A General Nonlinear Optimization Algorithm for Lower Bound Limit Analysis
DEFF Research Database (Denmark)
Krabbenhøft, Kristian; Damkilde, Lars
2003-01-01
finite element discretization or yield criterion is required. As with interior point methods for linear programming the number of iterations is affected only little by the problem size. Some practical implementation issues are discussed with reference to the special structure of the common lower bound......The non-linear programming problem associated with the discrete lower bound limit analysis problem is treated by means of an algorithm where the need to linearize the yield criteria is avoided. The algorithm is an interior point method and is completely general in the sense that no particular...... load optimization problem, and finally the efficiency and accuracy of the method is demonstrated by means of examples of plate and slab structures obeying different non-linear yield criteria....
A LOWER BOUND LIMIT ANALYSIS OF DUCTILE COMPOSITE MATERIALS
Institute of Scientific and Technical Information of China (English)
Zhang Hongtao; Liu Yinghua; Xu Bingye
2005-01-01
The plastic load-bearing capacity of ductile composites such as metal matrix composites is studied with an insight into the microstructures. The macroscopic strength of a composite is obtained by combining the homogenization theory with static limit analysis, where the temperature parameter method is used to construct the self-equilibrium stress field. An interface failure model is proposed to account for the effects of the interface on the failure of composites.The static limit analysis with the finite-element method is then formulated as a constrained nonlinear programming problem, which is solved by the Sequential Quadratic Programming (SQP)method. Finally, the macroscopic transverse strength of perforated materials, the macroscopic transverse and off-axis strength of fiber-reinforced composites are obtained through numerical calculation. The computational results are in good agreement with the experimental data.
Lower Bound Limit Analysis Of Slabs With Nonlinear Yield Criteria
DEFF Research Database (Denmark)
Krabbenhøft, Kristian; Damkilde, Lars
2002-01-01
A finite element formulation of the limit analysis of perfectly plastic slabs is given. An element with linear moment fields for which equilibrium is satisfied exactly is used in connection with an optimization algorithm taking into account the full nonlinearity of the yield criteria. Both load and...... material optimization problems are formulated and by means of the duality theory of linear programming the displacements are extracted from the dual variables. Numerical examples demonstrating the capabilities of the method and the effects of using a more refined representation of the yield criteria are...
DEFF Research Database (Denmark)
Frier, Christian; Damkilde, Lars
A method of conducting lower bound Limit State analysis is to apply the interior-point method. The aim of the paper is to refine the method by reducing the number of optimization variables considerably by eliminating the equilibrium equations a priori. Another new idea is to adapt a spatially...
A SOLUTION PROCEDURE FOR LOWER BOUND LIMIT AND SHAKEDOWN ANALYSIS BY SGBEM
Institute of Scientific and Technical Information of China (English)
Zhang Xiaofeng; Liu Yinghua; Cen Zhangzhi
2001-01-01
The symmetric Galerkin boundary element method (SGBEM) instead of the finite element method is used to perform lower bound limit and shakedown analysis of structures. The self-equilibrium stress fields are constructed by a linear combination of several basic self-equilibrium stress fields with parameters to be determined. These basic self-equilibrium stress fields are expressed as elastic responses of the body to imposed permanent strains and obtained through elastic-plastic incremental analysis. The complex method is used to solve nonlinear programming and determine the maximal load amplifier. The limit analysis is treated as a special case of shakedown analysis in which only the proportional loading is considered. The numerical results show that SGBEM is effcient and accurate for solving limit and shakedown analysis problems.
Upper and lower bounds in limit analysis: adaptive meshing strategies and discontinuous loading
Muñoz Romero, José; Bonet Carbonell, Javier; Huerta, Antonio; Peraire Guitart, Jaume
2008-01-01
This is the pre-peer reviewed version of the following article: Muñoz, José J. [et al.]. Upper and lower bounds in limit analysis: adaptive meshing strategies and discontinuous loading. "International journal for numerical methods in engineering", Agost 2008, vol. 77, núm. 4, p. 471-501., which has been published in final form at http://www3.interscience.wiley.com/journal/121370765/abstract Peer Reviewed
Upper-bound limit analysis based on the natural element method
Institute of Scientific and Technical Information of China (English)
Shu-Tao Zhou; Ying-Hua Liu
2012-01-01
The natural element method (NEM) is a newlydeveloped numerical method based on Voronoi diagram and Delaunay triangulation of scattered points,which adopts natural neighbour interpolation to construct trial functions in the framework of Galerkin method.Owing to its distinctive advantages,the NEM is used widely in many problems of computational mechanics.Utilizing the NEM,this paper deals with numerical limit analysis of structures made up of perfectly rigid-plastic material.According to kinematic theorem of plastic limit analysis,a mathematical programming natural element formulation is established for determining the upper bound multiplier of plane problems,and a direct iteration algorithm is proposed accordingly to solve it.In this algorithm,the plastic incompressibility condition is handled by two different treatments,and the nonlinearity and nonsmoothness of the goal function are overcome by distinguishing the rigid zones from the plastic zones at each iteration.The procedure implementation of iterative process is quite simple and effective because each iteration is equivalent to solving an associated elastic problem.The obtained limit load multiplier is proved to monotonically converge to the upper bound of true solution.Several benchmark examples are investigated to validate the significant performance of the NEM in the application field of limit analysis.
Upper-bound limit analysis based on the natural element method
Zhou, Shu-Tao; Liu, Ying-Hua
2012-10-01
The natural element method (NEM) is a newly-developed numerical method based on Voronoi diagram and Delaunay triangulation of scattered points, which adopts natural neighbour interpolation to construct trial functions in the framework of Galerkin method. Owing to its distinctive advantages, the NEM is used widely in many problems of computational mechanics. Utilizing the NEM, this paper deals with numerical limit analysis of structures made up of perfectly rigid-plastic material. According to kinematic theorem of plastic limit analysis, a mathematical programming natural element formulation is established for determining the upper bound multiplier of plane problems, and a direct iteration algorithm is proposed accordingly to solve it. In this algorithm, the plastic incompressibility condition is handled by two different treatments, and the nonlinearity and nonsmoothness of the goal function are overcome by distinguishing the rigid zones from the plastic zones at each iteration. The procedure implementation of iterative process is quite simple and effective because each iteration is equivalent to solving an associated elastic problem. The obtained limit load multiplier is proved to monotonically converge to the upper bound of true solution. Several benchmark examples are investigated to validate the significant performance of the NEM in the application field of limit analysis.
A general non-linear optimization algorithm for lower bound limit analysis
DEFF Research Database (Denmark)
Krabbenhøft, Kristian; Damkilde, Lars
2003-01-01
The non-linear programming problem associated with the discrete lower bound limit analysis problem is treated by means of an algorithm where the need to linearize the yield criteria is avoided. The algorithm is an interior point method and is completely general in the sense that no particular...... load optimization problem. and finally the efficiency and accuracy of the method is demonstrated by means of examples of plate and slab structures obeying different non-linear yield criteria. Copyright (C) 2002 John Wiley Sons. Ltd....... finite element discretization or yield criterion is required. As with interior point methods for linear programming the number of iterations is affected only little by the problem size. Some practical implementation issues are discussed with reference to the special structure of the common lower bound...
An Efficient Implementation of Non-Linear Limit State Analysis Based on Lower-Bound Solutions
DEFF Research Database (Denmark)
Damkilde, Lars; Schmidt, Lotte Juhl
2005-01-01
Limit State analysis has been used in design for decades e.g. the yield line theory for concrete slabs or slip line solutions in geotechnics. In engineering practice manual methods have been dominating but in recent years the interest in numerical methods has been increasing. In this respect it i...... mandatory to formulate the methods using the well-known finite element concept in order to interface with other types of analysis....
Redshift-space limits of bound structures
D"unner, R; Meza, A; Araya, P A; Quintana, H; D\\"unner, Rolando; Reisenegger, Andreas; Meza, Andr\\'es; Araya, Pablo A.; Quintana, Hern\\'an
2006-01-01
An exponentially expanding Universe, possibly governed by a cosmological constant, forces gravitationally bound structures to become more and more isolated, eventually becoming causally disconnected from each other and forming so-called "island universes". This new scenario reformulates the question about which will be the largest structures that will remain gravitationally bound, together with requiring a systematic tool that can be used to recognize the limits and mass of these structures from observational data, namely redshift surveys of galaxies. Here we present a method, based on the spherical collapse model and N-body simulations, by which we can estimate the limits of bound structures as observed in redshift space. The method is based on a theoretical criterion presented in a previous paper that determines the mean density contrast that a spherical shell must have in order to be marginally bound to the massive structure within it. Understanding the kinematics of the system, we translated the real-spac...
DEFF Research Database (Denmark)
Damkilde, Lars
2007-01-01
Limit State analysis has a long history and many prominent researchers have contributed. The theoretical foundation is based on the upper- and lower-bound theorems which give a very comprehensive and elegant formulation on complicated physical problems. In the pre-computer age Limit State analysis...
Tensor Squeezed Limits and the Higuchi Bound
Bordin, Lorenzo; Mirbabayi, Mehrdad; Noreña, Jorge
2016-01-01
We point out that tensor consistency relations-i.e. the behavior of primordial correlation functions in the limit a tensor mode has a small momentum-are more universal than scalar consistency relations. They hold in the presence of multiple scalar fields and as long as anisotropies are diluted exponentially fast. When de Sitter isometries are approximately respected during inflation this is guaranteed by the Higuchi bound, which forbids the existence of light particles with spin: De Sitter space can support scalar hair but no curly hair. We discuss two indirect ways to look for the violation of tensor con- sistency relations in observations, as a signature of models in which inflation is not a strong isotropic attractor, such as solid inflation: (a) Graviton exchange contribution to the scalar four-point function; (b) Quadrupolar anisotropy of the scalar power spectrum due to super-horizon tensor modes. This anisotropy has a well-defined statistics which can be distinguished from cases in which the background...
Bounded sets in fast complete inductive limits
Directory of Open Access Journals (Sweden)
Carlos Bosch
1984-09-01
Full Text Available Let E1Ã¢ÂŠÂ‚E2Ã¢ÂŠÂ‚Ã¢Â€Â¦ be a sequence of locally convex spaces with all identity maps: EnÃ¢Â†Â’En+1 continuous and E=indlimÃ¢Â€Â‰En fast complete. Then each set bounded in E is also bounded in some En iff for any Banach disk B bounded in E and nÃ¢ÂˆÂˆN, the closure of BÃ¢Â‹Â‚En in B is bounded in some Em. This holds, in particular, if all spaces En are webbed.
Supermassive black holes may be limited by the Holographic Bound
Custodio, P S; Custodio, Paulo Sergio
2003-01-01
Supermassive Black Holes are the most entropic objects found in the universe. The Holographic Bound (HB) to the entropy is used to constrain their formation time with initial masses $\\sim{10}^{6-8}M_{\\odot}$, as inferred from observations. We find that the entropy considerations are more limiting than causality for this "direct" formation. Later we analyze the possibility of SMBHs growing from seed black holes. The growth of the initial mass is studied in the case of accretion of pure radiation and quintessence fields, and we find that there is a class of models that may allow this metamorphosis. Our analysis generalizes recent work for some models of quintessence capable of producing a substantial growth in a short time, while simultaneously obeying the causal and Holographic Bound limits.
Pastor, F.; Anoukou, K.; Pastor, J.; Kondo, D.
2016-06-01
This second part of the two-part study is devoted to the numerical Limit Analysis of a hollow sphere model with a Mohr-Coulomb matrix and its use for the assessment of theoretical results. Brief background and fundamental of the static and kinematic approaches in the context of numerical limit analysis are first recalled. We then present the hollow sphere model, together with its axisymmetric FEM discretization and its mechanical position. A conic programming adaptation of a previous iterative static approach, based on a piecewise linearization (PWL) of the plasticity criterion, was first realized. Unfortunately, the resulting code, no more than the PWL one, did not allow sufficiently refined meshes for loss of convergence of the conic optimizer. This problem was solved by using the projection algorithm of Ben Tal and Nemriovski (BTN) and the (interior point) linear programming code XA. For the kinematic approach, a first conic adaptation appeared also inefficient. Then, an original mixed (but fully kinematic) approach dedicated to the general Mohr-Coulomb axisymmetric problem was elaborated. The final conic mixed code appears much more robust than the classic one when using the conic code MOSEK, allowing us to take into account refined numerical meshes. After a fine validation in the case of spherical cavities and isotropic loadings (for which the exact solution is known) and comparison to previous (partial) results, numerical lower and upper bounds (a posteriori verified) of the macroscopic strength are provided. These bounds are used to assess and validate the theoretical results of the companion (part I) paper. Effects of the friction angle as well as that of the porosity are illustrated.
Limit Shapes and Fluctuations of Bounded Random Partitions
DEFF Research Database (Denmark)
Beltoft, Dan
Young diagrams confined to a rectangle. When the rectangle grows, and diagrams are rescaled, the probability measure degenerates to a delta measure on a continuous curve, the limit shape. In the intermediate scaling, the fluctuations around the limit shape turn out to be governed by an Ornstein......-Uhlenbeck process. Similar behaviour occurs in the related models bounded only on one side or not at all, which were studied by Vershik and others....
Automatic analysis of distance bounding protocols
Malladi, Sreekanth; Kothapalli, Kishore
2010-01-01
Distance bounding protocols are used by nodes in wireless networks to calculate upper bounds on their distances to other nodes. However, dishonest nodes in the network can turn the calculations both illegitimate and inaccurate when they participate in protocol executions. It is important to analyze protocols for the possibility of such violations. Past efforts to analyze distance bounding protocols have only been manual. However, automated approaches are important since they are quite likely to find flaws that manual approaches cannot, as witnessed in literature for analysis pertaining to key establishment protocols. In this paper, we use the constraint solver tool to automatically analyze distance bounding protocols. We first formulate a new trace property called Secure Distance Bounding (SDB) that protocol executions must satisfy. We then classify the scenarios in which these protocols can operate considering the (dis)honesty of nodes and location of the attacker in the network. Finally, we extend the const...
Lower bound limit load of a circumferentially cracked pipe under combined mechanical loading
International Nuclear Information System (INIS)
In a study on extension of the reference stress method, for J simplified assessment, to a three dimensional (3D) configuration under combined loading, lower bound limit analysis has been developed by J. Desquines. In the present paper the limit load for cracked pipe, with a 3D circumferential flaw, under pressure, tension and bending is detailed. The limit load is explicitly defined as a yield surface is the 3D space loading. A simple algorithm is proposed to solve the non linear problem associated to the reference stress calculation. Moreover, the lower bound solution is compared with elastic compensation method (ECM) results computed on a 3D finite element mesh of the cracked pipe. The lower bound yield surface underestimates the numerical limit loads with a discrepancy lower than 20%. (orig.)
An Improved Lower Bound Limit State Optimisation Algorithm
DEFF Research Database (Denmark)
Frier, Christian; Damkilde, Lars
2010-01-01
Limit State analysis has been used in engineering practice for many years e.g. the yield-line method for concrete slabs and slip-line solutions in geotechnics. In the recent years there has been an increased interest in numerical Limit State analysis, and today algorithms take into account the non...
An Improved Lower Bound Limit State Optimisation Algorithm
DEFF Research Database (Denmark)
Frier, Christian; Damkilde, Lars
2010-01-01
Limit State analysis has been used in manual design methods for decades e.g. the yield line theory for concrete slabs.......Limit State analysis has been used in manual design methods for decades e.g. the yield line theory for concrete slabs....
Some distance bounds of branching processes and their diffusion limits
Kammerer, Niels B
2010-01-01
We compute exact values respectively bounds of "distances" - in the sense of (transforms of) power divergences and relative entropy - between two discrete-time Galton-Watson branching processes with immigration GWI for which the offspring as well as the immigration is arbitrarily Poisson-distributed (leading to arbitrary type of criticality). Implications for asymptotic distinguishability behaviour in terms of contiguity and entire separation of the involved GWI are given, too. Furthermore, we determine the corresponding limit quantities for the context in which the two GWI converge to Feller-type branching diffusion processes, as the time-lags between observations tend to zero. Some applications to (static random environment like) Bayesian decision making and Neyman-Pearson testing are presented as well.
Evaluating risk using bounding calculations and limited data
Energy Technology Data Exchange (ETDEWEB)
COWLEY, W.L.
1999-05-27
This paper describes a methodology for estimating the potential risk to workers and the public from igniting organic solvents in any of the 177 underground waste storage tanks at the Hanford Site in southeastern Washington state. The Hanford Site is one of the U.S. Department of Energy's former production facilities for nuclear materials. The tanks contain mixed radioactive wastes. Risk is measured by calculating toxicological and radiological accident consequences and frequencies and comparing the results to established regulatory guidelines. Available sample data is insufficient to adequately characterize the waste and solvent, so a model that maximizes releases from the tanks (bounding case) is used. Maximizing releases (and thus consequences) is a standard technique used in safety analysis to compensate for lack of information. The model predicts bounding values of fire duration, the time at which the fire extinguishes because of lack of oxygen, and a pressure history of a fire in a tank. The model output is used to calculate mass and volume release rates of material from the tanks. The mass and volume release rates permit calculation of radiological and toxicological consequences. The resulting consequence calculations demonstrate that risk from an organic solvent fire in the tanks is within regulatory guidelines.
Evaluating risk using bounding calculations and limited data; TOPICAL
International Nuclear Information System (INIS)
This paper describes a methodology for estimating the potential risk to workers and the public from igniting organic solvents in any of the 177 underground waste storage tanks at the Hanford Site in southeastern Washington state. The Hanford Site is one of the U.S. Department of Energy's former production facilities for nuclear materials. The tanks contain mixed radioactive wastes. Risk is measured by calculating toxicological and radiological accident consequences and frequencies and comparing the results to established regulatory guidelines. Available sample data is insufficient to adequately characterize the waste and solvent, so a model that maximizes releases from the tanks (bounding case) is used. Maximizing releases (and thus consequences) is a standard technique used in safety analysis to compensate for lack of information. The model predicts bounding values of fire duration, the time at which the fire extinguishes because of lack of oxygen, and a pressure history of a fire in a tank. The model output is used to calculate mass and volume release rates of material from the tanks. The mass and volume release rates permit calculation of radiological and toxicological consequences. The resulting consequence calculations demonstrate that risk from an organic solvent fire in the tanks is within regulatory guidelines
OFFSITE RADIOLOGICAL CONSEQUENCE ANALYSIS FOR THE BOUNDING FLAMMABLE GAS ACCIDENT
International Nuclear Information System (INIS)
This document quantifies the offsite radiological consequences of the bounding flammable gas accident for comparison with the 25 rem Evaluation Guideline established in DOE-STD-3009, Appendix A. The bounding flammable gas accident is a detonation in a SST. The calculation applies reasonably conservative input parameters in accordance with guidance in DOE-STD-3009, Appendix A. The purpose of this analysis is to calculate the offsite radiological consequence of the bounding flammable gas accident. DOE-STD-3009-94, ''Preparation Guide for US. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', requires the formal quantification of a limited subset of accidents representing a complete set of bounding conditions. The results of these analyses are then evaluated to determine if they challenge the DOE-STD-3009-94, Appendix A, ''Evaluation Guideline,'' of 25 rem total effective dose equivalent in order to identify and evaluate safety-class structures, systems, and components. The bounding flammable gas accident is a detonation in a single-shell tank (SST). A detonation versus a deflagration was selected for analysis because the faster flame speed of a detonation can potentially result in a larger release of respirable material. A detonation in an SST versus a double-shell tank (DST) was selected as the bounding accident because the estimated respirable release masses are the same and because the doses per unit quantity of waste inhaled are greater for SSTs than for DSTs. Appendix A contains a DST analysis for comparison purposes
The Limits of Bound Structures in the Accelerating Universe
D"unner, R; Meza, A; Reisenegger, A; D\\"unner, Rolando; Araya, Pablo A.; Meza, Andr\\'es; Reisenegger, Andreas
2006-01-01
According to the latest evidence, the Universe is entering an era of exponential expansion, where gravitationally bound structures will get disconnected from each other, forming isolated `island universes'. In this scenario, we present a theoretical criterion to determine the boundaries of gravitationally bound structures and a physically motivated definition of superclusters as the largest bound structures in the Universe. We use the spherical collapse model self-consistently to obtain an analytical condition for the mean density enclosed by the last bound shell of the structure (2.36 times the critical density in the present Universe, assumed to be flat, with 30 per cent matter and 70 per cent cosmological constant, in agreement with the previous, numerical result of Chiueh and He). $N$-body simulations extended to the future show that this criterion, applied at the present cosmological epoch, defines a sphere that encloses $\\approx 99.7$ per cent of the particles that will remain bound to the structure at ...
Quantum computation speedup limits from quantum metrological precision bounds
Demkowicz-Dobrzanski, Rafal; Markiewicz, Marcin
2014-01-01
We propose a scheme for translating metrological precision bounds into lower bounds on query complexity of quantum search algorithms. Within the scheme the link between quadratic performance enhancement in idealized quantum metrological and quantum computing schemes becomes clear. More importantly, we utilize results from the field of quantum metrology on a generic loss of quadratic quantum precision enhancement in presence of decoherence to infer an analogous generic loss of quadratic speed-...
Offsite radiological consequence analysis for the bounding flammable gas accident
International Nuclear Information System (INIS)
The purpose of this analysis is to calculate the offsite radiological consequence of the bounding flammable gas accident. DOE-STD-3009-94, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', requires the formal quantification of a limited subset of accidents representing a complete set of bounding conditions. The results of these analyses are then evaluated to determine if they challenge the DOE-STD-3009-94, Appendix A, ''Evaluation Guideline,'' of 25 rem total effective dose equivalent in order to identify and evaluate safety class structures, systems, and components. The bounding flammable gas accident is a detonation in a single-shell tank (SST). A detonation versus a deflagration was selected for analysis because the faster flame speed of a detonation can potentially result in a larger release of respirable material. As will be shown, the consequences of a detonation in either an SST or a double-shell tank (DST) are approximately equal. A detonation in an SST was selected as the bounding condition because the estimated respirable release masses are the same and because the doses per unit quantity of waste inhaled are generally greater for SSTs than for DSTs. Appendix A contains a DST analysis for comparison purposes
International Nuclear Information System (INIS)
In this paper it is presented a variational method for the limit analysis of an ideal plastic solid. This method has been denominated as Modified Secundary Creep and enables to find the collapse loads through a minimization of a functional and a limit process. Given an ideal plastic material it is shown how to determinate the associated secundary creep constitutive equation. Finally, as an application, it is found the limit load in an pressurized von Mises rigid plastic sphere. (Author)
Institute of Scientific and Technical Information of China (English)
安晨歌; 张建红; 周敏; 朱政
2011-01-01
海床中的天然气水合物分解后由固体变为气体,将直接提高孔隙水压力,减小边坡内有效应力,导致边坡稳定性下降.本文以能量上限定理为理论基础,采用二维极限分析方法分析海底缓倾角边坡的滑坡机理,研究由于水合物分解形成的软弱夹层对边坡稳定性的影响.分析表明,软弱夹层的埋深和海床土体内摩擦角会对边坡的稳定性产生直接影响.由于水合物分解而产生的膨胀压力也会降低海底缓倾角边坡的稳定性.%It is indicated by some experimental and theoretical data that the disassociation of gas hydrate could directly increase pore water pressure, decrease effective stresses in the submarine slope, reduce the friction coefficient between different soil layers in slope, and in consequence the slope stability will be weakened. In this paper, a two-dimensional numerical limit analysis, incorporating the upper-bound energy method, is presented to improve the understanding of the failure mechanism of submarine low-angle slope. Based on the analysis, it is found that the internal friction angle and the burial depth of weak layer affect the slope stability. It is also found that the expansion pressure due to gas hydrate disassociation in weak layer can affect the stability also.
Organically bound tritium analysis in environmental samples
Energy Technology Data Exchange (ETDEWEB)
Baglan, N. [CEA/DAM/DIF, Arpajon (France); Kim, S.B. [AECL, Chalk River Laboratories, Chalk River, ON (Canada); Cossonnet, C. [IRSN/PRP-ENV/STEME/LMRE, Orsay (France); Croudace, I.W.; Warwick, P.E. [GAU-Radioanalytical, University of Southampton, Southampton (United Kingdom); Fournier, M. [IRSN/DG/DMQ, Fontenay-aux-Roses (France); Galeriu, D. [IFIN-HH, Horia-Hulubei, Inst. Phys. and Nucl. Eng., Bucharest (Romania); Momoshima, N. [Kyushu University, Radioisotope Ctr., Fukuoka (Japan); Ansoborlo, E. [CEA/DEN/DRCP/CETAMA, Bagnols-sur-Ceze (France)
2015-03-15
Organically bound tritium (OBT) has become of increased interest within the last decade, with a focus on its behaviour and also its analysis, which are important to assess tritium distribution in the environment. In contrast, there are no certified reference materials and no standard analytical method through the international organization related to OBT. In order to resolve this issue, an OBT international working group was created in May 2012. Over 20 labs from around the world participated and submitted their results for the first intercomparison exercise results on potato (Sep 2013). The samples, specially-prepared potatoes, were provided in March 2013 to each participant. Technical information and results from this first exercise are discussed here for all the labs which have realised the five replicates necessary to allow a reliable statistical treatment. The results are encouraging as the increased number of participating labs did not degrade the observed dispersion of the results for a similar activity level. Therefore, the results do not seem to depend on the analytical procedure used. From this work an optimised procedure can start to be developed to deal with OBT analysis and will guide subsequent planned OBT trials by the international group.
Organically bound tritium analysis in environmental samples
International Nuclear Information System (INIS)
Organically bound tritium (OBT) has become of increased interest within the last decade, with a focus on its behaviour and also its analysis, which are important to assess tritium distribution in the environment. In contrast, there are no certified reference materials and no standard analytical method through the international organization related to OBT. In order to resolve this issue, an OBT international working group was created in May 2012. Over 20 labs from around the world participated and submitted their results for the first intercomparison exercise results on potato (Sep 2013). The samples, specially-prepared potatoes, were provided in March 2013 to each participant. Technical information and results from this first exercise are discussed here for all the labs which have realised the five replicates necessary to allow a reliable statistical treatment. The results are encouraging as the increased number of participating labs did not degrade the observed dispersion of the results for a similar activity level. Therefore, the results do not seem to depend on the analytical procedure used. From this work an optimised procedure can start to be developed to deal with OBT analysis and will guide subsequent planned OBT trials by the international group
Bound states of fermions on 2D lattice in a dilute limit
International Nuclear Information System (INIS)
We examine extended bound states in a dilute limit of the extended Hubbard model on the two-dimensional square lattice. By solving exactly the two-body problem we have determined the binding energies, mobilities and dispersion curves across the Brillouin zone for bound states of various symmetries. It turns out that the d-wave pairing is strongly favoured by the nnn hopping and the intersite local pairs can have small effective masses, even on the case of strong binding.We have also found a possibility of extended s-dx2-y2 mixing of the bound states. (author)
Limitations of Lower-Bound Methods for the Wire Complexity of Boolean Operators
Drucker, Andrew
2012-01-01
We study the circuit complexity of Boolean operators, i.e., collections of Boolean functions defined over a common input. Our focus is the well-studied model in which arbitrary Boolean functions are allowed as gates, and in which a circuit's complexity is measured by its depth and number of wires. We show sharp limitations of several existing lower-bound methods for this model. First, we study an information-theoretic lower-bound method due to Cherukhin, that yields bounds of form $\\Omega_d(n...
Simplified Drift Analysis for Proving Lower Bounds in Evolutionary Computation
DEFF Research Database (Denmark)
Oliveto, Pietro S.; Witt, Carsten
2011-01-01
Drift analysis is a powerful tool used to bound the optimization time of evolutionary algorithms (EAs). Various previous works apply a drift theorem going back to Hajek in order to show exponential lower bounds on the optimization time of EAs. However, this drift theorem is tedious to read and to...
The condition of a finite Markov chain and perturbation bounds for the limiting probabilities
Meyer, C. D., Jr.
1979-01-01
The inequalities bounding the relative error the norm of w- w squiggly/the norm of w are exhibited by a very simple function of E and A. Let T denote the transition matrix of an ergodic chain, C, and let A = I - T. Let E be a perturbation matrix such that T squiggly = T - E is also the transition matrix of an ergodic chain, C squiggly. Let w and w squiggly denote the limiting probability (row) vectors for C and C squiggly. The inequality is the best one possible. This bound can be significant in the numerical determination of the limiting probabilities for an ergodic chain. In addition to presenting a sharp bound for the norm of w-w squiggly/the norm of w an explicit expression for w squiggly will be derived in which w squiggly is given as a function of E, A, w and some other related terms.
Size-change Termination and Bound Analysis
DEFF Research Database (Denmark)
Avery, James Emil
2006-01-01
Despite its simplicity, the size-change termination principle, presented by Lee, Jones and Ben-Amram in [LJB01], is surprisingly strong and is able to show termination for a large class of programs. A significant limitation for its use, however, is the fact that the SCT requires data types to be...... well-founded, and that all mechanisms used to determine termination must involve decreases in these global, well-founded partial orders. Following is an extension of the size-change principle that allows for non-well founded data types, and a realization of this principle for integer data types. The...... extended size-change principle is realized through combining abstract interpretation over the domain of convex polyhedra with the use of size-change graphs. In the cases when data types are well founded, the method handles every case that is handled by LJB size-change termination. The method has been...
Numerical Limit Analysis of Reinforced Concrete Structures
DEFF Research Database (Denmark)
Larsen, Kasper Paaske
For more than half a century, limit state analysis based on the extremum principles have been used to assess the load bearing capacity of reinforced concrete structures. Extensi- ve research within the field has lead to several techniques for performing such analysis manually. While these manual...... limit state analysis problems. The work focuses on determination of the load bearing capacity of reinforced concrete structures by employing the lower bound theorem and a finite element method using equilibrium elements is developed. The recent year’s development within the field of convex optimization...... is applied to solve the limit state problems. Three different element types have been developed and tested. The first is a solid tetra- hedral element with a linear stress distribution. The tri-axial stress state in the element is decomposed into concrete and reinforcement stresses, to which separate...
Credibility theory based dynamic control bound optimization for reservoir flood limited water level
Jiang, Zhiqiang; Sun, Ping; Ji, Changming; Zhou, Jianzhong
2015-10-01
The dynamic control operation of reservoir flood limited water level (FLWL) can solve the contradictions between reservoir flood control and beneficial operation well, and it is an important measure to make sure the security of flood control and realize the flood utilization. The dynamic control bound of FLWL is a fundamental key element for implementing reservoir dynamic control operation. In order to optimize the dynamic control bound of FLWL by considering flood forecasting error, this paper took the forecasting error as a fuzzy variable, and described it with the emerging credibility theory in recent years. By combining the flood forecasting error quantitative model, a credibility-based fuzzy chance constrained model used to optimize the dynamic control bound was proposed in this paper, and fuzzy simulation technology was used to solve the model. The FENGTAN reservoir in China was selected as a case study, and the results show that, compared with the original operation water level, the initial operation water level (IOWL) of FENGTAN reservoir can be raised 4 m, 2 m and 5.5 m respectively in the three division stages of flood season, and without increasing flood control risk. In addition, the rationality and feasibility of the proposed forecasting error quantitative model and credibility-based dynamic control bound optimization model are verified by the calculation results of extreme risk theory.
Limits on cold dark matter cosmologies from new anisotropy bounds on the cosmic microwave background
Vittorio, Nicola; Meinhold, Peter; Lubin, Philip; Muciaccia, Pio Francesco; Silk, Joseph
1991-01-01
A self-consistent method is presented for comparing theoretical predictions of and observational upper limits on CMB anisotropy. New bounds on CDM cosmologies set by the UCSB South Pole experiment on the 1 deg angular scale are presented. An upper limit of 4.0 x 10 to the -5th is placed on the rms differential temperature anisotropy to a 95 percent confidence level and a power of the test beta = 55 percent. A lower limit of about 0.6/b is placed on the density parameter of cold dark matter universes with greater than about 3 percent baryon abundance and a Hubble constant of 50 km/s/Mpc, where b is the bias factor, equal to unity only if light traces mass.
Competition analysis of a triopoly game with bounded rationality
International Nuclear Information System (INIS)
Highlights: ► We model a Cournot triopoly game with three boundedly rational players. ► The equilibrium points of the model and their local stability are investigated. ► We study the dynamics of this model as varying the parameters. ► The stability of Nash equilibrium is lost and a chaotic behaviors occur. - Abstract: A dynamic Cournot game characterized by three boundedly rational players is modeled by three nonlinear difference equations. The stability of the equilibria of the discrete dynamical system is analyzed. As some parameters of the model are varied, the stability of Nash equilibrium is lost and a complex chaotic behavior occurs. Numerical simulation results show that complex dynamics, such as, bifurcations and chaos are displayed when the value of speed of adjustment is high. The global complexity analysis can help players to take some measures and avoid the collapse of the output dynamic competition game.
McNicholl, Patrick J.; Crabtree, Peter N.
2014-09-01
Applications of stellar occultation by solar system objects have a long history for determining universal time, detecting binary stars, and providing estimates of sizes of asteroids and minor planets. More recently, extension of this last application has been proposed as a technique to provide information (if not complete shadow images) of geosynchronous satellites. Diffraction has long been recognized as a source of distortion for such occultation measurements, and models subsequently developed to compensate for this degradation. Typically these models employ a knife-edge assumption for the obscuring body. In this preliminary study, we report on the fundamental limitations of knife-edge position estimates due to shot noise in an otherwise idealized measurement. In particular, we address the statistical bounds, both Cramér- Rao and Hammersley-Chapman-Robbins, on the uncertainty in the knife-edge position measurement, as well as the performance of the maximum-likelihood estimator. Results are presented as a function of both stellar magnitude and sensor passband; the limiting case of infinite resolving power is also explored.
Three-nucleon bound states and the Wigner-SU(4) limit
Vanasse, Jared
2016-01-01
We examine the extent to which the properties of three-nucleon bound states are well-reproduced in the limit that nuclear forces satisfy Wigner's SU(4) (spin-isospin) symmetry. To do this we compute the charge radii up to next-to-leading order (NLO) in an effective field theory (EFT) that is an expansion in powers of $R/a$, with $R$ the range of the nuclear force and $a$ the nucleon-nucleon ($N\\!N$) scattering lengths. In the Wigner-SU(4) limit, the triton and Helium-3 point charge radii are equal. At NLO in the range expansion both are $1.66$ fm. Adding the first-order corrections due to the breaking of Wigner symmetry in the $N\\!N$ scattering lengths gives a ${}^3\\mathrm{H}$ point charge radius of $1.58$ fm, which is remarkably close to the experimental number, $1.5978\\pm0.040$ fm. For the ${}^3\\mathrm{He}$ point charge radius we find $1.70$ fm, about 4% away from the experimental value of $1.77527\\pm0.0054$ fm. We also examine the Faddeev components that enter the tri-nucleon wave function and find that an...
A time-dependent Tsirelson's bound from limits on the rate of information gain in quantum systems
Energy Technology Data Exchange (ETDEWEB)
Doherty, Andrew C [Centre for Engineered Quantum Systems, School of Physics, University of Sydney, Sydney (Australia); Wehner, Stephanie, E-mail: wehner@comp.nus.edu.sg [Centre for Quantum Technologies, National University of Singapore, 2 Science Drive 3, 117543 Singapore (Singapore)
2011-07-15
We consider the problem of distinguishing between a set of arbitrary quantum states in a setting in which the time available to perform the measurement is limited. We provide simple upper bounds on how well we can perform state discrimination in a given time as a function of either the average energy or the range of energies available during the measurement. We exhibit a specific strategy that nearly attains this bound. Finally, we consider several applications of our result. Firstly, we obtain a time-dependent Tsirelson's bound that limits the extent of the Bell inequality violation that can be in principle be demonstrated in a given time t. Secondly, we obtain a Margolus-Levitin type bound when considering the special case of distinguishing orthogonal pure states.
Extrinsic Isoperimetric Analysis on Submanifolds with Curvatures bounded from below
DEFF Research Database (Denmark)
Markvorsen, Steen; Palmer, Vicente
2010-01-01
We obtain upper bounds for the isoperimetric quotients of extrinsic balls of submanifolds in ambient spaces which have a lower bound on their radial sectional curvatures. The submanifolds are themselves only assumed to have lower bounds on the radial part of the mean curvature vector field and on...
Canadian inter-laboratory organically bound tritium (OBT) analysis exercise.
Kim, S B; Olfert, J; Baglan, N; St-Amant, N; Carter, B; Clark, I; Bucur, C
2015-12-01
Tritium emissions are one of the main concerns with regard to CANDU reactors and Canadian nuclear facilities. After the Fukushima accident, the Canadian Nuclear Regulatory Commission suggested that models used in risk assessment of Canadian nuclear facilities be firmly based on measured data. Procedures for measurement of tritium as HTO (tritiated water) are well established, but there are no standard methods and certified reference materials for measurement of organically bound tritium (OBT) in environmental samples. This paper describes and discusses an inter-laboratory comparison study in which OBT in three different dried environmental samples (fish, Swiss chard and potato) was measured to evaluate OBT analysis methods currently used by CANDU Owners Group (COG) members. The variations in the measured OBT activity concentrations between all laboratories were less than approximately 20%, with a total uncertainty between 11 and 17%. Based on the results using the dried samples, the current OBT analysis methods for combustion, distillation and counting are generally acceptable. However, a complete consensus OBT analysis methodology with respect to freeze-drying, rinsing, combustion, distillation and counting is required. Also, an exercise using low-level tritium samples (less than 100 Bq/L or 20 Bq/kg-fresh) would be useful in the near future to more fully evaluate the current OBT analysis methods. PMID:26372740
Persistence-Based Branch Misprediction Bounds for WCET Analysis
DEFF Research Database (Denmark)
Puffitsch, Wolfgang
Branch prediction is an important feature of pipelined processors to achieve high performance. However, it can lead to overly pessimistic worst-case execution time (WCET) bounds when being modeled too conservatively. This paper presents bounds on the number of branch mispredictions for local...... dynamic branch predictors. To handle interferences between branch instructions we use the notion of persistence, a concept that is also found in cache analyses. The bounds apply to branches in general, not only to branches that close a loop. Furthermore, the bounds can be easily integrated into integer...... linear programming formulations of the WCET problem. An evaluation on a number of benchmarks shows that with these bounds, dynamic branch prediction does not necessarily lead to higher WCET bounds than static prediction schemes....
Tsai, Ching-Wei; Tsai, Chieh; Ruaan, Ruoh-Chyu; Hu, Chien-Chieh; Lee, Kueir-Rarn
2013-06-26
Interfacial polymerization of four aqueous phase monomers, diethylenetriamine (DETA), m-phenylenediamine (mPD), melamine (Mela), and piperazine (PIP), and two organic phase monomers, trimethyl chloride (TMC) and cyanuric chloride (CC), produce a thin-film composite membrane of polymerized polyamide layer capable of O2/N2 separation. To achieve maximum efficiency in gas permeance and O2/N2 permselectivity, the concentrations of monomers, time of interfacial polymerization, number of reactive groups in monomers, and the structure of monomers need to be optimized. By controlling the aqueous/organic monomer ratio between 1.9 and 2.7, we were able to obtain a uniformly interfacial polymerized layer. To achieve a highly cross-linked layer, three reactive groups in both the aqueous and organic phase monomers are required; however, if the monomers were arranged in a planar structure, the likelihood of structural defects also increased. On the contrary, linear polymers are less likely to result in structural defects, and can also produce polymer layers with moderate O2/N2 selectivity. To minimize structural defects while maximizing O2/N2 selectivity, the planar monomer, TMC, containing 3 reactive groups, was reacted with the semirigid monomer, PIP, containing 2 reactive groups to produce a membrane with an adequate gas permeance of 7.72 × 10(-6) cm(3) (STP) s(-1) cm(-2) cm Hg(-1) and a high O2/N2 selectivity of 10.43, allowing us to exceed the upper-bound limit of conventional thin-film composite membranes. PMID:23731366
Analysis of high temperature limits on concrete nuclear structures
International Nuclear Information System (INIS)
To deal with the uncertainties involved in determination of safe temperature limits for concrete nuclear structures and obtain a qualitative measure of safety margins, a sensitivity analysis approach is introduced. Using this approach, bounds of structural performance limits are established and temperature level giving adequate margin of safety is determined. For irradiated fuel storage bays with single or double walled construction, envelope curves of temperature limits are drawn from which operating and safety limit temperatures are determined. To obtain more definitive information on concrete cracking and structural behaviour under thermal loads an experimental program has been initiated. The progress of this test program is reported
Offsite radiological consequence analysis for the bounding aircraft crash accident
International Nuclear Information System (INIS)
The purpose of this calculation note is to quantitatively analyze a bounding aircraft crash accident for comparison to the DOE-STD-3009-94, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', Appendix A, Evaluation Guideline of 25 rem. The potential of aircraft impacting a facility was evaluated using the approach given in DOE-STD-3014-96, ''Accident Analysis for Aircraft Crash into Hazardous Facilities''. The following aircraft crash FR-equencies were determined for the Tank Farms in RPP-11736, ''Assessment Of Aircraft Crash FR-equency For The Hanford Site 200 Area Tank Farms'': (1) The total aircraft crash FR-equency is ''extremely unlikely.'' (2) The general aviation crash FR-equency is ''extremely unlikely.'' (3) The helicopter crash FR-equency is ''beyond extremely unlikely.'' (4) For the Hanford Site 200 Areas, other aircraft type, commercial or military, each above ground facility, and any other type of underground facility is ''beyond extremely unlikely.'' As the potential of aircraft crash into the 200 Area tank farms is more FR-equent than ''beyond extremely unlikely,'' consequence analysis of the aircraft crash is required
Jiang, Ning; Masmoudi, Nader
2015-01-01
We establish the incompressible Navier-Stokes-Fourier limit for solutions to the Boltzmann equation with a general cut-off collision kernel in a bounded domain. Appropriately scaled families of DiPerna-Lions-(Mischler) renormalized solutions with Maxwell reflection boundary conditions are shown to have fluctuations that converge as the Knudsen number goes to zero. Every limit point is a weak solution to the Navier-Stokes-Fourier system with different types of boundary conditions depending on ...
Institute of Scientific and Technical Information of China (English)
刘杰; 黄达; 杨超; 孙莎
2015-01-01
Stability analysis of gravity retaining wall was currently based on the assumption that the wall had no embedment depth. The effect of earth berm was usually neglected. The present work highlighted the importance of embedment depth when assessing the seismic stability of gravity retaining walls with the pattern of pure rotation. In the framework of upper bound theorem of limit analysis, pseudo-static method was applied into two groups of parallel rigid soil slices methods in order to account for the effect of embedment depth on evaluating the critical acceleration of wall-soil system. The present analytical solution is identical to the results obtained from using limit equilibrium method, and the two methods are based on different theory backgrounds. Parameter analysis indicates that the critical acceleration increases slowly when the ratio of the embedment depth to the total height of the wall is from 0 to 0.15 and increases drastically when the ratio exceeds 0.15.
The Effect of Additional Funds for Low-Ability Pupils - A Nonparametric Bounds Analysis
de Haan, Monique
2012-01-01
This paper investigates the effect of a policy measure that gives secondary schools additional resources for low-ability pupils. Schools are free in deciding how to spend the additional money. I use a nonparametric bounds analysis to estimate upper and lower bounds on the effect of additional funds on exam results of pupils. First I investigate what can be concluded without imposing assumptions; next I layer weak nonparametric assumptions to tighten the bounds. The tightest bounds show that t...
Placing direct limits on the mass of earth-bound dark matter
International Nuclear Information System (INIS)
We point out that by comparing the total mass (in gravitational units) of the earth-moon system, as determined by lunar laser ranging, with the sum of the lunar mass as independently determined by its gravitational action on satellites or asteroids, and the earth mass, as determined by the LAGEOS geodetic survey satellite, one can get a direct measure of the mass of earth-bound dark matter lying between the radius of the moon's orbit and the geodetic satellite orbit. Current data show that the mass of such earth-bound dark matter must be less than 4 x 10-9 of the earth's mass. (fast track communication)
Placing direct limits on the mass of earth-bound dark matter
Adler, Stephen L
2008-01-01
We point out that by comparing the total mass (in gravitational units) of the earth-moon system, as determined by lunar laser ranging, with the sum of the lunar mass as independently determined by its gravitational action on satellites or asteroids, and the earth mass, as determined by the LAGEOS geodetic survey satellite, one can get a direct measure of the mass of earth-bound dark matter lying between the radius of the moon's orbit and the geodetic satellite orbit. Current data show that the mass of such earth-bound dark matter must be less than $4 \\times 10^{-9}$ of the earth's mass.
Offsite Radiological Consequence Analysis for the Bounding Flammable Gas Accident
Carro, C A
2003-01-01
This document quantifies the offsite radiological consequences of the bounding flammable gas accident for comparison with the 25 rem Evaluation Guideline established in DOE-STD-3009, Appendix A. The bounding flammable gas accident is a detonation in a single-shell tank The calculation applies reasonably conservation input parameters in accordance with DOE-STD-3009, Appendix A, guidance. Revision 1 incorporates comments received from Office of River Protection.
Analysis of the contact graph routing algorithm: Bounding interplanetary paths
Birrane, Edward; Burleigh, Scott; Kasch, Niels
2012-06-01
Interplanetary communication networks comprise orbiters, deep-space relays, and stations on planetary surfaces. These networks must overcome node mobility, constrained resources, and significant propagation delays. Opportunities for wireless contact rely on calculating transmit and receive opportunities, but the Euclidean-distance diameter of these networks (measured in light-seconds and light-minutes) precludes node discovery and contact negotiation. Propagation delay may be larger than the line-of-sight contact between nodes. For example, Mars and Earth orbiters may be separated by up to 20.8 min of signal propagation time. Such spacecraft may never share line-of-sight, but may uni-directionally communicate if one orbiter knows the other's future position. The Contact Graph Routing (CGR) approach is a family of algorithms presented to solve the messaging problem of interplanetary communications. These algorithms exploit networks where nodes exhibit deterministic mobility. For CGR, mobility and bandwidth information is pre-configured throughout the network allowing nodes to construct transmit opportunities. Once constructed, routing algorithms operate on this contact graph to build an efficient path through the network. The interpretation of the contact graph, and the construction of a bounded approximate path, is critically important for adoption in operational systems. Brute force approaches, while effective in small networks, are computationally expensive and will not scale. Methods of inferring cycles or other librations within the graph are difficult to detect and will guide the practical implementation of any routing algorithm. This paper presents a mathematical analysis of a multi-destination contact graph algorithm (MD-CGR), demonstrates that it is NP-complete, and proposes realistic constraints that make the problem solvable in polynomial time, as is the case with the originally proposed CGR algorithm. An analysis of path construction to complement hop
Semiclassical limit for the nonlinear Klein Gordon equation in bounded domains
Ghimenti, Marco G
2010-01-01
We are interested to the existence of standing waves for the nonlinear Klein Gordon equation {\\epsilon}^2{\\box}{\\psi} + W'({\\psi}) = 0 in a bounded domain D. The main result of this paper is that, under suitable growth condition on W, for {\\epsilon} sufficiently small, we have at least cat(D) standing wavesfor the equation ({\\dag}), while cat(D) is the Ljusternik-Schnirelmann category.
(p,q)-Five Brane and (p,q)-String Solutions, their Bound State and its Near Horizon Limit
Kluson, J
2016-01-01
We determine (p,q)-string and (p,q)-five brane solutions of type IIB supergravity using SL(2,Z)-symmetry of the full type IIB superstring theory. We also determine SL(2,Z)-transformed solution corresponding to the bound state of NS5-branes and fundamental strings. Then we analyze its near horizon limit and we show that it leads to the AdS(3)xS(3) with mixed fluxes.
( p, q)-five brane and ( p, q)-string solutions, their bound state and its near horizon limit
Klusoň, Josef
2016-06-01
We determine ( p, q)-string and ( p, q)-five brane solutions of type IIB supergravity using SL (2 , ℤ)-symmetry of the full type IIB superstring theory. We also determine SL (2 , ℤ)-transformed solution corresponding to the bound state of NS5-branes and fundamental strings. Then we analyze its near horizon limit and we show that it leads to the AdS3 × S 3 with mixed fluxes.
Placing direct limits on the mass of earth-bound dark matter
Adler, Stephen L.
2008-01-01
We point out that by comparing the total mass (in gravitational units) of the earth-moon system, as determined by lunar laser ranging, with the sum of the lunar mass as independently determined by its gravitational action on satellites or asteroids, and the earth mass, as determined by the LAGEOS geodetic survey satellite, one can get a direct measure of the mass of earth-bound dark matter lying between the radius of the moon's orbit and the geodetic satellite orbit. Current data show that th...
Fundamental dispersion limit for spectrally bounded On-Off-Keying communication channels
Granot, Er'el
2012-01-01
The fundamental dispersion limit for optical communication based the On-Off-Keying format is calculated. It is shown both analytically and with numerical simulations that an OOK optical sequence, which passes through spectrally narrow noncompensated dispersive channel cannot exceed the limit 1/{\\pi} > {\\beta_2} L B^2, where {\\beta_2}, L and B are the dispersion coefficient, the fiber's length and the bit-rate respectively. To the best of our knowledge, this is the first time that such a fundamental limit was formulated. In the literature, only approximation evaluations were developed yielding much smaller limiting values.
Bayesian analysis of repairable systems showing a bounded failure intensity
International Nuclear Information System (INIS)
The failure pattern of repairable mechanical equipment subject to deterioration phenomena sometimes shows a finite bound for the increasing failure intensity. A non-homogeneous Poisson process with bounded increasing failure intensity is then illustrated and its characteristics are discussed. A Bayesian procedure, based on prior information on model-free quantities, is developed in order to allow technical information on the failure process to be incorporated into the inferential procedure and to improve the inference accuracy. Posterior estimation of the model-free quantities and of other quantities of interest (such as the optimal replacement interval) is provided, as well as prediction on the waiting time to the next failure and on the number of failures in a future time interval is given. Finally, numerical examples are given to illustrate the proposed inferential procedure
Boundness of a Neural Network Weights Using the Notion of a Limit of a Sequence
Directory of Open Access Journals (Sweden)
Hazem Migdady
2014-05-01
Full Text Available feed forward neural network with backpropagation learning algorithm is considered as a black box learning classifier since there is no certain interpretation or anticipation of the behavior of a neural network weights. The weights of a neural network are considered as the learning tool of the classifier, and the learning task is performed by the repetition modification of those weights. This modification is performed using the delta rule which is mainly used in the gradient descent technique. In this article a proof is provided that helps to understand and explain the behavior of the weights in a feed forward neural network with backpropagation learning algorithm. Also, it illustrates why a feed forward neural network is not always guaranteed to converge in a global minimum. Moreover, the proof shows that the weights in the neural network are upper bounded (i.e. they do not approach infinity.
Bound H-dibaryon in Flavor SU(3) Limit of Lattice QCD
Inoue, Takashi; Aoki, Sinya; Doi, Takumi; Hatsuda, Tetsuo; Ikeda, Yoichi; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji
2010-01-01
The flavor-singlet H-dibaryon, which has strangeness -2 and baryon number 2, is studied by the approach recently developed for the baryon-baryon interactions in lattice QCD. The flavor-singlet central potential is derived from the spatial and imaginary-time dependence of the Nambu-Bethe-Salpeter wave function measured in N_f=3 full QCD simulations with the lattice size of L = 2, 3, 4 fm. The potential is found to be insensitive to the volume, and it leads to a bound H-dibaryon with the binding energy of 30 - 40 MeV for the pseudo-scalar meson mass of 673 - 1015 MeV.
Fitness levels with tail bounds for the analysis of randomized search heuristics
DEFF Research Database (Denmark)
Witt, Carsten
2014-01-01
The fitness-level method, also called the method of f-based partitions, is an intuitive and widely used technique for the running time analysis of randomized search heuristics. It was originally defined to prove upper and lower bounds on the expected running time. Recently, upper tail bounds were...
Finite Element Method and Upper-Bound Type Analysis of Equal Channel Angular Pressing
Directory of Open Access Journals (Sweden)
T. A. Fashanu
2012-10-01
Full Text Available This work presents the analysis of stresses required for a frictionless equal-channel angular pressing (ECAP of perfectly plastic or strain-hardening materials using finite-element method and upper-bound type analysis. Upper-bound type and FEM analysis were analytical approximations and numerical methods respectively. The two methods used and presented agree well for different ECAP die angles and materials.
Yong, Wang
2015-01-01
In the present paper, we study the uniform regularity and vanishing dissipation limit for the full compressible Navier-Stokes system whose viscosity and heat conductivity are allowed to vanish at different order. The problem is studied in a 3-D bounded domain with Navier-slip type boundary conditions \\eqref{1.9}. It is shown that there exists a unique strong solution to the full compressible Navier-Stokes system with the boundary conditions \\eqref{1.9} in a finite time interval which is indep...
Structural Analysis of Iac Repressor Bound to Allosteric Effectors
Energy Technology Data Exchange (ETDEWEB)
Daber,R.; Stayrook, S.; Rosenberg, A.; Lewis, M.
2007-01-01
The lac operon is a model system for understanding how effector molecules regulate transcription and are necessary for allosteric transitions. The crystal structures of the lac repressor bound to inducer and anti-inducer molecules provide a model for how these small molecules can modulate repressor function. The structures of the apo repressor and the repressor bound to effector molecules are compared in atomic detail. All effectors examined here bind to the repressor in the same location and are anchored to the repressor through hydrogen bonds to several hydroxyl groups of the sugar ring. Inducer molecules form a more extensive hydrogen-bonding network compared to anti-inducers and neutral effector molecules. The structures of these effector molecules suggest that the O6 hydroxyl on the galactoside is essential for establishing a water-mediated hydrogen bonding network that bridges the N-terminal and C-terminal sub-domains. The altered hydrogen bonding can account in part for the different structural conformations of the repressor, and is vital for the allosteric transition.
Bifurcation Analysis Using Rigorous Branch and Bound Methods
Smith, Andrew P.; Crespo, Luis G.; Munoz, Cesar A.; Lowenberg, Mark H.
2014-01-01
For the study of nonlinear dynamic systems, it is important to locate the equilibria and bifurcations occurring within a specified computational domain. This paper proposes a new approach for solving these problems and compares it to the numerical continuation method. The new approach is based upon branch and bound and utilizes rigorous enclosure techniques to yield outer bounding sets of both the equilibrium and local bifurcation manifolds. These sets, which comprise the union of hyper-rectangles, can be made to be as tight as desired. Sufficient conditions for the existence of equilibrium and bifurcation points taking the form of algebraic inequality constraints in the state-parameter space are used to calculate their enclosures directly. The enclosures for the bifurcation sets can be computed independently of the equilibrium manifold, and are guaranteed to contain all solutions within the computational domain. A further advantage of this method is the ability to compute a near-maximally sized hyper-rectangle of high dimension centered at a fixed parameter-state point whose elements are guaranteed to exclude all bifurcation points. This hyper-rectangle, which requires a global description of the bifurcation manifold within the computational domain, cannot be obtained otherwise. A test case, based on the dynamics of a UAV subject to uncertain center of gravity location, is used to illustrate the efficacy of the method by comparing it with numerical continuation and to evaluate its computational complexity.
Security Analysis of two Distance-Bounding Protocols
Abyaneh, Mohammad Reza Sohizadeh
2011-01-01
In this paper, we analyze the security of two recently proposed distance bounding protocols called the Hitomi and the NUS protocols. Our results show that the claimed security of both protocols has been overestimated. Namely, we show that the Hitomi protocol is susceptible to a full secret key disclosure attack which not only results in violating the privacy of the protocol but also can be exploited for further attacks such as impersonation, ma?a fraud and terrorist fraud attacks. Our results also demonstrates that the probability of success in a distance fraud attack against the NUS protocol can be increased up to (3/4)^n and even slightly more, if the adversary is furnished with some computational capabilities.
Bounded Linear Stability Analysis - A Time Delay Margin Estimation Approach for Adaptive Control
Nguyen, Nhan T.; Ishihara, Abraham K.; Krishnakumar, Kalmanje Srinlvas; Bakhtiari-Nejad, Maryam
2009-01-01
This paper presents a method for estimating time delay margin for model-reference adaptive control of systems with almost linear structured uncertainty. The bounded linear stability analysis method seeks to represent the conventional model-reference adaptive law by a locally bounded linear approximation within a small time window using the comparison lemma. The locally bounded linear approximation of the combined adaptive system is cast in a form of an input-time-delay differential equation over a small time window. The time delay margin of this system represents a local stability measure and is computed analytically by a matrix measure method, which provides a simple analytical technique for estimating an upper bound of time delay margin. Based on simulation results for a scalar model-reference adaptive control system, both the bounded linear stability method and the matrix measure method are seen to provide a reasonably accurate and yet not too conservative time delay margin estimation.
Computational structural analysis: multiple proteins bound to DNA.
Directory of Open Access Journals (Sweden)
Andrija Tomovic
Full Text Available BACKGROUND: With increasing numbers of crystal structures of proteinratioDNA and proteinratioproteinratioDNA complexes publically available, it is now possible to extract sufficient structural, physical-chemical and thermodynamic parameters to make general observations and predictions about their interactions. In particular, the properties of macromolecular assemblies of multiple proteins bound to DNA have not previously been investigated in detail. METHODOLOGY/PRINCIPAL FINDINGS: We have performed computational structural analyses on macromolecular assemblies of multiple proteins bound to DNA using a variety of different computational tools: PISA; PROMOTIF; X3DNA; ReadOut; DDNA and DCOMPLEX. Additionally, we have developed and employed an algorithm for approximate collision detection and overlapping volume estimation of two macromolecules. An implementation of this algorithm is available at http://promoterplot.fmi.ch/Collision1/. The results obtained are compared with structural, physical-chemical and thermodynamic parameters from proteinratioprotein and single proteinratioDNA complexes. Many of interface properties of multiple proteinratioDNA complexes were found to be very similar to those observed in binary proteinratioDNA and proteinratioprotein complexes. However, the conformational change of the DNA upon protein binding is significantly higher when multiple proteins bind to it than is observed when single proteins bind. The water mediated contacts are less important (found in less quantity between the interfaces of components in ternary (proteinratioproteinratioDNA complexes than in those of binary complexes (proteinratioprotein and proteinratioDNA.The thermodynamic stability of ternary complexes is also higher than in the binary interactions. Greater specificity and affinity of multiple proteins binding to DNA in comparison with binary protein-DNA interactions were observed. However, protein-protein binding affinities are stronger in
Bounding axial profile analysis for the topical report database
International Nuclear Information System (INIS)
Quantifying the open-quotes end effectsclose quotes reactivities of realistic end-of-cycle burnup distributions is important in performing criticality safety analyses for spent fuel shipping containers. Yankee Atomic Electric Company has compiled an axial burnup profile database (ABPD) for a large number of PWR fuel types. The profiles for fuel types with initially uniform axial loadings of U-235 and burnable poisons were collected from the ABPD to form the topical report database (TRD). Based on the TRD, a strategy was set up to find bounding profiles which conservatively estimate the maximum open-quotes end effectsclose quotes reactivities in different burnup ranges. A two-group, one-dimensional diffusion code, REALAX, was used to calculate the k-effectives and open-quotes end effectsclose quotes reactivities for each of the axially varying burnup distributions in the TRD. REALAX was also proven to have consistency with the well-known three-dimensional, multi-group diffusion code, DIF3D
Limit Analysis of 3D Reinforced Concrete Beam Elements
DEFF Research Database (Denmark)
Larsen, Kasper P.; Nielsen, Leif Otto; Poulsen, Peter Noe
2012-01-01
A new finite-element framework for lower-bound limit analysis of reinforced concrete beams, subjected to loading in three dimensions, is presented. The method circumvents the need for a direct formulation of a complex section-force-based yield criterion by creating a discrete representation of the...... Coulomb criterion is applied to the concrete stresses. The modified Coulomb criterion is approximated using second-order cone programming for improved performance over implementations using semidefinite programming. The element is verified by comparing the numerical results with analytical solutions....
Dependence in probabilistic modeling, Dempster-Shafer theory, and probability bounds analysis.
Energy Technology Data Exchange (ETDEWEB)
Oberkampf, William Louis; Tucker, W. Troy (Applied Biomathematics, Setauket, NY); Zhang, Jianzhong (Iowa State University, Ames, IA); Ginzburg, Lev (Applied Biomathematics, Setauket, NY); Berleant, Daniel J. (Iowa State University, Ames, IA); Ferson, Scott (Applied Biomathematics, Setauket, NY); Hajagos, Janos (Applied Biomathematics, Setauket, NY); Nelsen, Roger B. (Lewis & Clark College, Portland, OR)
2004-10-01
This report summarizes methods to incorporate information (or lack of information) about inter-variable dependence into risk assessments that use Dempster-Shafer theory or probability bounds analysis to address epistemic and aleatory uncertainty. The report reviews techniques for simulating correlated variates for a given correlation measure and dependence model, computation of bounds on distribution functions under a specified dependence model, formulation of parametric and empirical dependence models, and bounding approaches that can be used when information about the intervariable dependence is incomplete. The report also reviews several of the most pervasive and dangerous myths among risk analysts about dependence in probabilistic models.
Analysis of cyclic creep and rupture. Part 1: bounding theorems and cyclic reference stresses
International Nuclear Information System (INIS)
Cyclic loading on structures can produce failures not readily predicted by conventional static analysis. Ratcheting or incremental distortion leads to structural failure, and complicates the problems of creep and fatigue prediction. Predicting shakedown, ratcheting, accelerated creep and rupture, for cyclic loading, are the objectives of cyclic stress analysis.Limit load, shakedown and ratcheting analyses provide a comprehensive basis to understand static structural behaviour for ductile inelastic materials, subject to variable loading but excluding inertial dynamic effects. From them we can predict the following failure modes:-Plastic collapse.-Failure to shakedown.-Ratcheting.-Accelerated creep and rupture.This is achieved with a generalisation of the reference stress concept. Conventionally, and for steady loading, the limit load reference stress is the lowest yield stress for which the structure does not collapse. For cyclic loading two definitions are available. The more conservative is the lowest yield stress for which the structure shakes down (behaves elastically). The less conservative is the lowest yield stress for which the structure does not ratchet. They have different meanings and uses.Explaining and justifying the use of cyclic reference stresses to bound creep and rupture is the objective of Part 1. Part 2 gives examples illustrating a range of structural behaviours. The methodology of these papers involves so-called approximate methods at one level, that of inferring limiting or conservative time-dependent behaviour from time-independent elastic-plastic cyclic analyses. The elastic-plastic cyclic analyses themselves are straightforward if tedious. Some ideas and a new analysis technique are available to reduce the trial-and-error
A Comparative Analysis of Success by Project Level Characteristics in the Upward Bound Program
Le, Dat Quang
2002-01-01
A Comparative Analysis of Success by Project Level Characteristics in the Upward Bound Program by Dat Q. Le Gabriella Belli, Ph.D., Chair (Abstract) Data gathered by Mathematica Policy Research, Inc., contractor for the Department of Education were used to analyze successful project level characteristics of the Upward Bound program. Mathematica Policy Research, Inc. provided two data files for this study: a student data file and a grantees data file. The first data...
Gleiser, Marcelo
2013-01-01
Spatially-bound objects across diverse length and energy scales are characterized by a binding energy. We propose that their spatial structure is mathematically encoded as information in their momentum modes and described by a measure known as configurational entropy (CE). Investigating solitonic Q-balls and stars with a polytropic equation of state $P = K{\\rho}^{\\gamma}$, we show that objects with large binding energy have low CE, whereas those at the brink of instability (zero binding energy) have near maximal CE. In particular, we use the CE to find the critical charge allowing for classically stable Q-balls and the Chandrasekhar limit for white dwarfs $({\\gamma} = 4/3)$ with an accuracy of a few percent.
Energy Technology Data Exchange (ETDEWEB)
Gleiser, Marcelo, E-mail: mgleiser@dartmouth.edu; Sowinski, Damian, E-mail: Damian.Sowinski.GR@dartmouth.edu
2013-11-25
Spatially-bound objects across diverse length and energy scales are characterized by a binding energy. We propose that their spatial structure is mathematically encoded as information in their momentum modes and described by a measure known as configurational entropy (CE) [1]. Investigating solitonic Q-balls and stars with a polytropic equation of state P=Kρ{sup γ}, we show that objects with large binding energy have low CE, whereas those at the brink of instability (zero binding energy) have near maximal CE. In particular, we use the CE to find the critical charge allowing for classically stable Q-balls and the Chandrasekhar limit for white dwarfs (γ=4/3) with an accuracy of a few percent.
Bounded Delay Timing Analysis of a Class of CSP Programs
DEFF Research Database (Denmark)
Hulgaard, Henrik; Burns, Steven M.
1997-01-01
We describe an algebraic technique for performing timing analysis of a class of asynchronous circuits described as CSP programs (including Martin's probe operator) with the restrictions that there is no OR-causality and that guard selection is either completely free or mutually exclusive. Such a...... description is transformed into a safe Petri net with interval time delays specified on the places of the net. The timing analysis we perform determines the extreme separation in time between two communication actions of the CSP program for all possible timed executions of the system. We formally define this...
Dey, Rajeeb; Ghosh, Sandip; Ray, Goshaidas; Rakshit, Anjan; Balas, Valentina Emilia
2015-09-01
This paper presents improved robust delay-range-dependent stability analysis of an uncertain linear time-delay system following two different existing approaches - (i) non-delay partitioning (NDP) and (ii) delay partitioning (DP). The derived criterion (for both the approaches) proposes judicious use of integral inequality to approximate the uncertain limits of integration arising out of the time-derivative of Lyapunov-Krasovskii (LK) functionals to obtain less conservative results. Further, the present work compares both the approaches in terms of relative merits as well as highlights tradeoff for achieving higher delay bound and (or) reducing number of decision variables without losing conservatism in delay bound results. The analysis and discussion presented in the paper are validated by considering relevant numerical examples. PMID:26190503
Directory of Open Access Journals (Sweden)
Qi Wang
Full Text Available The energy minimization of a small molecule alone does not automatically stop at a local minimum of the potential energy surface of the molecule if the minimum is shallow, thus leading to folding of the molecule and consequently hampering the generation of the bound conformation of a guest in the absence of its host. This questions the practicality of virtual screening methods that use conformations at local minima of their potential energy surfaces (local minimum conformations as potential bound conformations. Here we report a normal-mode-analysis-monitored energy minimization (NEM procedure that generates local minimum conformations as potential bound conformations. Of 22 selected guest-host complex crystal structures with guest structures possessing up to four rotatable bonds, all complexes were reproduced, with guest mass-weighted root mean square deviations of <1.0 A, through docking with the NEM-generated guest local minimum conformations. An analysis of the potential energies of these local minimum conformations showed that 22 (100%, 18 (82%, 16 (73%, and 12 (55% of the 22 guest bound conformations in the crystal structures had conformational strain energies of less than or equal to 3.8, 2.0, 0.6, and 0.0 kcal/mol, respectively. These results suggest that (1 the NEM procedure can generate small-molecule bound conformations, and (2 guests adopt low-strain-energy conformations for complexation, thus supporting the virtual screening methods that use local minimum conformations.
Tokamak advanced pump limiter experiments and analysis
International Nuclear Information System (INIS)
Experiments with pump limiter modules on several operating tokamaks establish such limiters as efficient collectors of particles and has demonstrated the importance of ballistic scattering as predicted theoretically. Plasma interaction with recycling neutral gas appears to become important as the plasma density increases and the effective ionization mean free path within the module decreases. In limiters with particle collection but without active internal pumping, the neutral gas pressure is found to vary nonlinearly with the edge plasma density at the highest densities studies. Both experiments and theory indicate that the energy spectrum of gas atoms in the pump ducting is non-thermal, consistent with the results of Monte Carlo neutral atom transport calculations. The distribution of plasma power over the front surface of such modules has been measured and appears to be consistent with the predictions of simple theory. Initial results from the latest experiment on the ISX-B tokamak with an actively pumped limiter module demonstrates that the core plasma density can be controlled with a pump limiter and that the scrape-off layer plasma can partially screen the core plasma from gas injection. The results from module pump limiter experiments and from the theory and design analysis of advanced pump limiters for reactors are used to suggest the major features of a definitive, axisymmetric, toroidal belt pump limiter experiment
Strategic analysis of International Forest Products Limited
Modesto, Robin M.
2005-01-01
International Forest Products Limited is a sawmilling company that produces softwood lumber for sale in domestic and international markets including the United States and Japan. Production facilities located in British Columbia, Washington and Oregon produce nearly 1.5 billion board feet of lumber annually. Timber is secured through Crown forest tenure holdings and external open market purchases. This paper includes: a strategic analysis of the firm; an industry analysis; a strategic fit anal...
Seismic limit analysis of masonry structures
Tilahun Bogale, Habtamu
2009-01-01
This thesis presents the limit analysis of masonry structures under the lateral exposures, that’s the most intentionally given sudden earthquakes and also to the associated lateral forces. The current study here in is concerned firstly on the parametric analysis of masonry walls to the lateral loads. Secondly, the analyses of representative existing masonry walls under lateral exposures are done. A simple user friendly but very important software, named Block, is used for this ...
Limit analysis of solid reinforced concrete structures
DEFF Research Database (Denmark)
Larsen, Kasper Paaske
2009-01-01
Recent studies have shown that Semidefinite Programming (SDP) can be used effectively for limit analysis of isotropic cohesive-frictional continuums using the classical Mohr-Coulomb yield criterion. In this paper we expand on this previous research by adding reinforcement to the model and a solid...
Limit analysis and design of containment vessels
International Nuclear Information System (INIS)
In the introduction, the theory of plastic analysis of shells is briefly recalled. Minimum-volume design for assigned load factor at plastic collapse is then considered and optimality criteria are derived for plates and shells of continuously varying or piecewise-constant thickness. In the first part, containers made of metal are examined. Analytical and numerical limit analysis solutions and corresponding experimental results are considered for various types of vessels, including intersecting shells. Attention is given to experimental post-yield behavior. Some tests up to fracture are discussed. New theoretical and experimental results of limit analysis of stiffened cylindrical vessels are presented, in which reinforcing rings are treated as discrete structural element (no smearing out) and due account is taken of their strong curvature. Cases of collapse by instability under internal pressure are pointed out. Minimum-volume design of circular plates and cylindrical shells is then formulated and various examples are presented of sandwich and solid metal structures. Containers of piecewise-constant thickness are given particular attention. Available experimental evidence on minimum-volume design of plates and shells is reviewed and commented upon. The second part deals with reinforced concrete vessels. Cylindrical containers are studied, from both points of view of limit analysis and of limit design with minimum volume of reinforcement. The practical use of the latter solutions is discussed. A third part reviews other loading cases (including cyclic and impact loads) and gives indications on corresponding theories, formulations and solution methods. The last part is devoted to a discussion of the limitations of the methods presented, within the frame of the 'limit states' design philosophy, which is first briefly recalled. Considerations on further research in the field conclude the paper. (orig.)
LimitS - A system for limit state analysis and optimal material layout
DEFF Research Database (Denmark)
Damkilde, Lars; Krenk, Steen
1997-01-01
distribution or an optimal material layout is determined. Through linearization of the yield criteria the optimization problem is stated as a linear programming problem. Within the formulation of the discretized model the optimal lower-bound solution is shown to be an upper-bound solution, and thereby both the...
Metamaterial polarization converter analysis: limits of performance
DEFF Research Database (Denmark)
Markovich, Dmitry L.; Andryieuski, Andrei; Zalkovskij, Maksim;
2013-01-01
In this paper, we analyze the theoretical limits of a metamaterial-based converter with orthogonal linear eigenpolarizations that allow linear-to-elliptical polarization transformation with any desired ellipticity and ellipse orientation. We employ the transmission line approach providing a needed...... a single layer with a ground plane can have 100 % polarization conversion efficiency. We tested our conclusions numerically reaching the designated limits of efficiency using a simple metamaterial design. Our general analysis provides useful guidelines for the metamaterial polarization converter...... level of the design generalization. Our analysis reveals that the maximal conversion efficiency for transmission through a single metamaterial layer is 50 %, while the realistic reflection configuration can give the conversion efficiency up to 90 %. We show that a double layer transmission converter and...
Limitations on the Analysis of Relaxation Studies
Snyder, Chad; Mopsik, Frederick
1998-03-01
Two issues that are commonly ignored in relaxation studies are examined. The first is the issue of interpolation, extrapolation, and analysis of relaxation data over a limited frequency range. We demonstrate that for data without dispersion or overlap, within experimental uncertainty, a Cole-Cole fit cannot be discerned from a Havriliak-Negami fit over a limited, but typical, frequency range. These results have an obvious impact on many of the theoretical models that attempt to give a physical basis to such fitting functions as the Cole-Cole, the Cole-Davidson, the Havriliak-Negami, and the Kohlrausch-Williams-Watts equations. The second issue that is examined is non-isothermal relaxation studies. We examine the question of whether meaningful information can be obtained from relaxation data obtained while scanning in temperature. The implications of these results are generalized to other experiments such as modulated differential scanning calorimetry (MDSC) and dynamic mechanical thermal analysis (DMTA).
Concept analysis: Some limitations and possible solutions
Directory of Open Access Journals (Sweden)
A. Botes
2002-09-01
Full Text Available Concepts are the basic building blocks of scientific knowledge or theoretical frameworks for any discipline. The strength of the theories that guide a discipline is dependent on the quality of the concept analysis. Thus, the utilisation of poorly understood concepts in research and theory development will result in questionable reliability and validity. Concept analysis is associated with the research design of philosophical inquiry. The purpose of philosophical inquiry is to perform research using intellectual analysis to clarify meaning. Traditionally, no empirical (qualitative or quantitative investigations were used to clarify the meaning of concepts. The lack of empirical investigation to clarify concepts, results in certain limitations in the methodology of concept analysis.
Possibilities and limits of surface analysis methods
International Nuclear Information System (INIS)
The possibilities and limits of the surface analysis methods are presented and stated by means of a choice. It is tried to show how to built up a systematology of all methods. Some capable methods are described in detail. The examples of analyses are chosen under the point of view to give a contribution to the questions existing in the Institute for Reactor Development at the moment. (orig.)
Metamaterial Polarization Converter Analysis: Limits of Performance
Markovich, Dmitry L.; Andryieuski, Andrei; Zalkovskij, Maksim; Malureanu, Radu; Lavrinenko, Andrei V.
2012-01-01
In this paper we analyze the theoretical limits of a metamaterial converter that allows for linear-to- elliptical polarization transformation with any desired ellipticity and ellipse orientation. We employ the transmission line approach providing a needed level of the design generalization. Our analysis reveals that the maximal conversion e?ciency for transmission through a single metamaterial layer is 50%, while the realistic re ection con?guration can give the conversion e?ciency up to 90%....
Limits, limits everywhere the tools of mathematical analysis
Applebaum, David
2012-01-01
A quantity can be made smaller and smaller without it ever vanishing. This fact has profound consequences for science, technology, and even the way we think about numbers. In this book, we will explore this idea by moving at an easy pace through an account of elementary real analysis and, in particular, will focus on numbers, sequences, and series.Almost all textbooks on introductory analysis assume some background in calculus. This book doesn't and, instead, the emphasis is on the application of analysis to number theory. The book is split into two parts. Part 1 follows a standard university
Model-Independent Analysis of B -> pi K Decays and Bounds on the Weak Phase gamma
Neubert, Matthias(PRISMA Cluster of Excellence & Mainz Institut for Theoretical Physics, Johannes Gutenberg University, D-55099, Mainz, Germany)
1998-01-01
A general parametrization of the amplitudes for the rare two-body decays B -> pi K is introduced, which makes maximal use of theoretical constraints arising from flavour symmetries of the strong interactions and the structure of the low-energy effective weak Hamiltonian. With the help of this parametrization, a model-independent analysis of the branching ratios and direct CP asymmetries in the various B -> pi K decay modes is performed, and the impact of hadronic uncertainties on bounds on th...
Impact location and load identification through inverse analysis with bounded uncertain measurements
International Nuclear Information System (INIS)
The growing demand for real-time damage assessment necessitates development of an efficient inverse analysis algorithm with consideration of practical issues such as uncertainty in measurement. A mathematical model-based inverse analysis scheme is proposed to identify impact locations and reconstruct impact load time history of a simply supported plate through multiple levels of analysis. The proximity of the impact location is first determined by the triangulation method and the impact location is then refined by minimization of an objective function through the particle swarm optimization method (PSO). Loss of data due to filtration is addressed in a further level by performing an interval analysis based on extreme measurement errors. The outcome of the analyses is a mean impact location, a load time history, and a range of likely deviations. The extreme deviation in impact location is shown by bounding lines, which form a rectangle. The deviation in load time history is also shown by upper and lower bounding sinusoidal curves. The results of the analyses indicate that the proposed method can effectively locate the impact point and reconstruct the load time history even with the existence of noise in the measured response. (paper)
Impact location and load identification through inverse analysis with bounded uncertain measurements
Ahmari, Saeed; Yang, Mijia
2013-08-01
The growing demand for real-time damage assessment necessitates development of an efficient inverse analysis algorithm with consideration of practical issues such as uncertainty in measurement. A mathematical model-based inverse analysis scheme is proposed to identify impact locations and reconstruct impact load time history of a simply supported plate through multiple levels of analysis. The proximity of the impact location is first determined by the triangulation method and the impact location is then refined by minimization of an objective function through the particle swarm optimization method (PSO). Loss of data due to filtration is addressed in a further level by performing an interval analysis based on extreme measurement errors. The outcome of the analyses is a mean impact location, a load time history, and a range of likely deviations. The extreme deviation in impact location is shown by bounding lines, which form a rectangle. The deviation in load time history is also shown by upper and lower bounding sinusoidal curves. The results of the analyses indicate that the proposed method can effectively locate the impact point and reconstruct the load time history even with the existence of noise in the measured response.
Bounding flow and transport analysis of proposed 105A mock-up tank tracer test
International Nuclear Information System (INIS)
The purpose of this bounding analysis was to determine bounding estimates of salt concentrations in the aquifer below the salt-tracer plume test at the 105A mockup-tank site near the inactive Semi-Works Plant in the 200 East Area. The objective was to calculate the bounding salt concentrations and compare them to the appropriate maximum contamination level (MCL) allowed by state law, which for sodium chloride is 415 mg/l as a secondary standard. The tracer test is part of the Electrical-Resistance Tomography (ERT) demonstration, which will provide an effective method of detecting tank leaks if it is shown to be successful. The basic idea of ERT method is that the electrical resistance in the soils will change enough to be detected when water with salts infiltrate the soils, even if a high-conductance metal tank is just above the leak. The 105A mockup tank did not have an impermeable bottom and was open at the top until the time of the test. It was assumed, at the time of the tracer test or shortly afterwards, that an impermeable bottom (concrete) would be placed at the bottom of the tank, but still remain open at the top. Hence, in this analysis, no artificial recharge is produced due to water running off a tank top, since no top is assumed. The conceptual model is discussed in Section 2.0 with the mathematical and numerical models briefly discussed in Section 3.0. The main results are given in Section 4.0 with the conclusions drawn in Section 5.0. These calculations were made before the tracer test. A similar set of calculations will be performed after the tracer test assuming more details concerning leak location and soil properties are available. The tracer test could be used to validate or confirm the modeling methodology/capability of plumes in the vadose zone at the Hanford site
Brustein, Ram
2000-01-01
The identification of a causal-connection scale motivates us to propose a new covariant bound on entropy within a generic space-like region. This "causal entropy bound", scaling as the square root of EV, and thus lying around the geometric mean of Bekenstein's S/ER and holographic S/A bounds, is checked in various "critical" situations. In the case of limited gravity, Bekenstein's bound is the strongest while naive holography is the weakest. In the case of strong gravity, our bound and Bousso's holographic bound are stronger than Bekenstein's, while naive holography is too tight, and hence typically wrong.
Variance bounding Markov chains
Roberts, Gareth O.; Jeffrey S. Rosenthal
2008-01-01
We introduce a new property of Markov chains, called variance bounding. We prove that, for reversible chains at least, variance bounding is weaker than, but closely related to, geometric ergodicity. Furthermore, variance bounding is equivalent to the existence of usual central limit theorems for all L2 functionals. Also, variance bounding (unlike geometric ergodicity) is preserved under the Peskun order. We close with some applications to Metropolis–Hastings algorithms.
Brustein, R; Veneziano, G
1999-01-01
The identification of a causal-connection scale motivates us to propose a new covariant bound on entropy within a generic space-like region. This "causal entropy bound", scaling as the square root of EV, and thus lying around the geometric mean of Bekenstein's S/ER and holographic S/A bounds, is checked in various "critical" situations. In the case of limited gravity, Bekenstein's bound is the strongest while naive holography is the weakest. In the case of strong gravity, our bound and Bousso...
Fractal dimension-bound spatio-temporal analysis of digital mammograms
Shanmugavadivu, P.; Sivakumar, V.; Sudhir, Rashmi
2016-02-01
A new Fractal Dimension-based diagnosis technique for the change detection and time-series analysis of masses in the temporal digital mammogram is presented in this paper. As the digital mammograms are confirmed as a reliable source for the prognosis of breast cancer, the demand for the development of precise computer aided detection techniques is constantly on the increase. This formed the basis for the development of this method using Fractal geometry, which is an efficient mathematical approach that deals with self-similar and irregular geometric objects called fractals. This work comprises of the detection of spatial masses using Fractal Hurst bound enhancement and segmentation of those temporal masses using Fractal Thresholding. The consultant radiologist's assessment of mass lesions forms the baseline for comparison and validation of the detected masses. Further, this research work performs temporal analysis of mass lesions, detected from the mammograms of the current and the respective prior view using the principle of Fractal Dimension. The precision of Fractal-dimension based temporal texture analysis of malignant masses of digital mammograms subsequently attributes to their characterization.
Energy Technology Data Exchange (ETDEWEB)
Grcar, Joseph F.
2002-02-04
A matrix lower bound is defined that generalizes ideas apparently due to S. Banach and J. von Neumann. The matrix lower bound has a natural interpretation in functional analysis, and it satisfies many of the properties that von Neumann stated for it in a restricted case. Applications for the matrix lower bound are demonstrated in several areas. In linear algebra, the matrix lower bound of a full rank matrix equals the distance to the set of rank-deficient matrices. In numerical analysis, the ratio of the matrix norm to the matrix lower bound is a condition number for all consistent systems of linear equations. In optimization theory, the matrix lower bound suggests an identity for a class of min-max problems. In real analysis, a recursive construction that depends on the matrix lower bound shows that the level sets of continuously differential functions lie asymptotically near those of their tangents.
Concept analysis: Some limitations and possible solutions
Botes, A.
2002-01-01
Concepts are the basic building blocks of scientific knowledge or theoretical frameworks for any discipline. The strength of the theories that guide a discipline is dependent on the quality of the concept analysis. Thus, the utilisation of poorly understood concepts in research and theory development will result in questionable reliability and validity. Concept analysis is associated with the research design of philosophical inquiry. The purpose of philosophical inquiry is to perform research...
Energy Technology Data Exchange (ETDEWEB)
Nichols, D.F.
1994-09-01
A detailed collisionless sheath theory and a three-region collisional model of a bounded plasma are presented, and the suitability of the collisional model for analysis of ignited mode thermionic converters is investigated. The sheath theory extends previous analyses to regimes in which the sheath potential and electron temperatures are comparable in magnitude. In all operating regimes typical of a ignited mode thermionic converter, the predicted sheaths extend several mean-free paths. The apparent collisionality of the sheaths prompted development of a collisional, three-region model of the converter plasma. By interfacing Particle-in-Cell regions (for the sheaths) and fluid regions (for the bulk of the plasma), a time-dependent, wall-to-wall model of the plasma in the inter-electrode space is created. The components of the model are tested and validated against analytic solutions and against one another, then applied to the analysis of an ignited mode thermionic converter. Under ignited mode operating conditions, the electron velocity distribution at the plasma/sheath boundary is found to be inconsistent with that assumed in the model development, and the calculation diverges. The observed distribution is analyzed and a new basis set of distribution functions is suggested that should permit application of the hybrid model to ignited mode thermionic converters.
Shotgun approaches to gait analysis: insights & limitations
Kaptein, Ronald G; Wezenberg, Daphne; IJmker, Trienke; Houdijk, Han; Beek, Peter J; Lamoth, Claudine J. C.; Daffertshofer, Andreas
2014-01-01
Background: Identifying features for gait classification is a formidable problem. The number of candidate measures is legion. This calls for proper, objective criteria when ranking their relevance. Methods: Following a shotgun approach we determined a plenitude of kinematic and physiological gait measures and ranked their relevance using conventional analysis of variance (ANOVA) supplemented by logistic and partial least squares (PLS) regressions. We illustrated this approach using data from ...
Bousso, Raphael
2016-01-01
We show that known entropy bounds constrain the information carried off by radiation to null infinity. We consider distant, planar null hypersurfaces in asymptotically flat spacetime. Their focussing and area loss can be computed perturbatively on a Minkowski background, yielding entropy bounds in terms of the energy flux of the outgoing radiation. In the asymptotic limit, we obtain boundary versions of the Quantum Null Energy Condition, of the Generalized Second Law, and of the Quantum Bousso Bound.
Saric, Dragomir
2006-01-01
We give a short proof of the fact that bounded earthquakes of the unit disk induce quasisymmetric maps of the unit circle. By a similar method, we show that symmetric maps are induced by bounded earthquakes with asymptotically trivial measures.
Detection limits in x-ray fluorescence analysis
International Nuclear Information System (INIS)
X-ray fluorescence spectrometry is a well established analytical technique for elemental analysis of solids, powders, or liquids. This extended abstract briefly discusses the detection limits or sensitivity of x-ray spectrometers in x-ray fluorescence analysis
Scaling Limit Analysis of Borromean Halos
Souza, L. A.; Bellotti, F. F.; Frederico, T.; Yamashita, M. T.; Tomio, Lauro
2016-05-01
The analysis of the core recoil momentum distribution of neutron-rich isotopes of light exotic nuclei is performed within a model of halo nuclei described by a core and two neutrons dominated by the s-wave channel. We adopt the renormalized three-body model with a zero-range force, which accounts for the Efimov physics. This model is applicable to nuclei with large two-neutron halos compared to the core size, and a neutron-core scattering length larger than the interaction range. The halo wave function in momentum space is obtained by using as inputs the two-neutron separation energy and the energies of the singlet neutron-neutron and neutron-core virtual states. Within our model, we obtain the momentum probability densities for the Borromean exotic nuclei Lithium-11 (^{11}Li), Berylium-14 (^{14}Be) and Carbon-22 (^{22}C). A fair reproduction of the experimental data was obtained in the case of the core recoil momentum distribution of ^{11}Li and ^{14}Be, without free parameters. By extending the model to ^{22}C, the combined analysis of the core momentum distribution and matter radius suggest (i) a ^{21}C virtual state well below 1 MeV; (ii) an overestimation of the extracted matter ^{22}C radius; and (iii) a two-neutron separation energy between 100 and 400 keV.
International Nuclear Information System (INIS)
The analytical method for organically bound tritium (OBT) was developed in our laboratory. The optimized operating conditions and parameters were established for sample drying, special combustion, distillation, and measurement on a liquid scintillation spectrometer (LSC). Selected types of OBT samples such as rice, corn, rapeseed, fresh lettuce and pork were analyzed for method validation of recovery rate reproducibility, the minimum detection concentration, and the uncertainty for typical low level environmental sample was evaluated. The combustion water recovery rate of different dried environmental sample was kept at about 80%, the minimum detection concentration of OBT ranged from 0.61 to 0.89 Bq/kg (dry weight), depending on the hydrogen content. It showed that this method is suitable for OBT analysis of environmental sample with stable recovery rate, and the combustion water yield of a sample with weight about 40 g would provide sufficient quantity for measurement on LSC. - Highlights: • The design of a combustion furnace for OBT sample preparation and the optimized parameters were introduced. • The uncertainty of the OBT measurement was assessed. • The method was validated to be suitable for OBT measurement of environmental samples
Quantitative Risk Analysis of Obstacle Limitation Standards
Sandaradura, Amila Silva
Obstacle limitation surfaces (OLS) are the main safeguard against objects that can pose a hazard to aircraft operations at and around the airports. The standard dimensions of the most of these surfaces were estimated using the pilot's experience at the time when they were included in to the standard documents. As a result, some of these standards may have been overestimated while others may not provide an adequate level of safety. With airports moving to the Safety Management System (SMS) approach to design and operations safety, proper evaluation of the level of safety provided by OLS at specific sites becomes great importance to airport operators. There is no published evidence, however, for the estimation of the safety level provided by the existing OLS standards. Moreover, the rationale used by the ICAO to establish existing OLS standards is not readily available in the standard documents. Therefore this study attempts to collect actual flight path data using information provided by air traffic control radars and construct a methodology to assess the probability of aircraft deviating from their intended/protected path. The extension of the developed methodology can be used to estimate the OLS dimensions that provide an acceptable safety level for the aircraft operations. This will be helpful to estimate safe and efficient standard dimensions of the OLS and assess the risk level of objects to the aircraft operations around airports. In order to assess the existing standards and show the applications of the methodology, three case studies were conducted using aircraft data collected from Ottawa (CYOW), Calgary (CYYC) and Edmonton (CYEG) International Airports.
Scaling limit analysis of Borromean halos
Souza, L A; Frederico, T; Yamashita, M T; Tomio, L
2016-01-01
The analysis of the core recoil momentum distribution of neutron-rich isotopes of light exotic nuclei is performed within a model of the halo nuclei described by a core and two neutrons dominated by the $s-$wave channel. We adopt the renormalized three-body model with a zero-range force, that accounts for the universal Efimov physics. This model is applicable to nuclei with large two-neutron halos compared to the core size, and a neutron-core scattering length larger than the interaction range. The halo wave function in momentum space is obtained by using as inputs the two-neutron separation energy and the energies of the singlet neutron-neutron and neutron-core virtual states. Within our model, we obtain the momentum probability densities for the Borromean exotic nuclei Lithium-11 ($^{11}$Li), Berylium-14 ($^{14}$Be) and Carbon-22 ($^{22}$C). A fair reproduction of the experimental data was obtained in the case of the core recoil momentum distribution of $^{11}$Li and $^{14}$Be, without free parameters. By e...
A Case Study of Chinese Bound Feet: Application of Footprint Analysis
Reischl, Uwe; Nandikolla, Vidja; Colby, Conrad; Mijović, Budimir; Wei, Hsian-Chuen
2008-01-01
Foot print patterns of the bound feet of a 90-year-old Chinese female were made to obtain insight into the ergonomic consequences of a Chinese custom that caused significant disabilities for many women throughout history. Pressure patterns were evaluated using the techniques applied to standard thumb print analsyis. A digital summary of the pressure patterns were compared to the patterns obtained from a normal subject. The outcomes indicated that the bound foot produced greater pl...
Mendez, Rene A; Orsotica, Rodrigo; Lobos, Rodrigo
2014-01-01
In this paper we use the Cramer-Rao lower uncertainty bound to estimate the maximum precision that could be achieved on the joint simultaneous (or 2D) estimation of photometry and astrometry of a point source measured by a linear CCD detector array. We develop exact expressions for the Fisher matrix elements required to compute the Cramer-Rao bound in the case of a source with a Gaussian light profile. From these expressions we predict the behavior of the Cramer-Rao astrometric and photometric precision as a function of the signal and the noise of the observations, and compare them to actual observations - finding a good correspondence between them. We show that the astrometric Cramer-Rao bound goes as $(S/N)^{-1}$ (similar to the photometric bound) but, additionally, we find that this bound is quite sensitive to the value of the background - suppressing the background can greatly enhance the astrometric accuracy. We present a systematic analysis of the elements of the Fisher matrix in the case when the detec...
Physical Uncertainty Bounds (PUB)
Energy Technology Data Exchange (ETDEWEB)
Vaughan, Diane Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Dean L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-03-19
This paper introduces and motivates the need for a new methodology for determining upper bounds on the uncertainties in simulations of engineered systems due to limited fidelity in the composite continuum-level physics models needed to simulate the systems. We show that traditional uncertainty quantification methods provide, at best, a lower bound on this uncertainty. We propose to obtain bounds on the simulation uncertainties by first determining bounds on the physical quantities or processes relevant to system performance. By bounding these physics processes, as opposed to carrying out statistical analyses of the parameter sets of specific physics models or simply switching out the available physics models, one can obtain upper bounds on the uncertainties in simulated quantities of interest.
土石坝坡极限抗震能力的下限有限元法%Lower bound FEM for limit aseismic capability of earth-rockfill dams
Institute of Scientific and Technical Information of China (English)
杨昕光; 迟世春
2013-01-01
基于极限分析下限定理,假设材料严格服从Mohr-Coulomb屈服准则,同时考虑了堆石料内摩擦角较大以及抗剪强度具有非线性的特性,提出了一个用于求解土石坝坝坡极限抗震能力的有限元计算方法.该方法通过静力平衡条件、应力间断面连续条件、边界条件、屈服条件以及所求极限荷载,形成标准的二次锥规划数学模型,并用内点法进行优化迭代求解,得到土石坝坡极限抗震能力的下限值.对一条形基础地基承载力进行下限极限分析,通过与已有计算结果比较表明所提方法的具有很高的计算精度.运用所提方法对一典型心墙土石坝进行抗震极限分析,其计算结果符合土石坝坡在地震作用下的一般破坏规律,证明此方法具有很高的实用价值.%An FEM basea on the lower bound theorem of limit analysis is proposed to study the limit aseismic capability of earth-rock-fill dams.Considering the large internal friction angel and non-linear shear strength parameters of rockfill materials,the proposed method formulates the limit analysis as a second-order cone programming (SOCP) problem with constraints based on the conditions of equilibrium,stress discontinuity,stress boundary and native Mohr-Coulomb yield criterion.The lower bound of the limit aseismic capability is then obtained by means of the interior-point algorithm and the iterative approach.Comparison with the published solutions illustrates the correctness and effectiveness of the proposed method for a smooth strip footing problem.The proposed approach is also applied to the seismic stability analysis of a typical rockfill dam with core wall so that the limit aseismic capability of the dam is obtained.The results proclaim the seismic failure mechanisms of earth-rockfill dams and demonstrate the practical value of the proposed method.
From the Deuteron to Deusons, an Analysis of Deuteronlike Meson-Meson Bound States
Törnqvist, N A
1994-01-01
A systematic study of possible deuteronlike two-meson bound states, {\\it deusons}, is presented. Previous arguments that many such bound states may exist are elaborated with detailed arguments and numerical calculations including, in particular, the tensor potential. In the heavy meson sector one-pion exchange alone is strong enough to form at least deuteron-like $B\\bar B^*$ and $B^*\\bar B^*$ composites bound by approximately 50 MeV. Composites of $D\\bar D^*$ and $D^*\\bar D^*$ states bound by pion exchange alone are expected near the thresholds, while in the light meson sector one generally needs some additional short range attraction to form bound states. The quantum numbers of these states are I=0, In $B\\bar B^*$ one predictss the states: $\\eta_b(\\approx 10545),\\ \\chi_{b1}(\\approx 10562)$, and in $B^*\\bar B^*$ one finds the states: $\\eta_b(\\approx 10590),\\ \\chi_{b0}(\\approx 10582),\\ h_b(\\approx 10608),\\ \\chi_{b2}(\\approx 10602)$. Near the $D\\bar D^*$ threshold the states: $\\eta_c(\\approx 3870),\\ \\chi_{c0}(\\...
Limit analysis assessment of experimental behavior of arches reinforced with GFRP materials
Basilio, Ismael; Fedele, Roberto; Lourenço, Paulo B.; Milani, Gabriele
2014-10-01
In this paper, a comparison between results furnished by a 3D FE upper bound limit analysis and experimental results for some reinforced masonry arches tested at the University of Minho (Portugal) is provided. While the delamination from arches support can be modelled only in an approximate way within limit analysis, the aim of the paper is to accurately reproduce the change in the failure mechanism observed in experimentation, due to the introduction of strengthening elements. Both experimental and numerical results showa clear change in the failure mechanism and in the corresponding ultimate peak load. A set of simulations is also performed on reinforced arches previously damaged, to investigate the role played by the reinforcement within a proper repairing procedure. Good correlation with experimental work and numerical simulations is achieved.
Detection limits for Gamma-Ray spectral analysis
International Nuclear Information System (INIS)
This paper presents a study concerning the formulation of sensitivity limits in radioactivity analysis using gamma-ray spectrometer. Expressions for practical evaluation of the detection level (SD) and the detection limit (LD) are given. The detection level is defined as a detection criterion (a posteriori) and the detection limit is defined either a posteriori, for undetected radionuclides, or a priori, for the weakest activity which can be detected in the analysis conditions. Given expressions use only the total background at the place of gamma-ray photopeak and the Full Width at Half Maximum (FWHM) for this peak. The main parameters occurring in these limits are studied and some recommendations are given. The use of these limits in some expressions of radioactivity analysis results (single measure, sum, mean) is also indicated
Slope Stability Analysis Using Limit Equilibrium Method in Nonlinear Criterion
Hang Lin; Wenwen Zhong; Wei Xiong; Wenyu Tang
2014-01-01
In slope stability analysis, the limit equilibrium method is usually used to calculate the safety factor of slope based on Mohr-Coulomb criterion. However, Mohr-Coulomb criterion is restricted to the description of rock mass. To overcome its shortcomings, this paper combined Hoek-Brown criterion and limit equilibrium method and proposed an equation for calculating the safety factor of slope with limit equilibrium method in Hoek-Brown criterion through equivalent cohesive strength and the fric...
Stability bound analysis of singularly perturbed systems with time-delay
Directory of Open Access Journals (Sweden)
Sun Fengqi
2013-01-01
Full Text Available This paper considers the stability bound problem of singularly perturbed systems with time-delay. Some stability criteria are derived by constructing appropriate Lyapunov-Krasovskii functionals. The proposed criteria are less conservative than the existing ones. Two numerical examples are given to illustrate the advantages and effectiveness of the proposed methods.
International Nuclear Information System (INIS)
Within the last ten years there has been increasing interest in tritium behaviour and distribution in the environment. This is based partly on empirical findings that tritium discharged mostly as HTO can become transformed into organic forms in environmental samples. An international workshop was convened in France in 2012 to gather the scientific community interested in organically bound tritium to share their experience and to establish a current state of knowledge. This paper summarises the outcome of the workshop, which aimed to improve skills concerning OBT (Organically Bound Tritium) determination, transfer and behaviour in the environment. In order to improve OBT measurement credibility, it was decided to conduct and promote OBT analysis through inter-laboratory exercises. This practice will reduce uncertainty in OBT analysis results, providing better OBT model validation data and public dose assessments. (authors)
Czech Academy of Sciences Publication Activity Database
Koldovský, Zbyněk; Tichavský, Petr; Oja, E.
2006-01-01
Roč. 17, č. 5 (2006), s. 1265-1277. ISSN 1045-9227 R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : Independent component analysis * blind source separation * blind deconvolution * Cramer-Rao lower bound * algorithm FastICA Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.620, year: 2006
Bound states and the Bekenstein bound
Bousso, R
2004-01-01
We explore the validity of the generalized Bekenstein bound, S <= pi M a. We define the entropy S as the logarithm of the number of states which have energy eigenvalue below M and are localized to a flat space region of width a. If boundary conditions that localize field modes are imposed by fiat, then the bound encounters well-known difficulties with negative Casimir energy and large species number, as well as novel problems arising only in the generalized form. In realistic systems, however, finite-size effects contribute additional energy. We study two different models for estimating such contributions. Our analysis suggests that the bound is both valid and nontrivial if interactions are properly included, so that the entropy S counts the bound states of interacting fields.
Methods of fault tree analysis and their limits
International Nuclear Information System (INIS)
Some recent methodological developments of fault tree analysis are discussed and limits of fault tree analysis and a criterion for admissibility of structure functions are given. It is shown that there are interesting relations to switching theory and to stochastic processes. (orig./HP)
Stability analysis in a Cournot duopoly with managerial sales delegation and bounded rationality
Fanti, Luciano; Gori, Luca
2011-01-01
The present study analyses the dynamics of a Cournot duopoly with managerial sales delegation and bounded rational players. We find that when firms’ owners hire a manager and delegate the output decisions to him, the unique Cournot-Nash equilibrium is more likely to be destabilised (through a flip bifurcation) than when firms maximise profits. Moreover, highly periodicity and deterministic chaos can also occur as the managers’ bonus increases.
Proteomic Analysis to Identify Tightly-Bound Cell Wall Protein in Rice Calli
Cho, Won Kyong; Hyun, Tae Kyung; Kumar, Dhinesh; Rim, Yeonggil; Chen, Xiong Yan; Jo, Yeonhwa; Kim, Suwha; Lee, Keun Woo; Park, Zee-Yong; Lucas, William J.; Kim, Jae-Yean
2015-01-01
Rice is a model plant widely used for basic and applied research programs. Plant cell wall proteins play key roles in a broad range of biological processes. However, presently, knowledge on the rice cell wall proteome is rudimentary in nature. In the present study, the tightly-bound cell wall proteome of rice callus cultured cells using sequential extraction protocols was developed using mass spectrometry and bioinformatics methods, leading to the identification of 1568 candidate proteins. Ba...
Seadrill : valuation and financial statement analysis of Seadrill limited
Uggedal, Kim André
2009-01-01
This paper takes on the valuation of the drilling operator Seadrill Limited. The valuation takes basis in strategic analysis and financial statement analysis. The paper has the perspective of a global well-diversified investor. The strategic analysis concludes that Seadrill has the highest industry exposure to the very favourable UDW segment, and is well positioned for further growth. Discounted cash flow model (DCF) has been used as main valuation approach, with focus on th...
International Nuclear Information System (INIS)
Nuclear forces play a decisive role to account for the evolution of the nuclear structure and to fix the limits of particle stability. The study of neutron-rich nuclei is particularly important to determine these limits and to reveal the disappearance or emergence of new shell gaps far from stability. We studied the weakly bound neutron-rich 26F in order to probe the πd5/2xνd3/2 interaction. Indeed this nucleus can be modeled as a closed core of 24O on top of which a single deeply bound proton in πd5/2 interacts with an unbound neutron in νd3/2. This coupling gives rise to the quadruplet of states J = 1, 2, 3, 4 of positive parity. Their determination would allow us to quantify the intensity of the πd5/2xνd3/2 interaction. Among these states, the J = 1 (ground state) and J = 2 (first excited state) were already known. The search for the J = 4 state has been investigated by our group at GANIL through a β-decay experiment. The nuclei of 26F were produced by the fragmentation of a 36S beam and selected using the LISE spectrometer. They were then implanted in a Double Sided Stripped Silicon Detector that gave us the opportunity to achieve spatial and time correlations between the implanted ions and the products of the decays (β and γ rays). Moreover we were able to observe the delayed M3 γ transition from the isomeric J = 4 state to the J = 1 ground state and thus obtained the excitation energy of 643.4 keV for this isomeric state. We also determined several new states in 25-26Ne that were fed by the β-decay of the ground and isomeric state of 26F. We extracted an isomeric ratio of about 40% and adjusted the previously determined mass of 26F according to this value, leading to ΔM = 270 (50) keV. The J = 3 state has been populated ad studied at GSI by means of a one proton knock-out reaction from a radioactive 27Ne beam to produce the 26F in its unbound states. When the 26F is produced in its unbound state J = 3, it decays in 25F + n. The ions were tracked
Gutiérrez-Rodríguez, A
2003-01-01
A bound on the nu /sup tau / magnetic moment is calculated through the reaction e/sup +/e/sup -/ to nu nu gamma at the Z/sub 1/-pole, and in the framework of a left-right symmetric model at LEP energies. We find that the bound is almost independent of the mixing angle phi of the model in the allowed experimental range for this parameter. (31 refs).
Macro economic analysis of CO2 emission limits for China
International Nuclear Information System (INIS)
Using a newly developed time-recursive dynamic CGE model for energy and environmental policy analysis of the Chinese economy, a business-as-usual scenario is first developed assuming no specific policy intervention to limit the growth rate of CO2 emissions. Counter factual policy simulation is then carried out to compute the macroeconomic implications of a carbon tax to limit the Chinese energy-related CO2 emissions. 2 tabs., 5 refs
Relationship Network Analysis of Manufacturing System Limited by Business Lines
Chen, Guorong; Yan, Ping; SHI Jinliang; DENG Juli
2012-01-01
It is a common problem of manufacturing enterprise limited by business line, which optimized its resources allocation to increase productivity, but now the researches are very weak in relationship mapping and network analysis method in the world. Aimed to the demands, proposed a resource allocation method limited by business line of manufacturing system based on the relational mapping of production system, manufacturing model of hierarchical network based on business line and node degree...
International Nuclear Information System (INIS)
The In-Tank Precipitation process (ITP) receives High Level Waste (HLW) supernatant liquid containing radionuclides in waste processing tank 48H. Sodium tetraphenylborate, NaTPB, and monosodium titanate (MST), NaTi2O5H, are added for removal of radioactive Cs and Sr, respectively. In addition to removal of radio-strontium, MST will also remove plutonium and uranium. The majority of the feed solutions to ITP will come from the dissolution of supernate that had been concentrated by evaporation to a crystallized salt form, commonly referred to as saltcake. The concern for criticality safety arises from the adsorption of U and Pt onto MST. If sufficient mass and optimum conditions are achieved then criticality is credible. The concentration of u and Pt from solution into the smaller volume of precipitate represents a concern for criticality. This report supplements WSRC-TR-93-171, Nuclear Criticality Safety Bounding Analysis For The In-Tank-Precipitation (ITP) Process. Criticality safety in ITP can be analyzed by two bounding conditions: (1) the minimum safe ratio of MST to fissionable material and (2) the maximum fissionable material adsorption capacity of the MST. Calculations have provided the first bounding condition and experimental analysis has established the second. This report combines these conditions with canyon facility data to evaluate the potential for criticality in the ITP process due to the adsorption of the fissionable material from solution. In addition, this report analyzes the potential impact of increased U loading onto MST. Results of this analysis demonstrate a greater safety margin for ITP operations than the previous analysis. This report further demonstrates that the potential for criticality in the ITP process due to adsorption of fissionable material by MST is not credible
Time series analysis in astronomy: Limits and potentialities
DEFF Research Database (Denmark)
Vio, R.; Kristensen, N.R.; Madsen, Henrik;
2005-01-01
In this paper we consider the problem of the limits concerning the physical information that can be extracted from the analysis of one or more time series ( light curves) typical of astrophysical objects. On the basis of theoretical considerations and numerical simulations, we show that with no a...
An energetic view on the limit analysis of normal bodies
Czech Academy of Sciences Publication Activity Database
Lucchesi, M.; Padovani, C.; Šilhavý, Miroslav
2010-01-01
Roč. 68, č. 4 (2010), s. 713-746. ISSN 0033-569X Institutional research plan: CEZ:AV0Z10190503 Keywords : collapse * limit analysis * minimum energy Subject RIV: BA - General Mathematics Impact factor: 0.697, year: 2010 http://www.ams.org/journals/qam/2010-68-04/S0033-569X-2010-01182-2/
Model-independent analysis of B → π K decays and bounds on the weak phase γ
International Nuclear Information System (INIS)
A general parametrization of the amplitudes for the rare two-body decays B → π K is introduced, which makes maximal use of theoretical constraints arising from flavour symmetries of the strong interactions and the structure of the low-energy effective weak Hamiltonian. With the help of this parametrization, a model-independent analysis of the branching ratios and direct CP asymmetries in the various B → π K decay modes is performed, and the impact of hadronic uncertainties on bounds on the weak phase γ = arg(Vub*) is investigated. (author)
Stochastic period-doubling bifurcation analysis of a Roessler system with a bounded random parameter
International Nuclear Information System (INIS)
This paper aims to study the stochastic period-doubling bifurcation of the three-dimensional Roessler system with an arch-like bounded random parameter. First, we transform the stochastic Roessler system into its equivalent deterministic one in the sense of minimal residual error by the Chebyshev polynomial approximation method. Then, we explore the dynamical behaviour of the stochastic Roessler system through its equivalent deterministic system by numerical simulations. The numerical results show that some stochastic period-doubling bifurcation, akin to the conventional one in the deterministic case, may also appear in the stochastic Roessler system. In addition, we also examine the influence of the random parameter intensity on bifurcation phenomena in the stochastic Roessler system. (general)
Performance analysis of parallel branch and bound search with the hypercube architecture
Mraz, Richard T.
1987-01-01
With the availability of commercial parallel computers, researchers are examining new classes of problems which might benefit from parallel computing. This paper presents results of an investigation of the class of search intensive problems. The specific problem discussed is the Least-Cost Branch and Bound search method of deadline job scheduling. The object-oriented design methodology was used to map the problem into a parallel solution. While the initial design was good for a prototype, the best performance resulted from fine-tuning the algorithm for a specific computer. The experiments analyze the computation time, the speed up over a VAX 11/785, and the load balance of the problem when using loosely coupled multiprocessor system based on the hypercube architecture.
Xie, Hang; Sha, Wei E I
2015-01-01
Numerical methods are developed in the quantum transport calculations for electron in the waveguides with spin-orbital (Rashba) interaction. The methods are based on a hybrid mode-matching scheme in which the wavefunctions are expressed as the superposition of eigenmodes in the lead regions and in the device region the wavefunction is expressed on the discrete basis. Two versions are presented for the lead without and with the Rashba interaction. In the latter case the eigenmodes are obtained from a quadratic eigenproblem calculation. These methods are suitable for the systems with variable geometries or arbitrary potential profiles. The computation can be effectively accelerated by the sparse matrix technique. We also investigate the Fano-Rashba bound states in the Rashba waveguides by some nonlinear eigenstate calculation. This calculation is based on a mode-matching method and self-consistent results are obtained in our calculations.
Breakdown voltage analysis of field limiting ring structure
International Nuclear Information System (INIS)
In this paper, a computer based analysis is performed to study the effect of floating field-limiting rings (FLR) on the breakdown voltage of Si microstrip detectors. For optimum performance it is crucial to achieve the maximum breakdown voltage for Si detectors operated at very high bias due to extremely hostile radiation environment of LHC. The breakdown performance of Si microstrip detectors can be improved by implementing floating field-limiting rings (FLR) around the active detector area. In the present work, we propose a criterion for optimising the spacing of FLR with respect to the main junction. (author)
Design, analysis, and testing of wood filled impact limiters
International Nuclear Information System (INIS)
In current practice, Type B packagings are generally provided with protective covers or impact limiters designed to protect the cask body during impact after the 30 foot free drop regulatory accident. Both the target and the typical shielded cask are essentially rigid. Therefore, the impact limiters must deform or crush in a precisely controlled manner to absorb the kinetic energy without producing excessive inertial loadings or contact forces on the cask body. Transnuclear has found wood to be an ideal energy absorption material for use in impact limiters. Wood has many properties that give it a distinct advantage over other materials. These advantages include: high energy absorption can be achieved per pound of material; large strain can be accommodated before material lockup; a wide selection of material properties is available in different woods; anisotropic behavior (i.e. the crush strength variation with load orientation relative to grain direction) can be used to advantage in local areas of the limiter; properties of wood can be verified before assembly into the limiter (rather than determined afterward as in the case of foam). This paper describes the design, analysis and testing approaches used to develop and verify the performance of wood filled impact limiters for several recent Transnuclear packaging
Analysis of a nonlinear mixed Cournot game with boundedly rational players
International Nuclear Information System (INIS)
Highlights: • A dynamic nonlinear mixed Cournot game with a semipublic firm and a private firm is developed. • The stability of the Nash equilibrium and complex dynamic features are discussed. • The production adjustment costs are proved to inhibit the stability of the Nash equilibrium sometimes. -- Abstract: In this paper, we consider a creative case where one semipublic firm endeavors to maximize the weighted average on social welfare and its own profit while the other private firm only intends to maximize its own profit, so we bring in a dynamic nonlinear mixed Cournot model with bounded rationality. The locally asymptotical stability of the unique Nash equilibrium is also investigated and complex dynamic features including period doubling bifurcations, strange attractors and chaotic phenomena are also discussed. Furthermore, by introducing production adjustment costs into the model, we will show that sometimes they violate the locally asymptotical stability of the Nash equilibrium, compared to the well-known results under the best response dynamic when these costs act as a stabilizing factor
International Nuclear Information System (INIS)
Electricity demand in South Africa has grown at a very rapid rate over the past decade. As part of reform initiatives to enhance long-term sustainability of the country's electricity industry, South Africa's authorities have in recent years sought to develop an electricity pricing framework that is cost reflective and forms the cornerstone of demand management schemes meant to foster changes in consumption behaviour and enhance efficiency in resource use. The effects of any pricing policy on aggregate electricity consumption will depend on a useful understanding of the factors that influence electricity demand, and the magnitude to which electricity demand responds to changes in such factors. In this context, this paper applies the bounds testing approach to cointegration within an autoregressive distributed lag framework to examine the aggregate demand for electricity in South Africa during the period 1960-2007. The results indicate that in the long run, income is the main determinant of electricity demand. With electricity prices having an insignificant effect on aggregate electricity demand, future pricing policies will need to ensure that electricity prices are cost reflective and enhance efficiency of electricity supply and use.
Purification and structural analysis of membrane-bound polyphenol oxidase from Fuji apple.
Liu, Fang; Zhao, Jin-Hong; Wen, Xin; Ni, Yuan-Ying
2015-09-15
Membrane-bound polyphenol oxidase (mPPO) in Fuji apple (Malus domestica Borkh. cv. Red Fuji) was purified and analyzed with a nanoelectrospray ionization mass spectrometer. The three-dimensional model and binding site of mPPO to 4-methyl catechol were also studied using molecular docking. mPPO was purified 54.41-fold using temperature-induced phase partitioning technique and ion exchange chromatography. mPPO had a molecular weight of 67.3kDa. Even though a significant level of homology was observed between mPPO and the soluble polyphenol oxidase in the copper binding sequence, there was another region, rich in histidine residues, which differed in 13 amino acids. The three-dimensional structure of mPPO consisted of six α-helices, two short β-strands, and ten random coils. The putative substrate-binding pocket contained six polar or charged amino acids, His191, His221, Trp224, Trp228, Phe227, and Val190. Trp224 and Trp228 formed hydrogen bonds with 4-methyl-catechol. PMID:25863612
DEFF Research Database (Denmark)
Forchhammer, Søren
2004-01-01
A method for designing quasistationary probability measures for two-dimensional (2-D) constraints is presented. This measure is derived from a modified bit-stuff coding scheme and it gives the capacity of the coding scheme. This provides a constructive lower bound on the capacity of the 2-D...... constraint. The main examples are checkerboard codes with binary elements. The capacity for one instance of the modified bit-stuffing for the 2-D runlength-limited RLL(2,∞) constraint is calculated to be 0.4414 bits/symbol. For the constraint given by a minimum (1-norm) distance of 3 between 1s a code with...... capacity 0.3497 bits/symbol is given....
Relationship Network Analysis of Manufacturing System Limited by Business Lines
Directory of Open Access Journals (Sweden)
CHEN Guorong
2012-10-01
Full Text Available It is a common problem of manufacturing enterprise limited by business line, which optimized its resources allocation to increase productivity, but now the researches are very weak in relationship mapping and network analysis method in the world. Aimed to the demands, proposed a resource allocation method limited by business line of manufacturing system based on the relational mapping of production system, manufacturing model of hierarchical network based on business line and node degree are been established. Defined the data structure of node on hierarchical network, simplified the network computing by dividing it to three parts - orders assignment, accomplish feedback and pure information exchange. Analyzed the distributing of network degree, established an equation of power law which has two limited parameters of node degree and side weight to automatic compute the amounts of resources of new order. Case study shows that the network analysis method limited business line proposed in the paper can give us an important reference frame of resources assignment.
Time series analysis in astronomy: Limits and potentialities
DEFF Research Database (Denmark)
Vio, R.; Kristensen, N.R.; Madsen, Henrik; Wamsteker, W.
2005-01-01
priori physical model there are not many possibilities to obtain interpretable results. For this reason, the practice to develop more and more sophisticated statistical methods of time series analysis is not productive. Only techniques of data analysis developed in a specific physical context can be......In this paper we consider the problem of the limits concerning the physical information that can be extracted from the analysis of one or more time series ( light curves) typical of astrophysical objects. On the basis of theoretical considerations and numerical simulations, we show that with no a...... expected to provide useful results. The field of stochastic dynamics appears to be an interesting framework for such an approach. In particular, it is shown that modelling the experimental time series by means of the stochastic differential equations (SDE) represents a valuable tool of analysis. For...
Limit analysis on FRP-strengthened RC members
D. De Domenico; A.A.Pisano; P. Fuschi
2014-01-01
Reinforced concrete (RC) members strengthened with externally bonded fiber-reinforced-polymer (FRP) plates are numerically investigated by a plasticity-based limit analysis approach. The key-concept of the present approach is to adopt proper constitutive models for concrete, steel reinforcement bars (re-bars) and FRP strengthening plates according to a multi-yield-criteria formulation. This allows the prediction of concrete crushing, steel bars yielding and FRP rupture that may oc...
Limits of detection in instrumental neutron activation analysis
International Nuclear Information System (INIS)
Lower limits of detection (LLODs), frequently referred to simply as limits of detection and abbreviated as LODs, often appear in the literature of analytical chemistry - for numerous different methods of elemental and/or molecular analysis. In this chapter, one particular method of quantitative elemental analysis, that of instrumental neutron activation analysis (INAA), is the subject discussed, with reference to LODs. Particularly in the literature of neutron activation analysis (NAA), many tables of 'interference-free' NAA LODs are available. Not all of these are of much use, because (1) for many the definition used for LOD is not clear, or reasonable, (2) for many, the analysis conditions used are not clearly specified, and (3) for many, the analysis conditions used are specified, but not very practicable for most laboratories. For NAA work, such tables of interference-free LODs are, in any case, only applicable to samples in which, at the time of counting, only one radionuclide is present to any significant extent in the activated sample. It is important to note that tables of INAA LODs, per se, do not exist - since the LOD for a given element, under stated analysis conditions, can vary by orders of magnitude, depending on the elemental composition of the matrix in which it is present. For any given element, its INAA LOD will always be as large as, and usually much larger than, its tabulated 'interference-free' NAA LOD - how much larger depending upon the elemental composition of the matrix in which it is present. As discussed in this chapter, however, an INAA computer program exists that can calculate realistic INAA LODs for any elements of interest, in any kind of specified sample matrix, under any given set of analysis conditions
TFCX pumped limiter and vacuum pumping system design and analysis
International Nuclear Information System (INIS)
Impurity control system design and performance studies were performed in support of the Tokamak Fusion Core Experiment (TFCX) pre-conceptual design. Efforts concentrated on pumped limiter and vacuum pumping system design configuration, thermal/mechanical and erosion lifetime performance of the limiter protective surface, and helium ash removal performance. The reference limiter design forms a continuous toroidal belt at the bottom of the device and features a flat surface with a single leading edge. The vacuum pumping system features large vacuum ducts (diameter approximately 1 m) and high-speed, compound cryopumps. Analysis results indicate that the limiter/vacuum pumping system design provides adequate helium ash removal. Erosion, primarily by disruption-induced vaporization and/or melting, limits the protective surface lifetime to about one calendar year or only about 60 full-power hours of operation. In addition to evaluating impurity control system performance for nominal TFCX conditions, these studies attempt to focus on the key plasma physics and engineering design issues that should be addressed in future research and development programs
Information bounds for Gaussian copulas
Hoff, Peter D; Wellner, Jon A
2011-01-01
Often of primary interest in the analysis of multivariate data are the copula parameters describing the dependence among the variables, rather than the univariate marginal distributions. Since the ranks of a multivariate dataset are invariant to changes in the univariate marginal distributions, rank-based procedures are natural candidates as semiparametric estimators of copula parameters. Asymptotic information bounds for such estimators can be obtained from an asymptotic analysis of the rank likelihood, i.e. the probability of the multivariate ranks. In this article, we obtain limiting normal distributions of the rank likelihood for Gaussian copula models. Our results cover models with structured correlation matrices, such as exchangeable, autoregressive and circular correlation, as well as unstructured correlation matrices. For all Gaussian copula models, the limiting distribution of the rank likelihood ratio is shown to be equal to that of a parametric likelihood ratio for an appropriately chosen multivari...
Cramér-Rao lower bound analysis for guidance systems with bearings-only measurements
Institute of Scientific and Technical Information of China (English)
ZHANG Yong-an; ZHOU Di; DUAN Guang-ren
2007-01-01
Most currently existing investigations on the observability of passive guidance systems can only protimability analysis of closed-loop guidance systems with bearings-only measurements, is proposed. The new method provides an intuitive result for observability of the guidance system through graphical analysis. As a demonstration, a numerical example is presented, in which the degrees of observability of the guidance systems under two commonly used guidance laws are compared by using the new approach.
Current parallel I/O limitations to scalable data analysis.
Energy Technology Data Exchange (ETDEWEB)
Mascarenhas, Ajith Arthur; Pebay, Philippe Pierre
2011-07-01
This report describes the limitations to parallel scalability which we have encountered when applying our otherwise optimally scalable parallel statistical analysis tool kit to large data sets distributed across the parallel file system of the current premier DOE computational facility. This report describes our study to evaluate the effect of parallel I/O on the overall scalability of a parallel data analysis pipeline using our scalable parallel statistics tool kit [PTBM11]. In this goal, we tested it using the Jaguar-pf DOE/ORNL peta-scale platform on a large combustion simulation data under a variety of process counts and domain decompositions scenarios. In this report we have recalled the foundations of the parallel statistical analysis tool kit which we have designed and implemented, with the specific double intent of reproducing typical data analysis workflows, and achieving optimal design for scalable parallel implementations. We have briefly reviewed those earlier results and publications which allow us to conclude that we have achieved both goals. However, in this report we have further established that, when used in conjuction with a state-of-the-art parallel I/O system, as can be found on the premier DOE peta-scale platform, the scaling properties of the overall analysis pipeline comprising parallel data access routines degrade rapidly. This finding is problematic and must be addressed if peta-scale data analysis is to be made scalable, or even possible. In order to attempt to address these parallel I/O limitations, we will investigate the use the Adaptable IO System (ADIOS) [LZL+10] to improve I/O performance, while maintaining flexibility for a variety of IO options, such MPI IO, POSIX IO. This system is developed at ORNL and other collaborating institutions, and is being tested extensively on Jaguar-pf. Simulation code being developed on these systems will also use ADIOS to output the data thereby making it easier for other systems, such as ours, to
Limit analysis on FRP-strengthened RC members
Directory of Open Access Journals (Sweden)
D. De Domenico
2014-07-01
Full Text Available Reinforced concrete (RC members strengthened with externally bonded fiber-reinforced-polymer (FRP plates are numerically investigated by a plasticity-based limit analysis approach. The key-concept of the present approach is to adopt proper constitutive models for concrete, steel reinforcement bars (re-bars and FRP strengthening plates according to a multi-yield-criteria formulation. This allows the prediction of concrete crushing, steel bars yielding and FRP rupture that may occur at the ultimate limit state. To simulate such limitstate of the analysed elements, two iterative methods performing linear elastic analyses with adaptive elastic parameters and finite elements (FEs description are employed. The peak loads and collapse mechanisms predicted for FRP-plated RC beams are validated by comparison with the corresponding experimental findings.
Latunde-Dada, Seyi; Bott, Rachel; Hampton, Karl; Leszczyszyn, Oksana Iryna
2015-08-01
Taylor dispersion analysis (TDA) is a fast and simple method for determining hydrodynamic radii. The method is applicable under conditions that allow the solute molecules to diffuse appreciably across the cross section of the flow before its measurement. This mitigates the effects of early stage convection on the dispersion and thus imposes a lower bound on the value of the diffusion coefficient measurable at a given flow speed. In this paper, we use the exact solution to the dispersion problem to analyze solutes outside the limits of TDA. Furthermore, by modeling the early stage convection, we analyze a mixture of two solutes with significantly different sizes that mimics heavily aggregated samples. The results obtained from the fits in both cases were in good agreement to the expected values. This demonstrates the potential of the model to extend dispersion analysis to regimes well outside the TDA limits such as the analysis of large molecules and the use of high flow-rates. PMID:26161948
Reform of Unemployment Compensation in Germany : A Nonparametric Bounds Analysis Using Register Data
Lee, Sokbae; Wilke, Ralf A.
2005-01-01
Economic theory suggests that an extension of the maximum length of entitlement for unemployment benefits increases the duration of unemployment. Empirical results for the reform of the unemployment compensation system in Germany during the 1980s are less clear. The analysis in this paper is motivated by the controversial empirical findings and by recent developments in econometrics for partial identification. We use extensive administrative data with the drawback that registered unemployment...
Stability analysis of chromo-natural inflation and possible evasion of Lyth's bound
Dimastrogiovanni, Emanuela
2013-01-01
We perform the complete stability study of the model of chromo-natural inflation (Adshead and Wyman '12), where, due to its coupling to a SU(2) vector, a pseudo-scalar inflaton chi slowly rolls on a steep potential. As a typical example, one can consider an axion with a sub-Planckian decay constant f. The phenomenology of the model was recently studied (Dimastrogiovanni, Fasiello, and Tolley '12) in the m_g >> H limit, where m_g is the mass of the fluctuations of the vector field, and H the Hubble rate. We show that the inflationary solution is stable for m_g > 2 H, while it otherwise experiences a strong instability due to scalar perturbations in the sub-horizon regime. The tensor perturbations are instead standard, and the vector ones remain perturbatively small. Depending on the parameters, this model can give a gravity wave signal that can be detected in ongoing or forthcoming CMB experiments. This detection can occur even if, during inflation, the inflaton spans an interval of size Delta chi = O (f) whic...
Li, Zhixiong; Yan, Xinping; Wang, Xuping; Peng, Zhongxiao
2016-06-01
In the complex gear transmission systems, in wind turbines a crack is one of the most common failure modes and can be fatal to the wind turbine power systems. A single sensor may suffer with issues relating to its installation position and direction, resulting in the collection of weak dynamic responses of the cracked gear. A multi-channel sensor system is hence applied in the signal acquisition and the blind source separation (BSS) technologies are employed to optimally process the information collected from multiple sensors. However, literature review finds that most of the BSS based fault detectors did not address the dependence/correlation between different moving components in the gear systems; particularly, the popular used independent component analysis (ICA) assumes mutual independence of different vibration sources. The fault detection performance may be significantly influenced by the dependence/correlation between vibration sources. In order to address this issue, this paper presents a new method based on the supervised order tracking bounded component analysis (SOTBCA) for gear crack detection in wind turbines. The bounded component analysis (BCA) is a state of art technology for dependent source separation and is applied limitedly to communication signals. To make it applicable for vibration analysis, in this work, the order tracking has been appropriately incorporated into the BCA framework to eliminate the noise and disturbance signal components. Then an autoregressive (AR) model built with prior knowledge about the crack fault is employed to supervise the reconstruction of the crack vibration source signature. The SOTBCA only outputs one source signal that has the closest distance with the AR model. Owing to the dependence tolerance ability of the BCA framework, interfering vibration sources that are dependent/correlated with the crack vibration source could be recognized by the SOTBCA, and hence, only useful fault information could be preserved in
The nature and limits of interactive communication: A philosophical analysis
Directory of Open Access Journals (Sweden)
Halvor Nordby
2011-04-01
Full Text Available In many modern study programs, teachers and students communicate via internet and other interactive communicative channels. What is the essential nature of this communication? How does interactive communication differ from ordinary face-to-face communication in the most fundamental sense? The article uses conceptual analysis as a philosophical method to explore the intrinsic nature of the concept interactive communication. The aim of this method is to develop a concept definition that matches shared linguistic beliefs about informative examples from internet based communication and information exchange that is central in electronic teaching courses. The article examines several concept definitions and argues in favor of a philosophical information processing analysis of interactive communication. The significance of this analysis has two dimensions. First, it can give teachers and others who are involved in interactive communication a better understanding of the essential differences between interactive and face-toface communication. Second, the analysis can stimulate pedagogical and critical reflection on the nature and limits of internet based communication and electronic teaching tools.
International Nuclear Information System (INIS)
The static method for the evaluation of the limit loads of a perfectly elasto-plastic structure is presented. Using the static theorem of Limit Analysis and the Finite Element Method, a lower bound for the colapso load can be obtained through a linear programming problem. This formulation if then applied to symmetrically loaded shells of revolution and some numerical results of limit loads in nozzles are also presented. (Author)
New results in the limit analysis by secondary modified creep
International Nuclear Information System (INIS)
Two methods for computing upper and lower bounds of colapse loads are proposed by means of generalized creep constitutive relations. The actual material behaviour is rigid-perfectly plastic and the techniques here analized consist in the substitution of this material by a fictitious one which presents steady state creep response. Some analytical examples are also presented. (Author)
Appell, Jürgen; Merentes Díaz, Nelson José
2013-01-01
This monographis a self-contained exposition of the definition and properties of functionsof bounded variation and their various generalizations; the analytical properties of nonlinear composition operators in spaces of such functions; applications to Fourier analysis, nonlinear integral equations, and boundary value problems. The book is written for non-specialists. Every chapter closes with a list of exercises and open problems.
Orso Giacone, G
1982-01-01
It is widely known that atherosclerosis through its complication, i.e. heart and brain infarction, is at the present the main cause of death. The atherosclerotic process has been shown in correlation with hyperlipemia especially as far as the plasma lipoprotein cholesterol level is concerned. A preminent role in removing cholesterol from tissues and arterial walls then in preventing atherosclerosis is played by a specific class of plasma lipoproteins, the high density lipoproteins (HDL). Since the HDL-colesterol level seems to have an inverse correlation with the atherosclerotic disease it is of primary importance to define a reliable and reproducible technique to measure it. One of the aims of this paper was to examine the different methods now available for such a determination. This analysis has underlined the discrepancy among the reference values reported in the literature. However, all the authors agree that only the simultaneous measurement of total and HDL-colesterol levels is of prognostic value. Personal studies are here reported on the relationship between total and HDL-colesterol levels and risk factor of cardiovascular diseases. The two mentioned laboratory analyses have been performed on blood samples from 250 between male and female human subjects of different age. The obtained results show that the highest HDL-colesterol concentrations determined by a lipoprotein precipitation procedure with dextran sulphate, are typical in the first ten years of life both in male and in female, while the lowest levels of plasma HDL-cholesterol have been evintiated during the fifth decade of life, when the total cholesterol and the risk of cardiovascular complications rich the highest values. In a following set of investigations, the already examined blood parameters together with the risk factor values have been examined in two groups of subjects, the first one represented by adult healthy persons the second one by patients of similar age from a cardiovascular
Bhattacherjee, Biplob; Choudhury, Arghya
2015-01-01
In this paper, we search for the regions of the phenomenological minimal supersymmetric standard model (pMSSM) parameter space where one can expect to have moderate Higgs mixing angle ($\\alpha$) with relatively light (up to 600 GeV) additional Higgses after satisfying the current LHC data. We perform a global fit analysis using most updated data (till December 2014) from the LHC and Tevatron experiments. The constraints coming from the precision measurements of the rare b-decays $B_s \\to \\mu^+ \\mu^-$ and $b\\to s \\gamma$ are also considered. We find that low $M_{A}$ $(\\lesssim 350)$ and high $tan\\beta$ $(\\gtrsim 25)$ regions are disfavoured by the combined effect of the global analysis and flavour data. However, regions with Higgs mixing angle $\\alpha \\sim$ 0.1 - 0.8 are still allowed by the current data. We then study the existing direct search bounds on the heavy scalar/pseudoscalar ($\\rm H/A$) and charged Higgs ($\\rm H^\\pm$) masses and branchings at the LHC. It has been found that regions with low to modera...
Directory of Open Access Journals (Sweden)
Ballester Pla, Coralio
2012-03-01
Full Text Available The observation of the actual behavior by economic decision makers in the lab and in the field justifies that bounded rationality has been a generally accepted assumption in many socio-economic models. The goal of this paper is to illustrate the difficulties involved in providing a correct definition of what a rational (or irrational agent is. In this paper we describe two frameworks that employ different approaches for analyzing bounded rationality. The first is a spatial segregation set-up that encompasses two optimization methodologies: backward induction and forward induction. The main result is that, even under the same state of knowledge, rational and non-rational agents may match their actions. The second framework elaborates on the relationship between irrationality and informational restrictions. We use the beauty contest (Nagel, 1995 as a device to explain this relationship.
La observación del comportamiento de los agentes económicos tanto en el laboratorio como en la vida real justifica que la racionalidad acotada sea un supuesto aceptado en numerosos modelos socio-económicos. El objetivo de este artículo es ilustrar las dificultades que conlleva una correcta definición de qué es un agente racional (irracional. En este artículo se describen dos marcos que emplean diferentes metodologías para analizar la racionalidad acotada. El primero es un modelo de segregación espacial donde se contrastan dos metodologías de optimización: inducción hacia atrás y hacia adelante. El resultado principal es que, incluso con el mismo nivel de conocimiento, tanto agentes racionales como irracionales podrían coincidir en sus acciones. El segundo marco trabaja sobre la relación entre irracionalidad y restricción de información. Se utiliza el juego llamado “beauty contest” (Nagel 1995 como mecanismo para explicar dicha relación.
Numerical limit analysis of keyed shear joints in concrete structures
DEFF Research Database (Denmark)
Herfelt, Morten Andersen; Poulsen, Peter Noe; Hoang, Linh Cao;
2016-01-01
This paper concerns the shear capacity of keyed joints, which are transversely reinforced with overlapping U-bar loops. It is known from experimental studies that the discontinuity of the transverse reinforcement affects the capacity as well as the failure mode; however, to the best knowledge of...... the authors, previous theoretical works and present design equations in standards do not account for this important effect. In this paper, a detailed model based on finite element limit analysis is introduced to assess the effect of the discontinuous reinforcement. The model is based on the lower...... experimental results. The results of the model show satisfactory agreement with the experimental observations. The model produces significantly better estimates of the shear capacity than the design equations of Eurocode 2....
Bounding approaches to system identification
Norton, John; Piet-Lahanier, Hélène; Walter, Éric
1996-01-01
In response to the growing interest in bounding error approaches, the editors of this volume offer the first collection of papers to describe advances in techniques and applications of bounding of the parameters, or state variables, of uncertain dynamical systems. Contributors explore the application of the bounding approach as an alternative to the probabilistic analysis of such systems, relating its importance to robust control-system design.
Micrometeoroid and Orbital Debris (MMOD) Shield Ballistic Limit Analysis Program
Ryan, Shannon
2013-01-01
This software implements penetration limit equations for common micrometeoroid and orbital debris (MMOD) shield configurations, windows, and thermal protection systems. Allowable MMOD risk is formulated in terms of the probability of penetration (PNP) of the spacecraft pressure hull. For calculating the risk, spacecraft geometry models, mission profiles, debris environment models, and penetration limit equations for installed shielding configurations are required. Risk assessment software such as NASA's BUMPERII is used to calculate mission PNP; however, they are unsuitable for use in shield design and preliminary analysis studies. The software defines a single equation for the design and performance evaluation of common MMOD shielding configurations, windows, and thermal protection systems, along with a description of their validity range and guidelines for their application. Recommendations are based on preliminary reviews of fundamental assumptions, and accuracy in predicting experimental impact test results. The software is programmed in Visual Basic for Applications for installation as a simple add-in for Microsoft Excel. The user is directed to a graphical user interface (GUI) that requires user inputs and provides solutions directly in Microsoft Excel workbooks.
Lower bound on reliability for Weibull distribution when shape parameter is not estimated accurately
Huang, Zhaofeng; Porter, Albert A.
1990-01-01
The mathematical relationships between the shape parameter Beta and estimates of reliability and a life limit lower bound for the two parameter Weibull distribution are investigated. It is shown that under rather general conditions, both the reliability lower bound and the allowable life limit lower bound (often called a tolerance limit) have unique global minimums over a range of Beta. Hence lower bound solutions can be obtained without assuming or estimating Beta. The existence and uniqueness of these lower bounds are proven. Some real data examples are given to show how these lower bounds can be easily established and to demonstrate their practicality. The method developed here has proven to be extremely useful when using the Weibull distribution in analysis of no-failure or few-failures data. The results are applicable not only in the aerospace industry but anywhere that system reliabilities are high.
The influence of limited kinematic hardening in shakedown analysis
International Nuclear Information System (INIS)
The use of the Design by Analysis concept is a trend in modern pressure vessel and piping calculations. DBA flexibility allow us to deal with unexpected configurations detected at in-service inspections. It is also important, in life extension calculations, when deviations of the original standard hypothesis adopted initially in Design by Formula, can happen. To apply the DBA to structures under variable mechanic and thermal loads, it is necessary that, alternate plasticity and incremental collapse (with instantaneous plastic collapse as a particular case), be precluded. These are two basic failure modes considered by ASME or European Standards in DBA. The shakedown theory is the tool available to achieve this goal. In order to apply it, is necessary only the range of the variable loads and the material properties. Precise, robust and efficient algorithms to solve the very large nonlinear optimization problems generated in numerical applications of the shakedown theory is a recent achievement. Zouain and co-workers developed one of these algorithms for elastic ideally-plastic materials. But, it is necessary to consider more realistic material properties in real practical applications. This paper shows an enhancement of this algorithm to dealing with limited kinematic hardening, a typical property of the usual steels. This is done using internal thermodynamic variables. A discrete algorithm is obtained using a plane stress, mixed finite element, with internal variable. An example, a beam encased in an end, under constant axial force and variable moment is presented to show the importance of considering the limited kinematic hardening in a shakedown analysis. (author)
Special Analysis: Revision of Saltstone Vault 4 Disposal Limits (U)
Energy Technology Data Exchange (ETDEWEB)
Cook, J
2005-05-26
New disposal limits have been computed for Vault 4 of the Saltstone Disposal Facility based on several revisions to the models in the existing Performance Assessment and the Special Analysis issued in 2002. The most important changes are the use of a more rigorous groundwater flow and transport model, and consideration of radon emanation. Other revisions include refinement of the aquifer mesh to more accurately model the footprint of the vault, a new plutonium chemistry model accounting for the different transport properties of oxidation states III/IV and V/VI, use of variable infiltration rates to simulate degradation of the closure system, explicit calculation of gaseous releases and consideration of the effects of settlement and seismic activity on the vault structure. The disposal limits have been compared with the projected total inventory expected to be disposed in Vault 4. The resulting sum-of-fractions of the 1000-year disposal limits is 0.2, which indicates that the performance objectives and requirements of DOE 435.1 will not be exceeded. This SA has not altered the conceptual model (i.e., migration of radionuclides from the Saltstone waste form and Vault 4 to the environment via the processes of diffusion and advection) of the Saltstone PA (MMES 1992) nor has it altered the conclusions of the PA (i.e., disposal of the proposed waste in the SDF will meet DOE performance measures). Thus a PA revision is not required and this SA serves to update the disposal limits for Vault 4. In addition, projected doses have been calculated for comparison with the performance objectives laid out in 10 CFR 61. These doses are 0.05 mrem/year to a member of the public and 21.5 mrem/year to an inadvertent intruder in the resident scenario over a 10,000-year time-frame, which demonstrates that the 10 CFR 61 performance objectives will not be exceeded. This SA supplements the Saltstone PA and supersedes the two previous SAs (Cook et al. 2002; Cook and Kaplan 2003).
Special Analysis: Revision of Saltstone Vault 4 Disposal Limits (U)
International Nuclear Information System (INIS)
New disposal limits have been computed for Vault 4 of the Saltstone Disposal Facility based on several revisions to the models in the existing Performance Assessment and the Special Analysis issued in 2002. The most important changes are the use of a more rigorous groundwater flow and transport model, and consideration of radon emanation. Other revisions include refinement of the aquifer mesh to more accurately model the footprint of the vault, a new plutonium chemistry model accounting for the different transport properties of oxidation states III/IV and V/VI, use of variable infiltration rates to simulate degradation of the closure system, explicit calculation of gaseous releases and consideration of the effects of settlement and seismic activity on the vault structure. The disposal limits have been compared with the projected total inventory expected to be disposed in Vault 4. The resulting sum-of-fractions of the 1000-year disposal limits is 0.2, which indicates that the performance objectives and requirements of DOE 435.1 will not be exceeded. This SA has not altered the conceptual model (i.e., migration of radionuclides from the Saltstone waste form and Vault 4 to the environment via the processes of diffusion and advection) of the Saltstone PA (MMES 1992) nor has it altered the conclusions of the PA (i.e., disposal of the proposed waste in the SDF will meet DOE performance measures). Thus a PA revision is not required and this SA serves to update the disposal limits for Vault 4. In addition, projected doses have been calculated for comparison with the performance objectives laid out in 10 CFR 61. These doses are 0.05 mrem/year to a member of the public and 21.5 mrem/year to an inadvertent intruder in the resident scenario over a 10,000-year time-frame, which demonstrates that the 10 CFR 61 performance objectives will not be exceeded. This SA supplements the Saltstone PA and supersedes the two previous SAs (Cook et al. 2002; Cook and Kaplan 2003)
Novel method for error limit determination in x-ray reflectivity analysis
International Nuclear Information System (INIS)
A novel error limit determination method for x-ray reflectivity (XRR) analysis is developed and applied to data measured from atomic-layer-deposited aluminium oxide on silicon. The analysis here is based on Parratt's formalism and on a fitness defined as a mean-squared error between a measurement and a fit in logarithmic scales. The mathematically derived upper bound for an error uses a trick which divides the fitness into two parts. The divided original fitness equals the fitness between a measurement and a numerically optimal but unknown fit (the first part) plus the fitness between the unknown optimal fit and the known original fit (the second part). In practical error determination, the fitness in the first part is the fitness of noise and it is approximated using a separate simulation and in the second part, the unknown optimal fit is considered as a variable to be optimized. An efficient implementation is presented for the error determination and the determined parameters were 42.4 ± 0.12 nm (0.3%), 3.15 ± 0.11 g cm-3 (3.5%) and 0.80 ± 0.06 nm (7.5%) for the thickness, the mass density and the surface roughness, respectively. Although the formalized error may need some fine tuning as future work since it gives an asymptotic estimate, it still gave reasonable results in the case of systematic error caused by nonideal fit
Novel method for error limit determination in x-ray reflectivity analysis
Energy Technology Data Exchange (ETDEWEB)
Tiilikainen, J; Mattila, M; Hakkarainen, T; Lipsanen, H [Department of Micro and Nanosciences, Helsinki University of Technology, Micronova, PO BOX 3500, FI-02015 TKK (Finland)], E-mail: jouni.tiilikainen@tkk.fi
2008-06-07
A novel error limit determination method for x-ray reflectivity (XRR) analysis is developed and applied to data measured from atomic-layer-deposited aluminium oxide on silicon. The analysis here is based on Parratt's formalism and on a fitness defined as a mean-squared error between a measurement and a fit in logarithmic scales. The mathematically derived upper bound for an error uses a trick which divides the fitness into two parts. The divided original fitness equals the fitness between a measurement and a numerically optimal but unknown fit (the first part) plus the fitness between the unknown optimal fit and the known original fit (the second part). In practical error determination, the fitness in the first part is the fitness of noise and it is approximated using a separate simulation and in the second part, the unknown optimal fit is considered as a variable to be optimized. An efficient implementation is presented for the error determination and the determined parameters were 42.4 {+-} 0.12 nm (0.3%), 3.15 {+-} 0.11 g cm{sup -3} (3.5%) and 0.80 {+-} 0.06 nm (7.5%) for the thickness, the mass density and the surface roughness, respectively. Although the formalized error may need some fine tuning as future work since it gives an asymptotic estimate, it still gave reasonable results in the case of systematic error caused by nonideal fit.
Directory of Open Access Journals (Sweden)
Ephraim S. Gower
2014-12-01
Full Text Available In this study, a generic analysis of sensor impulse response effects on linearly filtered channel noise is presented to illustrate the resulting variations to the Cramèr–Rao lower bounds (CRLBs of signal parameter estimators in signal processing and communication applications. The authors start by deriving the density function of a filtered signal, which is shown to be a mixture density, and hence the exact expressions for the mean and variance. Simulation results are used to confirm the derivations, which are then used to investigate the effects of impulse response length and variance, as well as channel noise length and variance effects on the resulting CRLBs. Results indicate that for non-zero-mean channel noise and impulse responses, the resulting mean of filtered noise can be relatively large causing adverse deviations to parameter estimations. The filtered noise variance is shown to be proportional to the impulse response energy, where for long duration of signal capture the CRLB is significantly increased.
Fire risk analysis: a discussion on uncertainties and limitations
International Nuclear Information System (INIS)
A fire risk analysis, using probabilistic methods, attempts to model fire scenarios that can be described in terms of the following elements: ignition of fire, growth of the fire, detection and suppression processes, impact on cables and other equipment, and response of the automatic safety and control systems and plant operators. The level of uncertainties and limitations of the analysis varies among these elements. Although the potential failure modes of cables and electrical circuits have been debated for a long time, there are some uncertainties in our understanding of the failure modes of equipment under fire conditions. Smoke propagation and smoke damage have generally been omitted from fire risk studies. Shorts within electronic circuit boards caused by soot deposits are not modeled, such failures can have an impact on the information provided to the control room operator. The operators' response to the changes on the control board is certainly a complex issue. The behavior of control room operators when there is a fire in the control room is also the subject of much debate. Of specific concern is the proper transfer of the controls to the remote shutdown panel. Another area of much debate centers around the control of combustibles. Several studies have taken credit for the house-keeping procedures to screen potential fire scenarios in areas of a plant that contain a large collection of cables (e.g., a cable tunnel or cable shaft). In such cases, clearly the debate is over the likelihood of a fire that can cause damage. None of the fire risk analyses familiar to the authors have properly modeled the simultaneous effect of a fire on multi-units. (author)
Limitations in simulator time-based human reliability analysis methods
International Nuclear Information System (INIS)
Developments in human reliability analysis (HRA) methods have evolved slowly. Current methods are little changed from those of almost a decade ago, particularly in the use of time-reliability relationships. While these methods were suitable as an interim step, the time (and the need) has come to specify the next evolution of HRA methods. As with any performance-oriented data source, power plant simulator data have no direct connection to HRA models. Errors reported in data are normal deficiencies observed in human performance; failures are events modeled in probabilistic risk assessments (PRAs). Not all errors cause failures; not all failures are caused by errors. Second, the times at which actions are taken provide no measure of the likelihood of failures to act correctly within an accident scenario. Inferences can be made about human reliability, but they must be made with great care. Specific limitations are discussed. Simulator performance data are useful in providing qualitative evidence of the variety of error types and their potential influences on operating systems. More work is required to combine recent developments in the psychology of error with the qualitative data collected at stimulators. Until data become openly available, however, such an advance will not be practical
Reflecting Magnon Bound States
Ahn, C; Rey, S J
2008-01-01
In N=4 super Yang-Mills spin chain, we compute reflection amplitudes of magnon bound-state off giant graviton. We first compute the reflection amplitude off Y=0 brane boundary and compare it with the scattering amplitude between two magnon bound-states in the bulk. We find that analytic structure of the two amplitudes are intimately related each other: the boundary reflection amplitude is a square-root of the bulk scattering amplitude. Using such relation as a guide and taking known results at weak and strong coupling limits as inputs, we find the reflection amplitude of an elementary magnon off Z=0 giant graviton boundary. The reflection phase factor is shown to solve crossing and unitarity relations. We then compute the reflection amplitude of magnon bound-state off the Z=0 brane boundary and observe that its analytic structures are again intimately related to the bulk scattering and the Y=0 boundary reflection amplitudes. We also take dyonic giant magnon limit of these reflection amplitudes and confirm tha...
Causal Entropy Bound for a Spacelike Region
Brustein, R.; Veneziano, G.
2000-06-01
The identification of a causal-connection scale motivates us to propose a new covariant bound on entropy within a generic spacelike region. This ``causal entropy bound,'' scaling as EV, and thus lying around the geometric mean of Bekenstein's S/ER and holographic S/A bounds, is checked in various ``critical'' situations. In the case of limited gravity, Bekenstein's bound is the strongest while naive holography is the weakest. In the case of strong gravity, our bound and Bousso's holographic bound are stronger than Bekenstein's, while naive holography is too tight, and hence typically wrong.
Comparisons of Limit Analysis Solutions and Random Search Solutions on Slope Critical Slip SUrface
Institute of Scientific and Technical Information of China (English)
JianfengWANG
1998-01-01
The object of this paper is twofold:to present a kinematics limit analysis for assessing the safety of slope or its critical slip surface,and to compare the searched slip surface with that by limit analysis.
International Nuclear Information System (INIS)
Tritium in the UK environment causes low radiation doses to the public, but uncertainty exists in the dose coefficient for the organically-bound component of tritium (OBT). This can affect the assessment of effective doses to representative persons. Contributing to that uncertainty is poor knowledge of the body retention time of OBT and how this varies for different OBT compounds in food. This study was undertaken to measure the retention time of tritium by volunteers after eating sole from Cardiff Bay, which may contain OBT from discharges from the GE Healthcare Ltd. plant. Five volunteers provided samples of excreta over periods up to 150 days after intake. Preliminary analysis of the results suggests retention of total tritium with body half-times ranging from 4 to 11 days, with no evidence of a significant contribution due to retention with a longer half-time. This range covers the half-time of 10 days used by the ICRP for tritiated water. The short timescale could be due to rapid hydrolysis in body tissues of the particular form of OBT used in this study. Implications for the dose coefficient for OBT are that the use of the ICRP value of 4.2 10-11 Sv Bq-1 may be cautious in this specific situation, and the value of 1.6 10-11 Sv Bq-1 used by the ICRP for tritiated water might even be more appropriate. These observations on dose coefficients are separate from any implications of recent discussion on whether the tritium radiation weighting factor should be increased from 1 to 2. (author)
Schulz, M D; Vidal, J
2016-01-01
We discuss the emergence of bound states in the low-energy spectrum of the string-net Hamiltonian in the presence of a string tension. In the ladder geometry, we show that a single bound state arises either for a finite tension or in the zero-tension limit depending on the theory considered. In the latter case, we perturbatively compute the binding energy as a function of the total quantum dimension. We also address this issue in the honeycomb lattice where the number of bound states in the topological phase depends on the total quantum dimension. Finally, the internal structure of these bound states is analyzed in the zero-tension limit.
Complex bounds for multimodal maps: bounded combinatorics
Smania, Daniel
2000-01-01
We proved the so called complex bounds for multimodal, infinitely renormalizable analytic maps with bounded combinatorics: deep renormalizations have polynomial-like extensions with definite modulus. The complex bounds is the first step to extend the renormalization theory of unimodal maps to multimodal maps.
Upper-bound solutions to flow through conical converging dies
International Nuclear Information System (INIS)
Limit analysis is a very versatile modeling technique that can be used to study metal-forming processes. The upper-bound analysis can be used to predict an upper limit on the power requirements. This work reviews some upper-bound solutions that describe flow through conical converging dies. The concept of a trapezoidal field is introduced and dealt with in great detail, and the power requirements based on the trapezoidal field are calculated. Results are compared with those obtained using spherical and triangular fields. The relative stress expression has been developed analytically and the final optimization with respect to the pseudoindependent parameter is done numerically. The trapezoidal field predicts a lower upper-bound solution for small semicone angles. The range over which the trapezoidal field solution becomes dominant increases with increasing friction factor
Bounding probabilistic safety assessment probabilities by reality
International Nuclear Information System (INIS)
The investigation of the failure in systems where failure is a rare event makes the continual comparisons between the developed probabilities and empirical evidence difficult. The comparison of the predictions of rare event risk assessments with historical reality is essential to prevent probabilistic safety assessment (PSA) predictions from drifting into fantasy. One approach to performing such comparisons is to search out and assign probabilities to natural events which, while extremely rare, have a basis in the history of natural phenomena or human activities. For example the Segovian aqueduct and some of the Roman fortresses in Spain have existed for several millennia and in many cases show no physical signs of earthquake damage. This evidence could be used to bound the probability of earthquakes above a certain magnitude to less than 10-3 per year. On the other hand, there is evidence that some repetitive actions can be performed with extremely low historical probabilities when operators are properly trained and motivated, and sufficient warning indicators are provided. The point is not that low probability estimates are impossible, but continual reassessment of the analysis assumptions, and a bounding of the analysis predictions by historical reality. This paper reviews the probabilistic predictions of PSA in this light, attempts to develop, in a general way, the limits which can be historically established and the consequent bounds that these limits place upon the predictions, and illustrates the methodology used in computing such limits. Further, the paper discusses the use of empirical evidence and the requirement for disciplined systematic approaches within the bounds of reality and the associated impact on PSA probabilistic estimates
L-Area Cavitation Tests Final Analysis - Limits Application
International Nuclear Information System (INIS)
The L-Area cavitation test was designed to better define the onset of cavitation in the reactor system. The onset of gas evolution in the effluent piping and pump cavitation was measured using state-of-the-art equipment to provide data with a high confidence and low uncertainty level. The limits calculated from the new data will allow an approximate two percent increase in reactor power if the reactor is effluent temperature-limited with no compromise in reactor safety
Petawatt laser absorption bounded
Levy, Matthew C; Tabak, Max; Libby, Stephen B; Baring, Matthew G
2014-01-01
The interaction of petawatt ($10^{15}\\ \\mathrm{W}$) lasers with solid matter forms the basis for advanced scientific applications such as table-top particle accelerators, ultrafast imaging systems and laser fusion. Key metrics for these applications relate to absorption, yet conditions in this regime are so nonlinear that it is often impossible to know the fraction of absorbed light $f$, and even the range of $f$ is unknown. Here using a relativistic Rankine-Hugoniot-like analysis, we show for the first time that $f$ exhibits a theoretical maximum and minimum. These bounds constrain nonlinear absorption mechanisms across the petawatt regime, forbidding high absorption values at low laser power and low absorption values at high laser power. For applications needing to circumvent the absorption bounds, these results will accelerate a shift from solid targets, towards structured and multilayer targets, and lead the development of new materials.
Alternation-Trading Proofs, Linear Programming, and Lower Bounds
Williams, Ryan
2010-01-01
A fertile area of recent research has demonstrated concrete polynomial time lower bounds for solving natural hard problems on restricted computational models. Among these problems are Satisfiability, Vertex Cover, Hamilton Path, Mod6-SAT, Majority-of-Majority-SAT, and Tautologies, to name a few. The proofs of these lower bounds follow a certain proof-by-contradiction strategy that we call alternation-trading. An important open problem is to determine how powerful such proofs can possibly be. We propose a methodology for studying these proofs that makes them amenable to both formal analysis and automated theorem proving. We prove that the search for better lower bounds can often be turned into a problem of solving a large series of linear programming instances. Implementing a small-scale theorem prover based on this result, we extract new human-readable time lower bounds for several problems. This framework can also be used to prove concrete limitations on the current techniques.
LASER MICROPROBE MASS ANALYSIS DETECTION LIMITS AND LATERAL RESOLUTION
Wieser, P.; Wurster, R.; Seiler, H.
1984-01-01
Detection limits of the elements Li, Na, Fe, Ni, Zn, Cd, Hg and Pb obtained by lasermicroprobe massanalysis (LAMMAR 500, Leybold-Heraeus) of organic particulate matter doped with salts are given. The difference between optical and analytical spatial resolution of the lasermicroprobe is discussed. Hints are given that lateral effects may influence the microanalytical results.
International Nuclear Information System (INIS)
Many structural components, such as rolled sheets, directionally solidified superalloys and composites are made of anisotropic materials. The knowledge of limit load is useful in the design and the sizing of these components and structures. This paper presents the extension of the modified mα - method to anisotropic materials. Mura's variational principle is employed in conjunction with repeated elastic finite element analyses (FEA). The secant modulus of the discretized finite elements in the reference direction components. The modified initial elastic properties are adopted to ensure the 'elastic' stress fields satisfy the anisotropic yield surface. Using the notion of 'leap-frogging to limit state,' improved lower-bound limit loads can be obtained. The formulation is applied to two anisotropic components, and the limit load estimates are compared with those using elastic compensation method and inelastic FEA. (author)
PLASTIC LIMIT ANALYSIS OF DUCTILE COMPOSITE STRUCTURES FROM MICRO-TO MACRO-MECHANICAL ANALYSIS
Institute of Scientific and Technical Information of China (English)
Hongtao Zhang; Yinghua Liu; Bingye Xu
2009-01-01
The load-bearing capacity of ductile composite structures comprised of periodic composites is studied by a combined micro/macromechanical approach. Firstly, on the microscopic level, a representative volume element (RVE) is selected to reflect the microstructures of the composite materials and the constituents are assumed to be elastic perfectly-plastic. Based on the homogenization theory and the static limit theorem, an optimization formulation to directly calculate the macroscopic strength domain of the RVE is obtained. The finite element modeling of the static limit analysis is formulated as a nonlinear mathematical programming and solved by the sequential quadratic programming method, where the temperature parameter method is used to construct the self-stress field. Secondly, Hill's yield criterion is adopted to connect the micromechanical and macromechanical analyses. And the limit loads of composite structures are worked out on the macroscopic scale. Finally, some examples and comparisons are shown.
DEFF Research Database (Denmark)
Milana, Marcella
studies often drawn on literature on globalization, governance and education emphasizing Europeanization (Nóvoa and Lawn 2002, Lawn and Grek 2012), and ‘governance by numbers’ (Martens and Niemann 2010, Grek 2009). In these accounts, territorially-bound polity as (also) an influential political setting...... specific interests, and shaping international agendas for AE (Milana and Holford 2014, Panitsidou 2013, forthcoming; Rubenson 2006, 2009, forthcoming), through the adoption of new governance mechanisms (Jacobi 2009, Ioannidou 2007), and the promotion of a monitoring culture (Hamilton 2014, Tett 2014). Such...... for public policy is often out of sight or invisible. This contribution questions whether territorially-bound polity might still be of relevance to consider when comprehending concrete decisions on (and justifications for) the share of national budgets that goes in support of education within...
Arntz, Melanie; Simon M.S. Lo; Wilke, Ralf A.
2007-01-01
"In this paper we derive nonparametric bounds for the cumulative incidence curve within a competing risks model with partly identified interval data. As an advantage over earlier attempts our approach also gives valid results in case of dependent competing risks. We apply our framework to empirically evaluate the effect of unemployment benefits on observed migration of unemployed workers in Germany. Our findings weakly indicate that reducing the entitlement length for unemployment benefits in...
Anonymity in a Limit-Order Market: An Experimental Analysis
Majois, Christophe
2008-01-01
In this paper, we adopt an experimental approach to evaluate the impact of pre-trade anonymity in order-driven markets. More specifically, we build an experimental design of an electronic limit-order market, and compare two settings: one in which traders observe the identities of agents placing orders in the order book, and the other one where this information is not available on market screens. We find that ID code disclosure does not alter liquidity, efficiency or traders’ pr...
Framing Financial Responsibility : An analysis of the limitations of accounting
Bay, Charlotta
2011-01-01
In organisations, accounting—understood broadly as calculative practices—is claimed to serve as a critical vehicle when introducing forms of individual financial responsibility. Whereas most prior accounting research has been preoccupied with asserting this claim, this paper opens an opportunity to examine the limitations of accounting as a technology of responsibilisation. It does so by moving the empirical focus beyond the borders of people’s work settings and into the private sphere of eve...
Analysis of management of the dance internship Dance Without Limits
Hejnová, Klára
2014-01-01
This thesis focuses on issues related to the organization of cultural projects. The first part is devoted to definitions of project and internship and the specifics of cultural project. The following theoretical point describes the project staffing, strategic planning, marketing, financing and important phases of projects. The management of internship Dance without limits is analyzed in detail in practical part, which is completed with practical knowledge of the organization of this event. Th...
Analysis of TdeV guard limiters by surface spectroscopies
International Nuclear Information System (INIS)
In this study we have analysed coupons cut from one of the internal components of the TdeV tokamak, the stainless-steel side sheeting of a guard limiter, which was removed when the tokamak was modified at the end of 1988. Depth profiles of the accumulated layer of contaminants have been compiled by a variety of surface analytical techniques, including Auger electron spectroscopy, elastic recoil detection and scanning electron microscopy. Melting, arcing, bubbles and large exfoliated layers of coating are observed on the surface of the guard limiter. The damage becomes less severe with increasing distance from the plasma and disappears near the wall. The deposits consist of a mixture of carbon, oxygen, stainless steel and Inconel. Most of the deposited impurity is carbon. Of the deposited metal mixture, only about 6% is Inconel, implying that metal impurities originated mainly from the stainless-steel foils that form a frame around the guard limiter, whereas the Inconel bars were relatively untouched. The metal concentration is a maximum at the surface, coinciding with the maximum concentration of oxygen. Metal carbide appears to be formed with the metal deposits near the surface and at the interface with the substrate, whereas the middle layer consists mainly of ''amorphous'' carbon. (Author)
International Nuclear Information System (INIS)
The molecular chaperone-like reactivating factor for adenosylcobalamin (coenzyme B12) dependent diol dehydratase was crystallized in ADP-bound and nucleotide-free forms. Preliminary X-ray analysis indicated that crystals are orthorhombic and diffract to 2.0 Å. Adenosylcobalamin (coenzyme B12) dependent diol dehydratase (EC 4.2.1.28) catalyzes the conversion of 1,2-diols and glycerol to the corresponding aldehydes. It undergoes mechanism-based inactivation by glycerol. The diol dehydratase-reactivating factor (DDR) reactivates the inactivated holoenzymes in the presence of adenosylcobalamin, ATP and Mg2+ by mediating the release of a damaged cofactor. This molecular chaperone-like factor was overexpressed in Escherichia coli, purified and crystallized in the ADP-bound and nucleotide-free forms by the sandwich-drop vapour-diffusion method. The crystals of the ADP-bound form belong to the orthorhombic system, with space group P212121 and unit-cell parameters a = 83.26, b = 84.60, c = 280.09 Å, and diffract to 2.0 Å. In the absence of nucleotide, DDR crystals were orthorhombic, with space group P212121 and unit-cell parameters a = 81.92, b = 85.37, c = 296.99 Å and diffract to 3.0 Å. Crystals of both forms were suitable for structural analysis
Vichansavakul, Kittaya
Breast cancer is the second leading cause of death among women in the US. Although early detection and treatment help to increase survival rates, some unfortunate patients develop metastatic breast cancer that has no cure. Palliative treatment is the main objective in this group of patients in order to prolong life and reduce toxicities from interventions. In the advancement of treatment for metastatic breast cancer, solvent-based paclitaxel has been widely used. However, solvent-based paclitaxel often causes adverse reactions. Therefore, researchers have developed a new chemotherapy based on nanotechnology. One of these drugs is the Nanoparticle albumin-bound Paclitaxel. This nanodrug aims to increase therapeutic index by reducing adverse reactions from solvents and to improve efficacy of conventional cytotoxic chemotherapy. Breast cancer is a disease with high epidemiological and economic burden. The treatment of metastatic breast cancer has not only high direct costs but also high indirect costs. Breast cancer affects mass populations, especially women younger than 50 years of age. It relates to high indirect costs due to lost productivity and premature death because the majority of these patients are in the workforce. Because of the high cost of breast cancer therapies and short survival rates, the question is raised whether the costs and benefits are worth paying or not. Due to the rising costs in healthcare and new financing policies that have been developed to address this issue, economic evaluation is an important aspect of the development and use of any new interventions. To guide policy makers on how to allocate limited healthcare resources in the most efficient and effective manner, many economic evaluation methods can be used to measure the costs, benefits, and impacts of healthcare innovations. Currently, economic evaluation and health outcomes studies have focused greatly on cost-effectiveness and cost-utility analysis. However, the previous studies
Limit of detection values in data analysis: do they matter?
Wood, M.D.; Beresford, N. A.; Copplestone, D
2011-01-01
Data sets containing values below the limit of detection (LOD) are known as ‘censored data sets’. Such data sets are encountered regularly in most fields of environmental contaminant research. When analysing these data, it is necessary to decide how values below the LOD should be treated. A range of approaches have been proposed, and adopted to varying degrees, within the peer-reviewed literature. These include: (i) treating the LOD value as the absolute value (i.e. if the LOD value is
Exploring the limits of safety analysis in complex technological systems
Sornette, D; Kroeger, W
2012-01-01
From biotechnology to cyber-risks, most extreme technological risks cannot be reliably estimated from historical statistics. Engineers resort to probability safety analysis (PSA), which consists in developing models to simulate accidents, potential scenarios, their severity and frequency. However, even the best safety analysis struggles to account for evolving risks resulting from inter-connected networks and cascade effects. Taking nuclear risks as an example, the predicted plant-specific distribution of losses is found to be significantly underestimated when compared with available empirical records. A simple cascade model suggests that the classification of the different possible safety regimes is intrinsically unstable in the presence of cascades. Even the best probabilistic safety analysis requires additional continuous validation, making the best use of the experienced realized incidents, near misses and accidents.
Analysis of potential evapotranspiration using limited weather data
Valipour, Mohammad
2014-09-01
The most important weather variations are temperature (T), relative humidity (RH), and wind speed (u) for evapotranspiration models in limited data conditions. This study aims to compare three T-based formula, T/RH-based formula, and T/RH/u-based formula to detect the performance of them under limited data and different weather conditions. For this purpose, weather data were gathered from 181 synoptic stations in 31 provinces of Iran. The potential evapotranspiration was compared with the FAO Penman-Monteith method. The results showed that T-based formula, T/RH-based formula, and T/RH/u-based formula estimated potential evapotranspiration with R 2 >0.93 for 6, 12, and 30 provinces of Iran, respectively. They are more suitable for southeast of Iran (YA, KE, SB, and SK). The best precise method was the T/RH/u-based formula for SK and GO. Finally, a list of the best performance of each method has been presented to use other regions and next researches according to values of temperature, relative humidity, and wind speed. The best weather conditions to use the formulas are 14-26 °C and 2.50-3.50 m/s for temperature and wind speed, respectively.
Limit load analysis of thick-walled concrete structures
International Nuclear Information System (INIS)
The paper illustrates the interaction of constitutive modeling and finite element solution techniques for limit load prediction of concrete structures. On the constitutive side, an engineering model of concrete fracture is developed in which the Mohr-Coulomb criterion is augmented by tension cut-off to describe incipient failure. Upon intersection with the stress path the failure surface collapses for brittle behaviour according to one of three softening rules, no-tension, no-cohesion, and no-friction. The stress transfer accompanying the energy dissipation during local failure is modelled by several fracture rules which are examined with regard to ultimate load prediction. On the numerical side the effect of finite element idealization is studied first as far as ultimate load convergence is concerned. Subsequently, incremental tangential and initial load techniques are compared together with the effect of step size. Limit load analyses of a thick-walled concrete ring and a lined concrete reactor closure conclude the paper with examples from practical engineering. (orig.)
Circuit lower bounds in bounded arithmetics
Czech Academy of Sciences Publication Activity Database
Pich, Ján
2015-01-01
Roč. 166, č. 1 (2015), s. 29-45. ISSN 0168-0072 R&D Projects: GA AV ČR IAA100190902 Keywords : bounded arithmetic * circuit lower bounds Subject RIV: BA - General Mathematics Impact factor: 0.548, year: 2014 http://www.sciencedirect.com/science/article/pii/S0168007214000888
Faassen, Elisabeth J; Antoniou, Maria G; Beekman-Lukassen, Wendy; Blahova, Lucie; Chernova, Ekaterina; Christophoridis, Christophoros; Combes, Audrey; Edwards, Christine; Fastner, Jutta; Harmsen, Joop; Hiskia, Anastasia; Ilag, Leopold L; Kaloudis, Triantafyllos; Lopicic, Srdjan; Lürling, Miquel; Mazur-Marzec, Hanna; Meriluoto, Jussi; Porojan, Cristina; Viner-Mozzini, Yehudit; Zguna, Nadezda
2016-03-01
Exposure to β-N-methylamino-l-alanine (BMAA) might be linked to the incidence of amyotrophic lateral sclerosis, Alzheimer's disease and Parkinson's disease. Analytical chemistry plays a crucial role in determining human BMAA exposure and the associated health risk, but the performance of various analytical methods currently employed is rarely compared. A CYANOCOST initiated workshop was organized aimed at training scientists in BMAA analysis, creating mutual understanding and paving the way towards interlaboratory comparison exercises. During this workshop, we tested different methods (extraction followed by derivatization and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis, or directly followed by LC-MS/MS analysis) for trueness and intermediate precision. We adapted three workup methods for the underivatized analysis of animal, brain and cyanobacterial samples. Based on recovery of the internal standard D₃BMAA, the underivatized methods were accurate (mean recovery 80%) and precise (mean relative standard deviation 10%), except for the cyanobacterium Leptolyngbya. However, total BMAA concentrations in the positive controls (cycad seeds) showed higher variation (relative standard deviation 21%-32%), implying that D₃BMAA was not a good indicator for the release of BMAA from bound forms. Significant losses occurred during workup for the derivatized method, resulting in low recovery (BMAA was found in a trichloroacetic acid soluble, bound form and we recommend including this fraction during analysis. PMID:26938542
Directory of Open Access Journals (Sweden)
Elisabeth J. Faassen
2016-02-01
Full Text Available Exposure to β-N-methylamino-l-alanine (BMAA might be linked to the incidence of amyotrophic lateral sclerosis, Alzheimer’s disease and Parkinson’s disease. Analytical chemistry plays a crucial role in determining human BMAA exposure and the associated health risk, but the performance of various analytical methods currently employed is rarely compared. A CYANOCOST initiated workshop was organized aimed at training scientists in BMAA analysis, creating mutual understanding and paving the way towards interlaboratory comparison exercises. During this workshop, we tested different methods (extraction followed by derivatization and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS analysis, or directly followed by LC-MS/MS analysis for trueness and intermediate precision. We adapted three workup methods for the underivatized analysis of animal, brain and cyanobacterial samples. Based on recovery of the internal standard D3BMAA, the underivatized methods were accurate (mean recovery 80% and precise (mean relative standard deviation 10%, except for the cyanobacterium Leptolyngbya. However, total BMAA concentrations in the positive controls (cycad seeds showed higher variation (relative standard deviation 21%–32%, implying that D3BMAA was not a good indicator for the release of BMAA from bound forms. Significant losses occurred during workup for the derivatized method, resulting in low recovery (<10%. Most BMAA was found in a trichloroacetic acid soluble, bound form and we recommend including this fraction during analysis.
International Nuclear Information System (INIS)
Under field conditions in soil the transformation of TNT with Stropharia rugosoannulata leads to the fixation of TNT metabolites within the organic soil matrix and causes a significant detoxification and decrease of bioavailability. To obtain high amounts of non-extractable compounds for investigation of the binding type (15N-NMR-spectroscopy) and the stability of the formed bound residues, the remediation was carried out with extremely high concentrations of added 14C-TNT or 15N-TNT (8.9 g/kg soil dry weight). After 176 days of incubation 2.1 g TNT/kg soil were fixed as bound residues. For control, a second reactor with contaminated soil was incubated without the fungus. Only 0.9 g TNT/kg soil dry weight were transformed and fixed by the autochthonous microflora of the soil and nearly all of the extractable radioactivity was represented by the parent TNT in the control. The immobilized residues were extensively examined by stressing the soil with different physico-chemical and microbial treatments in order to asses the maximum remobilization potential under environmental worst-case conditions. The stability of the residues produced by the fungal process was compared within the joint research groups to those residues originated from two different anaerob/aerob remediation techniques of collaborating groups from Marburg and Stuttgart. All biological treatments were effective and the 'bound residues' were resistant to environmental stress to a large extent. Highly stable amide bonds of the labelled nitrogen are the resulting bonds to organic soil matrix, which take part in the process of humification. (orig.)
Takahashi, Takéo
2003-01-01
In this paper, we study a fluid--rigid-body interaction problem. The motion of the fluid is modeled by the Navier-Stokes equations, written in an unknown bounded domain depending on the displacement of the rigid body. Our main result yields existence and uniqueness of strong solutions. In the two-dimensional case, the solutions are global provided that the rigid body does not touch the boundary. In the three-dimensional case, we obtain local-in-time existence and global existen...
Limits, choices, expectation: methodological horizons to history textbooks analysis
Directory of Open Access Journals (Sweden)
Jean Carlos Moreno
2012-03-01
Full Text Available This article presents some possibilities related to History textbooks analysis, in a direction of a construction of a methodology outline that addresses together at the same time different sides of the History Education Disciplinary Code and its application and the production situation of these cultural objects. In this way, in one hand, the purpose is to know how the textbooks are in the schooling and the printed culture, both that are modernity projects, sharing the book history trajectory, without forget the force field that gives to it sustentation in each context. Concomitantly the content analysis needs to pay attention to the specific aspects of History school teaching, these aspects that show the identity, language, affection, moral development, cognition and expectation horizons.
Exploring the limits of safety analysis in complex technological systems
Sornette, D.; Maillart, T.; Kroeger, W.
2012-01-01
From biotechnology to cyber-risks, most extreme technological risks cannot be reliably estimated from historical statistics. Therefore, engineers resort to predictive methods, such as fault/event trees in the framework of probabilistic safety assessment (PSA), which consists in developing models to identify triggering events, potential accident scenarios, and estimate their severity and frequency. However, even the best safety analysis struggles to account for evolving risks resulting from in...
Structural Power: The limits of neorealist power analysis
GUZZINI, Stefano
1993-01-01
(The article is an earlier version of Chapters 5 and 6 of the author's EUI PhD Thesis, 1994.) http://hdl.handle.net/1814/5139 Realism explains the ruling of the international system through the underlying distribution of power among states. Increasingly, analysts have found this power analysis inadequate, and they have developed new concepts, most prominently structural power. The usage of structural power actually entails three different meanings, namely indirect institutional power, ...
The nature and limits of interactive communication: A philosophical analysis
Halvor Nordby
2011-01-01
In many modern study programs, teachers and students communicate via internet and other interactive communicative channels. What is the essential nature of this communication? How does interactive communication differ from ordinary face-to-face communication in the most fundamental sense? The article uses conceptual analysis as a philosophical method to explore the intrinsic nature of the concept interactive communication. The aim of this method is to develop a concept definition that matches...
Bounded Densities and Their Derivatives
DEFF Research Database (Denmark)
Kozine, Igor; Krymsky, V.
2009-01-01
This paper describes how one can compute interval-valued statistical measures given limited information about the underlying distribution. The particular focus is on a bounded derivative of a probability density function and its combination with other available statistical evidence for computing...
Analysis of Advanced Thermoelectric Materials and Their Functional Limits
Kim, Hyun Jung
2015-01-01
The world's demand for energy is increasing dramatically, but the best energy conversion systems operate at approximately 30% efficiency. One way to decrease energy loss is in the recovery of waste heat using thermoelectric (TE) generators. A TE generator is device that generates electricity by exploiting heat flow across a thermal gradient. The efficiency of a TE material for power generation and cooling is determined by the dimensionless Figure of Merit (ZT): ZT = S(exp. 2)sigmaT/?: where S is the Seebeck coefficient, sigma is the electrical conductivity, T is the absolute temperature, and ? is the thermal conductivity. The parameters are not physically independent, but intrinsically coupled since they are a function of the transport properties of electrons. Traditional research on TE materials has focused on synthesizing bulk semiconductor-type materials that have low thermal conductivity and high electrical conductivity affording ZT values of 1. The optimization of the s/? ratio is difficult to achieve using current material formats, as these material constants are complementary. Recent areas of research are focusing on using nanostructural artifacts that introduce specific dislocations and boundary conditions that scatter the phonons. This disrupts the physical link between thermal (phonon) and electrical (electron) transport. The result is that ? is decreased without decreasing s. These material formats give ZT values of up to 2 which represent approximately 18% energy gain from waste heat recovery. The next challenge in developing the next generation of TE materials with superior performance is to tailor the interconnected thermoelectric physical parameters of the material system. In order to approach this problem, the fundamental physics of each parameter S, sigma, and ? need to be physically understood in their context of electron/phonon interaction for the construction of new high ZT thermoelectric devices. Is it possible to overcome the physical limit
International Nuclear Information System (INIS)
Heuristic arguments are given that the C-, T-violating resonant electroexcitation amplitudes in the second resonance region are approx. (R/subK//R/subJ/) times the C-, T-conserving amplitudes, where R/subK/ (R/subJ/) is a typical interaction radius for the C-, T-violating (conserving) electromagnetic interaction. This result allows the use of an existing amplitude analysis in order to estimate that the expected Christ-Lee asymmetry in this energy region should be about (R/subK//R/subJ/) times (30 to 40 %) for q2 ma -0.5 (GeV/c)2. The experimental upper bound ( ma 2%) then gives a bound R/subK//R/subJ/ 0 decay asymmetries. This result is also in agreement with the bound R/subK//R/subJ/ approximately-less-than 1/20 obtained by previous authors in a dispersive calculation of the electric dipole moment of the neutron. Such small radii are shown to have unfavorable implications for the theory, and these are briefly discussed
A limit load analysis of RBMK-1500 reactor structures
International Nuclear Information System (INIS)
Presented is a mathematical model of Ignalina NPP facilities where the transported hermetic containers CASTOR RBMK will be located. Analysis of the mathematical model provides resultant stresses caused by free falling container with spent fuel. The result yield wall deflections and maximum stresses in the reinforcing bars of the structure, which maintains the integrity of these facilities of the Ignalina NPP. They indicate the excessive deflections of the walls and stresses in reinforcement in certain areas of the facilities. The ALGOR computer code is used for the calculation. (author). 3 figs., 6 refs
International Nuclear Information System (INIS)
Limit analysis approaches are widely used to deal with metalworking processes analysis; however, they are applied only for perfectly plastic materials and recently for isotropic hardening ones excluding any kind of kinematic hardening. In the present work, using Implicit Standard Materials concept, sequential limit analysis approach and the finite element method, our objective consists in extending the limit analysis application for including linear and non linear kinematic strain hardenings. Because this plastic flow rule is non associative, the Implicit Standard Materials concept is adopted as a framework of non standard plasticity modeling. The sequential limit analysis procedure which considers the plastic behavior with non linear kinematic strain hardening as a succession of perfectly plastic behavior with yielding surfaces updated after each sequence of limit analysis and geometry updating is applied. Standard kinematic finite element method together with a regularization approach is used for performing two large compression cases (cold forging) in plane strain and axisymmetric conditions
Energy Technology Data Exchange (ETDEWEB)
Milani, Gabriele, E-mail: milani@stru.polimi.it; Valente, Marco, E-mail: milani@stru.polimi.it [Department of Architecture, Built Environment and Construction Engineering (ABC), Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan (Italy)
2014-10-06
This study presents some results of a comprehensive numerical analysis on three masonry churches damaged by the recent Emilia-Romagna (Italy) seismic events occurred in May 2012. The numerical study comprises: (a) pushover analyses conducted with a commercial code, standard nonlinear material models and two different horizontal load distributions; (b) FE kinematic limit analyses performed using a non-commercial software based on a preliminary homogenization of the masonry materials and a subsequent limit analysis with triangular elements and interfaces; (c) kinematic limit analyses conducted in agreement with the Italian code and based on the a-priori assumption of preassigned failure mechanisms, where the masonry material is considered unable to withstand tensile stresses. All models are capable of giving information on the active failure mechanism and the base shear at failure, which, if properly made non-dimensional with the weight of the structure, gives also an indication of the horizontal peak ground acceleration causing the collapse of the church. The results obtained from all three models indicate that the collapse is usually due to the activation of partial mechanisms (apse, façade, lateral walls, etc.). Moreover the horizontal peak ground acceleration associated to the collapse is largely lower than that required in that seismic zone by the Italian code for ordinary buildings. These outcomes highlight that structural upgrading interventions would be extremely beneficial for the considerable reduction of the seismic vulnerability of such kind of historical structures.
International Nuclear Information System (INIS)
This study presents some results of a comprehensive numerical analysis on three masonry churches damaged by the recent Emilia-Romagna (Italy) seismic events occurred in May 2012. The numerical study comprises: (a) pushover analyses conducted with a commercial code, standard nonlinear material models and two different horizontal load distributions; (b) FE kinematic limit analyses performed using a non-commercial software based on a preliminary homogenization of the masonry materials and a subsequent limit analysis with triangular elements and interfaces; (c) kinematic limit analyses conducted in agreement with the Italian code and based on the a-priori assumption of preassigned failure mechanisms, where the masonry material is considered unable to withstand tensile stresses. All models are capable of giving information on the active failure mechanism and the base shear at failure, which, if properly made non-dimensional with the weight of the structure, gives also an indication of the horizontal peak ground acceleration causing the collapse of the church. The results obtained from all three models indicate that the collapse is usually due to the activation of partial mechanisms (apse, façade, lateral walls, etc.). Moreover the horizontal peak ground acceleration associated to the collapse is largely lower than that required in that seismic zone by the Italian code for ordinary buildings. These outcomes highlight that structural upgrading interventions would be extremely beneficial for the considerable reduction of the seismic vulnerability of such kind of historical structures
An improved cosmological bound on the thermal axion mass
Melchiorri, Alessandro; Mena Requejo, Olga; Slosar, Anze
2007-01-01
Relic thermal axions could play the role of an extra hot dark matter component in cosmological structure formation theories. By combining the most recent observational data we improve previous cosmological bounds on the axion mass m(a) in the so-called hadronic axion window. We obtain a limit on the axion mass m(a)< 0.42 eV at the 95% C.L. (m(a)< 0.72 eV at the 99% C.L.). A novel aspect of the analysis presented here is the inclusion of massive neutrinos and how they may affect the bound on t...
Energy Technology Data Exchange (ETDEWEB)
Gabrys, Charles M.; Yang Jun; Weliky, David P. [Michigan State University, Department of Chemistry (United States)], E-mail: weliky@cem.msu.edu
2003-05-15
2D slow-spinning, rotor-synchronized MAS exchange spectroscopy (SSRS-MASE) was applied to study local secondary structure of three structurally different peptides, two of which were membrane-bound. Each peptide was {sup 13}C carbonyl labeled at two adjacent residues in the peptide backbone. In general, this methodology is attractive for membrane-bound peptides because of its lenient spinning, decoupling, and RF homogeneity requirements.For a single set of raw SSRS-MASE data, two linearly independent methods exist for obtaining a 2D spectrum and each spectrum can be fit to obtain conformational constraints. An approach is described for combining the results of these two fits and this method is shown to work for spectra with both resolved and unresolved labeled site resonances. A spectrum is often fit well to a few different conformations which have somewhat different values of the fitting parameter {chi}{sup 2}. A simple statistical theory is developed which relates the {delta}{chi}{sup 2} difference between a local minimum and the global minimum {chi}{sup 2} to the likelihood that the local minimum conformation is the correct structure. Because uncertainty in the simulated data can also contribute to the overall fitting uncertainty, an empirical method is described for incorporating the simulation uncertainty into the {delta}{chi}{sup 2} analysis.These data analysis methods were tested on polycrystalline Ala-Gly-Gly and then applied to the membrane-bound melittin and HIV-1 fusion peptides. Melittin gave a best-fit {alpha} helical structure at Ala-4 while the fusion peptide gave a good-fit {beta} strand structure at Phe-8. The melittin analysis is in agreement with the known overall structure of this peptide.
International Nuclear Information System (INIS)
2D slow-spinning, rotor-synchronized MAS exchange spectroscopy (SSRS-MASE) was applied to study local secondary structure of three structurally different peptides, two of which were membrane-bound. Each peptide was 13C carbonyl labeled at two adjacent residues in the peptide backbone. In general, this methodology is attractive for membrane-bound peptides because of its lenient spinning, decoupling, and RF homogeneity requirements.For a single set of raw SSRS-MASE data, two linearly independent methods exist for obtaining a 2D spectrum and each spectrum can be fit to obtain conformational constraints. An approach is described for combining the results of these two fits and this method is shown to work for spectra with both resolved and unresolved labeled site resonances. A spectrum is often fit well to a few different conformations which have somewhat different values of the fitting parameter χ2. A simple statistical theory is developed which relates the Δχ2 difference between a local minimum and the global minimum χ2 to the likelihood that the local minimum conformation is the correct structure. Because uncertainty in the simulated data can also contribute to the overall fitting uncertainty, an empirical method is described for incorporating the simulation uncertainty into the Δχ2 analysis.These data analysis methods were tested on polycrystalline Ala-Gly-Gly and then applied to the membrane-bound melittin and HIV-1 fusion peptides. Melittin gave a best-fit α helical structure at Ala-4 while the fusion peptide gave a good-fit β strand structure at Phe-8. The melittin analysis is in agreement with the known overall structure of this peptide
Space-bounded communication complexity
DEFF Research Database (Denmark)
Brody, Joshua Eric; Chen, Shiteng; Papakonstantinou, Periklis A.;
2013-01-01
In the past thirty years, Communication Complexity has emerged as a foundational tool to proving lower bounds in many areas of computer science. Its power comes from its generality, but this generality comes at a price---no superlinear communication lower bound is possible, since a player may...... communicate his entire input. However, what if the players are limited in their ability to recall parts of their interaction? We introduce memory models for 2-party communication complexity. Our general model is as follows: two computationally unrestricted players, Alice and Bob, each have s(n) bits of memory...
International Nuclear Information System (INIS)
Scattering of a particle by bound nucleons is discussed. Effects of nucleons that are bound in a nucleus are taken as a structure function. The way how to calculate the structure function is given. (author)
A flow calculus of mwp-bounds for complexity analysis
DEFF Research Database (Denmark)
Jones, Neil D.; Kristiansen, Lars
2010-01-01
We present a method for certifying that the values computed by an imperative program will be bounded by polynomials in the program's inputs. To this end, we introduce mwp-matrices and define a semantic relation ⊧ C : M, where C is a program and M is an mwp-matrix. It follows...... : M is the bottom line. We prove that ⊢ C : M implies ⊧ C : M. By means of exhaustive proof search, an algorithm can decide if there exists M such that the relation ⊢ C : M holds, and thus, our results yield a computational method....
International Nuclear Information System (INIS)
Energy harvesting from human motion addresses the growing need for battery-free health and wellness sensors in wearable applications. The major obstacles to harvesting energy in such applications are low and random frequencies due to the nature of human motion. This paper presents a generalized rotational harvester model in 3 dimensions to determine the upper bound of power output from real world measured data. Simulation results indicate much space for improvement on power generation comparing to existing devices. We have developed a rotational energy harvester for human motion that attempts to close the gap between theoretical possibility and demonstrated devices. Like previous work, it makes use of magnetically plucked piezoelectric beams. However, it more fully utilizes the space available and has many degrees of freedom available for optimization. Finally we present a prototype harvester based on the coupled harvester model with preliminary experimental validation
Tanavalee, Chotetawan; Luksanapruksa, Panya; Singhatanadgige, Weerasak
2016-06-01
Microsoft Excel (MS Excel) is a commonly used program for data collection and statistical analysis in biomedical research. However, this program has many limitations, including fewer functions that can be used for analysis and a limited number of total cells compared with dedicated statistical programs. MS Excel cannot complete analyses with blank cells, and cells must be selected manually for analysis. In addition, it requires multiple steps of data transformation and formulas to plot survival analysis graphs, among others. The Megastat add-on program, which will be supported by MS Excel 2016 soon, would eliminate some limitations of using statistic formulas within MS Excel. PMID:27135620
Conductivity bounds in probe brane models
Ikeda, Tatsuhiko N; Nakai, Yuichiro
2016-01-01
We discuss upper and lower bounds on the electrical conductivity of finite temperature strongly coupled quantum field theories, holographically dual to probe brane models, within linear response. In a probe limit where disorder is introduced entirely through an inhomogeneous background charge density, we find simple lower and upper bounds on the electrical conductivity in arbitrary dimensions. In field theories in two spatial dimensions, we show that both bounds persist even when disorder is included in the bulk metric. We discuss the challenges with finding sharp lower bounds on conductivity in three or more spatial dimensions when the metric is inhomogeneous.
Ladenson, Robert F.
2011-01-01
This article presents a moral analysis of the limitations upon legitimate authority to suspend and expel students in K-12 public schools, and it brings this analysis to bear on a pair of difficult disciplinary cases. The analysis is grounded in a defense of a child's right to receive a public education. It identifies the minimum content of that…
Financial Planning and Financial Analysis of a Limited Liability Company
Strebeľová, Veronika
2011-01-01
Composition of financial plan for year 2012 and executing financial analysis of a limited liability company. In composition of financial plan were used three variant -- an optimistic, a realistic and a pesimistic. Used methods of financial analysis were analysis of absolute indicators and financial ratios, including logaritmical decomposition of Return on Equity. Comparing each of those variants with reality valid on May 31, 2012.
Institute of Scientific and Technical Information of China (English)
Weiguo ZHANG; Qiang LIU; Xiang LI; Boling GUO
2012-01-01
This paper deals with the problem of the bounded traveling wave solutions'shape and the solution to the generalized Whitham-Broer-Kaup equation with the dissipation terms which can be called WBK equation for short.The authors employ the theory and method of planar dynamical systems to make comprehensive qualitative analyses to the above equation satisfied by the horizontal velocity component u(ξ) in the traveling wave solution (u(ξ),H(ξ)),and then give its global phase portraits.The authors obtain the existent conditions and the number of the solutions by using the relations between the components u(ξ) and H(ξ) in the solutions.The authors study the dissipation effect on the solutions,find out a critical value r*,and prove that the traveling wave solution (u(ξ),H(ξ)) appears as a kink profile solitary wave if the dissipation effect is greater,i.e.,|r| ≥ r*,while it appears as a damped oscillatory wave if the dissipation effect is smaller,i.e.,|r| r*.Two solitary wave solutions to the WBK equation without dissipation effect is also obtained.Based on the above discussion and according to the evolution relations of orbits corresponding to the component u(ξ) in the global phase portraits,the authors obtain all approximate damped oscillatory solutions ((u)(ξ),(H)(ξ)) under various conditions by using the undetermined coefficients method. Finally,the error between the approximate damped oscillatory solution and the exact solution is an infinitesimal decreasing exponentially.
Directory of Open Access Journals (Sweden)
Guenter Goerigk
2016-03-01
Full Text Available Anomalous small angle scattering measurements have been applied to diluted solutions of anionic polyacrylates decorated by specifically-interacting Pb2+ cations, revealing partial collapse of the polyacrylate into pearl-like subdomains with a size on the order of a few nanometers. From the pure-resonant scattering contribution of the Pb2+ cations, and from subsequent analysis of the resonant-invariant, the amount of Pb2+ cations condensed onto the polyanions with respect to the total amount of Pb2+ cations in the solvent was estimated. In order to scrutinize systematic limitations in the determination of the chemical concentrations of resonant scattering counterions in the collapsed phase, Monte Carlo simulations have been performed. The simulations are based on structural confinements at variable size in the range of few nanometers, which represent the collapsed subdomains in the polyanions. These confinements were gradually filled to a high degree of the volume fraction with resonant scattering counterions giving access to a resonant-invariant at a variable degree of filling. The simulations revealed in the limit of small structures a significant underestimation of the true degree of filling of the collapsed subdomains when determining chemical concentrations of Pb2+ cations from the resonant invariant.
Shivanandan, Arun; Unnikrishnan, Jayakrishnan; RADENOVIC, Aleksandra
2015-01-01
Single Molecule Localization Microscopy techniques like PhotoActivated Localization Microscopy, with their sub-diffraction limit spatial resolution, have been popularly used to characterize the spatial organization of membrane proteins, by means of quantitative cluster analysis. However, such quantitative studies remain challenged by the techniques' inherent sources of errors such as a limited detection efficiency of less than 60%, due to incomplete photo-conversion, and a limited localizatio...
Determination of detection limits for a VPD ICPMS method of analysis
International Nuclear Information System (INIS)
This training course report presents the different methods of detection and quantifying of metallic impurities in semiconductors. One of the most precise technique is the collection of metal impurities by vapor phase decomposition (VPD) followed by their analysis by ICPMS (inductively coupled plasma mass spectrometry). The study shows the importance of detection limits in the domain of chemical analysis and the way to determine them for the ICPMS analysis. The results found on detection limits are excellent. Even if the detection limits reached with ICPMS performed after manual or automatic VPD are much higher than detection limits of ICPMS alone, this method remains one of the most sensible for ultra-traces analysis. (J.S.)
Volume bounds of conic 2-spheres
Fang, Hao; Lai, Mijia
2016-01-01
We obtain sharp volume bound for a conic 2-sphere in terms of its Gaussian curvature bound. We also give the geometric models realizing the extremal volume. In particular, when the curvature is bounded in absolute value by $1$, we compute the minimal volume of a conic sphere in the sense of Gromov. In order to apply the level set analysis and iso-perimetric inequality as in our previous works, we develop some new analytical tools to treat regions with vanishing curvature.
Tang, D. Y.; B. Zhao; Shen, D. Y.; Lu, C.
2009-01-01
Experimental study on the soliton dynamics of a passively mode locked fiber ring laser firstly revealed a state of bound soliton operation in the laser, where two solitons bind together tightly with fixed pulse separation. We further report on the properties of the bound-soliton emission of the laser. In particular, we demonstrate both experimentally and numerically that, like the single pulse soliton operation of the laser, the bound soliton emission is another intrinsic feature of the laser.
Takahashi, Ikuko; Miyamoto, Junko; Hasegawa, Yukihiro
2006-01-01
Mixed gonadal dysgenesis (MGD) is an abnormal sexual differentiation syndrome usually presenting with ambiguous genitalia. Karyotype analysis is one of the essential components in the diagnosis of MGD and is conventionally done with peripheral lymphocytes by the G-banding technique. It is speculated that this conventional karyotype analysis has limitations since there are often difference in gonadal tissue analysis. Here we present four cases of MGD, in which karyotype analysis were performed...
International Nuclear Information System (INIS)
The responses and limit cycle flutter of a plate-type structure with cubic stiffness in viscous flow were studied. The continuous system was dispersed by utilizing Galerkin Method. The equivalent linearization concept was performed to predict the ranges of limit cycle flutter velocities. The coupled map of flutter amplitude-equivalent linear stiffness-critical velocity was used to analyze the stability of limit cycle flutter. The theoretical results agree well with the results of numerical integration, which indicates that the equivalent linearization concept is available to the analysis of limit cycle flutter of plate-type structure. (authors)
Fuzzy analysis of serviceability limit state of slender steel beam under bending
Energy Technology Data Exchange (ETDEWEB)
Kala, Zdeněk; Valeš, Jan [Brno University of Technology, Faculty of Civil Engineering, Department of Structural Mechanics Vevefi St. 95, ZIP 602 00, Brno (Czech Republic)
2015-03-10
In the present paper, deformations of a beam under equal end moments solved with influence of lateral buckling are studied. It has been found by numerical studies that the lateral deflection of slender beam under major axis bending can be relatively high.The acceptability of high values of lateral deflections within the framework of serviceability limit state is discussed. In the next part of the paper, the limit value of maximum deflection was introduced as a fuzzy number. The fuzzy analysis of the maximum moment which causes the maximum deflection was carried out. The slendernesses of beams for which the serviceability limit state is the limiting state for design were identified.
Directory of Open Access Journals (Sweden)
Fatemeh Zahra Nazari Robati
2016-03-01
Full Text Available Today TS focus has altered from linguistics to cultural studies. Culture is the way of life; as such every text is culture-bound and includes items that are culture-specific. Translating these cultural-specific items (henceforth CSI has made translation a complicated task. Hijab, one of the controversial issues of the present day of Islam in the world is defined in one way through presenting terms for women clothing such as “Jilbab” in Quran. Using Davies' (2003 strategies of translating CSIs, as the theoretical framework, taking the Quranic-Arabic culture bound term “Jilbab” (33:59 as the object of the study, this corpus-based comparative descriptive research was an attempt to compare totally 64 Persian and English (54 in Persian and 12 in English translations of this term with two concerns regarding the adopted translation strategies: a linguistic (Persian and English concern, and b translators' gender concern (male and female. The analysis of data showed that the most adopted strategy in both Persian and English corpus was localization (in Persian 35.71%, and in English 46.66%. Male translators in Persian had more tendency to use localization (36.53% and female translators to addition and globalization (each 50%. Male translators in English were more inclined to localization (45.83%, and the female have used preservation, addition, globalization and localization with the same frequency (25%. Totally male translators were inclined to localization (39.47%, while the female to globalization and addition (33.33%.Keywords: CSI, Translation strategies, Comparative analysis, Quran, “Jilbab”
Bounded Gaussian process regression
DEFF Research Database (Denmark)
Jensen, Bjørn Sand; Nielsen, Jens Brehm; Larsen, Jan
2013-01-01
We extend the Gaussian process (GP) framework for bounded regression by introducing two bounded likelihood functions that model the noise on the dependent variable explicitly. This is fundamentally different from the implicit noise assumption in the previously suggested warped GP framework. We...
43 CFR 46.160 - Limitations on actions during the NEPA analysis process.
2010-10-01
... analysis process. 46.160 Section 46.160 Public Lands: Interior Office of the Secretary of the Interior... Quality § 46.160 Limitations on actions during the NEPA analysis process. During the preparation of a... accordance with 40 CFR 1506.1 when that action is within the scope of, and analyzed in, an existing...
Consumer choice and revealed bounded rationality
Manzini, Paola; Mariotti, Marco
2006-01-01
We study two boundedly rational procedures in consumer behavior. We show that these procedures can be detected by conditions on observable demand data of the same type as standard revealed preference axioms. This provides the basis for a non-parametric analysis of boundedly rational consumer behavior mirroring the classical one for utility maximization.
de Rham, Claudia; Tolley, Andrew J; Zhou, Shuang-Yong
2016-01-01
Recently, aLIGO has announced the first direct detections of gravitational waves, a direct manifestation of the propagating degrees of freedom of gravity. The detected signals GW150914 and GW151226 have been used to examine the basic properties of these gravitational degrees of freedom, particularly setting an upper bound on their mass. It is timely to review what the mass of these gravitational degrees of freedom means from the theoretical point of view, particularly taking into account the recent developments in constructing consistent massive gravity theories. Apart from the GW150914 mass bound, a few other observational bounds have been established from the effects of the Yukawa potential, modified dispersion relation and fifth force that are all induced when the fundamental gravitational degrees of freedom are massive. We review these different mass bounds and examine how they stand in the wake of recent theoretical developments and how they compare to the bound from GW150914.
Drude weight and Mazur-Suzuki bounds in holography
García-García, Antonio M.; Romero-Bermúdez, Aurelio
2016-03-01
We investigate the Drude weight and the related Mazur-Suzuki (MS) bound in a broad variety of strongly coupled field theories with a gravity dual at finite temperature and chemical potential. We revisit the derivation of the recently proposed universal expression for the Drude weight for Einstein-Maxwell-dilaton (EMd) theories and extend it to the case of theories with multiple massless gauge fields. We show that the MS bound, which in the context of condensed matter provides information on the integrability of the theory, is saturated in these holographic theories including R-charged backgrounds. We then explore the limits of this universality by studying EMd theories with U (1 ) spontaneous symmetry breaking and gravity duals of nonrelativistic field theories including an asymptotically Lifshitz EMd model with two massless gauge fields and the Einstein-Proca model. In all these cases, the Drude weight, computed analytically, deviates from the universal result and the MS bound is not saturated. In general, it is not possible to deduce the low temperature dependence of the Drude weight by simple dimensional analysis. Finally, we study the effect of a weak breaking of translational symmetry by coupling the EMd action, with and without U (1 ) spontaneous symmetry breaking, to an axion field. We show that the coherent part of the conductivity in this limit is simply the product of the MS bound and the scattering time obtained from the leading quasinormal mode. For asymptotically AdS theories it seems that the MS bound sets a lower bound on the dc conductivity for a given scattering time.
Analysis of ASME Class 1 piping system supported by limit stops
International Nuclear Information System (INIS)
A snubber elimination analysis was undertaken for the bypass line of loop 4 of the Reactor Coolant System at the Byron-2 Nuclear Station using seismic response spectra based on ASME Code Case N-411 damping values. The analysis considered the replacement of existing snubbers with Limit Stops, which are passive displacement limiting pipe supports developed by Robert L. Cloud and Associates, Inc. and sponsored, in part, by the Electric Power Research Institute. The analysis was conducted with the GAPPIPE computer program. GAPPIPE was developed specifically for analyzing piping systems with nonlinearities such as gapped supports using the response spectrum method. The analysis concluded that all thirteen snubbers on the system could be eliminated, to be replaced by eight Limit Stop supports. ASME Class 1 Code rules were satisfied, as well as numerous other criteria imposed by the plant design specifications
Dipole Moment Bounds on Scalar Dark Matter Annihilation
Fukushima, Keita
2013-01-01
We consider a scalar dark matter annihilations to light leptons mediated by charged exotic fermions. The interaction of this model also adds a correction to dipole moments of light leptons. In the simplified model, these processes will depend upon the same coupling constants. The tight experimental bounds on the dipole moments of light leptons will constrain the coupling constants. Consequently, this bound will then limit the annihilations. We will produce this dipole moment bounds on the annihilation. From this analysis, we report that the bound on annihilation to the electrons is $4.0\\times10^{-7}\\pb$ (g-2) + $8.8\\times 10^{-15}\\pb$ (EDM) and the muons is $5.6\\times 10^{-4}\\pb$ (g-2) + $180\\pb$ (EDM), in the limit where the mediator is much heavier than dark matter. The parentheses indicate the dipole moment used to obtain the values. We note that only the annihilation to muons through a CP-violating (EDM) coupling is not excluded from indirect detection experiments.
International Nuclear Information System (INIS)
The standard method of pionic atom formation does not produce deeply bound pionic atoms. A study is made on the properties of deeply bound pionic atom states by using the standard pion-nucleus optical potential. Another study is made to estimate the cross sections of the formation of ls pionic atom states by various methods. The pion-nucleus optical potential is determined by weakly bound pionic atom states and pion nucleus scattering. Although this potential may not be valid for deeply bound pionic atoms, it should provide some hint on binding energies and level widths of deeply bound states. The width of the ls state comes out to be 0.3 MeV and is well separated from the rest. The charge dependence of the ls state is investigated. The binding energies and the widths increase linearly with Z azbove a Z of 30. The report then discusses various methods to populate deeply bound pionic atoms. In particular, 'pion exchange' reactions are proposed. (n, pπ) reaction is discussed first. The cross section is calculated by assuming the in- and out-going nucleons on-shell and the produced pion in (n1) pionic atom states. Then, (n, dπ-) cross sections are estimated. (p, 2Heπ-) reaction would have cross sections similar to the cross section of (n, dπ-) reaction. In conclusion, it seems best to do (n, p) experiment on heavy nuclei for deeply bound pionic atom. (Nogami, K.)
Pisano, Aurora; Weichert, Dieter
2015-01-01
Articles in this book examine various materials and how to determine directly the limit state of a structure, in the sense of limit analysis and shakedown analysis. Apart from classical applications in mechanical and civil engineering contexts, the book reports on the emerging field of material design beyond the elastic limit, which has further industrial design and technological applications. Readers will discover that “Direct Methods” and the techniques presented here can in fact be used to numerically estimate the strength of structured materials such as composites or nano-materials, which represent fruitful fields of future applications. Leading researchers outline the latest computational tools and optimization techniques and explore the possibility of obtaining information on the limit state of a structure whose post-elastic loading path and constitutive behavior are not well defined or well known. Readers will discover how Direct Methods allow rapid and direct access to requested information in...
Generalized Sphere Packing Bound
Fazeli, Arman; Vardy, Alexander; Yaakobi, Eitan
2014-01-01
Kulkarni and Kiyavash recently introduced a new method to establish upper bounds on the size of deletion-correcting codes. This method is based upon tools from hypergraph theory. The deletion channel is represented by a hypergraph whose edges are the deletion balls (or spheres), so that a deletion-correcting code becomes a matching in this hypergraph. Consequently, a bound on the size of such a code can be obtained from bounds on the matching number of a hypergraph. Classical results in hyper...
Shen, Simon; Syal, Karan; Tao, Nongjian; Wang, Shaopeng
2015-12-01
We present a Single-Cell Motion Characterization System (SiCMoCS) to automatically extract bacterial cell morphological features from microscope images and use those features to automatically classify cell motion for rod shaped motile bacterial cells. In some imaging based studies, bacteria cells need to be attached to the surface for time-lapse observation of cellular processes such as cell membrane-protein interactions and membrane elasticity. These studies often generate large volumes of images. Extracting accurate bacterial cell morphology features from these images is critical for quantitative assessment. Using SiCMoCS, we demonstrated simultaneous and automated motion tracking and classification of hundreds of individual cells in an image sequence of several hundred frames. This is a significant improvement from traditional manual and semi-automated approaches to segmenting bacterial cells based on empirical thresholds, and a first attempt to automatically classify bacterial motion types for motile rod shaped bacterial cells, which enables rapid and quantitative analysis of various types of bacterial motion. PMID:26724085
Shen, Simon; Syal, Karan; Tao, Nongjian; Wang, Shaopeng
2015-12-01
We present a Single-Cell Motion Characterization System (SiCMoCS) to automatically extract bacterial cell morphological features from microscope images and use those features to automatically classify cell motion for rod shaped motile bacterial cells. In some imaging based studies, bacteria cells need to be attached to the surface for time-lapse observation of cellular processes such as cell membrane-protein interactions and membrane elasticity. These studies often generate large volumes of images. Extracting accurate bacterial cell morphology features from these images is critical for quantitative assessment. Using SiCMoCS, we demonstrated simultaneous and automated motion tracking and classification of hundreds of individual cells in an image sequence of several hundred frames. This is a significant improvement from traditional manual and semi-automated approaches to segmenting bacterial cells based on empirical thresholds, and a first attempt to automatically classify bacterial motion types for motile rod shaped bacterial cells, which enables rapid and quantitative analysis of various types of bacterial motion.
Duyck, Dieter; Capirone, Daniele; Moeneclaey, Marc
2012-01-01
Joint network-channel codes (JNCC) can improve the performance of communication in wireless networks, by combining, at the physical layer, the channel codes and the network code as an overall error-correcting code. JNCC is increasingly proposed as an alternative to a standard layered construction, such as the OSI-model. The main performance metrics for JNCCs are scalability to larger networks and error rate. The diversity order is one of the most important parameters determining the error rate. The literature on JNCC is growing, but a rigorous diversity analysis is lacking, mainly because of the many degrees of freedom in wireless networks, which makes it very hard to prove general statements on the diversity order. In this paper, we consider a network with slowly varying fading point-to-point links, where all sources also act as relay and additional non-source relays may be present. We propose a general structure for JNCCs to be applied in such network. In the relay phase, each relay transmits a linear trans...
International Nuclear Information System (INIS)
Since the 9-11 attacks, the United States has increased its focus on developing technologies designed to warn us in the event of another attack and to prevent these attacks from happening in the first place. The SensorNet research group at Oak Ridge National Laboratory's (ORNL) Computer Science and Engineering Division is participating in this effort by developing systems to give critical real-time information to federal, state, and local emergency response decision makers. SensorNet has approached this goal by putting together a system with several sensors and programs called the Southeastern Transportation Corridor Pilot project (SETCP). The SETCP utilizes interstate weigh stations not only to weigh the passing trucks but also to check for gamma and neutron radiation inside the truck without the aid of a human in close proximity. The system also collects additional data that help identify the truck (the truck's length, weight, license plate number, and photographs of the truck). The objective of this research work was to characterize and analyze the data collected from the South Carolina weigh station on I-26W and compare it with previous data analysis on the performance of the Tennessee weigh station on I-40E. The purpose was to find patterns in the trucks with radioactive alarms and, regional truck traffic, as well as to find patterns of inconsistency in the system (illogical length measurements of the truck, inaccurate readings and character recognition of the license plate). During a three-month period, radioactive alarms and traffic patterns were identified and characterized by grouping all of the data and making graphs and charts in Microsoft Excel to show the flow of traffic, the type of truck traffic, the number of alarms and other information. Inconsistence patterns were found by analyzing the data, looking for missing or illogical information, and determining how often it happens. The improvements of these inconsistencies were also analyzed after
Genome-wide RIP-Chip analysis of translational repressor-bound mRNAs in the Plasmodium gametocyte
Guerreiro, Ana
2014-11-03
Background Following fertilization, the early proteomes of metazoans are defined by the translation of stored but repressed transcripts; further embryonic development relies on de novo transcription of the zygotic genome. During sexual development of Plasmodium berghei, a rodent model for human malaria species including P. falciparum, the stability of repressed mRNAs requires the translational repressors DOZI and CITH. When these repressors are absent, Plasmodium zygote development and transmission to the mosquito vector is halted, as hundreds of transcripts become destabilized. However, which mRNAs are direct targets of these RNA binding proteins, and thus subject to translational repression, is unknown. Results We identify the maternal mRNA contribution to post-fertilization development of P. berghei using RNA immunoprecipitation and microarray analysis. We find that 731 mRNAs, approximately 50% of the transcriptome, are associated with DOZI and CITH, allowing zygote development to proceed in the absence of RNA polymerase II transcription. Using GFP-tagging, we validate the repression phenotype of selected genes and identify mRNAs relying on the 5′ untranslated region for translational control. Gene deletion reveals a novel protein located in the ookinete crystalloid with an essential function for sporozoite development. Conclusions Our study details for the first time the P. berghei maternal repressome. This mRNA population provides the developing ookinete with coding potential for key molecules required for life-cycle progression, and that are likely to be critical for the transmission of the malaria parasite from the rodent and the human host to the mosquito vector.
International Nuclear Information System (INIS)
We discuss the structure and formation of deeply bound π- states in heavy nuclei, which are expected to be narrow due to the repulsive π--nucleus interaction. Possible experiments to produce those states are described. (author)
Energy Technology Data Exchange (ETDEWEB)
Badard, M.; Veillerot, M
2007-07-01
This training course report presents the different methods of detection and quantifying of metallic impurities in semiconductors. One of the most precise technique is the collection of metal impurities by vapor phase decomposition (VPD) followed by their analysis by ICPMS (inductively coupled plasma mass spectrometry). The study shows the importance of detection limits in the domain of chemical analysis and the way to determine them for the ICPMS analysis. The results found on detection limits are excellent. Even if the detection limits reached with ICPMS performed after manual or automatic VPD are much higher than detection limits of ICPMS alone, this method remains one of the most sensible for ultra-traces analysis. (J.S.)
The neural basis of bounded rational behavior
Coricelli, Giorgio; Nagel, Rosemarie
2010-01-01
Bounded rational behaviour is commonly observed in experimental games and in real life situations. Neuroeconomics can help to understand the mental processing underlying bounded rationality and out-of-equilibrium behaviour. Here we report results from recent studies on the neural basis of limited steps of reasoning in a competitive setting —the beauty contest game. We use functional magnetic resonance imaging (fMRI) to study the neural correlates of human mental processes in strategic games. ...
International Nuclear Information System (INIS)
Purpose: The purpose of this study was to investigate the effect of excitation, fat saturation, long T2 saturation, and adiabatic inversion pulses on ultrashort echo time (UTE) imaging with bicomponent analysis of bound and free water in cortical bone for potential applications in osteoporosis. Methods: Six bovine cortical bones and six human tibial midshaft samples were harvested for this study. Each bone sample was imaged with eight sequences using 2D UTE imaging at 3T with half and hard excitation pulses, without and with fat saturation, long T2 saturation, and adiabatic inversion recovery (IR) preparation pulses. Single- and bicomponent signal models were utilized to calculate the T2*s and/or relative fractions of short and long T2*s. Results: For all bone samples UTE T2* signal decay showed bicomponent behavior. A higher short T2* fraction was observed on UTE images with hard pulse excitation compared with half pulse excitation (75.6% vs 68.8% in bovine bone, 79.9% vs 73.2% in human bone). Fat saturation pulses slightly reduced the short T2* fraction relative to regular UTE sequences (5.0% and 2.0% reduction, respectively, with half and hard excitation pulses for bovine bone, 6.3% and 8.2% reduction, respectively, with half and hard excitation pulses for human bone). Long T2 saturation pulses significantly reduced the long T2* fraction relative to regular UTE sequence (18.9% and 17.2% reduction, respectively, with half and hard excitation pulses for bovine bone, 26.4% and 27.7% reduction, respectively, with half and hard excitation pulses for human bone). With IR-UTE preparation the long T2* components were significantly reduced relative to regular UTE sequence (75.3% and 66.4% reduction, respectively, with half and hard excitation pulses for bovine bone, 87.7% and 90.3% reduction, respectively, with half and hard excitation pulses for human bone). Conclusions: Bound and free water T2*s and relative fractions can be assessed using UTE bicomponent analysis
Energy Technology Data Exchange (ETDEWEB)
Li, Shihong [Department of Radiology, University of California, San Diego, California 92103-8226 (United States); Department of Radiology, Hua Dong Hospital, Fudan University, Shanghai 200040 (China); Yancheng Medical College, Jiangsu (China); The First People' s Hospital of Yancheng City, Jiangsu 224005 (China); Chang, Eric Y.; Chung, Christine B. [VA San Diego Healthcare System, San Diego, California 92161 and Department of Radiology, University of California, San Diego, California 92103-8226 (United States); Bae, Won C.; Du, Jiang, E-mail: jiangdu@ucsd.edu [Department of Radiology, University of California, San Diego, California 92103-8226 (United States); Hua, Yanqing [Department of Radiology, Hua Dong Hospital, Fudan University, Shanghai 200040 (China); Zhou, Yi [The First People' s Hospital of Yancheng City, Jiangsu 224005 (China)
2014-02-15
Purpose: The purpose of this study was to investigate the effect of excitation, fat saturation, long T2 saturation, and adiabatic inversion pulses on ultrashort echo time (UTE) imaging with bicomponent analysis of bound and free water in cortical bone for potential applications in osteoporosis. Methods: Six bovine cortical bones and six human tibial midshaft samples were harvested for this study. Each bone sample was imaged with eight sequences using 2D UTE imaging at 3T with half and hard excitation pulses, without and with fat saturation, long T2 saturation, and adiabatic inversion recovery (IR) preparation pulses. Single- and bicomponent signal models were utilized to calculate the T2{sup *}s and/or relative fractions of short and long T2{sup *}s. Results: For all bone samples UTE T2{sup *} signal decay showed bicomponent behavior. A higher short T2{sup *} fraction was observed on UTE images with hard pulse excitation compared with half pulse excitation (75.6% vs 68.8% in bovine bone, 79.9% vs 73.2% in human bone). Fat saturation pulses slightly reduced the short T2{sup *} fraction relative to regular UTE sequences (5.0% and 2.0% reduction, respectively, with half and hard excitation pulses for bovine bone, 6.3% and 8.2% reduction, respectively, with half and hard excitation pulses for human bone). Long T2 saturation pulses significantly reduced the long T2{sup *} fraction relative to regular UTE sequence (18.9% and 17.2% reduction, respectively, with half and hard excitation pulses for bovine bone, 26.4% and 27.7% reduction, respectively, with half and hard excitation pulses for human bone). With IR-UTE preparation the long T2{sup *} components were significantly reduced relative to regular UTE sequence (75.3% and 66.4% reduction, respectively, with half and hard excitation pulses for bovine bone, 87.7% and 90.3% reduction, respectively, with half and hard excitation pulses for human bone). Conclusions: Bound and free water T2{sup *}s and relative fractions can
Analysis of Lithium Driven Electron Density Peaking in FTU Liquid Lithium Limiter Experiments
Szepesi, G.; Romanelli, M.; Militello, F.; Peeters, A.; Camenen, Y.; Casson, F.; Hornsby, W.; Snodin, A.; Wagner, D.
2013-01-01
The impact of lithium impurities on the microstability and turbulent transport characteristics in the core of a typical FTU Liquid Lithium Limiter (LLL)(Mazzitelli et al., Nucl. Fusion, 2011) discharge during the density ramp-up phase is studied. A non-linear gyrokinetic analysis performed with GKW (Peeters et al.,Comp. Phys. Comm., 2009) accompanied by a quasi-linear fluid analysis is presented. We show that a centrally peaked, high concentration lithium profile contributes to the electron p...
DEFF Research Database (Denmark)
Sun, Bo; Trintis, Ionut; Munk-Nielsen, Stig;
2016-01-01
online adapt its dc-link voltage reference based on the system operating state. Furthermore, the relationship between current THD, minimum pulse width limitation and Mmax index reference is analyzed in order to obtain an optimized performance of the system. Finally, the dynamic performance and analysis...
Ostertag, Rebecca; DiManno, Nicole
2016-03-01
Examining foliar nutrient concentrations after fertilization provides an alternative method for detecting nutrient limitation of ecosystems, which is logistically simpler to measure than biomass change. We present a meta-analysis of response ratios of foliar nitrogen and phosphorus (RRN, RRP) after addition of fertilizer of nitrogen (N), phosphorus (P), or the two elements in combination, in relation to climate, ecosystem type, life form, family, and methodological factors. Results support other meta-analyses using biomass, and demonstrate there is strong evidence for nutrient limitation in natural communities. However, because N fertilization experiments greatly outnumber P fertilization trials, it is difficult to discern the absolute importance of N vs. P vs. co-limitation across ecosystems. Despite these caveats, it is striking that results did not follow "conventional wisdom" that temperate ecosystems are N-limited and tropical ones are P-limited. In addition, the use of ratios of N-to-P rather than response ratios also are a useful index of nutrient limitation, but due to large overlap in values, there are unlikely to be universal cutoff values for delimiting N vs. P limitation. Differences in RRN and RRP were most significant across ecosystem types, plant families, life forms, and between competitive environments, but not across climatic variables.
Hoyer, Paul
2016-01-01
Even a first approximation of bound states requires contributions of all powers in the coupling. This means that the concept of "lowest order bound state" needs to be defined. In these lectures I discuss the "Born" (no loop, lowest order in $\\hbar$) approximation. Born level states are bound by gauge fields which satisfy the classical field equations. As a check of the method, Positronium states of any momentum are determined as eigenstates of the QED Hamiltonian, quantized at equal time. Analogously, states bound by a strong external field $A^\\mu(\\xv)$ are found as eigenstates of the Dirac Hamiltonian. Their Fock states have dynamically created $e^+e^-$ pairs, whose distribution is determined by the Dirac wave function. The linear potential of $D=1+1$ dimensions confines electrons but repels positrons. As a result, the mass spectrum is continuous and the wave functions have features of both bound states and plane waves. The classical solutions of Gauss' law are explored for hadrons in QCD. A non-vanishing bo...
Bounding species distribution models
Institute of Scientific and Technical Information of China (English)
Thomas J. STOHLGREN; Catherine S. JARNEVICH; Wayne E. ESAIAS; Jeffrey T. MORISETTE
2011-01-01
Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern.Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development,yet there is no recommended best practice for “clamping” model extrapolations.We relied on two commonly used modeling approaches:classification and regression tree (CART) and maximum entropy (Maxent) models,and we tested a simple alteration of the model extrapolations,bounding extrapolations to the maximum and minimum values of primary environmental predictors,to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States.Findings suggest that multiple models of bounding,and the most conservative bounding of species distribution models,like those presented here,should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5):642-647,2011].
Non-linear ultimate strength and stability limit state analysis of a wind turbine blade
DEFF Research Database (Denmark)
Rosemeier, Malo; Berring, Peter; Branner, Kim
2016-01-01
According to the design codes for wind turbine blades, it is sufficient to evaluate the blade's limit states using solely a linear analysis. This study, however, shows the need of non-linear analyses in blade design. Therefore, a geometrically non-linear structural response of a 34 m blade under...... flap-wise loading has been compared with a linear response to determine the blade's resistance in the ultimate strength and stability limit states. The linear analysis revealed an unrealistic failure mechanism and failure mode. Further, it did not capture the highly non-linear response of the blade...... application of an imperfection. The more realistic non-linear approaches yielded more optimistic results than the mandatory linear bifurcation analysis. Consequently, the investigated blade designed after the lesser requirements was sufficient. Using the non-linear approaches, considering inter-fibre failure...
Plastic limit load analysis for steam generator tubes with local wall-thinning
International Nuclear Information System (INIS)
This paper introduces the study of experimental and numerical analysis for plastic limit loads of Inconel 690 steam generators (SG) tubes with local wall-thinning defects. Meanwhile, the effect of the three dimensions of a local wall-thinning defect on the plastic limit load of SG tubes is analyzed. A test facility which can test both burst pressure and plastic limit load of SG tubes was established and SG tubes with 3 typical types of defects were tested by using the facility. A regularization method for local wall-thinning defect is proposed and the finite element method was used to analyze the plastic limit load of SG tubes with defects. Compared with the experimental results of SG tubes with real defects, the calculated values of plastic limit load for SG tubes with regularized defects are conservative. Based on finite element method, the effect of the three dimensions of local wall-thinning defects on plastic limit loads of defected Inconel 690 SG tubes has been got. The studied results show that the defect depth of a local wall-thinning defect is the main factor influencing the plastic limit load of SG tubes, on the other hand, both the longitudinal length and the circumferential length of a defect have effect on the plastic limit load of SG tubes. It is found that in some cases, when the longitudinal length and the circumferential angle of a local wall-thinning defect exceed some extent, the effect of the longitudinal length and the circumferential angle on plastic limit load can be ignored.
Energy Technology Data Exchange (ETDEWEB)
Warne, L.K.; Merewether, K.O.; Chen, K.C.; Jorgenson, R.E.; Morris, M.E.; Solberg, J.E.; Lewis, J.G. [Sandia National Labs., Albuquerque, NM (United States); Derr, W. [Derr Enterprises, Albuquerque, NM (United States)
1996-07-01
Test data on canonical weapon-like fixtures are used to validate previously developed analytical bounding results. The test fixtures were constructed to simulate (but be slightly worse than) weapon ports of entry but have known geometries (and electrical points of contact). The exterior of the test fixtures exhibited exterior resonant enhancement of the incident fields at the ports of entry with magnitudes equal to those of weapon geometries. The interior consisted of loaded transmission lines adjusted to maximize received energy or voltage but incorporating practical weapon geometrical constraints. New analytical results are also presented for bounding the energies associated with multiple bolt joints and for bounding the exterior resonant enhancement of the exciting fields.
Information, Utility & Bounded Rationality
Ortega, Pedro A
2011-01-01
Perfectly rational decision-makers maximize expected utility, but crucially ignore the resource costs incurred when determining optimal actions. Here we employ an axiomatic framework for bounded rational decision-making based on a thermodynamic interpretation of resource costs as information costs. This leads to a variational "free utility" principle akin to thermodynamical free energy that trades off utility and information costs. We show that bounded optimal control solutions can be derived from this variational principle, which leads in general to stochastic policies. Furthermore, we show that risk-sensitive and robust (minimax) control schemes fall out naturally from this framework if the environment is considered as a bounded rational and perfectly rational opponent, respectively. When resource costs are ignored, the maximum expected utility principle is recovered.
Peachey, Emma; Cook, Ken; Castles, Adrian; Hopley, Christopher; Goenaga-Infante, Heidi
2009-10-16
This work investigates for the first time the potential of mixed-mode (anion-exchange with reversed-phase) high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (ICP-MS) for the simultaneous retention and selective separation of a range of inorganic and organically-bound selenium (Se) species. Baseline separation and detection of selenocystine (SeCys(2)), Se-methyl-selenocysteine (SeMC), selenomethionine (SeMet), methylseleninic acid (MSA), selenite, gamma-glutamyl-methyl-selenocysteine (gamma-glutamyl-SeMC), and selenate in a Se standard mixture by mixed-mode HPLC-ICP-MS was achieved by switching between two citrate mobile phases of different pH and ionic strength within a single chromatographic run of 20 min. Limits of detection obtained for these Se species ranged from 80 ng kg(-1) (for SeMC) to 123 ng kg(-1) (for selenate). Using this approach as developed for selenium speciation, an adequate separation of inorganic and organic As compounds was also achieved. These include arsenite, arsenate, arsenobetaine (AsB) and dimethylarsenic acid (DMA), which may coexist with Se species in biological samples. Application of the newly proposed methodology to the investigation of the elemental species distribution in watercress (used as the model sample) after enzymatic hydrolysis or leaching in water by accelerated solvent extraction (ASE) was addressed. Only SeMet, SeMC and selenate could be tentatively identified in watercress extracts by mixed-mode HPLC-ICP-MS and retention time matching with standards. Recoveries (n=3) of these Se species from samples spiked with standards averaged 102% (for SeMC), 94.9% (for SeMet) and 98.3% (for selenate). Verification of the presence of SeMet and SeMC in an enzymatic watercress extract was achieved by on-line HPLC-ESI MS/MS in selected reaction monitoring (SRM) mode. PMID:19758595
Application of the limit analysis and of the reference stress method to stiffened welded structures
International Nuclear Information System (INIS)
A global method for the analysis of the failure of non elementary structures is examined. The type of failure are: instantaneous or delayed deformation, plastic instability of the material and delayed rupture. The steel structure studied is the lower support of a reactor core composed of two concentric rings, a bottom plate, a top plate and 15 stiffening radial plates. For calculation an annular sector representing 1/30 of this structure is modelized. The behaviour of the structure is examined for the following conditions: an instantaneous temperature rise from 4000C to 6500C, then the temperature is maintained for 400 hours and decreased from 6500 to 4000 at a rate of 0.2 degree/hour. The results obtained by elastic analysis, limit analysis and viscoplastic analysis are compared. The reference stress methods is reliable for the determination of structure dimensioning and is less expensive than the viscoplastic analysis. 35 drawings and 19 tables are given
Institute of Scientific and Technical Information of China (English)
余生兵; 黄茂松
2011-01-01
基于极限分析法的基本原理以及集成与组合的思路,推导组合块体集的内能耗散和重力做功,运用组合的思想构造斜坡地形下浅埋水平条形锚板的运动许可速度场.首先分析地表水平条件下法向受力水平条形锚板抗拔承载力,并与文献中已有解和模型试验进行对比,验证块体集上限法的优越性.然后详细研究斜坡地形条件下土体重度、不排水抗剪强度、斜坡倾角等因素对条形锚板抗拔承载力和破坏面形状的影响.分析结果表明:重力叠加法并不适用于斜坡地形情况;随着斜坡倾角的增大,锚板的破坏面向坡角方向倾斜;锚板埋深比越大,斜坡倾角的影响也越显著.块体集上限分析方法构造简单,求解快捷,能够为工程设计提供依据.%Based on the bound theorems of limit analysis, admissible velocity field of horizontal strip anchor is constructed by using a combination of several rotational block sets. An application to upper bound analysis of vertically loaded strip anchors on horizontal ground surface is given first to illustrate the utility and effectiveness of the proposed method, and include detailed comparisons with results obtained from other approaches. Then the pull-out capacities of strip anchors in undrained clay with sloping ground surface are analyzed. Pull-out capacity and failure surface characteristics under different embedment ratios, undrained strength, inclined angles of slopes and weight of soil are studied. The results show that the superposition of gravity is not applicable to the case of sloping ground surface. The variation of slope angle has a significant impact on failure surface. The block set mechanism is based on a very simple concept which is integration and combination and can be a reference for the practical design.
International Nuclear Information System (INIS)
The accuracy, precision and determination limit were evaluated for determination of Al, As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Sb, Sc, Se, V and Zn in human head hair by instrumental neutron activation analysis. The precision was examined by analyzing human hair sample, and the results of relative standard deviations obtained ranged from 3.9 to 16.2%. The results accuracy was evaluated by using reference materials GBW 09101 Human Hair and NIES 5 Human Hair. Currie criterion was used for calculation of the determination limit. (author). 8 refs., 2 tabs
Limit analysis based on a modified elastic compensation method for nozzle-to-cylinder junctions
International Nuclear Information System (INIS)
To address the computational difficulties of the elastic compensation method (ECM) for complex structures such as nozzle-to-cylinder junctions, this paper develops a modified elastic compensation method (MECM). This method improves the precision of the ECM while preserving the advantages such as simplicity and high efficiency. Limit loads are calculated for three representative examples. The calculated solutions are compared with results from the elastic-plastic analysis method and the twice-elastic slope method. It is found that the MECM can provide a good estimation of plastic limit loads for complex structures
Optical Limiting Properties of Ag-Cu Metal Alloy Nanoparticles Analysis by using MATLAB
International Nuclear Information System (INIS)
Ag-Cu alloy nanoparticles were formed by sequential ion implantation (Ag and Cu) in silica using a metal vapor vacuum arc (MEVVA) ion source. Third-order nonlinear optical properties of the nanoparticles were measured at 1064 nm excitations using the Z-scan technique. Curve fitting analysis, based on the MATLAB features for Ag-Cu alloy nanoparticle optical limiting experiments, is used. The results show that Ag-Cu alloy nanoparticles display a refractive optical limiting effect at 1064nm. (condensed matter: structure, mechanical and thermal properties)
Performance analysis of optical burst switching node with limited wavelength conversion capabilities
Institute of Scientific and Technical Information of China (English)
XU Yi; SHI Kai-yuan; FAN Ge
2009-01-01
The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching (OBS) nodes with limited wavelength conversion capability (LWCC). The relevant system architectures of limited range and limited number of wavelength converters (WCs) deployed by a share-per-fiber (SPF) mode were developed, and the novel theoretical analysis of node blocking probability was derived by combining the calculation of discouraged arrival rate in a birth-death process and two-dimensional Markov chain model of SPF. The simulation results on single node performance verify the accuracy and effectiveness of the analysis models. Under most scenarios, it is difficult to distinguish the plots generated by the analysis and simulation. As the conversion degree increases, the accuracy of the analysis model worsens slightly. However, the utmost error on burst loss probability is far less than one order of magnitude and hence, still allows for an accurate estimate. Some results are of actual significance to the construction of next-generation commercial OBS backbones.
International Nuclear Information System (INIS)
In the framework of safety analysis for the Belgian nuclear power plants and for the reload compatibility studies, Tractebel Energy Engineering (TEE) has developed, to define a 95/95 DNBR criterion, a statistical thermal design method based on the analytical full statistical approach: the Statistical Thermal Design Procedure (STDP). In that methodology, each DNBR value in the core assemblies is calculated with an adapted CHF (Critical Heat Flux) correlation implemented in the sub-channel code Cobra for core thermal hydraulic analysis. The uncertainties of the correlation are represented by the statistical parameters calculated from an experimental database. The main objective of a sub-channel analysis is to prove that in all class 1 and class 2 situations, the minimum DNBR (Departure from Nucleate Boiling Ratio) remains higher than the Safety Analysis Limit (SAL). The SAL value is calculated from the Statistical Design Limit (SDL) value adjusted with some penalties and deterministic factors. The search of a realistic value for the SDL is the objective of the statistical thermal design methods. In this report, we apply a full statistical approach to define the DNBR criterion or SDL (Statistical Design Limit) with the strict observance of the design criteria defined in the Standard Review Plan. The same statistical approach is used to define the expected number of rods experiencing DNB. (author)
Bounds in the generalized Weber problem under locational uncertainty
DEFF Research Database (Denmark)
Juel, Henrik
1981-01-01
An existing analysis of the bounds on the Weber problem solution under uncertainty is incorrect. For the generalized problem with arbitrary measures of distance, we give easily computable ranges on the bounds and state the conditions under which the exact values of the bounds can be found with...
BOUNDED MINIMUM INHERENT AVAILABILITY REQUIREMENTS FOR THE SYSTEM DESCRIPTION DOCUMENTS
International Nuclear Information System (INIS)
The purpose of this analysis is to establish bounded minimum inherent availability requirements for the Mined Geologic Disposal System (MGDS) System Description Documents (SDDs). The purpose of the bounded minimum inherent availability is to provide a lower bound on availability which will allow design to meet throughput requirements while not affecting the ability of the items to perform their intended safety function
Lower bounds on fluctuations for internal DLA
Asselah, Amine
2011-01-01
We consider internal diffusion limited aggregation in dimension larger than or equal to two. This is a random cluster growth model, where random walks start at the origin of the d-dimensional lattice, one at a time, and stop moving when reaching a site that is not occupied by previous walks. When n random walks are sent from the origin, we establish a lower bound for the inner and outer errors fluctuations of order square root of the logarithm of n. When dimension is larger or equal to three, this lower bound matches the upper bound recently obtained in independent works of \\cite{AG2} and \\cite{JLS2}. Also, we produce as a corollary of our proof of \\cite{AG2}, an upper bound for the fluctuation of the inner error in a specified direction.
The Fitness Level Method with Tail Bounds
Witt, Carsten
2013-01-01
The fitness-level method, also called the method of f-based partitions, is an intuitive and widely used technique for the running time analysis of randomized search heuristics. It was originally defined to prove upper and lower bounds on the expected running time. Recently, upper tail bounds were added to the technique; however, these tail bounds only apply to running times that are at least twice as large as the expectation. We remove this restriction and supplement the fitness-level method ...
International Nuclear Information System (INIS)
We perform a Monte Carlo Markov chains (MCMC) analysis of the available cosmic microwave background (CMB) and large scale structure (LSS) data (including the three years WMAP data) with single field slow-roll new inflation and chaotic inflation models. We do this within our approach to inflation as an effective field theory in the Ginsburg-Landau spirit with fourth degree trinomial potentials in the inflaton field φ. We derive explicit formulae and study in detail the spectral index ns of the adiabatic fluctuations, the ratio r of tensor to scalar fluctuations, and the running index dns/dlnk. We use these analytic formulas as hard constraints on ns and r in the MCMC analysis. Our analysis differs in this crucial aspect from previous MCMC studies in the literature involving the WMAP3 data. Our results are as follows: (i) The data strongly indicate the breaking (whether spontaneous or explicit) of the φ→-φ symmetry of the inflaton potentials both for new and for chaotic inflation. (ii) Trinomial new inflation naturally satisfies this requirement and provides an excellent fit to the data. (iii) Trinomial chaotic inflation produces the best fit in a very narrow corner of the parameter space. (iv) The chaotic symmetric trinomial potential is almost certainly ruled out (at 95% C.L.). In trinomial chaotic inflation the MCMC runs go towards a potential in the boundary of the parameter space and which resembles a spontaneously symmetry broken potential of new inflation. (v) The above results and further physical analysis here lead us to conclude that new inflation gives the best description of the data. (vi) We find a lower bound for r within trinomial new inflation potentials: r>0.016(95%CL) and r>0.049(68%CL). (vii) The preferred new inflation trinomial potential is a double well, even function of the field with a moderate quartic coupling yielding as most probable values: ns≅0.958, r≅0.055. This value for r is within reach of forthcoming CMB observations
Caorso limit cycle oscillation analysis with three-dimensional transient code TOSDYN-2
International Nuclear Information System (INIS)
The Caorso limit cycle data observed during the stability tests were analyzed by the three-dimensional transient code TOSDYN-2. The Caorso limit cycle oscillation was spatially out of phase, and both the amplitude and the extent of the large amplitude region were large. For this reason, it is very valuable for the qualification of the TOSDYN-2 code. TOSDYN-2 employs a three-dimensional neutronics model and a multichannel-type thermal-hydraulic model. The channel-type grouping is important for qualification analysis. It was determined by considering the test results and the more detailed three-dimensional steady-state code results. The analytical results imply that many unstable channels or unstable regions might exist separately in the core. To account for this, TOSDYN-2 could accurately simulate both the amplitude of the limit cycle oscillation and the spatial power change profile. Thus, TOSDYN-2 applicability to the spatial power change phenomenon has been well verified
Energy Technology Data Exchange (ETDEWEB)
N' Guessan, L.A.; Elifantz, H.; Nevin, K.P.; Mouser, P.J.; Methe, B.; Woodard, T. L.; Manley, K.; Williams, K. H.; Wilkins, M. J.; Larsen, J.T.; Long, P. E.; Lovley, D. R.
2009-09-01
Nutrient limitation is an environmental stress that may reduce the effectiveness of bioremediation strategies, especially when the contaminants are organic compounds or when organic compounds are added to promote microbial activities such as metal reduction. Genes indicative of phosphate-limitation were identified via microarray analysis of chemostat cultures of Geobacter sulfureducens. This analysis revealed that genes in the pst-pho operon, which is associated with a high affinity phosphate uptake system in other microorganisms, had significantly higher transcript abundance under phosphate-limiting conditions, with the genes pstB and phoU the most up-regulated. Quantitative PCR analysis of pstB and phoU transcript levels in G. sulfurreducens grown in chemostats demonstrated that the expression of these genes increased when phosphate was removed from the culture medium. Transcripts of pstB and phoU within the subsurface Geobacter species predominating during an in situ uranium bioremediation field experiment were more abundant than in chemostat cultures of G. sulfurreducens that were not limited for phosphate. Addition of phosphate to incubations of subsurface sediments did not stimulate dissimilatory metal reduction. The added phosphate was rapidly adsorbed onto the sediments. The results demonstrate that Geobacter species can effectively reduce U(VI) even when experiencing suboptimal phosphate concentrations and that increasing phosphate availability with phosphate additions is difficult to achieve due to the high reactivity of this compound. This transcript-based approach developed for diagnosing phosphate limitation should be applicable to assessing the potential need for additional phosphate in other bioremediation processes.
Three-dimensional analysis of contact conditions in the TFTR limiter tiles
International Nuclear Information System (INIS)
The graphite tiles for the limiters of the TFTR are attached to water-cooled Inconel backup plates using a T-shaped bar that is situated in a slot in the graphite. During the pulsed heating of the limiter surface, the tile tends to bow, and interaction of the tile with the T-bar causes tensile stresses in the root of the slot. These are the dominant stresses for the design of the limiter. The stresses in the T-bar slot depend on the contact conditions between the tile and the backup plate and between the T-bar and the slot. A three-dimensional analysis, reported herein, was undertaken to determine the contact conditions in some detail. The analysis was performed using finite element programs that were developed at GA Technologies for the nonlinear thermal and stress analysis of threedimensional solids. These programs, HEAT3 and THREED, have two attributes that were useful in this application: numerical efficiency and a general-purpose material interface. The contact conditions were modeled by means of a nonlinear gap material having discontinuous, anisotropic stress-strain behavior. This technique proved to be effective, stable, and rapidly converging. The results of the analysis showed that three-dimensional effects are important. The contact conditions cannot be modeled adequately in only two dimensions because variations along the length of the bar and torque in the bar are significant. The largest tensile stress in the graphite predicted by the 3-D analysis was 42% larger than that predicted by a 2-D analysis
Application of the LIMIT code to the analysis of containment hydrogen transport
International Nuclear Information System (INIS)
The principal developmental focus of the LIMIT code is the ability to model hydrogen transport accurately in reactor containments. The program is capable of treating rapid two-phase dominated blowdown transients, slower mixing events in which diffusional transport is important, and lumped or nodal multicompartment analysis. The code's features include versatile multidimensional geometry options and models of ancillary equipment including solid heat sinks and mass and energy sources. The program is applied to a number of pertinent problems including continuum analysis of a hydrogen/water blowdown, simulation of experimental tests performed at the Battelle-Frankfurt Institute and the Hanford Engineering Development Laboratory, and lumped parameter studies of connected room problems. The code is shown to be capable of accurately treating a wide range of problems with reasonable computational efficiency. The need for even better efficiency, additional equipment submodels, and further validation are the code's principal limitations
Decaying dark matter: a stacking analysis of galaxy clusters to improve on current limits
Combet, C.; Maurin, D.; Nezri, E.; Pointecouteau, E.; Hinton, J. A.; R White
2012-01-01
We show that a stacking approach to galaxy clusters can improve current limits on decaying dark matter by a factor $\\gtrsim 5-100$, with respect to a single source analysis, for all-sky instruments such as Fermi-LAT. Based on the largest sample of X-ray-selected galaxy clusters available to date (the MCXC meta-catalogue), we provide all the astrophysical information, in particular the astrophysical term for decaying dark matter, required to perform an analysis with current instruments.
A Ballistic Limit Analysis Program for Shielding Against Micrometeoroids and Orbital Debris
Ryan, Shannon; Christiansen, Erie
2010-01-01
A software program has been developed that enables the user to quickly and simply perform ballistic limit calculations for common spacecraft structures that are subject to hypervelocity impact of micrometeoroid and orbital debris (MMOD) projectiles. This analysis program consists of two core modules: design, and; performance. The design module enables a user to calculate preliminary dimensions of a shield configuration (e.g., thicknesses/areal densities, spacing, etc.) for a ?design? particle (diameter, density, impact velocity, incidence). The performance module enables a more detailed shielding analysis, providing the performance of a user-defined shielding configuration over the range of relevant in-orbit impact conditions.
Limitations of clonality analysis of B cell proliferations using CDR3 polymerase chain reaction
Hoeve, M A; Krol, A D G; Philippo, K; Derksen, P W B; Veenendaal, R. A.; Schuuring, E; Kluin, Ph M; Krieken, J.H.J.M. van
2000-01-01
Background/Aims—Detection of clonal immunoglobulin heavy chain (IgH) rearrangements by the polymerase chain reaction (PCR) is an attractive alternative to Southern blotting in lymphoma diagnostics. However, the advantages and limitations of PCR in clonality analysis are still not fully appreciated. In this study, clonality was analysed by means of PCR, focusing in particular on the sample size requirements when studying extremely small samples of polyclonal and monoclonal lesions.
Modeling Diffusion-Limited Crystal Growth from Vapor using a Commercial Finite-Element Analysis Code
Libbrecht, Kenneth G.
2006-01-01
This application note describes how to model diffusion-limited crystal growth from vapor using QuickField - a commercial finite-element analysis code. The crystal growth problem is cast into the format of a steady-state heat diffusion problem, which is one type of problem QuickField is designed to solve, and we derive the relevant conversion factors and correspondences between variables. We also describe three types of boundary conditions in the crystal growth problem and their corresponding ...
Paulo B. Lourenço
2007-01-01
Continuum-based numerical methods have played a leading role in the numerical solution of problems in soil and rock mechanics. However, for stratified soils and fractured rocks, a continuum assumption often leads to difficult parameters to define and over-simplified geometry to be realistic. In such cases, approaches that consider the micro-structure of the material can be adopted. In this paper, two of such approaches are detailed, namely limit analysis incorporating fractures...
LIMITS OF SWOT ANALYSIS AND THEIR IMPACT ON DECISIONS IN EARLY WARNING SYSTEMS
Florin POPESCU; Cezar SCARLAT
2015-01-01
SWOT (strengths, weaknesses, opportunities, threats) analysis is useful in the decision-making process – crucial to any organization manager and/or strategist. This study aims to add value to the existing literature on SWOT, indicating its use and limitations, showing the need to link SWOT to other strategic tools and methodologies. As the current environment is turbulent and unpredictable, and economic cycles no longer comply with traditional rules, the precaution has become extremely i...
The limits of protest event data and repertoires for the analysis of contemporary feminism
Bagguley, P
2010-01-01
Protest event data (PEA) and the related concept of repertoire of contention is widely used in the study of social movements. I argue that conventional forms of protest event analysis may have significant limitations when applied to feminist protest. Unobtrusive or individualised forms of resistance and protest associated with feminism are difficult to measure through typical protest event data. Moreover, the concept of repertoires of contention retains within it a number of unwarranted gende...
Asynchronous Bounded Expected Delay Networks
Bakhshi, Rena; Endrullis, Jörg; Fokkink, Wan; Pang, Jun
2010-01-01
The commonly used asynchronous bounded delay (ABD) network models assume a fixed bound on message delay. We propose a probabilistic network model, called asynchronous bounded expected delay (ABE) model. Instead of a strict bound, the ABE model requires only a bound on the expected message delay. While the conditions of ABD networks restrict the set of possible executions, in ABE networks all asynchronous executions are possible, but executions with extremely long delays are less probable. In ...
On Entropy Bounds and Holography
Halyo, Edi
2009-01-01
We show that the holographic entropy bound for gravitational systems and the Bekenstein entropy bound for nongravitational systems are holographically related. Using the AdS/CFT correspondence, we find that the Bekenstein bound on the boundary is obtained from the holographic bound in the bulk by minimizing the boundary energy with respect the AdS radius or the cosmological constant. This relation may also ameliorate some problems associated with the Bekenstein bound.
Optical Limiting Properties of Ag-Cu Metal Alloy Nanoparticles Analysis by using MATLAB
Institute of Scientific and Technical Information of China (English)
WANG Yu-Hua; LI Hui-Qing; LU Jian-Duo; WANG Ru-Wu
2011-01-01
Ag-Cu alloy nanoparticles were formed by sequential ion implantation (Ag and Cu) in silica using a metal vapor vacuum arc (MEVVA) ion source.Third-order nonlinear optical properties of the nanoparticles were measured at 1064nm excitations using the Z-scan technique.Curve fitting analysis,based on the MATLAB features for Ag-Cu alloy nanoparticle optical limiting experiments,is used.The results show that Ag-Cu alloy nanoparticles display a refractive optical limiting effect at 1064 nm.Recently,increasing attention has been focused on the third-order nonlinear susceptibility and the photorefractive effect of noble-metal clusters embedded in dielectric matrices.[1-3] Third-order nonlinearities of metal/dielectric composite materials are influenced not only by the type and size of the embedded metal clusters,but also by the dielectric constant,thermal conductivity and heat capacity of the dielectric matrices.[4-6] Amongst the nanoparticles studied earlier,high nonlinear absorption and nonlinear refraction coefficients were found in copper and copper containing nanomaterials.[7,8] For silver,the nonlinear refractive index γ changes from positive to negative upon the growth of clusters.[9] Potential applications of optical limiters in the protection of sensors from intense laser pulses have motivated great efforts to design new nonlinear optical systems.[10]%Ag-Cu alloy nanoparticles were formed by sequential ion implantation (Ag and Cu) in silica using a metal vapor vacuum arc (MEVVA) ion source. Third-order nonlinear optical properties of the nanoparticles were measured at 1064 nm excitations using the Z-scan technique. Curve fitting analysis, based on the MATLAB features for Ag-Cu alloy nanoparticle optical limiting experiments, is used. The results show that Ag-Cu alloy nanoparticles display a refractive optical limiting effect at 1064 nm.
Guenter Goerigk; Sebastian Lages; Klaus Huber
2016-01-01
Anomalous small angle scattering measurements have been applied to diluted solutions of anionic polyacrylates decorated by specifically-interacting Pb2+ cations, revealing partial collapse of the polyacrylate into pearl-like subdomains with a size on the order of a few nanometers. From the pure-resonant scattering contribution of the Pb2+ cations, and from subsequent analysis of the resonant-invariant, the amount of Pb2+ cations condensed onto the polyanions with respect to the total amount o...
New Bound on gamma from B^+- -> pi K Decays
Neubert, M.; Rosner, J. L.
1998-01-01
A bound on the angle gamma of the unitarity triangle is derived using experimental information on the CP-averaged branching ratios for the rare decays B^+- -> pi^+- K^0 and B^+- -> pi^0 K^+-. The theoretical description is cleaner than the Fleischer-Mannel analysis of the decays B^+- -> pi^+- K^0 and B^0 -> pi^-+ K^+- in that the two decay rates differ only in a single isospin amplitude, which has a simple structure in the SU(3) limit. As a consequence, electroweak penguin contributions and s...
DEFF Research Database (Denmark)
Damgård, Ivan Bjerre; Faust, Sebastian; Mukherjee, Pratyay; Venturi, Daniele
Related key attacks (RKAs) are powerful cryptanalytic attacks where an adversary can change the secret key and observe the effect of such changes at the output. The state of the art in RKA security protects against an a-priori unbounded number of certain algebraic induced key relations, e...... bounded tamper and leakage resilient CCA secure public key cryptosystem based on the DDH assumption. We first define a weaker CPA-like security notion that we can instantiate based on DDH, and then we give a general compiler that yields CCA-security with tamper and leakage resilience. This requires a...... public tamper-proof common reference string. Finally, we explain how to boost bounded tampering and leakage resilience (as in 1. and 2. above) to continuous tampering and leakage resilience, in the so-called floppy model where each user has a personal hardware token (containing leak- and tamper...
Garcilazo, H
2016-01-01
We have used realistic local interactions based on the recent update of the strangeness $-2$ Nijmegen ESC08c potential to calculate the bound state problem of the $\\Xi NN$ system in the $(I)J^P=(\\frac{1}{2})\\frac{3}{2}^+$ state. We found that this system presents a deeply bound state lying $13.5$ MeV below the $\\Xi d$ threshold. Since in lowest order, pure S$-$wave configuration, this system can not decay into the open $\\Lambda\\Lambda N$ channel, its decay width is expected to be very small. We have also recalculated the $(I)J^P=(\\frac{3}{2})\\frac{1}{2}^+$ state and we have compared with results of quark-model based potentials.
Uyanık, Osman; Ekinci, Buket; Uyanık, N. Ayten
2013-08-01
This study analyzes liquefaction in the Kumluca/Antalya residential area and surroundings, using seismic velocities of soil deposits and the predominant period of the earthquake wave. The liquefaction analysis calculates shear-stress ratio, shear-resistance ratio and safety factor. Shear wave velocity used in liquefaction analysis was determined through surface waves. Moreover, the dynamic parameters of the ground were calculated through seismic velocities. Distributions of groundwater, shear wave velocity, adjusted shear wave velocity, predominant period of vibration, soil amplification and ground acceleration of the research area were mapped. In addition, the liquefied and non-liquefied areas as a result of liquefaction analysis in Kumluca were determined and presented as maps. Examining these maps, among all these maps, the limits of the lagoon sandbar and the old lake area were determined using only the liquefaction map.
Towards Secure Distance Bounding
Boureanu, Ioana; Mitrokotsa, Aikaterini; Vaudenay, Serge
2013-01-01
Relay attacks (and, more generally, man-in-the-middle attacks) are a serious threat against many access control and payment schemes. In this work, we present distance-bounding protocols, how these can deter relay attacks, and the security models formalizing these protocols. We show several pitfalls making existing protocols insecure (or at least, vulnerable, in some cases). Then, we introduce the SKI protocol which enjoys resistance to all popular attack-models and features provable security....
Kahneman, Daniel
2002-01-01
The work cited by the Nobel committee was done jointly with the late Amos Tversky (1937-1996) during a long and unusually close collaboration. Together, we explored the psychology of intuitive beliefs and choices and examined their bounded rationality. This essay presents a current perspective on the three major topics of our joint work: heuristics of judgment, risky choice, and framing effects. In all three domains we studied intuitions - thoughts and preferences that come to mind quickly an...
KETENCI, Uktu Gorkem; Bremond, Roland; Auberlet, Jean Michel; GRISLIN, Emmanuelle
2010-01-01
There are two kinds of perception : active and passive. This paper is an attempt to take advantage of active perception to improve the agent's perception of relevant information. Through the data filtering capacity, active perception is a useful tool for modeling human-like bounded perception. Using such filters, either the agent or the environment take an active role. We determine several unsolved issues in active perception and do several proposals to implement our concept on the active per...
Banderier, Cyril; Nicodeme, Pierre
2010-01-01
This article tackles the enumeration and asymptotics of directed lattice paths (that are isomorphic to unidimensional paths) of bounded height (walks below one wall, or between two walls, for \\emphany finite set of jumps). Thus, for any lattice paths, we give the generating functions of bridges (``discrete'' Brownian bridges) and reflected bridges (``discrete'' reflected Brownian bridges) of a given height. It is a new success of the ``kernel method'' that the generating functions of such wal...
Radially inhomogeneous bounded plasmas
Zakeri-Khatir, H.; Aghamir, F. M.
2016-07-01
On the basis of kinetic theory along with self-consistent field equations, the expressions for dielectric tensor of radially inhomogeneous magnetized plasma columns are obtained. The study of dielectric tensor characteristics allows the accurate analysis of the inhomogeneous properties, beyond limitations that exist in the conventional method. Through the Bessel–Fourier transformation, the localized form of material equations in a radially inhomogeneous medium are obtained. In order to verify the integrity of the model and reveal the effect of inhomogeneity, a special case of a cylindrical plasma waveguide completely filled with inhomogeneous magnetized cold plasma was considered. The dispersion relation curves for four families of electromagnetic (EH and HE) and electrostatic (SC and C) modes are obtained and compared with the findings of the conventional model. The numerical analysis indicates that the inhomogeneity effect leads to coupling of electromagnetic and electrostatic modes each having different radial eigen numbers. The study also reveals that the electrostatic modes are more sensitive to inhomogeneous effects than the electromagnetic modes.
Adaptive selective ES-FEM limit analysis of cracked plane-strain structures
Institute of Scientific and Technical Information of China (English)
H. NGUYEN-XUAN[1; T. RABCZUK[2
2015-01-01
This paper presents a simple and efficient approach for predicting the plastic limit loads in cracked plane- strain structures. We use two levels of mesh repartitioning for the finite element limit analysis. The master level handles an adaptive primal-mesh process through a dissipation-based indicator. The slave level performs the subdivision of each triangle into three sub-triangles and constitutes a dual mesh from a pair of two adjacent sub-triangles shared by common edges of the primal mesh. Applying a strain smoothing projection to the strain rates on the dual mesh, the incompressibility constraint and the flow rule constraint are imposed over the edge-based smoothing domains and everywhere in the problem domain. The limit analysis problem is recast into the compact form of a second-order cone programming （SOCP） for the purpose of exploiting interior-point solvers. The present method retains a low number of optimization variables. It offers a convenient way for designing and solving the large-scale optimization problems effectively. Several benchmark examples are given to show the simplicity and effectiveness of the present method.
Consideration of tip speed limitations in preliminary analysis of minimum COE wind turbines
Cuerva-Tejero, A.; Yeow, T. S.; Lopez-Garcia, O.; Gallego-Castillo, C.
2014-12-01
A relation between Cost Of Energy, COE, maximum allowed tip speed, and rated wind speed, is obtained for wind turbines with a given goal rated power. The wind regime is characterised by the corresponding parameters of the probability density function of wind speed. The non-dimensional characteristics of the rotor: number of blades, the blade radial distributions of local solidity, twist, angle, and airfoil type, play the role of parameters in the mentioned relation. The COE is estimated using a cost model commonly used by the designers. This cost model requires basic design data such as the rotor radius and the ratio between the hub height and the rotor radius. Certain design options, DO, related to the technology of the power plant, tower and blades are also required as inputs. The function obtained for the COE can be explored to find those values of rotor radius that give rise to minimum cost of energy for a given wind regime as the tip speed limitation changes. The analysis reveals that iso-COE lines evolve parallel to iso-radius lines for large values of limit tip speed but that this is not the case for small values of the tip speed limits. It is concluded that., as the tip speed limit decreases, the optimum decision for keeping minimum COE values can be: a) reducing the rotor radius for places with high weibull scale parameter or b) increasing the rotor radius for places with low weibull scale parameter.
Consideration of tip speed limitations in preliminary analysis of minimum COE wind turbines
International Nuclear Information System (INIS)
A relation between Cost Of Energy, COE, maximum allowed tip speed, and rated wind speed, is obtained for wind turbines with a given goal rated power. The wind regime is characterised by the corresponding parameters of the probability density function of wind speed. The non-dimensional characteristics of the rotor: number of blades, the blade radial distributions of local solidity, twist, angle, and airfoil type, play the role of parameters in the mentioned relation. The COE is estimated using a cost model commonly used by the designers. This cost model requires basic design data such as the rotor radius and the ratio between the hub height and the rotor radius. Certain design options, DO, related to the technology of the power plant, tower and blades are also required as inputs. The function obtained for the COE can be explored to find those values of rotor radius that give rise to minimum cost of energy for a given wind regime as the tip speed limitation changes. The analysis reveals that iso-COE lines evolve parallel to iso-radius lines for large values of limit tip speed but that this is not the case for small values of the tip speed limits. It is concluded that., as the tip speed limit decreases, the optimum decision for keeping minimum COE values can be: a) reducing the rotor radius for places with high weibull scale parameter or b) increasing the rotor radius for places with low weibull scale parameter
Bounds to the conductivity of some two-component composites
Helsing, Johan
1993-02-01
Calculation of third-order bounds to the conductivity of isotropic two-component composites is discussed. Coincidence of the Beran bounds and bounds derived using trial fields based on the solution of a single-body electrostatic boundary-value problem is demonstrated for a random distribution of impenetrable ellipsoids. This extends a proof of Beasley and Torquato [J. Appl. Phys. 60, 3576 (1986)]. A structural parameter related to third-order bounds is calculated for a face-centered cubic array of cubes in a matrix. For an array of rectangular blocks an upper bound in one direction is derived. This bound, and its two-dimensional analogs, become very sharp in the limit of strong inhomogeneity. Improved third- and fourth-order bounds for the three-dimensional checkerboard are presented.
Analysis of sodium pool fire in SFEF for assessing the limiting pool fire
International Nuclear Information System (INIS)
Accidental sodium leaks and resultant sodium fires in Liquid Metal Fast Breeder Reactor (LMFBR) systems can create a threat to the safe operation of the plant. To avoid this defence-in depth approach is implemented from the design stage of reactor itself. Rapid detection of sodium leak and fast dumping of the sodium into the storage tank of a defective circuit, leak collection trays, adequate lining of load bearing structural concrete and extinguishment of the sodium fire are the important defensive measures in the design, construction and operation of a LMFBR for protection against sodium leaks and their resultant fires. Evaluation of sodium leak events and their consequences by conducting large scale engineering experiments is very essential for effective implementation of the above protection measures for sodium fire safety. For this purpose a Sodium Fire Experimental Facility (SFEF) is constructed at SED, IGCAR. SFEF is having an experimental hall of size 9 m x 6 m x 10 m with 540 m3 volume and its design pressure is 50 kPa. It is a concrete structure and provided with SS 304 liner, which is fixed to the inside surfaces of walls, ceiling and floor. A leak tight door of size (1.8 m x 2.0 m) is provided to the experimental hall and the facility is provided with a sodium equipment hall and a control room. Experimental evaluation of sodium pool fire consequences is an important activity in the LMFBR sodium fire safety related studies. An experimental program has been planned for different types of sodium fire studies in SFEF. A prior to that numerical analysis have been carried out for enclosed sodium pool fires using SOFIRE-II sodium pool fire code for SFEF experimental hall configuration to evaluate the limiting pool fire. This paper brings out results of the analysis carried out for this purpose. Limiting pool fire of SFEF depends on the exposed surface area of the pool, amount of sodium in the pool, oxygen concentration and initial sodium temperature. Limiting
A Novel Parametric Bound for Information Retrieval from Black Hole Radiation
Roy, Avik; Alvi, Mishkat Al; Majumdar, Mahbub; Matin, Md Abdul
2013-01-01
Hawking's argument about non-unitary evolution of black holes is often questioned on the ground that it doesn't acknowledge the quantum correlations in radiation process. However, recently it has been shown that adding `small' correction to leading order Hawking analysis, accounting for the correlations, doesn't help to restore unitarity. This paper generalizes the bound on entanglement entropy by relaxing the `smallness' condition and configures the parameters for possible recovery of information from an evaporating black hole. The new bound effectively puts an upper limit on increase in entanglement entropy. It also facilitates to relate the change in entanglement entropy to the amount of correction to Hawking state.
Directory of Open Access Journals (Sweden)
Igor Albertovich Brigadnov
2012-08-01
Full Text Available The problem of minimization of ill-conditioned functions is considered. This problem arises as a result of finite-element approximation of the limit analysis problem for dielectrics in powerful electric fields. The objective function is nonsmooth therefore a smooth regularization of finite-dimensional problem is used. As a result distinct ravine of objective function is acquired. Convergence of the gradient and the heave-ball methods in relation to its internal and optimization parameters are studied inside the numerical computing environment and fourth-generation programming language Matlab.
Limitations and pitfalls of climate change impact analysis on urban rainfall extremes
DEFF Research Database (Denmark)
Willems, P.; Olsson, J.; Arnbjerg-Nielsen, Karsten;
Under the umbrella of the IWA/IAHR Joint Committee on Urban Drainage, the International Working Group on Urban Rainfall (IGUR) has reviewed existing methodologies for the analysis of long-term historical and future trends in urban rainfall extremes and their effects on urban drainage systems, due...... to anthropogenic climate change. Current practices have several limitations and pitfalls, which are important to be considered by trend or climate change impact modellers and users of trend/impact results. Climate change may well be the driver that ensures that changes in urban drainage paradigms are...
Simulation and analytic analysis of radiation driven islands at the density limit
Brennan, D. P.; Liu, C.; Gates, D. A.; Delgado-Aparicio, L.; White, R.
2014-10-01
The effect of radiative cooling on the onset and evolution of magnetic islands is investigated with nonlinear resistive MHD simulations and reduced theoretical analysis. The configuration is a cylindrical tokamak with a m/n = 2/1 island and includes three dimensional resistivity and anisotropic heat conduction in the simulations. The radiative cooling is implemented as a temperature perturbation inside the island, which modifies the island structure and drives the island more unstable. Analytic reduction of the saturated island size and structure supports the simulation results. The results offer intuitive understanding of experimental observations of radiation driven magnetic islands, which may explain density limit disruptions.
Predicting propagation limits of laser-supported detonation by Hugoniot analysis
Shimamura, Kohei; Ofosu, Joseph A.; Komurasaki, Kimiya; Koizumi, Hiroyuki
2015-01-01
Termination conditions of a laser-supported detonation (LSD) wave were investigated using control volume analysis with a Shimada-Hugoniot curve and a Rayleigh line. Because the geometric configurations strongly affect the termination condition, a rectangular tube was used to create the quasi-one-dimensional configuration. The LSD wave propagation velocity and the pressure behind LSD were measured. Results reveal that the detonation states during detonation and at the propagation limit are overdriven detonation and Chapman-Jouguet detonation, respectively. The termination condition is the minimum velocity criterion for the possible detonation solution. Results were verified using pressure measurements of the stagnation pressure behind the LSD wave.
Analysis of FEL-based CeC amplification at high gain limit
International Nuclear Information System (INIS)
An analysis of Coherent electron Cooling (CeC) amplifier based on 1D Free Electron Laser (FEL) theory was previously performed with exact solution of the dispersion relation, assuming electrons having Lorentzian energy distribution. At high gain limit, the asymptotic behavior of the FEL amplifier can be better understood by Taylor expanding the exact solution of the dispersion relation with respect to the detuning parameter. In this work, we make quadratic expansion of the dispersion relation for Lorentzian energy distribution and investigate how longitudinal space charge and electrons@@@ energy spread affect the FEL amplification process.
Analysis of density limit with radial profile of electric field in helical plasmas
International Nuclear Information System (INIS)
Full text: The study of the plasma confinement physics is the urgent task of nuclear fusion research. The phenomena of the density limit control how the plasma performance is achievable. In tokamaks, the properties of the confinement and the density limit are dictated. In helical plasmas, attention has been paid to the phenomena of the density limit. The helical plasmas have an additional freedom in magnetic geometry, which is utilized to investigate the transport mechanisms. The density limit phenomena in toroidal helical plasmas were examined with the analytic point model. Since the radial electric field determined by the ambipolar condition in a non-axisymmetric system is known to affect the confinement property significantly, theoretical analysis of the density limit including the radiation loss in helical plasmas is necessary with the effect of the ambipolar radial electric field in a set of transport equations. To examine the density limit for the thermal stability in helical plasmas, we add the term of the radiation loss rate of the energy to the temporal equation of the electron temperature in a set of one-dimensional transport equations. The radiative loss of the line emission from the impurity ions has a temperature dependence that the loss increases if the temperature gets lower. The combined mechanism of the transport and the radiation loss of the energy is discussed. The dependence of the electron temperature profile on the electron heating is studied when the radiative cooling rate is included in a set of the transport equations to examine the density limit in helical plasmas. The parameter dependence of the critical density is derived, when the effect of the radial electric field is included. The sharp decrease of the electron temperature is shown near the edge. This is because the radiative loss rate rapidly increases at the low temperature. The phenomenon like the transition near the edge in the Er profile is obtained. The value of the turbulent
Bounded Rationality and Tacit Knowledge in the Organizational Capabilities Approach
Foss, Nikolaj J.
2004-01-01
The famous three chapters in Nelson and Winter (1982) that focus on firm routines and capabilities are often taken to be solidly founded on an assumption of bounded rationality. I argue that, in actuality, bounded rationality plays a rather limited role in Nelson and Winter (1982), that the very different assumption of tacit knowledge is much more central, and that the links between bounded rationality and routines/capabilities are not clear. I then argue that the absence in Nelson and Winter...
Analysis of limited-diffractive and limited-dispersive X-waves generated by finite radial waveguides
Fuscaldo, Walter; Pavone, Santi C.; Valerio, Guido; Galli, Alessandro; Albani, Matteo; Ettorre, Mauro
2016-05-01
In this work, we analyze the spatial and temporal features of electromagnetic X-waves propagating in free space and generated by planar radiating apertures. The performance of ideal X-waves is discussed and compared to practical cases where the important effects related to the finiteness of the radiating aperture and the wavenumber dispersion are taken into account. In particular, a practical device consisting of a radial waveguide loaded with radiating slots aligned along a spiral path is considered for the practical case in the millimeter-wave range. A common mathematical framework is defined for a precise comparison of the spatiotemporal properties and focusing capabilities of the generated X-wave. It is clearly shown that the fractional bandwidth of the radiating aperture has a key role in the longitudinal confinement of an X-wave in both ideal and practical cases. In addition, the finiteness of the radiating aperture as well as the wavenumber dispersion clearly affect both the transverse and the longitudinal profiles of the generated radiation as it travels beyond the depth-of-field of the generated X-wave. Nevertheless, the spatiotemporal properties of the X-wave are preserved even in this "dispersive-finite" case within a defined region and duration related to the nondiffractive range and fractional bandwidth of the spectral components of the generated X-wave. The proposed analysis may open new perspectives for the efficient generation of X-waves over finite radiating apertures at millimeter waves where the dispersive behavior of realistic devices is no longer negligible.
Proof of a quantum Bousso bound
Bousso, Raphael; Casini, Horacio; Fisher, Zachary; Maldacena, Juan
2014-08-01
We prove the generalized covariant entropy bound, ΔS≤(A-A')/4Gℏ, for light-sheets with initial area A and final area A'. The entropy ΔS is defined as a difference of von Neumann entropies of an arbitrary state and the vacuum, with both states restricted to the light-sheet under consideration. The proof applies to free fields, in the limit where gravitational backreaction is small. We do not assume the null energy condition. In regions where it is violated, we find that the bound is protected by the defining property of light-sheets: that their null generators are nowhere expanding.
Proof of a Quantum Bousso Bound
Bousso, Raphael; Fisher, Zachary; Maldacena, Juan
2014-01-01
We prove the generalized Covariant Entropy Bound, $\\Delta S\\leq (A-A')/4G\\hbar$, for light-sheets with initial area $A$ and final area $A'$. The entropy $\\Delta S$ is defined as a difference of von Neumann entropies of an arbitrary state and the vacuum, with both states restricted to the light-sheet under consideration. The proof applies to free fields, in the limit where gravitational backreaction is small. We do not assume the null energy condition. In regions where it is violated, we find that the bound is protected by the defining property of light-sheets: that their null generators are nowhere expanding.
Naturalness bounds on gauge mediated soft terms
Ciafaloni, P; Ciafaloni, Paolo; Strumia, Alessandro
1996-01-01
After a general discussion about the quantitative meaning of the naturalness upper bounds on the masses of supersymmetric particles, we compute these bounds in models with gauge-mediated soft terms. We find interesting upper limits on the right-handed slepton masses that, unless the messenger fields are very light, disfavor minimal models with large messenger content. Deep unphysical minima, that however turn out to be non dangerous, are usually present in such models. The mu-problem can be solved by adding a light singlet only at the price of a large amount of fine tuning that gives also rise to heavy sparticles and large tan\\beta.
Maldacena, Juan; Stanford, Douglas
2015-01-01
We conjecture a sharp bound on the rate of growth of chaos in thermal quantum systems with a large number of degrees of freedom. Chaos can be diagnosed using an out-of-time-order correlation function closely related to the commutator of operators separated in time. We conjecture that the influence of chaos on this correlator can develop no faster than exponentially, with Lyapunov exponent $\\lambda_L \\le 2 \\pi k_B T/\\hbar$. We give a precise mathematical argument, based on plausible physical assumptions, establishing this conjecture.
DEFF Research Database (Denmark)
Faupin, Jeremy; Møller, Jacob Schach; Skibsted, Erik
2011-01-01
We study regularity of bound states pertaining to embedded eigenvalues of a self-adjoint operator H, with respect to an auxiliary operator A that is conjugate to H in the sense of Mourre. We work within the framework of singular Mourre theory which enables us to deal with confined massless Pauli......–Fierz models, our primary example, and many-body AC-Stark Hamiltonians. In the simpler context of regular Mourre theory, our results boil down to an improvement of results obtained recently in [8, 9]....
Analysis of the NTPDase and ecto-5'-nucleotidase profiles in serum-limited Trichomonas vaginalis
Directory of Open Access Journals (Sweden)
Amanda Piccoli Frasson
2012-03-01
Full Text Available Trichomonas vaginalis is a parasite of the human urogenital tract that causes trichomonosis, the most prevalent non-viral sexually transmitted disease. Ectonucleoside triphosphate diphosphohydrolase (NTPDase family members, which hydrolyse extracellular ATP and ADP and ecto-5′-nucleotidase, which hydrolyses AMP, have been characterised in T. vaginalis. For trichomonad culture, the growth medium is supplemented with 10% serum, which is an important source of nutrients, such as adenosine. Here, we investigated the ATP metabolism of T. vaginalis trophozoites from long-term cultures and clinical isolates under limited bovine serum conditions (1% serum. The specific enzymatic activities were expressed as nmol inorganic phosphate (Pi released/min/mg protein, the gene expression patterns were determined by reverse transcriptase-polymerase chain reaction, the extracellular adenine nucleotide hydrolysis was analysed by high performance liquid chromatography and the cell cycle analysis was assessed by flow cytometry. Serum limitation led to the profound activation of NTPDase and ecto-5'-nucleotidase activities. Furthermore, the levels of NTPDase A and B transcripts increased and extracellular ATP metabolism was activated, which led to enhanced ATP hydrolysis and the formation of ADP and AMP. Moreover, the cell cycle was arrested at the G0/G1 stage, which suggested adenosine uptake. Our data suggest that under conditions of serum limitation, NTPDase and ecto-5'-nucleotidase play a role in providing the adenosine required for T. vaginalis growth and that this process contributes to the establishment of parasitism.
Tight Bernoulli tail probability bounds
Dzindzalieta, Dainius
2014-01-01
The purpose of the dissertation is to prove universal tight bounds for deviation from the mean probability inequalities for functions of random variables. Universal bounds shows that they are uniform with respect to some class of distributions and quantity of variables and other parameters. The bounds are called tight, if we can construct a sequence of random variables, such that the upper bounds are achieved. Such inequalities are useful for example in insurance mathematics, for constructing...
Bounded Rationality in Transposition Processes
DEFF Research Database (Denmark)
Vollaard, Hans; Martinsen, Dorte Sindbjerg
2014-01-01
concerns the organisation and financing of national healthcare systems. This article applies the perspective of bounded rationality to explain (irregularities in) the timely and correct transposition of EU directives. The cognitive and organisational constraints long posited by the bounded rationality...... bounded rationality is apparent in the transposition processes in these relatively well-organised countries, future transposition studies should devote greater consideration to the bounded rationality perspective....
Novel Bounds on Marginal Probabilities
Mooij, Joris M.; Kappen, Hilbert J
2008-01-01
We derive two related novel bounds on single-variable marginal probability distributions in factor graphs with discrete variables. The first method propagates bounds over a subtree of the factor graph rooted in the variable, and the second method propagates bounds over the self-avoiding walk tree starting at the variable. By construction, both methods not only bound the exact marginal probability distribution of a variable, but also its approximate Belief Propagation marginal (``belief''). Th...
International Nuclear Information System (INIS)
In structural design of a nuclear power component, stress classification from elastic stress analysis resultants is often used. Alternatively, to improve accuracy, finite element limit analysis may be performed. This paper examines some issues relating to the use of limit analysis; specifically, the treatment of multiple applied loads and the definition of the limit load from analysis using hardening plasticity laws. These are addressed both by detailed analysis for a simple geometry and by using the reference stress approach to estimate the inelastic displacement. The proposals are also applicable to a defect assessment of a cracked component, and treatment of distributed loads. It is shown that multiple or distributed loads should be treated as if they were applied proportionally irrespective of the actual nature of loads, and that the limit load from analysis with general plasticity laws may be estimated using a newly suggested reduced elastic slope method. (author)
Theoretical analysis of saturation and limit cycles in short pulse FEL oscillators
Energy Technology Data Exchange (ETDEWEB)
Piovella, N.; Chaix, P.; Jaroszynski, D. [Commissariat a l`Energie Atomique, Bruyeres-le-Chatel (France)] [and others
1995-12-31
We derive a model for the non linear evolution of a short pulse oscillator from low signal up to saturation in the small gain regime. This system is controlled by only two independent parameters: cavity detuning and losses. Using a closure relation, this model reduces to a closed set of 5 non linear partial differential equations for the EM field and moments of the electron distribution. An analysis of the linearised system allows to define and calculate the eigenmodes characterising the small signal regime. An arbitrary solution of the complete nonlinear system can then be expanded in terms of these eigenmodes. This allows interpreting various observed nonlinear behaviours, including steady state saturation, limit cycles, and transition to chaos. The single mode approximation reduces to a Landau-Ginzburg equation. It allows to obtain gain, nonlinear frequency shift, and efficiency as functions of cavity detuning and cavity losses. A generalisation to two modes allows to obtain a simple description of the limit cycle behaviour, as a competition between these two modes. An analysis of the transitions to more complex dynamics is also given. Finally, the analytical results are compared to the experimental data from the FELIX experiment.
Separable subgroups have bounded packing
Yang, Wen-yuan
2010-01-01
In this note, we prove that separable subgroups have bounded packing in ambient groups. The notion bounded packing was introduced by Hruska-Wise \\cite{HrWi} and in particular, our result confirms a conjecture in \\cite{HrWi} which states each subgroup of a virtually polycyclic group has the bounded packing property.
On bound entanglement assisted distillation
Vedral, V.
1999-01-01
We investigate asymptotic distillation of entanglement in the presence of an unlimited amount of bound entanglement for bi-partite systems. We show that the distillability is still bounded by the relative entropy of entanglement. This offers a strong support to the fact that bound entanglement does not improve distillation of entanglement.
Jolly, William H.
1992-01-01
Relationships defining the ballistic limit of Space Station Freedom's (SSF) dual wall protection systems have been determined. These functions were regressed from empirical data found in Marshall Space Flight Center's (MSFC) Hypervelocity Impact Testing Summary (HITS) for the velocity range between three and seven kilometers per second. A stepwise linear least squares regression was used to determine the coefficients of several expressions that define a ballistic limit surface. Using statistical significance indicators and graphical comparisons to other limit curves, a final set of expressions is recommended for potential use in Probability of No Critical Flaw (PNCF) calculations for Space Station. The three equations listed below represent the mean curves for normal, 45 degree, and 65 degree obliquity ballistic limits, respectively, for a dual wall protection system consisting of a thin 6061-T6 aluminum bumper spaced 4.0 inches from a .125 inches thick 2219-T87 rear wall with multiple layer thermal insulation installed between the two walls. Normal obliquity is d(sub c) = 1.0514 v(exp 0.2983 t(sub 1)(exp 0.5228). Forty-five degree obliquity is d(sub c) = 0.8591 v(exp 0.0428) t(sub 1)(exp 0.2063). Sixty-five degree obliquity is d(sub c) = 0.2824 v(exp 0.1986) t(sub 1)(exp -0.3874). Plots of these curves are provided. A sensitivity study on the effects of using these new equations in the probability of no critical flaw analysis indicated a negligible increase in the performance of the dual wall protection system for SSF over the current baseline. The magnitude of the increase was 0.17 percent over 25 years on the MB-7 configuration run with the Bumper II program code.
Jiao, Yi
2016-01-01
In a diffraction-limited storage ring (DLSR), the momentum acceptance (MA) might be limited by the half integer resonances (HIRs) excited by focusing errors, associated with the large detuning terms from the strong focusing and strong sextupoles required for an ultralow emittance. Taking the High Energy Photon Source (HEPS) as an example and through statistical analysis, we found that the horizontal HIRs have stronger impact on dynamics than the vertical ones; and the probability of MA reduction caused by a HIR is closely correlated with the level of the beta beats at the same plane, but independent of the error sources. For the HEPS design, to reach a small MA-reduction probability of about 1%, the rms amplitude of the beta beats at the nominal tunes should be kept below 1.5% horizontally and 2.5% vertically. The presented analysis can provide useful reference for other DLSR designs.
Sethi, S K; Sethi, Savdeep; Stern, Mark
1998-01-01
We study the existence of D-brane bound states at threshold in Type II string theories. In a number of situations, we can reduce the question of existence to quadrature, and the study of a particular limit of the propagator for the system of D-branes. This involves a derivation of an index theorem for a family of non-Fredholm operators. In support of the conjectured relation between compactified eleven-dimensional supergravity and Type IIA string theory, we show that a bound state exists for two coincident zero-branes. This result also provides support for the conjectured description of M-theory as a matrix model. In addition, we provide further evidence that there are no BPS bound states for two and three-branes twice wrapped on Calabi-Yau vanishing cycles.
International Nuclear Information System (INIS)
Peptide deformylase (PDF) from B. cereus has been overexpressed, purified and crystallized in ligand-free and actinonin-bound forms. Diffraction data have been collected from these crystals to 1.7 and 2.0 Å resolution, respectively. In bacteria, protein expression initiates with an N-formyl group and this needs to be removed in order to ensure proper bacterial growth. These formylation and deformylation processes are unique to eubacteria; therefore, inhibition of these would provide a novel antibacterial therapy. Deformylation is carried out by peptide deformylase (PDF). PDF from Bacillus cereus, one of the major pathogenic bacteria, was cloned into expression plasmid pET-28a (Novagen), overexpressed in Escherichia coli BL21 (DE3) and purified to high quality. Crystals have been obtained of both ligand-free PDF and PDF to which actinonin, a highly potent naturally occurring inhibitor, is bound. Both crystals belong to space group P212121, with unit-cell parameters a = 42.72, b = 44.04, c = 85.19 Å and a = 41.31, b = 44.56, c = 84.47 Å, respectively. Diffraction data were collected to 1.7 Å resolution for the inhibitor-free crystals and to 2.0 Å resolution for the actinonin-bound crystals
Bounding the Heat Trace of a Calabi-Yau Manifold
Fiset, Marc-Antoine
2015-01-01
The SCHOK bound states that the number of marginal deformations of certain two-dimensional conformal field theories is bounded linearly from above by the number of relevant operators. In conformal field theories defined via sigma models into Calabi-Yau manifolds, relevant operators can be estimated, in the point-particle approximation, by the low-lying spectrum of the scalar Laplacian on the manifold. In the strict large volume limit, the standard asymptotic expansion of Weyl and Minakshisundaram-Pleijel diverges with the higher-order curvature invariants. We propose that it would be sufficient to find an a priori uniform bound on the trace of the heat kernel for large but finite volume. As a first step in this direction, we then study the heat trace asymptotics, as well as the actual spectrum of the scalar Laplacian, in the vicinity of a conifold singularity. The eigenfunctions can be written in terms of confluent Heun functions, the analysis of which gives evidence that regions of large curvature will not p...
Organically bound tritium, OBT: Its true constitution
International Nuclear Information System (INIS)
Tritium which is analytically determined to be non exchangeable bound in tissue solids is assumed to be bound to carbon. Furthermore, it is followed, the biochemical Powys's by photosynthesis or enzymatic transfer reactions are retarded by the kinetic isotope effect leading to discrimination of tritium in biomolecules. Contradictory, the logistic growth analysis of plants discloses a larger intrinsic growth rate of OBT than of OBH resulting in tritium accumulation in biomolecules. Exchange experiments providing fractionation factors of 1.4 and 2 confirm this accumulation. In summary, a larger part of the so called OBT is not carbon bound but consists of tritium positioned in hydrogen bridges of biopolymers which have been occupied during formation of the molecules and which became later inacessible for exchange (so called buried hydrogens). Furthermore, there are experimental results indicating even rapid exchange during the 'in vivo'-state but inhibited in the 'in vitro'-state which is commonly given in biosamples prepared for analysis. (author)
The question of an upper bound on entropy
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We discuss the possibility, and significance, of an upper bound on entropy in the light of the arguments of Bekenstein and Unruh and Wald. We obtain a stricter bound than Bekenstein does, and point out some limitations with regard to its significance. (author)
Matroidal Degree-Bounded Minimum Spanning Trees
Zenklusen, Rico
2011-01-01
We consider the minimum spanning tree (MST) problem under the restriction that for every vertex v, the edges of the tree that are adjacent to v satisfy a given family of constraints. A famous example thereof is the classical degree-constrained MST problem, where for every vertex v, a simple upper bound on the degree is imposed. Iterative rounding/relaxation algorithms became the tool of choice for degree-bounded network design problems. A cornerstone for this development was the work of Singh and Lau, who showed for the degree-bounded MST problem how to find a spanning tree violating each degree bound by at most one unit and with cost at most the cost of an optimal solution that respects the degree bounds. However, current iterative rounding approaches face several limits when dealing with more general degree constraints. In particular, when several constraints are imposed on the edges adjacent to a vertex v, as for example when a partition of the edges adjacent to v is given and only a fixed number of elemen...
Analysis of safety limits of the Moroccan TRIGA MARK II research reactor
International Nuclear Information System (INIS)
A 2 MW TRIGA MARK II research reactor has been designed by General Atomics (GA) for the National Centre for Energy and Nuclear Sciences and Techniques (CNESTEN) in Morocco. This TRIGA reactor has the particularity of being the only TRIGA reactor designed to operate at the power level of 2 MW with the use of natural convection cooling. The main objective of this study is to check the ability of the reactor to operate at its nominal power with sufficient safety margins. The analysis of the reactor core starts from the basic reactor cells calculations which were performed for all the reactor cells using the LEOPARD code. The zone averaged group constants provided by cell calculations are used to compute the multiplication factor keff of the cold and clean core using the diffusion theory code Mcrac which is a recent version of the earlier code EXTERMINATOR-2. The main objective of the core calculations is to predict the core excess reactivity in cold zero power conditions and the power peaking factors which are very important data for the thermal hydraulic analysis of the core. For the maximum power peaking factors, our results agree with the values given by the reactor designer. Concerning the core excess reactivity, our results from both XY and RZ core calculations models lead to higher values than the results given by GA (about +2000 pcm). However, we should mention that GA results correspond probably to the minimum core excess reactivity which is guaranteed. The thermal hydraulic analysis of the TRIGA core was performed using the French code FLICA developed in CEA/Saclay for transient and study state thermal hydraulic analysis of a large variety of reactor cores. The objective of this analysis is to evaluate the main safety related parameters of the core and to ensure that they are within the safety limits in any operating conditions. The parameters considered in our study are: maximum fuel temperature, minimum DNBR and maximum void fraction. The obtained results
International Nuclear Information System (INIS)
This report starts with a brief description of the computer system used in Grafenrheinfeld for limiting the power density in the reactor core (DNB-Module) and is then followed by a discussion on methods for verification of the systems' software. The different language levels on which analysis may be performed are presented and criteria for choosing the appropriate language level with regard to verification are given. The program analysis splits the software into sections which are manageable and testable. Then the detailed structure of control flow and data flow as well as the functional properties of these sections are investigated. On certain premises completely analysed sections can be regarded as errorfree, i.e. their failure probability can be assumed to be zero. In addition, test cases for the various software sections are established on the basis of the program analysis. The test strategy comprises the module (sectional) test, partially performed with the test cases mentioned above, as well as an integration test of the entire DNB software. Both tests may be performed automatically - the test embedment is already established to a certain extent - thus allowing execution of a great number of tests; a feature which is extremely important in view of an assessment of quantitative software parameters. (orig.)
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Charles Swartz
2014-06-01
Full Text Available If λ is a scalar sequence space, a series P Zj in a topological vector space Z is λ multiplier convergent in Z if the series P ∞J =1 tj Zj converges in Z for every t = {tj} ∈ λ-If λ satisfies appropriate conditions, a series in a locally convex space X which is λ multiplier convergent in the weak topology is λ multiplier convergent in the original topology ofthe space (the Orlicz-Pettis Theorem but may fail to be λ multiplier convergent in the strong topology of the space. However, we show under apprpriate conditions on the multiplier space λ that the series will have strongly bounded partial sums.
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Francesco Negro
Full Text Available Contractile properties of human motor units provide information on the force capacity and fatigability of muscles. The spike-triggered averaging technique (STA is a conventional method used to estimate the twitch waveform of single motor units in vivo by averaging the joint force signal. Several limitations of this technique have been previously discussed in an empirical way, using simulated and experimental data. In this study, we provide a theoretical analysis of this technique in the frequency domain and describe its intrinsic limitations. By analyzing the analytical expression of STA, first we show that a certain degree of correlation between the motor unit activities prevents an accurate estimation of the twitch force, even from relatively long recordings. Second, we show that the quality of the twitch estimates by STA is highly related to the relative variability of the inter-spike intervals of motor unit action potentials. Interestingly, if this variability is extremely high, correct estimates could be obtained even for high discharge rates. However, for physiological inter-spike interval variability and discharge rate, the technique performs with relatively low estimation accuracy and high estimation variance. Finally, we show that the selection of the triggers that are most distant from the previous and next, which is often suggested, is not an effective way for improving STA estimates and in some cases can even be detrimental. These results show the intrinsic limitations of the STA technique and provide a theoretical framework for the design of new methods for the measurement of motor unit force twitch.
A new type of sharp bounds for ratios of modified Bessel functions
Ruiz-Antolin, D.; J. Segura
2016-01-01
The bounds for the ratios of first and second kind modified Bessel functions of consecutive orders are important quantities appearing in a large number of scientific applications. We obtain new bounds which are accurate in a large region of parameters and which are shaper than previous bounds. The new bounds are obtained by a qualitative analysis of the Riccati equation satisfied by these ratios. A procedure is considered in which the bounds obtained from the analysis of the Riccati equation ...
Analysis of an Arctic sea ice loss model in the limit of a discontinuous albedo
Hill, Kaitlin; Silber, Mary
2015-01-01
As Arctic sea ice extent decreases with increasing greenhouse gases, there is a growing interest in whether there could be a bifurcation associated with its loss, and whether there is significant hysteresis associated with that bifurcation. A challenge in answering this question is that the bifurcation behavior of certain Arctic energy balance models have been shown to be sensitive to how ice-albedo feedback is parameterized. We analyze an Arctic energy balance model in the limit as a smoothing parameter associated with ice-albedo feedback tends to zero, which makes the system piecewise-smooth. Our analysis provides a case study where we use the piecewise-smooth system to explore bifurcation behavior of the smooth system. In this case study, we demonstrate that certain qualitative bifurcation behaviors of the smooth system can have nonsmooth counterparts. We use this perspective to systematically search parameter space. For example, we uncover parameter sets for which the largest transition, with increasing g...
Continuous limit of a crowd motion and herding model: Analysis and numerical simulations
Pietschmann, Jan-Frederik
2011-11-01
In this paper we study the continuum limit of a cellular automaton model used for simulating human crowds with herding behaviour. We derive a system of non-linear partial differential equations resembling the Keller-Segel model for chemotaxis, however with a non-monotone interaction. The latter has interesting consequences on the behaviour of the model\\'s solutions, which we highlight in its analysis. In particular we study the possibility of stationary states, the formation of clusters and explore their connection to congestion. We also introduce an efficient numerical simulation approach based on an appropriate hybrid discontinuous Galerkin method, which in particular allows flexible treatment of complicated geometries. Extensive numerical studies also provide a better understanding of the strengths and shortcomings of the herding model, in particular we examine trapping effects of crowds behind nonconvex obstacles. © American Institute of Mathematical Sciences.
Institute of Scientific and Technical Information of China (English)
Qian Xuede
2008-01-01
Excessive leachate levels in landfills can be a major triggering mechanism for translational failure. The scope of this paper is to present the development of the calculation methods for limit equilibrium analysis of translational failure of landfills and the effects of parametric variation on the factor of safety (FS) of landfills under different leachate buildup conditions. During the development of the calculation methods, 4 leachate buildup conditions are considered. The FS for an interface with high friction angle and low apparent cohesion generally drops much more quickly when leachate levels are increased than that for an interface under inverse conditions. The critical interface of a muitilayer liner system with the lowest FS for the entire waste mass can shift from one to another with changes in the leachate levels. The different interfaces of a multilayer liner will have different FS-values under different leachate buildup conditions.
Left ventricular time volume curve analysis in the detection of limited ischaemic heart disease
International Nuclear Information System (INIS)
The aim of the study was to determine whether limited coronary artery disease (CAD) could be accurately detected using the Cardiac Gated Blood Pool (CGBP) scan with exercise. Regional left ventricular time volume curves (RLTVD) were generated from 52 studies (46 patients: 22 normals, 24 abnormals). The parameters assessed both globally and regionally and at rest (R) and exercise (Ex) were: (1) the ejection fraction (EF) (2) the change in ejection fraction from R to Ex (δEF) (3) an early contraction index (ECI) (4) a maximal emptying index (DR) and (5) a maximal refilling index (AR). After careful analysis of these parameters it was decided that our diagnostic criteria would rely on the following: (1) the EF at R and Ex (2) the δ EF (3) the ECI at Ex (4) the AR at Ex This study showed that both the sensitivity and the specificity of the CGBP scan can be improved considerably with the inclusion of RLTVC from the levels obtained when the EF parameters alone are considered. It is possible with this technique to accurately diagnose limited CAD. (Author)
When to start antiretroviral therapy in resource-limited settings: a human rights analysis
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Calmy Alexandra
2010-03-01
Full Text Available Abstract Background Recent evidence from developed and developing countries shows clear clinical and public health benefit to starting antiretroviral therapy (ART earlier. While discussions about when to start ART have often focused on the clinical risks and benefits, the main issue is one of fair limit-setting. We applied a human rights framework to assess a policy of early treatment initiation according to the following criteria: public-health purpose; likely effectiveness; specificity; human rights burdens and benefits; potential for less restrictive approaches; and fair administration. Discussion According to our analysis, a policy of earlier ART initiation would better serve both public health and human rights objectives. We highlight a number of policy approaches that could be taken to help meet this aim, including increased international financial support, alternative models of care, and policies to secure the most affordable sources of appropriate antiretroviral drugs. Summary Widespread implementation of earlier ART initiation is challenging in resource-limited settings. Nevertheless, rationing of essential medicines is a restriction of human rights, and the principle of least restriction serves to focus attention on alternative measures such as adapting health service models to increase capacity, decreasing costs, and seeking additional international funding. Progressive realisation using well-defined steps will be necessary to allow for a phased implementation as part of a framework of short-term targets towards nationwide policy adoption, and will require international technical and financial support.
Analysis of Optical CDMA Signal Transmission: Capacity Limits and Simulation Results
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Lawrence R. Chen
2005-06-01
Full Text Available We present performance limits of the optical code-division multiple-access (OCDMA networks. In particular, we evaluate the information-theoretical capacity of the OCDMA transmission when single-user detection (SUD is used by the receiver. First, we model the OCDMA transmission as a discrete memoryless channel, evaluate its capacity when binary modulation is used in the interference-limited (noiseless case, and extend this analysis to the case when additive white Gaussian noise (AWGN is corrupting the received signals. Next, we analyze the benefits of using nonbinary signaling for increasing the throughput of optical CDMA transmission. It turns out that up to a fourfold increase in the network throughput can be achieved with practical numbers of modulation levels in comparison to the traditionally considered binary case. Finally, we present BER simulation results for channel coded binary and M-ary OCDMA transmission systems. In particular, we apply turbo codes concatenated with Reed-Solomon codes so that up to several hundred concurrent optical CDMA users can be supported at low target bit error rates. We observe that unlike conventional OCDMA systems, turbo-empowered OCDMA can allow overloading (more active users than is the length of the spreading sequences with good bit error rate system performance.
International Nuclear Information System (INIS)
In this paper study of the Saturated Iron Core Superconducting Fault Current Limiter (SISFCL) has been carried out. Since in an SISFCL, the iron core plays a key role in distributing the magnetic flux, the hysteresis property of the core material has been introduced in a mathematical model to get a more accurate result. In this paper the Jiles–Atherton hysteresis model has been used for modeling the core. The equations are solved through numerical method and performances of SISFCL are analyzed for both normal and fault conditions. On further analysis it is observed that for suppression of higher value of fault current a high voltage develops across the DC source. Hence there is a chance of the DC source being damaged by the rise in voltage under fault condition. In order to protect the DC source, a shorted ring is introduced in the SISFCL circuit and its effects have been analyzed. It is noticed that the shorted ring has successfully reduced the voltage across the DC coil during fault condition while the performance of the limiter remains the same. - Highlights: • Mathematical modeling of SISFCL has been established. • Hysteresis effect has been included using J–A model. • Mathematical model of SISFCL using the Shorted Ring have been established. • Comparisons are drawn between the responses with and without shorted ring
International Nuclear Information System (INIS)
The validity limits of a linear analysis for a resistive instability are determined. The effects of mode-coupling on the magnetic field structure are investigated in the reconnecting layer. Given an equilibrium magnetic field and a perturbation field, the conditions are found under which the equations for the magnetic field lines of force can be expressed in Hamiltonian form. These conditions can be fulfilled by a resistive instability. Consequently, in a simple equilibrium magnetic field the resistive eigenmodes have been analytically derived. This result is used to give an explicit expression of the Hamiltonian for field-line equations when two resistive eigenmodes are taken into account. The analytical form of the resulting Hamiltonian coincides with the so-called paradigm Hamiltonian (1.5 degrees of freedom) for which the Escande-Doveil renormalization procedure leads to an explicit expression for the global stochasticity threshold. Thus it can be shown that any pair of modes - in a suitable range of parameters - yields spatial stochasticity of magnetic field lines when the perturbation amplitude is still very low. Hence a limit of validity of the linear theory can be found. The linear phase of the resistive instability turns out to be relevant only to describe the onset of the instability itself. (author)
The limiting events transient analysis by RETRAN02 and VIPRE01 for an ABWR
International Nuclear Information System (INIS)
This paper describes the transient analysis of generator load rejection (LR) and One Turbine Control Valve Closure (OTCVC) events for Lungmen nuclear power plant (LMNPP). According to the Critical Power Ratio (CPR) criterion, the Preliminary Safety Analysis Report (PSAR) concluded that LR and OTCVC are the first and second limiting events respectively. In addition, the fuel type is changed from GE12 to GE14 now. It's necessary to re-analyze these two events for safety consideration. In this study, to quantify the impact to reactor, the difference of initial critical power ratio (ICPR) and minimum critical power ratio (MCPR), ie. ΔCPR is calculated. The ΔCPRs of the LR and OTCVC events are calculated with the combination of RETRAN02 and VIPRE01 codes. In RETRAN02 calculation, a thermal-hydraulic model was prepared for the transient analysis. The data including upper plenum pressure, core inlet flow, normalized power, and axial power shapes during transient are furthermore submitted into VIPRE01 for ΔCPR calculation. In VIPRE01 calculation, there was a hot channel model built to simulate the hottest fuel bundle. Based on the thermal-hydraulic data from RETRAN02, the ΔCPRs are calculated by VIPRE01 hot channel model. Additionally, the different TCV control modes are considered to study the influence of different TCV closure curves on transient behavior. Meanwhile, sensitivity studies including different initial system pressure and different initial power/flow conditions are also considered. Based on this analysis, the maximum ΔCPRs for LR and OTCVC are 0.162 and 0.191 respectively. According CPR criterion, the result shows that the impact caused by OTCVC event leads to be larger than LR event. (author)
Tromson-Carli, A.; Svob, L.; Marfaing, Y.; Druilhe, R.; Desjonqueres, F.; Triboulet, R.
1991-12-01
X-ray double diffraction and photoluminescence experiments were performed on a series of CdTe layers grown by MOVPE on CdTe, CdZnTe and GaAs substrates. Some correlation appears between the measured rocking curve widths and impurity-bound exciton linewidth. To analyze these results, a model relating the exciton linewidth to the average strain induced by an array of random dislocations has been developed. It appears that X-ray diffraction is also sensitive to non-random dislocation configurations which do not affect luminescence linewidth.
Bounding the Higgs width at the LHC: complementary results from H→WW
Energy Technology Data Exchange (ETDEWEB)
Campbell, John M.; Ellis, R. Keith; Williams, Ciaran
2014-03-01
We investigate the potential of the process gg → H→ WW to provide bounds on the Higgs width. Recent studies using off-shell H→ ZZ events have shown that Run 1 LHC data can constrain the Higgs width, $\\Gamma_H < (25-45) \\Gamma_{H}^{\\rm SM}$. Using 20 fb-1 of 8 TeV ATLAS data, we estimate a bound on the Higgs boson width from the WW channel between $\\Gamma_H < (100-500) \\Gamma_H^{SM}$. The large spread in limits is due to the range of cuts applied in the existing experimental analysis. The stricter cuts designed to search for the on-shell Higgs boson limit the potential number of off-shell events, weakening the constraints. As some of the cuts are lifted the bounds improve. We show that there is potential in the high transverse mass region to produce upper bounds of the order of $(25-50) \\Gamma_H^{SM}$, depending strongly on the level of systematic uncertainty that can be obtained. Thus, if these systematics can be controlled, a constraint on the Higgs boson width from the H → WW$ decay mode can complement a corresponding limit from H → ZZ.
Nanogram-scale preparation and NMR analysis for mass-limited small volatile compounds.
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Satoshi Nojima
Full Text Available Semiochemicals are often produced in infinitesimally small quantities, so their isolation requires large amounts of starting material, not only requiring significant effort in sample preparation, but also resulting in a complex mixture of compounds from which the bioactive compound needs to be purified and identified. Often, compounds cannot be unambiguously identified by their mass spectra alone, and NMR analysis is required for absolute chemical identification, further exacerbating the situation because NMR is relatively insensitive and requires large amounts of pure analyte, generally more than several micrograms. We developed an integrated approach for purification and NMR analysis of <1 µg of material. Collections from high performance preparative gas-chromatography are directly eluted with minimal NMR solvent into capillary NMR tubes. With this technique, (1H-NMR spectra were obtained on 50 ng of geranyl acetate, which served as a model compound, and reasonable H-H COSY NMR spectra were obtained from 250 ng of geranyl acetate. This simple off-line integration of preparative GC and NMR will facilitate the purification and chemical identification of novel volatile compounds, such as insect pheromones and other semiochemicals, which occur in minute (sub-nanogram, and often limited, quantities.
LIMITS OF SWOT ANALYSIS AND THEIR IMPACT ON DECISIONS IN EARLY WARNING SYSTEMS
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Florin POPESCU
2015-04-01
Full Text Available SWOT (strengths, weaknesses, opportunities, threats analysis is useful in the decision-making process – crucial to any organization manager and/or strategist. This study aims to add value to the existing literature on SWOT, indicating its use and limitations, showing the need to link SWOT to other strategic tools and methodologies. As the current environment is turbulent and unpredictable, and economic cycles no longer comply with traditional rules, the precaution has become extremely important. That’s why SWOT should be supplemented with newer dynamic analysis capabilities and strategy tools, as early warning and opportunities system (EWOS, which can provide crucial inputs for scenario building, strategic thinking and decisions. EWOS is a novel approach based on three concepts that contribute to the ability of organization/project managers to develop outstanding capacity to "understand" and "benefit" in identifying opportunities and threats: (i business and competitive intelligence; (ii early warning thinking; (iii strategic thinking in decision making process. EWOS is of practical use for strategists and decision makers.
International Nuclear Information System (INIS)
Adenylate kinase (AK) from D. gigas was purified and crystallized in three different metal-bound forms: Zn2+–AK, Co2+–AK and Fe2+–AK. Adenylate kinase (AK; ATP:AMP phosphotransferase; EC 2.7.4.3) is involved in the reversible transfer of the terminal phosphate group from ATP to AMP. AKs contribute to the maintenance of a constant level of cellular adenine nucleotides, which is necessary for the energetic metabolism of the cell. Three metal ions, cobalt, zinc and iron(II), have been reported to be present in AKs from some Gram-negative bacteria. Native zinc-containing AK from Desulfovibrio gigas was purified to homogeneity and crystallized. The crystals diffracted to beyond 1.8 Å resolution. Furthermore, cobalt- and iron-containing crystal forms of recombinant AK were also obtained and diffracted to 2.0 and 3.0 Å resolution, respectively. Zn2+–AK and Fe2+–AK crystallized in space group I222 with similar unit-cell parameters, whereas Co2+–AK crystallized in space group C2; a monomer was present in the asymmetric unit for both the Zn2+–AK and Fe2+–AK forms and a dimer was present for the Co2+–AK form. The structures of the three metal-bound forms of AK will provide new insights into the role and selectivity of the metal in these enzymes
Echeverria, Alex; Mendez, Rene A; Orchard, Marcos
2016-01-01
Context. The best precision that can be achieved to estimate the location of a stellar-like object is a topic of permanent interest in the astrometric community. Aims. We analyse bounds for the best position estimation of a stellar-like object on a CCD detector array in a Bayesian setting where the position is unknown, but where we have access to a prior distribution. In contrast to a parametric setting where we estimate a parameter from observations, the Bayesian approach estimates a random object (i.e., the position is a random variable) from observations that are statistically dependent on the position. Methods. We characterize the Bayesian Cramer-Rao (CR) that bounds the minimum mean square error (MMSE) of the best estimator of the position of a point source on a linear CCD-like detector, as a function of the properties of detector, the source, and the background. Results. We quantify and analyse the increase in astrometric performance from the use of a prior distribution of the object position, which is ...
Bounds on eigenvalues and singular values of interval matrices
Hladik, Milan; Daney, David; Tsigaridas, Elias P.,
2009-01-01
We study bounds on eigenvalues of interval matrices, and our aim is to develop fast computable formulae that produce as-sharp-as-possible bounds. We consider two cases: general (unsymmetric) and symmetric interval matrices. We focus on the latter case, since on one hand these such interval matrices have many applications in mechanics and engineering, and on the other many results from classical matrix analysis could be applied to them. We also provide bounds for the singular values of (genera...
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Peeyush Sahay
2009-10-01
Full Text Available Breath analysis, a promising new field of medicine and medical instrumentation, potentially offers noninvasive, real-time, and point-of-care (POC disease diagnostics and metabolic status monitoring. Numerous breath biomarkers have been detected and quantified so far by using the GC-MS technique. Recent advances in laser spectroscopic techniques and laser sources have driven breath analysis to new heights, moving from laboratory research to commercial reality. Laser spectroscopic detection techniques not only have high-sensitivity and high-selectivity, as equivalently offered by the MS-based techniques, but also have the advantageous features of near real-time response, low instrument costs, and POC function. Of the approximately 35 established breath biomarkers, such as acetone, ammonia, carbon dioxide, ethane, methane, and nitric oxide, 14 species in exhaled human breath have been analyzed by high-sensitivity laser spectroscopic techniques, namely, tunable diode laser absorption spectroscopy (TDLAS, cavity ringdown spectroscopy (CRDS, integrated cavity output spectroscopy (ICOS, cavity enhanced absorption spectroscopy (CEAS, cavity leak-out spectroscopy (CALOS, photoacoustic spectroscopy (PAS, quartz-enhanced photoacoustic spectroscopy (QEPAS, and optical frequency comb cavity-enhanced absorption spectroscopy (OFC-CEAS. Spectral fingerprints of the measured biomarkers span from the UV to the mid-IR spectral regions and the detection limits achieved by the laser techniques range from parts per million to parts per billion levels. Sensors using the laser spectroscopic techniques for a few breath biomarkers, e.g., carbon dioxide, nitric oxide, etc. are commercially available. This review presents an update on the latest developments in laser-based breath analysis.
Lower bounds for designs in symmetric spaces
Eidelstein, Noa
2010-01-01
We prove lower bounds on designs in spaces with a large group of symmetries. These spaces include globally symmetric Riemannian spaces (of any rank) and commutative association schemes with 1-transitive group of symmetries. Our bounds are, in general, implicit, relying on estimates on the spectral behavior of certain symmetry-invariant linear operators. They reduce to the first linear programming bound for designs in globally symmetric Riemannian spaces of rank 1 or in distance regular graphs. The proofs are different though, coming from viewpoint of abstract harmonic analysis in symmetric spaces. As a dividend we obtain the following geometric fact: a design is large because a union of "spherical caps" around its points "covers" the whole space.
Czech, Christopher
The field of meta-materials engineering has largely expanded mechanical design possibilities over the last two decades; some notable design advances include the systematic engineering of negative Poisson's ratio materials and functionally graded materials, materials designed for optimal electronic and thermo-mechanical performances, and the design of materials under uncertainty. With these innovations, the systematic engineering of materials for design-specific uses is becoming more common in industrial and military uses. The motivation for this body of research is the design of the shear beam for a non-pneumatic wheel. Previously, a design optimization of a finite element model of the non-pneumatic wheel was completed, where a linear elastic material was simulated in the shear beam to reduce hysteretic energy losses. As part of the optimization, a set of optimal orthotropic material properties and other geometric properties were identified for the shear beam. Given that no such natural linear elastic material exists, a meta-material can be engineered that meets these properties using the aforementioned tools. However, manufacturing constraints prevent the use of standard homogenization analysis and optimization tools in the engineering of the shear beam due to limitations in the accuracy of the homogenization process for thin materials. In this research, the more general volume averaging analysis is shown to be an accurate tool for meta-material analysis for engineering thin-layered materials. Given an accurate analysis method, several optimization formulations are proposed, and optimality conditions are derived to determine the most mathematically feasible and numerically reliable formulation for topology optimization of a material design problem using a continuous material interpolation over the design domain. This formulation is implemented to engineer meta-materials for problems using the volume averaging analysis, which includes the use of variable linking
Recent advances in bound state quantum electrodynamics
International Nuclear Information System (INIS)
Recent developments are reviewed in four areas of computational quantum electrodynamics: a new relativistic two-body formalism equal in rigor to the Bethe-Salpeter formalism but with strong calculational advantages is discussed; recent work on the computation of the decay rate of bound systems (positronium in particular) is presented; limits on possible composite structure of leptons are discussed; a new multidimensional integration program ('VEGAS') suitable for higher order calculations is presented
Thermodynamic Upper Bound on Broadband Light Coupling with Photonic Structures
Yu, Zongfu
2012-10-01
The coupling between free space radiation and optical media critically influences the performance of optical devices. We show that, for any given photonic structure, the sum of the external coupling rates for all its optical modes are subject to an upper bound dictated by the second law of thermodynamics. Such bound limits how efficient light can be coupled to any photonic structure. As one example of application, we use this upper bound to derive the limit of light absorption in broadband solar absorbers. © 2012 American Physical Society.
Energy Technology Data Exchange (ETDEWEB)
Gore, B.R.; Dukelow, J.S. Jr.; Mitts, T.M.; Nicholson, W.L. [Pacific Northwest Lab., Richland, WA (United States)
1995-10-01
This report presents a limited assessment of the conservatism of the Accident Sequence Evaluation Program (ASEP) human reliability analysis (HRA) procedure described in NUREG/CR-4772. In particular, the, ASEP post-accident, post-diagnosis, nominal HRA procedure is assessed within the context of an individual`s performance of critical tasks on the simulator portion of requalification examinations administered to nuclear power plant operators. An assessment of the degree to which operator perforn:Lance during simulator examinations is an accurate reflection of operator performance during actual accident conditions was outside the scope of work for this project; therefore, no direct inference can be made from this report about such performance. The data for this study are derived from simulator examination reports from the NRC requalification examination cycle. A total of 4071 critical tasks were identified, of which 45 had been failed. The ASEP procedure was used to estimate human error probability (HEP) values for critical tasks, and the HEP results were compared with the failure rates observed in the examinations. The ASEP procedure was applied by PNL operator license examiners who supplemented the limited information in the examination reports with expert judgment based upon their extensive simulator examination experience. ASEP analyses were performed for a sample of 162 critical tasks selected randomly from the 4071, and the results were used to characterize the entire population. ASEP analyses were also performed for all of the 45 failed critical tasks. Two tests were performed to assess the bias of the ASEP HEPs compared with the data from the requalification examinations. The first compared the average of the ASEP HEP values with the fraction of the population actually failed and it found a statistically significant factor of two bias on the average.
International Nuclear Information System (INIS)
This report presents a limited assessment of the conservatism of the Accident Sequence Evaluation Program (ASEP) human reliability analysis (HRA) procedure described in NUREG/CR-4772. In particular, the, ASEP post-accident, post-diagnosis, nominal HRA procedure is assessed within the context of an individual's performance of critical tasks on the simulator portion of requalification examinations administered to nuclear power plant operators. An assessment of the degree to which operator perforn:Lance during simulator examinations is an accurate reflection of operator performance during actual accident conditions was outside the scope of work for this project; therefore, no direct inference can be made from this report about such performance. The data for this study are derived from simulator examination reports from the NRC requalification examination cycle. A total of 4071 critical tasks were identified, of which 45 had been failed. The ASEP procedure was used to estimate human error probability (HEP) values for critical tasks, and the HEP results were compared with the failure rates observed in the examinations. The ASEP procedure was applied by PNL operator license examiners who supplemented the limited information in the examination reports with expert judgment based upon their extensive simulator examination experience. ASEP analyses were performed for a sample of 162 critical tasks selected randomly from the 4071, and the results were used to characterize the entire population. ASEP analyses were also performed for all of the 45 failed critical tasks. Two tests were performed to assess the bias of the ASEP HEPs compared with the data from the requalification examinations. The first compared the average of the ASEP HEP values with the fraction of the population actually failed and it found a statistically significant factor of two bias on the average
International Nuclear Information System (INIS)
Solid material in protoplanetary disks will suffer one of two fates after the epoch of planet formation; either being bound up into planetary bodies, or remaining in smaller planetesimals to be ground into dust. These end states are identified through detection of sub-stellar companions by periodic radial velocity (or transit) variations of the star, and excess emission at mid- and far-infrared wavelengths, respectively. Since the material that goes into producing the observable outcomes of planet formation is the same, we might expect these components to be related both to each other and their host star. Heretofore, our knowledge of planetary systems around other stars has been strongly limited by instrumental sensitivity. In this work, we combine observations at far-infrared wavelengths by IRAS, Spitzer, and Herschel with limits on planetary companions derived from non-detections in the 16 year Anglo-Australian Planet Search to clarify the architectures of these (potential) planetary systems and search for evidence of correlations between their constituent parts. We find no convincing evidence of such correlations, possibly owing to the dynamical history of the disk systems, or the greater distance of the planet-search targets. Our results place robust limits on the presence of Jupiter analogs which, in concert with the debris disk observations, provides insights on the small-body dynamics of these nearby systems.
Energy Technology Data Exchange (ETDEWEB)
Wittenmyer, Robert A.; Marshall, Jonathan P., E-mail: rob@phys.unsw.edu.au [School of Physics, UNSW Australia, Sydney 2052 (Australia)
2015-02-01
Solid material in protoplanetary disks will suffer one of two fates after the epoch of planet formation; either being bound up into planetary bodies, or remaining in smaller planetesimals to be ground into dust. These end states are identified through detection of sub-stellar companions by periodic radial velocity (or transit) variations of the star, and excess emission at mid- and far-infrared wavelengths, respectively. Since the material that goes into producing the observable outcomes of planet formation is the same, we might expect these components to be related both to each other and their host star. Heretofore, our knowledge of planetary systems around other stars has been strongly limited by instrumental sensitivity. In this work, we combine observations at far-infrared wavelengths by IRAS, Spitzer, and Herschel with limits on planetary companions derived from non-detections in the 16 year Anglo-Australian Planet Search to clarify the architectures of these (potential) planetary systems and search for evidence of correlations between their constituent parts. We find no convincing evidence of such correlations, possibly owing to the dynamical history of the disk systems, or the greater distance of the planet-search targets. Our results place robust limits on the presence of Jupiter analogs which, in concert with the debris disk observations, provides insights on the small-body dynamics of these nearby systems.
DEFF Research Database (Denmark)
Nielsen, Ulrik Dam; Friis-Hansen, Peter; Jensen, Jørgen Juncher
2009-01-01
procedure is based on parallel system analysis, and the paper derives and describes the main ideas. The concept is illustrated by an example, where the limit state of a non-linear ship response is considered. The results from the parallel system analysis are in agreement with corresponding Monte Carlo...
Directory of Open Access Journals (Sweden)
Olumuyiwa Tolulope APANISILE
2014-12-01
Full Text Available The study examines the effect of military expenditure on output in Nigeria both in the short-run and in the long-run period. In addition, it verified whether military expenditure is an economically non-contributive activity using ARDL bounds testing approach to co-integration. Results showed that military spending has negative and significant effect on output in the short-run but positive and significant effect in the long-run. Labour and capital have positive and significant effects both in the long-run and short-run. In addition, labour has the highest coefficient (3.0709 in the long-run.The study concludes that government should reduce its expenditure on defense and concentrate more on human capital development, since military spending contributes nothing to output in the short-run.
International Nuclear Information System (INIS)
Crystals of palindromic SBE DNA-bound Smad1 MH1 domain diffracting to 2.7 Å resolution have been obtained. The bone morphogenetic protein (BMP) signalling pathway regulates diverse processes such as cell differentiation, anterior/posterior axis specification, cell growth and the formation of extra-embryonic tissues. The transcription factor Smad1 relays the BMP signal from the cytoplasm to the nucleus, where it binds short DNA-sequence motifs and regulates gene expression. However, how Smad1 selectively targets particular genomic regions is poorly understood. In order to understand the physical basis of the specific interaction of Smad1 with DNA and to contrast it with the highly homologous but functionally distinct Smad3 protein, the DNA-binding Mad-homology 1 (MH1) domain of Smad1 was cocrystallized with a 17-mer palindromic Smad-binding element (SBE). The extensive optimizations of the length, binding-site spacing and terminal sequences of the DNA element in combination with the other crystallization parameters necessary for obtaining diffraction-quality crystals are described here. A 2.7 Å resolution native data set was collected at the National Synchrotron Radiation Research Centre, Taiwan, from crystals grown in a solution containing 0.2 M ammonium tartrate dibasic, 20% PEG 3350, 3% 2-propanol and 10% glycerol. The data set was indexed and merged in space group P222, with unit-cell parameters a = 73.94, b = 77.49, c = 83.78 Å, α = β = γ = 90°. The solvent content in the unit cell is consistent with the presence of two Smad1 MH1 molecules bound to the duplex DNA in the asymmetric unit
Shibata, Mikihiro; Kandori, Hideki
2007-12-01
Bacteriorhodopsin (BR), a membrane protein found in Halobacterium salinarum, functions as a light-driven proton pump. The Schiff base region has a quadropolar structure with positive charges located at the protonated Schiff base and Arg82, and counterbalancing negative charges located at Asp85 and Asp212 (Figure 1A). It is known that BR lacks a proton-pumping activity if Asp85 or Asp212 is neutralized by mutation. On the other hand, binding of C1- brings different effects for pumping functions in mutants at D85 and D212 position. While C1--bound D85T and D85S pump C1-, photovoltage measurements suggested that C1--bound D212N pumps protons at low pH. In this study, we measured low-temperature FTIR spectra of D85S and D212N containing various halides to compare the halide binding site of both proteins. In the case of D85S, the N-D stretching vibrations of the Schiff base were halide-dependent. This result suggests that the halide is a hydrogen-bond acceptor of the Schiff base, being consistent with the X-ray crystal structure. On the other hand, no halide dependence was observed for vibrational bands of the retinal skeleton and the Schiff base in the D212N mutant. This result suggests that the halide does not form a hydrogen bond with the Schiff base directly, unlike the mutation at D85 position. Halide-dependent water bands in the Schiff base region also differ between D85S and D212N. From these results, halide binding site of both proteins and role of two negative charges in BR will be discussed.
Directory of Open Access Journals (Sweden)
van Duijn Cornelia
2010-10-01
Full Text Available Abstract Background Presence of interaction between a genotype and certain factor in determination of a trait's value, it is expected that the trait's variance is increased in the group of subjects having this genotype. Thus, test of heterogeneity of variances can be used as a test to screen for potentially interacting single-nucleotide polymorphisms (SNPs. In this work, we evaluated statistical properties of variance heterogeneity analysis in respect to the detection of potentially interacting SNPs in a case when an interaction variable is unknown. Results Through simulations, we investigated type I error for Bartlett's test, Bartlett's test with prior rank transformation of a trait to normality, and Levene's test for different genetic models. Additionally, we derived an analytical expression for power estimation. We showed that Bartlett's test has acceptable type I error in the case of trait following a normal distribution, whereas Levene's test kept nominal Type I error under all scenarios investigated. For the power of variance homogeneity test, we showed (as opposed to the power of direct test which uses information about known interacting factor that, given the same interaction effect, the power can vary widely depending on the non-estimable direct effect of the unobserved interacting variable. Thus, for a given interaction effect, only very wide limits of power of the variance homogeneity test can be estimated. Also we applied Levene's approach to test genome-wide homogeneity of variances of the C-reactive protein in the Rotterdam Study population (n = 5959. In this analysis, we replicate previous results of Pare and colleagues (2010 for the SNP rs12753193 (n = 21, 799. Conclusions Screening for differences in variances among genotypes of a SNP is a promising approach as a number of biologically interesting models may lead to the heterogeneity of variances. However, it should be kept in mind that the absence of variance heterogeneity for
Institute of Scientific and Technical Information of China (English)
刘怡文; 李伟琴
2002-01-01
Strand Spaces serve as a model of security protocol analysis. In this paper, the main characteristics of Strand Spaces are briefly introduced, and its advantages and disadvantages are presented . An algorithm of building an ideal model of a protocol is proposed, which is used to bound both the abilities of the penetrator and the number of concurrent protocol runs. Combining Model Checking and Strand Spaces, a method is proposed to use both the automatic reasoning mechanism of the Model Checking and the bounds on security protocol analysis to achieve effective analysis of security protocols, avoiding state explosion problems.%Strand Spaces是一种用于分析安全协议的机器证明方法.简要介绍了Strand Spaces的基本特点,分析了其优劣,提出了构造协议的理想子环的算法,并以此来约束协议入侵者的能力和协议并行运行的次数.将模型检查与Strand Spaces结合在一起,提出了一种综合分析方法来验证协议的安全特性,该方法可充分发挥模型检查与Strand Spaces二者的优势.
Energy Technology Data Exchange (ETDEWEB)
Brodsky, Stanley J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Gardner, Susan [Univ. of Kentucky, Lexington, KY (United States)
2015-07-20
Intrinsic heavy quarks in hadrons emerge from the non-perturbative structure of a hadron bound state and are a rigorous prediction of QCD. Lattice QCD calculations indicate significant intrinsic charm and strangeness probabilities. Since the light-front momentum distribution of the Fock states is maximal at equal rapidity, intrinsic heavy quarks carry significant fractions of the hadron momentum. The presence of Fock states with intrinsic strange, charm, or bottom quarks in hadrons lead to an array of novel physics phenomena. Accurate determinations of the heavy-quark distributions in the proton are needed to interpret Tevatron and LHC measurements as probed of physics beyond the Standard Model.
The Second Painlev\\'e Equation in the Large-Parameter Limit I: Local Asymptotic Analysis
Joshi, Nalini
1997-01-01
In this paper, we find all possible asymptotic behaviours of the solutions of the second Painlev\\'e equation $y''=2y^3+xy +\\alpha$ as the parameter $\\alpha\\to\\infty$ in the local region $x\\ll\\alpha^{2/3}$. We prove that these are asymptotic behaviours by finding explicit error bounds. Moreover, we show that they are connected and complete in the sense that they correspond to all possible values of initial data given at a point in the local region.
International Nuclear Information System (INIS)
The National Synchrotron Light Source Safety Analysis Reports (1), (2), (3), BNL reports number-sign 51584, number-sign 52205 and number-sign 52205 (addendum) describe the basic Environmental Safety and Health issues associated with the department's operations. They include the operating envelope for the Storage Rings and also the rest of the facility. These documents contain the operational limits as perceived prior or during construction of the facility, much of which still are appropriate for current operations. However, as the machine has matured, the experimental program has grown in size, requiring more supervision in that area. Also, machine studies have either verified or modified knowledge of beam loss modes and/or radiation loss patterns around the facility. This document is written to allow for these changes in procedure or standards resulting from their current mode of operation and shall be used in conjunction with the above reports. These changes have been reviewed by NSLS and BNL ES and H committee and approved by BNL management
THE CRITICAL ANALYSIS OF LIMITED SOUTH ASIAN CORPORATE GOVERNANCE STANDARDS AFTER FINANCIAL CRISIS
Directory of Open Access Journals (Sweden)
Dinh Tran Ngoc Huy
2015-12-01
Full Text Available After the recent global crisis, corporate scandals and bankruptcy in US and Europe, there is some certain evidence on weak corporate governance, risk management and audit system. The 2009 India Code of Corporate Governance also revealed that during the crisis time, there are certain weaknesses although corporate structure is fairly durable. Hence, this paper chooses a different analytical approach and among its aims is to give some systematic opinions. First, it classifies limited South Asian representative corporate governance (CG standards into two (2 groups: India and Malaysia latest CG principles covered in group 1 and, group 2, including corporate governance principle from Thailand and Indonesia, so-called relative good CG group, while it uses ACCA and OECD and ICGN principles as reference. Second, it, through analysis, identifies differences and advantages between above set of standards which are and have been used as reference principles for many relevant organizations. Third, it establishes a selected comparative set of standards for South Asian representative corporate governance system in accordance to international standards. Last but not least, this paper covers some ideas and policy suggestions.
Assessment of the statistics of the Strehl ratio: predictions of central limit theorem analysis
Tyler, Glenn A.
2006-11-01
For a beam propagating through turbulence, the statistics of the Strehl ratio are determined by recognizing that the real and imaginary parts of the on-axis far-field pattern can be represented as the sum of many contributions from the aperture. With this in mind, the central limit theorem (CLT) can be used to develop the statistics of the real and imaginary parts of the optical field, which through the appropriate mathematical manipulations as described here can then be used to develop the probability distribution of the far-field irradiance. The results obtained in this way (which we call the CLT theory or analysis) provide an analytic expression that agrees with the results of detailed wave-optics simulations. This provides an approach by which the statistics of the Strehl ratio can be rapidly determined. A key feature of this work is that the analytic results depend on the values of a few relevant turbulence parameters that include r0,fG, and σ2l. Therefore, a measurement of these parameters at various sites of interest allows us to rapidly assess the detailed nature of the statistical fluctuations of the far-field irradiance that will be experienced at these locations.
Bounds for Asian basket options
Deelstra, Griselda; Diallo, Ibrahima; Vanmaele, Michèle
2008-09-01
In this paper we propose pricing bounds for European-style discrete arithmetic Asian basket options in a Black and Scholes framework. We start from methods used for basket options and Asian options. First, we use the general approach for deriving upper and lower bounds for stop-loss premia of sums of non-independent random variables as in Kaas et al. [Upper and lower bounds for sums of random variables, Insurance Math. Econom. 27 (2000) 151-168] or Dhaene et al. [The concept of comonotonicity in actuarial science and finance: theory, Insurance Math. Econom. 31(1) (2002) 3-33]. We generalize the methods in Deelstra et al. [Pricing of arithmetic basket options by conditioning, Insurance Math. Econom. 34 (2004) 55-57] and Vanmaele et al. [Bounds for the price of discrete sampled arithmetic Asian options, J. Comput. Appl. Math. 185(1) (2006) 51-90]. Afterwards we show how to derive an analytical closed-form expression for a lower bound in the non-comonotonic case. Finally, we derive upper bounds for Asian basket options by applying techniques as in Thompson [Fast narrow bounds on the value of Asian options, Working Paper, University of Cambridge, 1999] and Lord [Partially exact and bounded approximations for arithmetic Asian options, J. Comput. Finance 10 (2) (2006) 1-52]. Numerical results are included and on the basis of our numerical tests, we explain which method we recommend depending on moneyness and time-to-maturity.
Institute of Scientific and Technical Information of China (English)
LIU Li-Guo; TIAN Cheng-Lin; CHEN Ping-Xing; YUAN Nai-Chang
2009-01-01
We derive an analytical lower bound on the concurrence for bipartite quantum systems with an improved computable cross norm or realignment criterion and an improved positive partial transpose criterion respectively.Furthermore we demonstrate that our bound is better than that obtained from the local uncertainty relations criterion with optimal local orthogonal observables which is known as one of the best estimations of concurrence.
Scattering theory methods for bound state problems
International Nuclear Information System (INIS)
For the analysis of the properties of a bound state system one may use in place of the Schroedinger equation the Lippmann-Schwinger (LS) equation for the wave function or the LS equation for the reactance operator. Use of the LS equation for the reactance operator constrains the solution to have correct asymptotic behaviour, so this approach would appear to be desirable when the bound state wave function is to be used to calculate particle transfer form factors. The Schroedinger equation based N-level analysis of the s-wave bound states of a square well is compared to the ones based on the LS equation. It is found that the LS equation methods work better than the Schroedinger equation method. The method that uses the LS equation for the wave function gives the best results for the wave functions while the method that uses the LS equation for the reactance operator gives the best results for the binding energies. The accuracy of the reactance operator based method is remarkably insensitive to changes in the oscillator constant used for the harmonic oscillator function basis set. It is also remarkably insensitive to the number of nodes in the bound state wave function. (Auth.)
Noskievičová, Darja
2009-01-01
The paper deals with the statistical analysis of the selected parameter of the blast furnace process. It was proved that analyzed measurements have been autocorrelated. ARIMA control chart was selected for their analysis as a very useful statistical process control (SPC) method. At first the methodology for control limits setting in ARIMA control charts considering the time series outlier analysis as an integral part of the ARIMA model building was designed. Then this proposal was...
D. Noskievičová
2009-01-01
The paper deals with the statistical analysis of the selected parameter of the blast furnace process. It was proved that analyzed measurements have been autocorrelated. ARIMA control chart was selected for their analysis as a very useful statistical process control (SPC) method. At first the methodology for control limits setting in ARIMA control charts considering the time series outlier analysis as an integral part of the ARIMA model building was designed. Then this proposal was applied to ...
Kurmyshev, Evguenii; González-Silva, Ricardo A
2011-01-01
Bounded confidence models of opinion dynamics have been actively studied in recent years, in particular, opinion formation and extremism propagation along with other aspects of social dynamics. In this work, after an analysis of limitations of the Deffuant-Weisbuch (DW) bounded confidence, relative agreement model, we propose the Mixed model that takes into account two psychological types of individuals. Concord agents (C-agents) are friendly people; they interact in a way that their opinions get closer always. Agents of the other psychological type show partial antagonism in their interaction (PA-agents). Opinion dynamics in heterogeneous social groups, consisting of agents of the two types, was studied on different social networks. Limit cases of the mixed model, pure C- and PA-societies, were also studied. We found that group opinion formation is, qualitatively, almost independent of the topology of networks used in this work. Opinion fragmentation, polarization and consensus are observed in the mixed mode...
Soil texture and climatc conditions for biocrust growth limitation: a meta analysis
Fischer, Thomas; Subbotina, Mariia
2015-04-01
clay content and with study site as a random effect. (III) Threshold values of texture and climatc effects were identified using a regression tree. Three mean annual temperature classes for texture dependent BSC growth limitation were identified: (1) growth on coarser soils), (2) 9-19 °C, where texture did have no influence on relative crust biomass, and (3) >19 °C at soils with 17% silt and clay. Because biocrust development is limited under certain climatic and soil texture conditions, it is suggested to consider soil texture for biocrust rehabilitation purposes and in biogeochemical modeling of cryptogamic ground covers. References Belnap, J. & Eldridge, D. 2001. Disturbance and Recovery of Biological Soil Crusts. In: Belnap, J. & Lange, O. (eds.) Biological Soil Crusts: Structure, Function, and Management, Springer, Berlin. Belnap, J. 2001. Biological Soil Crusts and Wind Erosion. In: Belnap, J. & Lange, O. (eds.) Fischer, T., Subbotina, M. 2014. Climatic and soil texture threshold values for cryptogamic cover development: a meta analysis. Biologia 69/11:1520-1530,
Muhammad Abi Sofian Abdul Halim; Hasyaniza Yahya; Syahrul Hezrin Mahmud; Fatimah Zainab
2011-01-01
This study will determine the level of satisfaction among Terengganu private limited companies towards the concept of corporate entrepreneurship, in a context of; corporate venturing, strategic renewal, and internalization. The study was based on a survey carried out from the questionnaire that is administered involving 105 private limited companies which are operated their business in Terengganu. By using the descriptive analysis on the level of satisfaction among the Terengganu private limi...
Processes regulating progressive nitrogen limitation under elevated carbon dioxide: a meta-analysis
Liang, Junyi; Qi, Xuan; Souza, Lara; Luo, Yiqi
2016-05-01
The nitrogen (N) cycle has the potential to regulate climate change through its influence on carbon (C) sequestration. Although extensive research has explored whether or not progressive N limitation (PNL) occurs under CO2 enrichment, a comprehensive assessment of the processes that regulate PNL is still lacking. Here, we quantitatively synthesized the responses of all major processes and pools in the terrestrial N cycle with meta-analysis of CO2 experimental data available in the literature. The results showed that CO2 enrichment significantly increased N sequestration in the plant and litter pools but not in the soil pool, partially supporting one of the basic assumptions in the PNL hypothesis that elevated CO2 results in more N sequestered in organic pools. However, CO2 enrichment significantly increased the N influx via biological N fixation and the loss via N2O emission, but decreased the N efflux via leaching. In addition, no general diminished CO2 fertilization effect on plant growth was observed over time up to the longest experiment of 13 years. Overall, our analyses suggest that the extra N supply by the increased biological N fixation and decreased leaching may potentially alleviate PNL under elevated CO2 conditions in spite of the increases in plant N sequestration and N2O emission. Moreover, our syntheses indicate that CO2 enrichment increases soil ammonium (NH4+) to nitrate (NO3-) ratio. The changed NH4+/NO3- ratio and subsequent biological processes may result in changes in soil microenvironments, above-belowground community structures and associated interactions, which could potentially affect the terrestrial biogeochemical cycles. In addition, our data synthesis suggests that more long-term studies, especially in regions other than temperate ones, are needed for comprehensive assessments of the PNL hypothesis.
Kaur, Mandeep; Sharma, Manoj K; Gupta, Raj K
2015-01-01
The dynamics of the reactions forming compound nuclei using loosely bound projectiles is analysed within the framework of dynamical cluster decay model (DCM) of Gupta and Collaborators. We have analysed different reactions with $^{7}Li$, $^{9}Be$ and $^{7}Be$ as neutron rich and neutron deficient projectiles, respectively, on different targets at the three $E_{lab}$ values, forming compound nuclei within the mass region A$\\sim 30-200$. The contributions of light particles LPs ($A\\le4$) cross sections $\\sigma_{LP}$, energetically favoured intermediate mass fragments IMFs ($5 \\le A_2 \\le 20$) cross sections $\\sigma_{IMF}$ as well as fusion-fission $\\it{ff}$ cross sections $\\sigma_{ff}$ constitute the $\\sigma_{fus}$ (=$\\sigma_{LP}$+$\\sigma_{IMF}$+$\\sigma_{ff}$) for these reactions. The contribution of the emitted LPs, IMFs and ff fragments is added for all the angular momentum upto the $\\ell_{max}$ value, for the resepctive reactions. Interestingly, we find that the $\\Delta R^{emp}$, the only parameter of model ...
Asymptotic properties of bound states in coupled quantum wave guides
Energy Technology Data Exchange (ETDEWEB)
Maglione, Enrico [Dipartimento di Fisica G Galilei, Via F Marzolo 8, Padova (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova (Italy); Centro de Fisica das Interaccoes Fundamentais (CFIF), Avenida Rovisco Pais, Lisbon (Portugal); Departamento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Ferreira, LIdia S [Centro de Fisica das Interaccoes Fundamentais (CFIF), Avenida Rovisco Pais, Lisbon (Portugal); Departamento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Cattapan, Giorgio [Dipartimento di Fisica G Galilei, Via F Marzolo 8, Padova (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova (Italy)
2006-02-03
We investigate the motion of bound-state poles in two quantum wave guides laterally coupled through a window. The imaginary momentum ik at the bound-state poles is studied as a function of the size a of the window. Both bound and virtual states appear as a spans the whole range from 0 up to +{infinity}. We are able to find simple scaling laws relating the critical value of the window size at which the nth bound state appears to the number n of bound states, in the limit of large n. A similar relation is also provided for the slope and the second derivative of the pole trajectories in the (k, a) plane. These relations are characterized by an extremely high numerical accuracy. We also evaluate the exact value of the first two derivatives for a = 0.
Energy conditions bounds and their confrontation with supernovae data
Lima, M P; Rebouças, M J
2008-01-01
The energy conditions play an important role in the understanding of several properties of the Universe, including the current accelerating expansion phase and the possible existence of the so-called phantom fields. We show that the integrated bounds provided by the energy conditions on cosmological observables such as the distance modulus $\\mu(z)$ and the lookback time $t_L(z)$ are not sufficient (nor necessary) to ensure the local fulfillment of the energy conditions, making explicit the limitation of these bounds in the confrontation with observational data. We recast the energy conditions as bounds on the deceleration and normalized Hubble parameters, obtaining new bounds which are necessary and sufficient for the local fulfillment of the energy conditions. A statistical confrontation, with $1\\sigma$ confidence level, between our bounds and supernovae data from the gold and combined samples is made for the recent past ($z \\leq 1$). Our analyses indicate the fulfillment of the weak and dominant energy cond...
International Nuclear Information System (INIS)
The 5 MW Massachusetts Institute of Technology Research Reactor (MITR-II) is expected to operate under a new license beginning in 1999. Among the options being considered is an upgrade in the heat removal system to allow operation at 10 MW. The purpose of this study is to predict the Limiting Safety System Settings and Safety Limits for the upgraded reactor (MITR-III). The MITR Multi-Channel Analysis Code was written to analyze the response of the MITR system to a series of anticipated transients in order to determine the Limiting Safety System Settings and Safety Limits under various operating conditions. The MIT Multi-Channel Analysis Code models the primary and secondary systems, with special emphasis placed on analyzing the thermal-hydraulic conditions in the core. The code models each MITR fuel element explicitly in order to predict the behavior of the system during flow instabilities. The results of the code are compared to experimental data from MITR-II and other sources. New definitions are suggested for the Limiting Safety System Settings and Safety Limits. MITR Limit Diagrams are included for three different heat removal system configurations. It is concluded that safe, year-round operating at 10 MW is possible, given that the primary and secondary flow rates are both increased by approximately 40%
Preliminary design analysis of the ALT-II limiter for TEXTOR
International Nuclear Information System (INIS)
Installation of a large toroidal belt pump limiter, Advanced Limiter Test II (ALT-II), on the TEXTOR tokamak at Juelich, FRG is anticipated for early 1986. This paper discusses the preliminary mechanical design and materials considerations undertaken as part of the feasibility study phase for ALT-II
International Nuclear Information System (INIS)
This document presents the generic approach adopted by various organizations for the determination of the public exposure limits values to chemical and radioactive substances and for the determination of limits values of chemical products emissions by some installations. (A.L.B.)
Schmitt, Franz-Josef
2009-01-01
Several approaches were used to proof the assumption that an universal upper bound on the entropy to energy ratio (S/E) exists in bounded systems. In 1981 Jacob D. Bekenstein published his findings that S/E is limited by the effective radius of the system and mentioned various approaches to derive S/E employing quantum statistics or thermodynamics. It can be shown that similar results are obtained considering the energetic difference of longitudinal eigenmodes inside a closed cavity like it was done by Max Planck in 1900 to derive the correct formula for the spectral distribution of the black-body radiation. Considering an information theoretical approach this derivation suggests that the variance of an expectation value is the same like the variance of the probability for measuring this expectation value. Implications of these findings are shortly discussed.
Lower Bounds for Quantum Oblivious Transfer
Chailloux, André; Sikora, Jamie
2010-01-01
Oblivious transfer is a fundamental primitive in cryptography. While perfect information theoretic security is impossible, quantum oblivious transfer protocols can limit the dishonest players' cheating. Finding the optimal security parameters in such protocols is an important open question. In this paper we show that every 1-out-of-2 oblivious transfer protocol allows a dishonest party to cheat with probability bounded below by a constant strictly larger than 1/2. Alice's cheating is defined as her probability of guessing Bob's index, and Bob's cheating is defined as his probability of guessing both input bits of Alice. In our proof, we relate these cheating probabilities to the cheating probabilities of a coin flipping protocol and conclude by using Kitaev's coin flipping lower bound. Then, we present an oblivious transfer protocol with two messages and cheating probabilities at most 3/4. Last, we extend Kitaev's semidefinite programming formulation to more general primitives, where the security is against a...
Probabilistically Bounded Staleness for Practical Partial Quorums
Bailis, Peter; Franklin, Michael J; Hellerstein, Joseph M; Stoica, Ion
2012-01-01
Data store replication results in a fundamental trade-off between operation latency and data consistency. In this paper, we examine this trade-off in the context of quorum-replicated data stores. Under partial, or non-strict quorum replication, a data store waits for responses from a subset of replicas before answering a query, without guaranteeing that read and write replica sets intersect. As deployed in practice, these configurations provide only basic eventual consistency guarantees, with no limit to the recency of data returned. However, anecdotally, partial quorums are often "good enough" for practitioners given their latency benefits. In this work, we explain why partial quorums are regularly acceptable in practice, analyzing both the staleness of data they return and the latency benefits they offer. We introduce Probabilistically Bounded Staleness (PBS) consistency, which provides expected bounds on staleness with respect to both versions and wall clock time. We derive a closed-form solution for versi...
Bounds on bacterial cell growth rates
Landy, Jonathan
2013-01-01
Recent experiments have shown that rod-like bacteria in nutrient-rich media grow in length at an exponential rate. Here, I point out that it is the elongated shape of these bacteria that allows for this behavior. Further, I show that when a bacterium's growth is limited by some nutrient -- taken in by the cell through a diffusion-to-capture process -- its growth is suppressed: In three-dimensional geometries, the length $L$ is bounded by $\\log L \\lesssim t^{1/2}$, while in two dimensions the length is bounded by a power-law form. Fits of experimental growth curves to these predicted, sub-exponential forms could allow for direct measures of quantities relating to cellular metabolic rates.
Combining Alphas via Bounded Regression
Directory of Open Access Journals (Sweden)
Zura Kakushadze
2015-11-01
Full Text Available We give an explicit algorithm and source code for combining alpha streams via bounded regression. In practical applications, typically, there is insufficient history to compute a sample covariance matrix (SCM for a large number of alphas. To compute alpha allocation weights, one then resorts to (weighted regression over SCM principal components. Regression often produces alpha weights with insufficient diversification and/or skewed distribution against, e.g., turnover. This can be rectified by imposing bounds on alpha weights within the regression procedure. Bounded regression can also be applied to stock and other asset portfolio construction. We discuss illustrative examples.
Institute of Scientific and Technical Information of China (English)
Zhi-Hong Tao; Cong-Hua Zhou; Zhong Chen; Li-Fu Wang
2007-01-01
Bounded Model Checking has been recently introduced as an efficient verification method for reactive systems.This technique reduces model checking of linear temporal logic to propositional satisfiability.In this paper we first present how quantified Boolean decision procedures can replace BDDs.We introduce a bounded model checking procedure for temporal logic CTL* which reduces model checking to the satisfiability of quantified Boolean formulas.Our new technique avoids the space blow up of BDDs, and extends the concept of bounded model checking.
Directory of Open Access Journals (Sweden)
Cem KADILAR
2005-01-01
Full Text Available This study includes an econometric analysis of the export demand behaviour by using Turkey's annual data that cover 32 years periods from 1970 to 2002. In the study, the 'bounds test' method of Pesaran et al (2001 was used to investigate the long run relationship between export demand, and its determinants, namely income and relative prices. As a result of this empirical analysis, it was demonstrated that export volume, income and relative prices were cointegrated. The estimated long term elasticities of export demand with respect to income and relative prices are 0.21 and -1.684, respectively. The sum of the elasticities of import and export demand exceeds one (-1.01 i.e., Marshall-Lerner condition holds. These results show that monetary, fiscal and exchange rate policies may be used as substitutive policies to correct unfavourable trade balance.
Identities and exponential bounds for transfer matrices
International Nuclear Information System (INIS)
This paper is about analytic properties of single transfer matrices originating from general block-tridiagonal or banded matrices. Such matrices occur in various applications in physics and numerical analysis. The eigenvalues of the transfer matrix describe localization of eigenstates and are linked to the spectrum of the block tridiagonal matrix by a determinantal identity. If the block tridiagonal matrix is invertible, it is shown that half of the singular values of the transfer matrix have a lower bound exponentially large in the length of the chain, and the other half have an upper bound that is exponentially small. This is a consequence of a theorem by Demko, Moss and Smith on the decay of matrix elements of the inverse of banded matrices. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Lyapunov analysis: from dynamical systems theory to applications’. (paper)
Some general bounds for 1-D scattering
Visser, M
1999-01-01
One-dimensional scattering problems are of wide physical interest and are encountered in many diverse applications. In this article I establish some very general bounds for reflection and transmission coefficients for one-dimensional potential scattering. Equivalently, these results may be phrased as general bounds on the Bogolubov coefficients, or statements about the transfer matrix. A similar analysis can be provided for the parametric change of frequency of a harmonic oscillator. A number of specific examples are discussed---in particular I provide a general proof that sharp step function potentials always scatter more effectively than the corresponding smoothed potentials. The analysis also serves to collect together and unify what would otherwise appear to be quite unrelated results.
REE bound DNA in natural plant
Institute of Scientific and Technical Information of China (English)
王玉琦; 江平; 郭繁清; 张智勇; 孙景信; 许雷; 曹国印
1999-01-01
The binding of rare earth elements (REEs) with nucleic acids in the leaves of fern Dicranopteris dichotoma (DD) has been studied by molecular activation analysis (MAA). The REEs bound DNA (REE-DNA) was obtained from the leaves of DD. The CTAB-based procedure was modified for extraction of total DNA. The purity of DNA was examined by UV spectroscopy. The DNA obtained was separated and determined by agarose gel electrophoresis further. Meanwhile, the contents of eight rare earth elements (La, Ce, Nd, Sm, Eu,Tb, Yb and Lu) in REE-DNA were detected by instrumental neutron activation analysis (INAA). The results showed that REE-DNA with higher purity could be extracted from plant using this method. It was also found that REEs were bound firmly with DNA in the leaves of DD. The molecular weight (MW) of REE-DNA band was about 22 kb in agarose gel electrophoresis.
有限理性对劳动力流动决策的影响分析%An analysis of the influence of bounded rationality on labor flow decision-making
Institute of Scientific and Technical Information of China (English)
袁乐平; 王立软; 李萍
2012-01-01
经典劳动力流动理论以完全理性为假设前提，难以准确分析当前我国存在的“盲流”“回流”等劳动力流动“异象”问题。通过对劳动力流动现状与传统理论之间的冲突进行分析，得出造成劳动力流动异象的原因在于劳动者的有限理性。劳动者的有限理性造成预期成本和收益与实际不符，进而影响劳动力的流动决策，当预期净收益现值与实际净收益现值异号时，劳动力流动“异象”便会发生。% The classical labor flow theory is based on the assumption of perfect rationality, which cannot acutely analyze the heteromorphism problem in present Chinese labor flow such as “unemployed migrant people” and labor backflow. The theory deviates from the reality. Through the analysis of conflict between current situation of labor flow and traditional theory, we conclude that bounded rationality leads to heteromorphism problem. So, we analyze the process of generation of labor flow decision-making from the perspective of bounded rationality. The bounded rationality cause the expected costs and benefits do not match with the actual, which would affect labors’ decision-making for flow. Labor flow heteromorphism occurs when there is an opposite sign between the present value of expected net income and the present value of actual net income.
Energy Technology Data Exchange (ETDEWEB)
HU TA
2007-10-31
This document describes the analysis of the waste evaporation process on the flammability behavior. The evaluation calculates the gas generation rate, time to reach 25% and 100% of the lower flammability limit (LFL), and minimum ventilation rates for the 242-A Evaporator facility during the normal evaporation process and when vacuum is lost. This analysis performs flammability calculations on the waste currently within all 28 double-shell tanks (DST) under various evaporation process conditions to provide a wide spectrum of possible flammable gas behavior. The results of this analysis are used to support flammable gas control decisions and support and upgrade to Documented Safety Analysis for the 242-A Evaporator.
Regret Bounds for Deterministic Gaussian Process Bandits
De Freitas, Nando; Smola, Alex; Zoghi, Masrour
2012-01-01
This paper analyses the problem of Gaussian process (GP) bandits with deterministic observations. The analysis uses a branch and bound algorithm that is related to the UCB algorithm of (Srinivas et al., 2010). For GPs with Gaussian observation noise, with variance strictly greater than zero, (Srinivas et al., 2010) proved that the regret vanishes at the approximate rate of $O(\\frac{1}{\\sqrt{t}})$, where t is the number of observations. To complement their result, we attack the deterministic c...
Wolowski, Marina; Ashman, Tia-Lynn; Freitas, Leandro
2014-01-01
Despite the extensive knowledge of pollen limitation in angiosperms, its assessment within tropical forests is still limited. Especially lacking are large scale comparisons of species within this biome - one that is highly diverse but also becoming increasingly threatened. In fact, many tropical plant species depend upon pollinators for reproduction but evaluation of the impact of this dependence via different levels of pollination specialization has yet to be made at the biome scale. We assessed the occurrence and magnitude of pollen limitation for species in the Brazilian Atlantic forest and tested the association of pollination specialization, breeding system, and life habit with pollination efficiency. We compiled data from studies published between 1985 and 2012. We calculated species' effect size (d) from data on fruit set after hand cross-pollination and natural pollination and conducted standard and phylogenetically independent meta-analysis. Overall pollen limitation was moderate, with magnitude of 0.50, and 95% confidence interval [0.37, 0.62] for 126 species. Pollen limitation was observed in 39% of species. Pollination specialization was the factor that best explained the occurrence of pollen limitation. Specifically, phenotypic and ecological specialists (plants with zygomorphic flowers and pollinated by one species of pollinator, respectively) had higher pollen limitation than generalist plants (actinomorphic flowers and pollination by two or more species). Functional generalists (plants pollinated by three or more functional groups) were not pollen limited. On the other hand, breeding system and life habit were not associated to pollen limitation. Pollen limitation was observed in the Atlantic forest and its magnitude was comparable to that for angiosperms as a whole. The finding that pollination specialization was the strongest predictor of pollen limitation suggests that specialist plants in this biome may be most prone to the reproductive failure
Directory of Open Access Journals (Sweden)
Marina Wolowski
Full Text Available Despite the extensive knowledge of pollen limitation in angiosperms, its assessment within tropical forests is still limited. Especially lacking are large scale comparisons of species within this biome - one that is highly diverse but also becoming increasingly threatened. In fact, many tropical plant species depend upon pollinators for reproduction but evaluation of the impact of this dependence via different levels of pollination specialization has yet to be made at the biome scale. We assessed the occurrence and magnitude of pollen limitation for species in the Brazilian Atlantic forest and tested the association of pollination specialization, breeding system, and life habit with pollination efficiency. We compiled data from studies published between 1985 and 2012. We calculated species' effect size (d from data on fruit set after hand cross-pollination and natural pollination and conducted standard and phylogenetically independent meta-analysis. Overall pollen limitation was moderate, with magnitude of 0.50, and 95% confidence interval [0.37, 0.62] for 126 species. Pollen limitation was observed in 39% of species. Pollination specialization was the factor that best explained the occurrence of pollen limitation. Specifically, phenotypic and ecological specialists (plants with zygomorphic flowers and pollinated by one species of pollinator, respectively had higher pollen limitation than generalist plants (actinomorphic flowers and pollination by two or more species. Functional generalists (plants pollinated by three or more functional groups were not pollen limited. On the other hand, breeding system and life habit were not associated to pollen limitation. Pollen limitation was observed in the Atlantic forest and its magnitude was comparable to that for angiosperms as a whole. The finding that pollination specialization was the strongest predictor of pollen limitation suggests that specialist plants in this biome may be most prone to the
Curvature bounds for configuration spaces
Erbar, Matthias; Huesmann, Martin
2014-01-01
We show that the configuration space over a manifold M inherits many curvature properties of the manifold. For instance, we show that a lower Ricci curvature bound on M implies for the configuration space a lower Ricci curvature bound in the sense of Lott-Sturm-Villani, the Bochner inequality, gradient estimates and Wasserstein contraction. Moreover, we show that the heat flow on the configuration space, or the infinite independent particle process, can be identified as the gradient flow of t...
Entropy bounds for uncollapsed matter
Energy Technology Data Exchange (ETDEWEB)
Abreu, Gabriel; Visser, Matt, E-mail: Gabriel.Abreu@msor.vuw.ac.nz, E-mail: Matt.Visser@msor.vuw.ac.nz [School of Mathematics, Statistics and Operation Research Victoria University of Wellington Wellington (New Zealand)
2011-09-22
In any static spacetime the quasilocal Tolman mass contained within a volume can be reduced to a Gauss-like surface integral involving the flux of a suitably defined generalized surface gravity. By introducing some basic thermodynamics, and invoking the Unruh effect, one can then develop elementary bounds on the quasilocal entropy that are very similar in spirit to the holographic bound, and closely related to entanglement entropy.
Finite Domain Bounds Consistency Revisited
Choi, Chiu Wo; Harvey, Warwick; Lee, Jimmy Ho-Man; Stuckey, Peter J.
2004-01-01
A widely adopted approach to solving constraint satisfaction problems combines systematic tree search with constraint propagation for pruning the search space. Constraint propagation is performed by propagators implementing a certain notion of consistency. Bounds consistency is the method of choice for building propagators for arithmetic constraints and several global constraints in the finite integer domain. However, there has been some confusion in the definition of bounds consistency. In t...
Directory of Open Access Journals (Sweden)
Marjanović Nikola J.
2004-01-01
Full Text Available The limit of detection (LOD and the limit of quantitation (LOQ for 16 individual PAHs from the Environmental Protection Agency (EPA list (naphthalene, acenaphthylene, acenaphtene, fluorene, phenanthrene antrachene, fluoranthene, pyrene, benzo(aanthracene, chrysene benzo(bfluoranthene, benzo(kfluoranthene, benzo(apyrene, dibenzo(a,h anthracene, benzo(g,h,iperylene and indeno(1,2,3-cdpyrene were determined by Gas Chromatography – Mass Spectrometry (GC-MS. Determination was performed by SCAN (digital linear scanning and SIM (selected ion monitoring techniques preceded by the optimization of the experimental factors. The limit of detection obtained by the SCAN technique was in the range of 0.179 – 15.236 ng, and the quantitation limit in the range of 1.017 – 50.788 ng. SIM technique enabled LOD and LOQ in the range of 0.036 – 13.886 pg and 0.119 – 46.287 pg respectively.
New Bounds on the Signed Total Domination Number of Graphs
Moghaddam Seyyed Mehdi Hosseini; Mojdeh Doost Ali; Samadi Babak; Volkmann Lutz
2016-01-01
In this paper, we study the signed total domination number in graphs and present new sharp lower and upper bounds for this parameter. For example by making use of the classic theorem of Turán [8], we present a sharp lower bound on Kr+1-free graphs for r ≥ 2. Applying the concept of total limited packing we bound the signed total domination number of G with δ(G) ≥ 3 from above by . Also, we prove that γst(T) ≤ n − 2(s − s′) for any tree T of order n, with s support vertices and s′ support vert...
International Nuclear Information System (INIS)
Highlights: ► We suggested the transformer type SFCL with two triggering current levels. ► The short-circuit tests for the suggested SFCL was executed. ► The fault angle as the fault conditions to verify its operation was selected. ► The usefulness of the suggested SFCL was confirmed through the short-circuit test. -- Abstract: In this paper, the transformer type superconducting fault current limiter (SFCL) with two triggering current levels was suggested and its current limiting characteristics were analyzed. The structure of the suggested transformer type SFCL with two triggering current levels largely consists of two parts. One is the transformer with two magnetically coupled coils, which correspond to the primary winding and the secondary one connected with one high-TC superconducting (HTSC) element. The other is third coil, or, another secondary winding with one HTSC element, which is wound on the same iron core together with two coils. This suggested transformer type SFCL can limit the fault current by generating its limiting impedance with two different amplitudes, which are dependent on the initial amplitude of the fault current in case of the fault occurrence. To confirm the usefulness of the proposed SFCL, the current limiting tests of the SFCL according to the fault angle, one of the effective fault conditions to affect the amplitude of the initial fault current, were carried out and its effective limiting operations were discussed
Composition and Structural Features of Calcium—Bound and Iron—and Aluminium—Bound Humus in Soils
Institute of Scientific and Technical Information of China (English)
S．U．CHEEMA; XUJIAN－MIN; 等
1994-01-01
Calcium-bound and iron-and aluminium-bound humus extracted from different soils collected from north to south of China were characterized by chemical and spectroscopic methods.Meaningful differences in the composition and structure between them were revealed by 13 C NMR,visible spectroscopy and elemental analysis.Results showed that the contents of carbon,hydrogen and nitrogen were higher in iron-and aluminium-bound humus than in calcium-bound humus while oxygen content in calcium-bound humus was shown to be higher .The calcium-bound humus had higher C/N and O/C ratios than iron-and aluminiumbound humus.The calcium-bound humic acid(HA1) showed higher E4/E6 ratios than iron-and aluminumboud,humic acid(HA2)while iron-and aluminum-bound fulvic acid(FA2) showed higher E4/E6 ratios than calcium-bound fulvic acid(FA1).An inverse relationship between E4/E6 ratios and aromaticity as determined by 13C NMR spectra was observerd for HA and FA from black soil.The 13C NMR spectroscopy revealed that HA2 was more aromatic than HA1.On the other ,FA1 exhibited a higher aromaticity than FA2.
Weakly bound states of polar molecules in bilayers
Fedorov, D V; Zinner, N T; Jensen, A S
2011-01-01
We investigate a system of two polarized molecules in a layered trap. The molecules reside in adjacent layers and interact purely via the dipole-dipole interaction. We determine the properties of the ground state of the system as a function of the dipole moment and polarization angle. A bound state is always present in the system and in the weak binding limit the bound state extends to a very large distance and shows universal behavior.
Upper Bounds on the Neutrino-Nucleon Inelastic Cross Section
Anchordoqui, L A; Katz, S D; Ringwald, A; Tu, H
2004-01-01
Extraterrestrial neutrinos can initiate deeply developing air showers, and those that traverse the atmosphere unscathed may produce cascades in the ice or water. Up to now, no such events have been observed. This can be translated into upper limits on the diffuse neutrino flux. On the other hand, the observation of cosmic rays with primary energies > 10^{10} GeV suggests that there is a guaranteed flux of cosmogenic neutrinos, arising from the decay of charged pions (and their muon daughters) produced in proton interactions with the cosmic microwave background. In this work, armed with these cosmogenic neutrinos and the increased exposure of neutrino telescopes we bring up-to-date model-independent upper bounds on the neutrino-nucleon inelastic cross section. Uncertainties in the cosmogenic neutrino flux are discussed and taken into account in our analysis. The prospects for improving these bounds with the Pierre Auger Observatory are also estimated. The unprecedented statistics to be collected by this experi...
International Nuclear Information System (INIS)
The document is an economic impact analysis prepared in support of the promulgation of effluent limitations guidelines and standards of performance for drilling and production wastes for the offshore oil and gas industry. The report analyzes the economic impact of alternative regulatory options considered for drilling fluids, drill cuttings, produced water, produced sand, and treatment, workover, and completion fluids
Limit load analysis for local wall-thinning steam generator tubes
International Nuclear Information System (INIS)
Steam generator(SG) tubes form approximately 80% of pressure boundary of the reactor primary coolant[1]. During the past 40 years, a large number of operating PWPs have experienced degradation due to local wall-thinning of SG tubes, which was caused by corrosion or squeezing of tubes at support plate or tubesheet intersections or other reasons. This paper introduced the study of experiment and numerical analyses for plastic limit loads of local wall-thinning SG tubes. The effect of the dimension of local wall-thinning on plastic limit load was analyzed. The main contents in this paper were summarized as follows: 1 Experiment equipment which could test not only bursting pressure but also plastic limit load was built. Two kinds of local wall-thinning shapes were respectively made on SG tubes. One kind of local wall-thinning shape was rectangle-like flaw, which was used to simulate local wall-thinning caused by squeezing of tubes at support plate. The other kind of local wall-thinning shape was arc-like flaw, which was used to simulate local wall-thinning caused by corrosion. Different size local wall-thinning SG tubes of these two kinds of shape were test by using the equipment. 2 Regularization method for local wall-thinning defect was provided based on experimental and finite element method. 3 The effect order of local wall-thinning configuration on plastic limit load was studied. It was found that: Except defect thickness, the longitudinal length and circumferential length of SGT defect can also influence the plastic limit load; When the longitudinal length of SGT defect exceeded 6 mm, the effect of longitudinal length on plastic limit load can be ignored; When the circumferential angle of defect exceed 45 degree, the effect of circumferential angle on plastic limit load can be ignored. (authors)
Physical bounds for antenna radiation efficiency
Shahpari, Morteza
2016-01-01
Small volume, reduced conductivity and high frequencies are major imperatives in the design of communications infrastructure. The radiation efficiency $\\eta_r$ impacts on the optimal gain, quality factor, and bandwidth. The current efficiency limit applies to structures confined to a radian sphere $ka$ ($k$ is the wave number, $a$ is the radius). Here we present new absolute limits to $\\eta_r$ for arbitrary antenna shapes based on $k^2S$ where $S$ is the conductor surface area. For an electrical length of $10^{-5}$ our result is four orders of magnitude closer to the analytical solution. The improved bound on $\\eta_r$ is more accurate, more general, and easier to calculate than other limits. It is based on the total surface area of the conductors and provides greatly improved estimations for electrically small radiators at very low frequencies. The work is of great benefit to antenna designers assessing new materials such as conductive polymers.
Limitation of egg production in Calanus finmarchicus in the field: A stoichiometric analysis
Mayor, Daniel J.; Anderson, Thomas R.; Pond, David W.; Irigoien, Xabier
2009-11-01
The egg production of marine copepods correlates with a range of variables, including the availability of organic carbon (C), nitrogen (N) and the polyunsaturated fatty acids (PUFAs) 20:5( n-3) (EPA) and 22:6( n-3) (DHA). However, an understanding of which substrates limit egg production in the natural environment has yet to be reached. The quantities of C, N, EPA and DHA ingested, derived from parental biomass, and invested in eggs by female Calanus finmarchicus during a 5-day incubation experiment were examined using stoichiometric theory to determine which substrate was limiting. The majority of each substrate was derived from parental biomass, and therefore the existing stoichiometric theory is developed to include this route of supply. The females were essentially devoid of lipid reserves, as evidenced by the lack of the storage fatty acids 20:1( n-9) and 22:1( n-11), and carbon limitation was predicted under most of the scenarios examined. Nitrogen limitation was only apparent when carbon and nitrogen utilisation efficiencies were assumed to be high (0.5) and low (0.4) respectively. PUFAs were assumed to be utilised with high efficiency (0.9), and were never predicted to limit production. This work highlights the need for a more detailed understanding of the maintenance requirements that marine copepods have for C, N, EPA, and DHA and hence the efficiencies with these substrates can be utilised for growth.
Review and analysis of discharge limitation practice in the European Community
International Nuclear Information System (INIS)
An important area of application of radiation protection philosophy is that concerning the setting of discharge limits for radioactive effluents from nuclear installations. In the European Community, as elsewhere, the scientific basis for discharge authorization and limitation has undergone an evolution reflecting developments in radiation protection; in particular, the principle of optimization had to be assimilated in the regulatory process, a requirement imposed on Member States of the European Community by virtue of the Euratom Directive on Basic Safety Standards. An outline of past and present authorization procedures and discharge limits is presented, based on written and verbal submissions made to two ad-hoc meetings of experts convened by the Commission of the European Communities for the purposes of comparison and mutual exchange of information and techniques. Additionally, the Commission, responding to recent calls by the European Parliament and environmental groups, pledged to re-examine the value of setting regulatory emission standards for nuclear installations. This re-examination involved the consultation, on basic policy for limiting releases, of the Group of Experts which advises the Commission on radiation protection, in the light of recent advances in this field. Moreover, an investigation was undertaken of the application of national regulatory provisions concerning activity discharges of certain nuclear installations. A critical review is presented here of the methods and their application for fixing discharge limits for radioactive effluents from nuclear installations in Member States of the European Community. The implications of using as the basis for discharge limitation a dose criterion or an emission standard are discussed and conclusions drawn concerning the advisability of adopting uniform emission standards for plants of the same design regardless of differences in environmental characteristics. (author). 8 refs
Energy Technology Data Exchange (ETDEWEB)
Pomraning, Kyle R.; Kim, Young-Mo; Nicora, Carrie D.; Chu, Rosalie K.; Bredeweg, Erin L.; Purvine, Samuel O.; Hu, Dehong; Metz, Thomas O.; Baker, Scott E.
2016-02-25
Background Yarrowia lipolytica is an oleaginous ascomycete yeast that stores lipids in response to limitation of nitrogen. While the enzymatic pathways responsible for neutral lipid accumulation in Y. lipolytica are well characterized, regulation of these pathways has received little attention. We therefore sought to characterize the response to nitrogen limitation at system-wide levels, including the proteome, phosphoproteome and metabolome, to deepen our understanding of how this organism regulates and controls lipid metabolism and to identify targets that may be manipulated to improve lipid yield. Results Using a variety of -omic techniques, we found that ribosome structural genes are down-regulated under nitrogen limitation, during which nitrogen containing compounds (alanine, putrescine, spermidine and urea) are depleted and sugar alcohols and TCA cycle intermediates accumulate (citrate, fumarate and malate). We identified 1,219 novel phosphorylation sites in Y. lipolytica, 133 of which change in their abundance during nitrogen limitation. Regulatory proteins, including kinases and DNA binding proteins, are particularly enriched for phosphorylation. Within lipid synthesis pathways, we found that ATP-citrate lyase, acetyl-CoA carboxylase and lecithin cholesterol acyl transferase are phosphorylated during nitrogen limitation while many of the proteins involved in β-oxidation are down-regulated, suggesting that storage lipid accumulation is due either to increased lipogenesis from excess citrate and regulated by phosphorylation of key enzymes, decreased capacity for β-oxidation, or both. Further, we identified short DNA elements that associate specific transcription factor families with up- and down-regulated genes. Conclusions Integration of metabolome, proteome and phosphoproteome data identifies lipid accumulation in response to nitrogen limitation as a two-fold result of increased production of acetyl-CoA from excess citrate and decreased capacity for β-oxidation.
On the upper limits for dipole anisotropies in cosmic-ray positrons
Berdugo, J; Mana, C; Velasco, M A
2015-01-01
The excess of cosmic-ray positrons in the energy range from 10 GeV to few hundred GeV reported by PAMELA and AMS experiments is not consistent with a pure secondary origin and requires the introduction of a source term. The presence of anisotropies in the positron arrival directions would be a distinctive signature of their origin. Current measurements are consistent with isotropy and limits to a dipole anisotropy have been established. In this note, we review the mathematical basis of this analysis and provide a general bound to the dipole upper limits achievable from a given sample of events. The published experimental limits are confronted with this bound.
On a Generalization of Kingman's Bounds
Liu, Zhen; Nain, Philippe; Towsley, Don
1994-01-01
In this paper we develop a framework for computing upper and lower bounds of an exponential form for a class of single server queueing systems with non-renewal inputs. These bounds generalize Kingman's bounds for queues with renewal inputs.
Lower bounds on fluctuations for internal DLA
Asselah, Amine; Gaudilliere, Alexandre
2011-01-01
We consider internal diffusion limited aggregation in dimension larger than or equal to two. This is a random cluster growth model, where random walks start at the origin of the d-dimensional lattice, one at a time, and stop moving when reaching a site that is not occupied by previous walks. When n random walks are sent from the origin, we establish a lower bound for the inner and outer errors fluctuations of order square root of the logarithm of n. When dimension is larger or equal to three,...
Andreev bound states. Some quasiclassical reflections
International Nuclear Information System (INIS)
We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it
Andreev bound states. Some quasiclassical reflections
Energy Technology Data Exchange (ETDEWEB)
Lin, Y., E-mail: yiriolin@illinois.edu; Leggett, A. J. [University of Illinois at Urhana-Champaign, Dept. of Physics (United States)
2014-12-15
We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it.
Organically bound tritium, OBT: Its true constitution
International Nuclear Information System (INIS)
Full text: Tritium, which is analytically determined to be non-exchangeable bound in tissue solids, is assumed to be bound to carbon. Furthermore, it follows that the biochemical passways by photosynthesis or enzymatic transfer reactions are retarded by the kinetic isotope effect leading to discrimination of tritium in biomolecules. In contrast, the logistic growth analysis of plants discloses a larger intrinsic growth rate of OBT than of OBH, resulting in tritium accumulation in biomolecules. Exchange experiments providing fractionation factors of 1.4 and 2 confirm this accumulation. In summary a larger part of the so called OBT is not carbon bound but consists of tritium positioned in hydrogen bridges of biopolymers which have been occupied during formation of the molecules and which became later inaccessible for exchange (so called buried hydrogens). Furthermore, there are experimental results indicating even rapid exchange during the in vivo state but inhibited in the in vitro state, which is commonly given in bio samples prepared for analysis. (author)
Czech Academy of Sciences Publication Activity Database
Španěl, Patrik; Smith, D.
2009-01-01
Roč. 280, 1-3 (2009), s. 128-135. ISSN 1387-3806 R&D Projects: GA AV ČR IAA400400702 Institutional research plan: CEZ:AV0Z40400503 Keywords : ion-molecule association * adduct ion * SIFT-MS * breath analysis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.117, year: 2009
Cunningham, Charles E.; Rimas, Heather; Mielko, Stephanie; Mapp, Cailin; Cunningham, Lesley; Buchanan, Don; Vaillancourt, Tracy; Chen, Yvonne; Deal, Ken; Marcus, Madalyn
2016-01-01
Prevention programs yield modest reductions in bullying in North American schools. This study explored the perspective of educators regarding factors limiting the impact of these initiatives. Transcripts from nineteen 90-min focus groups with 103 educators were coded thematically. Educators felt that off-site incidents, cyberbullying, and the…
On singular limits arising in the scale analysis of stratified fluid flows
Czech Academy of Sciences Publication Activity Database
Feireisl, Eduard; Klein, R.; Novotný, A.; Zatorska, E.
2016-01-01
Roč. 26, č. 3 (2016), s. 419-443. ISSN 0218-2025 Grant ostatní: European Research Council(XE) MATHEF(320078) Institutional support: RVO:67985840 Keywords : isentropic fluid flow * strong stratification * singular limit * anelastic approximation Subject RIV: BA - General Mathematics Impact factor: 3.094, year: 2014 http://www.worldscientific.com/doi/10.1142/S021820251650007X
ECONOMIC IMPACT ANALYSIS OF EFFLUENT STANDARDS AND LIMITATIONS FOR THE METAL FINISHING INDUSTRY
The U.S. Environmental Protection Agency issued e-fluent guidelines and limitations for the Metal Finishing Industry in June 1983. This report estimates the economic impact of pollution control costs in terms of price changes, effects profitability, potential plant closures, unem...
Analysis of bifurcations of limit cycles with Lyapunov exponents and numerical normal forms
Witte, de V.; Govaerts, W.; Kuznetsov, Yu.A.; Meijer, H.G.E.
2014-01-01
In this paper we focus on the combination of normal form and Lyapunov exponent computations in the numerical study of the three codim 2 bifurcations of limit cycles with dimension of the center manifold equal to 4 or to 5 in generic autonomous ODEs. The normal form formulas are independent of the di
Pareto-Optimal Evaluation of Ultimate Limit States in Offshore Wind Turbine Structural Analysis
Directory of Open Access Journals (Sweden)
Michael Muskulus
2015-12-01
Full Text Available The ultimate capacity of support structures is checked with extreme loads. This is straightforward when the limit state equations depend on a single load component, and it has become common to report maxima for each load component. However, if more than one load component is influential, e.g., both axial force and bending moments, it is not straightforward how to define an extreme load. The combination of univariate maxima can be too conservative, and many different combinations of load components can result in the worst value of the limit state equations. The use of contemporaneous load vectors is typically non-conservative. Therefore, in practice, limit state checks are done for each possible load vector, from each time step of a simulation. This is not feasible when performing reliability assessments and structural optimization, where additional, time-consuming computations are involved for each load vector. We therefore propose to use Pareto-optimal loads, which are a small set of loads that together represent all possible worst case scenarios. Simulations with two reference wind turbines show that this approach can be very useful for jacket structures, whereas the design of monopiles is often governed by the bending moment only. Even in this case, the approach might be useful when approaching the structural limits during optimization.
World Bank
2009-01-01
This private sector opinion is organized in two parts. Part one, published in June 2009, examined the uses and limits of five conventional corporate governance instruments: transparency, independent monitoring, economic alignment, shareholder rights, and financial liability and suggested ways to improve their application. Part two, the essay that follows, recommends how policymakers should ...
Efficiency bounds for nonequilibrium heat engines
International Nuclear Information System (INIS)
We analyze the efficiency of thermal engines (either quantum or classical) working with a single heat reservoir like an atmosphere. The engine first gets an energy intake, which can be done in an arbitrary nonequilibrium way e.g. combustion of fuel. Then the engine performs the work and returns to the initial state. We distinguish two general classes of engines where the working body first equilibrates within itself and then performs the work (ergodic engine) or when it performs the work before equilibrating (non-ergodic engine). We show that in both cases the second law of thermodynamics limits their efficiency. For ergodic engines we find a rigorous upper bound for the efficiency, which is strictly smaller than the equivalent Carnot efficiency. I.e. the Carnot efficiency can be never achieved in single reservoir heat engines. For non-ergodic engines the efficiency can be higher and can exceed the equilibrium Carnot bound. By extending the fundamental thermodynamic relation to nonequilibrium processes, we find a rigorous thermodynamic bound for the efficiency of both ergodic and non-ergodic engines and show that it is given by the relative entropy of the nonequilibrium and initial equilibrium distributions. These results suggest a new general strategy for designing more efficient engines. We illustrate our ideas by using simple examples. -- Highlights: ► Derived efficiency bounds for heat engines working with a single reservoir. ► Analyzed both ergodic and non-ergodic engines. ► Showed that non-ergodic engines can be more efficient. ► Extended fundamental thermodynamic relation to arbitrary nonequilibrium processes
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
A new performance analysis method of Optical Code Division Multiple Access (OCDMA) systems with an optical hard-limiter is studied. The bit error probability of the OCDMA system is derived, and the numerical results of the system with and without an ideal optical hard-limiter are analyzed respectively. The results show that although the derived expression is different from the one derived by J A Salehi［1］, the numerical results are the same as those analyzed by J A Salehi, and the numerical result can be easily achieved in this expression.
Bound-preserving discontinuous Galerkin methods for relativistic hydrodynamics
Qin, Tong; Shu, Chi-Wang; Yang, Yang
2016-06-01
In this paper, we develop a discontinuous Galerkin (DG) method to solve the ideal special relativistic hydrodynamics (RHD) and design a bound-preserving (BP) limiter for this scheme by extending the idea in X. Zhang and C.-W. Shu, (2010) [56]. For RHD, the density and pressure are positive and the velocity is bounded by the speed of light. One difficulty in numerically solving the RHD in its conservative form is that the failure of preserving these physical bounds will result in ill-posedness of the problem and blowup of the code, especially in extreme relativistic cases. The standard way in dealing with this difficulty is to add extra numerical dissipation, while in doing so there is no guarantee of maintaining the high order of accuracy. Our BP limiter has the following features. It can theoretically guarantee to preserve the physical bounds for the numerical solution and maintain its designed high order accuracy. The limiter is local to the cell and hence is very easy to implement. Moreover, it renders L1-stability to the numerical scheme. Numerical experiments are performed to demonstrate the good performance of this bound-preserving DG scheme. Even though we only discuss the BP limiter for DG schemes, it can be applied to high order finite volume schemes, such as weighted essentially non-oscillatory (WENO) finite volume schemes as well.
Faassen, Elisabeth J.; Antoniou, Maria G.; Wendy Beekman-Lukassen; Lucie Blahova; Ekaterina Chernova; Christophoros Christophoridis; Audrey Combes; Christine Edwards; Jutta Fastner; Joop Harmsen; Anastasia Hiskia; Ilag, Leopold L.; Triantafyllos Kaloudis; Srdjan Lopicic; Miquel Lürling
2016-01-01
Exposure to beta-N-methylamino-l-alanine (BMAA) might be linked to the incidence of amyotrophic lateral sclerosis, Alzheimer's disease and Parkinson's disease. Analytical chemistry plays a crucial role in determining human BMAA exposure and the associated health risk, but the performance of various analytical methods currently employed is rarely compared. A CYANOCOST initiated workshop was organized aimed at training scientists in BMAA analysis, creating mutual understanding and paving the wa...
Czech Academy of Sciences Publication Activity Database
Agakishiev, G.; Arnold, O.; Belver, D.; Belyaev, A.; Krása, Antonín; Křížek, Filip; Kugler, Andrej; Sobolev, Yuri, G.; Tlustý, Pavel; Wagner, Vladimír
2015-01-01
Roč. 742, MAR (2015), s. 242-248. ISSN 0370-2693 R&D Projects: GA MŠk LG12007; GA ČR GA13-06759S Institutional support: RVO:61389005 Keywords : kaonic nuclei * anti-kaon-nucleon physics * ppK(-) * low energy * QCD * partial wave analysis Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 6.131, year: 2014
Improved Range Searching Lower Bounds
DEFF Research Database (Denmark)
Larsen, Kasper Green; Nguyen, Huy L.
2012-01-01
range reporting problem. In approximate simplex range reporting, points that lie within a distance of ε ⋅ Diam(s) from the border of a query simplex s, are free to be included or excluded from the output, where ε ≥ 0 is an input parameter to the range searching problem. We prove our lower bounds......Table of Contents -------------------------------------------------------------------------------- In this paper we present a number of improved lower bounds for range searching in the pointer machine and the group model. In the pointer machine, we prove lower bounds for the approximate simplex...... by constructing a hard input set and query set, and then invoking Chazelle and Rosenberg's [CGTA'96] general theorem on the complexity of navigation in the pointer machine. For the group model, we show that input sets and query sets that are hard for range reporting in the pointer machine (i.e. by Chazelle...
Simulation bounds for system availability
International Nuclear Information System (INIS)
System availability is a dominant factor in the practicality of nuclear power electrical generating plants. A proposed model for obtaining either lower bounds or interval estimates on availability uses observed data on ''n'' failure-to-repair cycles of the system to estimate the parameters in the time-to-failure and time-to-repair models. These estimates are then used in simulating failure/repair cycles of the system. The availability estimate is obtained for each of 5000 samples of ''n'' failure/repair cycles to form a distribution of estimates. Specific percentile points of those simulated distributions are selected as lower simulation bounds or simulation interval bounds for the system availability. The method is illustrated with operational data from two nuclear plants for which an exponential time-to-failure and a lognormal time-to-repair are assumed
Analysis of the H-mode density limit in the ASDEX upgrade tokamak using bolometry
Energy Technology Data Exchange (ETDEWEB)
Bernert, Matthias
2013-10-23
The high confinement mode (H-mode) is the operational scenario foreseen for ITER, DEMO and future fusion power plants. At high densities, which are favourable in order to maximize the fusion power, a back transition from the H-mode to the low confinement mode (L-mode) is observed. This H-mode density limit (HDL) occurs at densities on the order of, but below, the Greenwald density. In this thesis, the HDL is revisited in the fully tungsten walled ASDEX Upgrade tokamak (AUG). In AUG discharges, four distinct operational phases were identified in the approach towards the HDL. First, there is a stable H-mode, where the plasma density increases at steady confinement, followed by a degrading H-mode, where the core electron density is fixed and the confinement, expressed as the energy confinement time, reduces. In the third phase, the breakdown of the H-mode and transition to the L-mode, the overall electron density is fixed and the confinement decreases further, leading, finally, to an L-mode, where the density increases again at a steady confinement at typical L-mode values until the disruptive Greenwald limit is reached. These four phases are reproducible, quasi-stable plasma regimes and provide a framework in which the HDL can be further analysed. Radiation losses and several other mechanisms, that were proposed as explanations for the HDL, are ruled out for the current set of AUG experiments with tungsten walls. In addition, a threshold of the radial electric field or of the power flux into the divertor appears to be responsible for the final transition back to L-mode, however, it does not determine the onset of the HDL. The observation of the four phases is explained by the combination of two mechanisms: a fueling limit due to an outward shift of the ionization profile and an additional energy loss channel, which decreases the confinement. The latter is most likely created by an increased radial convective transport at the edge of the plasma. It is shown that the
Analysis of background components in Ge-spectrometry and their influence on detection limits
Energy Technology Data Exchange (ETDEWEB)
Heusser, G. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)
1997-03-01
In low radioactivity measurements the system own background of the spectrometer is, besides the counting efficiency, the limiting factor for the achievable sensitivity. Since the latter is mostly fixed, background reduction is the only way to gain sensitivity, although it is inversely proportional only to the square root of the background rate but directly proportional to the counting efficiency. A thorough understanding of the background sources and their quantitative contribution helps to choose the most adequate suppression method in order to reach a certain required level of detection limit. For Ge-spectrometry the background can be reduced by 5 to 6 orders of magnitude compared to the unshielded case applying state-of-the-art techniques. This reduction factor holds for the continuous background spectrum as well as for the line background as demonstrated for a Ge detector of the Heidelberg-Moscow double beta decay experiment. (orig./DG)
Guermond, Jean-Luc
2010-01-01
We revisit some results from M. L. Adams [Nu cl. Sci. Engrg., 137 (2001), pp. 298- 333]. Using functional analytic tools we prove that a necessary and sufficient condition for the standard upwind discontinuous Galerkin approximation to converge to the correct limit solution in the diffusive regime is that the approximation space contains a linear space of continuous functions, and the restrictions of the functions of this space to each mesh cell contain the linear polynomials. Furthermore, the discrete diffusion limit converges in the Sobolev space H1 to the continuous one if the boundary data is isotropic. With anisotropic boundary data, a boundary layer occurs, and convergence holds in the broken Sobolev space H with s < 1/2 only © 2010 Society for Industrial and Applied Mathematics.
Analysis of the H-mode density limit in the ASDEX upgrade tokamak using bolometry
International Nuclear Information System (INIS)
The high confinement mode (H-mode) is the operational scenario foreseen for ITER, DEMO and future fusion power plants. At high densities, which are favourable in order to maximize the fusion power, a back transition from the H-mode to the low confinement mode (L-mode) is observed. This H-mode density limit (HDL) occurs at densities on the order of, but below, the Greenwald density. In this thesis, the HDL is revisited in the fully tungsten walled ASDEX Upgrade tokamak (AUG). In AUG discharges, four distinct operational phases were identified in the approach towards the HDL. First, there is a stable H-mode, where the plasma density increases at steady confinement, followed by a degrading H-mode, where the core electron density is fixed and the confinement, expressed as the energy confinement time, reduces. In the third phase, the breakdown of the H-mode and transition to the L-mode, the overall electron density is fixed and the confinement decreases further, leading, finally, to an L-mode, where the density increases again at a steady confinement at typical L-mode values until the disruptive Greenwald limit is reached. These four phases are reproducible, quasi-stable plasma regimes and provide a framework in which the HDL can be further analysed. Radiation losses and several other mechanisms, that were proposed as explanations for the HDL, are ruled out for the current set of AUG experiments with tungsten walls. In addition, a threshold of the radial electric field or of the power flux into the divertor appears to be responsible for the final transition back to L-mode, however, it does not determine the onset of the HDL. The observation of the four phases is explained by the combination of two mechanisms: a fueling limit due to an outward shift of the ionization profile and an additional energy loss channel, which decreases the confinement. The latter is most likely created by an increased radial convective transport at the edge of the plasma. It is shown that the
The costs of limiting fossil-fuel CO2 emissions: A survey and analysis
International Nuclear Information System (INIS)
In the late 1980s, interest flourished in the issue of global climate change. Many studies focused on the options for limiting anthropogenic emissions of greenhouse-related gases and managing the consequences of global warming and climate change. Making appropriate policy choices requires information on both the costs and benefits, as the occur over time, of policy interventions, and in increasing number of studies have sought to quantify the costs especially of limiting CO2 emissions, as the dominant anthropogenic source. Such analyses now form an important part of overall policy assessments and influence international negotiations on policy responses. However, these studies are not well understood. In this paper the authors seek to analyze the literature on the costs of CO2 abatement. 152 ref
Systematic single-cell analysis of Pichia pastoris reveals secretory capacity limits productivity.
Directory of Open Access Journals (Sweden)
Kerry Routenberg Love
Full Text Available Biopharmaceuticals represent the fastest growing sector of the global pharmaceutical industry. Cost-efficient production of these biologic drugs requires a robust host organism for generating high titers of protein during fermentation. Understanding key cellular processes that limit protein production and secretion is, therefore, essential for rational strain engineering. Here, with single-cell resolution, we systematically analysed the productivity of a series of Pichia pastoris strains that produce different proteins both constitutively and inducibly. We characterized each strain by qPCR, RT-qPCR, microengraving, and imaging cytometry. We then developed a simple mathematical model describing the flux of folded protein through the ER. This combination of single-cell measurements and computational modelling shows that protein trafficking through the secretory machinery is often the rate-limiting step in single-cell production, and strategies to enhance the overall capacity of protein secretion within hosts for the production of heterologous proteins may improve productivity.
International Nuclear Information System (INIS)
Inductive fault current limiters of magnetic shielding type can be described in terms of the excursion in the plane defined by flux linked with primary and line current, and this methodology has been previously applied to single-phase devices. Practical applications, however, require three-phase limiters, which, for the sake of compactness, may be built by three legged cores, instead of three single phase units. This has the advantage of using well established methods of power transformers industry, but the performance of the devices depends on the type of fault, e.g. phase to ground or phase to phase. For instance, in a three legged core, a phase to ground fault affects healthy phases, and these are the most frequent faults in distribution grids, where such systems are envisaged. The effects of asymmetric faults are analysed in this paper, by means of measured excursions in the linked flux-current plane.
Ferreira, R.; Pina, J. M.; Vilhena, N.; Arsénio, P.; Pronto, A. G.; Martins, J.
2014-05-01
Inductive fault current limiters of magnetic shielding type can be described in terms of the excursion in the plane defined by flux linked with primary and line current, and this methodology has been previously applied to single-phase devices. Practical applications, however, require three-phase limiters, which, for the sake of compactness, may be built by three legged cores, instead of three single phase units. This has the advantage of using well established methods of power transformers industry, but the performance of the devices depends on the type of fault, e.g. phase to ground or phase to phase. For instance, in a three legged core, a phase to ground fault affects healthy phases, and these are the most frequent faults in distribution grids, where such systems are envisaged. The effects of asymmetric faults are analysed in this paper, by means of measured excursions in the linked flux-current plane.
International Nuclear Information System (INIS)
During the last years more and more reports about film replacement techniques are published using different ways to prove the required and obtained image quality. The motivation is usually cost reduction due to shorter exposure times and lower storage costs, smaller space requirements and elimination of chemical processing inclusive associated waste handling and disposal. New calibration and measurement procedures have been developed to explore the upper limits of image quality (signal-to-noise ratio SNR) achievable with the new digital detector arrays (DDAs). The developed algorithms realize a new high contrast sensitivity technique, which allows distinguishing wall thickness changes down to 1/1000 of the penetrated material thickness. Standard film radiography using the best NDT film systems (class ''C1'' according to EN 584-1) achieves a wall thickness contrast which is limited to 1/100 of the penetrated material thickness. The achieved image qualities of film and DDAs are compared on the basis of a test weldment. (orig.)
When to start antiretroviral therapy in resource-limited settings: a human rights analysis
Calmy Alexandra; Ford Nathan; Hurst Samia
2010-01-01
Abstract Background Recent evidence from developed and developing countries shows clear clinical and public health benefit to starting antiretroviral therapy (ART) earlier. While discussions about when to start ART have often focused on the clinical risks and benefits, the main issue is one of fair limit-setting. We applied a human rights framework to assess a policy of early treatment initiation according to the following criteria: public-health purpose; likely effectiveness; specificity; hu...
ABED-MERAIM, Farid; BALAN, Tudor; ALTMEYER, Guillaume
2014-01-01
The prediction of forming limit diagrams (FLDs) is of significant interest to the sheet metal forming industry. Although a large variety of plastic instability criteria have been developed during the previous decades, there is still a lack of comparison of their respective theoretical bases. The aim of this paper is to present the theoretical formulations of a representative selection of diffuse necking and strain localization criteria based on the maximum force principle, the Marciniak-Kuczy...
Ribeiro, Nuno A; Jorge, Susana M.
2013-01-01
In order to keep local public finances balanced, in many countries, measures restraining and controlling debt have been implemented. In Portugal such concerns have been considered too. Accordingly, several legal diplomas have been passed, namely local finances laws, defining rules, mainly related to limits and restrictions to interest, repayments of borrowings, as well as net debt level. Therefore, it should be expected that these legal restrictions would contribute to reduce municipal deb...
Refining Castelnuovo-Halphen bounds
Di Gennaro, Vincenzo
2011-01-01
Fix integers $r,d,s,\\pi$ with $r\\geq 4$, $d\\gg s$, $r-1\\leq s \\leq 2r-4$, and $\\pi\\geq 0$. Refining classical results for the genus of a projective curve, we exhibit a sharp upper bound for the arithmetic genus $p_a(C)$ of an integral projective curve $C\\subset {\\mathbb{P}^r}$ of degree $d$, assuming that $C$ is not contained in any surface of degree $ \\pi$. Next we discuss other types of bound for $p_a(C)$, involving conditions on the entire Hilbert polynomial of the integral surfaces on which $C$ may lie.
Bounding solutions of Pfaff equations
Esteves, E.; Kleiman, S
2003-01-01
Let \\omega be a Pfaff system of differential forms on a projective space. Let S be its singular locus, and Y a solution of \\omega=0. We prove Y\\cap S is of codimension at most 1 in Y, just as Jouanolou suspected; he proved this result assuming \\omega is completely integrable, and asked if the integrability is, in fact, needed. Furthermore, we prove a lower bound on the Castelnuovo--Mumford regularity of Y\\cap S. As in two related articles, we derive upper bounds on numerical invariants of Y, ...
Bound orbits and gravitational theory
Dadhich, Naresh; Ghosh, Sushant G.(School of Mathematical Sciences, University of KwaZulu-Natal, Westville, 4000, Durban, South Africa); Jhingan, Sanjay
2013-01-01
It can be easily shown that bound orbits around a static source can exist only in 4 dimension and in none else for any long range force. This is so not only for Maxwell's electromagnetic and Newton's gravity but also for Einstein's gravitation theory. In contrast to Maxwell's electrodynamics and Newton's gravity, GR has a natural higher dimensional generalization in Lovelock gravity which remarkably admits bound orbits around a static black hole in all even d=2N+2 dimensions where $N$ is degr...
Lying for the Greater Good: Bounded Rationality in a Team
Directory of Open Access Journals (Sweden)
Oktay Sürücü
2014-10-01
Full Text Available This paper is concerned with the interaction between fully and boundedly rational agents in situations where their interests are perfectly aligned. The cognitive limitations of the boundedly rational agent do not allow him to fully understand the market conditions and lead him to take non-optimal decisions in some situations. Using categorization to model bounded rationality, we show that the fully rational agent can nudge, i.e., he can manipulate the information he sends and decrease the expected loss caused by the boundedly rational agent. Assuming different types for the boundedly rational agent, who differ only in the categories used, we show that the fully rational agent may learn the type of the boundedly rational agent along their interaction. Using this additional information, the outcome can be improved and the amount of manipulated information can be decreased. Furthermore, as the length of the interaction increases the probability that the fully rational agent learns the type of the boundedly rational agent grows
Quasi Steady-State Model for Power System Stability: Limitations, Analysis and a Remedy
Wang, XiaoZhe; Chiang, Hsiao-Dong
2014-01-01
The quasi steady-state (QSS) model tries to reach a good compromise between accuracy and efficiency in long-term stability analysis. However, the QSS model is unable to provide correct approximations and stability assessment for the long-term stability model consistently. In this paper, some numerical examples in which the QSS model was stable while the long-term stability model underwent instabilities are presented with analysis in nonlinear system framework. At the same time, a hybrid model...
International Nuclear Information System (INIS)
A program that permits the a priori calculation of detection limits in monoelemental matrices, adapted to instrumental neutron activation analysis using a SLOWPOKE II reactor, is described. A simplified model of the gamma spectra is proposed. Products of (n,p) and (n,α) reactions induced by the fast components of the neutron flux that accompanies the thermal flux at the level of internal irradiation sites in the reactor have been included in the list of interfering radionuclides. The program calculates in a systematic way the detection limits of 66 elements in an equal number of matrices using 153 intermediary radionuclides. Experimental checks carried out with silicon (for short lifetimes) and aluminum and magnesium (for intermediate lifetimes) show satisfactory agreement with the calculations. These results show in particular the importance of the contribution of the (n,p) and (n,α) reactions in the a priori evaluation of detection limits with a SLOWPOKE type reactor
New Bounds on the Signed Total Domination Number of Graphs
Directory of Open Access Journals (Sweden)
Moghaddam Seyyed Mehdi Hosseini
2016-05-01
Full Text Available In this paper, we study the signed total domination number in graphs and present new sharp lower and upper bounds for this parameter. For example by making use of the classic theorem of Turán [8], we present a sharp lower bound on Kr+1-free graphs for r ≥ 2. Applying the concept of total limited packing we bound the signed total domination number of G with δ(G ≥ 3 from above by . Also, we prove that γst(T ≤ n − 2(s − s′ for any tree T of order n, with s support vertices and s′ support vertices of degree two. Moreover, we characterize all trees attaining this bound.
Surface analysis of TiC limiter exposed in JIPP T-II stellarator/tokamak hybrid device
International Nuclear Information System (INIS)
The surfaces of TiC (20 μm) coated limiters were investigated after four-month plasma exposure with tokamak and stellarator type discharges in JIPP T-II. Three types of surface damage were observed as 1) a large melted spot having many macrocracks, 2) a large exfoliated surface of the coating and 3) a color changed region without exfoliation of the coating. The position of damages observed on the ring limiters and the rail limiter revealed that the damages of 2) and 3) were associated with the asymmetric cross-sectional shape of the stellarator type plasma. The quantitative AES analysis was performed for identification of surface impurities (Si,P,C, etc.) transported from the plasma and for depth composition analysis of the limiters. It was found that C atoms were depleted from the subsurface region and 0 atoms accumulated to produce a thick Ti-oxide layer (1500 A). The thickness of the oxide and the amount of retained Fe atoms in the subsurface region were also found to be associated with the asymmetric shape of stellarator type plasma. (orig.)
Nonlinear Instabilities in Shock-Bounded Slabs
Vishniac, E T
1993-01-01
(substantial changes to section 3.2, otherwise minor) We present an analysis of the hydrodynamic stability of a cold slab bounded by two accretion shocks. Previous numerical work has shown that when the Mach number of the shock is large the slab is unstable. Here we show that to linear order both the bending and breathing modes of such a slab are stable. However, nonlinear effects will tend to soften the restoring forces for bending modes, and when the slab displacement is comparable to its thickness this gives rise to a nonlinear instability. The growth rate of the instability, above this threshold but for small bending angles, is $\\sim c_sk (k\\eta)^{1/2}$, where $\\eta$ is the slab displacement. When the bending angle is large the slab will contain a local vorticity comparable to $c_s/L$, where $L$ is the slab thickness. We discuss the implications of this work for gravitational instabilities of slabs. Finally, we examine the cases of a decelerating slab bounded by a single shock and a stationary slab bounde...
Energy Technology Data Exchange (ETDEWEB)
Jardim, J.L.; Macedo, N.J.; Santo, S.E.; Praca, A.S. [FURNAS Centrais Eletricas S.A., Rio de Janeiro, RJ (Brazil)
1994-12-31
The effect of over excitation limiters on power system voltage stability is presented in this paper. A linear analysis based on system eigenvalues for various operating conditions shows that voltage collapse is essentially a dynamic phenomenon. Time simulations using digital tools and real-time simulator were performed to verify lin ear results and study large disturbances. A control system designed to keep system in secure region is proposed. (author) 3 refs., 9 figs.
Czech Academy of Sciences Publication Activity Database
Čermák, M.; Haslinger, Jaroslav; Kozubek, T.; Sysala, Stanislav
2015-01-01
Roč. 95, č. 12 (2015), s. 1348-1371. ISSN 0044-2267 R&D Projects: GA ČR GA13-18652S Institutional support: RVO:68145535 Keywords : frictionless contact * alternating direction method of multipliers * limit load analysis * elastic-perfect analplasticity Subject RIV: BA - General Mathematics Impact factor: 1.162, year: 2014 http://onlinelibrary.wiley.com/doi/10.1002/zamm.201400069/epdf
Simone Rupp; Andreas Off; Hendrik Seitz-Moskaliuk; James, Timothy M.; Telle, Helmut H.
2015-01-01
Raman spectroscopy for low-pressure or trace gas analysis is rather challenging, in particular in process control applications requiring trace detection and real-time response; in general, enhancement techniques are required. One possible enhancement approach which enjoys increasing popularity makes use of an internally-reflective capillary as the gas cell. However, in the majority of cases, such capillary systems were often limited in their achievable sensitivity by a significant fluorescenc...
Analysis of sputtering from a TiC coated test limiter in the Tokamak de Varennes
International Nuclear Information System (INIS)
An assembly which allows insertion of a test-limiter into a hot plasma has been developed. In addition to its usefulness in the study of various materials, it is also well adapted for measuring the properties of the edge plasma. Measurements of sputtering and power deposition can be used to determine unique values for the plasma density and temperature. In addition, the fluctuations of the radiation from the edge have shown very regular 'sawteeth', which we have correlated with other diagnostics. These display a surprising phase inversion near the edge
On a strong field limit analysis and gravitational lensing of an Ellis wormhole
Tsukamoto, Naoki
2016-01-01
Observations of gravitational lenses in strong gravitational fields will give us a clue for understanding dark compact objects. In this paper, we suggest two small revisions of a method to obtain a deflection angle in a strong field limit provided by Bozza [Phys. Rev. D 66, 103001 (2002)]. First, we correct the order of an error term of the deflection angle. Second, we revise the method to apply to ultrastatic spacetimes. Using the improved method, we consider gravitational lensing by an Ellis wormhole which is an ultrastatic wormhole of the Morris-Thorne class.
Outage analysis of interference-limited systems using STBC with co-channel MIMO interferers
Institute of Scientific and Technical Information of China (English)
Yongzhao LI; Leonard J.CIMINI,JR.; Nageen HIMAYAT
2009-01-01
The performance of Space-Time Block Coding (STBC) with co-channel MIMO interference is investigated.For an interference-limited environment, the closed-form ex-pressions for the probability density functions of the signal-to-interference ratio are derived and applied to analyze the outage probability with three typical types of co-channel MIMO interferers: STBC, open-loop spatial multiplexing and closed-loop spatial multiplexing. Both theoretical anal-yses and simulation results show that the performance of STBC is independent of the MIMO modes used in the in-terfering links.
The Method of Economic Analysis of International Law: What are its Limits?
DEFF Research Database (Denmark)
Tang, Yi Shin
2016-01-01
The article discusses the most recent developments regarding the use of the so-called “economic analysis” approaches to international law. It reviews the main features of this methodology and its potential contribution for promoting critical scholarship in international legal studies, particularly...... in specific contemporary issues such as international security, trade and environment. The article also points out the most important limitations of this approach, which mainly derive from a misunderstanding of the assumptions behind the use of rational choice theories, particularly through a...... recurrent oversimplification of international relations literature...
A limiting analysis for edge effects in angle-ply laminates
Hsu, P. W.; Herakovich, C. T.
1976-01-01
A zeroth order solution for edge effects in angle ply composite laminates using perturbation techniques and a limiting free body approach was developed. The general method of solution for laminates is developed and then applied to the special case of a graphite/epoxy laminate. Interlaminar stress distributions are obtained as a function of the laminate thickness to width ratio h/b and compared to existing numerical results. The solution predicts stable, continuous stress distributions, determines finite maximum tensile interlaminar normal stress for two laminates, and provides mathematical evidence for singular interlaminar shear stresses.
Rudenko, I.; Bekchanov, M.; Djanibekov, U.; Lamers, J. P. A.
2013-11-01
Since independence from the former Soviet Union in 1991, Uzbekistan is challenged to consolidate its efforts and identify and introduce suitable agricultural policies to ease the threat of advancing land, water and ecosystem deterioration. On the one hand, irrigated cotton production provides income, food and energy sources for a large part of the rural households, which accounts for about 70% of the total population. On the other hand, this sector is considered a major driver of the on-going environmental degradation. Due to this dual nature, an integrated approach is needed that allows the analyses of the cotton sector at different stages and, consequently, deriving comprehensive options for action. The findings of the economic based value chain analysis and ecologically-oriented water footprint analysis on regional level were complemented with the findings of an input-output model on national level. This combination gave an added value for better-informed decision-making to reach land, water and ecosystem sustainability, compared to the individual results of each approach. The synergy of approaches pointed at various options for actions, such as to (i) promote the shift of water use from the high water consuming agricultural sector to a less water consuming cotton processing sector, (ii) increase overall water use efficiency by expanding the highly water productive industrial sectors and concurrently decreasing sectors with inefficient water use, and (iii) reduce agricultural water use by improving irrigation and conveyance efficiencies. The findings showed that increasing water use efficiency, manufacturing products with higher value added and raising water users' awareness of the real value of water are essential for providing water security in Uzbekistan.
Coefficient of performance and its bounds for general refrigerators with nonisothermal processes
International Nuclear Information System (INIS)
An analysis of the coefficient of performance (COP) and its bounds at maximum χ figure of merit for refrigerators is conducted and the heat transfer processes are described using Newton’s law of cooling with a time-dependent heat conductance. The upper bound of the COP, εCA=√(εC+1)−1, is independent of the time duration completing either process or the heat conductance. The optimal temperature profiles in the heat exchanging processes are analyzed under different dimensionless contact time limits. Provided the dimensionless contact times satisfy certain relations, the endoreversible model is recovered. Furthermore, numerical calculations are conducted to investigate the effect of different heat conductances on temperature profiles under the maximum χ criterion. This work can guide design and operation of actual refrigerators. (paper)
Shape selection of surface-bound helical filaments: biopolymers on curved membranes
Quint, D A; Grason, G M
2016-01-01
Motivated to understand the behavior of biological filaments interacting with membranes of various types, we study a theoretical model for the shape and thermodynamics of intrinsically-helical filaments bound to curved membranes. We show filament-surface interactions lead to a host of non-uniform shape equilibria, in which filaments progressively unwind from their native twist with increasing surface interaction and surface curvature, ultimately adopting uniform-contact curved shapes. The latter effect is due to non-linear coupling between elastic twist and bending of filaments on anisotropically-curved surfaces, such as the cylindrical surfaces considered here. Via a combination of numerical solutions and asymptotic analysis of shape equilibria we show that filament conformations are critically sensitive to the surface curvature in both the strong- and weak-binding limits. These results suggest that local structure of membrane-bound chiral filaments is generically sensitive to the curvature-radius of the sur...
Coefficient of performance and its bounds for general refrigerators with nonisothermal processes
Long, Rui; Liu, Wei
2014-08-01
An analysis of the coefficient of performance (COP) and its bounds at maximum \\chi figure of merit for refrigerators is conducted and the heat transfer processes are described using Newton’s law of cooling with a time-dependent heat conductance. The upper bound of the COP, {{\\varepsilon }_{CA}}=\\sqrt{{{\\varepsilon }_{C}}+1}-1, is independent of the time duration completing either process or the heat conductance. The optimal temperature profiles in the heat exchanging processes are analyzed under different dimensionless contact time limits. Provided the dimensionless contact times satisfy certain relations, the endoreversible model is recovered. Furthermore, numerical calculations are conducted to investigate the effect of different heat conductances on temperature profiles under the maximum \\chi criterion. This work can guide design and operation of actual refrigerators.
Bound states of 'dressed' particles
International Nuclear Information System (INIS)
A new approach to the problem of bound states in relativistic quantum field theories is suggested. It uses the creation - destruction operators of 'dresses' particles which have been granted by Faddeev's (1963) 'dressing' formalism. Peculiarities of the proposed approach as compared to the known ones are discussed. 8 refs. (author)
Semiclassical bounds in magnetic bottles
Czech Academy of Sciences Publication Activity Database
Barseghyan, Diana; Exner, Pavel; Kovařík, H.; Weidl, T.
2016-01-01
Roč. 28, č. 1 (2016), s. 1650002. ISSN 0129-055X R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : magnetic Laplacian * discrete spectrum * eigenvalue bounds Subject RIV: BE - Theoretical Physics Impact factor: 1.329, year: 2014
Unconditional lower bounds against advice
H. Buhrman; L. Fortnow; R. Santhanam
2009-01-01
We show several unconditional lower bounds for exponential time classes against polynomial time classes with advice, including: (1) For any constant c, NEXP not in P^{NP[n^c]} (2) For any constant c, MAEXP not in MA/n^c (3) BPEXP not in BPP/n^{o(1)}. It was previously unknown even whether NEXP in NP
DEFF Research Database (Denmark)
Nielson, Hanne Riis; Nielson, Flemming
1992-01-01
In the context of abstract interpretation the authors study the number of times a functional needs to be unfolded in order to give the least fixed point. For the cases of total or monotone functions they obtain an exponential bound and in the case of strict and additive (or distributive) functions...
Market Access through Bound Tariffs
DEFF Research Database (Denmark)
Sala, Davide; Schröder, Philipp J.H.; Yalcin, Erdal
WTO negotiations deal predominantly with bound - besides applied - tariff rates. But, how can reductions in tariffs ceilings, i.e. tariff rates that no exporter may ever actually be confronted with, generate market access? The answer to this question relates to the effects of tariff bindings on t...
Market access through bound tariffs
DEFF Research Database (Denmark)
Sala, Davide; Schröder, Philipp J.H.; Yalcin, Erdal
2010-01-01
WTO negotiations deal predominantly with bound - besides applied - tariff rates. But, how can reductions in tariffs ceilings, i.e. tariff rates that no exporter may ever actually be confronted with, generate market access? The answer to this question relates to the effects of tariff bindings on t...
Improved Bounds for Geometric Permutations
Rubin, Natan; Sharir, Micha
2010-01-01
We show that the number of geometric permutations of an arbitrary collection of $n$ pairwise disjoint convex sets in $\\mathbb{R}^d$, for $d\\geq 3$, is $O(n^{2d-3}\\log n)$, improving Wenger's 20 years old bound of $O(n^{2d-2})$.
The Limits of Liberalism in Argentine Provinces 1890-1940: An Analysis of Provincial Expenditures
Directory of Open Access Journals (Sweden)
Peter J Ross
2008-02-01
Full Text Available This paper examines the liberal grounded provincial societies of Argentina from 1890 to 1940. A close examination of provincial government expenditures reveals that these states spent most of their revenues on law and order and education with little being directed to social welfare and to health. This form of government was extremely limited, therefore, in providing for the welfare of most of its citizens, and left many of them excluded from full participation in the political, economic and social life of the nation. The type of liberalism espoused by the Argentine elites effectively undermined the very project of state building that they espoused and resulted in the Peronist revolution of the 1940s when the state, under the slogan of social justice, became much more interventionist in the areas of welfare, health and housing, and much more inclusionist with regard to the Argentine people as a whole. The liberal state, and this includes the provinces, became a victim of its own chosen limitations.
Simple frequency-dependent tools for analysis of inherent control limitations
Directory of Open Access Journals (Sweden)
Sigurd Skogestad
1991-10-01
Full Text Available By a plant's inherent control limitations we mean the characteristics of the plant which will cause poor control performance irrespective of what controller is used. Another frequently used term is 'dynamic resilience' which is the best closed-loop performance achievable using any controller. Since a plant's dynamic resilience cannot be altered by change of the control algorithm, but only by design modifications, it follows that the term controllability provides a link between process design and process control. In this paper we focus on two aspects of controllability. The plants' sensitivity to disturbances and the limitations imposed by interactions when using decentralized control. We use simple tools such as the RGA, the PRGA (Performance RGA and the closely related Closed Loop Disturbance Gain (CLDG. For example, if kth column of the CLDG is large, then this indicates that disturbance k will be difficult to reject. This may pinpoint the need for modifying the process. The PRGA provides a measure of interaction which also includes one-way coupling. In the paper we apply these measures to distillation column control and fluid catalytic cracker (FCC control.
Boonstra, A.; van Offenbeek, M.A.G.
2010-01-01
Telecare is the use of information and communication systems to facilitate care delivery to individuals in their homes. Although the expectations of telecare are high, its implementation has proved complex. This case study demonstrates this complexity through a structurational analysis of a telecare
Limited diagnostic value of enzyme analysis in patients with mitochondrial tRNA mutations
DEFF Research Database (Denmark)
Wibrand, Flemming; Jeppesen, Tina Dysgaard; Frederiksen, Anja L;
2010-01-01
We evaluated the diagnostic value of respiratory chain (RC) enzyme analysis of muscle in adult patients with mitochondrial myopathy (MM). RC enzyme activity was measured in muscle biopsies from 39 patients who carry either the 3243A>G mutation, other tRNA point mutations, or single, large...
Limitations of the thermodynamic Gibbs-Thomson analysis of nanoisland decay
Czech Academy of Sciences Publication Activity Database
Kuntová, Zdeňka; Chvoj, Zdeněk; Šíma, V.; Tringides, M. C.
2005-01-01
Roč. 71, č. 12 (2005), 125415/1-125415/9. ISSN 1098-0121 R&D Projects: GA AV ČR(CZ) IAA1010207; GA MŠk(CZ) ME 655 Institutional research plan: CEZ:AV0Z10100521 Keywords : Gibbs -Thompson analysis * nanoislands decay Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.185, year: 2005
Universal Entropy Bound for Rotating Systems
Hod, Shahar
1999-01-01
We conjecture a universal upper bound to the entropy of a rotating system. The entropy bound follows from application of the generalized second law of thermodynamics to an idealized gedanken experiment in which an entropy-bearing rotating system falls into a black hole. This bound is stronger than the Bekenstein entropy bound for non-rotating systems.
Orasche, J.; Schnelle-Kreis, J.; Abbaszade, G.; Zimmermann, R.
2011-05-01
An in-situ derivatization thermal desorption method followed by gas chromatography and time-of-flight mass spectrometry (IDTD-GC-TOFMS) was developed for determination of polar organic compounds. Hydroxyl and carboxyl groups of compounds such as anhydrous sugars, alcohols and phenols, fatty acids and resin acids are targets of the derivatization procedure. Derivatization is based on silylation with N-Methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) during the step of thermal desorption. The high temperature of 300 °C during desorption is utilized for the in-situ derivatization on the collection substrate (quartz fibre filters) accelerating the reaction rate. Thereby, the analysis time is as short as without derivatization. At first the filter surface is dampened with derivatization reagent before insertion of the sample into the thermal desorption unit. To ensure ongoing derivatization during thermal desorption the carrier gas is saturated with MSTFA until the desorption procedure is finished. The method introduced here was compared with direct thermal desorption gas chromatography time-of-flight-mass spectrometry (DTD-GC-TOFMS) and with solvent extraction (SE) procedures followed by gas chromatography and mass spectrometry. Comparisons were carried out with field samples originating from ambient aerosol collected on quartz fibre filters. Moreover, the methods have been applied on NIST Standard Reference Material Urban Dust (SRM 1649a).
Quantifying Bounded Rationality: Managerial Behaviour and the Smith Predictor
Riddalls, C.E.; Bennett, S.
2001-01-01
The concept of bounded rationality in decision making and research on its relegation to aggregate system dynamics is examined. By recasting one such example of a dynamic system, the Beer Game, as a Smith predictor control system is derived. A stability analysis is then employed to support the and qualify the assertion that the level of bounded rationality can adversely affect the aggregate dynamic behaviour of such supply chains. The analytical basis of these calculations enables the qualific...
A strong pair correlation bound implies the CLT for Sinai Billiards
Stenlund, Mikko
2009-01-01
For Dynamical Systems, a strong bound on multiple correlations implies the Central Limit Theorem (CLT) [ChMa]. In Chernov's paper [Ch2], such a bound is derived for dynamically Holder continuous observables of dispersing Billiards. Here we weaken the regularity assumption and subsequently show that the bound on multiple correlations follows directly from the bound on pair correlations. Thus, a strong bound on pair correlations alone implies the CLT, for a wider class of observables. The result is extended to Anosov diffeomorphisms in any dimension.
Single-shot diffraction-limited imaging through scattering layers via bispectrum analysis
Wu, Tengfei; Shao, Xiaopeng; Gigan, Sylvain
2016-01-01
Recently introduced speckle-correlations based techniques enable noninvasive imaging of objects hidden behind scattering layers. In these techniques the hidden object Fourier amplitude is retrieved from the scattered light autocorrelation, and the lost Fourier phase is recovered via iterative phase-retrieval algorithms, which suffer from convergence to wrong local-minima solutions and cannot solve ambiguities in object-orientation. Here, inspired by notions used in astronomy, we experimentally demonstrate that in addition to Fourier amplitude, the object phase information is naturally and inherently encoded in scattered light bispectrum (the Fourier transform of triple-correlation), and can also be extracted from a single high-resolution speckle pattern, based on which we present a single-shot imaging scheme to deterministically and unambiguously retrieve diffraction-limited images of objects hidden behind scattering layers.
Analysis of Dα(Hα) spectrum emitted in front of the limiter in HT-7
Institute of Scientific and Technical Information of China (English)
Huang Juan; Wan Bao-Nian; Deren Stotler; Xiao Bing-Jia; Wu Zhen-Wei; the HT-7 team
2008-01-01
In order to understand the recycling and emission processes of hydrogen atoms in HT-7, spectral profiles of the Dα(Hα) line emitted in front of the limiter have been observed with a high-resolution spectrometer and simulated by using the neutral particle transport code DEGAS 2. The results show that four processes are necessary to interpret the Dα(Hα) line shape: 1) atom desorption, 2) molecular dissociation, 3) particle reflection, and 4) charge-exchange. The products of the first two processes are cold atoms which emit photons near the peak of Dα(Hα) line shape, and those from the last two are warm atoms contributing to the blue side of the spectrum. For a typical ohmic discharge (shot 68520 he(0) ≈ 3 × 1019 m-3), these components contribute 32%, 15%, 32% and 21%, respectively. Dα(Hα) line shapes under different plasma parameters are also discussed in this paper.