A General Nonlinear Optimization Algorithm for Lower Bound Limit Analysis
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
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
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...
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
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
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
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
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...
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
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
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
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
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
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
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
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
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
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
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)
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
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
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
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
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
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
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
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
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
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
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
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
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 ...
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
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
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
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
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
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
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.
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
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
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.
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
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.
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
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
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
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
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
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
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
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
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
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
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
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.
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...
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
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.
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)
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
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
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
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.
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)
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
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...
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
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...
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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.
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
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
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.
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
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...
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
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
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)
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)
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
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
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.
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
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
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
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.
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
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
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
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.
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
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.
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
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)
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
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
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
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.
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
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
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
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
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
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
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.
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...
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.
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
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...
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
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....
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.
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.
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
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...
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
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.
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
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
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.
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.)