A LOWER BOUND LIMIT ANALYSIS OF DUCTILE COMPOSITE MATERIALS
Institute of Scientific and Technical Information of China (English)
Zhang Hongtao; Liu Yinghua; Xu Bingye
2005-01-01
The plastic load-bearing capacity of ductile composites such as metal matrix composites is studied with an insight into the microstructures. The macroscopic strength of a composite is obtained by combining the homogenization theory with static limit analysis, where the temperature parameter method is used to construct the self-equilibrium stress field. An interface failure model is proposed to account for the effects of the interface on the failure of composites.The static limit analysis with the finite-element method is then formulated as a constrained nonlinear programming problem, which is solved by the Sequential Quadratic Programming (SQP)method. Finally, the macroscopic transverse strength of perforated materials, the macroscopic transverse and off-axis strength of fiber-reinforced composites are obtained through numerical calculation. The computational results are in good agreement with the experimental data.
Lower Bound Limit Analysis Of Slabs With Nonlinear Yield Criteria
DEFF Research Database (Denmark)
Krabbenhøft, Kristian; Damkilde, Lars
2002-01-01
A finite element formulation of the limit analysis of perfectly plastic slabs is given. An element with linear moment fields for which equilibrium is satisfied exactly is used in connection with an optimization algorithm taking into account the full nonlinearity of the yield criteria. Both load and...... material optimization problems are formulated and by means of the duality theory of linear programming the displacements are extracted from the dual variables. Numerical examples demonstrating the capabilities of the method and the effects of using a more refined representation of the yield criteria are...
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
A SOLUTION PROCEDURE FOR LOWER BOUND LIMIT AND SHAKEDOWN ANALYSIS BY SGBEM
Institute of Scientific and Technical Information of China (English)
Zhang Xiaofeng; Liu Yinghua; Cen Zhangzhi
2001-01-01
The symmetric Galerkin boundary element method (SGBEM) instead of the finite element method is used to perform lower bound limit and shakedown analysis of structures. The self-equilibrium stress fields are constructed by a linear combination of several basic self-equilibrium stress fields with parameters to be determined. These basic self-equilibrium stress fields are expressed as elastic responses of the body to imposed permanent strains and obtained through elastic-plastic incremental analysis. The complex method is used to solve nonlinear programming and determine the maximal load amplifier. The limit analysis is treated as a special case of shakedown analysis in which only the proportional loading is considered. The numerical results show that SGBEM is effcient and accurate for solving limit and shakedown analysis problems.
Upper-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.
Upper-bound limit analysis based on the natural element method
Institute of Scientific and Technical Information of China (English)
Shu-Tao Zhou; Ying-Hua Liu
2012-01-01
The natural element method (NEM) is a newlydeveloped numerical method based on Voronoi diagram and Delaunay triangulation of scattered points,which adopts natural neighbour interpolation to construct trial functions in the framework of Galerkin method.Owing to its distinctive advantages,the NEM is used widely in many problems of computational mechanics.Utilizing the NEM,this paper deals with numerical limit analysis of structures made up of perfectly rigid-plastic material.According to kinematic theorem of plastic limit analysis,a mathematical programming natural element formulation is established for determining the upper bound multiplier of plane problems,and a direct iteration algorithm is proposed accordingly to solve it.In this algorithm,the plastic incompressibility condition is handled by two different treatments,and the nonlinearity and nonsmoothness of the goal function are overcome by distinguishing the rigid zones from the plastic zones at each iteration.The procedure implementation of iterative process is quite simple and effective because each iteration is equivalent to solving an associated elastic problem.The obtained limit load multiplier is proved to monotonically converge to the upper bound of true solution.Several benchmark examples are investigated to validate the significant performance of the NEM in the application field of limit analysis.
SENSITIVITY ANALYSIS OF THE KNAPSACK PROBLEM: TIGHTER LOWER AND UPPER BOUND LIMITS
Institute of Scientific and Technical Information of China (English)
Tarik BELGACEM; Mhand HIFI
2008-01-01
In this paper, we study the sensitivity of the optimum of the knapsack problem to the perturbation of the profit of a subset of items. We propose a polynomial heuristic in order to establish both lower and upper bound limits of the sensitivity interval. The aim is to stabilize any given optimal solution obtained by applying any exact algorithm. We then evaluate the effectiveness of the proposed solution procedure on an example and a set of randomly generated problem instances.
An Efficient Implementation of Non-Linear Limit State Analysis Based on Lower-Bound Solutions
DEFF Research Database (Denmark)
Damkilde, Lars; Schmidt, Lotte Juhl
2005-01-01
Limit State analysis has been used in design for decades e.g. the yield line theory for concrete slabs or slip line solutions in geotechnics. In engineering practice manual methods have been dominating but in recent years the interest in numerical methods has been increasing. In this respect...
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...
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...
DEFF Research Database (Denmark)
Damkilde, Lars
2007-01-01
Limit State analysis has a long history and many prominent researchers have contributed. The theoretical foundation is based on the upper- and lower-bound theorems which give a very comprehensive and elegant formulation on complicated physical problems. In the pre-computer age Limit State analysi...
Redshift-space limits of bound structures
Duenner, Rolando; Reisenegger, Andreas; Meza, Andres; Araya, Pablo A.; Quintana, Hernan
2007-01-01
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
Pastor, F.; Anoukou, K.; Pastor, J.; Kondo, D.
2016-06-01
This second part of the two-part study is devoted to the numerical Limit Analysis of a hollow sphere model with a Mohr-Coulomb matrix and its use for the assessment of theoretical results. Brief background and fundamental of the static and kinematic approaches in the context of numerical limit analysis are first recalled. We then present the hollow sphere model, together with its axisymmetric FEM discretization and its mechanical position. A conic programming adaptation of a previous iterative static approach, based on a piecewise linearization (PWL) of the plasticity criterion, was first realized. Unfortunately, the resulting code, no more than the PWL one, did not allow sufficiently refined meshes for loss of convergence of the conic optimizer. This problem was solved by using the projection algorithm of Ben Tal and Nemriovski (BTN) and the (interior point) linear programming code XA. For the kinematic approach, a first conic adaptation appeared also inefficient. Then, an original mixed (but fully kinematic) approach dedicated to the general Mohr-Coulomb axisymmetric problem was elaborated. The final conic mixed code appears much more robust than the classic one when using the conic code MOSEK, allowing us to take into account refined numerical meshes. After a fine validation in the case of spherical cavities and isotropic loadings (for which the exact solution is known) and comparison to previous (partial) results, numerical lower and upper bounds (a posteriori verified) of the macroscopic strength are provided. These bounds are used to assess and validate the theoretical results of the companion (part I) paper. Effects of the friction angle as well as that of the porosity are illustrated.
Limit Shapes and Fluctuations of Bounded Random Partitions
DEFF Research Database (Denmark)
Beltoft, Dan
Young diagrams confined to a rectangle. When the rectangle grows, and diagrams are rescaled, the probability measure degenerates to a delta measure on a continuous curve, the limit shape. In the intermediate scaling, the fluctuations around the limit shape turn out to be governed by an Ornstein......-Uhlenbeck process. Similar behaviour occurs in the related models bounded only on one side or not at all, which were studied by Vershik and others....
Automatic analysis of distance bounding protocols
Malladi, Sreekanth; Kothapalli, Kishore
2010-01-01
Distance bounding protocols are used by nodes in wireless networks to calculate upper bounds on their distances to other nodes. However, dishonest nodes in the network can turn the calculations both illegitimate and inaccurate when they participate in protocol executions. It is important to analyze protocols for the possibility of such violations. Past efforts to analyze distance bounding protocols have only been manual. However, automated approaches are important since they are quite likely to find flaws that manual approaches cannot, as witnessed in literature for analysis pertaining to key establishment protocols. In this paper, we use the constraint solver tool to automatically analyze distance bounding protocols. We first formulate a new trace property called Secure Distance Bounding (SDB) that protocol executions must satisfy. We then classify the scenarios in which these protocols can operate considering the (dis)honesty of nodes and location of the attacker in the network. Finally, we extend the const...
Lower bound limit load of a circumferentially cracked pipe under combined mechanical loading
International Nuclear Information System (INIS)
In a study on extension of the reference stress method, for J simplified assessment, to a three dimensional (3D) configuration under combined loading, lower bound limit analysis has been developed by J. Desquines. In the present paper the limit load for cracked pipe, with a 3D circumferential flaw, under pressure, tension and bending is detailed. The limit load is explicitly defined as a yield surface is the 3D space loading. A simple algorithm is proposed to solve the non linear problem associated to the reference stress calculation. Moreover, the lower bound solution is compared with elastic compensation method (ECM) results computed on a 3D finite element mesh of the cracked pipe. The lower bound yield surface underestimates the numerical limit loads with a discrepancy lower than 20%. (orig.)
An Improved Lower Bound Limit State Optimisation Algorithm
DEFF Research Database (Denmark)
Frier, Christian; Damkilde, Lars
2010-01-01
Limit State analysis has been used in engineering practice for many years e.g. the yield-line method for concrete slabs and slip-line solutions in geotechnics. In the recent years there has been an increased interest in numerical Limit State analysis, and today algorithms take into account the non...
An Improved Lower Bound Limit State Optimisation Algorithm
DEFF Research Database (Denmark)
Frier, Christian; Damkilde, Lars
2010-01-01
Limit State analysis has been used in manual design methods for decades e.g. the yield line theory for concrete slabs.......Limit State analysis has been used in manual design methods for decades e.g. the yield line theory for concrete slabs....
Some distance bounds of branching processes and their diffusion limits
Kammerer, Niels B
2010-01-01
We compute exact values respectively bounds of "distances" - in the sense of (transforms of) power divergences and relative entropy - between two discrete-time Galton-Watson branching processes with immigration GWI for which the offspring as well as the immigration is arbitrarily Poisson-distributed (leading to arbitrary type of criticality). Implications for asymptotic distinguishability behaviour in terms of contiguity and entire separation of the involved GWI are given, too. Furthermore, we determine the corresponding limit quantities for the context in which the two GWI converge to Feller-type branching diffusion processes, as the time-lags between observations tend to zero. Some applications to (static random environment like) Bayesian decision making and Neyman-Pearson testing are presented as well.
Evaluating risk using bounding calculations and limited data; TOPICAL
International Nuclear Information System (INIS)
This paper describes a methodology for estimating the potential risk to workers and the public from igniting organic solvents in any of the 177 underground waste storage tanks at the Hanford Site in southeastern Washington state. The Hanford Site is one of the U.S. Department of Energy's former production facilities for nuclear materials. The tanks contain mixed radioactive wastes. Risk is measured by calculating toxicological and radiological accident consequences and frequencies and comparing the results to established regulatory guidelines. Available sample data is insufficient to adequately characterize the waste and solvent, so a model that maximizes releases from the tanks (bounding case) is used. Maximizing releases (and thus consequences) is a standard technique used in safety analysis to compensate for lack of information. The model predicts bounding values of fire duration, the time at which the fire extinguishes because of lack of oxygen, and a pressure history of a fire in a tank. The model output is used to calculate mass and volume release rates of material from the tanks. The mass and volume release rates permit calculation of radiological and toxicological consequences. The resulting consequence calculations demonstrate that risk from an organic solvent fire in the tanks is within regulatory guidelines
Evaluating risk using bounding calculations and limited data
Energy Technology Data Exchange (ETDEWEB)
COWLEY, W.L.
1999-05-27
This paper describes a methodology for estimating the potential risk to workers and the public from igniting organic solvents in any of the 177 underground waste storage tanks at the Hanford Site in southeastern Washington state. The Hanford Site is one of the U.S. Department of Energy's former production facilities for nuclear materials. The tanks contain mixed radioactive wastes. Risk is measured by calculating toxicological and radiological accident consequences and frequencies and comparing the results to established regulatory guidelines. Available sample data is insufficient to adequately characterize the waste and solvent, so a model that maximizes releases from the tanks (bounding case) is used. Maximizing releases (and thus consequences) is a standard technique used in safety analysis to compensate for lack of information. The model predicts bounding values of fire duration, the time at which the fire extinguishes because of lack of oxygen, and a pressure history of a fire in a tank. The model output is used to calculate mass and volume release rates of material from the tanks. The mass and volume release rates permit calculation of radiological and toxicological consequences. The resulting consequence calculations demonstrate that risk from an organic solvent fire in the tanks is within regulatory guidelines.
OFFSITE RADIOLOGICAL CONSEQUENCE ANALYSIS FOR THE BOUNDING FLAMMABLE GAS ACCIDENT
International Nuclear Information System (INIS)
This document quantifies the offsite radiological consequences of the bounding flammable gas accident for comparison with the 25 rem Evaluation Guideline established in DOE-STD-3009, Appendix A. The bounding flammable gas accident is a detonation in a SST. The calculation applies reasonably conservative input parameters in accordance with guidance in DOE-STD-3009, Appendix A. The purpose of this analysis is to calculate the offsite radiological consequence of the bounding flammable gas accident. DOE-STD-3009-94, ''Preparation Guide for US. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', requires the formal quantification of a limited subset of accidents representing a complete set of bounding conditions. The results of these analyses are then evaluated to determine if they challenge the DOE-STD-3009-94, Appendix A, ''Evaluation Guideline,'' of 25 rem total effective dose equivalent in order to identify and evaluate safety-class structures, systems, and components. The bounding flammable gas accident is a detonation in a single-shell tank (SST). A detonation versus a deflagration was selected for analysis because the faster flame speed of a detonation can potentially result in a larger release of respirable material. A detonation in an SST versus a double-shell tank (DST) was selected as the bounding accident because the estimated respirable release masses are the same and because the doses per unit quantity of waste inhaled are greater for SSTs than for DSTs. Appendix A contains a DST analysis for comparison purposes
The Limits of Bound Structures in the Accelerating Universe
D"unner, R; Meza, A; Reisenegger, A; D\\"unner, Rolando; Araya, Pablo A.; Meza, Andr\\'es; Reisenegger, Andreas
2006-01-01
According to the latest evidence, the Universe is entering an era of exponential expansion, where gravitationally bound structures will get disconnected from each other, forming isolated `island universes'. In this scenario, we present a theoretical criterion to determine the boundaries of gravitationally bound structures and a physically motivated definition of superclusters as the largest bound structures in the Universe. We use the spherical collapse model self-consistently to obtain an analytical condition for the mean density enclosed by the last bound shell of the structure (2.36 times the critical density in the present Universe, assumed to be flat, with 30 per cent matter and 70 per cent cosmological constant, in agreement with the previous, numerical result of Chiueh and He). $N$-body simulations extended to the future show that this criterion, applied at the present cosmological epoch, defines a sphere that encloses $\\approx 99.7$ per cent of the particles that will remain bound to the structure at ...
Quantum computation speedup limits from quantum metrological precision bounds
Demkowicz-Dobrzanski, Rafal; Markiewicz, Marcin
2014-01-01
We propose a scheme for translating metrological precision bounds into lower bounds on query complexity of quantum search algorithms. Within the scheme the link between quadratic performance enhancement in idealized quantum metrological and quantum computing schemes becomes clear. More importantly, we utilize results from the field of quantum metrology on a generic loss of quadratic quantum precision enhancement in presence of decoherence to infer an analogous generic loss of quadratic speed-...
Offsite radiological consequence analysis for the bounding flammable gas accident
International Nuclear Information System (INIS)
The purpose of this analysis is to calculate the offsite radiological consequence of the bounding flammable gas accident. DOE-STD-3009-94, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', requires the formal quantification of a limited subset of accidents representing a complete set of bounding conditions. The results of these analyses are then evaluated to determine if they challenge the DOE-STD-3009-94, Appendix A, ''Evaluation Guideline,'' of 25 rem total effective dose equivalent in order to identify and evaluate safety class structures, systems, and components. The bounding flammable gas accident is a detonation in a single-shell tank (SST). A detonation versus a deflagration was selected for analysis because the faster flame speed of a detonation can potentially result in a larger release of respirable material. As will be shown, the consequences of a detonation in either an SST or a double-shell tank (DST) are approximately equal. A detonation in an SST was selected as the bounding condition because the estimated respirable release masses are the same and because the doses per unit quantity of waste inhaled are generally greater for SSTs than for DSTs. Appendix A contains a DST analysis for comparison purposes
Institute of Scientific and Technical Information of China (English)
安晨歌; 张建红; 周敏; 朱政
2011-01-01
海床中的天然气水合物分解后由固体变为气体,将直接提高孔隙水压力,减小边坡内有效应力,导致边坡稳定性下降.本文以能量上限定理为理论基础,采用二维极限分析方法分析海底缓倾角边坡的滑坡机理,研究由于水合物分解形成的软弱夹层对边坡稳定性的影响.分析表明,软弱夹层的埋深和海床土体内摩擦角会对边坡的稳定性产生直接影响.由于水合物分解而产生的膨胀压力也会降低海底缓倾角边坡的稳定性.%It is indicated by some experimental and theoretical data that the disassociation of gas hydrate could directly increase pore water pressure, decrease effective stresses in the submarine slope, reduce the friction coefficient between different soil layers in slope, and in consequence the slope stability will be weakened. In this paper, a two-dimensional numerical limit analysis, incorporating the upper-bound energy method, is presented to improve the understanding of the failure mechanism of submarine low-angle slope. Based on the analysis, it is found that the internal friction angle and the burial depth of weak layer affect the slope stability. It is also found that the expansion pressure due to gas hydrate disassociation in weak layer can affect the stability also.
International Nuclear Information System (INIS)
In this paper it is presented a variational method for the limit analysis of an ideal plastic solid. This method has been denominated as Modified Secundary Creep and enables to find the collapse loads through a minimization of a functional and a limit process. Given an ideal plastic material it is shown how to determinate the associated secundary creep constitutive equation. Finally, as an application, it is found the limit load in an pressurized von Mises rigid plastic sphere. (Author)
Organically bound tritium analysis in environmental samples
Energy Technology Data Exchange (ETDEWEB)
Baglan, N. [CEA/DAM/DIF, Arpajon (France); Kim, S.B. [AECL, Chalk River Laboratories, Chalk River, ON (Canada); Cossonnet, C. [IRSN/PRP-ENV/STEME/LMRE, Orsay (France); Croudace, I.W.; Warwick, P.E. [GAU-Radioanalytical, University of Southampton, Southampton (United Kingdom); Fournier, M. [IRSN/DG/DMQ, Fontenay-aux-Roses (France); Galeriu, D. [IFIN-HH, Horia-Hulubei, Inst. Phys. and Nucl. Eng., Bucharest (Romania); Momoshima, N. [Kyushu University, Radioisotope Ctr., Fukuoka (Japan); Ansoborlo, E. [CEA/DEN/DRCP/CETAMA, Bagnols-sur-Ceze (France)
2015-03-15
Organically bound tritium (OBT) has become of increased interest within the last decade, with a focus on its behaviour and also its analysis, which are important to assess tritium distribution in the environment. In contrast, there are no certified reference materials and no standard analytical method through the international organization related to OBT. In order to resolve this issue, an OBT international working group was created in May 2012. Over 20 labs from around the world participated and submitted their results for the first intercomparison exercise results on potato (Sep 2013). The samples, specially-prepared potatoes, were provided in March 2013 to each participant. Technical information and results from this first exercise are discussed here for all the labs which have realised the five replicates necessary to allow a reliable statistical treatment. The results are encouraging as the increased number of participating labs did not degrade the observed dispersion of the results for a similar activity level. Therefore, the results do not seem to depend on the analytical procedure used. From this work an optimised procedure can start to be developed to deal with OBT analysis and will guide subsequent planned OBT trials by the international group.
Limitations of Lower-Bound Methods for the Wire Complexity of Boolean Operators
Drucker, Andrew
2012-01-01
We study the circuit complexity of Boolean operators, i.e., collections of Boolean functions defined over a common input. Our focus is the well-studied model in which arbitrary Boolean functions are allowed as gates, and in which a circuit's complexity is measured by its depth and number of wires. We show sharp limitations of several existing lower-bound methods for this model. First, we study an information-theoretic lower-bound method due to Cherukhin, that yields bounds of form $\\Omega_d(n...
Simplified Drift Analysis for Proving Lower Bounds in Evolutionary Computation
DEFF Research Database (Denmark)
Oliveto, Pietro S.; Witt, Carsten
2011-01-01
Drift analysis is a powerful tool used to bound the optimization time of evolutionary algorithms (EAs). Various previous works apply a drift theorem going back to Hajek in order to show exponential lower bounds on the optimization time of EAs. However, this drift theorem is tedious to read and to...
The condition of a finite Markov chain and perturbation bounds for the limiting probabilities
Meyer, C. D., Jr.
1979-01-01
The inequalities bounding the relative error the norm of w- w squiggly/the norm of w are exhibited by a very simple function of E and A. Let T denote the transition matrix of an ergodic chain, C, and let A = I - T. Let E be a perturbation matrix such that T squiggly = T - E is also the transition matrix of an ergodic chain, C squiggly. Let w and w squiggly denote the limiting probability (row) vectors for C and C squiggly. The inequality is the best one possible. This bound can be significant in the numerical determination of the limiting probabilities for an ergodic chain. In addition to presenting a sharp bound for the norm of w-w squiggly/the norm of w an explicit expression for w squiggly will be derived in which w squiggly is given as a function of E, A, w and some other related terms.
Analysis of Price Stackelberg Duopoly Game with Bounded Rationality
Directory of Open Access Journals (Sweden)
Lian Shi
2014-01-01
Full Text Available The classical Stackelberg game is extended to boundedly rational price Stackelberg game, and the dynamic duopoly game model is described in detail. By using the theory of bifurcation of dynamical systems, the existence and stability of the equilibrium points of this model are studied. And some comparisons with Bertrand game with bounded rationality are also performed. Stable region, bifurcation diagram, The Largest Lyapunov exponent, strange attractor, and sensitive dependence on initial conditions are used to show complex dynamic behavior. The results of theoretical and numerical analysis show that the stability of the price Stackelberg duopoly game with boundedly rational players is only relevant to the speed of price adjustment of the leader and not relevant to the follower’s. This is different from the classical Cournot and Bertrand duopoly game with bounded rationality. And the speed of price adjustment of the boundedly rational leader has a destabilizing effect on this model.
Size-change Termination and Bound Analysis
DEFF Research Database (Denmark)
Avery, James Emil
2006-01-01
Despite its simplicity, the size-change termination principle, presented by Lee, Jones and Ben-Amram in [LJB01], is surprisingly strong and is able to show termination for a large class of programs. A significant limitation for its use, however, is the fact that the SCT requires data types...
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.
Bound on range precision for shot-noise limited ladar systems.
Johnson, Steven; Cain, Stephen
2008-10-01
The precision of ladar range measurements is limited by noise. The fundamental source of noise in a laser signal is the random time between photon arrivals. This phenomenon, called shot noise, is modeled as a Poisson random process. Other noise sources in the system are also modeled as Poisson processes. Under the Poisson-noise assumption, the Cramer-Rao lower bound (CRLB) on range measurements is derived. This bound on the variance of any unbiased range estimate is greater than the CRLB derived by assuming Gaussian noise of equal variance. Finally, it is shown that, for a ladar capable of dividing a fixed amount of energy into multiple laser pulses, the range precision is maximized when all energy is transmitted in a single pulse.
Numerical Limit Analysis of Reinforced Concrete Structures
DEFF Research Database (Denmark)
Larsen, Kasper Paaske
For more than half a century, limit state analysis based on the extremum principles have been used to assess the load bearing capacity of reinforced concrete structures. Extensi- ve research within the field has lead to several techniques for performing such analysis manually. While these manual...... limit state analysis problems. The work focuses on determination of the load bearing capacity of reinforced concrete structures by employing the lower bound theorem and a finite element method using equilibrium elements is developed. The recent year’s development within the field of convex optimization...... is applied to solve the limit state problems. Three different element types have been developed and tested. The first is a solid tetra- hedral element with a linear stress distribution. The tri-axial stress state in the element is decomposed into concrete and reinforcement stresses, to which separate yield...
Pressure transient analysis methods for bounded naturally fractured reservoirs
Energy Technology Data Exchange (ETDEWEB)
Chen, C-C; Raghavan, R.; Reynolds, A.C.; Serra, K.
1985-06-01
New methods for analyzing drawdown and buildup pressure data obtained at a well located in an infinite, naturally fractured reservoir were presented recently. In this work, the analysis of both drawdown and buildup data in a bounded, naturally fractured reservoir is considered. For the bounded case, the authors show that five possible flow regimes may be exhibited by drawdown data. They delineate the conditions under which each of these five flow regimes exists and the information that can be obtained from each possible combination of flow regimes. Conditions under which semilog methods can be used to analyze buildup data are discussed for the bounded fractured reservoir case. New Matthews-Brons-Hazebroek (MBH) functions for computing the average reservoir pressure from buildup data are presented.
Upper bound analysis for deep tunnel face with joined failure mechanism of translation and rotation
Institute of Scientific and Technical Information of China (English)
许敬叔; 杜佃春; 杨子汉
2015-01-01
A joined failure mechanism of translation and rotation was proposed for the stability analysis of deep tunnel face, and the upper bound solution of supporting force of deep tunnel was calculated under pore water pressure. The calculations were based on limit analysis method of upper bound theory, with the employment of non-associated Mohr-Coulomb flow rule. Nonlinear failure criterion was adopted. Optimized analysis was conducted for the effects of the tunnel depth, pore water pressure coefficient, the initial cohesive force and nonlinear coefficient on supporting force. The upper bound solutions are obtained by optimum method. Results are listed and compared with the previously published solutions for the verification of correctness and effectiveness. The failure shapes are presented, and results are discussed for different pore water pressure coefficients and nonlinear coefficients of tunnel face.
Probability bounds analysis for nonlinear population ecology models.
Enszer, Joshua A; Andrei Măceș, D; Stadtherr, Mark A
2015-09-01
Mathematical models in population ecology often involve parameters that are empirically determined and inherently uncertain, with probability distributions for the uncertainties not known precisely. Propagating such imprecise uncertainties rigorously through a model to determine their effect on model outputs can be a challenging problem. We illustrate here a method for the direct propagation of uncertainties represented by probability bounds though nonlinear, continuous-time, dynamic models in population ecology. This makes it possible to determine rigorous bounds on the probability that some specified outcome for a population is achieved, which can be a core problem in ecosystem modeling for risk assessment and management. Results can be obtained at a computational cost that is considerably less than that required by statistical sampling methods such as Monte Carlo analysis. The method is demonstrated using three example systems, with focus on a model of an experimental aquatic food web subject to the effects of contamination by ionic liquids, a new class of potentially important industrial chemicals.
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...
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.
Persistence-Based Branch Misprediction Bounds for WCET Analysis
DEFF Research Database (Denmark)
Puffitsch, Wolfgang
2015-01-01
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 dyna...... 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....
PLASTIC LIMIT ANALYSIS OF DISCONTINUOUS LINING UNDERGROUND PRESSURE
Institute of Scientific and Technical Information of China (English)
龙春安
1999-01-01
Discontinuous lining is a special form of support in underground excavation. Based on the method of plastic limit analysis, it is found the upper and the lower bound solution of the pressure of circular discontinuous lining and discussed support parameter of discontinuous lining and its applicable conditions, which provides theoretical basis for the design and calculation of discontinuous lining.
Institute of Scientific and Technical Information of China (English)
ZHAO Lian-heng; LI Liang; YANG Feng; LUO Qiang; LIU Xiang
2010-01-01
Based on the upper bound limit analysis theorem and the shear strength reduction technique,the equation for expressing critical limit-equilibrium state was employed to define the safety factor of a given slope and its corresponding critical failure mechanism by means of the kinematical approach of limit analysis theory.The nonlinear shear strength parameters were treated as variable parameters and a kinematically admissible failure mechanism was considered for calculation schemes.The iterative optimization method was adopted to obtain the safety factors.Case study and comparative analysis show that solutions presented here agree with available predictions when nonlinear criterion reduces to linear criterion,and the validity of present method could be illuminated.From the numerical results,it can also be seen that nonlinear parameter m,slope foot gradient β,height of slope H,slope top gradient a and soil bulk density Y have significant effects on the safety factor of the slope.
ON AVERAGE CASE ANALYSIS THROUGH STATISTICAL BOUNDS : LINKING THEORY TO PRACTICE
Directory of Open Access Journals (Sweden)
Niraj Kumar Singh
2013-02-01
Full Text Available Theoretical analysis of algorithms involves counting of operations and a separate bound is provided for a specific operation type. Such a methodology is plagued with its inherent limitations. In this paper we argue as to why we should prefer weight based statistical bounds, which permit mixing of operations, instead as a robust approach. Empirical analysis is an important idea and should be used to supplement and compliment its existing theoretical counterpart as empirically we can work on weights (e.g. time of an operation can be taken as its weight. Not surprisingly, it should not only be taken as an opportunity so as to amend the mistakes already committed knowingly or unknowingly but also to tell a new story.
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
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...
Institute of Scientific and Technical Information of China (English)
刘杰; 黄达; 杨超; 孙莎
2015-01-01
Stability analysis of gravity retaining wall was currently based on the assumption that the wall had no embedment depth. The effect of earth berm was usually neglected. The present work highlighted the importance of embedment depth when assessing the seismic stability of gravity retaining walls with the pattern of pure rotation. In the framework of upper bound theorem of limit analysis, pseudo-static method was applied into two groups of parallel rigid soil slices methods in order to account for the effect of embedment depth on evaluating the critical acceleration of wall-soil system. The present analytical solution is identical to the results obtained from using limit equilibrium method, and the two methods are based on different theory backgrounds. Parameter analysis indicates that the critical acceleration increases slowly when the ratio of the embedment depth to the total height of the wall is from 0 to 0.15 and increases drastically when the ratio exceeds 0.15.
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.
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
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.
(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.
UNIQUENESS AND DISTRIBUTION OF LIMIT CYCLES FOR BOUNDED QUADRATIC SYSTEM%有界二次系统极限环的唯一性及分布
Institute of Scientific and Technical Information of China (English)
宋矞
2001-01-01
In this paper, we first give a necessary and sufficient condition of a quadratic system with three finite critical points being bounded, and then, we use the methods and conclusions of [11] to provide some uniqueness theorems of limit cycles for bounded quadratic systems. As well, we prove that any bounded quadratic system can not have (2, 2)-distribution of limit cycles according to these uniqueness theorems.
Wang, Yong
2016-09-01
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 orders. The problem is studied in a three dimensional bounded domain with Navier-slip type boundary conditions. It is shown that there exists a unique strong solution to the full compressible Navier-Stokes system with the boundary conditions in a finite time interval which is independent of the viscosity and heat conductivity. The solution is uniformly bounded in {W^{1,infty}} and is a conormal Sobolev space. Based on such uniform estimates, we prove the convergence of the solutions of the full compressible Navier-Stokes to the corresponding solutions of the full compressible Euler system in {L^infty(0,T; L^2)}, {L^infty(0,T; H1)} and {L^infty([0,T]×Ω)} with a rate of convergence.
WKB formalism and a lower limit for the energy eigenstates of bound states for some potentials
Barragan-Gil, L F; Barragan-Gil, Luis F.; Camacho, Abel
2007-01-01
In the present work the conditions appearing in the WKB approximation formalism of quantum mechanics are analyzed. It is shown that, in general, a careful definition of an approximation method requires the introduction of two length parameters, one of them always considered in the text books on quantum mechanics, whereas the second one is usually neglected. Afterwards we define a particular family of potentials and prove, resorting to the aforementioned length parameters, that we may find an energy which is a lower bound to the ground energy of the system. The idea is applied to the case of a harmonic oscillator and also to a particle freely falling in a homogeneous gravitational field, and in both cases the consistency of our method is corroborated. This approach, together with the Rayleigh--Ritz formalism, allows us to define an energy interval in which the ground energy of any potential, belonging to our family, must lie.
Boundness of a Neural Network Weights Using the Notion of a Limit of a Sequence
Directory of Open Access Journals (Sweden)
Hazem Migdady
2014-06-01
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 nticipation of the behavior of a neural network weights. The weights of a neural network ar e 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 usedin 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 t he neural network are upper bounded (i.e. they do not approach infinity.
Boundness of a Neural Network Weights Using the Notion of a Limit of a Sequence
Directory of Open Access Journals (Sweden)
Hazem Migdady
2014-05-01
Full Text Available feed forward neural network with backpropagation learning algorithm is considered as a black box learning classifier since there is no certain interpretation or anticipation of the behavior of a neural network weights. The weights of a neural network are considered as the learning tool of the classifier, and the learning task is performed by the repetition modification of those weights. This modification is performed using the delta rule which is mainly used in the gradient descent technique. In this article a proof is provided that helps to understand and explain the behavior of the weights in a feed forward neural network with backpropagation learning algorithm. Also, it illustrates why a feed forward neural network is not always guaranteed to converge in a global minimum. Moreover, the proof shows that the weights in the neural network are upper bounded (i.e. they do not approach infinity.
Fitness levels with tail bounds for the analysis of randomized search heuristics
DEFF Research Database (Denmark)
Witt, Carsten
2014-01-01
The fitness-level method, also called the method of f-based partitions, is an intuitive and widely used technique for the running time analysis of randomized search heuristics. It was originally defined to prove upper and lower bounds on the expected running time. Recently, upper tail bounds were...
Finite Element Method and Upper-Bound Type Analysis of Equal Channel Angular Pressing
Directory of Open Access Journals (Sweden)
T. A. Fashanu
2012-10-01
Full Text Available This work presents the analysis of stresses required for a frictionless equal-channel angular pressing (ECAP of perfectly plastic or strain-hardening materials using finite-element method and upper-bound type analysis. Upper-bound type and FEM analysis were analytical approximations and numerical methods respectively. The two methods used and presented agree well for different ECAP die angles and materials.
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.
Computational structural analysis: multiple proteins bound to DNA.
Directory of Open Access Journals (Sweden)
Andrija Tomovic
Full Text Available BACKGROUND: With increasing numbers of crystal structures of proteinratioDNA and proteinratioproteinratioDNA complexes publically available, it is now possible to extract sufficient structural, physical-chemical and thermodynamic parameters to make general observations and predictions about their interactions. In particular, the properties of macromolecular assemblies of multiple proteins bound to DNA have not previously been investigated in detail. METHODOLOGY/PRINCIPAL FINDINGS: We have performed computational structural analyses on macromolecular assemblies of multiple proteins bound to DNA using a variety of different computational tools: PISA; PROMOTIF; X3DNA; ReadOut; DDNA and DCOMPLEX. Additionally, we have developed and employed an algorithm for approximate collision detection and overlapping volume estimation of two macromolecules. An implementation of this algorithm is available at http://promoterplot.fmi.ch/Collision1/. The results obtained are compared with structural, physical-chemical and thermodynamic parameters from proteinratioprotein and single proteinratioDNA complexes. Many of interface properties of multiple proteinratioDNA complexes were found to be very similar to those observed in binary proteinratioDNA and proteinratioprotein complexes. However, the conformational change of the DNA upon protein binding is significantly higher when multiple proteins bind to it than is observed when single proteins bind. The water mediated contacts are less important (found in less quantity between the interfaces of components in ternary (proteinratioproteinratioDNA complexes than in those of binary complexes (proteinratioprotein and proteinratioDNA.The thermodynamic stability of ternary complexes is also higher than in the binary interactions. Greater specificity and affinity of multiple proteins binding to DNA in comparison with binary protein-DNA interactions were observed. However, protein-protein binding affinities are stronger in
The limit analysis in soil and rock:a mature discipline of geomechanics
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
The solution of a slope stability problem can be approached by its least upper-bound and maximum lower-bound with high accuracy. The limit equilibrium methods that employ vertical slices imply a lower bound of the factor of safety. It has been successfully extended to the area of active earth pressure analysis that accounts for different input of locations of earth pressure applications. Those methods that employ slices with inclined interfaces give an upper-bound approach to the stability analysis. It enjoys a sound mechanical background and is able to provide accurate solutions of soil plasticity. It has been successfully extended to the area of bearing capacity analysis in which various empirical coefficients are no longer necessary. The 3D upper- and lower-bound methods under this framework have been made possible and show great potential for solving various engineering problems.
Bounding axial profile analysis for the topical report database
International Nuclear Information System (INIS)
Quantifying the open-quotes end effectsclose quotes reactivities of realistic end-of-cycle burnup distributions is important in performing criticality safety analyses for spent fuel shipping containers. Yankee Atomic Electric Company has compiled an axial burnup profile database (ABPD) for a large number of PWR fuel types. The profiles for fuel types with initially uniform axial loadings of U-235 and burnable poisons were collected from the ABPD to form the topical report database (TRD). Based on the TRD, a strategy was set up to find bounding profiles which conservatively estimate the maximum open-quotes end effectsclose quotes reactivities in different burnup ranges. A two-group, one-dimensional diffusion code, REALAX, was used to calculate the k-effectives and open-quotes end effectsclose quotes reactivities for each of the axially varying burnup distributions in the TRD. REALAX was also proven to have consistency with the well-known three-dimensional, multi-group diffusion code, DIF3D
Gleiser, Marcelo
2013-01-01
Spatially-bound objects across diverse length and energy scales are characterized by a binding energy. We propose that their spatial structure is mathematically encoded as information in their momentum modes and described by a measure known as configurational entropy (CE). Investigating solitonic Q-balls and stars with a polytropic equation of state $P = K{\\rho}^{\\gamma}$, we show that objects with large binding energy have low CE, whereas those at the brink of instability (zero binding energy) have near maximal CE. In particular, we use the CE to find the critical charge allowing for classically stable Q-balls and the Chandrasekhar limit for white dwarfs $({\\gamma} = 4/3)$ with an accuracy of a few percent.
Energy Technology Data Exchange (ETDEWEB)
Gleiser, Marcelo, E-mail: mgleiser@dartmouth.edu; Sowinski, Damian, E-mail: Damian.Sowinski.GR@dartmouth.edu
2013-11-25
Spatially-bound objects across diverse length and energy scales are characterized by a binding energy. We propose that their spatial structure is mathematically encoded as information in their momentum modes and described by a measure known as configurational entropy (CE) [1]. Investigating solitonic Q-balls and stars with a polytropic equation of state P=Kρ{sup γ}, we show that objects with large binding energy have low CE, whereas those at the brink of instability (zero binding energy) have near maximal CE. In particular, we use the CE to find the critical charge allowing for classically stable Q-balls and the Chandrasekhar limit for white dwarfs (γ=4/3) with an accuracy of a few percent.
Dependence in probabilistic modeling, Dempster-Shafer theory, and probability bounds analysis.
Energy Technology Data Exchange (ETDEWEB)
Oberkampf, William Louis; Tucker, W. Troy (Applied Biomathematics, Setauket, NY); Zhang, Jianzhong (Iowa State University, Ames, IA); Ginzburg, Lev (Applied Biomathematics, Setauket, NY); Berleant, Daniel J. (Iowa State University, Ames, IA); Ferson, Scott (Applied Biomathematics, Setauket, NY); Hajagos, Janos (Applied Biomathematics, Setauket, NY); Nelsen, Roger B. (Lewis & Clark College, Portland, OR)
2004-10-01
This report summarizes methods to incorporate information (or lack of information) about inter-variable dependence into risk assessments that use Dempster-Shafer theory or probability bounds analysis to address epistemic and aleatory uncertainty. The report reviews techniques for simulating correlated variates for a given correlation measure and dependence model, computation of bounds on distribution functions under a specified dependence model, formulation of parametric and empirical dependence models, and bounding approaches that can be used when information about the intervariable dependence is incomplete. The report also reviews several of the most pervasive and dangerous myths among risk analysts about dependence in probabilistic models.
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...
Limit Analysis of 3D Reinforced Concrete Beam Elements
DEFF Research Database (Denmark)
Larsen, Kasper P.; Nielsen, Leif Otto; Poulsen, Peter Noe
2012-01-01
A new finite-element framework for lower-bound limit analysis of reinforced concrete beams, subjected to loading in three dimensions, is presented. The method circumvents the need for a direct formulation of a complex section-force-based yield criterion by creating a discrete representation...... 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....
Bounded Delay Timing Analysis of a Class of CSP Programs
DEFF Research Database (Denmark)
Hulgaard, Henrik; Burns, Steven M.
1997-01-01
. 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......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...
Cryptographic protocol security analysis based on bounded constructing algorithm
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
An efficient approach to analyzing cryptographic protocols is to develop automatic analysis tools based on formal methods. However, the approach has encountered the high computational complexity problem due to reasons that participants of protocols are arbitrary, their message structures are complex and their executions are concurrent. We propose an efficient automatic verifying algorithm for analyzing cryptographic protocols based on the Cryptographic Protocol Algebra (CPA) model proposed recently, in which algebraic techniques are used to simplify the description of cryptographic protocols and their executions. Redundant states generated in the analysis processes are much reduced by introducing a new algebraic technique called Universal Polynomial Equation and the algorithm can be used to verify the correctness of protocols in the infinite states space. We have implemented an efficient automatic analysis tool for cryptographic protocols, called ACT-SPA, based on this algorithm, and used the tool to check more than 20 cryptographic protocols. The analysis results show that this tool is more efficient, and an attack instance not offered previously is checked by using this tool.
Extrinsic Isoperimetric Analysis on Submanifolds with Curvatures bounded from below
DEFF Research Database (Denmark)
Markvorsen, Steen; Palmer, Vicente
2010-01-01
within the extrinsic ball from a given starting point before they hit the boundary of the extrinsic ball. In those cases, where we may extend our analysis to hold all the way to infinity, we apply a capacity comparison technique to obtain a sufficient condition for the submanifolds to be parabolic, i...
Time domain reflectometry waveform analysis with second order bounded mean oscillation
Tangent-line methods and adaptive waveform interpretation with Gaussian filtering (AWIGF) have been proposed for determining reflection positions of time domain reflectometry (TDR) waveforms. However, the accuracy of those methods is limited for short probe TDR sensors. Second order bounded mean osc...
Bound analysis of target displacement for seismic performance assessment of buildings
Institute of Scientific and Technical Information of China (English)
JIA Li-zhe; DUAN Zhong-dong; LU Qin-nian
2008-01-01
The earthquake demand spectrum is often assumed as the average spectrum in the seismic design code or based upon probabilistic models to take into account the uncertainties of ground motion. The average spectrum can not deal with the uncertainty of earthquake excitation. Furthermore, results of probabilistic analy-sis are suspicious when information describing the uncertainty is inadequate. Considering the uncertainties of peak acceleration of ground motion and characteristic period of response spectra using a double bounded convex set model, the bounds of the design spectrum and the demand spectrum were obtained based on Chinese seismiccode. Then the convex analysis method was integrated into the capacity spectrum procedure to study the bound characteristics of target displacement. Finally, the target displacement was derived with an interval, and it is more objective and robust with respect to probabilistic perspective.
Directory of Open Access Journals (Sweden)
Qi Wang
Full Text Available The energy minimization of a small molecule alone does not automatically stop at a local minimum of the potential energy surface of the molecule if the minimum is shallow, thus leading to folding of the molecule and consequently hampering the generation of the bound conformation of a guest in the absence of its host. This questions the practicality of virtual screening methods that use conformations at local minima of their potential energy surfaces (local minimum conformations as potential bound conformations. Here we report a normal-mode-analysis-monitored energy minimization (NEM procedure that generates local minimum conformations as potential bound conformations. Of 22 selected guest-host complex crystal structures with guest structures possessing up to four rotatable bonds, all complexes were reproduced, with guest mass-weighted root mean square deviations of <1.0 A, through docking with the NEM-generated guest local minimum conformations. An analysis of the potential energies of these local minimum conformations showed that 22 (100%, 18 (82%, 16 (73%, and 12 (55% of the 22 guest bound conformations in the crystal structures had conformational strain energies of less than or equal to 3.8, 2.0, 0.6, and 0.0 kcal/mol, respectively. These results suggest that (1 the NEM procedure can generate small-molecule bound conformations, and (2 guests adopt low-strain-energy conformations for complexation, thus supporting the virtual screening methods that use local minimum conformations.
Chen, S.; Al-Muntasheri, G.; Abousleiman, Y. N.
2014-12-01
The critical state concept based bounding surface model is one of the most widely used elastoplastic constitutive models for geomaterials, attributed mainly to its essential feature of allowing plastic deformation to occur for stress points within the bounding surface and thus the capability to represent the realistic non-recoverable behaviour of soils and rocks observed under the cyclic loading. This paper develops an implicit integration algorithm for the bounding surface model, using the standard return mapping approach (elastic predictor-plastic corrector), to obtain the updated stresses for the given strain increments. The formulation of the constitutive integration requires the derivation of a supplementary differential equation to describe the evolution of a key variable, i.e., the ratio between the image stress and the current stress quantities. It is essentially an extension of the integration scheme presented in an earlier work used for the simple bounding surface version of modified Cam Clay associated with a substantially simplified hardening rule. The integration algorithm for the bounding surface model is implemented into the finite element analysis commercial program, ABAQUS, through the material interface of UMAT (user defined material subroutine), and then used for the analysis of wellbore stability problem. The predictions from the ABAQUS simulations are generally in excellent agreement with the available analytical solutions, thus demonstrating the accuracy and robustness of the proposed integration scheme.
Tokamak advanced pump limiter experiments and analysis
International Nuclear Information System (INIS)
Experiments with pump limiter modules on several operating tokamaks establish such limiters as efficient collectors of particles and has demonstrated the importance of ballistic scattering as predicted theoretically. Plasma interaction with recycling neutral gas appears to become important as the plasma density increases and the effective ionization mean free path within the module decreases. In limiters with particle collection but without active internal pumping, the neutral gas pressure is found to vary nonlinearly with the edge plasma density at the highest densities studies. Both experiments and theory indicate that the energy spectrum of gas atoms in the pump ducting is non-thermal, consistent with the results of Monte Carlo neutral atom transport calculations. The distribution of plasma power over the front surface of such modules has been measured and appears to be consistent with the predictions of simple theory. Initial results from the latest experiment on the ISX-B tokamak with an actively pumped limiter module demonstrates that the core plasma density can be controlled with a pump limiter and that the scrape-off layer plasma can partially screen the core plasma from gas injection. The results from module pump limiter experiments and from the theory and design analysis of advanced pump limiters for reactors are used to suggest the major features of a definitive, axisymmetric, toroidal belt pump limiter experiment
Strategic analysis of International Forest Products Limited
Modesto, Robin M.
2005-01-01
International Forest Products Limited is a sawmilling company that produces softwood lumber for sale in domestic and international markets including the United States and Japan. Production facilities located in British Columbia, Washington and Oregon produce nearly 1.5 billion board feet of lumber annually. Timber is secured through Crown forest tenure holdings and external open market purchases. This paper includes: a strategic analysis of the firm; an industry analysis; a strategic fit anal...
LimitS - A system for limit state analysis and optimal material layout
DEFF Research Database (Denmark)
Damkilde, Lars; Krenk, Steen
1997-01-01
distribution or an optimal material layout is determined. Through linearization of the yield criteria the optimization problem is stated as a linear programming problem. Within the formulation of the discretized model the optimal lower-bound solution is shown to be an upper-bound solution, and thereby both...
基于自然单元法的极限上限分析%UPPER-BOUND LIMIT ANALYSES BASED ON NATURAL ELEMENT METHOD
Institute of Scientific and Technical Information of China (English)
周书涛; 刘应华; 陈莘莘
2012-01-01
The natural element method (NEM) is a novel numerical method based on voronoi diagram and delaunay triangulation of the scattered points in problem domain,and its shape function is built upon the notion of natural neighbor interpolation. Compared with the moving least square (MLS) approximation used widely in many meshless methods,natural neighbor interpolation does not involve the complex matrix inversion,needs no artificial parameter but can improve the computational efficiency. The obtained shape function satisfies the property of Kronecker delta function, and this character results in the consequence that the essential boundary condition can be easily imposed as in finite element method (FEM). Meanwhile, the problems with discontinuous field functions likewise their discontinuous derivatives can be conveniently treated. According to the kinematic theorem of plastic limit analysis,this article applies the natural element method to upper bound limit analysis. The corresponding mathematical programming formulations are established and the computational codes are implemented to solve them. Several classical examples of limit analysis are adopted to verify the performance of these codes. Furthermore,the smoothing operations are also provided to calculate plastic dissipation work on the nodes by the similar treatment of stress smoothing operation,and the contours of plastic dissipation work at the limit states are displayed. The computational results show that utilizing natural element method to solve upper bound limit analysis problems possesses the advantage of good stability,high accuracy and fast convergence.%自然单元法是一种基于离散点集的Voronoi图和Delaunay三角化几何信息,以自然邻近插值为试函数的新型数值方法.相对于一般无网格法中常采用的移动最小二乘近似而言,自然邻近插值不涉及到复杂的矩阵求逆运算,更不需要任何人为的参数,可以提高计算效率.采用该方法构造的
Numerical limit analysis of keyed shear joints in concrete structures
DEFF Research Database (Denmark)
Herfelt, Morten Andersen; Poulsen, Peter Noe; Hoang, Linh Cao;
2016-01-01
This paper concerns the shear capacity of keyed joints, which are transversely reinforced with overlapping U-bar loops. It is known from experimental studies that the discontinuity of the transverse reinforcement affects the capacity as well as the failure mode; however, to the best knowledge...... of the authors, previous theoretical works and present design equations in standards do not account for this important effect. In this paper, a detailed model based on finite element limit analysis is introduced to assess the effect of the discontinuous reinforcement. The model is based on the lower bound...... 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....
Metamaterial polarization converter analysis: limits of performance
DEFF Research Database (Denmark)
Markovich, Dmitry L.; Andryieuski, Andrei; Zalkovskij, Maksim;
2013-01-01
In this paper, we analyze the theoretical limits of a metamaterial-based converter with orthogonal linear eigenpolarizations that allow linear-to-elliptical polarization transformation with any desired ellipticity and ellipse orientation. We employ the transmission line approach providing a needed...... 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 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 design...
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%....
Pruvost, L.; Jelassi, H.; Viaris de Lesegno, B.
2009-05-01
In the context of cold molecules physics, the spectroscopic data and their analysis play a very important role. The photoassociation spectroscopy of alkali dimmers, performed by laser excitation of cold atoms, is one of the methods providing high-resolution data about the vibrational levels lying close to the dissociation limit. Such weakly bound molecules are described by the dipole-dipole interaction, i.e. -1/R^3 where R is the inter-nuclear distance and their eigen energies are close to the Le Roy-Bernstein formula [1]. The discrepancies to the formula law are due to the short-range interactions of the potential and to couplings between potentials. We have expressed the discrepancies via a parameter, the vibrational quantum defect (VQD), defined similar to the atomic quantum defect [2]. The VQD deduced from the data and plotted versus the energy allows us to emphasize the couplings. Furthermore, a fit of the graph using a 2-channel model provides the value of the coupling and a characterization of the 2 potentials. We have applied the method 5s1/2-5p1/20u+ data of Rb2 recorded in our group [3] and 6s1/2-6p1/20u+ data of Cs2 recorded in Stwalley group [4]. The coupling due to spin-orbit interaction has been deduced, the perturbing levels identified and the wavefunction mixing deduced. [1] R. J. Le Roy , R. B. Bernstein, J. Chem. Phys. 52, 3869, 1970. [2] H. Jelassi et al., Phys. Rev. A. 73, 32501, 2006. [3] H. Jelassi et al., Phys. Rev. A. 74, 12510, 2006. [4] H. Jelassi, et al., Phys. Rev. A 78, 022503, 2008.
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...
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
Impact location and load identification through inverse analysis with bounded uncertain measurements
International Nuclear Information System (INIS)
The growing demand for real-time damage assessment necessitates development of an efficient inverse analysis algorithm with consideration of practical issues such as uncertainty in measurement. A mathematical model-based inverse analysis scheme is proposed to identify impact locations and reconstruct impact load time history of a simply supported plate through multiple levels of analysis. The proximity of the impact location is first determined by the triangulation method and the impact location is then refined by minimization of an objective function through the particle swarm optimization method (PSO). Loss of data due to filtration is addressed in a further level by performing an interval analysis based on extreme measurement errors. The outcome of the analyses is a mean impact location, a load time history, and a range of likely deviations. The extreme deviation in impact location is shown by bounding lines, which form a rectangle. The deviation in load time history is also shown by upper and lower bounding sinusoidal curves. The results of the analyses indicate that the proposed method can effectively locate the impact point and reconstruct the load time history even with the existence of noise in the measured response. (paper)
Impact location and load identification through inverse analysis with bounded uncertain measurements
Ahmari, Saeed; Yang, Mijia
2013-08-01
The growing demand for real-time damage assessment necessitates development of an efficient inverse analysis algorithm with consideration of practical issues such as uncertainty in measurement. A mathematical model-based inverse analysis scheme is proposed to identify impact locations and reconstruct impact load time history of a simply supported plate through multiple levels of analysis. The proximity of the impact location is first determined by the triangulation method and the impact location is then refined by minimization of an objective function through the particle swarm optimization method (PSO). Loss of data due to filtration is addressed in a further level by performing an interval analysis based on extreme measurement errors. The outcome of the analyses is a mean impact location, a load time history, and a range of likely deviations. The extreme deviation in impact location is shown by bounding lines, which form a rectangle. The deviation in load time history is also shown by upper and lower bounding sinusoidal curves. The results of the analyses indicate that the proposed method can effectively locate the impact point and reconstruct the load time history even with the existence of noise in the measured response.
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.
Bounding flow and transport analysis of proposed 105A mock-up tank tracer test
International Nuclear Information System (INIS)
The purpose of this bounding analysis was to determine bounding estimates of salt concentrations in the aquifer below the salt-tracer plume test at the 105A mockup-tank site near the inactive Semi-Works Plant in the 200 East Area. The objective was to calculate the bounding salt concentrations and compare them to the appropriate maximum contamination level (MCL) allowed by state law, which for sodium chloride is 415 mg/l as a secondary standard. The tracer test is part of the Electrical-Resistance Tomography (ERT) demonstration, which will provide an effective method of detecting tank leaks if it is shown to be successful. The basic idea of ERT method is that the electrical resistance in the soils will change enough to be detected when water with salts infiltrate the soils, even if a high-conductance metal tank is just above the leak. The 105A mockup tank did not have an impermeable bottom and was open at the top until the time of the test. It was assumed, at the time of the tracer test or shortly afterwards, that an impermeable bottom (concrete) would be placed at the bottom of the tank, but still remain open at the top. Hence, in this analysis, no artificial recharge is produced due to water running off a tank top, since no top is assumed. The conceptual model is discussed in Section 2.0 with the mathematical and numerical models briefly discussed in Section 3.0. The main results are given in Section 4.0 with the conclusions drawn in Section 5.0. These calculations were made before the tracer test. A similar set of calculations will be performed after the tracer test assuming more details concerning leak location and soil properties are available. The tracer test could be used to validate or confirm the modeling methodology/capability of plumes in the vadose zone at the Hanford site
Energy Technology Data Exchange (ETDEWEB)
Sam, My D.; Abbani, Mohamad A.; Cascio, Duilio [Department of Chemistry and Biochemistry and the UCLA-DOE Center for Genomics and Proteomics, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095-1570 (United States); Johnson, Reid C. [Department of Biological Chemistry, UCLA School of Medicine, 10833 Le Conte Avenue, Los Angeles, CA 90095-1737 (United States); Clubb, Robert T., E-mail: rclubb@mbi.ucla.edu [Department of Chemistry and Biochemistry and the UCLA-DOE Center for Genomics and Proteomics, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095-1570 (United States)
2006-08-01
This paper describes the crystallization, dehydration and preliminary X-ray data analysis of a complex containing several bacteriophage lambda excisionase (Xis) proteins cooperatively bound to a 33-mer DNA duplex (Xis–DNA{sup X1-X2}). This paper describes the crystallization, dehydration and preliminary X-ray data analysis of a complex containing several bacteriophage lambda excisionase (Xis) [Bushman et al. (1984 ▶). Cell, 39, 699–706] proteins cooperatively bound to a 33-mer DNA duplex (Xis–DNA{sup X1-X2}). Xis is expected to recognize this regulatory element in a novel manner by cooperatively binding and distorting multiple head-to-tail orientated DNA-binding sites. Crystals of this complex belonged to space group P3{sub 1}21 or P3{sub 2}21, with unit-cell parameters a = b = 107.7, c = 73.5 Å, α = β = 90, γ = 120°. Based on the unit-cell parameters for the asymmetric unit, V{sub M} is 3.0 Å{sup 3} Da{sup −1}, which corresponds to a solvent content of ∼59%. The approaches used to crystallize the unusually long DNA fragment in the complex and the dehydration technique applied that dramatically improved the diffraction of the crystals from 10 to 2.6 Å are discussed.
PARALLEL COMPUTING FOR STATIC RESPONSE ANALYSIS OF STRUCTURES WITH UNCERTAIN-BUT-BOUNDED PARAMETERS
Institute of Scientific and Technical Information of China (English)
Zhiping Qiu; Xiaojun; Wang Xu Zhang
2008-01-01
The vertex solution for estimation on the static displacement bounds of structures with uncertain-but-bounded parameters is studied in this paper.For the linear static problem,when there are uncertain interval parameters in the stiffness matrix and the vector of applied forces,the static response may be an interval.Based on the interval operations,the interval solution obtained by the vertex solution is more accurate and more credible than other methods (such as the perturbation method).However,the vertex solution method by traditional serial computing usually needs large computational efforts,especially for large structures.In order to avoid its disadvantages of large calculation and much runtime,its parallel computing which can be used in large-scale computing is presented in this paper.Two kinds of parallel computing algorithms are proposed based on the vertex solution.The parallel computing will solve many interval problems which cannot be resolved by traditional interval analysis methods.
Foot loading characteristics of Chinese bound feet women: a comparative analysis.
Gu, Yaodong; Mei, Qichang; Fernandez, Justin; Li, Jianshe; Ren, Xuejun; Feng, Neng
2015-01-01
The custom of bound feet among Chinese women has existed for almost a century. This practice has influenced the daily life of Chinese women, especially during everyday locomotion. The primary aim of this study is to analyze the loading patterns of bound feet. Specifically, the plantar pressure and center of pressure were analyzed for peak pressure, contact area, force time integral, center of pressure displacement velocity and trajectory in the anterior-posterior direction via a comparison with normal feet. The key outcomes from this work were that the forefoot and rearfoot of bound feet bear the whole loading during stance phase. The center of pressure displacement velocity of bound feet was also greatly reduced with the shortening of trajectories. This suggests that the proprioceptive system adjusts motor function to adapt to new loading patterns while maintaining locomotive stability. A biomechanical understanding of bound feet may assist with prevention, treatment and rehabilitation of bound feet disorders. PMID:25884982
Foot loading characteristics of Chinese bound feet women: a comparative analysis.
Directory of Open Access Journals (Sweden)
Yaodong Gu
Full Text Available The custom of bound feet among Chinese women has existed for almost a century. This practice has influenced the daily life of Chinese women, especially during everyday locomotion. The primary aim of this study is to analyze the loading patterns of bound feet. Specifically, the plantar pressure and center of pressure were analyzed for peak pressure, contact area, force time integral, center of pressure displacement velocity and trajectory in the anterior-posterior direction via a comparison with normal feet. The key outcomes from this work were that the forefoot and rearfoot of bound feet bear the whole loading during stance phase. The center of pressure displacement velocity of bound feet was also greatly reduced with the shortening of trajectories. This suggests that the proprioceptive system adjusts motor function to adapt to new loading patterns while maintaining locomotive stability. A biomechanical understanding of bound feet may assist with prevention, treatment and rehabilitation of bound feet disorders.
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.
Fanciullino, Raphaelle; Ciccolini, Joseph; Milano, Gérard
2013-12-01
Improving the efficacy-toxicity balance of anticancer agents remains an ongoing challenge in oncology. Beside the ever-growing development of innovative drugs addressing newly discovered molecular targets, nanotechnologies provide today a promising and exciting strategy to achieve this goal. The idea of carrying active compounds to their respective targets so as to improve their efficacy while sparing healthy tissue and reducing side-effects is not new. However, this area of research is in constant rise, and benefits from the latest advances in the field of biopharmaceutics, medicinal chemistry and nanomedicine. In addition to anthracyclines already widely present as liposomal drugs on the shelves, a variety of anticancer drugs can be now encapsulated into different chemical of structures so as to enhance their specificity toward malignant cells, mainly through improved pharmacokinetics profiles. Indeed, the recent advances in chemistry allow now a wide variety of scaffolds to be used as drug-carriers, so as optimize the delivery of cytotoxics. Even more recently, conjugated-drugs such as nanoalbumin (Nab) conjugates have emerged as a new promising alternative to improve both anticancer drugs distribution in the body and efficacy/toxicity balance eventually. This review covers the achievements and current limits of nanoparticles in oncology, with a special focus on nab-paclitaxel as a paradigmatic drug for this new generation of conjugated entities.
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.
Energy Technology Data Exchange (ETDEWEB)
Nichols, D.F.
1994-09-01
A detailed collisionless sheath theory and a three-region collisional model of a bounded plasma are presented, and the suitability of the collisional model for analysis of ignited mode thermionic converters is investigated. The sheath theory extends previous analyses to regimes in which the sheath potential and electron temperatures are comparable in magnitude. In all operating regimes typical of a ignited mode thermionic converter, the predicted sheaths extend several mean-free paths. The apparent collisionality of the sheaths prompted development of a collisional, three-region model of the converter plasma. By interfacing Particle-in-Cell regions (for the sheaths) and fluid regions (for the bulk of the plasma), a time-dependent, wall-to-wall model of the plasma in the inter-electrode space is created. The components of the model are tested and validated against analytic solutions and against one another, then applied to the analysis of an ignited mode thermionic converter. Under ignited mode operating conditions, the electron velocity distribution at the plasma/sheath boundary is found to be inconsistent with that assumed in the model development, and the calculation diverges. The observed distribution is analyzed and a new basis set of distribution functions is suggested that should permit application of the hybrid model to ignited mode thermionic converters.
An Analysis on Limit Load for Corroded Submarine Pipelines
Institute of Scientific and Technical Information of China (English)
TAN Kai-ren; XIAO Xi
2006-01-01
By means of elastic-plastic finite element analysis, a systematic nonlinear analysis of material and geometry has been carried out for submarine pipelines. A criterion for deriving limit load is studied. Based on this criterion, the limit load for corroded submarine pipelines is calculated. The corrosion length, corrosion depth and corrosion width affect the limit load. A solution to limit load is proposed and proved valid through comparison of the solution with burst test results and ASME B31G solutions.
Bound entanglement and entanglement bounds
Energy Technology Data Exchange (ETDEWEB)
Sauer, Simeon [Physikalisch-Astronomische Fakultaet, Friedrich-Schiller-Univesitaet Jena (Germany)]|[Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg (Germany); Melo, Fernando de; Mintert, Florian; Buchleitner, Andreas [Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg (Germany)]|[Max-Planck-Institut fuer Physik komplexer Systeme, Noethnitzer Str.38, D-01187 Dresden (Germany); Bae, Joonwoo [School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-012 (Korea); Hiesmayr, Beatrix [Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna (Austria)
2008-07-01
We investigate the separability of Bell-diagonal states of two qutrits. By using lower bounds to algebraically estimate concurrence, we find convex regions of bound entangled states. Some of these regions exactly coincide with the obtained results when employing optimal entanglement witnesses, what shows that the lower bound can serve as a precise detector of entanglement. Some hitherto unknown regions of bound entangled states were discovered with this approach, and delimited efficiently.
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 ...
Physical Uncertainty Bounds (PUB)
Energy Technology Data Exchange (ETDEWEB)
Vaughan, Diane Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Dean L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-03-19
This paper introduces and motivates the need for a new methodology for determining upper bounds on the uncertainties in simulations of engineered systems due to limited fidelity in the composite continuum-level physics models needed to simulate the systems. We show that traditional uncertainty quantification methods provide, at best, a lower bound on this uncertainty. We propose to obtain bounds on the simulation uncertainties by first determining bounds on the physical quantities or processes relevant to system performance. By bounding these physics processes, as opposed to carrying out statistical analyses of the parameter sets of specific physics models or simply switching out the available physics models, one can obtain upper bounds on the uncertainties in simulated quantities of interest.
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...
Foot Loading Characteristics of Chinese Bound Feet Women: A Comparative Analysis
Yaodong Gu; Qichang Mei; Justin Fernandez; Jianshe Li; Xuejun Ren; Neng Feng
2015-01-01
The custom of bound feet among Chinese women has existed for almost a century. This practice has influenced the daily life of Chinese women, especially during everyday locomotion. The primary aim of this study is to analyze the loading patterns of bound feet. Specifically, the plantar pressure and center of pressure were analyzed for peak pressure, contact area, force time integral, center of pressure displacement velocity and trajectory in the anterior-posterior direction via a comparison wi...
Detection limits in x-ray fluorescence analysis
International Nuclear Information System (INIS)
X-ray fluorescence spectrometry is a well established analytical technique for elemental analysis of solids, powders, or liquids. This extended abstract briefly discusses the detection limits or sensitivity of x-ray spectrometers in x-ray fluorescence analysis
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...
Faydasicok, Ozlem; Arik, Sabri
2013-08-01
The main problem with the analysis of robust stability of neural networks is to find the upper bound norm for the intervalized interconnection matrices of neural networks. In the previous literature, the major three upper bound norms for the intervalized interconnection matrices have been reported and they have been successfully applied to derive new sufficient conditions for robust stability of delayed neural networks. One of the main contributions of this paper will be the derivation of a new upper bound for the norm of the intervalized interconnection matrices of neural networks. Then, by exploiting this new upper bound norm of interval matrices and using stability theory of Lyapunov functionals and the theory of homomorphic mapping, we will obtain new sufficient conditions for the existence, uniqueness and global asymptotic stability of the equilibrium point for the class of neural networks with discrete time delays under parameter uncertainties and with respect to continuous and slope-bounded activation functions. The results obtained in this paper will be shown to be new and they can be considered alternative results to previously published corresponding results. We also give some illustrative and comparative numerical examples to demonstrate the effectiveness and applicability of the proposed robust stability condition.
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.
土石坝坡极限抗震能力的下限有限元法%Lower bound FEM for limit aseismic capability of earth-rockfill dams
Institute of Scientific and Technical Information of China (English)
杨昕光; 迟世春
2013-01-01
基于极限分析下限定理,假设材料严格服从Mohr-Coulomb屈服准则,同时考虑了堆石料内摩擦角较大以及抗剪强度具有非线性的特性,提出了一个用于求解土石坝坝坡极限抗震能力的有限元计算方法.该方法通过静力平衡条件、应力间断面连续条件、边界条件、屈服条件以及所求极限荷载,形成标准的二次锥规划数学模型,并用内点法进行优化迭代求解,得到土石坝坡极限抗震能力的下限值.对一条形基础地基承载力进行下限极限分析,通过与已有计算结果比较表明所提方法的具有很高的计算精度.运用所提方法对一典型心墙土石坝进行抗震极限分析,其计算结果符合土石坝坡在地震作用下的一般破坏规律,证明此方法具有很高的实用价值.%An FEM basea on the lower bound theorem of limit analysis is proposed to study the limit aseismic capability of earth-rock-fill dams.Considering the large internal friction angel and non-linear shear strength parameters of rockfill materials,the proposed method formulates the limit analysis as a second-order cone programming (SOCP) problem with constraints based on the conditions of equilibrium,stress discontinuity,stress boundary and native Mohr-Coulomb yield criterion.The lower bound of the limit aseismic capability is then obtained by means of the interior-point algorithm and the iterative approach.Comparison with the published solutions illustrates the correctness and effectiveness of the proposed method for a smooth strip footing problem.The proposed approach is also applied to the seismic stability analysis of a typical rockfill dam with core wall so that the limit aseismic capability of the dam is obtained.The results proclaim the seismic failure mechanisms of earth-rockfill dams and demonstrate the practical value of the proposed method.
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...
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}(\\...
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).
International Nuclear Information System (INIS)
Nuclear forces play a decisive role to account for the evolution of the nuclear structure and to fix the limits of particle stability. The study of neutron-rich nuclei is particularly important to determine these limits and to reveal the disappearance or emergence of new shell gaps far from stability. We studied the weakly bound neutron-rich 26F in order to probe the πd5/2xνd3/2 interaction. Indeed this nucleus can be modeled as a closed core of 24O on top of which a single deeply bound proton in πd5/2 interacts with an unbound neutron in νd3/2. This coupling gives rise to the quadruplet of states J = 1, 2, 3, 4 of positive parity. Their determination would allow us to quantify the intensity of the πd5/2xνd3/2 interaction. Among these states, the J = 1 (ground state) and J = 2 (first excited state) were already known. The search for the J = 4 state has been investigated by our group at GANIL through a β-decay experiment. The nuclei of 26F were produced by the fragmentation of a 36S beam and selected using the LISE spectrometer. They were then implanted in a Double Sided Stripped Silicon Detector that gave us the opportunity to achieve spatial and time correlations between the implanted ions and the products of the decays (β and γ rays). Moreover we were able to observe the delayed M3 γ transition from the isomeric J = 4 state to the J = 1 ground state and thus obtained the excitation energy of 643.4 keV for this isomeric state. We also determined several new states in 25-26Ne that were fed by the β-decay of the ground and isomeric state of 26F. We extracted an isomeric ratio of about 40% and adjusted the previously determined mass of 26F according to this value, leading to ΔM = 270 (50) keV. The J = 3 state has been populated ad studied at GSI by means of a one proton knock-out reaction from a radioactive 27Ne beam to produce the 26F in its unbound states. When the 26F is produced in its unbound state J = 3, it decays in 25F + n. The ions were tracked
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...
Energy Technology Data Exchange (ETDEWEB)
Kellers, Petra; Ogata, Hideaki; Lubitz, Wolfgang, E-mail: lubitz@mpi-muelheim.mpg.de [Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr (Germany)
2008-08-01
This article describes the first successful crystallization of a membrane-bound [NiFe] hydrogenase isolated from a photosynthetic organism (A. vinosum). The crystals obtained produced diffraction patterns up to 2.5 Å resolution. The membrane-bound [NiFe] hydrogenase is a unique metalloprotein that is able to catalyze the reversible oxidation of hydrogen to protons and electrons during a complex reaction cycle. The [NiFe] hydrogenase was isolated from the photosynthetic purple sulfur bacterium Allochromatium vinosum and its crystallization and preliminary X-ray analysis are reported. It was crystallized by the hanging-drop vapour-diffusion method using sodium citrate and imidazole as crystallization agents. The crystals belong to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 205.00, b = 217.42, c = 120.44 Å. X-ray diffraction data have been collected to 2.5 Å resolution.
Methods of fault tree analysis and their limits
International Nuclear Information System (INIS)
Some recent methodological developments of fault tree analysis are discussed and limits of fault tree analysis and a criterion for admissibility of structure functions are given. It is shown that there are interesting relations to switching theory and to stochastic processes. (orig./HP)
UPPER-BOUND APPROACH ANALYSIS OF DRIVING POWER OF WHEEL FOR CASTEX
Institute of Scientific and Technical Information of China (English)
无
1999-01-01
CASTEX(Cast Extruding) is a relatively new process in the metal working and a further improvement of the CONFORM(Continuous Extrusion Forming) process with feedstock changing into molten metal instead of granular feedstock or rod. A deformation zone division has been made and a driving power formula of wheel groove has been established by applying the Upper-Bound Theorem to the CASTEX process. It is shown by experiment and calculation that the calculated results are in agreement with the experimental ones.
Financial frictions and the zero lower bound on interest rates: a DSGE analysis
Merola, Rossana
2010-01-01
Recent developments in Canada, the United Kingdom, the euro area, Japan, Sweden, Switzerland and the United States have triggered a debate on whether monetary policy is effective when the nominal interest rate is close to zero. In this context, the monetary authority is no longer in a position to pursue a policy of monetary easing by lowering nominal interest rates further. However, some economists have down-played the risk of hitting the zero lower bound, at least for the US economy. In t...
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...
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...
Macro economic analysis of CO2 emission limits for China
International Nuclear Information System (INIS)
Using a newly developed time-recursive dynamic CGE model for energy and environmental policy analysis of the Chinese economy, a business-as-usual scenario is first developed assuming no specific policy intervention to limit the growth rate of CO2 emissions. Counter factual policy simulation is then carried out to compute the macroeconomic implications of a carbon tax to limit the Chinese energy-related CO2 emissions. 2 tabs., 5 refs
Energy Technology Data Exchange (ETDEWEB)
De Leo, Stefano [Department of Applied Mathematics, University of Campinas, PO Box 6065, SP 13083-970, Campinas (Brazil); Ducati, Gisele C [Department of Mathematics, University of Parana PO Box 19081, PR 81531-970, Curitiba (Brazil)
2005-04-15
We study the bound-state solutions of vanishing angular momentum in a quaternionic spherical square-well potential of finite depth. As in standard quantum mechanics, such solutions occur for discrete values of energy. At first glance, it seems that the continuity conditions impose a very restrictive constraint on the energy eigenvalues and, consequently, no bound states were expected for energy values below the pure quaternionic potential. Nevertheless, a careful analysis shows that pure quaternionic potentials do not remove bound states. It is also interesting to compare these new solutions with the bound state solutions of the trial-complex potential. The study presented in this paper represents a preliminary step towards a full understanding of the role that quaternionic potentials could play in quantum mechanics. Of particular interest for the authors is the analysis of confined wave packets and tunnelling times in this new formulation of quantum theory.
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.
Goal programming with bounded variables and post analysis%有界变量目标规划及后分析
Institute of Scientific and Technical Information of China (English)
胡清淮; 魏一鸣
2003-01-01
This paper outlines the algorithm of linear goal programming with bounded variables and its post analysis. An application of this method for selection of a preferable solution within the multiple solutions is demonstrated.
NONSMOOTH MODEL FOR PLASTIC LIMIT ANALYSIS AND ITS SMOOTHING ALGORITHM
Institute of Scientific and Technical Information of China (English)
LI Jian-yu; PAN Shao-hua; LI Xing-si
2006-01-01
By means of Lagrange duality theory of the convex program, a dual problem of Hill's maximum plastic work principle under Mises' yield condition has been derived and whereby a non-differentiable convex optimization model for the limit analysis is developed. With this model, it is not necessary to linearize the yield condition and its discrete form becomes a minimization problem of the sum of Euclidean norms subject to linear constraints. Aimed at resolving the non-differentiability of Euclidean norms, a smoothing algorithm for the limit analysis of perfect-plastic continuum media is proposed.Its efficiency is demonstrated by computing the limit load factor and the collapse state for some plane stress and plain strain problems.
Directory of Open Access Journals (Sweden)
Lin Hung-Pin
2014-01-01
Full Text Available The purpose of this paper is to investigate the short-run and long-run causality between renewable energy (RE consumption and economic growth (EG in nine OECD countries from the period between 1982 and 2011. To examine the linkage, this paper uses the autoregressive distributed lag (ARDL bounds testing approach of cointegration test and vector error-correction models to test the causal relationship between variables. The co-integration and causal relationships are found in five countries—United States of America (USA, Japan, Germany, Italy, and United Kingdom (UK. The overall results indicate that (1 a short-run unidirectional causality runs from EG to RE in Italy and UK; (2 long-run unidirectional causalities run from RE to EG for Germany, Italy, and UK; (3 a long-run unidirectional causality runs from EG to RE in USA, and Japan; (4 both long-run and strong unidirectional causalities run from RE to EG for Germany and UK; and (5 Finally, both long-run and strong unidirectional causalities run from EG to RE in only USA. Further evidence reveals that policies for renewable energy conservation may have no impact on economic growth in France, Denmark, Portugal, and Spain.
Hung-Pin, Lin
2014-01-01
The purpose of this paper is to investigate the short-run and long-run causality between renewable energy (RE) consumption and economic growth (EG) in nine OECD countries from the period between 1982 and 2011. To examine the linkage, this paper uses the autoregressive distributed lag (ARDL) bounds testing approach of cointegration test and vector error-correction models to test the causal relationship between variables. The co-integration and causal relationships are found in five countries-United States of America (USA), Japan, Germany, Italy, and United Kingdom (UK). The overall results indicate that (1) a short-run unidirectional causality runs from EG to RE in Italy and UK; (2) long-run unidirectional causalities run from RE to EG for Germany, Italy, and UK; (3) a long-run unidirectional causality runs from EG to RE in USA, and Japan; (4) both long-run and strong unidirectional causalities run from RE to EG for Germany and UK; and (5) Finally, both long-run and strong unidirectional causalities run from EG to RE in only USA. Further evidence reveals that policies for renewable energy conservation may have no impact on economic growth in France, Denmark, Portugal, and Spain.
DEFF Research Database (Denmark)
Forchhammer, Søren
2004-01-01
A method for designing quasistationary probability measures for two-dimensional (2-D) constraints is presented. This measure is derived from a modified bit-stuff coding scheme and it gives the capacity of the coding scheme. This provides a constructive lower bound on the capacity of the 2-D...... constraint. The main examples are checkerboard codes with binary elements. The capacity for one instance of the modified bit-stuffing for the 2-D runlength-limited RLL(2,∞) constraint is calculated to be 0.4414 bits/symbol. For the constraint given by a minimum (1-norm) distance of 3 between 1s a code with...... capacity 0.3497 bits/symbol is given....
Breakdown voltage analysis of field limiting ring structure
International Nuclear Information System (INIS)
In this paper, a computer based analysis is performed to study the effect of floating field-limiting rings (FLR) on the breakdown voltage of Si microstrip detectors. For optimum performance it is crucial to achieve the maximum breakdown voltage for Si detectors operated at very high bias due to extremely hostile radiation environment of LHC. The breakdown performance of Si microstrip detectors can be improved by implementing floating field-limiting rings (FLR) around the active detector area. In the present work, we propose a criterion for optimising the spacing of FLR with respect to the main junction. (author)
Directory of Open Access Journals (Sweden)
Bekkai Messirdi
2015-03-01
Full Text Available Let X and Y two complex Banach spaces and (A,B a pair of bounded linear operators acting on X with value on Y. This paper is concerned with spectral analysis ofthe pair (A;B: We establish some properties concerning the spectrum of the linear operator pencils (A-lambda B when B is not necessarily invertible and lambda is a complex number. Also, we use the functional calculus for the pair (A,B to prove the corresponding spectral mapping theorem for (A,B. In addition, we define the generalized Kato essential spectrum and the closed range spectra of the pair (A,B and we give some relationships between this spectrums. As application, we describe a spectral analysis of quotient operators.
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...
Relationship Network Analysis of Manufacturing System Limited by Business Lines
Directory of Open Access Journals (Sweden)
CHEN Guorong
2012-10-01
Full Text Available It is a common problem of manufacturing enterprise limited by business line, which optimized its resources allocation to increase productivity, but now the researches are very weak in relationship mapping and network analysis method in the world. Aimed to the demands, proposed a resource allocation method limited by business line of manufacturing system based on the relational mapping of production system, manufacturing model of hierarchical network based on business line and node degree are been established. Defined the data structure of node on hierarchical network, simplified the network computing by dividing it to three parts - orders assignment, accomplish feedback and pure information exchange. Analyzed the distributing of network degree, established an equation of power law which has two limited parameters of node degree and side weight to automatic compute the amounts of resources of new order. Case study shows that the network analysis method limited business line proposed in the paper can give us an important reference frame of resources assignment.
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...
Time series analysis in astronomy: Limits and potentialities
DEFF Research Database (Denmark)
Vio, R.; Kristensen, N.R.; Madsen, Henrik;
2005-01-01
In this paper we consider the problem of the limits concerning the physical information that can be extracted from the analysis of one or more time series ( light curves) typical of astrophysical objects. On the basis of theoretical considerations and numerical simulations, we show that with no a......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 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 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...
Cramér-Rao lower bound analysis for guidance systems with bearings-only measurements
Institute of Scientific and Technical Information of China (English)
ZHANG Yong-an; ZHOU Di; DUAN Guang-ren
2007-01-01
Most currently existing investigations on the observability of passive guidance systems can only protimability analysis of closed-loop guidance systems with bearings-only measurements, is proposed. The new method provides an intuitive result for observability of the guidance system through graphical analysis. As a demonstration, a numerical example is presented, in which the degrees of observability of the guidance systems under two commonly used guidance laws are compared by using the new approach.
TFCX pumped limiter and vacuum pumping system design and analysis
International Nuclear Information System (INIS)
Impurity control system design and performance studies were performed in support of the Tokamak Fusion Core Experiment (TFCX) pre-conceptual design. Efforts concentrated on pumped limiter and vacuum pumping system design configuration, thermal/mechanical and erosion lifetime performance of the limiter protective surface, and helium ash removal performance. The reference limiter design forms a continuous toroidal belt at the bottom of the device and features a flat surface with a single leading edge. The vacuum pumping system features large vacuum ducts (diameter approximately 1 m) and high-speed, compound cryopumps. Analysis results indicate that the limiter/vacuum pumping system design provides adequate helium ash removal. Erosion, primarily by disruption-induced vaporization and/or melting, limits the protective surface lifetime to about one calendar year or only about 60 full-power hours of operation. In addition to evaluating impurity control system performance for nominal TFCX conditions, these studies attempt to focus on the key plasma physics and engineering design issues that should be addressed in future research and development programs
Directory of Open Access Journals (Sweden)
LiuWei Zhao
2016-01-01
Full Text Available A dynamic multimarket Cournot model is introduced based on a specific inverse demand function. Puu’s incomplete information approach, as a realistic method, is used to contract the corresponding dynamical model under this function. Therefore, some stability analysis is carried out on the model to detect the stability and instability conditions of the system’s Nash equilibrium. Based on the analysis, some dynamic phenomena such as bifurcation and chaos are found. Numerical simulations are used to provide experimental evidence for the complicated behaviors of the system evolution. It is observed that the equilibrium of the system can lose stability via flip bifurcation or Neimark-Sacker bifurcation and time-delayed feedback control is used to stabilize the chaotic behaviors of the system.
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...
Limit analysis on FRP-strengthened RC members
Directory of Open Access Journals (Sweden)
D. De Domenico
2014-07-01
Full Text Available Reinforced concrete (RC members strengthened with externally bonded fiber-reinforced-polymer (FRP plates are numerically investigated by a plasticity-based limit analysis approach. The key-concept of the present approach is to adopt proper constitutive models for concrete, steel reinforcement bars (re-bars and FRP strengthening plates according to a multi-yield-criteria formulation. This allows the prediction of concrete crushing, steel bars yielding and FRP rupture that may occur at the ultimate limit state. To simulate such limitstate of the analysed elements, two iterative methods performing linear elastic analyses with adaptive elastic parameters and finite elements (FEs description are employed. The peak loads and collapse mechanisms predicted for FRP-plated RC beams are validated by comparison with the corresponding experimental findings.
Pallan, Pradeep S; Prakash, Thazha P; de Leon, Arnie R; Egli, Martin
2016-09-27
RNase H1 cleaves the RNA strand of RNA:DNA hybrids. Replacement of RNA 2'-hydroxyls by fluorine (FRNA) is commonly used to stabilize aptamers and siRNAs. However, FRNA:DNA hybrids fail to elicit RNase H activity. The underlying reasons are unclear, as 2'-OH groups are not directly involved in cleavage. We determined the crystal structure of Bacillus halodurans RNase H bound to a FRNA:DNA hybrid. The structure points to dynamic (slippage of the FRNA:DNA hybrid relative to the enzyme), geometric (different curvatures of FRNA:DNA and RNA:DNA hybrids), and electronic reasons (Mg(2+) absent from the active site of the FRNA:DNA complex) for the loss of RNaseH activity.
Directory of Open Access Journals (Sweden)
Ballester Pla, Coralio
2012-03-01
Full Text Available The observation of the actual behavior by economic decision makers in the lab and in the field justifies that bounded rationality has been a generally accepted assumption in many socio-economic models. The goal of this paper is to illustrate the difficulties involved in providing a correct definition of what a rational (or irrational agent is. In this paper we describe two frameworks that employ different approaches for analyzing bounded rationality. The first is a spatial segregation set-up that encompasses two optimization methodologies: backward induction and forward induction. The main result is that, even under the same state of knowledge, rational and non-rational agents may match their actions. The second framework elaborates on the relationship between irrationality and informational restrictions. We use the beauty contest (Nagel, 1995 as a device to explain this relationship.
La observación del comportamiento de los agentes económicos tanto en el laboratorio como en la vida real justifica que la racionalidad acotada sea un supuesto aceptado en numerosos modelos socio-económicos. El objetivo de este artículo es ilustrar las dificultades que conlleva una correcta definición de qué es un agente racional (irracional. En este artículo se describen dos marcos que emplean diferentes metodologías para analizar la racionalidad acotada. El primero es un modelo de segregación espacial donde se contrastan dos metodologías de optimización: inducción hacia atrás y hacia adelante. El resultado principal es que, incluso con el mismo nivel de conocimiento, tanto agentes racionales como irracionales podrían coincidir en sus acciones. El segundo marco trabaja sobre la relación entre irracionalidad y restricción de información. Se utiliza el juego llamado “beauty contest” (Nagel 1995 como mecanismo para explicar dicha relación.
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
International Nuclear Information System (INIS)
The static method for the evaluation of the limit loads of a perfectly elasto-plastic structure is presented. Using the static theorem of Limit Analysis and the Finite Element Method, a lower bound for the colapso load can be obtained through a linear programming problem. This formulation if then applied to symmetrically loaded shells of revolution and some numerical results of limit loads in nozzles are also presented. (Author)
Roof collapse of shallow tunnels with limit analysis method
Institute of Scientific and Technical Information of China (English)
YANG Xiao-li; LONG Ze-xiang
2015-01-01
A new failure mechanism is proposed to analyze the roof collapse based on nonlinear failure criterion. Limit analysis approach and variational principle are used to obtain analytical findings concerning the stability of potential roof. Then, parametric study is carried out to derive the change rule of corresponding parameters on the influence of collapsing shape, which is of paramount engineering significance to instruct the tunnel excavations. In comparison with existing results, the findings show agreement and validity of the proposed method. The actual collapse in certain shallow tunnels is well in accordance with the proposed failure mechanism.
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.
Multi-criteria decision analysis: Limitations, pitfalls, and practical difficulties
Energy Technology Data Exchange (ETDEWEB)
Kujawski, Edouard
2003-02-01
The 2002 Winter Olympics women's figure skating competition is used as a case study to illustrate some of the limitations, pitfalls, and practical difficulties of Multi-Criteria Decision Analysis (MCDA). The paper compares several widely used models for synthesizing the multiple attributes into a single aggregate value. The various MCDA models can provide conflicting rankings of the alternatives for a common set of information even under states of certainty. Analysts involved in MCDA need to deal with the following challenging tasks: (1) selecting an appropriate analysis method, and (2) properly interpreting the results. An additional trap is the availability of software tools that implement specific MCDA models that can beguile the user with quantitative scores. These conclusions are independent of the decision domain and they should help foster better MCDA practices in many fields including systems engineering trade studies.
Membrane-bound electron transport systems of an anammox bacterium: A complexome analysis.
de Almeida, Naomi M; Wessels, Hans J C T; de Graaf, Rob M; Ferousi, Christina; Jetten, Mike S M; Keltjens, Jan T; Kartal, Boran
2016-10-01
Electron transport, or oxidative phosphorylation, is one of the hallmarks of life. To this end, prokaryotes evolved a vast variety of protein complexes, only a small part of which have been discovered and studied. These protein complexes allow them to occupy virtually every ecological niche on Earth. Here, we applied the method of proteomics-based complexome profiling to get a better understanding of the electron transport systems of the anaerobic ammonium-oxidizing (anammox) bacteria, the N2-producing key players of the global nitrogen cycle. By this method nearly all respiratory complexes that were previously predicted from genome analysis to be involved in energy and cell carbon fixation were validated. More importantly, new and unexpected ones were discovered. We believe that complexome profiling in concert with (meta)genomics offers great opportunities to expand our knowledge on bacterial respiratory processes at a rapid and massive pace, in particular in new and thus far poorly investigated non-model and environmentally-relevant species. PMID:27461995
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 nature and limits of interactive communication: A philosophical analysis
Directory of Open Access Journals (Sweden)
Halvor Nordby
2011-04-01
Full Text Available In many modern study programs, teachers and students communicate via internet and other interactive communicative channels. What is the essential nature of this communication? How does interactive communication differ from ordinary face-to-face communication in the most fundamental sense? The article uses conceptual analysis as a philosophical method to explore the intrinsic nature of the concept interactive communication. The aim of this method is to develop a concept definition that matches shared linguistic beliefs about informative examples from internet based communication and information exchange that is central in electronic teaching courses. The article examines several concept definitions and argues in favor of a philosophical information processing analysis of interactive communication. The significance of this analysis has two dimensions. First, it can give teachers and others who are involved in interactive communication a better understanding of the essential differences between interactive and face-toface communication. Second, the analysis can stimulate pedagogical and critical reflection on the nature and limits of internet based communication and electronic teaching tools.
New results in the limit analysis by secondary modified creep
International Nuclear Information System (INIS)
Two methods for computing upper and lower bounds of colapse loads are proposed by means of generalized creep constitutive relations. The actual material behaviour is rigid-perfectly plastic and the techniques here analized consist in the substitution of this material by a fictitious one which presents steady state creep response. Some analytical examples are also presented. (Author)
Directory of Open Access Journals (Sweden)
Susanne Fanghänel
Full Text Available Structure analysis of the cell-penetrating peptide transportan 10 (TP10 revealed an exemplary range of different conformations in the membrane-bound state. The bipartite peptide (derived N-terminally from galanin and C-terminally from mastoparan was found to exhibit prominent characteristics of (i amphiphilic α-helices, (ii intrinsically disordered peptides, as well as (iii β-pleated amyloid fibrils, and these conformational states become interconverted as a function of concentration. We used a complementary approach of solid-state (19F-NMR and circular dichroism in oriented membrane samples to characterize the structural and dynamical behaviour of TP10 in its monomeric and aggregated forms. Nine different positions in the peptide were selectively substituted with either the L- or D-enantiomer of 3-(trifluoromethyl-bicyclopent-[1.1.1]-1-ylglycine (CF3-Bpg as a reporter group for (19F-NMR. Using the L-epimeric analogs, a comprehensive three-dimensional structure analysis was carried out in lipid bilayers at low peptide concentration, where TP10 is monomeric. While the N-terminal region is flexible and intrinsically unstructured within the plane of the lipid bilayer, the C-terminal α-helix is embedded in the membrane with an oblique tilt angle of ∼ 55° and in accordance with its amphiphilic profile. Incorporation of the sterically obstructive D-CF3-Bpg reporter group into the helical region leads to a local unfolding of the membrane-bound peptide. At high concentration, these helix-destabilizing C-terminal substitutions promote aggregation into immobile β-sheets, which resemble amyloid fibrils. On the other hand, the obstructive D-CF3-Bpg substitutions can be accommodated in the flexible N-terminus of TP10 where they do not promote aggregation at high concentration. The cross-talk between the two regions of TP10 thus exerts a delicate balance on its conformational switch, as the presence of the α-helix counteracts the tendency of the
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.
Directory of Open Access Journals (Sweden)
Ephraim S. Gower
2014-12-01
Full Text Available In this study, a generic analysis of sensor impulse response effects on linearly filtered channel noise is presented to illustrate the resulting variations to the Cramèr–Rao lower bounds (CRLBs of signal parameter estimators in signal processing and communication applications. The authors start by deriving the density function of a filtered signal, which is shown to be a mixture density, and hence the exact expressions for the mean and variance. Simulation results are used to confirm the derivations, which are then used to investigate the effects of impulse response length and variance, as well as channel noise length and variance effects on the resulting CRLBs. Results indicate that for non-zero-mean channel noise and impulse responses, the resulting mean of filtered noise can be relatively large causing adverse deviations to parameter estimations. The filtered noise variance is shown to be proportional to the impulse response energy, where for long duration of signal capture the CRLB is significantly increased.
Cousins, Robert D
2011-01-01
Suppose an observable x is the measured value (negative or non-negative) of a true mean mu (physically non-negative) in an experiment with a Gaussian resolution function with known fixed rms deviation s. The most powerful one-sided upper confidence limit at 95% C.L. is UL = x+1.64s, which I refer to as the "original diagonal line". Perceived problems in HEP with small or non-physical upper limits for x<0 historically led, for example, to substitution of max(0,x) for x, and eventually to abandonment in the Particle Data Group's Review of Particle Physics of this diagonal line relationship between UL and x. Recently Cowan, Cranmer, Gross, and Vitells (CCGV) have advocated a concept of "power constraint" that when applied to this problem yields variants of diagonal line, including UL = max(-1,x)+1.64s. Thus it is timely to consider again what is problematic about the original diagonal line, and whether or not modifications cure these defects. In a 2002 Comment, statistician Leon Jay Gleser pointed to the lite...
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.
Andrade, Daniel
2012-01-01
We present a new method to propagate lower bounds on conditional probability distributions in conventional Bayesian networks. Our method guarantees to provide outer approximations of the exact lower bounds. A key advantage is that we can use any available algorithms and tools for Bayesian networks in order to represent and infer lower bounds. This new method yields results that are provable exact for trees with binary variables, and results which are competitive to existing approximations in credal networks for all other network structures. Our method is not limited to a specific kind of network structure. Basically, it is also not restricted to a specific kind of inference, but we restrict our analysis to prognostic inference in this article. The computational complexity is superior to that of other existing approaches.
Limitations in simulator time-based human reliability analysis methods
International Nuclear Information System (INIS)
Developments in human reliability analysis (HRA) methods have evolved slowly. Current methods are little changed from those of almost a decade ago, particularly in the use of time-reliability relationships. While these methods were suitable as an interim step, the time (and the need) has come to specify the next evolution of HRA methods. As with any performance-oriented data source, power plant simulator data have no direct connection to HRA models. Errors reported in data are normal deficiencies observed in human performance; failures are events modeled in probabilistic risk assessments (PRAs). Not all errors cause failures; not all failures are caused by errors. Second, the times at which actions are taken provide no measure of the likelihood of failures to act correctly within an accident scenario. Inferences can be made about human reliability, but they must be made with great care. Specific limitations are discussed. Simulator performance data are useful in providing qualitative evidence of the variety of error types and their potential influences on operating systems. More work is required to combine recent developments in the psychology of error with the qualitative data collected at stimulators. Until data become openly available, however, such an advance will not be practical
International Nuclear Information System (INIS)
Tritium in the UK environment causes low radiation doses to the public, but uncertainty exists in the dose coefficient for the organically-bound component of tritium (OBT). This can affect the assessment of effective doses to representative persons. Contributing to that uncertainty is poor knowledge of the body retention time of OBT and how this varies for different OBT compounds in food. This study was undertaken to measure the retention time of tritium by volunteers after eating sole from Cardiff Bay, which may contain OBT from discharges from the GE Healthcare Ltd. plant. Five volunteers provided samples of excreta over periods up to 150 days after intake. Preliminary analysis of the results suggests retention of total tritium with body half-times ranging from 4 to 11 days, with no evidence of a significant contribution due to retention with a longer half-time. This range covers the half-time of 10 days used by the ICRP for tritiated water. The short timescale could be due to rapid hydrolysis in body tissues of the particular form of OBT used in this study. Implications for the dose coefficient for OBT are that the use of the ICRP value of 4.2 10-11 Sv Bq-1 may be cautious in this specific situation, and the value of 1.6 10-11 Sv Bq-1 used by the ICRP for tritiated water might even be more appropriate. These observations on dose coefficients are separate from any implications of recent discussion on whether the tritium radiation weighting factor should be increased from 1 to 2. (author)
Michelson, K.; Sanford, R. A.; Valocchi, A. J.; Werth, C. J.
2015-12-01
Microbial reduction of metals and radionuclides in the subsurface plays an essential role in the biogeochemical cycling of micronutrients and the remediation of contaminated groundwater. While recent advances in the field have improved our ability to understand and predict bioreduction in these environments, the contribution of long-range extracellular electron transfer (EET) by electron shuttling or reduction along conductive pili remains elusive. Long-range EET is implicated in the reduction of radionuclides like uranium that are reversibly sorbed in clay nanopores and exist as persistant sources of contamination. In regions of low hydraulic conductivity, electron shuttles and conductive pili may increase physical mixing beyond what is possible by advection and diffusion, resulting in reduction over a larger area than predicted by current models. We present a novel microfluidic platform that allows us to study long-range EET to the exclusion of other mechanisms, directly observe these phenomena under a controlled environment representative of groundwater conditions, monitor the metabolic activity and redox state of bacteria, and determine the presence of reduced products in-situ. Using Geobacter sulfurreducens as a model metal-reducing bacteria, insoluble manganese dioxide as an electron acceptor, and Escherichia coli K-12 as a reductant and redox buffer, we demonstate that 1) long-range EET by conductive pili requires the presence of flavins 2) Reduction by direct contact only requires the presence of a lowered electric potential 3) The limit of reduction by conductive pili is on the order of 15-20 microns. We are actively exploring the influence of hydrological conditions on the expression of different mechanisms of long-range EET, and the importance of extracellular cytochromes and pili conductivity on metal reduction.
Upper-bound solutions to flow through conical converging dies
International Nuclear Information System (INIS)
Limit analysis is a very versatile modeling technique that can be used to study metal-forming processes. The upper-bound analysis can be used to predict an upper limit on the power requirements. This work reviews some upper-bound solutions that describe flow through conical converging dies. The concept of a trapezoidal field is introduced and dealt with in great detail, and the power requirements based on the trapezoidal field are calculated. Results are compared with those obtained using spherical and triangular fields. The relative stress expression has been developed analytically and the final optimization with respect to the pseudoindependent parameter is done numerically. The trapezoidal field predicts a lower upper-bound solution for small semicone angles. The range over which the trapezoidal field solution becomes dominant increases with increasing friction factor
Echeverria, Alex; Silva, Jorge F.; Mendez, Rene A.; Orchard, Marcos
2016-10-01
Context. The best precision that can be achieved to estimate the location of a stellar-like object is a topic of permanent interest in the astrometric community. Aims: We analyze bounds for the best position estimation of a stellar-like object on a CCD detector array in a Bayesian setting where the position is unknown, but where we have access to a prior distribution. In contrast to a parametric setting where we estimate a parameter from observations, the Bayesian approach estimates a random object (i.e., the position is a random variable) from observations that are statistically dependent on the position. Methods: We characterize the Bayesian Cramér-Rao (CR) that bounds the minimum mean square error (MMSE) of the best estimator of the position of a point source on a linear CCD-like detector, as a function of the properties of detector, the source, and the background. Results: We quantify and analyze the increase in astrometric performance from the use of a prior distribution of the object position, which is not available in the classical parametric setting. This gain is shown to be significant for various observational regimes, in particular in the case of faint objects or when the observations are taken under poor conditions. Furthermore, we present numerical evidence that the MMSE estimator of this problem tightly achieves the Bayesian CR bound. This is a remarkable result, demonstrating that all the performance gains presented in our analysis can be achieved with the MMSE estimator. Conclusions: The Bayesian CR bound can be used as a benchmark indicator of the expected maximum positional precision of a set of astrometric measurements in which prior information can be incorporated. This bound can be achieved through the conditional mean estimator, in contrast to the parametric case where no unbiased estimator precisely reaches the CR bound.
Comparisons of Limit Analysis Solutions and Random Search Solutions on Slope Critical Slip SUrface
Institute of Scientific and Technical Information of China (English)
JianfengWANG
1998-01-01
The object of this paper is twofold:to present a kinematics limit analysis for assessing the safety of slope or its critical slip surface,and to compare the searched slip surface with that by limit analysis.
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.
Limit analysis of extended reach drilling in South China Sea
Institute of Scientific and Technical Information of China (English)
Gao Deli; Tan Chengjin; Tang Haixiong
2009-01-01
Extended reach wells (ERWs), especially horizontal extended reach well with a high HD (horizontal displacement) to TVD (true vertical depth) ratio, represent a frontier technology and challenge the drilling limitations.Oil and gas reservoir in beaches or lakes and offshore can be effectively exploited by using extended reach drilling (ERD) technology.This paper focuses on the difficult technological problems encountered during exploiting the Liuhua 11-1 oil field in the South China Sea, China.Emphasis is on investigating the key subjects including prediction and control of open hole limit extension in offshore ERD, prediction of casing wear and its prevention and torque reduction, φ244.5mm casing running with floating collars to control drag force, and steerable drilling modes.The basic concept of limit extension in ERD is presented and the prediction method for open hole limit extension is given in this paper.A set of advanced drilling mechanics and control technology has been established and its practical results are verified by field cases.All those efforts may be significant for further investigating and practicing ERD limit theory and control technology in the future.
DEFF Research Database (Denmark)
Milana, Marcella
territories. It does so by looking at a concrete country, the USA, and questioning whether and how broader (national) party values about education, training for job and the country’s sustainable development feed into the ongoing legal debate about adult basic education. This work is part of a broader project......). Such 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...... 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 delimited...
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...
Analysis of Strehl ratio limit with superresolution binary phase filters
Institute of Scientific and Technical Information of China (English)
Vidal F.Canales; Pedro J.Valle; Manuel P.Cagigal
2016-01-01
Several pupil filtering techniques have been developed in the last few years to obtain transverse superresolution (a narrower point spread function core).Such a core decrease entails two relevant limitations:a decrease of the peak intensity and an increase of the sidelobe intensity.Here,we calculate the Strehl ratio as a function of the core size for the most used binary phase filters.Furthermore,we show that this relation approaches the fundamental limit of the attainable Strehl ratio at the focal plane for any filter.Finally,we show the calculation of the peak-to-sidelobe ratio in order to check the system viability in every application.
Heavy-traffic Analysis of K-limited Polling
M.A.A. Boon; E.M.M. Winands
2014-01-01
In this paper, we study a two-queue polling model with zero switchover times and k-limited service (serve at most k i customers during one visit period to queue i, i=1, 2) in each queue. The arrival processes at the two queues are Poisson, and the service times are exponentially distributed. By incr
International Nuclear Information System (INIS)
Many structural components, such as rolled sheets, directionally solidified superalloys and composites are made of anisotropic materials. The knowledge of limit load is useful in the design and the sizing of these components and structures. This paper presents the extension of the modified mα - method to anisotropic materials. Mura's variational principle is employed in conjunction with repeated elastic finite element analyses (FEA). The secant modulus of the discretized finite elements in the reference direction components. The modified initial elastic properties are adopted to ensure the 'elastic' stress fields satisfy the anisotropic yield surface. Using the notion of 'leap-frogging to limit state,' improved lower-bound limit loads can be obtained. The formulation is applied to two anisotropic components, and the limit load estimates are compared with those using elastic compensation method and inelastic FEA. (author)
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
Bounded Densities and Their Derivatives
DEFF Research Database (Denmark)
Kozine, Igor; Krymsky, V.
2009-01-01
This paper describes how one can compute interval-valued statistical measures given limited information about the underlying distribution. The particular focus is on a bounded derivative of a probability density function and its combination with other available statistical evidence for computing...
Bounds for the rectification efficiency of solar radiation
Mashaal, Heylal; Gordon, Jeffrey M.
2013-09-01
Efficiency bounds for the rectification (AC to DC conversion) efficiency of non-coherent broadband radiation are derived, motivated by determining a basic limit for solar rectifying antennas. The limit is shown to be 2/π for a single full-wave rectifier. We also derive the increase in rectification efficiency that is possible by cascading multiple rectifiers. The approach for deriving the broadband limit follows from an analysis of sinusoidal signals of random phase. This analysis is also germane for harvesting ambient radio-frequency radiation from multiple uncorrelated sources.
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...
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...
PLASTIC LIMIT ANALYSIS OF DUCTILE COMPOSITE STRUCTURES FROM MICRO-TO MACRO-MECHANICAL ANALYSIS
Institute of Scientific and Technical Information of China (English)
Hongtao Zhang; Yinghua Liu; Bingye Xu
2009-01-01
The load-bearing capacity of ductile composite structures comprised of periodic composites is studied by a combined micro/macromechanical approach. Firstly, on the microscopic level, a representative volume element (RVE) is selected to reflect the microstructures of the composite materials and the constituents are assumed to be elastic perfectly-plastic. Based on the homogenization theory and the static limit theorem, an optimization formulation to directly calculate the macroscopic strength domain of the RVE is obtained. The finite element modeling of the static limit analysis is formulated as a nonlinear mathematical programming and solved by the sequential quadratic programming method, where the temperature parameter method is used to construct the self-stress field. Secondly, Hill's yield criterion is adopted to connect the micromechanical and macromechanical analyses. And the limit loads of composite structures are worked out on the macroscopic scale. Finally, some examples and comparisons are shown.
Directory of Open Access Journals (Sweden)
Elisabeth J. Faassen
2016-02-01
Full Text Available Exposure to β-N-methylamino-l-alanine (BMAA might be linked to the incidence of amyotrophic lateral sclerosis, Alzheimer’s disease and Parkinson’s disease. Analytical chemistry plays a crucial role in determining human BMAA exposure and the associated health risk, but the performance of various analytical methods currently employed is rarely compared. A CYANOCOST initiated workshop was organized aimed at training scientists in BMAA analysis, creating mutual understanding and paving the way towards interlaboratory comparison exercises. During this workshop, we tested different methods (extraction followed by derivatization and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS analysis, or directly followed by LC-MS/MS analysis for trueness and intermediate precision. We adapted three workup methods for the underivatized analysis of animal, brain and cyanobacterial samples. Based on recovery of the internal standard D3BMAA, the underivatized methods were accurate (mean recovery 80% and precise (mean relative standard deviation 10%, except for the cyanobacterium Leptolyngbya. However, total BMAA concentrations in the positive controls (cycad seeds showed higher variation (relative standard deviation 21%–32%, implying that D3BMAA was not a good indicator for the release of BMAA from bound forms. Significant losses occurred during workup for the derivatized method, resulting in low recovery (<10%. Most BMAA was found in a trichloroacetic acid soluble, bound form and we recommend including this fraction during analysis.
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.
International Nuclear Information System (INIS)
Scattering of a particle by bound nucleons is discussed. Effects of nucleons that are bound in a nucleus are taken as a structure function. The way how to calculate the structure function is given. (author)
International Nuclear Information System (INIS)
Heuristic arguments are given that the C-, T-violating resonant electroexcitation amplitudes in the second resonance region are approx. (R/subK//R/subJ/) times the C-, T-conserving amplitudes, where R/subK/ (R/subJ/) is a typical interaction radius for the C-, T-violating (conserving) electromagnetic interaction. This result allows the use of an existing amplitude analysis in order to estimate that the expected Christ-Lee asymmetry in this energy region should be about (R/subK//R/subJ/) times (30 to 40 %) for q2 ma -0.5 (GeV/c)2. The experimental upper bound ( ma 2%) then gives a bound R/subK//R/subJ/ 0 decay asymmetries. This result is also in agreement with the bound R/subK//R/subJ/ approximately-less-than 1/20 obtained by previous authors in a dispersive calculation of the electric dipole moment of the neutron. Such small radii are shown to have unfavorable implications for the theory, and these are briefly discussed
Limit load analysis of thick-walled concrete structures
International Nuclear Information System (INIS)
The paper illustrates the interaction of constitutive modeling and finite element solution techniques for limit load prediction of concrete structures. On the constitutive side, an engineering model of concrete fracture is developed in which the Mohr-Coulomb criterion is augmented by tension cut-off to describe incipient failure. Upon intersection with the stress path the failure surface collapses for brittle behaviour according to one of three softening rules, no-tension, no-cohesion, and no-friction. The stress transfer accompanying the energy dissipation during local failure is modelled by several fracture rules which are examined with regard to ultimate load prediction. On the numerical side the effect of finite element idealization is studied first as far as ultimate load convergence is concerned. Subsequently, incremental tangential and initial load techniques are compared together with the effect of step size. Limit load analyses of a thick-walled concrete ring and a lined concrete reactor closure conclude the paper with examples from practical engineering. (orig.)
A flow calculus of mwp-bounds for complexity analysis
DEFF Research Database (Denmark)
Jones, Neil D.; Kristiansen, Lars
2010-01-01
We present a method for certifying that the values computed by an imperative program will be bounded by polynomials in the program's inputs. To this end, we introduce mwp-matrices and define a semantic relation ⊧ C : M, where C is a program and M is an mwp-matrix. It follows...... straightforwardly from our definitions that there exists M such that ⊧ C : M holds iff every value computed by C is bounded by a polynomial in the inputs. Furthermore, we provide a syntactical proof calculus and define the relation ⊢ C : M to hold iff there exists a derivation in the calculus where C...... : 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....
Numerical Analysis of Conductor Galloping Limitation by Oscillation Frequency Detuning
Directory of Open Access Journals (Sweden)
I. I. Serguey
2009-01-01
Full Text Available A numerical method has been developed for calculation of conductor oscillations at the moment of galloping that takes account of pendulum oscillation dampers in the form of eccentric loads. The method is recommended for a numerical analysis of various schemes pertaining to arrangement of horizontal pendulums in the span and their parameters including angles of their initial setting. The obtained results can be used for designing and operation of aerial power lines.
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, ...
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...
Energy Technology Data Exchange (ETDEWEB)
Gabrys, Charles M.; Yang Jun; Weliky, David P. [Michigan State University, Department of Chemistry (United States)], E-mail: weliky@cem.msu.edu
2003-05-15
2D slow-spinning, rotor-synchronized MAS exchange spectroscopy (SSRS-MASE) was applied to study local secondary structure of three structurally different peptides, two of which were membrane-bound. Each peptide was {sup 13}C carbonyl labeled at two adjacent residues in the peptide backbone. In general, this methodology is attractive for membrane-bound peptides because of its lenient spinning, decoupling, and RF homogeneity requirements.For a single set of raw SSRS-MASE data, two linearly independent methods exist for obtaining a 2D spectrum and each spectrum can be fit to obtain conformational constraints. An approach is described for combining the results of these two fits and this method is shown to work for spectra with both resolved and unresolved labeled site resonances. A spectrum is often fit well to a few different conformations which have somewhat different values of the fitting parameter {chi}{sup 2}. A simple statistical theory is developed which relates the {delta}{chi}{sup 2} difference between a local minimum and the global minimum {chi}{sup 2} to the likelihood that the local minimum conformation is the correct structure. Because uncertainty in the simulated data can also contribute to the overall fitting uncertainty, an empirical method is described for incorporating the simulation uncertainty into the {delta}{chi}{sup 2} analysis.These data analysis methods were tested on polycrystalline Ala-Gly-Gly and then applied to the membrane-bound melittin and HIV-1 fusion peptides. Melittin gave a best-fit {alpha} helical structure at Ala-4 while the fusion peptide gave a good-fit {beta} strand structure at Phe-8. The melittin analysis is in agreement with the known overall structure of this peptide.
International Nuclear Information System (INIS)
2D slow-spinning, rotor-synchronized MAS exchange spectroscopy (SSRS-MASE) was applied to study local secondary structure of three structurally different peptides, two of which were membrane-bound. Each peptide was 13C carbonyl labeled at two adjacent residues in the peptide backbone. In general, this methodology is attractive for membrane-bound peptides because of its lenient spinning, decoupling, and RF homogeneity requirements.For a single set of raw SSRS-MASE data, two linearly independent methods exist for obtaining a 2D spectrum and each spectrum can be fit to obtain conformational constraints. An approach is described for combining the results of these two fits and this method is shown to work for spectra with both resolved and unresolved labeled site resonances. A spectrum is often fit well to a few different conformations which have somewhat different values of the fitting parameter χ2. A simple statistical theory is developed which relates the Δχ2 difference between a local minimum and the global minimum χ2 to the likelihood that the local minimum conformation is the correct structure. Because uncertainty in the simulated data can also contribute to the overall fitting uncertainty, an empirical method is described for incorporating the simulation uncertainty into the Δχ2 analysis.These data analysis methods were tested on polycrystalline Ala-Gly-Gly and then applied to the membrane-bound melittin and HIV-1 fusion peptides. Melittin gave a best-fit α helical structure at Ala-4 while the fusion peptide gave a good-fit β strand structure at Phe-8. The melittin analysis is in agreement with the known overall structure of this peptide
International Nuclear Information System (INIS)
Energy harvesting from human motion addresses the growing need for battery-free health and wellness sensors in wearable applications. The major obstacles to harvesting energy in such applications are low and random frequencies due to the nature of human motion. This paper presents a generalized rotational harvester model in 3 dimensions to determine the upper bound of power output from real world measured data. Simulation results indicate much space for improvement on power generation comparing to existing devices. We have developed a rotational energy harvester for human motion that attempts to close the gap between theoretical possibility and demonstrated devices. Like previous work, it makes use of magnetically plucked piezoelectric beams. However, it more fully utilizes the space available and has many degrees of freedom available for optimization. Finally we present a prototype harvester based on the coupled harvester model with preliminary experimental validation
Energy Technology Data Exchange (ETDEWEB)
Milani, Gabriele, E-mail: milani@stru.polimi.it; Valente, Marco, E-mail: milani@stru.polimi.it [Department of Architecture, Built Environment and Construction Engineering (ABC), Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan (Italy)
2014-10-06
This study presents some results of a comprehensive numerical analysis on three masonry churches damaged by the recent Emilia-Romagna (Italy) seismic events occurred in May 2012. The numerical study comprises: (a) pushover analyses conducted with a commercial code, standard nonlinear material models and two different horizontal load distributions; (b) FE kinematic limit analyses performed using a non-commercial software based on a preliminary homogenization of the masonry materials and a subsequent limit analysis with triangular elements and interfaces; (c) kinematic limit analyses conducted in agreement with the Italian code and based on the a-priori assumption of preassigned failure mechanisms, where the masonry material is considered unable to withstand tensile stresses. All models are capable of giving information on the active failure mechanism and the base shear at failure, which, if properly made non-dimensional with the weight of the structure, gives also an indication of the horizontal peak ground acceleration causing the collapse of the church. The results obtained from all three models indicate that the collapse is usually due to the activation of partial mechanisms (apse, façade, lateral walls, etc.). Moreover the horizontal peak ground acceleration associated to the collapse is largely lower than that required in that seismic zone by the Italian code for ordinary buildings. These outcomes highlight that structural upgrading interventions would be extremely beneficial for the considerable reduction of the seismic vulnerability of such kind of historical structures.
Theoretical limits on detection and analysis of small earthquakes
Kwiatek, Grzegorz; Ben-Zion, Yehuda
2016-08-01
We investigate theoretical limits on detection and reliable estimates of source characteristics of small earthquakes using synthetic seismograms for shear/tensile dislocations on kinematic circular ruptures and observed seismic noise and properties of several acquisition systems (instrument response, sampling rate). Simulated source time functions for shear/tensile dislocation events with different magnitudes, static stress drops, and rupture velocities provide estimates for the amplitude and frequency content of P and S phases at various observation angles. The source time functions are convolved with a Green's function for a homogenous solid assuming given P, S wave velocities and attenuation coefficients and a given instrument response. The synthetic waveforms are superposed with average levels of the observed ambient seismic noise up to 1 kHz. The combined seismograms are used to calculate signal-to-noise ratios and expected frequency content of P and S phases at various locations. The synthetic simulations of signal-to-noise ratio reproduce observed ratios extracted from several well-recorded data sets. The results provide guidelines on detection of small events in various geological environments, along with information relevant to reliable analyses of earthquake source properties.
Mass Bounds for Flavour Mixing Bileptons
Tully, M B
1999-01-01
Mass bounds for doubly-charged bilepton gauge bosons are derived from constraints on fermion pair production at LEP and lepton-flavour violating charged lepton decays. The limit obtained of 700 GeV for the doubly-charged bilepton does not depend on the bilepton coupling being flavour-diagonal, unlike other bounds which have been given in the literature.
Energy Technology Data Exchange (ETDEWEB)
Chaaba, Ali; Aboussaleh, Mohamed [Moulay Ismail University National Higher School of Engineering, Meknes (Morocco); Bousshine, Lahbib [National Higher School of Electricity and Mechanics, Casablanca (Morocco); Boudaia, El Hassan [Faculty of Sciences and Technologies, Mghrila, Beni-Mellal (Morocco)
2011-11-15
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.
Dawson, Jay W; Messerly, Michael J; Beach, Raymond J; Shverdin, Miroslav Y; Stappaerts, Eddy A; Sridharan, Arun K; Pax, Paul H; Heebner, John E; Siders, Craig W; Barty, C P J
2008-08-18
We analyze the scalability of diffraction-limited fiber lasers considering thermal, non-linear, damage and pump coupling limits as well as fiber mode field diameter (MFD) restrictions. We derive new general relationships based upon practical considerations. Our analysis shows that if the fiber's MFD could be increased arbitrarily, 36 kW of power could be obtained with diffraction-limited quality from a fiber laser or amplifier. This power limit is determined by thermal and non-linear limits that combine to prevent further power scaling, irrespective of increases in mode size. However, limits to the scaling of the MFD may restrict fiber lasers to lower output powers. PMID:18711562
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.
Davlieva, Milya; Donarski, James; Wang, Jiachen; Shamoo, Yousif; Nikonowicz, Edward P
2014-01-01
Several protein-targeted RNA aptamers have been identified for a variety of applications and although the affinities of numerous protein-aptamer complexes have been determined, the structural details of these complexes have not been widely explored. We examined the structural accommodation of an RNA aptamer that binds bacterial r-protein S8. The core of the primary binding site for S8 on helix 21 of 16S rRNA contains a pair of conserved base triples that mold the sugar-phosphate backbone to S8. The aptamer, which does not contain the conserved sequence motif, is specific for the rRNA binding site of S8. The protein-free RNA aptamer adopts a helical structure with multiple non-canonical base pairs. Surprisingly, binding of S8 leads to a dramatic change in the RNA conformation that restores the signature S8 recognition fold through a novel combination of nucleobase interactions. Nucleotides within the non-canonical core rearrange to create a G-(G-C) triple and a U-(A-U)-U quartet. Although native-like S8-RNA interactions are present in the aptamer-S8 complex, the topology of the aptamer RNA differs from that of the helix 21-S8 complex. This is the first example of an RNA aptamer that adopts substantially different secondary structures in the free and protein-bound states and highlights the remarkable plasticity of RNA secondary structure.
Nur, Indriyani; Abdelkhalek, Nevien K; Motobe, Shiori; Nakamura, Ryota; Tsujikura, Masakazu; Somamoto, Tomonori; Nakao, Miki
2016-02-01
Complements have long been considered to be a pivotal component in innate immunity. Recent researches, however, highlight novel roles of complements in T-cell-mediated adaptive immunity. Membrane-bound complement regulatory protein CD46, a costimulatory protein for T cells, is a key molecule for T-cell immunomodulation. Teleost CD46-like molecule, termed Tecrem, has been newly identified in common carp and shown to function as a complement regulator. However, it remains unclear whether Tecrem is involved in T-cell immune response. We investigated Tecrem function related to T-cell responses in ginbuna crucian carp. Ginbuna Tecrem (gTecrem) proteins were detected by immunoprecipitation using anti-common carp Tecrem monoclonal antibody (mAb) and were ubiquitously expressed on blood cells including CD8α(+) and CD4(+) lymphocytes. gTecrem expression on leucocyte surface was enhanced after stimulation with the T-cell mitogen, phytohaemagglutinin (PHA). Coculture with the anti-Tecrem mAb significantly inhibited the proliferative activity of PHA-stimulated peripheral blood lymphocytes, suggesting that cross-linking of Tecrems on T-cells interferes with a signal transduction pathway for T-cell activation. These findings indicate that Tecrem may act as a T-cell moderator and imply that the complement system in teleost, as well as mammals, plays an important role for linking adaptive and innate immunity.
Improved bounds on the energy-minimizing strains in martensitic polycrystals
Peigney, Michaël
2016-07-01
This paper is concerned with the theoretical prediction of the energy-minimizing (or recoverable) strains in martensitic polycrystals, considering a nonlinear elasticity model of phase transformation at finite strains. The main results are some rigorous upper bounds on the set of energy-minimizing strains. Those bounds depend on the polycrystalline texture through the volume fractions of the different orientations. The simplest form of the bounds presented is obtained by combining recent results for single crystals with a homogenization approach proposed previously for martensitic polycrystals. However, the polycrystalline bound delivered by that procedure may fail to recover the monocrystalline bound in the homogeneous limit, as is demonstrated in this paper by considering an example related to tetragonal martensite. This motivates the development of a more detailed analysis, leading to improved polycrystalline bounds that are notably consistent with results for single crystals in the homogeneous limit. A two-orientation polycrystal of tetragonal martensite is studied as an illustration. In that case, analytical expressions of the upper bounds are derived and the results are compared with lower bounds obtained by considering laminate textures.
Tao, Li; Miao, Qian; Tehrani, Alireza Azhdari; Hajiashrafi, Taraneh; Hu, Mao-Lin; Morsali, Ali
2016-08-01
Three Ru(II) half-sandwich complexes containing (N,N)-bound Schiff-base ligands, [(η6-C6H6) RuCl(L1)]PF6 (1) L1 = (E)-1-(6-methylpyridin-2-yl)-N-(p-tolyl)methanimine, [(η6-p-cymene)RuCl(L1)]PF6 (2) and [(η6-p-cymene)RuCl(L2)]PF6(3) L2 = (E)-1-(6-bromopyridin-2-yl)-N-(p-tolyl)methanimine, were synthesized, characterized and their supramolecular structures were analyzed. The crystal packing of these compounds was studied using geometrical analysis and Hirshfeld surface analysis. The fluorescence behavior of these compounds was also studied. TD-DFT calculations were carried out to better understand the fluorescence properties of complexes 1-3. These compounds could be promising for the design of organometallic dye systems.
DEFF Research Database (Denmark)
Emiris, Ioannis Z.; Mourrain, Bernard; Tsigaridas, Elias
2010-01-01
) resultant by means of mixed volume, as well as recent advances on aggregate root bounds for univariate polynomials, and are applicable to arbitrary positive dimensional systems. We improve upon Canny's gap theorem [7] by a factor of O(dn-1), where d bounds the degree of the polynomials, and n is the number...... bound on the number of steps that subdivision-based algorithms perform in order to isolate all real roots of a polynomial system. This leads to the first complexity bound of Milne's algorithm [22] in 2D....
Entropy Bounds in Spherical Space
Brevik, I; Odintsov, S D; Brevik, Iver; Milton, Kimball A.; Odintsov, Sergei D.
2002-01-01
Exact calculations are given for the Casimir energy for various fields in $R\\times S^3$ geometry. The Green's function method naturally gives a result in a form convenient in the high-temperature limit, while the statistical mechanical approach gives a form appropriate for low temperatures. The equivalence of these two representations is demonstrated. Some discrepancies with previous work are noted. In no case, even for ${\\cal N}=4$ SUSY, is the ratio of entropy to energy found to be bounded.
Institute of Scientific and Technical Information of China (English)
Weiguo ZHANG; Qiang LIU; Xiang LI; Boling GUO
2012-01-01
This paper deals with the problem of the bounded traveling wave solutions'shape and the solution to the generalized Whitham-Broer-Kaup equation with the dissipation terms which can be called WBK equation for short.The authors employ the theory and method of planar dynamical systems to make comprehensive qualitative analyses to the above equation satisfied by the horizontal velocity component u(ξ) in the traveling wave solution (u(ξ),H(ξ)),and then give its global phase portraits.The authors obtain the existent conditions and the number of the solutions by using the relations between the components u(ξ) and H(ξ) in the solutions.The authors study the dissipation effect on the solutions,find out a critical value r*,and prove that the traveling wave solution (u(ξ),H(ξ)) appears as a kink profile solitary wave if the dissipation effect is greater,i.e.,|r| ≥ r*,while it appears as a damped oscillatory wave if the dissipation effect is smaller,i.e.,|r| r*.Two solitary wave solutions to the WBK equation without dissipation effect is also obtained.Based on the above discussion and according to the evolution relations of orbits corresponding to the component u(ξ) in the global phase portraits,the authors obtain all approximate damped oscillatory solutions ((u)(ξ),(H)(ξ)) under various conditions by using the undetermined coefficients method. Finally,the error between the approximate damped oscillatory solution and the exact solution is an infinitesimal decreasing exponentially.
Niculiţǎ, Mihai
2016-08-01
The morphology of landslides is influenced by the slide/flow of the material downslope. Usually, the distance of the movement of the material is greater than the width of the displaced material (especially for flows, but also the majority of slides); the resulting landslides have a greater length than width. In some specific geomorphologic environments (monoclinic regions, with cuesta landforms type) or as is the case for some types of landslides (translational slides, bank failures, complex landslides), for the majority of landslides, the distance of the movement of the displaced material can be smaller than its width; thus the landslides have a smaller length than width. When working with landslide inventories containing both types of landslides presented above, the analysis of the length and width of the landslides computed using usual geographic information system techniques (like bounding boxes) can be flawed. To overcome this flaw, I present an algorithm which uses both the geometry of the landslide polygon minimum oriented bounding box and a digital elevation model of the landslide topography for identifying the long vs. wide landslides. I tested the proposed algorithm for a landslide inventory which covers 131.1 km2 of the Moldavian Plateau, eastern Romania. This inventory contains 1327 landslides, of which 518 were manually classified as long and 809 as wide. In a first step, the difference in elevation of the length and width of the minimum oriented bounding box is used to separate long landslides from wide landslides (long landslides having the greatest elevation difference along the length of the bounding box). In a second step, the long landslides are checked as to whether their length is greater than the length of flow downslope (estimated with a flow-routing algorithm), in which case the landslide is classified as wide. By using this approach, the area under the Receiver Operating Characteristic curve value for the classification of the long vs. wide
Directory of Open Access Journals (Sweden)
Guenter Goerigk
2016-03-01
Full Text Available Anomalous small angle scattering measurements have been applied to diluted solutions of anionic polyacrylates decorated by specifically-interacting Pb2+ cations, revealing partial collapse of the polyacrylate into pearl-like subdomains with a size on the order of a few nanometers. From the pure-resonant scattering contribution of the Pb2+ cations, and from subsequent analysis of the resonant-invariant, the amount of Pb2+ cations condensed onto the polyanions with respect to the total amount of Pb2+ cations in the solvent was estimated. In order to scrutinize systematic limitations in the determination of the chemical concentrations of resonant scattering counterions in the collapsed phase, Monte Carlo simulations have been performed. The simulations are based on structural confinements at variable size in the range of few nanometers, which represent the collapsed subdomains in the polyanions. These confinements were gradually filled to a high degree of the volume fraction with resonant scattering counterions giving access to a resonant-invariant at a variable degree of filling. The simulations revealed in the limit of small structures a significant underestimation of the true degree of filling of the collapsed subdomains when determining chemical concentrations of Pb2+ cations from the resonant invariant.
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.
Bounds on double-diffusive convection
Balmforth, Neil J.; Ghadge, Shilpa A.; Kettapun, Atichart; Mandre, Shreyas D.
2006-12-01
We consider double-diffusive convection between two parallel plates and compute bounds on the flux of the unstably stratified species using the background method. The bound on the heat flux for Rayleigh Bénard convection also serves as a bound on the double-diffusive problem (with the thermal Rayleigh number equal to that of the unstably stratified component). In order to incorporate a dependence of the bound on the stably stratified component, an additional constraint must be included, like that used by Joseph (Stability of Fluid Motion, 1976, Springer) to improve the energy stability analysis of this system. Our bound extends Joseph's result beyond his energy stability boundary. At large Rayleigh number, the bound is found to behave like R_T(1/2) for fixed ratio R_S/R_T, where R_T and R_S are the Rayleigh numbers of the unstably and stably stratified components, respectively.
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.
Directory of Open Access Journals (Sweden)
Fatemeh Zahra Nazari Robati
2016-03-01
Full Text Available Today TS focus has altered from linguistics to cultural studies. Culture is the way of life; as such every text is culture-bound and includes items that are culture-specific. Translating these cultural-specific items (henceforth CSI has made translation a complicated task. Hijab, one of the controversial issues of the present day of Islam in the world is defined in one way through presenting terms for women clothing such as “Jilbab” in Quran. Using Davies' (2003 strategies of translating CSIs, as the theoretical framework, taking the Quranic-Arabic culture bound term “Jilbab” (33:59 as the object of the study, this corpus-based comparative descriptive research was an attempt to compare totally 64 Persian and English (54 in Persian and 12 in English translations of this term with two concerns regarding the adopted translation strategies: a linguistic (Persian and English concern, and b translators' gender concern (male and female. The analysis of data showed that the most adopted strategy in both Persian and English corpus was localization (in Persian 35.71%, and in English 46.66%. Male translators in Persian had more tendency to use localization (36.53% and female translators to addition and globalization (each 50%. Male translators in English were more inclined to localization (45.83%, and the female have used preservation, addition, globalization and localization with the same frequency (25%. Totally male translators were inclined to localization (39.47%, while the female to globalization and addition (33.33%.Keywords: CSI, Translation strategies, Comparative analysis, Quran, “Jilbab”
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...
Multicolor Bound Soliton Molecule
Luo, Rui; Lin, Qiang
2015-01-01
We show a new class of bound soliton molecule that exists in a parametrically driven nonlinear optical cavity with appropriate dispersion characteristics. The composed solitons exhibit distinctive colors but coincide in time and share a common phase, bound together via strong inter-soliton four-wave mixing and Cherenkov radiation. The multicolor bound soliton molecule shows intriguing spectral locking characteristics and remarkable capability of spectrum management to tailor soliton frequencies, which may open up a great avenue towards versatile generation and manipulation of multi-octave spanning phase-locked Kerr frequency combs, with great potential for applications in frequency metrology, optical frequency synthesis, and spectroscopy.
Efficiency limits for the rectification of solar radiation
Mashaal, Heylal; Gordon, Jeffrey M.
2013-05-01
Efficiency limits for rectifying (converting AC to DC) incoherent broadband radiation are presented, prompted by establishing a fundamental bound for solar rectennas. For an individual full-wave rectifier, the bound is 2/π. The efficiency boosts attainable with cascaded rectifiers are also derived. The derivation of the broadband limit follows from the analysis of an arbitrary number of random-phase sinusoidal signals, which is also relevant for harvesting ambient radio-frequency radiation from a discrete number of uncorrelated sources.
Fuzzy analysis of serviceability limit state of slender steel beam under bending
Energy Technology Data Exchange (ETDEWEB)
Kala, Zdeněk; Valeš, Jan [Brno University of Technology, Faculty of Civil Engineering, Department of Structural Mechanics Vevefi St. 95, ZIP 602 00, Brno (Czech Republic)
2015-03-10
In the present paper, deformations of a beam under equal end moments solved with influence of lateral buckling are studied. It has been found by numerical studies that the lateral deflection of slender beam under major axis bending can be relatively high.The acceptability of high values of lateral deflections within the framework of serviceability limit state is discussed. In the next part of the paper, the limit value of maximum deflection was introduced as a fuzzy number. The fuzzy analysis of the maximum moment which causes the maximum deflection was carried out. The slendernesses of beams for which the serviceability limit state is the limiting state for design were identified.
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...
Positivity bounds on double parton distributions
Energy Technology Data Exchange (ETDEWEB)
Diehl, Markus; Kasemets, Tomas
2013-03-15
Double hard scattering in proton-proton collisions is described in terms of double parton distributions. We derive bounds on these distributions that follow from their interpretation as probability densities, taking into account all possible spin correlations between two partons in an unpolarized proton. These bounds constrain the size of the polarized distributions and can for instance be used to set upper limits on the effects of spin correlations in double hard scattering. We show that the bounds are stable under leading-order DGLAP evolution to higher scales.
A Covariance Analysis Tool for Assessing Fundamental Limits of SIM Pointing Performance
Bayard, David S.; Kang, Bryan H.
2007-01-01
This paper presents a performance analysis of the instrument pointing control system for NASA's Space Interferometer Mission (SIM). SIM has a complex pointing system that uses a fast steering mirror in combination with a multirate control architecture to blend feed forward information with feedback information. A pointing covariance analysis tool (PCAT) is developed specifically to analyze systems with such complexity. The development of PCAT as a mathematical tool for covariance analysis is outlined in the paper. PCAT is then applied to studying performance of SIM's science pointing system. The analysis reveals and clearly delineates a fundamental limit that exists for SIM pointing performance. The limit is especially stringent for dim star targets. Discussion of the nature of the performance limit is provided, and methods are suggested to potentially improve pointing performance.
The neural basis of bounded rational behavior
Coricelli, Giorgio; Nagel, Rosemarie
2010-01-01
Bounded rational behaviour is commonly observed in experimental games and in real life situations. Neuroeconomics can help to understand the mental processing underlying bounded rationality and out-of-equilibrium behaviour. Here we report results from recent studies on the neural basis of limited steps of reasoning in a competitive setting —the beauty contest game. We use functional magnetic resonance imaging (fMRI) to study the neural correlates of human mental processes in strategic games. ...
Shen, Simon; Syal, Karan; Tao, Nongjian; Wang, Shaopeng
2015-12-01
We present a Single-Cell Motion Characterization System (SiCMoCS) to automatically extract bacterial cell morphological features from microscope images and use those features to automatically classify cell motion for rod shaped motile bacterial cells. In some imaging based studies, bacteria cells need to be attached to the surface for time-lapse observation of cellular processes such as cell membrane-protein interactions and membrane elasticity. These studies often generate large volumes of images. Extracting accurate bacterial cell morphology features from these images is critical for quantitative assessment. Using SiCMoCS, we demonstrated simultaneous and automated motion tracking and classification of hundreds of individual cells in an image sequence of several hundred frames. This is a significant improvement from traditional manual and semi-automated approaches to segmenting bacterial cells based on empirical thresholds, and a first attempt to automatically classify bacterial motion types for motile rod shaped bacterial cells, which enables rapid and quantitative analysis of various types of bacterial motion. PMID:26724085
Duyck, Dieter; Capirone, Daniele; Moeneclaey, Marc
2012-01-01
Joint network-channel codes (JNCC) can improve the performance of communication in wireless networks, by combining, at the physical layer, the channel codes and the network code as an overall error-correcting code. JNCC is increasingly proposed as an alternative to a standard layered construction, such as the OSI-model. The main performance metrics for JNCCs are scalability to larger networks and error rate. The diversity order is one of the most important parameters determining the error rate. The literature on JNCC is growing, but a rigorous diversity analysis is lacking, mainly because of the many degrees of freedom in wireless networks, which makes it very hard to prove general statements on the diversity order. In this paper, we consider a network with slowly varying fading point-to-point links, where all sources also act as relay and additional non-source relays may be present. We propose a general structure for JNCCs to be applied in such network. In the relay phase, each relay transmits a linear trans...
International Nuclear Information System (INIS)
Since the 9-11 attacks, the United States has increased its focus on developing technologies designed to warn us in the event of another attack and to prevent these attacks from happening in the first place. The SensorNet research group at Oak Ridge National Laboratory's (ORNL) Computer Science and Engineering Division is participating in this effort by developing systems to give critical real-time information to federal, state, and local emergency response decision makers. SensorNet has approached this goal by putting together a system with several sensors and programs called the Southeastern Transportation Corridor Pilot project (SETCP). The SETCP utilizes interstate weigh stations not only to weigh the passing trucks but also to check for gamma and neutron radiation inside the truck without the aid of a human in close proximity. The system also collects additional data that help identify the truck (the truck's length, weight, license plate number, and photographs of the truck). The objective of this research work was to characterize and analyze the data collected from the South Carolina weigh station on I-26W and compare it with previous data analysis on the performance of the Tennessee weigh station on I-40E. The purpose was to find patterns in the trucks with radioactive alarms and, regional truck traffic, as well as to find patterns of inconsistency in the system (illogical length measurements of the truck, inaccurate readings and character recognition of the license plate). During a three-month period, radioactive alarms and traffic patterns were identified and characterized by grouping all of the data and making graphs and charts in Microsoft Excel to show the flow of traffic, the type of truck traffic, the number of alarms and other information. Inconsistence patterns were found by analyzing the data, looking for missing or illogical information, and determining how often it happens. The improvements of these inconsistencies were also analyzed after
Ma, Xiaolei; Barthelemy, Pierre A; Rouge, Lionel; Wiesmann, Christian; Sidhu, Sachdev S
2013-06-26
We compared the capacity of an autonomous heavy chain variable (VH) domain (VH-B1a) to support diversity within its antigen-binding site relative to the conventional antigen-binding fragment (Fab) from which it was derived. We find that VH-B1a can tolerate significant diversity within all three complementarity-determining regions (CDRs) and also within framework 3, and thus, VH-B1a and the Fab are similar in terms of the regions of the antigen-binding site that can tolerate diversity without compromising stability. We constructed libraries of synthetic VH domains and isolated binders with moderate affinity for vascular endothelial growth factor (VEGF) from a library in which only CDR3 was randomized. One binder was subjected to affinity maturation to derive an autonomous VH domain (VH-V1a) that recognized both human and mouse VEGF with high affinity (KD=16nM or 10nM, respectively). Structural analysis revealed that VH-V1a binds to an epitope that is distinct from the epitopes of a natural VEGF receptor and six different anti-VEGF Fabs. Moreover, VH-V1a recognizes VEGF by using an unusual paratope consisting predominantly of CDR3 but with significant contributions from framework residues within the former light chain interface. These results suggest that VH-B1a and other autonomous VH domains may be useful scaffolds to support both conventional libraries with antigen-binding sites built from the three CDR loops and, also, nonconventional libraries with antigen-binding sites built from CDR3 and the former light chain interface.
Genome-wide RIP-Chip analysis of translational repressor-bound mRNAs in the Plasmodium gametocyte
Guerreiro, Ana
2014-11-03
Background Following fertilization, the early proteomes of metazoans are defined by the translation of stored but repressed transcripts; further embryonic development relies on de novo transcription of the zygotic genome. During sexual development of Plasmodium berghei, a rodent model for human malaria species including P. falciparum, the stability of repressed mRNAs requires the translational repressors DOZI and CITH. When these repressors are absent, Plasmodium zygote development and transmission to the mosquito vector is halted, as hundreds of transcripts become destabilized. However, which mRNAs are direct targets of these RNA binding proteins, and thus subject to translational repression, is unknown. Results We identify the maternal mRNA contribution to post-fertilization development of P. berghei using RNA immunoprecipitation and microarray analysis. We find that 731 mRNAs, approximately 50% of the transcriptome, are associated with DOZI and CITH, allowing zygote development to proceed in the absence of RNA polymerase II transcription. Using GFP-tagging, we validate the repression phenotype of selected genes and identify mRNAs relying on the 5′ untranslated region for translational control. Gene deletion reveals a novel protein located in the ookinete crystalloid with an essential function for sporozoite development. Conclusions Our study details for the first time the P. berghei maternal repressome. This mRNA population provides the developing ookinete with coding potential for key molecules required for life-cycle progression, and that are likely to be critical for the transmission of the malaria parasite from the rodent and the human host to the mosquito vector.
Kim Oanh, Nguyen Thi; Leelasakultum, Ketsiri
2011-05-01
This study investigated the main causes of haze episodes in the northwestern Thailand to provide early warning and prediction. In an absence of emission input data required for chemical transport modeling to predict the haze, the climatological approach in combination with statistical analysis was used. An automatic meteorological classification scheme was developed using regional meteorological station data of 8years (2001-2008) which classified the prevailing synoptic patterns over Northern Thailand into 4 patterns. Pattern 2, occurring with high frequency in March, was found to associate with the highest levels of 24h PM(10) in Chiangmai, the largest city in Northern Thailand. Typical features of this pattern were the dominance of thermal lows over India, Western China and Northern Thailand with hot, dry and stagnant air in Northern Thailand. March 2007, the month with the most severe haze episode in Chiangmai, was found to have a high frequency of occurrence of pattern 2 coupled with the highest emission intensities from biomass open burning. Backward trajectories showed that, on haze episode days, air masses passed over the region of dense biomass fire hotspots before arriving at Chiangmai. A stepwise regression model was developed to predict 24h PM(10) for days of meteorology pattern 2 using February-April data of 2007-2009 and tested with 2004-2010 data. The model performed satisfactorily for the model development dataset (R(2)=87%) and test dataset (R(2)=81%), which appeared to be superior over a simple persistence regression of 24h PM(10) (R(2)=76%). Our developed model had an accuracy over 90% for the categorical forecast of PM(10)>120μg/m(3). The episode warning procedure would identify synoptic pattern 2 and predict 24h PM(10) in Chiangmai 24h in advance. This approach would be applicable for air pollution episode management in other areas with complex terrain where similar conditions exist.
Stress-based upper-bound method and convex optimization: case of the Gurson material
Pastor, Franck; Trillat, Malorie; Pastor, Joseph; Loute, Etienne
2006-04-01
A nonlinear interior point method associated with the kinematic theorem of limit analysis is proposed. Associating these two tools enables one to determine an upper bound of the limit loading of a Gurson material structure from the knowledge of the sole yield criterion. We present the main features of the interior point algorithm and an original method providing a rigorous kinematic bound from a stress formulation of the problem. This method is tested by solving in plane strain the problem of a Gurson infinite bar compressed between rough rigid plates. To cite this article: F. Pastor et al., C. R. Mecanique 334 (2006).
Pisano, Aurora; Weichert, Dieter
2015-01-01
Articles in this book examine various materials and how to determine directly the limit state of a structure, in the sense of limit analysis and shakedown analysis. Apart from classical applications in mechanical and civil engineering contexts, the book reports on the emerging field of material design beyond the elastic limit, which has further industrial design and technological applications. Readers will discover that “Direct Methods” and the techniques presented here can in fact be used to numerically estimate the strength of structured materials such as composites or nano-materials, which represent fruitful fields of future applications. Leading researchers outline the latest computational tools and optimization techniques and explore the possibility of obtaining information on the limit state of a structure whose post-elastic loading path and constitutive behavior are not well defined or well known. Readers will discover how Direct Methods allow rapid and direct access to requested information in...
Plastic Limit Load Analysis of Cylindrical Pressure Vessels with Different Nozzle Inclination
Prakash, Anupam; Raval, Harit Kishorchandra; Gandhi, Anish; Pawar, Dipak Bapu
2016-04-01
Sudden change in geometry of pressure vessel due to nozzle cutout, leads to local stress concentration and deformation, decreasing its strength. Elastic plastic analysis of cylindrical pressure vessels with different inclination angles of nozzle is important to estimate plastic limit load. In the present study, cylindrical pressure vessels with combined inclination of nozzles (i.e. in longitudinal and radial plane) are considered for elastic plastic limit load analysis. Three dimensional static nonlinear finite element analyses of cylindrical pressure vessels with nozzle are performed for incremental pressure loading. The von Mises stress distribution on pressure vessel shows higher stress zones at shell-nozzle junction. Approximate plastic limit load is obtained by twice elastic slope method. Variation in limit pressure with different combined inclination angle of nozzle is analyzed and found to be distinct in nature. Reported results can be helpful in optimizing pressure vessel design.
Hoyer, Paul
2016-01-01
Even a first approximation of bound states requires contributions of all powers in the coupling. This means that the concept of "lowest order bound state" needs to be defined. In these lectures I discuss the "Born" (no loop, lowest order in $\\hbar$) approximation. Born level states are bound by gauge fields which satisfy the classical field equations. As a check of the method, Positronium states of any momentum are determined as eigenstates of the QED Hamiltonian, quantized at equal time. Analogously, states bound by a strong external field $A^\\mu(\\xv)$ are found as eigenstates of the Dirac Hamiltonian. Their Fock states have dynamically created $e^+e^-$ pairs, whose distribution is determined by the Dirac wave function. The linear potential of $D=1+1$ dimensions confines electrons but repels positrons. As a result, the mass spectrum is continuous and the wave functions have features of both bound states and plane waves. The classical solutions of Gauss' law are explored for hadrons in QCD. A non-vanishing bo...
Bounding species distribution models
Institute of Scientific and Technical Information of China (English)
Thomas J. STOHLGREN; Catherine S. JARNEVICH; Wayne E. ESAIAS; Jeffrey T. MORISETTE
2011-01-01
Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern.Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development,yet there is no recommended best practice for “clamping” model extrapolations.We relied on two commonly used modeling approaches:classification and regression tree (CART) and maximum entropy (Maxent) models,and we tested a simple alteration of the model extrapolations,bounding extrapolations to the maximum and minimum values of primary environmental predictors,to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States.Findings suggest that multiple models of bounding,and the most conservative bounding of species distribution models,like those presented here,should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5):642-647,2011].
Energy Technology Data Exchange (ETDEWEB)
Li, Shihong [Department of Radiology, University of California, San Diego, California 92103-8226 (United States); Department of Radiology, Hua Dong Hospital, Fudan University, Shanghai 200040 (China); Yancheng Medical College, Jiangsu (China); The First People' s Hospital of Yancheng City, Jiangsu 224005 (China); Chang, Eric Y.; Chung, Christine B. [VA San Diego Healthcare System, San Diego, California 92161 and Department of Radiology, University of California, San Diego, California 92103-8226 (United States); Bae, Won C.; Du, Jiang, E-mail: jiangdu@ucsd.edu [Department of Radiology, University of California, San Diego, California 92103-8226 (United States); Hua, Yanqing [Department of Radiology, Hua Dong Hospital, Fudan University, Shanghai 200040 (China); Zhou, Yi [The First People' s Hospital of Yancheng City, Jiangsu 224005 (China)
2014-02-15
Purpose: The purpose of this study was to investigate the effect of excitation, fat saturation, long T2 saturation, and adiabatic inversion pulses on ultrashort echo time (UTE) imaging with bicomponent analysis of bound and free water in cortical bone for potential applications in osteoporosis. Methods: Six bovine cortical bones and six human tibial midshaft samples were harvested for this study. Each bone sample was imaged with eight sequences using 2D UTE imaging at 3T with half and hard excitation pulses, without and with fat saturation, long T2 saturation, and adiabatic inversion recovery (IR) preparation pulses. Single- and bicomponent signal models were utilized to calculate the T2{sup *}s and/or relative fractions of short and long T2{sup *}s. Results: For all bone samples UTE T2{sup *} signal decay showed bicomponent behavior. A higher short T2{sup *} fraction was observed on UTE images with hard pulse excitation compared with half pulse excitation (75.6% vs 68.8% in bovine bone, 79.9% vs 73.2% in human bone). Fat saturation pulses slightly reduced the short T2{sup *} fraction relative to regular UTE sequences (5.0% and 2.0% reduction, respectively, with half and hard excitation pulses for bovine bone, 6.3% and 8.2% reduction, respectively, with half and hard excitation pulses for human bone). Long T2 saturation pulses significantly reduced the long T2{sup *} fraction relative to regular UTE sequence (18.9% and 17.2% reduction, respectively, with half and hard excitation pulses for bovine bone, 26.4% and 27.7% reduction, respectively, with half and hard excitation pulses for human bone). With IR-UTE preparation the long T2{sup *} components were significantly reduced relative to regular UTE sequence (75.3% and 66.4% reduction, respectively, with half and hard excitation pulses for bovine bone, 87.7% and 90.3% reduction, respectively, with half and hard excitation pulses for human bone). Conclusions: Bound and free water T2{sup *}s and relative fractions can
Energy Technology Data Exchange (ETDEWEB)
Badard, M.; Veillerot, M
2007-07-01
This training course report presents the different methods of detection and quantifying of metallic impurities in semiconductors. One of the most precise technique is the collection of metal impurities by vapor phase decomposition (VPD) followed by their analysis by ICPMS (inductively coupled plasma mass spectrometry). The study shows the importance of detection limits in the domain of chemical analysis and the way to determine them for the ICPMS analysis. The results found on detection limits are excellent. Even if the detection limits reached with ICPMS performed after manual or automatic VPD are much higher than detection limits of ICPMS alone, this method remains one of the most sensible for ultra-traces analysis. (J.S.)
Energy Technology Data Exchange (ETDEWEB)
Warne, L.K.; Merewether, K.O.; Chen, K.C.; Jorgenson, R.E.; Morris, M.E.; Solberg, J.E.; Lewis, J.G. [Sandia National Labs., Albuquerque, NM (United States); Derr, W. [Derr Enterprises, Albuquerque, NM (United States)
1996-07-01
Test data on canonical weapon-like fixtures are used to validate previously developed analytical bounding results. The test fixtures were constructed to simulate (but be slightly worse than) weapon ports of entry but have known geometries (and electrical points of contact). The exterior of the test fixtures exhibited exterior resonant enhancement of the incident fields at the ports of entry with magnitudes equal to those of weapon geometries. The interior consisted of loaded transmission lines adjusted to maximize received energy or voltage but incorporating practical weapon geometrical constraints. New analytical results are also presented for bounding the energies associated with multiple bolt joints and for bounding the exterior resonant enhancement of the exciting fields.
Information, Utility & Bounded Rationality
Ortega, Pedro A
2011-01-01
Perfectly rational decision-makers maximize expected utility, but crucially ignore the resource costs incurred when determining optimal actions. Here we employ an axiomatic framework for bounded rational decision-making based on a thermodynamic interpretation of resource costs as information costs. This leads to a variational "free utility" principle akin to thermodynamical free energy that trades off utility and information costs. We show that bounded optimal control solutions can be derived from this variational principle, which leads in general to stochastic policies. Furthermore, we show that risk-sensitive and robust (minimax) control schemes fall out naturally from this framework if the environment is considered as a bounded rational and perfectly rational opponent, respectively. When resource costs are ignored, the maximum expected utility principle is recovered.
Multivariate analysis of adaptive capacity for upper thermal limits in Drosophila simulans.
van Heerwaarden, B; Sgrò, C M
2013-04-01
Thermal tolerance is an important factor influencing the distribution of ectotherms, but our understanding of the ability of species to evolve different thermal limits is limited. Based on univariate measures of adaptive capacity, it has recently been suggested that species may have limited evolutionary potential to extend their upper thermal limits under ramping temperature conditions that better reflect heat stress in nature. To test these findings more broadly, we used a paternal half-sibling breeding design to estimate the multivariate evolutionary potential for upper thermal limits in Drosophila simulans. We assessed heat tolerance using static (basal and hardened) and ramping assays. Our analyses revealed significant evolutionary potential for all three measures of heat tolerance. Additive genetic variances were significantly different from zero for all three traits. Our G matrix analysis revealed that all three traits would contribute to a response to selection for increased heat tolerance. Significant additive genetic covariances and additive genetic correlations between static basal and hardened heat-knockdown time, marginally nonsignificant between static basal and ramping heat-knockdown time, indicate that direct and correlated responses to selection for increased upper thermal limits are possible. Thus, combinations of all three traits will contribute to the evolution of upper thermal limits in response to selection imposed by a warming climate. Reliance on univariate estimates of evolutionary potential may not provide accurate insight into the ability of organisms to evolve upper thermal limits in nature.
Nikolantonaki, Maria; Magiatis, Prokopios; Waterhouse, Andrew L
2015-11-01
Recent developments that have accelerated 2D NMR methods and improved quantitation have made these methods accessible analytical procedures, and the large signal dispersion allows for the analysis of complex samples. Few natural samples are as complex as wine, so the application to challenges in wine analysis look promising. The analysis of carbonyl compounds in wine, key oxidation products, is complicated by a multitude of kinetically reversible adducts, such as acetals and sulfonates, so that sample preparation steps can generate complex interferences. These challenges could be overcome if the compounds could be quantified in situ. Here, two-dimensional ((1)H-(1)H) homonuclear and heteronuclear ((13)C-(1)H) single quantum correlations (correlation spectroscopy, COSY, and heteronuclear single quantum coherence, HSQC) nuclear magnetic resonance spectra of undiluted wine samples were observed at natural abundance. These techniques achieve simultaneous direct identification and quantitation of acetaldehyde, pyruvic acid, acetoin, methylglyoxal, and α-ketoglutaric acid in wine with only a small addition of D2O. It was also possible to observe and sometimes quantify the sulfite, hydrate, and acetal forms of the carbonyl compounds. The accuracy of the method was tested in wine samples by spiking with a mixture of all analytes at different concentrations. The method was applied to 15 wine samples of various vintages and grape varieties. The application of this method could provide a powerful tool to better understand the development, evolution, and perception of wine oxidation and insight into the impact of these sulfite bound carbonyls on antimicrobial and antioxidant action by SO2.
Energy Technology Data Exchange (ETDEWEB)
Ouattara, B; Khouzam, A; Mojtabi, A [Universite de Toulouse (France); INPT, UPS (France); IMFT (Institut de Mecanique des Fluides de Toulouse), Allee Camille Soula, F-31400 Toulouse (France); Charrier-Mojtabi, M C, E-mail: bouattar@imft.fr, E-mail: akhouzam@imft.fr, E-mail: mojtabi@imft.fr, E-mail: cmojtabi@cict.fr [PHASE, EA 810, UFR PCA, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse cedex (France)
2012-06-01
The aim of this study was to investigate the effect of conducting boundaries on the onset of convection in a binary fluid-saturated porous layer. The isotropic saturated porous layer is bounded by two impermeable but thermally conducting plates, subjected to a constant heat flux. These plates have identical conductivity. Moreover, the conductivity of the plates is generally different from the porous layer conductivity. The overall layer is of large extent in both horizontal directions. The problem is governed by seven dimensionless parameters, namely the normalized porosity of the medium {epsilon}, the ratio of plates over the porous layer thickness {delta} and their relative thermal conductivities ratio d, the separation ratio {delta}, the Lewis number Le and thermal Rayleigh number Ra. In this work, an analytical and numerical stability analysis is performed. The equilibrium solution is found to lose its stability via a stationary bifurcation or a Hopf bifurcation depending on the values of the dimensionless parameters. For the long-wavelength mode, the critical Rayleigh number is obtained as Ra{sub cs}=12(1+2d{delta} )/[1+{psi} (2d{delta}Le+Le+1)] and k{sub cs}=0 for {psi}> {psi} {sub uni}> 0. This work extends an earlier paper by Mojtabi and Rees (2011 Int. J. Heat Mass Transfer 54 293-301) who considered a configuration where the porous layer is saturated by a pure fluid.
Analysis of Lithium Driven Electron Density Peaking in FTU Liquid Lithium Limiter Experiments
Szepesi, G.; Romanelli, M.; Militello, F.; Peeters, A.; Camenen, Y.; Casson, F.; Hornsby, W.; Snodin, A.; Wagner, D.
2013-01-01
The impact of lithium impurities on the microstability and turbulent transport characteristics in the core of a typical FTU Liquid Lithium Limiter (LLL)(Mazzitelli et al., Nucl. Fusion, 2011) discharge during the density ramp-up phase is studied. A non-linear gyrokinetic analysis performed with GKW (Peeters et al.,Comp. Phys. Comm., 2009) accompanied by a quasi-linear fluid analysis is presented. We show that a centrally peaked, high concentration lithium profile contributes to the electron p...
Lower bounds on fluctuations for internal DLA
Asselah, Amine
2011-01-01
We consider internal diffusion limited aggregation in dimension larger than or equal to two. This is a random cluster growth model, where random walks start at the origin of the d-dimensional lattice, one at a time, and stop moving when reaching a site that is not occupied by previous walks. When n random walks are sent from the origin, we establish a lower bound for the inner and outer errors fluctuations of order square root of the logarithm of n. When dimension is larger or equal to three, this lower bound matches the upper bound recently obtained in independent works of \\cite{AG2} and \\cite{JLS2}. Also, we produce as a corollary of our proof of \\cite{AG2}, an upper bound for the fluctuation of the inner error in a specified direction.
The Fitness Level Method with Tail Bounds
Witt, Carsten
2013-01-01
The fitness-level method, also called the method of f-based partitions, is an intuitive and widely used technique for the running time analysis of randomized search heuristics. It was originally defined to prove upper and lower bounds on the expected running time. Recently, upper tail bounds were added to the technique; however, these tail bounds only apply to running times that are at least twice as large as the expectation. We remove this restriction and supplement the fitness-level method ...
Economic valuation through cost-benefit analysis--possibilities and limitations.
Hansjürgens, Bernd
2004-12-15
The economic approach used to evaluate effects on human health and the environment centres around cost-benefit analysis (CBA). Thus, for most economists, economic valuation and CBA are one and the same. However, the question of the possibilities and limitations of cost-benefit analysis is one of the most controversial aspects of environmental research. In this paper, the possibilities and limitations of CBA are analysed. This is done not only by explaining the central elements of CBA, but also by commenting on criticism of it. What becomes clear is that CBA is not only a mere mechanism of monetarisation, but a heuristic model for the whole process of valuation. It can serve as a guideline for collecting the necessary data in a systematic way. The limits of CBA can be mainly seen in the non-substitutability of essential goods, irreversibility, long-term effects and inter-generational fairness.
DEFF Research Database (Denmark)
Damgård, Ivan Bjerre; Faust, Sebastian; Mukherjee, Pratyay;
2013-01-01
a public tamper-proof common reference string. Finally, we explain how to boost bounded tampering and leakage resilience (as in 1. and 2. above) to continuous tampering and leakage resilience, in the so-called floppy model where each user has a personal hardware token (containing leak- and tamper...
Bounds in the generalized Weber problem under locational uncertainty
DEFF Research Database (Denmark)
Juel, Henrik
1981-01-01
An existing analysis of the bounds on the Weber problem solution under uncertainty is incorrect. For the generalized problem with arbitrary measures of distance, we give easily computable ranges on the bounds and state the conditions under which the exact values of the bounds can be found...
The stochastic limit in the analysis of the open BCS model
Bagarello, F
2009-01-01
In this paper we show how the perturbative procedure known as {\\em stochastic limit} may be useful in the analysis of the Open BCS model discussed by Buffet and Martin as a spin system interacting with a fermionic reservoir. In particular we show how the same values of the critical temperature and of the order parameters can be found with a significantly simpler approach.
DEFF Research Database (Denmark)
Sun, Bo; Trintis, Ionut; Munk-Nielsen, Stig;
2016-01-01
online adapt its dc-link voltage reference based on the system operating state. Furthermore, the relationship between current THD, minimum pulse width limitation and Mmax index reference is analyzed in order to obtain an optimized performance of the system. Finally, the dynamic performance and analysis...
Ostertag, Rebecca; DiManno, Nicole
2016-03-01
Examining foliar nutrient concentrations after fertilization provides an alternative method for detecting nutrient limitation of ecosystems, which is logistically simpler to measure than biomass change. We present a meta-analysis of response ratios of foliar nitrogen and phosphorus (RRN, RRP) after addition of fertilizer of nitrogen (N), phosphorus (P), or the two elements in combination, in relation to climate, ecosystem type, life form, family, and methodological factors. Results support other meta-analyses using biomass, and demonstrate there is strong evidence for nutrient limitation in natural communities. However, because N fertilization experiments greatly outnumber P fertilization trials, it is difficult to discern the absolute importance of N vs. P vs. co-limitation across ecosystems. Despite these caveats, it is striking that results did not follow "conventional wisdom" that temperate ecosystems are N-limited and tropical ones are P-limited. In addition, the use of ratios of N-to-P rather than response ratios also are a useful index of nutrient limitation, but due to large overlap in values, there are unlikely to be universal cutoff values for delimiting N vs. P limitation. Differences in RRN and RRP were most significant across ecosystem types, plant families, life forms, and between competitive environments, but not across climatic variables.
Energy Technology Data Exchange (ETDEWEB)
Regalbuto, M.C.; Misra, B.; Chamberlain, D.B.; Leonard, R.A.; Vandegrift, G.F.
1992-04-01
The Generic TRUEX Model (GTM) was used to design a flowsheet for the TRUEX solvent extraction process that would be used to determine its instrumentation and control requirements. Sensitivity analyses of the key process variables, namely, the aqueous and organic flow rates, feed compositions, and the number of contactor stages, were carried out to assess their impact on the operation of the TRUEX process. Results of these analyses provide a basis for the selection of an instrument and control system and the eventual implementation of a control algorithm. Volume Two of this report is an evaluation of the instruments available for measuring many of the physical parameters. Equations that model the dynamic behavior of the TRUEX process have been generated. These equations can be used to describe the transient or dynamic behavior of the process for a given flowsheet in accordance with the TRUEX model. Further work will be done with the dynamic model to determine how and how quickly the system responds to various perturbations. The use of perturbation analysis early in the design stage will lead to a robust flowsheet, namely, one that will meet all process goals and allow for wide control bounds. The process time delay, that is, the speed with which the system reaches a new steady state, is an important parameter in monitoring and controlling a process. In the future, instrument selection and point-of-variable measurement, now done using the steady-state results reported here, will be reviewed and modified as necessary based on this dynamic method of analysis.
Institute of Scientific and Technical Information of China (English)
余生兵; 黄茂松
2011-01-01
基于极限分析法的基本原理以及集成与组合的思路,推导组合块体集的内能耗散和重力做功,运用组合的思想构造斜坡地形下浅埋水平条形锚板的运动许可速度场.首先分析地表水平条件下法向受力水平条形锚板抗拔承载力,并与文献中已有解和模型试验进行对比,验证块体集上限法的优越性.然后详细研究斜坡地形条件下土体重度、不排水抗剪强度、斜坡倾角等因素对条形锚板抗拔承载力和破坏面形状的影响.分析结果表明:重力叠加法并不适用于斜坡地形情况;随着斜坡倾角的增大,锚板的破坏面向坡角方向倾斜;锚板埋深比越大,斜坡倾角的影响也越显著.块体集上限分析方法构造简单,求解快捷,能够为工程设计提供依据.%Based on the bound theorems of limit analysis, admissible velocity field of horizontal strip anchor is constructed by using a combination of several rotational block sets. An application to upper bound analysis of vertically loaded strip anchors on horizontal ground surface is given first to illustrate the utility and effectiveness of the proposed method, and include detailed comparisons with results obtained from other approaches. Then the pull-out capacities of strip anchors in undrained clay with sloping ground surface are analyzed. Pull-out capacity and failure surface characteristics under different embedment ratios, undrained strength, inclined angles of slopes and weight of soil are studied. The results show that the superposition of gravity is not applicable to the case of sloping ground surface. The variation of slope angle has a significant impact on failure surface. The block set mechanism is based on a very simple concept which is integration and combination and can be a reference for the practical design.
Non-linear ultimate strength and stability limit state analysis of a wind turbine blade
DEFF Research Database (Denmark)
Rosemeier, Malo; Berring, Peter; Branner, Kim
2016-01-01
According to the design codes for wind turbine blades, it is sufficient to evaluate the blade's limit states using solely a linear analysis. This study, however, shows the need of non-linear analyses in blade design. Therefore, a geometrically non-linear structural response of a 34 m blade under...... flap-wise loading has been compared with a linear response to determine the blade's resistance in the ultimate strength and stability limit states. The linear analysis revealed an unrealistic failure mechanism and failure mode. Further, it did not capture the highly non-linear response of the blade...... of an imperfection. The more realistic non-linear approaches yielded more optimistic results than the mandatory linear bifurcation analysis. Consequently, the investigated blade designed after the lesser requirements was sufficient. Using the non-linear approaches, considering inter-fibre failure as the critical...
Plastic limit load analysis for steam generator tubes with local wall-thinning
International Nuclear Information System (INIS)
This paper introduces the study of experimental and numerical analysis for plastic limit loads of Inconel 690 steam generators (SG) tubes with local wall-thinning defects. Meanwhile, the effect of the three dimensions of a local wall-thinning defect on the plastic limit load of SG tubes is analyzed. A test facility which can test both burst pressure and plastic limit load of SG tubes was established and SG tubes with 3 typical types of defects were tested by using the facility. A regularization method for local wall-thinning defect is proposed and the finite element method was used to analyze the plastic limit load of SG tubes with defects. Compared with the experimental results of SG tubes with real defects, the calculated values of plastic limit load for SG tubes with regularized defects are conservative. Based on finite element method, the effect of the three dimensions of local wall-thinning defects on plastic limit loads of defected Inconel 690 SG tubes has been got. The studied results show that the defect depth of a local wall-thinning defect is the main factor influencing the plastic limit load of SG tubes, on the other hand, both the longitudinal length and the circumferential length of a defect have effect on the plastic limit load of SG tubes. It is found that in some cases, when the longitudinal length and the circumferential angle of a local wall-thinning defect exceed some extent, the effect of the longitudinal length and the circumferential angle on plastic limit load can be ignored.
A Step-wise Approach to the Determination of the Lower Limit of Analysis of the Calibration line
DEFF Research Database (Denmark)
Andersen, Jens Enevold Thaulov
2008-01-01
. residuals, the more favourable concentration range of calibration could be obtained by iteration using only but a few steps. This condition links the lower limit of analysis (LLA) to an upper limit of analysis (ULA), and thus completes the statistically appropriate extension of the calibration line......, preferably above 100, as to fulfil the conditions of the central-limit theorem....
Application of the limit analysis and of the reference stress method to stiffened welded structures
International Nuclear Information System (INIS)
A global method for the analysis of the failure of non elementary structures is examined. The type of failure are: instantaneous or delayed deformation, plastic instability of the material and delayed rupture. The steel structure studied is the lower support of a reactor core composed of two concentric rings, a bottom plate, a top plate and 15 stiffening radial plates. For calculation an annular sector representing 1/30 of this structure is modelized. The behaviour of the structure is examined for the following conditions: an instantaneous temperature rise from 4000C to 6500C, then the temperature is maintained for 400 hours and decreased from 6500 to 4000 at a rate of 0.2 degree/hour. The results obtained by elastic analysis, limit analysis and viscoplastic analysis are compared. The reference stress methods is reliable for the determination of structure dimensioning and is less expensive than the viscoplastic analysis. 35 drawings and 19 tables are given
Optical Limiting Properties of Ag-Cu Metal Alloy Nanoparticles Analysis by using MATLAB
International Nuclear Information System (INIS)
Ag-Cu alloy nanoparticles were formed by sequential ion implantation (Ag and Cu) in silica using a metal vapor vacuum arc (MEVVA) ion source. Third-order nonlinear optical properties of the nanoparticles were measured at 1064 nm excitations using the Z-scan technique. Curve fitting analysis, based on the MATLAB features for Ag-Cu alloy nanoparticle optical limiting experiments, is used. The results show that Ag-Cu alloy nanoparticles display a refractive optical limiting effect at 1064nm. (condensed matter: structure, mechanical and thermal properties)
Energy Technology Data Exchange (ETDEWEB)
Brisson, Michael
2013-06-03
At the time this article was written, new rulemakings were under consideration at OSHA and the U.S. Department of Energy (DOE) that would propose changes to occupational exposure limits for beryllium. Given these developments, it’s a good time to review the tools and methods available to IHs for assessing beryllium air and surface contamination in the workplace—what’s new and different, and what’s tried and true. The article discusses limit values and action levels for beryllium, problematic aspects of beryllium air sampling, sample preparation, sample analysis, and data evaluation.
International Nuclear Information System (INIS)
The accuracy, precision and determination limit were evaluated for determination of Al, As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Sb, Sc, Se, V and Zn in human head hair by instrumental neutron activation analysis. The precision was examined by analyzing human hair sample, and the results of relative standard deviations obtained ranged from 3.9 to 16.2%. The results accuracy was evaluated by using reference materials GBW 09101 Human Hair and NIES 5 Human Hair. Currie criterion was used for calculation of the determination limit. (author). 8 refs., 2 tabs
Limit analysis based on a modified elastic compensation method for nozzle-to-cylinder junctions
International Nuclear Information System (INIS)
To address the computational difficulties of the elastic compensation method (ECM) for complex structures such as nozzle-to-cylinder junctions, this paper develops a modified elastic compensation method (MECM). This method improves the precision of the ECM while preserving the advantages such as simplicity and high efficiency. Limit loads are calculated for three representative examples. The calculated solutions are compared with results from the elastic-plastic analysis method and the twice-elastic slope method. It is found that the MECM can provide a good estimation of plastic limit loads for complex structures
Performance analysis of optical burst switching node with limited wavelength conversion capabilities
Institute of Scientific and Technical Information of China (English)
XU Yi; SHI Kai-yuan; FAN Ge
2009-01-01
The systematical and scalable frameworks were provided for estimating the blocking probabilities under asynchronous traffic in optical burst switching (OBS) nodes with limited wavelength conversion capability (LWCC). The relevant system architectures of limited range and limited number of wavelength converters (WCs) deployed by a share-per-fiber (SPF) mode were developed, and the novel theoretical analysis of node blocking probability was derived by combining the calculation of discouraged arrival rate in a birth-death process and two-dimensional Markov chain model of SPF. The simulation results on single node performance verify the accuracy and effectiveness of the analysis models. Under most scenarios, it is difficult to distinguish the plots generated by the analysis and simulation. As the conversion degree increases, the accuracy of the analysis model worsens slightly. However, the utmost error on burst loss probability is far less than one order of magnitude and hence, still allows for an accurate estimate. Some results are of actual significance to the construction of next-generation commercial OBS backbones.
Towards Secure Distance Bounding
Boureanu, Ioana; Mitrokotsa, Aikaterini; Vaudenay, Serge
2013-01-01
Relay attacks (and, more generally, man-in-the-middle attacks) are a serious threat against many access control and payment schemes. In this work, we present distance-bounding protocols, how these can deter relay attacks, and the security models formalizing these protocols. We show several pitfalls making existing protocols insecure (or at least, vulnerable, in some cases). Then, we introduce the SKI protocol which enjoys resistance to all popular attack-models and features provable security....
Kahneman, Daniel
2002-01-01
The work cited by the Nobel committee was done jointly with the late Amos Tversky (1937-1996) during a long and unusually close collaboration. Together, we explored the psychology of intuitive beliefs and choices and examined their bounded rationality. This essay presents a current perspective on the three major topics of our joint work: heuristics of judgment, risky choice, and framing effects. In all three domains we studied intuitions - thoughts and preferences that come to mind quickly an...
Radially inhomogeneous bounded plasmas
Zakeri-Khatir, H.; Aghamir, F. M.
2016-07-01
On the basis of kinetic theory along with self-consistent field equations, the expressions for dielectric tensor of radially inhomogeneous magnetized plasma columns are obtained. The study of dielectric tensor characteristics allows the accurate analysis of the inhomogeneous properties, beyond limitations that exist in the conventional method. Through the Bessel–Fourier transformation, the localized form of material equations in a radially inhomogeneous medium are obtained. In order to verify the integrity of the model and reveal the effect of inhomogeneity, a special case of a cylindrical plasma waveguide completely filled with inhomogeneous magnetized cold plasma was considered. The dispersion relation curves for four families of electromagnetic (EH and HE) and electrostatic (SC and C) modes are obtained and compared with the findings of the conventional model. The numerical analysis indicates that the inhomogeneity effect leads to coupling of electromagnetic and electrostatic modes each having different radial eigen numbers. The study also reveals that the electrostatic modes are more sensitive to inhomogeneous effects than the electromagnetic modes.
New Bound on gamma from B^+- -> pi K Decays
Neubert, M.; Rosner, J. L.
1998-01-01
A bound on the angle gamma of the unitarity triangle is derived using experimental information on the CP-averaged branching ratios for the rare decays B^+- -> pi^+- K^0 and B^+- -> pi^0 K^+-. The theoretical description is cleaner than the Fleischer-Mannel analysis of the decays B^+- -> pi^+- K^0 and B^0 -> pi^-+ K^+- in that the two decay rates differ only in a single isospin amplitude, which has a simple structure in the SU(3) limit. As a consequence, electroweak penguin contributions and s...
Energy Technology Data Exchange (ETDEWEB)
N' Guessan, L.A.; Elifantz, H.; Nevin, K.P.; Mouser, P.J.; Methe, B.; Woodard, T. L.; Manley, K.; Williams, K. H.; Wilkins, M. J.; Larsen, J.T.; Long, P. E.; Lovley, D. R.
2009-09-01
Nutrient limitation is an environmental stress that may reduce the effectiveness of bioremediation strategies, especially when the contaminants are organic compounds or when organic compounds are added to promote microbial activities such as metal reduction. Genes indicative of phosphate-limitation were identified via microarray analysis of chemostat cultures of Geobacter sulfureducens. This analysis revealed that genes in the pst-pho operon, which is associated with a high affinity phosphate uptake system in other microorganisms, had significantly higher transcript abundance under phosphate-limiting conditions, with the genes pstB and phoU the most up-regulated. Quantitative PCR analysis of pstB and phoU transcript levels in G. sulfurreducens grown in chemostats demonstrated that the expression of these genes increased when phosphate was removed from the culture medium. Transcripts of pstB and phoU within the subsurface Geobacter species predominating during an in situ uranium bioremediation field experiment were more abundant than in chemostat cultures of G. sulfurreducens that were not limited for phosphate. Addition of phosphate to incubations of subsurface sediments did not stimulate dissimilatory metal reduction. The added phosphate was rapidly adsorbed onto the sediments. The results demonstrate that Geobacter species can effectively reduce U(VI) even when experiencing suboptimal phosphate concentrations and that increasing phosphate availability with phosphate additions is difficult to achieve due to the high reactivity of this compound. This transcript-based approach developed for diagnosing phosphate limitation should be applicable to assessing the potential need for additional phosphate in other bioremediation processes.
Collapse Scenarios of High-Rise Buildings Using Plastic Limit Analysis
Directory of Open Access Journals (Sweden)
G. Liu
2009-01-01
Full Text Available The Twin Towers of the World Trade Center (WTC in New York, USA collapsed on 11 September, 2001. The incident is regarded as the most severe disaster for high-rise buildings in history. Investigations into the collapse scenarios are still being conducted. Possible collapse scenarios assessed by local and international experts were reported. Another possible collapse scenario of the WTC based on two hypotheses was proposed in this paper, and the idea of plastic limit analysis was applied to evaluate the approximate limit load. According to the theory analysis and numerical calculations, a conclusion can be drawn that the large fires, aroused by the terrorist attack, play a significant role on the collapse of the WTC.
A Bound on Equipartition of Energy
Masi, Nicolo'
2011-01-01
In this article I want to demonstrate that the time-scale constraints for a thermodynamic system imply the new concept of equipartition of energy bound (EEB) or, more generally, a thermodynamical bound for the partition of energy. This means that I theorize and discuss the possibility to put an upper limit to the equipartition factor for a gas of particles. This could be interpreted as a sort of transcription of the entropy bounds from quantum-holographic sector. The number 4.93, i.e. the EEB, obtained from a comparison between the Margolus-Levitin quantum theorem and the TTT bound for relaxation times by Hod, seems like a special value for the thermodynamics of particle systems. This bound has been related to the idea of an extremal statistics and independently traced in a statistical mechanics framework. In fact, I identified a type of fluid that is capable of reaching to saturate the limit value I obtained for the equipartition factor. This was done by analyzing the mathematical behavior of the distributio...
A Ballistic Limit Analysis Program for Shielding Against Micrometeoroids and Orbital Debris
Ryan, Shannon; Christiansen, Erie
2010-01-01
A software program has been developed that enables the user to quickly and simply perform ballistic limit calculations for common spacecraft structures that are subject to hypervelocity impact of micrometeoroid and orbital debris (MMOD) projectiles. This analysis program consists of two core modules: design, and; performance. The design module enables a user to calculate preliminary dimensions of a shield configuration (e.g., thicknesses/areal densities, spacing, etc.) for a ?design? particle (diameter, density, impact velocity, incidence). The performance module enables a more detailed shielding analysis, providing the performance of a user-defined shielding configuration over the range of relevant in-orbit impact conditions.
Paulo B. Lourenço
2007-01-01
Continuum-based numerical methods have played a leading role in the numerical solution of problems in soil and rock mechanics. However, for stratified soils and fractured rocks, a continuum assumption often leads to difficult parameters to define and over-simplified geometry to be realistic. In such cases, approaches that consider the micro-structure of the material can be adopted. In this paper, two of such approaches are detailed, namely limit analysis incorporating fractures...
LIMITS OF SWOT ANALYSIS AND THEIR IMPACT ON DECISIONS IN EARLY WARNING SYSTEMS
Florin POPESCU; Cezar SCARLAT
2015-01-01
SWOT (strengths, weaknesses, opportunities, threats) analysis is useful in the decision-making process – crucial to any organization manager and/or strategist. This study aims to add value to the existing literature on SWOT, indicating its use and limitations, showing the need to link SWOT to other strategic tools and methodologies. As the current environment is turbulent and unpredictable, and economic cycles no longer comply with traditional rules, the precaution has become extremely i...
BOUNDING PYRAMIDS AND BOUNDING CONES FOR TRIANGULAR BEZIER SURFACES
Institute of Scientific and Technical Information of China (English)
Jian-song Deng; Fa-lai Chen; Li-li Wang
2000-01-01
This paper describes practical approaches on how to construct bounding pyramids and bounding cones for triangular Bézier surfaces. Examples are provided to illustrate the process of construction and comparison is made between various surface bounding volumes. Furthermore, as a starting point for the construction,we provide a way to compute hodographs of triangular Bézier surfaces and improve the algorithm for computing the bounding cone of a set of vectors.
Bounds to the conductivity of some two-component composites
Helsing, Johan
1993-02-01
Calculation of third-order bounds to the conductivity of isotropic two-component composites is discussed. Coincidence of the Beran bounds and bounds derived using trial fields based on the solution of a single-body electrostatic boundary-value problem is demonstrated for a random distribution of impenetrable ellipsoids. This extends a proof of Beasley and Torquato [J. Appl. Phys. 60, 3576 (1986)]. A structural parameter related to third-order bounds is calculated for a face-centered cubic array of cubes in a matrix. For an array of rectangular blocks an upper bound in one direction is derived. This bound, and its two-dimensional analogs, become very sharp in the limit of strong inhomogeneity. Improved third- and fourth-order bounds for the three-dimensional checkerboard are presented.
Universal bounds on current fluctuations
Pietzonka, Patrick; Barato, Andre C.; Seifert, Udo
2016-05-01
For current fluctuations in nonequilibrium steady states of Markovian processes, we derive four different universal bounds valid beyond the Gaussian regime. Different variants of these bounds apply to either the entropy change or any individual current, e.g., the rate of substrate consumption in a chemical reaction or the electron current in an electronic device. The bounds vary with respect to their degree of universality and tightness. A universal parabolic bound on the generating function of an arbitrary current depends solely on the average entropy production. A second, stronger bound requires knowledge both of the thermodynamic forces that drive the system and of the topology of the network of states. These two bounds are conjectures based on extensive numerics. An exponential bound that depends only on the average entropy production and the average number of transitions per time is rigorously proved. This bound has no obvious relation to the parabolic bound but it is typically tighter further away from equilibrium. An asymptotic bound that depends on the specific transition rates and becomes tight for large fluctuations is also derived. This bound allows for the prediction of the asymptotic growth of the generating function. Even though our results are restricted to networks with a finite number of states, we show that the parabolic bound is also valid for three paradigmatic examples of driven diffusive systems for which the generating function can be calculated using the additivity principle. Our bounds provide a general class of constraints for nonequilibrium systems.
A Novel Parametric Bound for Information Retrieval from Black Hole Radiation
Roy, Avik; Alvi, Mishkat Al; Majumdar, Mahbub; Matin, Md Abdul
2013-01-01
Hawking's argument about non-unitary evolution of black holes is often questioned on the ground that it doesn't acknowledge the quantum correlations in radiation process. However, recently it has been shown that adding `small' correction to leading order Hawking analysis, accounting for the correlations, doesn't help to restore unitarity. This paper generalizes the bound on entanglement entropy by relaxing the `smallness' condition and configures the parameters for possible recovery of information from an evaporating black hole. The new bound effectively puts an upper limit on increase in entanglement entropy. It also facilitates to relate the change in entanglement entropy to the amount of correction to Hawking state.
Guenter Goerigk; Sebastian Lages; Klaus Huber
2016-01-01
Anomalous small angle scattering measurements have been applied to diluted solutions of anionic polyacrylates decorated by specifically-interacting Pb2+ cations, revealing partial collapse of the polyacrylate into pearl-like subdomains with a size on the order of a few nanometers. From the pure-resonant scattering contribution of the Pb2+ cations, and from subsequent analysis of the resonant-invariant, the amount of Pb2+ cations condensed onto the polyanions with respect to the total amount o...
Optical Limiting Properties of Ag-Cu Metal Alloy Nanoparticles Analysis by using MATLAB
Institute of Scientific and Technical Information of China (English)
WANG Yu-Hua; LI Hui-Qing; LU Jian-Duo; WANG Ru-Wu
2011-01-01
Ag-Cu alloy nanoparticles were formed by sequential ion implantation (Ag and Cu) in silica using a metal vapor vacuum arc (MEVVA) ion source.Third-order nonlinear optical properties of the nanoparticles were measured at 1064nm excitations using the Z-scan technique.Curve fitting analysis,based on the MATLAB features for Ag-Cu alloy nanoparticle optical limiting experiments,is used.The results show that Ag-Cu alloy nanoparticles display a refractive optical limiting effect at 1064 nm.Recently,increasing attention has been focused on the third-order nonlinear susceptibility and the photorefractive effect of noble-metal clusters embedded in dielectric matrices.[1-3] Third-order nonlinearities of metal/dielectric composite materials are influenced not only by the type and size of the embedded metal clusters,but also by the dielectric constant,thermal conductivity and heat capacity of the dielectric matrices.[4-6] Amongst the nanoparticles studied earlier,high nonlinear absorption and nonlinear refraction coefficients were found in copper and copper containing nanomaterials.[7,8] For silver,the nonlinear refractive index γ changes from positive to negative upon the growth of clusters.[9] Potential applications of optical limiters in the protection of sensors from intense laser pulses have motivated great efforts to design new nonlinear optical systems.[10]%Ag-Cu alloy nanoparticles were formed by sequential ion implantation (Ag and Cu) in silica using a metal vapor vacuum arc (MEVVA) ion source. Third-order nonlinear optical properties of the nanoparticles were measured at 1064 nm excitations using the Z-scan technique. Curve fitting analysis, based on the MATLAB features for Ag-Cu alloy nanoparticle optical limiting experiments, is used. The results show that Ag-Cu alloy nanoparticles display a refractive optical limiting effect at 1064 nm.
Maldacena, Juan; Stanford, Douglas
2015-01-01
We conjecture a sharp bound on the rate of growth of chaos in thermal quantum systems with a large number of degrees of freedom. Chaos can be diagnosed using an out-of-time-order correlation function closely related to the commutator of operators separated in time. We conjecture that the influence of chaos on this correlator can develop no faster than exponentially, with Lyapunov exponent $\\lambda_L \\le 2 \\pi k_B T/\\hbar$. We give a precise mathematical argument, based on plausible physical assumptions, establishing this conjecture.
DEFF Research Database (Denmark)
Faupin, Jeremy; Møller, Jacob Schach; Skibsted, Erik
2011-01-01
We study regularity of bound states pertaining to embedded eigenvalues of a self-adjoint operator H, with respect to an auxiliary operator A that is conjugate to H in the sense of Mourre. We work within the framework of singular Mourre theory which enables us to deal with confined massless Pauli......–Fierz models, our primary example, and many-body AC-Stark Hamiltonians. In the simpler context of regular Mourre theory, our results boil down to an improvement of results obtained recently in [8, 9]....
Steinberg, Peter
2008-06-01
Who is the blog written by? Peter Steinberg is a nuclear physicist at the Brookhaven National Laboratory in New York, US. He is acting project manager of the PHOBOS experiment, which used Brookhaven's Relativistic Heavy Ion Collider (RHIC) to search for unusual events produced during collisions between gold nuclei. He is also involved with the PHENIX experiment, which seeks to discover a new state of matter known as the quark-gluon plasma. In addition to his own blog Entropy Bound, Steinberg is currently blogging on a website that was set up last year to publicize the involvement of US scientists with the Large Hadron Collider (LHC) at CERN.
Bounded Rationality and Tacit Knowledge in the Organizational Capabilities Approach
Foss, Nikolaj J.
2004-01-01
The famous three chapters in Nelson and Winter (1982) that focus on firm routines and capabilities are often taken to be solidly founded on an assumption of bounded rationality. I argue that, in actuality, bounded rationality plays a rather limited role in Nelson and Winter (1982), that the very different assumption of tacit knowledge is much more central, and that the links between bounded rationality and routines/capabilities are not clear. I then argue that the absence in Nelson and Winter...
Proof of a quantum Bousso bound
Bousso, Raphael; Casini, Horacio; Fisher, Zachary; Maldacena, Juan
2014-08-01
We prove the generalized covariant entropy bound, ΔS≤(A-A')/4Gℏ, for light-sheets with initial area A and final area A'. The entropy ΔS is defined as a difference of von Neumann entropies of an arbitrary state and the vacuum, with both states restricted to the light-sheet under consideration. The proof applies to free fields, in the limit where gravitational backreaction is small. We do not assume the null energy condition. In regions where it is violated, we find that the bound is protected by the defining property of light-sheets: that their null generators are nowhere expanding.
Proof of a Quantum Bousso Bound
Bousso, Raphael; Fisher, Zachary; Maldacena, Juan
2014-01-01
We prove the generalized Covariant Entropy Bound, $\\Delta S\\leq (A-A')/4G\\hbar$, for light-sheets with initial area $A$ and final area $A'$. The entropy $\\Delta S$ is defined as a difference of von Neumann entropies of an arbitrary state and the vacuum, with both states restricted to the light-sheet under consideration. The proof applies to free fields, in the limit where gravitational backreaction is small. We do not assume the null energy condition. In regions where it is violated, we find that the bound is protected by the defining property of light-sheets: that their null generators are nowhere expanding.
Naturalness bounds on gauge mediated soft terms
Ciafaloni, P; Ciafaloni, Paolo; Strumia, Alessandro
1996-01-01
After a general discussion about the quantitative meaning of the naturalness upper bounds on the masses of supersymmetric particles, we compute these bounds in models with gauge-mediated soft terms. We find interesting upper limits on the right-handed slepton masses that, unless the messenger fields are very light, disfavor minimal models with large messenger content. Deep unphysical minima, that however turn out to be non dangerous, are usually present in such models. The mu-problem can be solved by adding a light singlet only at the price of a large amount of fine tuning that gives also rise to heavy sparticles and large tan\\beta.
Novel Bounds on Marginal Probabilities
Mooij, Joris M.; Kappen, Hilbert J
2008-01-01
We derive two related novel bounds on single-variable marginal probability distributions in factor graphs with discrete variables. The first method propagates bounds over a subtree of the factor graph rooted in the variable, and the second method propagates bounds over the self-avoiding walk tree starting at the variable. By construction, both methods not only bound the exact marginal probability distribution of a variable, but also its approximate Belief Propagation marginal (``belief''). Th...
Tight Bernoulli tail probability bounds
Dzindzalieta, Dainius
2014-01-01
The purpose of the dissertation is to prove universal tight bounds for deviation from the mean probability inequalities for functions of random variables. Universal bounds shows that they are uniform with respect to some class of distributions and quantity of variables and other parameters. The bounds are called tight, if we can construct a sequence of random variables, such that the upper bounds are achieved. Such inequalities are useful for example in insurance mathematics, for constructing...
Analysis of limit forces on the vehicle wheels using an algorithm of Dynamic Square Method
Brukalski, M.
2016-09-01
This article presents a method named as Dynamic Square Method (DSM) used for dynamic analysis of a vehicle equipped with a four wheel drive system. This method allows determination of maximum (limit) forces acting on the wheels. Here, the maximum longitudinal forces acting on the wheels are assumed and then used to predict whether they can be achieved by a specific dynamic motion or whether the actual friction forces under a given wheel is large enough to transfer lateral forces. For the analysis of DSM a four wheel vehicle model is used. On the basis of this characteristic it is possible to determine the maximum longitudinal force acting on the wheels of the given axle depending on the lateral acceleration of the vehicle. The results of this analysis may be useful in the development of a control algorithm used for example in active differentials.
Error bounds for set inclusions
Institute of Scientific and Technical Information of China (English)
ZHENG; Xiyin(郑喜印)
2003-01-01
A variant of Robinson-Ursescu Theorem is given in normed spaces. Several error bound theorems for convex inclusions are proved and in particular a positive answer to Li and Singer's conjecture is given under weaker assumption than the assumption required in their conjecture. Perturbation error bounds are also studied. As applications, we study error bounds for convex inequality systems.
DEFF Research Database (Denmark)
Nielson, Hanne Riis; Nielson, Flemming
1992-01-01
they obtain a quadratic bound. These bounds are shown to be tight. Specializing the case of strict and additive functions to functionals of a form that would correspond to iterative programs they show that a linear bound is tight. This is related to several analyses studied in the literature (including...
Separable subgroups have bounded packing
Yang, Wen-yuan
2010-01-01
In this note, we prove that separable subgroups have bounded packing in ambient groups. The notion bounded packing was introduced by Hruska-Wise \\cite{HrWi} and in particular, our result confirms a conjecture in \\cite{HrWi} which states each subgroup of a virtually polycyclic group has the bounded packing property.
Adaptive selective ES-FEM limit analysis of cracked plane-strain structures
Institute of Scientific and Technical Information of China (English)
H. NGUYEN-XUAN[1; T. RABCZUK[2
2015-01-01
This paper presents a simple and efficient approach for predicting the plastic limit loads in cracked plane- strain structures. We use two levels of mesh repartitioning for the finite element limit analysis. The master level handles an adaptive primal-mesh process through a dissipation-based indicator. The slave level performs the subdivision of each triangle into three sub-triangles and constitutes a dual mesh from a pair of two adjacent sub-triangles shared by common edges of the primal mesh. Applying a strain smoothing projection to the strain rates on the dual mesh, the incompressibility constraint and the flow rule constraint are imposed over the edge-based smoothing domains and everywhere in the problem domain. The limit analysis problem is recast into the compact form of a second-order cone programming （SOCP） for the purpose of exploiting interior-point solvers. The present method retains a low number of optimization variables. It offers a convenient way for designing and solving the large-scale optimization problems effectively. Several benchmark examples are given to show the simplicity and effectiveness of the present method.
Consideration of tip speed limitations in preliminary analysis of minimum COE wind turbines
Cuerva-Tejero, A.; Yeow, T. S.; Lopez-Garcia, O.; Gallego-Castillo, C.
2014-12-01
A relation between Cost Of Energy, COE, maximum allowed tip speed, and rated wind speed, is obtained for wind turbines with a given goal rated power. The wind regime is characterised by the corresponding parameters of the probability density function of wind speed. The non-dimensional characteristics of the rotor: number of blades, the blade radial distributions of local solidity, twist, angle, and airfoil type, play the role of parameters in the mentioned relation. The COE is estimated using a cost model commonly used by the designers. This cost model requires basic design data such as the rotor radius and the ratio between the hub height and the rotor radius. Certain design options, DO, related to the technology of the power plant, tower and blades are also required as inputs. The function obtained for the COE can be explored to find those values of rotor radius that give rise to minimum cost of energy for a given wind regime as the tip speed limitation changes. The analysis reveals that iso-COE lines evolve parallel to iso-radius lines for large values of limit tip speed but that this is not the case for small values of the tip speed limits. It is concluded that., as the tip speed limit decreases, the optimum decision for keeping minimum COE values can be: a) reducing the rotor radius for places with high weibull scale parameter or b) increasing the rotor radius for places with low weibull scale parameter.
The question of an upper bound on entropy
International Nuclear Information System (INIS)
We discuss the possibility, and significance, of an upper bound on entropy in the light of the arguments of Bekenstein and Unruh and Wald. We obtain a stricter bound than Bekenstein does, and point out some limitations with regard to its significance. (author)
Matroidal Degree-Bounded Minimum Spanning Trees
Zenklusen, Rico
2011-01-01
We consider the minimum spanning tree (MST) problem under the restriction that for every vertex v, the edges of the tree that are adjacent to v satisfy a given family of constraints. A famous example thereof is the classical degree-constrained MST problem, where for every vertex v, a simple upper bound on the degree is imposed. Iterative rounding/relaxation algorithms became the tool of choice for degree-bounded network design problems. A cornerstone for this development was the work of Singh and Lau, who showed for the degree-bounded MST problem how to find a spanning tree violating each degree bound by at most one unit and with cost at most the cost of an optimal solution that respects the degree bounds. However, current iterative rounding approaches face several limits when dealing with more general degree constraints. In particular, when several constraints are imposed on the edges adjacent to a vertex v, as for example when a partition of the edges adjacent to v is given and only a fixed number of elemen...
Directory of Open Access Journals (Sweden)
Igor Albertovich Brigadnov
2012-08-01
Full Text Available The problem of minimization of ill-conditioned functions is considered. This problem arises as a result of finite-element approximation of the limit analysis problem for dielectrics in powerful electric fields. The objective function is nonsmooth therefore a smooth regularization of finite-dimensional problem is used. As a result distinct ravine of objective function is acquired. Convergence of the gradient and the heave-ball methods in relation to its internal and optimization parameters are studied inside the numerical computing environment and fourth-generation programming language Matlab.
Analysis of FEL-based CeC amplification at high gain limit
International Nuclear Information System (INIS)
An analysis of Coherent electron Cooling (CeC) amplifier based on 1D Free Electron Laser (FEL) theory was previously performed with exact solution of the dispersion relation, assuming electrons having Lorentzian energy distribution. At high gain limit, the asymptotic behavior of the FEL amplifier can be better understood by Taylor expanding the exact solution of the dispersion relation with respect to the detuning parameter. In this work, we make quadratic expansion of the dispersion relation for Lorentzian energy distribution and investigate how longitudinal space charge and electrons@@@ energy spread affect the FEL amplification process.
Simulation and analytic analysis of radiation driven islands at the density limit
Brennan, D. P.; Liu, C.; Gates, D. A.; Delgado-Aparicio, L.; White, R.
2014-10-01
The effect of radiative cooling on the onset and evolution of magnetic islands is investigated with nonlinear resistive MHD simulations and reduced theoretical analysis. The configuration is a cylindrical tokamak with a m/n = 2/1 island and includes three dimensional resistivity and anisotropic heat conduction in the simulations. The radiative cooling is implemented as a temperature perturbation inside the island, which modifies the island structure and drives the island more unstable. Analytic reduction of the saturated island size and structure supports the simulation results. The results offer intuitive understanding of experimental observations of radiation driven magnetic islands, which may explain density limit disruptions.
Analysis of limited-diffractive and limited-dispersive X-waves generated by finite radial waveguides
Fuscaldo, Walter; Pavone, Santi C.; Valerio, Guido; Galli, Alessandro; Albani, Matteo; Ettorre, Mauro
2016-05-01
In this work, we analyze the spatial and temporal features of electromagnetic X-waves propagating in free space and generated by planar radiating apertures. The performance of ideal X-waves is discussed and compared to practical cases where the important effects related to the finiteness of the radiating aperture and the wavenumber dispersion are taken into account. In particular, a practical device consisting of a radial waveguide loaded with radiating slots aligned along a spiral path is considered for the practical case in the millimeter-wave range. A common mathematical framework is defined for a precise comparison of the spatiotemporal properties and focusing capabilities of the generated X-wave. It is clearly shown that the fractional bandwidth of the radiating aperture has a key role in the longitudinal confinement of an X-wave in both ideal and practical cases. In addition, the finiteness of the radiating aperture as well as the wavenumber dispersion clearly affect both the transverse and the longitudinal profiles of the generated radiation as it travels beyond the depth-of-field of the generated X-wave. Nevertheless, the spatiotemporal properties of the X-wave are preserved even in this "dispersive-finite" case within a defined region and duration related to the nondiffractive range and fractional bandwidth of the spectral components of the generated X-wave. The proposed analysis may open new perspectives for the efficient generation of X-waves over finite radiating apertures at millimeter waves where the dispersive behavior of realistic devices is no longer negligible.
Li, Zheng; Wang, Junhong; Duan, Jianjie; Zhang, Zhan; Chen, Meie
2016-03-18
In this paper the radiation property of the one-dimensional periodic leaky-wave structure is analysed using a new hybrid method, which involves the mode expansion method for expanding the periodic aperture field in terms of spatial harmonics and the method of effective radiation sections for transforming the expanded fields into far fields. Using this method, the radiation of each spatial harmonic can be achieved, and the contributions of the harmonics (especially the bounded modes) to the total radiation of the periodic leaky-wave structure can be calculated. The main findings in this paper demonstrate that the bounded modes in a finite length structure have obvious contribution to the far-field radiation, which was considered to be non-radiative and always ignored in the conventional researches.
Nowak, K.; Kästner, M.; Miltner, A.
2009-04-01
During degradation of organic pollutants in soil, metabolites, microbial biomass, CO2and "bound" residues ("non-extractable" residues in soil organic matter) are formed. Enhanced transformation of these contaminants into "bound" residues has been proposed as an alternative remediation method for polluted soils. However, this kind of residues may pose a potential risk for the environment due to their chemical structure and possible remobilization under different conditions. Therefore particular attention is given actually to "bound" residues. Part of these non-extractable residues may be "biogenic," because microorganisms use the carbon from the pollutant to form their biomass components (fatty acids, amino acids, amino sugars), which subsequently may be incorporated into soil organic matter. Furthermore, the CO2 originating from mineralization of xenobiotics, can be re-assimilated by microorganisms and also incorporated into "biogenic residue". The hazard posed by "bound" residues may be overestimated because they are "biogenic" (contain microbial fatty acids and amino acids). The knowledge about the pathways of "biogenic residue" formation is necessary for a proper assessment of the fate of tested pollutants and their turnover in the soil environment. Moreover, these data are needed to establish the realistic degradation rates of the contaminants in soil. The main objectives of this study are: to quantify the extent of "biogenic residue" (fatty acids, amino acids, amino sugars) formation during the degradation of a model pollutant (2,4-dichlorophenoxyacetic acid = 2,4-D) and during CO2 assimilation by microorganisms and to evaluate which components are mainly incorporated into "bound" residues. To investigate the extent of "biogenic residue" formation in soil during the degradation of 2,4-D, experiments with either 14C-U-ring and 13C6-2,4-D or carboxyl-14C 2,4-D were performed. The incubation experiments were performed according to OECD test guideline 307, in the
International Nuclear Information System (INIS)
Peptide deformylase (PDF) from B. cereus has been overexpressed, purified and crystallized in ligand-free and actinonin-bound forms. Diffraction data have been collected from these crystals to 1.7 and 2.0 Å resolution, respectively. In bacteria, protein expression initiates with an N-formyl group and this needs to be removed in order to ensure proper bacterial growth. These formylation and deformylation processes are unique to eubacteria; therefore, inhibition of these would provide a novel antibacterial therapy. Deformylation is carried out by peptide deformylase (PDF). PDF from Bacillus cereus, one of the major pathogenic bacteria, was cloned into expression plasmid pET-28a (Novagen), overexpressed in Escherichia coli BL21 (DE3) and purified to high quality. Crystals have been obtained of both ligand-free PDF and PDF to which actinonin, a highly potent naturally occurring inhibitor, is bound. Both crystals belong to space group P212121, with unit-cell parameters a = 42.72, b = 44.04, c = 85.19 Å and a = 41.31, b = 44.56, c = 84.47 Å, respectively. Diffraction data were collected to 1.7 Å resolution for the inhibitor-free crystals and to 2.0 Å resolution for the actinonin-bound crystals
Analysis of the NTPDase and ecto-5'-nucleotidase profiles in serum-limited Trichomonas vaginalis
Directory of Open Access Journals (Sweden)
Amanda Piccoli Frasson
2012-03-01
Full Text Available Trichomonas vaginalis is a parasite of the human urogenital tract that causes trichomonosis, the most prevalent non-viral sexually transmitted disease. Ectonucleoside triphosphate diphosphohydrolase (NTPDase family members, which hydrolyse extracellular ATP and ADP and ecto-5′-nucleotidase, which hydrolyses AMP, have been characterised in T. vaginalis. For trichomonad culture, the growth medium is supplemented with 10% serum, which is an important source of nutrients, such as adenosine. Here, we investigated the ATP metabolism of T. vaginalis trophozoites from long-term cultures and clinical isolates under limited bovine serum conditions (1% serum. The specific enzymatic activities were expressed as nmol inorganic phosphate (Pi released/min/mg protein, the gene expression patterns were determined by reverse transcriptase-polymerase chain reaction, the extracellular adenine nucleotide hydrolysis was analysed by high performance liquid chromatography and the cell cycle analysis was assessed by flow cytometry. Serum limitation led to the profound activation of NTPDase and ecto-5'-nucleotidase activities. Furthermore, the levels of NTPDase A and B transcripts increased and extracellular ATP metabolism was activated, which led to enhanced ATP hydrolysis and the formation of ADP and AMP. Moreover, the cell cycle was arrested at the G0/G1 stage, which suggested adenosine uptake. Our data suggest that under conditions of serum limitation, NTPDase and ecto-5'-nucleotidase play a role in providing the adenosine required for T. vaginalis growth and that this process contributes to the establishment of parasitism.
Directory of Open Access Journals (Sweden)
Radha Rajasingham
Full Text Available BACKGROUND: Cryptococcal meningitis (CM is the most common form of meningitis in Africa. World Health Organization guidelines recommend 14-d amphotericin-based induction therapy; however, this is impractical for many resource-limited settings due to cost and intensive monitoring needs. A cost-effectiveness analysis was performed to guide stakeholders with respect to optimal CM treatment within resource limitations. METHODS AND FINDINGS: We conducted a decision analysis to estimate the incremental cost-effectiveness ratio (ICER of six CM induction regimens: fluconazole (800-1,200 mg/d monotherapy, fluconazole + flucytosine (5FC, short-course amphotericin (7-d + fluconazole, 14-d of amphotericin alone, amphotericin + fluconazole, and amphotericin + 5FC. We computed actual 2012 healthcare costs in Uganda for medications, supplies, and personnel, and average laboratory costs for three African countries. A systematic review of cryptococcal treatment trials in resource-limited areas summarized 10-wk survival outcomes. We modeled one-year survival based on South African, Ugandan, and Thai CM outcome data, and survival beyond one-year on Ugandan and Thai data. Quality-adjusted life years (QALYs were determined and used to calculate the cost-effectiveness ratio and ICER. The cost of hospital care ranged from $154 for fluconazole monotherapy to $467 for 14 d of amphotericin + 5FC. Based on 18 studies investigating outcomes for HIV-infected individuals with CM in resource-limited settings, the estimated mean one-year survival was lowest for fluconazole monotherapy, at 40%. The cost-effectiveness ratio ranged from $20 to $44 per QALY. Overall, amphotericin-based regimens had higher costs but better survival. Short-course amphotericin (1 mg/kg/d for 7 d with fluconazole (1,200 mg/d for14 d had the best one-year survival (66% and the most favorable cost-effectiveness ratio, at $20.24/QALY, with an ICER of $15.11 per additional QALY over fluconazole
A new type of sharp bounds for ratios of modified Bessel functions
Ruiz-Antolin, D.; J. Segura
2016-01-01
The bounds for the ratios of first and second kind modified Bessel functions of consecutive orders are important quantities appearing in a large number of scientific applications. We obtain new bounds which are accurate in a large region of parameters and which are shaper than previous bounds. The new bounds are obtained by a qualitative analysis of the Riccati equation satisfied by these ratios. A procedure is considered in which the bounds obtained from the analysis of the Riccati equation ...
Theoretical analysis of saturation and limit cycles in short pulse FEL oscillators
Energy Technology Data Exchange (ETDEWEB)
Piovella, N.; Chaix, P.; Jaroszynski, D. [Commissariat a l`Energie Atomique, Bruyeres-le-Chatel (France)] [and others
1995-12-31
We derive a model for the non linear evolution of a short pulse oscillator from low signal up to saturation in the small gain regime. This system is controlled by only two independent parameters: cavity detuning and losses. Using a closure relation, this model reduces to a closed set of 5 non linear partial differential equations for the EM field and moments of the electron distribution. An analysis of the linearised system allows to define and calculate the eigenmodes characterising the small signal regime. An arbitrary solution of the complete nonlinear system can then be expanded in terms of these eigenmodes. This allows interpreting various observed nonlinear behaviours, including steady state saturation, limit cycles, and transition to chaos. The single mode approximation reduces to a Landau-Ginzburg equation. It allows to obtain gain, nonlinear frequency shift, and efficiency as functions of cavity detuning and cavity losses. A generalisation to two modes allows to obtain a simple description of the limit cycle behaviour, as a competition between these two modes. An analysis of the transitions to more complex dynamics is also given. Finally, the analytical results are compared to the experimental data from the FELIX experiment.
Silver, R Angus
2003-12-15
Synapses are a key determinant of information processing in the central nervous system. Investigation of the mechanisms underlying synaptic transmission at central synapses is complicated by the inaccessibility of synaptic contacts and the fact that their temporal dynamics are governed by multiple parameters. Multiple-probability fluctuation analysis (MPFA) is a recently developed method for estimating quantal parameters from the variance and mean amplitude of evoked steady-state synaptic responses recorded under a range of release probability conditions. This article describes the theoretical basis and the underlying assumptions of MPFA, illustrating how a simplified multinomial model can be used to estimate mean quantal parameters at synapses where quantal size and release probability are nonuniform. Interpretations of the quantal parameter estimates are discussed in relation to uniquantal and multiquantal models of transmission. Practical aspects of this method are illustrated including a new method for estimating quantal size and variability, approaches for optimising data collection, error analysis and a method for identifying multivesicular release. The advantages and limitations of investigating synaptic function with MPFA are explored and contrasted with those for traditional quantal analysis and more recent optical quantal analysis methods.
Jiao, Yi
2016-01-01
In a diffraction-limited storage ring (DLSR), the momentum acceptance (MA) might be limited by the half integer resonances (HIRs) excited by focusing errors, associated with the large detuning terms from the strong focusing and strong sextupoles required for an ultralow emittance. Taking the High Energy Photon Source (HEPS) as an example and through statistical analysis, we found that the horizontal HIRs have stronger impact on dynamics than the vertical ones; and the probability of MA reduction caused by a HIR is closely correlated with the level of the beta beats at the same plane, but independent of the error sources. For the HEPS design, to reach a small MA-reduction probability of about 1%, the rms amplitude of the beta beats at the nominal tunes should be kept below 1.5% horizontally and 2.5% vertically. The presented analysis can provide useful reference for other DLSR designs.
Jolly, William H.
1992-01-01
Relationships defining the ballistic limit of Space Station Freedom's (SSF) dual wall protection systems have been determined. These functions were regressed from empirical data found in Marshall Space Flight Center's (MSFC) Hypervelocity Impact Testing Summary (HITS) for the velocity range between three and seven kilometers per second. A stepwise linear least squares regression was used to determine the coefficients of several expressions that define a ballistic limit surface. Using statistical significance indicators and graphical comparisons to other limit curves, a final set of expressions is recommended for potential use in Probability of No Critical Flaw (PNCF) calculations for Space Station. The three equations listed below represent the mean curves for normal, 45 degree, and 65 degree obliquity ballistic limits, respectively, for a dual wall protection system consisting of a thin 6061-T6 aluminum bumper spaced 4.0 inches from a .125 inches thick 2219-T87 rear wall with multiple layer thermal insulation installed between the two walls. Normal obliquity is d(sub c) = 1.0514 v(exp 0.2983 t(sub 1)(exp 0.5228). Forty-five degree obliquity is d(sub c) = 0.8591 v(exp 0.0428) t(sub 1)(exp 0.2063). Sixty-five degree obliquity is d(sub c) = 0.2824 v(exp 0.1986) t(sub 1)(exp -0.3874). Plots of these curves are provided. A sensitivity study on the effects of using these new equations in the probability of no critical flaw analysis indicated a negligible increase in the performance of the dual wall protection system for SSF over the current baseline. The magnitude of the increase was 0.17 percent over 25 years on the MB-7 configuration run with the Bumper II program code.
Bounding the Higgs width at the LHC: complementary results from H→WW
Energy Technology Data Exchange (ETDEWEB)
Campbell, John M.; Ellis, R. Keith; Williams, Ciaran
2014-03-01
We investigate the potential of the process gg → H→ WW to provide bounds on the Higgs width. Recent studies using off-shell H→ ZZ events have shown that Run 1 LHC data can constrain the Higgs width, $\\Gamma_H < (25-45) \\Gamma_{H}^{\\rm SM}$. Using 20 fb-1 of 8 TeV ATLAS data, we estimate a bound on the Higgs boson width from the WW channel between $\\Gamma_H < (100-500) \\Gamma_H^{SM}$. The large spread in limits is due to the range of cuts applied in the existing experimental analysis. The stricter cuts designed to search for the on-shell Higgs boson limit the potential number of off-shell events, weakening the constraints. As some of the cuts are lifted the bounds improve. We show that there is potential in the high transverse mass region to produce upper bounds of the order of $(25-50) \\Gamma_H^{SM}$, depending strongly on the level of systematic uncertainty that can be obtained. Thus, if these systematics can be controlled, a constraint on the Higgs boson width from the H → WW$ decay mode can complement a corresponding limit from H → ZZ.
Lower bounds for designs in symmetric spaces
Eidelstein, Noa
2010-01-01
We prove lower bounds on designs in spaces with a large group of symmetries. These spaces include globally symmetric Riemannian spaces (of any rank) and commutative association schemes with 1-transitive group of symmetries. Our bounds are, in general, implicit, relying on estimates on the spectral behavior of certain symmetry-invariant linear operators. They reduce to the first linear programming bound for designs in globally symmetric Riemannian spaces of rank 1 or in distance regular graphs. The proofs are different though, coming from viewpoint of abstract harmonic analysis in symmetric spaces. As a dividend we obtain the following geometric fact: a design is large because a union of "spherical caps" around its points "covers" the whole space.
Analysis of safety limits of the Moroccan TRIGA MARK II research reactor
International Nuclear Information System (INIS)
A 2 MW TRIGA MARK II research reactor has been designed by General Atomics (GA) for the National Centre for Energy and Nuclear Sciences and Techniques (CNESTEN) in Morocco. This TRIGA reactor has the particularity of being the only TRIGA reactor designed to operate at the power level of 2 MW with the use of natural convection cooling. The main objective of this study is to check the ability of the reactor to operate at its nominal power with sufficient safety margins. The analysis of the reactor core starts from the basic reactor cells calculations which were performed for all the reactor cells using the LEOPARD code. The zone averaged group constants provided by cell calculations are used to compute the multiplication factor keff of the cold and clean core using the diffusion theory code Mcrac which is a recent version of the earlier code EXTERMINATOR-2. The main objective of the core calculations is to predict the core excess reactivity in cold zero power conditions and the power peaking factors which are very important data for the thermal hydraulic analysis of the core. For the maximum power peaking factors, our results agree with the values given by the reactor designer. Concerning the core excess reactivity, our results from both XY and RZ core calculations models lead to higher values than the results given by GA (about +2000 pcm). However, we should mention that GA results correspond probably to the minimum core excess reactivity which is guaranteed. The thermal hydraulic analysis of the TRIGA core was performed using the French code FLICA developed in CEA/Saclay for transient and study state thermal hydraulic analysis of a large variety of reactor cores. The objective of this analysis is to evaluate the main safety related parameters of the core and to ensure that they are within the safety limits in any operating conditions. The parameters considered in our study are: maximum fuel temperature, minimum DNBR and maximum void fraction. The obtained results
Tromson-Carli, A.; Svob, L.; Marfaing, Y.; Druilhe, R.; Desjonqueres, F.; Triboulet, R.
1991-12-01
X-ray double diffraction and photoluminescence experiments were performed on a series of CdTe layers grown by MOVPE on CdTe, CdZnTe and GaAs substrates. Some correlation appears between the measured rocking curve widths and impurity-bound exciton linewidth. To analyze these results, a model relating the exciton linewidth to the average strain induced by an array of random dislocations has been developed. It appears that X-ray diffraction is also sensitive to non-random dislocation configurations which do not affect luminescence linewidth.
Bounded Rationality in Transposition Processes
DEFF Research Database (Denmark)
Vollaard, Hans; Martinsen, Dorte Sindbjerg
2014-01-01
that concerns the organisation and financing of national healthcare systems. This article applies the perspective of bounded rationality to explain (irregularities in) the timely and correct transposition of EU directives. The cognitive and organisational constraints long posited by the bounded rationality...... perspective may affect the commonly employed explanatory factors of administrative capacities, misfit and the heterogeneity of preferences among veto players. To prevent retrospective rationalisation of the transposition process, this paper traces this process as it unfolded in Denmark and the Netherlands....... As bounded rationality is apparent in the transposition processes in these relatively well-organised countries, future transposition studies should devote greater consideration to the bounded rationality perspective....
International Nuclear Information System (INIS)
This report starts with a brief description of the computer system used in Grafenrheinfeld for limiting the power density in the reactor core (DNB-Module) and is then followed by a discussion on methods for verification of the systems' software. The different language levels on which analysis may be performed are presented and criteria for choosing the appropriate language level with regard to verification are given. The program analysis splits the software into sections which are manageable and testable. Then the detailed structure of control flow and data flow as well as the functional properties of these sections are investigated. On certain premises completely analysed sections can be regarded as errorfree, i.e. their failure probability can be assumed to be zero. In addition, test cases for the various software sections are established on the basis of the program analysis. The test strategy comprises the module (sectional) test, partially performed with the test cases mentioned above, as well as an integration test of the entire DNB software. Both tests may be performed automatically - the test embedment is already established to a certain extent - thus allowing execution of a great number of tests; a feature which is extremely important in view of an assessment of quantitative software parameters. (orig.)
Thermodynamic Upper Bound on Broadband Light Coupling with Photonic Structures
Yu, Zongfu
2012-10-01
The coupling between free space radiation and optical media critically influences the performance of optical devices. We show that, for any given photonic structure, the sum of the external coupling rates for all its optical modes are subject to an upper bound dictated by the second law of thermodynamics. Such bound limits how efficient light can be coupled to any photonic structure. As one example of application, we use this upper bound to derive the limit of light absorption in broadband solar absorbers. © 2012 American Physical Society.
Institute of Scientific and Technical Information of China (English)
Qian Xuede
2008-01-01
Excessive leachate levels in landfills can be a major triggering mechanism for translational failure. The scope of this paper is to present the development of the calculation methods for limit equilibrium analysis of translational failure of landfills and the effects of parametric variation on the factor of safety (FS) of landfills under different leachate buildup conditions. During the development of the calculation methods, 4 leachate buildup conditions are considered. The FS for an interface with high friction angle and low apparent cohesion generally drops much more quickly when leachate levels are increased than that for an interface under inverse conditions. The critical interface of a muitilayer liner system with the lowest FS for the entire waste mass can shift from one to another with changes in the leachate levels. The different interfaces of a multilayer liner will have different FS-values under different leachate buildup conditions.
Analysis of an Arctic sea ice loss model in the limit of a discontinuous albedo
Hill, Kaitlin; Silber, Mary
2015-01-01
As Arctic sea ice extent decreases with increasing greenhouse gases, there is a growing interest in whether there could be a bifurcation associated with its loss, and whether there is significant hysteresis associated with that bifurcation. A challenge in answering this question is that the bifurcation behavior of certain Arctic energy balance models have been shown to be sensitive to how ice-albedo feedback is parameterized. We analyze an Arctic energy balance model in the limit as a smoothing parameter associated with ice-albedo feedback tends to zero, which makes the system piecewise-smooth. Our analysis provides a case study where we use the piecewise-smooth system to explore bifurcation behavior of the smooth system. In this case study, we demonstrate that certain qualitative bifurcation behaviors of the smooth system can have nonsmooth counterparts. We use this perspective to systematically search parameter space. For example, we uncover parameter sets for which the largest transition, with increasing g...
Continuous limit of a crowd motion and herding model: Analysis and numerical simulations
Pietschmann, Jan-Frederik
2011-11-01
In this paper we study the continuum limit of a cellular automaton model used for simulating human crowds with herding behaviour. We derive a system of non-linear partial differential equations resembling the Keller-Segel model for chemotaxis, however with a non-monotone interaction. The latter has interesting consequences on the behaviour of the model\\'s solutions, which we highlight in its analysis. In particular we study the possibility of stationary states, the formation of clusters and explore their connection to congestion. We also introduce an efficient numerical simulation approach based on an appropriate hybrid discontinuous Galerkin method, which in particular allows flexible treatment of complicated geometries. Extensive numerical studies also provide a better understanding of the strengths and shortcomings of the herding model, in particular we examine trapping effects of crowds behind nonconvex obstacles. © American Institute of Mathematical Sciences.
Left ventricular time volume curve analysis in the detection of limited ischaemic heart disease
International Nuclear Information System (INIS)
The aim of the study was to determine whether limited coronary artery disease (CAD) could be accurately detected using the Cardiac Gated Blood Pool (CGBP) scan with exercise. Regional left ventricular time volume curves (RLTVD) were generated from 52 studies (46 patients: 22 normals, 24 abnormals). The parameters assessed both globally and regionally and at rest (R) and exercise (Ex) were: (1) the ejection fraction (EF) (2) the change in ejection fraction from R to Ex (δEF) (3) an early contraction index (ECI) (4) a maximal emptying index (DR) and (5) a maximal refilling index (AR). After careful analysis of these parameters it was decided that our diagnostic criteria would rely on the following: (1) the EF at R and Ex (2) the δ EF (3) the ECI at Ex (4) the AR at Ex This study showed that both the sensitivity and the specificity of the CGBP scan can be improved considerably with the inclusion of RLTVC from the levels obtained when the EF parameters alone are considered. It is possible with this technique to accurately diagnose limited CAD. (Author)
International Nuclear Information System (INIS)
In this paper study of the Saturated Iron Core Superconducting Fault Current Limiter (SISFCL) has been carried out. Since in an SISFCL, the iron core plays a key role in distributing the magnetic flux, the hysteresis property of the core material has been introduced in a mathematical model to get a more accurate result. In this paper the Jiles–Atherton hysteresis model has been used for modeling the core. The equations are solved through numerical method and performances of SISFCL are analyzed for both normal and fault conditions. On further analysis it is observed that for suppression of higher value of fault current a high voltage develops across the DC source. Hence there is a chance of the DC source being damaged by the rise in voltage under fault condition. In order to protect the DC source, a shorted ring is introduced in the SISFCL circuit and its effects have been analyzed. It is noticed that the shorted ring has successfully reduced the voltage across the DC coil during fault condition while the performance of the limiter remains the same. - Highlights: • Mathematical modeling of SISFCL has been established. • Hysteresis effect has been included using J–A model. • Mathematical model of SISFCL using the Shorted Ring have been established. • Comparisons are drawn between the responses with and without shorted ring
Analysis of Optical CDMA Signal Transmission: Capacity Limits and Simulation Results
Directory of Open Access Journals (Sweden)
Lawrence R. Chen
2005-06-01
Full Text Available We present performance limits of the optical code-division multiple-access (OCDMA networks. In particular, we evaluate the information-theoretical capacity of the OCDMA transmission when single-user detection (SUD is used by the receiver. First, we model the OCDMA transmission as a discrete memoryless channel, evaluate its capacity when binary modulation is used in the interference-limited (noiseless case, and extend this analysis to the case when additive white Gaussian noise (AWGN is corrupting the received signals. Next, we analyze the benefits of using nonbinary signaling for increasing the throughput of optical CDMA transmission. It turns out that up to a fourfold increase in the network throughput can be achieved with practical numbers of modulation levels in comparison to the traditionally considered binary case. Finally, we present BER simulation results for channel coded binary and M-ary OCDMA transmission systems. In particular, we apply turbo codes concatenated with Reed-Solomon codes so that up to several hundred concurrent optical CDMA users can be supported at low target bit error rates. We observe that unlike conventional OCDMA systems, turbo-empowered OCDMA can allow overloading (more active users than is the length of the spreading sequences with good bit error rate system performance.
International Nuclear Information System (INIS)
Adenylate kinase (AK) from D. gigas was purified and crystallized in three different metal-bound forms: Zn2+–AK, Co2+–AK and Fe2+–AK. Adenylate kinase (AK; ATP:AMP phosphotransferase; EC 2.7.4.3) is involved in the reversible transfer of the terminal phosphate group from ATP to AMP. AKs contribute to the maintenance of a constant level of cellular adenine nucleotides, which is necessary for the energetic metabolism of the cell. Three metal ions, cobalt, zinc and iron(II), have been reported to be present in AKs from some Gram-negative bacteria. Native zinc-containing AK from Desulfovibrio gigas was purified to homogeneity and crystallized. The crystals diffracted to beyond 1.8 Å resolution. Furthermore, cobalt- and iron-containing crystal forms of recombinant AK were also obtained and diffracted to 2.0 and 3.0 Å resolution, respectively. Zn2+–AK and Fe2+–AK crystallized in space group I222 with similar unit-cell parameters, whereas Co2+–AK crystallized in space group C2; a monomer was present in the asymmetric unit for both the Zn2+–AK and Fe2+–AK forms and a dimer was present for the Co2+–AK form. The structures of the three metal-bound forms of AK will provide new insights into the role and selectivity of the metal in these enzymes
Echeverria, Alex; Mendez, Rene A; Orchard, Marcos
2016-01-01
Context. The best precision that can be achieved to estimate the location of a stellar-like object is a topic of permanent interest in the astrometric community. Aims. We analyse bounds for the best position estimation of a stellar-like object on a CCD detector array in a Bayesian setting where the position is unknown, but where we have access to a prior distribution. In contrast to a parametric setting where we estimate a parameter from observations, the Bayesian approach estimates a random object (i.e., the position is a random variable) from observations that are statistically dependent on the position. Methods. We characterize the Bayesian Cramer-Rao (CR) that bounds the minimum mean square error (MMSE) of the best estimator of the position of a point source on a linear CCD-like detector, as a function of the properties of detector, the source, and the background. Results. We quantify and analyse the increase in astrometric performance from the use of a prior distribution of the object position, which is ...
Limit analysis of supporting pressure in tunnels with regard to surface settlement
Institute of Scientific and Technical Information of China (English)
杨小礼; 覃长兵
2015-01-01
The proliferation of Hoek-Brown nonlinear failure criterion and upper bound theorem makes it possible to evaluate the stability of circular tunnels with an original curved collapsing mechanism. The arch effect of shallow circle tunnel is not taken into consideration so that the mechanical characteristics can be easily described. Based on the mechanism, the upper bound solution of supporting pressure of tunnels under the condition of surface settlements and overloads on the ground surface is derived. The objective function is formed from virtual work equations under the variational principle, and solutions are presented by the optimum theory. Comparisons with previous works are made. The numerical results of the present method show great agreement with those of existing ones. With regard to the surface settlement and overloads, the influence of different rock parameters on the collapsing shape is analyzed.
Bounds for Asian basket options
Deelstra, Griselda; Diallo, Ibrahima; Vanmaele, Michèle
2008-09-01
In this paper we propose pricing bounds for European-style discrete arithmetic Asian basket options in a Black and Scholes framework. We start from methods used for basket options and Asian options. First, we use the general approach for deriving upper and lower bounds for stop-loss premia of sums of non-independent random variables as in Kaas et al. [Upper and lower bounds for sums of random variables, Insurance Math. Econom. 27 (2000) 151-168] or Dhaene et al. [The concept of comonotonicity in actuarial science and finance: theory, Insurance Math. Econom. 31(1) (2002) 3-33]. We generalize the methods in Deelstra et al. [Pricing of arithmetic basket options by conditioning, Insurance Math. Econom. 34 (2004) 55-57] and Vanmaele et al. [Bounds for the price of discrete sampled arithmetic Asian options, J. Comput. Appl. Math. 185(1) (2006) 51-90]. Afterwards we show how to derive an analytical closed-form expression for a lower bound in the non-comonotonic case. Finally, we derive upper bounds for Asian basket options by applying techniques as in Thompson [Fast narrow bounds on the value of Asian options, Working Paper, University of Cambridge, 1999] and Lord [Partially exact and bounded approximations for arithmetic Asian options, J. Comput. Finance 10 (2) (2006) 1-52]. Numerical results are included and on the basis of our numerical tests, we explain which method we recommend depending on moneyness and time-to-maturity.
Institute of Scientific and Technical Information of China (English)
LIU Li-Guo; TIAN Cheng-Lin; CHEN Ping-Xing; YUAN Nai-Chang
2009-01-01
We derive an analytical lower bound on the concurrence for bipartite quantum systems with an improved computable cross norm or realignment criterion and an improved positive partial transpose criterion respectively.Furthermore we demonstrate that our bound is better than that obtained from the local uncertainty relations criterion with optimal local orthogonal observables which is known as one of the best estimations of concurrence.
Nanogram-scale preparation and NMR analysis for mass-limited small volatile compounds.
Directory of Open Access Journals (Sweden)
Satoshi Nojima
Full Text Available Semiochemicals are often produced in infinitesimally small quantities, so their isolation requires large amounts of starting material, not only requiring significant effort in sample preparation, but also resulting in a complex mixture of compounds from which the bioactive compound needs to be purified and identified. Often, compounds cannot be unambiguously identified by their mass spectra alone, and NMR analysis is required for absolute chemical identification, further exacerbating the situation because NMR is relatively insensitive and requires large amounts of pure analyte, generally more than several micrograms. We developed an integrated approach for purification and NMR analysis of <1 µg of material. Collections from high performance preparative gas-chromatography are directly eluted with minimal NMR solvent into capillary NMR tubes. With this technique, (1H-NMR spectra were obtained on 50 ng of geranyl acetate, which served as a model compound, and reasonable H-H COSY NMR spectra were obtained from 250 ng of geranyl acetate. This simple off-line integration of preparative GC and NMR will facilitate the purification and chemical identification of novel volatile compounds, such as insect pheromones and other semiochemicals, which occur in minute (sub-nanogram, and often limited, quantities.
LIMITS OF SWOT ANALYSIS AND THEIR IMPACT ON DECISIONS IN EARLY WARNING SYSTEMS
Directory of Open Access Journals (Sweden)
Florin POPESCU
2015-04-01
Full Text Available SWOT (strengths, weaknesses, opportunities, threats analysis is useful in the decision-making process – crucial to any organization manager and/or strategist. This study aims to add value to the existing literature on SWOT, indicating its use and limitations, showing the need to link SWOT to other strategic tools and methodologies. As the current environment is turbulent and unpredictable, and economic cycles no longer comply with traditional rules, the precaution has become extremely important. That’s why SWOT should be supplemented with newer dynamic analysis capabilities and strategy tools, as early warning and opportunities system (EWOS, which can provide crucial inputs for scenario building, strategic thinking and decisions. EWOS is a novel approach based on three concepts that contribute to the ability of organization/project managers to develop outstanding capacity to "understand" and "benefit" in identifying opportunities and threats: (i business and competitive intelligence; (ii early warning thinking; (iii strategic thinking in decision making process. EWOS is of practical use for strategists and decision makers.
Maskery, Brian; Coleman, Margaret S.; Weinberg, Michelle; Zhou, Weigong; Rotz, Lisa; Klosovsky, Alexander; Cantey, Paul T.; Fox, LeAnne M.; Cetron, Martin S.; Stauffer, William M.
2016-01-01
Background Many U.S.-bound refugees travel from countries where intestinal parasites (hookworm, Trichuris trichuria, Ascaris lumbricoides, and Strongyloides stercoralis) are endemic. These infections are rare in the United States and may be underdiagnosed or misdiagnosed, leading to potentially serious consequences. This evaluation examined the costs and benefits of combinations of overseas presumptive treatment of parasitic diseases vs. domestic screening/treating vs. no program. Methods An economic decision tree model terminating in Markov processes was developed to estimate the cost and health impacts of four interventions on an annual cohort of 27,700 U.S.-bound Asian refugees: 1) “No Program,” 2) U.S. “Domestic Screening and Treatment,” 3) “Overseas Albendazole and Ivermectin” presumptive treatment, and 4) “Overseas Albendazole and Domestic Screening for Strongyloides”. Markov transition state models were used to estimate long-term effects of parasitic infections. Health outcome measures (four parasites) included outpatient cases, hospitalizations, deaths, life years, and quality-adjusted life years (QALYs). Results The “No Program” option is the least expensive ($165,923 per cohort) and least effective option (145 outpatient cases, 4.0 hospitalizations, and 0.67 deaths discounted over a 60-year period for a one-year cohort). The “Overseas Albendazole and Ivermectin” option ($418,824) is less expensive than “Domestic Screening and Treatment” ($3,832,572) or “Overseas Albendazole and Domestic Screening for Strongyloides” ($2,182,483). According to the model outcomes, the most effective treatment option is “Overseas Albendazole and Ivermectin,” which reduces outpatient cases, deaths and hospitalization by around 80% at an estimated net cost of $458,718 per death averted, or $2,219/$24,036 per QALY/life year gained relative to “No Program”. Discussion Overseas presumptive treatment for U.S.-bound refugees is a cost
Scattering theory methods for bound state problems
International Nuclear Information System (INIS)
For the analysis of the properties of a bound state system one may use in place of the Schroedinger equation the Lippmann-Schwinger (LS) equation for the wave function or the LS equation for the reactance operator. Use of the LS equation for the reactance operator constrains the solution to have correct asymptotic behaviour, so this approach would appear to be desirable when the bound state wave function is to be used to calculate particle transfer form factors. The Schroedinger equation based N-level analysis of the s-wave bound states of a square well is compared to the ones based on the LS equation. It is found that the LS equation methods work better than the Schroedinger equation method. The method that uses the LS equation for the wave function gives the best results for the wave functions while the method that uses the LS equation for the reactance operator gives the best results for the binding energies. The accuracy of the reactance operator based method is remarkably insensitive to changes in the oscillator constant used for the harmonic oscillator function basis set. It is also remarkably insensitive to the number of nodes in the bound state wave function. (Auth.)
Optimal Two Parameter Bounds for the Seiffert Mean
Directory of Open Access Journals (Sweden)
Hui Sun
2013-01-01
Full Text Available We obtain sharp bounds for the Seiffert mean in terms of a two parameter family of means. Our results generalize and extend the recent bounds presented in the Journal of Inequalities and Applications (2012 and Abstract and Applied Analysis (2012.
Directory of Open Access Journals (Sweden)
Peeyush Sahay
2009-10-01
Full Text Available Breath analysis, a promising new field of medicine and medical instrumentation, potentially offers noninvasive, real-time, and point-of-care (POC disease diagnostics and metabolic status monitoring. Numerous breath biomarkers have been detected and quantified so far by using the GC-MS technique. Recent advances in laser spectroscopic techniques and laser sources have driven breath analysis to new heights, moving from laboratory research to commercial reality. Laser spectroscopic detection techniques not only have high-sensitivity and high-selectivity, as equivalently offered by the MS-based techniques, but also have the advantageous features of near real-time response, low instrument costs, and POC function. Of the approximately 35 established breath biomarkers, such as acetone, ammonia, carbon dioxide, ethane, methane, and nitric oxide, 14 species in exhaled human breath have been analyzed by high-sensitivity laser spectroscopic techniques, namely, tunable diode laser absorption spectroscopy (TDLAS, cavity ringdown spectroscopy (CRDS, integrated cavity output spectroscopy (ICOS, cavity enhanced absorption spectroscopy (CEAS, cavity leak-out spectroscopy (CALOS, photoacoustic spectroscopy (PAS, quartz-enhanced photoacoustic spectroscopy (QEPAS, and optical frequency comb cavity-enhanced absorption spectroscopy (OFC-CEAS. Spectral fingerprints of the measured biomarkers span from the UV to the mid-IR spectral regions and the detection limits achieved by the laser techniques range from parts per million to parts per billion levels. Sensors using the laser spectroscopic techniques for a few breath biomarkers, e.g., carbon dioxide, nitric oxide, etc. are commercially available. This review presents an update on the latest developments in laser-based breath analysis.
Czech, Christopher
The field of meta-materials engineering has largely expanded mechanical design possibilities over the last two decades; some notable design advances include the systematic engineering of negative Poisson's ratio materials and functionally graded materials, materials designed for optimal electronic and thermo-mechanical performances, and the design of materials under uncertainty. With these innovations, the systematic engineering of materials for design-specific uses is becoming more common in industrial and military uses. The motivation for this body of research is the design of the shear beam for a non-pneumatic wheel. Previously, a design optimization of a finite element model of the non-pneumatic wheel was completed, where a linear elastic material was simulated in the shear beam to reduce hysteretic energy losses. As part of the optimization, a set of optimal orthotropic material properties and other geometric properties were identified for the shear beam. Given that no such natural linear elastic material exists, a meta-material can be engineered that meets these properties using the aforementioned tools. However, manufacturing constraints prevent the use of standard homogenization analysis and optimization tools in the engineering of the shear beam due to limitations in the accuracy of the homogenization process for thin materials. In this research, the more general volume averaging analysis is shown to be an accurate tool for meta-material analysis for engineering thin-layered materials. Given an accurate analysis method, several optimization formulations are proposed, and optimality conditions are derived to determine the most mathematically feasible and numerically reliable formulation for topology optimization of a material design problem using a continuous material interpolation over the design domain. This formulation is implemented to engineer meta-materials for problems using the volume averaging analysis, which includes the use of variable linking
Institute of Scientific and Technical Information of China (English)
刘怡文; 李伟琴
2002-01-01
Strand Spaces serve as a model of security protocol analysis. In this paper, the main characteristics of Strand Spaces are briefly introduced, and its advantages and disadvantages are presented . An algorithm of building an ideal model of a protocol is proposed, which is used to bound both the abilities of the penetrator and the number of concurrent protocol runs. Combining Model Checking and Strand Spaces, a method is proposed to use both the automatic reasoning mechanism of the Model Checking and the bounds on security protocol analysis to achieve effective analysis of security protocols, avoiding state explosion problems.%Strand Spaces是一种用于分析安全协议的机器证明方法.简要介绍了Strand Spaces的基本特点,分析了其优劣,提出了构造协议的理想子环的算法,并以此来约束协议入侵者的能力和协议并行运行的次数.将模型检查与Strand Spaces结合在一起,提出了一种综合分析方法来验证协议的安全特性,该方法可充分发挥模型检查与Strand Spaces二者的优势.
Energy Technology Data Exchange (ETDEWEB)
Wittenmyer, Robert A.; Marshall, Jonathan P., E-mail: rob@phys.unsw.edu.au [School of Physics, UNSW Australia, Sydney 2052 (Australia)
2015-02-01
Solid material in protoplanetary disks will suffer one of two fates after the epoch of planet formation; either being bound up into planetary bodies, or remaining in smaller planetesimals to be ground into dust. These end states are identified through detection of sub-stellar companions by periodic radial velocity (or transit) variations of the star, and excess emission at mid- and far-infrared wavelengths, respectively. Since the material that goes into producing the observable outcomes of planet formation is the same, we might expect these components to be related both to each other and their host star. Heretofore, our knowledge of planetary systems around other stars has been strongly limited by instrumental sensitivity. In this work, we combine observations at far-infrared wavelengths by IRAS, Spitzer, and Herschel with limits on planetary companions derived from non-detections in the 16 year Anglo-Australian Planet Search to clarify the architectures of these (potential) planetary systems and search for evidence of correlations between their constituent parts. We find no convincing evidence of such correlations, possibly owing to the dynamical history of the disk systems, or the greater distance of the planet-search targets. Our results place robust limits on the presence of Jupiter analogs which, in concert with the debris disk observations, provides insights on the small-body dynamics of these nearby systems.
Soil texture and climatc conditions for biocrust growth limitation: a meta analysis
Fischer, Thomas; Subbotina, Mariia
2015-04-01
clay content and with study site as a random effect. (III) Threshold values of texture and climatc effects were identified using a regression tree. Three mean annual temperature classes for texture dependent BSC growth limitation were identified: (1) 19 °C at soils with 17% silt and clay. Because biocrust development is limited under certain climatic and soil texture conditions, it is suggested to consider soil texture for biocrust rehabilitation purposes and in biogeochemical modeling of cryptogamic ground covers. References Belnap, J. & Eldridge, D. 2001. Disturbance and Recovery of Biological Soil Crusts. In: Belnap, J. & Lange, O. (eds.) Biological Soil Crusts: Structure, Function, and Management, Springer, Berlin. Belnap, J. 2001. Biological Soil Crusts and Wind Erosion. In: Belnap, J. & Lange, O. (eds.) Fischer, T., Subbotina, M. 2014. Climatic and soil texture threshold values for cryptogamic cover development: a meta analysis. Biologia 69/11:1520-1530,
Bounds on Heat Transport in Rapidly Rotating Rayleigh-B\\'{e}nard Convection
Grooms, Ian
2014-01-01
The heat transport in rotating Rayleigh-B\\'enard convection is considered in the limit of rapid rotation (small Ekman number $E$) and strong thermal forcing (large Rayleigh number $Ra$). The analysis proceeds from a set of asymptotically reduced equations appropriate for rotationally constrained dynamics; the conjectured range of validity for these equations is $Ra \\lesssim E^{-8/5}$. A rigorous bound on heat transport of $Nu \\le 20.56Ra^3E^4$ is derived in the limit of infinite Prandtl number using the background method. We demonstrate that the exponent in this bound cannot be improved on using a piece-wise monotonic background temperature profile like the one used here. This is true for finite Prandtl numbers as well, i.e. $Nu \\lesssim Ra^3$ is the best upper bound for this particular setup of the background method. The feature that obstructs the availability of a better bound in this case is the appearance of small-scale thermal plumes emanating from (or entering) the thermal boundary layer.
Asymptotic properties of bound states in coupled quantum wave guides
Energy Technology Data Exchange (ETDEWEB)
Maglione, Enrico [Dipartimento di Fisica G Galilei, Via F Marzolo 8, Padova (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova (Italy); Centro de Fisica das Interaccoes Fundamentais (CFIF), Avenida Rovisco Pais, Lisbon (Portugal); Departamento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Ferreira, LIdia S [Centro de Fisica das Interaccoes Fundamentais (CFIF), Avenida Rovisco Pais, Lisbon (Portugal); Departamento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Cattapan, Giorgio [Dipartimento di Fisica G Galilei, Via F Marzolo 8, Padova (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova (Italy)
2006-02-03
We investigate the motion of bound-state poles in two quantum wave guides laterally coupled through a window. The imaginary momentum ik at the bound-state poles is studied as a function of the size a of the window. Both bound and virtual states appear as a spans the whole range from 0 up to +{infinity}. We are able to find simple scaling laws relating the critical value of the window size at which the nth bound state appears to the number n of bound states, in the limit of large n. A similar relation is also provided for the slope and the second derivative of the pole trajectories in the (k, a) plane. These relations are characterized by an extremely high numerical accuracy. We also evaluate the exact value of the first two derivatives for a = 0.
Upper Bound Solution for the Face Stability of Shield Tunnel below the Water Table
Directory of Open Access Journals (Sweden)
Xilin Lu
2014-01-01
Full Text Available By FE simulation with Mohr-Coulomb perfect elastoplasticity model, the relationship between the support pressure and displacement of the shield tunnel face was obtained. According to the plastic strain distribution at collapse state, an appropriate failure mechanism was proposed for upper bound limit analysis, and the formula to calculate the limit support pressure was deduced. The limit support pressure was rearranged to be the summation of soil cohesion c, surcharge load q, and soil gravity γ multiplied by their corresponding coefficients Nc, Nq, and Nγ, and parametric studies were carried out on these coefficients. In order to consider the influence of seepage on the face stability, the pore water pressure distribution and the seepage force on the tunnel face were obtained by FE simulation. After adding the power of seepage force into the equation of the upper bound limit analysis, the total limit support pressure for stabilizing the tunnel face under seepage condition was obtained. The total limit support pressure was shown to increase almost linearly with the water table.
Combining Alphas via Bounded Regression
Directory of Open Access Journals (Sweden)
Zura Kakushadze
2015-11-01
Full Text Available We give an explicit algorithm and source code for combining alpha streams via bounded regression. In practical applications, typically, there is insufficient history to compute a sample covariance matrix (SCM for a large number of alphas. To compute alpha allocation weights, one then resorts to (weighted regression over SCM principal components. Regression often produces alpha weights with insufficient diversification and/or skewed distribution against, e.g., turnover. This can be rectified by imposing bounds on alpha weights within the regression procedure. Bounded regression can also be applied to stock and other asset portfolio construction. We discuss illustrative examples.
Institute of Scientific and Technical Information of China (English)
Zhi-Hong Tao; Cong-Hua Zhou; Zhong Chen; Li-Fu Wang
2007-01-01
Bounded Model Checking has been recently introduced as an efficient verification method for reactive systems.This technique reduces model checking of linear temporal logic to propositional satisfiability.In this paper we first present how quantified Boolean decision procedures can replace BDDs.We introduce a bounded model checking procedure for temporal logic CTL* which reduces model checking to the satisfiability of quantified Boolean formulas.Our new technique avoids the space blow up of BDDs, and extends the concept of bounded model checking.
The Second Painlev\\'e Equation in the Large-Parameter Limit I: Local Asymptotic Analysis
Joshi, Nalini
1997-01-01
In this paper, we find all possible asymptotic behaviours of the solutions of the second Painlev\\'e equation $y''=2y^3+xy +\\alpha$ as the parameter $\\alpha\\to\\infty$ in the local region $x\\ll\\alpha^{2/3}$. We prove that these are asymptotic behaviours by finding explicit error bounds. Moreover, we show that they are connected and complete in the sense that they correspond to all possible values of initial data given at a point in the local region.
Complexity Analysis of a Cournot-Bertrand Duopoly Game Model with Limited Information
Directory of Open Access Journals (Sweden)
Hongwu Wang
2013-01-01
principles of decision-making are bounded rational. One firm chooses output and the other chooses price as decision variable, with the assumption that there is a certain degree of differentiation between the products offered by firms to avoid the whole market being occupied by the one that applies a lower price. The existence of Nash equilibrium point and its local stability of the game are investigated. The complex dynamics, such as bifurcation scenarios and route to chaos, are displayed using parameter basin plots by numerical experiment. The influences of the parameters on the system performance are discussed from the perspective of economics.
Limit State Analysis of Reinforced Concrete Plates subjected to in-plane forces
DEFF Research Database (Denmark)
Poulsen, Peter Noe; Damkilde, Lars
2000-01-01
A finite element formulation of rigid-plastic plates subjected to in-plane forces is developed using stress-based elements and linear programming. Three elements are established, namely a triangular plate element, a bar element and a beam element. The problem is formulated as a lower bound solution......, and the dual variables are interpreted as displacements. Both load and material optimization are formulated. The method is applied to concrete plate structures modelling both the distributed and the concentrated reinforcement. An efficient computational scheme is used, thereby reducing the size of the problem....... Finally, numerical examples are presented to show the capabilities of the method....
Directory of Open Access Journals (Sweden)
van Duijn Cornelia
2010-10-01
Full Text Available Abstract Background Presence of interaction between a genotype and certain factor in determination of a trait's value, it is expected that the trait's variance is increased in the group of subjects having this genotype. Thus, test of heterogeneity of variances can be used as a test to screen for potentially interacting single-nucleotide polymorphisms (SNPs. In this work, we evaluated statistical properties of variance heterogeneity analysis in respect to the detection of potentially interacting SNPs in a case when an interaction variable is unknown. Results Through simulations, we investigated type I error for Bartlett's test, Bartlett's test with prior rank transformation of a trait to normality, and Levene's test for different genetic models. Additionally, we derived an analytical expression for power estimation. We showed that Bartlett's test has acceptable type I error in the case of trait following a normal distribution, whereas Levene's test kept nominal Type I error under all scenarios investigated. For the power of variance homogeneity test, we showed (as opposed to the power of direct test which uses information about known interacting factor that, given the same interaction effect, the power can vary widely depending on the non-estimable direct effect of the unobserved interacting variable. Thus, for a given interaction effect, only very wide limits of power of the variance homogeneity test can be estimated. Also we applied Levene's approach to test genome-wide homogeneity of variances of the C-reactive protein in the Rotterdam Study population (n = 5959. In this analysis, we replicate previous results of Pare and colleagues (2010 for the SNP rs12753193 (n = 21, 799. Conclusions Screening for differences in variances among genotypes of a SNP is a promising approach as a number of biologically interesting models may lead to the heterogeneity of variances. However, it should be kept in mind that the absence of variance heterogeneity for
Lower Bounds for Quantum Oblivious Transfer
Chailloux, André; Sikora, Jamie
2010-01-01
Oblivious transfer is a fundamental primitive in cryptography. While perfect information theoretic security is impossible, quantum oblivious transfer protocols can limit the dishonest players' cheating. Finding the optimal security parameters in such protocols is an important open question. In this paper we show that every 1-out-of-2 oblivious transfer protocol allows a dishonest party to cheat with probability bounded below by a constant strictly larger than 1/2. Alice's cheating is defined as her probability of guessing Bob's index, and Bob's cheating is defined as his probability of guessing both input bits of Alice. In our proof, we relate these cheating probabilities to the cheating probabilities of a coin flipping protocol and conclude by using Kitaev's coin flipping lower bound. Then, we present an oblivious transfer protocol with two messages and cheating probabilities at most 3/4. Last, we extend Kitaev's semidefinite programming formulation to more general primitives, where the security is against a...
Bounds on bacterial cell growth rates
Landy, Jonathan
2013-01-01
Recent experiments have shown that rod-like bacteria in nutrient-rich media grow in length at an exponential rate. Here, I point out that it is the elongated shape of these bacteria that allows for this behavior. Further, I show that when a bacterium's growth is limited by some nutrient -- taken in by the cell through a diffusion-to-capture process -- its growth is suppressed: In three-dimensional geometries, the length $L$ is bounded by $\\log L \\lesssim t^{1/2}$, while in two dimensions the length is bounded by a power-law form. Fits of experimental growth curves to these predicted, sub-exponential forms could allow for direct measures of quantities relating to cellular metabolic rates.
Probabilistically Bounded Staleness for Practical Partial Quorums
Bailis, Peter; Franklin, Michael J; Hellerstein, Joseph M; Stoica, Ion
2012-01-01
Data store replication results in a fundamental trade-off between operation latency and data consistency. In this paper, we examine this trade-off in the context of quorum-replicated data stores. Under partial, or non-strict quorum replication, a data store waits for responses from a subset of replicas before answering a query, without guaranteeing that read and write replica sets intersect. As deployed in practice, these configurations provide only basic eventual consistency guarantees, with no limit to the recency of data returned. However, anecdotally, partial quorums are often "good enough" for practitioners given their latency benefits. In this work, we explain why partial quorums are regularly acceptable in practice, analyzing both the staleness of data they return and the latency benefits they offer. We introduce Probabilistically Bounded Staleness (PBS) consistency, which provides expected bounds on staleness with respect to both versions and wall clock time. We derive a closed-form solution for versi...
Bound States for Magic State Distillation
Campbell, Earl T
2009-01-01
Magic state distillation is an important primitive in fault-tolerant quantum computation. The magic states are pure non-stabilizer states which can be distilled from certain mixed non-stabilizer states via Clifford group operations alone. Due to the Gottesman-Knill theorem, convex mixtures of Pauli eigenstates are not expected to be magic state distillable, but it has been an open question whether all mixed states outside this octahedral set may be distilled. In this Letter we show that, when resources are finitely limited, non-distillable states exist outside the stabilizer octahedron. In analogy with the bound entangled states, which arise in entanglement theory, we call such states bound states for magic state distillation.
THE CRITICAL ANALYSIS OF LIMITED SOUTH ASIAN CORPORATE GOVERNANCE STANDARDS AFTER FINANCIAL CRISIS
Directory of Open Access Journals (Sweden)
Dinh Tran Ngoc Huy
2015-12-01
Full Text Available After the recent global crisis, corporate scandals and bankruptcy in US and Europe, there is some certain evidence on weak corporate governance, risk management and audit system. The 2009 India Code of Corporate Governance also revealed that during the crisis time, there are certain weaknesses although corporate structure is fairly durable. Hence, this paper chooses a different analytical approach and among its aims is to give some systematic opinions. First, it classifies limited South Asian representative corporate governance (CG standards into two (2 groups: India and Malaysia latest CG principles covered in group 1 and, group 2, including corporate governance principle from Thailand and Indonesia, so-called relative good CG group, while it uses ACCA and OECD and ICGN principles as reference. Second, it, through analysis, identifies differences and advantages between above set of standards which are and have been used as reference principles for many relevant organizations. Third, it establishes a selected comparative set of standards for South Asian representative corporate governance system in accordance to international standards. Last but not least, this paper covers some ideas and policy suggestions.
Quiroz, Jorge; Tsao, Yung-Shyeng
2016-07-01
Assurance of monoclonality of recombinant cell lines is a critical issue to gain regulatory approval in biological license application (BLA). Some of the requirements of regulatory agencies are the use of proper documentations and appropriate statistical analysis to demonstrate monoclonality. In some cases, one round may be sufficient to demonstrate monoclonality. In this article, we propose the use of confidence intervals for assessing monoclonality for limiting dilution cloning in the generation of recombinant manufacturing cell lines based on a single round. The use of confidence intervals instead of point estimates allow practitioners to account for the uncertainty present in the data when assessing whether an estimated level of monoclonality is consistent with regulatory requirements. In other cases, one round may not be sufficient and two consecutive rounds are required to assess monoclonality. When two consecutive subclonings are required, we improved the present methodology by reducing the infinite series proposed by Coller and Coller (Hybridoma 1983;2:91-96) to a simpler series. The proposed simpler series provides more accurate and reliable results. It also reduces the level of computation and can be easily implemented in any spreadsheet program like Microsoft Excel. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1061-1068, 2016.
REE bound DNA in natural plant
Institute of Scientific and Technical Information of China (English)
王玉琦; 江平; 郭繁清; 张智勇; 孙景信; 许雷; 曹国印
1999-01-01
The binding of rare earth elements (REEs) with nucleic acids in the leaves of fern Dicranopteris dichotoma (DD) has been studied by molecular activation analysis (MAA). The REEs bound DNA (REE-DNA) was obtained from the leaves of DD. The CTAB-based procedure was modified for extraction of total DNA. The purity of DNA was examined by UV spectroscopy. The DNA obtained was separated and determined by agarose gel electrophoresis further. Meanwhile, the contents of eight rare earth elements (La, Ce, Nd, Sm, Eu,Tb, Yb and Lu) in REE-DNA were detected by instrumental neutron activation analysis (INAA). The results showed that REE-DNA with higher purity could be extracted from plant using this method. It was also found that REEs were bound firmly with DNA in the leaves of DD. The molecular weight (MW) of REE-DNA band was about 22 kb in agarose gel electrophoresis.
Kaur, Mandeep; Sharma, Manoj K; Gupta, Raj K
2015-01-01
The dynamics of the reactions forming compound nuclei using loosely bound projectiles is analysed within the framework of dynamical cluster decay model (DCM) of Gupta and Collaborators. We have analysed different reactions with $^{7}Li$, $^{9}Be$ and $^{7}Be$ as neutron rich and neutron deficient projectiles, respectively, on different targets at the three $E_{lab}$ values, forming compound nuclei within the mass region A$\\sim 30-200$. The contributions of light particles LPs ($A\\le4$) cross sections $\\sigma_{LP}$, energetically favoured intermediate mass fragments IMFs ($5 \\le A_2 \\le 20$) cross sections $\\sigma_{IMF}$ as well as fusion-fission $\\it{ff}$ cross sections $\\sigma_{ff}$ constitute the $\\sigma_{fus}$ (=$\\sigma_{LP}$+$\\sigma_{IMF}$+$\\sigma_{ff}$) for these reactions. The contribution of the emitted LPs, IMFs and ff fragments is added for all the angular momentum upto the $\\ell_{max}$ value, for the resepctive reactions. Interestingly, we find that the $\\Delta R^{emp}$, the only parameter of model ...
Curvature bounds for configuration spaces
Erbar, Matthias; Huesmann, Martin
2014-01-01
We show that the configuration space over a manifold M inherits many curvature properties of the manifold. For instance, we show that a lower Ricci curvature bound on M implies for the configuration space a lower Ricci curvature bound in the sense of Lott-Sturm-Villani, the Bochner inequality, gradient estimates and Wasserstein contraction. Moreover, we show that the heat flow on the configuration space, or the infinite independent particle process, can be identified as the gradient flow of t...
Finite Domain Bounds Consistency Revisited
Choi, Chiu Wo; Harvey, Warwick; Lee, Jimmy Ho-Man; Stuckey, Peter J.
2004-01-01
A widely adopted approach to solving constraint satisfaction problems combines systematic tree search with constraint propagation for pruning the search space. Constraint propagation is performed by propagators implementing a certain notion of consistency. Bounds consistency is the method of choice for building propagators for arithmetic constraints and several global constraints in the finite integer domain. However, there has been some confusion in the definition of bounds consistency. In t...
Entropy bounds for uncollapsed matter
Energy Technology Data Exchange (ETDEWEB)
Abreu, Gabriel; Visser, Matt, E-mail: Gabriel.Abreu@msor.vuw.ac.nz, E-mail: Matt.Visser@msor.vuw.ac.nz [School of Mathematics, Statistics and Operation Research Victoria University of Wellington Wellington (New Zealand)
2011-09-22
In any static spacetime the quasilocal Tolman mass contained within a volume can be reduced to a Gauss-like surface integral involving the flux of a suitably defined generalized surface gravity. By introducing some basic thermodynamics, and invoking the Unruh effect, one can then develop elementary bounds on the quasilocal entropy that are very similar in spirit to the holographic bound, and closely related to entanglement entropy.
The Effect of Drive Signal Limiting on High Cycle Fatigue Life Analysis
Kihm, Frederic; Rizzi, Stephen A.
2014-01-01
It is common practice to assume a Gaussian distribution of both the input acceleration and the response when modeling random vibration tests. In the laboratory, however, shaker controllers often limit the drive signal to prevent high amplitude peaks. The high amplitudes may either be truncated at a given level (socalled brick wall limiting or abrupt clipping), or compressed (soft limiting), resulting in drive signals which are no longer Gaussian. The paper first introduces several methods for limiting a drive signal, including brick wall limiting and compression. The limited signal is then passed through a linear time-invariant system representing a device under test. High cycle fatigue life predictions are subsequently made using spectral fatigue and rainflow cycle counting schemes. The life predictions are compared with those obtained from unclipped input signals. Some guidelines are provided to help the test engineer decide how clipping should be applied under different test scenarios.
有限理性对劳动力流动决策的影响分析%An analysis of the influence of bounded rationality on labor flow decision-making
Institute of Scientific and Technical Information of China (English)
袁乐平; 王立软; 李萍
2012-01-01
经典劳动力流动理论以完全理性为假设前提，难以准确分析当前我国存在的“盲流”“回流”等劳动力流动“异象”问题。通过对劳动力流动现状与传统理论之间的冲突进行分析，得出造成劳动力流动异象的原因在于劳动者的有限理性。劳动者的有限理性造成预期成本和收益与实际不符，进而影响劳动力的流动决策，当预期净收益现值与实际净收益现值异号时，劳动力流动“异象”便会发生。% The classical labor flow theory is based on the assumption of perfect rationality, which cannot acutely analyze the heteromorphism problem in present Chinese labor flow such as “unemployed migrant people” and labor backflow. The theory deviates from the reality. Through the analysis of conflict between current situation of labor flow and traditional theory, we conclude that bounded rationality leads to heteromorphism problem. So, we analyze the process of generation of labor flow decision-making from the perspective of bounded rationality. The bounded rationality cause the expected costs and benefits do not match with the actual, which would affect labors’ decision-making for flow. Labor flow heteromorphism occurs when there is an opposite sign between the present value of expected net income and the present value of actual net income.
Directory of Open Access Journals (Sweden)
Cem KADILAR
2005-01-01
Full Text Available This study includes an econometric analysis of the export demand behaviour by using Turkey's annual data that cover 32 years periods from 1970 to 2002. In the study, the 'bounds test' method of Pesaran et al (2001 was used to investigate the long run relationship between export demand, and its determinants, namely income and relative prices. As a result of this empirical analysis, it was demonstrated that export volume, income and relative prices were cointegrated. The estimated long term elasticities of export demand with respect to income and relative prices are 0.21 and -1.684, respectively. The sum of the elasticities of import and export demand exceeds one (-1.01 i.e., Marshall-Lerner condition holds. These results show that monetary, fiscal and exchange rate policies may be used as substitutive policies to correct unfavourable trade balance.
Composition and Structural Features of Calcium—Bound and Iron—and Aluminium—Bound Humus in Soils
Institute of Scientific and Technical Information of China (English)
S．U．CHEEMA; XUJIAN－MIN; 等
1994-01-01
Calcium-bound and iron-and aluminium-bound humus extracted from different soils collected from north to south of China were characterized by chemical and spectroscopic methods.Meaningful differences in the composition and structure between them were revealed by 13 C NMR,visible spectroscopy and elemental analysis.Results showed that the contents of carbon,hydrogen and nitrogen were higher in iron-and aluminium-bound humus than in calcium-bound humus while oxygen content in calcium-bound humus was shown to be higher .The calcium-bound humus had higher C/N and O/C ratios than iron-and aluminiumbound humus.The calcium-bound humic acid(HA1) showed higher E4/E6 ratios than iron-and aluminumboud,humic acid(HA2)while iron-and aluminum-bound fulvic acid(FA2) showed higher E4/E6 ratios than calcium-bound fulvic acid(FA1).An inverse relationship between E4/E6 ratios and aromaticity as determined by 13C NMR spectra was observerd for HA and FA from black soil.The 13C NMR spectroscopy revealed that HA2 was more aromatic than HA1.On the other ,FA1 exhibited a higher aromaticity than FA2.
Description of Wiener bounds of multicomponent composites by barycentric coordinates
Peiponen, Kai-Erik; Gornov, Evgeny
2006-07-01
Wiener bounds for effective complex permittivity of multicomponent composites are treated by use of barycentric coordinates, a convex hull, and conformal mapping in a complex plane. Depending on the complexity of the multiphase system, the bounds provide singly or multiply connected regions that can be used in estimating the limits of the effective permittivity of the composite. The present modeling is important, e.g., in estimating spectral properties of nanocomposites in engineering and nanomedicine and in terahertz-based security imaging.
Directory of Open Access Journals (Sweden)
Wenjie Bi
2014-01-01
Full Text Available Dynamic portfolio choice is an important problem in finance, but the optimal strategy analysis is difficult when considering multiple stochastic volatility variables such as the stock price, interest rate, and income. Besides, recent research in experimental economics indicates that the agent shows limited attention, considering only the variables with high fluctuations but ignoring those with small ones. By extending the sparse max method, we propose an approach to solve dynamic programming problem with small stochastic volatility and the agent’s bounded rationality. This approach considers the agent’s behavioral factors and avoids effectively the “Curse of Dimensionality” in a dynamic programming problem with more than a few state variables. We then apply it to Merton dynamic portfolio choice model with stochastic volatility and get a tractable solution. Finally, the numerical analysis shows that the bounded rational agent may pay no attention to the varying equity premium and interest rate with small variance.
Wagner, B.J.; Harvey, J.W.
1997-01-01
Tracer experiments are valuable tools for analyzing the transport characteristics of streams and their interactions with shallow groundwater. The focus of this work is the design of tracer studies in high-gradient stream systems subject to advection, dispersion, groundwater inflow, and exchange between the active channel and zones in surface or subsurface water where flow is stagnant or slow moving. We present a methodology for (1) evaluating and comparing alternative stream tracer experiment designs and (2) identifying those combinations of stream transport properties that pose limitations to parameter estimation and therefore a challenge to tracer test design. The methodology uses the concept of global parameter uncertainty analysis, which couples solute transport simulation with parameter uncertainty analysis in a Monte Carlo framework. Two general conclusions resulted from this work. First, the solute injection and sampling strategy has an important effect on the reliability of transport parameter estimates. We found that constant injection with sampling through concentration rise, plateau, and fall provided considerably more reliable parameter estimates than a pulse injection across the spectrum of transport scenarios likely encountered in high-gradient streams. Second, for a given tracer test design, the uncertainties in mass transfer and storage-zone parameter estimates are strongly dependent on the experimental Damkohler number, DaI, which is a dimensionless combination of the rates of exchange between the stream and storage zones, the stream-water velocity, and the stream reach length of the experiment. Parameter uncertainties are lowest at DaI values on the order of 1.0. When DaI values are much less than 1.0 (owing to high velocity, long exchange timescale, and/or short reach length), parameter uncertainties are high because only a small amount of tracer interacts with storage zones in the reach. For the opposite conditions (DaI >> 1.0), solute exchange
Processes regulating progressive nitrogen limitation under elevated carbon dioxide: a meta-analysis
Liang, Junyi; Qi, Xuan; Souza, Lara; Luo, Yiqi
2016-05-01
The nitrogen (N) cycle has the potential to regulate climate change through its influence on carbon (C) sequestration. Although extensive research has explored whether or not progressive N limitation (PNL) occurs under CO2 enrichment, a comprehensive assessment of the processes that regulate PNL is still lacking. Here, we quantitatively synthesized the responses of all major processes and pools in the terrestrial N cycle with meta-analysis of CO2 experimental data available in the literature. The results showed that CO2 enrichment significantly increased N sequestration in the plant and litter pools but not in the soil pool, partially supporting one of the basic assumptions in the PNL hypothesis that elevated CO2 results in more N sequestered in organic pools. However, CO2 enrichment significantly increased the N influx via biological N fixation and the loss via N2O emission, but decreased the N efflux via leaching. In addition, no general diminished CO2 fertilization effect on plant growth was observed over time up to the longest experiment of 13 years. Overall, our analyses suggest that the extra N supply by the increased biological N fixation and decreased leaching may potentially alleviate PNL under elevated CO2 conditions in spite of the increases in plant N sequestration and N2O emission. Moreover, our syntheses indicate that CO2 enrichment increases soil ammonium (NH4+) to nitrate (NO3-) ratio. The changed NH4+/NO3- ratio and subsequent biological processes may result in changes in soil microenvironments, above-belowground community structures and associated interactions, which could potentially affect the terrestrial biogeochemical cycles. In addition, our data synthesis suggests that more long-term studies, especially in regions other than temperate ones, are needed for comprehensive assessments of the PNL hypothesis.
Statistical analysis of iron geochemical data suggests limited late Proterozoic oxygenation
Sperling, Erik A.; Wolock, Charles J.; Morgan, Alex S.; Gill, Benjamin C.; Kunzmann, Marcus; Halverson, Galen P.; MacDonald, Francis A.; Knoll, Andrew H.; Johnston, David T.
2015-07-01
Sedimentary rocks deposited across the Proterozoic-Phanerozoic transition record extreme climate fluctuations, a potential rise in atmospheric oxygen or re-organization of the seafloor redox landscape, and the initial diversification of animals. It is widely assumed that the inferred redox change facilitated the observed trends in biodiversity. Establishing this palaeoenvironmental context, however, requires that changes in marine redox structure be tracked by means of geochemical proxies and translated into estimates of atmospheric oxygen. Iron-based proxies are among the most effective tools for tracking the redox chemistry of ancient oceans. These proxies are inherently local, but have global implications when analysed collectively and statistically. Here we analyse about 4,700 iron-speciation measurements from shales 2,300 to 360 million years old. Our statistical analyses suggest that subsurface water masses in mid-Proterozoic oceans were predominantly anoxic and ferruginous (depleted in dissolved oxygen and iron-bearing), but with a tendency towards euxinia (sulfide-bearing) that is not observed in the Neoproterozoic era. Analyses further indicate that early animals did not experience appreciable benthic sulfide stress. Finally, unlike proxies based on redox-sensitive trace-metal abundances, iron geochemical data do not show a statistically significant change in oxygen content through the Ediacaran and Cambrian periods, sharply constraining the magnitude of the end-Proterozoic oxygen increase. Indeed, this re-analysis of trace-metal data is consistent with oxygenation continuing well into the Palaeozoic era. Therefore, if changing redox conditions facilitated animal diversification, it did so through a limited rise in oxygen past critical functional and ecological thresholds, as is seen in modern oxygen minimum zone benthic animal communities.
Muhammad Abi Sofian Abdul Halim; Hasyaniza Yahya; Syahrul Hezrin Mahmud; Fatimah Zainab
2011-01-01
This study will determine the level of satisfaction among Terengganu private limited companies towards the concept of corporate entrepreneurship, in a context of; corporate venturing, strategic renewal, and internalization. The study was based on a survey carried out from the questionnaire that is administered involving 105 private limited companies which are operated their business in Terengganu. By using the descriptive analysis on the level of satisfaction among the Terengganu private limi...
Upper Bounds on the Neutrino-Nucleon Inelastic Cross Section
Anchordoqui, L A; Katz, S D; Ringwald, A; Tu, H
2004-01-01
Extraterrestrial neutrinos can initiate deeply developing air showers, and those that traverse the atmosphere unscathed may produce cascades in the ice or water. Up to now, no such events have been observed. This can be translated into upper limits on the diffuse neutrino flux. On the other hand, the observation of cosmic rays with primary energies > 10^{10} GeV suggests that there is a guaranteed flux of cosmogenic neutrinos, arising from the decay of charged pions (and their muon daughters) produced in proton interactions with the cosmic microwave background. In this work, armed with these cosmogenic neutrinos and the increased exposure of neutrino telescopes we bring up-to-date model-independent upper bounds on the neutrino-nucleon inelastic cross section. Uncertainties in the cosmogenic neutrino flux are discussed and taken into account in our analysis. The prospects for improving these bounds with the Pierre Auger Observatory are also estimated. The unprecedented statistics to be collected by this experi...
Physical bounds for antenna radiation efficiency
Shahpari, Morteza
2016-01-01
Small volume, reduced conductivity and high frequencies are major imperatives in the design of communications infrastructure. The radiation efficiency $\\eta_r$ impacts on the optimal gain, quality factor, and bandwidth. The current efficiency limit applies to structures confined to a radian sphere $ka$ ($k$ is the wave number, $a$ is the radius). Here we present new absolute limits to $\\eta_r$ for arbitrary antenna shapes based on $k^2S$ where $S$ is the conductor surface area. For an electrical length of $10^{-5}$ our result is four orders of magnitude closer to the analytical solution. The improved bound on $\\eta_r$ is more accurate, more general, and easier to calculate than other limits. It is based on the total surface area of the conductors and provides greatly improved estimations for electrically small radiators at very low frequencies. The work is of great benefit to antenna designers assessing new materials such as conductive polymers.
Preliminary design analysis of the ALT-II limiter for TEXTOR
International Nuclear Information System (INIS)
Installation of a large toroidal belt pump limiter, Advanced Limiter Test II (ALT-II), on the TEXTOR tokamak at Juelich, FRG is anticipated for early 1986. This paper discusses the preliminary mechanical design and materials considerations undertaken as part of the feasibility study phase for ALT-II
On a Generalization of Kingman's Bounds
Liu, Zhen; Nain, Philippe; Towsley, Don
1994-01-01
In this paper we develop a framework for computing upper and lower bounds of an exponential form for a class of single server queueing systems with non-renewal inputs. These bounds generalize Kingman's bounds for queues with renewal inputs.
Andreev bound states. Some quasiclassical reflections
Energy Technology Data Exchange (ETDEWEB)
Lin, Y., E-mail: yiriolin@illinois.edu; Leggett, A. J. [University of Illinois at Urhana-Champaign, Dept. of Physics (United States)
2014-12-15
We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it.
Energy Technology Data Exchange (ETDEWEB)
HU TA
2007-10-31
This document describes the analysis of the waste evaporation process on the flammability behavior. The evaluation calculates the gas generation rate, time to reach 25% and 100% of the lower flammability limit (LFL), and minimum ventilation rates for the 242-A Evaporator facility during the normal evaporation process and when vacuum is lost. This analysis performs flammability calculations on the waste currently within all 28 double-shell tanks (DST) under various evaporation process conditions to provide a wide spectrum of possible flammable gas behavior. The results of this analysis are used to support flammable gas control decisions and support and upgrade to Documented Safety Analysis for the 242-A Evaporator.
Organically bound tritium, OBT: Its true constitution
International Nuclear Information System (INIS)
Full text: Tritium, which is analytically determined to be non-exchangeable bound in tissue solids, is assumed to be bound to carbon. Furthermore, it follows that the biochemical passways by photosynthesis or enzymatic transfer reactions are retarded by the kinetic isotope effect leading to discrimination of tritium in biomolecules. In contrast, the logistic growth analysis of plants discloses a larger intrinsic growth rate of OBT than of OBH, resulting in tritium accumulation in biomolecules. Exchange experiments providing fractionation factors of 1.4 and 2 confirm this accumulation. In summary a larger part of the so called OBT is not carbon bound but consists of tritium positioned in hydrogen bridges of biopolymers which have been occupied during formation of the molecules and which became later inaccessible for exchange (so called buried hydrogens). Furthermore, there are experimental results indicating even rapid exchange during the in vivo state but inhibited in the in vitro state, which is commonly given in bio samples prepared for analysis. (author)
Directory of Open Access Journals (Sweden)
Marina Wolowski
Full Text Available Despite the extensive knowledge of pollen limitation in angiosperms, its assessment within tropical forests is still limited. Especially lacking are large scale comparisons of species within this biome - one that is highly diverse but also becoming increasingly threatened. In fact, many tropical plant species depend upon pollinators for reproduction but evaluation of the impact of this dependence via different levels of pollination specialization has yet to be made at the biome scale. We assessed the occurrence and magnitude of pollen limitation for species in the Brazilian Atlantic forest and tested the association of pollination specialization, breeding system, and life habit with pollination efficiency. We compiled data from studies published between 1985 and 2012. We calculated species' effect size (d from data on fruit set after hand cross-pollination and natural pollination and conducted standard and phylogenetically independent meta-analysis. Overall pollen limitation was moderate, with magnitude of 0.50, and 95% confidence interval [0.37, 0.62] for 126 species. Pollen limitation was observed in 39% of species. Pollination specialization was the factor that best explained the occurrence of pollen limitation. Specifically, phenotypic and ecological specialists (plants with zygomorphic flowers and pollinated by one species of pollinator, respectively had higher pollen limitation than generalist plants (actinomorphic flowers and pollination by two or more species. Functional generalists (plants pollinated by three or more functional groups were not pollen limited. On the other hand, breeding system and life habit were not associated to pollen limitation. Pollen limitation was observed in the Atlantic forest and its magnitude was comparable to that for angiosperms as a whole. The finding that pollination specialization was the strongest predictor of pollen limitation suggests that specialist plants in this biome may be most prone to the
Wolowski, Marina; Ashman, Tia-Lynn; Freitas, Leandro
2014-01-01
Despite the extensive knowledge of pollen limitation in angiosperms, its assessment within tropical forests is still limited. Especially lacking are large scale comparisons of species within this biome - one that is highly diverse but also becoming increasingly threatened. In fact, many tropical plant species depend upon pollinators for reproduction but evaluation of the impact of this dependence via different levels of pollination specialization has yet to be made at the biome scale. We assessed the occurrence and magnitude of pollen limitation for species in the Brazilian Atlantic forest and tested the association of pollination specialization, breeding system, and life habit with pollination efficiency. We compiled data from studies published between 1985 and 2012. We calculated species' effect size (d) from data on fruit set after hand cross-pollination and natural pollination and conducted standard and phylogenetically independent meta-analysis. Overall pollen limitation was moderate, with magnitude of 0.50, and 95% confidence interval [0.37, 0.62] for 126 species. Pollen limitation was observed in 39% of species. Pollination specialization was the factor that best explained the occurrence of pollen limitation. Specifically, phenotypic and ecological specialists (plants with zygomorphic flowers and pollinated by one species of pollinator, respectively) had higher pollen limitation than generalist plants (actinomorphic flowers and pollination by two or more species). Functional generalists (plants pollinated by three or more functional groups) were not pollen limited. On the other hand, breeding system and life habit were not associated to pollen limitation. Pollen limitation was observed in the Atlantic forest and its magnitude was comparable to that for angiosperms as a whole. The finding that pollination specialization was the strongest predictor of pollen limitation suggests that specialist plants in this biome may be most prone to the reproductive failure
{bar K}-NUCLEAR Deeply Bound States?
Gal, Avraham
Following the prediction by Akaishi and Yamazaki of relatively narrow {bar K}-nuclear states, deeply bound by over 100 MeV where the main decay channel {bar K} N -> π Σ is closed, several experimental signals in stopped K- reactions on light nuclei have been interpreted recently as due to such states. In this talk I review (i) the evidence from K--atom data for a deep bar K-nucleus potential, as attractive as V{bar K}(ρ 0) ˜ -(150 - 200) MeV at nuclear matter density, that could support such states; and (ii) the theoretical arguments for a shallow potential, V{bar K}(ρ 0) ˜ -(40 - 60) MeV. I then review a recent work by Mareš, Friedman and Gal in which {bar K}-nuclear bound states are generated dynamically across the periodic table, using a RMF Lagrangian that couples the {bar K} to the scalar and vector meson fields mediating the nuclear interactions. The reduced phase space available for {bar K} absorption from these bound states is taken into account by adding a density- and energy-dependent imaginary term, underlying the corresponding {bar K}-nuclear level widths, with a strength constrained by K--atom fits. Substantial polarization of the core nucleus is found for light nuclei, with central nuclear densities enhanced by almost a factor of two. The binding energies and widths calculated in this dynamical model differ appreciably from those calculated for a static nucleus. These calculations provide a lower limit of Γ {bar K} ˜ 50 ± 10 MeV on the width of nuclear bound states for {bar K} binding energy in the range B{bar K} = 100 - 200 MeV.
Lakshmi, V.; Libertino, A.; Sharma, A.; Claps, P.
2015-12-01
The prospect of climatic change and its impacts have brought spatial statistics of extreme events into sharper focus. The so-called "water bombs" are predicted to become more frequent in the extra-tropical regions, and, actually, they raise serious concerns in some regions of the Mediterranean area. However, quantitative statistical methods to properly account for the probability of occurrence of these super-extreme events are still lacking, due to their rare occurrence and to the limited spatial scale at which these events occur. In order to overcome the lack of data, we propose at first to exploit the information derived from remote sensed datasets. Despite the coarser resolution, these databases are able to provide information continuous in space and time, overcoming the problems related to the discontinuous nature of rainfall measurements. We propose to apply such a kind of approach with the adoption of a Bayesian framework, aimed at combining local measurements with climatic regional information, conditioning the exceedance probability on the large and mesoscale characteristics of the system. The case study refers to an area located in the North-West of Italy, historically affected by extraordinary precipitation events. We use a dataset of daily at-gauge rainfall measurements extracted from the NOAA GHCN-Daily dataset, combined with the ones provided by some local Environmental Agencies. Daily estimations from the TRMM are adopted too. First, we identify the most intense events occurred in the area, combining the information from the different datasets. Analysing the related synoptic conditions with the reanalysis of the ECMWF, we then define the conditional variables and the hierarchical relationships between the events and their type. Different climatic configurations that combined with the local morphology and the seasonal condition of the Mediterranean Sea can triggers very intense precipitation events are identified. The results, compared with those
Empirical Analysis on Transfer and Limitation of Land Contractual Management Right
Institute of Scientific and Technical Information of China (English)
Xiuqing; ZOU
2013-01-01
Existing laws have three limitations on transfer of land contractual management right. The survey of 506 farmer households in Zhejiang,Jiangxi and Guangxi provinces indicates that most farmers have the consistent knowledge of limitation on " transfer being approved by the party giving out the contract in advance" with legislative requirements,but it is not effectively implemented in actual operation. As to limitation on transferee,no matter in cognition of farmers,or in real transfer process,the transferee is not totally limited to farmers engaged in agricultural production and management. For the constraint that the transferor should have stable non-agricultural occupation or stable income source, most farmers agree,but more than half of the farmers have not confirmed the transfer action in practice.
International Nuclear Information System (INIS)
Highlights: ► We suggested the transformer type SFCL with two triggering current levels. ► The short-circuit tests for the suggested SFCL was executed. ► The fault angle as the fault conditions to verify its operation was selected. ► The usefulness of the suggested SFCL was confirmed through the short-circuit test. -- Abstract: In this paper, the transformer type superconducting fault current limiter (SFCL) with two triggering current levels was suggested and its current limiting characteristics were analyzed. The structure of the suggested transformer type SFCL with two triggering current levels largely consists of two parts. One is the transformer with two magnetically coupled coils, which correspond to the primary winding and the secondary one connected with one high-TC superconducting (HTSC) element. The other is third coil, or, another secondary winding with one HTSC element, which is wound on the same iron core together with two coils. This suggested transformer type SFCL can limit the fault current by generating its limiting impedance with two different amplitudes, which are dependent on the initial amplitude of the fault current in case of the fault occurrence. To confirm the usefulness of the proposed SFCL, the current limiting tests of the SFCL according to the fault angle, one of the effective fault conditions to affect the amplitude of the initial fault current, were carried out and its effective limiting operations were discussed
Eta nuclear bound states revisited
Friedman, E; Mareš, J
2013-01-01
The strong energy dependence of the s-wave eta-N scattering amplitude at and below threshold, as evident in coupled-channels K-matrix fits and chiral models that incorporate the S11 N*(1535) resonance, is included self consistently in eta-nuclear bound state calculations. This approach, applied recently in calculations of kaonic atoms and Kbar-nuclear bound states, is found to impose stronger constraints than ever on the onset of eta-nuclear binding, with a minimum value of Re a_{eta N} approximately 0.9 fm required to accommodate an eta-4He bound state. Binding energies and widths of eta-nuclear states are calculated within several underlying eta-N models for nuclei across the periodic table, including eta-25Mg for which some evidence was proposed in a recent COSY experiment.
Improved Range Searching Lower Bounds
DEFF Research Database (Denmark)
Larsen, Kasper Green; Nguyen, Huy L.
2012-01-01
range reporting problem. In approximate simplex range reporting, points that lie within a distance of ε ⋅ Diam(s) from the border of a query simplex s, are free to be included or excluded from the output, where ε ≥ 0 is an input parameter to the range searching problem. We prove our lower bounds......Table of Contents -------------------------------------------------------------------------------- In this paper we present a number of improved lower bounds for range searching in the pointer machine and the group model. In the pointer machine, we prove lower bounds for the approximate simplex...... by constructing a hard input set and query set, and then invoking Chazelle and Rosenberg's [CGTA'96] general theorem on the complexity of navigation in the pointer machine. For the group model, we show that input sets and query sets that are hard for range reporting in the pointer machine (i.e. by Chazelle...
Simulation bounds for system availability
International Nuclear Information System (INIS)
System availability is a dominant factor in the practicality of nuclear power electrical generating plants. A proposed model for obtaining either lower bounds or interval estimates on availability uses observed data on ''n'' failure-to-repair cycles of the system to estimate the parameters in the time-to-failure and time-to-repair models. These estimates are then used in simulating failure/repair cycles of the system. The availability estimate is obtained for each of 5000 samples of ''n'' failure/repair cycles to form a distribution of estimates. Specific percentile points of those simulated distributions are selected as lower simulation bounds or simulation interval bounds for the system availability. The method is illustrated with operational data from two nuclear plants for which an exponential time-to-failure and a lognormal time-to-repair are assumed
Energy bounds in designer gravity
Amsel, Aaron J.; Marolf, Donald
2006-09-01
We consider asymptotically anti-de Sitter gravity coupled to tachyonic scalar fields with mass at or slightly above the Breitenlohner-Freedman bound in d≥4 spacetime dimensions. The boundary conditions in these “designer gravity” theories are defined in terms of an arbitrary function W. We give a general argument that the Hamiltonian generators of asymptotic symmetries for such systems will be finite, and proceed to construct these generators using the covariant phase space method. The direct calculation confirms that the generators are finite and shows that they take the form of the pure gravity result plus additional contributions from the scalar fields. By comparing the generators to the spinor charge, we derive a lower bound on the gravitational energy when W has a global minimum and the Breitenlohner-Freedman bound is not saturated.
Experimental activation of bound entanglement.
Kaneda, Fumihiro; Shimizu, Ryosuke; Ishizaka, Satoshi; Mitsumori, Yasuyoshi; Kosaka, Hideo; Edamatsu, Keiichi
2012-07-27
Entanglement is one of the essential resources in quantum information and communication technology (QICT). The entanglement thus far explored and applied to QICT has been pure and distillable entanglement. Yet, there is another type of entanglement, called "bound entanglement," which is not distillable by local operations and classical communication. We demonstrate the experimental "activation" of the bound entanglement held in the four-qubit Smolin state, unleashing its immanent entanglement in distillable form, with the help of auxiliary two-qubit entanglement and local operations and classical communication. We anticipate that it opens the way to a new class of QICT applications that utilize more general classes of entanglement than ever, including bound entanglement.
Bound-preserving discontinuous Galerkin methods for relativistic hydrodynamics
Qin, Tong; Shu, Chi-Wang; Yang, Yang
2016-06-01
In this paper, we develop a discontinuous Galerkin (DG) method to solve the ideal special relativistic hydrodynamics (RHD) and design a bound-preserving (BP) limiter for this scheme by extending the idea in X. Zhang and C.-W. Shu, (2010) [56]. For RHD, the density and pressure are positive and the velocity is bounded by the speed of light. One difficulty in numerically solving the RHD in its conservative form is that the failure of preserving these physical bounds will result in ill-posedness of the problem and blowup of the code, especially in extreme relativistic cases. The standard way in dealing with this difficulty is to add extra numerical dissipation, while in doing so there is no guarantee of maintaining the high order of accuracy. Our BP limiter has the following features. It can theoretically guarantee to preserve the physical bounds for the numerical solution and maintain its designed high order accuracy. The limiter is local to the cell and hence is very easy to implement. Moreover, it renders L1-stability to the numerical scheme. Numerical experiments are performed to demonstrate the good performance of this bound-preserving DG scheme. Even though we only discuss the BP limiter for DG schemes, it can be applied to high order finite volume schemes, such as weighted essentially non-oscillatory (WENO) finite volume schemes as well.
Refining Castelnuovo-Halphen bounds
Di Gennaro, Vincenzo
2011-01-01
Fix integers $r,d,s,\\pi$ with $r\\geq 4$, $d\\gg s$, $r-1\\leq s \\leq 2r-4$, and $\\pi\\geq 0$. Refining classical results for the genus of a projective curve, we exhibit a sharp upper bound for the arithmetic genus $p_a(C)$ of an integral projective curve $C\\subset {\\mathbb{P}^r}$ of degree $d$, assuming that $C$ is not contained in any surface of degree $ \\pi$. Next we discuss other types of bound for $p_a(C)$, involving conditions on the entire Hilbert polynomial of the integral surfaces on which $C$ may lie.
Variables Bounding Based Retiming Algorithm
Institute of Scientific and Technical Information of China (English)
宫宗伟; 林争辉; 陈后鹏
2002-01-01
Retiming is a technique for optimizing sequential circuits. In this paper, wediscuss this problem and propose an improved retiming algorithm based on variables bounding.Through the computation of the lower and upper bounds on variables, the algorithm can signi-ficantly reduce the number of constraints and speed up the execution of retiming. Furthermore,the elements of matrixes D and W are computed in a demand-driven way, which can reducethe capacity of memory. It is shown through the experimental results on ISCAS89 benchmarksthat our algorithm is very effective for large-scale sequential circuits.
Limit load analysis for local wall-thinning steam generator tubes
International Nuclear Information System (INIS)
Steam generator(SG) tubes form approximately 80% of pressure boundary of the reactor primary coolant[1]. During the past 40 years, a large number of operating PWPs have experienced degradation due to local wall-thinning of SG tubes, which was caused by corrosion or squeezing of tubes at support plate or tubesheet intersections or other reasons. This paper introduced the study of experiment and numerical analyses for plastic limit loads of local wall-thinning SG tubes. The effect of the dimension of local wall-thinning on plastic limit load was analyzed. The main contents in this paper were summarized as follows: 1 Experiment equipment which could test not only bursting pressure but also plastic limit load was built. Two kinds of local wall-thinning shapes were respectively made on SG tubes. One kind of local wall-thinning shape was rectangle-like flaw, which was used to simulate local wall-thinning caused by squeezing of tubes at support plate. The other kind of local wall-thinning shape was arc-like flaw, which was used to simulate local wall-thinning caused by corrosion. Different size local wall-thinning SG tubes of these two kinds of shape were test by using the equipment. 2 Regularization method for local wall-thinning defect was provided based on experimental and finite element method. 3 The effect order of local wall-thinning configuration on plastic limit load was studied. It was found that: Except defect thickness, the longitudinal length and circumferential length of SGT defect can also influence the plastic limit load; When the longitudinal length of SGT defect exceeded 6 mm, the effect of longitudinal length on plastic limit load can be ignored; When the circumferential angle of defect exceed 45 degree, the effect of circumferential angle on plastic limit load can be ignored. (authors)
International Nuclear Information System (INIS)
The document is an economic impact analysis prepared in support of the promulgation of effluent limitations guidelines and standards of performance for drilling and production wastes for the offshore oil and gas industry. The report analyzes the economic impact of alternative regulatory options considered for drilling fluids, drill cuttings, produced water, produced sand, and treatment, workover, and completion fluids
van der Linden, YM; van Kempen, ML; van der Tweel, [No Value; Vanderschueren, RGJRA; Schlosser, JJ; Lammers, JWJ; Struikmans, H
2001-01-01
Recently a meta-analysis showed an improved survival probability of prophylactic cranial irradiation (PCI) in limited disease small-cell lung cancer (LD SCLC) in complete remission after chemotherapy. We evaluated treatment results of PCI+ and PCI- in these patients. Whether PCI (n = 65) or no PCI (
Lying for the Greater Good: Bounded Rationality in a Team
Directory of Open Access Journals (Sweden)
Oktay Sürücü
2014-10-01
Full Text Available This paper is concerned with the interaction between fully and boundedly rational agents in situations where their interests are perfectly aligned. The cognitive limitations of the boundedly rational agent do not allow him to fully understand the market conditions and lead him to take non-optimal decisions in some situations. Using categorization to model bounded rationality, we show that the fully rational agent can nudge, i.e., he can manipulate the information he sends and decrease the expected loss caused by the boundedly rational agent. Assuming different types for the boundedly rational agent, who differ only in the categories used, we show that the fully rational agent may learn the type of the boundedly rational agent along their interaction. Using this additional information, the outcome can be improved and the amount of manipulated information can be decreased. Furthermore, as the length of the interaction increases the probability that the fully rational agent learns the type of the boundedly rational agent grows
Limitation of egg production in Calanus finmarchicus in the field: A stoichiometric analysis
Mayor, Daniel J.; Anderson, Thomas R.; Pond, David W.; Irigoien, Xabier
2009-11-01
The egg production of marine copepods correlates with a range of variables, including the availability of organic carbon (C), nitrogen (N) and the polyunsaturated fatty acids (PUFAs) 20:5( n-3) (EPA) and 22:6( n-3) (DHA). However, an understanding of which substrates limit egg production in the natural environment has yet to be reached. The quantities of C, N, EPA and DHA ingested, derived from parental biomass, and invested in eggs by female Calanus finmarchicus during a 5-day incubation experiment were examined using stoichiometric theory to determine which substrate was limiting. The majority of each substrate was derived from parental biomass, and therefore the existing stoichiometric theory is developed to include this route of supply. The females were essentially devoid of lipid reserves, as evidenced by the lack of the storage fatty acids 20:1( n-9) and 22:1( n-11), and carbon limitation was predicted under most of the scenarios examined. Nitrogen limitation was only apparent when carbon and nitrogen utilisation efficiencies were assumed to be high (0.5) and low (0.4) respectively. PUFAs were assumed to be utilised with high efficiency (0.9), and were never predicted to limit production. This work highlights the need for a more detailed understanding of the maintenance requirements that marine copepods have for C, N, EPA, and DHA and hence the efficiencies with these substrates can be utilised for growth.
极限与无穷小辨析%Limit and Infinitesimal Analysis
Institute of Scientific and Technical Information of China (English)
陈玉发
2015-01-01
Limit and infinitesimal are basic concepts of calculus, and are the theoretical basis of the calculus. The limit is the unity of the dynamic and the static. It can be seen as a function converter like a bridge which connects finite and infinite. With the help of the limit, we can clearly understand the essence of the infinitesimal. On the contrary, the infinitesimal theory is a supplement to the limit theory. A profound understanding of the essence of limit and infinitesimal is essential to the study of Calculus.%极限与无穷小是微积分中的基本概念，是整个微积分学的理论基础。极限是运动与静止的统一；极限可以被看作是函数变换器；极限是连接有限与无限的桥梁。极限与无穷小有着密切的关系，借助于极限，可以深刻地理解无穷小的本质。反过来，无穷小思想也是对极限思想的补充。深刻地理解极限和无穷小的实质，对学习微积分是十分必要的。
Bounds on R-parity Violating Couplings at the Weak Scale and at the GUT Scale
Allanach, Benjamin C; Dreiner, H K
1999-01-01
We present an update of the most stringent experimental bounds on the trilinear R-parity violating couplings. We then analyse bounds on the R-parity violating couplings at the unification scale by renormalising the weak scale bounds. We derive unification scale upper bounds upon the couplings which are broadly independent of the fermion mass texture assumed. The R-parity violating couplings are factors of two to five more severely bounded at the unification scale than at the electroweak scale. In the presence of quark mixing, a few of the bounds are orders of magnitude stronger than their weak scale counterparts due to new R-parity violating operators being induced in the renormalisation between high and low scales. These induced bounds are fermion mass texture dependent. New bounds upon the weak scale couplings are obtained by the requirement of perturbativity between the weak and unification scales. A comprehensive set of the latest limits is included.
Matusov, Eugene; Smith, Mark Philip
2012-09-01
We consider identity as a historically emerging discourse that requires genealogical analysis - not to discover the roots of our identity but to commit [ourselves] to its dissipation (Foucault 1977, p. 162). We suggest analyzing identity through the history of socio-economic classes, their life struggles, ambitions, development, and reproduction. We see learning not as a project of transformation of identity, but rather as developing access to socially valuable practices and developing one's own voice within these practices (through addressing and responding to other voices). The access and voice projects free agents from unnecessary finalization and objectivization by oneself and others (Bakhtin 1999; Bakhtin 1990). In education, we should develop indigenous discourses of learning and develop a conceptual framework that makes analysis of diverse discourses possible. We argue that learning, as transformation of participation in a sociocultural practice to gain more access, is a better conceptual framework than learning as transformation of identity.
Bounds on the Tau Magnetic Moments Standard Model and Beyond
González-Sprinberg, G A; Vidal, J; Gonzalez-Sprinberg, Gabriel A.; Santamaria, Arcadi; Vidal, Jorge
2001-01-01
We obtain new bounds for the magnetic dipole moments of the tau lepton. These limits on the magnetic couplings of the tau to the electroweak gauge bosons (gamma, W, Z) are set in a model independent way using the most general effective Lagrangian with the SU(2)_L x U(1)_Y symmetry. Comparison with data from the most precise experiments at high energies shows that the present limits are more stringent than the previous published ones. For the anomalous magnetic moment the bounds are, for the first time, within one order of magnitude of the standard model prediction.
Statistical Analysis of Thermal Analysis Margin
Garrison, Matthew B.
2011-01-01
NASA Goddard Space Flight Center requires that each project demonstrate a minimum of 5 C margin between temperature predictions and hot and cold flight operational limits. The bounding temperature predictions include worst-case environment and thermal optical properties. The purpose of this work is to: assess how current missions are performing against their pre-launch bounding temperature predictions and suggest any possible changes to the thermal analysis margin rules
New Bounds on the Signed Total Domination Number of Graphs
Directory of Open Access Journals (Sweden)
Moghaddam Seyyed Mehdi Hosseini
2016-05-01
Full Text Available In this paper, we study the signed total domination number in graphs and present new sharp lower and upper bounds for this parameter. For example by making use of the classic theorem of Turán [8], we present a sharp lower bound on Kr+1-free graphs for r ≥ 2. Applying the concept of total limited packing we bound the signed total domination number of G with δ(G ≥ 3 from above by . Also, we prove that γst(T ≤ n − 2(s − s′ for any tree T of order n, with s support vertices and s′ support vertices of degree two. Moreover, we characterize all trees attaining this bound.
Nonlinear Instabilities in Shock-Bounded Slabs
Vishniac, E T
1993-01-01
(substantial changes to section 3.2, otherwise minor) We present an analysis of the hydrodynamic stability of a cold slab bounded by two accretion shocks. Previous numerical work has shown that when the Mach number of the shock is large the slab is unstable. Here we show that to linear order both the bending and breathing modes of such a slab are stable. However, nonlinear effects will tend to soften the restoring forces for bending modes, and when the slab displacement is comparable to its thickness this gives rise to a nonlinear instability. The growth rate of the instability, above this threshold but for small bending angles, is $\\sim c_sk (k\\eta)^{1/2}$, where $\\eta$ is the slab displacement. When the bending angle is large the slab will contain a local vorticity comparable to $c_s/L$, where $L$ is the slab thickness. We discuss the implications of this work for gravitational instabilities of slabs. Finally, we examine the cases of a decelerating slab bounded by a single shock and a stationary slab bounde...
Notes on shear viscosity bound violation in anisotropic models
Ge, Xian-Hui
2015-01-01
The shear viscosity bound violation in Einstein gravity for anisotropic black branes is discussed, with the aim of constraining the deviation of the shear viscosity-entropy density ratio from the shear viscosity bound using causality and thermodynamics analysis. The results show that no stringent constraints can be imposed. The diffusion bound in anisotropic phases is also studied. Ultimately, it is concluded that shear viscosity violation always occurs in cases where the equation of motion of the metric fluctuations cannot be written in a form identical to that of the minimally coupled massless scalar fields.
Market Access through Bound Tariffs
DEFF Research Database (Denmark)
Sala, Davide; Schröder, Philipp J.H.; Yalcin, Erdal
WTO negotiations deal predominantly with bound - besides applied - tariff rates. But, how can reductions in tariffs ceilings, i.e. tariff rates that no exporter may ever actually be confronted with, generate market access? The answer to this question relates to the effects of tariff bindings on t...
Market access through bound tariffs
DEFF Research Database (Denmark)
Sala, Davide; Schröder, Philipp J.H.; Yalcin, Erdal
2010-01-01
WTO negotiations deal predominantly with bound - besides applied - tariff rates. But, how can reductions in tariffs ceilings, i.e. tariff rates that no exporter may ever actually be confronted with, generate market access? The answer to this question relates to the effects of tariff bindings on t...
Unconditional lower bounds against advice
H. Buhrman; L. Fortnow; R. Santhanam
2009-01-01
We show several unconditional lower bounds for exponential time classes against polynomial time classes with advice, including: (1) For any constant c, NEXP not in P^{NP[n^c]} (2) For any constant c, MAEXP not in MA/n^c (3) BPEXP not in BPP/n^{o(1)}. It was previously unknown even whether NEXP in NP
DEFF Research Database (Denmark)
Jarmer, Hanne Østergaard; Berka, R.; Knudsen, Steen;
2002-01-01
DNA microarrays were used to analyze the changes in gene expression in Bacillus subtilis strain 168 when nitrogen limiting (glutamate) and nitrogen excess (ammonium plus glutamate) growth conditions were compared. Among more than 100 genes that were significantly induced during nitrogen starvation...
Macroeconomic effects of CO2 emission limits : A computable general equilibrium analysis for China
Zhang, ZX
1998-01-01
The study analyzes the macroeconomic effects of limiting China's CO2 emissions by using a time-recursive dynamic computable general equilibrium (CGE) model of the Chinese economy. The baseline scenario for the Chinese economy over the period to 2010 is first developed under a set of assumptions abou
Analysis of bifurcations of limit cycles with Lyapunov exponents and numerical normal forms
Witte, de V.; Govaerts, W.; Kuznetsov, Yu.A.; Meijer, H.G.E.
2014-01-01
In this paper we focus on the combination of normal form and Lyapunov exponent computations in the numerical study of the three codim 2 bifurcations of limit cycles with dimension of the center manifold equal to 4 or to 5 in generic autonomous ODEs. The normal form formulas are independent of the di
Cunningham, Charles E.; Rimas, Heather; Mielko, Stephanie; Mapp, Cailin; Cunningham, Lesley; Buchanan, Don; Vaillancourt, Tracy; Chen, Yvonne; Deal, Ken; Marcus, Madalyn
2016-01-01
Prevention programs yield modest reductions in bullying in North American schools. This study explored the perspective of educators regarding factors limiting the impact of these initiatives. Transcripts from nineteen 90-min focus groups with 103 educators were coded thematically. Educators felt that off-site incidents, cyberbullying, and the…
Pareto-Optimal Evaluation of Ultimate Limit States in Offshore Wind Turbine Structural Analysis
Directory of Open Access Journals (Sweden)
Michael Muskulus
2015-12-01
Full Text Available The ultimate capacity of support structures is checked with extreme loads. This is straightforward when the limit state equations depend on a single load component, and it has become common to report maxima for each load component. However, if more than one load component is influential, e.g., both axial force and bending moments, it is not straightforward how to define an extreme load. The combination of univariate maxima can be too conservative, and many different combinations of load components can result in the worst value of the limit state equations. The use of contemporaneous load vectors is typically non-conservative. Therefore, in practice, limit state checks are done for each possible load vector, from each time step of a simulation. This is not feasible when performing reliability assessments and structural optimization, where additional, time-consuming computations are involved for each load vector. We therefore propose to use Pareto-optimal loads, which are a small set of loads that together represent all possible worst case scenarios. Simulations with two reference wind turbines show that this approach can be very useful for jacket structures, whereas the design of monopiles is often governed by the bending moment only. Even in this case, the approach might be useful when approaching the structural limits during optimization.
A Functional Calculus for Quotient Bounded Operators
Directory of Open Access Journals (Sweden)
Sorin Mirel Stoian
2006-12-01
Full Text Available If (X, P is a sequentially locally convex space, then a quotient bounded operator T beloging to QP is regular (in the sense of Waelbroeck if and only if it is a bounded element (in the sense of Allan of algebra QP. The classic functional calculus for bounded operators on Banach space is generalized for bounded elements of algebra QP.
均值有界变差条件及其在Fourier分析中的应用%Mean Bounded Variation Condition and Applications in Fourier Analysis
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
This announcement is to raise an ultimate generalization to monotonicity condition on the Fourier(trigonometric) coefficient sequences.We prove this condition cannot be weakened any further to guarantee the uniform convergence of the sine series.Some interesting and important classical results in Fourier analysis are re-established under this ultimate condition.Over ninty year research history is surveyed in this announcement.The first original paper of this series of papers is posted in arXiv:math.CA/0611805 vl,November 27,2006.
Shape selection of surface-bound helical filaments: biopolymers on curved membranes
Quint, D A; Grason, G M
2016-01-01
Motivated to understand the behavior of biological filaments interacting with membranes of various types, we study a theoretical model for the shape and thermodynamics of intrinsically-helical filaments bound to curved membranes. We show filament-surface interactions lead to a host of non-uniform shape equilibria, in which filaments progressively unwind from their native twist with increasing surface interaction and surface curvature, ultimately adopting uniform-contact curved shapes. The latter effect is due to non-linear coupling between elastic twist and bending of filaments on anisotropically-curved surfaces, such as the cylindrical surfaces considered here. Via a combination of numerical solutions and asymptotic analysis of shape equilibria we show that filament conformations are critically sensitive to the surface curvature in both the strong- and weak-binding limits. These results suggest that local structure of membrane-bound chiral filaments is generically sensitive to the curvature-radius of the sur...
Coefficient of performance and its bounds for general refrigerators with nonisothermal processes
Long, Rui; Liu, Wei
2014-08-01
An analysis of the coefficient of performance (COP) and its bounds at maximum \\chi figure of merit for refrigerators is conducted and the heat transfer processes are described using Newton’s law of cooling with a time-dependent heat conductance. The upper bound of the COP, {{\\varepsilon }_{CA}}=\\sqrt{{{\\varepsilon }_{C}}+1}-1, is independent of the time duration completing either process or the heat conductance. The optimal temperature profiles in the heat exchanging processes are analyzed under different dimensionless contact time limits. Provided the dimensionless contact times satisfy certain relations, the endoreversible model is recovered. Furthermore, numerical calculations are conducted to investigate the effect of different heat conductances on temperature profiles under the maximum \\chi criterion. This work can guide design and operation of actual refrigerators.
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
A new performance analysis method of Optical Code Division Multiple Access (OCDMA) systems with an optical hard-limiter is studied. The bit error probability of the OCDMA system is derived, and the numerical results of the system with and without an ideal optical hard-limiter are analyzed respectively. The results show that although the derived expression is different from the one derived by J A Salehi［1］, the numerical results are the same as those analyzed by J A Salehi, and the numerical result can be easily achieved in this expression.
Quantifying Bounded Rationality: Managerial Behaviour and the Smith Predictor
Riddalls, C.E.; Bennett, S.
2001-01-01
The concept of bounded rationality in decision making and research on its relegation to aggregate system dynamics is examined. By recasting one such example of a dynamic system, the Beer Game, as a Smith predictor control system is derived. A stability analysis is then employed to support the and qualify the assertion that the level of bounded rationality can adversely affect the aggregate dynamic behaviour of such supply chains. The analytical basis of these calculations enables the qualific...
Rudenko, I.; Bekchanov, M.; Djanibekov, U.; Lamers, J. P. A.
2013-11-01
Since independence from the former Soviet Union in 1991, Uzbekistan is challenged to consolidate its efforts and identify and introduce suitable agricultural policies to ease the threat of advancing land, water and ecosystem deterioration. On the one hand, irrigated cotton production provides income, food and energy sources for a large part of the rural households, which accounts for about 70% of the total population. On the other hand, this sector is considered a major driver of the on-going environmental degradation. Due to this dual nature, an integrated approach is needed that allows the analyses of the cotton sector at different stages and, consequently, deriving comprehensive options for action. The findings of the economic based value chain analysis and ecologically-oriented water footprint analysis on regional level were complemented with the findings of an input-output model on national level. This combination gave an added value for better-informed decision-making to reach land, water and ecosystem sustainability, compared to the individual results of each approach. The synergy of approaches pointed at various options for actions, such as to (i) promote the shift of water use from the high water consuming agricultural sector to a less water consuming cotton processing sector, (ii) increase overall water use efficiency by expanding the highly water productive industrial sectors and concurrently decreasing sectors with inefficient water use, and (iii) reduce agricultural water use by improving irrigation and conveyance efficiencies. The findings showed that increasing water use efficiency, manufacturing products with higher value added and raising water users' awareness of the real value of water are essential for providing water security in Uzbekistan.
Shah, Manish B; Wilderman, P Ross; Liu, Jingbao; Jang, Hyun-Hee; Zhang, Qinghai; Stout, C David; Halpert, James R
2015-04-01
X-ray crystal structures of complexes of cytochromes CYP2B6 and CYP2A6 with the monoterpene sabinene revealed two distinct binding modes in the active sites. In CYP2B6, sabinene positioned itself with the putative oxidation site located closer to the heme iron. In contrast, sabinene was found in an alternate conformation in the more compact CYP2A6, where the larger hydrophobic side chains resulted in a significantly reduced active-site cavity. Furthermore, results from isothermal titration calorimetry indicated a much more substantial contribution of favorable enthalpy to sabinene binding to CYP2B6 as opposed to CYP2A6, consistent with the previous observations with (+)-α-pinene. Structural analysis of CYP2B6 complexes with sabinene and the structurally similar (3)-carene and comparison with previously solved structures revealed how the movement of the F206 side chain influences the volume of the binding pocket. In addition, retrospective analysis of prior structures revealed that ligands containing -Cl and -NH functional groups adopted a distinct orientation in the CYP2B active site compared with other ligands. This binding mode may reflect the formation of Cl-π or NH-π bonds with aromatic rings in the active site, which serve as important contributors to protein-ligand binding affinity and specificity. Overall, the findings from multiple techniques illustrate how drugs metabolizing CYP2B6 and CYP2A6 handle a common hydrocarbon found in the environment. The study also provides insight into the role of specific functional groups of the ligand that may influence the binding to CYP2B6.
Analysis of the H-mode density limit in the ASDEX upgrade tokamak using bolometry
Energy Technology Data Exchange (ETDEWEB)
Bernert, Matthias
2013-10-23
The high confinement mode (H-mode) is the operational scenario foreseen for ITER, DEMO and future fusion power plants. At high densities, which are favourable in order to maximize the fusion power, a back transition from the H-mode to the low confinement mode (L-mode) is observed. This H-mode density limit (HDL) occurs at densities on the order of, but below, the Greenwald density. In this thesis, the HDL is revisited in the fully tungsten walled ASDEX Upgrade tokamak (AUG). In AUG discharges, four distinct operational phases were identified in the approach towards the HDL. First, there is a stable H-mode, where the plasma density increases at steady confinement, followed by a degrading H-mode, where the core electron density is fixed and the confinement, expressed as the energy confinement time, reduces. In the third phase, the breakdown of the H-mode and transition to the L-mode, the overall electron density is fixed and the confinement decreases further, leading, finally, to an L-mode, where the density increases again at a steady confinement at typical L-mode values until the disruptive Greenwald limit is reached. These four phases are reproducible, quasi-stable plasma regimes and provide a framework in which the HDL can be further analysed. Radiation losses and several other mechanisms, that were proposed as explanations for the HDL, are ruled out for the current set of AUG experiments with tungsten walls. In addition, a threshold of the radial electric field or of the power flux into the divertor appears to be responsible for the final transition back to L-mode, however, it does not determine the onset of the HDL. The observation of the four phases is explained by the combination of two mechanisms: a fueling limit due to an outward shift of the ionization profile and an additional energy loss channel, which decreases the confinement. The latter is most likely created by an increased radial convective transport at the edge of the plasma. It is shown that the
Analysis of background components in Ge-spectrometry and their influence on detection limits
Energy Technology Data Exchange (ETDEWEB)
Heusser, G. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)
1997-03-01
In low radioactivity measurements the system own background of the spectrometer is, besides the counting efficiency, the limiting factor for the achievable sensitivity. Since the latter is mostly fixed, background reduction is the only way to gain sensitivity, although it is inversely proportional only to the square root of the background rate but directly proportional to the counting efficiency. A thorough understanding of the background sources and their quantitative contribution helps to choose the most adequate suppression method in order to reach a certain required level of detection limit. For Ge-spectrometry the background can be reduced by 5 to 6 orders of magnitude compared to the unshielded case applying state-of-the-art techniques. This reduction factor holds for the continuous background spectrum as well as for the line background as demonstrated for a Ge detector of the Heidelberg-Moscow double beta decay experiment. (orig./DG)
Systematic single-cell analysis of Pichia pastoris reveals secretory capacity limits productivity.
Directory of Open Access Journals (Sweden)
Kerry Routenberg Love
Full Text Available Biopharmaceuticals represent the fastest growing sector of the global pharmaceutical industry. Cost-efficient production of these biologic drugs requires a robust host organism for generating high titers of protein during fermentation. Understanding key cellular processes that limit protein production and secretion is, therefore, essential for rational strain engineering. Here, with single-cell resolution, we systematically analysed the productivity of a series of Pichia pastoris strains that produce different proteins both constitutively and inducibly. We characterized each strain by qPCR, RT-qPCR, microengraving, and imaging cytometry. We then developed a simple mathematical model describing the flux of folded protein through the ER. This combination of single-cell measurements and computational modelling shows that protein trafficking through the secretory machinery is often the rate-limiting step in single-cell production, and strategies to enhance the overall capacity of protein secretion within hosts for the production of heterologous proteins may improve productivity.
Guermond, Jean-Luc
2010-01-01
We revisit some results from M. L. Adams [Nu cl. Sci. Engrg., 137 (2001), pp. 298- 333]. Using functional analytic tools we prove that a necessary and sufficient condition for the standard upwind discontinuous Galerkin approximation to converge to the correct limit solution in the diffusive regime is that the approximation space contains a linear space of continuous functions, and the restrictions of the functions of this space to each mesh cell contain the linear polynomials. Furthermore, the discrete diffusion limit converges in the Sobolev space H1 to the continuous one if the boundary data is isotropic. With anisotropic boundary data, a boundary layer occurs, and convergence holds in the broken Sobolev space H with s < 1/2 only © 2010 Society for Industrial and Applied Mathematics.
Ribeiro, Nuno A; Jorge, Susana M.
2013-01-01
In order to keep local public finances balanced, in many countries, measures restraining and controlling debt have been implemented. In Portugal such concerns have been considered too. Accordingly, several legal diplomas have been passed, namely local finances laws, defining rules, mainly related to limits and restrictions to interest, repayments of borrowings, as well as net debt level. Therefore, it should be expected that these legal restrictions would contribute to reduce municipal deb...
3D edge transport analysis of ITER start-up configuration for limiter power load assessment
Kobayashi, M.; Feng, Y.; Loarte, A.; Federici, G.; Strohmayer, G.; Shimada, M.; Sardei, F.; Reiter, D.; Sugihara, M.
2007-02-01
The edge transport properties of the toroidally discrete limiter configuration in the ITER start-up phase has been analysed, using the 3D edge transport code, EMC3-EIRENE. Because of the finite magnetic shear in the edge, the interaction of the limiters with flux surfaces of different q-values introduces a complex 3D pattern in the connection length (LC) profiles, where long and short flux tubes co-exist in the scrape-off layer. The severity of problems associated with very long flux tubes in the edge, which could bring a large amount of energy (proportional to the square root of LC) and cause a hot spot on the limiter, was mitigated and no significant localized power load was found. This can be justified as follows. (i) For long flux tubes, the perpendicular energy transport time becomes shorter than the parallel energy transport time, resulting in no net energy input to the flux tube. (ii) Perpendicular transport was found to be very effective to smear out the difference in the parallel energy flux conducted by the various flux tubes, if they interact within a perpendicular transport scale, about a few cm, which is usually the case in high plasma current ITER start-up configuration. These two effects significantly reduce the dependence of energy deposition on LC. At the high plasma current (e.g. 6.5 MA), the peak power load is found to be close to the engineering limit, especially for lowest perpendicular transport coefficients and the highest input power. Comparing the results of the 3D modelling with a radial exponential decay model, it was found that by neglecting the 3D geometrical effects, the simple model overestimates the peak power load by ~30% for corresponding input power and radial decay of energy flux.
Limitations and pitfalls of climate change impact analysis on urban rainfall extremes
DEFF Research Database (Denmark)
Willems, P.; Olsson, J.; Arnbjerg-Nielsen, Karsten;
to anthropogenic climate change. Current practices have several limitations and pitfalls, which are important to be considered by trend or climate change impact modellers and users of trend/impact results. Climate change may well be the driver that ensures that changes in urban drainage paradigms are identified...... and suitable solutions implemented. Design and optimization of urban drainage infrastructure considering climate change impacts and co-optimizing with other objectives will become ever more important to keep our cities liveable into the future....
Atmospheric inverse modeling with known physical bounds: an example from trace gas emissions
Directory of Open Access Journals (Sweden)
S. M. Miller
2013-09-01
Full Text Available Many inverse problems in the atmospheric sciences involve parameters with known physical constraints. Examples include non-negativity (e.g., emissions of some urban air pollutants or upward limits implied by reaction or solubility constants. However, probabilistic inverse modeling approaches based on Gaussian assumptions cannot incorporate such bounds and thus often produce unrealistic results. The atmospheric literature lacks consensus on the best means to overcome this problem, and existing atmospheric studies rely on a limited number of the possible methods with little examination of the relative merits of each. This paper investigates the applicability of several approaches to bounded inverse problems and is also the first application of Markov chain Monte Carlo (MCMC to estimation of atmospheric trace gas fluxes. The approaches discussed here are broadly applicable. A common method of data transformations is found to unrealistically skew estimates for the examined example application. The method of Lagrange multipliers and two MCMC methods yield more realistic and accurate results. In general, the examined MCMC approaches produce the most realistic result but can require substantial computational time. Lagrange multipliers offer an appealing alternative for large, computationally intensive problems when exact uncertainty bounds are less central to the analysis. A synthetic data inversion of US anthropogenic methane emissions illustrates the strengths and weaknesses of each approach.
International Nuclear Information System (INIS)
A program that permits the a priori calculation of detection limits in monoelemental matrices, adapted to instrumental neutron activation analysis using a SLOWPOKE II reactor, is described. A simplified model of the gamma spectra is proposed. Products of (n,p) and (n,α) reactions induced by the fast components of the neutron flux that accompanies the thermal flux at the level of internal irradiation sites in the reactor have been included in the list of interfering radionuclides. The program calculates in a systematic way the detection limits of 66 elements in an equal number of matrices using 153 intermediary radionuclides. Experimental checks carried out with silicon (for short lifetimes) and aluminum and magnesium (for intermediate lifetimes) show satisfactory agreement with the calculations. These results show in particular the importance of the contribution of the (n,p) and (n,α) reactions in the a priori evaluation of detection limits with a SLOWPOKE type reactor
Lloyd, Seth
2012-01-01
This letter analyzes the limits that quantum mechanics imposes on the accuracy to which spacetime geometry can be measured. By applying the fundamental physical bounds to measurement accuracy to ensembles of clocks and signals moving in curved spacetime -- e.g., the global positioning system -- I derive a covariant version of the quantum geometric limit: the total number of ticks of clocks and clicks of detectors that can be contained in a four volume of spacetime of radius r and temporal extent t is less than or equal to rt/\\pi x_P t_P, where x_P, t_P are the Planck length and time. The quantum geometric limit bounds the number of events or `ops' that can take place in a four-volume of spacetime: each event is associated with a Planck-scale area. Conversely, I show that if each quantum event is associated with such an area, then Einstein's equations must hold. The quantum geometric limit is consistent with and complementary to the holographic bound which limits the number of bits that can exist within a spat...
Directory of Open Access Journals (Sweden)
Erik Svensjö
2014-01-01
Full Text Available Inhibitors of serine peptidases (ISPs expressed by Leishmania major enhance intracellular parasitism in macrophages by targeting neutrophil elastase (NE, a serine protease that couples phagocytosis to the prooxidative TLR4/PKR pathway. Here we investigated the functional interplay between ISP-expressing L. major and the kallikrein-kinin system (KKS. Enzymatic assays showed that NE inhibitor or recombinant ISP-2 inhibited KKS activation in human plasma activated by dextran sulfate. Intravital microscopy in the hamster cheek pouch showed that topically applied L. major promastigotes (WT and Δisp2/3 mutants potently induced plasma leakage through the activation of bradykinin B2 receptors (B2R. Next, using mAbs against kininogen domains, we showed that these BK-precursor proteins are sequestered by L. major promastigotes, being expressed at higher % in the Δisp2/3 mutant population. Strikingly, analysis of the role of kinin pathway in the phagocytic uptake of L. major revealed that antagonists of B2R or B1R reversed the upregulated uptake of Δisp2/3 mutants without inhibiting macrophage internalization of WT L. major. Collectively, our results suggest that L. major ISP-2 fine-tunes macrophage phagocytosis by inhibiting the pericellular release of proinflammatory kinins from surface bound kininogens. Ongoing studies should clarify whether L. major ISP-2 subverts TLR4/PKR-dependent prooxidative responses of macrophages by preventing activation of G-protein coupled B2R/B1R.
Svensjö, Erik; Nogueira de Almeida, Larissa; Vellasco, Lucas; Juliano, Luiz; Scharfstein, Julio
2014-01-01
Inhibitors of serine peptidases (ISPs) expressed by Leishmania major enhance intracellular parasitism in macrophages by targeting neutrophil elastase (NE), a serine protease that couples phagocytosis to the prooxidative TLR4/PKR pathway. Here we investigated the functional interplay between ISP-expressing L. major and the kallikrein-kinin system (KKS). Enzymatic assays showed that NE inhibitor or recombinant ISP-2 inhibited KKS activation in human plasma activated by dextran sulfate. Intravital microscopy in the hamster cheek pouch showed that topically applied L. major promastigotes (WT and Δisp2/3 mutants) potently induced plasma leakage through the activation of bradykinin B2 receptors (B2R). Next, using mAbs against kininogen domains, we showed that these BK-precursor proteins are sequestered by L. major promastigotes, being expressed at higher % in the Δisp2/3 mutant population. Strikingly, analysis of the role of kinin pathway in the phagocytic uptake of L. major revealed that antagonists of B2R or B1R reversed the upregulated uptake of Δisp2/3 mutants without inhibiting macrophage internalization of WT L. major. Collectively, our results suggest that L. major ISP-2 fine-tunes macrophage phagocytosis by inhibiting the pericellular release of proinflammatory kinins from surface bound kininogens. Ongoing studies should clarify whether L. major ISP-2 subverts TLR4/PKR-dependent prooxidative responses of macrophages by preventing activation of G-protein coupled B2R/B1R. PMID:25294952
Physics with loosely bound nuclei
Indian Academy of Sciences (India)
Chhanda Samanta
2001-08-01
The essential aspect of contemporary physics is to understand properties of nucleonic matter that constitutes the world around us. Over the years research in nuclear physics has provided strong guidance in understanding the basic principles of nuclear interactions. But, the scenario of nuclear physics changed drastically as the new generation of accelerators started providing more and more rare isotopes, which are away from the line of stability. These weakly bound nuclei are found to exhibit new forms of nuclear matter and unprecedented exotic behaviour. The low breakup thresholds of these rare nuclei are posing new challenges to both theory and experiments. Fortunately, nature has provided a few loosely bound stable nuclei that have been studied thoroughly for decades. Attempts are being made to ﬁnd a consistent picture for the unstable nuclei starting from their stable counterparts. Some signiﬁcant differences in the structure and reaction mechanisms are found.
Concentration Bounds for Stochastic Approximations
Frikha, Noufel
2012-01-01
We obtain non asymptotic concentration bounds for two kinds of stochastic approximations. We first consider the deviations between the expectation of a given function of the Euler scheme of some diffusion process at a fixed deterministic time and its empirical mean obtained by the Monte-Carlo procedure. We then give some estimates concerning the deviation between the value at a given time-step of a stochastic approximation algorithm and its target. Under suitable assumptions both concentration bounds turn out to be Gaussian. The key tool consists in exploiting accurately the concentration properties of the increments of the schemes. For the first case, as opposed to the previous work of Lemaire and Menozzi (EJP, 2010), we do not have any systematic bias in our estimates. Also, no specific non-degeneracy conditions are assumed.
An analysis of small target feature detection limits using optic flow
Conroy, Joseph; Gremillion, Gregory; Mathis, Allison; Nothwang, William
2015-05-01
The neurophysiology of insects suggests that they are able to track conspecifics, which manifest as small targets, against a variety of backgrounds with ease. This perception occurs at the same stage as motion perception suggesting a role for optic flow in target discrimination. Optic flow also is an attractive method of perception for visual system design due to the possibility of parallel processing that lends itself to implementation in hardware acceleration. This paper investigates some of the limits for reliable target discrimination solely from an optic flow field which are dependent on algorithm parameters, the nature of the target, and imager noise properties.
Analysis of sputtering from a TiC coated test limiter in the Tokamak de Varennes
International Nuclear Information System (INIS)
An assembly which allows insertion of a test-limiter into a hot plasma has been developed. In addition to its usefulness in the study of various materials, it is also well adapted for measuring the properties of the edge plasma. Measurements of sputtering and power deposition can be used to determine unique values for the plasma density and temperature. In addition, the fluctuations of the radiation from the edge have shown very regular 'sawteeth', which we have correlated with other diagnostics. These display a surprising phase inversion near the edge
Qualitative analysis of the Rössler equations: Bifurcations of limit cycles and chaotic attractors
Barrio, Roberto; Blesa, Fernando; Serrano, Sergio
2009-06-01
In this paper we study different aspects of the paradigmatic Rössler model. We perform a detailed study of the local and global bifurcations of codimension one and two of limit cycles. This provides us a global idea of the three-parametric evolution of the system. We also study the regions of parameters where we may expect a chaotic behavior by the use of different Chaos Indicators. The combination of the different techniques gives an idea of the different routes to chaos and the different kinds of chaotic attractors we may found in this system.
Outage analysis of interference-limited systems using STBC with co-channel MIMO interferers
Institute of Scientific and Technical Information of China (English)
Yongzhao LI; Leonard J.CIMINI,JR.; Nageen HIMAYAT
2009-01-01
The performance of Space-Time Block Coding (STBC) with co-channel MIMO interference is investigated.For an interference-limited environment, the closed-form ex-pressions for the probability density functions of the signal-to-interference ratio are derived and applied to analyze the outage probability with three typical types of co-channel MIMO interferers: STBC, open-loop spatial multiplexing and closed-loop spatial multiplexing. Both theoretical anal-yses and simulation results show that the performance of STBC is independent of the MIMO modes used in the in-terfering links.
On a strong field limit analysis and gravitational lensing of an Ellis wormhole
Tsukamoto, Naoki
2016-01-01
Observations of gravitational lenses in strong gravitational fields will give us a clue for understanding dark compact objects. In this paper, we suggest two small revisions of a method to obtain a deflection angle in a strong field limit provided by Bozza [Phys. Rev. D 66, 103001 (2002)]. First, we correct the order of an error term of the deflection angle. Second, we revise the method to apply to ultrastatic spacetimes. Using the improved method, we consider gravitational lensing by an Ellis wormhole which is an ultrastatic wormhole of the Morris-Thorne class.
Energy Technology Data Exchange (ETDEWEB)
Jardim, J.L.; Macedo, N.J.; Santo, S.E.; Praca, A.S. [FURNAS Centrais Eletricas S.A., Rio de Janeiro, RJ (Brazil)
1994-12-31
The effect of over excitation limiters on power system voltage stability is presented in this paper. A linear analysis based on system eigenvalues for various operating conditions shows that voltage collapse is essentially a dynamic phenomenon. Time simulations using digital tools and real-time simulator were performed to verify lin ear results and study large disturbances. A control system designed to keep system in secure region is proposed. (author) 3 refs., 9 figs.
2013-03-26
... Agency Information Collection Activities; Comment Request; Upward Bound and Upward Bound Math Science... Upward Bound Math Science Annual Performance Report. OMB Control Number: 1840-NEW. Type of Review: New... under the regular Upward Bound (UB) and Upward Bound Math and Science (UBMS) Programs. The Department...
Analysis of enamel development using murine model systems: approaches and limitations.
Directory of Open Access Journals (Sweden)
Megan K Pugach
2014-09-01
Full Text Available A primary goal of enamel research is to understand and potentially treat or prevent enamel defects related to amelogenesis imperfecta (AI. Rodents are ideal models to assist our understanding of how enamel is formed because they are easily genetically modified, and their continuously erupting incisors display all stages of enamel development and mineralization. While numerous methods have been developed to generate and analyze genetically modified rodent enamel, it is crucial to understand the limitations and challenges associated with these methods in order to draw appropriate conclusions that can be applied translationally, to AI patient care. We have highlighted methods involved in generating and analyzing rodent enamel and potential approaches to overcoming limitations of these methods: 1 generating transgenic, knockout and knockin mouse models, and 2 analyzing rodent enamel mineral density and functional properties (structure, mechanics of mature enamel. There is a need for a standardized workflow to analyze enamel phenotypes in rodent models so that investigators can compare data from different studies. These methods include analyses of gene and protein expression, developing enamel histology, enamel pigment, degree of mineralization, enamel structure and mechanical properties. Standardization of these methods with regard to stage of enamel development and sample preparation is crucial, and ideally investigators can use correlative and complementary techniques with the understanding that developing mouse enamel is dynamic and complex.
Olivieri, Giuseppe; Russo, Maria Elena; Marzocchella, Antonio; Salatino, Piero
2011-01-01
A mathematical model of an aerobic biofilm reactor is presented to investigate the bifurcational patterns and the dynamical behavior of the reactor as a function of different key operating parameters. Suspended cells and biofilm are assumed to grow according to double limiting kinetics with phenol inhibition (carbon source) and oxygen limitation. The model presented by Russo et al. is extended to embody key features of the phenomenology of the granular-supported biofilm: biofilm growth and detachment, gas-liquid oxygen transport, phenol, and oxygen uptake by both suspended and immobilized cells, and substrate diffusion into the biofilm. Steady-state conditions and stability, and local dynamic behavior have been characterized. The multiplicity of steady states and their stability depend on key operating parameter values (dilution rate, gas-liquid mass transfer coefficient, biofilm detachment rate, and inlet substrate concentration). Small changes in the operating conditions may be coupled with a drastic change of the steady-state scenario with transcritical and saddle-node bifurcations. The relevance of concentration profiles establishing within the biofilm is also addressed. When the oxygen level in the liquid phase is <10% of the saturation level, the biofilm undergoes oxygen starvation and the active biofilm fraction becomes independent of the dilution rate. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011.
Simple frequency-dependent tools for analysis of inherent control limitations
Directory of Open Access Journals (Sweden)
Sigurd Skogestad
1991-10-01
Full Text Available By a plant's inherent control limitations we mean the characteristics of the plant which will cause poor control performance irrespective of what controller is used. Another frequently used term is 'dynamic resilience' which is the best closed-loop performance achievable using any controller. Since a plant's dynamic resilience cannot be altered by change of the control algorithm, but only by design modifications, it follows that the term controllability provides a link between process design and process control. In this paper we focus on two aspects of controllability. The plants' sensitivity to disturbances and the limitations imposed by interactions when using decentralized control. We use simple tools such as the RGA, the PRGA (Performance RGA and the closely related Closed Loop Disturbance Gain (CLDG. For example, if kth column of the CLDG is large, then this indicates that disturbance k will be difficult to reject. This may pinpoint the need for modifying the process. The PRGA provides a measure of interaction which also includes one-way coupling. In the paper we apply these measures to distillation column control and fluid catalytic cracker (FCC control.
Cosmological stability bound in massive gravity and bigravity
Energy Technology Data Exchange (ETDEWEB)
Fasiello, Matteo; Tolley, Andrew J., E-mail: matte@case.edu, E-mail: andrew.j.tolley@case.edu [CERCA, Department of Physics, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106 (United States)
2013-12-01
We give a simple derivation of a cosmological bound on the graviton mass for spatially flat FRW solutions in massive gravity with an FRW reference metric and for bigravity theories. This bound comes from the requirement that the kinetic term of the helicity zero mode of the graviton is positive definite. The bound is dependent only on the parameters in the massive gravity potential and the Hubble expansion rate for the two metrics. We derive the decoupling limit of bigravity and FRW massive gravity, and use this to give an independent derivation of the cosmological bound. We recover our previous results that the tension between satisfying the Friedmann equation and the cosmological bound is sufficient to rule out all observationally relevant FRW solutions for massive gravity with an FRW reference metric. In contrast, in bigravity this tension is resolved due to different nature of the Vainshtein mechanism. We find that in bigravity theories there exists an FRW solution with late-time self-acceleration for which the kinetic terms for the helicity-2, helicity-1 and helicity-0 are generically nonzero and positive making this a compelling candidate for a model of cosmic acceleration. We confirm that the generalized bound is saturated for the candidate partially massless (bi)gravity theories but the existence of helicity-1/helicity-0 interactions implies the absence of the conjectured partially massless symmetry for both massive gravity and bigravity.
Boonstra, A.; van Offenbeek, M.A.G.
2010-01-01
Telecare is the use of information and communication systems to facilitate care delivery to individuals in their homes. Although the expectations of telecare are high, its implementation has proved complex. This case study demonstrates this complexity through a structurational analysis of a telecare
Limited diagnostic value of enzyme analysis in patients with mitochondrial tRNA mutations
DEFF Research Database (Denmark)
Wibrand, Flemming; Jeppesen, Tina Dysgaard; Frederiksen, Anja L;
2010-01-01
We evaluated the diagnostic value of respiratory chain (RC) enzyme analysis of muscle in adult patients with mitochondrial myopathy (MM). RC enzyme activity was measured in muscle biopsies from 39 patients who carry either the 3243A>G mutation, other tRNA point mutations, or single, large...
An Inequality for the Sum of Independent Bounded Random Variables
Dance, Christopher R.
2012-01-01
We give a simple inequality for the sum of independent bounded random variables. This inequality improves on the celebrated result of Hoeffding in a special case. It is optimal in the limit where the sum tends to a Poisson random variable.
Higgs interchange and bound states of superheavy fermions
Indian Academy of Sciences (India)
M De Sanctis
2013-09-01
Hypothetical superheavy fourth-generation fermions with a very small coupling with the rest of the Standard Model can give rise to long enough lived bound states. The production and the detection of these bound states would be experimentally feasible at the LHC. Extending, in the present study, the analysis of other authors, a semirelativistic wave equation is solved using an accurate numerical method to determine the binding energies of these possible superheavy fermion-bound states. The interaction given by the Yukawa potential of the Higgs boson exchange is considered; the corresponding relativistic corrections are calculated by means of a model based on the covariance properties of the Hamiltonian. We study the effects given by the Coulomb force. Moreover, we calculate the contributions given by the Coulombic and confining terms of the strong interaction in the case of superheavy quark bound states. The results of the model are critically analysed.
Evidence for soft bounds in Ubuntu package sizes and mammalian body masses.
Gherardi, Marco; Mandrà, Salvatore; Bassetti, Bruno; Cosentino Lagomarsino, Marco
2013-12-24
The development of a complex system depends on the self-coordinated action of a large number of agents, often determining unexpected global behavior. The case of software evolution has great practical importance: knowledge of what is to be considered atypical can guide developers in recognizing and reacting to abnormal behavior. Although the initial framework of a theory of software exists, the current theoretical achievements do not fully capture existing quantitative data or predict future trends. Here we show that two elementary laws describe the evolution of package sizes in a Linux-based operating system: first, relative changes in size follow a random walk with non-Gaussian jumps; second, each size change is bounded by a limit that is dependent on the starting size, an intriguing behavior that we call "soft bound." Our approach is based on data analysis and on a simple theoretical model, which is able to reproduce empirical details without relying on any adjustable parameter and generates definite predictions. The same analysis allows us to formulate and support the hypothesis that a similar mechanism is shaping the distribution of mammalian body sizes, via size-dependent constraints during cladogenesis. Whereas generally accepted approaches struggle to reproduce the large-mass shoulder displayed by the distribution of extant mammalian species, this is a natural consequence of the softly bounded nature of the process. Additionally, the hypothesis that this model is valid has the relevant implication that, contrary to a common assumption, mammalian masses are still evolving, albeit very slowly.
Bounded Delay Packet Scheduling in a Bounded Buffer
Fung, Stanley P Y
2009-01-01
We study the problem of buffer management in QoS-enabled network switches in the bounded delay model where each packet is associated with a weight and a deadline. We consider the more realistic situation where the network switch has a finite buffer size. A 9.82-competitive algorithm is known for the case of multiple buffers (Azar and Levy, SWAT'06). Recently, for the case of a single buffer, a 3-competitive deterministic algorithm and a 2.618-competitive randomized algorithm was known (Li, INFOCOM'09). In this paper we give a simple deterministic 2-competitive algorithm for the case of a single buffer.
JET-ISX-B beryllium limiter experiment safety analysis report and operational safety requirements
International Nuclear Information System (INIS)
An experiment to evaluate the suitability of beryllium as a limiter material has been completed on the ISX-B tokamak. The experiment consisted of two phases: (1) the initial operation and characterization in the ISX experiment, and a period of continued operation to the specified surface fluence (1022 atoms/cm2) of hydrogen ions; and (2) the disassembly, decontamination, or disposal of the ISX facility. During these two phases of the project, the possibility existed for beryllium and/or beryllium oxide powder to be produced inside the vacuum vessel. Beryllium dust is a highly toxic material, and extensive precautions are required to prevent the release of the beryllium into the experimental work area and to prevent the contamination of personnel working on the device. Details of the health hazards associated with beryllium and the appropriate precautions are presented. Also described in appendixes to this report are the various operational safety requirements for the project
Analysis of patterns formed by two-component diffusion limited aggregation.
Postnikov, E B; Ryabov, A B; Loskutov, A
2010-11-01
We consider diffusion limited aggregation of particles of two different kinds. It is assumed that a particle of one kind may adhere only to another particle of the same kind. The particles aggregate on a linear substrate which consists of periodically or randomly placed particles of different kinds. We analyze the influence of initial patterns on the structure of growing clusters. It is shown that at small distances from the substrate, the cluster structures repeat initial patterns. However, starting from a critical distance the initial periodicity is abruptly lost, and the particle distribution tends to a random one. An approach describing the evolution of the number of branches is proposed. Our calculations show that the initial pattern can be detected only at the distance which is not larger than approximately one and a half of the characteristic pattern size. PMID:21230475
Langevin analysis of fundamental noise limits in coherent anti-Stokes Raman spectroscopy
International Nuclear Information System (INIS)
We use a Langevin approach to analyze the quantum noise in coherent anti-Stokes Raman spectroscopy in several experimental scenarios: with continuous-wave input fields acting simultaneously and with fast sequential pulsed lasers where one field scatters off the coherence generated by other fields and for interactions within a cavity and in free space. In all cases, the signal and quantum noise due to spontaneous decay and decoherence in the medium are shown to be described by the same general expression. Our theory in particular shows that for short interaction times, the medium noise is not important and the efficiency is limited only by the intrinsic quantum nature of the photon. We obtain fully analytic results without making an adiabatic approximation; the fluctuations of the medium and the fields are solved self-consistently
Analysis of Dα(Hα) spectrum emitted in front of the limiter in HT-7
Institute of Scientific and Technical Information of China (English)
Huang Juan; Wan Bao-Nian; Deren Stotler; Xiao Bing-Jia; Wu Zhen-Wei; the HT-7 team
2008-01-01
In order to understand the recycling and emission processes of hydrogen atoms in HT-7, spectral profiles of the Dα(Hα) line emitted in front of the limiter have been observed with a high-resolution spectrometer and simulated by using the neutral particle transport code DEGAS 2. The results show that four processes are necessary to interpret the Dα(Hα) line shape: 1) atom desorption, 2) molecular dissociation, 3) particle reflection, and 4) charge-exchange. The products of the first two processes are cold atoms which emit photons near the peak of Dα(Hα) line shape, and those from the last two are warm atoms contributing to the blue side of the spectrum. For a typical ohmic discharge (shot 68520 he(0) ≈ 3 × 1019 m-3), these components contribute 32%, 15%, 32% and 21%, respectively. Dα(Hα) line shapes under different plasma parameters are also discussed in this paper.
Single-shot diffraction-limited imaging through scattering layers via bispectrum analysis
Wu, Tengfei; Shao, Xiaopeng; Gigan, Sylvain
2016-01-01
Recently introduced speckle-correlations based techniques enable noninvasive imaging of objects hidden behind scattering layers. In these techniques the hidden object Fourier amplitude is retrieved from the scattered light autocorrelation, and the lost Fourier phase is recovered via iterative phase-retrieval algorithms, which suffer from convergence to wrong local-minima solutions and cannot solve ambiguities in object-orientation. Here, inspired by notions used in astronomy, we experimentally demonstrate that in addition to Fourier amplitude, the object phase information is naturally and inherently encoded in scattered light bispectrum (the Fourier transform of triple-correlation), and can also be extracted from a single high-resolution speckle pattern, based on which we present a single-shot imaging scheme to deterministically and unambiguously retrieve diffraction-limited images of objects hidden behind scattering layers.
Analysis of the Possibility and Limitation of Criminal Mediation in Rural Areas in China
Directory of Open Access Journals (Sweden)
Hao Guo
2014-04-01
Full Text Available With the development in the theory and practice in the area of criminal law in China, a lot of creative views have been put into legal practice. Criminal mediation, which is cropping up in both practice and theory becomes a hot subject under discussion in the field of legislation. The newly modified criminal law formally prescribes the criminal mediation, which has been recognized in the level of law-making. It has become a basic policy in the procedure of law suit. This thesis emphasizes the possibility of criminal mediation in rural areas in China, discussing the disadvantages of the current criminal justice mode, the advantages of criminal mediation and the tradition in rural areas in China. Additionally, it attempts to set up the limitation of criminal mediation, based on the principle of law, principle of equality, principle of utility and principle of justice.
Analysis of safety limits of the Moroccan TRIGA MARK II research reactor
Erradi, L.; Essadki, H.
2001-06-01
The main objective of this study is to check the ability of the Moroccan TRIGA MARK II research reactor, designed to use natural convection cooling, to operate at its nominal power (2 MW) with sufficient safety margins. The neutronic analysis of the core has been performed using Leopard and Mcrac codes and the parameters of interest were the power distributions, the power peaking factors and the core excess reactivity. The thermal hydraulic analysis of the TRIGA core was performed using the French code FLICA designed for transient and study state situations. The main safety related parameters of the core have been evaluated with special emphasises on the following: maximum fuel temperature, minimum DNBR and maximum void fraction. The obtained results confirm the designer predictions except for the void fraction.
X-Ray Cross-Correlation Analysis of Disordered Ensembles of Particles: Potentials and Limitations
Directory of Open Access Journals (Sweden)
R. P. Kurta
2013-01-01
Full Text Available Angular X-ray cross-correlation analysis (XCCA is an approach to study the structure of disordered systems using the results of X-ray scattering experiments. In this paper we summarize recent theoretical developments related to the Fourier analysis of the cross-correlation functions. Results of our simulations demonstrate the application of XCCA to two- and three-dimensional (2D and 3D disordered ensembles of particles. We show that the structure of a single particle can be recovered using X-ray data collected from a 2D disordered system of identical particles. We also demonstrate that valuable structural information about the local structure of 3D systems, inaccessible from a standard small-angle X-ray scattering experiment, can be resolved using XCCA.
Analysis of safety limits of the Moroccan TRIGA MARK II research reactor
International Nuclear Information System (INIS)
The main objective of this study is to check the ability of the Moroccan TRIGA MARK II research reactor, designed to use natural convection cooling, to operate at its nominal power (2 MW) with sufficient safety margins. The neutronic analysis of the core has been performed using Leopard and Mcrac codes and the parameters of interest were the power distributions, the power peaking factors and the core excess reactivity. The thermal hydraulic analysis of the TRIGA core was performed using the French code FLICA designed for transient and study state situations. The main safety related parameters of the core have been evaluated with special emphasises on the following: maximum fuel temperature, minimum DNBR and maximum void fraction. The obtained results confirm the designer predictions except for the void fraction.
Nanogram-Scale Preparation and NMR Analysis for Mass-Limited Small Volatile Compounds
Nojima, Satoshi; Kiemle, David J.; Francis X Webster; Apperson, Charles S.; Schal, Coby
2011-01-01
Semiochemicals are often produced in infinitesimally small quantities, so their isolation requires large amounts of starting material, not only requiring significant effort in sample preparation, but also resulting in a complex mixture of compounds from which the bioactive compound needs to be purified and identified. Often, compounds cannot be unambiguously identified by their mass spectra alone, and NMR analysis is required for absolute chemical identification, further exacerbating the situ...
Hasmats, Johanna; Green, Henrik; Solnestam, Beata Werne; Zajac, Pawel; Huss, Mikael; Orear, Cedric; Validire, Pierre; Bjursell, Magnus; Lundeberg, Joakim
2012-08-24
Personalized cancer treatment requires molecular characterization of individual tumor biopsies. These samples are frequently only available in limited quantities hampering genomic analysis. Several whole genome amplification (WGA) protocols have been developed with reported varying representation of genomic regions post amplification. In this study we investigate region dropout using a φ29 polymerase based WGA approach. DNA from 123 lung cancers specimens and corresponding normal tissue were used and evaluated by Sanger sequencing of the p53 exons 5-8. To enable comparative analysis of this scarce material, WGA samples were compared with unamplified material using a pooling strategy of the 123 samples. In addition, a more detailed analysis of exon 7 amplicons were performed followed by extensive cloning and Sanger sequencing. Interestingly, by comparing data from the pooled samples to the individually sequenced exon 7, we demonstrate that mutations are more easily recovered from WGA pools and this was also supported by simulations of different sequencing coverage. Overall this data indicate a limited random loss of genomic regions supporting the use of whole genome amplification for genomic analysis.
Sharp Bounds by Probability-Generating Functions and Variable Drift
DEFF Research Database (Denmark)
Doerr, Benjamin; Fouz, Mahmoud; Witt, Carsten
2011-01-01
We introduce to the runtime analysis of evolutionary algorithms two powerful techniques: probability-generating functions and variable drift analysis. They are shown to provide a clean framework for proving sharp upper and lower bounds. As an application, we improve the results by Doerr et al...
On an exponential bound for the Kaplan-Meier estimator.
Wellner, Jon A
2007-12-01
We review limit theory and inequalities for the Kaplan-Meier Kaplan and Meier (J Am Stat Assoc 53:457-481, 1958) product limit estimator of a survival function on the whole line [Formula: see text] . Along the way we provide bounds for the constant in an interesting inequality due to Biotouzé et al. (Ann Inst H Poincaré Probab Stat 35:735-763, 1999), and provide some numerical evidence in support of one of their conjectures.
Containing Internal Diffusion Limited Aggregation
Duminil-Copin, Hugo; Yadin, Ariel; Yehudayoff, Amir
2011-01-01
Internal Diffusion Limited Aggregation (IDLA) is a model that describes the growth of a random aggregate of particles from the inside out. Shellef proved that IDLA processes on supercritical percolation clusters of integer-lattices fill Euclidean balls, with high probability. In this article, we complete the picture and prove a limit-shape theorem for IDLA on such percolation clusters, by providing the corresponding upper bound. The technique to prove upper bounds is new and robust: it only requires the existence of a "good" lower bound. Specifically, this way of proving upper bounds on IDLA clusters is more suitable for random environments than previous ways, since it does not harness harmonic measure estimates.
International Nuclear Information System (INIS)
This work is dedicated study of a problem resulting from plasma physics: the thermal transfer of electrons in a plasma close to equilibrium Maxwellian. Firstly, a dimensional study of the Vlasov-Fokker-Planck-Maxwell system is performed, allowing one hand to identify a physically relevant parameter of scale and also to define mathematically the contours of validity domain. The asymptotic regime called Spitzer-Harm is studied for a relatively general class of collision operator. The following part of this work is devoted to the derivation and study of the hydrodynamic limit of the system of Vlasov-Maxwell-Landau outside the strictly asymptotic. A model proposed by Schurtz and Nicolais located in this context and analyzed. The particularity of this model lies in the application of a delocalization operation in the heat flux. The link with non-local models of Luciani and Mora is established as well as mathematics properties as the principle of maximum and entropy dissipation. Then a formal derivation from the Vlasov equations with a simplified collision operator, is proposed. The derivation, inspired by the recent work of D. Levermore, involves decomposition methods according to the spherical harmonics and methods of closing called diffusion methods. A hierarchy of intermediate models between the kinetic equations and the hydrodynamic limit is described. In particular a new hydrodynamic system integro-differential by nature, is proposed. The Schurtz and Nicolai model appears as a simplification of the system resulting from the derivation, assuming a steady flow of heat. The above results are then generalized to account for the internal energy dependence which appears naturally in the equation establishment. The existence and uniqueness of the solution of the nonstationary system are established in a simplified framework. The last part is devoted was the implementation of a specific numerical scheme to solve these models. We propose a finite volume approach can be
Bounding biomass in the Fisher equation
Birch, Daniel A; Young, William R
2007-01-01
The FKPP equation with a variable growth rate and advection by an incompressible velocity field is considered as a model for plankton dispersed by ocean currents. If the average growth rate is negative then the model has a survival-extinction transition; the location of this transition in the parameter space is constrained using variational arguments and delimited by simulations. The statistical steady state reached when the system is in the survival region of parameter space is characterized by integral constraints and upper and lower bounds on the biomass and productivity that follow from variational arguments and direct inequalities. In the limit of zero-decorrelation time the velocity field is shown to act as Fickian diffusion with an eddy diffusivity much larger than the molecular diffusivity and this allows a one-dimensional model to predict the biomass, productivity and extinction transitions. All results are illustrated with a simple growth and stirring model.
Holographic bound in covariant loop quantum gravity
Tamaki, Takashi
2016-01-01
We investigate puncture statistics based on the covariant area spectrum in loop quantum gravity. First, we consider Maxwell-Boltzmann statistics with a Gibbs factor for punctures. We establish formulae which relate physical quantities such as horizon area to the parameter characterizing holographic degrees of freedom. We also perform numerical calculations and obtain consistency with these formulae. These results tell us that the holographic bound is satisfied in the large area limit and correction term of the entropy-area law can be proportional to the logarithm of the horizon area. Second, we also consider Bose-Einstein statistics and show that the above formulae are also useful in this case. By applying the formulae, we can understand intrinsic features of Bose-Einstein condensate which corresponds to the case when the horizon area almost consists of punctures in the ground state. When this phenomena occurs, the area is approximately constant against the parameter characterizing the temperature. When this ...
Helioscope bounds on hidden sector photons
Energy Technology Data Exchange (ETDEWEB)
Redondo, J.
2007-12-15
The flux of hypothetical ''hidden photons'' from the Sun is computed under the assumption that they interact with normal matter only through kinetic mixing with the ordinary standard model photon. Requiring that the exotic luminosity is smaller than the standard photon luminosity provides limits for the mixing parameter down to {chi}
Lower Complexity Bounds for Lifted Inference
Jaeger, Manfred
2012-01-01
One of the big challenges in the development of probabilistic relational (or probabilistic logical) modeling and learning frameworks is the design of inference techniques that operate on the level of the abstract model representation language, rather than on the level of ground, propositional instances of the model. Numerous approaches for such "lifted inference" techniques have been proposed. While it has been demonstrated that these techniques will lead to significantly more efficient inference on some specific models, there are only very recent and still quite restricted results that show the feasibility of lifted inference on certain syntactically defined classes of models. Lower complexity bounds that imply some limitations for the feasibility of lifted inference on more expressive model classes were established early on in (Jaeger 2000). However, it is not immediate that these results also apply to the type of modeling languages that currently receive the most attention, i.e., weighted, quantifier-free ...
On the statistical-mechanical meaning of the Bousso bound
International Nuclear Information System (INIS)
The Bousso entropy bound, in its generalized form, is investigated for the case of perfect fluids at local thermodynamic equilibrium and evidence is found that the bound is satisfied if and only if a certain local thermodynamic property holds, emerging when the attempt is made to apply the bound to thin layers of matter. This property consists of the existence of an ultimate lower limit l* to the thickness of the slices for which a statistical-mechanical description is viable, depending l* on the thermodynamical variables which define the state of the system locally. This limiting scale, found to be in general much larger than the Planck scale (so that no Planck scale physics must be necessarily invoked to justify it), appears not related to gravity and this suggests that the generalized entropy bound is likely to be rooted on conventional flat-spacetime statistical mechanics, with the maximum admitted entropy being however actually determined also by gravity. Some examples of ideal fluids are considered in order to identify the mechanisms which can set a lower limit to the statistical-mechanical description and these systems are found to respect the lower limiting scale l*. The photon gas, in particular, appears to seemingly saturate this limiting scale and the consequence is drawn that for systems consisting of a single slice of a photon gas with thickness l*, the generalized Bousso bound is saturated. It is argued that this seems to open the way to a peculiar understanding of black hole entropy: if an entropy can meaningfully (i.e. with a second law) be assigned to a black hole, the value A/4 for it (where A is the area of the black hole) is required simply by (conventional) statistical mechanics coupled to general relativity
Energy Technology Data Exchange (ETDEWEB)
Huesemann, Michael H.(BATTELLE (PACIFIC NW LAB))
2000-12-01
It is currently believed that science and technology can provide effective solutions to most, if not all, environmental problems facing western industrial societies. The validity of this optimistic assumption is highly questionable for at least three reasons: First, current mechanistic, reductionist science is inherently incapable of providing the complete and accurate information which is required to successfully address environmental problems. Second, both the conservation of mass principle and the second law of thermodynamics dictate that most remediation technologies - while successful in solving specific pollution problems - cause unavoidable negative environmental impacts elsewhere or in the future. Third, it is intrinsically impossible to design industrial processes that have no negative environmental impacts. This follows not only from the entropy law but also from the fact that any generation of energy is impossible without negative environmental consequences. It can therefore be concluded that science and technology have only very limited potential in solving current and future environmental problems. Consequently, it will be necessary to address the root cause of environmental deterioration, namely the prevailing materialistic values that are the main driving force for both overpopulation and overconsumption. The long-term protection of the environment is therefore not primarily a technical problem but rather a social and moral problem that can only be solved by drastically reducing the strong influence of materialistic values.
Continuum modeling and limit equilibrium analysis of slope movement due to rainfall infiltration
Borja, Ronaldo; White, Joshua; Wu, Wei
2010-05-01
Hydrologically-driven landslides and debris flows are highly destructive events that threaten lives and critical infrastructure worldwide. Despite decades of extensive slope stability model development, the fundamental controls connecting the hydrologic and geotechnical processes that trigger slope failure are not well quantified. We use a fully coupled, physics-based finite element model to address this shortcoming. We develop and test a 3D continuum slope-deformation model that couples solid-deformation with fluid-flow processes in variably saturated soils, and assess the capability of the coupled model to predict stresses and deformation necessary to trigger slope failure. We then compare the continuum model with traditional limit equilibrium solutions based on the modified Bishop method of slices to assess the stability of the slope as a function of rainfall infiltration using a scalar stability indicator called factor of safety. For this assessment, we use extensive measurements from a densely instrumented mountain slope (The Coos Bay Experimental Catchment) where a large, rainfall-triggered slope failure occurred. The use of sophisticated, fully coupled numerical simulations combined with comprehensive field-measurements provides an unprecedented opportunity to advance the state of understanding of landslide failure processes and effective mitigation measures.
OBT analysis method using polyethylene beads for limited quantities of animal tissue
International Nuclear Information System (INIS)
This study presents a polyethylene beads method for OBT determination in animal tissues and animal products for cases where the amount of water recovered by combustion is limited by sample size or quantity. In the method, the amount of water recovered after combustion is enhanced by adding tritium-free polyethylene beads to the sample prior to combustion in an oxygen bomb. The method reduces process time by allowing the combustion water to be easily collected with a pipette. Sufficient water recovery was achieved using the polyethylene beads method when 2 g of dry animal tissue or animal product were combusted with 2 g of polyethylene beads. Correction factors, which account for the dilution due to the combustion water of the beads, are provided for beef, chicken, pork, fish and clams, as well as egg, milk and cheese. The method was tested by comparing its OBT results with those of the conventional method using animal samples collected on the Chalk River Laboratories (CRL) site. The results determined that the polyethylene beads method added no more than 25% uncertainty when appropriate correction factors are used. - Highlights: • Polyethylene beads method for OBT determination in animal tissues and animal products were determined. • The method reduces process time. • The polyethylene beads method added no more than 25% uncertainty when appropriate correction factors are used
Directory of Open Access Journals (Sweden)
Z. Zong
2000-01-01
Full Text Available Biodynamic response of shipboard crew to underwater shock is of a major concern to navies. An underwater shock can produce very high accelerations, resulting in severe human injuries aboard a battleship. Protection of human bodies from underwater shock is implemented by installing onboard isolators. In this paper, the optimal underwater shock isolation to protect human bodies is studied. A simple shock-structure-isolator-human interaction model is first constructed. The model incorporates the effect of fluid-structure interaction, biodynamic response of human body, isolator influence. Based on this model, the optimum shock isolation is then formulated. The performance index and restriction are defined. Thirdly, GA (genetic algorithm is employed to solve the formulated optimization problem. GA is a powerful evolutionary optimization scheme suitable for large-scale and multi-variable optimization problems that are otherwise hard to be solved by conventional methods. A brief introduction to GA is given in the paper. Finally, the method is applied to an example problem and the limiting performance characteristic is obtained.
A linear perturbation analysis of magnetopause motion in the Newton-Busemann limit
Directory of Open Access Journals (Sweden)
M. P. Freeman
Full Text Available The response of the magnetopause surface to time-varying solar wind dynamic pressure is examined. We argue that to a first approximation the magnetopause surface may be considered as analogous to an elastic membrane. Upon displacement from equilibrium resulting from a change in applied external pressure, it moves to a new equilibrium under the equation of motion of a forced, damped, simple harmonic oscillator. We derive this equation of motion by linearising for small perturbations the momentum equation for flow past a nonrigid ellipsoidal body in the Newton-Busemann limit. Though our approach is only an approximation to the real dynamics of the magnetopause boundary, it serves to demonstrate the importance of inertia in the system response. It allows us to estimate the natural eigenperiod of magnetopause oscillation as typically around 7 min, the precise value depending on solar wind conditions. However, the magnetopause eigenoscillation is furthermore found to be strongly damped, regardless of solar wind conditions. One consequence of these properties is that short-period fluctuations in the solar wind dynamic pressure elicit a suppressed magnetospheric response. We outline other theoretical expectations by which our model may be tested against observation, and discuss the implications of our findings for current interpretations of spacecraft observations made in the dynamic magnetopause environment.
Directory of Open Access Journals (Sweden)
George Vosselman
2009-07-01
Full Text Available With the increasing point densities provided by airborne laser scanner (ALS data the requirements on derived products also increase. One major application of ALS data is to provide input for 3D city models. Modeling of roof faces, (3D road and terrain surfaces can partially be done in an automated manner, although many such approaches are still in a development stage. Problems in automatic building reconstruction lie in the dynamic area between assumptions and reality. Not every object in the data appears as the algorithm expects. Challenges are to detect areas that cannot be reconstructed automatically. This paper describes our contribution to the field of building reconstruction by proposing a target based graph matching approach that can handle both complete and incomplete laser data. Match results describe which target objects appear topologically in the data. Complete match results can be reconstructed in an automated manner. Quality parameters store information on how the model fits to the input data and which data has not been used. Areas where laser data only partly matches with target objects are detected automatically. Four datasets are analyzed in order to describe the quality of the automatically reconstructed roofs, and to point out the reasons why segments are left out from the automatic reconstruction. The reasons why these areas are left out include lack of data information and limitations of our initial target objects. Potential improvement to our approach is to include likelihood functions to the existence of topological relations.
Directory of Open Access Journals (Sweden)
Sven Stringer
Full Text Available Complex diseases are often highly heritable. However, for many complex traits only a small proportion of the heritability can be explained by observed genetic variants in traditional genome-wide association (GWA studies. Moreover, for some of those traits few significant SNPs have been identified. Single SNP association methods test for association at a single SNP, ignoring the effect of other SNPs. We show using a simple multi-locus odds model of complex disease that moderate to large effect sizes of causal variants may be estimated as relatively small effect sizes in single SNP association testing. This underestimation effect is most severe for diseases influenced by numerous risk variants. We relate the underestimation effect to the concept of non-collapsibility found in the statistics literature. As described, continuous phenotypes generated with linear genetic models are not affected by this underestimation effect. Since many GWA studies apply single SNP analysis to dichotomous phenotypes, previously reported results potentially underestimate true effect sizes, thereby impeding identification of true effect SNPs. Therefore, when a multi-locus model of disease risk is assumed, a multi SNP analysis may be more appropriate.
Mazzanti, Morena; Alessandrini, Federica; Tagliabracci, Adriano; Wells, Jeffrey D; Campobasso, Carlo P
2010-02-25
Puparial cases are common remnants of necrophagous flies in crime investigations. They usually represent the longest developmental time and, therefore, they can be very useful for the estimation of the post-mortem interval (PMI). However, before any PMI estimate, it is crucial to identify the species of fly eclosed from each puparium associated with the corpse. Morphological characteristics of the puparium are often distinctive enough to permit a species identification. But, even an accurate morphological analysis of empty puparia cannot discriminate among different species of closely related flies. Furthermore, morphological identification may be impossible if the fly puparia are poorly preserved or in fragments. This study explores the applicability of biomolecular techniques on empty puparia and their fragments for identification purposes. A total of 63 empty puparia of necrophagous Diptera resulting from forensic casework were examined. Samples were divided into three groups according to size, type and time of eclosion in order to verify whether the physical characteristics and puparia weathering can influence the amount of DNA extraction. The results suggest that a reliable genetic identification of forensically important flies may also be performed from empty puparia and/or their fragments. However, DNA degradation can deeply compromise the genetic analysis since the older the fly puparia, the smaller are the amplified fragments.
Advantages and limitations of potential methods for the analysis of bacteria in milk: a review.
Tabit, Frederick Tawi
2016-01-01
Contamination concerns in the dairy industry are motivated by outbreaks of disease in humans and the inability of thermal processes to eliminate bacteria completely in processed products. HACCP principles are an important tool used in the food industry to identify and control potential food safety hazards in order to meet customer demands and regulatory requirements. Milk testing is of importance to the milk industry regarding quality assurance and monitoring of processed products by researchers, manufacturers and regulatory agencies. Due to the availability of numerous methods used for analysing the microbial quality of milk in literature and differences in priorities of stakeholders, it is sometimes confusing to choose an appropriate method for a particular analysis. The objective of this paper is to review the advantages and disadvantages of selected techniques that can be used in the analysis of bacteria in milk. SSC, HRMA, REP, and RAPD are the top four techniques which are quick and cost-effective and possess adequate discriminatory power for the detection and profiling of bacteria. The following conclusions were arrived at during this review: HRMA, REP and RFLP are the techniques with the most reproducible results, and the techniques with the most discriminatory power are AFLP, PFGE and Raman Spectroscopy. PMID:26787931
Cavanagh, Jorunn Pauline; Klingenberg, Claus; Hanssen, Anne-Merethe; Fredheim, Elizabeth Aarag; Francois, Patrice; Schrenzel, Jacques; Flægstad, Trond; Sollid, Johanna Ericson
2012-06-01
The notoriously multi-resistant Staphylococcus haemolyticus is an emerging pathogen causing serious infections in immunocompromised patients. Defining the population structure is important to detect outbreaks and spread of antimicrobial resistant clones. Currently, the standard typing technique is pulsed-field gel electrophoresis (PFGE). In this study we describe novel molecular typing schemes for S. haemolyticus using multi locus sequence typing (MLST) and multi locus variable number of tandem repeats (VNTR) analysis. Seven housekeeping genes (MLST) and five VNTR loci (MLVF) were selected for the novel typing schemes. A panel of 45 human and veterinary S. haemolyticus isolates was investigated. The collection had diverse PFGE patterns (38 PFGE types) and was sampled over a 20 year-period from eight countries. MLST resolved 17 sequence types (Simpsons index of diversity [SID]=0.877) and MLVF resolved 14 repeat types (SID=0.831). We found a low sequence diversity. Phylogenetic analysis clustered the isolates in three (MLST) and one (MLVF) clonal complexes, respectively. Taken together, neither the MLST nor the MLVF scheme was suitable to resolve the population structure of this S. haemolyticus collection. Future MLVF and MLST schemes will benefit from addition of more variable core genome sequences identified by comparing different fully sequenced S. haemolyticus genomes. PMID:22484086
Strength and limits using 13C phospholipid fatty acid analysis in soil ecology
Watzinger, Andrea
2016-04-01
This presentation on microbial phospholipid biomarkers, their isotope analysis and their ability to reveal soil functions summarizes experiences gained by the author for more than 10 years. The amount and composition of phospholipid fatty acids (PLFAs) measured in environmental samples strongly depend on the methodology. To achieve comparable results the extraction, separation and methylation method must be kept constant. PLFAs patterns are sensitive to microbial community shifts even though the taxonomic resolution of PLFAs is low. The possibility to easily link lipid biomarkers with stable isotope techniques is identified as a major advantage when addressing soil functions. Measurement of PLFA isotopic ratios is sensitive and enables detecting isotopic fractionation. The difference between the carbon isotopic ratio of single PLFAs and their substrate (δ13C) can vary between -6 and +11‰. This difference derives from the fractionation during biosynthesis and from substrate inhomogeneity. Consequently, natural abundance studies are restricted to quantifying substrate uptake of the total microbial biomass. In contrast, artificial labelling enables quantifying carbon uptake into single PLFAs, but labelling success depends on homogeneous and undisturbed label application. Current developments in microbial ecology (e.g. 13C and 15N proteomics) and isotope techniques (online monitoring of CO2 isotope ratios) will likely improve soil functional interpretations in the future. 13C PLFA analysis will continue to contribute because it is affordable, sensitive and allows frequent sampling combined with the use of small amounts of 13C label.
Bound Polaron Pair Formation in Poly (phenylenevinylenes)
Rothberg, Lewis
The following sections are included: * INTRODUCTION * PHOTOGENERATED YIELD OF SINGLET EXCITONS * AGGREGRATION EFFECTS ON EXCITED STATE PHOTO-GENERATION * ASSIGNMENT TO BOUND POLARON PAIRS AND DISCUSSION * PROBLEMS WITH THE BOUND POLARON PAIR PICTURE AND CONCLUSION * REFERENCES
An Exponential Bound for Cox Regression☆
Kosorok, M. R.
2012-01-01
We present an asymptotic exponential bound for the deviation of the survival function estimator of the Cox model. We show that the bound holds even when the proportional hazards assumption does not hold. PMID:23565013
An Exponential Bound for Cox Regression.
Goldberg, Y; Kosorok, M R
2012-07-01
We present an asymptotic exponential bound for the deviation of the survival function estimator of the Cox model. We show that the bound holds even when the proportional hazards assumption does not hold.
Modeling analysis of ground water recharge potential on alluvial fans using limited data.
Munévar, A; Mariño, M A
1999-01-01
A modeling approach is developed to evaluate the potential for artificial recharge on alluvial fans in the Salinas Valley, California, using limited data of soil texture, soil hydraulic properties, and interwell stratigraphy. Promising areas for surface recharge are identified and mapped on a broad-scale using soil surveys, geologic investigations, permeability tests, and seasonal ground water response to rainfall and runoff. Two-dimensional representations of the vadose zone at selected sites are then constructed from drillers'logs and soil material types are estimated. Next, hydraulic properties are assigned to each soil material type by comparing them to laboratory-tested cores of similar soils taken from one site. Finally, water flow through the vadose zone is modeled in two dimensions at seven sites using a transient, finite-difference, variably saturated flow model. Average infiltration rates range from 0.84 to 1.54 cm/hr and recharge efficiency, the percentage of infiltrated water that reaches the water table, varies from 51% to 79%. Infiltration rates and recharge efficiency are found to be relatively insensitive to recharge basin ponding depth due to the thickness of the vadose zones modeled (31 to 84 m). The impact of artificial recharge on the Salinas Valley ground water basin is investigated by simulating the regional ground water response to surface spreading and streamflow augmentation with a recently calibrated, finite-element, ground water-surface water model for the basin. It was determined that a combined approach of surface recharge and streamflow augmentation significantly reduces the state of ground water overdraft and, to a lesser extent, reduces the rate of sea water intrusion.
Institute of Scientific and Technical Information of China (English)
周长锋
2013-01-01
Under bounded rationality evolutionary game analysis, the paper analyzes the dynamic genetic reproduction process for the players. It research that whether the insured purchases insurance depends on their comparison of the expected return and costs. The track of game between insurers and insurance applying didn't conform to the evolution stabilization strategy for both parties, but it could achieve a relatively better strategy in the insurance market.% 在有限理性进化博弈分析框架下，分析了保险市场中保险局中人群体复制动态变化过程。研究发现，投保人是否购买保险，一方面决定于其所要承担选择成本的大小，另一方面决定于个体的比较预期收益，而使博弈双方共同稳定的进化稳定策略不存在于保险人与投保人的博弈轨迹中，只能实现保险市场上平均意义上较优策略。
Soil-specific limitations for access and analysis of soil microbial communities by metagenomics.
Lombard, Nathalie; Prestat, Emmanuel; van Elsas, Jan Dirk; Simonet, Pascal
2011-10-01
Metagenomics approaches represent an important way to acquire information on the microbial communities present in complex environments like soil. However, to what extent do these approaches provide us with a true picture of soil microbial diversity? Soil is a challenging environment to work with. Its physicochemical properties affect microbial distributions inside the soil matrix, metagenome extraction and its subsequent analyses. To better understand the bias inherent to soil metagenome 'processing', we focus on soil physicochemical properties and their effects on the perceived bacterial distribution. In the light of this information, each step of soil metagenome processing is then discussed, with an emphasis on strategies for optimal soil sampling. Then, the interaction of cells and DNA with the soil matrix and the consequences for microbial DNA extraction are examined. Soil DNA extraction methods are compared and the veracity of the microbial profiles obtained is discussed. Finally, soil metagenomic sequence analysis and exploitation methods are reviewed.
International Nuclear Information System (INIS)
A design of a typical teletherapy facility was made considering a Co-60 rotating unit and using critical parameters, taking into account as a design base the dose limits established in the Safety Series No. 9 (1), and Safety Series No.115-I (2), shielding thickness when the dose limits were changed. An increment in the required thickness of 1,35 CHR for controlled areas and 2,37 CHR for non-controlled areas were found. This work considered the selection of four different types of teletherapy facilities using Co-60 sources, with different design and type of used unit. An analysis of thickness was made taking into account both the original values for the design and the real operation values in each facility. In order to determine the necessary changes for the wall thicknesses when the new recommendations are applied. (authors). 4 refs., 3 tabs
Monotonicity of the quantum linear programming bound
Eric M. Rains
1998-01-01
The most powerful technique known at present for bounding the size of quantum codes of prescribed minimum distance is the quantum linear programming bound. Unlike the classical linear programming bound, it is not immediately obvious that if the quantum linear programming constraints are satisfiable for dimension K, that the constraints can be satisfied for all lower dimensions. We show that the quantum linear programming bound is indeed monotonic in this sense, and give an explicitly monotoni...
Yaroshchuk, Andriy
2012-11-15
The problem is considered theoretically of dynamics of current-induced concentration polarization of interfaces between ideally perm-selective and non-ideally perm-selective ("leaky") ion-exchange media in binary electrolyte solutions under galvanostatic conditions and at negligible volume flow. In contrast to the previous studies, the analysis is systematically carried out in terms of local thermodynamic equilibrium in the approximation of local electric neutrality in virtual solution. For macroscopically homogeneous media, this enables one to obtain model-independent results in quadratures for the stationary state as well as an approximate scaling-form solution for the transient response to the step-wise increase in electric-current density. These results are formulated in terms of such phenomenological properties of the "leaky" medium as ion transport numbers, diffusion permeability to salt and specific chemical capacity. An easy-to-solve numerically 1D PDE is also formulated in the same terms. A systematic parametric study is carried out within the scope of fine-pore model of "leaky" medium in terms of such properties as volumetric concentration of fixed electric charges and diffusivities of ions of symmetrical electrolyte. While previous studies paid principal attention to the shape and propagation rate of the so-called deionization "shocks", we also consider in detail the time evolution of voltage drop and interface salt concentration. Our analysis confirms the previously predicted pattern of propagating deionization "shocks" within the "leaky" medium but also reveals several novel features. In particular, we demonstrate that the deionization-shock pattern is really pronounced only at intermediate ratios of fixed-charge concentration to the initial salt concentration and at quite high steady-state voltages where the model used in this and previous studies is applicable only at relatively early stages of concentration-polarization process. PMID:22947188
Directory of Open Access Journals (Sweden)
Carlos Antonio Fernandes Santos
2005-01-01
Full Text Available Two F2 carrot (Daucus carota L. populations (orange rooted Brasilia x very dark orange rooted High Carotene Mass - HCM cross and the dark orange rooted cultivated variety B493 x white rooted wild carrot Queen Anne's Lace - QAL cross with very unrelated genetic backgrounds were used to investigate intrinsic factors limiting carotenoid accumulation in carrots by applying phenotypic correlation and path analysis to study the relationships between major root carotenes, root color and several other morphological traits. Most of the correlations between traits were close and agreed in sign between the two populations. Root weight had a moderate to highly significant positive correlation with leaf length, root length and top and middle root diameter. Although phenotypic correlations failed to identify the order of the substrates and products in the carotenoid pathway the correct order of substrates and products (phytoene -> zeta-carotene -> lycopene was identified in the causal diagram of beta-carotene for the Brasilia x HCM population. Path analysis of beta-carotene synthesis in the B493 x QAL population suggested that selection for root carotenes had little effect on plant morphological traits. Causal model of beta-carotene and lycopene in the B493 x QAL population suggested that phytoene synthesis is the key step limiting the carotenoid pathway in white carrots. Path analysis, first presented by Sewall Wright to study quantitative traits, appears to be a powerful statistical approach for the identification of key compounds in complex pathways.
Bound entangled states invariant under Ux
Institute of Scientific and Technical Information of China (English)
Wang Zhen; Wang Zhi-Xi
2008-01-01
This paper obtains an entangled condition for isotropic-like states by using an atomic map. It constructs a class of bound entangled states from the entangled condition and shows that the partial transposition of the state from the constructed bound entangled class is an edge bound entangled state by using range criterion.
Bounded rationality and heterogeneous expectations in macroeconomics
D. Massaro
2012-01-01
This thesis studies the effect of individual bounded rationality on aggregate macroeconomic dynamics. Boundedly rational agents are specified as using simple heuristics in their decision making. An important aspect of the type of bounded rationality described in this thesis is that the population of
Upper Bounds on Numerical Approximation Errors
DEFF Research Database (Denmark)
Raahauge, Peter
2004-01-01
This paper suggests a method for determining rigorous upper bounds on approximationerrors of numerical solutions to infinite horizon dynamic programming models.Bounds are provided for approximations of the value function and the policyfunction as well as the derivatives of the value function...... to approximations of a standard (strictly concave)growth model.KEYWORDS: Numerical approximation errors, Bellman contractions, Error bounds...
Counting Young Tableaux of Bounded Height
Bergeron, Francois; Gascon, Francis
2000-03-01
We show that formulas of Gessel, for the generating functions for Young standard tableaux of height bounded by k (see [2]), satisfy linear differential equations, with polynomial coefficients, equivalent to P-recurrences conjectured by Favreau, Krob and the first author (see [1]) for the number of bounded height tableaux and pairs of bounded height tableaux.
Data-driven analysis of soil quality indicators using limited data
Pulido Moncada, Mansonia; Gabriels, Donald; Cornelis, Wim
2016-04-01
The difficult question of which variables to include as a minimum data set of soil quality (SQ) indicators may be simplified by statistical methods, which allow working with databases including categorical and numerical variables commonly used for assessing SQ. The aims of this study were: i) to identify soil structural related parameters that may associate to SQ at different geographic areas and ii) to test the potential power of using decision trees in setting up a framework for SQ assessment, and in determining structural soil properties, visually evaluated, that could be included in the estimation of soil physical properties such as saturated hydraulic conductivity (Ks). SQ was evaluated by visual soil assessment (VSA) in the field and a limited number of physical and chemical soil properties (bulk density (BD), air capacity, plant available water capacity (PAWC), saturated hydraulic conductivity (Ks), water stable aggregates (WSA), particle size distribution, soil organic carbon (SOC) and cation exchange capacity (CEC)) determined in the laboratory. Using categorical and numerical data of those physical, chemical and morphological properties of soils in both tropical and temperate areas, classification trees and model trees were grown. Parameters related to SQ differed between geographic areas. Ks was the strongest variable determining the SQ in 'tropical' soils, but WSA, SOC and PAWC were also key variables in determining differences in SQ. For 'temperate' soils PAWC was the only variable selected by the tree building algorithm. SOC, clay, and CEC were the discriminating variables of the model constructed from the combined data set. Statistically significant relationships between measured and visual parameters are promising in demonstrating the SQ description required for merging morphological, physical and chemical properties for minimum data set of SQ indicators. Thresholds of different predicting variables could be better established when SQ frameworks
Stellar Evolution Bounds on the ALP-Photon Coupling: new Results and Perspectives
Giannotti, Maurizio
2014-01-01
Stellar evolution considerations are of fundamental importance in our understanding of the axion/ALP-photon coupling, g_{a\\gamma}. Helium burning stars are the best laboratories to study this coupling. Here, we will review the bounds from massive and low mass helium burning stars, and present a new analysis of the bound from the horizontal branch stars. The analysis provides the strongest bound to date on g_{a\\gamma} in a wide mass range.
析萨托利“有限多数原则”%Analysis on Limited Majority Principle of Sartori
Institute of Scientific and Technical Information of China (English)
徐俊
2013-01-01
乔万尼萨托利在《民主新论》中强调，民主的工作原则是有限的（受限制的）多数统治原则，且这一原则立足于保护少数权利以及利用少数权利限制多数的统治。同时，有限多数原则是现代民主制度的可行性原则，该文通过对简单多数原则与有限多数原则的分析，阐明了简单多数原则的含义及其存在的问题。进而通过与简单多数原则比较，分析了有限多数原则及其所具有的优点，指出了在现代民主的运行过程中有限多数原则比简单多数原则更可行。%In the book of The Theory of Democracy Revisited, Giovanni Sartori stressed that the working principle of democracy is limited or restricted majority rule which is based on the protection of minority rights and the utilization of minority rights to limit the rule of the majority. Meanwhile, limited majority rule is the feasible principle of modern democracy. Through contrastive analysis of plurality rule and limited majority rule, this paper expounds the meaning of the former and its existing problems and further analyzes the advantages of the latter in comparison to the former, and it comes down to that limited majority principle is more feasible than plurality rule in the operating process of modern democracy.
Institute of Scientific and Technical Information of China (English)
Wim Verelst; Edoardo Bertolini; Stefanie De Bodt; Klaas Vandepoele; Marlies Demeulenaere; Mario Enrico Pè; Dirk Inzé
2013-01-01
The drought-tolerant grass Brachypodium distachyon is an emerging model species for temperate grasses and cereal crops.To explore the usefulness of this species for drought studies,a reproducible in vivo drought assay was developed.Spontaneous soil drying led to a 45％ reduction in leaf size,and this was mostly due to a decrease in cell expansion,whereas cell division remained largely unaffected by drought.To investigate the molecular basis of the observed leaf growth reduction,the third Brachypodium leaf was dissected in three zones,namely proliferation,expansion,and mature zones,and subjected to transcriptome analysis,based on a whole-genome tiling array.This approach allowed us to highlight that transcriptome profiles of different developmental leaf zones respond differently to drought.Several genes and functional processes involved in drought tolerance were identified.The transcriptome data suggest an increased energy availability in the proliferation zones,along with an up-regulation of sterol synthesis that may influence membrane fluidity.This information may be used to improve the tolerance of temperate cereals to drought,which is undoubtedly one of the major environmental challenges faced by agriculture today and in the near future.
Humbird, Kelli D
2016-01-01
Uncertainty quantification and sensitivity analyses are a vital component for predictive modeling in the sciences and engineering. The adjoint approach to sensitivity analysis requires solving a primary system of equations and a mathematically related set of adjoint equations. The information contained in the equations can be combined to produce sensitivity information in a computationally efficient manner. In this work, sensitivity analyses are performed on systems described by flux-limited radiative diffusion using the adjoint approach. The sensitivities computed are shown to agree with standard perturbation theory, and can be obtained in significantly less computational time.
Performance Analysis of a Power Limited Spectrum Sharing System with TAS/MRC
Khan, Fahd Ahmed
2014-02-01
Capacity of the cognitive radio network degrades due to the interference constraint from the primary network. The secondary network capacity can be enhanced in a cost effective way by means of spatial diversity, that can be achieved by adding multiple antennas on the secondary network terminals and performing antenna selection. In this paper, the performance of a multiple-input multiple-output (MIMO) secondary link with transmit antenna selection (TAS) at the transmitter and maximum ratio combining (MRC) at the receiver is analyzed. A peak transmit power constraint at the secondary transmitter is considered in addition to the interference power constraint and two scenarios are considered; 1) the MIMO cognitive system with TAS/MRC (MCS-TM) does not experience interference from the primary network (denote by MCS-TM-NI), and 2) MCS-TM does experience interference from the primary network (denote by MCS-TM-WI). The performance of both MCS-TM-NI and MCS-TM-WI is analyzed and, for a Rayleigh faded channel, closed-form expression for the outage probability is derived. In addition, closed-form expressions of the moment generating function, the symbol error rate and the ergodic capacity are obtained for the MCS-TM-NI. Asymptotic performance analysis of the MCS-TM-NI reveals that TAS/MRC in a MIMO cognitive system achieves a generalized diversity gain equal to the product of the number of transmit and receive antennas. Numerical results are also presented to corroborate the derived analytical results. © 1991-2012 IEEE.
Entropy bound for the photon gas in noncommutative spacetime
Nozari, K.; Gorji, M. A.; Damavandi Kamali, A.; Vakili, B.
2016-09-01
Motivated by the doubly special relativity theories and noncommutative spacetime structures, thermodynamical properties of the photon gas in a phase space with compact spatial momentum space is studied. At the high temperature limit, the upper bounds for the internal energy and entropy are obtained which are determined by the size of the compact spatial momentum space. The maximum internal energy turns out to be of the order of the Planck energy and the entropy bound is then determined by the factor (V /lPl3) through the relevant identification of the size of the momentum space with Planck scale. The entropy bound is very similar to the case of Bekenstein-Hawking entropy of black holes and suggests that thermodynamics of black holes may be deduced from a saturated state in the framework of a full quantum gravitational statistical mechanics.
Dark matter annihilation bound from the diffuse gamma ray flux
Energy Technology Data Exchange (ETDEWEB)
Kachelriess, M.; /Norwegian U. Sci. Tech.; Serpico, P.D.; /Fermilab
2007-07-01
An upper limit on the total annihilation rate of dark matter (DM) has been recently derived from the observed atmospheric neutrino background. It is a very conservative upper bound based on the sole hypothesis that the DM annihilation products are the least detectable final states in the Standard Model (SM), neutrinos. Any other decay channel into SM particles would lead to stronger constraints. We show that comparable bounds are obtained for DM masses around the TeV scale by observations of the diffuse gamma ray flux by EGRET, because electroweak bremsstrahlung leads to non-negligible electromagnetic branching ratios, even if DM particles only couple to neutrinos at tree level. A better mapping and the partial resolution of the diffuse gamma-ray background into astrophysical sources by the GLAST satellite will improve this bound in the near future.
Entropy bound for the photon gas in noncommutative spacetime
Nozari, K; Kamali, A Damavandi; Vakili, B
2015-01-01
Motivated by the doubly special relativity theories and noncommutative spacetime structures, thermodynamical properties of the photon gas in a phase space with compact spatial momentum space is studied. At the high temperature limit, the upper bounds for the internal energy and entropy are obtained which are determined by the size of the compact spatial momentum space. The maximum internal energy turns out to be of the order of the Planck energy and the entropy bound is then determined by the factor $\\big(V/l_{_{\\rm Pl}}^3\\big)$ through the relevant identification of the size of the momentum space with Planck scale. The entropy bound is very similar to the case of Bekenstein-Hawking entropy of black holes and suggests that thermodynamics of black holes may be deduced from a saturated state in the framework of a full quantum gravitational statistical mechanics.
Probing Majorana Bound States in T-Shaped Junctions
Wu, Bin-He; Cheng, Xiao; Wang, Chun-Rui; Gong, Wei-Jiang
2014-03-01
We investigate the transport properties of a pair of Majorana bound states in a T-shaped junction, where two normal leads are coupled with an identical Majorana bound state. Both the scattering matrix and the recursive Green function method show that the peak value of the differential conductance (Gpeak) in units of e2/h and the shot noise Fano factor in the zero bias limit (F0), which are measured at the same lead and zero temperature, satisfy a linear relation as F0 = 1 + Gpeak/2, independent of the magnitude or symmetry of the coupling strengths to the leads. Therefore, combined measurements of the differential conductance and shot noise in the T-shaped geometry can serve as a characteristic signature in probing Majorana bound states.
Chellaboina, VijaySekhar; Haddad, Wassim M.; Li, Hancao; Bailey, James M.
2010-05-01
Acute respiratory failure due to infection, trauma or major surgery is one of the most common problems encountered in intensive care units, and mechanical ventilation is the mainstay of supportive therapy for such patients. In this article, we develop a general mathematical model for the dynamic behaviour of a multi-compartment respiratory system in response to an arbitrary applied inspiratory pressure. Specifically, we use compartmental dynamical system theory and Poincaré maps to model and analyse the dynamics of a pressure-limited respirator and lung mechanics system, and show that the periodic orbit generated by this system is globally asymptotically stable. Furthermore, we show that the individual compartmental volumes, and hence the total lung volume, converge to steady-state end-inspiratory and end-expiratory values. Finally, we develop a model reference direct adaptive controller framework for the multi-compartmental model of a pressure-limited respirator and lung mechanics system where the plant and reference model involve switching and time-varying dynamics. We then apply the proposed adaptive feedback controller framework to stabilise a given limit cycle corresponding to a clinically plausible respiratory pattern.
Higgs mass bounds from the functional RG
International Nuclear Information System (INIS)
We investigate a Top-Yukawa toy model to study Higgs mass bounds in the framework of the functional renormalization group (RG). Starting the calculations with a quartic ultraviolet (UV) potential we get a finite range of values for the Higgs mass in the infrared for a given cutoff. The bounds appear in a natural way as a consequence of the RG flow. The lower mass bound is approached for a vanishing UV quartic coupling. Furthermore, we study the influence of higher-dimensional operators on the lower Higgs mass bound. We find that even seemingly RG irrelevant interactions can take a substantial influence on the lower bound for the Higgs mass.
Rico, Javier; Drlica-Wagner, Alex
2015-01-01
We present the first MAGIC/Fermi-LAT joint search for dark matter annihilation gamma-ray signals from dwarf satellite galaxies. We combine 158 hours of observations of Segue 1 by MAGIC with 6-years observations of 15 dwarf satellite galaxies by the Fermi-LAT. We obtain limits on the annihilation cross-section for dark matter particle masses between 10 GeV and 100 TeV - the widest mass range ever explored by a coherent and comprehensive analysis. Our new inclusive analysis approach is completely generic, and we propose to use it to perform a global, sensitivity-optimized dark matter search by combining data from present and future gamma-ray and neutrino detectors.
Nuclear-polarization correction to the bound-electron g factor in heavy hydrogenlike ions
Nefiodov, A. V.; Plunien, G.; Soff, G.
2002-01-01
The influence of nuclear polarization on the bound-electron $g$ factor in heavy hydrogenlike ions is investigated. Numerical calculations are performed for the K- and L-shell electrons taking into account the dominant virtual nuclear excitations. This determines the ultimate limit for tests of QED utilizing measurements of the bound-electron $g$ factor in highly charged ions.
Nuclear-polarization correction to the bound-electron g factor in heavy hydrogenlike ions.
Nefiodov, A V; Plunien, G; Soff, G
2002-08-19
The influence of nuclear polarization on the bound-electron g factor in heavy hydrogenlike ions is investigated. Numerical calculations are performed for the K- and L-shell electrons taking into account the dominant virtual nuclear excitations. This determines the ultimate limit for tests of QED utilizing measurements of the bound-electron g factor in highly charged ions.
Nuclear-polarization correction to the bound-electron g factor in heavy hydrogenlike ions.
Nefiodov, A V; Plunien, G; Soff, G
2002-08-19
The influence of nuclear polarization on the bound-electron g factor in heavy hydrogenlike ions is investigated. Numerical calculations are performed for the K- and L-shell electrons taking into account the dominant virtual nuclear excitations. This determines the ultimate limit for tests of QED utilizing measurements of the bound-electron g factor in highly charged ions. PMID:12190457