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Sample records for linear inequality constraints

  1. Exploring stochasticity and imprecise knowledge based on linear inequality constraints.

    PubMed

    Subbey, Sam; Planque, Benjamin; Lindstrøm, Ulf

    2016-09-01

    This paper explores the stochastic dynamics of a simple foodweb system using a network model that mimics interacting species in a biosystem. It is shown that the system can be described by a set of ordinary differential equations with real-valued uncertain parameters, which satisfy a set of linear inequality constraints. The constraints restrict the solution space to a bounded convex polytope. We present results from numerical experiments to show how the stochasticity and uncertainty characterizing the system can be captured by sampling the interior of the polytope with a prescribed probability rule, using the Hit-and-Run algorithm. The examples illustrate a parsimonious approach to modeling complex biosystems under vague knowledge. PMID:26746217

  2. Transient response of multidegree-of-freedom linear systems to forcing functions with inequality constraints

    NASA Technical Reports Server (NTRS)

    Michalopoulos, C. D.

    1974-01-01

    Optimal control theory is applied to analyze the transient response of discrete linear systems to forcing functions with unknown time dependence but having known bounds. Particular attention is given to forcing functions which include: (1) maximum displacement of any given mass element, (2) maximum relative displacement of any two adjacent masses, and (3) maximum acceleration of a given mass. Linear mechanical systems with an arbitrary number of degrees of freedom and only one forcing function acting are considered. In the general case, the desired forcing function is found to be a function that switches from the upper-to-lower bound and vice-versa at certain moments of time. A general procedure for finding such switching times is set forth.

  3. Response of discrete linear systems to forcing functions with inequality constraints.

    NASA Technical Reports Server (NTRS)

    Michalopoulos, C. D.; Riley, T. A.

    1972-01-01

    An analysis is made of the maximum response of discrete, linear mechanical systems to arbitrary forcing functions which lie within specified bounds. Primary attention is focused on the complete determination of the forcing function which will engender maximum displacement to any particular mass element of a multi-degree-of-freedom system. In general, the desired forcing function is found to be a bang-bang type function, i.e., a function which switches from the maximum to the minimum bound and vice-versa at certain instants of time. Examples of two-degree-of-freedom systems, with and without damping, are presented in detail. Conclusions are drawn concerning the effect of damping on the switching times and the general procedure for finding these times is discussed.

  4. Data assimilation with inequality constraints

    NASA Astrophysics Data System (ADS)

    Thacker, W. C.

    If values of variables in a numerical model are limited to specified ranges, these restrictions should be enforced when data are assimilated. The simplest option is to assimilate without regard for constraints and then to correct any violations without worrying about additional corrections implied by correlated errors. This paper addresses the incorporation of inequality constraints into the standard variational framework of optimal interpolation with emphasis on our limited knowledge of the underlying probability distributions. Simple examples involving only two or three variables are used to illustrate graphically how active constraints can be treated as error-free data when background errors obey a truncated multi-normal distribution. Using Lagrange multipliers, the formalism is expanded to encompass the active constraints. Two algorithms are presented, both relying on a solution ignoring the inequality constraints to discover violations to be enforced. While explicitly enforcing a subset can, via correlations, correct the others, pragmatism based on our poor knowledge of the underlying probability distributions suggests the expedient of enforcing them all explicitly to avoid the computationally expensive task of determining the minimum active set. If additional violations are encountered with these solutions, the process can be repeated. Simple examples are used to illustrate the algorithms and to examine the nature of the corrections implied by correlated errors.

  5. Kalman Filtering with Inequality Constraints for Turbofan Engine Health Estimation

    NASA Technical Reports Server (NTRS)

    Simon, Dan; Simon, Donald L.

    2003-01-01

    Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints (which may be based on physical considerations) are often neglected because they do not fit easily into the structure of the Kalman filter. This paper develops two analytic methods of incorporating state variable inequality constraints in the Kalman filter. The first method is a general technique of using hard constraints to enforce inequalities on the state variable estimates. The resultant filter is a combination of a standard Kalman filter and a quadratic programming problem. The second method uses soft constraints to estimate state variables that are known to vary slowly with time. (Soft constraints are constraints that are required to be approximately satisfied rather than exactly satisfied.) The incorporation of state variable constraints increases the computational effort of the filter but significantly improves its estimation accuracy. The improvement is proven theoretically and shown via simulation results. The use of the algorithm is demonstrated on a linearized simulation of a turbofan engine to estimate health parameters. The turbofan engine model contains 16 state variables, 12 measurements, and 8 component health parameters. It is shown that the new algorithms provide improved performance in this example over unconstrained Kalman filtering.

  6. On partial errors-in-variables models with inequality constraints of parameters and variables

    NASA Astrophysics Data System (ADS)

    Zeng, Wenxian; Liu, Jingnan; Yao, Yibin

    2015-02-01

    Recent studies have extensively discussed total least squares (TLS) algorithms for solving the errors-in-variables (EIV) model with equality constraints but rarely investigated the inequality-constrained EIV model. The most existing inequality-constrained TLS algorithms assume that all the elements in the coefficient matrix are random and independent and that their numerical efficiency is significantly limited due to combinatorial difficulty. To solve the above issues, we formulate a partial EIV model with inequality constraints of both unknown parameters and the random elements of the coefficient matrix. Based on the formulated EIV model, the inequality-constrained TLS problem is transformed into a linear complementarity problem through linearization. In this way, the inequality-constrained TLS method remains applicable even when the elements of the coefficient matrix are subject to inequality constraints. Furthermore, the precision of the constrained estimates is put forward from a frequentist point of view. Three numerical examples are presented to demonstrate the efficiency and superiority of the proposed algorithm. The application is accomplished by preserving the structure of random coefficient matrix and satisfying the constraints simultaneously, without any combinatorial difficulty.

  7. CT metal artifact reduction by soft inequality constraints

    NASA Astrophysics Data System (ADS)

    Chukalina, Marina; Nikolaev, Dmitry; Sokolov, Valerii; Ingacheva, Anastasiya; Buzmakov, Alexey; Prun, Victor

    2015-12-01

    The artifacts (known as metal-like artifacts) arising from incorrect reconstruction may obscure or simulate pathology in medical applications, hide or mimic cracks and cavities in the scanned objects in industrial tomographic scans. One of the main reasons caused such artifacts is photon starvation on the rays which go through highly absorbing regions. We indroduce a way to suppress such artifacts in the reconstructions using soft penalty mimicing linear inequalities on the photon starved rays. An efficient algorithm to use such information is provided and the effect of those inequalities on the reconstruction quality is studied.

  8. Consistency and inconsistency radii for solving systems of linear equations and inequalities

    NASA Astrophysics Data System (ADS)

    Murav'eva, O. V.

    2015-03-01

    Problems that reduce to consistency or inconsistency of systems of linear equations or inequalities arise in many divisions of theoretical informatics. The examples are problems in linear programming, machine learning, multicriteria optimization, etc. There exist different stability measures for the property of consistency or inconsistency, and different information constituents are possible (all the input parameters, the coefficient matrix, the vector of constraints). In this paper, variations of all parameters are examined in combination with an additional constraint important in applications, namely, the nonnegativity of feasible points.

  9. Motorcycle suspension design using matrix inequalities and passivity constraints

    NASA Astrophysics Data System (ADS)

    Sharma, Amrit; Limebeer, David J. N.

    2012-03-01

    This paper presents a design methodology for the suspension system of a novel aerodynamically efficient motorcycle. Since the machine's layout and the rider's seating position are unconventional, several aspects of the machine design, including the suspension, must be reviewed afresh. The design process is based on matrix inequalities that are used to optimise a road-grip objective function - others could be used equally well. The design problem is cast as the minimisation of an H 2 cost with passivity constraints imposed on the suspension transference. The resulting bilinear matrix inequality problem is solved using a locally optimal iterative algorithm. The matrix inequality-type characterisation of positive real functions permits the optimisation of the suspension system over an entire class of passive admittances. Torsional springs, dampers and inerters are then used to construct networks corresponding to the optimal (positive real) admittances. Networks of first, second, third and fourth orders are considered, and an argument based on the compromise between complexity and improved grip is made for the most suitable suspension configuration. Finally, the effects of improved road grip on the stability of the vehicle's lateral dynamics are analysed.

  10. Finite element solution of optimal control problems with inequality constraints

    NASA Technical Reports Server (NTRS)

    Bless, Robert R.; Hodges, Dewey H.

    1990-01-01

    A finite-element method based on a weak Hamiltonian form of the necessary conditions is summarized for optimal control problems. Very crude shape functions (so simple that element numerical quadrature is not necessary) can be used to develop an efficient procedure for obtaining candidate solutions (i.e., those which satisfy all the necessary conditions) even for highly nonlinear problems. An extension of the formulation allowing for discontinuities in the states and derivatives of the states is given. A theory that includes control inequality constraints is fully developed. An advanced launch vehicle (ALV) model is presented. The model involves staging and control constraints, thus demonstrating the full power of the weak formulation to date. Numerical results are presented along with total elapsed computer time required to obtain the results. The speed and accuracy in obtaining the results make this method a strong candidate for a real-time guidance algorithm.

  11. On the development of HSCT tail sizing criteria using linear matrix inequalities

    NASA Technical Reports Server (NTRS)

    Kaminer, Isaac

    1995-01-01

    This report presents the results of a study to extend existing high speed civil transport (HSCT) tail sizing criteria using linear matrix inequalities (LMI). In particular, the effects of feedback specifications, such as MIL STD 1797 Level 1 and 2 flying qualities requirements, and actuator amplitude and rate constraints on the maximum allowable cg travel for a given set of tail sizes are considered. Results comparing previously developed industry criteria and the LMI methodology on an HSCT concept airplane are presented.

  12. Effects of Classroom Instruction on Student Performance on, and Understanding of, Linear Equations and Linear Inequalities

    ERIC Educational Resources Information Center

    Vaiyavutjamai, Pongchawee; Clements, M. A.

    2006-01-01

    Two-hundred and thirty-one students in 6 Grade 9 classes in 2 secondary schools in Thailand attempted 54 pencil-and-paper tasks related to linear equations and linear inequalities immediately before and after they participated in 13 lessons on those topics. Students' written responses, and transcripts of pre- and postteaching interviews with 18…

  13. On non-combinatorial weighted total least squares with inequality constraints

    NASA Astrophysics Data System (ADS)

    Fang, Xing

    2014-08-01

    Observation systems known as errors-in-variables (EIV) models with model parameters estimated by total least squares (TLS) have been discussed for more than a century, though the terms EIV and TLS were coined much more recently. So far, it has only been shown that the inequality-constrained TLS (ICTLS) solution can be obtained by the combinatorial methods, assuming that the weight matrices of observations involved in the data vector and the data matrix are identity matrices. Although the previous works test all combinations of active sets or solution schemes in a clear way, some aspects have received little or no attention such as admissible weights, solution characteristics and numerical efficiency. Therefore, the aim of this study was to adjust the EIV model, subject to linear inequality constraints. In particular, (1) This work deals with a symmetrical positive-definite cofactor matrix that could otherwise be quite arbitrary. It also considers cross-correlations between cofactor matrices for the random coefficient matrix and the random observation vector. (2) From a theoretical perspective, we present first-order Karush-Kuhn-Tucker (KKT) necessary conditions and the second-order sufficient conditions of the inequality-constrained weighted TLS (ICWTLS) solution by analytical formulation. (3) From a numerical perspective, an active set method without combinatorial tests as well as a method based on sequential quadratic programming (SQP) is established. By way of applications, computational costs of the proposed algorithms are shown to be significantly lower than the currently existing ICTLS methods. It is also shown that the proposed methods can treat the ICWTLS problem in the case of more general weight matrices. Finally, we study the ICWTLS solution in terms of non-convex weighted TLS contours from a geometrical perspective.

  14. Solving linear inequalities in a least squares sense

    SciTech Connect

    Bramley, R.; Winnicka, B.

    1994-12-31

    Let A {element_of} {Re}{sup mxn} be an arbitrary real matrix, and let b {element_of} {Re}{sup m} a given vector. A familiar problem in computational linear algebra is to solve the system Ax = b in a least squares sense; that is, to find an x* minimizing {parallel}Ax {minus} b{parallel}, where {parallel} {center_dot} {parallel} refers to the vector two-norm. Such an x* solves the normal equations A{sup T}(Ax {minus} b) = 0, and the optimal residual r* = b {minus} Ax* is unique (although x* need not be). The least squares problem is usually interpreted as corresponding to multiple observations, represented by the rows of A and b, on a vector of data x. The observations may be inconsistent, and in this case a solution is sought that minimizes the norm of the residuals. A less familiar problem to numerical linear algebraists is the solution of systems of linear inequalities Ax {le} b in a least squares sense, but the motivation is similar: if a set of observations places upper or lower bounds on linear combinations of variables, the authors want to find x* minimizing {parallel} (Ax {minus} b){sub +} {parallel}, where the i{sup th} component of the vector v{sub +} is the maximum of zero and the i{sup th} component of v.

  15. Linear matrix inequality-based proportional-integral control design with application to F-16 aircraft

    NASA Astrophysics Data System (ADS)

    Theodore, Zachary B.

    A robust proportional-integral (PI) controller was synthesized for the F-16 VISTA (Variable stability In-flight Simulator Test Aircraft) using a linear matrix inequality (LMI) approach, with the goal of eventually designing and implementing a linear parameter-varying PI controller on high performance aircraft. The combination of classical and modern control theory provides theoretically guaranteed stability and performance throughout the flight envelope and ease of implementation due to the simplicity of the PI controller structure. The controller is designed by solving a set of LMIs with pole placement constraints. This closed-loop system was simulated in MATLAB/Simulink to analyze the performance of the controller. A robust Hinfinity controller was also developed to compare performance with PI controller. The simulation results showed stability, albeit with poor performance compared to the Hinfinity controlle.

  16. Review of LFTs, LMIs, and mu. [Linear Fractional Transformations, Linear Matrix Inequalities

    NASA Technical Reports Server (NTRS)

    Doyle, John; Packard, Andy; Zhou, Kemin

    1991-01-01

    The authors present a tutorial overview of linear fractional transformations (LFTs) and the role of the structured singular value, mu, and linear matrix inequalities (LMIs) in solving LFT problems. The authors first introduce the notation for LFTs and briefly discuss some of their properties. They then describe mu and its connections with LFTs. They focus on two standard notions of robust stability and performance, mu stability and performance and Q stability and performance, and their relationship is discussed. Comparisons with the L1 theory of robust performance with structured uncertainty are considered.

  17. Optimal control of singularly perturbed nonlinear systems with state-variable inequality constraints

    NASA Technical Reports Server (NTRS)

    Calise, A. J.; Corban, J. E.

    1990-01-01

    The established necessary conditions for optimality in nonlinear control problems that involve state-variable inequality constraints are applied to a class of singularly perturbed systems. The distinguishing feature of this class of two-time-scale systems is a transformation of the state-variable inequality constraint, present in the full order problem, to a constraint involving states and controls in the reduced problem. It is shown that, when a state constraint is active in the reduced problem, the boundary layer problem can be of finite time in the stretched time variable. Thus, the usual requirement for asymptotic stability of the boundary layer system is not applicable, and cannot be used to construct approximate boundary layer solutions. Several alternative solution methods are explored and illustrated with simple examples.

  18. Optimization technique for problems with an inequality constraint

    NASA Technical Reports Server (NTRS)

    Russell, K. J.

    1972-01-01

    General technique uses a modified version of an existing technique termed the pattern search technique. New procedure called the parallel move strategy permits pattern search technique to be used with problems involving a constraint.

  19. Optimal control problems with mixed control-phase variable equality and inequality constraints

    NASA Technical Reports Server (NTRS)

    Makowski, K.; Neustad, L. W.

    1974-01-01

    In this paper, necessary conditions are obtained for optimal control problems containing equality constraints defined in terms of functions of the control and phase variables. The control system is assumed to be characterized by an ordinary differential equation, and more conventional constraints, including phase inequality constraints, are also assumed to be present. Because the first-mentioned equality constraint must be satisfied for all t (the independent variable of the differential equation) belonging to an arbitrary (prescribed) measurable set, this problem gives rise to infinite-dimensional equality constraints. To obtain the necessary conditions, which are in the form of a maximum principle, an implicit-function-type theorem in Banach spaces is derived.

  20. Finite element solution of optimal control problems with state-control inequality constraints

    NASA Technical Reports Server (NTRS)

    Bless, Robert R.; Hodges, Dewey H.

    1992-01-01

    It is demonstrated that the weak Hamiltonian finite-element formulation is amenable to the solution of optimal control problems with inequality constraints which are functions of both state and control variables. Difficult problems can be treated on account of the ease with which algebraic equations can be generated before having to specify the problem. These equations yield very accurate solutions. Owing to the sparse structure of the resulting Jacobian, computer solutions can be obtained quickly when the sparsity is exploited.

  1. Near-optimal, asymptotic tracking in control problems involving state-variable inequality constraints

    NASA Technical Reports Server (NTRS)

    Markopoulos, N.; Calise, A. J.

    1993-01-01

    The class of all piecewise time-continuous controllers tracking a given hypersurface in the state space of a dynamical system can be split by the present transformation technique into two disjoint classes; while the first of these contains all controllers which track the hypersurface in finite time, the second contains all controllers that track the hypersurface asymptotically. On this basis, a reformulation is presented for optimal control problems involving state-variable inequality constraints. If the state constraint is regarded as 'soft', there may exist controllers which are asymptotic, two-sided, and able to yield the optimal value of the performance index.

  2. An Improved Algorithm for Linear Inequalities in Pattern Recognition and Switching Theory.

    ERIC Educational Resources Information Center

    Geary, Leo C.

    This thesis presents a new iterative algorithm for solving an n by l solution vector w, if one exists, to a set of linear inequalities, A w greater than zero which arises in pattern recognition and switching theory. The algorithm is an extension of the Ho-Kashyap algorithm, utilizing the gradient descent procedure to minimize a criterion function…

  3. New classes of Lorenz curves by maximizing Tsallis entropy under mean and Gini equality and inequality constraints

    NASA Astrophysics Data System (ADS)

    Preda, Vasile; Dedu, Silvia; Gheorghe, Carmen

    2015-10-01

    In this paper, by using the entropy maximization principle with Tsallis entropy, new distribution families for modeling the income distribution are derived. Also, new classes of Lorenz curves are obtained by applying the entropy maximization principle with Tsallis entropy, under mean and Gini index equality and inequality constraints.

  4. First class models from linear and nonlinear second class constraints

    NASA Astrophysics Data System (ADS)

    Dehghani, Mehdi; Mardaani, Maryam; Monemzadeh, Majid; Nejad, Salman Abarghouei

    2015-10-01

    Two models with linear and nonlinear second class constraints are considered and gauged by embedding in an extended phase space. These models are studied by considering a free non-relativistic particle on the hyperplane and hypersphere in the configuration space. The gauged theory of the first model is obtained by converting the very second class system to the first class one directly. In contrast, the first class system related to the free particle on the hypersphere is derived with the help of the infinite Batalin-Fradkin-Tyutin (BFT) embedding procedure. We propose a practical formula, based on the simplified BFT method, which is practical in gauging linear and some nonlinear second class systems. As a result of gauging these two models, we show that in the conversion of second class constraints to the first class ones, the minimum number of phase space degrees of freedom for both systems is a pair of phase space coordinates. This pair is made up of a coordinate and its conjugate momentum for the first model, but the corresponding Poisson structure of the embedded non-relativistic particle on hypersphere is a nontrivial one. We derive infinite correction terms for the Hamiltonian of the nonlinear constraints and an interacting gauged Hamiltonian is constructed by summing over them. At the end, we find an open algebra for three first class objects of the embedded nonlinear system.

  5. Linear perturbation constraints on multi-coupled dark energy

    SciTech Connect

    Piloyan, Arpine; Marra, Valerio; Amendola, Luca; Baldi, Marco E-mail: valerio.marra@me.com E-mail: l.amendola@thphys.uni-heidelberg.de

    2014-02-01

    The Multi-coupled Dark Energy (McDE) scenario has been recently proposed as a specific example of a cosmological model characterized by a non-standard physics of the dark sector of the universe that nevertheless gives an expansion history which does not significantly differ from the one of the standard ΛCDM model. Thanks to a dynamical screening mechanism, in fact, the interaction between the Dark Energy field and the Dark Matter sector is effectively suppressed at the background level during matter domination. As a consequence, background observables cannot discriminate a McDE cosmology from ΛCDM for a wide range of model parameters. On the other hand, linear perturbations are expected to provide tighter bounds due to the existence of attractive and repulsive fifth-forces associated with the dark interactions. In this work, we present the first constraints on the McDE scenario obtained by comparing the predicted evolution of linear density perturbations with a large compilation of recent data sets for the growth rate fσ{sub 8}, including 6dFGS, LRG, BOSS, WiggleZ and VIPERS. Confirming qualitative expectations, growth rate data provide much tighter bounds on the model parameters as compared to the extremely loose bounds that can be obtained when only the background expansion history is considered. In particular, the 95% confidence level on the coupling strength |β| is reduced from |β| ≤ 83 (background constraints only) to |β| ≤ 0.88 (background and linear perturbation constraints). We also investigate how these constraints further improve when using data from future wide-field surveys such as supernova data from LSST and growth rate data from Euclid-type missions. In this case the 95% confidence level on the coupling further reduce to |β| ≤ 0.85. Such constraints are in any case still consistent with a scalar fifth-force of gravitational strength, and we foresee that tighter bounds might be possibly obtained from the investigation of nonlinear

  6. Linear perturbation constraints on multi-coupled dark energy

    NASA Astrophysics Data System (ADS)

    Piloyan, Arpine; Marra, Valerio; Baldi, Marco; Amendola, Luca

    2014-02-01

    The Multi-coupled Dark Energy (McDE) scenario has been recently proposed as a specific example of a cosmological model characterized by a non-standard physics of the dark sector of the universe that nevertheless gives an expansion history which does not significantly differ from the one of the standard ΛCDM model. Thanks to a dynamical screening mechanism, in fact, the interaction between the Dark Energy field and the Dark Matter sector is effectively suppressed at the background level during matter domination. As a consequence, background observables cannot discriminate a McDE cosmology from ΛCDM for a wide range of model parameters. On the other hand, linear perturbations are expected to provide tighter bounds due to the existence of attractive and repulsive fifth-forces associated with the dark interactions. In this work, we present the first constraints on the McDE scenario obtained by comparing the predicted evolution of linear density perturbations with a large compilation of recent data sets for the growth rate fσ8, including 6dFGS, LRG, BOSS, WiggleZ and VIPERS. Confirming qualitative expectations, growth rate data provide much tighter bounds on the model parameters as compared to the extremely loose bounds that can be obtained when only the background expansion history is considered. In particular, the 95% confidence level on the coupling strength |β| is reduced from |β| <= 83 (background constraints only) to |β| <= 0.88 (background and linear perturbation constraints). We also investigate how these constraints further improve when using data from future wide-field surveys such as supernova data from LSST and growth rate data from Euclid-type missions. In this case the 95% confidence level on the coupling further reduce to |β| <= 0.85. Such constraints are in any case still consistent with a scalar fifth-force of gravitational strength, and we foresee that tighter bounds might be possibly obtained from the investigation of nonlinear structure

  7. State control of discrete-time linear systems to be bound in state variables by equality constraints

    NASA Astrophysics Data System (ADS)

    Filasová, Anna; Krokavec, Dušan; Serbák, Vladimír

    2014-12-01

    The paper is concerned with the problem of designing the discrete-time equivalent PI controller to control the discrete-time linear systems in such a way that the closed-loop state variables satisfy the prescribed equality constraints. Since the problem is generally singular, using standard form of the Lyapunov function and a symmetric positive definite slack matrix, the design conditions are proposed in the form of the enhanced Lyapunov inequality. The results, offering the conditions of the control existence and the optimal performance with respect to the prescribed equality constraints for square discrete-time linear systems, are illustrated with the numerical example to note effectiveness and applicability of the considered approach.

  8. Interactive Analysis of Hyperspectral Data under Linearity Constraints

    NASA Astrophysics Data System (ADS)

    Schmidt, A.; Treguier, E.; Schmidt, F.; Moussaoui, S.; Pelloquin, C.

    2010-12-01

    Large data sets delivered by imaging spectrometers are interesting in many ways in the Planetary Sciences. Due to the size of the data and lack of ground truth, which often prohibit conventional exploratory data analysis methods, interactive but unsupervised analysis methods could be a way of discovering relevant information about the sources that make up the data. In this work, we investigate some of the opportunities and limitations of such analyses based on non-negative matrix approximation in planetary settings. Since typically there often is no ground truth to compare to, the degrees of freedom inherent in the aforementioned approximation techniques often has to be constrained by users to discover physically valid sources and patterns. One way of going about this is to present users with different valid solutions have them choose the one or ones that fit their knowledge of the environment best. Recent developments have made it possible to exploit linear mixing constraints and present results to users in real or near-real time; thus, the approach has become practicable. The general setting of the problem is as follows: By considering P pixels of an hyperspectral image acquired at L frequency bands, the observed spectra are gathered in a PxL data matrix X. Each row of this matrix contains a measured spectrum at a pixel with spatial index p=1..P. According to the linear mixing model, the p-th spectrum, 1<=p<=P, can be expressed as a linear combination of r, 1<=r<=R, pure spectra of the surface components. Thus, X=AxS+E, E being an error matrix, should be minimised, where X, A, and S have only non-negative entries. The rows of matrix S now contain the pure surface spectra of the R components, and each entry of A corresponds to the abundance of the r-th component in pixel with spatial index p. For a qualitative and quantitative description of the observed scene composition, the estimation problem consists of finding matrices S and A which allow to explain the data

  9. Linear constraint minimum variance beamformer functional magnetic resonance inverse imaging

    PubMed Central

    Lin, Fa-Hsuan; Witzel, Thomas; Zeffiro, Thomas A.; Belliveau, John W.

    2011-01-01

    Accurate estimation of the timing of neural activity is required to fully model the information flow among functionally specialized regions whose joint activity underlies perception, cognition and action. Attempts to detect the fine temporal structure of task-related activity would benefit from functional imaging methods allowing higher sampling rates. Spatial filtering techniques have been used in magnetoencephalography source imaging applications. In this work, we use the linear constraint minimal variance (LCMV) beamformer localization method to reconstruct single-shot volumetric functional magnetic resonance imaging (fMRI) data using signals acquired simultaneously from all channels of a high density radio-frequency (RF) coil array. The LCMV beamformer method generalizes the existing volumetric magnetic resonance inverse imaging (InI) technique, achieving higher detection sensitivity while maintaining whole-brain spatial coverage and 100 ms temporal resolution. In this paper, we begin by introducing the LCMV reconstruction formulation and then quantitatively assess its performance using both simulated and empirical data. To demonstrate the sensitivity and inter-subject reliability of volumetric LCMV InI, we employ an event-related design to probe the spatial and temporal properties of task-related hemodynamic signal modulations in primary visual cortex. Compared to minimum-norm estimate (MNE) reconstructions, LCMV offers better localization accuracy and superior detection sensitivity. Robust results from both single subject and group analyses demonstrate the excellent sensitivity and specificity of volumetric InI in detecting the spatial and temporal structure of task-related brain activity. PMID:18672071

  10. Multi-rate optimal controller design for electromagnetic suspension systems via linear matrix inequality optimization

    NASA Astrophysics Data System (ADS)

    Kim, C. H.; Park, H. J.; Lee, J.; Lee, H. W.; Lee, K. D.

    2015-05-01

    This paper develops a discrete optimal control based on the multi-rate observer method for electromagnetic suspension systems in order to levitate the vehicle, maintaining the desired gap. The proposed multi-rate compensator consists of two parts which are the discrete Kalman filter and the optimal control law. The Kalman filter estimates all states with fast sampling rate time, using a slowly measured output from the gap sensor. The optimal control law is determined by linear matrix inequality optimization for the discrete time multiple input system obtained by the lifting operator. The proposed multi-rate controller has the advantages to guarantee the stability of the slow-rate optimal control and maintain the performance of fast-rate control. The simulation and experiment show the effectiveness of the proposed control method.

  11. Construction of Lyapunov Function for Power System based on Solving Linear Matrix Inequality

    NASA Astrophysics Data System (ADS)

    Ishigame, Atsushi; Sakaguchi, Hiromu; Takashima, Jun; Suzaki, Shirou

    This paper presents a constructing Lyapunov function for power system based on solving the Linear Matrix Inequality (LMI) derived from the Lyapunov stability theorem considering with dynamics of load characteristic and AVR control system. The proposed Lyapunov function is constructed as a quadratic form of state variables and an integral term which satisfies the curl equation and the sector condition. An induction machine and a synchronous machine are considered as load characteristics. One machine and one load infinite bus system is considered taking into account the flux decay effects and AVR with one time constant of the generator. To verify the proposed Lyapunov function, the transient stability assessment is shown. The critical clearing times given by the proposed Lyapunov function are compared with those obtained by the numerical integration method, and they are shown to be practical.

  12. Fluid pressure arrival time tomography: Estimation and assessment in the presence of inequality constraints, with an application to a producing gas field at Krechba, Algeria

    SciTech Connect

    Rucci, A.; Vasco, D.W.; Novali, F.

    2010-04-01

    Deformation in the overburden proves useful in deducing spatial and temporal changes in the volume of a producing reservoir. Based upon these changes we estimate diffusive travel times associated with the transient flow due to production, and then, as the solution of a linear inverse problem, the effective permeability of the reservoir. An advantage an approach based upon travel times, as opposed to one based upon the amplitude of surface deformation, is that it is much less sensitive to the exact geomechanical properties of the reservoir and overburden. Inequalities constrain the inversion, under the assumption that the fluid production only results in pore volume decreases within the reservoir. We apply the formulation to satellite-based estimates of deformation in the material overlying a thin gas production zone at the Krechba field in Algeria. The peak displacement after three years of gas production is approximately 0.5 cm, overlying the eastern margin of the anticlinal structure defining the gas field. Using data from 15 irregularly-spaced images of range change, we calculate the diffusive travel times associated with the startup of a gas production well. The inequality constraints are incorporated into the estimates of model parameter resolution and covariance, improving the resolution by roughly 30 to 40%.

  13. Gendered Inequity in Society and the Academy: Policy Initiatives, Economic Realities and Legal Constraints

    ERIC Educational Resources Information Center

    Waldron-Moore, Pamela; Jacobs, Leslie R.

    2010-01-01

    Of all the social constructs impacting the contemporary world, gender is perhaps the most pervasive and the most insidious. Its inequities creep into our everyday lives with impunity. Across the globe, gender construction has evoked challenge, undergone reform and, in some instances, transformed thinking in societies. Yet, for all the gains made…

  14. An Evaluation of an Algorithm for Linear Inequalities and Its Applications

    NASA Technical Reports Server (NTRS)

    Jurgensen, J.

    1973-01-01

    An algorithm is presented for obtaining a solution alpha to a set of inequalities (A alpha) 0 where A is an N x m-matrix and alpha is an m-vector. If the set of inequalities is consistant, then the algorithm is guaranteed to arrive at a solution in a finite number of steps. Also, if in the iteration, a negative vector is obtained, then the initial set of inequalities is inconsistant, and the iteration is terminated.

  15. On the existence of touch points for first-order state inequality constraints

    NASA Technical Reports Server (NTRS)

    Seywald, Hans; Cliff, Eugene M.

    1993-01-01

    The appearance of touch points in state constrained optimal control problems with general vector-valued control is studied. Under the assumption that the Hamiltonian is regular, touch points for first-order state inequalities are shown to exist only under very special conditions. In many cases of practical importance these conditions can be used to exclude touch points a priori without solving an optimal control problem. The results are demonstrated on a simple example.

  16. Pre-Service Teachers' Linear and Quadratic Inequalities Understandings

    ERIC Educational Resources Information Center

    Bicer, Ali; Capraro, Robert M.; Capraro, Mary M.

    2014-01-01

    The National Council of Teachers of Mathematics [NCTM] noted that middle and high school students are expected to be able to both explain inequalities by using mathematical symbols and understand meanings by interpreting the solutions of inequalities. Unfortunately, research has revealed that not only do middle and high school students hold…

  17. Superlinear convergence of an interior-point method for monotone variational inequalities

    SciTech Connect

    Ralph, D.; Wright, S.

    1996-01-03

    We describe an infeasible-interior-point algorithm for monotone variational inequality problems and prove that it converges globally and superlinearly under standard conditions plus a constant rank constraint qualification. The latter condition represents a generalization of the two types of assumptions made in existing superlinear analyses; namely, linearity of the constraints and linear independence of the active constraint gradients.

  18. Nonlinear optimization with linear constraints using a projection method

    NASA Technical Reports Server (NTRS)

    Fox, T.

    1982-01-01

    Nonlinear optimization problems that are encountered in science and industry are examined. A method of projecting the gradient vector onto a set of linear contraints is developed, and a program that uses this method is presented. The algorithm that generates this projection matrix is based on the Gram-Schmidt method and overcomes some of the objections to the Rosen projection method.

  19. Linear matrix inequality-based nonlinear adaptive robust control with application to unmanned aircraft systems

    NASA Astrophysics Data System (ADS)

    Kun, David William

    Unmanned aircraft systems (UASs) are gaining popularity in civil and commercial applications as their lightweight on-board computers become more powerful and affordable, their power storage devices improve, and the Federal Aviation Administration addresses the legal and safety concerns of integrating UASs in the national airspace. Consequently, many researchers are pursuing novel methods to control UASs in order to improve their capabilities, dependability, and safety assurance. The nonlinear control approach is a common choice as it offers several benefits for these highly nonlinear aerospace systems (e.g., the quadrotor). First, the controller design is physically intuitive and is derived from well known dynamic equations. Second, the final control law is valid in a larger region of operation, including far from the equilibrium states. And third, the procedure is largely methodical, requiring less expertise with gain tuning, which can be arduous for a novice engineer. Considering these facts, this thesis proposes a nonlinear controller design method that combines the advantages of adaptive robust control (ARC) with the powerful design tools of linear matrix inequalities (LMI). The ARC-LMI controller is designed with a discontinuous projection-based adaptation law, and guarantees a prescribed transient and steady state tracking performance for uncertain systems in the presence of matched disturbances. The norm of the tracking error is bounded by a known function that depends on the controller design parameters in a known form. Furthermore, the LMI-based part of the controller ensures the stability of the system while overcoming polytopic uncertainties, and minimizes the control effort. This can reduce the number of parameters that require adaptation, and helps to avoid control input saturation. These desirable characteristics make the ARC-LMI control algorithm well suited for the quadrotor UAS, which may have unknown parameters and may encounter external

  20. Errors Analysis of Solving Linear Inequalities among the Preparatory Year Students at King Saud University

    ERIC Educational Resources Information Center

    El-khateeb, Mahmoud M. A.

    2016-01-01

    The purpose of this study aims to investigate the errors classes occurred by the Preparatory year students at King Saud University, through analysis student responses to the items of the study test, and to identify the varieties of the common errors and ratios of common errors that occurred in solving inequalities. In the collection of the data,…

  1. On Implicit Active Constraints in Linear Semi-Infinite Programs with Unbounded Coefficients

    SciTech Connect

    Goberna, M. A.; Lancho, G. A.; Todorov, M. I.; Vera de Serio, V. N.

    2011-04-15

    The concept of implicit active constraints at a given point provides useful local information about the solution set of linear semi-infinite systems and about the optimal set in linear semi-infinite programming provided the set of gradient vectors of the constraints is bounded, commonly under the additional assumption that there exists some strong Slater point. This paper shows that the mentioned global boundedness condition can be replaced by a weaker local condition (LUB) based on locally active constraints (active in a ball of small radius whose center is some nominal point), providing geometric information about the solution set and Karush-Kuhn-Tucker type conditions for the optimal solution to be strongly unique. The maintaining of the latter property under sufficiently small perturbations of all the data is also analyzed, giving a characterization of its stability with respect to these perturbations in terms of the strong Slater condition, the so-called Extended-Nuernberger condition, and the LUB condition.

  2. Constraints to universal coverage: inequities in health service use and expenditures for different health conditions and providers

    PubMed Central

    2011-01-01

    Background There is need for new information about the socio-economic and geographic differences in health seeking and expenditures on many health conditions, so to help to design interventions that will reduce inequity in utilisation of healthcare services and ensure universal coverage. Objectives The paper contributes additional knowledge about health seeking and economic burden of different health conditions. It also shows the level of healthcare payments in public and private sector and their distribution across socioeconomic and geographic population groups. Methods A questionnaire was used to collect data from randomly selected householders from 4,873 households (2,483 urban and 2,390 rural) in southeast Nigeria. Data was collected on: health problems that people had and sought care for; type of care sought, outpatient department (OPD) visits and inpatient department (IPD) stays; providers visited; expenditures; and preferences for improving access to care. Data was disaggregated by socio-economic status (SES) and geographic location (urban versus rural) of the households. Results Malaria and hypertension were the major communicable and non-communicable diseases respectively that required OPD and IPD. Patent medicine dealers (PMDs) were the most commonly used providers (41.1%), followed by private hospitals (19.7%) and pharmacies (16.4%). The rural dwellers and poorer SES groups mostly used low-level and informal providers. The average monthly treatment expenditure in urban area was 2444 Naira (US$20.4) and 2267 Naira (US$18.9) in the rural area. Higher SES groups and urbanites incurred higher health expenditures. People that needed healthcare services did not seek care mostly because the health condition was not serious enough or they could not afford the cost of services. Conclusion There were inequities in use of the different providers, and also in expenditures on treatment. Reforms should aim to decrease barriers to access to public and formal health

  3. An efficient method for generalized linear multiplicative programming problem with multiplicative constraints.

    PubMed

    Zhao, Yingfeng; Liu, Sanyang

    2016-01-01

    We present a practical branch and bound algorithm for globally solving generalized linear multiplicative programming problem with multiplicative constraints. To solve the problem, a relaxation programming problem which is equivalent to a linear programming is proposed by utilizing a new two-phase relaxation technique. In the algorithm, lower and upper bounds are simultaneously obtained by solving some linear relaxation programming problems. Global convergence has been proved and results of some sample examples and a small random experiment show that the proposed algorithm is feasible and efficient. PMID:27547676

  4. Iterated non-linear model predictive control based on tubes and contractive constraints.

    PubMed

    Murillo, M; Sánchez, G; Giovanini, L

    2016-05-01

    This paper presents a predictive control algorithm for non-linear systems based on successive linearizations of the non-linear dynamic around a given trajectory. A linear time varying model is obtained and the non-convex constrained optimization problem is transformed into a sequence of locally convex ones. The robustness of the proposed algorithm is addressed adding a convex contractive constraint. To account for linearization errors and to obtain more accurate results an inner iteration loop is added to the algorithm. A simple methodology to obtain an outer bounding-tube for state trajectories is also presented. The convergence of the iterative process and the stability of the closed-loop system are analyzed. The simulation results show the effectiveness of the proposed algorithm in controlling a quadcopter type unmanned aerial vehicle. PMID:26850752

  5. Polynomial Bell Inequalities

    NASA Astrophysics Data System (ADS)

    Chaves, Rafael

    2016-01-01

    It is a recent realization that many of the concepts and tools of causal discovery in machine learning are highly relevant to problems in quantum information, in particular quantum nonlocality. The crucial ingredient in the connection between both fields is the mathematical theory of causality, allowing for the representation of arbitrary causal structures and providing a rigorous tool to reason about probabilistic causation. Indeed, Bell's theorem concerns a very particular kind of causal structure and Bell inequalities are a special case of linear constraints following from such models. It is thus natural to look for generalizations involving more complex Bell scenarios. The problem, however, relies on the fact that such generalized scenarios are characterized by polynomial Bell inequalities and no current method is available to derive them beyond very simple cases. In this work, we make a significant step in that direction, providing a new, general, and conceptually clear method for the derivation of polynomial Bell inequalities in a wide class of scenarios. We also show how our construction can be used to allow for relaxations of causal constraints and naturally gives rise to a notion of nonsignaling in generalized Bell networks.

  6. Linear Quadratic Tracking Design for a Generic Transport Aircraft with Structural Load Constraints

    NASA Technical Reports Server (NTRS)

    Burken, John J.; Frost, Susan A.; Taylor, Brian R.

    2011-01-01

    When designing control laws for systems with constraints added to the tracking performance, control allocation methods can be utilized. Control allocations methods are used when there are more command inputs than controlled variables. Constraints that require allocators are such task as; surface saturation limits, structural load limits, drag reduction constraints or actuator failures. Most transport aircraft have many actuated surfaces compared to the three controlled variables (such as angle of attack, roll rate & angle of side slip). To distribute the control effort among the redundant set of actuators a fixed mixer approach can be utilized or online control allocation techniques. The benefit of an online allocator is that constraints can be considered in the design whereas the fixed mixer cannot. However, an online control allocator mixer has a disadvantage of not guaranteeing a surface schedule, which can then produce ill defined loads on the aircraft. The load uncertainty and complexity has prevented some controller designs from using advanced allocation techniques. This paper considers actuator redundancy management for a class of over actuated systems with real-time structural load limits using linear quadratic tracking applied to the generic transport model. A roll maneuver example of an artificial load limit constraint is shown and compared to the same no load limitation maneuver.

  7. Plate/shell topological optimization subjected to linear buckling constraints by adopting composite exponential filtering function

    NASA Astrophysics Data System (ADS)

    Ye, Hong-Ling; Wang, Wei-Wei; Chen, Ning; Sui, Yun-Kang

    2016-08-01

    In this paper, a model of topology optimization with linear buckling constraints is established based on an independent and continuous mapping method to minimize the plate/shell structure weight. A composite exponential function (CEF) is selected as filtering functions for element weight, the element stiffness matrix and the element geometric stiffness matrix, which recognize the design variables, and to implement the changing process of design variables from "discrete" to "continuous" and back to "discrete". The buckling constraints are approximated as explicit formulations based on the Taylor expansion and the filtering function. The optimization model is transformed to dual programming and solved by the dual sequence quadratic programming algorithm. Finally, three numerical examples with power function and CEF as filter function are analyzed and discussed to demonstrate the feasibility and efficiency of the proposed method.

  8. A hybrid approach for the modal analysis of continuous systems with discrete piecewise-linear constraints

    NASA Astrophysics Data System (ADS)

    Brake, M. R.

    2011-06-01

    The analysis of continuous systems with piecewise-linear constraints in their domains have previously been limited to either numerical approaches, or analytical methods that are constrained in the parameter space, boundary conditions, or order of the system. The present analysis develops a robust method for studying continuous systems with arbitrary boundary conditions and discrete piecewise-linear constraints. A superposition method is used to generate homogeneous boundary conditions, and modal analysis is used to find the displacement of the system in each state of the piecewise-linear constraint. In order to develop a mapping across each slope discontinuity in the piecewise-linear force-deflection profile, a variational calculus approach is taken that minimizes the L 2 energy norm between the previous and current states. An approach for calculating the finite-time Lyapunov exponents is presented in order to determine chaotic regimes. To illustrate this method, two examples are presented: a pinned-pinned beam with a deadband constraint, and a leaf spring coupled with a connector pin immersed in a viscous fluid. The pinned-pinned beam example illustrates the method for a non-operator based analysis. Results are used to show that the present method does not necessitate the need of a large number of basis functions to adequately map the displacement and velocity of the system across states. In the second example, the leaf spring is modeled as a clamped-free beam. The interaction between the beam and the connector pin is modeled with a preload and a penalty stiffness. Several experiments are conducted in order to validate aspects of the leaf spring model. From the results of the convergence and parameter studies, a high correlation between the finite-time Lyapunov exponents and the contact time per period of the excitation is observed. The parameter studies also indicate that when the system's parameters are changed in order to reduce the magnitude of the impact

  9. Separability of quantum states and the violation of Bell-type inequalities

    SciTech Connect

    Loubenets, Elena R.

    2004-04-01

    In contrast to the widespread opinion that any separable quantum state satisfies every classical probabilistic constraint, we present a simple example where separable quantum state does not satisfy the original Bell inequality although the latter inequality, in its perfect correlation form, is valid for all joint classical measurements. In a very general setting, we discuss inequalities for joint experiments upon a bipartite quantum system. For any separable quantum state, we derive quantum analogs of the original Bell inequality and specify the conditions sufficient for a separable state to satisfy the original Bell inequality. We introduce the extended Clauser-Horne-Shimony-Holt inequality and prove that, for any separable quantum state, this inequality holds for a variety of linear combinations.

  10. LQR problem of linear discrete time systems with nonnegative state constraints

    NASA Astrophysics Data System (ADS)

    Kostova, S.; Imsland, L.; Ivanov, I.

    2015-10-01

    In the paper the infinite-horizon Linear Quadratic Regulator (LQR) problem of linear discrete time systems with non-negative state constraints is presented. Such kind of constraints on the system determine the class of positive systems. They have big application in many fields like economics, biology, ecology, ICT and others. The standard infinite LQR-optimal state feedback law is used for solving the problem. In order to guarantee the nonnegativity of the system states, we define the admissible set of initial states. It is proven that, for each initial state from this set the nonnegative orthant is invariant set. Two cases are considered, first, when the initial state belongs to the admissible set, and the second, when the initial state does not belong to the admissible set. The procedures for solving the problem are given for two cases. In second case we use a dual-mode approach for solving the problem. The first mode is until the state trajectory enters the admissible set and after that the procedure for the first case is used. The illustrative examples are given for both cases.

  11. Linear Approximation to Optimal Control Allocation for Rocket Nozzles with Elliptical Constraints

    NASA Technical Reports Server (NTRS)

    Orr, Jeb S.; Wall, Johnm W.

    2011-01-01

    In this paper we present a straightforward technique for assessing and realizing the maximum control moment effectiveness for a launch vehicle with multiple constrained rocket nozzles, where elliptical deflection limits in gimbal axes are expressed as an ensemble of independent quadratic constraints. A direct method of determining an approximating ellipsoid that inscribes the set of attainable angular accelerations is derived. In the case of a parameterized linear generalized inverse, the geometry of the attainable set is computationally expensive to obtain but can be approximated to a high degree of accuracy with the proposed method. A linear inverse can then be optimized to maximize the volume of the true attainable set by maximizing the volume of the approximating ellipsoid. The use of a linear inverse does not preclude the use of linear methods for stability analysis and control design, preferred in practice for assessing the stability characteristics of the inertial and servoelastic coupling appearing in large boosters. The present techniques are demonstrated via application to the control allocation scheme for a concept heavy-lift launch vehicle.

  12. A Refined Cauchy-Schwarz Inequality

    ERIC Educational Resources Information Center

    Mercer, Peter R.

    2007-01-01

    The author presents a refinement of the Cauchy-Schwarz inequality. He shows his computations in which refinements of the triangle inequality and its reverse inequality are obtained for nonzero x and y in a normed linear space.

  13. Generalized linear joint PP-PS inversion based on two constraints

    NASA Astrophysics Data System (ADS)

    Fang, Yuan; Zhang, Feng-Qi; Wang, Yan-Chun

    2016-03-01

    Conventional joint PP—PS inversion is based on approximations of the Zoeppritz equations and assumes constant VP/VS; therefore, the inversion precision and stability cannot satisfy current exploration requirements. We propose a joint PP—PS inversion method based on the exact Zoeppritz equations that combines Bayesian statistics and generalized linear inversion. A forward model based on the exact Zoeppritz equations is built to minimize the error of the approximations in the large-angle data, the prior distribution of the model parameters is added as a regularization item to decrease the ill-posed nature of the inversion, low-frequency constraints are introduced to stabilize the low-frequency data and improve robustness, and a fast algorithm is used to solve the objective function while minimizing the computational load. The proposed method has superior antinoising properties and well reproduces real data.

  14. Customized Steady-State Constraints for Parameter Estimation in Non-Linear Ordinary Differential Equation Models

    PubMed Central

    Rosenblatt, Marcus; Timmer, Jens; Kaschek, Daniel

    2016-01-01

    Ordinary differential equation models have become a wide-spread approach to analyze dynamical systems and understand underlying mechanisms. Model parameters are often unknown and have to be estimated from experimental data, e.g., by maximum-likelihood estimation. In particular, models of biological systems contain a large number of parameters. To reduce the dimensionality of the parameter space, steady-state information is incorporated in the parameter estimation process. For non-linear models, analytical steady-state calculation typically leads to higher-order polynomial equations for which no closed-form solutions can be obtained. This can be circumvented by solving the steady-state equations for kinetic parameters, which results in a linear equation system with comparatively simple solutions. At the same time multiplicity of steady-state solutions is avoided, which otherwise is problematic for optimization. When solved for kinetic parameters, however, steady-state constraints tend to become negative for particular model specifications, thus, generating new types of optimization problems. Here, we present an algorithm based on graph theory that derives non-negative, analytical steady-state expressions by stepwise removal of cyclic dependencies between dynamical variables. The algorithm avoids multiple steady-state solutions by construction. We show that our method is applicable to most common classes of biochemical reaction networks containing inhibition terms, mass-action and Hill-type kinetic equations. Comparing the performance of parameter estimation for different analytical and numerical methods of incorporating steady-state information, we show that our approach is especially well-tailored to guarantee a high success rate of optimization. PMID:27243005

  15. Customized Steady-State Constraints for Parameter Estimation in Non-Linear Ordinary Differential Equation Models.

    PubMed

    Rosenblatt, Marcus; Timmer, Jens; Kaschek, Daniel

    2016-01-01

    Ordinary differential equation models have become a wide-spread approach to analyze dynamical systems and understand underlying mechanisms. Model parameters are often unknown and have to be estimated from experimental data, e.g., by maximum-likelihood estimation. In particular, models of biological systems contain a large number of parameters. To reduce the dimensionality of the parameter space, steady-state information is incorporated in the parameter estimation process. For non-linear models, analytical steady-state calculation typically leads to higher-order polynomial equations for which no closed-form solutions can be obtained. This can be circumvented by solving the steady-state equations for kinetic parameters, which results in a linear equation system with comparatively simple solutions. At the same time multiplicity of steady-state solutions is avoided, which otherwise is problematic for optimization. When solved for kinetic parameters, however, steady-state constraints tend to become negative for particular model specifications, thus, generating new types of optimization problems. Here, we present an algorithm based on graph theory that derives non-negative, analytical steady-state expressions by stepwise removal of cyclic dependencies between dynamical variables. The algorithm avoids multiple steady-state solutions by construction. We show that our method is applicable to most common classes of biochemical reaction networks containing inhibition terms, mass-action and Hill-type kinetic equations. Comparing the performance of parameter estimation for different analytical and numerical methods of incorporating steady-state information, we show that our approach is especially well-tailored to guarantee a high success rate of optimization. PMID:27243005

  16. VLSI floorplan repair using dynamic white-space management, constraint graphs, and linear programming

    NASA Astrophysics Data System (ADS)

    Vorwerk, Kristoffer; Kennings, Andrew; Anjos, Miguel

    2008-06-01

    In VLSI layout, floorplanning refers to the task of placing macrocells on a chip without overlap while minimizing design objectives such as timing, congestion, and wire length. Experienced VLSI designers have traditionally been able to produce more efficient floorplans than automated methods. However, with the increasing complexity of modern circuits, manual design flows have become infeasible. An efficient top-down strategy for overlap removal which repairs overlaps in floorplans produced by placement algorithms or rough floorplanning methodologies is presented in this article. The algorithmic framework proposed incorporates a novel geometric shifting technique coupled with topological constraint graphs and linear programming within a top-down flow. The effectiveness of this framework is quantified across a broad range of floorplans produced by multiple tools. The method succeeds in producing valid placements in almost all cases; moreover, compared with leading methods, it requires only one-fifth of the run-time and produces placements with 4-13% less wire length and up to 43% less cell movement.

  17. A Linear Programming Approach to the Development of Contrail Reduction Strategies Satisfying Operationally Feasible Constraints

    NASA Technical Reports Server (NTRS)

    Wei, Peng; Sridhar, Banavar; Chen, Neil Yi-Nan; Sun, Dengfent

    2012-01-01

    A class of strategies has been proposed to reduce contrail formation in the United States airspace. A 3D grid based on weather data and the cruising altitude level of aircraft is adjusted to avoid the persistent contrail potential area with the consideration to fuel-efficiency. In this paper, the authors introduce a contrail avoidance strategy on 3D grid by considering additional operationally feasible constraints from an air traffic controller's aspect. First, shifting too many aircraft to the same cruising level will make the miles-in-trail at this level smaller than the safety separation threshold. Furthermore, the high density of aircraft at one cruising level may exceed the workload for the traffic controller. Therefore, in our new model we restrict the number of total aircraft at each level. Second, the aircraft count variation for successive intervals cannot be too drastic since the workload to manage climbing/descending aircraft is much larger than managing cruising aircraft. The contrail reduction is formulated as an integer-programming problem and the problem is shown to have the property of total unimodularity. Solving the corresponding relaxed linear programming with the simplex method provides an optimal and integral solution to the problem. Simulation results are provided to illustrate the methodology.

  18. A generating set direct search augmented Lagrangian algorithm for optimization with a combination of general and linear constraints.

    SciTech Connect

    Lewis, Robert Michael (College of William and Mary, Williamsburg, VA); Torczon, Virginia Joanne (College of William and Mary, Williamsburg, VA); Kolda, Tamara Gibson

    2006-08-01

    We consider the solution of nonlinear programs in the case where derivatives of the objective function and nonlinear constraints are unavailable. To solve such problems, we propose an adaptation of a method due to Conn, Gould, Sartenaer, and Toint that proceeds by approximately minimizing a succession of linearly constrained augmented Lagrangians. Our modification is to use a derivative-free generating set direct search algorithm to solve the linearly constrained subproblems. The stopping criterion proposed by Conn, Gould, Sartenaer and Toint for the approximate solution of the subproblems requires explicit knowledge of derivatives. Such information is presumed absent in the generating set search method we employ. Instead, we show that stationarity results for linearly constrained generating set search methods provide a derivative-free stopping criterion, based on a step-length control parameter, that is sufficient to preserve the convergence properties of the original augmented Lagrangian algorithm.

  19. Minkowski–Weyl Priors for Models With Parameter Constraints: An Analysis of the BioCycle Study

    PubMed Central

    Danaher, Michelle R.; Roy, Anindya; Chen, Zhen; Mumford, Sunni L.; Schisterman, Enrique F.

    2016-01-01

    We propose a general framework for performing full Bayesian analysis under linear inequality parameter constraints. The proposal is motivated by the BioCycle Study, a large cohort study of hormone levels of healthy women where certain well-established linear inequality constraints on the log-hormone levels should be accounted for in the statistical inferential procedure. Based on the Minkowski–Weyl decomposition of polyhedral regions, we propose a class of priors that are fully supported on the parameter space with linear inequality constraints, and we fit a Bayesian linear mixed model to the BioCycle data using such a prior. We observe positive associations between estrogen and progesterone levels and F2-isoprostanes, a marker for oxidative stress. These findings are of particular interest to reproductive epidemiologists. PMID:27099406

  20. Evaluation of the improved linear emissivity constraint temperature and emissivity separation method by using the simulated hyperspectral thermal infrared data

    NASA Astrophysics Data System (ADS)

    Wu, Hua; Li, Zhao-Liang; Tang, Bo-Hui; Tang, Rong-Lin

    2015-12-01

    In this study, an improved linear emissivity constraint temperature and emissivity separation (I-LECTES) method was first proposed to overcome the discontinuities problem of the retrieved land surface emissivities (LSEs) in the former linear emissivity constraint temperature and emissivity separation (LECTES) method. Consequently, the hyperspectral thermal infrared data were carefully simulated according to the configuration of Designs & Prototypes microFTIR Model 102, and were used to evaluate the performance of the I-LECTES method. Meanwhile, the I-LECTES method was also compared with the LECTES method. Different the atmosphere and surface circumstances were considered, as well as the different levels of noise equivalent temperature difference (NEΔT). The results showed that the proposed I-LECTES method is of a better accuracy compared with the LECTES method and has the characteristic of keeping the retrieved LSEs continuous, which sounds more reasonable. Because the noises in the ground measured radiance may have more effects on the accuracies of land surface temperature (LST) and LSEs than those in the atmospheric downwelling radiance, the noise in the ground measured radiance should be removed as much as possible to improve the accuracies of retrieved LST and LSEs. Furthermore, taken into account the lower retrieval accuracies for the cold and dry atmosphere, both the I-LECTES method and the LECTES method should be taken a full consideration. The proposed method is regarded to be promising because of its holding continuity and noise-immune.

  1. A fresh look at linear cosmological constraints on a decaying Dark Matter component

    NASA Astrophysics Data System (ADS)

    Poulin, Vivian; Serpico, Pasquale D.; Lesgourgues, Julien

    2016-08-01

    We consider a cosmological model in which a fraction fdcdm of the Dark Matter (DM) is allowed to decay in an invisible relativistic component, and compute the resulting constraints on both the decay width (or inverse lifetime) Γdcdm and fdcdm from purely gravitational arguments. We report a full derivation of the Boltzmann hierarchy, correcting a mistake in previous literature, and compute the impact of the decay—as a function of the lifetime—on the CMB and matter power spectra. From CMB only, we obtain that no more than 3.8% of the DM could have decayed in the time between recombination and today (all bounds quoted at 95% CL). We also comment on the important application of this bound to the case where primordial black holes constitute DM, a scenario notoriously difficult to constrain. For lifetimes longer than the age of the Universe, the bounds can be cast as fdcdmΓdcdm < 6.3×10‑3 Gyr‑1. For the first time, we also checked that degeneracies with massive neutrinos are broken when information from the large scale structure is used. Even secondary effects like CMB lensing suffice to this purpose. Decaying DM models have been invoked to solve a possible tension between low redshift astronomical measurements of σ8 and Ωm and the ones inferred by Planck. We reassess this claim finding that with the most recent BAO, HST and σ8 data extracted from the CFHT survey, the tension is only slightly reduced despite the two additional free parameters. Nonetheless, the existing tension explains why the bound on fdcdmΓdcdm loosens to fdcdmΓdcdm < 15.9×10‑3 Gyr‑1 when including such additional data. The bound however improves to fdcdmΓdcdm < 5.9 ×10‑3 Gyr‑1 if only data consistent with the CMB are included. This highlights the importance of establishing whether the tension is due to real physical effects or unaccounted systematics, for settling the reach of achievable constraints on decaying DM.

  2. Kalman Duality Principle for a Class of Ill-Posed Minimax Control Problems with Linear Differential-Algebraic Constraints

    SciTech Connect

    Zhuk, Sergiy

    2013-10-15

    In this paper we present Kalman duality principle for a class of linear Differential-Algebraic Equations (DAE) with arbitrary index and time-varying coefficients. We apply it to an ill-posed minimax control problem with DAE constraint and derive a corresponding dual control problem. It turns out that the dual problem is ill-posed as well and so classical optimality conditions are not applicable in the general case. We construct a minimizing sequence u-circumflex{sub {epsilon}} for the dual problem applying Tikhonov method. Finally we represent u-circumflex{sub {epsilon}} in the feedback form using Riccati equation on a subspace which corresponds to the differential part of the DAE.

  3. A Stationary North-Finding Scheme for an Azimuth Rotational IMU Utilizing a Linear State Equality Constraint

    PubMed Central

    Yu, Huapeng; Zhu, Hai; Gao, Dayuan; Yu, Meng; Wu, Wenqi

    2015-01-01

    The Kalman filter (KF) has always been used to improve north-finding performance under practical conditions. By analyzing the characteristics of the azimuth rotational inertial measurement unit (ARIMU) on a stationary base, a linear state equality constraint for the conventional KF used in the fine north-finding filtering phase is derived. Then, a constrained KF using the state equality constraint is proposed and studied in depth. Estimation behaviors of the concerned navigation errors when implementing the conventional KF scheme and the constrained KF scheme during stationary north-finding are investigated analytically by the stochastic observability approach, which can provide explicit formulations of the navigation errors with influencing variables. Finally, multiple practical experimental tests at a fixed position are done on a postulate system to compare the stationary north-finding performance of the two filtering schemes. In conclusion, this study has successfully extended the utilization of the stochastic observability approach for analytic descriptions of estimation behaviors of the concerned navigation errors, and the constrained KF scheme has demonstrated its superiority over the conventional KF scheme for ARIMU stationary north-finding both theoretically and practically. PMID:25688588

  4. A stationary north-finding scheme for an azimuth rotational IMU utilizing a linear state equality constraint.

    PubMed

    Yu, Huapeng; Zhu, Hai; Gao, Dayuan; Yu, Meng; Wu, Wenqi

    2015-01-01

    The Kalman filter (KF) has always been used to improve north-finding performance under practical conditions. By analyzing the characteristics of the azimuth rotational inertial measurement unit (ARIMU) on a stationary base, a linear state equality constraint for the conventional KF used in the fine north-finding filtering phase is derived. Then, a constrained KF using the state equality constraint is proposed and studied in depth. Estimation behaviors of the concerned navigation errors when implementing the conventional KF scheme and the constrained KF scheme during stationary north-finding are investigated analytically by the stochastic observability approach, which can provide explicit formulations of the navigation errors with influencing variables. Finally, multiple practical experimental tests at a fixed position are done on a postulate system to compare the stationary north-finding performance of the two filtering schemes. In conclusion, this study has successfully extended the utilization of the stochastic observability approach for analytic descriptions of estimation behaviors of the concerned navigation errors, and the constrained KF scheme has demonstrated its superiority over the conventional KF scheme for ARIMU stationary north-finding both theoretically and practically. PMID:25688588

  5. Solution of two-level variational inequality

    SciTech Connect

    Kalashnikov, V.V.; Kalashnikova, N.I.

    1995-03-01

    The mathematical programming problem with variational inequality constraints, or the complementary problem, often arises in the analysis of physical and socio-economic systems. At present, such problems are mostly solved by heuristic methods. In a recent paper, Harker and Choi described an approach based on external penalty functions, which is applied after restating the variational inequality constraint in optimization form. An alternative approach to the solution of the problem conversely involves restating its optimization part in the form of an appropriate variational inequality, whose solution is then sought on the set of feasible vectors that satisfy the original inequality constraint. In this paper, we propose a penalty technique for solving the resulting problem, which is accordingly reduced to a one-level variational inequality dependent on a penalty parameter.

  6. A fast multigrid algorithm for energy minimization under planar density constraints.

    SciTech Connect

    Ron, D.; Safro, I.; Brandt, A.; Mathematics and Computer Science; Weizmann Inst. of Science

    2010-09-07

    The two-dimensional layout optimization problem reinforced by the efficient space utilization demand has a wide spectrum of practical applications. Formulating the problem as a nonlinear minimization problem under planar equality and/or inequality density constraints, we present a linear time multigrid algorithm for solving a correction to this problem. The method is demonstrated in various graph drawing (visualization) instances.

  7. Comparison of the Singer method and the constraints method for molecular dynamics with linear molecules on the vector computer CYBER 205

    NASA Astrophysics Data System (ADS)

    Hoheisel, C.; Vogelsang, R.; Schoen, M.

    1987-01-01

    The vectorization of FORTRAN programmes for the computation of the forces in molecular dynamics (MD) calculations are described. For systems containing linear molecules, two equivalent MD methods can be used: the Singer method and the constraints method. The FORTRAN vector code is presented and discussed for both methods. A comparison of computational times on the CYBER 205 is presented. For the two-centre Lennard-Jones potential, the constraints algorithm becomes increasingly less efficient than the Singer algorithm when executed on the CYBER 205. The reason for this is the difference in the neighbour-list which is made for the centre of each molecule in the Singer method and for each site in the molecule in the constraints method. Both programmes run about a factor of 15 faster on the Cyber 205 than on the conventional computer Cyber 175, for 108 or 256 linear molecules.

  8. Strong monogamy inequalities for four qubits

    NASA Astrophysics Data System (ADS)

    Regula, Bartosz; Osterloh, Andreas; Adesso, Gerardo

    2016-05-01

    We investigate possible generalizations of the Coffman-Kundu-Wootters monogamy inequality to four qubits, accounting for multipartite entanglement in addition to the bipartite terms. We show that the most natural extension of the inequality does not hold in general, and we describe the violations of this inequality in detail. We investigate alternative ways to extend the monogamy inequality to express a constraint on entanglement sharing valid for all four-qubit states, and perform an extensive numerical analysis of randomly generated four-qubit states to explore the properties of such extensions.

  9. A “Reverse-Schur” Approach to Optimization With Linear PDE Constraints: Application to Biomolecule Analysis and Design

    PubMed Central

    Bardhan, Jaydeep P.; Altman, Michael D.

    2009-01-01

    We present a partial-differential-equation (PDE)-constrained approach for optimizing a molecule’s electrostatic interactions with a target molecule. The approach, which we call reverse-Schur co-optimization, can be more than two orders of magnitude faster than the traditional approach to electrostatic optimization. The efficiency of the co-optimization approach may enhance the value of electrostatic optimization for ligand-design efforts–in such projects, it is often desirable to screen many candidate ligands for their viability, and the optimization of electrostatic interactions can improve ligand binding affinity and specificity. The theoretical basis for electrostatic optimization derives from linear-response theory, most commonly continuum models, and simple assumptions about molecular binding processes. Although the theory has been used successfully to study a wide variety of molecular binding events, its implications have not yet been fully explored, in part due to the computational expense associated with the optimization. The co-optimization algorithm achieves improved performance by solving the optimization and electrostatic simulation problems simultaneously, and is applicable to both unconstrained and constrained optimization problems. Reverse-Schur co-optimization resembles other well-known techniques for solving optimization problems with PDE constraints. Model problems as well as realistic examples validate the reverse-Schur method, and demonstrate that our technique and alternative PDE-constrained methods scale very favorably compared to the standard approach. Regularization, which ordinarily requires an explicit representation of the objective function, can be included using an approximate Hessian calculated using the new BIBEE/P (boundary-integral-based electrostatics estimation by preconditioning) method. PMID:23055839

  10. Visualizing inequality

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2016-07-01

    The study of socioeconomic inequality is of substantial importance, scientific and general alike. The graphic visualization of inequality is commonly conveyed by Lorenz curves. While Lorenz curves are a highly effective statistical tool for quantifying the distribution of wealth in human societies, they are less effective a tool for the visual depiction of socioeconomic inequality. This paper introduces an alternative to Lorenz curves-the hill curves. On the one hand, the hill curves are a potent scientific tool: they provide detailed scans of the rich-poor gaps in human societies under consideration, and are capable of accommodating infinitely many degrees of freedom. On the other hand, the hill curves are a powerful infographic tool: they visualize inequality in a most vivid and tangible way, with no quantitative skills that are required in order to grasp the visualization. The application of hill curves extends far beyond socioeconomic inequality. Indeed, the hill curves are highly effective 'hyperspectral' measures of statistical variability that are applicable in the context of size distributions at large. This paper establishes the notion of hill curves, analyzes them, and describes their application in the context of general size distributions.

  11. QCD inequalities for hadron interactions.

    PubMed

    Detmold, William

    2015-06-01

    We derive generalizations of the Weingarten-Witten QCD mass inequalities for particular multihadron systems. For systems of any number of identical pseudoscalar mesons of maximal isospin, these inequalities prove that near threshold interactions between the constituent mesons must be repulsive and that no bound states can form in these channels. Similar constraints in less symmetric systems are also extracted. These results are compatible with experimental results (where known) and recent lattice QCD calculations, and also lead to a more stringent bound on the nucleon mass than previously derived, m_{N}≥3/2m_{π}. PMID:26196617

  12. Noncontextuality Inequalities

    NASA Astrophysics Data System (ADS)

    Spekkens, Robert

    2010-03-01

    The Bell-Kochen-Specker theorem demonstrates that the predictions of quantum theory are inconsistent with a noncontextual hidden variable model. Significantly, the notion of noncontextuality to which it appeals is only well-defined for models of quantum theory as opposed to models of an arbitrary physical theory and then only for projective measurements and deterministic models thereof. By contrast, the notion of local causality introduced by Bell is not so restricted in its scope. In this talk, I present an operational definition of noncontextuality that recovers the traditional notion as a special case and allows one to define ``noncontextuality inequalities'' for experimental statistics. I will demonstrate that a particular two-party information-processing task, ``parity-oblivious multiplexing,'' is powered by contextuality in the sense that there is an inequality that bounds its performance in noncontextual models, and I will report on an experimental violation of this inequality in good agreement with the quantum predictions. Joint work with Daniel Buzacott, Tony Keehn, Ben Toner and Geoff Pryde.

  13. Entropy inequalities and Bell inequalities for two-qubit systems

    SciTech Connect

    Santos, Emilio

    2004-02-01

    Sufficient conditions for the nonviolation of the Bell-Clauser-Horne-Shimony-Holt inequalities in a mixed state of a two-qubit system are: (1) the linear entropy of the state is not smaller than 0.457; (2) the sum of the conditional linear entropies is not smaller than -0.086; (3) the von Neumann entropy is not smaller than 0.833; and (4) the sum of the conditional von Neumann entropies is not smaller than 0.280.

  14. Experimental constraints on non-linearities induced by two-photon effects in elastic and inelastic Rosenbluth separations

    SciTech Connect

    Vladas Tvaskis; John Arrington; Michael Christy; Rolf Ent; Cynthia Keppel; Yongguang Liang; Grahame Vittorini

    2006-01-26

    The effects of two-photon exchange corrections, suggested to explain the difference between measurements of the proton elastic electromagnetic form factors using the polarization transfer and Rosenbluth techniques, have been studied in elastic and inelastic scattering data. Such corrections could introduce epsilon-dependent non-linearities in inelastic Rosenbluth separations, where epsilon is the virtual photon polarization parameter. It is concluded that such non-linear effects are consistent with zero for elastic, resonance, and deep-inelastic scattering for all Q{sup 2} and W{sup 2} values measured.

  15. ON THE MIGRATION OF JUPITER AND SATURN: CONSTRAINTS FROM LINEAR MODELS OF SECULAR RESONANT COUPLING WITH THE TERRESTRIAL PLANETS

    SciTech Connect

    Agnor, Craig B.; Lin, D. N. C.

    2012-02-01

    We examine how the late divergent migration of Jupiter and Saturn may have perturbed the terrestrial planets. Using a modified secular model we have identified six secular resonances between the {nu}{sub 5} frequency of Jupiter and Saturn and the four apsidal eigenfrequencies of the terrestrial planets (g{sub 1-4}). We derive analytic upper limits on the eccentricity and orbital migration timescale of Jupiter and Saturn when these resonances were encountered to avoid perturbing the eccentricities of the terrestrial planets to values larger than the observed ones. Because of the small amplitudes of the j = 2, 3 terrestrial eigenmodes the g{sub 2} - {nu}{sub 5} and g{sub 3} - {nu}{sub 5} resonances provide the strongest constraints on giant planet migration. If Jupiter and Saturn migrated with eccentricities comparable to their present-day values, smooth migration with exponential timescales characteristic of planetesimal-driven migration ({tau} {approx} 5-10 Myr) would have perturbed the eccentricities of the terrestrial planets to values greatly exceeding the observed ones. This excitation may be mitigated if the eccentricity of Jupiter was small during the migration epoch, migration was very rapid (e.g., {tau} {approx}< 0.5 Myr perhaps via planet-planet scattering or instability-driven migration) or the observed small eccentricity amplitudes of the j = 2, 3 terrestrial modes result from low probability cancellation of several large amplitude contributions. Results of orbital integrations show that very short migration timescales ({tau} < 0.5 Myr), characteristic of instability-driven migration, may also perturb the terrestrial planets' eccentricities by amounts comparable to their observed values. We discuss the implications of these constraints for the relative timing of terrestrial planet formation, giant planet migration, and the origin of the so-called Late Heavy Bombardment of the Moon 3.9 {+-} 0.1 Ga ago. We suggest that the simplest way to satisfy these

  16. Quantum Griffiths Inequalities

    NASA Astrophysics Data System (ADS)

    Miyao, Tadahiro

    2016-07-01

    We present a general framework of Griffiths inequalities for quantum systems. Our approach is based on operator inequalities associated with self-dual cones and provides a consistent viewpoint of the Griffiths inequality. As examples, we discuss the quantum Ising model, quantum rotor model, Bose-Hubbard model, and Hubbard model. We present a model-independent structure that governs the correlation inequalities.

  17. Quantum Griffiths Inequalities

    NASA Astrophysics Data System (ADS)

    Miyao, Tadahiro

    2016-06-01

    We present a general framework of Griffiths inequalities for quantum systems. Our approach is based on operator inequalities associated with self-dual cones and provides a consistent viewpoint of the Griffiths inequality. As examples, we discuss the quantum Ising model, quantum rotor model, Bose-Hubbard model, and Hubbard model. We present a model-independent structure that governs the correlation inequalities.

  18. Constraints on timing and magnitude of early global expansion of the Moon from topographic features in linear gravity anomaly areas

    NASA Astrophysics Data System (ADS)

    Sawada, Natsuki; Morota, Tomokatsu; Kato, Shinsuke; Ishihara, Yoshiaki; Hiramatsu, Yoshihiro

    2016-05-01

    Gravity data obtained from the Gravity Recovery and Interior Laboratory have revealed linear gravity anomalies (LGAs) formed by the early global expansion of the Moon and subsequent magma intrusion. In this study, using Lunar Orbiter Laser Altimeter topographic data, we investigated topographic profiles across LGAs to verify that they were formed by extensional tectonics. We found that 17 of the 20 LGAs investigated exhibited a valley structure, suggesting that they were formed by tensile stress. Assuming that these topographic depressions accompanied graben formation, the increase in the lunar radius is estimated to be on the order of several tens of meters. On the other hand, assuming that these topographic depressions accompanied flexure of elastic lithosphere due to the LGA load, the elastic thickness during the LGA formation is estimated as ~10 km. The crater frequencies in the vicinity of LGAs indicate that the peak tectonic activity occurred before the basin-forming epoch.

  19. Input-output finite-time stabilization of linear systems with finite-time boundedness.

    PubMed

    Guo, Yang; Yao, Yu; Wang, Shicheng; Ma, Kemao; Liu, Kai; Guo, Jian

    2014-07-01

    The paper presents linear system Input-Output Finite-Time Stabilization (IO-FTS) method under Finite-Time Boundedness (FTB) constraint. A state feedback controller is designed, via Linear Matrix Inequalities (LMIs), to guarantee the system both IO-FTS and FTB. The proposed methods are applied to the guidance design of a class of terminal guidance systems to suppress disturbances with IO-FTS method and FTB constraints simultaneously satisfied. The simulation results illustrate the effectiveness of the proposed methods. PMID:24947432

  20. Isoperimetric inequality on conformally hyperbolic manifolds

    SciTech Connect

    Kesel'man, V M

    2003-04-30

    It is shown that on an arbitrary non-compact Riemannian manifold of conformally hyperbolic type the isoperimetric inequality can be taken by a conformal change of the metric to the same canonical linear form as in the case of the standard hyperbolic Lobachevskii space. Both the absolute isoperimetric inequality and the relative one (for manifolds with boundary) are obtained. This work develops the results and methods of a joint paper with Zorich, in which the absolute isoperimetric inequality was obtained under a certain additional condition; the resulting statements are definitive in a certain sense.

  1. Constraints on the broad line region from regularized linear inversion: velocity-delay maps for five nearby active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Skielboe, Andreas; Pancoast, Anna; Treu, Tommaso; Park, Daeseong; Barth, Aaron J.; Bentz, Misty C.

    2015-11-01

    Reverberation mapping probes the structure of the broad emission-line region (BLR) in active galactic nuclei (AGN). The kinematics of the BLR gas can be used to measure the mass of the central supermassive black hole. The main uncertainty affecting black hole mass determinations is the structure of the BLR. We present a new method for reverberation mapping based on regularized linear inversion (RLI) that includes modelling of the AGN continuum light curves. This enables fast calculation of velocity-resolved response maps to constrain BLR structure. RLI allows for negative response, such as when some areas of the BLR respond in inverse proportion to a change in ionizing continuum luminosity. We present time delays, integrated response functions, and velocity-delay maps for the H β broad emission line in five nearby AGN, as well as for H α and H γ in Arp 151, using data from the Lick AGN Monitoring Project 2008. We find indications of prompt response in three of the objects (Arp 151, NGC 5548, and SBS 1116+583A) with additional prompt response in the red wing of H β. In SBS 1116+583A we find evidence for a multimodal broad prompt response followed by a second narrow response at 10 d. We find no clear indications of negative response. The results are complementary to, and consistent with, other methods such as cross-correlation, maximum entropy, and dynamical modelling. RLI with continuum light-curve modelling provides a fast, complementary method for velocity-resolved reverberation mapping and is suitable for use on large data sets.

  2. Kalman Filter Constraint Tuning for Turbofan Engine Health Estimation

    NASA Technical Reports Server (NTRS)

    Simon, Dan; Simon, Donald L.

    2005-01-01

    Kalman filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints are often neglected because they do not fit easily into the structure of the Kalman filter. Recently published work has shown a new method for incorporating state variable inequality constraints in the Kalman filter, which has been shown to generally improve the filter s estimation accuracy. However, the incorporation of inequality constraints poses some risk to the estimation accuracy as the Kalman filter is theoretically optimal. This paper proposes a way to tune the filter constraints so that the state estimates follow the unconstrained (theoretically optimal) filter when the confidence in the unconstrained filter is high. When confidence in the unconstrained filter is not so high, then we use our heuristic knowledge to constrain the state estimates. The confidence measure is based on the agreement of measurement residuals with their theoretical values. The algorithm is demonstrated on a linearized simulation of a turbofan engine to estimate engine health.

  3. The Price of Inequality

    ERIC Educational Resources Information Center

    Jensen, Arthur R.

    1975-01-01

    Some of the key problems of educational equality -- equality of opportunities and inequality of performance; individual differences vs. group differences, coping with group inequality -- are made explicit. (Author/KM)

  4. Graphing Inequalities, Connecting Meaning

    ERIC Educational Resources Information Center

    Switzer, J. Matt

    2014-01-01

    Students often have difficulty with graphing inequalities (see Filloy, Rojano, and Rubio 2002; Drijvers 2002), and J. Matt Switzer's students were no exception. Although students can produce graphs for simple inequalities, they often struggle when the format of the inequality is unfamiliar. Even when producing a correct graph of an…

  5. Inequality aversion, health inequalities and health achievement.

    PubMed

    Wagstaff, Adam

    2002-07-01

    This paper addresses two issues. The first is how health inequalities can be measured in such a way as to take into account policymakers' attitudes towards inequality. The Gini coefficient and the related concentration index embody one particular set of value judgements. By generalising these indices, alternative sets of value judgements can be reflected. The other issue addressed is how information on health inequality can be used together with information on the mean of the relevant distribution to obtain an overall measure of health "achievement". PMID:12146594

  6. Null steering of adaptive beamforming using linear constraint minimum variance assisted by particle swarm optimization, dynamic mutated artificial immune system, and gravitational search algorithm.

    PubMed

    Darzi, Soodabeh; Kiong, Tiong Sieh; Islam, Mohammad Tariqul; Ismail, Mahamod; Kibria, Salehin; Salem, Balasem

    2014-01-01

    Linear constraint minimum variance (LCMV) is one of the adaptive beamforming techniques that is commonly applied to cancel interfering signals and steer or produce a strong beam to the desired signal through its computed weight vectors. However, weights computed by LCMV usually are not able to form the radiation beam towards the target user precisely and not good enough to reduce the interference by placing null at the interference sources. It is difficult to improve and optimize the LCMV beamforming technique through conventional empirical approach. To provide a solution to this problem, artificial intelligence (AI) technique is explored in order to enhance the LCMV beamforming ability. In this paper, particle swarm optimization (PSO), dynamic mutated artificial immune system (DM-AIS), and gravitational search algorithm (GSA) are incorporated into the existing LCMV technique in order to improve the weights of LCMV. The simulation result demonstrates that received signal to interference and noise ratio (SINR) of target user can be significantly improved by the integration of PSO, DM-AIS, and GSA in LCMV through the suppression of interference in undesired direction. Furthermore, the proposed GSA can be applied as a more effective technique in LCMV beamforming optimization as compared to the PSO technique. The algorithms were implemented using Matlab program. PMID:25147859

  7. Null Steering of Adaptive Beamforming Using Linear Constraint Minimum Variance Assisted by Particle Swarm Optimization, Dynamic Mutated Artificial Immune System, and Gravitational Search Algorithm

    PubMed Central

    Sieh Kiong, Tiong; Tariqul Islam, Mohammad; Ismail, Mahamod; Salem, Balasem

    2014-01-01

    Linear constraint minimum variance (LCMV) is one of the adaptive beamforming techniques that is commonly applied to cancel interfering signals and steer or produce a strong beam to the desired signal through its computed weight vectors. However, weights computed by LCMV usually are not able to form the radiation beam towards the target user precisely and not good enough to reduce the interference by placing null at the interference sources. It is difficult to improve and optimize the LCMV beamforming technique through conventional empirical approach. To provide a solution to this problem, artificial intelligence (AI) technique is explored in order to enhance the LCMV beamforming ability. In this paper, particle swarm optimization (PSO), dynamic mutated artificial immune system (DM-AIS), and gravitational search algorithm (GSA) are incorporated into the existing LCMV technique in order to improve the weights of LCMV. The simulation result demonstrates that received signal to interference and noise ratio (SINR) of target user can be significantly improved by the integration of PSO, DM-AIS, and GSA in LCMV through the suppression of interference in undesired direction. Furthermore, the proposed GSA can be applied as a more effective technique in LCMV beamforming optimization as compared to the PSO technique. The algorithms were implemented using Matlab program. PMID:25147859

  8. Educational Inequality and Income Inequality: An Empirical Study on China

    ERIC Educational Resources Information Center

    Yang, Jun; Huang, Xiao; Li, Xiaoyu

    2009-01-01

    Based on the endogenous growth theory, this paper uses the Gini coefficient to measure educational inequality and studies the empirical relationship between educational inequality and income inequality through a simultaneous equation model. The results show that: (1) Income inequality leads to educational inequality while the reduction of…

  9. Aggregation-based fuzzy dual-mode control for nonlinear systems with mixed constraints

    NASA Astrophysics Data System (ADS)

    Wen, Jiwei; Liu, Fei

    2012-05-01

    A new receding horizon dual-mode control method is proposed for a class of discrete-time nonlinear systems represented by Takagi-Sugeno (T-S) fuzzy models subject to mixed constraints including hard input constraint and soft state constraint. On the one hand, our receding horizon scheme is based upon an online optimisation that utilises optimised sequence plus local linear feedback. On the other hand, due to the consideration of computation burden, an amplitude decaying aggregation strategy is introduced to reduce the number of optimisation variables. The proposed controller is obtained using semi-definite programming, which can be easily solved by means of linear matrix inequalities. A numerical example is given to verify the feasibility and efficiency of the proposed method.

  10. A stochastic framework for inequality constrained estimation

    NASA Astrophysics Data System (ADS)

    Roese-Koerner, Lutz; Devaraju, Balaji; Sneeuw, Nico; Schuh, Wolf-Dieter

    2012-11-01

    Quality description is one of the key features of geodetic inference. This is even more true if additional information about the parameters is available that could improve the accuracy of the estimate. However, if such additional information is provided in the form of inequality constraints, most of the standard tools of quality description (variance propagation, confidence ellipses, etc.) cannot be applied, as there is no analytical relationship between parameters and observations. Some analytical methods have been developed for describing the quality of inequality constrained estimates. However, these methods either ignore the probability mass in the infeasible region or the influence of inactive constraints and therefore yield only approximate results. In this article, a frequentist framework for quality description of inequality constrained least-squares estimates is developed, based on the Monte Carlo method. The quality is described in terms of highest probability density regions. Beyond this accuracy estimate, the proposed method allows to determine the influence and contribution of each constraint on each parameter using Lagrange multipliers. Plausibility of the constraints is checked by hypothesis testing and estimating the probability mass in the infeasible region. As more probability mass concentrates in less space, applying the proposed method results in smaller confidence regions compared to the unconstrained ordinary least-squares solution. The method is applied to describe the quality of estimates in the problem of approximating a time series with positive definite functions.

  11. The evolution of inequality.

    PubMed

    Mattison, Siobhán M; Smith, Eric A; Shenk, Mary K; Cochrane, Ethan E

    2016-07-01

    Understanding how systems of political and economic inequality evolved from relatively egalitarian origins has long been a focus of anthropological inquiry. Many hypotheses have been suggested to link socio-ecological features with the rise and spread of inequality, and empirical tests of these hypotheses in prehistoric and extant societies are increasing. In this review, we synthesize several streams of theory relevant to understanding the evolutionary origins, spread, and adaptive significance of inequality. We argue that while inequality may be produced by a variety of localized processes, its evolution is fundamentally dependent on the economic defensibility and transmissibility of wealth. Furthermore, these properties of wealth could become persistent drivers of inequality only following a shift to a more stable climate in the Holocene. We conclude by noting several key areas for future empirical research, emphasizing the need for more analyses of contemporary shifts toward institutionalized inequality as well as prehistoric cases. PMID:27519458

  12. Inequalities in Science

    PubMed Central

    Xie, Y.

    2014-01-01

    Inequalities in scientists’ contributions to science and their rewards have always been very high. There are good reasons to propose that inequalities in science across research institutions and across individual scientists have increased in recent years. In the meantime, however, globalization and internet technology have narrowed inequalities in science across nations and facilitated the expansion of science and rapid production of scientific discoveries through international collaborative networks. PMID:24855244

  13. Maximal Violation of the Collins-Gisin-Linden-Massar-Popescu Inequality for Infinite Dimensional States

    NASA Astrophysics Data System (ADS)

    Zohren, Stefan; Gill, Richard D.

    2008-03-01

    We present a much simplified version of the Collins-Gisin-Linden-Massar-Popescu inequality for the 2×2×d Bell scenario. Numerical maximization of the violation of this inequality over all states and measurements suggests that the optimal state is far from maximally entangled, while the best measurements are the same as conjectured best measurements for the maximally entangled state. For very large values of d the inequality seems to reach its minimal value given by the probability constraints. This gives numerical evidence for a tight quantum Bell inequality (or generalized Csirelson inequality) for the 2×2×∞ scenario.

  14. An Application of Sylvester's Rank Inequality

    ERIC Educational Resources Information Center

    Kung, Sidney H.

    2011-01-01

    Using two well known criteria for the diagonalizability of a square matrix plus an extended form of Sylvester's Rank Inequality, the author presents a new condition for the diagonalization of a real matrix from which one can obtain the eigenvectors by simply multiplying some associated matrices without solving a linear system of simultaneous…

  15. Health Inequality and Careers

    ERIC Educational Resources Information Center

    Robertson, Peter J.

    2014-01-01

    Structural explanations of career choice and development are well established. Socioeconomic inequality represents a powerful factor shaping career trajectories and economic outcomes achieved by individuals. However, a robust and growing body of evidence demonstrates a strong link between socioeconomic inequality and health outcomes. Work is a key…

  16. A Quality Inequality

    ERIC Educational Resources Information Center

    Sloyer, Clifford W.

    1975-01-01

    The inequality involving the arithmetic and geometric means is a powerful tool in dealing with applications of mathematics. It is very important in geometric programming. The article discusses this inequality and demonstrates two real world applications accessible to secondary teachers and students. (Author/KM)

  17. Schooling for Inequality.

    ERIC Educational Resources Information Center

    Smith, Dorothy E.

    2000-01-01

    Inequalities produced by the school system are an important topic for feminist thought and debate. Schools are an integral part of the institutional processes for the differential allocation of agency. They reproduce the social organization of inequality and exclusion at multiple levels. School systems are well-insulated from change initiatives…

  18. The Price of Inequality

    ERIC Educational Resources Information Center

    Jensen, Arthur R.

    1975-01-01

    An examination of the implications of attempting to reconcile philosophical beliefs concerning equality of opportunity with observed differences in equality of performance, which argues that there can be no real escape from inequality. Efforts to ignore, deny, or cope with the issue of group differences and group inequality must exact a price,…

  19. Growth and inequality

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2015-11-01

    How are growth and inequality related? Evidently, this question is of prime importance in the social sciences, as socioeconomic inequality is one of the major forces shaping the course of human history. Moreover, this question is of importance also in the physical sciences, as the notion of socioeconomic inequality can be applied to analyze physical growth. In this paper we consider general growth processes whose dynamics are governed by ordinary differential equations, and present a comprehensive inequality-based socioeconophysical study of their evolutions. From a social-sciences perspective, the results established describe the inequality that will be generated by different types of economic growth. From a physical-sciences perspective, the results established provide a socioeconomic classification of growth processes.

  20. Social inequalities and health inequity in Morocco

    PubMed Central

    Boutayeb, Abdesslam

    2006-01-01

    Background According to the last census, Morocco has a population approaching 30 million people. The country has made good progress in the control of preventable childhood diseases but social inequalities and health inequities remain major problems for the third millennium. Despite the progress achieved during the last decade, the country still ranks at the 125th place according to the Human Development Index. This unpleasant position is mainly explained by illiteracy, education and health indicators. Method Our study was based mainly on annual reports and regular publications released by the United Nations (UN), United Nations Development Programme (UNDP), World Health Organisation (WHO), The Moroccan Health Ministry and related papers published in international journals. Results and discussion As indicated by the last Arab Human Development Reports (AHDR 2002, AHDR 2003, AHDR 2004) and implicitly confirmed by the "National Initiative for Human Development" (NIHD) launched in May 2005 by the King of Morocco, many districts and shanty towns, urban or peri-urban, and a multitude of rural communes live in situations characterized by difficult access to basic social services of which education and health are examples. Conclusion Recent evidence showed that improved health is more than a consequence of development. It is a central input into economic and social development and poverty reduction. Serious initiatives for human development should consider the reduction of social inequalities and health inequities as a first priority. Otherwise, the eventual development achieved cannot be sustained. PMID:16522204

  1. Leggett-Garg inequalities

    NASA Astrophysics Data System (ADS)

    Emary, Clive; Lambert, Neill; Nori, Franco

    2014-01-01

    In contrast to the spatial Bell's inequalities which probe entanglement between spatially separated systems, the Leggett-Garg inequalities test the correlations of a single system measured at different times. Violation of a genuine Leggett-Garg test implies either the absence of a realistic description of the system or the impossibility of measuring the system without disturbing it. Quantum mechanics violates the inequalities on both accounts and the original motivation for these inequalities was as a test for quantum coherence in macroscopic systems. The last few years has seen a number of experimental tests and violations of these inequalities in a variety of microscopic systems such as superconducting qubits, nuclear spins, and photons. In this article, we provide an introduction to the Leggett-Garg inequalities and review these latest experimental developments. We discuss important topics such as the significance of the non-invasive measurability assumption, the clumsiness loophole, and the role of weak measurements. Also covered are some recent theoretical proposals for the application of Leggett-Garg inequalities in quantum transport, quantum biology and nano-mechanical systems.

  2. Temporal steering inequality

    NASA Astrophysics Data System (ADS)

    Chen, Yueh-Nan; Li, Che-Ming; Lambert, Neill; Chen, Shin-Liang; Ota, Yukihiro; Chen, Guang-Yin; Nori, Franco

    2014-03-01

    Quantum steering is the ability to remotely prepare different quantum states by using entangled pairs as a resource. Very recently, the concept of steering has been quantified with the use of inequalities, leading to substantial applications in quantum information and communication science. Here, we highlight that there exists a natural temporal analog of the steering inequality when considering measurements on a single object at different times. We give nontrivial operational meaning to violations of this temporal inequality by showing that it is connected to the security bound in the Bennett-Brassard 1984 protocol and thus may have applications in quantum communication.

  3. Constraint Handling in Transmission Network Expansion Planning

    NASA Astrophysics Data System (ADS)

    Mallipeddi, R.; Verma, Ashu; Suganthan, P. N.; Panigrahi, B. K.; Bijwe, P. R.

    Transmission network expansion planning (TNEP) is a very important and complex problem in power system. Recently, the use of metaheuristic techniques to solve TNEP is gaining more importance due to their effectiveness in handling the inequality constraints and discrete values over the conventional gradient based methods. Evolutionary algorithms (EAs) generally perform unconstrained search and require some additional mechanism to handle constraints. In EA literature, various constraint handling techniques have been proposed. However, to solve TNEP the penalty function approach is commonly used while the other constraint handling methods are untested. In this paper, we evaluate the performance of different constraint handling methods like Superiority of Feasible Solutions (SF), Self adaptive Penalty (SP),E-Constraint (EC), Stochastic Ranking (SR) and the ensemble of constraint handling techniques (ECHT) on TNEP. The potential of different constraint handling methods and their ensemble is evaluated using an IEEE 24 bus system with and without security constraints.

  4. Entanglement estimation from Bell inequality violation

    NASA Astrophysics Data System (ADS)

    Bartkiewicz, Karol; Horst, Bohdan; Lemr, Karel; Miranowicz, Adam

    2013-11-01

    It is well known that the violation of Bell's inequality in the form given by Clauser, Horne, Shimony, and Holt (CHSH) in two-qubit systems requires entanglement, but not vice versa, i.e., there are entangled states which do not violate the CHSH inequality. Here we compare some standard entanglement measures with violations of the CHSH inequality (as given by the Horodecki measure) for two-qubit states generated by Monte Carlo simulations. We describe states that have extremal entanglement according to the negativity, concurrence, and relative entropy of entanglement for a given value of the CHSH violation. We explicitly find these extremal states by applying the generalized method of Lagrange multipliers based on the Karush-Kuhn-Tucker conditions. The found minimal and maximal states define the range of entanglement accessible for any two-qubit states that violate the CHSH inequality by the same amount. We also find extremal states for the concurrence versus negativity by considering only such states which do not violate the CHSH inequality. Furthermore, we describe an experimentally efficient linear-optical method to determine the highest Horodecki degree of the CHSH violation for arbitrary mixed states of two polarization qubits. By assuming to have access simultaneously to two copies of the states, our method requires only six discrete measurement settings instead of nine settings, which are usually considered.

  5. Robust tracking control for an air-breathing hypersonic vehicle with input constraints

    NASA Astrophysics Data System (ADS)

    Gao, Gang; Wang, Jinzhi; Wang, Xianghua

    2014-12-01

    The focus of this paper is on the design and simulation of robust tracking control for an air-breathing hypersonic vehicle (AHV), which is affected by high nonlinearity, uncertain parameters and input constraints. The linearisation method is employed for the longitudinal AHV model about a specific trim condition, and then considering the additive uncertainties of three parameters, the linearised model is just in the form of affine parameter dependence. From this point, the linear parameter-varying method is applied to design the desired controller. The poles for the closed-loop system of the linearised model are placed into a desired vertical strip, and the quadratic stability of the closed-loop system is guaranteed. Input constraints of the AHV are addressed by additional linear matrix inequalities. Finally, the designed controller is evaluated on the nonlinear AHV model and simulation results demonstrate excellent tracking performance with good robustness.

  6. Multi-objective control of nonlinear boiler-turbine dynamics with actuator magnitude and rate constraints.

    PubMed

    Chen, Pang-Chia

    2013-01-01

    This paper investigates multi-objective controller design approaches for nonlinear boiler-turbine dynamics subject to actuator magnitude and rate constraints. System nonlinearity is handled by a suitable linear parameter varying system representation with drum pressure as the system varying parameter. Variation of the drum pressure is represented by suitable norm-bounded uncertainty and affine dependence on system matrices. Based on linear matrix inequality algorithms, the magnitude and rate constraints on the actuator and the deviations of fluid density and water level are formulated while the tracking abilities on the drum pressure and power output are optimized. Variation ranges of drum pressure and magnitude tracking commands are used as controller design parameters, determined according to the boiler-turbine's operation range. PMID:22959740

  7. Boole and Bell inequality

    SciTech Connect

    Michielsen, K.; De Raedt, H.; Hess, K.

    2011-03-28

    We discuss the relation between Bell's and Boole's inequality. We apply both to the analysis of measurement results in idealized Einstein-Podolsky-Rosen-Bohm experiments. We present a local realist model that violates Bell's and Boole's inequality due to the absence of Boole's one-to-one correspondence between the two-valued variables of the mathematical description and the two-valued measurement results.

  8. Generalized quasi variational inequalities

    SciTech Connect

    Noor, M.A.

    1996-12-31

    In this paper, we establish the equivalence between the generalized quasi variational inequalities and the generalized implicit Wiener-Hopf equations using essentially the projection technique. This equivalence is used to suggest and analyze a number of new iterative algorithms for solving generalized quasi variational inequalities and the related complementarity problems. The convergence criteria is also considered. The results proved in this paper represent a significant improvement and refinement of the previously known results.

  9. Global Oral Health Inequalities

    PubMed Central

    Garcia, I.; Tabak, L.A.

    2011-01-01

    Despite impressive worldwide improvements in oral health, inequalities in oral health status among and within countries remain a daunting public health challenge. Oral health inequalities arise from a complex web of health determinants, including social, behavioral, economic, genetic, environmental, and health system factors. Eliminating these inequalities cannot be accomplished in isolation of oral health from overall health, or without recognizing that oral health is influenced at multiple individual, family, community, and health systems levels. For several reasons, this is an opportune time for global efforts targeted at reducing oral health inequalities. Global health is increasingly viewed not just as a humanitarian obligation, but also as a vehicle for health diplomacy and part of the broader mission to reduce poverty, build stronger economies, and strengthen global security. Despite the global economic recession, there are trends that portend well for support of global health efforts: increased globalization of research and development, growing investment from private philanthropy, an absolute growth of spending in research and innovation, and an enhanced interest in global health among young people. More systematic and far-reaching efforts will be required to address oral health inequalities through the engagement of oral health funders and sponsors of research, with partners from multiple public and private sectors. The oral health community must be “at the table” with other health disciplines and create opportunities for eliminating inequalities through collaborations that can harness both the intellectual and financial resources of multiple sectors and institutions. PMID:21490232

  10. [Inequalities in health in Italy].

    PubMed

    Caiazzo, Antonio; Cardano, Mario; Cois, Ester; Costa, Giuseppe; Marinacci, Chiara; Spadea, Teresa; Vannoni, Francesca; Venturini, Lorenzo

    2004-01-01

    Socioeconomic inequality and its impact on health is a growing concern in the European public health debate. In many countries, the issue is moving away from description towards the identification of the determinants of inequalities and the development of policies explicitly aimed at reducing inequalities in health. In Italy, ten years after the publication of the first report on inequalities in health, this topic is seldom present on the agenda of public policy makers. The purpose of this report is to update the Italian profile of social variation in health and health care in order to stimulate the debate on ways to tackle inequalities in health that are preventable. In the first section of this book, the threefold objective is to describe the principal mechanisms involved in the generation of social inequalities in health (Introduction); to report Italian data on the distribution and magnitude of this phenomenon in the last decade; and to evaluate policies and interventions in both the social (chapter 1.9, Section I) and the health sector (chapter 2.3, Section I), which are potentially useful to reduce health inequalities. It is intended for anyone who is in a position to contribute t o decision-making that will benefit the health of communities. For this reason, chapters are organized by specific determinants of inequalities on which interentions may have an impact. The methodological approach in the second section focuses on the best methods to monitor social inequalities including recommendations on social indicators, sources of information and study models, based on European guidelines revised for the Italian situation. According to data from national and local studies, mortality increases linearly with social disadvantage for a wide range of indicators at both the individual (education, social class, income, quality of housing) and the geographical level (deprivation indexes computed at different levels of aggregation). This positive correlation is evident

  11. Observers for Systems with Nonlinearities Satisfying an Incremental Quadratic Inequality

    NASA Technical Reports Server (NTRS)

    Acikmese, Ahmet Behcet; Corless, Martin

    2004-01-01

    We consider the problem of state estimation for nonlinear time-varying systems whose nonlinearities satisfy an incremental quadratic inequality. These observer results unifies earlier results in the literature; and extend it to some additional classes of nonlinearities. Observers are presented which guarantee that the state estimation error exponentially converges to zero. Observer design involves solving linear matrix inequalities for the observer gain matrices. Results are illustrated by application to a simple model of an underwater.

  12. The Relationship between Income Inequality and Inequality in Schooling

    ERIC Educational Resources Information Center

    Mayer, Susan E.

    2010-01-01

    Children of affluent parents get more schooling than children of poor parents, which seems to imply that reducing income inequality would reduce inequality in schooling. Similarly, one of the best predictors of an individual's income is his educational attainment, which seems to imply that reducing inequality in schooling will reduce income…

  13. The demographics of inequality.

    PubMed

    Pestieau, P

    1989-01-01

    "This paper presents a survey of recent literature on the effects of demographic variables on economic inequality. First, a number of conceptual and methodological questions are raised and discussed. They pertain to what is meant by inequality, what the range of demographic variables is, and how variable and endogenous are the demographic variables most widely used. The paper then turns to a review of empirical works on the distributive incidence of the following demographic variables: baby boomers entering the job market, aging population, variable fertility and mortality rates, internal and external migrations, divorce and widowhood, and finally donations and bequests. It appears that a lot of caution is needed when assessing the incidence of any demographic variable changing the size of the population because in this case standard inequality measures yield conflicting signals." The geographical focus is on developed countries. PMID:12315947

  14. Trends in Global Gender Inequality

    ERIC Educational Resources Information Center

    Dorius, Shawn F.; Firebaugh, Glenn

    2010-01-01

    This study investigates trends in gender inequality throughout the world. Using data encompassing a large majority of the world's population, we examine trends in recent decades for key indicators of gender inequality in education, mortality, political representation and economic activity. We find that gender inequality is declining in virtually…

  15. Inequality from the Get Go.

    ERIC Educational Resources Information Center

    Bracey, Gerald W.

    2003-01-01

    Reviews two recent books on different aspects of socioeconomic-status-based inequalities in the school readiness of children entering kindergarten: Lee and Burkam's "Inequality at the Starting Gate" and Coley's "An Uneven Start: Indicators of Inequality in School Readiness." Also discusses "America's Children: Key National Indicators of Well-Being…

  16. Lorentz-invariant Bell's inequality

    SciTech Connect

    Kim, Won Tae; Son, Edwin J.

    2005-01-01

    We study Bell's inequality in relation to the Einstein-Podolsky-Rosen paradox in the relativistic regime. For this purpose, a relativistically covariant analysis is used in the calculation of the Bell's inequality, which results in the maximally violated Bell's inequality in any reference frame.

  17. Optimizing Inequality Constrained Priors in Bayesian Networks

    NASA Astrophysics Data System (ADS)

    Holmes, Dawn E.

    2005-11-01

    Intelligent systems based on Bayesian networks have been successful in medical diagnosis, finance and many other areas. Updating probabilities in Bayesian networks relies on algorithms that require complete causal information. Sensitivity analysis now strongly indicates that probabilities in Bayesian networks are not robust and this reinforces the view that a sound theoretical model for finding a minimally prejudiced estimate of the prior distribution is desirable. In this paper we are concerned with how to find the optimum prior distribution, given all and only the knowledge available. In particular, we show how to integrate prior knowledge expressed in terms of inequality constraints, into a Bayesian network based intelligent system.

  18. Gender Inequality at Work.

    ERIC Educational Resources Information Center

    Jacobs, Jerry A., Ed.

    These 14 papers address many dimensions of gender inequality at work. The empirical studies include examinations of original surveys, secondary analyses of large data sets, and historical reports assaying the significance of personal, family, and structural factors with regard to gender in the workplace. An introduction (Jacobs) sketches how sex…

  19. Racial Inequality in Education.

    ERIC Educational Resources Information Center

    Troyna, Barry, Ed.

    Contributors to this book are united in their commitment to combating racial inequality in education and in outlining the extent and manner in which racism and its associated practices have become embedded in the institutional and sociopolitical structures of the United Kingdom. The following chapters are included: (1) "A Conceptual Overview of…

  20. The Future in Inequality

    ERIC Educational Resources Information Center

    Melamed, David; North, Michael S.

    2010-01-01

    Recently an article in "Personality and Social Psychology Review" urged social psychologists to reacquire their "sociological imagination" and incorporate broader, structural factors in their work (Oishi, Kesebir, and Snyder 2009). Studies of social inequality in particular seem ripe for this kind of collaboration. Psychological investigations…

  1. Grouping for Inequity

    ERIC Educational Resources Information Center

    Macqueen, Suzanne Elizabeth

    2013-01-01

    The inequity of streaming as a method of organising classes was established by research conducted in the 1960s and 1970s. While the practice produces small advantages for limited groups of students, it hinders the academic and social advancement of the majority. Although streaming has declined, new forms of achievement grouping have emerged, with…

  2. Steps to defeat inequality.

    PubMed

    Cole, Elaine

    2016-06-15

    A team of nursing students has won a prestigious RCNi award for organising a conference aimed at reducing health inequalities affecting people with learning disabilities. The Learning Disability Awareness Network (LDAN) team was crowned winner of the RCNi Andrew Parker Student Nurse award 2016 at a ceremony held at London's Westminster Park Plaza on May 6. PMID:27305237

  3. How Colleges Perpetuate Inequality

    ERIC Educational Resources Information Center

    Sacks, Peter

    2007-01-01

    Colleges, once seen as beacons of egalitarian hope, are becoming bastions of wealth and privilege that perpetuate inequality. The chance of a low-income child obtaining a bachelor's degree has not budged in three decades: Just 6 percent of students from the lowest-income families earned a bachelor's degree by age 24 in 1970, and in 2002 still only…

  4. The Inequality Controversy

    ERIC Educational Resources Information Center

    Jones, Faustine C.

    1973-01-01

    Critically reviews the current combined writing of Moynihan, Glazer, Herrnstein, Armor, Banfield, Jensen and others, discussing historical perspectives on inequality, the idea of equality, access to schooling as a means toward equality, unequal economic opportunity, and misrepresentations of the adequacies of the Black family. (JM)

  5. Marginality and Triangle Inequality

    NASA Astrophysics Data System (ADS)

    Nánásiová, O. L̆ga; Valášková, L̆ubica

    2010-12-01

    In this paper we study conditions for the existence of a 3-dimensional s-map on a quantum logic under assumption that marginal s-maps are known. We show that the existence of such a 3-dimensional s-map depends on the triangle inequality of d-map, which on a Boolean algebra represents a measure of symmetric difference.

  6. Looking for symmetric Bell inequalities

    NASA Astrophysics Data System (ADS)

    Bancal, Jean-Daniel; Gisin, Nicolas; Pironio, Stefano

    2010-09-01

    Finding all Bell inequalities for a given number of parties, measurement settings and measurement outcomes is in general a computationally hard task. We show that all Bell inequalities which are symmetric under the exchange of parties can be found by examining a symmetrized polytope which is simpler than the full Bell polytope. As an illustration of our method, we generate 238 885 new Bell inequalities and 1085 new Svetlichny inequalities. We find, in particular, facet inequalities for Bell experiments involving two parties and two measurement settings that are not of the Collins-Gisin-Linden-Massar-Popescu type.

  7. Generalized Bell-inequality experiments and computation

    SciTech Connect

    Hoban, Matty J.; Wallman, Joel J.; Browne, Dan E.

    2011-12-15

    We consider general settings of Bell inequality experiments with many parties, where each party chooses from a finite number of measurement settings each with a finite number of outcomes. We investigate the constraints that Bell inequalities place upon the correlations possible in local hidden variable theories using a geometrical picture of correlations. We show that local hidden variable theories can be characterized in terms of limited computational expressiveness, which allows us to characterize families of Bell inequalities. The limited computational expressiveness for many settings (each with many outcomes) generalizes previous results about the many-party situation each with a choice of two possible measurements (each with two outcomes). Using this computational picture we present generalizations of the Popescu-Rohrlich nonlocal box for many parties and nonbinary inputs and outputs at each site. Finally, we comment on the effect of preprocessing on measurement data in our generalized setting and show that it becomes problematic outside of the binary setting, in that it allows local hidden variable theories to simulate maximally nonlocal correlations such as those of these generalized Popescu-Rohrlich nonlocal boxes.

  8. Tuning of power system controllers using symbolic eigensensitivity analysis and linear programming

    SciTech Connect

    Xu, L.; Ahmed-Zaid, S.

    1995-02-01

    In this paper, a systematic method for the tuning of multiple power system controllers using symbolic eigensensitivity analysis and linear programming is presented. The concept of eigenvalue sensitivity is used here to formulate the linear first-order variation of the real part of the dominant system eigenvalue as a symbolic function of controller parameters. This eigenvalue variation is minimized iteratively subject to linear equality and inequality constraints. All controller parameters are tuned correctly when the objective function meets the desired performance criteria. In this method, no special assumptions are made on the type of power devices and linear feedback controllers present in the system. The proposed method is illustrated with three examples of a single-machine system with a power system stabilizer and a controller for a thyristor-controlled series capacitor. The tested configurations are supplemented with nonlinear time-domain simulations validating the small-signal stability results.

  9. An algorithm for the solution of dynamic linear programs

    NASA Technical Reports Server (NTRS)

    Psiaki, Mark L.

    1989-01-01

    The algorithm's objective is to efficiently solve Dynamic Linear Programs (DLP) by taking advantage of their special staircase structure. This algorithm constitutes a stepping stone to an improved algorithm for solving Dynamic Quadratic Programs, which, in turn, would make the nonlinear programming method of Successive Quadratic Programs more practical for solving trajectory optimization problems. The ultimate goal is to being trajectory optimization solution speeds into the realm of real-time control. The algorithm exploits the staircase nature of the large constraint matrix of the equality-constrained DLPs encountered when solving inequality-constrained DLPs by an active set approach. A numerically-stable, staircase QL factorization of the staircase constraint matrix is carried out starting from its last rows and columns. The resulting recursion is like the time-varying Riccati equation from multi-stage LQR theory. The resulting factorization increases the efficiency of all of the typical LP solution operations over that of a dense matrix LP code. At the same time numerical stability is ensured. The algorithm also takes advantage of dynamic programming ideas about the cost-to-go by relaxing active pseudo constraints in a backwards sweeping process. This further decreases the cost per update of the LP rank-1 updating procedure, although it may result in more changes of the active set that if pseudo constraints were relaxed in a non-stagewise fashion. The usual stability of closed-loop Linear/Quadratic optimally-controlled systems, if it carries over to strictly linear cost functions, implies that the saving due to reduced factor update effort may outweigh the cost of an increased number of updates. An aerospace example is presented in which a ground-to-ground rocket's distance is maximized. This example demonstrates the applicability of this class of algorithms to aerospace guidance. It also sheds light on the efficacy of the proposed pseudo constraint relaxation

  10. Addressing Environmental Health Inequalities.

    PubMed

    Gouveia, Nelson

    2016-01-01

    Environmental health inequalities refer to health hazards disproportionately or unfairly distributed among the most vulnerable social groups, which are generally the most discriminated, poor populations and minorities affected by environmental risks. Although it has been known for a long time that health and disease are socially determined, only recently has this idea been incorporated into the conceptual and practical framework for the formulation of policies and strategies regarding health. In this Special Issue of the International Journal of Environmental Research and Public Health (IJERPH), "Addressing Environmental Health Inequalities-Proceedings from the ISEE Conference 2015", we incorporate nine papers that were presented at the 27th Conference of the International Society for Environmental Epidemiology (ISEE), held in Sao Paulo, Brazil, in 2015. This small collection of articles provides a brief overview of the different aspects of this topic. Addressing environmental health inequalities is important for the transformation of our reality and for changing the actual development model towards more just, democratic, and sustainable societies driven by another form of relationship between nature, economy, science, and politics. PMID:27618906

  11. Affine Isoperimetry and Information Theoretic Inequalities

    ERIC Educational Resources Information Center

    Lv, Songjun

    2012-01-01

    There are essential connections between the isoperimetric theory and information theoretic inequalities. In general, the Brunn-Minkowski inequality and the entropy power inequality, as well as the classical isoperimetric inequality and the classical entropy-moment inequality, turn out to be equivalent in some certain sense, respectively. Based on…

  12. Income inequality and mortality in metropolitan areas of the United States.

    PubMed Central

    Lynch, J W; Kaplan, G A; Pamuk, E R; Cohen, R D; Heck, K E; Balfour, J L; Yen, I H

    1998-01-01

    OBJECTIVES: This study examined associations between income inequality and mortality in 282 US metropolitan areas. METHODS: Income inequality measures were calculated from the 1990 US Census. Mortality was calculated from National Center for Health Statistics data and modeled with weighted linear regressions of the log age-adjusted rate. RESULTS: Excess mortality between metropolitan areas with high and low income inequality ranged from 64.7 to 95.8 deaths per 100,000 depending on the inequality measure. In age-specific analyses, income inequality was most evident for infant mortality and for mortality between ages 15 and 64. CONCLUSIONS: Higher income inequality is associated with increased mortality at all per capita income levels. Areas with high income inequality and low average income had excess mortality of 139.8 deaths per 100,000 compared with areas with low inequality and high income. The magnitude of this mortality difference is comparable to the combined loss of life from lung cancer, diabetes, motor vehicle crashes, human immunodeficiency virus (HIV) infection, suicide, and homicide in 1995. Given the mortality burden associated with income inequality, public and private sector initiatives to reduce economic inequalities should be a high priority. Images FIGURE 1 PMID:9663157

  13. Proof of the averaged null energy condition in a classical curved spacetime using a null-projected quantum inequality

    NASA Astrophysics Data System (ADS)

    Kontou, Eleni-Alexandra; Olum, Ken D.

    2015-12-01

    Quantum inequalities are constraints on how negative the weighted average of the renormalized stress-energy tensor of a quantum field can be. A null-projected quantum inequality can be used to prove the averaged null energy condition, which would then rule out exotic phenomena such as wormholes and time machines. In this work we derive such an inequality for a massless minimally coupled scalar field, working to first order of the Riemann tensor and its derivatives. We then use this inequality to prove the averaged null energy condition on achronal geodesics in a curved background that obeys the null convergence condition.

  14. Multisetting Bell inequality for qudits

    NASA Astrophysics Data System (ADS)

    Ji, Se-Wan; Lee, Jinhyoung; Lim, James; Nagata, Koji; Lee, Hai-Woong

    2008-11-01

    We propose a generalized Bell inequality for two three-dimensional systems with three settings in each local measurement. It is shown that this inequality is maximally violated if local measurements are configured to be mutually unbiased and a composite state is maximally entangled. This feature is similar to Clauser-Horne-Shimony-Holt inequality for two qubits but is in contrast with the two types of inequalities, Collins-Gisin-Linden-Massar-Popescu and Son-Lee-Kim, for high-dimensional systems. The generalization to aribitrary prime-dimensional systems is discussed.

  15. Unification of multiqubit polygamy inequalities

    NASA Astrophysics Data System (ADS)

    Kim, Jeong San

    2012-03-01

    I establish a unified view of polygamy of multiqubit entanglement. I first introduce a two-parameter generalization of the entanglement of assistance, namely, the unified entanglement of assistance for bipartite quantum states, and provide an analytic lower bound in two-qubit systems. I show a broad class of polygamy inequalities of multiqubit entanglement in terms of the unified entanglement of assistance that encapsulates all known multiqubit polygamy inequalities as special cases. I further show that this class of polygamy inequalities can be improved into tighter inequalities for three-qubit systems.

  16. Scaling effects on area-averaged fraction of vegetation cover derived using a linear mixture model with two-band spectral vegetation index constraints

    NASA Astrophysics Data System (ADS)

    Obata, Kenta; Huete, Alfredo R.

    2014-01-01

    This study investigated the mechanisms underlying the scaling effects that apply to a fraction of vegetation cover (FVC) estimates derived using two-band spectral vegetation index (VI) isoline-based linear mixture models (VI isoline-based LMM). The VIs included the normalized difference vegetation index, a soil-adjusted vegetation index, and a two-band enhanced vegetation index (EVI2). This study focused in part on the monotonicity of an area-averaged FVC estimate as a function of spatial resolution. The proof of monotonicity yielded measures of the intrinsic area-averaged FVC uncertainties due to scaling effects. The derived results demonstrate that a factor ξ, which was defined as a function of "true" and "estimated" endmember spectra of the vegetated and nonvegetated surfaces, was responsible for conveying monotonicity or nonmonotonicity. The monotonic FVC values displayed a uniform increasing or decreasing trend that was independent of the choice of the two-band VI. Conditions under which scaling effects were eliminated from the FVC were identified. Numerical simulations verifying the monotonicity and the practical utility of the scaling theory were evaluated using numerical experiments applied to Landsat7-Enhanced Thematic Mapper Plus (ETM+) data. The findings contribute to developing scale-invariant FVC estimation algorithms for multisensor and data continuity.

  17. New constraints on the 3D shear wave velocity structure of the upper mantle underneath Southern Scandinavia revealed from non-linear tomography

    NASA Astrophysics Data System (ADS)

    Wawerzinek, B.; Ritter, J. R. R.; Roy, C.

    2013-08-01

    We analyse travel times of shear waves, which were recorded at the MAGNUS network, to determine the 3D shear wave velocity (vS) structure underneath Southern Scandinavia. The travel time residuals are corrected for the known crustal structure of Southern Norway and weighted to account for data quality and pick uncertainties. The resulting residual pattern of subvertically incident waves is very uniform and simple. It shows delayed arrivals underneath Southern Norway compared to fast arrivals underneath the Oslo Graben and the Baltic Shield. The 3D upper mantle vS structure underneath the station network is determined by performing non-linear travel time tomography. As expected from the residual pattern the resulting tomographic model shows a simple and continuous vS perturbation pattern: a negative vS anomaly is visible underneath Southern Norway relative to the Baltic Shield in the east with a contrast of up to 4% vS and a sharp W-E dipping transition zone. Reconstruction tests reveal besides vertical smearing a good lateral reconstruction of the dipping vS transition zone and suggest that a deep-seated anomaly at 330-410 km depth is real and not an inversion artefact. The upper part of the reduced vS anomaly underneath Southern Norway (down to 250 km depth) might be due to an increase in lithospheric thickness from the Caledonian Southern Scandes in the west towards the Proterozoic Baltic Shield in Sweden in the east. The deeper-seated negative vS anomaly (330-410 km depth) could be caused by a temperature anomaly possibly combined with effects due to fluids or hydrous minerals. The determined simple 3D vS structure underneath Southern Scandinavia indicates that mantle processes might influence and contribute to a Neogene uplift of Southern Norway.

  18. [Inequities in access to information and inequities in health].

    PubMed

    Filho, Alberto Pellegrini

    2002-01-01

    This piece presents evidence that inequities in information are an important determinant of health inequities and that eliminating these inequities in access to information, especially by using new information and communication technologies (ICTs), could represent a significant advance in terms of guaranteeing the right to health for all. The piece reviews the most important international scientific research findings on the determinants of the health of populations, emphasizing the role of socioeconomic inequities and of deteriorating social capital as factors that worsen health conditions. It is noteworthy that Latin America has both socioeconomic inequities and major sectors of the population living in poverty. Among the fundamental strategies for overcoming the inequalities and the poverty are greater participation by the poor in civic life and the strengthening of social capital. The contribution that the new ICTs could make to these strategies is analyzed, and the Virtual Health Library (VHL) is discussed. Coordinated by the Latin American and Caribbean Center on Health Sciences Information (BIREME), the VHL is a contribution by the Pan American Health Organization that takes advantage of the potential of ICTs to democratize information and knowledge and consequently promote equity in health. The "digital gap" is discussed as something that can produce inequity itself and also increase other inequities, including ones in health. Prospects are discussed for overcoming this gap, emphasizing the role that governments and international organizations should play in order to expand access to the global public good that information for social development is. PMID:12162837

  19. Finite-time stochastic contractive boundedness of Markovian jump systems subject to input constraints.

    PubMed

    Cheng, Jun; Xiang, Huili; Wang, Hailing; Liu, Zhijun; Hou, Liyuan

    2016-01-01

    This paper studies the finite-time stochastic contractive boundedness problem for a class of Markovian jump linear systems subject to input constraints. First of all, by employing exogenous disturbance, two novel concepts, namely finite-time stochastic contractive stability (FTSCS) and finite-time stochastic contractive boundedness (FTSCB) are introduced. Secondly, a relaxation scheme for incomplete (i.e., partly known, unknown, and uncertain) transition probability descriptions is introduced. Then, two kinds of design methodology of observer-based controllers are proposed. All the design conditions are established by employing a set of linear matrix inequalities (LMIs). At last, numerical examples are given to demonstrate the effectiveness of the proposed approach. PMID:26596242

  20. On New Proofs of Fundamental Inequalities with Applications

    ERIC Educational Resources Information Center

    Ray, Partha

    2010-01-01

    By using the Cauchy-Schwarz inequality a new proof of several standard inequalities is given. A new proof of Young's inequality is given by using Holder's inequality. A new application of the above inequalities is included.

  1. Inequalities, Assessment and Computer Algebra

    ERIC Educational Resources Information Center

    Sangwin, Christopher J.

    2015-01-01

    The goal of this paper is to examine single variable real inequalities that arise as tutorial problems and to examine the extent to which current computer algebra systems (CAS) can (1) automatically solve such problems and (2) determine whether students' own answers to such problems are correct. We review how inequalities arise in…

  2. The Geography of Gender Inequality

    PubMed Central

    Fisher, Brendan; Naidoo, Robin

    2016-01-01

    Reducing gender inequality is a major policy concern worldwide, and one of the Sustainable Development Goals. However, our understanding of the magnitude and spatial distribution of gender inequality results either from limited-scale case studies or from national-level statistics. Here, we produce the first high resolution map of gender inequality by analyzing over 689,000 households in 47 countries. Across these countries, we find that male-headed households have, on average, 13% more asset wealth and 303% more land for agriculture than do female-headed households. However, this aggregate global result masks a high degree of spatial heterogeneity, with bands of both high inequality and high equality apparent in countries and regions of the world. Further, areas where inequality is highest when measured by land ownership generally are not the same areas that have high inequality as measured by asset wealth. Our metrics of gender inequality in land and wealth are not strongly correlated with existing metrics of poverty, development, and income inequality, and therefore provide new information to increase the understanding of one critical dimension of poverty across the globe. PMID:26930356

  3. Three Centuries of American Inequality.

    ERIC Educational Resources Information Center

    Lindert, Peter H.; Williamson, Jeffrey G.

    Income inequality in the United States displays considerable variance since the seventeenth century. There is no eternal constancy to the degree of inequality in total income, in labor earnings, or in income from conventional nonhuman wealth either before or after the effects of government taxes and spending. When all the necessary adjustments to…

  4. The Geography of Gender Inequality.

    PubMed

    Fisher, Brendan; Naidoo, Robin

    2016-01-01

    Reducing gender inequality is a major policy concern worldwide, and one of the Sustainable Development Goals. However, our understanding of the magnitude and spatial distribution of gender inequality results either from limited-scale case studies or from national-level statistics. Here, we produce the first high resolution map of gender inequality by analyzing over 689,000 households in 47 countries. Across these countries, we find that male-headed households have, on average, 13% more asset wealth and 303% more land for agriculture than do female-headed households. However, this aggregate global result masks a high degree of spatial heterogeneity, with bands of both high inequality and high equality apparent in countries and regions of the world. Further, areas where inequality is highest when measured by land ownership generally are not the same areas that have high inequality as measured by asset wealth. Our metrics of gender inequality in land and wealth are not strongly correlated with existing metrics of poverty, development, and income inequality, and therefore provide new information to increase the understanding of one critical dimension of poverty across the globe. PMID:26930356

  5. Universal patterns of inequality

    NASA Astrophysics Data System (ADS)

    Banerjee, Anand; Yakovenko, Victor M.

    2010-07-01

    Probability distributions of money, income and energy consumption per capita are studied for ensembles of economic agents. The principle of entropy maximization for partitioning of a limited resource gives exponential distributions for the investigated variables. A non-equilibrium difference of money temperatures between different systems generates net fluxes of money and population. To describe income distribution, a stochastic process with additive and multiplicative components is introduced. The resultant distribution interpolates between exponential at the low end and power law at the high end, in agreement with the empirical data for the USA. We show that the increase in income inequality in the USA originates primarily from the increase in the income fraction going to the upper tail, which now exceeds 20% of the total income. Analyzing the data from the World Resources Institute, we find that the distribution of energy consumption per capita around the world can be approximately described by the exponential function. Comparing the data for 1990, 2000 and 2005, we discuss the effect of globalization on the inequality of energy consumption.

  6. On moments-based Heisenberg inequalities

    NASA Astrophysics Data System (ADS)

    Zozor, Steeve; Portesi, Mariela; Sanchez-Moreno, Pablo; Dehesa, Jesus S.

    2011-03-01

    In this paper we revisit the quantitative formulation of the Heisenberg uncertainty principle. The primary version of this principle establishes the impossibility of refined simultaneous measurement of position x and momentum u for a (1-dimensional) quantum particle in terms of variances: <‖x‖2><‖u‖2>⩾1/4. Since this inequality applies provided each variance exists, some authors proposed entropic versions of this principle as an alternative (employing Shannon's or Rényi's entropies). As another alternative, we consider moments-based formulations and show that inequalities involving moments of orders other than 2 can be found. Our procedure is based on the Rényi entropic versions of the Heisenberg relation together with the search for the maximal entropy under statistical moments' constraints (<‖x‖a> and <‖u‖b>). Our result improves a relation proposed very recently by Dehesa et al.. [1] where the same approach was used but starting with the Shannon version of the entropic uncertainty relation. Furthermore, we show that when a =b, the best bound we can find with our approach coincides with that of Ref. [1] and, in addition, for a = b = 2 the variance-based Heisenberg relation is recovered. Finally, we illustrate our results in the cases of d-dimensional hydrogenic systems.

  7. Happiness Inequality: How Much Is Reasonable?

    ERIC Educational Resources Information Center

    Gandelman, Nestor; Porzecanski, Rafael

    2013-01-01

    We compute the Gini indexes for income, happiness and various simulated utility levels. Due to decreasing marginal utility of income, happiness inequality should be lower than income inequality. We find that happiness inequality is about half that of income inequality. To compute the utility levels we need to assume values for a key parameter that…

  8. Generalized convexity and inequalities

    NASA Astrophysics Data System (ADS)

    Anderson, G. D.; Vamanamurthy, M. K.; Vuorinen, M.

    2007-11-01

    Let and let be the family of all mean values of two numbers in (some examples are the arithmetic, geometric, and harmonic means). Given , we say that a function is (m1,m2)-convex if f(m1(x,y))[less-than-or-equals, slant]m2(f(x),f(y)) for all . The usual convexity is the special case when both mean values are arithmetic means. We study the dependence of (m1,m2)-convexity on m1 and m2 and give sufficient conditions for (m1,m2)-convexity of functions defined by Maclaurin series. The criteria involve the Maclaurin coefficients. Our results yield a class of new inequalities for several special functions such as the Gaussian hypergeometric function and a generalized Bessel function.

  9. Poverty and health sector inequalities.

    PubMed Central

    Wagstaff, Adam

    2002-01-01

    Poverty and ill-health are intertwined. Poor countries tend to have worse health outcomes than better-off countries. Within countries, poor people have worse health outcomes than better-off people. This association reflects causality running in both directions: poverty breeds ill-health, and ill-health keeps poor people poor. The evidence on inequalities in health between the poor and non-poor and on the consequences for impoverishment and income inequality associated with health care expenses is discussed in this article. An outline is given of what is known about the causes of inequalities and about the effectiveness of policies intended to combat them. It is argued that too little is known about the impacts of such policies, notwithstanding a wealth of measurement techniques and considerable evidence on the extent and causes of inequalities. PMID:11953787

  10. Penrose inequality and apparent horizons

    SciTech Connect

    Ben-Dov, Ishai

    2004-12-15

    A spherically symmetric spacetime is presented with an initial data set that is asymptotically flat, satisfies the dominant energy condition, and such that on this initial data M<{radical}(A/16{pi}), where M is the total mass and A is the area of the apparent horizon. This provides a counterexample to a commonly stated version of the Penrose inequality, though it does not contradict the true Penrose inequality.

  11. The Spread of Inequality

    PubMed Central

    Rogers, Deborah S.; Deshpande, Omkar; Feldman, Marcus W.

    2011-01-01

    The causes of socioeconomic inequality have been debated since the time of Plato. Many reasons for the development of stratification have been proposed, from the need for hierarchical control over large-scale irrigation systems to the accumulation of small differences in wealth over time via inheritance processes. However, none of these explains how unequal societies came to completely displace egalitarian cultural norms over time. Our study models demographic consequences associated with the unequal distribution of resources in stratified societies. Agent-based simulation results show that in constant environments, unequal access to resources can be demographically destabilizing, resulting in the outward migration and spread of such societies even when population size is relatively small. In variable environments, stratified societies spread more and are also better able to survive resource shortages by sequestering mortality in the lower classes. The predictions of our simulation are provided modest support by a range of existing empirical studies. In short, the fact that stratified societies today vastly outnumber egalitarian societies may not be due to the transformation of egalitarian norms and structures, but may instead reflect the more rapid migration of stratified societies and consequent conquest or displacement of egalitarian societies over time. PMID:21957457

  12. Malnutrition: another health inequality?

    PubMed

    Stratton, Rebecca J

    2007-11-01

    Malnutrition (undernutrition) is one of the many health inequalities facing governments in the 21st century. Malnutrition is a common condition affecting millions of individuals in the UK, particularly older adults, the sick and those cared for within the healthcare system. It costs the National Health Service > pound sterling 7.3 x 109 annually. New data highlight marked geographical differences in the prevalence of malnutrition across England and an inter-relationship between deprivation, malnutrition and poor outcome. As malnutrition is a largely treatable condition, prompt identification and effective prevention and treatment of this costly condition is imperative. Routine screening for malnutrition in high-risk groups (e.g. the elderly and those in areas with high deprivation) and within the healthcare system should be a priority, with screening linked to appropriate plans for the management of malnutrition. Use should be made of specialised interventions, including oral nutritional supplements and artificial nutrition, to aid recovery and improve outcome, with skilled health professionals, including dietitians, involved where possible. Equity of access to nutritional services and treatments for malnutrition needs to occur across the UK and, although complex and multi-factorial, the effects of deprivation and other relevant socio-economic and geographical factors should be addressed. Ultimately, as malnutrition is a public health problem, its identification and treatment must become a priority for governments, healthcare planners and professionals. PMID:17961273

  13. Inequality in paleorecords.

    PubMed

    Biondi, Franco; Qeadan, Fares

    2008-04-01

    Paleorecords provide information on past environmental variability, and help define ecological reference conditions by means of changes in their characteristics (accumulation rate, geochemical composition, density, etc.). A measure of temporal dissimilarity, which has traditionally been used in dendrochronology and is called "mean sensitivity," only focuses on first-order time-series lags. In this paper mean sensitivity was extended to all possible lags to derive a mean sensitivity function (MSF). The MSF is equivalent to a one-dimensional form of the paired relative madogram, a tool used in geostatistics to quantify spatial dependence. We then showed that the sum of madograms for all possible time-series lags is encapsulated by a single parameter, the Gini coefficient. This parameter has long been used by econometricians, social scientists, and ecologists as a synthetic, quantitative measure of inequality and diversity. Considering the connection between the MSF and the madogram, and the convenience of summarizing data heterogeneity with a single number, the Gini coefficient is therefore particularly appropriate for succinctly evaluating the diversity of paleorecords. An example of this application is provided by focusing on public domain dendrochronological data for the western conterminous United States. PMID:18481530

  14. A quasi-linear structure of the southern margin of Eurasia prior to the India-Asia collision: First paleomagnetic constraints from Upper Cretaceous volcanic rocks near the western syntaxis of Tibet

    NASA Astrophysics Data System (ADS)

    Yi, Zhiyu; Huang, Baochun; Yang, Liekun; Tang, Xiangde; Yan, Yonggang; Qiao, Qingqing; Zhao, Jie; Chen, Liwei

    2015-07-01

    We report the first combined geochronologic and paleomagnetic study of volcanic rocks from the Shiquanhe and Yare Basins at the westernmost Lhasa Terrane, which aims to provide an accurate constraint on the shape and paleoposition of the southern margin of Asia prior to the India-Asia collision. Three new 40Ar/39Ar ages of 92.5 ± 2.9 Ma, 92.4 ± 0.9 Ma, and 79.6 ± 0.7 Ma determined by fresh matrix or feldspar from lava flows suggest a Late Cretaceous age for the investigated units. Characteristic remanent magnetizations have been successfully isolated from 38 sites which pass positive fold and/or reversal, conglomerate tests and are hence interpreted as primary in origin. The two paleopoles obtained from Yare and Shiquanhe yield consistent paleolatitudes of 13.6°N ± 9.6°N and 14.2°N ± 2.7°N, respectively (for a reference site of 31.5°N, 80°E), indicating that the southern margin of Asia near the western syntaxis was located far south during the Late Cretaceous time. A reconstruction of the Lhasa Terrane in the frame of Eurasia with paleomagnetic data obtained from its western and eastern parts indicates that the southern margin of Eurasia probably had a quasi-linear orientation prior to the collision formerly trending approximately 315°E. This is compatible with the shape of the Neo-Tethys slab observed from seismic tomographic studies. Our findings provide a solid basis for evaluating Cenozoic crustal shortening in the Asian interior and the size of Greater India near the western syntaxis.

  15. Bayesian Evaluation of Inequality-Constrained Hypotheses in SEM Models Using M"plus"

    ERIC Educational Resources Information Center

    van de Schoot, Rens; Hoijtink, Herbert; Hallquist, Michael N.; Boelen, Paul A.

    2012-01-01

    Researchers in the behavioral and social sciences often have expectations that can be expressed in the form of inequality constraints among the parameters of a structural equation model resulting in an informative hypothesis. The questions they would like an answer to are "Is the hypothesis Correct" or "Is the hypothesis incorrect?" We demonstrate…

  16. The Interplay between socioeconomic inequalities and clinical oral health.

    PubMed

    Steele, J; Shen, J; Tsakos, G; Fuller, E; Morris, S; Watt, R; Guarnizo-Herreño, C; Wildman, J

    2015-01-01

    Oral health inequalities associated with socioeconomic status are widely observed but may depend on the way that both oral health and socioeconomic status are measured. Our aim was to investigate inequalities using diverse indicators of oral health and 4 socioeconomic determinants, in the context of age and cohort. Multiple linear or logistic regressions were estimated for 7 oral health measures representing very different outcomes (2 caries prevalence measures, decayed/missing/filled teeth, 6-mm pockets, number of teeth, anterior spaces, and excellent oral health) against 4 socioeconomic measures (income, education, Index of Multiple Deprivation, and occupational social class) for adults aged ≥21 y in the 2009 UK Adult Dental Health Survey data set. Confounders were adjusted and marginal effects calculated. The results showed highly variable relationships for the different combinations of variables and that age group was critical, with different relationships at different ages. There were significant income inequalities in caries prevalence in the youngest age group, marginal effects of 0.10 to 0.18, representing a 10- to 18-percentage point increase in the probability of caries between the wealthiest and every other quintile, but there was not a clear gradient across the quintiles. With number of teeth as an outcome, there were significant income gradients after adjustment in older groups, up to 4.5 teeth (95% confidence interval, 2.2-6.8) between richest and poorest but none for the younger groups. For periodontal disease, income inequalities were mediated by other socioeconomic variables and smoking, while for anterior spaces, the relationships were age dependent and complex. In conclusion, oral health inequalities manifest in different ways in different age groups, representing age and cohort effects. Income sometimes has an independent relationship, but education and area of residence are also contributory. Appropriate choices of measures in relation to age

  17. Four-dimensional electrical conductivity monitoring of stage-driven river water intrusion: Accounting for water table effects using a transient mesh boundary and conditional inversion constraints

    SciTech Connect

    Johnson, Timothy C.; Versteeg, Roelof; Thomle, Jonathan N.; Hammond, Glenn E.; Chen, Xingyuan; Zachara, John M.

    2015-08-01

    This paper describes and demonstrates two methods of providing a-priori information to a surface-based time-lapse three-dimensional electrical resistivity tomography (ERT) problem for monitoring stage-driven river bank storage along the Columbia River in the state of Washington, USA. First, a transient warping mesh boundary is implemented that conforms to the known location of the water table boundary through time, thereby enabling the inversion to place a sharp bulk-conductivity contrast at that boundary without penalty. Second, because river water specific conductance is less than groundwater specific conductance, a non-linear inequality constraint is used to allow only negative transient changes in bulk conductivity to occur within the saturated zone during periods of elevated river stage with respect to baseline conditions. Whereas time-lapse imaging results using traditional smoothness constraints are unable to delineate river bank storage, the water table and inequality constraints provide the inversion with the additional information necessary to resolve the spatial extent of river water intrusion through time. A surface based ERT array of 352 electrodes was used to autonomously produce four images per day of changes in bulk conductivity associated with river water intrusion over an area of approximately 300 m2 from April through October of 2013. Results are validated by comparing changes in bulk conductivity time series with corresponding changes in fluid specific conductance at several inland monitoring wells.

  18. The sociogeometry of inequality: Part I

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2015-05-01

    The study of socioeconomic inequality is of prime economic and social importance, and the key quantitative gauges of socioeconomic inequality are Lorenz curves and inequality indices-the most notable of the latter being the popular Gini index. In this series of papers we present a sociogeometric framework to the study of socioeconomic inequality. In this part we shift from the notion of Lorenz curves to the notion of Lorenz sets, define inequality indices in terms of Lorenz sets, and introduce and explore a collection of distance-based and width-based inequality indices stemming from the geometry of Lorenz sets. In particular, three principle diameters of Lorenz sets are established as meaningful quantitative gauges of socioeconomic inequality-thus indeed providing a geometric quantification of socioeconomic inequality.

  19. STRUCTURAL RACISM AND HEALTH INEQUITIES

    PubMed Central

    Gee, Gilbert C.; Ford, Chandra L.

    2014-01-01

    Racial minorities bear a disproportionate burden of morbidity and mortality. These inequities might be explained by racism, given the fact that racism has restricted the lives of racial minorities and immigrants throughout history. Recent studies have documented that individuals who report experiencing racism have greater rates of illnesses. While this body of research has been invaluable in advancing knowledge on health inequities, it still locates the experiences of racism at the individual level. Yet, the health of social groups is likely most strongly affected by structural, rather than individual, phenomena. The structural forms of racism and their relationship to health inequities remain under-studied. This article reviews several ways of conceptualizing structural racism, with a focus on social segregation, immigration policy, and intergenerational effects. Studies of disparities should more seriously consider the multiple dimensions of structural racism as fundamental causes of health disparities. PMID:25632292

  20. Bell inequalities with communication assistance

    NASA Astrophysics Data System (ADS)

    Maxwell, Katherine; Chitambar, Eric

    2014-04-01

    In this paper, we consider the possible correlations between two parties using local machines and shared randomness with an additional amount of classical communication. This is a continuation of the work initiated by Bacon and Toner [Phys. Rev. Lett. 90, 157904 (2003), 10.1103/PhysRevLett.90.157904] who characterized the correlation polytope for 2×2 measurement settings with binary outcomes plus one bit of communication. Here, we derive a complete set of Bell inequalities for 3×2 measurement settings and a shared bit of communication. When the communication direction is fixed, nine Bell inequalities characterize the correlation polytope, whereas when the communication direction is bidirectional, 143 inequalities describe the correlations. We then prove a tight lower bound on the amount of communication needed to simulate all no-signaling correlations for a given number of measurement settings.

  1. Educational inequality in the occurrence of abdominal obesity: Pró-Saúde Study

    PubMed Central

    Alves, Ronaldo Fernandes Santos; Faerstein, Eduardo

    2015-01-01

    OBJECTIVE To estimate the degree of educational inequality in the occurrence of abdominal obesity in a population of non-faculty civil servants at university campi. METHODS In this cross-sectional study, we used data from 3,117 subjects of both genders aged 24 to 65-years old, regarding the baseline of Pró-Saúde Study, 1999-2001. Abdominal obesity was defined according to abdominal circumference thresholds of 88 cm for women and 102 cm for men. A multi-dimensional, self-administered questionnaire was used to evaluate education levels and demographic variables. Slope and relative indices of inequality, and Chi-squared test for linear trend were used in the data analysis. All analyses were stratified by genders, and the indices of inequality were standardized by age. RESULTS Abdominal obesity was the most prevalent among women (43.5%; 95%CI 41.2;45.9), as compared to men (24.3%; 95%CI 22.1;26.7), in all educational strata and age ranges. The association between education levels and abdominal obesity was an inverse one among women (p < 0.001); it was not statistically significant among men (p = 0.436). The educational inequality regarding abdominal obesity in the female population, in absolute terms (slope index of inequality), was 24.0% (95%CI 15.5;32.6). In relative terms (relative index of inequality), it was 2.8 (95%CI 1.9;4.1), after the age adjustment. CONCLUSIONS Gender inequality in the prevalence of abdominal obesity increases with older age and lower education. The slope and relative indices of inequality summarize the strictly monotonous trend between education levels and abdominal obesity, and it described educational inequality regarding abdominal obesity among women. Such indices provide relevant quantitative estimates for monitoring abdominal obesity and dealing with health inequalities. PMID:26465669

  2. Baryon-Meson Mass Inequality

    NASA Astrophysics Data System (ADS)

    Nussinov, S.

    1983-12-01

    It is suggested that the inequality mB>32mM is a rigorous result in quantum chromodynamics. The analog for a (q1...qN) baryon in SU(N) is mB>(12N)mM. The inequality is proved for weak coupling and a version of the strong-coupling expansion where a separation Hq1q2q3=H12+H23+H31 of the problem can be achieved. Implications for quantum chromodynamics and composite models are briefly discussed.

  3. Measures of Inequality: Application to Happiness in Nations.

    PubMed

    Kalmijn, W M; Arends, L R

    2010-10-01

    What is a good measure for happiness inequality? In the context of this question, we have developed an approach in which individual happiness values in a sample are considered as elements of a set and inequality as a binary relation on that set. The total number of inequality relations, each weighed by the distance on the scale of measurement between the pair partners, has been adopted as an indicator for the inequality of the distribution as a whole. For models in which the happiness occurs as a continuous latent variable, an analogous approach has been developed on the basis of differentials. In principle, this fundamental approach results in a (zero) minimum value, and, more importantly, also in a maximum value. In the case where happiness is measured using a k-points scale, the maximum inequality is obtained if all ½N sample members select the lowest possible rating (Eq. 1) and the other ½N the highest possible one (k). This finding even applies to the truly ordinal case, i.e., if the distances between the successive ratings on the scale are unknown. It is, however, impossible to quantify the inequality of some measured sample distribution, unless all distances of the k categories of the scale of measurement are known or at least estimated, either on an empirical basis or on the basis of assumptions. In general, the numerical application of the method to continuous distributions is very complicated. An exploration on the basis of a relatively simple model with a linear probability density function suggests that the inequality of a beta probability distribution with shape parameters a and b increases as the value of these parameters decreases. A contour plot, obtained by numerical integration, demonstrates this relationship in a quantitative way. This approach is applicable to judge the aptness of common statistics of dispersion, among which the standard deviation and the Gini coefficient. The former is shown to be more appropriate than the latter for

  4. Remainder terms for some quantum entropy inequalities

    SciTech Connect

    Carlen, Eric A.; Lieb, Elliott H.

    2014-04-15

    We consider three von Neumann entropy inequalities: subadditivity; Pinsker's inequality for relative entropy; and the monotonicity of relative entropy. For these we state conditions for equality, and we prove some new error bounds away from equality, including an improved version of Pinsker's inequality.

  5. Urban Inequality. NBER Working Paper No. 14419

    ERIC Educational Resources Information Center

    Glaeser, Edward L.; Resseger, Matthew G.; Tobio, Kristina

    2008-01-01

    What impact does inequality have on metropolitan areas? Crime rates are higher in places with more inequality, and people in unequal cities are more likely to say that they are unhappy. There is also a negative association between local inequality and the growth of both income and population, once we control for the initial distribution of skills.…

  6. Declaring Bankruptcy on Educational Inequity

    ERIC Educational Resources Information Center

    Bass, Lisa; Gerstl-Pepin, Cynthia

    2011-01-01

    The authors consider Ladson-Billings' (2006) charge to reframe the way the "achievement gap" is viewed, and put forth the metaphor of "bankruptcy" as a way to acknowledge the educational debt and educational inequity and move towards debt forgiveness in public education. Specifically, the bankruptcy metaphor is used to examine the debt embedded in…

  7. Racial Inequity in Special Education.

    ERIC Educational Resources Information Center

    Losen, Daniel J., Ed.; Orfield, Gary, Ed.

    This collection of papers discusses issues related to the overidentification of minority students in special education. After a "Foreword" (Senator James M. Jeffords) and an introduction, "Racial Inequality in Special Education" (Daniel J. Losen and Gary Orfield), 11 chapters include: (1) "Community and School Predictors…

  8. Voice, Schooling, Inequality, and Scale

    ERIC Educational Resources Information Center

    Collins, James

    2013-01-01

    The rich studies in this collection show that the investigation of voice requires analysis of "recognition" across layered spatial-temporal and sociolinguistic scales. I argue that the concepts of voice, recognition, and scale provide insight into contemporary educational inequality and that their study benefits, in turn, from paying attention to…

  9. Retirement Patterns and Income Inequality

    ERIC Educational Resources Information Center

    Fasang, Anette Eva

    2012-01-01

    How do social policies shape life courses, and which consequences do different life course patterns hold for individuals? This article engages the example of retirement in Germany and Britain to analyze life course patterns and their consequences for income inequality. Sequence analysis is used to measure retirement trajectories. The liberal…

  10. Environmental Racial Inequality in Detroit

    ERIC Educational Resources Information Center

    Downey, Liam

    2006-01-01

    This study uses industrial pollution data from the Environmental Protection Agency's Toxics Release Inventory (TRI) and tract-level demographic data from the 2000 U.S. census to determine whether environmental racial inequality existed in the Detroit metropolitan area in the year 2000. This study differs from prior environmental inequality…

  11. The sociogeometry of inequality: Part II

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2015-05-01

    The study of socioeconomic inequality is of prime economic and social importance, and the key quantitative gauges of socioeconomic inequality are Lorenz curves and inequality indices - the most notable of the latter being the popular Gini index. In this series of papers we present a sociogeometric framework to the study of socioeconomic inequality. In this part we focus on the gap between the rich and the poor, which is quantified by gauges termed disparity curves. We shift from disparity curves to disparity sets, define inequality indices in terms of disparity sets, and introduce and explore a collection of distance-based and width-based inequality indices stemming from the geometry of disparity sets. We conclude with mean-absolute-deviation (MAD) representations of the inequality indices established in this series of papers, and with a comparison of these indices to the popular Gini index.

  12. Stabilizer information inequalities from phase space distributions

    NASA Astrophysics Data System (ADS)

    Gross, David; Walter, Michael

    2013-08-01

    The Shannon entropy of a collection of random variables is subject to a number of constraints, the best-known examples being monotonicity and strong subadditivity. It remains an open question to decide which of these "laws of information theory" are also respected by the von Neumann entropy of many-body quantum states. In this article, we consider a toy version of this difficult problem by analyzing the von Neumann entropy of stabilizer states. We find that the von Neumann entropy of stabilizer states satisfies all balanced information inequalities that hold in the classical case. Our argument is built on the fact that stabilizer states have a classical model, provided by the discrete Wigner function: The phase-space entropy of the Wigner function corresponds directly to the von Neumann entropy of the state, which allows us to reduce to the classical case. Our result has a natural counterpart for multi-mode Gaussian states, which sheds some light on the general properties of the construction. We also discuss the relation of our results to recent work by Linden, Ruskai, and Winter ["The quantum entropy cone of stabiliser states," e-print arXiv:1302.5453].

  13. Quantum inequality restrictions on negative energy densities in curved spacetimes

    NASA Astrophysics Data System (ADS)

    Pfenning, Michael John

    1998-10-01

    In quantum field theory, there exist states in which the expectation value of the energy density for a quantized field is negative. These negative energy densities lead to several problems such as the failure of the classical energy conditions, the production of closed timelike curves and faster than light travel, violations of the second law of thermodynamics, and the possible production of naked singularities. Although quantum field theory introduces negative energies, it also provides constraints in the form of quantum inequalities (QI's). These uncertainty principle- type relations limit the magnitude and duration of any negative energy. We derive a general form of the QI on the energy density for both the quantized scalar and electromagnetic fields in static curved spacetimes. In the case of the scalar field, the QI can be written as the Euclidean wave operator acting on the Euclidean Green's function. Additionally, a small distance expansion on the Green's function is used to derive the QI in the short sampling time limit. It is found that the QI in this limit reduces to the flat space form with subdominant correction terms which depend on the spacetime geometry. Several example spacetimes are studied in which exact forms of the QI's can be found. These include the three- and four-dimensional static Robertson-Walker spacetimes, flat space with perfectly reflecting mirrors, Rindler and static de Sitter space, and the spacetime outside a black hole. In all of the above cases, we find that the quantum inequalities give a lower limit on how much negative energy may be observed relative to the vacuum energy density of the spacetime. For the particular case of the black hole, it is found that the quantum inequality on the energy density is measured relative to the Boulware vacuum. Finally, the application of the quantum inequalities to the Alcubierre warp drive spacetime leads to strict constraints on the thickness of the negative energy region needed to maintain

  14. Magnetotail dynamics under isobaric constraints

    NASA Technical Reports Server (NTRS)

    Birn, Joachim; Schindler, Karl; Janicke, Lutz; Hesse, Michael

    1994-01-01

    Using linear theory and nonlinear MHD simulations, we investigate the resistive and ideal MHD stability of two-dimensional plasma configurations under the isobaric constraint dP/dt = 0, which in ideal MHD is equivalent to conserving the pressure function P = P(A), where A denotes the magnetic flux. This constraint is satisfied for incompressible modes, such as Alfven waves, and for systems undergoing energy losses. The linear stability analysis leads to a Schroedinger equation, which can be investigated by standard quantum mechanics procedures. We present an application to a typical stretched magnetotail configuration. For a one-dimensional sheet equilibrium characteristic properties of tearing instability are rediscovered. However, the maximum growth rate scales with the 1/7 power of the resistivity, which implies much faster growth than for the standard tearing mode (assuming that the resistivity is small). The same basic eigen-mode is found also for weakly two-dimensional equilibria, even in the ideal MHD limit. In this case the growth rate scales with the 1/4 power of the normal magnetic field. The results of the linear stability analysis are confirmed qualitatively by nonlinear dynamic MHD simulations. These results suggest the interesting possibility that substorm onset, or the thinning in the late growth phase, is caused by the release of a thermodynamic constraint without the (immediate) necessity of releasing the ideal MHD constraint. In the nonlinear regime the resistive and ideal developments differ in that the ideal mode does not lead to neutral line formation without the further release of the ideal MHD constraint; instead a thin current sheet forms. The isobaric constraint is critically discussed. Under perhaps more realistic adiabatic conditions the ideal mode appears to be stable but could be driven by external perturbations and thus generate the thin current sheet in the late growth phase, before a nonideal instability sets in.

  15. INEQUITY IN THE FACE OF DEATH.

    PubMed

    García-Gómez, Pilar; Schokkaert, Erik; Van Ourti, Tom; Bago d'Uva, Teresa

    2014-07-30

    We apply the theory of inequality of opportunity to the measurement of inequity in mortality. Using a rich data set linking records of mortality and health events to survey data on lifestyles for the Netherlands (1998-2007), we test the sensitivity of estimated inequity to different normative choices and conclude that the location of the responsibility cut is of vital importance. Traditional measures of inequity (such as socioeconomic and regional inequalities) only capture part of more comprehensive notions of unfairness. We show that distinguishing between different routes via which variables might be associated to mortality is essential to the application of different normative positions. Using the fairness gap (direct unfairness), measured inequity according to our implementation of the 'control' and 'preference' approaches ranges between 0.0229 and 0.0239 (0.0102-0.0218), while regional and socioeconomic inequalities are smaller than 0.0020 (0.0001). The usual practice of standardizing for age and gender has large effects on measured inequity. Finally, we use our model to measure inequity in simulated counterfactual situations. While it is a big challenge to identify all causal relationships involved in this empirical context, this does not affect our main conclusions regarding the importance of normative choices in the measurement of inequity. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25073459

  16. On measuring inequalities in health.

    PubMed Central

    Wolfson, M.; Rowe, G.

    2001-01-01

    In a recent series of papers, Murray et al. have put forward a number of important ideas regarding the measurement of inequalities in health. In this paper we agree with some of these ideas but draw attention to one key aspect of their approach--measuring inequalities on the basis of small area data--which is flawed. A numerical example is presented to illustrate the problem. An alternative approach drawing on longitudinal data is outlined, which preserves and enhances the most desirable aspects of their proposal. These include the use of a life course perspective, and the consideration of non-fatal health outcomes as well as the more usual information on mortality patterns. PMID:11436478

  17. [Social inequalities in maternal health].

    PubMed

    Azria, E; Stewart, Z; Gonthier, C; Estellat, C; Deneux-Tharaux, C

    2015-10-01

    Although medical literature on social inequalities in perinatal health is qualitatively heterogeneous, it is quantitatively important and reveals the existence of a social gradient in terms of perinatal risk. However, published data regarding maternal health, if also qualitatively heterogeneous, are relatively less numerous. Nevertheless, it appears that social inequalities also exist concerning severe maternal morbidity as well as maternal mortality. Analyses are still insufficient to understand the mechanisms involved and explain how the various dimensions of the women social condition interact with maternal health indicators. Inadequate prenatal care and suboptimal obstetric care may be intermediary factors, as they are related to both social status and maternal outcomes, in terms of maternal morbidity, its worsening or progression, and maternal mortality. PMID:26433316

  18. Inequalities of Income and Inequalities of Longevity: A Cross-Country Study

    PubMed Central

    Plümper, Thomas

    2016-01-01

    Objectives. We examined the effects of market income inequality (income inequality before taxes and transfers) and income redistribution via taxes and transfers on inequality in longevity. Methods. We used life tables to compute Gini coefficients of longevity inequality for all individuals and for individuals who survived to at least 10 years of age. We regressed longevity inequality on market income inequality and income redistribution, and we controlled for potential confounders, in a cross-sectional time-series sample of up to 28 predominantly Western developed countries and up to 37 years (1974–2011). Results. Income inequality before taxes and transfers was positively associated with inequality in the number of years lived; income redistribution (the difference between market income inequality and income inequality after taxes and transfers were accounted for) was negatively associated with longevity inequality. Conclusions. To the extent that our estimated effects derived from observational data are causal, governments can reduce longevity inequality not only via public health policies, but also via their influence on market income inequality and the redistribution of incomes from the relatively rich to the relatively poor. PMID:26562120

  19. Inequalities for the quantum privacy

    NASA Astrophysics Data System (ADS)

    Trindade, M. A. S.; Pinto, E.

    2016-02-01

    In this work, we investigate the asymptotic behavior related to the quantum privacy for multipartite systems. In this context, an inequality for quantum privacy was obtained by exploiting of quantum entropy properties. Subsequently, we derive a lower limit for the quantum privacy through the entanglement fidelity. In particular, we show that there is an interval where an increase in entanglement fidelity implies a decrease in quantum privacy.

  20. [Globalization, inequity and Chagas disease].

    PubMed

    Dias, João Carlos Pinto

    2007-01-01

    Chagas disease (American trypanosomiasis) bears a close relationship to multiple social and political aspects involving issues of globalization and inequity. Such relations concern the process of disease production and control in parallel with medical management. Despite the poverty in Latin America and various problems related to inequities and globalization, Chagas disease has been controlled in several areas, a fact that reinforces the countries' self-reliance. Several problems and challenges related to the disease can be expected in the future, mainly concerning medical care for already infected individuals and the sustainability of effective epidemiological surveillance. Both points depend heavily on improved performance by the national health systems, principally in terms of their efficiency and their capacity to overcome inequity. A particularly important role has been attributed to the Latin American scientific and academic community in the implementation and sustainability of efficient control policies. Control activities have now evolved towards internationally shared initiatives, a major new stride forward in the region's political context. PMID:17308713

  1. Climate policies under wealth inequality

    PubMed Central

    Vasconcelos, Vítor V.; Santos, Francisco C.; Pacheco, Jorge M.; Levin, Simon A.

    2014-01-01

    Taming the planet’s climate requires cooperation. Previous failures to reach consensus in climate summits have been attributed, among other factors, to conflicting policies between rich and poor countries, which disagree on the implementation of mitigation measures. Here we implement wealth inequality in a threshold public goods dilemma of cooperation in which players also face the risk of potential future losses. We consider a population exhibiting an asymmetric distribution of rich and poor players that reflects the present-day status of nations and study the behavioral interplay between rich and poor in time, regarding their willingness to cooperate. Individuals are also allowed to exhibit a variable degree of homophily, which acts to limit those that constitute one’s sphere of influence. Under the premises of our model, and in the absence of homophily, comparison between scenarios with wealth inequality and without wealth inequality shows that the former leads to more global cooperation than the latter. Furthermore, we find that the rich generally contribute more than the poor and will often compensate for the lower contribution of the latter. Contributions from the poor, which are crucial to overcome the climate change dilemma, are shown to be very sensitive to homophily, which, if prevalent, can lead to a collapse of their overall contribution. In such cases, however, we also find that obstinate cooperative behavior by a few poor may largely compensate for homophilic behavior. PMID:24469806

  2. Sparse linear programming subprogram

    SciTech Connect

    Hanson, R.J.; Hiebert, K.L.

    1981-12-01

    This report describes a subprogram, SPLP(), for solving linear programming problems. The package of subprogram units comprising SPLP() is written in Fortran 77. The subprogram SPLP() is intended for problems involving at most a few thousand constraints and variables. The subprograms are written to take advantage of sparsity in the constraint matrix. A very general problem statement is accepted by SPLP(). It allows upper, lower, or no bounds on the variables. Both the primal and dual solutions are returned as output parameters. The package has many optional features. Among them is the ability to save partial results and then use them to continue the computation at a later time.

  3. On a (β, q)-generalized Fisher information and inequalities involving q-Gaussian distributions

    NASA Astrophysics Data System (ADS)

    Bercher, J.-F.

    2012-06-01

    In the present paper, we would like to draw attention to a possible generalized Fisher information that fits well in the formalism of nonextensive thermostatistics. This generalized Fisher information is defined for densities on {R}n. Just as the maximum Rényi or Tsallis entropy subject to an elliptic moment constraint is a generalized q-Gaussian, we show that the minimization of the generalized Fisher information also leads a generalized q-Gaussian. This yields a generalized Cramér-Rao inequality. In addition, we show that the generalized Fisher information naturally pops up in a simple inequality that links the generalized entropies, the generalized Fisher information, and an elliptic moment. Finally, we give an extended Stam inequality. In this series of results, the extremal functions are the generalized q-Gaussians. Thus, these results complement the classical characterization of the generalized q-Gaussian and introduce a generalized Fisher information as a new information measure in nonextensive thermostatistics.

  4. Linear game non-contextuality and Bell inequalities—a graph-theoretic approach

    NASA Astrophysics Data System (ADS)

    Rosicka, M.; Ramanathan, R.; Gnaciński, P.; Horodecki, K.; Horodecki, M.; Horodecki, P.; Severini, S.

    2016-04-01

    We study the classical and quantum values of a class of one- and two-party unique games, that generalizes the well-known XOR games to the case of non-binary outcomes. In the bipartite case the generalized XOR (XOR-d) games we study are a subclass of the well-known linear games. We introduce a ‘constraint graph’ associated to such a game, with the constraints defining the game represented by an edge-coloring of the graph. We use the graph-theoretic characterization to relate the task of finding equivalent games to the notion of signed graphs and switching equivalence from graph theory. We relate the problem of computing the classical value of single-party anti-correlation XOR games to finding the edge bipartization number of a graph, which is known to be MaxSNP hard, and connect the computation of the classical value of XOR-d games to the identification of specific cycles in the graph. We construct an orthogonality graph of the game from the constraint graph and study its Lovász theta number as a general upper bound on the quantum value even in the case of single-party contextual XOR-d games. XOR-d games possess appealing properties for use in device-independent applications such as randomness of the local correlated outcomes in the optimal quantum strategy. We study the possibility of obtaining quantum algebraic violation of these games, and show that no finite XOR-d game possesses the property of pseudo-telepathy leaving the frequently used chained Bell inequalities as the natural candidates for such applications. We also show this lack of pseudo-telepathy for multi-party XOR-type inequalities involving two-body correlation functions.

  5. Unbounded Violation of Quantum Steering Inequalities

    NASA Astrophysics Data System (ADS)

    Marciniak, M.; Rutkowski, A.; Yin, Z.; Horodecki, M.; Horodecki, R.

    2015-10-01

    We construct steering inequalities that exhibit unbounded violation. The concept was to exploit the relationship between steering violation and the uncertainty relation. To this end, we apply mutually unbiased bases and anticommuting observables, known to exhibit the strongest uncertainty. In both cases, we are able to procure unbounded violations. Our approach is much more constructive and transparent than the operator space theory approach employed to obtain large violation of Bell inequalities. Importantly, using anticommuting observables we are able to obtain a dichotomic steering inequality with unbounded violation. Thus far, there is no analogous result for Bell inequalities. Interestingly, both the dichotomic inequality and one of our inequalities cannot be directly obtained from existing uncertainty relations, which strongly suggest the existence of an unknown kind of uncertainty relation.

  6. Generalized Input-Output Inequality Systems

    SciTech Connect

    Liu Yingfan Zhang Qinghong

    2006-09-15

    In this paper two types of generalized Leontief input-output inequality systems are introduced. The minimax properties for a class of functions associated with the inequalities are studied. Sufficient and necessary conditions for the inequality systems to have solutions are obtained in terms of the minimax value. Stability analysis for the solution set is provided in terms of upper semi-continuity and hemi-continuity of set-valued maps.

  7. Multipartite positive-partial-transpose inequalities exponentially stronger than local reality inequalities

    SciTech Connect

    Nagata, Koji

    2007-08-15

    We show that positivity of every partial transpose of N-partite quantum states implies inequalities on Bell correlations which are stronger than standard Bell inequalities by a factor of 2{sup (N-1)/2}. A violation of the inequality implies that the system is in a bipartite distillable entangled state. It turns out that a family of N-qubit bound entangled states proposed by Duer [Phys. Rev. Lett. 87, 230402 (2001)] violates the inequality for N{>=}4.

  8. Hard and Soft Constraints in Reliability-Based Design Optimization

    NASA Technical Reports Server (NTRS)

    Crespo, L.uis G.; Giesy, Daniel P.; Kenny, Sean P.

    2006-01-01

    This paper proposes a framework for the analysis and design optimization of models subject to parametric uncertainty where design requirements in the form of inequality constraints are present. Emphasis is given to uncertainty models prescribed by norm bounded perturbations from a nominal parameter value and by sets of componentwise bounded uncertain variables. These models, which often arise in engineering problems, allow for a sharp mathematical manipulation. Constraints can be implemented in the hard sense, i.e., constraints must be satisfied for all parameter realizations in the uncertainty model, and in the soft sense, i.e., constraints can be violated by some realizations of the uncertain parameter. In regard to hard constraints, this methodology allows (i) to determine if a hard constraint can be satisfied for a given uncertainty model and constraint structure, (ii) to generate conclusive, formally verifiable reliability assessments that allow for unprejudiced comparisons of competing design alternatives and (iii) to identify the critical combination of uncertain parameters leading to constraint violations. In regard to soft constraints, the methodology allows the designer (i) to use probabilistic uncertainty models, (ii) to calculate upper bounds to the probability of constraint violation, and (iii) to efficiently estimate failure probabilities via a hybrid method. This method integrates the upper bounds, for which closed form expressions are derived, along with conditional sampling. In addition, an l(sub infinity) formulation for the efficient manipulation of hyper-rectangular sets is also proposed.

  9. When does inequality freeze an economy?

    NASA Astrophysics Data System (ADS)

    Jerico, João Pedro; Landes, François P.; Marsili, Matteo; Pérez Castillo, Isaac; Volpati, Valerio

    2016-07-01

    Inequality and its consequences are the subject of intense recent debate. Using a simplified model of the economy, we address the relation between inequality and liquidity, the latter understood as the frequency of economic exchanges. Assuming a Pareto distribution of wealth for the agents, that is consistent with empirical findings, we find an inverse relation between wealth inequality and overall liquidity. We show that an increase in the inequality of wealth results in an even sharper concentration of the liquid financial resources. This leads to a congestion of the flow of goods and the arrest of the economy when the Pareto exponent reaches one.

  10. Compact Bell inequalities for multipartite experiments

    NASA Astrophysics Data System (ADS)

    Wu, Yu-Chun; Żukowski, Marek; Chen, Jing-Ling; Guo, Guang-Can

    2013-08-01

    A method for construction of multipartite Clauser-Horne-Shimony-Holt- (CHSH-) type Bell inequalities, for the case of local binary observables, is presented. The standard CHSH-type Bell inequalities can be obtained as special cases. An iterative method for deriving (N+1)-partite CHSH-type Bell inequalities from N-partite ones is derived. As an application, compact Bell inequalities for eight observers involving just four correlation functions are proposed. They require much less experimental effort than standard methods and thus are experimentally friendly in multiphoton experiments.

  11. Scalable Bell inequalities for multiqubit systems

    NASA Astrophysics Data System (ADS)

    He, Yingqiu; Ding, Dong; Yan, Fengli; Gao, Ting

    2015-08-01

    Based on Clauser-Horne-Shimony-Holt inequality, we show a fruitful method to exploit Bell inequalities for multipartite qubit systems. These Bell inequalities are designed with a simpler architecture tailored to experimental demonstration. With the point of view of the stabilizer formalism, we suggest a method to investigate quantum nonlocality for multipartite systems. Under the optimal setting we derive a set of compact Mermin-type inequalities and then discuss quantum violations for generalized Greenberger-Horne-Zeilinger (GGHZ) states and two kinds of mixed states. Also, as an example, we reveal relationship between quantum nonlocality and four-partite entanglement for four-qubit GGHZ states.

  12. Griffiths' inequalities for Ashkin-Teller model

    NASA Technical Reports Server (NTRS)

    Lee, C. T.

    1973-01-01

    The two Griffiths' (1967) inequalities for the correlation functions of Ising ferromagnets with two-body interactions, and two other inequalities obtained by Kelly and Sherman (1968) and by Sherman (1969) are shown to hold not only for the Ashkin-Teller (1943) model but also for a generalized Ashkin-Teller model (Kihara et al., 1954) with many-body interactions involving arbitrary clusters of particles. A cluster of particles is understood to mean a collection of pairs of particles rather than a group of particles. The four generalized inequalities under consideration are presented in the form of theorems, and a new inequality is obtained.

  13. No association between gender inequality and peak HIV prevalence in developing countries - an ecological study.

    PubMed

    Kenyon, Chris R; Buyze, Jozefien

    2015-01-01

    The prevalence of both gender inequality and HIV prevalence vary considerably both within all developing countries and within those in sub-Saharan Africa. We test the hypothesis that the extent of gender inequality is associated with national peak HIV prevalence. Linear regression was used to test the association between national peak HIV prevalence and three markers of gender equality - the gender-related development index (GDI), the gender empowerment measure (GEM), and the gender inequality index (GII). No evidence was found of a positive relationship between gender inequality and HIV prevalence, either in the analyses of all developing countries or those limited to Africa. In the bivariate analyses limited to Africa, there was a positive association between the two measures of gender "equality" and peak HIV prevalence (GDI: coefficient 28, 95% confidence interval (CI) 9.1-46.8; GEM: coefficient 54.8, 95% CI 20.5-89.1). There was also a negative association between the marker of gender "inequality" and peak HIV prevalence (GII: coefficient -66.9, 95% CI -112.8 to -21.0). These associations all disappeared on multivariate analyses. We could not find any evidence to support the hypothesis that variations in the extent of gender inequality explain variations in HIV prevalence in developing countries. PMID:25279690

  14. Linear-time algorithms for scheduling on parallel processors

    SciTech Connect

    Monma, C.L.

    1982-01-01

    Linear-time algorithms are presented for several problems of scheduling n equal-length tasks on m identical parallel processors subject to precedence constraints. This improves upon previous time bounds for the maximum lateness problem with treelike precedence constraints, the number-of-late-tasks problem without precedence constraints, and the one machine maximum lateness problem with general precedence constraints. 5 references.

  15. Semidefinite programming applications to Hartree-Fock and linear scaling electronic structure theories

    NASA Astrophysics Data System (ADS)

    Veera Raghavan, Srikant

    Semidefinite programming (SDP) is a relatively modern subfield of convex optimization which has been applied to many problems in the reduced density matrix (RDM) formulation of electronic structure. SDPs deal with minimization (or maximization) of linear objective functions of matrices, subject to linear equality and inequality constraints and positivity constraints on the eigenvalues of the matrices. Energies of chemical systems can be expressed as linear functions of RDMs, whose eigenvalues are electron occupation numbers or their products which are expected to be non-negative. Therefore, it is perhaps not surprising that SDPs fit rather naturally in the RDM framework in electronic structure. This dissertation presents SDP applications to two electronic structure theories. The first part of this dissertation (chaps. 1-3) reformulates Hartree-Fock theory in terms of SDPs in order to obtain upper and lower bounds to global Hartree-Fock energies. The upper and lower bounds on the energies are frequently equal thereby providing a first-ever certificate of global optimality for many Hartree-Fock solutions. The SDP approach provides an alternative to the conventional self-consistent field method of obtaining Hartree-Fock energies and densities with the added benefit of global optimality or a rigorous lower bound. Applications are made to the potential energy curves of (H 4)2, N2, C2, CN, Cr2 and NO2. Energies of the first-row transition elements are also calculated. In chapter 4, the effect of using the Hartree-Fock solutions that we calculate as references for coupled cluster singles doubles calculations is presented for some of the above molecules. The second part of this dissertation (chap. 5) presents a SDP approach to electronic structure methods which scale linearly with system size. Linear scaling electronic structure methods are essential in order to make calculations on large systems feasible. Among these methods the so-called density matrix based ones seek to

  16. Patterns of Inequality. Unit 3, The Philosophy of Equality and Inequality. Unit 4, Personal Inequality as an Ideological Concept.

    ERIC Educational Resources Information Center

    Hookham, Maurice; Holloway, Clive

    Open University course units are presented on the philosophy of equality and inequality (Unit 3) and on personal inequality as an ideological concept (Unit 4). The substance of Unit 3 consists of extracts from the writings of eight philosophers. The role of the philosopher in forming legitimatizing ideologies is also illustrated. The eight…

  17. Correlations between Income Inequality and Antimicrobial Resistance

    PubMed Central

    Kirby, Andrew; Herbert, Annie

    2013-01-01

    Objectives The aim of this study is to investigate if correlations exist between income inequality and antimicrobial resistance. This study’s hypothesis is that income inequality at the national level is positively correlated with antimicrobial resistance within developed countries. Data collection and analysis Income inequality data were obtained from the Standardized World Income Inequality Database. Antimicrobial resistance data were obtained from the European antimicrobial Resistance Surveillance Network and outpatient antimicrobial consumption data, measured by Defined daily Doses per 1000 inhabitants per day, from the European Surveillance of antimicrobial Consumption group. Spearman’s correlation coefficient (r) defined strengths of correlations of: > 0.8 as strong, > 0.5 as moderate and > 0.2 as weak. Confidence intervals and p values were defined for all r values. Correlations were calculated for the time period 2003-10, for 15 European countries. Results Income inequality and antimicrobial resistance correlations which were moderate or strong, with 95% confidence intervals > 0, included the following. Enterococcus faecalis resistance to aminopenicillins, vancomycin and high level gentamicin was moderately associated with income inequality (r= ≥0.54 for all three antimicrobials). Escherichia coli resistance to aminoglycosides, aminopenicillins, third generation cephalosporins and fluoroquinolones was moderately-strongly associated with income inequality (r= ≥0.7 for all four antimicrobials). Klebsiella pneumoniae resistance to third generation cephalosporins, aminoglycosides and fluoroquinolones was moderately associated with income inequality (r= ≥0.5 for all three antimicrobials). Staphylococcus aureus methicillin resistance and income inequality were strongly associated (r=0.87). Conclusion As income inequality increases in European countries so do the rates of antimicrobial resistance for bacteria including E. faecalis, E. coli, K. pneumoniae

  18. Neural Network-Based Control of Networked Trilateral Teleoperation With Geometrically Unknown Constraints.

    PubMed

    Li, Zhijun; Xia, Yuanqing; Wang, Dehong; Zhai, Di-Hua; Su, Chun-Yi; Zhao, Xingang

    2016-05-01

    Most studies on bilateral teleoperation assume known system kinematics and only consider dynamical uncertainties. However, many practical applications involve tasks with both kinematics and dynamics uncertainties. In this paper, trilateral teleoperation systems with dual-master-single-slave framework are investigated, where a single robotic manipulator constrained by an unknown geometrical environment is controlled by dual masters. The network delay in the teleoperation system is modeled as Markov chain-based stochastic delay, then asymmetric stochastic time-varying delays, kinematics and dynamics uncertainties are all considered in the force-motion control design. First, a unified dynamical model is introduced by incorporating unknown environmental constraints. Then, by exact identification of constraint Jacobian matrix, adaptive neural network approximation method is employed, and the motion/force synchronization with time delays are achieved without persistency of excitation condition. The neural networks and parameter adaptive mechanism are combined to deal with the system uncertainties and unknown kinematics. It is shown that the system is stable with the strict linear matrix inequality-based controllers. Finally, the extensive simulation experiment studies are provided to demonstrate the performance of the proposed approach. PMID:25956001

  19. Bell inequality tests of four-photon six-qubit graph states

    SciTech Connect

    Gao Weibo; Yao Xingcan; Xu Ping; Lu He; Lu Chaoyang; Yang Tao; Chen Zengbing; Guehne, Otfried; Cabello, Adan; Pan Jianwei

    2010-10-15

    We now experimentally demonstrate a Y-shaped graph state with photons' polarization and spatial modes as qubits. Based on this state and a linear-type graph state, we report on the experimental realization of two different Bell inequality tests, which represent higher violation than previous Bell tests.

  20. Inequality, deprivation and alcohol use.

    PubMed

    Marmot, M

    1997-03-01

    There are major social inequalities in health within societies. Alcohol and tobacco are major preventable causes of ill health. Using data from the United Kingdom, this paper examines the social distribution of tobacco and alcohol consumption; the role that tobacco and alcohol may play in mediating or modifying social inequalities in health; and the implications of social distribution for policies to reduce harm associated with consumption of alcohol and tobacco. In the United Kingdom, as in many other countries, there is clear inverse association between socio-economic position and consumption of cigarettes. Over the past three decades, the decline in smoking has been more rapid in men and women in higher socio-economic groups. United Kingdom suggest that among employed men and women, the prevalence of non-drinking shows an inverse association with occupational status; heavy drinking differs little; and moderate drinking is more common among those of higher socio-economic status. Smoking accounts for perhaps 25% of the social class difference in coronary heart disease (CHD) mortality, more for lung cancer, less for some other diseases. healthier patterns of drinking may contribute to the lower CHD rates of higher social classes. Although other factors are clearly important in generating social inequalities, it is important to take the social distribution of alcohol and tobacco into account when formulating policy. For cigarette consumption, there is evidence that in lower socio-economic groups demand is more sensitive to price; higher socio-economic groups are more responsive to health education. There has been less research of this nature for alcohol. Available analyses suggest that price responsiveness of heavy drinking may be greatest in young men and in those with lower incomes. A pricing strategy has important equity implications. PMID:9167283

  1. Socioeconomic Inequalities in Heart Failure.

    PubMed

    Díaz-Toro, Felipe; Verdejo, Hugo E; Castro, Pablo F

    2015-10-01

    Prevalence and incidence of chronic heart failure (CHF) has increased during the past decades. Beyond its impact on mortality rates, CHF severely impairs quality of life, particularly with the elderly and vulnerable population. Several studies have shown that CHF takes its toll mostly on the uneducated, low-income population, who exhibit impaired access to health care systems, less knowledge regarding its pathology and poorer self-care behaviors. This review summarizes the available evidence linking socioeconomic inequalities and CHF, focusing on the modifiable factors that may explain the impaired health outcomes in socioeconomically deprived populations. PMID:26462090

  2. Entropy power inequalities for qudits

    NASA Astrophysics Data System (ADS)

    Audenaert, Koenraad; Datta, Nilanjana; Ozols, Maris

    2016-05-01

    Shannon's entropy power inequality (EPI) can be viewed as a statement of concavity of an entropic function of a continuous random variable under a scaled addition rule: f ( √{ a } X + √{ 1 - a } Y ) ≥ a f ( X ) + ( 1 - a ) f ( Y ) ∀ a ∈ [ 0 , 1 ] . Here, X and Y are continuous random variables and the function f is either the differential entropy or the entropy power. König and Smith [IEEE Trans. Inf. Theory 60(3), 1536-1548 (2014)] and De Palma, Mari, and Giovannetti [Nat. Photonics 8(12), 958-964 (2014)] obtained quantum analogues of these inequalities for continuous-variable quantum systems, where X and Y are replaced by bosonic fields and the addition rule is the action of a beam splitter with transmissivity a on those fields. In this paper, we similarly establish a class of EPI analogues for d-level quantum systems (i.e., qudits). The underlying addition rule for which these inequalities hold is given by a quantum channel that depends on the parameter a ∈ [0, 1] and acts like a finite-dimensional analogue of a beam splitter with transmissivity a, converting a two-qudit product state into a single qudit state. We refer to this channel as a partial swap channel because of the particular way its output interpolates between the states of the two qudits in the input as a is changed from zero to one. We obtain analogues of Shannon's EPI, not only for the von Neumann entropy and the entropy power for the output of such channels, but also for a much larger class of functions. This class includes the Rényi entropies and the subentropy. We also prove a qudit analogue of the entropy photon number inequality (EPnI). Finally, for the subclass of partial swap channels for which one of the qudit states in the input is fixed, our EPIs and EPnI yield lower bounds on the minimum output entropy and upper bounds on the Holevo capacity.

  3. An Isoperimetric Inequality for Fundamental Tones of Free Plates

    NASA Astrophysics Data System (ADS)

    Chasman, L. M.

    2010-03-01

    We establish an isoperimetric inequality for the fundamental tone (first nonzero eigenvalue) of the free plate of a given area, proving the ball is maximal. Given τ>0, the free plate eigenvalues omega and eigenfunctions u are determined by the equation DeltaDelta u-τDelta u = omega u together with certain natural boundary conditions. The boundary conditions are complicated but arise naturally from the plate Rayleigh quotient, which contains a Hessian squared term |D^2u|^2. We adapt Weinberger's method from the corresponding free membrane problem, taking the fundamental modes of the unit ball as trial functions. These solutions are a linear combination of Bessel and modified Bessel functions.

  4. Some properties of constraints in theories with degenerate Lagrangians

    SciTech Connect

    Nesterenko, V.V.; Chervyakov, A.M.

    1986-01-01

    The Poisson brackets of the primary constraints are expressed by means of linear differential operators in terms of Lagrangian constraints. In the framework of the Lagrangian formalism the authors propose a sufficient criterion for existence in the theory of second class constraints. It is shown that invariance of the action with respect to transformations with arbitrary functions of the time leads to primary constraints that are in involution with one another and with the canonical Hamiltonian, at least in the weak sense. It follows from the analysis of the functional arbitrariness in the solutions of the Hamilton equations that such primary constraints must be first-class constraints.

  5. An Efficacious Multi-Objective Fuzzy Linear Programming Approach for Optimal Power Flow Considering Distributed Generation

    PubMed Central

    Warid, Warid; Hizam, Hashim; Mariun, Norman; Abdul-Wahab, Noor Izzri

    2016-01-01

    This paper proposes a new formulation for the multi-objective optimal power flow (MOOPF) problem for meshed power networks considering distributed generation. An efficacious multi-objective fuzzy linear programming optimization (MFLP) algorithm is proposed to solve the aforementioned problem with and without considering the distributed generation (DG) effect. A variant combination of objectives is considered for simultaneous optimization, including power loss, voltage stability, and shunt capacitors MVAR reserve. Fuzzy membership functions for these objectives are designed with extreme targets, whereas the inequality constraints are treated as hard constraints. The multi-objective fuzzy optimal power flow (OPF) formulation was converted into a crisp OPF in a successive linear programming (SLP) framework and solved using an efficient interior point method (IPM). To test the efficacy of the proposed approach, simulations are performed on the IEEE 30-busand IEEE 118-bus test systems. The MFLP optimization is solved for several optimization cases. The obtained results are compared with those presented in the literature. A unique solution with a high satisfaction for the assigned targets is gained. Results demonstrate the effectiveness of the proposed MFLP technique in terms of solution optimality and rapid convergence. Moreover, the results indicate that using the optimal DG location with the MFLP algorithm provides the solution with the highest quality. PMID:26954783

  6. An Efficacious Multi-Objective Fuzzy Linear Programming Approach for Optimal Power Flow Considering Distributed Generation.

    PubMed

    Warid, Warid; Hizam, Hashim; Mariun, Norman; Abdul-Wahab, Noor Izzri

    2016-01-01

    This paper proposes a new formulation for the multi-objective optimal power flow (MOOPF) problem for meshed power networks considering distributed generation. An efficacious multi-objective fuzzy linear programming optimization (MFLP) algorithm is proposed to solve the aforementioned problem with and without considering the distributed generation (DG) effect. A variant combination of objectives is considered for simultaneous optimization, including power loss, voltage stability, and shunt capacitors MVAR reserve. Fuzzy membership functions for these objectives are designed with extreme targets, whereas the inequality constraints are treated as hard constraints. The multi-objective fuzzy optimal power flow (OPF) formulation was converted into a crisp OPF in a successive linear programming (SLP) framework and solved using an efficient interior point method (IPM). To test the efficacy of the proposed approach, simulations are performed on the IEEE 30-busand IEEE 118-bus test systems. The MFLP optimization is solved for several optimization cases. The obtained results are compared with those presented in the literature. A unique solution with a high satisfaction for the assigned targets is gained. Results demonstrate the effectiveness of the proposed MFLP technique in terms of solution optimality and rapid convergence. Moreover, the results indicate that using the optimal DG location with the MFLP algorithm provides the solution with the highest quality. PMID:26954783

  7. Children Discard a Resource to Avoid Inequity

    ERIC Educational Resources Information Center

    Shaw, Alex; Olson, Kristina R.

    2012-01-01

    Elucidating how inequity aversion (a tendency to dislike and correct unequal outcomes) functions as one develops is important to understanding more complex fairness considerations in adulthood. Although previous research has demonstrated that adults and children reduce inequity, it is unclear if people are actually responding negatively to…

  8. Health Inequities: Evaluation of Two Paradigms

    ERIC Educational Resources Information Center

    Ashcroft, Rachelle

    2010-01-01

    Social work practice in health is shaped by underlying paradigms. To effectively target health inequities, practitioners need to consider appropriate paradigms. In this exploration of how six health paradigms shape theory and practice, the two health paradigms that most attended to health inequalities are social determinants of health and…

  9. Children discard a resource to avoid inequity.

    PubMed

    Shaw, Alex; Olson, Kristina R

    2012-05-01

    Elucidating how inequity aversion (a tendency to dislike and correct unequal outcomes) functions as one develops is important to understanding more complex fairness considerations in adulthood. Although previous research has demonstrated that adults and children reduce inequity, it is unclear if people are actually responding negatively to inequity or if people dislike others getting more than them (motivated by social comparison) and like to share maximal resources, especially with those who have few resources (motivated by social welfare preferences). In order to evaluate if children are truly averse to inequity, we had 3- to 8-year-old children distribute resources to 3rd parties and found that 6- to 8-year-old children would rather throw a resource in the trash than distribute unequally, suggesting that concerns with equity can trump concerns with maximal sharing. We also demonstrated that children's reactions were not based on wanting to avoid upsetting the recipients or based on a preference for visual symmetry and that children will even throw away a resource that could have gone to themselves in order to avoid inequity. These results demonstrate the existence of inequity aversion in children, provide a new method for studying inequity aversion specifically, and suggest the need for new models to explain why inequity aversion may have evolved. PMID:22004168

  10. Inequality of Paediatric Workforce Distribution in China.

    PubMed

    Song, Peige; Ren, Zhenghong; Chang, Xinlei; Liu, Xuebei; An, Lin

    2016-01-01

    Child health has been addressed as a priority at both global and national levels for many decades. In China, difficulty of accessing paediatricians has been of debate for a long time, however, there is limited evidence to assess the population- and geography-related inequality of paediatric workforce distribution. This study aimed to analyse the inequality of the distributions of the paediatric workforce (including paediatricians and paediatric nurses) in China by using Lorenz curve, Gini coefficient, and Theil L index, data were obtained from the national maternal and child health human resource sampling survey conducted in 2010. In this study, we found that the paediatric workforce was the most inequitable regarding the distribution of children <7 years, the geographic distribution of the paediatric workforce highlighted very severe inequality across the nation, except the Central region. For different professional types, we found that, except the Central region, the level of inequality of paediatric nurses was higher than that of the paediatricians regarding both the demographic and geographic distributions. The inner-regional inequalities were the main sources of the paediatric workforce distribution inequality. To conclude, this study revealed the inadequate distribution of the paediatric workforce in China for the first time, substantial inequality of paediatric workforce distribution still existed across the nation in 2010, more research is still needed to explore the in-depth sources of inequality, especially the urban-rural variance and the inner- and inter-provincial differences, and to guide national and local health policy-making and resource allocation. PMID:27420083

  11. Hispanic Population Growth and Rural Income Inequality

    ERIC Educational Resources Information Center

    Parrado, Emilio A.; Kandel, William A.

    2010-01-01

    We analyze the relationship between Hispanic population growth and changes in U.S. rural income inequality from 1990 through 2000. Applying comparative approaches used for urban areas we disentangle Hispanic population growth's contribution to inequality by comparing and statistically modeling changes in the family income Gini coefficient across…

  12. American Higher Education and Income Inequality

    ERIC Educational Resources Information Center

    Hill, Catharine B.

    2016-01-01

    This paper demonstrates that increasing income inequality can contribute to the trends we see in American higher education, particularly in the selective, private nonprofit and public sectors. Given these institutions' selective admissions and commitment to socioeconomic diversity, the paper demonstrates how increasing income inequality leads to…

  13. Inequality of Paediatric Workforce Distribution in China

    PubMed Central

    Song, Peige; Ren, Zhenghong; Chang, Xinlei; Liu, Xuebei; An, Lin

    2016-01-01

    Child health has been addressed as a priority at both global and national levels for many decades. In China, difficulty of accessing paediatricians has been of debate for a long time, however, there is limited evidence to assess the population- and geography-related inequality of paediatric workforce distribution. This study aimed to analyse the inequality of the distributions of the paediatric workforce (including paediatricians and paediatric nurses) in China by using Lorenz curve, Gini coefficient, and Theil L index, data were obtained from the national maternal and child health human resource sampling survey conducted in 2010. In this study, we found that the paediatric workforce was the most inequitable regarding the distribution of children <7 years, the geographic distribution of the paediatric workforce highlighted very severe inequality across the nation, except the Central region. For different professional types, we found that, except the Central region, the level of inequality of paediatric nurses was higher than that of the paediatricians regarding both the demographic and geographic distributions. The inner-regional inequalities were the main sources of the paediatric workforce distribution inequality. To conclude, this study revealed the inadequate distribution of the paediatric workforce in China for the first time, substantial inequality of paediatric workforce distribution still existed across the nation in 2010, more research is still needed to explore the in-depth sources of inequality, especially the urban-rural variance and the inner- and inter-provincial differences, and to guide national and local health policy-making and resource allocation. PMID:27420083

  14. Income Inequality, Global Economy and the State

    ERIC Educational Resources Information Center

    Lee, Cheol-Sung; Nielsen, Francois; Alderson, Arthur S.

    2007-01-01

    We investigate interrelationship among income inequality, global economy and the role of the state using an unbalanced panel data set with 311 observations on 60 countries, dated from 1970 to 1994. The analysis proceeds in two stages. First, we test for effects on income inequality of variables characterizing the situation of a society in the…

  15. Students' Understandings and Misconceptions of Algebraic Inequalities

    ERIC Educational Resources Information Center

    Rowntree, Rebecca V.

    2009-01-01

    The National Council of Teachers of Mathematics [NCTM] requires students in grades nine through 12 to be able to explain inequalities using mathematical relational symbols and be able to understand the meaning of inequalities and their solutions (NCTM, 2000). Studies have shown that not only middle and high school students have difficulties with…

  16. Growing Income Inequality Threatens American Education

    ERIC Educational Resources Information Center

    Duncan, Greg J.; Murnane, Richard J.

    2014-01-01

    The first of two articles in consecutive months describes the origins and nature of growing income inequality, and some of its consequences for American children. It documents the increased family income inequality that's occurred over the past 40 years and shows that the increased income disparity has been more than matched by an expanding…

  17. Income Inequality and the Education Divide.

    ERIC Educational Resources Information Center

    Welch, Mary A., Ed.

    1998-01-01

    The economics of the decision to go to college or obtain technical training is discussed in this booklet. To stay competitive in the job market requires constant educational updating. The following questions are discussed: (1) how income inequality is measured; (2) how income is distributed in the United States; (3) why income inequality is…

  18. Aspects of Territorial Inequality in Education

    ERIC Educational Resources Information Center

    Ryba, Raymond

    1976-01-01

    Draws attention to two territorial aspects of educational inequality and considers the implications which studying them helps to highlight. The two aspects are: (1) the high degree of success which researchers have experienced in dealing with educational phenomena in this way; (2) the fact that these inequalities prevail from the international to…

  19. The effect of ageing on health inequalities.

    PubMed

    Matthews, David

    The final article in this five-part series on the relationship between sociology and nursing practice discusses age-related health inequalities. Age has a direct influence on individuals' health and wellbeing. From a sociological viewpoint, individuals' health status in old age is a reflection of experiences throughout their lifetime, which means that health inequalities accumulate. PMID:26665634

  20. Health Inequalities: Trends, Progress, and Policy

    PubMed Central

    Bleich, Sara N.; Jarlenski, Marian P.; Bell, Caryn N.; LaVeist, Thomas A.

    2013-01-01

    Health inequalities, which have been well documented for decades, have more recently become policy targets in developed countries. This review describes time trends in health inequalities (by sex, race/ethnicity, and socioeconomic status), commitments to reduce health inequalities, and progress made to eliminate health inequalities in the United States, United Kingdom, and other OECD countries. Time-trend data in the United States indicate a narrowing of the gap between the best- and worst-off groups in some health indicators, such as life expectancy, but a widening of the gap in others, such as diabetes prevalence. Similarly, time-trend data in the United Kingdom indicate a narrowing of the gap between the best- and worst-off groups in some indicators, such as hypertension prevalence, whereas the gap between social classes has increased for life expectancy. More research and better methods are needed to measure precisely the relationships between stated policy goals and observed trends in health inequalities. PMID:22224876

  1. Inequalities for a polynomial and its derivative

    NASA Astrophysics Data System (ADS)

    Chanam, Barchand; Dewan, K. K.

    2007-12-01

    Let , 1[less-than-or-equals, slant][mu][less-than-or-equals, slant]n, be a polynomial of degree n such that p(z)[not equal to]0 in z0, then for 0Inequalities for a polynomial and its derivative, Math. Inequal. Appl. 2 (2) (1999) 203-205] proved Equality holds for the polynomial where n is a multiple of [mu]E In this paper, we obtain an improvement of the above inequality by involving some of the coefficients. As an application of our result, we further improve upon a result recently proved by Aziz and Shah [A. Aziz, W.M. Shah, Inequalities for a polynomial and its derivative, Math. Inequal. Appl. 7 (3) (2004) 379-391].

  2. Inequalities in health and gender.

    PubMed

    Haavio-Mannila, E

    1986-01-01

    Gender inequalities in health are studied in Denmark, Finland, Norway and Sweden on the basis of survey data on morbidity and symptoms of anxiety, and of mental hospitalization statistics. Women have higher rates of illness than men in countries where, and in periods when, they have to a great extent stayed at home as full-time housewives. Participation in paid economic activity and the resulting economical independence thus seems to be beneficial to women's health on the macro-level of society. On the micro-level of individual families, inequality in morbidity by gender is smaller in families with two economical providers than in families where the wife stays at home. The anxiety rates of employed wives are, however, relatively high compared with those of men and non-employed wives. Only in Sweden is the mental health of employed wives good, perhaps because of supportive social policies favouring women's work outside the home. The strain involved in combining family and work among women thus becomes manifest in the appearance of symptoms of anxiety but not in physical morbidity nor mental hospitalization. PMID:3961534

  3. A global approach to kinematic path planning to robots with holonomic and nonholonomic constraints

    NASA Technical Reports Server (NTRS)

    Divelbiss, Adam; Seereeram, Sanjeev; Wen, John T.

    1993-01-01

    Robots in applications may be subject to holonomic or nonholonomic constraints. Examples of holonomic constraints include a manipulator constrained through the contact with the environment, e.g., inserting a part, turning a crank, etc., and multiple manipulators constrained through a common payload. Examples of nonholonomic constraints include no-slip constraints on mobile robot wheels, local normal rotation constraints for soft finger and rolling contacts in grasping, and conservation of angular momentum of in-orbit space robots. The above examples all involve equality constraints; in applications, there are usually additional inequality constraints such as robot joint limits, self collision and environment collision avoidance constraints, steering angle constraints in mobile robots, etc. The problem of finding a kinematically feasible path that satisfies a given set of holonomic and nonholonomic constraints, of both equality and inequality types is addressed. The path planning problem is first posed as a finite time nonlinear control problem. This problem is subsequently transformed to a static root finding problem in an augmented space which can then be iteratively solved. The algorithm has shown promising results in planning feasible paths for redundant arms satisfying Cartesian path following and goal endpoint specifications, and mobile vehicles with multiple trailers. In contrast to local approaches, this algorithm is less prone to problems such as singularities and local minima.

  4. Utilizing the Zero-One Linear Programming Constraints to Draw Multiple Sets of Matched Samples from a Non-Treatment Population as Control Groups for the Quasi-Experimental Design

    ERIC Educational Resources Information Center

    Li, Yuan H.; Yang, Yu N.; Tompkins, Leroy J.; Modarresi, Shahpar

    2005-01-01

    The statistical technique, "Zero-One Linear Programming," that has successfully been used to create multiple tests with similar characteristics (e.g., item difficulties, test information and test specifications) in the area of educational measurement, was deemed to be a suitable method for creating multiple sets of matched samples to be used as…

  5. Constraint monitoring in TOSCA

    NASA Technical Reports Server (NTRS)

    Beck, Howard

    1992-01-01

    The Job-Shop Scheduling Problem (JSSP) deals with the allocation of resources over time to factory operations. Allocations are subject to various constraints (e.g., production precedence relationships, factory capacity constraints, and limits on the allowable number of machine setups) which must be satisfied for a schedule to be valid. The identification of constraint violations and the monitoring of constraint threats plays a vital role in schedule generation in terms of the following: (1) directing the scheduling process; and (2) informing scheduling decisions. This paper describes a general mechanism for identifying constraint violations and monitoring threats to the satisfaction of constraints throughout schedule generation.

  6. A Gibbons-Penrose Inequality for Surfaces in Schwarzschild Spacetime

    NASA Astrophysics Data System (ADS)

    Brendle, Simon; Wang, Mu-Tao

    2014-08-01

    We propose a geometric inequality for two-dimensional spacelike surfaces in the Schwarzschild spacetime. This inequality implies the Penrose inequality for collapsing dust shells in general relativity, as proposed by Penrose and Gibbons. We prove that the inequality holds in several important cases.

  7. On the Penrose inequality along null hypersurfaces

    NASA Astrophysics Data System (ADS)

    Mars, Marc; Soria, Alberto

    2016-06-01

    The null Penrose inequality, i.e. the Penrose inequality in terms of the Bondi energy, is studied by introducing a functional on surfaces and studying its properties along a null hypersurface Ω extending to past null infinity. We prove a general Penrose-type inequality which involves the limit at infinity of the Hawking energy along a specific class of geodesic foliations called Geodesic Asymptotically Bondi (GAB), which are shown to always exist. Whenever this foliation approaches large spheres, this inequality becomes the null Penrose inequality and we recover the results of Ludvigsen–Vickers (1983 J. Phys. A: Math. Gen. 16 3349–53) and Bergqvist (1997 Class. Quantum Grav. 14 2577–83). By exploiting further properties of the functional along general geodesic foliations, we introduce an approach to the null Penrose inequality called the Renormalized Area Method and find a set of two conditions which imply the validity of the null Penrose inequality. One of the conditions involves a limit at infinity and the other a restriction on the spacetime curvature along the flow. We investigate their range of applicability in two particular but interesting cases, namely the shear-free and vacuum case, where the null Penrose inequality is known to hold from the results by Sauter (2008 PhD Thesis Zürich ETH), and the case of null shells propagating in the Minkowski spacetime. Finally, a general inequality bounding the area of the quasi-local black hole in terms of an asymptotic quantity intrinsic of Ω is derived.

  8. Linear Accelerators

    SciTech Connect

    Sidorin, Anatoly

    2010-01-05

    In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

  9. Linear Accelerators

    NASA Astrophysics Data System (ADS)

    Sidorin, Anatoly

    2010-01-01

    In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

  10. [Society, economy, inequities and dengue].

    PubMed

    Kouri, Gustavo; Pelegrino, José L; Munster, Blanca María; Guzmán, María G

    2007-01-01

    Dengue and dengue hemorrhagic fever in the Americas have been on the rise throughout the 1990s, with the highest number -over one million cases- reported in 2002. This paper analyzed the situation of dengue in the region and discussed the determining factors that account for the rise of the disease, making emphasis on socioeconomic factors, such as poverty, inequality, migrations and the lack of access to basic services, which are the most influential in perpetuating this disease in most countries. Considering that a safe and accessible vaccine is now unavailable, basic principles of vector control combined with political willingness, inter-sectoral involvement, active community participation and the tightening of health legislation were also examined as the only viable solution at present. PMID:23427454

  11. Discrimination, Perceived Social Inequity, and Mental Health Among Rural-to-Urban Migrants in China

    PubMed Central

    Lin, Danhua; Wang, Bo; Hong, Yan; Qin, Xiong; Stanton, Bonita

    2010-01-01

    Status-based discrimination and inequity have been associated with the process of migration, especially with economics-driven internal migration. However, their association with mental health among economy-driven internal migrants in developing countries is rarely assessed. This study examines discriminatory experiences and perceived social inequity in relation to mental health status among rural-to-urban migrants in China. Cross-sectional data were collected from 1,006 rural-to-urban migrants in 2004–2005 in Beijing, China. Participants reported their perceptions and experiences of being discriminated in daily life in urban destination and perceived social inequity. Mental health was measured using the symptom checklist-90 (SCL-90). Multivariate analyses using general linear model were performed to test the effect of discriminatory experience and perceived social inequity on mental health. Experience of discrimination was positively associated with male gender, being married at least once, poorer health status, shorter duration of migration, and middle range of personal income. Likewise, perceived social inequity was associated with poorer health status, higher education attainment, and lower personal income. Multivariate analyses indicate that both experience of discrimination and perceived social inequity were strongly associated with mental health problems of rural-to-urban migrants. Experience of discrimination in daily life and perceived social inequity have a significant influence on mental health among rural-to-urban migrants. The findings underscore the needs to reduce public or societal discrimination against rural-to-urban migrants, to eliminate structural barriers (i.e., dual household registrations) for migrants to fully benefit from the urban economic development, and to create a positive atmosphere to improve migrant's psychological well-being. PMID:20033772

  12. Symbolic Capital, Consumption, and Health Inequality

    PubMed Central

    2011-01-01

    Research on economic inequalities in health has been largely polarized between psychosocial and neomaterial approaches. Examination of symbolic capital—the material display of social status and how it is structurally constrained—is an underutilized way of exploring economic disparities in health and may help to resolve the existing theoretical polarization. In contemporary society, what people do with money and how they consume and display symbols of wealth may be as important as income itself. After tracing the historical rise of consumption in capitalist society and its interrelationship with economic inequality, I discuss evidence for the role of symbolic capital in health inequalities and suggest directions for future research. PMID:21164087

  13. Towards information inequalities for generalized graph entropies.

    PubMed

    Sivakumar, Lavanya; Dehmer, Matthias

    2012-01-01

    In this article, we discuss the problem of establishing relations between information measures for network structures. Two types of entropy based measures namely, the Shannon entropy and its generalization, the Rényi entropy have been considered for this study. Our main results involve establishing formal relationships, by means of inequalities, between these two kinds of measures. Further, we also state and prove inequalities connecting the classical partition-based graph entropies and partition-independent entropy measures. In addition, several explicit inequalities are derived for special classes of graphs. PMID:22715375

  14. A simple proof of Bell's inequality

    NASA Astrophysics Data System (ADS)

    Maccone, Lorenzo

    2013-11-01

    Bell's theorem is a fundamental result in quantum mechanics: it discriminates between quantum mechanics and all theories where probabilities in measurement results arise from the ignorance of pre-existing local properties. We give an extremely simple proof of Bell's inequality; a single figure suffices. This simplicity may be useful in the unending debate over what exactly the Bell inequality means, because the hypotheses underlying the proof become transparent. It is also a useful didactic tool, as the Bell inequality can be explained in a single intuitive lecture.

  15. Linear matrix inequalities for analysis and control of linear vector second-order systems

    SciTech Connect

    Adegas, Fabiano D.; Stoustrup, Jakob

    2014-10-06

    Many dynamical systems are modeled as vector second-order differential equations. This paper presents analysis and synthesis conditions in terms of LMI with explicit dependence in the coefficient matrices of vector second-order systems. These conditions benefit from the separation between the Lyapunov matrix and the system matrices by introducing matrix multipliers, which potentially reduce conservativeness in hard control problems. Multipliers facilitate the usage of parameter-dependent Lyapunov functions as certificates of stability of uncertain and time-varying vector second-order systems. The conditions introduced in this work have the potential to increase the practice of analyzing and controlling systems directly in vector second-order form.

  16. Twenty years of socioeconomic inequalities in premature mortality in Barcelona: The influence of population and neighbourhood changes.

    PubMed

    Rodríguez-Sanz, Maica; Gotsens, Mercè; Marí-Dell'Olmo, Marc; Mehdipanah, Roshanak; Borrell, Carme

    2016-05-01

    The objective of this study was to analyse trends in socioeconomic inequalities in premature mortality in Barcelona from 1992 to 2011, accounting for population changes. We conducted a repeated cross-sectional study of the Barcelona population (25-64 years) using generalized linear mixed models for trend analysis, and found that socioeconomic inequalities in premature mortality persisted between neighbourhoods, but tended to diminish. However, the reduction in inequality was related to an increase in the number of foreign-born individuals mainly in socioeconomic disadvantaged neighbourhoods, in which the decrease in premature mortality was more marked. To study trends in geographical inequalities in mortality, it is essential to understand demographic changes occurred in different places related to local levels of deprivation. PMID:27105035

  17. The Inequality Footprints of Nations: A Novel Approach to Quantitative Accounting of Income Inequality

    PubMed Central

    Alsamawi, Ali; Murray, Joy; Lenzen, Manfred; Moran, Daniel; Kanemoto, Keiichiro

    2014-01-01

    In this study we use economic input-output analysis to calculate the inequality footprint of nations. An inequality footprint shows the link that each country's domestic economic activity has to income distribution elsewhere in the world. To this end we use employment and household income accounts for 187 countries and an historical time series dating back to 1990. Our results show that in 2010, most developed countries had an inequality footprint that was higher than their within-country inequality, meaning that in order to support domestic lifestyles, these countries source imports from more unequal economies. Amongst exceptions are the United States and United Kingdom, which placed them on a par with many developing countries. Russia has a high within-country inequality nevertheless it has the lowest inequality footprint in the world, which is because of its trade connections with the Commonwealth of Independent States and Europe. Our findings show that the commodities that are inequality-intensive, such as electronic components, chemicals, fertilizers, minerals, and agricultural products often originate in developing countries characterized by high levels of inequality. Consumption of these commodities may implicate within-country inequality in both developing and developed countries. PMID:25353333

  18. Unification of Bell, Leggett-Garg and Kochen-Specker inequalities: Hybrid spatio-temporal inequalities

    NASA Astrophysics Data System (ADS)

    Das, Siddhartha; Aravinda, S.; Srikanth, R.; Home, Dipankar

    2013-12-01

    The Bell-type (spatial), Kochen-Specker (contextuality) or Leggett-Garg (temporal) inequalities are based on classically plausible but otherwise quite distinct assumptions. For any of these inequalities, satisfaction is equivalent to a joint probability distribution for all observables in the experiment. This implies a joint distribution for all pairs of observables, and is indifferent to whether or not they commute in the theory. This indifference underpins a unification of the above inequalities into a general framework of correlation inequalities. When the physical scenario is such that the correlated pairs are all compatible, the resulting correlation is nonsignaling, which may be local or multi-particle, corresponding to contextuality or Bell-type inequalities. If the pairs are incompatible, the resulting correlation corresponds to Leggett-Garg (LG) inequalities. That quantum mechanics (QM) violates all these inequalities suggests a close connection between the local, spatial and temporal properties of the theory. As a concrete manifestation of the unification, we extend the method due to Roy and Singh (J. Phys. A, 11 (1978) L167) to derive and study a new class of hybrid spatio-temporal inequalities, where the correlated pairs in the experiment are both compatible or incompatible. The implications for cryptography and monogamy inequalities of the unification are briefly touched upon.

  19. A note on a model for quay crane scheduling with non-crossing constraints

    NASA Astrophysics Data System (ADS)

    Santini, Alberto; Alsing Friberg, Henrik; Ropke, Stefan

    2015-06-01

    This article studies the quay crane scheduling problem with non-crossing constraints, which is an operational problem that arises in container terminals. An enhancement to a mixed integer programming model for the problem is proposed and a new class of valid inequalities is introduced. Computational results show the effectiveness of these enhancements in solving the problem to optimality.

  20. Neural responses to advantageous and disadvantageous inequity.

    PubMed

    Fliessbach, Klaus; Phillipps, Courtney B; Trautner, Peter; Schnabel, Marieke; Elger, Christian E; Falk, Armin; Weber, Bernd

    2012-01-01

    In this paper we study neural responses to inequitable distributions of rewards despite equal performance. We specifically focus on differences between advantageous inequity (AI) and disadvantageous inequity (DI). AI and DI were realized in a hyperscanning functional magnetic resonance imaging (fMRI) experiment with pairs of subjects simultaneously performing a task in adjacent scanners and observing both subjects' rewards. Results showed (1) hypoactivation of the ventral striatum (VS) under DI but not under AI; (2) inequity induced activation of the right dorsolateral prefrontal cortex (DLPFC) that was stronger under DI than under AI; (3) correlations between subjective evaluations of AI evaluation and bilateral ventrolateral prefrontal and left insular activity. Our study provides neurophysiological evidence for different cognitive processes that occur when exposed to DI and AI, respectively. One possible interpretation is that any form of inequity represents a norm violation, but that important differences between AI and DI emerge from an asymmetric involvement of status concerns. PMID:22701414

  1. Neural responses to advantageous and disadvantageous inequity

    PubMed Central

    Fliessbach, Klaus; Phillipps, Courtney B.; Trautner, Peter; Schnabel, Marieke; Elger, Christian E.; Falk, Armin; Weber, Bernd

    2012-01-01

    In this paper we study neural responses to inequitable distributions of rewards despite equal performance. We specifically focus on differences between advantageous inequity (AI) and disadvantageous inequity (DI). AI and DI were realized in a hyperscanning functional magnetic resonance imaging (fMRI) experiment with pairs of subjects simultaneously performing a task in adjacent scanners and observing both subjects' rewards. Results showed (1) hypoactivation of the ventral striatum (VS) under DI but not under AI; (2) inequity induced activation of the right dorsolateral prefrontal cortex (DLPFC) that was stronger under DI than under AI; (3) correlations between subjective evaluations of AI evaluation and bilateral ventrolateral prefrontal and left insular activity. Our study provides neurophysiological evidence for different cognitive processes that occur when exposed to DI and AI, respectively. One possible interpretation is that any form of inequity represents a norm violation, but that important differences between AI and DI emerge from an asymmetric involvement of status concerns. PMID:22701414

  2. Income inequality in today’s China

    PubMed Central

    Xie, Yu; Zhou, Xiang

    2014-01-01

    Using multiple data sources, we establish that China's income inequality since 2005 has reached very high levels, with the Gini coefficient in the range of 0.53–0.55. Analyzing comparable survey data collected in 2010 in China and the United States, we examine social determinants that help explain China’s high income inequality. Our results indicate that a substantial part of China’s high income inequality is due to regional disparities and the rural-urban gap. The contributions of these two structural forces are particularly strong in China, but they play a negligible role in generating the overall income inequality in the United States, where individual-level and family-level income determinants, such as family structure and race/ethnicity, play a much larger role. PMID:24778237

  3. Geometric-Harmonic convexity and integral inequalities

    NASA Astrophysics Data System (ADS)

    Akdemir, Ahmet Ocak; Yalçin, Abdüllatif; Polat, Fatma; Kavurmaci-Önalan, Havva

    2016-04-01

    In this paper, some new integral inequalities have been proved for functions whose absolute value of derivatives are GH-convex functions by using integral equalities that have been obtained previously.

  4. Inequality, income, and poverty: comparative global evidence.

    PubMed

    Fosu, Augustin Kwasi

    2010-01-01

    Objectives. The study seeks to provide comparative global evidence on the role of income inequality, relative to income growth, in poverty reduction.Methods. An analysis-of-covariance model is estimated using a large global sample of 1980–2004 unbalanced panel data, with the headcount measure of poverty as the dependent variable, and the Gini coefficient and PPP-adjusted mean income as explanatory variables. Both random-effects and fixed-effects methods are employed in the estimation.Results. The responsiveness of poverty to income is a decreasing function of inequality, and the inequality elasticity of poverty is actually larger than the income elasticity of poverty. Furthermore, there is a large variation across regions (and countries) in the relative effects of inequality on poverty.Conclusion. Income distribution plays a more important role than might be traditionally acknowledged in poverty reduction, though this importance varies widely across regions and countries. PMID:21125764

  5. Schooling and Inequality from Generation to Generation

    ERIC Educational Resources Information Center

    Bowles, Samuel

    1972-01-01

    Shows that substantial inequality of economic opportunity exists in the U.S. and that the educational system is a major vehicle for the transmission of economic status from one generation to the next. (RJ)

  6. Bell inequalities resistant to detector inefficiency

    SciTech Connect

    Massar, Serge; Pironio, Stefano; Roland, Jeremie; Gisin, Bernard

    2002-11-01

    We derive both numerically and analytically Bell inequalities and quantum measurements that present enhanced resistance to detector inefficiency. In particular, we describe several Bell inequalities which appear to be optimal with respect to inefficient detectors for small dimensionality d=2,3,4 and two or more measurement settings at each side. We also generalize the family of Bell inequalities described by Collins et al. [Phys. Rev. Lett. 88, 040404 (2002)] to take into account the inefficiency of detectors. In addition, we consider the possibility for pairs of entangled particles to be produced with probability less than 1. We show that when the pair production probability is small, one should in general use different Bell inequalities than when the pair production probability is high.

  7. Should we worry about income inequality?

    PubMed

    Wade, Robert Hunter

    2006-01-01

    Liberals (in the European sense) argue that a liberal free-market economic policy regime-nationally and globally-is good for economic growth and poverty reduction and for keeping income inequality within tolerable limits. Second, they argue that substantial income inequality is desirable because of its good effects on other things, notably incentives, innovation, and panache; and conversely, they dismiss concerns about growing inequality as "the politics of envy." Third, they argue that the core liberal theory of capitalist political economy satisfactorily explains the central tendencies in the role of the state in advanced capitalist economies. This essay challenges all three arguments on both conceptual and empirical grounds. It then suggests why the arguments are nevertheless widely accepted, proposes criteria for deciding how much inequality is fair, and ends by suggesting ways for achieving higher salience for income redistribution (downwards) in political agendas. PMID:16878393

  8. Evolutionary problems driven by variational inequalities

    NASA Astrophysics Data System (ADS)

    Liu, Zhenhai; Zeng, Shengda; Motreanu, Dumitru

    2016-05-01

    In this paper we introduce the differential system obtained by mixing an evolution equation and a variational inequality ((EEVI), for short). First, by using KKM theorem and monotonicity arguments, we prove the superpositional measurability and upper semicontinuity for the solution set of a general variational inequality. Then we establish that the solution set of (EEVI) is nonempty and compact. Our approach is based on the theory of semigroups, Filippov implicit function lemma and fixed point theory for set-valued mappings.

  9. Inequalities in health and social policy.

    PubMed

    Zieliński, Andrzej

    2015-01-01

    WHO and the European Commission impart great importance to promoting activities aimed at reducing inequalities in health. The article raised methodological problems of studies on the causes of inequalities in health. Author draws attention to the need for field studies focused on comparing well-specified population groups in order to achieve greater accuracy of studies to obtain preventive actions better fit to the specific needs of a given population. He also indicates the difficulties related to the comparisons made on an international scale due to the large number of variables that could interfere with investigated exposure. A significant part of the article is devoted to the interpretation of the measurement of poverty and the relationship between economic inequality and inequities in health. The author points out that there are no simple relations in this area, but the impact of economic inequality is particularly pronounced where inequalities in income of families bring large fractions of a society below the threshold of poverty. PMID:27139342

  10. Clausius inequality beyond the weak-coupling limit: the quantum Brownian oscillator.

    PubMed

    Kim, Ilki; Mahler, Günter

    2010-01-01

    We consider a quantum linear oscillator coupled at an arbitrary strength to a bath at an arbitrary temperature. We find an exact closed expression for the oscillator density operator. This state is noncanonical but can be shown to be equivalent to that of an uncoupled linear oscillator at an effective temperature T*(eff) with an effective mass and an effective spring constant. We derive an effective Clausius inequality deltaQ*(eff)< or =T*(eff)dS , where deltaQ*(eff) is the heat exchanged between the effective (weakly coupled) oscillator and the bath, and S represents a thermal entropy of the effective oscillator, being identical to the von-Neumann entropy of the coupled oscillator. Using this inequality (for a cyclic process in terms of a variation of the coupling strength) we confirm the validity of the second law. For a fixed coupling strength this inequality can also be tested for a process in terms of a variation of either the oscillator mass or its spring constant. Then it is never violated. The properly defined Clausius inequality is thus more robust than assumed previously. PMID:20365317