WorldWideScience

Sample records for random satisfiability problem

  1. Social balance as a satisfiability problem of computer science.

    Science.gov (United States)

    Radicchi, Filippo; Vilone, Daniele; Yoon, Sooeyon; Meyer-Ortmanns, Hildegard

    2007-02-01

    Reduction of frustration was the driving force in an approach to social balance as it was recently considered by Antal [T. Antal, P. L. Krapivsky, and S. Redner, Phys. Rev. E 72, 036121 (2005)]. We generalize their triad dynamics to k-cycle dynamics for arbitrary integer k. We derive the phase structure, determine the stationary solutions, and calculate the time it takes to reach a frozen state. The main difference in the phase structure as a function of k is related to k being even or odd. As a second generalization we dilute the all-to-all coupling as considered by Antal to a random network with connection probability wcomputer science. The phase of social balance in our original interpretation then becomes the phase of satisfaction of all logical clauses in the satisfiability problem. In common to the cases we study, the ideal solution without any frustration always exists, but the question actually is as to whether this solution can be found by means of a local stochastic algorithm within a finite time. The answer depends on the choice of parameters. After establishing the mapping between the two classes of models, we generalize the social-balance problem to a diluted network topology for which the satisfiability problem is usually studied. On the other hand, in connection with the satisfiability problem we generalize the random local algorithm to a p-random local algorithm, including a parameter p that corresponds to the propensity parameter in the social balance problem. The qualitative effect of the inclusion of this parameter is a bias towards the optimal solution and a reduction of the needed simulation time.

  2. Solving satisfiability problems by the ground-state quantum computer

    International Nuclear Information System (INIS)

    Mao Wenjin

    2005-01-01

    A quantum algorithm is proposed to solve the satisfiability (SAT) problems by the ground-state quantum computer. The scale of the energy gap of the ground-state quantum computer is analyzed for the 3-bit exact cover problem. The time cost of this algorithm on the general SAT problems is discussed

  3. About the problem of generating three-dimensional pseudo-random points.

    Science.gov (United States)

    Carpintero, D. D.

    The author demonstrates that a popular pseudo-random number generator is not adequate in some circumstances to generate n-dimensional random points, n > 2. This problem is particularly noxious when direction cosines are generated. He proposes several soultions, among them a good generator that satisfies all statistical criteria.

  4. A message-passing approach to random constraint satisfaction problems with growing domains

    International Nuclear Information System (INIS)

    Zhao, Chunyan; Zheng, Zhiming; Zhou, Haijun; Xu, Ke

    2011-01-01

    Message-passing algorithms based on belief propagation (BP) are implemented on a random constraint satisfaction problem (CSP) referred to as model RB, which is a prototype of hard random CSPs with growing domain size. In model RB, the number of candidate discrete values (the domain size) of each variable increases polynomially with the variable number N of the problem formula. Although the satisfiability threshold of model RB is exactly known, finding solutions for a single problem formula is quite challenging and attempts have been limited to cases of N ∼ 10 2 . In this paper, we propose two different kinds of message-passing algorithms guided by BP for this problem. Numerical simulations demonstrate that these algorithms allow us to find a solution for random formulas of model RB with constraint tightness slightly less than p cr , the threshold value for the satisfiability phase transition. To evaluate the performance of these algorithms, we also provide a local search algorithm (random walk) as a comparison. Besides this, the simulated time dependence of the problem size N and the entropy of the variables for growing domain size are discussed

  5. Finer Distinctions: Variability in Satisfied Older Couples' Problem-Solving Behaviors.

    Science.gov (United States)

    Rauer, Amy; Williams, Leah; Jensen, Jakob

    2017-06-01

    This study utilized observational and self-report data from 64 maritally satisfied and stable older couples to explore if there were meaningful differences in how couples approached marital disagreements. Using a typology approach to classify couples based on their behaviors in a 15-minute problem-solving interaction, findings revealed four types of couples: (1) problem solvers (characterized by both spouses' higher problem-solving skills and warmth), (2) supporters (characterized by both spouses' notable warmth), (3) even couples (characterized by both spouses' moderate problem-solving skills and warmth), and (4) cool couples (characterized by both spouses' greater negativity and lower problem-solving skills and warmth). Despite the differences in these behaviors, all couples had relatively high marital satisfaction and functioning. However, across nearly all indices, spouses in the cool couple cluster reported poorer marital functioning, particularly when compared to the problem solvers and supporters. These findings suggest that even modest doses of negativity (e.g., eye roll) may be problematic for some satisfied couples later in life. The implications of these typologies are discussed as they pertain to practitioners' efforts to tailor their approaches to a wider swath of the population. © 2015 Family Process Institute.

  6. An application of reactor noise techniques to neutron transport problems in a random medium

    International Nuclear Information System (INIS)

    Sahni, D.C.

    1989-01-01

    Neutron transport problems in a random medium are considered by defining a joint Markov process describing the fluctuations of one neutron population and the random changes in the medium. Backward Chapman-Kolmogorov equations are derived which yield an adjoint transport equation for the average neutron density. It is shown that this average density also satisfied the direct transport equation as given by the phenomenological model. (author)

  7. A Maximin Approach for the Bi-criteria 0-1 Random Fuzzy Programming Problem Based on the Necessity Measure

    International Nuclear Information System (INIS)

    Hasuike, Takashi; Ishii, Hiroaki; Katagiri, Hideki

    2009-01-01

    This paper considers a bi-criteria general 0-1 random fuzzy programming problem based on the degree of necessity which include some previous 0-1 stochastic and fuzzy programming problems. The proposal problem is not well-defined due to including randomness and fuzziness. Therefore, by introducing chance constraint and fuzzy goals for objectives, and considering the maximization of the aspiration level for total profit and the degree of necessity that the objective function's value satisfies the fuzzy goal, the main problem is transformed into a deterministic equivalent problem. Furthermore, by using the assumption that each random variable is distributed according to a normal distribution, the problem is equivalently transformed into a basic 0-1 programming problem, and the efficient strict solution method to find an optimal solution is constructed.

  8. Multipath Detection Using Boolean Satisfiability Techniques

    Directory of Open Access Journals (Sweden)

    Fadi A. Aloul

    2011-01-01

    Full Text Available A new technique for multipath detection in wideband mobile radio systems is presented. The proposed scheme is based on an intelligent search algorithm using Boolean Satisfiability (SAT techniques to search through the uncertainty region of the multipath delays. The SAT-based scheme utilizes the known structure of the transmitted wideband signal, for example, pseudo-random (PN code, to effectively search through the entire space by eliminating subspaces that do not contain a possible solution. The paper presents a framework for modeling the multipath detection problem as a SAT application. It also provides simulation results that demonstrate the effectiveness of the proposed scheme in detecting the multipath components in frequency-selective Rayleigh fading channels.

  9. Introduction to mathematics of satisfiability

    CERN Document Server

    Marek, Victor W

    2009-01-01

    Although this area has a history of over 80 years, it was not until the creation of efficient SAT solvers in the mid-1990s that it became practically important, finding applications in electronic design automation, hardware and software verification, combinatorial optimization, and more. Exploring the theoretical and practical aspects of satisfiability, Introduction to Mathematics of Satisfiability focuses on the satisfiability of theories consisting of propositional logic formulas. It describes how SAT solvers and techniques are applied to problems in mathematics and computer science as well

  10. Bounded Satisfiability for PCTL

    OpenAIRE

    Bertrand, Nathalie; Fearnley, John; Schewe, Sven

    2012-01-01

    While model checking PCTL for Markov chains is decidable in polynomial-time, the decidability of PCTL satisfiability, as well as its finite model property, are long standing open problems. While general satisfiability is an intriguing challenge from a purely theoretical point of view, we argue that general solutions would not be of interest to practitioners: such solutions could be too big to be implementable or even infinite. Inspired by bounded synthesis techniques, we turn to the more appl...

  11. Diffusion Processes Satisfying a Conservation Law Constraint

    Directory of Open Access Journals (Sweden)

    J. Bakosi

    2014-01-01

    Full Text Available We investigate coupled stochastic differential equations governing N nonnegative continuous random variables that satisfy a conservation principle. In various fields a conservation law requires a set of fluctuating variables to be nonnegative and (if appropriately normalized sum to one. As a result, any stochastic differential equation model to be realizable must not produce events outside of the allowed sample space. We develop a set of constraints on the drift and diffusion terms of such stochastic models to ensure that both the nonnegativity and the unit-sum conservation law constraints are satisfied as the variables evolve in time. We investigate the consequences of the developed constraints on the Fokker-Planck equation, the associated system of stochastic differential equations, and the evolution equations of the first four moments of the probability density function. We show that random variables, satisfying a conservation law constraint, represented by stochastic diffusion processes, must have diffusion terms that are coupled and nonlinear. The set of constraints developed enables the development of statistical representations of fluctuating variables satisfying a conservation law. We exemplify the results with the bivariate beta process and the multivariate Wright-Fisher, Dirichlet, and Lochner’s generalized Dirichlet processes.

  12. SmArT solving : Tools and techniques for satisfiability solvers

    NARCIS (Netherlands)

    Heule, M.J.H.

    2008-01-01

    The satisfiability problem (Sat) lies at the core of the complexity theory. This is a decision problem: Not the solution itself, but whether or not a solution exists given a specified set of requirements is the central question. Over the years, the satisfiability problem has taken center stage as a

  13. Cliques, coloring, and satisfiability

    CERN Document Server

    Johnson, David S

    1996-01-01

    The purpose of a DIMACS Challenge is to encourage and coordinate research in the experimental analysis of algorithms. The First DIMACS Challenge encouraged experimental work in the area of network flow and matchings. The Second DIMACS Challenge, on which this volume is based, took place in conjunction with the DIMACS Special Year on Combinatorial Optimization. Addressed here are three difficult combinatorial optimization problems: finding cliques in a graph, coloring the vertices of a graph, and solving instances of the satisfiability problem. These problems were chosen both for their practical interest and because of their theoretical intractability.

  14. Post optimization paradigm in maximum 3-satisfiability logic programming

    Science.gov (United States)

    Mansor, Mohd. Asyraf; Sathasivam, Saratha; Kasihmuddin, Mohd Shareduwan Mohd

    2017-08-01

    Maximum 3-Satisfiability (MAX-3SAT) is a counterpart of the Boolean satisfiability problem that can be treated as a constraint optimization problem. It deals with a conundrum of searching the maximum number of satisfied clauses in a particular 3-SAT formula. This paper presents the implementation of enhanced Hopfield network in hastening the Maximum 3-Satisfiability (MAX-3SAT) logic programming. Four post optimization techniques are investigated, including the Elliot symmetric activation function, Gaussian activation function, Wavelet activation function and Hyperbolic tangent activation function. The performances of these post optimization techniques in accelerating MAX-3SAT logic programming will be discussed in terms of the ratio of maximum satisfied clauses, Hamming distance and the computation time. Dev-C++ was used as the platform for training, testing and validating our proposed techniques. The results depict the Hyperbolic tangent activation function and Elliot symmetric activation function can be used in doing MAX-3SAT logic programming.

  15. PREFACE: The random search problem: trends and perspectives The random search problem: trends and perspectives

    Science.gov (United States)

    da Luz, Marcos G. E.; Grosberg, Alexander; Raposo, Ernesto P.; Viswanathan, Gandhi M.

    2009-10-01

    `I can't find my keys!' Who hasn't gone through this experience when leaving, in a hurry, to attend to some urgent matter? The keys could be in many different places. Unless one remembers where he or she has left the keys, the only solution is to look around, more or less randomly. Random searches are common because in many cases the locations of the specific targets are not known a priori. Indeed, such problems have been discussed in diverse contexts, attracting the interest of scientists from many fields, for example: the dynamical or stochastic search for a stable minimum in a complex energy landscape, relevant to systems such as glasses, protein (folding), and others; oil recovery from mature reservoirs; proteins searching for their specific target sites on DNA; animal foraging; survival at the edge of extinction due to low availability of energetic resources; automated searches of registers in high-capacity databases, search engine (e.g., `crawlers') that explore the internet; and even pizza delivery in a jammed traffic system of a medium-size town. In this way, the subject is interesting, challenging and has recently become an important scientific area of investigation. Although the applications are diverse, the underlying physical mechanisms are the same which will become clear in this special issue. Moreover, the inherent complexity of the problem, the abundance of ideas and methods found in this growing interdisciplinary field of research is studied in many areas of physics. In particular, the concepts and methods of statistical mechanics are particularly useful to the study of random searches. On one hand, it centres on how to find the global or local maxima of search efficiency functions with incomplete information. This is, of course, related to the long tradition in physics of using different conceptual and mathematical tools, such as variational methods, to extremize relevant quantities, e.g., energy, entropy and action. Such ideas and approaches are

  16. Sampling problems for randomly broken sticks

    Energy Technology Data Exchange (ETDEWEB)

    Huillet, Thierry [Laboratoire de Physique Theorique et Modelisation, CNRS-UMR 8089 et Universite de Cergy-Pontoise, 5 mail Gay-Lussac, 95031, Neuville sur Oise (France)

    2003-04-11

    Consider the random partitioning model of a population (represented by a stick of length 1) into n species (fragments) with identically distributed random weights (sizes). Upon ranking the fragments' weights according to ascending sizes, let S{sub m:n} be the size of the mth smallest fragment. Assume that some observer is sampling such populations as follows: drop at random k points (the sample size) onto this stick and record the corresponding numbers of visited fragments. We shall investigate the following sampling problems: (1) what is the sample size if the sampling is carried out until the first visit of the smallest fragment (size S{sub 1:n})? (2) For a given sample size, have all the fragments of the stick been visited at least once or not? This question is related to Feller's random coupon collector problem. (3) In what order are new fragments being discovered and what is the random number of samples separating the discovery of consecutive new fragments until exhaustion of the list? For this problem, the distribution of the size-biased permutation of the species' weights, as the sequence of their weights in their order of appearance is needed and studied.

  17. Portfolio optimization and the random magnet problem

    Science.gov (United States)

    Rosenow, B.; Plerou, V.; Gopikrishnan, P.; Stanley, H. E.

    2002-08-01

    Diversification of an investment into independently fluctuating assets reduces its risk. In reality, movements of assets are mutually correlated and therefore knowledge of cross-correlations among asset price movements are of great importance. Our results support the possibility that the problem of finding an investment in stocks which exposes invested funds to a minimum level of risk is analogous to the problem of finding the magnetization of a random magnet. The interactions for this "random magnet problem" are given by the cross-correlation matrix C of stock returns. We find that random matrix theory allows us to make an estimate for C which outperforms the standard estimate in terms of constructing an investment which carries a minimum level of risk.

  18. Mathematical conversations multicolor problems, problems in the theory of numbers, and random walks

    CERN Document Server

    Dynkin, E B

    2006-01-01

    Comprises Multicolor Problems, dealing with map-coloring problems; Problems in the Theory of Numbers, an elementary introduction to algebraic number theory; Random Walks, addressing basic problems in probability theory. 1963 edition.

  19. A Geometric Presentation of Probabilistic Satisfiability

    OpenAIRE

    Morales-Luna, Guillermo

    2010-01-01

    By considering probability distributions over the set of assignments the expected truth values assignment to propositional variables are extended through linear operators, and the expected truth values of the clauses at any given conjunctive form are also extended through linear maps. The probabilistic satisfiability problems are discussed in terms of the introduced linear extensions. The case of multiple truth values is also discussed.

  20. Constraint programming for modelling and solving modal satisfiability

    NARCIS (Netherlands)

    Brand, S.; Gennari, R.; de Rijke, M.

    2003-01-01

    We explore to what extent and how efficiently constraint programmingcan be used in the context of automated reasoning for modal logics. We encode modal satisfiability problems as constraint satisfactionproblems with non-boolean domains, together with suitable constraints.Experiments show that the

  1. Application of random survival forests in understanding the determinants of under-five child mortality in Uganda in the presence of covariates that satisfy the proportional and non-proportional hazards assumption.

    Science.gov (United States)

    Nasejje, Justine B; Mwambi, Henry

    2017-09-07

    Uganda just like any other Sub-Saharan African country, has a high under-five child mortality rate. To inform policy on intervention strategies, sound statistical methods are required to critically identify factors strongly associated with under-five child mortality rates. The Cox proportional hazards model has been a common choice in analysing data to understand factors strongly associated with high child mortality rates taking age as the time-to-event variable. However, due to its restrictive proportional hazards (PH) assumption, some covariates of interest which do not satisfy the assumption are often excluded in the analysis to avoid mis-specifying the model. Otherwise using covariates that clearly violate the assumption would mean invalid results. Survival trees and random survival forests are increasingly becoming popular in analysing survival data particularly in the case of large survey data and could be attractive alternatives to models with the restrictive PH assumption. In this article, we adopt random survival forests which have never been used in understanding factors affecting under-five child mortality rates in Uganda using Demographic and Health Survey data. Thus the first part of the analysis is based on the use of the classical Cox PH model and the second part of the analysis is based on the use of random survival forests in the presence of covariates that do not necessarily satisfy the PH assumption. Random survival forests and the Cox proportional hazards model agree that the sex of the household head, sex of the child, number of births in the past 1 year are strongly associated to under-five child mortality in Uganda given all the three covariates satisfy the PH assumption. Random survival forests further demonstrated that covariates that were originally excluded from the earlier analysis due to violation of the PH assumption were important in explaining under-five child mortality rates. These covariates include the number of children under the

  2. Inverse problems for random differential equations using the collage method for random contraction mappings

    Science.gov (United States)

    Kunze, H. E.; La Torre, D.; Vrscay, E. R.

    2009-01-01

    In this paper we are concerned with differential equations with random coefficients which will be considered as random fixed point equations of the form T([omega],x([omega]))=x([omega]), [omega][set membership, variant][Omega]. Here T:[Omega]×X-->X is a random integral operator, is a probability space and X is a complete metric space. We consider the following inverse problem for such equations: Given a set of realizations of the fixed point of T (possibly the interpolations of different observational data sets), determine the operator T or the mean value of its random components, as appropriate. We solve the inverse problem for this class of equations by using the collage theorem for contraction mappings.

  3. What keeps Melbourne GPs satisfied in their jobs?

    Science.gov (United States)

    Walker, Kate Anne; Pirotta, Marie

    2007-10-01

    Workforce shortages make it important to promote job satisfaction and career longevity in general practitioners. We aimed to investigate strategies that maintain and improve Melbourne (Victoria) GP job satisfaction. A postal survey of a random selection of The Royal Australian College of General Practitioners vocationally recognised GPs (N=860). Open ended answers were coded according to themes and compared between genders. Thirty-eight percent of surveyed GPs responded. The mean satisfaction score was 50 out of 70 (SD 9). Women GPs were more satisfied than men with life-work balance (pwork and intellectual stimulation. Strategies to improve GP satisfaction were increased pay, reduced paperwork, and improved administrative systems. General practitioners were satisfied with their jobs due to the intrinsic qualities of their work and workplace. Decreasing the administrative burden, increasing remuneration and improving practice supports may improve metropolitan GP job satisfaction.

  4. [Intel random number generator-based true random number generator].

    Science.gov (United States)

    Huang, Feng; Shen, Hong

    2004-09-01

    To establish a true random number generator on the basis of certain Intel chips. The random numbers were acquired by programming using Microsoft Visual C++ 6.0 via register reading from the random number generator (RNG) unit of an Intel 815 chipset-based computer with Intel Security Driver (ISD). We tested the generator with 500 random numbers in NIST FIPS 140-1 and X(2) R-Squared test, and the result showed that the random number it generated satisfied the demand of independence and uniform distribution. We also compared the random numbers generated by Intel RNG-based true random number generator and those from the random number table statistically, by using the same amount of 7500 random numbers in the same value domain, which showed that the SD, SE and CV of Intel RNG-based random number generator were less than those of the random number table. The result of u test of two CVs revealed no significant difference between the two methods. Intel RNG-based random number generator can produce high-quality random numbers with good independence and uniform distribution, and solves some problems with random number table in acquisition of the random numbers.

  5. Random Matrix Approach for Primal-Dual Portfolio Optimization Problems

    Science.gov (United States)

    Tada, Daichi; Yamamoto, Hisashi; Shinzato, Takashi

    2017-12-01

    In this paper, we revisit the portfolio optimization problems of the minimization/maximization of investment risk under constraints of budget and investment concentration (primal problem) and the maximization/minimization of investment concentration under constraints of budget and investment risk (dual problem) for the case that the variances of the return rates of the assets are identical. We analyze both optimization problems by the Lagrange multiplier method and the random matrix approach. Thereafter, we compare the results obtained from our proposed approach with the results obtained in previous work. Moreover, we use numerical experiments to validate the results obtained from the replica approach and the random matrix approach as methods for analyzing both the primal and dual portfolio optimization problems.

  6. Statistical physics of hard optimization problems

    International Nuclear Information System (INIS)

    Zdeborova, L.

    2009-01-01

    Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial (NP)-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an NP-complete problem the practically arising instances might, in fact, be easy to solve. The principal question we address in this article is: How to recognize if an NP-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfy ability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named ”locked” constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfy ability.

  7. Statistical physics of hard optimization problems

    International Nuclear Information System (INIS)

    Zdeborova, L.

    2009-01-01

    Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an non-deterministic polynomial-complete problem the practically arising instances might, in fact, be easy to solve. The principal the question we address in the article is: How to recognize if an non-deterministic polynomial-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfiability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named 'locked' constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfiability (Authors)

  8. Statistical physics of hard optimization problems

    Science.gov (United States)

    Zdeborová, Lenka

    2009-06-01

    Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial (NP)-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an NP-complete problem the practically arising instances might, in fact, be easy to solve. The principal question we address in this article is: How to recognize if an NP-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfiability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named "locked" constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfiability.

  9. Monomer-dimer problem on random planar honeycomb lattice

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Haizhen [School of Mathematical Sciences, Xiamen University, Xiamen 361005, Fujian (China); Department of Mathematics, Qinghai Normal University, Xining 810008, Qinghai (China); Zhang, Fuji; Qian, Jianguo, E-mail: jqqian@xmu.edu.cn [School of Mathematical Sciences, Xiamen University, Xiamen 361005, Fujian (China)

    2014-02-15

    We consider the monomer-dimer (MD) problem on a random planar honeycomb lattice model, namely, the random multiple chain. This is a lattice system with non-periodic boundary condition, whose generating process is inspired by the growth of single walled zigzag carbon nanotubes. By applying algebraic and combinatorial techniques we establish a calculating expression of the MD partition function for bipartite graphs, which corresponds to the permanent of a matrix. Further, by using the transfer matrix argument we show that the computing problem of the permanent of high order matrix can be converted into some lower order matrices for this family of lattices, based on which we derive an explicit recurrence formula for evaluating the MD partition function of multiple chains and random multiple chains. Finally, we analyze the expectation of the number of monomer-dimer arrangements on a random multiple chain and the asymptotic behavior of the annealed MD entropy when the multiple chain becomes infinite in width and length, respectively.

  10. Problems in probability theory, mathematical statistics and theory of random functions

    CERN Document Server

    Sveshnikov, A A

    1979-01-01

    Problem solving is the main thrust of this excellent, well-organized workbook. Suitable for students at all levels in probability theory and statistics, the book presents over 1,000 problems and their solutions, illustrating fundamental theory and representative applications in the following fields: Random Events; Distribution Laws; Correlation Theory; Random Variables; Entropy & Information; Markov Processes; Systems of Random Variables; Limit Theorems; Data Processing; and more.The coverage of topics is both broad and deep, ranging from the most elementary combinatorial problems through lim

  11. Quiet planting in the locked constraints satisfaction problems

    Energy Technology Data Exchange (ETDEWEB)

    Zdeborova, Lenka [Los Alamos National Laboratory; Krzakala, Florent [Los Alamos National Laboratory

    2009-01-01

    We study the planted ensemble of locked constraint satisfaction problems. We describe the connection between the random and planted ensembles. The use of the cavity method is combined with arguments from reconstruction on trees and first and second moment considerations; in particular the connection with the reconstruction on trees appears to be crucial. Our main result is the location of the hard region in the planted ensemble, thus providing hard satisfiable benchmarks. In a part of that hard region instances have with high probability a single satisfying assignment.

  12. Constructing space difference schemes which satisfy a cell entropy inequality

    Science.gov (United States)

    Merriam, Marshal L.

    1989-01-01

    A numerical methodology for solving convection problems is presented, using finite difference schemes which satisfy the second law of thermodynamics on a cell-by-cell basis in addition to the usual conservation laws. It is shown that satisfaction of a cell entropy inequality is sufficient, in some cases, to guarantee nonlinear stability. Some details are given for several one-dimensional problems, including the quasi-one-dimensional Euler equations applied to flow in a nozzle.

  13. Complementary Set Matrices Satisfying a Column Correlation Constraint

    OpenAIRE

    Wu, Di; Spasojevic, Predrag

    2006-01-01

    Motivated by the problem of reducing the peak to average power ratio (PAPR) of transmitted signals, we consider a design of complementary set matrices whose column sequences satisfy a correlation constraint. The design algorithm recursively builds a collection of $2^{t+1}$ mutually orthogonal (MO) complementary set matrices starting from a companion pair of sequences. We relate correlation properties of column sequences to that of the companion pair and illustrate how to select an appropriate...

  14. Orthology and paralogy constraints: satisfiability and consistency.

    Science.gov (United States)

    Lafond, Manuel; El-Mabrouk, Nadia

    2014-01-01

    A variety of methods based on sequence similarity, reconciliation, synteny or functional characteristics, can be used to infer orthology and paralogy relations between genes of a given gene family  G. But is a given set  C of orthology/paralogy constraints possible, i.e., can they simultaneously co-exist in an evolutionary history for  G? While previous studies have focused on full sets of constraints, here we consider the general case where  C does not necessarily involve a constraint for each pair of genes. The problem is subdivided in two parts: (1) Is  C satisfiable, i.e. can we find an event-labeled gene tree G inducing  C? (2) Is there such a G which is consistent, i.e., such that all displayed triplet phylogenies are included in a species tree? Previous results on the Graph sandwich problem can be used to answer to (1), and we provide polynomial-time algorithms for satisfiability and consistency with a given species tree. We also describe a new polynomial-time algorithm for the case of consistency with an unknown species tree and full knowledge of pairwise orthology/paralogy relationships, as well as a branch-and-bound algorithm in the case when unknown relations are present. We show that our algorithms can be used in combination with ProteinOrtho, a sequence similarity-based orthology detection tool, to extract a set of robust orthology/paralogy relationships.

  15. Expected Fitness Gains of Randomized Search Heuristics for the Traveling Salesperson Problem.

    Science.gov (United States)

    Nallaperuma, Samadhi; Neumann, Frank; Sudholt, Dirk

    2017-01-01

    Randomized search heuristics are frequently applied to NP-hard combinatorial optimization problems. The runtime analysis of randomized search heuristics has contributed tremendously to our theoretical understanding. Recently, randomized search heuristics have been examined regarding their achievable progress within a fixed-time budget. We follow this approach and present a fixed-budget analysis for an NP-hard combinatorial optimization problem. We consider the well-known Traveling Salesperson Problem (TSP) and analyze the fitness increase that randomized search heuristics are able to achieve within a given fixed-time budget. In particular, we analyze Manhattan and Euclidean TSP instances and Randomized Local Search (RLS), (1+1) EA and (1+[Formula: see text]) EA algorithms for the TSP in a smoothed complexity setting, and derive the lower bounds of the expected fitness gain for a specified number of generations.

  16. Multiobjective Two-Stage Stochastic Programming Problems with Interval Discrete Random Variables

    Directory of Open Access Journals (Sweden)

    S. K. Barik

    2012-01-01

    Full Text Available Most of the real-life decision-making problems have more than one conflicting and incommensurable objective functions. In this paper, we present a multiobjective two-stage stochastic linear programming problem considering some parameters of the linear constraints as interval type discrete random variables with known probability distribution. Randomness of the discrete intervals are considered for the model parameters. Further, the concepts of best optimum and worst optimum solution are analyzed in two-stage stochastic programming. To solve the stated problem, first we remove the randomness of the problem and formulate an equivalent deterministic linear programming model with multiobjective interval coefficients. Then the deterministic multiobjective model is solved using weighting method, where we apply the solution procedure of interval linear programming technique. We obtain the upper and lower bound of the objective function as the best and the worst value, respectively. It highlights the possible risk involved in the decision-making tool. A numerical example is presented to demonstrate the proposed solution procedure.

  17. A new neural network model for solving random interval linear programming problems.

    Science.gov (United States)

    Arjmandzadeh, Ziba; Safi, Mohammadreza; Nazemi, Alireza

    2017-05-01

    This paper presents a neural network model for solving random interval linear programming problems. The original problem involving random interval variable coefficients is first transformed into an equivalent convex second order cone programming problem. A neural network model is then constructed for solving the obtained convex second order cone problem. Employing Lyapunov function approach, it is also shown that the proposed neural network model is stable in the sense of Lyapunov and it is globally convergent to an exact satisfactory solution of the original problem. Several illustrative examples are solved in support of this technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Observers for a class of systems with nonlinearities satisfying an incremental quadratic inequality

    Science.gov (United States)

    Acikmese, Ahmet Behcet; Martin, Corless

    2004-01-01

    We consider the problem of state estimation from nonlinear time-varying system whose nonlinearities satisfy an incremental quadratic inequality. Observers are presented which guarantee that the state estimation error exponentially converges to zero.

  19. Multilevel variance estimators in MLMC and application for random obstacle problems

    KAUST Repository

    Chernov, Alexey

    2014-01-06

    The Multilevel Monte Carlo Method (MLMC) is a recently established sampling approach for uncertainty propagation for problems with random parameters. In this talk we present new convergence theorems for the multilevel variance estimators. As a result, we prove that under certain assumptions on the parameters, the variance can be estimated at essentially the same cost as the mean, and consequently as the cost required for solution of one forward problem for a fixed deterministic set of parameters. We comment on fast and stable evaluation of the estimators suitable for parallel large scale computations. The suggested approach is applied to a class of scalar random obstacle problems, a prototype of contact between deformable bodies. In particular, we are interested in rough random obstacles modelling contact between car tires and variable road surfaces. Numerical experiments support and complete the theoretical analysis.

  20. Multilevel variance estimators in MLMC and application for random obstacle problems

    KAUST Repository

    Chernov, Alexey; Bierig, Claudio

    2014-01-01

    The Multilevel Monte Carlo Method (MLMC) is a recently established sampling approach for uncertainty propagation for problems with random parameters. In this talk we present new convergence theorems for the multilevel variance estimators. As a result, we prove that under certain assumptions on the parameters, the variance can be estimated at essentially the same cost as the mean, and consequently as the cost required for solution of one forward problem for a fixed deterministic set of parameters. We comment on fast and stable evaluation of the estimators suitable for parallel large scale computations. The suggested approach is applied to a class of scalar random obstacle problems, a prototype of contact between deformable bodies. In particular, we are interested in rough random obstacles modelling contact between car tires and variable road surfaces. Numerical experiments support and complete the theoretical analysis.

  1. Asymmetrically dominated choice problems, the isolation hypothesis and random incentive mechanisms.

    Directory of Open Access Journals (Sweden)

    James C Cox

    Full Text Available This paper presents an experimental study of the random incentive mechanisms which are a standard procedure in economic and psychological experiments. Random incentive mechanisms have several advantages but are incentive-compatible only if responses to the single tasks are independent. This is true if either the independence axiom of expected utility theory or the isolation hypothesis of prospect theory holds. We present a simple test of this in the context of choice under risk. In the baseline (one task treatment we observe risk behavior in a given choice problem. We show that by integrating a second, asymmetrically dominated choice problem in a random incentive mechanism risk behavior can be manipulated systematically. This implies that the isolation hypothesis is violated and the random incentive mechanism does not elicit true preferences in our example.

  2. Asymmetrically dominated choice problems, the isolation hypothesis and random incentive mechanisms.

    Science.gov (United States)

    Cox, James C; Sadiraj, Vjollca; Schmidt, Ulrich

    2014-01-01

    This paper presents an experimental study of the random incentive mechanisms which are a standard procedure in economic and psychological experiments. Random incentive mechanisms have several advantages but are incentive-compatible only if responses to the single tasks are independent. This is true if either the independence axiom of expected utility theory or the isolation hypothesis of prospect theory holds. We present a simple test of this in the context of choice under risk. In the baseline (one task) treatment we observe risk behavior in a given choice problem. We show that by integrating a second, asymmetrically dominated choice problem in a random incentive mechanism risk behavior can be manipulated systematically. This implies that the isolation hypothesis is violated and the random incentive mechanism does not elicit true preferences in our example.

  3. Random functions via Dyson Brownian Motion: progress and problems

    International Nuclear Information System (INIS)

    Wang, Gaoyuan; Battefeld, Thorsten

    2016-01-01

    We develope a computationally efficient extension of the Dyson Brownian Motion (DBM) algorithm to generate random function in C"2 locally. We further explain that random functions generated via DBM show an unstable growth as the traversed distance increases. This feature restricts the use of such functions considerably if they are to be used to model globally defined ones. The latter is the case if one uses random functions to model landscapes in string theory. We provide a concrete example, based on a simple axionic potential often used in cosmology, to highlight this problem and also offer an ad hoc modification of DBM that suppresses this growth to some degree.

  4. Random functions via Dyson Brownian Motion: progress and problems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gaoyuan; Battefeld, Thorsten [Institute for Astrophysics, University of Goettingen,Friedrich Hund Platz 1, D-37077 Goettingen (Germany)

    2016-09-05

    We develope a computationally efficient extension of the Dyson Brownian Motion (DBM) algorithm to generate random function in C{sup 2} locally. We further explain that random functions generated via DBM show an unstable growth as the traversed distance increases. This feature restricts the use of such functions considerably if they are to be used to model globally defined ones. The latter is the case if one uses random functions to model landscapes in string theory. We provide a concrete example, based on a simple axionic potential often used in cosmology, to highlight this problem and also offer an ad hoc modification of DBM that suppresses this growth to some degree.

  5. On selfadjoint functors satisfying polynomial relations

    DEFF Research Database (Denmark)

    Agerholm, Troels; Mazorchuk, Volodomyr

    2011-01-01

    We study selfadjoint functors acting on categories of finite dimen- sional modules over finite dimensional algebras with an emphasis on functors satisfying some polynomial relations. Selfadjoint func- tors satisfying several easy relations, in particular, idempotents and square roots of a sum...

  6. Energy levels of one-dimensional systems satisfying the minimal length uncertainty relation

    Energy Technology Data Exchange (ETDEWEB)

    Bernardo, Reginald Christian S., E-mail: rcbernardo@nip.upd.edu.ph; Esguerra, Jose Perico H., E-mail: jesguerra@nip.upd.edu.ph

    2016-10-15

    The standard approach to calculating the energy levels for quantum systems satisfying the minimal length uncertainty relation is to solve an eigenvalue problem involving a fourth- or higher-order differential equation in quasiposition space. It is shown that the problem can be reformulated so that the energy levels of these systems can be obtained by solving only a second-order quasiposition eigenvalue equation. Through this formulation the energy levels are calculated for the following potentials: particle in a box, harmonic oscillator, Pöschl–Teller well, Gaussian well, and double-Gaussian well. For the particle in a box, the second-order quasiposition eigenvalue equation is a second-order differential equation with constant coefficients. For the harmonic oscillator, Pöschl–Teller well, Gaussian well, and double-Gaussian well, a method that involves using Wronskians has been used to solve the second-order quasiposition eigenvalue equation. It is observed for all of these quantum systems that the introduction of a nonzero minimal length uncertainty induces a positive shift in the energy levels. It is shown that the calculation of energy levels in systems satisfying the minimal length uncertainty relation is not limited to a small number of problems like particle in a box and the harmonic oscillator but can be extended to a wider class of problems involving potentials such as the Pöschl–Teller and Gaussian wells.

  7. Random fixed point equations and inverse problems using "collage method" for contraction mappings

    Science.gov (United States)

    Kunze, H. E.; La Torre, D.; Vrscay, E. R.

    2007-10-01

    In this paper we are interested in the direct and inverse problems for the following class of random fixed point equations T(w,x(w))=x(w) where is a given operator, [Omega] is a probability space and X is a Polish metric space. The inverse problem is solved by recourse to the collage theorem for contractive maps. We then consider two applications: (i) random integral equations, and (ii) random iterated function systems with greyscale maps (RIFSM), for which noise is added to the classical IFSM.

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

    Science.gov (United States)

    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.

  9. Constraint satisfaction problems with isolated solutions are hard

    International Nuclear Information System (INIS)

    Zdeborová, Lenka; Mézard, Marc

    2008-01-01

    We study the phase diagram and the algorithmic hardness of the random 'locked' constraint satisfaction problems, and compare them to the commonly studied 'non-locked' problems like satisfiability of Boolean formulae or graph coloring. The special property of the locked problems is that clusters of solutions are isolated points. This simplifies significantly the determination of the phase diagram, which makes the locked problems particularly appealing from the mathematical point of view. On the other hand, we show empirically that the clustered phase of these problems is extremely hard from the algorithmic point of view: the best known algorithms all fail to find solutions. Our results suggest that the easy/hard transition (for currently known algorithms) in the locked problems coincides with the clustering transition. These should thus be regarded as new benchmarks of really hard constraint satisfaction problems

  10. Possibility/Necessity-Based Probabilistic Expectation Models for Linear Programming Problems with Discrete Fuzzy Random Variables

    Directory of Open Access Journals (Sweden)

    Hideki Katagiri

    2017-10-01

    Full Text Available This paper considers linear programming problems (LPPs where the objective functions involve discrete fuzzy random variables (fuzzy set-valued discrete random variables. New decision making models, which are useful in fuzzy stochastic environments, are proposed based on both possibility theory and probability theory. In multi-objective cases, Pareto optimal solutions of the proposed models are newly defined. Computational algorithms for obtaining the Pareto optimal solutions of the proposed models are provided. It is shown that problems involving discrete fuzzy random variables can be transformed into deterministic nonlinear mathematical programming problems which can be solved through a conventional mathematical programming solver under practically reasonable assumptions. A numerical example of agriculture production problems is given to demonstrate the applicability of the proposed models to real-world problems in fuzzy stochastic environments.

  11. Some open problems in random matrix theory and the theory of integrable systems

    OpenAIRE

    Deift, Percy

    2007-01-01

    We describe a list of open problems in random matrix theory and integrable systems which was presented at the conference ``Integrable Systems, Random Matrices, and Applications'' at the Courant Institute in May 2006.

  12. Raney Distributions and Random Matrix Theory

    Science.gov (United States)

    Forrester, Peter J.; Liu, Dang-Zheng

    2015-03-01

    Recent works have shown that the family of probability distributions with moments given by the Fuss-Catalan numbers permit a simple parameterized form for their density. We extend this result to the Raney distribution which by definition has its moments given by a generalization of the Fuss-Catalan numbers. Such computations begin with an algebraic equation satisfied by the Stieltjes transform, which we show can be derived from the linear differential equation satisfied by the characteristic polynomial of random matrix realizations of the Raney distribution. For the Fuss-Catalan distribution, an equilibrium problem characterizing the density is identified. The Stieltjes transform for the limiting spectral density of the singular values squared of the matrix product formed from inverse standard Gaussian matrices, and standard Gaussian matrices, is shown to satisfy a variant of the algebraic equation relating to the Raney distribution. Supported on , we show that it too permits a simple functional form upon the introduction of an appropriate choice of parameterization. As an application, the leading asymptotic form of the density as the endpoints of the support are approached is computed, and is shown to have some universal features.

  13. CALL FOR PAPERS: Special issue on the random search problem: trends and perspectives

    Science.gov (United States)

    da Luz, Marcos G. E.; Grosberg, Alexander Y.; Raposo, Ernesto P.; Viswanathan, Gandhi M.

    2008-11-01

    This is a call for contributions to a special issue of Journal of Physics A: Mathematical and Theoretical dedicated to the subject of the random search problem. The motivation behind this special issue is to summarize in a single comprehensive publication, the main aspects (past and present), latest developments, different viewpoints and the directions being followed in this multidisciplinary field. We hope that such a special issue could become a particularly valuable reference for the broad scientific community working with the general random search problem. The Editorial Board has invited Marcos G E da Luz, Alexander Y Grosberg, Ernesto P Raposo and Gandhi M Viswanathan to serve as Guest Editors for the special issue. The general question of how to optimize the search for specific target objects in either continuous or discrete environments when the information available is limited is of significant importance in a broad range of fields. Representative examples include ecology (animal foraging, dispersion of populations), geology (oil recovery from mature reservoirs), information theory (automated researchers of registers in high-capacity database), molecular biology (proteins searching for their sites, e.g., on DNA ), etc. One reason underlying the richness of the random search problem relates to the `ignorance' of the locations of the randomly located `targets'. A statistical approach to the search problem can deal adequately with incomplete information and so stochastic strategies become advantageous. The general problem of how to search efficiently for randomly located target sites can thus be quantitatively described using the concepts and methods of statistical physics and stochastic processes. Scope Thus far, to the best of our knowledge, no recent textbook or review article in a physics journal has appeared on this topic. This makes a special issue with review and research articles attractive to those interested in acquiring a general introduction to the

  14. Solving the wind farm layout optimization problem using random search algorithm

    DEFF Research Database (Denmark)

    Feng, Ju; Shen, Wen Zhong

    2015-01-01

    , in which better results than the genetic algorithm (GA) and the old version of the RS algorithm are obtained. Second it is applied to the Horns Rev 1 WF, and the optimized layouts obtain a higher power production than its original layout, both for the real scenario and for two constructed scenarios......Wind farm (WF) layout optimization is to find the optimal positions of wind turbines (WTs) inside a WF, so as to maximize and/or minimize a single objective or multiple objectives, while satisfying certain constraints. In this work, a random search (RS) algorithm based on continuous formulation....... In this application, it is also found that in order to get consistent and reliable optimization results, up to 360 or more sectors for wind direction have to be used. Finally, considering the inevitable inter-annual variations in the wind conditions, the robustness of the optimized layouts against wind condition...

  15. Encouraging GPs to undertake screening and a brief intervention in order to reduce problem drinking: a randomized controlled trial

    DEFF Research Database (Denmark)

    Hansen, Lars Jørgen; Olivarius, Niels de Fine; Beich, Anders

    1999-01-01

    intervention, problem drinking, randomized controlled trial, family practice, marketing of health services......intervention, problem drinking, randomized controlled trial, family practice, marketing of health services...

  16. SpecSatisfiabilityTool: A tool for testing the satisfiability of specifications on XML documents

    Directory of Open Access Journals (Sweden)

    Javier Albors

    2015-01-01

    Full Text Available We present a prototype that implements a set of logical rules to prove the satisfiability for a class of specifications on XML documents. Specifications are given by means of constrains built on Boolean XPath patterns. The main goal of this tool is to test whether a given specification is satisfiable or not, and justify the decision showing the execution history. It can also be used to test whether a given document is a model of a given specification and, as a by-product, it permits to look for all the relations (monomorphisms between two patterns and to combine patterns in different ways. The results of these operations are visually shown and therefore the tool makes these operations more understandable. The implementation of the algorithm has been written in Prolog but the prototype has a Java interface for an easy and friendly use. In this paper we show how to use this interface in order to test all the desired properties.

  17. Random isotropic one-dimensional XY-model

    Science.gov (United States)

    Gonçalves, L. L.; Vieira, A. P.

    1998-01-01

    The 1D isotropic s = ½XY-model ( N sites), with random exchange interaction in a transverse random field is considered. The random variables satisfy bimodal quenched distributions. The solution is obtained by using the Jordan-Wigner fermionization and a canonical transformation, reducing the problem to diagonalizing an N × N matrix, corresponding to a system of N noninteracting fermions. The calculations are performed numerically for N = 1000, and the field-induced magnetization at T = 0 is obtained by averaging the results for the different samples. For the dilute case, in the uniform field limit, the magnetization exhibits various discontinuities, which are the consequence of the existence of disconnected finite clusters distributed along the chain. Also in this limit, for finite exchange constants J A and J B, as the probability of J A varies from one to zero, the saturation field is seen to vary from Γ A to Γ B, where Γ A(Γ B) is the value of the saturation field for the pure case with exchange constant equal to J A(J B) .

  18. Randomized Controlled Trial of Problem-Solving Therapy for Minor Depression in Home Care

    Science.gov (United States)

    Gellis, Zvi D.; McGinty, Jean; Tierney, Lynda; Jordan, Cindy; Burton, Jean; Misener, Elizabeth

    2008-01-01

    Objective: Data are presented from a pilot research program initiated to develop, refine, and test the outcomes of problem-solving therapy that targets the needs of older adults with minor depression in home care settings. Method: A pilot randomized clinical trial compares the impact of problem-solving therapy for home care to treatment as usual…

  19. Satisfying pedagogical practices using ICT

    NARCIS (Netherlands)

    Voogt, Joke; Law, N.; Pelgrum, W.J.; Plomp, T.

    2008-01-01

    This chapter describes the results of the international option that was included in SITES 2006. The international option, which was part of the teacher questionnaire, solicited responses from teachers on satisfying experiences in their pedagogical use of ICT. Twenty-one of the participating

  20. The viability of neural network for modeling the impact of individual job satisfiers on work commitment in Indian manufacturing unit

    Directory of Open Access Journals (Sweden)

    Therasa Chandrasekar

    2015-10-01

    Full Text Available This paper provides an exposition about application of neural networks in the context of research to find out the contribution of individual job satisfiers towards work commitment. The purpose of the current study is to build a predictive model to estimate the normalized importance of individual job satisfiers towards work commitment of employees working in TVS Group, an Indian automobile company. The study is based on the tool developed by Spector (1985 and Sue Hayday (2003.The input variable of the study consists of nine independent individual job satisfiers which includes Pay, Promotion, Supervision, Benefits, Rewards, Operating procedures, Co-workers, Work-itself and Communication of Spector (1985 and dependent variable as work commitment of Sue Hayday (2003.The primary data has been collected using a closed-ended questionnaire based on simple random sampling approach. This study employed the multilayer Perceptron neural network model to envisage the level of job satisfiers towards work commitment. The result from the multilayer Perceptron neural network model displayed with four hidden layer with correct classification rate of 70% and 30% for training and testing data set. The normalized importance shows high value for coworkers, superior satisfaction and communication and which acts as most significant attributes of job satisfiers that predicts the overall work commitment of employees.

  1. The cross-cultural importance of satisfying vital needs.

    Science.gov (United States)

    Alvarez, Allen Andrew A

    2009-11-01

    Ethical beliefs may vary across cultures but there are things that must be valued as preconditions to any cultural practice. Physical and mental abilities vital to believing, valuing and practising a culture are such preconditions and it is always important to protect them. If one is to practise a distinct culture, she must at least have these basic abilities. Access to basic healthcare is one way to ensure that vital abilities are protected. John Rawls argued that access to all-purpose primary goods must be ensured. Amartya Sen and Martha Nussbaum claim that universal capabilities are what resources are meant to enable. Len Doyal and Ian Gough identify physical health and autonomy as basic needs of every person in every culture. When we disagree on what to prioritize, when resources to satisfy competing demands are scarce, our common needs can provide a point of normative convergence. Need-based rationing, however, has been criticized for being too indeterminate to give guidance for deciding which healthcare services to prioritize and for tending to create a bottomless-pit problem. But there is a difference between needing something (first-order need) and needing to have the ability to need (second-order need). Even if we disagree about which first-order need to prioritize, we must accept the importance of satisfying our second-order need to have the ability to value things. We all have a second-order need for basic healthcare as a means to protect our vital abilities even if we differ in what our cultures consider to be particular first-order needs.

  2. Random matrix analysis of the QCD sign problem for general topology

    International Nuclear Information System (INIS)

    Bloch, Jacques; Wettig, Tilo

    2009-01-01

    Motivated by the important role played by the phase of the fermion determinant in the investigation of the sign problem in lattice QCD at nonzero baryon density, we derive an analytical formula for the average phase factor of the fermion determinant for general topology in the microscopic limit of chiral random matrix theory at nonzero chemical potential, for both the quenched and the unquenched case. The formula is a nontrivial extension of the expression for zero topology derived earlier by Splittorff and Verbaarschot. Our analytical predictions are verified by detailed numerical random matrix simulations of the quenched theory.

  3. Satisfiability of logic programming based on radial basis function neural networks

    International Nuclear Information System (INIS)

    Hamadneh, Nawaf; Sathasivam, Saratha; Tilahun, Surafel Luleseged; Choon, Ong Hong

    2014-01-01

    In this paper, we propose a new technique to test the Satisfiability of propositional logic programming and quantified Boolean formula problem in radial basis function neural networks. For this purpose, we built radial basis function neural networks to represent the proportional logic which has exactly three variables in each clause. We used the Prey-predator algorithm to calculate the output weights of the neural networks, while the K-means clustering algorithm is used to determine the hidden parameters (the centers and the widths). Mean of the sum squared error function is used to measure the activity of the two algorithms. We applied the developed technique with the recurrent radial basis function neural networks to represent the quantified Boolean formulas. The new technique can be applied to solve many applications such as electronic circuits and NP-complete problems

  4. Satisfiability of logic programming based on radial basis function neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Hamadneh, Nawaf; Sathasivam, Saratha; Tilahun, Surafel Luleseged; Choon, Ong Hong [School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

    2014-07-10

    In this paper, we propose a new technique to test the Satisfiability of propositional logic programming and quantified Boolean formula problem in radial basis function neural networks. For this purpose, we built radial basis function neural networks to represent the proportional logic which has exactly three variables in each clause. We used the Prey-predator algorithm to calculate the output weights of the neural networks, while the K-means clustering algorithm is used to determine the hidden parameters (the centers and the widths). Mean of the sum squared error function is used to measure the activity of the two algorithms. We applied the developed technique with the recurrent radial basis function neural networks to represent the quantified Boolean formulas. The new technique can be applied to solve many applications such as electronic circuits and NP-complete problems.

  5. Satisfiability of ATL with strategy contexts

    Directory of Open Access Journals (Sweden)

    François Laroussinie

    2013-07-01

    Full Text Available Various extensions of the temporal logic ATL have recently been introduced to express rich properties of multi-agent systems. Among these, ATLsc extends ATL with strategy contexts, while Strategy Logic has first-order quantification over strategies. There is a price to pay for the rich expressiveness of these logics: model-checking is non-elementary, and satisfiability is undecidable. We prove in this paper that satisfiability is decidable in several special cases. The most important one is when restricting to turn-based games. We prove that decidability also holds for concurrent games if the number of moves available to the agents is bounded. Finally, we prove that restricting strategy quantification to memoryless strategies brings back undecidability.

  6. Statistical mechanics of the fashion game on random networks

    International Nuclear Information System (INIS)

    Sun, YiFan

    2016-01-01

    A model of fashion on networks is studied. This model consists of two groups of agents that are located on a network and have opposite viewpoints towards being fashionable: behaving consistently with either the majority or the minority of adjacent agents. Checking whether the fashion game has a pure Nash equilibrium (pure NE) is a non-deterministic polynomial complete problem. Using replica-symmetric mean field theory, the largest proportion of satisfied agents and the region where at least one pure NE should exist are determined for several types of random networks. Furthermore, a quantitive analysis of the asynchronous best response dynamics yields the phase diagram of existence and detectability of pure NE in the fashion game on some random networks. (paper: classical statistical mechanics, equilibrium and non-equilibrium).

  7. Term Satisfiability in FLew-Algebras

    Czech Academy of Sciences Publication Activity Database

    Haniková, Zuzana; Savický, Petr

    2016-01-01

    Roč. 631, 6 June (2016), s. 1-15 ISSN 0304-3975 R&D Projects: GA ČR GBP202/12/G061 Institutional support: RVO:67985807 Keywords : substructural logic * FLew-algebra * MV-algebra * satisfiability * computational complexity Subject RIV: BA - General Mathematics Impact factor: 0.698, year: 2016

  8. Comparison of the effectiveness of three manual physical therapy techniques in a subgroup of patients with low back pain who satisfy a clinical prediction rule: Study protocol of a randomized clinical trial [NCT00257998

    Directory of Open Access Journals (Sweden)

    Childs John D

    2006-02-01

    Full Text Available Abstract Background Recently a clinical prediction rule (CPR has been developed and validated that accurately identifies patients with low back pain (LBP that are likely to benefit from a lumbo-pelvic thrust manipulation. The studies that developed and validated the rule used the identical manipulation procedure. However, recent evidence suggests that different manual therapy techniques may result similar outcomes. The purpose of this study is to investigate the effectiveness of three different manual therapy techniques in a subgroup of patient with low back pain that satisfy the CPR. Methods/Design Consecutive patients with LBP referred to physical therapy clinics in one of four geographical locations who satisfy the CPR will be invited to participate in this randomized clinical trial. Subjects who agree to participate will undergo a standard evaluation and complete a number of patient self-report questionnaires including the Oswestry Disability Index (OSW, which will serve as the primary outcome measure. Following the baseline examination patients will be randomly assigned to receive the lumbopelvic manipulation used in the development of the CPR, an alternative lumbar manipulation technique, or non-thrust lumbar mobilization technique for the first 2 visits. Beginning on visit 3, all 3 groups will receive an identical standard exercise program for 3 visits (visits 3,4,5. Outcomes of interest will be captured by a therapist blind to group assignment at 1 week (3rd visit, 4 weeks (6th visit and at a 6-month follow-up. The primary aim of the study will be tested with analysis of variance (ANOVA using the change in OSW score from baseline to 4-weeks (OSWBaseline – OSW4-weeks as the dependent variable. The independent variable will be treatment with three levels (lumbo-pelvic manipulation, alternative lumbar manipulation, lumbar mobilization. Discussion This trial will be the first to investigate the effectiveness of various manual therapy

  9. Hierarchical Solution of the Traveling Salesman Problem with Random Dyadic Tilings

    Science.gov (United States)

    Kalmár-Nagy, Tamás; Bak, Bendegúz Dezső

    We propose a hierarchical heuristic approach for solving the Traveling Salesman Problem (TSP) in the unit square. The points are partitioned with a random dyadic tiling and clusters are formed by the points located in the same tile. Each cluster is represented by its geometrical barycenter and a “coarse” TSP solution is calculated for these barycenters. Midpoints are placed at the middle of each edge in the coarse solution. Near-optimal (or optimal) minimum tours are computed for each cluster. The tours are concatenated using the midpoints yielding a solution for the original TSP. The method is tested on random TSPs (independent, identically distributed points in the unit square) up to 10,000 points as well as on a popular benchmark problem (att532 — coordinates of 532 American cities). Our solutions are 8-13% longer than the optimal ones. We also present an optimization algorithm for the partitioning to improve our solutions. This algorithm further reduces the solution errors (by several percent using 1000 iteration steps). The numerical experiments demonstrate the viability of the approach.

  10. Adaptive sampling method in deep-penetration particle transport problem

    International Nuclear Information System (INIS)

    Wang Ruihong; Ji Zhicheng; Pei Lucheng

    2012-01-01

    Deep-penetration problem has been one of the difficult problems in shielding calculation with Monte Carlo method for several decades. In this paper, a kind of particle transport random walking system under the emission point as a sampling station is built. Then, an adaptive sampling scheme is derived for better solution with the achieved information. The main advantage of the adaptive scheme is to choose the most suitable sampling number from the emission point station to obtain the minimum value of the total cost in the process of the random walk. Further, the related importance sampling method is introduced. Its main principle is to define the importance function due to the particle state and to ensure the sampling number of the emission particle is proportional to the importance function. The numerical results show that the adaptive scheme under the emission point as a station could overcome the difficulty of underestimation of the result in some degree, and the adaptive importance sampling method gets satisfied results as well. (authors)

  11. Effects of PMTO in foster families with children with behavior problems : A Randomized Controlled Trial

    NARCIS (Netherlands)

    Maaskant, A.M.; van Rooij, F.B.; Overbeek, G.J.; Oort, F.J.; Arntz, M.; Hermanns, J.M.A.

    The present randomized controlled trial examined the effectiveness of Parent Management Training Oregon for foster parents with foster children (aged 4–12) with severe externalizing behavior problems in long-term foster care arrangements. Foster children’s behavior problems are challenging for

  12. Convolutions of Heavy Tailed Random Variables and Applications to Portfolio Diversification and MA(1) Time Series

    OpenAIRE

    Geluk, Jaap; Peng, Liang; de Vries, Casper G.

    1999-01-01

    Suppose X1,X2 are independent random variables satisfying a second-order regular variation condition on the tail-sum and a balance condition on the tails. In this paper we give a description of the asymptotic behaviour as t → ∞ for P(X1 + X2 > t). The result is applied to the problem of risk diversification in portfolio analysis and to the estimation of the parameter in a MA(1) model.

  13. Quantum random number generator

    Science.gov (United States)

    Soubusta, Jan; Haderka, Ondrej; Hendrych, Martin

    2001-03-01

    Since reflection or transmission of a quantum particle on a beamsplitter is inherently random quantum process, a device built on this principle does not suffer from drawbacks of neither pseudo-random computer generators or classical noise sources. Nevertheless, a number of physical conditions necessary for high quality random numbers generation must be satisfied. Luckily, in quantum optics realization they can be well controlled. We present an easy random number generator based on the division of weak light pulses on a beamsplitter. The randomness of the generated bit stream is supported by passing the data through series of 15 statistical test. The device generates at a rate of 109.7 kbit/s.

  14. Intermittent random walks: transport regimes and implications on search strategies

    International Nuclear Information System (INIS)

    Gomez Portillo, Ignacio; Campos, Daniel; Méndez, Vicenç

    2011-01-01

    We construct a transport model for particles that alternate rests of random duration and flights with random velocities. The model provides a balance equation for the mesoscopic particle density obtained from the continuous-time random walk framework. By assuming power laws for the distributions of waiting times and flight durations (for any velocity distribution with finite moments) we have found that the model can yield all the transport regimes ranging from subdiffusion to ballistic depending on the values of the characteristic exponents of the distributions. In addition, if the exponents satisfy a simple relationship it is shown how the competition between the tails of the distributions gives rise to a diffusive transport. Finally, we explore how the details of this intermittent transport process affect the success probability in an optimal search problem where an individual searcher looks for a target distributed (heterogeneously) in space. All the results are conveniently checked with numerical simulations

  15. A randomized controlled trial of a personalized feedback intervention for problem gamblers.

    Directory of Open Access Journals (Sweden)

    John A Cunningham

    Full Text Available Personalized feedback is a promising self-help for problem gamblers. Such interventions have shown consistently positive results with other addictive behaviours, and our own pilot test of personalized normative feedback materials for gamblers yielded positive findings. The current randomized controlled trial evaluated the effectiveness, and the sustained efficacy, of the personalized feedback intervention materials for problem gamblers.Respondents recruited by a general population telephone screener of Ontario adults included gamblers with moderate and severe gambling problems. Those who agreed to participate were randomly assigned to receive: 1 the full personalized normative feedback intervention; 2 a partial feedback that contained all the feedback information provided to those in condition 1 but without the normative feedback content (i.e., no comparisons provided to general population gambling norms; or 3 a waiting list control condition. The primary hypothesis was that problem gamblers who received the personalized normative feedback intervention would reduce their gambling more than problem gamblers who did not receive any intervention (waiting list control condition by the six-month follow-up.The study found no evidence for the impact of normative personalized feedback. However, participants who received, the partial feedback (without norms reduced the number of days they gambled compared to participants who did not receive the intervention. We concluded that personalized feedback interventions were well received and the materials may be helpful at reducing gambling. Realistically, it can be expected that the personalized feedback intervention may have a limited, short term impact on the severity of participants' problem gambling because the intervention is just a brief screener. An Internet-based version of the personalized feedback intervention tool, however, may offer an easy to access and non-threatening portal that can be used to

  16. A parallel attractor-finding algorithm based on Boolean satisfiability for genetic regulatory networks.

    Directory of Open Access Journals (Sweden)

    Wensheng Guo

    Full Text Available In biological systems, the dynamic analysis method has gained increasing attention in the past decade. The Boolean network is the most common model of a genetic regulatory network. The interactions of activation and inhibition in the genetic regulatory network are modeled as a set of functions of the Boolean network, while the state transitions in the Boolean network reflect the dynamic property of a genetic regulatory network. A difficult problem for state transition analysis is the finding of attractors. In this paper, we modeled the genetic regulatory network as a Boolean network and proposed a solving algorithm to tackle the attractor finding problem. In the proposed algorithm, we partitioned the Boolean network into several blocks consisting of the strongly connected components according to their gradients, and defined the connection between blocks as decision node. Based on the solutions calculated on the decision nodes and using a satisfiability solving algorithm, we identified the attractors in the state transition graph of each block. The proposed algorithm is benchmarked on a variety of genetic regulatory networks. Compared with existing algorithms, it achieved similar performance on small test cases, and outperformed it on larger and more complex ones, which happens to be the trend of the modern genetic regulatory network. Furthermore, while the existing satisfiability-based algorithms cannot be parallelized due to their inherent algorithm design, the proposed algorithm exhibits a good scalability on parallel computing architectures.

  17. Bell inequalities for random fields

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, Peter [Physics Department, Yale University, CT 06520 (United States)

    2006-06-09

    The assumptions required for the derivation of Bell inequalities are not satisfied for random field models in which there are any thermal or quantum fluctuations, in contrast to the general satisfaction of the assumptions for classical two point particle models. Classical random field models that explicitly include the effects of quantum fluctuations on measurement are possible for experiments that violate Bell inequalities.

  18. Bell inequalities for random fields

    OpenAIRE

    Morgan, Peter

    2004-01-01

    The assumptions required for the derivation of Bell inequalities are not usually satisfied for random fields in which there are any thermal or quantum fluctuations, in contrast to the general satisfaction of the assumptions for classical two point particle models. Classical random field models that explicitly include the effects of quantum fluctuations on measurement are possible for experiments that violate Bell inequalities.

  19. Analysis of students’ creative thinking level in problem solving based on national council of teachers of mathematics

    Science.gov (United States)

    Hobri; Suharto; Rifqi Naja, Ahmad

    2018-04-01

    This research aims to determine students’ creative thinking level in problem solving based on NCTM in function subject. The research type is descriptive with qualitative approach. Data collection methods which were used are test and interview. Creative thinking level in problem solving based on NCTM indicators consists of (1) Make mathematical model from a contextual problem and solve the problem, (2) Solve problem using various possible alternatives, (3) Find new alternative(s) to solve the problem, (4) Determine the most efficient and effective alternative for that problem, (5) Review and correct mistake(s) on the process of problem solving. Result of the research showed that 10 students categorized in very satisfying level, 23 students categorized in satisfying level and 1 students categorized in less satisfying level. Students in very satisfying level meet all indicators, students in satisfying level meet first, second, fourth, and fifth indicator, while students in less satisfying level only meet first and fifth indicator.

  20. Solving SAT Problem Based on Hybrid Differential Evolution Algorithm

    Science.gov (United States)

    Liu, Kunqi; Zhang, Jingmin; Liu, Gang; Kang, Lishan

    Satisfiability (SAT) problem is an NP-complete problem. Based on the analysis about it, SAT problem is translated equally into an optimization problem on the minimum of objective function. A hybrid differential evolution algorithm is proposed to solve the Satisfiability problem. It makes full use of strong local search capacity of hill-climbing algorithm and strong global search capability of differential evolution algorithm, which makes up their disadvantages, improves the efficiency of algorithm and avoids the stagnation phenomenon. The experiment results show that the hybrid algorithm is efficient in solving SAT problem.

  1. Unified heuristics to solve routing problem of reverse logistics in sustainable supply chain

    Science.gov (United States)

    Anbuudayasankar, S. P.; Ganesh, K.; Lenny Koh, S. C.; Mohandas, K.

    2010-03-01

    A reverse logistics problem, motivated by many real-life applications, is examined where bottles/cans in which products are delivered from a processing depot to customers in one period are available for return to the depot in the following period. The picked-up bottles/cans need to be adjusted in the place of delivery load. This problem is termed as simultaneous delivery and pick-up problem with constrained capacity (SDPC). We develop three unified heuristics based on extended branch and bound heuristic, genetic algorithm and simulated annealing to solve SDPC. These heuristics are also designed to solve standard travelling salesman problem (TSP) and TSP with simultaneous delivery and pick-up (TSDP). We tested the heuristics on standard, derived and randomly generated datasets of TSP, TSDP and SDPC and obtained satisfying results with high convergence in reasonable time.

  2. Problems of variance reduction in the simulation of random variables

    International Nuclear Information System (INIS)

    Lessi, O.

    1987-01-01

    The definition of the uniform linear generator is given and some of the mostly used tests to evaluate the uniformity and the independence of the obtained determinations are listed. The problem of calculating, through simulation, some moment W of a random variable function is taken into account. The Monte Carlo method enables the moment W to be estimated and the estimator variance to be obtained. Some techniques for the construction of other estimators of W with a reduced variance are introduced

  3. Random number generators in support of Monte Carlo problems in physics

    International Nuclear Information System (INIS)

    Dyadkin, I.G.

    1993-01-01

    The ability to support a modern users' expectations of random number generators to solve problems in physics is analyzed. The capabilities of the newest concepts and the old pseudo-random algorithms are compared. The author is in favor of multiplicative generators. Due to the 64-bit arithmetic of a modern PC, multiplicative generators have a sufficient number of periods (up to 2 62 ) and are quicker to generate and to govern independent sequences for parallel processing. In addition they are able to replicate sub-sequences (without storing their seeds) for each standard trial in any code and to simulate spatial and planar directions and EXP(-x) distributions often needed as ''bricks'' for simulating events in physics. Hundreds of multipliers for multiplicative generators have been tabulated and tested, and the required speeds have been obtained. (author)

  4. Are underground coal miners satisfied with their work boots?

    Science.gov (United States)

    Dobson, Jessica A; Riddiford-Harland, Diane L; Bell, Alison F; Steele, Julie R

    2018-01-01

    Dissatisfaction with work boot design is common in the mining industry. Many underground coal miners believe their work boots contribute to the high incidence of lower limb injuries they experience. Despite this, the most recent research to examine underground coal mining work boot satisfaction was conducted over a decade ago. This present study aimed to address this gap in the literature by assessing current mining work boot satisfaction in relation to the work-related requirements for underground coal mining. 358 underground coal miners (355 men; mean age = 39.1 ± 10.7 years) completed a 54-question survey regarding their job details, work footwear habits, foot problems, lower limb and lower back pain history, and work footwear fit and comfort. Results revealed that underground coal miners were not satisfied with their current mining work boots. This was evident in the high incidence of reported foot problems (55.3%), lower back pain (44.5%), knee pain (21.5%), ankle pain (24.9%) and foot pain (42.3%). Over half of the underground coal miners surveyed believed their work boots contributed to their lower limb pain and reported their work boots were uncomfortable. Different working roles and environments resulted in differences in the incidence of foot problems, lower limb pain and comfort scores, confirming that one boot design cannot meet all the work-related requirements of underground coal mining. Further research examining the interaction of a variety of boot designs across the different underground surfaces and the different tasks miners perform is paramount to identify key boot design features that affect the way underground coal miners perform. Enhanced work boot design could improve worker comfort and productivity by reducing the high rates of reported foot problems and pain amongst underground coal miners. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Evaluation of random temperature fluctuation problems with frequency response approach

    International Nuclear Information System (INIS)

    Lejeail, Yves; Kasahara, Naoto

    2000-01-01

    Since thermal striping is a coupled thermohydraulic and thermomechanical phenomenon, sodium mock-up tests were usually required to confirm structural integrity. Authors have developed the frequency response function to establish design-by-analysis methodology for this phenomenon. Applicability of this method to sinusoidal fluctuation was validated through two benchmark problems with FAENA and TIFFSS facilities under EJCC contract. This report describes the extension of the frequency response method to random fluctuations. As an example of application, fatigue strength of a Tee junction of PHENIX secondary piping system was investigated. (author)

  6. Adding randomness controlling parameters in GRASP method applied in school timetabling problem

    Directory of Open Access Journals (Sweden)

    Renato Santos Pereira

    2017-09-01

    Full Text Available This paper studies the influence of randomness controlling parameters (RCP in first stage GRASP method applied in graph coloring problem, specifically school timetabling problems in a public high school. The algorithm (with the inclusion of RCP was based on critical variables identified through focus groups, whose weights can be adjusted by the user in order to meet the institutional needs. The results of the computational experiment, with 11-year-old data (66 observations processed at the same high school show that the inclusion of RCP leads to significantly lowering the distance between initial solutions and local minima. The acceptance and the use of the solutions found allow us to conclude that the modified GRASP, as has been constructed, can make a positive contribution to this timetabling problem of the school in question.

  7. Fuzzy Random λ-Mean SAD Portfolio Selection Problem: An Ant Colony Optimization Approach

    Science.gov (United States)

    Thakur, Gour Sundar Mitra; Bhattacharyya, Rupak; Mitra, Swapan Kumar

    2010-10-01

    To reach the investment goal, one has to select a combination of securities among different portfolios containing large number of securities. Only the past records of each security do not guarantee the future return. As there are many uncertain factors which directly or indirectly influence the stock market and there are also some newer stock markets which do not have enough historical data, experts' expectation and experience must be combined with the past records to generate an effective portfolio selection model. In this paper the return of security is assumed to be Fuzzy Random Variable Set (FRVS), where returns are set of random numbers which are in turn fuzzy numbers. A new λ-Mean Semi Absolute Deviation (λ-MSAD) portfolio selection model is developed. The subjective opinions of the investors to the rate of returns of each security are taken into consideration by introducing a pessimistic-optimistic parameter vector λ. λ-Mean Semi Absolute Deviation (λ-MSAD) model is preferred as it follows absolute deviation of the rate of returns of a portfolio instead of the variance as the measure of the risk. As this model can be reduced to Linear Programming Problem (LPP) it can be solved much faster than quadratic programming problems. Ant Colony Optimization (ACO) is used for solving the portfolio selection problem. ACO is a paradigm for designing meta-heuristic algorithms for combinatorial optimization problem. Data from BSE is used for illustration.

  8. Total variation regularization of the 3-D gravity inverse problem using a randomized generalized singular value decomposition

    Science.gov (United States)

    Vatankhah, Saeed; Renaut, Rosemary A.; Ardestani, Vahid E.

    2018-04-01

    We present a fast algorithm for the total variation regularization of the 3-D gravity inverse problem. Through imposition of the total variation regularization, subsurface structures presenting with sharp discontinuities are preserved better than when using a conventional minimum-structure inversion. The associated problem formulation for the regularization is nonlinear but can be solved using an iteratively reweighted least-squares algorithm. For small-scale problems the regularized least-squares problem at each iteration can be solved using the generalized singular value decomposition. This is not feasible for large-scale, or even moderate-scale, problems. Instead we introduce the use of a randomized generalized singular value decomposition in order to reduce the dimensions of the problem and provide an effective and efficient solution technique. For further efficiency an alternating direction algorithm is used to implement the total variation weighting operator within the iteratively reweighted least-squares algorithm. Presented results for synthetic examples demonstrate that the novel randomized decomposition provides good accuracy for reduced computational and memory demands as compared to use of classical approaches.

  9. ARE AUTHENTIC LEADERS SATISFIED WITH THEIR JOB?

    Directory of Open Access Journals (Sweden)

    Nebojsa Pavlovic

    2016-06-01

    Full Text Available A crisis in management has led to the appearance of Authentic leadership. The aim of this work is to determine the characteristics of Authentic leadership in educational institutions and to respond to the question as to whether authentic leaders are satisfied with their job. The third aim is to determine differences among the researched regions. The sample included 227 randomly selected directors from primary and secondary schools in Serbia, Montenegro and the Republika Srpska. The research used an ALQ questionnaire for the estimation of leadership behaviour. Descriptions for the results prediction and multiple linear regressions were used. A multivariance analysis of variance was used to compare the groups. The research results showed that every fourth director is an authentic leader. Authentic leadership has a significant influence on job satisfaction through two aspects: internalised perspective and balanced processing. There are no differences in Authentic leadership in the researched areas. The results could be useful for educational institutions in countries where the research was conducted. Further research could be carried out in other countries while cultural differences should be taken into account. One limiting factor consists of the fact that the analysed data are obtained only from school directors. Leaders of educational institutions should provide management through the development of their own authenticity and the authenticity of their followers. The characteristics of Authentic leadership were reviewed and tested practically in the West-Balkan environment.

  10. A nuclear reload optimization approach using a real coded genetic algorithm with random keys

    International Nuclear Information System (INIS)

    Lima, Alan M.M. de; Schirru, Roberto; Medeiros, Jose A.C.C.

    2009-01-01

    The fuel reload of a Pressurized Water Reactor is made whenever the burn up of the fuel assemblies in the nucleus of the reactor reaches a certain value such that it is not more possible to maintain a critical reactor producing energy at nominal power. The problem of fuel reload optimization consists on determining the positioning of the fuel assemblies within the nucleus of the reactor in an optimized way to minimize the cost benefit relationship of fuel assemblies cost per maximum burn up, and also satisfying symmetry and safety restrictions. The fuel reload optimization problem difficulty grows exponentially with the number of fuel assemblies in the nucleus of the reactor. During decades the fuel reload optimization problem was solved manually by experts that used their knowledge and experience to build configurations of the reactor nucleus, and testing them to verify if safety restrictions of the plant are satisfied. To reduce this burden, several optimization techniques have been used, included the binary code genetic algorithm. In this work we show the use of a real valued coded approach of the genetic algorithm, with different recombination methods, together with a transformation mechanism called random keys, to transform the real values of the genes of each chromosome in a combination of discrete fuel assemblies for evaluation of the reload optimization. Four different recombination methods were tested: discrete recombination, intermediate recombination, linear recombination and extended linear recombination. For each of the 4 recombination methods 10 different tests using different seeds for the random number generator were conducted 10 generating, totaling 40 tests. The results of the application of the genetic algorithm are shown with formulation of real numbers for the problem of the nuclear reload of the plant Angra 1 type PWR. Since the best results in the literature for this problem were found by the parallel PSO we will it use for comparison

  11. An Artificial Bee Colony Algorithm for the Job Shop Scheduling Problem with Random Processing Times

    Directory of Open Access Journals (Sweden)

    Rui Zhang

    2011-09-01

    Full Text Available Due to the influence of unpredictable random events, the processing time of each operation should be treated as random variables if we aim at a robust production schedule. However, compared with the extensive research on the deterministic model, the stochastic job shop scheduling problem (SJSSP has not received sufficient attention. In this paper, we propose an artificial bee colony (ABC algorithm for SJSSP with the objective of minimizing the maximum lateness (which is an index of service quality. First, we propose a performance estimate for preliminary screening of the candidate solutions. Then, the K-armed bandit model is utilized for reducing the computational burden in the exact evaluation (through Monte Carlo simulation process. Finally, the computational results on different-scale test problems validate the effectiveness and efficiency of the proposed approach.

  12. Model correction factor method for reliability problems involving integrals of non-Gaussian random fields

    DEFF Research Database (Denmark)

    Franchin, P.; Ditlevsen, Ove Dalager; Kiureghian, Armen Der

    2002-01-01

    The model correction factor method (MCFM) is used in conjunction with the first-order reliability method (FORM) to solve structural reliability problems involving integrals of non-Gaussian random fields. The approach replaces the limit-state function with an idealized one, in which the integrals ...

  13. Random eigenvalue problems revisited

    Indian Academy of Sciences (India)

    statistical distributions; linear stochastic systems. 1. ... dimensional multivariate Gaussian random vector with mean µ ∈ Rm and covariance ... 5, the proposed analytical methods are applied to a three degree-of-freedom system and the ...... The joint pdf ofω1 andω3 is however close to a bivariate Gaussian density function.

  14. An Optimization Approach for Hazardous Waste Management Problem under Stochastic Programming

    International Nuclear Information System (INIS)

    Abass, S.A.; Abdallah, A.S.; Gomaa, M.A.

    2008-01-01

    Hazardous waste is the waste which, due to their nature and quantity, is potentially hazardous to human health and/or the environment. This kind of waste requires special disposal techniques to eliminate or reduce thc hazardous. Hazardous waste management (HWM) problem is concerned in the basic with the disposal method. hi this paper we focus on incineration as an effective to dispose the waste. For this type of disposal, there arc air pollution standards imposed by the government. We will propose an optimization model satisfied the air pollution standards and based on the model of Emek and Kara with using random variable coefficients in the constraint

  15. Level of satisfaction of older persons with their general practitioner and practice: role of complexity of health problems.

    Science.gov (United States)

    Poot, Antonius J; den Elzen, Wendy P J; Blom, Jeanet W; Gussekloo, Jacobijn

    2014-01-01

    Satisfaction is widely used to evaluate and direct delivery of medical care; a complicated relationship exists between patient satisfaction, morbidity and age. This study investigates the relationships between complexity of health problems and level of patient satisfaction of older persons with their general practitioner (GP) and practice. This study is embedded in the ISCOPE (Integrated Systematic Care for Older Persons) study. Enlisted patients aged ≥75 years from 59 practices received a written questionnaire to screen for complex health problems (somatic, functional, psychological and social). For 2664 randomly chosen respondents (median age 82 years; 68% female) information was collected on level of satisfaction (satisfied, neutral, dissatisfied) with their GP and general practice, and demographic and clinical characteristics including complexity of health problems. Of all participants, 4% was dissatisfied with their GP care, 59% neutral and 37% satisfied. Between these three categories no differences were observed in age, gender, country of birth or education level. The percentage of participants dissatisfied with their GP care increased from 0.4% in those with 0 problem domains to 8% in those with 4 domains, i.e. having complex health problems (ppatient characteristic influencing the perception of care, or whether the care is unable to handle the demands of these patients. Prospective studies are needed to investigate the causal associations between care organization, patient characteristics, indicators of quality, and patient perceptions.

  16. Decision Engines for Software Analysis Using Satisfiability Modulo Theories Solvers

    Science.gov (United States)

    Bjorner, Nikolaj

    2010-01-01

    The area of software analysis, testing and verification is now undergoing a revolution thanks to the use of automated and scalable support for logical methods. A well-recognized premise is that at the core of software analysis engines is invariably a component using logical formulas for describing states and transformations between system states. The process of using this information for discovering and checking program properties (including such important properties as safety and security) amounts to automatic theorem proving. In particular, theorem provers that directly support common software constructs offer a compelling basis. Such provers are commonly called satisfiability modulo theories (SMT) solvers. Z3 is a state-of-the-art SMT solver. It is developed at Microsoft Research. It can be used to check the satisfiability of logical formulas over one or more theories such as arithmetic, bit-vectors, lists, records and arrays. The talk describes some of the technology behind modern SMT solvers, including the solver Z3. Z3 is currently mainly targeted at solving problems that arise in software analysis and verification. It has been applied to various contexts, such as systems for dynamic symbolic simulation (Pex, SAGE, Vigilante), for program verification and extended static checking (Spec#/Boggie, VCC, HAVOC), for software model checking (Yogi, SLAM), model-based design (FORMULA), security protocol code (F7), program run-time analysis and invariant generation (VS3). We will describe how it integrates support for a variety of theories that arise naturally in the context of the applications. There are several new promising avenues and the talk will touch on some of these and the challenges related to SMT solvers. Proceedings

  17. Measurement problem in PROGRAM UNIVERSE

    International Nuclear Information System (INIS)

    Noyes, H.P.; Gefwert, C.

    1984-12-01

    We present a discrete theory that meets the measurement problem in a new way. We generate a growing universe of bit strings, labeled by 2 127 + 136 strings organized by some representation of the closed, four level, combinatorial hierarchy, of bit-length N 139 greater than or equal to 139. The rest of the strings for each label, which grow in both length and number, are called addresses. The generating algorithm, called PROGRAM UNIVERSE, starts from a random choice between the two symbols ''0'' and ''1'' and grows (a) by discriminating between two randomly chosen strings and adjoining a novel result to the universe, or when the string so generated is not novel, by (b) adjoining a randomly chosen bit at the growing end of each string. We obtain, by appropriate definitions and interpretations, stable ''particles'' which satisfy the usual relativistic kinematics and quantized angular momentum without being localizable in a continuum space-time. The labeling scheme is congruent with the ''standard model'' of quarks and leptons with three generations, but for the problem at hand, the implementation of this aspect of the theory is unimportant. What matters most is that (a) these complicated ''particles'' have the periodicities familiar from relativistic ''deBroglie waves'' and resolve in a discrete way the ''wave-particle dualism'' and (b) can be ''touched'' by our discrete equivalent of ''soft photons'' in such a way as to follow, macroscopically, the usual Rutherford scattering trajectories with the associated bound states. Thus our theory could provide a discrete description of ''measurement'' in a way that allows no conceptual barrier between the ''micro'' and the ''macro'' worlds, if we are willing to base our physics on counting and exclude the ambiguities associated with the unobservable ''continuum''. 27 refs

  18. Interference-aware random beam selection for spectrum sharing systems

    KAUST Repository

    Abdallah, Mohamed M.

    2012-09-01

    Spectrum sharing systems have been introduced to alleviate the problem of spectrum scarcity by allowing secondary unlicensed networks to share the spectrum with primary licensed networks under acceptable interference levels to the primary users. In this paper, we develop interference-aware random beam selection schemes that provide enhanced throughput for the secondary link under the condition that the interference observed at the primary link is within a predetermined acceptable value. For a secondary transmitter equipped with multiple antennas, our schemes select a random beam, among a set of power- optimized orthogonal random beams, that maximizes the capacity of the secondary link while satisfying the interference constraint at the primary receiver for different levels of feedback information describing the interference level at the primary receiver. For the proposed schemes, we develop a statistical analysis for the signal-to-noise and interference ratio (SINR) statistics as well as the capacity of the secondary link. Finally, we present numerical results that study the effect of system parameters including number of beams and the maximum transmission power on the capacity of the secondary link attained using the proposed schemes. © 2012 IEEE.

  19. Random walks on reductive groups

    CERN Document Server

    Benoist, Yves

    2016-01-01

    The classical theory of Random Walks describes the asymptotic behavior of sums of independent identically distributed random real variables. This book explains the generalization of this theory to products of independent identically distributed random matrices with real coefficients. Under the assumption that the action of the matrices is semisimple – or, equivalently, that the Zariski closure of the group generated by these matrices is reductive - and under suitable moment assumptions, it is shown that the norm of the products of such random matrices satisfies a number of classical probabilistic laws. This book includes necessary background on the theory of reductive algebraic groups, probability theory and operator theory, thereby providing a modern introduction to the topic.

  20. An Improved Distribution Policy with a Maintenance Aspect for an Urban Logistic Problem

    Directory of Open Access Journals (Sweden)

    Nadia Ndhaief

    2017-07-01

    Full Text Available In this paper, we present an improved distribution plan supporting an urban distribution center (UDC to solve the last mile problem of urban freight. This is motivated by the need of UDCs to satisfy daily demand in time under a high service level in allocated urban areas. Moreover, these demands could not be satisfied in individual cases because the delivery rate can be less than daily demand and/or affected by random failure or maintenance actions of vehicles. The scope of our work is to focus on a UDC, which needs to satisfy demands in a finite horizon. To that end, we consider a distribution policy on two sequential plans, a distribution plan correlated to a maintenance plan using a subcontracting strategy with several potential urban distribution centers (UDCs and performing preventive maintenance to ensure deliveries for their allocated urban area. The choice of subcontractor will depend on distance, environmental and availability criteria. In doing so, we define a mathematical model for searching the best distribution and maintenance plans using a subcontracting strategy. Moreover, we consider delay for the next periods with an expensive penalty. Finally, we present a numerical example illustrating the benefits of our approach.

  1. Modified truncated randomized singular value decomposition (MTRSVD) algorithms for large scale discrete ill-posed problems with general-form regularization

    Science.gov (United States)

    Jia, Zhongxiao; Yang, Yanfei

    2018-05-01

    In this paper, we propose new randomization based algorithms for large scale linear discrete ill-posed problems with general-form regularization: subject to , where L is a regularization matrix. Our algorithms are inspired by the modified truncated singular value decomposition (MTSVD) method, which suits only for small to medium scale problems, and randomized SVD (RSVD) algorithms that generate good low rank approximations to A. We use rank-k truncated randomized SVD (TRSVD) approximations to A by truncating the rank- RSVD approximations to A, where q is an oversampling parameter. The resulting algorithms are called modified TRSVD (MTRSVD) methods. At every step, we use the LSQR algorithm to solve the resulting inner least squares problem, which is proved to become better conditioned as k increases so that LSQR converges faster. We present sharp bounds for the approximation accuracy of the RSVDs and TRSVDs for severely, moderately and mildly ill-posed problems, and substantially improve a known basic bound for TRSVD approximations. We prove how to choose the stopping tolerance for LSQR in order to guarantee that the computed and exact best regularized solutions have the same accuracy. Numerical experiments illustrate that the best regularized solutions by MTRSVD are as accurate as the ones by the truncated generalized singular value decomposition (TGSVD) algorithm, and at least as accurate as those by some existing truncated randomized generalized singular value decomposition (TRGSVD) algorithms. This work was supported in part by the National Science Foundation of China (Nos. 11771249 and 11371219).

  2. EMDR versus CBT for children with self-esteem and behavioral problems: a randomized controlled trial

    NARCIS (Netherlands)

    Wanders, F.; Serra, M.; de Jongh, A.

    2008-01-01

    This study compared eye movement desensitization and reprocessing (EMDR) with cognitive-behavioral therapy (CBT). Twenty-six children (average age 10.4 years) with behavioral problems were randomly assigned to receive either 4 sessions of EMDR or CBT prior to usual treatment provided in outpatient

  3. A Location-Inventory-Routing Problem in Forward and Reverse Logistics Network Design

    Directory of Open Access Journals (Sweden)

    Qunli Yuchi

    2016-01-01

    Full Text Available We study a new problem of location-inventory-routing in forward and reverse logistic (LIRP-FRL network design, which simultaneously integrates the location decisions of distribution centers (DCs, the inventory policies of opened DCs, and the vehicle routing decision in serving customers, in which new goods are produced and damaged goods are repaired by a manufacturer and then returned to the market to satisfy customers’ demands as new ones. Our objective is to minimize the total costs of manufacturing and remanufacturing goods, building DCs, shipping goods (new or recovered between the manufacturer and opened DCs, and distributing new or recovered goods to customers and ordering and storage costs of goods. A nonlinear integer programming model is proposed to formulate the LIRP-FRL. A new tabu search (NTS algorithm is developed to achieve near optimal solution of the problem. Numerical experiments on the benchmark instances of a simplified version of the LIRP-FRL, the capacitated location routing problem, and the randomly generated LIRP-FRL instances demonstrate the effectiveness and efficiency of the proposed NTS algorithm in problem resolution.

  4. Social problem solving in carers of young people with a first episode of psychosis: a randomized controlled trial.

    Science.gov (United States)

    McCann, Terence V; Cotton, Sue M; Lubman, Dan I

    2017-08-01

    Caring for young people with first-episode psychosis is difficult and demanding, and has detrimental effects on carers' well-being, with few evidence-based resources available to assist carers to deal with the problems they are confronted with in this situation. We aimed to examine if completion of a self-directed problem-solving bibliotherapy by first-time carers of young people with first-episode psychosis improved their social problem solving compared with carers who only received treatment as usual. A randomized controlled trial was carried out through two early intervention psychosis services in Melbourne, Australia. A sample of 124 carers were randomized to problem-solving bibliotherapy or treatment as usual. Participants were assessed at baseline, 6- and 16-week follow-up. Intent-to-treat analyses were used and showed that recipients of bibliotherapy had greater social problem-solving abilities than those receiving treatment as usual, and these effects were maintained at both follow-up time points. Our findings affirm that bibliotherapy, as a low-cost complement to treatment as usual for carers, had some effects in improving their problem-solving skills when addressing problems related to the care and support of young people with first-episode psychosis. © 2015 The Authors. Early Intervention in Psychiatry published by Wiley Publishing Asia Pty Ltd.

  5. Partially satisfied to fully satisfied transitions in co-evolving inverse voter model and possible scaling behavior

    International Nuclear Information System (INIS)

    Choi, C.W.; Xu, C.; Hui, P.M.

    2015-01-01

    Understanding co-evolving networks characterized by the mutual influence of agents' actions and network structure remains a challenge. We study a co-evolving inverse voter model in which agents adapt to achieve a preferred environment with more opposite-opinion neighbors by rewiring their connections and switching opinion. Numerical studies reveal a transition from a dynamic partially satisfied phase to a frozen fully satisfied phase as the rewiring probability is varied. A simple mean field theory is shown to capture the behavior only qualitatively. An improved mean field theory carrying a longer spatial correlation gives better results. Motivated by numerical results in networks of different degrees and mean field results, we propose a scaling variable that combines the rewiring probability and mean degree in a special form. The scaling variable is shown to work well in analyzing data corresponding to different networks and different rewiring probabilities. An application is to predict the results for networks of different degrees based solely on results obtained from networks of one degree. Studying scaling behavior provides an alternative path for understanding co-evolving agent-based dynamical systems, especially in light of the trade-off between complexity of a theory and its accuracy. - Highlights: • Identified key features and phase transitions in coevolving inverse voter model. • Constructed a better theory incorporating longer spatial correlation. • Proposed scaling variable and illustrated possible scaling behavior. • Used scaling behavior to predict results of IVM in a different network.

  6. Routing and scheduling problems

    DEFF Research Database (Denmark)

    Reinhardt, Line Blander

    couple of decades. To deliver competitive service and price, transportation today needs to be cost effective. A company requiring for things to be shipped will aim at having the freight shipped as cheaply as possible while often satisfying certain time constraints. For the transportation company......, the effectiveness of the network is of importance aiming at satisfying as many costumer demands as possible at a low cost. Routing represent a path between locations such as an origin and destination for the object routed. Sometimes routing has a time dimension as well as the physical paths. This may...... set cost making the cost of the individual vehicle routes inter-dependant. Depending on the problem type, the size of the problems and time available for solving, different solution methods can be applicable. In this thesis both heuristic methods and several exact methods are investigated depending...

  7. The Development of an Internet-Based Treatment for Problem Gamblers and Concerned Significant Others: A Pilot Randomized Controlled Trial.

    Science.gov (United States)

    Nilsson, Anders; Magnusson, Kristoffer; Carlbring, Per; Andersson, Gerhard; Gumpert, Clara Hellner

    2018-06-01

    Problem gambling creates significant harm for the gambler and for concerned significant others (CSOs). While several studies have investigated the effects of individual cognitive behavioral therapy (CBT) for problem gambling, less is known about the effects of involving CSOs in treatment. Behavioral couples therapy (BCT) has shown promising results when working with substance use disorders by involving both the user and a CSO. This pilot study investigated BCT for problem gambling, as well as the feasibility of performing a larger scale randomized controlled trial. 36 participants, 18 gamblers and 18 CSOs, were randomized to either BCT or individual CBT for the gambler. Both interventions were Internet-delivered self-help interventions with therapist support. Both groups of gamblers improved on all outcome measures, but there were no differences between the groups. The CSOs in the BCT group lowered their scores on anxiety and depression more than the CSOs of those randomized to the individual CBT group did. The implications of the results and the feasibility of the trial are discussed.

  8. Randomized and quantum algorithms for solving initial-value problems in ordinary differential equations of order k

    Directory of Open Access Journals (Sweden)

    Maciej Goćwin

    2008-01-01

    Full Text Available The complexity of initial-value problems is well studied for systems of equations of first order. In this paper, we study the \\(\\varepsilon\\-complexity for initial-value problems for scalar equations of higher order. We consider two models of computation, the randomized model and the quantum model. We construct almost optimal algorithms adjusted to scalar equations of higher order, without passing to systems of first order equations. The analysis of these algorithms allows us to establish upper complexity bounds. We also show (almost matching lower complexity bounds. The \\(\\varepsilon\\-complexity in the randomized and quantum setting depends on the regularity of the right-hand side function, but is independent of the order of equation. Comparing the obtained bounds with results known in the deterministic case, we see that randomized algorithms give us a speed-up by \\(1/2\\, and quantum algorithms by \\(1\\ in the exponent. Hence, the speed-up does not depend on the order of equation, and is the same as for the systems of equations of first order. We also include results of some numerical experiments which confirm theoretical results.

  9. Branding and Positioning to Satisfy the Customer's Appetite: An Educational Case Study

    Science.gov (United States)

    Ham, Tim

    2010-01-01

    Rebranding and positioning a school district has become critical to satisfy the "customer's" appetite, enhance public relations, and advance consumer perceptions. A service design model provides a district with the framework to advance its position by identifying attributes and prompts to satisfy customer needs and increase student…

  10. Explaining sex differences in managerial career satisfier preferences: the role of gender self-schema.

    Science.gov (United States)

    Eddleston, Kimberly A; Veiga, John F; Powell, Gary N

    2006-03-01

    Using survey data from 400 managers, the authors examined whether gender self-schema would explain sex differences in preferences for status-based and socioemotional career satisfiers. Female gender self-schema, represented by femininity and family role salience, completely mediated the relationship between managers' sex and preferences for socioemotional career satisfiers. However, male gender self-schema, represented by masculinity and career role salience, did not mediate the relationship between managers' sex and preferences for status-based career satisfiers. As expected, male managers regarded status-based career satisfiers as more important and socioemotional career satisfiers as less important than female managers did. The proposed conceptualization of male and female gender self-schemas, which was supported by the data, enhances understanding of adult self-schema and work-related attitudes and behavior.

  11. Ising formulations of many NP problems

    OpenAIRE

    Lucas, Andrew

    2013-01-01

    We provide Ising formulations for many NP-complete and NP-hard problems, including all of Karp's 21 NP-complete problems. This collects and extends mappings to the Ising model from partitioning, covering and satisfiability. In each case, the required number of spins is at most cubic in the size of the problem. This work may be useful in designing adiabatic quantum optimization algorithms.

  12. Satisfying the demand for financial information in public traded companies

    DEFF Research Database (Denmark)

    Holm, Claus

    A public traded company which wishes to comply with IAS standards and stock exchange requirements for full public disclosure of relevant information faces a major communication task. The Investor Relation policy of such a company has to satisfy a demand for financial information which seems...... line focus to the disclosure of cash flow surrogates like EBITA and EBITDA. Overall, the findings suggest a communication strategy intended to satisfy the demand from the professional analysts. However, the shear number of different key figures and financial ratios identified in the study suggest...

  13. Anatomy of Alternating Quantifier Satisfiability (Work in progress)

    DEFF Research Database (Denmark)

    Dung, Phan Anh; Bjørner, Nikolaj; Monniaux, David

    We report on work in progress to generalize an algorithm recently introduced in [10] for checking satisfiability of formulas with quantifier alternation. The algorithm uses two auxiliary procedures: a procedure for producing a candidate formula for quantifier elimination and a procedure for elimi...

  14. The art of problem posing

    CERN Document Server

    Brown, Stephen I

    1990-01-01

    Updated and expanded, this second edition satisfies the same philosophical objective as the first -- to show the importance of problem posing. Although interest in mathematical problem solving increased during the past decade, problem posing remained relatively ignored. The Art of Problem Posing draws attention to this equally important act and is the innovator in the field. Special features include: * an exploration ofthe logical relationship between problem posing and problem solving * a special chapter devoted to teaching problem posing as a separate course * sketches, drawings, diagrams, and cartoons that illustrate the schemes proposed * a special section on writing in mathematics.

  15. Variational structure of inverse problems in wave propagation and vibration

    Energy Technology Data Exchange (ETDEWEB)

    Berryman, J.G.

    1995-03-01

    Practical algorithms for solving realistic inverse problems may often be viewed as problems in nonlinear programming with the data serving as constraints. Such problems are most easily analyzed when it is possible to segment the solution space into regions that are feasible (satisfying all the known constraints) and infeasible (violating some of the constraints). Then, if the feasible set is convex or at least compact, the solution to the problem will normally lie on the boundary of the feasible set. A nonlinear program may seek the solution by systematically exploring the boundary while satisfying progressively more constraints. Examples of inverse problems in wave propagation (traveltime tomography) and vibration (modal analysis) will be presented to illustrate how the variational structure of these problems may be used to create nonlinear programs using implicit variational constraints.

  16. Continuous grasp algorithm applied to economic dispatch problem of thermal units

    Energy Technology Data Exchange (ETDEWEB)

    Vianna Neto, Julio Xavier [Pontifical Catholic University of Parana - PUCPR, Curitiba, PR (Brazil). Undergraduate Program at Mechatronics Engineering; Bernert, Diego Luis de Andrade; Coelho, Leandro dos Santos [Pontifical Catholic University of Parana - PUCPR, Curitiba, PR (Brazil). Industrial and Systems Engineering Graduate Program, LAS/PPGEPS], e-mail: leandro.coelho@pucpr.br

    2010-07-01

    The economic dispatch problem (EDP) is one of the fundamental issues in power systems to obtain benefits with the stability, reliability and security. Its objective is to allocate the power demand among committed generators in the most economical manner, while all physical and operational constraints are satisfied. The cost of power generation, particularly in fossil fuel plants, is very high and economic dispatch helps in saving a significant amount of revenue. Recently, as an alternative to the conventional mathematical approaches, modern heuristic optimization techniques such as simulated annealing, evolutionary algorithms, neural networks, ant colony, and tabu search have been given much attention by many researchers due to their ability to find an almost global optimal solution in EDPs. On other hand, continuous GRASP (C-GRASP) is a stochastic local search meta-heuristic for finding cost-efficient solutions to continuous global optimization problems subject to box constraints. Like a greedy randomized adaptive search procedure (GRASP), a C-GRASP is a multi-start procedure where a starting solution for local improvement is constructed in a greedy randomized fashion. The C-GRASP algorithm is validated for a test system consisting of fifteen units, test system that takes into account spinning reserve and prohibited operating zones constrains. (author)

  17. Ising formulations of many NP problems

    Directory of Open Access Journals (Sweden)

    Andrew eLucas

    2014-02-01

    Full Text Available We provide Ising formulations for many NP-complete and NP-hard problems, including all of Karp's 21 NP-complete problems. This collects and extends mappings to the Ising model from partitioning, covering and satisfiability. In each case, the required number of spins is at most cubic in the size of the problem. This work may be useful in designing adiabatic quantum optimization algorithms.

  18. Online Problem Solving for Adolescent Brain Injury: A Randomized Trial of 2 Approaches.

    Science.gov (United States)

    Wade, Shari L; Taylor, Hudson Gerry; Yeates, Keith Owen; Kirkwood, Michael; Zang, Huaiyu; McNally, Kelly; Stacin, Terry; Zhang, Nanhua

    Adolescent traumatic brain injury (TBI) contributes to deficits in executive functioning and behavior, but few evidence-based treatments exist. We conducted a randomized clinical trial comparing Teen Online Problem Solving with Family (TOPS-Family) with Teen Online Problem Solving with Teen Only (TOPS-TO) or the access to Internet Resources Comparison (IRC) group. Children, aged 11 to 18 years, who sustained a complicated mild-to-severe TBI in the previous 18 months were randomly assigned to the TOPS-Family (49), TOPS-TO (51), or IRC group (52). Parent and self-report measures of externalizing behaviors and executive functioning were completed before treatment and 6 months later. Treatment effects were examined using linear regression models, adjusting for baseline symptom levels. Age, maternal education, and family stresses were examined as moderators. The TOPS-Family group had lower levels of parent-reported executive dysfunction at follow-up than the TOPS-TO group, and differences between the TOPS-Family and IRC groups approached significance. Maternal education moderated improvements in parent-reported externalizing behaviors, with less educated parents in the TOPS-Family group reporting fewer symptoms. On the self-report Behavior Rating Inventory of Executive Functions, treatment efficacy varied with the level of parental stresses. The TOPS-Family group reported greater improvements at low stress levels, whereas the TOPS-TO group reported greater improvement at high-stress levels. The TOPS-TO group did not have significantly lower symptoms than the IRC group on any comparison. Findings support the efficacy of online family problem solving to address executive dysfunction and improve externalizing behaviors among youth with TBI from less advantaged households. Treatment with the teen alone may be indicated in high-stress families.

  19. Efficacy of an internet-based problem-solving training for teachers: results of a randomized controlled trial

    NARCIS (Netherlands)

    Ebert, D.D.; Lehr, D.; BoB, L.; Riper, H.; Cuijpers, P.; Andersson, G.; Thiart, H.; Heber, E.; Berking, M.

    2014-01-01

    Objective The primary purpose of this randomized controlled trial (RCT) was to evaluate the efficacy of internet-based problem-solving training (iPST) for employees in the educational sector (teachers) with depressive symptoms. The results of training were compared to those of a waitlist control

  20. Fractional Stochastic Differential Equations Satisfying Fluctuation-Dissipation Theorem

    Science.gov (United States)

    Li, Lei; Liu, Jian-Guo; Lu, Jianfeng

    2017-10-01

    We propose in this work a fractional stochastic differential equation (FSDE) model consistent with the over-damped limit of the generalized Langevin equation model. As a result of the `fluctuation-dissipation theorem', the differential equations driven by fractional Brownian noise to model memory effects should be paired with Caputo derivatives, and this FSDE model should be understood in an integral form. We establish the existence of strong solutions for such equations and discuss the ergodicity and convergence to Gibbs measure. In the linear forcing regime, we show rigorously the algebraic convergence to Gibbs measure when the `fluctuation-dissipation theorem' is satisfied, and this verifies that satisfying `fluctuation-dissipation theorem' indeed leads to the correct physical behavior. We further discuss possible approaches to analyze the ergodicity and convergence to Gibbs measure in the nonlinear forcing regime, while leave the rigorous analysis for future works. The FSDE model proposed is suitable for systems in contact with heat bath with power-law kernel and subdiffusion behaviors.

  1. Producing Satisfactory Solutions to Scheduling Problems: An Iterative Constraint Relaxation Approach

    Science.gov (United States)

    Chien, S.; Gratch, J.

    1994-01-01

    One drawback to using constraint-propagation in planning and scheduling systems is that when a problem has an unsatisfiable set of constraints such algorithms typically only show that no solution exists. While, technically correct, in practical situations, it is desirable in these cases to produce a satisficing solution that satisfies the most important constraints (typically defined in terms of maximizing a utility function). This paper describes an iterative constraint relaxation approach in which the scheduler uses heuristics to progressively relax problem constraints until the problem becomes satisfiable. We present empirical results of applying these techniques to the problem of scheduling spacecraft communications for JPL/NASA antenna resources.

  2. The Prevention Program for Externalizing Problem Behavior (PEP) Improves Child Behavior by Reducing Negative Parenting: Analysis of Mediating Processes in a Randomized Controlled Trial

    Science.gov (United States)

    Hanisch, Charlotte; Hautmann, Christopher; Plück, Julia; Eichelberger, Ilka; Döpfner, Manfred

    2014-01-01

    Background: Our indicated Prevention program for preschool children with Externalizing Problem behavior (PEP) demonstrated improved parenting and child problem behavior in a randomized controlled efficacy trial and in a study with an effectiveness design. The aim of the present analysis of data from the randomized controlled trial was to identify…

  3. Particle swarm optimization with random keys applied to the nuclear reactor reload problem

    Energy Technology Data Exchange (ETDEWEB)

    Meneses, Anderson Alvarenga de Moura [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear; Fundacao Educacional de Macae (FUNEMAC), RJ (Brazil). Faculdade Professor Miguel Angelo da Silva Santos; Machado, Marcelo Dornellas; Medeiros, Jose Antonio Carlos Canedo; Schirru, Roberto [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear]. E-mails: ameneses@con.ufrj.br; marcelo@lmp.ufrj.br; canedo@lmp.ufrj.br; schirru@lmp.ufrj.br

    2007-07-01

    In 1995, Kennedy and Eberhart presented the Particle Swarm Optimization (PSO), an Artificial Intelligence metaheuristic technique to optimize non-linear continuous functions. The concept of Swarm Intelligence is based on the socials aspects of intelligence, it means, the ability of individuals to learn with their own experience in a group as well as to take advantage of the performance of other individuals. Some PSO models for discrete search spaces have been developed for combinatorial optimization, although none of them presented satisfactory results to optimize a combinatorial problem as the nuclear reactor fuel reloading problem (NRFRP). In this sense, we developed the Particle Swarm Optimization with Random Keys (PSORK) in previous research to solve Combinatorial Problems. Experiences demonstrated that PSORK performed comparable to or better than other techniques. Thus, PSORK metaheuristic is being applied in optimization studies of the NRFRP for Angra 1 Nuclear Power Plant. Results will be compared with Genetic Algorithms and the manual method provided by a specialist. In this experience, the problem is being modeled for an eight-core symmetry and three-dimensional geometry, aiming at the minimization of the Nuclear Enthalpy Power Peaking Factor as well as the maximization of the cycle length. (author)

  4. Particle swarm optimization with random keys applied to the nuclear reactor reload problem

    International Nuclear Information System (INIS)

    Meneses, Anderson Alvarenga de Moura; Fundacao Educacional de Macae; Machado, Marcelo Dornellas; Medeiros, Jose Antonio Carlos Canedo; Schirru, Roberto

    2007-01-01

    In 1995, Kennedy and Eberhart presented the Particle Swarm Optimization (PSO), an Artificial Intelligence metaheuristic technique to optimize non-linear continuous functions. The concept of Swarm Intelligence is based on the socials aspects of intelligence, it means, the ability of individuals to learn with their own experience in a group as well as to take advantage of the performance of other individuals. Some PSO models for discrete search spaces have been developed for combinatorial optimization, although none of them presented satisfactory results to optimize a combinatorial problem as the nuclear reactor fuel reloading problem (NRFRP). In this sense, we developed the Particle Swarm Optimization with Random Keys (PSORK) in previous research to solve Combinatorial Problems. Experiences demonstrated that PSORK performed comparable to or better than other techniques. Thus, PSORK metaheuristic is being applied in optimization studies of the NRFRP for Angra 1 Nuclear Power Plant. Results will be compared with Genetic Algorithms and the manual method provided by a specialist. In this experience, the problem is being modeled for an eight-core symmetry and three-dimensional geometry, aiming at the minimization of the Nuclear Enthalpy Power Peaking Factor as well as the maximization of the cycle length. (author)

  5. Correlated random walks induced by dynamical wavefunction collapse

    Science.gov (United States)

    Bedingham, Daniel

    2015-03-01

    Wavefunction collapse models modify Schrödinger's equation so that it describes the collapse of a superposition of macroscopically distinguishable states as a genuine physical process [PRA 42, 78 (1990)]. This provides a basis for the resolution of the quantum measurement problem. An additional generic consequence of the collapse mechanism is that it causes particles to exhibit a tiny random diffusive motion. Furthermore, the diffusions of two sufficiently nearby particles are positively correlated -- it is more likely that the particles diffuse in the same direction than would happen if they behaved independently [PRA 89, 032713 (2014)]. The use of this effect is proposed as an experimental test of wave function collapse models in which pairs of nanoparticles are simultaneously released from nearby traps and allowed a brief period of free fall. The random displacements of the particles are then measured. The experiment must be carried out at sufficiently low temperature and pressure for the collapse effects to dominate over the ambient environmental noise. It is argued that these constraints can be satisfied by current technologies for a large class of viable wavefunction collapse models. Work supported by the Templeton World Charity Foundation.

  6. Two solvable problems of planar geometrical optics.

    Science.gov (United States)

    Borghero, Francesco; Bozis, George

    2006-12-01

    In the framework of geometrical optics we consider a two-dimensional transparent inhomogeneous isotropic medium (dispersive or not). We show that (i) for any family belonging to a certain class of planar monoparametric families of monochromatic light rays given in the form f(x,y)=c of any definite color and satisfying a differential condition, all the refractive index profiles n=n(x,y) allowing for the creation of the given family can be found analytically (inverse problem) and that (ii) for any member of a class of two-dimensional refractive index profiles n=n(x,y) satisfying a differential condition, all the compatible families of light rays can be found analytically (direct problem). We present appropriate examples.

  7. Australian primary health care nurses most and least satisfying aspects of work.

    Science.gov (United States)

    Halcomb, Elizabeth; Ashley, Christine

    2017-02-01

    To identify the aspects of working in Australian primary health care that nurses rate as the most and least satisfying. The nursing workforce in Australian primary health care has grown exponentially to meet the growing demand for health care. To maintain and further growth requires the recruitment and retention of nurses to this setting. Understanding the factors that nurses' rate as the most and least satisfying about their job will inform strategies to enhance nurse retention. A cross-sectional online survey. Nurses employed in primary health care settings across Australia were recruited (n = 1166) to participate in a survey which combined items related to the respondent, their job, type of work, clinical activities, job satisfaction and future intention, with two open-ended items about the most and least satisfying aspects of their work. Patient interactions, respect, teamwork, collegiality and autonomy were identified as the most satisfying professional aspects of their role. Personal considerations such as family friendly work arrangements and a satisfactory work-life balance were also important, overriding negative components of the role. The least satisfying aspects were poor financial support and remuneration, lack of a career path, physical work environment and time constraints. National restructuring of the primary health care environment was seen as a barrier to role stability and ability to work to a full scope of practice. This study has identified a range of positive and negative professional and personal aspects of the primary health care nursing role, which may impact on staff recruitment and retention. Findings from the study should be considered by employers seeking to retain and maximise the skills of their primary health care workforce. Understanding the factors that nurses perceive as being the most and least satisfying aspects of the work is can open up dialogue about how to improve the working experience of nurses in primary health care.

  8. Effectiveness of telephone-assisted parent-administered behavioural family intervention for preschool children with externalizing problem behaviour: a randomized controlled trial.

    Science.gov (United States)

    Kierfeld, Frauke; Ise, Elena; Hanisch, Charlotte; Görtz-Dorten, Anja; Döpfner, Manfred

    2013-09-01

    Externalizing problem behaviour is one of the most common childhood disorders. Parent training is an effective treatment for these children and there is growing interest in the effects of parent-administered interventions with minimal therapist contact. This randomized controlled study examined the efficacy of a telephone-assisted parent-administered behavioural intervention (bibliotherapy) in families with preschool children with externalizing problem behaviour. Families were randomly assigned to a treatment group (n = 26) and an untreated waitlist control group (n = 22). The intervention comprised the reading of an 11 chapter self-help book and 11 weekly telephone consultations. Compared to the control group, the treatment group demonstrated significant decreases in parent-reported externalizing and internalizing child problem behaviour and dysfunctional parenting practices. Moreover, treated parents reported less parenting-related strains and decreases in parental depression, anxiety, and stress. The results suggest that telephone-assisted self-administered parent training is an effective alternative to more intensive forms of behavioural family intervention for preschool children with externalizing problem behaviour.

  9. Random matrices and random difference equations

    International Nuclear Information System (INIS)

    Uppuluri, V.R.R.

    1975-01-01

    Mathematical models leading to products of random matrices and random difference equations are discussed. A one-compartment model with random behavior is introduced, and it is shown how the average concentration in the discrete time model converges to the exponential function. This is of relevance to understanding how radioactivity gets trapped in bone structure in blood--bone systems. The ideas are then generalized to two-compartment models and mammillary systems, where products of random matrices appear in a natural way. The appearance of products of random matrices in applications in demography and control theory is considered. Then random sequences motivated from the following problems are studied: constant pulsing and random decay models, random pulsing and constant decay models, and random pulsing and random decay models

  10. Development strategies to satisfy corporate average CO_2 emission regulations of light duty vehicles (LDVs) in Korea

    International Nuclear Information System (INIS)

    Oh, Yunjung; Park, Junhong; Lee, Jong Tae; Seo, Jigu; Park, Sungwook

    2016-01-01

    In the present study, we generated vehicle dynamic based light-duty vehicle (LDV) models and investigated some technical strategies in order to meet the corporate average CO_2 emission (CACE) regulations of Korea, which will be applied from 2016 to 2020. Seven types of LDV simulation models (including gasoline, diesel, and hybrid cars) were generated based on the AVL CRUISE program and the LDV sales ratio was used to estimate the CACE value of five companies in Korea. The prediction accuracy of the LDV models was validated using chassis dynamometer test data. Then, the effectiveness of the CACE reduction strategies was investigated based on the developed LDV simulation models. From the results of this study, it was revealed that all of the companies cannot satisfy the 2020 CACE regulation by just adopting a single strategy. In order to solve this problem, two types of CACE plans that combined several strategies (reducing the mass drag and fuel consumption rate, and adding a hybrid module, etc.) were proposed. After implementing the two types of CACE plan, it was predicted that five companies will be able to satisfy the 2020 CACE regulation. - Highlights: • Seven types of LDV models were generated to predict CO_2 emission. • Five companies were selected as the major car makers in Korea. • Diverse of strategies were considered to meet the future CO_2 standards in Korea. • All of the companies cannot satisfy the 2020 regulation by adopting a single item. • Two types of plans that combined several strategies were proposed.

  11. Obstacle mean-field game problem

    KAUST Repository

    Gomes, Diogo A.; Patrizi, Stefania

    2015-01-01

    In this paper, we introduce and study a first-order mean-field game obstacle problem. We examine the case of local dependence on the measure under assumptions that include both the logarithmic case and power-like nonlinearities. Since the obstacle operator is not differentiable, the equations for first-order mean field game problems have to be discussed carefully. Hence, we begin by considering a penalized problem. We prove this problem admits a unique solution satisfying uniform bounds. These bounds serve to pass to the limit in the penalized problem and to characterize the limiting equations. Finally, we prove uniqueness of solutions. © European Mathematical Society 2015.

  12. Does horizon entropy satisfy a quantum null energy conjecture?

    Science.gov (United States)

    Fu, Zicao; Marolf, Donald

    2016-12-01

    A modern version of the idea that the area of event horizons gives 4G times an entropy is the Hubeny-Rangamani causal holographic information (CHI) proposal for holographic field theories. Given a region R of a holographic QFTs, CHI computes A/4G on a certain cut of an event horizon in the gravitational dual. The result is naturally interpreted as a coarse-grained entropy for the QFT. CHI is known to be finitely greater than the fine-grained Hubeny-Rangamani-Takayanagi (HRT) entropy when \\partial R lies on a Killing horizon of the QFT spacetime, and in this context satisfies other non-trivial properties expected of an entropy. Here we present evidence that it also satisfies the quantum null energy condition (QNEC), which bounds the second derivative of the entropy of a quantum field theory on one side of a non-expanding null surface by the flux of stress-energy across the surface. In particular, we show CHI to satisfy the QNEC in 1  +  1 holographic CFTs when evaluated in states dual to conical defects in AdS3. This surprising result further supports the idea that CHI defines a useful notion of coarse-grained holographic entropy, and suggests unprecedented bounds on the rate at which bulk horizon generators emerge from a caustic. To supplement our motivation, we include an appendix deriving a corresponding coarse-grained generalized second law for 1  +  1 holographic CFTs perturbatively coupled to dilaton gravity.

  13. Can Targeted Intervention Mitigate Early Emotional and Behavioral Problems?: Generating Robust Evidence within Randomized Controlled Trials.

    Directory of Open Access Journals (Sweden)

    Orla Doyle

    Full Text Available This study examined the impact of a targeted Irish early intervention program on children's emotional and behavioral development using multiple methods to test the robustness of the results. Data on 164 Preparing for Life participants who were randomly assigned into an intervention group, involving home visits from pregnancy onwards, or a control group, was used to test the impact of the intervention on Child Behavior Checklist scores at 24-months. Using inverse probability weighting to account for differential attrition, permutation testing to address small sample size, and quantile regression to characterize the distributional impact of the intervention, we found that the few treatment effects were largely concentrated among boys most at risk of developing emotional and behavioral problems. The average treatment effect identified a 13% reduction in the likelihood of falling into the borderline clinical threshold for Total Problems. The interaction and subgroup analysis found that this main effect was driven by boys. The distributional analysis identified a 10-point reduction in the Externalizing Problems score for boys at the 90th percentile. No effects were observed for girls or for the continuous measures of Total, Internalizing, and Externalizing problems. These findings suggest that the impact of this prenatally commencing home visiting program may be limited to boys experiencing the most difficulties. Further adoption of the statistical methods applied here may help to improve the internal validity of randomized controlled trials and contribute to the field of evaluation science more generally.ISRCTN Registry ISRCTN04631728.

  14. Emotion Regulation Enhancement of Cognitive Behavior Therapy for College Student Problem Drinkers: A Pilot Randomized Controlled Trial

    Science.gov (United States)

    Ford, Julian D.; Grasso, Damion J.; Levine, Joan; Tennen, Howard

    2018-01-01

    This pilot randomized clinical trial tested an emotion regulation enhancement to cognitive behavior therapy (CBT) with 29 college student problem drinkers with histories of complex trauma and current clinically significant traumatic stress symptoms. Participants received eight face-to-face sessions of manualized Internet-supported CBT for problem…

  15. Quantum random number generation for loophole-free Bell tests

    Science.gov (United States)

    Mitchell, Morgan; Abellan, Carlos; Amaya, Waldimar

    2015-05-01

    We describe the generation of quantum random numbers at multi-Gbps rates, combined with real-time randomness extraction, to give very high purity random numbers based on quantum events at most tens of ns in the past. The system satisfies the stringent requirements of quantum non-locality tests that aim to close the timing loophole. We describe the generation mechanism using spontaneous-emission-driven phase diffusion in a semiconductor laser, digitization, and extraction by parity calculation using multi-GHz logic chips. We pay special attention to experimental proof of the quality of the random numbers and analysis of the randomness extraction. In contrast to widely-used models of randomness generators in the computer science literature, we argue that randomness generation by spontaneous emission can be extracted from a single source.

  16. [Problem-solving strategies and marital satisfaction].

    Science.gov (United States)

    Kriegelewicz, Olga

    2006-01-01

    This study investigated the relation between problem-solving strategies in the marital conflict and marital satisfaction. Four problem-solving strategies (Dialogue, Loyalty, Escalation of conflict and Withdrawal) were measured by the Problem-Solving Strategies Inventory, in two versions: self-report and report of partners' perceived behaviour. This measure refers to the concept of Rusbult, Johnson and Morrow, and meets high standards of reliability (alpha Cronbach from alpha = 0.78 to alpha = 0.94) and validity. Marital satisfaction was measured by Marriage Success Scale. The sample was composed of 147 marital couples. The study revealed that satisfied couples, in comparison with non-satisfied couples, tend to use constructive problem-solving strategies (Dialogue and Loyalty). They rarely use destructive strategies like Escalation of conflict or Withdrawal. Dialogue is the strategy connected with satisfaction in a most positive manner. These might be very important guidelines to couples' psychotherapy. Loyalty to oneself is a significant positive predictor of male satisfaction is also own Loyalty. The study shows that constructive attitudes are the most significant predictors of marriage satisfaction. It is therefore worth concentrating mostly on them in the psychotherapeutic process instead of eliminating destructive attitudes.

  17. Randomized Clinical Trial of Online Parent Training for Behavior Problems After Early Brain Injury.

    Science.gov (United States)

    Wade, Shari L; Cassedy, Amy E; Shultz, Emily L; Zang, Huaiyu; Zhang, Nanhua; Kirkwood, Michael W; Stancin, Terry; Yeates, Keith O; Taylor, H Gerry

    2017-11-01

    To evaluate the effectiveness of Internet-based Interacting Together Everyday: Recovery After Childhood TBI (I-InTERACT) versus abbreviated parent training (Express) or access to online resources (internet resources comparison [IRC]) in improving parenting skills and decreasing behavior problems after early traumatic brain injury (TBI). In this randomized, controlled, clinical trial, 113 children 3 to 9 years old previously hospitalized for moderate to severe TBI were randomly assigned to receive Express (n = 36), I-InTERACT (n = 39), or IRC (n = 38). Express included 7 online parent skills sessions, and I-InTERACT delivered 10 to 14 sessions addressing parenting skills, TBI education, stress, and anger management. The 2 interventions coupled online modules with therapist coaching through a Health Insurance Portability and Accountability Act-compliant Skype link. The IRC group received access to online TBI and parent skills resources. Co-primary outcomes were blinded ratings of parenting skills and parent report of behavior problems and problem intensity on the Eyberg Child Behavior Inventory (ECBI). Outcomes were assessed before treatment and 3 and 6 months after treatment, with the latter constituting the primary endpoint. The Express and I-InTERACT groups displayed higher levels of positive parenting at follow-up. Only the I-InTERACT group had lower levels of negative parenting at 6 months. The Express group had lower ECBI intensity scores than the IRC group. Baseline symptom levels moderated improvements; children in the Express and I-InTERACT groups with higher baseline symptoms demonstrated greater improvements than those in the IRC group. Changes in parenting skills mediated improvements in behavior in those with higher baseline symptoms. Brief online parent skills training can effectively decrease behavior problems after early TBI in children with existing behavioral symptoms. Clinical trial registration information-Internet-based Interacting Together

  18. Nonlinear Pricing with Random Participation

    OpenAIRE

    Jean-Charles Rochet; Lars A. Stole

    2002-01-01

    The canonical selection contracting programme takes the agent's participation decision as deterministic and finds the optimal contract, typically satisfying this constraint for the worst type. Upon weakening this assumption of known reservation values by introducing independent randomness into the agents' outside options, we find that some of the received wisdom from mechanism design and nonlinear pricing is not robust and the richer model which allows for stochastic participation affords a m...

  19. Control method for multi-input multi-output non-Gaussian random vibration test with cross spectra consideration

    Directory of Open Access Journals (Sweden)

    Ronghui ZHENG

    2017-12-01

    Full Text Available A control method for Multi-Input Multi-Output (MIMO non-Gaussian random vibration test with cross spectra consideration is proposed in the paper. The aim of the proposed control method is to replicate the specified references composed of auto spectral densities, cross spectral densities and kurtoses on the test article in the laboratory. It is found that the cross spectral densities will bring intractable coupling problems and induce difficulty for the control of the multi-output kurtoses. Hence, a sequential phase modification method is put forward to solve the coupling problems in multi-input multi-output non-Gaussian random vibration test. To achieve the specified responses, an improved zero memory nonlinear transformation is utilized first to modify the Fourier phases of the signals with sequential phase modification method to obtain one frame reference response signals which satisfy the reference spectra and reference kurtoses. Then, an inverse system method is used in frequency domain to obtain the continuous stationary drive signals. At the same time, the matrix power control algorithm is utilized to control the spectra and kurtoses of the response signals further. At the end of the paper, a simulation example with a cantilever beam and a vibration shaker test are implemented and the results support the proposed method very well. Keywords: Cross spectra, Kurtosis control, Multi-input multi-output, Non-Gaussian, Random vibration test

  20. Dynamic Restructuring Of Problems In Artificial Intelligence

    Science.gov (United States)

    Schwuttke, Ursula M.

    1992-01-01

    "Dynamic tradeoff evaluation" (DTE) denotes proposed method and procedure for restructuring problem-solving strategies in artificial intelligence to satisfy need for timely responses to changing conditions. Detects situations in which optimal problem-solving strategies cannot be pursued because of real-time constraints, and effects tradeoffs among nonoptimal strategies in such way to minimize adverse effects upon performance of system.

  1. Maximum-principle-satisfying space-time conservation element and solution element scheme applied to compressible multifluids

    KAUST Repository

    Shen, Hua; Wen, Chih-Yung; Parsani, Matteo; Shu, Chi-Wang

    2016-01-01

    A maximum-principle-satisfying space-time conservation element and solution element (CE/SE) scheme is constructed to solve a reduced five-equation model coupled with the stiffened equation of state for compressible multifluids. We first derive a sufficient condition for CE/SE schemes to satisfy maximum-principle when solving a general conservation law. And then we introduce a slope limiter to ensure the sufficient condition which is applicative for both central and upwind CE/SE schemes. Finally, we implement the upwind maximum-principle-satisfying CE/SE scheme to solve the volume-fraction-based five-equation model for compressible multifluids. Several numerical examples are carried out to carefully examine the accuracy, efficiency, conservativeness and maximum-principle-satisfying property of the proposed approach.

  2. Maximum-principle-satisfying space-time conservation element and solution element scheme applied to compressible multifluids

    KAUST Repository

    Shen, Hua

    2016-10-19

    A maximum-principle-satisfying space-time conservation element and solution element (CE/SE) scheme is constructed to solve a reduced five-equation model coupled with the stiffened equation of state for compressible multifluids. We first derive a sufficient condition for CE/SE schemes to satisfy maximum-principle when solving a general conservation law. And then we introduce a slope limiter to ensure the sufficient condition which is applicative for both central and upwind CE/SE schemes. Finally, we implement the upwind maximum-principle-satisfying CE/SE scheme to solve the volume-fraction-based five-equation model for compressible multifluids. Several numerical examples are carried out to carefully examine the accuracy, efficiency, conservativeness and maximum-principle-satisfying property of the proposed approach.

  3. Skew-orthogonal polynomials, differential systems and random matrix theory

    International Nuclear Information System (INIS)

    Ghosh, S.

    2007-01-01

    We study skew-orthogonal polynomials with respect to the weight function exp[-2V (x)], with V (x) = Σ K=1 2d (u K /K)x K , u 2d > 0, d > 0. A finite subsequence of such skew-orthogonal polynomials arising in the study of Orthogonal and Symplectic ensembles of random matrices, satisfy a system of differential-difference-deformation equation. The vectors formed by such subsequence has the rank equal to the degree of the potential in the quaternion sense. These solutions satisfy certain compatibility condition and hence admit a simultaneous fundamental system of solutions. (author)

  4. Pre-service mathematics teachers’ ability in solving well-structured problem

    Science.gov (United States)

    Paradesa, R.

    2018-01-01

    This study aimed to describe the mathematical problem-solving ability of undergraduate students of mathematics education in solving the well-structured problem. The type of this study was qualitative descriptive. The subjects in this study were 100 undergraduate students of Mathematics Education at one of the private universities in Palembang city. The data in this study was collected through two test items with essay form. The results of this study showed that, from the first problem, only 8% students can solve it, but do not check back again to validate the process. Based on a scoring rubric that follows Polya strategy, their answer satisfied 2 4 2 0 patterns. But, from the second problem, 45% students satisfied it. This is because the second problem imitated from the example that was given in learning process. The average score of undergraduate students mathematical problem-solving ability in solving well-structured problems showed 56.00 with standard deviation was 13.22. It means that, from 0 - 100 scale, undergraduate students mathematical problem-solving ability can be categorized low. From this result, the conclusion was undergraduate students of mathematics education in Palembang still have a problem in solving mathematics well-structured problem.

  5. Interference-aware random beam selection schemes for spectrum sharing systems

    KAUST Repository

    Abdallah, Mohamed

    2012-10-19

    Spectrum sharing systems have been recently introduced to alleviate the problem of spectrum scarcity by allowing secondary unlicensed networks to share the spectrum with primary licensed networks under acceptable interference levels to the primary users. In this work, we develop interference-aware random beam selection schemes that provide enhanced performance for the secondary network under the condition that the interference observed by the receivers of the primary network is below a predetermined/acceptable value. We consider a secondary link composed of a transmitter equipped with multiple antennas and a single-antenna receiver sharing the same spectrum with a primary link composed of a single-antenna transmitter and a single-antenna receiver. The proposed schemes select a beam, among a set of power-optimized random beams, that maximizes the signal-to-interference-plus-noise ratio (SINR) of the secondary link while satisfying the primary interference constraint for different levels of feedback information describing the interference level at the primary receiver. For the proposed schemes, we develop a statistical analysis for the SINR statistics as well as the capacity and bit error rate (BER) of the secondary link.

  6. Randomized Strategies for the Plurality Problem

    Czech Academy of Sciences Publication Activity Database

    Král´, D.; Tichý, T.; Sgall, Jiří

    2008-01-01

    Roč. 156, č. 17 (2008), s. 3305-3311 ISSN 0166-218X R&D Projects: GA ČR GA201/05/0124 Institutional research plan: CEZ:AV0Z10190503 Keywords : concrete complexity * randomized algorithms Subject RIV: BA - General Mathematics Impact factor: 0.783, year: 2008

  7. Dirichlet problem for quasi-linear elliptic equations

    Directory of Open Access Journals (Sweden)

    Azeddine Baalal

    2002-10-01

    Full Text Available We study the Dirichlet Problem associated to the quasilinear elliptic problem $$ -sum_{i=1}^{n}frac{partial }{partial x_i}mathcal{A}_i(x,u(x, abla u(x+mathcal{B}(x,u(x,abla u(x=0. $$ Then we define a potential theory related to this problem and we show that the sheaf of continuous solutions satisfies the Bauer axiomatic theory. Submitted April 9, 2002. Published October 2, 2002. Math Subject Classifications: 31C15, 35B65, 35J60. Key Words: Supersolution; Dirichlet problem; obstacle problem; nonlinear potential theory.

  8. A hybrid-type quantum random number generator

    Science.gov (United States)

    Hai-Qiang, Ma; Wu, Zhu; Ke-Jin, Wei; Rui-Xue, Li; Hong-Wei, Liu

    2016-05-01

    This paper proposes a well-performing hybrid-type truly quantum random number generator based on the time interval between two independent single-photon detection signals, which is practical and intuitive, and generates the initial random number sources from a combination of multiple existing random number sources. A time-to-amplitude converter and multichannel analyzer are used for qualitative analysis to demonstrate that each and every step is random. Furthermore, a carefully designed data acquisition system is used to obtain a high-quality random sequence. Our scheme is simple and proves that the random number bit rate can be dramatically increased to satisfy practical requirements. Project supported by the National Natural Science Foundation of China (Grant Nos. 61178010 and 11374042), the Fund of State Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications), China, and the Fundamental Research Funds for the Central Universities of China (Grant No. bupt2014TS01).

  9. Feasibility study of a randomized controlled trial of a telephone-delivered problem-solving-occupational therapy intervention to reduce participation restrictions in rural breast cancer survivors undergoing chemotherapy.

    Science.gov (United States)

    Hegel, Mark T; Lyons, Kathleen D; Hull, Jay G; Kaufman, Peter; Urquhart, Laura; Li, Zhongze; Ahles, Tim A

    2011-10-01

    Breast cancer patients receiving adjuvant chemotherapy often experience functional effects of treatment that limit participation in life activities. The purpose of this study was to examine the feasibility of conducting a randomized controlled trial (RCT) of a novel intervention for these restrictions, determine acceptability of the intervention, and preliminarily assess its effects. A pilot RCT of a telephone-delivered Problem-solving and Occupational Therapy intervention (PST-OT) to improve participation restrictions in rural breast cancer patients undergoing chemotherapy. Thirty-one participants with Stages 1-3 breast cancer were randomized to 6 weekly sessions of PST-OT (n = 15) and usual care (n = 16). The primary study outcome was the feasibility of conducting the trial. Secondary outcomes were functional, quality of life and emotional status as assessed at baseline, 6 and 12 weeks. Of 46 patients referred 31 were enrolled (67% recruitment rate), of which 6 participants withdrew (81% retention rate). Twenty-four participants completed all study-related assessments (77%). Ninety-two percent of PST-OT participants were highly satisfied with the intervention, and 92% reported PST-OT to be helpful/very helpful for overcoming participation restrictions. Ninety-seven percent of planned PST-OT treatment sessions were completed. Completion rates for PST-OT homework tasks were high. Measures of functioning, quality of life, and emotional state favored the PST-OT condition. This pilot study suggests that an RCT of the PST-OT intervention is feasible to conduct with rural breast cancer patients undergoing adjuvant chemotherapy and that PST-OT may have positive effects on function, quality of life, and emotional state. 2010 John Wiley & Sons, Ltd.

  10. Palm theory for random time changes

    Directory of Open Access Journals (Sweden)

    Masakiyo Miyazawa

    2001-01-01

    Full Text Available Palm distributions are basic tools when studying stationarity in the context of point processes, queueing systems, fluid queues or random measures. The framework varies with the random phenomenon of interest, but usually a one-dimensional group of measure-preserving shifts is the starting point. In the present paper, by alternatively using a framework involving random time changes (RTCs and a two-dimensional family of shifts, we are able to characterize all of the above systems in a single framework. Moreover, this leads to what we call the detailed Palm distribution (DPD which is stationary with respect to a certain group of shifts. The DPD has a very natural interpretation as the distribution seen at a randomly chosen position on the extended graph of the RTC, and satisfies a general duality criterion: the DPD of the DPD gives the underlying probability P in return.

  11. Randomness and locality in quantum mechanics

    International Nuclear Information System (INIS)

    Bub, J.

    1976-01-01

    This paper considers the problem of representing the statistical states of a quantum mechanical system by measures on a classical probability space. The Kochen and Specker theorem proves the impossibility of embedding the possibility structure of a quantum mechanical system into a Boolean algebra. It is shown that a hidden variable theory involves a Boolean representation which is not an embedding, and that such a representation cannot recover the quantum statistics for sequential probabilities without introducing a randomization process for the hidden variables which is assumed to apply only on measurement. It is suggested that the relation of incompatability is to be understood as a type of stochastic independence, and that the indeterminism of a quantum mechanical system is engendered by the existence of independent families of properties. Thus, the statistical relations reflect the possibility structure of the system: the probabilities are logical. The hidden variable thesis is influenced by the Copenhagen interpretation of quantum mechanics, i.e. by some version of the disturbance theory of measurement. Hence, the significance of the representation problem is missed, and the completeness of quantum mechanics is seen to turn on the possibility of recovering the quantum statistics by a hidden variable scheme which satisfies certain physically motivated conditions, such as locality. Bell's proof that no local hidden variable theory can reproduce the statistical relations of quantum mechanics is considered. (Auth.)

  12. Social Problem Solving and Depressive Symptoms over Time: A Randomized Clinical Trial of Cognitive-Behavioral Analysis System of Psychotherapy, Brief Supportive Psychotherapy, and Pharmacotherapy

    Science.gov (United States)

    Klein, Daniel N.; Leon, Andrew C.; Li, Chunshan; D'Zurilla, Thomas J.; Black, Sarah R.; Vivian, Dina; Dowling, Frank; Arnow, Bruce A.; Manber, Rachel; Markowitz, John C.; Kocsis, James H.

    2011-01-01

    Objective: Depression is associated with poor social problem solving, and psychotherapies that focus on problem-solving skills are efficacious in treating depression. We examined the associations between treatment, social problem solving, and depression in a randomized clinical trial testing the efficacy of psychotherapy augmentation for…

  13. Group parent-child interaction therapy: A randomized control trial for the treatment of conduct problems in young children.

    Science.gov (United States)

    Niec, Larissa N; Barnett, Miya L; Prewett, Matthew S; Shanley Chatham, Jenelle R

    2016-08-01

    Although efficacious interventions exist for childhood conduct problems, a majority of families in need of services do not receive them. To address problems of treatment access and adherence, innovative adaptations of current interventions are needed. This randomized control trial investigated the relative efficacy of a novel format of parent-child interaction therapy (PCIT), a treatment for young children with conduct problems. Eighty-one families with 3- to 6-year-old children (71.6% boys, 85.2% White) with diagnoses of oppositional defiant or conduct disorder were randomized to individual PCIT (n = 42) or the novel format, Group PCIT. Parents completed standardized measures of children's conduct problems, parenting stress, and social support at intake, posttreatment, and 6-month follow-up. Therapist ratings, parent attendance, and homework completion provided measures of treatment adherence. Throughout treatment, parenting skills were assessed using the Dyadic Parent-Child Interaction Coding System. Parents in both group and individual PCIT reported significant improvements from intake to posttreatment and follow-up in their children's conduct problems and adaptive functioning, as well as significant decreases in parenting stress. Parents in both treatment conditions also showed significant improvements in their parenting skills. There were no interactions between time and treatment format. Contrary to expectation, parents in Group PCIT did not experience greater social support or treatment adherence. Group PCIT was not inferior to individual PCIT and may be a valuable format to reach more families in need of services. Future work should explore the efficiency and sustainability of Group PCIT in community settings. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  14. Group Parent-Child Interaction Therapy: A Randomized Control Trial for the Treatment of Conduct Problems in Young Children

    Science.gov (United States)

    Niec, Larissa N.; Barnett, Miya L.; Prewett, Matthew S.; Shanley, Jenelle

    2016-01-01

    Objective Although efficacious interventions exist for childhood conduct problems, a majority of families in need of services do not receive them. To address problems of treatment access and adherence, innovative adaptations of current interventions are needed. This randomized control trial investigated the relative efficacy of a novel format of parent-child interaction therapy (PCIT), a treatment for young children with conduct problems. Methods Eighty-one families with three- to six-year-old children (71.6% male; 85.2% Caucasian) with diagnoses of oppositional defiant or conduct disorder were randomized to individual PCIT (n = 42) or the novel format, group PCIT. Parents completed standardized measures of children’s conduct problems, parenting stress, and social support at intake, posttreatment, and six-month follow-up. Therapist ratings, parent attendance, and homework completion provided measures of treatment adherence. Throughout treatment, parenting skills were assessed using the Dyadic Parent-Child Interaction Coding System. Results Parents in both group and individual PCIT reported significant improvements from intake to posttreatment and follow-up in their children’s conduct problems and adaptive functioning, as well as significant decreases in parenting stress. Parents in both treatment conditions also showed significant improvements in their parenting skills. There were no interactions between time and treatment format. Contrary to expectation, parents in group PCIT did not experience greater social support or treatment adherence. Conclusions Group PCIT was not inferior to individual PCIT and may be a valuable format to reach more families in need of services. Future work should explore the efficiency and sustainability of group PCIT in community settings. PMID:27018531

  15. Parent training in foster families with children with behavior problems : Follow-up results from a randomized controlled trial

    NARCIS (Netherlands)

    Maaskant, A.M.; van Rooij, F.B.; Overbeek, G.J.; Oort, F.J.; Hermanns, J.M.A.

    2016-01-01

    The present randomized controlled trial examined the four months follow-up effectiveness of Parent Management Training Oregon (PMTO) for parents with foster children (aged 4–12) with severe externalizing behavior problems in long-term foster care arrangements. The aim of PMTO, a relative long and

  16. The effects of multi-disciplinary psycho-social care on socio-economic problems in cancer patients: a cluster-randomized trial.

    Science.gov (United States)

    Singer, Susanne; Roick, Julia; Meixensberger, Jürgen; Schiefke, Franziska; Briest, Susanne; Dietz, Andreas; Papsdorf, Kirsten; Mössner, Joachim; Berg, Thomas; Stolzenburg, Jens-Uwe; Niederwieser, Dietger; Keller, Annette; Kersting, Anette; Danker, Helge

    2018-06-01

    We examined whether multi-disciplinary stepped psycho-social care decreases financial problems and improves return-to-work in cancer patients. In a university hospital, wards were randomly allocated to either stepped or standard care. Stepped care comprised screening for financial problems, consultation between doctor and patient, and the provision of social service. Outcomes were financial problems at the time of discharge and return-to-work in patients financial problems at baseline were less likely to have financial problems at discharge when they had received stepped care (odds ratio (OR) 0.2, 95% confidence interval (CI) 0.1, 0.7; p = 0.01). There was no evidence for an effect of stepped care on financial problems in patients without such problems at baseline (OR 1.1, CI 0.5, 2.6; p = 0.82). There were 399 patients Financial problems can be avoided more effectively with multi-disciplinary stepped psycho-social care than with standard care in patients who have such problems.

  17. Random walks in the quarter plane algebraic methods, boundary value problems, applications to queueing systems and analytic combinatorics

    CERN Document Server

    Fayolle, Guy; Malyshev, Vadim

    2017-01-01

    This monograph aims to promote original mathematical methods to determine the invariant measure of two-dimensional random walks in domains with boundaries. Such processes arise in numerous applications and are of interest in several areas of mathematical research, such as Stochastic Networks, Analytic Combinatorics, and Quantum Physics. This second edition consists of two parts. Part I is a revised upgrade of the first edition (1999), with additional recent results on the group of a random walk. The theoretical approach given therein has been developed by the authors since the early 1970s. By using Complex Function Theory, Boundary Value Problems, Riemann Surfaces, and Galois Theory, completely new methods are proposed for solving functional equations of two complex variables, which can also be applied to characterize the Transient Behavior of the walks, as well as to find explicit solutions to the one-dimensional Quantum Three-Body Problem, or to tackle a new class of Integrable Systems. Part II borrows spec...

  18. Secondary prevention of work-related disability in nonspecific low back pain: does problem-solving therapy help? A randomized clinical trial.

    Science.gov (United States)

    van den Hout, Johanna H C; Vlaeyen, Johan W S; Heuts, Peter H T G; Zijlema, Johan H L; Wijnen, Joseph A G

    2003-01-01

    Given the individual and economic burden of chronic work disability in low back pain patients, there is a need for effective preventive interventions. The aim of the present study was to investigate whether problem-solving therapy had a supplemental value when added to behavioral graded activity, regarding days of sick leave and work status. Randomized controlled trial. Employees who were recently on sick leave as a result of nonspecific low back pain were referred to the rehabilitation center by general practitioner, occupational physician, or rehabilitation physician. Forty-five employees had been randomly assigned to the experimental treatment condition that included behavioral graded activity and problem-solving therapy (GAPS), and 39 employees had been randomly assigned to behavioral graded activity and group education (GAGE). Days of sick leave and work status. Data were retrieved from occupational health services. Data analyses showed that employees in the GAPS group had significantly fewer days of sick leave in the second half-year after the intervention. Moreover, work status was more favorable for employees in this condition, in that more employees had a 100% return-to-work and fewer patients ended up receiving disability pensions one year after the intervention. Sensitivity analyses confirmed these results. The addition of problem-solving therapy to behavioral graded activity had supplemental value in employees with nonspecific low back pain.

  19. Random walk loop soup

    OpenAIRE

    Lawler, Gregory F.; Ferreras, José A. Trujillo

    2004-01-01

    The Brownian loop soup introduced in Lawler and Werner (2004) is a Poissonian realization from a sigma-finite measure on unrooted loops. This measure satisfies both conformal invariance and a restriction property. In this paper, we define a random walk loop soup and show that it converges to the Brownian loop soup. In fact, we give a strong approximation result making use of the strong approximation result of Koml\\'os, Major, and Tusn\\'ady. To make the paper self-contained, we include a proof...

  20. A randomized trial of teen online problem solving: efficacy in improving caregiver outcomes after brain injury.

    Science.gov (United States)

    Wade, Shari L; Walz, Nicolay C; Carey, JoAnne; McMullen, Kendra M; Cass, Jennifer; Mark, Erin; Yeates, Keith Owen

    2012-11-01

    To examine the results of a randomized clinical trial (RCT) of Teen Online Problem Solving (TOPS), an online problem solving therapy model, in increasing problem-solving skills and decreasing depressive symptoms and global distress for caregivers of adolescents with traumatic brain injury (TBI). Families of adolescents aged 11-18 who sustained a moderate to severe TBI between 3 and 19 months earlier were recruited from hospital trauma registries. Participants were assigned to receive a web-based, problem-solving intervention (TOPS, n = 20), or access to online resources pertaining to TBI (Internet Resource Comparison; IRC; n = 21). Parent report of problem solving skills, depressive symptoms, global distress, utilization, and satisfaction were assessed pre- and posttreatment. Groups were compared on follow-up scores after controlling for pretreatment levels. Family income was examined as a potential moderator of treatment efficacy. Improvement in problem solving was examined as a mediator of reductions in depression and distress. Forty-one participants provided consent and completed baseline assessments, with follow-up assessments completed on 35 participants (16 TOPS and 19 IRC). Parents in both groups reported a high level of satisfaction with both interventions. Improvements in problem solving skills and depression were moderated by family income, with caregivers of lower income in TOPS reporting greater improvements. Increases in problem solving partially mediated reductions in global distress. Findings suggest that TOPS may be effective in improving problem solving skills and reducing depressive symptoms for certain subsets of caregivers in families of adolescents with TBI.

  1. Using a satisfiability solver to identify deterministic finite state automata

    NARCIS (Netherlands)

    Heule, M.J.H.; Verwer, S.

    2009-01-01

    We present an exact algorithm for identification of deterministic finite automata (DFA) which is based on satisfiability (SAT) solvers. Despite the size of the low level SAT representation, our approach seems to be competitive with alternative techniques. Our contributions are threefold: First, we

  2. Frequent attenders in general practice: problem solving treatment provided by nurses [ISRCTN51021015

    Directory of Open Access Journals (Sweden)

    van Oppen P

    2005-10-01

    Full Text Available Abstract Background There is a need for assistance from primary care mental health workers in general practice in the Netherlands. General practitioners (GPs experience an overload of frequent attenders suffering from psychological problems. Problem Solving Treatment (PST is a brief psychological treatment tailored for use in a primary care setting. PST is provided by nurses, and earlier research has shown that it is a treatment at least as effective as usual care. However, research outcomes are not totally satisfying. This protocol describes a randomized clinical trial on the effectiveness of PST provided by nurses for patients in general practice. The results of this study, which currently being carried out, will be presented as soon as they are available. Methods/design This study protocol describes the design of a randomized controlled trial to investigate the effectiveness and cost-effectiveness of PST and usual care compared to usual care only. Patients, 18 years and older, who present psychological problems and are frequent attenders in general practice are recruited by the research assistant. The participants receive questionnaires at baseline, after the intervention, and again after 3 months and 9 months. Primary outcome is the reduction of symptoms, and other outcomes measured are improvement in problem solving skills, psychological and physical well being, daily functioning, social support, coping styles, problem evaluation and health care utilization. Discussion Our results may either confirm that PST in primary care is an effective way of dealing with emotional disorders and a promising addition to the primary care in the UK and USA, or may question this assumption. This trial will allow an evaluation of the effects of PST in practical circumstances and in a rather heterogeneous group of primary care patients. This study delivers scientific support for this use and therefore indications for optimal treatment and referral.

  3. Brief telephone interventions for problem gambling: a randomized controlled trial.

    Science.gov (United States)

    Abbott, Max; Hodgins, David C; Bellringer, Maria; Vandal, Alain C; Palmer Du Preez, Katie; Landon, Jason; Sullivan, Sean; Rodda, Simone; Feigin, Valery

    2018-05-01

    Problem gambling is a significant public health issue world-wide. There is substantial investment in publicly funded intervention services, but limited evaluation of effectiveness. This study investigated three brief telephone interventions to determine whether they were more effective than standard helpline treatment in helping people to reduce gambling. Randomized clinical trial. National gambling helpline in New Zealand. A total of 462 adults with problem gambling. INTERVENTIONS AND COMPARATOR: (1) Single motivational interview (MI), (2) single motivational interview plus cognitive-behavioural self-help workbook (MI + W) and (3) single motivational interview plus workbook plus four booster follow-up telephone interviews (MI + W + B). Comparator was helpline standard care [treatment as usual (TAU)]. Blinded follow-up was at 3, 6 and 12 months. Primary outcomes were days gambled, dollars lost per day and treatment goal success. There were no differences across treatment arms, although participants showed large reductions in gambling during the 12-month follow-up period [mean reduction of 5.5 days, confidence interval (CI) = 4.8, 6.2; NZ$38 lost ($32, $44; 80.6%), improved (77.2%, 84.0%)]. Subgroup analysis revealed improved days gambled and dollars lost for MI + W + B over MI or MI + W for a goal of reduction of gambling (versus quitting) and improvement in dollars lost by ethnicity, gambling severity and psychological distress (all P gambling severity than TAU or MI at 12 months and also better for those with higher psychological distress and lower self-efficacy to MI (all P gambling in New Zealand, brief telephone interventions are associated with changes in days gambling and dollars lost similar to more intensive interventions, suggesting that more treatment is not necessarily better than less. Some client subgroups, in particular those with greater problem severity and greater distress, achieve better outcomes when they receive more

  4. Some problems on Monte Carlo method development

    International Nuclear Information System (INIS)

    Pei Lucheng

    1992-01-01

    This is a short paper on some problems of Monte Carlo method development. The content consists of deep-penetration problems, unbounded estimate problems, limitation of Mdtropolis' method, dependency problem in Metropolis' method, random error interference problems and random equations, intellectualisation and vectorization problems of general software

  5. On the satisfiability of quantum circuits of small treewidth

    Czech Academy of Sciences Publication Activity Database

    de Oliveira Oliveira, Mateus

    2017-01-01

    Roč. 61, č. 2 (2017), s. 656-688 ISSN 1432-4350 EU Projects: European Commission(XE) 339691 - FEALORA Institutional support: RVO:67985840 Keywords : treewidth * satisfiability of quantum circuits * tensor networks * Merlin-Arthur protocols Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.645, year: 2016 https://link.springer.com/article/10.1007%2Fs00224-016-9727-8

  6. Are patients satisfied with a web-based followup after total joint arthroplasty?

    Science.gov (United States)

    Marsh, Jacquelyn; Bryant, Dianne; MacDonald, Steven J; Naudie, Douglas; Remtulla, Alliya; McCalden, Richard; Howard, James; Bourne, Robert; McAuley, James

    2014-06-01

    A web-based followup assessment may be a feasible, cost-saving alternative of tracking patient outcomes after total joint arthroplasty. However, before implementing a web-based program, it is important to determine patient satisfaction levels with the new followup method. Satisfaction with the care received is becoming an increasingly important metric, and we do not know to what degree patients are satisfied with an approach to followup that does not involve an in-person visit with their surgeons. We determined (1) patient satisfaction and (2) patients' preferences for followup method (web-based or in-person) after total joint arthroplasty. We randomized patients who were at least 12 months after primary THA or TKA to complete a web-based followup or to have their appointment at the clinic. There were 410 eligible patients contacted for the study during the recruitment period. Of these, 256 agreed to participate, and a total of 229 patients completed the study (89% of those enrolled, 56% of those potentially eligible; 111 in the usual-care group, 118 in the web-based group). Their mean age was 69 years (range, 38-86 years). There was no crossover between groups. All 229 patients completed a satisfaction questionnaire at the time of their followup appointments. Patients in the web-based group also completed a satisfaction and preference questionnaire 1 year later. Only patients from the web-based group were asked to indicate preference as they had experienced the web-based and in-person followup methods. We used descriptive statistics to summarize the satisfaction questionnaires and compared results using Pearson's chi-square test. Ninety-one patients (82.0%) in the usual-care group indicated that they were either extremely or very satisfied with the followup process compared with 90 patients (75.6%) who were in the web-based group (p person followup assessment reported greater satisfaction; however, the difference was small and may not outweigh the additional cost

  7. Level of satisfaction of older persons with their general practitioner and practice: role of complexity of health problems.

    Directory of Open Access Journals (Sweden)

    Antonius J Poot

    Full Text Available BACKGROUND: Satisfaction is widely used to evaluate and direct delivery of medical care; a complicated relationship exists between patient satisfaction, morbidity and age. This study investigates the relationships between complexity of health problems and level of patient satisfaction of older persons with their general practitioner (GP and practice. METHODS AND FINDINGS: This study is embedded in the ISCOPE (Integrated Systematic Care for Older Persons study. Enlisted patients aged ≥75 years from 59 practices received a written questionnaire to screen for complex health problems (somatic, functional, psychological and social. For 2664 randomly chosen respondents (median age 82 years; 68% female information was collected on level of satisfaction (satisfied, neutral, dissatisfied with their GP and general practice, and demographic and clinical characteristics including complexity of health problems. Of all participants, 4% was dissatisfied with their GP care, 59% neutral and 37% satisfied. Between these three categories no differences were observed in age, gender, country of birth or education level. The percentage of participants dissatisfied with their GP care increased from 0.4% in those with 0 problem domains to 8% in those with 4 domains, i.e. having complex health problems (p<0.001. Per additional health domain with problems, the risk of being dissatisfied increased 1.7 times (95% CI 1.4-2.14; p<0.001. This was independent of age, gender, and demographic and clinical parameters (adjusted OR 1.4, 95% CI 1.1-1.8; p = 0.021. CONCLUSION: In older persons, dissatisfaction with general practice is strongly correlated with rising complexity of health problems, independent of age, demographic and clinical parameters. It remains unclear whether complexity of health problems is a patient characteristic influencing the perception of care, or whether the care is unable to handle the demands of these patients. Prospective studies are needed to

  8. Random magnetism

    International Nuclear Information System (INIS)

    Tahir-Kheli, R.A.

    1975-01-01

    A few simple problems relating to random magnetic systems are presented. Translational symmetry, only on the macroscopic scale, is assumed for these systems. A random set of parameters, on the microscopic scale, for the various regions of these systems is also assumed. A probability distribution for randomness is obeyed. Knowledge of the form of these probability distributions, is assumed in all cases [pt

  9. Gender differences in algebraic thinking ability to solve mathematics problems

    Science.gov (United States)

    Kusumaningsih, W.; Darhim; Herman, T.; Turmudi

    2018-05-01

    This study aimed to conduct a gender study on students' algebraic thinking ability in solving a mathematics problem, polyhedron concept, for grade VIII. This research used a qualitative method. The data was collected using: test and interview methods. The subjects in this study were eight male and female students with different level of abilities. It was found that the algebraic thinking skills of male students reached high group of five categories. They were superior in terms of reasoning and quick understanding in solving problems. Algebraic thinking ability of high-achieving group of female students also met five categories of algebraic thinking indicators. They were more diligent, tenacious and thorough in solving problems. Algebraic thinking ability of male students in medium category only satisfied three categories of algebraic thinking indicators. They were sufficient in terms of reasoning and understanding in solving problems. Algebraic thinking ability group of female students in medium group also satisfied three categories of algebraic thinking indicators. They were fairly diligent, tenacious and meticulous on working on the problems.

  10. Two efficient heuristics to solve the integrated load distribution and production planning problem

    International Nuclear Information System (INIS)

    Gajpal, Yuvraj; Nourelfath, Mustapha

    2015-01-01

    This paper considers a multi-period production system where a set of machines are arranged in parallel. The machines are unreliable and the failure rate of machine depends on the load assigned to the machine. The expected production rate of the system is considered to be a non-monotonic function of its load. Because of the machine failure rate, the total production output depends on the combination of loads assigned to different machines. We consider the integration of load distribution decisions with production planning decision. The product demands are considered to be known in advance. The objective is to minimize the sum of holding costs, backorder costs, production costs, setup costs, capacity change costs and unused capacity costs while satisfying the demand over specified time horizon. The constraint is not to exceed available repair resources required to repair the machine breakdown. The paper develops two heuristics to solve the integrated load distribution and production planning problem. The first heuristic consists of a three-phase approach, while the second one is based on tabu search metaheuristic. The efficiency of the proposed heuristics is tested through the randomly generated problem instances. - Highlights: • The expected performance of the system is a non-monotonic function of its load. • We consider the integration of load distribution and production planning decisions. • The paper proposes three phase and tabu search based heuristics to solve the problem. • Lower bound has been developed for checking the effectiveness of the heuristics. • The efficiency of the heuristic is tested through randomly generated instances.

  11. Calculating radiotherapy margins based on Bayesian modelling of patient specific random errors

    International Nuclear Information System (INIS)

    Herschtal, A; Te Marvelde, L; Mengersen, K; Foroudi, F; Ball, D; Devereux, T; Pham, D; Greer, P B; Pichler, P; Eade, T; Kneebone, A; Bell, L; Caine, H; Hindson, B; Kron, T; Hosseinifard, Z

    2015-01-01

    Collected real-life clinical target volume (CTV) displacement data show that some patients undergoing external beam radiotherapy (EBRT) demonstrate significantly more fraction-to-fraction variability in their displacement (‘random error’) than others. This contrasts with the common assumption made by historical recipes for margin estimation for EBRT, that the random error is constant across patients. In this work we present statistical models of CTV displacements in which random errors are characterised by an inverse gamma (IG) distribution in order to assess the impact of random error variability on CTV-to-PTV margin widths, for eight real world patient cohorts from four institutions, and for different sites of malignancy. We considered a variety of clinical treatment requirements and penumbral widths. The eight cohorts consisted of a total of 874 patients and 27 391 treatment sessions. Compared to a traditional margin recipe that assumes constant random errors across patients, for a typical 4 mm penumbral width, the IG based margin model mandates that in order to satisfy the common clinical requirement that 90% of patients receive at least 95% of prescribed RT dose to the entire CTV, margins be increased by a median of 10% (range over the eight cohorts −19% to +35%). This substantially reduces the proportion of patients for whom margins are too small to satisfy clinical requirements. (paper)

  12. A hybrid metaheuristic algorithm for the multi-depot covering tour vehicle routing problem

    NARCIS (Netherlands)

    Allahyari, S.; Salari, M.; Vigo, D.

    2015-01-01

    We propose a generalization of themulti-depot capacitated vehicle routing problem where the assumption of visiting each customer does not hold. In this problem, called the Multi-Depot Covering Tour Vehicle Routing Problem (MDCTVRP), the demand of each customer could be satisfied in two different

  13. Random processes in nuclear reactors

    CERN Document Server

    Williams, M M R

    1974-01-01

    Random Processes in Nuclear Reactors describes the problems that a nuclear engineer may meet which involve random fluctuations and sets out in detail how they may be interpreted in terms of various models of the reactor system. Chapters set out to discuss topics on the origins of random processes and sources; the general technique to zero-power problems and bring out the basic effect of fission, and fluctuations in the lifetime of neutrons, on the measured response; the interpretation of power reactor noise; and associated problems connected with mechanical, hydraulic and thermal noise sources

  14. Maximizing the probability of satisfying the clinical goals in radiation therapy treatment planning under setup uncertainty

    International Nuclear Information System (INIS)

    Fredriksson, Albin; Hårdemark, Björn; Forsgren, Anders

    2015-01-01

    Purpose: This paper introduces a method that maximizes the probability of satisfying the clinical goals in intensity-modulated radiation therapy treatments subject to setup uncertainty. Methods: The authors perform robust optimization in which the clinical goals are constrained to be satisfied whenever the setup error falls within an uncertainty set. The shape of the uncertainty set is included as a variable in the optimization. The goal of the optimization is to modify the shape of the uncertainty set in order to maximize the probability that the setup error will fall within the modified set. Because the constraints enforce the clinical goals to be satisfied under all setup errors within the uncertainty set, this is equivalent to maximizing the probability of satisfying the clinical goals. This type of robust optimization is studied with respect to photon and proton therapy applied to a prostate case and compared to robust optimization using an a priori defined uncertainty set. Results: Slight reductions of the uncertainty sets resulted in plans that satisfied a larger number of clinical goals than optimization with respect to a priori defined uncertainty sets, both within the reduced uncertainty sets and within the a priori, nonreduced, uncertainty sets. For the prostate case, the plans taking reduced uncertainty sets into account satisfied 1.4 (photons) and 1.5 (protons) times as many clinical goals over the scenarios as the method taking a priori uncertainty sets into account. Conclusions: Reducing the uncertainty sets enabled the optimization to find better solutions with respect to the errors within the reduced as well as the nonreduced uncertainty sets and thereby achieve higher probability of satisfying the clinical goals. This shows that asking for a little less in the optimization sometimes leads to better overall plan quality

  15. Determination of Nonlinear Stiffness Coefficients for Finite Element Models with Application to the Random Vibration Problem

    Science.gov (United States)

    Muravyov, Alexander A.

    1999-01-01

    In this paper, a method for obtaining nonlinear stiffness coefficients in modal coordinates for geometrically nonlinear finite-element models is developed. The method requires application of a finite-element program with a geometrically non- linear static capability. The MSC/NASTRAN code is employed for this purpose. The equations of motion of a MDOF system are formulated in modal coordinates. A set of linear eigenvectors is used to approximate the solution of the nonlinear problem. The random vibration problem of the MDOF nonlinear system is then considered. The solutions obtained by application of two different versions of a stochastic linearization technique are compared with linear and exact (analytical) solutions in terms of root-mean-square (RMS) displacements and strains for a beam structure.

  16. Tabu search for the redundancy allocation problem of homogenous series-parallel multi-state systems

    International Nuclear Information System (INIS)

    Ouzineb, Mohamed; Nourelfath, Mustapha; Gendreau, Michel

    2008-01-01

    This paper develops an efficient tabu search (TS) heuristic to solve the redundancy allocation problem for multi-state series-parallel systems. The system has a range of performance levels from perfect functioning to complete failure. Identical redundant elements are included in order to achieve a desirable level of availability. The elements of the system are characterized by their cost, performance and availability. These elements are chosen from a list of products available in the market. System availability is defined as the ability to satisfy consumer demand, which is represented as a piecewise cumulative load curve. A universal generating function technique is applied to evaluate system availability. The proposed TS heuristic determines the minimal cost system configuration under availability constraints. An originality of our approach is that it proceeds by dividing the search space into a set of disjoint subsets, and then by applying TS to each subset. The design problem, solved in this study, has been previously analyzed using genetic algorithms (GAs). Numerical results for the test problems from previous research are reported, and larger test problems are randomly generated. Comparisons show that the proposed TS out-performs GA solutions, in terms of both the solution quality and the execution time

  17. Some properties of the functions satisfying Bell's inequalities in relation to quantum mechanics

    International Nuclear Information System (INIS)

    Roussel, P.

    1986-01-01

    A detailed comparison of Bell's inequalities (B.I.) and quantum mechanics (Q.M.) in an E.P.R.B. situation is given. It is first shown that Q.M. violates the original (3 directions) or generalized (4 directions) B.I. almost everywhere. The properties of functions satisfying the original B.I. are then derived and compared to Q.M. predictions. Finally, the behaviour of functions which satisfy B.I. and attempt to fit Q.M. is described. Altogether, an incompatibility is shown to be stronger than that resulting from just the usual examination

  18. On the Combinatorics of SAT and the Complexity of Planar Problems

    DEFF Research Database (Denmark)

    Talebanfard, Navid

    In this thesis we study several problems arising in Boolean satisfiability ranging from lower bounds for SAT algorithms and proof systems to extremal properties of formulas. The first problem is about construction of hard instances for k-SAT algorithms. For PPSZ algorithm [40] we give the first...

  19. Robust optimization methods for chance constrained, simulation-based, and bilevel problems

    NARCIS (Netherlands)

    Yanikoglu, I.

    2014-01-01

    The objective of robust optimization is to find solutions that are immune to the uncertainty of the parameters in a mathematical optimization problem. It requires that the constraints of a given problem should be satisfied for all realizations of the uncertain parameters in a so-called uncertainty

  20. Online interventions for problem gamblers with and without co-occurring mental health symptoms: Protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    John A. Cunningham

    2016-07-01

    Full Text Available Abstract Background Comorbidity between problem gambling and depression or anxiety is common. Further, the treatment needs of people with co-occurring gambling and mental health symptoms may be different from those of problem gamblers who do not have a co-occurring mental health concern. The current randomized controlled trial (RCT will evaluate whether there is a benefit to providing access to mental health Internet interventions (G + MH intervention in addition to an Internet intervention for problem gambling (G-only intervention in participants with gambling problems who do or do not have co-occurring mental health symptoms. Methods Potential participants will be screened using an online survey to identify participants meeting criteria for problem gambling. As part of the baseline screening process, measures of current depression and anxiety will be assessed. Eligible participants agreeing (N = 280 to take part in the study will be randomized to one of two versions of an online intervention for gamblers – an intervention that just targets gambling issues (G-only versus a website that contains interventions for depression and anxiety in addition to an intervention for gamblers (G + MH. It is predicted that problem gamblers who do not have co-occurring mental health symptoms will display no significant difference between intervention conditions at a six-month follow-up. However, for those with co-occurring mental health symptoms, it is predicted that participants receiving access to the G + MH website will display significantly reduced gambling outcomes at six-month follow-up as compared to those provided with G-only website. Discussion The trial will produce information on the best means of providing online help to gamblers with and without co-occurring mental health symptoms. Trial registration ClinicalTrials.gov NCT02800096 ; Registration date: June 14, 2016.

  1. Typical Werner states satisfying all linear Bell inequalities with dichotomic measurements

    Science.gov (United States)

    Luo, Ming-Xing

    2018-04-01

    Quantum entanglement as a special resource inspires various distinct applications in quantum information processing. Unfortunately, it is NP-hard to detect general quantum entanglement using Bell testing. Our goal is to investigate quantum entanglement with white noises that appear frequently in experiment and quantum simulations. Surprisingly, for almost all multipartite generalized Greenberger-Horne-Zeilinger states there are entangled noisy states that satisfy all linear Bell inequalities consisting of full correlations with dichotomic inputs and outputs of each local observer. This result shows generic undetectability of mixed entangled states in contrast to Gisin's theorem of pure bipartite entangled states in terms of Bell nonlocality. We further provide an accessible method to show a nontrivial set of noisy entanglement with small number of parties satisfying all general linear Bell inequalities. These results imply typical incompleteness of special Bell theory in explaining entanglement.

  2. The quantum-field renormalization group in the problem of a growing phase boundary

    International Nuclear Information System (INIS)

    Antonov, N.V.; Vasil'ev, A.N.

    1995-01-01

    Within the quantum-field renormalization-group approach we examine the stochastic equation discussed by S.I. Pavlik in describing a randomly growing phase boundary. We show that, in contrast to Pavlik's assertion, the model is not multiplicatively renormalizable and that its consistent renormalization-group analysis requires introducing an infinite number of counterterms and the respective coupling constants (open-quotes chargeclose quotes). An explicit calculation in the one-loop approximation shows that a two-dimensional surface of renormalization-group points exits in the infinite-dimensional charge space. If the surface contains an infrared stability region, the problem allows for scaling with the nonuniversal critical dimensionalities of the height of the phase boundary and time, δ h and δ t , which satisfy the exact relationship 2 δ h = δ t + d, where d is the dimensionality of the phase boundary. 23 refs., 1 tab

  3. Uncertain multi-objective multi-product solid transportation problems

    Indian Academy of Sciences (India)

    Deepika Rani

    ... made more effective by incorporating some other factors, which make it useful in real life .... For the above problem to be balanced it should satisfy: ..... Now, first step is to balance the ...... In this work, the fuzzy optimal compromise solution is.

  4. A constructive heuristic for time-dependent multi-depot vehicle routing problem with time-windows and heterogeneous fleet

    Directory of Open Access Journals (Sweden)

    Behrouz Afshar-Nadjafi

    2017-01-01

    Full Text Available In this paper, we consider the time-dependent multi-depot vehicle routing problem. The objective is to minimize the total heterogeneous fleet cost assuming that the travel time between locations depends on the departure time. Also, hard time window constraints for the customers and limitation on maximum number of the vehicles in depots must be satisfied. The problem is formulated as a mixed integer programming model. A constructive heuristic procedure is proposed for the problem. Also, the efficiency of the proposed algorithm is evaluated on 180 test problems. The obtained computational results indicate that the procedure is capable to obtain a satisfying solution.

  5. GRASP with path-relinking for the selective pickup and delivery problem

    DEFF Research Database (Denmark)

    Ho, Sin C.; Szeto, W. Y.

    2016-01-01

    Bike sharing systems are very popular nowadays. One of the characteristics is that bikes are picked up from some surplus bike stations and transported to all deficit bike stations by a repositioning vehicle with limited capacity to satisfy the demand of deficit bike stations. Motivated by this real...... world bicycle repositioning problem, we study the selective pickup and delivery problem, where demand at every delivery node has to be satisfied by the supply collected from a subset of pickup nodes. The objective is to minimize the total travel cost incurred from visiting the nodes. We present a GRASP...... with path-relinking for solving the described problem. Experimental results show that this simple heuristic improves the existing results in the literature with an average improvement of 5.72% using small computing times. The proposed heuristic can contribute to the development of effective and efficient...

  6. Equation satisfied by electron-electron mutual Coulomb repulsion energy density functional

    OpenAIRE

    Joubert, Daniel P.

    2011-01-01

    The electron-electron mutual Coulomb repulsion energy density functional satisfies an equation that links functionals and functional derivatives at N-electron and (N-1)-electron densities for densities determined from the same adiabatic scaled external potential for the N-electron system.

  7. Decompounding random sums: A nonparametric approach

    DEFF Research Database (Denmark)

    Hansen, Martin Bøgsted; Pitts, Susan M.

    Observations from sums of random variables with a random number of summands, known as random, compound or stopped sums arise within many areas of engineering and science. Quite often it is desirable to infer properties of the distribution of the terms in the random sum. In the present paper we...... review a number of applications and consider the nonlinear inverse problem of inferring the cumulative distribution function of the components in the random sum. We review the existing literature on non-parametric approaches to the problem. The models amenable to the analysis are generalized considerably...

  8. Modal Parameter Identification from Responses of General Unknown Random Inputs

    DEFF Research Database (Denmark)

    Ibrahim, S. R.; Asmussen, J. C.; Brincker, Rune

    1996-01-01

    Modal parameter identification from ambient responses due to a general unknown random inputs is investigated. Existing identification techniques which are based on assumptions of white noise and or stationary random inputs are utilized even though the inputs conditions are not satisfied....... This is accomplished via adding. In cascade. A force cascade conversion to the structures system under consideration. The input to the force conversion system is white noise and the output of which is the actual force(s) applied to the structure. The white noise input(s) and the structures responses are then used...

  9. Graphical constraints: a graphical user interface for constraint problems

    OpenAIRE

    Vieira, Nelson Manuel Marques

    2015-01-01

    A constraint satisfaction problem is a classical artificial intelligence paradigm characterized by a set of variables (each variable with an associated domain of possible values), and a set of constraints that specify relations among subsets of these variables. Solutions are assignments of values to all variables that satisfy all the constraints. Many real world problems may be modelled by means of constraints. The range of problems that can use this representation is very diverse and embrace...

  10. Omega-3 Supplementation and Loneliness-Related Memory Problems: Secondary Analyses Of A Randomized Controlled Trial

    Science.gov (United States)

    Jaremka, Lisa M.; Derry, Heather M.; Bornstein, Robert; Prakash, Ruchika Shaurya; Peng, Juan; Belury, Martha A.; Andridge, Rebecca R.; Malarkey, William B.; Kiecolt-Glaser, Janice K.

    2014-01-01

    Objective Loneliness enhances risk for episodic memory declines over time. Omega-3 supplementation can improve cognitive function for people experiencing mild cognitive difficulties. Accordingly, we explored whether omega-3 supplementation would attenuate loneliness-related episodic memory problems. Methods Participants (N=138) from a parent randomized controlled trial (RCT) were randomized to the placebo, 1.25 grams/day of omega-3, or 2.50 grams/day of omega-3 conditions for a 4-month period. They completed a baseline loneliness questionnaire and a battery of cognitive tests both at baseline and at the end of the RCT. Results Controlling for baseline verbal episodic memory scores, lonelier people within the placebo condition had poorer verbal episodic memory post-supplementation, as measured by immediate (b = −0.28, t(117) = −2.62, p = .010) and long-delay (b = −.06, t(116) = −2.07, p = .040) free recall, than their less lonely counterparts. This effect was not observed in the 1.25 grams/day and 2.50 grams/day supplementation groups, all p values > .10. The plasma omega-6:omega-3 ratio data mirrored these results. There were no loneliness-related effects of omega-3 supplementation on short-delay recall or the other cognitive tests, all p values > .32. Conclusion These results suggest that omega-3 supplementation attenuates loneliness-related verbal episodic memory declines over time and support the utility of exploring novel interventions for treating episodic memory problems among lonely people. ClinicalTrials.gov identifier: NCT00385723 PMID:25264972

  11. An optimal control approach to manpower planning problem

    Directory of Open Access Journals (Sweden)

    H. W. J. Lee

    2001-01-01

    Full Text Available A manpower planning problem is studied in this paper. The model includes scheduling different types of workers over different tasks, employing and terminating different types of workers, and assigning different types of workers to various trainning programmes. The aim is to find an optimal way to do all these while keeping the time-varying demand for minimum number of workers working on each different tasks satisfied. The problem is posed as an optimal discrete-valued control problem in discrete time. A novel numerical scheme is proposed to solve the problem, and an illustrative example is provided.

  12. Discrete ordinates transport methods for problems with highly forward-peaked scattering

    International Nuclear Information System (INIS)

    Pautz, S.D.

    1998-04-01

    The author examines the solutions of the discrete ordinates (S N ) method for problems with highly forward-peaked scattering kernels. He derives conditions necessary to obtain reasonable solutions in a certain forward-peaked limit, the Fokker-Planck (FP) limit. He also analyzes the acceleration of the iterative solution of such problems and offer improvements to it. He extends the analytic Fokker-Planck limit analysis to the S N equations. This analysis shows that in this asymptotic limit the S N solution satisfies a pseudospectral discretization of the FP equation, provided that the scattering term is handled in a certain way (which he describes) and that the analytic transport solution satisfies an analytic FP equation. Similar analyses of various spatially discretized S N equations reveal that they too produce solutions that satisfy discrete FP equations, given the same provisions. Numerical results agree with these theoretical predictions. He defines a multidimensional angular multigrid (ANMG) method to accelerate the iterative solution of highly forward-peaked problems. The analyses show that a straightforward application of this scheme is subject to high-frequency instabilities. However, by applying a diffusive filter to the ANMG corrections he is able to stabilize this method. Fourier analyses of model problems show that the resulting method is effective at accelerating the convergence rate when the scattering is forward-peaked. The numerical results demonstrate that these analyses are good predictors of the actual performance of the ANMG method

  13. Reducing and preventing internalizing and externalizing behavior problems in children with type 1 diabetes: a randomized controlled trial of the Triple P-Positive Parenting Program.

    Science.gov (United States)

    Westrupp, E M; Northam, E; Lee, K J; Scratch, S E; Cameron, F

    2015-11-01

    Children with type 1 diabetes are at increased risk of mental health problems, which in turn are associated with poor glycemic control, diabetes-related complications, and long-term psychiatric morbidity. We tested the efficacy of the Triple P-Positive Parenting Program in reducing or preventing mental health problems and improving glycemic control in children with type 1 diabetes in a randomized controlled trial. Participants were recruited from the Diabetes Clinic, Royal Children's Hospital, Melbourne, Australia, and randomized to Triple P or standard diabetes care. The primary outcome was child internalizing and externalizing behavior problems 3 and 12 months postrandomization. Secondary outcomes were glycemic control, parent mental health, parenting skills, and family functioning at 3 and 12 months, and glycemic control at 24 months. A total of 76 participants were randomized (38 to intervention and 38 to control), 60 completed 3-month, and 57 completed 12-month assessments. Benefits of Triple P were evident at 3 months for parent mental health, parenting skills, and family functioning (p externalizing behavior problems indicated greater improvements in child mental health, parent mental health, parenting skills, and diabetes family conflict (p parenting self-efficacy at 3 months. Improvements in parent mental health and parenting competency associated with Triple P were sustained to 12 months for children with pre-existing mental health problems. This study provides some support for the efficacy of Triple P in improving parent and family outcomes, and reducing child internalizing and externalizing behavior problems primarily in children who have pre-existing mental health problems. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. A Column Generation Approach for Solving the Patient Admission Scheduling Problem

    DEFF Research Database (Denmark)

    Range, Troels Martin; Lusby, Richard Martin; Larsen, Jesper

    This paper addresses the Patient Admission Scheduling (PAS) problem. The PAS problem deals with assigning elective patients to beds, satisfying a number of soft and hard constraints. The problem can be seen as part of the functions of hospital management at an operational level. There exists a sm...... to produce new best solutions for ve out of six instances from a publicly available repository....

  15. Multiformity of inherent randomicity and visitation density in n symbolic dynamics

    International Nuclear Information System (INIS)

    Zhang Yagang; Wang Changjiang

    2007-01-01

    The multiformity of inherent randomicity and visitation density in n symbolic dynamics will be clarified in this paper. These stochastic symbolic sequences bear three features. The distribution of frequency, inter-occurrence times and the alignment of two random sequences are amplified in detail. The features of visitation density in surjective maps presents catholicity and the catholicity in n letters randomicity has the same measure foundation. We hope to offer a symbolic platform that satisfies these stochastic properties and to attempt to study certain properties of DNA base sequences, 20 amino acids symbolic sequences of proteid structure, and the time series that can be symbolic in finance market et al

  16. Optimal Wafer Cutting in Shuttle Layout Problems

    DEFF Research Database (Denmark)

    Nisted, Lasse; Pisinger, David; Altman, Avri

    2011-01-01

    . The shuttle layout problem is frequently solved in two phases: first, a floorplan of the shuttle is generated. Then, a cutting plan is found which minimizes the overall number of wafers needed to satisfy the demand of each die type. Since some die types require special production technologies, only compatible...

  17. Cavity approach to the first eigenvalue problem in a family of symmetric random sparse matrices

    International Nuclear Information System (INIS)

    Kabashima, Yoshiyuki; Takahashi, Hisanao; Watanabe, Osamu

    2010-01-01

    A methodology to analyze the properties of the first (largest) eigenvalue and its eigenvector is developed for large symmetric random sparse matrices utilizing the cavity method of statistical mechanics. Under a tree approximation, which is plausible for infinitely large systems, in conjunction with the introduction of a Lagrange multiplier for constraining the length of the eigenvector, the eigenvalue problem is reduced to a bunch of optimization problems of a quadratic function of a single variable, and the coefficients of the first and the second order terms of the functions act as cavity fields that are handled in cavity analysis. We show that the first eigenvalue is determined in such a way that the distribution of the cavity fields has a finite value for the second order moment with respect to the cavity fields of the first order coefficient. The validity and utility of the developed methodology are examined by applying it to two analytically solvable and one simple but non-trivial examples in conjunction with numerical justification.

  18. Curriculum providing cognitive knowledge and problem-solving skills for anesthesia systems-based practice.

    Science.gov (United States)

    Wachtel, Ruth E; Dexter, Franklin

    2010-12-01

    Residency programs accredited by the ACGME are required to teach core competencies, including systems-based practice (SBP). Projects are important for satisfying this competency, but the level of knowledge and problem-solving skills required presupposes a basic understanding of the field. The responsibilities of anesthesiologists include the coordination of patient flow in the surgical suite. Familiarity with this topic is crucial for many improvement projects. A course in operations research for surgical services was originally developed for hospital administration students. It satisfies 2 of the Institute of Medicine's core competencies for health professionals: evidence-based practice and work in interdisciplinary teams. The course lasts 3.5 days (eg, 2 weekends) and consists of 45 cognitive objectives taught using 7 published articles, 10 lectures, and 156 computer-assisted problem-solving exercises based on 17 case studies. We tested the hypothesis that the cognitive objectives of the curriculum provide the knowledge and problem-solving skills necessary to perform projects that satisfy the SBP competency. Standardized terminology was used to define each component of the SBP competency for the minimum level of knowledge needed. The 8 components of the competency were examined independently. Most cognitive objectives contributed to at least 4 of the 8 core components of the SBP competency. Each component of SBP is addressed at the minimum requirement level of exemplify by at least 6 objectives. There is at least 1 cognitive objective at the level of summarize for each SBP component. A curriculum in operating room management can provide the knowledge and problem-solving skills anesthesiologists need for participation in projects that satisfy the SBP competency.

  19. Modeling and solving semiring constraint satisfaction problems by transformation to weighted semiring Max-SAT

    CSIR Research Space (South Africa)

    Leenen, L

    2007-12-01

    Full Text Available The authors present a variant of the Weighted Maximum Satisfiability Problem (Weighted Max-SAT), which is a modeling of the Semiring Constraint Satisfaction framework. They show how to encode a Semiring Constraint Satisfaction Problem (SCSP...

  20. Problems of reducing the exhaustive search

    CERN Document Server

    Kreinovich, V

    1996-01-01

    This collection contains translations of papers on propositional satisfiability and related logical problems which appeared in Problemy Sokrashcheniya Perebora, published in Russian in 1987 by the Scientific Council "Cybernetics" of the USSR Academy of Sciences. The problems form the nucleus of this intensively developing area. This translation is dedicated to the memory of two remarkable Russian mathematicians, Sergei Maslov and his wife, Nina Maslova. Maslov is known as the originator of the inverse method in automated deduction, which was discovered at the same time as the resolution method

  1. Quasihomogeneous function method and Fock's problem

    International Nuclear Information System (INIS)

    Smyshlyaev, V.P.

    1987-01-01

    The diffraction of a high-frequency wave by a smooth convex body near the tangency point of the limiting ray to the surface is restated as the scattering problem for the Schrodinger equation with a linear potential on a half-axis. Various prior estimates for the scattering problem are used in order to prove existence, uniqueness, and smoothness theorems. The corresponding solution satisfies the principle of limiting absorption. The formal solution of the corresponding Schrodinger equation in the form of quasihomogeneous functions is essentially used in their constructions

  2. Towards a Framework for Generating Tests to Satisfy Complex Code Coverage in Java Pathfinder

    Science.gov (United States)

    Staats, Matt

    2009-01-01

    We present work on a prototype tool based on the JavaPathfinder (JPF) model checker for automatically generating tests satisfying the MC/DC code coverage criterion. Using the Eclipse IDE, developers and testers can quickly instrument Java source code with JPF annotations covering all MC/DC coverage obligations, and JPF can then be used to automatically generate tests that satisfy these obligations. The prototype extension to JPF enables various tasks useful in automatic test generation to be performed, such as test suite reduction and execution of generated tests.

  3. Geometrical critical phenomena on a random surface of arbitrary genus

    International Nuclear Information System (INIS)

    Duplantier, B.; Kostov, I.K.

    1990-01-01

    The statistical mechanics of self-avoiding walks (SAW) or of the O(n)-loop model on a two-dimensional random surface are shown to be exactly solvable. The partition functions of SAW and surface configurations (possibly in the presence of vacuum loops) are calculated by planar diagram enumeration techniques. Two critical regimes are found: a dense phase where the infinite walks and loops fill the infinite surface, the non-filled part staying finite, and a dilute phase where the infinite surface singularity on the one hand, and walk and loop singularities on the other, merge together. The configuration critical exponents of self-avoiding networks of any fixed topology G, on a surface with arbitrary genus H, are calculated as universal functions of G and H. For self-avoiding walks, the exponents are built from an infinite set of basic conformal dimensions associated with central charges c = -2 (dense phase) and c = 0 (dilute phase). The conformal spectrum Δ L , L ≥ 1 associated with L-leg star polymers is calculated exactly, for c = -2 and c = 0. This is generalized to the set of L-line 'watermelon' exponents Δ L of the O(n) model on a random surface. The divergences of the partition functions of self-avoiding networks on the random surface, possibly in the presence of vacuum loops, are shown to satisfy a factorization theorem over the vertices of the network. This provides a proof, in the presence of a fluctuating metric, of a result conjectured earlier in the standard plane. From this, the value of the string susceptibility γ str (H,c) is extracted for a random surface of arbitrary genus H, bearing a field theory of central charge c, or equivalently, embedded in d=c dimensions. Lastly, by enumerating spanning trees on a random lattice, we solve the similar problem of hamiltonian walks on the (fluctuating) Manhattan covering lattice. We also obtain new results for dilute trees on a random surface. (orig./HSI)

  4. Levy flights and random searches

    Energy Technology Data Exchange (ETDEWEB)

    Raposo, E P [Laboratorio de Fisica Teorica e Computacional, Departamento de Fisica, Universidade Federal de Pernambuco, Recife-PE, 50670-901 (Brazil); Buldyrev, S V [Department of Physics, Yeshiva University, New York, 10033 (United States); Da Luz, M G E [Departamento de Fisica, Universidade Federal do Parana, Curitiba-PR, 81531-990 (Brazil); Viswanathan, G M [Instituto de Fisica, Universidade Federal de Alagoas, Maceio-AL, 57072-970 (Brazil); Stanley, H E [Center for Polymer Studies and Department of Physics, Boston University, Boston, MA 02215 (United States)

    2009-10-30

    In this work we discuss some recent contributions to the random search problem. Our analysis includes superdiffusive Levy processes and correlated random walks in several regimes of target site density, mobility and revisitability. We present results in the context of mean-field-like and closed-form average calculations, as well as numerical simulations. We then consider random searches performed in regular lattices and lattices with defects, and we discuss a necessary criterion for distinguishing true superdiffusion from correlated random walk processes. We invoke energy considerations in relation to critical survival states on the edge of extinction, and we analyze the emergence of Levy behavior in deterministic search walks. Finally, we comment on the random search problem in the context of biological foraging.

  5. Piping benchmark problems for the Westinghouse AP600 Standardized Plant

    International Nuclear Information System (INIS)

    Bezler, P.; DeGrassi, G.; Braverman, J.; Wang, Y.K.

    1997-01-01

    To satisfy the need for verification of the computer programs and modeling techniques that will be used to perform the final piping analyses for the Westinghouse AP600 Standardized Plant, three benchmark problems were developed. The problems are representative piping systems subjected to representative dynamic loads with solutions developed using the methods being proposed for analysis for the AP600 standard design. It will be required that the combined license licensees demonstrate that their solutions to these problems are in agreement with the benchmark problem set

  6. Orthogonal polynomials and random matrices

    CERN Document Server

    Deift, Percy

    2000-01-01

    This volume expands on a set of lectures held at the Courant Institute on Riemann-Hilbert problems, orthogonal polynomials, and random matrix theory. The goal of the course was to prove universality for a variety of statistical quantities arising in the theory of random matrix models. The central question was the following: Why do very general ensembles of random n {\\times} n matrices exhibit universal behavior as n {\\rightarrow} {\\infty}? The main ingredient in the proof is the steepest descent method for oscillatory Riemann-Hilbert problems.

  7. High Efficiency Computation of the Variances of Structural Evolutionary Random Responses

    Directory of Open Access Journals (Sweden)

    J.H. Lin

    2000-01-01

    Full Text Available For structures subjected to stationary or evolutionary white/colored random noise, their various response variances satisfy algebraic or differential Lyapunov equations. The solution of these Lyapunov equations used to be very difficult. A precise integration method is proposed in the present paper, which solves such Lyapunov equations accurately and very efficiently.

  8. The suitability of the food consumed by children in primary schools for satisfying their needs

    Directory of Open Access Journals (Sweden)

    Yeşim İşgüzar

    2014-12-01

    Full Text Available AbstractObjective: This study evaluates the suitability of the food consumed by children in primary schools including the role of the lunch menus in satisfying the children’s needs. Methods: 852 first-grade students were chosen from 14 randomly selected primary schools in Gaziantep to participate in this descriptive, cross-sectional study. Demographic and personal data of the students and their parents, their anthropometric measurements, food consumption habits and the lunch menus served in schools were studied. The Body Mass Index (BMI of students was evaluated according to World Health Organization (WHO’s percentile tables. Data were analyzed by SPSS 18 software, using the chi-square test for analyses. The study was approved by the Ethics Committee. Results: 51.4% of students were male, 48.6% were female (mean age, 7.05±0.24 years. According to the BMI results, 26.6% of the students were thin and 25.9% were overweight/obese. 73.5% and 85.8% of the children were having breakfast or lunch regularly, respectively. Maternal education levels and employment status did not affect the child’s having breakfast on a daily basis (p>0.05. 27.7 % of children who ate lunch regularly, 15.7% of children who did not eat lunch regularly were overweight/obese (p<0.05. The most consumed food on a regular basis was bread (92.6 %, followed by milk and dairy products (76.5%. When lunch was served in schools (for 24.9% of the students, regular lunch consumption increased among children (p<0.05. The food group the most consumed by the students having lunch at school was fats-sugars-cereals. Only 43.3% of the lunch menus served at schools were found adequate. Conclusions: This study demonstrates that there is a need to improve lunch menus served in primary schools in order to satisfy energy and nutritional needs of children.Keywords: Nutrition, school health, primary school 

  9. Solving the Dial-a-Ride Problem using Genetic algorithms

    DEFF Research Database (Denmark)

    Bergvinsdottir, Kristin Berg; Larsen, Jesper; Jørgensen, Rene Munk

    In the Dial-a-Ride problem (DARP) customers send transportation requests to an operator. A request consists of a specified pickup location and destination location along with a desired departure or arrival time and demand. The aim of DARP is to minimize transportation cost while satisfying custom...... routing problems for the vehicles using a routing heuristic. The algorithm is implemented in Java and tested on publicly available data sets....

  10. Decay of random correlation functions for unimodal maps

    Science.gov (United States)

    Baladi, Viviane; Benedicks, Michael; Maume-Deschamps, Véronique

    2000-10-01

    Since the pioneering results of Jakobson and subsequent work by Benedicks-Carleson and others, it is known that quadratic maps tfa( χ) = a - χ2 admit a unique absolutely continuous invariant measure for a positive measure set of parameters a. For topologically mixing tfa, Young and Keller-Nowicki independently proved exponential decay of correlation functions for this a.c.i.m. and smooth observables. We consider random compositions of small perturbations tf + ωt, with tf = tfa or another unimodal map satisfying certain nonuniform hyperbolicity axioms, and ωt chosen independently and identically in [-ɛ, ɛ]. Baladi-Viana showed exponential mixing of the associated Markov chain, i.e., averaging over all random itineraries. We obtain stretched exponential bounds for the random correlation functions of Lipschitz observables for the sample measure μωof almost every itinerary.

  11. Treatment effectiveness of PMTO for children's behavior problems in Iceland: assessing parenting practices in a randomized controlled trial.

    Science.gov (United States)

    Sigmarsdóttir, Margrét; Degarmo, David S; Forgatch, Marion S; Guðmundsdóttir, Edda Vikar

    2013-12-01

    Findings are presented from an Icelandic randomized control trial (RCT) evaluating parent management training - Oregon model (PMTO™), a parent training intervention designed to improve parenting practices and reduce child behavior problems. In a prior report from this effectiveness study that focused on child outcomes, children in the PMTO condition showed greater reductions in reported child adjustment problems relative to the comparison group. The present report focuses on observed parenting practices as the targeted outcome, with risk by treatment moderators also tested. It was hypothesized that mothers assigned to the PMTO condition would show greater gains in pre-post parenting practices relative to controls. The sample was recruited from five municipalities throughout Iceland and included 102 participating families of children with behavior problems. Cases were referred by community professionals and randomly assigned to either PMTO (n = 51) or community services usually offered (n = 51). Child age ranged from 5 to 12 years; 73% were boys. Contrary to expectations, findings showed no main effects for changes in maternal parenting. However, evaluation of risk by treatment moderators showed greater gains in parenting practices for mothers who increased in depressed mood within the PMTO group relative to their counterparts in the comparison group. This finding suggests that PMTO prevented the expected damaging effects of depression on maternal parenting. Failure to find hypothesized main effects may indicate that there were some unobserved factors regarding the measurement and a need to further adapt the global observational procedures to Icelandic culture. © 2013 The Scandinavian Psychological Associations.

  12. Minimizers of a Class of Constrained Vectorial Variational Problems: Part I

    KAUST Repository

    Hajaiej, Hichem; Markowich, Peter A.; Trabelsi, Saber

    2014-01-01

    In this paper, we prove the existence of minimizers of a class of multiconstrained variational problems. We consider systems involving a nonlinearity that does not satisfy compactness, monotonicity, neither symmetry properties. Our approach hinges

  13. On Helmholtz Problem for Plane Periodical Structures

    International Nuclear Information System (INIS)

    Akishin, P.G.; Vinitskij, S.I.

    1994-01-01

    The plane Helmholtz problem of the periodical disc structures with the phase shifts conditions of the solutions along the basis lattice vectors and the Dirichlet conditions on the basic boundaries is considered. The Green function satisfying the quasi periodical conditions on the lattice is constructed. The Helmholtz problem is reduced to the boundary integral equations for the simple layer potentials of this Green function. The methods of the discretization of the arising integral equations are proposed. The procedures of calculation of the matrix elements are discussed. The reality of the spectral parameter of the nonlinear continuous and discretized problems is shown. 8 refs., 2 figs

  14. Dissipative Control Systems and Disturbance Attenuation for Nonlinear H∞ Problems

    International Nuclear Information System (INIS)

    Frankowska, H.; Quincampoix, M.

    1999-01-01

    We characterize functions satisfying a dissipative inequality associated with a control problem. Such a characterization is provided in terms of an epicontingent solution, or a viscosity supersolution to a partial differential equation called Isaacs' equation. Links between supersolutions and epicontingent solutions to Isaacs' equation are studied. Finally, we derive (possibly discontinuous) disturbance attenuation feedback of the H ∞ problem from contingent formulation of Isaacs' equation

  15. Reflections on the surface energy imbalance problem

    Science.gov (United States)

    Ray Leuning; Eva van Gorsela; William J. Massman; Peter R. Isaac

    2012-01-01

    The 'energy imbalance problem' in micrometeorology arises because at most flux measurement sites the sum of eddy fluxes of sensible and latent heat (H + λE) is less than the available energy (A). Either eddy fluxes are underestimated or A is overestimated. Reasons for the imbalance are: (1) a failure to satisfy the fundamental assumption of one-...

  16. Problem-solving skills training for parents of children with chronic pain: a pilot randomized controlled trial.

    Science.gov (United States)

    Palermo, Tonya M; Law, Emily F; Bromberg, Maggie; Fales, Jessica; Eccleston, Christopher; Wilson, Anna C

    2016-06-01

    This pilot randomized controlled trial aimed to determine the feasibility, acceptability, and preliminary efficacy of parental problem-solving skills training (PSST) compared with treatment as usual on improving parental mental health symptoms, physical health and well-being, and parenting behaviors. Effects of parent PSST on child outcomes (pain, emotional, and physical functioning) were also examined. Participants included 61 parents of children aged 10 to 17 years with chronic pain randomized to PSST (n = 31) or treatment as usual (n = 30) groups. Parents receiving PSST participated in 4 to 6 individual sessions of training in problem-solving skills. Outcomes were assessed at pretreatment, immediately after treatment, and at a 3-month follow-up. Feasibility was determined by therapy session attendance, therapist ratings, and parent treatment acceptability ratings. Feasibility of PSST delivery in this population was demonstrated by high compliance with therapy attendance, excellent retention, high therapist ratings of treatment engagement, and high parent ratings of treatment acceptability. PSST was associated with posttreatment improvements in parental depression (d = -0.68), general mental health (d = 0.64), and pain catastrophizing (d = -0.48), as well as in child depression (d = -0.49), child general anxiety (d = -0.56), and child pain-specific anxiety (d = -0.82). Several effects were maintained at the 3-month follow-up. Findings demonstrate that PSST is feasible and acceptable to parents of youths with chronic pain. Treatment outcome analyses show promising but mixed patterns of effects of PSST on parent and child mental health outcomes. Further rigorous trials of PSST are needed to extend these pilot results.

  17. Optimal decision procedures for satisfiability in fragments of alternating-time temporal logics

    DEFF Research Database (Denmark)

    Goranko, Valentin; Vester, Steen

    2014-01-01

    We consider several natural fragments of the alternating-time temporal logics ATL*and ATL with restrictions on the nesting between temporal operators and strate-gicquantifiers. We develop optimal decision procedures for satisfiability in these fragments, showing that they have much lower complexi...

  18. Mixed-integer programming methods for transportation and power generation problems

    Science.gov (United States)

    Damci Kurt, Pelin

    This dissertation conducts theoretical and computational research to solve challenging problems in application areas such as supply chain and power systems. The first part of the dissertation studies a transportation problem with market choice (TPMC) which is a variant of the classical transportation problem in which suppliers with limited capacities have a choice of which demands (markets) to satisfy. We show that TPMC is strongly NP-complete. We consider a version of the problem with a service level constraint on the maximum number of markets that can be rejected and show that if the original problem is polynomial, its cardinality-constrained version is also polynomial. We propose valid inequalities for mixed-integer cover and knapsack sets with variable upper bound constraints, which appear as substructures of TPMC and use them in a branch-and-cut algorithm to solve this problem. The second part of this dissertation studies a unit commitment (UC) problem in which the goal is to minimize the operational cost of power generators over a time period subject to physical constraints while satisfying demand. We provide several exponential classes of multi-period ramping and multi-period variable upper bound inequalities. We prove the strength of these inequalities and describe polynomial-time separation algorithms. Computational results show the effectiveness of the proposed inequalities when used as cuts in a branch-and-cut algorithm to solve the UC problem. The last part of this dissertation investigates the effects of uncertain wind power on the UC problem. A two-stage robust model and a three-stage stochastic program are compared.

  19. Random number generators and the Metropolis algorithm: application to various problems in physics and mechanics as an introduction to computational physics

    International Nuclear Information System (INIS)

    Calvayrac, Florent

    2005-01-01

    We present known and new applications of pseudo random numbers and of the Metropolis algorithm to phenomena of physical and mechanical interest, such as the search of simple clusters isomers with interactive visualization, or vehicle motion planning. The progression towards complicated problems was used with first-year graduate students who wrote most of the programs presented here. We argue that the use of pseudo random numbers in simulation and extrema research programs in teaching numerical methods in physics allows one to get quick programs and physically meaningful and demonstrative results without recurring to the advanced numerical analysis methods

  20. Operator Spreading in Random Unitary Circuits

    Science.gov (United States)

    Nahum, Adam; Vijay, Sagar; Haah, Jeongwan

    2018-04-01

    Random quantum circuits yield minimally structured models for chaotic quantum dynamics, which are able to capture, for example, universal properties of entanglement growth. We provide exact results and coarse-grained models for the spreading of operators by quantum circuits made of Haar-random unitaries. We study both 1 +1 D and higher dimensions and argue that the coarse-grained pictures carry over to operator spreading in generic many-body systems. In 1 +1 D , we demonstrate that the out-of-time-order correlator (OTOC) satisfies a biased diffusion equation, which gives exact results for the spatial profile of the OTOC and determines the butterfly speed vB. We find that in 1 +1 D , the "front" of the OTOC broadens diffusively, with a width scaling in time as t1 /2. We address fluctuations in the OTOC between different realizations of the random circuit, arguing that they are negligible in comparison to the broadening of the front within a realization. Turning to higher dimensions, we show that the averaged OTOC can be understood exactly via a remarkable correspondence with a purely classical droplet growth problem. This implies that the width of the front of the averaged OTOC scales as t1 /3 in 2 +1 D and as t0.240 in 3 +1 D (exponents of the Kardar-Parisi-Zhang universality class). We support our analytic argument with simulations in 2 +1 D . We point out that, in two or higher spatial dimensions, the shape of the spreading operator at late times is affected by underlying lattice symmetries and, in general, is not spherical. However, when full spatial rotational symmetry is present in 2 +1 D , our mapping implies an exact asymptotic form for the OTOC, in terms of the Tracy-Widom distribution. For an alternative perspective on the OTOC in 1 +1 D , we map it to the partition function of an Ising-like statistical mechanics model. As a result of special structure arising from unitarity, this partition function reduces to a random walk calculation which can be

  1. Internet-Based Acceptance and Commitment Therapy for Psychological Distress Experienced by People With Hearing Problems: Study Protocol for a Randomized Controlled Trial.

    Science.gov (United States)

    Molander, Peter; Hesser, Hugo; Weineland, Sandra; Bergwall, Kajsa; Buck, Sonia; Hansson-Malmlöf, Johan; Lantz, Henning; Lunner, Thomas; Andersson, Gerhard

    2015-09-01

    Psychological distress and psychiatric symptoms are prevalent among people with hearing loss or other audiological conditions, but psychological interventions for these groups are rare. This article describes the study protocol for a randomized controlled trial for evaluating the effect of a psychological treatment delivered over the Internet for individuals with hearing problems and concurrent psychological distress. Participants who are significantly distressed will be randomized to either an 8-week Internet-delivered acceptance-based cognitive behavioral therapy (i.e., acceptance and commitment therapy [ACT]), or wa it-list control. We aim to include measures of distress associated with hearing difficulties, anxiety, and depression. In addition, we aim to measure acceptance associated with hearing difficulties as well as quality of life. The results of the trial may further our understanding of how to best treat people who present problems with both psychological distress and hearing in using the Internet.

  2. Constraint satisfaction problems CSP formalisms and techniques

    CERN Document Server

    Ghedira, Khaled

    2013-01-01

    A Constraint Satisfaction Problem (CSP) consists of a set of variables, a domain of values for each variable and a set of constraints. The objective is to assign a value for each variable such that all constraints are satisfied. CSPs continue to receive increased attention because of both their high complexity and their omnipresence in academic, industrial and even real-life problems. This is why they are the subject of intense research in both artificial intelligence and operations research. This book introduces the classic CSP and details several extensions/improvements of both formalisms a

  3. Minimizers of a Class of Constrained Vectorial Variational Problems: Part I

    KAUST Repository

    Hajaiej, Hichem

    2014-04-18

    In this paper, we prove the existence of minimizers of a class of multiconstrained variational problems. We consider systems involving a nonlinearity that does not satisfy compactness, monotonicity, neither symmetry properties. Our approach hinges on the concentration-compactness approach. In the second part, we will treat orthogonal constrained problems for another class of integrands using density matrices method. © 2014 Springer Basel.

  4. Reducing developmental risk for emotional/behavioral problems: a randomized controlled trial examining the Tools for Getting Along curriculum.

    Science.gov (United States)

    Daunic, Ann P; Smith, Stephen W; Garvan, Cynthia W; Barber, Brian R; Becker, Mallory K; Peters, Christine D; Taylor, Gregory G; Van Loan, Christopher L; Li, Wei; Naranjo, Arlene H

    2012-04-01

    Researchers have demonstrated that cognitive-behavioral intervention strategies - such as social problem solving - provided in school settings can help ameliorate the developmental risk for emotional and behavioral difficulties. In this study, we report the results of a randomized controlled trial of Tools for Getting Along (TFGA), a social problem-solving universally delivered curriculum designed to reduce the developmental risk for serious emotional or behavioral problems among upper elementary grade students. We analyzed pre-intervention and post-intervention teacher-report and student self-report data from 14 schools, 87 classrooms, and a total of 1296 students using multilevel modeling. Results (effect sizes calculated using Hedges' g) indicated that students who were taught TFGA had a more positive approach to problem solving (g=.11) and a more rational problem-solving style (g=.16). Treated students with relatively poor baseline scores benefited from TFGA on (a) problem-solving knowledge (g=1.54); (b) teacher-rated executive functioning (g=.35 for Behavior Regulation and .32 for Metacognition), and proactive aggression (g=.20); and (c) self-reported trait anger (g=.17) and anger expression (g=.21). Thus, TFGA may reduce risk for emotional and behavioral difficulties by improving students' cognitive and emotional self-regulation and increasing their pro-social choices. Copyright © 2011 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  5. Piping benchmark problems for the General Electric Advanced Boiling Water Reactor

    International Nuclear Information System (INIS)

    Bezler, P.; DeGrassi, G.; Braverman, J.; Wang, Y.K.

    1993-08-01

    To satisfy the need for verification of the computer programs and modeling techniques that will be used to perform the final piping analyses for an advanced boiling water reactor standard design, three benchmark problems were developed. The problems are representative piping systems subjected to representative dynamic loads with solutions developed using the methods being proposed for analysis for the advanced reactor standard design. It will be required that the combined license holders demonstrate that their solutions to these problems are in agreement with the benchmark problem set

  6. A problem-solving intervention for cardiovascular disease risk reduction in veterans: Protocol for a randomized controlled trial.

    Science.gov (United States)

    Nieuwsma, Jason A; Wray, Laura O; Voils, Corrine I; Gierisch, Jennifer M; Dundon, Margaret; Coffman, Cynthia J; Jackson, George L; Merwin, Rhonda; Vair, Christina; Juntilla, Karen; White-Clark, Courtney; Jeffreys, Amy S; Harris, Amy; Owings, Michael; Marr, Johnpatrick; Edelman, David

    2017-09-01

    Health behaviors related to diet, tobacco usage, physical activity, medication adherence, and alcohol use are highly determinative of risk for developing cardiovascular disease. This paper describes a study protocol to evaluate a problem-solving intervention that aims to help patients at risk for developing cardiovascular disease address barriers to adopting positive health behaviors in order to reduce cardiovascular risk. Eligible patients are adults enrolled in Veterans Affairs (VA) health care who have not experienced a cardiovascular event but are at elevated risk based on their Framingham Risk Score (FRS). Participants in this two-site study are randomized to either the intervention or care as usual, with a target of 400 participants. The study intervention, Healthy Living Problem-Solving (HELPS), consists of six group sessions conducted approximately monthly interspersed with individualized coaching calls to help participants apply problem-solving principles. The primary outcome is FRS, analyzed at the beginning and end of the study intervention (6months). Participants also complete measures of physical activity, caloric intake, self-efficacy, group cohesion, problem-solving capacities, and demographic characteristics. Results of this trial will inform behavioral interventions to change health behaviors in those at risk for cardiovascular disease and other health conditions. ClinicalTrials.gov identifier NCT01838226. Published by Elsevier Inc.

  7. Solving satisfiability using inclusion-exclusion

    OpenAIRE

    Zaleski, Anthony

    2017-01-01

    Using Maple, we implement a SAT solver based on the principle of inclusion-exclusion and the Bonferroni inequalities. Using randomly generated input, we investigate the performance of our solver as a function of the number of variables and number of clauses. We also test it against Maple's built-in tautology procedure. Finally, we implement the Lov\\'asz local lemma with Maple and discuss its applicability to SAT.

  8. Maximizing the nurses' preferences in nurse scheduling problem: mathematical modeling and a meta-heuristic algorithm

    Science.gov (United States)

    Jafari, Hamed; Salmasi, Nasser

    2015-09-01

    The nurse scheduling problem (NSP) has received a great amount of attention in recent years. In the NSP, the goal is to assign shifts to the nurses in order to satisfy the hospital's demand during the planning horizon by considering different objective functions. In this research, we focus on maximizing the nurses' preferences for working shifts and weekends off by considering several important factors such as hospital's policies, labor laws, governmental regulations, and the status of nurses at the end of the previous planning horizon in one of the largest hospitals in Iran i.e., Milad Hospital. Due to the shortage of available nurses, at first, the minimum total number of required nurses is determined. Then, a mathematical programming model is proposed to solve the problem optimally. Since the proposed research problem is NP-hard, a meta-heuristic algorithm based on simulated annealing (SA) is applied to heuristically solve the problem in a reasonable time. An initial feasible solution generator and several novel neighborhood structures are applied to enhance performance of the SA algorithm. Inspired from our observations in Milad hospital, random test problems are generated to evaluate the performance of the SA algorithm. The results of computational experiments indicate that the applied SA algorithm provides solutions with average percentage gap of 5.49 % compared to the upper bounds obtained from the mathematical model. Moreover, the applied SA algorithm provides significantly better solutions in a reasonable time than the schedules provided by the head nurses.

  9. Predicting successful treatment outcome of web-based self-help for problem drinkers: secondary analysis from a randomized controlled trial.

    Science.gov (United States)

    Riper, Heleen; Kramer, Jeannet; Keuken, Max; Smit, Filip; Schippers, Gerard; Cuijpers, Pim

    2008-11-22

    Web-based self-help interventions for problem drinking are coming of age. They have shown promising results in terms of cost-effectiveness, and they offer opportunities to reach out on a broad scale to problem drinkers. The question now is whether certain groups of problem drinkers benefit more from such Web-based interventions than others. We sought to identify baseline, client-related predictors of the effectiveness of Drinking Less, a 24/7, free-access, interactive, Web-based self-help intervention without therapist guidance for problem drinkers who want to reduce their alcohol consumption. The intervention is based on cognitive-behavioral and self-control principles. We conducted secondary analysis of data from a pragmatic randomized trial with follow-up at 6 and 12 months. Participants (N = 261) were adult problem drinkers in the Dutch general population with a weekly alcohol consumption above 210 g of ethanol for men or 140 g for women, or consumption of at least 60 g (men) or 40 g (women) one or more days a week over the past 3 months. Six baseline participant characteristics were designated as putative predictors of treatment response: (1) gender, (2) education, (3) Internet use competence (sociodemographics), (4) mean weekly alcohol consumption, (5) prior professional help for alcohol problems (level of problem drinking), and (6) participants' expectancies of Web-based interventions for problem drinking. Intention-to-treat (ITT) analyses, using last-observation-carried-forward (LOCF) data, and regression imputation (RI) were performed to deal with loss to follow-up. Statistical tests for interaction terms were conducted and linear regression analysis was performed to investigate whether the participants' characteristics as measured at baseline predicted positive treatment responses at 6- and 12-month follow-ups. At 6 months, prior help for alcohol problems predicted a small, marginally significant positive treatment outcome in the RI model only (beta = .18

  10. An Evolutionary Approach for Bilevel Multi-objective Problems

    Science.gov (United States)

    Deb, Kalyanmoy; Sinha, Ankur

    Evolutionary multi-objective optimization (EMO) algorithms have been extensively applied to find multiple near Pareto-optimal solutions over the past 15 years or so. However, EMO algorithms for solving bilevel multi-objective optimization problems have not received adequate attention yet. These problems appear in many applications in practice and involve two levels, each comprising of multiple conflicting objectives. These problems require every feasible upper-level solution to satisfy optimality of a lower-level optimization problem, thereby making them difficult to solve. In this paper, we discuss a recently proposed bilevel EMO procedure and show its working principle on a couple of test problems and on a business decision-making problem. This paper should motivate other EMO researchers to engage more into this important optimization task of practical importance.

  11. Real Hypersurfaces of Nonflat Complex Projective Planes Whose Jacobi Structure Operator Satisfies a Generalized Commutative Condition

    Directory of Open Access Journals (Sweden)

    Theocharis Theofanidis

    2016-01-01

    Full Text Available Real hypersurfaces satisfying the condition ϕl=lϕ(l=R(·,ξξ have been studied by many authors under at least one more condition, since the class of these hypersurfaces is quite tough to be classified. The aim of the present paper is the classification of real hypersurfaces in complex projective plane CP2 satisfying a generalization of ϕl=lϕ under an additional restriction on a specific function.

  12. Multi-dimensional Bin Packing Problems with Guillotine Constraints

    DEFF Research Database (Denmark)

    Amossen, Rasmus Resen; Pisinger, David

    2010-01-01

    The problem addressed in this paper is the decision problem of determining if a set of multi-dimensional rectangular boxes can be orthogonally packed into a rectangular bin while satisfying the requirement that the packing should be guillotine cuttable. That is, there should exist a series of face...... parallel straight cuts that can recursively cut the bin into pieces so that each piece contains a box and no box has been intersected by a cut. The unrestricted problem is known to be NP-hard. In this paper we present a generalization of a constructive algorithm for the multi-dimensional bin packing...... problem, with and without the guillotine constraint, based on constraint programming....

  13. Processing time tolerance-based ACO algorithm for solving job-shop scheduling problem

    Science.gov (United States)

    Luo, Yabo; Waden, Yongo P.

    2017-06-01

    Ordinarily, Job Shop Scheduling Problem (JSSP) is known as NP-hard problem which has uncertainty and complexity that cannot be handled by a linear method. Thus, currently studies on JSSP are concentrated mainly on applying different methods of improving the heuristics for optimizing the JSSP. However, there still exist many problems for efficient optimization in the JSSP, namely, low efficiency and poor reliability, which can easily trap the optimization process of JSSP into local optima. Therefore, to solve this problem, a study on Ant Colony Optimization (ACO) algorithm combined with constraint handling tactics is carried out in this paper. Further, the problem is subdivided into three parts: (1) Analysis of processing time tolerance-based constraint features in the JSSP which is performed by the constraint satisfying model; (2) Satisfying the constraints by considering the consistency technology and the constraint spreading algorithm in order to improve the performance of ACO algorithm. Hence, the JSSP model based on the improved ACO algorithm is constructed; (3) The effectiveness of the proposed method based on reliability and efficiency is shown through comparative experiments which are performed on benchmark problems. Consequently, the results obtained by the proposed method are better, and the applied technique can be used in optimizing JSSP.

  14. The balanced academic curriculum problem revisited

    DEFF Research Database (Denmark)

    Chiarandini, Marco; Di Gaspero, Luca; Gualandi, Stefano

    2012-01-01

    The Balanced Academic Curriculum Problem (BACP) consists in assigning courses to teaching terms satisfying prerequisites and balancing the credit course load within each term. The BACP is part of the CSPLib with three benchmark instances, but its formulation is simpler than the problem solved...... in practice by universities. In this article, we introduce a generalized version of the problem that takes different curricula and professor preferences into account, and we provide a set of real-life problem instances arisen at University of Udine. Since the existing formulation based on a min-max objective...... function does not balance effectively the credit load for the new instances, we also propose alternative objective functions. Whereas all the CSPLib instances are efficiently solved with Integer Linear Programming (ILP) state-of-the-art solvers, our new set of real-life instances turns out to be much more...

  15. No Randomization? No Problem: Experimental Control and Random Assignment in Single Case Research

    Science.gov (United States)

    Ledford, Jennifer R.

    2018-01-01

    Randomization of large number of participants to different treatment groups is often not a feasible or preferable way to answer questions of immediate interest to professional practice. Single case designs (SCDs) are a class of research designs that are experimental in nature but require only a few participants, all of whom receive the…

  16. The indeterminate rate problem for birth-death processes

    NARCIS (Netherlands)

    van Doorn, Erik A.

    1987-01-01

    A birth-death process is completely determined by its set of rates if and only if this set satisfies a certain condition C, say. If for a set of rates R the condition C is not fulfilled, then the problem arises of characterizing all birth-death processes which have rate set R (the indeterminate rate

  17. An Algorithm to Solve the Equal-Sum-Product Problem

    OpenAIRE

    Nyblom, M. A.; Evans, C. D.

    2013-01-01

    A recursive algorithm is constructed which finds all solutions to a class of Diophantine equations connected to the problem of determining ordered n-tuples of positive integers satisfying the property that their sum is equal to their product. An examination of the use of Binary Search Trees in implementing the algorithm into a working program is given. In addition an application of the algorithm for searching possible extra exceptional values of the equal-sum-product problem is explored after...

  18. Exact Algorithm for the Capacitated Team Orienteering Problem with Time Windows

    Directory of Open Access Journals (Sweden)

    Junhyuk Park

    2017-01-01

    Full Text Available The capacitated team orienteering problem with time windows (CTOPTW is a problem to determine players’ paths that have the maximum rewards while satisfying the constraints. In this paper, we present the exact solution approach for the CTOPTW which has not been done in previous literature. We show that the branch-and-price (B&P scheme which was originally developed for the team orienteering problem can be applied to the CTOPTW. To solve pricing problems, we used implicit enumeration acceleration techniques, heuristic algorithms, and ng-route relaxations.

  19. Brownian Motion Problem: Random Walk and Beyond -RE ...

    Indian Academy of Sciences (India)

    by their continuous bombardment by the surrounding molecules of much smaller size (Figure 1). This effect .... of continuous impacts of the randomly moving surround- ing molecules of the fluid (the 'npise'); (ii) these ..... ually increasing range of values due to integration and, thus, keeping it alive. Consequently, the observed ...

  20. Leading change to create a healthy and satisfying work environment.

    Science.gov (United States)

    Sanders, Carolyn L; Krugman, Mary; Schloffman, Danielle H

    2013-01-01

    Nurse executives must take a leadership role in creating a healthy work environment for nurses and all disciplines. Engaging in partnerships and empowering clinical nurses to construct the solutions to barriers that may stand in the way of the goal of a satisfied and healthy workforce are important strategies toward success. This publication outlines many projects a 3-time Magnet-designated academic hospital has implemented, working with our shared leadership councils, to meet the standards for a healthy work environment. These initiatives, from the unit to the hospital level, included standardizing a culture change of uninterrupted meal breaks, the creation of intensive care unit Zen rooms, strategies to better manage increased patient volumes, best practices for facility design, enhancing physician-nurse relations, and a hospital wellness program. Data were benchmarked against national nurse and employee surveys to compare progress and report outcomes. Two important nursing organization structures that have contributed to the success of a healthy and satisfied nursing work environment include UEXCEL, a longstanding clinical nurse professional practice program, and the hospital's 11-year participation in the University HealthSystem Consortium/American Association of Colleges of Nursing National Post-Baccalaureate Nurse Residency Program. A highly engaged, well-educated, and committed nursing workforce, nurtured by a strong leadership team, has created a positive work environment characterized by low turnover and high retention.

  1. Problem Solving Skills Training for Parents of Children with Chronic Pain: A Pilot Randomized Controlled Trial

    Science.gov (United States)

    Palermo, Tonya M.; Law, Emily F.; Bromberg, Maggie; Fales, Jessica; Eccleston, Christopher; Wilson, Anna C.

    2016-01-01

    This pilot randomized controlled trial aimed to determine the feasibility, acceptability, and preliminary efficacy of parental problem solving skills training (PSST) compared to treatment as usual (TAU) on improving parental mental health symptoms, physical health and well-being, and parenting behaviors. Effects of parent PSST on child outcomes (pain, emotional and physical functioning) were also examined. Participants included 61 parents of children aged 10–17 years with chronic pain randomized to PSST (n = 31) or TAU (n = 30). Parents receiving PSST participated in 4–6 individual sessions of training in problem solving skills. Outcomes were assessed at pre-treatment, immediately post-treatment, and at 3-month follow up. Feasibility was determined by therapy session attendance, therapist ratings, and parent treatment acceptability ratings. Feasibility of PSST delivery in this population was demonstrated by high compliance with therapy attendance, excellent retention, high therapist ratings of treatment engagement, and high parent ratings of treatment acceptability. PSST was associated with post-treatment improvements in parental depression (d = −0.68), general mental health (d = 0.64), and pain catastrophizing (d = −0.48), as well as in child depression (d = −0.49), child general anxiety (d = −0.56), and child pain-specific anxiety (d = −0.82). Several effects were maintained at 3-month follow-up. Findings demonstrate that PSST is feasible and acceptable to parents of youth with chronic pain. Treatment outcome analyses show promising but mixed patterns of effects of PSST on parent and child mental health outcomes. Further rigorous trials of PSST are needed to extend these pilot results. PMID:26845525

  2. Web intervention for OEF/OIF veterans with problem drinking and PTSD symptoms: a randomized clinical trial.

    Science.gov (United States)

    Brief, Deborah J; Rubin, Amy; Keane, Terence M; Enggasser, Justin L; Roy, Monica; Helmuth, Eric; Hermos, John; Lachowicz, Mark; Rybin, Denis; Rosenbloom, David

    2013-10-01

    Veterans who served in Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) commonly experience alcohol misuse and symptoms of posttraumatic stress disorder (PTSD) following their return from deployment to a war zone. We conducted a randomized clinical trial to evaluate the efficacy of a newly developed, 8-module, self-management web intervention (VetChange) based on motivational and cognitive-behavioral principles to reduce alcohol consumption, alcohol-related problems, and PTSD symptoms in returning combat veterans. Six hundred participants, recruited through targeted Facebook ads, were randomized to either an Initial Intervention Group (IIG; n = 404) or a Delayed Intervention Group (DIG; n = 196) that waited 8 weeks for access to VetChange. Primary outcome measures were Drinks per Drinking Day, Average Weekly Drinks, Percent Heavy Drinking Days, and PTSD symptoms. Intent-to-treat analyses compared changes in outcome measures over time between IIG and DIG as well as within-group changes. IIG participants demonstrated greater reductions in drinking (p < .001 for each measure) and PTSD symptoms (p = .009) between baseline and end-of-intervention than did DIG participants between baseline and the end of the waiting period. DIG participants showed similar improvements to those in IIG following participation in VetChange. Alcohol problems were also reduced within each group between baseline and 3-month follow-up. Results indicate that VetChange is effective in reducing drinking and PTSD symptoms in OIF/OEF veterans. Further studies of VetChange are needed to assess web-based recruitment and retention methods and to determine VetChange's effectiveness in demographic and clinical sub-populations of returning veterans. (c) 2013 APA, all rights reserved.

  3. Encouraging Sixth-Grade Students' Problem-Solving Performance by Teaching through Problem Solving

    Science.gov (United States)

    Bostic, Jonathan D.; Pape, Stephen J.; Jacobbe, Tim

    2016-01-01

    This teaching experiment provided students with continuous engagement in a problem-solving based instructional approach during one mathematics unit. Three sections of sixth-grade mathematics were sampled from a school in Florida, U.S.A. and one section was randomly assigned to experience teaching through problem solving. Students' problem-solving…

  4. Online Peer-to-Peer Support for Young People With Mental Health Problems: A Systematic Review.

    Science.gov (United States)

    Ali, Kathina; Farrer, Louise; Gulliver, Amelia; Griffiths, Kathleen M

    2015-01-01

    Adolescence and early adulthood are critical periods for the development of mental disorders. Online peer-to-peer communication is popular among young people and may improve mental health by providing social support. Previous systematic reviews have targeted Internet support groups for adults with mental health problems, including depression. However, there have been no systematic reviews examining the effectiveness of online peer-to-peer support in improving the mental health of adolescents and young adults. The aim of this review was to systematically identify available evidence for the effectiveness of online peer-to peer support for young people with mental health problems. The PubMed, PsycInfo, and Cochrane databases were searched using keywords and Medical Subject Headings (MeSH) terms. Retrieved abstracts (n=3934) were double screened and coded. Studies were included if they (1) investigated an online peer-to-peer interaction, (2) the interaction discussed topics related to mental health, (3) the age range of the sample was between 12 to 25 years, and (4) the study evaluated the effectiveness of the peer-to-peer interaction. Six studies satisfied the inclusion criteria for the current review. The studies targeted a range of mental health problems including depression and anxiety (n=2), general psychological problems (n=1), eating disorders (n=1), and substance use (tobacco) (n=2). The majority of studies investigated Internet support groups (n=4), and the remaining studies focused on virtual reality chat sessions (n=2). In almost all studies (n=5), the peer support intervention was moderated by health professionals, researchers or consumers. Studies employed a range of study designs including randomized controlled trials (n=3), pre-post studies (n=2) and one randomized trial. Overall, two of the randomized controlled trials were associated with a significant positive outcome in comparison to the control group at post-intervention. In the remaining four

  5. constNJ: an algorithm to reconstruct sets of phylogenetic trees satisfying pairwise topological constraints.

    Science.gov (United States)

    Matsen, Frederick A

    2010-06-01

    This article introduces constNJ (constrained neighbor-joining), an algorithm for phylogenetic reconstruction of sets of trees with constrained pairwise rooted subtree-prune-regraft (rSPR) distance. We are motivated by the problem of constructing sets of trees that must fit into a recombination, hybridization, or similar network. Rather than first finding a set of trees that are optimal according to a phylogenetic criterion (e.g., likelihood or parsimony) and then attempting to fit them into a network, constNJ estimates the trees while enforcing specified rSPR distance constraints. The primary input for constNJ is a collection of distance matrices derived from sequence blocks which are assumed to have evolved in a tree-like manner, such as blocks of an alignment which do not contain any recombination breakpoints. The other input is a set of rSPR constraint inequalities for any set of pairs of trees. constNJ is consistent and a strict generalization of the neighbor-joining algorithm; it uses the new notion of maximum agreement partitions (MAPs) to assure that the resulting trees satisfy the given rSPR distance constraints.

  6. The Effect of Yoga Nidra on Psychological Problems of Woman with Menstrual Disorders: a Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Khushbu Rani

    2016-03-01

    Full Text Available Introduction: Menstrual disorders are common problems among women in the reproductive age group. Yuga interventions may decrease the physical and psychological problems related to menstrual disorders. The present study was aimed to assess the effect of Yoga Nidra on psychological problems in patients with menstrual disorders. Methods: A total number of 100 women recruited from the department of obstetrics and gynecology and were then randomly allocated into two groups: a intervention received yogic intervention and medication for 6 month, and b control group received no yogic intervention and they only received prescribed medication. Psychological General Well-Being Index (PGWBI and hormonal profile were assessed at the time of before and after six months on both groups. Results: The mean score of anxiety, depression, positive well-being, general health, and vitality scores, as well as hormonal levels, in posttest were significantly different in intervention group as compared with pretest. But there was no significant difference in control group. Conclusion: Yoga Nidra can be a successful therapy to overcome the psychiatric morbidity associated with menstrual irregularities. Therefore, Yogic relaxation training (Yoga Nidra could be prescribed as an adjunct to conventional drug therapy for menstrual dysfunction.

  7. Complexity of hierarchically and 1-dimensional periodically specified problems

    Energy Technology Data Exchange (ETDEWEB)

    Marathe, M.V.; Hunt, H.B. III; Stearns, R.E.; Radhakrishnan, V.

    1995-08-23

    We study the complexity of various combinatorial and satisfiability problems when instances are specified using one of the following specifications: (1) the 1-dimensional finite periodic narrow specifications of Wanke and Ford et al. (2) the 1-dimensional finite periodic narrow specifications with explicit boundary conditions of Gale (3) the 2-way infinite1-dimensional narrow periodic specifications of Orlin et al. and (4) the hierarchical specifications of Lengauer et al. we obtain three general types of results. First, we prove that there is a polynomial time algorithm that given a 1-FPN- or 1-FPN(BC)specification of a graph (or a C N F formula) constructs a level-restricted L-specification of an isomorphic graph (or formula). This theorem along with the hardness results proved here provides alternative and unified proofs of many hardness results proved in the past either by Lengauer and Wagner or by Orlin. Second, we study the complexity of generalized CNF satisfiability problems of Schaefer. Assuming P {ne} PSPACE, we characterize completely the polynomial time solvability of these problems, when instances are specified as in (1), (2),(3) or (4). As applications of our first two types of results, we obtain a number of new PSPACE-hardness and polynomial time algorithms for problems specified as in (1), (2), (3) or(4). Many of our results also hold for O(log N) bandwidth bounded planar instances.

  8. Molecular computation: RNA solutions to chess problems.

    Science.gov (United States)

    Faulhammer, D; Cukras, A R; Lipton, R J; Landweber, L F

    2000-02-15

    We have expanded the field of "DNA computers" to RNA and present a general approach for the solution of satisfiability problems. As an example, we consider a variant of the "Knight problem," which asks generally what configurations of knights can one place on an n x n chess board such that no knight is attacking any other knight on the board. Using specific ribonuclease digestion to manipulate strands of a 10-bit binary RNA library, we developed a molecular algorithm and applied it to a 3 x 3 chessboard as a 9-bit instance of this problem. Here, the nine spaces on the board correspond to nine "bits" or placeholders in a combinatorial RNA library. We recovered a set of "winning" molecules that describe solutions to this problem.

  9. Some properties of the functions satisfying Bell's inequalities in relation to quantum mechanics

    International Nuclear Information System (INIS)

    Roussel, P.

    1985-01-01

    Having recalled the 1935 debate between A. Einstein and N. Bohr about quantum mechanics (Q.M.) the thought-experiment of D. Bohm is described and a new derivation of the Bell's inequalities is established to test the class of theories based on the hypothesis of hidden-parameters in the common past. It is shown that Q.M. violates these inequalities almost everywhere. The general properties of functions satisfying Bell's inequalities are studied in order to compare them to Q.M. predictions as regards derivatives, integrals, values, intervals, amplitudes and finally the overall behaviour: a few of the Bell's functions chosen to approach somehow Q.M. are given. Altogether, in the comparison between Q.M. and functions satisfying Bell's inequalities, an incompatibility is revealed that is stronger then that resulting from consideration of just the inequalities [fr

  10. Variational Infinite Hidden Conditional Random Fields

    NARCIS (Netherlands)

    Bousmalis, Konstantinos; Zafeiriou, Stefanos; Morency, Louis-Philippe; Pantic, Maja; Ghahramani, Zoubin

    2015-01-01

    Hidden conditional random fields (HCRFs) are discriminative latent variable models which have been shown to successfully learn the hidden structure of a given classification problem. An Infinite hidden conditional random field is a hidden conditional random field with a countably infinite number of

  11. Linear representation of algebras with non-associative operations which are satisfy in the balanced functional equations

    International Nuclear Information System (INIS)

    Ehsani, Amir

    2015-01-01

    Algebras with a pair of non-associative binary operations (f, g) which are satisfy in the balanced quadratic functional equations with four object variables considered. First, we obtain a linear representation for the operations, of this kind of binary algebras (A,f,g), over an abelian group (A, +) and then we generalize the linear representation of operations, to an algebra (A,F) with non-associative binary operations which are satisfy in the balanced quadratic functional equations with four object variables. (paper)

  12. Mathematical Problems in Imaging in Random Media

    Science.gov (United States)

    2015-01-15

    Wigner transforms and ambiguity functions . The phase space approach works for a single target or for groups of targets that are in similar motion (either...x′ ρ(~x′)bj(ω, z, ~x ′)eiβj(ω)z ′ , (4) in terms of the amplitudes aj and bj of the modal expansion of the Green’s function G(t, ~x, ~x ′). We...are normalized trigonometric functions . The random fluctuations cause net scattering effects at ranges z = ε−2Z, with Z & λo. There we have( a(ω, z

  13. Observer-Based Controller Design for a Class of Nonlinear Networked Control Systems with Random Time-Delays Modeled by Markov Chains

    Directory of Open Access Journals (Sweden)

    Yanfeng Wang

    2017-01-01

    Full Text Available This paper investigates the observer-based controller design problem for a class of nonlinear networked control systems with random time-delays. The nonlinearity is assumed to satisfy a global Lipschitz condition and two dependent Markov chains are employed to describe the time-delay from sensor to controller (S-C delay and the time-delay from controller to actuator (C-A delay, respectively. The transition probabilities of S-C delay and C-A delay are both assumed to be partly inaccessible. Sufficient conditions on the stochastic stability for the closed-loop systems are obtained by constructing proper Lyapunov functional. The methods of calculating the controller and the observer gain matrix are also given. Two numerical examples are used to illustrate the effectiveness of the proposed method.

  14. Vibrational spectra of four-coordinated random networks with periodic boundary conditions

    International Nuclear Information System (INIS)

    Guttman, L.

    1976-01-01

    Examples of perfectly four-coordinated networks satisfying periodic boundary conditions are constructed by a pseudo-random process, starting from a crystalline region. The unphysical features (high density, large deviations from the tetrahedral bond-angle) are removed by systematic modification of the bonding scheme. The vibrational spectra are calculated, using a valence-force potential, and the neutron scattering is computed by a phonon-expansion approximation

  15. BWIP-RANDOM-SAMPLING, Random Sample Generation for Nuclear Waste Disposal

    International Nuclear Information System (INIS)

    Sagar, B.

    1989-01-01

    1 - Description of program or function: Random samples for different distribution types are generated. Distribution types as required for performance assessment modeling of geologic nuclear waste disposal are provided. These are: - Uniform, - Log-uniform (base 10 or natural), - Normal, - Lognormal (base 10 or natural), - Exponential, - Bernoulli, - User defined continuous distribution. 2 - Method of solution: A linear congruential generator is used for uniform random numbers. A set of functions is used to transform the uniform distribution to the other distributions. Stratified, rather than random, sampling can be chosen. Truncated limits can be specified on many distributions, whose usual definition has an infinite support. 3 - Restrictions on the complexity of the problem: Generation of correlated random variables is not included

  16. Weighted SGD for ℓp Regression with Randomized Preconditioning*

    Science.gov (United States)

    Yang, Jiyan; Chow, Yin-Lam; Ré, Christopher; Mahoney, Michael W.

    2018-01-01

    In recent years, stochastic gradient descent (SGD) methods and randomized linear algebra (RLA) algorithms have been applied to many large-scale problems in machine learning and data analysis. SGD methods are easy to implement and applicable to a wide range of convex optimization problems. In contrast, RLA algorithms provide much stronger performance guarantees but are applicable to a narrower class of problems. We aim to bridge the gap between these two methods in solving constrained overdetermined linear regression problems—e.g., ℓ2 and ℓ1 regression problems. We propose a hybrid algorithm named pwSGD that uses RLA techniques for preconditioning and constructing an importance sampling distribution, and then performs an SGD-like iterative process with weighted sampling on the preconditioned system.By rewriting a deterministic ℓp regression problem as a stochastic optimization problem, we connect pwSGD to several existing ℓp solvers including RLA methods with algorithmic leveraging (RLA for short).We prove that pwSGD inherits faster convergence rates that only depend on the lower dimension of the linear system, while maintaining low computation complexity. Such SGD convergence rates are superior to other related SGD algorithm such as the weighted randomized Kaczmarz algorithm.Particularly, when solving ℓ1 regression with size n by d, pwSGD returns an approximate solution with ε relative error in the objective value in 𝒪(log n·nnz(A)+poly(d)/ε2) time. This complexity is uniformly better than that of RLA methods in terms of both ε and d when the problem is unconstrained. In the presence of constraints, pwSGD only has to solve a sequence of much simpler and smaller optimization problem over the same constraints. In general this is more efficient than solving the constrained subproblem required in RLA.For ℓ2 regression, pwSGD returns an approximate solution with ε relative error in the objective value and the solution vector measured in

  17. Regularization of the big bang singularity with random perturbations

    Science.gov (United States)

    Belbruno, Edward; Xue, BingKan

    2018-03-01

    We show how to regularize the big bang singularity in the presence of random perturbations modeled by Brownian motion using stochastic methods. We prove that the physical variables in a contracting universe dominated by a scalar field can be continuously and uniquely extended through the big bang as a function of time to an expanding universe only for a discrete set of values of the equation of state satisfying special co-prime number conditions. This result significantly generalizes a previous result (Xue and Belbruno 2014 Class. Quantum Grav. 31 165002) that did not model random perturbations. This result implies that the extension from a contracting to an expanding universe for the discrete set of co-prime equation of state is robust, which is a surprising result. Implications for a purely expanding universe are discussed, such as a non-smooth, randomly varying scale factor near the big bang.

  18. Child-Adult Relationship Enhancement in Primary Care (PriCARE): A Randomized Trial of a Parent Training for Child Behavior Problems.

    Science.gov (United States)

    Schilling, Samantha; French, Benjamin; Berkowitz, Steven J; Dougherty, Susan L; Scribano, Philip V; Wood, Joanne N

    Child-Adult Relationship Enhancement in Primary Care (PriCARE) is a 6-session group parent training designed to teach positive parenting skills. Our objective was to measure PriCARE's impact on child behavior and parenting attitudes. Parents of children 2 to 6 years old with behavior concerns were randomized to PriCARE (n = 80) or control (n = 40). Child behavior and parenting attitudes were measured at baseline (0 weeks), program completion (9 weeks), and 7 weeks after program completion (16 weeks) using the Eyberg Child Behavior Inventory (ECBI) and the Adult Adolescent Parenting Inventory 2 (AAPI2). Linear regression models compared mean ECBI and AAPI2 change scores from 0 to 16 weeks in the PriCARE and control groups, adjusted for baseline scores. Of those randomized to PriCARE, 43% attended 3 or more sessions. Decreases in mean ECBI intensity and problem scores between 0 and 16 weeks were greater in the PriCARE group, reflecting a larger improvement in behavior problems [intensity: -22 (-29, -16) vs -7 (-17, 2), P = .012; problem: -5 (-7, -4) vs -2 (-4, 0), P = .014]. Scores on 3 of the 5 AAPI2 subscales reflected greater improvements in parenting attitudes in the PriCARE group compared to control in the following areas: empathy toward children's needs [0.82 (0.51, 1.14) vs 0.25 (-0.19, 0.70), P = .04], corporal punishment [0.22 (0.00, 0.45) vs -0.30 (-0.61, 0.02), P = .009], and power and independence [0.37 (-0.02, 0.76) vs -0.64 (-1.19, -0.09), P = .003]. PriCARE shows promise in improving parent-reported child-behavior problems in preschool-aged children and increasing positive parenting attitudes. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

  19. Lack of interaction between sensing-intuitive learning styles and problem-first versus information-first instruction: a randomized crossover trial.

    Science.gov (United States)

    Cook, David A; Thompson, Warren G; Thomas, Kris G; Thomas, Matthew R

    2009-03-01

    Adaptation to learning styles has been proposed to enhance learning. We hypothesized that learners with sensing learning style would perform better using a problem-first instructional method while intuitive learners would do better using an information-first method. Randomized, controlled, crossover trial. Resident ambulatory clinics. 123 internal medicine residents. Four Web-based modules in ambulatory internal medicine were developed in both "didactic" (information first, followed by patient problem and questions) and "problem" (case and questions first, followed by information) format. Knowledge posttest, format preference, learning style (Index of Learning Styles). Knowledge scores were similar between the didactic (mean +/- standard error, 83.0 +/- 0.8) and problem (82.3 +/- 0.8) formats (p = .42; 95% confidence interval [CI] for difference, -2.3 to 0.9). There was no difference between formats in regression slopes of knowledge scores on sensing-intuitive scores (p = .63) or in analysis of knowledge scores by styles classification (sensing 82.5 +/- 1.0, intermediate 83.7 +/- 1.2, intuitive 81.0 +/- 1.5; p = .37 for main effect, p = .59 for interaction with format). Format preference was neutral (3.2 +/- 0.2 [1 strongly prefers didactic, 6 strongly prefers problem], p = .12), and there was no association between learning styles and preference (p = .44). Formats were similar in time to complete modules (43.7 +/- 2.2 vs 43.2 +/- 2.2 minutes, p = .72). Starting instruction with a problem (versus employing problems later on) may not improve learning outcomes. Sensing and intuitive learners perform similarly following problem-first and didactic-first instruction. Results may apply to other instructional media.

  20. How satisfied are hospital systems with their ownership of retail clinics?

    Science.gov (United States)

    Kaissi, Amer; Charland, Thomas A

    2013-01-01

    Retail clinics--while innovative--can no longer be considered a new model of healthcare delivery, as an increasing number of hospitals and health systems now own them. The purpose of this article is to explore the extent to which hospital systems are satisfied with their ownership of retail clinics. In terms of operational challenges, respondents to our survey, administered to representatives from 19 health systems, were relatively satisfied with clinic staffing and their relationship with the retailers regarding lease terms, store locations, and shopper demographics. They expressed mostly neutral levels of satisfaction with regulations and laws related to retail clinics and low satisfaction with insurance reimbursement and clinics' seasonal patterns. The two areas that received the lowest respondent satisfaction ratings were patient volume and response to marketing initiatives. When asked to share their perceptions of their organization's satisfaction with various strategic aspects of retail clinic ownership, respondents revealed that the clinics were achieving several important strategic goals, such as improved access, increased referrals, defense against competitors, and increased brand exposure. They indicated overall dissatisfaction with profitability and cost-reduction outcomes. We conclude that serious operational challenges and strategic threats must be overcome if retail clinics are to be a successful service line for hospitals and health systems.

  1. Exact solutions for a discrete unidimensional Boltzmann model satisfying all conservation laws

    International Nuclear Information System (INIS)

    Cornille, H.

    1989-01-01

    We consider a four-velocity discrete and unidimensional Boltzmann model. The mass, momentum and energy conservation laws being satisfied we can define a temperature. We report the exact positive solutions which have been found: periodic in the space and propagating or not when the time is growing, shock waves similarity solutions and (1 + 1)-dimensional solutions [fr

  2. Topological inversion for solution of geodesy-constrained geophysical problems

    Science.gov (United States)

    Saltogianni, Vasso; Stiros, Stathis

    2015-04-01

    Geodetic data, mostly GPS observations, permit to measure displacements of selected points around activated faults and volcanoes, and on the basis of geophysical models, to model the underlying physical processes. This requires inversion of redundant systems of highly non-linear equations with >3 unknowns; a situation analogous to the adjustment of geodetic networks. However, in geophysical problems inversion cannot be based on conventional least-squares techniques, and is based on numerical inversion techniques (a priori fixing of some variables, optimization in steps with values of two variables each time to be regarded fixed, random search in the vicinity of approximate solutions). Still these techniques lead to solutions trapped in local minima, to correlated estimates and to solutions with poor error control (usually sampling-based approaches). To overcome these problems, a numerical-topological, grid-search based technique in the RN space is proposed (N the number of unknown variables). This technique is in fact a generalization and refinement of techniques used in lighthouse positioning and in some cases of low-accuracy 2-D positioning using Wi-Fi etc. The basic concept is to assume discrete possible ranges of each variable, and from these ranges to define a grid G in the RN space, with some of the gridpoints to approximate the true solutions of the system. Each point of hyper-grid G is then tested whether it satisfies the observations, given their uncertainty level, and successful grid points define a sub-space of G containing the true solutions. The optimal (minimal) space containing one or more solutions is obtained using a trial-and-error approach, and a single optimization factor. From this essentially deterministic identification of the set of gridpoints satisfying the system of equations, at a following step, a stochastic optimal solution is computed corresponding to the center of gravity of this set of gridpoints. This solution corresponds to a

  3. Using Stochastic Spiking Neural Networks on SpiNNaker to Solve Constraint Satisfaction Problems

    Directory of Open Access Journals (Sweden)

    Gabriel A. Fonseca Guerra

    2017-12-01

    Full Text Available Constraint satisfaction problems (CSP are at the core of numerous scientific and technological applications. However, CSPs belong to the NP-complete complexity class, for which the existence (or not of efficient algorithms remains a major unsolved question in computational complexity theory. In the face of this fundamental difficulty heuristics and approximation methods are used to approach instances of NP (e.g., decision and hard optimization problems. The human brain efficiently handles CSPs both in perception and behavior using spiking neural networks (SNNs, and recent studies have demonstrated that the noise embedded within an SNN can be used as a computational resource to solve CSPs. Here, we provide a software framework for the implementation of such noisy neural solvers on the SpiNNaker massively parallel neuromorphic hardware, further demonstrating their potential to implement a stochastic search that solves instances of P and NP problems expressed as CSPs. This facilitates the exploration of new optimization strategies and the understanding of the computational abilities of SNNs. We demonstrate the basic principles of the framework by solving difficult instances of the Sudoku puzzle and of the map color problem, and explore its application to spin glasses. The solver works as a stochastic dynamical system, which is attracted by the configuration that solves the CSP. The noise allows an optimal exploration of the space of configurations, looking for the satisfiability of all the constraints; if applied discontinuously, it can also force the system to leap to a new random configuration effectively causing a restart.

  4. Using Stochastic Spiking Neural Networks on SpiNNaker to Solve Constraint Satisfaction Problems.

    Science.gov (United States)

    Fonseca Guerra, Gabriel A; Furber, Steve B

    2017-01-01

    Constraint satisfaction problems (CSP) are at the core of numerous scientific and technological applications. However, CSPs belong to the NP-complete complexity class, for which the existence (or not) of efficient algorithms remains a major unsolved question in computational complexity theory. In the face of this fundamental difficulty heuristics and approximation methods are used to approach instances of NP (e.g., decision and hard optimization problems). The human brain efficiently handles CSPs both in perception and behavior using spiking neural networks (SNNs), and recent studies have demonstrated that the noise embedded within an SNN can be used as a computational resource to solve CSPs. Here, we provide a software framework for the implementation of such noisy neural solvers on the SpiNNaker massively parallel neuromorphic hardware, further demonstrating their potential to implement a stochastic search that solves instances of P and NP problems expressed as CSPs. This facilitates the exploration of new optimization strategies and the understanding of the computational abilities of SNNs. We demonstrate the basic principles of the framework by solving difficult instances of the Sudoku puzzle and of the map color problem, and explore its application to spin glasses. The solver works as a stochastic dynamical system, which is attracted by the configuration that solves the CSP. The noise allows an optimal exploration of the space of configurations, looking for the satisfiability of all the constraints; if applied discontinuously, it can also force the system to leap to a new random configuration effectively causing a restart.

  5. Patterns of Change in Interpersonal Problems During and After Short-term and Long-term Psychodynamic Group Therapy: A Randomized Clinical Trial.

    Science.gov (United States)

    Fjeldstad, Anette; Høglend, Per; Lorentzen, Steinar

    2017-05-01

    In this study, we compared the patterns of change in interpersonal problems between short-term and long-term psychodynamic group therapy. A total of 167 outpatients with mixed diagnoses were randomized to 20 or 80 weekly sessions of group therapy. Interpersonal problems were assessed with the Inventory of Interpersonal Problems at six time points during the 3-year study period. Using linear mixed models, change was linearly modelled in two steps. Earlier (within the first 6 months) and later (during the last 2.5 years) changes in five subscales were estimated. Contrary to what we expected, short-term therapy induced a significantly larger early change than long-term therapy on the cold subscale and there was a trend on the socially avoidant subscale, using a Bonferroni-adjusted alpha. There was no significant difference between short-term and long-term group therapy for improving problems in the areas cold, socially avoidant, nonassertive, exploitable, and overly nurturant over the 3 years.

  6. Solving the Dial-a-Ride Problem using Genetic Algorithms

    DEFF Research Database (Denmark)

    Jørgensen, Rene Munk; Larsen, Jesper; Bergvinsdottir, Kristin Berg

    2007-01-01

    In the Dial-a-Ride problem (DARP), customers request transportation from an operator. A request consists of a specified pickup location and destination location along with a desired departure or arrival time and capacity demand. The aim of DARP is to minimize transportation cost while satisfying ...... routing problems for the vehicles using a routing heuristic. The algorithm is implemented in Java and tested on publicly available data sets. The new solution method has achieved solutions comparable with the current state-of-the-art methods....

  7. Brief interventions to reduce Ecstasy use: a multi-site randomized controlled trial.

    Science.gov (United States)

    Norberg, Melissa M; Hides, Leanne; Olivier, Jake; Khawar, Laila; McKetin, Rebecca; Copeland, Jan

    2014-11-01

    Studies examining the ability of motivational enhancement therapy (MET) to augment education provision among ecstasy users have produced mixed results and none have examined whether treatment fidelity was related to ecstasy use outcomes. The primary objectives of this multi-site, parallel, two-group randomized controlled trial were to determine if a single-session of MET could instill greater commitment to change and reduce ecstasy use and related problems more so than an education-only intervention and whether MET sessions delivered with higher treatment fidelity are associated with better outcomes. The secondary objective was to assess participants' satisfaction with their assigned interventions. Participants (N=174; Mage=23.62) at two Australian universities were allocated randomly to receive a 15-minute educational session on ecstasy use (n=85) or a 50-minute session of MET that included an educational component (n=89). Primary outcomes were assessed at baseline, and then at 4-, 16-, and 24-weeks postbaseline, while the secondary outcome measure was assessed 4-weeks postbaseline by researchers blind to treatment allocation. Overall, the treatment fidelity was acceptable to good in the MET condition. There were no statistical differences at follow-up between the groups on the primary outcomes of ecstasy use, ecstasy-related problems, and commitment to change. Both intervention groups reported a 50% reduction in their ecstasy use and a 20% reduction in the severity of their ecstasy-related problems at the 24-week follow up. Commitment to change slightly improved for both groups (9%-17%). Despite the lack of between-group statistical differences on primary outcomes, participants who received a single session of MET were slightly more satisfied with their intervention than those who received education only. MI fidelity was not associated with ecstasy use outcomes. Given these findings, future research should focus on examining mechanisms of change. Such work may

  8. The Goodness of Covariance Selection Problem from AUC Bounds

    OpenAIRE

    Khajavi, Navid Tafaghodi; Kuh, Anthony

    2016-01-01

    We conduct a study of graphical models and discuss the quality of model selection approximation by formulating the problem as a detection problem and examining the area under the curve (AUC). We are specifically looking at the model selection problem for jointly Gaussian random vectors. For Gaussian random vectors, this problem simplifies to the covariance selection problem which is widely discussed in literature by Dempster [1]. In this paper, we give the definition for the correlation appro...

  9. Application of the random phase approximation to complex problems in materials science

    International Nuclear Information System (INIS)

    Schimka, L.

    2012-01-01

    This thesis is devoted to the assessment and application of the random phase approximation (RPA) in the adiabatic-connection fluctuation-dissipation (ACFD) framework in solid state physics. The first part presents a review of density functional theory (DFT) and the ACFD theorem in the RPA. This includes an introduction to the many-body problem as well as a description of the implementation of the RPA in the Vienna Ab-initio Simulation Package (VASP). In the results part, the quality of the RPA is assessed and its performance compared to three (beyond) DFT functionals. The experimental values are corrected for the effect of phonon zero-point vibrational energies which were calculated at the DFT level from ab-initio. We find that the RPA describes all bonding situations very accurately, making it a promising candidate for more complex problems in solid state physics. In light of these findings, we investigate the carbon-water interaction in two specific cases: the adsorption of water on benzene and the adsorption of water on a graphene layer. We compare our results to a different correlated method: diffusion Monte Carlo (DMC). We find very good agreement and thus believe that our values can serve as a benchmark for the development of other DFT functionals to treat water-carbon interfaces. The highlight of this thesis is the successful application of the RPA to the long-standing and (at DFT level) unsolved CO adsorption puzzle. We show results for CO adsorption on Cu, late 4d metals and Pt. RPA is at present the only ab-initio method that describes adsorption and surface energies accurately at the same time and predicts the correct adsorption site in every single case. (author) [de

  10. Spectral dimensionality of random superconducting networks

    International Nuclear Information System (INIS)

    Day, A.R.; Xia, W.; Thorpe, M.F.

    1988-01-01

    We compute the spectral dimensionality d of random superconducting-normal networks by directly examining the low-frequency density of states at the percolation threshold. We find that d = 4.1 +- 0.2 and 5.8 +- 0.3 in two and three dimensions, respectively, which confirms the scaling relation d = 2d/(2-s/ν), where s is the superconducting exponent and ν the correlation-length exponent for percolation. We also consider the one-dimensional problem where scaling arguments predict, and our numerical simulations confirm, that d = 0. A simple argument provides an expression for the density of states of the localized high-frequency modes in this special case. We comment on the connection between our calculations and the ''termite'' problem of a random walker on a random superconducting-normal network and point out difficulties in inferring d from simulations of the termite problem

  11. THE PROBLEM OF INTERCEPTING PARKING SYSTEMS DESIGN IN CITIES

    Directory of Open Access Journals (Sweden)

    E. Hetsovych

    2014-10-01

    Full Text Available Consistent determination of the main problems concerning the system of intercepting parking – lot design with the purpose of transport systems improvement downtown is grounded. The given approach allows to fully satisfy the demand for parking-lots of urban transport systems in combination with the system of downtown parkings and the capacity of the highway network.

  12. Similarity problems and completely bounded maps

    CERN Document Server

    Pisier, Gilles

    2001-01-01

    These notes revolve around three similarity problems, appearing in three different contexts, but all dealing with the space B(H) of all bounded operators on a complex Hilbert space H. The first one deals with group representations, the second one with C* -algebras and the third one with the disc algebra. We describe them in detail in the introduction which follows. This volume is devoted to the background necessary to understand these three problems, to the solutions that are known in some special cases and to numerous related concepts, results, counterexamples or extensions which their investigation has generated. While the three problems seem different, it is possible to place them in a common framework using the key concept of "complete boundedness", which we present in detail. Using this notion, the three problems can all be formulated as asking whether "boundedness" implies "complete boundedness" for linear maps satisfying certain additional algebraic identities. Two chapters have been added on the HALMO...

  13. Expected number of real roots for random linear combinations of orthogonal polynomials associated with radial weights

    OpenAIRE

    Bayraktar, Turgay

    2017-01-01

    In this note, we obtain asymptotic expected number of real zeros for random polynomials of the form $$f_n(z)=\\sum_{j=0}^na^n_jc^n_jz^j$$ where $a^n_j$ are independent and identically distributed real random variables with bounded $(2+\\delta)$th absolute moment and the deterministic numbers $c^n_j$ are normalizing constants for the monomials $z^j$ within a weighted $L^2$-space induced by a radial weight function satisfying suitable smoothness and growth conditions.

  14. A Coupled Fixed Point Theorem in Fuzzy Metric Space Satisfying ϕ-Contractive Condition

    Directory of Open Access Journals (Sweden)

    B. D. Pant

    2013-01-01

    Full Text Available The intent of this paper is to prove a coupled fixed point theorem for two pairs of compatible and subsequentially continuous (alternately subcompatible and reciprocally continuous mappings, satisfying ϕ-contractive conditions in a fuzzy metric space. We also furnish some illustrative examples to support our results.

  15. On global solutions of the random Hamilton-Jacobi equations and the KPZ problem

    Science.gov (United States)

    Bakhtin, Yuri; Khanin, Konstantin

    2018-04-01

    In this paper, we discuss possible qualitative approaches to the problem of KPZ universality. Throughout the paper, our point of view is based on the geometrical and dynamical properties of minimisers and shocks forming interlacing tree-like structures. We believe that the KPZ universality can be explained in terms of statistics of these structures evolving in time. The paper is focussed on the setting of the random Hamilton-Jacobi equations. We formulate several conjectures concerning global solutions and discuss how their properties are connected to the KPZ scalings in dimension 1  +  1. In the case of general viscous Hamilton-Jacobi equations with non-quadratic Hamiltonians, we define generalised directed polymers. We expect that their behaviour is similar to the behaviour of classical directed polymers, and present arguments in favour of this conjecture. We also define a new renormalisation transformation defined in purely geometrical terms and discuss conjectural properties of the corresponding fixed points. Most of our conjectures are widely open, and supported by only partial rigorous results for particular models.

  16. A Dynamic Programming-Based Heuristic for the Shift Design Problem in Airport Ground Handling

    DEFF Research Database (Denmark)

    Clausen, Tommy

    We consider the heterogeneous shift design problem for a workforce with multiple skills, where work shifts are created to cover a given demand as well as possible while minimizing cost and satisfying a flexible set of constraints. We focus mainly on applications within airport ground handling whe...... programming that allows flexibility in modeling the workforce. Parameters allow a planner to determine the level of demand coverage that best fulfills the requirements of the organization. Results are presented from several diverse real-life ground handling instances.......We consider the heterogeneous shift design problem for a workforce with multiple skills, where work shifts are created to cover a given demand as well as possible while minimizing cost and satisfying a flexible set of constraints. We focus mainly on applications within airport ground handling where...

  17. Skew-orthogonal polynomials and random matrix theory

    CERN Document Server

    Ghosh, Saugata

    2009-01-01

    Orthogonal polynomials satisfy a three-term recursion relation irrespective of the weight function with respect to which they are defined. This gives a simple formula for the kernel function, known in the literature as the Christoffel-Darboux sum. The availability of asymptotic results of orthogonal polynomials and the simple structure of the Christoffel-Darboux sum make the study of unitary ensembles of random matrices relatively straightforward. In this book, the author develops the theory of skew-orthogonal polynomials and obtains recursion relations which, unlike orthogonal polynomials, depend on weight functions. After deriving reduced expressions, called the generalized Christoffel-Darboux formulas (GCD), he obtains universal correlation functions and non-universal level densities for a wide class of random matrix ensembles using the GCD. The author also shows that once questions about higher order effects are considered (questions that are relevant in different branches of physics and mathematics) the ...

  18. Optimal stability polynomials for numerical integration of initial value problems

    KAUST Repository

    Ketcheson, David I.

    2013-01-08

    We consider the problem of finding optimally stable polynomial approximations to the exponential for application to one-step integration of initial value ordinary and partial differential equations. The objective is to find the largest stable step size and corresponding method for a given problem when the spectrum of the initial value problem is known. The problem is expressed in terms of a general least deviation feasibility problem. Its solution is obtained by a new fast, accurate, and robust algorithm based on convex optimization techniques. Global convergence of the algorithm is proven in the case that the order of approximation is one and in the case that the spectrum encloses a starlike region. Examples demonstrate the effectiveness of the proposed algorithm even when these conditions are not satisfied.

  19. The Approximability of Learning and Constraint Satisfaction Problems

    Science.gov (United States)

    2010-10-07

    further improved this result to NP ⊆ naPCP1,3/4+²(O(log(n)),3). Around the same time, Zwick [141] showed that naPCP1,5/8(O(log(n)),3)⊆ BPP by giving a...randomized polynomial-time 5/8-approximation algorithm for satisfiable 3CSP. Therefore unless NP⊆ BPP , the best s must be bigger than 5/8. Zwick... BPP [141]. We think that Question 5.1.2 addresses an important missing part in understanding the 3-query PCP systems. In addition, as is mentioned the

  20. Can quantum probes satisfy the weak equivalence principle?

    International Nuclear Information System (INIS)

    Seveso, Luigi; Paris, Matteo G.A.

    2017-01-01

    We address the question whether quantum probes in a gravitational field can be considered as test particles obeying the weak equivalence principle (WEP). A formulation of the WEP is proposed which applies also in the quantum regime, while maintaining the physical content of its classical counterpart. Such formulation requires the introduction of a gravitational field not to modify the Fisher information about the mass of a freely-falling probe, extractable through measurements of its position. We discover that, while in a uniform field quantum probes satisfy our formulation of the WEP exactly, gravity gradients can encode nontrivial information about the particle’s mass in its wavefunction, leading to violations of the WEP. - Highlights: • Can quantum probes under gravity be approximated as test-bodies? • A formulation of the weak equivalence principle for quantum probes is proposed. • Quantum probes are found to violate it as a matter of principle.

  1. Can quantum probes satisfy the weak equivalence principle?

    Energy Technology Data Exchange (ETDEWEB)

    Seveso, Luigi, E-mail: luigi.seveso@unimi.it [Quantum Technology Lab, Dipartimento di Fisica, Università degli Studi di Milano, I-20133 Milano (Italy); Paris, Matteo G.A. [Quantum Technology Lab, Dipartimento di Fisica, Università degli Studi di Milano, I-20133 Milano (Italy); INFN, Sezione di Milano, I-20133 Milano (Italy)

    2017-05-15

    We address the question whether quantum probes in a gravitational field can be considered as test particles obeying the weak equivalence principle (WEP). A formulation of the WEP is proposed which applies also in the quantum regime, while maintaining the physical content of its classical counterpart. Such formulation requires the introduction of a gravitational field not to modify the Fisher information about the mass of a freely-falling probe, extractable through measurements of its position. We discover that, while in a uniform field quantum probes satisfy our formulation of the WEP exactly, gravity gradients can encode nontrivial information about the particle’s mass in its wavefunction, leading to violations of the WEP. - Highlights: • Can quantum probes under gravity be approximated as test-bodies? • A formulation of the weak equivalence principle for quantum probes is proposed. • Quantum probes are found to violate it as a matter of principle.

  2. Solving the simple plant location problem using a data correcting approach

    NARCIS (Netherlands)

    Goldengorin, Boris

    2001-01-01

    The Data Correcting Algorithm is a branch and bound algorithm in which thedata of a given problem instance is ‘corrected’ at each branching in such a waythat the new instance will be as close as possible to a polynomially solvableinstance and the result satisfies an acceptable accuracy (the

  3. The efficacy of a standardized questionnaire in facilitating personalized communication about problems encountered in cancer genetic counseling: design of a randomized controlled trial.

    Science.gov (United States)

    Eijzenga, Willem; Aaronson, Neil K; Kluijt, Irma; Sidharta, Grace N; Hahn, Daniela Ee; Ausems, Margreet Gem; Bleiker, Eveline Ma

    2014-01-15

    Individuals with a personal or family history of cancer, can opt for genetic counseling and DNA-testing. Approximately 25% of these individuals experience clinically relevant levels of psychosocial distress, depression and/or anxiety after counseling. These problems are frequently left undetected by genetic counselors. The aim of this study is to evaluate the efficacy of a cancer genetics-specific screening questionnaire for psychosocial problems, the 'Psychosocial Aspects of Hereditary Cancer (PAHC) questionnaire' together with the Distress Thermometer, in: (1) facilitating personalized counselor-counselee communication; (2) increasing counselors' awareness of their counselees' psychosocial problems; and (3) facilitating the management of psychosocial problems during and after genetic counseling. This multicenter, randomized controlled trial will include 264 individuals undergoing cancer genetic counseling in two family cancer clinics in the Netherlands. Participants will be randomized to either: (1) an intervention group that completes the PAHC questionnaire, the results of which are made available to the genetic counselor prior to the counseling session; or (2) a control group that completes the PAHC questionnaire, but without feedback being given to the genetic counselor. The genetic counseling sessions will be audiotaped for content analysis. Additionally, study participants will be asked to complete questionnaires at baseline, three weeks after the initial counseling session, and four months after a telephone follow-up counseling session. The genetic counselors will be asked to complete questionnaires at the start of and at completion of the study, as well as a checklist directly after each counseling session. The questionnaires/checklists of the study include items on communication during genetic counseling, counselor awareness of their clients' psychosocial problems, the (perceived) need for professional psychosocial support, cancer worries, general

  4. LETTER TO THE EDITOR: Phase transition in a random fragmentation problem with applications to computer science

    Science.gov (United States)

    Dean, David S.; Majumdar, Satya N.

    2002-08-01

    We study a fragmentation problem where an initial object of size x is broken into m random pieces provided x > x0 where x0 is an atomic cut-off. Subsequently, the fragmentation process continues for each of those daughter pieces whose sizes are bigger than x0. The process stops when all the fragments have sizes smaller than x0. We show that the fluctuation of the total number of splitting events, characterized by the variance, generically undergoes a nontrivial phase transition as one tunes the branching number m through a critical value m = mc. For m mc they are anomalously large and non-Gaussian. We apply this general result to analyse two different search algorithms in computer science.

  5. Minimal Time Problem with Impulsive Controls

    Energy Technology Data Exchange (ETDEWEB)

    Kunisch, Karl, E-mail: karl.kunisch@uni-graz.at [University of Graz, Institute for Mathematics and Scientific Computing (Austria); Rao, Zhiping, E-mail: zhiping.rao@ricam.oeaw.ac.at [Austrian Academy of Sciences, Radon Institute of Computational and Applied Mathematics (Austria)

    2017-02-15

    Time optimal control problems for systems with impulsive controls are investigated. Sufficient conditions for the existence of time optimal controls are given. A dynamical programming principle is derived and Lipschitz continuity of an appropriately defined value functional is established. The value functional satisfies a Hamilton–Jacobi–Bellman equation in the viscosity sense. A numerical example for a rider-swing system is presented and it is shown that the reachable set is enlargered by allowing for impulsive controls, when compared to nonimpulsive controls.

  6. What things make people with a learning disability happy and satisfied with their lives: an inclusive research project.

    Science.gov (United States)

    Haigh, Anna; Lee, Darren; Shaw, Carl; Hawthorne, Michelle; Chamberlain, Stephen; Newman, David W; Clarke, Zara; Beail, Nigel

    2013-01-01

    We looked at the research that other people have done about what makes people with a learning disability happy and satisfied with their lives. Researchers call being happy and satisfied with your life 'subjective well-being'. They found out that having things like money and good health does not always mean people are happy. They also found that some people are really happy, even if there are things in their lives they would like to change. None of the people who have done research about 'subjective well-being' have interviewed people with a learning disability about what makes them happy with their lives. We have carried out a study about what makes people with a learning disability happy and satisfied with their lives. This report talks about the research that we did, and what we found out. We interviewed 20 people with a learning disability who said they were very happy and satisfied. We asked them about what things helped them feel like this. The people we spoke to said things like relationships, choice and independence, activities and valuable social roles made them feel satisfied with their lives. They told us about the things that enable them to lead happy lives, and the things that disable them. We also found out about the importance of personal characteristics. These are things like looking on the bright side of life or having ways to manage difficult emotions like sadness or anger. We found out that it is important for people with a learning disability to have good things in their lives, but it is also important to be enabled to access these good things. © 2012 Blackwell Publishing Ltd.

  7. Solving Large-Scale Computational Problems Using Insights from Statistical Physics

    Energy Technology Data Exchange (ETDEWEB)

    Selman, Bart [Cornell University

    2012-02-29

    Many challenging problems in computer science and related fields can be formulated as constraint satisfaction problems. Such problems consist of a set of discrete variables and a set of constraints between those variables, and represent a general class of so-called NP-complete problems. The goal is to find a value assignment to the variables that satisfies all constraints, generally requiring a search through and exponentially large space of variable-value assignments. Models for disordered systems, as studied in statistical physics, can provide important new insights into the nature of constraint satisfaction problems. Recently, work in this area has resulted in the discovery of a new method for solving such problems, called the survey propagation (SP) method. With SP, we can solve problems with millions of variables and constraints, an improvement of two orders of magnitude over previous methods.

  8. An equation satisfied by the tangent to a shear-free, geodesic, null congruence

    International Nuclear Information System (INIS)

    Hogan, P.A.; Dublin Inst. for Advanced Studies

    1987-01-01

    A tensorial equation satisfied by the tangent to a shear-free geodesic, null congruence is presented. If the congruence is neither twist-free nor expansion-free then the equation defines a second, unique, null direction previously obtained, using the spinor formalism, by Somers. Some further properties of the equation are discussed. (orig.)

  9. First steps in random walks from tools to applications

    CERN Document Server

    Klafter, J

    2011-01-01

    The name ""random walk"" for a problem of a displacement of a point in a sequence of independent random steps was coined by Karl Pearson in 1905 in a question posed to readers of ""Nature"". The same year, a similar problem was formulated by Albert Einstein in one of his Annus Mirabilis works. Even earlier such a problem was posed by Louis Bachelier in his thesis devoted to the theory of financial speculations in 1900. Nowadays the theory of random walks has proved useful in physics andchemistry (diffusion, reactions, mixing in flows), economics, biology (from animal spread to motion of subcel

  10. On solution to the problem of criticality

    International Nuclear Information System (INIS)

    Kyncl, Jan

    2012-05-01

    The problem of criticality for the neutron transport equation was treated. The problem was examined in Lebesgue space L ∞ and was based on some basic assumptions, which are sufficiently general and are in agreement with the spatial behaviour of both temperature and atomic densities of the materials as well as with the properties of all known models of neutron reactions with the medium. The criticality problem was transformed to one of determining the time-asymptotic behaviour of the solution with an initial condition. The initial-value problem was solved numerically by the Monte Carlo method, for which a specific random process and a random variable were constructed

  11. The nodal discrete-ordinate transport calculation of anisotropy scattering problem in three-dimensional cartesian geometry

    International Nuclear Information System (INIS)

    Wu Hongchun; Xie Zhongsheng; Zhu Xuehua

    1994-01-01

    The nodal discrete-ordinate transport calculating model of anisotropy scattering problem in three-dimensional cartesian geometry is given. The computing code NOTRAN/3D has been encoded and the satisfied conclusion is gained

  12. A Geometric Problem and the Hopf Lemma. Ⅱ

    Institute of Scientific and Technical Information of China (English)

    YanYan LI; Louis NIRENBERG

    2006-01-01

    A classical result of A. D. Alexandrov states that a connected compact smooth n-dimensional manifold without boundary, embedded in Rn+1, and such that its mean curvature is constant, is a sphere. Here we study the problem of symmetry of M in a hyperplane Xn+1 =constant in case M satisfies: for any two points (X′, Xn+1), (X′, ^Xn+1)on M, with Xn+1 > ^Hn+1, the mean curvature at the first is not greater than that at the second. Symmetry need not always hold, but in this paper, we establish it under some additional conditions. Some variations of the Hopf Lemma are also presented. Several open problems are described. Part Ⅰ dealt with corresponding one dimensional problems.

  13. Effectiveness of an Online Social Constructivist Mathematical Problem Solving Course for Malaysian Pre-Service Teachers

    Directory of Open Access Journals (Sweden)

    Kim-Leong Lai

    2009-07-01

    Full Text Available This study assessed the effectiveness of an online mathematical problem solving course designed using a social constructivist approach for pre-service teachers. Thirty-seven pre-service teachers at the Batu Lintang Teacher Institute, Sarawak, Malaysia were randomly selected to participate in the study. The participants were required to complete the course online without the typical face-to-face classes and they were also required to solve authentic mathematical problems in small groups of 4-5 participants based on the Polya’s Problem Solving Model via asynchronous online discussions. Quantitative and qualitative methods such as questionnaires and interviews were used to evaluate the effects of the online learning course. Findings showed that a majority of the participants were satisfied with their learning experiences in the course. There were no significant changes in the participants’ attitudes toward mathematics, while the participants’ skills in problem solving for “understand the problem” and “devise a plan” steps based on the Polya Model were significantly enhanced, though no improvement was apparent for “carry out the plan” and “review”. The results also showed that there were significant improvements in the participants’ critical thinking skills. Furthermore, participants with higher initial computer skills were also found to show higher performance in mathematical problem solving as compared to those with lower computer skills. However, there were no significant differences in the participants’ achievements in the course based on gender. Generally, the online social constructivist mathematical problem solving course is beneficial to the participants and ought to be given the attention it deserves as an alternative to traditional classes. Nonetheless, careful considerations need to be made in the designing and implementing of online courses to minimize problems that participants might encounter while

  14. Asymmetrically Dominated Choice Problems, the Isolation Hypothesis and Random Incentive Mechanisms

    OpenAIRE

    Cox, James C.; Sadiraj, Vjollca; Schmidt, Ulrich

    2014-01-01

    This paper presents an experimental study of the random incentive mechanisms which are a standard procedure in economic and psychological experiments. Random incentive mechanisms have several advantages but are incentive-compatible only if responses to the single tasks are independent. This is true if either the independence axiom of expected utility theory or the isolation hypothesis of prospect theory holds. We present a simple test of this in the context of choice under risk. In the baseli...

  15. Analysis of entropy extraction efficiencies in random number generation systems

    Science.gov (United States)

    Wang, Chao; Wang, Shuang; Chen, Wei; Yin, Zhen-Qiang; Han, Zheng-Fu

    2016-05-01

    Random numbers (RNs) have applications in many areas: lottery games, gambling, computer simulation, and, most importantly, cryptography [N. Gisin et al., Rev. Mod. Phys. 74 (2002) 145]. In cryptography theory, the theoretical security of the system calls for high quality RNs. Therefore, developing methods for producing unpredictable RNs with adequate speed is an attractive topic. Early on, despite the lack of theoretical support, pseudo RNs generated by algorithmic methods performed well and satisfied reasonable statistical requirements. However, as implemented, those pseudorandom sequences were completely determined by mathematical formulas and initial seeds, which cannot introduce extra entropy or information. In these cases, “random” bits are generated that are not at all random. Physical random number generators (RNGs), which, in contrast to algorithmic methods, are based on unpredictable physical random phenomena, have attracted considerable research interest. However, the way that we extract random bits from those physical entropy sources has a large influence on the efficiency and performance of the system. In this manuscript, we will review and discuss several randomness extraction schemes that are based on radiation or photon arrival times. We analyze the robustness, post-processing requirements and, in particular, the extraction efficiency of those methods to aid in the construction of efficient, compact and robust physical RNG systems.

  16. Sandwiched Rényi divergence satisfies data processing inequality

    International Nuclear Information System (INIS)

    Beigi, Salman

    2013-01-01

    Sandwiched (quantum) α-Rényi divergence has been recently defined in the independent works of Wilde et al. [“Strong converse for the classical capacity of entanglement-breaking channels,” preprint http://arxiv.org/abs/arXiv:1306.1586 (2013)] and Müller-Lennert et al. [“On quantum Rényi entropies: a new definition, some properties and several conjectures,” preprint http://arxiv.org/abs/arXiv:1306.3142v1 (2013)]. This new quantum divergence has already found applications in quantum information theory. Here we further investigate properties of this new quantum divergence. In particular, we show that sandwiched α-Rényi divergence satisfies the data processing inequality for all values of α > 1. Moreover we prove that α-Holevo information, a variant of Holevo information defined in terms of sandwiched α-Rényi divergence, is super-additive. Our results are based on Hölder's inequality, the Riesz-Thorin theorem and ideas from the theory of complex interpolation. We also employ Sion's minimax theorem

  17. Effectiveness of Parent-Child Mediation in Improving Family Functioning and Reducing Adolescent Problem Behavior: Results from a Pilot Randomized Controlled Trial.

    Science.gov (United States)

    Tucker, Joan S; Edelen, Maria Orlando; Huang, Wenjing

    2017-03-01

    Parent-child mediation programs are intended to resolve or manage disputes and improve family functioning, but rigorous evaluations of their effectiveness are lacking. Families referred to a community-based mediation program (N = 111) were randomized to an intervention or wait-list control group, and completed three surveys over a 12-week period. With the exception of parent-reported child delinquency (which decreased more in the intervention group), this evaluation provides little support for the short-term effectiveness of parent-child mediation for improving family functioning and reducing child problem behaviors in general. Given that this is the first randomized controlled trial of a parent-child mediation program, additional evaluations involving larger samples and longer follow-ups are needed before firm conclusions can be drawn about the effectiveness of this intervention.

  18. Effectiveness of Parent-Child Mediation in Improving Family Functioning and Reducing Adolescent Problem Behavior: Results from a Pilot Randomized Controlled Trial

    Science.gov (United States)

    Tucker, Joan S.; Edelen, Maria Orlando; Huang, Wenjing

    2016-01-01

    Parent-child mediation programs are intended to resolve or manage disputes and improve family functioning, but rigorous evaluations of their effectiveness are lacking. Families referred to a community-based mediation program (N=111) were randomized to an intervention or wait-list control group, and completed three surveys over a 12-week period. With the exception of parent-reported child delinquency (which decreased more in the intervention group), this evaluation provides little support for the short-term effectiveness of parent-child mediation for improving family functioning and reducing child problem behaviors in general. Given that this is the first randomized controlled trial of a parent-child mediation program, additional evaluations involving larger samples and longer follow-ups are needed before firm conclusions can be drawn about the effectiveness of this intervention. PMID:26762375

  19. Reliability Based Optimization of Structural Systems

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    1987-01-01

    The optimization problem to design structural systems such that the reliability is satisfactory during the whole lifetime of the structure is considered in this paper. Some of the quantities modelling the loads and the strength of the structure are modelled as random variables. The reliability...... is estimated using first. order reliability methods ( FORM ). The design problem is formulated as the optimization problem to minimize a given cost function such that the reliability of the single elements satisfies given requirements or such that the systems reliability satisfies a given requirement....... For these optimization problems it is described how a sensitivity analysis can be performed. Next, new optimization procedures to solve the optimization problems are presented. Two of these procedures solve the system reliability based optimization problem sequentially using quasi-analytical derivatives. Finally...

  20. A DIFFERENTIAL EVOLUTION ALGORITHM DEVELOPED FOR A NURSE SCHEDULING PROBLEM

    Directory of Open Access Journals (Sweden)

    Shahnazari-Shahrezaei, P.

    2012-11-01

    Full Text Available Nurse scheduling is a type of manpower allocation problem that tries to satisfy hospital managers objectives and nurses preferences as much as possible by generating fair shift schedules. This paper presents a nurse scheduling problem based on a real case study, and proposes two meta-heuristics a differential evolution algorithm (DE and a greedy randomised adaptive search procedure (GRASP to solve it. To investigate the efficiency of the proposed algorithms, two problems are solved. Furthermore, some comparison metrics are applied to examine the reliability of the proposed algorithms. The computational results in this paper show that the proposed DE outperforms the GRASP.

  1. Event-based computer simulation model of aspect-type experiments strictly satisfying Einstein's locality conditions

    NARCIS (Netherlands)

    De Raedt, Hans; De Raedt, Koen; Michielsen, Kristel; Keimpema, Koenraad; Miyashita, Seiji

    2007-01-01

    Inspired by Einstein-Podolsky-Rosen-Bohtn experiments with photons, we construct an event-based simulation model in which every essential element in the ideal experiment has a counterpart. The model satisfies Einstein's criterion of local causality and does not rely on concepts of quantum and

  2. Employees facing high job demands: How to keep them fit, satisfied, and intrinsically motivated?

    NARCIS (Netherlands)

    Van Yperen, N.W.; Nagao, DH

    2002-01-01

    The purpose of the present research was to determine why some employees faced with high job demands feel fatigued, dissatisfied, and unmotivated, whereas others feel fatigued but satisfied and intrinsically motivated. It is argued and demonstrated that two job conditions, namely job control and job

  3. Social Problem Solving and Depressive Symptoms Over Time: A Randomized Clinical Trial of Cognitive Behavioral Analysis System of Psychotherapy, Brief Supportive Psychotherapy, and Pharmacotherapy

    Science.gov (United States)

    Klein, Daniel N.; Leon, Andrew C.; Li, Chunshan; D’Zurilla, Thomas J.; Black, Sarah R.; Vivian, Dina; Dowling, Frank; Arnow, Bruce A.; Manber, Rachel; Markowitz, John C.; Kocsis, James H.

    2011-01-01

    Objective Depression is associated with poor social problem-solving, and psychotherapies that focus on problem-solving skills are efficacious in treating depression. We examined the associations between treatment, social problem solving, and depression in a randomized clinical trial testing the efficacy of psychotherapy augmentation for chronically depressed patients who failed to fully respond to an initial trial of pharmacotherapy (Kocsis et al., 2009). Method Participants with chronic depression (n = 491) received Cognitive Behavioral Analysis System of Psychotherapy (CBASP), which emphasizes interpersonal problem-solving, plus medication; Brief Supportive Psychotherapy (BSP) plus medication; or medication alone for 12 weeks. Results CBASP plus pharmacotherapy was associated with significantly greater improvement in social problem solving than BSP plus pharmacotherapy, and a trend for greater improvement in problem solving than pharmacotherapy alone. In addition, change in social problem solving predicted subsequent change in depressive symptoms over time. However, the magnitude of the associations between changes in social problem solving and subsequent depressive symptoms did not differ across treatment conditions. Conclusions It does not appear that improved social problem solving is a mechanism that uniquely distinguishes CBASP from other treatment approaches. PMID:21500885

  4. Moment problems and the causal set approach to quantum gravity

    International Nuclear Information System (INIS)

    Ash, Avner; McDonald, Patrick

    2003-01-01

    We study a collection of discrete Markov chains related to the causal set approach to modeling discrete theories of quantum gravity. The transition probabilities of these chains satisfy a general covariance principle, a causality principle, and a renormalizability condition. The corresponding dynamics are completely determined by a sequence of non-negative real coupling constants. Using techniques related to the classical moment problem, we give a complete description of any such sequence of coupling constants. We prove a representation theorem: every discrete theory of quantum gravity arising from causal set dynamics satisfying covariance, causality, and renormalizability corresponds to a unique probability distribution function on the non-negative real numbers, with the coupling constants defining the theory given by the moments of the distribution

  5. Causal holographic information does not satisfy the linearized quantum focusing condition

    Science.gov (United States)

    Fu, Zicao; Marolf, Donald; Qi, Marvin

    2018-04-01

    The Hubeny-Rangamani causal holographic information (CHI) defined by a region R of a holographic quantum field theory (QFT) is a modern version of the idea that the area of event horizons might be related to an entropy. Here the event horizon lives in a dual gravitational bulk theory with Newton's constant G bulk, and the relation involves a factor of 4 G bulk. The fact that CHI is bounded below by the von Neumann entropy S suggests that CHI is coarse-grained. Its properties could thus differ markedly from those of S. In particular, recent results imply that when d ≤ 4 holographic QFTs are perturbatively coupled to d-dimensional gravity, the combined system satisfies the so-called quantum focusing condition (QFC) at leading order in the new gravitational coupling G d when the QFT entropy is taken to be that of von Neumann. However, by studying states dual to spherical bulk (anti-de Sitter) Schwarschild black holes in the conformal frame for which the boundary is a (2 + 1)-dimensional de Sitter space, we find the QFC defined by CHI is violated even when perturbing about a Killing horizon and using a single null congruence. Since it is known that a generalized second law (GSL) holds in this context, our work demonstrates that the QFC is not required in order for an entropy, or an entropy-like quantity, to satisfy such a GSL.

  6. Solving the simple plant location problem using a data correcting approach

    NARCIS (Netherlands)

    Goldengorin, B.; Tijssen, G.A.; Ghosh, D.; Sierksma, G.

    The Data Correcting Algorithm is a branch and bound type algorithm in which the data of a given problem instance is `corrected' at each branching in such a way that the new instance will be as close as possible to a polynomially solvable instance and the result satisfies an acceptable accuracy (the

  7. Secretary Problems: Weights and Discounts

    OpenAIRE

    Babaioff, M.; Dinitz, M.; Gupta, A.; Immorlica, Nicole Simone; Talwar, K.

    2009-01-01

    textabstractThe classical secretary problem studies the problem of selecting online an element (a “secretary”) with maximum value in a randomly ordered sequence. The difficulty lies in the fact that an element must be either selected or discarded upon its arrival, and this decision is irrevocable. Constant-competitive algorithms are known for the classical secretary problems and several variants. We study the following two extensions of the secretary problem: In the discounted secretary probl...

  8. Second-Order Necessary Optimality Conditions for Some State-Constrained Control Problems of Semilinear Elliptic Equations

    International Nuclear Information System (INIS)

    Casas, E.; Troeltzsch, F.

    1999-01-01

    In this paper we are concerned with some optimal control problems governed by semilinear elliptic equations. The case of a boundary control is studied. We consider pointwise constraints on the control and a finite number of equality and inequality constraints on the state. The goal is to derive first- and second-order optimality conditions satisfied by locally optimal solutions of the problem

  9. A Variant of the Topkis-Veinott Method for Solving Inequality Constrained Optimization Problems

    International Nuclear Information System (INIS)

    Birge, J. R.; Qi, L.; Wei, Z.

    2000-01-01

    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) {z } , f 0 (y) ≠ f 0 (z) , where f 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

  10. On the efficiency of a randomized mirror descent algorithm in online optimization problems

    Science.gov (United States)

    Gasnikov, A. V.; Nesterov, Yu. E.; Spokoiny, V. G.

    2015-04-01

    A randomized online version of the mirror descent method is proposed. It differs from the existing versions by the randomization method. Randomization is performed at the stage of the projection of a subgradient of the function being optimized onto the unit simplex rather than at the stage of the computation of a subgradient, which is common practice. As a result, a componentwise subgradient descent with a randomly chosen component is obtained, which admits an online interpretation. This observation, for example, has made it possible to uniformly interpret results on weighting expert decisions and propose the most efficient method for searching for an equilibrium in a zero-sum two-person matrix game with sparse matrix.

  11. A randomized control trial of the effect of yoga on Gunas (personality) and Self esteem in normal healthy volunteers

    OpenAIRE

    Deshpande, Sudheer; Nagendra, H R; Nagarathna, Raghuram

    2009-01-01

    Background/Aims: To study the efficacy of yoga on Gunas (personality) and self esteem in normal adults through a randomized comparative study. Materials and Methods: Of the 1228 persons who attended motivational lectures, 226 subjects aged 18–71 years, of both sexes, who satisfied the inclusion and exclusion criteria, and who consented to participate in the study were randomly allocated into two groups. The Yoga (Y) group practised an integrated yoga module that included asanas, pranayama, me...

  12. Geometric Programming Approach to an Interactive Fuzzy Inventory Problem

    Directory of Open Access Journals (Sweden)

    Nirmal Kumar Mandal

    2011-01-01

    Full Text Available An interactive multiobjective fuzzy inventory problem with two resource constraints is presented in this paper. The cost parameters and index parameters, the storage space, the budgetary cost, and the objective and constraint goals are imprecise in nature. These parameters and objective goals are quantified by linear/nonlinear membership functions. A compromise solution is obtained by geometric programming method. If the decision maker is not satisfied with this result, he/she may try to update the current solution to his/her satisfactory solution. In this way we implement man-machine interactive procedure to solve the problem through geometric programming method.

  13. General inverse problems for regular variation

    DEFF Research Database (Denmark)

    Damek, Ewa; Mikosch, Thomas Valentin; Rosinski, Jan

    2014-01-01

    Regular variation of distributional tails is known to be preserved by various linear transformations of some random structures. An inverse problem for regular variation aims at understanding whether the regular variation of a transformed random object is caused by regular variation of components ...

  14. Efficacy of an internet-based problem-solving training for teachers: results of a randomized controlled trial.

    Science.gov (United States)

    Ebert, David Daniel; Lehr, Dirk; Boß, Leif; Riper, Heleen; Cuijpers, Pim; Andersson, Gerhard; Thiart, Hanne; Heber, Elena; Berking, Matthias

    2014-11-01

    The primary purpose of this randomized controlled trial (RCT) was to evaluate the efficacy of internet-based problem-solving training (iPST) for employees in the educational sector (teachers) with depressive symptoms. The results of training were compared to those of a waitlist control group (WLC). One-hundred and fifty teachers with elevated depressive symptoms (Center for Epidemiologic Studies Depression Scale, CES-D ≥16) were assigned to either the iPST or WLC group. The iPST consisted of five lessons, including problem-solving and rumination techniques. Symptoms were assessed before the intervention began and in follow-up assessments after seven weeks, three months, and six months. The primary outcome was depressive symptom severity (CES-D). Secondary outcomes included general and work-specific self-efficacy, perceived stress, pathological worries, burnout symptoms, general physical and mental health, and absenteeism. iPST participants displayed a significantly greater reduction in depressive symptoms after the intervention (d=0.59, 95% CI 0.26-0.92), after three months (d=0.37, 95% CI 0.05-0.70) and after six months (d=0.38, 95% CI 0.05-0.70) compared to the control group. The iPST participants also displayed significantly higher improvements in secondary outcomes. However, workplace absenteeism was not significantly affected. iPST is effective in reducing symptoms of depression among teachers. Disseminated on a large scale, iPST could contribute to reducing the burden of stress-related mental health problems among teachers. Future studies should evaluate iPST approaches for use in other working populations.

  15. Get the Message: Punishment Is Satisfying If the Transgressor Responds to Its Communicative Intent.

    Science.gov (United States)

    Funk, Friederike; McGeer, Victoria; Gollwitzer, Mario

    2014-08-01

    Results from three studies demonstrate that victims' justice-related satisfaction with punishment is influenced by the kind of feedback they receive from offenders after punishment. In contrast to previous studies that found a discrepancy between anticipated and experienced satisfaction from punishment (Carlsmith, Wilson, & Gilbert, 2008), participants were able to accurately predict their satisfaction when made aware of the presence or absence of offender feedback acknowledging the victim's intent to punish. Results also indicate that victims were most satisfied when offender feedback not only acknowledged the victim's intent to punish but also indicated a positive moral change in the offender's attitude toward wrongdoing. These findings indicate that punishment per se is neither satisfying nor dissatisfying but that it is crucial to take its communicative functions and its effects on the offender into account. Implications for psychological and philosophical theories on punishment motives as well as implications for justice procedures are discussed. © 2014 by the Society for Personality and Social Psychology, Inc.

  16. Secretary Problems: Weights and Discounts

    NARCIS (Netherlands)

    M. Babaioff; M. Dinitz; A. Gupta; N.S. Immorlica (Nicole Simone); K. Talwar

    2009-01-01

    textabstractThe classical secretary problem studies the problem of selecting online an element (a “secretary”) with maximum value in a randomly ordered sequence. The difficulty lies in the fact that an element must be either selected or discarded upon its arrival, and this decision is irrevocable.

  17. Brownian Optimal Stopping and Random Walks

    International Nuclear Information System (INIS)

    Lamberton, D.

    2002-01-01

    One way to compute the value function of an optimal stopping problem along Brownian paths consists of approximating Brownian motion by a random walk. We derive error estimates for this type of approximation under various assumptions on the distribution of the approximating random walk

  18. Counting problems for number rings

    NARCIS (Netherlands)

    Brakenhoff, Johannes Franciscus

    2009-01-01

    In this thesis we look at three counting problems connected to orders in number fields. First we study the probability that for a random polynomial f in Z[X] the ring Z[X]/f is the maximal order in Q[X]/f. Connected to this is the probability that a random polynomial has a squarefree

  19. Problems for the seminar, ICTP, 2007-2008

    International Nuclear Information System (INIS)

    Arnold, V.

    2008-01-01

    The following problems for the ICPT seminar 2007-2008 are specified: topological classification of polynomials; equipartition of indivisible integer vectors; geometrical progressions? fractional parts? equipartitions; statistics of continued fractions of eigenvalues of matrices; growth rate of elements of periodic continued fractions; periods of geometrical progressions of residues; Kolmogorov?s distributions; stochasticity degree of arithmetical progressions of fractional parts; is a generic geometrical progression of fractional parts random?; prime numbers distribution?s randomness; algorithmic unsolvability of problems of higher dimensional continued fractions; periods of continued fractions of roots of quadratic equations; statistics of lengths of periods of continued fractions of quadratic irrational numbers; random matrices? characteristic polynomials distributions

  20. The grasshopper problem

    Science.gov (United States)

    Goulko, Olga; Kent, Adrian

    2017-11-01

    We introduce and physically motivate the following problem in geometric combinatorics, originally inspired by analysing Bell inequalities. A grasshopper lands at a random point on a planar lawn of area 1. It then jumps once, a fixed distance d, in a random direction. What shape should the lawn be to maximize the chance that the grasshopper remains on the lawn after jumping? We show that, perhaps surprisingly, a disc-shaped lawn is not optimal for any d>0. We investigate further by introducing a spin model whose ground state corresponds to the solution of a discrete version of the grasshopper problem. Simulated annealing and parallel tempering searches are consistent with the hypothesis that, for dcogs, where the integer n is close to π (arcsin⁡(√{π }d / 2 )) -1. We find transitions to other shapes for d ≳π-1 / 2.

  1. Inverse problems in ordinary differential equations and applications

    CERN Document Server

    Llibre, Jaume

    2016-01-01

    This book is dedicated to study the inverse problem of ordinary differential equations, that is it focuses in finding all ordinary differential equations that satisfy a given set of properties. The Nambu bracket is the central tool in developing this approach. The authors start characterizing the ordinary differential equations in R^N which have a given set of partial integrals or first integrals. The results obtained are applied first to planar polynomial differential systems with a given set of such integrals, second to solve the 16th Hilbert problem restricted to generic algebraic limit cycles, third for solving the inverse problem for constrained Lagrangian and Hamiltonian mechanical systems, fourth for studying the integrability of a constrained rigid body. Finally the authors conclude with an analysis on nonholonomic mechanics, a generalization of the Hamiltonian principle, and the statement an solution of the inverse problem in vakonomic mechanics.

  2. Random geometry and Yang-Mills theory

    International Nuclear Information System (INIS)

    Froehlich, J.

    1981-01-01

    The author states various problems and discusses a very few preliminary rigorous results in a branch of mathematics and mathematical physics which one might call random (or stochastic) geometry. Furthermore, he points out why random geometry is important in the quantization of Yang-Mills theory. (Auth.)

  3. A new representation of rotational flow fields satisfying Euler's equation of an ideal compressible fluid

    International Nuclear Information System (INIS)

    Kambe, Tsutomu

    2013-01-01

    A new representation of the solution to Euler's equation of motion is presented by using a system of expressions for compressible rotational flows of an ideal fluid. This is regarded as a generalization of Bernoulli's theorem to compressible rotational flows. The present expressions are derived from the variational principle. The action functional for the principle consists of the main terms of the total kinetic, potential and internal energies, together with three additional terms yielding the equations of continuity, entropy and a third term that provides the rotational component of velocity field. The last term has the form of scalar product satisfying gauge symmetry with respect to both translation and rotation. This is a generalization of the Clebsch transformation from a physical point of view. It is verified that the system of new expressions, in fact, satisfies Euler's equation of motion. (paper)

  4. Physical plausibility of cold star models satisfying Karmarkar conditions

    Energy Technology Data Exchange (ETDEWEB)

    Fuloria, Pratibha [Kumaun University, Physics Dept., Almora (India); Pant, Neeraj [N.D.A., Maths Dept., Khadakwasla, Pune (India)

    2017-11-15

    In the present article, we have obtained a new well behaved solution to Einstein's field equations in the background of Karmarkar spacetime. The solution has been used for stellar modelling within the demand of current observational evidences. All the physical parameters are well behaved inside the stellar interior and our model satisfies all the required conditions to be physically realizable. The obtained compactness parameter is within the Buchdahl limit, i.e. 2M/R ≤ 8/9. The TOV equation is well maintained inside the fluid spheres. The stability of the models has been further confirmed by using Herrera's cracking method. The models proposed in the present work are compatible with observational data of compact objects 4U1608-52 and PSRJ1903+327. The necessary graphs have been shown to authenticate the physical viability of our models. (orig.)

  5. Physical plausibility of cold star models satisfying Karmarkar conditions

    International Nuclear Information System (INIS)

    Fuloria, Pratibha; Pant, Neeraj

    2017-01-01

    In the present article, we have obtained a new well behaved solution to Einstein's field equations in the background of Karmarkar spacetime. The solution has been used for stellar modelling within the demand of current observational evidences. All the physical parameters are well behaved inside the stellar interior and our model satisfies all the required conditions to be physically realizable. The obtained compactness parameter is within the Buchdahl limit, i.e. 2M/R ≤ 8/9. The TOV equation is well maintained inside the fluid spheres. The stability of the models has been further confirmed by using Herrera's cracking method. The models proposed in the present work are compatible with observational data of compact objects 4U1608-52 and PSRJ1903+327. The necessary graphs have been shown to authenticate the physical viability of our models. (orig.)

  6. Physical plausibility of cold star models satisfying Karmarkar conditions

    Science.gov (United States)

    Fuloria, Pratibha; Pant, Neeraj

    2017-11-01

    In the present article, we have obtained a new well behaved solution to Einstein's field equations in the background of Karmarkar spacetime. The solution has been used for stellar modelling within the demand of current observational evidences. All the physical parameters are well behaved inside the stellar interior and our model satisfies all the required conditions to be physically realizable. The obtained compactness parameter is within the Buchdahl limit, i.e. 2M/R ≤ 8/9 . The TOV equation is well maintained inside the fluid spheres. The stability of the models has been further confirmed by using Herrera's cracking method. The models proposed in the present work are compatible with observational data of compact objects 4U1608-52 and PSRJ1903+327. The necessary graphs have been shown to authenticate the physical viability of our models.

  7. Using Computer-Generated Random Numbers to Calculate the Lifetime of a Comet.

    Science.gov (United States)

    Danesh, Iraj

    1991-01-01

    An educational technique to calculate the lifetime of a comet using software-generated random numbers is introduced to undergraduate physiques and astronomy students. Discussed are the generation and eligibility of the required random numbers, background literature related to the problem, and the solution to the problem using random numbers.…

  8. The impact of a Housing First randomized controlled trial on substance use problems among homeless individuals with mental illness.

    Science.gov (United States)

    Kirst, Maritt; Zerger, Suzanne; Misir, Vachan; Hwang, Stephen; Stergiopoulos, Vicky

    2015-01-01

    There is strong evidence that Housing First interventions are effective in improving housing stability and quality of life among homeless people with mental illness and addictions. However, there is very little evidence on the effectiveness of Housing First in improving substance use-related outcomes in this population. This study uses a randomized control design to examine the effects of scatter-site Housing First on substance use outcomes in a large urban centre. Substance use outcomes were compared between a Housing First intervention and treatment as usual group in a sample of 575 individuals experiencing homelessness and mental illness, with or without a co-occurring substance use problem, in the At Home/Chez Soi trial in Toronto, Canada. Generalized linear models were used to compare study arms with respect to change in substance use outcomes over time (baseline, 6, 12, 18 and 24 month). At 24 months, participants in the Housing First intervention had significantly greater reductions in number of days experiencing alcohol problems and amount of money spent on alcohol than participants in the Treatment as Usual group. No differences between the study arms in illicit drug outcomes were found at 24 months. These findings show that a Housing First intervention can contribute to reductions in alcohol problems over time. However, the lack of effect of the intervention on illicit drug problems suggests that individuals experiencing homelessness, mental illness and drug problems may need additional supports to reduce use. Current controlled trials ISRCTN42520374. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. An unbiased estimator of the variance of simple random sampling using mixed random-systematic sampling

    OpenAIRE

    Padilla, Alberto

    2009-01-01

    Systematic sampling is a commonly used technique due to its simplicity and ease of implementation. The drawback of this simplicity is that it is not possible to estimate the design variance without bias. There are several ways to circumvent this problem. One method is to suppose that the variable of interest has a random order in the population, so the sample variance of simple random sampling without replacement is used. By means of a mixed random - systematic sample, an unbiased estimator o...

  10. Biased random key genetic algorithm with insertion and gender selection for capacitated vehicle routing problem with time windows

    Science.gov (United States)

    Rochman, Auliya Noor; Prasetyo, Hari; Nugroho, Munajat Tri

    2017-06-01

    Vehicle Routing Problem (VRP) often occurs when the manufacturers need to distribute their product to some customers/outlets. The distribution process is typically restricted by the capacity of the vehicle and the working hours at the distributor. This type of VRP is also known as Capacitated Vehicle Routing Problem with Time Windows (CVRPTW). A Biased Random Key Genetic Algorithm (BRKGA) was designed and coded in MATLAB to solve the CVRPTW case of soft drink distribution. The standard BRKGA was then modified by applying chromosome insertion into the initial population and defining chromosome gender for parent undergoing crossover operation. The performance of the established algorithms was then compared to a heuristic procedure for solving a soft drink distribution. Some findings are revealed (1) the total distribution cost of BRKGA with insertion (BRKGA-I) results in a cost saving of 39% compared to the total cost of heuristic method, (2) BRKGA with the gender selection (BRKGA-GS) could further improve the performance of the heuristic method. However, the BRKGA-GS tends to yield worse results compared to that obtained from the standard BRKGA.

  11. Social welfare in one-sided matchings: Random priority and beyond

    DEFF Research Database (Denmark)

    Filos-Ratsikas, Aris; Frederiksen, Søren Kristoffer Stiil; Zhang, Jie

    2014-01-01

    We study the problem of approximate social welfare maximization (without money) in one-sided matching problems when agents have unrestricted cardinal preferences over a finite set of items. Random priority is a very well-known truthful-in-expectation mechanism for the problem. We prove...... that the approximation ratio of random priority is Theta(n^{-1/2}) while no truthful-in-expectation mechanism can achieve an approximation ratio better than O(n^{-1/2}), where n is the number of agents and items. Furthermore, we prove that the approximation ratio of all ordinal (not necessarily truthful......-in-expectation) mechanisms is upper bounded by O(n^{-1/2}), indicating that random priority is asymptotically the best truthful-in-expectation mechanism and the best ordinal mechanism for the problem....

  12. Alcohol Use and Problems in Mandated College Students: A Randomized Clinical Trial Using Stepped Care

    Science.gov (United States)

    Borsari, Brian; Hustad, John T.P.; Mastroleo, Nadine R.; Tevyaw, Tracy O’Leary; Barnett, Nancy P.; Kahler, Christopher W.; Short, Erica Eaton; Monti, Peter M.

    2012-01-01

    Objective Over the past two decades, colleges and universities have seen a large increase in the number of students referred to the administration for alcohol policies violations. However, a substantial portion of mandated students may not require extensive treatment. Stepped care may maximize treatment efficiency and greatly reduce the demands on campus alcohol programs. Method Participants in the study (N = 598) were college students mandated to attend an alcohol program following a campus-based alcohol citation. All participants received Step 1: a 15-minute Brief Advice session that included the provision of a booklet containing advice to reduce drinking. Participants were assessed six weeks after receiving the Brief Advice, and those who continued to exhibit risky alcohol use (n = 405) were randomized to Step 2, a 60–90 minute brief motivational intervention (BMI) (n = 211) or an assessment-only control (n = 194). Follow-up assessments were conducted 3, 6, and 9 months after Step 2. Results Results indicated that the participants who received a BMI significantly reduced the number of alcohol-related problems compared to those who received assessment-only, despite no significant group differences in alcohol use. In addition, low risk drinkers (n = 102; who reported low alcohol use and related harms at 6-week follow-up and were not randomized to stepped care) showed a stable alcohol use pattern throughout the follow-up period, indicating they required no additional intervention. Conclusion Stepped care is an efficient and cost-effective method to reduce harms associated with alcohol use by mandated students. PMID:22924334

  13. Swarm of bees and particles algorithms in the problem of gradual failure reliability assurance

    Directory of Open Access Journals (Sweden)

    M. F. Anop

    2015-01-01

    Full Text Available Probability-statistical framework of reliability theory uses models based on the chance failures analysis. These models are not functional and do not reflect relation of reliability characteristics to the object performance. At the same time, a significant part of the technical systems failures are gradual failures caused by degradation of the internal parameters of the system under the influence of various external factors.The paper shows how to provide the required level of reliability at the design stage using a functional model of a technical object. Paper describes the method for solving this problem under incomplete initial information, when there is no information about the patterns of technological deviations and degradation parameters, and the considered system model is a \\black box" one.To this end, we formulate the problem of optimal parametric synthesis. It lies in the choice of the nominal values of the system parameters to satisfy the requirements for its operation and take into account the unavoidable deviations of the parameters from their design values during operation. As an optimization criterion in this case we propose to use a deterministic geometric criterion \\reliability reserve", which is the minimum distance measured along the coordinate directions from the nominal parameter value to the acceptability region boundary rather than statistical values.The paper presents the results of the application of heuristic swarm intelligence methods to solve the formulated optimization problem. Efficiency of particle swarm algorithms and swarm of bees one compared with undirected random search algorithm in solving a number of test optimal parametric synthesis problems in three areas: reliability, convergence rate and operating time. The study suggests that the use of a swarm of bees method for solving the problem of the technical systems gradual failure reliability ensuring is preferred because of the greater flexibility of the

  14. Acceptability of a transdermal gel-based male hormonal contraceptive in a randomized controlled trial☆, ☆☆, ★

    Science.gov (United States)

    Roth, Mara Y.; Shih, Grace; Ilani, Niloufar; Wang, Christina; Page, Stephanie T.; Bremner, William J.; Swerdloff, Ronald S.; Sitruk-Ware, Regine; Blithe, Diana L.; Amory, John K.

    2014-01-01

    Objective Fifty percent of pregnancies in the United States are unintended despite numerous contraceptive methods available to women. The only male contraceptive methods, vasectomy and condoms, are used by 10% and 16% of couples, respectively. Prior studies have shown efficacy of male hormonal contraceptives in development, but few have evaluated patient acceptability and potential use if commercially available. The objective of this study is to determine if a transdermal gel-based male hormonal contraceptive regimen, containing testosterone and Nestorone® gels, would be acceptable to study participants as a primary contraceptive method. Study Design As part of a three-arm, 6-month, double-blind, randomized controlled trial of testosterone and nestorone gels at two academic medical centers, subjects completed a questionnaire to assess the acceptability of the regimen. Of the 99 men randomized, 79 provided data for analysis. Results Overall, 56% (44/79) of men were satisfied or extremely satisfied with this gel-based method of contraception, and 51% (40/79) reported that they would recommend this method to others. One third of subjects (26/79) reported that they would use this as their primary method of contraception if it were commercially available today. However, men with concerns about sexually transmitted disease were significantly less satisfied than men without such concerns (p=0.03). Conclusions A majority of the men who volunteered to participate in this trial of an experimental male hormonal contraceptive were satisfied with this transdermal male hormonal contraceptive. If commercially available, a combination of topical nesterone and testosterone gels could provide a reversible, effective method of contraception that is appealing to men. Implications A substantial portion of men report they would use this transdermal male contraceptive regimen if commercially available. This method would provide a novel, reversible method of contraception for men, whose

  15. Discrete random signal processing and filtering primer with Matlab

    CERN Document Server

    Poularikas, Alexander D

    2013-01-01

    Engineers in all fields will appreciate a practical guide that combines several new effective MATLAB® problem-solving approaches and the very latest in discrete random signal processing and filtering.Numerous Useful Examples, Problems, and Solutions - An Extensive and Powerful ReviewWritten for practicing engineers seeking to strengthen their practical grasp of random signal processing, Discrete Random Signal Processing and Filtering Primer with MATLAB provides the opportunity to doubly enhance their skills. The author, a leading expert in the field of electrical and computer engineering, offe

  16. Attention to fat- and thin-related words in body-satisfied and body-dissatisfied women before and after thin model priming

    Science.gov (United States)

    Sears, Christopher R.; Zumbusch, Alicia S.; von Ranson, Kristin M.

    2018-01-01

    Understanding the cognitive processes underlying body dissatisfaction provides important information on the development and perpetuation of eating pathology. Previous research suggests that body-dissatisfied women process weight-related information differently than body-satisfied women, but the precise nature of these processing differences is not yet understood. In this study, eye-gaze tracking was used to measure attention to weight-related words in body-dissatisfied (n = 40) and body-satisfied (n = 38) women, before and after exposure to images of thin fashion models. Participants viewed 8-second displays containing fat-related, thin-related, and neutral words while their eye fixations were tracked and recorded. Based on previous research and theory, we predicted that body-dissatisfied women would attend to fat-related words more than body-satisfied women and would attend to thin-related words less. It was also predicted that exposure to thin model images would increase self-rated body dissatisfaction and heighten group differences in attention. The results indicated that body-dissatisfied women attended to both fat- and thin-related words more than body-satisfied women and that exposure to thin models did not increase this effect. Implications for cognitive models of eating disorders are discussed. PMID:29447251

  17. Bond portfolio's duration and investment term-structure management problem

    OpenAIRE

    Liu, Daobai

    2006-01-01

    In the considered bond market, there are N zero-coupon bonds transacted continuously, which will mature at equally spaced dates. A duration of bond portfolios under stochastic interest rate model is introduced, which provides a measurement for the interest rate risk. Then we consider an optimal bond investment term-structure management problem using this duration as a performance index, and with the short-term interest rate process satisfying some stochastic differential ...

  18. Modular Approach to Therapy for Anxiety, Depression, Trauma, or Conduct Problems in outpatient child and adolescent mental health services in New Zealand: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Lucassen, Mathijs F G; Stasiak, Karolina; Crengle, Sue; Weisz, John R; Frampton, Christopher M A; Bearman, Sarah Kate; Ugueto, Ana M; Herren, Jennifer; Cribb-Su'a, Ainsleigh; Faleafa, Monique; Kingi-'Ulu'ave, Denise; Loy, Jik; Scott, Rebecca M; Hartdegen, Morgyn; Merry, Sally N

    2015-10-12

    Mental health disorders are common and disabling for young people because of the potential to disrupt key developmental tasks. Implementation of evidence-based psychosocial therapies in New Zealand is limited, owing to the inaccessibility, length, and cost of training in these therapies. Furthermore, most therapies address one problem area at a time, although comorbidity and changing clinical needs commonly occur in practice. A more flexible approach is needed. The Modular Approach to Therapy for Children with Anxiety, Depression, Trauma, or Conduct Problems (MATCH-ADTC) is designed to overcome these challenges; it provides a range of treatment modules addressing different problems, within a single training program. A clinical trial of MATCH-ADTC in the USA showed that MATCH-ADTC outperformed usual care and standard evidence-based treatment on several clinical measures. We aim to replicate these findings and evaluate the impact of providing training and supervision in MATCH-ADTC to: (1) improve clinical outcomes for youth attending mental health services; (2) increase the amount of evidence-based therapy content; (3) increase the efficiency of service delivery. This is an assessor-blinded multi-site effectiveness randomized controlled trial. Randomization occurs at two levels: (1) clinicians (≥60) are randomized to intervention or usual care; (2) youth participants (7-14 years old) accepted for treatment in child and adolescent mental health services (with a primary disorder that includes anxiety, depression, trauma-related symptoms, or disruptive behavior) are randomly allocated to receive MATCH-ADTC or usual care. Youth participants are recruited from 'mainstream', Māori-specific, and Pacific-specific child and adolescent mental health services. We originally planned to recruit 400 youth participants, but this has been revised to 200 participants. Centralized computer randomization ensures allocation concealment. The primary outcome measures are: (i) the

  19. An online randomized controlled trial, with or without problem-solving treatment, for long-term cancer survivors after hematopoietic cell transplantation.

    Science.gov (United States)

    Syrjala, Karen L; Yi, Jean C; Artherholt, Samantha B; Romano, Joan M; Crouch, Marie-Laure; Fiscalini, Allison S; Hegel, Mark T; Flowers, Mary E D; Martin, Paul J; Leisenring, Wendy M

    2018-05-05

    This randomized controlled trial examines the efficacy of INSPIRE, an INternet-based Survivorship Program with Information and REsources, with or without problem-solving treatment (PST) telehealth calls, for survivors after hematopoietic cell transplantation (HCT). All adult survivors who met eligibility criteria were approached for consent. Participants completed patient-reported outcomes at baseline and 6 months. Those with baseline impaired scores on one or more of the outcomes were randomized to INSPIRE, INSPIRE + PST, or control with delayed INSPIRE access. Outcomes included Cancer and Treatment Distress, Symptom Checklist-90-R Depression, and Fatigue Symptom Inventory. Planned analyses compared arms for mean change in aggregated impaired outcomes and for proportion of participants improved on each outcome. Of 1306 eligible HCT recipients, 755 (58%) participated, and 344 (45%) had one or more impaired scores at baseline. We found no reduction in aggregated outcomes for either intervention (P > 0.3). In analyses of individual outcomes, participants randomized to INSPIRE + PST were more likely to improve in distress than controls (45 vs. 20%, RR 2.3, CI 1.0, 5.1); those randomized to INSPIRE alone were marginally more likely to improve in distress (40 vs. 20%, RR 2.0, CI 0.9, 4.5). The INSPIRE online intervention demonstrated a marginal benefit for distress that improved with the addition of telehealth PST, particularly for those who viewed the website or were age 40 or older. Online and telehealth programs such as INSPIRE offer opportunities to enhance HCT survivorship outcomes, particularly for mood, though methods would benefit from strategies to improve efficacy.

  20. Disk Density Tuning of a Maximal Random Packing.

    Science.gov (United States)

    Ebeida, Mohamed S; Rushdi, Ahmad A; Awad, Muhammad A; Mahmoud, Ahmed H; Yan, Dong-Ming; English, Shawn A; Owens, John D; Bajaj, Chandrajit L; Mitchell, Scott A

    2016-08-01

    We introduce an algorithmic framework for tuning the spatial density of disks in a maximal random packing, without changing the sizing function or radii of disks. Starting from any maximal random packing such as a Maximal Poisson-disk Sampling (MPS), we iteratively relocate, inject (add), or eject (remove) disks, using a set of three successively more-aggressive local operations. We may achieve a user-defined density, either more dense or more sparse, almost up to the theoretical structured limits. The tuned samples are conflict-free, retain coverage maximality, and, except in the extremes, retain the blue noise randomness properties of the input. We change the density of the packing one disk at a time, maintaining the minimum disk separation distance and the maximum domain coverage distance required of any maximal packing. These properties are local, and we can handle spatially-varying sizing functions. Using fewer points to satisfy a sizing function improves the efficiency of some applications. We apply the framework to improve the quality of meshes, removing non-obtuse angles; and to more accurately model fiber reinforced polymers for elastic and failure simulations.

  1. Random maintenance policies

    CERN Document Server

    Nakagawa, Toshio

    2014-01-01

    Exploring random maintenance models, this book provides an introduction to the implementation of random maintenance, and it is one of the first books to be written on this subject.  It aims to help readers learn new techniques for applying random policies to actual reliability models, and it provides new theoretical analyses of various models including classical replacement, preventive maintenance and inspection policies. These policies are applied to scheduling problems, backup policies of database systems, maintenance policies of cumulative damage models, and reliability of random redundant systems. Reliability theory is a major concern for engineers and managers, and in light of Japan’s recent earthquake, the reliability of large-scale systems has increased in importance. This also highlights the need for a new notion of maintenance and reliability theory, and how this can practically be applied to systems. Providing an essential guide for engineers and managers specializing in reliability maintenance a...

  2. Solving Business Problems Together Case: A Master's Degree Programme in Finland

    Directory of Open Access Journals (Sweden)

    Maria Jakubik

    2017-08-01

    Full Text Available This descriptive, single, intrinsic case study seeks to answer the following questions: Why should business practitioners and educators work together in solving business problems? How are the business problems of companies handled in a master's degree programme in Finland? The case study is based on multiple sources of documents collected and developed during the ten years of the programme. It demonstrates that solving authentic business problems in a learning community of business practitioners, i.e. students, as well as educators, i.e. teachers and thesis advisors, leads to solutions that satisfy practitioners, educators, and the business community. This case is an example of how solving business problems together contributes to the better performance of businesses and a better society in Finland.

  3. Effects of the KEEP Foster Parent Intervention on Child and Sibling Behavior Problems and Parental Stress During a Randomized Implementation Trial.

    Science.gov (United States)

    Price, Joseph M; Roesch, Scott; Walsh, Natalia E; Landsverk, John

    2015-07-01

    Children in foster care are at risk for externalizing behavior problems, which can in turn increase the risk of changes in foster care placement. The KEEP (Keeping Foster Parents Trained and Supported) foster parent training intervention was designed to equip foster parents with strategies for managing externalizing behavior problems. The primary goals of this investigation were to (a) examine the effectiveness of the KEEP intervention in reducing child behavior problems, as delivered by a community agency; (b) determine if the effects of the KEEP intervention generalize to more than one child in the same home; and (c) examine the effectiveness of the KEEP intervention in reducing parental stress associated with child behavior problems. The data from 335 foster and kinship families with children between the ages of 5 and 12 years were analyzed to address these objectives. Families were randomly assigned to the intervention or control condition. The results indicated that the KEEP intervention was effective in reducing child behavior problems when delivered by a community agency. These results expanded prior research on the KEEP intervention, revealing that the intervention was effective in reducing the behavior problems of more than one child in the same household and in reducing parental stress levels associated with the behavioral issues of the focal child. Thus, the KEEP intervention model holds promise for reducing the behavior problems of children in foster care and reducing stress levels of foster and kinship caregivers as it is disseminated and implemented within similar child welfare settings.

  4. Testing random number generators for Monte Carlo applications

    International Nuclear Information System (INIS)

    Sim, L.H.

    1992-01-01

    Central to any system for modelling radiation transport phenomena using Monte Carlo techniques is the method by which pseudo random numbers are generated. This method is commonly referred to as the Random Number Generator (RNG). It is usually a computer implemented mathematical algorithm which produces a series of numbers uniformly distributed on the interval [0,1]. If this series satisfies certain statistical tests for randomness, then for practical purposes the pseudo random numbers in the series can be considered to be random. Tests of this nature are important not only for new RNGs but also to test the implementation of known RNG algorithms in different computer environments. Six RNGs have been tested using six statistical tests and one visual test. The statistical tests are the moments, frequency (digit and number), serial, gap, and poker tests. The visual test is a simple two dimensional ordered pair display. In addition the RNGs have been tested in a specific Monte Carlo application. This type of test is often overlooked, however it is important that in addition to satisfactory performance in statistical tests, the RNG be able to perform effectively in the applications of interest. The RNGs tested here are based on a variety of algorithms, including multiplicative and linear congruential, lagged Fibonacci, and combination arithmetic and lagged Fibonacci. The effect of the Bays-Durham shuffling algorithm on the output of a known bad RNG has also been investigated. 18 refs., 11 tabs., 4 figs. of

  5. Problems with the random number generator RANF implemented on the CDC cyber 205

    Science.gov (United States)

    Kalle, Claus; Wansleben, Stephan

    1984-10-01

    We show that using RANF may lead to wrong results when lattice models are simulated by Monte Carlo methods. We present a shift-register sequence random number generator which generates two random numbers per cycle on a two pipe CDC Cyber 205.

  6. A method for generating reduced-order combustion mechanisms that satisfy the differential entropy inequality

    Science.gov (United States)

    Ream, Allen E.; Slattery, John C.; Cizmas, Paul G. A.

    2018-04-01

    This paper presents a new method for determining the Arrhenius parameters of a reduced chemical mechanism such that it satisfies the second law of thermodynamics. The strategy is to approximate the progress of each reaction in the reduced mechanism from the species production rates of a detailed mechanism by using a linear least squares method. A series of non-linear least squares curve fittings are then carried out to find the optimal Arrhenius parameters for each reaction. At this step, the molar rates of production are written such that they comply with a theorem that provides the sufficient conditions for satisfying the second law of thermodynamics. This methodology was used to modify the Arrhenius parameters for the Westbrook and Dryer two-step mechanism and the Peters and Williams three-step mechanism for methane combustion. Both optimized mechanisms showed good agreement with the detailed mechanism for species mole fractions and production rates of most major species. Both optimized mechanisms showed significant improvement over previous mechanisms in minor species production rate prediction. Both optimized mechanisms produced no violations of the second law of thermodynamics.

  7. A comparative study on generalized model of anisotropic compact star satisfying the Karmarkar condition

    Energy Technology Data Exchange (ETDEWEB)

    Bhar, Piyali [Government General Degree College, Department of Mathematics, Hooghly, West Bengal (India); Singh, Ksh. Newton [National Defence Academy, Department of Physics, Khadakwasla, Pune (India); Sarkar, Nayan; Rahaman, Farook [Jadavpur University, Department of Mathematics, Kolkata (India)

    2017-09-15

    A new solution satisfying the Karmarkar condition is presented here. We were first to have discovered a hypergeometric function metric potential representing embedding class I spacetime. This new solution yields finite values of metric potentials, density, pressure, redshift, etc. and hence a non-singular solution. The solution is well behaved with respect to the parameter n = 12 to n = 24 corresponding to a stable configuration of mass 2.01M {sub CircleDot} and radius 9.1 km. The internal properties of the solution are very different for n = 12 to n = 24; however, the total mass and radius is independent of the parameter n. The energy conditions are also holds good by the solution which thus can represent a physically viable matter distribution. The equilibrium condition and stability are also discussed through TOV-equation, cracking method and Γ > 4/3. The static stability criterion is also well satisfied and the turning point corresponds to 4.46M {sub CircleDot} for a radius of 9.1 km. (orig.)

  8. Random matrix approach to plasmon resonances in the random impedance network model of disordered nanocomposites

    Science.gov (United States)

    Olekhno, N. A.; Beltukov, Y. M.

    2018-05-01

    Random impedance networks are widely used as a model to describe plasmon resonances in disordered metal-dielectric and other two-component nanocomposites. In the present work, the spectral properties of resonances in random networks are studied within the framework of the random matrix theory. We have shown that the appropriate ensemble of random matrices for the considered problem is the Jacobi ensemble (the MANOVA ensemble). The obtained analytical expressions for the density of states in such resonant networks show a good agreement with the results of numerical simulations in a wide range of metal filling fractions 0

  9. Shape functions for separable solutions to cross-field diffusion problems

    International Nuclear Information System (INIS)

    Luning, C.D.; Perry, W.L.

    1984-01-01

    The shape function S(x), which arises in the study of nonlinear diffusion for cross-field diffusion in plasmas, satisfies the equation S''(x)+lambdaa(x)S/sup α/(x) = 0, 0 0. In the cases of physical interest a(x) possesses an integrable singularity at some point in (0,1) but is otherwise continuous. Existence of a positive solution to this problem is established

  10. On criteria for algebraic independence of collections of functions satisfying algebraic difference relations

    Directory of Open Access Journals (Sweden)

    Hiroshi Ogawara

    2017-01-01

    Full Text Available This paper gives conditions for algebraic independence of a collection of functions satisfying a certain kind of algebraic difference relations. As applications, we show algebraic independence of two collections of special functions: (1 Vignéras' multiple gamma functions and derivatives of the gamma function, (2 the logarithmic function, \\(q\\-exponential functions and \\(q\\-polylogarithm functions. In a similar way, we give a generalization of Ostrowski's theorem.

  11. Variations Method to Solve Terminal Problems for the Second Order Systems of Canonical Form with State Constraints

    Directory of Open Access Journals (Sweden)

    T. S. Kasatkina

    2015-01-01

    Full Text Available Terminal control problem with fixed finite time for the second order affine systems with state constraints is considered. A solution of such terminal problem is suggested for the systems with scalar control of regular canonical form.In this article it is shown that the initial terminal problem is equivalent to the problem of auxiliary function search. This function should satisfy some conditions. Such function design consists of two stages. The first stage includes search of function which corresponds the solution of the terminal control problem without state constraints. This function is designed as polynom of the fifth power which depends on time variable. Coefficients of the polynom are defined by boundary conditions. The second stage includes modification of designed function if corresponding to that function trajectory is not satisfied constraints. Modification process is realized by adding to the current function supplementary polynom. Influence of that polynom handles by variation of a parameter value. Modification process can include a few iterations. After process termination continuous control is found. This control is the solution of the initial terminal prUsing presented scheme the terminal control problem for system, which describes oscillations of the mathematical pendulum, is solved. This approach can be used for the solution of terminal control problems with state constraints for affine systems with multi-dimensional control.

  12. Inficon Transpector MPH Mass Spectrometer Random Vibration Test Report

    Science.gov (United States)

    Santiago-Bond, Jo; Captain, Janine

    2015-01-01

    The purpose of this test report is to summarize results from the vibration testing of the INFICON Transpector MPH100M model Mass Spectrometer. It also identifies requirements satisfied, and procedures used in the test. As a payload of Resource Prospector, it is necessary to determine the survivability of the mass spectrometer to proto-qualification level random vibration. Changes in sensitivity of the mass spectrometer can be interpreted as a change in alignment of the instrument. The results of this test will be used to determine any necessary design changes as the team moves forward with flight design.

  13. Numerical method for solving the inverse problem of quantum scattering theory

    International Nuclear Information System (INIS)

    Ajrapetyan, R.G.; Puzynin, I.V.; Zhidkov, E.P.

    1996-01-01

    A new numerical method for solving the problem of the reconstruction of interaction potential by a phase shift given on a set of closed intervals in (l,k)-plane, satisfying certain geometrical 'Staircase Condition', is suggested. The method is based on the Variable Phase Approach and on the modification of the Continuous Analogy of the Newton Method. 22 refs., 1 fig

  14. The IT problems / the year; Norne: Erfaringer etter ett aar

    Energy Technology Data Exchange (ETDEWEB)

    Staerkebye, Jon

    1998-07-01

    This presentation discusses the year 2000 problem as dealt with by Saga. The project ''Year 2000 in Saga Petroleum'' was formally established in December 1997. Its mandate was to identify risk areas and systems related to the date problem and to establish the necessary action to reduce or eliminate the Y2K problems. The target was (1) To be ''Year 2000 Compliant'' for the most critical systems within 1.4.1999, (2) To ensure the continuity of Saga's operational and business management affairs, (3) Priority to health, environment and safety, (4) Authorities and partners should be satisfied with the way Saga carries out the Y2K project work. Few serious problems were detected, but Y2K compliance information was more difficult to obtain than expected. Major suppliers take the problem seriously, but surprisingly many have started late.

  15. Continuous-Time Mean-Variance Portfolio Selection with Random Horizon

    International Nuclear Information System (INIS)

    Yu, Zhiyong

    2013-01-01

    This paper examines the continuous-time mean-variance optimal portfolio selection problem with random market parameters and random time horizon. Treating this problem as a linearly constrained stochastic linear-quadratic optimal control problem, I explicitly derive the efficient portfolios and efficient frontier in closed forms based on the solutions of two backward stochastic differential equations. Some related issues such as a minimum variance portfolio and a mutual fund theorem are also addressed. All the results are markedly different from those in the problem with deterministic exit time. A key part of my analysis involves proving the global solvability of a stochastic Riccati equation, which is interesting in its own right

  16. Continuous-Time Mean-Variance Portfolio Selection with Random Horizon

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhiyong, E-mail: yuzhiyong@sdu.edu.cn [Shandong University, School of Mathematics (China)

    2013-12-15

    This paper examines the continuous-time mean-variance optimal portfolio selection problem with random market parameters and random time horizon. Treating this problem as a linearly constrained stochastic linear-quadratic optimal control problem, I explicitly derive the efficient portfolios and efficient frontier in closed forms based on the solutions of two backward stochastic differential equations. Some related issues such as a minimum variance portfolio and a mutual fund theorem are also addressed. All the results are markedly different from those in the problem with deterministic exit time. A key part of my analysis involves proving the global solvability of a stochastic Riccati equation, which is interesting in its own right.

  17. Source localization in electromyography using the inverse potential problem

    Science.gov (United States)

    van den Doel, Kees; Ascher, Uri M.; Pai, Dinesh K.

    2011-02-01

    We describe an efficient method for reconstructing the activity in human muscles from an array of voltage sensors on the skin surface. MRI is used to obtain morphometric data which are segmented into muscle tissue, fat, bone and skin, from which a finite element model for volume conduction is constructed. The inverse problem of finding the current sources in the muscles is solved using a careful regularization technique which adds a priori information, yielding physically reasonable solutions from among those that satisfy the basic potential problem. Several regularization functionals are considered and numerical experiments on a 2D test model are performed to determine which performs best. The resulting scheme leads to numerical difficulties when applied to large-scale 3D problems. We clarify the nature of these difficulties and provide a method to overcome them, which is shown to perform well in the large-scale problem setting.

  18. Source localization in electromyography using the inverse potential problem

    International Nuclear Information System (INIS)

    Van den Doel, Kees; Ascher, Uri M; Pai, Dinesh K

    2011-01-01

    We describe an efficient method for reconstructing the activity in human muscles from an array of voltage sensors on the skin surface. MRI is used to obtain morphometric data which are segmented into muscle tissue, fat, bone and skin, from which a finite element model for volume conduction is constructed. The inverse problem of finding the current sources in the muscles is solved using a careful regularization technique which adds a priori information, yielding physically reasonable solutions from among those that satisfy the basic potential problem. Several regularization functionals are considered and numerical experiments on a 2D test model are performed to determine which performs best. The resulting scheme leads to numerical difficulties when applied to large-scale 3D problems. We clarify the nature of these difficulties and provide a method to overcome them, which is shown to perform well in the large-scale problem setting

  19. Exactly averaged equations for flow and transport in random media

    International Nuclear Information System (INIS)

    Shvidler, Mark; Karasaki, Kenzi

    2001-01-01

    It is well known that exact averaging of the equations of flow and transport in random porous media can be realized only for a small number of special, occasionally exotic, fields. On the other hand, the properties of approximate averaging methods are not yet fully understood. For example, the convergence behavior and the accuracy of truncated perturbation series. Furthermore, the calculation of the high-order perturbations is very complicated. These problems for a long time have stimulated attempts to find the answer for the question: Are there in existence some exact general and sufficiently universal forms of averaged equations? If the answer is positive, there arises the problem of the construction of these equations and analyzing them. There exist many publications related to these problems and oriented on different applications: hydrodynamics, flow and transport in porous media, theory of elasticity, acoustic and electromagnetic waves in random fields, etc. We present a method of finding the general form of exactly averaged equations for flow and transport in random fields by using (1) an assumption of the existence of Green's functions for appropriate stochastic problems, (2) some general properties of the Green's functions, and (3) the some basic information about the random fields of the conductivity, porosity and flow velocity. We present a general form of the exactly averaged non-local equations for the following cases. 1. Steady-state flow with sources in porous media with random conductivity. 2. Transient flow with sources in compressible media with random conductivity and porosity. 3. Non-reactive solute transport in random porous media. We discuss the problem of uniqueness and the properties of the non-local averaged equations, for the cases with some types of symmetry (isotropic, transversal isotropic, orthotropic) and we analyze the hypothesis of the structure non-local equations in general case of stochastically homogeneous fields. (author)

  20. Well-Posedness of Nonlocal Parabolic Differential Problems with Dependent Operators

    Directory of Open Access Journals (Sweden)

    Allaberen Ashyralyev

    2014-01-01

    Full Text Available The nonlocal boundary value problem for the parabolic differential equation v'(t+A(tv(t=f(t  (0≤t≤T,  v(0=v(λ+φ,  0<λ≤T in an arbitrary Banach space E with the dependent linear positive operator A(t is investigated. The well-posedness of this problem is established in Banach spaces C0β,γ(Eα-β of all Eα-β-valued continuous functions φ(t on [0,T] satisfying a Hölder condition with a weight (t+τγ. New Schauder type exact estimates in Hölder norms for the solution of two nonlocal boundary value problems for parabolic equations with dependent coefficients are established.

  1. Method of interior boundaries in a mixed problem of acoustic scattering

    Directory of Open Access Journals (Sweden)

    P. A. Krutitskii

    1999-01-01

    Full Text Available The mixed problem for the Helmholtz equation in the exterior of several bodies (obstacles is studied in 2 and 3 dimensions. The Dirichlet boundary condition is given on some obstacles and the impedance boundary condition is specified on the rest. The problem is investigated by a special modification of the boundary integral equation method. This modification can be called ‘Method of interior boundaries’, because additional boundaries are introduced inside scattering bodies, where impedance boundary condition is given. The solution of the problem is obtained in the form of potentials on the whole boundary. The density in the potentials satisfies the uniquely solvable Fredholm equation of the second kind and can be computed by standard codes. In fact our method holds for any positive wave numbers. The Neumann, Dirichlet, impedance problems and mixed Dirichlet–Neumann problem are particular cases of our problem.

  2. Uncapacitated facility location problem with self-serving demands

    Directory of Open Access Journals (Sweden)

    E Monabbati

    2013-12-01

    Full Text Available In classical uncapacitated facility location problems (UFLP the goal is to satisfy requirements of some demand points by setting up some servers, among potential facility locations, such that the total cost including service costs and fixed costs are minimized. In this paper a generalization of UFLP is considered in which some demand points, called self-serving, could be served exclusively by a new server at that point. Numerical experiments show that near optimal solutions are achieved by the proposed method.

  3. An Assembly Line Balancing Problem Automotive Cables

    Directory of Open Access Journals (Sweden)

    Triki Hager

    2015-02-01

    Full Text Available In this paper, an Assembly Line Balancing Problem (ALBP is presented in a real-world automotive cables manufacturer company. This company found it necessary to balance its line, since it needs to increase the production rate. In this ALBP, the number of stations is known and the objective is to minimize cycle time where both precedence and zoning constrains must be satisfied. This problem is formulated as a binary linear program (BLP. Since this problem is NP-hard, an innovative Genetic Algorithm (GA is implemented. The full factorial design is used to obtain the better combination GA parameters and a simple convergence experimental study is performed on the stopping criteria to reduce computational time. Comparison of the proposed GA results with CPLEX software shows that, in a reasonable time, the GA generates consistent solutions that are very close to their optimal ones. Therefore, the proposed GA approach is very effective and competitive.

  4. Multimode Resource-Constrained Multiple Project Scheduling Problem under Fuzzy Random Environment and Its Application to a Large Scale Hydropower Construction Project

    Science.gov (United States)

    Xu, Jiuping

    2014-01-01

    This paper presents an extension of the multimode resource-constrained project scheduling problem for a large scale construction project where multiple parallel projects and a fuzzy random environment are considered. By taking into account the most typical goals in project management, a cost/weighted makespan/quality trade-off optimization model is constructed. To deal with the uncertainties, a hybrid crisp approach is used to transform the fuzzy random parameters into fuzzy variables that are subsequently defuzzified using an expected value operator with an optimistic-pessimistic index. Then a combinatorial-priority-based hybrid particle swarm optimization algorithm is developed to solve the proposed model, where the combinatorial particle swarm optimization and priority-based particle swarm optimization are designed to assign modes to activities and to schedule activities, respectively. Finally, the results and analysis of a practical example at a large scale hydropower construction project are presented to demonstrate the practicality and efficiency of the proposed model and optimization method. PMID:24550708

  5. Multimode resource-constrained multiple project scheduling problem under fuzzy random environment and its application to a large scale hydropower construction project.

    Science.gov (United States)

    Xu, Jiuping; Feng, Cuiying

    2014-01-01

    This paper presents an extension of the multimode resource-constrained project scheduling problem for a large scale construction project where multiple parallel projects and a fuzzy random environment are considered. By taking into account the most typical goals in project management, a cost/weighted makespan/quality trade-off optimization model is constructed. To deal with the uncertainties, a hybrid crisp approach is used to transform the fuzzy random parameters into fuzzy variables that are subsequently defuzzified using an expected value operator with an optimistic-pessimistic index. Then a combinatorial-priority-based hybrid particle swarm optimization algorithm is developed to solve the proposed model, where the combinatorial particle swarm optimization and priority-based particle swarm optimization are designed to assign modes to activities and to schedule activities, respectively. Finally, the results and analysis of a practical example at a large scale hydropower construction project are presented to demonstrate the practicality and efficiency of the proposed model and optimization method.

  6. Mental health and lifestyle correlates of sexual problems and sexual satisfaction in heterosexual Hong Kong Chinese population.

    Science.gov (United States)

    Lau, Joseph T F; Kim, Jean H; Tsui, Hi Yi

    2005-12-01

    To examine the lifestyle, mental health, and stress-related factors associated with various types of sexual problems among sexually active, heterosexual Hong Kong residents aged 18 to 59 years. An anonymous, cross-sectional, random telephone survey was conducted using a special, validated, computerized telephone interview method. A total of 1281 men and 2130 women completed the interview (response rate 50.6%). Sexual problems were determined according to the Diagnostic and Statistical Manual (of Mental Disorders) IV definitions. Among the men, multivariate analyses indicated that older age, poor spousal relationship, less exercise, high level of family stress, high level of financial-related stress, and past year substance use were significantly associated with sexual problems (odds ratio [OR] 1.41 to 3.83). Among the women, being married or cohabiting with a partner was positively associated with lubrication problems, lack of orgasm, lack of pleasure, lack of interest (OR 1.43 to 1.73) and negatively associated with pain during intercourse (OR 0.66) and anxiety (OR 0.62). A high level of financial stress and neuroses diagnoses were also associated with various female sexual problems (OR 1.40 to 2.66). Sexual satisfaction was associated with being married/cohabitating (OR 1.94) and negatively associated with a poor spousal relationship, low level of exercise, and a high level of work-related stress among men (OR 0.37 to 0.71). Among women, a poor spousal relationship and high levels of family stress and financial stress were associated with not being satisfied sexually (OR 0.24 to 0.71). Mental health, stress-related factors, and lifestyle factors contribute to sexual problems among Hong Kong Chinese adults. The factors differed between the two sexes.

  7. Solution matching for a three-point boundary-value problem on atime scale

    Directory of Open Access Journals (Sweden)

    Martin Eggensperger

    2004-07-01

    Full Text Available Let $mathbb{T}$ be a time scale such that $t_1, t_2, t_3 in mathbb{T}$. We show the existence of a unique solution for the three-point boundary value problem $$displaylines{ y^{DeltaDeltaDelta}(t = f(t, y(t, y^Delta(t, y^{DeltaDelta}(t, quad t in [t_1, t_3] cap mathbb{T},cr y(t_1 = y_1, quad y(t_2 = y_2, quad y(t_3 = y_3,. }$$ We do this by matching a solution to the first equation satisfying a two-point boundary conditions on $[t_1, t_2] cap mathbb{T}$ with a solution satisfying a two-point boundary conditions on $[t_2, t_3] cap mathbb{T}$.

  8. The uniqueness of the solution for the definite problem of a parabolic variational inequality

    Directory of Open Access Journals (Sweden)

    Liping Song

    2016-12-01

    Full Text Available Abstract The uniqueness of the solution for the definite problem of a parabolic variational inequality is proved. The problem comes from the study of the optimal exercise strategies for the perpetual executive stock options with unrestricted exercise in financial market. Because the variational inequality is degenerate and the obstacle condition contains the partial derivative of an unknown function, it makes the theoretical study of the definite problem of the variational inequality problem very difficult. Firstly, the property which the value function satisfies is derived by applying the Jensen inequality. Then the uniqueness of the solution is proved by using this property and maximum principles.

  9. Physical Principle for Generation of Randomness

    Science.gov (United States)

    Zak, Michail

    2009-01-01

    A physical principle (more precisely, a principle that incorporates mathematical models used in physics) has been conceived as the basis of a method of generating randomness in Monte Carlo simulations. The principle eliminates the need for conventional random-number generators. The Monte Carlo simulation method is among the most powerful computational methods for solving high-dimensional problems in physics, chemistry, economics, and information processing. The Monte Carlo simulation method is especially effective for solving problems in which computational complexity increases exponentially with dimensionality. The main advantage of the Monte Carlo simulation method over other methods is that the demand on computational resources becomes independent of dimensionality. As augmented by the present principle, the Monte Carlo simulation method becomes an even more powerful computational method that is especially useful for solving problems associated with dynamics of fluids, planning, scheduling, and combinatorial optimization. The present principle is based on coupling of dynamical equations with the corresponding Liouville equation. The randomness is generated by non-Lipschitz instability of dynamics triggered and controlled by feedback from the Liouville equation. (In non-Lipschitz dynamics, the derivatives of solutions of the dynamical equations are not required to be bounded.)

  10. Application of the N-quantum approximation method to bound state problems

    International Nuclear Information System (INIS)

    Raychaudhuri, A.

    1977-01-01

    The N-quantum approximation (NQA) method is examined in the light of its application to bound state problems. Bound state wave functions are obtained as expansion coefficients in a truncated Haag expansion. From the equations of motion for the Heisenberg field and the NQA expansion, an equation satisfied by the wave function is derived. Two different bound state systems are considered. In one case, the bound state problem of two identical scalars by scalar exchange is analyzed using the NQA. An integral equation satisfied by the wave function is derived. In the nonrelativistic limit, the equation is shown to reduce to the Schroedinger equation. The equation is solved numerically, and the results compared with those obtained for this system by other methods. The NQA method is also applied to the bound state of two spin 1/2 particles with electromagnetic interaction. The integral equation for the wave function is shown to agree with the corresponding Bethe Salpeter equation in the nonrelativistic limit. Using the Dirac (4 x 4) matrices the wave function is expanded in terms of structure functions and the equation for the wave function is reduced to two disjoint sets of coupled equation for the structure functions

  11. Reduction of the Random Variables of the Turbulent Wind Field

    DEFF Research Database (Denmark)

    Sichani, Mahdi Teimouri; Nielsen, Søren R.K.

    2012-01-01

    .e. Importance Sampling (IS) or Subset Simulation (SS), will be deteriorated on problems with many random variables. The problem with PDEM is that a multidimensional integral has to be carried out over the space defined by the random variables of the system. The numerical procedure requires discretization......Applicability of the Probability Density Evolution Method (PDEM) for realizing evolution of the probability density for the wind turbines has rather strict bounds on the basic number of the random variables involved in the model. The efficiency of most of the Advanced Monte Carlo (AMC) methods, i...... of the integral domain; this becomes increasingly difficult as the dimensions of the integral domain increase. On the other hand efficiency of the AMC methods is closely dependent on the design points of the problem. Presence of many random variables may increase the number of the design points, hence affects...

  12. AN APPLICATION OF FUZZY PROMETHEE METHOD FOR SELECTING OPTIMAL CAR PROBLEM

    Directory of Open Access Journals (Sweden)

    SERKAN BALLI

    2013-06-01

    Full Text Available Most of the economical, industrial, financial or political decision problems are multi-criteria. In these multi criteria problems, optimal selection of alternatives is hard and complex process. Recently, some kinds of methods are improved to solve these problems. Promethee is one of most efficient and easiest method and solves problems that consist quantitative criteria.  However, in daily life, there are criteria which are explained as linguistic and cannot modeled numerical. Hence, Promethee method is incomplete for linguistic criteria which are imprecise. To satisfy this deficiency, fuzzy set approximation can be used. Promethee method, which is extended with using fuzzy inputs, is applied to car selection for seven different cars in same class by using criteria: price, fuel, performance and security. The obtained results are appropriate and consistent.

  13. Graphical analysis of some pseudo-random number generators

    OpenAIRE

    Lewis, Peter A. W.

    1986-01-01

    There exist today many 'good' pseudo-random number generators; the problem is to retrieve them. This document discusses three commonly used pseudo- random number generators, the first being RANDU, a notoriously bad generator, but one which is still occasionally used. The next is the widely used prime modulus, multiplicative congruential generator used in LL-RANDOMII, the Naval Postgraduate School random number package, and the last is the random number generator provided for microcomputers wi...

  14. National Report presented by the Mexican United States to satisfy the compromises of the Nuclear Safety Convention

    International Nuclear Information System (INIS)

    1998-01-01

    In order to satisfy to the compromises derived of the ratification by part of the Mexican Government for the Nuclear Safety Convention it is presented this National Report which is based on the directives proposed as a result of the preparatory meetings held in the IAEA Headquarters in the city of Vienna, Austria. This National Report represents a document summary and activities realized at present in relation with the only nuclear facility in Mexico: the Nuclear Power Plant in Laguna Verde, Veracruz. This report consists of two parts: In the first one it is described how have been satisfied each one of the compromises. The second one talks about the Laws and Regulations on nuclear activities in the country. (Author)

  15. Optimization of structures to satisfy a flutter velocity constraint by use of quadratic equation fitting. M.S. Thesis

    Science.gov (United States)

    Motiwalla, S. K.

    1973-01-01

    Using the first and the second derivative of flutter velocity with respect to the parameters, the velocity hypersurface is made quadratic. This greatly simplifies the numerical procedure developed for determining the values of the design parameters such that a specified flutter velocity constraint is satisfied and the total structural mass is near a relative minimum. A search procedure is presented utilizing two gradient search methods and a gradient projection method. The procedure is applied to the design of a box beam, using finite-element representation. The results indicate that the procedure developed yields substantial design improvement satisfying the specified constraint and does converge to near a local optimum.

  16. Fuzziness and randomness in an optimization framework

    International Nuclear Information System (INIS)

    Luhandjula, M.K.

    1994-03-01

    This paper presents a semi-infinite approach for linear programming in the presence of fuzzy random variable coefficients. As a byproduct a way for dealing with optimization problems including both fuzzy and random data is obtained. Numerical examples are provided for the sake of illustration. (author). 13 refs

  17. When satisfied customers do not return : Variety seeking’s effect on short-and long-term intentions

    NARCIS (Netherlands)

    Sánchez-García, I.; Pieters, R.; Zeelenberg, M.; Bigné, E.

    2012-01-01

    Even satisfied consumers frequently do not come back, which challenges loyalty theory and marketing practice. It is reasoned that variety-seeking tendencies will significantly affect short-term revisit intentions, whereas satisfaction and regret will mostly determine long-term revisit intentions.

  18. Analytic regularity and collocation approximation for elliptic PDEs with random domain deformations

    KAUST Repository

    Castrillon, Julio; Nobile, Fabio; Tempone, Raul

    2016-01-01

    In this work we consider the problem of approximating the statistics of a given Quantity of Interest (QoI) that depends on the solution of a linear elliptic PDE defined over a random domain parameterized by N random variables. The elliptic problem

  19. The Initial and Neumann Boundary Value Problem for a Class Parabolic Monge-Ampère Equation

    Directory of Open Access Journals (Sweden)

    Juan Wang

    2013-01-01

    Full Text Available We consider the existence, uniqueness, and asymptotic behavior of a classical solution to the initial and Neumann boundary value problem for a class nonlinear parabolic equation of Monge-Ampère type. We show that such solution exists for all times and is unique. It converges eventually to a solution that satisfies a Neumann type problem for nonlinear elliptic equation of Monge-Ampère type.

  20. Statistical problems in medical research

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... medical research, there are some common problems in using statistical methodology which may result ... optimal combination of diagnostic tests for osteoporosis .... randomization used include stratification and minimize-.

  1. Randomized Assignments for Barter Exchanges: Fairness vs Efficiency

    DEFF Research Database (Denmark)

    Fang, Wenyi; Filos-Ratsikas, Aris; Frederiksen, Søren Kristoffer Stiil

    2015-01-01

    We study fairness and efficiency properties of randomized algorithms for barter exchanges with direct applications to kidney exchange problems. It is well documented that randomization can serve as a tool to ensure fairness among participants. However, in many applications, practical constraints...

  2. Continuous-Time Classical and Quantum Random Walk on Direct Product of Cayley Graphs

    International Nuclear Information System (INIS)

    Salimi, S.; Jafarizadeh, M. A.

    2009-01-01

    In this paper we define direct product of graphs and give a recipe for obtaining probability of observing particle on vertices in the continuous-time classical and quantum random walk. In the recipe, the probability of observing particle on direct product of graph is obtained by multiplication of probability on the corresponding to sub-graphs, where this method is useful to determining probability of walk on complicated graphs. Using this method, we calculate the probability of continuous-time classical and quantum random walks on many of finite direct product Cayley graphs (complete cycle, complete K n , charter and n-cube). Also, we inquire that the classical state the stationary uniform distribution is reached as t → ∞ but for quantum state is not always satisfied. (general)

  3. Subjective randomness as statistical inference.

    Science.gov (United States)

    Griffiths, Thomas L; Daniels, Dylan; Austerweil, Joseph L; Tenenbaum, Joshua B

    2018-06-01

    Some events seem more random than others. For example, when tossing a coin, a sequence of eight heads in a row does not seem very random. Where do these intuitions about randomness come from? We argue that subjective randomness can be understood as the result of a statistical inference assessing the evidence that an event provides for having been produced by a random generating process. We show how this account provides a link to previous work relating randomness to algorithmic complexity, in which random events are those that cannot be described by short computer programs. Algorithmic complexity is both incomputable and too general to capture the regularities that people can recognize, but viewing randomness as statistical inference provides two paths to addressing these problems: considering regularities generated by simpler computing machines, and restricting the set of probability distributions that characterize regularity. Building on previous work exploring these different routes to a more restricted notion of randomness, we define strong quantitative models of human randomness judgments that apply not just to binary sequences - which have been the focus of much of the previous work on subjective randomness - but also to binary matrices and spatial clustering. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Computer generation of random deviates

    International Nuclear Information System (INIS)

    Cormack, John

    1991-01-01

    The need for random deviates arises in many scientific applications. In medical physics, Monte Carlo simulations have been used in radiology, radiation therapy and nuclear medicine. Specific instances include the modelling of x-ray scattering processes and the addition of random noise to images or curves in order to assess the effects of various processing procedures. Reliable sources of random deviates with statistical properties indistinguishable from true random deviates are a fundamental necessity for such tasks. This paper provides a review of computer algorithms which can be used to generate uniform random deviates and other distributions of interest to medical physicists, along with a few caveats relating to various problems and pitfalls which can occur. Source code listings for the generators discussed (in FORTRAN, Turbo-PASCAL and Data General ASSEMBLER) are available on request from the authors. 27 refs., 3 tabs., 5 figs

  5. Possibility of using sources of vacuum ultraviolet irradiation to solve problems of space material science

    Science.gov (United States)

    Verkhoutseva, E. T.; Yaremenko, E. I.

    1974-01-01

    An urgent problem in space materials science is simulating the interaction of vacuum ultraviolet (VUV) of solar emission with solids in space conditions, that is, producing a light source with a distribution that approximates the distribution of solar energy. Information is presented on the distribution of the energy flux of VUV of solar radiation. Requirements that must be satisfied by the VUV source used for space materials science are formulated, and a critical evaluation is given of the possibilities of using existing sources for space materials science. From this evaluation it was established that none of the sources of VUV satisfies the specific requirements imposed on the simulator of solar radiation. A solution to the problem was found to be in the development of a new type of source based on exciting a supersonic gas jet flowing into vacuum with a sense electron beam. A description of this gas-jet source, along with its spectral and operation characteristics, is presented.

  6. More Similar but Less Satisfying: Comparing Preferences for and the Efficacy of Within- and Cross-Category Substitutes for Food.

    Science.gov (United States)

    Huh, Young Eun; Vosgerau, Joachim; Morewedge, Carey K

    2016-06-01

    When people cannot get what they want, they often satisfy their desire by consuming a substitute. Substitutes can originate from within the taxonomic category of the desired stimulus (i.e., within-category substitutes) or from a different taxonomic category that serves the same basic goal (i.e., cross-category substitutes). Both a store-brand chocolate (within-category substitute) and a granola bar (cross-category substitute), for example, can serve as substitutes for gourmet chocolate. Here, we found that people believe that within-category substitutes, which are more similar to desired stimuli, will more effectively satisfy their cravings than will cross-category substitutes (Experiments 1, 2a, and 2b). However, because within-category substitutes are more similar than cross-category substitutes to desired stimuli, they are more likely to evoke an unanticipated negative contrast effect. As a result, unless substitutes are equivalent in quality to the desired stimulus, cross-category substitutes more effectively satisfy cravings for the desired stimulus (Experiments 3 and 4). © The Author(s) 2016.

  7. Recipes for stable linear embeddings from Hilbert spaces to R^m

    OpenAIRE

    Puy, Gilles; Davies, Michael; Gribonval, Remi

    2017-01-01

    We consider the problem of constructing a linear map from a Hilbert space H (possibly infinite dimensional) to Rm that satisfies a restricted isometry property (RIP) on an arbitrary signal model, i.e., a subset of H. We present a generic framework that handles a large class of low-dimensional subsets but also unstructured and structured linear maps. We provide a simple recipe to prove that a random linear map satisfies a general RIP with high probability. We also describe a generic technique ...

  8. Recipes for stable linear embeddings from Hilbert spaces to R^m

    OpenAIRE

    Puy, Gilles; Davies, Mike; Gribonval, Rémi

    2015-01-01

    We consider the problem of constructing a linear map from a Hilbert space $\\mathcal{H}$ (possibly infinite dimensional) to $\\mathbb{R}^m$ that satisfies a restricted isometry property (RIP) on an arbitrary signal model $\\mathcal{S} \\subset \\mathcal{H}$. We present a generic framework that handles a large class of low-dimensional subsets but also unstructured and structured linear maps. We provide a simple recipe to prove that a random linear map satisfies a general RIP on $\\mathcal{S}$ with h...

  9. Comparative effectiveness of family problem-solving therapy (F-PST for adolescents after traumatic brain injury: Protocol for a randomized, multicenter, clinical trial

    Directory of Open Access Journals (Sweden)

    Brad G. Kurowski

    2018-06-01

    Full Text Available Introduction: The objective of this manuscript is to describe the methodology that will be used to test the comparative effectiveness, feasibility, and acceptability of three formats of family problem solving therapy (F-PST for improving functional outcomes of complicated mild to severe adolescent TBI. Methods: Three-arm comparative effectiveness, randomized clinical trial (RCT design. We describe the protocol of a three-arm RCT comparing the effectiveness of three modalities of F-PST to reduce executive dysfunction and behavior problems following TBI in adolescence. The RCT will compare the relative effectiveness among face-to-face; online and self-directed; and therapist-supported online modes of treatment. Ethics and dissemination: It is anticipated that findings from this work will inform future clinical care practices, with implications for treatment of other patient populations of youth with psychological symptoms arising from neurological conditions. Institutional review board approval will be obtained from all sites prior to commencement of the study. Clinical Trials Registration: NCT:02368366, Keywords: Pediatric traumatic brain injury, Telehealth, Problem solving, Behavior, Executive function

  10. Effectiveness of Parent-Child Interaction Therapy (PCIT in the Treatment of Young Children's Behavior Problems. A Randomized Controlled Study.

    Directory of Open Access Journals (Sweden)

    Åse Bjørseth

    Full Text Available The aim of the present investigation was to compare the effectiveness of Parent-Child Interaction Therapy (PCIT with treatment as usual (TAU in young children who were referred to regular child and adolescent mental health clinics for behavior problems.Eighty-one Norwegian families with two- to seven-year-old children (52 boys who had scored ≥ 120 on the Eyberg Child Behavior Inventory (ECBI were randomly assigned to receive either PCIT or TAU. The families were assessed 6 and 18 months after beginning treatment. Parenting skills were measured using the Dyadic Parent-Child Interaction Coding System (DPICS, and child behavior problems were measured using the ECBI and the Child Behavior Checklist (CBCL.Linear growth curve analyses revealed that the behavior problems of children receiving PCIT improved more compared with children receiving TAU according to mother reports (ECBI d = .64, CBCL d = .61, both p < .05 but not according to father report. Parents also improved with regard to Do and Don't skills (d = 2.58, d = 1.46, respectively, both p ≤ .001. At the 6-month assessment, which often occurred before treatment was finished, children who had received PCIT had lower father-rated ECBI and mother-rated CBCL-scores (p = .06 compared with those who had received TAU. At the 18-month follow-up, the children who had received PCIT showed fewer behavior problems compared with TAU according to mother (d = .37 and father (d = .56 reports on the ECBI and mother reports on the CBCL regarding externalizing problems (d = .39. Parents receiving PCIT developed more favorable Do Skills (6-month d = 1.81; 18-month d = 1.91 and Don't Skills (6-month d = 1.46; 18-month d = 1.42 according to observer ratings on the DPICS compared with those receiving TAU.Children receiving PCIT in regular clinical practice exhibited a greater reduction in behavior problems compared with children receiving TAU, and their parents' parenting skills improved to a greater degree

  11. Independent random sampling methods

    CERN Document Server

    Martino, Luca; Míguez, Joaquín

    2018-01-01

    This book systematically addresses the design and analysis of efficient techniques for independent random sampling. Both general-purpose approaches, which can be used to generate samples from arbitrary probability distributions, and tailored techniques, designed to efficiently address common real-world practical problems, are introduced and discussed in detail. In turn, the monograph presents fundamental results and methodologies in the field, elaborating and developing them into the latest techniques. The theory and methods are illustrated with a varied collection of examples, which are discussed in detail in the text and supplemented with ready-to-run computer code. The main problem addressed in the book is how to generate independent random samples from an arbitrary probability distribution with the weakest possible constraints or assumptions in a form suitable for practical implementation. The authors review the fundamental results and methods in the field, address the latest methods, and emphasize the li...

  12. Community mental health nurses speak out: the critical relationship between emotional wellbeing and satisfying professional practice.

    Science.gov (United States)

    Rose, Jayln; Glass, Nel

    2006-10-01

    The article reports on selected findings of a research study concerning emotional wellbeing and professional nursing practice (Rose 2002). It highlights the relationship between community mental health nurses' and emotional wellbeing, and their capacity to provide satisfying professional nursing practice (Rose 2002). The notion of emotional wellbeing, factors that impacted upon the participants' emotional wellbeing, and the relationship of emotional wellbeing to professional practice were revealed in the study. These findings were based on a qualitative critical feminist research inquiry and specifically, interviews with five women community mental health nurses in Australia. Whilst complex, emotional wellbeing was found to be both implicitly and explicitly linked to the participants intertwined personal and professional experiences. Four key components were identified: the nebulous notion; the stress relationship; the mind, body, spirit connection; and, inner sense of balance. In terms of emotional wellbeing and professional practice, three themes were revealed. These were: being able to speak out (or not); being autonomous (or not) and being satisfied (or not). The authors argue that the emotional wellbeing of nurses working in community mental health settings is critical to satisfying professional practice. Furthermore nursing work involves emotional work which impacts on one's emotional wellbeing and emotional wellbeing is integrally linked to professional practice. It is recommended that health organisations must be pro-active in addressing the emotional needs of nurses to ensure the delivery of health care that is aligned to professional practice. This approach will ensure nurses will feel more recognised and validated in terms of their nursing practice.

  13. Generalized Pattern Search methods for a class of nonsmooth optimization problems with structure

    Science.gov (United States)

    Bogani, C.; Gasparo, M. G.; Papini, A.

    2009-07-01

    We propose a Generalized Pattern Search (GPS) method to solve a class of nonsmooth minimization problems, where the set of nondifferentiability is included in the union of known hyperplanes and, therefore, is highly structured. Both unconstrained and linearly constrained problems are considered. At each iteration the set of poll directions is enforced to conform to the geometry of both the nondifferentiability set and the boundary of the feasible region, near the current iterate. This is the key issue to guarantee the convergence of certain subsequences of iterates to points which satisfy first-order optimality conditions. Numerical experiments on some classical problems validate the method.

  14. 31 CFR 29.312 - All requirements for credit must be satisfied by June 30, 1997.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false All requirements for credit must be satisfied by June 30, 1997. 29.312 Section 29.312 Money and Finance: Treasury Office of the Secretary of the... General Principles for Determining Service Credit to Calculate Federal Benefit Payments § 29.312 All...

  15. Autotransplantation of Odontoma-Associated Impacted Teeth-A Treatment Strategy for Satisfying Immediate Esthetic Demands: A Case Report.

    Science.gov (United States)

    Hwang, Lisa Alice; Kuo, Chih-Yin; Yang, Jung-Wu; Chiang, Wei-Fan

    2017-09-01

    Compound odontomas are common odontogenic tumors associated with permanent tooth impaction in the premaxilla. This report describes the case of a 14-year-old girl with an odontoma-associated impaction over the premaxilla that was treated using autotransplantation to satisfy an immediate esthetic demand. At postoperative follow-up conducted in the 14th month, a satisfactory cosmetic appearance with a healthy periodontal status was observed. In addition, the authors discuss the possible complications of autotransplantation and different treatment strategies for odontoma-associated impaction and for correcting bone defects in this case report. Autotransplantation for treating odontoma-associated impaction can be an alternative solution for satisfying an immediate cosmetic demand and providing a favorable outcome. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  16. Accumulator and random-walk models of psychophysical discrimination: a counter-evaluation.

    Science.gov (United States)

    Vickers, D; Smith, P

    1985-01-01

    In a recent assessment of models of psychophysical discrimination, Heath criticises the accumulator model for its reliance on computer simulation and qualitative evidence, and contrasts it unfavourably with a modified random-walk model, which yields exact predictions, is susceptible to critical test, and is provided with simple parameter-estimation techniques. A counter-evaluation is presented, in which the approximations employed in the modified random-walk analysis are demonstrated to be seriously inaccurate, the resulting parameter estimates to be artefactually determined, and the proposed test not critical. It is pointed out that Heath's specific application of the model is not legitimate, his data treatment inappropriate, and his hypothesis concerning confidence inconsistent with experimental results. Evidence from adaptive performance changes is presented which shows that the necessary assumptions for quantitative analysis in terms of the modified random-walk model are not satisfied, and that the model can be reconciled with data at the qualitative level only by making it virtually indistinguishable from an accumulator process. A procedure for deriving exact predictions for an accumulator process is outlined.

  17. Description of internal flow problems by a boundary integral method with dipole panels

    International Nuclear Information System (INIS)

    Krieg, R.; Hailfinger, G.

    1979-01-01

    In reactor safety studies the failure of single components is postulated or sudden accident loadings are assumed and the consequences are investigated. Often as a first consequence highly transient three dimensional flow problems occur. In contrast to classical flow problems, in most of the above cases the fluid velocities are relatively small whereas the accelerations assume high values. As a consequence both, viscosity effects and dynamic pressures which are proportional to the square of the fluid velocities are usually negligible. For cases, where the excitation times are considerably longer than the times necessary for a wave to traverse characteristic regions of the fluid field, also the fluid compressibility is negligible. Under these conditions boundary integral methods are an appropriate tool to deal with the problem. Flow singularities are distributed over the fluid boundaries in such a way that pressure and velocity fields are obtained which satisfy the boundary conditions. In order to facilitate the numerical treatment the fluid boundaries are approximated by a finite number of panels with uniform singularity distributions on each of them. Consequently the pressure and velocity field of the given problem may be obtained by superposition of the corresponding fields due to these panels with their singularity intensities as unknown factors. Then satisfying the boundary conditions in so many boundary points as panels have been introduced, yields a system of linear equations which in general allows for a unique determination of the unknown intensities. (orig./RW)

  18. The needs of foster children and how to satisfy them : A systematic review of the literature

    NARCIS (Netherlands)

    Steenbakkers, Anne; van der Steen, Steffie; Grietens, Hans

    Family foster care deeply influences the needs of children and how these are satisfied. To increase our knowledge of foster children’s needs and how these are conceptualized, this paper presents a systematic literature review. Sixty- four empirical articles from six databases were reviewed and

  19. Decision support system for the operating room rescheduling problem.

    Science.gov (United States)

    van Essen, J Theresia; Hurink, Johann L; Hartholt, Woutske; van den Akker, Bernd J

    2012-12-01

    Due to surgery duration variability and arrivals of emergency surgeries, the planned Operating Room (OR) schedule is disrupted throughout the day which may lead to a change in the start time of the elective surgeries. These changes may result in undesirable situations for patients, wards or other involved departments, and therefore, the OR schedule has to be adjusted. In this paper, we develop a decision support system (DSS) which assists the OR manager in this decision by providing the three best adjusted OR schedules. The system considers the preferences of all involved stakeholders and only evaluates the OR schedules that satisfy the imposed resource constraints. The decision rules used for this system are based on a thorough analysis of the OR rescheduling problem. We model this problem as an Integer Linear Program (ILP) which objective is to minimize the deviation from the preferences of the considered stakeholders. By applying this ILP to instances from practice, we determined that the given preferences mainly lead to (i) shifting a surgery and (ii) scheduling a break between two surgeries. By using these changes in the DSS, the performed simulation study shows that less surgeries are canceled and patients and wards are more satisfied, but also that the perceived workload of several departments increases to compensate this. The system can also be used to judge the acceptability of a proposed initial OR schedule.

  20. Effect of routine assessment of specific psychosocial problems on personalized communication, counselors’ awareness, and distress levels in cancer genetic counseling practice: a randomized controlled trial.

    Science.gov (United States)

    Eijzenga, Willem; Aaronson, Neil K; Hahn, Daniela E E; Sidharta, Grace N; van der Kolk, Lizet E; Velthuizen, Mary E; Ausems, Margreet G E M; Bleiker, Eveline M A

    2014-09-20

    This study evaluated the efficacy of a cancer genetics–specific questionnaire in facilitating communication about, awareness of, and management of psychosocial problems, as well as in lowering distress levels. Individuals referred to genetic counseling for cancer at two family cancer clinics in The Netherlands were randomly assigned to an intervention or a control group. All participants completed the psychosocial questionnaire before counseling. In the intervention group, the counselors received the results of this questionnaire before the counseling session. All sessions were audiotaped for content analysis. Primary outcomes were the frequency with which psychosocial problems were discussed, the genetic counselors’ awareness of these problems, and their management. Secondary outcomes included cancer worries and psychological distress, duration and dynamics of the counseling, and satisfaction. The frequency with which psychosocial problems were discussed with 246 participating counselees was significantly higher in the intervention group (n = 127) than in the control group (n =119; P = .004), as was the counselors’ awareness of psychosocial problems regarding hereditary predisposition (P cancer (P = .01), and general emotions (P cancer worries (p = .005) and distress (p = .02) after counseling. The routine assessment of psychosocial problems by questionnaire facilitates genetic counselors’ recognition and discussion of their clients’ psychosocial problems and reduces clients’ distress levels.

  1. Random Numbers and Monte Carlo Methods

    Science.gov (United States)

    Scherer, Philipp O. J.

    Many-body problems often involve the calculation of integrals of very high dimension which cannot be treated by standard methods. For the calculation of thermodynamic averages Monte Carlo methods are very useful which sample the integration volume at randomly chosen points. After summarizing some basic statistics, we discuss algorithms for the generation of pseudo-random numbers with given probability distribution which are essential for all Monte Carlo methods. We show how the efficiency of Monte Carlo integration can be improved by sampling preferentially the important configurations. Finally the famous Metropolis algorithm is applied to classical many-particle systems. Computer experiments visualize the central limit theorem and apply the Metropolis method to the traveling salesman problem.

  2. Stochastic Linear Quadratic Optimal Control Problems

    International Nuclear Information System (INIS)

    Chen, S.; Yong, J.

    2001-01-01

    This paper is concerned with the stochastic linear quadratic optimal control problem (LQ problem, for short) for which the coefficients are allowed to be random and the cost functional is allowed to have a negative weight on the square of the control variable. Some intrinsic relations among the LQ problem, the stochastic maximum principle, and the (linear) forward-backward stochastic differential equations are established. Some results involving Riccati equation are discussed as well

  3. Inverse random source scattering for the Helmholtz equation in inhomogeneous media

    Science.gov (United States)

    Li, Ming; Chen, Chuchu; Li, Peijun

    2018-01-01

    This paper is concerned with an inverse random source scattering problem in an inhomogeneous background medium. The wave propagation is modeled by the stochastic Helmholtz equation with the source driven by additive white noise. The goal is to reconstruct the statistical properties of the random source such as the mean and variance from the boundary measurement of the radiated random wave field at multiple frequencies. Both the direct and inverse problems are considered. We show that the direct problem has a unique mild solution by a constructive proof. For the inverse problem, we derive Fredholm integral equations, which connect the boundary measurement of the radiated wave field with the unknown source function. A regularized block Kaczmarz method is developed to solve the ill-posed integral equations. Numerical experiments are included to demonstrate the effectiveness of the proposed method.

  4. Dilemma Produced by Infinity of a Random Walk

    International Nuclear Information System (INIS)

    Li Jing-Hui

    2015-01-01

    We report a dilemma produced by the infinity of a random walk moving along a two-dimensional space sidestep. For this random walk, our investigation shows that using a different model can lead to a different diffusion coefficient of the random walk, which is produced by the infinity of the random walk. The result obtained by us in the present work can serve as a warning to us when we build the models to investigate the corresponding scientific problems. (paper)

  5. Satisfying the diverse development needs of an engineering organization

    International Nuclear Information System (INIS)

    Zarkesh, L.P.

    1991-01-01

    The Engineering Department at Davis-Besse Nuclear Power Station has established an aggressive philosophy for professionally developing their staff. This philosophy has evolved over the last four years into a program with specialized administrative tools which not only satisfies the intent of industry training guidelines, but also accentuates the development of the individual. This program consists of three parts: (1) The Development Program - A program constructed to actively integrate system and applied science courses, management and interpersonal skill courses, design basis courses (e.g., pipe break analysis, support design, etc.) special process courses (e.g., human factors, ALARA, etc.) and external seminars sponsored by industry experts; (2) The Individual Development Plan (IDP) - A documented course of action, developed annually, in which the employee and the line supervisor jointly contribute to the identification of career goals and strategic professional objectives; and (3) The Training Database - A PC database developed to retain and manage course information (e.g., requests, attendance priorities, schedule, history, etc.). The paper describes these three facets of the training program

  6. CONSISTENCY UNDER SAMPLING OF EXPONENTIAL RANDOM GRAPH MODELS.

    Science.gov (United States)

    Shalizi, Cosma Rohilla; Rinaldo, Alessandro

    2013-04-01

    The growing availability of network data and of scientific interest in distributed systems has led to the rapid development of statistical models of network structure. Typically, however, these are models for the entire network, while the data consists only of a sampled sub-network. Parameters for the whole network, which is what is of interest, are estimated by applying the model to the sub-network. This assumes that the model is consistent under sampling , or, in terms of the theory of stochastic processes, that it defines a projective family. Focusing on the popular class of exponential random graph models (ERGMs), we show that this apparently trivial condition is in fact violated by many popular and scientifically appealing models, and that satisfying it drastically limits ERGM's expressive power. These results are actually special cases of more general results about exponential families of dependent random variables, which we also prove. Using such results, we offer easily checked conditions for the consistency of maximum likelihood estimation in ERGMs, and discuss some possible constructive responses.

  7. Cluster randomization and political philosophy.

    Science.gov (United States)

    Chwang, Eric

    2012-11-01

    In this paper, I will argue that, while the ethical issues raised by cluster randomization can be challenging, they are not new. My thesis divides neatly into two parts. In the first, easier part I argue that many of the ethical challenges posed by cluster randomized human subjects research are clearly present in other types of human subjects research, and so are not novel. In the second, more difficult part I discuss the thorniest ethical challenge for cluster randomized research--cases where consent is genuinely impractical to obtain. I argue that once again these cases require no new analytic insight; instead, we should look to political philosophy for guidance. In other words, the most serious ethical problem that arises in cluster randomized research also arises in political philosophy. © 2011 Blackwell Publishing Ltd.

  8. Non-integrability of the generalized spring-pendulum problem

    International Nuclear Information System (INIS)

    Maciejewski, Andrzej J; Przybylska, Maria; Weil, Jacques-Arthur

    2004-01-01

    We investigate a generalization of the three-dimensional spring-pendulum system. The problem depends on two real parameters (k, a), where k is the Young modulus of the spring and a describes the nonlinearity of elastic forces. We show that this system is not integrable when k ≠ -a. We carefully investigated the case k = -a when the necessary condition for integrability given by the Morales-Ruiz-Ramis theory is satisfied. We discuss an application of the higher order variational equations for proving the non-integrability in this case

  9. Cauchy problem for a parabolic equation with Bessel operator and Riemann–Liouville partial derivative

    Directory of Open Access Journals (Sweden)

    Fatima G. Khushtova

    2016-03-01

    Full Text Available In this paper Cauchy problem for a parabolic equation with Bessel operator and with Riemann–Liouville partial derivative is considered. The representation of the solution is obtained in terms of integral transform with Wright function in the kernel. It is shown that when this equation becomes the fractional diffusion equation, obtained solution becomes the solution of Cauchy problem for the corresponding equation. The uniqueness of the solution in the class of functions that satisfy the analogue of Tikhonov condition is proved.

  10. Satisfying STEM Education Using the Arduino Microprocessor in C Programming

    Science.gov (United States)

    Hoffer, Brandyn M.

    There exists a need to promote better Science Technology Engineering and Math (STEM) education at the high school level. To satisfy this need a series of hands-on laboratory assignments were created to be accompanied by 2 educational trainers that contain various electronic components. This project provides an interdisciplinary, hands-on approach to teaching C programming that meets several standards defined by the Tennessee Board of Education. Together the trainers and lab assignments also introduce key concepts in math and science while allowing students hands-on experience with various electronic components. This will allow students to mimic real world applications of using the C programming language while exposing them to technology not currently introduced in many high school classrooms. The developed project is targeted at high school students performing at or above the junior level and uses the Arduino Mega open-source Microprocessor and software as the primary control unit.

  11. Quantum Entanglement Growth under Random Unitary Dynamics

    Directory of Open Access Journals (Sweden)

    Adam Nahum

    2017-07-01

    Full Text Available Characterizing how entanglement grows with time in a many-body system, for example, after a quantum quench, is a key problem in nonequilibrium quantum physics. We study this problem for the case of random unitary dynamics, representing either Hamiltonian evolution with time-dependent noise or evolution by a random quantum circuit. Our results reveal a universal structure behind noisy entanglement growth, and also provide simple new heuristics for the “entanglement tsunami” in Hamiltonian systems without noise. In 1D, we show that noise causes the entanglement entropy across a cut to grow according to the celebrated Kardar-Parisi-Zhang (KPZ equation. The mean entanglement grows linearly in time, while fluctuations grow like (time^{1/3} and are spatially correlated over a distance ∝(time^{2/3}. We derive KPZ universal behavior in three complementary ways, by mapping random entanglement growth to (i a stochastic model of a growing surface, (ii a “minimal cut” picture, reminiscent of the Ryu-Takayanagi formula in holography, and (iii a hydrodynamic problem involving the dynamical spreading of operators. We demonstrate KPZ universality in 1D numerically using simulations of random unitary circuits. Importantly, the leading-order time dependence of the entropy is deterministic even in the presence of noise, allowing us to propose a simple coarse grained minimal cut picture for the entanglement growth of generic Hamiltonians, even without noise, in arbitrary dimensionality. We clarify the meaning of the “velocity” of entanglement growth in the 1D entanglement tsunami. We show that in higher dimensions, noisy entanglement evolution maps to the well-studied problem of pinning of a membrane or domain wall by disorder.

  12. Quantum Entanglement Growth under Random Unitary Dynamics

    Science.gov (United States)

    Nahum, Adam; Ruhman, Jonathan; Vijay, Sagar; Haah, Jeongwan

    2017-07-01

    Characterizing how entanglement grows with time in a many-body system, for example, after a quantum quench, is a key problem in nonequilibrium quantum physics. We study this problem for the case of random unitary dynamics, representing either Hamiltonian evolution with time-dependent noise or evolution by a random quantum circuit. Our results reveal a universal structure behind noisy entanglement growth, and also provide simple new heuristics for the "entanglement tsunami" in Hamiltonian systems without noise. In 1D, we show that noise causes the entanglement entropy across a cut to grow according to the celebrated Kardar-Parisi-Zhang (KPZ) equation. The mean entanglement grows linearly in time, while fluctuations grow like (time )1/3 and are spatially correlated over a distance ∝(time )2/3. We derive KPZ universal behavior in three complementary ways, by mapping random entanglement growth to (i) a stochastic model of a growing surface, (ii) a "minimal cut" picture, reminiscent of the Ryu-Takayanagi formula in holography, and (iii) a hydrodynamic problem involving the dynamical spreading of operators. We demonstrate KPZ universality in 1D numerically using simulations of random unitary circuits. Importantly, the leading-order time dependence of the entropy is deterministic even in the presence of noise, allowing us to propose a simple coarse grained minimal cut picture for the entanglement growth of generic Hamiltonians, even without noise, in arbitrary dimensionality. We clarify the meaning of the "velocity" of entanglement growth in the 1D entanglement tsunami. We show that in higher dimensions, noisy entanglement evolution maps to the well-studied problem of pinning of a membrane or domain wall by disorder.

  13. Social problem-solving among adolescents treated for depression.

    Science.gov (United States)

    Becker-Weidman, Emily G; Jacobs, Rachel H; Reinecke, Mark A; Silva, Susan G; March, John S

    2010-01-01

    Studies suggest that deficits in social problem-solving may be associated with increased risk of depression and suicidality in children and adolescents. It is unclear, however, which specific dimensions of social problem-solving are related to depression and suicidality among youth. Moreover, rational problem-solving strategies and problem-solving motivation may moderate or predict change in depression and suicidality among children and adolescents receiving treatment. The effect of social problem-solving on acute treatment outcomes were explored in a randomized controlled trial of 439 clinically depressed adolescents enrolled in the Treatment for Adolescents with Depression Study (TADS). Measures included the Children's Depression Rating Scale-Revised (CDRS-R), the Suicidal Ideation Questionnaire--Grades 7-9 (SIQ-Jr), and the Social Problem-Solving Inventory-Revised (SPSI-R). A random coefficients regression model was conducted to examine main and interaction effects of treatment and SPSI-R subscale scores on outcomes during the 12-week acute treatment stage. Negative problem orientation, positive problem orientation, and avoidant problem-solving style were non-specific predictors of depression severity. In terms of suicidality, avoidant problem-solving style and impulsiveness/carelessness style were predictors, whereas negative problem orientation and positive problem orientation were moderators of treatment outcome. Implications of these findings, limitations, and directions for future research are discussed. Copyright 2009 Elsevier Ltd. All rights reserved.

  14. Continuous-time quantum algorithms for unstructured problems

    International Nuclear Information System (INIS)

    Hen, Itay

    2014-01-01

    We consider a family of unstructured optimization problems, for which we propose a method for constructing analogue, continuous-time (not necessarily adiabatic) quantum algorithms that are faster than their classical counterparts. In this family of problems, which we refer to as ‘scrambled input’ problems, one has to find a minimum-cost configuration of a given integer-valued n-bit black-box function whose input values have been scrambled in some unknown way. Special cases within this set of problems are Grover’s search problem of finding a marked item in an unstructured database, certain random energy models, and the functions of the Deutsch–Josza problem. We consider a couple of examples in detail. In the first, we provide an O(1) deterministic analogue quantum algorithm to solve the seminal problem of Deutsch and Josza, in which one has to determine whether an n-bit boolean function is constant (gives 0 on all inputs or 1 on all inputs) or balanced (returns 0 on half the input states and 1 on the other half). We also study one variant of the random energy model, and show that, as one might expect, its minimum energy configuration can be found quadratically faster with a quantum adiabatic algorithm than with classical algorithms. (paper)

  15. Perturbation Solutions for Random Linear Structural Systems subject to Random Excitation using Stochastic Differential Equations

    DEFF Research Database (Denmark)

    Köyluoglu, H.U.; Nielsen, Søren R.K.; Cakmak, A.S.

    1994-01-01

    perturbation method using stochastic differential equations. The joint statistical moments entering the perturbation solution are determined by considering an augmented dynamic system with state variables made up of the displacement and velocity vector and their first and second derivatives with respect......The paper deals with the first and second order statistical moments of the response of linear systems with random parameters subject to random excitation modelled as white-noise multiplied by an envelope function with random parameters. The method of analysis is basically a second order...... to the random parameters of the problem. Equations for partial derivatives are obtained from the partial differentiation of the equations of motion. The zero time-lag joint statistical moment equations for the augmented state vector are derived from the Itô differential formula. General formulation is given...

  16. Price sensitive demand with random sales price - a newsboy problem

    Science.gov (United States)

    Sankar Sana, Shib

    2012-03-01

    Up to now, many newsboy problems have been considered in the stochastic inventory literature. Some assume that stochastic demand is independent of selling price (p) and others consider the demand as a function of stochastic shock factor and deterministic sales price. This article introduces a price-dependent demand with stochastic selling price into the classical Newsboy problem. The proposed model analyses the expected average profit for a general distribution function of p and obtains an optimal order size. Finally, the model is discussed for various appropriate distribution functions of p and illustrated with numerical examples.

  17. Application of Fuzzy Optimization to the Orienteering Problem

    Directory of Open Access Journals (Sweden)

    Madhushi Verma

    2015-01-01

    Full Text Available This paper deals with the orienteering problem (OP which is a combination of two well-known problems (i.e., travelling salesman problem and the knapsack problem. OP is an NP-hard problem and is useful in appropriately modeling several challenging applications. As the parameters involved in these applications cannot be measured precisely, depicting them using crisp numbers is unrealistic. Further, the decision maker may be satisfied with graded satisfaction levels of solutions, which cannot be formulated using a crisp program. To deal with the above-stated two issues, we formulate the fuzzy orienteering problem (FOP and provide a method to solve it. Here we state the two necessary conditions of OP of maximizing the total collected score and minimizing the time taken to traverse a path (within the specified time bound as fuzzy goals and the remaining necessary conditions as crisp constraints. Using the max-min formulation of the fuzzy sets obtained from the fuzzy goals, we calculate the fuzzy decision sets (Z and Z∗ that contain the feasible paths and the desirable paths, respectively, along with the degrees to which they are acceptable. To efficiently solve large instances of FOP, we also present a parallel algorithm on CREW PRAM model.

  18. Triple solutions for a Dirichlet boundary value problem involving a perturbed discrete p(k-Laplacian operator

    Directory of Open Access Journals (Sweden)

    Khaleghi Moghadam Mohsen

    2017-08-01

    Full Text Available Triple solutions are obtained for a discrete problem involving a nonlinearly perturbed one-dimensional p(k-Laplacian operator and satisfying Dirichlet boundary conditions. The methods for existence rely on a Ricceri-local minimum theorem for differentiable functionals. Several examples are included to illustrate the main results.

  19. Monomiality principle, Sheffer-type polynomials and the normal ordering problem

    International Nuclear Information System (INIS)

    Penson, K A; Blasiak, P; Dattoli, G; Duchamp, G H E; Horzela, A; Solomon, A I

    2006-01-01

    We solve the boson normal ordering problem for (q(a † )a + v(a † )) n with arbitrary functions q(x) and v(x) and integer n, where a and a † are boson annihilation and creation operators, satisfying [a, a † ] = 1. This consequently provides the solution for the exponential e λ(q(a † )a+v(a † )) generalizing the shift operator. In the course of these considerations we define and explore the monomiality principle and find its representations. We exploit the properties of Sheffer-type polynomials which constitute the inherent structure of this problem. In the end we give some examples illustrating the utility of the method and point out the relation to combinatorial structures

  20. A chance-constrained stochastic approach to intermodal container routing problems.

    Science.gov (United States)

    Zhao, Yi; Liu, Ronghui; Zhang, Xi; Whiteing, Anthony

    2018-01-01

    We consider a container routing problem with stochastic time variables in a sea-rail intermodal transportation system. The problem is formulated as a binary integer chance-constrained programming model including stochastic travel times and stochastic transfer time, with the objective of minimising the expected total cost. Two chance constraints are proposed to ensure that the container service satisfies ship fulfilment and cargo on-time delivery with pre-specified probabilities. A hybrid heuristic algorithm is employed to solve the binary integer chance-constrained programming model. Two case studies are conducted to demonstrate the feasibility of the proposed model and to analyse the impact of stochastic variables and chance-constraints on the optimal solution and total cost.

  1. Complete lift of a structure satisfying FK−(−K+1F=0

    Directory of Open Access Journals (Sweden)

    Lovejoy S. Das

    1992-01-01

    Full Text Available The idea of f-structure manifold on a differentiable manifold was initiated and developed by Yano [1], Ishihara and Yano [2], Goldberg [3] and among others. The horizontal and complete lifts from a differentiable manifold Mn of class C∞ to its cotangent bundles have been studied by Yano and Patterson [4,5]. Yano and Ishihara [6] have studied lifts of an f-structure in the tangent and cotangent bundles. The purpose of this paper is to obtain integrability conditions of a structure satisfying FK−(−K+1F=0 and FW−(−W+1F≠0 for 1

  2. Genetic algorithm parameters tuning for resource-constrained project scheduling problem

    Science.gov (United States)

    Tian, Xingke; Yuan, Shengrui

    2018-04-01

    Project Scheduling Problem (RCPSP) is a kind of important scheduling problem. To achieve a certain optimal goal such as the shortest duration, the smallest cost, the resource balance and so on, it is required to arrange the start and finish of all tasks under the condition of satisfying project timing constraints and resource constraints. In theory, the problem belongs to the NP-hard problem, and the model is abundant. Many combinatorial optimization problems are special cases of RCPSP, such as job shop scheduling, flow shop scheduling and so on. At present, the genetic algorithm (GA) has been used to deal with the classical RCPSP problem and achieved remarkable results. Vast scholars have also studied the improved genetic algorithm for the RCPSP problem, which makes it to solve the RCPSP problem more efficiently and accurately. However, for the selection of the main parameters of the genetic algorithm, there is no parameter optimization in these studies. Generally, we used the empirical method, but it cannot ensure to meet the optimal parameters. In this paper, the problem was carried out, which is the blind selection of parameters in the process of solving the RCPSP problem. We made sampling analysis, the establishment of proxy model and ultimately solved the optimal parameters.

  3. Advances in randomized parallel computing

    CERN Document Server

    Rajasekaran, Sanguthevar

    1999-01-01

    The technique of randomization has been employed to solve numerous prob­ lems of computing both sequentially and in parallel. Examples of randomized algorithms that are asymptotically better than their deterministic counterparts in solving various fundamental problems abound. Randomized algorithms have the advantages of simplicity and better performance both in theory and often in practice. This book is a collection of articles written by renowned experts in the area of randomized parallel computing. A brief introduction to randomized algorithms In the aflalysis of algorithms, at least three different measures of performance can be used: the best case, the worst case, and the average case. Often, the average case run time of an algorithm is much smaller than the worst case. 2 For instance, the worst case run time of Hoare's quicksort is O(n ), whereas its average case run time is only O( n log n). The average case analysis is conducted with an assumption on the input space. The assumption made to arrive at t...

  4. Historians and the Problem of Rights: From the Perspective of Comparative Studies of Legal History

    Institute of Scientific and Technical Information of China (English)

    ChenYing,; ZhaoBaohua; DavidKelly

    2004-01-01

    Selecting the right angle to approach a question is critical for any branch of learning, and it is no accident that today's Chinese historians take the problem of rights as a starting point for their research. When the method chosen answers the question, the research is capable of satisfying practical social development needs.

  5. Greedy Local Search and Vertex Cover in Sparse Random Graphs

    DEFF Research Database (Denmark)

    Witt, Carsten

    2009-01-01

    . This work starts with a rigorous explanation for this claim based on the refined analysis of the Karp-Sipser algorithm by Aronson et al. Subsequently, theoretical supplements are given to experimental studies of search heuristics on random graphs. For c 1, a greedy and randomized local-search heuristic...... finds an optimal cover in polynomial time with a probability arbitrarily close to 1. This behavior relies on the absence of a giant component. As an additional insight into the randomized search, it is shown that the heuristic fails badly also on graphs consisting of a single tree component of maximum......Recently, various randomized search heuristics have been studied for the solution of the minimum vertex cover problem, in particular for sparse random instances according to the G(n, c/n) model, where c > 0 is a constant. Methods from statistical physics suggest that the problem is easy if c

  6. #SochiProblems: Ignorance or Arrogance? / #SochiProblems: ¿ignorancia o arrogancia?

    Directory of Open Access Journals (Sweden)

    Alexander V. Laskin

    2014-10-01

    Full Text Available The study focuses on the twitter conversations about the XXII Winter Olympics Games in Sochi, Russia. Specifically, the study collects and performs content analysis of the tweets tagged with the hashtag #SochiProblems. This study draws a random sample of tweets from every day of the games to achieve a 99% confidence level with 5% confidence interval and uses the framing theory to analyze this sample. The results allow us to determine what substantive and affective frames dominated in the twitter conversations tagged with #SochiProblems hashtag and what was the main focus of the tweets’ content.

  7. Solution verification, goal-oriented adaptive methods for stochastic advection–diffusion problems

    KAUST Repository

    Almeida, Regina C.

    2010-08-01

    A goal-oriented analysis of linear, stochastic advection-diffusion models is presented which provides both a method for solution verification as well as a basis for improving results through adaptation of both the mesh and the way random variables are approximated. A class of model problems with random coefficients and source terms is cast in a variational setting. Specific quantities of interest are specified which are also random variables. A stochastic adjoint problem associated with the quantities of interest is formulated and a posteriori error estimates are derived. These are used to guide an adaptive algorithm which adjusts the sparse probabilistic grid so as to control the approximation error. Numerical examples are given to demonstrate the methodology for a specific model problem. © 2010 Elsevier B.V.

  8. Solution verification, goal-oriented adaptive methods for stochastic advection–diffusion problems

    KAUST Repository

    Almeida, Regina C.; Oden, J. Tinsley

    2010-01-01

    A goal-oriented analysis of linear, stochastic advection-diffusion models is presented which provides both a method for solution verification as well as a basis for improving results through adaptation of both the mesh and the way random variables are approximated. A class of model problems with random coefficients and source terms is cast in a variational setting. Specific quantities of interest are specified which are also random variables. A stochastic adjoint problem associated with the quantities of interest is formulated and a posteriori error estimates are derived. These are used to guide an adaptive algorithm which adjusts the sparse probabilistic grid so as to control the approximation error. Numerical examples are given to demonstrate the methodology for a specific model problem. © 2010 Elsevier B.V.

  9. A Weak Solution of a Stochastic Nonlinear Problem

    Directory of Open Access Journals (Sweden)

    M. L. Hadji

    2015-01-01

    Full Text Available We consider a problem modeling a porous medium with a random perturbation. This model occurs in many applications such as biology, medical sciences, oil exploitation, and chemical engineering. Many authors focused their study mostly on the deterministic case. The more classical one was due to Biot in the 50s, where he suggested to ignore everything that happens at the microscopic level, to apply the principles of the continuum mechanics at the macroscopic level. Here we consider a stochastic problem, that is, a problem with a random perturbation. First we prove a result on the existence and uniqueness of the solution, by making use of the weak formulation. Furthermore, we use a numerical scheme based on finite differences to present numerical results.

  10. Randomization of grab-sampling strategies for estimating the annual exposure of U miners to Rn daughters.

    Science.gov (United States)

    Borak, T B

    1986-04-01

    Periodic grab sampling in combination with time-of-occupancy surveys has been the accepted procedure for estimating the annual exposure of underground U miners to Rn daughters. Temporal variations in the concentration of potential alpha energy in the mine generate uncertainties in this process. A system to randomize the selection of locations for measurement is described which can reduce uncertainties and eliminate systematic biases in the data. In general, a sample frequency of 50 measurements per year is sufficient to satisfy the criteria that the annual exposure be determined in working level months to within +/- 50% of the true value with a 95% level of confidence. Suggestions for implementing this randomization scheme are presented.

  11. Sales plan generation problem on TV broadcasting

    OpenAIRE

    Özlem Cosgun; İlkay Gultas

    2016-01-01

    Major advertisers and/or advertisement agencies purchase hundreds of slots during a given broadcast period. Deterministic optimization approaches have been well developed for the problem of meeting client requests. The challenging task for the academic research currently is to address optimization problem under uncertainty. This paper is concerned with the sales plan generation problem when the audience levels of advertisement slots are random variables with known probability distributions. T...

  12. Alice and Bob will fight: the problem of electing a committee in the presence of candidate interdependence

    NARCIS (Netherlands)

    Uckelman, J.

    2010-01-01

    The problem of electing a committee which satisfies voters is one for which good solutions are scarce. Extending single-winner voting rules to the multi-winner case works well only when voters have no preferential dependencies among candidates for the committee. (Our motivating example is a voter

  13. Branch-and-Cut-and-Price for the Pickup and Delivery Problem with Time Windows

    DEFF Research Database (Denmark)

    Røpke, Stefan; Cordeau, Jean-Francois

    2009-01-01

    In the pickup and delivery problem with time windows (PDPTW), vehicle routes must be designed to satisfy a set of transportation requests, each involving a pickup and a delivery location, under capacity, time window, and precedence constraints. This paper introduces a new branch......-and-cut-and-price algorithm in which lower bounds are computed by solving through column generation the linear programming relaxation of a set partitioning formulation. Two pricing subproblems are considered in the column generation algorithm: an elementary and a non-elementary shortest path problem. Valid inequalities...

  14. Improving Language Comprehension in Preschool Children with Language Difficulties: A Cluster Randomized Trial

    Science.gov (United States)

    Hagen, Åste M.; Melby-Lervåg, Monica; Lervåg, Arne

    2017-01-01

    Background: Children with language comprehension difficulties are at risk of educational and social problems, which in turn impede employment prospects in adulthood. However, few randomized trials have examined how such problems can be ameliorated during the preschool years. Methods: We conducted a cluster randomized trial in 148 preschool…

  15. A NEW VISION IN SALES: SATISFYING CUSTOMER NEEDS AND SOCIAL RESPONSIBILITY

    Directory of Open Access Journals (Sweden)

    Ion Stancu

    2015-09-01

    Full Text Available The new vision in sales requires, among other things, changing the salespeople's position towards the potential client by applying a philosophy that involves taking into consideration the people they come into contact with and providing solutions to address their needs in a disinterested manner, without having to pretend reciprocity. All this must be based on the concept of total sales utility, solutions to solve clients' immediate needs: the urgent ones, those who are directly related to them (financial needs, but also those arising from the use of goods purchased by the seller. The purpose of this article is to analyse how easily we can discover clients' real needs; under what conditions these needs can be satisfied through sales activities, and which the social responsibilities of the salespeople are.

  16. Effects of dependence in high-dimensional multiple testing problems

    Directory of Open Access Journals (Sweden)

    van de Wiel Mark A

    2008-02-01

    Full Text Available Abstract Background We consider effects of dependence among variables of high-dimensional data in multiple hypothesis testing problems, in particular the False Discovery Rate (FDR control procedures. Recent simulation studies consider only simple correlation structures among variables, which is hardly inspired by real data features. Our aim is to systematically study effects of several network features like sparsity and correlation strength by imposing dependence structures among variables using random correlation matrices. Results We study the robustness against dependence of several FDR procedures that are popular in microarray studies, such as Benjamin-Hochberg FDR, Storey's q-value, SAM and resampling based FDR procedures. False Non-discovery Rates and estimates of the number of null hypotheses are computed from those methods and compared. Our simulation study shows that methods such as SAM and the q-value do not adequately control the FDR to the level claimed under dependence conditions. On the other hand, the adaptive Benjamini-Hochberg procedure seems to be most robust while remaining conservative. Finally, the estimates of the number of true null hypotheses under various dependence conditions are variable. Conclusion We discuss a new method for efficient guided simulation of dependent data, which satisfy imposed network constraints as conditional independence structures. Our simulation set-up allows for a structural study of the effect of dependencies on multiple testing criterions and is useful for testing a potentially new method on π0 or FDR estimation in a dependency context.

  17. Solving the uncommon reactor core neutronics problems

    International Nuclear Information System (INIS)

    Vondy, D.R.; Fowler, T.B.

    1980-01-01

    The common reactor core neutronics problems have fundamental neutron space, energy spectrum solutions. Typically the most positive eigenvalue is associated with an all-positive flux for the pseudo-steady-state condition (k/sub eff/), or the critical state is to be effected by selective adjustment of some variable such as the fuel concentration. With sophistication in reactor analysis has come the demand for solutions of other, uncommon neutronics problems. Importance functionss are needed for sensitivity and uncertainty analyses, as for ratios of intergral reaction rates such as the fuel conversion (breeding) ratio. The dominant higher harmonic solution is needed in stability analysis. Typically the desired neutronics solution must contain negative values to qualify as a higher harmonic or to satisfy a fixed source containing negative values. Both regular and adjoint solutions are of interest as are special integrals of the solutions to support analysis

  18. An innovative scintillation process for correcting, cooling, and reducing the randomness of waveforms

    International Nuclear Information System (INIS)

    Shen, J.

    1991-01-01

    Research activities were concentrated on an innovative scintillation technique for high-energy collider detection. Heretofore, scintillation waveform data of high- energy physics events have been problematically random. This paper represents a bottleneck of data flow for the next generation of detectors for proton colliders like SSC or LHC. Prevailing problems to resolve were: additional time walk and jitter resulting from the random hitting positions of particles, increased walk and jitter caused by scintillation photon propagation dispersions, and quantum fluctuations of luminescence. However, these were manageable when the different aspects of randomness had been clarified in increased detail. For this purpose, these three were defined as pseudorandomness, quasi-randomness, and real randomness, respectively. A unique scintillation counter incorporating long scintillators with light guides, a drift chamber, and fast discriminators plus integrators was employed to resolve problems of correcting time walk and reducing the additional jitter by establishing an analytical waveform description of V(t,z) for a measured (z). Resolving problem was accomplished by reducing jitter by compressing V(t,z) with a nonlinear medium, called cooling scintillation. Resolving problem was proposed by orienting molecular and polarizing scintillation through the use of intense magnetic technology, called stabilizing the waveform

  19. A phase 2a randomized, parallel group, dose-ranging study of molindone in children with attention-deficit/hyperactivity disorder and persistent, serious conduct problems.

    Science.gov (United States)

    Stocks, Jennifer Dugan; Taneja, Baldeo K; Baroldi, Paolo; Findling, Robert L

    2012-04-01

    To evaluate safety and tolerability of four doses of immediate-release molindone hydrochloride in children with attention-deficit/hyperactivity disorder (ADHD) and serious conduct problems. This open-label, parallel-group, dose-ranging, multicenter trial randomized children, aged 6-12 years, with ADHD and persistent, serious conduct problems to receive oral molindone thrice daily for 9-12 weeks in four treatment groups: Group 1-10 mg (5 mg if weight conduct problems. Secondary outcome measures included change in Nisonger Child Behavior Rating Form-Typical Intelligence Quotient (NCBRF-TIQ) Conduct Problem subscale scores, change in Clinical Global Impressions-Severity (CGI-S) and -Improvement (CGI-I) subscale scores from baseline to end point, and Swanson, Nolan, and Pelham rating scale-revised (SNAP-IV) ADHD-related subscale scores. The study randomized 78 children; 55 completed the study. Treatment with molindone was generally well tolerated, with no clinically meaningful changes in laboratory or physical examination findings. The most common treatment-related adverse events (AEs) included somnolence (n=9), weight increase (n=8), akathisia (n=4), sedation (n=4), and abdominal pain (n=4). Mean weight increased by 0.54 kg, and mean body mass index by 0.24 kg/m(2). The incidence of AEs and treatment-related AEs increased with increasing dose. NCBRF-TIQ subscale scores improved in all four treatment groups, with 34%, 34%, 32%, and 55% decreases from baseline in groups 1, 2, 3, and 4, respectively. CGI-S and SNAP-IV scores improved over time in all treatment groups, and CGI-I scores improved to the greatest degree in group 4. Molindone at doses of 5-20 mg/day (children weighing <30 kg) and 20-40 mg (≥ 30 kg) was well tolerated, and preliminary efficacy results suggest that molindone produces dose-related behavioral improvements over 9-12 weeks. Additional double-blind, placebo-controlled trials are needed to further investigate molindone in this pediatric population.

  20. RANDOMNUMBERS, Random Number Sequence Generated from Gas Ionisation Chamber Data

    International Nuclear Information System (INIS)

    Frigerio, N.A.; Sanathanan, L.P.; Morley, M.; Tyler, S.A.; Clark, N.A.; Wang, J.

    1989-01-01

    1 - Description of problem or function: RANDOM NUMBERS is a data collection of almost 2.7 million 31-bit random numbers generated by using a high resolution gas ionization detector chamber in conjunction with a 4096-channel multichannel analyzer to record the radioactive decay of alpha particles from a U-235 source. The signals from the decaying alpha particles were fed to the 4096-channel analyzer, and for each channel the frequency of signals registered in a 20,000-microsecond interval was recorded. The parity bits of these frequency counts, 0 for an even count and 1 for and odd count, were then assembled in sequence to form 31-bit random numbers and transcribed onto magnetic tape. This cycle was repeated to obtain the random numbers. 2 - Method of solution: The frequency distribution of counts from the device conforms to the Brockwell-Moyal distribution which takes into account the dead time of the counter. The count data were analyzed and tests for randomness on a sample indicate that the device is a highly reliable source of truly random numbers. 3 - Restrictions on the complexity of the problem: The RANDOM NUMBERS tape contains 2,669,568 31-bit numbers

  1. Analytical vs. Simulation Solution Techniques for Pulse Problems in Non-linear Stochastic Dynamics

    DEFF Research Database (Denmark)

    Iwankiewicz, R.; Nielsen, Søren R. K.

    Advantages and disadvantages of available analytical and simulation techniques for pulse problems in non-linear stochastic dynamics are discussed. First, random pulse problems, both those which do and do not lead to Markov theory, are presented. Next, the analytical and analytically-numerical tec......Advantages and disadvantages of available analytical and simulation techniques for pulse problems in non-linear stochastic dynamics are discussed. First, random pulse problems, both those which do and do not lead to Markov theory, are presented. Next, the analytical and analytically...

  2. Probability problems in seismic risk analysis and load combinations for nuclear power plants

    International Nuclear Information System (INIS)

    George, L.L.

    1983-01-01

    This workshop describes some probability problems in power plant reliability and maintenance analysis. The problems are seismic risk analysis, loss of load probability, load combinations, and load sharing. The seismic risk problem is to compute power plant reliability given an earthquake and the resulting risk. Component survival occurs if its peak random response to the earthquake does not exceed its strength. Power plant survival is a complicated Boolean function of component failures and survivals. The responses and strengths of components are dependent random processes, and the peak responses are maxima of random processes. The resulting risk is the expected cost of power plant failure

  3. ModerateDrinking.com and Moderation Management: Outcomes of a randomized clinical trial with non-dependent problem drinkers1

    Science.gov (United States)

    Hester, Reid K.; Delaney, Harold D.; Campbell, William

    2011-01-01

    Objective To evaluate the effectiveness of a web-based protocol, Moderate Drinking (MD) (www.moderatedrinking.com) combined with use of the online resources of Moderation Management (MM) (www.moderation.org) as opposed to the use of the online resources of MM alone. Method We randomly assigned 80 problem drinkers to either the experimental or control group with follow-ups at 3, 6, and 12 months. Results Seventy-five participants (94%) had outcome data at one or more follow-up points and 59 (73%) were assessed at all three follow-ups. Comparing baseline measures to the average outcomes at follow-ups indicated a significant overall reduction in both groups in alcohol-related problems and consumption variables. Compared to the control group, the experimental group had better outcomes on percent days abstinent (PDA). There was an interaction between intensity of drinking at baseline and treatment in determining outcomes assessing drinking. Less heavy drinkers in the experimental group had better outcomes on log Mean BAC per drinking day compared to the control group. Heavier drinkers did not differentially benefit from the MD program on this measure. Mixed model analyses in general corroborated these outcomes. Conclusion The outcome data provide partial evidence for the effectiveness of the MD web application combined with MM, compared to the effectiveness of the resources available online at MM by themselves. PMID:21319896

  4. Generating and using truly random quantum states in Mathematica

    Science.gov (United States)

    Miszczak, Jarosław Adam

    2012-01-01

    The problem of generating random quantum states is of a great interest from the quantum information theory point of view. In this paper we present a package for Mathematica computing system harnessing a specific piece of hardware, namely Quantis quantum random number generator (QRNG), for investigating statistical properties of quantum states. The described package implements a number of functions for generating random states, which use Quantis QRNG as a source of randomness. It also provides procedures which can be used in simulations not related directly to quantum information processing. Program summaryProgram title: TRQS Catalogue identifier: AEKA_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKA_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 7924 No. of bytes in distributed program, including test data, etc.: 88 651 Distribution format: tar.gz Programming language: Mathematica, C Computer: Requires a Quantis quantum random number generator (QRNG, http://www.idquantique.com/true-random-number-generator/products-overview.html) and supporting a recent version of Mathematica Operating system: Any platform supporting Mathematica; tested with GNU/Linux (32 and 64 bit) RAM: Case dependent Classification: 4.15 Nature of problem: Generation of random density matrices. Solution method: Use of a physical quantum random number generator. Running time: Generating 100 random numbers takes about 1 second, generating 1000 random density matrices takes more than a minute.

  5. Inverse Problem for Two-Dimensional Discrete Schr`dinger Equation

    CERN Document Server

    Serdyukova, S I

    2000-01-01

    For two-dimensional discrete Schroedinger equation the boundary-value problem in rectangle M times N with zero boundary conditions is solved. It's stated in this work, that inverse problem reduces to reconstruction of C symmetric five-diagonal matrix with given spectrum and given first k(M,N), 1<-ksatisfy (N-1)^2 (M-1) additional conditions and N conditions of compatibility. The elements of C together with "lacking" (N-k) components can be determined by solving the system of the additional conditions, the compatibility conditions and the orthonormality conditions coupled with relations determining elements of C matrix by eigenvalues and components of basic eigenvectors. We succeeded to clear the statement of the problem to the end in the process of concrete calculations. Deriving and solving the huge polynomial systems had been perfor...

  6. Fluctuation theory for radiative transfer in random media

    International Nuclear Information System (INIS)

    Bal, Guillaume; Jing Wenjia

    2011-01-01

    We consider the effect of small scale random fluctuations of the constitutive coefficients on boundary measurements of solutions to radiative transfer equations. As the correlation length of the random oscillations tends to zero, the transport solution is well approximated by a deterministic, averaged, solution. In this paper, we analyze the random fluctuations to the averaged solution, which may be interpreted as a central limit correction to homogenization. With the inverse transport problem in mind, we characterize the random structure of the singular components of the transport measurement operator. In regimes of moderate scattering, such components provide stable reconstructions of the constitutive parameters in the transport equation. We show that the random fluctuations strongly depend on the decorrelation properties of the random medium.

  7. Some statistical problems inherent in radioactive-source detection

    International Nuclear Information System (INIS)

    Barnett, C.S.

    1978-01-01

    Some of the statistical questions associated with problems of detecting random-point-process signals embedded in random-point-process noise are examined. An example of such a problem is that of searching for a lost radioactive source with a moving detection system. The emphasis is on theoretical questions, but some experimental and Monte Carlo results are used to test the theoretical results. Several idealized binary decision problems are treated by starting with simple, specific situations and progressing toward more general problems. This sequence of decision problems culminates in the minimum-cost-expectation rule for deciding between two Poisson processes with arbitrary intensity functions. As an example, this rule is then specialized to the detector-passing-a-point-source decision problem. Finally, Monte Carlo techniques are used to develop and test one estimation procedure: the maximum-likelihood estimation of a parameter in the intensity function of a Poisson process. For the Monte Carlo test this estimation procedure is specialized to the detector-passing-a-point-source case. Introductory material from probability theory is included so as to make the report accessible to those not especially conversant with probabilistic concepts and methods. 16 figures

  8. Environmental data quality problems: ''Technical'' vs. ''legal'' defensibility

    International Nuclear Information System (INIS)

    Luker, R.S.; Brooks, M.C.; Stagg, D.D.

    1995-01-01

    Two significant aspects of environmental data quality are currently being emphasized throughout the industry as critical precursors to environmental decision making: technical integrity and legal defensibility. Because audit findings and consequent perceptions by a client often pose more questions than answers--especially with respect to the ''systemic'' nature and significance of problems based on nonstatistical, ad hoc sampling of large programs--quality assurance in environmental restoration must do more than implement traditional administrative controls. A major problem persists in achieving a consensus opinion between quality assurance and technical staff on the significance of various data problems. This case study compares and contrasts ''technical integrity'' and ''legal defensibility'', and provides performance measures developed to optimize both components in a large, complex DOE environmental restoration program. Performance measures of both administrative and technical processes are being used to ensure that conclusions drawn concerning ''systematic'' problems are not premature, and are founded on thorough, representative aspects of the program. Improved methods to reach consensus opinions on environmental decision-making are imperative and environmental data quality, the cornerstone on which the decisions are built, must be not only scientifically solid, but perceived as solid, if stakeholders are to be satisfied

  9. Capacitated arc routing problem and its extensions in waste collection

    International Nuclear Information System (INIS)

    Fadzli, Mohammad; Najwa, Nurul; Luis, Martino

    2015-01-01

    Capacitated arc routing problem (CARP) is the youngest generation of graph theory that focuses on solving the edge/arc routing for optimality. Since many years, operational research devoted to CARP counterpart, known as vehicle routing problem (VRP), which does not fit to several real cases such like waste collection problem and road maintenance. In this paper, we highlighted several extensions of capacitated arc routing problem (CARP) that represents the real-life problem of vehicle operation in waste collection. By purpose, CARP is designed to find a set of routes for vehicles that satisfies all pre-setting constraints in such that all vehicles must start and end at a depot, service a set of demands on edges (or arcs) exactly once without exceeding the capacity, thus the total fleet cost is minimized. We also addressed the differentiation between CARP and VRP in waste collection. Several issues have been discussed including stochastic demands and time window problems in order to show the complexity and importance of CARP in the related industry. A mathematical model of CARP and its new version is presented by considering several factors such like delivery cost, lateness penalty and delivery time

  10. Capacitated arc routing problem and its extensions in waste collection

    Energy Technology Data Exchange (ETDEWEB)

    Fadzli, Mohammad; Najwa, Nurul [Institut Matematik Kejuruteraan, Universiti Malaysia Perlis, Kampus Pauh Putra, 02600 Arau, Perlis (Malaysia); Luis, Martino [Othman Yeop Abdullah Graduate School of Business, Universiti Utara Malaysia, 06010 Sintok, Kedah (Malaysia)

    2015-05-15

    Capacitated arc routing problem (CARP) is the youngest generation of graph theory that focuses on solving the edge/arc routing for optimality. Since many years, operational research devoted to CARP counterpart, known as vehicle routing problem (VRP), which does not fit to several real cases such like waste collection problem and road maintenance. In this paper, we highlighted several extensions of capacitated arc routing problem (CARP) that represents the real-life problem of vehicle operation in waste collection. By purpose, CARP is designed to find a set of routes for vehicles that satisfies all pre-setting constraints in such that all vehicles must start and end at a depot, service a set of demands on edges (or arcs) exactly once without exceeding the capacity, thus the total fleet cost is minimized. We also addressed the differentiation between CARP and VRP in waste collection. Several issues have been discussed including stochastic demands and time window problems in order to show the complexity and importance of CARP in the related industry. A mathematical model of CARP and its new version is presented by considering several factors such like delivery cost, lateness penalty and delivery time.

  11. Problem-solving intervention for caregivers of children with mental health problems.

    Science.gov (United States)

    Gerkensmeyer, Janis E; Johnson, Cynthia S; Scott, Eric L; Oruche, Ukamaka M; Lindsey, Laura M; Austin, Joan K; Perkins, Susan M

    2013-06-01

    Building Our Solutions and Connections (BOSC) focused on enhancing problem-solving skills (PSS) of primary caregivers of children with mental health problems. Aims were determining feasibility, acceptability, and effect size (ES) estimates for depression, burden, personal control, and PSS. Caregivers were randomized to BOSC (n=30) or wait-list control (WLC) groups (n=31). Data were collected at baseline, post-intervention, and 3 and 6 months post-intervention. Three-months post-intervention, ES for burden and personal control were .07 and .08, respectively. ES for depressed caregivers for burden and personal control were 0.14 and 0.19, respectively. Evidence indicates that the intervention had desired effects. Published by Elsevier Inc.

  12. Resolvent-Techniques for Multiple Exercise Problems

    International Nuclear Information System (INIS)

    Christensen, Sören; Lempa, Jukka

    2015-01-01

    We study optimal multiple stopping of strong Markov processes with random refraction periods. The refraction periods are assumed to be exponentially distributed with a common rate and independent of the underlying dynamics. Our main tool is using the resolvent operator. In the first part, we reduce infinite stopping problems to ordinary ones in a general strong Markov setting. This leads to explicit solutions for wide classes of such problems. Starting from this result, we analyze problems with finitely many exercise rights and explain solution methods for some classes of problems with underlying Lévy and diffusion processes, where the optimal characteristics of the problems can be identified more explicitly. We illustrate the main results with explicit examples

  13. Resolvent-Techniques for Multiple Exercise Problems

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, Sören, E-mail: christensen@math.uni-kiel.de [Christian–Albrechts-University in Kiel, Mathematical Institute (Germany); Lempa, Jukka, E-mail: jukka.lempa@hioa.no [Oslo and Akershus University College, School of business, Faculty of Social Sciences (Norway)

    2015-02-15

    We study optimal multiple stopping of strong Markov processes with random refraction periods. The refraction periods are assumed to be exponentially distributed with a common rate and independent of the underlying dynamics. Our main tool is using the resolvent operator. In the first part, we reduce infinite stopping problems to ordinary ones in a general strong Markov setting. This leads to explicit solutions for wide classes of such problems. Starting from this result, we analyze problems with finitely many exercise rights and explain solution methods for some classes of problems with underlying Lévy and diffusion processes, where the optimal characteristics of the problems can be identified more explicitly. We illustrate the main results with explicit examples.

  14. The MIXMAX random number generator

    Science.gov (United States)

    Savvidy, Konstantin G.

    2015-11-01

    In this paper, we study the randomness properties of unimodular matrix random number generators. Under well-known conditions, these discrete-time dynamical systems have the highly desirable K-mixing properties which guarantee high quality random numbers. It is found that some widely used random number generators have poor Kolmogorov entropy and consequently fail in empirical tests of randomness. These tests show that the lowest acceptable value of the Kolmogorov entropy is around 50. Next, we provide a solution to the problem of determining the maximal period of unimodular matrix generators of pseudo-random numbers. We formulate the necessary and sufficient condition to attain the maximum period and present a family of specific generators in the MIXMAX family with superior performance and excellent statistical properties. Finally, we construct three efficient algorithms for operations with the MIXMAX matrix which is a multi-dimensional generalization of the famous cat-map. First, allowing to compute the multiplication by the MIXMAX matrix with O(N) operations. Second, to recursively compute its characteristic polynomial with O(N2) operations, and third, to apply skips of large number of steps S to the sequence in O(N2 log(S)) operations.

  15. Two- and three-index formulations of the minimum cost multicommodity k-splittable flow problem

    DEFF Research Database (Denmark)

    Gamst, Mette; Jensen, Peter Neergaard; Pisinger, David

    2010-01-01

    The multicommodity flow problem (MCFP) considers the efficient routing of commodities from their origins to their destinations subject to capacity restrictions and edge costs. Baier et al. [G. Baier, E. Köhler, M. Skutella, On the k-splittable flow problem, in: 10th Annual European Symposium...... of commodities has to be satisfied at the lowest possible cost. The problem has applications in transportation problems where a number of commodities must be routed, using a limited number of distinct transportation units for each commodity. Based on a three-index formulation by Truffot et al. [J. Truffot, C...... on Algorithms, 2002, 101–113] introduced the maximum flow multicommodity k-splittable flow problem (MCkFP) where each commodity may use at most k paths between its origin and its destination. This paper studies the -hard minimum cost multicommodity k-splittable flow problem (MCMCkFP) in which a given flow...

  16. Network and system diagrams revisited: Satisfying CEA requirements for causality analysis

    International Nuclear Information System (INIS)

    Perdicoulis, Anastassios; Piper, Jake

    2008-01-01

    Published guidelines for Cumulative Effects Assessment (CEA) have called for the identification of cause-and-effect relationships, or causality, challenging researchers to identify methods that can possibly meet CEA's specific requirements. Together with an outline of these requirements from CEA key literature, the various definitions of cumulative effects point to the direction of a method for causality analysis that is visually-oriented and qualitative. This article consequently revisits network and system diagrams, resolves their reported shortcomings, and extends their capabilities with causal loop diagramming methodology. The application of the resulting composite causality analysis method to three Environmental Impact Assessment (EIA) case studies appears to satisfy the specific requirements of CEA regarding causality. Three 'moments' are envisaged for the use of the proposed method: during the scoping stage, during the assessment process, and during the stakeholder participation process

  17. Hierarchical Dobinski-type relations via substitution and the moment problem

    International Nuclear Information System (INIS)

    Penson, K A; Blasiak, P; Duchamp, G; Horzela, A; Solomon, A I

    2004-01-01

    We consider the transformation properties of integer sequences arising from the normal ordering of exponentiated boson ([a, a†] = 1) monomials of the form exp[λ(a†) r a], r = 1, 2, ..., under the composition of their exponential generating functions. They turn out to be of Sheffer type. We demonstrate that two key properties of these sequences remain preserved under substitutional composition: (a) the property of being the solution of the Stieltjes moment problem; and (b) the representation of these sequences through infinite series (Dobinski-type relations). We present a number of examples of such composition satisfying properties (a) and (b). We obtain new Dobinski-type formulae and solve the associated moment problem for several hierarchically defined combinatorial families of sequences

  18. Modeling Nurse Scheduling Problem Using 0-1 Goal Programming A Case Study Of Tafo Government Hospital Kumasi-Ghana

    Directory of Open Access Journals (Sweden)

    Wallace Agyei

    2015-03-01

    Full Text Available Abstract The problem of scheduling nurses at the Out-Patient Department OPD at Tafo Government Hospital Kumasi Ghana is presented. Currently the schedules are prepared by head nurse who performs this difficult and time consuming task by hand. Due to the existence of many constraints the resulting schedule usually does not guarantee the fairness of distribution of work. The problem was formulated as 0-1goal programming model with the of objective of evenly balancing the workload among nurses and satisfying their preferences as much as possible while complying with the legal and working regulations.. The developed model was then solved using LINGO14.0 software. The resulting schedules based on 0-1goal programming model balanced the workload in terms of the distribution of shift duties fairness in terms of the number of consecutive night duties and satisfied the preferences of the nurses. This is an improvement over the schedules done manually.

  19. Intermittency and random matrices

    Science.gov (United States)

    Sokoloff, Dmitry; Illarionov, E. A.

    2015-08-01

    A spectacular phenomenon of intermittency, i.e. a progressive growth of higher statistical moments of a physical field excited by an instability in a random medium, attracted the attention of Zeldovich in the last years of his life. At that time, the mathematical aspects underlying the physical description of this phenomenon were still under development and relations between various findings in the field remained obscure. Contemporary results from the theory of the product of independent random matrices (the Furstenberg theory) allowed the elaboration of the phenomenon of intermittency in a systematic way. We consider applications of the Furstenberg theory to some problems in cosmology and dynamo theory.

  20. Randomized controlled study of MONARC® vs. tension-free vaginal tape obturator (TVT-O®) in the treatment of female urinary incontinence: comparison of 3-year cure rates.

    Science.gov (United States)

    Park, Yoo Jun; Kim, Duk Yoon

    2012-04-01

    Transobturator approaches to midurethral sling surgery are one of the most commonly performed operations for female stress urinary incontinence throughout the world. However, very few results of randomized clinical trials of transobturator midurethral sling surgery (MONARC vs. TVT-O) for the treatment of female urinary incontinence have been reported. In this study, we compared the 3-year follow-up cure rates of these two procedures. From July 2006 to June 2008, 74 patients who had undergone MONARC (35 patients) or TVT-O (39 patients) were included in the study and were analyzed prospectively. The mean follow-up duration of both groups was 39.2 months. Preoperative and postoperative evaluations included physical examination, uroflowmetry and postvoid residual measurement, involuntary urine loss with physical activity, and urinary symptoms. Cure of female urinary incontinence was defined as patient report of no loss of urine upon physical activity. The patients' satisfaction after treatment was rated as very satisfied, satisfied, equivocal, and unsatisfied. Very satisfied and satisfied were considered as the satisfied rate. There were no significant differences in preoperative patient characteristics, postoperative complications, or success rate between the two groups. The cure rate of the MONARC and TVT-O groups was 85.7% and 84.6%, respectively. The patient satisfaction (very satisfied, satisfied) rate of the MONARC and TVT-O groups was 82.8% and 82.1%, respectively. The MONARC and TVT-O procedures were equally efficient for the treatment of female urinary incontinence, with maintenance of high cure rates for 3 years. Longer follow-up is needed to confirm these results.

  1. Are Emotionally Intelligent EFL Teachers More Satisfied Professionally?

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Hekmatzadeh

    2016-03-01

    Full Text Available Despite the fact that Intelligence Quotient (IQ is an important factor in one’s success in terms of working environment, it is believed that emotional quotient or EQ plays a more important role. With that in mind, this study investigated the relationship between emotional intelligence and job satisfaction of English as Foreign Language (EFL teachers who work at private language institutes in Iran/Shiraz. Furthermore, this study tried to answer whether there is a significant difference between emotional intelligence and job satisfaction of Iranian’s EFL teachers in terms of gender.  A 90-item Bar-On questionnaire was used to measure the teachers’ emotional intelligence; also, a modified version of Karavas’s (2010 job satisfaction scale was used to see how satisfied our teachers are with their teaching career. To answer the research question, Pearson Product-Moment Correlation Coefficient statistical test was run. The results showed that there was a positive and significant correlation between emotional intelligence and job satisfaction of EFL teachers in Iran/Shiraz. Furthermore, the results revealed that there was a statistically significant difference in emotional intelligence between EFL male and female teachers, but there was no statistically significant relationship between Iranian EFL teachers’ job satisfaction in terms of gender. Based on our findings, it is suggested that some preparatory courses aiming at enhancing the important psychological traits such as emotional intelligence should be incorporated in educational programs designed for novice teachers so that it will contribute to pedagogical improvement.

  2. A Logical Deduction Based Clause Learning Algorithm for Boolean Satisfiability Problems

    Directory of Open Access Journals (Sweden)

    Qingshan Chen

    2017-01-01

    Full Text Available Clause learning is the key component of modern SAT solvers, while conflict analysis based on the implication graph is the mainstream technology to generate the learnt clauses. Whenever a clause in the clause database is falsified by the current variable assignments, the SAT solver will try to analyze the reason by using different cuts (i.e., the Unique Implication Points on the implication graph. Those schemes reflect only the conflict on the current search subspace, does not reflect the inherent conflict directly involved in the rest space. In this paper, we propose a new advanced clause learning algorithm based on the conflict analysis and the logical deduction, which reconstructs a linear logical deduction by analyzing the relationship of different decision variables between the backjumping level and the current decision level. The logical deduction result is then added into the clause database as a newly learnt clause. The resulting implementation in Minisat improves the state-of-the-art performance in SAT solving.

  3. The aligned K-center problem

    KAUST Repository

    Braß, Peter

    2011-04-01

    In this paper we study several instances of the aligned k-center problem where the goal is, given a set of points S in the plane and a parameter k ≥ 1, to find k disks with centers on a line ℓ such that their union covers S and the maximum radius of the disks is minimized. This problem is a constrained version of the well-known k-center problem in which the centers are constrained to lie in a particular region such as a segment, a line, or a polygon. We first consider the simplest version of the problem where the line ℓ is given in advance; we can solve this problem in time O(n log2 n). In the case where only the direction of ℓ is fixed, we give an O(n2 log 2 n)-time algorithm. When ℓ is an arbitrary line, we give a randomized algorithm with expected running time O(n4 log2 n). Then we present (1+ε)-approximation algorithms for these three problems. When we denote T(k, ε) = (k/ε2+(k/ε) log k) log(1/ε), these algorithms run in O(n log k + T(k, ε)) time, O(n log k + T(k, ε)/ε) time, and O(n log k + T(k, ε)/ε2) time, respectively. For k = O(n1/3/log n), we also give randomized algorithms with expected running times O(n + (k/ε2) log(1/ε)), O(n+(k/ε3) log(1/ε)), and O(n + (k/ε4) log(1/ε)), respectively. © 2011 World Scientific Publishing Company.

  4. Monte Carlo learning/biasing experiment with intelligent random numbers

    International Nuclear Information System (INIS)

    Booth, T.E.

    1985-01-01

    A Monte Carlo learning and biasing technique is described that does its learning and biasing in the random number space rather than the physical phase-space. The technique is probably applicable to all linear Monte Carlo problems, but no proof is provided here. Instead, the technique is illustrated with a simple Monte Carlo transport problem. Problems encountered, problems solved, and speculations about future progress are discussed. 12 refs

  5. Problem-Solving Therapy During Outpatient Stroke Rehabilitation Improves Coping and Health-Related Quality of Life: Randomized Controlled Trial.

    Science.gov (United States)

    Visser, Marieke M; Heijenbrok-Kal, Majanka H; Van't Spijker, Adriaan; Lannoo, Engelien; Busschbach, Jan J V; Ribbers, Gerard M

    2016-01-01

    This study investigated whether problem-solving therapy (PST) is an effective group intervention for improving coping strategy and health-related quality of life (HRQoL) in patients with stroke. In this multicenter randomized controlled trial, the intervention group received PST as add-on to standard outpatient rehabilitation, the control group received outpatient rehabilitation only. Measurements were performed at baseline, directly after the intervention, and 6 and 12 months later. Data were analyzed using linear-mixed models. Primary outcomes were task-oriented coping as measured by the Coping Inventory for Stressful Situations and psychosocial HRQoL as measured by the Stroke-Specific Quality of Life Scale. Secondary outcomes were the EuroQol EQ-5D-5L utility score, emotion-oriented and avoidant coping as measured by the Coping Inventory for Stressful Situations, problem-solving skills as measured by the Social Problem Solving Inventory-Revised, and depression as measured by the Center for Epidemiological Studies Depression Scale. Included were 166 patients with stroke, mean age 53.06 years (SD, 10.19), 53% men, median time poststroke 7.29 months (interquartile range, 4.90-10.61 months). Six months post intervention, the PST group showed significant improvement when compared with the control group in task-oriented coping (P=0.008), but not stroke-specific psychosocial HRQoL. Furthermore, avoidant coping (P=0.039) and the utility value for general HRQoL (P=0.034) improved more in the PST group than in the control after 6 months. PST seems to improve task-oriented coping but not disease-specific psychosocial HRQoL after stroke >6-month follow-up. Furthermore, we found indications that PST may improve generic HRQoL recovery and avoidant coping. URL: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2509. Unique identifier: CNTR2509. © 2015 American Heart Association, Inc.

  6. Two-Level Adaptive Algebraic Multigrid for a Sequence of Problems with Slowly Varying Random Coefficients [Adaptive Algebraic Multigrid for Sequence of Problems with Slowly Varying Random Coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Kalchev, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ketelsen, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, P. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-11-07

    Our paper proposes an adaptive strategy for reusing a previously constructed coarse space by algebraic multigrid to construct a two-level solver for a problem with nearby characteristics. Furthermore, a main target application is the solution of the linear problems that appear throughout a sequence of Markov chain Monte Carlo simulations of subsurface flow with uncertain permeability field. We demonstrate the efficacy of the method with extensive set of numerical experiments.

  7. Privacy preserving randomized gossip algorithms

    KAUST Repository

    Hanzely, Filip; Konečný , Jakub; Loizou, Nicolas; Richtarik, Peter; Grishchenko, Dmitry

    2017-01-01

    In this work we present three different randomized gossip algorithms for solving the average consensus problem while at the same time protecting the information about the initial private values stored at the nodes. We give iteration complexity bounds for all methods, and perform extensive numerical experiments.

  8. Privacy preserving randomized gossip algorithms

    KAUST Repository

    Hanzely, Filip

    2017-06-23

    In this work we present three different randomized gossip algorithms for solving the average consensus problem while at the same time protecting the information about the initial private values stored at the nodes. We give iteration complexity bounds for all methods, and perform extensive numerical experiments.

  9. Reduction in 2-year recurrent risk score and improved behavioral outcomes after participation in the "Beating Heart Problems" self-management program: results of a randomized controlled trial.

    Science.gov (United States)

    Murphy, Barbara M; Worcester, Marian U C; Higgins, Rosemary O; Elliott, Peter C; Le Grande, Michael R; Mitchell, Fiona; Navaratnam, Hema; Turner, Alyna; Grigg, Leeanne; Tatoulis, James; Goble, Alan J

    2013-01-01

    While behavior change can improve risk factor profiles and prognosis after an acute cardiac event, patients need assistance to achieve sustained lifestyle changes. We developed the "Beating Heart Problems" cognitive-behavioral therapy and motivational interviewing program to support patients to develop behavioral and cognitive self-management skills. We report the results of a randomized controlled trial of the program. Patients (n = 275) consecutively admitted to 2 Melbourne hospitals after acute myocardial infarction (32%), coronary artery bypass graft surgery (40%), or percutaneous coronary intervention (28%) were randomized to treatment (T; n = 139) or control (C; n = 136). T group patients were invited to participate in the 8-week group-based program. Patients underwent risk factor screening 6 weeks after hospital discharge (before randomization) and again 4 and 12 months later. At both the followups, T and C groups were compared on 2-year risk of a recurrent cardiac event and key behavioral outcomes, using both intention-to-treat and "completers only" analyses. Patients ranged in age from 32 to 75 years (mean = 59.0 years; SD - 9.1 years). Most patients (86%) were men. Compared with the C group patients, T group patients tended toward greater reduction in 2-year risk, at both the 4- and 12-month followups. Significant benefits in dietary fat intake and functional capacity were also evident. The "Beating Heart Problems" program showed modest but important benefit over usual care at 4 and, to a lesser extent, 12 months. Modifications to the program such as the inclusion of booster sessions and translation to online delivery are likely to improve outcomes.

  10. Simulating quantum correlations as a distributed sampling problem

    International Nuclear Information System (INIS)

    Degorre, Julien; Laplante, Sophie; Roland, Jeremie

    2005-01-01

    It is known that quantum correlations exhibited by a maximally entangled qubit pair can be simulated with the help of shared randomness, supplemented with additional resources, such as communication, postselection or nonlocal boxes. For instance, in the case of projective measurements, it is possible to solve this problem with protocols using one bit of communication or making one use of a nonlocal box. We show that this problem reduces to a distributed sampling problem. We give a new method to obtain samples from a biased distribution, starting with shared random variables following a uniform distribution, and use it to build distributed sampling protocols. This approach allows us to derive, in a simpler and unified way, many existing protocols for projective measurements, and extend them to positive operator value measurements. Moreover, this approach naturally leads to a local hidden variable model for Werner states

  11. Direct and inverse problems in dispersive time-of-flight photocurrent revisited

    Science.gov (United States)

    Sagues, Francesc; Sokolov, Igor M.

    2017-10-01

    Using the fact that the continuous time random walk (CTRW) scheme is a random process subordinated to a simple random walk under the operational time given by the number of steps taken by the walker up to a given time, we revisit the problem of strongly dispersive transport in disordered media, which first lead Scher and Montroll to introducing the power law waiting time distributions. Using a subordination approach permits to disentangle the complexity of the problem, separating the solution of the boundary value problem (which is solved on the level of normal diffusive transport) from the influence of the waiting times, which allows for the solution of the direct problem in the whole time domain (including short times, out of reach of the initial approach), and simplifying strongly the analysis of the inverse problem. This analysis shows that the current traces do not contain information sufficient for unique restoration of the waiting time probability densities, but define a single-parametric family of functions that can be restored, all leading to the same photocurrent forms. The members of the family have the power-law tails which differ only by a prefactor, but may look astonishingly different at their body. The same applies to the multiple trapping model, mathematically equivalent to a special limiting case of CTRW. Contribution to the Topical Issue "Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

  12. A Random Parameter Model for Continuous-Time Mean-Variance Asset-Liability Management

    Directory of Open Access Journals (Sweden)

    Hui-qiang Ma

    2015-01-01

    Full Text Available We consider a continuous-time mean-variance asset-liability management problem in a market with random market parameters; that is, interest rate, appreciation rates, and volatility rates are considered to be stochastic processes. By using the theories of stochastic linear-quadratic (LQ optimal control and backward stochastic differential equations (BSDEs, we tackle this problem and derive optimal investment strategies as well as the mean-variance efficient frontier analytically in terms of the solution of BSDEs. We find that the efficient frontier is still a parabola in a market with random parameters. Comparing with the existing results, we also find that the liability does not affect the feasibility of the mean-variance portfolio selection problem. However, in an incomplete market with random parameters, the liability can not be fully hedged.

  13. Random walks on the braid group B3 and magnetic translations in hyperbolic geometry

    International Nuclear Information System (INIS)

    Voituriez, Raphaeel

    2002-01-01

    We study random walks on the three-strand braid group B 3 , and in particular compute the drift, or average topological complexity of a random braid, as well as the probability of trivial entanglement. These results involve the study of magnetic random walks on hyperbolic graphs (hyperbolic Harper-Hofstadter problem), what enables to build a faithful representation of B 3 as generalized magnetic translation operators for the problem of a quantum particle on the hyperbolic plane

  14. Effective Iterated Greedy Algorithm for Flow-Shop Scheduling Problems with Time lags

    Science.gov (United States)

    ZHAO, Ning; YE, Song; LI, Kaidian; CHEN, Siyu

    2017-05-01

    Flow shop scheduling problem with time lags is a practical scheduling problem and attracts many studies. Permutation problem(PFSP with time lags) is concentrated but non-permutation problem(non-PFSP with time lags) seems to be neglected. With the aim to minimize the makespan and satisfy time lag constraints, efficient algorithms corresponding to PFSP and non-PFSP problems are proposed, which consist of iterated greedy algorithm for permutation(IGTLP) and iterated greedy algorithm for non-permutation (IGTLNP). The proposed algorithms are verified using well-known simple and complex instances of permutation and non-permutation problems with various time lag ranges. The permutation results indicate that the proposed IGTLP can reach near optimal solution within nearly 11% computational time of traditional GA approach. The non-permutation results indicate that the proposed IG can reach nearly same solution within less than 1% computational time compared with traditional GA approach. The proposed research combines PFSP and non-PFSP together with minimal and maximal time lag consideration, which provides an interesting viewpoint for industrial implementation.

  15. A parallel approach to the stable marriage problem

    DEFF Research Database (Denmark)

    Larsen, Jesper

    1997-01-01

    This paper describes two parallel algorithms for the stable marriage problem implemented on a MIMD parallel computer. The algorithms are tested against sequential algorithms on randomly generated and worst-case instances. The results clearly show that the combination fo a very simple problem...... and a commercial MIMD system results in parallel algorithms which are not competitive with sequential algorithms wrt. practical performance. 1 Introduction In 1962 the Stable Marriage Problem was....

  16. Are the French neurology residents satisfied with their training?

    Science.gov (United States)

    Codron, P; Roux, T; Le Guennec, L; Zuber, M

    2015-11-01

    There have been dramatic changes in neurology over the past decade; these advances require a constant adaptation of residents' theoretical and practical training. The French Association of Neurology Residents and the College of Neurology Teachers conducted a national survey to assess the French neurology residents' satisfaction about their training. A 16-item questionnaire was sent via e-mail to French neurology residents completing training in 2014. Data were collected and processed anonymously. Of eligible respondents, 126 returned the survey, representing approximately 40% of all the French neurology residents. Most residents (78%) rated their clinical training favorably. Seventy-two percent reported good to excellent quality teaching of neurology courses from their faculty. However, many residents (40%) felt insufficient their doctoral thesis supervision. All residents intended to enter fellowship training after their residency, and most of them (68%) planned to practice in a medical center. French neurology residents seemed satisfied with the structure and quality of their training program. However, efforts are required to improve management of the doctoral thesis and make private practice more attractive and accessible during the residency. In the future, similar surveys should be scheduled to regularly assess neurology residents' satisfaction and the impact of the forthcoming national and European reforms. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  17. The Prevalence of Problem Gambling in Denmark in 2005 and 2010

    DEFF Research Database (Denmark)

    Ekholm, Ola; Eiberg, Stig; Davidsen, Michael

    2014-01-01

    Gambling is a worldwide phenomenon. For most persons this causes only small or no problems, but for some, pathological gambling can be the result of entering the gambling environment. The objectives were to estimate the past year and lifetime prevalence of problem gambling in the adult Danish...... population (16 years or older) in 2010 and trends since 2005 and, furthermore, to investigate whether problem gamblers differed from non-problem gamblers with regard to sociodemographic and socioeconomic factors. Data were derived from two national representative Danish health surveys. The survey in 2005...... was based on region-stratified random sample of 10,916 Danish citizens (response rate: 52.1 %) and the survey in 2010 was based on a random sample of 23,405 Danish citizens (response rate: 62.7 %). Problem gambling was defined using the lie/bet questionnaire. The past year prevalence of problem gamblers...

  18. Unbiased All-Optical Random-Number Generator

    Science.gov (United States)

    Steinle, Tobias; Greiner, Johannes N.; Wrachtrup, Jörg; Giessen, Harald; Gerhardt, Ilja

    2017-10-01

    The generation of random bits is of enormous importance in modern information science. Cryptographic security is based on random numbers which require a physical process for their generation. This is commonly performed by hardware random-number generators. These often exhibit a number of problems, namely experimental bias, memory in the system, and other technical subtleties, which reduce the reliability in the entropy estimation. Further, the generated outcome has to be postprocessed to "iron out" such spurious effects. Here, we present a purely optical randomness generator, based on the bistable output of an optical parametric oscillator. Detector noise plays no role and postprocessing is reduced to a minimum. Upon entering the bistable regime, initially the resulting output phase depends on vacuum fluctuations. Later, the phase is rigidly locked and can be well determined versus a pulse train, which is derived from the pump laser. This delivers an ambiguity-free output, which is reliably detected and associated with a binary outcome. The resulting random bit stream resembles a perfect coin toss and passes all relevant randomness measures. The random nature of the generated binary outcome is furthermore confirmed by an analysis of resulting conditional entropies.

  19. Effects of changing the random number stride in Monte Carlo calculations

    International Nuclear Information System (INIS)

    Hendricks, J.S.

    1991-01-01

    This paper reports on a common practice in Monte Carlo radiation transport codes which is to start each random walk a specified number of steps up the random number sequence from the previous one. This is called the stride in the random number sequence between source particles. It is used for correlated sampling or to provide tree-structured random numbers. A new random number generator algorithm for the major Monte Carlo code MCNP has been written to allow adjustment of the random number stride. This random number generator is machine portable. The effects of varying the stride for several sample problems are examined

  20. Chess games: a model for RNA based computation.

    Science.gov (United States)

    Cukras, A R; Faulhammer, D; Lipton, R J; Landweber, L F

    1999-10-01

    Here we develop the theory of RNA computing and a method for solving the 'knight problem' as an instance of a satisfiability (SAT) problem. Using only biological molecules and enzymes as tools, we developed an algorithm for solving the knight problem (3 x 3 chess board) using a 10-bit combinatorial pool and sequential RNase H digestions. The results of preliminary experiments presented here reveal that the protocol recovers far more correct solutions than expected at random, but the persistence of errors still presents the greatest challenge.

  1. Relation between random walks and quantum walks

    Science.gov (United States)

    Boettcher, Stefan; Falkner, Stefan; Portugal, Renato

    2015-05-01

    Based on studies of four specific networks, we conjecture a general relation between the walk dimensions dw of discrete-time random walks and quantum walks with the (self-inverse) Grover coin. In each case, we find that dw of the quantum walk takes on exactly half the value found for the classical random walk on the same geometry. Since walks on homogeneous lattices satisfy this relation trivially, our results for heterogeneous networks suggest that such a relation holds irrespective of whether translational invariance is maintained or not. To develop our results, we extend the renormalization-group analysis (RG) of the stochastic master equation to one with a unitary propagator. As in the classical case, the solution ρ (x ,t ) in space and time of this quantum-walk equation exhibits a scaling collapse for a variable xdw/t in the weak limit, which defines dw and illuminates fundamental aspects of the walk dynamics, e.g., its mean-square displacement. We confirm the collapse for ρ (x ,t ) in each case with extensive numerical simulation. The exact values for dw themselves demonstrate that RG is a powerful complementary approach to study the asymptotics of quantum walks that weak-limit theorems have not been able to access, such as for systems lacking translational symmetries beyond simple trees.

  2. Simulation can contribute a part of cardiorespiratory physiotherapy clinical education: two randomized trials.

    Science.gov (United States)

    Blackstock, Felicity C; Watson, Kathryn M; Morris, Norman R; Jones, Anne; Wright, Anthony; McMeeken, Joan M; Rivett, Darren A; O'Connor, Vivienne; Peterson, Raymond F; Haines, Terry P; Watson, Geoffrey; Jull, Gwendolen Anne

    2013-02-01

    Simulated learning environments (SLEs) are used worldwide in health professional education, including physiotherapy, to train certain attributes and skills. To date, no randomized controlled trial (RCT) has evaluated whether education in SLEs can partly replace time in the clinical environment for physiotherapy cardiorespiratory practice. Two independent single-blind multi-institutional RCTs were conducted in parallel using a noninferiority design. Participants were volunteer physiotherapy students (RCT 1, n = 176; RCT 2, n = 173) entering acute care cardiorespiratory physiotherapy clinical placements. Two SLE models were investigated as follows: RCT 1, 1 week in SLE before 3 weeks of clinical immersion; RCT 2, 2 weeks of interspersed SLE/clinical immersion (equivalent to 1 SLE week) within the 4-week clinical placement. Students in each RCT were stratified on academic grade and randomly allocated to an SLE plus clinical immersion or clinical immersion control group. The primary outcome was competency to practice measured in 2 clinical examinations using the Assessment of Physiotherapy Practice. Secondary outcomes were student perception of experience and clinical educator and patient rating of student performance. There were no significant differences in student competency between the SLE and control groups in either RCT, although students in the interspersed group (RCT 2) achieved a higher score in 5 of 7 Assessment of Physiotherapy Practice standards (all P Students rated the SLE experience positively. Clinical educators and patients reported comparability between groups. An SLE can replace clinical time in cardiorespiratory physiotherapy practice. Part education in the SLE satisfied clinical competency requirements, and all stakeholders were satisfied.

  3. A randomized trial of teen online problem solving for improving executive function deficits following pediatric traumatic brain injury.

    Science.gov (United States)

    Wade, Shari L; Walz, Nicolay C; Carey, JoAnne; Williams, Kendra M; Cass, Jennifer; Herren, Luke; Mark, Erin; Yeates, Keith Owen

    2010-01-01

    To examine the efficacy of teen online problem solving (TOPS) in improving executive function (EF) deficits following traumatic brain injury (TBI) in adolescence. Families of adolescents (aged 11-18 years) with moderate to severe TBI were recruited from the trauma registry of 2 tertiary-care children's hospitals and then randomly assigned to receive TOPS (n = 20), a cognitive-behavioral, skill-building intervention, or access to online resources regarding TBI (Internet resource comparison; n = 21). Parent and teen reports of EF were assessed at baseline and a posttreatment follow-up (mean = 7.88 months later). Improvements in self-reported EF skills were moderated by TBI severity, with teens with severe TBI in the TOPS treatment reporting significantly greater improvements than did those with severe TBI in the Internet resource comparison. The treatment groups did not differ on parent ratings of EF at the follow up. Findings suggest that TOPS may be effective in improving EF skills among teens with severe TBI.

  4. Effect on behavior problems of teen online problem-solving for adolescent traumatic brain injury.

    Science.gov (United States)

    Wade, Shari L; Walz, Nicolay C; Carey, Joanne; McMullen, Kendra M; Cass, Jennifer; Mark, Erin; Yeates, Keith Owen

    2011-10-01

    To report the results of a randomized clinical trial of teen online problem-solving (TOPS) meant to improve behavioral outcomes of adolescents with traumatic brain injury (TBI). A randomized clinical trial was conducted to compare the efficacy of TOPS with access to Internet resources in teenagers with TBI in improving parent and self-reported behavior problems and parent-teen conflicts. Participants included 41 adolescents aged 11 to 18 years (range: 11.47-17.90 years) who had sustained a moderate-to-severe TBI between 3 and 19 months earlier. Teens in the TOPS group received 10 to 14 online sessions that provided training in problem-solving, communication skills, and self-regulation. Outcomes were assessed before treatment and at a follow-up assessment an average of 8 months later. Groups were compared on follow-up scores after we controlled for pretreatment levels. Injury severity and socioeconomic status were examined as potential moderators of treatment efficacy. Forty-one participants provided consent and completed baseline assessments, and follow-up assessments were completed for 35 participants (16 TOPS, 19 Internet resource comparison). The TOPS group reported significantly less parent-teen conflict at follow-up than did the Internet-resource-comparison group. Improvements in teen behavior after TOPS were moderated by injury severity; there were greater improvements in the teens' internalizing symptoms after TOPS among adolescents with severe TBI. Family socioeconomic status also moderated the efficacy of TOPS in improving behavior problems reported by both parents and teens, although the nature of the moderation effects varied. Our findings suggest that TOPS contributes to improvements in parent-teen conflict generally and parent and self-reported teen behavior problems for certain subsets of participants.

  5. Piecewise linearisation of the first order loss function for families of arbitrarily distributed random variables

    NARCIS (Netherlands)

    Rossi, R.; Hendrix, E.M.T.

    2014-01-01

    We discuss the problem of computing optimal linearisation parameters for the first order loss function of a family of arbitrarily distributed random variable. We demonstrate that, in contrast to the problem in which parameters must be determined for the loss function of a single random variable,

  6. Problem solving skills for schizophrenia.

    Science.gov (United States)

    Xia, J; Li, Chunbo

    2007-04-18

    The severe and long-lasting symptoms of schizophrenia are often the cause of severe disability. Environmental stress such as life events and the practical problems people face in their daily can worsen the symptoms of schizophrenia. Deficits in problem solving skills in people with schizophrenia affect their independent and interpersonal functioning and impair their quality of life. As a result, therapies such as problem solving therapy have been developed to improve problem solving skills for people with schizophrenia. To review the effectiveness of problem solving therapy compared with other comparable therapies or routine care for those with schizophrenia. We searched the Cochrane Schizophrenia Group's Register (September 2006), which is based on regular searches of BIOSIS, CENTRAL, CINAHL, EMBASE, MEDLINE and PsycINFO. We inspected references of all identified studies for further trials. We included all clinical randomised trials comparing problem solving therapy with other comparable therapies or routine care. We extracted data independently. For homogenous dichotomous data we calculated random effects, relative risk (RR), 95% confidence intervals (CI) and, where appropriate, numbers needed to treat (NNT) on an intention-to-treat basis. For continuous data, we calculated weighted mean differences (WMD) using a random effects statistical model. We included only three small trials (n=52) that evaluated problem solving versus routine care, coping skills training or non-specific interaction. Inadequate reporting of data rendered many outcomes unusable. We were unable to undertake meta-analysis. Overall results were limited and inconclusive with no significant differences between treatment groups for hospital admission, mental state, behaviour, social skills or leaving the study early. No data were presented for global state, quality of life or satisfaction. We found insufficient evidence to confirm or refute the benefits of problem solving therapy as an additional

  7. A Survey on Psychosocial Problems in Adolescents with

    Directory of Open Access Journals (Sweden)

    Asghar Dalvandi

    2001-06-01

    Full Text Available Objective: The impact of alcohol and other drugs increase dramatically in adolescent's lives when their parents are dependent drug users. Not only the children are at risk of developing drug users, but also they are at risk of developing drug related problems later in their life. They may also suffer other social and psychological problems. Matetials & Methods: The present study focusing on psychosocial problems of adolescents with addicted father, Uses the (s.c.l-90 and educational conditions Questionnaires.  It is a "Case-control" study. Our samples include 40 adolescents with "addicted father" and 80 with "non-addicted father". The addicted fathers were chosen randomly from Gharchak rehabilitation center. The adolescents ages were between 12-18 years old chosen randomly and matched by variables such as sex, age, education. Results: The result of the study shows a significant differences between the psychosocial problems of adolescents with "addicted father" and "non-addicted" ones, (p<0.05. So such that in our case group we see a higher drop in school subject anxiety and interactional disorders. Conclusion: It seems that there is a correlation between the addiction of father and psychosocial problems of their children.

  8. Explicit solutions to correlation matrix completion problems, with an application to risk management and insurance.

    Science.gov (United States)

    Georgescu, Dan I; Higham, Nicholas J; Peters, Gareth W

    2018-03-01

    We derive explicit solutions to the problem of completing a partially specified correlation matrix. Our results apply to several block structures for the unspecified entries that arise in insurance and risk management, where an insurance company with many lines of business is required to satisfy certain capital requirements but may have incomplete knowledge of the underlying correlation matrix. Among the many possible completions, we focus on the one with maximal determinant. This has attractive properties and we argue that it is suitable for use in the insurance application. Our explicit formulae enable easy solution of practical problems and are useful for testing more general algorithms for the maximal determinant correlation matrix completion problem.

  9. Does Problem-Solving Training for Family Caregivers Benefit Their Care Recipients With Severe Disabilities? A Latent Growth Model of the Project CLUES Randomized Clinical Trial

    Science.gov (United States)

    Berry, Jack W.; Elliott, Timothy R.; Grant, Joan S.; Edwards, Gary; Fine, Philip R.

    2012-01-01

    Objective To examine whether an individualized problem-solving intervention provided to family caregivers of persons with severe disabilities provides benefits to both caregivers and their care recipients. Design Family caregivers were randomly assigned to an education-only control group or a problem-solving training (PST) intervention group. Participants received monthly contacts for 1 year. Participants Family caregivers (129 women, 18 men) and their care recipients (81 women, 66 men) consented to participate. Main Outcome Measures Caregivers completed the Social Problem-Solving Inventory–Revised, the Center for Epidemiological Studies-Depression scale, the Satisfaction with Life scale, and a measure of health complaints at baseline and in 3 additional assessments throughout the year. Care recipient depression was assessed with a short form of the Hamilton Depression Scale. Results Latent growth modeling was used to analyze data from the dyads. Caregivers who received PST reported a significant decrease in depression over time, and they also displayed gains in constructive problem-solving abilities and decreases in dysfunctional problem-solving abilities. Care recipients displayed significant decreases in depression over time, and these decreases were significantly associated with decreases in caregiver depression in response to training. Conclusions PST significantly improved the problem-solving skills of community-residing caregivers and also lessened their depressive symptoms. Care recipients in the PST group also had reductions in depression over time, and it appears that decreases in caregiver depression may account for this effect. PMID:22686549

  10. Multi-agent coordination in directed moving neighbourhood random networks

    International Nuclear Information System (INIS)

    Yi-Lun, Shang

    2010-01-01

    This paper considers the consensus problem of dynamical multiple agents that communicate via a directed moving neighbourhood random network. Each agent performs random walk on a weighted directed network. Agents interact with each other through random unidirectional information flow when they coincide in the underlying network at a given instant. For such a framework, we present sufficient conditions for almost sure asymptotic consensus. Numerical examples are taken to show the effectiveness of the obtained results. (general)

  11. Detecting effects of the indicated prevention Programme for Externalizing Problem behaviour (PEP) on child symptoms, parenting, and parental quality of life in a randomized controlled trial.

    Science.gov (United States)

    Hanisch, Charlotte; Freund-Braier, Inez; Hautmann, Christopher; Jänen, Nicola; Plück, Julia; Brix, Gabriele; Eichelberger, Ilka; Döpfner, Manfred

    2010-01-01

    Behavioural parent training is effective in improving child disruptive behavioural problems in preschool children by increasing parenting competence. The indicated Prevention Programme for Externalizing Problem behaviour (PEP) is a group training programme for parents and kindergarten teachers of children aged 3-6 years with externalizing behavioural problems. To evaluate the effects of PEP on child problem behaviour, parenting practices, parent-child interactions, and parental quality of life. Parents and kindergarten teachers of 155 children were randomly assigned to an intervention group (n = 91) and a nontreated control group (n = 64). They rated children's problem behaviour before and after PEP training; parents also reported on their parenting practices and quality of life. Standardized play situations were video-taped and rated for parent-child interactions, e.g. parental warmth. In the intention to treat analysis, mothers of the intervention group described less disruptive child behaviour and better parenting strategies, and showed more parental warmth during a standardized parent-child interaction. Dosage analyses confirmed these results for parents who attended at least five training sessions. Children were also rated to show less behaviour problems by their kindergarten teachers. Training effects were especially positive for parents who attended at least half of the training sessions. CBCL: Child Behaviour Checklist; CII: Coder Impressions Inventory; DASS: Depression anxiety Stress Scale; HSQ: Home-situation Questionnaire; LSS: Life Satisfaction Scale; OBDT: observed behaviour during the test; PCL: Problem Checklist; PEP: prevention programme for externalizing problem behaviour; PPC: Parent Problem Checklist; PPS: Parent Practices Scale; PS: Parenting Scale; PSBC: Problem Setting and Behaviour checklist; QJPS: Questionnaire on Judging Parental Strains; SEFS: Self-Efficacy Scale; SSC: Social Support Scale; TRF: Caregiver-Teacher Report Form.

  12. Rational decisions, random matrices and spin glasses

    Science.gov (United States)

    Galluccio, Stefano; Bouchaud, Jean-Philippe; Potters, Marc

    We consider the problem of rational decision making in the presence of nonlinear constraints. By using tools borrowed from spin glass and random matrix theory, we focus on the portfolio optimisation problem. We show that the number of optimal solutions is generally exponentially large, and each of them is fragile: rationality is in this case of limited use. In addition, this problem is related to spin glasses with Lévy-like (long-ranged) couplings, for which we show that the ground state is not exponentially degenerate.

  13. Golden Ratio Versus Pi as Random Sequence Sources for Monte Carlo Integration

    Science.gov (United States)

    Sen, S. K.; Agarwal, Ravi P.; Shaykhian, Gholam Ali

    2007-01-01

    We discuss here the relative merits of these numbers as possible random sequence sources. The quality of these sequences is not judged directly based on the outcome of all known tests for the randomness of a sequence. Instead, it is determined implicitly by the accuracy of the Monte Carlo integration in a statistical sense. Since our main motive of using a random sequence is to solve real world problems, it is more desirable if we compare the quality of the sequences based on their performances for these problems in terms of quality/accuracy of the output. We also compare these sources against those generated by a popular pseudo-random generator, viz., the Matlab rand and the quasi-random generator ha/ton both in terms of error and time complexity. Our study demonstrates that consecutive blocks of digits of each of these numbers produce a good random sequence source. It is observed that randomly chosen blocks of digits do not have any remarkable advantage over consecutive blocks for the accuracy of the Monte Carlo integration. Also, it reveals that pi is a better source of a random sequence than theta when the accuracy of the integration is concerned.

  14. Optimal Water-Power Flow Problem: Formulation and Distributed Optimal Solution

    Energy Technology Data Exchange (ETDEWEB)

    Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhao, Changhong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zamzam, Admed S. [University of Minnesota; Sidiropoulos, Nicholas D. [University of Minnesota; Taylor, Josh A. [University of Toronto

    2018-01-12

    This paper formalizes an optimal water-power flow (OWPF) problem to optimize the use of controllable assets across power and water systems while accounting for the couplings between the two infrastructures. Tanks and pumps are optimally managed to satisfy water demand while improving power grid operations; {for the power network, an AC optimal power flow formulation is augmented to accommodate the controllability of water pumps.} Unfortunately, the physics governing the operation of the two infrastructures and coupling constraints lead to a nonconvex (and, in fact, NP-hard) problem; however, after reformulating OWPF as a nonconvex, quadratically-constrained quadratic problem, a feasible point pursuit-successive convex approximation approach is used to identify feasible and optimal solutions. In addition, a distributed solver based on the alternating direction method of multipliers enables water and power operators to pursue individual objectives while respecting the couplings between the two networks. The merits of the proposed approach are demonstrated for the case of a distribution feeder coupled with a municipal water distribution network.

  15. Life skills, mathematical reasoning and critical thinking: a curriculum for the prevention of problem gambling.

    Science.gov (United States)

    Turner, Nigel E; Macdonald, John; Somerset, Matthew

    2008-09-01

    Previous studies have shown that youth are two to three times more likely than adults to report gambling related problems. This paper reports on the development and pilot evaluation of a school-based problem gambling prevention curriculum. The prevention program focused on problem gambling awareness and self-monitoring skills, coping skills, and knowledge of the nature of random events. The results of a controlled experiment evaluating the students learning from the program are reported. We found significant improvement in the students' knowledge of random events, knowledge of problem gambling awareness and self-monitoring, and knowledge of coping skills. The results suggest that knowledge based material on random events, problem gambling awareness and self-monitoring skills, and coping skills can be taught. Future development of the curriculum will focus on content to expand the students' coping skill options.

  16. Doing the Impossible: A Note on Induction and the Experience of Randomness.

    Science.gov (United States)

    Lopes, Lola L.

    1982-01-01

    The process of induction is formulated as a problem in detecting nonrandomness, or pattern, against a background of randomness, or noise. Experimental and philosophical approaches to human conceptions of randomness are contrasted. The relation between induction and the experience of randomness is discussed in terms of signal-detection theory.…

  17. Large neighborhood search for the double traveling salesman problem with multiple stacks

    Energy Technology Data Exchange (ETDEWEB)

    Bent, Russell W [Los Alamos National Laboratory; Van Hentenryck, Pascal [BROWN UNIV

    2009-01-01

    This paper considers a complex real-life short-haul/long haul pickup and delivery application. The problem can be modeled as double traveling salesman problem (TSP) in which the pickups and the deliveries happen in the first and second TSPs respectively. Moreover, the application features multiple stacks in which the items must be stored and the pickups and deliveries must take place in reserve (LIFO) order for each stack. The goal is to minimize the total travel time satisfying these constraints. This paper presents a large neighborhood search (LNS) algorithm which improves the best-known results on 65% of the available instances and is always within 2% of the best-known solutions.

  18. Fermi problem in disordered systems

    Science.gov (United States)

    Menezes, G.; Svaiter, N. F.; de Mello, H. R.; Zarro, C. A. D.

    2017-10-01

    We revisit the Fermi two-atom problem in the framework of disordered systems. In our model, we consider a two-qubit system linearly coupled with a quantum massless scalar field. We analyze the energy transfer between the qubits under different experimental perspectives. In addition, we assume that the coefficients of the Klein-Gordon equation are random functions of the spatial coordinates. The disordered medium is modeled by a centered, stationary, and Gaussian process. We demonstrate that the classical notion of causality emerges only in the wave zone in the presence of random fluctuations of the light cone. Possible repercussions are discussed.

  19. Average-case analysis of numerical problems

    CERN Document Server

    2000-01-01

    The average-case analysis of numerical problems is the counterpart of the more traditional worst-case approach. The analysis of average error and cost leads to new insight on numerical problems as well as to new algorithms. The book provides a survey of results that were mainly obtained during the last 10 years and also contains new results. The problems under consideration include approximation/optimal recovery and numerical integration of univariate and multivariate functions as well as zero-finding and global optimization. Background material, e.g. on reproducing kernel Hilbert spaces and random fields, is provided.

  20. A Novel Algorithm of Quantum Random Walk in Server Traffic Control and Task Scheduling

    Directory of Open Access Journals (Sweden)

    Dong Yumin

    2014-01-01

    Full Text Available A quantum random walk optimization model and algorithm in network cluster server traffic control and task scheduling is proposed. In order to solve the problem of server load balancing, we research and discuss the distribution theory of energy field in quantum mechanics and apply it to data clustering. We introduce the method of random walk and illuminate what the quantum random walk is. Here, we mainly research the standard model of one-dimensional quantum random walk. For the data clustering problem of high dimensional space, we can decompose one m-dimensional quantum random walk into m one-dimensional quantum random walk. In the end of the paper, we compare the quantum random walk optimization method with GA (genetic algorithm, ACO (ant colony optimization, and SAA (simulated annealing algorithm. In the same time, we prove its validity and rationality by the experiment of analog and simulation.