recent developments permit the selection of the ideal section of a freezing plateau and, what is more, the increase of this plateau section to practically unlimited for all metal fixed points.
Planar embeddability of the vertices of a graph using a fixed point set is NP-hard
Utrecht, Universiteit
Planar embeddability of the vertices of a graph using a fixed point set is NP-hard Sergio Cabello.cs.uu.nl #12;Planar embeddability of the vertices of a graph using a fixed point set is NP-hard Sergio Cabello
Isotopic effects in the neon fixed point: uncertainty of the calibration data correction
NASA Astrophysics Data System (ADS)
Steur, Peter P. M.; Pavese, Franco; Fellmuth, Bernd; Hermier, Yves; Hill, Kenneth D.; Seog Kim, Jin; Lipinski, Leszek; Nagao, Keisuke; Nakano, Tohru; Peruzzi, Andrea; Sparasci, Fernando; Szmyrka-Grzebyk, Anna; Tamura, Osamu; Tew, Weston L.; Valkiers, Staf; van Geel, Jan
2015-02-01
The neon triple point is one of the defining fixed points of the International Temperature Scale of 1990 (ITS-90). Although recognizing that natural neon is a mixture of isotopes, the ITS-90 definition only states that the neon should be of ‘natural isotopic composition’, without any further requirements. A preliminary study in 2005 indicated that most of the observed variability in the realized neon triple point temperatures within a range of about 0.5?mK can be attributed to the variability in isotopic composition among different samples of ‘natural’ neon. Based on the results of an International Project (EUROMET Project No. 770), the Consultative Committee for Thermometry decided to improve the realization of the neon fixed point by assigning the ITS-90 temperature value 24.5561?K to neon with the isotopic composition recommended by IUPAC, accompanied by a quadratic equation to take the deviations from the reference composition into account. In this paper, the uncertainties of the equation are discussed and an uncertainty budget is presented. The resulting standard uncertainty due to the isotopic effect (k = 1) after correction of the calibration data is reduced to (4 to 40)??K when using neon of ‘natural’ isotopic composition or to 30??K when using 20Ne. For comparison, an uncertainty component of 0.15?mK should be included in the uncertainty budget for the neon triple point if the isotopic composition is unknown, i.e. whenever the correction cannot be applied.
NASA Astrophysics Data System (ADS)
Yamada, Y.; Wang, Y.; Sasajima, N.
2006-10-01
WC-C, Cr3C2-C and Mn7C3-C peritectic systems were investigated for their potential of serving as high-temperature reference points in thermometry. Mixtures of high-purity graphite powder with W, Cr and Mn powder of 99.99%, 99.9% and 99.95% purity by mass, respectively, were placed in graphite blackbody crucibles and melting/freezing plateaus were observed by means of a radiation thermometer. The observed melting temperatures were 2749 °C (WC-C), 1826 °C (Cr3C2-C) and 1331 °C (Mn7C3-C), with a repeatability—in each case—of 0.02 K. The melting range for WC-C and Cr3C2-C peritectics was roughly 0.1 K. WC-C showed a flat freezing plateau that agreed with the melting plateau within the repeatability. The three fixed points are possible candidates, like the metal (carbide)-carbon eutectic fixed points, in the realization of an improved high-temperature scale above the copper point.
High-Temperature Fixed-Point Facilities for Improved Thermocouple Calibration—Euromet Project 857
NASA Astrophysics Data System (ADS)
Morice, R.; Edler, F.; Pearce, J.; Machin, G.; Fischer, J.; Filtz, J. R.
2008-02-01
LNE, NPL, and PTB decided in 2005 to join their research efforts in the framework of Euromet Project 857 with the aim of reducing the calibration uncertainty of noble metal and other high-temperature thermocouples by at least a factor of two. This ambitious target will be met through the development and implementation of robust high-temperature fixed points based on metal carbon eutectic technology. The Euromet project is structured around five work packages and ensures good and efficient cooperation between the partners to meet the objectives within the project timeframe of four years. Furthermore, a formal cooperative research agreement has been established with the National Metrology Institute of Japan (NMIJ) to demonstrate, on a worldwide basis, that this new method is a significant improvement over current calibration methods. In summary, the project consists of (a) the development of sets of cells at the cobalt carbon eutectic point (1324?C) and palladium carbon eutectic point (1492?C) and (b) the construction of platinum/palladium (Pt/Pd) thermocouples carefully stabilized for use to these temperatures. Supplementary research to be undertaken as part of this project is the improvement of fixed-point construction and realization capabilities through high-temperature furnaces with low thermal gradients. This paper describes the European project and gives an overview of current progress.
Infrared behavior and fixed-point structure in the compactified Ginzburg--Landau model
C. A. Linhares; A. P. C. Malbouisson; M. L. Souza
2011-02-07
We consider the Euclidean $N$-component Ginzburg--Landau model in $D$ dimensions, of which $d$ ($d\\leq D$) of them are compactified. As usual, temperature is introduced through the mass term in the Hamiltonian. This model can be interpreted as describing a system in a region of the $D$-dimensional space, limited by $d$ pairs of parallel planes, orthogonal to the coordinates axis $x_1,\\,x_2,\\,...,\\,x_d$. The planes in each pair are separated by distances $L_1,\\;L_2,\\; ...,\\,L_d$. For $D=3$, from a physical point of view, the system can be supposed to describe, in the cases of $d=1$, $d=2$, and $d=3$, respectively, a superconducting material in the form of a film, of an infinitely long wire having a retangular cross-section and of a brick-shaped grain. We investigate in the large-$N$ limit the fixed-point structure of the model, in the absence or presence of an external magnetic field. An infrared-stable fixed point is found, whether of not an external magnetic field is applied, but for different ranges of values of the space dimension $ D$.
Fixed-Point Thermocouples in Power Plants: Long-Term Operational Experiences
NASA Astrophysics Data System (ADS)
Lehmann, H.
2010-09-01
For more than four years, commercially available fixed-point thermocouples have measured hot-steam temperatures in power plants. A periodic self-adjustment procedure should keep their total measuring uncertainty within 1 K. This paper gives a short introduction to the measuring system components and their function. Despite heavy mechanical and thermal loads, the sensing elements show high reliability and appropriate availability. To evaluate the long-term reproducibility of the method, single thermometers have been dismantled and recalibrated in the laboratory at different time intervals. After more than 35 000 h of hard routine service the results have confirmed the expected uncertainty level.
The infrared fixed point of Landau gauge Yang-Mills theory
Axel Weber
2012-11-07
Over the last decade, the infrared behavior of Yang-Mills theory in the Landau gauge has been scrutinized with the help of Dyson-Schwinger equations and lattice calculations. In this contribution, we describe a technically simple approach to the deep infrared regime via Callan-Symanzik renormalization group equations in an epsilon expansion. This approach recovers, in an analytical and systematically improvable way, all the solutions previously found as solutions of the Dyson-Schwinger equations and singles out the solution favored by lattice calculations as the infrared-stable fixed point (for space-time dimensions above two).
Global solutions of functional fixed point equations via pseudo-spectral methods
Julia Borchardt; Benjamin Knorr
2015-09-02
We apply pseudo-spectral methods to construct global solutions of functional renormalisation group equations in field space to high accuracy. For this, we introduce a basis to resolve both finite as well as asymptotic regions of effective potentials. Our approach is benchmarked using the critical behaviour of the scalar $O(1)$ model, providing results for the global fixed point potential as well as leading critical exponents and their respective global eigenfunctions. We provide new results for (1) multi-critical $O(1)$ models in fractional dimensions, (2) the three-dimensional Gross-Neveu model at both small and large $N$, and (3) the scalar-tensor model, also in three dimensions.
Uncertainty due to non-linearity in radiation thermometers calibrated by multiple fixed points
Yamaguchi, Y.; Yamada, Y. [National Metrology Institute of Japan, AIST, Tsukuba, Ibaraki (Japan)] [National Metrology Institute of Japan, AIST, Tsukuba, Ibaraki (Japan)
2013-09-11
A new method to estimate the uncertainty due to non-linearity is described on the n= 3 scheme basis. The expression of uncertainty is mathematically derived applying the random walk method. The expression is simple and requires only the temperatures of the fixed points and a relative uncertainty value for each flux-doubling derived from the non-linearity measurement. We also present an example of the method, in which the uncertainty of temperature measurement by a radiation thermometer is calculated on the basis of non-linearity measurement.
Finiteness of fixed equilibrium configurations of point vortices in the plane with a background flow
NASA Astrophysics Data System (ADS)
Cheung, Pak-Leong; Ng, Tuen Wai
2014-10-01
For a dynamic system consisting of n point vortices in an ideal plane fluid with a steady, incompressible and irrotational background flow, a more physically significant definition of a fixed equilibrium configuration is suggested. Under this new definition, if the complex polynomial w that determines the aforesaid background flow is non-constant, we have found an attainable generic upper bound \\frac{(m+n-1)!}{(m-1)!\\,n_1!\\cdots n_{i_0}!} for the number of fixed equilibrium configurations. Here, m = deg w, i0 is the number of species, and each ni is the number of vortices in a species. We transform the rational function system arising from fixed equilibria into a polynomial system, whose form is good enough to apply the BKK theory (named after Bernshtein (1975 Funct. Anal. Appl. 9 183-5), Khovanskii (1978 Funct. Anal. Appl. 12 38-46) and Kushnirenko (1976 Funct. Anal. Appl. 10 233-5)) to show the finiteness of its number of solutions. Having this finiteness, the required bound follows from Bézout's theorem or the BKK root count by Li and Wang (1996 Math. Comput. 65 1477-84).
Design, Construction, and Evaluation of Ni-C Eutectic Fixed Points
NASA Astrophysics Data System (ADS)
Bojkovski, J.; Hiti, M.; Batagelj, V.; Drnovšek, J.
2011-08-01
In this article the design, construction, and evaluation of eutectic fixed points for contact and non-contact measurements that have been recently developed at MIRS/UL/FE-LMK are presented. The design of the cells is made in such way that it can be used for only thermocouple calibration in vertical or horizontal furnaces, for calibration of pyrometers in a horizontal furnace, and for simultaneous calibration of contact and non-contact thermometers in a horizontal furnace. Special care has been taken to achieve repeatability and reproducibility of the transition temperatures and mechanical robustness of the cell. This includes also usage of a carbon sleeve in combination with carbon sheets, in a so-called hybrid design of the eutectic cell. With such a design, significant improvement in mechanical robustness of the cell and temperature stability of the cell has been achieved. All the measurements are performed within specially designed seven-zone furnaces within which different gradients, and different heating and cooling rates can be realized. The melting temperature of Ni-C ((1328.44 ± 0.70) °C) measured with a thermocouple type R, calibrated at the zinc, aluminum, silver, copper, and palladium fixed points, and a non-contact thermometer, calibrated by comparison against different blackbodies, agree within their expanded uncertainties of 0.7 °C and 1.5 °C, respectively.
Müezzinoglu, Mehmet Kerem; Güzeli?, Cüneyt; Zurada, Jacek M
2005-03-01
An energy function-based autoassociative memory design method to store a given set of unipolar binary memory vectors as attractive fixed points of an asynchronous discrete Hopfield network (DHN) is presented. The discrete quadratic energy function whose local minima correspond to the attractive fixed points of the network is constructed via solving a system of linear inequalities derived from the strict local minimality conditions. The weights and the thresholds are then calculated using this energy function. If the inequality system is infeasible, we conclude that no such asynchronous DHN exists, and extend the method to design a discrete piecewise quadratic energy function, which can be minimized by a generalized version of the conventional DHN, also proposed herein. In spite of its computational complexity, computer simulations indicate that the original method performs better than the conventional design methods in the sense that the memory can store, and provide the attractiveness for almost all memory sets whose cardinality is less than or equal to the dimension of its elements. The overall method, together with its extension, guarantees the storage of an arbitrary collection of memory vectors, which are mutually at least two Hamming distances away from each other, in the resulting network. PMID:15787144
Stability of cobalt–carbon high temperature fixed points doped with iron and platinum
NASA Astrophysics Data System (ADS)
K?azovická, L.; Lowe, D.; Machin, G.; Davies, H.; Rani, A.
2015-04-01
High temperature fixed points (HTFPs) are stable and repeatable and make comparison of temperature scales possible at a level of uncertainty not previously possible. However, they potentially lack objectivity if the fixed-point temperature is known. Five HTFPs were constructed, one pure Co–C, two Co–C doped with Fe and two Co–C doped with Pt of differing concentrations. The candidate dopants were identified through thermochemical modelling as likely to give maximum temperature shift with minimum increase in melting range. The temperature differences of the doped systems from the pure system were determined and it was found that the addition of Fe depressed the melting temperature and the addition of Pt elevated the melting temperature, qualitatively in line with the thermochemical modelling. The higher concentration doped HTFPs were then aged for approximately 100?h with continuous melting–freezing cycles and the difference to the undoped Co–C HTFP remeasured. These differences were found to agree with those of the unaged results within the measurement uncertainties, confirming artefact stability. It is clear that the doping of HTFPs is a powerful way of constructing stable and reliable high temperature scale comparison artefacts of unknown temperature.
Quantum-corrected drift-diffusion models: Solution fixed point map and finite element approximation
Falco, Carlo de; Jerome, Joseph W.; Sacco, Riccardo
2009-03-20
This article deals with the analysis of the functional iteration, denoted Generalized Gummel Map (GGM), proposed in [C. de Falco, A.L. Lacaita, E. Gatti, R. Sacco, Quantum-Corrected Drift-Diffusion Models for Transport in Semiconductor Devices, J. Comp. Phys. 204 (2) (2005) 533-561] for the decoupled solution of the Quantum Drift-Diffusion (QDD) model. The solution of the problem is characterized as being a fixed point of the GGM, which permits the establishment of a close link between the theoretical existence analysis and the implementation of a numerical tool, which was lacking in previous non-constructive proofs [N.B. Abdallah, A. Unterreiter, On the stationary quantum drift-diffusion model, Z. Angew. Math. Phys. 49 (1998) 251-275, R. Pinnau, A. Unterreiter, The stationary current-voltage characteristics of the quantum drift-diffusion model, SIAM J. Numer. Anal. 37 (1) (1999) 211-245]. The finite element approximation of the GGM is illustrated, and the main properties of the numerical fixed point map (discrete maximum principle and order of convergence) are discussed. Numerical results on realistic nanoscale devices are included to support the theoretical conclusions.
Stability of a cubic fixed point in three dimensions: Critical exponents for generic N
NASA Astrophysics Data System (ADS)
Varnashev, K. B.
2000-06-01
The detailed analysis of the global structure of the renormalization-group (RG) flow diagram for a model with isotropic and cubic interactions is carried out in the framework of the massive field theory directly in three dimensions (3D) within an assumption of isotropic exchange. Perturbative expansions for RG functions are calculated for arbitrary N up to four-loop order and resummed by means of the generalized Padé-Borel-Leroy technique. Coordinates and stability matrix eigenvalues for the cubic fixed point are found under the optimal value of the transformation parameter. Critical dimensionality of the model is proved to be equal to Nc=2.89+/-0.02 that agrees well with the estimate obtained on the basis of the five-loop ? expansion [H. Kleinert and V. Schulte-Frohlinde, Phys. Lett. B 342, 284 (1995)] resummed by the above method. As a consequence, the cubic fixed point should be stable in 3D for N>=3, and the critical exponents controlling phase transitions in three-dimensional magnets should belong to the cubic universality class. The critical behavior of the random Ising model being the nontrivial particular case of the cubic model when N=0 is also investigated. For all physical quantities of interest the most accurate numerical estimates with their error bounds are obtained. The results achieved in the work are discussed along with the predictions given by other theoretical approaches and experimental data.
Temperature determination of the Si–SiC eutectic fixed point using thermocouples
NASA Astrophysics Data System (ADS)
Suherlan; Kim, Yong-Gyoo; Joung, Wukchul; Yang, Inseok
2015-04-01
The temperature of the Si–SiC eutectic fixed point for use in thermocouple thermometry has been determined. Three Si–SiC cells were fabricated from pure silicon powder within separate graphite crucibles. Each of the three cells was cycled through 17 melt–freeze cycles and subjected to temperatures above 1400?°C for a period of approximately 73?h, and none showed any sign of mechanical failure. The melting transition was measured using three types of thermocouple: one type S, one type B, and two Pt/Pd thermocouples calibrated at the fixed points of Ag, Cu, Fe–C, Co–C, and Pd (only for type B). The transition temperature, measured using the type S and two Pt/Pd thermocouples, was (1410.0 ± 0.8)?°C with k = 2. However, the measurement uncertainty using the type B thermocouple was as large as 1.5?°C (k = 2) due to the inhomogeneity of the thermocouple. The repeatability of the three Si–SiC cells was calculated to be 0.3?°C, and the extremes of the temperature measurement differed by 0.8?°C.
Optimization of the thermogauge furnace for realizing high temperature fixed points
Wang, T.; Dong, W. [National Institute of Metrology (NIM), Beijing (China)] [National Institute of Metrology (NIM), Beijing (China); Liu, F. [AVIC China Precision Engineering Institute for Aircraft Industry, Beijing (China)] [AVIC China Precision Engineering Institute for Aircraft Industry, Beijing (China)
2013-09-11
The thermogauge furnace was commonly used in many NMIs as a blackbody source for calibration of the radiation thermometer. It can also be used for realizing the high temperature fixed point(HTFP). According to our experience, when realizing HTFP we need the furnace provide relative good temperature uniformity to avoid the possible damage to the HTFP. To improve temperature uniformity in the furnace, the furnace tube was machined near the tube ends with a help of a simulation analysis by 'ansys workbench'. Temperature distributions before and after optimization were measured and compared at 1300 °C, 1700°C, 2500 °C, which roughly correspond to Co-C(1324 °C), Pt-C(1738 °C) and Re-C(2474 °C), respectively. The results clearly indicate that through machining the tube the temperature uniformity of the Thermogage furnace can be remarkably improved. A Pt-C high temperature fixed point was realized in the modified Thermogauge furnace subsequently, the plateaus were compared with what obtained using old heater, and the results were presented in this paper.
A Comparison of Visual Fields with Fixed and Moving Fixation Points. Volume II
NASA Astrophysics Data System (ADS)
McLean, William E.
2002-09-01
Four procedures were used to measure the extent of the detection fields of four primary meridians of the binocular visual fields of four subjects. Procedures I (Moving Target) used a horizontally moving target and a stationary fixation point. Procedure II (Fixed Target) used a stationary target and a horizontally moving fixation point. Procedure III (Saccadic Move) used a saccadic eye movement between two stationary horizontal fixation points and a stationary target. Procedure IV (Flashed Target) used a stationary fixation point and a .6 second flashed target. The results from the dynamic procedures (I and II) and the two static procedures (III and IV) were very similar for each subject. In the dynamic procedures, the relationship between a change in contrast and an equivalent change in velocity tends to support Bloch's Law (IxT=C) between 2 deg/s and 20 deg/s for a given retinal location. The relationship between the reciprocal of relative single glimpse probability of four subjects measured in this study and the mean detection times for comparable stimuli taken from Krendel and Wodinsky's Study (1960) appear to be linear and highly correlated (.92 to .99). Volume I of this report details the technical report and volume II contains the appendices.
A Comparison of Visual Fields with Fixed and Moving Fixation Points. Volume I
NASA Astrophysics Data System (ADS)
McLean, William E.
2002-09-01
Four procedures were used to measure the extent of the detection fields of four primary meridians of the binocular visual fields of four subjects. Procedure I (Moving Target) used a horizontally moving target and a stationary fixation point. Procedure II (Fixed Target) used a stationary target and a horizontally moving fixation point. Procedure III (Saccadic Move) used a saccadic eye movement between two stationary horizontal fixation points and a stationary target. Procedure IV (Flashed Target) used a stationary fixation point and a .6 second flashed target. The results from the dynamic procedures (I and II) and the two static procedures (III and IV) were very similar for each subject. In the dynamic procedures, the relationship between a change in contrast and an equivalent change in velocity tends to support Bloch's Law (IxT=C) between 2 deg/s and 20 deg/s for a given retinal location. The relationship between the reciprocal of relative single glimpse probability of four subjects measured in this study and the mean detection times for comparable stimuli taken from Krendel and Wodinsky's study (1960) appear to be linear and highly correlated (.92 to .99). Volume I of this report details the technical report and volume II contains the appendices.
Code of Federal Regulations, 2011 CFR
2011-10-01
...Operation of internal transmitter control systems through licensed fixed control...Control Internal Transmitter Control Systems § 90.473 Operation of internal transmitter control systems through licensed fixed...
Code of Federal Regulations, 2010 CFR
2010-10-01
...Operation of internal transmitter control systems through licensed fixed control...Control Internal Transmitter Control Systems § 90.473 Operation of internal transmitter control systems through licensed fixed...
NASA Astrophysics Data System (ADS)
Lampitt, Richard; Cristini, Luisa; Alexiou, Sofia
2015-04-01
The Fixed point Open Ocean Observatory network (FixO3, http://www.fixo3.eu/ ) integrates 23 European open ocean fixed point observatories and improves access to these infrastructures for the broader community. These provide multidisciplinary observations in all parts of the oceans from the air-sea interface to the deep seafloor. Started in September 2013 with a budget of 7 Million Euros over 4 years, the project has 29 partners drawn from academia, research institutions and SME's coordinated by the National Oceanography Centre, UK. Here we present the programme's achievements in the 18 months and the activities of the 12 Work Packages which have the objectives to: • integrate and harmonise the current procedures and processes • offer free access to observatory infrastructures to those who do not have such access, and free and open data services and products • innovate and enhance the current capability for multidisciplinary in situ ocean observation Open ocean observation is a high priority for European marine and maritime activities. FixO3 provides important data and services to address the Marine Strategy Framework Directive and in support of the European Integrated Maritime Policy. FixO3 provides a strong integrated framework of open ocean facilities in the Atlantic from the Arctic to the Antarctic and throughout the Mediterranean, enabling an integrated, regional and multidisciplinary approach to understand natural and anthropogenic change in the ocean.
Sensitivity of collective action to uncertainty about climate tipping points
NASA Astrophysics Data System (ADS)
Barrett, Scott; Dannenberg, Astrid
2014-01-01
Despite more than two decades of diplomatic effort, concentrations of greenhouse gases continue to trend upwards, creating the risk that we may someday cross a threshold for `dangerous' climate change. Although climate thresholds are very uncertain, new research is trying to devise `early warning signals' of an approaching tipping point. This research offers a tantalizing promise: whereas collective action fails when threshold uncertainty is large, reductions in this uncertainty may bring about the behavioural change needed to avert a climate `catastrophe'. Here we present the results of an experiment, rooted in a game-theoretic model, showing that behaviour differs markedly either side of a dividing line for threshold uncertainty. On one side of the dividing line, where threshold uncertainty is relatively large, free riding proves irresistible and trust illusive, making it virtually inevitable that the tipping point will be crossed. On the other side, where threshold uncertainty is small, the incentive to coordinate is strong and trust more robust, often leading the players to avoid crossing the tipping point. Our results show that uncertainty must be reduced to this `good' side of the dividing line to stimulate the behavioural shift needed to avoid `dangerous' climate change.
Kim, Do-Hyoung; Han, Mi-Ran; Lee, Gyunghee; Lee, Sang Soo; Kim, Young-Joon; Adams, Michael E.
2015-01-01
The ecdysis behavioral sequence in insects is a classic fixed action pattern (FAP) initiated by hormonal signaling. Ecdysis triggering hormones (ETHs) release the FAP through direct actions on the CNS. Here we present evidence implicating two groups of central ETH receptor (ETHR) neurons in scheduling the first two steps of the FAP: kinin (aka drosokinin, leucokinin) neurons regulate pre-ecdysis behavior and CAMB neurons (CCAP, AstCC, MIP, and Bursicon) initiate the switch to ecdysis behavior. Ablation of kinin neurons or altering levels of ETH receptor (ETHR) expression in these neurons modifies timing and intensity of pre-ecdysis behavior. Cell ablation or ETHR knockdown in CAMB neurons delays the switch to ecdysis, whereas overexpression of ETHR or expression of pertussis toxin in these neurons accelerates timing of the switch. Calcium dynamics in kinin neurons are temporally aligned with pre-ecdysis behavior, whereas activity of CAMB neurons coincides with the switch from pre-ecdysis to ecdysis behavior. Activation of CCAP or CAMB neurons through temperature-sensitive TRPM8 gating is sufficient to trigger ecdysis behavior. Our findings demonstrate that kinin and CAMB neurons are direct targets of ETH and play critical roles in scheduling successive behavioral steps in the ecdysis FAP. Moreover, temporal organization of the FAP is likely a function of ETH receptor density in target neurons. PMID:26401953
New Filling Technique and Performance Evaluations of the Cr3C2-C Peritectic Fixed Point
NASA Astrophysics Data System (ADS)
Sasajima, N.; Lowe, D.; Bai, C.; Yamada, Y.; Ara, C.
2011-12-01
The Cr3C2-C peritectic fixed point was investigated to test its capability to serve as a practical high-temperature fixed point. An improved filling technique where C/C sheet works as a wick and graphite paper as a hopper was applied successfully, and the long-term stability of the peritectic cell was evaluated by means of radiation thermometry. The repeatability of the melting point in one day was 7 mK with a melting range of approximately 100 mK. The cell was aged for 7 days, and the evaluated 56 melting temperatures during this period all fall within 90 mK, with a standard deviation of 19 mK. X-ray transmission photos showed that the ingot was filled uniformly in the crucible. After the evaluation of long-term stability, no clear degradation of the ingot shape and no leakage of molten metal were observed. From these results, it can be concluded that the Cr3C2-C peritectic cell has good stability and robustness, and the new filling technique was established. The impurity effect on the Cr3C2-C peritectic cell was also investigated by adding tungsten powder to another cell as the impurity component. After the observation of melting and freezing plateaux, the cell was cut in half to analyze the microstructure by means of electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS). The high concentration of impurity was observed in the area of the chromium-rich domain (eutectic mixture of Cr7C3 and Cr3C2), which suggests that impurities were rejected from the Cr3C2 peritectic phase during the peritectic freezing and were accumulated in the Cr7C3-Cr3C2 eutectic phase. This explains why the impurity effect is more severe for the Cr7C3-Cr3C2 eutectic point than for the Cr3C2-C peritectic point.
? I =1 /2 rule for kaon decays derived from QCD infrared fixed point
NASA Astrophysics Data System (ADS)
Crewther, R. J.; Tunstall, Lewis C.
2015-02-01
This article gives details of our proposal to replace ordinary chiral S U (3 )L×S U (3 )R perturbation theory ? PT3 by three-flavor chiral-scale perturbation theory ? PT? . In ? PT? , amplitudes are expanded at low energies and small u ,d ,s quark masses about an infrared fixed point ?IR of three-flavor QCD. At ?IR , the quark condensate ?q ¯ q ?vac?0 induces nine Nambu-Goldstone bosons: ? ,K ,? , and a 0++ QCD dilaton ? . Physically, ? appears as the f0(500 ) resonance, a pole at a complex mass with real part ? mK . The ? I =1 /2 rule for nonleptonic K decays is then a consequence of ? PT? , with a KS? coupling fixed by data for ? ? ?? ? and KS?? ? . We estimate RIR?5 for the nonperturbative Drell-Yan ratio R =? (e+e-?hadrons)/? (e+e-??+?-) at ?IR and show that, in the many-color limit, ? /f0 becomes a narrow q q ¯ state with planar-gluon corrections. Rules for the order of terms in ? PT? loop expansions are derived in Appendix A and extended in Appendix B to include inverse-power Li-Pagels singularities due to external operators. This relates to an observation that, for ? ? channels, partial conservation of the dilatation current is not equivalent to ? -pole dominance.
NASA Technical Reports Server (NTRS)
Shimada, Seiichi; Bock, Yehuda
1992-01-01
Results are presented from temporally dense measurements of crustal deformation associated with the convergence of the Eurasian (EUR), Pacific, North American, and Philippine Sea (PHS) plates, carried out in April 1988 by a 10-station GPS fixed-point network established in central Japan. Using regional orbit relaxation methods, the analysis of the first 17-month data revealed significant horizontal deformation across the Suruga trough. Namely, it was found that a site in the northern tip of PHS plate moved nearly westward with a velocity of 28 +/-5 mm per year, and a site at the southeastern tip of EUR plate moved south-southwestward with a velocity of 18 +/-5 mm per year. A significant vertical uplift with a velocity of 20 mm/yr was detected at a site inland of the Tokai district located in the Akaishi uplift zone and at a site on the Hatsushima Island in Sagami Bay.
Self-validating type C thermocouples to 2300 °C using high temperature fixed points
NASA Astrophysics Data System (ADS)
Pearce, J. V.; Elliott, C. J.; Machin, G.; Ongrai, O.
2013-09-01
Above 1500 °C, tungsten-rhenium (W-Re) thermocouples are the most commonly used contact thermometers because they are practical and inexpensive. However in general loss of calibration is very rapid, and, due to their embrittlement at high temperature, it is generally not possible to remove them for recalibration from the process environments in which they are used. Even if removal for recalibration was possible this would be of, at best, very limited use due to large inhomogeneity effects. Ideally, these thermocouples require some mechanism to monitor their drift in-situ. In this study, we describe self-validation of Type C (W5%Re/W26%Re) thermocouples by means of miniature high temperature fixed points comprising crucibles containing respectively Co-C, Pt-C, Ru-C, and Ir-C eutectic alloys. An overview of developments in this area is presented.
Miniature Co-C eutectic fixed-point cells for self-validating thermocouples
NASA Astrophysics Data System (ADS)
Ongrai, O.; Pearce, J. V.; Machin, G.; Sweeney, S. J.
2011-01-01
Miniature fixed-point cells have been constructed using ingots of Co-C eutectic alloy, with the aim of constructing self-validating thermocouples for in situ calibration. The design consists of a cylindrical graphite crucible, diameter 6 mm, containing the ingot, integrated into the measuring junction of a type R thermocouple. Two sizes of cell were studied, with internal volumes 124 and 64 mm3 respectively. A detailed study of the characteristics of the two designs shows a correlation between the emf at the melting temperature, and the furnace temperature. This correlation is dramatically reduced for the smaller cell. The correlation is characterized extensively. The smaller cell provides the best overall performance. The repeatability of both cells is of the order of 0.1 °C.
Point and Fixed Plot Sampling Inventory Estimates at the Savannah River Site, South Carolina.
Parresol, Bernard, R.
2004-02-01
This report provides calculation of systematic point sampling volume estimates for trees greater than or equal to 5 inches diameter breast height (dbh) and fixed radius plot volume estimates for trees < 5 inches dbh at the Savannah River Site (SRS), Aiken County, South Carolina. The inventory of 622 plots was started in March 1999 and completed in January 2002 (Figure 1). Estimates are given in cubic foot volume. The analyses are presented in a series of Tables and Figures. In addition, a preliminary analysis of fuel levels on the SRS is given, based on depth measurements of the duff and litter layers on the 622 inventory plots plus line transect samples of down coarse woody material. Potential standing live fuels are also included. The fuels analyses are presented in a series of tables.
A fast multi-level method for the fixed point form of matrix H-equations
Kelley, C.T. (North Carolina State Univ., Raleigh (United States)); Northrup, J.I. (Colby College, Waterville, ME (United States))
1993-01-01
In previous work quasi-Newton and multi-level algorithms for fully nonlinear integral equations were designed and analyzed. The motivating examples for that work were analogs of the Chandrasekhar H-equation for matrix-valued functions. A weakness of these algorithms was that transfer between grids was done with a piecewise linear interpolation instead of Nystroem interpolation. This choice of interpolation was used because the nonlinearity in the Chandrasekhar equation was expressed in the quadratic form for which a matrix inversion is not required. In this paper the fixed point formulation is reconsidered and a conditioning issue associated with the matrix is resolved. This allows use of Nystroem interpolation and thereby a more efficient multi-level method. Implementation details on the Alliant FX series of multiprocessor computers is also discussed. 18 refs., 3 tabs.
Fixed points, stability and intermittency in a shell model for advection of passive scalars
Julien Kockelkoren; Mogens H. Jensen
1999-11-23
We investigate the fixed points of a shell model for the turbulent advection of passive scalars introduced Jensen, Paladin and Vulpiani. The passive scalar field is driven by the velocity field of the popular GOY shell model. The scaling behavior of the static solutions is found to differ significantly from Obukhov-Corrsin scaling theta_n ~ k_n^(-1/3) which is only recovered in the limit where the diffusivity vanishes, D -> 0. From the eigenvalue spectrum we show that any perturbation in the scalar will always damp out, i.e. the eigenvalues of the scalar are negative and are decoupled from the eigenvalues of the velocity. Furthermore we estimate Lyapunov exponents and the intermittency parameters using a definition proposed by Benzi et al. The full model is as chaotic as the GOY model, measured by the maximal Lyapunov exponent, but is more intermittent.
NASA Astrophysics Data System (ADS)
Hoyos Velasco, Fredy Edimer; García, Nicolás Toro; Garcés Gómez, Yeison Alberto
In this paper, the output voltage of a buck power converter is controlled by means of a quasi-sliding scheme. The Fixed Point Inducting Control (FPIC) technique is used for the control design, based on the Zero Average Dynamics (ZAD) strategy, including load estimation by means of the Least Mean Squares (LMS) method. The control scheme is tested in a Rapid Control Prototyping (RCP) system based on Digital Signal Processing (DSP) for dSPACE platform. The closed loop system shows adequate performance. The experimental and simulation results match. The main contribution of this paper is to introduce the load estimator by means of LMS, to make ZAD and FPIC control feasible in load variation conditions. In addition, comparison results for controlled buck converter with SMC, PID and ZAD-FPIC control techniques are shown.
NASA Astrophysics Data System (ADS)
Luo, Jiaowan
2008-06-01
The fixed-point theory is first used to consider the stability for stochastic partial differential equations with delays. Some conditions for the exponential stability in pth mean as well as in sample path of mild solutions are given. These conditions do not require the monotone decreasing behavior of the delays, which is necessary in [T. Caraballo, K. Liu, Exponential stability of mild solutions of stochastic partial differential equations with delays, Stoch. Anal. Appl. 17 (1999) 743-763; Ruhollan Jahanipur, Stability of stochastic delay evolution equations with monotone nonlinearity, Stoch. Anal. Appl. 21 (2003) 161-181]. Even in this special case, our results also improve the results in [T. Caraballo, K. Liu, Exponential stability of mild solutions of stochastic partial differential equations with delays, Stoch. Anal. Appl. 17 (1999) 743-763].
Inflation: flow, fixed points and observables to arbitrary order in slow roll
William H. Kinney
2003-05-01
I generalize the inflationary flow equations of Hoffman and Turner to arbitrary order in slow roll. This makes it possible to study the predictions of slow roll inflation in the full observable parameter space of tensor/scalar ratio $r$, spectral index $n$, and running $d n / d \\ln k$. It also becomes possible to identify exact fixed points in the parameter flow. I numerically evaluate the flow equations to fifth order in slow roll for a set of randomly chosen initial conditions and find that the models cluster strongly in the observable parameter space, indicating a ``generic'' set of predictions for slow roll inflation. I comment briefly on the the interesting proposed correspondence between flow in inflationary parameter space and renormalization group flow in a boundary conformal field theory.
Progress report for the CCT-WG5 high temperature fixed point research plan
Machin, G.; Woolliams, E. R. [National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex,TW11 0LW (United Kingdom)] [National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex,TW11 0LW (United Kingdom); Anhalt, K. [Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin (Germany)] [Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin (Germany); Bloembergen, P. [National Institute of Metrology (NIM), Bei San Huan Dong Lu No. 18, Beijing, 100013 (China)] [National Institute of Metrology (NIM), Bei San Huan Dong Lu No. 18, Beijing, 100013 (China); Sadli, M. [Laboratoire Commun de Métrologie (LNE-Cnam), 61, rue du Landy, 93210 Saint-Denis, La Plaine (France)] [Laboratoire Commun de Métrologie (LNE-Cnam), 61, rue du Landy, 93210 Saint-Denis, La Plaine (France); Yamada, Y. [National Measurement Institute of Japan (NMIJ), AIST, Tsukuba, Ibaraki (Japan)] [National Measurement Institute of Japan (NMIJ), AIST, Tsukuba, Ibaraki (Japan)
2013-09-11
An overview of the progress in High Temperature Fixed Point (HTFP) research conducted under the auspices of the CCT-WG5 research plan is reported. In brief highlights are: Provisional long term stability of HTFPs has been demonstrated. Optimum construction methods for HTFPs have been established and high quality HTFPs of Co-C, Pt-C and Re-C have been constructed for thermodynamic temperature assignment. The major sources of uncertainty in the assignment of thermodynamic temperature have been identified and quantified. The status of absolute radiometric temperature measurement has been quantified through the circulation of a set of HTFPs. The measurement campaign to assign low uncertainty thermodynamic temperatures to a selected set of HTFPs will begin in mid-2012. It is envisaged that this will be complete by 2015 leading to HTFPs becoming routine reference standards for radiometry and high temperature metrology.
A Fast fixed-point Quantum Search Algorithm by using Disentanglement and Measurement
Mani, Ashish
2012-01-01
Generic quantum search algorithm searches for target entity in an unsorted database by repeatedly applying canonical Grover's quantum rotation transform to reach near the vicinity of the target entity. Thus, upon measurement, there is a high probability of finding the target entity. However, the number of times quantum rotation transform is to be applied for reaching near the vicinity of the target is a function of the number of target entities present in an unsorted database, which is generally unknown. A wrong estimate of the number of target entities can lead to overshooting or undershooting the targets, thus reducing the success probability. Some proposals have been made to overcome this limitation. These proposals either employ quantum counting to estimate the number of solutions or fixed-point schemes. This paper proposes a new scheme for stopping the application of quantum rotation transformation on reaching near the targets by disentanglement, measurement and subsequent processing to estimate the dist...
Optimization of SPRT measurements of freezing in a zinc fixed-point cell
NASA Astrophysics Data System (ADS)
Pearce, J. V.; Veltcheva, R. I.; Lowe, D. H.; Malik, Z.; Hunt, J. D.
2012-06-01
A numerical model of solute and heat transport in extremely pure materials is described. Its purpose is to characterize the effect of impurities on the freezing curves of metals containing impurities at the level of less than 1 part per million. It is used to simulate experiments performed using a commercially available zinc fixed-point cell for SPRT calibrations. The aim is to determine the effect of different vertical temperature gradients on the freezing curve and to find out whether a range of conditions could be determined where there was a good fit between theory and experiment. For this fixed-point cell, agreement between the model and experiment improves as the distribution coefficient k ? 0. It is found that the model only agrees with the measured freezing curves over the entire freeze for a narrow range of furnace settings where the temperature profile is most uniform. We suggest that this is because if the furnace settings are not optimized, the solid does not grow uniformly, and freezing may continue in regions remote from the SPRT after the material in the vicinity of the SPRT has finished freezing, so distorting the freezing curve. This effect is not present in the model and so the method presented here enables optimization of the furnace to ensure the SPRT is surrounded by a liquid-solid interface over the entire freezing range. We find that the optimum thermal environment is extremely sensitive to the furnace settings; the optimum thermal environment is found when the temperature is slightly cooler at the top of the cell, as measured in the re-entrant well of the cell. We note that optimizing the freezing process is a necessary step towards using a thermal analysis to correct for the effects of impurities in the sample.
Correlation Between Immersion Profile and Measured Value of Fixed-Point Temperature
NASA Astrophysics Data System (ADS)
Shulgat, O. S.; Fuksov, V. M.; Ivanova, A. G.; Gerasimov, S. F.; Pokhodun, A. I.
2014-04-01
Assessment of thermal immersion effects in the melting and freezing points defined by the International Temperature Scale of 1990 is one of the vital issues of modern thermometry. In documents of the Consultative Committee for Thermometry, the deviation of the experimental immersion profile from the theoretical value of the hydrostatic effect at a height of about 3 cm to 5 cm from the thermometer well bottom is used for the estimation of the uncertainty due to unwanted thermal effects. This estimation assumes the occurrence of solely the hydrostatic effect all along the height of the well inner wall. Real distortions of the temperature gradient at the bottom and at the top part of the well caused by the change of heat-exchange conditions are not taken into account. To define more precisely the temperature gradient along the height of the well, a miniature PRT with a 30 mm sensitive element and a sheath length and diameter of about 60 mm and 6 mm, respectively, were used. Also, the measurements of fixed-points temperature at noticeably different slopes of immersion profiles due to variations of the thermometer heat exchange and phase transition realization conditions were produced by means of a standard platinum resistance thermometer (SPRT). The measurements were carried out at the tin and zinc freezing points. The immersion curves measured with a miniature thermometer demonstrated an increase of the temperature during its lifting in the first 1 cm to 3 cm above the bottom of the well. The measurement results at the zinc freezing point by means of the SPRT have not confirmed the correlation between the immersion curves, the received value of the Zn freezing temperature, and the estimation of its uncertainty.
Bilateral comparison of tin fixed point cells between INMETRO and NPL
NASA Astrophysics Data System (ADS)
Silva, R. da; Veltcheva, R. I.; Gray, J.; Pearce, J. V.; Machin, G.; Teixeira, R. N.
2013-09-01
In April 2011, a bilateral comparison of tin fixed point cells (231.928 °C) took place at the facilities of the Temperature group at the National Physical Laboratory (NPL). The comparison was with a standard from the Thermal Metrology Division of the National Institute of Metrology, Quality and Technology (INMETRO). It involved two cells: the test cell was an open one constructed in late 2010 at the INMETRO Thermometry Laboratory as part of an MSc research project; the reference cell was a sealed one, constructed in 2000 at NPL, traceable to the UK national standard tin point. The materials employed in the construction of the cells were from different suppliers. The cell design, dimensions and construction procedures were also different. Three standard platinum resistance thermometers (SPRTs), each different models from different manufacturers, were used to undertake the comparison, one from INMETRO and two from NPL. The comparison was performed in quadruplicate, each combination using a different freezing plateau. The differing self-heating behaviour of the different SPRTs was taken into account. The methodology employed in this comparison is detailed in the present paper.
Investigation of the Behavior of the Co C Eutectic Fixed Point
NASA Astrophysics Data System (ADS)
Girard, F.; Battuello, M.; Florio, M.
2007-12-01
The behavior of the Co C eutectic fixed point was investigated at INRIM. Several cells of different design and volume, and filled with cobalt of different purity were constructed and investigated with both Pt/Pd thermocouples and radiation thermometers. The melting behavior was investigated with respect to the melting rate, the pre-freezing rate, and the annealing time. The melting temperatures, as defined, were not significantly affected by the different testing conditions, even if the shape and duration of the plateaux were influenced. Several tens of melt and freeze cycles were performed with the different cells. The spread in the results for all of the different conditions was very limited in extent, giving rise to a standard deviation of less than 0.04 °C; a repeatability of better than 0.02 °C was found with both Pt/Pd thermocouples and radiation thermometers. The results of our measurements are encouraging and confirm the suitability of Co C as a reference point for the high-temperature range in a possible future temperature scale. Investigations of long-term stability remain ongoing.
NASA Astrophysics Data System (ADS)
Hao, X.; Yuan, Z.; Wang, J.; Lu, X.
2013-09-01
In this paper, we describe an InGaAs detector based radiation thermometer (IRT) and new design of fixed-point blackbodies, including Sn, Zn, Al and Cu, for the establishment of a temperature scale from 200 °C to 1085 °C at the National Institute of Metrology of China. The construction and calibration of the IRT with the four fixed-point blackbodies are described. Characteristics of the IRT, such as the size-of-source effect, the amplifier performance and its stability are determined. The design of the four fixed-points, with 10 mm diameter of aperture and 0.9999 emissivity, is described. The uncertainty of the scale realization is elaborated.
Hao, X.; Yuan, Z.; Wang, J.; Lu, X. [Division of Thermometry and Materials Evaluation, National Institute of Metrology, Beijing, China, 100013 (China)] [Division of Thermometry and Materials Evaluation, National Institute of Metrology, Beijing, China, 100013 (China)
2013-09-11
In this paper, we describe an InGaAs detector based radiation thermometer (IRT) and new design of fixed-point blackbodies, including Sn, Zn, Al and Cu, for the establishment of a temperature scale from 200 °C to 1085 °C at the National Institute of Metrology of China. The construction and calibration of the IRT with the four fixed-point blackbodies are described. Characteristics of the IRT, such as the size-of-source effect, the amplifier performance and its stability are determined. The design of the four fixed-points, with 10 mm diameter of aperture and 0.9999 emissivity, is described. The uncertainty of the scale realization is elaborated.
Assessment of tungsten/rhenium thermocouples with metal-carbon eutectic fixed points up to 1500°C
Gotoh, M.
2013-09-11
Four Type A thermocouples and two Type C thermocouples were calibrated at the Au fixed point and Co-C and Pd-C eutectic fixed points. The thermocouples were exposed to 1330 °C for a total of 100 hours. The maximum drift due to the exposure was found to be 4.8 °C. The fixed-point calibration EMF of these thermocouples deviated by less than 0.86% from the temperature specified by the standards ASTM E230-2003 for Type C and GOSTR 8.585-2001 for Type A. The length of one of Type A thermocouples A52 is longer than the others by 150mm. Making use of this provision it was possible to place annealed part of A52 to the temperature gradient part of calibration arrangement every time. Therefore observed aging effect was as low as 0.5 °C compared to the other thermocouples.
Assessment of tungsten/rhenium thermocouples with metal-carbon eutectic fixed points up to 1500°C
NASA Astrophysics Data System (ADS)
Gotoh, M.
2013-09-01
Four Type A thermocouples and two Type C thermocouples were calibrated at the Au fixed point and Co-C and Pd-C eutectic fixed points. The thermocouples were exposed to 1330 °C for a total of 100 hours. The maximum drift due to the exposure was found to be 4.8 °C. The fixed-point calibration EMF of these thermocouples deviated by less than 0.86% from the temperature specified by the standards ASTM E230-2003 for Type C and GOSTR 8.585-2001 for Type A. The length of one of Type A thermocouples A52 is longer than the others by 150mm. Making use of this provision it was possible to place annealed part of A52 to the temperature gradient part of calibration arrangement every time. Therefore observed aging effect was as low as 0.5 °C compared to the other thermocouples.
Development of High-Temperature Fixed Points of Unknown Temperature Suitable for Key Comparisons
NASA Astrophysics Data System (ADS)
Teixeira, R.; Machin, G.; Orlando, A.
2014-04-01
During the last key comparison of local realizations of the International Temperature Scale of 1990 above the silver point, which used high stability tungsten strip lamps, it became clear that these artifacts can no longer be used to evaluate the real calibration and measuring capabilities (CMCs) of the participant laboratories. The intrinsic uncertainty of the lamps is actually larger than the claimed CMCs of most national laboratories. Ideally a set of driftless robust artifacts, preferably of unknown temperature, should be used for this purpose, as this would allow CMCs to be probed at the highest level. Currently such artifacts do not exist. High-temperature fixed points (HTFPs) have been the subject of intense study for more than 10 years. The research has come to an advanced state so much that the temperatures of some of them are well known to be within 1 K. This has rendered their use as comparison artifacts questionable as any comparison would not be blind. To address this issue, doped HTFPs have been developed which have had their transition temperature altered from that of the eutectic composition. Two Ni-C-Cu cells and two Ni-C-Sn were constructed by Inmetro with different quantities of Cu and Sn, respectively. These were compared to a reference Ni-C cell (nominal transition temperature of 1329 C) and the temperature differences from the pure state determined. In this paper the design, construction, and results of long-term stability are described. These promising results indicate that it is possible to make HTFPs with altered temperatures which are stable enough to serve as comparison artifacts.
Chiampi, M.; Repetto, M. [Politecnico di Torino (Italy). Dipt. di Ingegneria Elettrica Industriale] [Politecnico di Torino (Italy). Dipt. di Ingegneria Elettrica Industriale; Chiarabaglio, D. [Istituto Elettrotecnico Nazionale Galileo Ferraris, Torino (Italy)] [Istituto Elettrotecnico Nazionale Galileo Ferraris, Torino (Italy)
1995-11-01
The hysteresis phenomenon can significantly affect the behavior of magnetic cores in electrical machines and devices. This paper presents a finite element solution of periodic steady state magnetic field problems in soft materials with scalar hysteresis. The Jiles-Atherton model is employed for the generation of symmetric B-H loops and it is coupled with the Fixed Point Technique for handling magnetic nonlinearities. The proposed procedure is applied to a hysteretic model problem whose analytical solution is available. The results show that the Fixed Point Technique can efficiently deal with non-single valued material characteristics under periodic operating conditions.
NASA Astrophysics Data System (ADS)
Piñeiro Orioli, Asier; Boguslavski, Kirill; Berges, Jürgen
2015-07-01
We investigate universal behavior of isolated many-body systems far from equilibrium, which is relevant for a wide range of applications from ultracold quantum gases to high-energy particle physics. The universality is based on the existence of nonthermal fixed points, which represent nonequilibrium attractor solutions with self-similar scaling behavior. The corresponding dynamic universality classes turn out to be remarkably large, encompassing both relativistic as well as nonrelativistic quantum and classical systems. For the examples of nonrelativistic (Gross-Pitaevskii) and relativistic scalar field theory with quartic self-interactions, we demonstrate that infrared scaling exponents as well as scaling functions agree. We perform two independent nonperturbative calculations, first by using classical-statistical lattice simulation techniques and second by applying a vertex-resummed kinetic theory. The latter extends kinetic descriptions to the nonperturbative regime of overoccupied modes. Our results open new perspectives to learn from experiments with cold atoms aspects about the dynamics during the early stages of our universe.
NASA Astrophysics Data System (ADS)
Mishra, Puneet; Singla, Sunil Kumar
2013-01-01
In the modern world of automation, biological signals, especially Electroencephalogram (EEG) and Electrocardiogram (ECG), are gaining wide attention as a source of biometric information. Earlier studies have shown that EEG and ECG show versatility with individuals and every individual has distinct EEG and ECG spectrum. EEG (which can be recorded from the scalp due to the effect of millions of neurons) may contain noise signals such as eye blink, eye movement, muscular movement, line noise, etc. Similarly, ECG may contain artifact like line noise, tremor artifacts, baseline wandering, etc. These noise signals are required to be separated from the EEG and ECG signals to obtain the accurate results. This paper proposes a technique for the removal of eye blink artifact from EEG and ECG signal using fixed point or FastICA algorithm of Independent Component Analysis (ICA). For validation, FastICA algorithm has been applied to synthetic signal prepared by adding random noise to the Electrocardiogram (ECG) signal. FastICA algorithm separates the signal into two independent components, i.e. ECG pure and artifact signal. Similarly, the same algorithm has been applied to remove the artifacts (Electrooculogram or eye blink) from the EEG signal.
A miniature high-temperature fixed point for self-validation of type C thermocouples
NASA Astrophysics Data System (ADS)
Ongrai, O.; Pearce, J. V.; Machin, G.; Sweeney, S. J.
2011-10-01
Reliable high-temperature (>1500 °C) measurement is crucial for a wide range of industrial processes as well as specialized applications, e.g. aerospace. The most common type of sensor used for high-temperature measurement is the thermocouple. At and above 1500 °C, tungsten-rhenium (W-Re) thermocouples are the most commonly used temperature sensors due to their utility up to 2300 °C. However, the achievable accuracy of W-Re thermocouples is seriously limited by the effects of their inhomogeneity, drift and hysteresis. Furthermore, due to their embrittlement at high temperature, the removal of these thermocouples from environments such as nuclear power plants or materials processing furnaces for recalibration is generally not possible. Even if removal for recalibration were possible, this would be of, at best, very limited use due to large inhomogeneity effects. Ideally, these thermocouples require some mechanism to monitor their drift in situ. In this study, we describe a miniature Co-C eutectic fixed-point cell to evaluate the stability of type C (W5%Re/W26%Re) thermocouples by means of in situ calibration.
Realization of the WC-C peritectic fixed point at NIM and NMIJ
Wang, T.; Bai, C.; Yuan, Z.; Dong, W.; Lu, X. [National Institute of Metrology (NIM), Beijing (China)] [National Institute of Metrology (NIM), Beijing (China); Sasajima, N.; Yamada, Y.; Ara, C. [National Metrology Institute of Japan, AIST (NMIJ, AIST), Tsukuba (Japan)] [National Metrology Institute of Japan, AIST (NMIJ, AIST), Tsukuba (Japan)
2013-09-11
Three WC-C peritectic fixed point cells, constructed from different sources of tungsten with different nominal purities, were measured at NIM and NMIJ. The three cells were constructed at NMIJ by NIM and NMIJ staffs, and T{sub 90} values of the three cells were measured at NMIJ during the period 31 Aug. to 25 Dec. 2009. Thereafter, the three cells were then transported to NIM, and T{sub 90} values of these cells were measured from 7 Dec. 2011 to 9 Jan. 2012. The results showed that T{sub 90} values of the three cells measured at the two institutes agreed within 0.4 °C with the combined scale comparison uncertainty of 1.7 °C (k= 2). The main component of the uncertainty is not the uncertainty due to impurities of the cells but the scale uncertainty and the stability of the measurement system. From these results it can be concluded that the WC-C cell is stable enough to provide new means of international high-temperature scale comparison above 3000 K.
NASA Astrophysics Data System (ADS)
Yokoyama, Yoshiaki; Kim, Minseok; Arai, Hiroyuki
At present, when using space-time processing techniques with multiple antennas for mobile radio communication, real-time weight adaptation is necessary. Due to the progress of integrated circuit technology, dedicated processor implementation with ASIC or FPGA can be employed to implement various wireless applications. This paper presents a resource and performance evaluation of the QRD-RLS systolic array processor based on fixed-point CORDIC algorithm with FPGA. In this paper, to save hardware resources, we propose the shared architecture of a complex CORDIC processor. The required precision of internal calculation, the circuit area for the number of antenna elements and wordlength, and the processing speed will be evaluated. The resource estimation provides a possible processor configuration with a current FPGA on the market. Computer simulations assuming a fading channel will show a fast convergence property with a finite number of training symbols. The proposed architecture has also been implemented and its operation was verified by beamforming evaluation through a radio propagation experiment.
Fixed points, stability, and intermittency in a shell model for advection of passive scalars
Kockelkoren; Jensen
2000-08-01
We investigate the fixed points of a shell model for the turbulent advection of passive scalars introduced in Jensen, Paladin, and Vulpiani [Phys. Rev. A 45, 7214 (1992)]. The passive scalar field is driven by the velocity field of the popular Gledzer-Ohkitani-Yamada (GOY) shell model. The scaling behavior of the static solutions is found to differ significantly from Obukhov-Corrsin scaling straight theta(n) approximately k(-1/3)(n), which is only recovered in the limit where the diffusivity vanishes, D-->0. From the eigenvalue spectrum we show that any perturbation in the scalar will always damp out, i.e., the eigenvalues of the scalar are negative and are decoupled from the eigenvalues of the velocity. We estimate Lyapunov exponents and the intermittency parameters using a definition proposed by Benzi, Paladin, Parisi, and Vulpiani [J. Phys. A 18, 2157 (1985)]. The full model is found to be as chaotic as the GOY model, measured by the maximal Lyapunov exponent, but is more intermittent. PMID:11088685
Fixed points, stability, and intermittency in a shell model for advection of passive scalars
NASA Astrophysics Data System (ADS)
Kockelkoren, Julien; Jensen, Mogens H.
2000-08-01
We investigate the fixed points of a shell model for the turbulent advection of passive scalars introduced in Jensen, Paladin, and Vulpiani [Phys. Rev. A 45, 7214 (1992)]. The passive scalar field is driven by the velocity field of the popular Gledzer-Ohkitani-Yamada (GOY) shell model. The scaling behavior of the static solutions is found to differ significantly from Obukhov-Corrsin scaling ?n~k-1/3n, which is only recovered in the limit where the diffusivity vanishes, D-->0. From the eigenvalue spectrum we show that any perturbation in the scalar will always damp out, i.e., the eigenvalues of the scalar are negative and are decoupled from the eigenvalues of the velocity. We estimate Lyapunov exponents and the intermittency parameters using a definition proposed by Benzi, Paladin, Parisi, and Vulpiani [J. Phys. A 18, 2157 (1985)]. The full model is found to be as chaotic as the GOY model, measured by the maximal Lyapunov exponent, but is more intermittent.
NASA Astrophysics Data System (ADS)
Fahr, M.; Cundy, D. S.
2015-08-01
Impurities are still among the primary concerns regarding the realization of many fixed points of the International Temperature Scale (ITS-90). Several methods have been suggested to correct for these effects. The most promising strategy, with regard to the achievable uncertainty level, is the `sum of the individual estimates' (SIE) method. It involves a chemical analysis of the material and a calculation of each of the detected chemical species' effect on the phase-transition temperature of the fixed-point substance. This correction can be accurate only if all the detected impurities are completely dissolved. Given the recent evidence for insoluble impurities in metal fixed points, this strategy needs to be modified; otherwise, it may lead to an inaccurate estimation of the impurity-related effect on the fixed-point temperature. In this article, a correction method is set out that reflects the crucial distinction between soluble, insoluble, and partially soluble impurities. This `sum of the individual estimates for the dissolved species' (SIEDS) method starts from a chemical analysis but takes into account only the dissolved particles. For this purpose, different types of substances are considered as possible dissolved impurities and are discussed from a chemical point of view. For those impurities where data are insufficient, only an uncertainty estimation is possible. For this purpose, the `overall maximum estimate of the dissolved species' (OMEDS) method is derived from the SIEDS method as the new counterpart to the well-known `overall maximum estimate' (OME) method.
NASA Astrophysics Data System (ADS)
Kwon, Su Yong; Kim, Yong-Gyoo; Yang, Inseok
2010-06-01
We have measured the heat flux accompanying the melting or freezing of metal (or metalloid)-carbon eutectics, using differential scanning calorimetry (DSC) to identify appropriate binary systems for secondary thermometry fixed points. Well-known alloy systems such as Fe-C and Ni-C showed reproducible endothermic and exothermic peaks that represent melting and freezing reactions in the DSC measurement. Furthermore, a new Si-C system with a eutectic composition showed reproducible melting and freezing peaks in the DSC measurements. Based on the results by DSC, we identified the Si-SiC eutectic point as a possible eutectic fixed point. To confirm this possibility, we made a Si-SiC cell for thermocouple thermometry and measured its melting and freezing characteristics using a Pt/Pd thermocouple. The melting temperature of the Si-SiC eutectic was reproducible to within 0.02 °C (one standard deviation). From the results, we found that Si-SiC has possibility as a new eutectic fixed point at temperatures around 1400 °C. We also concluded that DSC analysis could be used to measure the reproducibility of freezing and melting reactions that are to be used as fixed points for thermometry, because it is a rapid and easy-to-use tool for characterizing the thermal behaviour of materials with only a small sample.
NASA Astrophysics Data System (ADS)
Edler, F.; Baratto, A. C.
2005-08-01
A vertical cobalt-carbon (Co-C) eutectic fixed point cell was constructed at PTB to demonstrate its use for improvement of the calibration of noble-metal thermocouples at temperatures above 1100 °C. The melting and freezing temperatures of the Co-C eutectic were measured in different high-temperature furnaces at PTB and INMETRO (Brazil) to show its stability by using a Pt/Pd thermocouple. The reproducibility of all measured electromotive forces at the inflection points of the melting curves amounts to a value of about 0.06 °C. No drift in the melting temperature was observed. Therefore, the Co-C eutectic fixed point cell can be used as an adequate transfer standard for dissemination of the International Temperature Scale of 1990 (ITS-90) in the temperature range above the freezing point of copper.
Infrared Fixed Point in the Strong Running Coupling: Unraveling the ?I = 1/2 Puzzle in K-Decays
NASA Astrophysics Data System (ADS)
Crewther, R. J.; Tunstall, Lewis C.
2013-08-01
In this paper, we present an explanation for the ?I = 1/2 rule in K-decays based on the premise of an infrared fixed point ?IR in the running coupling ?s of quantum chromodynamics (QCD) for three light quarks u, d, s. At the fixed point, the quark condensate <\\bar {q}q> vac !=q 0 spontaneously breaks scale and chiral SU(3)L×SU(3)R symmetry. Consequently, the low-lying spectrum contains nine Nambu-Goldstone bosons: ?, K, ? and a QCD dilaton ?. We identify ? as the f0(500) resonance and construct a chiral-scale perturbation theory ?PT? for low-energy amplitudes expanded in ?s about ?IR. The ?I = 1/2 rule emerges in the leading order of ?PT? through a ?-pole term KS?????, with a gKS? coupling fixed by data on ????0?0 and KS???. We also determine RIR ?5 for the nonperturbative Drell-Yan ratio at ?IR.
Huang, Na
2014-01-01
We present a fixed-point iterative method for solving systems of nonlinear equations. The convergence theorem of the proposed method is proved under suitable conditions. In addition, some numerical results are also reported in the paper, which confirm the good theoretical properties of our approach. PMID:24795537
Kumar, Anurag
Fixed Point Analysis of Single Cell IEEE 802.11e WLANs: Uniqueness, Multistability and Throughput Differentiation Venkatesh Ramaiyan ECE Department Indian Institute of Science Bangalore, India rvenkat@ece.iisc.ernet.in Anurag Kumar ECE Department Indian Institute of Science Bangalore, India anurag@ece.iisc.ernet.in Eitan
A LOW-POWER, FIXED-POINT, FRONT-END FEATURE EXTRACTION FOR A DISTRIBUTED SPEECH RECOGNITION SYSTEM
Simunic, Tajana
A LOW-POWER, FIXED-POINT, FRONT-END FEATURE EXTRACTION FOR A DISTRIBUTED SPEECH RECOGNITION SYSTEM of a signal processing front- end for a distributed speech recognition system with the goal of reducing power and voltages for further reductions in power consumption. This technique, known as dynamic voltage scaling
NASA Astrophysics Data System (ADS)
Pereira, Emmanuel A.
1993-12-01
The domain of attraction is determined in a small neigborhood of the tridimensional massless Gaussian fixed point, obtaining a critical surface in a manifold with one marginal and two relevant directions (besides the marginal direction due to the field strengh renormalization). The results are proven within the context of a hierarchical approximation.
Analysis of gene network robustness based on saturated fixed point attractors
2014-01-01
The analysis of gene network robustness to noise and mutation is important for fundamental and practical reasons. Robustness refers to the stability of the equilibrium expression state of a gene network to variations of the initial expression state and network topology. Numerical simulation of these variations is commonly used for the assessment of robustness. Since there exists a great number of possible gene network topologies and initial states, even millions of simulations may be still too small to give reliable results. When the initial and equilibrium expression states are restricted to being saturated (i.e., their elements can only take values 1 or ?1 corresponding to maximum activation and maximum repression of genes), an analytical gene network robustness assessment is possible. We present this analytical treatment based on determination of the saturated fixed point attractors for sigmoidal function models. The analysis can determine (a) for a given network, which and how many saturated equilibrium states exist and which and how many saturated initial states converge to each of these saturated equilibrium states and (b) for a given saturated equilibrium state or a given pair of saturated equilibrium and initial states, which and how many gene networks, referred to as viable, share this saturated equilibrium state or the pair of saturated equilibrium and initial states. We also show that the viable networks sharing a given saturated equilibrium state must follow certain patterns. These capabilities of the analytical treatment make it possible to properly define and accurately determine robustness to noise and mutation for gene networks. Previous network research conclusions drawn from performing millions of simulations follow directly from the results of our analytical treatment. Furthermore, the analytical results provide criteria for the identification of model validity and suggest modified models of gene network dynamics. The yeast cell-cycle network is used as an illustration of the practical application of this analytical treatment. PMID:24650364
NASA Astrophysics Data System (ADS)
Castro, P.; Machin, G.; Bloembergen, P.; Lowe, D.; Whittam, A.
2014-07-01
This study forms part of the European Metrology Research Programme project implementing the New Kelvin to assign thermodynamic temperatures to a selected set of high-temperature fixed points (HTFPs), Cu, Co-C, Pt-C, and Re-C. A realistic thermal model of these HTFPs, developed in finite volume software ANSYS FLUENT, was constructed to quantify the uncertainty associated with the temperature drop across the back wall of the cell. In addition, the widely applied software package, STEEP3 was used to investigate the influence of cell emissivity. The temperature drop, , relates to the temperature difference due to the net loss of heat from the aperture of the cavity between the back wall of the cavity, viewed by the thermometer, defining the radiance temperature, and the solid-liquid interface of the alloy, defining the transition temperature of the HTFP. The actual value of can be used either as a correction (with associated uncertainty) to thermodynamic temperature evaluations of HTFPs, or as an uncertainty contribution to the overall estimated uncertainty. In addition, the effect of a range of furnace temperature profiles on the temperature drop was calculated and found to be negligible for Cu, Co-C, and Pt-C and small only for Re-C. The effective isothermal emissivity is calculated over the wavelength range from 450 nm to 850 nm for different assumed values of surface emissivity. Even when furnace temperature profiles are taken into account, the estimated emissivities change only slightly from the effective isothermal emissivity of the bare cell. These emissivity calculations are used to estimate the uncertainty in the temperature assignment due to the uncertainty in the emissivity of the blackbody.
Mehta, Dhagash, E-mail: dbmehta@syr.edu [Department of Physics, Syracuse University, Syracuse, NY 13244 (United States); Kastner, Michael, E-mail: kastner@sun.ac.za [National Institute for Theoretical Physics (NITheP), Stellenbosch 7600 (South Africa); Institute of Theoretical Physics, University of Stellenbosch, Stellenbosch 7600 (South Africa)
2011-06-15
Research Highlights: > Exact results for all stationary points of some high-dimensional function are given. > They are interpreted as Gribov copies of a lattice Landau gauge fixing functional. > The Gribov ambiguity and the Neuberger problem in compact U(1) are illustrated. > Stationary points are used to discuss a criterion on the absence of phase transitions. - Abstract: We study the stationary points of what is known as the lattice Landau gauge fixing functional in one-dimensional compact U(1) lattice gauge theory, or as the Hamiltonian of the one-dimensional random phase XY model in statistical physics. An analytic solution of all stationary points is derived for lattices with an odd number of lattice sites and periodic boundary conditions. In the context of lattice gauge theory, these stationary points and their indices are used to compute the gauge fixing partition function, making reference in particular to the Neuberger problem. Interpreted as stationary points of the one-dimensional XY Hamiltonian, the solutions and their Hessian determinants allow us to evaluate a criterion which makes predictions on the existence of phase transitions and the corresponding critical energies in the thermodynamic limit.
Beguin, Francois; Calvez, Patrice Le; Miernowski, Tomasz
2011-01-01
We prove the existence of common fixed points for commuting homeomorphisms of the plane R^2 or the sphere S^2, which preserve a probability measure. For example: some commuting C^1-diffeomorphisms of S^2, which are sufficiently close to the identity and preserve a probability measure whose support is not a single point, have at least two common fixed points.
Sumit Mohinta; T. K. Samanta
2011-04-16
None has studied the well-posedness of common fixed points in fuzzy metric space. In this paper, our target is to develop the well-posedness of common fixed points in fuzzy metric space. Also using weakly compatibility, implicit relation, property (E.A.) and strict contractive conditions, we have established the unique common fixed point for three self mappings and also for four self mappings in fuzzy metric space.
NASA Astrophysics Data System (ADS)
Edler, F.; Zheng, W.
2011-10-01
An interlaboratory comparison of the melting temperatures of three palladium-carbon (Pd-C) eutectic fixed-point cells of different designs and usable for the calibration of thermocouples was performed at NIM. Two Pt/Pd thermocouples were constructed for this particular purpose. One of the Pd-C eutectic cells is of conventional design and size; the two other cells are miniature fixed-point cells of different designs. The melting temperature of the conventional cell, PdC1-NIM, was slightly higher than the melting temperatures of the miniature cells by about 160 mK (PdCM2 of PTB) and 290 mK (PdC2-NIM). The melting temperatures of the two miniature Pd-C cells agree within their measurement uncertainties for k = 2 of about 135 mK. Furthermore, a new aspect of leakage effects often observed in the use of Pd-C cells is presented.
Wiese, Kay Jörg
. Proposed field theories are unconventional and harder to control than those for pure critical systems of nonanalytic functions, perturbative control was recovered to one-loop order [i.e., to O 4 ÿ d] and fixed be avoided. This Letter presents a new level of ``smoking gun'' tests of the FRG for manifolds, by directly
A fixed point in Coptic Chronology: the solar eclipse of 10 March, 601
John Ray; Gerry Gilmore
2006-07-22
We reconsider the description of a solar eclipse in the Coptic ostracon in the Egyptian museum, Turin, confirming its identification with the solar eclipse of 10 march 601. This provides one of very few fixed dates in Coptic chronology. We comment on the rarity of such descriptions.
Fixed-Radius Point Counts in Forests: Factors Influencing Effectiveness and Efficiency1
, as compared to residents. A greater number of stations are probably necessary when using fixed-radius compared, Office of Migratory Bird Management, 4401 North Fairfax Drive, Arlington, VA 22203, and Smithsonian, Intermountain Research Station, USDA Forest Service, 316 E. Myrtle St., Boise, Idaho 83702; and Assistant Leader
Complex Systems-Exercises 2 1. Find all fixed points of F : R R with F(x) = x3
Edalat, Abbas
Complex Systems- Exercises 2 1. Find all fixed points of F : R R with F(x) = x3 - 2x and determine their nature. Show that F has a period orbit {1, -1} of period 2. What is the type of this periodic orbit? 2. Find the explicit form of (i) the maps f1, f2, f3 in the generation of the Sierpinky triangle, and (ii
Berridge, Kent C; Aldridge, J Wayne; Houchard, Kimberly R; Zhuang, Xiaoxi
2005-01-01
Background Excessive sequential stereotypy of behavioral patterns (sequential super-stereotypy) in Tourette's syndrome and obsessive compulsive disorder (OCD) is thought to involve dysfunction in nigrostriatal dopamine systems. In sequential super-stereotypy, patients become trapped in overly rigid sequential patterns of action, language, or thought. Some instinctive behavioral patterns of animals, such as the syntactic grooming chain pattern of rodents, have sufficiently complex and stereotyped serial structure to detect potential production of overly-rigid sequential patterns. A syntactic grooming chain is a fixed action pattern that serially links up to 25 grooming movements into 4 predictable phases that follow 1 syntactic rule. New mutant mouse models allow gene-based manipulation of brain function relevant to sequential patterns, but no current animal model of spontaneous OCD-like behaviors has so far been reported to exhibit sequential super-stereotypy in the sense of a whole complex serial pattern that becomes stronger and excessively rigid. Here we used a hyper-dopaminergic mutant mouse to examine whether an OCD-like behavioral sequence in animals shows sequential super-stereotypy. Knockdown mutation of the dopamine transporter gene (DAT) causes extracellular dopamine levels in the neostriatum of these adult mutant mice to rise to 170% of wild-type control levels. Results We found that the serial pattern of this instinctive behavioral sequence becomes strengthened as an entire entity in hyper-dopaminergic mutants, and more resistant to interruption. Hyper-dopaminergic mutant mice have stronger and more rigid syntactic grooming chain patterns than wild-type control mice. Mutants showed sequential super-stereotypy in the sense of having more stereotyped and predictable syntactic grooming sequences, and were also more likely to resist disruption of the pattern en route, by returning after a disruption to complete the pattern from the appropriate point in the sequence. By contrast, wild-type mice exhibited weaker forms of the fixed action pattern, and often failed to complete the full sequence. Conclusions Sequential super-stereotypy occurs in the complex fixed action patterns of hyper-dopaminergic mutant mice. Elucidation of the basis for sequential super-stereotypy of instinctive behavior in DAT knockdown mutant mice may offer insights into neural mechanisms of overly-rigid sequences of action or thought in human patients with disorders such as Tourette's or OCD. PMID:15710042
NASA Astrophysics Data System (ADS)
Sadli, Mohamed; Bourson, Frédéric; Diril, Ahmet; Journeau, Christophe; Lowe, Dave; Parga, Clemente
2014-08-01
Among the activities of the European Metrology Research Programme (EMRP) project HiTeMS one work package is devoted to the development and testing of industrial solutions for long-standing temperature measurement problems at the highest temperatures. LNE-Cnam, NPL, TUBITAK-UME have worked on the design of high temperature fixed points (HTFP) suitable for in-situ temperature monitoring to be implemented in the facilities of CEA (Commissariat à l'énergie atomique et aux énergies alternatives). Several high temperature fixed point cells were constructed in these three national metrology institutes (NMIs) using a rugged version of cells based on the hybrid design of the laboratory HTFP developed and continuously improved at LNE-Cnam during the last years. The fixed points of interest were Co-C, Ru-C and Re-C corresponding to melting temperatures of 1324 °C, 1953 °C and 2474 °C respectively. The cells were characterised at the NMIs after their construction. Having proved robust enough, they were transported to CEA and tested in an induction furnace and cycled from room temperature to temperatures much above the melting temperatures (> +400 °C) with extremely high heating and cooling rates (up to 10 000 K/h). All the cells withstood the tests and the melting plateaus could be observed in all cases.
Walking near a Conformal Fixed Point: the 2-d O(3) Model at theta near pi as a Test Case
Philippe de Forcrand; Michele Pepe; Uwe-Jens Wiese
2012-04-22
Slowly walking technicolor models provide a mechanism for electroweak symmetry breaking whose nonperturbative lattice investigation is rather challenging. Here we demonstrate walking near a conformal fixed point considering the 2-d lattice O(3) model at vacuum angle $\\theta \\approx \\pi$. The essential features of walking technicolor models are shared by this toy model and can be accurately investigated by numerical simulations. We show results for the running coupling and the beta-function and we perform a finite size scaling analysis of the massgap close to the conformal point.
NASA Astrophysics Data System (ADS)
Göttel, Stefan; Reininghaus, Frank; Schoeller, Herbert
2015-07-01
We study a pseudo-spin-1/2 quantum dot in the cotunneling regime close to the particle-hole symmetric point. For a generic tunneling matrix we find a fixed point with interesting nonequilibrium properties, characterized by effective reservoirs with compensating spin orientation vectors weighted by the polarizations and the tunneling rates. At large bias voltage we study the magnetic field dependence of the dot magnetization and the current. The fixed point can be clearly identified by analyzing the magnetization of the dot. We characterize the universal properties for the case of two reservoirs and discuss deviations from the fixed point model in experimentally realistic situations.
The EuroSITES network: Integrating and enhancing fixed-point open ocean observatories around Europe
NASA Astrophysics Data System (ADS)
Lampitt, Richard S.; Larkin, Kate E.; EuroSITES Consortium
2010-05-01
EuroSITES is a 3 year (2008-2011) EU collaborative project (3.5MEuro) with the objective to integrate and enhance the nine existing open ocean fixed point observatories around Europe (www.eurosites.info). These observatories are primarily composed of full depth moorings and make multidisciplinary in situ observations within the water column as the European contribution to the global array OceanSITES (www.oceansites.org). In the first 18 months, all 9 observatories have been active and integration has been significant through the maintenance and enhancement of observatory hardware. Highlights include the enhancement of observatories with sensors to measure O2, pCO2, chlorophyll, and nitrate in near real-time from the upper 1000 m. In addition, some seafloor missions are also actively supported. These include seafloor platforms currently deployed in the Mediterranean, one for tsunami detection and one to monitor fluid flow related to seismic activity and slope stability. Upcoming seafloor science missions in 2010 include monitoring benthic biological communities and associated biogeochemistry as indicators of climate change in both the Northeast Atlantic and Mediterranean. EuroSITES also promotes the development of innovative sensors and samplers in order to progress capability to measure climate-relevant properties of the ocean. These include further developing current technologies for autonomous long-term monitoring of oxygen consumption in the mesopelagic, pH and mesozooplankton abundance. Many of these science missions are directly related to complementary activities in other European projects such as EPOCA, HYPOX and ESONET. In 2010 a direct collaboration including in situ field work will take place between ESONET and EuroSITES. The demonstration mission MODOO (funded by ESONET) will be implemented in 2010 at the EuroSITES PAP observatory. Field work will include deployment of a seafloor lander system with various sensors which will send data to shore in real time via the EuroSITES water column infrastructure. EuroSITES Data management is led by NOCS, UK with CORIOLIS, France as one of the Global Data assembly centre (GDAC) for both EuroSITES and OceanSITES. EuroSITES maintains the OceanSITES and GEO philosophy of open access to data in near real-time. With a common data policy and standardised data formats (OceanSITES NetCDF) EuroSITES is increasing the potential users of in situ ocean datasets and the societal benefit of these data. For instance, CORIOLIS is central to the ever increasing contribution of EuroSITES as an upstream data provider to the GMES project MyOcean (both real-time and delayed-mode data). Outreach and knowledge transfer of EuroSITES activities and results are also a key component to the project with a dedicated outreach website, Fact Sheet, cruise diaries and educational tools being developed in the first 18 months. In 2010 a film will be released to represent the network and this will be distributed to a wide audience through the European network of aquaria and at other outreach events. In addition, the EuroSITES project and it's relevance to global ocean observation initiatives continues to be actively promoted at both scientific and non-specialist meetings and events. By the end of EuroSITES in April 2011, the 9 core ocean observatories will be well integrated. Each observatory will have enhanced infrastructure to include both physical and biogeoechemical sensors. Science missions in the ocean interior and seafloor/subseafloor will have progressed European ocean observational capability significantly. Collaborations will have taken place or will be at an advanced stage of planning with related European and international projects including ESONET FP6 NoE and the NSF funded Ocean Observatories Initiative (OOI) (400M over 5 years). EuroSITES will continue to develop it's contribution to the ocean component of the Group on Earth Observations (GEO) through task AR-09-03c 'Global Ocean Observing Systems' and related societal benefit areas.
Antila, Hanne S; Salonen, Emppu
2015-04-15
The Thole induced point dipole model is combined with three different point charge fitting methods, Merz-Kollman (MK), charges from electrostatic potentials using a grid (CHELPG), and restrained electrostatic potential (RESP), and two multipole algorithms, distributed multipole analysis (DMA) and Gaussian multipole model (GMM), which can be used to describe the electrostatic potential (ESP) around molecules in molecular mechanics force fields. This is done to study how the different methods perform when intramolecular polarizability contributions are self-consistently removed from the fitting done in the force field parametrization. It is demonstrated that the polarizable versions of the partial charge models provide a good compromise between accuracy and computational efficiency in describing the ESP of small organic molecules undergoing conformational changes. For the point charge models, the inclusion of polarizability reduced the the average root mean square error of ESP over the test set by 4-10%. PMID:25753482
Kleinert, H; Pelster, A; Bachmann, M
1999-09-01
We introduce a general class of generating functionals for the calculation of quantum-mechanical expectation values of arbitrary functionals of fluctuating paths with fixed end points in configuration or momentum space. The generating functionals are calculated explicitly for the harmonic oscillator with time-dependent frequency, and used to derive a smearing formula for correlation functions of polynomial and nonpolynomial functions of time-dependent positions and momenta. This formula summarizes the effect of quantum fluctuations, and serves to derive generalized Wick rules and Feynman diagrams for perturbation expansions of nonpolynomial interactions. PMID:11970049
Applied Dynamical Systems Problem Sheet 2 1. Find and classify the fixed points for
Burton, Geoffrey R.
in nonlinear electric circuits, and has also been used to model neurons and tectonic plates: Â¨x + b(x2 - 1) x at every point, (c) has period 3, (d) is not periodic, convergent or divergent. (e) (harder) is dense (ie
DOE /NV
1999-06-19
This Corrective Action Decision Document (CADD) has been prepared for Corrective Action Unit (CAU) 423, Building 03-60 Underground Discharge Point (UDP) in accordance with the Federal Facility Agreement and Consent Order (FFACO) of 1996 that was agreed to by the US Department of Energy, Nevada Operations Office (DOE/NV); the Nevada Division of Environmental Protection (NDEP); and the U.S Department of Defense (FFACO, 1996). The CADD provides or references the specific information necessary to recommend a preferred corrective action for the single Corrective Action Site (CAS), 03-02-002-0308, within CAU 423. Corrective Action Unit 423 is located at the Tonopah Test Range (TTR), Nevada. The TTR is approximately 255 kilometers (km) (140 miles[mi]) northwest of Las Vegas, Nevada. The UDP is approximately 73 meters (m) (240 feet [ft]) northwest of the northwest corner of Building 03-60, the Auto Maintenance Shop. Corrective Action Unit 423 is comprised of the UDP and an associated discharge line extending from Building 03-60. The UDP received waste oil products from the Auto Maintenance Shop, a light-duty fleet maintenance shop in the Area 3 compound, from 1965 to 1989 or 1990 (DOE/NV, 1997).
Kainz, K; Prah, D; Ahunbay, E; Li, X
2014-06-01
Purpose: A novel modulated arc therapy technique, mARC, enables superposition of step-and-shoot IMRT segments upon a subset of the optimization points (OPs) of a continuous-arc delivery. We compare two approaches to mARC planning: one with the number of OPs fixed throughout optimization, and another where the planning system determines the number of OPs in the final plan, subject to an upper limit defined at the outset. Methods: Fixed-OP mARC planning was performed for representative cases using Panther v. 5.01 (Prowess, Inc.), while variable-OP mARC planning used Monaco v. 5.00 (Elekta, Inc.). All Monaco planning used an upper limit of 91 OPs; those OPs with minimal MU were removed during optimization. Plans were delivered, and delivery times recorded, on a Siemens Artiste accelerator using a flat 6MV beam with 300 MU/min rate. Dose distributions measured using ArcCheck (Sun Nuclear Corporation, Inc.) were compared with the plan calculation; the two were deemed consistent if they agreed to within 3.5% in absolute dose and 3.5 mm in distance-to-agreement among > 95% of the diodes within the direct beam. Results: Example cases included a prostate and a head-and-neck planned with a single arc and fraction doses of 1.8 and 2.0 Gy, respectively. Aside from slightly more uniform target dose for the variable-OP plans, the DVHs for the two techniques were similar. For the fixed-OP technique, the number of OPs was 38 and 39, and the delivery time was 228 and 259 seconds, respectively, for the prostate and head-and-neck cases. For the final variable-OP plans, there were 91 and 85 OPs, and the delivery time was 296 and 440 seconds, correspondingly longer than for fixed-OP. Conclusion: For mARC, both the fixed-OP and variable-OP approaches produced comparable-quality plans whose delivery was successfully verified. To keep delivery time per fraction short, a fixed-OP planning approach is preferred.
NASA Astrophysics Data System (ADS)
Kim, Yong-Gyoo; Kim, Bong Hak; Yang, Inseok
2010-06-01
We have developed a blackbody comparison system to validate the fixed-point realization of the thermocouple temperature scale using the radiation thermometry scale. Platinum/palladium, type S and type B thermocouples were calibrated at the fixed points of Ag, Cu, Fe-C, Co-C and Pd (only for type B). The radiation thermometer used was an LP4 linear pyrometer operating at a central wavelength of 650 nm. To assign the Fe-C eutectic melting temperature in our laboratory, a radiometric Fe-C cell was fabricated, and its melting temperature was determined as (1154.0 ± 0.1) °C with k = 2. Two scales were compared from 962 °C to 1555 °C in the blackbody comparison system. The two scales were consistent within 0.5 °C up to 1400 °C, but the discrepancy for the type B thermocouple increased to 2.3 °C at 1554.8 °C. The thermocouple and radiometric scales realized at our laboratory were in agreement up to the freezing temperature of Pd within the measurement uncertainty.
NASA Astrophysics Data System (ADS)
Pearce, J. V.; Machin, G.; Ford, T.; Wardle, S.
2008-02-01
Improvement of energy efficiency of jet aircraft is achieved by operating gas turbine engines at higher temperatures. To facilitate this, gas turbine engine manufacturers are continuously developing new alloys for hot-zone turbine blades that will withstand the increased in-service temperatures. A critical part of the manufacture of these blades is heat treatment to ensure that they attain the necessary metallurgical characteristics. Current heat-treatment temperature-control requirements are at the limit of what is achievable with conventional thermocouple calibrations. A project that will allow thermocouple manufacturer CCPI Europe Ltd. to realize uncertainties of ± 1°C, or better, in the calibration of its noble metal thermocouples is described. This will be realized through implementing a Co C eutectic fixed point in CCPI’s calibration chain. As this melts at 1,324°C, very close to the heat-treatment temperatures required, low uncertainties will be obtained. This should yield an increase in effectiveness of the heat-treatment process performed by Bodycote Heat Treatments Ltd., allowing them to respond effectively to the increasingly stringent demands of engine manufacturers. Outside the current project, there is a strong requirement by industry for lower uncertainties at and above 1,300°C. Successful implementation of the current fixed point in an industrial setting is likely to result in rapid take-up by other companies, probably through the supply of ultra-low uncertainty thermocouples, looking to improve their high-temperature processes.
K. B. Campbell
2002-06-01
This Corrective Action Plan (CAP) provides selected corrective action alternatives and proposes the closure methodology for Corrective Action Unit (CAU) 262, Area 25 Septic Systems and Underground Discharge Point. CAU 262 is identified in the Federal Facility Agreement and Consent Order (FFACO) of 1996. Remediation of CAU 262 is required under the FFACO. CAU 262 is located in Area 25 of the Nevada Test Site (NTS), approximately 100 kilometers (km) (62 miles [mi]) northwest of Las Vegas, Nevada. The nine Corrective Action Sites (CASs) within CAU 262 are located in the Nuclear Rocket Development Station complex. Individual CASs are located in the vicinity of the Reactor Maintenance, Assembly, and Disassembly (R-MAD); Engine Maintenance, Assembly, and Disassembly (E-MAD); and Test Cell C compounds. CAU 262 includes the following CASs as provided in the FFACO (1996); CAS 25-02-06, Underground Storage Tank; CAS 25-04-06, Septic Systems A and B; CAS 25-04-07, Septic System; CAS 25-05-03, Leachfield; CAS 25-05-05, Leachfield; CAS 25-05-06, Leachfield; CAS 25-05-08, Radioactive Leachfield; CAS 25-05-12, Leachfield; and CAS 25-51-01, Dry Well. Figures 2, 3, and 4 show the locations of the R-MAD, the E-MAD, and the Test Cell C CASs, respectively. The facilities within CAU 262 supported nuclear rocket reactor engine testing. Activities associated with the program were performed between 1958 and 1973. However, several other projects used the facilities after 1973. A significant quantity of radioactive and sanitary waste was produced during routine operations. Most of the radioactive waste was managed by disposal in the posted leachfields. Sanitary wastes were disposed in sanitary leachfields. Septic tanks, present at sanitary leachfields (i.e., CAS 25-02-06,2504-06 [Septic Systems A and B], 25-04-07, 25-05-05,25-05-12) allowed solids to settle out of suspension prior to entering the leachfield. Posted leachfields do not contain septic tanks. All CASs located in CAU 262 are inactive or abandoned. However, some leachfields may still receive liquids from runoff during storm events. Results from the 2000-2001 site characterization activities conducted by International Technology (IT) Corporation, Las Vegas Office are documented in the Corrective Action Investigation Report for Corrective Action Unit 262: Area 25 Septic Systems and Underground Discharge Point, Nevada Test Site, Nevada. This document is located in Appendix A of the Corrective Action Decision Document for CAU 262. Area 25 Septic Systems and Underground Discharge Point, Nevada Test Site, Nevada. (DOE/NV, 2001).
NASA Astrophysics Data System (ADS)
Todd, A. D. W.; Woods, D. J.
2013-02-01
This paper outlines measurements made at the National Research Council Canada (NRC) of the thermodynamic melting temperatures of Co-C, Pt-C and Re-C fixed points that have been part of the high-temperature fixed-point research plan of Working Group 5 of the Consultative Committee for Thermometry (CCT-WG5) to assign melting temperatures to those fixed points. This document will outline the equipment used, describe the scheme used to calibrate a pyrometer with traceability to a cryogenic electrical substitution radiometer, and detail the method of measuring the fixed points. It will then report the uncertainties in the measurements and the results. A brief description of the improvements that we plan to implement to the scheme to reduce the uncertainties for future measurements will be given. The thermodynamic temperatures determined for the three fixed points are: 1597.776 K with an expanded uncertainty of 0.36 K, 2011.390 K with an expanded uncertainty of 0.55 K, and 2748.056 K with an expanded uncertainty of 0.95 K, for the Co-C, Pt-C and Re-C fixed points, respectively (all expanded uncertainties assume a 95% confidence interval and a Gaussian distribution).
Construction of Home-Made Tin Fixed-Point Cell at TUBITAK UME
NASA Astrophysics Data System (ADS)
Kalemci, M.; Arifovic, N.; Ba?çe, A.; Aytekin, S. O.; Ince, A. T.
2015-08-01
TUBITAK UME Temperature Laboratory initiated a new study which focuses on the construction of a tin freezing-point cell as a primary temperature standard. The design is an open-cell type similar to the National Institute of Standards and Technology design. With this aim, a brand new vacuum and filling line employing an oil diffusion pump and two cold traps (liquid nitrogen and dry ice) was set-up. The graphite parts (crucible, thermometer well, etc.) have been baked at high temperature under vacuum. Each cell was filled with approximately 1 kg of high-purity tin (99.9999 %) in a three-zone furnace. Then several melting and freezing curves were obtained to assess the quality of the home-made cell, and also the new cell was compared with the existing reference cell of the laboratory. The results obtained are very close to the reference cell of UME, indicating that the method used for fabrication was promising and satisfactory and also seems to meet the requirements to have a primary level temperature standard.
Construction of Home-Made Tin Fixed-Point Cell at TUBITAK UME
NASA Astrophysics Data System (ADS)
Kalemci, M.; Arifovic, N.; Ba?çe, A.; Aytekin, S. O.; Ince, A. T.
2015-07-01
TUBITAK UME Temperature Laboratory initiated a new study which focuses on the construction of a tin freezing-point cell as a primary temperature standard. The design is an open-cell type similar to the National Institute of Standards and Technology design. With this aim, a brand new vacuum and filling line employing an oil diffusion pump and two cold traps (liquid nitrogen and dry ice) was set-up. The graphite parts (crucible, thermometer well, etc.) have been baked at high temperature under vacuum. Each cell was filled with approximately 1 kg of high-purity tin (99.9999 %) in a three-zone furnace. Then several melting and freezing curves were obtained to assess the quality of the home-made cell, and also the new cell was compared with the existing reference cell of the laboratory. The results obtained are very close to the reference cell of UME, indicating that the method used for fabrication was promising and satisfactory and also seems to meet the requirements to have a primary level temperature standard.
A Phase-Field Solidification Model of Almost Pure ITS-90 Fixed Points
NASA Astrophysics Data System (ADS)
Large, M. J.; Pearce, J. V.
2014-07-01
A two-dimensional axisymmetric phase-field model of thermo-solutal solidification in freezing-point cells used for calibrating standard platinum resistance thermometers for realization and dissemination of the International Temperature Scale of 1990 is presented. The cell is essentially a graphite crucible containing an ingot of very pure metal (of order 99.9999 %). A graphite tube is inserted along the axis of the ingot to enable immersion of the thermometer in the metal. In this study, the metal is tin (freezing temperature of ). During the freezing of these cells, a steady, reproducible temperature is realized, with a defined temperature that can be used to calibrate thermometers with uncertainties mK. The model is applied to understand the effect of experimental parameters, such as initiation technique and furnace homogeneity, on the measured freezing curve. Results show that freezing curves whose behavior is consistent with the Scheil theory of solidification can be obtained with a specific furnace temperature profile, and provided that the freeze is of a long duration, the results are consistent with previous one-dimensional models and experiments. Morphological instability is observed with the inner interface initiation technique, causing the interface to adopt a cellular structure. This elevates the measured temperature, in accordance with the Gibbs-Thomson effect. In addition, the influence of initiation techniques on the solidification behavior is examined. The model indicates that an initially smooth inner mantle can `de-wet' from the thermometer well-forming agglomerated solid droplets, following recalescence, under certain conditions. This manifests as a measured temperature depression due to the Gibbs-Thomson effect, with a magnitude of to in simulations. The temperature rises to that of the stable outer mantle as freezing progresses and the droplets re-melt. It is demonstrated that the effect occurs below a critical mantle thickness. A physical explanation for the origin of the effect is offered showing that it is consistent with solid-state de-wetting phenomena. Consideration is also given to the limitations of the current model configuration.
Selbig, William R.; Bannerman, Roger T.
2011-01-01
The U.S Geological Survey, in cooperation with the Wisconsin Department of Natural Resources (WDNR) and in collaboration with the Root River Municipal Stormwater Permit Group monitored eight urban source areas representing six types of source areas in or near Madison, Wis. in an effort to improve characterization of particle-size distributions in urban stormwater by use of fixed-point sample collection methods. The types of source areas were parking lot, feeder street, collector street, arterial street, rooftop, and mixed use. This information can then be used by environmental managers and engineers when selecting the most appropriate control devices for the removal of solids from urban stormwater. Mixed-use and parking-lot study areas had the lowest median particle sizes (42 and 54 (u or mu)m, respectively), followed by the collector street study area (70 (u or mu)m). Both arterial street and institutional roof study areas had similar median particle sizes of approximately 95 (u or mu)m. Finally, the feeder street study area showed the largest median particle size of nearly 200 (u or mu)m. Median particle sizes measured as part of this study were somewhat comparable to those reported in previous studies from similar source areas. The majority of particle mass in four out of six source areas was silt and clay particles that are less than 32 (u or mu)m in size. Distributions of particles ranging from 500 (u or mu)m were highly variable both within and between source areas. Results of this study suggest substantial variability in data can inhibit the development of a single particle-size distribution that is representative of stormwater runoff generated from a single source area or land use. Continued development of improved sample collection methods, such as the depth-integrated sample arm, may reduce variability in particle-size distributions by mitigating the effect of sediment bias inherent with a fixed-point sampler.
NASA Astrophysics Data System (ADS)
Cveti?, Gorazd
2014-02-01
Perturbative QCD (pQCD) running coupling a(Q2) (??s(Q2)/?) is expected to get modified at low spacelike momenta 0
1998-06-01
This Corrective Action Decision Document has been prepared for the Area 3 Building 03-60 Underground Discharge Point (Corrective Action Unit 423) in accordance with the Federal Facility Agreement and Consent Order of 1996 (FFACO, 1996). Corrective Action Unit 423 is located at the Tonopah Test Range and is comprised of Corrective Action Site 03-02-002-0308. The purpose of this Corrective Action Decision Document is to identify and provide a rationale for the selection of a recommended corrective action alternative for Corrective Action Unit 423. The scope of this Correction Action Decision Document consists of the following: ? Develop corrective action objectives. ? Identify corrective action alternative screening criteria. ? Develop corrective action alternatives. ? Perform detailed and comparative evaluations of the corrective action alternatives in relation to the corrective action objectives and screening criteria. ? Recommend and justify a preferred corrective action alternative for the Corrective Action Unit. In January 1998, a corrective action investigation was performed as set forth in the Corrective Action Investigation Plan for Corrective Action Unit No. 423: Building 03-60 Underground Discharge Point, Tonopah Test Range, Nevada (DOE/NV, 1997). A hydrocarbon plume was found to emanate from near the bottom of the Underground Discharge Point to the west. The plume encompasses approximately 65 square meters (700 square feet). The highest total petroleum hydrocarbon level detected was 2,400 milligrams per kilogram. No other contaminants were detected above preliminary action levels. Details of the investigation can be found in Appendix A of this document. Based on the potential exposure pathways identified during the Data Quality Objectives process, the following corrective action objectives have been identified for Corrective Action Unit 423: ? Prevent or mitigate human exposure to subsurface soil containing contaminants of concern. ? Prevent adverse impacts to groundwater quality. Based on the review of existing data, future land use assumption, and current operations at the Tonopah Test Range, the following alternatives were developed for consideration at the Building 03-60 Underground Discharge Point: ? Alternative 1 - No Action ? Alternative 2 - Closure in Place with Administrative Controls ? Alternative 3 - Partial Excavation, Disposal, and Administrative Controls ? Alternative 4 - In Situ Bioremediation The corrective action alternatives were evaluated based on four general corrective action standards and five remedy selection decision factors. Based on the results of this evaluation, the preferred alternative for Corrective Action Unit 423 is Alternative 2, Closure in Place with Administrative Controls. The preferred corrective action alternative was evaluated on technical merit, focusing on performance, reliability, feasibility, and safety. The alternative was judged to meet all requirements for the technical components evaluated. The alternative also meets all applicable state and federal regulations for closure of the site and will reduce potential future exposure pathways to the contaminated soils.
Steinberg, Richard N.
Action Research on Underpinnings for Physics by Jeffrey Hengesbach, Mountain Pointe High School with examining the science background (underpinnings) appropriate for students starting high school physics to physics. In many cases, at the high school level it is the first opportunity a student has to truly
"Raising the Point!": An Artistic Approach in Supporting a Community's Call to Action
ERIC Educational Resources Information Center
Mendez, Jason
2013-01-01
This article discusses the notion of action and personal agency. The author discusses his experiences constructing an arts installation that supported a grassroots effort to revitalize Hunts Point, a community in the South Bronx that is home to 11,000 families, eighteen waste transfer stations, 40% of New York City's sewage, all of the…
NASA Astrophysics Data System (ADS)
Bounias, Michel
2000-05-01
A physical space can exist as a collection of closed topologies in the intersections of abstract topological subspaces provided with non-equal dimensions. Furthermore, the ordered sequence of mappings of one to another intersection provides an arrow of time which is shared by all connected systems of closed, involving those of the brain type with other types (i.e., physical objects of all categories). The topology of closed spaces associates fixed points of the Brouwer's type with fixed points of the Banach's type. The former are specific of each closed and the latter drive the information from the outside space to mental images inside a closed, through mappings of Jordan's points. The set of fixed points thus provides the properties of both perception and self in living organisms. Conditions for existence of various kinds of Banach's type fixed points are fulfilled by the mathematical brain, since it is both a discrete finite structure, thus a compact topological space, and provided with a set distance (?), thus ?-complete. Finally, since (i) iterates in a sequence of mappings include at least a surjective component and (ii) not identical (if even existing) fixed points would be generated by the non-surjective property which would characterize reciprocal mappings, in either metric or nonmetric setting, the reversion of biological time would break the direct link of the self with perception functions. Thus, while time could be reversible for physics, it is perceived as irreversible for biology, although physical and biological objects share a common space.
Kelly, Frank
. An important assumption for the validity of a fixed-point approach is that traffic correlation across resources the natural operating point for TCP, which depends on route lengths (via round-trip times and number of resources), end-to-end packet loss and the number of user sessions. 1. Introduction Internet Service
Fogle, W.E.; Hornung, E.W.; Mayberry, M.C.; Phillips, N.E.
1981-08-01
Comparison of a powdered CMN thermometer with an NBS fixed point device demonstrates an internal inconsistency in the T/sub c/'s assigned to the fixed point device. T/sub c/'s between 100 and 200 mK are in excellent agreement with a temperature scale interpolated between He vapor pressure temperatures and nuclear orientation temperatures, but there is a discrepancy of 8% at the 15 mK point. Evidence for different susceptibility-temperature relations for superficially similar CMN thermometers is also presented.
NASA Astrophysics Data System (ADS)
Suherlan; Kim, Yong-Gyoo; Yang, Inseok
2013-06-01
Five Si-SiC eutectic fixed-point cells were constructed for use in thermocouple thermometry. Two cells were made from a silicon and carbon mixture within a graphite crucible; the other three were made from pure silicon. The first broke after 12 melt-freeze cycles due to weaknesses in the crucible; the other four, made with a modified crucible that was thicker and shorter than the first type, were more resistant to failure. The second, subjected to various furnace settings, was able to withstand up to 36 cycles. The third, subjected to only the furnace setting of 5 °C above and below the transition temperature, was able to withstand 56 cycles. The fourth was rapidly cooled in an unpowered furnace from 600 °C, then removed from the furnace at 300 °C and allowed to cool to room temperature. With this repeated treatment, the cell broke after only 25 cycles. The fifth was treated gently with a slow rate of 1 °C min-1 through both melting and freezing, and 2 °C min-1 to 3 °C min-1 when cooling. This cell was successfully tested through 80 melt-freeze cycles without any mechanical failure. The melting point of the five Si-SiC cells based on its maximum drift agreed within 1.2 °C.
Pointing losses in single-axis and fixed-mount earth-station antennas due to satellite movement
NASA Astrophysics Data System (ADS)
Buchsbaum, L. M.
1986-06-01
There are substantial cost advantages in the use of single-axis or fixed-mount earth-station antennas, thus reducing or eliminating the need for autotracking in earth-stations operating with quasi-stationary satellites. Such cost advantages are more relevant in small antennas where the tracking system represents a larger percentage of the overall cost. In addition, small antennas are particularly suitable to be operated without autotracking, owing to their wider half-power beamwidth. This paper describes a model for calculating the antenna pointing loss as a function of the antenna diameter, operating frequency band, satellite station-keeping tolerances, and the relative geometry between the earth-station and the satellite. The model has been extensively used in the development of Intelsat's IBS and VISTA services as well as in domestic leases. Although the model has been developed based on orbital mechanics equations, its emphasis is towards earth-station and systems engineering applications. Some example calculations and results obtained through an HP-41 CV programmable calculator are also provided.
NASA Astrophysics Data System (ADS)
Wu, Jia Lin
2012-06-01
The existence of fixed point in self-similar Lennard-Jones (L-J) potentials has been proved based on the mosaic geometric structure theory of glass transition (GT) [J. L. Wu, Soft Nanoscience letters, 1, 3-86 (2011)]. A geometric local-global mode-coupling recursive equation, different from the current Mode-Coupling Theories, has been introduced to find out the non-integrable induced potential structure of boson peak at GT. The recursively defined variable in reduced recursive equation is the potential fluctuation of reduced L-J potentials associated with reduced geometric phase potentials. A series of results have been deduced directly at GT. (i) There are only 8 orders of molecule-clusters. (ii) Two orthogonally fast-slow reduced phase potentials, 3/8 and 5/8, are accompanied with density fluctuation and clusters hop-delocalization along 8 geodesics. (iii) The stability condition of potential fluctuation is the Lindemann ratio. (iv) A new reduced attractive potential of -17/16, lower than reduced potential well energy -1, occurs.
Referral of tactile stimuli to action points in virtual reality with reaction force.
Moizumi, Shunjiro; Yamamoto, Shinya; Kitazawa, Shigeru
2007-09-01
When we touch something with a tool, we feel the touch at the tip of the tool rather than at the hand. Yamamoto and Kitazawa [Yamamoto, S., Kitazawa, S., 2001b. Sensation at the tips of invisible tools. Nat. Neurosci. 4, 979-980] previously showed that the judgment of the temporal order of two successive stimuli, delivered to the tips of sticks held in each hand, was dramatically altered by crossing the sticks without changing the positions of the hands. This provided evidence for the referral of tactile signals to the tip of a tool in hand. In this study, we examined importance of force feedback from the tool in the referral by manipulating the direction of force feedback in a virtual reality. The virtual tool consisted of a spherical action point that was moved with a stylus in hand. Subjects held two styli, one in each hand, put each action point on each of two buttons in the virtual reality, and were required to judge the order of successive taps, delivered to the two styli. We manipulated the direction of reaction force from each button so that it was congruent or incongruent to the visual configuration of the button. When the arms were uncrossed, judgment primarily depended on whether the action points were crossed or not in the visual space. But when the arms were crossed, judgment critically depended on the direction of force feedback. The results show that tactile signals can be referred to the action point in the virtual reality and that the force feedback becomes a critical factor when the arms are crossed. PMID:17617482
Carreira-PerpiÃ±Ã¡n, Miguel Ã.
Conclusions and future work We have shown that, in general, the fixed points of CD differ from those of ML, and thus CD is a biased algorithm. However, our empirical results show the bias is generally very small, since CD typically converges very near an ML optimum. And this small bias can
ERIC Educational Resources Information Center
Bellver-Cebreros, Consuelo; Rodriguez-Danta, Marcelo
2009-01-01
An apparently unnoticed analogy between the torque-free motion of a rotating rigid body about a fixed point and the propagation of light in anisotropic media is stated. First, a new plane construction for visualizing this torque-free motion is proposed. This method uses an intrinsic representation alternative to angular momentum and independent of…
Evaluation of color spatio-temporal interest points for human action recognition.
Everts, Ivo; van Gemert, Jan C; Gevers, Theo
2014-04-01
This paper considers the recognition of realistic human actions in videos based on spatio-temporal interest points (STIPs). Existing STIP-based action recognition approaches operate on intensity representations of the image data. Because of this, these approaches are sensitive to disturbing photometric phenomena, such as shadows and highlights. In addition, valuable information is neglected by discarding chromaticity from the photometric representation. These issues are addressed by color STIPs. Color STIPs are multichannel reformulations of STIP detectors and descriptors, for which we consider a number of chromatic and invariant representations derived from the opponent color space. Color STIPs are shown to outperform their intensity-based counterparts on the challenging UCF sports, UCF11 and UCF50 action recognition benchmarks by more than 5% on average, where most of the gain is due to the multichannel descriptors. In addition, the results show that color STIPs are currently the single best low-level feature choice for STIP-based approaches to human action recognition. PMID:24577192
state that disciplinary action may be taken if a trigger point is hit for
Daley, Monica A.
state that disciplinary action may be taken if a trigger point is hit for 3rd time ask OH nO further actIOn Other than tO cOntInuOusLy mOnItOr absence nO braDfOrD trIGGer hIt nO braDfOrD trIGGer hIt nO braDfOrD trIGGer hIt staGe 1 staGe 2 fOLLOWs a 1st reVIeW meetInG staGe 3 fOLLOWs a 2nD reVIeW meet
Vandewalle, Emily Lauren
2014-04-30
that the technological fix for the socio-environmental problem of acceptable drinking water will likely add more financial and labor burdens on already vulnerable populations. Consequently, the rollout of these technologies shifts the costs of acceptable and secure...
D. S. Tobiason
2003-01-01
This Closure Report (CR) documents the activities undertaken to close Corrective Action Unit (CAU) 262: Area 25 Septic Systems and Underground Discharge Point, in accordance with the Federal Facility Agreement and Consent Order (FFACO) of 1996. Site closure was performed in accordance with the Nevada Division of Environmental Protection (NDEP)-approved Corrective Action Plan (CAP) for CAU 262 (U.S. Department of
NASA Astrophysics Data System (ADS)
Lowe, D.; Heufelder, S.
2013-06-01
The melting temperatures of the eutectic phase transitions of cobalt-carbon, platinum-carbon and rhenium-carbon alloys are proposed as reference standards for high temperature radiation thermometry. The behaviour of these is such that rather than a unique readily identified feature of the melting curve being assigned a temperature, upper and lower limits will be given. The lower limit will be the point of inflection in the melting curve, a point previously identified as unchanging with the rate at which melting takes place. The upper limit will be based on an extrapolation of the tangent at the point of inflection. The melting curves of cobalt-carbon fixed points are measured and it is found that the upper and lower limits converge as the melting rate is reduced. The point of inflection appears to have a melting rate dependence while the upper limit appears to be much more stable. This may have implications for planned research into assignment of thermodynamic temperature to these fixed points.
NASA Technical Reports Server (NTRS)
White, M. D.
1944-01-01
Detail calculations are presented of the shifts in stick-fixed neutral point of the Republic XF-12 airplane due to the windmilling propellers and to the fuselage. The results of these calculations differ somewhat from those previously made for this airplane by Republic Aviation Corporation personnel under the direction of Langley flight division personnel. Due to these differences the neutral point for the airplane is predicted to be 37.8 percent mean aerodynamic chord, instead of 40.8 percent mean aerodynamic chord as previously reported.
Caggiano, Vittorio; Giese, Martin; Thier, Peter; Casile, Antonino
2015-02-01
The discovery of mirror neurons compellingly shows that the monkey premotor area F5 is active not only during the execution but also during the observation of goal-directed motor acts. Previous studies have addressed the functioning of the mirror-neuron system at the single-unit level. Here, we tackled this research question at the network level by analysing local field potentials in area F5 while the monkey was presented with goal-directed actions executed by a human or monkey actor and observed either from a first-person or third-person perspective. Our analysis showed that rhythmic responses are not only present in area F5 during action observation, but are also modulated by the point of view. Observing an action from a subjective point of view produced significantly higher power in the low-frequency band (2-10 Hz) than observing the same action from a frontal view. Interestingly, an increase in power in the 2-10 Hz band was also produced by the execution of goal-directed motor acts. Independently of the point of view, action observation also produced a significant decrease in power in the 15-40 Hz band and an increase in the 60-100 Hz band. These results suggest that, depending on the point of view, action observation might activate different processes in area F5. Furthermore, they may provide information about the functional architecture of action perception in primates. PMID:25442357
ERIC Educational Resources Information Center
Gillberg, Claudia
2011-01-01
Against the background of Swedish preschool's historical and traditional functions in Swedish society, this article focuses on some of the choice points and their implications for professional and organisational development in preschool. By combining feminist pragmatism and feminist action research, some analytical points are made regarding the…
Shimamoto, Akira; Yamashita, Keitaro; Inoue, Hirofumi; Yang, Sung-Mo; Iwata, Masahiro; Ike, Natsuko
2013-04-01
Destructive tests are generally applied to evaluate the fixed strength of spot-welding nuggets of zinc-plated steel (which is a widely used primary structural material for automobiles). These destructive tests, however, are expensive and time-consuming. This paper proposes a nondestructive method for evaluating the fixed strength of the welded joints using surface electrical resistance. A direct current nugget-tester and probes have been developed by the authors for this purpose. The proposed nondestructive method uses the relative decrease in surface electrical resistance, ?. The proposed method also considers the effect of the corona bond. The nugget diameter is estimated by two factors: R Quota, which is calculated from variation of resistance, and a constant that represents the area of the corona bond. Since the maximum tensile strength is correlated with the nugget diameter, it can be inferred from the estimated nugget diameter. When appropriate measuring conditions for the surface electrical resistance are chosen, the proposed method can effectively evaluate the fixed strength of the spot-welded joints even if the steel sheet is zinc-plated. PMID:24891747
NONE
1997-10-27
This Corrective Action Investigation Plan (CAIP) contains the environmental sample collection objectives and the criteria for conducting site investigation activities at Corrective Action Unit (CAU) Number 423, the Building 03-60 Underground Discharge Point (UDP), which is located in Area 3 at the Tonopah Test Range (TTR). The TTR, part of the Nellis Air Force Range, is approximately 225 kilometers (140 miles) northwest of Las Vegas, Nevada. CAU Number 423 is comprised of only one Corrective Action Site (CAS) which includes the Building 03-60 UDP and an associated discharge line extending from Building 03-60 to a point approximately 73 meters (240 feet) northwest. The UDP was used between approximately 1965 and 1990 to dispose of waste fluids from the Building 03-60 automotive maintenance shop. It is likely that soils surrounding the UDP have been impacted by oil, grease, cleaning supplies and solvents as well as waste motor oil and other automotive fluids released from the UDP.
DOE /NV
1997-10-01
This Corrective Action Investigation Plan (CAIP) has been developed in accordance with the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the US Department of Energy, Nevada Operations Office (DOE/NV), the State of Nevada Division of Environmental Protection (NDEP), and the US Department of Defense. The CAIP is a document that provides or references all of the specific information for investigation activities associated with Corrective Action Units (CAUS) or Corrective Action Sites (CASs) (FFACO, 1996). As per the FFACO (1996), CASs are sites potentially requiring corrective action(s) and may include solid waste management units or individual disposal or release sites. Corrective Action Units consist of one or more CASs grouped together based on geography, technical similarity, or agency responsibility for the purpose of determining corrective actions. This CAIP contains the environmental sample collection objectives and the criteria for conducting site investigation activities at CAU No. 423, the Building 03-60 Underground Discharge Point (UDP), which is located in Area 3 at the Tonopah Test Range (TTR). The TTR, part of the Nellis Air Force Range, is approximately 225 kilometers (km) (140 miles [mi]) northwest of Las Vegas, Nevada (Figures 1-1 and 1-2). Corrective Action Unit No. 423 is comprised of only one CAS (No. 03-02-002-0308), which includes the Building 03-60 UDP and an associated discharge line extending from Building 03-60 to a point approximately 73 meters (m) (240 feet [ft]) northwest as shown on Figure 1-3.
Balle, C; Fortescue-Beck, E; Vauthier, N
2013-01-01
The cernox™ sensor is delivered with a 3-point resistance versus temperature cal-ibration that permits the construction of an individual interpolation table by using the data in the CERN thermometer database. For instance at the 4.2 K point, the individual calibration and the manufacturer data are within +/-0.1 K for 99.39% of a sample population of about 5700 sensors. Preliminary results also indicate that accuracies of 0.1 K and 1 K can be obtained below respectively 5 K and 77 K.
Achim Schulze
2008-03-12
We consider the Vlasov-Poisson system with spherical symmetry and an exterior potential which is induced by a point mass in the center. This system can be used as a simple model for a newtonian galaxy surrounding a black hole. For this system, we establish a global existence result for classical solutions with shell-like initial data, i.e. the support of the density is bounded away from the point mass singularity. We also prove existence and stability of stationary solutions which describe static shells, where we use a variational approach which was established by Y. Guo and G. Rein.
Bechtel Nevada
1998-10-31
The Corrective Action Plan provides the closure methods for Corrective Action Unit (CAU) 423: Area 3 Building 03-60 Underground Discharge Point (UDP), Tonoopah Test Range, Nevada. CAU 423 consists of the UDP and an associated discharge pipeline extending from Building 03-60. Corrective action investigations were completed in January 1998, and are documented in the Corrective Action Decision Document (US DOE, 1998). Results indicate an asymmetrical hydrocarbon plume, measuring 11 meters (m) 35 ft in length, 6 m (20 ft) in width, and 4 to 20 m (14 to 65 ft) in depth, has formed beneath the UDP and migrated westward. Petroleum hydrocarbon levels were identified above the 100 miligrams per kilogram (mg/kg) action level specified in Nevada Administrative Code (NAC) 445A (NAC 1996). The highest petroleum hydrocarbon concentration detected was 2,4000 mg/kg at 6 m, 20 ft, below surface grade as diesel. Corrective actions will consist of administrative controls and in place closure of th e UDP and its associated discharge pipeline.
trajectory of the signal, and is the weight of the th particle (or trajectory) at time . If now, for example and to focus on trajectories that are dominating. Resampling is very impor- tant in particle filtering because-Point Implementation of Residual Resampling Scheme for High-Speed Particle Filters Sangjin Hong, Member, IEEE, Miodrag
Lymans'ky?, Iu P; Tamarova, Z A; Huliar, S O
2003-01-01
In experiments on mice, statistically authentic weakening of visceral pain has been shown after an action of low intensity polarized light from a device Bioptron on antinociceptive acupuncture points (AP). Pain was caused by an intraperitoneal injection of 2% acetic acid (0.1 ml/10 g). The intensity of pain was judged on duration and frequency of painful behavioral reactions (writhing, licking of abdomen), as well as on duration of sleep, eating and motor activity. In animals which immediately after injections of acetic acid were exposed to polarized light of low intensity for 10 min, applied on any of antinociceptive APs (E-36, E-43, VC-8, RP-6), the duration of painful behavioral reaction was determined to be reduced, while that of non-painful one increased. The comparison of the total duration of the writhing at control and experimental mice showed that an activation of AP E-43 induced the greatest analgesic effect (76.5%), from AP VC-8 it was 76.3%, from RP-6--46.8%, and from E-36--41.4%. We have concluded that the effect of polarized light of low intensity on APs was a convenient non-pharmacological method of treating visceral pain. PMID:14663889
NASA Astrophysics Data System (ADS)
Lowe, Dave; Kodwani, Darsh
2015-07-01
Re-calibration of a thermocouple after it has been installed in a process is often not practical. In situ monitoring of performance is desirable and can be done with built-in reference standards based on melting or freezing phase transitions. Binary alloys with a monotectic reaction frequently have two invariant melt/freeze phase transitions taking place in the same material over a range of compositions. This makes them potentially well suited to be in situ temperature calibration artifacts, enabling correction for thermocouple drift without the need to disturb the thermocouple. A zinc-bismuth fixed-point cell was constructed and has been shown to be stable with two well-defined melting plateaus at nominally 255° C and 415° C. Two miniature fixed-point cells (each designed to be permanently installed with a thermocouple) based on zinc-bismuth and aluminum-indium alloys were made. Measurements have shown that the phase transitions can be identified despite the small quantity of metals used and that the alloys were sufficiently stable to have the potential to provide improved long-term confidence in process control and monitoring.
Action and emotion recognition from point light displays: an investigation of gender differences.
Alaerts, Kaat; Nackaerts, Evelien; Meyns, Pieter; Swinnen, Stephan P; Wenderoth, Nicole
2011-01-01
Folk psychology advocates the existence of gender differences in socio-cognitive functions such as 'reading' the mental states of others or discerning subtle differences in body-language. A female advantage has been demonstrated for emotion recognition from facial expressions, but virtually nothing is known about gender differences in recognizing bodily stimuli or body language. The aim of the present study was to investigate potential gender differences in a series of tasks, involving the recognition of distinct features from point light displays (PLDs) depicting bodily movements of a male and female actor. Although recognition scores were considerably high at the overall group level, female participants were more accurate than males in recognizing the depicted actions from PLDs. Response times were significantly higher for males compared to females on PLD recognition tasks involving (i) the general recognition of 'biological motion' versus 'non-biological' (or 'scrambled' motion); or (ii) the recognition of the 'emotional state' of the PLD-figures. No gender differences were revealed for a control test (involving the identification of a color change in one of the dots) and for recognizing the gender of the PLD-figure. In addition, previous findings of a female advantage on a facial emotion recognition test (the 'Reading the Mind in the Eyes Test' (Baron-Cohen, 2001)) were replicated in this study. Interestingly, a strong correlation was revealed between emotion recognition from bodily PLDs versus facial cues. This relationship indicates that inter-individual or gender-dependent differences in recognizing emotions are relatively generalized across facial and bodily emotion perception. Moreover, the tight correlation between a subject's ability to discern subtle emotional cues from PLDs and the subject's ability to basically discriminate biological from non-biological motion provides indications that differences in emotion recognition may - at least to some degree - be related to more basic differences in processing biological motion per se. PMID:21695266
Action and Emotion Recognition from Point Light Displays: An Investigation of Gender Differences
Alaerts, Kaat; Nackaerts, Evelien; Meyns, Pieter; Swinnen, Stephan P.; Wenderoth, Nicole
2011-01-01
Folk psychology advocates the existence of gender differences in socio-cognitive functions such as ‘reading’ the mental states of others or discerning subtle differences in body-language. A female advantage has been demonstrated for emotion recognition from facial expressions, but virtually nothing is known about gender differences in recognizing bodily stimuli or body language. The aim of the present study was to investigate potential gender differences in a series of tasks, involving the recognition of distinct features from point light displays (PLDs) depicting bodily movements of a male and female actor. Although recognition scores were considerably high at the overall group level, female participants were more accurate than males in recognizing the depicted actions from PLDs. Response times were significantly higher for males compared to females on PLD recognition tasks involving (i) the general recognition of ‘biological motion’ versus ‘non-biological’ (or ‘scrambled’ motion); or (ii) the recognition of the ‘emotional state’ of the PLD-figures. No gender differences were revealed for a control test (involving the identification of a color change in one of the dots) and for recognizing the gender of the PLD-figure. In addition, previous findings of a female advantage on a facial emotion recognition test (the ‘Reading the Mind in the Eyes Test’ (Baron-Cohen, 2001)) were replicated in this study. Interestingly, a strong correlation was revealed between emotion recognition from bodily PLDs versus facial cues. This relationship indicates that inter-individual or gender-dependent differences in recognizing emotions are relatively generalized across facial and bodily emotion perception. Moreover, the tight correlation between a subject's ability to discern subtle emotional cues from PLDs and the subject's ability to basically discriminate biological from non-biological motion provides indications that differences in emotion recognition may - at least to some degree – be related to more basic differences in processing biological motion per se. PMID:21695266
NASA Astrophysics Data System (ADS)
Mambrini, Y.; Moultaka, G.
2002-06-01
We investigate the one-loop renormalization-group evolution of extended sectors of Yukawa-type couplings. It is shown that Landau poles, which usually provide the necessary low-energy upper bounds that saturate quickly with increasing initial value conditions, lead in some cases to the opposite behavior: some of the low-energy couplings decrease and become vanishingly small for increasingly large initial conditions. We write down the general criteria for this to happen in typical situations, highlighting a concept of repulsive quasifixed points, and illustrate the case both within a two-Yukawa toy model as well as in the minimal supersymmetric standard model with R-parity violation. In the latter case, we consider the theoretical upper bounds on the various couplings, identifying regimes where ?kl3,?'kkk,??3kl are dynamically suppressed due to the Landau pole. We stress the importance of considering a large number of couplings simultaneously. This leads altogether to a phenomenologically interesting seesaw effect in the magnitudes of the various R-parity violating couplings, complementing and in some cases improving the existing limits.
NASA Astrophysics Data System (ADS)
Elliott, C. J.; Greenen, A.; Lowe, D.; Pearce, J. V.; Machin, G.
2015-04-01
To categorise thermocouples in batches, manufacturers state an expected operating tolerance for when the thermocouples are as-new. In use, thermocouple behaviour can rapidly change and the tolerance becomes invalid, especially when used at high temperatures (i.e. above 1000?°C) as the processes leading to de-calibration, such as oxidation and contamination, can be very fast and lead to erroneous readings. In-situ thermocouple self-validation provides a method to track the drift and correct the thermocouple reading in real-time, but it must be shown to be reliable. Two miniature temperature fixed-point cells designed at NPL for in-situ thermocouple self-validation, the first containing a Pt-C eutectic alloy and the second containing a Ru-C eutectic alloy, have been exposed to temperatures close to their melting point for 2200?h and 1570?h, respectively, and continuously, for up to three months. Recalibration after this long-term high-temperature exposure, where a tantalum-sheathed thermocouple was always in place, is used to show that no significant change of the temperature reference point (the melting temperature) has occurred in either the Pt-C ingot or the Ru-C ingot, over timescales far longer than previously demonstrated and approaching that required by industry for practical use of the device.
NASA Astrophysics Data System (ADS)
Geng, J.; Bock, Y.; Fang, P.; Haase, J. S.
2012-12-01
The development of single-receiver integer ambiguity resolution in recent years has made the GPS precise point positioning (PPP) technique a valuable tool in measuring centimeter-level displacements epoch by epoch at a single station. A good application for this technique is identifying ground motions in an earthquake and tsunami early warning system. With a single receiver, PPP with ambiguity resolution can reproduce the positioning accuracy of conventional differential positioning techniques, but does not depend on any nearby reference stations which may also be displaced during an earthquake. As a result, the PPP data processing is more straightforward and efficient, suggesting that onsite displacement estimation can be carried out semi-autonomously at each GPS station and only a small amount of data, i.e. 3D displacements rather than raw measurements in the differential positioning, need to be transmitted to warning centers. Due to these merits and as part of a NASA-sponsored research effort, we have developed an operational real-time PPP system for Western North America, a vast region of tectonic deformation and significant seismic risk. A group of about 75 real-time GPS stations throughout North America and located far from western US coast (>300 km) is employed to estimate satellite-specific corrections (i.e. satellite clocks and fractional-cycle biases) with the predicted satellite orbits provided by the IGS (International GNSS Services). We note that our PPP implementation is challenged by geophysical constraints in North America and so all clients in the zone of deformation are outside the coverage of the reference network, and thus measurement errors originating in the atmosphere, satellite orbits and clocks are less correlated between the reference stations and the PPP clients. Despite this difficulty, the horizontal positioning accuracy at each PPP station is around 1 cm while the vertical better than 5 cm. This accuracy is sufficient to optimally combine the 1-Hz PPP-derived displacements with collocated (100 Hz) accelerometer data using a Kalman filter to estimate total displacement waveforms with millimeter-level accuracy. We also report on the testing of our approach in a simulated real-time environment for the 2006 Mw 6.0 Parkfield and 2010 Mw 7.2 El Mayor-Cucapah earthquakes.
N. N. Bogolubov; A. K. Prykarpatsky; U. Taneri
2009-02-25
The classical relativistic least action principle is revisited from the vacuum field theory approach. New physically motivated versions of relativistic Lorentz type forces are derived, a new relativistic hadronic string model is proposed and analyzed in detail.
Fixed Roles and Situated Actions
Murray Webster Jr; Lisa Slattery Rashotte
2009-01-01
Two visions have shaped research and theory on gender for at least 60 years. The older vision treats the genders as distinct\\u000a roles that are strongly socialized and make women and men inherently different in all circumstances. The newer one treats\\u000a gender as reflecting effects of different social structural relations, and it sees women and men as capable of displaying\\u000a wide-ranging
Vallette, Bruno
behind BV Batalin-Vilkovisky Gauge-Fixing via Homological Perturbation Theory Carlo Albert ETH Z-Vilkovisky Gauge-Fixing via Homological Perturbation Theory #12;Introduction to BV Homological Perturbation Theory¨urich, Universit´e de Gen`eve Batalin-Vilkovisky Gauge-Fixing via Homological Perturbation Theory #12;Introduction
Loffing, Florian; Hagemann, Norbert; Schorer, Jörg; Baker, Joseph
2015-04-01
A left-handers' performance advantage in interactive sports is assumed to result from their relative rarity compared to right-handers. Part of this advantage may be explained by athletes facing difficulties anticipating left-handers' action intentions, particularly when anticipation is based on kinematic cues available at an early stage of an opponent's movement. Here we tested whether the type of volleyball attack is predicted better against right- vs. left-handed opponents' movements and whether such handedness effects are evident at earlier time points in skilled players than novices. In a video-based experiment volleyball players and novices predicted the type of shot (i.e., smash vs. lob) of left- and right-handed volleyball attacks occluded at six different time points. Overall, right-handed attacks were better anticipated than left-handed attacks, volleyball players outperformed novices, and performance improved in later occlusion conditions. Moreover, in skilled players the handedness effect was most pronounced when attacks were occluded 480 ms prior to hand-ball-contact, whereas in novices it was most evident 240 ms prior to hand-ball-contact. Our findings provide further evidence of the effect of an opponent's handedness on action outcome anticipation and suggest that its occurrence in the course of an opponent's unfolding action likely depends on an observers' domain-specific skill. PMID:25689236
Tetsuya Hattori
2006-10-04
Let $W(x,y) = a x^3 + b x^4 + f_5 x^5 + f_6 x^6 + (3 a x^2)^2 y + g_5 x^5 y + h_3 x^3 y^2 + h_4 x^4 y^2 + n_3 x^3 y^3 + a_{24} x^2 y^4 + a_{05} y^5 + a_{15} x y^5 + a_{06} y^6$, and $X=\\frac{\\partial W}{\\partial x}$, $Y=\\frac{\\partial W}{\\partial y}$, where the coefficients are non-negative constants, with $a>0$, such that $X^{2}(x,x^{2})-Y(x,x^{2})$ is a polynomial of $x$ with non-negative coefficients. Examples of the 2 dimensional map $\\Phi: (x,y)\\mapsto (X(x,y),Y(x,y))$ satisfying the conditions are the renormalization group (RG) map (modulo change of variables) for the restricted self-avoiding paths on the 3 and 4 dimensional pre-gaskets. We prove that there exists a unique fixed point $(x_f,y_f)$ of $\\Phi$ in the invariant set $\\{(x,y)\\in R^2\\mid x^2\\ge y\\}\\setminus\\{0\\}$.
NASA Astrophysics Data System (ADS)
Pearce, J. V.; Elliott, C. J.; Lowe, D. H.; Failleau, G.; Deuzé, T.; Bourson, F.; Sadli, M.; Machin, G.
2014-04-01
A series of high-temperature fixed points (HTFPs) Pt-C (1738 , and Ru-C (1953 ) have been constructed at the National Physical Laboratory (NPL) and the Laboratoire National de métrologie et d'Essais and Conservatoire national des arts et métiers (LNE-Cnam). These are required for the calibration of high-temperature thermocouples in the framework of work package 6 of the European Metrology Research Programme IND01 project "HiTeMS." The goal of this work package is to establish a European capability that can determine low-uncertainty reference functions of non-standard high-temperature thermocouples. For reference functions to be widely applicable, measurements must be performed by more than one institute and preferably by more than one method. Due to the high price of the ingot materials, miniature HTFP cells are used. NPL and LNE-Cnam constructed their HTFP cells with different designs; these are described here, together with the performance of the cells using both radiation thermometry and thermocouples. The melting temperature of the Ru-C cells (for thermocouple calibrations) was determined using radiation thermometry at both NPL and LNE-Cnam, and the two results are compared. The suitability of the cells for calibration of W-Re and Rh-Ir thermocouples is evaluated, and some results are presented. Some discussion is given regarding the materials challenges when calibrating Rh-Ir thermocouples up to 2000 C.
Wason, J.M.S.; Dentamaro, A.; Eisen, T.G.
2015-01-01
Background The high failure rate in phase III oncology trials is partly because the signal obtained from phase II trials is often weak. Several papers have considered the appropriateness of various phase II end-points for individual trials, but there has not been a systematic comparison using simulated data to determine which end-point should be used in which situation. Methods In this paper we carry out simulation studies to compare the power of several Response Evaluation Criteria in Solid Tumours (RECIST) response-based end-points for one-arm and two-arm trials, together with progression-free survival (PFS) and testing the tumour-shrinkage directly for two-arm trials. We consider six scenarios: (1) short-term cytotoxic therapy; (2) continuous cytotoxic therapy; (3 + 4) cytostatic therapy; (5 + 6) delayed tumour-shrinkage effect (seen in some immunotherapies). We also consider measurement error in the assessment of tumour size. Results Measurement error affects the type-I error rate and power of single-arm trials, and the power of two-arm trials. Generally no single end-point performed well in all scenarios. Best observed response rate, PFS and directly testing the tumour-shrinkages performed best for a number of scenarios. PFS performed very poorly when the effect of the treatment was short-lived. In scenario 6, where the delay in effect was long, no end-point performed well. Conclusions A clinician setting up a phase II trial should consider the likely mechanism of action the drug will have and choose an end-point that provides high power for that scenario. Testing the difference in tumour-shrinkage is often powerful. Alternative end-points are required for therapies with a long delayed effect. PMID:25840669
Sonoda, H
2015-01-01
We introduce the concept of equivalence among Wilson actions. Applying the concept to a real scalar theory on a euclidean space, we derive the exact renormalization group transformation of K. G. Wilson, and give a simple proof of universality of the critical exponents at any fixed point of the exact renormalization group transformation. We also show how to reduce the original formalism of Wilson to the simplified formalism by J. Polchinski.
H. Sonoda
2015-08-13
We introduce the concept of equivalence among Wilson actions. Applying the concept to a real scalar theory on a euclidean space, we derive the exact renormalization group transformation of K. G. Wilson, and give a simple proof of universality of the critical exponents at any fixed point of the exact renormalization group transformation. We also show how to reduce the original formalism of Wilson to the simplified formalism by J. Polchinski.
The Anti-Inflammatory Actions of Auricular Point Acupressure for Chronic Low Back Pain.
Lin, Wei-Chun; Yeh, Chao Hsing; Chien, Lung-Chang; Morone, Natalia E; Glick, Ronald M; Albers, Kathryn M
2015-01-01
Background. Auricular point acupressure (APA) is a promising treatment for pain management. Few studies have investigated the physiological mechanisms of APA analgesics. Method. In this pilot randomized clinical trial (RCT), a 4-week APA treatment was used to manage chronic low back pain (CLBP). Sixty-one participants were randomized into a real APA group (n = 32) or a sham APA group (n = 29). Blood samples, pain intensity, and physical function were collected at baseline and after 4 weeks of treatment. Results. Subjects in the real APA group reported a 56% reduction of pain intensity and a 26% improvement in physical function. Serum blood samples showed (1) a decrease in IL-1?, IL-2, IL-6, and calcitonin gene-related peptide [CGRP] and (2) an increase in IL-4. In contrast, subjects in the sham APA group (1) reported a 9% reduction in pain and a 2% improvement in physical function and (2) exhibited minimal changes of inflammatory cytokines and neuropeptides. Statistically significant differences in IL-4 and CGRP expression between the real and sham APA groups were verified. Conclusion. These findings suggest that APA treatment affects pain intensity through modulation of the immune system, as reflected by APA-induced changes in serum inflammatory cytokine and neuropeptide levels. PMID:26170869
L. I. Petrova
2010-01-11
Physical meaning and a duality of concepts of wave function, action functional, entropy, the Pointing vector, the Einstein tensor and so on can be disclosed by investigating the state of material systems such as thermodynamic and gas dynamic systems, systems of charged particles, cosmologic systems and others. These concepts play a same role in mathematical physics. They are quantities that specify a state of material systems and also characteristics of physical fields. The duality of these concepts reveals in the fact that they can at once be both functionals and state functions or potentials. As functionals they are defined on nonintegrable manifold (for example, on tangent one), and as a state function they are defined on integrable manifold (for example, on cotangent one). The transition from functionals to state functions dicribes the mechanism of physical structure origination. The properties of these concepts can be studied by the example of entropy and action. The role of these concepts in mathematical physics and field theory will be demonstrated. Such results have been obtained by using skew-symmetric forms. In addition to exterior forms, the skew-symmetric forms, which are obtained from differential equations and, in distinction to exterior forms, are evolutionary ones and are defined on nonintegrable manifolds, were used.
NASA Astrophysics Data System (ADS)
Moreira, D. M.; Calmant, S.; Perosanz, F.; Santos, A.; Santos Da Silva, J.; Seyler, F.; Ramillien, G. L.; Monteiro, A.; Rotunno, O.; Shum, C.
2011-12-01
Applications of GNSS data is constantly being used in hydrology. One of the key applications is the characterization of river's longitudinal profiles, an information required to develop hydrological and hydrodynamic studies and to evaluate the quality of data obtained through space altimetry techniques. Some factors illustrate the challenge of establishing quality altimetry data from a GNSS receivers to obtain rivers profiles in Amazon Basin. GNSS reference network is sparse, the distance between survey points and reference stations is large, rivers have an extension of several thousands of kilometers. All these factors contribute in limiting the efficiency of classical techniques of GNSS data processing like double difference. In the present work we use the Gins-PC software developed at CNES / GRGS. We discuss the capability of the PPP kinematic with integer ambiguities fixing strategy implemented in GINS-PC in processing GPS data to calculate river's longitudinal profiles in the Amazon Basin. The profiles will be processed using data obtained from GPS receivers on boarding boats along the rivers of Amazon Basin such as Negro river, Madeira river and Amazon/Solimões river. For this purpose, field campaings were conducted between 2005 and 2010 by ANA ( Brazilian National Water Agency), CPRM (Brazilian Geologic Survey), IRD (French Institute of Research by Development), Hybam ( Hydrology of Amazon Basin), PROSUL (Research project by CNPQ/UFRJ) and FOAM (From Ocean to inland waters Altimetry Monitoring) river section project. Under the proposed framework, these profiles will be then compared with profiles obtained by water level variation data using altimetry data from tracks of the Jason-2 and ENVISAT missions. The profiles will be also used to levelling some gauge stations in Amazon Basin and gauge data will be used to obtain a temporal variation of these profiles. However some gauges are strongly affected by charge effects, mainly caused by the hydrological cycle of the Amazon basin. These effects can produce a variation of about 10 cm in amplitude of vertical coordinates also obtained by GPS. Therefore, we use GRACE data to convert the hydrologic load into crustal displacements to remove these effects.
Sexton, Alec N.; Regalado, Samuel G.; Lai, Christine S.; Cost, Gregory J.; O’Neil, Colleen M.; Urnov, Fyodor D.; Gregory, Philip D.; Jaenisch, Rudolf
2014-01-01
Telomere length homeostasis is essential for the long-term survival of stem cells, and its set point determines the proliferative capacity of differentiated cell lineages by restricting the reservoir of telomeric repeats. Knockdown and overexpression studies in human tumor cells showed that the shelterin subunit TPP1 recruits telomerase to telomeres through a region termed the TEL patch. However, these studies do not resolve whether the TPP1 TEL patch is the only mechanism for telomerase recruitment and whether telomerase regulation studied in tumor cells is representative of nontransformed cells such as stem cells. Using genome engineering of human embryonic stem cells, which have physiological telomere length homeostasis, we establish that the TPP1 TEL patch is genetically essential for telomere elongation and thus long-term cell viability. Furthermore, genetic bypass, protein fusion, and intragenic complementation assays define two distinct additional mechanisms of TPP1 involvement in telomerase action at telomeres. We demonstrate that TPP1 provides an essential step of telomerase activation as well as feedback regulation of telomerase by telomere length, which is necessary to determine the appropriate telomere length set point in human embryonic stem cells. These studies reveal and resolve multiple TPP1 roles in telomere elongation and stem cell telomere length homeostasis. PMID:25128433
John E. Mitchell
1997-01-01
Branch and cut methods for integer programming problems solve a sequence of linear programming problems. Traditionally, these linear programming relaxations have been solved using the simplex method. The reduced costs available at the optimal solution to a relaxation may make it possible to fix variables at zero or one. If the solution to a relaxation is fractional, additional constraints can
ERIC Educational Resources Information Center
Zambrana, Imac M.; Ystrom, Eivind; Schjolberg, Synnve; Pons, Francisco
2013-01-01
This study examined whether poor pointing gestures and imitative actions at 18 months of age uniquely predicted late language production at 36 months, beyond the role of poor language at 18 months of age. Data from the Norwegian Mother and Child Cohort Study were utilized. Maternal reports of the children's nonverbal skills and language were…
ERIC Educational Resources Information Center
Bonnet, Lauren Kravetz
2012-01-01
This single-subject research study was designed to examine the effects of point-of-view video modeling (POVM) on the symbolic play actions and play-associated language of four preschool students with autism. A multiple baseline design across participants was conducted in order to evaluate the effectiveness of using POVM as an intervention for…
Karmi, S.
1996-05-24
This Decision Document discusses the selection of no further action as the recommended action for two sites located at the Bullen Point radar installation. The United States Air Force (Air Force) completed a Remedial Investigation/Feasibility Study and a Risk Assessment for the five sites located at the Bullen Point installation (U.S. Air Force 1996a,b). Based on the findings of these activities, two sites are recommended for no further action. Sites at the Bullen Point radar installation recommended for no further action are: Old Landfill/Dump Site East (LF06) and Drum Storage Area (SS10).
Karmi, S.
1996-06-03
This Decision Document discusses the selection of no further action as the recommended action for four sites located at the Oliktok Point radar installation. The United States Air Force (Air Force) completed a Remedial Investigation/Feasibility Study and a Risk Assessment for the eight sites located at the Oliktok Point installation (U.S. Air Force 1996a,b). Based on the findings of these activities, four sites are recommended for no further action.
NASA Astrophysics Data System (ADS)
Lavin, Alicia; Cano, Daniel; González-Pola, Cesar; Tel, Elena; Rodriguez, Carmen; Ruiz, Manuel; Somavilla, Raquel
2015-04-01
Long term time series are an important tool for increasing the knowledge of ocean processes as well as for studying water masses variability in different time scales and changes and tendencies in marine ecosystems. Time series has been classically obtained by oceanographic ships that regularly cover standard sections and stations. From 1991, shelf and slope waters of the Southern Bay of Biscay are regularly sampled in a monthly hydrographic line north of Santander to a depth of 1000 m in early stages and for the whole water column down to 2580 m in recent times. Nearby, in June 2007, the IEO deployed an oceanic-meteorological buoy (AGL Buoy, 43° 50.67'N; 3° 46.20'W, and 40 km offshore, www.boya-agl.st.ieo.es). The long-term hydrographical record have allowed to define the seasonality, trends, and interannual variability at all levels, including the mixing layer and the main water masses North Atlantic Central Water and Mediterranean Water. The relation of these changes with high frequency surface conditions has been examined using the AGL buoy data from 2007 as well as satellite and reanalysis data. On that context and using that combination of sources, some products and quality controlled series of high interest and utility for scientific purposes have been developed and are offered hourly in the web page. Main products obtained are: SST and SSS anomalies, wave significant height character with respect to monthly average, and currents with respect to seasonal averages. Ocean-atmosphere heat fluxes (latent and sensible) are computed from the buoy atmospheric and oceanic measurements. Estimations of the mixed layer depth and bulk series at different water levels are provided in a monthly basis. Quality controlled series are provided for sea surface salinity, oxygen and chlorophyll data. Some sensors are particularly affected by biofouling, and monthly visits to the buoy permit to follow these sensors behaviour. Chlorophyll-fluorescence sensor is the main concern, but Dissolved Oxygen sensor is also problematic. Periods of realistic smooth variations present strong offset that is corrected based on the Winkler analysis of water samples. The incorporation of these observatories on larger scale research programs, as done in 2003 in the framework of the VACLAN and COVACLAN projects, is important in order to provide them with a larger spatial dimension and maximize its utility for process-oriented studies. In 2003, the Santander section was extended 90 miles offshore in the framework of a large-scale hydrographic and circulation monitoring program. Partnerships in a large EU project as FixO3 has provided tools for coordination, homogenization and data validation as well as improve the use of chemical-biological data.
Davis, Konrad; Helman, Donald; Abadie, Jude
2014-01-01
Introduction: Forward deployed military medical units can provide sophisticated medical care with limited resources. Point-of-Care Testing (POCT) may facilitate care and expedite diagnosis. This study assessed the accuracy of results for POCT for non-serum samples (pleural, peritoneal, and cerebrospinal fluid) using iSTAT and Piccolo hand-held devices compared with results obtained using a hospital chemistry analyzer. Methods: Pleural, peritoneal, and cerebrospinal fluids obtained during routine care were simultaneously analyzed on a Vitros 5600 automated clinical chemistry hospital analyzer, iSTAT, and Piccolo POCT devices. Results: POCT results were highly correlated with the Vitros 5600 for pleural fluid LDH, glucose, and triglycerides (TG); for peritoneal fluid bilirubin, TG, glucose, albumin, and protein; and glucose for cerebrospinal fluid. Conclusion: POCT results for non-serum samples from pleural, peritoneal, and cerebrospinal fluid correlate with standard hospital chemistry analysis. The results of this study demonstrate potential for possible new diagnostic roles for POCT in resource-limited environments. PMID:25285247
NASA Astrophysics Data System (ADS)
Pavese, Franco
2011-10-01
The expression of uncertainty in the field of metrology is based, since 1993, on the Guide to the Expression of Uncertainty in Measurement. According to this, 'it is assumed that the results of a measurement have been corrected for all recognized significant systematic effects'. Since the International Temperature Scale of 1990 considers the substances used for the realization of the 'fixed points' to be ideally pure, to fully implement the intent of the GUM corrections should be applied for any chemical impurities that affect the value of the measurand. The present paper aims at reviewing an aspect that must be tackled to arrive to reliable and scientifically sound corrections: the use of an appropriate statistical method. In addition to the SIE, OME and hybrid methods recommended by the CCT, two new approaches are proposed in this paper, called one-sided OME and Average Overall Estimate (AOE). They are illustrated and their merits compared with the previous one, by applying them for the correction of the measured values of the triple-point temperature of the four gaseous substances (hydrogen, neon, oxygen and argon) used for the realization of the ITS-90 reference points in the range 13.8 K to 273.16 K. Some suggestions are drawn from the resulting evidence.
Lynn Kidman
2008-10-01
This document constitutes an addendum to the July 1999, Closure Report for Corrective Action Unit 423: Area 3 Building 0360 Underground Discharge Point, Tonopah Test Range, Nevada as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modification document, this addendum consists of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the cancellation of the UR for CAS 03-02-002-0308, Underground Discharge Point. This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at the site above the risk-based FALs. Requirements for inspecting and maintaining this UR will be canceled, and the postings and signage at this site will be removed. Fencing and posting may be present at this site that are unrelated to the FFACO UR such as for radiological control purposes as required by the NV/YMP Radiological Control Manual (NNSA/NSO, 2004f). This modification will not affect or modify any non-FFACO requirements for fencing, posting, or monitoring at this site.
Suh, J; Shaw, M D; Leduc, H G; Weinstein, A J; Schwab, K C
2012-12-12
We report the results of back-action evading experiments utilizing a tightly coupled electro-mechanical system formed by a radio frequency micromechanical resonator parametrically coupled to a NbTiN superconducting microwave resonator. Due to excess dissipation in the microwave resonator, we observe a parametric instability induced by a thermal shift of the mechanical resonance frequency. In light of these measurements, we discuss the constraints on microwave dissipation needed to perform BAE measurements far below the zero-point level. PMID:23134089
NASA Astrophysics Data System (ADS)
Hao, Xiaopeng; McEvoy, Helen; Machin, Graham; Yuan, Zundong; Wang, Tiejun
2013-07-01
National Institute of Metrology, China (NIM) and National Physical Laboratory, UK (NPL) blackbody cavities based on the ITS-90 freezing points of In, Sn, Zn and Al have been compared by radiation thermometry. The average differences between In, Sn and Zn, measured by NPL InGaAs radiation thermometer, are 5.3, 2.2 and -7.3 mK, respectively, and the average differences between Sn, Zn and Al, measured by NIM InGaAs radiation thermometer, are 1.4, -5.8 and 13.7 mK, respectively. These differences are well within the uncertainties of the comparison. The NPL blackbody reference sources from 156 °C to 1000 °C were verified using both the NPL and the NIM InGaAs thermometers calibrated at the fixed points. The differences between the radiance temperature of the sources and the temperature measured by the contact sensor within the source are generally within 0.1 K.
NASA Astrophysics Data System (ADS)
Nedialkov, Sasho; Bosma, Rien; Dierikx, Erik
2013-01-01
A bilateral comparison has been organized between VSL, The Netherlands, and BIM, Bulgaria, of the realisations of the international temperature scale ITS-90 at the fixed points of Hg, H2O, Ga, In, Sn and Zn using a long-stem SPRT of very good stability as the transfer device. This comparison is registered as EURAMET project T-K3.1 in the BIPM key comparison database and its results are linked to those of key comparison CCT-K3. This comparison was organized in the framework of Phare project BG 2005/017-353.02.02, Lot 1, and is in this framework financed by the EU. This project ran from March 2008 to the end of February 2009. For all points of the measurements, a good agreement between the results obtained by BIM and in CCT-K3 could be demonstrated. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Holographic Fermionic Fixed Points in d=3
Joshua L. Davis; Hamid Omid; Gordon W. Semenoff
2011-07-21
We present a top-down string theory holographic model of strongly interacting relativistic 2+1-dimensional fermions, paying careful attention to the discrete symmetries of parity and time reversal invariance. Our construction is based on probe $D7$-branes in $AdS_5 \\times S^5$, stabilized by internal fluxes. We find three solutions, a parity and time reversal invariant conformal field theory which can be viewed as a particular deformation of Coulomb interacting graphene, a parity and time reversal violating but gapless field theory and a system with a parity and time reversal violating charge gap. We show that the Chern-Simons-like electric response function, which is generated perturbatively at one-loop order by parity violating fermions and which is protected by a no-renormalization theorem at orders beyond one loop, indeed appears with the correctly quantized coefficient in the charge gapped theory. In the gapless parity violating solution, the Chern-Simons response function obtains quantum corrections which we compute in the holographic theory.
Fixed-Point-Like Theorems on Subspaces
Bich, Philippe; Cornet, Bernard
2004-08-26
, such that ?x ?M, [ Fki (x) #6;= ? ] =? [ ?y ? Fˆki (x), ???R, ?y ? F k i (x) ] . (3.19) Proof of Claim 3.5. Let i? I and k ? {1, . . . ,ki}. We distinguish two cases. Assume first that Fki is l.s.c. Let U k i = {x ?M | F k i (x) #6;= ?}. Then U k i is an open... = {?(cos t, sin t) | ? ? R}, for some t ? [0,?[. We define the correspondence F from M to R2 by F(D0) = R× {1} and F(Dt) = Dt ? (R× {1}) + {(1,0)} if t ?]0,?[. We let the reader check that for every open set U ? R2, the set {x ?M | F(x) ? U} is open...
Supersymmetric D3 brane action in AdS_5 x S^5
R. R. Metsaev; A. A. Tseytlin
1998-06-14
We find the space-time supersymmetric and kappa-invariant action for a D3-brane propagating in the AdS_5 x S^5 background. As in the previous construction of the fundamental string action in this maximally supersymmetric string vacuum the starting point is the corresponding superalgebra su(2,2|4). We comment on the super Yang-Mills interpretation of the gauge-fixed form of the action.
Smith, Dean O.
1980-01-01
1. In the crayfish, regions of axonal bifurcation where action potential propagation failed during repetitive activity were visualized using modulation-contrast optics. To determine if a reduced safety factor for conduction at the branch sites has a morphological basis, the geometrical ratio (GR) of axon diameters, where GR = (d13/2+d23/2)/dp3/2, was calculated; d1, d2, and dp are the diameters of the two daughter branches and the parent axon, respectively. 2. Values of GR at sites of conduction block were usually slightly higher than 1, indicating a small drop in safety factor; however the values were well below the level at which failure might occur due to an impedance mismatch. 3. Calculated values of GR were generally higher in the most peripheral axon regions where propagation was observed to block most readily. 4. Short collaterals containing numerous synaptic vesicles and apparent release sites were observed to have relatively low values of GR (about 0.8); collaterals containing densely populated mitochondria were characterized by relatively high values of GR (about 1.3). 5. It is concluded that the morphological characteristics of the axon in the branching region are conducive to an inherent low safety factor for conduction, but that they cannot play a major role in block development. ImagesPLATE 4PLATE 1PLATE 2PLATE 3 PMID:7411432
The action principle for dissipative systems
Matheus J. Lazo; Cesar E. Krumreich
2014-12-16
In the present work we redefine and generalize the action principle for dissipative systems proposed by Riewe by fixing the mathematical inconsistencies present in the original approach. In order to formulate a quadratic Lagrangian for non-conservative systems, the Lagrangian functions proposed depend on mixed integer order and fractional order derivatives. As examples, we formulate a quadratic Lagrangian for a particle under a frictional force proportional to the velocity, and to the classical problem of an accelerated point charge.
Mihalas, Anca B.; Araki, Yoichi; Huganir, Richard L.
2013-01-01
Homeostatic responses critically adjust synaptic strengths to maintain stability in neuronal networks. Compensatory adaptations to prolonged excitation include induction of Polo-like kinases (Plks) and degradation of spine-associated Rap GTPase-activating protein (SPAR) to reduce synaptic excitation, but mechanisms that limit overshooting and allow refinement of homeostatic adjustments remain poorly understood. We report that Plks produce canonical pathway-mediated activation of the nuclear factor ?B (NF-?B) transcription factor in a process that requires the kinase activity of Plks. Chronic elevated activity, which induces Plk expression, also produces Plk-dependent activation of NF-?B. Deficiency of NF-?B, in the context of exogenous Plk2 expression or chronic elevated neuronal excitation, produces exaggerated homeostatic reductions in the size and density of dendritic spines, synaptic AMPA glutamate receptor levels, and excitatory synaptic currents. During the homeostatic response to chronic elevated activity, NF-?B activation by Plks subsequently opposes Plk-mediated SPAR degradation by transcriptionally upregulating SPAR in mouse hippocampal neurons in vitro and in vivo. Exogenous SPAR expression can rescue the overshooting of homeostatic reductions at excitatory synapses in NF-?B-deficient neurons responding to elevated activity. Our data establish an integral feedback loop involving NF-?B, Plks, and SPAR that regulates the end point of homeostatic synaptic adaptation to elevated activity and are the first to implicate a transcription factor in the regulation of homeostatic synaptic responses. PMID:24133254
Classically Perfect Gauge Actions on Anisotropic Lattices
Philipp Rufenacht; Urs Wenger
2001-08-06
We present a method for constructing classically perfect anisotropic actions for SU(3) gauge theory based on an isotropic Fixed Point Action. The action is parametrised using smeared (``fat'') links. The construction is done explicitly for anisotropy $\\xi=a_s/a_t=2$ and 4. The corresponding renormalised anisotropies are determined using the torelon dispersion relation. The renormalisation of the anisotropy is small and the parametrisation describes the true action well. Quantities such as the static quark-antiquark potential, the critical temperature of the deconfining phase transition and the low-lying glueball spectrum are measured on lattices with anisotropy $\\xi=2$. The mass of the scalar $0^{++}$ glueball is determined to be 1580(60) MeV, while the tensor $2^{++}$ glueball is at 2430(60) MeV.
Democratic superstring field theory: gauge fixing
NASA Astrophysics Data System (ADS)
Kroyter, Michael
2011-03-01
We show that a partial gauge fixing of the NS sector of the democratic-picture superstring field theory leads to the non-polynomial theory. Moreover, by partially gauge fixing the Ramond sector we obtain a non-polynomial fully RNS theory at pictures 0 and 1/2 . Within the democratic theory and in the partially gauge fixed theory the equations of motion of both sectors are derived from an action. We also discuss a representation of the non-polynomial theory analogous to a manifestly two-dimensional representation of WZW theory and the action of bosonic pure-gauge solutions. We further demonstrate that one can consistently gauge fix the NS sector of the democratic theory at picture number -1. The resulting theory is new. It is a {mathbb{Z}_2} dual of the modified cubic theory. We construct analytical solutions of this theory and show that they possess the desired properties.
Moffat, Ivy; Chepelev, Nikolai L; Labib, Sarah; Bourdon-Lacombe, Julie; Kuo, Byron; Buick, Julie K; Lemieux, France; Williams, Andrew; Halappanavar, Sabina; Malik, Amal I; Luijten, Mirjam; Aubrecht, Jiri; Hyduke, Daniel R; Fornace, Albert J; Swartz, Carol D; Recio, Leslie; Yauk, Carole L
2015-01-01
Toxicogenomics is proposed to be a useful tool in human health risk assessment. However, a systematic comparison of traditional risk assessment approaches with those applying toxicogenomics has never been done. We conducted a case study to evaluate the utility of toxicogenomics in the risk assessment of benzo[a]pyrene (BaP), a well-studied carcinogen, for drinking water exposures. Our study was intended to compare methodologies, not to evaluate drinking water safety. We compared traditional (RA1), genomics-informed (RA2) and genomics-only (RA3) approaches. RA2 and RA3 applied toxicogenomics data from human cell cultures and mice exposed to BaP to determine if these data could provide insight into BaP's mode of action (MOA) and derive tissue-specific points of departure (POD). Our global gene expression analysis supported that BaP is genotoxic in mice and allowed the development of a detailed MOA. Toxicogenomics analysis in human lymphoblastoid TK6 cells demonstrated a high degree of consistency in perturbed pathways with animal tissues. Quantitatively, the PODs for traditional and transcriptional approaches were similar (liver 1.2 vs. 1.0 mg/kg-bw/day; lungs 0.8 vs. 3.7 mg/kg-bw/day; forestomach 0.5 vs. 7.4 mg/kg-bw/day). RA3, which applied toxicogenomics in the absence of apical toxicology data, demonstrates that this approach provides useful information in data-poor situations. Overall, our study supports the use of toxicogenomics as a relatively fast and cost-effective tool for hazard identification, preliminary evaluation of potential carcinogens, and carcinogenic potency, in addition to identifying current limitations and practical questions for future work. PMID:25605026
Labib, Sarah; Bourdon-Lacombe, Julie; Kuo, Byron; Buick, Julie K.; Lemieux, France; Williams, Andrew; Halappanavar, Sabina; Malik, Amal; Luijten, Mirjam; Aubrecht, Jiri; Hyduke, Daniel R.; Fornace, Albert J.; Swartz, Carol D.; Recio, Leslie; Yauk, Carole L.
2015-01-01
Toxicogenomics is proposed to be a useful tool in human health risk assessment. However, a systematic comparison of traditional risk assessment approaches with those applying toxicogenomics has never been done. We conducted a case study to evaluate the utility of toxicogenomics in the risk assessment of benzo[a]pyrene (BaP), a well-studied carcinogen, for drinking water exposures. Our study was intended to compare methodologies, not to evaluate drinking water safety. We compared traditional (RA1), genomics-informed (RA2) and genomics-only (RA3) approaches. RA2 and RA3 applied toxicogenomics data from human cell cultures and mice exposed to BaP to determine if these data could provide insight into BaP's mode of action (MOA) and derive tissue-specific points of departure (POD). Our global gene expression analysis supported that BaP is genotoxic in mice and allowed the development of a detailed MOA. Toxicogenomics analysis in human lymphoblastoid TK6 cells demonstrated a high degree of consistency in perturbed pathways with animal tissues. Quantitatively, the PODs for traditional and transcriptional approaches were similar (liver 1.2 vs. 1.0 mg/kg-bw/day; lung 0.8 vs. 3.7 mg/kg-bw/day; forestomach 0.5 vs. 7.4 mg/kg-bw/day). RA3, which applied toxicogenomics in the absence of apical toxicology data, demonstrates that this approach provides useful information in data-poor situations. Overall, our study supports the use of toxicogenomics as a relatively fast and cost-effective tool for hazard identification, preliminary evaluation of potential carcinogens, and carcinogenic potency, in addition to identifying current limitations and practical questions for future work. PMID:25605026
A proper fixed functional for four-dimensional Quantum Einstein Gravity
NASA Astrophysics Data System (ADS)
Demmel, Maximilian; Saueressig, Frank; Zanusso, Omar
2015-08-01
Realizing a quantum theory for gravity based on Asymptotic Safety hinges on the existence of a non-Gaussian fixed point of the theory's renormalization group flow. In this work, we use the functional renormalization group equation for the effective average action to study the fixed point underlying Quantum Einstein Gravity at the functional level including an infinite number of scale-dependent coupling constants. We formulate a list of guiding principles underlying the construction of a partial differential equation encoding the scale-dependence of f( R)-gravity. We show that this equation admits a unique, globally well-defined fixed functional describing the non-Gaussian fixed point at the level of functions of the scalar curvature. This solution is constructed explicitly via a numerical double-shooting method. In the UV, this solution is in good agreement with results from polynomial expansions including a finite number of coupling constants, while it scales proportional to R 2, dressed up with non-analytic terms, in the IR. We demonstrate that its structure is mainly governed by the conformal sector of the flow equation. The relation of our work to previous, partial constructions of similar scaling solutions is discussed.
Lattice QCD with fixed topology
Hidenori Fukaya
2006-06-26
The overlap Dirac operator, which satisfies the Ginsparg-Wilson relation, realizes exact chiral symmetry on the lattice without any unphysical doubler modes. To perform the path integrals, one should, however, note that the overlap fermion determinant has discontinuities where the topology is ill-defined, its locality is doubtful, and the numerical cost is suddenly enhanced. An interesting solution would be to concentrate on a fixed topological sector in the full configuration space. In this thesis, we test a gauge action which automatically satisfies Luescher's admissibility condition, as well as an additional (large) negative mass Wilson fermion action in the quenched study (with no light quark). Both of them would keep the topology along the HMC simulations. The quark potential and the topology stability are investigated with different lattice sizes and different couplings. The results of quenched QCD in the $\\epsilon$-regime are also presented as an example of the lattice studies with fixed topology. Remarkable quark mass and topology dependences of meson correlators allow us to determine the fundamental parameters of the effective theory, in which the exact chiral symmetry with the Ginsparg Wilson relation plays a crucial role.
NSDL National Science Digital Library
2008-01-01
Ziff needs you to help him fix his buildings! With your tool bag, you will fix windows, doors, and roofs. Sounds easy right? It may not be as easy as you may think. You will need to use what you have learned in math class to make new ones that fit just right. You will get your own Cyberchase Master Builder certificate when the job is done!
NASA Astrophysics Data System (ADS)
Reaney, S. M.
2014-12-01
Catchment systems deliver many benefits to society and ecology but also produce a range of undesirable externalities including flooding, diffuse pollution from agriculture, forestry and urban areas and the export of FIOs. These diffuse pressures are coupled with increasing stream temperature pressures on river from projected climate change. These pressures can be reduced through actions at the landscape scale but are often tackled individually. Any intervention may have benefits for other pressures and hence the challenge is to consider all of the different pressures simultaneously to find solutions with high levels of cross-pressure benefits. The general approach taken within this research has been to use simple but spatially distributed models to predict the pattern of each of the pressures at the landscape scale. These models follow a minimum information requirement approach along the lines of the SCIMAP modelling approach (www.scimap.org.uk). This approach aims to capture the key features of the processes in relative rather than an absolute sense and hence is good at determining key locations to act within a landscape for maximum benefit. The core of the approach is to define the critical sources areas for each pressure based on the analysis of the pattern of the pressure in the landscape and the connectivity from the sources areas to the rivers and lakes. To identify the optimal locations with the landscape for mitigation actions, the benefit of a mitigation action at each location in the landscape needs to be considered. However, as one action has been made, it may change the suitability of other locations in the landscape. For example, as tree cover reduces the temperature in one river reach, the impacts of this cooling are transported downstream with the flow. Therefore, actions need to be considered in sets across multiple sites and objectives to identify the optimal actions set. These modelling results are integrated into a decision support tool which allows the user to explore the implications of considering an individual pressure as opposed to the set of pressures. This is achieved by allowing the user to change the importance of different pressures to identify the optimal locations for a custom combination of pressures. For example, reductions in flood risk can be prioritized over reductions in fine sediment.
Ban, T.E.; Rao, A.D.
1981-03-31
A fixed sulfur fuel is produced by proportioning sulfur-bearing coal and limestone in amounts which will cause the calcium in the limestone to react with a large amount of sulfur in the coal. The proportioned mixture is ground and blended and then balled or compacted to form pellets. By means of either a carbonizing or pyrolyzing technique conducted in a traveling grate machine, where the pellets are heated to at least 800* F., the coal is pyrolyzed or carbonized, the limestone is calcined, and the sulfur is fixed in a calcium compound which remains stable in the ash after the pellets are burned as a fuel.
The theoretical static response of electrostatic fixed fixed beam microactuators
Ki Bang Lee
2008-01-01
A closed-form solution for the static response of fixed fixed beam actuators to an applied voltage has been successfully derived to understand the nonlinear behavior of the actuator and to provide a guideline for the actuator design. A cubic force balance equation is obtained by applying the Galerkin method to the differential equation for the fixed fixed beam actuator under
Psychometric curves describe action discrimination in humans.
Orban, Guy; Platonov, Artem
2015-09-01
Action observation is a visual function of a great importance from both the ethological and social point of view. Recently, a number of studies provided new insights into its functional organization as a three-level cortical network encompassing in human and non-human primates occipito-temporal, parietal and premotor regions. However, there is still no general framework which would allow to establish a relationship between neuronal activity in these areas and its behavioral correlates. Demonstrating that general psychophysical laws are also applicable to the visual processing of observed actions could provide us with such a framework. We reasoned that changing the amount of dynamic noise in action movies would produce behavioral responses in human subjects qualitatively similar to the classical psychometric curves. To test this hypothesis, we presented human subjects (n=4) with the movies (2 sec) in which they had to discriminate between the two different hand-actions (rolling and rotation) in a two-alternative forced-choice task. The movies were randomly presented in 5 different fronto-parallel positions and at 2 depths. On every frame in each movie, a certain percentage of random dot-pixel pairs separated by a distance randomly chosen from within a fixed interval were scrambled. By manipulating the percentage of scrambled dot pairs, we created 6 noise levels from 60% (i.e. 60% of dots on each frame were scrambled) to 100%. Our data indicate that the amount of noise in action movies attenuated the ability of our subjects to discriminate between the two actions tested, such that the observers' performance could be described by the classical logistic regression. This psychometric curve suggests that action discrimination follows general rules described in classical visual psychophysics. One implication is that by changing the input strength in action movies can be used to manipulate the activity in single cells and neural populations. Meeting abstract presented at VSS 2015. PMID:26326249
Riedel, H-P; Ellger-Rüttgardt, S; Karbe, H; Niehaus, M; Rauch, A; Schian, H-M; Schmidt, C; Schott, T; Schröder, H; Spijkers, W; Wittwer, U
2009-12-01
Established by the Federal Ministry of Labour and Social Affairs (BMAS) in October 2007, the Scientific Expert Group RehaFutur had been commissioned to elaborate cornerstones for the medium- and long-term development of vocational rehabilitation of adults with disabilities (re-integration). Initial questions inter alia were as follows: Which function should vocational rehabilitation have in a service- and knowledge-oriented working world that will increasingly be affected by demographic change? How can disabled persons' right to occupational participation by way of vocational rehabilitation, a right stipulated both under the German constitution and in German law, be realized as needed also in the future? Various fields of action have been derived on the basis, for one, of an investigation of the factors, social law, social and education policy as well as European, influencing vocational rehabilitation and, for the other, of an evaluation of current labour market and demographic developments. Dealt with in the fields of action outlined are the aspects: equitable opportunities of access, developmental and needs orientation, closeness to the real occupational and working world, as well as the role of self-determination and self-responsibility. The fields of action are to be understood as framework concept for shaping a cross-actor innovation process. Sustainable vocational rehabilitation is characterized in particular by the fact that it is specifically targeted at promoting disabled persons' self-determination and self-responsibility actively using these in the process and that it strengthens an independent lifestyle, ensures social participation by inclusive structures; also, it facilitates continued participation in working life by ongoing education involving holistic development of professional and personal competencies oriented towards the individual's resources and potentials, safeguarding it by systematic networking with companies. The concept presented for vocational rehabilitation of adults with disabilities encompasses a change of paradigms which service carriers and providers will have to face jointly and including the service users, the rehabilitants. PMID:20069522
Covariant computation of effective actions in Horava-Lifshitz gravity
D'Odorico, Giulio; Saueressig, Frank
2015-01-01
We initiate the systematic computation of the heat-kernel coefficients for Laplacian operators obeying anisotropic dispersion relations in curved spacetime. Our results correctly reproduce the limit where isotropy is restored and special anisotropic cases considered previously in the literature. Subsequently, the heat kernel is used to derive the scalar-induced one-loop effective action and beta functions of Horava-Lifshitz gravity. We identify the Gaussian fixed point which is supposed to provide the UV completion of the theory. In the present setting, this fixed point acts as an infrared attractor for the renormalization group flow of Newton's constant and the high-energy phase of the theory is screened by a Landau pole. We comment on the consequences of these findings for the renormalizability of the theory.
"Wuwei" (Non-Action) Philosophy and Actions: Rethinking "Actions" in School Reform
ERIC Educational Resources Information Center
Moon, Seungho
2015-01-01
This inquiry aims to enrich conversation regarding school reform. The author asks about what other discourses are possible when the action-oriented question of how to "act" is a major approach to "fix" current educational problems. Drawing from Taoist philosophy of "wuwei" (non-action), the author provides a frame to…
NASA Technical Reports Server (NTRS)
Fenn, D. B.; Viterna, L. A.
1978-01-01
Wind turbines designed for fixed pitch operation offer potential reductions in the cost of the machine by eliminating many costly components. It was shown that a rotor can be designed which produces the same energy annually as Mod-0 but which regulates its power automatically by progressively stalling the blades as wind speed increases. Effects of blade twist, taper, root cutout, and airfoil shape on performance are discussed as well as various starting technqiues.
22. VIEW OF FIXED SPAN SUBSTRUCTURE, EAST SPAN, SHOWING CANTILEVEREDBEAM ...
22. VIEW OF FIXED SPAN SUBSTRUCTURE, EAST SPAN, SHOWING CANTILEVERED-BEAM SIDEWALK SUPPORTS, LONGITUDINAL GIRDER AND TRANSVERSE ROADBED BEAMS, LOOKING SOUTHEAST - Congress Street Bascule Bridge, Spanning Fort Point Channel at Congress Street, Boston, Suffolk County, MA
41. Detail showing meeting of two fixed land span segments, ...
41. Detail showing meeting of two fixed land span segments, bridge land span at left, viaduct at right. VIEW NORTH - Broadway Bridge, Spanning Foundry Street, MBTA Yard, Fort Point Channel, & Lehigh Street, Boston, Suffolk County, MA
Exterior building details of Building A; east façade: fixed fiveoverfive ...
Exterior building details of Building A; east façade: fixed five-over-five wood windows with five-light hoppers with concrete sills; westerly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA
Fixed target facility at the SSC
Loken, S.C.; Morfin, J.G.
1985-01-01
The question of whether a facility for fixed target physics should be provided at the SSC must be answered before the final technical design of the SSC can be completed, particularly if the eventual form of extraction would influence the magnet design. To this end, an enthusiastic group of experimentalists, theoreticians and accelerator specialists have studied this point. The accelerator physics issues were addressed by a group led by E. Colton whose report is contained in these proceedings. The physics addressable by fixed target was considered by many of the Physics area working groups and in particular by the Structure Function Group. This report is the summary of the working group which considered various SSC fixed target experiments and determined which types of beams and detectors would be required. 13 references, 5 figures.
Facilitation in action research
Chrysoula Kosmidou; Robin Usher
1991-01-01
What is it that forms our understanding of action research? In trying to answer this question we take as our Starting-point the existence of certain inter-related theorizations and practices, things which are said and done, that \\
Non-perturbative analysis of the Gribov-Zwanziger action
Huber, Markus Q. [Physikalisch-Theoretisches Institut, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Alkofer, Reinhard [Institut fuer Physik, Universitaet Graz, Universitaetsplatz 5, 8010 Graz (Austria); Sorella, Silvio P. [Departamento de Fisica Teorica, Instituto de Fisica, UERJ - Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier 524, 20550-013 Maracana, Rio de Janeiro (Brazil)
2011-05-23
In the non-perturbative regime the usual gauge fixing is not sufficient due to the Gribov problem. To deal with it one can restrict the integration in the path integral to the first Gribov region by using the Gribov-Zwanziger action. In its local form it features additional auxiliary fields which mix with the gluon at the two-point level. We present an explicit infrared analysis of this action. We show that from the two possible scaling solutions obtained previously only one remains: It coincides exactly with the results from the Faddeev-Popov action, i.e., the ghost propagator is infrared enhanced and the gluon propagator infrared suppressed and the corresponding power law behavior is described by only one parameter {kappa} = 0.5953.... This corroborates the argument by Zwanziger that for functional equations it suffices to take into account the appropriate boundary conditions and no explicit restriction in the path integral measure is required.
Action and entanglement in gravity and field theory.
Neiman, Yasha
2013-12-27
In nongravitational quantum field theory, the entanglement entropy across a surface depends on the short-distance regularization. Quantum gravity should not require such regularization, and it has been conjectured that the entanglement entropy there is always given by the black hole entropy formula evaluated on the entangling surface. We show that these statements have precise classical counterparts at the level of the action. Specifically, we point out that the action can have a nonadditive imaginary part. In gravity, the latter is fixed by the black hole entropy formula, while in nongravitating theories it is arbitrary. From these classical facts, the entanglement entropy conjecture follows by heuristically applying the relation between actions and wave functions. PMID:24483789
Multiple Contributors
1988-01-01
. Gina was a Trek fan and artist, a good friend who taped S&H episodes for me from her station in Delaware and lent a helping hand at the Paul Muni Special con. I appreciate everyone's patience and kind words while I've taken time off from fanac... your FIX! , ? ? l~~S LE l"l'ERS OF COMMENT LoC's are welcome ... encouraged ! The only editorial guideline I'd like to offer is: be constructive. Let's keep it friendly and remember to allow for differences in individual tastes. Please keep your...
Fixed sagittal plane imbalance.
Savage, Jason W; Patel, Alpesh A
2014-12-01
Study Design?Literature review. Objective?To discuss the evaluation and management of fixed sagittal plane imbalance. Methods?A comprehensive literature review was performed on the preoperative evaluation of patients with sagittal plane malalignment, as well as the surgical strategies to address sagittal plane deformity. Results?Sagittal plane imbalance is often caused by de novo scoliosis or iatrogenic flat back deformity. Understanding the etiology and magnitude of sagittal malalignment is crucial in realignment planning. Objective parameters have been developed to guide surgeons in determining how much correction is needed to achieve favorable outcomes. Currently, the goals of surgery are to restore a sagittal vertical axis?Fixed sagittal malalignment often requires complex reconstructive procedures that include osteotomy correction. Reestablishing harmonious spinopelvic alignment is associated with significant improvement in health-related quality-of-life outcome measures and patient satisfaction. PMID:25396111
Fixed Sagittal Plane Imbalance
Savage, Jason W.; Patel, Alpesh A.
2014-01-01
Study Design?Literature review. Objective?To discuss the evaluation and management of fixed sagittal plane imbalance. Methods?A comprehensive literature review was performed on the preoperative evaluation of patients with sagittal plane malalignment, as well as the surgical strategies to address sagittal plane deformity. Results?Sagittal plane imbalance is often caused by de novo scoliosis or iatrogenic flat back deformity. Understanding the etiology and magnitude of sagittal malalignment is crucial in realignment planning. Objective parameters have been developed to guide surgeons in determining how much correction is needed to achieve favorable outcomes. Currently, the goals of surgery are to restore a sagittal vertical axis?Fixed sagittal malalignment often requires complex reconstructive procedures that include osteotomy correction. Reestablishing harmonious spinopelvic alignment is associated with significant improvement in health-related quality-of-life outcome measures and patient satisfaction. PMID:25396111
Genn Saji [Ex-Secretariate of Nuclear Safety Commission of Japan (Japan)
2006-07-01
The author has investigated the characteristics of boron co-deposition with crud experienced in AOA and iron ferrite deposition in CDA. Corrosion product deposits found in cores with appreciable AOA have been reported in mostly nickel-based (as NiO or elemental nickel) as opposed to nickel ferrite deposits common to non-boiling cores. Significant quantities of meta-ZrO{sub 2} and nickel iron oxy-borates (bonaccordite), notably Ni{sub 2}FeBO{sub 5} have also been found in deposits on cores with AOA. On the basis of this general characterization information, the author has constructed a potential-pH diagram of Ni{sub 2}FeB(OH){sub 10}, which is a hydrated state of FeNi{sub 2}(BO{sub 3})O{sub 2} as summarized in this paper. Although preliminary, the estimated E-pH diagram suggests some interesting observation, including: growth of bonaccordite 'needles' on the clad is associated with a local anodic electrochemical reaction necessary to remove excess electrons from the system to a cathode. During the AOA cycle, the concentration of nickel and iron ions must have been unusually high as they should be for a significant amount of crud deposits. The author thinks such an acceleration of the anodic dissolution of metal cations is due to the effect of the long cell action corrosion mechanism. As early as 1949, an Italian scientist Petracchi demonstrated that electrochemical effects significantly influence the erosion rate. He constructed a flow nozzle with specimens kept under external electrical potential. Upon inducing as low as 0.1 mA/cm{sup 2} of the positive current, the erosion rates were reported drastically increased. No erosion was observed by reversing the polarity of the potential. As discussed in a companion paper also presented at this conference, the author discusses various mechanisms (electrochemical cell configurations) that induce potential differences, including those differences in ionic concentration, aeration, temperature, flow velocity, radiation and corrosion potentials. In this paper, the author discusses how these potential differences are related to the AOA/CDA issues in PWR/VVER plants. The author is calling for further verification experiments regarding this corrosion mechanism as a joint international project. (author)
Noonan, Jonathan E.; Jenkins, Alicia J.; Ma, Jian-Xing; Keech, Anthony C.; Wang, Jie Jin; Lamoureux, Ecosse L.
2013-01-01
The drug fenofibrate has received major attention as a novel medical treatment for diabetic retinopathy (DR) and other diabetes-induced microvascular complications. This interest stems from two recent large, well-designed clinical trials that demonstrated large reductions in the progression of DR and the need for laser intervention, in addition to a reduction in renal and neurological outcomes, in patients with type 2 diabetes. In both trials, the greatest benefit on DR progression was observed in those patients with DR at baseline. Originally considered a lipid-modifying drug, it now appears that multiple mechanisms may underpin the benefit of fenofibrate on diabetic microvascular end points. Fenofibrate regulates the expression of many different genes, with a range of beneficial effects on lipid control, inflammation, angiogenesis, and cell apoptosis. These factors are believed to be important in the development of DR regardless of the underlying diabetes etiology. Cell experiments have demonstrated improved survival of retinal endothelial and pigment epithelial cells in conjunction with reduced stress signaling under diabetic conditions. Further, fenofibrate improves retinal outcomes in rodent models of diabetes and retinal neovascularization. Given the results of these preclinical studies, further clinical trials are needed to establish the benefits of fenofibrate in other forms of diabetes, including type 1 diabetes. In DR management, fenofibrate could be a useful adjunctive treatment to modifiable risk factor control and regular ophthalmic review. Its incorporation into clinical practice should be continually revised as more information becomes available. PMID:24264394
Colligative properties of solutions: I. Fixed concentrations
Kenneth Alexander; Marek Biskup; Lincoln Chayes
2005-01-09
Using the formalism of rigorous statistical mechanics, we study the phenomena of phase separation and freezing-point depression upon freezing of solutions. Specifically, we devise an Ising-based model of a solvent-solute system and show that, in the ensemble with a fixed amount of solute, a macroscopic phase separation occurs in an interval of values of the chemical potential of the solvent. The boundaries of the phase separation domain in the phase diagram are characterized and shown to asymptotically agree with the formulas used in heuristic analyses of freezing point depression. The limit of infinitesimal concentrations is described in a subsequent paper.
Hall, David R. (Provo, UT); Bartholomew, David B. (Springville, UT); Moon, Justin (Bountiful, UT); Koehler, Roger O. (Provo, UT)
2009-09-08
An apparatus for fixing computational latency within a deterministic region on a network comprises a network interface modem, a high priority module and at least one deterministic peripheral device. The network interface modem is in communication with the network. The high priority module is in communication with the network interface modem. The at least one deterministic peripheral device is connected to the high priority module. The high priority module comprises a packet assembler/disassembler, and hardware for performing at least one operation. Also disclosed is an apparatus for executing at least one instruction on a downhole device within a deterministic region, the apparatus comprising a control device, a downhole network, and a downhole device. The control device is near the surface of a downhole tool string. The downhole network is integrated into the tool string. The downhole device is in communication with the downhole network.
Act of swallowing in the fixed larynx.
Krajina, Z; Vecerina, S
1976-01-01
In a 16-year-old female, complete stenosis of the larynx and hypopharynx developed as a consequence of the ingestion of lye cristals. Supraglotic laryngectomy, plastic surgery of the hypopharynx and antethoracic oesophagus were performed and the upper aero-digestive tract reconstructed. The dilated larynx remained fixed by the surrounding fibrous tissue, but the sphincteric action of the mobile vocal cords was partly salvaged. In that condition, the act of swallowing could be reestablished. The pathophysiology of this new mechanism of swallowing is discussed. PMID:1266619
Active microrheology: Fixed-velocity versus fixed-force
NASA Astrophysics Data System (ADS)
Swan, James W.; Zia, Roseanna N.
2013-08-01
In active microrheology, a probe particle is driven by an external force through a complex medium and its motion studied in order to infer properties of the embedding material. It is conducted in two limiting forms: either the probe is propelled by a fixed force, as with magnetic tweezers, or it is driven at a fixed velocity, as with optical tweezers. Recent work has shown that the mean probe motion can be interpreted as an effective material viscosity, but that this viscosity depends on whether the fixed-force or fixed-velocity mode is employed. We compute the effective viscosity probed by fixed-velocity active microrheology of a dilute colloidal dispersion. A comparison is made between this new result and the effective viscosity probed in the fixed-force mode. In the absence of hydrodynamic interactions, the particle-phase contributions to the effective viscosity for the two modes differ by exactly a factor of two. A simple scaling argument has been previously advanced to rationalize this difference: in the fixed-force mode, the probe is free to diffuse, and thus the relaxation time scale is set by the relative diffusivity between probe and bath. However, in the fixed-velocity mode, thermal motion of the probe particle is "frozen out" because the probe cannot diffuse; the relaxation rate is thus halved. The ratio of the two rates is independent of how quickly the probe particle is driven through the suspension—the extent and shape of microstructural deformation is the same for the two cases. In contrast, when the suspended particles interact hydrodynamically, the distortions to the suspension microstructure in the fixed-velocity versus fixed-force modes differ. We show that, depending on the strength of the hydrodynamic interactions, the ratio of the fixed-velocity to the fixed-force microstructural contributions to the effective viscosity may be as small as 1.3, and only approaches 2.0 when hydrodynamic interactions among the particles are negligibly weak. While this ratio varies both as a function of the strength of the deformation imposed and of the strength of hydrodynamic interactions, the fixed-velocity effective viscosity agrees qualitatively with that already measured for the fixed-force mode: the colloidal dispersion thins in the limit of weak hydrodynamic interactions; and it first thins and then thickens in the limit of strong hydrodynamic interactions, as the strength of deformation increases, recovering characteristics of shear-(force-) thinning and thickening well known in colloidal dispersions. The agreement between the two, and with traditional macrorheological approaches, shows that both fixed-force and fixed-velocity provide a useful tool for the interrogation of complex fluids.
New tests of the gauge-fixing approach to lattice chiral gauge theories
Wolfgang Bock; Maarten F. L. Golterman; Ka Chun Leung; Yigal Shamir
1999-09-14
We report on recent progress with the gauge-fixing approach to lattice chiral gauge theories. The bosonic sector of the gauge-fixing approach is studied with fully dynamical U(1) gauge fields. We demonstrate that it is important to formulate the Lorentz gauge-fixing action such that the dense set of lattice Gribov copies is removed, and the gauge-fixing action has a unique absolute minimum. We then show that the spectrum in the continuum limit contains only the desired massless photon, as expected.
UNSEPARATED PAIRS AND FIXED POINTS IN RANDOM PERMUTATIONS
McAuliffe, Jon
on the inclusion-exclusion principle, the introduction of two different Markov chains to generate uniform random chain, Chinese restaurant process, Pois- son distribution, Stein's method, commutator, smoosh, wash. PD
An Inflationary Fixed Point Operator in XQuery Loredana Afanasiev #1
Grust, Torsten
: only the seed ($seed := · · · ) and the body (rec_body(·)) are specific to the curriculum problem¨unchen IBM T.J. Watson Research Center Amsterdam, The Netherlands Munich, Germany Hawthorne, NY, USA 1 and query need. Example 1.1: The DTD of Figure 1 (taken from [4]) de- scribes recursive curriculum data
Z An Efficient Engine for Fixed points with Constraints
Borgs, Christian
Z is a pluggable and composable API for adding alternative finite table implementations and ab- stract relations for optimizations and/or additional features, we may perform various transformations on the input rules. Free). The last rule introduces another free head vari- able, which can be eliminated using the same procedure
Fixed Point Iteration for Computing the Time Elapse Operator
Sankaranarayanan, Sriram
. Sipma2 , Zohar Manna2 1 NEC Laboratories America, Princeton, NJ srirams@nec-labs.com 2 Computer Science. This is an important primitive operation for the safety analysis of continuous and hybrid systems. In this paper we design a time elapse operator that computes a symbolic over-approximation of time solutions
On the uniqueness of loopy belief propagation fixed points
Heskes, Tom
those for convexity of the Bethe free energy. We compare them with (a strength ened version of algorithms as well as for other approximate free energies. 1 Introduction Loopy belief propagation is Pearl belief propagation correspond to extrema of the socalled Bethe free energy (Yedidia, 1 #12; Freeman
From Fixed Points to Chaos: Three Models of Delayed Discrimination
Barak, Omri; Sussillo, David; Romo, Ranulfo; Tsodyks, Misha; Abbott, L.F.
2013-01-01
Working memory is a crucial component of most cognitive tasks. Its neuronal mechanisms are still unclear despite intensive experimental and theoretical explorations. Most theoretical models of working memory assume both time-invariant neural representations and precise connectivity schemes based on the tuning properties of network neurons. A different, more recent class of models assumes randomly connected neurons that have no tuning to any particular task, and bases task performance purely on adjustment of network readout. Intermediate between these schemes are networks that start out random but are trained by a learning scheme. Experimental studies of a delayed vibrotactile discrimination task indicate that some of the neurons in prefrontal cortex are persistently tuned to the frequency of a remembered stimulus, but the majority exhibit more complex relationships to the stimulus that vary considerably across time. We compare three models, ranging from a highly organized linear attractor model to a randomly connected network with chaotic activity, with data recorded during this task. The random network does a surprisingly good job of both performing the task and matching certain aspects of the data. The intermediate model, in which an initially random network is partially trained to perform the working memory task by tuning its recurrent and readout connections, provides a better description, although none of the models matches all features of the data. Our results suggest that prefrontal networks may begin in a random state relative to the task and initially rely on modified readout for task performance. With further training, however, more tuned neurons with less time-varying responses should emerge as the networks become more structured. PMID:23438479
Complex Networks Renormalization: Flows and Fixed Points Filippo Radicchi,1
Ramasco, José Javier
-scale transformation. Many complex systems such as the World Wide Web (WWW), the Internet, social and biological be performed. The concept of length can only be defined in the graph-theoretical sense of the number of links a network by means of a box-covering technique, in which a box includes nodes such that the distance between
Kurt Symanzik - a stable fixed point beyond triviality
F. Kleefeld
2005-08-04
In 1970 Kurt Symanzik proposed a "precarious" phi**4-theory with a negative quartic coupling constant as a valid candidate for an asymptotically free theory of strong interactions. Symanzik's deep insight in the non-trivial properties of this theory has been overruled since then by the Hermitian intuition of generations of scientists, who considered or consider this actually non-Hermitian highly important theory to be unstable. This short - certainly controversial - communication tries to shed some light on the historical and formalistic context of Symanzik's theory in order to sharpen our (quantum) intuition about non-perturbative theoretical physics between (non)triviality and asymptotic freedom.
Kurt Symanzik - a stable fixed point beyond triviality
Kleefeld, F
2005-01-01
In 1970 Kurt Symanzik proposed a precarious phi**4-theory with a negative quartic coupling constant as a valid candidate for an asymptotically free theory of strong interactions. Symanzik's deep insight in the non-trivial properties of this theory has been overruled since then by the Hermitian intuition of generations of scientists, who considered or consider this actually non-Hermitian highly important theory to be unstable. This short - certainly controversial - communication tries to shed some light on the historical and formalistic context of Symanzik's theory in order to sharpen our intuition and to allow a more decisive assessment to theoretical physics between (non)triviality and asymptotic freedom.
Fixed point free elements of prime order in permutation groups
Giudici, Michael
. . . . . . . . . . . . . . . . . . . . 38 3.4.1 T = PSp(2m; q) for m; q even and m 6= 2. . . . . . . . . . . . . 44 3.4.2 T = PSp(4; q) for q even. . . . . . . . . . . . . . . . . . . . . . 46 3.4.3 T = PSp(4; q) for q odd
Using a Card Trick to Illustrate Fixed Points and Stability
ERIC Educational Resources Information Center
Champanerkar, Jyoti; Jani, Mahendra
2015-01-01
Mathematical ideas from number theory, group theory, dynamical systems, and computer science have often been used to explain card tricks. Conversely, playing cards have been often used to illustrate the mathematical concepts of probability distributions and group theory. In this paper, we describe how the 21-card trick may be used to illustrate…
PERFORMANCE OF FIXED-POINT FFT'S: ROUNDING AND SCALING CONSIDERATIONS
Kabal, Peter
= S2N and for N odd. SN = S4N. Also 1 SN be shown that the magnitudes of the real and imaginary parts of the output of the complex DFT are bounded by NaSN. For N a multiple of 4. -- 4cos(r/N) 3N -- N sin(ir/N) For N even but not a multiple of 4. SN
LANDSLIDE DATA FIX BEFORE NON-GEOLOGISTS "FIX" THE LANDSLIDE
Nichols, Kyle K.
LANDSLIDE DATA FIX BEFORE NON- GEOLOGISTS "FIX" THE LANDSLIDE NICHOLS, Kyle K., Department, and WRIGHT, Stephen, Department of Geology, University of Vermont, Burlington, VT 05405 Landslides are an unpredictable but common Earth process. Since landslides do not occur on a knowable schedule, it is difficult
Rosenbaum, David A.; Chapman, Kate M.; Coelho, Chase J.; Gong, Lanyun; Studenka, Breanna E.
2013-01-01
Actions that are chosen have properties that distinguish them from actions that are not. Of the nearly infinite possible actions that can achieve any given task, many of the unchosen actions are irrelevant, incorrect, or inappropriate. Others are relevant, correct, or appropriate but are disfavored for other reasons. Our research focuses on the question of what distinguishes actions that are chosen from actions that are possible but are not. We review studies that use simple preference methods to identify factors that contribute to action choices, especially for object-manipulation tasks. We can determine which factors are especially important through simple behavioral experiments. PMID:23761769
POLICY ON FIXED-TERM EMPLOYMENT AND
Martin, Ralph R.
P1415-507 POLICY ON FIXED-TERM EMPLOYMENT AND Procedure for employing staff on Fixed-Term Contracts for employing staff on Fixed-Term Contracts and Fixed Term Funding Streams 1. Introduction This document supports the University's Policy on Fixed-Term Employment and Staff Employed on Fixed Term Funding Streams
NSDL National Science Digital Library
2012-10-30
In this online math game from Cyberchase, learners use measurement to help Ziff fix up his house. Learners use a ruler to make measurements and then cut new windows, doors, etc. to make fixes to the house. There are six rounds in this game.
Democratic Superstring Field Theory and Its Gauge Fixing
NASA Astrophysics Data System (ADS)
Kroyter, M.
This work is my contribution to the proceedings of the conference``SFT2010 -- the third international conference on string field theory and related topics'' and it reflects my talk there, which described the democratic string field theory and its gauge fixing. The democratic string field theory is the only fully RNS string field theory to date. It lives in the large Hilbert space and includes all picture numbers. Picture changing amounts in this formalism to a gauge transformation. We describe the theory and its properties and show that when partially gauge fixed it can be reduced to the modified theory and to the non-polynomial theory. In the latter case we can even include the Ramond sector in the picture-fixed action. We also show that another partial gauge-fixing leads to a new consistent string field theory at picture number -1.
Total effective dose equivalent associated with fixed uranium surface contamination
Bogard, J.S.; Hamm, R.N.; Ashley, J.C.; Turner, J.E.; England, C.A.; Swenson, D.E.; Brown, K.S.
1997-04-01
This report provides the technical basis for establishing a uranium fixed-contamination action level, a fixed uranium surface contamination level exceeding the total radioactivity values of Appendix D of Title 10, Code of Federal Regulations, part 835 (10CFR835), but below which the monitoring, posting, and control requirements for Radiological Areas are not required for the area of the contamination. An area of fixed uranium contamination between 1,000 dpm/100 cm{sup 2} and that level corresponding to an annual total effective dose equivalent (TEDE) of 100 mrem requires only routine monitoring, posting to alert personnel of the contamination, and administrative control. The more extensive requirements for monitoring, posting, and control designated by 10CFR835 for Radiological Areas do not have to be applied for these intermediate fixed-contamination levels.
Point de Contact National Action climatique,
Bordenave, Charles
and wellbeing 7 472 Food security, sustainable agriculture, marine and maritime and inland water research écosystèmes · Sustainable supply of non-energy and non-agricultural raw materials Assurer l and climate change resilient economy and society, the protection and sustainable management of natural
Liminality as Thought and Action
ERIC Educational Resources Information Center
Emmanuel, Donna T.
2011-01-01
Turner's (1974) conception of liminal space provides an entry point to look beyond the given and to create opportunities to examine, critique, and challenge the assumptions inherent in many music programs. Building upon his theory of liminality as a place that is "ambiguous, neither here or there, betwixt and between all fixed points of…
75 FR 70704 - Federal Copyright Protection of Sound Recordings Fixed Before February 15, 1972
Federal Register 2010, 2011, 2012, 2013, 2014
2010-11-18
...LIBRARY OF CONGRESS Copyright Office [Docket No. 2010-4] Federal Copyright Protection of Sound Recordings Fixed Before February 15, 1972 AGENCY: Copyright Office, Library of Congress. ACTION: Notice of inquiry;...
47 CFR 22.603 - 488-494 MHz fixed service in Hawaii.
Code of Federal Regulations, 2013 CFR
2013-10-01
...2013-10-01 2013-10-01 false 488-494 MHz fixed service in Hawaii. 22.603 Section 22.603 Telecommunication FEDERAL...Point-To-Point Operation § 22.603 488-494 MHz fixed service in Hawaii. Before filing applications for...
47 CFR 22.603 - 488-494 MHz fixed service in Hawaii.
Code of Federal Regulations, 2014 CFR
2014-10-01
...2014-10-01 2014-10-01 false 488-494 MHz fixed service in Hawaii. 22.603 Section 22.603 Telecommunication FEDERAL...Point-To-Point Operation § 22.603 488-494 MHz fixed service in Hawaii. Before filing applications for...
47 CFR 22.603 - 488-494 MHz fixed service in Hawaii.
Code of Federal Regulations, 2012 CFR
2012-10-01
...2012-10-01 2012-10-01 false 488-494 MHz fixed service in Hawaii. 22.603 Section 22.603 Telecommunication FEDERAL...Point-To-Point Operation § 22.603 488-494 MHz fixed service in Hawaii. Before filing applications for...
Neutron Electric Dipole Moment at Fixed Topology
Keh-Fei Liu
2009-07-03
We describe the finite volume effects of CP-odd quantities, such as the neutron electric dipole moment and the anapole moment in the $\\theta$-vacuum, under different topological sectors. We evaluate the three-point Green's functions for the electromagnetic current in a fixed non-trivial topological sector in order to extract these CP-odd observables. We discuss the role of zero modes in the CP-odd Green's function and show that, in the quenched approximation, there is a power divergence in the quark mass for CP-odd quantities at finite volume.
Why to treat subjects as fixed effects.
Adelman, James S; Estes, Zachary
2015-09-01
Adelman, Marquis, Sabatos-DeVito, and Estes (2013) collected word naming latencies from 4 participants who read 2,820 words 50 times each. Their recommendation and practice was that R² targets set for models should take into account subject idiosyncrasies as replicable patterns, equivalent to a subjects-as-fixed-effects assumption. In light of an interaction involving subjects, they broke down the interaction into individual subject data. Courrieu and Rey's (2015) commentary argues that (a) single-subject data need not be more reliable than subject-average data, and (b) anyway, treating groups of subjects as random samples leads to valid conclusions about general mechanisms of reading. Point (a) was not part of Adelman et al.'s claim. In this reply, we examine the consequences of using the fixed-effect assumption. It (a) produces the correct target to check if by-items regression models contain all necessary variables, (b) more accurately constrains cognitive models, (c) more accurately reveals general mechanisms, and (d) can offer more powerful tests of effects. Even when individual differences are not the primary focus of a study, the fixed-effect analysis is often preferable to the random-effects analysis. (PsycINFO Database Record PMID:26348203
Nonperturbative QCD, gauge-fixing, Gribov copies, and the lattice
Anthony G. Williams
2003-04-07
Perturbative QCD uses the Faddeev-Popov gauge-fixing procedure, which leads to ghosts and the local BRST invariance of the gauge-fixed perturbative QCD action. In the asymptotic regime, where perturbative QCD is relevant, Gribov copies can be neglected. In the nonperturbative regime, one must adopt either a nonlocal Gribov-copy free gauge (e.g., Laplacian gauge) or attempt to maintain local BRST invariance at the expense of admitting Gribov copies. These issues are explored. In addition, we discuss the relationship between recent Dyson-Schwinger based model calculations of the infrared behavior of QCD Green's functions and the lattice calculation of these quantities.
IEEE TVCG, VOL. XX, NO. XX, XXX 2006 1 Nearest Point Query on 184,088,599 Points in E3
Franklin, W. Randolph
IEEE TVCG, VOL. XX, NO. XX, XXX 2006 1 Nearest Point Query on 184,088,599 Points in E3 to preprocess more than 108 fixed points in E3 and then perform nearest point queries against them. With fixed), per point, with a very small constant factor. The data structure is a uniform grid in E3 , typically
9 CFR 417.3 - Corrective actions.
Code of Federal Regulations, 2010 CFR
2010-01-01
...HAZARD ANALYSIS AND CRITICAL CONTROL POINT (HACCP) SYSTEMS § 417.3 Corrective actions. (a) The written HACCP plan shall identify the corrective action...a deviation from a critical limit. The HACCP plan shall describe the corrective...
9 CFR 417.3 - Corrective actions.
Code of Federal Regulations, 2011 CFR
2011-01-01
...HAZARD ANALYSIS AND CRITICAL CONTROL POINT (HACCP) SYSTEMS § 417.3 Corrective actions. (a) The written HACCP plan shall identify the corrective action...a deviation from a critical limit. The HACCP plan shall describe the corrective...
Sartori, Luisa; Betti, Sonia
2015-01-01
Complementary colors are color pairs which, when combined in the right proportions, produce white or black. Complementary actions refer here to forms of social interaction wherein individuals adapt their joint actions according to a common aim. Notably, complementary actions are incongruent actions. But being incongruent is not sufficient to be complementary (i.e., to complete the action of another person). Successful complementary interactions are founded on the abilities: (i) to simulate another person's movements, (ii) to predict another person's future action/s, (iii) to produce an appropriate incongruent response which differ, while interacting, with observed ones, and (iv) to complete the social interaction by integrating the predicted effects of one's own action with those of another person. This definition clearly alludes to the functional importance of complementary actions in the perception-action cycle and prompts us to scrutinize what is taking place behind the scenes. Preliminary data on this topic have been provided by recent cutting-edge studies utilizing different research methods. This mini-review aims to provide an up-to-date overview of the processes and the specific activations underlying complementary actions. PMID:25983717
Sartori, Luisa; Betti, Sonia
2015-01-01
Complementary colors are color pairs which, when combined in the right proportions, produce white or black. Complementary actions refer here to forms of social interaction wherein individuals adapt their joint actions according to a common aim. Notably, complementary actions are incongruent actions. But being incongruent is not sufficient to be complementary (i.e., to complete the action of another person). Successful complementary interactions are founded on the abilities: (i) to simulate another person’s movements, (ii) to predict another person’s future action/s, (iii) to produce an appropriate incongruent response which differ, while interacting, with observed ones, and (iv) to complete the social interaction by integrating the predicted effects of one’s own action with those of another person. This definition clearly alludes to the functional importance of complementary actions in the perception–action cycle and prompts us to scrutinize what is taking place behind the scenes. Preliminary data on this topic have been provided by recent cutting-edge studies utilizing different research methods. This mini-review aims to provide an up-to-date overview of the processes and the specific activations underlying complementary actions. PMID:25983717
Coohill, T P
1991-11-01
Action spectroscopy has a long history and is of central importance to photobiological studies. Action spectra were among the first assays to point to chlorophyll as the molecule most responsible for plant growth and to DNA as the genetic material. It is useful to construct action spectra early in the investigation of new areas of photobiological research in an attempt to determine the wavelength limits of the radiation region causing the studied response. But due to the severe absorption of ultraviolet (UV) radiation by biological samples, UV action spectra were first limited to small cells (bacteria and fungi). Advances in techniques (e.g. single cell culture) and analysis allowed accurate action spectra to be reported even for mammalian cells. But precise analytical action spectra are often difficult to obtain when large, pigmented, or groups of cells are investigated. Here some action spectra are limited in interpretation and merely supply a wavelength vs effect curve. When polychromatic sources are employed, the interpretation of action spectra is even more complex and formidable. But such polychromatic action spectra can be more directly related to ambient responses. Since precise action spectra usually require the completion of a relatively large number of careful experiments using somewhat sophisticated equipment over a range of at least six wavelengths, they are often not pursued. But they remain central to the elucidation of the effect being studied. The worldwide community has agreed that stratospheric ozone is depleting, with the possibility of a consequent rise in the amount of UV-B (290-320 nm) reaching the earth's surface. It is therefore essential that new action spectra be completed for UV-B effects on a large variety of responses of human, animal, and aquatic plant systems. Combining these action spectra with the known amounts of UV-B reaching the biosphere can give rise to solar UV effectiveness spectra that, in turn, can give rise to estimates of effect. Preliminary estimates suggest that ozone layer depletion may seriously impact such important biological end-points as skin cancer, cataracts, the immune system, crop yields, and oceanic phytoplankton. So action spectra continue to play a central role in important photobiological research. PMID:1798760
Correlation in a Gaussian chain with the ends fixed
NASA Astrophysics Data System (ADS)
Kawai, K.; Okumura, K.
2006-11-01
We consider an ideal chain whose ends are fixed without fluctuation at different points, possibly by optical tweezers. We derive a two-point probability distribution of a corresponding random walk and explicitly calculate the scattering function. We find that the contour plot of the resulting function shows a kind of normal butterfly pattern, contaminated by wavy texture. These results are compared with some representative previous models.
Kolar, Irena; Whitney, Gill
2015-01-01
This paper reports on an innovative approach to facilitating the expedient reporting of web accessibility issues using volunteers. The aim of the Fix the Web website and project is not to replace existing formal methods of reporting inaccessible websites, but to provide an easy, informal way by which users with disabilities can report inaccessible websites quickly and can be assured that a volunteer on their behalf will take the issue up with the website owner or administrator. Fix the Web was launched in 2010 and from a small start has gone onto success in dealing with nearly 150 inaccessible websites. The results of an analysis of reports of inaccessible websites received by the Fix the Web are also presented and the practical benefits and limitations of using an informal approach to achieve accessibility are discussed. PMID:26294463
NSDL National Science Digital Library
The iFixIt guides are extremely helpful to computer repair technicians who would like to be able to fix Apple brand computers as well as PCs. The guides included on the site are mainly dedicated to Apple laptops, including MacBooks, PowerBooks, and iBooks, but also include a few guides pertaining to the Mac Mini. There are numerous guides to choose from, all organized by computer type, computer specifications, and what the repairperson would like to accomplish. The guides are extremely easy to follow and contain detailed pictures and diagrams, which are very helpful. Most of the guides are also downloadable. The guides include lists of tools and links to purchase the tools if the user doesnï¿½t have them. All of the information on iFixIt is free and no login is required.
NASA Astrophysics Data System (ADS)
Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu
2014-06-01
We give an evidence of the Big Fix. The theory of wormholes and multiverse suggests that the parameters of the Standard Model are fixed in such a way that the total entropy at the late stage of the universe is maximized, which we call the maximum entropy principle. In this paper, we discuss how it can be confirmed by the experimental data, and we show that it is indeed true for the Higgs vacuum expectation value vh. We assume that the baryon number is produced by the sphaleron process, and that the current quark masses, the gauge couplings and the Higgs self-coupling are fixed when we vary vh. It turns out that the existence of the atomic nuclei plays a crucial role to maximize the entropy. This is reminiscent of the anthropic principle, however it is required by the fundamental law in our case.
Yuta Hamada; Hikaru Kawai; Kiyoharu Kawana
2014-09-09
We give an evidence of the Big Fix. The theory of wormholes and multiverse suggests that the parameters of the Standard Model are fixed in such a way that the total entropy at the late stage of the universe is maximized, which we call the maximum entropy principle. In this paper, we discuss how it can be confirmed by the experimental data, and we show that it is indeed true for the Higgs vacuum expectation value $v_{h}$. We assume that the baryon number is produced by the sphaleron process, and that the current quark masses, the gauge couplings and the Higgs self coupling are fixed when we vary $v_{h}$. It turns out that the existence of the atomic nuclei plays a crucial role to maximize the entropy. This is reminiscent of the anthropic principle, however it is required by the fundamental low in our case.
Mobile versus fixed site lithotripsy.
Lewis, C.; Burgess, N. A.; Feneley, R. C.; Matthews, P. N.
1991-01-01
The efficacy of a mobile Dornier HM4 lithotriptor, was compared with that of a fixed site Siemens Lithostar. A total of 115 calculi in 98 patients were treated, 55 on the mobile Dornier and 60 on the Lithostar. The groups were similar except for stone size, the mean of the Lithostar group being 11 mm compared with 7.7 mm in the Dornier group. Fragmentation rates were not significantly different, 88% and 75% on the mobile and fixed site machines, respectively and, at 3 months follow-up 66% and 46% were stone free or with fragments of less than 2 mm. There were no serious complications, and the incidence of mild complications was similar in the two groups. We conclude that the mobile Dornier HM4 is an effective lithotriptor and can offer several advantages over fixed site machines. PMID:1929134
Fixed Topology Skeletons Polina Golland and W. Eric. L. Grimson
Golland, Polina
Fixed Topology Skeletons Polina Golland and W. Eric. L. Grimson Artificial Intelligence Laboratory, we present a novel approach to robust skeleton extraction. We use undirected graphs to model connectivity of the skeleton points. The graph topology remains unchanged throughout the skeleton computation
Point configurations that are asymmetric yet balanced
Cohn, Henry
Abstract: A configuration of particles confined to a sphere is balanced if it is in equilibrium under all force laws (that act between pairs of points with strength given by a fixed function of distance). It is straightforward ...
ERIC Educational Resources Information Center
Vermont State Dept. of Education, Montpelier.
The Vermont Department of Education's Affirmative Action Program is outlined. In addition to listing laws and regulations relating to employment discrimination, affirmative action goals and activities are identified for personnel recruitment, advancement, and training and education. The program covers regular employees, exempt employees, temporary…
Fixed Costs and Hours Constraints
ERIC Educational Resources Information Center
Johnson, William R.
2011-01-01
Hours constraints are typically identified by worker responses to questions asking whether they would prefer a job with more hours and more pay or fewer hours and less pay. Because jobs with different hours but the same rate of pay may be infeasible when there are fixed costs of employment or mandatory overtime premia, the constraint in those…
Wronskians, cyclic group actions, and ribbon tableaux
Kevin Purbhoo
2011-01-01
The Wronski map is a finite, PGL_2(C)-equivariant morphism from the Grassmannian Gr(d,n) to a projective space (the projectivization of a vector space of polynomials). We consider the following problem. If C_r < PGL_2(C) is a cyclic subgroup of order r, how may C_r-fixed points are in the in a fibre of the Wronski map over a C_r-fixed point in the
McConnell, Terry
SCHOLARSHIP IN ACTION SCHOLARSHIP IN ACTION SCHOLARSHIP IN ACTION SCHOLARSHIP IN ACTION SCHOLARSHIP IN ACTION SCHOLARSHIP IN ACTION #12;Every day, Syracuse University is propelled by the bold idea of Scholarship in Action. Education that is not static or for its own sake, but the living expression of insights
A Partially Gauged Fixed Hamiltonian for Scalar Field Collapse
R. G. Daghigh; J. Gegenberg; G. Kunstatter
2007-08-09
We derive a partially gauge fixed Hamiltonian for black hole formation via real scalar field collapse. The class of models considered includes many theories of physical interest, including spherically symmetric black holes in $D$ spacetime dimensions. The boundary and gauge fixing conditions are chosen to be consistent with generalized Painleve-Gullstrand coordinates, in which the metric is regular across the black hole future horizon. The resulting Hamiltonian is remarkably simple and we argue that it provides a good starting point for studying the quantum dynamics of black hole formation.
Expert anticipation from deceptive action.
Mori, Shuji; Shimada, Takuro
2013-05-01
Expertise in sports enhances the ability to anticipate forthcoming events from the observation of a player's actions. In the present study, we investigated whether this ability is applicable to deceptive action. In three experiments, performance at anticipating the direction change of a running opponent was examined with experienced rugby players and novice counterparts. These experiments were conducted with reaction-time and temporal-occlusion tasks, in combination with eye movement recordings and the presentation of filmed actions and their point-light representations. The main finding was that the experienced players were superior to the novices in their anticipation of deceptive actions, although their performance was still impaired by the deception, in comparison with their anticipation of nondeceptive actions. We also found that the experienced players anticipated nondeceptive actions less accurately than the novices, suggesting that the players' expectations of deceptive actions worked negatively on their judgments of nondeceptive actions. The results obtained with the point-light representations closely resembled those obtained with the filmed sequences, indicating that anticipation was based on the kinematics of the running action. These results are discussed in the context of recent developments in research on expertise and deception in sports. PMID:23436250
Variable delivery, fixed displacement pump
Sommars, Mark F. (Sparland, IL)
2001-01-01
A variable delivery, fixed displacement pump comprises a plurality of pistons reciprocated within corresponding cylinders in a cylinder block. The pistons are reciprocated by rotation of a fixed angle swash plate connected to the pistons. The pistons and cylinders cooperate to define a plurality of fluid compression chambers each have a delivery outlet. A vent port is provided from each fluid compression chamber to vent fluid therefrom during at least a portion of the reciprocal stroke of the piston. Each piston and cylinder combination cooperates to close the associated vent port during another portion of the reciprocal stroke so that fluid is then pumped through the associated delivery outlet. The delivery rate of the pump is varied by adjusting the axial position of the swash plate relative to the cylinder block, which varies the duration of the piston stroke during which the vent port is closed.
NSDL National Science Digital Library
2013-06-21
In the first part of this video, we derive the law of mass action from one example of a picture of molecular collisions. For this course, we use the "law of mass action" to refer to an idea that chemical reaction kinetic rates can be expressed using products of the abundances of reactants raised to exponents. Studying cooperativity and Hill functions in the second part of the video allows us to investigate a simple example of bistability in the third video segment.
Comparison of slurry versus fixed-bed reactor costs for indirect liquefaction applications
Prakash, A.; Bendale, P.G.
1991-12-01
This work is a comparative evaluation of slurry reactors and fixed-bed reactors, with special emphasis on cost. Relative differences between slurry reactors and fixed-bed reactors have been pointed out in previous reviews; the differences pertinent to indirect liquefaction are summarized here. Design of both types is outlined.
Final consolidated action plan to Tiger Team
Not Available
1992-10-01
This document contains the planned actions to correct the deficiences identified in the Tiger Team Assessments of Sandia California (August 1990) and Sandia New Mexico (May 1991). Information is also included on the management structures, estimated costs, root causes, prioritization and schedules for the Action Plan. This Plan is an integration of the two individual Action Plans to provide a cost effective, integrated program for implementation by Sandia and monitoring by DOE. This volume (I) contains the findings and actions concerning the environment. Tables 4.2 and 4.7 summarize the annual costs estimated for completing the actions. The total costs for completion of all the actions are estimated to be $283 million over a 12 year period; the majority of the actions to be completed and costs incurred in the first five years. Resources are provided from DOE-ER/WM, the DOE/DP landlord funds (one time, physical fixes), and from the Sandia Indirect Budget.
Action perception predicts action performance
Bailey, Heather R.; Kurby, Christopher A.; Giovannetti, Tania; Zacks, Jeffrey M.
2013-01-01
Everyday action impairments often are observed in demented older adults, and they are common potential barriers to functional independence. We evaluated whether the ability to segment and efficiently encode activities is related to the ability to execute activities. Further, we evaluated whether brain regions important for segmentation also were important for action performance. Cognitively healthy older adults and those with very mild or mild dementia of the Alzheimer's type watched and segmented movies of everyday activities and then completed the Naturalistic Action Test. Structural MRI was used to measure volume in the dorsolateral prefrontal cortex (DLPFC), medial temporal lobes (MTL), posterior cortex, and anterior cingulate cortex (ACC). Dementia status and the ability to segment everyday activities strongly predicted naturalistic action performance, and MTL volume largely accounted for this relationship. In addition, the current results supported the Omission-Commission Model: Different cognitive and neurological mechanisms predicted different types of action error. Segmentation, dementia severity, and MTL volume predicted everyday omission errors, DLPFC volume predicted commission errors, and ACC volume predicted action additions. These findings suggest that event segmentation may be critical for effective action production, and that the segmentation and production of activities may recruit the same event representation system. PMID:23851113
Coherent Social Action Michael Wooldridge 1
Woolridge, Mike
possibility. This paper proposes that a deep theory of social action should account for the whole spectrum unifies different types of social action, and is therefore a possible starting point for a deep theory that team action theories cannot ac count for. There are several reasons for this. First, `mutual' mental
Coherent Social Action Michael Wooldridge1
Woolridge, Mike
possibility. This paper proposes that a deep theory of social action should account for the whole spectrum unifies different types of social action, and is therefore a possible starting point for a deep theory that team action theories cannot ac- count for. There are several reasons for this. First, `mutual' mental
SFT Action for Separated D-branes
Longton, Matheson
2012-01-01
We present an action for Cubic String Field Theory with one embedding coordinate treated separately. We truncate the action at level (3,9), but unlike many other works we do not impose twist symmetry. We also allow arbitrary zero-modes for the direction considered special. Our action provides a starting point for the study of numerous configurations of D-branes.
SFT Action for Separated D-branes
Matheson Longton
2012-03-20
We present an action for Cubic String Field Theory with one embedding coordinate treated separately. We truncate the action at level (3,9), but unlike many other works we do not impose twist symmetry. We also allow arbitrary zero-modes for the direction considered special. Our action provides a starting point for the study of numerous configurations of D-branes.
Non-Strebel points and variability sets
Yi Qi; Shengjian Wu
2003-01-01
This paper studies the subset of the non-Strebel points in the universal Teichmüller spaceT. Let z0 ? ? be a fixed point. Then we prove that for every non-Strebel pointh, there is a holomorphic curve ?: [0, 1] ?T withh as its initial point satisfying the following conditions. (1) The curve ? is on a sphere centered at the base-point
Vibrational characteristics of a long and very flexible rotating fixed-free beam
Zarco Cruz, Juan Carlos
2003-01-01
The differential eigenvalue problem of a long and very flexible rotating fixed-free beam is studied. This kind of system produces a singular perturbation equation with a turning point. The perturbation factor arises because of the division...
Analysis of fixed target collisions with the STAR detector
NASA Astrophysics Data System (ADS)
Haag, Brooke
2012-11-01
Collisions between beam halo nuclei and the aluminum beam pipe allow the STAR detector at RHIC to study fixed-target Au+Al collisions. The injection and sub-injection energy gold beams produce Au+Al collisions at center-of-mass energies of 4.5, 3.5, and 3.0 GeV. These collisions allow STAR to extend the beam energy scan to lower center of mass energies and higher baryon chemical potentials than previously possible. This in turn provides a means of searching for the possible critical point to quantify the nature of the phase transition between hadronic and partonic matter. In this talk, fixed target acceptances for tracking will be discussed. Pion ratios extracted from these fixed-target collisions will be presented and compared to earlier published results from the AGS, SPS, and RHIC.
Analysis of fixed target collisions with the STAR detector
NASA Astrophysics Data System (ADS)
Haag, Brooke
2013-04-01
Collisions between beam halo nuclei and the aluminum beam pipe allow the STAR detector at RHIC to study fixed-target Au+Al collisions. The injection and sub-injection energy gold beams produce Au+Al collisions at center-of-mass energies of 4.5, 3.5, and 3.0 GeV. These collisions allow STAR to extend the beam energy scan to lower center of mass energies and higher baryon chemical potentials than previously possible. This in turn provides a means of searching for the possible critical point to quantify the nature of the phase transition between hadronic and partonic matter. In this talk, fixed target acceptances for tracking will be discussed. Pion ratios extracted from these fixed-target collisions will be presented and compared to earlier published results from the AGS, SPS, and RHIC.
NEARPT3 --Nearest Point Query in E3 with a Uniform
Franklin, W. Randolph
NEARPT3 -- Nearest Point Query in E3 with a Uniform Grid W. Randolph Franklin Rensselaer fixed points, p, drawn from some distribution, D, in E3 . Preprocess them. Select query points, q. Superimpose a uniform grid in E3 on the data. 2. Insert the fixed points. 3. Locate the queries and spiral out
"No quick fixes" for environment, population balance.
1992-01-01
The 90s is a critical decade if population stabilization is to occur in a manner that is both peaceful to people and the planet. Sustainable development, population stabilization, and environmental health are not separate issues. They must all be strived for simultaneously. None will be possible without the other 2. For example, conservation measures alone will not alleviate environmental degradation. These are the basic ideas in a speech given by Werner Fornos, president of the Population Institute, to an audience of 150 including ambassadors, delegates to the UN, and UN officials. There are no quick fixes to these problems. Waiting to take action only compounds the problem. The longer we wait to address these issues, the longer, and more expensive, it is to correct them. The relationship between population growth and environmental and ecological deterioration is not always evident. That fact should in no way prevent all concerned parties from acting promptly. Population policy intervention is the least expensive method of dealing with global environmental problems. The less people there are, the less pressure there is on the Earth's resources. Fornos received a special award from Theodore W. Kheel, chair of the Earth Summit Committee. The award is a Robert Rauschenberg print, inspired by a quote from William S. Burroughs: "They did not fully understand the technique. In a short time they nearly wrecked the planet." PMID:12343552
Global Positioning System Antenna Fixed Height Tripod Adapter
NASA Technical Reports Server (NTRS)
Dinardo, Steven J.; Smith, Mark A.
1997-01-01
An improved Global Positioning em antenna adaptor allows fixed antenna height measurements by removably attaching an adaptor plate to a conventional surveyor's tripod. Antenna height is controlled by an antenna boom which is a fixed length rod. The antenna is attached to one end of the boom. The opposite end of the boom tapers to a point sized to fit into a depression at the center of survey markers. The boom passes through the hollow center of a universal ball joint which is mounted at the center of the adaptor plate so that the point of the rod can be fixed in the marker's central depression. The mountains of the ball joint allow the joint to be moved horizontally in any direction relative to the tripod. When the ball joint is moved horizontally, the angle between the boom and the vertical changes because the boom's position is fixed at its lower end. A spirit level attached to the rod allows an operator to determine when the boom is plumb. The position of the ball joint is adjusted horizontally until the boom is plumb. At that time the antenna is positioned exactly over the center of the monument and the elevation of the antenna is precisely set by the length of the boom.
Fix, Jim
to constant factors and quantify performance for even moderate data sizes. Our caching model is realistic: wec Copyright 2002 James D. Fix #12;#12;Cache Performance Analysis of Algorithms James D. Fix of Washington Abstract Cache Performance Analysis of Algorithms by James D. Fix Chair of Supervisory Committee
Fixed Income Division Nomura International plc
Macrina, Andrea
Fixed Income Division © Nomura International plc Symmetry methods for quadratic Gaussian models International plc Outline Motivation The quadratic Gaussian distribution The quadratic Gaussian process The quadratic Gaussian model #12;Fixed Income Division 3© Nomura International plc Part 1 Motivation #12;Fixed
Theta vacuum physics from QCD at fixed topology
Sinya Aoki; Hidenori Fukaya; Shoji Hashimoto; Tetsuya Onogi
2007-10-24
We propose a method to obtain physical quantities in the theta vacuum from those at fixed topology, which are different by finite size effects. Extending the work by Brower et al., we derive the formula to estimate these finite size corrections for arbitrary correlators in terms of the topological susceptibility and the theta dependence. Applying this formula, we show that topological susceptibility can be measured through two-point functions of pseudoscalar operator.
Stochastic gauge fixing for N = 1 supersymmetric Yang-Mills theory
Naohito Nakazawa
2006-10-31
The gauge fixing procedure for N=1 supersymmetric Yang-Mills theory (SYM) is proposed in the context of the stochastic quantization method (SQM). The stochastic gauge fixing, which was formulated by Zwanziger for Yang-Mills theory, is extended to SYM_4 in the superfield formalism by introducing a chiral and an anti-chiral superfield as the gauge fixing functions. It is shown that SQM with the stochastic gauge fixing reproduces the probability distribution of SYM_4, defined by the Faddeev-Popov prescription, in the equilibrium limit with an appropriate choice of the stochastic gauge fixing functions. We also show that the BRST symmetry of the corresponding stochastic action and the power counting argument in the superfield formalism ensure the renormalizability of SYM_4 in this context.
A New Look at Trigger Point Injections
Wong, Clara S. M.; Wong, Steven H. S.
2012-01-01
Trigger point injections are commonly practised pain interventional techniques. However, there is still lack of objective diagnostic criteria for trigger points. The mechanisms of action of trigger point injection remain obscure and its efficacy remains heterogeneous. The advent of ultrasound technology in the noninvasive real-time imaging of soft tissues sheds new light on visualization of trigger points, explaining the effect of trigger point injection by blockade of peripheral nerves, and minimizing the complications of blind injection. PMID:21969825
QCD, Gauge Fixing, and the Gribov Problem
A. G. Williams
2002-02-07
The standard techniques of gauge-fixing, such as covariant gauge fixing, are entirely adequate for the purposes of studies of perturbative QCD. However, they fail in the nonperturbative regime due to the presence of Gribov copies. These copies arise because standard local gauge fixing methods do not completely fix the gauge. Known Gribov-copy-free gauges, such as Laplacian gauge, are manifestly non-local. These issues are examined and the implications of non-local gauge-fixing for ghost fields, BRST invariance, and the proof of renormalizability of QCD are considered.
Simple Fixed Functional Space Maintainer
Sarawgi, Aditi; Marwah, Nikhil; Gumber, Parvind; Dutta, Samir
2014-01-01
ABSTRACT% Premature loss of a primary tooth is one of the most common etiology for malocclusion. Space maintainers are employed to prevent this complication. In anterior region, esthetics is an important concern along with function and space management. Fiber-reinforced composite (FRC) retained space maintainer solves all these purposes ef ficiently and ef fectively. In addition, the technique is simple and the appliance is very comfortable inside the oral cavity. Here is a case of premature loss of anterior primary tooth which was replaced by FRC retained esthetic functional space maintainer. The appliance was found to be functioning satisfactorily inside the oral cavity till the last visit (1 Year). How to cite this article: Goenka P, Sarawgi A, Marwah N, Gumber P, Dutta S. Simple Fixed Functional Space Maintainer. Int J Clin Pediatr Dent 2014;7(3):225-228. PMID:25709309
Canonical formulation of Pais-Ulhenbeck action and resolving the issue of branched Hamiltonian
Kaushik Sarkar; Nayem Sk; Ranajit Mandal; Abhik Kumar Sanyal
2015-09-21
Shortcomings of Dirac's constrained analysis in the context of fourth order Pais-Uhlenbeck oscillator action and the appearance of badly affected phase-space Hamiltonian for a generalized fourth order oscillator action, following Ostrogradski, Dirac and Horowitz's formalism, require a viable canonical formulation. This is achieved only after fixing appropriate variables at the end points and taking care of the counter surface terms obtained from variational principle. In the process a one-to-one correspondence between different higher order theories has been established. On the other hand the issue of branched Hamiltonian appearing in the presence of velocities with degree higher than two in the Lagrangian, has not been resolved uniquely as yet. However, often such terms appear with higher order theory, gravity in particular. Here we show that canonical formulation of higher order theory takes care of the issue elegantly.
NSDL National Science Digital Library
Founded over 40 years ago by an economist, Practical Action's aim is to help impoverished people "use technology to challenge poverty", to gain "access to technical options and knowledge", and "influence the social, economic and institutional systems for innovation and use of technology." The "Downloads" tab has a link to "Practical Answers" that cover almost two dozen themes and lets users browse the extensive library, submit technical questions to expert, and it also provides users with a section entitled "Share" which documents peoples' experience with Practical Action. Visitors will also find the "Featured Articles" section of the Downloads useful and full of such practical information as "Build Your Own Tippy Tap", for hand washing after toileting and a "Solar Voltaic System Design Info Sheet" that covers electrical design issues. Back on the homepage, visitors will find links to their social networking, e-newsletter, and the latest from their series of blogs.
NASA Technical Reports Server (NTRS)
1975-01-01
The role played by individual citizens as consumers of energy was examined, with emphasis on studying ways in which their action could result in energy conservation. It was shown that there are ways that energy can be conserved in this way, with citizens acting either individually or in groups. The potential savings are significant, but the actual savings may be quite small. The citizens need to be motivated to save and to believe in a conservation ethic; developing such an ethic is difficult, and perhaps not responsive to the shotgun approach now being attempted. The true course of action may be to synthesize new societal structures that provide the maximum evolution of culture within the limitation of scarce energy resources.
The gravitational Hamiltonian, first order action, Poincar\\'e charges and surface terms
Corichi, Alejandro
2015-01-01
We consider the issue of attaining a consistent Hamiltonian formulation, after a 3+1 splitting, of a well-defined action principle for asymptotically flat gravity. More precisely, our starting point is the gravitational first order Holst action with surface terms and fall-off conditions that make the variational principle and the covariant phase space formulation well-defined for asymptotically flat spacetimes. Keeping all surface terms and paying due attention to subtleties that arise from the different cut-offs at infinity, we give a derivation of the gravitational Hamiltonian starting from this action. The 3+1 decomposition and time gauge fixing results in a well-defined Hamiltonian action and a well-defined Hamiltonian formulation for the standard -and more general- asymptotic ADM conditions. Unlike the case of the Einstein-Hilbert action with Gibbons-Hawking-York or Hawking-Horowitz terms, here we {\\it {do}} recover the ADM energy-momentum from the covariant surface term also when more general variations...
Renormalization group scale-setting from the action—a road to modified gravity theories
NASA Astrophysics Data System (ADS)
Domazet, Silvije; Štefan?i?, Hrvoje
2012-12-01
The renormalization group (RG) corrected gravitational action in Einstein-Hilbert and other truncations is considered. The running scale of the RG is treated as a scalar field at the level of the action and determined in a scale-setting procedure recently introduced by Koch and Ramirez for the Einstein-Hilbert truncation. The scale-setting procedure is elaborated for other truncations of the gravitational action and applied to several phenomenologically interesting cases. It is shown how the logarithmic dependence of the Newton's coupling on the RG scale leads to exponentially suppressed effective cosmological constant and how the scale-setting in particular RG-corrected gravitational theories yields the effective f(R) modified gravity theories with negative powers of the Ricci scalar R. The scale-setting at the level of the action at the non-Gaussian fixed point in Einstein-Hilbert and more general truncations is shown to lead to universal effective action quadratic in the Ricci tensor.
Action Learning: Avoiding Conflict or Enabling Action
ERIC Educational Resources Information Center
Corley, Aileen; Thorne, Ann
2006-01-01
Action learning is based on the premise that action and learning are inextricably entwined and it is this potential, to enable action, which has contributed to the growth of action learning within education and management development programmes. However has this growth in action learning lead to an evolution or a dilution of Revan's classical…
ALL ACTIONS Number Priority Action Type
1 ALL ACTIONS Strategy Page Number Priority Action Type Sub-Action Number General Measures with Bonneville and the other action agencies to ensure that past fish-and- wildlife-related investments are kept-Action Number General Measures Responsible Entity New or Ongoing? Timeframe Forum Implement Adaptive Management
NASA Astrophysics Data System (ADS)
Zvizdic, Davor; Veliki, Tomislav; Grgec Bermanec, Lovorka
2008-06-01
This article describes the realization of the International Temperature Scale in the range from 234.3 K (mercury triple point) to 1084.62°C (copper freezing point) at the Laboratory for Process Measurement (LPM), Faculty of Mechanical Engineering and Naval Architecture (FSB), University of Zagreb. The system for the realization of the ITS-90 consists of the sealed fixed-point cells (mercury triple point, water triple point and gallium melting point) and the apparatus designed for the optimal realization of open fixed-point cells which include the gallium melting point, tin freezing point, zinc freezing point, aluminum freezing point, and copper freezing point. The maintenance of the open fixed-point cells is described, including the system for filling the cells with pure argon and for maintaining the pressure during the realization.
NASA Astrophysics Data System (ADS)
Frank, T. D.
A Lotka-Volterra model for an arbitrary number of competitors is studied for different ratios of self-inhibition versus cross-inhibition. It is shown that winner-takes-all fixed points (states of single surviving species) are the only stable fixed points of the model when cross-inhibition exceeds self-inhibition. Secondary bifurcations in terms of bifurcations between winner-takes-all fixed points induced by changes in the exponential growth rates of competitors are studied and the critical control parameters are identified. A selection principle is derived that states that evolution proceeds in such a way that exponential growth rates of surviving competitors are magnified in evolutionary bifurcation steps. The interacting competitor model is applied as an amplitude equation model for interacting patterns of self-organizing pattern formation systems with an eye on action selection and compulsive behaviors in humans. The possibility is discussed that human behavior is subjected to the selection principle of "faster growth rates".
The influence of fixed orthodontic appliances on halitosis.
Zurfluh, Monika A; van Waes, Hubertus J M; Filippi, Andreas
2013-01-01
Halitosis is a widely spread condition. There are numerous causes. The aim of this study was to investigate the influence of fixed orthodontic appliances on the occurrence of halitosis. 55 patients in an orthodontic practice were monitored at three points in time after application of orthodontic appliance (T1: immediately after application, T2: 4 weeks after application, T3: 3 months after application). Monitoring included patient self-evaluation, plaque index, tongue coating index and organoleptic measurement. The subjective parameters taste, dry mouth and breath odor did not show statistical differences. However, with the presence of fixed orthodontic appliances, confidence when performing dental hygiene decreased statistically significantly (p = 0.003). Additionally, the tongue coating index showed a statistically significant difference between T1 and T2 (p = 0.012) as well as T1 and T3 (p ? 0.001). Analogous results were found for organoleptic measurement (T1 and T2 [p = 0.002]; T1 and T3 [p ? 0.001]) and plaque index (T1 and T2/ T3 [p ? 0.001]). Fixed orthodontic appliances lead to a statistically significant increase of the plaque and tongue coating indices. A statistically significant increase was also observed with organoleptic measurement scores. The suspected positive correlation between halitosis and fixed orthodontic appliances was confirmed. Halitosis can be an important indicator of oral health during orthodontic treatment and can serve as a motivating factor for adequate patient oral health care maintenance. PMID:24554561
Counting primitive points of bounded height
Widmer, Martin
2012-01-01
Let $k$ be a number field and $K$ a finite extension of $k$. We count points of bounded height in projective space over the field $K$ generating the extension $K/k$. As the height gets large we derive asymptotic estimates with a particularly good error term respecting the extension $K/k$. In a future paper we will use these results to get asymptotic estimates for the number of points of fixed degree over $k$. We also introduce the notion of an adelic Lipschitz height generalizing that of Masser and Vaaler. This will lead to further applications involving points of fixed degree on linear varieties and algebraic numbers of fixed degree satisfying certain subfield conditions.
Fixed drug eruptions with modafinil
Ghoshal, Loknath; Sinha, Mausumi
2015-01-01
Modafinil is a psychostimulant drug, which has been approved by the US Food and Drug Administration for the treatment of narcolepsy associated excessive daytime sleepiness, sleep disorder related to shift work, and obstructive sleep apnea syndrome. However, presently it is being used as a lifestyle medicine; in India, it has been misused as an “over the counter” drug. Modafinil is known to have several cutaneous side effects. Fixed drug eruption (FDE) is a distinctive drug induced reaction pattern characterized by recurrence of eruption at the same site of the skin or mucous membrane with repeated systemic administration. Only two case reports exist in the literature describing modafinil induced FDE until date. Here, we report two similar cases. The increasing use of this class of drug amongst the medical personnel might be posing a threat to the proper use and encouraging subsequent abuse. There might be a considerable population using these drugs unaware of the possible adverse effects. Authorities should be more alert regarding the sale and distribution of such medicines. PMID:25878389
Fixed position concentrating solar collector
Jakahi, D. Y.
1985-10-15
A fixed position concentrating solar collector in the form of a trough having an inner surface reflective to solar radiation and formed to direct the sun's rays entering the trough onto a radiation absorber element, the trough having end structures capable of selectively reflecting solar radiation into the trough or of being made transparent for passing solar radiation into the trough which would otherwise be blocked off by the trough end. Devices responsive to the position of the sun relative to the trough automatically control clearness-reflectiveness of the trough ends. End structures include flexible sheets on a roller, movable ends, jointly movable slats, leaves which may be aligned or fanned out, inflatable bags and flexible sheets controlled by bourdon tubes. A highly efficient configuration of the trough reflecting surface has a transverse plane profile defined by a compound parabolic curve comprising a half parabola joined to the other half of the parabola by a quarter circle shifted 90/sup 0/ with respect to the first half, the distance between the focus of the parabola being equal to the radius of the quarter circle and the focus of both of the half parabolas and the circle being in the same position.
Chen, J.M.; Lim, B.S.; Al-Ghusain, I.A.; Hao, O.J.; Lin, C.F.; Davis, A.P.; Kim, M.H.; Huang, J.
1993-06-01
This paper includes reports on several biological fixed film systems in wastewater and hazardous waste treatment. Biological treatment of a refinery wastewater was studied in a rotating biological contactor (RBC) unit coupled with polyurethane foam (PUF) as a porous biomass support attached on both sides of the biodisks. The RBC-PUF bioreactor exhibited better performance than conventional RBCs for the removal of chemical oxygen demand (COD), NH{sub 3}-N, phenol, hydrocarbons, and suspended solids because of higher concentrations of active biomass. Successful performance of an anaerobic-aerobic treatment process using a combination of RCBs with activated sludge was achieved for treating a dye wastewater. Two high-rate trickling filters, cross-flow (CF) and vertical flow, were examined over a two year period for biological treatment of seafood processing wastewater. Results suggested superior performance of CF plastic media with substrate removal following a pseudo half-order kinetic reaction. Submerged structured packings in biofilm reactors were tested and characterized for a wide range of applications. Their efficiency was discussed in terms of contaminant removals and SS retention.
Kolekar, Sanved; Padmanabhan, T.
2010-07-15
The Einstein-Hilbert action and its natural generalizations to higher dimensions (like the Lanczos-Lovelock action) have certain peculiar features. All of them can be separated into a bulk and a surface term, with a specific (''holographic'') relationship between the two, so that either term can be used to extract information about the other. Further, the surface term leads to entropy of the horizons on shell. It has been argued in the past that these features are impossible to understand in the conventional approach but find a natural explanation if we consider gravity as an emergent phenomenon. We provide further support for this point of view in this paper. We describe an alternative decomposition of the Einstein-Hilbert action and the Lanczos-Lovelock action into a new pair of surface and bulk terms, such that the surface term becomes the Wald entropy on a horizon and the bulk term is the energy density (which is the Arnowitt-Deser-Misner Hamiltonian density for Einstein gravity). We show that this new pair also obeys a holographic relationship, and we give a thermodynamic interpretation of this relation in this context. Since the bulk and surface terms, in this decomposition, are related to the energy and entropy, the holographic condition can be thought of as analogous to inverting the expression for entropy given as a function of energy S=S(E,V) to obtain the energy E=E(S,V) in terms of the entropy in a normal thermodynamic system. Thus the holographic nature of the action allows us to relate the descriptions of the same system in terms of two different thermodynamic potentials. Some further possible generalizations and implications are discussed.
The gravitational Hamiltonian, first order action, Poincaré charges and surface terms
Alejandro Corichi; Juan D. Reyes
2015-05-06
We consider the issue of attaining a consistent Hamiltonian formulation, after a 3+1 splitting, of a well-defined action principle for asymptotically flat gravity. More precisely, our starting point is the gravitational first order Holst action with surface terms and fall-off conditions that make the variational principle and the covariant phase space formulation well-defined for asymptotically flat spacetimes. Keeping all surface terms and paying due attention to subtleties that arise from the different cut-offs at infinity, we give a derivation of the gravitational Hamiltonian starting from this action. The 3+1 decomposition and time gauge fixing results in a well-defined Hamiltonian action and a well-defined Hamiltonian formulation for the standard -and more general- asymptotic ADM conditions. Unlike the case of the Einstein-Hilbert action with Gibbons-Hawking-York or Hawking-Horowitz terms, here we {\\it {do}} recover the ADM energy-momentum from the covariant surface term also when more general variations respecting asymptotic flatness are allowed. Additionally, our strategy yields a derivation of the parity conditions for connection variables independent of the conditions given by Regge and Teitelboim for ADM variables. Finally, we exhibit the other Poincar\\'e generators in terms of real Ashtekar-Barbero variables. We complement previous constructions in self-dual variables by pointing out several subtleties and refining the argument showing that -on shell- they coincide with the ADM charges. Our results represent the first consistent treatment of the Hamiltonian formulation for the connection-tetrad gravitational degrees of freedom, starting from a well posed action, in the case of asymptotically flat boundary conditions.
The gravitational Hamiltonian, first order action, Poincaré charges and surface terms
NASA Astrophysics Data System (ADS)
Corichi, Alejandro; Reyes, Juan D.
2015-10-01
We consider the issue of attaining a consistent Hamiltonian formulation, after a 3+1 splitting, of a well-defined action principle for asymptotically flat gravity. More precisely, our starting point is the gravitational first order Holst action with surface terms and fall off conditions that make the variational principle and the covariant phase space formulation well-defined for asymptotically flat spacetimes. Keeping all surface terms and paying due attention to subtleties that arise from the different cut-offs at infinity, we give a derivation of the gravitational Hamiltonian starting from this action. The 3+1 decomposition and time gauge fixing results in a well-defined Hamiltonian action and a well-defined Hamiltonian formulation for the standard—and more general—asymptotic ADM conditions. Unlike the case of the Einstein–Hilbert action with Gibbons–Hawking–York or Hawking–Horowitz terms, here we do recover the ADM energy momentum from the covariant surface term also when more general variations respecting asymptotic flatness are allowed. Additionally, our strategy yields a derivation of the parity conditions for connection variables independent of the conditions given by Regge and Teitelboim for ADM variables. Finally, we exhibit the other Poincaré generators in terms of real Ashtekar–Barbero variables. We complement previous constructions in self-dual variables by pointing out several subtleties and refining the argument showing that—on shell—they coincide with the ADM charges. Our results represent the first consistent treatment of the Hamiltonian formulation for the connection-tetrad gravitational degrees of freedom, starting from a well posed action, in the case of asymptotically flat boundary conditions.
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Software Faults Fixing Effort: Analysis and Prediction
NASA Technical Reports Server (NTRS)
Hamill, Maggie; Goseva-Popstojanova, Katerina
2014-01-01
Software developers spend significant amount of their time fixing faults. However, not many papers have addressed the effort needed to fix software faults. This paper is focused on comprehensive analysis of the fix implementation effort and factors that affect it, as well as on predicting the level of effort based on information recorded in software change requests. The work is based on data related to 1200 failures, extracted from the change tracking system of a large NASA mission. Our results show that (1) 83% of the total fix implementation effort was associated with only 20% of failures. (2) Both safety critical failures and post-release failures required three times more effort to fix compared to non-critical and pre-release counterparts, respectively. (3) Failures with fixes spread across multiple components and/or across multiple types of software artifacts required more effort. The spread across artifacts was more costly than spread across components. (4) Surprisingly, some types of faults associated with later life-cycle did not require significant effort, especially if only one type of artifact was fixed. (5) The level of fix implementation effort was predicted with 73% accuracy. The medium level fix implementation effort was classified more successfully than both low and high levels.
A UNIFIED TREATMENT OF DIVIDEND PAYMENT PROBLEMS UNDER FIXED COST AND IMPLEMENTATION DELAYS
Egami, Masahiko
A UNIFIED TREATMENT OF DIVIDEND PAYMENT PROBLEMS UNDER FIXED COST AND IMPLEMENTATION DELAYS ERHAN strategies at which the management initiates actions, i.e., declaration and payment of dividends. Our payments are subject to regulatory delay. The payment of dividends is not automatic and payments can
Applicationsfor2014 5 points 4 points 3 points 2 points 1 point
New South Wales, University of
Footballers' Association (A or W League) Member of Australian Team open or underage (all sports) Member of Australian underage team for a particular sport #12;MUSIC Applicationsfor2014 5 points 4 points 3 points 2
Evolutionary quantum cosmology in a gauge-fixed picture
Babak Vakili
2011-05-04
We study the classical and quantum models of a flat Friedmann-Robertson-Walker (FRW) space-time, coupled to a perfect fluid, in the context of the consensus and a gauge-fixed Lagrangian frameworks. It is shown that, either in the usual or in the gauge-fixed actions, the evolution of the universe based on the classical cosmology represents a late time power law expansion, coming from a big-bang singularity in which the scale factor goes to zero for the standard matter, and tending towards a big-rip singularity in which the scale factor diverges for the phantom fluid. We then employ the familiar canonical quantization procedure in the given cosmological setting to find the cosmological wave functions in the corresponding minisuperspace. Using a gauge-fixed (reduced) Lagrangian, we show that, it may lead to a Schr\\"{o}dinger equation for the quantum-mechanical description of the model under consideration, the eigenfunctions of which can be used to construct the time dependent wave function of the universe. We use the resulting wave function in order to investigate the possibility of the avoidance of classical singularities due to quantum effects by means of the many-worlds and ontological interpretation of quantum cosmology.