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1

Fixed-Point Actions in 1-Loop Perturbation Theory

It has been pointed out in recent papers that the example considered earlier in the O(N) sigma-model to test whether fixed-point actions are 1-loop perfect actually checked classical perfection only. To clarify the issue we constructed the renormalized trajectory explicitly in 1-loop perturbation theory. We found that the fixed-point action is not exactly 1-loop perfect. The cut-off effects are, however, strongly reduced also on the 1-loop level relative to those of the standard and tree level improved Symanzik actions. Some points on off- and on-shell improvement, Symanzik's program and fixed-point actions are also discussed.

Peter Hasenfratz; Ferenc Niedermayer

1997-06-02

2

New fixed point action for SU(3) lattice gauge theory

We present a new fixed point action for SU(3) lattice gauge theory, which has --- compared to earlier published fixed point actions --- shorter interaction range and smaller violations of rotational symmetry in the static $q\\bar{q}$-potential even at shortest distances.

Marc Blatter; Ferenc Niedermayer

1996-05-14

3

The fixed point action of the Schwinger model

We compute the fixed point action for the Schwinger model through an expansion in the gauge field. The calculation allows a check of the locality of the action. We test its perfection by computing the 1-loop mass gap at finite spatial volume.

F. Farchioni; V. Laliena

1997-09-08

4

Fixed Point SU(3) Gauge Actions: Scaling Properties and Glueballs

We present a new parametrization of a SU(3) fixed point (FP) gauge action using smeared ("fat") gauge links. We report on the scaling behaviour of the FP action on coarse lattices by means of the static quark-antiquark potential, the hadronic scale $r_0$, the string tension $\\sigma$ and the critical temperature $T_c$ of the deconfining phase transition. In addition, we investigate the low lying glueball masses where we observe no scaling violations within the statistical errors.

Ferenc Niedermayer; Philipp Rufenacht; Urs Wenger

2000-11-07

5

Fixed Point Gauge Actions with Fat Links: Scaling and Glueballs

A new parametrization is introduced for the fixed point (FP) action in SU(3) gauge theory using fat links. We investigate its scaling properties by means of the static quark-antiquark potential and the dimensionless quantities $r_0 T_c, T_c/\\sqrt{\\sigma}$ and $r_0 \\sqrt{\\sigma}$, where $T_c$ is the critical temperature of the deconfining phase transition, $r_0$ is the hadronic scale and $\\sigma$ is the effective string tension. These quantities scale even on lattices as coarse as $a \\approx 0.3$ fm. We also measure the glueball spectrum and obtain $m_{0^{++}}=1627(83)$ MeV and $m_{2^{++}}=2354(95)$ MeV for the masses of the scalar and tensor glueballs, respectively.

Ferenc Niedermayer; Philipp Rufenacht; Urs Wenger

2000-07-06

6

Simulating full QCD with the fixed point action

Because of its complex structure the parametrized fixed point action can not be simulated with the available local updating algorithms. We constructed, coded, and tested an updating procedure with 2+1 light flavors, where the targeted s quark mass is at its physical value while the u and d quarks should produce pions lighter than 300 MeV. In the algorithm a partially global gauge update is followed by several accept/reject steps, where parts of the determinant are switched on gradually in the order of their costs. The trial configuration that is offered in the last, most expensive, stochastic accept/reject step differs from the original configuration by a Metropolis + over-relaxation gauge update over a subvolume of {approx}(1.3 fm){sup 4}. The acceptance rate in this accept/reject step is {approx}0.4. The code is optimized on different architectures and is running on lattices with L{sub s}{approx_equal}1.2 fm and 1.8 fm at a resolution of a{approx_equal}0.15 fm.

Hasenfratz, Anna; Hasenfratz, Peter; Niedermayer, Ferenc [Department of Physics, University of Colorado, Boulder, Colorado 80304-0390 (United States); Institute for Theoretical Physics, University of Bern, CH-3012, Bern (Switzerland); Institute for Theoretical Physics, University of Bern, CH-3012, Bern (Switzerland)

2005-12-01

7

Simulating Full QCD with the Fixed Point Action

Due to its complex structure the parametrized fixed point action can not be simulated with the available local updating algorithms. We constructed, coded, and tested an updating procedure with 2+1 light flavors, where the targeted s-quark mass is at its physical value while the u- and d-quarks should produce pions lighter than 300MeV. In the algorithm a partially global gauge update is followed by several accept/reject steps, where parts of the determinant are switched on gradually in the order of their expenses. The trial configuration that is offered in the last, most expensive, stochastic accept/reject step differs from the original configuration by a Metropolis + over-relaxation gauge update over a sub-volume of ~(1.3 fm)^4. The acceptance rate in this accept/reject step is ~0.4. The code is optimized on different architectures and is running on lattices with L=1.2fm and 1.8fm at a resolution of a=0.15fm.

Anna Hasenfratz; Peter Hasenfratz; Ferenc Niedermayer

2005-06-25

8

Fixed point actions in SU(3) gauge theory: surface tension and topology

This work is organized in two independent parts. In the first part are presented some results concerning the surface tension in SU(3) obtained with a parametrized fixed point action. In the second part, a new, approximately scale-invariant, parametrized fixed point action is proposed which is suitable to study the topology in SU(3).

F. Farchioni; A. Papa

1997-09-08

9

The fixed point action for the Schwinger model: a perturbative approach

We compute the fixed point action of a properly defined renormalization group transformation for the Schwinger model through an expansion in the gauge field. It is local, with couplings exponentially suppressed with the distance. We check its perfection by computing the 1-loop mass gap at finite spatial volume, finding only exponentially vanishing cut off effects, in contrast with the standard action, which is affected by large power-like cut off effects. We point out that the 1-loop mass gap calculation provides a check of the classical perfection of the fixed point action, and not of the 1-loop perfection, as could be naively expected.

F. Farchioni; V. Laliena

1997-09-15

10

New results on cut-off effects in spectroscopy with the fixed point action

Our study on the cut-off effects in quenched light hadron spectroscopy and pion scattering length with the fixed point action is extended by results obtained at a lattice spacing a=0.102 fm in a box of size L=1.8 fm. The cut-off effects are small, but clearly seen as the resolution is increased from a=0.153 fm to a=0.102 fm. In the quark mass region where the errors are small and under control, our results on the APE plot lie close to the extrapolated numbers of the CP-PACS Collaboration.

Peter Hasenfratz; K. Jimmy Juge; Ferenc Niedermayer

2004-11-24

11

Chiral properties of the fixed point action of the Schwinger model

NASA Astrophysics Data System (ADS)

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.

Farchioni, F.; Lang, C. B.; Wohlgenannt, M.

1998-08-01

12

2+1 flavor QCD with the fixed point action in the $?$-regime

We generated configurations with the approximate fixed-point Dirac operator $D_\\mathrm{FP}$ on a $12^4$ lattice with $a \\approx 0.13 $fm where the scale was set by $r_0$. The distributions of the low lying eigenvalues in different topological sectors were compared with those of the Random Matrix Theory which leads to a prediction of the chiral condensate.

Peter Hasenfratz; Dieter Hierl; Vidushi Maillart; Ferenc Niedermayer; Andreas Schafer; Christof Weiermann; Manuel Weingart

2007-10-02

13

First results in QCD with 2+1 light flavors using the fixed-point action

This is a progress report on 2+1 flavor simulation with the FP action on a lattice with spatial size L=1.2fm. Since m_{ud} is quite small in our simulation we are in the delta regime for the two light flavors where the low lying excitations are described by a quantum mechanical rotator. From here we extract the low energy constant F. We also measure the AWI mass and present results on numerical issues like low-mode averaging and autocorrelation times.

Anna Hasenfratz; Peter Hasenfratz; Dieter Hierl; Ferenc Niedermayer; Andreas Schäfer

2006-10-17

14

The purpose of this paper is to draw attention to existential fixed-point logic. Among other things, we show that: (1) If a structure A satisfies an existential fixed-point formula ?, then A has a finite subset F such that every structure B with A |F = B |F satisfies ?. (2) Using existential fixed-point logic instead of first-order logic removes

Andreas Blass; Yuri Gurevich

1987-01-01

15

Gravitational Fixed Points from Perturbation Theory

The fixed point structure of the renormalization flow in higher derivative gravity is investigated in terms of the background covariant effective action using an operator cutoff that keeps track of powerlike divergences. Spectral positivity of the gauge fixed Hessian can be satisfied upon expansion in the asymptotically free higher derivative coupling. At one-loop order in this coupling strictly positive fixed points are found for the dimensionless Newton constant g{sub N} and the cosmological constant lambda, which are determined solely by the coefficients of the powerlike divergences. The renormalization flow is asymptotically safe with respect to this fixed point and settles on a lambda(g{sub N}) trajectory after O(10) units of the renormalization mass scale to accuracy 10{sup -7}.

Niedermaier, Max R. [CNRS, Laboratoire de Mathematiques et Physique Theorique, 37000 Tours (France)

2009-09-04

16

Decomposition in Fixed Point Computation.

National Technical Information Service (NTIS)

One result of this paper is the most efficient complementary pivot algorithm to date for handling the optimization problem. The second major contribution is a general structure on fixed point problems which, when present, enables one to work in a lower di...

D. Solow

1977-01-01

17

NASA Astrophysics Data System (ADS)

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 (k = 2 ) of the emfs measured at the inflection points of the melting curves are in the order of a few \\upmu 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.

Edler, F.; Ederer, P.

2014-08-01

18

NASA Astrophysics Data System (ADS)

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.

Edler, F.; Ederer, P.

2014-07-01

19

CANONICAL CONJUGATIONS AT FIXED POINTS OTHER THAN THE DENJOYWOLFF POINT

CANONICAL CONJUGATIONS AT FIXED POINTS OTHER THAN THE DENJOYÂWOLFF POINT PIETRO POGGIÂCORRADINI. The author is partially supported by NSF Grant DMS 97Â06408. 1 #12; 2 PIETRO POGGIÂCORRADINI Theorem 1

Poggi-Corradini, Pietro

20

Sequential conditions for fixed and periodic points

SEOUL;ENTIA CONDITIONS FOR I)KD AND PERIODIC POINTS A Thesis by Burnis C. Peters, Jr. Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE ~Au ust (Month...) 1970 (Year) Major Subject Mathematics SEQUENTIAL CONDITIONS FOR FIXED AND PERIODIC POINTS A Thesis by Burnis C. Peters, Jr. Approved as to style and content by: (Chai n of Committee) (Head of Department) (Member) (Member) (Member) (Member...

Peters, Burnis Charles

2012-06-07

21

Approximately J ? -homomorphisms: A fixed point approach

The functional equation (?) is stable if any function g satisfying the equation (?)approximately is near to the true solution of (?). A functional equation is superstable if every solution satisfying the equation approximately is an exact solution of it. Using fixed point methods, we prove the stability and superstability of J?-homomorphisms between J?-algebras for the generalized Jensen-type functional equation

M. Eshaghi Gordji; A. Najati

2010-01-01

22

ASIC For Complex Fixed-Point Arithmetic

NASA Technical Reports Server (NTRS)

Application-specific integrated circuit (ASIC) performs 24-bit, fixed-point arithmetic operations on arrays of complex-valued input data. High-performance, wide-band arithmetic logic unit (ALU) designed for use in computing fast Fourier transforms (FFTs) and for performing ditigal filtering functions. Other applications include general computations involved in analysis of spectra and digital signal processing.

Petilli, Stephen G.; Grimm, Michael J.; Olson, Erlend M.

1995-01-01

23

Fixed points and closure operators: Programmological aspects

The present article continues the research of others into the declarative nature of specification languages that describe the properties of objects in the form of solutions of equations with the left-hand side solved for the unknown, i.e., equations of the form x = f(x), x {element_of} D, where D is the data universe and f is an operator on D. The main purpose of this study is to elucidate the essence of the iterative processes that can be used to find the solutions of this equation, i.e., the fixed points of the operator f. In the programmological context, the data universe should be viewed as a data type, i.e., the set of data should be endowed with an appropriate structure. Operating on the lowest level of abstraction, we regard the data universe as a partially ordered set (poset), and thus speak of the first approximation, the next approximation, and so on. The relevant programmological applications also impose certain restrictions on the operators. Specifically, we consider operators that preserve the initial relation on data. Indeed, if x{prime} is an approximation to x, then we naturally stipulate that f(x{prime}) be an approximation to f(x). Moreover, the operators in applications are always effective; and as we know, effectiveness implies monotonicity. Thus, we consider equations of the form x = f(x), x {element_of} D, where D is a poset and f a monotone operator on D. Contrary to other references, where we used direct methods traceable to the work of Tarski, the main instrument in this study are the so-called a-chains of the element a of a poset relative to an operator. This enables us, first, to describe the fixed points of a monotone operator on any poset and, second, to construct the closure operator on the set of fixed points of the initial monotone operator.

Bui, D.B.; Red`ko, V.N.

1995-09-01

24

Holographic non-Fermi-liquid fixed points.

Techniques arising from string theory can be used to study assemblies of strongly interacting fermions. Via this 'holographic duality', various strongly coupled many-body systems are solved using an auxiliary theory of gravity. Simple holographic realizations of finite density exhibit single-particle spectral functions with sharp Fermi surfaces, of a form distinct from those of the Landau theory. The self-energy is given by a correlation function in an infrared (IR) fixed-point theory that is represented by a two-dimensional anti de Sitter space (AdS(2)) region in the dual gravitational description. Here, we describe in detail the gravity calculation of this IR correlation function. PMID:21422019

Faulkner, Tom; Iqbal, Nabil; Liu, Hong; McGreevy, John; Vegh, David

2011-04-28

25

Partial Fixed-Point Logic on Infinite Structures

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

Stephan Kreutzer; RWTH Aachen

2002-01-01

26

Fixed-point C language for digital signal processing

Fixed-point C language is proposed for convenient and efficient programming of fixed-point digital signal processors. This language has a `fix' data type that can have an individual integer wordlength according to the range of a variable. It can add or subtract two data having different integer wordlengths by automatically inserting shift operations. The accuracy of the fixed-point multiply operation is

Wonyong Sung; Jiyang Kang

1995-01-01

27

Stress-strain state of plates with point fixing

io Fixing at points, which is technologically expedient and easily practicable, is widely used in modern engineering practice. Such methods include rivet joints and weld seams ob- tained by point welding. A continuous weld seam may be regarded approximately as a system of fixing points. Note that, in applied plate and shell theories based on model concepts, there are no

N. I. Karpov; O. A. Karpova

1989-01-01

28

Error propagation in fixed-point ellipsometric inversions

Direct fixed-point inversions have been commonly used in ellipsometry for rapid determination of the optical constants and thickness of transparent and absorbing films formed on substrates. We formulate here the statistical covariance matrices of these optical parameters sought from a fixed-wave multiple sample, and multiple and single angle of incidence ellipsometric data using different known fixed-point inversions. Maple software used

T. Easwarakhanthan; P. Pigeat

2003-01-01

29

An extension of Mizoguchi-Takahaashi's fixed point theorem

Our main theorem is an extension of the well-known Mizoguchi-Takahaashi's fixed point theorem [N. Mizogochi and W. Takahashi, Fixed point theorems for multi-valued mappings on complete metric space, {\\it J. Math. Anal. Appl.} 141 (1989) 177--188].

Gordji, M Eshaghi; Ramezani, M; Khodaei, H

2010-01-01

30

An extension of Mizoguchi-Takahaashi's fixed point theorem

Our main theorem is an extension of the well-known Mizoguchi-Takahaashi's fixed point theorem [N. Mizogochi and W. Takahashi, Fixed point theorems for multi-valued mappings on complete metric space, {\\\\it J. Math. Anal. Appl.} 141 (1989) 177--188].

M. Eshaghi Gordji; H. Baghani; M. Ramezani; H. Khodaei

2010-01-01

31

On Fixed-point theorems in Intuitionistic Fuzzy metric Space

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.

T. K. Samanta; Sumit Mohinta; Iqbal H. Jebril

2010-11-06

32

Oxides in metal fixed points of the ITS-90

NASA Astrophysics Data System (ADS)

In the range between 0 °C and 961 °C, the International Temperature Scale of 1990 (ITS-90) depends to a great extent on the freezing points of the pure metals gallium, indium, tin, zinc, aluminium and silver. An up-to-date realization of these fixed points is based on cells containing metals of ultra-high purity (6N or better) and should include a correction for the influence of relevant impurities. Still, chemical analyses of the fixed-point material can show large amounts of oxygen, which had to be neglected so far, because of the lack of detailed knowledge about it, presuming it could be removed from the cell by applying a vacuum (less than 1 Pa) for a few hours. In this paper we discuss an equilibrium of several forms of oxygen in a fixed-point cell, gaseous in the cell's atmosphere, dissolved in the fixed-point metal and as oxide in a separate (solid) phase. We will conclude that in many fixed points most of the oxygen is not dissolved in the metal, but bound in oxides of the fixed-point metal as well as oxides of some impurities. To demonstrate the impact that the precipitation of impurity oxides has on thermometry, two indium fixed-point cells were doped with magnesium and chromium, which leave the fixed-point temperature unchanged. Further evidence is drawn from earlier work. All these results support the presumed existence of (at least one) persistent separate oxide phase in the fixed points of indium, tin, zinc and aluminium, which renders them eutectic or peritectic points and is a more likely reason why the oxygen content of a cell does not influence the fixed-point temperature. To complement these studies, thermodynamic calculations show how to treat the equilibrium in the cell quantitatively. Using available chemical data, a list is provided that indicates for each fixed-point metal (including the other metal fixed points of the ITS-90: mercury, gold, copper) the impurities that probably build oxides. Due to the agreement of the calculated values with the presented experimental results, we suggest excluding those impurities from the correction of a fixed-point temperature (e.g. the SIE method), unless there is strong evidence of their dissolution.

Fahr, Martin; Rudtsch, Steffen

2009-10-01

33

A new compact fixed-point blackbody furnace

NASA Astrophysics Data System (ADS)

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.

Hiraka, K.; Yamada, Y.; Ishii, J.; Oikawa, H.; Shimizu, T.; Kadoya, S.; Kobayashi, T.

2013-09-01

34

Simplified RPE Algorithm and its Fixed-Point Implementation

In mobile communication it is necessary to remove acoustic echo. Most acoustic echo cancellation algorithms are sensitive to double-talk. Recursive prediction error (RPE) algorithm is one of the best solutions to such problem. However integrating the algorithm into headsets is a challenging task due to conversion from floating-point to fixed-point. To address this problem, the simplification approach and fixed-point implementation

Yuan Hongxing; Wu Shaoqun; Zha Changjun

2011-01-01

35

Coincidence and fixed points in symmetric spaces under strict contractions

NASA Astrophysics Data System (ADS)

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.

Imdad, M.; Ali, Javid; Khan, Ladlay

2006-08-01

36

A Discontinuity in the Distribution of Fixed Point Sums

A Discontinuity in the Distribution of Fixed Point Sums Edward A. Bender Department of Mathematics existence of other discontinuities in f(n, r) for permutations. We generalize our results to other families

Bender, Ed

37

Combining Deduction Modulo and Logics of Fixed-Point Definitions

Inductive and coinductive specifications are widely used in formalizing computational systems. Such specifications have a natural rendition in logics that support fixed-point definitions. Another useful formalization device is that of recursive specifications. These specifications are not directly complemented by fixed-point reasoning techniques and, correspondingly, do not have to satisfy strong monotonicity restrictions. We show how to incorporate a rewriting capability into logics of fixed-point definitions towards additionally supporting recursive specifications. In particular, we describe a natural deduction calculus that adds a form of "closed-world" equality - a key ingredient to supporting fixed-point definitions - to deduction modulo, a framework for extending a logic with a rewriting layer operating on formulas. We show that our calculus enjoys strong normalizability when the rewrite system satisfies general properties and we demonstrate its usefulness in specifying and reasoning about syntax-based ...

Baelde, David

2012-01-01

38

Symmetry-breaking bifurcations on multidimensional fixed point subspaces

Symmetry-breaking bifurcations associated with fixed point subspaces of dimension greater than one are considered, for maximal isotropy subgroups, using techniques of blowing-up and degree theory. The leading non-linear term in the Taylor expansion of the bifurcation mapping restricted to the fixed point subspace, when satisfying a certain traversality condition or the non-vanishing of an appropriate index, governs the branching. Numerous

Ali Lari-Lavassani; William F. Langford; Koncay Huseyin

1994-01-01

39

Hopfsaddlenode bifurcation for fixed points of 3Ddi#eomorphisms

map G is constructed, such that at the central bifurcation the derivative has two complex conjugateHopfÂsaddleÂnode bifurcation for fixed points of 3DÂdi#eomorphisms: analysis of a resonance `bubbleÂsaddleÂnode bifurcation of fixed points of di#eoÂ morphisms is analysed by means of a case study: a twoÂparameter model

Barcelona, Universitat de

40

Fixed point property for general topologies in some Banach spaces

We study the fixed point property with respect to general vector topologies in L-embedded Banach spaces. Considering a class of topologies in l1 such that the standard basis is convergent, we characterize those of them for which the fixed point property holds. We show that in c0-sums of some Banach spaces the weak topology is in a sense the coarsest

MARIA A. JAP; ON PINEDA

2004-01-01

41

Existence and Properties of p-tupling Fixed Points

NASA Astrophysics Data System (ADS)

We prove the existence of fixed points of p-tupling renormalization operators for interval and circle mappings having a critical point of arbitrary real degree r > 1. Some properties of the resulting maps are studied: analyticity, univalence, behavior as r tends to infinity.

Epstein, Henri

42

Entanglement entropy at infinite randomness fixed points in higher dimensions

The entanglement entropy of the two-dimensional random transverse Ising model is studied with a numerical implementation of the strong disorder renormalization group. The asymptotic behavior of the entropy per surface area diverges at, and only at, the quantum phase transition that is governed by an infinite randomness fixed point. Here we identify a double-logarithmic multiplicative correction to the area law for the entanglement entropy. This contrasts with the pure area law valid at the infinite randomness fixed point in the diluted transverse Ising model in higher dimensions.

Yu-Cheng Lin; Ferenc Igloi; Heiko Rieger

2007-04-03

43

Exact scaling solutions and fixed points for general scalar field

We show that the most general dark energy model that possesses a scaling solution $\\rho_\\phi\\propto a^n$ is the k-essence model, which includes both of the quintessence and tachyon models. The exact scaling solutions are then derived. The potential that gives the tracking solution in which dark energy exactly tracks the background matter field is the inverse squared potential. The quintessence field with exponential potential can be obtained from the k-essence field with the inverse squared potential. We also find the fixed points and study their main properties, whereby the scalar field dominant fixed point is identified.

Yungui Gong; Anzhong Wang; Yuan-Zhong Zhang

2006-03-13

44

Measurement of thermodynamic temperature of high temperature fixed points

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.

Gavrilov, V. R.; Khlevnoy, B. B.; Otryaskin, D. A.; Grigorieva, I. A.; Samoylov, M. L.; Sapritsky, V. I. [All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), 46 Ozernaya St., Moscow 119361 (Russian Federation)] [All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), 46 Ozernaya St., Moscow 119361 (Russian Federation)

2013-09-11

45

Some Fixed Point Theorems in Multiplicative Metric Space

\\"Ozavsar and Cevikel (Fixed point of multiplicative contraction mappings on multiplicative metric space. arXiv:1205.5131v1 [matn.GN] (2012))initiated the notion of the multiplicative metric space such that the usual triangular inequality is replaced by "multiplicative triangle inequality $d(x,y)\\leq d(x,z).d(z,y)$ for all $x,y,z\\in X$". The objective of this manuscript is to derive some fixed point theorems in the context of multiplicative metric space.

Muhammad Sarwar; Badshah-e-Rome

2014-09-17

46

Oxides in metal fixed points of the ITS90

In the range between 0 °C and 961 °C, the International Temperature Scale of 1990 (ITS-90) depends to a great extent on the freezing points of the pure metals gallium, indium, tin, zinc, aluminium and silver. An up-to-date realization of these fixed points is based on cells containing metals of ultra-high purity (6N or better) and should include a correction

Martin Fahr; Steffen Rudtsch

2009-01-01

47

A Hybrid Common Fixed Point Theorem under Certain Recent Properties

We prove a common fixed point theorem for a hybrid pair of occasionally coincidentally idempotent mappings via common limit range property. Our result improves some results from the existing literature, especially the ones contained in Sintunavarat and Kumam (2009). Some illustrative and interesting examples to highlight the realized improvements are also furnished. PMID:24592191

Imdad, Mohammad

2014-01-01

48

Fixed Point Problems for Linear Transformations on Pythagorean Triples

ERIC Educational Resources Information Center

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*…

Zhan, M.-Q.; Tong, J.-C.; Braza, P.

2006-01-01

49

A BROUWER FIXED POINT THEOREM FOR GRAPH ENDOMORPHISMS

history. Brouwer's theorem follows from Lefschetz because a manifold M homeomorphic to the unit ball has assures that any continuous transformation on the closed ball in Euclidean space has a fixed point. First [17, 25, 16]. It has its use for example in game theory: the Kakutani generalization [28] has been

Knill, Oliver

50

Fixed points, stable manifolds, weather regimes, and their predictability

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.

Deremble, Bruno; D'Andrea, Fabio; Ghil, Michael [Univ. of California, Los Angeles, CA (United Staes). Atmospheric and Oceanic Sciences and Institute of Geophysics and Planetary Physics

2009-10-27

51

On String Theory Duals of Lifshitz-like Fixed Points

We present type IIB supergravity solutions which are expected to be dual to certain Lifshitz-like fixed points with anisotropic scale invariance. They are expected to describe a class of D3-D7 systems and their finite temperature generalizations are straightforward. We show that there exist solutions that interpolate between these anisotropic solutions in the IR and the standard AdS5 solutions in the UV. This predicts anisotropic RG flows from familiar isotropic fixed points to anisotropic ones. In our case, these RG flows are triggered by a non-zero theta-angle in Yang-Mills theories that linearly depends on one of the spatial coordinates. We study the perturbations around these backgrounds and discuss the possibility of instability. We also holographically compute their thermal entropies, viscosities, and entanglement entropies.

Tatsuo Azeyanagi; Wei Li; Tadashi Takayanagi

2009-05-06

52

Expressive Equivalence of Least and Inflationary Fixed-Point Logic

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

Stephan Kreutzer; RWTH Aachen

2002-01-01

53

Approximately J?-homomorphisms: A fixed point approach

NASA Astrophysics Data System (ADS)

The functional equation (?) is stable if any function g satisfying the equation (?)approximately is near to the true solution of (?). A functional equation is superstable if every solution satisfying the equation approximately is an exact solution of it. Using fixed point methods, we prove the stability and superstability of J?-homomorphisms between J?-algebras for the generalized Jensen-type functional equation f({x+y}/{2})+f({x-y}/{2})=f(x).

Eshaghi Gordji, M.; Najati, A.

2010-05-01

54

Fixed points of multiplicative contraction mappings on multiplicative metric spaces

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

Muttalip Ozavsar; Adem Cengiz Cevikel

2012-05-23

55

The Dynamics of Multidimensional Secession: Fixed Points and Ideological Condensation

NASA Astrophysics Data System (ADS)

We explore a generalized, stochastic seceder model of societal dynamics with variable size polling groups and higher-dimensional opinion vectors, revealing its essential modes of self-organized segregation. Renormalizing to a discrete, deterministic version, we pin down the upper critical size of the sampling group and analytically uncover a self-similar hierarchy of dynamically stable, multiple-branch fixed points. In d?3, the evolving, coarsening population suffers collapse to a 2D ideological plane.

Soulier, Arne; Halpin-Healy, Tim

2003-06-01

56

Impurity and thermal modelling of SPRT fixed-points

NASA Astrophysics Data System (ADS)

Impurities in pure metal fixed points for the calibration of standard platinum resistance thermometers (SPRTs) causes significant variations in the freezing temperature, of the order of sub-mK to several mK. This often represents the largest contribution to the overall uncertainty of the fixed point temperature, and it is therefore of great interest to explore ways of correcting for this effect. The sum of individual estimates (SIE) method, in which the contributions of all the impurities are summed, is the recommended way of determining the correction if one has an accurate knowledge of the impurities present and their low concentration liquidus slopes. However, due to the difficulty in obtaining reliable iningot impurity corrections, it remains useful to investigate the influence of impurities on freezing curves using modeling techniques, and ultimately to parameterize the freezing curve by e.g. least-squares fitting to make corrections to the temperature of the freeze. Some success in analyzing freezing curves has been achieved. When parameterizing experimentally determined freezing curves, it is necessary to reliably determine the freezing end-point, and minimize spurious thermal effects. We outline some methods for meeting these requirements. As the influence of impurities is always convolved with thermal influences it is instructive to construct a model which takes into account both heat and impurity transport. We describe the development of more sophisticated models which take both these effects into account.

Pearce, J. V.; Veltcheva, R. I.; Large, M. J.

2013-09-01

57

Quenched spectroscopy with fixed-point and chirally improved fermions

We present results from quenched spectroscopy calculations with the parametrized fixed-point and the chirally improved Dirac operators. Both these operators are approximate solutions of the Ginsparg-Wilson equation and have good chiral properties. This allows us to work at small quark masses and we explore pseudoscalar-mass to vector-mass ratios down to 0.28. We discuss meson and baryon masses, their scaling properties, finite volume effects and compare our results with recent large scale simulations. We find that the size of quenching artifacts of the masses is strongly correlated with their experimentally observed widths and that the gauge and hadronic scales are consistent.

BGR Collaboration; Christof Gattringer; Meinulf Gockeler; Peter Hasenfratz; Simon Hauswirth; Kieran Holland; Thomas Jorg; Keisuke J. Juge; C. B. Lang; Ferenc Niedermayer; P. E. L. Rakow; Stefan Schaefer; Andreas Schafer

2003-07-08

58

Quenched QCD with fixed-point and chirally improved fermion

In this contribution we present results from quenched QCD simulations with the parameterized fixed-point (FP) and the chirally improved (CI) Dirac operator. Both these operators are approximate solutions of the Ginsparg-Wilson equation and have good chiral properties. We focus our discussion on observables sensitive to chirality. In particular we explore pion masses down to 210 MeV in light hadron spectroscopy, quenched chiral logs, the pion decay constant and the pion scattering length. We discuss finite volume effects, scaling properties of the FP and CI operators and performance issues in their numerical implementation.

Christof Gattringer; Meinulf Göckeler; Peter Hasenfratz; Simon Hauswirth; Kieran Holland; Thomas Jörg; K. J. Juge; C. B. Lang; Ferenc Niedermayer; P. E. L. Rakow; Stefan Schaefer; Andreas Schäfer

2002-09-10

59

TCP over OBS - fixed-point load and loss.

The sending rate of commonly used TCP protocols is tightly coupled to packet loss within the network: a high rate of packet loss will cause a sender to slow down, thereby reducing the network load and decreasing subsequent packet loss rates. In this paper, we combine a widely verified source rate TCP model with an Optical Burst Switching (OBS) loss model, to find fixed-point input loads and loss rates for an OBS link carrying TCP traffic. In doing so, we show that if OBS networks are to be efficiently used to carry TCP traffic, many wavelengths with full wavelength conversion are required. PMID:19503115

Cameron, Craig; Le Vu, Hai; Choi, Jung; Bilgrami, Syed; Zukerman, Moshe; Kang, Minho

2005-11-14

60

Remarks on a fixed point theorem of Caristi

1977) David Lee Egle, B . S . , Pan American University Chairman of Advisory Committee: L. F. Guseman, Jr. Let (X, d) be a complete metric space and f a selfmap of X. It is shown that various known theorems on the existence of fixed and periodic... CHAPTER 0 INTRODUCTION Let (X, d) be a metric space and let f be a selfmap of X; that is, f : X ~ X. Let N denote the positive integers and R the nonnegative real numbers. The ~se uence of iterates of f at point x X is the sec en e defined by f (x...

Egle, David Lee

2012-06-07

61

Instantons and the fixed point topological charge in the two-dimensional O(3) sigma-model

We define a fixed point topological charge for the two-dimensional O(3) lattice sigma-model which is free of topological defects. We use this operator in combination with the fixed point action to measure the topological susceptibility for a wide range of correlation lengths. The results strongly suggest that it is not a physical quantity in this model. The procedure, however, can be applied to other asymptotically free theories as well.

Marc Blatter; Rudolf Burkhalter; Peter Hasenfratz; Ferenc Niedermayer

1995-08-29

62

A Floating-point to Fixed-point C Converter for Fixed-point Digital Signal Processors

An automatic scaling C program translator is developed for the efficient execution of application programs infixed-point digital signal processors. The program for range estimation is automatically generated by insertingcodes which collect the statistics of each signal during the simulation. With the range information, the number ofshifts needed for the scaling is determined and the floating-point program is converted to a

Ki-il Kum; Jiyang Kang

1997-01-01

63

Attracting fixed points for heavy particles in the vicinity of a vortex pair

NASA Astrophysics Data System (ADS)

We study the behavior of heavy inertial particles in the flow field of two like-signed vortices. In a frame co-rotating with the two vortices, we find that stable fixed points exist for these heavy inertial particles; these stable frame-fixed points exist only for particle Stokes number St < Stcr. We estimate Stcr and compare this with direct numerical simulations, and find that the addition of viscosity increases the Stcr slightly. We find that the rate at which particles fall into the fixed points increases until the fixed points disappear at St = Stcr. These frame-fixed points are between fixed points and limit cycles in character.

Ravichandran, S.; Perlekar, Prasad; Govindarajan, Rama

2014-01-01

64

Fixed-point error analysis of Winograd Fourier transform algorithms

NASA Technical Reports Server (NTRS)

The quantization error introduced by the Winograd Fourier transform algorithm (WFTA) when implemented in fixed-point arithmetic is studied and compared with that of the fast Fourier transform (FFT). The effect of ordering the computational modules and the relative contributions of data quantization error and coefficient quantization error are determined. In addition, the quantization error introduced by the Good-Winograd (GW) algorithm, which uses Good's prime-factor decomposition for the discrete Fourier transform (DFT) together with Winograd's short length DFT algorithms, is studied. Error introduced by the WFTA is, in all cases, worse than that of the FFT. In general, the WFTA requires one or two more bits for data representation to give an error similar to that of the FFT. Error introduced by the GW algorithm is approximately the same as that of the FFT.

Patterson, R. W.; Mcclellan, J. H.

1978-01-01

65

The split common fixed-point problem for demicontractive mappings

NASA Astrophysics Data System (ADS)

Based on the very recent work by Censor and Segal (2009 J. Convex Anal. 16 587-600) and inspired by Xu (2006 Inverse Problems 22 2021-34) and Yang (2004 Inverse Problems 20 1261-6), we investigate an algorithm for solving the split common fixed-point problem for the class of demicontractive operators in a Hilbert space. Our results improve and/or develop previously discussed feasibility problems and related algorithms. It is worth mentioning that the convex feasibility formalism is at the core of the modeling of many inverse problems and has been used to model significant real-world problems, for instance, in sensor networks, in radiation therapy treatment planning, in computerized tomography and data compression, see Censor et al (2006 Phys. Med. Biol. 51 2353-65) and Combettes (1996 Adv. Imaging Electron. Phys. 95 155-270) and references therein.

Moudafi, A.

2010-05-01

66

A Fixed-Point Iteration Method with Quadratic Convergence

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.

Walker, Kevin P. [Engineering Science Software, Inc.; Sham, Sam [ORNL

2012-01-01

67

Fixed Point Transformations Based Iterative Control of a Polymerization Reaction

NASA Astrophysics Data System (ADS)

As a paradigm of strongly coupled non-linear multi-variable dynamic systems the mathematical model of the free-radical polymerization of methyl-metachrylate with azobis (isobutyro-nitrile) as an initiator and toluene as a solvent taking place in a jacketed Continuous Stirred Tank Reactor (CSTR) is considered. In the adaptive control of this system only a single input variable is used as the control signal (the process input, i.e. dimensionless volumetric flow rate of the initiator), and a single output variable is observed (the process output, i.e. the number-average molecular weight of the polymer). Simulation examples illustrate that on the basis of a very rough and primitive model consisting of two scalar variables various fixed-point transformations based convergent iterations result in a novel, sophisticated adaptive control.

Tar, József K.; Rudas, Imre J.

68

Coupled fixed point theorems for contractions in intuitionistic fuzzy normed spaces

Following the definition of coupled fixed point [T. G. Bhaskar, V. Lakshmikantham, Fixed point theorems in partially ordered metric spaces and applications, Nonlinear Anal. 65 (2006) 1379–1393], we prove a coupled fixed point theorem for contractive mappings in partially complete intuitionistic fuzzy normed spaces.

Madjid Eshaghi Gordji; Hamid Baghani; Yeol Je Cho

2011-01-01

69

70

24 CFR 50.16 - Decision points for policy actions.

Code of Federal Regulations, 2011 CFR

...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...

2011-04-01

71

24 CFR 50.16 - Decision points for policy actions.

Code of Federal Regulations, 2010 CFR

...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...

2010-04-01

72

24 CFR 50.16 - Decision points for policy actions.

Code of Federal Regulations, 2012 CFR

...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...

2012-04-01

73

24 CFR 50.16 - Decision points for policy actions.

Code of Federal Regulations, 2013 CFR

...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...

2013-04-01

74

Fixed-Point Optimization Utility for C and C Based Digital Signal Processing Programs

Fixed-point optimization utility software is devel- oped that can aid scaling and wordlength determination of digital signal processing algorithms written in C or C. This utility consists of two programs: the range estimator and the fixed-point simulator . The former estimates the ranges of floating- point variables for purposes of automatic scaling, and the latter translates floating-point programs into fixed-point

Seehyun Kim; Ki-Il Kum; Wonyong Sung

1998-01-01

75

Points fixes des applications compactes dans les espaces ULC

A topological space is locally equiconnected if there exists a neighborhood $U$ of the diagonal in $X\\times X$ and a continuous map $\\lambda:U\\times[0,1]\\to X$ such that $\\lambda(x,y,0)=x$, $\\lambda(x,y,1)=y$ et $\\lambda(x,x,t)=x$ for $(x,y)\\in U$ and $(x,t)\\in X\\times[0,1]$. This class contains all ANRs, all locally contractible topological groups and the open subsets of convex subsets of linear topological spaces. In a series of papers, we extended the fixed point theory of compact continuous maps, which was well developped for ANRs, to all separeted locally equiconnected spaces. This generalization includes a proof of Schauder's conjecture for compact maps of convex sets. This paper is a survey of that work. The generalization has two steps: the metrizable case, and the passage from the metrizable case to the general case. The metrizable case is, by far, the most difficult. To treat this case, we introduced in [4] the notion of algebraic ANR. Since the proof that metrizable locally equiconnected spaces are...

Cauty, Robert

2010-01-01

76

Holographic Duals of a Family of N=1 Fixed Points

We construct a family of warped AdS_5 compactifications of IIB supergravity that are the holographic duals of the complete set of N=1 fixed points of a Z_2 quiver gauge theory. This family interpolates between the T^{1,1} compactification with no three-form flux and the Z_2 orbifold of the Pilch-Warner geometry which contains three-form flux. This family of solutions is constructed by making the most general Ansatz allowed by the symmetries of the field theory. We use Killing spinor methods because the symmetries impose two simple projection conditions on the Killing spinors, and these greatly reduce the problem. We see that generic interpolating solution has a nontrivial dilaton in the internal five-manifold. We calculate the central charge of the gauge theories from the supergravity backgrounds and find that it is 27/32 of the parent N=2, quiver gauge theory. We believe that the projection conditions that we derived here will be useful for a much larger class of N=1 holographic RG-flows.

N. Halmagyi; K. Pilch; C. Romelsberger; N. P. Warner

2005-06-24

77

The $S^1$ fixed points in Quot-schemes and mirror principle computations

We describe the $S^1$-action on the Quot-scheme $\\\\Quot({\\\\cal E}^n)$ associated to the trivial bundle ${\\\\cal E}^n=CP^1\\\\times{\\\\smallBbb C}^n$. In particlular, the topology of the $S^1$-fixed-point components in $\\\\Quot({\\\\cal E}^n)$ and the $S^1$-weights of the normal bundle of these components are worked out. Mirror Principle, as developed by three of the current authors in the series of work [L-L-Y1, I, II, III,

Bong H. Lian; Chien-Hao Liu; Kefeng Liu; Shing-Tung Yau

2001-01-01

78

Some Extensions of Discrete Fixed Point Theorems and Their Applications to the Game Theory

NASA Astrophysics Data System (ADS)

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.

Kawasaki, Hidefumi

2009-09-01

79

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.

Jens Christian Claussen; Thorsten Mausbach; Alexander Piel; Heinz Georg Schuster

2006-09-20

80

Copper Fixed-Point Measurements for Radiation Thermometry at National Research Council

NASA Astrophysics Data System (ADS)

Due to its high transition temperature relative to other fixed points defined in the International Temperature Scale of 1990 (ITS-90) and its relatively low cost compared to silver and gold, copper is often chosen as the fixed point used to define the ITS-90 above 1235 K at national measurement institutes. Measurement of the copper freezing point can be done in a variety of furnaces. Although there are a large number of copper fixed-point designs, we expect the freezing temperatures to be the same. The difference between realizing different sized fixed points and the use of different furnaces in which to realize them is explored here. A traditional, large aperture fixed-point containing over 600 g of copper is compared to a hybrid-type fixed point containing only 15 g of copper and a commercial fixed point. Three types of furnaces including a heat-pipe furnace, a compact furnace, and a high-temperature blackbody were used to realize the copper freezing point. Between the fixed-point types, only the length of the plateau differed. However, a significant difference was found between the freezing temperatures determined in the different furnaces, and this difference was independent of cell type.

Todd, A. D. W.; Woods, D. J.

2014-07-01

81

System level fixed-point design based on an interpolative approach

The design process for fixed-point implementations eitherin software or in hardware requires a bit-true specificationof the algorithm in order to analyze quantization effectson an algorithmical level, abstracting from implementationaldetails.On the other hand, system design starts froma floating-point description into a fixed-point description becomesnecessary.Within this paper we present a tool thatallows an automated, interactive transformation from floating-pointANSI-C into a bit-true specification

Markus Willems; Volker Bürsgens; Holger Keding; Thorsten Grötker; Heinrich Meyr

1997-01-01

82

The resolution of field identification fixed points in diagonal coset theories

The fixed point resolution problem is solved for diagonal coset theories. The primary fields into which the fixed points are resolved are described by submodules of the branching spaces, obtained as eigenspaces of the automorphisms that implement field identification. To compute the characters and the modular S-matrix we use ‘orbit Lie algebras’ and ‘twining characters’, which were introduced in a

Jürgen Fuchs; Bert Schellekens; Christoph Schweigert

1996-01-01

83

The Hopfsaddlenode bifurcation for fixed points of 3Ddi#eomorphisms

The HopfÂsaddleÂnode bifurcation for fixed points of 3DÂdi#eomorphisms: a computer assisted phenomena are studied near a HopfÂsaddleÂnode (HSN) bifurcation of fixed points of 3D case is conÂ sidered here. A model map is obtained by a natural construction, through perÂ turbation

84

Hopf-saddle-node bifurcation for fixed points of 3D-diffeomorphisms

map G is constructed, such that at the central bifurcation the derivative has two complex conjugateHopf-saddle-node bifurcation for fixed points of 3D-diffeomorphisms: analysis of a resonance-saddle-node bifurcation of fixed points of diffeo- morphisms is analysed by means of a case study: a two-parameter model

Broer, H.W.

85

Many flavor QCD as exploration of the walking behavior with the approximate IR fixed point

We present the first report of the LatKMI collaboration on the the lattice QCD simulation performed at the KMI computer, "$\\varphi$", for the cases of 4 flavors and 8 flavors, the latter being expected to be a candidate for the walking technicolor having an approximate scale invariance near the infrared fixed point. The simulation was carried out based on the highly improved staggered quark (HISQ) action. In this proceedings, we report preliminary results on the spectrum, analyzed through the chiral perturbation theory and the finite-size hyperscaling. We observe qualitatively different behavior of the 8-flavor case in contrast to the 4-flavor case which shows clear indication of the hadronic phase as in the usual QCD.

Yasumichi Aoki; Tatsumi Aoyama; Masafumi Kurachi; Toshihide Maskawa; Kei-ichi Nagai; Hiroshi Ohki; Akihiro Shibata; Koichi Yamawaki; Takeshi Yamazaki

2012-02-21

86

Comparison of realizations of Re-C fixed points filled and measured at NPL and NRC

NASA Astrophysics Data System (ADS)

A Re-C fixed point was filled at the National Physical Laboratory (NPL), UK and its melting temperature compared to a fixed point that had been filled previously at NPL. Both of these fixed points were of the hybrid type and used a purified graphite foil between the sacrificial graphite sleeve and the outer crucible. The melting temperatures of these two fixed points were compared and found to agree within the comparison uncertainties. Another Re-C fixed point was filled at the National Research Council (NRC), Canada. This fixed point was also of the hybrid type but contained carbon-composite sheet as the liner between the sleeve and the outer crucible. The melting temperatures of the fixed point filled at NPL and the one filled at NRC were compared and found to agree within the uncertainties of the comparison. When the ITS-90 temperatures at the Re-C melting point (˜ 2474 °C) measured at NPL were compared to those measured at NRC they were also found to agree within the uncertainties of their respective scales.

Todd, A. D. W.; Lowe, D. H.; Dong, W.; Woods, D. J.

2013-09-01

87

A New Co-C Eutectic Fixed-Point Cell for Thermocouple Calibration at

NASA Astrophysics Data System (ADS)

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.

Failleau, G.; Deuzé, T.; Jouin, D.; Mokdad, S.; Briaudeau, S.; Sadli, M.

2014-07-01

88

NASA Astrophysics Data System (ADS)

Above the freezing point of silver (961.78 °C), the International Temperature Scale of 1990 is defined in terms of Planck's radiation law. The scale is maintained and disseminated using a validated and linear pyrometer in conjunction with a blackbody reference source at either the Ag, Au (1064.18 °C) or Cu (1084.62 °C) freezing point. In order to realize the scale with the highest precision high quality, well-characterised, reproducible fixed-point blackbody sources are required. Such sources have been maintained at NPL for a number of years, but it was felt that improvements to the design would be beneficial. A new Ag point blackbody source has therefore been constructed. The new design will improve the quality and reproducibility of the melting and freezing plateaux and reduce errors due to the `out-of-focus' size-of-source effect which is difficult to measure and to eliminate. Full details of the design of the new source, including results of the assessment of its performance, are described. Critical for the application of fixed-point blackbodies as primary temperature standards is the precise knowledge of the emissivity of the cavity, which causes a correction to the melting and freezing temperature of the ingot. As blackbody emissivities are difficult to assess experimentally, two different numerical approaches developed at NPL and PTB are used to calculate the blackbody emissivity. In order to further validate the performance of the new Ag fixed-point blackbody it has been compared with the Au primary fixed-point blackbody of PTB. For the comparison the ratios of the spectral radiances of the fixed-point blackbodies were measured at 650 nm and 950 nm using the PTB monochromator-based spectral radiance calibration facility, and at 654 nm and 953 nm using the PTB interference filter-based primary photoelectric pyrometer.

McEvoy, H. C.; Machin, G.; Friedrich, R.; Hartmann, J.; Hollandt, J.

2003-09-01

89

Floating to Fixed-Point Refinement in Matlab with an Object-Oriented Library

An object-oriented fixed-point library for Matlab has been developed. We present a design flow for DSP ASIC applications where this library is used for floating- to fixed-point refinement. Matlab is chosen for its excellence and popularity in system design and modeling. The library allows a system designer to model e.g. a receiver architecture with Matlab floating point operations and then

Henrik Olson; Axel Jantsch; Hannu Tenhunen

1999-01-01

90

Chiral Y junction of Luttinger liquid wires at weak coupling: Lines of stable fixed points

NASA Astrophysics Data System (ADS)

We calculate the conductances of a Y-junction setup of Luttinger liquid wires threaded by a magnetic flux, allowing for a different interaction strength g3?g in the third wire. The scattering matrix and the matrix of conductances are parametrized by three variables. For these we derive coupled renormalization group (RG) equations, up to second order in the interaction, within the scattering state formalism. The fixed point structure of these equations is analyzed in detail. For a repulsive interaction (g,g3>0) there is only one stable fixed point, corresponding to the complete separation of the wires. For an attractive interaction (g<0 and/or g3<0) four fixed points are found, whose stability depends on the interaction strength. For special values of the interaction parameters (a) g=0, g3<0 or (b) g3+g2/2=0, g<0 we find whole lines of stable fixed points. We conjecture that lines of fixed points appear generically at interfaces in the interaction coupling constant space separating two regions with different stable fixed points. We also find that in certain regions of the g-g3 plane the RG flow is towards a fixed point without chirality, implying that the effect of the magnetic flux is completely screened.

Aristov, D. N.; Wölfle, P.

2012-07-01

91

Common fixed points in best approximation for Banach operator pairs with Ciric type I-contractions

NASA Astrophysics Data System (ADS)

The common fixed point theorems, similar to those of Ciric [Lj.B. Ciric, On a common fixed point theorem of a Gregus type, Publ. Inst. Math. (Beograd) (N.S.) 49 (1991) 174-178; Lj.B. Ciric, On Diviccaro, Fisher and Sessa open questions, Arch. Math. (Brno) 29 (1993) 145-152; Lj.B. Ciric, On a generalization of Gregus fixed point theorem, Czechoslovak Math. J. 50 (2000) 449-458], Fisher and Sessa [B. Fisher, S. Sessa, On a fixed point theorem of Gregus, Internat. J. Math. Math. Sci. 9 (1986) 23-28], Jungck [G. Jungck, On a fixed point theorem of Fisher and Sessa, Internat. J. Math. Math. Sci. 13 (1990) 497-500] and Mukherjee and Verma [R.N. Mukherjee, V. Verma, A note on fixed point theorem of Gregus, Math. Japon. 33 (1988) 745-749], are proved for a Banach operator pair. As applications, common fixed point and approximation results for Banach operator pair satisfying Ciric type contractive conditions are obtained without the assumption of linearity or affinity of either T or I. Our results unify and generalize various known results to a more general class of noncommuting mappings.

Hussain, N.

2008-02-01

92

Feasibility-Based Bounds Tightening via Fixed Points

NASA Astrophysics Data System (ADS)

The search tree size of the spatial Branch-and-Bound algorithm for Mixed-Integer Nonlinear Programming depends on many factors, one of which is the width of the variable ranges at every tree node. A range reduction technique often employed is called Feasibility Based Bounds Tightening, which is known to be practically fast, and is thus deployed at every node of the search tree. From time to time, however, this technique fails to converge to its limit point in finite time, thereby slowing the whole Branch-and-Bound search considerably. In this paper we propose a polynomial time method, based on solving a linear program, for computing the limit point of the Feasibility Based Bounds Tightening algorithm applied to linear equality and inequality constraints.

Belotti, Pietro; Cafieri, Sonia; Lee, Jon; Liberti, Leo

93

Common fixed point theorems for maps under a contractive condition of integral type

NASA Astrophysics Data System (ADS)

Two common fixed point theorems for mapping of complete metric space under a general contractive inequality of integral type and satisfying minimal commutativity conditions are proved. These results extend and improve several previous results, particularly Theorem 4 of Rhoades [B.E. Rhoades, Two fixed point theorems for mappings satisfying a general contractive condition of integral type, Int. J. Math. Math. Sci. 63 (2003) 4007-4013] and Theorem 4 of Sessa [S. Sessa, On a weak commutativity condition of mappings in fixed point considerations, Publ. Inst. Math. (Beograd) (N.S.) 32 (46) (1982) 149-153].

Djoudi, A.; Merghadi, F.

2008-05-01

94

A floating-point to integer C program translator is developed for convenient programming and efficient use of fixed-point programmable digital signal processors (DSPs). It not only converts data types and supports automatic scaling, but also conducts shift optimization to enhance execution speed. Since the input and output of this translator are ANSI C compliant programs, it can be used for any

Ki-Il Kum; Jiyang Kang; Wonyong Sung

1999-01-01

95

Code of Federal Regulations, 2010 CFR

... false Operation of internal transmitter control systems through licensed fixed control points. 90.473 Section 90.473 Telecommunication...PRIVATE LAND MOBILE RADIO SERVICES Transmitter Control Internal Transmitter Control Systems §...

2010-10-01

96

ON GUPTA-BELNAP REVISION THEORIES OF TRUTH, KRIPKEAN FIXED POINTS, AND THE NEXT STABLE SET.

ON GUPTA-BELNAP REVISION THEORIES OF TRUTH, KRIPKEAN FIXED POINTS concepts associated with the revision theory* * of truth of Gupta and Belnap. We categorize) account of varied revision sequences - as a generalised algorit* *hmic theory of truth. This enables

Welch, Philip

97

Simulation-based word-length optimization method for fixed-point digital signal processing systems

Word-length optimization and scaling software that utilizes the fixed-point simulation results using realistic input signal samples is developed for the application to general, including nonlinear and time-varying, signal processing systems. Word-length optimization is conducted to minimize the hardware implementation cost while satisfying a fixed-point performance measure. In order to minimize the computing time, signal grouping and efficient search methods are

Wonyong Sung; Ki-Il Kum

1995-01-01

98

On Fixed-point theorems in Intuitionistic Fuzzy metric Space I

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

T. K. Samanta; Sumit Mohinta

2011-03-15

99

Influence of Impurities and Filling Protocol on the Aluminum Fixed Point

To improve the uncertainty of the aluminum fixed point, a study was launched by LNE-INM\\/CNAM in the framework of the EUROMET\\u000a Project 732 “Toward more accurate temperature fixed points” (Coordinating laboratory: LNE-INM\\/CNAM, 17 partner countries).\\u000a A new open cell was filled with aluminum of 99.99995% purity. A French laboratory carried out elemental analysis of the sample\\u000a using glow discharge-mass spectrometry

E. Renaot; M. H. Valin; M. Elgourdou

2008-01-01

100

Fixed Points, Nash Equilibria, and the Existential Theory of the Reals

Fixed Points, Nash Equilibria, and the Existential Theory of the Reals Marcus Schaefer School@cs.rochester.edu Abstract We introduce a new complexity class R based on the existential theory of the reals, and show points, Brouwer, existential theory of the real numbers, Nash equilibrium, computational complexity 1

Schaefer, Marcus

101

Cost-beneficial licensing action program at Turkey Point Plant

The Turkey Point plant cost-beneficial licensing action (CBLA) program focuses on safety-neutral regulatory issues that have the potential to require plant shutdown, derate, or preclude startup or that require operator workarounds to address.

Weinkam

1995-01-01

102

Cost-beneficial licensing action program at Turkey Point Plant

The Turkey Point plant cost-beneficial licensing action (CBLA) program focuses on safety-neutral regulatory issues that have the potential to require plant shutdown, derate, or preclude startup or that require operator workarounds to address.

Weinkam, E.J. [Florida Power and Light Company, Miami, FL (United States)

1995-12-31

103

Miniature Fixed-Point Cell Approaches for Monitoring of Thermocouple Stability

NASA Astrophysics Data System (ADS)

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.

Failleau, G.; Elliott, C. J.; Deuzé, T.; Pearce, J. V.; Machin, G.; Sadli, M.

2014-07-01

104

Miniature Fixed-Point Cell Approaches for {{\\varvec{In Situ}}} Monitoring of Thermocouple Stability

NASA Astrophysics Data System (ADS)

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 (961.78° C ; LNE-Cnam), the freezing point of copper (1084.62° C ; LNE-Cnam and NPL), and the melting point of Fe-C ({˜ }1154° 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.

Failleau, G.; Elliott, C. J.; Deuzé, T.; Pearce, J. V.; Machin, G.; Sadli, M.

2014-07-01

105

Fixed Point Results of Locally Contractive Mappings in Ordered Quasi-Partial Metric Spaces

Fixed point results for a self-map satisfying locally contractive conditions on a closed ball in an ordered 0-complete quasi-partial metric space have been established. Instead of monotone mapping, the notion of dominated mappings is applied. We have used weaker metric, weaker contractive conditions, and weaker restrictions to obtain unique fixed points. An example is given which shows that how this result can be used when the corresponding results cannot. Our results generalize, extend, and improve several well-known conventional results. PMID:24062629

Arshad, Muhammad; Ahmad, Jamshaid

2013-01-01

106

Fixed-Point Interactions and Renormalization Group Invariance in the Two-Nucleon System

NASA Astrophysics Data System (ADS)

We study the fixed-point interactions and the renormalization group invariance for an effective nucleon-nucleon (NN) interaction in the leading-order (LO) chiral effective field theory (ChEFT) renormalized within the framework of the subtracted kernel method (SKM) approach. By solving a nonrelativistic Callan-Symanzik (NRCS) equation we show how the driving term evolves with the subtraction scale to keep the T-matrix invariant. We calculate the fixed-point interaction from the driving term and compare the results obtained with and without its evolution through the NRCS equation.

Timóteo, V. S.; Szpigel, S.; Durães, F. O.

107

One loop beta functions and fixed points in higher derivative sigma models

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.

Percacci, Roberto; Zanusso, Omar [Perimeter Institute for Theoretical Physics, 31 Caroline St. North, Waterloo, Ontario N2J 2Y5 (Canada); SISSA, via Beirut 4, I-34014 Trieste (Italy) and INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste (Italy)

2010-03-15

108

Parallel Fixed Point Implementation of a Radial Basis Function Network in an FPGA

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

de Souza, Alisson C. D.; Fernandes, Marcelo A. C.

2014-01-01

109

Fixed Point Results for G-?-Contractive Maps with Application to Boundary Value Problems

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

Roshan, Jamal Rezaei

2014-01-01

110

A least-squares fixed-point iterative algorithm for multiple illumination photoacoustic tomography

The optical absorption of tissues provides important information for clinical and pre-clinical studies. The challenge in recovering optical absorption from photoacoustic images is that the measured pressure depends on absorption and local fluence. One reconstruction approach uses a fixed-point iterative technique based on minimizing the mean-squared error combined with modeling of the light source to determine optical absorption. With this technique, convergence is not guaranteed even with an accurate measure of optical scattering. In this work we demonstrate using simulations that a new multiple illumination least squares fixed-point iteration algorithm improves convergence - even with poor estimates of optical scattering. PMID:24156078

Harrison, Tyler; Shao, Peng; Zemp, Roger J.

2013-01-01

111

Parameter estimation by fixed point of function of information processing intensity

NASA Astrophysics Data System (ADS)

We present a new method of estimating the dispersion of a distribution which is based on the surprising property of a function that measures information processing intensity. It turns out that this function has a maximum at its fixed point. Fixed-point equation is used to estimate the parameter of the distribution that is of interest to us. The main result consists in showing that only part of available experimental data is relevant for the parameters estimation process. We illustrate the estimation method by using the example of an exponential distribution.

Jankowski, Robert; Makowski, Marcin; Piotrowski, Edward W.

2014-12-01

112

Parallel Fixed Point Implementation of a Radial Basis Function Network in an FPGA.

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

de Souza, Alisson C D; Fernandes, Marcelo A C

2014-01-01

113

Fixed Points of Contractive Mappings in b-Metric-Like Spaces

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

Hussain, Nawab; Roshan, Jamal Rezaei

2014-01-01

114

Fixed points of contractive mappings in b-metric-like spaces.

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

Hussain, Nawab; Roshan, Jamal Rezaei; Parvaneh, Vahid; Kadelburg, Zoran

2014-01-01

115

Combined GPS/GLONASS Precise Point Positioning with Fixed GPS Ambiguities

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

Pan, Lin; Cai, Changsheng; Santerre, Rock; Zhu, Jianjun

2014-01-01

116

Combined GPS/GLONASS Precise Point Positioning with Fixed GPS Ambiguities.

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

Pan, Lin; Cai, Changsheng; Santerre, Rock; Zhu, Jianjun

2014-01-01

117

The Critical Renormalization Fixed Point for Commuting Pairs of Area-Preserving Maps

NASA Astrophysics Data System (ADS)

We prove the existence of the critical fixed point ( F, G) for MacKay's renormalization operator for pairs of maps of the plane. The maps F and G commute, are area-preserving, reversible, real analytic, and they satisfy a twist condition.

Arioli, Gianni; Koch, Hans

2010-04-01

118

Three-element zoom lens with fixed distance between focal points.

This work deals with a theoretical analysis of zoom lenses with a fixed distance between focal points. Equations are derived for the primary (paraxial) design of the basic parameters of a three-element zoom lens. It is shown that the number of optical elements for such a lens must be larger than two. PMID:22739850

Mikš, Antonin; Novák, Ji?í; Novák, Pavel

2012-06-15

119

L-Fuzzy Fixed Points Theorems for L-Fuzzy Mappings via ??L-Admissible Pair

We define the concept of ??L-admissible for a pair of L-fuzzy mappings and establish the existence of common L-fuzzy fixed point theorem. Our result generalizes some useful results in the literature. We provide an example to support our result. PMID:24688441

Rashid, Maliha; Azam, Akbar

2014-01-01

120

Noise Probability Density Function in Fixed-Point Systems based on smooth operators

requires accuracy evaluation to ensure algorithm integrity. Indeed, fixed-point arithmetic generates deviations must be limited to ensure algorithm integrity and application performance. Application accuracy the system and degrade computing accuracy. In this paper, a method based on Generalized Gaussian PDF

Paris-Sud XI, UniversitÃ© de

121

FIXED POINTS OF COMPOSITIONS OF EARTHQUAKES FRANCESCO BONSANTE AND JEANMARC SCHLENKER

FIXED POINTS OF COMPOSITIONS OF EARTHQUAKES FRANCESCO BONSANTE AND JEANÂMARC SCHLENKER Abstract # r and E Âµ r be the right earthquakes on # and Âµ respectively. We show that the composition E # r # E estimates from the geometry of those AdS manifolds. 1. Introduction, main results 1.1. Earthquakes

Schlenker, Jean-Marc

122

FIXED POINTS OF COMPOSITIONS OF EARTHQUAKES FRANCESCO BONSANTE AND JEAN-MARC SCHLENKER

FIXED POINTS OF COMPOSITIONS OF EARTHQUAKES FRANCESCO BONSANTE AND JEAN-MARC SCHLENKER Abstract and EÂµ r be the right earthquakes on and Âµ respectively. We show that the composition E r EÂµ r has the geometry of those AdS manifolds. 1. Introduction, main results 1.1. Earthquakes. In this paper we consider

Schlenker, Jean-Marc

123

A Fixed Point Charge Model for Water Optimized to the Vapor-Liquid Coexistence Properties

@ipst.umd.edu #12;1 Abstract A new fixed-point charge potential model for water has been developed, targeting interactions in water, an intermolecular potential model valid over a broad range of densities and temperatures and their successful description of the structure of liquid water at near-ambient conditions. A Lennard-Jones potential

124

Is There a Curse of Dimensionality for Contraction Fixed Points in the Worst Case?

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

Traub, Joseph F.

125

A Linear Algorithm for Solving Fixed-Point Equations on Transition Systems

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].

Bart Vergauwen; Johan Lewi

1992-01-01

126

Convexity of a family of meromorphically univalent functions by using two fixed points

In this paper a new class of meromorphic univalent functions in terms of an integral operator Fc(z)=?01cvcf(vz)dv,(c?1), is defined. We find some properties of this new class by using two fixed points.

M. Eshaghi Gordji; Ali Ebadian

2009-01-01

127

A Fixed Point Analysis of a Gene Pool GA with Mutation Alden H. Wright

A Fixed Point Analysis of a Gene Pool GA with Mutation Alden H. Wright Computer Science University This paper analyzes a recombina- tion/mutation/selection genetic algorithm that uses gene pool recombination grant GR/R47394. repeated applications of crossover is a population in link- age equilibrium (also known

Wright, Alden H.

128

A Fixed Point Analysis of a Gene Pool GA with Mutation Alden H. Wright #

A Fixed Point Analysis of a Gene Pool GA with Mutation Alden H. Wright # Computer Science This paper analyzes a recombinaÂ tion/mutation/selection genetic algorithm that uses gene pool recombination by EPSRC grant GR/R47394. repeated applications of crossover is a population in linkÂ age equilibrium (also

Wright, Alden H.

129

A Constructive Fixed-Point Theorem and the Feedback Semantics of Timed Systems

is granted without fee provided that copies are not made or distributed for profit or commercial advantage Micro Program, and the following companies: Agilent, DGIST, General Motors, Hewlett Packard, Infineon: it provides a method to construct the unique fixed point through iteration. In this paper, we extend

130

Communications in Applied Analysis 16 (2012), no. 3, 377388 MULTIPLE FIXED POINT THEOREMS

1 Department of Mathematics and Computer Science, Concordia College, Moorhead, MN 56562 USA E-mail: andersod@cord.edu 2 College of Arts and Sciences, Dakota State University, Madison, SD 57042 USA E. Multiple fixed point theorems in the spirit of the original work of Leggett-Williams are created using

Anderson, Douglas R.

131

The Hopfsaddlenode bifurcation for fixed points of 3Ddi#eomorphisms

, to have a HSN bifurcation, one must impose certain generic conditions on the 3Âjet of the map F [8]. In [8] we construct and study a model family of 3D maps for the HSN bifurcation of fixed points of the model map, a quasiÂperiodic Hopf bifurcation of invariant circles occurs, where an invariant circle

132

Convergence theorems of fixed points for Lipschitz pseudo-contractions in Hilbert spaces

NASA Astrophysics Data System (ADS)

Let C be a closed convex subset of a real Hilbert space H and assume that T is a [kappa]-strict pseudo-contraction on C. Consider Mann's iteration algorithm given by It is proved that if the control sequence {[alpha]n} is chosen so that [kappa]<[alpha]n<1 and , then , where A=I-T and d(0,D) denotes the distance between the origin and the subset set D of H. As a consequence of this result, we prove that if T has a fixed point in C, then {xn} converges weakly to a fixed point of T. Also, we extend a result due to Reich to [kappa]-strict pseudo-contractions in the Hilbert space settingE Further, by virtue of hybridization projections, we establish a strong convergence theorem for Lipschitz pseudo-contractions. The results presented in this paper improve or extend the corresponding results of Browder and Petryshyn [F.E. Browder, W.V. Petryshyn, Construction of fixed points of nonlinear mappings in Hilbert spaces, J. Math. Anal. Appl. 20 (1967) 197-228], Rhoades [B.E. Rhoades, Fixed point iterations using infinite matrices, Trans. Amer. Math. Soc. 196 (1974) 162-176] and of Marino and Xu [G. Marino, H.-K. Xu, Weak and strong convergence theorems for strict pseudo-contractions in Hilbert spaces, J. Math. Anal. Appl. 329 (1) (2007) 336-346].

Zhou, Haiyun

2008-07-01

133

Quantum Corrected Drift-Diffusion Models: Solution Fixed Point Map and Finite Element Approximation

This article deals with the analysis of the functional iteration, denoted Generalized Gummel Map (GGM), proposed in (10) for the decoupled solution of the Quantum Drift-Diffusion (QDD) model. The solution of the problem is characterized as the fixed point of the GGM, which permits the establishment of a close link between the theoretical existence analysis and the implementation of a

Carlo de Falco; Joseph W. Jeromeb; Riccardo Sacco

2008-01-01

134

Control of transient chaos in tent maps near crisis. I. Fixed point targeting

Combinatorial techniques are applied to the symbolic dynamics representing transient chaotic behavior in tent maps in order to solve the problem of Ott-Grebogi-Yorke control to the nontrivial fixed point occurring in such maps. This approach allows ``preimage overlap'' to be treated exactly. Closed forms for both the probability of control being achieved and the average number of iterations to control

D. K. Arrowsmith

2000-01-01

135

Supergravity Solutions in the Low-$\\tan?$ $ ?_t$ Fixed Point Region

There has been much discussion in the literature about applying the radiative electroweak symmetry breaking (EWSB) requirement to GUT models with supergravity. We motivate and discuss the application of the EWSB requirement to the low $\\tan\\beta$ fixed-point region and describe the solutions we find.

V. Barger; M. S. Berger; P. Ohmann

1994-05-02

136

Collective fixed point theorem and coincidence theorems in FC-spaces

NASA Astrophysics Data System (ADS)

In this paper, we present a KKM type theorem, some coincidence theorems in FC-spaces and a collective fixed-point theorem for a family of set-valued mappings defined on the product space of locally FC-spaces. As applications, some intersection theorems and minimax theorems are proved. Our results improve and generalize some recent results.

He, Rong-Hua; Li, Hong-Xu

2009-03-01

137

ON GUPTA-BELNAP REVISION THEORIES OF TRUTH, KRIPKEAN FIXED POINTS, AND THE NEXT STABLE SET.

ON GUPTA-BELNAP REVISION THEORIES OF TRUTH, KRIPKEAN FIXED POINTS, AND THE NEXT STABLE SET. P.D.WELCH Abstract. We consider various concepts associated with the revision theory of truth of Gupta and Belnap. We of varied revision sequences - as a generalised algorithmic theory of truth. This enables something

Welch, Philip

138

ON GUPTABELNAP REVISION THEORIES OF TRUTH, KRIPKEAN FIXED POINTS, AND THE NEXT STABLE SET.

ON GUPTAÂBELNAP REVISION THEORIES OF TRUTH, KRIPKEAN FIXED POINTS, AND THE NEXT STABLE SET. P.D.WELCH Abstract. We consider various concepts associated with the revision theory of truth of Gupta and Belnap. We of varied revision sequences Â as a generalised algorithmic theory of truth. This enables something

Welch, Philip

139

Comparison of the copper blackbody fixed-point cavities between NIS and LNE-Cnam

NASA Astrophysics Data System (ADS)

This paper describes the results of a bilateral comparison at the copper blackbody fixed point (1084.62 °C), one of the defining fixed points of the International Temperature Scale of 1990 in the high-temperature range. The ‘National Institute of Standards—Egypt (NIS)’ and the ‘Laboratoire Commun de Métrologie--France (LNE-Cnam)’ undertook such a comparison using an NIS linear pyrometer ‘LP4’ as a circulating radiation thermometer between the two laboratories. The main objective of this work was to compare the realizations of the copper blackbody fixed point for radiation thermometers and establish the level of agreement between the two laboratories in the high-temperature range. The comparison measurements revealed a slightly lower temperature of the NIS copper point than that of the LNE-Cnam copper point by about 0.08 °C. This difference is not significant with regard to the uncertainty and the stability of the pyrometer estimated as 0.15 °C. A second comparison was made a few months later by comparing simultaneously the two copper points at the LNE-Cnam premises. This comparison allowed determining a temperature difference of 0.045 ± 0.030 °C between the two cells, with the temperature of the LNE-Cnam cell being higher than that of NIS.

Ahmed, M. G.; Ali, K.; Bourson, F.; Sadli, M.

2013-09-01

140

Bilateral ITS-90 comparison at WC-C peritectic fixed point between NIM and NPL

NASA Astrophysics Data System (ADS)

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.

Dong, W.; Lowe, D. H.; Lu, X.; Machin, G.; Yuan, Z.; Wang, T.; Bloembergen, P.; Xiao, C.

2013-09-01

141

``MULTICELLS'': A European Project on Cryogenic Temperature Fixed Points in Sealed Cells

NASA Astrophysics Data System (ADS)

In January 2000 a European Project called "MULTICELLS" started, in the field of the realisation of temperature standard fixed points in the range (2.18 to 216.6) K, ending in April 2003. Two lines of cell design were developed for both modular multi-component cells (IMGC and INM down to 13.8 K) and 4He lambda-point cells (IMGC and PTB). The cells were tested mainly by INTiBS, NMi, NPL, and PTB. Studies were performed on the thermal design and to improve the knowledge of the underlying physical chemistry, with the goal of reducing the overall uncertainty budget to less than 0.1 mK. This involved also the comparison of the new modular multi-component cells, which are made of several elements—each realising one different fixed point, e.g., e-H2, Ne, O2, and Ar, but also D2, N2 and CO2— mounted on a common frame where the thermometers are fitted, with the previous-generation cells. The new cells represent a substantial improvement in the state-of-the-art of the realisation of these fixed points and of their use for the realisation of the ITS-90 and for thermometric checkpoints. A self-contained cryogenic-free computer-run cryostat is under development as the final stage of the Project for measuring the modular cells and for thermometer intercomparison.

Pavese, F.; Fellmuth, B.; Head, D.; Hermier, Y.; Peruzzi, A.; Szmyrka Grzebyk, A.; Zanin, L.

2003-09-01

142

Tympanic thermometer performance validation by use of a body-temperature fixed point blackbody

NASA Astrophysics Data System (ADS)

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.

Machin, Graham; Simpson, Robert

2003-04-01

143

Probability of local bifurcation type from a fixed point: A random matrix perspective

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.

D. J. Albers; J. C. Sprott

2005-10-24

144

Comparison of Co-C eutectic fixed-point cells between VNIIM and VNIIOFI

NASA Astrophysics Data System (ADS)

Two national metrological institutes of the Russian Federation, VNIIM and VNIIOFI, take part in the international research plan of CCT WG5 for investigation of high-temperature fixed points (HTFP). In the framework of this CCT-WG5 HTFP Research Plan the both institutes have designed and built independently cobalt-carbon (Co-C) eutectic radiation cells. The comparison of the Co-C cells developed by the institutes was carried out with the aim of determination of a difference in the melting temperature due to difference in the constructional characteristics of the cells. The radiance-mode radiation thermometers with central wavelength nearby 650 nm were used for the fixed-point melting temperature measurements. The article presents preliminary results of the comparison, which shows agreement between melting temperature of the compared cells within 20 mK. The details of the comparison are reported.

Sild, Y.; Khlevnoy, B.; Matveyev, M.; Grigorieva, I. A.; Fuksov, V. M.

2013-09-01

145

Une g\\'en\\'eralisation de la conjecture de point fixe de Schauder

We prove the following generalisation of Schauder's fixed point conjecture: Let $C_1,...,C_n$ be convex subsets of a Hausdorff topological vector space. Suppose that the $C_i$ are closed in $C=C_1\\cup...\\cup C_n$. If $f:C\\to C$ is a continuous function whose image is contained in a compact subset of $C$, then its Lefschetz number $\\Lambda(f)$ is defined. If $\\Lambda(f)\

Cauty, Robert

2012-01-01

146

Application of fixed point theory to chaotic attractors of forced oscillators

A review of the structure of chaotic attractors of periodically forced second-order nonlinear oscillators suggests that the\\u000a theory of fixed points of transformations gives information about the fundamental topological structure of attractors. First\\u000a a simple extension of the Levinson index formula is proved. Then numerical evidence is used to formulate plausible conjectures\\u000a about absorbing regions containing chaotic attractors in forced

H. Bruce Stewart

1991-01-01

147

Quantization analysis for fixed-point implementation of speech processing for the hearing impaired

Over the past decade, real time digital signal processing (DSP) has found several new applications in the biomedical arena. One of these has been in the area of hearing aids. This paper presents quantization analysis of speech processing algorithms, for the hearing impaired, for implementation on Texas Instruments' (TI) TMS320C54x (C54x) fixed point DSP chip. These algorithms were initial implemented

N. Magotra; S. Bangalore; S. Savadatti; P. Kasthuri; S. Divakar; T. Stetzler; P. Gelabert

1999-01-01

148

Wilson, fixed point and Neuberger's lattice Dirac operator for the Schwinger model

NASA Astrophysics Data System (ADS)

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.

Farchioni, F.; Hip, I.; Lang, C. B.

1998-12-01

149

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

F. Edler; A. C. Baratto

2006-01-01

150

AMSC/CMSC 466 Tobias von Petersdorff 1 Fixed Point Iteration and Contraction Mapping Theorem

AMSC/CMSC 466 Tobias von Petersdorff 1 Fixed Point Iteration and Contraction Mapping Theorem-posteriori error estimate x(k) -x q 1-q x(k) -x(k-1) (3) #12;AMSC/CMSC 466 Tobias von Petersdorff Proof. Pick x(0 that a given mapping g is a contraction, see the examples in sections 1.5, 1.6. #12;AMSC/CMSC 466 Tobias von

von Petersdorff, Tobias

151

Fast, Accurate Static Analysis for Fixed-Point Finite-Precision Effects in DSP Designs

Translating digital signal processing (DSP) software intoits finite-precision hardware implementation is often a time-consumingtask. We describe a new static analysis techniquethat can accurately analyze finite-precision effects arisingfrom fixed-point implementations of DSP algorithms.The technique is based on recent interval representation methodsfrom affine arithmetic, and the use of new probabilisticbounds. The resulting numerical error estimates are comparableto detailed statistical simulation, but achieve

Claire Fang Fang; Rob A. Rutenbar; Tsuhan Chen

2003-01-01

152

Long-Term Monitoring of Thermocouple Stability with Miniature Fixed-Point Cells

NASA Astrophysics Data System (ADS)

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.

Elliott, C. J.; Failleau, G.; Deuzé, T.; Sadli, M.; Pearce, J. V.; Machin, G.

2014-04-01

153

NASA Astrophysics Data System (ADS)

Most computers in the past have been equipped with floating point processing capabilities, allowing an easy and brute-force solution for the machine computation errors, not requiring any specific tailoring of the computation in nearly hundred percent of situations. However, the computation needed for the adaptive optics real-time control in 30-50 meter telescopes is big enough to cause trouble to conventional von-Neumann processors, even if Moore's Law is valid for the next years. Field Programmable Gate Array (FPGAs) have been proposed as a viable alternative to cope with such computation needs[1,2], but--at least today's chips--will require fixed-point arithmetic to be used instead. It is then important to evaluate up to what point the accuracy and stability of the control system will be affected by this limitation. This paper presents the simulation and laboratory results of the comparison between both arithmetics, specifically evaluated in an adaptive optics system. The real-time controller has been modeled as black box having as input the wavefront sensor camera digital output data, providing a digital output to the actuators of the deformable mirror, and with the task of internally computing all outputs from the inputs. MATLAB fixed-point library has been used to evaluate the effect of different precision lengths (5-10 fractional bits) in the computation of the Shack-Hartmann subaperture centroid, in comparison with the reference 64-bit floating-point arithmetic and with the noise floor of the real system, concluding that the effect of the limited precision can be overcome by adequately selecting the number of fractional bits used in the representation, and tailoring that number with the needs at every step of the algorithm.

Martín-Hernando, Yolanda; Rodríguez-Ramos, Luis F.; Garcia-Talavera, Marcos R.

2008-07-01

154

Nonthermal fixed points, vortex statistics, and superfluid turbulence in an ultracold Bose gas

NASA Astrophysics Data System (ADS)

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.

Nowak, Boris; Schole, Jan; Sexty, Dénes; Gasenzer, Thomas

2012-04-01

155

algorithm integrity and application performances. Application accuracy can be evaluated through differentANALYTICAL ACCURACY EVALUATION OF FIXED-POINT SYSTEMS Romuald Rocher, Daniel Menard, Olivier be con- verted into a fixed-point specification. This conversion re- quires accuracy evaluation to ensure

Paris-Sud XI, UniversitÃ© de

156

Ultraviolet fixed point and massive composite particles in TeV scales

NASA Astrophysics Data System (ADS)

We present a further study of the dynamics of high-dimension fermion operators attributed to the theoretical inconsistency of the fundamental cutoff (quantum gravity) and the parity-violating gauge symmetry of the standard model. Studying the phase transition from a symmetry-breaking phase to a strong-coupling symmetric phase and the ?-function behavior in terms of four-fermion coupling strength, we discuss the critical transition point as a ultraviolet-stable fixed point where a quantum field theory preserving the standard model gauge symmetry with composite particles can be realized. The form-factors and masses of composite particles at TeV scales are estimated by extrapolating the solution of renormalization-group equations from the infrared-stable fixed point where the quantum field theory of standard model is realized and its phenomenology including Higgs mass has been experimentally determined. We discuss the probability of composite-particle formation and decay that could be experimentally verified in the LHC by measuring the invariant mass of relevant final states and their peculiar kinetic distributions.

Xue, She-Sheng

2014-10-01

157

Influence of Impurities and Filling Protocol on the Aluminum Fixed Point

NASA Astrophysics Data System (ADS)

To improve the uncertainty of the aluminum fixed point, a study was launched by LNE-INM/CNAM in the framework of the EUROMET Project 732 “Toward more accurate temperature fixed points” (Coordinating laboratory: LNE-INM/CNAM, 17 partner countries). A new open cell was filled with aluminum of 99.99995% purity. A French laboratory carried out elemental analysis of the sample using glow discharge-mass spectrometry (GD-MS). The values of the equilibrium distribution coefficient k and of the derivative {? T_{{l}}/? ci_{{l}}} of the temperature of the liquidus line with respect to the concentration of impurity i will be obtained through collaboration with a French physical and chemical laboratory. In the past, some aluminum cells were opened after several melts and freezes. The aluminum ingot was sticking to the graphite crucible, indicating that physicochemical reactions had likely occurred between Al and C. To avoid this reaction, an effort was made to draw benefit from the Al2O3 film that appears immediately on the surface of the aluminum ingot when it is exposed to oxygen. The open aluminum cell was tested in different furnaces and with different thermal insulator arrangements inside the fixed-point assembly. The observed drifts of the plateaux were always larger than the expected values. The cell was opened to inspect the aluminum ingot. The ingot was extracted easily, since no sticking to the crucible had occurred. The aluminum showed a very bright surface, but the presence of many “craters” throughout the thickness of the ingot was surprising. In some cases, the thermometer well was even apparent.

Renaot, E.; Valin, M. H.; Elgourdou, M.

2008-06-01

158

Uncertainty due to non-linearity in radiation thermometers calibrated by multiple fixed points

NASA Astrophysics Data System (ADS)

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.

Yamaguchi, Y.; Yamada, Y.

2013-09-01

159

Material parameter extraction for terahertz time-domain spectroscopy using fixed-point iteration

NASA Astrophysics Data System (ADS)

A simple method to extract the far-infrared dielectric parameters of a homogeneous material from terahertz signals is explored in this paper. Provided with a reference, sample-probing terahertz signal and a known sample thickness, the method can determine the underlying complex refractive index of the sample within a few iterations based on the technique of fixed-point iteration. The iterative process is guaranteed to converge and gives the correct parameters when the material thickness exceeds 200 ?m at a frequency of 0.1 THz or 20 ?m at a frequency of 1.0 THz.

Withayachumnankul, W.; Ferguson, B.; Rainsford, T.; Mickan, S. P.; Abbott, D.

2005-07-01

160

An experimental study on ship detection based on the fixed-point polarimetric whitening filter

NASA Astrophysics Data System (ADS)

This work investigates the fixed-point polarimetric whitening filter (FP-PWF) with respect to ship detection based on polarimetric synthetic aperture radar (SAR) imagery. The purposes of this work are: (i) to investigate the FP-PWF algorithm that incorporate texture, (ii) to examine the method of log-cumulants (MoLC) for shape parameter estimation associated with texture, and (iii) to assess the impact of the improved modeling and estimation on the discrepancy between specified and observed false alarm rate. A modified ship detection algorithm based on FP-PWF is proposed with improved modeling, estimation and detection performance. Experiments are performed on simulated radar ocean clutter.

Tao, Ding; Brekke, Camilla; Anfinsen, Stian Normann

2011-11-01

161

Vertex functions and infrared fixed point in Landau gauge SU(N) Yang-Mills theory

The infrared behaviour of vertex functions in an SU(N) Yang-Mills theory in Landau gauge is investigated employing a skeleton expansion of the Dyson-Schwinger equations. The three- and four-gluon vertices become singular if and only if all external momenta vanish while the dressing of the ghost-gluon vertex remains finite in this limit. The running coupling as extracted from either of these vertex functions possesses an infrared fixed point. In general, diagrams including ghost-loops dominate in the infrared over purely gluonic ones.

Alkofer, R; Llanes-Estrada, F J; Alkofer, Reinhard; Fischer, Christian S.; Llanes-Estrada, Felipe J.

2005-01-01

162

Vertex functions and infrared fixed point in Landau gauge SU(N) Yang-Mills theory

The infrared behaviour of vertex functions in an SU(N) Yang-Mills theory in Landau gauge is investigated employing a skeleton expansion of the Dyson-Schwinger equations. The three- and four-gluon vertices become singular if and only if all external momenta vanish while the dressing of the ghost-gluon vertex remains finite in this limit. The running coupling as extracted from either of these vertex functions possesses an infrared fixed point. In general, diagrams including ghost-loops dominate in the infrared over purely gluonic ones.

Reinhard Alkofer; Christian S. Fischer; Felipe J. Llanes-Estrada

2004-12-30

163

Search for the IR fixed point in the Twisted Polyakov Loop scheme (II)

We measure the renormalized coupling in the Twisted Polyakov loop scheme for SU(3) gauge theory coupled with $N_f=12$ fundamental fermions. To find the infrared fixed point of this theory, we focus on the step scaling function for the renormalized coupling. We take the continuum limit using the linear function of $(a/L)^2$ and a constant fit function. We find that there is a sizeable systematic error due to the choice of the continuum extrapolation function in the low energy region. We will give some directions to reduce the systematic errors.

Etsuko Itou; Tatsumi Aoyama; Masafumi Kurachi; C. -J. David Lin; Hideo Matsufuru; Hiroshi Ohki; Tetsuya Onogi; Eigo Shintani; Takeshi Yamazaki

2010-11-02

164

Search for the IR fixed point in the twisted Polyakov loop scheme

We present a non-perturbative study of the running coupling constant in the Twisted Polyakov Loop (TPL) scheme. We investigate how the systematic and statistical errors can be controlled {\\it via} a feasibility study in SU(3) pure Yang-Mills theory. We show that our method reproduces the perturbative determination of the running coupling in the UV. In addition, our numerical result agrees with the theoretical prediction of this coupling constant in the IR. We also present our preliminary results for $N_f=12$ QCD, where an IR fixed point may be present.

Erek Bilgici; Antonino Flachi; Etsuko Itou; Masafumi Kurachi; C. -J. David Lin; Hideo Matsufuru; Hiroshi Ohki; Tetsuya Onogi; Eigo Shintani; Takeshi Yamazaki

2009-10-21

165

Finiteness of fixed equilibrium configurations of point vortices in the plane with a background flow

NASA Astrophysics Data System (ADS)

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).

Cheung, Pak-Leong; Ng, Tuen Wai

2014-10-01

166

Development of a new radiometer for the thermodynamic measurement of high temperature fixed points

NASA Astrophysics Data System (ADS)

The National Physical Laboratory (NPL) has developed a new radiometer to measure the thermodynamic melting point temperatures of high temperature fixed points with ultra-low uncertainties. In comparison with the NPL's Absolute Radiation Thermometer (ART), the "THermodynamic Optical Radiometer" (THOR) is more portable and compact, with a much lower size-of-source effect and improved performance in other parameters such as temperature sensitivity. It has been designed for calibration as a whole instrument via the radiance method, removing the need to calibrate the individual subcomponents, as required by ART, and thereby reducing uncertainties. In addition, the calibration approach has been improved through a new integrating sphere that has been designed to have greater uniformity.

Dury, M. R.; Goodman, T. M.; Lowe, D. H.; Machin, G.; Woolliams, E. R.

2013-09-01

167

A Method to Improve the Temperature Distribution of Holder Around the Fixed-Point Cell Position

NASA Astrophysics Data System (ADS)

The temperature profile along the furnaces used in heating high-temperature fixed points has a crucial impact on the quality and duration of melting plateaux, accordingly the accuracy of thermodynamic temperature determination of such fixed points. This paper describes a simple, yet efficient, approach for improving the temperature uniformity along a cell holder in high-temperature blackbody (HTBB) furnaces that use pyrolytic graphite rings as heating elements. The method has been applied on the KRISS' HTBB furnace. In this work, an ideal solution for arranging the heating elements inside the furnace is presented by which the temperature gradient across the cell holder can be kept as low as possible. Numerical calculations, based on a finite element method, have been carried out to find the best possible arrangement of the rings. This has been followed by measuring the temperature gradient along an empty cell holder to validate our calculations. A temperature gradient of 100 mK has been achieved at over a length of 50 mm within a cell holder of 10 cm in length. It has also been shown that for a 20 cm long holder surrounded by rings with an arbitrary resistance profile, the temperature uniformity can be improved by adding a few "hot" rings around the cell holder.

Lim, S. D.; Karmalawi, A. M.; Salim, S. G. R.; Soliman, M. A.; Kim, B. H.; Lee, D. H.; Yoo, Y. S.

2014-07-01

168

Optimization of the thermogauge furnace for realizing high temperature fixed points

NASA Astrophysics Data System (ADS)

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.

Wang, T.; Dong, W.; Liu, F.

2013-09-01

169

NASA Astrophysics Data System (ADS)

Fixed-point iteration shows promise for quantitative reconstruction of optical absorption in photoacoustic tomography. However, there are issues that prevent the technique from being practical including: non-uniqueness of scattering and absorption profiles, divergence with over-iteration, and sensitivity to noise. Multiple illumination has been proposed to deal with the first problem, and may help with the second. The issue of noise may be balanced out by increasing the regularization parameter at the expense of the exactness of the reconstruction. In a multiple-illumination setup with a circular geometry where fluence is abundant, using a patterned illumination with a decoding step may provide an alternative which will boost SNR. We present a simple sequence of patterned illuminations based on an S-sequence that serves to improve SNR. While the forward model of the iterative method may be applied directly to the patterned excitations, including the decoding step improves SNR in an individual image by a factor equal to the size of the S-sequence, thus greatly improving convergence for a given value of regularization and SNR. For example, with 15 illuminations, 50-60dB noise levels with S-sequence patterned illuminations gives similar simulated performance to the 70dB case with single-source illuminations. This technique will allow the application of fixed-point iteration techniques in a broader range of SNR conditions without resorting to averaging.

Harrison, Tyler; Shao, Peng; Zemp, Roger

2014-03-01

170

Using fixed point methods, we prove the Hyers-Ulam-Rassias stability and superstability of Jordan homomorphisms (Jordan *-homomorphisms), and Jordan derivations (Jordan *-derivations) on Banach algebras (C*-algebras) for the generalized Jensen-type functional equationrf(x+yr)+rf(x-yr)=2f(x), where r is a fixed positive real number in (1,?).

M. Eshaghi Gordji; A. Najati; A. Ebadian

2011-01-01

171

NASA Astrophysics Data System (ADS)

Ambiguity resolution (AR) for a single receiver has been a popular topic in Global Positioning System (GPS) recently. Ambiguity-resolution methods for precise point positioning (PPP) have been well documented in recent years, demonstrating that it can improve the accuracy of PPP. However, users are often concerned about the reliability of ambiguity-fixed PPP solution in practical applications. If ambiguities are fixed to wrong integers, large errors would be introduced into position estimates. In this paper, we aim to assess the correct fixing rate (CFR), i.e., number of ambiguities correctly fixing to the total number of ambiguities correctly and incorrectly fixing, for PPP user ambiguity resolution on a global scale. A practical procedure is presented to evaluate the CFR of PPP user ambiguity resolution. GPS data of the first 3 days in each month of 2010 from about 390 IGS stations are used for experiments. Firstly, we use GPS data collected from about 320 IGS stations to estimate global single-differenced (SD) wide-lane and narrow-lane satellite uncalibrated phase delays (UPDs). The quality of UPDs is evaluated. We found that wide-lane UPD estimates have a rather small standard deviation (Std) between 0.003 and 0.004 cycles while most of Std of narrow-lane estimates are from 0.01 to 0.02 cycles. Secondly, many experiments have been conducted to investigate the CFR of integer ambiguity resolution we can achieve under different conditions, including reference station density, observation session length and the ionospheric activity. The results show that the CFR of PPP can exceed 98.0 % with only 1 h of observations for most user stations. No obvious correlation between the CFR and the reference station density is found. Therefore, nearly homogeneous CFR can be achieved in PPP AR for global users. At user end, higher CFR could be achieved with longer observations. The average CFR for 30-min, 1-h, 2-h and 4-h observation is 92.3, 98.2, 99.5 and 99.7 %, respectively. In order to get acceptable CFR, 1 h is a recommended minimum observation time. Furthermore, the CFR of PPP can be affected by diurnal variation and geomagnetic latitude variation in the ionosphere. During one day at the hours when rapid ionospheric variations occur or in low geomagnetic latitude regions where equatorial electron density irregularities are produced relatively frequently, a significant degradation of the CFR is demonstrated.

Zhang, Xiaohong; Li, Pan

2013-06-01

172

Using fixed point methods, we prove the generalized Hyers--Ulam--Rassias stability of ternary homomorphisms, and ternary multipliers in ternary Banach algebras for the Jensen--type functional equation

Gordji, M Eshaghi

2009-01-01

173

NASA Astrophysics Data System (ADS)

We derive simplified normal forms for an area-preserving map in a neighbourhood of a degenerate resonant elliptic fixed point. Such fixed points appear in generic families of area-preserving maps. We also derive a simplified normal form for a generic two-parametric family. The normal forms are used to analyse bifurcations of n-periodic orbits. In particular, for n ? 6 we find regions of parameters where the normal form has ‘meandering’ invariant curves.

Gelfreich, Vassili; Gelfreikh, Natalia

2014-07-01

174

Sensitivity of collective action to uncertainty about climate tipping points

NASA Astrophysics Data System (ADS)

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.

Barrett, Scott; Dannenberg, Astrid

2014-01-01

175

Self-validating type C thermocouples to 2300 °C using high temperature fixed points

NASA Astrophysics Data System (ADS)

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.

Pearce, J. V.; Elliott, C. J.; Machin, G.; Ongrai, O.

2013-09-01

176

NASA Astrophysics Data System (ADS)

This paper reports thermal modelling that aims to establish if the measurement method - either by a radiation thermometer or by a thermocouple - significantly influences the measured temperature of the high temperature fixed points Co-C, Pd-C and Ru-C. It is clear that both measurement techniques have specific physical characteristics which may affect the temperature measured during the melting plateau. With the radiation thermometer, the radiation heat transfer is directly influenced by the environment because the back-wall is effectively viewing the cold outside environment. In the case of a thermocouple direct viewing of the outside world is blocked so radiation transport is significantly reduced; however, in the case of the thermocouple there is a different component of heat transfer, namely conduction from the thermowell walls in contact with the thermocouple along the thermocouple stem itself.

Castro, P.; Machin, G.; Pearce, J. V.

2013-09-01

177

NASA Astrophysics Data System (ADS)

Let A be a C?-ternary algebra. A C-bilinear T :A×A?A is called a C?-ternary algebra bi-multiplier, if it satisfies T([abc],d)=[T(a,b)cd], T(a,[bcd])=[abT(c,d)] for all a,b,c,d?A. Also, the mapping T :A×A?A is a called C?-ternary algebra Jordan bimultiplier, if it satisfies T([aaa],a)=[T(a,a)aa], T(a,[aaa])=[aaT(a,a)] for all a ?A. Using the fixed point method, we investigate the generalized Hyers-Ulam-Rassias stability of bimultipliers and Jordan bimultipliers in C?-ternary algebras. The concept of Hyers-Ulam-Rassias stability originated from the Th.M. Rassias' stability theorem that appeared in his paper: [Th. M. Rassias, Proc. Am. Math. Soc. 72, 297 (1978)].

Ebadian, A.; Ghobadipour, N.; Eshaghi Gordji, M.

2010-10-01

178

NASA Technical Reports Server (NTRS)

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.

Shimada, Seiichi; Bock, Yehuda

1992-01-01

179

Point and Fixed Plot Sampling Inventory Estimates at the Savannah River Site, South Carolina.

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.

Parresol, Bernard, R.

2004-02-01

180

Correlation Between Immersion Profile and Measured Value of Fixed-Point Temperature

NASA Astrophysics Data System (ADS)

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.

Shulgat, O. S.; Fuksov, V. M.; Ivanova, A. G.; Gerasimov, S. F.; Pokhodun, A. I.

2014-04-01

181

Analyses of pointing actions of top male competitors in karate at world level

Karate takes a significant place in sport today. Work goal is determination of quantity indicators related to pointing action at sports fights at top-level male karate competitors. Pointing actions were analysed through basic pointing ways (attack, interception and counterattack) and pointing techniques that exist in sports fight and are defined by judging rules. Research is based on analysis of seven

Seied Mohammad Marandi; Vahid Zolaktaf; Mohammad Reza Batavani

2010-01-01

182

Assessment of tungsten/rhenium thermocouples with metal-carbon eutectic fixed points up to 1500°C

NASA Astrophysics Data System (ADS)

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.

Gotoh, M.

2013-09-01

183

Assessment of tungsten/rhenium thermocouples with metal-carbon eutectic fixed points up to 1500°C

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.

Gotoh, M. [National Research Council of Canada 1200 Montreal Road, Ottawa ON. Canada K1A 0R6 (Canada)] [National Research Council of Canada 1200 Montreal Road, Ottawa ON. Canada K1A 0R6 (Canada)

2013-09-11

184

Thermodynamic temperature determinations of Co C, Pd C, Pt C and Ru C eutectic fixed-point cells

NASA Astrophysics Data System (ADS)

Thermodynamic temperatures during the melt and the freeze of Co-C, Pd-C, Pt-C and Ru-C metal-carbon fixed-point cells manufactured by LNE-INM/CNAM, NMIJ and NPL were determined by absolutely calibrated filter radiometers traceable to the PTB cryogenic radiometer and a radiance comparison method using an IKE LP3 radiation thermometer. The measurement uncertainties were below 400 mK at temperatures up to 2250 K. The results are in agreement within the combined uncertainties with a study on relative temperature differences of the same set of fixed-point cells. For the fixed-point cells manufactured by NPL the results are compared with a previous thermodynamic temperature measurement.

Anhalt, K.; Hartmann, J.; Lowe, D.; Machin, G.; Sadli, M.; Yamada, Y.

2006-04-01

185

Above the freezing point of silver (961.78 °C), the International Temperature Scale of 1990 is defined in terms of Planck's radiation law. The scale is maintained and disseminated using a validated and linear pyrometer in conjunction with a blackbody reference source at either the Ag, Au (1064.18 °C) or Cu (1084.62 °C) freezing point. In order to realize the scale

H. C. McEvoy; G. Machin; R. Friedrich; J. Hartmann; J. Hollandt

2003-01-01

186

Realization of the WC-C peritectic fixed point at NIM and NMIJ

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.

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

187

Realization of the WC-C peritectic fixed point at NIM and NMIJ

NASA Astrophysics Data System (ADS)

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 T90 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 T90 values of these cells were measured from 7 Dec. 2011 to 9 Jan. 2012. The results showed that T90 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.

Wang, T.; Sasajima, N.; Yamada, Y.; Bai, C.; Yuan, Z.; Dong, W.; Ara, C.; Lu, X.

2013-09-01

188

The goal of the present paper is to investigate some new stability results by applying the alternative fixed point of generalized\\u000a quadratic functional equation\\u000a \\u000a \\u000a \\u000a \\u000a $$\\\\begin{array}{ll}f\\\\left(\\\\sum\\\\limits_{i=1}^{n}a_ix_i\\\\right)+{\\\\sum\\\\limits_{i=1}^{n-1}}{\\\\sum\\\\limits_{j=i+1}^{n}}\\\\left[f(a_ix_i+a_jx_j)+2f(a_ix_i-a_jx_j)\\\\right]\\\\\\\\ \\\\qquad \\\\quad = (3n-2){\\\\sum\\\\limits_{i=1}^{n}}a^2_{i}f(x_{i})\\\\end{array}$$\\u000a \\u000a \\u000a \\u000a in ?–Banach modules on Banach algebras, where $${a_{1},\\\\dots,a_{n}\\\\in \\\\mathbb{Z}{\\\\setminus}\\\\{0\\\\}}$$ and some $${\\\\ell\\\\in\\\\{1 , 2 ,\\\\dots, n-1\\\\},}$$\\u000a a\\u000a \\u000a ?\\u000a ? ±1 and a\\u000a \\u000a n\\u000a = 1, where n is a positive integer greater

M. Eshaghi. Gordji; H. Khodaei; Th. M. Rassias

189

Recently compressed sensing (CS) has been applied to under-sampling MR image reconstruction for significantly reducing signal acquisition time. To guarantee the accuracy and efficiency of the CS-based MR image reconstruction, it necessitates determining several regularization and algorithm-introduced parameters properly in practical implementations. The regularization parameter is used to control the trade-off between the sparsity of MR image and the fidelity measures of k-space data, and thus has an important effect on the reconstructed image quality. The algorithm-introduced parameters determine the global convergence rate of the algorithm itself. These parameters make CS-based MR image reconstruction a more difficult scheme than traditional Fourier-based method while implemented on a clinical MR scanner. In this paper, we propose a new approach that reveals that the regularization parameter can be taken as a threshold in a fixed-point iterative shrinkage/thresholding algorithm (FPIST) and chosen by employing minimax threshold selection method. No extra parameter is introduced by FPIST. The simulation results on synthetic and real complex-valued MRI data show that the proposed method can adaptively choose the regularization parameter and effectively achieve high reconstruction quality. The proposed method should prove very useful for practical CS-based MRI applications. PMID:24512794

Wu, Geming; Luo, Shuqian

2014-05-01

190

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.

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

191

NASA Astrophysics Data System (ADS)

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.

Castro, P.; Machin, G.; Bloembergen, P.; Lowe, D.; Whittam, A.

2014-07-01

192

Surveying avian species during the breeding season is important to land managers for monitoring population trends and relative abundance. During spring 2003, we estimated species richness and abundance of breeding birds on 60 plots on Fort Riley Military Installation, KS. We used strip-transects and fixed-radius point counts conducted on the same plots but on different days. Our 100-m radius point

RUSSELL D. JAPUNTICH; DONALD P. ALTHOFF; PHILIP S. GIPSON; JEFFREY S. PONTIUS

193

NASA Astrophysics Data System (ADS)

We give some sufficient conditions for the Domínguez-Lorenzo condition in terms of the James constant, the Jordan-von Neumann constant, and the coefficient of weak orthogonality. As a consequence, we obtain fixed point theorems for multivalued nonexpansive mappings.

Kaewkhao, Attapol

2007-09-01

194

The measure for the one loop scattering of one and $N$ bosonic strings is calculated using the Group Theoretic approach to String Theory. The calculation is done for the case when the projective transformation associated with the loop can be parametrized in terms of two finite fixed points and the multiplier.

Leonidas Sandoval Jr

2001-06-02

195

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

Huang, Na

2014-01-01

196

RG fixed points in supergravity duals of 4-d field theory and asymptotically AdS spaces

NASA Astrophysics Data System (ADS)

Recently, it has been conjectured that supergravity solutions with two asymptotically AdS5 regions describe the RG flow of a 4-d field theory from a UV fixed point to an interacting IR fixed point. In this paper we lend support to this conjecture by showing that, in the UV (IR) limit, the two-point function of a minimally coupled scalar field depends only on the UV (IR) region of the metric, asymptotic to AdS5. This result is consistent with the interpretation of the radial coordinate of Anti de Sitter space as an energy scale, and it may provide an analog of the Callan-Symanzik equation for supergravity duals of strongly coupled field theories.

Porrati, M.; Starinets, A.

1999-05-01

197

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.

Sumit Mohinta; T. K. Samanta

2011-04-16

198

The following paper compares a consistent Newton-Raphson and fixed-point iteration based solution strategy for a variational multiscale finite element formulation for incompressible Navier-Stokes. The main contributions of this work include a consistent linearization of the Navier-Stokes equations, which provides an avenue for advanced algorithms that require origins in a consistent method. We also present a comparison between formulations that differ only in their linearization, but maintain all other equivalences. Using the variational multiscale concept, we construct a stabilized formulation (that may be considered an extension of the MINI element to nonlinear Navier-Stokes). We then linearize the problem using fixed-point iteration and by deriving a consistent tangent matrix for the update equation to obtain the solution via Newton-Raphson iterations. We show that the consistent formulation converges in fewer iterations, as expected, for several test problems. We also show that the consistent formulation ...

Turner, D Z; Hjelmstad, K D

2008-01-01

199

On the maximum number of fixed points in automorphisms of prime order of 2(v; k; 1) designs

). Further, for 3 Å¸ k Å¸ 5 and for any prime p j 1 mod k(k \\Gamma 1), we establish necessary and sufficient Å¸ 5 and for any prime p j 1 mod k(k \\Gamma 1), we establish necessary and sufficient conditions on vOn the maximum number of fixed points in automorphisms of prime order of 2Â(v; k; 1) designs D. L

Stinson, Douglas

200

NASA Astrophysics Data System (ADS)

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.

Sadli, Mohamed; Bourson, Frédéric; Diril, Ahmet; Journeau, Christophe; Lowe, Dave; Parga, Clemente

2014-08-01

201

Most computers in the past have been equipped with floating point processing capabilities, allowing an easy and brute-force solution for the machine computation errors, not requiring any specific tailoring of the computation in nearly hundred percent of situations. However, the computation needed for the adaptive optics real-time control in 30-50 meter telescopes is big enough to cause trouble to conventional

Yolanda Martín-Hernando; Luis F. Rodríguez-Ramos; Marcos R. Garcia-Talavera

2008-01-01

202

APPROACHING THE TIPPING POINT CLIMATE RISKS, FAITH AND POLITICAL ACTION

Scientific and media reports have become enthralled by the apocalyptic overtones of climatic 'tipping points'. These are thresholds after which a relatively small shift in the Earth system (e.g. melting Arctic perma-frost) has a big, sudden impact on the overall system. Related is the prospect of runaway or 'irreversible' global warming. But it has also revived an interest in its

Stefan Skrimshire

2008-01-01

203

The stability of a quadratic type functional equation with the fixed point alternative

In this paper, we achieve the general solution and the generalized Hyers-Ulam-Rassias stability for the quadratic type functional equation &f(x+y+2cz)+f(x+y-2cz)+c^2f(2x)+c^2f(2y) &=2[f(x+y)+c^2f(x+z)+c^2f(x-z)+c^2f(y+z)+c^2f(y-z)] {2.6 cm} for fixed integers $c$ with $c\

Gordji, M Eshaghi

2008-01-01

204

Fixed points and functional equations connected with derivations on Banach algebras

Let 1?m?4 be a fixed integer and let f:X?Y be a mapping with X, Y two vector spaces. The functional equation (1.1) is said to be additive if m=1, quadratic if m=2, cubic if m=3 and quartic if m=4, respectively. For convenience, a solution of (1.1) will be called an m-mapping. Let \\u000a \\u000a , \\u000a \\u000a be two algebras. An m-mapping \\u000a \\u000a will be

Z. Alizadeh; M. Eshaghi Gordji; H. Khodaei

205

The stability of a quadratic type functional equation with the fixed point alternative

In this paper, we achieve the general solution and the generalized Hyers-Ulam-Rassias stability for the quadratic type functional equation &f(x+y+2cz)+f(x+y-2cz)+c^2f(2x)+c^2f(2y) &=2[f(x+y)+c^2f(x+z)+c^2f(x-z)+c^2f(y+z)+c^2f(y-z)] {2.6 cm} for fixed integers $c$ with $c\\\

M. Eshaghi Gordji; H. Khodaei

2008-01-01

206

General form of fixed point indices of an iterated C map and infiniteness of minimal periods

Let f be a smooth self-map of a compact manifold and be a family of compact subsets of periodic points of f. Under some natural condition on the family we find the form of the sequence of indices of iterations , which generalizes the classical theorem of Chow, Mallet-Paret and Yorke. We apply this knowledge to study the structure of

Grzegorz Graff; Piotr Nowak-Przygodzki

2008-01-01

207

Control of transient chaos in tent maps near crisis.??I.??Fixed point targeting

Combinatorial techniques are applied to the symbolic dynamics representing tran- sient chaotic behaviour in tent maps in order to solve the problem of OGY control to the non-trivial xed point occurring in such maps. This approach allows 'pre-image overlap' to be treated exactly. Closed forms for both the probability of control being achieved and the average number of iterations to

D. K. Arrowsmith

2000-01-01

208

NASA Astrophysics Data System (ADS)

Of the various types of passive engine mounts, hydraulic engine mounts (HEMs) have the best noise, vibration and harshness (NVH) performance. Based on the third type HEM, which has an inertia track, decoupler and disturbing plate, the influences of the three hydraulic mechanisms, the length of the inertia track or the diameter of the orifice on the dynamic properties were studied experimentally. The working principles of the hydraulic mechanisms and the relationship between the dynamic properties of the three type HEMs were revealed clearly. It was discovered that the frequency-variant dynamic properties of HEMs with an inertia track or an orifice have excitation amplitude-invariant fixed points. Based on the theory of engineering hydromechanics, a nonlinear lumped parameter model (LPM) for an HEM with an inertia track was established, and an analytical solution was obtained in which the fixed point of dynamic stiffness in-phase was discovered theoretically. According to the phenomena of fixed points and the constant value of dynamic stiffness in-phase at higher bands, a new parameter identification method (PIM) was presented, which is clear in theory and is time and cost savings, the identified results are reliable. The results show that the fluid flow through an orifice can be replaced by a fluid flow through an equivalent length of inertia track. After this, a PIM for the fluid-flow local loss factor was developed. The identified results and the numerical simulations show that the reason the disturbing plate can keep the dynamic stiffness lower at higher bands is that the disturbing plate can sharply increase the quadratic fluid damping due to larger local loss, and then the resonance of the fluid flow through the decoupler channel or orifice is greatly attenuated. This conclusion is a useful attempt to explain the working principle of the disturbing plate.

Fan, Ranglin; Lu, Zhenhua

2007-09-01

209

This Corrective Action Decision Document (CADD) identifies and rationalizes the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office's selection of a recommended corrective action alternative appropriate to facilitate the closure of Corrective Action Unit (CAU) 516: Septic Systems and Discharge Points, Nevada Test Site (NTS), Nevada, under the Federal Facility Agreement and Consent Order. Located in Areas 3, 6, and 22 on the NTS, CAU 516 includes six Corrective Action Sites (CASs) consisting of two septic systems, a sump and piping, a clean-out box and piping, dry wells, and a vehicle decontamination area. Corrective action investigation activities were performed from July 22 through August 14, 2003, with supplemental sampling conducted in late 2003 and early 2004. The potential exposure pathways for any contaminants of concern (COCs) identified during the development of the DQOs at CAU 516 gave rise to the following objectives: (1) prevent or mitigate exposure to media containing COCs at concentrations exceeding PALs as defined in the corrective action investigation plan; and (2) prevent the spread of COCs beyond each CAS. The following alternatives have been developed for consideration at CAU 516: Alternative 1 - No Further Action; Alternative 2 - Clean Closure; and Alternative 3 - Closure in Place with Administrative Controls. Alternative 1, No Further Action, is the preferred corrective action for two CASs (06-51-02 and 22-19-04). Alternative 2, Clean Closure, is the preferred corrective action for four CASs (03-59-01, 03-59-02, 06-51-01, and 06-51-03). The selected alternatives were judged to meet all requirements for the technical components evaluated, as well as meeting all applicable state and federal regulations for closure of the site and will further eliminate the contaminated media at CAU 516.

U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office

2004-04-28

210

NASA Astrophysics Data System (ADS)

Fast fixed-point independent vector analysis (FastIVA) is an improved independent vector analysis (IVA) method, which can achieve faster and better separation performance than original IVA. As an example IVA method, it is designed to solve the permutation problem in frequency domain independent component analysis by retaining the higher order statistical dependency between frequencies during learning. However, the performance of all IVA methods is limited due to the dimensionality of the parameter space commonly encountered in practical frequency-domain source separation problems and the spherical symmetry assumed with the source model. In this article, a particular permutation problem encountered in using the FastIVA algorithm is highlighted, namely the block permutation problem. Therefore a new audio video based fast fixed-point independent vector analysis algorithm is proposed, which uses video information to provide a smart initialization for the optimization problem. The method cannot only avoid the ill convergence resulting from the block permutation problem but also improve the separation performance even in noisy and high reverberant environments. Different multisource datasets including the real audio video corpus AV16.3 are used to verify the proposed method. For the evaluation of the separation performance on real room recordings, a new pitch based evaluation criterion is also proposed.

Liang, Yanfeng; Naqvi, Syed Mohsen; Chambers, Jonathon A.

2012-12-01

211

We introduce the concept of fuzzy Ciric-Matkowski contractive mappings as a generalization of fuzzy Meir-Keeler type contractions. We also introduce a class $\\Psi_1$ of gauge functions $\\psi:(0,1]\\to(0,1]$ in the sense that, for any $r\\in(0,1)$, there exists $\\rho\\in(r,1)$ such that $1-r> \\tau >1-\\rho$ implies $\\psi(\\tau)\\geq 1-r$. We show that fuzzy $\\psi$-contractive mappings ($\\psi\\in\\Psi_1$) are fuzzy Ciric-Matkowski contractive mappings. Then, we present a characterization of $M$-Cauchy sequences in fuzzy metric spaces. This characterization is used to establish new fuzzy fixed point theorems. Our results include those of Mihet (Fuzzy $\\psi$-contractive mappings in non-Archimedean fuzzy metric spaces, Fuzzy Sets Syst. 159(2008) 739--744.), Wardowski (Fuzzy contractive mappings and fixed points in fuzzy metric spaces, Fuzzy Sets Syst. 222(2013) 108--114) and others. Examples are given to support the results.

Mortaza Abtahi

2014-10-20

212

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).

DOE /NV

1999-06-19

213

A comparison between the Newton-Raphson method and the fixed-point technique in hysteretic magnetic field problems is presented. Four different approaches are studied and contrast between them in terms of the convergence rate and computation time consumption is highlighted. The Newton-Raphson-based approaches are found better than the iteration schemes associated with the fixed-point technique for a model problem

Jlilius Saitz

1999-01-01

214

A Phase-Field Solidification Model of Almost Pure ITS-90 Fixed Points

NASA Astrophysics Data System (ADS)

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 231.928° C). 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 {<}1 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 100 {\\upmu } K to 200 {\\upmu } K 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.

Large, M. J.; Pearce, J. V.

2014-08-01

215

A Phase-Field Solidification Model of Almost Pure ITS-90 Fixed Points

NASA Astrophysics Data System (ADS)

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.

Large, M. J.; Pearce, J. V.

2014-07-01

216

Metformine : le point sur les mcanismes d'action Metformin: new insights on the mechanisms of action

1 Metformine : le point sur les mÃ©canismes d'action Metformin: new insights on the mechanisms-SalpÃªtriÃ¨re (AP-HP), UniversitÃ© Pierre et Marie Curie-Paris 6, Paris, France Mots-clÃ©s : Metformine Â DiabÃ¨te de type 2 Â AMPK Â MÃ©tabolisme Ã©nergÃ©tique Keywords : Metformin Â Type 2 diabetes Â AMPK Â Energy

Paris-Sud XI, UniversitÃ© de

217

The molecular basis of a neuroendocrine fixed action pattern: egg laying in Aplysia.

We describe a gene family that encodes the proteins controlling the egg-laying behavior of Aplysia. The family evolved by duplication and divergence from a common ancestral gene. The ELH gene family is expressed in the atrial gland, in the bag cells, and in a small network of neurons in the central ganglia. The bag cells and the atrial gland express distinct members of the family that encode different precursor proteins. These contain one or more biologically active peptides that can be released by proteolytic cleavage. The bag cell precursor releases several peptides that have multiple sites of action and may generate different components of the egg-laying behavior. Coordination of the full stereotyped behavior is achieved by simultaneous release of these peptides from the bag cell processes. PMID:6327167

Mahon, A C; Scheller, R H

1983-01-01

218

NASA Astrophysics Data System (ADS)

We use scaling and renormalization-group techniques to analyze the leading nonanalyticities in a Fermi liquid. We show that a physically motivated scaling hypothesis reproduces the results known from perturbation theory for the density of states, the density-of-states fluctuations, the specific heat, the spin susceptibility, and the nematic magnetic susceptibility. We also discuss the absence of nonanalytic terms in the density susceptibility. We then use a recent effective field theory for clean electron systems to derive the scaling hypothesis by means of renormalization-group techniques. This shows that the exponents (although not the prefactors) of the nonanalyticities that were previously derived by means of perturbative techniques are indeed exact, and can be understood as the leading corrections to scaling at the stable Fermi-liquid fixed point.

Belitz, D.; Kirkpatrick, T. R.

2014-01-01

219

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.

Selbig, William R.; Bannerman, Roger T.

2011-01-01

220

In accident investigation, the ideal is often to follow the principle “what-you-find-is-what-you-fix”, an ideal reflecting that the investigation should be a rational process of first identifying causes, and then implement remedial actions to fix them. Previous research has however identified cognitive and political biases leading away from this ideal. Somewhat surprisingly, however, the same factors that often are highlighted in

Jonas Lundberg; Carl Rollenhagen; Erik Hollnagel

2010-01-01

221

"Raising the Point!": An Artistic Approach in Supporting a Community's Call to Action

ERIC Educational Resources Information Center

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…

Mendez, Jason

2013-01-01

222

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

Steinberg, Richard N.

223

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.

NONE

1998-06-01

224

Asymptotically free four-Fermi theory in 4 dimensions at the z=3 Lifshitz-like fixed point

We show that a Nambu-Jona-Lasinio type four-fermion coupling at the z=3 Lifshitz-like fixed point in 3+1 dimensions is asymptotically free and generates a mass scale dynamically. This result is nonperturbative in the limit of a large number of fermion species. The theory is ultraviolet complete and at low energies exhibits Lorentz invariance as an emergent spacetime symmetry. Many of our results generalize to z=d in odd d spatial dimensions; z=d=1 corresponds to the Gross-Neveu model. The above mechanism of mass generation has potential applications to the fermion mass problem and to dynamical electroweak symmetry breaking. We present a scenario in which a composite Higgs field arises from a condensate of these fermions, which then couples to quarks and leptons of the standard model. Such a scenario could eliminate the need for the Higgs potential and the associated hierarchy problem. We also show that the axial anomaly formula at z=3 coincides with the usual one in the relativistic domain.

Dhar, Avinash; Mandal, Gautam [Department of Theoretical Physics, Tata Institute of Fundamental Research, Mumbai 400 005 (India); Wadia, Spenta R. [Department of Theoretical Physics, Tata Institute of Fundamental Research, Mumbai 400 005 (India); International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Mumbai 400 005 (India)

2009-11-15

225

Corrective Action Unit (CAU) 556, Dry Wells and Surface Release Points, is located in Areas 6 and 25 of the Nevada Test Site, 65 miles northwest of Las Vegas, Nevada. Corrective Action Unit 556 is comprised of four corrective action sites (CASs) listed below: •06-20-04, National Cementers Dry Well •06-99-09, Birdwell Test Hole •25-60-03, E-MAD Stormwater Discharge and Piping •25-64-01, Vehicle Washdown and Drainage Pit These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives. Additional information will be obtained by conducting a corrective action investigation before evaluating corrective action alternatives and selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible evaluation of viable corrective action alternatives that will be presented in the Corrective Action Decision Document.

Grant Evenson

2007-02-01

226

Acknowledgments We appreciate the helpful comments,of Mark Zachry and Charlotte Thralls on an earlier draft of this chapter. This research was supported in part by a grant from the National Science Foundation (award #ITR-0085725). ii The PowerPoint Presentation and Its Corollaries: How Genres Shape Communicative Action in Organizations Abstract In this chapter, we examine how and with what consequences the

JoAnne Yates; Wanda Orlikowski

227

Closure Report for Corrective Action Unit 516: Septic Systems and Discharge Points

Corrective Action Unit (CAU) 516 is located in Areas 3, 6, and 22 of the Nevada Test Site. CAU 516 is listed in the Federal Facility Agreement and Consent Order of 1996 as Septic Systems and Discharge Points, and is comprised of six Corrective Action Sites (CASs): {sm_bullet} CAS 03-59-01, Bldg 3C-36 Septic System {sm_bullet} CAS 03-59-02, Bldg 3C-45 Septic System {sm_bullet} CAS 06-51-01, Sump and Piping {sm_bullet} CAS 06-51-02, Clay Pipe and Debris {sm_bullet} CAS 06-51-03, Clean Out Box and Piping {sm_bullet} CAS 22-19-04, Vehicle Decontamination Area The Nevada Division of Environmental Protection (NDEP)-approved corrective action alternative for CASs 06-51-02 and 22-19-04 is no further action. The NDEP-approved corrective action alternative for CASs 03-59-01, 03-59-02, 06-51-01, and 06-51-03 is clean closure. Closure activities included removing and disposing of total petroleum hydrocarbon (TPH)-impacted septic tank contents, septic tanks, distribution/clean out boxes, and piping. CAU 516 was closed in accordance with the NDEP-approved CAU 516 Corrective Action Plan (CAP). The closure activities specified in the CAP were based on the recommendations presented in the CAU 516 Corrective Action Decision Document (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, 2004). This Closure Report documents CAU 516 closure activities. During closure activities, approximately 186 tons of hydrocarbon waste in the form of TPH-impacted soil and debris, as well as 89 tons of construction debris, were generated and managed and disposed of appropriately. Waste minimization techniques, such as field screening of soil samples and the utilization of laboratory analysis to characterize and classify waste streams, were employed during the performance of closure work.

NSTec Environmental Restoration

2007-02-01

228

NASA Astrophysics Data System (ADS)

In this paper, by means of the Avery-Peterson fixed point theorem, we establish the existence result of at least triple positive solutions of four-point boundary value problem of nonlinear differential equation with Caputo's fractional order derivative. An example illustrating our main result is given. Our results complements previous work in the area of boundary value problems of nonlinear fractional differential equations.

Liu, Yang

2012-12-01

229

ERIC Educational Resources Information Center

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…

Bellver-Cebreros, Consuelo; Rodriguez-Danta, Marcelo

2009-01-01

230

We introduce an iterative process for finding an element of a common fixed point of a finite family of Bregman weak relatively nonexpansive mappings. Our theorems improve and unify most of the results that have been proved for this important class of nonlinear operators. PMID:24757423

2014-01-01

231

NASA Astrophysics Data System (ADS)

Recently, Agarwal, Cho, Li and Huang [R.P. Agarwal, Y.J. Cho, J. Li, N.J. Huang, Stability of iterative procedures with errors approximating common fixed points for a couple of quasi-contractive mappings in q-uniformly smooth Banach spaces, J. Math. Anal. Appl. 272 (2002) 435-447] introduced the new iterative procedures with errors for approximating the common fixed point of a couple of quasi-contractive mappings and showed the stability of these iterative procedures with errors in Banach spaces. In this paper, we introduce a new concept of a couple of q-contractive-like mappings (q>1) in a Banach space and apply these iterative procedures with errors for approximating the common fixed point of the couple of q-contractive-like mappings. The results established in this paper improve, extend and unify the corresponding ones of Agarwal, Cho, Li and Huang [R.P. Agarwal, Y.J. Cho, J. Li, N.J. Huang, Stability of iterative procedures with errors approximating common fixed points for a couple of quasi-contractive mappings in q-uniformly smooth Banach spaces, J. Math. Anal. Appl. 272 (2002) 435-447], Chidume [C.E. Chidume, Approximation of fixed points of quasi-contractive mappings in Lp spaces, Indian J. Pure Appl. Math. 22 (1991) 273-386], Chidume and Osilike [C.E. Chidume, M.O. Osilike, Fixed points iterations for quasi-contractive maps in uniformly smooth Banach spaces, Bull. Korean Math. Soc. 30 (1993) 201-212], Liu [Q.H. Liu, On Naimpally and Singh's open questions, J. Math. Anal. Appl. 124 (1987) 157-164; Q.H. Liu, A convergence theorem of the sequence of Ishikawa iterates for quasi-contractive mappings, J. Math. Anal. Appl. 146 (1990) 301-305], Osilike [M.O. Osilike, A stable iteration procedure for quasi-contractive maps, Indian J. Pure Appl. Math. 27 (1996) 25-34; M.O. Osilike, Stability of the Ishikawa iteration method for quasi-contractive maps, Indian J. Pure Appl. Math. 28 (1997) 1251-1265] and many others in the literature.

Zeng, Lu-Chuan; Yao, Jen-Chih

2006-09-01

232

Pointing losses in single-axis and fixed-mount earth-station antennas due to satellite movement

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

L. M. Buchsbaum

1986-01-01

233

We consider the Schr\\"odinger equation for a relativistic point particle in an external 1-dimensional $\\delta$-function potential. Using dimensional regularization, we investigate both bound and scattering states, and we obtain results that are consistent with the abstract mathematical theory of self-adjoint extensions of the pseudo-differential operator $H = \\sqrt{p^2 + m^2}$. Interestingly, this relatively simple system is asymptotically free. In the massless limit, it undergoes dimensional transmutation and it possesses an infra-red conformal fixed point. Thus it can be used to illustrate non-trivial concepts of quantum field theory in the simpler framework of relativistic quantum mechanics.

M. H. Al-Hashimi; A. M. Shalaby; U. -J. Wiese

2014-04-11

234

NASA Astrophysics Data System (ADS)

The National Institute of Standards and Technology (NIST) has initiated a project on novel high-temperature fixed-points by use of metal (carbide)-carbon eutectics to lower uncertainties in thermodynamic temperature measurement. As the first stage of the NIST eutectic project, a comparison of Co-C, Pt-C and Re-C eutectic fixed-point cells was conducted between the NIST and the National Metrology Institute of Japan (NMIJ) at the NIST to verify the quality of the NIST eutectic cells in addition to checking for possible furnace and radiation thermometer effects on the eutectic fixed-point realizations. In the comparison, two high-temperature furnaces, two radiation thermometers and one gold-point blackbody were used. A Nagano M furnace and a Linear Pyrometer 3 radiation thermometer were transferred from NMIJ and were used in conjunction with a Thermo Gauge furnace and an Absolute Pyrometer 1 radiation thermometer of NIST to check the dependence on the measurement equipment. The results showed that Co-C cells agreed to 73 mK. The melting temperature of the NIST Pt-C cell was approximately 270 mK lower than that of the NMIJ cell, with a comparison uncertainty of roughly 110 mK (k = 2), due to the poor purity of Pt powder. Although the Re-C comparison showed instability of the comparison system, they agreed within 100 mK. Though further improvement is necessary for the Pt-C cell, such as the use of higher purity Pt, the filling and measuring technique has been established at the NIST.

Sasajima, N.; Yoon, H. W.; Gibson, C. E.; Khromchenko, V.; Sakuma, F.; Yamada, Y.

2006-04-01

235

NASA Astrophysics Data System (ADS)