NASA Technical Reports Server (NTRS)
Sohn, Andrew; Biswas, Rupak
1996-01-01
Solving the hard Satisfiability Problem is time consuming even for modest-sized problem instances. Solving the Random L-SAT Problem is especially difficult due to the ratio of clauses to variables. This report presents a parallel synchronous simulated annealing method for solving the Random L-SAT Problem on a large-scale distributed-memory multiprocessor. In particular, we use a parallel synchronous simulated annealing procedure, called Generalized Speculative Computation, which guarantees the same decision sequence as sequential simulated annealing. To demonstrate the performance of the parallel method, we have selected problem instances varying in size from 100-variables/425-clauses to 5000-variables/21,250-clauses. Experimental results on the AP1000 multiprocessor indicate that our approach can satisfy 99.9 percent of the clauses while giving almost a 70-fold speedup on 500 processors.
Competitive Facility Location with Random Demands
NASA Astrophysics Data System (ADS)
Uno, Takeshi; Katagiri, Hideki; Kato, Kosuke
2009-10-01
This paper proposes a new location problem of competitive facilities, e.g. shops and stores, with uncertain demands in the plane. By representing the demands for facilities as random variables, the location problem is formulated to a stochastic programming problem, and for finding its solution, three deterministic programming problems: expectation maximizing problem, probability maximizing problem, and satisfying level maximizing problem are considered. After showing that one of their optimal solutions can be found by solving 0-1 programming problems, their solution method is proposed by improving the tabu search algorithm with strategic vibration. Efficiency of the solution method is shown by applying to numerical examples of the facility location problems.
Quiet planting in the locked constraints satisfaction problems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zdeborova, Lenka; Krzakala, Florent
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.
NASA Astrophysics Data System (ADS)
Mandrà, Salvatore; Giacomo Guerreschi, Gian; Aspuru-Guzik, Alán
2016-07-01
We present an exact quantum algorithm for solving the Exact Satisfiability problem, which belongs to the important NP-complete complexity class. The algorithm is based on an intuitive approach that can be divided into two parts: the first step consists in the identification and efficient characterization of a restricted subspace that contains all the valid assignments of the Exact Satisfiability; while the second part performs a quantum search in such restricted subspace. The quantum algorithm can be used either to find a valid assignment (or to certify that no solution exists) or to count the total number of valid assignments. The query complexities for the worst-case are respectively bounded by O(\\sqrt{{2}n-{M\\prime }}) and O({2}n-{M\\prime }), where n is the number of variables and {M}\\prime the number of linearly independent clauses. Remarkably, the proposed quantum algorithm results to be faster than any known exact classical algorithm to solve dense formulas of Exact Satisfiability. As a concrete application, we provide the worst-case complexity for the Hamiltonian cycle problem obtained after mapping it to a suitable Occupation problem. Specifically, we show that the time complexity for the proposed quantum algorithm is bounded by O({2}n/4) for 3-regular undirected graphs, where n is the number of nodes. The same worst-case complexity holds for (3,3)-regular bipartite graphs. As a reference, the current best classical algorithm has a (worst-case) running time bounded by O({2}31n/96). Finally, when compared to heuristic techniques for Exact Satisfiability problems, the proposed quantum algorithm is faster than the classical WalkSAT and Adiabatic Quantum Optimization for random instances with a density of constraints close to the satisfiability threshold, the regime in which instances are typically the hardest to solve. The proposed quantum algorithm can be straightforwardly extended to the generalized version of the Exact Satisfiability known as Occupation problem. The general version of the algorithm is presented and analyzed.
Chess games: a model for RNA based computation.
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.
Han, Win T; Collie, Kate; Koopman, Cheryl; Azarow, Jay; Classen, Catherine; Morrow, Gary R; Michel, Betsy; Brennan-O'Neill, Eileen; Spiegel, David
2005-04-01
This investigation examined relationships between breast cancer patients' psychosocial characteristics (impact of the illness, traumatic stress symptoms, emotional self-efficacy, and social support) and problems they perceived in their medical interactions and their satisfaction with their physicians. Participants were 352 women enrolled in a multicenter trial of the effects of group therapy for women with recently diagnosed primary breast cancer. The findings reported here are from a cross-sectional analysis of baseline data gathered prior to randomization. Problems interacting with physicians and nurses were associated with greater levels of cancer-related traumatic stress (p < 0.01), less emotional self-efficacy for cancer (p < 0.05), less satisfaction with informational support from family, friends, and spouse, and a tendency to perceive those sources of support as more aversive (p < 0.05). Women who were less satisfied with emotional support from their family, friends and spouse were less likely to feel satisfied with their physicians (p < 0.05). These patient characteristics identify women with primary breast cancer who are likely to experience difficulty in their interactions with nurses and physicians and to be less satisfied with their physicians.
Raney Distributions and Random Matrix Theory
NASA Astrophysics Data System (ADS)
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.
Amoeba-Inspired Heuristic Search Dynamics for Exploring Chemical Reaction Paths.
Aono, Masashi; Wakabayashi, Masamitsu
2015-09-01
We propose a nature-inspired model for simulating chemical reactions in a computationally resource-saving manner. The model was developed by extending our previously proposed heuristic search algorithm, called "AmoebaSAT [Aono et al. 2013]," which was inspired by the spatiotemporal dynamics of a single-celled amoeboid organism that exhibits sophisticated computing capabilities in adapting to its environment efficiently [Zhu et al. 2013]. AmoebaSAT is used for solving an NP-complete combinatorial optimization problem [Garey and Johnson 1979], "the satisfiability problem," and finds a constraint-satisfying solution at a speed that is dramatically faster than one of the conventionally known fastest stochastic local search methods [Iwama and Tamaki 2004] for a class of randomly generated problem instances [ http://www.cs.ubc.ca/~hoos/5/benchm.html ]. In cases where the problem has more than one solution, AmoebaSAT exhibits dynamic transition behavior among a variety of the solutions. Inheriting these features of AmoebaSAT, we formulate "AmoebaChem," which explores a variety of metastable molecules in which several constraints determined by input atoms are satisfied and generates dynamic transition processes among the metastable molecules. AmoebaChem and its developed forms will be applied to the study of the origins of life, to discover reaction paths for which expected or unexpected organic compounds may be formed via unknown unstable intermediates and to estimate the likelihood of each of the discovered paths.
Li, Ning; Cao, Chao; Wang, Cong
2017-06-15
Supporting simultaneous access of machine-type devices is a critical challenge in machine-to-machine (M2M) communications. In this paper, we propose an optimal scheme to dynamically adjust the Access Class Barring (ACB) factor and the number of random access channel (RACH) resources for clustered machine-to-machine (M2M) communications, in which Delay-Sensitive (DS) devices coexist with Delay-Tolerant (DT) ones. In M2M communications, since delay-sensitive devices share random access resources with delay-tolerant devices, reducing the resources consumed by delay-sensitive devices means that there will be more resources available to delay-tolerant ones. Our goal is to optimize the random access scheme, which can not only satisfy the requirements of delay-sensitive devices, but also take the communication quality of delay-tolerant ones into consideration. We discuss this problem from the perspective of delay-sensitive services by adjusting the resource allocation and ACB scheme for these devices dynamically. Simulation results show that our proposed scheme realizes good performance in satisfying the delay-sensitive services as well as increasing the utilization rate of the random access resources allocated to them.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baker, Kyri; Toomey, Bridget
Evolving power systems with increasing levels of stochasticity call for a need to solve optimal power flow problems with large quantities of random variables. Weather forecasts, electricity prices, and shifting load patterns introduce higher levels of uncertainty and can yield optimization problems that are difficult to solve in an efficient manner. Solution methods for single chance constraints in optimal power flow problems have been considered in the literature, ensuring single constraints are satisfied with a prescribed probability; however, joint chance constraints, ensuring multiple constraints are simultaneously satisfied, have predominantly been solved via scenario-based approaches or by utilizing Boole's inequality asmore » an upper bound. In this paper, joint chance constraints are used to solve an AC optimal power flow problem while preventing overvoltages in distribution grids under high penetrations of photovoltaic systems. A tighter version of Boole's inequality is derived and used to provide a new upper bound on the joint chance constraint, and simulation results are shown demonstrating the benefit of the proposed upper bound. The new framework allows for a less conservative and more computationally efficient solution to considering joint chance constraints, specifically regarding preventing overvoltages.« less
Quantum Adiabatic Optimization and Combinatorial Landscapes
NASA Technical Reports Server (NTRS)
Smelyanskiy, V. N.; Knysh, S.; Morris, R. D.
2003-01-01
In this paper we analyze the performance of the Quantum Adiabatic Evolution (QAE) algorithm on a variant of Satisfiability problem for an ensemble of random graphs parametrized by the ratio of clauses to variables, gamma = M / N. We introduce a set of macroscopic parameters (landscapes) and put forward an ansatz of universality for random bit flips. We then formulate the problem of finding the smallest eigenvalue and the excitation gap as a statistical mechanics problem. We use the so-called annealing approximation with a refinement that a finite set of macroscopic variables (verses only energy) is used, and are able to show the existence of a dynamic threshold gamma = gammad, beyond which QAE should take an exponentially long time to find a solution. We compare the results for extended and simplified sets of landscapes and provide numerical evidence in support of our universality ansatz.
Generalization of one-dimensional solute transport: A stochastic-convective flow conceptualization
NASA Astrophysics Data System (ADS)
Simmons, C. S.
1986-04-01
A stochastic-convective representation of one-dimensional solute transport is derived. It is shown to conceptually encompass solutions of the conventional convection-dispersion equation. This stochastic approach, however, does not rely on the assumption that dispersive flux satisfies Fick's diffusion law. Observable values of solute concentration and flux, which together satisfy a conservation equation, are expressed as expectations over a flow velocity ensemble, representing the inherent random processess that govern dispersion. Solute concentration is determined by a Lagrangian pdf for random spatial displacements, while flux is determined by an equivalent Eulerian pdf for random travel times. A condition for such equivalence is derived for steady nonuniform flow, and it is proven that both Lagrangian and Eulerian pdfs are required to account for specified initial and boundary conditions on a global scale. Furthermore, simplified modeling of transport is justified by proving that an ensemble of effectively constant velocities always exists that constitutes an equivalent representation. An example of how a two-dimensional transport problem can be reduced to a single-dimensional stochastic viewpoint is also presented to further clarify concepts.
NASA Astrophysics Data System (ADS)
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.
Thermodynamic limit of random partitions and dispersionless Toda hierarchy
NASA Astrophysics Data System (ADS)
Takasaki, Kanehisa; Nakatsu, Toshio
2012-01-01
We study the thermodynamic limit of random partition models for the instanton sum of 4D and 5D supersymmetric U(1) gauge theories deformed by some physical observables. The physical observables correspond to external potentials in the statistical model. The partition function is reformulated in terms of the density function of Maya diagrams. The thermodynamic limit is governed by a limit shape of Young diagrams associated with dominant terms in the partition function. The limit shape is characterized by a variational problem, which is further converted to a scalar-valued Riemann-Hilbert problem. This Riemann-Hilbert problem is solved with the aid of a complex curve, which may be thought of as the Seiberg-Witten curve of the deformed U(1) gauge theory. This solution of the Riemann-Hilbert problem is identified with a special solution of the dispersionless Toda hierarchy that satisfies a pair of generalized string equations. The generalized string equations for the 5D gauge theory are shown to be related to hidden symmetries of the statistical model. The prepotential and the Seiberg-Witten differential are also considered.
Stock management in hospital pharmacy using chance-constrained model predictive control.
Jurado, I; Maestre, J M; Velarde, P; Ocampo-Martinez, C; Fernández, I; Tejera, B Isla; Prado, J R Del
2016-05-01
One of the most important problems in the pharmacy department of a hospital is stock management. The clinical need for drugs must be satisfied with limited work labor while minimizing the use of economic resources. The complexity of the problem resides in the random nature of the drug demand and the multiple constraints that must be taken into account in every decision. In this article, chance-constrained model predictive control is proposed to deal with this problem. The flexibility of model predictive control allows taking into account explicitly the different objectives and constraints involved in the problem while the use of chance constraints provides a trade-off between conservativeness and efficiency. The solution proposed is assessed to study its implementation in two Spanish hospitals. Copyright © 2015 Elsevier Ltd. All rights reserved.
Unified heuristics to solve routing problem of reverse logistics in sustainable supply chain
NASA Astrophysics Data System (ADS)
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.
2012-01-17
PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION...world problems. Our work brings together techniques from constraint programming, mathematical programming, and satisfiability in a symbiotic way to...power-‐law search tree model for complete or exact methods (See [9] for a detailed description of this work and
DOE Office of Scientific and Technical Information (OSTI.GOV)
Diaz-Cruz, J. L.
We discuss several aspects of the flavor problem in the Supersymmetry. First, in order to quantify the SUSY flavor problem, we generate randomly the entries of the sfermion mass matrices and determine which percentage of the points are consistent with current bounds on the flavor violating transitions, for which we take as an illustration the lepton flavor violating (LFV) decays li {yields} lj{gamma}. In the first instance we apply the mass-insertion method, and study how this percentage changes as one varies the parameters of the model. It is found that for 105 points about 10% of points pass current LFVmore » bounds on {mu} {yields} e{gamma} provided the sleptons masses are {approx} 10 TeV. While bounds on {tau} {yields} {mu}{gamma}, e{gamma} are satisfied for almost 100% of points even for sleptons masses as low as 360 GeV. Then, we consider an ansatz for sfermion masses that can be diagonalized exactly, and compare the results obtained previously for {tau} {yields} {mu}{gamma}. Now, we get that 100% of points satisfy the experimental bounds but with sleptons masses larger than 460 GeV.« less
Jalava, M; Sillanpää, M; Camfield, C; Camfield, P
1997-06-01
To study the effect of childhood-onset epilepsy without other neurologic deficit on adult social adjustment and competence. Social competence was studied in a prospective, population-based cohort of childhood-onset epilepsy after a mean follow-up of 35 years. One hundred patients (60% of the total cohort) had no other neurologic problems ("epilepsy only"), and for each patient, two matched controls, a "random" control and an "employee" control were chosen. Good social outcome was significantly reduced in the "epilepsy only" cohort compared with random controls: education [cumulative odds ratio (COR), 2.4; 95% confidence interval (CI), 1.4-4.1]; employability (COR, 7.3; 95% CI, 2.7-20.0); and marriage rate (COR, 3.7; 95% CI, 1.9-7.3). The patients with epilepsy rated their own ability to control their lives as "poor or missing" four times more frequently than the employee controls. Patients receiving antiepileptic polytherapy, but not monotherapy, were significantly less satisfied with their present life (OR, 6.7; 95% CI, 1.9-24.1) and felt their general health was significantly poorer (OR, 5.1; 95% CI, 1.2-21.3) than did the employee controls. Furthermore, patients with continuing seizures were significantly less satisfied with their present life (OR, 4.1; 95% CI, 1.1-15.1) than were employee controls. Many patients with "epilepsy only" beginning in childhood have persistent and significant social-adjustment and competence problems in adulthood.
Random Predictor Models for Rigorous Uncertainty Quantification: Part 2
NASA Technical Reports Server (NTRS)
Crespo, Luis G.; Kenny, Sean P.; Giesy, Daniel P.
2015-01-01
This and a companion paper propose techniques for constructing parametric mathematical models describing key features of the distribution of an output variable given input-output data. By contrast to standard models, which yield a single output value at each value of the input, Random Predictors Models (RPMs) yield a random variable at each value of the input. Optimization-based strategies for calculating RPMs having a polynomial dependency on the input and a linear dependency on the parameters are proposed. These formulations yield RPMs having various levels of fidelity in which the mean, the variance, and the range of the model's parameter, thus of the output, are prescribed. As such they encompass all RPMs conforming to these prescriptions. The RPMs are optimal in the sense that they yield the tightest predictions for which all (or, depending on the formulation, most) of the observations are less than a fixed number of standard deviations from the mean prediction. When the data satisfies mild stochastic assumptions, and the optimization problem(s) used to calculate the RPM is convex (or, when its solution coincides with the solution to an auxiliary convex problem), the model's reliability, which is the probability that a future observation would be within the predicted ranges, is bounded rigorously.
Random Predictor Models for Rigorous Uncertainty Quantification: Part 1
NASA Technical Reports Server (NTRS)
Crespo, Luis G.; Kenny, Sean P.; Giesy, Daniel P.
2015-01-01
This and a companion paper propose techniques for constructing parametric mathematical models describing key features of the distribution of an output variable given input-output data. By contrast to standard models, which yield a single output value at each value of the input, Random Predictors Models (RPMs) yield a random variable at each value of the input. Optimization-based strategies for calculating RPMs having a polynomial dependency on the input and a linear dependency on the parameters are proposed. These formulations yield RPMs having various levels of fidelity in which the mean and the variance of the model's parameters, thus of the predicted output, are prescribed. As such they encompass all RPMs conforming to these prescriptions. The RPMs are optimal in the sense that they yield the tightest predictions for which all (or, depending on the formulation, most) of the observations are less than a fixed number of standard deviations from the mean prediction. When the data satisfies mild stochastic assumptions, and the optimization problem(s) used to calculate the RPM is convex (or, when its solution coincides with the solution to an auxiliary convex problem), the model's reliability, which is the probability that a future observation would be within the predicted ranges, can be bounded tightly and rigorously.
The Approximability of Learning and Constraint Satisfaction Problems
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
Random isotropic one-dimensional XY-model
NASA Astrophysics Data System (ADS)
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) .
Eroglu, Duygu Yilmaz; Ozmutlu, H Cenk
2014-01-01
We developed mixed integer programming (MIP) models and hybrid genetic-local search algorithms for the scheduling problem of unrelated parallel machines with job sequence and machine-dependent setup times and with job splitting property. The first contribution of this paper is to introduce novel algorithms which make splitting and scheduling simultaneously with variable number of subjobs. We proposed simple chromosome structure which is constituted by random key numbers in hybrid genetic-local search algorithm (GAspLA). Random key numbers are used frequently in genetic algorithms, but it creates additional difficulty when hybrid factors in local search are implemented. We developed algorithms that satisfy the adaptation of results of local search into the genetic algorithms with minimum relocation operation of genes' random key numbers. This is the second contribution of the paper. The third contribution of this paper is three developed new MIP models which are making splitting and scheduling simultaneously. The fourth contribution of this paper is implementation of the GAspLAMIP. This implementation let us verify the optimality of GAspLA for the studied combinations. The proposed methods are tested on a set of problems taken from the literature and the results validate the effectiveness of the proposed algorithms.
NASA Astrophysics Data System (ADS)
Musharbash, Eleonora; Nobile, Fabio
2018-02-01
In this paper we propose a method for the strong imposition of random Dirichlet boundary conditions in the Dynamical Low Rank (DLR) approximation of parabolic PDEs and, in particular, incompressible Navier Stokes equations. We show that the DLR variational principle can be set in the constrained manifold of all S rank random fields with a prescribed value on the boundary, expressed in low rank format, with rank smaller then S. We characterize the tangent space to the constrained manifold by means of a Dual Dynamically Orthogonal (Dual DO) formulation, in which the stochastic modes are kept orthonormal and the deterministic modes satisfy suitable boundary conditions, consistent with the original problem. The Dual DO formulation is also convenient to include the incompressibility constraint, when dealing with incompressible Navier Stokes equations. We show the performance of the proposed Dual DO approximation on two numerical test cases: the classical benchmark of a laminar flow around a cylinder with random inflow velocity, and a biomedical application for simulating blood flow in realistic carotid artery reconstructed from MRI data with random inflow conditions coming from Doppler measurements.
Combination of azelaic acid 5% and clindamycin 2% for the treatment of acne vulgaris.
Pazoki-Toroudi, Hamidreza; Nilforoushzadeh, Mohamad Ali; Ajami, Marjan; Jaffary, Fariba; Aboutaleb, Nahid; Nassiri-Kashani, Mansour; Firooz, Alireza
2011-12-01
Acne vulgaris, an inflammatory skin disease with different clinical appearances, is a common problem in most adolescents. It seems that using combinations of topical agents can decrease resistance to the treatment and improve the efficacy. Therefore, we evaluated the effects of azelaic acid (AA) 5% and clindamycin (Clin) 2% combination (AA-Clin) on mild-to-moderate acne vulgaris. The efficacy and safety of 12-week treatment with AA-Clin in patients with mild-to-moderate facial acne vulgaris were evaluated by a multicenter, randomized, and double-blind study. A total of 88 male and 62 female patients were randomly assigned to one of these treatments: AA 5%, Clin 2%, and combination of them. Every 4 weeks, total inflammatory and noninflammatory lesions were counted, acne severity index (ASI) was calculated, and patient satisfaction was recorded. Treatment for 12 weeks with combination gel significantly reduced the total lesion number compared with baseline (p < 0.01), as well as Clin 2% or AA 5% treatment groups (p < 0.05 or p < 0.01). The percentage of reduction in ASI in combination treated group (64.16 ± 6.01) was significantly more than those in the Clin 2% (47.73 ± 6.62, p < 0.05) and 5% AA (32.46 ± 5.27, p < 0.01) groups after 12 weeks. Among the patients in the AA-Clin group, 75.86% of males were satisfied or very satisfied and 85.71% of females were satisfied or very satisfied. This trend was significant in comparison to the number of patients who were satisfied with AA 5% or Clin 2% treatment (p < 0.01). Seven patients in AA-Clin group (incidence = 22%) showed adverse effects that were not statistically significant compared to treatment with individual active ingredients. The profound reduction in lesion count and ASI by combination therapy with AA-Clin gel in comparison to individual treatment with 5% AA or Clin 2% suggested the combination formula as an effective alternative in treatment of acne vulgaris.
When Gravity Fails: Local Search Topology
NASA Technical Reports Server (NTRS)
Frank, Jeremy; Cheeseman, Peter; Stutz, John; Lau, Sonie (Technical Monitor)
1997-01-01
Local search algorithms for combinatorial search problems frequently encounter a sequence of states in which it is impossible to improve the value of the objective function; moves through these regions, called {\\em plateau moves), dominate the time spent in local search. We analyze and characterize {\\em plateaus) for three different classes of randomly generated Boolean Satisfiability problems. We identify several interesting features of plateaus that impact the performance of local search algorithms. We show that local minima tend to be small but occasionally may be very large. We also show that local minima can be escaped without unsatisfying a large number of clauses, but that systematically searching for an escape route may be computationally expensive if the local minimum is large. We show that plateaus with exits, called benches, tend to be much larger than minima, and that some benches have very few exit states which local search can use to escape. We show that the solutions (i.e. global minima) of randomly generated problem instances form clusters, which behave similarly to local minima. We revisit several enhancements of local search algorithms and explain their performance in light of our results. Finally we discuss strategies for creating the next generation of local search algorithms.
Coverage Metrics for Requirements-Based Testing: Evaluation of Effectiveness
NASA Technical Reports Server (NTRS)
Staats, Matt; Whalen, Michael W.; Heindahl, Mats P. E.; Rajan, Ajitha
2010-01-01
In black-box testing, the tester creates a set of tests to exercise a system under test without regard to the internal structure of the system. Generally, no objective metric is used to measure the adequacy of black-box tests. In recent work, we have proposed three requirements coverage metrics, allowing testers to objectively measure the adequacy of a black-box test suite with respect to a set of requirements formalized as Linear Temporal Logic (LTL) properties. In this report, we evaluate the effectiveness of these coverage metrics with respect to fault finding. Specifically, we conduct an empirical study to investigate two questions: (1) do test suites satisfying a requirements coverage metric provide better fault finding than randomly generated test suites of approximately the same size?, and (2) do test suites satisfying a more rigorous requirements coverage metric provide better fault finding than test suites satisfying a less rigorous requirements coverage metric? Our results indicate (1) only one coverage metric proposed -- Unique First Cause (UFC) coverage -- is sufficiently rigorous to ensure test suites satisfying the metric outperform randomly generated test suites of similar size and (2) that test suites satisfying more rigorous coverage metrics provide better fault finding than test suites satisfying less rigorous coverage metrics.
Poot, Antonius J.; den Elzen, Wendy P. J.; Blom, Jeanet W.; Gussekloo, Jacobijn
2014-01-01
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 investigate the causal associations between care organization, patient characteristics, indicators of quality, and patient perceptions. PMID:24710557
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 (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). 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 investigate the causal associations between care organization, patient characteristics, indicators of quality, and patient perceptions.
Solving SAT Problem Based on Hybrid Differential Evolution Algorithm
NASA Astrophysics Data System (ADS)
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.
Post optimization paradigm in maximum 3-satisfiability logic programming
NASA Astrophysics Data System (ADS)
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.
Ozmutlu, H. Cenk
2014-01-01
We developed mixed integer programming (MIP) models and hybrid genetic-local search algorithms for the scheduling problem of unrelated parallel machines with job sequence and machine-dependent setup times and with job splitting property. The first contribution of this paper is to introduce novel algorithms which make splitting and scheduling simultaneously with variable number of subjobs. We proposed simple chromosome structure which is constituted by random key numbers in hybrid genetic-local search algorithm (GAspLA). Random key numbers are used frequently in genetic algorithms, but it creates additional difficulty when hybrid factors in local search are implemented. We developed algorithms that satisfy the adaptation of results of local search into the genetic algorithms with minimum relocation operation of genes' random key numbers. This is the second contribution of the paper. The third contribution of this paper is three developed new MIP models which are making splitting and scheduling simultaneously. The fourth contribution of this paper is implementation of the GAspLAMIP. This implementation let us verify the optimality of GAspLA for the studied combinations. The proposed methods are tested on a set of problems taken from the literature and the results validate the effectiveness of the proposed algorithms. PMID:24977204
Local dependence in random graph models: characterization, properties and statistical inference
Schweinberger, Michael; Handcock, Mark S.
2015-01-01
Summary Dependent phenomena, such as relational, spatial and temporal phenomena, tend to be characterized by local dependence in the sense that units which are close in a well-defined sense are dependent. In contrast with spatial and temporal phenomena, though, relational phenomena tend to lack a natural neighbourhood structure in the sense that it is unknown which units are close and thus dependent. Owing to the challenge of characterizing local dependence and constructing random graph models with local dependence, many conventional exponential family random graph models induce strong dependence and are not amenable to statistical inference. We take first steps to characterize local dependence in random graph models, inspired by the notion of finite neighbourhoods in spatial statistics and M-dependence in time series, and we show that local dependence endows random graph models with desirable properties which make them amenable to statistical inference. We show that random graph models with local dependence satisfy a natural domain consistency condition which every model should satisfy, but conventional exponential family random graph models do not satisfy. In addition, we establish a central limit theorem for random graph models with local dependence, which suggests that random graph models with local dependence are amenable to statistical inference. We discuss how random graph models with local dependence can be constructed by exploiting either observed or unobserved neighbourhood structure. In the absence of observed neighbourhood structure, we take a Bayesian view and express the uncertainty about the neighbourhood structure by specifying a prior on a set of suitable neighbourhood structures. We present simulation results and applications to two real world networks with ‘ground truth’. PMID:26560142
Optimizing spread dynamics on graphs by message passing
NASA Astrophysics Data System (ADS)
Altarelli, F.; Braunstein, A.; Dall'Asta, L.; Zecchina, R.
2013-09-01
Cascade processes are responsible for many important phenomena in natural and social sciences. Simple models of irreversible dynamics on graphs, in which nodes activate depending on the state of their neighbors, have been successfully applied to describe cascades in a large variety of contexts. Over the past decades, much effort has been devoted to understanding the typical behavior of the cascades arising from initial conditions extracted at random from some given ensemble. However, the problem of optimizing the trajectory of the system, i.e. of identifying appropriate initial conditions to maximize (or minimize) the final number of active nodes, is still considered to be practically intractable, with the only exception being models that satisfy a sort of diminishing returns property called submodularity. Submodular models can be approximately solved by means of greedy strategies, but by definition they lack cooperative characteristics which are fundamental in many real systems. Here we introduce an efficient algorithm based on statistical physics for the optimization of trajectories in cascade processes on graphs. We show that for a wide class of irreversible dynamics, even in the absence of submodularity, the spread optimization problem can be solved efficiently on large networks. Analytic and algorithmic results on random graphs are complemented by the solution of the spread maximization problem on a real-world network (the Epinions consumer reviews network).
Characteristics of neurogenic bowel in spinal cord injury and perceived quality of life.
Pardee, Connie; Bricker, Diedre; Rundquist, Jeanine; MacRae, Christi; Tebben, Cherisse
2012-01-01
To investigate the association between characteristics of individuals with spinal cord injury and neurogenic bowel and their perceived quality of life. The study design is an exploratory, descriptive correlational design. To measure the variables of the study the Quality of Life Survey developed by Randell et al. (2001) was used to measure perceived quality of life related to bowel management. Individual bowel management preferences and subjective costs and benefits of the preferences were gathered through the Neurogenic Bowel Characteristics Survey. PARTICIPANTS/METHOD: Data were collected from a random half of the individuals who met the inclusion criteria from the patient database (n=1193). Two hundred and forty one surveys were analyzed for this study. More than half of the sample (n=134) provided their own bowel management consisting of digital stimulation, suppositories, and other aids; 8% (n=19) had a colostomy. Regardless of the bowel management program 54% (n=127) were satisfied with current methods. Although time reported to complete bowel programs ranged from 1 to 120 minutes, there was no difference in rating of satisfaction with time. There was a statistically significant difference between those satisfied and dissatisfied with current bowel management and quality of life; those satisfied demonstrated a higher quality of life on three subscales, work function (p= .021), bowel problems (p< .001), and social function (p< .001). Those dissatisfied with their bowel program perceived a lower quality of life and indicated problems of time (p= .001), pain or discomfort (p= .033), and poor results (p< .001). Research data provide the patient's perspective on bowel management characteristics, complications, satisfaction, and their perceived quality of life. Results of this research will be incorporated into bowel management education and possible modification of the current inpatient bowel management program. © 2012 Association of Rehabilitation Nurses.
Diffusion Processes Satisfying a Conservation Law Constraint
Bakosi, J.; Ristorcelli, J. R.
2014-03-04
We investigate coupled stochastic differential equations governing N non-negative continuous random variables that satisfy a conservation principle. In various fields a conservation law requires that a set of fluctuating variables be non-negative 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 non-negativity and the unit-sum conservation law constraint are satisfied as the variables evolve in time. We investigate the consequencesmore » 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.« less
Diffusion Processes Satisfying a Conservation Law Constraint
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bakosi, J.; Ristorcelli, J. R.
We investigate coupled stochastic differential equations governing N non-negative continuous random variables that satisfy a conservation principle. In various fields a conservation law requires that a set of fluctuating variables be non-negative 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 non-negativity and the unit-sum conservation law constraint are satisfied as the variables evolve in time. We investigate the consequencesmore » 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.« less
Working with Perfectionist Students. ERIC Digest.
ERIC Educational Resources Information Center
Brophy, Jere
Perfectionist students are not satisfied with merely doing well or even with doing better than their peers. They are satisfied only if they have done a job perfectly. Problems associated with forms of perfectionism that focus on seeking success are relatively minor, but problems associated with forms of perfectionism that focus on avoiding failure…
A generalized complexity measure based on Rényi entropy
NASA Astrophysics Data System (ADS)
Sánchez-Moreno, Pablo; Angulo, Juan Carlos; Dehesa, Jesus S.
2014-08-01
The intrinsic statistical complexities of finite many-particle systems (i.e., those defined in terms of the single-particle density) quantify the degree of structure or patterns, far beyond the entropy measures. They are intuitively constructed to be minima at the opposite extremes of perfect order and maximal randomness. Starting from the pioneering LMC measure, which satisfies these requirements, some extensions of LMC-Rényi type have been published in the literature. The latter measures were shown to describe a variety of physical aspects of the internal disorder in atomic and molecular systems (e.g., quantum phase transitions, atomic shell filling) which are not grasped by their mother LMC quantity. However, they are not minimal for maximal randomness in general. In this communication, we propose a generalized LMC-Rényi complexity which overcomes this problem. Some applications which illustrate this fact are given.
A Direct Mapping of Max k-SAT and High Order Parity Checks to a Chimera Graph
Chancellor, N.; Zohren, S.; Warburton, P. A.; Benjamin, S. C.; Roberts, S.
2016-01-01
We demonstrate a direct mapping of max k-SAT problems (and weighted max k-SAT) to a Chimera graph, which is the non-planar hardware graph of the devices built by D-Wave Systems Inc. We further show that this mapping can be used to map a similar class of maximum satisfiability problems where the clauses are replaced by parity checks over potentially large numbers of bits. The latter is of specific interest for applications in decoding for communication. We discuss an example in which the decoding of a turbo code, which has been demonstrated to perform near the Shannon limit, can be mapped to a Chimera graph. The weighted max k-SAT problem is the most general class of satisfiability problems, so our result effectively demonstrates how any satisfiability problem may be directly mapped to a Chimera graph. Our methods faithfully reproduce the low energy spectrum of the target problems, so therefore may also be used for maximum entropy inference. PMID:27857179
Fuzzy probabilistic design of water distribution networks
NASA Astrophysics Data System (ADS)
Fu, Guangtao; Kapelan, Zoran
2011-05-01
The primary aim of this paper is to present a fuzzy probabilistic approach for optimal design and rehabilitation of water distribution systems, combining aleatoric and epistemic uncertainties in a unified framework. The randomness and imprecision in future water consumption are characterized using fuzzy random variables whose realizations are not real but fuzzy numbers, and the nodal head requirements are represented by fuzzy sets, reflecting the imprecision in customers' requirements. The optimal design problem is formulated as a two-objective optimization problem, with minimization of total design cost and maximization of system performance as objectives. The system performance is measured by the fuzzy random reliability, defined as the probability that the fuzzy head requirements are satisfied across all network nodes. The satisfactory degree is represented by necessity measure or belief measure in the sense of the Dempster-Shafer theory of evidence. An efficient algorithm is proposed, within a Monte Carlo procedure, to calculate the fuzzy random system reliability and is effectively combined with the nondominated sorting genetic algorithm II (NSGAII) to derive the Pareto optimal design solutions. The newly proposed methodology is demonstrated with two case studies: the New York tunnels network and Hanoi network. The results from both cases indicate that the new methodology can effectively accommodate and handle various aleatoric and epistemic uncertainty sources arising from the design process and can provide optimal design solutions that are not only cost-effective but also have higher reliability to cope with severe future uncertainties.
Analog Approach to Constraint Satisfaction Enabled by Spin Orbit Torque Magnetic Tunnel Junctions.
Wijesinghe, Parami; Liyanagedera, Chamika; Roy, Kaushik
2018-05-02
Boolean satisfiability (k-SAT) is an NP-complete (k ≥ 3) problem that constitute one of the hardest classes of constraint satisfaction problems. In this work, we provide a proof of concept hardware based analog k-SAT solver, that is built using Magnetic Tunnel Junctions (MTJs). The inherent physics of MTJs, enhanced by device level modifications, is harnessed here to emulate the intricate dynamics of an analog satisfiability (SAT) solver. In the presence of thermal noise, the MTJ based system can successfully solve Boolean satisfiability problems. Most importantly, our results exhibit that, the proposed MTJ based hardware SAT solver is capable of finding a solution to a significant fraction (at least 85%) of hard 3-SAT problems, within a time that has a polynomial relationship with the number of variables(<50).
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 age of five in a household, number of births in the past 5 years, wealth index, total number of children ever born and the child's birth order. The results further indicated that the predictive performance for random survival forests built using covariates including those that violate the PH assumption was higher than that for random survival forests built using only covariates that satisfy the PH assumption. Random survival forests are appealing methods in analysing public health data to understand factors strongly associated with under-five child mortality rates especially in the presence of covariates that violate the proportional hazards assumption.
Logical definability and asymptotic growth in optimization and counting problems
DOE Office of Scientific and Technical Information (OSTI.GOV)
Compton, K.
1994-12-31
There has recently been a great deal of interest in the relationship between logical definability and NP-optimization problems. Let MS{sub n} (resp. MP{sub n}) be the class of problems to compute, for given a finite structure A, the maximum number of tuples {bar x} in A satisfying a {Sigma}{sub n} (resp. II{sub n}) formula {psi}({bar x}, {bar S}) as {bar S} ranges over predicates on A. Kolaitis and Thakur showed that the classes MS{sub n} and MP{sub n} collapse to a hierarchy of four levels. Papadimitriou and Yannakakis previously showed that problems in the two lowest levels MS{sub 0} andmore » MS{sub 1} (which they called Max Snp and Max Np) are approximable to within a contrast factor in polynomial time. Similarly, Saluja, Subrahmanyam, and Thakur defined SS{sub n} (resp. SP{sub n}) to be the class of problems to compute, for given a finite structure A, the number of tuples ({bar T}, {bar S}) satisfying a given {Sigma}{sub n} (resp. II{sub n}) formula {psi}({bar T}, {bar c}) in A. They showed that the classes SS{sub n} and SP{sub n} collapse to a hierarchy of five levels and that problems in the two lowest levels SS{sub 0} and SS{sub 1} have a fully polynomial time randomized approximation scheme. We define extended classes MSF{sub n}, MPF{sub n} SSF{sub n}, and SPF{sub n} by allowing formulae to contain predicates definable in a logic known as least fixpoint logic. The resulting hierarchies classes collapse to the same number of levels and problems in the bottom levels can be approximated as before, but now some problems descend from the highest levels in the original hierarchies to the lowest levels in the new hierarchies. We introduce a method characterizing rates of growth of average solution sizes thereby showing a number of important problems do not belong MSF{sub 1} and SSF{sub 1}. This method is related to limit laws for logics and the probabilistic method from combinatorics.« less
Scott, J; Jennings, T; Standart, S; Ward, R; Goldberg, D
1999-01-01
BACKGROUND: The vast majority of mental health problems present to primary care teams. However, rates of under-diagnosis remain worryingly high. This study explores a GP-centred approach to these issues. AIM: To examine the impact of training in problem-based interviewing (BPI) on the detection and management of psychological problems in primary care. METHOD: The detection and management of psychological problems by 10 general practitioners (GPs) who had received PBI training 12 months earlier was compared with that of 10 control GPs matched for age, sex, clinical experience, and practice setting; and had originally applied for, but had not been able to attend, BPI training. Consecutive attendees at one randomly selected surgery undertaken by each GP were invited to participate in the study. Two hundred and eighty patients living in Newcastle upon Tyne met inclusion criteria and gave informed consent. The presence or absence of psychological problems was assessed using patient self-ratings on the 28-item version of the General Health Questionnaire (GHQ) and blind independent observer ratings of the brief Present State Examination (PSE). Patient satisfaction with interviews was rated using the Medical Interview Satisfaction Scale (MISS). After each consultation, the GPs (blind to subjective and observer ratings) recorded their assessment and management of the patients' problems on a Practice Activity Card (PAC). RESULTS: In comparison with control GPs, index GPs demonstrated significantly greater sensitivity in the detection of psychological problems in the GHQ-PAC ratings. The absolute decrease in misdiagnosis of GHQ cases was 9% and of PSE cases was 15%. Patients meeting GHQ criteria for caseness were more likely to be prescribed psychotropic medication by an index GP than compared with a control GP. Length of interview did not differ between the groups and mean scores on the MISS suggested that patients attending PBI-trained GPs, compared with control GPs, were as satisfied or slightly more satisfied with their consultation. CONCLUSION: In comparison with control GPs, PBI-trained GPs were better at recognizing and managing psychological disorders. The potential benefits of BPI training are discussed in light of other attempts to improve mental health skills in primary care. PMID:10562742
Syed Ali, M; Vadivel, R; Saravanakumar, R
2018-06-01
This study examines the problem of robust reliable control for Takagi-Sugeno (T-S) fuzzy Markovian jumping delayed neural networks with probabilistic actuator faults and leakage terms. An event-triggered communication scheme. First, the randomly occurring actuator faults and their failures rates are governed by two sets of unrelated random variables satisfying certain probabilistic failures of every actuator, new type of distribution based event triggered fault model is proposed, which utilize the effect of transmission delay. Second, Takagi-Sugeno (T-S) fuzzy model is adopted for the neural networks and the randomness of actuators failures is modeled in a Markov jump model framework. Third, to guarantee the considered closed-loop system is exponential mean square stable with a prescribed reliable control performance, a Markov jump event-triggered scheme is designed in this paper, which is the main purpose of our study. Fourth, by constructing appropriate Lyapunov-Krasovskii functional, employing Newton-Leibniz formulation and integral inequalities, several delay-dependent criteria for the solvability of the addressed problem are derived. The obtained stability criteria are stated in terms of linear matrix inequalities (LMIs), which can be checked numerically using the effective LMI toolbox in MATLAB. Finally, numerical examples are given to illustrate the effectiveness and reduced conservatism of the proposed results over the existing ones, among them one example was supported by real-life application of the benchmark problem. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.
Ontological Problem-Solving Framework for Dynamically Configuring Sensor Systems and Algorithms
Qualls, Joseph; Russomanno, David J.
2011-01-01
The deployment of ubiquitous sensor systems and algorithms has led to many challenges, such as matching sensor systems to compatible algorithms which are capable of satisfying a task. Compounding the challenges is the lack of the requisite knowledge models needed to discover sensors and algorithms and to subsequently integrate their capabilities to satisfy a specific task. A novel ontological problem-solving framework has been designed to match sensors to compatible algorithms to form synthesized systems, which are capable of satisfying a task and then assigning the synthesized systems to high-level missions. The approach designed for the ontological problem-solving framework has been instantiated in the context of a persistence surveillance prototype environment, which includes profiling sensor systems and algorithms to demonstrate proof-of-concept principles. Even though the problem-solving approach was instantiated with profiling sensor systems and algorithms, the ontological framework may be useful with other heterogeneous sensing-system environments. PMID:22163793
NASA Technical Reports Server (NTRS)
Arneson, Heather M.; Dousse, Nicholas; Langbort, Cedric
2014-01-01
We consider control design for positive compartmental systems in which each compartment's outflow rate is described by a concave function of the amount of material in the compartment.We address the problem of determining the routing of material between compartments to satisfy time-varying state constraints while ensuring that material reaches its intended destination over a finite time horizon. We give sufficient conditions for the existence of a time-varying state-dependent routing strategy which ensures that the closed-loop system satisfies basic network properties of positivity, conservation and interconnection while ensuring that capacity constraints are satisfied, when possible, or adjusted if a solution cannot be found. These conditions are formulated as a linear programming problem. Instances of this linear programming problem can be solved iteratively to generate a solution to the finite horizon routing problem. Results are given for the application of this control design method to an example problem. Key words: linear programming; control of networks; positive systems; controller constraints and structure.
The quantum-field renormalization group in the problem of a growing phase boundary
DOE Office of Scientific and Technical Information (OSTI.GOV)
Antonov, N.V.; Vasil`ev, A.N.
1995-09-01
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}charge{close_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 boundarymore » and time, {delta}{sub h} and {delta}{sub t}, which satisfy the exact relationship 2 {delta}{sub h}= {delta}{sub t} + d, where d is the dimensionality of the phase boundary. 23 refs., 1 tab.« less
Employing Sensitivity Derivatives for Robust Optimization under Uncertainty in CFD
NASA Technical Reports Server (NTRS)
Newman, Perry A.; Putko, Michele M.; Taylor, Arthur C., III
2004-01-01
A robust optimization is demonstrated on a two-dimensional inviscid airfoil problem in subsonic flow. Given uncertainties in statistically independent, random, normally distributed flow parameters (input variables), an approximate first-order statistical moment method is employed to represent the Computational Fluid Dynamics (CFD) code outputs as expected values with variances. These output quantities are used to form the objective function and constraints. The constraints are cast in probabilistic terms; that is, the probability that a constraint is satisfied is greater than or equal to some desired target probability. Gradient-based robust optimization of this stochastic problem is accomplished through use of both first and second-order sensitivity derivatives. For each robust optimization, the effect of increasing both input standard deviations and target probability of constraint satisfaction are demonstrated. This method provides a means for incorporating uncertainty when considering small deviations from input mean values.
RuHe DuiDai WanMei ZhuYi De XueSheng (Working with Perfectionist Students). ERIC Digest.
ERIC Educational Resources Information Center
Brophy, Jere
Perfectionist students are not satisfied with merely doing well or even with doing better than their peers. They are satisfied only if they have done a job perfectly. Problems associated with forms of perfectionism that focus on seeking success are relatively minor, but problems associated with forms of perfectionism that focus on avoiding failure…
NASA Astrophysics Data System (ADS)
Yan, Yifang; Yang, Chunyu; Ma, Xiaoping; Zhou, Linna
2018-02-01
In this paper, sampled-data H∞ filtering problem is considered for Markovian jump singularly perturbed systems with time-varying delay and missing measurements. The sampled-data system is represented by a time-delay system, and the missing measurement phenomenon is described by an independent Bernoulli random process. By constructing an ɛ-dependent stochastic Lyapunov-Krasovskii functional, delay-dependent sufficient conditions are derived such that the filter error system satisfies the prescribed H∞ performance for all possible missing measurements. Then, an H∞ filter design method is proposed in terms of linear matrix inequalities. Finally, numerical examples are given to illustrate the feasibility and advantages of the obtained results.
Minimal Increase Network Coding for Dynamic Networks.
Zhang, Guoyin; Fan, Xu; Wu, Yanxia
2016-01-01
Because of the mobility, computing power and changeable topology of dynamic networks, it is difficult for random linear network coding (RLNC) in static networks to satisfy the requirements of dynamic networks. To alleviate this problem, a minimal increase network coding (MINC) algorithm is proposed. By identifying the nonzero elements of an encoding vector, it selects blocks to be encoded on the basis of relationship between the nonzero elements that the controls changes in the degrees of the blocks; then, the encoding time is shortened in a dynamic network. The results of simulations show that, compared with existing encoding algorithms, the MINC algorithm provides reduced computational complexity of encoding and an increased probability of delivery.
Minimal Increase Network Coding for Dynamic Networks
Wu, Yanxia
2016-01-01
Because of the mobility, computing power and changeable topology of dynamic networks, it is difficult for random linear network coding (RLNC) in static networks to satisfy the requirements of dynamic networks. To alleviate this problem, a minimal increase network coding (MINC) algorithm is proposed. By identifying the nonzero elements of an encoding vector, it selects blocks to be encoded on the basis of relationship between the nonzero elements that the controls changes in the degrees of the blocks; then, the encoding time is shortened in a dynamic network. The results of simulations show that, compared with existing encoding algorithms, the MINC algorithm provides reduced computational complexity of encoding and an increased probability of delivery. PMID:26867211
Producing Satisfactory Solutions to Scheduling Problems: An Iterative Constraint Relaxation Approach
NASA Technical Reports Server (NTRS)
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.
A Simple Algorithm for the Metric Traveling Salesman Problem
NASA Technical Reports Server (NTRS)
Grimm, M. J.
1984-01-01
An algorithm was designed for a wire list net sort problem. A branch and bound algorithm for the metric traveling salesman problem is presented for this. The algorithm is a best bound first recursive descent where the bound is based on the triangle inequality. The bounded subsets are defined by the relative order of the first K of the N cities (i.e., a K city subtour). When K equals N, the bound is the length of the tour. The algorithm is implemented as a one page subroutine written in the C programming language for the VAX 11/750. Average execution times for randomly selected planar points using the Euclidean metric are 0.01, 0.05, 0.42, and 3.13 seconds for ten, fifteen, twenty, and twenty-five cities, respectively. Maximum execution times for a hundred cases are less than eleven times the averages. The speed of the algorithms is due to an initial ordering algorithm that is a N squared operation. The algorithm also solves the related problem where the tour does not return to the starting city and the starting and/or ending cities may be specified. It is possible to extend the algorithm to solve a nonsymmetric problem satisfying the triangle inequality.
Equilibrium problems for Raney densities
NASA Astrophysics Data System (ADS)
Forrester, Peter J.; Liu, Dang-Zheng; Zinn-Justin, Paul
2015-07-01
The Raney numbers are a class of combinatorial numbers generalising the Fuss-Catalan numbers. They are indexed by a pair of positive real numbers (p, r) with p > 1 and 0 < r ⩽ p, and form the moments of a probability density function. For certain (p, r) the latter has the interpretation as the density of squared singular values for certain random matrix ensembles, and in this context equilibrium problems characterising the Raney densities for (p, r) = (θ + 1, 1) and (θ/2 + 1, 1/2) have recently been proposed. Using two different techniques—one based on the Wiener-Hopf method for the solution of integral equations and the other on an analysis of the algebraic equation satisfied by the Green's function—we establish the validity of the equilibrium problems for general θ > 0 and similarly use both methods to identify the equilibrium problem for (p, r) = (θ/q + 1, 1/q), θ > 0 and q \\in Z+ . The Wiener-Hopf method is used to extend the latter to parameters (p, r) = (θ/q + 1, m + 1/q) for m a non-negative integer, and also to identify the equilibrium problem for a family of densities with moments given by certain binomial coefficients.
Large deviations in the random sieve
NASA Astrophysics Data System (ADS)
Grimmett, Geoffrey
1997-05-01
The proportion [rho]k of gaps with length k between square-free numbers is shown to satisfy log[rho]k=[minus sign](1+o(1))(6/[pi]2) klogk as k[rightward arrow][infty infinity]. Such asymptotics are consistent with Erdos's challenge to prove that the gap following the square-free number t is smaller than clogt/log logt, for all t and some constant c satisfying c>[pi]2/12. The results of this paper are achieved by studying the probabilities of large deviations in a certain ‘random sieve’, for which the proportions [rho]k have representations as probabilities. The asymptotic form of [rho]k may be obtained in situations of greater generality, when the squared primes are replaced by an arbitrary sequence (sr) of relatively prime integers satisfying [sum L: summation operator]r1/sr<[infty infinity], subject to two further conditions of regularity on this sequence.
NASA Astrophysics Data System (ADS)
Gong, Weiwei; Zhou, Xu
2017-06-01
In Computer Science, the Boolean Satisfiability Problem(SAT) is the problem of determining if there exists an interpretation that satisfies a given Boolean formula. SAT is one of the first problems that was proven to be NP-complete, which is also fundamental to artificial intelligence, algorithm and hardware design. This paper reviews the main algorithms of the SAT solver in recent years, including serial SAT algorithms, parallel SAT algorithms, SAT algorithms based on GPU, and SAT algorithms based on FPGA. The development of SAT is analyzed comprehensively in this paper. Finally, several possible directions for the development of the SAT problem are proposed.
Finer Distinctions: Variability in Satisfied Older Couples' Problem-Solving Behaviors.
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.
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.
Park, Yoo Jun
2012-01-01
Purpose 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. Materials and Methods 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. Results 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. Conclusions 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. PMID:22536469
Calibration of Lévy Processes with American Options
NASA Astrophysics Data System (ADS)
Achdou, Yves
We study options on financial assets whose discounted prices are exponential of Lévy processes. The price of an American vanilla option as a function of the maturity and the strike satisfies a linear complementarity problem involving a non-local partial integro-differential operator. It leads to a variational inequality in a suitable weighted Sobolev space. Calibrating the Lévy process may be done by solving an inverse least square problem where the state variable satisfies the previously mentioned variational inequality. We first assume that the volatility is positive: after carefully studying the direct problem, we propose necessary optimality conditions for the least square inverse problem. We also consider the direct problem when the volatility is zero.
Central limit theorem for recurrent random walks on a strip with bounded potential
NASA Astrophysics Data System (ADS)
Dolgopyat, D.; Goldsheid, I.
2018-07-01
We prove that the recurrent random walk (RW) in random environment (RE) on a strip in bounded potential satisfies the central limit theorem (CLT). The key ingredients of the proof are the analysis of the invariant measure equation and construction of a linearly growing martingale for walks in bounded potential. Our main result implies a complete classification of recurrent i.i.d. RWRE on the strip. Namely the walk either exhibits the Sinai behaviour in the sense that converges, as , to a (random) limit (the Sinai law) or, it satisfies the CLT. Another application of our main result is the CLT for the quasiperiodic environments with Diophantine frequencies in the recurrent case. We complement this result by proving that in the transient case the CLT holds for all uniquely ergodic environments. We also investigate the algebraic structure of the environments satisfying the CLT. In particular, we show that there exists a collection of proper algebraic subvarieties in the space of transition probabilities, such that: • If RE is stationary and ergodic and the transition probabilities are con-centrated on one of subvarieties from our collection then the CLT holds. • If the environment is i.i.d then the above condition is also necessary forthe CLT. All these results are valid for one-dimensional RWRE with bounded jumps as a particular case of the strip model.
Resource Optimization Scheme for Multimedia-Enabled Wireless Mesh Networks
Ali, Amjad; Ahmed, Muhammad Ejaz; Piran, Md. Jalil; Suh, Doug Young
2014-01-01
Wireless mesh networking is a promising technology that can support numerous multimedia applications. Multimedia applications have stringent quality of service (QoS) requirements, i.e., bandwidth, delay, jitter, and packet loss ratio. Enabling such QoS-demanding applications over wireless mesh networks (WMNs) require QoS provisioning routing protocols that lead to the network resource underutilization problem. Moreover, random topology deployment leads to have some unused network resources. Therefore, resource optimization is one of the most critical design issues in multi-hop, multi-radio WMNs enabled with multimedia applications. Resource optimization has been studied extensively in the literature for wireless Ad Hoc and sensor networks, but existing studies have not considered resource underutilization issues caused by QoS provisioning routing and random topology deployment. Finding a QoS-provisioned path in wireless mesh networks is an NP complete problem. In this paper, we propose a novel Integer Linear Programming (ILP) optimization model to reconstruct the optimal connected mesh backbone topology with a minimum number of links and relay nodes which satisfies the given end-to-end QoS demands for multimedia traffic and identification of extra resources, while maintaining redundancy. We further propose a polynomial time heuristic algorithm called Link and Node Removal Considering Residual Capacity and Traffic Demands (LNR-RCTD). Simulation studies prove that our heuristic algorithm provides near-optimal results and saves about 20% of resources from being wasted by QoS provisioning routing and random topology deployment. PMID:25111241
Resource optimization scheme for multimedia-enabled wireless mesh networks.
Ali, Amjad; Ahmed, Muhammad Ejaz; Piran, Md Jalil; Suh, Doug Young
2014-08-08
Wireless mesh networking is a promising technology that can support numerous multimedia applications. Multimedia applications have stringent quality of service (QoS) requirements, i.e., bandwidth, delay, jitter, and packet loss ratio. Enabling such QoS-demanding applications over wireless mesh networks (WMNs) require QoS provisioning routing protocols that lead to the network resource underutilization problem. Moreover, random topology deployment leads to have some unused network resources. Therefore, resource optimization is one of the most critical design issues in multi-hop, multi-radio WMNs enabled with multimedia applications. Resource optimization has been studied extensively in the literature for wireless Ad Hoc and sensor networks, but existing studies have not considered resource underutilization issues caused by QoS provisioning routing and random topology deployment. Finding a QoS-provisioned path in wireless mesh networks is an NP complete problem. In this paper, we propose a novel Integer Linear Programming (ILP) optimization model to reconstruct the optimal connected mesh backbone topology with a minimum number of links and relay nodes which satisfies the given end-to-end QoS demands for multimedia traffic and identification of extra resources, while maintaining redundancy. We further propose a polynomial time heuristic algorithm called Link and Node Removal Considering Residual Capacity and Traffic Demands (LNR-RCTD). Simulation studies prove that our heuristic algorithm provides near-optimal results and saves about 20% of resources from being wasted by QoS provisioning routing and random topology deployment.
[Bullying as health hazard among school children].
Due, E P; Holstein, B E; Jørgensen, P S
1999-04-12
The objective was to analyse bullying in relation to sociodemographic factors, health, well-being, and health behaviours. The study is the 1998 Danish contribution to the international WHO-coordinated study Health Behaviour in School-aged Children. It includes 5,205 11-15 year-old students from a random sample of 55 schools who answered a standardized questionnaire. Twenty-five percent were bullied several times during the academic year, most frequently among the youngest students, and independent of sex; 32% bullied others, boys more frequently than girls; the frequency increased with age. Bullying was associated with low social class. Bullying varied considerably among schools. The victims had more problems as regards health, well-being and self-esteem; they smoked and drank less than others. Those who bullied others also had more problems but to a much smaller extent than the victims. They had higher levels of risk behaviours such as smoking, drinking, and seat-belt avoidance, and were less satisfied with school. In conclusion, victims of bullying have a very high proportion of health problems, poor well-being and low self-esteem. To bully others is significantly associated with health risk behaviours.
Luczynski, Kevin C; Hanley, Gregory P
2013-01-01
We evaluated the effects of the preschool life skills program (PLS; Hanley, Heal, Tiger, & Ingvarsson, 2007) on the acquisition and maintenance of functional communication and self-control skills, as well as its effect on problem behavior, of small groups of preschoolers at risk for school failure. Six children were taught to request teacher attention, teacher assistance, and preferred materials, and to tolerate delays to and denial of those events during child-led, small-group activities. Teaching strategies included instruction, modeling, role play, and differential reinforcement. Six additional children randomly assigned to similarly sized control groups participated in small-group activities but did not experience the PLS program. Within-subject and between-groups designs showed that the PLS teaching procedures were functionally related to the improvements and maintenance of the skills and prevention of problem behavior. Stakeholder responses on a social acceptability questionnaire indicated that they were satisfied with the form of the targeted social skills, the improvements in the children's performance, and the teaching strategies. © Society for the Experimental Analysis of Behavior.
A spectral mimetic least-squares method
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bochev, Pavel; Gerritsma, Marc
We present a spectral mimetic least-squares method for a model diffusion–reaction problem, which preserves key conservation properties of the continuum problem. Casting the model problem into a first-order system for two scalar and two vector variables shifts material properties from the differential equations to a pair of constitutive relations. We also use this system to motivate a new least-squares functional involving all four fields and show that its minimizer satisfies the differential equations exactly. Discretization of the four-field least-squares functional by spectral spaces compatible with the differential operators leads to a least-squares method in which the differential equations are alsomore » satisfied exactly. Additionally, the latter are reduced to purely topological relationships for the degrees of freedom that can be satisfied without reference to basis functions. Furthermore, numerical experiments confirm the spectral accuracy of the method and its local conservation.« less
A spectral mimetic least-squares method
Bochev, Pavel; Gerritsma, Marc
2014-09-01
We present a spectral mimetic least-squares method for a model diffusion–reaction problem, which preserves key conservation properties of the continuum problem. Casting the model problem into a first-order system for two scalar and two vector variables shifts material properties from the differential equations to a pair of constitutive relations. We also use this system to motivate a new least-squares functional involving all four fields and show that its minimizer satisfies the differential equations exactly. Discretization of the four-field least-squares functional by spectral spaces compatible with the differential operators leads to a least-squares method in which the differential equations are alsomore » satisfied exactly. Additionally, the latter are reduced to purely topological relationships for the degrees of freedom that can be satisfied without reference to basis functions. Furthermore, numerical experiments confirm the spectral accuracy of the method and its local conservation.« less
Observers for a class of systems with nonlinearities satisfying an incremental quadratic inequality
NASA Technical Reports Server (NTRS)
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.
NASA Technical Reports Server (NTRS)
Voigt, Kerstin
1992-01-01
We present MENDER, a knowledge based system that implements software design techniques that are specialized to automatically compile generate-and-patch problem solvers that satisfy global resource assignments problems. We provide empirical evidence of the superior performance of generate-and-patch over generate-and-test: even with constrained generation, for a global constraint in the domain of '2D-floorplanning'. For a second constraint in '2D-floorplanning' we show that even when it is possible to incorporate the constraint into a constrained generator, a generate-and-patch problem solver may satisfy the constraint more rapidly. We also briefly summarize how an extended version of our system applies to a constraint in the domain of 'multiprocessor scheduling'.
Temesgen, Kalkidan; Aycheh, Moges Wubie; Leshargie, Cheru Tesema
2018-04-17
In Ethiopia assuring the satisfaction of health care provider with their job is a major challenging problem. Job satisfaction is a worker's emotional response to different job related factors resulting in finding pleasure, comfort, confidence, rewards, personal growth and various positive opportunities, including upward mobility, recognition, and appraisal done on a merit pattern with monetary value as compensation. Professionals, whose needs and expectations are satisfied, tend to be more productive compared to their colleagues. Thus, study is aimed at assessing job satisfaction and associated factors among health professionals working at Western Amhara region, Ethiopia. An institution-based cross sectional study was conducted on March 2016 at Western Amhara region among 575 health professionals selected using simple random sampling. Logistic regression analysis was used to identify factors related to job satisfaction. Variables which have p-value less than or equal to 0.05 with corresponding AOR at 95 confidence interval was considered to declare the significance association. This study revealed that job satisfaction of health professional working at Western Amhara region was 31.7%. The mean age of respondent was 27.13 years. Majority of them, 79.3% and 95.3% were less than 30 years in age and orthodox Christian religion followers respectively. The presence of health professionals' reference manual/guide, alcohol drinking, workload, experience, educational status and profession types were identified as significant factors associated with health care professionals' job satisfaction level. Professional being laboratory technicians, pharmacists and Environmental health workers were 4.86 times more likely to satisfy themselves than nurses, midwives and Public health officers. Similarly, in their educational status, degree and above holders were 5.64 times more likely to satisfy themselves than below degree holders. Health professionals whose experience with > 3 years were 2.83 times more likely to satisfy themselves than counterpart. Health professionals who had high workloads were 3.99 times more likely to satisfy than those professionals whose workload was low. Professionals who did not drink alcohol were 3.55 times more likely to satisfy themselves than professionals who drank. Professionals who consult health reference manual/guide were 15.96 more likely to satisfy themselves than those professional who did not. Only one third of health professionals working at Eastern Amhara Region were satisfied on their job. The presence of health professionals' reference manual/guide, alcohol drinking, workload, experience, educational status and profession types were identified as important predictors for job satisfaction.
Solution to the satisfiability problem using a complete Grover search with trapped ions
NASA Astrophysics Data System (ADS)
Yang, Wan-Li; Wei, Hua; Zhou, Fei; Chang, Weng-Long; Feng, Mang
2009-07-01
The main idea in the original Grover search (1997 Phys. Rev. Lett. 79 325) is to single out a target state containing the solution to a search problem by amplifying the amplitude of the state, following the Oracle's job, i.e., a black box giving us information about the target state. We design quantum circuits to accomplish a complete Grover search involving both the Oracle's job and the amplification of the target state, which are employed to solve satisfiability (SAT) problems. We explore how to carry out the quantum circuits with currently available ion-trap quantum computing technology.
Perceived barriers to consumption of fish among Norwegian women.
Trondsen, Torbjørn; Scholderer, Joachim; Lund, Eiliv; Eggen, Anne E
2003-12-01
This study aimed to characterize constraints on consumption of fish perceived by consumers in Norway. A random sample of Norwegian women aged 45-69 years answered a self-administered mail questionnaire in 1996 about eating habits, perceived barriers to fish consumption, socioeconomic status, and questions related to health. Altogether, 9407 women answered the questionnaire (response rate: 52.5%). Data were analyzed by means of logistic regression. Limited supply of fish products that satisfy children's wishes reduce at-home fish consumption. People with health problems and those who wish to lose weight are dissatisfied with the range of products offered in the marketplace. Satisfaction with quality and availability of wild lean codfish, especially in inland regions, is lower than for aqua-cultured fat salmon. Neither income nor education or health factors were significantly associated with consumption levels among those who would like to eat more fish. Higher education and income were associated with increased dissatisfaction about fish consumption, but also with reduced perception of most barriers. It is concluded that improvements in the supply of high-quality fresh and processed fish products that satisfy (a) children's wishes, (b) health-oriented family members, and (c) convenience-oriented consumers, will significantly increase at-home consumption of fish.
Correlated random walks induced by dynamical wavefunction collapse
NASA Astrophysics Data System (ADS)
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.
Constructing space difference schemes which satisfy a cell entropy inequality
NASA Technical Reports Server (NTRS)
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.
Two-Stage Path Planning Approach for Designing Multiple Spacecraft Reconfiguration Maneuvers
NASA Technical Reports Server (NTRS)
Aoude, Georges S.; How, Jonathan P.; Garcia, Ian M.
2007-01-01
The paper presents a two-stage approach for designing optimal reconfiguration maneuvers for multiple spacecraft. These maneuvers involve well-coordinated and highly-coupled motions of the entire fleet of spacecraft while satisfying an arbitrary number of constraints. This problem is particularly difficult because of the nonlinearity of the attitude dynamics, the non-convexity of some of the constraints, and the coupling between the positions and attitudes of all spacecraft. As a result, the trajectory design must be solved as a single 6N DOF problem instead of N separate 6 DOF problems. The first stage of the solution approach quickly provides a feasible initial solution by solving a simplified version without differential constraints using a bi-directional Rapidly-exploring Random Tree (RRT) planner. A transition algorithm then augments this guess with feasible dynamics that are propagated from the beginning to the end of the trajectory. The resulting output is a feasible initial guess to the complete optimal control problem that is discretized in the second stage using a Gauss pseudospectral method (GPM) and solved using an off-the-shelf nonlinear solver. This paper also places emphasis on the importance of the initialization step in pseudospectral methods in order to decrease their computation times and enable the solution of a more complex class of problems. Several examples are presented and discussed.
Space and time in the quantum universe.
NASA Astrophysics Data System (ADS)
Smolin, L.
This paper is devoted to the problem of constructing a quantum theory that could describe a closed system - a quantum cosmology. The author argues that this problem is an aspect of a much older problem - that of how to eliminate from the physical theories "ideal elements", which are elements of the mathematical structure whose interpretation requires the existence of things outside the dynamical system described by the theory. This discussion is aimed at uncovering criteria that a theory of quantum cosmology must satisfy, if it is to give physically sensible predictions. The author proposes three such criteria and shows that conventional quantum cosmology can only satisfy them, if there is an intrinsic time coordinate on the phase space of the theory. It is shown that approaches based on correlations in the wave function, that do not use an inner product, cannot satisfy these criteria. As example, the author discusses the problem of quantizing a class of relational dynamical models invented by Barbour and Bertotti. The dynamical structure of these theories is closely analogous to general relativity, and the problem of their measurement theory is also similar. It is concluded that these theories can only be sensibly quantized if they contain an intrinsic time.
Efficiency of the strong satisfiability checking procedure for reactive system specifications
NASA Astrophysics Data System (ADS)
Shimakawa, Masaya; Hagihara, Shigeki; Yonezaki, Naoki
2018-04-01
Reactive systems are those that interact with their environment. To develop reactive systems without defects, it is important to describe behavior specifications in a formal language, such as linear temporal logic, and to verify the specification. Specifically, it is important to check whether specifications satisfy the property called realizability. In previous studies, we have proposed the concept of strong satisfiability as a necessary condition for realizability. Although this property of reactive system specifications is a necessary condition, many practical unrealizable specifications are also strongly unsatisfiable. Moreover, we have previously shown the theoretical complexity of the strong satisfiability problem. In the current study, we investigate the practical efficiency of the strong satisfiability checking procedure and demonstrate that strong satisfiability can be checked more efficiently than realizability.
A general optimality criteria algorithm for a class of engineering optimization problems
NASA Astrophysics Data System (ADS)
Belegundu, Ashok D.
2015-05-01
An optimality criteria (OC)-based algorithm for optimization of a general class of nonlinear programming (NLP) problems is presented. The algorithm is only applicable to problems where the objective and constraint functions satisfy certain monotonicity properties. For multiply constrained problems which satisfy these assumptions, the algorithm is attractive compared with existing NLP methods as well as prevalent OC methods, as the latter involve computationally expensive active set and step-size control strategies. The fixed point algorithm presented here is applicable not only to structural optimization problems but also to certain problems as occur in resource allocation and inventory models. Convergence aspects are discussed. The fixed point update or resizing formula is given physical significance, which brings out a strength and trim feature. The number of function evaluations remains independent of the number of variables, allowing the efficient solution of problems with large number of variables.
Satisfiability modulo theory and binary puzzle
NASA Astrophysics Data System (ADS)
Utomo, Putranto
2017-06-01
The binary puzzle is a sudoku-like puzzle with values in each cell taken from the set {0, 1}. We look at the mathematical theory behind it. A solved binary puzzle is an n × n binary array where n is even that satisfies the following conditions: (1) No three consecutive ones and no three consecutive zeros in each row and each column, (2) Every row and column is balanced, that is the number of ones and zeros must be equal in each row and in each column, (3) Every two rows and every two columns must be distinct. The binary puzzle had been proven to be an NP-complete problem [5]. Research concerning the satisfiability of formulas with respect to some background theory is called satisfiability modulo theory (SMT). An SMT solver is an extension of a satisfiability (SAT) solver. The notion of SMT can be used for solving various problem in mathematics and industries such as formula verification and operation research [1, 7]. In this paper we apply SMT to solve binary puzzles. In addition, we do an experiment in solving different sizes and different number of blanks. We also made comparison with two other approaches, namely by a SAT solver and exhaustive search.
Qualls, Joseph; Russomanno, David J.
2011-01-01
The lack of knowledge models to represent sensor systems, algorithms, and missions makes opportunistically discovering a synthesis of systems and algorithms that can satisfy high-level mission specifications impractical. A novel ontological problem-solving framework has been designed that leverages knowledge models describing sensors, algorithms, and high-level missions to facilitate automated inference of assigning systems to subtasks that may satisfy a given mission specification. To demonstrate the efficacy of the ontological problem-solving architecture, a family of persistence surveillance sensor systems and algorithms has been instantiated in a prototype environment to demonstrate the assignment of systems to subtasks of high-level missions. PMID:22164081
Problem-based learning versus lecture-based learning in postgraduate medical education.
Smits, Paul B; de Buisonjé, Cathelijn D; Verbeek, Jos H; van Dijk, Frank J; Metz, Jaap C; ten Cate, Olle J
2003-08-01
The objective of this study was to investigate the effectiveness of problem-based learning in comparison with lecture-based learning in a postgraduate medical training program concerning the management of mental health problems for occupational health physicians. A randomized controlled trial in 1999, with a mean follow-up of 14 months after the educational intervention, was used involving postgraduate medical education and training for occupational health physicians in The Netherlands, with 118 physicians in training as occupational health physicians. The experimental program was based on the principles of problem-based learning; the control program used the traditional lecture-based approach. Both programs were aimed at improving knowledge of and performance in the occupational management of work-related mental health problems. As the main outcome measures, knowledge tests consisting of true-or-false and open-answer questions and performance in practice based on self-reports and performance indicators were used. Satisfaction with the course was rated by the participants. In both groups, knowledge had increased equally directly after the programs and decreased equally after the follow-up. The gain in knowledge remained positive. The performance indicator scores also increased in both groups, but significantly more so in the problem-based group. The problem-based group was less satisfied with the course. Both forms of postgraduate medical training are effective. In spite of less favorable evaluations, the problem-based program appeared to be more effective than the lecture-based program in improving performance. Both programs, however, were equally effective in improving knowledge levels.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Huang, Kuo -Ling; Mehrotra, Sanjay
We present a homogeneous algorithm equipped with a modified potential function for the monotone complementarity problem. We show that this potential function is reduced by at least a constant amount if a scaled Lipschitz condition (SLC) is satisfied. A practical algorithm based on this potential function is implemented in a software package named iOptimize. The implementation in iOptimize maintains global linear and polynomial time convergence properties, while achieving practical performance. It either successfully solves the problem, or concludes that the SLC is not satisfied. When compared with the mature software package MOSEK (barrier solver version 6.0.0.106), iOptimize solves convex quadraticmore » programming problems, convex quadratically constrained quadratic programming problems, and general convex programming problems in fewer iterations. Moreover, several problems for which MOSEK fails are solved to optimality. In addition, we also find that iOptimize detects infeasibility more reliably than the general nonlinear solvers Ipopt (version 3.9.2) and Knitro (version 8.0).« less
Random sequences generation through optical measurements by phase-shifting interferometry
NASA Astrophysics Data System (ADS)
François, M.; Grosges, T.; Barchiesi, D.; Erra, R.; Cornet, A.
2012-04-01
The development of new techniques for producing random sequences with a high level of security is a challenging topic of research in modern cryptographics. The proposed method is based on the measurement by phase-shifting interferometry of the speckle signals of the interaction between light and structures. We show how the combination of amplitude and phase distributions (maps) under a numerical process can produce random sequences. The produced sequences satisfy all the statistical requirements of randomness and can be used in cryptographic schemes.
Wachtel, Ruth E.; Dexter, Franklin
2010-01-01
Background 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. Intervention 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. Findings 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. Conclusions 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. PMID:22132289
Quantum Adiabatic Algorithms and Large Spin Tunnelling
NASA Technical Reports Server (NTRS)
Boulatov, A.; Smelyanskiy, V. N.
2003-01-01
We provide a theoretical study of the quantum adiabatic evolution algorithm with different evolution paths proposed in this paper. The algorithm is applied to a random binary optimization problem (a version of the 3-Satisfiability problem) where the n-bit cost function is symmetric with respect to the permutation of individual bits. The evolution paths are produced, using the generic control Hamiltonians H (r) that preserve the bit symmetry of the underlying optimization problem. In the case where the ground state of H(0) coincides with the totally-symmetric state of an n-qubit system the algorithm dynamics is completely described in terms of the motion of a spin-n/2. We show that different control Hamiltonians can be parameterized by a set of independent parameters that are expansion coefficients of H (r) in a certain universal set of operators. Only one of these operators can be responsible for avoiding the tunnelling in the spin-n/2 system during the quantum adiabatic algorithm. We show that it is possible to select a coefficient for this operator that guarantees a polynomial complexity of the algorithm for all problem instances. We show that a successful evolution path of the algorithm always corresponds to the trajectory of a classical spin-n/2 and provide a complete characterization of such paths.
Drag Minimization for Wings and Bodies in Supersonic Flow
NASA Technical Reports Server (NTRS)
Heaslet, Max A; Fuller, Franklyn B
1958-01-01
The minimization of inviscid fluid drag is studied for aerodynamic shapes satisfying the conditions of linearized theory, and subject to imposed constraints on lift, pitching moment, base area, or volume. The problem is transformed to one of determining two-dimensional potential flows satisfying either Laplace's or Poisson's equations with boundary values fixed by the imposed conditions. A general method for determining integral relations between perturbation velocity components is developed. This analysis is not restricted in application to optimum cases; it may be used for any supersonic wing problem.
Two solvable problems of planar geometrical optics.
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.
Two Methods for Efficient Solution of the Hitting-Set Problem
NASA Technical Reports Server (NTRS)
Vatan, Farrokh; Fijany, Amir
2005-01-01
A paper addresses much of the same subject matter as that of Fast Algorithms for Model-Based Diagnosis (NPO-30582), which appears elsewhere in this issue of NASA Tech Briefs. However, in the paper, the emphasis is more on the hitting-set problem (also known as the transversal problem), which is well known among experts in combinatorics. The authors primary interest in the hitting-set problem lies in its connection to the diagnosis problem: it is a theorem of model-based diagnosis that in the set-theory representation of the components of a system, the minimal diagnoses of a system are the minimal hitting sets of the system. In the paper, the hitting-set problem (and, hence, the diagnosis problem) is translated from a combinatorial to a computational problem by mapping it onto the Boolean satisfiability and integer- programming problems. The paper goes on to describe developments nearly identical to those summarized in the cited companion NASA Tech Briefs article, including the utilization of Boolean-satisfiability and integer- programming techniques to reduce the computation time and/or memory needed to solve the hitting-set problem.
Fingerprints selection for topological localization
NASA Astrophysics Data System (ADS)
Popov, Vladimir
2017-07-01
Problems of visual navigation are extensively studied in contemporary robotics. In particular, we can mention different problems of visual landmarks selection, the problem of selection of a minimal set of visual landmarks, selection of partially distinguishable guards, the problem of placement of visual landmarks. In this paper, we consider one-dimensional color panoramas. Such panoramas can be used for creating fingerprints. Fingerprints give us unique identifiers for visually distinct locations by recovering statistically significant features. Fingerprints can be used as visual landmarks for the solution of various problems of mobile robot navigation. In this paper, we consider a method for automatic generation of fingerprints. In particular, we consider the bounded Post correspondence problem and applications of the problem to consensus fingerprints and topological localization. We propose an efficient approach to solve the bounded Post correspondence problem. In particular, we use an explicit reduction from the decision version of the problem to the satisfiability problem. We present the results of computational experiments for different satisfiability algorithms. In robotic experiments, we consider the average accuracy of reaching of the target point for different lengths of routes and types of fingerprints.
Ranking Specific Sets of Objects.
Maly, Jan; Woltran, Stefan
2017-01-01
Ranking sets of objects based on an order between the single elements has been thoroughly studied in the literature. In particular, it has been shown that it is in general impossible to find a total ranking - jointly satisfying properties as dominance and independence - on the whole power set of objects. However, in many applications certain elements from the entire power set might not be required and can be neglected in the ranking process. For instance, certain sets might be ruled out due to hard constraints or are not satisfying some background theory. In this paper, we treat the computational problem whether an order on a given subset of the power set of elements satisfying different variants of dominance and independence can be found, given a ranking on the elements. We show that this problem is tractable for partial rankings and NP-complete for total rankings.
Huang, Kuo -Ling; Mehrotra, Sanjay
2016-11-08
We present a homogeneous algorithm equipped with a modified potential function for the monotone complementarity problem. We show that this potential function is reduced by at least a constant amount if a scaled Lipschitz condition (SLC) is satisfied. A practical algorithm based on this potential function is implemented in a software package named iOptimize. The implementation in iOptimize maintains global linear and polynomial time convergence properties, while achieving practical performance. It either successfully solves the problem, or concludes that the SLC is not satisfied. When compared with the mature software package MOSEK (barrier solver version 6.0.0.106), iOptimize solves convex quadraticmore » programming problems, convex quadratically constrained quadratic programming problems, and general convex programming problems in fewer iterations. Moreover, several problems for which MOSEK fails are solved to optimality. In addition, we also find that iOptimize detects infeasibility more reliably than the general nonlinear solvers Ipopt (version 3.9.2) and Knitro (version 8.0).« less
Bullied children and psychosomatic problems: a meta-analysis.
Gini, Gianluca; Pozzoli, Tiziana
2013-10-01
A previous meta-analysis showed that being bullied during childhood is related to psychosomatic problems, but many other studies have been published since then, including some longitudinal studies. We performed a new meta-analysis to quantify the association between peer victimization and psychosomatic complaints in the school-aged population. We searched online databases up to April 2012, and bibliographies of retrieved studies and of narrative reviews, for studies that examined the association between being bullied and psychosomatic complaints in children and adolescents. The original search identified 119 nonduplicated studies, of which 30 satisfied the prestated inclusion criteria. Two separate random effects meta-analyses were performed on 6 longitudinal studies (odds ratio = 2.39, 95% confidence interval, 1.76 to 3.24) and 24 cross-sectional studies (odds ratio = 2.17, 95% confidence interval, 1.91 to 2.46), respectively. Results showed that bullied children and adolescents have a significantly higher risk for psychosomatic problems than non-bullied agemates. In the cross-sectional studies, the magnitude of effect size significantly decreased with the increase of the proportion of female participants in the study sample. No other moderators were statistically significant. The association between being bullied and psychosomatic problems was confirmed. Given that school bullying is a widespread phenomenon in many countries around the world, the present results indicate that bullying should be considered a significant international public health problem.
Patient satisfaction 8-14 years after dental implant therapy - a questionnaire study.
Adler, Lottie; Liedholm, Eva; Silvegren, Malin; Modin, Carolina; Buhlin, Kåre; Jansson, Leif
2016-07-01
The aim of this questionnaire study was to investigate patient satisfaction 8-14 years after dental implant therapy and complications influencing the degree of satisfaction. A questionnaire was sent by post to 587 patients at a specialist clinic of periodontology. The questionnaire consisted of 19 statements or questions such as the degree of satisfaction with the implants and knowledge of complications. In nine of the questions, respondents were asked to grade the extent of their agreement with a statement by selecting from fixed answers. Three of the questions were designed to be answered using a visual analog scale. In total, 400 individuals (81%) responded to the questionnaire. The mean time elapsed since implant installation was 10 years. A great majority (81%) experienced a high chewing comfort and was satisfied or sufficiently satisfied (94%) with the aesthetic aspects of their implant restorations, while 32% of the individuals had experienced problems with their implant reconstructions. The disadvantage that patients remarked on was the cost of the treatment. Those who had experienced problems with their implant reconstructions were also less satisfied with the treatment. A great majority of the patients expressed a high degree of satisfaction with their dental implants 8-14 years after the treatment. Patients were less satisfied if they had experience of problems with their implant reconstructions and in cases when the clinicians were unable to resolve their complications.
Brief interventions to reduce Ecstasy use: a multi-site randomized controlled trial.
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 suggest new methods for enhancing outcomes. Australia and New Zealand Clinical Trial Registry: ACTRN12611000136909. Copyright © 2014. Published by Elsevier Ltd.
Cross-layer Joint Relay Selection and Power Allocation Scheme for Cooperative Relaying System
NASA Astrophysics Data System (ADS)
Zhi, Hui; He, Mengmeng; Wang, Feiyue; Huang, Ziju
2018-03-01
A novel cross-layer joint relay selection and power allocation (CL-JRSPA) scheme over physical layer and data-link layer is proposed for cooperative relaying system in this paper. Our goal is finding the optimal relay selection and power allocation scheme to maximize system achievable rate when satisfying total transmit power constraint in physical layer and statistical delay quality-of-service (QoS) demand in data-link layer. Using the concept of effective capacity (EC), our goal can be formulated into an optimal joint relay selection and power allocation (JRSPA) problem to maximize the EC when satisfying total transmit power limitation. We first solving optimal power allocation (PA) problem with Lagrange multiplier approach, and then solving optimal relay selection (RS) problem. Simulation results demonstrate that CL-JRSPA scheme gets larger EC than other schemes when satisfying delay QoS demand. In addition, the proposed CL-JRSPA scheme achieves the maximal EC when relay located approximately halfway between source and destination, and EC becomes smaller when the QoS exponent becomes larger.
Calculating radiotherapy margins based on Bayesian modelling of patient specific random errors
NASA Astrophysics Data System (ADS)
Herschtal, A.; te Marvelde, L.; Mengersen, K.; Hosseinifard, Z.; Foroudi, F.; Devereux, T.; Pham, D.; Ball, D.; Greer, P. B.; Pichler, P.; Eade, T.; Kneebone, A.; Bell, L.; Caine, H.; Hindson, B.; Kron, T.
2015-02-01
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.
Gender differences in algebraic thinking ability to solve mathematics problems
NASA Astrophysics Data System (ADS)
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.
The effects of sterilisation: a comparison of sterilised women with the wives of vasectomised men.
Alder, E; Cook, A; Gray, J; Tyrer, G; Warner, P; Bancroft, J; Loudon, N B; Loudon, J
1981-01-01
In a follow-up study, women sterilised by tubal diathermy were compared with a matched group of wives of vasectomised men. Semi-structured interviews were given to a random sample drawn from a representative population. The couples were young with small families and did not have a high proportion of unplanned pregnancies or terminations. They had previously used contraception, mainly the pill or sheath. Most couples were entirely satisfied with the operation. Both groups showed an increase in pre-menstrual symptoms but there was only slight evidence that menstrual loss was affected by female sterilisation. The vasectomy couples had a higher frequency of sexual intercourse, few sexual problems and tended to have more satisfactory marriages. They had had more discussion of their decision to have the operation and the implications of counselling are considered.
Making Training a Rewarding Experience for Offshore Drilling Personnel at Diamond M Company.
ERIC Educational Resources Information Center
Zambon, Franco
The problems of the training departments of offshore drilling companies are to determine novel rewards for trainees and to use these rewards correctly. Rewards are motivators and real or apparent satisfiers of needs. For some instructional goals, computer-based training satisfies many needs and applies many motivators to hold the trainee's…
Hybrid genetic algorithm in the Hopfield network for maximum 2-satisfiability problem
NASA Astrophysics Data System (ADS)
Kasihmuddin, Mohd Shareduwan Mohd; Sathasivam, Saratha; Mansor, Mohd. Asyraf
2017-08-01
Heuristic method was designed for finding optimal solution more quickly compared to classical methods which are too complex to comprehend. In this study, a hybrid approach that utilizes Hopfield network and genetic algorithm in doing maximum 2-Satisfiability problem (MAX-2SAT) was proposed. Hopfield neural network was used to minimize logical inconsistency in interpretations of logic clauses or program. Genetic algorithm (GA) has pioneered the implementation of methods that exploit the idea of combination and reproduce a better solution. The simulation incorporated with and without genetic algorithm will be examined by using Microsoft Visual 2013 C++ Express software. The performance of both searching techniques in doing MAX-2SAT was evaluate based on global minima ratio, ratio of satisfied clause and computation time. The result obtained form the computer simulation demonstrates the effectiveness and acceleration features of genetic algorithm in doing MAX-2SAT in Hopfield network.
Pre-service mathematics teachers’ ability in solving well-structured problem
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
Zhou, Chenyi; Guo, Hong
2017-01-01
We report a diagrammatic method to solve the general problem of calculating configurationally averaged Green's function correlators that appear in quantum transport theory for nanostructures containing disorder. The theory treats both equilibrium and nonequilibrium quantum statistics on an equal footing. Since random impurity scattering is a problem that cannot be solved exactly in a perturbative approach, we combine our diagrammatic method with the coherent potential approximation (CPA) so that a reliable closed-form solution can be obtained. Our theory not only ensures the internal consistency of the diagrams derived at different levels of the correlators but also satisfies a set of Ward-like identities that corroborate the conserving consistency of transport calculations within the formalism. The theory is applied to calculate the quantum transport properties such as average ac conductance and transmission moments of a disordered tight-binding model, and results are numerically verified to high precision by comparing to the exact solutions obtained from enumerating all possible disorder configurations. Our formalism can be employed to predict transport properties of a wide variety of physical systems where disorder scattering is important.
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.
Job satisfaction among primary care physicians: results of a survey.
Behmann, Mareike; Schmiemann, Guido; Lingner, Heidrun; Kühne, Franziska; Hummers-Pradier, Eva; Schneider, Nils
2012-03-01
A shortage of primary care physicians (PCPs) seems likely in Germany in the near future and already exists in some parts of the country. Many currently practicing PCPs will soon reach retirement age, and recruiting young physicians for family practice is difficult. The attractiveness of primary care for young physicians depends on the job satisfaction of currently practicing PCPs. We studied job satisfaction among PCPs in Lower Saxony, a large federal state in Germany. In 2009, we sent a standardized written questionnaire on overall job satisfaction and on particular aspects of medical practice to 3296 randomly chosen PCPs and internists in family practice in Lower Saxony (50% of the entire target population). 1106 physicians (34%) responded; their mean age was 52, and 69% were men. 64% said they were satisfied or very satisfied with their job overall. There were particularly high rates of satisfaction with patient contact (91%) and working atmosphere (87% satisfied or very satisfied). In contrast, there were high rates of dissatisfaction with administrative tasks (75% dissatisfied or not at all satisfied). The results were more indifferent concerning payment and work life balance. Overall, younger PCPs and physicians just entering practice were more satisfied than their older colleagues who had been in practice longer. PCPs are satisfied with their job overall. However, there is significant dissatisfaction with administrative tasks. Improvements in this area may contribute to making primary care more attractive to young physicians.
Yao, Shengnan; Zeng, Weiming; Wang, Nizhuan; Chen, Lei
2013-07-01
Independent component analysis (ICA) has been proven to be effective for functional magnetic resonance imaging (fMRI) data analysis. However, ICA decomposition requires to optimize the unmixing matrix iteratively whose initial values are generated randomly. Thus the randomness of the initialization leads to different ICA decomposition results. Therefore, just one-time decomposition for fMRI data analysis is not usually reliable. Under this circumstance, several methods about repeated decompositions with ICA (RDICA) were proposed to reveal the stability of ICA decomposition. Although utilizing RDICA has achieved satisfying results in validating the performance of ICA decomposition, RDICA cost much computing time. To mitigate the problem, in this paper, we propose a method, named ATGP-ICA, to do the fMRI data analysis. This method generates fixed initial values with automatic target generation process (ATGP) instead of being produced randomly. We performed experimental tests on both hybrid data and fMRI data to indicate the effectiveness of the new method and made a performance comparison of the traditional one-time decomposition with ICA (ODICA), RDICA and ATGP-ICA. The proposed method demonstrated that it not only could eliminate the randomness of ICA decomposition, but also could save much computing time compared to RDICA. Furthermore, the ROC (Receiver Operating Characteristic) power analysis also denoted the better signal reconstruction performance of ATGP-ICA than that of RDICA. Copyright © 2013 Elsevier Inc. All rights reserved.
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
2014-10-01
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. 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. 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). 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. 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 current choices are limited to condoms and vasectomy. Copyright © 2014 Elsevier Inc. All rights reserved.
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 current choices are limited to condoms and vasectomy. PMID:24981149
Online Peer-to-Peer Support for Young People With Mental Health Problems: A Systematic Review.
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 studies, peer-to-peer support was not found to be effective. This systematic review identified an overall lack of high-quality studies examining online peer-to-peer support for young people. Given that peer support is frequently used as an adjunct to Internet interventions for a variety of mental health conditions, there is an urgent need to determine the effectiveness of peer support alone as an active intervention.
Solving satisfiability problems using a novel microarray-based DNA computer.
Lin, Che-Hsin; Cheng, Hsiao-Ping; Yang, Chang-Biau; Yang, Chia-Ning
2007-01-01
An algorithm based on a modified sticker model accompanied with an advanced MEMS-based microarray technology is demonstrated to solve SAT problem, which has long served as a benchmark in DNA computing. Unlike conventional DNA computing algorithms needing an initial data pool to cover correct and incorrect answers and further executing a series of separation procedures to destroy the unwanted ones, we built solutions in parts to satisfy one clause in one step, and eventually solve the entire Boolean formula through steps. No time-consuming sample preparation procedures and delicate sample applying equipment were required for the computing process. Moreover, experimental results show the bound DNA sequences can sustain the chemical solutions during computing processes such that the proposed method shall be useful in dealing with large-scale problems.
Elkordy, Sherif A; Fayed, Mona M Salah; Abouelezz, Amr M; Attia, Khaled H
2015-11-01
The objective of this 2-arm parallel randomized controlled trial was to evaluate patient acceptance of the mini-implant anchored Forsus Fatigue Resistant Device (FFRD) (3M Unitek, Monrovia, Calif). The study included 32 skeletal Class II girls. The eligibility criteria included a deficient mandible, a horizontal or neutral growth pattern, an increased overjet, and a full set of erupted permanent teeth. After the leveling and alignment stage, FFRDs and mini-implants were inserted; they were removed after the teeth reached an edge-to-edge incisor relationship. The patients were afterward asked to fill out assessment questionnaires regarding their experience with the FFRD. The primary outcome of this study was to assess patient acceptance of the appliance and satisfaction with the results. The secondary outcomes were interference with functional activities, noticeability by others, pain, swelling, gum problems caused by the appliance, and appliance breakage. Computer random sequence generation was done using block sizes of 6 and 4. Allocation concealment was achieved with sequentially numbered opaque sealed envelopes. Blinding of the clinicians and the patients to the intervention was impossible, but it was done for the outcome assessment and the statistician. The 32 patients were randomly allocated in a 1:1 ratio into 2 groups: 16 patients (mean age, 13.25 ± 1.12 years) received the FFRD alone (FFRD group), and 16 patients (mean age, 13.07 ± 1.41 years) had mini-implants in conjunction with FFRDs (FMI group). No statistically significant differences were reported between the 2 groups regarding ease of appliance insertion, noticeability by others, pain, swelling, effects on eating and speech, and gum bleeding; 100% and 87.5% were satisfied with the results in the FFRD and FMI groups, respectively, with a ridit value of 0.57 (95% confidence interval, 0.43-0.71; P = 0.36). No serious harm was observed other than swelling of the cheeks, which occurred in 4 patients. There were no significant differences between the patients' acceptance of the FFRD and the mini-implant anchored FFRD. They were highly satisfied with the results. Neither group reported significant functional limitations. This trial was not registered. The protocol was not published before trial commencement. The study was self-funded by the authors. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
Quantum random number generation for loophole-free Bell tests
NASA Astrophysics Data System (ADS)
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.
Doctor-office collaborative care for pediatric behavioral problems: a preliminary clinical trial.
Kolko, David J; Campo, John V; Kilbourne, Amy M; Kelleher, Kelly
2012-03-01
To evaluate the feasibility and clinical benefits of an integrated mental health intervention (doctor-office collaborative care [DOCC]) vs enhanced usual care (EUC) for children with behavioral problems. Cases were assigned to DOCC and EUC using a 2:1 randomization schedule that resulted in 55 DOCC and 23 EUC cases. Preassessment was conducted in 4 pediatric primary care practices. Postassessment was conducted in the pediatric or research office. Doctor-office collaborative care was provided in the practice; EUC was initiated in the office but involved a facilitated referral to a local mental health specialist. Of 125 referrals (age range, 5-12 years), 78 children participated. Children and their parents were assigned to receive DOCC or EUC. Preassessment diagnostic status was evaluated using the Schedule for Affective Disorders and Schizophrenia for School-aged Children. Preassessment and 6-month postassessment ratings of behavioral and emotional problems were collected from parents using the Vanderbilt Attention-Deficit/Hyperactivity Disorder Diagnostic Parent Rating Scale, as well as individualized goal achievement ratings forms. At discharge, care managers and a diagnostic evaluator completed the Clinical Global Impression Scale, and pediatricians and parents completed satisfaction and study feedback measures. Group comparisons found significant improvements for DOCC over EUC in service use and completion, behavioral and emotional problems, individualized behavioral goals, and overall clinical response. Pediatricians and parents were highly satisfied with DOCC. The feasibility and clinical benefits of DOCC for behavioral problems support the integration of collaborative mental health services for common mental disorders in primary care.
Consensus properties and their large-scale applications for the gene duplication problem.
Moon, Jucheol; Lin, Harris T; Eulenstein, Oliver
2016-06-01
Solving the gene duplication problem is a classical approach for species tree inference from gene trees that are confounded by gene duplications. This problem takes a collection of gene trees and seeks a species tree that implies the minimum number of gene duplications. Wilkinson et al. posed the conjecture that the gene duplication problem satisfies the desirable Pareto property for clusters. That is, for every instance of the problem, all clusters that are commonly present in the input gene trees of this instance, called strict consensus, will also be found in every solution to this instance. We prove that this conjecture does not generally hold. Despite this negative result we show that the gene duplication problem satisfies a weaker version of the Pareto property where the strict consensus is found in at least one solution (rather than all solutions). This weaker property contributes to our design of an efficient scalable algorithm for the gene duplication problem. We demonstrate the performance of our algorithm in analyzing large-scale empirical datasets. Finally, we utilize the algorithm to evaluate the accuracy of standard heuristics for the gene duplication problem using simulated datasets.
Blume-Kohout, Robin; Gamble, John King; Nielsen, Erik; ...
2017-02-15
Quantum information processors promise fast algorithms for problems inaccessible to classical computers. But since qubits are noisy and error-prone, they will depend on fault-tolerant quantum error correction (FTQEC) to compute reliably. Quantum error correction can protect against general noise if—and only if—the error in each physical qubit operation is smaller than a certain threshold. The threshold for general errors is quantified by their diamond norm. Until now, qubits have been assessed primarily by randomized benchmarking, which reports a different error rate that is not sensitive to all errors, and cannot be compared directly to diamond norm thresholds. Finally, we usemore » gate set tomography to completely characterize operations on a trapped-Yb +-ion qubit and demonstrate with greater than 95% confidence that they satisfy a rigorous threshold for FTQEC (diamond norm ≤6.7 × 10 -4).« less
Random medium model for cusping of plane waves.
Li, Jia; Korotkova, Olga
2017-09-01
We introduce a model for a three-dimensional (3D) Schell-type stationary medium whose degree of potential's correlation satisfies the Fractional Multi-Gaussian (FMG) function. Compared with the scattered profile produced by the Gaussian Schell-model (GSM) medium, the Fractional Multi-Gaussian Schell-model (FMGSM) medium gives rise to a sharp concave intensity apex in the scattered field. This implies that the FMGSM medium also accounts for a larger than Gaussian's power in the bucket (PIB) in the forward scattering direction, hence being a better candidate than the GSM medium for generating highly-focused (cusp-like) scattered profiles in the far zone. Compared to other mathematical models for the medium's correlation function which can produce similar cusped scattered profiles the FMG function offers unprecedented tractability being the weighted superposition of Gaussian functions. Our results provide useful applications to energy counter problems and particle manipulation by weakly scattered fields.
Variational bounds on the temperature distribution
NASA Astrophysics Data System (ADS)
Kalikstein, Kalman; Spruch, Larry; Baider, Alberto
1984-02-01
Upper and lower stationary or variational bounds are obtained for functions which satisfy parabolic linear differential equations. (The error in the bound, that is, the difference between the bound on the function and the function itself, is of second order in the error in the input function, and the error is of known sign.) The method is applicable to a range of functions associated with equalization processes, including heat conduction, mass diffusion, electric conduction, fluid friction, the slowing down of neutrons, and certain limiting forms of the random walk problem, under conditions which are not unduly restrictive: in heat conduction, for example, we do not allow the thermal coefficients or the boundary conditions to depend upon the temperature, but the thermal coefficients can be functions of space and time and the geometry is unrestricted. The variational bounds follow from a maximum principle obeyed by the solutions of these equations.
Jannink, Michiel J A; Erren-Wolters, C Victorien; de Kort, Alexander C; van der Kooij, Herman
2008-12-01
This paper describes an electric scooter simulation program and a first evaluation study in which we explored if it is possible to train the driving skills of future users of electric mobility scooters by means of an electric scooter simulation program in addition to conventional electric scooter training. Within this explorative study,10 stroke survivors were randomly assigned to either the control (n=5) or the electric scooter simulation intervention group (n=5). Participants were assessed twice on the functional evaluating rating scale. During the followup measurement, subjective experiences regarding both forms of electric scooter training were elicited by a questionnaire. After a training period of 5 weeks, both groups improved on the Functional Evaluation Rating Scale. It can be concluded that the patients with stroke were satisfied with the electric scooter simulation training.
Blume-Kohout, Robin; Gamble, John King; Nielsen, Erik; Rudinger, Kenneth; Mizrahi, Jonathan; Fortier, Kevin; Maunz, Peter
2017-01-01
Quantum information processors promise fast algorithms for problems inaccessible to classical computers. But since qubits are noisy and error-prone, they will depend on fault-tolerant quantum error correction (FTQEC) to compute reliably. Quantum error correction can protect against general noise if—and only if—the error in each physical qubit operation is smaller than a certain threshold. The threshold for general errors is quantified by their diamond norm. Until now, qubits have been assessed primarily by randomized benchmarking, which reports a different error rate that is not sensitive to all errors, and cannot be compared directly to diamond norm thresholds. Here we use gate set tomography to completely characterize operations on a trapped-Yb+-ion qubit and demonstrate with greater than 95% confidence that they satisfy a rigorous threshold for FTQEC (diamond norm ≤6.7 × 10−4). PMID:28198466
DOE Office of Scientific and Technical Information (OSTI.GOV)
Blume-Kohout, Robin; Gamble, John King; Nielsen, Erik
Quantum information processors promise fast algorithms for problems inaccessible to classical computers. But since qubits are noisy and error-prone, they will depend on fault-tolerant quantum error correction (FTQEC) to compute reliably. Quantum error correction can protect against general noise if—and only if—the error in each physical qubit operation is smaller than a certain threshold. The threshold for general errors is quantified by their diamond norm. Until now, qubits have been assessed primarily by randomized benchmarking, which reports a different error rate that is not sensitive to all errors, and cannot be compared directly to diamond norm thresholds. Finally, we usemore » gate set tomography to completely characterize operations on a trapped-Yb +-ion qubit and demonstrate with greater than 95% confidence that they satisfy a rigorous threshold for FTQEC (diamond norm ≤6.7 × 10 -4).« less
Energy levels of one-dimensional systems satisfying the minimal length uncertainty relation
DOE Office of Scientific and Technical Information (OSTI.GOV)
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-ordermore » 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.« less
Impact of Job Satisfaction on Greek Nurses' Health-Related Quality of Life
Ioannou, Panagiotis; Katsikavali, Vassiliki; Galanis, Petros; Velonakis, Emmanuel; Papadatou, Danai; Sourtzi, Panayota
2015-01-01
Background Employee job satisfaction and its relationship with health and quality of life has been an issue of major concern over the past decades. Nurses experience difficult working conditions that affect their job satisfaction, health, and quality of life. Methods A cross-sectional study was undertaken in three general hospitals and their respective health centers. Stratified random sampling by level of education was used, and 508 nurses and nursing assistants were included. A self-administered anonymous questionnaire, which included the Measure of Job Satisfaction, the 36-item Short Form Health Survey, as well as demographic details, education, and work conditions data, was used. Results Greek nurses were found to be dissatisfied with their job according to the total score of the job satisfaction scale, although personal satisfaction and satisfaction with support had had higher scores. Their general health was reported as average, because of physical and mental health problems, low vitality, low energy, and increased physical pain. Multivariate linear regression analysis revealed that males and those wishing to stay in the job had higher physical and mental health. Increased job satisfaction was related to increased physical and mental health. Conclusion Although Greek nurses are not satisfied with their work, those with high levels of job satisfaction had better health-related quality of life. The findings suggest that improvement of the work environment would contribute to a healthier and more satisfied nursing workforce. PMID:26929845
Impact of Job Satisfaction on Greek Nurses' Health-Related Quality of Life.
Ioannou, Panagiotis; Katsikavali, Vassiliki; Galanis, Petros; Velonakis, Emmanuel; Papadatou, Danai; Sourtzi, Panayota
2015-12-01
Employee job satisfaction and its relationship with health and quality of life has been an issue of major concern over the past decades. Nurses experience difficult working conditions that affect their job satisfaction, health, and quality of life. A cross-sectional study was undertaken in three general hospitals and their respective health centers. Stratified random sampling by level of education was used, and 508 nurses and nursing assistants were included. A self-administered anonymous questionnaire, which included the Measure of Job Satisfaction, the 36-item Short Form Health Survey, as well as demographic details, education, and work conditions data, was used. Greek nurses were found to be dissatisfied with their job according to the total score of the job satisfaction scale, although personal satisfaction and satisfaction with support had had higher scores. Their general health was reported as average, because of physical and mental health problems, low vitality, low energy, and increased physical pain. Multivariate linear regression analysis revealed that males and those wishing to stay in the job had higher physical and mental health. Increased job satisfaction was related to increased physical and mental health. Although Greek nurses are not satisfied with their work, those with high levels of job satisfaction had better health-related quality of life. The findings suggest that improvement of the work environment would contribute to a healthier and more satisfied nursing workforce.
Empirical Analysis and Refinement of Expert System Knowledge Bases
1988-08-31
refinement. Both a simulated case generation program, and a random rule basher were developed to enhance rule refinement experimentation. *Substantial...the second fiscal year 88 objective was fully met. Rule Refinement System Simulated Rule Basher Case Generator Stored Cases Expert System Knowledge...generated until the rule is satisfied. Cases may be randomly generated for a given rule or hypothesis. Rule Basher Given that one has a correct
McCarthy, Gerard; Maughan, Barbara
2010-09-01
This study investigated links between internal working models of attachment and the quality of adult love relationships in a high risk sample of women (n = 34), all of whom reported negative parenting in childhood. Half of the sample was identified as having a history of satisfying adult love relationships, while the remainder had experienced ongoing adult relationship problems. Measures of internal working models of attachment were made using the Adult Attachment Interview (AAI). A strong association was found between attachment classifications and the quality of adult love relationships. In addition, women with satisfying love relationships demonstrated significantly higher coherence of mind ratings than those with poor relationship histories. Insecure working models of attachment were associated with problems in adult love relationships. Although secure/autonomous attachment status was linked to optimal adult relationship outcomes, some women with a history of satisfying love relationships had insecure working models of attachment. These results suggest that the ways that adults process early experiences may influence later psychosocial functioning.
Can cannabis be considered a substitute medication for alcohol?
Subbaraman, Meenakshi Sabina
2014-01-01
Substituting cannabis for alcohol may reduce drinking and related problems among alcohol-dependent individuals. Some even recommend prescribing medical cannabis to individuals attempting to reduce drinking. The primary aim of this review is to assess whether cannabis satisfies the seven previously published criteria for substitute medications for alcohol [e.g. 'reduces alcohol-related harms'; 'is safer in overdose than alcohol'; 'should offer significant health economic benefits'; see Chick and Nutt ((2012) Substitution therapy for alcoholism: time for a reappraisal? J Psychopharmacol 26:205-12)]. Literature review. All criteria appear either satisfied or partially satisfied, though studies relying on medical cannabis patients may be limited by selection bias and/or retrospective designs. Individual-level factors, such as severity of alcohol problems, may also moderate substitution. There is no clear pattern of outcomes related to cannabis substitution. Most importantly, the recommendation to prescribe alcohol-dependent individuals cannabis to help reduce drinking is premature. Future studies should use longitudinal data to better understand the consequences of cannabis substitution.
Satisfied or Not Satisfied: Pain Experiences of Patients with Sickle Cell Disease
EZENWA, Miriam O.; MOLOKIE, Robert E.; WANG, Zaijie Jim; SUAREZ, Marie L.; YAO, Yingwei
2015-01-01
Aims To examine the relationship between pain and satisfaction in patients with sickle cell disease. Background Frequency and severity of unrelieved sickle cell pain are positively associated with mortality. Yet, information is scarce on whether sickle cell patients are satisfied with their pain level. Design A cross-sectional, correlational analysis of baseline data from a randomized clinical trial. Methods A randomized sample of adult outpatients was recruited between February 2007 - March 2011. Patients completed the PAINReportIt®, containing measures of pain, satisfaction and socio-demographics. We analyzed data using Kendall rank correlations, analysis of variance, Tukey-Kramer post hoc tests, Fisher’s tests and proportional odds logistic regression. Results There were significant correlations between pain outcomes (average pain intensity and composite pain index) and satisfaction with pain level, but average pain intensity more strongly discriminated groups based on satisfaction with pain level. Among pain variables bivariately associated with patient satisfaction with pain level (optimal pain goal, time with tolerable pain and pain expectation), only pain expectation maintained its significant relationship to satisfaction with pain level when average pain intensity was controlled. A smaller percentage of our sickle cell patients reported moderate to severe pain intensity (28%) or high composite pain index (39%) while reporting being satisfied with pain their level than reported in earlier studies using different measures and populations (70–94%). Conclusion Satisfaction with pain level was an unambiguous measure of patient satisfaction and a promising indicator of pain that did not show the paradoxical relationship between satisfaction and pain seen with past measures. PMID:25916256
2011-01-01
Background The government of Pakistan introduced devolution in 2001. Responsibility for delivery of most health services passed from provincial to district governments. Two national surveys examined public opinions, use, and experience of health services in 2001 and 2004, to assess the impact of devolution on these services from the point of view of the public. Methods A stratified random cluster sample drawn in 2001 and revisited in 2004 included households in all districts. Field teams administered a questionnaire covering views about available health services, use of government and private health services, and experience and satisfaction with the service. Focus groups in each community discussed reasons behind the findings, and district nazims (elected mayors) and administrators commented about implementation of devolution. Multivariate analysis, with an adjustment for clustering, examined changes over time, and associations with use and satisfaction with services in 2004. Results Few of 57,321 households interviewed in 2002 were satisfied with available government health services (23%), with a similar satisfaction (27%) among 53,960 households in 2004. Less households used government health services in 2004 (24%) than in 2002 (29%); the decrease was significant in the most populous province. In 2004, households were more likely to use government services if they were satisfied with the services, poorer, or less educated. The majority of users of government health services were satisfied; the increase from 63% to 67% between 2002 and 2004 was significant in two provinces. Satisfaction in 2004 was higher among users of private services (87%) or private unqualified practitioners (78%). Users of government services who received all medicines from the facility or who were given an explanation of their condition were more likely to be satisfied. Focus groups explained that people avoid government health services particularly because of bad treatment from staff, and unavailable or poor quality medicines. District nazims and administrators cited problems with implementation of devolution, especially with transfer of funds. Conclusions Under devolution, the public did not experience improved government health services, but devolution was not fully implemented as intended. An ongoing social audit process could provide a basis for local and national accountability of health services. PMID:22375682
Stahl, James E; Dixon, Ronald F
2010-01-01
We examined videoconferencing in comparison with face-to-face office visits in primary care. Four physicians took part in the study and 175 patients were recruited from a general medical practice. Patients were interviewed and examined in both face-to-face and virtual settings, the order being randomized. Patients and clinicians were surveyed by questionnaire after each visit. Physicians were very satisfied with videoconferencing but preferred face-to-face overall (P < 0.0001). For videoconferencing, the physical examination and the ability to order appropriate laboratory tests were the least satisfying elements of the encounter. Patients were also very satisfied with videoconferencing but overall preferred face-to-face (P < 0.0001). This difference was significant for gastrointestinal, musculoskeletal and respiratory complaints. However, in terms of willingness to pay (WTP) for videoconferencing access, patients with musculoskeletal and respiratory complaints were the most willing. Age and gender did not significantly predict WTP. The technical quality of the videoconference had a significant effect on satisfaction with the clinical encounter but did not correlate with the patients' WTP for videoconferencing. Travel costs up to $40 and travel times up to 4 hours did not influence the WTP of patients. For non-rural, relatively mobile patients, videoconferencing appears suitable for short visits for relatively simple complaints.
Weighted SGD for ℓ p Regression with Randomized Preconditioning.
Yang, Jiyan; Chow, Yin-Lam; Ré, Christopher; Mahoney, Michael W
2016-01-01
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., ℓ 2 and ℓ 1 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 ℓ p regression problem as a stochastic optimization problem, we connect pwSGD to several existing ℓ p 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 ℓ 1 regression with size n by d , pwSGD returns an approximate solution with ε relative error in the objective value in (log n ·nnz( A )+poly( d )/ ε 2 ) 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 ℓ 2 regression, pwSGD returns an approximate solution with ε relative error in the objective value and the solution vector measured in prediction norm in (log n ·nnz( A )+poly( d ) log(1/ ε )/ ε ) time. We show that for unconstrained ℓ 2 regression, this complexity is comparable to that of RLA and is asymptotically better over several state-of-the-art solvers in the regime where the desired accuracy ε , high dimension n and low dimension d satisfy d ≥ 1/ ε and n ≥ d 2 / ε . We also provide lower bounds on the coreset complexity for more general regression problems, indicating that still new ideas will be needed to extend similar RLA preconditioning ideas to weighted SGD algorithms for more general regression problems. Finally, the effectiveness of such algorithms is illustrated numerically on both synthetic and real datasets, and the results are consistent with our theoretical findings and demonstrate that pwSGD converges to a medium-precision solution, e.g., ε = 10 -3 , more quickly.
Systems Models for Transportation Problems : Volume 2. An Introduction to Urban Center Modeling.
DOT National Transportation Integrated Search
1976-03-01
Our thermodynamic theory considers the problem of attempting to formalize in a modeling sense what might be done in an urban economy, wherein transportation planning and other institutionalized requirements of the domain are also to be satisfied, and...
Symbolic programming language in molecular multicenter integral problem
NASA Astrophysics Data System (ADS)
Safouhi, Hassan; Bouferguene, Ahmed
It is well known that in any ab initio molecular orbital (MO) calculation, the major task involves the computation of molecular integrals, among which the computation of three-center nuclear attraction and Coulomb integrals is the most frequently encountered. As the molecular system becomes larger, computation of these integrals becomes one of the most laborious and time-consuming steps in molecular systems calculation. Improvement of the computational methods of molecular integrals would be indispensable to further development in computational studies of large molecular systems. To develop fast and accurate algorithms for the numerical evaluation of these integrals over B functions, we used nonlinear transformations for improving convergence of highly oscillatory integrals. These methods form the basis of new methods for solving various problems that were unsolvable otherwise and have many applications as well. To apply these nonlinear transformations, the integrands should satisfy linear differential equations with coefficients having asymptotic power series in the sense of Poincaré, which in their turn should satisfy some limit conditions. These differential equations are very difficult to obtain explicitly. In the case of molecular integrals, we used a symbolic programming language (MAPLE) to demonstrate that all the conditions required to apply these nonlinear transformation methods are satisfied. Differential equations are obtained explicitly, allowing us to demonstrate that the limit conditions are also satisfied.
An Analysis of Problems in College Students' Participation in the Western China Program
ERIC Educational Resources Information Center
Yumei, Yi
2008-01-01
Since its initiation in 2003, the College Student Western China Program has had several satisfying achievements. At the same time, however, problems exist in the project. This article gives a brief analysis of problems encountered in the project from the aspects of publicity and campaign work, plans and schedules, student participation, voluntary…
A Unified Approach to Optimization
2014-10-02
employee scheduling, ad placement, latin squares, disjunctions of linear systems, temporal modeling with interval variables, and traveling salesman problems ...integrating technologies. A key to integrated modeling is to formulate a problem with high-levelmetaconstraints, which are inspired by the “global... problem substructure to the solver. This contrasts with the atomistic modeling style of mixed integer programming (MIP) and satisfiability (SAT) solvers
Dynamic Restructuring Of Problems In Artificial Intelligence
NASA Technical Reports Server (NTRS)
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.
[Factors determining patient satisfaction with the pre-anaesthesia consultation].
Echevarria, M; Ramos, P; Caba, F; López, J; Almeida, C; Cortes Gonzalez, C
2015-01-01
To analyse patient satisfaction with care provided in the pre-anaesthetic consultation and its determining factors. An anonymous questionnaire was randomly distributed to patients attending a pre-anaesthesia clinic, which included 4 questions with 5 possible answers on a (very dissatisfied, dissatisfied, fairly satisfied, satisfied and very satisfied) categorical graduated scale related to punctuality, understanding of the information received, respectful treatment, and overall satisfaction. The fifth question was about the knowledge or the name of the anaesthesiologist who attended them. A binary logistic regression model was used, which identified the predictors of satisfaction, calculated the odds ratios, and their respective 95% confidence intervals. A total of 4006 questionnaires were analysed, in which 99.2% (3966) of users rated as satisfied/very satisfied the question about the respectful treatment, 98.4% (3937) of the information received and understanding, 77.4% (3096) punctuality in attending, and 97, 6% (3909) overall satisfaction. Almost three-quarters (71%, 2844) did not know the name of the anaesthesiologist. Regression analysis associated the more satisfied with their treatment (OR 17.44; P<.0005) and the information received (OR 14.94, P<.0005), while punctuality (OR 5 40; P<.0005) was the factor that contributed less to the result. In our population satisfaction in pre-anaesthesia consultation is due mainly to the communication skills of the anaesthesiologist. Copyright © 2014 SECA. Published by Elsevier Espana. All rights reserved.
On the decentralized control of large-scale systems. Ph.D. Thesis
NASA Technical Reports Server (NTRS)
Chong, C.
1973-01-01
The decentralized control of stochastic large scale systems was considered. Particular emphasis was given to control strategies which utilize decentralized information and can be computed in a decentralized manner. The deterministic constrained optimization problem is generalized to the stochastic case when each decision variable depends on different information and the constraint is only required to be satisfied on the average. For problems with a particular structure, a hierarchical decomposition is obtained. For the stochastic control of dynamic systems with different information sets, a new kind of optimality is proposed which exploits the coupled nature of the dynamic system. The subsystems are assumed to be uncoupled and then certain constraints are required to be satisfied, either in a off-line or on-line fashion. For off-line coordination, a hierarchical approach of solving the problem is obtained. The lower level problems are all uncoupled. For on-line coordination, distinction is made between open loop feedback optimal coordination and closed loop optimal coordination.
[Problem-solving strategies and marital satisfaction].
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.
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.
Weighted SGD for ℓp Regression with Randomized Preconditioning*
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 prediction norm in 𝒪(log n·nnz(A)+poly(d) log(1/ε)/ε) time. We show that for unconstrained ℓ2 regression, this complexity is comparable to that of RLA and is asymptotically better over several state-of-the-art solvers in the regime where the desired accuracy ε, high dimension n and low dimension d satisfy d ≥ 1/ε and n ≥ d2/ε. We also provide lower bounds on the coreset complexity for more general regression problems, indicating that still new ideas will be needed to extend similar RLA preconditioning ideas to weighted SGD algorithms for more general regression problems. Finally, the effectiveness of such algorithms is illustrated numerically on both synthetic and real datasets, and the results are consistent with our theoretical findings and demonstrate that pwSGD converges to a medium-precision solution, e.g., ε = 10−3, more quickly. PMID:29782626
Entropy production rate as a criterion for inconsistency in decision theory
NASA Astrophysics Data System (ADS)
Dixit, Purushottam D.
2018-05-01
Individual and group decisions are complex, often involving choosing an apt alternative from a multitude of options. Evaluating pairwise comparisons breaks down such complex decision problems into tractable ones. Pairwise comparison matrices (PCMs) are regularly used to solve multiple-criteria decision-making problems, for example, using Saaty’s analytic hierarchy process (AHP) framework. However, there are two significant drawbacks of using PCMs. First, humans evaluate PCMs in an inconsistent manner. Second, not all entries of a large PCM can be reliably filled by human decision makers. We address these two issues by first establishing a novel connection between PCMs and time-irreversible Markov processes. Specifically, we show that every PCM induces a family of dissipative maximum path entropy random walks (MERW) over the set of alternatives. We show that only ‘consistent’ PCMs correspond to detailed balanced MERWs. We identify the non-equilibrium entropy production in the induced MERWs as a metric of inconsistency of the underlying PCMs. Notably, the entropy production satisfies all of the recently laid out criteria for reasonable consistency indices. We also propose an approach to use incompletely filled PCMs in AHP. Potential future avenues are discussed as well.
Does adding an emotion component enhance the Triple P-Positive Parenting Program?
Salmon, Karen; Dittman, Cassandra; Sanders, Matthew; Burson, Rebecca; Hammington, Josie
2014-04-01
This pilot study aimed to compare the efficacy of a regular offering of the group-delivered Triple P-Positive Parenting Program for child behavior problems with an enhanced version tailored to promote child emotion competence. Families of children between ages 3 and 6 years displaying early-onset conduct problems were randomly assigned to Group Triple P (GTP; final n = 18) or Emotion Enhanced Triple P (EETP; final n = 18), in which parents were encouraged to incorporate emotion labels and causes and to coach emotion competence during discussions of everyday emotional experiences with their child. Compared with parents who received GTP, parents who received EETP increased their discussion of emotion labels and emotion causes in conversations with their child at postintervention, but this advantage was lost by the 4-month follow-up. Parents in the EETP condition also used more emotion coaching postintervention and at follow-up. There were no differences at postintervention or follow-up in children's emotion knowledge skills. Postintervention improvement in disruptive child behavior was greater for GTP, but the groups converged at follow-up. Parents were similarly satisfied with both interventions. Overall, EETP showed little advantage over regular GTP delivery. PsycINFO Database Record (c) 2014 APA, all rights reserved.
A predictive machine learning approach for microstructure optimization and materials design
NASA Astrophysics Data System (ADS)
Liu, Ruoqian; Kumar, Abhishek; Chen, Zhengzhang; Agrawal, Ankit; Sundararaghavan, Veera; Choudhary, Alok
2015-06-01
This paper addresses an important materials engineering question: How can one identify the complete space (or as much of it as possible) of microstructures that are theoretically predicted to yield the desired combination of properties demanded by a selected application? We present a problem involving design of magnetoelastic Fe-Ga alloy microstructure for enhanced elastic, plastic and magnetostrictive properties. While theoretical models for computing properties given the microstructure are known for this alloy, inversion of these relationships to obtain microstructures that lead to desired properties is challenging, primarily due to the high dimensionality of microstructure space, multi-objective design requirement and non-uniqueness of solutions. These challenges render traditional search-based optimization methods incompetent in terms of both searching efficiency and result optimality. In this paper, a route to address these challenges using a machine learning methodology is proposed. A systematic framework consisting of random data generation, feature selection and classification algorithms is developed. Experiments with five design problems that involve identification of microstructures that satisfy both linear and nonlinear property constraints show that our framework outperforms traditional optimization methods with the average running time reduced by as much as 80% and with optimality that would not be achieved otherwise.
Symbolically Modeling Concurrent MCAPI Executions
NASA Technical Reports Server (NTRS)
Fischer, Topher; Mercer, Eric; Rungta, Neha
2011-01-01
Improper use of Inter-Process Communication (IPC) within concurrent systems often creates data races which can lead to bugs that are challenging to discover. Techniques that use Satisfiability Modulo Theories (SMT) problems to symbolically model possible executions of concurrent software have recently been proposed for use in the formal verification of software. In this work we describe a new technique for modeling executions of concurrent software that use a message passing API called MCAPI. Our technique uses an execution trace to create an SMT problem that symbolically models all possible concurrent executions and follows the same sequence of conditional branch outcomes as the provided execution trace. We check if there exists a satisfying assignment to the SMT problem with respect to specific safety properties. If such an assignment exists, it provides the conditions that lead to the violation of the property. We show how our method models behaviors of MCAPI applications that are ignored in previously published techniques.
[Satisfaction about physical appearance and teeth. Results of a nationwide study].
Gresnigt-Bekker, C O V M; de Jongh, A; Vo, G; Lie, F; Oosterink-Wubbe, F M D; van Rood, Y
2008-07-01
In a study involving a group of 907 randomly selected Dutch individuals, satisfaction about one's physical appearance and satisfaction about the appearance of one's teeth were assessed. Furthermore, the relationship between body esteem and happiness was explored. Three quarters of the respondents were satisfied about their physical appearance, while 70% was satisfied about the appearance of their teeth. Women and people with a non-Dutch background were significantly less likely to be satisfied about their physical appearance than men and those with a Dutch background. Individuals 30 years old and younger were more likely to be satisfied about their teeth than those who were older. Almost two third of the respondents (64%) reported that the appearance of their teeth contributed positively to their happiness. Women and people with a non-Dutch background were most likely to indicate that the appearance of their teeth contributed to their happiness. Satisfaction about general physical appearance and appearance of the teeth were significantly associated with happiness. Prospective studies are needed to examine to what extent esthetically motivated dental treatments make people happy and enhance their general well-being.
NASA Astrophysics Data System (ADS)
Tang, Qiuhua; Li, Zixiang; Zhang, Liping; Floudas, C. A.; Cao, Xiaojun
2015-09-01
Due to the NP-hardness of the two-sided assembly line balancing (TALB) problem, multiple constraints existing in real applications are less studied, especially when one task is involved with several constraints. In this paper, an effective hybrid algorithm is proposed to address the TALB problem with multiple constraints (TALB-MC). Considering the discrete attribute of TALB-MC and the continuous attribute of the standard teaching-learning-based optimization (TLBO) algorithm, the random-keys method is hired in task permutation representation, for the purpose of bridging the gap between them. Subsequently, a special mechanism for handling multiple constraints is developed. In the mechanism, the directions constraint of each task is ensured by the direction check and adjustment. The zoning constraints and the synchronism constraints are satisfied by teasing out the hidden correlations among constraints. The positional constraint is allowed to be violated to some extent in decoding and punished in cost function. Finally, with the TLBO seeking for the global optimum, the variable neighborhood search (VNS) is further hybridized to extend the local search space. The experimental results show that the proposed hybrid algorithm outperforms the late acceptance hill-climbing algorithm (LAHC) for TALB-MC in most cases, especially for large-size problems with multiple constraints, and demonstrates well balance between the exploration and the exploitation. This research proposes an effective and efficient algorithm for solving TALB-MC problem by hybridizing the TLBO and VNS.
Comparison of genetic algorithm methods for fuel management optimization
DOE Office of Scientific and Technical Information (OSTI.GOV)
DeChaine, M.D.; Feltus, M.A.
1995-12-31
The CIGARO system was developed for genetic algorithm fuel management optimization. Tests are performed to find the best fuel location swap mutation operator probability and to compare genetic algorithm to a truly random search method. Tests showed the fuel swap probability should be between 0% and 10%, and a 50% definitely hampered the optimization. The genetic algorithm performed significantly better than the random search method, which did not even satisfy the peak normalized power constraint.
NASA Astrophysics Data System (ADS)
Bueno, Pablo; Cano, Pablo A.
2016-11-01
We drastically simplify the problem of linearizing a general higher-order theory of gravity. We reduce it to the evaluation of its Lagrangian on a particular Riemann tensor depending on two parameters, and the computation of two derivatives with respect to one of those parameters. We use our method to construct a D -dimensional cubic theory of gravity which satisfies the following properties: (1) it shares the spectrum of Einstein gravity, i.e., it only propagates a transverse and massless graviton on a maximally symmetric background; (2) it is defined in the same way in general dimensions; (3) it is neither trivial nor topological in four dimensions. Up to cubic order in curvature, the only previously known theories satisfying the first two requirements are the Lovelock ones. We show that, up to cubic order, there exists only one additional theory satisfying requirements (1) and (2). Interestingly, this theory is, along with Einstein gravity, the only one which also satisfies (3).
Using Stochastic Spiking Neural Networks on SpiNNaker to Solve Constraint Satisfaction Problems
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. PMID:29311791
Zickmund, Susan L; Burkitt, Kelly H; Gao, Shasha; Stone, Roslyn A; Jones, Audrey L; Hausmann, Leslie R M; Switzer, Galen E; Borrero, Sonya; Rodriguez, Keri L; Fine, Michael J
2018-03-01
Patient satisfaction is an important dimension of health care quality. The Veterans Health Administration (VA) is committed to providing high-quality care to an increasingly diverse patient population. To assess Veteran satisfaction with VA health care by race/ethnicity and gender. We conducted semi-structured telephone interviews with gender-specific stratified samples of black, white, and Hispanic Veterans from 25 predominantly minority-serving VA Medical Centers from June 2013 to January 2015. Satisfaction with health care was assessed in 16 domains using five-point Likert scales. We compared the proportions of Veterans who were very satisfied, somewhat satisfied, and less than satisfied (i.e., neither satisfied nor dissatisfied, somewhat dissatisfied, or very dissatisfied) in each domain, and used random-effects multinomial regression to estimate racial/ethnic differences by gender and gender differences by race/ethnicity. Interviews were completed for 1222 of the 1929 Veterans known to be eligible for the interview (63.3%), including 421 white, 389 black, and 396 Hispanic Veterans, 616 of whom were female. Veterans were less likely to be somewhat satisfied or less than satisfied versus very satisfied with care in each of the 16 domains. The highest satisfaction ratings were reported for costs, outpatient facilities, and pharmacy (74-76% very satisfied); the lowest ratings were reported for access, pain management, and mental health care (21-24% less than satisfied). None of the joint tests of racial/ethnic or gender differences in satisfaction (simultaneously comparing all three satisfaction levels) was statistically significant (p > 0.05). Pairwise comparisons of specific levels of satisfaction revealed racial/ethnic differences by gender in three domains and gender differences by race/ethnicity in five domains, with no consistent directionality across demographic subgroups. Our multisite interviews of a diverse sample of Veterans at primarily minority-serving sites showed generally high levels of health care satisfaction across 16 domains, with few quantitative differences by race/ethnicity or gender.
Controle du vol longitudinal d'un avion civil avec satisfaction de qualiies de manoeuvrabilite
NASA Astrophysics Data System (ADS)
Saussie, David Alexandre
2010-03-01
Fulfilling handling qualities still remains a challenging problem during flight control design. These criteria of different nature are derived from a wide experience based upon flight tests and data analysis, and they have to be considered if one expects a good behaviour of the aircraft. The goal of this thesis is to develop synthesis methods able to satisfy these criteria with fixed classical architectures imposed by the manufacturer or with a new flight control architecture. This is applied to the longitudinal flight model of a Bombardier Inc. business jet aircraft, namely the Challenger 604. A first step of our work consists in compiling the most commonly used handling qualities in order to compare them. A special attention is devoted to the dropback criterion for which theoretical analysis leads us to establish a practical formulation for synthesis purpose. Moreover, the comparison of the criteria through a reference model highlighted dominant criteria that, once satisfied, ensure that other ones are satisfied too. Consequently, we are able to consider the fulfillment of these criteria in the fixed control architecture framework. Guardian maps (Saydy et al., 1990) are then considered to handle the problem. Initially for robustness study, they are integrated in various algorithms for controller synthesis. Incidently, this fixed architecture problem is similar to the static output feedback stabilization problem and reduced-order controller synthesis. Algorithms performing stabilization and pole assignment in a specific region of the complex plane are then proposed. Afterwards, they are extended to handle the gain-scheduling problem. The controller is then scheduled through the entire flight envelope with respect to scheduling parameters. Thereafter, the fixed architecture is put aside while only conserving the same output signals. The main idea is to use Hinfinity synthesis to obtain an initial controller satisfying handling qualities thanks to reference model pairing and robust versus mass and center of gravity variations. Using robust modal control (Magni, 2002), we are able to reduce substantially the controller order and to structure it in order to come close to a classical architecture. An auto-scheduling method finally allows us to schedule the controller with respect to scheduling parameters. Two different paths are used to solve the same problem; each one exhibits its own advantages and disadvantages.
Physician assistants and nurse practitioners in the National Health Service Corps.
Pathman, Donald E; Konrad, Thomas R; Hooker, Roderick S
2014-12-01
This study describes the experiences of physician assistants (PAs) and nurse practitioners (NPs) in the National Health Service Corps' (NHSC) loan repayment program in 2010. In 2011, a stratified random sample of NHSC clinicians was surveyed. Data from the 148 PA and 137 NP respondents were analyzed (52.4% response rate). PAs were younger than NPs (mean age 31 versus 35 years), less often female (68% versus 91%), and more often carried educational debt over $100,000 (56% versus 24%). Both groups were serving in states familiar to them and within communities where they felt accepted. The groups were generally satisfied on most measures of work, with PAs more satisfied than NPs on some measures. The NHSC's PAs and NPs are well matched to communities and satisfied with their work. Maximizing their NHSC experiences and retention requires recognizing their differences in demographics, debt, and areas of job satisfaction.
Two proposed convergence criteria for Monte Carlo solutions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Forster, R.A.; Pederson, S.P.; Booth, T.E.
1992-01-01
The central limit theorem (CLT) can be applied to a Monte Carlo solution if two requirements are satisfied: (1) The random variable has a finite mean and a finite variance; and (2) the number N of independent observations grows large. When these two conditions are satisfied, a confidence interval (CI) based on the normal distribution with a specified coverage probability can be formed. The first requirement is generally satisfied by the knowledge of the Monte Carlo tally being used. The Monte Carlo practitioner has a limited number of marginal methods to assess the fulfillment of the second requirement, such asmore » statistical error reduction proportional to 1/[radical]N with error magnitude guidelines. Two proposed methods are discussed in this paper to assist in deciding if N is large enough: estimating the relative variance of the variance (VOV) and examining the empirical history score probability density function (pdf).« less
Can Cannabis be Considered a Substitute Medication for Alcohol?
Subbaraman, Meenakshi Sabina
2014-01-01
Aims: Substituting cannabis for alcohol may reduce drinking and related problems among alcohol-dependent individuals. Some even recommend prescribing medical cannabis to individuals attempting to reduce drinking. The primary aim of this review is to assess whether cannabis satisfies the seven previously published criteria for substitute medications for alcohol [e.g. ‘reduces alcohol-related harms’; ‘is safer in overdose than alcohol’; ‘should offer significant health economic benefits’; see Chick and Nutt ((2012) Substitution therapy for alcoholism: time for a reappraisal? J Psychopharmacol 26:205–12)]. Methods: Literature review. Results: All criteria appear either satisfied or partially satisfied, though studies relying on medical cannabis patients may be limited by selection bias and/or retrospective designs. Individual-level factors, such as severity of alcohol problems, may also moderate substitution. Conclusions: There is no clear pattern of outcomes related to cannabis substitution. Most importantly, the recommendation to prescribe alcohol-dependent individuals cannabis to help reduce drinking is premature. Future studies should use longitudinal data to better understand the consequences of cannabis substitution. PMID:24402247
Processing time tolerance-based ACO algorithm for solving job-shop scheduling problem
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
Kim, Yup; Cho, Minsoo; Yook, Soon-Hyung
2011-10-01
We study the effects of the underlying topologies on a single feature perturbation imposed to the Axelrod model of consensus formation. From the numerical simulations we show that there are successive updates which are similar to avalanches in many self-organized criticality systems when a perturbation is imposed. We find that the distribution of avalanche size satisfies the finite-size scaling (FSS) ansatz on two-dimensional lattices and random networks. However, on scale-free networks with the degree exponent γ≤3 we show that the avalanche size distribution does not satisfy the FSS ansatz. The results indicate that the disordered configurations on two-dimensional lattices or on random networks are still stable against the perturbation in the limit N (network size) →∞. However, on scale-free networks with γ≤3 the perturbation always drives the disordered phase into an ordered phase. The possible relationship between the properties of phase transition of the Axelrod model and the avalanche distribution is also discussed.
Delta-Complete Analysis for Bounded Reachability of Hybrid Systems
2014-07-16
framework makes bounded reachability of hybrid systems a much more mathematically tractable problem and show that our practical implementation can handle...step i in the hybrid trajectory to an appropriate discrete mode in H , and make sure that the flow, jump, inv, init conditions are satisfied...trajectories start with some initial state satisfying initq(x0) for some q. In each step, it follows flowq(xi,xti, t) and makes a continuous flow from xi to x t
Observers for Systems with Nonlinearities Satisfying an Incremental Quadratic Inequality
NASA Technical Reports Server (NTRS)
Acikmese, Ahmet Behcet; Corless, Martin
2004-01-01
We consider the problem of state estimation for nonlinear time-varying systems whose nonlinearities satisfy an incremental quadratic inequality. These observer results unifies earlier results in the literature; and extend it to some additional classes of nonlinearities. Observers are presented which guarantee that the state estimation error exponentially converges to zero. Observer design involves solving linear matrix inequalities for the observer gain matrices. Results are illustrated by application to a simple model of an underwater.
Optimally Stopped Optimization
NASA Astrophysics Data System (ADS)
Vinci, Walter; Lidar, Daniel A.
2016-11-01
We combine the fields of heuristic optimization and optimal stopping. We propose a strategy for benchmarking randomized optimization algorithms that minimizes the expected total cost for obtaining a good solution with an optimal number of calls to the solver. To do so, rather than letting the objective function alone define a cost to be minimized, we introduce a further cost-per-call of the algorithm. We show that this problem can be formulated using optimal stopping theory. The expected cost is a flexible figure of merit for benchmarking probabilistic solvers that can be computed when the optimal solution is not known and that avoids the biases and arbitrariness that affect other measures. The optimal stopping formulation of benchmarking directly leads to a real-time optimal-utilization strategy for probabilistic optimizers with practical impact. We apply our formulation to benchmark simulated annealing on a class of maximum-2-satisfiability (MAX2SAT) problems. We also compare the performance of a D-Wave 2X quantum annealer to the Hamze-Freitas-Selby (HFS) solver, a specialized classical heuristic algorithm designed for low-tree-width graphs. On a set of frustrated-loop instances with planted solutions defined on up to N =1098 variables, the D-Wave device is 2 orders of magnitude faster than the HFS solver, and, modulo known caveats related to suboptimal annealing times, exhibits identical scaling with problem size.
Patient satisfaction and efficacy of accent radiofrequency for facial skin wrinkle reduction
Jaffary, Fariba; Nilforoushzadeh, Mohammad Ali; Zarkoob, Hajar
2013-01-01
Background: Radiofrequency (RF) is a new technique to treat facial wrinkles. This study was designed to assess the efficacy of Accent RF in wrinkle reduction of different areas of the face. Materials and Methods: Patients with mild to severe facial wrinkles were treated with Accent using RF energies of 35-145 W. The average energy used in this study was 83.11 W. Patients received four subsequent weekly RF sessions. Wrinkle improvement was rated by two physicians comparing 6-month post treatment photographs with pretreatment photos. Moreover, patient satisfaction was assessed at 1 and 6 months after the last session of the treatment. Results: A total of 45 women participated in this study. In terms of patient satisfaction one month after the last treatment, 8.9% of the patients declared their dissatisfaction, 53.3% were somehow satisfied, 33.3% were satisfied, and 4.4% were very satisfied. At 6 months, patient satisfaction was as follows: 4.4% dissatisfied, 31.1% somehow satisfied, 46.7% satisfied, and 17.8% very satisfied. Patient satisfaction 6 months after the last treatment was significantly higher than 1 month post treatment (P = 0.006). At 6 months, patient satisfaction was not more than 75% in any treatment areas of the face. Conclusion: The results of this study suggest that Accent RF may be considered as a possible effective option for facial skin rejuvenation although its efficacy and safety needs to be evaluated further in randomized controlled trials. PMID:24523783
A hybrid-type quantum random number generator
NASA Astrophysics Data System (ADS)
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).
Quantum Entanglement in Neural Network States
NASA Astrophysics Data System (ADS)
Deng, Dong-Ling; Li, Xiaopeng; Das Sarma, S.
2017-04-01
Machine learning, one of today's most rapidly growing interdisciplinary fields, promises an unprecedented perspective for solving intricate quantum many-body problems. Understanding the physical aspects of the representative artificial neural-network states has recently become highly desirable in the applications of machine-learning techniques to quantum many-body physics. In this paper, we explore the data structures that encode the physical features in the network states by studying the quantum entanglement properties, with a focus on the restricted-Boltzmann-machine (RBM) architecture. We prove that the entanglement entropy of all short-range RBM states satisfies an area law for arbitrary dimensions and bipartition geometry. For long-range RBM states, we show by using an exact construction that such states could exhibit volume-law entanglement, implying a notable capability of RBM in representing quantum states with massive entanglement. Strikingly, the neural-network representation for these states is remarkably efficient, in the sense that the number of nonzero parameters scales only linearly with the system size. We further examine the entanglement properties of generic RBM states by randomly sampling the weight parameters of the RBM. We find that their averaged entanglement entropy obeys volume-law scaling, and the meantime strongly deviates from the Page entropy of the completely random pure states. We show that their entanglement spectrum has no universal part associated with random matrix theory and bears a Poisson-type level statistics. Using reinforcement learning, we demonstrate that RBM is capable of finding the ground state (with power-law entanglement) of a model Hamiltonian with a long-range interaction. In addition, we show, through a concrete example of the one-dimensional symmetry-protected topological cluster states, that the RBM representation may also be used as a tool to analytically compute the entanglement spectrum. Our results uncover the unparalleled power of artificial neural networks in representing quantum many-body states regardless of how much entanglement they possess, which paves a novel way to bridge computer-science-based machine-learning techniques to outstanding quantum condensed-matter physics problems.
NASA Astrophysics Data System (ADS)
Du, Shihong; Zhang, Fangli; Zhang, Xiuyuan
2015-07-01
While most existing studies have focused on extracting geometric information on buildings, only a few have concentrated on semantic information. The lack of semantic information cannot satisfy many demands on resolving environmental and social issues. This study presents an approach to semantically classify buildings into much finer categories than those of existing studies by learning random forest (RF) classifier from a large number of imbalanced samples with high-dimensional features. First, a two-level segmentation mechanism combining GIS and VHR image produces single image objects at a large scale and intra-object components at a small scale. Second, a semi-supervised method chooses a large number of unbiased samples by considering the spatial proximity and intra-cluster similarity of buildings. Third, two important improvements in RF classifier are made: a voting-distribution ranked rule for reducing the influences of imbalanced samples on classification accuracy and a feature importance measurement for evaluating each feature's contribution to the recognition of each category. Fourth, the semantic classification of urban buildings is practically conducted in Beijing city, and the results demonstrate that the proposed approach is effective and accurate. The seven categories used in the study are finer than those in existing work and more helpful to studying many environmental and social problems.
Valizadeh, Neda; Jalaly, Niloofar Y; Zarghampour, Manijeh; Barikbin, Behrooz; Haghighatkhah, Hamid Reza
2016-01-01
Submental fat accumulation and skin laxity is a frequent concern of cosmetic patients. The aim of this randomized prospective controlled clinical trial was to compare the efficacy and safety of laser-assisted lipolysis and liposuction in the submental rejuvenation. Thirty-six female adults were enrolled in this clinical trial and were categorized into two groups: group 1 underwent 980-nm diode laser with the power of 6-8 W and group 2 underwent traditional liposuction. Patients were evaluated with ultrasonography 2 weeks and 2 months after the procedures. Ultrasonographic evaluation reported the significant reduction of fat thickness in each group compared with the baseline (p value < 0.001). At the 2 weeks and 2 months follow-up visit, fat thickness reduction was significantly higher in the lipolysis group (p value < 0.05). Overall patients' satisfaction in lipolysis group was higher than liposuction with 11 (61%) of lipolysis patients being very satisfied in contrast to 10 (55.5%) of liposuction patients reporting "dissatisfied or neutral" results. Laser-assisted lipolysis using 980-nm diode is approved to be safe and effective for skin tightening and rejuvenation of the submental area and seems to be a better option than traditional techniques for treatment of this cosmetic problem.
Ultrametric properties of the attractor spaces for random iterated linear function systems
NASA Astrophysics Data System (ADS)
Buchovets, A. G.; Moskalev, P. V.
2018-03-01
We investigate attractors of random iterated linear function systems as independent spaces embedded in the ordinary Euclidean space. The introduction on the set of attractor points of a metric that satisfies the strengthened triangle inequality makes this space ultrametric. Then inherent in ultrametric spaces the properties of disconnectedness and hierarchical self-similarity make it possible to define an attractor as a fractal. We note that a rigorous proof of these properties in the case of an ordinary Euclidean space is very difficult.
Tamang, Anand; Shah, Iqbal H; Shrestha, Pragya; Warriner, I K; Wang, Duolao; Thapa, Kusum; My Huong, N T; Meirik, Olav
2017-12-16
Early first-trimester medical abortion (MA) service (≤ 63 days) has been provided by doctors and nurses under doctors' supervision since 2009 in Nepal. This paper assesses whether MA services provided by specifically trained and certified nurses and auxiliary nurse-midwives independently from doctors' supervision, is considered as satisfactory by women as those provided by doctors. The data come from a multi-center, randomized, controlled equivalence trial conducted between April 2009 and March 2010 in five district hospitals in Nepal. Women seeking MA were randomly assigned to doctors or nurses and auxiliary nurse-midwives(ANMs).Eligible women were administered 200 mg mifepristone orally followed by 800 μg misoprostol vaginally two days later by their assigned providers and followed up 10-14 days later. At the follow-up visit women's reported satisfaction with MA service they received was measured. Of 1295 women screened for eligibility, 535 were randomly assigned to a doctor and 542 to a nurse or ANM. Nineteen women were lost-to-follow up in the former group and 27 were lost-to-follow up or did not complete the acceptability interview in the latter group. This study is, therefore, based on516womenin the doctor's group and 515 women in the nurse or ANM group. All women in the nurse or ANM group reported being satisfied or highly satisfied by MA compared to 99% in the doctor's group. Satisfaction was similar regardless of the type of provider; 38% among nurse or ANM and 35% among the doctor group were "highly satisfied", and 62% and 64%, respectively, were "satisfied". Women's experiences such as 'less than expected amount or duration of bleeding following MA', 'shorter than expected duration of the abortion process', and 'able to manage symptoms', were found to be associated with women's higher satisfaction with MA. Counseling and information on the method, potential complications of MA and post-abortion contraception was nearly universal. No statistically significant differences were found in the level of satisfaction by age, parity, marital status, education or occupation of women. Women's satisfaction with MA service provided by trained nurses or auxiliary nurse-midwives was similar to that provided by doctors. The findings, therefore, provide support for extending safe and accessible medical abortion services by government-trained nurses and auxiliary nurse midwives to women seeking early first trimester pregnancy termination. The trial was retrospectively registered with ClinicalTrials.gov (identifier: NCT01186302 ). Registered August 20, 2010.
Robin problems with a general potential and a superlinear reaction
NASA Astrophysics Data System (ADS)
Papageorgiou, Nikolaos S.; Rădulescu, Vicenţiu D.; Repovš, Dušan D.
2017-09-01
We consider semilinear Robin problems driven by the negative Laplacian plus an indefinite potential and with a superlinear reaction term which need not satisfy the Ambrosetti-Rabinowitz condition. We prove existence and multiplicity theorems (producing also an infinity of smooth solutions) using variational tools, truncation and perturbation techniques and Morse theory (critical groups).
Teaching Geometry through Problem-Based Learning
ERIC Educational Resources Information Center
Schettino, Carmel
2011-01-01
About seven years ago, the mathematics teachers at the author's secondary school came to the conclusion that they were not satisfied with their rather traditional geometry textbook. The author had already begun using a problem-based approach to teaching geometry in her classes, a transition for her and her students that inspired her to write about…
Job Satisfaction, Job Reward Characteristics, and Employees' Problem Drinking Behaviors.
ERIC Educational Resources Information Center
Martin, Jack K.; Roman, Paul M.
1996-01-01
Data from the National Employee Survey revealed a complex interplay of job stress, rewards, and job satisfaction influencing employees' problem drinking behavior. Satisfied workers were significantly less likely to abuse alcohol. Support was found for the spillover model indicating that work has important effects on behavior in nonwork settings.…
Optimized Waterspace Management and Scheduling Using Mixed-Integer Linear Programming
2016-01-01
Complete [30]. Proposition 4.1 satisfies the first criterion. For the second criterion, we will use the Traveling Salesman Problem (TSP), which has been...A branch and cut algorithm for the symmetric generalized traveling salesman problem , Operations Research 45 (1997) 378–394. [33] J. Silberholz, B...Golden, The generalized traveling salesman problem : A new genetic algorithm ap- proach, Extended Horizons: Advances in Computing, Optimization, and
A global approach to kinematic path planning to robots with holonomic and nonholonomic constraints
NASA Technical Reports Server (NTRS)
Divelbiss, Adam; Seereeram, Sanjeev; Wen, John T.
1993-01-01
Robots in applications may be subject to holonomic or nonholonomic constraints. Examples of holonomic constraints include a manipulator constrained through the contact with the environment, e.g., inserting a part, turning a crank, etc., and multiple manipulators constrained through a common payload. Examples of nonholonomic constraints include no-slip constraints on mobile robot wheels, local normal rotation constraints for soft finger and rolling contacts in grasping, and conservation of angular momentum of in-orbit space robots. The above examples all involve equality constraints; in applications, there are usually additional inequality constraints such as robot joint limits, self collision and environment collision avoidance constraints, steering angle constraints in mobile robots, etc. The problem of finding a kinematically feasible path that satisfies a given set of holonomic and nonholonomic constraints, of both equality and inequality types is addressed. The path planning problem is first posed as a finite time nonlinear control problem. This problem is subsequently transformed to a static root finding problem in an augmented space which can then be iteratively solved. The algorithm has shown promising results in planning feasible paths for redundant arms satisfying Cartesian path following and goal endpoint specifications, and mobile vehicles with multiple trailers. In contrast to local approaches, this algorithm is less prone to problems such as singularities and local minima.
Analysis of a Bianchi-like equation satisfied by the Mars-Simon tensor
NASA Astrophysics Data System (ADS)
Beyer, Florian; Paetz, Tim-Torben
2018-02-01
The Mars-Simon tensor (MST), which, e.g., plays a crucial role to provide gauge invariant characterizations of the Kerr-NUT-(A)(dS) family, satisfies a Bianchi-like equation. In this paper, we analyze this equation in close analogy to the Bianchi equation, in particular it will be shown that the constraints are preserved supposing that a generalized Buchdahl condition holds. This permits the systematic construction of solutions to this equation in terms of a well-posed Cauchy problem. A particular emphasis lies on the asymptotic Cauchy problem, where data are prescribed on a space-like I (i.e., for ∧ > 0). In contrast to the Bianchi equation, the MST equation is of Fuchsian type at I , for which existence and uniqueness results are derived.
Job Satisfaction of High School Journalism Educators.
ERIC Educational Resources Information Center
Dvorak, Jack; Phillips, Kay D.
Four research questions are posed to explore the job satisfaction of high school journalism educators. A national random sample of 669 respondents shows that journalism educators are generally satisfied with their jobs--more so than teachers in other disciplines. Multiple regression analysis using Herzberg's motivation-hygiene theory as a…
Kim Halford, W; Pepping, Christopher A; Hilpert, Peter; Bodenmann, Guy; Wilson, Keithia L; Busby, Dean; Larson, Jeffry; Holman, Thomas
2015-05-01
Couple relationship education (RE) usually is conceived of as relationship enhancement for currently satisfied couples, with a goal of helping couples sustain satisfaction. However, RE also might be useful as a brief, accessible intervention for couples with low satisfaction. Two studies were conducted that tested whether couples with low relationship satisfaction show meaningful gains after RE. Study 1 was a three-condition randomized controlled trial in which 182 couples were randomly assigned to RELATE with Couple CARE (RCC), a flexible delivery education program for couples, or one of two control conditions. Couples with initially low satisfaction receiving RCC showed a moderate increase in relationship satisfaction (d=0.50) relative to the control. In contrast, couples initially high in satisfaction showed little change and there was no difference between RCC and the control conditions. Study 2 was an uncontrolled trial of the Couple Coping Enhancement Training (CCET) administered to 119 couples. Couples receiving CCET that had initially low satisfaction showed a moderate increase in satisfaction (g=.44), whereas initially highly satisfied couples showed no change. Brief relationship education can assist somewhat distressed couples to enhance satisfaction, and has potential as a cost-effective way of enhancing the reach of couple interventions. Copyright © 2015. Published by Elsevier Ltd.
The random fractional matching problem
NASA Astrophysics Data System (ADS)
Lucibello, Carlo; Malatesta, Enrico M.; Parisi, Giorgio; Sicuro, Gabriele
2018-05-01
We consider two formulations of the random-link fractional matching problem, a relaxed version of the more standard random-link (integer) matching problem. In one formulation, we allow each node to be linked to itself in the optimal matching configuration. In the other one, on the contrary, such a link is forbidden. Both problems have the same asymptotic average optimal cost of the random-link matching problem on the complete graph. Using a replica approach and previous results of Wästlund (2010 Acta Mathematica 204 91–150), we analytically derive the finite-size corrections to the asymptotic optimal cost. We compare our results with numerical simulations and we discuss the main differences between random-link fractional matching problems and the random-link matching problem.
Gavigan, P; Carr, A; McKeon, P
2000-10-01
A previous national study of public attitudes to depression indicated that only 17% spontaneously mentioned their general practitioner as someone who could help with depression, in contrast to 79% of respondents being willing to consult their G.P. in a similar U.K. survey. The present study undertook to examine the public perception of an urban sample to the treatment of depression in general practice and the factors associated with expressed unwillingness to consult. A random sample from the electoral register was drawn and 54 (89%) of 61 subjects selected were interviewed. While 85% of respondents were satisfied with their general practice care, only 24% to 52%, depending on the context and wording of the question, said that they would seek help from their general practitioner for depression. Factors associated with an expressed reluctance to consult were being male, dissatisfied with general practitioner care and believing that general practitioners were not qualified to treat depression.
Adamu, Aishatu L.; Galadanci, Najibah A.; Zubayr, Bashir; Odoh, Chisom N.; Aliyu, Muktar H.
2017-01-01
Background Multidrug resistant tuberculosis (MDR-TB), is an emerging public health problem in sub-Saharan Africa (SSA). This study aims to determine the trends in prevalence of MDR-TB among new TB cases in sub-Saharan Africa over two decades. Methods We searched electronic data bases and accessed all prevalence studies of MDR-TB within SSA between 2007 and 2017. We determined pooled prevalence estimates using random effects models and determined trends using meta-regression. Results Results: We identified 915 studies satisfying inclusion criteria. Cumulatively, studies reported on MDR-TB culture of 34,652 persons. The pooled prevalence of MDR-TB in new cases was 2.1% (95% CI; 1.7–2.5%). There was a non-significant decline in prevalence by 0.12% per year. Conclusion We found a low prevalence estimate of MDR-TB, and a slight temporal decline over the study period. There is a need for continuous MDR-TB surveillance among patients with TB. PMID:28945771
Information fusion methods based on physical laws.
Rao, Nageswara S V; Reister, David B; Barhen, Jacob
2005-01-01
We consider systems whose parameters satisfy certain easily computable physical laws. Each parameter is directly measured by a number of sensors, or estimated using measurements, or both. The measurement process may introduce both systematic and random errors which may then propagate into the estimates. Furthermore, the actual parameter values are not known since every parameter is measured or estimated, which makes the existing sample-based fusion methods inapplicable. We propose a fusion method for combining the measurements and estimators based on the least violation of physical laws that relate the parameters. Under fairly general smoothness and nonsmoothness conditions on the physical laws, we show the asymptotic convergence of our method and also derive distribution-free performance bounds based on finite samples. For suitable choices of the fuser classes, we show that for each parameter the fused estimate is probabilistically at least as good as its best measurement as well as best estimate. We illustrate the effectiveness of this method for a practical problem of fusing well-log data in methane hydrate exploration.
Random deflections of a string on an elastic foundation.
NASA Technical Reports Server (NTRS)
Sanders, J. L., Jr.
1972-01-01
The paper is concerned with the problem of a taut string on a random elastic foundation subjected to random loads. The boundary value problem is transformed into an initial value problem by the method of invariant imbedding. Fokker-Planck equations for the random initial value problem are formulated and solved in some special cases. The analysis leads to a complete characterization of the random deflection function.
NASA Technical Reports Server (NTRS)
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.
Patient satisfaction with service quality as a predictor of survival outcomes in breast cancer.
Gupta, Digant; Rodeghier, Mark; Lis, Christopher G
2014-01-01
Despite the recognized relevance of symptom burden in breast cancer, there has been limited exploration of whether an individual patient's assessment of the overall quality of care received might influence outcome. We therefore evaluated the relationship between patient-reported satisfaction with service quality and survival in breast cancer. A random sample of 1,521 breast cancer patients treated at Cancer Treatment Centers of America. A questionnaire which covered several dimensions of patient satisfaction was administered. Items were measured on a seven-point Likert scale ranging from "completely dissatisfied" to "completely satisfied". Univariate and multivariate Cox regression was used to evaluate the association between patient satisfaction and survival. Of 1,521 patients, 836 were newly diagnosed, and 685 had previously been treated. A number of 409, 611, 323, and 178 patients had stage I, II, III, and IV disease, respectively. A total of 1,106 (72.7 %) patients were completely satisfied with the overall service quality, while 415 (27.3 %) were not. On univariate analysis, completely satisfied patients had a significantly lower risk of mortality compared to those not completely satisfied (HR = 0.62; 95 % CI 0.50-0.76; p < 0.001). On multivariate analysis, completely satisfied patients demonstrated significantly lower mortality (HR = 0.71; 95 % CI 0.57-0.87; p = 0.001) compared to those not completely satisfied. Patient satisfaction with service quality was an independent predictor of survival in breast cancer. Further exploration of a possible meaningful relationship between patient satisfaction with the care they receive and outcomes in breast cancer is indicated.
Reflections on the surface energy imbalance problem
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-...
NASA Astrophysics Data System (ADS)
Yeung, Chi Ho
In this thesis, we study two interdisciplinary problems in the framework of statistical physics, which show the broad applicability of physics on problems with various origins. The first problem corresponds to an optimization problem in allocating resources on random regular networks. Frustrations arise from competition for resources. When the initial resources are uniform, different regimes with discrete fractions of satisfied nodes are observed, resembling the Devil's staircase. We apply the spin glass theory in analyses and demonstrate how functional recursions are converted to simple recursions of probabilities. Equilibrium properties such as the average energy and the fraction of free nodes are derived. When the initial resources are bimodally distributed, increases in the fraction of rich nodes induce a glassy transition, entering a glassy phase described by the existence of multiple metastable states, in which we employ the replica symmetry breaking ansatz for analysis. The second problem corresponds to the study of multi-agent systems modeling financial markets. Agents in the system trade among themselves, and self-organize to produce macroscopic trading behaviors resembling the real financial markets. These behaviors include the arbitraging activities, the setting up and the following of price trends. A phase diagram of these behaviors is obtained, as a function of the sensitivity of price and the market impact factor. We finally test the applicability of the models with real financial data including the Hang Seng Index, the Nasdaq Composite and the Dow Jones Industrial Average. A substantial fraction of agents gains faster than the inflation rate of the indices, suggesting the possibility of using multi-agent systems as a tool for real trading.
Patient Satisfaction With Care for Urgent Health Problems: A Survey of Family Practice Patients
Howard, Michelle; Goertzen, James; Hutchison, Brian; Kaczorowski, Janusz; Morris, Kelly
2007-01-01
PURPOSE Patient satisfaction is an important health care outcome. This study compared patients’ satisfaction with care received for an urgent health problem from their family physician, at an after-hours clinic in which their physician participated, at a walk-in clinic, at the emergency department, from telephone health advisory services, or from more than 1 of those services. METHODS We mailed a questionnaire to a random sample of patients from 36 family practices in Thunder Bay, Ontario. We elicited satisfaction with care for the most recent urgent health problem in the past 6 months on a 7-point scale (very dissatisfied to very satisfied). RESULTS The response rate was 62.3% (5,884 of 9,397). Of the 5,722 eligible patients 1,342 (23.4%) reported an urgent health problem, and data were available for both services used and satisfaction for 1,227 patients. After adjusting for sociodemographic characteristics and self-reported health status, satisfaction with care received for most recent urgent health problem was significantly higher among patients who visited or spoke to their family physician (mean 6.1; 95% confidence interval [CI], 5.8–6.4) compared with all other services (all P <.004, adjusted for multiple comparisons), with the exception of patients who used the after-hours clinic affiliated with their physician, whose satisfaction was not significantly different (mean 5.6; 95% CI, 5.2–6.0). CONCLUSIONS Satisfaction was highest for patients receiving care from their own family physician or their physician’s after-hours clinic. These results are important for new primary care models that emphasize continuity and after-hours availability of family physicians. PMID:17893383
Deep Space Network Scheduling Using Evolutionary Computational Methods
NASA Technical Reports Server (NTRS)
Guillaume, Alexandre; Lee, Seugnwon; Wang, Yeou-Fang; Terrile, Richard J.
2007-01-01
The paper presents the specific approach taken to formulate the problem in terms of gene encoding, fitness function, and genetic operations. The genome is encoded such that a subset of the scheduling constraints is automatically satisfied. Several fitness functions are formulated to emphasize different aspects of the scheduling problem. The optimal solutions of the different fitness functions demonstrate the trade-off of the scheduling problem and provide insight into a conflict resolution process.
NASA Technical Reports Server (NTRS)
Butler, T. G.
1985-01-01
Some of the problems that confront an analyst in free body modeling, to satisfy rigid body conditions are discussed and with some remedies for these problems are presented. The problems of detecting these culprits at various levels within the analysis are examined. A new method within NASTRAN for checking the model for defects very early in the analysis without requiring the analyst to bear the expense of an eigenvalue analysis before discovering these defects is outlined.
Predictors of job satisfaction among academics at an Iranian university.
Zarafshani, Kiumars; Alibaygi, Amir Hossein
2009-04-01
The overall job satisfaction of 128 faculty of Razi University in Iran was investigated using a modified version of the Minnesota Satisfaction Questionnaire to elicit information in this stratified random sample. Faculty members were most satisfied with intrinsic aspects of the work such as "social service," "activity," and "ability utilization" and less satisfied with extrinsic aspects of work such as "security," "university policies," and "compensation." Publication counts and years of teaching experience contributed significantly to the prediction of overall job satisfaction among these faculty members. Intervention efforts must involve socializing faculty in the early stages of their careers, encouraging them to engage in research activities and write for reputable journals, while providing compensation and job security.
Vichinsky, Elliott; Pakbaz, Zahra; Onyekwere, Onyinye; Porter, John; Swerdlow, Paul; Coates, Thomas; Lane, Peter; Files, Beatrice; Mueller, Brigitta U; Coïc, Lena; Forni, Gian Luca; Fischer, Roland; Marks, Peter; Rofail, Diana; Abetz, Linda; Baladi, Jean-Francois
2008-01-01
There is increasing evidence demonstrating the value of transfusions in sickle cell disease (SCD). However, resultant iron overload can be life threatening if untreated. Chelation therapy with deferoxamine requires parenteral infusions that can negatively impact quality of life and adherence to treatment. As part of a phase II trial, SCD patient-reported outcomes were evaluated. One hundred and ninety-five patients were randomized (2:1) to receive oral deferasirox (5-30 mg/kg/day) or deferoxamine (20-50 mg/kg, 5 days per week); 121 had previously received deferoxamine. At each time point, significantly more patients who had previously received deferoxamine were 'satisfied/very satisfied' with deferasirox, or found treatment to be 'convenient/very convenient' compared with deferoxamine (p < 0.001). In these patients, fewer hours were lost from daily activities with deferasirox than deferoxamine treatment. Most patients (77%) preferred deferasirox, and more were willing to continue taking deferasirox than deferoxamine at end-of-study (84 vs. 11%, respectively). Patients with SCD are therefore more satisfied with deferasirox, which has a lower impact on daily activities than deferoxamine. Given the high levels of satisfaction, it is likely that quality of life will be improved. These results also suggest that treatment adherence with deferasirox may be better than with deferoxamine, which should lead to improved long-term outcomes. 2008 S. Karger AG, Basel.
Müller, K I; Alstadhaug, K B; Bekkelund, S I
2017-06-01
We investigated non-acute headache patients' long-term satisfaction with a telemedicine consultation and consultation preferences in northern Norway. We hypothesized that patients were not less satisfied with telemedicine than traditional consultations. We also examined the influence of gender, age and education on satisfaction. For 2.5 years, patients were consecutively screened, recruited and randomly assigned to telemedicine or traditional visits with a consultation at a neurological outpatient department. The primary endpoint was frequency of satisfied patients at 3 and 12 months. Secondary endpoints were satisfaction with consultation, communication, information, diagnosis, advice and prescriptions, and preferred visit form at 12 months. Of 402 participants, 279 (69.4%) answered questionnaires at both 3 and 12 month, and 291 (72.4%) responded at 12 months. The long-term satisfaction of telemedicine patients was 124/145 (85.5%) compared with 118/134 (88.1%) in the traditional group (P = 0.653). The groups did not differ with respect to secondary endpoints, but females were more satisfied with telemedicine communication (P = 0.027). In the telemedicine group, 99/147 (67.3%) were indifferent to the type of consultation. Age and education did not alter the primary results. At 1 year after a specialist evaluation for headache, telemedicine patients did not express less satisfaction than those with traditional consultation. Telemedicine specialist consultations may be a good alternative for headache patients in secondary care. © 2017 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.
When is informed consent required in cluster randomized trials in health research?
2011-01-01
This article is part of a series of papers examining ethical issues in cluster randomized trials (CRTs) in health research. In the introductory paper in this series, we set out six areas of inquiry that must be addressed if the cluster trial is to be set on a firm ethical foundation. This paper addresses the second of the questions posed, namely, from whom, when, and how must informed consent be obtained in CRTs in health research? The ethical principle of respect for persons implies that researchers are generally obligated to obtain the informed consent of research subjects. Aspects of CRT design, including cluster randomization, cluster level interventions, and cluster size, present challenges to obtaining informed consent. Here we address five questions related to consent and CRTs: How can a study proceed if informed consent is not possible? Is consent to randomization always required? What information must be disclosed to potential subjects if their cluster has already been randomized? Is passive consent a valid substitute for informed consent? Do health professionals have a moral obligation to participate as subjects in CRTs designed to improve professional practice? We set out a framework based on the moral foundations of informed consent and international regulatory provisions to address each of these questions. First, when informed consent is not possible, a study may proceed if a research ethics committee is satisfied that conditions for a waiver of consent are satisfied. Second, informed consent to randomization may not be required if it is not possible to approach subjects at the time of randomization. Third, when potential subjects are approached after cluster randomization, they must be provided with a detailed description of the interventions in the trial arm to which their cluster has been randomized; detailed information on interventions in other trial arms need not be provided. Fourth, while passive consent may serve a variety of practical ends, it is not a substitute for valid informed consent. Fifth, while health professionals may have a moral obligation to participate as subjects in research, this does not diminish the necessity of informed consent to study participation. PMID:21906277
Honey Bees Inspired Optimization Method: The Bees Algorithm.
Yuce, Baris; Packianather, Michael S; Mastrocinque, Ernesto; Pham, Duc Truong; Lambiase, Alfredo
2013-11-06
Optimization algorithms are search methods where the goal is to find an optimal solution to a problem, in order to satisfy one or more objective functions, possibly subject to a set of constraints. Studies of social animals and social insects have resulted in a number of computational models of swarm intelligence. Within these swarms their collective behavior is usually very complex. The collective behavior of a swarm of social organisms emerges from the behaviors of the individuals of that swarm. Researchers have developed computational optimization methods based on biology such as Genetic Algorithms, Particle Swarm Optimization, and Ant Colony. The aim of this paper is to describe an optimization algorithm called the Bees Algorithm, inspired from the natural foraging behavior of honey bees, to find the optimal solution. The algorithm performs both an exploitative neighborhood search combined with random explorative search. In this paper, after an explanation of the natural foraging behavior of honey bees, the basic Bees Algorithm and its improved versions are described and are implemented in order to optimize several benchmark functions, and the results are compared with those obtained with different optimization algorithms. The results show that the Bees Algorithm offering some advantage over other optimization methods according to the nature of the problem.
A predictive machine learning approach for microstructure optimization and materials design
Liu, Ruoqian; Kumar, Abhishek; Chen, Zhengzhang; ...
2015-06-23
This paper addresses an important materials engineering question: How can one identify the complete space (or as much of it as possible) of microstructures that are theoretically predicted to yield the desired combination of properties demanded by a selected application? We present a problem involving design of magnetoelastic Fe-Ga alloy microstructure for enhanced elastic, plastic and magnetostrictive properties. While theoretical models for computing properties given the microstructure are known for this alloy, inversion of these relationships to obtain microstructures that lead to desired properties is challenging, primarily due to the high dimensionality of microstructure space, multi-objective design requirement and non-uniquenessmore » of solutions. These challenges render traditional search-based optimization methods incompetent in terms of both searching efficiency and result optimality. In this paper, a route to address these challenges using a machine learning methodology is proposed. A systematic framework consisting of random data generation, feature selection and classification algorithms is developed. In conclusion, experiments with five design problems that involve identification of microstructures that satisfy both linear and nonlinear property constraints show that our framework outperforms traditional optimization methods with the average running time reduced by as much as 80% and with optimality that would not be achieved otherwise.« less
What keeps Melbourne GPs satisfied in their jobs?
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 (p<0.01). Most frequently nominated themes for satisfaction were job variety, longitudinal patient relationships, belief in the value of the work 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.
47 CFR 95.192 - (FRS Rule 2) Authorized locations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... SERVICES PERSONAL RADIO SERVICES Family Radio Service (FRS) General Provisions § 95.192 (FRS Rule 2... problem with the Arecibo Observatory. If the Commission determines that an operator has satisfied its...
47 CFR 95.192 - (FRS Rule 2) Authorized locations.
Code of Federal Regulations, 2010 CFR
2010-10-01
... SERVICES PERSONAL RADIO SERVICES Family Radio Service (FRS) General Provisions § 95.192 (FRS Rule 2... problem with the Arecibo Observatory. If the Commission determines that an operator has satisfied its...
Physician Job Satisfaction across Six Major Specialties
ERIC Educational Resources Information Center
Duffy, Ryan D.; Richard, George V.
2006-01-01
A random sample of 763 physicians was surveyed to examine the relation of 18 critical work-related factors to job satisfaction. On the whole, physicians reported that they were satisfied with their careers and believed that caring for patients, sense of accomplishment, continuity of care, autonomy, and personal time were the five most important…
ERIC Educational Resources Information Center
Weeks, Ann A.; Sillin, Andrew
A study was conducted at Dutchess Community College (DCC) to provide a broad picture of the further education and employment status of DCC alumni several years after graduation and to determine how satisfied alumni were with the education and services provided by the college. Survey questionnaires were mailed to a random sample of 20% of DCC…
Doha, E.H.; Abd-Elhameed, W.M.; Youssri, Y.H.
2014-01-01
Two families of certain nonsymmetric generalized Jacobi polynomials with negative integer indexes are employed for solving third- and fifth-order two point boundary value problems governed by homogeneous and nonhomogeneous boundary conditions using a dual Petrov–Galerkin method. The idea behind our method is to use trial functions satisfying the underlying boundary conditions of the differential equations and the test functions satisfying the dual boundary conditions. The resulting linear systems from the application of our method are specially structured and they can be efficiently inverted. The use of generalized Jacobi polynomials simplify the theoretical and numerical analysis of the method and also leads to accurate and efficient numerical algorithms. The presented numerical results indicate that the proposed numerical algorithms are reliable and very efficient. PMID:26425358
Backscattering from a randomly rough dielectric surface
NASA Technical Reports Server (NTRS)
Fung, Adrian K.; Li, Zongqian; Chen, K. S.
1992-01-01
A backscattering model for scattering from a randomly rough dielectric surface is developed based on an approximate solution of a pair of integral equations for the tangential surface fields. Both like and cross-polarized scattering coefficients are obtained. It is found that the like polarized scattering coefficients contain two types of terms: single scattering terms and multiple scattering terms. The single scattering terms in like polarized scattering are shown to reduce the first-order solutions derived from the small perturbation method when the roughness parameters satisfy the slightly rough conditions. When surface roughnesses are large but the surface slope is small, only a single scattering term corresponding to the standard Kirchhoff model is significant. If the surface slope is large, the multiple scattering term will also be significant. The cross-polarized backscattering coefficients satisfy reciprocity and contain only multiple scattering terms. The difference between vertical and horizontal scattering coefficients is found to increase with the dielectric constant and is generally smaller than that predicted by the first-order small perturbation model. Good agreements are obtained between this model and measurements from statistically known surfaces.
Clayton, Anita H; Althof, Stanley E; Kingsberg, Sheryl; DeRogatis, Leonard R; Kroll, Robin; Goldstein, Irwin; Kaminetsky, Jed; Spana, Carl; Lucas, Johna; Jordan, Robert; Portman, David J
2016-01-01
Aim: Evaluate efficacy/safety of bremelanotide (BMT), a melanocortin-receptor-4 agonist, to treat female sexual dysfunctions in premenopausal women. Methods: Patients randomized to receive placebo or BMT 0.75, 1.25 or 1.75 mg self-administered subcutaneously, as desired, over 12 weeks. Primary end point was change in satisfying sexual events/month. Secondary end points included total score changes on female sexual function index and female sexual distress scale-desire/arousal/orgasm. Results: Efficacy data, n = 327. For 1.25/1.75-mg pooled versus placebo, mean changes from baseline to study end were +0.7 versus +0.2 satisfying sexual events/month (p = 0.0180), +3.6 versus +1.9 female sexual function index total score (p = 0.0017), −11.1 versus −6.8 female sexual distress scale-desire/arousal/orgasm total score (p = 0.0014). Adverse events: nausea, flushing, headache. Conclusion: In premenopausal women with female sexual dysfunctions, self-administered, as desired, subcutaneous BMT was safe, effective, and well tolerated (NCT01382719). PMID:27181790
Requirements based system risk modeling
NASA Technical Reports Server (NTRS)
Meshkat, Leila; Cornford, Steven; Feather, Martin
2004-01-01
The problem that we address in this paper is assessing the expected degree of success of the system or mission based on the degree to which each requirement is satisfied and the relative weight of the requirements. We assume a complete list of the requirements, the relevant risk elements and their probability of occurrence and the quantified effect of the risk elements on the requirements. In order to assess the degree to which each requirement is satisfied, we need to determine the effect of the various risk elements on the requirement.
Widespread pain: is an improved classification possible?
MacFarlane, G J; Croft, P R; Schollum, J; Silman, A J
1996-09-01
The classification of widespread pain, proposed by the American College of Rheumatology (ACR) for use in the clinic as a screen for fibromyalgia, as described, does not require truly widespread pain. Studies considering the epidemiology of widespread pain per se may therefore require a definition with greater face validity, which might also show enhanced associations with other physical and psychological measures. We aimed to develop a more coherent definition of widespread pain for use in epidemiological studies and to compare performance in identifying individuals with significant morbidity. A group of 172 subjects who had participated in a community based study on the occurrence of pain were identified and categorized by their pain experience as indicated on line drawings of the body according to ACR definition and to a new, more stringent definition that required the presence of more diffuse limb pain. A number of other clinical and psychological measures were recorded for these individuals and the association between their pain status measures and these other variables was assessed and compared. Persons satisfying the newly proposed definition for chronic widespread pain, in comparison with those who satisfied only the present ACR definition, had a significantly higher score on the General Health Questionnaire [median difference (MD) 7.95% CI 1.13], a higher score on the Health and Fatigue Questionnaire (MD 10.95% CI 0.15), and greater problems with sleep (sleep problem score MD 4.95% CI 0.9). Those satisfying the new definition also had a greater number of tender points on examination (MD 3.95% CI -1.7). The morbidity of those satisfying only the present ACR definition was closer to persons who had regional pain. A redefinition of widespread pain has produced a group of subjects whose pain is (a) likely to be more "widespread" and (b) is associated more strongly with factors such as psychological disturbance, fatigue, sleep problems, and tender points, and may be more appropriate in epidemiological studies.
Secure Distributed Detection under Energy Constraint in IoT-Oriented Sensor Networks.
Zhang, Guomei; Sun, Hao
2016-12-16
We study the secure distributed detection problems under energy constraint for IoT-oriented sensor networks. The conventional channel-aware encryption (CAE) is an efficient physical-layer secure distributed detection scheme in light of its energy efficiency, good scalability and robustness over diverse eavesdropping scenarios. However, in the CAE scheme, it remains an open problem of how to optimize the key thresholds for the estimated channel gain, which are used to determine the sensor's reporting action. Moreover, the CAE scheme does not jointly consider the accuracy of local detection results in determining whether to stay dormant for a sensor. To solve these problems, we first analyze the error probability and derive the optimal thresholds in the CAE scheme under a specified energy constraint. These results build a convenient mathematic framework for our further innovative design. Under this framework, we propose a hybrid secure distributed detection scheme. Our proposal can satisfy the energy constraint by keeping some sensors inactive according to the local detection confidence level, which is characterized by likelihood ratio. In the meanwhile, the security is guaranteed through randomly flipping the local decisions forwarded to the fusion center based on the channel amplitude. We further optimize the key parameters of our hybrid scheme, including two local decision thresholds and one channel comparison threshold. Performance evaluation results demonstrate that our hybrid scheme outperforms the CAE under stringent energy constraints, especially in the high signal-to-noise ratio scenario, while the security is still assured.
Secure Distributed Detection under Energy Constraint in IoT-Oriented Sensor Networks
Zhang, Guomei; Sun, Hao
2016-01-01
We study the secure distributed detection problems under energy constraint for IoT-oriented sensor networks. The conventional channel-aware encryption (CAE) is an efficient physical-layer secure distributed detection scheme in light of its energy efficiency, good scalability and robustness over diverse eavesdropping scenarios. However, in the CAE scheme, it remains an open problem of how to optimize the key thresholds for the estimated channel gain, which are used to determine the sensor’s reporting action. Moreover, the CAE scheme does not jointly consider the accuracy of local detection results in determining whether to stay dormant for a sensor. To solve these problems, we first analyze the error probability and derive the optimal thresholds in the CAE scheme under a specified energy constraint. These results build a convenient mathematic framework for our further innovative design. Under this framework, we propose a hybrid secure distributed detection scheme. Our proposal can satisfy the energy constraint by keeping some sensors inactive according to the local detection confidence level, which is characterized by likelihood ratio. In the meanwhile, the security is guaranteed through randomly flipping the local decisions forwarded to the fusion center based on the channel amplitude. We further optimize the key parameters of our hybrid scheme, including two local decision thresholds and one channel comparison threshold. Performance evaluation results demonstrate that our hybrid scheme outperforms the CAE under stringent energy constraints, especially in the high signal-to-noise ratio scenario, while the security is still assured. PMID:27999282
An Improved Memetic Algorithm for Break Scheduling
NASA Astrophysics Data System (ADS)
Widl, Magdalena; Musliu, Nysret
In this paper we consider solving a complex real life break scheduling problem. This problem of high practical relevance arises in many working areas, e.g. in air traffic control and other fields where supervision personnel is working. The objective is to assign breaks to employees such that various constraints reflecting legal demands or ergonomic criteria are satisfied and staffing requirement violations are minimised.
Using Forensic Investigations and CAS to Motivate Student Interest in Mathematics
ERIC Educational Resources Information Center
Leinbach, Patricia; Leinbach, Carl
2010-01-01
In this paper, we are proposing the use of forensic case studies as a means to provide students with interesting problem solving opportunities that capitalise on the popularity of several TV series and shows. It also satisfies their natural curiosity about how answers are found to seemingly complex real life problems. We begin with a very brief…
Mohd Hawari, Nurhanisah; Jawaid, Mohammad; Md Tahir, Paridah; Azmeer, Raja Ahmad
2017-11-01
The aim of this case study was to explore patient satisfaction with the quality of prosthetic leg sockets intended for persons with lower limb amputations. A qualitative study based on in-depth interviews, preceded by a questionnaire session, was carried out with patients from the Rehabilitation Center and Hospital in Malaysia. Twelve out-patient and in-patient amputees with lower limb amputations, specifically below-knee amputations, were chosen randomly. The analysis of patients' narratives aimed to identify the functional and esthetic characteristics of currently used prosthetic leg sockets and any problems related to them. The obtained results indicated that out of the 12 participants, 41.7% and 25% were satisfied and somewhat satisfied with their current prosthetic sockets. Durability and comfort were rated by the participants as the most important characteristics of prosthetic sockets, with 83.3%. As regards the esthetic appearance of the socket, 66.7% of the respondents considered that the most important feature was the material from which the socket was fabricated. Thus, we conclude that current satisfaction levels with the quality of prosthetic sockets among amputees in Malaysia are suitable, prosthesis being preferred by many amputees. The results can be used to direct future research on cosmesis and functionality of prosthetic socket design. Implications for Rehabilitation Case study will help participants to get cost effective prosthetic leg socket. Develop prosthetic leg socket comfortable as comparative to existing one. Help Malaysian government to make policy to develop local prosthetic leg socket at affordable price.
Using Synchronous Boolean Networks to Model Several Phenomena of Collective Behavior
Kochemazov, Stepan; Semenov, Alexander
2014-01-01
In this paper, we propose an approach for modeling and analysis of a number of phenomena of collective behavior. By collectives we mean multi-agent systems that transition from one state to another at discrete moments of time. The behavior of a member of a collective (agent) is called conforming if the opinion of this agent at current time moment conforms to the opinion of some other agents at the previous time moment. We presume that at each moment of time every agent makes a decision by choosing from the set (where 1-decision corresponds to action and 0-decision corresponds to inaction). In our approach we model collective behavior with synchronous Boolean networks. We presume that in a network there can be agents that act at every moment of time. Such agents are called instigators. Also there can be agents that never act. Such agents are called loyalists. Agents that are neither instigators nor loyalists are called simple agents. We study two combinatorial problems. The first problem is to find a disposition of instigators that in several time moments transforms a network from a state where the majority of simple agents are inactive to a state with the majority of active agents. The second problem is to find a disposition of loyalists that returns the network to a state with the majority of inactive agents. Similar problems are studied for networks in which simple agents demonstrate the contrary to conforming behavior that we call anticonforming. We obtained several theoretical results regarding the behavior of collectives of agents with conforming or anticonforming behavior. In computational experiments we solved the described problems for randomly generated networks with several hundred vertices. We reduced corresponding combinatorial problems to the Boolean satisfiability problem (SAT) and used modern SAT solvers to solve the instances obtained. PMID:25526612
Kagashe, G A B; Rwebangila, F
2011-08-01
Since the establishment of free HIV/AIDS care and treatment services in Tanzania a lot of research has been done to assess how health care providers discharge their duties in these clinics. Little research however has been done regarding satisfaction of HIV patients with free health care services provided. To determine satisfaction of HIV patients with health care services provided at the HIV clinics and specifically, to determine patients' satisfaction with the general physical environment of the clinic and with services offered by doctors, nurses, laboratory, and pharmacy. A cross-sectional study was conducted at Muhimbili National Hospital (MNH) and Amana hospital. A total of 375 patients attending outpatient HIV clinics were selected randomly and interviewed using a questionnaire, after obtaining a verbal consent. Data collected was analyzed using Epi-info program version 6. Patients at Amana Hospital clinic were either very satisfied (44.3%) or satisfied (55.7%) and none were unsatisfied, while at MNH clinic 1.1% patients were very satisfied while (94.7%) were satisfied and (4.2%) were unsatisfied with health care services provided. Lack of privacy when consulting with doctors and the dispenser contributed to patients' unsatisfaction with the services. Most of the participants were satisfied with the services provided at the two clinics. However at MNH, a few patients were unsatisfied due to lack of privacy during consultation with doctors and with the pharmacy services.
Multiple Positive Solutions in the Second Order Autonomous Nonlinear Boundary Value Problems
NASA Astrophysics Data System (ADS)
Atslega, Svetlana; Sadyrbaev, Felix
2009-09-01
We construct the second order autonomous equations with arbitrarily large number of positive solutions satisfying homogeneous Dirichlet boundary conditions. Phase plane approach and bifurcation of solutions are the main tools.
Requirements based system level risk modeling
NASA Technical Reports Server (NTRS)
Meshkat, Leila; Cornford, Steven; Feather, Martin
2004-01-01
The problem that we address in this paper is assessing the expected degree of success of the system or mission based on the degree to which each requirement is satisfied and the relative weight of the requirements.
Solving Open Job-Shop Scheduling Problems by SAT Encoding
NASA Astrophysics Data System (ADS)
Koshimura, Miyuki; Nabeshima, Hidetomo; Fujita, Hiroshi; Hasegawa, Ryuzo
This paper tries to solve open Job-Shop Scheduling Problems (JSSP) by translating them into Boolean Satisfiability Testing Problems (SAT). The encoding method is essentially the same as the one proposed by Crawford and Baker. The open problems are ABZ8, ABZ9, YN1, YN2, YN3, and YN4. We proved that the best known upper bounds 678 of ABZ9 and 884 of YN1 are indeed optimal. We also improved the upper bound of YN2 and lower bounds of ABZ8, YN2, YN3 and YN4.
Proceedings of the First NASA Formal Methods Symposium
NASA Technical Reports Server (NTRS)
Denney, Ewen (Editor); Giannakopoulou, Dimitra (Editor); Pasareanu, Corina S. (Editor)
2009-01-01
Topics covered include: Model Checking - My 27-Year Quest to Overcome the State Explosion Problem; Applying Formal Methods to NASA Projects: Transition from Research to Practice; TLA+: Whence, Wherefore, and Whither; Formal Methods Applications in Air Transportation; Theorem Proving in Intel Hardware Design; Building a Formal Model of a Human-Interactive System: Insights into the Integration of Formal Methods and Human Factors Engineering; Model Checking for Autonomic Systems Specified with ASSL; A Game-Theoretic Approach to Branching Time Abstract-Check-Refine Process; Software Model Checking Without Source Code; Generalized Abstract Symbolic Summaries; A Comparative Study of Randomized Constraint Solvers for Random-Symbolic Testing; Component-Oriented Behavior Extraction for Autonomic System Design; Automated Verification of Design Patterns with LePUS3; A Module Language for Typing by Contracts; From Goal-Oriented Requirements to Event-B Specifications; Introduction of Virtualization Technology to Multi-Process Model Checking; Comparing Techniques for Certified Static Analysis; Towards a Framework for Generating Tests to Satisfy Complex Code Coverage in Java Pathfinder; jFuzz: A Concolic Whitebox Fuzzer for Java; Machine-Checkable Timed CSP; Stochastic Formal Correctness of Numerical Algorithms; Deductive Verification of Cryptographic Software; Coloured Petri Net Refinement Specification and Correctness Proof with Coq; Modeling Guidelines for Code Generation in the Railway Signaling Context; Tactical Synthesis Of Efficient Global Search Algorithms; Towards Co-Engineering Communicating Autonomous Cyber-Physical Systems; and Formal Methods for Automated Diagnosis of Autosub 6000.
Rudman, W J; Gumbita, L
1995-05-01
The article describes a study that examined the effects of communication barriers on job satisfaction and perceived work productivity. Data for this study were collected from a stratified random sample of health information management professionals (n = 237). In general, supervisors and employees had similar responses on all three measures. Both supervisors and employees focused on defensiveness and personality conflicts as important barriers to communication, personal satisfaction with work and job pride as the most satisfying elements of their work, and control over the work environment as the least satisfying work condition. Also in general, personality conflicts among workers and lack of organizational skills had the strongest effects on job satisfaction and perceived work productivity.
[Service use patterns among adults with mental health problems in Chile].
Vicente, Benjamín; Kohn, Robert; Saldivia, Sandra; Rioseco, Pedro; Torres, Silverio
2005-01-01
To describe the patterns in the use of general health services and specialized health services among adults with mental health problems in Chile, as well as those persons' level of satisfaction with the services. The overall objective was to optimize the use of the limited resources available for mental health care in the countries of the Americas, especially Chile. The diagnoses and the patterns of use of mental health services were obtained from the Chilean Study of Psychiatric Prevalence (Estudio Chileno de Prevalencia Psiquiátrica). That representative research on the adult population of Chile was based on a stratified random sample of 2,987 people 15 years old and older, done over the period of 1992 to 1999. The psychiatric diagnoses were obtained using the Composite International Diagnostic Interview (CIDI). The interviewees were also asked about their use of general health care services and of mental health services in the preceding six months, as well as any barriers to accessing the services. More than 44% of the interviewees had had contact with some type of health service during the six months prior to the study, but only 5.6% received specialized care. Those who presented with a diagnosis of obsessive-compulsive disorder or of panic disorder consulted more frequently, but not in specialized centers. Consumption of substances such as alcohol and drugs as well as antisocial personality disorder were associated with a low level of consultation. When asked about sources of assistance for mental health problems, the majority of the interviewees mentioned only the formal health care system. More than 75% of the interviewees said that they were satisfied or very satisfied with the care that they had received. Our results confirm the existence of a wide gap between the need for care and the treatment that is actually received. The informal and folkloric alternative resources (priests, family members, healers, herbalists, etc.) were used less frequently than is generally believed to be true. The indirect barriers of access to services--linked to a lack of knowledge and to stigma--were more frequent than were the direct barriers. A sizable number of people who did not have a positive diagnosis on the CIDI utilized mental health services.
Planning as a Precursor to Scheduling for Space Station Payload Operations
NASA Technical Reports Server (NTRS)
Howell, Eric; Maxwell, Theresa
1995-01-01
Contemporary schedulers attempt to solve the problem of best fitting a set of activities into an available timeframe while still satisfying the necessary constraints. This approach produces results which are optimized for the region of time the scheduler is able to process, satisfying the near term goals of the operation. In general the scheduler is not able to reason about the activities which precede or follow the window into which it is inputs to scheduling so that the intermediate placing activities. This creates a problem for operations which are composed of many activities spanning long durations (which exceed the scheduler's reasoning horizon) such as the continuous operations environment for payload operations on the Space Station. Not only must the near term scheduling objectives be met, but somehow the results of near term scheduling must be made to support the attainment of long term goals.
Content and user-based music visual analysis
NASA Astrophysics Data System (ADS)
Guo, Xiaochun; Tang, Lei
2015-12-01
In recent years, people's ability to collect music got enhanced greatly. Many people who prefer listening music offline even stored thousands of music on their local storage or portable device. However, their ability to deal with music information has not been improved accordingly, which results in two problems. One is how to find out the favourite songs from large music dataset and satisfy different individuals. The other one is how to compose a play list quickly. To solve these problems, the authors proposed a content and user-based music visual analysis approach. We first developed a new recommendation algorithm based on the content of music and user's behaviour, which satisfy individual's preference. Then, we make use of visualization and interaction tools to illustrate the relationship between songs and help people compose a suitable play list. At the end of this paper, a survey is mentioned to show that our system is available and effective.
Research on LLCL Filtering Grid - Connected inverter under the Control of PFI
NASA Astrophysics Data System (ADS)
Li, Ren-qing; Zong, Ke-yong; Wang, Yan-ping; Li, Yang; Zhang, Jing
2018-03-01
This passage puts forward a kind of LLCL inverter which is based on the proportional feedback integral(PFI) control so as so satisfy the request of the grid-current outputed by the renewable energy generation system. The passage builds the topological graph of grid-connected inverter and makes an analysis of principle of linear superposition aims to reveal the essence of the problem of steady-state error that exists in proportional integral control. We use LLCL filter and the method of passive damping to solve the problem of resonant peak. We make simulation of the grid system with the software named MATLAB/Simulink. The result shows that the grid current enters steady state quickly and in the same time, which has the identical phase and frequency of grid-voltage. The harmonic content in grid current satisfies the request of grid standard.
Establishing an NP-staffed minor emergency area.
Buchanan, L; Powers, R D
1997-04-01
Patients with problems of high acuity need fully trained emergency physicians and nurses. Some patients with nonurgent problems can be cared for within the emergency department (ED) in a lower-cost setting designed and staffed specifically for this purpose. Staffing a fast track or minor emergency area (MEA) with nurse practitioners (NPs) is one way to satisfy the ED's care needs. One site analysis of the effectiveness of NPs indicates that patients are satisfied with their care, that nurses' interpersonal skills are better than those of physicians, that technical skills are equivalent, that patient outcomes are equivalent or superior and that NPs improve access to care. A nurse practitioner-staffed minor emergency area provides high quality care for approximately 21% of this site's adult emergency department population. Patients are triaged based on set criteria, allowing for short treatment times. The physical layout, triage criteria, and the NPs' scope of practice in the level 1 trauma center's ED are detailed.
Satisfiability of logic programming based on radial basis function neural networks
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hamadneh, Nawaf; Sathasivam, Saratha; Tilahun, Surafel Luleseged
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 appliedmore » 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.« less
Discretizing singular point sources in hyperbolic wave propagation problems
Petersson, N. Anders; O'Reilly, Ossian; Sjogreen, Bjorn; ...
2016-06-01
Here, we develop high order accurate source discretizations for hyperbolic wave propagation problems in first order formulation that are discretized by finite difference schemes. By studying the Fourier series expansions of the source discretization and the finite difference operator, we derive sufficient conditions for achieving design accuracy in the numerical solution. Only half of the conditions in Fourier space can be satisfied through moment conditions on the source discretization, and we develop smoothness conditions for satisfying the remaining accuracy conditions. The resulting source discretization has compact support in physical space, and is spread over as many grid points as themore » number of moment and smoothness conditions. In numerical experiments we demonstrate high order of accuracy in the numerical solution of the 1-D advection equation (both in the interior and near a boundary), the 3-D elastic wave equation, and the 3-D linearized Euler equations.« less
Yoshida, Hiroaki; Kobayashi, Takayuki; Hayashi, Hidemitsu; Kinjo, Tomoyuki; Washizu, Hitoshi; Fukuzawa, Kenji
2014-07-01
A boundary scheme in the lattice Boltzmann method (LBM) for the convection-diffusion equation, which correctly realizes the internal boundary condition at the interface between two phases with different transport properties, is presented. The difficulty in satisfying the continuity of flux at the interface in a transient analysis, which is inherent in the conventional LBM, is overcome by modifying the collision operator and the streaming process of the LBM. An asymptotic analysis of the scheme is carried out in order to clarify the role played by the adjustable parameters involved in the scheme. As a result, the internal boundary condition is shown to be satisfied with second-order accuracy with respect to the lattice interval, if we assign appropriate values to the adjustable parameters. In addition, two specific problems are numerically analyzed, and comparison with the analytical solutions of the problems numerically validates the proposed scheme.
NASA Technical Reports Server (NTRS)
Dekorvin, Andre
1992-01-01
The Dempster-Shafer theory of evidence is applied to a multiattribute decision making problem whereby the decision maker (DM) must compromise with available alternatives, none of which exactly satisfies his ideal. The decision mechanism is constrained by the uncertainty inherent in the determination of the relative importance of each attribute element and the classification of existing alternatives. The classification of alternatives is addressed through expert evaluation of the degree to which each element is contained in each available alternative. The relative importance of each attribute element is determined through pairwise comparisons of the elements by the decision maker and implementation of a ratio scale quantification method. Then the 'belief' and 'plausibility' that an alternative will satisfy the decision maker's ideal are calculated and combined to rank order the available alternatives. Application to the problem of selecting computer software is given.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kogalovskii, M.R.
This paper presents a review of problems related to statistical database systems, which are wide-spread in various fields of activity. Statistical databases (SDB) are referred to as databases that consist of data and are used for statistical analysis. Topics under consideration are: SDB peculiarities, properties of data models adequate for SDB requirements, metadata functions, null-value problems, SDB compromise protection problems, stored data compression techniques, and statistical data representation means. Also examined is whether the present Database Management Systems (DBMS) satisfy the SDB requirements. Some actual research directions in SDB systems are considered.
Portfolios of quantum algorithms.
Maurer, S M; Hogg, T; Huberman, B A
2001-12-17
Quantum computation holds promise for the solution of many intractable problems. However, since many quantum algorithms are stochastic in nature they can find the solution of hard problems only probabilistically. Thus the efficiency of the algorithms has to be characterized by both the expected time to completion and the associated variance. In order to minimize both the running time and its uncertainty, we show that portfolios of quantum algorithms analogous to those of finance can outperform single algorithms when applied to the NP-complete problems such as 3-satisfiability.
Generalized INF-SUP condition for Chebyshev approximation of the Navier-Stokes equations
NASA Technical Reports Server (NTRS)
Bernardi, Christine; Canuto, Claudio; Maday, Yvon
1986-01-01
An abstract mixed problem and its approximation are studied; both are well-posed if and only if several inf-sup conditions are satisfied. These results are applied to a spectral Galerkin method for the Stokes problem in a square, when it is formulated in Chebyshev weighted Sobolev spaces. Finally, a collocation method for the Navier-Stokes equations at Chebyshev nodes is analyzed.
ERIC Educational Resources Information Center
Hodge, Steven; Atkins, Liz; Simons, Michele
2016-01-01
Debate about the benefits and problems with competency-based training (CBT) has not paid sufficient attention to the fact that the model satisfies a unique, contemporary demand for cross-occupational curriculum. The adoption of CBT in the UK and Australia, along with at least some of its problems, can be understood in terms of this demand. We…
A Verification-Driven Approach to Control Analysis and Tuning
NASA Technical Reports Server (NTRS)
Crespo, Luis G.; Kenny, Sean P.; Giesy, Daniel P.
2008-01-01
This paper proposes a methodology for the analysis and tuning of controllers using control verification metrics. These metrics, which are introduced in a companion paper, measure the size of the largest uncertainty set of a given class for which the closed-loop specifications are satisfied. This framework integrates deterministic and probabilistic uncertainty models into a setting that enables the deformation of sets in the parameter space, the control design space, and in the union of these two spaces. In regard to control analysis, we propose strategies that enable bounding regions of the design space where the specifications are satisfied by all the closed-loop systems associated with a prescribed uncertainty set. When this is unfeasible, we bound regions where the probability of satisfying the requirements exceeds a prescribed value. In regard to control tuning, we propose strategies for the improvement of the robust characteristics of a baseline controller. Some of these strategies use multi-point approximations to the control verification metrics in order to alleviate the numerical burden of solving a min-max problem. Since this methodology targets non-linear systems having an arbitrary, possibly implicit, functional dependency on the uncertain parameters and for which high-fidelity simulations are available, they are applicable to realistic engineering problems..
Random Walks on Cartesian Products of Certain Nonamenable Groups and Integer Lattices
NASA Astrophysics Data System (ADS)
Vishnepolsky, Rachel
A random walk on a discrete group satisfies a local limit theorem with power law exponent \\alpha if the return probabilities follow the asymptotic law. P{ return to starting point after n steps } ˜ Crhonn-alpha.. A group has a universal local limit theorem if all random walks on the group with finitely supported step distributions obey a local limit theorem with the same power law exponent. Given two groups that obey universal local limit theorems, it is not known whether their cartesian product also has a universal local limit theorem. We settle the question affirmatively in one case, by considering a random walk on the cartesian product of a nonamenable group whose Cayley graph is a tree, and the integer lattice. As corollaries, we derive large deviations estimates and a central limit theorem.
Decay of random correlation functions for unimodal maps
NASA Astrophysics Data System (ADS)
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.
Mahawar, Kamal K; Borg, Cynthia-Michelle; Agarwal, Sanjay; Riebeiro, Rui; De Luca, Maurizio; Small, Peter K
2017-04-01
There is currently no consensus on the criteria for inclusion of new bariatric procedures into routine clinical practice. This study canvasses bariatric surgeons in an attempt to define these criteria. Bariatric Surgeons from around the world were invited to participate in a questionnaire-based survey on SurveyMonkey ®. 396 bariatric surgeons, 337 International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) members, took the survey. Five clinical studies conducted under the strict monitoring of an Institutional Review Board would satisfy most surgeons (67.7 %, n = 266). When asked regarding the number of patients in these studies, a cumulative number of 500 patients would satisfy 64.5 % (n = 255) of the surgeons. Most respondents regarded endorsement by their national society and IFSO as 'very important' or 'extremely important'. An overwhelming 74.4 % (n = 294) felt that every new procedure should undergo a randomized comparison against one of the established alternatives like Roux-en-Y Gastric Bypass or Sleeve Gastrectomy. Evaluation of a new bariatric procedure in at least 5 adequately supervised clinical studies (four of which must be randomized comparisons with one of the existing alternatives) reporting at least 5 years results on a minimum of 500 patients would satisfy majority of bariatric surgeons for the inclusion of a new bariatric procedure into clinical practice. The findings of this survey are simply aimed at starting a discussion on this topic and cannot be used to influence the ground reality until an international consensus can be reached amongst experts.
Development of High-Power Hall Thruster Power Processing Units at NASA GRC
NASA Technical Reports Server (NTRS)
Pinero, Luis R.; Bozak, Karin E.; Santiago, Walter; Scheidegger, Robert J.; Birchenough, Arthur G.
2015-01-01
NASA GRC successfully designed, built and tested four different power processor concepts for high power Hall thrusters. Each design satisfies unique goals including the evaluation of a novel silicon carbide semiconductor technology, validation of innovative circuits to overcome the problems with high input voltage converter design, development of a direct-drive unit to demonstrate potential benefits, or simply identification of lessonslearned from the development of a PPU using a conventional design approach. Any of these designs could be developed further to satisfy NASA's needs for high power electric propulsion in the near future.
Lightweight design of automobile frame based on magnesium alloy
NASA Astrophysics Data System (ADS)
Lyu, R.; Jiang, X.; Minoru, O.; Ju, D. Y.
2018-06-01
The structural performance and lightweighting of car base frame design is a challenging task due to all the performance targets that must be satisfied. In this paper, three kinds of materials (iron, aluminum and magnesium alloy) replacement along with section design optimization strategy is proposed to develop a lightweight car frame structure to satisfy the tensile and safety while reducing weight. Two kinds of cross-sections are considered as the design variables. Using Ansys static structure, the design optimization problem is solved, comparing the results of each step, structure of the base flame is optimized for lightweight.
Comment on "Exact solution of resonant modes in a rectangular resonator".
Gutiérrez-Vega, Julio C; Bandres, Miguel A
2006-08-15
We comment on the recent Letter by J. Wu and A. Liu [Opt. Lett. 31, 1720 (2006)] in which an exact scalar solution to the resonant modes and the resonant frequencies in a two-dimensional rectangular microcavity were presented. The analysis is incorrect because (a) the field solutions were imposed to satisfy simultaneously both Dirichlet and Neumann boundary conditions at the four sides of the rectangle, leading to an overdetermined problem, and (b) the modes in the cavity were expanded using an incorrect series ansatz, leading to an expression for the mode fields that does not satisfy the Helmholtz equation.
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.
Inficon Transpector MPH Mass Spectrometer Random Vibration Test Report
NASA Technical Reports Server (NTRS)
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.
Meals Enhancing Nutrition after Discharge (MEND): Findings from a Pilot Randomized Controlled Trial
Campbell, Anthony D.; Godfryd, Alice; Flood, Kellie; Kitchin, Elizabeth; Kilgore, Meredith L.; Allocca, Sally; Locher, Julie L.
2016-01-01
Background After older adults experience episodes of poor health or are hospitalized, they may not return to pre-morbid eating behaviors. Furthermore, poor nutrition increases hospital readmission risk, but evidence-based interventions addressing these risks are limited. Objective The pilot study’s objective was to evaluate the feasibility of conducting a randomized controlled trial assessing a post-discharge home-delivered meals program’s impact on older adults’ nutritional intake and hospital readmissions and to assess patient acceptability and satisfaction with the program. The aims of the study were to 1) to evaluate successful recruitment, randomization, and retention of at least 80% of the 24 participants sought; 2) to compare the outcomes of hospital readmission and total daily caloric intake between participants in the intervention and control groups; and 3) to assess patient acceptability and satisfaction with the program. Design This study used a two-arm randomized controlled trial design, and baseline data were collected at enrollment; three 24-hour food recalls were collected during the intervention period; and health services utilization and intervention satisfaction was evaluated 45 days post-discharge. Participants/setting Twenty-four patients from the University of Alabama at Birmingham (UAB) Hospital’s Acute Care for Elders Unit were enrolled from May 2014 to June 2015. They were 65 or older, at risk of malnutrition, cognitively intact, able to communicate, discharged to a place where the patient or family was responsible for preparing meals, and diagnosed with congestive heart failure, chronic obstructive pulmonary disease, acute myocardial infarction, or pneumonia. Final analysis included 21 participants. Intervention The intervention group received 10 days of home-delivered meals and nutrition education; the control group received usual care and nutrition education. Main outcome measures The main outcome was intervention feasibility, measured by recruitment and retention goals. Hospital readmissions, caloric intake, and satisfaction with the intervention were also evaluated. Statistical analyses performed Univariate and bivariate parametric statistics were used to evaluate differences between groups. Goals for success were identified to assess feasibility of conducting a full-scale study, and outcomes were measured against the goals. Results 87.5% of randomized participants were retained for final data collection, indicating that this intervention study is feasible. There were no significant differences between groups for hospital readmissions; however, caloric intake during the intervention period was greater for intervention vs. control participants (1595 vs. 1235, p=.03). Participants were overwhelmingly satisfied (82–100% satisfied or very satisfied) with staff performance, meal quality, and delivery processes. Conclusions Conducting a randomized controlled trial to assess outcomes of providing home-delivered meals to older adults after hospital discharge in partnership with a small nonprofit organization is feasible and warrants future research. PMID:28065635
Classification with asymmetric label noise: Consistency and maximal denoising
Blanchard, Gilles; Flaska, Marek; Handy, Gregory; ...
2016-09-20
In many real-world classification problems, the labels of training examples are randomly corrupted. Most previous theoretical work on classification with label noise assumes that the two classes are separable, that the label noise is independent of the true class label, or that the noise proportions for each class are known. In this work, we give conditions that are necessary and sufficient for the true class-conditional distributions to be identifiable. These conditions are weaker than those analyzed previously, and allow for the classes to be nonseparable and the noise levels to be asymmetric and unknown. The conditions essentially state that amore » majority of the observed labels are correct and that the true class-conditional distributions are “mutually irreducible,” a concept we introduce that limits the similarity of the two distributions. For any label noise problem, there is a unique pair of true class-conditional distributions satisfying the proposed conditions, and we argue that this pair corresponds in a certain sense to maximal denoising of the observed distributions. Our results are facilitated by a connection to “mixture proportion estimation,” which is the problem of estimating the maximal proportion of one distribution that is present in another. We establish a novel rate of convergence result for mixture proportion estimation, and apply this to obtain consistency of a discrimination rule based on surrogate loss minimization. Experimental results on benchmark data and a nuclear particle classification problem demonstrate the efficacy of our approach. MSC 2010 subject classifications: Primary 62H30; secondary 68T10. Keywords and phrases: Classification, label noise, mixture proportion estimation, surrogate loss, consistency.« less
Classification with asymmetric label noise: Consistency and maximal denoising
DOE Office of Scientific and Technical Information (OSTI.GOV)
Blanchard, Gilles; Flaska, Marek; Handy, Gregory
In many real-world classification problems, the labels of training examples are randomly corrupted. Most previous theoretical work on classification with label noise assumes that the two classes are separable, that the label noise is independent of the true class label, or that the noise proportions for each class are known. In this work, we give conditions that are necessary and sufficient for the true class-conditional distributions to be identifiable. These conditions are weaker than those analyzed previously, and allow for the classes to be nonseparable and the noise levels to be asymmetric and unknown. The conditions essentially state that amore » majority of the observed labels are correct and that the true class-conditional distributions are “mutually irreducible,” a concept we introduce that limits the similarity of the two distributions. For any label noise problem, there is a unique pair of true class-conditional distributions satisfying the proposed conditions, and we argue that this pair corresponds in a certain sense to maximal denoising of the observed distributions. Our results are facilitated by a connection to “mixture proportion estimation,” which is the problem of estimating the maximal proportion of one distribution that is present in another. We establish a novel rate of convergence result for mixture proportion estimation, and apply this to obtain consistency of a discrimination rule based on surrogate loss minimization. Experimental results on benchmark data and a nuclear particle classification problem demonstrate the efficacy of our approach. MSC 2010 subject classifications: Primary 62H30; secondary 68T10. Keywords and phrases: Classification, label noise, mixture proportion estimation, surrogate loss, consistency.« less
Application of the Bootstrap Methods in Factor Analysis.
ERIC Educational Resources Information Center
Ichikawa, Masanori; Konishi, Sadanori
1995-01-01
A Monte Carlo experiment was conducted to investigate the performance of bootstrap methods in normal theory maximum likelihood factor analysis when the distributional assumption was satisfied or unsatisfied. Problems arising with the use of bootstrap methods are highlighted. (SLD)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Birge, J. R.; Qi, L.; Wei, Z.
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) ifmore » an FJ point z satisfies the FJ1-SSOSC, then there exists a neighborhood N(z) of z such that, for any FJ point y element of N(z) {l_brace}z {r_brace} , f{sub 0}(y) {ne} f{sub 0}(z) , where f{sub 0} is the objective function of the problem; (ii) if an FJ point z satisfies the FJ2-SSOSC, then z is a strict local minimum of the problem. The result (i) implies that the entire iteration point sequence generated by the method converges to an FJ point. We also show that if the parameters are chosen large enough, a unit step length can be accepted by the proposed algorithm.« less
Indicators of satisfaction in clickers-aided EFL class.
Yu, Zhonggen
2015-01-01
How to identify whether students are satisfied with clickers-aided EFL class might be largely a mystery for most researchers since satisfaction is deeply hidden in human psychology which is subtle and intangible. This study, by using bivariate correlation analysis and structural equation modeling, survey scales claimed both valid and internally consistent, and data collected from randomly selected 227 participants, explored the indicators of satisfaction in clickers-aided EFL class, together with gender differences in the indicators. It was concluded that satisfaction was positively correlated with interaction, self-efficacy and self-regulation in clickers-aided EFL class without statistically significant gender differences. Furthermore, interaction, self-efficacy and self-regulation were mutually and significantly correlated. Although indicators of satisfaction might not be limited to these three factors, the findings should be helpful to future researchers who desire to determine whether users are satisfied with the polling technology. Then teachers could decide what teaching style and contents should be adopted. In order to satisfy users of clickers, future lecturing might be designed to promote peer interaction, self-efficacy and self-regulation.
Indicators of satisfaction in clickers-aided EFL class
Yu, Zhonggen
2015-01-01
How to identify whether students are satisfied with clickers-aided EFL class might be largely a mystery for most researchers since satisfaction is deeply hidden in human psychology which is subtle and intangible. This study, by using bivariate correlation analysis and structural equation modeling, survey scales claimed both valid and internally consistent, and data collected from randomly selected 227 participants, explored the indicators of satisfaction in clickers-aided EFL class, together with gender differences in the indicators. It was concluded that satisfaction was positively correlated with interaction, self-efficacy and self-regulation in clickers-aided EFL class without statistically significant gender differences. Furthermore, interaction, self-efficacy and self-regulation were mutually and significantly correlated. Although indicators of satisfaction might not be limited to these three factors, the findings should be helpful to future researchers who desire to determine whether users are satisfied with the polling technology. Then teachers could decide what teaching style and contents should be adopted. In order to satisfy users of clickers, future lecturing might be designed to promote peer interaction, self-efficacy and self-regulation. PMID:25999898
2012 Survey of Reserve Components Spouses (RCSS): Tabulations of Responses
2012-09-30
injury/medical problems Child care problems Other family/personal obligation Maternity / paternity leave Labor dispute Weather affected job School...Did you interact with the unit or Service point of contact? ............................. 262 36. How satisfied are you with the level of assistance...I did not interact with the unit or Service point of contact were tabulated separately, as responses to the constructed question Did you interact
Election Verifiability: Cryptographic Definitions and an Analysis of Helios and JCJ
2015-08-06
SHA - 256 [98], we assume that H is a random oracle to prove Theorem 2. Moreover, we assume the sigma protocols used by Helios 4.0 satisfy the...Aspects in Security and Trust, volume 5491 of LNCS, pages 242– 256 . Springer, 2008. [68] Martin Hirt. Receipt-Free K-out-of-L Voting Based on ElGamal
Characteristics and Work Attitudes of Women Working on Campus. Research Report No. 5-76.
ERIC Educational Resources Information Center
Handley, Alice A.; Sedlacek, William E.
A random sample of 390 women employees of the University of Maryland, College Park (130 each from student, classified, and professional employees) were surveyed as to their characteristics and job attitudes. An 80 percent return was achieved, and results showed that the women generally are satisfied with their jobs and generally do not feel…
Computational work and time on finite machines.
NASA Technical Reports Server (NTRS)
Savage, J. E.
1972-01-01
Measures of the computational work and computational delay required by machines to compute functions are given. Exchange inequalities are developed for random access, tape, and drum machines to show that product inequalities between storage and time, number of drum tracks and time, number of bits in an address and time, etc., must be satisfied to compute finite functions on bounded machines.
Optimal control in microgrid using multi-agent reinforcement learning.
Li, Fu-Dong; Wu, Min; He, Yong; Chen, Xin
2012-11-01
This paper presents an improved reinforcement learning method to minimize electricity costs on the premise of satisfying the power balance and generation limit of units in a microgrid with grid-connected mode. Firstly, the microgrid control requirements are analyzed and the objective function of optimal control for microgrid is proposed. Then, a state variable "Average Electricity Price Trend" which is used to express the most possible transitions of the system is developed so as to reduce the complexity and randomicity of the microgrid, and a multi-agent architecture including agents, state variables, action variables and reward function is formulated. Furthermore, dynamic hierarchical reinforcement learning, based on change rate of key state variable, is established to carry out optimal policy exploration. The analysis shows that the proposed method is beneficial to handle the problem of "curse of dimensionality" and speed up learning in the unknown large-scale world. Finally, the simulation results under JADE (Java Agent Development Framework) demonstrate the validity of the presented method in optimal control for a microgrid with grid-connected mode. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sadovskii, V. M., E-mail: sadov@icm.krasn.ru; Sadovskaya, O. V., E-mail: o-sadov@icm.krasn.ru
Based on the generalized rheological method, the mathematical model describing small deformations of a single-phase porous medium without regard to the effects of a fluid or gas in pores is constructed. The change in resistance of a material to the external mechanical impacts at the moment of pore collapse is taken into account by means of the von Mises–Schleicher strength condition. In order to consider irreversible deformations, alongside with the classical yield conditions by von Mises and Tresca– Saint-Venant, the special condition modeling the plastic loss of stability of a porous skeleton is used. The random nature of the poremore » size distribution is taken into account. It is shown that the proposed mathematical model satisfies the principles of thermodynamics of irreversible processes. Phenomenological parameters of the model are determined on the basis of the approximate calculation of the problem on quasi-static loading of a cubic periodicity cell with spherical voids. In the framework of the obtained model, the process of propagation of plane longitudinal waves of the compression in a homogenous porous medium, accompanied by the plastic deformation of a skeleton and the collapse of pores, is analyzed.« less
RACOON: a multiuser QoS design for mobile wireless body area networks.
Cheng, Shihheng; Huang, Chingyao; Tu, Chun Chen
2011-10-01
In this study, Random Contention-based Resource Allocation (RACOON) medium access control (MAC) protocol is proposed to support the quality of service (QoS) for multi-user mobile wireless body area networks (WBANs). Different from existing QoS designs that focus on a single WBAN, a multiuser WBAN QoS should further consider both inter-WBAN interference and inter-WBAN priorities. Similar problems have been studied in both overlapped wireless local area networks (WLANs) and Bluetooth piconets that need QoS supports. However, these solutions are designed for non-medical transmissions that do not consider any priority scheme for medical applications. Most importantly, these studies focus on only static or low mobility networks. Network mobility of WBANs will introduce unnecessary inter-network collisions and energy waste, which are not considered by these solutions. The proposed multiuser-QoS protocol, RACOON, simultaneously satisfies the inter WBAN QoS requirements and overcomes the performance degradation caused by WBAN mobility. Simulation results verify that RACOON provides better latency and energy control, as compared with WBAN QoS protocols without considering the inter-WBAN requirements.
Labor and Management Build Skills in the Hospitality Industry.
ERIC Educational Resources Information Center
Moy, Debbie
1998-01-01
The San Francisco Hotels Partnership is a consortium of hotel operators and unions that addresses skill-development needs in the hospitality industry. Participating workers were very satisfied with the opportunity to learn communication, problem solving, and teamwork skills. (SK)
From Chains for Mean Value Inequalities to Mitrinovic's Problem II
ERIC Educational Resources Information Center
Zhu, Ling
2005-01-01
In this note, an integrated form of some significant means with two variables is provided, and some chains for mean value inequalities are obtained. At the same time, a concise family of algebraic functions appears, which satisfy Mitrinovic's requirements.
Design criteria monograph on axial flow turbines
NASA Technical Reports Server (NTRS)
1975-01-01
Monograph provides guidelines for predicting turbine performance, sizing gas-path elements, and avoiding problems associated with mechanical design and development. Material in monograph is organized along lines of design and development effort necessary to produce turbine that satisfies requirements imposed on it.
Flores, Glenn; Walker, Candy; Lin, Hua; Lee, Michael; Fierro, Marco; Henry, Monica; Massey, Kenneth; Portillo, Alberto
2015-01-01
Six million US children have no health insurance, and substantial racial/ethnic disparities exist. The design, methods, and baseline characteristics are described for Kids' Health Insurance by Educating Lots of Parents (Kids' HELP), the first randomized, clinical trial of the effectiveness of Parent Mentors (PMs) in insuring uninsured minority children. Latino and African-American children eligible for but not enrolled in Medicaid/CHIP were randomized to PMs, or a control group receiving traditional Medicaid/CHIP outreach. PMs are experienced parents with ≥1 Medicaid/CHIP-covered children. PMs received two days of training, and provide intervention families with information on Medicaid/CHIP eligibility, assistance with application submission, and help maintaining coverage. Primary outcomes include obtaining health insurance, time interval to obtain coverage, and parental satisfaction. A blinded assessor contacts subjects monthly for one year to monitor outcomes. Of 49,361 candidates screened, 329 fulfilled eligibility criteria and were randomized. The mean age is seven years for children and 32 years for caregivers; 2/3 are Latino, 1/3 are African-American, and the mean annual family income is $21,857. Half of caregivers were unaware that their uninsured child is Medicaid/CHIP eligible, and 95% of uninsured children had prior insurance. Fifteen PMs completed two-day training sessions. All PMs are female and minority, 60% are unemployed, and the mean annual family income is $20,913. Post-PM-training, overall knowledge/skills test scores significantly increased, and 100% reported being very satisfied/satisfied with the training. Kids' HELP successfully reached target populations, met participant enrollment goals, and recruited and trained PMs. Copyright © 2014 Elsevier Inc. All rights reserved.
Flores, Glenn; Walker, Candy; Lin, Hua; Lee, Michael; Fierro, Marco; Henry, Monica; Massey, Kenneth; Portillo, Alberto
2014-01-01
Background & objectives Six million US children have no health insurance, and substantial racial/ethnic disparities exist. The design, methods, and baseline characteristics are described for Kids’ Health Insurance by Educating Lots of Parents (Kids’ HELP), the first randomized, clinical trial of the effectiveness of Parent Mentors (PMs) in insuring uninsured minority children. Methods & research design Latino and African-American children eligible for but not enrolled in Medicaid/CHIP were randomized to PMs, or a control group receiving traditional Medicaid/CHIP outreach. PMs are experienced parents with ≥ 1 Medicaid/CHIP-covered children. PMs received two days of training, and provide intervention families with information on Medicaid/CHIP eligibility, assistance with application submission, and help maintaining coverage. Primary outcomes include obtaining health insurance, time interval to obtain coverage, and parental satisfaction. A blinded assessor contacts subjects monthly for one year to monitor outcomes. Results Of 49,361 candidates screened, 329 fulfilled eligibility criteria and were randomized. The mean age is seven years for children and 32 years for caregivers; 2/3 are Latino, 1/3 are African-American, and the mean annual family income is $21,857. Half of caregivers were unaware that their uninsured child is Medicaid/CHIP eligible, and 95% of uninsured children had prior insurance. Fifteen PMs completed two-day training sessions. All PMs are female and minority, 60% are unemployed, and the mean annual family income is $20,913. Post-PM-training, overall knowledge/skills test scores significantly increased, and 100% reported being very satisfied/satisfied with the training. Conclusions Kids’ HELP successfully reached target populations, met participant enrollment goals, and recruited and trained PMs. PMID:25476583
Coverage-guaranteed sensor node deployment strategies for wireless sensor networks.
Fan, Gaojuan; Wang, Ruchuan; Huang, Haiping; Sun, Lijuan; Sha, Chao
2010-01-01
Deployment quality and cost are two conflicting aspects in wireless sensor networks. Random deployment, where the monitored field is covered by randomly and uniformly deployed sensor nodes, is an appropriate approach for large-scale network applications. However, their successful applications depend considerably on the deployment quality that uses the minimum number of sensors to achieve a desired coverage. Currently, the number of sensors required to meet the desired coverage is based on asymptotic analysis, which cannot meet deployment quality due to coverage overestimation in real applications. In this paper, we first investigate the coverage overestimation and address the challenge of designing coverage-guaranteed deployment strategies. To overcome this problem, we propose two deployment strategies, namely, the Expected-area Coverage Deployment (ECD) and BOundary Assistant Deployment (BOAD). The deployment quality of the two strategies is analyzed mathematically. Under the analysis, a lower bound on the number of deployed sensor nodes is given to satisfy the desired deployment quality. We justify the correctness of our analysis through rigorous proof, and validate the effectiveness of the two strategies through extensive simulation experiments. The simulation results show that both strategies alleviate the coverage overestimation significantly. In addition, we also evaluate two proposed strategies in the context of target detection application. The comparison results demonstrate that if the target appears at the boundary of monitored region in a given random deployment, the average intrusion distance of BOAD is considerably shorter than that of ECD with the same desired deployment quality. In contrast, ECD has better performance in terms of the average intrusion distance when the invasion of intruder is from the inside of monitored region.
Selection of examples in case-based computer-aided decision systems
Mazurowski, Maciej A.; Zurada, Jacek M.; Tourassi, Georgia D.
2013-01-01
Case-based computer-aided decision (CB-CAD) systems rely on a database of previously stored, known examples when classifying new, incoming queries. Such systems can be particularly useful since they do not need retraining every time a new example is deposited in the case base. The adaptive nature of case-based systems is well suited to the current trend of continuously expanding digital databases in the medical domain. To maintain efficiency, however, such systems need sophisticated strategies to effectively manage the available evidence database. In this paper, we discuss the general problem of building an evidence database by selecting the most useful examples to store while satisfying existing storage requirements. We evaluate three intelligent techniques for this purpose: genetic algorithm-based selection, greedy selection and random mutation hill climbing. These techniques are compared to a random selection strategy used as the baseline. The study is performed with a previously presented CB-CAD system applied for false positive reduction in screening mammograms. The experimental evaluation shows that when the development goal is to maximize the system’s diagnostic performance, the intelligent techniques are able to reduce the size of the evidence database to 37% of the original database by eliminating superfluous and/or detrimental examples while at the same time significantly improving the CAD system’s performance. Furthermore, if the case-base size is a main concern, the total number of examples stored in the system can be reduced to only 2–4% of the original database without a decrease in the diagnostic performance. Comparison of the techniques shows that random mutation hill climbing provides the best balance between the diagnostic performance and computational efficiency when building the evidence database of the CB-CAD system. PMID:18854606
Tseng, Fen-Yu; Shieh, Jeng-Yi; Kao, Tze-Wah; Wu, Chau-Chung; Chu, Tzong-Shinn; Chen, Yen-Yuan
2016-02-01
Although medical humanities courses taught by teachers from nonmedical backgrounds are not unusual now, few studies have compared the outcome of medical humanities courses facilitated by physicians to that by teaching assistants majored in the liberal arts. The objectives of this study were to (1) analyze the satisfaction of medical students with medical humanities problem-based learning (PBL) classes facilitated by nonmedical teaching assistants (TAF) majored in the liberal arts, and those facilitated by the attending physicians (APF) and (2) examine the satisfaction of medical students with clinical medicine-related and clinical medicine-unrelated medical humanities PBL classes.A total of 123 medical students, randomly assigned to 16 groups, participated in this study. There were 16 classes in the course: 8 of them were TAF classes; and the others were APF classes. Each week, each group rotated from 1 subject of the 16 subjects of PBL to another subject. All of the 16 groups went through all the 16 subjects in the 2013 spring semester. We examined the medical students' satisfaction with each class, based on a rating score collected after each class was completed, using a scale from 0 (the lowest satisfaction) to 100 (the highest satisfaction). We also conducted multivariate linear regression analysis to examine the association between the independent variables and the students' satisfaction.Medical students were more satisfied with the TAF (91.35 ± 7.75) medical humanities PBL classes than APF (90.40 ± 8.42) medical humanities PBL classes (P = 0.01). Moreover, medical students were more satisfied with the clinical medicine-unrelated topics (92.00 ± 7.10) than the clinical medicine-related topics (90.36 ± 7.99) in the medical humanities PBL course (P = 0.01).This medical humanities PBL course, including nonmedical subjects and topics, and nonmedical teaching assistants from the liberal arts as class facilitators, was satisfactory. This pedagogical approach of student-centered, nonmedical topics, nonmedical facilitators, and small groups, which is associated with a deep approach to learning medical humanities, should be highly encouraged.
Tseng, Fen-Yu; Shieh, Jeng-Yi; Kao, Tze-Wah; Wu, Chau-Chung; Chu, Tzong-Shinn; Chen, Yen-Yuan
2016-01-01
Abstract Although medical humanities courses taught by teachers from nonmedical backgrounds are not unusual now, few studies have compared the outcome of medical humanities courses facilitated by physicians to that by teaching assistants majored in the liberal arts. The objectives of this study were to (1) analyze the satisfaction of medical students with medical humanities problem-based learning (PBL) classes facilitated by nonmedical teaching assistants (TAF) majored in the liberal arts, and those facilitated by the attending physicians (APF) and (2) examine the satisfaction of medical students with clinical medicine-related and clinical medicine-unrelated medical humanities PBL classes. A total of 123 medical students, randomly assigned to 16 groups, participated in this study. There were 16 classes in the course: 8 of them were TAF classes; and the others were APF classes. Each week, each group rotated from 1 subject of the 16 subjects of PBL to another subject. All of the 16 groups went through all the 16 subjects in the 2013 spring semester. We examined the medical students’ satisfaction with each class, based on a rating score collected after each class was completed, using a scale from 0 (the lowest satisfaction) to 100 (the highest satisfaction). We also conducted multivariate linear regression analysis to examine the association between the independent variables and the students’ satisfaction. Medical students were more satisfied with the TAF (91.35 ± 7.75) medical humanities PBL classes than APF (90.40 ± 8.42) medical humanities PBL classes (P = 0.01). Moreover, medical students were more satisfied with the clinical medicine-unrelated topics (92.00 ± 7.10) than the clinical medicine-related topics (90.36 ± 7.99) in the medical humanities PBL course (P = 0.01). This medical humanities PBL course, including nonmedical subjects and topics, and nonmedical teaching assistants from the liberal arts as class facilitators, was satisfactory. This pedagogical approach of student-centered, nonmedical topics, nonmedical facilitators, and small groups, which is associated with a deep approach to learning medical humanities, should be highly encouraged. PMID:26871828
Pathwise upper semi-continuity of random pullback attractors along the time axis
NASA Astrophysics Data System (ADS)
Cui, Hongyong; Kloeden, Peter E.; Wu, Fuke
2018-07-01
The pullback attractor of a non-autonomous random dynamical system is a time-indexed family of random sets, typically having the form {At(ṡ) } t ∈ R with each At(ṡ) a random set. This paper is concerned with the nature of such time-dependence. It is shown that the upper semi-continuity of the mapping t ↦At(ω) for each ω fixed has an equivalence relationship with the uniform compactness of the local union ∪s∈IAs(ω) , where I ⊂ R is compact. Applied to a semi-linear degenerate parabolic equation with additive noise and a wave equation with multiplicative noise we show that, in order to prove the above locally uniform compactness and upper semi-continuity, no additional conditions are required, in which sense the two properties appear to be general properties satisfied by a large number of real models.
Global mean first-passage times of random walks on complex networks.
Tejedor, V; Bénichou, O; Voituriez, R
2009-12-01
We present a general framework, applicable to a broad class of random walks on complex networks, which provides a rigorous lower bound for the mean first-passage time of a random walker to a target site averaged over its starting position, the so-called global mean first-passage time (GMFPT). This bound is simply expressed in terms of the equilibrium distribution at the target and implies a minimal scaling of the GMFPT with the network size. We show that this minimal scaling, which can be arbitrarily slow, is realized under the simple condition that the random walk is transient at the target site and independently of the small-world, scale-free, or fractal properties of the network. Last, we put forward that the GMFPT to a specific target is not a representative property of the network since the target averaged GMFPT satisfies much more restrictive bounds.
Regularization of the big bang singularity with random perturbations
NASA Astrophysics Data System (ADS)
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.
Competitive Facility Location with Fuzzy Random Demands
NASA Astrophysics Data System (ADS)
Uno, Takeshi; Katagiri, Hideki; Kato, Kosuke
2010-10-01
This paper proposes a new location problem of competitive facilities, e.g. shops, with uncertainty and vagueness including demands for the facilities in a plane. By representing the demands for facilities as fuzzy random variables, the location problem can be formulated as a fuzzy random programming problem. For solving the fuzzy random programming problem, first the α-level sets for fuzzy numbers are used for transforming it to a stochastic programming problem, and secondly, by using their expectations and variances, it can be reformulated to a deterministic programming problem. After showing that one of their optimal solutions can be found by solving 0-1 programming problems, their solution method is proposed by improving the tabu search algorithm with strategic oscillation. The efficiency of the proposed method is shown by applying it to numerical examples of the facility location problems.
Ising Critical Behavior of Inhomogeneous Curie-Weiss Models and Annealed Random Graphs
NASA Astrophysics Data System (ADS)
Dommers, Sander; Giardinà, Cristian; Giberti, Claudio; van der Hofstad, Remco; Prioriello, Maria Luisa
2016-11-01
We study the critical behavior for inhomogeneous versions of the Curie-Weiss model, where the coupling constant {J_{ij}(β)} for the edge {ij} on the complete graph is given by {J_{ij}(β)=β w_iw_j/( {sum_{kin[N]}w_k})}. We call the product form of these couplings the rank-1 inhomogeneous Curie-Weiss model. This model also arises [with inverse temperature {β} replaced by {sinh(β)} ] from the annealed Ising model on the generalized random graph. We assume that the vertex weights {(w_i)_{iin[N]}} are regular, in the sense that their empirical distribution converges and the second moment converges as well. We identify the critical temperatures and exponents for these models, as well as a non-classical limit theorem for the total spin at the critical point. These depend sensitively on the number of finite moments of the weight distribution. When the fourth moment of the weight distribution converges, then the critical behavior is the same as on the (homogeneous) Curie-Weiss model, so that the inhomogeneity is weak. When the fourth moment of the weights converges to infinity, and the weights satisfy an asymptotic power law with exponent {τ} with {τin(3,5)}, then the critical exponents depend sensitively on {τ}. In addition, at criticality, the total spin {S_N} satisfies that {S_N/N^{(τ-2)/(τ-1)}} converges in law to some limiting random variable whose distribution we explicitly characterize.
Bharadwaj, Lalita; Waldner, Cheryl L.
2018-01-01
ABSTRACT Previous studies have described concerns regarding tap water in Indigenous communities, yet there is little information on participants who report drinking their tap water and being satisfied with its quality. This study undertaken with members of 8 Indigenous communities in Saskatchewan, Canada, and identified factors associated with both the decision to drink tap water at home and being satisfied with its quality. We examined the importance of factors such as individual attributes, experiences, attitudes, household and community-based variables. Less than one-quarter of participants (23.4%) drank tap water and were satisfied with its quality. Individuals who did not boil tap water (odds ratio [OR] = 5.76, 95% confidence interval [CI] = 1.68–19.8), those who did not experience tap water odour (OR = 2.38, 95% CI = 1.26–4.50) and participants living in communities away from urban centres (OR = 2.74, 95% CI = 1.63–4.51) were more likely to drink and be satisfied with their tap water. Concerns about the environment had the most impact on community members aged 55+ years. Those not reporting concerns about environmental problems affecting water (OR = 11.4, 95% CI = 3.10–42.2) were much more likely to drink and be satisfied with their tap water. Programmes to improve water quality, reduce the need for boil water advisories and increase community confidence in the environment could improve tap water satisfaction and consumption. PMID:29697009
van Campen, Cretien; Cardol, Mieke
2009-07-01
People with chronic physical disabilities participate less in both paid and voluntary work and are less satisfied with their lives than people without health problems. Governments and scientists have suggested that participation in employment is the main road to well-being. We analysed national survey data on the participation in work and satisfaction with life, comparing people with a chronic illness and a physical disability (n=603) to people with a chronic illness but without a physical disability (n=1199) and the general population (n=6128) in the Netherlands. The results show that the relationship between happiness and work is different for people with a chronic illness and a physical disability, as compared to the other two populations. Fewer people with a chronic illness and disability were categorized as 'satisfied people with work' (i.e. participating in work and satisfied with their life), while most people belonged to a group of 'satisfied people without work' and, surprisingly, not to the expected group of 'dissatisfied people without work'. In order to explain this exceptional distribution we modelled satisfied participation in work as an outcome of a balance between personal resources and barriers. By means of discriminant regression analysis, we identified the severity of motor disability as the main barrier, and education level and age, as the main resource factors that distinguish between 'satisfied people with work' and others among the group of people with a chronic illness and a physical disability.
2014-01-01
Background As a part of nationwide healthcare reforms, the Chinese government launched web-based appointment systems (WAS) to provide a solution to problems around outpatient appointments and services. These have been in place in all Chinese public tertiary hospitals since 2009. Methods Questionnaires were collected from both patients and doctors in one large tertiary public hospital in Shanghai, China.Data were analyzed to measure their satisfaction and views about the WAS. Results The 1000 outpatients randomly selected for the survey were least satisfied about the waiting time to see a doctor. Even though the WAS provided a much more convenient booking method, only 17% of patients used it. Of the 197 doctors surveyed, over 90% thought it was necessary to provide alternative forms of appointment booking systems for outpatients. However, about 80% of those doctors who were not associated professors would like to provide an ‘on-the-spot’ appointment option, which would lead to longer waits for patients. Conclusions Patients were least satisfied about the waiting times. To effectively reduce appointment-waiting times is therefore an urgent issue. Despite the benefits of using the WAS, most patients still registered via the usual method of queuing, suggesting that hospitals and health service providers should promote and encourage the use of the WAS. Furthermore, Chinese health providers need to help doctors to take others’ opinions or feedback into consideration when treating patients to minimize the gap between patients’ and doctors’ opinions. These findings may provide useful information for both practitioners and regulators, and improve recognition of this efficient and useful booking system, which may have far-reaching and positive implications for China’s ongoing reforms. PMID:24912568
Auditing psychiatric out-patient records.
Pillay, Selena; O'Dwyer, Sarah; McCarthy, Marguerite
2010-01-01
Up-to-date patient records are essential for safe and professional practice. They are an intrinsic component for providing adequate care and ensuring appropriate and systematic treatment 2009 plans. Furthermore, accurate and contemporaneous notes are essential for achieving professional standards from a medico-legal perspective. The study's main aim was to investigate current record-keeping practices by looking at whether out-patient communication pathways to general practitioners, from letter dictation to insertion in the chart, were being satisfied. From current out-patient attendees over six months, 100 charts were chosen randomly, and reviewed. A pro-forma was used to collect data and this information was also checked against electronic records. Of the charts reviewed, 15 per cent had no letter. If one considers that one-month is an acceptable time for letters to be inserted into the chart, then only 11 per cent satisfied this condition. Electronic data were also missing. It is impossible to discern whether letters to GPs were dictated by the out-patient doctor for each patient reviewed. Another limitation was that some multidisciplinary hospital teams have different out-patient note-keeping procedures, which makes some findings difficult to interpret. The review drew attention to current record-keeping discrepancies, highlighting the need for medical record-keeping procedures and polices to be put in place. Also brought to light was the importance of providing a workforce sufficient to meet the out-patient team's administrative needs. An extended audit of other medical record-keeping aspects should be carried out to determine whether problems occur in other areas. The study highlights the importance of establishing agreed policies and procedures for out-patient record keeping and the need to have a checking mechanism to identify system weaknesses.
Energy efficient LED layout optimization for near-uniform illumination
NASA Astrophysics Data System (ADS)
Ali, Ramy E.; Elgala, Hany
2016-09-01
In this paper, we consider the problem of designing energy efficient light emitting diodes (LEDs) layout while satisfying the illumination constraints. Towards this objective, we present a simple approach to the illumination design problem based on the concept of the virtual LED. We formulate a constrained optimization problem for minimizing the power consumption while maintaining a near-uniform illumination throughout the room. By solving the resulting constrained linear program, we obtain the number of required LEDs and the optimal output luminous intensities that achieve the desired illumination constraints.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Klimsiak, Tomasz, E-mail: tomas@mat.umk.pl; Rozkosz, Andrzej, E-mail: rozkosz@mat.umk.pl
In the paper we consider the problem of valuation of American options written on dividend-paying assets whose price dynamics follow the classical multidimensional Black and Scholes model. We provide a general early exercise premium representation formula for options with payoff functions which are convex or satisfy mild regularity assumptions. Examples include index options, spread options, call on max options, put on min options, multiply strike options and power-product options. In the proof of the formula we exploit close connections between the optimal stopping problems associated with valuation of American options, obstacle problems and reflected backward stochastic differential equations.
Relationship between Teachers' Job Satisfaction and Students' Academic Performance
ERIC Educational Resources Information Center
Iqbal, Asif; Aziz, Fakhra; Farooqi, Tahir Khan; Ali, Shabbir
2016-01-01
Problem Statement: An extensive literature on Job satisfaction has shown, teachers who are satisfied with their jobs perform better. Along with various indicators of teachers' job satisfaction, variables such as organizational justice (Nojani, Arjmandnia, Afrooz, & Rajabi, 2012), organizational culture (Hosseinkhanzadeh, Hosseinkhanzadeh,…
Continuous-Time Classical and Quantum Random Walk on Direct Product of Cayley Graphs
NASA Astrophysics Data System (ADS)
Salimi, S.; Jafarizadeh, M. A.
2009-06-01
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 Kn, 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.
Compact Plasma Accelerator for Micropropulsion Applications
NASA Technical Reports Server (NTRS)
Foster, John E.
2001-01-01
There is a need for a low power, light-weight (compact), high specific impulse electric propulsion device to satisfy mission requirements for microsatellite (1 to 20 kg) class missions. Satisfying these requirements entails addressing the general problem of generating a sufficiently dense plasma within a relatively small volume and then accelerating it. In the work presented here, the feasibility of utilizing a magnetic cusp to generate a dense plasma over small length scales of order 1 mm is investigated. This approach could potentially mitigate scaling issues associated with conventional ion thruster plasma containment schemes. Plume and discharge characteristics were documented using a Faraday probe and a retarding potential analyzer.
Moe, Rikke Helene; Grotle, Margreth; Kjeken, Ingvild; Olsen, Inge Christoffer; Mowinckel, Petter; Haavardsholm, Espen A; Hagen, Kåre Birger; Kvien, Tore K; Uhlig, Till
2016-02-01
Osteoarthritis (OA) is one of the leading causes of pain and disability. Given the constraint in the provision of care, there is a need to develop and assess effectiveness of new treatment models. The objective was to compare satisfaction with and effectiveness of a new integrated multidisciplinary outpatient program with usual care in an outpatient clinic for patients with OA. Patients with clinical OA referred to a rheumatology outpatient clinic were randomized to a 3.5-h multidisciplinary group-based educational program followed by individual consultations, or to usual care. The primary outcome was satisfaction with the health service evaluated on a numerical rating scale (0 = extremely unsatisfied, 10 = extremely satisfied) after 4 months. Secondary outcomes included health-related quality of life measures. Of 391 patients, 86.4% (n = 338) were women, and mean age was 61.2 (SD 8.0) years. At 4 months, patients who received integrated multidisciplinary care were significantly more satisfied with the health service compared with controls, with a mean difference of -1.05 (95% CI -1.68 to -0.43, p < 0.001). Among secondary outcomes, only self-efficacy with other symptoms scale (10-100) improved significantly in the multidisciplinary group compared with controls at 4 months (3.59, 95% CI 0.69-6.5, p = 0.02). At 12 months, the Australian/Canadian Hand Osteoarthritis Index pain (0-10) and fatigue scores (0-10) were slightly worse in the multidisciplinary group with differences of 0.38 (95% CI 0.06-0.71, p = 0.02) and 0.55 (95% CI 0.02-1.07, p = 0.04), respectively. Patients receiving an integrated multidisciplinary care model were more satisfied with healthcare than those receiving usual care, whereas there were no clinically relevant improvements in health outcomes.
Katoulis, A C; Alevizou, A; Bozi, E; Makris, M; Zafeiraki, A; Mantas, N; Kousta, F; Mistidou, M; Kanelleas, A; Stavrianeas, N G
2010-07-01
Solar lentigines are common, benign, cosmetically disfiguring lesions. Available physical treatments are effective, but they are costly and carry risks of side-effects. To evaluate the efficacy and safety of a preparation containing undecylenoyl phenylalanine 2% in the topical treatment of solar lentigines. In total, 36 patients with solar lentigines of the hands were randomly assigned to apply the active preparation on one side and the vehicle alone on the other side, twice daily for 12 weeks. Patients were evaluated monthly for efficacy and safety. In all, 30 patients (28 women and 2 men; age range 47-75 years) completed the study. The duration of lesions ranged from 8 months to > 10 years. All patients responded partially on the side of the active treatment. Of the partial responders, 19 (63.3%) had moderate improvement and 11 (36.6%) had marked improvement. Improvement was evident from the first follow-up visit. On the side of the vehicle, 26 remained stable (86.6%) and 4 (13.3%) had partial improvement. There was a significant difference (P < 0.01) in efficacy of the active preparation vs. the vehicle. Using patient assessment ratings, 80% were 'much more satisfied/more satisfied' with the result. The reported side-effects were minor and included erythema and itching or burning on the side of active treatment. Undecylenoyl phenylalanine 2% is a novel depigmenting agent, which possibly acts as an alpha-melanocyte-stimulating hormone antagonist, thus inhibiting melaninogenesis. It achieved a significant lightening of the lesions with minimal side-effects. Most patients were satisfied with the improvement. Undecylenoyl phenylalanine 2% may represent a safe, effective and inexpensive therapeutic alternative for solar lentigines.
Cauchy problem with general discontinuous initial data along a smooth curve for 2-d Euler system
NASA Astrophysics Data System (ADS)
Chen, Shuxing; Li, Dening
2014-09-01
We study the Cauchy problems for the isentropic 2-d Euler system with discontinuous initial data along a smooth curve. All three singularities are present in the solution: shock wave, rarefaction wave and contact discontinuity. We show that the usual restrictive high order compatibility conditions for the initial data are automatically satisfied. The local existence of piecewise smooth solution containing all three waves is established.
A New Time-Space Accurate Scheme for Hyperbolic Problems. 1; Quasi-Explicit Case
NASA Technical Reports Server (NTRS)
Sidilkover, David
1998-01-01
This paper presents a new discretization scheme for hyperbolic systems of conservations laws. It satisfies the TVD property and relies on the new high-resolution mechanism which is compatible with the genuinely multidimensional approach proposed recently. This work can be regarded as a first step towards extending the genuinely multidimensional approach to unsteady problems. Discontinuity capturing capabilities and accuracy of the scheme are verified by a set of numerical tests.
Orthology and paralogy constraints: satisfiability and consistency.
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.
Orthology and paralogy constraints: satisfiability and consistency
2014-01-01
Background 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? Results 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. PMID:25572629
Fourier dimension of random images
NASA Astrophysics Data System (ADS)
Ekström, Fredrik
2016-10-01
Given a compact set of real numbers, a random C^{m + α}-diffeomorphism is constructed such that the image of any measure concentrated on the set and satisfying a certain condition involving a real number s, almost surely has Fourier dimension greater than or equal to s / (m + α). This is used to show that every Borel subset of the real numbers of Hausdorff dimension s is C^{m + α}-equivalent to a set of Fourier dimension greater than or equal to s / (m + α ). In particular every Borel set is diffeomorphic to a Salem set, and the Fourier dimension is not invariant under Cm-diffeomorphisms for any m.
Variational Solutions and Random Dynamical Systems to SPDEs Perturbed by Fractional Gaussian Noise
Zeng, Caibin; Yang, Qigui; Cao, Junfei
2014-01-01
This paper deals with the following type of stochastic partial differential equations (SPDEs) perturbed by an infinite dimensional fractional Brownian motion with a suitable volatility coefficient Φ: dX(t) = A(X(t))dt+Φ(t)dB H(t), where A is a nonlinear operator satisfying some monotonicity conditions. Using the variational approach, we prove the existence and uniqueness of variational solutions to such system. Moreover, we prove that this variational solution generates a random dynamical system. The main results are applied to a general type of nonlinear SPDEs and the stochastic generalized p-Laplacian equation. PMID:24574903
Selection dynamic of Escherichia coli host in M13 combinatorial peptide phage display libraries.
Zanconato, Stefano; Minervini, Giovanni; Poli, Irene; De Lucrezia, Davide
2011-01-01
Phage display relies on an iterative cycle of selection and amplification of random combinatorial libraries to enrich the initial population of those peptides that satisfy a priori chosen criteria. The effectiveness of any phage display protocol depends directly on library amino acid sequence diversity and the strength of the selection procedure. In this study we monitored the dynamics of the selective pressure exerted by the host organism on a random peptide library in the absence of any additional selection pressure. The results indicate that sequence censorship exerted by Escherichia coli dramatically reduces library diversity and can significantly impair phage display effectiveness.
ERIC Educational Resources Information Center
Enders, Craig K.; Peugh, James L.
2004-01-01
Two methods, direct maximum likelihood (ML) and the expectation maximization (EM) algorithm, can be used to obtain ML parameter estimates for structural equation models with missing data (MD). Although the 2 methods frequently produce identical parameter estimates, it may be easier to satisfy missing at random assumptions using EM. However, no…
Local Histograms for Per-Pixel Classification
2012-03-01
few axioms for such models are presented. These axioms are shown to be satisfied using the convergence of random wavelet expansions. The authors of...pathologists can accurately and consistently identify and delineate tissues and their pathologies , it is an expensive and time-consuming task, therefore...Automatic Identification and Delineation of Tissues and Pathologies in H&E Stained Images. PhD Thesis. Carnegie Mellon University, Pittsburgh, PA (September
Quantum vacuum energy in general relativity
NASA Astrophysics Data System (ADS)
Henke, Christian
2018-02-01
The paper deals with the scale discrepancy between the observed vacuum energy in cosmology and the theoretical quantum vacuum energy (cosmological constant problem). Here, we demonstrate that Einstein's equation and an analogy to particle physics leads to the first physical justification of the so-called fine-tuning problem. This fine-tuning could be automatically satisfied with the variable cosmological term Λ (a)=Λ_0+Λ_1 a^{-(4-ɛ)}, 0 < ɛ ≪ 1, where a is the scale factor. As a side effect of our solution of the cosmological constant problem, the dynamical part of the cosmological term generates an attractive force and solves the missing mass problem of dark matter.
Generalized Pattern Search methods for a class of nonsmooth optimization problems with structure
NASA Astrophysics Data System (ADS)
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.
A SAT Based Effective Algorithm for the Directed Hamiltonian Cycle Problem
NASA Astrophysics Data System (ADS)
Jäger, Gerold; Zhang, Weixiong
The Hamiltonian cycle problem (HCP) is an important combinatorial problem with applications in many areas. While thorough theoretical and experimental analyses have been made on the HCP in undirected graphs, little is known for the HCP in directed graphs (DHCP). The contribution of this work is an effective algorithm for the DHCP. Our algorithm explores and exploits the close relationship between the DHCP and the Assignment Problem (AP) and utilizes a technique based on Boolean satisfiability (SAT). By combining effective algorithms for the AP and SAT, our algorithm significantly outperforms previous exact DHCP algorithms including an algorithm based on the award-winning Concorde TSP algorithm.
School/Business Partnerships. Working Paper 3.
ERIC Educational Resources Information Center
Chicago United, IL.
Illinois is considering various approaches to school/business partnerships that will alleviate some of the problems facing America today, especially the need for an educated, trainable, and flexible workforce able to satisfy the demands of a radically altered economic environment. Widespread functional illiteracy, retraining needs, and…
The Commercial Course: Defense et Illustration.
ERIC Educational Resources Information Center
Scavillo, Anthony
The development of commercial foreign language courses by colleges and universities would help to satisfy the need for language enrollments and the expressed need of the international business community for foreign language skills in American business employees. Three major problems inhibit commercial language course development: limited…
Why Employee Motivation Has Declined in America.
ERIC Educational Resources Information Center
Grant, Philip C.
1982-01-01
Examines possible reasons for declining employee motivation: greater instability and diversity of values; more guaranteed rewards; inability of rewards to satisfy emerging needs; disappearing work ethic; reduced costs of failure; rising income and progressive taxation; more group production and problem solving; decreased employee loyalty; less…
Space shuttle program: Lightning protection criteria document
NASA Technical Reports Server (NTRS)
1975-01-01
The lightning environment for space shuttle design is defined and requirements that the design must satisfy to insure protection of the vehicle system from direct and indirect effects of lightning are imposed. Specifications, criteria, and guidelines included provide a practical and logical approach to protection problems.
The Nature and Operation of Training Institutes: A Generic Marketing Plan for Community Colleges.
ERIC Educational Resources Information Center
Vivelo, Frank R.
1991-01-01
Discusses marketing problems and opportunities associated with satisfying demand, product-consumer match, support services, personnel, and personal involvement. Identifies overall marketing and business/financial goals and related objectives. Covers action plans, performance evaluations, curriculum design, advisory committee participation and…
Local Existence of MHD Contact Discontinuities
NASA Astrophysics Data System (ADS)
Morando, Alessandro; Trakhinin, Yuri; Trebeschi, Paola
2018-05-01
We prove the local-in-time existence of solutions with a contact discontinuity of the equations of ideal compressible magnetohydrodynamics (MHD) for two dimensional planar flows provided that the Rayleigh-Taylor sign condition {[partial p/partial N] <0 } on the jump of the normal derivative of the pressure is satisfied at each point of the initial discontinuity. MHD contact discontinuities are characteristic discontinuities with no flow across the discontinuity for which the pressure, the magnetic field and the velocity are continuous whereas the density and the entropy may have a jump. This paper is a natural completion of our previous analysis (Morando et al. in J Differ Equ 258:2531-2571, 2015) where the well-posedness in Sobolev spaces of the linearized problem was proved under the Rayleigh-Taylor sign condition satisfied at each point of the unperturbed discontinuity. The proof of the resolution of the nonlinear problem given in the present paper follows from a suitable tame a priori estimate in Sobolev spaces for the linearized equations and a Nash-Moser iteration.
Sheng, Li; Wang, Zidong; Zou, Lei; Alsaadi, Fuad E
2017-10-01
In this paper, the event-based finite-horizon H ∞ state estimation problem is investigated for a class of discrete time-varying stochastic dynamical networks with state- and disturbance-dependent noises [also called (x,v) -dependent noises]. An event-triggered scheme is proposed to decrease the frequency of the data transmission between the sensors and the estimator, where the signal is transmitted only when certain conditions are satisfied. The purpose of the problem addressed is to design a time-varying state estimator in order to estimate the network states through available output measurements. By employing the completing-the-square technique and the stochastic analysis approach, sufficient conditions are established to ensure that the error dynamics of the state estimation satisfies a prescribed H ∞ performance constraint over a finite horizon. The desired estimator parameters can be designed via solving coupled backward recursive Riccati difference equations. Finally, a numerical example is exploited to demonstrate the effectiveness of the developed state estimation scheme.
Three dimensional elements with Lagrange multipliers for the modified couple stress theory
NASA Astrophysics Data System (ADS)
Kwon, Young-Rok; Lee, Byung-Chai
2018-07-01
Three dimensional mixed elements for the modified couple stress theory are proposed. The C1 continuity for the displacement field, which is required because of the curvature term in the variational form of the theory, is satisfied weakly by introducing a supplementary rotation as an independent variable and constraining the relation between the rotation and the displacement with a Lagrange multiplier vector. An additional constraint about the deviatoric curvature is also considered for three dimensional problems. Weak forms with one constraint and two constraints are derived, and four elements satisfying convergence criteria are developed by applying different approximations to each field of independent variables. The elements pass a [InlineEquation not available: see fulltext.] patch test for three dimensional problems. Numerical examples show that the additional constraint could be considered essential for the three dimensional elements, and one of the elements is recommended for practical applications via the comparison of the performances of the elements. In addition, all the proposed elements can represent the size effect well.
Voegtlin, T; Verschure, P F
1999-01-01
This paper argues for the development of synthetic approaches towards the study of brain and behavior as a complement to the more traditional empirical mode of research. As an example we present our own work on learning and problem solving which relates to the behavioral paradigms of classical and operant conditioning. We define the concept of learning in the context of behavior and lay out the basic methodological requirements a model needs to satisfy, which includes evaluations using robots. In addition, we define a number of design principles neuronal models should obey to be considered relevant. We present in detail the construction of a neural model of short- and long-term memory which can be applied to an artificial behaving system. The presented model (DAC4) provides a novel self-consistent implementation of these processes, which satisfies our principles. This model will be interpreted towards the present understanding of the neuronal substrate of memory.
A novel artificial intelligence method for weekly dietary menu planning.
Gaál, B; Vassányi, I; Kozmann, G
2005-01-01
Menu planning is an important part of personalized lifestyle counseling. The paper describes the results of an automated menu generator (MenuGene) of the web-based lifestyle counseling system Cordelia that provides personalized advice to prevent cardiovascular diseases. The menu generator uses genetic algorithms to prepare weekly menus for web users. The objectives are derived from personal medical data collected via forms in Cordelia, combined with general nutritional guidelines. The weekly menu is modeled as a multilevel structure. Results show that the genetic algorithm-based method succeeds in planning dietary menus that satisfy strict numerical constraints on every nutritional level (meal, daily basis, weekly basis). The rule-based assessment proved capable of manipulating the mean occurrence of the nutritional components thus providing a method for adjusting the variety and harmony of the menu plans. By splitting the problem into well determined sub-problems, weekly menu plans that satisfy nutritional constraints and have well assorted components can be generated with the same method that is for daily and meal plan generation.
Teamwork in perioperative nursing. Understanding team development, effectiveness, evaluation.
Farley, M J
1991-03-01
Teams are an essential part of perioperative nursing practice. Nurses who have a knowledge of teamwork and experience in working on teams have a greater understanding of the processes and problems involved as teams develop from new, immature teams to those that are mature and effective. This understanding will assist nurses in helping their teams achieve a higher level of productivity, and members will be more satisfied with team efforts. Team development progresses through several stages. Each stage has certain characteristics and desired outcomes. At each stage, team members and leaders have certain responsibilities. Team growth does not take place automatically and inevitably, but as a consequence of conscious and unconscious efforts of its leader and members to solve problems and satisfy needs. Building and maintaining a team is certainly work, but work that brings a great deal of satisfaction and feelings of pride in accomplishment. According to I Tenzer, RN, MS, teamwork "is not a panacea; it is a viable approach to developing a hospital's most valuable resource--people."
Softened gravity and the extension of the standard model up to infinite energy
NASA Astrophysics Data System (ADS)
Giudice, Gian F.; Isidori, Gino; Salvio, Alberto; Strumia, Alessandro
2015-02-01
Attempts to solve naturalness by having the weak scale as the only breaking of classical scale invariance have to deal with two severe difficulties: gravity and the absence of Landau poles. We show that solutions to the first problem require premature modifications of gravity at scales no larger than 1011 GeV, while the second problem calls for many new particles at the weak scale. To build models that fulfill these properties, we classify 4- dimensional Quantum Field Theories that satisfy Total Asymptotic Freedom (TAF): the theory holds up to infinite energy, where all coupling constants flow to zero. We develop a technique to identify such theories and determine their low-energy predictions. Since the Standard Model turns out to be asymptotically free only under the unphysical conditions g 1 = 0, M t = 186 GeV, M τ = 0, M h = 163 GeV, we explore some of its weak-scale extensions that satisfy the requirements for TAF.
Juneja, Monica; Jain, Rahul; Singhal, Swati; Mishra, Devendra
2012-09-01
To identify the problems faced by parents of children with developmental disabilities in availing rehabilitative services and to find their satisfaction level. This study was carried out at a Child Development Clinic (CDC) located in Northern India. Children with developmental disabilities, who were availing services at CDC for at least last 3 mo and had at least 3 follow-up visits, were enrolled. A questionnaire pertaining to the socio-demographic profile, problems faced in availing services and satisfaction level was filled by the parents of the enrolled children. During the study period, 161 parents filled the questionnaire. 77.6% had some problems in getting the services, the major being difficulty in commuting (50%) and financial constraint (21.7%). More than 80% parents use public transport to reach CDC with 19% travelling more than 50 Km. 29.8% had difficulty in bringing their child to the clinic, either due to severe behavioral problems or physical disability. However, majority of the families were well satisfied with the services as 95% of them graded their satisfaction level at 3 or more on the scale of 0-5. Parents of children with developmental disabilities face many problems in getting rehabilitative services. They travel long distances, face hardships in carrying their child, and lose their day's earnings, apart from spending time and money for their child's therapy. However, most of the parents are well satisfied with the services.
Expected Fitness Gains of Randomized Search Heuristics for the Traveling Salesperson Problem.
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.
Operator Spreading in Random Unitary Circuits
NASA Astrophysics Data System (ADS)
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 performed exactly. We also use this mapping to give exact results for entanglement growth in 1 +1 D circuits.
[Hygienic aspects of animal carcass disposal].
Bulling, E
1983-09-01
Summarising, it can be stated that the disposal of carcases primarily represents a problem of epidemic hygiene but it also concerns fodder and food hygiene as well as the hygiene of waste water and air purity. Factories under the obligation to satisfy the sanitary demands mentioned and ensure low-cost operation at the same time, are occasionally confronted with great difficulties. In view of the present upward trend of the energy costs, these problems will not become less.
Direct and Inverse Scattering Problem Associated with the Elliptic Sinh-Gordon Equation
1989-11-14
the simple matter of an ambiguity in the quantization of two dimensional Hamiltonian systems, a problem that is easily handled. Our notation is as...siderable evidence has been found in support of a dark- matter fluctuation equations on a background satisfying an expansion hypothesis: suppose the... matter that does porate the case in which one of the fluids is a photon fluid. Of not interact directly with ordinary matter and in particular with
NASA Technical Reports Server (NTRS)
Lyusternik, L. A.
1980-01-01
The mathematics involved in numerically solving for the plane boundary value of the Laplace equation by the grid method is developed. The approximate solution of a boundary value problem for the domain of the Laplace equation by the grid method consists of finding u at the grid corner which satisfies the equation at the internal corners (u=Du) and certain boundary value conditions at the boundary corners.
Self-consistent calculation of the Sommerfeld enhancement
Blum, Kfir; Sato, Ryosuke; Slatyer, Tracy R.
2016-06-08
A calculation of the Sommerfeld enhancement is presented and applied to the problem of s-wave non-relativistic dark matter annihilation. The difference from previous computations in the literature is that the effect of the underlying short-range scattering process is consistently included together with the long-range force in the effective QM Schrödinger problem. Our procedure satisfies partial-wave unitarity where previous calculations fail. We provide analytic results for some potentials of phenomenological relevance.
New periodic solutions for some planar N + 3-body problems with Newtonian potentials
NASA Astrophysics Data System (ADS)
Yuan, Pengfei; Zhang, Shiqing
2018-03-01
For some planar Newtonian N + 3-body problems, we use variational minimization methods to prove the existence of new periodic solutions satisfying that N bodies chase each other on a curve, and the other 3 bodies chase each other on another curve. From the definition of orbit spaces in our paper, we can find that they are new solutions which are also different from all the examples of Ferrario and Terracini (2004).
The Norwegian Polio Study 1994: a nation-wide survey of problems in long-standing poliomyelitis.
Wekre, L L; Stanghelle, J K; Lobben, B; Oyhaugen, S
1998-04-01
'The Norwegian Polio Study 1994' was performed to make a nation-wide survey of the medical and social situation, and of the needs of anterior poliomyelitis (polio). A questionnaire, consisting of 133 questions with sub-questions, was sent to a total of 2392 polio victims, most of them registered in 'The National Society of Polio Victims' in Norway. 1449 persons (61%) answered. Sixty-six per cent were between 45 and 64 years of age, 25% were above 64 years and 9% were under 45 years. When specifying new health problems, 85% stated that they had experienced increased weakness in muscles affected by polio, while 58% had experienced increased weakness in previous non-affected muscles. Other health problems related to polio were fatigue during exercise (80%), general fatigue (57%), joint pain (58%), muscular pain (58%) and cold intolerance (62%). The participants indicated an increasing need of aids, but 80% were still independent of help from others and 57% were still employed, fully or part time. Only 17% were satisfied with the public health services for polio survivors, while 67% of those who had undergone comprehensive examination at some central hospital were satisfied. This study indicates an obvious need of building up expertise in multidisciplinary evaluation and treatment of post polio problems in countries where acute polio has been eliminated.
Ideas for Medical Education: The Quarterly Profile Examination.
ERIC Educational Resources Information Center
Arnold, Louise; Willoughby, T. Lee
1990-01-01
The school of medicine of the University of Missouri--Kansas City developed the Quarterly Profile Examination, a schoolwide, longitudinal comprehensive examination of knowledge acquisition and retention, to satisfy internal and external requirements for assessment. The system is seen as effective in fostering problem-based and independent learning…
Hierarchical Motion Planning for Autonomous Aerial and Terrestrial Vehicles
NASA Astrophysics Data System (ADS)
Cowlagi, Raghvendra V.
Autonomous mobile robots---both aerial and terrestrial vehicles---have gained immense importance due to the broad spectrum of their potential military and civilian applications. One of the indispensable requirements for the autonomy of a mobile vehicle is the vehicle's capability of planning and executing its motion, that is, finding appropriate control inputs for the vehicle such that the resulting vehicle motion satisfies the requirements of the vehicular task. The motion planning and control problem is inherently complex because it involves two disparate sub-problems: (1) satisfaction of the vehicular task requirements, which requires tools from combinatorics and/or formal methods, and (2) design of the vehicle control laws, which requires tools from dynamical systems and control theory. Accordingly, this problem is usually decomposed and solved over two levels of hierarchy. The higher level, called the geometric path planning level, finds a geometric path that satisfies the vehicular task requirements, e.g., obstacle avoidance. The lower level, called the trajectory planning level, involves sufficient smoothening of this geometric path followed by a suitable time parametrization to obtain a reference trajectory for the vehicle. Although simple and efficient, such hierarchical decomposition suffers a serious drawback: the geometric path planner has no information of the kinematical and dynamical constraints of the vehicle. Consequently, the geometric planner may produce paths that the trajectory planner cannot transform into a feasible reference trajectory. Two main ideas appear in the literature to remedy this problem: (a) randomized sampling-based planning, which eliminates the geometric planner altogether by planning in the vehicle state space, and (b) geometric planning supported by feedback control laws. The former class of methods suffer from a lack of optimality of the resultant trajectory, while the latter class of methods makes a restrictive assumption concerning the vehicle kinematical model. We propose a hierarchical motion planning framework based on a novel mode of interaction between these two levels of planning. This interaction rests on the solution of a special shortest-path problem on graphs, namely, one using costs defined on multiple edge transitions in the path instead of the usual single edge transition costs. These costs are provided by a local trajectory generation algorithm, which we implement using model predictive control and the concept of effective target sets for simplifying the non-convex constraints involved in the problem. The proposed motion planner ensures "consistency" between the two levels of planning, i.e., a guarantee that the higher level geometric path is always associated with a kinematically and dynamically feasible trajectory. The main contributions of this thesis are: 1. A motion planning framework based on history-dependent costs (H-costs) in cell decomposition graphs for incorporating vehicle dynamical constraints: this framework offers distinct advantages in comparison with the competing approaches of discretization of the state space, of randomized sampling-based motion planning, and of local feedback-based, decoupled hierarchical motion planning, 2. An efficient and flexible algorithm for finding optimal H-cost paths, 3. A precise and general formulation of a local trajectory problem (the tile motion planning problem) that allows independent development of the discrete planner and the trajectory planner, while maintaining "compatibility" between the two planners, 4. A local trajectory generation algorithm using mpc, and the application of the concept of effective target sets for a significant simplification of the local trajectory generation problem, 5. The geometric analysis of curvature-bounded traversal of rectangular channels, leading to less conservative results in comparison with a result reported in the literature, and also to the efficient construction of effective target sets for the solution of the tile motion planning problem, 6. A wavelet-based multi-resolution path planning scheme, and a proof of completeness of the proposed scheme: such proofs are altogether absent from other works on multi-resolution path planning, 7. A technique for extracting all information about cells---namely, the locations, the sizes, and the associated image intensities---directly from the set of significant detail coefficients considered for path planning at a given iteration, and 8. The extension of the multi-resolution path planning scheme to include vehicle dynamical constraints using the aforementioned history-dependent costs approach. The future work includes an implementation of the proposed framework involving a discrete planner that solves classical planning problems more general than the single-query path planning problem considered thus far, and involving trajectory generation schemes for realistic vehicle dynamical models such as the bicycle model.
[Transsexuals' life satisfaction after gender transformation operations].
Zimmermann, A; Zimmer, R; Kovacs, L; Einödshofer, S; Herschbach, P; Henrich, G; Tunner, W; Biemer, E; Papadopulos, N A
2006-05-01
More and more frequently, the registration of life satisfaction is being used to evaluate different medical treatments. So far, there have been only few such surveys on transsexuals (TS). Therefore, the aim of this study was to evaluate the general and the health-related life satisfaction of transsexuals after gender transformation operations. Forty patients took part in this German cross-sectional study. The Questions on Life Satisfaction Module (FLZ) and free questions on different aspects of the new gender identity were used as measuring instruments. Of the TS studied, 85-95% were "very satisfied" or "satisfied" with the results of their gender transformation operation in respect to gender identity. The TS were significantly less satisfied (P>0.001) in overall "general life satisfaction" than the general population. In overall FLZ scores for "health-related life satisfaction", no differences were seen. These data indicate a discrepancy between subjective satisfaction with new gender identity and current life situation, and they identify problems with life satisfaction.
Predictors of Job Satisfaction in Dental Professionals of the Bosnia and Herzegovina Federation.
Muhic, Edin; Plancak, Darije; Lajnert, Vlatka; Muhic, Asja
2016-09-01
Working in a healthy work environment is the ultimate goal of every employee. Dentistry is a stressful career, and the reasons for dissatisfaction are numerous. The aim of this study was to determine the factors of work satisfaction in dental professionals of the Bosnia and Herzegovina Federation. A total of 134 dental professionals selected randomly from the Registry of Dental Chamber of Bosnia and Herzegovina Federation were included in the study. All of them filled out the Demographic Questionnaire and Job Satisfaction Scale (JSS). An increase in the influence of work on the quality of life as well as an increase in its frequency results in leaving the job and significantly reducing the overall job satisfaction. General dental practitioners are significantly more satisfied as compared with specialists. Significant predictors of the job satisfaction are employment status, type of the practice, and availability of dental assistants. General dental practitioners with a dental assistant employed at a private practice are more likely to be satisfied with their jobs. Employment status, practice type and availability of dental assistants are significant predictors of job satisfaction. General dental practitioners working in a private practice with a dental assistant are most likely to be satisfied.
Salami, A; Walia, T; Bashiri, R
2015-01-01
To evaluate and compare the parental satisfaction among resin composite strip crown, preveneered stainless steel crown (PVSSC) and the newly introduced pre-fabricated primary zirconia crown for restoring maxillary primary incisors. A prospective clinical study on 39 children with carious or traumatized primary maxillary incisors. They were randomly and equally distributed in three groups and received one of the full-coronal restorations. Children were recalled to evaluate and compare parental satisfaction about performance of crowns after one year through a questionnaire. Parents were satisfied with all three tooth colored full-coronal restoration techniques. A significant relationship was found between colour of PVSSC (p=0.003) and durability of resin strip crowns (p=0.009) with the overall parental satisfaction levels. Parents who gave poor ratings in these two variables however rated their overall acceptance levels as being satisfied. Parental overall satisfaction was highest for zirconia primary crowns followed by resin composite strip crowns and lowest satisfaction was reported for pre-veneered SSCs. Parents were least satisfied with durability of resin composite strip crowns and colour of pre-veneered stainless steel crowns. However, this did not affect their overall satisfaction with these crowns.
Parameter identification using a creeping-random-search algorithm
NASA Technical Reports Server (NTRS)
Parrish, R. V.
1971-01-01
A creeping-random-search algorithm is applied to different types of problems in the field of parameter identification. The studies are intended to demonstrate that a random-search algorithm can be applied successfully to these various problems, which often cannot be handled by conventional deterministic methods, and, also, to introduce methods that speed convergence to an extremal of the problem under investigation. Six two-parameter identification problems with analytic solutions are solved, and two application problems are discussed in some detail. Results of the study show that a modified version of the basic creeping-random-search algorithm chosen does speed convergence in comparison with the unmodified version. The results also show that the algorithm can successfully solve problems that contain limits on state or control variables, inequality constraints (both independent and dependent, and linear and nonlinear), or stochastic models.
Stamovlasis, Dimitrios; Tsaparlis, Georgios
2003-07-01
The present study examines the role of limited human channel capacity from a science education perspective. A model of science problem solving has been previously validated by applying concepts and tools of complexity theory (the working memory, random walk method). The method correlated the subjects' rank-order achievement scores in organic-synthesis chemistry problems with the subjects' working memory capacity. In this work, we apply the same nonlinear approach to a different data set, taken from chemical-equilibrium problem solving. In contrast to the organic-synthesis problems, these problems are algorithmic, require numerical calculations, and have a complex logical structure. As a result, these problems cause deviations from the model, and affect the pattern observed with the nonlinear method. In addition to Baddeley's working memory capacity, the Pascual-Leone's mental (M-) capacity is examined by the same random-walk method. As the complexity of the problem increases, the fractal dimension of the working memory random walk demonstrates a sudden drop, while the fractal dimension of the M-capacity random walk decreases in a linear fashion. A review of the basic features of the two capacities and their relation is included. The method and findings have consequences for problem solving not only in chemistry and science education, but also in other disciplines.
Accurate boundary conditions for exterior problems in gas dynamics
NASA Technical Reports Server (NTRS)
Hagstrom, Thomas; Hariharan, S. I.
1988-01-01
The numerical solution of exterior problems is typically accomplished by introducing an artificial, far field boundary and solving the equations on a truncated domain. For hyperbolic systems, boundary conditions at this boundary are often derived by imposing a principle of no reflection. However, waves with spherical symmetry in gas dynamics satisfy equations where incoming and outgoing Riemann variables are coupled. This suggests that natural reflections may be important. A reflecting boundary condition is proposed based on an asymptotic solution of the far field equations. Nonlinear energy estimates are obtained for the truncated problem and numerical experiments presented to validate the theory.
Accurate boundary conditions for exterior problems in gas dynamics
NASA Technical Reports Server (NTRS)
Hagstrom, Thomas; Hariharan, S. I.
1988-01-01
The numerical solution of exterior problems is typically accomplished by introducing an artificial, far-field boundary and solving the equations on a truncated domain. For hyperbolic systems, boundary conditions at this boundary are often derived by imposing a principle of no reflection. However, waves with spherical symmetry in gas dynamics satisfy equations where incoming and outgoing Riemann variables are coupled. This suggests that natural reflections may be important. A reflecting boundary condition is proposed based on an asymptotic solution of the far-field equations. Nonlinear energy estimates are obtained for the truncated problem and numerical experiments presented to validate the theory.
A tool for modeling concurrent real-time computation
NASA Technical Reports Server (NTRS)
Sharma, D. D.; Huang, Shie-Rei; Bhatt, Rahul; Sridharan, N. S.
1990-01-01
Real-time computation is a significant area of research in general, and in AI in particular. The complexity of practical real-time problems demands use of knowledge-based problem solving techniques while satisfying real-time performance constraints. Since the demands of a complex real-time problem cannot be predicted (owing to the dynamic nature of the environment) powerful dynamic resource control techniques are needed to monitor and control the performance. A real-time computation model for a real-time tool, an implementation of the QP-Net simulator on a Symbolics machine, and an implementation on a Butterfly multiprocessor machine are briefly described.
Automatic background updating for video-based vehicle detection
NASA Astrophysics Data System (ADS)
Hu, Chunhai; Li, Dongmei; Liu, Jichuan
2008-03-01
Video-based vehicle detection is one of the most valuable techniques for the Intelligent Transportation System (ITS). The widely used video-based vehicle detection technique is the background subtraction method. The key problem of this method is how to subtract and update the background effectively. In this paper an efficient background updating scheme based on Zone-Distribution for vehicle detection is proposed to resolve the problems caused by sudden camera perturbation, sudden or gradual illumination change and the sleeping person problem. The proposed scheme is robust and fast enough to satisfy the real-time constraints of vehicle detection.
A modified form of conjugate gradient method for unconstrained optimization problems
NASA Astrophysics Data System (ADS)
Ghani, Nur Hamizah Abdul; Rivaie, Mohd.; Mamat, Mustafa
2016-06-01
Conjugate gradient (CG) methods have been recognized as an interesting technique to solve optimization problems, due to the numerical efficiency, simplicity and low memory requirements. In this paper, we propose a new CG method based on the study of Rivaie et al. [7] (Comparative study of conjugate gradient coefficient for unconstrained Optimization, Aus. J. Bas. Appl. Sci. 5(2011) 947-951). Then, we show that our method satisfies sufficient descent condition and converges globally with exact line search. Numerical results show that our proposed method is efficient for given standard test problems, compare to other existing CG methods.
Hybrid Techniques for Optimizing Complex Systems
2009-12-01
Service , Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of...These vectors are randomly generated, and conventional functional simulation propagates signatures to the internal and output nodes. In a typical...instance, if two internal nodes x and y satisfy the property (y = 1) ⇒ (x = 1), where ⇒ denotes “implies”, then y gives information about x whenever y = 1
Design of nucleic acid sequences for DNA computing based on a thermodynamic approach
Tanaka, Fumiaki; Kameda, Atsushi; Yamamoto, Masahito; Ohuchi, Azuma
2005-01-01
We have developed an algorithm for designing multiple sequences of nucleic acids that have a uniform melting temperature between the sequence and its complement and that do not hybridize non-specifically with each other based on the minimum free energy (ΔGmin). Sequences that satisfy these constraints can be utilized in computations, various engineering applications such as microarrays, and nano-fabrications. Our algorithm is a random generate-and-test algorithm: it generates a candidate sequence randomly and tests whether the sequence satisfies the constraints. The novelty of our algorithm is that the filtering method uses a greedy search to calculate ΔGmin. This effectively excludes inappropriate sequences before ΔGmin is calculated, thereby reducing computation time drastically when compared with an algorithm without the filtering. Experimental results in silico showed the superiority of the greedy search over the traditional approach based on the hamming distance. In addition, experimental results in vitro demonstrated that the experimental free energy (ΔGexp) of 126 sequences correlated well with ΔGmin (|R| = 0.90) than with the hamming distance (|R| = 0.80). These results validate the rationality of a thermodynamic approach. We implemented our algorithm in a graphic user interface-based program written in Java. PMID:15701762
Katoulis, Alexander; Alevizou, Antigoni; Soura, Efthymia; Mantas, Nikolaos; Bozi, Evangelia; Gregoriou, Stamatis; Makris, Michalis; Rigopoulos, Dimitris
2014-06-01
Undecylenoyl phenylalanine is a novel skin-lightening agent, probably acting as α-melanocyte-stimulating hormone (α-MSH) and beta-adrenergic receptor (β-ADR) antagonist. The objective of this double-blind randomized comparative study was to evaluate the efficacy and safety of a preparation containing undecylenoyl phenylalanine 2% in the topical treatment of melasma in females. Forty female patients with melasma were randomly assigned to apply either the active preparation or the vehicle alone, twice daily for 12 weeks. Patients were evaluated monthly for efficacy and safety. In all, 37 patients completed the study. Of the 20 patients on active treatment, no one responded completely, but 17 (85%) had partial response. Of them, 11 had moderate improvement and six had marked improvement. Lightening of the lesions was evident from the first follow-up visit at 4 weeks. A statistically significant difference (P < 0.001) in efficacy between the active preparation and the vehicle was documented. Using patient assessment ratings, 80% were extremely satisfied or satisfied with the result. The reported side effects were minor and included erythema and itching or burning at the site of application. Undecylenoyl phenylalanine 2% achieved a significant lightening of melasma lesions with minimal side effects. © 2014 Wiley Periodicals, Inc.
Effect of postgraduate training on job and career satisfaction among health-system pharmacists.
Padiyara, Rosalyn S; Komperda, Kathy E
2010-07-01
The effect of postgraduate training on job and career satisfaction among health-system pharmacists was evaluated. A mail-based questionnaire was sent to a random sample of pharmacist members of the American Society of Health-System Pharmacists. Previously validated questions for job and career satisfaction among pharmacists were utilized. The questionnaire was designed to obtain information regarding general employment, work environment, job satisfaction, career satisfaction, postgraduate training, and demographic characteristics. Pharmacists who had completed either a pharmacy residency or fellowship were classified as having postgraduate training. Questionnaires returned within two months of the original mailing date were included in the analysis. Responses from pharmacists who were retired, employed in a nonpharmacy career, or unemployed were excluded. Data were analyzed using SPSS software. Of the 2499 questionnaires mailed, 36 were undeliverable; 1058 were completed, yielding a response rate of 43%. Of these, 48 were excluded, resulting in 1010 questionnaires suitable for analysis. Approximately 37% of respondents indicated completion of postgraduate training. The most common practice setting was a community, not-for-profit hospital (40.9%). Overall, 90.7% of respondents indicated they were either satisfied or highly satisfied with their current employment. Approximately 45% of pharmacists with postgraduate training indicated they were highly satisfied with their employment, compared with 32.7% of pharmacists without postgraduate training (p < 0.001). Pharmacists who completed postgraduate training were more satisfied with their job than those who did not complete such training.
Using Computer-Generated Random Numbers to Calculate the Lifetime of a Comet.
ERIC Educational Resources Information Center
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.…
A new neural network model for solving random interval linear programming problems.
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.
A boundary element method for Stokes flows with interfaces
NASA Astrophysics Data System (ADS)
Alinovi, Edoardo; Bottaro, Alessandro
2018-03-01
The boundary element method is a widely used and powerful technique to numerically describe multiphase flows with interfaces, satisfying Stokes' approximation. However, low viscosity ratios between immiscible fluids in contact at an interface and large surface tensions may lead to consistency issues as far as mass conservation is concerned. A simple and effective approach is described to ensure mass conservation at all viscosity ratios and capillary numbers within a standard boundary element framework. Benchmark cases are initially considered demonstrating the efficacy of the proposed technique in satisfying mass conservation, comparing with approaches and other solutions present in the literature. The methodology developed is finally applied to the problem of slippage over superhydrophobic surfaces.
On the packing measure of the Sierpinski gasket
NASA Astrophysics Data System (ADS)
Llorente, Marta; Mera, M. Eugenia; Morán, Manuel
2018-06-01
We show that the s-dimensional packing measure P s (S) of the Sierpinski gasket S, where is the similarity dimension of S, satisfies . The formula presented in theorem 6 enables the achievement of the above measure bounds for this non-totally disconnected set as it shows that the symmetries of the Sierpinski gasket can be exploited to simplify the density characterization of P s obtained in Morán (2005 Nonlinearity 18 559–70) for self-similar sets satisfying the so-called open set condition. Thanks to the reduction obtained in theorem 6 we are able to handle the problem of computability of P s (S) with a suitable algorithm.
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 < 0.05). 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.
Sturkenboom, Ingrid H; Graff, Maud J; Borm, George F; Veenhuizen, Yvonne; Bloem, Bastiaan R; Munneke, Marten; Nijhuis-van der Sanden, Maria W
2013-02-01
To evaluate the feasibility of a randomized controlled trial including process and potential impact of occupational therapy in Parkinson's disease. Process and outcome were quantitatively and qualitatively evaluated in an exploratory multicentre, two-armed randomized controlled trial at three months. Forty-three community-dwelling patients with Parkinson's disease and difficulties in daily activities, their primary caregivers and seven occupational therapists. Ten weeks of home-based occupational therapy according to the Dutch guidelines of occupational therapy in Parkinson's disease versus no occupational therapy in the control group. Process evaluation measured accrual, drop-out, intervention delivery and protocol adherence. Primary outcome measures of patients assessed daily functioning: Canadian Occupational Performance Measure (COPM) and Assessment of Motor and Process Skills. Primary outcome for caregivers was caregiver burden: Zarit Burden Inventory. Participants' perspectives of the intervention were explored using questionnaires and in-depth interviews. Inclusion was 23% (43/189), drop-out 7% (3/43) and unblinding of assessors 33% (13/40). Full intervention protocol adherence was 74% (20/27), but only 60% (71/119) of baseline Canadian Occupational Performance Measure priorities were addressed in the intervention. The outcome measures revealed negligible to small effects in favour of the intervention group. Almost all patients and caregivers of the intervention group were satisfied with the results. They perceived: 'more grip on the situation' and used 'practical advices that make life easier'. Therapists were satisfied, but wished for a longer intervention period. The positive perceived impact of occupational therapy warrants a large-scale trial. Adaptations in instructions and training are needed to use the Canadian Occupational Performance Measure as primary outcome measure.
NASA Astrophysics Data System (ADS)
Han, Xiaobao; Li, Huacong; Jia, Qiusheng
2017-12-01
For dynamic decoupling of polynomial linear parameter varying(PLPV) system, a robust dominance pre-compensator design method is given. The parameterized precompensator design problem is converted into an optimal problem constrained with parameterized linear matrix inequalities(PLMI) by using the conception of parameterized Lyapunov function(PLF). To solve the PLMI constrained optimal problem, the precompensator design problem is reduced into a normal convex optimization problem with normal linear matrix inequalities (LMI) constraints on a new constructed convex polyhedron. Moreover, a parameter scheduling pre-compensator is achieved, which satisfies robust performance and decoupling performances. Finally, the feasibility and validity of the robust diagonal dominance pre-compensator design method are verified by the numerical simulation on a turbofan engine PLPV model.
Molecular computation: RNA solutions to chess problems.
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.
NASA Astrophysics Data System (ADS)
Voloshinov, V. V.
2018-03-01
In computations related to mathematical programming problems, one often has to consider approximate, rather than exact, solutions satisfying the constraints of the problem and the optimality criterion with a certain error. For determining stopping rules for iterative procedures, in the stability analysis of solutions with respect to errors in the initial data, etc., a justified characteristic of such solutions that is independent of the numerical method used to obtain them is needed. A necessary δ-optimality condition in the smooth mathematical programming problem that generalizes the Karush-Kuhn-Tucker theorem for the case of approximate solutions is obtained. The Lagrange multipliers corresponding to the approximate solution are determined by solving an approximating quadratic programming problem.
Fast Algorithms for Structured Least Squares and Total Least Squares Problems
Kalsi, Anoop; O’Leary, Dianne P.
2006-01-01
We consider the problem of solving least squares problems involving a matrix M of small displacement rank with respect to two matrices Z1 and Z2. We develop formulas for the generators of the matrix M HM in terms of the generators of M and show that the Cholesky factorization of the matrix M HM can be computed quickly if Z1 is close to unitary and Z2 is triangular and nilpotent. These conditions are satisfied for several classes of matrices, including Toeplitz, block Toeplitz, Hankel, and block Hankel, and for matrices whose blocks have such structure. Fast Cholesky factorization enables fast solution of least squares problems, total least squares problems, and regularized total least squares problems involving these classes of matrices. PMID:27274922
Fast Algorithms for Structured Least Squares and Total Least Squares Problems.
Kalsi, Anoop; O'Leary, Dianne P
2006-01-01
We consider the problem of solving least squares problems involving a matrix M of small displacement rank with respect to two matrices Z 1 and Z 2. We develop formulas for the generators of the matrix M (H) M in terms of the generators of M and show that the Cholesky factorization of the matrix M (H) M can be computed quickly if Z 1 is close to unitary and Z 2 is triangular and nilpotent. These conditions are satisfied for several classes of matrices, including Toeplitz, block Toeplitz, Hankel, and block Hankel, and for matrices whose blocks have such structure. Fast Cholesky factorization enables fast solution of least squares problems, total least squares problems, and regularized total least squares problems involving these classes of matrices.
Strategic Arguments and Tactical Battles over Federal Information Policy.
ERIC Educational Resources Information Center
Sherwood, Diane E.
1990-01-01
Examines public agency attempts to disseminate information in ways that satisfy constituencies, Office of Management and Budget (OMB), and the private sector. The Securities and Exchange Commission's release of EDGAR, the Patent and Trademark Office's recent lawsuit, and Department of Defense problems with Fedlog are cited. Statements and policy…
ERIC Educational Resources Information Center
Danielsen, Reidar
Skilled labor has always been difficult to recruit, and in a tight labor market unskilled, low-paying jobs with low status are also difficult to fill. Recruitment from outside seems necessary to satisfy demands, but migration creates at least as many problems as it solves. The consumption of theoretical training through the university level (a…
Taking the Heat off the School Lunchroom.
ERIC Educational Resources Information Center
Lutz, Raymond P.; And Others
The application of operations research techniques to a public school system's lunch program suggests a possible solution to the problem of rapidly increasing program costs. A computer-assisted menu planner was developed which generated a monthly set of menus satisfying nutritional and Federal standards, and food demand cycles. When compared to the…
Domestic Disasters and Geospatial Technology for the Defense Logistics Agency
2014-12-01
total distance traveled and satisfy all fuel demands. This report used the Vehicle Routing Problem (VRP) Spreadsheet Solver, developed by Erdogan ...Security Affairs, 2(2), 5–10. Erdogan , G. (2013). VRP spreadsheet solver. Retrieved from VeRoLog: EURO Working Group on Vehicle Routing and Logistics
ERIC Educational Resources Information Center
Willingham, Daniel
2014-01-01
A connection between creativity and curiosity may seem self evident, and, indeed, psychologists and philosophers have long held that creativity and curiosity are related. It seems logical enough. One can imagine that the typical individual is satisfied by the usual solution to a problem or the usual way to conceptualize a situation, but the…
Culture vs. Technology: Mass Media Policy of the Netherlands Attempts a Balance.
ERIC Educational Resources Information Center
Heuterman, Thomas H.; Rennen, Toon
Telecommunications policy makers in Western Europe face the dilema of satisfying public demand for a wider range of television viewing alternatives without sacrificing national cultural integrity. The Dutch Parliament addressed this problem in 1984, 1985, and 1986 as it approved steps to implement the "Medianota," the comprehensive…
Storage Optimization of Educational System Data
ERIC Educational Resources Information Center
Boja, Catalin
2006-01-01
There are described methods used to minimize data files dimension. There are defined indicators for measuring size of files and databases. The storage optimization process is based on selecting from a multitude of data storage models the one that satisfies the propose problem objective, maximization or minimization of the optimum criterion that is…
Language Management in the Czech Republic
ERIC Educational Resources Information Center
Neustupny, J. V.; Nekvapil, Jiri
2003-01-01
This monograph, based on the Language Management model, provides information on both the "simple" (discourse-based) and "organised" modes of attention to language problems in the Czech Republic. This includes but is not limited to the language policy of the State. This approach does not satisfy itself with discussing problems…
Improving the Attractiveness of the K-12 Teaching Profession in California.
ERIC Educational Resources Information Center
Smith, Sandra; And Others
This publication analyzes the current status of the teaching profession in California, emphasizing what makes it attractive and satisfying or discouraging to teachers. Important trends in public attitudes about the teaching profession are explored, as well as teachers' perspectives on recruitment and retention. Among the serious problems noted…
Astronomical Catalogues - Definition Elements and Afterlife
NASA Astrophysics Data System (ADS)
Jaschek, C.
1984-09-01
Based on a look at the different meanings of the term catalogue (or catalog), a definition is proposed. In an analysis of the main elements, a number of requirements that catalogues should satisfy are pointed out. A section is devoted to problems connected with computer-readable versions of printed catalogues.
An Interactive Diagnosis Approach for Supporting Clinical Nursing Courses
ERIC Educational Resources Information Center
Wei, Chun-Wang; Lin, Yi-Chun; Lin, Yen-Ting
2016-01-01
Clinical resources in nursing schools are always insufficient for satisfying the practice requirements of each student at the same time during a formal course session. Although several studies have applied information and communication technology to develop computer-based learning tools for addressing this problem, most of these developments lack…
The Agile Approach with Doctoral Dissertation Supervision
ERIC Educational Resources Information Center
Tengberg, Lars Göran Wallgren
2015-01-01
Several research findings conclude that many doctoral students fail to complete their studies within the allowable time frame, in part because of problems related to the research and supervision process. Surveys show that most doctoral students are generally satisfied with their dissertation supervision. However, these surveys also reveal some…
NASA Astrophysics Data System (ADS)
Hasuike, Takashi; Katagiri, Hideki
2010-10-01
This paper focuses on the proposition of a portfolio selection problem considering an investor's subjectivity and the sensitivity analysis for the change of subjectivity. Since this proposed problem is formulated as a random fuzzy programming problem due to both randomness and subjectivity presented by fuzzy numbers, it is not well-defined. Therefore, introducing Sharpe ratio which is one of important performance measures of portfolio models, the main problem is transformed into the standard fuzzy programming problem. Furthermore, using the sensitivity analysis for fuzziness, the analytical optimal portfolio with the sensitivity factor is obtained.
ERIC Educational Resources Information Center
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…
Stochastic reduced order models for inverse problems under uncertainty
Warner, James E.; Aquino, Wilkins; Grigoriu, Mircea D.
2014-01-01
This work presents a novel methodology for solving inverse problems under uncertainty using stochastic reduced order models (SROMs). Given statistical information about an observed state variable in a system, unknown parameters are estimated probabilistically through the solution of a model-constrained, stochastic optimization problem. The point of departure and crux of the proposed framework is the representation of a random quantity using a SROM - a low dimensional, discrete approximation to a continuous random element that permits e cient and non-intrusive stochastic computations. Characterizing the uncertainties with SROMs transforms the stochastic optimization problem into a deterministic one. The non-intrusive nature of SROMs facilitates e cient gradient computations for random vector unknowns and relies entirely on calls to existing deterministic solvers. Furthermore, the method is naturally extended to handle multiple sources of uncertainty in cases where state variable data, system parameters, and boundary conditions are all considered random. The new and widely-applicable SROM framework is formulated for a general stochastic optimization problem in terms of an abstract objective function and constraining model. For demonstration purposes, however, we study its performance in the specific case of inverse identification of random material parameters in elastodynamics. We demonstrate the ability to efficiently recover random shear moduli given material displacement statistics as input data. We also show that the approach remains effective for the case where the loading in the problem is random as well. PMID:25558115
Well-posedness of nonlocal parabolic differential problems with dependent operators.
Ashyralyev, Allaberen; Hanalyev, Asker
2014-01-01
The nonlocal boundary value problem for the parabolic differential equation v'(t) + A(t)v(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 C 0 (β,γ) (E α-β ) of all E α-β -valued continuous functions φ(t) on [0, T] satisfying a Hölder condition with a weight (t + τ)(γ). 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.
A Modified Artificial Bee Colony Algorithm Application for Economic Environmental Dispatch
NASA Astrophysics Data System (ADS)
Tarafdar Hagh, M.; Baghban Orandi, Omid
2018-03-01
In conventional fossil-fuel power systems, the economic environmental dispatch (EED) problem is a major problem that optimally determines the output power of generating units in a way that cost of total production and emission level be minimized simultaneously, and at the same time all the constraints of units and system are satisfied properly. To solve EED problem which is a non-convex optimization problem, a modified artificial bee colony (MABC) algorithm is proposed in this paper. This algorithm by implementing weighted sum method is applied on two test systems, and eventually, obtained results are compared with other reported results. Comparison of results confirms superiority and efficiency of proposed method clearly.
A semi-implicit level set method for multiphase flows and fluid-structure interaction problems
NASA Astrophysics Data System (ADS)
Cottet, Georges-Henri; Maitre, Emmanuel
2016-06-01
In this paper we present a novel semi-implicit time-discretization of the level set method introduced in [8] for fluid-structure interaction problems. The idea stems from a linear stability analysis derived on a simplified one-dimensional problem. The semi-implicit scheme relies on a simple filter operating as a pre-processing on the level set function. It applies to multiphase flows driven by surface tension as well as to fluid-structure interaction problems. The semi-implicit scheme avoids the stability constraints that explicit scheme need to satisfy and reduces significantly the computational cost. It is validated through comparisons with the original explicit scheme and refinement studies on two-dimensional benchmarks.
Connectivity as an alternative to boundary integral equations: Construction of bases
Herrera, Ismael; Sabina, Federico J.
1978-01-01
In previous papers Herrera developed a theory of connectivity that is applicable to the problem of connecting solutions defined in different regions, which occurs when solving partial differential equations and many problems of mechanics. In this paper we explain how complete connectivity conditions can be used to replace boundary integral equations in many situations. We show that completeness is satisfied not only in steady-state problems such as potential, reduced wave equation and static and quasi-static elasticity, but also in time-dependent problems such as heat and wave equations and dynamical elasticity. A method to obtain bases of connectivity conditions, which are independent of the regions considered, is also presented. PMID:16592522
Minimal Time Problem with Impulsive Controls
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kunisch, Karl, E-mail: karl.kunisch@uni-graz.at; Rao, Zhiping, E-mail: zhiping.rao@ricam.oeaw.ac.at
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.
Geometry of quantum state manifolds generated by the Lie algebra operators
NASA Astrophysics Data System (ADS)
Kuzmak, A. R.
2018-03-01
The Fubini-Study metric of quantum state manifold generated by the operators which satisfy the Heisenberg Lie algebra is calculated. The similar problem is studied for the manifold generated by the so(3) Lie algebra operators. Using these results, we calculate the Fubini-Study metrics of state manifolds generated by the position and momentum operators. Also the metrics of quantum state manifolds generated by some spin systems are obtained. Finally, we generalize this problem for operators of an arbitrary Lie algebra.
Convection Regularization of High Wavenumbers in Turbulence ANS Shocks
2011-07-31
dynamics of particles that adhere to one another upon collision and has been studied as a simple cosmological model for describing the nonlinear formation of...solution we mean a solution to the Cauchy problem in the following sense. Definition 5.1. A function u : R × [0, T ] 7→ RN is a weak solution of the...step 2 the limit function in the α → 0 limit is shown to satisfy the definition of a weak solution for the Cauchy problem. Without loss of generality
Runyan, Christine N; Fonseca, Vincent P; Meyer, John G; Oordt, Mark S; Talcott, G Wayne
2003-01-01
Mental health disorders are one of the most substantial public health problems affecting society today, accounting for roughly 15% of the overall burden of disease from all causes in the United States. Although primary care (PC) has the potential to be the frontline for recognition and management of behavioral health conditions, this has been a challenge historically. In order to more effectively address the broad scope of behavioral health needs, the Air Force Medical Service (AFMS) established a new model of behavioral health care. Through a series of coordinated steps, the AFMS ultimately placed trained behavioral health providers into PC clinics to serve as consultants to PC providers (PCPs). Behavioral Health Consultants (BHCs) provide focused assessments, present healthcare options to patients, and deliver brief collaborative interventions in the PC setting. BHCs see patients at the request of the PCP, in 15-30-min appointments. In the pilot study, patients averaged 1.6 visits to the BHC. Over 70% of patients fell into six categories of presenting problems: situational reactions, depressive disorders, adjustment disorders, anxiety disorders, health promotion, and obesity. Patient data (n = 76) suggest 97% of patients seen were either "satisfied" or "very satisfied" with BHC services, and 100% of the PCPs (n = 23, 68% response rate) were highly satisfied and indicated they would "definitely recommend" others use BHC services for their patients. Both the implications and the limitations of this pilot study are discussed.
Li, Jia; Wu, Pinghui; Chang, Liping
2015-08-24
Within the accuracy of the first-order Born approximation, sufficient conditions are derived for the invariance of spectrum of an electromagnetic wave, which is generated by the scattering of an electromagnetic plane wave from an anisotropic random media. We show that the following restrictions on properties of incident fields and the anisotropic media must be simultaneously satisfied: 1) the elements of the dielectric susceptibility matrix of the media must obey the scaling law; 2) the spectral components of the incident field are proportional to each other; 3) the second moments of the elements of the dielectric susceptibility matrix of the media are inversely proportional to the frequency.
Rondags, S M P A; de Wit, M; Snoek, F J
2016-02-01
Our aim was to study the feasibility and acceptability of our partly online psychoeducational group intervention HypoAware targeted at adults with insulin-treated diabetes and hypoglycaemia problems in an uncontrolled multi-centre pilot study. We developed a 4-week, party online, group intervention, based on key elements of the evidence-based Blood Glucose Awareness Training (BGAT) and with input from diabetes healthcare professionals and people with diabetes. We recruited adults with Type 1 and insulin-treated Type 2 diabetes with impaired hypoglycaemia awareness, frequent hypoglycaemic episodes and/or fear of hypoglycaemia. Feasibility was assessed by means of self-report questionnaires. Pre-post outcomes included self-reported frequency of mild hypoglycaemia, fear of hypoglycaemia, confidence in diabetes self-care, subjective health status, diabetes-specific and general psychological distress and emotional well-being. Organization, recruitment, delivery of HypoAware, retention and compliance yielded no major problems, and both trainers and participants were very satisfied with the programme. The intervention materials required only minor changes. We obtained pre-post intervention measurements in 37 participants from eight hospitals with three drop-outs. Worries about hypoglycaemia, diabetes distress and confidence in self-care improved significantly (P < 0.05), although frequency of hypoglycaemia and hypoglycaemia awareness did not. HypoAware is a new, feasible and acceptable intervention including online modules aimed to help adults with Type 1 and insulin-treated Type 2 diabetes reduce hypoglycaemia and related problems. A cluster-randomized controlled trial is planned to test effectiveness, combined with an economic evaluation. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.
Molas, Marek; Lesaffre, Emmanuel
2008-12-30
Discrete bounded outcome scores (BOS), i.e. discrete measurements that are restricted on a finite interval, often occur in practice. Examples are compliance measures, quality of life measures, etc. In this paper we examine three related random effects approaches to analyze longitudinal studies with a BOS as response: (1) a linear mixed effects (LM) model applied to a logistic transformed modified BOS; (2) a model assuming that the discrete BOS is a coarsened version of a latent random variable, which after a logistic-normal transformation, satisfies an LM model; and (3) a random effects probit model. We consider also the extension whereby the variability of the BOS is allowed to depend on covariates. The methods are contrasted using a simulation study and on a longitudinal project, which documents stroke rehabilitation in four European countries using measures of motor and functional recovery. Copyright 2008 John Wiley & Sons, Ltd.
Portfolio optimization and the random magnet problem
NASA Astrophysics Data System (ADS)
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.
Brock, Rebecca L.; Kochanska, Grazyna; O'Hara, Michael W.; Grekin, Rebecca S.
2015-01-01
This multi-method multi-trait study examined moderators and mediators of change in the context of a parenting intervention. Low-income, diverse mothers of toddlers (average age 30 months; N=186, 90 girls) participated in a play-based intervention (Child-Oriented Play versus Play-as-Usual) aimed at increasing children's committed compliance and reducing opposition toward their mothers, observed in prohibition contexts, and at reducing mother-rated children's behavior problems 6 months after the intervention. Mothers’ subjective sense of life satisfaction and fulfillment during the intervention and objective ratings of psychosocial functioning by clinicians, obtained in a clinical interview were posed as moderators, and mothers’ observed power-assertive discipline immediately following the intervention was modeled as a mediator of its impact. We tested moderated mediation using structural equation modeling, with all baseline scores (prior to randomization) controlled. Mothers’ subjective sense of life satisfaction moderated the impact of the intervention, but clinicians’ ratings did not. For mothers highly satisfied with their lives, participating in Child-Oriented Play group, compared to Play-as-Usual group, led to a reduction in power-assertive discipline which, in turn, led to children's increased compliance and decreased opposition and externalizing problems. There were no effects for mothers who reported low life satisfaction. The study elucidates the causal sequence set in motion by the intervention, demonstrates the moderating role of mothers’ subjective life satisfaction, highlights limitations of clinicians’ ratings, and informs future prevention and intervention efforts to promote adaptive parenting. PMID:25860810
Brock, Rebecca L; Kochanska, Grazyna; O'Hara, Michael W; Grekin, Rebecca S
2015-10-01
This multi-method multi-trait study examined moderators and mediators of change in the context of a parenting intervention. Low-income, diverse mothers of toddlers (average age 30 months; N = 186, 90 girls) participated in a play-based intervention (Child-Oriented Play versus Play-as-Usual) aimed at increasing children's committed compliance and reducing opposition toward their mothers, observed in prohibition contexts, and at reducing mother-rated children's behavior problems 6 months after the intervention. Mothers' subjective sense of life satisfaction and fulfillment during the intervention and objective ratings of psychosocial functioning by clinicians, obtained in a clinical interview were posed as moderators, and mothers' observed power-assertive discipline immediately following the intervention was modeled as a mediator of its impact. We tested moderated mediation using structural equation modeling, with all baseline scores (prior to randomization) controlled. Mothers' subjective sense of life satisfaction moderated the impact of the intervention, but clinicians' ratings did not. For mothers highly satisfied with their lives, participating in Child-Oriented Play group, compared to Play-as-Usual group, led to a reduction in power-assertive discipline which, in turn, led to children's increased compliance and decreased opposition and externalizing problems. There were no effects for mothers who reported low life satisfaction. The study elucidates the causal sequence set in motion by the intervention, demonstrates the moderating role of mothers' subjective life satisfaction, highlights limitations of clinicians' ratings, and informs future prevention and intervention efforts to promote adaptive parenting.
Existence of frozen-in coordinate systems
NASA Technical Reports Server (NTRS)
Chertkov, A. D.
1995-01-01
The 'frozen-in' coordinate systems were first introduced in the works on 'reconnection' and 'magnetic barrier' theories (see review by M.l.Pudovkin and V.S.Semenov, Space Sci. Rev. 41,1 1985). The idea was to utilize the mathematical apparatus developed for 'general relativity' theory to simplify obtaining solutions to the ideal MHD equations set. Magnetic field (B), plasma velocity (v), and their vector product were used as coordinate vectors. But there exist no stationary solutions of ideal MHD set that satisfies the required boundary conditions at infinity (A.D.Chertkov, Solar Wind Seven Conf.,Pergamon Press,1992,165) having non-zero vector product of v and B where v and B originate from the same sphere. The existence of a solution is the hidden mine of the mentioned theories. The solution is constructed in the coordinate system, which is unknown and indeterminate before obtaining this solution. A substitution of the final solution must be done directly into the initial MHD set in order to check the method. One can demonstrate that 'solutions' of Petschek's problem, obtained by 'frozen-in' coordinate systems, does not satisfy just the 'frozen-in' equation, i.e. induction equation. It stems from the fact that Petschek's 're-connection' model, treated as a boundary problem, is over determined. This problem was incorrectly formulated.
Deterministic methods for multi-control fuel loading optimization
NASA Astrophysics Data System (ADS)
Rahman, Fariz B. Abdul
We have developed a multi-control fuel loading optimization code for pressurized water reactors based on deterministic methods. The objective is to flatten the fuel burnup profile, which maximizes overall energy production. The optimal control problem is formulated using the method of Lagrange multipliers and the direct adjoining approach for treatment of the inequality power peaking constraint. The optimality conditions are derived for a multi-dimensional multi-group optimal control problem via calculus of variations. Due to the Hamiltonian having a linear control, our optimal control problem is solved using the gradient method to minimize the Hamiltonian and a Newton step formulation to obtain the optimal control. We are able to satisfy the power peaking constraint during depletion with the control at beginning of cycle (BOC) by building the proper burnup path forward in time and utilizing the adjoint burnup to propagate the information back to the BOC. Our test results show that we are able to achieve our objective and satisfy the power peaking constraint during depletion using either the fissile enrichment or burnable poison as the control. Our fuel loading designs show an increase of 7.8 equivalent full power days (EFPDs) in cycle length compared with 517.4 EFPDs for the AP600 first cycle.
Job satisfaction and patient care practices of hemodialysis nurses and technicians.
Perumal, Seena; Sehgal, Ashwini R
2003-10-01
The quality of hemodialysis care has been the focus of intense scrutiny, yet little is known about the job satisfaction of the nurses and technicians providing this care. We identified 240 nurses and technicians from 307 randomly selected American facilities and asked them about (a) specific domains of job satisfaction, (b) overall job satisfaction, and (c) self-reported patient care practices. Fewer than half of nurses and technicians were satisfied with their pay or their opportunities for advancement. Almost all subjects were satisfied with their personal delivery of patient care, their chance to do things for others, and their job security. About three-fourths of nurses and technicians expressed overall satisfaction with their jobs. Higher job satisfaction was associated with increased attention to patient psychosocial and educational needs. We urge local and national associations of nurses and technicians to collaborate with dialysis facilities, chains, and regulatory agencies to address specific aspects of job satisfaction.
An efficient group multicast routing for multimedia communication
NASA Astrophysics Data System (ADS)
Wang, Yanlin; Sun, Yugen; Yan, Xinfang
2004-04-01
Group multicasting is a kind of communication mechanism whereby each member of a group sends messages to all the other members of the same group. Group multicast routing algorithms capable of satisfying quality of service (QoS) requirements of multimedia applications are essential for high-speed networks. We present a heuristic algorithm for group multicast routing with end to end delay constraint. Source-specific routing trees for each member are generated in our algorithm, which satisfy member"s bandwidth and end to end delay requirements. Simulations over random network were carried out to compare proposed algorithm performance with Low and Song"s. The experimental results show that our proposed algorithm performs better in terms of network cost and ability in constructing feasible multicast trees for group members. Moreover, our algorithm achieves good performance in balancing traffic, which can avoid link blocking and enhance the network behavior efficiently.
Engagement and Retention in Outpatient Alcoholism Treatment for Women
Graff, Fiona S.; Morgan, Thomas J.; Epstein, Elizabeth E.; McCrady, Barbara S.; Cook, Sharon M.; Jensen, Noelle K.; Kelly, Shalonda
2011-01-01
Reviews of the dropout literature note significant attrition from addiction treatment. However, consistent predictors have not been identified and few studies have examined factors related to retention and engagement for women in gender-specific treatment. The current study consisted of 102 women and their partners randomized to individual or couples outpatient alcoholism treatment. Women attended more treatment sessions if they were assigned to individual treatment, older, had fewer symptoms of alcohol dependence, had more satisfying marital relationships, had spouses who drank, and had matched preference for treatment condition. Women were more engaged in treatment (i.e., completed more assigned homework) if they had fewer children at home, fewer alcohol dependence symptoms, later age of onset of alcohol diagnosis, more satisfying marital relationships, and spouses who accepted or encouraged their drinking. Results highlight important associations of treatment and relationship variables with treatment retention and engagement. PMID:19444731
Semiclassical matrix model for quantum chaotic transport with time-reversal symmetry
DOE Office of Scientific and Technical Information (OSTI.GOV)
Novaes, Marcel, E-mail: marcel.novaes@gmail.com
2015-10-15
We show that the semiclassical approach to chaotic quantum transport in the presence of time-reversal symmetry can be described by a matrix model. In other words, we construct a matrix integral whose perturbative expansion satisfies the semiclassical diagrammatic rules for the calculation of transport statistics. One of the virtues of this approach is that it leads very naturally to the semiclassical derivation of universal predictions from random matrix theory.
Multi Objective Controller Design for Linear System via Optimal Interpolation
NASA Technical Reports Server (NTRS)
Ozbay, Hitay
1996-01-01
We propose a methodology for the design of a controller which satisfies a set of closed-loop objectives simultaneously. The set of objectives consists of: (1) pole placement, (2) decoupled command tracking of step inputs at steady-state, and (3) minimization of step response transients with respect to envelope specifications. We first obtain a characterization of all controllers placing the closed-loop poles in a prescribed region of the complex plane. In this characterization, the free parameter matrix Q(s) is to be determined to attain objectives (2) and (3). Objective (2) is expressed as determining a Pareto optimal solution to a vector valued optimization problem. The solution of this problem is obtained by transforming it to a scalar convex optimization problem. This solution determines Q(O) and the remaining freedom in choosing Q(s) is used to satisfy objective (3). We write Q(s) = (l/v(s))bar-Q(s) for a prescribed polynomial v(s). Bar-Q(s) is a polynomial matrix which is arbitrary except that Q(O) and the order of bar-Q(s) are fixed. Obeying these constraints bar-Q(s) is now to be 'shaped' to minimize the step response characteristics of specific input/output pairs according to the maximum envelope violations. This problem is expressed as a vector valued optimization problem using the concept of Pareto optimality. We then investigate a scalar optimization problem associated with this vector valued problem and show that it is convex. The organization of the report is as follows. The next section includes some definitions and preliminary lemmas. We then give the problem statement which is followed by a section including a detailed development of the design procedure. We then consider an aircraft control example. The last section gives some concluding remarks. The Appendix includes the proofs of technical lemmas, printouts of computer programs, and figures.
Preserving correlations between trajectories for efficient path sampling
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gingrich, Todd R.; Geissler, Phillip L.; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
2015-06-21
Importance sampling of trajectories has proved a uniquely successful strategy for exploring rare dynamical behaviors of complex systems in an unbiased way. Carrying out this sampling, however, requires an ability to propose changes to dynamical pathways that are substantial, yet sufficiently modest to obtain reasonable acceptance rates. Satisfying this requirement becomes very challenging in the case of long trajectories, due to the characteristic divergences of chaotic dynamics. Here, we examine schemes for addressing this problem, which engineer correlation between a trial trajectory and its reference path, for instance using artificial forces. Our analysis is facilitated by a modern perspective onmore » Markov chain Monte Carlo sampling, inspired by non-equilibrium statistical mechanics, which clarifies the types of sampling strategies that can scale to long trajectories. Viewed in this light, the most promising such strategy guides a trial trajectory by manipulating the sequence of random numbers that advance its stochastic time evolution, as done in a handful of existing methods. In cases where this “noise guidance” synchronizes trajectories effectively, as the Glauber dynamics of a two-dimensional Ising model, we show that efficient path sampling can be achieved for even very long trajectories.« less
Protective factors against suicide among young-old Chinese outpatients
2014-01-01
Background Suicide is common among the elderly worldwide. However, no literature could be found on the beliefs/expectations that protect young-old people from attempting suicide. The purpose of this study was to explore young-old outpatients’ reasons for not killing themselves in Taiwan. Method Data for this qualitative descriptive study were extracted from a large research series. From the 83 elderly outpatients in the original sample, 31 were chosen for this study because they were young-old (65–74 years old) and from two randomly selected medical centers in northern Taiwan. Data on participants’ reasons for not killing themselves in unhappy situations were collected in individual interviews using a semi-structured guide and analyzed by content analysis. Results Analysis of interview data identified six major themes: satisfied with one’s life, suicide cannot resolve problems, fear of humiliating one’s children, religious beliefs, never thought about suicide, and living in harmony with nature. Conclusion These identified protective factors (reasons for living) could be added to suicide-prevention programs for the elderly. Our findings may also serve as a reference for geriatric researchers in western countries with increasing numbers of elderly ethnic minority immigrants. PMID:24739419
[Molecular techniques applied in species identification of Toxocara].
Fogt, Renata
2006-01-01
Toxocarosis is still an important and actual problem in human medicine. It can manifest as visceral (VLM), ocular (OLM) or covert (CT) larva migrans syndroms. Complicated life cycle of Toxocara, lack of easy and practical methods of species differentiation of the adult nematode and embarrassing in recognition of the infection in definitive hosts create difficulties in fighting with the infection. Although studies on human toxocarosis have been continued for over 50 years there is no conclusive answer, which of species--T. canis or T. cati constitutes a greater risk of transmission of the nematode to man. Neither blood serological examinations nor microscopic observations of the morphological features of the nematode give the satisfied answer on the question. Since the 90-ths molecular methods were developed for species identification and became useful tools being widely applied in parasitological diagnosis. This paper cover the survey of methods of DNA analyses used for identification of Toxocara species. The review may be helpful for researchers focused on Toxocara and toxocarosis as well as on detection of new species. The following techniques are described: PCR (Polymerase Chain Reaction), RFLP (Restriction Fragment Length Polymorphism), RAPD (Random Amplified Polymorphic DNA) and SSCP (Single Strand Conformation Polymorphism).
Optimization of cascade blade mistuning under flutter and forced response constraints
NASA Technical Reports Server (NTRS)
Murthy, D. V.; Haftka, R. T.
1984-01-01
In the development of modern turbomachinery, problems of flutter instabilities and excessive forced response of a cascade of blades that were encountered have often turned out to be extremely difficult to eliminate. The study of these instabilities and the forced response is complicated by the presence of mistuning; that is, small differences among the individual blades. The theory of mistuned cascade behavior shows that mistuning can have a beneficial effect on the stability of the rotor. This beneficial effect is produced by the coupling between the more stable and less stable flutter modes introduced by mistuning. The effect of mistuning on the forced response can be either beneficial or adverse. Kaza and Kielb have studied the effects of two types of mistuning on the flutter and forced response: alternate mistuning where alternte blades are identical and random mistuning. The objective is to investigate other patterns of mistuning which maximize the beneficial effects on the flutter and forced response of the cascade. Numerical optimization techniques are employed to obtain optimal mistuning patterns. The optimization program seeks to minimize the amount of mistuning required to satisfy constraints on flutter speed and forced response.
Robust Dehaze Algorithm for Degraded Image of CMOS Image Sensors.
Qu, Chen; Bi, Du-Yan; Sui, Ping; Chao, Ai-Nong; Wang, Yun-Fei
2017-09-22
The CMOS (Complementary Metal-Oxide-Semiconductor) is a new type of solid image sensor device widely used in object tracking, object recognition, intelligent navigation fields, and so on. However, images captured by outdoor CMOS sensor devices are usually affected by suspended atmospheric particles (such as haze), causing a reduction in image contrast, color distortion problems, and so on. In view of this, we propose a novel dehazing approach based on a local consistent Markov random field (MRF) framework. The neighboring clique in traditional MRF is extended to the non-neighboring clique, which is defined on local consistent blocks based on two clues, where both the atmospheric light and transmission map satisfy the character of local consistency. In this framework, our model can strengthen the restriction of the whole image while incorporating more sophisticated statistical priors, resulting in more expressive power of modeling, thus, solving inadequate detail recovery effectively and alleviating color distortion. Moreover, the local consistent MRF framework can obtain details while maintaining better results for dehazing, which effectively improves the image quality captured by the CMOS image sensor. Experimental results verified that the method proposed has the combined advantages of detail recovery and color preservation.
Utilizing Maximal Independent Sets as Dominating Sets in Scale-Free Networks
NASA Astrophysics Data System (ADS)
Derzsy, N.; Molnar, F., Jr.; Szymanski, B. K.; Korniss, G.
Dominating sets provide key solution to various critical problems in networked systems, such as detecting, monitoring, or controlling the behavior of nodes. Motivated by graph theory literature [Erdos, Israel J. Math. 4, 233 (1966)], we studied maximal independent sets (MIS) as dominating sets in scale-free networks. We investigated the scaling behavior of the size of MIS in artificial scale-free networks with respect to multiple topological properties (size, average degree, power-law exponent, assortativity), evaluated its resilience to network damage resulting from random failure or targeted attack [Molnar et al., Sci. Rep. 5, 8321 (2015)], and compared its efficiency to previously proposed dominating set selection strategies. We showed that, despite its small set size, MIS provides very high resilience against network damage. Using extensive numerical analysis on both synthetic and real-world (social, biological, technological) network samples, we demonstrate that our method effectively satisfies four essential requirements of dominating sets for their practical applicability on large-scale real-world systems: 1.) small set size, 2.) minimal network information required for their construction scheme, 3.) fast and easy computational implementation, and 4.) resiliency to network damage. Supported by DARPA, DTRA, and NSF.
Wilde, Parke E
2007-02-01
The federal government has estimated the prevalence of household "food insecurity" and "food insecurity with hunger" since 1995. Early observers believed that the new measure could be used to assess and improve the Food Stamp Program (FSP). Ten years of research have tempered the initial optimism. The prevalence of food insecurity with hunger (12.3% of all low-income households in 2004) is much higher among food stamp participant households (18.6% in 2004) than among low-income nonparticipant households (10.1% in 2004), due to strong self-selection effects. Households facing greater hardship are more likely to join the program. This article reviews 6 types of nonexperimental research designs that have been used to address the self-selection problem. The results have been inconclusive and the authors have warned against drawing causal inferences from their research. Ethical random-assignment research designs may be required to satisfy the intense policy interest in measuring the antihunger impact of the FSP. The most promising ethical research designs would test the effects of offering eligibility to households that are currently ineligible or offering increased benefits to households that are currently eligible for small benefit amounts.
Choice of optical system is critical for the security of double random phase encryption systems
NASA Astrophysics Data System (ADS)
Muniraj, Inbarasan; Guo, Changliang; Malallah, Ra'ed; Cassidy, Derek; Zhao, Liang; Ryle, James P.; Healy, John J.; Sheridan, John T.
2017-06-01
The linear canonical transform (LCT) is used in modeling a coherent light-field propagation through first-order optical systems. Recently, a generic optical system, known as the quadratic phase encoding system (QPES), for encrypting a two-dimensional image has been reported. In such systems, two random phase keys and the individual LCT parameters (α,β,γ) serve as secret keys of the cryptosystem. It is important that such encryption systems also satisfy some dynamic security properties. We, therefore, examine such systems using two cryptographic evaluation methods, the avalanche effect and bit independence criterion, which indicate the degree of security of the cryptographic algorithms using QPES. We compared our simulation results with the conventional Fourier and the Fresnel transform-based double random phase encryption (DRPE) systems. The results show that the LCT-based DRPE has an excellent avalanche and bit independence characteristics compared to the conventional Fourier and Fresnel-based encryption systems.
Nash, Peter; Mease, Philip J; McInnes, Iain B; Rahman, Proton; Ritchlin, Christopher T; Blanco, Ricardo; Dokoupilova, Eva; Andersson, Mats; Kajekar, Radhika; Mpofu, Shephard; Pricop, Luminita
2018-03-15
The study aimed to assess 52-week efficacy and safety of secukinumab self-administration by autoinjector in patients with active psoriatic arthritis (PsA) in the FUTURE 3 study ( ClinicalTrials.gov NCT01989468). Patients (≥ 18 years of age; N = 414) with active PsA were randomized 1:1:1 to subcutaneous (s.c.) secukinumab 300 mg, 150 mg, or placebo at baseline, weeks 1, 2, 3, and 4, and every 4 weeks thereafter. Per clinical response, placebo-treated patients were re-randomized to s.c. secukinumab 300 or 150 mg at week 16 (nonresponders) or week 24 (responders) and stratified at randomization by prior anti-tumor necrosis factor (TNF) therapy (anti-TNF-naïve, 68.1%; intolerant/inadequate response (anti-TNF-IR), 31.9%). The primary endpoint was the proportion of patients achieving at least 20% improvement in American College of Rheumatology response criteria (ACR20) at week 24. Autoinjector usability was evaluated by Self-Injection Assessment Questionnaire (SIAQ). Overall, 92.1% (300 mg), 91.3% (150 mg), and 93.4% (placebo) of patients completed 24 weeks, and 84.9% (300 mg) and 79.7% (150 mg) completed 52 weeks. In the overall population (combined anti-TNF-naïve and anti-TNF-IR), ACR20 response rate at week 24 was significantly higher in secukinumab groups (300 mg, 48.2% (p < 0.0001); 150 mg, 42% (p < 0.0001); placebo, 16.1%) and was sustained through 52 weeks. SIAQ results showed that more than 93% of patients were satisfied/very satisfied with autoinjector usage. Secukinumab was well tolerated with no new or unexpected safety signals reported. Secukinumab provided sustained improvements in signs and symptoms in active PsA patients through 52 weeks. High acceptability of autoinjector was observed. The safety profile was consistent with that reported previously. ClinicalTrials.gov NCT01989468 . Registered 21 November 2013. EudraCT 2013-004002-25 . Registered 17 December 2013.
Lester, Felicia; Kakaire, Othman; Byamugisha, Josaphat; Averbach, Sarah; Fortin, Jennifer; Maurer, Rie; Goldberg, Alisa
2015-03-01
To compare rates of Copper T380A intrauterine device (IUD) utilization and satisfaction with immediate versus delayed IUD insertion after cesarean delivery in Kampala, Uganda. This study was a randomized clinical trial of women undergoing cesarean section who desired an IUD in Kampala, Uganda. Participants were randomly assigned to IUD insertion at the time of cesarean delivery or 6weeks afterward. The primary outcome was IUD utilization at 6months after delivery. Among 68 women who underwent randomization, an IUD was inserted in 100% (34/34) of the women in the immediate insertion group and in 53% (18/34) in the delayed group. IUD use at 6 months was higher in the immediate insertion group (93% vs. 50% after delayed insertion; p<.0001). Infection and expulsion were rare and did not differ between groups. When we pooled both groups and looked at IUD users compared to nonusers, 91% (39/43) of IUD users were satisfied or very satisfied with their contraceptive method compared to 44% (11/25) of nonusers (p<.0001). Women who chose not to be in the study or had the IUD removed often did so because of perceived husband or community disapproval. The 6-month utilization of an IUD after immediate insertion was significantly higher than after delayed insertion without increased complications. Contraceptive satisfaction was significantly higher among IUD users than nonusers. Community and husband attitudes influence IUD utilization and continuation in Kampala, Uganda. This work is important because it shows the safety and efficacy of providing IUDs during cesarean section in a setting where access to any healthcare, including contraception, can be extremely limited outside of childbearing and the consequences of an unintended, closely spaced pregnancy after a cesarean section can be life threatening. Copyright © 2015 Elsevier Inc. All rights reserved.
Optimal aeroassisted orbital transfer with plane change using collocation and nonlinear programming
NASA Technical Reports Server (NTRS)
Shi, Yun. Y.; Nelson, R. L.; Young, D. H.
1990-01-01
The fuel optimal control problem arising in the non-planar orbital transfer employing aeroassisted technology is addressed. The mission involves the transfer from high energy orbit (HEO) to low energy orbit (LEO) with orbital plane change. The basic strategy here is to employ a combination of propulsive maneuvers in space and aerodynamic maneuvers in the atmosphere. The basic sequence of events for the aeroassisted HEO to LEO transfer consists of three phases. In the first phase, the orbital transfer begins with a deorbit impulse at HEO which injects the vehicle into an elliptic transfer orbit with perigee inside the atmosphere. In the second phase, the vehicle is optimally controlled by lift and bank angle modulations to perform the desired orbital plane change and to satisfy heating constraints. Because of the energy loss during the turn, an impulse is required to initiate the third phase to boost the vehicle back to the desired LEO orbital altitude. The third impulse is then used to circularize the orbit at LEO. The problem is solved by a direct optimization technique which uses piecewise polynomial representation for the state and control variables and collocation to satisfy the differential equations. This technique converts the optimal control problem into a nonlinear programming problem which is solved numerically. Solutions were obtained for cases with and without heat constraints and for cases of different orbital inclination changes. The method appears to be more powerful and robust than other optimization methods. In addition, the method can handle complex dynamical constraints.
Gender Problems in Western Theatrical Dance: Little Girls, Big Sissies & the "Baryshnikov Complex"
ERIC Educational Resources Information Center
Risner, Doug
2014-01-01
General education programs, in postsecondary institutions, provide a broad base of learning in the liberal arts and sciences with common goals that prepare undergraduate students for living informed and satisfying lives. In the United States, dance units in public institutions, offering general education coursework for non-majors (dance…
Analytical Methods in Search Theory
1979-11-01
X, t ) ,I pick g(x,t;E), *(x,tjc) and find the b necessary to satisfy the search equation. SOLUTION: This is an audience participation problem. It...Cnstotiaticon G11trant,’ ’I pp 2110 Path lestegsls,’ to pp., Jun IBM Iltetteol Pepsi pp., Ott 1313 (Tt o besubmitoet lot pubtinatteon l t Messino, Daidit
Educational and Psychological Aspects of Environmental Awareness and a Sense of Belonging
ERIC Educational Resources Information Center
Rode, Ojars
2015-01-01
The research problem concerns the sphere of relationships with the environment and an individual's awareness in the aspect of satisfying the need for belonging. This research aims to determine the conditions of relationships with the environment and an individual's awareness in the process of personality formation. The research is constituted by…
Considerations for lunar colony communications systems
NASA Technical Reports Server (NTRS)
Dowling, Richard P.
1992-01-01
This paper addresses system aspects of communications for a lunar colony. Human factors are particularly noted. The practical aspects of communications infrastructure are emphasized rather than specific technologies. Communications needs for mission support and morale are discussed along with potential means of satisfying them. Problem areas are identified and some possible solutions are considered.
Problems of the design of low-noise input devices. [parametric amplifiers
NASA Technical Reports Server (NTRS)
Manokhin, V. M.; Nemlikher, Y. A.; Strukov, I. A.; Sharfov, Y. A.
1974-01-01
An analysis is given of the requirements placed on the elements of parametric centimeter waveband amplifiers for achievement of minimal noise temperatures. A low-noise semiconductor parametric amplifier using germanium parametric diodes for a receiver operating in the 4 GHz band was developed and tested confirming the possibility of satisfying all requirements.
Soil water sensors:Problems, advances and potential for irrigation scheduling
USDA-ARS?s Scientific Manuscript database
Irrigation water management has to do with the appropriate application of water to soils, in terms of amounts, rates, and timing to satisfy crop water demands, while protecting the soil and water resources from degradation. In this regard, sensors can be used to monitor the soil water status; and so...
The Black Man's Burden: The White Clinician
ERIC Educational Resources Information Center
Wesson, K. Alan
1975-01-01
The stated purpose of this article is to advocate that those dealing with black people and black problems have some appreciable degree of knowledge concerning black culture, black jargon, black behavior, and the black or Afro-American psyche: only then can therapy be seen as satisfying the purposes for which it was initially intended. (Author/JM)
JPRS Report, Soviet Union, Foreign Military Review, No. 4, April 1988
1988-12-22
CPSU feels that unwea- kening concern for solving the social problems of labor, life and culture and for satisfying the interests and needs of the...were 60 tankers with a total cargo capacity of 4.8 million tons in the merchant fleet); in recent years, however, the quantity of ships in operation
USDA-ARS?s Scientific Manuscript database
Chemical fertilizers are being extensively used to satisfy the increasing demand for food. However, utilization of chemical fertilizers can be costly and over application for ensuring crop productivity may lead to environmental problems. As a result, interest in using bio-fertilizers to improve soil...
ERIC Educational Resources Information Center
Frederick, Patricia A.
2010-01-01
The number of underprepared students entering post-secondary education continues to be a national problem community colleges struggle with by providing remedial instruction while having to satisfy the demands for effective teaching accountability. Reading is one identified area needing remediation; and, a goal for programs to address this…
Single Sex Classes for Gifted Students: A Case Report.
ERIC Educational Resources Information Center
Kravetz, Nathan
A summer math class for gifted girls (grades 5-9) was established and conducted by a female instructor for 3 weeks. The class involved take-home work, puzzles, problem solving, and computer work. Parents and students were satisfied with the enrichment class, but questions remained concerning such an approach's legality, the advisability of…
Empathy and Child Neglect: A Theoretical Model
ERIC Educational Resources Information Center
De Paul, Joaquin; Guibert, Maria
2008-01-01
Objective: To present an explanatory theory-based model of child neglect. This model does not address neglectful behaviors of parents with mental retardation, alcohol or drug abuse, or severe mental health problems. In this model parental behavior aimed to satisfy a child's need is considered a helping behavior and, as a consequence, child neglect…
Optimization of a bundle divertor for FED
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hively, L.M.; Rothe, K.E.; Minkoff, M.
1982-01-01
Optimal double-T bundle divertor configurations have been obtained for the Fusion Engineering Device (FED). On-axis ripple is minimized, while satisfying a series of engineering constraints. The ensuing non-linear optimization problem is solved via a sequence of quadratic programming subproblems, using the VMCON algorithm. The resulting divertor designs are substantially improved over previous configurations.
The Problems of Educational Standards in the United States and Russia.
ERIC Educational Resources Information Center
Bespal'ko, V. P.
1996-01-01
Compares and contrasts the need for educational standards in the United States and Russia. Argues that both systems burden their students with an excess of peripheral and inconsequential material in order to satisfy outdated pedagogical objectives. Praises American efforts at creating national standards but questions their applicability to Russia.…
Marital Satisfaction: Factors for Black Jamaicans and African Americans Living in the United States
ERIC Educational Resources Information Center
Edwards, Nivischi Ngozi
2009-01-01
Marital satisfaction is the strongest predictor for happiness in many areas of life (Russel & Wells, 1994). A satisfying marriage is associated with better general adjustment and fewer health problems (Bray & Jouriles, 1995). Factors that contribute to marital satisfaction reported by researchers include religion and spirituality (Anthony,…
Hard Constraints in Optimization Under Uncertainty
NASA Technical Reports Server (NTRS)
Crespo, Luis G.; Giesy, Daniel P.; Kenny, Sean P.
2008-01-01
This paper proposes a methodology for the analysis and design of systems subject to parametric uncertainty where design requirements are specified via hard inequality constraints. Hard constraints are those that must be satisfied for all parameter realizations within a given uncertainty model. Uncertainty models given by norm-bounded perturbations from a nominal parameter value, i.e., hyper-spheres, and by sets of independently bounded uncertain variables, i.e., hyper-rectangles, are the focus of this paper. These models, which are also quite practical, allow for a rigorous mathematical treatment within the proposed framework. Hard constraint feasibility is determined by sizing the largest uncertainty set for which the design requirements are satisfied. Analytically verifiable assessments of robustness are attained by comparing this set with the actual uncertainty model. Strategies that enable the comparison of the robustness characteristics of competing design alternatives, the description and approximation of the robust design space, and the systematic search for designs with improved robustness are also proposed. Since the problem formulation is generic and the tools derived only require standard optimization algorithms for their implementation, this methodology is applicable to a broad range of engineering problems.
Application of Harmony Search algorithm to the solution of groundwater management models
NASA Astrophysics Data System (ADS)
Tamer Ayvaz, M.
2009-06-01
This study proposes a groundwater resources management model in which the solution is performed through a combined simulation-optimization model. A modular three-dimensional finite difference groundwater flow model, MODFLOW is used as the simulation model. This model is then combined with a Harmony Search (HS) optimization algorithm which is based on the musical process of searching for a perfect state of harmony. The performance of the proposed HS based management model is tested on three separate groundwater management problems: (i) maximization of total pumping from an aquifer (steady-state); (ii) minimization of the total pumping cost to satisfy the given demand (steady-state); and (iii) minimization of the pumping cost to satisfy the given demand for multiple management periods (transient). The sensitivity of HS algorithm is evaluated by performing a sensitivity analysis which aims to determine the impact of related solution parameters on convergence behavior. The results show that HS yields nearly same or better solutions than the previous solution methods and may be used to solve management problems in groundwater modeling.
Bor, William; Heath, Fiona; Heussler, Honey; Reuter, Rebecca; Perrett, Carmel; Lee, Erica
2013-10-01
Public, consumer and professional views about attention deficit hyperactivity disorder, its assessment and treatment - especially with medication - remain a highly contested domain. Parents in particular express disquiet with services. One response to this tension is a multidisciplinary evaluation. Parental and education perceptions of this process have not been evaluated previously. A community multidisciplinary approach was assessed in terms of diagnostic outcomes and client satisfaction. A comprehensive multidisciplinary structured assessment of the first 50 referred children with severe attentional problems was documented. Demographic and symptom/behavioural profiles, developmental history and indicated multi-disciplinary evaluation were recorded. A team consensus process arrived at diagnostic classification. Post-assessment satisfaction of parents and school staff was surveyed. Thirteen children (26%) were diagnosed with attention deficit hyperactivity disorder and three commenced stimulants. The majority of parents and educators were satisfied with the service. A multidisciplinary assessment clinic for children presenting with attention problems resulted in minimal prescribing. Overall, education staff and parents were satisfied with the service. The model may be a suitable response to the multiple concerns in the community.
Distance estimation and collision prediction for on-line robotic motion planning
NASA Technical Reports Server (NTRS)
Kyriakopoulos, K. J.; Saridis, G. N.
1992-01-01
An efficient method for computing the minimum distance and predicting collisions between moving objects is presented. This problem is incorporated into the framework of an in-line motion-planning algorithm to satisfy collision avoidance between a robot and moving objects modeled as convex polyhedra. In the beginning, the deterministic problem where the information about the objects is assumed to be certain is examined. L(1) or L(infinity) norms are used to represent distance and the problem becomes a linear programming problem. The stochastic problem is formulated where the uncertainty is induced by sensing and the unknown dynamics of the moving obstacles. Two problems are considered: First, filtering of the distance between the robot and the moving object at the present time. Second, prediction of the minimum distance in the future in order to predict the collision time.
Molecular computation: RNA solutions to chess problems
Faulhammer, Dirk; Cukras, Anthony R.; Lipton, Richard J.; Landweber, Laura F.
2000-01-01
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 × 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 × 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. PMID:10677471
Hilbert's sixth problem and the failure of the Boltzmann to Euler limit
NASA Astrophysics Data System (ADS)
Slemrod, Marshall
2018-04-01
This paper addresses the main issue of Hilbert's sixth problem, namely the rigorous passage of solutions to the mesoscopic Boltzmann equation to macroscopic solutions of the Euler equations of compressible gas dynamics. The results of the paper are that (i) in general Hilbert's program will fail because of the appearance of van der Waals-Korteweg capillarity terms in a macroscopic description of motion of a gas, and (ii) the van der Waals-Korteweg theory itself might satisfy Hilbert's quest for a map from the `atomistic view' to the laws of motion of continua. This article is part of the theme issue `Hilbert's sixth problem'.
Optimal Decision Making in a Class of Uncertain Systems Based on Uncertain Variables
NASA Astrophysics Data System (ADS)
Bubnicki, Z.
2006-06-01
The paper is concerned with a class of uncertain systems described by relational knowledge representations with unknown parameters which are assumed to be values of uncertain variables characterized by a user in the form of certainty distributions. The first part presents the basic optimization problem consisting in finding the decision maximizing the certainty index that the requirement given by a user is satisfied. The main part is devoted to the description of the optimization problem with the given certainty threshold. It is shown how the approach presented in the paper may be applied to some problems for anticipatory systems.
Random Matrix Approach for Primal-Dual Portfolio Optimization Problems
NASA Astrophysics Data System (ADS)
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.
Field equations from Killing spinors
NASA Astrophysics Data System (ADS)
Açık, Özgür
2018-02-01
From the Killing spinor equation and the equations satisfied by their bilinears, we deduce some well-known bosonic and fermionic field equations of mathematical physics. Aside from the trivially satisfied Dirac equation, these relativistic wave equations in curved spacetimes, respectively, are Klein-Gordon, Maxwell, Proca, Duffin-Kemmer-Petiau, Kähler, twistor, and Rarita-Schwinger equations. This result shows that, besides being special kinds of Dirac fermions, Killing fermions can be regarded as physically fundamental. For the Maxwell case, the problem of motion is analysed in a reverse manner with respect to the studies of Einstein-Groemer-Infeld-Hoffmann and Jean Marie Souriau. In the analysis of the gravitino field, a generalised 3-ψ rule is found which is termed the vanishing trace constraint.
Analysis of entropy extraction efficiencies in random number generation systems
NASA Astrophysics Data System (ADS)
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.
A sequential solution for anisotropic total variation image denoising with interval constraints
NASA Astrophysics Data System (ADS)
Xu, Jingyan; Noo, Frédéric
2017-09-01
We show that two problems involving the anisotropic total variation (TV) and interval constraints on the unknown variables admit, under some conditions, a simple sequential solution. Problem 1 is a constrained TV penalized image denoising problem; problem 2 is a constrained fused lasso signal approximator. The sequential solution entails finding first the solution to the unconstrained problem, and then applying a thresholding to satisfy the constraints. If the interval constraints are uniform, this sequential solution solves problem 1. If the interval constraints furthermore contain zero, the sequential solution solves problem 2. Here uniform interval constraints refer to all unknowns being constrained to the same interval. A typical example of application is image denoising in x-ray CT, where the image intensities are non-negative as they physically represent linear attenuation coefficient in the patient body. Our results are simple yet seem unknown; we establish them using the Karush-Kuhn-Tucker conditions for constrained convex optimization.
Blonstein, Andrea C; Lv, Nan; Camargo, Carlos A; Wilson, Sandra R; Buist, A Sonia; Rosas, Lisa G; Strub, Peg; Ma, Jun
2016-08-01
'DASH for Asthma' (n 90) was a 6-month randomized controlled trial that demonstrated potential benefits of a DASH (Dietary Approaches to Stop Hypertension) behavioural intervention for improving diet quality and asthma control by comparing intervention to usual care in adults with uncontrolled asthma. The present study examined acceptability and feasibility of the intervention from the perspective of intervention participants and lifestyle coaches. Grounded in Social Cognitive Theory, the 3-month intensive stage, including three individual and eight group sessions, focused on diet modifications and behavioural self-regulation. The 3-month maintenance stage contained telephone consultations. Participants and lifestyle coaches completed surveys including 5-point Likert scales and open-ended questions. We analysed data using descriptive and inductive content analyses. Forty-six intervention participants (survey response rate was 65-72 %) and two lifestyle coaches. Participants and lifestyle coaches were highly satisfied (all mean ratings >4) with individual and group sessions. Participants identified mastery of knowledge and skills (awareness, goal setting, self-monitoring, problem solving), social learning (class members sharing experiences and ideas) and good coaching skills (reflective listening, empathy, motivational counselling) as important contributors to self-efficacy and programme satisfaction. Participants also valued personalized feedback received in individual sessions. Lifestyle coaches viewed participant engagement as a facilitator to effective sessions. Finally, participants and lifestyle coaches identified food tasting as beneficial for observational learning and facilitation of participant engagement. High class attendance and self-monitoring rate also reflected the high engagement among participants. The DASH behavioural intervention was feasible and highly acceptable to participants with uncontrolled asthma and lifestyle coaches.
Carroll, Raymond J; Delaigle, Aurore; Hall, Peter
2011-03-01
In many applications we can expect that, or are interested to know if, a density function or a regression curve satisfies some specific shape constraints. For example, when the explanatory variable, X, represents the value taken by a treatment or dosage, the conditional mean of the response, Y , is often anticipated to be a monotone function of X. Indeed, if this regression mean is not monotone (in the appropriate direction) then the medical or commercial value of the treatment is likely to be significantly curtailed, at least for values of X that lie beyond the point at which monotonicity fails. In the case of a density, common shape constraints include log-concavity and unimodality. If we can correctly guess the shape of a curve, then nonparametric estimators can be improved by taking this information into account. Addressing such problems requires a method for testing the hypothesis that the curve of interest satisfies a shape constraint, and, if the conclusion of the test is positive, a technique for estimating the curve subject to the constraint. Nonparametric methodology for solving these problems already exists, but only in cases where the covariates are observed precisely. However in many problems, data can only be observed with measurement errors, and the methods employed in the error-free case typically do not carry over to this error context. In this paper we develop a novel approach to hypothesis testing and function estimation under shape constraints, which is valid in the context of measurement errors. Our method is based on tilting an estimator of the density or the regression mean until it satisfies the shape constraint, and we take as our test statistic the distance through which it is tilted. Bootstrap methods are used to calibrate the test. The constrained curve estimators that we develop are also based on tilting, and in that context our work has points of contact with methodology in the error-free case.
Meniscus on a shaped fibre: singularities and hodograph formulation.
Alimov, Mars M; Kornev, Konstantin G
2014-08-08
Using the method of matched asymptotic expansions, the problem of the capillary rise of a meniscus on the complex-shaped fibres was reduced to a nonlinear problem of determination of a minimal surface. This surface has to satisfy a special boundary condition at infinity. The proposed formulation allows one to interpret the meniscus problem as a problem of flow of a fictitious non-Newtonian fluid through a porous medium. As an example, the shape of a meniscus on a fibre of an oval cross section was analysed employing Chaplygin's hodograph transformation. It was discovered that the contact line may form singularities even if the fibre has a smooth profile: this statement was illustrated with an oval fibre profile having infinite curvature at two endpoints.
Meniscus on a shaped fibre: singularities and hodograph formulation
Alimov, Mars M.; Kornev, Konstantin G.
2014-01-01
Using the method of matched asymptotic expansions, the problem of the capillary rise of a meniscus on the complex-shaped fibres was reduced to a nonlinear problem of determination of a minimal surface. This surface has to satisfy a special boundary condition at infinity. The proposed formulation allows one to interpret the meniscus problem as a problem of flow of a fictitious non-Newtonian fluid through a porous medium. As an example, the shape of a meniscus on a fibre of an oval cross section was analysed employing Chaplygin's hodograph transformation. It was discovered that the contact line may form singularities even if the fibre has a smooth profile: this statement was illustrated with an oval fibre profile having infinite curvature at two endpoints. PMID:25104910
Equitability, mutual information, and the maximal information coefficient.
Kinney, Justin B; Atwal, Gurinder S
2014-03-04
How should one quantify the strength of association between two random variables without bias for relationships of a specific form? Despite its conceptual simplicity, this notion of statistical "equitability" has yet to receive a definitive mathematical formalization. Here we argue that equitability is properly formalized by a self-consistency condition closely related to Data Processing Inequality. Mutual information, a fundamental quantity in information theory, is shown to satisfy this equitability criterion. These findings are at odds with the recent work of Reshef et al. [Reshef DN, et al. (2011) Science 334(6062):1518-1524], which proposed an alternative definition of equitability and introduced a new statistic, the "maximal information coefficient" (MIC), said to satisfy equitability in contradistinction to mutual information. These conclusions, however, were supported only with limited simulation evidence, not with mathematical arguments. Upon revisiting these claims, we prove that the mathematical definition of equitability proposed by Reshef et al. cannot be satisfied by any (nontrivial) dependence measure. We also identify artifacts in the reported simulation evidence. When these artifacts are removed, estimates of mutual information are found to be more equitable than estimates of MIC. Mutual information is also observed to have consistently higher statistical power than MIC. We conclude that estimating mutual information provides a natural (and often practical) way to equitably quantify statistical associations in large datasets.
Predictors of Job Satisfaction in Dental Professionals of the Bosnia and Herzegovina Federation
Muhic, Edin; Plancak, Darije; Muhic, Asja
2016-01-01
Introduction Working in a healthy work environment is the ultimate goal of every employee. Dentistry is a stressful career, and the reasons for dissatisfaction are numerous. Aim The aim of this study was to determine the factors of work satisfaction in dental professionals of the Bosnia and Herzegovina Federation. Materials and methods A total of 134 dental professionals selected randomly from the Registry of Dental Chamber of Bosnia and Herzegovina Federation were included in the study. All of them filled out the Demographic Questionnaire and Job Satisfaction Scale (JSS). Results An increase in the influence of work on the quality of life as well as an increase in its frequency results in leaving the job and significantly reducing the overall job satisfaction. General dental practitioners are significantly more satisfied as compared with specialists. Significant predictors of the job satisfaction are employment status, type of the practice, and availability of dental assistants. General dental practitioners with a dental assistant employed at a private practice are more likely to be satisfied with their jobs. Conclusions Employment status, practice type and availability of dental assistants are significant predictors of job satisfaction. General dental practitioners working in a private practice with a dental assistant are most likely to be satisfied. PMID:27847395
Kekäle, Meri; Söderlund, Tim; Koskenvesa, Perttu; Talvensaari, Kimmo; Airaksinen, Marja
2016-09-01
The aim of this study was to evaluate the influence of tailored patient education on adherence to tyrosine kinase inhibitor medication among patients with chronic myeloid leukaemia. Management of chronic myeloid leukaemia has changed dramatically during the last decade. While medication adherence is crucial to clinical response, little is known about how to improve patients' adherence. Randomized multicentre intervention study. The study was conducted between June 2012-August 2014. Eighty-six patients with chronic myeloid leukaemia who had been on tyrosine kinase inhibitor medication for at least six months from eight hospitals were randomized into intervention and control groups. Intervention combined nurse-conducted medication counselling, an information booklet, video and website and text message reminders. Patients were interviewed to assess medication adherence using Morisky's 8-Item Medication Adherence Scale at baseline and nine months. Medication adherence improved with the adherence aids used. At nine months, 51% of patients were highly adherent in the intervention group, compared with 21% in the control group. Adherence improved for a higher proportion of patients in the intervention group than the control group (49% vs. 18%). Morisky's score decreased in almost half of control group cases. Patients were most satisfied with face-to-face counselling (86%) and the information booklet (83%) and least satisfied with text messages (9%). Tailored patient education improved the medication adherence of patients with chronic myeloid leukaemia. Without this, adherence behaviour tended to decline. Personal communication with a nurse proved to be an essential part of adherence support and should not be ignored. © 2016 John Wiley & Sons Ltd.
Bebbington, M W; Treissman, M J
1996-10-01
Our purpose was to compare the effectiveness of a surgical assist device, SutureMate, to decrease glove perforations during postdelivery vaginal repair. This was a prospective randomized trial. After delivery surgeons who needed to perform vaginal repair were randomized to use the surgical assist device or to perform the repair in the usual fashion. After the repair, gloves were collected and the operator was asked to complete a standardized data form that was submitted with the gloves. The gloves were tested for perforations within 24 hours by the Food and Drug Administration-approved hydrosufflation technique. Comparisons were made with chi(2) statistics with p < 0.01 taken as being statistically significant with the use of a Bonferoni adjustment for multiple comparisons. A total of 476 glove sets were evaluated. The use of the surgical assist device significantly reduced the overall glove perforation rate from 28.3% in the control arm to 8.4% in the study arm (p = 0.0001). Rates of perforation varied with level of training and expertise but fell in all groups that used the device. Family physicians had the highest perforation rate in the control arm and benefited most from the device. A total of 76% of perforations were located in the thumb, index, and second fingers of the nondominant hand. Perforations were recognized in only 16% of the glove sets. The level of satisfaction with the device was mixed, but overall 50% of operators indicated that they were either satisfied or very satisfied with the device. The rate of glove perforation in postdelivery vaginal repair is high. The surgical assist device significantly reduced the rate of glove perforations.
Plazier, Mark; Ost, Jan; Stassijns, Gaëtane; De Ridder, Dirk; Vanneste, Sven
2015-01-01
Fibromyalgia is a condition characterized by widespread chronic pain. Due to the high prevalence and high costs, it has a substantial burden on society. Treatment results are diverse and only help a small subset of patients. C2 nerve field stimulation, aka occipital nerve stimulation, is helpful and a minimally invasive treatment for primary headache syndromes. Small C2 pilot studies seem to be beneficial in fibromyalgia. Forty patients were implanted with a subcutaneous electrode in the C2 dermatoma as part of a prospective, double-blind, randomized, controlled cross-over study followed by an open label follow up period of 6 months. The patients underwent 2 week periods of different doses of stimulation consisting of minimal (.1 mA), subthreshold, and suprathreshold (for paresthesias) in a randomized order. Twenty seven patients received a permanent implant and 25 completed the 6 month open label follow up period. During the 6 week trial phase of the study, patients had an overall decrease of 36% on the fibromyalgia impact questionnaire (FIQ), a decrease of 33% fibromyalgia pain and improvement of 42% on the impact on daily life activities and quality. These results imply an overall improvement in the disease burden, maintained at 6 months follow up, as well as an improvement in life quality of 50%. Seventy six percent of patients were satisfied or very satisfied with their treatment. There seems to be a dose-response curve, with increasing amplitudes leading to better clinical outcomes. Subcutaneous C2 nerve field stimulation seems to offer a safe and effective treatment option for selected medically intractable patients with fibromyalgia. Copyright © 2015 Elsevier Inc. All rights reserved.
Parabolic Systems with p, q-Growth: A Variational Approach
NASA Astrophysics Data System (ADS)
Bögelein, Verena; Duzaar, Frank; Marcellini, Paolo
2013-10-01
We consider the evolution problem associated with a convex integrand {f : {R}^{Nn}to [0,infty)} satisfying a non-standard p, q-growth assumption. To establish the existence of solutions we introduce the concept of variational solutions. In contrast to weak solutions, that is, mappings {u\\colon Ω_T to {R}^n} which solve partial_tu-div Df(Du)=0 weakly in {Ω_T}, variational solutions exist under a much weaker assumption on the gap q - p. Here, we prove the existence of variational solutions provided the integrand f is strictly convex and 2n/n+2 < p le q < p+1. These variational solutions turn out to be unique under certain mild additional assumptions on the data. Moreover, if the gap satisfies the natural stronger assumption 2le p le q < p+ minbig \\{1,4/n big \\}, we show that variational solutions are actually weak solutions. This means that solutions u admit the necessary higher integrability of the spatial derivative Du to satisfy the parabolic system in the weak sense, that is, we prove that uin L^q_locbig(0,T; W^{1,q}_loc(Ω,{R}^N)big).
ERIC Educational Resources Information Center
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…
Seminar on Understanding Digital Control and Analysis in Vibration Test Systems, part 2
NASA Technical Reports Server (NTRS)
1975-01-01
A number of techniques for dealing with important technical aspects of the random vibration control problem are described. These include the generation of pseudo-random and true random noise, the control spectrum estimation problem, the accuracy/speed tradeoff, and control correction strategies. System hardware, the operator-system interface, safety features, and operational capabilities of sophisticated digital random vibration control systems are also discussed.
NASA Astrophysics Data System (ADS)
Dong, Siqun; Zhao, Dianli
2018-01-01
This paper studies the subcritical, near-critical and supercritical asymptotic behavior of a reversible random coagulation-fragmentation polymerization process as N → ∞, with the number of distinct ways to form a k-clusters from k units satisfying f(k) =(1 + o (1)) cr-ke-kαk-β, where 0 < α < 1 and β > 0. When the cluster size is small, its distribution is proved to converge to the Gaussian distribution. For the medium clusters, its distribution will converge to Poisson distribution in supercritical stage, and no large clusters exist in this stage. Furthermore, the largest length of polymers of size N is of order ln N in the subcritical stage under α ⩽ 1 / 2.
Correlations of RMT characteristic polynomials and integrability: Hermitean matrices
DOE Office of Scientific and Technical Information (OSTI.GOV)
Osipov, Vladimir Al., E-mail: Vladimir.Osipov@uni-due.d; Kanzieper, Eugene, E-mail: Eugene.Kanzieper@hit.ac.i; Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100
Integrable theory is formulated for correlation functions of characteristic polynomials associated with invariant non-Gaussian ensembles of Hermitean random matrices. By embedding the correlation functions of interest into a more general theory of {tau} functions, we (i) identify a zoo of hierarchical relations satisfied by {tau} functions in an abstract infinite-dimensional space and (ii) present a technology to translate these relations into hierarchically structured nonlinear differential equations describing the correlation functions of characteristic polynomials in the physical, spectral space. Implications of this formalism for fermionic, bosonic, and supersymmetric variations of zero-dimensional replica field theories are discussed at length. A particular emphasismore » is placed on the phenomenon of fermionic-bosonic factorisation of random-matrix-theory correlation functions.« less
Reinterpretaion of the friendship paradox
NASA Astrophysics Data System (ADS)
Fu, Jingcheng; Wu, Jianliang
The friendship paradox (FP) is a sociological phenomenon stating that most people have fewer friends than their friends do. It is to say that in a social network, the number of friends that most individuals have is smaller than the average number of friends of friends. This has been verified by Feld. We call this interpreting method mean value version. But is it the best choice to portray the paradox? In this paper, we propose a probability method to reinterpret this paradox, and we illustrate that the explanation using our method is more persuasive. An individual satisfies the FP if his (her) randomly chosen friend has more friends than him (her) with probability not less than 1/2. Comparing the ratios of nodes satisfying the FP in networks, rp, we can see that the probability version is stronger than the mean value version in real networks both online and offline. We also show some results about the effects of several parameters on rp in random network models. Most importantly, rp is a quadratic polynomial of the power law exponent γ in Price model, and rp is higher when the average clustering coefficient is between 0.4 and 0.5 in Petter-Beom (PB) model. The introduction of the probability method to FP can shed light on understanding the network structure in complex networks especially in social networks.
Random Walks and Effective Optical Depth in Relativistic Flow
NASA Astrophysics Data System (ADS)
Shibata, Sanshiro; Tominaga, Nozomu; Tanaka, Masaomi
2014-05-01
We investigate the random walk process in relativistic flow. In the relativistic flow, photon propagation is concentrated in the direction of the flow velocity due to the relativistic beaming effect. We show that in the pure scattering case, the number of scatterings is proportional to the size parameter ξ ≡ L/l 0 if the flow velocity β ≡ v/c satisfies β/Γ Gt ξ-1, while it is proportional to ξ2 if β/Γ Lt ξ-1, where L and l 0 are the size of the system in the observer frame and the mean free path in the comoving frame, respectively. We also examine the photon propagation in the scattering and absorptive medium. We find that if the optical depth for absorption τa is considerably smaller than the optical depth for scattering τs (τa/τs Lt 1) and the flow velocity satisfies \\beta \\gg \\sqrt{2\\tau _a/\\tau _s}, then the effective optical depth is approximated by τ* ~= τa(1 + β)/β. Furthermore, we perform Monte Carlo simulations of radiative transfer and compare the results with the analytic expression for the number of scatterings. The analytic expression is consistent with the results of the numerical simulations. The expression derived in this study can be used to estimate the photon production site in relativistic phenomena, e.g., gamma-ray burst and active galactic nuclei.
Kooy, Marcel Jan; Van Geffen, Erica C G; Heerdink, Eibert R; Van Dijk, Liset; Bouvy, Marcel L
2015-06-01
Assess effects of pharmacists' counseling by telephone on patients' satisfaction with counseling, satisfaction with information and beliefs about medicines for newly prescribed medicines. A cluster randomized trial in Dutch community pharmacies. Patients ≥18 years were included when starting with antidepressants, bisphosphonates, RAS-inhibitors or statins. The intervention comprised counseling by telephone to address barriers to adherent behavior. It was supported by an interview protocol. Controls received usual care. Outcomes were effects on beliefs about medication, satisfaction with information and counseling. Data was collected with a questionnaire. Responses of 211 patients in nine pharmacies were analyzed. More intervention arm patients were satisfied with counseling (adj. OR 2.2 (95% CI 1.3, 3.6)). Patients with counseling were significantly more satisfied with information on 4 items, had less concerns and less frequently had a 'skeptical' attitude towards medication (adj. OR 0.5 (0.3-0.9)). Effects on most outcomes were more pronounced in men than in women. Telephone counseling by pharmacists improved satisfaction with counseling and satisfaction with information on some items. It had a small effect on beliefs about medicines. Pharmacists can use counseling by telephone, but more research is needed to find out which patients benefit most. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Access to dental care among 15–64 year old people
Eslamipour, Faezeh; Heydari, Kamal; Ghaiour, Marzieh; Salehi, Hoda
2018-01-01
INTRODUCTION: The current study aims to study people's access to oral and dental health-care services and their satisfaction with the services provided to them. MATERIALS AND METHODS: A descriptive study with multi-stage sampling was conducted on 1360 people aged 16–64 years residing in Isfahan city, Iran. The required data were collected by a questionnaire which comprised of three main parts: demographic characteristics, patients’ access to oral and dental health-care services and its barriers and participants’ satisfaction with access to services. Data were analyzed by SPSS statistical software. RESULTS: The results showed 40% of participants reported an average level for oral health, and 82% of them did not have any problems regarding access to dental care facilities. The main causes of their dissatisfaction were high cost of services (60%) and insufficient health insurance coverage (40%). About 73% reported that they had to spend 30 min or less to access to a dental health-care facility. In addition, 50% of participants were satisfied with the provided services. The main reported reasons for referring to dentists were oral and dental problems (69%) and regular check-ups (15%). There was no significant relationship between participants’ gender, education level, insurance coverage, and access to dental health-care centers (P > 0.05). CONCLUSION: Most participants were satisfied with access to dental healthcare, but they were dissatisfied with the costs and inadequate insurance coverage. About half of the participants were satisfied with the services provided to them, and the highest level of satisfaction was reported for easy access to health-care centers. PMID:29693027
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mobius, P.
1960-05-01
An attempt is raade to treat special translationally invariant many-body problems by coordinate transformations introducing many-particle variables. These are adapted coordinates of such kind that the condition of translational invariance and the Pauli principle can be satisfied automatically. They are homogeneous functions of the particle coordinates obeying certain differential equations. The Schrodinger equation is transformed into these variables. There exist examples of systems of interacting particles which can be separated exactly in the many-particle variables but not in the particle coordinates. (auth)
Electrolytic Removal of Nitrate From CELSS Crop Residues
NASA Technical Reports Server (NTRS)
Colon, Guillermo; Sager, John
1996-01-01
The controlled ecological life support system (CELSS) resource recovery system is a waste processing system using aerobic and anaerobic bioreactors to recover plant nutrients and secondary foods from inedible biomass. Crop residues contain significant amounts of nitrate which presents two problems: (1) both CELSS biomass production and resource recovery consume large quantities of nitric acid, (2) nitrate causes a variety of problems in both aerobic and anaerobic bioreactors. A technique was proposed to remove the nitrate from potato inedible biomass leachate and to satisfy the nitric acid demand using a four compartment electrolytic cell.
NASA Astrophysics Data System (ADS)
2018-05-01
Eigenvalues and eigenvectors, together, constitute the eigenstructure of the system. The design of vibrating systems aimed at satisfying specifications on eigenvalues and eigenvectors, which is commonly known as eigenstructure assignment, has drawn increasing interest over the recent years. The most natural mathematical framework for such problems is constituted by the inverse eigenproblems, which consist in the determination of the system model that features a desired set of eigenvalues and eigenvectors. Although such a problem is intrinsically challenging, several solutions have been proposed in the literature. The approaches to eigenstructure assignment can be basically divided into passive control and active control.
Entropy solutions for a nonlinear parabolic problems with lower order term in Orlicz spaces
NASA Astrophysics Data System (ADS)
Mabdaoui, M.; Moussa, H.; Rhoudaf, M.
2017-03-01
We shall give the proof of existence results for the entropy solutions of the following nonlinear parabolic problem ... where A is a Leray-Lions operator having a growth not necessarily of polynomial type. The lower order term Φ :Ω × (0,T)× R→ R^N is a Carathéodory function, for a.e. (x,t)in Q_T and for all sin R, satisfying only a growth condition and the right hand side f belongs to L^1(Q_T).
Roy-Steiner equations for πN scattering
NASA Astrophysics Data System (ADS)
Ruiz de Elvira, J.; Ditsche, C.; Hoferichter, M.; Kubis, B.; Meißner, U.-G.
2014-06-01
In this talk, we present a coupled system of integral equations for the πN → πN (s-channel) and ππ → N̅N (t-channel) lowest partial waves, derived from Roy-Steiner equations for pion-nucleon scattering. After giving a brief overview of this system of equations, we present the solution of the t-channel sub-problem by means of Muskhelishvili-Omnès techniques, and solve the s-channel sub-problem after finding a set of phase shifts and subthreshold parameters which satisfy the Roy-Steiner equations.
Satisfying positivity requirement in the Beyond Complex Langevin approach
NASA Astrophysics Data System (ADS)
Wyrzykowski, Adam; Ruba, Błażej Ruba
2018-03-01
The problem of finding a positive distribution, which corresponds to a given complex density, is studied. By the requirement that the moments of the positive distribution and of the complex density are equal, one can reduce the problem to solving the matching conditions. These conditions are a set of quadratic equations, thus Groebner basis method was used to find its solutions when it is restricted to a few lowest-order moments. For a Gaussian complex density, these approximate solutions are compared with the exact solution, that is known in this special case.
A modify ant colony optimization for the grid jobs scheduling problem with QoS requirements
NASA Astrophysics Data System (ADS)
Pu, Xun; Lu, XianLiang
2011-10-01
Job scheduling with customers' quality of service (QoS) requirement is challenging in grid environment. In this paper, we present a modify Ant colony optimization (MACO) for the Job scheduling problem in grid. Instead of using the conventional construction approach to construct feasible schedules, the proposed algorithm employs a decomposition method to satisfy the customer's deadline and cost requirements. Besides, a new mechanism of service instances state updating is embedded to improve the convergence of MACO. Experiments demonstrate the effectiveness of the proposed algorithm.
Frischer, Robert; Penhaker, Marek; Krejcar, Ondrej; Kacerovsky, Marian; Selamat, Ali
2014-01-01
Precise temperature measurement is essential in a wide range of applications in the medical environment, however the regarding the problem of temperature measurement inside a simple incubator, neither a simple nor a low cost solution have been proposed yet. Given that standard temperature sensors don't satisfy the necessary expectations, the problem is not measuring temperature, but rather achieving the desired sensitivity. In response, this paper introduces a novel hardware design as well as the implementation that increases measurement sensitivity in defined temperature intervals at low cost. PMID:25494352
A quantum heuristic algorithm for the traveling salesman problem
NASA Astrophysics Data System (ADS)
Bang, Jeongho; Ryu, Junghee; Lee, Changhyoup; Yoo, Seokwon; Lim, James; Lee, Jinhyoung
2012-12-01
We propose a quantum heuristic algorithm to solve the traveling salesman problem by generalizing the Grover search. Sufficient conditions are derived to greatly enhance the probability of finding the tours with the cheapest costs reaching almost to unity. These conditions are characterized by the statistical properties of tour costs and are shown to be automatically satisfied in the large-number limit of cities. In particular for a continuous distribution of the tours along the cost, we show that the quantum heuristic algorithm exhibits a quadratic speedup compared to its classical heuristic algorithm.
ERIC Educational Resources Information Center
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…
Steinhaus’ Geometric Location Problem for Random Samples in the Plane.
1982-05-11
NAL 411R A1, ’I 7 - I STEINHAUS ’ GEOMETRIC LOCATION PROBLEM FOR RANDOM SAMPLES IN THE PLANE By Dorit Hochbaum and J. Michael Steele TECHNICAL REPORT...DEPARTMENT OF STATISTICS -Dltrib’ytion/ STANFORD UNIVERSITY A-I.abilty Codes STANFORD, CALIFORNIA Dist Spciat ecial Steinhaus ’ Geometric Location Problem for...Random Samples in the Plane By Dorit Hochbaum and J. Michael Steele I. Introduction. The work of H. Steinhaus U wf94 as apparently the first explicit
DeFoor, William; Reddy, Pramod; Reed, Melissa; VanderBrink, Brian; Jackson, Elizabeth; Zhang, Bin; Denlinger, Julie; Noh, Paul; Minevich, Eugene; Sheldon, Curtis
2017-08-01
Children with neurogenic bladder (NGB) often require a lifetime of clean intermittent catheterization (CIC), typically using uncoated catheters (UCs). Hydrophilic catheters (HCs) have lower friction than UCs with reported less damage to the urethra. The purpose of this study is to compare outcomes between these catheters. An investigator-initiated, prospective, randomized clinical trial was conducted to compare HCs versus UCs. Children aged 2-17 years with NGB on CIC were enrolled for 1 year. Block randomization was used. Dexterity scores were obtained in those who perform self-catheterization. Outcomes were UTI, difficulty passing the catheter, urethral injury, and patient satisfaction. Demographic data is presented in the Table. Seventy-eight patients were enrolled. Age and gender were similar between the groups. Fifteen patients in each group performed CIC via an abdominal wall stoma. Eight and 15 patients withdrew from the UC and HC groups, respectively. The HC group overall had more problems with the catheter, mainly difficulty with handling. There were no differences for passing the catheter, pain, hematuria, or urethral injuries. There were two urinary tract infections (UTIs) in two HC patients and 17 UTIs in seven UC patients (p = 0.003). Patients with UTIs in the HC group went from 16% in the previous year to 5% during the study. Three children in the HC group had three or more UTIs in the year before enrollment and none during the study. The patients that completed the study with HC were overall satisfied and many requested to continue with the HC. HCs may decrease the risk of UTI in children with NGB. Urethral complications were low in both groups. Most HC patients were pleased but some found the slippery coating difficult to handle. Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Gilliam, Melissa L; Martins, Summer L; Bartlett, Emily; Mistretta, Stephanie Q; Holl, Jane L
2014-11-01
Long-acting reversible contraceptive (LARC) methods, such as the intrauterine device and implant, are highly effective but used by less than 10% of US women. The objective of our study was to improve LARC interest by enhancing clinic counseling. A quality improvement methodology was used to evaluate intrauterine device service delivery in 3 Chicago Title X clinics. To address identified barriers, we developed a theory-based iOS application (app) for patients to use in the clinic waiting room using human-centered design. The final prototype was tested in a randomized controlled trial in a Title X clinic with sexually active females (79% African American) under age 30 years. Our sample of 60 was chosen to detect an increase from 10% (baseline) to 45% (app intervention) in the proportion of patients expressing interest in discussing a LARC method during their clinic visit with 80% power and two-sided α = 0.05. After completing demographic and baseline knowledge questionnaires, participants were randomized 1:1 to intervention (app) or standard care arms. App users also completed a posttest. Our primary outcome was expressed interest in discussing a LARC method during the clinic visit. Secondary outcomes were contraceptive knowledge and LARC selection. App testers (n = 17) preferred interactive, visually appealing design and video testimonials. In the pilot randomized controlled trial (n = 52), app users had a significantly higher knowledge of contraceptive effectiveness (P = .0001) and increased interest in the implant (7.1-32.1%, P = .02) after the intervention. Users were highly satisfied with the app. Staff reported no problems using the app in the clinic. Use of a theory-based counseling app offers a novel method to optimize wait time while minimizing clinic flow disruption. Preliminary data demonstrate that app use was associated with improvements in patients' contraceptive knowledge and interest in the implant. Copyright © 2014 Elsevier Inc. All rights reserved.
Adaptive Techniques for Control of Large Space Structures.
1984-12-01
uncertainty, diverge and ultimately go unstable. This problem is extremely difficult and has only recently been addressed, even in the general context of...L. (4.7b) Corollary 1: Performance Bounds Suppose z. and e. satisfy the conditions in () of Theroems 1A or 18. I) Let H c SPR , i.e., - M, y > 0 such
ERIC Educational Resources Information Center
Keuthen, Nancy J.; Flessner, Christopher A.; Woods, Douglas W.; Franklin, Martin E.; Piacentini, John A.; Khanna, Muniya; Moore, Phoebe; Cashin, Susan
2008-01-01
Knowledge of cross-informant rating concordance is critical for the assessment of child and adolescent problems in clinical and research settings. We explored parent-youth rating concordance for hair pulling variables, functional impairment, and anxiety symptoms in a sample of child and adolescent hair pullers (n = 133) satisfying conservative…
ERIC Educational Resources Information Center
Epps, Rebekah B.; Foor, Ryan M.
2015-01-01
The teacher shortage in the United States is a continuous problem for the American education system. Maintaining a high level of job satisfaction of teachers is an important goal for administrators, superintendents, and school systems. Employees who are more satisfied are generally more productive and committed to the profession. Beliefs in…
'Footballs', conical singularities, and the Liouville equation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Redi, Michele
We generalize the football shaped extra dimensions scenario to an arbitrary number of branes. The problem is related to the solution of the Liouville equation with singularities, and explicit solutions are presented for the case of three branes. The tensions of the branes do not need to be tuned with each other but only satisfy mild global constraints.
ERIC Educational Resources Information Center
Field, M. J.; Harrison, A. B.
Quality circles attempt to satisfy both task and personal needs through staff involvement in solving work-related problems. This paper summarizes quality circle theory, applies it to school settings, and suggests a framework for introducing the process to educational institutions. After briefly defining quality circles, the article presents two…
Using Technology's Internet Resources in Algebra 1
ERIC Educational Resources Information Center
Crespo, Irma S. Z. B.
2009-01-01
Technology is a means that makes work or tasks easy, efficient, and operative. A more encompassing definition refers to it "as the tools created by human knowledge of how to combine resources to produce desired products, to solve problems, fulfill needs, or satisfy wants" (Koehler and Mishra. 2008:5). It can either be contrivances of tradition or…
Computations of Aerodynamic Performance Databases Using Output-Based Refinement
NASA Technical Reports Server (NTRS)
Nemec, Marian; Aftosmis, Michael J.
2009-01-01
Objectives: Handle complex geometry problems; Control discretization errors via solution-adaptive mesh refinement; Focus on aerodynamic databases of parametric and optimization studies: 1. Accuracy: satisfy prescribed error bounds 2. Robustness and speed: may require over 105 mesh generations 3. Automation: avoid user supervision Obtain "expert meshes" independent of user skill; and Run every case adaptively in production settings.
A problem in non-linear Diophantine approximation
NASA Astrophysics Data System (ADS)
Harrap, Stephen; Hussain, Mumtaz; Kristensen, Simon
2018-05-01
In this paper we obtain the Lebesgue and Hausdorff measure results for the set of vectors satisfying infinitely many fully non-linear Diophantine inequalities. The set is associated with a class of linear inhomogeneous partial differential equations whose solubility depends on a certain Diophantine condition. The failure of the Diophantine condition guarantees the existence of a smooth solution.
Barriers to Equality of Access to Educational Opportunity in Nigeria: A Philosophical Perspective
ERIC Educational Resources Information Center
Nwogu, Godpower Anyalebechi Ikechi
2015-01-01
Education as well as its objective are dynamic instruments needed to meet and satisfy the aspirations of the citizens they are meant to serve. Limited resources and a rapidly expanding child population pose problems of "who gets educated" in Nigeria. The question of educational imbalance has been a dominant issue which subsequent…
Numerical modeling of divergent detonation wave
NASA Astrophysics Data System (ADS)
Li, Zhiwei; Liu, Bangdi
1987-11-01
The indefinite nature of divergent detonations under the assumption of instantaneous stable detonation is described. In the numerical modeling method for divergent detonation, the artificial cohesiveness was improved and the Cochran reaction rate and the JWL equations of state were used to describe the ignition process of the explosion. Several typical divergent detonation problems were computed obtaining rather satisfying results.
Educational Testing as a Technology. NBETPP Statements, Volume 2, Number 1.
ERIC Educational Resources Information Center
Madaus, George F.
The term "technology" often conjures up visions of scientific experiments and industrial processes, but technology is also a tool, something put together to satisfy a need, solve a problem, or attain a goal in social, economic, and educational institutions. In a broader sense, technology is any body of special knowledge, skills, and procedures,…
Effective Numerical Methods for Solving Elliptical Problems in Strengthened Sobolev Spaces
NASA Technical Reports Server (NTRS)
D'yakonov, Eugene G.
1996-01-01
Fourth-order elliptic boundary value problems in the plane can be reduced to operator equations in Hilbert spaces G that are certain subspaces of the Sobolev space W(sub 2)(exp 2)(Omega) is identical with G(sup (2)). Appearance of asymptotically optimal algorithms for Stokes type problems made it natural to focus on an approach that considers rot w is identical with (D(sub 2)w - D(sub 1)w) is identical with vector of u as a new unknown vector-function, which automatically satisfies the condition div vector of u = 0. In this work, we show that this approach can also be developed for an important class of problems from the theory of plates and shells with stiffeners. The main mathematical problem was to show that the well-known inf-sup condition (normal solvability of the divergence operator) holds for special Hilbert spaces. This result is also essential for certain hydrodynamics problems.
Distance estimation and collision prediction for on-line robotic motion planning
NASA Technical Reports Server (NTRS)
Kyriakopoulos, K. J.; Saridis, G. N.
1991-01-01
An efficient method for computing the minimum distance and predicting collisions between moving objects is presented. This problem has been incorporated in the framework of an in-line motion planning algorithm to satisfy collision avoidance between a robot and moving objects modeled as convex polyhedra. In the beginning the deterministic problem, where the information about the objects is assumed to be certain is examined. If instead of the Euclidean norm, L(sub 1) or L(sub infinity) norms are used to represent distance, the problem becomes a linear programming problem. The stochastic problem is formulated, where the uncertainty is induced by sensing and the unknown dynamics of the moving obstacles. Two problems are considered: (1) filtering of the minimum distance between the robot and the moving object, at the present time; and (2) prediction of the minimum distance in the future, in order to predict possible collisions with the moving obstacles and estimate the collision time.
Asymmetrically dominated choice problems, the isolation hypothesis and random incentive mechanisms.
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.
Serang, Oliver
2012-01-01
Linear programming (LP) problems are commonly used in analysis and resource allocation, frequently surfacing as approximations to more difficult problems. Existing approaches to LP have been dominated by a small group of methods, and randomized algorithms have not enjoyed popularity in practice. This paper introduces a novel randomized method of solving LP problems by moving along the facets and within the interior of the polytope along rays randomly sampled from the polyhedral cones defined by the bounding constraints. This conic sampling method is then applied to randomly sampled LPs, and its runtime performance is shown to compare favorably to the simplex and primal affine-scaling algorithms, especially on polytopes with certain characteristics. The conic sampling method is then adapted and applied to solve a certain quadratic program, which compute a projection onto a polytope; the proposed method is shown to outperform the proprietary software Mathematica on large, sparse QP problems constructed from mass spectometry-based proteomics. PMID:22952741
Black hole thermodynamics from a variational principle: asymptotically conical backgrounds
An, Ok Song; Cvetič, Mirjam; Papadimitriou, Ioannis
2016-03-14
The variational problem of gravity theories is directly related to black hole thermodynamics. For asymptotically locally AdS backgrounds it is known that holographic renormalization results in a variational principle in terms of equivalence classes of boundary data under the local asymptotic symmetries of the theory, which automatically leads to finite conserved charges satisfying the first law of thermodynamics. We show that this connection holds well beyond asymptotically AdS black holes. In particular, we formulate the variational problem for N = 2 STU supergravity in four dimensions with boundary conditions corresponding to those obeyed by the so called ‘subtracted geometries’. Wemore » show that such boundary conditions can be imposed covariantly in terms of a set of asymptotic second class constraints, and we derive the appropriate boundary terms that render the variational problem well posed in two different duality frames of the STU model. This allows us to define finite conserved charges associated with any asymptotic Killing vector and to demonstrate that these charges satisfy the Smarr formula and the first law of thermodynamics. Moreover, by uplifting the theory to five dimensions and then reducing on a 2-sphere, we provide a precise map between the thermodynamic observables of the subtracted geometries and those of the BTZ black hole. Finally, surface terms play a crucial role in this identification.« less
Black hole thermodynamics from a variational principle: asymptotically conical backgrounds
DOE Office of Scientific and Technical Information (OSTI.GOV)
An, Ok Song; Cvetič, Mirjam; Papadimitriou, Ioannis
The variational problem of gravity theories is directly related to black hole thermodynamics. For asymptotically locally AdS backgrounds it is known that holographic renormalization results in a variational principle in terms of equivalence classes of boundary data under the local asymptotic symmetries of the theory, which automatically leads to finite conserved charges satisfying the first law of thermodynamics. We show that this connection holds well beyond asymptotically AdS black holes. In particular, we formulate the variational problem for N = 2 STU supergravity in four dimensions with boundary conditions corresponding to those obeyed by the so called ‘subtracted geometries’. Wemore » show that such boundary conditions can be imposed covariantly in terms of a set of asymptotic second class constraints, and we derive the appropriate boundary terms that render the variational problem well posed in two different duality frames of the STU model. This allows us to define finite conserved charges associated with any asymptotic Killing vector and to demonstrate that these charges satisfy the Smarr formula and the first law of thermodynamics. Moreover, by uplifting the theory to five dimensions and then reducing on a 2-sphere, we provide a precise map between the thermodynamic observables of the subtracted geometries and those of the BTZ black hole. Finally, surface terms play a crucial role in this identification.« less
Evaluation of Patient’s Personal Reasons and Experience with Orthodontic Treatment
Sharma, Sandeep; Narkhede, Sameer; Sonawane, Shushma; Gangurde, Parag
2013-01-01
Background: The objective of the study is to evaluate patient’s personal reasons and experience with orthodontic treatment. Also to find the problems faced during the orthodontic procedure. Materials & Methods: A cross-sectional study was done using pretested questionnaire among 312 patients (178 – males and 134 – females) with a response rate of 85%. The overall mean age of the population was 21.34±62 years. The data was collected on excel sheet and analyzed by SPSS 15.0 software at p value 0.05 for the statistical significance. Results: Half of the participants (52.4%) had undergone orthodontic procedure for straightening the teeth as they think that teeth are the important features that affect the facial profile. Around fifty percent judged themselves that they require this procedure. Most common problem faced by the participants during treatment was its longer duration (29.3%). Still 86.4% of them were satisfied with the treatment. Conclusion: The study concluded most of the subjects themselves noted that they are in need of orthodontic treatment in them. There were many problems faced during the procedure by the participants but still most of them were satisfied after the results. How to cite this article: Sharma S, Narkhede S, Sonawane S, Gangurde P. Evaluation of Patient’s Personal Reasons and Experience with Orthodontic Treatment. J Int Oral Health 2013; 5(6):78-81 . PMID:24453449
Decision support system for the operating room rescheduling problem.
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.
Inverse random source scattering for the Helmholtz equation in inhomogeneous media
NASA Astrophysics Data System (ADS)
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.
Chen, Fa-Ming; Gao, Li-Na; Tian, Bei-Min; Zhang, Xi-Yu; Zhang, Yong-Jie; Dong, Guang-Ying; Lu, Hong; Chu, Qing; Xu, Jie; Yu, Yang; Wu, Rui-Xin; Yin, Yuan; Shi, Songtao; Jin, Yan
2016-02-19
Periodontitis, which progressively destroys tooth-supporting structures, is one of the most widespread infectious diseases and the leading cause of tooth loss in adults. Evidence from preclinical trials and small-scale pilot clinical studies indicates that stem cells derived from periodontal ligament tissues are a promising therapy for the regeneration of lost/damaged periodontal tissue. This study assessed the safety and feasibility of using autologous periodontal ligament stem cells (PDLSCs) as an adjuvant to grafting materials in guided tissue regeneration (GTR) to treat periodontal intrabony defects. Our data provide primary clinical evidence for the efficacy of cell transplantation in regenerative dentistry. We conducted a single-center, randomized trial that used autologous PDLSCs in combination with bovine-derived bone mineral materials to treat periodontal intrabony defects. Enrolled patients were randomly assigned to either the Cell group (treatment with GTR and PDLSC sheets in combination with Bio-oss(®)) or the Control group (treatment with GTR and Bio-oss(®) without stem cells). During a 12-month follow-up study, we evaluated the frequency and extent of adverse events. For the assessment of treatment efficacy, the primary outcome was based on the magnitude of alveolar bone regeneration following the surgical procedure. A total of 30 periodontitis patients aged 18 to 65 years (48 testing teeth with periodontal intrabony defects) who satisfied our inclusion and exclusion criteria were enrolled in the study and randomly assigned to the Cell group or the Control group. A total of 21 teeth were treated in the Control group and 20 teeth were treated in the Cell group. All patients received surgery and a clinical evaluation. No clinical safety problems that could be attributed to the investigational PDLSCs were identified. Each group showed a significant increase in the alveolar bone height (decrease in the bone-defect depth) over time (p < 0.001). However, no statistically significant differences were detected between the Cell group and the Control group (p > 0.05). This study demonstrates that using autologous PDLSCs to treat periodontal intrabony defects is safe and does not produce significant adverse effects. The efficacy of cell-based periodontal therapy requires further validation by multicenter, randomized controlled studies with an increased sample size. NCT01357785 Date registered: 18 May 2011.
The statistics of Pearce element diagrams and the Chayes closure problem
NASA Astrophysics Data System (ADS)
Nicholls, J.
1988-05-01
Pearce element ratios are defined as having a constituent in their denominator that is conserved in a system undergoing change. The presence of a conserved element in the denominator simplifies the statistics of such ratios and renders them subject to statistical tests, especially tests of significance of the correlation coefficient between Pearce element ratios. Pearce element ratio diagrams provide unambigous tests of petrologic hypotheses because they are based on the stoichiometry of rock-forming minerals. There are three ways to recognize a conserved element: 1. The petrologic behavior of the element can be used to select conserved ones. They are usually the incompatible elements. 2. The ratio of two conserved elements will be constant in a comagmatic suite. 3. An element ratio diagram that is not constructed with a conserved element in the denominator will have a trend with a near zero intercept. The last two criteria can be tested statistically. The significance of the slope, intercept and correlation coefficient can be tested by estimating the probability of obtaining the observed values from a random population of arrays. This population of arrays must satisfy two criteria: 1. The population must contain at least one array that has the means and variances of the array of analytical data for the rock suite. 2. Arrays with the means and variances of the data must not be so abundant in the population that nearly every array selected at random has the properties of the data. The population of random closed arrays can be obtained from a population of open arrays whose elements are randomly selected from probability distributions. The means and variances of these probability distributions are themselves selected from probability distributions which have means and variances equal to a hypothetical open array that would give the means and variances of the data on closure. This hypothetical open array is called the Chayes array. Alternatively, the population of random closed arrays can be drawn from the compositional space available to rock-forming processes. The minerals comprising the available space can be described with one additive component per mineral phase and a small number of exchange components. This space is called Thompson space. Statistics based on either space lead to the conclusion that Pearce element ratios are statistically valid and that Pearce element diagrams depict the processes that create chemical inhomogeneities in igneous rock suites.
What Does a Random Line Look Like: An Experimental Study
ERIC Educational Resources Information Center
Turner, Nigel E.; Liu, Eleanor; Toneatto, Tony
2011-01-01
The study examined the perception of random lines by people with gambling problems compared to people without gambling problems. The sample consisted of 67 probable pathological gamblers and 46 people without gambling problems. Participants completed a number of questionnaires about their gambling and were then presented with a series of random…
Han, Kihye; Trinkoff, Alison M; Gurses, Ayse P
2015-11-01
To examine the relationships of work-related factors (e.g., autonomy, work schedule, supervisory and peer support) to nurses' job satisfaction and intent to leave their current position. Low job satisfaction and high turnover of nurses are major problems for health care. To improve nurse retention, work-related factors associated with job satisfaction and intent to leave should be investigated. A cross-sectional secondary data analysis. Data were obtained in 2004 from Wave 3 of the Nurses' Worklife and Health Study. A random sample of 5000 actively licenced nurses in Illinois and North Carolina (two U.S. states) were sent the survey in wave 1, of which 1641 actively working bedside nurses participated in wave 3. We examined associations of various work-related factors with job satisfaction and intent to leave the current position. Nurses who were dissatisfied with their job reported significantly higher psychological demands and lower autonomy than nurses who were satisfied. Nurses were significantly less satisfied with their jobs when they worked longer hours with inadequate breaks or sick days. Lack of support from peers and supervisors was also related to significantly lower odds of job satisfaction. For intention to leave, nurses who said they planned to leave their current job reported significantly lower autonomy and less support from their peers than nurses who intended to stay. A variety of modifiable work-related factors were significantly related to job satisfaction and intention to leave the current job among nurses. Future research should focus on developing interventions that could mitigate these factors (e.g., by improving work schedules, increasing autonomy and/or nurse support). The impact of such interventions on job satisfaction and intention to leave the current position could then be evaluated. To increase nurse retention, improved schedules, autonomy and supportive work environments should be promoted. © 2015 John Wiley & Sons Ltd.
Disk Density Tuning of a Maximal Random Packing
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.
2016-01-01
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. PMID:27563162
Disk Density Tuning of a Maximal Random Packing.
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.
Accumulator and random-walk models of psychophysical discrimination: a counter-evaluation.
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.
A chance-constrained stochastic approach to intermodal container routing problems.
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.
A chance-constrained stochastic approach to intermodal container routing problems
Zhao, Yi; 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. PMID:29438389
Locating CVBEM collocation points for steady state heat transfer problems
Hromadka, T.V.
1985-01-01
The Complex Variable Boundary Element Method or CVBEM provides a highly accurate means of developing numerical solutions to steady state two-dimensional heat transfer problems. The numerical approach exactly solves the Laplace equation and satisfies the boundary conditions at specified points on the boundary by means of collocation. The accuracy of the approximation depends upon the nodal point distribution specified by the numerical analyst. In order to develop subsequent, refined approximation functions, four techniques for selecting additional collocation points are presented. The techniques are compared as to the governing theory, representation of the error of approximation on the problem boundary, the computational costs, and the ease of use by the numerical analyst. ?? 1985.
Optimal control problems with mixed control-phase variable equality and inequality constraints
NASA Technical Reports Server (NTRS)
Makowski, K.; Neustad, L. W.
1974-01-01
In this paper, necessary conditions are obtained for optimal control problems containing equality constraints defined in terms of functions of the control and phase variables. The control system is assumed to be characterized by an ordinary differential equation, and more conventional constraints, including phase inequality constraints, are also assumed to be present. Because the first-mentioned equality constraint must be satisfied for all t (the independent variable of the differential equation) belonging to an arbitrary (prescribed) measurable set, this problem gives rise to infinite-dimensional equality constraints. To obtain the necessary conditions, which are in the form of a maximum principle, an implicit-function-type theorem in Banach spaces is derived.
Developing optimal nurses work schedule using integer programming
NASA Astrophysics Data System (ADS)
Shahidin, Ainon Mardhiyah; Said, Mohd Syazwan Md; Said, Noor Hizwan Mohamad; Sazali, Noor Izatie Amaliena
2017-08-01
Time management is the art of arranging, organizing and scheduling one's time for the purpose of generating more effective work and productivity. Scheduling is the process of deciding how to commit resources between varieties of possible tasks. Thus, it is crucial for every organization to have a good work schedule for their staffs. The job of Ward nurses at hospitals runs for 24 hours every day. Therefore, nurses will be working using shift scheduling. This study is aimed to solve the nurse scheduling problem at an emergency ward of a private hospital. A 7-day work schedule for 7 consecutive weeks satisfying all the constraints set by the hospital will be developed using Integer Programming. The work schedule for the nurses obtained gives an optimal solution where all the constraints are being satisfied successfully.
An RBF-based reparameterization method for constrained texture mapping.
Yu, Hongchuan; Lee, Tong-Yee; Yeh, I-Cheng; Yang, Xiaosong; Li, Wenxi; Zhang, Jian J
2012-07-01
Texture mapping has long been used in computer graphics to enhance the realism of virtual scenes. However, to match the 3D model feature points with the corresponding pixels in a texture image, surface parameterization must satisfy specific positional constraints. However, despite numerous research efforts, the construction of a mathematically robust, foldover-free parameterization that is subject to positional constraints continues to be a challenge. In the present paper, this foldover problem is addressed by developing radial basis function (RBF)-based reparameterization. Given initial 2D embedding of a 3D surface, the proposed method can reparameterize 2D embedding into a foldover-free 2D mesh, satisfying a set of user-specified constraint points. In addition, this approach is mesh free. Therefore, generating smooth texture mapping results is possible without extra smoothing optimization.
NASA Astrophysics Data System (ADS)
Ghosh, Uttam; Banerjee, Joydip; Sarkar, Susmita; Das, Shantanu
2018-06-01
Klein-Gordon equation is one of the basic steps towards relativistic quantum mechanics. In this paper, we have formulated fractional Klein-Gordon equation via Jumarie fractional derivative and found two types of solutions. Zero-mass solution satisfies photon criteria and non-zero mass satisfies general theory of relativity. Further, we have developed rest mass condition which leads us to the concept of hidden wave. Classical Klein-Gordon equation fails to explain a chargeless system as well as a single-particle system. Using the fractional Klein-Gordon equation, we can overcome the problem. The fractional Klein-Gordon equation also leads to the smoothness parameter which is the measurement of the bumpiness of space. Here, by using this smoothness parameter, we have defined and interpreted the various cases.
[THE ACTUAL APPROACHES TO PROBLEM OF IMPORT SUBSTITUTION IN TH FIELD OF PRODUCTION GROWTH MEDIUM].
Shepelin, A P; Domotenko, L V; Diatlov, I A; Mironov, A Yu; Aleshkin, V A
2015-06-01
The import substitution becomes one of strategic tasks of Russian economy as a result of imposition of economic sanctions on part of the USA, EU countries, Japan and number of other states. The development of structure and technology of production of national import substituted growth mediums permits satisfying needs of laboratory service of Russia inactive storage and to secure appropriate response to occurring challenges and new biological menaces and support bio-security of state at proper level. The presented data concerning substantiation of nomenclature of growth mediums and transport system permit satisfying in fullness the needs of clinical and sanitary microbiology in growth mediums of national production and to give up of import deliveries without decreasing of quality of microbiological studies.
A Benders based rolling horizon algorithm for a dynamic facility location problem
Marufuzzaman,, Mohammad; Gedik, Ridvan; Roni, Mohammad S.
2016-06-28
This study presents a well-known capacitated dynamic facility location problem (DFLP) that satisfies the customer demand at a minimum cost by determining the time period for opening, closing, or retaining an existing facility in a given location. To solve this challenging NP-hard problem, this paper develops a unique hybrid solution algorithm that combines a rolling horizon algorithm with an accelerated Benders decomposition algorithm. Extensive computational experiments are performed on benchmark test instances to evaluate the hybrid algorithm’s efficiency and robustness in solving the DFLP problem. Computational results indicate that the hybrid Benders based rolling horizon algorithm consistently offers high qualitymore » feasible solutions in a much shorter computational time period than the standalone rolling horizon and accelerated Benders decomposition algorithms in the experimental range.« less
Boundary layer flow of air over water on a flat plate
NASA Technical Reports Server (NTRS)
Nelson, John; Alving, Amy E.; Joseph, Daniel D.
1993-01-01
A non-similar boundary layer theory for air blowing over a water layer on a flat plate is formulated and studied as a two-fluid problem in which the position of the interface is unknown. The problem is considered at large Reynolds number (based on x), away from the leading edge. A simple non-similar analytic solution of the problem is derived for which the interface height is proportional to x(sub 1/4) and the water and air flow satisfy the Blasius boundary layer equations, with a linear profile in the water and a Blasius profile in the air. Numerical studies of the initial value problem suggests that this asymptotic, non-similar air-water boundary layer solution is a global attractor for all initial conditions.
Effect of interfacial stresses in an elastic body with a nanoinclusion
NASA Astrophysics Data System (ADS)
Vakaeva, Aleksandra B.; Grekov, Mikhail A.
2018-05-01
The 2-D problem of an infinite elastic solid with a nanoinclusion of a different from circular shape is solved. The interfacial stresses are acting at the interface. Contact of the inclusion with the matrix satisfies the ideal conditions of cohesion. The generalized Laplace - Young law defines conditions at the interface. To solve the problem, Gurtin - Murdoch surface elasticity model, Goursat - Kolosov complex potentials and the boundary perturbation method are used. The problem is reduced to the solution of two independent Riemann - Hilbert's boundary problems. For the circular inclusion, hypersingular integral equation in an unknown interfacial stress is derived. The algorithm of solving this equation is constructed. The influence of the interfacial stress and the dimension of the circular inclusion on the stress distribution and stress concentration at the interface are analyzed.
1986-03-04
satisfied, but the availability of the machinery will entice developments to appear over the next few years. TABULATION AND DISPLAY To gain access to...independent, identicallyof the optimal predictor and the mean square distributed random variables with mean 0 and difference between the optimal forecast... optimal forecast (the conditional mean of YT+, given qute approximation to a2 1 j For the% Yl ~ ~ ~ ~ ~ ~ ~ . ... ,FT) thehtm-[ ]# rn-1 Y1...;,YT) and
A design methodology for nonlinear systems containing parameter uncertainty
NASA Technical Reports Server (NTRS)
Young, G. E.; Auslander, D. M.
1983-01-01
In the present design methodology for nonlinear systems containing parameter uncertainty, a generalized sensitivity analysis is incorporated which employs parameter space sampling and statistical inference. For the case of a system with j adjustable and k nonadjustable parameters, this methodology (which includes an adaptive random search strategy) is used to determine the combination of j adjustable parameter values which maximize the probability of those performance indices which simultaneously satisfy design criteria in spite of the uncertainty due to k nonadjustable parameters.
Sur les processus linéaires de naissance et de mort sous-critiques dans un environnement aléatoire.
Bacaër, Nicolas
2017-07-01
An explicit formula is found for the rate of extinction of subcritical linear birth-and-death processes in a random environment. The formula is illustrated by numerical computations of the eigenvalue with largest real part of the truncated matrix for the master equation. The generating function of the corresponding eigenvector satisfies a Fuchsian system of singular differential equations. A particular attention is set on the case of two environments, which leads to Riemann's differential equation.
Statistical Mechanics of Combinatorial Auctions
NASA Astrophysics Data System (ADS)
Galla, Tobias; Leone, Michele; Marsili, Matteo; Sellitto, Mauro; Weigt, Martin; Zecchina, Riccardo
2006-09-01
Combinatorial auctions are formulated as frustrated lattice gases on sparse random graphs, allowing the determination of the optimal revenue by methods of statistical physics. Transitions between computationally easy and hard regimes are found and interpreted in terms of the geometric structure of the space of solutions. We introduce an iterative algorithm to solve intermediate and large instances, and discuss competing states of optimal revenue and maximal number of satisfied bidders. The algorithm can be generalized to the hard phase and to more sophisticated auction protocols.
Dynamic pluralism: A pluralist framework for science
NASA Astrophysics Data System (ADS)
Ferret, Juan
The problem of measurement in quantum physics is one of the most recalcitrant problems of science. Part of the problem lies in the fact that several conflicting interpretations that account for how measurement takes place have endured. Most theorists of science assume that one of the available interpretations, or a future variation of one, will prove to be the true interpretation. What I argue in this dissertation is that the proper response to this problem may be to have a framework in which different relevant interpretations can coexist and offer critical examinations of the conceptual issues related to the problem of measurement. This pluralism of interpretations is not the result of some flaw or inadequacy in quantum physics. From this alternative framework, pluralism in the problem of measurement can be understood as an acceptable, even necessary, response to the process of theorizing and experimentation in quantum mechanics. An important claim in this dissertation is that contemporary versions of pluralism in philosophy of science do not provide an account that recognizes the viability of all the interpretations of the problem of measurement. After showing how these versions of pluralism in philosophy of science fall short, as they apply to the problem of measurement, I argue for several conditions that a pluralism needs to satisfy in order to serve as a pluralistic framework for the evaluation of all interpretations of the problem of measurement. I develop an alternative version of pluralism that does account for the existing and future plurality of interpretations of the problem of measurement. My proposal is that a version of pluralism based on the work of William James and Paul Feyerabend will meet these conditions. Specifically, after introducing the complex pluralism of James as a version of pluralism that comes close to accounting for the multiplicity of interpretations of the problem of measurement, I argue that his version of pluralism does not fulfill a few of the necessary conditions. Next, I use the work on pluralism of Feyerabend to fill in the lacunas left in James's account. Finally, I show how the emerging pluralist framework, what I term dynamic pluralism, satisfies the conditions for a pluralism that can serve as a framework for understanding all of the possible interpretations of the problem of measurement.
Diaz-Perez, Julio A; Raju, Sharat; Echeverri, Jorge H
2014-01-01
Learning pathology is fundamental for a successful medical practice. In recent years, medical education has undergone a profound transformation toward the development of an integrated curriculum incorporating both basic science and clinical material. Simultaneously, there has been a shift from a magisterial teaching approach to one centered around problem-based learning. Now-a-days, informatics tools are expected to help better implement these strategies. We applied and evaluated a new teaching method based on an active combination of clinical problems, gross pathology, histopathology, and autopsy pathology, all given through informatics tools, to teach a group of medical students at the Universidad de Santander, Colombia. Ninety-four medical students were followed in two consecutive semesters. Students were randomized to receive teaching either through traditional methodology or through the new integrated approach. There was no significant difference between the intervention group and the control group at baseline. At the end of the study, the scores in the intervention group were significantly higher compared to the control group (3.91/5.0 vs. 3.33/5.0, P = 0.0008). Students and tutors endorsed the benefits of the integrated approach. Participants were very satisfied with this training approach and rated the program an 8.7 out of 10, on average. This study confirms that an integrated curriculum utilizing informatics systems provides an excellent opportunity to associate pathology with clinical medicine early in training of medical students. This can be possible with the use of virtual microscopy and digital imaging.
A comparison of free-stall barns used by modernized Wisconsin dairies.
Bewley, J; Palmer, R W; Jackson-Smith, D B
2001-02-01
A primary objective of the Wisconsin Dairy Modernization Survey was to compare features of free-stall barns available to dairy producers. This study used data from a large random sample of expanding dairy farms to determine whether the theoretical benefits of particular free-stall configurations bear out under on-farm conditions. Comparisons were made among herds using free-stall barns as their primary housing for new versus remodeled facilities, barn design, bedding used, feed-delivery design, manure removal strategies, animal restraint, maternity areas, overcrowding, and cooling methods. Producers who made the transition from tie-stall housing to free-stall housing were satisfied with this decision. New free-stall barns provided a more desirable environment for the herds than remodeled free-stall barns, although initial investments were higher. When new free-stall barns were compared, herds with four-row barns had higher production, lower somatic cell count, and higher stocking rates than herds with six-row barns. Respondents were more satisfied with four- and six-row barns than with two- and three-row barns. Respondents felt sand provided some advantages for cow comfort, while satisfaction with bedding cost and manure handling was higher with mattresses. Dairy Herd Improvement data showed no difference in milk production or somatic cell count for producers who chose sand or mattress-based free stalls. Respondents were more satisfied with the use of drive-through feeding than other feed-delivery designs. Most producers chose to use tractor scrapers to remove manure; however, producers who used automated systems were more satisfied with manure management. Few differences were observed when comparing self-locking head gates to palpation rails. Overcrowding did not have any adverse affect on production or user satisfaction with feed intake or cow comfort. Using supplemental cooling appeared to facilitate higher production.
Mejía-Terrazas, Gabriel Enrique; Ruiz-Suárez, Michell; Gaspar-Carrillo, Sandra Patricia; Valero-González, Fernando; Unzueta-Navarro, David; Encalada-Díaz, Iván
2014-01-01
Modern anesthesiology has integrated the use of ultrasonography as a tool that has displaced neurostimulation as a technique for locating peripheral nerves. The aim of this study was to determine which procedure is more effective for guiding interscalene block for total shoulder arthroplasty. We carried out a comparative, prospective non-randomized study comprised of the group guided by neurostimulation interscalene block and the group guided by ultrasound. All patients in both groups were scheduled for total shoulder arthroplasty. Latency, degree of sensory and motor block, success rate, postoperative pain intensity at 6, 12, and 24 h, patient satisfaction and complications were measured. We included 110 patients, 55 per group. Patients were placed in beach chair position and the deltopectoral approach was used. There were no differences in demographic characteristics. Results for neurostimulation vs. ultrasound group: latency 19.11 ± 2.27 vs. 17.24 ± 1.42 min, p= 0.23. Block sensitivity in both groups was grade 0 motor block grade 0 in 76.4% and grade 1 in 23.6% vs. grade 0 to 100%. There was 100% success rate for both groups. Postoperative pain at 6 h was 0.13 ± 0.54 vs. 0.11 ± 0.13 p= 0.90, at 12 h 1.67 ± 1.15 vs. 1.65 ± 0.59 p= 0.89 and at 24 h 3.15 ± 1.66 vs. 2.99 ± 1.15 p= 0.78. Satisfaction 54.5% very satisfied and 45.5% satisfied 96.36% vs 3.6% very satisfied and satisfied. Complications 18.18% vs. 3.6% p= 0.023. Ultrasound-guided interscalene nerve block is the technique of choice in elective total shoulder arthroplasty.
A Randomized Trial of Brief Interventions for Problem and Pathological Gamblers
ERIC Educational Resources Information Center
Petry, Nancy M.; Weinstock, Jeremiah; Ledgerwood, David M.; Morasco, Benjamin
2008-01-01
Limited research exists regarding methods for reducing problem gambling. Problem gamblers (N = 180) were randomly assigned to assessment only control, 10 min of brief advice, 1 session of motivational enhancement therapy (MET), or 1 session of MET plus 3 sessions of cognitive-behavioral therapy. Gambling was assessed at baseline, at 6 weeks, and…
A Model for Predicting Behavioural Sleep Problems in a Random Sample of Australian Pre-Schoolers
ERIC Educational Resources Information Center
Hall, Wendy A.; Zubrick, Stephen R.; Silburn, Sven R.; Parsons, Deborah E.; Kurinczuk, Jennifer J.
2007-01-01
Behavioural sleep problems (childhood insomnias) can cause distress for both parents and children. This paper reports a model describing predictors of high sleep problem scores in a representative population-based random sample survey of non-Aboriginal singleton children born in 1995 and 1996 (1085 girls and 1129 boys) in Western Australia.…
Random Walk Method for Potential Problems
NASA Technical Reports Server (NTRS)
Krishnamurthy, T.; Raju, I. S.
2002-01-01
A local Random Walk Method (RWM) for potential problems governed by Lapalace's and Paragon's equations is developed for two- and three-dimensional problems. The RWM is implemented and demonstrated in a multiprocessor parallel environment on a Beowulf cluster of computers. A speed gain of 16 is achieved as the number of processors is increased from 1 to 23.
Factors associated with work satisfaction of registered nurses.
Kovner, Christine; Brewer, Carol; Wu, Yow-Wu; Cheng, Ying; Suzuki, Miho
2006-01-01
To examine the factors that influence the work satisfaction of a national sample of registered nurses in metropolitan statistical areas (MSAs). A cross-sectional mailed survey design was used. The sample consisted of RNs randomly selected from 40 MSAs in 29 states; 1,907 RNs responded (48%). The sample of 1,538 RNs working in nursing was used for analysis. The questionnaire included measures of work attitudes and demographic characteristics. The data were analyzed using ordinary least-squares regression. More than 40% of the variance in satisfaction was explained by the various work attitudes: supervisor support, work-group cohesion, variety of work, autonomy, organizational constraint, promotional opportunities, work and family conflict, and distributive justice. RNs who were White, self-perceived as healthy, and working in nursing education were more satisfied. RNs that were more career oriented were more satisfied. Of the benefits options, only paid time off was related to satisfaction. Work-related factors were significantly related to RNs' work satisfaction.
Chua, Hannah Daile P; Ho, Samuel M Y; Cheung, Lim Kwong
2012-11-01
The objective of this study was to compare the psychological changes of patients with cleft lip and palate (CLP) undergoing maxillary Le Fort I advancement by distraction osteogenesis (DO) and conventional orthognathic surgery (CO). Prospective randomized controlled study. Participants completed a set of questionnaires to measure their psychological states preoperatively and postoperatively. When compared with CO, CLP patients treated with DO had lower social self-esteem and higher social avoidance and distress levels during the first 3 postoperative months. Their self-esteem, social avoidance, and distress levels improved after the distractors were removed. Both CO and DO patients had similar levels of self-esteem, social avoidance, and distress levels 2 years postoperatively. The CLP patients treated with DO were more satisfied with their lives after 2 years. DO may induce short-term distress to patients up to 3 months but CLP patients who received DO were more satisfied with their lives in the long term. Copyright © 2012 Elsevier Inc. All rights reserved.
ERIC Educational Resources Information Center
Comptroller General of the U.S., Washington, DC.
Amounts billed for teaching physician services and paid by Medicare carriers were reviewed by the General Accounting Office (GAO) to determine whether such payments had been made only where the physicians had satisfied the requirements of the Social Security Act. Attention was focused on the requirement that teaching physicians must provide a…
[The content-uniformity of dispensary-prepared rectal suppositories].
Lüdde, H; Nestler, D
1990-01-01
Rectal suppositories, which are dispensed according prescription in small numbers up to N = 30, do not satisfy the demands in respect of content uniformity, if we consider the last N/10 poured ones. This by sedimentation caused problem is to be solved in increasing the amount of substances by N/10, so that you will get a safety-amount of 15% totally.
ERIC Educational Resources Information Center
Nooripour, Roghieh; Bass, Christopher K.; Apsche, Jack
2013-01-01
Those who are addicted to substances face increased psychological emotional, social and economic problems which can potentially have negative impacts on marital satisfaction and sexual self-esteem and efficacy. Routine activities are often displaced by the need to satisfy the physiological urges. Within a marital union, this along with other…
Impossibility Theorem in Proportional Representation Problem
NASA Astrophysics Data System (ADS)
Karpov, Alexander
2010-09-01
The study examines general axiomatics of Balinski and Young and analyzes existed proportional representation methods using this approach. The second part of the paper provides new axiomatics based on rational choice models. New system of axioms is applied to study known proportional representation systems. It is shown that there is no proportional representation method satisfying a minimal set of the axioms (monotonicity and neutrality).
Impact of Alternative Timber Management Policies on Availability of Forest Land in the Northeast
Owen W. Herrick
1977-01-01
Gaging the ability of the forest resource to satisfy future timber requirements is central to solving many problems arising from competition for use of forest land. In this study, production potentials of forest acreage in the Northeastern United States under management alternatives that range from extensive to intensive are weighed against several estimates of timber...
American Indians and Federal Aid. Brookings Studies in Social Economics.
ERIC Educational Resources Information Center
Sorkin, Alan L.
"American Indians are the poorest of any nonwhite minority in the United States. Life on the reservation offers them few opportunities: if they move to the city, they face problems of adjustment that can prove insurmountable. What is being done--what more could be done--to help Indians satisfy their needs in a largely alien society? To develop the…