Exploring stochasticity and imprecise knowledge based on linear inequality constraints.
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.
Linear mixed effects models under inequality constraints with applications.
Farnan, Laura; Ivanova, Anastasia; Peddada, Shyamal D
2014-01-01
Constraints arise naturally in many scientific experiments/studies such as in, epidemiology, biology, toxicology, etc. and often researchers ignore such information when analyzing their data and use standard methods such as the analysis of variance (ANOVA). Such methods may not only result in a loss of power and efficiency in costs of experimentation but also may result poor interpretation of the data. In this paper we discuss constrained statistical inference in the context of linear mixed effects models that arise naturally in many applications, such as in repeated measurements designs, familial studies and others. We introduce a novel methodology that is broadly applicable for a variety of constraints on the parameters. Since in many applications sample sizes are small and/or the data are not necessarily normally distributed and furthermore error variances need not be homoscedastic (i.e. heterogeneity in the data) we use an empirical best linear unbiased predictor (EBLUP) type residual based bootstrap methodology for deriving critical values of the proposed test. Our simulation studies suggest that the proposed procedure maintains the desired nominal Type I error while competing well with other tests in terms of power. We illustrate the proposed methodology by re-analyzing a clinical trial data on blood mercury level. The methodology introduced in this paper can be easily extended to other settings such as nonlinear and generalized regression models.
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.
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.
Inequality constraint in least-square inversion of geophysical data
Kim, Hee Joon; Song, Yoonho; Lee, Ki Ha
1998-06-01
This paper presents a simple, generalized parameter constraint using a priori information to obtain a stable inverse of geophysical data. In the constraint the a priori information can be expressed by two limits: lower and upper bounds. This is a kind of inequality constraint, which is usually employed in linear programming. In this paper, we have derived this parameter constraint as a generalized version of positiveness constraint of parameter, which is routinely used in the inversion of electrical and EM data. However, the two bounds are not restricted to positive values. The width of two bounds reflects the reliability of ground information, which is obtained through well logging and surface geology survey. The effectiveness and convenience of this inequality constraint is demonstrated through the smoothness-constrained inversion of synthetic magnetotelluric data.
Resolving manipulator redundancy under inequality constraints
Cheng, F.T.; Chen, T.H.; Sun, Y.Y. . Dept. of Electrical Engineering)
1994-02-01
Due to hardware limitations, physical constraints such as joint rate bounds, joint angle limits, and joint torque constraints always exist. In this paper, these constraints are considered into the general formulation of the redundant inverse kinematic problem. To take these physical constraints into account, the computationally efficient Compact Quadratic Programming (QP) method is formed to resolve the constrained kinematic redundancy problem. In addition, the Compact-Inverse QP method is also formulated to remedy the unescapable singularity problem with inequality constraints. Two examples are given to demonstrate the generality and superiority of these two methods: to eliminate the drift phenomenon caused by self motion and to remedy saturation-type nonlinearity problem.
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.
An Aggregate Constraint Method for Inequality-constrained Least Squares Problems
NASA Astrophysics Data System (ADS)
Peng, Junhuan; Zhang, Hongping; Shong, Suli; Guo, Chunxi
2006-03-01
The inequality-constrained least squares (ICLS) problem can be solved by the simplex algorithm of quadratic programming. The ICLS problem may also be reformulated as a Bayesian problem and solved by using the Bayesian principle. This paper proposes using the aggregate constraint method of non-linear programming to solve the ICLS problem by converting many inequality constraints into one equality constraint, which is a basic augmented Lagrangean algorithm for deriving the solution to equality-constrained non-linear programming problems. Since the new approach finds the active constraints, we can derive the approximate algorithm-dependent statistical properties of the solution. As a result, some conclusions about the superiority of the estimator can be approximately made. Two simulated examples are given to show how to compute the approximate statistical properties and to show that the reasonable inequality constraints can improve the results of geodetic network with an ill-conditioned normal matrix.
Least absolute value state estimation with equality and inequality constraints
Abur, A. ); Celik, M.K. )
1993-05-01
A least absolute value (LAV) state estimator, which can handle both equality and inequality constraints on measurements, is developed. It is shown that, the use of equality constraints will actually reduce the number of Simplex iterations and thus the overall cpu time. The constraints can be used to enhance the reliability of the state estimator without affecting the computational efficiency of the estimator. The developed estimation program is tested using 14 through 1,000 bus power systems.
Treatment of inequality constraints in power system state estimation
Clements, K.A.; Davis, P.W.; Frey, K.D.
1995-05-01
A new formulation of the power system state estimation problem and a new solution technique are presented. The formulation allows for inequality constraints such as Var limits on generators and transformer tap ratio limits. In addition, unmeasured loads can be modeled as unknown but bounded quantities. The solution technique is an interior point method that uses logarithmic barrier functions to treat the inequality constraints. The authors describe computational issues arising in the implementation of the algorithm. Numerical results are given for systems ranging in size from six to 118 buses.
Handling inequality constraints in continuous nonlinear global optimization
Wang, Tao; Wah, B.W.
1996-12-31
In this paper, we present a new method to handle inequality constraints and apply it in NOVEL (Nonlinear Optimization via External Lead), a system we have developed for solving constrained continuous nonlinear optimization problems. In general, in applying Lagrange-multiplier methods to solve these problems, inequality constraints are first converted into equivalent equality constraints. One such conversion method adds a slack variable to each inequality constraint in order to convert it into an equality constraint. The disadvantage of this conversion is that when the search is inside a feasible region, some satisfied constraints may still pose a non-zero weight in the Lagrangian function, leading to possible oscillations and divergence when a local optimum lies on the boundary of a feasible region. We propose a new conversion method called the MaxQ method such that all satisfied constraints in a feasible region always carry zero weight in the Lagrange function; hence, minimizing the Lagrange function in a feasible region always leads to local minima of the objective function. We demonstrate that oscillations do not happen in our method. We also propose methods to speed up convergence when a local optimum lies on the boundary of a feasible region. Finally, we show improved experimental results in applying our proposed method in NOVEL on some existing benchmark problems and compare them to those obtained by applying the method based on slack variables.
Linear determining equations for differential constraints
Kaptsov, O V
1998-12-31
A construction of differential constraints compatible with partial differential equations is considered. Certain linear determining equations with parameters are used to find such differential constraints. They generalize the classical determining equations used in the search for admissible Lie operators. As applications of this approach equations of an ideal incompressible fluid and non-linear heat equations are discussed.
Inequality in Human Capital and Endogenous Credit Constraints.
Hai, Rong; Heckman, James J
2017-04-01
This paper investigates the determinants of inequality in human capital with an emphasis on the role of the credit constraints. We develop and estimate a model in which individuals face uninsured human capital risks and invest in education, acquire work experience, accumulate assets and smooth consumption. Agents can borrow from the private lending market and from government student loan programs. The private market credit limit is explicitly derived by extending the natural borrowing limit of Aiyagari (1994) to incorporate endogenous labor supply, human capital accumulation, psychic costs of working, and age. We quantify the effects of cognitive ability, noncognitive ability, parental education, and parental wealth on educational attainment, wages, and consumption. We conduct counterfactual experiments with respect to tuition subsidies and enhanced student loan limits and evaluate their effects on educational attainment and inequality. We compare the performance of our model with an influential ad hoc model in the literature with education-specific fixed loan limits. We find evidence of substantial life cycle credit constraints that affect human capital accumulation and inequality. The constrained fall into two groups: those who are permanently poor over their lifetimes and a group of well-endowed individuals with rising high levels of acquired skills who are constrained early in their life cycles. Equalizing cognitive and noncognitive ability has dramatic effects on inequality. Equalizing parental backgrounds has much weaker effects. Tuition costs have weak effects on inequality.
Interpolation method taking into account inequality constraints. I. Methodology
Dubrule, O.; Kostov, C.
1986-01-01
Several kinds of data can provide information about a variable measured on a one- or two-dimensional space; at some points, the value is known to be equal to a certain number. At other points, the only information may be that the variable is greater or smaller than a given value. The theory of splines provides interpolating functions that can take into account both equality and inequality data. These interpolating functions are presented. The parallel between splines and kriging is reviewed, using the formalism of dual kriging. Coefficients of dual kriging can be obtained directly by minimizing a quadratic form. By adding some inequality constraints to this minimization, an interpolating function may be calculated which takes into account inequality data and is more general than a spline. The method is illustrated by some simple one-dimensional examples.
Interpolation method taking into account inequality constraints. II. Practical approach
Kostov, C.; Dubrule, O.
1986-01-01
Common features of models for interpolation, consistent with a finite number of inequality constraints on the range of values of a variable z, are discussed. A method based on constrained quadratic minimization yielding kriging estimates when no constraints exist, is presented. A computationally efficient formulation of quadratic minimization is obtained by using results on duality in quadratic programming. Relevant properties of the optimal interpolator are derived in a simple, self-contained way. The method is applied to mapping of horizon depth and estimation of thickness of an oil-bearing formation.
Linear predictive control with state variable constraints
NASA Astrophysics Data System (ADS)
Bdirina, K.; Djoudi, D.; Lagoun, M.
2012-11-01
While linear model predictive control is popular since the 70s of the past century, the 90s have witnessed a steadily increasing attention from control theoretists as well as control practitioners in the area of model predictive control (MPC). The practical interest is driven by the fact that today's processes need to be operated under tighter performance specifications. At the same time more and more constraints, stemming for example from environmental and safety considerations, need to besatisfied. Often these demands can only be met when process constraints are explicitly considered in the controller. Predictive control with constraints appears to be a well suited approach for this kind of problems. In this paper the basic principle of MPC with constraints is reviewed and some of the theoretical, computational, and implementation aspects of MPC are discussed. Furthermore the MPC with constraints was applied to linear example.
Wang, Xinwei; Peng, Haijun; Zhang, Sheng; Chen, Biaosong; Zhong, Wanxie
2017-03-16
A symplectic pseudospectral method based on the dual variational principle and the quasilinearization method is proposed and is successfully applied to solve nonlinear optimal control problems with inequality constraints in this paper. Nonlinear optimal control problem is firstly converted into a series of constraint linear-quadratic optimal control problems with the help of quasilinearization techniques. Then a symplectic pseudospectral method based on dual variational principle for solving the converted constrained linear-quadratic optimal control problems is developed. In the proposed method, inequality constraints which can be functions of pure state, pure control and mixed state-control are transformed into equality constraints with the help of parameteric variables. After that, state variables, costate variables and parametric variables are interpolated locally at Legendre-Gauss-Lobatto points. Finally, based on the parametric variational principle and complementary conditions, the converted problem is transformed into a standard linear complementary problem which can be solved easily. Numerical examples show that the proposed method is of high accuracy and efficiency.
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.
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.
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.
Ensemble Kalman filtering in presence of inequality constraints
NASA Astrophysics Data System (ADS)
van Leeuwen, P. J.
2009-04-01
Kalman filtering is presence of constraints is an active area of research. Based on the Gaussian assumption for the probability-density functions, it looks hard to bring in extra constraints in the formalism. On the other hand, in geophysical systems we often encounter constraints related to e.g. the underlying physics or chemistry, which are violated by the Gaussian assumption. For instance, concentrations are always non-negative, model layers have non-negative thickness, and sea-ice concentration is between 0 and 1. Several methods to bring inequality constraints into the Kalman-filter formalism have been proposed. One of them is probability density function (pdf) truncation, in which the Gaussian mass from the non-allowed part of the variables is just equally distributed over the pdf where the variables are alolwed, as proposed by Shimada et al. 1998. However, a problem with this method is that the probability that e.g. the sea-ice concentration is zero, is zero! The new method proposed here does not have this drawback. It assumes that the probability-density function is a truncated Gaussian, but the truncated mass is not distributed equally over all allowed values of the variables, but put into a delta distribution at the truncation point. This delta distribution can easily be handled with in Bayes theorem, leading to posterior probability density functions that are also truncated Gaussians with delta distributions at the truncation location. In this way a much better representation of the system is obtained, while still keeping most of the benefits of the Kalman-filter formalism. In the full Kalman filter the formalism is prohibitively expensive in large-scale systems, but efficient implementation is possible in ensemble variants of the kalman filter. Applications to low-dimensional systems and large-scale systems will be discussed.
Optimization problems with quasi-variational inequality constraints
Outrata, J.
1994-12-31
The main aim of the contribution is to propose a numerical method for the optimization problems with parameter-dependent Quasi-Variational Inequalities (QVI) or Implicit Complementarity Problems (ICP) as side constraints. Thereby we confine ourselves to the simpler case in which the solutions of QVI (ICP) are unique (or at least locally unique) and depend on the parameter in a lipschitzian way. In the first part we state the problem and give some motivating examples coming from mechanics. The second part deals with the numerical solution of QVI (ICP) for fixed values of the parameter by a nonsmooth variant of the Newton method, which has shown a surprising effectiveness in the applications being considered. In particular, we show that the appropriate operators are semismooth and discuss the nonsingularity condition. The third part is devoted to our optimization problems which are cast in such a way that the bundle techniques from nonsmooth optimization can be applied. To compute the needed {open_quotes}subgradient{close_quotes} information, we characterize the maps, assigning to the single admissible values of the parameter the corresponding solution of the QVI, by generalized Jacobians. As a test example, the optimal covering problem from shape optimization is taken, in which the rigid obstacle is replaced by an elastic one.
Solving of variational inequalities by reducing to the linear complementarity problem
NASA Astrophysics Data System (ADS)
Gabidullina, Z. R.
2016-11-01
We study the variational inequalities closely connected with the linear separation problem of the convex polyhedrain the Euclidean space. For solving of these inequalities, we apply the reduction to the linear complementarity problem. Such reduction allows one to solve the variational inequalities with the help of the Matlab software package.
NASA Astrophysics Data System (ADS)
Wagner, Daniel Robert
Linear matrix inequalities and convex optimization techniques have become popular tools to solve nontrivial problems in the field of adaptive control. Specifically, the stability of adaptive control laws in the presence of actuator dynamics remains as an important open control problem. In this thesis, we present a linear matrix inequalities-based hedging approach and evaluate it for model reference adaptive control of an uncertain dynamical system in the presence of actuator dynamics. The ideal reference dynamics are modified such that the hedging approach allows the correct adaptation without being hindered by the presence of actuator dynamics. The hedging approach is first generalized such that two cases are considered where the actuator output and control effectiveness are known and unknown. We then show the stability of the closed-loop dynamical system using Lyapunov based stability analysis tools and propose a linear matrix inequality-based framework for the computation of the minimum allowable actuator bandwidth limits such that the closed-loop dynamical system remains stable. The results of the linear matrix inequality-based heading approach are then generalized to multiactuator systems with a new linear matrix inequality condition. The minimum actuator bandwidth solutions for closed-loop system stability are theoretically guaranteed to exist in a convex set with a partially convex constraint and then solved numerically using an algorithm in the case where there are multiple actuators. Finally, the efficacy of the results contained in this thesis are demonstrated using several illustrative numerical examples.
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.
Solving linear inequalities in a least squares sense
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.
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.
Handschin, E.; Langer, M.; Kliokys, E.
1995-12-31
The possibility of power system state estimation with non-traditional measurement configuration is investigated. It is assumed that some substations are equipped with current magnitude measurements. Unique state estimation is possible, in such a situation, if currents are combined with voltage or power measurements and inequality constraints on node power injections are taken into account. The state estimation algorithm facilitating the efficient incorporation of inequality constraints is developed using an interior point optimization method. Simulation results showing the performance of the algorithm are presented. The method can be used for state estimation in medium voltage subtransmission and distribution networks.
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.
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.
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.
Dual MIMU Pedestrian Navigation by Inequality Constraint Kalman Filtering.
Shi, Wei; Wang, Yang; Wu, Yuanxin
2017-02-22
The foot-mounted inertial navigation system is an important method of pedestrian navigation as it, in principle, does not rely any external assistance. A real-time range decomposition constraint method is proposed in this paper to combine the information of dual foot-mounted inertial navigation systems. It is well known that low-cost inertial pedestrian navigation aided with both ZUPT (zero velocity update) and the range decomposition constraint performs better than those in their own respective methods. This paper recommends that the separation distance between the position estimates of the two foot-mounted inertial navigation systems be restricted by an ellipsoidal constraint that relates to the maximum step length and the leg height. The performance of the proposed method is studied by utilizing experimental data, and the results indicate that the method can effectively correct the dual navigation systems' position over the traditional spherical constraint.
Dual MIMU Pedestrian Navigation by Inequality Constraint Kalman Filtering
Shi, Wei; Wang, Yang; Wu, Yuanxin
2017-01-01
The foot-mounted inertial navigation system is an important method of pedestrian navigation as it, in principle, does not rely any external assistance. A real-time range decomposition constraint method is proposed in this paper to combine the information of dual foot-mounted inertial navigation systems. It is well known that low-cost inertial pedestrian navigation aided with both ZUPT (zero velocity update) and the range decomposition constraint performs better than those in their own respective methods. This paper recommends that the separation distance between the position estimates of the two foot-mounted inertial navigation systems be restricted by an ellipsoidal constraint that relates to the maximum step length and the leg height. The performance of the proposed method is studied by utilizing experimental data, and the results indicate that the method can effectively correct the dual navigation systems’ position over the traditional spherical constraint. PMID:28241448
Non-overlapping domain decomposition method for a variational inequality with gradient constraints
NASA Astrophysics Data System (ADS)
Lapin, A.; Laitinen, E.; Lapin, S.
2016-11-01
Non-overlapping domain decomposition method is applied to a variational inequality with nonlinear diffusion-convection operator and gradient constraints. The method is based on the initial approximation of the problem and its subsequent splitting into subproblems. For the resulting constrained saddle point problem block relaxation-Uzawa iterative solution method is applied.
Virasoro constraints and polynomial recursion for the linear Hodge integrals
NASA Astrophysics Data System (ADS)
Guo, Shuai; Wang, Gehao
2016-11-01
The Hodge tau-function is a generating function for the linear Hodge integrals. It is also a tau-function of the KP hierarchy. In this paper, we first present the Virasoro constraints for the Hodge tau-function in the explicit form of the Virasoro equations. The expression of our Virasoro constraints is simply a linear combination of the Virasoro operators, where the coefficients are restored from a power series for the Lambert W function. Then, using this result, we deduce a simple version of the Virasoro constraints for the linear Hodge partition function, where the coefficients are restored from the Gamma function. Finally, we establish the equivalence relation between the Virasoro constraints and polynomial recursion formula for the linear Hodge integrals.
Virasoro constraints and polynomial recursion for the linear Hodge integrals
NASA Astrophysics Data System (ADS)
Guo, Shuai; Wang, Gehao
2017-04-01
The Hodge tau-function is a generating function for the linear Hodge integrals. It is also a tau-function of the KP hierarchy. In this paper, we first present the Virasoro constraints for the Hodge tau-function in the explicit form of the Virasoro equations. The expression of our Virasoro constraints is simply a linear combination of the Virasoro operators, where the coefficients are restored from a power series for the Lambert W function. Then, using this result, we deduce a simple version of the Virasoro constraints for the linear Hodge partition function, where the coefficients are restored from the Gamma function. Finally, we establish the equivalence relation between the Virasoro constraints and polynomial recursion formula for the linear Hodge integrals.
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…
Fuzzy attitude control of solar sail via linear matrix inequalities
NASA Astrophysics Data System (ADS)
Baculi, Joshua; Ayoubi, Mohammad A.
2017-09-01
This study presents a fuzzy tracking controller based on the Takagi-Sugeno (T-S) fuzzy model of the solar sail. First, the T-S fuzzy model is constructed by linearizing the existing nonlinear equations of motion of the solar sail. Then, the T-S fuzzy model is used to derive the state feedback controller gains for the Twin Parallel Distributed Compensation (TPDC) technique. The TPDC tracks and stabilizes the attitude of the solar sail to any desired state in the presence of parameter uncertainties and external disturbances while satisfying actuator constraints. The performance of the TPDC is compared to a PID controller that is tuned using the Ziegler-Nichols method. Numerical simulation shows the TPDC outperforms the PID controller when stabilizing the solar sail to a desired state.
Analysis of junior high school students' attempt to solve a linear inequality problem
NASA Astrophysics Data System (ADS)
Taqiyuddin, Muhammad; Sumiaty, Encum; Jupri, Al
2017-08-01
Linear inequality is one of fundamental subjects within junior high school mathematics curricula. Several studies have been conducted to asses students' perform on linear inequality. However, it can hardly be found that linear inequality problems are in the form of "ax + b < dx + e" with "a, d ≠ 0", and "a ≠ d" as it can be seen on the textbook used by Indonesian students and several studies. This condition leads to the research questions concerning students' attempt on solving a simple linear inequality problem in this form. In order to do so, the written test was administered to 58 students from two schools in Bandung followed by interviews. The other sources of the data are from teachers' interview and mathematics books used by students. After that, the constant comparative method was used to analyse the data. The result shows that the majority approached the question by doing algebraic operations. Interestingly, most of them did it incorrectly. In contrast, algebraic operations were correctly used by some of them. Moreover, the others performed expected-numbers solution, rewriting the question, translating the inequality into words, and blank answer. Furthermore, we found that there is no one who was conscious of the existence of all-numbers solution. It was found that this condition is reasonably due to how little the learning components concern about why a procedure of solving a linear inequality works and possibilities of linear inequality solution.
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.
Linear-constraint wavefront control for exoplanet coronagraphic imaging systems
NASA Astrophysics Data System (ADS)
Sun, He; Eldorado Riggs, A. J.; Kasdin, N. Jeremy; Vanderbei, Robert J.; Groff, Tyler Dean
2017-01-01
A coronagraph is a leading technology for achieving high-contrast imaging of exoplanets in a space telescope. It uses a system of several masks to modify the diffraction and achieve extremely high contrast in the image plane around target stars. However, coronagraphic imaging systems are very sensitive to optical aberrations, so wavefront correction using deformable mirrors (DMs) is necessary to avoid contrast degradation in the image plane. Electric field conjugation (EFC) and Stroke minimization (SM) are two primary high-contrast wavefront controllers explored in the past decade. EFC minimizes the average contrast in the search areas while regularizing the strength of the control inputs. Stroke minimization calculates the minimum DM commands under the constraint that a target average contrast is achieved. Recently in the High Contrast Imaging Lab at Princeton University (HCIL), a new linear-constraint wavefront controller based on stroke minimization was developed and demonstrated using numerical simulation. Instead of only constraining the average contrast over the entire search area, the new controller constrains the electric field of each single pixel using linear programming, which could led to significant increases in speed of the wavefront correction and also create more uniform dark holes. As a follow-up of this work, another linear-constraint controller modified from EFC is demonstrated theoretically and numerically and the lab verification of the linear-constraint controllers is reported. Based on the simulation and lab results, the pros and cons of linear-constraint controllers are carefully compared with EFC and stroke minimization.
A Constraint Generation Approach to Learning Stable Linear Dynamical Systems
2008-01-01
and † denotes the Moore - Penrose inverse . Eq. (3) asks Â to minimize the error in predicting the state at time t + 1 from the state at time t. Given...A Constraint Generation Approach to Learning Stable Linear Dynamical Systems Sajid M. Siddiqi Byron Boots Geoffrey J. Gordon January 2008...REPORT DATE JAN 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE A Constraint Generation Approach to Learning
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.
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.
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.
Diffusion LMS for Multitask Problems With Local Linear Equality Constraints
NASA Astrophysics Data System (ADS)
Nassif, Roula; Richard, Cedric; Ferrari, Andre; Sayed, Ali H.
2017-10-01
We consider distributed multitask learning problems over a network of agents where each agent is interested in estimating its own parameter vector, also called task, and where the tasks at neighboring agents are related according to a set of linear equality constraints. Each agent possesses its own convex cost function of its parameter vector and a set of linear equality constraints involving its own parameter vector and the parameter vectors of its neighboring agents. We propose an adaptive stochastic algorithm based on the projection gradient method and diffusion strategies in order to allow the network to optimize the individual costs subject to all constraints. Although the derivation is carried out for linear equality constraints, the technique can be applied to other forms of convex constraints. We conduct a detailed mean-square-error analysis of the proposed algorithm and derive closed-form expressions to predict its learning behavior. We provide simulations to illustrate the theoretical findings. Finally, the algorithm is employed for solving two problems in a distributed manner: a minimum-cost flow problem over a network and a space-time varying field reconstruction problem.
Linear patterning of mesenchymal condensations is modulated by geometric constraints.
Klumpers, Darinka D; Mao, Angelo S; Smit, Theo H; Mooney, David J
2014-06-06
The development of the vertebral column starts with the formation of a linear array of mesenchymal condensations, forming the blueprint for the eventual alternating pattern of bone and cartilage. Despite growing insight into the molecular mechanisms of morphogenesis, the impact of the physical aspects of the environment is not well understood. We hypothesized that geometric boundary conditions may play a pivotal role in the linear patterning of condensations, as neighbouring tissues provide physical constraints to the cell population. To study the process of condensation and the patterning thereof under tightly controlled geometric constraints, we developed a novel in vitro model that combines micropatterning with the established micromass assay. The spacing and alignment of condensations changed with the width of the cell adhesive patterns, a phenomenon that could not be explained by cell availability alone. Moreover, the extent of chondrogenic commitment was increased on substrates with tighter geometric constraints. When the in vivo pattern of condensations was investigated in the developing vertebral column of chicken embryos, the measurements closely fit into the quantitative relation between geometric constraints and inter-condensation distance found in vitro. Together, these findings suggest a potential role of geometric constraints in skeletal patterning in a cellular process of self-organization.
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…
Linear perturbation constraints on multi-coupled dark energy
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
Gender, inequality and Depo-Provera: Constraints on reproductive choice in Nicaragua.
Yarris, Kristin Elizabeth; Dent, Nicolette Jeannette
2017-04-01
This article examines the sociocultural determinants of Nicaraguan women's use of Depo-Provera as a means of contraception. The prevalence of Depo-Provera in Nicaragua is high and increasing compared to other Central American countries. Drawing on data from structured interviews with 87 women and from focus groups with 32 women, we show how women's preference for Depo is shaped by both gendered inequalities and socioeconomic constraints. We employ basic statistical tests to analyse correlations between women's marital status and socioeconomic status (SES) with contraceptive use. Our statistical findings show significant associations between use of Depo and both marital status and SES, such that women who are married or in conjugal unions and women with lower SES are more likely to use Depo. To help explain women's use of Depo-Provera in Nicaragua, we situate our findings within the context of gender, culture, and power, reviewing the contested history of Depo-Provera in the developing world and dynamics of gender inequality, which constrain women's contraceptive choices. We conclude with suggestions for reproductive health programming in Nicaragua and beyond, arguing that gender equity and addressing socioeconomic barriers to family planning remain priorities for the achievement of global reproductive health.
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.
Xia, Youshen; Feng, Gang; Wang, Jun
2008-08-01
This paper presents a novel recurrent neural network for solving nonlinear optimization problems with inequality constraints. Under the condition that the Hessian matrix of the associated Lagrangian function is positive semidefinite, it is shown that the proposed neural network is stable at a Karush-Kuhn-Tucker point in the sense of Lyapunov and its output trajectory is globally convergent to a minimum solution. Compared with variety of the existing projection neural networks, including their extensions and modification, for solving such nonlinearly constrained optimization problems, it is shown that the proposed neural network can solve constrained convex optimization problems and a class of constrained nonconvex optimization problems and there is no restriction on the initial point. Simulation results show the effectiveness of the proposed neural network in solving nonlinearly constrained optimization problems.
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.
Robust control of uncertain multi-inventory systems via linear matrix inequality
NASA Astrophysics Data System (ADS)
Bauso, Dario; Giarré, Laura; Pesenti, Raffaele
2010-08-01
We consider a continuous time linear multi-inventory system with unknown demands bounded within ellipsoids and controls bounded within ellipsoids or polytopes. We address the problem of ε-stabilising the inventory since this implies some reduction of the inventory costs. The main results are certain conditions under which ε-stabilisability is possible through a saturated linear state feedback control. All the results are based on a linear matrix inequalities approach and on some recent techniques for the modelling and analysis of polytopic systems with saturations. Numerical simulations are provided.
Linear correlates in the speech signal: the orderly output constraint.
Sussman, H M; Fruchter, D; Hilbert, J; Sirosh, J
1998-04-01
Neuroethological investigations of mammalian and avian auditory systems have documented species-specific specializations for processing complex acoustic signals that could, if viewed in abstract terms, have an intriguing and striking relevance for human speech sound categorization and representation. Each species forms biologically relevant categories based on combinatorial analysis of information-bearing parameters within the complex input signal. This target article uses known neural models from the mustached bat and barn owl to develop, by analogy, a conceptualization of human processing of consonant plus vowel sequences that offers a partial solution to the noninvariance dilemma--the nontransparent relationship between the acoustic waveform and the phonetic segment. Critical input sound parameters used to establish species-specific categories in the mustached bat and barn owl exhibit high correlation and linearity due to physical laws. A cue long known to be relevant to the perception of stop place of articulation is the second formant (F2) transition. This article describes an empirical phenomenon--the locus equations--that describes the relationship between the F2 of a vowel and the F2 measured at the onset of a consonant-vowel (CV) transition. These variables, F2 onset and F2 vowel within a given place category, are consistently and robustly linearly correlated across diverse speakers and languages, and even under perturbation conditions as imposed by bite blocks. A functional role for this category-level extreme correlation and linearity (the "orderly output constraint") is hypothesized based on the notion of an evolutionarily conserved auditory-processing strategy. High correlation and linearity between critical parameters in the speech signal that help to cue place of articulation categories might have evolved to satisfy a preadaptation by mammalian auditory systems for representing tightly correlated, linearly related components of acoustic signals.
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
Qin, Sitian; Yang, Xiudong; Xue, Xiaoping; Song, Jiahui
2016-05-24
Pseudoconvex optimization problem, as an important nonconvex optimization problem, plays an important role in scientific and engineering applications. In this paper, a recurrent one-layer neural network is proposed for solving the pseudoconvex optimization problem with equality and inequality constraints. It is proved that from any initial state, the state of the proposed neural network reaches the feasible region in finite time and stays there thereafter. It is also proved that the state of the proposed neural network is convergent to an optimal solution of the related problem. Compared with the related existing recurrent neural networks for the pseudoconvex optimization problems, the proposed neural network in this paper does not need the penalty parameters and has a better convergence. Meanwhile, the proposed neural network is used to solve three nonsmooth optimization problems, and we make some detailed comparisons with the known related conclusions. In the end, some numerical examples are provided to illustrate the effectiveness of the performance of the proposed neural network.
Optimized constraints for the linearized geoacoustic inverse problem.
Ballard, Megan S; Becker, Kyle M
2011-02-01
A geoacoustic inversion scheme to estimate the depth-dependent sound speed characteristics of the shallow-water waveguide is presented. The approach is based on the linearized perturbative technique developed by Rajan et al. [J. Acoust. Soc. Am. 82, 998-1017 (1987)]. This method is applied by assuming a background starting model for the environment that includes both the water column and the seabed. Typically, the water column properties are assumed to be known and held fixed in the inversion. Successful application of the perturbative inverse technique lies in handling issues of stability and uniqueness associated with solving a discrete ill-posed problem. Conventionally, such problems are regularized, a procedure which results in a smooth solution. Past applications of this inverse technique have been restricted to cases for which the water column sound speed profile was known and sound speed in the seabed could be approximated by a smooth profile. In this work, constraints that are better suited to specific aspects of the geoacoustic inverse problem are applied. These techniques expand on the original application of the perturbative inverse technique by including the water column sound speed profile in the solution and by allowing for discontinuities in the seabed sound speed profile.
Linear constraint minimum variance beamformer functional magnetic resonance inverse imaging.
Lin, Fa-Hsuan; Witzel, Thomas; Zeffiro, Thomas A; Belliveau, John W
2008-11-01
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.
NASA Astrophysics Data System (ADS)
Frick, K.; Grasmair, M.
2012-10-01
We study the application of the augmented Lagrangian method to the solution of linear ill-posed problems. Previously, linear convergence rates with respect to the Bregman distance have been derived under the classical assumption of a standard source condition. Using the method of variational inequalities, we extend these results in this paper to convergence rates of lower order, both for the case of an a priori parameter choice and an a posteriori choice based on Morozov’s discrepancy principle. In addition, our approach allows the derivation of convergence rates with respect to distance measures different from the Bregman distance. As a particular application, we consider sparsity promoting regularization, where we derive a range of convergence rates with respect to the norm under the assumption of restricted injectivity in conjunction with generalized source conditions of Hölder type.
NASA Astrophysics Data System (ADS)
Neitzel, Ira; Prüfert, Uwe; Slawig, Thomas
2009-03-01
In Neitzel et al. (Strategies for time-dependent PDE control using an integrated modeling and simulation environment. Part one: problems without inequality constraints. Technical Report 408, Matheon, Berlin, 2007) we have shown how time-dependent optimal control for partial differential equations can be realized in a modern high-level modeling and simulation package. In this article we extend our approach to (state) constrained problems. "Pure" state constraints in a function space setting lead to non-regular Lagrange multipliers (if they exist), i.e. the Lagrange multipliers are in general Borel measures. This will be overcome by different regularization techniques. To implement inequality constraints, active set methods and barrier methods are widely in use. We show how these techniques can be realized in a modeling and simulation package. We implement a projection method based on active sets as well as a barrier method and a Moreau Yosida regularization, and compare these methods by a program that optimizes the discrete version of the given problem.
Ma, Guodong; Zhang, Yufeng; Liu, Meixing
2017-01-01
Combining the techniques of the working set identification and generalized gradient projection, we present a new generalized gradient projection algorithm for minimax optimization problems with inequality constraints. In this paper, we propose a new optimal identification function, from which we provide a new working set. At each iteration, the improved search direction is generated by only one generalized gradient projection explicit formula, which is simple and could reduce the computational cost. Under some mild assumptions, the algorithm possesses the global and strong convergence. Finally, the numerical results show that the proposed algorithm is promising.
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%.
Bruhn, Peter; Geyer-Schulz, Andreas
2002-01-01
In this paper, we introduce genetic programming over context-free languages with linear constraints for combinatorial optimization, apply this method to several variants of the multidimensional knapsack problem, and discuss its performance relative to Michalewicz's genetic algorithm with penalty functions. With respect to Michalewicz's approach, we demonstrate that genetic programming over context-free languages with linear constraints improves convergence. A final result is that genetic programming over context-free languages with linear constraints is ideally suited to modeling complementarities between items in a knapsack problem: The more complementarities in the problem, the stronger the performance in comparison to its competitors.
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.
Wang, Huimin; Yang, Guang-Hong
2012-11-01
This paper studies the problem of state feedback controller design for a class of nonlinear systems, which are described by continuous-time affine fuzzy models. A convex piecewise affine controller design method is proposed based on a new dilated linear matrix inequality (LMI) characterization, where the system matrix is separated from Lyapunov matrix such that the controller parametrization is independent of the Lyapunov matrix. In contrast to the existing work, the derived stabilizability condition leads to less conservative LMI characterizations and much wider scope of the applicability. Furthermore, the results are extended to H(∞) state feedback synthesis. Finally, two numerical examples illustrate the superiority and effectiveness of the new results. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Huang, Qingjiu; Hase, Takamasa; Ono, Kyosuke
For studies of biped walking robots, energy-efficiency is an important issue. We have proposed an optimal-trajectory planning method based on a function approximation method, and applied it to a 2D biped walking model. With this method, we obtained the solution of minimal square integration value of the input torque. Previously in the literature, this method included only an equality state constraint. However, in this paper, we include an inequality state constraint to restrict the joint-angle range. In addition, walking experiments were performed to verify the effectiveness of this method. Results showed that stable walking of a 0.6 s period and 0.3 m/s speed was realized. Finally, we evaluated the robot's energy-efficiency using Specific Cost analysis.
Fan, Quan-Yong; Yang, Guang-Hong
2017-01-01
The state inequality constraints have been hardly considered in the literature on solving the nonlinear optimal control problem based the adaptive dynamic programming (ADP) method. In this paper, an actor-critic (AC) algorithm is developed to solve the optimal control problem with a discounted cost function for a class of state-constrained nonaffine nonlinear systems. To overcome the difficulties resulting from the inequality constraints and the nonaffine nonlinearities of the controlled systems, a novel transformation technique with redesigned slack functions and a pre-compensator method are introduced to convert the constrained optimal control problem into an unconstrained one for affine nonlinear systems. Then, based on the policy iteration (PI) algorithm, an online AC scheme is proposed to learn the nearly optimal control policy for the obtained affine nonlinear dynamics. Using the information of the nonlinear model, novel adaptive update laws are designed to guarantee the convergence of the neural network (NN) weights and the stability of the affine nonlinear dynamics without the requirement for the probing signal. Finally, the effectiveness of the proposed method is validated by simulation studies.
Stabilization of linear higher derivative gravity with constraints
Chen, Tai-jun; Lim, Eugene A. E-mail: eugene.a.lim@gmail.com
2014-05-01
We show that the instabilities of higher derivative gravity models with quadratic curvature invariant αR{sup 2}+βR{sub μν}R{sup μν} can be removed by judicious addition of constraints at the quadratic level of metric fluctuations around Minkowski/de Sitter background. With a suitable parameter choice, we find that the instabilities of helicity-0, 1, 2 modes can be removed while reducing the dimensionality of the original phase space. To retain the renormalization properties of higher derivative gravity, Lorentz symmetry in the constrained theory is explicitly broken.
Stabilization of linear higher derivative gravity with constraints
NASA Astrophysics Data System (ADS)
Chen, Tai-jun; Lim, Eugene A.
2014-05-01
We show that the instabilities of higher derivative gravity models with quadratic curvature invariant αR2+βRμνRμν can be removed by judicious addition of constraints at the quadratic level of metric fluctuations around Minkowski/de Sitter background. With a suitable parameter choice, we find that the instabilities of helicity-0, 1, 2 modes can be removed while reducing the dimensionality of the original phase space. To retain the renormalization properties of higher derivative gravity, Lorentz symmetry in the constrained theory is explicitly broken.
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…
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.
PID controller design for output PDFs of stochastic systems using linear matrix inequalities.
Guo, Lei; Wang, Hong
2005-02-01
This paper presents a pseudo proportional-integral-derivative (PID) tracking control strategy for general non-Gaussian stochastic systems based on a linear B-spline model for the output probability density functions (PDFs). The objective is to control the conditional PDFs of the system output to follow a given target function. Different from existing methods, the control structure (i.e., the PID) is imposed before the output PDF controller design. Following the linear B-spline approximation on the measured output PDFs, the concerned problem is transferred into the tracking of given weights which correspond to the desired PDF. For systems with or without model uncertainties, it is shown that the solvability can be casted into a group of matrix inequalities. Furthermore, an improved controller design procedure based on the convex optimization is proposed which can guarantee the required tracking convergence with an enhanced robustness. Simulations are given to demonstrate the efficiency of the proposed approach and encouraging results have been obtained.
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.
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.
General quantum constraints on detector noise in continuous linear measurements
NASA Astrophysics Data System (ADS)
Miao, Haixing
2017-01-01
In quantum sensing and metrology, an important class of measurement is the continuous linear measurement, in which the detector is coupled to the system of interest linearly and continuously in time. One key aspect involved is the quantum noise of the detector, arising from quantum fluctuations in the detector input and output. It determines how fast we acquire information about the system and also influences the system evolution in terms of measurement backaction. We therefore often categorize it as the so-called imprecision noise and quantum backaction noise. There is a general Heisenberg-like uncertainty relation that constrains the magnitude of and the correlation between these two types of quantum noise. The main result of this paper is to show that, when the detector becomes ideal, i.e., at the quantum limit with minimum uncertainty, not only does the uncertainty relation takes the equal sign as expected, but also there are two new equalities. This general result is illustrated by using the typical cavity QED setup with the system being either a qubit or a mechanical oscillator. Particularly, the dispersive readout of a qubit state, and the measurement of mechanical motional sideband asymmetry are considered.
Two-Link Flexible Manipulator Control Using Sliding Mode Control Based Linear Matrix Inequality
NASA Astrophysics Data System (ADS)
Zulfatman; Marzuki, Mohammad; Alif Mardiyah, Nur
2017-04-01
Two-link flexible manipulator is a manipulator robot which at least one of its arms is made of lightweight material and not rigid. Flexible robot manipulator has some advantages over the rigid robot manipulator, such as lighter, requires less power and costs, and to result greater payload. However, suitable control algorithm to maintain the two-link flexible robot manipulator in accurate positioning is very challenging. In this study, sliding mode control (SMC) was employed as robust control algorithm due to its insensitivity on the system parameter variations and the presence of disturbances when the system states are sliding on a sliding surface. SMC algorithm was combined with linear matrix inequality (LMI), which aims to reduce the effects of chattering coming from the oscillation of the state during sliding on the sliding surface. Stability of the control algorithm is guaranteed by Lyapunov function candidate. Based on simulation works, SMC based LMI resulted in better performance improvements despite the disturbances with significant chattering reduction. This was evident from the decline of the sum of squared tracking error (SSTE) and the sum of squared of control input (SSCI) indexes respectively 25.4% and 19.4%.
Superlinear convergence of an interior-point method for monotone variational inequalities
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.
NASA Astrophysics Data System (ADS)
Winicour, Jeffrey
2017-08-01
An algebraic-hyperbolic method for solving the Hamiltonian and momentum constraints has recently been shown to be well posed for general nonlinear perturbations of the initial data for a Schwarzschild black hole. This is a new approach to solving the constraints of Einstein’s equations which does not involve elliptic equations and has potential importance for the construction of binary black hole data. In order to shed light on the underpinnings of this approach, we consider its application to obtain solutions of the constraints for linearized perturbations of Minkowski space. In that case, we find the surprising result that there are no suitable Cauchy hypersurfaces in Minkowski space for which the linearized algebraic-hyperbolic constraint problem is well posed.
A dual method for optimal control problems with initial and final boundary constraints.
NASA Technical Reports Server (NTRS)
Pironneau, O.; Polak, E.
1973-01-01
This paper presents two new algorithms belonging to the family of dual methods of centers. The first can be used for solving fixed time optimal control problems with inequality constraints on the initial and terminal states. The second one can be used for solving fixed time optimal control problems with inequality constraints on the initial and terminal states and with affine instantaneous inequality constraints on the control. Convergence is established for both algorithms. Qualitative reasoning indicates that the rate of convergence is linear.
A dual method for optimal control problems with initial and final boundary constraints.
NASA Technical Reports Server (NTRS)
Pironneau, O.; Polak, E.
1973-01-01
This paper presents two new algorithms belonging to the family of dual methods of centers. The first can be used for solving fixed time optimal control problems with inequality constraints on the initial and terminal states. The second one can be used for solving fixed time optimal control problems with inequality constraints on the initial and terminal states and with affine instantaneous inequality constraints on the control. Convergence is established for both algorithms. Qualitative reasoning indicates that the rate of convergence is linear.
Quantized Feedback Stabilization of Linear Discrete-Time Systems with Constraints
NASA Astrophysics Data System (ADS)
Zanma, Tadanao; Yamamoto, Yusuke; Ishida, Muneaki
This paper addresses quantization of control systems. The state of the system is quantized via a quantizer. In addition, constraints on input and/or state are considered explicitly. For a linear system with no constraint, some quantized feedback control methods have been proposed. In this paper, a control methodology for the constrained system is proposed. Specifically, an idea of a positively invariant set is introduced so that the performance is improved while the constraints are satisfied. The effectiveness of the proposed method is verified through both simulation and experiment.
On Implicit Active Constraints in Linear Semi-Infinite Programs with Unbounded Coefficients
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.
Time optimal controls of the linear Fitzhugh–Nagumo equation with pointwise control constraints
Kunisch, Karl; Wang, Lijuan
2012-01-01
Time optimal control governed by the internally controlled linear Fitzhugh–Nagumo equation with pointwise control constraint is considered. Making use of Ekeland’s variational principle, we obtain Pontryagin’s maximum principle for a time optimal control problem. Using the maximum principle, the bang–bang property of the optimal controls is established under appropriate assumptions. PMID:23576818
Time optimal controls of the linear Fitzhugh-Nagumo equation with pointwise control constraints.
Kunisch, Karl; Wang, Lijuan
2012-11-01
Time optimal control governed by the internally controlled linear Fitzhugh-Nagumo equation with pointwise control constraint is considered. Making use of Ekeland's variational principle, we obtain Pontryagin's maximum principle for a time optimal control problem. Using the maximum principle, the bang-bang property of the optimal controls is established under appropriate assumptions.
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.
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
Klamt, Steffen; Gerstl, Matthias P.; Jungreuthmayer, Christian; Mahadevan, Radhakrishnan; Müller, Stefan
2017-01-01
Elementary flux modes (EFMs) emerged as a formal concept to describe metabolic pathways and have become an established tool for constraint-based modeling and metabolic network analysis. EFMs are characteristic (support-minimal) vectors of the flux cone that contains all feasible steady-state flux vectors of a given metabolic network. EFMs account for (homogeneous) linear constraints arising from reaction irreversibilities and the assumption of steady state; however, other (inhomogeneous) linear constraints, such as minimal and maximal reaction rates frequently used by other constraint-based techniques (such as flux balance analysis [FBA]), cannot be directly integrated. These additional constraints further restrict the space of feasible flux vectors and turn the flux cone into a general flux polyhedron in which the concept of EFMs is not directly applicable anymore. For this reason, there has been a conceptual gap between EFM-based (pathway) analysis methods and linear optimization (FBA) techniques, as they operate on different geometric objects. One approach to overcome these limitations was proposed ten years ago and is based on the concept of elementary flux vectors (EFVs). Only recently has the community started to recognize the potential of EFVs for metabolic network analysis. In fact, EFVs exactly represent the conceptual development required to generalize the idea of EFMs from flux cones to flux polyhedra. This work aims to present a concise theoretical and practical introduction to EFVs that is accessible to a broad audience. We highlight the close relationship between EFMs and EFVs and demonstrate that almost all applications of EFMs (in flux cones) are possible for EFVs (in flux polyhedra) as well. In fact, certain properties can only be studied with EFVs. Thus, we conclude that EFVs provide a powerful and unifying framework for constraint-based modeling of metabolic networks. PMID:28406903
Klamt, Steffen; Regensburger, Georg; Gerstl, Matthias P; Jungreuthmayer, Christian; Schuster, Stefan; Mahadevan, Radhakrishnan; Zanghellini, Jürgen; Müller, Stefan
2017-04-01
Elementary flux modes (EFMs) emerged as a formal concept to describe metabolic pathways and have become an established tool for constraint-based modeling and metabolic network analysis. EFMs are characteristic (support-minimal) vectors of the flux cone that contains all feasible steady-state flux vectors of a given metabolic network. EFMs account for (homogeneous) linear constraints arising from reaction irreversibilities and the assumption of steady state; however, other (inhomogeneous) linear constraints, such as minimal and maximal reaction rates frequently used by other constraint-based techniques (such as flux balance analysis [FBA]), cannot be directly integrated. These additional constraints further restrict the space of feasible flux vectors and turn the flux cone into a general flux polyhedron in which the concept of EFMs is not directly applicable anymore. For this reason, there has been a conceptual gap between EFM-based (pathway) analysis methods and linear optimization (FBA) techniques, as they operate on different geometric objects. One approach to overcome these limitations was proposed ten years ago and is based on the concept of elementary flux vectors (EFVs). Only recently has the community started to recognize the potential of EFVs for metabolic network analysis. In fact, EFVs exactly represent the conceptual development required to generalize the idea of EFMs from flux cones to flux polyhedra. This work aims to present a concise theoretical and practical introduction to EFVs that is accessible to a broad audience. We highlight the close relationship between EFMs and EFVs and demonstrate that almost all applications of EFMs (in flux cones) are possible for EFVs (in flux polyhedra) as well. In fact, certain properties can only be studied with EFVs. Thus, we conclude that EFVs provide a powerful and unifying framework for constraint-based modeling of metabolic networks.
Iterated non-linear model predictive control based on tubes and contractive constraints.
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.
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,…
A quadratic-tensor model algorithm for nonlinear least-squares problems with linear constraints
NASA Technical Reports Server (NTRS)
Hanson, R. J.; Krogh, Fred T.
1992-01-01
A new algorithm for solving nonlinear least-squares and nonlinear equation problems is proposed which is based on approximating the nonlinear functions using the quadratic-tensor model by Schnabel and Frank. The algorithm uses a trust region defined by a box containing the current values of the unknowns. The algorithm is found to be effective for problems with linear constraints and dense Jacobian matrices.
A quadratic-tensor model algorithm for nonlinear least-squares problems with linear constraints
NASA Technical Reports Server (NTRS)
Hanson, R. J.; Krogh, Fred T.
1992-01-01
A new algorithm for solving nonlinear least-squares and nonlinear equation problems is proposed which is based on approximating the nonlinear functions using the quadratic-tensor model by Schnabel and Frank. The algorithm uses a trust region defined by a box containing the current values of the unknowns. The algorithm is found to be effective for problems with linear constraints and dense Jacobian matrices.
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.
Improved linear kinetic Sunyaev-Zel'dovich effect constraints on the observed Local Void
NASA Astrophysics Data System (ADS)
Hoscheit, Benjamin L.; Barger, Amy J.
2017-01-01
A class of large, gigaparsec (Gpc)-scale local void models has been ruled out by linear kinetic Sunyaev-Zel'dovich (kSZ) effect constraints from the South Pole Telescope and the Atacama Cosmology Telescope. However, there is substantial and growing observational evidence from the normalized luminosity density in the near-infrared that the local universe may be under-dense on scales of several hundred Megaparsecs. Theoretically, a small void model would relieve tension in observational challenges to the standard Friedmann-Lemaître-Robertson-Walker (FLRW) cosmological model. Thus, we decided to test whether a small void described by a parameterization of the observational data could be ruled out by the latest linear kSZ constraints. Instead, we find that the previous linear kSZ constraints as well as new ones from the South Pole Telescope are fully compatible with the existence of a small void of the size suggested by the luminosity density observations. The presence of such a void could have cosmologically significant implications.
Elzoghby, Mostafa; Li, Fu; Arafa, Ibrahim I; Arif, Usman
2017-04-18
Information fusion from multiple sensors ensures the accuracy and robustness of a navigation system, especially in the absence of global positioning system (GPS) data which gets degraded in many cases. A way to deal with multi-mode estimation for a small fixed wing unmanned aerial vehicle (UAV) localization framework is proposed, which depends on utilizing a Luenberger observer-based linear matrix inequality (LMI) approach. The proposed estimation technique relies on the interaction between multiple measurement modes and a continuous observer. The state estimation is performed in a switching environment between multiple active sensors to exploit the available information as much as possible, especially in GPS-denied environments. Luenberger observer-based projection is implemented as a continuous observer to optimize the estimation performance. The observer gain might be chosen by solving a Lyapunov equation by means of a LMI algorithm. Convergence is achieved by utilizing the linear matrix inequality (LMI), based on Lyapunov stability which keeps the dynamic estimation error bounded by selecting the observer gain matrix (L). Simulation results are presented for a small UAV fixed wing localization problem. The results obtained using the proposed approach are compared with a single mode Extended Kalman Filter (EKF). Simulation results are presented to demonstrate the viability of the proposed strategy.
Elzoghby, Mostafa; Li, Fu; Arafa, Ibrahim. I.; Arif, Usman
2017-01-01
Information fusion from multiple sensors ensures the accuracy and robustness of a navigation system, especially in the absence of global positioning system (GPS) data which gets degraded in many cases. A way to deal with multi-mode estimation for a small fixed wing unmanned aerial vehicle (UAV) localization framework is proposed, which depends on utilizing a Luenberger observer-based linear matrix inequality (LMI) approach. The proposed estimation technique relies on the interaction between multiple measurement modes and a continuous observer. The state estimation is performed in a switching environment between multiple active sensors to exploit the available information as much as possible, especially in GPS-denied environments. Luenberger observer-based projection is implemented as a continuous observer to optimize the estimation performance. The observer gain might be chosen by solving a Lyapunov equation by means of a LMI algorithm. Convergence is achieved by utilizing the linear matrix inequality (LMI), based on Lyapunov stability which keeps the dynamic estimation error bounded by selecting the observer gain matrix (L). Simulation results are presented for a small UAV fixed wing localization problem. The results obtained using the proposed approach are compared with a single mode Extended Kalman Filter (EKF). Simulation results are presented to demonstrate the viability of the proposed strategy. PMID:28420214
Non-linear modal analysis of structural components subjected to unilateral constraints
NASA Astrophysics Data System (ADS)
Attar, M.; Karrech, A.; Regenauer-Lieb, K.
2017-02-01
In this paper, we present a detailed numerical study of the non-linear dynamics in structural components under unilateral contact constraints. Here, the unilateral term characterises the constitutive law of the restoring force in the constraints as they only sustain elastic reactions in one direction, either compressive or tensile. Thus, the non-differentiability of the contact law at the discontinuity point is the only source of non-linearity. In our approach, the discrete lattice method (DLM) is used to treat the continuous system as a piecewise linear model. Thus, the trajectory of each node in the discrete model would be a sequence of smooth solutions with the switching times between them. The application of the one-step integration scheme allows us to detect the occurrence of contact (i.e. the instants that the lattice nodes cross the discontinuity boundary) and consequently update the active constraints. We also consider embedding the bisection algorithm into the time integration procedure to localise the instants at which the nodes cross the boundary and minimise the accumulative error. Subsequently, the resulting unconditionally stable integration scheme is utilised as the modelling tool in combination with the shooting technique to perform a novel non-smooth modal analysis. In analogy with the smooth non-linear systems, the evolution of non-smooth periodic motions is presented in the frequency-stiffness plots. We apply our method to obtain non-linear normal modes (NNMs) for a number of representative problems, including a bar-obstacle system, a beam-substrate system and a granular chain with tensionless interactions. These numerical examples demonstrate the efficiency of the solution procedure to trace the family of energy-independent non-linear modes across the range of contact stiffnesses. Moreover, the stability analysis of the modes on the plot backbone reveal that they may become unstable due to the interaction with the higher modes or bifurcation of
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.
Liang, X B; Si, J
2001-01-01
This paper investigates the existence, uniqueness, and global exponential stability (GES) of the equilibrium point for a large class of neural networks with globally Lipschitz continuous activations including the widely used sigmoidal activations and the piecewise linear activations. The provided sufficient condition for GES is mild and some conditions easily examined in practice are also presented. The GES of neural networks in the case of locally Lipschitz continuous activations is also obtained under an appropriate condition. The analysis results given in the paper extend substantially the existing relevant stability results in the literature, and therefore expand significantly the application range of neural networks in solving optimization problems. As a demonstration, we apply the obtained analysis results to the design of a recurrent neural network (RNN) for solving the linear variational inequality problem (VIP) defined on any nonempty and closed box set, which includes the box constrained quadratic programming and the linear complementarity problem as the special cases. It can be inferred that the linear VIP has a unique solution for the class of Lyapunov diagonally stable matrices, and that the synthesized RNN is globally exponentially convergent to the unique solution. Some illustrative simulation examples are also given.
Chaves, Rafael
2016-01-08
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.
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.
Huang, Hao; Zhang, Guifu; Zhao, Kun; ...
2016-10-20
A hybrid method of combining linear programming (LP) and physical constraints is developed to estimate specific differential phase (KDP) and to improve rain estimation. Moreover, the hybrid KDP estimator and the existing estimators of LP, least squares fitting, and a self-consistent relation of polarimetric radar variables are evaluated and compared using simulated data. Our simulation results indicate the new estimator's superiority, particularly in regions where backscattering phase (δhv) dominates. Further, a quantitative comparison between auto-weather-station rain-gauge observations and KDP-based radar rain estimates for a Meiyu event also demonstrate the superiority of the hybrid KDP estimator over existing methods.
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
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.
Computing minimal nutrient sets from metabolic networks via linear constraint solving
2013-01-01
Background As more complete genome sequences become available, bioinformatics challenges arise in how to exploit genome sequences to make phenotypic predictions. One type of phenotypic prediction is to determine sets of compounds that will support the growth of a bacterium from the metabolic network inferred from the genome sequence of that organism. Results We present a method for computationally determining alternative growth media for an organism based on its metabolic network and transporter complement. Our method predicted 787 alternative anaerobic minimal nutrient sets for Escherichia coli K–12 MG1655 from the EcoCyc database. The program automatically partitioned the nutrients within these sets into 21 equivalence classes, most of which correspond to compounds serving as sources of carbon, nitrogen, phosphorous, and sulfur, or combinations of these essential elements. The nutrient sets were predicted with 72.5% accuracy as evaluated by comparison with 91 growth experiments. Novel aspects of our approach include (a) exhaustive consideration of all combinations of nutrients rather than assuming that all element sources can substitute for one another(an assumption that can be invalid in general) (b) leveraging the notion of a machinery-duplicating constraint, namely, that all intermediate metabolites used in active reactions must be produced in increasing concentrations to prevent successive dilution from cell division, (c) the use of Satisfiability Modulo Theory solvers rather than Linear Programming solvers, because our approach cannot be formulated as linear programming, (d) the use of Binary Decision Diagrams to produce an efficient implementation. Conclusions Our method for generating minimal nutrient sets from the metabolic network and transporters of an organism combines linear constraint solving with binary decision diagrams to efficiently produce solution sets to provided growth problems. PMID:23537498
Huang, Hao; Zhang, Guifu; Zhao, Kun; Giangrande, Scott E.
2016-10-20
A hybrid method of combining linear programming (LP) and physical constraints is developed to estimate specific differential phase (K_{DP}) and to improve rain estimation. Moreover, the hybrid K_{DP} estimator and the existing estimators of LP, least squares fitting, and a self-consistent relation of polarimetric radar variables are evaluated and compared using simulated data. Our simulation results indicate the new estimator's superiority, particularly in regions where backscattering phase (δ_{hv}) dominates. Further, a quantitative comparison between auto-weather-station rain-gauge observations and K_{DP}-based radar rain estimates for a Meiyu event also demonstrate the superiority of the hybrid K_{DP} estimator over existing methods.
Constraints to solve parallelogram grid problems in 2D non separable linear canonical transform
NASA Astrophysics Data System (ADS)
Zhao, Liang; Healy, John J.; Muniraj, Inbarasan; Cui, Xiao-Guang; Malallah, Ra'ed; Ryle, James P.; Sheridan, John T.
2017-05-01
The 2D non-separable linear canonical transform (2D-NS-LCT) can model a range of various paraxial optical systems. Digital algorithms to evaluate the 2D-NS-LCTs are important in modeling the light field propagations and also of interest in many digital signal processing applications. In [Zhao 14] we have reported that a given 2D input image with rectangular shape/boundary, in general, results in a parallelogram output sampling grid (generally in an affine coordinates rather than in a Cartesian coordinates) thus limiting the further calculations, e.g. inverse transform. One possible solution is to use the interpolation techniques; however, it reduces the speed and accuracy of the numerical approximations. To alleviate this problem, in this paper, some constraints are derived under which the output samples are located in the Cartesian coordinates. Therefore, no interpolation operation is required and thus the calculation error can be significantly eliminated.
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
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.
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.
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.
Nielsen, François
2017-02-01
Kelley and Evans (2017) found that income inequality (measured at the societal level) did not affect individual well-being in advanced societies but increased individual well-being in developing societies. This paper discusses how this empirical patterning of the inequality-well-being relationship may arise from mechanisms related to the relationship of inequality with economic development (at the macro-sociological level) and to the evolution of emotional reactions to inequality (at the individual-psychological level).
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.
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.
Zaghian, Maryam; Lim, Gino; Liu, Wei; Mohan, Radhe
2014-01-01
Prescriptions for radiation therapy are given in terms of dose-volume constraints (DVCs). Solving the fluence map optimization (FMO) problem while satisfying DVCs often requires a tedious trial-and-error for selecting appropriate dose control parameters on various organs. In this paper, we propose an iterative approach to satisfy DVCs using a multi-objective linear programming (LP) model for solving beamlet intensities. This algorithm, starting from arbitrary initial parameter values, gradually updates the values through an iterative solution process toward optimal solution. This method finds appropriate parameter values through the trade-off between OAR sparing and target coverage to improve the solution. We compared the plan quality and the satisfaction of the DVCs by the proposed algorithm with two nonlinear approaches: a nonlinear FMO model solved by using the L-BFGS algorithm and another approach solved by a commercial treatment planning system (Eclipse 8.9). We retrospectively selected from our institutional database five patients with lung cancer and one patient with prostate cancer for this study. Numerical results show that our approach successfully improved target coverage to meet the DVCs, while trying to keep corresponding OAR DVCs satisfied. The LBFGS algorithm for solving the nonlinear FMO model successfully satisfied the DVCs in three out of five test cases. However, there is no recourse in the nonlinear FMO model for correcting unsatisfied DVCs other than manually changing some parameter values through trial and error to derive a solution that more closely meets the DVC requirements. The LP-based heuristic algorithm outperformed the current treatment planning system in terms of DVC satisfaction. A major strength of the LP-based heuristic approach is that it is not sensitive to the starting condition. PMID:25506501
Zaghian, Maryam; Lim, Gino; Liu, Wei; Mohan, Radhe
2014-02-01
Prescriptions for radiation therapy are given in terms of dose-volume constraints (DVCs). Solving the fluence map optimization (FMO) problem while satisfying DVCs often requires a tedious trial-and-error for selecting appropriate dose control parameters on various organs. In this paper, we propose an iterative approach to satisfy DVCs using a multi-objective linear programming (LP) model for solving beamlet intensities. This algorithm, starting from arbitrary initial parameter values, gradually updates the values through an iterative solution process toward optimal solution. This method finds appropriate parameter values through the trade-off between OAR sparing and target coverage to improve the solution. We compared the plan quality and the satisfaction of the DVCs by the proposed algorithm with two nonlinear approaches: a nonlinear FMO model solved by using the L-BFGS algorithm and another approach solved by a commercial treatment planning system (Eclipse 8.9). We retrospectively selected from our institutional database five patients with lung cancer and one patient with prostate cancer for this study. Numerical results show that our approach successfully improved target coverage to meet the DVCs, while trying to keep corresponding OAR DVCs satisfied. The LBFGS algorithm for solving the nonlinear FMO model successfully satisfied the DVCs in three out of five test cases. However, there is no recourse in the nonlinear FMO model for correcting unsatisfied DVCs other than manually changing some parameter values through trial and error to derive a solution that more closely meets the DVC requirements. The LP-based heuristic algorithm outperformed the current treatment planning system in terms of DVC satisfaction. A major strength of the LP-based heuristic approach is that it is not sensitive to the starting condition.
Bowles, Samuel; Loury, Glenn C.; Sethi, Rajiv
2014-01-01
We explore the combined effect of segregation in social networks, peer effects, and the relative size of a historically disadvantaged group on the incentives to invest in market-rewarded skills and the dynamics of inequality between social groups. We identify conditions under which group inequality will persist in the absence of differences in ability, credit constraints, or labor market discrimination. Under these conditions, group inequality may be amplified even if initial group differences are negligible. Increases in social integration may destabilize an unequal state and make group equality possible, but the distributional and human capital effects of this depend on the demographic composition of the population. When the size of the initially disadvantaged group is sufficiently small, integration can lower the long-run costs of human capital investment in both groups and result in an increase the aggregate skill share. In contrast, when the initially disadvantaged group is large, integration can induce a fall in the aggregate skill share as the costs of human capital investment rise in both groups. We consider applications to concrete cases and policy implications. PMID:25554727
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.
The report discusses a two person max -min problem in which the maximizing player moves first and the minimizing player has perfect information of the...The joint constraints as well as the objective function are assumed to be linear. For this problem it is shown that the familiar inequality min max ...or = max min is reversed due to the influence of the joint constraints. The problem is characterized as a nonconvex program and a method of
Accommodation of practical constraints by a linear programming jet select. [for Space Shuttle
NASA Technical Reports Server (NTRS)
Bergmann, E.; Weiler, P.
1983-01-01
An experimental spacecraft control system will be incorporated into the Space Shuttle flight software and exercised during a forthcoming mission to evaluate its performance and handling qualities. The control system incorporates a 'phase space' control law to generate rate change requests and a linear programming jet select to compute jet firings. Posed as a linear programming problem, jet selection must represent the rate change request as a linear combination of jet acceleration vectors where the coefficients are the jet firing times, while minimizing the fuel expended in satisfying that request. This problem is solved in real time using a revised Simplex algorithm. In order to implement the jet selection algorithm in the Shuttle flight control computer, it was modified to accommodate certain practical features of the Shuttle such as limited computer throughput, lengthy firing times, and a large number of control jets. To the authors' knowledge, this is the first such application of linear programming. It was made possible by careful consideration of the jet selection problem in terms of the properties of linear programming and the Simplex algorithm. These modifications to the jet select algorithm may by useful for the design of reaction controlled spacecraft.
Linear spectropolarimetry of AP stars: a new degree of constraint on magnetic structure
NASA Astrophysics Data System (ADS)
Wade, G. A.; Donati, J.-F.; Mathys, G.; Piskunov, N.
1998-04-01
We present preliminary results from a programme aimed at acquiring linear spectropolarimetry of magnetic A and B stars. Linear polarization in the spectral lines of these objects is due to the Zeeman effect, and should provide detailed new information regarding the structure of their strong magnetic fields. To illustrate the impact of these new data, we compare observed circular and linear polarization line profiles of 53 Cam with the profiles predicted by the magnetic model by Landstreet. Linear polarization in the spectral lines of all stars studied is extremely weak; in most cases, below the threshold of detectability even for very high SNRs. In order to overcome this problem, we employ the Least-Squares Deconvolution (LSD) multi-line analysis technique in order to extract low-noise mean line profiles and polarization signatures from our echelle spectra. Tests show that these mean signatures can be modelled as real spectral lines, and have the potential to lead to high-resolution maps of the magnetic and chemical abundance surface distributions.
A sequential linear optimization approach for controller design
NASA Technical Reports Server (NTRS)
Horta, L. G.; Juang, J.-N.; Junkins, J. L.
1985-01-01
A linear optimization approach with a simple real arithmetic algorithm is presented for reliable controller design and vibration suppression of flexible structures. Using first order sensitivity of the system eigenvalues with respect to the design parameters in conjunction with a continuation procedure, the method converts a nonlinear optimization problem into a maximization problem with linear inequality constraints. The method of linear programming is then applied to solve the converted linear optimization problem. The general efficiency of the linear programming approach allows the method to handle structural optimization problems with a large number of inequality constraints on the design vector. The method is demonstrated using a truss beam finite element model for the optimal sizing and placement of active/passive-structural members for damping augmentation. Results using both the sequential linear optimization approach and nonlinear optimization are presented and compared. The insensitivity to initial conditions of the linear optimization approach is also demonstrated.
Schmerling, Edward; Janson, Lucas; Pavone, Marco
2015-01-01
In this paper we provide a thorough, rigorous theoretical framework to assess optimality guarantees of sampling-based algorithms for drift control systems: systems that, loosely speaking, can not stop instantaneously due to momentum. We exploit this framework to design and analyze a sampling-based algorithm (the Differential Fast Marching Tree algorithm) that is asymptotically optimal, that is, it is guaranteed to converge, as the number of samples increases, to an optimal solution. In addition, our approach allows us to provide concrete bounds on the rate of this convergence. The focus of this paper is on mixed time/control energy cost functions and on linear affine dynamical systems, which encompass a range of models of interest to applications (e.g., double-integrators) and represent a necessary step to design, via successive linearization, sampling-based and provably-correct algorithms for non-linear drift control systems. Our analysis relies on an original perturbation analysis for two-point boundary value problems, which could be of independent interest. PMID:26997749
NASA Astrophysics Data System (ADS)
Eliazar, Iddo
2017-03-01
Inequality indices are widely applied in economics and in the social sciences as quantitative measures of the socioeconomic inequality of human societies. The application of inequality indices extends to size-distributions at large, where these indices can be used as general gauges of statistical heterogeneity. Moreover, as inequality indices are plentiful, arrays of such indices facilitate high-detail quantification of statistical heterogeneity. In this paper we elevate from arrays of inequality indices to inequality spectra: continuums of inequality indices that are parameterized by a single control parameter. We present a general methodology of constructing Lorenz-based inequality spectra, apply the general methodology to establish four sets of inequality spectra, investigate the properties of these sets, and show how these sets generalize known inequality gauges such as: the Gini index, the extended Gini index, the Rényi index, and hill curves.
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.
A frequency based constraint for a multi-frequency linear sampling method
NASA Astrophysics Data System (ADS)
Alqadah, H. F.; Valdivia, N.
2013-09-01
The linear sampling method (LSM) has become a well established non-iterative technique for a variety of inverse scattering problems. The method offers a number of advantages over competing inverse scattering methods, mainly it is based on solving a linear problem while being able to account for multi-path effects. Unfortunately under the current framework the method is only effective when using a large number of multi-static data, and therefore may be impractical for many imaging applications. While primarily developed under a single frequency framework, recently the extension of the method to multi-banded data sets has been considered. It is known in general that the availability of multi-frequency data should compensate for reduced spatial diversity, but it is not clear how this can be accomplished for the LSM. In this work we take a step in this direction by considering a frequency based partial variation approach. We first establish that on bands absent of any corresponding Dirichlet eigenvalues the Herglotz density exhibits bounded variation. We then consider a regularization method incorporating this prior knowledge. The proposed approach exhibited a good estimate of the unknown Dirichlet eigenvalues of the obstacle in question when using reduced data. This observation also correlated with higher quality 3D reconstructions.
Sobolev and Hardy-Littlewood-Sobolev inequalities
NASA Astrophysics Data System (ADS)
Dolbeault, Jean; Jankowiak, Gaspard
2014-09-01
This paper is devoted to improvements of Sobolev and Onofri inequalities. The additional terms involve the dual counterparts, i.e. Hardy-Littlewood-Sobolev type inequalities. The Onofri inequality is achieved as a limit case of Sobolev type inequalities. Then we focus our attention on the constants in our improved Sobolev inequalities, that can be estimated by completion of the square methods. Our estimates rely on nonlinear flows and spectral problems based on a linearization around optimal Aubin-Talenti functions.
7D bosonic higher spin gauge theory: symmetry algebra and linearized constraints
NASA Astrophysics Data System (ADS)
Sezgin, E.; Sundell, P.
2002-07-01
We construct the minimal bosonic higher spin extension of the 7D AdS algebra SO(6,2), which we call hs(8 ∗) . The generators, which have spin s=1,3,5,… , are realized as monomials in Grassmann even spinor oscillators. Irreducibility, in the form of tracelessness, is achieved by modding out an infinite-dimensional ideal containing the traces. In this a key role is played by the tree bilinear traces which form an SU(2) K algebra. We show that gauging of hs(8 ∗) yields a spectrum of physical fields with spin s=0,2,4,… which make up a UIR of hs(8 ∗) isomorphic to the symmetric tensor product of two 6D scalar doubletons. The scalar doubleton is the unique SU(2) K invariant 6D doubleton. The spin s⩾2 sector comes from an hs(8 ∗) -valued one-form which also contains the auxiliary gauge fields required for writing the curvature constraints in covariant form. The physical spin s=0 field arises in a separate zero-form in a 'quasi-adjoint' representation of hs(8 ∗) . This zero-form also contains the spin s⩾2 Weyl tensors, i.e., the curvatures which are non-vanishing on-shell. We suggest that the hs(8 ∗) gauge theory describes the minimal bosonic, massless truncation of M-theory on AdS7× S4 in an unbroken phase where the holographic dual is given by N free (2,0) tensor multiplets for large N.
Yu, Huapeng; Zhu, Hai; Gao, Dayuan; Yu, Meng; Wu, Wenqi
2015-02-13
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.
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
NASA Technical Reports Server (NTRS)
Saleeb, A. F.; Chang, T. Y.; Yingyeunyong, S.
1988-01-01
A simple and effective linear C(0)-tiangular element for plates and shells is developed on the basis of the Hellinger-Reissner mixed variational principle with independently assumed stress and displacement fields. Two main features are emphasized in this development concerning the assumed transverse shear stress field. First, this assumption results in edge-type penalty constraints in the thin plate/shell regimes. Second, the element is used in the form of a four-triangle, cross-diagonal macroelement mesh. As a result, the element is shown to be free from shear locking in thin plate/shell applications, and it satisfies all the appropriate patch tests required for Kirchhoff plate models. In addition, the element exhibits good overall convergence properties in a variety of test problems for plates and shells. Finally, from the computational standpoint, the element is very efficient since all stiffness component matrices are derived in explicit forms.
Serang, Oliver
2012-01-01
Linear programming (LP) problems are commonly used in analysis and resource allocation, frequently surfacing as approximations to more difficult problems. Existing approaches to LP have been dominated by a small group of methods, and randomized algorithms have not enjoyed popularity in practice. This paper introduces a novel randomized method of solving LP problems by moving along the facets and within the interior of the polytope along rays randomly sampled from the polyhedral cones defined by the bounding constraints. This conic sampling method is then applied to randomly sampled LPs, and its runtime performance is shown to compare favorably to the simplex and primal affine-scaling algorithms, especially on polytopes with certain characteristics. The conic sampling method is then adapted and applied to solve a certain quadratic program, which compute a projection onto a polytope; the proposed method is shown to outperform the proprietary software Mathematica on large, sparse QP problems constructed from mass spectometry-based proteomics. PMID:22952741
Serang, Oliver
2012-01-01
Linear programming (LP) problems are commonly used in analysis and resource allocation, frequently surfacing as approximations to more difficult problems. Existing approaches to LP have been dominated by a small group of methods, and randomized algorithms have not enjoyed popularity in practice. This paper introduces a novel randomized method of solving LP problems by moving along the facets and within the interior of the polytope along rays randomly sampled from the polyhedral cones defined by the bounding constraints. This conic sampling method is then applied to randomly sampled LPs, and its runtime performance is shown to compare favorably to the simplex and primal affine-scaling algorithms, especially on polytopes with certain characteristics. The conic sampling method is then adapted and applied to solve a certain quadratic program, which compute a projection onto a polytope; the proposed method is shown to outperform the proprietary software Mathematica on large, sparse QP problems constructed from mass spectometry-based proteomics.
Working memory constraints on linear reasoning with spatial and temporal contents.
Vandierendonck, A; De Vooght, G
1997-11-01
The present article reports two experiments testing the use of working memory components during reasoning with temporal and spatial relations in four-term series problems. In the first experiment four groups of subjects performed reasoning tasks with temporal and with spatial contents either without (control) or with a secondary task (articulatory suppression, visuo-spatial suppression or central executive suppression). The second experiment tested the secondary task effects in a within-subjects design either on problems with a spatial content or on problems with a temporal content, and within each content domain either under conditions of self-paced or of fixed presentation of the premises. Both experiments found effects of all three secondary tasks on reasoning accuracy. This supports the hypothesis that the subjects construct spatial representations of the premise information with the support of visuo-spatial resources of working memory. The second experiment also showed that during premise intake, only visuo-spatial and central executive secondary tasks had an effect. The implications of the data for the working memory requirements of reasoning and for theories of linear reasoning are discussed.
Constraints on lepton asymmetry from nucleosynthesis in a linearly coasting cosmology
NASA Astrophysics Data System (ADS)
Singh, Parminder; Lohiya, Daksh
2015-05-01
We study the effect of neutrino degeneracy on primordial nucleosynthesis in a universe in which the cosmological scale factor evolves linearly with time. The degeneracy parameter of electron type neutrinos (ξe) determines the n/p (neutron to proton) ratio, which in turn determines the abundance of 4He in a manner quite distinct from the Standard Scenario. The observed abundances of 4He, YP = 0.254 ± 0.003, and the minimum metallicity that is essential for fragmentation and cooling processes in star forming prestellar gas clouds (Z = Zcr = 10-6Zsolar), constrain the baryon to photon ratio, ηB = (3.927±0.292)10-9, corresponding to a baryonic matter density, ΩB = 0.263 ± 0.026 and ξe = -2.165 ± 0.171. This closes the dynamic mass estimates of matter in the universe, obtained from large scale velocity dispersion in galaxy clusters, by baryons alone. Useful byproducts are the threshold X(CNO) abundances required to trigger the CNO cycle in the observed low metallicity stars in the universe.
Constraints on lepton asymmetry from nucleosynthesis in a linearly coasting cosmology
Singh, Parminder; Lohiya, Daksh E-mail: dl116@cam.ac.uk
2015-05-01
We study the effect of neutrino degeneracy on primordial nucleosynthesis in a universe in which the cosmological scale factor evolves linearly with time. The degeneracy parameter of electron type neutrinos (ξ{sub e}) determines the n/p (neutron to proton) ratio, which in turn determines the abundance of {sup 4}He in a manner quite distinct from the Standard Scenario. The observed abundances of {sup 4}He, Y{sub P} = 0.254 ± 0.003, and the minimum metallicity that is essential for fragmentation and cooling processes in star forming prestellar gas clouds (Z = Z{sub cr} = 10{sup −6}Z{sub ⊙}), constrain the baryon to photon ratio, η{sub B} = (3.927±0.292)10{sup −9}, corresponding to a baryonic matter density, Ω{sub B} = 0.263 ± 0.026 and ξ{sub e} = -2.165 ± 0.171. This closes the dynamic mass estimates of matter in the universe, obtained from large scale velocity dispersion in galaxy clusters, by baryons alone. Useful byproducts are the threshold X(CNO) abundances required to trigger the CNO cycle in the observed low metallicity stars in the universe.
A Novel Neural Network for Generally Constrained Variational Inequalities.
Gao, Xingbao; Liao, Li-Zhi
2016-06-13
This paper presents a novel neural network for solving generally constrained variational inequality problems by constructing a system of double projection equations. By defining proper convex energy functions, the proposed neural network is proved to be stable in the sense of Lyapunov and converges to an exact solution of the original problem for any starting point under the weaker cocoercivity condition or the monotonicity condition of the gradient mapping on the linear equation set. Furthermore, two sufficient conditions are provided to ensure the stability of the proposed neural network for a special case. The proposed model overcomes some shortcomings of existing continuous-time neural networks for constrained variational inequality, and its stability only requires some monotonicity conditions of the underlying mapping and the concavity of nonlinear inequality constraints on the equation set. The validity and transient behavior of the proposed neural network are demonstrated by some simulation results.
Alesina, Alberto; Michalopoulos, Stelios; Papaioannou, Elias
2015-01-01
This study explores the consequences and origins of between-ethnicity economic inequality across countries. First, combining satellite images of nighttime luminosity with the historical homelands of ethnolinguistic groups we construct measures of ethnic inequality for a large sample of countries. We also compile proxies of overall spatial inequality and regional inequality across administrative units. Second, we uncover a strong negative association between ethnic inequality and contemporary comparative development; the correlation is also present when we condition on regional inequality, which is itself related to under-development. Third, we investigate the roots of ethnic inequality and establish that differences in geographic endowments across ethnic homelands explain a sizable fraction of the observed variation in economic disparities across groups. Fourth, we show that ethnic-specific inequality in geographic endowments is also linked to under-development. PMID:27330223
Grosse Frie, Kirstin; Janssen, Christian
2009-01-01
Based on the theoretical and empirical approach of Pierre Bourdieu, a multivariate non-linear method is introduced as an alternative way to analyse the complex relationships between social determinants and health. The analysis is based on face-to-face interviews with 695 randomly selected respondents aged 30 to 59. Variables regarding socio-economic status, life circumstances, lifestyles, health-related behaviour and health were chosen for the analysis. In order to determine whether the respondents can be differentiated and described based on these variables, a non-linear canonical correlation analysis (OVERALS) was performed. The results can be described on three dimensions; Eigenvalues add up to the fit of 1.444, which can be interpreted as approximately 50 % of explained variance. The three-dimensional space illustrates correspondences between variables and provides a framework for interpretation based on latent dimensions, which can be described by age, education, income and gender. Using non-linear canonical correlation analysis, health characteristics can be analysed in conjunction with socio-economic conditions and lifestyles. Based on Bourdieus theoretical approach, the complex correlations between these variables can be more substantially interpreted and presented.
A fast multigrid algorithm for energy minimization under planar density constraints.
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.
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
Schüle, Steffen Andreas; Gabriel, Katharina M A; Bolte, Gabriele
2017-06-01
The environmental justice framework states that besides environmental burdens also resources may be social unequally distributed both on the individual and on the neighbourhood level. This ecological study investigated whether neighbourhood socioeconomic position (SEP) was associated with neighbourhood public green space availability in a large German city with more than 1 million inhabitants. Two different measures were defined for green space availability. Firstly, percentage of green space within neighbourhoods was calculated with the additional consideration of various buffers around the boundaries. Secondly, percentage of green space was calculated based on various radii around the neighbourhood centroid. An index of neighbourhood SEP was calculated with principal component analysis. Log-gamma regression from the group of generalized linear models was applied in order to consider the non-normal distribution of the response variable. All models were adjusted for population density. Low neighbourhood SEP was associated with decreasing neighbourhood green space availability including 200m up to 1000m buffers around the neighbourhood boundaries. Low neighbourhood SEP was also associated with decreasing green space availability based on catchment areas measured from neighbourhood centroids with different radii (1000m up to 3000 m). With an increasing radius the strength of the associations decreased. Social unequally distributed green space may amplify environmental health inequalities in an urban context. Thus, the identification of vulnerable neighbourhoods and population groups plays an important role for epidemiological research and healthy city planning. As a methodical aspect, log-gamma regression offers an adequate parametric modelling strategy for positively distributed environmental variables. Copyright © 2017 Elsevier GmbH. All rights reserved.
Solution of two-level variational inequality
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.
Optimum vibrating beams with stress and deflection constraints
NASA Technical Reports Server (NTRS)
Kamat, M. P.
1976-01-01
The fundamental frequency of vibration of an Euler-Bernoulli or a Timoshenko beam of a specified constant volume is maximized subject to the constraint that under a prescribed loading the maximum stress or maximum deflection at any point along the beam axis will not exceed a specified value. In contrast with the inequality constraint which controls the minimum cross-section, the present inequality constraints lead to more meaningful designs. The inequality constraint on stresses is as easily implemented as the minimum cross-section constraint but the inequality constraint on deflection uses a treatment which is an extension of the matrix partitioning technique of prescribing displacements in finite element analysis.
ERIC Educational Resources Information Center
Lang, Kurt
1981-01-01
Criticizes Michael Useem's argument that compulsory military service in the U.S. should not be reinstated because of the social inequities it fosters. Discusses social and economic pros and cons of the draft and voluntary military service. (GC)
NASA Astrophysics Data System (ADS)
Angulo, Raul E.; Hilbert, Stefan
2015-03-01
We explore the cosmological constraints from cosmic shear using a new way of modelling the non-linear matter correlation functions. The new formalism extends the method of Angulo & White, which manipulates outputs of N-body simulations to represent the 3D non-linear mass distribution in different cosmological scenarios. We show that predictions from our approach for shear two-point correlations at 1-300 arcmin separations are accurate at the ˜10 per cent level, even for extreme changes in cosmology. For moderate changes, with target cosmologies similar to that preferred by analyses of recent Planck data, the accuracy is close to ˜5 per cent. We combine this approach with a Monte Carlo Markov chain sampler to explore constraints on a Λ cold dark matter model from the shear correlation functions measured in the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). We obtain constraints on the parameter combination σ8(Ωm/0.27)0.6 = 0.801 ± 0.028. Combined with results from cosmic microwave background data, we obtain marginalized constraints on σ8 = 0.81 ± 0.01 and Ωm = 0.29 ± 0.01. These results are statistically compatible with previous analyses, which supports the validity of our approach. We discuss the advantages of our method and the potential it offers, including a path to model in detail (i) the effects of baryons, (ii) high-order shear correlation functions, and (iii) galaxy-galaxy lensing, among others, in future high-precision cosmological analyses.
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.
NASA Astrophysics Data System (ADS)
Bosch, Jessica; Stoll, Martin; Benner, Peter
2014-04-01
We consider the efficient solution of the Cahn-Hilliard variational inequality using an implicit time discretization, which is formulated as an optimal control problem with pointwise constraints on the control. By applying a semi-smooth Newton method combined with a Moreau-Yosida regularization technique for handling the control constraints we show superlinear convergence in function space. At the heart of this method lies the solution of large and sparse linear systems for which we propose the use of preconditioned Krylov subspace solvers using an effective Schur complement approximation. Numerical results illustrate the competitiveness of this approach.
LMI-Based Fuzzy Optimal Variance Control of Airfoil Model Subject to Input Constraints
NASA Technical Reports Server (NTRS)
Swei, Sean S.M.; Ayoubi, Mohammad A.
2017-01-01
This paper presents a study of fuzzy optimal variance control problem for dynamical systems subject to actuator amplitude and rate constraints. Using Takagi-Sugeno fuzzy modeling and dynamic Parallel Distributed Compensation technique, the stability and the constraints can be cast as a multi-objective optimization problem in the form of Linear Matrix Inequalities. By utilizing the formulations and solutions for the input and output variance constraint problems, we develop a fuzzy full-state feedback controller. The stability and performance of the proposed controller is demonstrated through its application to the airfoil flutter suppression.
QCD inequalities for hadron interactions.
Detmold, William
2015-06-05
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}.
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.
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
Pastukhova, S E
2000-02-28
We study the problem of small deformations of an elastic body with periodically distributed fissures, where one-sided constraints are imposed on the sides of the fissures; this problem is equivalent to a variational inequality. We prove that if the linear size of the period of the distribution of the fissures tends to zero, then the solutions of this problem converge in the L{sup 2}-norm to the solution of the homogenized problem, which is a non-linear boundary-value problem of elasticity theory for a domain without fissures.
NASA Astrophysics Data System (ADS)
Eliazar, Iddo
2016-09-01
Living in the era of "big-data" information, we are ubiquitously inundated by overabundances of sizes-non-negative numerical values representing count, score, length, area, volume, duration, mass, energy, etc. Datasets of sizes display numerous types of statistical variability that are commonly quantified either by the standard deviation, or by the Boltzmann-Gibbs-Shannon entropy. The standard deviation measures the sizes' Euclidean divergence from their mean, the Boltzmann-Gibbs-Shannon entropy measures the sizes' informational divergence from the benchmark of pure determinism, and both these gauges are one-dimensional. In this paper we overview a methodology that harnesses inequality in order to quantify statistical variability. The methodology follows a socioeconomic approach of measuring the sizes' inequality-their divergence from the benchmark of pure egalitarianism-and yields frameworks that gauge statistical variability in a multi-dimensional fashion. The aim of this overview is to serve both researchers and practitioners as a crash-introduction to the "harnessing inequality" methodology, and as a crash-manual to the implementation of this methodology.
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.
NASA Astrophysics Data System (ADS)
Eom, Myunghwan; Chwa, Dongkyoung; Baang, Dane
2015-06-01
This paper presents a robust disturbance observer-based feedback linearization control method using a fuzzy-based power change rate limiting method for a research reactor. The proposed controller has been designed for a nonlinear model of the reactor. Compared to the conventional control methods, the proposed scheme shows better control performance as it provides effective compensation for the steady-state error, due to a specific type of unmodeled dynamics. To cope with system uncertainties such as parameter uncertainties, unmodeled dynamics, and even external disturbance, we propose a robust disturbance observer-based feedback linearization controller. Moreover, the fuzzy-based power change rate limiting method is proposed, which is practically required for safe operation to limit the power change rate within a pre-designed safety range. In addition, a motor control input is considered and obtained by using the inverse model for the power control system. We show by numerical simulation that the proposed control law guarantees asymptotic stability as well as improved performance even in the presence of disturbance.
An inequality for longitudinal and transverse wave attenuation coefficients.
Norris, Andrew N
2017-01-01
Total absorption, defined as the net flux of energy out of a bounded region averaged over one cycle for time harmonic motion, must be non-negative when there are no sources of energy within the region. This passivity condition places constraints on the non-dimensional absorption coefficients of longitudinal and transverse waves, γL and γT, in isotropic linearly viscoelastic materials. Typically, γL, γT are small, in which case the constraints imply that coefficients of attenuation per unit length, αL, αT, must satisfy the inequality αL/αT≥4cT(3)/3cL(3) where cL, cT are the wave speeds. This inequality, which as far as the author is aware, has not been presented before, provides a relative bound on wave speed in terms of attenuation, or vice versa. It also serves as a check on the consistency of ultrasonic measurements from the literature, with most but not all of the data considered passing the positive absorption test.
On Random Betweenness Constraints
NASA Astrophysics Data System (ADS)
Goerdt, Andreas
Ordering constraints are analogous to instances of the satisfiability problem in conjunctive normalform, but instead of a boolean assignment we consider a linear ordering of the variables in question. A clause becomes true given a linear ordering iff the relative ordering of its variables obeys the constraint considered.
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.
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.
Direct linear algebraic deconvolution imaging of Compton telescope data.
NASA Astrophysics Data System (ADS)
Dixon, D. D.; Buchholz, J.; O'Neill, T. J.; Tümer, O. T.; White, R. S.; Zych, A. D.; Wheaton, W. A.
A general direct linear algebraic deconvolution method for imaging Compton gamma-ray telescope event data is described. This method gives an image of the gamma ray source distribution that is linearly related to the binned event data. Two algorithms for imposing the positivity constraint are investigated and compared; the Non-negative Least Squares method of Lawson and Hanson (1974) and the Inequality Constrained Generalized Least Squares method of Werner (1990). The latter is applied here to CGRO COMPTEL event data for Viewing Period # 1 centered on the Crab Nebula. Preliminary flux images and their statistical significant are presented.
NASA Astrophysics Data System (ADS)
Chiumenti, M.; Cervera, M.; Agelet de Saracibar, C.; Dialami, N.
2013-05-01
In this work a novel finite element technology based on a three-field mixed formulation is presented. The Variational Multi Scale (VMS) method is used to circumvent the LBB stability condition allowing the use of linear piece-wise interpolations for displacement, stress and pressure fields, respectively. The result is an enhanced stress field approximation which enables for stress-accurate results in nonlinear computational mechanics. The use of an independent nodal variable for the pressure field allows for an adhoc treatment of the incompressibility constraint. This is a mandatory requirement due to the isochoric nature of the plastic strain in metal forming processes. The highly non-linear stress field typically encountered in the Friction Stir Welding (FSW) process is used as an example to show the performance of this new FE technology. The numerical simulation of the FSW process is tackled by means of an Arbitrary-Lagrangian-Eulerian (ALE) formulation. The computational domain is split into three different zones: the work.piece (defined by a rigid visco-plastic behaviour in the Eulerian framework), the pin (within the Lagrangian framework) and finally the stirzone (ALE formulation). A fully coupled thermo-mechanical analysis is introduced showing the heat fluxes generated by the plastic dissipation in the stir-zone (Sheppard rigid-viscoplastic constitutive model) as well as the frictional dissipation at the contact interface (Norton frictional contact model). Finally, tracers have been implemented to show the material flow around the pin allowing a better understanding of the welding mechanism. Numerical results are compared with experimental evidence.
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
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.
Convergence results for elliptic quasivariational inequalities
NASA Astrophysics Data System (ADS)
Sofonea, Mircea; Benraouda, Ahlem
2017-02-01
In this paper, we state and prove various convergence results for a general class of elliptic quasivariational inequalities with constraints. Thus, we prove the convergence of the solution of a class of penalized problems to the solution of the original inequality, as the penalty parameter converges to zero. We also prove a continuous dependence result of the solution with respect the convex set of constraints. Then, we consider a mathematical model which describes the equilibrium of an elastic rod attached to a nonlinear spring. We derive the variational formulation of the model which is in a form of an elliptic quasivariational inequality for the displacement field. We prove the unique weak solvability of the model, and then we state and prove two convergence results and provide their corresponding mechanical interpretation.
Optimality of a dispersion inequality for the Compton effect on the nucleon
Chavleishvili, M.P.
1983-02-01
An analysis is made of the role of the kinematic constraint in obtaining a dispersion inequality for the Compton effect on the nucleon in the approach in which use is made of the t-channel helicity amplitudes. It is shown that the most restrictive (optimal) inequality can be obtained without allowance for the kinematic constraint at the point t = 0.
Isoperimetric inequality on conformally hyperbolic manifolds
NASA Astrophysics Data System (ADS)
Kesel'man, V. M.
2003-04-01
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.
Isoperimetric inequality on conformally hyperbolic manifolds
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.
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)
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)
Intradistrict Inequalities, I.
ERIC Educational Resources Information Center
Weinberg, Meyer
1980-01-01
This article discusses inequalities in the distribution of educational resources, with emphasis placed on inequalities within school districts. In the first section, racially-based inequalities within school districts are traced from the post Civil War period to the 1960s. Examples of unequal expenditures for black students given in this section…
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…
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…
Piecewise Integration of Differential Variational Inequality
NASA Astrophysics Data System (ADS)
Wang, Zhengyu; Wu, Xinyuan
2009-09-01
Differential variational inequality (DVI) is a new mathematical paradigm consisting of a system of ordinary differential equations and a parametric variational inequality problem as the constraints. The solution of DVI was shown at best piecewise differentiable, for which the existing integrators possess only convergence of order one. In this paper we present an algorithm of finding the pieces where the solution is differentiable, and propose applying the methods in the pieces for a moderate stepsize, while for smaller stepsize around the boundary of the pieces for achieving high accuracy. Numerical example of bridge collapse is given to illustrate the efficiency of our algorithms.
Goldstein, G.R.; Jaffe, R.L.; Ji, X.
1995-11-01
Various issues surrounding a recently proposed inequality among twist-two quark distributions in the nucleon are discussed. We provide a rigorous derivation of the inequality in QCD, including radiative corrections and scale dependence. We also give a more heuristic, but more physical derivation, from which we show that a similar inequality does not exist among twist-three quark distributions. We demonstrate that the inequality does not constrain the nucleon`s tensor charge. Finally we explore physical mechanisms for saturating the inequality, arguing it is unlikely to occur in nature.
Income inequality and happiness.
Oishi, Shigehiro; Kesebir, Selin; Diener, Ed
2011-09-01
Using General Social Survey data from 1972 to 2008, we found that Americans were on average happier in the years with less national income inequality than in the years with more national income inequality. We further demonstrated that this inverse relation between income inequality and happiness was explained by perceived fairness and general trust. That is, Americans trusted other people less and perceived other people to be less fair in the years with more national income inequality than in the years with less national income inequality. The negative association between income inequality and happiness held for lower-income respondents, but not for higher-income respondents. Most important, we found that the negative link between income inequality and the happiness of lower-income respondents was explained not by lower household income, but by perceived unfairness and lack of trust.
Students' Strategies and Difficulties: The Case of Algebraic Inequalities.
ERIC Educational Resources Information Center
Tsamir, P.; Almog, N.
2001-01-01
Describes a study on secondary school students' ways of thinking about linear, quadratic, rational, and square-root inequalities. Indicates that using graphic representations of parabolas when solving rational and quadratic inequalities usually yielded correct solutions and difficulties arose when students failed to reject the excluded values or…
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…
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…
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.
Income inequality and child maltreatment in the United States.
Eckenrode, John; Smith, Elliott G; McCarthy, Margaret E; Dineen, Michael
2014-03-01
To examine the relation between county-level income inequality and rates of child maltreatment. Data on substantiated reports of child abuse and neglect from 2005 to 2009 were obtained from the National Child Abuse and Neglect Data System. County-level data on income inequality and children in poverty were obtained from the American Community Survey. Data for additional control variables were obtained from the American Community Survey and the Health Resources and Services Administration Area Resource File. The Gini coefficient was used as the measure of income inequality. Generalized additive models were estimated to explore linear and nonlinear relations among income inequality, poverty, and child maltreatment. In all models, state was included as a fixed effect to control for state-level differences in victim rates. Considerable variation in income inequality and child maltreatment rates was found across the 3142 US counties. Income inequality, as well as child poverty rate, was positively and significantly correlated with child maltreatment rates at the county level. Controlling for child poverty, demographic and economic control variables, and state-level variation in maltreatment rates, there was a significant linear effect of inequality on child maltreatment rates (P < .0001). This effect was stronger for counties with moderate to high levels of child poverty. Higher income inequality across US counties was significantly associated with higher county-level rates of child maltreatment. The findings contribute to the growing literature linking greater income inequality to a range of poor health and well-being outcomes in infants and children.
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
Thévenot, Celine
2017-08-01
This article recalls the state of play of inequality levels and trends in OECD countries, with a special focus on Nordic countries. It sheds light on explaining the drivers of the rise in inequality and its economic consequences. It addresses in particular the issue of redistribution through taxes and transfers. It concludes with an overview of policy packages that should be considered to address the issue of rising inequalities.
A New Method for Motion Planning of Rotating Bodies under Multiple Constraints
NASA Astrophysics Data System (ADS)
Nishiyama, Takehiro; Yamada, Katsuhiko; Yoshikawa, Shoji
This paper presents a new method for generating motion profiles of rotating bodies, for example, the joint angle motion of mechanical systems such as space manipulators and antennas. In the planning of a motion from the given initial conditions to the final conditions, there are many constraints that should be considered, for example, actuator torque limits, rate limits, jerk limits, etc. Furthermore, flexibility of a system cannot be ignored in general. Vibration suppression is of great importance in some applications. For stationary boundary conditions (rest-to-rest cases), if the only constraint is the torque limit, a simple bang-bang type profile is the optimal one. However, if we consider more general boundary conditions, complex constraints, and vibration suppression conditions, the problem becomes considerably complicated. In this study, motion planning for a fixed motion time is considered. The control input or the acceleration of the motion is expressed as a linear superposition of triangle waves whose weight coefficients are determined in order to optimize the motion profile. In this formulation, all the boundary conditions and several constraints, including vibration suppression conditions, are expressed as linear equality and inequality constraints. Therefore, by appropriately setting the performance index, the problem becomes a linear programming problem and can be solved efficiently.
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…
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…
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.
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.
Linear programming for learning in neural networks
NASA Astrophysics Data System (ADS)
Raghavan, Raghu
1991-08-01
The authors have previously proposed a network of probabilistic cellular automata (PCAs) as part of an image recognition system designed to integrate model-based and data-driven approaches in a connectionist framework. The PCA arises from some natural requirements on the system which include incorporation of prior knowledge such as in inference rules, locality of inferences, and full parallelism. This network has been applied to recognize objects in both synthetic and in real data. This approach achieves recognition through the short-, rather than the long-time behavior of the dynamics of the PCA. In this paper, some methods are developed for learning the connection strengths by solving linear inequalities: the figures of merit are tendencies or directions of movement of the dynamical system. These 'dynamical' figures of merit result in inequality constraints on the connection strengths which are solved by linear (LP) or quadratic programs (QP). An algorithm is described for processing a large number of samples to determine weights for the PCA. The work may be regarded as either pointing out another application for constrained optimization, or as pointing out the need to extend the perceptron and similar methods for learning. The extension is needed because the neural network operates on a different principle from that for which the perceptron method was devised.
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…
Elders, M J
1993-01-01
America's children are stalked by race- and income-based inequities that demand our attention. Health care reform efforts that respect the needs of the entire child can diminish these inequities. Six prescriptions will help: universal early childhood education; comprehensive health and family life education; parental support; reinforcement of male responsibility; comprehensive school-based clinics; and opportunities for higher education.
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…
ERIC Educational Resources Information Center
Stoel, Reinoud D.; Garre, Francisca Galindo; Dolan, Conor; van den Wittenboer, Godfried
2006-01-01
The authors show how the use of inequality constraints on parameters in structural equation models may affect the distribution of the likelihood ratio test. Inequality constraints are implicitly used in the testing of commonly applied structural equation models, such as the common factor model, the autoregressive model, and the latent growth…
Robust Position Command Shaping against Plant Perturbations under Constraint of State Variables
NASA Astrophysics Data System (ADS)
Yamamoto, Masafumi; Iwasaki, Makoto; Mitsuhashi, Susumu; Ito, Kazuaki; Matsui, Nobuyuki
This paper presents a novel position command shaping approach for mechanical vibration suppression in mechatronic systems. Although conventional command shaping approaches can suppress the specified mechanical vibrations, mechanical and/or electrical perturbations in a plant may deteriorate the motion performance because the commands are generally shaped in a feedforward control manner. In this research, a linear matrix inequality (LMI) design framework is applied to eliminate the deterioration in positioning, where the robust command shaping against the plant perturbations can be directly achieved under the constraint of state variables in a system. The effectiveness of the proposed shaping has been verified by numerical simulations and experiments using a prototype.
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.
To what extent does immigration affect inequality?
NASA Astrophysics Data System (ADS)
Berman, Yonatan; Aste, Tomaso
2016-11-01
The current surge in income and wealth inequality in most western countries, along with the continuous immigration to those countries demand a quantitative analysis of the effect immigration has on economic inequality. This paper presents a quantitative analysis framework providing a way to calculate this effect. It shows that in most cases, the effect of immigration on wealth and income inequality is limited, mainly due to the relative small scale of immigration waves. For a large scale flow of immigrants, such as the immigration to the US, the UK and Australia in the past few decades, we estimate that 10 % ÷ 15 % of the wealth and income inequality increase can be attributed to immigration. The results demonstrate that immigration could possibly decrease inequality substantially, if the characteristics of the immigrants resemble the characteristics of the destination middle class population in terms of wealth or income. We empirically found that the simple linear relation ΔS = 0.18 ρ roughly describes the increase in the wealth share of the top 10 % due to immigration of a fraction ρ of the population.
Bonnesen-style Wulff isoperimetric inequality.
Zhang, Zengle; Zhou, Jiazu
2017-01-01
The Wulff isoperimetric inequality is a natural extension of the classical isoperimetric inequality (Green and Osher in Asian J. Math. 3:659-676 1999). In this paper, we establish some Bonnesen-style Wulff isoperimetric inequalities and reverse Bonnesen-style Wulff isoperimetric inequalities. Those inequalities obtained are extensions of known Bonnesen-style inequalities and reverse Bonnesen-style inequalities.
ERIC Educational Resources Information Center
Stiglitz, Joseph E.
1973-01-01
The author argues that the educational system is not the cause of inequality, raising the question of whether it is possible or even desirable to use the educational system to promote greater equality. (EH)
Generalized quasi variational inequalities
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.
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.
Bayesian methods for the analysis of inequality constrained contingency tables.
Laudy, Olav; Hoijtink, Herbert
2007-04-01
A Bayesian methodology for the analysis of inequality constrained models for contingency tables is presented. The problem of interest lies in obtaining the estimates of functions of cell probabilities subject to inequality constraints, testing hypotheses and selection of the best model. Constraints on conditional cell probabilities and on local, global, continuation and cumulative odds ratios are discussed. A Gibbs sampler to obtain a discrete representation of the posterior distribution of the inequality constrained parameters is used. Using this discrete representation, the credibility regions of functions of cell probabilities can be constructed. Posterior model probabilities are used for model selection and hypotheses are tested using posterior predictive checks. The Bayesian methodology proposed is illustrated in two examples.
An Intuitive Approach in Teaching Linear Programming in High School.
ERIC Educational Resources Information Center
Ulep, Soledad A.
1990-01-01
Discusses solving inequality problems involving linear programing. Describes the usual and alternative approaches. Presents an intuitive approach for finding a feasible solution by maximizing the objective function. (YP)
Educational Opportunities. Tackling Ethnic, Class and Gender Inequality through Research.
ERIC Educational Resources Information Center
Driessen, Geert, Ed.; Jungbluth, Paul, Ed.
This collection presents a cross section of research into the theme of equal opportunities in education in the Netherlands. The majority of articles are on the Dutch situation, which resembles that of other countries in many respects. Contributions include: (1) "Educational Inequality Research in the Netherlands. Conditions, Constraints and…
LPNORM: A linear programming normative analysis code
NASA Astrophysics Data System (ADS)
de Caritat, Patrice; Bloch, John; Hutcheon, Ian
1994-04-01
The computer code LPNORM implements the mathematical method of linear programming to calculate the mineralogical makeup of mineral mixtures, such as rock, sediment, or soil samples, from their bulk geochemical composition and from the mineralogical (or geochemical) composition of the contained minerals. This method simultaneously solves the set of linear equations governing the distribution of oxides into these minerals, subject to an objective function and a set of basic constraints. LPNORM allows the user to specify what minerals will be considered for normative analysis, what their composition is (in terms of mineral formula or geochemical composition), and whether to maximize mineral abundances, minimize slack variables (oxides that can not be accounted for), or do both at once in the objective function. Independent knowledge about the abundance of one or several of the minerals in the sample can be entered as additional equality or inequality constraints. Trial-and-error approach enables the user to "optimize" the composition of one or a few of the contained minerals. Results of comparative tests, highlighting the efficiency, as well as the shortcomings, of LPNORM are presented.
Nonlocal distillation based on multisetting Bell inequality
NASA Astrophysics Data System (ADS)
Ye, Xiang-Jun; Deng, Dong-Ling; Chen, Jing-Ling
2012-12-01
Inspired by the recent works of Foster [Phys. Rev. Lett.0031-900710.1103/PhysRevLett.102.120401 102, 120401 (2009)] and Brunner [Phys. Rev. Lett.0031-900710.1103/PhysRevLett.102.160403 102, 160403 (2009)], we present a nonlocality distillation protocol for two three-level (qutrit) systems in the framework of generalized nonsignaling theories. Our protocol is based on a three-setting Bell inequality. It works efficiently for a specific class of three-input-three-output nonlocal boxes. In the asymptotic limit, all these nonlocal boxes can be distilled to the maximally nonlocal box defined by the inequality and nonsignaling constraints. Then we introduce a contracting protocol that reduces these boxes to the so-called “correlated nonlocal boxes.” As a result, our three-input-three-output nonlocal boxes also make communication complexity trivial and appear very unlikely to exist in nature.
[Inequalities in health in Italy].
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
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.
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.
The box method for linear programming: Part 1, Basic theory
Zikan, K.; Cottle, R.W.
1987-06-01
This paper presents a new interior-point algorithm for linear programming where the constraints are all expressed as inequalities. Along with the concept of ''minimum-weight basis'', the algorithm features a novel mechanism for finding search directions. Unlike other interior-point methods which implicitly or explicitly involve optimization over ellipsoids for their direction-finding schemes, the one reported here uses ''boxes''. The corresponding subproblems are simple linear programs having closed form solutions. It is shown that the iterates generated by the algorithm converge to an extreme point of the feasible region. When this point is nondegenerate, it is optimal and reached within finitely any steps. The methodology introduced here also gives rise to a polyhedral subdivision of the problem's feasible region and in fact to the entire space of decision variables.
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
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…
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…
NASA Astrophysics Data System (ADS)
Allam, A. A.; Lin, F. C.; Share, P. E.; Ben-Zion, Y.; Vernon, F.; Schuster, G. T.; Karplus, M. S.
2016-12-01
We present earthquake data and statistical analyses from a month-long deployment of a linear array of 134 Fairfield three-component 5 Hz seismometers along the Clark strand of the San Jacinto fault zone in Southern California. With a total aperture of 2.4km and mean station spacing of 20m, the array locally spans the entire fault zone from the most intensely fractured core to relatively undamaged host rock on the outer edges. We recorded 36 days of continuous seismic data at 1000Hz sampling rate, capturing waveforms from 751 local events with Mw>0.5 and 43 teleseismic events with M>5.5, including two 600km deep M7.5 events along the Andean subduction zone. For any single local event on the San Jacinto fault, the central stations of the array recorded both higher amplitude and longer duration waveforms, which we interpret as the result of damage-related low-velocity structure acting as a broad waveguide. Using 271 San Jacinto events, we compute the distributions of three quantities for each station: maximum amplitude, mean amplitude, and total energy (the integral of the envelope). All three values become statistically lower with increasing distance from the fault, but in addition show a nonrandom zigzag pattern which we interpret as normal mode oscillations. This interpretation is supported by polarization analysis which demonstrates that the high-amplitude late-arriving energy is strongly vertically polarized in the central part of the array, consistent with Love-type trapped waves. These results, comprising nearly 30,000 separate coseismic waveforms, support the consistent interpretation of a 450m wide asymmetric damage zone, with the lowest velocities offset to the northeast of the mapped surface trace by 100m. This asymmetric damage zone has important implications for the earthquake dynamics of the San Jacinto and especially its ability to generate damaging multi-segment ruptures.
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.
Lorentz-invariant Bell's inequality
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.
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…
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…
Income inequality and obesity prevalence among OECD countries.
Su, Dejun; Esqueda, Omar A; Li, Lifeng; Pagán, José A
2012-07-01
Using recent pooled data from the World Health Organization Global Infobase and the World Factbook compiled by the Central Intelligence Agency of the United States, this study assesses the relation between income inequality and obesity prevalence among 31 OECD countries through a series of bivariate and multivariate linear regressions. The United States and Mexico well lead OECD countries in both obesity prevalence and income inequality. A sensitivity analysis suggests that the inclusion or exclusion of these two extreme cases can fundamentally change the findings. When the two countries are included, the results reveal a positive correlation between income inequality and obesity prevalence. This correlation is more salient among females than among males. Income inequality alone is associated with 16% and 35% of the variations in male and female obesity rates, respectively, across OECD countries in 2010. Higher levels of income inequality in the 2005-2010 period were associated with a more rapid increase in obesity prevalence from 2002 to 2010. These associations, however, virtually disappear when the US and Mexico have been excluded from the analysis. Findings from this study underscore the importance of assessing the impact of extreme cases on the relation between income inequality and health outcomes. The potential pathways from income inequality to the alarmingly high rates of obesity in the cases of the US and Mexico warrant further research.
Baum-Snow, Nathaniel; Pavan, Ronni
2013-01-01
Between 1979 and 2007 a strong positive monotonic relationship between wage inequality and city size has developed. This paper investigates the links between this emergent city size inequality premium and the contemporaneous nationwide increase in wage inequality. After controlling for the skill composition of the workforce across cities of different sizes, we show that at least 23 percent of the overall increase in the variance of log hourly wages in the United States from 1979 to 2007 is explained by the more rapid growth in the variance of log wages in larger locations relative to smaller locations. This influence occurred throughout the wage distribution and was most prevalent during the 1990s. More rapid growth in within skill group inequality in larger cities has been by far the most important force driving these city size specific patterns in the data. Differences in the industrial composition of cities of different sizes explain up to one-third of this city size effect. These results suggest an important role for agglomeration economies in generating changes in the wage structure during the study period. PMID:24954958
Distance, Education and Inequality
ERIC Educational Resources Information Center
Hamnett, Chris; Butler, Tim
2013-01-01
In this paper we examine the role which distance, in a variety of forms, can play in the reproduction, intensification or reduction of educational inequality in different types of school systems in different countries. This is a very broad issue, and in the paper we examine the ways in which distance to school has emerged as an important factor in…
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…
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…
Ethnicity, Denomination and Inequality.
ERIC Educational Resources Information Center
Greeley, Andrew M.
This report relies on a composite sample of 12 National Opinion Research Center surveys (with a total sample of 17,700) to trace out the basic outlines of the achievements of American denominational and ethnic groups. There are three fundamental questions addressed in this analysis: (1) whether there are inequalities of achievement among the…
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…
ERIC Educational Resources Information Center
Dahl, Robert A.
1996-01-01
Argues that political equality and democracy are attainable only through the distribution of access to political resources and the willingness to use them. Discusses the broad philosophical and sociological components that contribute to a system marked by advantage and inequalities, as well as opportunities for opposition and resistance. (MJP)
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…
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…
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…
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…
ERIC Educational Resources Information Center
Brickman, Philip
1977-01-01
People's judgments of fairness are related to varying degrees of uncertainty about their own resulting positions in society. When task assignments were made on the basis of ability, college students were much more willing to endorse inequality when they did not know their positions than when they did. (Author/EVH)
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)
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…
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…
Generalized Bell-inequality experiments and computation
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.
Nonlinear Model Predictive Control with Constraint Satisfactions for a Quadcopter
NASA Astrophysics Data System (ADS)
Wang, Ye; Ramirez-Jaime, Andres; Xu, Feng; Puig, Vicenç
2017-01-01
This paper presents a nonlinear model predictive control (NMPC) strategy combined with constraint satisfactions for a quadcopter. The full dynamics of the quadcopter describing the attitude and position are nonlinear, which are quite sensitive to changes of inputs and disturbances. By means of constraint satisfactions, partial nonlinearities and modeling errors of the control-oriented model of full dynamics can be transformed into the inequality constraints. Subsequently, the quadcopter can be controlled by an NMPC controller with the updated constraints generated by constraint satisfactions. Finally, the simulation results applied to a quadcopter simulator are provided to show the effectiveness of the proposed strategy.
Superselection from canonical constraints
NASA Astrophysics Data System (ADS)
Hall, Michael J. W.
2004-08-01
The evolution of both quantum and classical ensembles may be described via the probability density P on configuration space, its canonical conjugate S, and an ensemble Hamiltonian \\skew3\\tilde{H}[P,S] . For quantum ensembles this evolution is, of course, equivalent to the Schrödinger equation for the wavefunction, which is linear. However, quite simple constraints on the canonical fields P and S correspond to nonlinear constraints on the wavefunction. Such constraints act to prevent certain superpositions of wavefunctions from being realized, leading to superselection-type rules. Examples leading to superselection for energy, spin direction and 'classicality' are given. The canonical formulation of the equations of motion, in terms of a probability density and its conjugate, provides a universal language for describing classical and quantum ensembles on both continuous and discrete configuration spaces, and is briefly reviewed in an appendix.
Income inequality and population health: correlation and causality.
Babones, Salvatore J
2008-04-01
A large literature now exists on the cross-national correlation between income inequality and population health, but existing studies suffer from sparse data, poor operationalization of income inequality, and the use of low-power statistical models. This paper sets out to estimate the ecological correlation between income inequality and indicators of population health in a very broad panel of countries, to demonstrate that this relationship is largely non-artifactual, and to test whether this relationship might be causal. Gini coefficients of national income inequality in 1970 and 1995 are correlated with life expectancy, infant mortality rates, and murder rates, controlling for national income per capita. In cross-sectional analyses, inequality is significantly correlated with life expectancy, infant mortality, and (inconsistently) the murder rate. The health correlations are shown to be not primarily due to the "convexity effect" of the non-linear relationship between individual income and individual health, which seems to account for no more than one-third of the relationship between inequality and health, and likely much less. Change in inequality 1970-1995 is significantly related to change in life expectancy and infant mortality, suggesting a causal relationship, but these correlations are not robust with respect to sample or controls. It can be concluded that there is a strong, consistent, statistically significant, non-artifactual correlation between national income inequality and population health, but though there is some evidence that this relationship is causal, the relative stability of income inequality over time in most countries makes causality difficult to test.
Impact of Income Inequality on the Nation's Health.
López, Diego B; Loehrer, Andrew P; Chang, David C
2016-10-01
Income inequality in the United States has been increasing in recent decades. It is unclear whether income inequality has an independent effect on health outcomes, or whether it simply correlates with increasing levels of poverty. The goal of this study was to evaluate whether income inequality is significantly associated with US county health care expenditures and health care use. Cross-sectional analysis of county health expenditure data from the Health Resources and Services Administration's Area Resources File, county income inequality measures (Gini coefficient) from the Census' American Community Survey, and estimates of potentially preventable admissions and potentially discretionary procedures from the Nationwide Inpatient Sample (1998 to 2011). Datasets were linked via county Federal Information Processing Standard codes. Multivariable linear and Poisson regression analyses were performed at the county level adjusting for county characteristics. A total of 1,237 counties (of 3,144) were included. Income inequality was associated with higher health care expenditures, with each 1 percentage-point increase in county Gini coefficient associated with a US$40,008 increase in annual county Medicare cost (p = 0.003), and an increase of 174.7 total county Medicare inpatient days per year (p < 0.001). Even after accounting for poverty level and county characteristics, counties with higher inequality had higher potentially preventable admission (eg 4.86 rate ratio for low-birth-weight hospital admissions in the top income inequality quartile compared with bottom quartile; p < 0.001) and a higher incidence of potentially discretionary procedures (eg 1.79 rate ratio for prostatectomy for benign prostatic hyperplasia in the top income inequality quartile compared with bottom quartile; p < 0.001). Income inequality is independently associated with higher health care expenditures and more health care use, with increases in both potentially discretionary procedures and in
Multiphase interchange inequalities
NASA Astrophysics Data System (ADS)
Nesi, V.
1991-08-01
Phase interchange inequalities have been studied since the early work of Keller [J. Math. Phys. 5, 548 (1964)]. They constrain the effective conductivity of composite materials which are obtained from each other, for fixed configuration, by interchanging the position of the phases. Optimal results in this direction for the case of a two-phase composite are due to Keller in spatial dimension d=2 and to Avellaneda et al. [J. Appl. Phys. 63, 4989 (1988)] in dimension d=3. In this paper new inequalities in spatial dimension d=2 and d=3, which are valid when an arbitrary number of phases is present, are proven. When specialized to two-phase composites, they agree with those of Keller in d=2 and of Avellaneda et al. in d=3, respectively.
WEALTH INEQUALITY AND ACCUMULATION.
Killewald, Alexandra; Pfeffer, Fabian T; Schachner, Jared N
2017-07-01
Research on wealth inequality and accumulation and the data upon which it relies have expanded substantially in the twenty-first century. While the field has experienced rapid growth, conceptual and methodological challenges remain. We begin by discussing two major unresolved methodological concerns facing wealth research: how to address challenges to causal inference posed by wealth's cumulative nature and how to operationalize net worth, given its highly skewed nature. To underscore the need for continued empirical attention to net worth, we review trends in wealth levels and inequality and evaluate wealth's distinctiveness as an indicator of social stratification. Next, we provide an overview of data sources available for wealth research. We then review recent empirical evidence on the effects of wealth on other social outcomes, as well as research on the determinants of wealth. We close with a list of promising avenues for future research on wealth, its causes, and its consequences.
Mason, Christine
2017-08-23
What was the nature of the CPD activity, practice-related feedback and/or event and/or experience in your practice? The article outlined the health inequalities that people with serious mental illness (SMI) may experience. It acknowledged the barriers they often encounter in accessing healthcare services, and discussed how lifestyle behaviours, symptoms of mental illness and the side effects of medication can contribute to reduced life expectancy.
Addressing Environmental Health Inequalities.
Gouveia, Nelson
2016-08-27
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.
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…
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…
Huang, Gongsheng; Wang, Shengwei
2009-10-01
This paper studies the application of robust model predictive control (MPC) in a constraint process suffering from time-delay uncertainty. The process is described using a transfer function and sampled into a discrete model for computer control design. A polytope is firstly developed to describe the uncertain discrete model due to the process's time-delay uncertainty. Based on the proposed description, a linear matrix inequality (LMI) based MPC algorithm is employed and modified to design a robust controller for such a constraint process. In case studies, the effect of time-delay uncertainty on the control performance of a standard MPC algorithm is investigated, and the proposed description and the modified control algorithm are validated in the temperature control of a typical air-handling unit.
Income inequality and mortality in metropolitan areas of the United States.
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
Non-commutative Nash inequalities
Kastoryano, Michael; Temme, Kristan
2016-01-15
A set of functional inequalities—called Nash inequalities—are introduced and analyzed in the context of quantum Markov process mixing. The basic theory of Nash inequalities is extended to the setting of non-commutative L{sub p} spaces, where their relationship to Poincaré and log-Sobolev inequalities is fleshed out. We prove Nash inequalities for a number of unital reversible semigroups.
Non-commutative Nash inequalities
NASA Astrophysics Data System (ADS)
Kastoryano, Michael; Temme, Kristan
2016-01-01
A set of functional inequalities—called Nash inequalities—are introduced and analyzed in the context of quantum Markov process mixing. The basic theory of Nash inequalities is extended to the setting of non-commutative 𝕃p spaces, where their relationship to Poincaré and log-Sobolev inequalities is fleshed out. We prove Nash inequalities for a number of unital reversible semigroups.
Pre-vector variational inequality
Lin, Lai-Jiu
1994-12-31
Let X be a Hausdorff topological vector space, (Y, D) be an ordered Hausdorff topological vector space ordered by convex cone D. Let L(X, Y) be the space of all bounded linear operator, E {improper_subset} X be a nonempty set, T : E {yields} L(X, Y), {eta} : E {times} E {yields} E be functions. For x, y {element_of} Y, we denote x {not_lt} y if y - x intD, where intD is the interior of D. We consider the following two problems: Find x {element_of} E such that < T(x), {eta}(y, x) > {not_lt} 0 for all y {element_of} E and find x {element_of} E, < T(x), {eta}(y, x) > {not_gt} 0 for all y {element_of} E and < T(x), {eta}(y, x) >{element_of} C{sub p}{sup w+} = {l_brace} {element_of} L(X, Y) {vert_bar}< l, {eta}(x, 0) >{not_lt} 0 for all x {element_of} E{r_brace} where < T(x), y > denotes linear operator T(x) at y, that is T(x), (y). We called Pre-VVIP the Pre-vector variational inequality problem and Pre-VCP complementary problem. If X = R{sup n}, Y = R, D = R{sub +} {eta}(y, x) = y - x, then our problem is the well-known variational inequality first studies by Hartman and Stampacchia. If Y = R, D = R{sub +}, {eta}(y, x) = y - x, our problem is the variational problem in infinite dimensional space. In this research, we impose different condition on T(x), {eta}, X, and < T(x), {eta}(y, x) > and investigate the existences theorem of these problems. As an application of one of our results, we establish the existence theorem of weak minimum of the problem. (P) V - min f(x) subject to x {element_of} E where f : X {yields} Y si a Frechet differentiable invex function.
NASA Astrophysics Data System (ADS)
Rosenberg, D. E.; Alafifi, A.
2016-12-01
Water resources systems analysis often focuses on finding optimal solutions. Yet an optimal solution is optimal only for the modelled issues and managers often seek near-optimal alternatives that address un-modelled objectives, preferences, limits, uncertainties, and other issues. Early on, Modelling to Generate Alternatives (MGA) formalized near-optimal as the region comprising the original problem constraints plus a new constraint that allowed performance within a specified tolerance of the optimal objective function value. MGA identified a few maximally-different alternatives from the near-optimal region. Subsequent work applied Markov Chain Monte Carlo (MCMC) sampling to generate a larger number of alternatives that span the near-optimal region of linear problems or select portions for non-linear problems. We extend the MCMC Hit-And-Run method to generate alternatives that span the full extent of the near-optimal region for non-linear, non-convex problems. First, start at a feasible hit point within the near-optimal region, then run a random distance in a random direction to a new hit point. Next, repeat until generating the desired number of alternatives. The key step at each iterate is to run a random distance along the line in the specified direction to a new hit point. If linear equity constraints exist, we construct an orthogonal basis and use a null space transformation to confine hits and runs to a lower-dimensional space. Linear inequity constraints define the convex bounds on the line that runs through the current hit point in the specified direction. We then use slice sampling to identify a new hit point along the line within bounds defined by the non-linear inequity constraints. This technique is computationally efficient compared to prior near-optimal alternative generation techniques such MGA, MCMC Metropolis-Hastings, evolutionary, or firefly algorithms because search at each iteration is confined to the hit line, the algorithm can move in one
Bell Inequalities and Group Symmetry
NASA Astrophysics Data System (ADS)
Bolonek-Lasoń, Katarzyna
2017-03-01
Recently the method based on irreducible representations of finite groups has been proposed as a tool for investigating the more sophisticated versions of Bell inequalities (V. Ugǔr Gűney, M. Hillery, Phys. Rev. A90, 062121 ([2014]) and Phys. Rev. A91, 052110 ([2015])). In the present paper an example based on the symmetry group S 4 is considered. The Bell inequality violation due to the symmetry properties of regular tetrahedron is described. A nonlocal game based on the inequalities derived is described and it is shown that the violation of Bell inequality implies that the quantum strategies outperform their classical counterparts.
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.
The use of linear programming in optimization of HDR implant dose distributions.
Jozsef, Gabor; Streeter, Oscar E; Astrahan, Melvin A
2003-05-01
The introduction of high dose rate brachytherapy enabled optimization of dose distributions to be used on a routine basis. The objective of optimization is to homogenize the dose distribution within the implant while simultaneously satisfying dose constraints on certain points. This is accomplished by varying the time the source dwells at different locations. As the dose at any point is a linear function of the dwell times, a linear programming approach seems to be a natural choice. The dose constraints are inherently linear inequalities. Homogeneity requirements are linearized by minimizing the maximum deviation of the doses at points inside the implant from a prescribed dose. The revised simplex method was applied for the solution of this linear programming problem. In the homogenization process the possible source locations were chosen as optimization points. To avoid the problem of the singular value of the dose at a source location from the source itself we define the "self-contribution" as the dose at a small distance from the source. The effect of varying this distance is discussed. Test cases were optimized for planar, biplanar and cylindrical implants. A semi-irregular, fan-like implant with diverging needles was also investigated. Mean central dose calculation based on 3D Delaunay-triangulation of the source locations was used to evaluate the dose distributions. The optimization method resulted in homogeneous distributions (for brachytherapy). Additional dose constraints--when applied--were satisfied. The method is flexible enough to include other linear constraints such as the inclusion of the centroids of the Delaunay-triangulation for homogenization, or limiting the maximum allowable dwell time.
[Inequities in access to information and inequities in health].
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.
Salary Inequities and/or Differentials: Identification and Adjustment.
ERIC Educational Resources Information Center
Wall, Robert E.
A study was designed to develop a method for identifying and ameliorating faculty salary differentials or inequities at a moderately large (500 faculty members) master's-degree-granting institution. A linear regression model was chosen to determine the relationship between the observed salary and the independent variables of rank, years…
Tightness of correlation inequalities with no quantum violation
NASA Astrophysics Data System (ADS)
Ramanathan, Ravishankar; Quintino, Marco Túlio; Sainz, Ana Belén; Murta, Gláucia; Augusiak, Remigiusz
2017-01-01
We study the faces of the set of quantum correlations, i.e., the Bell and noncontextuality inequalities without any quantum violation. First, we investigate the question of whether every proper (facet-defining) Bell inequality for two parties, other than the trivial ones from positivity, normalization, and no-signaling, can be violated by quantum correlations, i.e., whether the classical Bell polytope or the smaller correlation polytope share any facets with their respective quantum sets. To do this, we develop a recently derived bound on the quantum value of linear games based on the norms of game matrices to give a simple sufficient condition to identify linear games with no quantum advantage. Additionally we show how this bound can be extended to the general class of unique games. We then show that the paradigmatic examples of correlation Bell inequalities with no quantum violation, namely the nonlocal computation games, do not constitute facet-defining Bell inequalities, not even for the correlation polytope. We also extend this to an arbitrary prime number of outcomes for a specific class of these games. We then study the faces in the simplest Clauser-Horne-Shimony-Holt Bell scenario of binary dichotomic measurements, and identify edges in the set of quantum correlations in this scenario. Finally, we relate the noncontextual polytope of single-party correlation inequalities with the cut polytope CUT(∇ G ) , where G denotes the compatibility graph of observables in the contextuality scenario and ∇ G denotes the suspension graph of G . We observe that there exist facet-defining noncontextuality inequalities with no quantum violation, and furthermore that this set of inequalities is beyond those implied by the consistent exclusivity principle.
Frauendiener, Joerg
2001-09-03
The purpose of this Letter is to point out an argument which may ultimately lead to a rigorous proof of the Penrose inequality in the general case. The argument is a variation of Geroch's original proposal for a proof of the positive-energy theorem which was later adapted by Jang and Wald to apply to initial data sets containing apparent horizons. The new input is to dispense with the a priori restriction to an initial data set and to use the four-dimensional structure of spacetime in an essential way.
Method of expanding hyperspheres - an interior algorithm for linear programming problems
Chandrupatla, T.
1994-12-31
A new interior algorithm using some properties of hyperspheres is proposed for the solution of linear programming problems with inequality constraints: maximize c{sup T} x subject to Ax {<=} b where c and rows of A are normalized in the Euclidean sense such that {parallel} c {parallel} = {radical}c{sup T}c = 1 {parallel} a{sub i} {parallel} {radical} A{sub i}A{sub i}{sup T} = 1 for i = 1 to m. The feasible region in the polytope bounded by the constraint planes. We start from an interior point. We pass a plane normal to c until it touches a constraint plane. Then the sphere is expanded so that it keeps contact with the previously touched planes and the expansion proceeds till it touches another plane. The procedure is continued till the sphere touches the c-plane and n constraint planes. We move to the center of the sphere and repeat the process. The interior maximum is reached when the radius of the expanded sphere is less than a critical value say {epsilon}. Problems of direction finding, determination of incoming constraint, sphere jamming, and evaluation of the initial feasible point are discussed.
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.
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.
Inequality in Disability in Bangladesh
Tareque, Md. Ismail; Begum, Sharifa; Saito, Yasuhiko
2014-01-01
Objective To investigate inequality in disability in Bangladesh. Methods The study used both household level and individual level data from a large nationally representative data set, Bangladesh’s Household Income and Expenditure Survey - 2010. Principal component analysis was used to construct a wealth index based on household assets from household level data. Then, using data from 49,809 individuals aged 5 years and over, chi-square tests and logistic regression were performed to test the association between wealth level and disability. Findings Women and older people are significantly more likely to report having disabilities than men and younger people. For middle and rich families, respectively, there is a 14 percent lower likelihood of reporting disabilities than for poor families. Changes in the probability of having disabilities are linear with increasing wealth. In addition, the study identifies some significant factors affecting disability, namely, age, sex, education, marital status, and place of residence including divisional differences. Conclusion In Bangladesh, worse health among the poor argues for policies prioritizing this group while at the same time giving special attention to women and the elderly. PMID:25075513
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.
Nonconvex Policy Search Using Variational Inequalities.
Zhan, Yusen; Ammar, Haitham Bou; Taylor, Matthew E
2017-10-01
Policy search is a class of reinforcement learning algorithms for finding optimal policies in control problems with limited feedback. These methods have been shown to be successful in high-dimensional problems such as robotics control. Though successful, current methods can lead to unsafe policy parameters that potentially could damage hardware units. Motivated by such constraints, we propose projection-based methods for safe policies. These methods, however, can handle only convex policy constraints. In this letter, we propose the first safe policy search reinforcement learner capable of operating under nonconvex policy constraints. This is achieved by observing, for the first time, a connection between nonconvex variational inequalities and policy search problems. We provide two algorithms, Mann and two-step iteration, to solve the above problems and prove convergence in the nonconvex stochastic setting. Finally, we demonstrate the performance of the algorithms on six benchmark dynamical systems and show that our new method is capable of outperforming previous methods under a variety of settings.
Convergence of neural networks for programming problems via a nonsmooth Lojasiewicz inequality.
Forti, Mauro; Nistri, Paolo; Quincampoix, Marc
2006-11-01
This paper considers a class of neural networks (NNs) for solving linear programming (LP) problems, convex quadratic programming (QP) problems, and nonconvex QP problems where an indefinite quadratic objective function is subject to a set of affine constraints. The NNs are characterized by constraint neurons modeled by ideal diodes with vertical segments in their characteristic, which enable to implement an exact penalty method. A new method is exploited to address convergence of trajectories, which is based on a nonsmooth Lojasiewicz inequality for the generalized gradient vector field describing the NN dynamics. The method permits to prove that each forward trajectory of the NN has finite length, and as a consequence it converges toward a singleton. Furthermore, by means of a quantitative evaluation of the Lojasiewicz exponent at the equilibrium points, the following results on convergence rate of trajectories are established: (1) for nonconvex QP problems, each trajectory is either exponentially convergent, or convergent in finite time, toward a singleton belonging to the set of constrained critical points; (2) for convex QP problems, the same result as in (1) holds; moreover, the singleton belongs to the set of global minimizers; and (3) for LP problems, each trajectory converges in finite time to a singleton belonging to the set of global minimizers. These results, which improve previous results obtained via the Lyapunov approach, are true independently of the nature of the set of equilibrium points, and in particular they hold even when the NN possesses infinitely many nonisolated equilibrium points.
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 contemporary…
Economic Factors of Russian Inequality
ERIC Educational Resources Information Center
Bobkov, Vyacheslav N.; Vakhtina, Margarita A.; Simonova, Marina V.
2016-01-01
The relevance of the researched problem is connected with the high level of economic inequality in Russia. The article goal is to show that the current Russian institutional system is not directed to decrease the economic inequality but on the contrary it continues to make and deepen it. The leading approach to study of this problem is the…
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 contemporary…
The Geography of Gender Inequality.
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.
The Geography of Gender Inequality
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
Environmental Inequality in Metropolitan America
Downey, Liam; Dubois, Summer; Hawkins, Brian; Walker, Michelle
2009-01-01
This study compares the environmental hazard burden experienced by Blacks, Hispanics, Pacific Islanders, Native Americans, Asian Americans, and Whites in each of the 329 metropolitan areas in the continental United States, using toxicity-weighted air pollutant concentration data drawn from the Environmental Protection Agency's Risk-Screening Environmental Indicators project to determine whether and to what degree environmental inequality exists in each of these metropolitan areas. After demonstrating that environmental inequality outcomes vary widely across metropolitan areas and that each group in the analysis experiences a high pollution disadvantage in multiple metropolitan areas and a medium pollution disadvantage in many metropolitan areas, the authors test three hypotheses that make predictions about the role that residential segregation and racial income inequality play in producing environmental inequality. Using logistic regression models to test these hypotheses, the authors find that residential segregation and racial income inequality are relatively poor predictors of environmental inequality outcomes, that residential segregation can increase and decrease racial/ethnic group proximity to environmental hazards, and that the roles income inequality and residential segregation play in producing environmental inequality vary from one racial/ethnic group to another. PMID:19960094
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…
Health inequalities: a global perspective.
Barreto, Mauricio Lima
2017-07-01
The objective of this article is to present health inequalities as a global problem which afflicts the populations of the poorest countries, but also those of the richest countries, and whose persistence represents one of the most serious and challenging health problems worldwide. Two components of global inequalities are highlighted: inequalities between groups within the same society, and inequalities between nations. The understanding that many of these inequalities are unjust, and therefore inequities, is largely derived from the inequalities that are identified between the various social groups of a given society. Inequalities between different societies and nations, while relevant and often of greater magnitude, are not always considered to be unjust. There have been several proposed solutions, which vary according to different theoretical interpretations and explanations. At the global level, the most plausible thesis has focused on improving global governance mechanisms. While that latter are attractive and have some arguments in their favor, they are insufficient because they do not incorporate an understanding of how the historical process of the constitution of the nations occurred and the importance of the position of each country in the global productive system.
Global Oral Health Inequalities
Pitts, N.; Amaechi, B.; Niederman, R.; Acevedo, A.-M.; Vianna, R.; Ganss, C.; Ismail, A.; Honkala, E.
2011-01-01
The IADR Global Oral Health Inequalities Task Group on Dental Caries has synthesized current evidence and opinion to identify a five-year implementation and research agenda which should lead to improvements in global oral health, with particular reference to the implementation of current best evidence as well as integrated action to reduce caries and health inequalities between and within countries. The Group determined that research should: integrate health and oral health wherever possible, using common risk factors; be able to respond to and influence international developments in health, healthcare, and health payment systems as well as dental prevention and materials; and exploit the potential for novel funding partnerships with industry and foundations. More effective communication between and among the basic science, clinical science, and health promotion/public health research communities is needed. Translation of research into policy and practice should be a priority for all. Both community and individual interventions need tailoring to achieve a more equal and person-centered preventive focus and reduce any social gradient in health. Recommendations are made for both clinical and public health implementation of existing research and for caries-related research agendas in clinical science, health promotion/public health, and basic science. PMID:21490233
Regional inequalities in mortality.
Illsley, R; Le Grand, J
1993-01-01
STUDY OBJECTIVE--To examine the hypothesis of sustained and persistent inequalities in health between British regions and to ask how far they are a consequence of using standardised mortality ratios as the tool of measurement. DESIGN, SETTING AND PARTICIPANTS--Data are regional, age specific death rates at seven points in time from 1931 to 1987-89 for the British regions, reconstructed to make them comparable with the 1981 regional definitions. Log variance is used to measure inequality; regional rankings are also used. MEASUREMENTS AND MAIN RESULTS--There has been a substantial convergence in age specific death rates between regions in younger but not in older age groups. In younger age groups the historic north/south gradient has disappeared; it persists in older groups. CONCLUSIONS--Use of standardised mortality ratios obscures differences in the convergence rates of age specific death rates between regions. Simple conclusions about the persistence of a north/south divide are not justified. Different processes of change seem to be at work in different age groups. PMID:8120497
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.
Addressing Environmental Health Inequalities
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
Thermodynamic Constraints Improve Metabolic Networks.
Krumholz, Elias W; Libourel, Igor G L
2017-08-08
In pursuit of establishing a realistic metabolic phenotypic space, the reversibility of reactions is thermodynamically constrained in modern metabolic networks. The reversibility constraints follow from heuristic thermodynamic poise approximations that take anticipated cellular metabolite concentration ranges into account. Because constraints reduce the feasible space, draft metabolic network reconstructions may need more extensive reconciliation, and a larger number of genes may become essential. Notwithstanding ubiquitous application, the effect of reversibility constraints on the predictive capabilities of metabolic networks has not been investigated in detail. Instead, work has focused on the implementation and validation of the thermodynamic poise calculation itself. With the advance of fast linear programming-based network reconciliation, the effects of reversibility constraints on network reconciliation and gene essentiality predictions have become feasible and are the subject of this study. Networks with thermodynamically informed reversibility constraints outperformed gene essentiality predictions compared to networks that were constrained with randomly shuffled constraints. Unconstrained networks predicted gene essentiality as accurately as thermodynamically constrained networks, but predicted substantially fewer essential genes. Networks that were reconciled with sequence similarity data and strongly enforced reversibility constraints outperformed all other networks. We conclude that metabolic network analysis confirmed the validity of the thermodynamic constraints, and that thermodynamic poise information is actionable during network reconciliation. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.
Optical mechanical analogy and nonlinear nonholonomic constraints.
Bloch, Anthony M; Rojo, Alberto G
2016-02-01
In this paper we establish a connection between particle trajectories subject to a nonholonomic constraint and light ray trajectories in a variable index of refraction. In particular, we extend the analysis of systems with linear nonholonomic constraints to the dynamics of particles in a potential subject to nonlinear velocity constraints. We contrast the long time behavior of particles subject to a constant kinetic energy constraint (a thermostat) to particles with the constraint of parallel velocities. We show that, while in the former case the velocities of each particle equalize in the limit, in the latter case all the kinetic energies of each particle remain the same.
Chauvel, Louis; Leist, Anja K
2015-11-14
Health inequalities reflect multidimensional inequality (income, education, and other indicators of socioeconomic position) and vary across countries and welfare regimes. To which extent there is intergenerational transmission of health via parental socioeconomic status has rarely been investigated in comparative perspective. The study sought to explore if different measures of stratification produce the same health gradient and to which extent health gradients of income and of social origins vary with level of living and income inequality. A total of 299,770 observations were available from 18 countries assessed in EU-SILC 2005 and 2011 data, which contain information on social origins. Income inequality (Gini) and level of living were calculated from EU-SILC. Logit rank transformation provided normalized inequalities and distributions of income and social origins up to the extremes of the distribution and was used to investigate net comparable health gradients in detail. Multilevel random-slope models were run to post-estimate best linear unbiased predictors (BLUPs) and related standard deviations of residual intercepts (median health) and slopes (income-health gradients) per country and survey year. Health gradients varied across different measures of stratification, with origins and income producing significant slopes after controls. Income inequality was associated with worse average health, but income inequality and steepness of the health gradient were only marginally associated. Linear health gradients suggest gains in health per rank of income and of origins even at the very extremes of the distribution. Intergenerational transmission of status gains in importance in countries with higher income inequality. Countries differ in the association of income inequality and income-related health gradient, and low income inequality may mask health problems of vulnerable individuals with low status. Not only income inequality, but other country characteristics such
Income inequality and school bullying: multilevel study of adolescents in 37 countries.
Elgar, Frank J; Craig, Wendy; Boyce, William; Morgan, Antony; Vella-Zarb, Rachel
2009-10-01
To examine the association between income inequality and school bullying in an international sample of preadolescents and to test for mediation of this association by the availability of social support from families, peers, and schools. The study used economic data from the 2006 United Nations Development Program Human Development Report and survey data from the 2005/2006 Health Behavior in School-aged Children (HBSC) study which included 66,910 11-year-olds in 37 countries. Ecological correlations tested associations between income inequality and bullying among countries. Multilevel linear and ordinal regression analyses tested the effects of income inequality on perceived social support and bullying others at school. Income inequality was associated with rates of bullying among the 37 countries (r = .62). Multilevel analyses indicated that each standard deviation increase in income inequality corresponded with more frequent bullying by males (odds ratio = 1.17) and females (odds ratio = 1.24), less family support and school support but more peer support. Social support from families and schools was associated with less bullying after differences in wealth were taken into account; however, social support did not account for the association between income inequality and bullying. Countries with high income inequality have more school bullying among preadolescents than countries with low income inequality. Further study is needed to understand the mechanisms that account for this association. Findings suggest that adolescents in areas of wide income inequality-not only those in deprived schools and neighborhoods- should be a focus of anti-bullying campaigns.
Well-posedness of the time-varying linear electromagnetic initial-boundary value problem
NASA Astrophysics Data System (ADS)
Xie, Li; Lei, Yin-Zhao
2007-09-01
The well-posedness of the initial-boundary value problem of the time-varying linear electromagnetic field in a multi-medium region is investigated. Function spaces are defined, with Faraday's law of electromagnetic induction and the initial-boundary conditions considered as constraints. Gauss's formula applied to a multi-medium region is used to derive the energy-estimating inequality. After converting the initial-boundary conditions into homogeneous ones and analysing the characteristics of an operator introduced according to the total current law, the existence, uniqueness and stability of the weak solution to the initial-boundary value problem of the time-varying linear electromagnetic field are proved.
Socioeconomic Inequality in Childhood Obesity.
Moradi, Ghobad; Mostafavi, Farideh; Azadi, Namamali; Esmaeilnasab, Nader; Ghaderi, Ebrahim
2017-08-15
The aim of this study was to assess the socioeconomic inequalities in obesity and overweight in children aged 10 to 12 yr old. A cross-sectional study. This study was conducted on 2506 children aged 10 to 12 yr old in the city of Sanandaj, western Iran in 2015. Body mass index (BMI) was calculated. Considering household situation and assets, socioeconomic status (SES) of the subjects was determined using Principal Component Analysis (PCA). Concentration Index was used to measure inequality and Oaxaca decomposition was used to determine the share of different determinants of inequality. The prevalence of overweight was 24.1% (95% CI: 22.4, 25.7). 11.5% (95% CI: 10.0, 12.0) were obese. The concentration index for overweight and obesity, respectively, was 0.10 (95% CI: 0.05, 0.15), and 0.07 (95% CI:0.00, 0.14) which indicated inequality and a higher prevalence of obesity and overweight in higher SES. The results of Oaxaca decomposition suggested that socioeconomic factors accounted for 75.8% of existing inequalities. Residential area and mother education were the most important causes of inequality. To reduce inequalities in childhood obesity, mother education must be promoted and special attention must be paid to residential areas and children gender.
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…
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…
Income inequality and income segregation.
Reardon, Sean F; Bischoff, Kendra
2011-01-01
This article investigates how the growth in income inequality from 1970 to 2000 affected patterns of income segregation along three dimensions: the spatial segregation of poverty and affluence, race-specific patterns of income segregation, and the geographic scale of income segregation. The evidence reveals a robust relationship between income inequality and income segregation, an effect that is larger for black families than for white families. In addition, income inequality affects income segregation primarily through its effect on the large-scale spatial segregation of affluence rather than by affecting the spatial segregation of poverty or by altering small-scale patterns of income segregation.
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.
Correlations in star networks: from Bell inequalities to network inequalities
NASA Astrophysics Data System (ADS)
Tavakoli, Armin; Olivier Renou, Marc; Gisin, Nicolas; Brunner, Nicolas
2017-07-01
The problem of characterizing classical and quantum correlations in networks is considered. Contrary to the usual Bell scenario, where distant observers share a physical system emitted by one common source, a network features several independent sources, each distributing a physical system to a subset of observers. In the quantum setting, the observers can perform joint measurements on initially independent systems, which may lead to strong correlations across the whole network. In this work, we introduce a technique to systematically map a Bell inequality to a family of Bell-type inequalities bounding classical correlations on networks in a star-configuration. Also, we show that whenever a given Bell inequality can be violated by some entangled state ρ, then all the corresponding network inequalities can be violated by considering many copies of ρ distributed in the star network. The relevance of these ideas is illustrated by applying our method to a specific multi-setting Bell inequality. We derive the corresponding network inequalities, and study their quantum violations.
On the linear programming bound for linear Lee codes.
Astola, Helena; Tabus, Ioan
2016-01-01
Based on an invariance-type property of the Lee-compositions of a linear Lee code, additional equality constraints can be introduced to the linear programming problem of linear Lee codes. In this paper, we formulate this property in terms of an action of the multiplicative group of the field [Formula: see text] on the set of Lee-compositions. We show some useful properties of certain sums of Lee-numbers, which are the eigenvalues of the Lee association scheme, appearing in the linear programming problem of linear Lee codes. Using the additional equality constraints, we formulate the linear programming problem of linear Lee codes in a very compact form, leading to a fast execution, which allows to efficiently compute the bounds for large parameter values of the linear codes.
Maximum Tsallis entropy with generalized Gini and Gini mean difference indices constraints
NASA Astrophysics Data System (ADS)
Khosravi Tanak, A.; Mohtashami Borzadaran, G. R.; Ahmadi, J.
2017-04-01
Using the maximum entropy principle with Tsallis entropy, some distribution families for modeling income distribution are obtained. By considering income inequality measures, maximum Tsallis entropy distributions under the constraint on generalized Gini and Gini mean difference indices are derived. It is shown that the Tsallis entropy maximizers with the considered constraints belong to generalized Pareto family.
Poverty and health sector inequalities.
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
Economic Inequality Predicts Biodiversity Loss
Mikkelson, Gregory M.; Gonzalez, Andrew; Peterson, Garry D.
2007-01-01
Human activity is causing high rates of biodiversity loss. Yet, surprisingly little is known about the extent to which socioeconomic factors exacerbate or ameliorate our impacts on biological diversity. One such factor, economic inequality, has been shown to affect public health, and has been linked to environmental problems in general. We tested how strongly economic inequality is related to biodiversity loss in particular. We found that among countries, and among US states, the number of species that are threatened or declining increases substantially with the Gini ratio of income inequality. At both levels of analysis, the connection between income inequality and biodiversity loss persists after controlling for biophysical conditions, human population size, and per capita GDP or income. Future research should explore potential mechanisms behind this equality-biodiversity relationship. Our results suggest that economic reforms would go hand in hand with, if not serving as a prerequisite for, effective conservation. PMID:17505535
Income inequality in today's China.
Xie, Yu; Zhou, Xiang
2014-05-13
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.
Poverty and health sector inequalities.
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.
[Social inequality in home care].
Möller, A; Osterfeld, A; Büscher, A
2013-06-01
Social inequality in Germany is discussed primarily with regard to educational or social welfare issues. There is a political consensus that more action should be taken to ensure equality of chances and fulfillment of basic needs for everyone. In long-term care these considerations have not yet taken place and there are hardly any research studies in this field. However, the startling rise of the need for long-term care will definitely require a discussion of social inequality in various care arrangements. To learn more about social inequality in home care, a qualitative approach was used and 16 home care nurses were interviewed. Our study shows that many care recipients face numerous problems they cannot handle on their own, which may even worsen their situation. In addition, the results reveal that facing social inequalities place a burden on nurses and influence their work performance.
Health inequalities--gender perspective.
Ostrowska, Antonina
2012-01-01
Health inequalities have become recently one of the major concerns of European health policy. Observed differences in health status of men and women are also frequently discussed within this framework, and are becoming a subject of growing interest of researchers. Clinical and epidemiological researches document male-female health differences, trying to explain them within bio-medical model. However, apart of biological (sex) divergence, health inequalities reflect differences in social roles, social status and culturally established patterns and stereotypes of femininity and masculinity (gender differences). The article, using sociological perspective, attempts to show that observed differences in man's and women's health may be attributable to the differing sociocultural and structural arrangements, social support and lifestyle factors of both genders. As a result, many of these differences are of inequality character. Another dimension of inequality discussed in this article is the way man and women are treated by the institution of medicine.
Inequality, Unemployment and Contemporary Europe.
ERIC Educational Resources Information Center
Sen, Amartya
1997-01-01
Unemployment has social costs such as psychological harm, social exclusion, family breakdown, and loss of political voice. It can exacerbate inequality and technological conservatism. Reducing unemployment would contribute to solving many of Europe's social ills. (SK)
Penrose inequality and apparent horizons
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.
NASA Astrophysics Data System (ADS)
Flemming, Jens; Hofmann, Bernd
2011-08-01
In this paper, we enlighten the role of variational inequalities for obtaining convergence rates in Tikhonov regularization of nonlinear ill-posed problems with convex penalty functionals under convexity constraints in Banach spaces. Variational inequalities are able to cover solution smoothness and the structure of nonlinearity in a uniform manner, not only for unconstrained but, as we indicate, also for constrained Tikhonov regularization. In this context, we extend the concept of projected source conditions already known in Hilbert spaces to Banach spaces, and we show in the main theorem that such projected source conditions are to some extent equivalent to certain variational inequalities. The derived variational inequalities immediately yield convergence rates measured by Bregman distances.
NASA Astrophysics Data System (ADS)
Su, Yi; Wang, Feifeng; Lu, Yufeng; Huang, Huimin; Xia, Xiaofei
2017-09-01
This paper is based on affine function equation of the grid and OPF problem, discusses the equivalent of some inequality constraints variables optimizing. Further, we propose the model of injection current and set up the constraint sensitivity index of affine characteristics. The index can be used to identify the central point voltage and effective inequality of the system automatically. And then we can know how to compensate reactive power of the corresponding generator node and control the voltage to ensure the quality of the system voltage. When checking the effective inequalities we introduce cross-solving method of power flow. This provide a different idea for solving the power flow. The paper uses the results of the IEEE5 node examples to illustrate the validity and practicality of the proposed method.
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…
Ranking Forestry Investments With Parametric Linear Programming
Paul A. Murphy
1976-01-01
Parametric linear programming is introduced as a technique for ranking forestry investments under multiple constraints; it combines the advantages of simple tanking and linear programming as capital budgeting tools.
Early-life income inequality and adolescent health and well-being.
Elgar, Frank J; Gariépy, Geneviève; Torsheim, Torbjørn; Currie, Candace
2017-02-01
A prevailing hypothesis about the association between income inequality and poor health is that inequality intensifies social hierarchies, increases stress, erodes social and material resources that support health, and subsequently harms health. However, the evidence in support of this hypothesis is limited by cross-sectional, ecological studies and a scarcity of developmental studies. To address this limitation, we used pooled, multilevel data from the Health Behaviour in School-aged Children study to examine lagged, cumulative, and trajectory associations between early-life income inequality and adolescent health and well-being. Psychosomatic symptoms and life satisfaction were assessed in surveys of 11- to 15-year-olds in 40 countries between 1994 and 2014. We linked these data to national Gini indices of income inequality for every life year from 1979 to 2014. The results showed that exposure to income inequality from 0 to 4 years predicted psychosomatic symptoms and lower life satisfaction in females after controlling lifetime mean income inequality, national per capita income, family affluence, age, and cohort and period effects. The cumulative income inequality exposure in infancy and childhood (i.e., average Gini index from birth to age 10) related to lower life satisfaction in female adolescents but not to symptoms. Finally, individual trajectories in early-life inequality (i.e., linear slopes in Gini indices from birth to 10 years) related to fewer symptoms and higher life satisfaction in females, indicating that earlier exposures mattered more to predicting health and wellbeing. No such associations with early-life income inequality were found in males. These results help to establish the antecedent-consequence conditions in the association between income inequality and health and suggest that both the magnitude and timing of income inequality in early life have developmental consequences that manifest in reduced health and well-being in adolescent girls.
[Inequality, poverty and obesity].
Ferreira, Vanessa Alves; Silva, Aline Elizabeth; Rodrigues, Chrystiellen Ayana Aparecida; Nunes, Nádia Lúcia Almeida; Vigato, Tássia Cassimiro; Magalhães, Rosana
2010-06-01
National studies have been demonstrating the positive relationship among inequality, poverty and obesity revealing the singularities and complexity of the nutritional transition in Brazil. In this direction, the women constitute a vulnerable group to the dynamics of the obesity in the poverty context. Such fact imposes the theoretical deepening and the accomplishment of researches that make possible a larger approach with the phenomenon in subject. In this perspective, the study analyzed the daily life of poor and obese women, users of basic units of health of the city of Diamantina, Vale do Jequitinhonha, Minas Gerais State. The results revealed the complex relationship between feminine obesity and poverty. The cultural and material aspects of life, as well as the different feeding and body conceptions that demonstrated to be fundamental elements for the analysis of the multiple faces of the obesity among the investigated group. Facing these results it is appropriate to encourage public policies that promote equity widening the access of those groups to the main resources for the prevention and combat of obesity.
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
Nutrition inequities in Canada.
Tarasuk, Valerie; Fitzpatrick, Sandra; Ward, Heather
2010-04-01
In Canada, increased morbidity and shorter life expectancy have been found among those with lower incomes and lower levels of education, but there has been little examination of socioeconomic variation in food and nutrient intake. Using data from the 2004 Canadian Community Health Survey, we examined the relationship between household income and education level and adults' and children's intakes of energy, fibre, micronutrients, and number of servings consumed of food groups from Canada's Food Guide. To explore the public health significance of observed associations, we estimated the prevalence of inadequacy for selected nutrients for adults, stratifying by household income, education level, and sex. We found that a higher household income adequacy and (or) higher levels of education were associated with increased consumption of milk and alternatives, and vegetables and fruit, and significantly higher vitamin, mineral, and fibre intakes among both adults and children. The prevalence of inadequate nutrient intakes among adults was higher among adults with the lowest level of income adequacy or educational attainment, compared with others. Our results suggest that the nutritional quality of Canadians' food intakes is, in part, a function of their social position. The impact of policy and program interventions needs to be examined across socioeconomic strata to ensure that actions reduce rather than exacerbate nutrition inequities.
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.
Population growth, inequality and poverty.
Rodgers, G
1983-01-01
In this discussion of population growth, inequality, and poverty, the type of relationships that can be observed in intercountry comparisons are explored, reviewing the findings of several other authors, presenting some new estimates using an International Labor Office data bank, considering some basic conceptual problems, and examining some of the theoretical and empirical issues that call for investigation at the national level. Intercountry comparisons, despite their limitations, appear to be the easiest starting point for empirical analysis. The approach adopted by most researchers has been to select 1 or more population indicators and a measure of national income inequality and to explain intercountry differences in 1 or both of these variables in terms of each other and of other indicators of economic and social development. Underlying this methodology is the assumption that there are aspects of demographic and economic change that are common to all countries included in the study, so that differences between countries give some guide to the likely evolution over time within any 1 country. This can be accepted at best with reservations, but given the scarcity of data on the evolution of inequality over time, a working hypothesis of this type appears unavoidable. But, as many of the factors likely to cause population growth and inequality operate over extended periods of time, a dynamic model is indicated. A simpler model, which pays particular attention to lags and variations over time, may generate new insights. A summary of the results of a new international cross-section analysis set up on these lines is presented. Results suggest that contrary to expectations, reducing population growth does not seem to generate longterm benefits for the poor in this model, though some short term gains are found. Increasing equality does appear to generate some decline in population growth, as well as persistent gains in incomes among the poor, but the reductions in
Is income inequality related to childhood dental caries in rich countries?
Bernabé, Eduardo; Hobdell, Martin H
2010-02-01
The aim of this study was to assess the correlates of income and income inequality with dental caries in a sample of all countries, as well as in rich countries alone. In this ecological study, the authors analyzed national data on income, income inequality and dental caries from 48 countries. Of them, 22 were rich countries (according to World Bank criteria). The authors determined income by gross national income (GNI) per capita (formerly known as gross national product) and income inequality by the Gini coefficient (a measure of income inequality on a scale between 0 and 1). They assessed dental caries according to the decayed, missing, filled teeth (dmft) index in 5- to 6-year-old children. The authors used Pearson and partial correlation coefficients to examine the linear associations of income and income inequality with dental caries. GNI per capita, but not the Gini coefficient, was inversely correlated with the dmft index in the 48 countries. However, the results showed an opposite pattern when analyses were restricted to rich countries (that is, the dmft index was significantly correlated with the Gini coefficient but not with GNI per capita). These findings support the income inequality hypothesis that beyond a certain level of national income, the relationship between income and the population's health is weak. Income inequality was correlated more strongly with dental caries than was income in rich countries. Among rich countries, income inequality is a stronger determinant of childhood dental caries than is absolute income.
Rising U.S. income inequality, gender and individual self-rated health, 1972-2004.
Zheng, Hui
2009-11-01
The effect of income inequality on health has been a contested topic among social scientists. Most previous research is based on cross-sectional comparisons rather than temporal comparisons. Using data from the General Social Survey and the U.S. Census Bureau, this study examines how rising income inequality affects individual self-rated health in the U.S. from 1972 to 2004. Data are analyzed using hierarchical generalized linear models. The findings suggest a significant association between income inequality and individual self-rated health. The dramatic increase in income inequality from 1972 to 2004 increases the odds of worse self-rated health by 9.4 percent. These findings hold for three measures of income inequality: the Gini coefficient, the Atkinson Index, and the Theil entropy index. Results also suggest that overall income inequality and gender-specific income inequality harm men's, but not women's, self-rated health. These findings also hold for the three measures of income inequality. These findings suggest that inattention to gender composition may explain apparent discrepancies across previous studies.
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.
Stability analysis of delayed neural networks via a new integral inequality.
Yang, Bin; Wang, Juan; Wang, Jun
2017-04-01
This paper focuses on stability analysis for neural networks systems with time-varying delays. A more general auxiliary function-based integral inequality is established and some improved delay-dependent stability conditions formulated in terms of linear matrix inequalities (LMIs) are derived by employing a suitable Lyapunov-Krasovskii functional (LKF) and the novel integral inequality. Three well-known application examples are provided to demonstrate the effectiveness and improvements of the proposed method. Copyright © 2017 Elsevier Ltd. All rights reserved.
Inequalities in premature mortality in Britain: observational study from 1921 to 2007
Dorling, Danny; Smith, George Davey
2010-01-01
Objective To report on the extent of inequality in premature mortality as measured between geographical areas in Britain. Design Observational study of routinely collected mortality data and public records. Population subdivided by age, sex, and geographical area (parliamentary constituencies from 1991 to2007, pre-1974 local authorities over a longer time span). Setting Great Britain. Participants Entire population aged under 75 from 1990 to 2007, and entire population aged under 65 in the periods 1921-39, 1950-3, 1959-63, 1969-73, and 1981-2007. Main outcome measure Relative index of inequality (RII) and ratios of inequality in age-sex standardised mortality ratios under ages 75 and 65. The relative index of inequality is the relative rate of mortality for the hypothetically worst-off compared with the hypothetically best-off person in the population, assuming a linear association between socioeconomic position and risk of mortality. The ratio of inequality is the ratio of the standardised mortality ratio of the most deprived 10% to the least deprived 10%. Results When measured by the relative index of inequality, geographical inequalities in age-sex standardised rates of mortality below age 75 have increased every two years from 1990-1 to 2006-7 without exception. Over this period the relative index of inequality increased from 1.61 (95% confidence interval 1.52 to 1.69) in 1990-1 to 2.14 (2.02 to 2.27) in 2006-7. Simple ratios indicated a brief period around 2001 when a small reduction in inequality was recorded, but this was quickly reversed and inequalities up to the age of 75 have now reached the highest levels reported since at least 1990. Similarly, inequalities in mortality ratios under the age of 65 improved slightly in the early years of this century but the latest figures surpass the most extreme previously reported. Comparison of crudely age-sex standardised rates for those below age 65 from historical records showed that geographical inequalities in
The Interplay between socioeconomic inequalities and clinical oral health.
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
Nonequilibrium fluctuation-dissipation inequality and nonequilibrium uncertainty principle.
Fleming, C H; Hu, B L; Roura, Albert
2013-07-01
The fluctuation-dissipation relation is usually formulated for a system interacting with a heat bath at finite temperature, and often in the context of linear response theory, where only small deviations from the mean are considered. We show that for an open quantum system interacting with a nonequilibrium environment, where temperature is no longer a valid notion, a fluctuation-dissipation inequality exists. Instead of being proportional, quantum fluctuations are bounded below by quantum dissipation, whereas classically the fluctuations vanish at zero temperature. The lower bound of this inequality is exactly satisfied by (zero-temperature) quantum noise and is in accord with the Heisenberg uncertainty principle, in both its microscopic origins and its influence upon systems. Moreover, it is shown that there is a coupling-dependent nonequilibrium fluctuation-dissipation relation that determines the nonequilibrium uncertainty relation of linear systems in the weak-damping limit.
[Social inequality in medical rehabilitation].
Deck, Ruth; Hofreuter-Gätgens, Kerstin
2016-02-01
The analysis of inequalities in health care provision in Germany is of high sociopolitical relevance. For medical rehabilitation, which is an essential part of health care provision, only a few studies exist. With the example of psychosomatic and orthopedic medical rehabilitation, the present article investigates how features of social inequality influence different aspects of medical rehabilitation. The database consists of a written survey on the quality assurance of medical rehabilitation in northern Germany that includes 687 patients aged between 21 and 87 years. Aspects of the access to rehabilitation (e.g., the motivation for application), the process (participation in therapies) and the outcomes (e.g., subjective health and occupational risk) of rehabilitation were investigated in relation to social inequality. Social inequality was measured by means of a social class index. For the analysis, Chi-squared tests, t tests and a repeated measures analysis of variance, adjusted for sex and age, were conducted. Initially, the analyses indicate that social inequality is of minor importance for access to rehabilitation and processes within rehabilitation. As subjective health is unequally distributed at the beginning of rehabilitation, however, equal treatment has to be discussed critically in terms of demand-driven treatment. In rehabilitation outcome distinct differences between social classes exist. To reduce these differences, rehabilitation aftercare close to the individual's living environment is necessary, which promotes the empowerment of vulnerable social groups in burdensome living conditions.
Spin observables and spin structure functions: Inequalities and dynamics
NASA Astrophysics Data System (ADS)
Artru, Xavier; Elchikh, Mokhtar; Richard, Jean-Marc; Soffer, Jacques; Teryaev, Oleg V.
2009-01-01
Model-independent identities and inequalities which relate the various spin observables of collisions in nuclear and particle physics are reviewed in a unified formalism. Their physical interpretation and their implications for dynamical models are also discussed. These constraints between observables can be obtained in several ways: from the explicit expression of the observables in terms of a set of helicity or transversity amplitudes, a non-trivial algebraic exercise which can be preceded by numerical simulation with randomly chosen amplitudes, from anticommutation relations, or from the requirement that any polarisation vector is less than unity. The most powerful tool is the positivity of the density matrices describing the spins in the initial or final state of the reaction or its crossed channels. The inequalities resulting from positivity need to be projected to single out correlations between two or three observables. The quantum aspects of the information carried by spins, in particular entanglement, are considered when deriving and discussing the constraints. Several examples are given, with a comparison with experimental data in some cases. For the exclusive reactions, the cases of the strangeness-exchange proton-antiproton scattering and the photoproduction of pseudoscalar mesons are treated in some detail: all triples of observables are constrained, and new results are presented for the allowed domains. The positivity constraints for total cross sections and for the simplest observables of single-particle inclusive reactions are reviewed. They also apply to spin-dependent structure functions and parton distributions, both integrated or transverse-momentum dependent. The corresponding inequalities are shown to be preserved by the evolution equations of quantum chromodynamics.
Sparse linear programming subprogram
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.
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.
STRUCTURAL RACISM AND HEALTH INEQUITIES
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
[Globalization, inequity and Chagas disease].
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.
Martingale Rosenthal inequalities in symmetric spaces
Astashkin, S V
2014-12-31
We establish inequalities similar to the classical Rosenthal inequalities for sequences of martingale differences in general symmetric spaces; a central role is played here by the predictable quadratic characteristic of a martingale. Bibliography: 26 titles.
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.
Children's Perceptions of Social Resource Inequality.
Elenbaas, Laura; Killen, Melanie
2017-01-01
Children's perceptions of social resource inequalities were investigated by measuring spontaneous explanations for race-based disparities in access to societal resources. Fifth graders (N = 139, M = 11.14 years, SD = .61 years) viewed animated vignettes depicting hypothetical resource inequalities between institutions serving children of African-American and European-American background. Children frequently explained disparities in terms of institutions' differing financial resources, revealing awareness that economic inequalities often underlie groups' differential access to societal resources. Further, children attributed inequalities to preferential treatment more often when they witnessed African-Americans at a disadvantage than when they witnessed European-Americans at a disadvantage, demonstrating awareness that racial minority groups are more likely to experience restricted access to resources. Finally, children who reasoned about preferential treatment judged inequality, and actions that perpetuated inequality, more negatively than children who attributed inequalities to institutions' differing needs, revealing a link between awareness of discrimination and rejection of social inequalities.
Educational inequality in the occurrence of abdominal obesity: Pró-Saúde Study
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
Measures of Inequality: Application to Happiness in Nations
Kalmijn, W. M.
2010-01-01
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
Measures of Inequality: Application to Happiness in Nations.
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
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.
Remainder terms for some quantum entropy inequalities
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.
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.…
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.…
Extended Rearrangement Inequalities and Applications to Some Quantitative Stability Results
NASA Astrophysics Data System (ADS)
Lemou, Mohammed
2016-12-01
In this paper, we prove a new functional inequality of Hardy-Littlewood type for generalized rearrangements of functions. We then show how this inequality provides quantitative stability results of steady states to evolution systems that essentially preserve the rearrangements and some suitable energy functional, under minimal regularity assumptions on the perturbations. In particular, this inequality yields a quantitative stability result of a large class of steady state solutions to the Vlasov-Poisson systems, and more precisely we derive a quantitative control of the L 1 norm of the perturbation by the relative Hamiltonian (the energy functional) and rearrangements. A general non linear stability result has been obtained by Lemou et al. (Invent Math 187:145-194, 2012) in the gravitational context, however the proof relied in a crucial way on compactness arguments which by construction provides no quantitative control of the perturbation. Our functional inequality is also applied to the context of 2D-Euler systems and also provides quantitative stability results of a large class of steady-states to this system in a natural energy space.
A Variant of the Topkis-Veinott Method for Solving Inequality Constrained Optimization Problems
Birge, J. R.; Qi, L.; Wei, Z.
2000-05-15
In this paper we give a variant of the Topkis-Veinott method for solving inequality constrained optimization problems. This method uses a linearly constrained positive semidefinite quadratic problem to generate a feasible descent direction at each iteration. Under mild assumptions, the algorithm is shown to be globally convergent in the sense that every accumulation point of the sequence generated by the algorithm is a Fritz-John point of the problem. We introduce a Fritz-John (FJ) function, an FJ1 strong second-order sufficiency condition (FJ1-SSOSC), and an FJ2 strong second-order sufficiency condition (FJ2-SSOSC), and then show, without any constraint qualification (CQ), that (i) if an FJ point z satisfies the FJ1-SSOSC, then there exists a neighborhood N(z) of z such that, for any FJ point y element of N(z) {l_brace}z {r_brace} , f{sub 0}(y) {ne} f{sub 0}(z) , where f{sub 0} is the objective function of the problem; (ii) if an FJ point z satisfies the FJ2-SSOSC, then z is a strict local minimum of the problem. The result (i) implies that the entire iteration point sequence generated by the method converges to an FJ point. We also show that if the parameters are chosen large enough, a unit step length can be accepted by the proposed algorithm.
Bayesian Evaluation of inequality-constrained Hypotheses in SEM Models using Mplus.
van de Schoot, Rens; Hoijtink, Herbert; Hallquist, Michael N; Boelen, Paul A
2012-10-01
Researchers in the behavioural 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 question they would like an answer to is "Is the Hypothesis Correct" or "Is the hypothesis incorrect?". We demonstrate a Bayesian approach to compare an inequality-constrained hypothesis with its complement in an SEM framework. The method is introduced and its utility is illustrated by means of an example. Furthermore, the influence of the specification of the prior distribution is examined. Finally, it is shown how the approach proposed can be implemented using Mplus.
Simple and tight monogamy relations for a class of Bell inequalities
NASA Astrophysics Data System (ADS)
Augusiak, Remigiusz
2017-01-01
Physical principles constrain the way nonlocal correlations can be distributed among distant parties in a Bell-type experiment. These constraints are usually expressed by monogamy relations that bound the amount of Bell inequality violation observed by a set of parties by the violation observed by a different set of parties. Here we show that the no-signaling principle yields simple and tight monogamy relations for an important class of bipartite and multipartite Bell inequalities. We also link these trade-offs to the guessing probability—a key quantity in device-independent information processing.
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.
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…
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…
Rural Schools: Resource Inequalities Persist.
ERIC Educational Resources Information Center
Walters, Donald L.
In spite of 1983 legislation intended to equalize financial differences among school districts, Pennsylvania continues to experience inequalities in school funding. A study of Pennsylvania school finance over a 10-year period, 1984-85 through 1993-94, examined differences in spending among the 25 lowest spending districts (Lo-25) and the 25…
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…
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…
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…
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…
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…
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…
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…
Dynamic Constraint Satisfaction with Reasonable Global Constraints
NASA Technical Reports Server (NTRS)
Frank, Jeremy
2003-01-01
Previously studied theoretical frameworks for dynamic constraint satisfaction problems (DCSPs) employ a small set of primitive operators to modify a problem instance. They do not address the desire to model problems using sophisticated global constraints, and do not address efficiency questions related to incremental constraint enforcement. In this paper, we extend a DCSP framework to incorporate global constraints with flexible scope. A simple approach to incremental propagation after scope modification can be inefficient under some circumstances. We characterize the cases when this inefficiency can occur, and discuss two ways to alleviate this problem: adding rejection variables to the scope of flexible constraints, and adding new features to constraints that permit increased control over incremental propagation.
Thermodynamic optimization under topological constraints
NASA Astrophysics Data System (ADS)
Balakumar, Thevika
Computational thermodynamics is a powerful tool for solving practically important problems including the design of new materials and the analysis of their internal and external stability. This thesis contributes to computational thermodynamics by proposing several practical solutions to eliminate the so-called thermodynamic artifacts rather frequently found in thermodynamic assessments. First, a method is developed to eliminate the artifacts such as inverted miscibility gaps in the liquid phase at high-temperatures and reappearance of the liquid phase at low-temperatures or reappearance of a solid phase at elevated temperatures. This method is based on introducing a sufficiently dense mesh of knots (not related to experimental points utilized in the optimization) and ensuring that specific inequality conditions (topological constraints) governing the appearance of the phase diagram are satisfied in these knots. A feasibility of the approach proposed is exemplified by carrying out a re-optimization of the Mg-Sb system. Generally re-optimization of a system would take months to get the optimized results. Hence, to minimize time needed to get rid of artifacts, two different quick correction methods are developed to eliminate the unrealistic inverted miscibility gap in the liquid phase at elevated temperatures. Both methods employ optimization under topological constraints via controlling the sign of the second derivative of the Gibbs energy. Their applicability is exemplified on the Sn-Zr system. Also, a theoretical study was done on undulate phase boundaries. Usually, an inflection point on a phase boundary is considered as an unambiguous indication that one of the phases participating in the equilibrium is internally unstable, i.e., that it is prone to phase separation. It has been generally assumed that an inflection point may occur only if the thermodynamic model of this phase contains an excess Gibbs energy term. It is shown that in contrast to this assumption
Hicken, Margaret T
2015-08-15
Racial and ethnic inequalities in blood pressure and hypertension have been well documented, but their causes remain unclear, making efforts to reduce these inequalities challenging. In this issue of the Journal, Basu et al. (Am J Epidemiol. 2015;182(4):345-353) address this gap in our knowledge by using an econometric approach to examine the role of 4 conventional risk factors for hypertension. Their results suggest that targeting certain risk factors will reduce racial inequalities in the prevalence of hypertension. However, racial differences in modifiable risk factors are enmeshed within disparate socioenvironmental contexts which are in turn determined by inequalities in the distribution of social, economic, and political resources and constraints. A small but growing body of literature suggests that targeting the intermediate risk factors that link racial group membership to hypertension, rather than the context or the inequalities in the distribution of resources and constraints, will ultimately result in little change in hypertension inequalities, increase these inequalities, or even create inequalities in poor mental health. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Reichert, A; Jacobs, R
2017-08-14
Duration of untreated psychosis (DUP) is an important measure of access to care as it predicts prognosis and treatment outcomes. Little is known about potential socioeconomic inequalities in DUP. The aim of this study was to investigate inequalities in DUP associated with socioeconomic deprivation in a national cohort in England. We analysed a cohort of 887 patients with a first-episode in psychosis using the administrative Mental Health Services Dataset in England for 2012/13-2014/15. We used a Generalised Linear Model to account for non-linearity in DUP and looked at inequalities across the whole distribution of DUP using quantile regression. The median DUP was 22 days (mean = 74 days) with considerable variations between and within the 31 hospital providers. We found evidence of significant inequalities regarding the level of socioeconomic deprivation. Patients living in the second, third and fourth deprived neighbourhood quintiles faced a 36, 24 and 31 day longer DUP than patients from the least deprived neighbourhoods. Inequalities were more prevalent in higher quantiles of the DUP distribution. Unemployment prolonged DUP by 40 days. Having been in contact with mental health care services prior to the psychosis start significantly reduced the DUP by up to 53 days. Socioeconomic deprivation is an important factor in explaining inequalities in DUP. Policies to improve equitable access to care should particularly focus on preventing very long delays in treatment and target unemployed patients as well as people that have not been in contact with any mental health professional in the past.
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.
Geometric inequalities from phase space translations
NASA Astrophysics Data System (ADS)
Huber, Stefan; König, Robert; Vershynina, Anna
2017-01-01
We establish a quantum version of the classical isoperimetric inequality relating the Fisher information and the entropy power of a quantum state. The key tool is a Fisher information inequality for a state which results from a certain convolution operation: the latter maps a classical probability distribution on phase space and a quantum state to a quantum state. We show that this inequality also gives rise to several related inequalities whose counterparts are well-known in the classical setting: in particular, it implies an entropy power inequality for the mentioned convolution operation as well as the isoperimetric inequality and establishes concavity of the entropy power along trajectories of the quantum heat diffusion semigroup. As an application, we derive a Log-Sobolev inequality for the quantum Ornstein-Uhlenbeck semigroup and argue that it implies fast convergence towards the fixed point for a large class of initial states.
Torche, Florencia
2010-05-01
Educational assortative mating and economic inequality are likely to be endogenously determined, but very little research exists on their empirical association. Using census data and log-linear and log-multiplicative methods, I compare the patterns of educational assortative mating in Brazil, Chile, and Mexico, and explore the association between marital sorting and earnings inequality across countries. The analysis finds substantial variation in the strength of specific barriers to educational intermarriage between countries, and a close association between these barriers and the earnings gaps across educational categories within countries. This finding suggests an isomorphism between assortative mating and economic inequality. Furthermore, educational marital sorting is remarkably symmetric across gender in spite of the different resources that men and women bring to the union. This study highlights the limitations of using single aggregate measures of spousal educational resemblance (such as the correlation coefficient between spouses' schooling) to capture variation in assortative mating and its relationship with socioeconomic inequality.
TORCHE, FLORENCIA
2010-01-01
Educational assortative mating and economic inequality are likely to be endogenously determined, but very little research exists on their empirical association. Using census data and log-linear and log-multiplicative methods, I compare the patterns of educational assortative mating in Brazil, Chile, and Mexico, and explore the association between marital sorting and earnings inequality across countries. The analysis finds substantial variation in the strength of specific barriers to educational intermarriage between countries, and a close association between these barriers and the earnings gaps across educational categories within countries. This finding suggests an isomorphism between assortative mating and economic inequality. Furthermore, educational marital sorting is remarkably symmetric across gender in spite of the different resources that men and women bring to the union. This study highlights the limitations of using single aggregate measures of spousal educational resemblance (such as the correlation coefficient between spouses’ schooling) to capture variation in assortative mating and its relationship with socioeconomic inequality. PMID:20608107
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
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.
Adjusting inequalities for detection-loophole-free steering experiments
NASA Astrophysics Data System (ADS)
Sainz, Ana Belén; Guryanova, Yelena; McCutcheon, Will; Skrzypczyk, Paul
2016-09-01
We study the problem of certifying quantum steering in a detection-loophole-free manner in experimental situations that require postselection. We present a method to find the modified local-hidden-state bound of steering inequalities in such a postselected scenario. We then present a construction of linear steering inequalities in arbitrary finite dimension and show that they certify steering in a loophole-free manner as long as the detection efficiencies are above the known bound below which steering can never be demonstrated. We also show how our method extends to the scenarios of multipartite steering and Bell nonlocality, in the general case where there can be correlations between the losses of the different parties. In both cases we present examples to demonstrate the techniques developed.
Averaging schemes for solving fixed point and variational inequality problems
Magnanti, T.L.; Perakis, G.
1994-12-31
In this talk we develop and study averaging schemes for solving fixed point and variational inequality problems. Typically, researchers have established convergence results for methods that solve these problems by establishing contractive estimates for the underlying algorithmic maps. In this talk we establish global convergence results using nonexpansive estimates. After first establishing convergence for a general iterative scheme for computing fixed points, we consider applications to projection and relaxation algorithms for solving variational inequality problems and to a generalized steepest descent method for solving systems of equations. As part of our development, we also establish a new interpretation of a norm condition typically used for establishing convergence of linearization schemes, by associating it with a strong-f-monotonicity condition. We conclude by applying these results to congested transportation networks.
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…
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.
NASA Astrophysics Data System (ADS)
Liu, Zhenhai; Migórski, Stanisław; Zeng, Shengda
2017-10-01
In this paper, we firstly introduce a complicated system obtained by mixing a nonlinear evolutionary partial differential equation and a mixed variational inequality in infinite dimensional Banach spaces in the case where the set of constraints is not necessarily bounded and the problem is driven by nonlocal boundary conditions, which is called partial differential variational inequality ((PDVI), for short). Then, we show that the solution set of the mixed variational inequality involved in problem (PDVI) is nonempty, bounded, closed and convex. Moreover, the upper semicontinuity and measurability properties for set-valued mapping U : [ 0 , T ] ×E2 → Cbv (E1) (see (3.7), below) are also established. Finally, several existence results for (PDVI) are obtained by using a fixed point theorem for condensing set-valued operators and theory of measure of noncompactness.
Violation of a temporal bell inequality for single spins in a diamond defect center.
Waldherr, G; Neumann, P; Huelga, S F; Jelezko, F; Wrachtrup, J
2011-08-26
Quantum nonlocality has been experimentally investigated by testing different forms of Bell's inequality, yet a loophole-free realization has not been achieved up to now. Much less explored are temporal Bell inequalities, which are not subject to the locality assumption, but impose a constraint on the system's time correlations. In this Letter, we report on the experimental violation of a temporal Bell's inequality using a nitrogen-vacancy (NV) defect in diamond and provide a novel quantitative test of quantum coherence. Such a test requires strong control over the system, and we present a new technique to initialize the electronic state of the NV with high fidelity, a necessary requirement also for reliable quantum information processing and/or the implementation of protocols for quantum metrology.
The relation between Hardy's non-locality and violation of Bell inequality
NASA Astrophysics Data System (ADS)
Xiang, Yang
2011-06-01
We give an analytic quantitative relation between Hardy's non-locality and Bell operator. We find that Hardy's non-locality is a sufficient condition for the violation of Bell inequality, the upper bound of Hardy's non-locality allowed by information causality just corresponds to Tsirelson bound of Bell inequality and the upper bound of Hardy's non-locality allowed by the principle of no-signaling just corresponds to the algebraic maximum of Bell operator. Then we study the Cabello's argument of Hardy's non-locality (a generalization of Hardy's argument) and find a similar relation between it and violation of Bell inequality. Finally, we give a simple derivation of the bound of Hardy's non-locality under the constraint of information causality with the aid of the above derived relation between Hardy's non-locality and Bell operator.
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.
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
INEQUITY IN THE FACE OF DEATH.
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. Copyright © 2014 John Wiley & Sons, Ltd.
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.
On measuring inequalities in health.
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
[Inequalities in cervical screening practices].
Döbrőssy, Lajos; Kovács, Attila; Budai, András
2015-06-14
Theoretically, the cytology-based cervical screening is capable of early detection of precancerous epithelial lesions of cervix uteri and its cancer, and of early referral to treatment. In this way, screening can inmprove the quality of life of the patients and reduce mortality from the target disease. Unfortunately, this often remains unexploited, because there might be inequalities on both "supply" and "demand" side of screening. In addition to the geopolitical situation of a country, inequalities might result from differences in the health care systems, and heavy access to the screening services. On the other hand, the socioeconomic status, the health-conciousness of the target population, and their knowledge and information of the benefits and potential harms of screening examination might have a bearing on the acceptance or refusal of the offered screening. Efforts need to be made to increase the uptake of cervical screening programmes.
Relativistic entanglement and Bell's inequality
Ahn, Doyeol; Moon, Young Hoon; Lee, Hyuk-jae; Hwang, Sung Woo
2003-01-01
In this paper, the Lorentz transformation of entangled Bell states seen by a moving observer is studied. The calculated Bell observable for four joint measurements turns out to give a universal value,
Nussinov, S.
1983-12-05
It is suggested that the inequality m/sub B/>(3/2)m/sub M/ is a rigorous result in quantum chromodynamics. The analog for a (q/sub 1/. . .q/sub N/) baryon in SU(N) is m/sub B/>((1/2)N)m/sub M/. The inequality is proved for weak coupling and a version of the strong-coupling expansion where a separation H/sub q//sub 1/q/sub 2/q/sub 3/ = H/sub 12/+H/sub 23/+H/sub 31/ of the problem can be achieved. Implications for quantum chromodynamics and composite models are briefly discussed.
[Social inequalities in maternal health].
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.
Optimal filter design subject to output delobe constraints
NASA Technical Reports Server (NTRS)
Fortmann, T. E.; Athans, M.
1972-01-01
The design of filters for detection and estimation in radar and communications systems is considered, with inequality constraints on the maximum output sidelobe levels. A constrained optimization problem in Hilbert space is formulated, incorporating the sidelobe constraints via a partial ordering of continuous functions. Generalized versions (in Hilbert space) of the Kuhn-Tucker and Duality Theorems allow the reduction of this problem to an unconstrained one in the dual space of regular Borel measures. A convergent algorithm is presented for computational solution of the dual problem.
Inequalities of Income and Inequalities of Longevity: A Cross-Country Study
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
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.
[Social inequality in medical rehabilitation].
Deck, R
2008-10-01
The association of social inequality and health is well known and well documented. Numerous studies have shown that a lower socio-economic status is associated with higher morbidity and mortality. This association is caused by various circumstances such as unfavourable work and living conditions, unhealthy life styles and risk factors and, last but not least, the access to medical care depending on socio-economic status. These aspects are correlated in various ways, at any rate they cause a higher prevalence of diseases and lower quality of life in persons with lower socio-economic status. The present article discusses the association between social inequality and medical rehabilitation, a problem which is rarely investigated in present research on social inequality and health. In our study, 911 rehabilitation patients were included. Analyses of socio-economic differences with respect to rehabilitation care address the following questions: are there differences in access to medical rehabilitation, in rehabilitation care, with respect to success of rehabilitation and satisfaction with rehabilitation? To assign patients to a social class - lower, middle and upper class - we constructed an indicator of social status based on education, occupation and income level. Our findings in a sample of rehabilitation patients are in line with the results of existing research on social inequality and health. Patients from the lower social class enter the rehabilitation care system with a poorer health state and leave it with less favourable results than patients with higher social status. However, with regard to the effect of rehabilitation care, middle class patients benefit least. It can be speculated that systematic information of patients about the aims of the rehabilitation programme and specific after care focusing on relevant aspects of daily living may reduce the disadvantages of lower class patients.
Kiadaliri, Aliasghar A; Asadi-Lari, Mohsen; Kalantari, Naser; Jafari, Mehdi; Vaez Mahdavi, Mohammad Reza; Faghihzadeh, Soghrat
2016-09-01
The prevalence of obesity is increasing in Iran. Previous studies showed mixed results in relation to association between socioeconomic status and obesity in the country. The current study aimed to examine educational inequalities among adults in Tehran in 2011. Data on 90,435 persons 18 years and older from Urban Health Equity Assessment and Response Tool (Urban HEART-2) were analyzed. The Slope Index of Inequality (SII) and the Relative Index of Inequality (RII) were used for assessing educational inequalities in obesity. These measures were quantified using generalized linear models for the binomial family adjusted for sex and age. Subgroup analysis was conducted across sex, age groups and the 22 districts of Tehran. Both SII and RII showed substantial educational inequalities in obesity in favour of more educated adults [RII and SII (95% CI were equal to 2.91 (2.71-3.11) and 0.12 (0.12-0.13)), respectively]. These educational inequalities were persistent even after adjusting for employment, marital status and smoking. Subgroup analysis revealed that educational inequalities were more profound among women. While among men educational inequalities were generally increasing with age, an inverse trend was observed among women. Educational inequalities were observed within all 22 districts of Tehran and generally there were no statistically significant differences between districts. An inverse association between education and obesity was observed in the current study. To decrease educational inequalities in Tehran, priority should be given to younger women and older men. Further analyses are needed to explain these inequalities. Copyright © 2015 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
Income inequality in the developing world.
Ravallion, Martin
2014-05-23
Should income inequality be of concern in developing countries? New data reveal less income inequality in the developing world than 30 years ago. However, this is due to falling inequality between countries. Average inequality within developing countries has been slowly rising, though staying fairly flat since 2000. As a rule, higher rates of growth in average incomes have not put upward pressure on inequality within countries. Growth has generally helped reduce the incidence of absolute poverty, but less so in more unequal countries. High inequality also threatens to stall future progress against poverty by attenuating growth prospects. Perceptions of rising absolute gaps in living standards between the rich and the poor in growing economies are also consistent with the evidence. Copyright © 2014, American Association for the Advancement of Science.
A toy Penrose inequality and its proof
NASA Astrophysics Data System (ADS)
Bengtsson, Ingemar; Jakobsson, Emma
2016-12-01
We formulate and prove a toy version of the Penrose inequality. The formulation mimics the original Penrose inequality in which the scenario is the following: a shell of null dust collapses in Minkowski space and a marginally trapped surface forms on it. Through a series of arguments relying on established assumptions, an inequality relating the area of this surface to the total energy of the shell is formulated. Then a further reformulation turns the inequality into a statement relating the area and the outer null expansion of a class of surfaces in Minkowski space itself. The inequality has been proven to hold true in many special cases, but there is no proof in general. In the toy version here presented, an analogous inequality in (2 + 1)-dimensional anti-de Sitter space turns out to hold true.
Inequalities in health and social policy.
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.
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.
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.
Social Influences on Inequity Aversion in Children
McAuliffe, Katherine; Blake, Peter R.; Kim, Grace; Wrangham, Richard W.; Warneken, Felix
2013-01-01
Adults and children are willing to sacrifice personal gain to avoid both disadvantageous and advantageous inequity. These two forms of inequity aversion follow different developmental trajectories, with disadvantageous inequity aversion emerging around 4 years and advantageous inequity aversion emerging around 8 years. Although inequity aversion is assumed to be specific to situations where resources are distributed among individuals, the role of social context has not been tested in children. Here, we investigated the influence of two aspects of social context on inequity aversion in 4- to 9-year-old children: (1) the role of the experimenter distributing rewards and (2) the presence of a peer with whom rewards could be shared. Experiment 1 showed that children rejected inequity at the same rate, regardless of whether the experimenter had control over reward allocations. This indicates that children’s decisions are based upon reward allocations between themselves and a peer and are not attempts to elicit more favorable distributions from the experimenter. Experiment 2 compared rejections of unequal reward allocations in children interacting with or without a peer partner. When faced with a disadvantageous distribution, children frequently rejected a smaller reward when a larger reward was visible, even if no partner would obtain the larger reward. This suggests that nonsocial factors partly explain disadvantageous inequity rejections. However, rejections of disadvantageous distributions were higher when the larger amount would go to a peer, indicating that social context enhances disadvantageous inequity aversion. By contrast, children rejected advantageous distributions almost exclusively in the social context. Therefore, advantageous inequity aversion appears to be genuinely social, highlighting its potential relevance for the development of fairness concerns. By comparing social and nonsocial factors, this study provides a detailed picture of the expression
Generalized Input-Output Inequality Systems
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.
NASA Astrophysics Data System (ADS)
Grégoire, G.
2014-12-01
This chapter deals with the multiple linear regression. That is we investigate the situation where the mean of a variable depends linearly on a set of covariables. The noise is supposed to be gaussian. We develop the least squared method to get the parameter estimators and estimates of their precisions. This leads to design confidence intervals, prediction intervals, global tests, individual tests and more generally tests of submodels defined by linear constraints. Methods for model's choice and variables selection, measures of the quality of the fit, residuals study, diagnostic methods are presented. Finally identification of departures from the model's assumptions and the way to deal with these problems are addressed. A real data set is used to illustrate the methodology with software R. Note that this chapter is intended to serve as a guide for other regression methods, like logistic regression or AFT models and Cox regression.
ERIC Educational Resources Information Center
Larraz, Beatriz
2015-01-01
The aim of this article is to propose a new breakdown of the Gini inequality ratio into three components ("within-group" inequality, "between-group" inequality, and intensity of "transvariation" between groups to the total inequality index). The between-group inequality concept computes all the differences in salaries…
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.
A Hierarchical Linear Model for Estimating Gender-Based Earnings Differentials.
ERIC Educational Resources Information Center
Haberfield, Yitchak; Semyonov, Moshe; Addi, Audrey
1998-01-01
Estimates of gender earnings inequality in data from 116,431 Jewish workers were compared using a hierarchical linear model (HLM) and ordinary least squares model. The HLM allows estimation of the extent to which earnings inequality depends on occupational characteristics. (SK)
On Noisy Extensions of Nonholonomic Constraints
NASA Astrophysics Data System (ADS)
Gay-Balmaz, François; Putkaradze, Vakhtang
2016-12-01
We propose several stochastic extensions of nonholonomic constraints for mechanical systems and study the effects on the dynamics and on the conservation laws. Our approach relies on a stochastic extension of the Lagrange-d'Alembert framework. The mechanical system we focus on is the example of a Routh sphere, i.e., a rolling unbalanced ball on the plane. We interpret the noise in the constraint as either a stochastic motion of the plane, random slip or roughness of the surface. Without the noise, this system possesses three integrals of motion: energy, Jellet and Routh. Depending on the nature of noise in the constraint, we show that either energy, or Jellet, or both integrals can be conserved, with probability 1. We also present some exact solutions for particular types of motion in terms of stochastic integrals. Next, for an arbitrary nonholonomic system, we consider two different ways of including stochasticity in the constraints. We show that when the noise preserves the linearity of the constraints, then energy is preserved. For other types of noise in the constraint, e.g., in the case of an affine noise, the energy is not conserved. We study in detail a class of Lagrangian mechanical systems on semidirect products of Lie groups, with "rolling ball type" constraints. We conclude with numerical simulations illustrating our theories, and some pedagogical examples of noise in constraints for other nonholonomic systems popular in the literature, such as the nonholonomic particle, the rolling disk and the Chaplygin sleigh.
NASA Astrophysics Data System (ADS)
Scutari, Gesualdo; Palomar, Daniel P.; Barbarossa, Sergio
In this two-part paper, we address the problem of finding the optimal precoding/multiplexing scheme for a set of non-cooperative links sharing the same physical resources, e.g., time and bandwidth. We consider two alternative optimization problems: P.1) the maximization of mutual information on each link, given constraints on the transmit power and spectral mask; and P.2) the maximization of the transmission rate on each link, using finite order constellations, under the same constraints as in P.1, plus a constraint on the maximum average error probability on each link. Aiming at finding decentralized strategies, we adopted as optimality criterion the achievement of a Nash equilibrium and thus we formulated both problems P.1 and P.2 as strategic noncooperative (matrix-valued) games. In Part I of this two-part paper, after deriving the optimal structure of the linear transceivers for both games, we provided a unified set of sufficient conditions that guarantee the uniqueness of the Nash equilibrium. In this Part II, we focus on the achievement of the equilibrium and propose alternative distributed iterative algorithms that solve both games. Specifically, the new proposed algorithms are the following: 1) the sequential and simultaneous iterative waterfilling based algorithms, incorporating spectral mask constraints; 2) the sequential and simultaneous gradient projection based algorithms, establishing an interesting link with variational inequality problems. Our main contribution is to provide sufficient conditions for the global convergence of all the proposed algorithms which, although derived under stronger constraints, incorporating for example spectral mask constraints, have a broader validity than the convergence conditions known in the current literature for the sequential iterative waterfilling algorithm.
Income inequality, poverty and crime across nations.
Pare, Paul-Philippe; Felson, Richard
2014-09-01
We examine the relationship between income inequality, poverty, and different types of crime. Our results are consistent with recent research in showing that inequality is unrelated to homicide rates when poverty is controlled. In our multi-level analyses of the International Crime Victimization Survey we find that inequality is unrelated to assault, robbery, burglary, and theft when poverty is controlled. We argue that there are also theoretical reasons to doubt that the level of income inequality of a country affects the likelihood of criminal behaviour.
Income and health inequality across Canadian provinces.
Safaei, Jalil
2007-09-01
This paper uses the aggregate data from the Public Use Microdata Files (PUMF) of Canadian National Population Health Survey to estimate income related health inequalities across the ten Canadian provinces. The unique features of the PUMF allow for a meaningful cross-provincial comparison of health indices and their measured inequalities. It concludes that health inequalities favouring the higher income people do exist in all provinces when health status is either self assessed or measured by the health utility index. Moreover, it finds considerable variations in measured health inequalities across the provinces with consistent rankings for certain provinces.
Bell-type inequalities for nonlocal resources
NASA Astrophysics Data System (ADS)
Brunner, Nicolas; Scarani, Valerio; Gisin, Nicolas
2006-11-01
We present bipartite Bell-type inequalities which allow the two partners to use some nonlocal resource. Such inequalities can only be violated if the parties use a resource which is more nonlocal than the one permitted by the inequality. We introduce a family of N-input nonlocal machines, which are generalizations of the well-known PR (Popescu-Rohrlich) box. Then we construct Bell-type inequalities that cannot be violated by strategies that use one of these new machines. Finally we discuss implications for the simulation of quantum states.
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.
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.
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.
Adaptivity with near-orthogonality constraint for high compression rates in lifting scheme framework
NASA Astrophysics Data System (ADS)
Sliwa, Tadeusz; Voisin, Yvon; Diou, Alain
2004-01-01
Since few years, Lifting Scheme has proven its utility in compression field. It permits to easily create fast, reversible, separable or no, not necessarily linear, multiresolution analysis for sound, image, video or even 3D graphics. An interesting feature of lifting scheme is the ability to build adaptive transforms for compression, more easily than with other decompositions. Many works have already be done in this subject, especially in lossless or near-lossless compression framework : better compression than with usually used methods can be obtained. However, most of the techniques used in adaptive near-lossless compression can not be extended to higher lossy compression rates, even in the simplest cases. Indeed, this is due to the quantization error introduced before coding, which has not controlled propagation through inverse transform. Authors have put their interest to the classical Lifting Scheme, with linear convolution filters, but they studied criterions to maintain a high level of adaptivity and a good error propagation through inverse transform. This article aims to present relatively simple criterion to obtain filters able to build image and video compression with high compression rate, tested here with the Spiht coder. For this, upgrade and predict filters are simultaneously adapted thanks to a constrained least-square method. The constraint consists in a near-orthogonality inequality, letting sufficiently high level of adaptivity. Some compression results are given, illustrating relevance of this method, even with short filters.
Walasek, Lukasz; Brown, Gordon D A
2016-01-01
Is there a positive association between a nation's income inequality and concerns with status competition within that nation? Here we use Google Correlate and Google Trends to examine frequency of internet search terms and find that people in countries in which income inequality is high search relatively more frequently for positional brand names such as Prada, Louis Vuitton, or Chanel. This tendency is stronger among well-developed countries. We find no evidence that income alone is associated with searches for positional goods. We also present evidence that the concern with positional goods does not reflect non-linear effects of income on consumer spending, either across nations or (extending previous findings that people who live in unequal US States search more for positional goods) within the USA. It is concluded that income inequality is associated with greater concerns with positional goods, and that this concern is reflected in internet searching behaviour.
NASA Astrophysics Data System (ADS)
Morel, Danielle; Levy, William B.
2006-03-01
Information processing in the brain is metabolically expensive and energy usage by the different components of the nervous system is not well understood. In a continuing effort to explore the costs and constraints of information processing at the single neuron level, dendritic processes are being studied. More specifically, the role of various ion channel conductances is explored in terms of integrating dendritic excitatory synaptic input. Biophysical simulations of dendritic behavior show that the complexity of voltage-dependent, non-linear dendritic conductances can produce simplicity in the form of linear synaptic integration. Over increasing levels of synaptic activity, it is shown that two types of voltage-dependent conductances produce linearization over a limited range. This range is determined by the parameters defining the ion channel and the 'passive' properties of the dendrite. A persistent sodium and a transient A-type potassium channel were considered at steady-state transmembrane potentials in the vicinity of and hyperpolarized to the threshold for action potential initiation. The persistent sodium is seen to amplify and linearize the synaptic input over a short range of low synaptic activity. In contrast, the A-type potassium channel has a broader linearization range but tends to operate at higher levels of synaptic bombardment. Given equivalent 'passive' dendritic properties, the persistent sodium is found to be less costly than the A-type potassium in linearizing synaptic input.
[Income inequality, corruption, and life expectancy at birth in Mexico].
Idrovo, Alvaro Javier
2005-01-01
To ascertain if the effect of income inequality on life expectancy at birth in Mexico is mediated by corruption, used as a proxy of social capital. An ecological study was carried out with the 32 Mexican federative entities. Global and by sex correlations between life expectancy at birth were estimated by federative entity with the Gini coefficient, the Corruption and Good Government Index, the percentage of Catholics, and the percentage of the population speaking indigenous language. Robust linear regressions, with and without instrumental variables, were used to explore if corruption acts as intermediate variable in the studied relationship. Negative correlations with Spearman's rho near to -0.60 (p < 0.05) and greater than -0.66 (p < 0.05) between life expectancy at birth, the Gini coefficient and the population speaking indigenous language, respectively, were observed. Moreover, the Corruption and Good Government Index correlated with men's life expectancy at birth with Spearman's rho -0.3592 (p < 0.05). Regressions with instruments were more consistent than conventional ones and they show a strong negative effect (p < 0.05) of income inequality on life expectancy at birth. This effect was greater among men. The findings suggest a negative effect of income inequality on life expectancy at birth in Mexico, mediated by corruption levels and other related cultural factors.
Conditions for Stabilizability of Linear Switched Systems
NASA Astrophysics Data System (ADS)
Minh, Vu Trieu
2011-06-01
This paper investigates some conditions that can provide stabilizability for linear switched systems with polytopic uncertainties via their closed loop linear quadratic state feedback regulator. The closed loop switched systems can stabilize unstable open loop systems or stable open loop systems but in which there is no solution for a common Lyapunov matrix. For continuous time switched linear systems, we show that if there exists solution in an associated Riccati equation for the closed loop systems sharing one common Lyapunov matrix, the switched linear systems are stable. For the discrete time switched systems, we derive a Linear Matrix Inequality (LMI) to calculate a common Lyapunov matrix and solution for the stable closed loop feedback systems. These closed loop linear quadratic state feedback regulators guarantee the global asymptotical stability for any switched linear systems with any switching signal sequence.
Bell inequality tests of four-photon six-qubit graph states
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.
Measuring inequality: tools and an illustration
Williams, Ruth FG; Doessel, DP
2006-01-01
Background This paper examines an aspect of the problem of measuring inequality in health services. The measures that are commonly applied can be misleading because such measures obscure the difficulty in obtaining a complete ranking of distributions. The nature of the social welfare function underlying these measures is important. The overall object is to demonstrate that varying implications for the welfare of society result from inequality measures. Method Various tools for measuring a distribution are applied to some illustrative data on four distributions about mental health services. Although these data refer to this one aspect of health, the exercise is of broader relevance than mental health. The summary measures of dispersion conventionally used in empirical work are applied to the data here, such as the standard deviation, the coefficient of variation, the relative mean deviation and the Gini coefficient. Other, less commonly used measures also are applied, such as Theil's Index of Entropy, Atkinson's Measure (using two differing assumptions about the inequality aversion parameter). Lorenz curves are also drawn for these distributions. Results Distributions are shown to have differing rankings (in terms of which is more equal than another), depending on which measure is applied. Conclusion The scope and content of the literature from the past decade about health inequalities and inequities suggest that the economic literature from the past 100 years about inequality and inequity may have been overlooked, generally speaking, in the health inequalities and inequity literature. An understanding of economic theory and economic method, partly introduced in this article, is helpful in analysing health inequality and inequity. PMID:16716217
Correlations between Income Inequality and Antimicrobial Resistance
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
Inequality, deprivation and alcohol use.
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.
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.
Addressing inequities in healthy eating.
Friel, Sharon; Hattersley, Libby; Ford, Laura; O'Rourke, Kerryn
2015-09-01
What, when, where and how much people eat is influenced by a complex mix of factors at societal, community and individual levels. These influences operate both directly through the food system and indirectly through political, economic, social and cultural pathways that cause social stratification and influence the quality of conditions in which people live their lives. These factors are the social determinants of inequities in healthy eating. This paper provides an overview of the current evidence base for addressing these determinants and for the promotion of equity in healthy eating. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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.
Bayesian Estimation of Circumplex Models Subject to Prior Theory Constraints and Scale-Usage Bias
ERIC Educational Resources Information Center
Lenk, Peter; Wedel, Michel; Bockenholt, Ulf
2006-01-01
This paper presents a hierarchical Bayes circumplex model for ordinal ratings data. The circumplex model was proposed to represent the circular ordering of items in psychological testing by imposing inequalities on the correlations of the items. We provide a specification of the circumplex, propose identifying constraints and conjugate priors for…
Bayesian Estimation of Circumplex Models Subject to Prior Theory Constraints and Scale-Usage Bias
ERIC Educational Resources Information Center
Lenk, Peter; Wedel, Michel; Bockenholt, Ulf
2006-01-01
This paper presents a hierarchical Bayes circumplex model for ordinal ratings data. The circumplex model was proposed to represent the circular ordering of items in psychological testing by imposing inequalities on the correlations of the items. We provide a specification of the circumplex, propose identifying constraints and conjugate priors for…
A variational solution to the transport equation subject to an affine constraint.
Pousin, Jerome G.; Najm, Habib N.; Picq, Martine; Pebay, Philippe Pierre
2004-02-01
We establish an existence and uniqueness theorem for the transport equation subject to an inequality affine constraint, viewed as a constrained optimization problem. Then we derive a Space-Time Integrated Least Squares (STILS) scheme for its numerical approximation. Furthermore, we discuss some L{sup 2}-projection strategies and with numerical examples we show that there are not relevant for that problem.
Confronting Gender Inequality in a Business School
ERIC Educational Resources Information Center
Reilly, Amanda; Jones, Deborah; Rey Vasquez, Carla; Krisjanous, Jayne
2016-01-01
This study, set in a New Zealand Business School, takes an integrative view of the university as an "inequality regime" Acker, J. (2006b). Inequality regimes: Gender, class and race in organizations. "Gender and Society," 20(4), 441-464 including all types of women staff: academic women in permanent positions, academics on…
Educational Inequality in English Primary Education
ERIC Educational Resources Information Center
Richards, Colin
2008-01-01
This paper summarises some English research findings related to educational inequality, particularly in inner urban schools. It documents how differences related to relative poverty are reflected in patterns of educational attainment as revealed by national tests results. It considers and evaluates how the issue of educational inequality in…
Generalized geometrically convex functions and inequalities.
Noor, Muhammad Aslam; Noor, Khalida Inayat; Safdar, Farhat
2017-01-01
In this paper, we introduce and study a new class of generalized functions, called generalized geometrically convex functions. We establish several basic inequalities related to generalized geometrically convex functions. We also derive several new inequalities of the Hermite-Hadamard type for generalized geometrically convex functions. Several special cases are discussed, which can be deduced from our main results.
Regional Educational Inequality and Political Instability.
ERIC Educational Resources Information Center
Monchar, Philip Harris
1981-01-01
From a study of 46 nations over the period 1957 to 1973, it is argued that regional educational inequality indicates the presence of other regional social, political, and economic inequalities, and it is all of these factors together that generate feelings of relative deprivation and the pursuant political instability. (Author/SJL)
Human Differences and Inequalities: Causes and Effects
ERIC Educational Resources Information Center
Schoenfeldt, Lyle F.
1974-01-01
The portions of Inequality: A Reassessment of the Effect of Family and Schooling in America (Jencks, et al 1972) concerned with inequality in cognitive skills and estimating the heritability of IQ scores are reviewed. For related articles see TM 501 196-200. (MLP)
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…
Children Rectify Inequalities for Disadvantaged Groups
ERIC Educational Resources Information Center
Elenbaas, Laura; Killen, Melanie
2016-01-01
Children's decisions regarding the allocation of societal resources in the context of preexisting inequalities were investigated. African American and European American children ages 5 to 6 years (n = 91) and 10 to 11 years (n = 94) judged the acceptability of a medical resource inequality on the basis of race, allocated medical supplies,…
Confronting Gender Inequality in a Business School
ERIC Educational Resources Information Center
Reilly, Amanda; Jones, Deborah; Rey Vasquez, Carla; Krisjanous, Jayne
2016-01-01
This study, set in a New Zealand Business School, takes an integrative view of the university as an "inequality regime" Acker, J. (2006b). Inequality regimes: Gender, class and race in organizations. "Gender and Society," 20(4), 441-464 including all types of women staff: academic women in permanent positions, academics on…
Racial Inequity in Special Education Undefined
ERIC Educational Resources Information Center
Losen, Daniel J., Ed.; Orfield, Gary, Ed.
2002-01-01
An illuminating account of a widespread problem that has received little attention, "Racial Inequity in Education" sets the stage for a more fruitful discussion about special education and racial justice. An illuminating account of a widespread problem that has received little attention, "Racial Inequity in Education" sets the…
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…
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…
One-dimensional differential Hardy inequality.
Kalybay, Aigerim
2017-01-01
We establish necessary and sufficient conditions for the one-dimensional differential Hardy inequality to hold, including the overdetermined case. The solution is given in terms different from those of the known results. Moreover, the least constant for this inequality is estimated.
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…
Children Rectify Inequalities for Disadvantaged Groups
ERIC Educational Resources Information Center
Elenbaas, Laura; Killen, Melanie
2016-01-01
Children's decisions regarding the allocation of societal resources in the context of preexisting inequalities were investigated. African American and European American children ages 5 to 6 years (n = 91) and 10 to 11 years (n = 94) judged the acceptability of a medical resource inequality on the basis of race, allocated medical supplies,…
School Inequality and the Welfare State.
ERIC Educational Resources Information Center
Owen, John D.
This book begins with an examination of school inequality in the United States. The discussion focuses successively on the issues of: the paradox of unequal schools in a welfare state, the distribution of educational resources in American cities: some new empirical evidence, inequalities in the allocation of educational resources among cities and…
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…
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…
Inequality of Paediatric Workforce Distribution in China
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
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…
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…
Regional Educational Inequality and Political Instability.
ERIC Educational Resources Information Center
Monchar, Philip Harris
1981-01-01
From a study of 46 nations over the period 1957 to 1973, it is argued that regional educational inequality indicates the presence of other regional social, political, and economic inequalities, and it is all of these factors together that generate feelings of relative deprivation and the pursuant political instability. (Author/SJL)
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…
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…
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…
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…
Existence results for quasilinear parabolic hemivariational inequalities
NASA Astrophysics Data System (ADS)
Liu, Zhenhai
This paper is devoted to the periodic problem for quasilinear parabolic hemivariational inequalities at resonance as well as at nonresonance. By use of the theory of multi-valued pseudomonotone operators, the notion of generalized gradient of Clarke and the property of the first eigenfunction, we build a Landesman-Lazer theory in the nonsmooth framework of quasilinear parabolic hemivariational inequalities.
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…
Educational Inequality in English Primary Education
ERIC Educational Resources Information Center
Richards, Colin
2008-01-01
This paper summarises some English research findings related to educational inequality, particularly in inner urban schools. It documents how differences related to relative poverty are reflected in patterns of educational attainment as revealed by national tests results. It considers and evaluates how the issue of educational inequality in…
Enduring Legacy? Charles Tilly and Durable Inequality.
Voss, Kim
2010-12-01
This article assesses Charles Tilly's Durable Inequality and traces its influence. In writing Durable Inequality, Tilly sought to shift the research agenda of stratification scholars. But the book's initial impact was disappointing. In recent years, however, its influence has grown, suggesting a more enduring legacy.
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…
Linear matrix inequalities for analysis and control of linear vector second-order systems
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.
Boundary Korn Inequality and Neumann Problems in Homogenization of Systems of Elasticity
NASA Astrophysics Data System (ADS)
Geng, Jun; Shen, Zhongwei; Song, Liang
2017-06-01
This paper is concerned with a family of elliptic systems of linear elasticity with rapidly oscillating periodic coefficients, arising in the theory of homogenization. We establish uniform optimal regularity estimates for solutions of Neumann problems in a bounded Lipschitz domain with L 2 boundary data. The proof relies on a boundary Korn inequality for solutions of systems of linear elasticity and uses a large-scale Rellich estimate obtained in Shen (Anal PDE, arXiv:1505.00694v2).
Boundary Korn Inequality and Neumann Problems in Homogenization of Systems of Elasticity
NASA Astrophysics Data System (ADS)
Geng, Jun; Shen, Zhongwei; Song, Liang
2017-02-01
This paper is concerned with a family of elliptic systems of linear elasticity with rapidly oscillating periodic coefficients, arising in the theory of homogenization. We establish uniform optimal regularity estimates for solutions of Neumann problems in a bounded Lipschitz domain with L 2 boundary data. The proof relies on a boundary Korn inequality for solutions of systems of linear elasticity and uses a large-scale Rellich estimate obtained in Shen (Anal PDE, arXiv:1505.00694v2).
Constraint reasoning in deep biomedical models.
Cruz, Jorge; Barahona, Pedro
2005-05-01
Deep biomedical models are often expressed by means of differential equations. Despite their expressive power, they are difficult to reason about and make decisions, given their non-linearity and the important effects that the uncertainty on data may cause. The objective of this work is to propose a constraint reasoning framework to support safe decisions based on deep biomedical models. The methods used in our approach include the generic constraint propagation techniques for reducing the bounds of uncertainty of the numerical variables complemented with new constraint reasoning techniques that we developed to handle differential equations. The results of our approach are illustrated in biomedical models for the diagnosis of diabetes, tuning of drug design and epidemiology where it was a valuable decision-supporting tool notwithstanding the uncertainty on data. The main conclusion that follows from the results is that, in biomedical decision support, constraint reasoning may be a worthwhile alternative to traditional simulation methods, especially when safe decisions are required.
Health Inequalities: Trends, Progress, and Policy
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
Regional inequality in China's health care expenditures.
Chou, Win Lin; Wang, Zijun
2009-07-01
This paper has two parts. The first part examines the regional health expenditure inequality in China by testing two hypotheses on health expenditure convergence. Cross-section regressions and cluster analysis are used to study the health expenditure convergence and to identify convergence clusters. We find no single nationwide convergence, only convergence by cluster. In the second part of the paper, we investigate the long-run relationship between health expenditure inequality, income inequality, and provincial government budget deficits (BD) by using new panel co-integration tests with health expenditure data in China's urban and rural areas. We find that the income inequality and real provincial government BD are useful in explaining the disparity in health expenditure prevailing between urban and rural areas. In order to reduce health-spending inequality, one long-run policy suggestion from our findings is for the government to implement more rapid economic development and stronger financing schemes in poorer rural areas.
Exposure to inequality affects support for redistribution.
Sands, Melissa L
2017-01-24
The distribution of wealth in the United States and countries around the world is highly skewed. How does visible economic inequality affect well-off individuals' support for redistribution? Using a placebo-controlled field experiment, I randomize the presence of poverty-stricken people in public spaces frequented by the affluent. Passersby were asked to sign a petition calling for greater redistribution through a "millionaire's tax." Results from 2,591 solicitations show that in a real-world-setting exposure to inequality decreases affluent individuals' willingness to redistribute. The finding that exposure to inequality begets inequality has fundamental implications for policymakers and informs our understanding of the effects of poverty, inequality, and economic segregation. Confederate race and socioeconomic status, both of which were randomized, are shown to interact such that treatment effects vary according to the race, as well as gender, of the subject.
Bell Inequalities Tailored to Maximally Entangled States
NASA Astrophysics Data System (ADS)
Salavrakos, Alexia; Augusiak, Remigiusz; Tura, Jordi; Wittek, Peter; Acín, Antonio; Pironio, Stefano
2017-07-01
Bell inequalities have traditionally been used to demonstrate that quantum theory is nonlocal, in the sense that there exist correlations generated from composite quantum states that cannot be explained by means of local hidden variables. With the advent of device-independent quantum information protocols, Bell inequalities have gained an additional role as certificates of relevant quantum properties. In this work, we consider the problem of designing Bell inequalities that are tailored to detect maximally entangled states. We introduce a class of Bell inequalities valid for an arbitrary number of measurements and results, derive analytically their tight classical, nonsignaling, and quantum bounds and prove that the latter is attained by maximally entangled states. Our inequalities can therefore find an application in device-independent protocols requiring maximally entangled states.
Exposure to inequality affects support for redistribution
Sands, Melissa L.
2017-01-01
The distribution of wealth in the United States and countries around the world is highly skewed. How does visible economic inequality affect well-off individuals’ support for redistribution? Using a placebo-controlled field experiment, I randomize the presence of poverty-stricken people in public spaces frequented by the affluent. Passersby were asked to sign a petition calling for greater redistribution through a “millionaire’s tax.” Results from 2,591 solicitations show that in a real-world-setting exposure to inequality decreases affluent individuals’ willingness to redistribute. The finding that exposure to inequality begets inequality has fundamental implications for policymakers and informs our understanding of the effects of poverty, inequality, and economic segregation. Confederate race and socioeconomic status, both of which were randomized, are shown to interact such that treatment effects vary according to the race, as well as gender, of the subject. PMID:28069960
Wealth inequality: The physics basis
NASA Astrophysics Data System (ADS)
Bejan, A.; Errera, M. R.
2017-03-01
"Inequality" is a common observation about us, as members of society. In this article, we unify physics with economics by showing that the distribution of wealth is related proportionally to the movement of all the streams of a live society. The hierarchical distribution of wealth on the earth happens naturally. Hierarchy is unavoidable, with staying power, and difficult to efface. We illustrate this with two architectures, river basins and the movement of freight. The physical flow architecture that emerges is hierarchical on the surface of the earth and in everything that flows inside the live human bodies, the movement of humans and their belongings, and the engines that drive the movement. The nonuniform distribution of wealth becomes more accentuated as the economy becomes more developed, i.e., as its flow architecture becomes more complex for the purpose of covering smaller and smaller interstices of the overall (fixed) territory. It takes a relatively modest complexity for the nonuniformity in the distribution of wealth to be evident. This theory also predicts the Lorenz-type distribution of income inequality, which was adopted empirically for a century.
Inequalities in diet and nutrition.
Tiffin, Richard; Salois, Matthew
2012-02-01
The inequality of nutrition and obesity re-focuses concern on who in society is consuming the worst diet. Identification of individuals with the worst of dietary habits permits for targeting interventions to assuage obesity among the population segment where it is most prevalent. We argue that the use of fiscal interventions does not appropriately take into account the economic, social and health circumstances of the intended beneficiaries of the policy. This paper reviews the influence of socio-demographic factors on nutrition and health status and considers the impacts of nutrition policy across the population drawing on methodologies from both public health and welfare economics. The effects of a fat tax on diet are found to be small and while other studies show that fat taxes saves lives, we show that average levels of disease risk do not change much: those consuming particularly bad diets continue to do so. Our results also suggest that the regressivity of the policy increases as the tax becomes focused on products with high saturated fat contents. A fiscally neutral policy that combines the fat tax with a subsidy on fruit and vegetables is actually more regressive because consumption of these foods tends to be concentrated in socially undeserving households. We argue that when inequality is of concern, population-based measures must reflect this and approaches that target vulnerable populations which have a shared propensity to adopt unhealthy behaviours are appropriate.
Constraint Theory and Roken Bond Bending Constraints in Oxide Glasses
NASA Astrophysics Data System (ADS)
Zhang, Min
can understand the rigidity percolation threshold shift from x = 0.20 to x = 0.23, if one assumes a fraction of 20% chalcogen atoms have their bond angle constraints broken. A simple interpretation is that these chalcogen atoms (with broken bond bending constraints) represent short floppy chain-segments connecting the more rigid tetrahedral Ge(Se_{1/2} )_4 units. Thus the concept of broken bond bending constraints plays an important role in promoting glass forming tendency of materials. The extended constraint theory has also found application in aspect of mechanical property of hydrogenated diamond like carbon, silicon carbide and silicon thin films. We have established for the first time a linear relationship between measured hardness and hardness index, a geometric parameter derived from constraint theory. The slopes of such linear functions for different type materials are determined by chemical effect that reflect bonding type and interaction strength among atoms.
Hard Constraints in Optimization Under Uncertainty
NASA Technical Reports Server (NTRS)
Crespo, Luis G.; Giesy, Daniel P.; Kenny, Sean P.
2008-01-01
This paper proposes a methodology for the analysis and design of systems subject to parametric uncertainty where design requirements are specified via hard inequality constraints. Hard constraints are those that must be satisfied for all parameter realizations within a given uncertainty model. Uncertainty models given by norm-bounded perturbations from a nominal parameter value, i.e., hyper-spheres, and by sets of independently bounded uncertain variables, i.e., hyper-rectangles, are the focus of this paper. These models, which are also quite practical, allow for a rigorous mathematical treatment within the proposed framework. Hard constraint feasibility is determined by sizing the largest uncertainty set for which the design requirements are satisfied. Analytically verifiable assessments of robustness are attained by comparing this set with the actual uncertainty model. Strategies that enable the comparison of the robustness characteristics of competing design alternatives, the description and approximation of the robust design space, and the systematic search for designs with improved robustness are also proposed. Since the problem formulation is generic and the tools derived only require standard optimization algorithms for their implementation, this methodology is applicable to a broad range of engineering problems.
Deuterium nuclear fusion at room temperature: A pertinent inequality on barrier penetration
Rosen, G. )
1989-10-01
For a D{sub 2} molecule with linear vibrational energy {ital E}, it is shown that {lambda}({ital E}) in the WKB {ital d}--{ital d} fusion rate expression {Lambda}({ital E}){congruent}(5.7{times}10{sup 8} s{sup {minus}1})(exp{minus}{lambda}({ital E})) satisfies a useful scaling inequality. It follows from this inequality that {Lambda}({ital E}){approx gt}2.8{times}10{sup {minus}20} s{sup {minus}1} for a lattice-caged D{sub 2} with vibrational energy {ital E}=9.0 eV.
NASA Astrophysics Data System (ADS)
White, T. C.; Mutus, J. Y.; Dressel, J.; Kelly, J.; Barends, R.; Jeffrey, E.; Sank, D.; Megrant, A.; Campbell, B.; Chen, Yu; Chen, Z.; Chiaro, B.; Dunsworth, A.; Hoi, I.-C.; Neill, C.; O'Malley, P. J. J.; Roushan, P.; Vainsencher, A.; Wenner, J.; Korotkov, A. N.; Martinis, John M.
2016-02-01
Weak measurement has provided new insight into the nature of quantum measurement, by demonstrating the ability to extract average state information without fully projecting the system. For single-qubit measurements, this partial projection has been demonstrated with violations of the Leggett-Garg inequality. Here we investigate the effects of weak measurement on a maximally entangled Bell state through application of the Hybrid Bell-Leggett-Garg inequality (BLGI) on a linear chain of four transmon qubits. By correlating the results of weak ancilla measurements with subsequent projective readout, we achieve a violation of the BLGI with 27 s.d.s. of certainty.
A new interior point method for the variational inequality problem
Iusem, A.; Burachik, R.
1994-12-31
We present an algorithm for the variational inequality problem on convex sets with nonempty interior. The use of Bregman functions whose zone is the convex set allows for the generation of a sequence contained in the interior, without taking explicitly into account the constraints which define the convex set. We establish full convergence to a solution with minimal conditions upon the monotone operator F, weaker than strong monotonicity or Lipschitz continuity, for instance, and including cases where the solution needs not be unique. We apply our algorithm to several relevant classes of convex sets, including orthants, boxes, polyhedra and balls, for which Bregman functions are presented which give raise to explicit iteration formulae, up to the determination of two scalar stepsizes, which can be found through finite search procedures.
Teaching Australian Football in Physical Education: Constraints Theory in Practice
ERIC Educational Resources Information Center
Pill, Shane
2013-01-01
This article outlines a constraints-led process of exploring, modifying, experimenting, adapting, and developing game appreciation known as Game Sense (Australian Sports Commission, 1997; den Duyn, 1996, 1997) for the teaching of Australian football. The game acts as teacher in this constraints-led process. Rather than a linear system that…
Teaching Australian Football in Physical Education: Constraints Theory in Practice
ERIC Educational Resources Information Center
Pill, Shane
2013-01-01
This article outlines a constraints-led process of exploring, modifying, experimenting, adapting, and developing game appreciation known as Game Sense (Australian Sports Commission, 1997; den Duyn, 1996, 1997) for the teaching of Australian football. The game acts as teacher in this constraints-led process. Rather than a linear system that…
Impulsive synchronization of discrete-time chaotic systems under communication constraints
NASA Astrophysics Data System (ADS)
Gao, Yanbo; Zhang, Xiaomei; Lu, Guoping; Zheng, Yufan
2011-03-01
This paper investigates the problem of impulsive synchronization of discrete-time chaotic systems subject to limited communication capacity. Control laws with impulses are derived by using measurement feedback, where the effect of quantization errors is considered. Sufficient conditions for asymptotic stability of synchronization error systems are given in terms of linear matrix inequalities and algebraic inequalities. Some numerical simulations are given to demonstrate the effectiveness of the method.
Higher derivative theories with constraints: exorcising Ostrogradski's ghost
Chen, Tai-jun; Lim, Eugene A.; Fasiello, Matteo; Tolley, Andrew J. E-mail: matte@case.edu E-mail: andrew.j.tolley@case.edu
2013-02-01
We prove that the linear instability in a non-degenerate higher derivative theory, the Ostrogradski instability, can only be removed by the addition of constraints if the original theory's phase space is reduced.
NASA Astrophysics Data System (ADS)
Gusev, M. I.
2016-10-01
We study the penalty function type methods for computing the reachable sets of nonlinear control systems with state constraints. The state constraints are given by a finite system of smooth inequalities. The proposed methods are based on removing the state constraints by replacing the original system with an auxiliary system without constraints. This auxiliary system is obtained by modifying the set of velocities of the original system around the boundary of constraints. The right-hand side of the system depends on a penalty parameter. We prove that the reachable sets of the auxiliary system approximate in the Hausdorff metric the reachable set of the original system with state constraints as the penalty parameter tends to zero (infinity) and give the estimates of the rate of convergence. The numerical algorithms for computing the reachable sets, based on Pontryagin's maximum principle, are also considered.
Kinematics and constraints associated with swashplate blade pitch control
NASA Technical Reports Server (NTRS)
Leyland, Jane A.
1993-01-01
An important class of techniques to reduce helicopter vibration is based on using a Higher Harmonic controller to optimally define the Higher Harmonic blade pitch. These techniques typically require solution of a general optimization problem requiring the determination of a control vector which minimizes a performance index where functions of the control vector are subject to inequality constraints. Six possible constraint functions associated with swashplate blade pitch control were identified and defined. These functions constrain: (1) blade pitch Fourier Coefficients expressed in the Rotating System, (2) blade pitch Fourier Coefficients expressed in the Nonrotating System, (3) stroke of the individual actuators expressed in the Nonrotating System, (4) blade pitch expressed as a function of blade azimuth and actuator stroke, (5) time rate-of-change of the aforementioned parameters, and (6) required actuator power. The aforementioned constraints and the associated kinematics of swashplate blade pitch control by means of the strokes of the individual actuators are documented.
A new spin on causality constraints
NASA Astrophysics Data System (ADS)
Hartman, Thomas; Jain, Sachin; Kundu, Sandipan
2016-10-01
Causality in a shockwave state is related to the analytic properties of a four-point correlation function. Extending recent results for scalar probes, we show that this constrains the couplings of the stress tensor to light spinning operators in conformal field theory, and interpret these constraints in terms of the interaction with null energy. For spin-1 and spin-2 conserved currents in four dimensions, the resulting inequalities are a subset of the Hofman-Maldacena conditions for positive energy deposition. It is well known that energy conditions in holographic theories are related to causality on the gravity side; our results make a connection on the CFT side, and extend it to non-holographic theories.
Identification and robust control of linear parameter-varying systems
NASA Astrophysics Data System (ADS)
Lee, Lawton Hubert
This dissertation deals with linear parameter-varying (LPV) systems: linear dynamic systems that depend on time-varying parameters. These systems appear in gain scheduling problems, and much recent research has been devoted to their prospective usefulness for systematic gain scheduling. We primarily focus on robust control of uncertain LPV systems and identification of LPV systems that are modelable as linear-fractional transformations (LFTs). Using parameter-dependent quadratic Lyapunov functions, linear matrix inequalities (LMIs), and scaled small-gain arguments, we define notions of stability and induced-{cal L}sb2 performance for uncertain LPV systems whose parameters and rates of parameter variation satisfy given bounds. The performance criterion involves integral quadratic constraints and implies naturally parameter-dependent induced-{cal L}sb2 norm bounds. We formulate and solve an {cal H}sb{infty}-like control problem for an LPV plant with measurable parameters and an "Output/State Feedback" structure: the feedback outputs include some noiselessly measured states. Necessary and sufficient solvability conditions reduce to LMIs that can be solved approximately using finite-dimensional convex programming. Reduced-order LPV controllers are constructed from the LMI solutions. A D-K iteration-like procedure provides robustness to structured, time-varying, parametric uncertainty. The design method is applied to a motivating example: flight control for the F-16 VISTA throughout its subsonic flight envelope. Parameter-dependent weights and {cal H}sb{infty} design principles describe the performance objectives. Closed-loop responses exhibited by nonlinear simulations indicate satisfactory flying qualities. Identification of linear-fractional LPV systems is treated using maximum-likelihood parameter estimation. Computing the gradient and Hessian of a maximum-likelihood cost function reduces to simulating one LPV filter per identified parameter. We use nonlinear
Creating Positive Task Constraints
ERIC Educational Resources Information Center
Mally, Kristi K.
2006-01-01
Constraints are characteristics of the individual, the task, or the environment that mold and shape movement choices and performances. Constraints can be positive--encouraging proficient movements or negative--discouraging movement or promoting ineffective movements. Physical educators must analyze, evaluate, and determine the effect various…
Credit Constraints in Education
ERIC Educational Resources Information Center
Lochner, Lance; Monge-Naranjo, Alexander
2012-01-01
We review studies of the impact of credit constraints on the accumulation of human capital. Evidence suggests that credit constraints have recently become important for schooling and other aspects of households' behavior. We highlight the importance of early childhood investments, as their response largely determines the impact of credit…
Creating Positive Task Constraints
ERIC Educational Resources Information Center
Mally, Kristi K.
2006-01-01
Constraints are characteristics of the individual, the task, or the environment that mold and shape movement choices and performances. Constraints can be positive--encouraging proficient movements or negative--discouraging movement or promoting ineffective movements. Physical educators must analyze, evaluate, and determine the effect various…
Constraint Reasoning Over Strings
NASA Technical Reports Server (NTRS)
Koga, Dennis (Technical Monitor); Golden, Keith; Pang, Wanlin
2003-01-01
This paper discusses an approach to representing and reasoning about constraints over strings. We discuss how many string domains can often be concisely represented using regular languages, and how constraints over strings, and domain operations on sets of strings, can be carried out using this representation.
Credit Constraints in Education
ERIC Educational Resources Information Center
Lochner, Lance; Monge-Naranjo, Alexander
2012-01-01
We review studies of the impact of credit constraints on the accumulation of human capital. Evidence suggests that credit constraints have recently become important for schooling and other aspects of households' behavior. We highlight the importance of early childhood investments, as their response largely determines the impact of credit…
NASA Astrophysics Data System (ADS)
Provencher, Stephen W.
1982-09-01
CONTIN is a portable Fortran IV package for inverting noisy linear operator equations. These problems occur in the analysis of data from a wide variety experiments. They are generally ill-posed problems, which means that errors in an unregularized inversion are unbounded. Instead, CONTIN seeks the optimal solution by incorporating parsimony and any statistical prior knowledge into the regularizor and absolute prior knowledge into equallity and inequality constraints. This can be greatly increase the resolution and accuracyh of the solution. CONTIN is very flexible, consisting of a core of about 50 subprograms plus 13 small "USER" subprograms, which the user can easily modify to specify special-purpose constraints, regularizors, operator equations, simulations, statistical weighting, etc. Specjial collections of USER subprograms are available for photon correlation spectroscopy, multicomponent spectra, and Fourier-Bessel, Fourier and Laplace transforms. Numerically stable algorithms are used throughout CONTIN. A fairly precise definition of information content in terms of degrees of freedom is given. The regularization parameter can be automatically chosen on the basis of an F-test and confidence region. The interpretation of the latter and of error estimates based on the covariance matrix of the constrained regularized solution are discussed. The strategies, methods and options in CONTIN are outlined. The program itself is described in the following paper.
Inequalities in perinatal and maternal health.
de Graaf, Johanna P; Steegers, Eric A P; Bonsel, Gouke J
2013-04-01
To describe inequalities in perinatal and maternal mortality, and morbidity from an international high-income country perspective. Measures of inequalities are socioeconomic status, ethnic background, and living area. Despite decreasing overall perinatal and maternal mortality in high-income countries, perinatal and maternal health inequalities persist. Inequalities in fetal, neonatal, and maternal adverse outcome relate to specific groups of risk factors. They commonly have a background in so-called structural risk factors, that is low level of education and income, being a migrant and living in disadvantaged areas. Structural risk factors therefore drive inequalities, and simultaneously represent the common perspective to judge perinatal and maternal health gaps. The effect of risk factors is further magnified in urban areas through risk accumulation.As mother and child share their background, neonatal, and maternal adverse health outcome patterns coincide, resulting in similar inequalities and similar epidemiological trends. The structural background explains the difficulty of improving this. Inequalities in perinatal and maternal outcome persist in women from lower socioeconomic groups, from specific ethnic groups, and from those living in deprived areas. In view of the lifelong consequences, these marked social disparities pose an important challenge for the political decision makers and the healthcare system.
Christofilos, N.C.; Polk, I.J.
1959-02-17
Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.
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.
Construction of Bell inequalities based on the CHSH structure
NASA Astrophysics Data System (ADS)
Liu, Binbin; Wang, Jing; Li, Ming; Shen, Shuqian; Chen, Dongmeng
2017-04-01
It is a computationally hard task to find all Bell inequalities for a given number of parties, measurement settings, and measurement outcomes. We investigate the construction of the Clauser-Horne-Shimony-Holt Bell inequalities, based on which we present a set of new Bell inequalities. The maximal violations of the constructed Bell inequalities are analysed, and computable formulas are derived.
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.
Socioeconomic Status and Health: A New Approach to the Measurement of Bivariate Inequality
Kessels, Roselinde
2017-01-01
We suggest an alternative way to construct a family of indices of socioeconomic inequality of health. Our indices belong to the broad category of linear indices. In contrast to rank-dependent indices, which are defined in terms of the ranks of the socioeconomic variable and the levels of the health variable, our indices are based on the levels of both the socioeconomic and the health variable. We also indicate how the indices can be modified in order to introduce sensitivity to inequality in the socioeconomic distribution and to inequality in the health distribution. As an empirical illustration, we make a comparative study of the relation between income and well-being in 16 European countries using data from the Survey of Health, Ageing and Retirement in Europe (SHARE) Wave 4. PMID:28644405
A multigenerational view of inequality.
Mare, Robert D
2011-02-01
The study of intergenerational mobility and most population research are governed by a two-generation (parent-to-offspring) view of intergenerational influence, to the neglect of the effects of grandparents and other ancestors and nonresident contemporary kin. While appropriate for some populations in some periods, this perspective may omit important sources of intergenerational continuity of family-based social inequality. Social institutions, which transcend individual lives, help support multigenerational influence, particularly at the extreme top and bottom of the social hierarchy, but to some extent in the middle as well. Multigenerational influence also works through demographic processes because families influence subsequent generations through differential fertility and survival, migration, and marriage patterns, as well as through direct transmission of socioeconomic rewards, statuses, and positions. Future research should attend more closely to multigenerational effects; to the tandem nature of demographic and socioeconomic reproduction; and to data, measures, and models that transcend co-resident nuclear families.
[Society, economy, inequities and dengue].
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.
Arbitrary Inequality in Reputation Systems
NASA Astrophysics Data System (ADS)
Frey, Vincenz; van de Rijt, Arnout
2016-12-01
Trust is an essential condition for exchange. Large societies must substitute the trust traditionally provided through kinship and sanctions in small groups to make exchange possible. The rise of internet-supported reputation systems has been celebrated for providing trust at a global scale, enabling the massive volumes of transactions between distant strangers that are characteristic of modern human societies. Here we problematize an overlooked side-effect of reputation systems: Equally trustworthy individuals may realize highly unequal exchange volumes. We report the results of a laboratory experiment that shows emergent differentiation between ex ante equivalent individuals when information on performance in past exchanges is shared. This arbitrary inequality results from cumulative advantage in the reputation-building process: Random initial distinctions grow as parties of good repute are chosen over those lacking a reputation. We conjecture that reputation systems produce artificial concentration in a wide range of markets and leave superior but untried exchange alternatives unexploited.
Arbitrary Inequality in Reputation Systems
Frey, Vincenz; van de Rijt, Arnout
2016-01-01
Trust is an essential condition for exchange. Large societies must substitute the trust traditionally provided through kinship and sanctions in small groups to make exchange possible. The rise of internet-supported reputation systems has been celebrated for providing trust at a global scale, enabling the massive volumes of transactions between distant strangers that are characteristic of modern human societies. Here we problematize an overlooked side-effect of reputation systems: Equally trustworthy individuals may realize highly unequal exchange volumes. We report the results of a laboratory experiment that shows emergent differentiation between ex ante equivalent individuals when information on performance in past exchanges is shared. This arbitrary inequality results from cumulative advantage in the reputation-building process: Random initial distinctions grow as parties of good repute are chosen over those lacking a reputation. We conjecture that reputation systems produce artificial concentration in a wide range of markets and leave superior but untried exchange alternatives unexploited. PMID:27995957
Arbitrary Inequality in Reputation Systems.
Frey, Vincenz; van de Rijt, Arnout
2016-12-20
Trust is an essential condition for exchange. Large societies must substitute the trust traditionally provided through kinship and sanctions in small groups to make exchange possible. The rise of internet-supported reputation systems has been celebrated for providing trust at a global scale, enabling the massive volumes of transactions between distant strangers that are characteristic of modern human societies. Here we problematize an overlooked side-effect of reputation systems: Equally trustworthy individuals may realize highly unequal exchange volumes. We report the results of a laboratory experiment that shows emergent differentiation between ex ante equivalent individuals when information on performance in past exchanges is shared. This arbitrary inequality results from cumulative advantage in the reputation-building process: Random initial distinctions grow as parties of good repute are chosen over those lacking a reputation. We conjecture that reputation systems produce artificial concentration in a wide range of markets and leave superior but untried exchange alternatives unexploited.
Rotorcraft Smoothing Via Linear Time Periodic Methods
2007-07-01
Optimal Control Methodology for Rotor Vibration Smoothing . . 30 vii Page IV. Mathematic Foundations of Linear Time Periodic Systems . . . . 33 4.1 The...62 6.3 The Maximum Likelihood Estimator . . . . . . . . . . . 63 6.4 The Cramer-Rao Inequality . . . . . . . . . . . . . . . . 66 6.4.1 Statistical ...adjustments for vibration reduction. 2.2.2.4 1980’s to late 1990’s. Rotor vibrational reduction methods during the 1980’s began to adopt a mathematical
Discrimination, Perceived Social Inequity, and Mental Health Among Rural-to-Urban Migrants in China
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
Decomposing Wealth-Based Inequalities in Under-Five Mortality in West Africa
BADO, Aristide Romaric; APPUNNI, Sathiya Susuman
2015-01-01
Background: This study aimed to analysis the inequalities of mortality of children under 5 years in West Africa by examining the determinants and contributing factors to the overall inequality concentration in these countries. Method: Data used came from the DHS surveys conducted in the six countries in West Africa: Burkina Faso (2010), Benin (2006), Cote d’Ivoire 2011), Ghana (2008), Mali (2006), Nigeria (2008) and Niger (2012). The concentration index (CI) and Generalized Linear Model (GLM) with logit link were used to access inequality. Results: The results show that in all countries, the poorest Q1 have the highest proportions of deaths: Nigeria (31.4%), Cote d’Ivoire (30.4%) and Ghana (36.4%), over 30% of deaths of children under 5 years are among the children of the poorest (Q1) and the absolute differences of proportions Q1–Q5 are more than 20 points (25.8 in Ghana and 23.6 in Nigeria). The contributing factors of inequalities of child mortality were birth order, maternal age, parity and household size. Our findings also showed that the intensity of inequality varies from one country to another. Conclusion: The most important conclusion of this study is to reduce mortality in children under 5 years, it is needed to reduce economic and social inequalities and improve the country’s economic and social condition. There is a need for monitoring and assessment inequalities by leading causes of death and morbidity among children in the region in order to advance in understanding the gaps and finding a way to reduce them in West Africa countries. PMID:26576370
Drolet, Melanie; Deeks, Shelley L; Kliewer, Erich; Musto, Grace; Lambert, Pascal; Brisson, Marc
2016-04-07
Human papillomavirus (HPV) vaccination programs have been implemented in more than 50 countries. These programs offer tremendous promise of reducing HPV-related disease burden. However, failure to achieve high coverage among high-risk groups may mitigate program success and increase inequalities. We examined sociodemographic inequalities in HPV vaccination coverage in 4 Canadian provinces (Quebec (QC), Ontario (ON), Manitoba (MB), British Columbia (BC)). We obtained annual HPV vaccination coverage of pre-adolescent girls at provincial and regional levels, from the start of programs to 2012/2013. Regions refer to administrative areas responsible for vaccine implementation and monitoring (there are 18/36/10/16 regions in QC/ON/MB/BC). We obtained regions' sociodemographic characteristics from Statistics Canada Census. We used univariate weighted linear regression to examine the associations between regions' sociodemographic characteristics and HPV vaccination coverage. Provincial HPV vaccination coverage is generally high (QC:78%; ON:80%; MB:64%, BC:69%, 2012/13). QC had the highest provincial vaccination coverage since the program start, but had the greatest inequalities. In QC, regional HPV vaccination coverage was lower in regions with higher proportions of socially deprived individuals, immigrants, and/or native English speakers (p<0.0001). These inequalities remained stable over time. Regional-level analysis did not reveal inequalities in ON, MB and BC. School-based HPV vaccination programs have resulted in high vaccination coverage in four Canadian provinces. Nonetheless, high overall coverage did not necessarily translate into equality in coverage. Future work is needed to understand underlying causes of inequalities and how this could impact existing inequalities in HPV-related diseases and overall program success. Copyright © 2016 Elsevier Ltd. All rights reserved.
Income inequality among American states and the incidence of major depression.
Pabayo, Roman; Kawachi, Ichiro; Gilman, Stephen E
2014-02-01
Although cross-sectional and ecological studies have shown that higher area-level income inequality is related to increased risk for depression, few longitudinal studies have been conducted. This investigation examines the relationship between state-level income inequality and major depression among adults participating in a population-based, representative longitudinal study. We used data from the National Epidemiologic Survey on Alcohol and Related Conditions (n=34 653). Respondents completed structured diagnostic interviews at baseline (2001-2002) and follow-up (2004-2005). Weighted multilevel modelling was used to determine if U.S. state-level income inequality (measured by the Gini coefficient) was a significant predictor of depression at baseline and at follow-up, while controlling for individual-level and state-level covariates. We also repeated the longitudinal analyses, excluding those who had a history of depression or at baseline, in order to test whether income inequality was related to incident depression. State-level inequality was associated with increased incidence of depression among women but not men. In comparison to women residing in states belonging to the lowest quintile of income inequality, women were at increased risk for depression in the second (OR=1.18, 95% CI 0.86 to 1.62), third (OR=1.22, 95% CI 0.91 to 1.62), fourth (OR=1.37, 95% CI 1.03 to 1.82) and fifth (OR=1.50, 95% CI 1.14 to 1.96) quintiles at follow-up (p<0.05 for the linear trend). Living in a state with higher income inequality increases the risk for the development of depression among women.
Discrimination, perceived social inequity, and mental health among rural-to-urban migrants in China.
Lin, Danhua; Li, Xiaoming; Wang, Bo; Hong, Yan; Fang, Xiaoyi; Qin, Xiong; Stanton, Bonita
2011-04-01
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.
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.
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.
Symbolic Capital, Consumption, and Health Inequality
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
Optimal Financial Knowledge and Wealth Inequality.
Lusardi, Annamaria; Michaud, Pierre-Carl; Mitchell, Olivia S
2017-04-01
We show that financial knowledge is a key determinant of wealth inequality in a stochastic lifecycle model with endogenous financial knowledge accumulation, where financial knowledge enables individuals to better allocate lifetime resources in a world of uncertainty and imperfect insurance. Moreover, because of how the U.S. social insurance system works, better-educated individuals have most to gain from investing in financial knowledge. Our parsimonious specification generates substantial wealth inequality relative to a one-asset saving model and one where returns on wealth depend on portfolio composition alone. We estimate that 30-40 percent of retirement wealth inequality is accounted for by financial knowledge.
Symbolic capital, consumption, and health inequality.
Sweet, Elizabeth
2011-02-01
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.
Reformulating noncontextuality inequalities in an operational approach
NASA Astrophysics Data System (ADS)
Xu, Zhen-Peng; Saha, Debashis; Su, Hong-Yi; Pawłowski, Marcin; Chen, Jing-Ling
2016-12-01
A new theory-independent noncontextuality inequality is presented [R. Kunjwal and R. W. Spekkens, Phys. Rev. Lett. 115, 110403 (2015), 10.1103/PhysRevLett.115.110403] based on a Kochen-Specker (KS) set without imposing the assumption of determinism. By proposing noncontextuality inequalities, we show that such result can be generalized from a KS set to the noncontextuality inequalities not only for a state-independent scenario but also for a state-dependent scenario. The YO-13 ray and n cycle ray are considered as examples.
Sexism and gender inequality across 57 societies.
Brandt, Mark J
2011-11-01
Theory predicts that individuals' sexism serves to exacerbate inequality in their society's gender hierarchy. Past research, however, has provided only correlational evidence to support this hypothesis. In this study, I analyzed a large longitudinal data set that included representative data from 57 societies. Multilevel modeling showed that sexism directly predicted increases in gender inequality. This study provides the first evidence that sexist ideologies can create gender inequality within societies, and this finding suggests that sexism not only legitimizes the societal status quo, but also actively enhances the severity of the gender hierarchy. Three potential mechanisms for this effect are discussed briefly.
Bayesian Optimization Under Mixed Constraints with A Slack-Variable Augmented Lagrangian
Picheny, Victor; Gramacy, Robert B.; Wild, Stefan M.; Le Digabel, Sebastien
2016-12-05
An augmented Lagrangian (AL) can convert a constrained optimization problem into a sequence of simpler (e.g., unconstrained) problems, which are then usually solved with local solvers. Recently, surrogate-based Bayesian optimization (BO) sub-solvers have been successfully deployed in the AL framework for a more global search in the presence of inequality constraints; however, a drawback was that expected improvement (EI) evaluations relied on Monte Carlo. Here we introduce an alternative slack variable AL, and show that in this formulation the EI may be evaluated with library routines. The slack variables furthermore facilitate equality as well as inequality constraints, and mixtures thereof. We show our new slack “ALBO” compares favorably to the original. Its superiority over conventional alternatives is reinforced on several mixed constraint examples.
Linear Logistic Test Modeling with R
ERIC Educational Resources Information Center
Baghaei, Purya; Kubinger, Klaus D.
2015-01-01
The present paper gives a general introduction to the linear logistic test model (Fischer, 1973), an extension of the Rasch model with linear constraints on item parameters, along with eRm (an R package to estimate different types of Rasch models; Mair, Hatzinger, & Mair, 2014) functions to estimate the model and interpret its parameters. The…
Linear Logistic Test Modeling with R
ERIC Educational Resources Information Center
Baghaei, Purya; Kubinger, Klaus D.
2015-01-01
The present paper gives a general introduction to the linear logistic test model (Fischer, 1973), an extension of the Rasch model with linear constraints on item parameters, along with eRm (an R package to estimate different types of Rasch models; Mair, Hatzinger, & Mair, 2014) functions to estimate the model and interpret its parameters. The…
Tranvåg, Eirik Joakim; Ali, Merima; Norheim, Ole Frithjof
2013-07-11
Most studies on health inequalities use average measures, but describing the distribution of health can also provide valuable knowledge. In this paper, we estimate and compare within-group and between-group inequalities in length of life for population groups in Ethiopia in 2000 and 2011. We used data from the 2011 and 2000 Ethiopia Demographic and Health Survey and the Global Burden of Disease study 2010, and the MODMATCH modified logit life table system developed by the World Health Organization to model mortality rates, life expectancy, and length of life for Ethiopian population groups stratified by wealth quintiles, gender and residence. We then estimated and compared within-group and between-group inequality in length of life using the Gini index and absolute length of life inequality. Length of life inequality has decreased and life expectancy has increased for all population groups between 2000 and 2011. Length of life inequality within wealth quintiles is about three times larger than the between-group inequality of 9 years. Total length of life inequality in Ethiopia was 27.6 years in 2011. Longevity has increased and the distribution of health in Ethiopia is more equal in 2011 than 2000, with length of life inequality reduced for all population groups. Still there is considerable potential for further improvement. In the Ethiopian context with a poor and highly rural population, inequality in length of life within wealth quintiles is considerably larger than between them. This suggests that other factors than wealth substantially contribute to total health inequality in Ethiopia and that identification and quantification of these factors will be important for identifying proper measures to further reduce length of life inequality.
2013-01-01
Background and objectives Most studies on health inequalities use average measures, but describing the distribution of health can also provide valuable knowledge. In this paper, we estimate and compare within-group and between-group inequalities in length of life for population groups in Ethiopia in 2000 and 2011. Methods We used data from the 2011 and 2000 Ethiopia Demographic and Health Survey and the Global Burden of Disease study 2010, and the MODMATCH modified logit life table system developed by the World Health Organization to model mortality rates, life expectancy, and length of life for Ethiopian population groups stratified by wealth quintiles, gender and residence. We then estimated and compared within-group and between-group inequality in length of life using the Gini index and absolute length of life inequality. Results Length of life inequality has decreased and life expectancy has increased for all population groups between 2000 and 2011. Length of life inequality within wealth quintiles is about three times larger than the between-group inequality of 9 years. Total length of life inequality in Ethiopia was 27.6 years in 2011. Conclusion Longevity has increased and the distribution of health in Ethiopia is more equal in 2011 than 2000, with length of life inequality reduced for all population groups. Still there is considerable potential for further improvement. In the Ethiopian context with a poor and highly rural population, inequality in length of life within wealth quintiles is considerably larger than between them. This suggests that other factors than wealth substantially contribute to total health inequality in Ethiopia and that identification and quantification of these factors will be important for identifying proper measures to further reduce length of life inequality. PMID:23845045