Application of Decomposition to Transportation Network Analysis

DOT National Transportation Integrated Search

1976-10-01

This document reports preliminary results of five potential applications of the decomposition techniques from mathematical programming to transportation network problems. The five application areas are (1) the traffic assignment problem with fixed de...

Equilibrium charge distribution on a finite straight one-dimensional wire

NASA Astrophysics Data System (ADS)

Batle, Josep; Ciftja, Orion; Abdalla, Soliman; Elhoseny, Mohamed; Alkhambashi, Majid; Farouk, Ahmed

2017-09-01

The electrostatic properties of uniformly charged regular bodies are prominently discussed on college-level electromagnetism courses. However, one of the most basic problems of electrostatics that deals with how a continuous charge distribution reaches equilibrium is rarely mentioned at this level. In this work we revisit the problem of equilibrium charge distribution on a straight one-dimensional (1D) wire with finite length. The majority of existing treatments in the literature deal with the 1D wire as a limiting case of a higher-dimensional structure that can be treated analytically for a Coulomb interaction potential between point charges. Surprisingly, different models (for instance, an ellipsoid or a cylinder model) may lead to different results, thus there is even some ambiguity on whether the problem is well-posed. In this work we adopt a different approach where we do not start with any higher-dimensional body that reduces to a 1D wire in the appropriate limit. Instead, our starting point is the obvious one, a finite straight 1D wire that contains charge. However, the new tweak in the model is the assumption that point charges interact with each other via a non-Coulomb power-law interaction potential. This potential is well-behaved, allows exact analytical results and approaches the standard Coulomb interaction potential as a limit. The results originating from this approach suggest that the equilibrium charge distribution for a finite straight 1D wire is a uniform charge density when the power-law interaction potential approaches the Coulomb interaction potential as a suitable limit. We contrast such a finding to results obtained using a different regularised logarithmic interaction potential which allows exact treatment in 1D. The present self-contained material may be of interest to instructors teaching electromagnetism as well as students who will discover that simple-looking problems may sometimes pose important scientific challenges.

Investigating the enhanced Best Performance Algorithm for Annual Crop Planning problem based on economic factors

PubMed Central

2017-01-01

The Annual Crop Planning (ACP) problem was a recently introduced problem in the literature. This study further expounds on this problem by presenting a new mathematical formulation, which is based on market economic factors. To determine solutions, a new local search metaheuristic algorithm is investigated which is called the enhanced Best Performance Algorithm (eBPA). eBPA’s results are compared against two well-known local search metaheuristic algorithms; these include Tabu Search and Simulated Annealing. The results show the potential of the eBPA for continuous optimization problems. PMID:28792495

Finite element analysis of time-independent superconductivity. Ph.D. Thesis Final Report

NASA Technical Reports Server (NTRS)

Schuler, James J.

1993-01-01

The development of electromagnetic (EM) finite elements based upon a generalized four-potential variational principle is presented. The use of the four-potential variational principle allows for downstream coupling of EM fields with the thermal, mechanical, and quantum effects exhibited by superconducting materials. The use of variational methods to model an EM system allows for a greater range of applications than just the superconducting problem. The four-potential variational principle can be used to solve a broader range of EM problems than any of the currently available formulations. It also reduces the number of independent variables from six to four while easily dealing with conductor/insulator interfaces. This methodology was applied to a range of EM field problems. Results from all these problems predict EM quantities exceptionally well and are consistent with the expected physical behavior.

Vestibular-evoked myogenic potential in response to bone-conducted sound in patients with otosclerosis

PubMed Central

Seo, Toru; Fujimori, Kiyoko; Mishiro, Yasuo; Sakagami, Masafumi

2012-01-01

Conclusion: Saccular dysfunction is a major cause of balance problems in patients with otosclerosis. Vestibular-evoked myogenic potential in response to bone-conducted sound (BC-VEMP) testing is useful for diagnosis of these patients. Objectives: The purpose of this study was to elucidate the origin of balance problems in patients with otosclerosis using BC-VEMP. Methods: Subjects comprised 25 patients with unoperated otosclerosis (9 men and 16 women). They were divided into two groups depending on type of balance problems. Results of cochleo-vestibular functions including pure-tone audiometry, caloric testing, and BC-VEMP testing were compared between the two groups. Results: Ten patients had complained of dizziness and/or vertigo (disequilibrium group), and the other 15 patients had not (Non-disequilibrium group). Nine patients showed abnormal results on BC-VEMP testing in the disequilibrium group, while one patient had abnormal results in the non-disequilibrium group (p < 0.001). PMID:22830649

Towards overcoming the Monte Carlo sign problem with tensor networks

NASA Astrophysics Data System (ADS)

Bañuls, Mari Carmen; Cichy, Krzysztof; Ignacio Cirac, J.; Jansen, Karl; Kühn, Stefan; Saito, Hana

2017-03-01

The study of lattice gauge theories with Monte Carlo simulations is hindered by the infamous sign problem that appears under certain circumstances, in particular at non-zero chemical potential. So far, there is no universal method to overcome this problem. However, recent years brought a new class of non-perturbative Hamiltonian techniques named tensor networks, where the sign problem is absent. In previous work, we have demonstrated that this approach, in particular matrix product states in 1+1 dimensions, can be used to perform precise calculations in a lattice gauge theory, the massless and massive Schwinger model. We have computed the mass spectrum of this theory, its thermal properties and real-time dynamics. In this work, we review these results and we extend our calculations to the case of two flavours and non-zero chemical potential. We are able to reliably reproduce known analytical results for this model, thus demonstrating that tensor networks can tackle the sign problem of a lattice gauge theory at finite density.

Wavelet-sparsity based regularization over time in the inverse problem of electrocardiography.

PubMed

Cluitmans, Matthijs J M; Karel, Joël M H; Bonizzi, Pietro; Volders, Paul G A; Westra, Ronald L; Peeters, Ralf L M

2013-01-01

Noninvasive, detailed assessment of electrical cardiac activity at the level of the heart surface has the potential to revolutionize diagnostics and therapy of cardiac pathologies. Due to the requirement of noninvasiveness, body-surface potentials are measured and have to be projected back to the heart surface, yielding an ill-posed inverse problem. Ill-posedness ensures that there are non-unique solutions to this problem, resulting in a problem of choice. In the current paper, it is proposed to restrict this choice by requiring that the time series of reconstructed heart-surface potentials is sparse in the wavelet domain. A local search technique is introduced that pursues a sparse solution, using an orthogonal wavelet transform. Epicardial potentials reconstructed from this method are compared to those from existing methods, and validated with actual intracardiac recordings. The new technique improves the reconstructions in terms of smoothness and recovers physiologically meaningful details. Additionally, reconstruction of activation timing seems to be improved when pursuing sparsity of the reconstructed signals in the wavelet domain.

Descriptive Analysis of Teachers' Responses to Problem Behavior Following Training

ERIC Educational Resources Information Center

Addison, Laura; Lerman, Dorothea C.

2009-01-01

The procedures described by Sloman et al. (2005) were extended to an analysis of teachers' responses to problem behavior after they had been taught to withhold potential sources of positive and negative reinforcement following instances of problem behavior. Results were consistent with those reported previously, suggesting that escape from child…

Equations of motion for the gravitational two-body problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitney, C.K.

1988-01-01

This paper reinvestigates the well-known gravitational two-body problem, in light of new information concerning the electrodynamic version of the problem. The well-known Lienard-Wiechert potentials, and the fields derived from them, are suspected to be time-shifted, anticipating the true potentials and fields by the time required for signal propagation from the source to the observer. This time shift is significant because it implies field directions different to first order in v/c. In the gravitational problem, the resulting observer accelerations become correlated with retarded source positions, rather than with present, unretarded source positions as was previously believed. This means there exist previouslymore » unrecognized first-order effects in gravitational systems.« less

Interactive and Indirect Effects of Anxiety and Negative Urgency on Alcohol-Related Problems

PubMed Central

Menary, Kyle R.; Corbin, William R.; Leeman, Robert F.; Fucito, Lisa M.; Toll, Benjamin A.; DeMartini, Kelly; O’Malley, Stephanie S.

2015-01-01

Background Although drinking for tension reduction has long been posited as a risk factor for alcohol-related problems, studies investigating anxiety in relation to risk for alcohol problems have returned inconsistent results, leading researchers to search for potential moderators. Negative urgency (the tendency to become behaviorally dysregulated when experiencing negative affect) is a potential moderator of theoretical interest because it may increase risk for alcohol problems among those high in negative affect. The present study tested a cross-sectional mediated moderation hypothesis whereby an interactive effect of anxiety and negative urgency on alcohol problems is mediated through coping-related drinking motives. Method The study utilized baseline data from a hazardously drinking sample of young adults (N = 193) evaluated for participation in a randomized controlled trial of naltrexone and motivational interviewing for drinking reduction. Results The direct effect of anxiety on physiological dependence symptoms was moderated by negative urgency such that the positive association between anxiety and physiological dependence symptoms became stronger as negative urgency increased. Indirect effects of anxiety and negative urgency on alcohol problems (operating through coping motives) were also observed. Conclusions Although results of the current cross-sectional study require replication using longitudinal data, the findings suggest that the simultaneous presence of anxiety and negative urgency may be an important indicator of risk for AUDs via both direct interactive effects and indirect additive effects operating through coping motives. These findings have potentially important implications for prevention/intervention efforts for individuals who become disinhibited in the context of negative emotional states. PMID:26031346

Comparison of potential method in analytic hierarchy process for multi-attribute of catering service companies

NASA Astrophysics Data System (ADS)

Mamat, Siti Salwana; Ahmad, Tahir; Awang, Siti Rahmah

2017-08-01

Analytic Hierarchy Process (AHP) is a method used in structuring, measuring and synthesizing criteria, in particular ranking of multiple criteria in decision making problems. On the other hand, Potential Method is a ranking procedure in which utilizes preference graph ς (V, A). Two nodes are adjacent if they are compared in a pairwise comparison whereby the assigned arc is oriented towards the more preferred node. In this paper Potential Method is used to solve problem on a catering service selection. The comparison of result by using Potential method is made with Extent Analysis. The Potential Method is found to produce the same rank as Extent Analysis in AHP.

The Effects of Group Monitoring on Fatigue-Related Einstellung during Mathematical Problem Solving

ERIC Educational Resources Information Center

Frings, Daniel

2011-01-01

Fatigue resulting from sleep deficit can lead to decreased performance in a variety of cognitive domains and can result in potentially serious accidents. The present study aimed to test whether fatigue leads to increased Einstellung (low levels of cognitive flexibility) in a series of mathematical problem-solving tasks. Many situations involving…

The Jost-Kohn inversion procedure

NASA Technical Reports Server (NTRS)

Prosser, R. T.

1972-01-01

Conditions are considered that must be imposed on a class of quantum mechanical problems to obtain reasonable results by the Jost-Kohn procedure. The discussion is restricted to problems in three space-dimensions without assuming any radial or other symmetry of the potential.

Aggression and violence in healthcare and its impact on nursing students: A narrative review of the literature.

PubMed

Hopkins, Martin; Fetherston, Catherine M; Morrison, Paul

2018-03-01

Aggression and violence is a significant social problem in many countries and an increasing problem in healthcare settings in which nurses are particularly vulnerable. The literature suggests that aggression and violence has a significant negative impact upon nurses and potentially upon nursing students and can result in these staff members experiencing stress as a direct result of these adverse events. The literature suggests that there is confusion over what constitutes aggression and violence in the workplace and therefore a true lack of understanding of the scale of the problem relating to nursing students. This review proposes that nursing students are indeed at significant risk of aggression and violence in the clinical setting which has the potential to significantly impact their role as a novice carer. Furthermore, aggression and violence can manifest negative stress responses in individuals, therefore, the potential for nursing students to cope with stressful situations shall be presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

NUMERICAL INTEGRAL OF RESISTANCE COEFFICIENTS IN DIFFUSION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Q. S., E-mail: zqs@ynao.ac.cn

2017-01-10

The resistance coefficients in the screened Coulomb potential of stellar plasma are evaluated to high accuracy. I have analyzed the possible singularities in the integral of scattering angle. There are possible singularities in the case of an attractive potential. This may result in a problem for the numerical integral. In order to avoid the problem, I have used a proper scheme, e.g., splitting into many subintervals where the width of each subinterval is determined by the variation of the integrand, to calculate the scattering angle. The collision integrals are calculated by using Romberg’s method, therefore the accuracy is high (i.e.,more » ∼10{sup −12}). The results of collision integrals and their derivatives for −7 ≤ ψ ≤ 5 are listed. By using Hermite polynomial interpolation from those data, the collision integrals can be obtained with an accuracy of 10{sup −10}. For very weakly coupled plasma ( ψ ≥ 4.5), analytical fittings for collision integrals are available with an accuracy of 10{sup −11}. I have compared the final results of resistance coefficients with other works and found that, for a repulsive potential, the results are basically the same as others’; for an attractive potential, the results in cases of intermediate and strong coupling show significant differences. The resulting resistance coefficients are tested in the solar model. Comparing with the widely used models of Cox et al. and Thoul et al., the resistance coefficients in the screened Coulomb potential lead to a slightly weaker effect in the solar model, which is contrary to the expectation of attempts to solve the solar abundance problem.« less

Use of a latency-based demand assessment to identify potential demands for functional analyses.

PubMed

Call, Nathan A; Miller, Sarah J; Mintz, Joslyn Cynkus; Mevers, Joanna Lomas; Scheithauer, Mindy C; Eshelman, Julie E; Beavers, Gracie A

2016-12-01

Unlike potential tangible positive reinforcers, which are typically identified for inclusion in functional analyses empirically using preference assessments, demands are most often selected arbitrarily or based on caregiver report. The present study evaluated the use of a demand assessment with 12 participants who exhibited escape-maintained problem behavior. Participants were exposed to 10 demands, with aversiveness measured by average latency to the first instance of problem behavior. In subsequent functional analyses, results of a demand condition that included the demand with the shortest latency to problem behavior resulted in identification of an escape function for 11 of the participants. In contrast, a demand condition that included the demand with the longest latency resulted in identification of an escape function for only 5 participants. The implication of these findings is that for the remaining 7 participants, selection of the demand for the functional analysis without using the results of the demand assessment could have produced a false-negative finding. © 2016 Society for the Experimental Analysis of Behavior.

Inversion of geophysical potential field data using the finite element method

NASA Astrophysics Data System (ADS)

Lamichhane, Bishnu P.; Gross, Lutz

2017-12-01

The inversion of geophysical potential field data can be formulated as an optimization problem with a constraint in the form of a partial differential equation (PDE). It is common practice, if possible, to provide an analytical solution for the forward problem and to reduce the problem to a finite dimensional optimization problem. In an alternative approach the optimization is applied to the problem and the resulting continuous problem which is defined by a set of coupled PDEs is subsequently solved using a standard PDE discretization method, such as the finite element method (FEM). In this paper, we show that under very mild conditions on the data misfit functional and the forward problem in the three-dimensional space, the continuous optimization problem and its FEM discretization are well-posed including the existence and uniqueness of respective solutions. We provide error estimates for the FEM solution. A main result of the paper is that the FEM spaces used for the forward problem and the Lagrange multiplier need to be identical but can be chosen independently from the FEM space used to represent the unknown physical property. We will demonstrate the convergence of the solution approximations in a numerical example. The second numerical example which investigates the selection of FEM spaces, shows that from the perspective of computational efficiency one should use 2 to 4 times finer mesh for the forward problem in comparison to the mesh of the physical property.

Applications of aerospace technology in biology and medicine

NASA Technical Reports Server (NTRS)

Wooten, F. T.

1972-01-01

The results are presented of the medically related activities of the NASA Application Team Program at the Research Triangle Institute. The accomplishments of the Research Triangle Institute Application Team during the reporting period are as follows: The team has identified 44 new problems for investigation, has accomplished 8 technology applications and 8 potential technology applications, has closed 88 old problems, and reactivated 3 old problems, and on August 31, 1972, has a total of 57 problems under active investigation.

Aerodynamic Shape Optimization Using A Real-Number-Encoded Genetic Algorithm

NASA Technical Reports Server (NTRS)

Holst, Terry L.; Pulliam, Thomas H.

2001-01-01

A new method for aerodynamic shape optimization using a genetic algorithm with real number encoding is presented. The algorithm is used to optimize three different problems, a simple hill climbing problem, a quasi-one-dimensional nozzle problem using an Euler equation solver and a three-dimensional transonic wing problem using a nonlinear potential solver. Results indicate that the genetic algorithm is easy to implement and extremely reliable, being relatively insensitive to design space noise.

UAV path planning using artificial potential field method updated by optimal control theory

NASA Astrophysics Data System (ADS)

Chen, Yong-bo; Luo, Guan-chen; Mei, Yue-song; Yu, Jian-qiao; Su, Xiao-long

2016-04-01

The unmanned aerial vehicle (UAV) path planning problem is an important assignment in the UAV mission planning. Based on the artificial potential field (APF) UAV path planning method, it is reconstructed into the constrained optimisation problem by introducing an additional control force. The constrained optimisation problem is translated into the unconstrained optimisation problem with the help of slack variables in this paper. The functional optimisation method is applied to reform this problem into an optimal control problem. The whole transformation process is deduced in detail, based on a discrete UAV dynamic model. Then, the path planning problem is solved with the help of the optimal control method. The path following process based on the six degrees of freedom simulation model of the quadrotor helicopters is introduced to verify the practicability of this method. Finally, the simulation results show that the improved method is more effective in planning path. In the planning space, the length of the calculated path is shorter and smoother than that using traditional APF method. In addition, the improved method can solve the dead point problem effectively.

[Potential antimicrobial drug interactions in clinical practice: consequences of polypharmacy and multidrug resistance].

PubMed

Martínez-Múgica, Cristina

2015-12-01

Polypharmacy is a growing problem nowadays, which can increase the risk of potential drug interactions, and result in a loss of effectiveness. This is particularly relevant to the anti-infective therapy, especially when infection is produced by resistant bacteria, because therapeutic options are limited and interactions can cause treatment failure. All antimicrobial prescriptions were retrospectively reviewed during a week in the Pharmacy Department, in order to detect potential drug-interactions and analysing their clinical significance. A total of 314 antimicrobial prescriptions from 151 patients were checked. There was at least one potential interaction detected in 40% of patients, being more frequent and severe in those infected with multidrug-resistant microorganisms. Drugs most commonly involved were quinolones, azoles, linezolid and vancomycin. Potential drug interactions with antimicrobial agents are a frequent problem that can result in a loss of effectiveness. This is why they should be detected and avoided when possible, in order to optimize antimicrobial therapy, especially in case of multidrug resistant infections.

Water-quality assessment of the Smith River drainage basin, California and Oregon

USGS Publications Warehouse

Iwatsubo, Rick T.; Washabaugh, Donna S.

1982-01-01

A water-quality assessment of the Smith River drainage basin was made to provide a summary of the water-quality conditions including known or potential water-quality problems. Results of the study showed that the water quality of the Smith River is excellent and generally meets the water-quality objectives for the beneficial uses identified by the California Regional Water Quality Control Board, North Coast Region. Known and potential problems related to water quality include: Sedimentation resulting from both natural erosional processes and land-use activities such as timber harvest, road construction, and mining that accelerate the erosional processes; bacterial contamination of surface and ground waters from inundated septic tanks and drainfields, and grazing activities; industrial spills which have resulted in fish kills and oil residues; high concetrations of iron in ground water; log and debris jams creating fish migration barriers; and pesticide and trace-element contamination from timber-harvest and mining activities, respectively. Future studies are needed to establish: (1) a sustained long-term monitoring program to provide a broad coverage of water-quality conditions in order to define long-term water-quality trends; and (2) interpretive studies to determine the source of known and potential water-quality problems. (USGS)

Source localization in electromyography using the inverse potential problem

NASA Astrophysics Data System (ADS)

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

2011-02-01

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

Write Is Right: Using Graphic Organizers to Improve Student Mathematical Problem Solving

ERIC Educational Resources Information Center

Zollman, Alan

2012-01-01

Teachers have used graphic organizers successfully in teaching the writing process. This paper describes graphic organizers and their potential mathematics benefits for both students and teachers, elucidates a specific graphic organizer adaptation for mathematical problem solving, and discusses results using the "four-corners-and-a-diamond"…

Development of sinkholes resulting from man's activities in the Eastern United States

USGS Publications Warehouse

Newton, John G.

1987-01-01

Alternatives that allow avoiding or minimizing sinkhole hazards are most numerous when a problem or potential problem is recognized during site evaluation. The number of alternatives declines after the beginning of site development. Where sinkhole development is predictable, zoning of land use can minimize hazards.

Semiclassical theory of the self-consistent vibration-rotation fields and its application to the bending-rotation interaction in the H{sub 2}O molecule

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skalozub, A.S.; Tsaune, A.Ya.

1994-12-01

A new approach for analyzing the highly excited vibration-rotation (VR) states of nonrigid molecules is suggested. It is based on the separation of the vibrational and rotational terms in the molecular VR Hamiltonian by introducing periodic auxiliary fields. These fields transfer different interactions within a molecule and are treated in terms of the mean-field approximation. As a result, the solution of the stationary Schroedinger equation with the VR Hamiltonian amounts to a quantization of the Berry phase in a problem of the molecular angular-momentum motion in a certain periodic VR field (rotational problem). The quantization procedure takes into account themore » motion of the collective vibrational variables in the appropriate VR potentials (vibrational problem). The quantization rules, the mean-field configurations of auxiliary interactions, and the solutions to the Schrodinger equations for the vibrational and rotational problems are self-consistently connected with one another. The potentialities of the theory are demonstrated by the bending-rotation interaction modeled by the Bunker-Landsberg potential function in the H{sub 2} molecule. The calculations are compared with both the results of the exact computations and those of other approximate methods. 32 refs., 4 tabs.« less

TRANSIENT DUPUIT INTERFACE FLOW WITH PARTIALLY PENETRATING FEATURES

EPA Science Inventory

A comprehensive potential is presented for Dupuit interface flow in coastal aquifers where both the fresh water and salt water are moving. The resulting potential flow problem may be solved, for incompressible confined aquifers, using analytic functions. The vertical velocity of ...

The roles of the convex hull and the number of potential intersections in performance on visually presented traveling salesperson problems.

PubMed

Vickers, Douglas; Lee, Michael D; Dry, Matthew; Hughes, Peter

2003-10-01

The planar Euclidean version of the traveling salesperson problem requires finding the shortest tour through a two-dimensional array of points. MacGregor and Ormerod (1996) have suggested that people solve such problems by using a global-to-local perceptual organizing process based on the convex hull of the array. We review evidence for and against this idea, before considering an alternative, local-to-global perceptual process, based on the rapid automatic identification of nearest neighbors. We compare these approaches in an experiment in which the effects of number of convex hull points and number of potential intersections on solution performance are measured. Performance worsened with more points on the convex hull and with fewer potential intersections. A measure of response uncertainty was unaffected by the number of convex hull points but increased with fewer potential intersections. We discuss a possible interpretation of these results in terms of a hierarchical solution process based on linking nearest neighbor clusters.

A usability evaluation of four commercial dental computer-based patient record systems

PubMed Central

Thyvalikakath, Thankam P.; Monaco, Valerie; Thambuganipalle, Hima Bindu; Schleyer, Titus

2008-01-01

Background The usability of dental computer-based patient record (CPR) systems has not been studied, despite early evidence that poor usability is a problem for dental CPR system users at multiple levels. Methods The authors conducted formal usability tests of four dental CPR systems by using a purposive sample of four groups of five novice users. The authors measured task outcomes (correctly completed, incorrectly completed and incomplete) in each CPR system while the participants performed nine clinical documentation tasks, as well as the number of usability problems identified in each CPR system and their potential relationship to task outcomes. The authors reviewed the software application design aspects responsible for these usability problems. Results The range for correctly completed tasks was 16 to 64 percent, for incorrectly completed tasks 18 to 38 percent and for incomplete tasks 9 to 47 percent. The authors identified 286 usability problems. The main types were three unsuccessful attempts, negative affect and task incorrectly completed. They also identified six problematic interface and interaction designs that led to usability problems. Conclusion The four dental CPR systems studied have significant usability problems for novice users, resulting in a steep learning curve and potentially reduced system adoption. Clinical Implications The significant number of data entry errors raises concerns about the quality of documentation in clinical practice. PMID:19047669

Black hole algorithm for determining model parameter in self-potential data

NASA Astrophysics Data System (ADS)

Sungkono; Warnana, Dwa Desa

2018-01-01

Analysis of self-potential (SP) data is increasingly popular in geophysical method due to its relevance in many cases. However, the inversion of SP data is often highly nonlinear. Consequently, local search algorithms commonly based on gradient approaches have often failed to find the global optimum solution in nonlinear problems. Black hole algorithm (BHA) was proposed as a solution to such problems. As the name suggests, the algorithm was constructed based on the black hole phenomena. This paper investigates the application of BHA to solve inversions of field and synthetic self-potential (SP) data. The inversion results show that BHA accurately determines model parameters and model uncertainty. This indicates that BHA is highly potential as an innovative approach for SP data inversion.

A genuinely discontinuous approach for multiphase EHD problems

NASA Astrophysics Data System (ADS)

Natarajan, Mahesh; Desjardins, Olivier

2017-11-01

Electrohydrodynamics (EHD) involves solving the Poisson equation for the electric field potential. For multiphase flows, although the electric field potential is a continuous quantity, due to the discontinuity in the electric permittivity between the phases, additional jump conditions at the interface, for the normal and tangential components of the electric field need to be satisfied. All approaches till date either ignore the jump conditions, or involve simplifying assumptions, and hence yield unconvincing results even for simple test problems. In the present work, we develop a genuinely discontinuous approach for the Poisson equation for multiphase flows using a Finite Volume Unsplit Volume of Fluid method. The governing equation and the jump conditions without assumptions are used to develop the method, and its efficiency is demonstrated by comparison of the numerical results with canonical test problems having exact solutions. Postdoctoral Associate, Department of Mechanical and Aerospace Engineering.

Efficient Planning of Wind-Optimal Routes in North Atlantic Oceanic Airspace

NASA Technical Reports Server (NTRS)

Rodionova, Olga; Sridhar, Banavar

2017-01-01

The North Atlantic oceanic airspace (NAT) is crossed daily by more than a thousand flights, which are greatly affected by strong jet stream air currents. Several studies devoted to generating wind-optimal (WO) aircraft trajectories in the NAT demonstrated great efficiency of such an approach for individual flights. However, because of the large separation norms imposed in the NAT, previously proposed WO trajectories induce a large number of potential conflicts. Much work has been done on strategic conflict detection and resolution (CDR) in the NAT. The work presented here extends previous methods and attempts to take advantage of the NAT traffic structure to simplify the problem and improve the results of CDR. Four approaches are studied in this work: 1) subdividing the existing CDR problem into sub-problems of smaller sizes, which are easier to handle; 2) more efficient data reorganization within the considered time period; 3) problem localization, i.e. concentrating the resolution effort in the most conflicted regions; 4) applying CDR to the pre-tactical decision horizon (a couple of hours in advance). Obtained results show that these methods efficiently resolve potential conflicts at the strategic and pre-tactical levels by keeping the resulting trajectories close to the initial WO ones.

An investigation into drug-related problems identifiable by commercial medication review software.

PubMed

Curtain, Colin; Bindoff, Ivan; Westbury, Juanita; Peterson, Gregory

2013-01-01

Accredited pharmacists conduct home medicines reviews (HMRs) to detect and resolve potential drug-related problems (DRPs). A commercial expert system, Medscope Review Mentor (MRM), has been developed to assist pharmacists in the detection and resolution of potential DRPs. This study compares types of DRPs identified with the commercial system which uses multiple classification ripple down rules (MCRDR) with the findings of pharmacists. HMR data from 570 reviews collected from accredited pharmacists was entered into MRM and the DRPs were identified. A list of themes describing the main concept of each DRP identified by MRM was developed to allow comparison with pharmacists. Theme types, frequencies, similarity and dissimilarity were explored. The expert system was capable of detecting a wide range of potential DRPs: 2854 themes; compared to pharmacists: 1680 themes. The system identified the same problems as pharmacists in many patient cases. Ninety of 119 types of themes identifiable by pharmacists were also identifiable by software. MRM could identify the same problems in the same patients as pharmacists for 389 problems, resulting in a low overlap of similarity with an averaged Jaccard Index of 0.09. MRM found significantly more potential DRPs than pharmacists. MRM identified a wide scope of DRPs approaching the range of DRPs that were identified by pharmacists. Differences may be associated with system consistency and perhaps human oversight or human selective prioritisation. DRPs identified by the system were still considered relevant even though the system identified a larger number of problems.

[Nursing diagnoses and most common collaboration problems in high-risk pregnancy].

PubMed

Gouveia, Helga Geremias; Lopes, Maria Helena Baena de Moraes

2004-01-01

This study identified the demographic profile, obstetric and clinical diagnoses, nursing diagnosis and most common collaboration problem among pregnant women subject to high-risk at a hospital in São Paulo, Brazil. Data were collected by means of a form based on Gordon's Functional Health Patterns. Nursing diagnoses were determined on the basis of the NANDA (North American Nursing Diagnosis Association) taxonomy. The nursing diagnoses found in 50% or more of the pregnant women were: risk for infection (90.1%), altered health maintenance (84.5%), altered comfort (80.3%), risk of ineffective breastfeeding (59.2%), altered sexuality patterns (52.1%), fear (52.1%) and pain (50.7%). The collaboration problem found in 50% or more of the cases was: potential complication: preterm labor (62.0%), potential complication: maternal tachycardia (54,9%) and potential complication: hypotension (54,9%). Thus, these results will allow us to guide the nursing care rendered to these pregnant women.

Two-machine flow shop scheduling integrated with preventive maintenance planning

NASA Astrophysics Data System (ADS)

Wang, Shijin; Liu, Ming

2016-02-01

This paper investigates an integrated optimisation problem of production scheduling and preventive maintenance (PM) in a two-machine flow shop with time to failure of each machine subject to a Weibull probability distribution. The objective is to find the optimal job sequence and the optimal PM decisions before each job such that the expected makespan is minimised. To investigate the value of integrated scheduling solution, computational experiments on small-scale problems with different configurations are conducted with total enumeration method, and the results are compared with those of scheduling without maintenance but with machine degradation, and individual job scheduling combined with independent PM planning. Then, for large-scale problems, four genetic algorithm (GA) based heuristics are proposed. The numerical results with several large problem sizes and different configurations indicate the potential benefits of integrated scheduling solution and the results also show that proposed GA-based heuristics are efficient for the integrated problem.

Estimates of green tensors for certain boundary value problems

NASA Technical Reports Server (NTRS)

Solonnikov, V.

1988-01-01

Consider the first boundary value problem for a stationary Navier-Stokes system in a bounded three-dimensional region Omega with the boundary S: delta v = grad p+f, div v=0, v/s=0. Odqvist (1930) developed the potential theory and formulated the Green tensor for the above problem. The basic singular solution used by Odqvist to express the Green tensor is given. A theorem generalizing his results is presented along with four associated theorems. A specific problem associated with the study of the differential properties of the solution of stationary problems of magnetohydrodynamics is examined.

Balancing antagonistic time and resource utilization constraints in over-subscribed scheduling problems

NASA Technical Reports Server (NTRS)

Smith, Stephen F.; Pathak, Dhiraj K.

1991-01-01

In this paper, we report work aimed at applying concepts of constraint-based problem structuring and multi-perspective scheduling to an over-subscribed scheduling problem. Previous research has demonstrated the utility of these concepts as a means for effectively balancing conflicting objectives in constraint-relaxable scheduling problems, and our goal here is to provide evidence of their similar potential in the context of HST observation scheduling. To this end, we define and experimentally assess the performance of two time-bounded heuristic scheduling strategies in balancing the tradeoff between resource setup time minimization and satisfaction of absolute time constraints. The first strategy considered is motivated by dispatch-based manufacturing scheduling research, and employs a problem decomposition that concentrates local search on minimizing resource idle time due to setup activities. The second is motivated by research in opportunistic scheduling and advocates a problem decomposition that focuses attention on the goal activities that have the tightest temporal constraints. Analysis of experimental results gives evidence of differential superiority on the part of each strategy in different problem solving circumstances. A composite strategy based on recognition of characteristics of the current problem solving state is then defined and tested to illustrate the potential benefits of constraint-based problem structuring and multi-perspective scheduling in over-subscribe scheduling problems.

Determination of Nerve Fiber Diameter Distribution From Compound Action Potential: A Continuous Approach.

PubMed

Un, M Kerem; Kaghazchi, Hamed

2018-01-01

When a signal is initiated in the nerve, it is transmitted along each nerve fiber via an action potential (called single fiber action potential (SFAP)) which travels with a velocity that is related with the diameter of the fiber. The additive superposition of SFAPs constitutes the compound action potential (CAP) of the nerve. The fiber diameter distribution (FDD) in the nerve can be computed from the CAP data by solving an inverse problem. This is usually achieved by dividing the fibers into a finite number of diameter groups and solve a corresponding linear system to optimize FDD. However, number of fibers in a nerve can be measured sometimes in thousands and it is possible to assume a continuous distribution for the fiber diameters which leads to a gradient optimization problem. In this paper, we have evaluated this continuous approach to the solution of the inverse problem. We have utilized an analytical function for SFAP and an assumed a polynomial form for FDD. The inverse problem involves the optimization of polynomial coefficients to obtain the best estimate for the FDD. We have observed that an eighth order polynomial for FDD can capture both unimodal and bimodal fiber distributions present in vivo, even in case of noisy CAP data. The assumed FDD distribution regularizes the ill-conditioned inverse problem and produces good results.

The Impact of Micromessaging on Performance and Productivity in Information Technology Environments

ERIC Educational Resources Information Center

Brown, Richard T., Jr.

2012-01-01

The problem examined in the study was how microinequities affect organizational productivity and performance as a result of employee exclusion, which may lead to morale issues and problems with retention. The purpose of the study was to investigate the potential effect of micromessaging on performance and productivity in information technology…

FACTS AND IRONIES OF THE WATER SITUATION IN THE SOUTHWEST.

ERIC Educational Resources Information Center

KNOWLTON, CLARK S.

THE SOUTHWEST IS SEEN AS A REGION LONG DOMINATED BY RANCHING, MINING, AND IRRIGATED AGRICULTURE. RAPID URBANIZATION AND INDUSTRIALIZATION IS RESULTING IN WATER PROBLEMS SIGNIFICANT TO A SOCIOCULTURAL AND A PHYSICAL ENVIRONMENT. THE FIRST GROUP OF PROBLEMS IS CHARACTERIZED BY INDIFFERENCES TO DROUGHT AND WATER DEPLETION POTENTIAL SINCE WATER USERS…

INVESTIGATIONS OF REPORTED PLANT AND ANIMAL HEALTH EFFECTS IN THE THREE MILE ISLAND AREA

EPA Science Inventory

The results of investigations into reported problems with plants and animals which may be related to the operation of and accident at the Three Mile Island Nuclear Power Station are presented. The kinds of problems reported are listed, and potential areas of concern (such as the ...

A BAYES LIKELIHOOD INFORMATION THEORETIC APPROACH FOR THE EXOGENOUS AGGREGATION OF REGIONAL GROUND WATER QUALITY DATA

EPA Science Inventory

This work addresses a potentially serious problem in analysis or synthesis of spatially explicit data on ground water quality from wells, known to geographers as the modifiable areal unit problem (MAUP). It results from the fact that in regional aggregation of spatial data, inves...

Results of the recent precipitation static flight test program on the Navy P-3B antisubmarine aircraft

NASA Technical Reports Server (NTRS)

Whitaker, Mike

1991-01-01

Severe precipitation static problems affecting the communication equipment onboard the P-3B aircraft were recently studied. The study was conducted after precipitation static created potential safety-of-flight problems on Naval Reserve aircraft. A specially designed flight test program was conducted in order to measure, record, analyze, and characterize potential precipitation static problem areas. The test program successfully characterized the precipitation static interference problems while the P-3B was flown in moderate to extreme precipitation conditions. Data up to 400 MHz were collected on the effects of engine charging, precipitation static, and extreme cross fields. These data were collected using a computer controlled acquisition system consisting of a signal generator, RF spectrum and audio analyzers, data recorders, and instrumented static dischargers. The test program is outlined and the computer controlled data acquisition system is described in detail which was used during flight and ground testing. The correlation of test results is also discussed which were recorded during the flight test program and those measured during ground testing.

Multidisciplinary and participatory workshops with stakeholders in a community of extreme poverty in the Peruvian Amazon: Development of priority concerns and potential health, nutrition and education interventions

PubMed Central

Casapia, Martin; Joseph, Serene A; Gyorkos, Theresa W

2007-01-01

Background Communities of extreme poverty suffer disproportionately from a wide range of adverse outcomes, but are often neglected or underserved by organized services and research attention. In order to target the first Millennium Development Goal of eradicating extreme poverty, thereby reducing health inequalities, participatory research in these communities is needed. Therefore, the purpose of this study was to determine the priority problems and respective potential cost-effective interventions in Belen, a community of extreme poverty in the Peruvian Amazon, using a multidisciplinary and participatory focus. Methods Two multidisciplinary and participatory workshops were conducted with important stakeholders from government, non-government and community organizations, national institutes and academic institutions. In Workshop 1, participants prioritized the main health and health-related problems in the community of Belen. Problem trees were developed to show perceived causes and effects for the top six problems. In Workshop 2, following presentations describing data from recently completed field research in school and household populations of Belen, participants listed potential interventions for the priority problems, including associated barriers, enabling factors, costs and benefits. Results The top ten priority problems in Belen were identified as: 1) infant malnutrition; 2) adolescent pregnancy; 3) diarrhoea; 4) anaemia; 5) parasites; 6) lack of basic sanitation; 7) low level of education; 8) sexually transmitted diseases; 9) domestic violence; and 10) delayed school entry. Causes and effects for the top six problems, proposed interventions, and factors relating to the implementation of interventions were multidisciplinary in nature and included health, nutrition, education, social and environmental issues. Conclusion The two workshops provided valuable insight into the main health and health-related problems facing the community of Belen. The participatory focus of the workshops ensured the active involvement of important stakeholders from Belen. Based on the results of the workshops, effective and essential interventions are now being planned which will contribute to reducing health inequalities in the community. PMID:17623093

Bullying and Internalizing Problems: Gender Differences and the Buffering Role of Parental Communication

PubMed Central

Ledwell, Maggie; King, Valarie

2013-01-01

Bullying is a widespread problem facing American adolescents. A better understanding of factors that may moderate the impact of bullying is important given its negative consequences for well-being. This study examines the association between bullying experiences and internalizing problems among a nationally representative sample of young adolescents. Additionally, we consider the ease of parental communication as a potential moderating factor in these associations. Using a structural equation modeling technique, results suggest that bullying is characteristically different for adolescent boys and girls and that its association with internalizing problems is stronger for adolescent females. Results also indicate that parental communication moderates the association between bullying and internalizing problems; higher levels of parental communication buffer adolescents against the negative influence of bullying. PMID:25892837

Consequences Identification in Forecasting and Ethical Decision-making

PubMed Central

Stenmark, Cheryl K.; Antes, Alison L.; Thiel, Chase E.; Caughron, Jared J.; Wang, Xiaoqian; Mumford, Michael D.

2015-01-01

Forecasting involves predicting outcomes based on observations of the situation at hand. We examined the impact of the number and types of consequences considered on the quality of ethical decision-making. Undergraduates role-played several ethical problems in which they forecast potential outcomes and made decisions. Performance pressure (difficult demands placed on the situation) and interpersonal conflict (clashes among people in the problem situation) were manipulated within each problem scenario. The results indicated that the identification of potential consequences was positively associated with both higher quality forecasts and more ethical decisions. Neither performance pressure nor interpersonal conflict affected the quality of forecasts or decisions. Theoretical and practical implications of these findings and the use of this research approach are discussed. PMID:21460584

Extracurricular activity participation moderates impact of family and school factors on adolescents' disruptive behavioural problems.

PubMed

Driessens, Corine M E F

2015-11-11

The prevalence of problem behaviours among British adolescents has increased in the past decades. Following Erikson's psychosocial developmental theory and Bronfenbrenner's developmental ecological model, it was hypothesized that youth problem behaviour is shaped in part by social environment. The aim of this project was to explore potential protective factors within the social environment of British youth's for the presentation of disruptive behavioural problems. This study used secondary data from the Longitudinal Study of Young People in England, a cohort study of secondary school students. These data were analysed with generalized estimation equations to take the correlation between the longitudinal observations into account. Three models were built. The first model determined the effect of family, school, and extracurricular setting on presentation of disruptive behavioural problems. The second model expanded the first model by assuming extracurricular activities as protective factors that moderated the interaction between family and school factors with disruptive behavioural problems. The third model described the effect of prior disruptive behaviour on current disruptive behaviour. Associations were found between school factors, family factors, involvement in extracurricular activities and presence of disruptive behavioural problems. Results from the second generalized estimating equation (GEE) logistic regression models indicated that extracurricular activities buffered the impact of school and family factors on the presence of disruptive behavioural problems. For instance, participation in sports activities decreased the effect of bullying on psychological distress. Results from the third model indicated that prior acts of disruptive behaviour reinforced current disruptive behaviour. This study supports Erikson's psychosocial developmental theory and Bronfenbrenner's developmental ecological model; social environment did influence the presence of disruptive behavioural problems for British adolescents. The potential of extracurricular activities to intervention strategies addressing disruptive behavioural problems of adolescents is discussed.

A finite-element analysis for steady and oscillatory supersonic flows around complex configurations

NASA Technical Reports Server (NTRS)

Morino, L.; Chen, L. T.

1974-01-01

The problem of small perturbation potential supersonic flow around complex configurations is considered. This problem requires the solution of an integral equation relating the values of the potential on the surface of the body to the values of the normal derivative, which is known from the small perturbation boundary conditions. The surface of the body is divided into small (hyperboloidal quadrilateral) surface elements, sigma sub i, which are described in terms of the Cartesian components of the four corner points. The values of the potential (and its normal derivative) within each element is assumed to be constant and equal to its value at the centroid of the element, and this yields a set of linear algebraic equations. The coefficients of the equation are given by source and doublet integrals over the surface elements, sigma sub i. The results obtained using the above formulation are compared with existing analytical and experimental results.

Robust CO2 Injection: Application of Bayesian-Information-Gap Decision Theory

NASA Astrophysics Data System (ADS)

Grasinger, M.; O'Malley, D.; Vesselinov, V. V.; Karra, S.

2015-12-01

Carbon capture and sequestration has the potential to reduce greenhouse gasemissions. However, care must be taken when choosing a site for CO2 seques-tration to ensure that the CO2 remains sequestered for many years, and thatthe environment is not harmed in any way. Making a rational decision be-tween potential sites for sequestration is not without its challenges because, asin the case of many environmental and subsurface problems, there is a lot ofuncertainty that exists. A method for making decisions under various typesand severities of uncertainty, Bayesian-Information-Gap Decision Theory (BIGDT), is presented. BIG DT was coupled with a numerical model for CO2 wellinjection and the resulting framework was then applied to a problem of selectingbetween two potential sites for CO2 sequestration. The results of the analysisare presented, followed by a discussion of the decision process.

Some problems in applications of the linear variational method

NASA Astrophysics Data System (ADS)

Pupyshev, Vladimir I.; Montgomery, H. E.

2015-09-01

The linear variational method is a standard computational method in quantum mechanics and quantum chemistry. As taught in most classes, the general guidance is to include as many basis functions as practical in the variational wave function. However, if it is desired to study the patterns of energy change accompanying the change of system parameters such as the shape and strength of the potential energy, the problem becomes more complicated. We use one-dimensional systems with a particle in a rectangular or in a harmonic potential confined in an infinite rectangular box to illustrate situations where a variational calculation can give incorrect results. These situations result when the energy of the lowest eigenvalue is strongly dependent on the parameters that describe the shape and strength of the potential. The numerical examples described in this work are provided as cautionary notes for practitioners of numerical variational calculations.

Analysis of the Hessian for Aerodynamic Optimization: Inviscid Flow

NASA Technical Reports Server (NTRS)

Arian, Eyal; Ta'asan, Shlomo

1996-01-01

In this paper we analyze inviscid aerodynamic shape optimization problems governed by the full potential and the Euler equations in two and three dimensions. The analysis indicates that minimization of pressure dependent cost functions results in Hessians whose eigenvalue distributions are identical for the full potential and the Euler equations. However the optimization problems in two and three dimensions are inherently different. While the two dimensional optimization problems are well-posed the three dimensional ones are ill-posed. Oscillations in the shape up to the smallest scale allowed by the design space can develop in the direction perpendicular to the flow, implying that a regularization is required. A natural choice of such a regularization is derived. The analysis also gives an estimate of the Hessian's condition number which implies that the problems at hand are ill-conditioned. Infinite dimensional approximations for the Hessians are constructed and preconditioners for gradient based methods are derived from these approximate Hessians.

On making cuts for magnetic scalar potentials in multiply connected regions

NASA Astrophysics Data System (ADS)

Kotiuga, P. R.

1987-04-01

The problem of making cuts is of importance to scalar potential formulations of three-dimensional eddy current problems. Its heuristic solution has been known for a century [J. C. Maxwell, A Treatise on Electricity and Magnetism, 3rd ed. (Clarendon, Oxford, 1981), Chap. 1, Article 20] and in the last decade, with the use of finite element methods, a restricted combinatorial variant has been proposed and solved [M. L. Brown, Int. J. Numer. Methods Eng. 20, 665 (1984)]. This problem, in its full generality, has never received a rigorous mathematical formulation. This paper presents such a formulation and outlines a rigorous proof of existence. The technique used in the proof expose the incredible intricacy of the general problem and the restrictive assumptions of Brown [Int. J. Numer. Methods Eng. 20, 665 (1984)]. Finally, the results make rigorous Kotiuga's (Ph. D. Thesis, McGill University, Montreal, 1984) heuristic interpretation of cuts and duality theorems via intersection matrices.

Mothers' alcohol and other drug problems and their punitiveness toward their children.

PubMed

Miller, B A; Smyth, N J; Mudar, P J

1999-09-01

The relationship between mothers' alcohol or other drug (AOD) problems and their punitiveness toward their children is examined in this study. Women (N = 170) were recruited from five different sources, including clinical interventions and the community. Women's punitiveness toward their children was assessed by three different maternal self-report measures: Conflict Tactics Scale, Parental Punitiveness Scale and Child Abuse Potential Inventory. Women's histories of AOD problems, violent victimization and hostility were assessed using standardized assessment tools. Women were categorized by their AOD problems as follows: current problem (22.4%), past only problem (44.7%) or no problems (32.9%). Results indicate that mothers with current or past AOD problems are more punitive toward their children, controlling for potentially confounding demographic factors. Mothers' histories of partner violence and parental violence also predicted higher levels of mother-to-child punitiveness. However, histories of childhood sexual abuse predicted lower levels of mothers' punitiveness. Hostility served as a predictor of mothers' punitiveness and moderated some of the relationships between their AOD problems and their punitiveness. Findings suggest that women with AOD problems are more likely to be punitive toward their children, but other factors may also contribute to this risk. Treatment and prevention interventions need to be developed to decrease the risk of violent victimization among children whose mothers have alcohol and other drug problems.

Equilibium and Stability of Spherical Vlasov Systems

NASA Astrophysics Data System (ADS)

Barnes, D. C.; Chacon, L.; Finn, J. M.

2002-04-01

Collisionless systems with inverse square interaction potentials and possible background confining potentials are considered for the case of spherical symmetry and in the Vlasov limit. The equilibrium is the most general, with single-particle distribution function dependence on both total energy E and total angular momentum L. A new formulation of the full integral-equation stability problem is developed. For a general spherical harmonic perturbation potential, the 3D stability problem is reduced to a 2D problem in an arbitrary central plane of motion, then to a small number of coupled 1D problems involving only the radius. Normal modes depend only on the total mode number l, as is shown directly by this new formulation, with all m degenerate. This method has been used for the Coulomb (repulsive) case.[1] An equilibrium family with uniform central (electron) density is found, and the low-frequency response computed to show that these solutions may provide stable confinement of a massive second (ion) species. These methods may be applied to a particle bunch in the beam frame, and some stability results appropriate to this case are presented. Application to the gravitational (attractive) case is also described, and some initial analytic results are presented. [1] D. C. Barnes, L. Chacón, J. M. Finn, “Equilibrium and Low-frequency Stability of a Uniform Density, Collisionless, Spherical Vlasov System,” submitted to Phys. of Plasmas (2002).

Analysis and Design of Complex Network Environments

DTIC Science & Technology

2014-02-01

entanglements among un- measured variables. This “potential entanglement ” type of network complexity is previously unaddressed in the literature, yet it...Appreciating the power of structural representations that allow for potential entanglement among unmeasured variables to simplify network inference problems...rely on the idea of subsystems and allows for potential entanglement among unmeasured states. As a result, inferring a system’s signal structure

The Prevalence and Impact of Voice Problems among Physical Education Teachers

ERIC Educational Resources Information Center

Ryan, Stu; Rotunda, Robert; Song, Charlie; Maina, Michael

2012-01-01

The focus of this research effort was to examine the prevalence and impact of voice problems among a sample of physical education teachers. The survey was administered to K-12 physical education teachers (n = 199) addressing three aspects of voice issues: consequences, strategies for prevention, and potential risk factors. The results indicated a…

A Case Study of University-Community Collaboration to Reduce the Negative Effects of Binge Drinking

ERIC Educational Resources Information Center

Williams, Michael B.

2013-01-01

Binge drinking is a prevalent, persistent problem within U.S. university cities. Consequences of students' binge drinking can result in injury, assault, disruption in neighborhoods, and even death. Proponents of one potential solution to the problem, the environmental approach, propose changing the context of drinking by altering factors such…

Exact Electromagnetic Fields Produced by a Finite Wire with Constant Current

ERIC Educational Resources Information Center

Jimenez, J. L.; Campos, I.; Aquino, N.

2008-01-01

We solve exactly the problem of calculating the electromagnetic fields produced by a finite wire with a constant current, by using two methods: retarded potentials and Jefimenko's formalism. One result in this particular case is that the usual Biot-Savart law of magnetostatics gives the correct magnetic field of the problem. We also show…

Assessment of groundwater recharge potential zone using GIS approach in Purworejo regency, Central Java province, Indonesia

NASA Astrophysics Data System (ADS)

Aryanto, Daniel Eko; Hardiman, Gagoek

2018-02-01

Floods and droughts in Purworejo regency are an indication of problems in groundwater management. The current development progress has led to land conversion which has an impact on the problem of water infiltration in Purworejo regency. This study aims to determine the distribution of groundwater recharge potential zones by using geographic information system as the basis for ground water management. The groundwater recharge potential zone is obtained by overlaying all the thematic maps that affect the groundwater infiltration. Each thematic map is weighted according to its effect on groundwater infiltration such as land-use - 25%, rainfall - 20%, litology - 20%, soil - 15%, slope - 10%, lineament - 5%, and river density - 5% to find groundwater recharge potential zones. The groundwater recharge potential zones thus obtained were divided into five categories, viz., very high, high, medium, low and very low zones. The results of this study may be useful for better groundwater planning and management.

An Infrared Solution to a National Priority NASA Ice Detection and Measurement Problem

NASA Technical Reports Server (NTRS)

Meitzler, Thomas; Bryk, Darryl; Sohn, Euijung; Bienkowski, Mary; Lane, Kimberly; Smith, Gregory; Charbeneau, Michelle; Moss, Thomas; Speece, Robert; Stevenson, Charles;

Rejection Sensitivity and Depression: Indirect Effects Through Problem Solving.

PubMed

Kraines, Morganne A; Wells, Tony T

2017-01-01

Rejection sensitivity (RS) and deficits in social problem solving are risk factors for depression. Despite their relationship to depression and the potential connection between them, no studies have examined RS and social problem solving together in the context of depression. As such, we examined RS, five facets of social problem solving, and symptoms of depression in a young adult sample. A total of 180 participants completed measures of RS, social problem solving, and depressive symptoms. We used bootstrapping to examine the indirect effect of RS on depressive symptoms through problem solving. RS was positively associated with depressive symptoms. A negative problem orientation, impulsive/careless style, and avoidance style of social problem solving were positively associated with depressive symptoms, and a positive problem orientation was negatively associated with depressive symptoms. RS demonstrated an indirect effect on depressive symptoms through two social problem-solving facets: the tendency to view problems as threats to one's well-being and an avoidance problem-solving style characterized by procrastination, passivity, or overdependence on others. These results are consistent with prior research that found a positive association between RS and depression symptoms, but this is the first study to implicate specific problem-solving deficits in the relationship between RS and depression. Our results suggest that depressive symptoms in high RS individuals may result from viewing problems as threats and taking an avoidant, rather than proactive, approach to dealing with problems. These findings may have implications for problem-solving interventions for rejection sensitive individuals.

Eutrophication status of the North Sea, Skagerrak, Kattegat and the Baltic Sea in present and future climates: A model study

NASA Astrophysics Data System (ADS)

Skogen, Morten D.; Eilola, Kari; Hansen, Jørgen L. S.; Meier, H. E. Markus; Molchanov, Mikhail S.; Ryabchenko, Vladimir A.

2014-04-01

A method to combine observations and an ensemble of ecological models has been used to assess eutrophication. Using downscaled forcing from two GCMs under the A1B emission scenario, an assessment of the eutrophication status was made for a control (1970-2000) and a future climate (2070-2100) period. By using validation results from a hindcast to compute individual weights between the models, an assessment of eutrophication is done using a set of threshold values. The final classification distinguishes between three categories: problem area, potential problem area, and non-problem area, in accordance with current management practice as suggested by the Oslo and Paris Commissions (OSPAR) and the Helsinki Commission (HELCOM). For the control run the assessment indicates that the Kattegat, the Danish Straits, the Gulf of Finland, the Gotland Basin as well as main parts of the Arkona Basin, the Bornholm Basin, and the Baltic proper may be classified as problem areas. The main part of the North Sea and also the Skagerrak are non-problem areas while the main parts of the Gulf of Bothnia, Gulf of Riga and the entire southeastern continental coast of the North Sea may be classified as potential problem areas. In the future climate scenarios most of the previous potential problem areas in the Baltic Sea have become problem areas, except for the Bothnian Bay where the situation remain fairly unchanged. In the North Sea there seems to be no obvious changes in eutrophication status in the projected future climate.

Pharmacist review and its impact on Singapore nursing homes

PubMed Central

Chia, Hui Shan; Ho, John Aik Hui; Lim, Bernadette Daolin

2015-01-01

INTRODUCTION There is a high prevalence of polypharmacy and inappropriate medication use in Singapore nursing homes. This study primarily explored the benefits of pharmacist reviews in local nursing homes. The secondary aims were to review the potential cost savings gained from following the pharmacists’ recommendations and to identify the possible risks associated with polypharmacy and inappropriate medication use. METHODS A retrospective period prevalence study was performed. We analysed the pharmacotherapy problems highlighted by pharmacists in three nursing homes and the rate of acceptance of pharmacists’ recommendations. Data was collected in two phases: (a) a one-month pre-setup period, during which 480 patients were reviewed (i.e. one-time review before weekly pharmacist visits); and (b) a six-month post-setup period, during which the 480 patients were reviewed again. Pharmacotherapy problems were classified according to a clinical pharmacist recommendation taxonomy and potential risks were identified. Monthly cost savings were calculated and compared with the monthly costs of pharmacist reviews. RESULTS A total of 392 pharmacotherapy problems were identified, with pharmacist recommendations noted for each problem. Among the 392 recommendations, 236 (60.2%) were accepted. The pharmacotherapy problems were analysed for potential risks, including falls (16.0%) and constipation (13.1%). The acceptance rates were higher during the post-setup period compared to the pre-setup period (p < 0.0001). Total direct acquisition cost savings during the pre- and post-setup periods were SGD 388.30 and SGD 876.69, respectively. CONCLUSION The provision of pharmaceutical care to nursing home residents resulted in improved medication safety and quality of care. PMID:26451051

Solving the wrong hierarchy problem

DOE PAGES

Blinov, Nikita; Hook, Anson

2016-06-29

Many theories require augmenting the Standard Model with additional scalar fields with large order one couplings. We present a new solution to the hierarchy problem for these scalar fields. We explore parity- and Z 2-symmetric theories where the Standard Model Higgs potential has two vacua. The parity or Z 2 copy of the Higgs lives in the minimum far from the origin while our Higgs occupies the minimum near the origin of the potential. This approach results in a theory with multiple light scalar fields but with only a single hierarchy problem, since the bare mass is tied to themore » Higgs mass by a discrete symmetry. The new scalar does not have a new hierarchy problem associated with it because its expectation value and mass are generated by dimensional transmutation of the scalar quartic coupling. The location of the second Higgs minimum is not a free parameter, but is rather a function of the matter content of the theory. As a result, these theories are extremely predictive. We develop this idea in the context of a solution to the strong CP problem. Lastly, we show this mechanism postdicts the top Yukawa to be within 1σ of the currently measured value and predicts scalar color octets with masses in the range 9-200 TeV.« less

Students' Experience in a General Chemistry Cooperative Problem Based Laboratory

ERIC Educational Resources Information Center

Sandi-Urena, Santiago; Cooper, Melanie M.; Gatlin, Todd A.; Bhattacharyya, Gautam

2011-01-01

Most educators and scientists would agree that science laboratory instruction has the potential of developing science practices fundamental to achieving scientific literacy. However, there is scant evidence to support that this potential is realized, particularly in tertiary level education. This paper reports qualitative results from a sequential…

Functional analysis and treatment of problem behavior in early education classrooms.

PubMed

Greer, Brian D; Neidert, Pamela L; Dozier, Claudia L; Payne, Steven W; Zonneveld, Kimberley L M; Harper, Amy M

2013-01-01

We conducted functional analyses (FA) with 4 typically developing preschool children during ongoing classroom activities and evaluated treatments that were based on FA results. Results of each child's FA suggested social-positive reinforcement functions, and differential reinforcement of alternative behavior plus time-out was effective in decreasing problem behavior and increasing appropriate behavior. We discuss the utility of classroom-based FAs and potential compromises to experimental control. © Society for the Experimental Analysis of Behavior.

On the solution of the Helmholtz equation on regions with corners.

PubMed

Serkh, Kirill; Rokhlin, Vladimir

2016-08-16

In this paper we solve several boundary value problems for the Helmholtz equation on polygonal domains. We observe that when the problems are formulated as the boundary integral equations of potential theory, the solutions are representable by series of appropriately chosen Bessel functions. In addition to being analytically perspicuous, the resulting expressions lend themselves to the construction of accurate and efficient numerical algorithms. The results are illustrated by a number of numerical examples.

On the solution of the Helmholtz equation on regions with corners

PubMed Central

Serkh, Kirill; Rokhlin, Vladimir

2016-01-01

In this paper we solve several boundary value problems for the Helmholtz equation on polygonal domains. We observe that when the problems are formulated as the boundary integral equations of potential theory, the solutions are representable by series of appropriately chosen Bessel functions. In addition to being analytically perspicuous, the resulting expressions lend themselves to the construction of accurate and efficient numerical algorithms. The results are illustrated by a number of numerical examples. PMID:27482110

Propagation of Axisymmetric Electroelastic Waves in a Hollow Layered Cylinder Under Mechanical Excitation

NASA Astrophysics Data System (ADS)

Grigorenko, A. Ya.; Loza, I. A.

2017-09-01

The problem on propagation of axisymmetric electroelastic waves in a hollow layered cylinder made of metallic and radially polarized piezoceramic layers is solved. The lateral surfaces of the cylinder are free of electrodes. The outside surface is free of mechanical loads, while the inside one undergoes harmonically varying pressure Pe. The problem was solved with a numerical-analytical method. By representing the components of the stress tensor, displacement vectors, electric-flux density, and electrostatic potential by traveling waves, the original electroelastic problem in partial derivatives is reduced to an inhomogeneous boundary-value problem for ordinary differential equations. To solve the problem, the stable numerical discrete-orthogonalization method is used. The results of the kinematic analysis of the layered cylinder both with metallic and piezoceramic (PZT 4) layers are presented. The numerical results are analyzed.

Potencjał turystyczny regionu leszczyńskiego

NASA Astrophysics Data System (ADS)

Zajadacz, Alina; Śniadek, Joanna

2009-01-01

Every Polish region has its own potential, giving each of them development opportunities. For many of the regions potential lies in resources which facilitate tourism development. The main problem is potential recognition and its optimal usage according to adopted strategy. The Leszno Region research results show that this region has potential sufficient to develop tourist brand product within such forms of tourism as: active and specialist tourism, rural tourism, culture tourism, convention tourism and transit tourism.

Development and applications of algorithms for calculating the transonic flow about harmonically oscillating wings

NASA Technical Reports Server (NTRS)

Ehlers, F. E.; Weatherill, W. H.; Yip, E. L.

1984-01-01

A finite difference method to solve the unsteady transonic flow about harmonically oscillating wings was investigated. The procedure is based on separating the velocity potential into steady and unsteady parts and linearizing the resulting unsteady differential equation for small disturbances. The differential equation for the unsteady velocity potential is linear with spatially varying coefficients and with the time variable eliminated by assuming harmonic motion. An alternating direction implicit procedure was investigated, and a pilot program was developed for both two and three dimensional wings. This program provides a relatively efficient relaxation solution without previously encountered solution instability problems. Pressure distributions for two rectangular wings are calculated. Conjugate gradient techniques were developed for the asymmetric, indefinite problem. The conjugate gradient procedure is evaluated for applications to the unsteady transonic problem. Different equations for the alternating direction procedure are derived using a coordinate transformation for swept and tapered wing planforms. Pressure distributions for swept, untaped wings of vanishing thickness are correlated with linear results for sweep angles up to 45 degrees.

Potential interoperability problems facing multi-site radiation oncology centers in The Netherlands

NASA Astrophysics Data System (ADS)

Scheurleer, J.; Koken, Ph; Wessel, R.

2014-03-01

Aim: To identify potential interoperability problems facing multi-site Radiation Oncology (RO) departments in the Netherlands and solutions for unambiguous multi-system workflows. Specific challenges confronting the RO department of VUmc (RO-VUmc), which is soon to open a satellite department, were characterized. Methods: A nationwide questionnaire survey was conducted to identify possible interoperability problems and solutions. Further detailed information was obtained by in-depth interviews at 3 Dutch RO institutes that already operate in more than one site. Results: The survey had a 100% response rate (n=21). Altogether 95 interoperability problems were described. Most reported problems were on a strategic and semantic level. The majority were DICOM(-RT) and HL7 related (n=65), primarily between treatment planning and verification systems or between departmental and hospital systems. Seven were identified as being relevant for RO-VUmc. Departments have overcome interoperability problems with their own, or with tailor-made vendor solutions. There was little knowledge about or utilization of solutions developed by Integrating the Healthcare Enterprise Radiation Oncology (IHE-RO). Conclusions: Although interoperability problems are still common, solutions have been identified. Awareness of IHE-RO needs to be raised. No major new interoperability problems are predicted as RO-VUmc develops into a multi-site department.

Applications of aerospace technology in biology and medicine

NASA Technical Reports Server (NTRS)

1973-01-01

The results are reported of the medically related activities of the NASA Application Team Program at the Research Triangle Institute. Fourteen medical organizations are presently participating in the RTI Application Team Program: The accomplishments of the Research Triangle Institute Application Team during the reporting period were as follows: The team identified 21 new problems for investigation, accomplished 4 technology applications and 3 potential technology applications, closed 21 old problems, and on February 28, 1973, had a total of 57 problems under active investigation.

COMPLEX VARIABLE BOUNDARY ELEMENT METHOD: APPLICATIONS.

USGS Publications Warehouse

Hromadka, T.V.; Yen, C.C.; Guymon, G.L.

1985-01-01

The complex variable boundary element method (CVBEM) is used to approximate several potential problems where analytical solutions are known. A modeling result produced from the CVBEM is a measure of relative error in matching the known boundary condition values of the problem. A CVBEM error-reduction algorithm is used to reduce the relative error of the approximation by adding nodal points in boundary regions where error is large. From the test problems, overall error is reduced significantly by utilizing the adaptive integration algorithm.

NASA Application Team Program: Application of aerospace technology in biology and medicine

NASA Technical Reports Server (NTRS)

1973-01-01

The results of the medically related activities of the NASA Application Team Program in technology application for the reporting period September 1, 1972, to August 31, 1973 are reported. The accomplishments of the application team during the reporting period are as follows: The team has identified 39 new problems for investigation, has accomplished 7 technology applications, 4 potential technology applications, 2 impacts, has closed 38 old problems, and has a total of 59 problems under active investigation.

Applications of aerospace technology in biology and medicine

NASA Technical Reports Server (NTRS)

Brown, J. N.

1974-01-01

The results of the medically related activities of the NASA Application Team Program at the Research Triangle Institute are presented. The RTI team, a multidisciplinary team of scientists and engineers, acted as an information and technology interface between NASA and individuals, institutions, and agencies involved in biomedical research and clinical medicine. The Team has identified 40 new problems for investigation, has accomplished 7 technology applications, 6 potential technology application, 4 impacts, has closed 54 old problems, and has a total of 47 problems under active investigation.

On the potential energy in a gravitationally bound two-body system

NASA Astrophysics Data System (ADS)

Wilhelm, Klaus; Dwivedi, Bhola N.

2015-01-01

The potential energy problem in a gravitationally bound two-body system is studied in the framework of a recently proposed impact model of gravity (Wilhelm et al., 2013). The concept of a closed system has been modified, before the physical processes resulting in the liberation of the potential energy can be described. The energy is extracted from the background flux of hypothetical interaction entities.

Electromagnetic finite elements based on a four-potential variational principle

NASA Technical Reports Server (NTRS)

Schuler, James J.; Felippa, Carlos A.

1991-01-01

Electromagnetic finite elements based on a variational principle that uses the electromagnetic four-potential as a primary variable are derived. This choice is used to construct elements suitable for downstream coupling with mechanical and thermal finite elements for the analysis of electromagnetic/mechanical systems that involve superconductors. The main advantages of the four-potential as a basis for finite element formulation are that the number of degrees of freedom per node remains modest as the problem dimensionally increases, that jump discontinuities on interfaces are naturally accommodated, and that statics as well as dynamics may be treated without any a priori approximations. The new elements are tested on an axisymmetric problem under steady state forcing conditions. The results are in excellent agreement with analytical solutions.

Application of statistical process control and process capability analysis procedures in orbiter processing activities at the Kennedy Space Center

NASA Technical Reports Server (NTRS)

Safford, Robert R.; Jackson, Andrew E.; Swart, William W.; Barth, Timothy S.

1994-01-01

Successful ground processing at KSC requires that flight hardware and ground support equipment conform to specifications at tens of thousands of checkpoints. Knowledge of conformance is an essential requirement for launch. That knowledge of conformance at every requisite point does not, however, enable identification of past problems with equipment, or potential problem areas. This paper describes how the introduction of Statistical Process Control and Process Capability Analysis identification procedures into existing shuttle processing procedures can enable identification of potential problem areas and candidates for improvements to increase processing performance measures. Results of a case study describing application of the analysis procedures to Thermal Protection System processing are used to illustrate the benefits of the approaches described in the paper.

Blow-up behavior of ground states for a nonlinear Schrödinger system with attractive and repulsive interactions

NASA Astrophysics Data System (ADS)

Guo, Yujin; Zeng, Xiaoyu; Zhou, Huan-Song

2018-01-01

We consider a nonlinear Schrödinger system arising in a two-component Bose-Einstein condensate (BEC) with attractive intraspecies interactions and repulsive interspecies interactions in R2. We get ground states of this system by solving a constrained minimization problem. For some kinds of trapping potentials, we prove that the minimization problem has a minimizer if and only if the attractive interaction strength ai (i = 1 , 2) of each component of the BEC system is strictly less than a threshold a*. Furthermore, as (a1 ,a2) ↗ (a* ,a*), the asymptotical behavior for the minimizers of the minimization problem is discussed. Our results show that each component of the BEC system concentrates at a global minimum of the associated trapping potential.

SSME turbopump technology improvements via transient rotordynamic analysis

NASA Technical Reports Server (NTRS)

Childs, D. W.

1975-01-01

The rotordynamic behavior of the high pressure oxygen turbopump and high pressure fuel pump was analyzed for the Space Shuttle Main Engine. The identification of potential rotordynamic problem areas which might arise during operation of these units prior to their testing was accomplished. Alternative procedures for correcting potential rotordynamic problems should they occur were investigated. An adequate analytic and physical understanding of the turbopump rotordynamics was developed to improve the probability of a correct diagnosis of rotordynamic problems from test data. Transient rotordynamic models were developed for both turbopumps. The transient models model the hydrodynamic forces of the turbopump seals. A linear stability analysis was performed for the turbopump rotordynamics models, which included gyroscopic effects, seal forces, speed-dependent bearing characteristics, and internal rotor damping. Results are presented and discussed.

Dealing with aggressive behavior within the health care team: a leadership challenge.

PubMed

Hynes, Patricia; Kissoon, Niranjan; Hamielec, Cindy M; Greene, Anne Marie; Simone, Carmine

2006-06-01

During an interdisciplinary Canadian leadership forum [ (click on the Conferences icon)], participants were challenged to develop an approach to a difficult leadership/management situation. In a scenario involving aggressive behavior among health care providers, participants identified that, before responding, an appropriate leader should collect additional information to identify the core problem(s) causing such behavior. Possibilities include stress; lack of clear roles, responsibilities, and standard operating procedures; and, finally, lack of training on important leadership/management skills. As a result of these core problems, several potential solutions are possible, all with potential obstacles to implementation. Additional education around communication and team interaction was felt to be a priority. In summary, clinical leaders probably have a great deal to gain from augmenting their leadership/management skills.

School-Based Intervention for Social Skills in Children from Divorced Families

ERIC Educational Resources Information Center

Angacian, Sevan; Bray, Melissa A.; Kehle, Thomas J.; Byer-Alcorace, Gabriel; Theodore, Lea A.; Cross, Karen; DeBiase, Emily

2015-01-01

Divorce is an increasingly prevalent occurrence in society that has the potential to result in many adverse short- and long-term consequences for children and their parents. Social skills, such as those with peers, are one of the problems that may emerge for children of divorce. Despite this growing problem, there is a paucity of research…

Parallel tempering for the traveling salesman problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Percus, Allon; Wang, Richard; Hyman, Jeffrey

We explore the potential of parallel tempering as a combinatorial optimization method, applying it to the traveling salesman problem. We compare simulation results of parallel tempering with a benchmark implementation of simulated annealing, and study how different choices of parameters affect the relative performance of the two methods. We find that a straightforward implementation of parallel tempering can outperform simulated annealing in several crucial respects. When parameters are chosen appropriately, both methods yield close approximation to the actual minimum distance for an instance with 200 nodes. However, parallel tempering yields more consistently accurate results when a series of independent simulationsmore » are performed. Our results suggest that parallel tempering might offer a simple but powerful alternative to simulated annealing for combinatorial optimization problems.« less

On the generation of convection in the geomagnetosphere

NASA Astrophysics Data System (ADS)

Sedykh, Pavel

In this paper it has been done a re-examination the consequences of the fact of electric current generation at the bow shock front that we considered at the previous researches [Ponomarev, Sedykh. J. of Atm. Solar-Terr. Phys. Vol. 68. 2006; Ponomarev, Sedykh et al., Geomagn. and Aeron., 2009]. The magnetopause potential Fm is determined from the conditions of balance of the matter coming through the bow shock front and outgoing from the magnetosheath through the magnetopause and space between the bow shock front and magnetopause. This potential differs from the bow shock front potential only in a multiplier. If we assume that the flux tubes are equipotential, the motion of the plasma tube content completely depends on the motion of the tube equatorial trace. Thus, it is sufficient to determine the potential distribution in the equatorial plane within the boundaries, one of which (magnetopause) is represented by parabola with a parameter and the other, by a circle of some radius. The problem is solved in parabolic coordinates, where the Laplace operator seems to be the simplest. The solution is sought in the form of expansion into the series in terms of orthogonal functions in a standard way. The obtained result is also standard. The character of electric field distribution over the dawn-dusk meridian quite corresponds to the classical distribution obtained in [Heppner, 1977]. The significance of this result consists in that the convective electric field (taking into account corotation) was for the first time obtained from the main principles of physics. The power source for maintaining convection was specified, and the boundary conditions at the magnetopause were obtained from the solution of the general problem rather than were specified proceeding from intuitive considerations. The problem of determining the power coming in this case into the magnetosphere is solved as if automatically because vectors of the electric field intensity and density of the electric current are known. We should merely integrate the product of these quantities over the volume of the magnetosphere. Finally, one can note that the energy flux into the magnetosphere is closely related to the current through the magnetosphere by the well-known relationship. The problem of generation of convection in the magnetosphere proved to be the most advanced and independent of paradigm among all magnetospheric problems. The results obtained by us do not differ from the known results. The electric field along the bow shock front and the potential depend on the solar wind velocity normal component and on the IMF tangential component and may be defined by the formulas.

Novel nonlinear knowledge-based mean force potentials based on machine learning.

PubMed

Dong, Qiwen; Zhou, Shuigeng

2011-01-01

The prediction of 3D structures of proteins from amino acid sequences is one of the most challenging problems in molecular biology. An essential task for solving this problem with coarse-grained models is to deduce effective interaction potentials. The development and evaluation of new energy functions is critical to accurately modeling the properties of biological macromolecules. Knowledge-based mean force potentials are derived from statistical analysis of proteins of known structures. Current knowledge-based potentials are almost in the form of weighted linear sum of interaction pairs. In this study, a class of novel nonlinear knowledge-based mean force potentials is presented. The potential parameters are obtained by nonlinear classifiers, instead of relative frequencies of interaction pairs against a reference state or linear classifiers. The support vector machine is used to derive the potential parameters on data sets that contain both native structures and decoy structures. Five knowledge-based mean force Boltzmann-based or linear potentials are introduced and their corresponding nonlinear potentials are implemented. They are the DIH potential (single-body residue-level Boltzmann-based potential), the DFIRE-SCM potential (two-body residue-level Boltzmann-based potential), the FS potential (two-body atom-level Boltzmann-based potential), the HR potential (two-body residue-level linear potential), and the T32S3 potential (two-body atom-level linear potential). Experiments are performed on well-established decoy sets, including the LKF data set, the CASP7 data set, and the Decoys “R”Us data set. The evaluation metrics include the energy Z score and the ability of each potential to discriminate native structures from a set of decoy structures. Experimental results show that all nonlinear potentials significantly outperform the corresponding Boltzmann-based or linear potentials, and the proposed discriminative framework is effective in developing knowledge-based mean force potentials. The nonlinear potentials can be widely used for ab initio protein structure prediction, model quality assessment, protein docking, and other challenging problems in computational biology.

Visualizing request-flow comparison to aid performance diagnosis in distributed systems.

PubMed

Sambasivan, Raja R; Shafer, Ilari; Mazurek, Michelle L; Ganger, Gregory R

2013-12-01

Distributed systems are complex to develop and administer, and performance problem diagnosis is particularly challenging. When performance degrades, the problem might be in any of the system's many components or could be a result of poor interactions among them. Recent research efforts have created tools that automatically localize the problem to a small number of potential culprits, but research is needed to understand what visualization techniques work best for helping distributed systems developers understand and explore their results. This paper compares the relative merits of three well-known visualization approaches (side-by-side, diff, and animation) in the context of presenting the results of one proven automated localization technique called request-flow comparison. Via a 26-person user study, which included real distributed systems developers, we identify the unique benefits that each approach provides for different problem types and usage modes.

Effect of Trapped Ions on Shielding and Floating Potential of a Dust Grain in a Plasma

NASA Astrophysics Data System (ADS)

Lampe, Martin; Ganguli, Gurudas; Joyce, Glenn; Gavrishchaka, Valeriy

2001-10-01

The problem of electrostatic shielding around a small spherical collector immersed in plasma, and the related problem of electron and ion flow to the collector, date to the origins of plasma physics. Beginning with Mott-Smith and Langmuir (1926), calculations have typically neglected collisions, on the grounds that the mean free path is long compared to shielding length scales, i.e. the Debye length. However, investigators beginning with Bernstein and Rabinowitz (1959) have known that negative-energy trapped ions, created by occasional collisions, might be important. We present an analytic calculation of the density of trapped and untrapped ions, self-consistent with the potential. Under typical conditions for dust grains immersed in a discharge plasma, trapped ions dominate the shielding cloud in steady state, even in the limit of very long mean free path. As a result the shielded potential is different from the results of orbital motion limited theory. Collisions also greatly increase the ion current to the collector, thereby decreasing the floating potential and the grain charge by a factor as large as two to three.

Module Hipot and ground continuity test results

NASA Technical Reports Server (NTRS)

Griffith, J. S.

1984-01-01

Hipot (high voltage potential) and module frame continuity tests of solar energy conversion modules intended for deployment into large arrays are discussed. The purpose of the tests is to reveal potentially hazardous voltage conditions in installed modules, and leakage currents that may result in loss of power or cause ground fault system problems, i.e., current leakage potential and leakage voltage distribution. The tests show a combined failure rate of 36% (69% when environmental testing is included). These failure rates are believed easily corrected by greater care in fabrication.

Weak solution concept and Galerkin's matrix for the exterior of an oblate ellipsoid of revolution in the representation of the Earth's gravity potential by buried masses

NASA Astrophysics Data System (ADS)

Holota, Petr; Nesvadba, Otakar

2017-04-01

The paper is motivated by the role of boundary value problems in Earth's gravity field studies. The discussion focuses on Neumann's problem formulated for the exterior of an oblate ellipsoid of revolution as this is considered a basis for an iteration solution of the linear gravimetric boundary value problem in the determination of the disturbing potential. The approach follows the concept of the weak solution and Galerkin's approximations are applied. This means that the solution of the problem is approximated by linear combinations of basis functions with scalar coefficients. The construction of Galerkin's matrix for basis functions generated by elementary potentials (point masses) is discussed. Ellipsoidal harmonics are used as a natural tool and the elementary potentials are expressed by means of series of ellipsoidal harmonics. The problem, however, is the summation of the series that represent the entries of Galerkin's matrix. It is difficult to reduce the number of summation indices since in the ellipsoidal case there is no analogue to the addition theorem known for spherical harmonics. Therefore, the straightforward application of series of ellipsoidal harmonics is complemented by deeper relations contained in the theory of ordinary differential equations of second order and in the theory of Legendre's functions. Subsequently, also hypergeometric functions and series are used. Moreover, within some approximations the entries are split into parts. Some of the resulting series may be summed relatively easily, apart from technical tricks. For the remaining series the summation was converted to elliptic integrals. The approach made it possible to deduce a closed (though approximate) form representation of the entries in Galerkin's matrix. The result rests on concepts and methods of mathematical analysis. In the paper it is confronted with a direct numerical approach applied for the implementation of Legendre's functions. The computation of the entries is more demanding in this case, but conceptually it avoids approximations. Finally, some specific features associated with function bases generated by elementary potentials in case the ellipsoidal solution domain are illustrated and discussed.

Application of Particle Swarm Optimization Algorithm in the Heating System Planning Problem

PubMed Central

Ma, Rong-Jiang; Yu, Nan-Yang; Hu, Jun-Yi

2013-01-01

Based on the life cycle cost (LCC) approach, this paper presents an integral mathematical model and particle swarm optimization (PSO) algorithm for the heating system planning (HSP) problem. The proposed mathematical model minimizes the cost of heating system as the objective for a given life cycle time. For the particularity of HSP problem, the general particle swarm optimization algorithm was improved. An actual case study was calculated to check its feasibility in practical use. The results show that the improved particle swarm optimization (IPSO) algorithm can more preferably solve the HSP problem than PSO algorithm. Moreover, the results also present the potential to provide useful information when making decisions in the practical planning process. Therefore, it is believed that if this approach is applied correctly and in combination with other elements, it can become a powerful and effective optimization tool for HSP problem. PMID:23935429

Exposure to and engagement with gambling marketing in social media: Reported impacts on moderate-risk and problem gamblers.

PubMed

Gainsbury, Sally M; King, Daniel L; Russell, Alex M T; Delfabbro, Paul; Derevensky, Jeffrey; Hing, Nerilee

2016-03-01

Digital advertising for gambling and specifically marketing via social media have increased in recent years, and the impact on vulnerable consumers, including moderate-risk and problem gamblers, is unknown. Social media promotions often fall outside of advertising restrictions and codes of conduct and may have an inequitable effect on susceptible gamblers. This study aimed to investigate recall of exposure to, and reported impact on gamblers of, gambling promotions and marketing content on social media, with a focus on vulnerable users currently experiencing gambling problems. Gamblers who use social media (N = 964) completed an online survey assessing their exposure to and engagement with gambling operators on social media, their problem gambling severity, and the impact of social media promotions on their gambling. Gamblers at moderate risk and problem gamblers were significantly more likely to report having been exposed to social media gambling promotions and indicated actively engaging with gambling operators via these platforms. They were more likely to self-report that they had increased gambling as a result of these promotions, and over one third reported that the promotions had increased their problems. This research suggests that gamblers at moderate risk or those experiencing gambling problems are more likely to be impacted by social media promotions, and these may play a role in exacerbating disordered gambling. Future research should verify these self-reported results with behavioral data. However, the potential influence of advertisements via these new platforms should be considered by clinicians and policymakers, given their potential role in the formation of this behavioral addiction. (c) 2016 APA, all rights reserved).

Initial results on fault diagnosis of DSN antenna control assemblies using pattern recognition techniques

NASA Technical Reports Server (NTRS)

Smyth, P.; Mellstrom, J.

1990-01-01

Initial results obtained from an investigation using pattern recognition techniques for identifying fault modes in the Deep Space Network (DSN) 70 m antenna control loops are described. The overall background to the problem is described, the motivation and potential benefits of this approach are outlined. In particular, an experiment is described in which fault modes were introduced into a state-space simulation of the antenna control loops. By training a multilayer feed-forward neural network on the simulated sensor output, classification rates of over 95 percent were achieved with a false alarm rate of zero on unseen tests data. It concludes that although the neural classifier has certain practical limitations at present, it also has considerable potential for problems of this nature.

A hybrid computer program for rapidly solving flowing or static chemical kinetic problems involving many chemical species

NASA Technical Reports Server (NTRS)

Mclain, A. G.; Rao, C. S. R.

1976-01-01

A hybrid chemical kinetic computer program was assembled which provides a rapid solution to problems involving flowing or static, chemically reacting, gas mixtures. The computer program uses existing subroutines for problem setup, initialization, and preliminary calculations and incorporates a stiff ordinary differential equation solution technique. A number of check cases were recomputed with the hybrid program and the results were almost identical to those previously obtained. The computational time saving was demonstrated with a propane-oxygen-argon shock tube combustion problem involving 31 chemical species and 64 reactions. Information is presented to enable potential users to prepare an input data deck for the calculation of a problem.

Assessment of Students’ Critical-Thinking and Problem-Solving Abilities Across a 6-Year Doctor of Pharmacy Program

PubMed Central

Gaebelein, Claude J.; Grice, Gloria R.; Crannage, Andrew J.; Weck, Margaret A.; Hurd, Peter; Walter, Brenda; Duncan, Wendy

2013-01-01

Objective. To determine the feasibility of using a validated set of assessment rubrics to assess students’ critical-thinking and problem-solving abilities across a doctor of pharmacy (PharmD) curriculum. Methods. Trained faculty assessors used validated rubrics to assess student work samples for critical-thinking and problem-solving abilities. Assessment scores were collected and analyzed to determine student achievement of these 2 ability outcomes across the curriculum. Feasibility of the process was evaluated in terms of time and resources used. Results. One hundred sixty-one samples were assessed for critical thinking, and 159 samples were assessed for problem-solving. Rubric scoring allowed assessors to evaluate four 5- to 7-page work samples per hour. The analysis indicated that overall critical-thinking scores improved over the curriculum. Although low yield for problem-solving samples precluded meaningful data analysis, it was informative for identifying potentially needed curricular improvements. Conclusions. Use of assessment rubrics for program ability outcomes was deemed authentic and feasible. Problem-solving was identified as a curricular area that may need improving. This assessment method has great potential to inform continuous quality improvement of a PharmD program. PMID:24159207

Observable indicators and behaviors for the identification of problem gamblers in venue environments

PubMed Central

Delfabbro, Paul; Thomas, Anna

2016-01-01

Background and aims In many jurisdictions, where gambling services are provided, regulatory codes require gambling operators to apply a duty of care toward patrons. A common feature of these provisions is some expectation that venue staff identify and assist patrons who might be experiencing problems with their gambling. The effectiveness of such measures is, however, predicated on the assumption that there are reliable and observable indicators that might be used to allow problem gamblers to be distinguished from other gamblers. Methods In this study, we consolidate the findings from two large Australian studies (n = 505 and n = 680) of regular gamblers that were designed to identify reliable and useful indicators for identifying problem gambling in venues. Results It was found that problem gamblers are much more likely to report potentially visible emotional reactions, unusual social behaviors, and very intense or frenetic gambling behavior. Discussion and conclusions This study shows that there are a range of indicators that could potentially be used to identify people experiencing problems in venues, but that decisions are most likely to be accurate if based on an accumulation of a diverse range of indicators. PMID:27670713

Behavior problems, foster home integration, and evidence-based behavioral interventions: What predicts adoption of foster children?

PubMed Central

Leathers, Sonya J.; Spielfogel, Jill E.; Gleeson, James P.; Rolock, Nancy

2015-01-01

Objectives Adoption is particularly important for foster children with special mental health needs who are unable to return home, as adoption increases parental support often critically needed by youth with mental health issues. Unfortunately, significant behavior problems frequently inhibit foster parents from adopting, and little is known about factors that predict adoption when a child has behavior problems. Previous research suggests that foster parent behavioral training could potentially increase rates of successful adoptions for pre-school-aged foster children with behavior problems (Fisher, Kim, & Pears, 2009), but this has not been previously tested in older samples. In older children, effective treatment of behavior problems might also increase adoption by reducing the interference of behavior problems and strengthening the child’s foster home integration. This pilot study focused on this question by testing associations between behavior problems, foster home integration, an evidence-based foster parent intervention, and adoption likelihood. Methods This study used an intent-to-treat design to compare foster home integration and adoption likelihood for 31 foster children with histories of abuse and neglect whose foster parents received a foster behavioral parenting intervention (see Chamberlain, 2003) or usual services. Random effect regression analyses were used to estimate outcomes across four time points. Results As expected, externalizing behavior problems had a negative effect on both integration and adoption, and foster home integration had an independent positive effect on adoption. Internalizing behavior problems (e.g., depression/anxiety) were not related to adoption or integration. However, the intervention did not have a direct effect on either foster home integration or adoption despite its positive effect on behavior problems. Conclusions Results from this preliminary study provide further evidence of the negative effect of externalizing behavior problems on adoption. Its findings also suggest that foster home integration is an important dimension of foster home adaptation that appears particularly relevant to chances for adoption. While behavior problems appear to weaken foster home integration, integration is also an independent predictor of adoption likelihood. If these results are replicated in a larger study, consideration of foster home integration in case planning and future intervention studies focused on increasing permanency could potentially improve outcomes for foster children with behavior problems. PMID:26617425

Mindfulness Facets, Social Anxiety, and Drinking to Cope with Social Anxiety: Testing Mediators of Drinking Problems.

PubMed

Clerkin, Elise M; Sarfan, Laurel D; Parsons, E Marie; Magee, Joshua C

2017-02-01

This cross-sectional study tested social anxiety symptoms, trait mindfulness, and drinking to cope with social anxiety as potential predictors and/or serial mediators of drinking problems. A community-based sample of individuals with co-occurring social anxiety symptoms and alcohol dependence were recruited. Participants ( N = 105) completed measures of social anxiety, drinking to cope with social anxiety, and alcohol use and problems. As well, participants completed the Five Facet Mindfulness Questionnaire , which assesses mindfulness facets of accepting without judgment, acting with awareness, not reacting to one's internal experiences, observing and attending to experiences, and labeling and describing. As predicted, the relationship between social anxiety symptoms and drinking problems was mediated by social anxiety coping motives across each of the models. Further, the relationship between specific mindfulness facets (acting with awareness, accepting without judgment, and describe) and drinking problems was serially mediated by social anxiety symptoms and drinking to cope with social anxiety. This research builds upon existing studies that have largely been conducted with college students to evaluate potential mediators driving drinking problems. Specifically, individuals who are less able to act with awareness, accept without judgment, and describe their internal experiences may experience heightened social anxiety and drinking to cope with that anxiety, which could ultimately result in greater alcohol-related problems.

The potentials and problems of private sector transportation services : activities in the New York region

DOT National Transportation Integrated Search

1987-01-01

This project explored the problems and potentials of new forms of private urban transportation that have evolved in the Metropolitan New York region in the last 20 years, as well as the problems and potentials of private urban bus service that has ex...

Full-Potential Modeling of Blade-Vortex Interactions. Degree awarded by George Washington Univ., Feb. 1987

NASA Technical Reports Server (NTRS)

Jones, Henry E.

1997-01-01

A study of the full-potential modeling of a blade-vortex interaction was made. A primary goal of this study was to investigate the effectiveness of the various methods of modeling the vortex. The model problem restricts the interaction to that of an infinite wing with an infinite line vortex moving parallel to its leading edge. This problem provides a convenient testing ground for the various methods of modeling the vortex while retaining the essential physics of the full three-dimensional interaction. A full-potential algorithm specifically tailored to solve the blade-vortex interaction (BVI) was developed to solve this problem. The basic algorithm was modified to include the effect of a vortex passing near the airfoil. Four different methods of modeling the vortex were used: (1) the angle-of-attack method, (2) the lifting-surface method, (3) the branch-cut method, and (4) the split-potential method. A side-by-side comparison of the four models was conducted. These comparisons included comparing generated velocity fields, a subcritical interaction, and a critical interaction. The subcritical and critical interactions are compared with experimentally generated results. The split-potential model was used to make a survey of some of the more critical parameters which affect the BVI.

Legal Problems in Higher Education. Bureau of School Service Bulletin; Vol. 46; No. 3; March 1974.

ERIC Educational Resources Information Center

Burnett, Collins W., Ed.

The Legal Problems in Higher Education seminar had as an objective to help the student who may become a college administrator or a college teacher to develop a sensitivity to any situation that potentially could become a legal matter and perhaps result in a court case. The seminar papers are arranged in 3 clusters: students, faculty, and…

Proceedings of the Toronto TEAM/ACES workshop

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, L.R.

The third TEAM Workshop of the third round was held at Ontario Hydro in Toronto 25--26 October 1990, immediately following the Conference on Electromagnetic Field Computation. This was the first Joint Workshop with ACES (Applied Computational Electromagnetics Society), whose goals are similar to TEAM, but who tend to work at higher frequencies (Antennas, Propagation, and Scattering). A fusion problem, the eddy current heating of the case of the Euratom Large Coil Project Coil, was adapted as Problem 14 at the Oxford Workshop, and a solution to that problem was presented at Toronto by Oskar Biro of the Graz (Austria) Universitymore » of Technology. Individual solutions were also presented for Problems 8 (Flaw in a Plate) and 9 (Moving Coil inside a Pipe). Five new solutions were presented to Problem 13 (DC Coil in a Ferromagnetic Yoke), and Koji Fujiwara of Okayama University summarized these solutions along with the similar number presented at Oxford. The solutions agreed well in the air but disagreed in the steel. Codes with a formulation in magnetic field strength or scalar potential underestimated the flux density in the steel, and codes based on flux density or vector potential overestimated it. Codes with edge elements appeared to do better than codes with nodal elements. These results stimulated considerable discussions; in my view that was the most valuable result of the workshop.« less

An equivalent domain integral method for three-dimensional mixed-mode fracture problems

NASA Technical Reports Server (NTRS)

Shivakumar, K. N.; Raju, I. S.

1991-01-01

A general formulation of the equivalent domain integral (EDI) method for mixed mode fracture problems in cracked solids is presented. The method is discussed in the context of a 3-D finite element analysis. The J integral consists of two parts: the volume integral of the crack front potential over a torus enclosing the crack front and the crack surface integral due to the crack front potential plus the crack face loading. In mixed mode crack problems the total J integral is split into J sub I, J sub II, and J sub III representing the severity of the crack front in three modes of deformations. The direct and decomposition methods are used to separate the modes. These two methods were applied to several mixed mode fracture problems, were analyzed, and results were found to agree well with those available in the literature. The method lends itself to be used as a post-processing subroutine in a general purpose finite element program.

An equivalent domain integral method for three-dimensional mixed-mode fracture problems

NASA Technical Reports Server (NTRS)

Shivakumar, K. N.; Raju, I. S.

1992-01-01

A general formulation of the equivalent domain integral (EDI) method for mixed mode fracture problems in cracked solids is presented. The method is discussed in the context of a 3-D finite element analysis. The J integral consists of two parts: the volume integral of the crack front potential over a torus enclosing the crack front and the crack surface integral due to the crack front potential plus the crack face loading. In mixed mode crack problems the total J integral is split into J sub I, J sub II, and J sub III representing the severity of the crack front in three modes of deformations. The direct and decomposition methods are used to separate the modes. These two methods were applied to several mixed mode fracture problems, were analyzed, and results were found to agree well with those available in the literature. The method lends itself to be used as a post-processing subroutine in a general purpose finite element program.

Problem-Based Learning and Earth System Science - The ESSEA High School Earth System Science Online Course

NASA Astrophysics Data System (ADS)

Myers, R.; Botti, J.

2002-12-01

The high school Earth system science course is web based and designed to meet the professional development needs of science teachers in grades 9-12. Three themes predominate this course: Earth system science (ESS) content, collaborative investigations, and problem-based learning (PBL) methodology. PBL uses real-world contexts for in-depth investigations of a subject matter. Participants predict the potential impacts of the selected event on Earth's spheres and the subsequent feedback and potential interactions that might result. PBL activities start with an ill-structured problem that serves as a springboard to team engagement. These PBL scenarios contain real-world situations. Teams of learners conduct an Earth system science analysis of the event and make recommendations or offer solutions regarding the problem. The course design provides an electronic forum for conversations, debate, development, and application of ideas. Samples of threaded discussions built around ESS thinking in science and PBL pedagogy will be presented.

Problem-Based Learning and Earth System Science - The ESSEA High School Earth System Science Online Course

NASA Astrophysics Data System (ADS)

Myers, R. J.; Botti, J. A.

2001-12-01

The high school Earth system science course is web based and designed to meet the professional development needs of science teachers in grades 9-12. Three themes predominate this course: Earth system science (ESS) content, collaborative investigations, and problem-based learning (PBL) methodology. PBL uses real-world contexts for in-depth investigations of a subject matter. Participants predict the potential impacts of the selected event on Earth's spheres and the subsequent feedback and potential interactions that might result. PBL activities start with an ill-structured problem that serves as a springboard to team engagement. These PBL scenarios contain real-world situations. Teams of learners conduct an Earth system science analysis of the event and make recommendations or offer solutions regarding the problem. The course design provides an electronic forum for conversations, debate, development, and application of ideas. Samples of threaded discussions built around ESS thinking in science and PBL pedagogy will be presented.

Do nurses who work in a fair organization sleep and perform better and why? Testing potential psychosocial mediators of organizational justice.

PubMed

Hietapakka, Laura; Elovainio, Marko; Heponiemi, Tarja; Presseau, Justin; Eccles, Martin; Aalto, Anna-Mari; Pekkarinen, Laura; Kuokkanen, Liisa; Sinervo, Timo

2013-10-01

We examined whether organizational justice is associated with sleep quality and performance in a population-based sample of 1,729 Finnish registered nurses working full time. In addition, we tested psychological mechanisms mediating the potential association. The results of multivariate linear regression analyses showed higher organizational justice to be associated with fewer sleeping problems (β values range from -.20 to -.11) and higher self-reported performance (β values range from .05 to .35). Furthermore, psychological distress (related to the psychological stress model) and job involvement (related to the psychosocial resource model) mediated the association between organizational justice and sleep. Sleeping problems partly mediated the association between organizational justice and performance. Psychological distress explained 51% to 83% and job involvement explained 10% to 15% of the total effects of justice variables on sleeping problems. The findings provide support for the psychological stress model and offer practical implications for reducing nurses' sleeping problems.

Coal conversion: description of technologies and necessary biomedical and environmental research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1976-08-01

This document contains a description of the biomedical and environmental research necessary to ensure the timely attainment of coal conversion technologies amenable to man and his environment. The document is divided into three sections. The first deals with the types of processes currently being considered for development; the data currently available on composition of product, process and product streams, and their potential effects; and problems that might arise from transportation and use of products. Section II is concerned with a description of the necessary research in each of the King-Muir categories, while the third section presents the research strategies necessarymore » to assess the potential problems at the conversion plant (site specific) and those problems that might effect the general public and environment as a result of the operation of large-scale coal conversion plants.« less

Balanced program plan. Volume IV. Coal conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richmond, C. R.; Reichle, D. E.; Gehrs, C. W.

1976-05-01

This document contains a description of the biomedical and environmental research necessary to ensure the timely attainment of coal conversion technologies amenable to man and his environment. The document is divided into three sections. The first deals with the types of processes currently being considered for development; the data currently available on composition of product, process and product streams, and their potential effects; and problems that might arise from transportation and use of products. Section II is concerned with a description of the necessary research in each of the King-Muir categories, while the third section presents the research strategies necessarymore » to assess the potential problems at the conversion plant (site specific) and those problems that might effect the general public and environment as a result of the operation of large-scale coal conversion plants. (auth)« less

Balanced program plan. Volume 4. Coal conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1976-05-01

This document contains a description of the biomedical and environmental research necessary to ensure the timely attainment of coal conversion technologies amenable to man and his environment. The document is divided into three sections. The first deals with the types of processes currently being considered for development; the data currently available on composition of product, process and product streams, and their potential effects; and problems that might arise from transportation and use of products. Section II is concerned with a description of the necessary research in each of the King-Muir categories, while the third section presents the research strategies necessarymore » to assess the potential problems at the conversion plant (site specific) and those problems that might effect the general public and environment as a result of the operation of large-scale coal conversion plants.« less

Application of L1-norm regularization to epicardial potential reconstruction based on gradient projection.

PubMed

Wang, Liansheng; Qin, Jing; Wong, Tien Tsin; Heng, Pheng Ann

2011-10-07

The epicardial potential (EP)-targeted inverse problem of electrocardiography (ECG) has been widely investigated as it is demonstrated that EPs reflect underlying myocardial activity. It is a well-known ill-posed problem as small noises in input data may yield a highly unstable solution. Traditionally, L2-norm regularization methods have been proposed to solve this ill-posed problem. But the L2-norm penalty function inherently leads to considerable smoothing of the solution, which reduces the accuracy of distinguishing abnormalities and locating diseased regions. Directly using the L1-norm penalty function, however, may greatly increase computational complexity due to its non-differentiability. We propose an L1-norm regularization method in order to reduce the computational complexity and make rapid convergence possible. Variable splitting is employed to make the L1-norm penalty function differentiable based on the observation that both positive and negative potentials exist on the epicardial surface. Then, the inverse problem of ECG is further formulated as a bound-constrained quadratic problem, which can be efficiently solved by gradient projection in an iterative manner. Extensive experiments conducted on both synthetic data and real data demonstrate that the proposed method can handle both measurement noise and geometry noise and obtain more accurate results than previous L2- and L1-norm regularization methods, especially when the noises are large.

Mixed problems for the Korteweg-de Vries equation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faminskii, A V

1999-06-30

Results are established concerning the non-local solubility and wellposedness in various function spaces of the mixed problem for the Korteweg-de Vries equation u{sub t}+u{sub xxx}+au{sub x}+uu{sub x}=f(t,x) in the half-strip (0,T)x(-{infinity},0). Some a priori estimates of the solutions are obtained using a special solution J(t,x) of the linearized KdV equation of boundary potential type. Properties of J are studied which differ essentially as x{yields}+{infinity} or x{yields}-{infinity}. Application of this boundary potential enables us in particular to prove the existence of generalized solutions with non-regular boundary values.

Pedagogy and/or technology: Making difference in improving students' problem solving skills

NASA Astrophysics Data System (ADS)

Hrepic, Zdeslav; Lodder, Katherine; Shaw, Kimberly A.

2013-01-01

Pen input computers combined with interactive software may have substantial potential for promoting active instructional methodologies and for facilitating students' problem solving ability. An excellent example is a study in which introductory physics students improved retention, conceptual understanding and problem solving abilities when one of three weekly lectures was replaced with group problem solving sessions facilitated with Tablet PCs and DyKnow software [1,2]. The research goal of the present study was to isolate the effect of the methodology itself (using additional time to teach problem solving) from that of the involved technology. In Fall 2011 we compared the performance of students taking the same introductory physics lecture course while enrolled in two separate problem-solving sections. One section used pen-based computing to facilitate group problem solving while the other section used low-tech methods for one third of the semester (covering Kinematics), and then traded technologies for the middle third of the term (covering Dynamics). Analysis of quiz, exam and standardized pre-post test results indicated no significant difference in scores of the two groups. Combining this result with those of previous studies implies primacy of pedagogy (collaborative problem solving itself) over technology for student learning in problem solving recitations.

Operationally Efficient Propulsion System Study (OEPSS) data book. Volume 2: Ground operations problems

NASA Technical Reports Server (NTRS)

Waldrop, Glen S.

1990-01-01

Operations problems and cost drivers were identified for current propulsion systems and design and technology approaches were identified to increase the operational efficiency and to reduce operations costs for future propulsion systems. To provide readily usable data for the ALS program, the results of the OEPSS study were organized into a series of OEPSS Data Books. This volume presents a detailed description of 25 major problems encountered during launch processing of current expendable and reusable launch vehicles. A concise description of each problem and its operational impact on launch processing is presented, along with potential solutions and technology recommendation.

On stress analysis of a crack-layer

NASA Technical Reports Server (NTRS)

Chudnovsky, A.; Dolgopolsky, A.; Kachanov, M.

1984-01-01

This work considers the problem of elastic interaction of a macrocrack with an array of microcracks in the vicinity of the macrocrack tip. Using the double layer potential techniques, the solution to the problem within the framework of the plane problem of elastostatics has been obtained. Three particular problems of interest to fracture mechanics have been analyzed. It follows from analysis that microcrack array can either amplify or reduce the resulting stress field of the macrocrack-microcrack array system depending on the array's configuration. Using the obtained elastic solution the energy release rate associated with the translational motion of the macrocrack-microcrack array system has been evaluated.

The Development of B2C E-Commerce in Greece: Current Situation and Future Potential.

ERIC Educational Resources Information Center

Kardaras, Dimitris; Papathanassiou, Eleutherios

2000-01-01

Reports on the results of a survey of 120 companies in Greece that evaluated the potential of business to customer (B2C) Internet applications and investigated how the Internet and e-commerce can offer new opportunities for businesses to improve their customers' satisfaction. Discusses electronic commerce problems and future technology. (Contains…

Direct solution of the H(1s)-H + long-range interaction problem in momentum space

NASA Astrophysics Data System (ADS)

Koga, Toshikatsu

1985-02-01

Perturbation equations for the H(1s)-H+ long-range interaction are solved directly in momentum space up to the fourth order with respect to the reciprocal of the internuclear distance. As in the hydrogen atom problem, the Fock transformation is used which projects the momentum vector of an electron from the three-dimensional hyperplane onto the four-dimensional hypersphere. Solutions are given as linear combinations of several four-dimensional spherical harmonics. The present results add an example to the momentum-space solution of the nonspherical potential problem.

Behavior problems, foster home integration, and evidence-based behavioral interventions: What predicts adoption of foster children?

PubMed

Leathers, Sonya J; Spielfogel, Jill E; Gleeson, James P; Rolock, Nancy

2012-05-01

Adoption is particularly important for foster children with special mental health needs who are unable to return home, as adoption increases parental support often critically needed by youth with mental health issues. Unfortunately, significant behavior problems frequently inhibit foster parents from adopting, and little is known about factors that predict adoption when a child has behavior problems. Previous research suggests that foster parent behavioral training could potentially increase rates of successful adoptions for pre-school-aged foster children with behavior problems (Fisher, Kim, & Pears, 2009), but this has not been previously tested in older samples. In older children, effective treatment of behavior problems might also increase adoption by reducing the interference of behavior problems and strengthening the child's foster home integration. This pilot study focused on this question by testing associations between behavior problems, foster home integration, an evidence-based foster parent intervention, and adoption likelihood. This study used an intent-to-treat design to compare foster home integration and adoption likelihood for 31 foster children with histories of abuse and neglect whose foster parents received a foster behavioral parenting intervention (see Chamberlain, 2003) or usual services. Random effect regression analyses were used to estimate outcomes across four time points. As expected, externalizing behavior problems had a negative effect on both integration and adoption, and foster home integration had an independent positive effect on adoption. Internalizing behavior problems (e.g., depression/anxiety) were not related to adoption or integration. However, the intervention did not have a direct effect on either foster home integration or adoption despite its positive effect on behavior problems. Results from this preliminary study provide further evidence of the negative effect of externalizing behavior problems on adoption. Its findings also suggest that foster home integration is an important dimension of foster home adaptation that appears particularly relevant to chances for adoption. While behavior problems appear to weaken foster home integration, integration is also an independent predictor of adoption likelihood. If these results are replicated in a larger study, consideration of foster home integration in case planning and future intervention studies focused on increasing permanency could potentially improve outcomes for foster children with behavior problems.

Frequency and nature of potentially harmful preventable problems in primary care from the patient's perspective with clinician review: a population-level survey in Great Britain.

PubMed

Stocks, Susan Jill; Donnelly, Ailsa; Esmail, Aneez; Beresford, Joanne; Luty, Sarah; Deacon, Richard; Danczak, Avril; Mann, Nicola; Townsend, David; Ashley, James; Gamble, Carolyn; Bowie, Paul; Campbell, Stephen M

2018-06-13

To estimate the frequency of patient-perceived potentially harmful problems occurring in primary care. To describe the type of problem, patient predictors of perceiving a problem, the primary care service involved, how the problem was discussed and patient suggestions as to how the problem might have been prevented. To describe clinician/public opinions regarding the likelihood that the patient-described scenario is potentially harmful. Population-level survey. Great Britain. A nationally representative sample of 3975 members of the public aged ≥15 years interviewed during April 2016. Counts of patient-perceived potentially harmful problems in the last 12 months, descriptions of patient-described scenarios and review by clinicians/members of the public. 3975 of 3996 participants in a nationally representative survey completed the relevant questions (99.5%). 300 (7.6%; 95% CI 6.7% to 8.4%) of respondents reported experiencing a potentially harmful preventable problem in primary care during the past 12 months and 145 (48%) discussed their concerns within primary care. This did not vary with age, gender or type of service used. A substantial minority (30%) of the patient-perceived problems occurred outside general practice, particularly the dental surgery, walk in clinic, out of hours care and pharmacy. Patients perceiving a potentially harmful preventable problem were eight times more likely to have 'no confidence and trust in primary care' compared with 'yes, definitely' (OR 7.9; 95% CI 5.9 to 10.7) but those who discussed their perceived-problem appeared to maintain higher trust and confidence. Generally, clinicians ranked the patient-described scenarios as unlikely to be potentially harmful. This study highlights the importance of actively soliciting patient's views about preventable harm in primary care as patients frequently perceive potentially harmful preventable problems and make useful suggestions for their prevention. Such engagement may also help to improve confidence and trust in primary care. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Interstate Groundwater Management Preference Differences: The Ogallala Region.

ERIC Educational Resources Information Center

Kromm, David E.; White, Stephen E.

1987-01-01

Describes the changes taking place as a result of the depletion of groundwater supplied by the Ogallala aquifer. Provides maps and tables which show changes occurring in agriculture, and reports the results of a survey of residents' opinions on potential solutions to the problem. (JDH)

Vectorization and parallelization of the finite strip method for dynamic Mindlin plate problems

NASA Technical Reports Server (NTRS)

Chen, Hsin-Chu; He, Ai-Fang

1993-01-01

The finite strip method is a semi-analytical finite element process which allows for a discrete analysis of certain types of physical problems by discretizing the domain of the problem into finite strips. This method decomposes a single large problem into m smaller independent subproblems when m harmonic functions are employed, thus yielding natural parallelism at a very high level. In this paper we address vectorization and parallelization strategies for the dynamic analysis of simply-supported Mindlin plate bending problems and show how to prevent potential conflicts in memory access during the assemblage process. The vector and parallel implementations of this method and the performance results of a test problem under scalar, vector, and vector-concurrent execution modes on the Alliant FX/80 are also presented.

Urban elders and casino gambling: Are they at risk of a gambling problem?

PubMed

Zaranek, Rochelle R; Lichtenberg, Peter A

2008-01-01

This study examined gambling among older adults and explored the critical predictors of problem gambling behaviors. Relatively unknown and understudied is the extent, or prevalence, of problem gambling behaviors among urban elders and the factors associated with problem gambling. The sample consisted of 1410 randomly selected participants, aged 60 and older, who reside in the City of Detroit. Mental health, health, demographics, social activities, senior optimism, social support network, and frequency of casino visits were examined in order to predict problem gambling behaviors among elders. The survey implemented the Lie/Bet Questionnaire for Screening Probable pathological Gamblers. The results showed that the prevalence of problem gambling behaviors was 10.4% overall, and 18% of persons reporting any casino visitation. Predictors accounted for 16% of problem gambling behaviors. The findings from this study confirmed that gambling has the potential to become a serious health problem among elders. Copyright © 2007 Elsevier Inc. All rights reserved.

Hydric potential of the river basin: Prądnik, Polish Highlands

NASA Astrophysics Data System (ADS)

Lepeška, Tomáš; Radecki-Pawlik, Artur; Wojkowski, Jakub; Walega, Andrzej

2017-12-01

Human society deals with floods, drought and water pollution. Facing those problems, the question how to prevent or at least to minimalize the adverse effects of water-related issues is asked of the landscape managers. In this way, any help given to landscape managers seems to be an additional useful tool. Within this paper, an approach leading to mitigation of water-related problems is presented that relates the retention of precipitation and the use of ecosystems as a tool for improving the quality, quantity of water resources and availability throughout the region. One approach is the determination of the landscape's hydric potential (LHP). This study examines one example of using this method within the conditions of Poland. The results of the research show that national data are entirely appropriate for implementation of the LHP method. Further, this approach revealed the classes of the hydric potential of the Prądnik river basin which was selected as the experimental territory. LHP results reflect the ecosystem attributes of the model river basin; areas of average LHP cover 63.26%, areas of high and limited hydric potential cover approximately 18.3% each. The spatial distribution of LHP means the results of this study provide a baseline for management of the river basin.

Dual stage potential field method for robotic path planning

NASA Astrophysics Data System (ADS)

Singh, Pradyumna Kumar; Parida, Pramod Kumar

2018-04-01

Path planning for autonomous mobile robots are the root for all autonomous mobile systems. Various methods are used for optimization of path to be followed by the autonomous mobile robots. Artificial potential field based path planning method is one of the most used methods for the researchers. Various algorithms have been proposed using the potential field approach. But in most of the common problems are encounters while heading towards the goal or target. i.e. local minima problem, zero potential regions problem, complex shaped obstacles problem, target near obstacle problem. In this paper we provide a new algorithm in which two types of potential functions are used one after another. The former one is to use to get the probable points and later one for getting the optimum path. In this algorithm we consider only the static obstacle and goal.

Working together to solve disparities: Latina/o parents' contributions to the adaptation of a preventive intervention for childhood conduct problems.

PubMed

Niec, Larissa N; Acevedo-Polakovich, Ignacio D; Abbenante-Honold, Emily; Christian, Allison S; Barnett, Miya L; Aguilar, Gerardo; Peer, Samuel O

2014-11-01

Left untreated, conduct problems can have significant and long-lasting negative effects on children's development. Despite the existence of many effective interventions, U.S. Latina/o children are less likely to access or receive evidence-based services. Seeking to build the foundation to address these service disparities, the current study used a Community-Based Participatory Research approach to examine U.S. Latina/o parents' perceptions of the need for interventions to prevent childhood disruptive behaviors in their community in general, and of an existing evidence-based intervention-parent-child interaction therapy (PCIT)-in particular. Results suggest that parents recognize a need for prevention resources in their community and value most of the core features of PCIT. Nevertheless, important directions for potential adaptation and expansion of PCIT into a prevention approach were identified. Results point to several goals for future study with the potential to ameliorate the unmet mental health needs experienced by U.S. Latina/o families with young children at risk for developing conduct problems. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Three-dimensional electrical impedance tomography: a topology optimization approach.

PubMed

Mello, Luís Augusto Motta; de Lima, Cícero Ribeiro; Amato, Marcelo Britto Passos; Lima, Raul Gonzalez; Silva, Emílio Carlos Nelli

2008-02-01

Electrical impedance tomography is a technique to estimate the impedance distribution within a domain, based on measurements on its boundary. In other words, given the mathematical model of the domain, its geometry and boundary conditions, a nonlinear inverse problem of estimating the electric impedance distribution can be solved. Several impedance estimation algorithms have been proposed to solve this problem. In this paper, we present a three-dimensional algorithm, based on the topology optimization method, as an alternative. A sequence of linear programming problems, allowing for constraints, is solved utilizing this method. In each iteration, the finite element method provides the electric potential field within the model of the domain. An electrode model is also proposed (thus, increasing the accuracy of the finite element results). The algorithm is tested using numerically simulated data and also experimental data, and absolute resistivity values are obtained. These results, corresponding to phantoms with two different conductive materials, exhibit relatively well-defined boundaries between them, and show that this is a practical and potentially useful technique to be applied to monitor lung aeration, including the possibility of imaging a pneumothorax.

Direct Multiple Shooting Optimization with Variable Problem Parameters

NASA Technical Reports Server (NTRS)

Whitley, Ryan J.; Ocampo, Cesar A.

2009-01-01

Taking advantage of a novel approach to the design of the orbital transfer optimization problem and advanced non-linear programming algorithms, several optimal transfer trajectories are found for problems with and without known analytic solutions. This method treats the fixed known gravitational constants as optimization variables in order to reduce the need for an advanced initial guess. Complex periodic orbits are targeted with very simple guesses and the ability to find optimal transfers in spite of these bad guesses is successfully demonstrated. Impulsive transfers are considered for orbits in both the 2-body frame as well as the circular restricted three-body problem (CRTBP). The results with this new approach demonstrate the potential for increasing robustness for all types of orbit transfer problems.

Strategies in Forecasting Outcomes in Ethical Decision-making: Identifying and Analyzing the Causes of the Problem

PubMed Central

Beeler, Cheryl K.; Antes, Alison L.; Wang, Xiaoqian; Caughron, Jared J.; Thiel, Chase E.; Mumford, Michael D.

2010-01-01

This study examined the role of key causal analysis strategies in forecasting and ethical decision-making. Undergraduate participants took on the role of the key actor in several ethical problems and were asked to identify and analyze the causes, forecast potential outcomes, and make a decision about each problem. Time pressure and analytic mindset were manipulated while participants worked through these problems. The results indicated that forecast quality was associated with decision ethicality, and the identification of the critical causes of the problem was associated with both higher quality forecasts and higher ethicality of decisions. Neither time pressure nor analytic mindset impacted forecasts or ethicality of decisions. Theoretical and practical implications of these findings are discussed. PMID:20352056

Unfazed or Dazed and Confused: Does Early Adolescent Marijuana Use Cause Sustained Impairments in Attention and Academic Functioning?

PubMed Central

Pardini, Dustin; White, Helene; Xiong, Shuangyan; Bechtold, Jordan; Chung, Tammy; Loeber, Rolf; Hipwell, Alison

2015-01-01

There is some suggestion that heavy marijuana use during early adolescence (prior to age 17) may cause significant impairments in attention and academic functioning that remain following sustained periods of abstinence. However, no longitudinal studies have examined whether both male and female adolescents who engage in low (less than once a month) to moderate (at least once a monthly) marijuana use experience increased problems with attention and academic performance, and whether these problems remain following sustained abstinence. The current study used within-individual change models to control for all potential pre-existing and time-stable confounds when examining this potential causal association in two gender-specific longitudinal samples assessed annually from ages 11 to 16 (Pittsburgh Youth Study N=479; Pittsburgh Girls Study N=2296). Analyses also controlled for the potential influence of several pertinent time-varying factors (e.g., other substance use, peer delinquency). Prior to controlling for time-varying confounds, analyses indicated that adolescents tended to experience an increase in parent-reported attention and academic problems, relative to their pre-onset levels, during years when they used marijuana. After controlling for several time-varying confounds, only the association between marijuana use and attention problems in the sample of girls remained statistically significant. There was no evidence indicating that adolescents who used marijuana experienced lingering attention and academic problems, relative to their pre-onset levels, after abstaining from use for at least a year. These results suggest that adolescents who engage in low to moderate marijuana use experience an increase in observable attention and academic problems, but these problems appear to be minimal and are eliminated following sustained abstinence. PMID:25862212

Effects of adaptive refinement on the inverse EEG solution

NASA Astrophysics Data System (ADS)

Weinstein, David M.; Johnson, Christopher R.; Schmidt, John A.

1995-10-01

One of the fundamental problems in electroencephalography can be characterized by an inverse problem. Given a subset of electrostatic potentials measured on the surface of the scalp and the geometry and conductivity properties within the head, calculate the current vectors and potential fields within the cerebrum. Mathematically the generalized EEG problem can be stated as solving Poisson's equation of electrical conduction for the primary current sources. The resulting problem is mathematically ill-posed i.e., the solution does not depend continuously on the data, such that small errors in the measurement of the voltages on the scalp can yield unbounded errors in the solution, and, for the general treatment of a solution of Poisson's equation, the solution is non-unique. However, if accurate solutions the general treatment of a solution of Poisson's equation, the solution is non-unique. However, if accurate solutions to such problems could be obtained, neurologists would gain noninvasive accesss to patient-specific cortical activity. Access to such data would ultimately increase the number of patients who could be effectively treated for pathological cortical conditions such as temporal lobe epilepsy. In this paper, we present the effects of spatial adaptive refinement on the inverse EEG problem and show that the use of adaptive methods allow for significantly better estimates of electric and potential fileds within the brain through an inverse procedure. To test these methods, we have constructed several finite element head models from magneteic resonance images of a patient. The finite element meshes ranged in size from 2724 nodes and 12,812 elements to 5224 nodes and 29,135 tetrahedral elements, depending on the level of discretization. We show that an adaptive meshing algorithm minimizes the error in the forward problem due to spatial discretization and thus increases the accuracy of the inverse solution.

Unfazed or Dazed and Confused: Does Early Adolescent Marijuana Use Cause Sustained Impairments in Attention and Academic Functioning?

PubMed

Pardini, Dustin; White, Helene R; Xiong, Shuangyan; Bechtold, Jordan; Chung, Tammy; Loeber, Rolf; Hipwell, Alison

2015-10-01

There is some suggestion that heavy marijuana use during early adolescence (prior to age 17) may cause significant impairments in attention and academic functioning that remain despite sustained periods of abstinence. However, no longitudinal studies have examined whether both male and female adolescents who engage in low (less than once a month) to moderate (at least once a monthly) marijuana use experience increased problems with attention and academic performance, and whether these problems remain following sustained abstinence. The current study used within-individual change models to control for all potential pre-existing and time-stable confounds when examining this potential causal association in two gender-specific longitudinal samples assessed annually from ages 11 to 16 (Pittsburgh Youth Study N = 479; Pittsburgh Girls Study N = 2296). Analyses also controlled for the potential influence of several pertinent time-varying factors (e.g., other substance use, peer delinquency). Prior to controlling for time-varying confounds, analyses indicated that adolescents tended to experience an increase in parent-reported attention and academic problems, relative to their pre-onset levels, during years when they used marijuana. After controlling for several time-varying confounds, only the association between marijuana use and attention problems in the sample of girls remained statistically significant. There was no evidence indicating that adolescents who used marijuana experienced lingering attention and academic problems, relative to their pre-onset levels, after abstaining from use for at least a year. These results suggest that adolescents who engage in low to moderate marijuana use experience an increase in observable attention and academic problems, but these problems appear to be minimal and are eliminated following sustained abstinence.

On the Solution of Elliptic Partial Differential Equations on Regions with Corners

DTIC Science & Technology

2015-07-09

In this report we investigate the solution of boundary value problems on polygonal domains for elliptic partial differential equations . We observe...that when the problems are formulated as the boundary integral equations of classical potential theory, the solutions are representable by series of...efficient numerical algorithms. The results are illustrated by a number of numerical examples. On the solution of elliptic partial differential equations on

Cuckoo search via Levy flights applied to uncapacitated facility location problem

NASA Astrophysics Data System (ADS)

Mesa, Armacheska; Castromayor, Kris; Garillos-Manliguez, Cinmayii; Calag, Vicente

2017-11-01

Facility location problem (FLP) is a mathematical way to optimally locate facilities within a set of candidates to satisfy the requirements of a given set of clients. This study addressed the uncapacitated FLP as it assures that the capacity of every selected facility is finite. Thus, even if the demand is not known, which often is the case, in reality, organizations may still be able to take strategic decisions such as locating the facilities. There are different approaches relevant to the uncapacitated FLP. Here, the cuckoo search via Lévy flight (CS-LF) was used to solve the problem. Though hybrid methods produce better results, this study employed CS-LF to determine first its potential in finding solutions for the problem, particularly when applied to a real-world problem. The method was applied to the data set obtained from a department store in Davao City, Philippines. Results showed that applying CS-LF yielded better facility locations compared to particle swarm optimization and other existing algorithms. Although these results showed that CS-LF is a promising method to solve this particular problem, further studies on other FLP are recommended to establish a strong foundation of the capability of CS-LF in solving FLP.

Ethical Concerns of and Risk Mitigation Strategies for Crowdsourcing Contests and Innovation Challenges: Scoping Review

PubMed Central

Pan, Stephen W; Mathews, Allison; Stein, Gabriella; Bayus, Barry; Rennie, Stuart

2018-01-01

Background Crowdsourcing contests (also called innovation challenges, innovation contests, and inducement prize contests) can be used to solicit multisectoral feedback on health programs and design public health campaigns. They consist of organizing a steering committee, soliciting contributions, engaging the community, judging contributions, recognizing a subset of contributors, and sharing with the community. Objective This scoping review describes crowdsourcing contests by stage, examines ethical problems at each stage, and proposes potential ways of mitigating risk. Methods Our analysis was anchored in the specific example of a crowdsourcing contest that our team organized to solicit videos promoting condom use in China. The purpose of this contest was to create compelling 1-min videos to promote condom use. We used a scoping review to examine the existing ethical literature on crowdsourcing to help identify and frame ethical concerns at each stage. Results Crowdsourcing has a group of individuals solve a problem and then share the solution with the public. Crowdsourcing contests provide an opportunity for community engagement at each stage: organizing, soliciting, promoting, judging, recognizing, and sharing. Crowdsourcing poses several ethical concerns: organizing—potential for excluding community voices; soliciting—potential for overly narrow participation; promoting—potential for divulging confidential information; judging—potential for biased evaluation; recognizing—potential for insufficient recognition of the finalist; and sharing—potential for the solution to not be implemented or widely disseminated. Conclusions Crowdsourcing contests can be effective and engaging public health tools but also introduce potential ethical problems. We present methods for the responsible conduct of crowdsourcing contests. PMID:29523500

Recasting Problems as Potentials in Group Work

ERIC Educational Resources Information Center

Laursen, Erik K.; Oliver, Vernon

2003-01-01

Problem-solving groups can become preoccupied with deficit and deviance, while overlooking potential and resources. This article describes methods for using problems as an entree into the development of strengths and solutions. (Contains 1 table.)

The dynamics of learning about a climate threshold

NASA Astrophysics Data System (ADS)

Keller, Klaus; McInerney, David

2008-02-01

Anthropogenic greenhouse gas emissions may trigger threshold responses of the climate system. One relevant example of such a potential threshold response is a shutdown of the North Atlantic meridional overturning circulation (MOC). Numerous studies have analyzed the problem of early MOC change detection (i.e., detection before the forcing has committed the system to a threshold response). Here we analyze the early MOC prediction problem. To this end, we virtually deploy an MOC observation system into a simple model that mimics potential future MOC responses and analyze the timing of confident detection and prediction. Our analysis suggests that a confident prediction of a potential threshold response can require century time scales, considerably longer that the time required for confident detection. The signal enabling early prediction of an approaching MOC threshold in our model study is associated with the rate at which the MOC intensity decreases for a given forcing. A faster MOC weakening implies a higher MOC sensitivity to forcing. An MOC sensitivity exceeding a critical level results in a threshold response. Determining whether an observed MOC trend in our model differs in a statistically significant way from an unforced scenario (the detection problem) imposes lower requirements on an observation system than the determination whether the MOC will shut down in the future (the prediction problem). As a result, the virtual observation systems designed in our model for early detection of MOC changes might well fail at the task of early and confident prediction. Transferring this conclusion to the real world requires a considerably refined MOC model, as well as a more complete consideration of relevant observational constraints.

The Fundamental Flaws of Immunoassays and Potential Solutions Using Tandem Mass Spectrometry

PubMed Central

Hoofnagle, Andrew N.; Wener, Mark H.

2009-01-01

Immunoassays have made it possible to measure dozens of individual proteins and other analytes in human samples for help in establishing the diagnosis and prognosis of disease. In too many cases the results of those measurements are misleading and can lead to unnecessary treatment or missed opportunities for therapeutic interventions. These cases stem from problems inherent to immunoassays performed with human samples, which include a lack of concordance across platforms, autoantibodies, anti-reagent antibodies, and the high-dose hook effect. Tandem mass spectrometry may represent a detection method capable of alleviating many of the flaws inherent to immunoassays. We review our understanding of the problems associated with immunoassays on human specimens and describe methodologies using tandem mass spectrometry that could solve some of those problems. We also provide a critical discussion of the potential pitfalls of novel mass spectrometric approaches in the clinical laboratory. PMID:19538965

Job Scheduling in a Heterogeneous Grid Environment

NASA Technical Reports Server (NTRS)

Shan, Hong-Zhang; Smith, Warren; Oliker, Leonid; Biswas, Rupak

2004-01-01

Computational grids have the potential for solving large-scale scientific problems using heterogeneous and geographically distributed resources. However, a number of major technical hurdles must be overcome before this potential can be realized. One problem that is critical to effective utilization of computational grids is the efficient scheduling of jobs. This work addresses this problem by describing and evaluating a grid scheduling architecture and three job migration algorithms. The architecture is scalable and does not assume control of local site resources. The job migration policies use the availability and performance of computer systems, the network bandwidth available between systems, and the volume of input and output data associated with each job. An extensive performance comparison is presented using real workloads from leading computational centers. The results, based on several key metrics, demonstrate that the performance of our distributed migration algorithms is significantly greater than that of a local scheduling framework and comparable to a non-scalable global scheduling approach.

Analysis of Failures of High Speed Shaft Bearing System in a Wind Turbine

NASA Astrophysics Data System (ADS)

Wasilczuk, Michał; Gawarkiewicz, Rafał; Bastian, Bartosz

2018-01-01

During the operation of wind turbines with gearbox of traditional configuration, consisting of one planetary stage and two helical stages high failure rate of high speed shaft bearings is observed. Such a high failures frequency is not reflected in the results of standard calculations of bearing durability. Most probably it can be attributed to atypical failure mechanism. The authors studied problems in 1.5 MW wind turbines of one of Polish wind farms. The analysis showed that the problems of high failure rate are commonly met all over the world and that the statistics for the analysed turbines were very similar. After the study of potential failure mechanism and its potential reasons, modification of the existing bearing system was proposed. Various options, with different bearing types were investigated. Different versions were examined for: expected durability increase, extent of necessary gearbox modifications and possibility to solve existing problems in operation.

Solution of monotone complementarity and general convex programming problems using a modified potential reduction interior point method

DOE PAGES

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

Optimal partial mass transportation and obstacle Monge-Kantorovich equation

NASA Astrophysics Data System (ADS)

Igbida, Noureddine; Nguyen, Van Thanh

2018-05-01

Optimal partial mass transport, which is a variant of the optimal transport problem, consists in transporting effectively a prescribed amount of mass from a source to a target. The problem was first studied by Caffarelli and McCann (2010) [6] and Figalli (2010) [12] with a particular attention to the quadratic cost. Our aim here is to study the optimal partial mass transport problem with Finsler distance costs including the Monge cost given by the Euclidian distance. Our approach is different and our results do not follow from previous works. Among our results, we introduce a PDE of Monge-Kantorovich type with a double obstacle to characterize active submeasures, Kantorovich potential and optimal flow for the optimal partial transport problem. This new PDE enables us to study the uniqueness and monotonicity results for the active submeasures. Another interesting issue of our approach is its convenience for numerical analysis and computations that we develop in a separate paper [14] (Igbida and Nguyen, 2018).

A bounding-based solution approach for the continuous arc covering problem

NASA Astrophysics Data System (ADS)

Wei, Ran; Murray, Alan T.; Batta, Rajan

2014-04-01

Road segments, telecommunication wiring, water and sewer pipelines, canals and the like are important features of the urban environment. They are often conceived of and represented as network-based arcs. As a result of the usefulness and significance of arc-based features, there is a need to site facilities along arcs to serve demand. Examples of such facilities include surveillance equipment, cellular towers, refueling centers and emergency response stations, with the intent of being economically efficient as well as providing good service along the arcs. While this amounts to a continuous location problem by nature, various discretizations are generally relied upon to solve such problems. The result is potential for representation errors that negatively impact analysis and decision making. This paper develops a solution approach for the continuous arc covering problem that theoretically eliminates representation errors. The developed approach is applied to optimally place acoustic sensors and cellular base stations along a road network. The results demonstrate the effectiveness of this approach for ameliorating any error and uncertainty in the modeling process.

Life Outside the Golden Window: Statistical Angles on the Signal-to-Noise Problem

NASA Astrophysics Data System (ADS)

Wagman, Michael

2018-03-01

Lattice QCD simulations of multi-baryon correlation functions can predict the structure and reactions of nuclei without encountering the baryon chemical potential sign problem. However, they suffer from a signal-to-noise problem where Monte Carlo estimates of observables have quantum fluctuations that are exponentially larger than their average values. Recent lattice QCD results demonstrate that the complex phase of baryon correlations functions relates the baryon signal-to-noise problem to a sign problem and exhibits unexpected statistical behavior resembling a heavy-tailed random walk on the unit circle. Estimators based on differences of correlation function phases evaluated at different Euclidean times are discussed that avoid the usual signal-to-noise problem, instead facing a signal-to-noise problem as the time interval associated with the phase difference is increased, and allow hadronic observables to be determined from arbitrarily large-time correlation functions.

An Improved Zero Potential Circuit for Readout of a Two-Dimensional Resistive Sensor Array

PubMed Central

Wu, Jian-Feng; Wang, Feng; Wang, Qi; Li, Jian-Qing; Song, Ai-Guo

2016-01-01

With one operational amplifier (op-amp) in negative feedback, the traditional zero potential circuit could access one element in the two-dimensional (2-D) resistive sensor array with the shared row-column fashion but it suffered from the crosstalk problem for the non-scanned elements’ bypass currents, which were injected into array’s non-scanned electrodes from zero potential. Firstly, for suppressing the crosstalk problem, we designed a novel improved zero potential circuit with one more op-amp in negative feedback to sample the total bypass current and calculate the precision resistance of the element being tested (EBT) with it. The improved setting non-scanned-electrode zero potential circuit (S-NSE-ZPC) was given as an example for analyzing and verifying the performance of the improved zero potential circuit. Secondly, in the S-NSE-ZPC and the improved S-NSE-ZPC, the effects of different parameters of the resistive sensor arrays and their readout circuits on the EBT’s measurement accuracy were simulated with the NI Multisim 12. Thirdly, part features of the improved circuit were verified with the experiments of a prototype circuit. Followed, the results were discussed and the conclusions were given. The experiment results show that the improved circuit, though it requires one more op-amp, one more resistor and one more sampling channel, can access the EBT in the 2-D resistive sensor array more accurately. PMID:27929410

An Improved Zero Potential Circuit for Readout of a Two-Dimensional Resistive Sensor Array.

PubMed

Wu, Jian-Feng; Wang, Feng; Wang, Qi; Li, Jian-Qing; Song, Ai-Guo

2016-12-06

With one operational amplifier (op-amp) in negative feedback, the traditional zero potential circuit could access one element in the two-dimensional (2-D) resistive sensor array with the shared row-column fashion but it suffered from the crosstalk problem for the non-scanned elements' bypass currents, which were injected into array's non-scanned electrodes from zero potential. Firstly, for suppressing the crosstalk problem, we designed a novel improved zero potential circuit with one more op-amp in negative feedback to sample the total bypass current and calculate the precision resistance of the element being tested (EBT) with it. The improved setting non-scanned-electrode zero potential circuit (S-NSE-ZPC) was given as an example for analyzing and verifying the performance of the improved zero potential circuit. Secondly, in the S-NSE-ZPC and the improved S-NSE-ZPC, the effects of different parameters of the resistive sensor arrays and their readout circuits on the EBT's measurement accuracy were simulated with the NI Multisim 12. Thirdly, part features of the improved circuit were verified with the experiments of a prototype circuit. Followed, the results were discussed and the conclusions were given. The experiment results show that the improved circuit, though it requires one more op-amp, one more resistor and one more sampling channel, can access the EBT in the 2-D resistive sensor array more accurately.

Mindfulness Facets, Social Anxiety, and Drinking to Cope with Social Anxiety: Testing Mediators of Drinking Problems

PubMed Central

Clerkin, Elise M.; Sarfan, Laurel D.; Parsons, E. Marie; Magee, Joshua C.

2016-01-01

This cross-sectional study tested social anxiety symptoms, trait mindfulness, and drinking to cope with social anxiety as potential predictors and/or serial mediators of drinking problems. A community-based sample of individuals with co-occurring social anxiety symptoms and alcohol dependence were recruited. Participants (N = 105) completed measures of social anxiety, drinking to cope with social anxiety, and alcohol use and problems. As well, participants completed the Five Facet Mindfulness Questionnaire, which assesses mindfulness facets of accepting without judgment, acting with awareness, not reacting to one’s internal experiences, observing and attending to experiences, and labeling and describing. As predicted, the relationship between social anxiety symptoms and drinking problems was mediated by social anxiety coping motives across each of the models. Further, the relationship between specific mindfulness facets (acting with awareness, accepting without judgment, and describe) and drinking problems was serially mediated by social anxiety symptoms and drinking to cope with social anxiety. This research builds upon existing studies that have largely been conducted with college students to evaluate potential mediators driving drinking problems. Specifically, individuals who are less able to act with awareness, accept without judgment, and describe their internal experiences may experience heightened social anxiety and drinking to cope with that anxiety, which could ultimately result in greater alcohol-related problems. PMID:28392844

Linearized potential solution for an airfoil in nonuniform parallel streams

NASA Technical Reports Server (NTRS)

Prabhu, R. K.; Tiwari, S. N.

1983-01-01

A small perturbation potential flow theory is applied to the problem of determining the chordwise pressure distribution, lift and pitching moment of a thin airfoil in the middle of five parallel streams. This theory is then extended to the case of an undisturbed stream having a given smooth velocity profile. Two typical examples are considered and the results obtained are compared with available solutions of Euler's equations. The agreement between these two results is not quite satisfactory. Possible reasons for the differences are indicated.

Development of drilling foams for geothermal applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonald, W.J.; Remont, L.J.; Rehm, W.A.

The use of foam drilling fluids in geothermal applications is addressed. A description of foams - what they are, how they are used, their properties, equipment required to use them, the advantages and disadvantages of foams, etc. - is presented. Geothermal applications are discussed. Results of industry interviews presented indicate significant potential for foams, but also indicate significant technical problems to be solved to achieve this potential. Testing procedures and results of tests on representative foams provide a basis for work to develop high-temperature foams.

Vibration and bending analyses of magneto-electro-thermo-elastic sandwich microplates resting on viscoelastic foundation

NASA Astrophysics Data System (ADS)

Arefi, Mohammad; Zenkour, Ashraf M.

2017-08-01

Magneto-electro-thermo-mechanical bending and free vibration analysis of a sandwich microplate using strain gradient theory is expressed in this paper. The sandwich plate is made of a core and two integrated piezo-magnetic face sheets. The structure is subjected to electric and magnetic potentials, thermal loadings, and resting on Pasternak's foundation. Electro-magnetic equations are developed by considering the variation form of Hamilton's principle. The effects of important parameters of this problem such as applied electric and magnetic potentials, direct and shear parameter of foundation, three microlength-scale parameters, and two parameters of temperature rising are investigated on the vibration and bending results of problem.

Aircraft engine sump-fire studies

NASA Technical Reports Server (NTRS)

Loomis, W. R.

1976-01-01

Results of ongoing experimental studies are reported in which a 125-millimeter-diameter-advanced-bearing test rig simulating an engine sump is being used to find the critical range of conditions for fires to occur. Design, material, and operating concepts and techniques are being studied with the objective of minimizing the problem. It has been found that the vapor temperature near a spark ignitor is most important in determining ignition potential. At temperatures producing oil vapor pressures below or much above the calculated flammability limits, fires have not been ignited. But fires have been routinely started within the theoretical flammability range. This indicates that generalizing the sump-fire problem may make it amenable to analysis, with the potential for realistic solutions.

Linear frictional forces cause orbits to neither circularize nor precess

NASA Astrophysics Data System (ADS)

Hamilton, B.; Crescimanno, M.

2008-06-01

For the undamped Kepler potential the lack of precession has historically been understood in terms of the Runge-Lenz symmetry. For the damped Kepler problem this result may be understood in terms of the generalization of Poisson structure to damped systems suggested recently by Tarasov (2005 J. Phys. A: Math. Gen. 38 2145). In this generalized algebraic structure the orbit-averaged Runge-Lenz vector remains a constant in the linearly damped Kepler problem to leading order in the damping coefficient. Beyond Kepler, we prove that, for any potential proportional to a power of the radius, the orbit shape and precession angle remain constant to leading order in the linear friction coefficient.

Studies on the interference of wings and propeller slipstreams

NASA Technical Reports Server (NTRS)

Prabhu, R. K.; Tiwari, S. N.

1985-01-01

The small disturbance potential flow theory is applied to determine the lift of an airfoil in a nonuniform parallel stream. The given stream is replaced by an equivalent stream with a certain number of velocity discontinuities, and the influence of these discontinuities is obtained by the method of images. Next, this method is extended to the problem of an airfoil in a nonuniform stream of smooth velocity profile. This model allows perturbation velocity potential in a rotational undisturbed stream. A comparison of these results with numerical solutions of Euler equations indicates that, although approximate, the present method provides useful information about the interaction problem while avoiding the need to solve the Euler equations.

Managing wilderness recreation use: common problems and potential solutions

Treesearch

David N. Cole; Margaret E. Petersen; Robert C. Lucas

1987-01-01

Describes pros and cons of potential solutions to common wilderness recreation problems. Covers the purpose of each potential solution, costs to visitors and management, effectiveness, other considerations, and sources of additional information.

On Born's Conjecture about Optimal Distribution of Charges for an Infinite Ionic Crystal

NASA Astrophysics Data System (ADS)

Bétermin, Laurent; Knüpfer, Hans

2018-04-01

We study the problem for the optimal charge distribution on the sites of a fixed Bravais lattice. In particular, we prove Born's conjecture about the optimality of the rock salt alternate distribution of charges on a cubic lattice (and more generally on a d-dimensional orthorhombic lattice). Furthermore, we study this problem on the two-dimensional triangular lattice and we prove the optimality of a two-component honeycomb distribution of charges. The results hold for a class of completely monotone interaction potentials which includes Coulomb-type interactions for d≥3 . In a more general setting, we derive a connection between the optimal charge problem and a minimization problem for the translated lattice theta function.

Violence exposure as a predictor of internalizing and externalizing problems among children of substance abusers.

PubMed

Conners-Burrow, Nicola; McKelvey, Lorraine; Kyzer, Angela; Swindle, Taren; Cheerla, Rajalakshmi; Kraleti, Shashank

2013-01-01

We explore the associations between exposure to conflict and crime in the home and community, and child anxiety and self-control problems among 60 children whose mothers were in treatment for substance abuse problems. Experiences with violence and crime were widespread, with many children exposed to multiple incidents. Approximately one-third (35.5%) of children exhibited clinically elevated anxiety. Controlling for other potential predictors, both children's exposure to violence and the number of years the mother had been using substances predicted higher anxiety in children, while only exposure to violence predicted problems in self-control. Results highlight the importance of screening for violence exposure. Copyright © 2013 Elsevier Inc. All rights reserved.

Optimizing Restriction Site Placement for Synthetic Genomes

NASA Astrophysics Data System (ADS)

Montes, Pablo; Memelli, Heraldo; Ward, Charles; Kim, Joondong; Mitchell, Joseph S. B.; Skiena, Steven

Restriction enzymes are the workhorses of molecular biology. We introduce a new problem that arises in the course of our project to design virus variants to serve as potential vaccines: we wish to modify virus-length genomes to introduce large numbers of unique restriction enzyme recognition sites while preserving wild-type function by substitution of synonymous codons. We show that the resulting problem is NP-Complete, give an exponential-time algorithm, and propose effective heuristics, which we show give excellent results for five sample viral genomes. Our resulting modified genomes have several times more unique restriction sites and reduce the maximum gap between adjacent sites by three to nine-fold.

Evaluation of the HARDMAN comparability methodology for manpower, personnel and training

NASA Technical Reports Server (NTRS)

Zimmerman, W.; Butler, R.; Gray, V.; Rosenberg, L.

1984-01-01

The methodology evaluation and recommendation are part of an effort to improve Hardware versus Manpower (HARDMAN) methodology for projecting manpower, personnel, and training (MPT) to support new acquisition. Several different validity tests are employed to evaluate the methodology. The methodology conforms fairly well with both the MPT user needs and other accepted manpower modeling techniques. Audits of three completed HARDMAN applications reveal only a small number of potential problem areas compared to the total number of issues investigated. The reliability study results conform well with the problem areas uncovered through the audits. The results of the accuracy studies suggest that the manpower life-cycle cost component is only marginally sensitive to changes in other related cost variables. Even with some minor problems, the methodology seem sound and has good near term utility to the Army. Recommendations are provided to firm up the problem areas revealed through the evaluation.

Stress and prevalence of hearing problems in the Swedish working population

PubMed Central

2011-01-01

Background Current human and experimental studies are indicating an association between stress and hearing problems; however potential risk factors have not been established. Hearing problems are projected to become among the top ten disabilities according to the WHO in the near future. Therefore a better understanding of the relationships between stress and hearing is warranted. Here we describe the prevalence of two common hearing problems, i.e. hearing complaints and tinnitus, in relation to different work-and health-related stressors. Methods A total of 18,734 individuals were invited to participate in the study, out of which 9,756 (52%) enrolled. Results The results demonstrate a clear and mostly linear relationship between higher prevalence of hearing problems (tinnitus or hearing loss or both) and different stressors, e.g. occupational, poorer self-rated health, long-term illness, poorer sleep quality, and higher burnout scores. Conclusions The present study unambiguously demonstrates associations between hearing problems and various stressors that have not been previously described for the auditory system. These findings will open new avenues for future investigations. PMID:21345187

An Application of the Difference Potentials Method to Solving External Problems in CFD

NASA Technical Reports Server (NTRS)

Ryaben 'Kii, Victor S.; Tsynkov, Semyon V.

1997-01-01

Numerical solution of infinite-domain boundary-value problems requires some special techniques that would make the problem available for treatment on the computer. Indeed, the problem must be discretized in a way that the computer operates with only finite amount of information. Therefore, the original infinite-domain formulation must be altered and/or augmented so that on one hand the solution is not changed (or changed slightly) and on the other hand the finite discrete formulation becomes available. One widely used approach to constructing such discretizations consists of truncating the unbounded original domain and then setting the artificial boundary conditions (ABC's) at the newly formed external boundary. The role of the ABC's is to close the truncated problem and at the same time to ensure that the solution found inside the finite computational domain would be maximally close to (in the ideal case, exactly the same as) the corresponding fragment of the original infinite-domain solution. Let us emphasize that the proper treatment of artificial boundaries may have a profound impact on the overall quality and performance of numerical algorithms. The latter statement is corroborated by the numerous computational experiments and especially concerns the area of CFD, in which external problems present a wide class of practically important formulations. In this paper, we review some work that has been done over the recent years on constructing highly accurate nonlocal ABC's for calculation of compressible external flows. The approach is based on implementation of the generalized potentials and pseudodifferential boundary projection operators analogous to those proposed first by Calderon. The difference potentials method (DPM) by Ryaben'kii is used for the effective computation of the generalized potentials and projections. The resulting ABC's clearly outperform the existing methods from the standpoints of accuracy and robustness, in many cases noticeably speed up the multigrid convergence, and at the same time are quite comparable to other methods from the standpoints of geometric universality and simplicity of implementation.

Dynamic least-squares kernel density modeling of Fokker-Planck equations with application to neural population.

PubMed

Shotorban, Babak

2010-04-01

The dynamic least-squares kernel density (LSQKD) model [C. Pantano and B. Shotorban, Phys. Rev. E 76, 066705 (2007)] is used to solve the Fokker-Planck equations. In this model the probability density function (PDF) is approximated by a linear combination of basis functions with unknown parameters whose governing equations are determined by a global least-squares approximation of the PDF in the phase space. In this work basis functions are set to be Gaussian for which the mean, variance, and covariances are governed by a set of partial differential equations (PDEs) or ordinary differential equations (ODEs) depending on what phase-space variables are approximated by Gaussian functions. Three sample problems of univariate double-well potential, bivariate bistable neurodynamical system [G. Deco and D. Martí, Phys. Rev. E 75, 031913 (2007)], and bivariate Brownian particles in a nonuniform gas are studied. The LSQKD is verified for these problems as its results are compared against the results of the method of characteristics in nondiffusive cases and the stochastic particle method in diffusive cases. For the double-well potential problem it is observed that for low to moderate diffusivity the dynamic LSQKD well predicts the stationary PDF for which there is an exact solution. A similar observation is made for the bistable neurodynamical system. In both these problems least-squares approximation is made on all phase-space variables resulting in a set of ODEs with time as the independent variable for the Gaussian function parameters. In the problem of Brownian particles in a nonuniform gas, this approximation is made only for the particle velocity variable leading to a set of PDEs with time and particle position as independent variables. Solving these PDEs, a very good performance by LSQKD is observed for a wide range of diffusivities.

Creating Impact with Operations Research in Health: Making Room for Practice in Academia

PubMed Central

Brandeau, Margaret L.

2015-01-01

Operations research (OR)-based analyses have the potential to improve decision making for many important, real-world health care problems. However, junior scholars often avoid working on practical applications in health because promotion and tenure processes tend to value theoretical studies more highly than applied studies. This paper discusses the author's experiences in using OR to inform and influence decisions in health and provides a blueprint for junior researchers who wish to find success by taking a similar path. This involves selecting good problems to study, forming productive collaborations with domain experts, developing appropriate models, identifying the most salient results from an analysis, and effectively disseminating findings to decision makers. The paper then suggests how journals, funding agencies, and senior academics can encourage such work by taking a broader and more informed view of the potential role and contributions of OR to solving health care problems. Making room in academia for the application of OR in health follows in the tradition begun by the founders of operations research: to work on important real-world problems where operations research can contribute to better decision making. PMID:26003321

Does poor school performance cause later psychosocial problems among children in foster care? Evidence from national longitudinal registry data.

PubMed

Forsman, Hilma; Brännström, Lars; Vinnerljung, Bo; Hjern, Anders

2016-07-01

Research has shown that children in foster care are a high-risk group for adverse economic, social and health related outcomes in young adulthood. Children's poor school performance has been identified as a major risk factor for these poor later life outcomes. Aiming to support the design of effective intervention strategies, this study examines the hypothesized causal effect of foster children's poor school performance on subsequent psychosocial problems, here conceptualized as economic hardship, illicit drug use, and mental health problems, in young adulthood. Using the potential outcomes approach, longitudinal register data on more than 7500 Swedish foster children born 1973-1978 were analyzed by means of doubly robust treatment-effect estimators. The results show that poor school performance has a negative impact on later psychosocial problems net of observed background attributes and potential selection on unobservables, suggesting that the estimated effects allow for causal interpretations. Promotion of school performance may thus be a viable intervention path for policymakers and practitioners interested in improving foster children's overall life chances. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ayurvedic Medicine

MedlinePlus

... had problems with research designs, or lacked appropriate control groups, potentially affecting research results. Researchers have studied Ayurvedic approaches for schizophrenia and for diabetes; however, scientific evidence for its effectiveness for these ... for Disease Control and Prevention. Lead poisoning in pregnant women who ...

Ship Superstructure Icing: Crystalline And Physical Properties

DOT National Transportation Integrated Search

2000-08-01

Ice grows on ship superstructure components as a result of precipitation of saline spray from the ocean surface in winter seas. A potentially serious problem, superstructure icing reduces ship sea-keeping ability and hinders deck operations. In Febru...

A position-dependent mass model for the Thomas–Fermi potential: Exact solvability and relation to δ-doped semiconductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schulze-Halberg, Axel, E-mail: xbataxel@gmail.com; García-Ravelo, Jesús; Pacheco-García, Christian

We consider the Schrödinger equation in the Thomas–Fermi field, a model that has been used for describing electron systems in δ-doped semiconductors. It is shown that the problem becomes exactly-solvable if a particular effective (position-dependent) mass distribution is incorporated. Orthogonal sets of normalizable bound state solutions are constructed in explicit form, and the associated energies are determined. We compare our results with the corresponding findings on the constant-mass problem discussed by Ioriatti (1990) [13]. -- Highlights: ► We introduce an exactly solvable, position-dependent mass model for the Thomas–Fermi potential. ► Orthogonal sets of solutions to our model are constructed inmore » closed form. ► Relation to delta-doped semiconductors is discussed. ► Explicit subband bottom energies are calculated and compared to results obtained in a previous study.« less

A Comparison of Descriptive and Functional Analyses of Inappropriate Mealtime Behavior.

PubMed

Borrero, Carrie S W; England, Jennie D; Sarcia, Ben; Woods, Julia N

2016-12-01

In recent years, rather than being used to assess the potential function of a response, descriptive assessment methods have been applied to evaluate potential consequences or contingencies for problem behavior (Borrero, Woods, Borrero, Masler, & Lesser in Journal of Applied Behavior Analysis, 43 , 71-88. doi: 10.1901/jaba.2010.43-71, 2010) or to assist with designing baseline conditions to approximate caregiver behavior (Casey et al. in Behavior Modification, 33 , 537-558. doi: 10.1177/0145445509341457, 2009). It has been shown that descriptive assessments of some forms of problem behavior (e.g., self-injury, aggression) are not good indicators of behavioral function and should not be used exclusively when conducting functional behavior assessments (Thompson & Iwata in Journal of Applied Behavior Analysis, 40 , 333-338. doi: 10.1901/jaba.2007.56.06/epdf, 2007). However, the extent to which descriptive assessments of inappropriate mealtime behavior can predict behavioral function is not yet clear. We conducted descriptive assessments of inappropriate mealtime behavior and compared the results to functional analyses for ten children with severe food refusal. Results showed that, for 71 % of participants, the descriptive and functional analyses matched. These results suggest that the correspondence between descriptive and functional analyses, at least for inappropriate mealtime behavior, may be higher than that for other forms of problem behavior.

Using Eye Trackers for Usability Evaluation of Health Information Technology: A Systematic Literature Review

PubMed Central

Yang, Yushi

2015-01-01

Background Eye-tracking technology has been used to measure human cognitive processes and has the potential to improve the usability of health information technology (HIT). However, it is still unclear how the eye-tracking method can be integrated with other traditional usability methodologies to achieve its full potential. Objective The objective of this study was to report on HIT evaluation studies that have used eye-tracker technology, and to envision the potential use of eye-tracking technology in future research. Methods We used four reference databases to initially identify 5248 related papers, which resulted in only 9 articles that met our inclusion criteria. Results Eye-tracking technology was useful in finding usability problems in many ways, but is still in its infancy for HIT usability evaluation. Limited types of HITs have been evaluated by eye trackers, and there has been a lack of evaluation research in natural settings. Conclusions More research should be done in natural settings to discover the real contextual-based usability problems of clinical and mobile HITs using eye-tracking technology with more standardized methodologies and guidance. PMID:27026079

Boundary elements; Proceedings of the Fifth International Conference, Hiroshima, Japan, November 8-11, 1983

NASA Astrophysics Data System (ADS)

Brebbia, C. A.; Futagami, T.; Tanaka, M.

The boundary-element method (BEM) in computational fluid and solid mechanics is examined in reviews and reports of theoretical studies and practical applications. Topics presented include the fundamental mathematical principles of BEMs, potential problems, EM-field problems, heat transfer, potential-wave problems, fluid flow, elasticity problems, fracture mechanics, plates and shells, inelastic problems, geomechanics, dynamics, industrial applications of BEMs, optimization methods based on the BEM, numerical techniques, and coupling.

Improved detection of overrepresentation of Gene-Ontology annotations with parent child analysis.

PubMed

Grossmann, Steffen; Bauer, Sebastian; Robinson, Peter N; Vingron, Martin

2007-11-15

High-throughput experiments such as microarray hybridizations often yield long lists of genes found to share a certain characteristic such as differential expression. Exploring Gene Ontology (GO) annotations for such lists of genes has become a widespread practice to get first insights into the potential biological meaning of the experiment. The standard statistical approach to measuring overrepresentation of GO terms cannot cope with the dependencies resulting from the structure of GO because they analyze each term in isolation. Especially the fact that annotations are inherited from more specific descendant terms can result in certain types of false-positive results with potentially misleading biological interpretation, a phenomenon which we term the inheritance problem. We present here a novel approach to analysis of GO term overrepresentation that determines overrepresentation of terms in the context of annotations to the term's parents. This approach reduces the dependencies between the individual term's measurements, and thereby avoids producing false-positive results owing to the inheritance problem. ROC analysis using study sets with overrepresented GO terms showed a clear advantage for our approach over the standard algorithm with respect to the inheritance problem. Although there can be no gold standard for exploratory methods such as analysis of GO term overrepresentation, analysis of biological datasets suggests that our algorithm tends to identify the core GO terms that are most characteristic of the dataset being analyzed.

The analytical transfer matrix method for PT-symmetric complex potential

NASA Astrophysics Data System (ADS)

Naceri, Leila; Hammou, Amine B.

2017-07-01

We have extended the analytical transfer matrix (ATM) method to solve quantum mechanical bound state problems with complex PT-symmetric potentials. Our work focuses on a class of models studied by Bender and Jones, we calculate the energy eigenvalues, discuss the critical values of g and compare the results with those obtained from other methods such as exact numerical computation and WKB approximation method.

O (6 ) algebraic theory of three nonrelativistic quarks bound by spin-independent interactions

NASA Astrophysics Data System (ADS)

Dmitrašinović, V.; Salom, Igor

2018-05-01

We apply the newly developed theory of permutation-symmetric O (6 ) hyperspherical harmonics to the quantum-mechanical problem of three nonrelativistic quarks confined by a spin-independent three-quark potential. We use our previously derived results to reduce the three-body Schrödinger equation to a set of coupled ordinary differential equations in the hyper-radius R with coupling coefficients expressed entirely in terms of (i) a few interaction-dependent O (6 ) expansion coefficients and (ii) O (6 ) hyperspherical harmonics matrix elements that have been evaluated in our previous paper. This system of equations allows a solution to the eigenvalue problem with homogeneous three-quark potentials, the class of which includes a number of standard Ansätze for the confining potentials, such as the Y- and Δ -string ones. We present analytic formulas for the K =2 , 3, 4, 5 shell states' eigenenergies in homogeneous three-body potentials, which we then apply to the Y and Δ strings as well as the logarithmic confining potentials. We also present numerical results for power-law pairwise potentials with the exponent ranging between -1 and +2 . In the process, we resolve the 25-year-old Taxil and Richard vs Bowler et al. controversy regarding the ordering of states in the K =3 shell, in favor of the former. Finally, we show the first clear difference between the spectra of Δ - and Y-string potentials, which appears in K ≥3 shells. Our results are generally valid, not just for confining potentials but also for many momentum-independent permutation-symmetric homogenous potentials that need not be pairwise sums of two-body terms. The potentials that can be treated in this way must be square integrable under the O (6 ) hyperangular integral, the class of which, however, does not include the Dirac δ function.

On the parallel solution of parabolic equations

NASA Technical Reports Server (NTRS)

Gallopoulos, E.; Saad, Youcef

1989-01-01

Parallel algorithms for the solution of linear parabolic problems are proposed. The first of these methods is based on using polynomial approximation to the exponential. It does not require solving any linear systems and is highly parallelizable. The two other methods proposed are based on Pade and Chebyshev approximations to the matrix exponential. The parallelization of these methods is achieved by using partial fraction decomposition techniques to solve the resulting systems and thus offers the potential for increased time parallelism in time dependent problems. Experimental results from the Alliant FX/8 and the Cray Y-MP/832 vector multiprocessors are also presented.

Rockets for spin recovery

NASA Technical Reports Server (NTRS)

Whipple, R. D.

1980-01-01

The potential effectiveness of rockets as an auxiliary means for an aircraft to effect recovery from spins was investigated. The advances in rocket technology produced by the space effort suggested that currently available systems might obviate many of the problems encountered in earlier rocket systems. A modern fighter configuration known to exhibit a flat spin mode was selected. An analytical study was made of the thrust requirements for a rocket spin recovery system for the subject configuration. These results were then applied to a preliminary systems study of rocket components appropriate to the problem. Subsequent spin tunnel tests were run to evaluate the analytical results.

Dual simulation of the massless lattice Schwinger model with topological term and non-zero chemical potential

NASA Astrophysics Data System (ADS)

Göschl, Daniel

2018-03-01

We discuss simulation strategies for the massless lattice Schwinger model with a topological term and finite chemical potential. The simulation is done in a dual representation where the complex action problem is solved and the partition function is a sum over fermion loops, fermion dimers and plaquette-occupation numbers. We explore strategies to update the fermion loops coupled to the gauge degrees of freedom and check our results with conventional simulations (without topological term and at zero chemical potential), as well as with exact summation on small volumes. Some physical implications of the results are discussed.

Fast, Nonlinear, Fully Probabilistic Inversion of Large Geophysical Problems

NASA Astrophysics Data System (ADS)

Curtis, A.; Shahraeeni, M.; Trampert, J.; Meier, U.; Cho, G.

2010-12-01

Almost all Geophysical inverse problems are in reality nonlinear. Fully nonlinear inversion including non-approximated physics, and solving for probability distribution functions (pdf’s) that describe the solution uncertainty, generally requires sampling-based Monte-Carlo style methods that are computationally intractable in most large problems. In order to solve such problems, physical relationships are usually linearized leading to efficiently-solved, (possibly iterated) linear inverse problems. However, it is well known that linearization can lead to erroneous solutions, and in particular to overly optimistic uncertainty estimates. What is needed across many Geophysical disciplines is a method to invert large inverse problems (or potentially tens of thousands of small inverse problems) fully probabilistically and without linearization. This talk shows how very large nonlinear inverse problems can be solved fully probabilistically and incorporating any available prior information using mixture density networks (driven by neural network banks), provided the problem can be decomposed into many small inverse problems. In this talk I will explain the methodology, compare multi-dimensional pdf inversion results to full Monte Carlo solutions, and illustrate the method with two applications: first, inverting surface wave group and phase velocities for a fully-probabilistic global tomography model of the Earth’s crust and mantle, and second inverting industrial 3D seismic data for petrophysical properties throughout and around a subsurface hydrocarbon reservoir. The latter problem is typically decomposed into 104 to 105 individual inverse problems, each solved fully probabilistically and without linearization. The results in both cases are sufficiently close to the Monte Carlo solution to exhibit realistic uncertainty, multimodality and bias. This provides far greater confidence in the results, and in decisions made on their basis.

Implications of Middle School Behavior Problems for High School Graduation and Employment Outcomes of Young Adults: Estimation of a Recursive Model.

PubMed

Karakus, Mustafa C; Salkever, David S; Slade, Eric P; Ialongo, Nicholas; Stuart, Elizabeth

2012-01-01

The potentially serious adverse impacts of behavior problems during adolescence on employment outcomes in adulthood provide a key economic rationale for early intervention programs. However, the extent to which lower educational attainment accounts for the total impact of adolescent behavior problems on later employment remains unclear As an initial step in exploring this issue, we specify and estimate a recursive bivariate probit model that 1) relates middle school behavior problems to high school graduation and 2) models later employment in young adulthood as a function of these behavior problems and of high school graduation. Our model thus allows for both a direct effect of behavior problems on later employment as well as an indirect effect that operates via graduation from high school. Our empirical results, based on analysis of data from the NELS, suggest that the direct effects of externalizing behavior problems on later employment are not significant but that these problems have important indirect effects operating through high school graduation.

Sleeping with technology: cognitive, affective, and technology usage predictors of sleep problems among college students.

PubMed

Rosen, Larry; Carrier, Louis M; Miller, Aimee; Rokkum, Jeffrey; Ruiz, Abraham

2016-03-01

Sleep problems related to technology affect college students through several potential mechanisms including displacement of sleep due to technology use, executive functioning abilities, and the impact of emotional states related to stress and anxiety about technology availability. In the present study, cognitive and affective factors that influence technology usage were examined for their impact upon sleep problems. More than 700 US college students completed an online questionnaire addressing technology usage, anxiety/dependence, executive functioning, nighttime phone usage, bedtime phone location, and sleep problems. A path model controlling for background variables was tested using the data. The results showed that executive dysfunction directly predicted sleep problems as well as affected sleep problems through nighttime awakenings. In addition, anxiety/dependence increased daily smartphone usage and also increased nighttime awakenings, which, in turn, affected sleep problems. Thus, both the affective and cognitive factors that influence technology usage affected sleep problems. Copyright © 2016 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

A process for Decision-making after Pilot and feasibility Trials (ADePT): development following a feasibility study of a complex intervention for pelvic organ prolapse

PubMed Central

2013-01-01

Background Current Medical Research Council (MRC) guidance on complex interventions advocates pilot trials and feasibility studies as part of a phased approach to the development, testing, and evaluation of healthcare interventions. In this paper we discuss the results of a recent feasibility study and pilot trial for a randomized controlled trial (RCT) of pelvic floor muscle training for prolapse (ClinicalTrials.gov: NCT01136889). The ways in which researchers decide to respond to the results of feasibility work may have significant repercussions for both the nature and degree of tension between internal and external validity in a definitive trial. Methods We used methodological issues to classify and analyze the problems that arose in the feasibility study. Four centers participated with the aim of randomizing 50 women. Women were eligible if they had prolapse of any type, of stage I to IV, and had a pessary successfully fitted. Postal questionnaires were administered at baseline, 6 months, and 7 months post-randomization. After identifying problems arising within the pilot study we then sought to locate potential solutions that might minimize the trade-off between a subsequent explanatory versus pragmatic trial. Results The feasibility study pointed to significant potential problems in relation to participant recruitment, features of the intervention, acceptability of the intervention to participants, and outcome measurement. Finding minimal evidence to support our decision-making regarding the transition from feasibility work to a trial, we developed a systematic process (A process for Decision-making after Pilot and feasibility Trials (ADePT)) which we subsequently used as a guide. The process sought to: 1) encourage the systematic identification and appraisal of problems and potential solutions; 2) improve the transparency of decision-making processes; and 3) reveal the tensions that exist between pragmatic and explanatory choices. Conclusions We have developed a process that may aid researchers in their attempt to identify the most appropriate solutions to problems identified within future pilot and feasibility RCTs. The process includes three key steps: a decision about the type of problem, the identification of all solutions (whether addressed within the intervention, trial design or clinical context), and a systematic appraisal of these solutions. PMID:24160371

Case histories of building material problems caused by condensation at an enclosed swimming pool and an enclosed ice rink

DOE Office of Scientific and Technical Information (OSTI.GOV)

VanGeem, M.G.; Farahmandpour, K.; Gajda, J.

1999-07-01

Enclosed swimming pools and ice rinks in winter climates have the potential for high indoor relative humidities and cold building materials. These elements can contribute to condensation and premature deterioration of building materials. Case histories are provided for an enclosed swimming pool and an enclosed ice rink with condensation problems. An evaluation was performed after roof leaks were reported at a recently constructed indoor swimming pool in a Chicago suburb. After a preliminary inspection, it was evident that the reported leaks were related to building moisture problems rather than a roof leak. Exterior brick masonry exhibited heavy efflorescence in themore » area of the swimming pools, and water streaks were visible on the exterior walls below the eaves. The evaluation included laboratory testing, a visual inspection, field tests and measurements, and analyses for condensation potential. Results of the evaluation indicated the presence of condensed moisture as a direct cause of the observed water stains, and masonry efflorescence. Recommended corrective actions developed. A 54-year-old enclosed ice rink in New England was under investigation to determine the cause of a deteriorated wood deck roof. The building did not have dehumidification or air handling systems, and was heated only when occupied. The evaluation included visual inspection and analyses for condensation potential. Results of the evaluation indicated condensation within the wood decking and insulation during winter months, and high relative humidities that prohibited drying during the spring, summer, and fall. These conditions, over an extended number of years, resulted in decay of the wood decking.« less

Image Registration and Data Assimilation as a QUBO on the D-Wave Quantum Annealer

NASA Astrophysics Data System (ADS)

Pelissier, C.; LeMoigne, J.; Halem, M.; Simpson, D. G.; Clune, T.

2016-12-01

The advent of the commercially available D-Wave quantum annealer has for the first time allowed investigations of the potential of quantum effects to efficiently carry out certain numerical tasks. The D-Wave computer was initially promoted as a tool to solve Quadratic Unconstrained Binary Optimization problems (QUBOs), but currently, it is also being used to generate the Boltzmann statistics required to train Restricted Boltzmann machines (RBMs). We consider the potential of this new architecture in performing numerical computations required to estimate terrestrial carbon fluxes from OCO-2 observations using the LIS model. The use of RBMs is being investigated in this work, but here we focus on the D-Wave as a QUBO solver, and it's potential to carry out image registration and data assimilation. QUBOs are formulated for both problems and results generated using the D-Wave 2Xtm at the NAS supercomputing facility are presented.

Random Evolutionary Dynamics Driven by Fitness and House-of-Cards Mutations: Sampling Formulae

NASA Astrophysics Data System (ADS)

Huillet, Thierry E.

2017-07-01

We first revisit the multi-allelic mutation-fitness balance problem, especially when mutations obey a house of cards condition, where the discrete-time deterministic evolutionary dynamics of the allelic frequencies derives from a Shahshahani potential. We then consider multi-allelic Wright-Fisher stochastic models whose deviation to neutrality is from the Shahshahani mutation/selection potential. We next focus on the weak selection, weak mutation cases and, making use of a Gamma calculus, we compute the normalizing partition functions of the invariant probability densities appearing in their Wright-Fisher diffusive approximations. Using these results, generalized Ewens sampling formulae (ESF) from the equilibrium distributions are derived. We start treating the ESF in the mixed mutation/selection potential case and then we restrict ourselves to the ESF in the simpler house-of-cards mutations only situation. We also address some issues concerning sampling problems from infinitely-many alleles weak limits.

Stability of the Tonks–Langmuir discharge pre-sheath

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tskhakaya, D. D.; Kos, L.; Tskhakaya, D.

The article formulates the stability problem of the plasma sheath in the Tonks–Langmuir discharge. Using the kinetic description of the ion gas, i.e., the stability of the potential shape in the quasi-neutral pre-sheath regarding the high and low frequency, the perturbations are investigated. The electrons are assumed to be Maxwell–Boltzmann distributed. Regarding high-frequency perturbations, the pre-sheath is shown to be stable. The stability problem regarding low-frequency perturbations can be reduced to an analysis of the “diffusion like” equation, which results in the instability of the potential distribution in the pre-sheath. By means of the Particle in Cell simulations, also themore » nonlinear stage of low frequency oscillations is investigated. Comparing the figure obtained with the figure for linear stage, one can find obvious similarity in the spatial-temporal behavior of the potential.« less

Management of toxic cyanobacteria for drinking water production of Ain Zada Dam.

PubMed

Saoudi, Amel; Brient, Luc; Boucetta, Sabrine; Ouzrout, Rachid; Bormans, Myriam; Bensouilah, Mourad

2017-07-01

Blooms of toxic cyanobacteria in Algerian reservoirs represent a potential health problem, mainly from drinking water that supplies the local population of Ain Zada (Bordj Bou Arreridj). The objective of this study is to monitor, detect, and identify the existence of cyanobacteria and microcystins during blooming times. Samples were taken in 2013 from eight stations. The results show that three potentially toxic cyanobacterial genera with the species Planktothrix agardhii were dominant. Cyanobacterial biomass, phycocyanin (PC) concentrations, and microcystin (MC) concentrations were high in the surface layer and at 14 m depth; these values were also high in the treated water. On 11 May 2013, MC concentrations were 6.3 μg/L in MC-LR equivalent in the drinking water. This study shows for the first time the presence of cyanotoxins in raw and treated waters, highlighting that regular monitoring of cyanobacteria and cyanotoxins must be undertaken to avoid potential health problems.

Well-posedness and Scattering for the Boltzmann Equations: Soft Potential with Cut-off

NASA Astrophysics Data System (ADS)

He, Lingbing; Jiang, Jin-Cheng

2017-07-01

We prove the global existence of the unique mild solution for the Cauchy problem of the cut-off Boltzmann equation for soft potential model γ =2-N with initial data small in L^N_{x,v} where N=2,3 is the dimension. The proof relies on the existing inhomogeneous Strichartz estimates for the kinetic equation by Ovcharov (SIAM J Math Anal 43(3):1282-1310, 2011) and convolution-like estimates for the gain term of the Boltzmann collision operator by Alonso et al. (Commun Math Phys 298:293-322, 2010). The global dynamics of the solution is also characterized by showing that the small global solution scatters with respect to the kinetic transport operator in L^N_{x,v}. Also the connection between function spaces and cut-off soft potential model -N<γ <2-N is characterized in the local well-posedness result for the Cauchy problem with large initial data.

A gauged finite-element potential formulation for accurate inductive and galvanic modelling of 3-D electromagnetic problems

NASA Astrophysics Data System (ADS)

Ansari, S. M.; Farquharson, C. G.; MacLachlan, S. P.

2017-07-01

In this paper, a new finite-element solution to the potential formulation of the geophysical electromagnetic (EM) problem that explicitly implements the Coulomb gauge, and that accurately computes the potentials and hence inductive and galvanic components, is proposed. The modelling scheme is based on using unstructured tetrahedral meshes for domain subdivision, which enables both realistic Earth models of complex geometries to be considered and efficient spatially variable refinement of the mesh to be done. For the finite-element discretization edge and nodal elements are used for approximating the vector and scalar potentials respectively. The issue of non-unique, incorrect potentials from the numerical solution of the usual incomplete-gauged potential system is demonstrated for a benchmark model from the literature that uses an electric-type EM source, through investigating the interface continuity conditions for both the normal and tangential components of the potential vectors, and by showing inconsistent results obtained from iterative and direct linear equation solvers. By explicitly introducing the Coulomb gauge condition as an extra equation, and by augmenting the Helmholtz equation with the gradient of a Lagrange multiplier, an explicitly gauged system for the potential formulation is formed. The solution to the discretized form of this system is validated for the above-mentioned example and for another classic example that uses a magnetic EM source. In order to stabilize the iterative solution of the gauged system, a block diagonal pre-conditioning scheme that is based upon the Schur complement of the potential system is used. For all examples, both the iterative and direct solvers produce the same responses for the potentials, demonstrating the uniqueness of the numerical solution for the potentials and fixing the problems with the interface conditions between cells observed for the incomplete-gauged system. These solutions of the gauged system also produce the physically anticipated behaviours for the inductive and galvanic components of the electric field. For a realistic geophysical scenario, the gauged scheme is also used to synthesize the magnetic field response of a model of the Ovoid ore deposit at Voisey's Bay, Labrador, Canada. The results are in good agreement with the helicopter-borne EM data from the real survey, and the inductive and galvanic parts of the current density show expected behaviours.

Leadership in nursing-current perspectives.

PubMed

Manocha, Sneh Lata

2008-02-01

A leader who serves with vision, (plans for future needs and problem solving) has courage, (takes initiative and leads followers to positive results) and is reality oriented (realizes that the fundamental changes are necessary in our attitude towards risk taking, assertiveness and difference in opinion) is a great leader who has potential for extraordinary results.

Care and Feeding of a Changing Faculty in the 1990s: The Issues.

ERIC Educational Resources Information Center

Sorby, Donald L.

1990-01-01

Eleven important trends seen as potential causes for pharmacy faculty discontent and stress in the 1990s are examined, including trends resulting from resource changes, technological and scientific advances, and changes in society and health care delivery. Resulting problems and possible strategies for addressing them are offered. (MSE)

Rank-k modification methods for recursive least squares problems

NASA Astrophysics Data System (ADS)

Olszanskyj, Serge; Lebak, James; Bojanczyk, Adam

1994-09-01

In least squares problems, it is often desired to solve the same problem repeatedly but with several rows of the data either added, deleted, or both. Methods for quickly solving a problem after adding or deleting one row of data at a time are known. In this paper we introduce fundamental rank-k updating and downdating methods and show how extensions of rank-1 downdating methods based on LINPACK, Corrected Semi-Normal Equations (CSNE), and Gram-Schmidt factorizations, as well as new rank-k downdating methods, can all be derived from these fundamental results. We then analyze the cost of each new algorithm and make comparisons tok applications of the corresponding rank-1 algorithms. We provide experimental results comparing the numerical accuracy of the various algorithms, paying particular attention to the downdating methods, due to their potential numerical difficulties for ill-conditioned problems. We then discuss the computation involved for each downdating method, measured in terms of operation counts and BLAS calls. Finally, we provide serial execution timing results for these algorithms, noting preferable points for improvement and optimization. From our experiments we conclude that the Gram-Schmidt methods perform best in terms of numerical accuracy, but may be too costly for serial execution for large problems.

Disease-Induced Skeletal Muscle Atrophy and Fatigue

PubMed Central

Powers, Scott K.; Lynch, Gordon S.; Murphy, Kate T.; Reid, Michael B.; Zijdewind, Inge

2016-01-01

Numerous health problems including acute critical illness, cancer, diseases associated with chronic inflammation, and neurological disorders often result in skeletal muscle weakness and fatigue. Disease-related muscle atrophy and fatigue is an important clinical problem because acquired skeletal muscle weakness can increase the duration of hospitalization, result in exercise limitation, and contribute to a poor quality of life. Importantly, skeletal muscle atrophy is also associated with increased morbidity and mortality of patients. Therefore, improving our understanding of the mechanism(s) responsible for skeletal muscle weakness and fatigue in patients is a required first step to develop clinical protocols to prevent these skeletal muscle problems. This review will highlight the consequences and potential mechanisms responsible for skeletal muscle atrophy and fatigue in patients suffering from acute critical illness, cancer, chronic inflammatory diseases, and neurological disorders. PMID:27128663

33 CFR 332.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... following terms are defined: Adaptive management means the development of a management strategy that... guides modification of those projects to optimize performance. It includes the selection of appropriate... monitoring results to identify potential problems of a compensatory mitigation project and the identification...

Effects of research tool patents on biotechnology innovation in a developing country: A case study of South Korea

PubMed Central

Kang, Kyung-Nam; Ryu, Tae-Kyu; Lee, Yoon-Sik

2009-01-01

Background Concerns have recently been raised about the negative effects of patents on innovation. In this study, the effects of patents on innovations in the Korean biotech SMEs (small and medium-sized entrepreneurs) were examined using survey data and statistical analysis. Results The survey results of this study provided some evidence that restricted access problems have occurred even though their frequency was not high. Statistical analysis revealed that difficulties in accessing patented research tools were not negatively correlated with the level of innovation performance and attitudes toward the patent system. Conclusion On the basis of the results of this investigation in combination with those of previous studies, we concluded that although restricted access problems have occurred, this has not yet deterred innovation in Korea. However, potential problems do exist, and the effects of restricted access should be constantly scrutinized. PMID:19321013

Finite-element grid improvement by minimization of stiffness matrix trace

NASA Technical Reports Server (NTRS)

Kittur, Madan G.; Huston, Ronald L.; Oswald, Fred B.

1989-01-01

A new and simple method of finite-element grid improvement is presented. The objective is to improve the accuracy of the analysis. The procedure is based on a minimization of the trace of the stiffness matrix. For a broad class of problems this minimization is seen to be equivalent to minimizing the potential energy. The method is illustrated with the classical tapered bar problem examined earlier by Prager and Masur. Identical results are obtained.

Finite-element grid improvement by minimization of stiffness matrix trace

NASA Technical Reports Server (NTRS)

Kittur, Madan G.; Huston, Ronald L.; Oswald, Fred B.

1987-01-01

A new and simple method of finite-element grid improvement is presented. The objective is to improve the accuracy of the analysis. The procedure is based on a minimization of the trace of the stiffness matrix. For a broad class of problems this minimization is seen to be equivalent to minimizing the potential energy. The method is illustrated with the classical tapered bar problem examined earlier by Prager and Masur. Identical results are obtained.

Self-consistent calculation of the Sommerfeld enhancement

DOE PAGES

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.

Exploring Proposals for Resolving the Initial Conditions and Multiverse Problems in Inflation

NASA Astrophysics Data System (ADS)

Panithanpaisal, Nondh; Steinhardt, Paul

2018-01-01

The theory of cosmic inflation with the plateau-like potentials for the scalar field is very successful in predicting standard cosmological parameters. However, if the quantum effects are included, the theory inherently contains serious problems, namely, the multiverse problem and the initial conditions problem. It has been suggested in Mukhanov 2015 and Deen et al. 2016 to add a potential wall to the potential, so that the field never reaches the self-reproduction point. We examine these two proposals by varying the positions of the potential wall as well as varying the initial ratios of kinetic energy, potential energy and curvature. We demonstrate that both proposals are fine-tuned, at best, as they suffer from the drift in the predictions of the spectral tilt (ns) and the tensor-to-scalar ratio (r).

An investigation of student understanding of classical ideas related to quantum mechanics: Potential energy diagrams and spatial probability density

NASA Astrophysics Data System (ADS)

Stephanik, Brian Michael

This dissertation describes the results of two related investigations into introductory student understanding of ideas from classical physics that are key elements of quantum mechanics. One investigation probes the extent to which students are able to interpret and apply potential energy diagrams (i.e., graphs of potential energy versus position). The other probes the extent to which students are able to reason classically about probability and spatial probability density. The results of these investigations revealed significant conceptual and reasoning difficulties that students encounter with these topics. The findings guided the design of instructional materials to address the major problems. Results from post-instructional assessments are presented that illustrate the impact of the curricula on student learning.

Remote monitoring of implantable cardioverter-defibrillators. Problems and implications using a telemonitoring system.

PubMed

Siebermair, J; Clauss, S; Martens, E; Schuessler, F; Oversohl, N; Haserueck, N; Estner, H L; Kääb, S; Wakili, R

2015-04-01

The rising number of implantable devices has led to an increase in device-related workload, e.g., regular interrogation follow-up visits. Telemonitoring systems for implantable cardioverter-defibrillators (ICDs) seem to be a promising tool for reducing workload and costs, and they have the potential of optimizing patient care. However, issues such as practical functionality of ICD telemonitoring in daily routine may affect its broad implementation. The objective of this study was to evaluate potential problems during the implementation of a telemonitoring system, Medtronic CareLink™ (CL™) with respect to the installation and data transmission process. A total of 159 patients with ICDs who were equipped with the CL™ system were evaluated and followed up for 16 months regarding the success rate of the first data transmission via the telemonitoring system. In this cohort, a high rate of nontransmission of 23.9 % was observed after the 16-month follow-up. A detailed interview of these patients (no transmission) revealed that the main reasons for failed transmissions were due to the patients' loss of interest in the concept (approximately 50 %) as well as technical problems (approximately 25 %) with setting up the system. These results indicate that telemonitoring systems bear potential problems and that the evaluation of patient motivation and technical support options seems to play an important role in establishing the functionality of these systems.

Quantum-Inspired Maximizer

NASA Technical Reports Server (NTRS)

Zak, Michail

2008-01-01

A report discusses an algorithm for a new kind of dynamics based on a quantum- classical hybrid-quantum-inspired maximizer. The model is represented by a modified Madelung equation in which the quantum potential is replaced by different, specially chosen 'computational' potential. As a result, the dynamics attains both quantum and classical properties: it preserves superposition and entanglement of random solutions, while allowing one to measure its state variables, using classical methods. Such optimal combination of characteristics is a perfect match for quantum-inspired computing. As an application, an algorithm for global maximum of an arbitrary integrable function is proposed. The idea of the proposed algorithm is very simple: based upon the Quantum-inspired Maximizer (QIM), introduce a positive function to be maximized as the probability density to which the solution is attracted. Then the larger value of this function will have the higher probability to appear. Special attention is paid to simulation of integer programming and NP-complete problems. It is demonstrated that the problem of global maximum of an integrable function can be found in polynomial time by using the proposed quantum- classical hybrid. The result is extended to a constrained maximum with applications to integer programming and TSP (Traveling Salesman Problem).

A new model of Ishikawa diagram for quality assessment

NASA Astrophysics Data System (ADS)

Liliana, Luca

2016-11-01

The paper presents the results of a study concerning the use of the Ishikawa diagram in analyzing the causes that determine errors in the evaluation of theparts precision in the machine construction field. The studied problem was"errors in the evaluation of partsprecision” and this constitutes the head of the Ishikawa diagram skeleton.All the possible, main and secondary causes that could generate the studied problem were identified. The most known Ishikawa models are 4M, 5M, 6M, the initials being in order: materials, methods, man, machines, mother nature, measurement. The paper shows the potential causes of the studied problem, which were firstly grouped in three categories, as follows: causes that lead to errors in assessing the dimensional accuracy, causes that determine errors in the evaluation of shape and position abnormalities and causes for errors in roughness evaluation. We took into account the main components of parts precision in the machine construction field. For each of the three categories of causes there were distributed potential secondary causes on groups of M (man, methods, machines, materials, environment/ medio ambiente-sp.). We opted for a new model of Ishikawa diagram, resulting from the composition of three fish skeletons corresponding to the main categories of parts accuracy.

A unique problem of muscle adaptation from weightlessness: The deceleration deficiency

NASA Technical Reports Server (NTRS)

Stauber, William T.

1989-01-01

Decelerator problems of the knee are emphasized since the lower leg musculature is known to atrophy in response to weightlessness. However, other important decelerator functions are served by the shoulder muscles, in particular the rotator cuff muscles. Problems in these muscles often result in tears and dislocations as seen in baseball pitchers. It is noteworthy that at least one device currently exists that can measure concentric and eccentric muscle loading including a submaximal simulated free weight exercise (i.e., force-controlled) and simultaneously record integrated EMG analysis appropriate for assessment of all muscle functional activities. Studies should be undertaken to provide information as to the performance of maximal and submaximal exercise in space travelers to define potential problems and provide rationale for prevention.

Source localization in an ocean waveguide using supervised machine learning.

PubMed

Niu, Haiqiang; Reeves, Emma; Gerstoft, Peter

2017-09-01

Source localization in ocean acoustics is posed as a machine learning problem in which data-driven methods learn source ranges directly from observed acoustic data. The pressure received by a vertical linear array is preprocessed by constructing a normalized sample covariance matrix and used as the input for three machine learning methods: feed-forward neural networks (FNN), support vector machines (SVM), and random forests (RF). The range estimation problem is solved both as a classification problem and as a regression problem by these three machine learning algorithms. The results of range estimation for the Noise09 experiment are compared for FNN, SVM, RF, and conventional matched-field processing and demonstrate the potential of machine learning for underwater source localization.

A hierarchical model of the evolution of cooperation in cultural systems.

PubMed

Savatsky, K; Reynolds, R G

1989-01-01

In this paper the following problem is addressed: "Under what conditions can a collection of individual organisms learn to cooperate when cooperation appears to outwardly degrade individual performance at the outset. In order to attempt a theoretical solution to this problem, data from a real world problem in anthropology is used. A distributed simulation model of this system was developed to assess its long term behavior using using an approach suggested by Zeigler (Zeigler, B.P., 1984, Multifaceted Modelling and Discrete Event Simulation (Academic Press, London)). The results of the simulation are used to show that although cooperation degrades the performance potential of each individual, it enhances the persistence of the individual's partial solution to the problem in certain situations."

Test-specific control conditions for functional analyses.

PubMed

Fahmie, Tara A; Iwata, Brian A; Querim, Angie C; Harper, Jill M

2013-01-01

Most functional analyses of problem behavior include a common condition (play or noncontingent reinforcement) as a control for both positive and negative reinforcement. However, test-specific conditions that control for each potential source of reinforcement may be beneficial occasionally. We compared responding during alone, ignore, play, and differential reinforcement of other behavior (DRO) control conditions for individuals whose problem behavior was maintained by positive or negative reinforcement. Results showed that all of the conditions were effective controls for problem behavior maintained by positive reinforcement; however, the DRO condition was consistently ineffective as a control for problem behavior maintained by negative reinforcement. Implications for the design of functional analyses and future research are discussed. © Society for the Experimental Analysis of Behavior.

Intertwined Hamiltonians in two-dimensional curved spaces

NASA Astrophysics Data System (ADS)

Aghababaei Samani, Keivan; Zarei, Mina

2005-04-01

The problem of intertwined Hamiltonians in two-dimensional curved spaces is investigated. Explicit results are obtained for Euclidean plane, Minkowski plane, Poincaré half plane (AdS2), de Sitter plane (dS2), sphere, and torus. It is shown that the intertwining operator is related to the Killing vector fields and the isometry group of corresponding space. It is shown that the intertwined potentials are closely connected to the integral curves of the Killing vector fields. Two problems are considered as applications of the formalism presented in the paper. The first one is the problem of Hamiltonians with equispaced energy levels and the second one is the problem of Hamiltonians whose spectrum is like the spectrum of a free particle.

It looks easy! Heuristics for combinatorial optimization problems.

PubMed

Chronicle, Edward P; MacGregor, James N; Ormerod, Thomas C; Burr, Alistair

2006-04-01

Human performance on instances of computationally intractable optimization problems, such as the travelling salesperson problem (TSP), can be excellent. We have proposed a boundary-following heuristic to account for this finding. We report three experiments with TSPs where the capacity to employ this heuristic was varied. In Experiment 1, participants free to use the heuristic produced solutions significantly closer to optimal than did those prevented from doing so. Experiments 2 and 3 together replicated this finding in larger problems and demonstrated that a potential confound had no effect. In all three experiments, performance was closely matched by a boundary-following model. The results implicate global rather than purely local processes. Humans may have access to simple, perceptually based, heuristics that are suited to some combinatorial optimization tasks.

Study of the Z{sub 3} symmetry in QCD at finite temperature and chemical potential using a worm algorithm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krein, Gastao; Leme, Rafael R.; Woitek, Marcio

Traditional Monte Carlo simulations of QCD in the presence of a baryon chemical potential are plagued by the complex phase problem and new numerical approaches are necessary for studying the phase diagram of the theory. In this work we consider a Z{sub 3} Polyakov loop model for the deconfining phase transition in QCD and discuss how a flux representation of the model in terms of dimer and monomer variable solves the complex action problem. We present results of numerical simulations using a worm algorithm for the specific heat and two-point correlation function of Polyakov loops. Evidences of a first ordermore » deconfinement phase transition are discussed.« less

Drinking motives mediate emotion regulation difficulties and problem drinking in college students.

PubMed

Aurora, Pallavi; Klanecky, Alicia K

2016-05-01

Problem drinking in college places students at an increased risk for a wealth of negative consequences including alcohol use disorders. Most research has shown that greater emotion regulation difficulties are related to increased problem drinking, and studies generally assume that drinking is motivated by efforts to cope with or enhance affective experiences. However, there is a lack of research specifically testing this assumption. The current study sought to examine the mediating potential of drinking motives, specifically coping and enhancement, on the relationship between emotion regulation and problem drinking. College participants (N = 200) completed an online survey, consisting of a battery of measures assessing alcohol use behaviors and related variables. Coping drinking motives fully mediated the emotion regulation/problem drinking relationship, and enhancement motives partially mediated this relationship. Exploratory analyses indicated that all four drinking motives (i.e. coping, enhancement, social, and conformity) simultaneously mediated the relationship between emotion regulation and quantity/frequency of alcohol use. However, only coping and enhancement significantly mediated the relationship between emotion regulation and alcohol-related consequences (e.g. alcohol dependence symptoms, alcohol-related injuries). The current results offer direction for potentially modifying brief alcohol interventions in efforts to reduce students' engagement in problem drinking behaviors. For example, interventions might incorporate information on the risks of using alcohol as a means of emotion regulation and offer alternative emotion regulation strategies.

A hybrid-perturbation-Galerkin technique which combines multiple expansions

NASA Technical Reports Server (NTRS)

Geer, James F.; Andersen, Carl M.

1989-01-01

A two-step hybrid perturbation-Galerkin method for the solution of a variety of differential equations type problems is found to give better results when multiple perturbation expansions are employed. The method assumes that there is parameter in the problem formulation and that a perturbation method can be sued to construct one or more expansions in this perturbation coefficient functions multiplied by computed amplitudes. In step one, regular and/or singular perturbation methods are used to determine the perturbation coefficient functions. The results of step one are in the form of one or more expansions each expressed as a sum of perturbation coefficient functions multiplied by a priori known gauge functions. In step two the classical Bubnov-Galerkin method uses the perturbation coefficient functions computed in step one to determine a set of amplitudes which replace and improve upon the gauge functions. The hybrid method has the potential of overcoming some of the drawbacks of the perturbation and Galerkin methods as applied separately, while combining some of their better features. The proposed method is applied, with two perturbation expansions in each case, to a variety of model ordinary differential equations problems including: a family of linear two-boundary-value problems, a nonlinear two-point boundary-value problem, a quantum mechanical eigenvalue problem and a nonlinear free oscillation problem. The results obtained from the hybrid methods are compared with approximate solutions obtained by other methods, and the applicability of the hybrid method to broader problem areas is discussed.

Drinking to Cope With Depressive Symptoms and Ruminative Thinking: A Multiple Mediation Model Among College Students.

PubMed

Bravo, Adrian J; Pearson, Matthew R; Henson, James M

2017-01-02

Understanding the potential psychosocial mechanisms that explain (i.e., mediate) the associations between depressive symptoms and alcohol-related problems can improve interventions targeting college students. The current research examined four distinct facets of rumination (e.g., problem-focused thoughts, counterfactual thinking, repetitive thoughts, and anticipatory thoughts) and drinking to cope motives as potential explanatory mechanisms by which depressive symptoms are associated with increased alcohol-related problems. Participants were undergraduate students from a large, southeastern university in the United States that consumed at least one drink per typical week in the previous month (n = 403). The majority of participants were female (n = 291; 72.2%), identified as being either White, non-Hispanic (n = 210; 52.1%), or African American (n = 110; 27.3%), and reported a mean age of 21.92 (SD = 5.75) years. Structural equation modeling was conducted examining the concurrent associations between depressive symptoms, rumination facets, drinking to cope motives, and alcohol-related problems (i.e., cross-sectional). There was one significant double-mediated association that suggested that increased depressive symptoms is associated with increased problem-focused thoughts, which is associated with higher drinking to cope motives and alcohol-related problems. Conclusions/Importance: Our results suggests that problem-focused thoughts at least partially explains the associations between depression and maladaptive coping (i.e., drinking to cope), which in turn is related to problematic drinking among college students. Limitations and future directions are discussed.

The interaction between gambling activities and modes of access: a comparison of Internet-only, land-based only, and mixed-mode gamblers.

PubMed

Gainsbury, Sally M; Russell, Alex; Blaszczynski, Alex; Hing, Nerilee

2015-02-01

Research suggests that Internet-based gambling includes risk factors that may increase gambling problems. The current study aimed to investigate subgroups of gamblers to identify the potential harms associated with various forms and modes of gambling. An online survey was completed by 4,594 respondents identified as Internet-only (IG), land-based only (LBGs), or mixed-mode (MMG) gamblers based on self-reported gambling behaviour in the last 12months. Results showed significant socio-demographic differences between groups, with the LBGs being the oldest and MMGs the youngest. MMGs engaged in the greatest variety of gambling forms, had the highest average problem gambling severity scores, and were more likely to attribute problems to sports betting than the other groups. IGs were involved in the lowest number of divergent gambling activities, most likely to gamble frequently on sports and races, and attribute problems to these forms. Compared to the other groups, LBs had a higher proportion of problem gamblers than IGs and were most likely to play electronic gaming machines weekly, with this form of gambling contributing to problems at a substantially greater rate. This study confirms the importance of considering gambling involvement across subgroups of Internet or land-based gamblers. There is a need to consider the interaction between forms and modes of gambling to advance our understanding of the potential risk of mode of gambling to contribute to problems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of triangular element orientation on finite element solutions of the Helmholtz equation

NASA Technical Reports Server (NTRS)

Baumeister, K. J.

1986-01-01

The Galerkin finite element solutions for the scalar homogeneous Helmholtz equation are presented for no reflection, hard wall, and potential relief exit terminations with a variety of triangular element orientations. For this group of problems, the correlation between the accuracy of the solution and the orientation of the linear triangle is examined. Nonsymmetric element patterns are found to give generally poor results in the model problems investigated, particularly for cases where standing waves exist. For a fixed number of vertical elements, the results showed that symmetric element patterns give much better agreement with corresponding exact analytical results. In laminated wave guide application, the symmetric pyramid pattern is convenient to use and is shown to give excellent results.

Unpacking personalized feedback: an exploratory study of the impact of its components and the reactions it elicits among problem drinking men who have sex with men.

PubMed

Kuerbis, Alexis Noel; Schaumberg, Katherine; Davis, Christine M; Hail, Lisa; Morgenstern, Jon

2014-03-01

Personalized feedback (PF) has demonstrated effectiveness in reducing drinking. Few studies have examined its effectiveness with adult problem drinkers or its potential mediators or moderators, including developing discrepancy. This study aimed to identify potential mediators and moderators of PF provided to adult problem drinking men who have sex with men (PDMSM). An exploratory analysis of PF provided to PDMSM in the context of modified behavioral self-control therapy (N = 90). The association of individual items of PF, severity of PF, and independently rated, in-session participant reactions to PF with drinking outcomes (mean drinks per drinking day, MDDD) were examined using correlations and logistic and linear regression. Significant pre-post differences in MDDD emerged. Other drug risk, family risk, and having an abnormal liver enzyme test result were significantly associated with proxies for developed discrepancy in expected directions; however, no PF item or reaction to PF predicted drinking outcomes. Severity of PF was not associated with participant reactions or drinking outcome. PF may be an effective intervention for PDMSM. Further research is needed to identify potential mediators and moderators of PF among adults.

Addressing the stimulant treatment gap: A call to investigate the therapeutic benefits potential of cannabinoids for crack-cocaine use.

PubMed

Fischer, Benedikt; Kuganesan, Sharan; Gallassi, Andrea; Malcher-Lopes, Renato; van den Brink, Wim; Wood, Evan

2015-12-01

Crack-cocaine use is prevalent in numerous countries, yet concentrated primarily - largely within urban contexts - in the Northern and Southern regions of the Americas. It is associated with a variety of behavioral, physical and mental health and social problems which gravely affect users and their environments. Few evidence-based treatments for crack-cocaine use exist and are available to users in the reality of street drug use. Numerous pharmacological treatments have been investigated but with largely disappointing results. An important therapeutic potential for crack-cocaine use may rest in cannabinoids, which have recently seen a general resurgence for varied possible therapeutic usages for different neurological diseases. Distinct potential therapeutic benefits for crack-cocaine use and common related adverse symptoms may come specifically from cannabidiol (CBD) - one of the numerous cannabinoid components found in cannabis - with its demonstrated anxiolytic, anti-psychotic, anti-convulsant effects and potential benefits for sleep and appetite problems. The possible therapeutic prospects of cannabinoids are corroborated by observational studies from different contexts documenting crack-cocaine users' 'self-medication' efforts towards coping with crack-cocaine-related problems, including withdrawal and craving, impulsivity and paranoia. Cannabinoid therapeutics offer further benefits of being available in multiple formulations, are low in adverse risk potential, and may easily be offered in community-based settings which may add to their feasibility as interventions for - predominantly marginalized - crack-cocaine user populations. Supported by the dearth of current therapeutic options for crack-cocaine use, we are advocating for the implementation of a rigorous research program investigating the potential therapeutic benefits of cannabinoids for crack-cocaine use. Given the high prevalence of this grave substance use problem in the Americas, opportunities for such research should urgently be created and facilitated there. Copyright © 2015 Elsevier B.V. All rights reserved.

The stigma of mental health problems in the military.

PubMed

Greene-Shortridge, Tiffany M; Britt, Thomas W; Castro, Carl Andrew

2007-02-01

The present review addresses the perceived stigma associated with admitting a mental health problem and seeking help for that problem in the military. Evidence regarding the public stigma associated with mental disorders is reviewed, indicating that the public generally holds negative stereotypes toward individuals with psychological problems, leading to potential discrimination toward these individuals. The internalization of these negative beliefs results in self-stigma, leading to reduced self-esteem and motivation to seek help. Even if soldiers form an intention to seek help for their psychological difficulty, barriers to mental health care may prevent the soldier from receiving the help they need. An overall model is proposed to illustrate how the stigma associated with psychological problems can prevent soldiers getting needed help for psychological difficulties and proposed interventions for reducing stigma in a civilian context are considered for military personnel.

Water quality modeling using geographic information system (GIS) data

NASA Technical Reports Server (NTRS)

Engel, Bernard A

1992-01-01

Protection of the environment and natural resources at the Kennedy Space Center (KSC) is of great concern. The potential for surface and ground water quality problems resulting from non-point sources of pollution was examined using models. Since spatial variation of parameters required was important, geographic information systems (GIS) and their data were used. The potential for groundwater contamination was examined using the SEEPAGE (System for Early Evaluation of the Pollution Potential of Agricultural Groundwater Environments) model. A watershed near the VAB was selected to examine potential for surface water pollution and erosion using the AGNPS (Agricultural Non-Point Source Pollution) model.

[Influence of excessive internet use on auditory event-related potential].

PubMed

Zhao, Xin; Yu, Hongqiang; Zhan, Qisheng; Wang, Mingshi

2008-12-01

At present, young people's internet addiction has become a serious social problem and on important concern in China. Comparison studies of auditory event-related potential (ERP) between 9 excessive internet users and 9 common internet users were carried out. The obvious influences of excessive internet use on the users were observed. The result suggests that excessive internet use may have some influences on cerebral cognitive function.

Mothers of children with externalizing behavior problems: cognitive risk factors for abuse potential and discipline style and practices.

PubMed

McElroy, Erika M; Rodriguez, Christina M

2008-08-01

Utilizing the conceptual framework of the Social Information Processing (SIP) model (Milner, 1993, 2000), associations between cognitive risk factors and child physical abuse risk and maladaptive discipline style and practices were examined in an at-risk population. Seventy-three mothers of 5-12-year-old children, who were identified by their therapist as having an externalizing behavior problem, responded to self-report measures pertaining to cognitive risk factors (empathic perspective taking, frustration tolerance, developmental expectations, parenting locus of control), abuse risk, and discipline style and practices. The Child Behavior Checklist (CBCL) provided a confirmation of the child's externalizing behaviors independent of the therapist's assessment. The results of this study suggest several cognitive risk factors significantly predict risk of parental aggression toward children. A parent's ability to empathize and take the perspective of their child, parental locus of control, and parental level of frustration tolerance were significant predictors of abuse potential (accounting for 63% of the variance) and inappropriate discipline practices (accounting for 55% of the variance). Findings of the present study provide support for processes theorized in the SIP model. Specifically, results underscore the potential role of parents' frustration tolerance, developmental expectations, locus of control, and empathy as predictive of abuse potential and disciplinary style in an at-risk sample.

Hypersensitivity to reward in problem gamblers.

PubMed

Hewig, Johannes; Kretschmer, Nora; Trippe, Ralf H; Hecht, Holger; Coles, Michael G H; Holroyd, Clay B; Miltner, Wolfgang H R

2010-04-15

Recent research has begun to examine the neurophysiologic basis of pathological gambling. However, direct evidence of a behavioral deficit and an accompanying neurofunctional deviation in a realistic gambling context such as Black Jack has not yet been reported. Electroencephalogram was recorded while 20 problem gamblers and 21 control participants played a computerized version of Black Jack. Participants were asked to decide at point scores between 11 and 21 whether they wanted to take another card ("hit") to arrive closer to 21 than the opponent (simulated by computer) or not to take another card ("sit") to avoid going over 21 ("bust"). At a critical point score of 16, problem gamblers decided more often to hit despite losses due to a bust on the preceding trial, whereas control participants decided more often to sit under these conditions. Furthermore, problem gamblers showed more reward-related positive amplitudes in the event-related brain potential than control participants after successful hit decisions at 16. Here we provide experimental evidence for high-risk taking behavior in gamblers and its correlate in event-related brain potentials. Our results suggest that high-risk-taking behavior in problem gamblers is associated with an increased reward-related neural response to infrequent successes of this behavior. Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

The curse of invertase

USDA-ARS?s Scientific Manuscript database

Among the greatest quality concerns for chip and fry processing potato tubers are cold-induced sweetening, sugar end defects, translucent ends, stem-end chip defect and high acrylamide-forming potential. These problems all result from elevated amounts of glucose and fructose, reducing sugars produce...

Problems and solutions in DWI enforcement systems

DOT National Transportation Integrated Search

1998-01-01

This report documents the results of a study aimed at identifying where and how alcohol-impaired drivers slip through the cracks in the criminal justice system. It also suggests potential fixes to close those loopholes. The report is based on informa...

Opto-mechatronics issues in solid immersion lens based near-field recording

NASA Astrophysics Data System (ADS)

Park, No-Cheol; Yoon, Yong-Joong; Lee, Yong-Hyun; Kim, Joong-Gon; Kim, Wan-Chin; Choi, Hyun; Lim, Seungho; Yang, Tae-Man; Choi, Moon-Ho; Yang, Hyunseok; Rhim, Yoon-Chul; Park, Young-Pil

2007-06-01

We analyzed the effects of an external shock on a collision problem in a solid immersion lens (SIL) based near-field recording (NFR) through a shock response analysis and proposed a possible solution to this problem with adopting a protector and safety mode. With this proposed method the collision between SIL and media can be avoided. We showed possible solution for contamination problem in SIL based NFR through a numerical air flow analysis. We also introduced possible solid immersion lens designs to increase the fabrication and assembly tolerances of an optical head with replicated lens. Potentially, these research results could advance NFR technology for commercial product.

Nanobiotechnology for the Environment: Innovative Solutions for the Management of Harmful Algal Blooms.

PubMed

Gellert, Matthew R; Kim, Beum Jun; Reffsin, Samuel E; Jusuf, Sebastian E; Wagner, Nicole D; Winans, Stephen C; Wu, Mingming

2017-12-04

Nanobiotechnology has played important roles in solving contemporary health problems, including cancer and diabetes, but has not yet been widely exploited for problems in food security and environmental protection. Water scarcity is an emerging worldwide problem as a result of climate change and population increase. Current methods of managing water resources are not efficient or sustainable. In this perspective, we focus on harmful algal blooms to demonstrate how nanobiotechnology can be explored to understand microbe-environment interactions and allow for toxin/pollutant detection with significantly improved sensitivity. These capabilities hold potential for future development of sustainable solutions for drinking water management.

Integrated Hardware and Software for No-Loss Computing

NASA Technical Reports Server (NTRS)

James, Mark

2007-01-01

When an algorithm is distributed across multiple threads executing on many distinct processors, a loss of one of those threads or processors can potentially result in the total loss of all the incremental results up to that point. When implementation is massively hardware distributed, then the probability of a hardware failure during the course of a long execution is potentially high. Traditionally, this problem has been addressed by establishing checkpoints where the current state of some or part of the execution is saved. Then in the event of a failure, this state information can be used to recompute that point in the execution and resume the computation from that point. A serious problem arises when one distributes a problem across multiple threads and physical processors is that one increases the likelihood of the algorithm failing due to no fault of the scientist but as a result of hardware faults coupled with operating system problems. With good reason, scientists expect their computing tools to serve them and not the other way around. What is novel here is a unique combination of hardware and software that reformulates an application into monolithic structure that can be monitored in real-time and dynamically reconfigured in the event of a failure. This unique reformulation of hardware and software will provide advanced aeronautical technologies to meet the challenges of next-generation systems in aviation, for civilian and scientific purposes, in our atmosphere and in atmospheres of other worlds. In particular, with respect to NASA s manned flight to Mars, this technology addresses the critical requirements for improving safety and increasing reliability of manned spacecraft.

Biomedical Applications of NASA Science and Technology

NASA Technical Reports Server (NTRS)

Brown, James N., Jr.

1968-01-01

During the period 15 September 1968 to 14 December 1968, the NASA supported Biomedical Application Team at the Research Triangle Institute has identified 6 new problems, performed significant activities on 15 of the active problems identified previously, performed 5 computer searches of the NASA aerospace literature, and maintained one current awareness search. As a partial result of these activities, one technology transfer was accomplished. As a part of continuing problem review, 13 problems were classified inactive. Activities during the quarter involved all phases of team activity with respect to biomedical problems. As has been observed in preceding years, it has been exceedingly difficult to arrange meetings with medical investigators during the fourth quarter of the calendar year. This is a result of a combination of factors. Teaching requirements, submission of grant applications and holidays are the most significant factors involved. As a result, the numbers of new problems identified and of transfers and potential transfers are relatively low during this quarter. Most of our activities have thus been directed toward obtaining information related to problems already identified. Consequently, during the next quarter we will follow up on these activities with the expectation that transfers will be accomplished on a number of them. In addition, the normal availability of researchers to the team is expected to be restored during this quarter, permitting an increase in new problem identification activities as well as follow-up with other researchers on old problems. Another activity scheduled for the next quarter is consultation with several interested biomedical equipment manufacturers to explore means of effective interaction between the Biomedical Application Team and these companies.

Social and economic conditions in childhood and the progression of functional health problems from midlife into old age

PubMed Central

Agahi, Neda; Shaw, Benjamin A; Fors, Stefan

2014-01-01

Background Childhood living conditions have been found to predict health and mortality in midlife and in old age. This study examines the associations between social and economic childhood conditions and the onset and progression of functional health problems from midlife into old age, and the extent to which potential associations are mediated by educational attainment and smoking. Methods Data from the Level of Living Survey and the Swedish Panel Study of Living Conditions of the Oldest Old were merged to create a longitudinal data set with five repeated measures from 1968 to 2004 (n=1765, aged 30–50 years and free from functional health problems at baseline). Multilevel regression models were used to analyse retrospective reports of social and economic conditions in childhood (eg, conflicts or economic problems in the family) in relation to the progression of functional health problems over the 36-year period. Results Results showed that social and economic disadvantages in childhood were associated with an earlier onset and a faster progression of functional health problems from midlife into old age. Subsequent models showed that differences in educational attainment, but not smoking, explained much of the association between childhood disadvantages and trajectories of functional health problems. Conclusions According to these results, adverse social and economic conditions in childhood affect the development of functional health problems from midlife into old age indirectly through less favourable life careers, including lower education. Creating equal opportunities for educational attainment may help reduce the long-term effects of disadvantaged childhood conditions and postpone functional health problems. PMID:24759781

Forward and Inverse Modeling of Self-potential. A Tomography of Groundwater Flow and Comparison Between Deterministic and Stochastic Inversion Methods

NASA Astrophysics Data System (ADS)

Quintero-Chavarria, E.; Ochoa Gutierrez, L. H.

2016-12-01

Applications of the Self-potential Method in the fields of Hydrogeology and Environmental Sciences have had significant developments during the last two decades with a strong use on groundwater flows identification. Although only few authors deal with the forward problem's solution -especially in geophysics literature- different inversion procedures are currently being developed but in most cases they are compared with unconventional groundwater velocity fields and restricted to structured meshes. This research solves the forward problem based on the finite element method using the St. Venant's Principle to transform a point dipole, which is the field generated by a single vector, into a distribution of electrical monopoles. Then, two simple aquifer models were generated with specific boundary conditions and head potentials, velocity fields and electric potentials in the medium were computed. With the model's surface electric potential, the inverse problem is solved to retrieve the source of electric potential (vector field associated to groundwater flow) using deterministic and stochastic approaches. The first approach was carried out by implementing a Tikhonov regularization with a stabilized operator adapted to the finite element mesh while for the second a hierarchical Bayesian model based on Markov chain Monte Carlo (McMC) and Markov Random Fields (MRF) was constructed. For all implemented methods, the result between the direct and inverse models was contrasted in two ways: 1) shape and distribution of the vector field, and 2) magnitude's histogram. Finally, it was concluded that inversion procedures are improved when the velocity field's behavior is considered, thus, the deterministic method is more suitable for unconfined aquifers than confined ones. McMC has restricted applications and requires a lot of information (particularly in potentials fields) while MRF has a remarkable response especially when dealing with confined aquifers.

Developmental pathways from childhood conduct problems to early adult depression: findings from the ALSPAC cohort

PubMed Central

Stringaris, Argyris; Lewis, Glyn; Maughan, Barbara

2014-01-01

Background Pathways from early-life conduct problems to young adult depression remain poorly understood. Aims To test developmental pathways from early-life conduct problems to depression at age 18. Method Data (n = 3542) came from the Avon Longitudinal Study of Parents and Children (ALSPAC). Previously derived conduct problem trajectories (ages 4-13 years) were used to examine associations with depression from ages 10 to 18 years, and the role of early childhood factors as potential confounders. Results Over 43% of young adults with depression in the ALSPAC cohort had a history of child or adolescent conduct problems, yielding a population attributable fraction of 0.15 (95% CI 0.08-0.22). The association between conduct problems and depression at age 18 was considerable even after adjusting for prior depression (odds ratio 1.55, 95% CI 1.24-1.94). Early-onset persistent conduct problems carried the highest risk for later depression. Irritability characterised depression for those with a history of conduct problems. Conclusions Early-life conduct problems are robustly associated with later depressive disorder and may be useful targets for early intervention. PMID:24764545

Parenting stress and child behavior problems among clinic-referred youth: cross-cultural differences across the US and Korea.

PubMed

Chung, Kyong-Mee; Ebesutani, Chad; Bang, Hye Min; Kim, Joohee; Chorpita, Bruce F; Weisz, John R; Suh, Dongsoo; Byun, Heejung

2013-06-01

Due to increased multiculturalism in the US and abroad, there is a need for increased understanding of the different ways in which parenting stress is related to child problems across cultures. In the present study, we investigated (a) differences in reported parenting stress and childhood problem behaviors across a Korean (n = 71) and US (n = 71) sample, as well as (b) differences in the ways in which parenting stress and childhood problems were related across Korean and US children based on mothers' reports. Results revealed that Korean mothers reported significantly higher parenting stress yet significantly lower childhood problem behaviors compared to US mothers. In addition, mother-based reports of child problems were significantly associated with parenting stress in the US sample, but not in the Korean sample. Clinical implications and culturally-relevant issues relevant to these findings are addressed, including a potential under-reporting bias of child problems among Asian parents.

Parent Psychological Functioning and Communication Predict Externalizing Behavior Problems After Pediatric Traumatic Brain Injury

PubMed Central

Raj, Stacey P.; Cassedy, Amy; Taylor, H. Gerry; Stancin, Terry; Brown, Tanya M.; Kirkwood, Michael W.

2014-01-01

Objective Adolescents sustaining traumatic brain injury (TBI) show increased prevalence of behavior problems. This study investigated the associations of parent mental health, family functioning, and parent–adolescent interaction with adolescent externalizing behavior problems in the initial months after TBI, and examined whether injury severity moderated these associations. Methods 117 parent–adolescent dyads completed measures of family functioning, adolescent behavior, and parent mental health an average of 108 days post-TBI. Dyads also engaged in a 10-min video-recorded problem-solving activity coded for parent behavior and tone of interaction. Results Overall, higher ratings of effective parent communication were associated with fewer externalizing behavior problems, whereas poorer caregiver psychological functioning was associated with greater adolescent externalizing behaviors. Results failed to reveal moderating effects of TBI severity on the relationship between socio-environmental factors and behavior problems. Conclusions Interventions targeting parent communication and/or improving caregiver psychological health may ameliorate potential externalizing behavior problems after adolescent TBI. PMID:24065551

REDUCING AMBIGUITY IN THE FUNCTIONAL ASSESSMENT OF PROBLEM BEHAVIOR

PubMed Central

Rooker, Griffin W.; DeLeon, Iser G.; Borrero, Carrie S. W.; Frank-Crawford, Michelle A.; Roscoe, Eileen M.

2015-01-01

Severe problem behavior (e.g., self-injury and aggression) remains among the most serious challenges for the habilitation of persons with intellectual disabilities and is a significant obstacle to community integration. The current standard of behavior analytic treatment for problem behavior in this population consists of a functional assessment and treatment model. Within that model, the first step is to assess the behavior–environment relations that give rise to and maintain problem behavior, a functional behavioral assessment. Conventional methods of assessing behavioral function include indirect, descriptive, and experimental assessments of problem behavior. Clinical investigators have produced a rich literature demonstrating the relative effectiveness for each method, but in clinical practice, each can produce ambiguous or difficult-to-interpret outcomes that may impede treatment development. This paper outlines potential sources of variability in assessment outcomes and then reviews the evidence on strategies for avoiding ambiguous outcomes and/or clarifying initially ambiguous results. The end result for each assessment method is a set of best practice guidelines, given the available evidence, for conducting the initial assessment. PMID:26236145

Household economic resources, labour-market advantage and health problems - a study on causal relationships using prospective register data.

PubMed

Aittomäki, Akseli; Martikainen, Pekka; Laaksonen, Mikko; Lahelma, Eero; Rahkonen, Ossi

2012-10-01

Our aim was to find out whether the associations between health and both individual and household economic position reflected a causal effect on health of household affluence and consumption potential. We attempted to separate this effect from health-selection effects, in other words the potential effect of health on economic position, and from various effects related to occupational position and prestige that might correlate with the economic indicators. We made a distinction between individual labour-market advantage and household economic resources in order to reflect these theoretical definitions. Our aim was to test and compare two hypotheses: 1) low household economic resources lead to an increase in health problems later on, and 2) health problems are disadvantageous on the labour market, and consequently decrease the level of economic resources. We used prospective register data obtained from the databases of Statistics Finland and constituting an 11-per-cent random sample of the Finnish population in 1993-2006. Health problems were measured in terms of sickness allowance paid by the Finnish Social Insurance Institution, household economic resources in terms of household-equivalent disposable income and taxable wealth, and labour-market advantage in terms of individual taxable income and months of unemployment. We used structural equation models (n = 211,639) to examine the hypothesised causal pathways. Low household economic resources predicted future health problems, and health problems predicted future deterioration in labour-market advantage. The effect of economic resources on health problems was somewhat stronger. These results suggest that accumulated exposure to low economic resources leads to increasing health problems, and that this causal mechanism is a more significant source of persistent health inequalities than health problems that bring about a permanent decrease in economic resources. Copyright © 2012 Elsevier Ltd. All rights reserved.

The current state of drug discovery and a potential role for NMR metabolomics.

PubMed

Powers, Robert

2014-07-24

The pharmaceutical industry has significantly contributed to improving human health. Drugs have been attributed to both increasing life expectancy and decreasing health care costs. Unfortunately, there has been a recent decline in the creativity and productivity of the pharmaceutical industry. This is a complex issue with many contributing factors resulting from the numerous mergers, increase in out-sourcing, and the heavy dependency on high-throughput screening (HTS). While a simple solution to such a complex problem is unrealistic and highly unlikely, the inclusion of metabolomics as a routine component of the drug discovery process may provide some solutions to these problems. Specifically, as the binding affinity of a chemical lead is evolved during the iterative structure-based drug design process, metabolomics can provide feedback on the selectivity and the in vivo mechanism of action. Similarly, metabolomics can be used to evaluate and validate HTS leads. In effect, metabolomics can be used to eliminate compounds with potential efficacy and side effect problems while prioritizing well-behaved leads with druglike characteristics.

An environmental approach for used oil management in Asian cities: a Bangkok' s experience.

PubMed

Leong, Shing Tet; Laortanakul, Preecha

2003-11-01

This paper addresses increasing concern about the pollution threat of used oil being illegally dumped and the impact of oil on air pollution and freshwater ecosystems in Asian countries. Used oil is a very serious waste management problem. These results call for management action such as maximising the collection and recovery of used oil. The Thai government recognizes the need to recycle used oil and has been active in encouraging programs to accomplish this goal. Thus unless new approaches and incentives are developed, used oil generation may become an increasing serious problem to our environment. The purpose of this study is to examine the technical and economic feasibility, of recycling used oils. In addition, this paper briefly discusses the problems to be overcome and outlines potential mechanisms for providing the necessary disposal controls in order to maximize the protection to public health and environmental quality from potential hazards posed by used lube oil disposal.

Evaluation of a BCMA’s Electronic Medication Administration Record

PubMed Central

Staggers, Nancy; Iribarren, Sarah; Guo, Jia-Wen; Weir, Charlene

2015-01-01

Barcode medication administration (BCMA) systems can reduce medication errors, but sociotechnical issues are quite common. Although crucial to nurses’ work, few usability evaluations are available for electronic medication administration record screens (eMARs). The purpose of this research was to identify current usability problems in the VA’s eMAR/BCMA system and explore how these might impact nurses’ situation awareness. Three expert evaluators used 10 tasks/elements, heuristic evaluation techniques and explored potential impacts using a situation awareness perspective. The results yielded 99 usability problems categorized into 440 heuristic violations with the largest volume in the category of Match with the Real World. Fifteen usability issues were rated as catastrophic with the Administer/Chart medications task having the most. Situational awareness was impacted at all levels, especially at Level 2, Comprehension. Usability problems point to important areas for improvement because these issues have the potential to impact nurses’ situation awareness, “at a glance” information, nurse productivity and patient safety. PMID:25601936

Enhancements on the Convex Programming Based Powered Descent Guidance Algorithm for Mars Landing

NASA Technical Reports Server (NTRS)

Acikmese, Behcet; Blackmore, Lars; Scharf, Daniel P.; Wolf, Aron

2008-01-01

In this paper, we present enhancements on the powered descent guidance algorithm developed for Mars pinpoint landing. The guidance algorithm solves the powered descent minimum fuel trajectory optimization problem via a direct numerical method. Our main contribution is to formulate the trajectory optimization problem, which has nonconvex control constraints, as a finite dimensional convex optimization problem, specifically as a finite dimensional second order cone programming (SOCP) problem. SOCP is a subclass of convex programming, and there are efficient SOCP solvers with deterministic convergence properties. Hence, the resulting guidance algorithm can potentially be implemented onboard a spacecraft for real-time applications. Particularly, this paper discusses the algorithmic improvements obtained by: (i) Using an efficient approach to choose the optimal time-of-flight; (ii) Using a computationally inexpensive way to detect the feasibility/ infeasibility of the problem due to the thrust-to-weight constraint; (iii) Incorporating the rotation rate of the planet into the problem formulation; (iv) Developing additional constraints on the position and velocity to guarantee no-subsurface flight between the time samples of the temporal discretization; (v) Developing a fuel-limited targeting algorithm; (vi) Initial result on developing an onboard table lookup method to obtain almost fuel optimal solutions in real-time.

Childhood Conduct Problems and Young Adult Outcomes Among Women with Childhood ADHD

PubMed Central

Owens, Elizabeth B.; Hinshaw, Stephen P.

2015-01-01

We tested whether conduct problems predicted young adult functioning and psychiatric symptoms among women diagnosed with ADHD during childhood, in the context of three potential adolescent mediators: internalizing problems, peer rejection, and school failure and disciplinary problems. We controlled for childhood ADHD severity, IQ, and demographic factors, and in the mediational tests, for adolescent conduct problems. Data emanated from 140 participants in the Berkeley Girls with ADHD Longitudinal Study. We used bootstrapping methods to assess indirect effects (mediators). Both childhood (F1,118 change = 9.00, p = .003, R2 change = .069) and adolescent (F1,109 change = 10.41, p = .002, R2 change = .083) conduct problems were associated with worse overall functioning during young adulthood, controlling for initial ADHD severity, child IQ, and demographics. Results were similar when predicting psychiatric symptoms. Adolescent school failure and disciplinary problems mediated the relations between childhood conduct problems and both young-adult functioning and externalizing problems; adolescent internalizing problems and peer conflict mediated the relation between childhood conduct problems and young-adult internalizing problems. As is true for boys, childhood and adolescent conduct problems are associated with poor adult outcomes among girls with ADHD, with school failure and disciplinary problems, internalizing problems, and peer conflict functioning as mediators of these relations. PMID:26854507

Semantic Web Services Challenge, Results from the First Year. Series: Semantic Web And Beyond, Volume 8.

NASA Astrophysics Data System (ADS)

Petrie, C.; Margaria, T.; Lausen, H.; Zaremba, M.

Explores trade-offs among existing approaches. Reveals strengths and weaknesses of proposed approaches, as well as which aspects of the problem are not yet covered. Introduces software engineering approach to evaluating semantic web services. Service-Oriented Computing is one of the most promising software engineering trends because of the potential to reduce the programming effort for future distributed industrial systems. However, only a small part of this potential rests on the standardization of tools offered by the web services stack. The larger part of this potential rests upon the development of sufficient semantics to automate service orchestration. Currently there are many different approaches to semantic web service descriptions and many frameworks built around them. A common understanding, evaluation scheme, and test bed to compare and classify these frameworks in terms of their capabilities and shortcomings, is necessary to make progress in developing the full potential of Service-Oriented Computing. The Semantic Web Services Challenge is an open source initiative that provides a public evaluation and certification of multiple frameworks on common industrially-relevant problem sets. This edited volume reports on the first results in developing common understanding of the various technologies intended to facilitate the automation of mediation, choreography and discovery for Web Services using semantic annotations. Semantic Web Services Challenge: Results from the First Year is designed for a professional audience composed of practitioners and researchers in industry. Professionals can use this book to evaluate SWS technology for their potential practical use. The book is also suitable for advanced-level students in computer science.

Non linear predictive control of a LEGO mobile robot

NASA Astrophysics Data System (ADS)

Merabti, H.; Bouchemal, B.; Belarbi, K.; Boucherma, D.; Amouri, A.

2014-10-01

Metaheuristics are general purpose heuristics which have shown a great potential for the solution of difficult optimization problems. In this work, we apply the meta heuristic, namely particle swarm optimization, PSO, for the solution of the optimization problem arising in NLMPC. This algorithm is easy to code and may be considered as alternatives for the more classical solution procedures. The PSO- NLMPC is applied to control a mobile robot for the tracking trajectory and obstacles avoidance. Experimental results show the strength of this approach.

[Risk of long-lasting negative cognitive consequences after electroconvulsive therapy].

PubMed

Svendsen, Anne Marie; Miskowiak, Kamilla; Vinberg, Maj

2013-10-28

This case study describes a patient who had a unipolar depression and experienced long-lasting cognitive problems after electroconvulsive therapy (ECT). Neuropsychological testing revealed lower scores on measures of learning, memory and sustained attention. These results stress the importance of informing patients who have ECT of the potential cognitive consequences of this treatment as it may influence the patients' functional capabilities. Prospective studies are needed since we do not have sufficient knowledge regarding the 3-5% of these patients who experience sustained cognitive problems.

Expanding the Department of Defense’s Role in Cyber Civil Support

DTIC Science & Technology

2011-06-17

vulnerability of this very crucial domain. They include the Y2K problem, the Estonia cyber-attacks in 2007, and the role of cyber in the Russian-Georgia...cyber security vulnerabilities associated with critical infrastructure. The Year 2000 Challenge The Year 2000 ( Y2K ) problem was the result of...and microprocessors failed to make the correct transition from 1999 to 2000.19 One of the most critical concerns with Y2K was the potential cascading

An analytic solution of the stochastic storage problem applicable to soil water

USGS Publications Warehouse

Milly, P.C.D.

1993-01-01

The accumulation of soil water during rainfall events and the subsequent depletion of soil water by evaporation between storms can be described, to first order, by simple accounting models. When the alternating supplies (precipitation) and demands (potential evaporation) are viewed as random variables, it follows that soil-water storage, evaporation, and runoff are also random variables. If the forcing (supply and demand) processes are stationary for a sufficiently long period of time, an asymptotic regime should eventually be reached where the probability distribution functions of storage, evaporation, and runoff are stationary and uniquely determined by the distribution functions of the forcing. Under the assumptions that the potential evaporation rate is constant, storm arrivals are Poisson-distributed, rainfall is instantaneous, and storm depth follows an exponential distribution, it is possible to derive the asymptotic distributions of storage, evaporation, and runoff analytically for a simple balance model. A particular result is that the fraction of rainfall converted to runoff is given by (1 - R−1)/(eα(1−R−1) − R−1), in which R is the ratio of mean potential evaporation to mean rainfall and a is the ratio of soil water-holding capacity to mean storm depth. The problem considered here is analogous to the well-known problem of storage in a reservoir behind a dam, for which the present work offers a new solution for reservoirs of finite capacity. A simple application of the results of this analysis suggests that random, intraseasonal fluctuations of precipitation cannot by themselves explain the observed dependence of the annual water balance on annual totals of precipitation and potential evaporation.

[Internet gambling: what are the risks?].

PubMed

Bonnaire, C

2012-02-01

Actually, there are many different and varied new ways to take part in gambling activities such as gambling via the Internet, mobile phone and interactive television. Among these media, the rise in Internet gambling activity has been very rapid. Nevertheless, few empirical studies have been carried out on the psychosocial effects of Internet gambling. While there is no conclusive evidence that Internet gambling is more likely than other gambling media to cause problem gambling, there are a number of factors that make online activities like Internet gambling potentially seductive and/or addictive. Such factors include anonymity, convenience, escape, dissociation/immersion, accessibility, event frequency, interactivity, disinhibition, simulation, and asociability. It would also appear that virtual environments have the potential to provide short-term comfort, excitement and/or distraction. The introduction of the Internet to gambling activities changes some of the fundamental situational and structural characteristics. The major change is that gambling activities are bought into the home and workplace environment. Thus, Internet gambling can become an in-house or work activity. One of the major concerns relating to those changes and the increase in gambling opportunities is the potential rise in the number of problem and pathological gamblers. Addictions always result from an interaction and interplay between many factors but in the case of gambling, it could be argued that technology and technological advance can themselves be an important contributory factor as we saw in examining the salient factors in Internet gambling. It is difficult to determine the prevalence of online (problem or not) gamblers, as it is obviously a figure that changes and has changed relatively quickly over the past decade. Nevertheless, the rate of Internet gambling is increasing and some recent studies using self-selected samples suggest, for example, that the prevalence of problem gambling among student Internet gamblers is relatively high for students who gamble on the Internet in general. Some recent studies have focused on the type of online games. For example, one specific form of online gambling online poker, is one of the fastest growing forms of online gambling. It appears that problem online poker players are more likely to swap genders when playing online, and play more frequently for longer periods of time. Thus, problem gamblers may be losing time but winning money. This result has a big implication for problem gambling criteria. Indeed, some data suggest that online poker may be producing a new type of problem gambler where the main negative consequence is loss of time (rather than loss of money). All these findings underline the need for better Internet gambling legislation. Indeed, the potential for excessive gambling and the lack of safeguards for vulnerable populations (e.g. adolescents and problem gamblers) raise the need for developing social responsibility tools. Harm-minimisation strategies are fundamental to facilitate gambling in a responsible manner, that is, to promote gambling within a player's means so they do not spent excessive time or money gambling, which cause the individual problems. Some research, but still few, examines the efficacy of responsible gambling strategies like pop-up messages. Copyright © 2011 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

The evaluation of the National Long Term Care Demonstration. 2. Estimation methodology.

PubMed Central

Brown, R S

1988-01-01

Channeling effects were estimated by comparing the post-application experience of the treatment and control groups using multiple regression. A variety of potential threats to the validity of the results, including sample composition issues, data issues, and estimation issues, were identified and assessed. Of all the potential problems examined, the only one determined to be likely to cause widespread distortion of program impact estimates was noncomparability of the baseline data. To avoid this distortion, baseline variables judged to be noncomparably measured were excluded from use as control variables in the regression equation. (Where they existed, screen counterparts to these noncomparable baseline variables were used as substitutes.) All of the other potential problems with the sample, data, or regression estimation approach were found to have little or no actual effect on impact estimates or their interpretation. Broad implementation of special procedures, therefore, was not necessary. The study did find that, because of the frequent use of proxy respondents, the estimated effects of channeling on clients' well-being actually may reflect impacts on the well-being of the informal caregiver rather than the client. This and other isolated cases in which there was some evidence of a potential problem for specific outcome variables were identified and examined in detail in technical reports dealing with those outcomes. Where appropriate, alternative estimates were presented. PMID:3130329

Socioeconomic status and child mental health: the role of parental emotional well-being and parenting practices.

PubMed

Bøe, Tormod; Sivertsen, Børge; Heiervang, Einar; Goodman, Robert; Lundervold, Astri J; Hysing, Mari

2014-01-01

This study examined the role of parental emotional well-being and parenting practices as mediators of the association between familial socioeconomic status (SES) and child mental health problems. The sample included 2,043 5th-7th graders (50.7 % female) participating in the second wave of the Bergen Child Study. Children completed the Strengths and Difficulties Questionnaire, parents reported family economy and education level, emotional well-being (measured with the Everyday Feelings Questionnaire), and the use of negative disciplinary and affirmative parenting practices (measured using the Family Life Questionnaire). Path analyses were conducted to examine the associations between SES and externalizing and internalizing problems. Results supported a model where family economy was associated with externalizing problems through parental emotional well-being and parenting practices, whereas maternal education level was associated with externalizing problems through negative discipline. The direct association between paternal education level and externalizing problems was not mediated by parenting. For internalizing problems, we found both direct associations with family economy and indirect associations with family economy through parental emotional well-being and parenting. The results suggest that parental emotional well-being and parenting practices are two potential mechanisms through which low socioeconomic status is associated with child mental health problems.

Discrimination and alcohol-related problems among college students: a prospective examination of mediating effects.

PubMed

Hatzenbuehler, Mark L; Corbin, William R; Fromme, Kim

2011-06-01

Discrimination is a risk factor for health-risk behaviors, including alcohol abuse. Far less is known about the mechanisms through which discrimination leads to alcohol-related problems, particularly during high-risk developmental periods such as young adulthood. The present study tested a mediation model using prospective data from a large, diverse sample of 1539 college students. This model hypothesized that discrimination would be associated with established cognitive (positive alcohol expectancies) and affective (negative affect and coping motives) risk factors for alcohol-related problems, which would account for the prospective association between discrimination and alcohol problems. Structural equation modeling indicated that discrimination was associated cross-sectionally with negative affect and more coping motives for drinking, but not with greater alcohol expectancies. Coping motives mediated the prospective relationship between discrimination and alcohol-related problems. Additionally, results indicated significant indirect effects from discrimination to alcohol-related problems through negative affect and coping motives. These associations were evident for multiple groups confronting status-based discrimination, including women, racial/ethnic minorities, and lesbian/gay/bisexual individuals. This study identified potential affective mechanisms linking discrimination to alcohol-related problems. Results suggest several avenues for prevention and intervention efforts with individuals from socially disadvantaged groups. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Potential interference to GPS from UWB transmitters : phase II test results

DOT National Transportation Integrated Search

2001-03-16

In 1999, the U.S. Department of Transportation (DOT") approached Stanford University to research the compatibility of UWB and GPS and to conduct tests to help quantify any interference problems. This is the second report from Stanford to the Departme...

Treatment Effects for Common Outcomes of Child Sexual Abuse: A Current Meta-Analysis

PubMed Central

Trask, Emily V.; Walsh, Kate; DiLillo, David

2010-01-01

The present meta-analysis examined the effects of psychosocial treatments at reducing deleterious outcomes of sexual abuse. The meta-analysis included a total of 35 published and unpublished studies written in English, focusing on youth under the age of 18, and evaluating the effectiveness of treatments for the most common negative outcomes of sexual abuse: PTSD symptoms, externalizing problems, and internalizing problems. Results revealed medium effect sizes for PTSD symptoms, externalizing problems, and internalizing problems following treatment for sexual abuse. This study also examined the potential moderating effects of treatment (e.g., modality, duration, inclusion of caregiver) and participant (e.g., age, gender, ethnicity) characteristics. Results indicated that longer interventions were associated with greater treatment gains while group and individual treatments were equally effective. These findings shed new light on treatment effectiveness and provide useful information regarding the conditions under which treatment may be most effective. Future directions for research in this area are discussed. PMID:21603060

Sequential bearings-only-tracking initiation with particle filtering method.

PubMed

Liu, Bin; Hao, Chengpeng

2013-01-01

The tracking initiation problem is examined in the context of autonomous bearings-only-tracking (BOT) of a single appearing/disappearing target in the presence of clutter measurements. In general, this problem suffers from a combinatorial explosion in the number of potential tracks resulted from the uncertainty in the linkage between the target and the measurement (a.k.a the data association problem). In addition, the nonlinear measurements lead to a non-Gaussian posterior probability density function (pdf) in the optimal Bayesian sequential estimation framework. The consequence of this nonlinear/non-Gaussian context is the absence of a closed-form solution. This paper models the linkage uncertainty and the nonlinear/non-Gaussian estimation problem jointly with solid Bayesian formalism. A particle filtering (PF) algorithm is derived for estimating the model's parameters in a sequential manner. Numerical results show that the proposed solution provides a significant benefit over the most commonly used methods, IPDA and IMMPDA. The posterior Cramér-Rao bounds are also involved for performance evaluation.

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

Epidural conduction device fractures and complications of retained fragments.

PubMed

Fischer, Robert

2008-02-01

During the past 3 years, the US Food and Drug Administration (FDA) has received a growing number of adverse event reports on the breakage or fracturing and retention of anesthetic conduction device tips with associated complications. Serious injuries and other problems such as spinal stenosis, nerve root compression, and subcutaneous effusion can result. Several case reports demonstrate how the problems occur; some illustrate the severity of the problem. All cases are from adverse event reports in the FDA Center for Devices and Radiological Health (CDRH) Manufacturer and User Facility Device Experience database. Frequently, in the interest of not causing patient harm, a device fragment might not be removed as long as the patient is not neurologically compromised or at risk for infection or there is little potential for migration of the fragmented piece. On many occasions, the fragments remain in patients without their knowledge. The FDA wants to raise awareness of the problem and its potential impact in creating complications, encourage the practice of informing patients of the fragmented device, and promote reporting of such incidents to CDRH via the MedWatch reporting system. Based on a search of the current literature, recommendations for prevention are suggested.

A Random Variable Approach to Nuclear Targeting and Survivability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Undem, Halvor A.

We demonstrate a common mathematical formalism for analyzing problems in nuclear survivability and targeting. This formalism, beginning with a random variable approach, can be used to interpret past efforts in nuclear-effects analysis, including targeting analysis. It can also be used to analyze new problems brought about by the post Cold War Era, such as the potential effects of yield degradation in a permanently untested nuclear stockpile. In particular, we illustrate the formalism through four natural case studies or illustrative problems, linking these to actual past data, modeling, and simulation, and suggesting future uses. In the first problem, we illustrate themore » case of a deterministically modeled weapon used against a deterministically responding target. Classic "Cookie Cutter" damage functions result. In the second problem, we illustrate, with actual target test data, the case of a deterministically modeled weapon used against a statistically responding target. This case matches many of the results of current nuclear targeting modeling and simulation tools, including the result of distance damage functions as complementary cumulative lognormal functions in the range variable. In the third problem, we illustrate the case of a statistically behaving weapon used against a deterministically responding target. In particular, we show the dependence of target damage on weapon yield for an untested nuclear stockpile experiencing yield degradation. Finally, and using actual unclassified weapon test data, we illustrate in the fourth problem the case of a statistically behaving weapon used against a statistically responding target.« less

Antisocial Traits, Distress Tolerance, and Alcohol Problems as Predictors of Intimate Partner Violence in Men Arrested for Domestic Violence.

PubMed

Brem, Meagan J; Florimbio, Autumn Rae; Elmquist, JoAnna; Shorey, Ryan C; Stuart, Gregory L

2018-01-01

Men with antisocial personality disorder (ASPD) traits are at an increased risk for consuming alcohol and perpetrating intimate partner violence (IPV). However, previous research has neglected malleable mechanisms potentially responsible for the link between ASPD traits, alcohol problems, and IPV perpetration. Efforts to improve the efficacy of batterer intervention programs (BIPs) would benefit from exploration of such malleable mechanisms. The present study is the first to examine distress tolerance as one such mechanism linking men's ASPD traits to their alcohol problems and IPV perpetration. Using a cross-sectional sample of 331 men arrested for domestic violence and court-referred to BIPs, the present study used structural equation modeling to examine pathways from men's ASPD traits to IPV perpetration directly and indirectly through distress tolerance and alcohol problems. Results supported a two-chain partial mediational model. ASPD traits were related to psychological aggression perpetration directly and indirectly via distress tolerance and alcohol problems. A second pathway emerged by which ASPD traits related to higher levels of alcohol problems, which related to psychological aggression perpetration. Controlling for psychological aggression perpetration, neither distress tolerance nor alcohol problems explained the relation between ASPD traits and physical assault perpetration. These results support and extend existing conceptual models of IPV perpetration. Findings suggest intervention efforts for IPV should target both distress tolerance and alcohol problems.

Implications of Middle School Behavior Problems for High School Graduation and Employment Outcomes of Young Adults: Estimation of a Recursive Model

PubMed Central

Karakus, Mustafa C.; Salkever, David S.; Slade, Eric P.; Ialongo, Nicholas; Stuart, Elizabeth

2013-01-01

The potentially serious adverse impacts of behavior problems during adolescence on employment outcomes in adulthood provide a key economic rationale for early intervention programs. However, the extent to which lower educational attainment accounts for the total impact of adolescent behavior problems on later employment remains unclear As an initial step in exploring this issue, we specify and estimate a recursive bivariate probit model that 1) relates middle school behavior problems to high school graduation and 2) models later employment in young adulthood as a function of these behavior problems and of high school graduation. Our model thus allows for both a direct effect of behavior problems on later employment as well as an indirect effect that operates via graduation from high school. Our empirical results, based on analysis of data from the NELS, suggest that the direct effects of externalizing behavior problems on later employment are not significant but that these problems have important indirect effects operating through high school graduation. PMID:23576834

[Investigation of problem solving skills among psychiatric patients].

PubMed

Póos, Judit; Annus, Rita; Perczel Forintos, Dóra

2008-01-01

According to our present knowledge depression and hopelessness play an important role in attempted suicide and the development of hopelessness seems to be closely associated with poor problem solving skills. In the present study we have used the internationally well-known MEPS (Means-Ends Problem Solving Test; a measure of social problem solving ability) in Hungary for the first time and combined with other tests. We intended to explore the cognitive risk factors that potentially play a role in the suicidal behavior in clinical population. In our study we compared a group of individuals who had attempted suicide to a nonsuicidal psychiatric control group and a normal control group (61 subjects in each group). Our results confirm the findings of others that psychiatric patients have difficulties in social problem solving compared to normal controls. Moreover, they generate less and poorer solutions. According to our data problem solving skills of the two clinical groups were similar. A strong positive correlation was found between poor problem solving skills, depression and hopelessness which may suggest that the development of problem solving skills could help to reduce negative mood.

An investigation into the use of the car as a mobile office.

PubMed

Eost, C; Flyte, M G

1998-10-01

In today's business environment people can no longer afford to be 'out of touch' when they are away from the office, with the result, the car has become a mobile office for many workers. The aims of this study were * to review current technology in the mobile office, * to determine problems of office working in the car, * to offer design solutions. Case studies gained an insight into working practices and problems in the car. Diaries quantified the types and amounts of work done in the car and an interview survey measured the extent of mobile office technology implemented into cars, problems relating to working in the car and some potential solutions. People do experience problems trying to do office work in their car. These problems include lack of space, lack of storage, nowhere flat to rest work on, inadequate temperature control in the car and poor communication facilities.

Management of sexual problems: the approach of mindfulness.

PubMed

Vilarinho, Sandra

2017-11-01

During the last 10 years mindfulness has been progressively integrated into protocols for the management of sexual problems. The purpose of this study is to systematize potential benefits of mindfulness in sexual well-being (considering mind, emotion, and body), and to shortly review current applications and effectiveness of mindfulness-based interventions to the treatment of sexual problems. The majority of evidence available focuses on women's sexual desire and arousal problems, although there are also preliminary findings for the effectiveness of mindfulness-based interventions in enhancing other components of the sexual response. Relationship issues, sexual pain, sexual abuse, and sexual distress have also revealed to benefit from mindfulness-based interventions. The practice of mindfulness is a promising clinical approach with encouraging results for women's sexual problems. Further empirical research with different populations and greater methodological rigour is still needed to clarify the effectiveness of mindfulness as a specific component and the mechanisms contributing to therapeutic change.

The Effect of Psychological Suzhi on Problem Behaviors in Chinese Adolescents: The Mediating Role of Subjective Social Status and Self-esteem

PubMed Central

Liu, Guangzeng; Zhang, Dajun; Pan, Yangu; Ma, Yuanxiao; Lu, Xingyue

2017-01-01

In this study, we examined subjective social status (SSS) and self-esteem as potential mediators between the association of psychological suzhi and problem behaviors in a sample of 1271 Chinese adolescents (44.5% male, grades 7–12). The results showed that SSS and self-esteem were fully mediating the relationship between psychological suzhi and problem behaviors. Moreover, the indirect effect was stronger via self-esteem than via SSS. These findings perhaps provide insight into the preliminary effect that SSS and self-esteem underlie psychological suzhi’s effect on adolescents’ problem behaviors, and also are important in helping school-teachers and administrators to develop a better understanding of problem behaviors in their schools as a pre-requisite to the development of more effective behaviors management practices from the perspective of psychological suzhi. Implications and limitations in the present study have also been discussed. PMID:28912744

Unsupervised self-care predicts conduct problems: The moderating roles of hostile aggression and gender.

PubMed

Atherton, Olivia E; Schofield, Thomas J; Sitka, Angela; Conger, Rand D; Robins, Richard W

2016-04-01

Despite widespread speculation about the detrimental effect of unsupervised self-care on adolescent outcomes, little is known about which children are particularly prone to problem behaviors when left at home without adult supervision. The present research used data from a longitudinal study of 674 Mexican-origin children residing in the United States to examine the prospective effect of unsupervised self-care on conduct problems, and the moderating roles of hostile aggression and gender. Results showed that unsupervised self-care was related to increases over time in conduct problems such as lying, stealing, and bullying. However, unsupervised self-care only led to conduct problems for boys and for children with an aggressive temperament. The main and interactive effects held for both mother-reported and observational-rated hostile aggression and after controlling for potential confounds. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Parenting and children's externalizing problems in substance-abusing families.

PubMed

Stanger, Catherine; Dumenci, Levent; Kamon, Jody; Burstein, Marcy

2004-09-01

This study tested associations in path models among positive and negative parenting and children's rule-breaking behavior, aggressive and oppositional behavior, and attention problems for families with a drug-dependent parent. A structural model tested relations between parenting and children's externalizing problems for 251 families with 399 children between the ages of 6 and 18, controlling for nonindependence of ratings at the family level. The model also tested potential moderators, including child age, gender, and ethnicity (White vs. other), and caregiver gender (families with a female substance-abusing caregiver vs. families with a male substance-abusing caregiver). Results indicated that caregiver ratings of monitoring predicted rule-breaking behavior and use of inconsistent discipline predicted ratings of all 3 externalizing syndromes, after controlling parenting and externalizing problems for the effects of the moderators and after controlling significant relations among types of parenting and types of externalizing problems.

Study to determine the IFR operational profile and problems to the general aviation pilot

NASA Technical Reports Server (NTRS)

Weislogel, S.

1983-01-01

A study of the general aviation single pilot operating under instrument flight rules (GA SPIFR) has been conducted for NASA Langley Research Center. The objectives of the study were to (1) develop a GA SPIFR operational profile, (2) identify problems experienced by the GA SPIFR pilot, and (3) identify research tasks which have the potential for eliminating or reducing the severity of the problems. To obtain the information necessary to accomplish these objectives, a mail questionnaire survey of instrument rated pilots was conducted. Complete questionnaire data is reported in NASA CR-165805, "Statistical Summary: Study to Determine the IFR Operational Profile and Problems of the General Aviation Single Pilot'-Based upon the results of the GA SPIFR survey, this final report presents the general aviation IFR single pilot operational profile, illustrates selected data analysis, examples, identifies the problems which he is experiencing, and recommends further research.

The Effect of Psychological Suzhi on Problem Behaviors in Chinese Adolescents: The Mediating Role of Subjective Social Status and Self-esteem.

PubMed

Liu, Guangzeng; Zhang, Dajun; Pan, Yangu; Ma, Yuanxiao; Lu, Xingyue

2017-01-01

In this study, we examined subjective social status (SSS) and self-esteem as potential mediators between the association of psychological suzhi and problem behaviors in a sample of 1271 Chinese adolescents (44.5% male, grades 7-12). The results showed that SSS and self-esteem were fully mediating the relationship between psychological suzhi and problem behaviors. Moreover, the indirect effect was stronger via self-esteem than via SSS. These findings perhaps provide insight into the preliminary effect that SSS and self-esteem underlie psychological suzhi 's effect on adolescents' problem behaviors, and also are important in helping school-teachers and administrators to develop a better understanding of problem behaviors in their schools as a pre-requisite to the development of more effective behaviors management practices from the perspective of psychological suzhi. Implications and limitations in the present study have also been discussed.

Solving optimization problems by the public goods game

NASA Astrophysics Data System (ADS)

Javarone, Marco Alberto

2017-09-01

We introduce a method based on the Public Goods Game for solving optimization tasks. In particular, we focus on the Traveling Salesman Problem, i.e. a NP-hard problem whose search space exponentially grows increasing the number of cities. The proposed method considers a population whose agents are provided with a random solution to the given problem. In doing so, agents interact by playing the Public Goods Game using the fitness of their solution as currency of the game. Notably, agents with better solutions provide higher contributions, while those with lower ones tend to imitate the solution of richer agents for increasing their fitness. Numerical simulations show that the proposed method allows to compute exact solutions, and suboptimal ones, in the considered search spaces. As result, beyond to propose a new heuristic for combinatorial optimization problems, our work aims to highlight the potentiality of evolutionary game theory beyond its current horizons.

Constraint-Based Local Search for Constrained Optimum Paths Problems

NASA Astrophysics Data System (ADS)

Pham, Quang Dung; Deville, Yves; van Hentenryck, Pascal

Constrained Optimum Path (COP) problems arise in many real-life applications and are ubiquitous in communication networks. They have been traditionally approached by dedicated algorithms, which are often hard to extend with side constraints and to apply widely. This paper proposes a constraint-based local search (CBLS) framework for COP applications, bringing the compositionality, reuse, and extensibility at the core of CBLS and CP systems. The modeling contribution is the ability to express compositional models for various COP applications at a high level of abstraction, while cleanly separating the model and the search procedure. The main technical contribution is a connected neighborhood based on rooted spanning trees to find high-quality solutions to COP problems. The framework, implemented in COMET, is applied to Resource Constrained Shortest Path (RCSP) problems (with and without side constraints) and to the edge-disjoint paths problem (EDP). Computational results show the potential significance of the approach.

Single-shot detection of bacterial endospores via coherent Raman spectroscopy.

PubMed

Pestov, Dmitry; Wang, Xi; Ariunbold, Gombojav O; Murawski, Robert K; Sautenkov, Vladimir A; Dogariu, Arthur; Sokolov, Alexei V; Scully, Marlan O

2008-01-15

Recent advances in coherent Raman spectroscopy hold exciting promise for many potential applications. For example, a technique, mitigating the nonresonant four-wave-mixing noise while maximizing the Raman-resonant signal, has been developed and applied to the problem of real-time detection of bacterial endospores. After a brief review of the technique essentials, we show how extensions of our earlier experimental work [Pestov D, et al. (2007) Science 316:265-268] yield single-shot identification of a small sample of Bacillus subtilis endospores (approximately 10(4) spores). The results convey the utility of the technique and its potential for "on-the-fly" detection of biohazards, such as Bacillus anthracis. The application of optimized coherent anti-Stokes Raman scattering scheme to problems requiring chemical specificity and short signal acquisition times is demonstrated.

Scintillating glasses for total absorption dual readout calorimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonvicini, V.; Driutti, A.; Cauz, D.

2012-01-01

Scintillating glasses are a potentially cheaper alternative to crystal - based calorimetry with common problems related to light collection, detection and processing. As such, their use and development are part of more extensive R&D aimed at investigating the potential of total absorption, combined with the readout (DR) technique, for hadron calorimetry. A recent series of measurements, using cosmic and particle beams from the Fermilab test beam facility and scintillating glass with the characteristics required for application of the DR technique, serve to illustrate the problems addressed and the progress achieved by this R&D. Alternative solutions for light collection (conventional andmore » silicon photomultipliers) and signal processing are compared, the separate contributions of scintillation and Cherenkov processes to the signal are evaluated and results are compared to simulation.« less

Classical and quantum dynamics in an inverse square potential

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guillaumín-España, Elisa, E-mail: ege@correo.azc.uam.mx; Núñez-Yépez, H. N., E-mail: nyhn@xanum.uam.mx; Salas-Brito, A. L., E-mail: asb@correo.azc.uam.mx

2014-10-15

The classical motion of a particle in a 3D inverse square potential with negative energy, E, is shown to be geodesic, i.e., equivalent to the particle's free motion on a non-compact phase space manifold irrespective of the sign of the coupling constant. We thus establish that all its classical orbits with E < 0 are unbounded. To analyse the corresponding quantum problem, the Schrödinger equation is solved in momentum space. No discrete energy levels exist in the unrenormalized case and the system shows a complete “fall-to-the-center” with an energy spectrum unbounded by below. Such behavior corresponds to the non-existence ofmore » bound classical orbits. The symmetry of the problem is SO(3) × SO(2, 1) corroborating previously obtained results.« less

General Potential Theory of Arbitrary Wing Sections

NASA Technical Reports Server (NTRS)

Theodorsen, T.; Garrick, I. E.

1979-01-01

The problem of determining the two dimensional potential flow around wing sections of any shape is examined. The problem is condensed into the compact form of an integral equation capable of yielding numerical solutions by a direct process. An attempt is made to analyze and coordinate the results of earlier studies relating to properties of wing sections. The existing approximate theory of thin wing sections and the Joukowski theory with its numerous generalizations are reduced to special cases of the general theory of arbitrary sections, permitting a clearer perspective of the entire field. The method which permits the determination of the velocity at any point of an arbitrary section and the associated lift and moments is described. The method is also discussed in terms for developing new shapes of preassigned aerodynamical properties.

Theory and practice in the electrometric determination of pH in precipitation

NASA Astrophysics Data System (ADS)

Brennan, Carla Jo; Peden, Mark E.

Basic theory and laboratory investigations have been applied to the electrometric determination of pH in precipitation samples in an effort to improve the reliability of the results obtained from these low ionic strength samples. The theoretical problems inherent in the measurement of pH in rain have been examined using natural precipitation samples with varying ionic strengths and pH values. The importance of electrode design and construction has been stressed. The proper choice of electrode can minimize or eliminate problems arising from residual liquid junction potentials, streaming potentials and temperature differences. Reliable pH measurements can be made in precipitation samples using commercially available calibration buffers providing low ionic strength quality control solutions are routinely used to verify electrode and meter performance.

The Potential of Automated Corrective Feedback to Remediate Cohesion Problems in Advanced Students' Writing

ERIC Educational Resources Information Center

Strobl, Carola

2017-01-01

This study explores the potential of a feedback environment using simple string-based pattern matching technology for the provision of automated corrective feedback on cohesion problems. Thirty-eight high-frequent problems, including non-target like use of connectives and co-references were addressed providing both direct and indirect feedback.…

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.

PRODUCTS OF INCOMPLETE COMBUSTION FROM DIRECT BURNING OF PENTACHLOROPHENOL-TREATED WOOD WASTES

EPA Science Inventory

The report gives results of a study to identify potential air pollution problems from the combustion of waste wood treated with pentachlorophenol preservative for energy production in a boiler. The study emphasized the characterization of the products of incomplete combustion (PI...

Remote-Sensing Practice and Potential

DTIC Science & Technology

1974-05-01

Six essential processes that must be accomplished if use of a remote - sensing system is to result in useful information are defined as problem...to be useful in remote - sensing projects are described. An overview of the current state-of-the-art of remote sensing is presented.

Space languages

NASA Technical Reports Server (NTRS)

Hays, Dan

1987-01-01

Applications of linguistic principles to potential problems of human and machine communication in space settings are discussed. Variations in language among speakers of different backgrounds and change in language forms resulting from new experiences or reduced contact with other groups need to be considered in the design of intelligent machine systems.

Can Food be Addictive? Public Health and Policy Implications

PubMed Central

Gearhardt, Ashley N.; Grilo, Carlos M.; DiLeone, Ralph J.; Brownell, Kelly D.; Potenza, Marc N.

2011-01-01

Aims Data suggest that hyperpalatable foods may be capable of triggering an addictive process. Although the addictive potential of foods continues to be debated, important lessons learned in reducing the health and economic consequences of drug addiction may be especially useful in combating food-related problems. Methods In the current paper, we review the potential application of policy and public health approaches that have been effective in reducing the impact of addictive substances to food-related problems. Results Corporate responsibility, public health approaches, environmental change, and global efforts all warrant strong consideration in reducing obesity and diet-related disease. Conclusions Although there exist important differences between foods and addictive drugs, ignoring analogous neural and behavioral effects of foods and drugs of abuse may result in increased food-related disease and associated social and economic burdens. Public health interventions that have been effective in reducing the impact of addictive drugs may have a role in targeting obesity and related diseases. PMID:21635588

Preliminary Study of 2-D Time Domain Electromagnetic (TDEM) Modeling to Analyze Subsurface Resistivity Distribution and its Application to the Geothermal Systems

NASA Astrophysics Data System (ADS)

Aji Hapsoro, Cahyo; Purqon, Acep; Srigutomo, Wahyu

2017-07-01

2-D Time Domain Electromagnetic (TDEM) has been successfully conducted to illustrate the value of Electric field distribution under the Earth surface. Electric field compared by magnetic field is used to analyze resistivity and resistivity is one of physical properties which very important to determine the reservoir potential area of geothermal systems as one of renewable energy. In this modeling we used Time Domain Electromagnetic method because it can solve EM field interaction problem with complex geometry and to analyze transient problems. TDEM methods used to model the value of electric and magnetic fields as a function of the time combined with the function of distance and depth. The result of this modeling is Electric field intensity value which is capable to describe the structure of the Earth’s subsurface. The result of this modeling can be applied to describe the Earths subsurface resistivity values to determine the reservoir potential of geothermal systems.

Brain potentials during mental arithmetic: effects of extensive practice and problem difficulty.

PubMed

Pauli, P; Lutzenberger, W; Rau, H; Birbaumer, N; Rickard, T C; Yaroush, R A; Bourne, L E

1994-07-01

Recent behavioral investigations indicate that the processes underlying mental arithmetic change systematically with practice from deliberate, conscious calculation to automatic, direct retrieval of answers from memory [Bourne, L.E.Jr. and Rickard, T.C., Mental calculation: The development of a cognitive skill, Paper presented at the Interamerican Congress of Psychology, San Jose, Costa Rica, 1991: Psychol. Rev., 95 (1988) 492-527]. Results reviewed by Moscovitch and Winocur [In: The handbook of aging and cognition, Erlbaum, Hillsdale, NJ, 1992, pp. 315-372] suggest that consciously controlled processes are more dependent on frontal lobe function than are automatic processes. It is appropriate, therefore to determine whether transitions in the locus of primary brain activity occur with practice on mental calculation. In this experiment, we examine the relationship between characteristics of event-related brain potentials (ERPs) and mental arithmetic. Single-digit mental multiplication problems varying in difficulty (problem size) were used, and subjects were trained on these problems for four sessions. Problem-size and practice effects were reliably found in behavioral measures (RT). The ERP was characterized by a pronounced late positivity after task presentation followed by a slow wave, and a negativity during response indication. These components responded differentially to the practice and problem-size manipulations. Practice mainly affected topography of the amplitude of positivity and offset latency of slow wave, and problem-size mainly offset latency of slow wave and pre-response negativity. Fronto-central positivity diminished from session to session, and the focus of positivity centered finally at centro-parietal regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Shame mediates the relationship between depression and addictive behaviours.

PubMed

Bilevicius, Elena; Single, Alanna; Bristow, Lindsay A; Foot, Melody; Ellery, Michael; Keough, Matthew T; Johnson, Edward A

2018-07-01

Alcohol and gambling problems are common in young adults. Self-medication theory states that young adults with depression drink and/or gamble to escape negative emotions. Research shows that depression is a risk factor for drinking/gambling problems, but more work is needed to examine mediators underlying these associations. One potential mediator is shame. Shame is a self-directed emotion that follows a negative life event and is characterized by intense feelings of inferiority, worthlessness, and embarrassment. Depressed individuals are especially susceptible to shame (and associated emotions). Shame has also been implicated in risk for addiction. Accordingly, we predicted that elevated shame would explain why depression is associated with both alcohol and gambling problems. A longitudinal design was used to examine this hypothesis. Undergraduates (N = 210) completed self-reports of depression at baseline (Time 1) and then completed self-reports of shame, alcohol misuse, gambling problems one month later (Time 2). Results showed that individuals with elevated depression at Time 1 endorsed high levels of shame at Time 2, which in turn predicted more gambling (β = .038, 95% CI [.010, .087]) and alcohol problems (β = .249, 95% CI [.123, .435]) at Time 2. We found that increased levels of shame explained the effects of depression on problem drinking and gambling. Study findings improve our understanding of the depressive pathway to addiction by providing evidence for shame as a potential mechanism of this pathway. Reducing shame can be a target of clinical interventions for young adults with depression and alcohol/gambling problems. Copyright © 2018 Elsevier Ltd. All rights reserved.

Large biases in regression-based constituent flux estimates: causes and diagnostic tools

USGS Publications Warehouse

Hirsch, Robert M.

2014-01-01

It has been documented in the literature that, in some cases, widely used regression-based models can produce severely biased estimates of long-term mean river fluxes of various constituents. These models, estimated using sample values of concentration, discharge, and date, are used to compute estimated fluxes for a multiyear period at a daily time step. This study compares results of the LOADEST seven-parameter model, LOADEST five-parameter model, and the Weighted Regressions on Time, Discharge, and Season (WRTDS) model using subsampling of six very large datasets to better understand this bias problem. This analysis considers sample datasets for dissolved nitrate and total phosphorus. The results show that LOADEST-7 and LOADEST-5, although they often produce very nearly unbiased results, can produce highly biased results. This study identifies three conditions that can give rise to these severe biases: (1) lack of fit of the log of concentration vs. log discharge relationship, (2) substantial differences in the shape of this relationship across seasons, and (3) severely heteroscedastic residuals. The WRTDS model is more resistant to the bias problem than the LOADEST models but is not immune to them. Understanding the causes of the bias problem is crucial to selecting an appropriate method for flux computations. Diagnostic tools for identifying the potential for bias problems are introduced, and strategies for resolving bias problems are described.

Investigating a hybrid perturbation-Galerkin technique using computer algebra

NASA Technical Reports Server (NTRS)

Andersen, Carl M.; Geer, James F.

1988-01-01

A two-step hybrid perturbation-Galerkin method is presented for the solution of a variety of differential equations type problems which involve a scalar parameter. The resulting (approximate) solution has the form of a sum where each term consists of the product of two functions. The first function is a function of the independent field variable(s) x, and the second is a function of the parameter lambda. In step one the functions of x are determined by forming a perturbation expansion in lambda. In step two the functions of lambda are determined through the use of the classical Bubnov-Gelerkin method. The resulting hybrid method has the potential of overcoming some of the drawbacks of the perturbation and Bubnov-Galerkin methods applied separately, while combining some of the good features of each. In particular, the results can be useful well beyond the radius of convergence associated with the perturbation expansion. The hybrid method is applied with the aid of computer algebra to a simple two-point boundary value problem where the radius of convergence is finite and to a quantum eigenvalue problem where the radius of convergence is zero. For both problems the hybrid method apparently converges for an infinite range of the parameter lambda. The results obtained from the hybrid method are compared with approximate solutions obtained by other methods, and the applicability of the hybrid method to broader problem areas is discussed.

Poverty, food insecurity, and the behavior for childhood internalizing and externalizing disorders.

PubMed

Slopen, Natalie; Fitzmaurice, Garrett; Williams, David R; Gilman, Stephen E

2010-05-01

This study investigated the associations of poverty and food insecurity over a 2-year period with internalizing and externalizing problems in a large, community-based sample. A total of 2,810 children were interviewed between ages 4 and 14 years at baseline, and between ages 5 and 16 years at follow-up. Primary caregivers reported on household income, food insecurity, and were administered the Child Behavior Checklist, from which we derived indicators of clinically significant internalizing and externalizing problems. Prevalence ratios for the associations of poverty and food insecurity with behavior problems were estimated. At baseline, internalizing and externalizing problems were significantly more prevalent among children who lived in poor households than in nonpoor households, and among children who lived in food insecure households than in food-secure households. In adjusted analyses, children from homes that were persistently food insecure were 1.47 (95% CI = 1.12 to 1.94) times more likely to have internalizing problems and 2.01 (95% CI = 1.21 to 3.35) times more likely to have externalizing problems compared with children from households that were never food insecure. Children from homes that moved from food secure to insecure were 1.78 (95% CI = 1.07 to 2.94) times more likely to have externalizing problems at follow-up. Persistent food insecurity is associated with internalizing and externalizing problems, even after adjusting for sustained poverty and other potential confounders. These results implicate food insecurity as a novel risk factor for child mental well-being; if causal, this represents an important factor in the etiology of child psychopathology, and potentially a new avenue for prevention.

Problem-Solving After Traumatic Brain Injury in Adolescence: Associations With Functional Outcomes

PubMed Central

Wade, Shari L.; Cassedy, Amy E.; Fulks, Lauren E.; Taylor, H. Gerry; Stancin, Terry; Kirkwood, Michael W.; Yeates, Keith O.; Kurowski, Brad G.

2017-01-01

Objective To examine the association of problem-solving with functioning in youth with traumatic brain injury (TBI). Design Cross-sectional evaluation of pretreatment data from a randomized controlled trial. Setting Four children’s hospitals and 1 general hospital, with level 1 trauma units. Participants Youth, ages 11 to 18 years, who sustained moderate or severe TBI in the last 18 months (N=153). Main Outcome Measures Problem-solving skills were assessed using the Social Problem-Solving Inventory (SPSI) and the Dodge Social Information Processing Short Stories. Everyday functioning was assessed based on a structured clinical interview using the Child and Adolescent Functional Assessment Scale (CAFAS) and via adolescent ratings on the Youth Self Report (YSR). Correlations and multiple regression analyses were used to examine associations among measures. Results The TBI group endorsed lower levels of maladaptive problem-solving (negative problem orientation, careless/impulsive responding, and avoidant style) and lower levels of rational problem-solving, resulting in higher total problem-solving scores for the TBI group compared with a normative sample (P<.001). Dodge Social Information Processing Short Stories dimensions were correlated (r=.23–.37) with SPSI subscales in the anticipated direction. Although both maladaptive (P<.001) and adaptive (P=.006) problem-solving composites were associated with overall functioning on the CAFAS, only maladaptive problem-solving (P<.001) was related to the YSR total when outcomes were continuous. For the both CAFAS and YSR logistic models, maladaptive style was significantly associated with greater risk of impairment (P=.001). Conclusions Problem-solving after TBI differs from normative samples and is associated with functional impairments. The relation of problem-solving deficits after TBI with global functioning merits further investigation, with consideration of the potential effects of problem-solving interventions on functional outcomes. PMID:28389109

A Lifetime of Trauma: Mental Health Challenges for Higher Education in a Conflict Environment in Afghanistan

ERIC Educational Resources Information Center

Babury, Mohammed Osman; Hayward, Fred Manwarren

2013-01-01

More than 30 years of war in Afghanistan have resulted in immense policy challenges to address the resulting mental health issues. The purpose of this policy analysis is to examine the potential role of higher education in addressing the pressing mental health problems in Afghanistan's public universities and higher education institutions as a…

A parallel interaction potential approach coupled with the immersed boundary method for fully resolved simulations of deformable interfaces and membranes

NASA Astrophysics Data System (ADS)

Spandan, Vamsi; Meschini, Valentina; Ostilla-Mónico, Rodolfo; Lohse, Detlef; Querzoli, Giorgio; de Tullio, Marco D.; Verzicco, Roberto

2017-11-01

In this paper we show and discuss how the deformation dynamics of closed liquid-liquid interfaces (for example drops and bubbles) can be replicated with use of a phenomenological interaction potential model. This new approach to simulate liquid-liquid interfaces is based on the fundamental principle of minimum potential energy where the total potential energy depends on the extent of deformation of a spring network distributed on the surface of the immersed drop or bubble. Simulating liquid-liquid interfaces using this model require computing ad-hoc elastic constants which is done through a reverse-engineered approach. The results from our simulations agree very well with previous studies on the deformation of drops in standard flow configurations such as a deforming drop in a shear flow or cross flow. The interaction potential model is highly versatile, computationally efficient and can be easily incorporated into generic single phase fluid solvers to also simulate complex fluid-structure interaction problems. This is shown by simulating flow in the left ventricle of the heart with mechanical and natural mitral valves where the imposed flow, motion of ventricle and valves dynamically govern the behaviour of each other. Results from these simulations are compared with ad-hoc in-house experimental measurements. Finally, we present a simple and easy to implement parallelisation scheme, as high performance computing is unavoidable when studying large scale problems involving several thousands of simultaneously deforming bodies in highly turbulent flows.

Semiclassical anomalies of the quantum mechanical systems and their modifications for the asymptotic matching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deniz, Coskun, E-mail: coskun.deniz@ege.edu.tr

JWKB solutions to the Initial Value Problems (IVPs) of the Time Independent Schrodinger's Equation (TISE) for the Simple Linear Potentials (SLPs) with a turning point parameter have been studied according to the turning points by graphical analysis to test the results of the JWKB solutions and suggested modifications. The anomalies happening in the classically inaccessible region where the SLP function is smaller than zero and the results of the suggested modifications, which are in consistent with the quantum mechanical theories, to remove these anomalies in this region have been presented. The origins of the anomalies and verifications of the suggestedmore » modifications showing a great success in the results have also been studied in terms of a suggested M{sub ij}=S{sup {approx}}{sub i-1,j} matrix elements made up of the JWKB expansion terms, S{sub i-1,j} (where i = 1, 2, 3 and j 1, 2). The results of the modifications for the IVPs and their application to the Bound State Problems (BSPs) with an example application of the Harmonic Oscillator (HO) have been presented and their generalization for any potential function have been discussed and classified accordingly.« less

Childhood Physical and Sexual Abuse and Social Network Patterns on Social Media: Associations With Alcohol Use and Problems Among Young Adult Women

PubMed Central

Oshri, Assaf; Himelboim, Itai; Kwon, Josephine A.; Sutton, Tara E.; Mackillop, James

2015-01-01

Objective: The aim of the present study was to examine the links between severities of child abuse (physical vs. sexual), and alcohol use versus problems via social media (Facebook) peer connection structures. Method: A total of 318 undergraduate female students at a public university in the United States reported severity of child abuse experiences and current alcohol use and problems. Social network data were obtained directly from the individuals’ Facebook network. Results: Severity of childhood physical abuse was positively linked to alcohol use and problems via eigenvector centrality, whereas severity of childhood sexual abuse was negatively linked to alcohol use and problems via clustering coefficient. Conclusions: Childhood physical and sexual abuse were linked positively and negatively, respectively, to online social network patterns associated with alcohol use and problems. The study suggests the potential utility of these online network patterns as risk indices and ultimately using social media as a platform for targeted preventive interventions. PMID:26562592

A Direct Mapping of Max k-SAT and High Order Parity Checks to a Chimera Graph

PubMed Central

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

Finite element solution of transient fluid-structure interaction problems

NASA Technical Reports Server (NTRS)

Everstine, Gordon C.; Cheng, Raymond S.; Hambric, Stephen A.

1991-01-01

A finite element approach using NASTRAN is developed for solving time-dependent fluid-structure interaction problems, with emphasis on the transient scattering of acoustic waves from submerged elastic structures. Finite elements are used for modeling both structure and fluid domains to facilitate the graphical display of the wave motion through both media. For the liquid, the use of velocity potential as the fundamental unknown results in a symmetric matrix equation. The approach is illustrated for the problem of transient scattering from a submerged elastic spherical shell subjected to an incident tone burst. The use of an analogy between the equations of elasticity and the wave equation of acoustics, a necessary ingredient to the procedure, is summarized.

Primal-dual methods of shape sensitivity analysis for curvilinear cracks with nonpenetration

NASA Astrophysics Data System (ADS)

Kovtunenko, V. A.

2006-10-01

Based on a level-set description of a crack moving with a given velocity, the problem of shape perturb-ation of the crack is considered. Nonpenetration conditions are imposed between opposite crack surfaces which result in a constrained minimization problem describing equilibrium of a solid with the crack. We suggest a minimax formulation of the state problem thus allowing curvilinear (nonplanar) cracks for the consideration. Utilizing primal-dual methods of shape sensitivity analysis we obtain the general formula for a shape derivative of the potential energy, which describes an energy-release rate for the curvilinear cracks. The conditions sufficient to rewrite it in the form of a path-independent integral (J-integral) are derived.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zaporozhets, Irina A.; Ivanov, Vladimir V.; Lyakh, Dmitry I.

The earlier proposed multi-reference state-specific coupled-cluster theory with the complete active space reference suffered from a problem of energy discontinuities when the formal reference state was changing in the calculation of the potential energy curve (PEC). A simple remedy to the discontinuity problem is found and is presented in this work. It involves using natural complete active space self-consistent field active orbitals in the complete active space coupled-cluster calculations. As a result, the approach gives smooth PECs for different types of dissociation problems, as illustrated in the calculations of the dissociation of the single bond in the hydrogen fluorine moleculemore » and of the symmetric double-bond dissociation in the water molecule.« less

Silica problem in the design of geothermal power plants

NASA Astrophysics Data System (ADS)

Dipippo, R.

1985-02-01

The silica problem is examined from the perspective of the power plant designer to develop a procedure to enable a quick estimate to be made of the potential seriousness of the silica deposition problem for a wide variety of resources and for selected types of power plant. The method employs correlations for the equilibrium solubilities of quartz and amorphous silica and for the saturated liquid enthalpy and the latent heat of water substance. Single- and double-flash plants optimized for highest thermodynamic efficiency are considered. Binary-type plants are included generically without mention of cycle specifics. The results are presented both graphically and in tabular form, and the governing equations will be given in an easily-programmable form.

Modeling crowdsourcing as collective problem solving

NASA Astrophysics Data System (ADS)

Guazzini, Andrea; Vilone, Daniele; Donati, Camillo; Nardi, Annalisa; Levnajić, Zoran

2015-11-01

Crowdsourcing is a process of accumulating the ideas, thoughts or information from many independent participants, with aim to find the best solution for a given challenge. Modern information technologies allow for massive number of subjects to be involved in a more or less spontaneous way. Still, the full potentials of crowdsourcing are yet to be reached. We introduce a modeling framework through which we study the effectiveness of crowdsourcing in relation to the level of collectivism in facing the problem. Our findings reveal an intricate relationship between the number of participants and the difficulty of the problem, indicating the optimal size of the crowdsourced group. We discuss our results in the context of modern utilization of crowdsourcing.

Dominant takeover regimes for genetic algorithms

NASA Technical Reports Server (NTRS)

Noever, David; Baskaran, Subbiah

1995-01-01

The genetic algorithm (GA) is a machine-based optimization routine which connects evolutionary learning to natural genetic laws. The present work addresses the problem of obtaining the dominant takeover regimes in the GA dynamics. Estimated GA run times are computed for slow and fast convergence in the limits of high and low fitness ratios. Using Euler's device for obtaining partial sums in closed forms, the result relaxes the previously held requirements for long time limits. Analytical solution reveal that appropriately accelerated regimes can mark the ascendancy of the most fit solution. In virtually all cases, the weak (logarithmic) dependence of convergence time on problem size demonstrates the potential for the GA to solve large N-P complete problems.

Over the Horizon: Potential Impact of Emerging Trends in Information and Communication Technology on Disability Policy and Practice

ERIC Educational Resources Information Center

Vanderheiden, Gregg

2006-01-01

This policy paper explores key trends in information and communication technology, highlights the potential opportunities and problems these trends present for people with disabilities, and suggests some strategies to maximize opportunities and avoid potential problems and barriers. Specifically, this paper discusses technology trends that present…

Bose–Einstein condensation temperature of finite systems

NASA Astrophysics Data System (ADS)

Xie, Mi

2018-05-01

In studies of the Bose–Einstein condensation of ideal gases in finite systems, the divergence problem usually arises in the equation of state. In this paper, we present a technique based on the heat kernel expansion and zeta function regularization to solve the divergence problem, and obtain the analytical expression of the Bose–Einstein condensation temperature for general finite systems. The result is represented by the heat kernel coefficients, where the asymptotic energy spectrum of the system is used. Besides the general case, for systems with exact spectra, e.g. ideal gases in an infinite slab or in a three-sphere, the sums of the spectra can be obtained exactly and the calculation of corrections to the critical temperatures is more direct. For a system confined in a bounded potential, the form of the heat kernel is different from the usual heat kernel expansion. We show that as long as the asymptotic form of the global heat kernel can be found, our method works. For Bose gases confined in three- and two-dimensional isotropic harmonic potentials, we obtain the higher-order corrections to the usual results of the critical temperatures. Our method can also be applied to the problem of generalized condensation, and we give the correction of the boundary on the second critical temperature in a highly anisotropic slab.

Some remarks on the attractor behaviour in ELKO cosmology

NASA Astrophysics Data System (ADS)

Pereira, S. H.; A. Pinho S., S.; Hoff da Silva, J. M.

2014-08-01

Recent results on the dynamical stability of a system involving the interaction of the ELKO spinor field with standard matter in the universe have been reanalysed, and the conclusion is that such system does not exhibit isolated stable points that could alleviate the cosmic coincidence problem. When a constant parameter δ related to the potential of the ELKO field is introduced in the system however, stable fixed points are found for some specific types of interaction between the ELKO field and matter. Although the parameter δ is related to an unknown potential, in order to satisfy the stability conditions and also that the fixed points are real, the range of the constant parameter δ can be constrained for the present time and the coincidence problem can be alleviated for some specific interactions. Such restriction on the ELKO potential opens possibility to apply the ELKO field as a candidate to dark energy in the universe, and so explain the present phase of acceleration of the universe through the decay of the ELKO field into matter.

Artificial Intelligence in Precision Cardiovascular Medicine.

PubMed

Krittanawong, Chayakrit; Zhang, HongJu; Wang, Zhen; Aydar, Mehmet; Kitai, Takeshi

2017-05-30

Artificial intelligence (AI) is a field of computer science that aims to mimic human thought processes, learning capacity, and knowledge storage. AI techniques have been applied in cardiovascular medicine to explore novel genotypes and phenotypes in existing diseases, improve the quality of patient care, enable cost-effectiveness, and reduce readmission and mortality rates. Over the past decade, several machine-learning techniques have been used for cardiovascular disease diagnosis and prediction. Each problem requires some degree of understanding of the problem, in terms of cardiovascular medicine and statistics, to apply the optimal machine-learning algorithm. In the near future, AI will result in a paradigm shift toward precision cardiovascular medicine. The potential of AI in cardiovascular medicine is tremendous; however, ignorance of the challenges may overshadow its potential clinical impact. This paper gives a glimpse of AI's application in cardiovascular clinical care and discusses its potential role in facilitating precision cardiovascular medicine. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Intergenerational Transmission of Maladaptive Parenting Strategies in Families of Adolescent Mothers: Effects from Grandmothers to Young Children

PubMed Central

Seay, Danielle M.; Jahromi, Laudan B.; Umaña-Taylor, Adriana J.; Updegraff, Kimberly A.

2015-01-01

The current longitudinal study examined the effect of the transmission of maladaptive parenting strategies from grandmothers to adolescent mothers on children’s subsequent development. Mexican-origin adolescent mothers (N = 204) participated in home interviews when the adolescent’s child (89 boys, 60 girls) was 2, 3, 4, and 5 years old. Grandmothers’ psychological control toward the adolescent mother was positively related to adolescents’ potential for abuse 1 year later, which was subsequently positively related to adolescents’ punitive discipline toward their young child. In addition, adolescent mothers’ punitive discipline subsequently predicted greater externalizing problems and less committed compliance among their children. Adolescent mothers’ potential for abuse and punitive discipline mediated the effects of grandmothers’ psychological control on children’s externalizing problems. Finally, adolescent mothers’ potential for abuse mediated the effect of grandmothers’ psychological control on adolescent mothers’ punitive discipline. Results highlight the salience of long-term intergenerational effects of maladaptive parenting on children’s behavior. PMID:26521948

Application of differential evolution algorithm on self-potential data.

PubMed

Li, Xiangtao; Yin, Minghao

2012-01-01

Differential evolution (DE) is a population based evolutionary algorithm widely used for solving multidimensional global optimization problems over continuous spaces, and has been successfully used to solve several kinds of problems. In this paper, differential evolution is used for quantitative interpretation of self-potential data in geophysics. Six parameters are estimated including the electrical dipole moment, the depth of the source, the distance from the origin, the polarization angle and the regional coefficients. This study considers three kinds of data from Turkey: noise-free data, contaminated synthetic data, and Field example. The differential evolution and the corresponding model parameters are constructed as regards the number of the generations. Then, we show the vibration of the parameters at the vicinity of the low misfit area. Moreover, we show how the frequency distribution of each parameter is related to the number of the DE iteration. Experimental results show the DE can be used for solving the quantitative interpretation of self-potential data efficiently compared with previous methods.

Application of Differential Evolution Algorithm on Self-Potential Data

PubMed Central

Li, Xiangtao; Yin, Minghao

2012-01-01

Differential evolution (DE) is a population based evolutionary algorithm widely used for solving multidimensional global optimization problems over continuous spaces, and has been successfully used to solve several kinds of problems. In this paper, differential evolution is used for quantitative interpretation of self-potential data in geophysics. Six parameters are estimated including the electrical dipole moment, the depth of the source, the distance from the origin, the polarization angle and the regional coefficients. This study considers three kinds of data from Turkey: noise-free data, contaminated synthetic data, and Field example. The differential evolution and the corresponding model parameters are constructed as regards the number of the generations. Then, we show the vibration of the parameters at the vicinity of the low misfit area. Moreover, we show how the frequency distribution of each parameter is related to the number of the DE iteration. Experimental results show the DE can be used for solving the quantitative interpretation of self-potential data efficiently compared with previous methods. PMID:23240004

Inverse Scattering Problem For The Schrödinger Equation With An Additional Quadratic Potential On The Entire Axis

NASA Astrophysics Data System (ADS)

Guseinov, I. M.; Khanmamedov, A. Kh.; Mamedova, A. F.

2018-04-01

We consider the Schrödinger equation with an additional quadratic potential on the entire axis and use the transformation operator method to study the direct and inverse problems of the scattering theory. We obtain the main integral equations of the inverse problem and prove that the basic equations are uniquely solvable.

Childhood conduct problems and young adult outcomes among women with childhood attention-deficit/hyperactivity disorder (ADHD).

PubMed

Owens, Elizabeth B; Hinshaw, Stephen P

2016-02-01

We tested whether conduct problems predicted young adult functioning and psychiatric symptoms among women diagnosed with attention-deficit/hyperactivity disorder (ADHD) during childhood, in the context of 3 potential adolescent mediators: internalizing problems, peer rejection, and school failure and disciplinary problems. We controlled for childhood ADHD severity, IQ, and demographic factors, and in the mediational tests, for adolescent conduct problems. Data came from 140 participants in the Berkeley Girls With ADHD Longitudinal Study. We used bootstrapping methods to assess indirect effects (mediators). Both childhood, F(1, 118) change = 9.00, p = .003, R2 change = .069, and adolescent, F(1, 109) change = 10.41, p = .002, R2 change = .083, conduct problems were associated with worse overall functioning during young adulthood, controlling for initial ADHD severity, child IQ, and demographics. Results were similar when predicting psychiatric symptoms. Adolescent school failure and disciplinary problems mediated the relations between childhood conduct problems and both young adult functioning and externalizing problems; adolescent internalizing problems and peer conflict mediated the relation between childhood conduct problems and young adult internalizing problems. As is true for boys, childhood and adolescent conduct problems are associated with poor adult outcomes among girls with ADHD, with school failure and disciplinary problems, internalizing problems, and peer conflict functioning as mediators of these relations. (c) 2016 APA, all rights reserved).

Graded meshes in bio-thermal problems with transmission-line modeling method.

PubMed

Milan, Hugo F M; Carvalho, Carlos A T; Maia, Alex S C; Gebremedhin, Kifle G

2014-10-01

In this study, the transmission-line modeling (TLM) applied to bio-thermal problems was improved by incorporating several novel computational techniques, which include application of graded meshes which resulted in 9 times faster in computational time and uses only a fraction (16%) of the computational resources used by regular meshes in analyzing heat flow through heterogeneous media. Graded meshes, unlike regular meshes, allow heat sources to be modeled in all segments of the mesh. A new boundary condition that considers thermal properties and thus resulting in a more realistic modeling of complex problems is introduced. Also, a new way of calculating an error parameter is introduced. The calculated temperatures between nodes were compared against the results obtained from the literature and agreed within less than 1% difference. It is reasonable, therefore, to conclude that the improved TLM model described herein has great potential in heat transfer of biological systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hybrid water flow-like algorithm with Tabu search for traveling salesman problem

NASA Astrophysics Data System (ADS)

Bostamam, Jasmin M.; Othman, Zulaiha

2016-08-01

This paper presents a hybrid Water Flow-like Algorithm with Tabu Search for solving travelling salesman problem (WFA-TS-TSP).WFA has been proven its outstanding performances in solving TSP meanwhile TS is a conventional algorithm which has been used since decades to solve various combinatorial optimization problem including TSP. Hybridization between WFA with TS provides a better balance of exploration and exploitation criteria which are the key elements in determining the performance of one metaheuristic. TS use two different local search namely, 2opt and 3opt separately. The proposed WFA-TS-TSP is tested on 23 sets on the well-known benchmarked symmetric TSP instances. The result shows that the proposed WFA-TS-TSP has significant better quality solutions compared to WFA. The result also shows that the WFA-TS-TSP with 3-opt obtained the best quality solution. With the result obtained, it could be concluded that WFA has potential to be further improved by using hybrid technique or using better local search technique.

The free versus fixed geodetic boundary value problem for different combinations of geodetic observables

NASA Astrophysics Data System (ADS)

Grafarend, E. W.; Heck, B.; Knickmeyer, E. H.

1985-03-01

Various formulations of the geodetic fixed and free boundary value problem are presented, depending upon the type of boundary data. For the free problem, boundary data of type astronomical latitude, astronomical longitude and a pair of the triplet potential, zero and first-order vertical gradient of gravity are presupposed. For the fixed problem, either the potential or gravity or the vertical gradient of gravity is assumed to be given on the boundary. The potential and its derivatives on the boundary surface are linearized with respect to a reference potential and a reference surface by Taylor expansion. The Eulerian and Lagrangean concepts of a perturbation theory of the nonlinear geodetic boundary value problem are reviewed. Finally the boundary value problems are solved by Hilbert space techniques leading to new generalized Stokes and Hotine functions. Reduced Stokes and Hotine functions are recommended for numerical reasons. For the case of a boundary surface representing the topography a base representation of the solution is achieved by solving an infinite dimensional system of equations. This system of equations is obtained by means of the product-sum-formula for scalar surface spherical harmonics with Wigner 3j-coefficients.

Back-Projection Cortical Potential Imaging: Theory and Results.

PubMed

Haor, Dror; Shavit, Reuven; Shapiro, Moshe; Geva, Amir B

2017-07-01

Electroencephalography (EEG) is the single brain monitoring technique that is non-invasive, portable, passive, exhibits high-temporal resolution, and gives a directmeasurement of the scalp electrical potential. Amajor disadvantage of the EEG is its low-spatial resolution, which is the result of the low-conductive skull that "smears" the currents coming from within the brain. Recording brain activity with both high temporal and spatial resolution is crucial for the localization of confined brain activations and the study of brainmechanismfunctionality, whichis then followed by diagnosis of brain-related diseases. In this paper, a new cortical potential imaging (CPI) method is presented. The new method gives an estimation of the electrical activity on the cortex surface and thus removes the "smearing effect" caused by the skull. The scalp potentials are back-projected CPI (BP-CPI) onto the cortex surface by building a well-posed problem to the Laplace equation that is solved by means of the finite elements method on a realistic head model. A unique solution to the CPI problem is obtained by introducing a cortical normal current estimation technique. The technique is based on the same mechanism used in the well-known surface Laplacian calculation, followed by a scalp-cortex back-projection routine. The BP-CPI passed four stages of validation, including validation on spherical and realistic head models, probabilistic analysis (Monte Carlo simulation), and noise sensitivity tests. In addition, the BP-CPI was compared with the minimum norm estimate CPI approach and found superior for multi-source cortical potential distributions with very good estimation results (CC >0.97) on a realistic head model in the regions of interest, for two representative cases. The BP-CPI can be easily incorporated in different monitoring tools and help researchers by maintaining an accurate estimation for the cortical potential of ongoing or event-related potentials in order to have better neurological inferences from the EEG.

QCD at finite isospin chemical potential

NASA Astrophysics Data System (ADS)

Brandt, Bastian B.; Endrődi, Gergely; Schmalzbauer, Sebastian

2018-03-01

We investigate the properties of QCD at finite isospin chemical potential at zero and non-zero temperatures. This theory is not affected by the sign problem and can be simulated using Monte-Carlo techniques. With increasing isospin chemical potential and temperatures below the deconfinement transition the system changes into a phase where charged pions condense, accompanied by an accumulation of low modes of the Dirac operator. The simulations are enabled by the introduction of a pionic source into the action, acting as an infrared regulator for the theory, and physical results are obtained by removing the regulator via an extrapolation. We present an update of our study concerning the associated phase diagram using 2+1 flavours of staggered fermions with physical quark masses and the comparison to Taylor expansion. We also present first results for our determination of the equation of state at finite isospin chemical potential and give an example for a cosmological application. The results can also be used to gain information about QCD at small baryon chemical potentials using reweighting with respect to the pionic source parameter and the chemical potential and we present first steps in this direction.

Topics in viscous potential flow of two-phase systems

NASA Astrophysics Data System (ADS)

Padrino Inciarte, Juan Carlos

Two-phase flows are ubiquitous, from natural and domestic environments to industrial settings. However, due to their complexity, modeling these fluid systems remains a challenge from both the perspective of fundamental questions on the dynamics of an individual, smooth interface, and the perspective of integral analyses, which involve averaging of the conservation laws over large domains, thereby missing local details of the flow. In this work, we consider a set of five problems concerning the linear and non-linear dynamics of an interface or free surface and the study of cavitation inception. Analyses are carried out by assuming the fluid motion to be irrotational, that is, with zero vorticity, and the fluids to be viscous, although results from rotational analyses are presented for the purpose of comparison. The problems considered here are the following: First, we analyze the non-linear deformation and break-up of a bubble or drop immersed in a uniaxial extensional flow of an incompressible viscous fluid. The method of viscous potential flow, in which the flow field is irrotational and viscosity enters through the balance of normal stresses at the interface, is used in the analysis. The governing equations are solved numerically to track the motion of the interface by coupling a boundary element method with a time-integration routine. When break-up occurs, the break-up time computed here is compared with results obtained elsewhere from numerical simulations of the Navier.Stokes equations, which thus keeps vorticity in the analysis, for several combinations of the relevant dimensionless parameters of the problem. For the bubble, for Weber numbers 3 ≤ We ≤ 6, predictions from viscous potential flow shows good agreement with the results from the Navier.Stokes equations for the bubble break-up time, whereas for larger We, the former underpredicts the results given by the latter. Including viscosity increases the break-up time with respect to the inviscid case. For the drop, as expected, increasing the viscous effects of the irrotational motion produces large, elongated drops that take longer to break up in comparison with results for inviscid fluids. In the second problem, we compute the force acting on a spherical bubble of variable radius moving within a liquid with an outer spherical boundary. Viscous potential flow and the dissipation method, which is another purely irrotational approach stemming from the mechanical energy equation, are both systematically implemented. This exposes the role of the choice of the outer boundary condition for the stress on the drag, an issue not explained in the literature known to us. By means of the well-known "cell-model" analysis, the results for the drag are then applied to the case of a swarm of rising bubbles having a certain void fraction. Computations from the dissipation method for the drag coefficient and rise velocity for a bubble swarm agree with numerical solutions; evaluation against experimental data for high Reynolds and low Weber numbers shows that all the models considered, including those given in the literature, overpredict the bubble swarm rise velocity. In the next two problems, we apply the analysis of viscous potential flow and the dissipation method to study the linear dynamics of waves of "small" amplitude acting either on a plane or on a spherical interface separating a liquid from a dynamically inactive fluid. It is shown that the viscous irrational theories exhibit the features of the wave dynamics by comparing with the exact solution. The range of parameters for which good agreement with the exact solution exists is presented. The general trend shows that for long waves the dissipation method results in the best approximation, whereas for short waves, even for very viscous liquids, viscous potential flow demonstrates better agreement. Finally, the problem of cavitation inception for the flow of a viscous liquid past a stationary sphere is studied by means of the theory of stress-induced cavitation. The flow field for a single phase needed in the analysis is found from three different methods, namely, the numerical solution of the Navier--Stokes equations, the irrotational motion of a viscous fluid, and, in the limit of no inertia, the Stokes flow formulation. The new predictions are then compared with those obtained from the classical pressure criterion. The main finding is that at a fixed cavitation number more viscous liquids are at greater risk to cavitation.

The Limited Role of Expert Guidelines in Teaching Psychopharmacology

ERIC Educational Resources Information Center

Salzman, Carl

2005-01-01

Objective: To consider the limited usefulness of expert guidelines for teaching psychopharmacology. Method: Potential problems using expert guidelines for teaching psychopharmacology are reviewed. Results: Expert guidelines are an important contribution to the growth of evidence-based psychiatry. As such, they may also be used to teach…

Ecological Effects of Weather Modification: A Problem Analysis.

ERIC Educational Resources Information Center

Cooper, Charles F.; Jolly, William C.

This publication reviews the potential hazards to the environment of weather modification techniques as they eventually become capable of producing large scale weather pattern modifications. Such weather modifications could result in ecological changes which would generally require several years to be fully evident, including the alteration of…

CHARACTERIZATIONS OF POPULATION AND USAGE OF UNVENTED KEROSENE SPACE HEATERS

EPA Science Inventory

The report gives results of a study of the market penetration of unvented kerosene space heaters (UKSHs) in the residential sector, The study was aimed at gathering baseline information to help assess the magnitude and potential severity of a problem involving emissions from unve...

CHARACTERIZATION OF POPULATION AND USAGE OF UNVENTED KEROSENE SPACE HEATERS

EPA Science Inventory

The report gives results of a study of the market penetration of unvented kerosene space heaters (UKSHs) in the residential sector, The study was aimed at gathering baseline information to help assess the magnitude and potential severity of a problem involving emissions from unve...

Action Learning Enabled Strategy Making

ERIC Educational Resources Information Center

Oliver, John

2008-01-01

Action learning encourages individual reflection, insightful questioning and assumption breaking that result in changes in attitude and behaviour. This learning process provides the potential to explore and solve complex organizational problems such as the question of how to develop a future business strategy. Existing literature on the process of…

AgRISTARS: Supporting research. Classification of corn: Badhwar profile similarity technique. [us corn belt

NASA Technical Reports Server (NTRS)

Austin, W. W. (Principal Investigator)

1981-01-01

The same software programs used to classify spring wheat are applied to the classification of corn in 26 segments in the corn belt. Numerical results of the acreage estimation are given. Potential problem areas defined in an earlier application are examined.

Project Genesis; Pre-School Diagnosis and Programming.

ERIC Educational Resources Information Center

1968

The introduction of a project designed to evaluate children before they enter kindergarten for potential learning problems lists additional objectives and the results of screening preschool children. Post-screening planning for each child, development of a workshop to prepare programers, presentations for parent and faculty education, and…

Application of a Chimera Full Potential Algorithm for Solving Aerodynamic Problems

NASA Technical Reports Server (NTRS)

Holst, Terry L.; Kwak, Dochan (Technical Monitor)

1997-01-01

A numerical scheme utilizing a chimera zonal grid approach for solving the three dimensional full potential equation is described. Special emphasis is placed on describing the spatial differencing algorithm around the chimera interface. Results from two spatial discretization variations are presented; one using a hybrid first-order/second-order-accurate scheme and the second using a fully second-order-accurate scheme. The presentation is highlighted with a number of transonic wing flow field computations.

Methamphetamine in three small Midwestern cities: evidence of a moral panic.

PubMed

Weidner, Robert R

2009-09-01

This study examined the coverage of methamphetamine from 1997 to 2005 by three newspapers serving small Midwestern cities and contrasted their portrayals of methamphetamine problems with available data on the severity of the meth problem in each locality. Results of quantitative and qualitative content analyses show that--to varying degrees, across sites and over time--newspaper coverage of meth was disproportionate to the scale of the meth problem as indicated by site-specific treatment admissions data. To some extent, each of the three newspapers used drug-scare rhetoric (e.g., medical metaphors such as "plague") to describe the prevalence and effects of meth. Results indicate that two of the three newspapers' portrayals of meth were conducive to promoting a moral panic over the drug. Potential explanations for variations in coverage are discussed, and findings are considered in light of research on prior drug scares.

Preschoolers’ Genetic, Physiological, and Behavioral Sensitivity Factors Moderate Links Between Parenting Stress and Child Internalizing, Externalizing, and Sleep Problems

PubMed Central

Davis, Molly; Thomassin, Kristel; Bilms, Joanie; Suveg, Cynthia; Shaffer, Anne; Beach, Steven R. H.

2017-01-01

This study examined three potential moderators of the relations between maternal parenting stress and preschoolers’ adjustment problems: a genetic polymorphism - the short allele of the serotonin transporter (5-HTTLPR, ss/sl allele) gene, a physiological indicator - children’s baseline respiratory sinus arrhythmia (RSA), and a behavioral indicator - mothers’ reports of children’s negative emotionality. A total of 108 mothers (Mage = 30.68 years, SDage = 6.06) reported on their parenting stress as well as their preschoolers’ (Mage = 3.50 years, SDage = .51, 61% boys) negative emotionality and internalizing, externalizing, and sleep problems. Results indicated that the genetic sensitivity variable functioned according to a differential susceptibility model; however, the results involving physiological and behavioral sensitivity factors were most consistent with a diathesis-stress framework. Implications for prevention and intervention efforts to counter the effects of parenting stress are discussed. PMID:28295263

Efficient Simulation Budget Allocation for Selecting an Optimal Subset

NASA Technical Reports Server (NTRS)

Chen, Chun-Hung; He, Donghai; Fu, Michael; Lee, Loo Hay

2008-01-01

We consider a class of the subset selection problem in ranking and selection. The objective is to identify the top m out of k designs based on simulated output. Traditional procedures are conservative and inefficient. Using the optimal computing budget allocation framework, we formulate the problem as that of maximizing the probability of correc tly selecting all of the top-m designs subject to a constraint on the total number of samples available. For an approximation of this corre ct selection probability, we derive an asymptotically optimal allocat ion and propose an easy-to-implement heuristic sequential allocation procedure. Numerical experiments indicate that the resulting allocatio ns are superior to other methods in the literature that we tested, and the relative efficiency increases for larger problems. In addition, preliminary numerical results indicate that the proposed new procedur e has the potential to enhance computational efficiency for simulation optimization.

Effects of research tool patents on biotechnology innovation in a developing country: a case study of South Korea.

PubMed

Kang, Kyung-Nam; Ryu, Tae-Kyu; Lee, Yoon-Sik

2009-03-26

Concerns have recently been raised about the negative effects of patents on innovation. In this study, the effects of patents on innovations in the Korean biotech SMEs (small and medium-sized entrepreneurs) were examined using survey data and statistical analysis. The survey results of this study provided some evidence that restricted access problems have occurred even though their frequency was not high. Statistical analysis revealed that difficulties in accessing patented research tools were not negatively correlated with the level of innovation performance and attitudes toward the patent system. On the basis of the results of this investigation in combination with those of previous studies, we concluded that although restricted access problems have occurred, this has not yet deterred innovation in Korea. However, potential problems do exist, and the effects of restricted access should be constantly scrutinized.

Using satellite fire detection to calibrate components of the fire weather index system in Malaysia and Indonesia.

PubMed

Dymond, Caren C; Field, Robert D; Roswintiarti, Orbita; Guswanto

2005-04-01

Vegetation fires have become an increasing problem in tropical environments as a consequence of socioeconomic pressures and subsequent land-use change. In response, fire management systems are being developed. This study set out to determine the relationships between two aspects of the fire problems in western Indonesia and Malaysia, and two components of the Canadian Forest Fire Weather Index System. The study resulted in a new method for calibrating components of fire danger rating systems based on satellite fire detection (hotspot) data. Once the climate was accounted for, a problematic number of fires were related to high levels of the Fine Fuel Moisture Code. The relationship between climate, Fine Fuel Moisture Code, and hotspot occurrence was used to calibrate Fire Occurrence Potential classes where low accounted for 3% of the fires from 1994 to 2000, moderate accounted for 25%, high 26%, and extreme 38%. Further problems arise when there are large clusters of fires burning that may consume valuable land or produce local smoke pollution. Once the climate was taken into account, the hotspot load (number and size of clusters of hotspots) was related to the Fire Weather Index. The relationship between climate, Fire Weather Index, and hotspot load was used to calibrate Fire Load Potential classes. Low Fire Load Potential conditions (75% of an average year) corresponded with 24% of the hotspot clusters, which had an average size of 30% of the largest cluster. In contrast, extreme Fire Load Potential conditions (1% of an average year) corresponded with 30% of the hotspot clusters, which had an average size of 58% of the maximum. Both Fire Occurrence Potential and Fire Load Potential calibrations were successfully validated with data from 2001. This study showed that when ground measurements are not available, fire statistics derived from satellite fire detection archives can be reliably used for calibration. More importantly, as a result of this work, Malaysia and Indonesia have two new sources of information to initiate fire prevention and suppression activities.

Estimation of Rotary Stability Derivatives at Subsonic and Transonic Speeds

NASA Technical Reports Server (NTRS)

Tobak, Murray; Lessing, Henry C.

1961-01-01

The first part of this paper pertains to the estimation of subsonic rotary stability derivatives of wings. The unsteady potential flow problem is solved by a superposition of steady flow solutions. Numerical results for the damping coefficients of triangular wings are presented as functions of aspect ratio and Mach number, and are compared with experimental results over the Mach number range 0 to 1. In the second part, experimental results are used. to point out a close correlation between the nonlinear variations with angle of attack of the static pitching-moment curve slope and the damping-in-pitch coefficient. The underlying basis for the correlation is found as a result of an analysis in which the indicial function concept and. the principle of super-position are adapted to apply to the nonlinear problem. The form of the result suggests a method of estimating nonlinear damping coefficients from results of static wind-tunnel measurements.

Interpersonal Problem-Solving Skills, Executive Function and Learning Potential in Preadolescents with High/Low Family Risk.

PubMed

Mata, Sara; Gómez-Pérez, M Mar; Molinero, Clara; Calero, M Dolores

2017-10-30

Situations generated by high family risk have a negative effect on personal development, especially during preadolescence. Growing up in the presence of risk factors can lead to negative consequences on mental health or on school performance. The objective of this study focuses on individual factors related to this phenomenon during preadolescence. Specifically, we seek to establish whether level of family risk (high vs. low risk) is related to interpersonal problem-solving skills, executive function and learning potential in a sample of preadolescents controlling age, sex, total IQ, verbal comprehension ability and the classroom influences. The participants were 40 children, 23 boys and 17 girls between the ages of 7 and 12, twenty of which had a record on file with the Social and Childhood Protection Services of Information deleted to maintain the integrity of the review process, and therefore, a high family risk situation. The other 20 participants had a low family risk situation. Results show that the preadolescents from high family risk performed worse on interpersonal solving-problem skills and executive function (p < .05, b from -119,201.81 to 132,199.43, confidence interval from -162,589.78/-75,813.8 to 84,403.05/179,995.8). Nevertheless, they showed the same ability to learn as the participants from low family risk. These results highlight the negative effects of high family risk situation in preadolescents and give value of taking into account protective factors such as learning potential when assessing preadolescents from high family risk.

Detecting single-trial EEG evoked potential using a wavelet domain linear mixed model: application to error potentials classification.

PubMed

Spinnato, J; Roubaud, M-C; Burle, B; Torrésani, B

2015-06-01

The main goal of this work is to develop a model for multisensor signals, such as magnetoencephalography or electroencephalography (EEG) signals that account for inter-trial variability, suitable for corresponding binary classification problems. An important constraint is that the model be simple enough to handle small size and unbalanced datasets, as often encountered in BCI-type experiments. The method involves the linear mixed effects statistical model, wavelet transform, and spatial filtering, and aims at the characterization of localized discriminant features in multisensor signals. After discrete wavelet transform and spatial filtering, a projection onto the relevant wavelet and spatial channels subspaces is used for dimension reduction. The projected signals are then decomposed as the sum of a signal of interest (i.e., discriminant) and background noise, using a very simple Gaussian linear mixed model. Thanks to the simplicity of the model, the corresponding parameter estimation problem is simplified. Robust estimates of class-covariance matrices are obtained from small sample sizes and an effective Bayes plug-in classifier is derived. The approach is applied to the detection of error potentials in multichannel EEG data in a very unbalanced situation (detection of rare events). Classification results prove the relevance of the proposed approach in such a context. The combination of the linear mixed model, wavelet transform and spatial filtering for EEG classification is, to the best of our knowledge, an original approach, which is proven to be effective. This paper improves upon earlier results on similar problems, and the three main ingredients all play an important role.

Immunosensor development formatting for tungro disease detection using nano-gold antibody particles application

NASA Astrophysics Data System (ADS)

Uda, M. N. A.; Hasfalina, C. M.; Samsuzanaa, A. A.; Faridah, S.; Zamri, I.; Noraini, B. Siti; Sabrina, W. Nur; Hashim, U.; Gopinath, Subash C. B.

2017-03-01

The plant disease such as Rice tungro disease (RTD) becomes a major problem in rice production and also will effect in the economy loss in the country. Therefore, to tackle this problem at early stages, the immunosensor application is a most reliable sensor nowadays because of advantages towards detecting biological molecule. Thus, in order to deal with immunosensor development, it can be done by undergoing the formation of immunosensor format on screen-printed carbon electrode (SPCE). Results can be elaborated with the potential applications to detect the viruses.

Preliminary assessment of aerial photography techniques for canvasback population analysis

USGS Publications Warehouse

Munro, R.E.; Trauger, D.L.

1976-01-01

Recent intensive research on the canvasback has focused attention on the need for more precise estimates of population parameters. During the 1972-75 period, various types of aerial photographing equipment were evaluated to determine the problems and potentials for employing these techniques in appraisals of canvasback populations. The equipment and procedures available for automated analysis of aerial photographic imagery were also investigated. Serious technical problems remain to be resolved, but some promising results were obtained. Final conclusions about the feasibility of operational implementation await a more rigorous analysis of the data collected.

On the solution of integral equations with a generalized Cauchy kernel

NASA Technical Reports Server (NTRS)

Kaya, A. C.; Erdogan, F.

1987-01-01

A numerical technique is developed analytically to solve a class of singular integral equations occurring in mixed boundary-value problems for nonhomogeneous elastic media with discontinuities. The approach of Kaya and Erdogan (1987) is extended to treat equations with generalized Cauchy kernels, reformulating the boundary-value problems in terms of potentials as the unknown functions. The numerical implementation of the solution is discussed, and results for an epoxy-Al plate with a crack terminating at the interface and loading normal to the crack are presented in tables.

Substance Abuse Screening and Treatment.

PubMed

Tenegra, Johnny C; Leebold, Bobby

2016-06-01

One of the more prevalent and often undiagnosed problems seen by primary care clinicians is substance misuse. Resulting in increased morbidity and mortality, loss of productivity, and increased health care costs, substance misuse in our society remains a significant public health issue. Primary care physicians are on the front lines of medical care, and as such, are in a distinctive position to recognize potential problems in this area and assist. This article outlines office-based screening approaches and strategies for managing and treating this complex issue confronting primary care. Copyright © 2016 Elsevier Inc. All rights reserved.

Comment on "Out-of-plane equilibrium points in the restricted three-body problem with oblateness (Research Note)"

NASA Astrophysics Data System (ADS)

Wu, Nan; Wang, Xuefeng; Zhou, Li-Yong

2018-06-01

Douskos & Markellos (2006, A&A, 446, 357) first reported the existence of the out-of-plane equilibrium points in restricted three-body problem with oblateness. This result deviates significantly from the intuitive physical point of view that there is no other force that can balance the combined gravitation in Z direction. In fact, the out-of-plane equilibrium in that model is illusory and we prove here that such equilibrium points arise from the improper application of the potential function.

The Second NASA Formal Methods Workshop 1992

NASA Technical Reports Server (NTRS)

Johnson, Sally C. (Compiler); Holloway, C. Michael (Compiler); Butler, Ricky W. (Compiler)

1992-01-01

The primary goal of the workshop was to bring together formal methods researchers and aerospace industry engineers to investigate new opportunities for applying formal methods to aerospace problems. The first part of the workshop was tutorial in nature. The second part of the workshop explored the potential of formal methods to address current aerospace design and verification problems. The third part of the workshop involved on-line demonstrations of state-of-the-art formal verification tools. Also, a detailed survey was filled in by the attendees; the results of the survey are compiled.

Vapor-delivered lubrication of steel-steel and steel-ceramic systems

NASA Astrophysics Data System (ADS)

Li, H.; Klaus, E. E.; Duda, J. L.

1993-04-01

Heavy-duty natural gas engines run hot and relatively dry. This provides lubricant and lubrication problems in the piston ring-cylinder and valve areas. A potential materials solution to this problem is the use of ceramic bearing surfaces. The objective of the project was the investigation of the wear characteristics and surface interactions of lubricants on ceramic bearing surfaces and to compare these results with the behavior of the same lubricants on steel surfaces. The temperature range of interest in these comparisons is 200 to 370 C using a four-ball wear tester.

Bayesian design of decision rules for failure detection

NASA Technical Reports Server (NTRS)

Chow, E. Y.; Willsky, A. S.

1984-01-01

The formulation of the decision making process of a failure detection algorithm as a Bayes sequential decision problem provides a simple conceptualization of the decision rule design problem. As the optimal Bayes rule is not computable, a methodology that is based on the Bayesian approach and aimed at a reduced computational requirement is developed for designing suboptimal rules. A numerical algorithm is constructed to facilitate the design and performance evaluation of these suboptimal rules. The result of applying this design methodology to an example shows that this approach is potentially a useful one.

Monte Carlo simulation of a dynamical fermion problem: The light q sup 2 q sup 2 system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grondin, G.

1991-01-01

We present results from a Guided Random Walk Monte Carlo simulation of the light q{sup 2}{bar q}{sup 2} system in a Coulomb-plus-linear quark potential model using an Intel iPSC/860 hypercube. A solvable model problem is first considered, after which we study the full q{sup 2}{bar q}{sup 2} system in (J,I) = (2,2) and (2,0) sectors. We find evidence for no bound states below the vector-vector threshold in these systems. 17 refs., 6 figs.

The Compressible Stokes Flows with No-Slip Boundary Condition on Non-Convex Polygons

NASA Astrophysics Data System (ADS)

Kweon, Jae Ryong

2017-03-01

In this paper we study the compressible Stokes equations with no-slip boundary condition on non-convex polygons and show a best regularity result that the solution can have without subtracting corner singularities. This is obtained by a suitable Helmholtz decomposition: {{{u}}={{w}}+nablaφ_R} with div w = 0 and a potential φ_R. Here w is the solution for the incompressible Stokes problem and φ_R is defined by subtracting from the solution of the Neumann problem the leading two corner singularities at non-convex vertices.

Potential-splitting approach applied to the Temkin-Poet model for electron scattering off the hydrogen atom and the helium ion

NASA Astrophysics Data System (ADS)

Yarevsky, E.; Yakovlev, S. L.; Larson, Å; Elander, N.

2015-06-01

The study of scattering processes in few body systems is a difficult problem especially if long range interactions are involved. In order to solve such problems, we develop here a potential-splitting approach for three-body systems. This approach is based on splitting the reaction potential into a finite range core part and a long range tail part. The solution to the Schrödinger equation for the long range tail Hamiltonian is found analytically, and used as an incoming wave in the three body scattering problem. This reformulation of the scattering problem makes it suitable for treatment by the exterior complex scaling technique in the sense that the problem after the complex dilation is reduced to a boundary value problem with zero boundary conditions. We illustrate the method with calculations on the electron scattering off the hydrogen atom and the positive helium ion in the frame of the Temkin-Poet model.

Health behaviour and body mass index among problem gamblers: results from a nationwide survey.

PubMed

Algren, Maria H; Ekholm, Ola; Davidsen, Michael; Larsen, Christina V L; Juel, Knud

2015-06-01

Problem gambling is a serious public health issue. The objective of this study was to investigate whether past year problem gamblers differed from non-problem gamblers with regard to health behaviour and body mass index (BMI) among Danes aged 16 years or older. Data were derived from the Danish Health and Morbidity Surveys in 2005 and 2010. Past year problem gambling was defined using the lie/bet questionnaire. Logistic regression analyses were used to examine the association between past year problem gambling and health behaviour and BMI. Problem gambling was associated with unhealthy behaviour and obesity. The odds of smoking was significantly higher among problem gamblers than among non-problem gamblers. Further, the odds of high-risk alcohol drinking and illicit drug use were significantly higher among problem gamblers. The prevalence of sedentary leisure activity, unhealthy diet pattern and obesity was higher among problem gamblers than among non-problem gamblers. The associations found in this study remained significant after adjustment for sex, age, educational and cohabiting status as well as other risk factors. Our findings highlight the presence of a potential, public health challenge and elucidate the need for health promotion initiatives targeted at problem gamblers. Furthermore, more research is needed in order to understand the underlying social mechanism of the association between problem gamblers and unhealthy behaviour.

Trajectories of problem video gaming among adult regular gamers: an 18-month longitudinal study.

PubMed

King, Daniel L; Delfabbro, Paul H; Griffiths, Mark D

2013-01-01

A three-wave, longitudinal study examined the long-term trajectory of problem gaming symptoms among adult regular video gamers. Potential changes in problem gaming status were assessed at two intervals using an online survey over an 18-month period. Participants (N=117) were recruited by an advertisement posted on the public forums of multiple Australian video game-related websites. Inclusion criteria were being of adult age and having a video gaming history of at least 1 hour of gaming every week over the past 3 months. Two groups of adult video gamers were identified: those players who did (N=37) and those who did not (N=80) identify as having a serious gaming problem at the initial survey intake. The results showed that regular gamers who self-identified as having a video gaming problem at baseline reported more severe problem gaming symptoms than normal gamers, at all time points. However, both groups experienced a significant decline in problem gaming symptoms over an 18-month period, controlling for age, video gaming activity, and psychopathological symptoms.

Problem-Solving Skills Appraisal Mediates Hardiness and Suicidal Ideation among Malaysian Undergraduate Students

PubMed Central

Abdollahi, Abbas; Talib, Mansor Abu; Yaacob, Siti Nor; Ismail, Zanariah

2015-01-01

Objectives Recent evidence suggests that suicidal ideation is increased among university students, it is essential to increase our knowledge concerning the etiology of suicidal ideation among university students. This study was conducted to examine the relationships between problem-solving skills appraisal, hardiness, and suicidal ideation among university students. In addition, this study was conducted to examine problem-solving skills appraisal (including the three components of problem-solving confidence, approach-avoidance style, and personal control of emotion) as a potential mediator between hardiness and suicidal ideation. Methods The participants consisted of 500 undergraduate students from Malaysian public universities. Results Structural Equation Modelling (SEM) estimated that undergraduate students with lower hardiness, poor problem-solving confidence, external personal control of emotion, and avoiding style was associated with higher suicidal ideation. Problem-solving skills appraisal (including the three components of problem-solving confidence, approach-avoidance style, and personal control of emotion) partially mediated the relationship between hardiness and suicidal ideation. Conclusion These findings underline the importance of studying mediating processes that explain how hardiness affects suicidal ideation. PMID:25830229

Selected topics on the active control of helicopter aeromechanical and vibration problems

NASA Technical Reports Server (NTRS)

Friedmann, Peretz P.

1994-01-01

This paper describes in a concise manner three selected topics on the active control of helicopter aeromechanical and vibration problems. The three topics are as follows: (1) the active control of helicopter air-resonance using an LQG/LTR approach; (2) simulation of higher harmonic control (HHC) applied to a four bladed hingeless helicopter rotor in forward flight; and (3) vibration suppression in forward flight on a hingeless helicopter rotor using an actively controlled, partial span, trailing edge flap, which is mounted on the blade. Only a few selected illustrative results are presented. The results obtained clearly indicate that the partial span, actively controlled flap has considerable potential for vibration reduction in helicopter rotors.

Using medication list--problem list mismatches as markers of potential error.

PubMed Central

Carpenter, James D.; Gorman, Paul N.

2002-01-01

The goal of this project was to specify and develop an algorithm that will check for drug and problem list mismatches in an electronic medical record (EMR). The algorithm is based on the premise that a patient's problem list and medication list should agree, and a mismatch may indicate medication error. Successful development of this algorithm could mean detection of some errors, such as medication orders entered into a wrong patient record, or drug therapy omissions, that are not otherwise detected via automated means. Additionally, mismatches may identify opportunities to improve problem list integrity. To assess the concept's feasibility, this study compared medications listed in a pharmacy information system with findings in an online nursing adult admission assessment, serving as a proxy for the problem list. Where drug and problem list mismatches were discovered, examination of the patient record confirmed the mismatch, and identified any potential causes. Evaluation of the algorithm in diabetes treatment indicates that it successfully detects both potential medication error and opportunities to improve problem list completeness. This algorithm, once fully developed and deployed, could prove a valuable way to improve the patient problem list, and could decrease the risk of medication error. PMID:12463796

State-space models’ dirty little secrets: even simple linear Gaussian models can have estimation problems

NASA Astrophysics Data System (ADS)

Auger-Méthé, Marie; Field, Chris; Albertsen, Christoffer M.; Derocher, Andrew E.; Lewis, Mark A.; Jonsen, Ian D.; Mills Flemming, Joanna

2016-05-01

State-space models (SSMs) are increasingly used in ecology to model time-series such as animal movement paths and population dynamics. This type of hierarchical model is often structured to account for two levels of variability: biological stochasticity and measurement error. SSMs are flexible. They can model linear and nonlinear processes using a variety of statistical distributions. Recent ecological SSMs are often complex, with a large number of parameters to estimate. Through a simulation study, we show that even simple linear Gaussian SSMs can suffer from parameter- and state-estimation problems. We demonstrate that these problems occur primarily when measurement error is larger than biological stochasticity, the condition that often drives ecologists to use SSMs. Using an animal movement example, we show how these estimation problems can affect ecological inference. Biased parameter estimates of a SSM describing the movement of polar bears (Ursus maritimus) result in overestimating their energy expenditure. We suggest potential solutions, but show that it often remains difficult to estimate parameters. While SSMs are powerful tools, they can give misleading results and we urge ecologists to assess whether the parameters can be estimated accurately before drawing ecological conclusions from their results.

Frontal P300 decrement and executive dysfunction in adolescents with conduct problems.

PubMed

Kim, M S; Kim, J J; Kwon, J S

2001-01-01

This study investigated the cognitive and cerebral function of adolescents with conduct problems by neuropsychological battery (STIM) and event-related potential (ERP). Eighteen adolescents with conduct disorder, and 18 age-matched normal subjects were included. Such cognitive functions as attention, memory, executive function and problem solving were evaluated using subtests of STIM. ERP was measured using an auditory oddball paradigm. The conduct group showed a significantly lower hit rate on the Wisconsin Card Sorting Test (WCST) than the control group. In addition, the conduct group showed reduced P300 amplitude at Fz and Cz, and prolonged P300 latency at Fz, and there was a significant correlation between P300 amplitude and Stroop test performance. These results indicate that adolescents with conduct problems have impairments of executive function and inhibition, and that these impairments are associated with frontal dysfunction.

Pragmatic failure, mind style and characterisation in fiction about autism

PubMed Central

2014-01-01

This article presents an analysis of different types of pragmatic failure in the interactional behaviour of the ‘autistic’ protagonists of three recent novels. Three main types of pragmatic failure occur across all three novels: problems with informativeness and relevance in conversational contributions; problems with face management resulting in unintentional impolite behaviours; and problems with the interpretation of figurative language. These problems are salient and frequent enough to contribute to the projection of distinctive mind styles, and more generally to the characterisation of the protagonists as individuals with communication and socialisation difficulties that are likely to both reflect and reinforce general perceptions of autism-spectrum disorders. It is also argued that pragmatic failure contributes to the potential defamiliarisation of ‘normal’ communication, which is presented as being fraught with obscurity, ambiguity and insincerity. PMID:29710882

The impact of peer victimization on later maladjustment: Mediating and moderating effects of hostile and self-blaming attributions

PubMed Central

Perren, Sonja; Ettekal, Idean; Ladd, Gary

2012-01-01

Background Evidence indicates that being a victim of bullying or peer aggression has negative short- and long-term consequences. In this study, we investigated the mediating and moderating role of two types of attributional mechanisms (hostile and self-blaming attributions) on children’s maladjustment (externalizing and internalizing problems). Methods In total, 478 children participated in this longitudinal study from grade 5 to grade 7. Children, parents and teachers repeatedly completed questionnaires. Peer victimization was assessed through peer reports (T1). Attributions were assessed through self-reports using hypothetical scenarios (T2). Parents and teachers reported on children’s maladjustment (T1 and T3). Results Peer victimization predicted increases in externalizing and internalizing problems. Hostile attributions partially mediated the impact of victimization on increases in externalizing problems. Self-blame was not associated with peer victimization. However, for children with higher levels of self-blaming attributions, peer victimization was linked more strongly with increases in internalizing problems. Conclusions Results imply that hostile attributions may operate as a potential mechanism through which negative experiences with peers lead to increases in children’s aggressive and delinquent behavior, whereas self-blame exacerbates victimization’s effects on internalizing problems. PMID:23057732

Family Resources as Protective Factors for Low-Income Youth Exposed to Community Violence.

PubMed

Hardaway, Cecily R; Sterrett-Hong, Emma; Larkby, Cynthia A; Cornelius, Marie D

2016-07-01

Exposure to community violence is a risk factor for internalizing and externalizing problems; however, resources within the family can decrease the likelihood that adolescents will experience internalizing and externalizing problems as a result of such exposure. This study investigates the potential moderating effects of kinship support (i.e., emotional and tangible support from extended family) and parental involvement on the relation between exposure to community violence (i.e., witnessing violence and violent victimization) and socioemotional adjustment (i.e., internalizing and externalizing problems) in low-income adolescents. The sample included 312 (50 % female; 71 % African American and 29 % White) low-income youth who participated in a longitudinal investigation when adolescents were age 14 (M age = 14.49 years) and again when they were 16 (M age = 16.49 years). Exposure to community violence at age 14 was related to more internalizing and externalizing problems at age 16. High levels of kinship support and parental involvement appeared to function as protective factors, weakening the association between exposure to violence and externalizing problems. Contrary to prediction, none of the hypothesized protective factors moderated the association between exposure to violence and internalizing problems. The results from this study suggest that both kinship support and parental involvement help buffer adolescents from externalizing problems that are associated with exposure to community violence.

Gene regulatory network inference from multifactorial perturbation data using both regression and correlation analyses.

PubMed

Xiong, Jie; Zhou, Tong

2012-01-01

An important problem in systems biology is to reconstruct gene regulatory networks (GRNs) from experimental data and other a priori information. The DREAM project offers some types of experimental data, such as knockout data, knockdown data, time series data, etc. Among them, multifactorial perturbation data are easier and less expensive to obtain than other types of experimental data and are thus more common in practice. In this article, a new algorithm is presented for the inference of GRNs using the DREAM4 multifactorial perturbation data. The GRN inference problem among [Formula: see text] genes is decomposed into [Formula: see text] different regression problems. In each of the regression problems, the expression level of a target gene is predicted solely from the expression level of a potential regulation gene. For different potential regulation genes, different weights for a specific target gene are constructed by using the sum of squared residuals and the Pearson correlation coefficient. Then these weights are normalized to reflect effort differences of regulating distinct genes. By appropriately choosing the parameters of the power law, we constructe a 0-1 integer programming problem. By solving this problem, direct regulation genes for an arbitrary gene can be estimated. And, the normalized weight of a gene is modified, on the basis of the estimation results about the existence of direct regulations to it. These normalized and modified weights are used in queuing the possibility of the existence of a corresponding direct regulation. Computation results with the DREAM4 In Silico Size 100 Multifactorial subchallenge show that estimation performances of the suggested algorithm can even outperform the best team. Using the real data provided by the DREAM5 Network Inference Challenge, estimation performances can be ranked third. Furthermore, the high precision of the obtained most reliable predictions shows the suggested algorithm may be helpful in guiding biological experiment designs.

SPIR: The potential spreaders involved SIR model for information diffusion in social networks

NASA Astrophysics Data System (ADS)

Rui, Xiaobin; Meng, Fanrong; Wang, Zhixiao; Yuan, Guan; Du, Changjiang

2018-09-01

The Susceptible-Infective-Removed (SIR) model is one of the most widely used models for the information diffusion research in social networks. Many researchers have devoted themselves to improving the classic SIR model in different aspects. However, on the one hand, the equations of these improved models are regarded as continuous functions, while the corresponding simulation experiments use discrete time, leading to the mismatch between numerical solutions got from mathematical method and experimental results obtained by simulating the spreading behaviour of each node. On the other hand, if the equations of these improved models are solved discretely, susceptible nodes will be calculated repeatedly, resulting in a big deviation from the actual value. In order to solve the above problem, this paper proposes a Susceptible-Potential-Infective-Removed (SPIR) model that analyses the diffusion process based on the discrete time according to simulation. Besides, this model also introduces a potential spreader set which solve the problem of repeated calculation effectively. To test the SPIR model, various experiments have been carried out from different angles on both artificial networks and real world networks. The Pearson correlation coefficient between numerical solutions of our SPIR equations and corresponding simulation results is mostly bigger than 0.95, which reveals that the proposed SPIR model is able to depict the information diffusion process with high accuracy.

Things Change, People Change, Libraries Go on: E-books or Not E-books?

NASA Astrophysics Data System (ADS)

Martines, F.

2015-04-01

The aim of this paper is to describe how e-books work and how they can be managed in a scientific or research library; specifically, to discuss the viability of e-lending. The results were a little bit surprising and even slightly confusing. Unquestionably, e-books have enormous potential, but much of this potential is untapped. Although there is widespread awareness of the advantages of e-books among users and librarians, problems and challenges are not as well known. After a discussion of the potential advantages, I will concentrate on some of the real drawbacks of e-books.

Genetic programming and serial processing for time series classification.

PubMed

Alfaro-Cid, Eva; Sharman, Ken; Esparcia-Alcázar, Anna I

2014-01-01

This work describes an approach devised by the authors for time series classification. In our approach genetic programming is used in combination with a serial processing of data, where the last output is the result of the classification. The use of genetic programming for classification, although still a field where more research in needed, is not new. However, the application of genetic programming to classification tasks is normally done by considering the input data as a feature vector. That is, to the best of our knowledge, there are not examples in the genetic programming literature of approaches where the time series data are processed serially and the last output is considered as the classification result. The serial processing approach presented here fills a gap in the existing literature. This approach was tested in three different problems. Two of them are real world problems whose data were gathered for online or conference competitions. As there are published results of these two problems this gives us the chance to compare the performance of our approach against top performing methods. The serial processing of data in combination with genetic programming obtained competitive results in both competitions, showing its potential for solving time series classification problems. The main advantage of our serial processing approach is that it can easily handle very large datasets.

Construction, Part of Indoor Air Quality Design Tools for Schools

EPA Pesticide Factsheets

Poor job-site construction practices can frustrate even the best design by allowing moisture and other contaminants to become potential long term problems. Preventive job-site practices will reduce the potential for residual problems with IAQ

Community Work and Local Authority Decision Making: Potential and Problems

ERIC Educational Resources Information Center

Corina, Lewis

1976-01-01

British local authority and decision making procedures are described for community developers. Included are potential ways of influencing the authority system, and problems and areas of weakness that may be encountered in dealing with the system. (ABM)

Plant Operations. OSHA on Campus: Campus Safety Officers Discuss Problems and Potentials

ERIC Educational Resources Information Center

Kuchta, Joseph F.; And Others

1973-01-01

The Occupation Safety and Health Act (OSHA) has presented campus safety officers with new problems, but it is also offering them new potentials, which were explored at the recent national conference on Campus Security. (Editor)

The continuing problem of missed test results in an integrated health system with an advanced electronic medical record.

PubMed

Wahls, Terry; Haugen, Thomas; Cram, Peter

2007-08-01

Missed results can cause needless treatment delays. However, there is little data about the magnitude of this problem and the systems that clinics use to manage test results. Surveys about potential problems related to test results management were developed and administered to clinical staff in a regional Veterans Administration (VA) health care network. The provider survey, conducted four times between May 2005 and October 2006, sampling VA staff physicians, physician assistants, nurse practitioners, and internal medicine trainees, asked questions about the frequency of missed results and diagnosis or treatment delays seen in the antecedent two weeks in their clinics, or if a trainee, the antecedent month. Clinical staff survey response rate was 39% (143 of 370), with 40% using standard operating procedures to manage test results. Forty-four percent routinely reported all results to patients. The provider survey response rate was 50% (441 of 884) overall, with responses often (37% overall; range 29% to 46%) indicating they had seen patients with diagnosis or treatment delays attributed to a missed result; 15% reported two or more such encounters. Even in an integrated health system with an advanced electronic medical record, missed test results and associated diagnosis or treatment delays are common. Additional study and measures of missed results and associated treatment delays are needed.

Fathers' Rights Groups, Domestic Violence and Political Countermobilization

ERIC Educational Resources Information Center

Crowley, Jocelyn Elise

2009-01-01

Domestic violence continues to be a serious problem for women in the United States. As a result, the battered women's movement has been tireless in campaigning for greater awareness of the issue, tougher penalties against offenders, and public vigilance against potential batterers, including fathers from dissolving families. In reaction to this…

Format Effects of Empirically Derived Multiple-Choice versus Free-Response Instruments When Assessing Graphing Abilities

ERIC Educational Resources Information Center

Berg, Craig; Boote, Stacy

2017-01-01

Prior graphing research has demonstrated that clinical interviews and free-response instruments produce very different results than multiple-choice instruments, indicating potential validity problems when using multiple-choice instruments to assess graphing skills (Berg & Smith in "Science Education," 78(6), 527-554, 1994). Extending…

Enhanced activity of antifungal drugs using natural phenolics against yeast strains of Candida and Cryptococcus

USDA-ARS?s Scientific Manuscript database

Candidiasis and cryptococcosis are diseases of widening global incidence as a result of increasing immunosuppressive disorders, such as AIDS. An enduring problem for treatment of these mycoses is recurrent development of resistance to introduced antifungal drugs. We examined the potential for enhan...

Formalisms for user interface specification and design

NASA Technical Reports Server (NTRS)

Auernheimer, Brent J.

1989-01-01

The application of formal methods to the specification and design of human-computer interfaces is described. A broad outline of human-computer interface problems, a description of the field of cognitive engineering and two relevant research results, the appropriateness of formal specification techniques, and potential NASA application areas are described.

Problems of the Financing of Russian Science

ERIC Educational Resources Information Center

Mindeli, L.; Chernykh, S.

2010-01-01

One of the most important factors that determine the state of science potential and, in the long run, the successful results of scientific and technical activity, is its financing. All developed countries conduct an incentive policy to encourage their national science, including systematic support from state budgets for scientific research and…

Enhancing the Adult Experience: Counseling Approaches and Activities.

ERIC Educational Resources Information Center

Benjamin, Libby; Walz, Garry R.

This document is one of three monographs resulting from a three-year study of adult counseling programs and practices in the United States. The first section of this monograph describes issues and potential problems associated with four frequently-experienced adult life transitions, i.e., divorce, midlife career change, preretirement planning, and…

School and Law Enforcement Efforts to Combat Cyberbullying

ERIC Educational Resources Information Center

Stewart, Daniel M.; Fritsch, Eric J.

2011-01-01

Although most youth have positive experiences while using technology, bullying by electronic means, or cyberbullying, is becoming an increasing problem. Not only does it have the potential to significantly disrupt the educational environment, but it also can result in severe psychological and physical consequences for victims. In this article, the…

Uniform theory of the boundary diffraction wave

NASA Astrophysics Data System (ADS)

Umul, Yusuf Z.

2009-04-01

A uniform version of the potential function of the Maggi-Rubinowicz boundary diffraction wave theory is obtained by using the large argument expansion of the Fresnel integral. The derived function is obtained for the problem of diffraction of plane waves by a circular edge. The results are plotted numerically.

Chaparral & Fire Ecology: Role of Fire in Seed Germination.

ERIC Educational Resources Information Center

Steele, Nancy L. C.; Keeley, Jon E.

1991-01-01

An activity that incorporates the concepts of plant structure and function and ecology is described. Students investigate the reasons why some California chaparral seeds germinate only after a fire has burned the surrounding chaparral. The procedure, discussion and analysis questions, expected results, potential problems, and additional activities…

Observations of sea ice and icebergs from satellite radar altimeters

NASA Technical Reports Server (NTRS)

Rapley, C. G.

1984-01-01

Satellite radar altimeters can make useful contributions to the study of sea ice both by enhancing observations from other instruments and by providing a unique probe of ocean-ice interaction in the Marginal Ice Zone (MIZ). The problems, results and future potential of such observations are discussed.

Overeducation Dynamics and Personality

ERIC Educational Resources Information Center

Blazquez, Maite; Budria, Santiago

2012-01-01

In this paper, we use the 2000-2008 waves of the German Socioeconomic Panel to examine overeducation transitions. The results are based on a first-order Markov model that allows us to account for both the initial conditions problem and potential endogeneity in attrition. We found that overeducation dynamics, especially the probability of entering…

Plastics in the Ocean: More Than a Litter Problem.

ERIC Educational Resources Information Center

Center for Environmental Education, Washington, DC.

Environmental impacts arise from entanglement of marine animals in plastic debris and from ingestion of plastics by marine organisms. Plastic debris can cause potential threats to humans when divers become entangled or vessels become fouled in debris. The depletion of fishery resources, vessel damage, and aesthetic degradation resulting in lost…

Office Hours as You Like Them: Integrating Real-Time Chats into the Course Media Mix.

ERIC Educational Resources Information Center

McKeage, Kim

2001-01-01

Reports on one professor's use of integrated synchronous electronic office hours (i.e., a "chat room") with asynchronous course conferencing (i.e., email) in a class on introductory marketing. Describes its uses, limitations, benefits, potential problems, and results from a student survey. (EV)

The Expected Personality Characteristics of Alcohol-Dependent Individuals.

ERIC Educational Resources Information Center

Malouff, John M.; Schutte, Nicola S.

2002-01-01

Uses the Big Five personality factors as a framework for examining the expected personality characteristics of individuals who are alcohol-dependent. Results help explain prior findings about the social handicap of problem drinking with regard to making friends, dating, marriage, and working. Findings have potential use in alcohol-problem…

Projective Item Response Model for Test-Independent Measurement

ERIC Educational Resources Information Center

Ip, Edward Hak-Sing; Chen, Shyh-Huei

2012-01-01

The problem of fitting unidimensional item-response models to potentially multidimensional data has been extensively studied. The focus of this article is on response data that contains a major dimension of interest but that may also contain minor nuisance dimensions. Because fitting a unidimensional model to multidimensional data results in…

Reciprocal relationships between parent and adolescent internalizing symptoms.

PubMed

Hughes, Elizabeth K; Gullone, Eleonora

2010-04-01

Previous investigations of the association between parent and adolescent internalizing problems have been largely restricted to the unidirectional effect of parent symptoms on their children. This study therefore aimed to investigate potential reciprocal relationships between parent and adolescent internalizing symptoms. One-hundred and seventy-seven adolescents ages 14 to 18 years and their parents (172 mothers, 124 fathers) completed measures of depressive and anxiety symptoms at two time points, 6 months apart. Results supported reciprocity between maternal and adolescent internalizing symptoms but not between paternal and adolescent internalizing symptoms. In addition, the relationship between maternal symptoms and later adolescent symptoms was found to be partially mediated by maternal parenting self-esteem. The study highlights the potential impact of adolescent internalizing problems on maternal well-being, a phenomenon previously neglected in the literature. 2010 APA, all rights reserved

Algorithm for covert convoy of a moving target using a group of autonomous robots

NASA Astrophysics Data System (ADS)

Polyakov, Igor; Shvets, Evgeny

2018-04-01

An important application of autonomous robot systems is to substitute human personnel in dangerous environments to reduce their involvement and subsequent risk on human lives. In this paper we solve the problem of covertly convoying a civilian in a dangerous area with a group of unmanned ground vehicles (UGVs) using social potential fields. The novelty of our work lies in the usage of UGVs as compared to the unmanned aerial vehicles typically employed for this task in the approaches described in literature. Additionally, in our paper we assume that the group of UGVs should simultaneously solve the problem of patrolling to detect intruders on the area. We develop a simulation system to test our algorithms, provide numerical results and give recommendations on how to tune the potentials governing robots' behaviour to prioritize between patrolling and convoying tasks.

Developing image processing meta-algorithms with data mining of multiple metrics.

PubMed

Leung, Kelvin; Cunha, Alexandre; Toga, A W; Parker, D Stott

2014-01-01

People often use multiple metrics in image processing, but here we take a novel approach of mining the values of batteries of metrics on image processing results. We present a case for extending image processing methods to incorporate automated mining of multiple image metric values. Here by a metric we mean any image similarity or distance measure, and in this paper we consider intensity-based and statistical image measures and focus on registration as an image processing problem. We show how it is possible to develop meta-algorithms that evaluate different image processing results with a number of different metrics and mine the results in an automated fashion so as to select the best results. We show that the mining of multiple metrics offers a variety of potential benefits for many image processing problems, including improved robustness and validation.

Financial Management: Education's Financial Management Problems Persist. Testimony before the Task Force on Education, Committee on the Budget, House of Representatives.

ERIC Educational Resources Information Center

Jarmon, Gloria L.; Engel, Gary T.

This document discusses the Department of Education's (DOE) fiscal year 1999 financial audit results; the relationship between the audit findings and the potential for waste, fraud, and abuse; and the results of the General Accounting Office's (GAO) review of the DOE's grantback account. The DOE's financial activity is important to the federal…

A Case Study Using Modeling and Simulation to Predict Logistics Supply Chain Issues

NASA Technical Reports Server (NTRS)

Tucker, David A.

2007-01-01

Optimization of critical supply chains to deliver thousands of parts, materials, sub-assemblies, and vehicle structures as needed is vital to the success of the Constellation Program. Thorough analysis needs to be performed on the integrated supply chain processes to plan, source, make, deliver, and return critical items efficiently. Process modeling provides simulation technology-based, predictive solutions for supply chain problems which enable decision makers to reduce costs, accelerate cycle time and improve business performance. For example, United Space Alliance, LLC utilized this approach in late 2006 to build simulation models that recreated shuttle orbiter thruster failures and predicted the potential impact of thruster removals on logistics spare assets. The main objective was the early identification of possible problems in providing thruster spares for the remainder of the Shuttle Flight Manifest. After extensive analysis the model results were used to quantify potential problems and led to improvement actions in the supply chain. Similarly the proper modeling and analysis of Constellation parts, materials, operations, and information flows will help ensure the efficiency of the critical logistics supply chains and the overall success of the program.

A fully implicit finite element method for bidomain models of cardiac electromechanics

PubMed Central

Dal, Hüsnü; Göktepe, Serdar; Kaliske, Michael; Kuhl, Ellen

2012-01-01

We propose a novel, monolithic, and unconditionally stable finite element algorithm for the bidomain-based approach to cardiac electromechanics. We introduce the transmembrane potential, the extracellular potential, and the displacement field as independent variables, and extend the common two-field bidomain formulation of electrophysiology to a three-field formulation of electromechanics. The intrinsic coupling arises from both excitation-induced contraction of cardiac cells and the deformation-induced generation of intra-cellular currents. The coupled reaction-diffusion equations of the electrical problem and the momentum balance of the mechanical problem are recast into their weak forms through a conventional isoparametric Galerkin approach. As a novel aspect, we propose a monolithic approach to solve the governing equations of excitation-contraction coupling in a fully coupled, implicit sense. We demonstrate the consistent linearization of the resulting set of non-linear residual equations. To assess the algorithmic performance, we illustrate characteristic features by means of representative three-dimensional initial-boundary value problems. The proposed algorithm may open new avenues to patient specific therapy design by circumventing stability and convergence issues inherent to conventional staggered solution schemes. PMID:23175588

The Current State of Drug Discovery and a Potential Role for NMR Metabolomics

PubMed Central

2015-01-01

The pharmaceutical industry has significantly contributed to improving human health. Drugs have been attributed to both increasing life expectancy and decreasing health care costs. Unfortunately, there has been a recent decline in the creativity and productivity of the pharmaceutical industry. This is a complex issue with many contributing factors resulting from the numerous mergers, increase in out-sourcing, and the heavy dependency on high-throughput screening (HTS). While a simple solution to such a complex problem is unrealistic and highly unlikely, the inclusion of metabolomics as a routine component of the drug discovery process may provide some solutions to these problems. Specifically, as the binding affinity of a chemical lead is evolved during the iterative structure-based drug design process, metabolomics can provide feedback on the selectivity and the in vivo mechanism of action. Similarly, metabolomics can be used to evaluate and validate HTS leads. In effect, metabolomics can be used to eliminate compounds with potential efficacy and side effect problems while prioritizing well-behaved leads with druglike characteristics. PMID:24588729

Decisions to Attend and Drink at Party Events: The Effects of Incentives and Disincentives and Lifetime Alcohol and Antisocial Problems.

PubMed

Finn, Peter R; Gerst, Kyle; Lake, Allison; Bogg, Tim

2017-09-01

Alcohol use disorders are associated with patterns of impulsive/risky decision making on behavioral economic decision tasks, but little is known about the factors affecting drinking-related decisions. The effects of incentives and disincentives to attend and drink at hypothetical alcohol-related party events as a function of lifetime (LT) alcohol and antisocial problems were examined in a sample of 434 young adults who varied widely in LT alcohol and antisocial problems. Moderate and high disincentives substantially discouraged decisions to attend the party events and were associated with decisions to drink less at the party events. High versus low party incentives were associated with more attendance decisions. LT antisocial problems were associated with being less deterred from attending by moderate and high disincentives. LT alcohol problems were associated with greater attendance at high party incentive contexts. LT alcohol problems were associated with drinking more at the majority of events; however, the results indicate that young adults with high levels of alcohol problems moderate their drinking in response to moderate and high disincentives. Finally, attendance and drinking decisions on this hypothetical task were significantly related to actual drinking practices. The results suggest that antisocial symptoms are associated with a reduced sensitivity to the potential negative consequences of drinking, while alcohol problems are associated with a greater sensitivity to the rewarding aspects of partying. The results also underline the value of directly assessing drinking-related decisions in different hypothetical contexts as well as assessing decisions about attendance at risky drinking events in addition to drinking amount decisions. Copyright © 2017 by the Research Society on Alcoholism.

The population problem: conceptions and misconceptions.

PubMed

Berelson, B

1971-01-01

Only 1 in about 110 sex acts results in a conception and 1 in 270 in a live birth. Of all conceptions, 40% result in live births, 5% in stillbirths, and 55% never develop. 1/3 of all known conceptions ends in abortion, spontaneous or induced. It appears that the population problem depends on a small fraction of the potential. Misconceptions of the problem are corrected, and it is emphasized that while no social problem facing the U.S. would be easier with a larger population, demographic factors do not cause all of the other problems. Increasing numbers are not as important as the rate of increase (2% annually worldwide). Today's population problem has been caused by a decreased death rate, not an increased birthrate. There are 2 kinds of countries in the world today: those with a high standard of living and low fertility and those with a low standard of living and high fertility. Most of the uninformed women of the world would not choose to have large numbers of children if they had a choice. Population density is not a problem in itself. Experts disagree, but it is improbable that large numbers of people will die of starvation in the next few decades. Environmental deterioration is more the result of modern economic and technological practices than of demographic factors. Efforts at fertility control are not aimed at minorities in this country and elsewhere. The poor are discriminated against in access to family planning services and abortion. Moslems of developing countries have higher fertility rates than Roman Catholics in developed countries. There would be many social costs if the U.S. were to achieve zero population growth in the near future. The population problem has implications for the future quality of life.

Electron scattering from excited states of hydrogen: Implications for the ionization threshold law

NASA Astrophysics Data System (ADS)

Temkin, A.; Shertzer, J.

2013-05-01

The elastic scattering wave function for electrons scattered from the Nth excited state of hydrogen is the final state of the matrix element for excitation of that state. This paper deals with the solution of that problem primarily in the context of the Temkin-Poet (TP) model [A. Temkin, Phys. Rev.PHRVAO0031-899X10.1103/PhysRev.126.130 126, 130 (1962); R. Poet, J. Phys. BJPAPEH0022-370010.1088/0022-3700/11/17/019 11, 3081 (1978)], wherein only the radial parts of the interaction are included. The relevant potential for the outer electron is dominated by the Hartree potential, VNH(r). In the first part of the paper, VNH(r) is approximated by a potential WN(r), for which the scattering equation can be analytically solved. The results allow formal analytical continuation of N into the continuum, so that the ionization threshold law can be deduced. Because the analytic continuation involves going from N to an imaginary function of the momentum of the inner electron, the threshold law turns out to be an exponentially damped function of the available energy E, in qualitative accord with the result of Macek and Ihra [J. H. Macek and W. Ihra, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.55.2024 55, 2024 (1997)] for the TP model. Thereafter, the scattering equation for the Hartree potential VNH(r) is solved numerically. The numerical aspects of these calculations have proven to be challenging and required several developments for the difficulties to be overcome. The results for VNH(r) show only a simple energy-dependent shift from the approximate potential WN(r), which therefore does not change the analytic continuation and the form of the threshold law. It is concluded that the relevant optical potential must be included in order to compare directly with the analytic result of Macek and Ihra. The paper concludes with discussions of (a) a quantum mechanical interpretation of the result, and (b) the outlook of this approach for the complete problem.

Cardiac Position Sensitivity Study in the Electrocardiographic Forward Problem Using Stochastic Collocation and Boundary Element Methods

PubMed Central

Swenson, Darrell J.; Geneser, Sarah E.; Stinstra, Jeroen G.; Kirby, Robert M.; MacLeod, Rob S.

2012-01-01

The electrocardiogram (ECG) is ubiquitously employed as a diagnostic and monitoring tool for patients experiencing cardiac distress and/or disease. It is widely known that changes in heart position resulting from, for example, posture of the patient (sitting, standing, lying) and respiration significantly affect the body-surface potentials; however, few studies have quantitatively and systematically evaluated the effects of heart displacement on the ECG. The goal of this study was to evaluate the impact of positional changes of the heart on the ECG in the specific clinical setting of myocardial ischemia. To carry out the necessary comprehensive sensitivity analysis, we applied a relatively novel and highly efficient statistical approach, the generalized polynomial chaos-stochastic collocation method, to a boundary element formulation of the electrocardiographic forward problem, and we drove these simulations with measured epicardial potentials from whole-heart experiments. Results of the analysis identified regions on the body-surface where the potentials were especially sensitive to realistic heart motion. The standard deviation (STD) of ST-segment voltage changes caused by the apex of a normal heart, swinging forward and backward or side-to-side was approximately 0.2 mV. Variations were even larger, 0.3 mV, for a heart exhibiting elevated ischemic potentials. These variations could be large enough to mask or to mimic signs of ischemia in the ECG. Our results suggest possible modifications to ECG protocols that could reduce the diagnostic error related to postural changes in patients possibly suffering from myocardial ischemia. PMID:21909818

Optimized effective potential in real time: Problems and prospects in time-dependent density-functional theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mundt, Michael; Kuemmel, Stephan

2006-08-15

The integral equation for the time-dependent optimized effective potential (TDOEP) in time-dependent density-functional theory is transformed into a set of partial-differential equations. These equations only involve occupied Kohn-Sham orbitals and orbital shifts resulting from the difference between the exchange-correlation potential and the orbital-dependent potential. Due to the success of an analog scheme in the static case, a scheme that propagates orbitals and orbital shifts in real time is a natural candidate for an exact solution of the TDOEP equation. We investigate the numerical stability of such a scheme. An approximation beyond the Krieger-Li-Iafrate approximation for the time-dependent exchange-correlation potential ismore » analyzed.« less

Polygenic Risk, Personality Dimensions, and Adolescent Alcohol Use Problems: A Longitudinal Study

PubMed Central

Li, James J.; Savage, Jeanne E.; Kendler, Kenneth S.; Hickman, Matthew; Mahedy, Liam; Macleod, John; Kaprio, Jaakko; Rose, Richard J.; Dick, Danielle M.

2017-01-01

Objective: Alcohol use problems are common during adolescence and can predict serious negative outcomes in adulthood, including substance dependence and psychopathology. The current study examines the notion that alcohol use problems are driven by polygenic influences and that genetic influences may indirectly affect alcohol use problems through multiple pathways of risk, including variations in personality. Method: We used a genome-wide approach to examine associations between genetic risk for alcohol use problems, personality dimensions, and adolescent alcohol use problems in two separate longitudinal population-based samples, the Finnish Twin Cohort (FinnTwin12) and the Avon Longitudinal Study of Parents and Children (ALSPAC). Participants were 1,035 young adults from FinnTwin12 and 3,160 adolescents from ALSPAC. Polygenic risk scores (PRS) were calculated for ALSPAC using genome-wide association results (on alcohol dependence symptoms as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) from FinnTwin12. A parallel multiple mediator model was tested to examine whether the association between PRS and alcohol use problems assessed at age 16 could be explained by variations in personality dimensions assessed at age 13, including sensation seeking and negative emotionality. Results: PRS were marginally predictive of age 16 alcohol use problems; this association was partially mediated by sensation seeking. Polygenic variation underlying risk for alcohol use problems may directly influence the effects of sensation seeking, which in turn influence the development of alcohol use problems in later adolescence. Conclusions: These findings contribute to the increasing evidence regarding the salience of sensation seeking during early adolescence as a potential constituent in the risk pathway underlying the development of alcohol use problems. PMID:28499112

Have you been sexually harassed in school? What female high school students regard as harassment.

PubMed

Witkowska, Eva; Gillander Gådin, Katja

2005-01-01

The aim of the study was to explore what behaviors experienced from peers and school staff at school are acknowledged as sexual harassment, and perceived as problematic, by female high school students, and what other factors may be relevant. Analyses were performed of responses (to 540 questionnaires) in an anonymous self-report mail survey from a random sample of female Swedish high-school students (59% response rate). Exposure to relevant behaviors, of varying levels of severity, alone, does not explain the acknowledgment of harassment. Many students were subjected to many of the potentially offensive behaviors without labeling them as sexual harassment, despite the fact that they saw many of them as problematic. Further, viewing the relevant behaviors as problems in one's school did not necessarily lead to acknowledging that sexual harassment in general was a problem. However, the behaviors seen as problems were less likely to be dismissed as sexual harassment than personal experiences. This was especially true of the most common behaviors, namely verbal ones. The results demonstrate female students' reluctance to label incidents as sexual harassment, despite the fact that actual behaviors are perceived as environmental problems. Potentially offensive sex-related behaviors become normalized in the school environment and are difficult to address, when little support is provided by schools.

Managing the Budget: Stock-Flow Reasoning and the CO2 Accumulation Problem.

PubMed

Newell, Ben R; Kary, Arthur; Moore, Chris; Gonzalez, Cleotilde

2016-01-01

The majority of people show persistent poor performance in reasoning about "stock-flow problems" in the laboratory. An important example is the failure to understand the relationship between the "stock" of CO2 in the atmosphere, the "inflow" via anthropogenic CO2 emissions, and the "outflow" via natural CO2 absorption. This study addresses potential causes of reasoning failures in the CO2 accumulation problem and reports two experiments involving a simple re-framing of the task as managing an analogous financial (rather than CO2 ) budget. In Experiment 1 a financial version of the task that required participants to think in terms of controlling debt demonstrated significant improvements compared to a standard CO2 accumulation problem. Experiment 2, in which participants were invited to think about managing savings, suggested that this improvement was fortuitous and coincidental rather than due to a fundamental change in understanding the stock-flow relationships. The role of graphical information in aiding or abetting stock-flow reasoning was also explored in both experiments, with the results suggesting that graphs do not always assist understanding. The potential for leveraging the kind of reasoning exhibited in such tasks in an effort to change people's willingness to reduce CO2 emissions is briefly discussed. Copyright © 2015 Cognitive Science Society, Inc.

Experimenting in a constructivist high school physics laboratory

NASA Astrophysics Data System (ADS)

Roth, Wolff-Michael

Although laboratory activities have long been recognized for their potential to facilitate the learning of science concepts and skills, this potential has yet to be realized. To remediate this problem, researchers have called for constructivist learning environments in which students can pursue open inquiry and frame their own research problems. The present study was designed to describe and understand students' experimenting and problem solving in such an environment. An interpretive research methodology was adopted for the construction of meaning from the data. The data sources included videotapes, their transcripts, student laboratory reports and reflections, interviews with the students, and the teacher's course outline and reflective notes. Forty-six students from three sections of an introductory physics course taught at a private school for boys participated in the study. This article shows the students' remarkable ability and willingness to generate research questions and to design and develop apparatus for data collection. In their effort to frame research questions, students often used narrative explanations to explore and think about the phenomena to be studied. In some cases, blind alleys, students framed research questions and planned experiments that did not lead to the expected results. We observed a remarkable flexibility to deal with problems that arose during the implementation of their plans in the context of the inquiry. These problems, as well as their solutions and the necessary decision-making processes, were characterized by their situated nature. Finally, students pursued meaningful learning during the interpretation of data and graphs to arrive at reasonable answers of their research questions. We concluded that students should be provided with problem-rich learning environments in which they learn to investigate phenomena of their own interest and in which they can develop complex problem-solving skills.

Confusing Aspects in the Calculation of the Electrostatic Potential of an Infinite Line of Charge

ERIC Educational Resources Information Center

Jimenez, J. L.; Campos, I.; Roa-Neri, J. A. E.

2012-01-01

In this work we discuss the trick of eliminating infinite potential of reference arguing that it corresponds to a constant of integration, in the problem of determining the electrostatic potential of an infinite line of charge with uniform density, and show how the problem must be tackled properly. The usual procedure is confusing for most…

Associations between depression, distress tolerance, delay discounting, and alcohol-related problems in European American and African American college students.

PubMed

Dennhardt, Ashley A; Murphy, James G

2011-12-01

Although levels of heavy drinking and alcohol-related problems are high in college students, there is significant variability in the number and type of problems experienced, even among students who drink heavily. African American students drink less and experience fewer alcohol-related problems than European American students, but are still at risk, and little research has investigated the potentially unique patterns and predictors of problems among these students. Depression, distress tolerance, and delay discounting have been implicated in adult substance abuse and may be important predictors of alcohol problem severity among college students. We examined the relationship between these variables and alcohol-related problems among African American and European American students (N = 206; 53% female; 68% European American; 28% African American) who reported recent heavy drinking. In regression models that controlled for drinking level, depression, distress tolerance, and delay discounting were associated with alcohol problems among African American students, but only depression was associated with alcohol problems among European American students. These results suggest that negative affect is a key risk factor for alcohol problems among college student drinkers. For African American students, the inability to tolerate negative emotions and to organize their behavior around future outcomes may also be especially relevant risk factors.

[From persistence to symbiosis of microorganisms].

PubMed

Bukharin, O V

2012-01-01

Primary results of study of problem of microorganism persistence over the last 2 decades on 7 all-Russian conferences in Orenburg are examined in the article. Milestones of both fundamental research and practically significant studies are designated, the role of persistent potential of microorganisms in infectious pathology is evaluated. The emerging turn of studies from persistence to symbiosis is consonant with the idea of international project "Human microbiom" and allows to use the persistent potential of microorganisms as one of the instruments of resolving issues of infectology.

Hip Arthroscopy: Common Problems and Solutions.

PubMed

Casp, Aaron; Gwathmey, Frank Winston

2018-04-01

The use of hip arthroscopy continues to expand. Understanding potential pitfalls and complications associated with hip arthroscopy is paramount to optimizing clinical outcomes and minimizing unfavorable results. Potential pitfalls and complications are associated with preoperative factors such as patient selection, intraoperative factors such as iatrogenic damage, traction-related complications, inadequate correction of deformity, and nerve injury, or postoperative factors such as poor rehabilitation. This article outlines common factors that contribute to less-than-favorable outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

Impacts of supersymmetric higher derivative terms on inflation models in supergravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aoki, Shuntaro; Yamada, Yusuke, E-mail: shun-soccer@akane.waseda.jp, E-mail: yuusuke-yamada@asagi.waseda.jp

2015-07-01

We show the effects of supersymmetric higher derivative terms on inflation models in supergravity. The results show that such terms generically modify the effective kinetic coefficient of the inflaton during inflation if the cut off scale of the higher derivative operators is sufficiently small. In such a case, the η-problem in supergravity does not occur, and we find that the effective potential of the inflaton generically becomes a power type potential with a power smaller than two.

Radion tunneling in modified theories of gravity

NASA Astrophysics Data System (ADS)

Paul, Tanmoy; SenGupta, Soumitra

2018-04-01

We consider a five dimensional warped spacetime where the bulk geometry is governed by higher curvature F( R) gravity. In this model, we determine the modulus potential originating from the scalar degree of freedom of higher curvature gravity. In the presence of this potential, we investigate the possibility of modulus (radion) tunneling leading to an instability in the brane configuration. Our results reveal that the parametric regions where the tunneling probability is highly suppressed, corresponds to the parametric values required to resolve the gauge hierarchy problem.

Integrated study plan for space bioprocessing (phase 1)

NASA Technical Reports Server (NTRS)

1977-01-01

Current economic evaluation and analytical techniques are applied to decision problems faced by the space bioprocessing program. NASA decision makers are enabled to choose candidate substances, after ranking them according to their potential economic benefit. The determination of appropriate evaluation techniques necessary to obtain measures of potential economic benefits which result from the pursuit of various space bioprocessing endeavors are focused upon. The treatment of each disease is impacted by a successful outcome of space bioprocessing and specify data and other input needs for each candidate substance.

Sparse radar imaging using 2D compressed sensing

NASA Astrophysics Data System (ADS)

Hou, Qingkai; Liu, Yang; Chen, Zengping; Su, Shaoying

2014-10-01

Radar imaging is an ill-posed linear inverse problem and compressed sensing (CS) has been proved to have tremendous potential in this field. This paper surveys the theory of radar imaging and a conclusion is drawn that the processing of ISAR imaging can be denoted mathematically as a problem of 2D sparse decomposition. Based on CS, we propose a novel measuring strategy for ISAR imaging radar and utilize random sub-sampling in both range and azimuth dimensions, which will reduce the amount of sampling data tremendously. In order to handle 2D reconstructing problem, the ordinary solution is converting the 2D problem into 1D by Kronecker product, which will increase the size of dictionary and computational cost sharply. In this paper, we introduce the 2D-SL0 algorithm into the reconstruction of imaging. It is proved that 2D-SL0 can achieve equivalent result as other 1D reconstructing methods, but the computational complexity and memory usage is reduced significantly. Moreover, we will state the results of simulating experiments and prove the effectiveness and feasibility of our method.

Playing Video Games While Using or Feeling the Effects of Substances: Associations with Substance Use Problems

PubMed Central

Ream, Geoffrey L.; Elliott, Luther C.; Dunlap, Eloise

2011-01-01

This study tested the hypothesis that playing video games while using or feeling the effects of a substance—referred to herein as “concurrent use”—is related to substance use problems after controlling for substance use frequency, video gaming as an enthusiastic hobby, and demographic factors. Data were drawn from a nationally representative online survey of adult video gamers conducted by Knowledge Networks, valid n = 2,885. Problem video game playing behavior was operationalized using Tejeiro Salguero and Bersabé Morán’s 2002 problem video game play (PVP) measure, and measures for substance use problems were taken from the National Survey of Drug Use and Health (NSDUH). Separate structural equation modeling analyses were conducted for users of caffeine, tobacco, alcohol, and marijuana. In all four models, concurrent use was directly associated with substance use problems, but not with PVP. Video gaming as an enthusiastic hobby was associated with substance use problems via two indirect paths: through PVP for all substances, and through concurrent use for caffeine, tobacco, and alcohol only. Results illustrate the potential for “drug interaction” between self-reinforcing behaviors and addictive substances, with implications for the development of problem use. PMID:22073023

Playing video games while using or feeling the effects of substances: associations with substance use problems.

PubMed

Ream, Geoffrey L; Elliott, Luther C; Dunlap, Eloise

2011-10-01

This study tested the hypothesis that playing video games while using or feeling the effects of a substance--referred to herein as "concurrent use"-is related to substance use problems after controlling for substance use frequency, video gaming as an enthusiastic hobby, and demographic factors. Data were drawn from a nationally representative online survey of adult video gamers conducted by Knowledge Networks, valid n = 2,885. Problem video game playing behavior was operationalized using Tejeiro Salguero and Bersabé Morán's 2002 problem video game play (PVP) measure, and measures for substance use problems were taken from the National Survey of Drug Use and Health (NSDUH). Separate structural equation modeling analyses were conducted for users of caffeine, tobacco, alcohol, and marijuana. In all four models, concurrent use was directly associated with substance use problems, but not with PVP. Video gaming as an enthusiastic hobby was associated with substance use problems via two indirect paths: through PVP for all substances, and through concurrent use for caffeine, tobacco, and alcohol only. Results illustrate the potential for "drug interaction" between self-reinforcing behaviors and addictive substances, with implications for the development of problem use.

Cognitive functioning and social problem-solving skills in schizophrenia.

PubMed

Hatashita-Wong, Michi; Smith, Thomas E; Silverstein, Steven M; Hull, James W; Willson, Deborah F

2002-05-01

This study examined the relationships between symptoms, cognitive functioning, and social skill deficits in schizophrenia. Few studies have incorporated measures of cognitive functioning and symptoms in predictive models for social problem solving. For our study, 44 participants were recruited from consecutive outpatient admissions. Neuropsychological tests were given to assess cognitive function, and social problem solving was assessed using structured vignettes designed to evoke the participant's ability to generate, evaluate, and apply solutions to social problems. A sequential model-fitting method of analysis was used to incorporate social problem solving, symptom presentation, and cognitive impairment into linear regression models. Predictor variables were drawn from demographic, cognitive, and symptom domains. Because this method of analysis was exploratory and not intended as hierarchical modelling, no a priori hypotheses were proposed. Participants with higher scores on tests of cognitive flexibility were better able to generate accurate, appropriate, and relevant responses to the social problem-solving vignettes. The results suggest that cognitive flexibility is a potentially important mediating factor in social problem-solving competence. While other factors are related to social problem-solving skill, this study supports the importance of cognition and understanding how it relates to the complex and multifaceted nature of social functioning.

A new non-iterative reconstruction method for the electrical impedance tomography problem

NASA Astrophysics Data System (ADS)

Ferreira, A. D.; Novotny, A. A.

2017-03-01

The electrical impedance tomography (EIT) problem consists in determining the distribution of the electrical conductivity of a medium subject to a set of current fluxes, from measurements of the corresponding electrical potentials on its boundary. EIT is probably the most studied inverse problem since the fundamental works by Calderón from the 1980s. It has many relevant applications in medicine (detection of tumors), geophysics (localization of mineral deposits) and engineering (detection of corrosion in structures). In this work, we are interested in reconstructing a number of anomalies with different electrical conductivity from the background. Since the EIT problem is written in the form of an overdetermined boundary value problem, the idea is to rewrite it as a topology optimization problem. In particular, a shape functional measuring the misfit between the boundary measurements and the electrical potentials obtained from the model is minimized with respect to a set of ball-shaped anomalies by using the concept of topological derivatives. It means that the objective functional is expanded and then truncated up to the second order term, leading to a quadratic and strictly convex form with respect to the parameters under consideration. Thus, a trivial optimization step leads to a non-iterative second order reconstruction algorithm. As a result, the reconstruction process becomes very robust with respect to noisy data and independent of any initial guess. Finally, in order to show the effectiveness of the devised reconstruction algorithm, some numerical experiments into two spatial dimensions are presented, taking into account total and partial boundary measurements.

Novel probabilistic neuroclassifier

NASA Astrophysics Data System (ADS)

Hong, Jiang; Serpen, Gursel

2003-09-01

A novel probabilistic potential function neural network classifier algorithm to deal with classes which are multi-modally distributed and formed from sets of disjoint pattern clusters is proposed in this paper. The proposed classifier has a number of desirable properties which distinguish it from other neural network classifiers. A complete description of the algorithm in terms of its architecture and the pseudocode is presented. Simulation analysis of the newly proposed neuro-classifier algorithm on a set of benchmark problems is presented. Benchmark problems tested include IRIS, Sonar, Vowel Recognition, Two-Spiral, Wisconsin Breast Cancer, Cleveland Heart Disease and Thyroid Gland Disease. Simulation results indicate that the proposed neuro-classifier performs consistently better for a subset of problems for which other neural classifiers perform relatively poorly.

Modeling behavioral reactivity to losses and rewards on the Balloon Analogue Risk Task (BART): moderation by alcohol problem severity.

PubMed

Ashenhurst, James R; Bujarski, Spencer; Jentsch, J David; Ray, Lara A

2014-08-01

The relationship between risk-taking behavior and substance dependence has proven to be complex, particularly when examining across participants expressing a range of substance use problem severity. While main indices of risk-taking in the Balloon Analogue Risk Task (BART) positively associate with problematic alcohol use in adolescent populations (e.g., MacPherson, Magidson, Reynolds, Kahler, & Lejuez, 2010), several studies have observed a negative relationship when examining behavior within adult substance using populations (Ashenhurst, Jentsch, & Ray, 2011; Campbell, Samartgis, & Crowe, 2013). To examine potential mechanisms that underlie this negative relationship, we implemented multilevel regression models on trial-by-trial BART data gathered from 295 adult problem drinkers. These models accounted for participant behavior on trials following balloon bursts or cash outs as indices of loss and reward reactivity, respectively, and included control variables including age, IQ, and individual delay discounting rate. Results revealed that individual trial pumping was significantly predicted by trial number, and by whether or not the previous trial was a big burst or a big cash out (i.e., large magnitude of potential gains) in a manner consistent with a "near-miss" effect. Furthermore, severity of alcohol problems moderated the effect of a previous trial big burst, but not of a big cash out, on subsequent trial behavior such that those with greater severity demonstrated relative insensitivity to this "near-miss" effect. These results extend previous studies suggesting that alcohol abusers are less risky on the BART by specifying a mechanism underlying this pattern, namely, diminished reactivity to large magnitude losses.

Integrative Potential of Architectural Activities

NASA Astrophysics Data System (ADS)

Davydova, O. V.

2017-11-01

The architectural activity integrative potential is considered through the combination as well as the organization of necessary universal human and professional, artificial and natural, social and individual architectural activities in the multidimensional unity of its components reflecting and influencing the public thinking with the artistic-figurative language of international communication using experimental form-building, interactive presentations, theatrical and gaming expressiveness to organize an easier contact with the consumer, methods of design and advertising. The methodology is used to reflect the mutual influence of personal and social problems through globalization and identification of their problem in the public, to study the existing methods of the problem solving, to analyze their effectiveness, to search for actual problems and new solutions to them using the latest achievements of technological progress, artistic patterns, creation of a holistic architectural image reflecting the author’s worldview in the general picture of the modern world with its inherent tendencies “Surah” and “entertainment”. The operative communication means in the chain of social experience are developed - the teacher - the trainee - the new educational result used to transmit the updated information in a generalized form, the current and final control through the use of feedback sheets, supporting summaries, info cards, its decisions. The paper considers the study time efficiency due to the organization of the research activity which allows students to obtain a theoretical generalized information (the creator’s limitation) in the process of filling or compiling informative and diagnostic maps that provide the theoretical framework for the creative activity through gaming activity that turns into a work activity which has a diagnosed result.

A methodology for constraining power in finite element modeling of radiofrequency ablation.

PubMed

Jiang, Yansheng; Possebon, Ricardo; Mulier, Stefaan; Wang, Chong; Chen, Feng; Feng, Yuanbo; Xia, Qian; Liu, Yewei; Yin, Ting; Oyen, Raymond; Ni, Yicheng

2017-07-01

Radiofrequency ablation (RFA) is a minimally invasive thermal therapy for the treatment of cancer, hyperopia, and cardiac tachyarrhythmia. In RFA, the power delivered to the tissue is a key parameter. The objective of this study was to establish a methodology for the finite element modeling of RFA with constant power. Because of changes in the electric conductivity of tissue with temperature, a nonconventional boundary value problem arises in the mathematic modeling of RFA: neither the voltage (Dirichlet condition) nor the current (Neumann condition), but the power, that is, the product of voltage and current was prescribed on part of boundary. We solved the problem using Lagrange multiplier: the product of the voltage and current on the electrode surface is constrained to be equal to the Joule heating. We theoretically proved the equality between the product of the voltage and current on the surface of the electrode and the Joule heating in the domain. We also proved the well-posedness of the problem of solving the Laplace equation for the electric potential under a constant power constraint prescribed on the electrode surface. The Pennes bioheat transfer equation and the Laplace equation for electric potential augmented with the constraint of constant power were solved simultaneously using the Newton-Raphson algorithm. Three problems for validation were solved. Numerical results were compared either with an analytical solution deduced in this study or with results obtained by ANSYS or experiments. This work provides the finite element modeling of constant power RFA with a firm mathematical basis and opens pathway for achieving the optimal RFA power. Copyright © 2016 John Wiley & Sons, Ltd.

Genome-wide detection of intervals of genetic heterogeneity associated with complex traits

PubMed Central

Llinares-López, Felipe; Grimm, Dominik G.; Bodenham, Dean A.; Gieraths, Udo; Sugiyama, Mahito; Rowan, Beth; Borgwardt, Karsten

2015-01-01

Motivation: Genetic heterogeneity, the fact that several sequence variants give rise to the same phenotype, is a phenomenon that is of the utmost interest in the analysis of complex phenotypes. Current approaches for finding regions in the genome that exhibit genetic heterogeneity suffer from at least one of two shortcomings: (i) they require the definition of an exact interval in the genome that is to be tested for genetic heterogeneity, potentially missing intervals of high relevance, or (ii) they suffer from an enormous multiple hypothesis testing problem due to the large number of potential candidate intervals being tested, which results in either many false positives or a lack of power to detect true intervals. Results: Here, we present an approach that overcomes both problems: it allows one to automatically find all contiguous sequences of single nucleotide polymorphisms in the genome that are jointly associated with the phenotype. It also solves both the inherent computational efficiency problem and the statistical problem of multiple hypothesis testing, which are both caused by the huge number of candidate intervals. We demonstrate on Arabidopsis thaliana genome-wide association study data that our approach can discover regions that exhibit genetic heterogeneity and would be missed by single-locus mapping. Conclusions: Our novel approach can contribute to the genome-wide discovery of intervals that are involved in the genetic heterogeneity underlying complex phenotypes. Availability and implementation: The code can be obtained at: http://www.bsse.ethz.ch/mlcb/research/bioinformatics-and-computational-biology/sis.html. Contact: felipe.llinares@bsse.ethz.ch Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26072488

Density-to-Potential Inversions to Guide Development of Exchange-Correlation Approximations at Finite Temperature

NASA Astrophysics Data System (ADS)

Jensen, Daniel; Wasserman, Adam; Baczewski, Andrew

The construction of approximations to the exchange-correlation potential for warm dense matter (WDM) is a topic of significant recent interest. In this work, we study the inverse problem of Kohn-Sham (KS) DFT as a means of guiding functional design at zero temperature and in WDM. Whereas the forward problem solves the KS equations to produce a density from a specified exchange-correlation potential, the inverse problem seeks to construct the exchange-correlation potential from specified densities. These two problems require different computational methods and convergence criteria despite sharing the same mathematical equations. We present two new inversion methods based on constrained variational and PDE-constrained optimization methods. We adapt these methods to finite temperature calculations to reveal the exchange-correlation potential's temperature dependence in WDM-relevant conditions. The different inversion methods presented are applied to both non-interacting and interacting model systems for comparison. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Security Administration under contract DE-AC04-94.

Evaluation of emission control strategies for airfield operations at the Los Angeles and San Francisco International Airports. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelinas, C.G.

1978-08-01

This report reviews potential air pollutant emission reductions which could be achieved by various strategies to control airfield operations at Los Angeles and San Francisco International Airports, and examines safety problems, cost impacts, potential fuel savings, time frame for strategy implementation, and potential regulatory and jurisdictional conflicts associated with each strategy. Airfield emission sources studied included aircraft operation in the idle, taxi, takeoff, and landing modes; ground service vehicles; fuel handling and storage; and aircraft engine maintenance. Nineteen potential strategies were identified, and seven strategies were selected for detailed analysis and examination after a preliminary evaluation. Two strategies, aircraft towingmore » and reducing the number of operating engines on the ground, appear to provide the most significant emission reduction. Both of these strategies offer potential reductions in the range of 20 to 40 percent of the carbon monoxide and nitrogen oxides which are currently emitted by ground operations. The aircraft towing strategy also offers a comparable improvement in suspended particulate matter emissions. When the overall feasibility of each strategy is evaluated, the strategy to reduce the number of operating engines appears to be the most viable since its implementation would result in fuel savings, no apparent safety problems, and it can be implemented immediately.« less

[Comparative life cycle environmental assessment between electric taxi and gasoline taxi in Beijing].

PubMed

Shi, Xiao-Qing; Sun, Zhao-Xin; Li, Xiao-Nuo; Li, Jin-Xiang; Yang, Jian-Xin

2015-03-01

Tailpipe emission of internal combustion engine vehicle (ICEV) is one of the main sources leading to atmospheric environmental problems such as haze. Substituting electric vehicles for conventional gasoline vehicles is an important solution for reducing urban air pollution. In 2011, as a pilot city of electric vehicle, Beijing launched a promotion plan of electric vehicle. In order to compare the environmental impacts between Midi electric vehicle (Midi EV) and Hyundai gasoline taxi (ICEV), this study created an inventory with local data and well-reasoned assumptions, and contributed a life cycle assessment (LCA) model with GaBi4.4 software and comparative life cycle environmental assessment by Life cycle impact analysis models of CML2001(Problem oriented) and EI99 (Damage oriented), which included the environmental impacts of full life cycle, manufacture phase, use phase and end of life. The sensitivity analysis of lifetime mileage and power structure was also provided. The results indicated that the full life cycle environmental impact of Midi EV was smaller than Hyundai ICEV, which was mainly due to the lower fossil fuel consumption. On the contrary, Midi EV exhibited the potential of increasing the environmental impacts of ecosystem quality influence and Human health influence. By CML2001 model, the results indicated that Midi EV might decrease the impact of Abiotic Depletion Potential, Global Warming Potential, Ozone Layer Depletion Potential and so on. However, in the production phase, the impact of Abiotic Depletion Potential, Acidification Potential, Eutrophication Potential, Global Warming Potential, Photochemical Ozone Creation Potential, Ozone Layer Depletion Potential, Marine Aquatic Ecotoxicity Potential, Terrestric Ecotoxicity Potential, Human Toxicity Potential of Midi EV were increased relative to Hyundai ICEV because of emissions impacts from its power system especially the battery production. Besides, in the use phase, electricity production was the main process leading to the impact of Abiotic Depletion Potential, Acidification Potential, Eutrophication Potential, Global Warming Potential, Photochemical Ozone Creation Potential, Marine Aquatic Ecotoxicity Potential, Freshwater Aquatic Ecotoxicity Potential, Human Toxicity Potential. While for Hyundai ICEV, gasoline production and tailpipe emission were the primary sources of environmental impact in the use phase. Tailpipe emission was a significant cause for increase in Eutrophication Potential and Global Warming Potential, and so forth. On the basis of inventory data analysis and 2010 Beijing electricity mix, the comparative results of haze-induced pollutants emissions showed that the full life cycle emissions of PM2.5, NO(x), SO(x), VOCs of Midi EV were higher than those of Hyundai ICEV, but the emission of NH3 was lower than that of Hyundai ICEV. Different emissions in use phase were the chief reason leading to this trend. In addition, by sensitivity analysis the results indicated that with the increase of lifetime mileage and proportion of cleaning energy, the rate of GHG( Green House Gas) emission reduction per kilometer of Midi EV became higher with respect to Hyundai ICEV. Haze-induced pollutants emission from EV could be significantly reduced using cleaner power energy. According to the assessment results, some management strategies aiming at electric car promotion were proposed.

Mental health consequences of international migration for Vietnamese Americans and the mediating effects of physical health and social networks: results from a natural experiment approach.

PubMed

Fu, Hongyun; VanLandingham, Mark J

2012-05-01

Although the existing literature on immigrant mental health is extensive, major substantive and methodological gaps remain. Substantively, there is little population-based research that focuses on the mental health consequences of migration for Vietnamese Americans. More generally, although a wide range of mental health problems among immigrants has been identified, the potential causal or mediating mechanisms underlying these problems remain elusive. This latter substantive shortcoming is related to a key methodological challenge involving the potentially confounding effects of selection on migration-related outcomes. This article addresses these challenges by employing a "natural experiment" design, involving comparisons among three population-based samples of Vietnamese immigrants, never-leavers, and returnees (N=709). Data were collected in Ho Chi Minh City and in New Orleans between 2003 and 2005. The study investigates the long-term impact of international migration on Vietnamese mental health, and the potential mediating effects of social networks and physical health on these migration-related outcomes. The results reveal both mental health advantages and disadvantages among Vietnamese immigrants relative to the two groups of Vietnamese nationals. Selection can be ruled out for some of these differences, and both social networks and physical health are found to play important explanatory roles.

Risk-based targeting: A new approach in environmental protection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, C.A.

1995-12-31

Risk-based targeting has recently emerged as an effective tool to help prioritize efforts to identify and manage geographic areas, chemicals, facilities, and agricultural activities that cause the most environmental degradation. This paper focuses on how the Environmental Protection Agency (EPA) has recently used risk-based targeting to identify and screen Federal, industrial, commercial and municipal facilities which contribute to probable human health (fish consumption advisories and contaminated fish tissue) and aquatic life (contaminated sediments) impacts. Preliminary results identified several hundred potential contributors of problem chemicals to probable impacts within the same river reach in 1991--93. Analysis by industry sector showed thatmore » the majority of the facilities identified were publicly owned treatment works (POTWs), in addition to industry organic and inorganic chemical manufacturers, petroleum refineries, and electric services, coatings, engravings, and allied services, among others. Both compliant and non-compliant potentially contributing facilities were identified to some extent in all EPA regions. Additional results identifying possible linkages of other pollutant sources to probable impacts, as well as estimation of potential exposure of these contaminants to minority and/or poverty populations are also presented. Out of these analyses, a number of short and long-term strategies are being developed that EPA may use to reduce loadings of problem contaminants to impacted waterbodies.« less

Diagrammatic representation of scalar QCD and sign problem at nonzero chemical potential

NASA Astrophysics Data System (ADS)

Bruckmann, Falk; Wellnhofer, Jacob

2018-01-01

We consider QCD at strong coupling with scalar quarks coupled to a chemical potential. Performing the link integrals we present a diagrammatic representation of the path integral weight. It is based on mesonic and baryonic building blocks, in close analogy to fermionic QCD. Likewise, the baryon loops are subject to a manifest conservation of the baryon number. The sign problem is expected to disappear in this representation and we do confirm this for three flavors, where a scalar baryon can be built and, thus, a dependence on the chemical potential occurs. For higher flavor number, we analyze examples for a potential sign problem in the baryon sector and conjecture that all weights are positive upon exploring the current conservation of each flavor.

Neural net classification of x-ray pistachio nut data

NASA Astrophysics Data System (ADS)

Casasent, David P.; Sipe, Michael A.; Schatzki, Thomas F.; Keagy, Pamela M.; Le, Lan Chau

1996-12-01

Classification results for agricultural products are presented using a new neural network. This neural network inherently produces higher-order decision surfaces. It achieves this with fewer hidden layer neurons than other classifiers require. This gives better generalization. It uses new techniques to select the number of hidden layer neurons and adaptive algorithms that avoid other such ad hoc parameter selection problems; it allows selection of the best classifier parameters without the need to analyze the test set results. The agriculture case study considered is the inspection and classification of pistachio nuts using x- ray imagery. Present inspection techniques cannot provide good rejection of worm damaged nuts without rejecting too many good nuts. X-ray imagery has the potential to provide 100% inspection of such agricultural products in real time. Only preliminary results are presented, but these indicate the potential to reduce major defects to 2% of the crop with 1% of good nuts rejected. Future image processing techniques that should provide better features to improve performance and allow inspection of a larger variety of nuts are noted. These techniques and variations of them have uses in a number of other agricultural product inspection problems.

On the relativistic field theory model of the deuteron II

NASA Astrophysics Data System (ADS)

Ivanov, A. N.; Troitskaya, N. I.; Faber, M.; Oberhummer, H.

1997-02-01

The relativistic field theory model of the deuteron suggested previously is revised and applied to the calculation of the cross sections of the low-energy radiative neutron-proton capture n + p -> D + γ and the low-energy two-proton fusion p + p -> D + e+ + νc. For the low-energy radiative neutron-proton capture n + p -> D + γ our result agrees well with both experimental data and the potential model prediction. In the case of the two-proton fusion the cross section obtained is 2.9 times as much as that given by the potential approach. The obtained result is discussed in connection with the solar neutrino problem.

Fluorescence spectroscopy for the detection of potentially malignant disorders of the oral cavity: analysis of 30 cases

NASA Astrophysics Data System (ADS)

Francisco, A. L. N.; Correr, W. R.; Azevedo, L. H.; Galletta, V. K.; Pinto, C. A. L.; Kowalski, L. P.; Kurachi, C.

2014-01-01

Oral cancer is a major health problem worldwide and although early diagnosis of potentially malignant and malignant diseases is associated with better treatment results, a large number of cancers are initially misdiagnosed, with unfortunate consequences for long-term survival. Fluorescence spectroscopy is a noninvasive modality of diagnostic approach using induced fluorescence emission in tumors that can improve diagnostic accuracy. The objective of this study was to determine the ability to discriminate between normal oral mucosa and potentially malignant disorders by fluorescence spectroscopy. Fluorescence investigation under 408 and 532 nm excitation wavelengths was performed on 60 subjects, 30 with potentially malignant disorders and 30 volunteers with normal mucosa. Data was analyzed to correlate fluorescence patterns with clinical and histopathological diagnostics. Fluorescence spectroscopy used as a point measurement technique resulted in a great variety of spectral information. In a qualitative analysis of the fluorescence spectral characteristics of each type of injury evaluated, it was possible to discriminate between normal and abnormal oral mucosa. The results show the potential use of fluorescence spectroscopy for an improved discrimination of oral disorders.

The effect of mining data k-means clustering toward students profile model drop out potential

NASA Astrophysics Data System (ADS)

Purba, Windania; Tamba, Saut; Saragih, Jepronel

2018-04-01

The high of student success and the low of student failure can reflect the quality of a college. One of the factors of fail students was drop out. To solve the problem, so mining data with K-means Clustering was applied. K-Means Clustering method would be implemented to clustering the drop out students potentially. Firstly the the result data would be clustering to get the information of all students condition. Based on the model taken was found that students who potentially drop out because of the unexciting students in learning, unsupported parents, diffident students and less of students behavior time. The result of process of K-Means Clustering could known that students who more potentially drop out were in Cluster 1 caused Credit Total System, Quality Total, and the lowest Grade Point Average (GPA) compared between cluster 2 and 3.

Numerical solution of the full potential equation using a chimera grid approach

NASA Technical Reports Server (NTRS)

Holst, Terry L.

1995-01-01

A numerical scheme utilizing a chimera zonal grid approach for solving the full potential equation in two spatial dimensions is described. Within each grid zone a fully-implicit approximate factorization scheme is used to advance the solution one interaction. This is followed by the explicit advance of all common zonal grid boundaries using a bilinear interpolation of the velocity potential. The presentation is highlighted with numerical results simulating the flow about a two-dimensional, nonlifting, circular cylinder. For this problem, the flow domain is divided into two parts: an inner portion covered by a polar grid and an outer portion covered by a Cartesian grid. Both incompressible and compressible (transonic) flow solutions are included. Comparisons made with an analytic solution as well as single grid results indicate that the chimera zonal grid approach is a viable technique for solving the full potential equation.

Parent training for young Norwegian children with ODD and CD problems: predictors and mediators of treatment outcome.

PubMed

Fossum, Sturla; Mørch, Willy-Tore; Handegård, Bjørn H; Drugli, May B; Larsson, Bo

2009-04-01

Participants were 121 children, aged 4-8 years referred for conduct problems, and their mothers. A parent training intervention was implemented in two outpatient clinics in Norway. Treatment responders were defined as children scoring below a cut-off on the Eyberg Child Behavior Inventory, a score below an optimal cut-off for children in day-care and school as reported by teachers, in addition to a 30% reduction or greater in observed negative parenting. Self-reported parenting practices were explored as potential mediators. The results of logistic regression analyses showed that high levels of maternal stress, clinical levels of ADHD, and being a girl predicted a poorer outcome in conduct problems at home, while pretreatment clinical levels of ADHD predicted a poorer outcome as perceived by the teachers. Harsh and inconsistent parental disciplining emerged as significant partial mediators of changes in conduct problems, highlighting the importance of altering parenting practices to modify young children's conduct problems.

Interpersonal violence as social construction: the potentially undermining role of claims making and advocacy statistics.

PubMed

Perrin, Robin D; Miller-Perrin, Cindy L

2011-10-01

The relationship between empirical research inquiry and advocacy efforts is complex and seldom addressed in the interpersonal violence literature. In this article, we first examine how social conditions come to be seen as social problems, using a social constructionist perspective. Next, we focus specifically on the problem of interpersonal violence as viewed through a social constructionist lens, highlighting the many ways in which advocacy has influenced public perceptions of interpersonal violence as a social problem. Finally, this article considers some of the consequences that may result from exaggerated or misleading claims, especially when they are made by social scientists who are presumably engaged in an objective discussion of a problem. These consequences include generating skepticism toward the social sciences, feeding a backlash movement, and diverting attention away from the most severe forms of interpersonal violence. Contrary to the goals of many advocates, some of these consequences may be detrimental to the very social problems they hope to alleviate.

On the v-representability of ensemble densities of electron systems

NASA Astrophysics Data System (ADS)

Gonis, A.; Däne, M.

2018-05-01

Analogously to the case at zero temperature, where the density of the ground state of an interacting many-particle system determines uniquely (within an arbitrary additive constant) the external potential acting on the system, the thermal average of the density over an ensemble defined by the Boltzmann distribution at the minimum of the thermodynamic potential, or the free energy, determines the external potential uniquely (and not just modulo a constant) acting on a system described by this thermodynamic potential or free energy. The paper describes a formal procedure that generates the domain of a constrained search over general ensembles (at zero or elevated temperatures) that lead to a given density, including as a special case a density thermally averaged at a given temperature, and in the case of a v-representable density determines the external potential leading to the ensemble density. As an immediate consequence of the general formalism, the concept of v-representability is extended beyond the hitherto discussed case of ground state densities to encompass excited states as well. Specific application to thermally averaged densities solves the v-representability problem in connection with the Mermin functional in a manner analogous to that in which this problem was recently settled with respect to the Hohenberg and Kohn functional. The main formalism is illustrated with numerical results for ensembles of one-dimensional, non-interacting systems of particles under a harmonic potential.

Mutual gravitational potential, force, and torque of a homogeneous polyhedron and an extended body: an application to binary asteroids

NASA Astrophysics Data System (ADS)

Shi, Yu; Wang, Yue; Xu, Shijie

2017-11-01

Binary systems are quite common within the populations of near-Earth asteroids, main-belt asteroids, and Kuiper belt asteroids. The dynamics of binary systems, which can be modeled as the full two-body problem, is a fundamental problem for their evolution and the design of relevant space missions. This paper proposes a new shape-based model for the mutual gravitational potential of binary asteroids, differing from prior approaches such as inertia integrals, spherical harmonics, or symmetric trace-free tensors. One asteroid is modeled as a homogeneous polyhedron, while the other is modeled as an extended rigid body with arbitrary mass distribution. Since the potential of the polyhedron is precisely described in a closed form, the mutual gravitational potential can be formulated as a volume integral over the extended body. By using Taylor expansion, the mutual potential is then derived in terms of inertia integrals of the extended body, derivatives of the polyhedron's potential, and the relative location and orientation between the two bodies. The gravitational forces and torques acting on the two bodies described in the body-fixed frame of the polyhedron are derived in the form of a second-order expansion. The gravitational model is then used to simulate the evolution of the binary asteroid (66391) 1999 KW4, and compared with previous results in the literature.

On the v-representability of ensemble densities of electron systems

DOE PAGES

Gonis, A.; Dane, M.

2017-12-30

Analogously to the case at zero temperature, where the density of the ground state of an interacting many-particle system determines uniquely (within an arbitrary additive constant) the external potential acting on the system, the thermal average of the density over an ensemble defined by the Boltzmann distribution at the minimum of the thermodynamic potential, or the free energy, determines the external potential uniquely (and not just modulo a constant) acting on a system described by this thermodynamic potential or free energy. The study describes a formal procedure that generates the domain of a constrained search over general ensembles (at zeromore » or elevated temperatures) that lead to a given density, including as a special case a density thermally averaged at a given temperature, and in the case of a v-representable density determines the external potential leading to the ensemble density. As an immediate consequence of the general formalism, the concept of v-representability is extended beyond the hitherto discussed case of ground state densities to encompass excited states as well. Specific application to thermally averaged densities solves the v-representability problem in connection with the Mermin functional in a manner analogous to that in which this problem was recently settled with respect to the Hohenberg and Kohn functional. Finally, the main formalism is illustrated with numerical results for ensembles of one-dimensional, non-interacting systems of particles under a harmonic potential.« less

The potential application of the blackboard model of problem solving to multidisciplinary design

NASA Technical Reports Server (NTRS)

Rogers, James L.

1989-01-01

The potential application of the blackboard model of problem solving to multidisciplinary design is discussed. Multidisciplinary design problems are complex, poorly structured, and lack a predetermined decision path from the initial starting point to the final solution. The final solution is achieved using data from different engineering disciplines. Ideally, for the final solution to be the optimum solution, there must be a significant amount of communication among the different disciplines plus intradisciplinary and interdisciplinary optimization. In reality, this is not what happens in today's sequential approach to multidisciplinary design. Therefore it is highly unlikely that the final solution is the true optimum solution from an interdisciplinary optimization standpoint. A multilevel decomposition approach is suggested as a technique to overcome the problems associated with the sequential approach, but no tool currently exists with which to fully implement this technique. A system based on the blackboard model of problem solving appears to be an ideal tool for implementing this technique because it offers an incremental problem solving approach that requires no a priori determined reasoning path. Thus it has the potential of finding a more optimum solution for the multidisciplinary design problems found in today's aerospace industries.

Force-field functor theory: classical force-fields which reproduce equilibrium quantum distributions

PubMed Central

Babbush, Ryan; Parkhill, John; Aspuru-Guzik, Alán

2013-01-01

Feynman and Hibbs were the first to variationally determine an effective potential whose associated classical canonical ensemble approximates the exact quantum partition function. We examine the existence of a map between the local potential and an effective classical potential which matches the exact quantum equilibrium density and partition function. The usefulness of such a mapping rests in its ability to readily improve Born-Oppenheimer potentials for use with classical sampling. We show that such a map is unique and must exist. To explore the feasibility of using this result to improve classical molecular mechanics, we numerically produce a map from a library of randomly generated one-dimensional potential/effective potential pairs then evaluate its performance on independent test problems. We also apply the map to simulate liquid para-hydrogen, finding that the resulting radial pair distribution functions agree well with path integral Monte Carlo simulations. The surprising accessibility and transferability of the technique suggest a quantitative route to adapting Born-Oppenheimer potentials, with a motivation similar in spirit to the powerful ideas and approximations of density functional theory. PMID:24790954

Effect of refining variables on the properties and composition of JP-5

NASA Technical Reports Server (NTRS)

Lieberman, M.; Taylor, W. F.

1980-01-01

Potential future problem areas that could arise from changes in the composition, properties, and potential availability of JP-5 produced in the near future are identified. Potential fuel problems concerning thermal stability, lubricity, low temperature flow, combustion, and the effect of the use of specific additives on fuel properties and performance are discussed. An assessment of available crudes and refinery capabilities is given.

Heading off boundary problems: clinical supervision as risk management.

PubMed

Walker, R; Clark, J J

1999-11-01

The effective management of risk in clinical practice includes steps to limit harm to clients resulting from ethical violations or professional misconduct. Boundary problems constitute some of the most damaging ethical violations. The authors propose an active use of clinical supervision to anticipate and head off possible ethical violations by intervening when signs of boundary problems appear. The authors encourage a facilitative, Socratic method, rather than directive approaches, to help supervisees maximize their learning about ethical complexities. Building on the idea of a slippery slope, in which seemingly insignificant acts can lead to unethical patterns of behavior, the authors discuss ten cues to potential boundary problems, including strong feelings about a client; extended sessions with clients; gift giving between clinician and client; loans, barter, and sale of goods; clinician self-disclosures; and touching and sex. The authors outline supervisory interventions to be made when the cues are detected.

Parental corporal punishment predicts behavior problems in early childhood.

PubMed

Mulvaney, Matthew K; Mebert, Carolyn J

2007-09-01

Using data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (Research Triangle Institute, 2002), this study examined the impact of corporal punishment (CP) on children's behavior problems. Longitudinal analyses were specified that controlled for covarying contextual and parenting variables and that partialed child effects. The results indicate that parental CP uniquely contributes to negative behavioral adjustment in children at both 36 months and at 1st grade, with the effects at the earlier age more pronounced in children with difficult temperaments. Parents and mental health professionals who work to modify children's negative behavior should be aware of the unique impact that CP likely plays in triggering and maintaining children's behavior problems. Broad-based family policies that reduce the use of this parenting behavior would potentially increase children's mental health and decrease the incidence of children's behavior problems. PsycINFO Database Record (c) 2007 APA, all rights reserved

Interparental Conflict, Community Violence, and Child Problems: Making Sense of Counterintuitive Findings

PubMed Central

Rosenfield, David; Jouriles, Ernest N.; McDonald, Renee; Mueller, Victoria

2014-01-01

Objective This research examines children's exposure to community violence as a potential moderator of the link between destructive interparental conflict (IPC) and child adjustment problems. In addition, this research extends the literature by evaluating children's threat appraisals of IPC as a process that might help explain moderator effects. Method Participants were 539 mothers and their 7-10 year old children. Children reported on their exposure to community violence and IPC, their threat appraisals of IPC, and their adjustment outcomes. Mothers reported on children's adjustment outcomes as well. Results Exposure to community violence mitigated the association between IPC and children's self-reported internalizing problems. Children's threat appraisals helped explain this effect. Discussion Exposure to high levels of community violence may weaken the extent to which children feel threatened by IPC, which may attenuate the relation between children's exposure to IPC and their self-reported internalizing problems. PMID:24827022

The link between drinking and gambling among undergraduate university students.

PubMed

Hodgins, David C; Racicot, Stephanie

2013-09-01

The purpose of this research was to explore different aspects of the link between alcohol use and gambling among undergraduate university students (N = 121). Potential aspects of the link examined included level of involvement in each behavior, consequences, motives for involvement, and impaired control over involvement. Results confirmed that drinking and gambling among university students are associated, consistent with the expectations of a problem syndrome model. The strongest link was between general dimensions of problematic involvement for both behaviors. Students who drink to cope and have other indicators of alcohol problems are more likely to gamble to cope, gamble to win money, and have higher gambling involvement and gambling-related problems. However, the salience of drinking and gambling to cope in this relationship is an interesting finding that needs further exploration and extension to other problem behaviors. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Paternal Antisocial Behavior (But Not Paternal ADHD) Is Associated With Negative Parenting and Child Conduct Problems.

PubMed

LeMoine, Kaitlyn A; Romirowsky, Abigail M; Woods, Kelsey E; Chronis-Tuscano, Andrea

2015-09-23

Parental psychopathology and parenting quality robustly predict negative outcomes among children with ADHD. Little research has investigated associations between paternal ADHD symptoms and parenting, though there is clear evidence linking maternal ADHD symptoms with both suboptimal parenting and child conduct problems, and considerable research supporting fathers' significant contributions to their children's development. This cross-sectional study examined psychopathology and parenting in a sample of fathers (N = 102) and their 5- to 12-year-old children with previously diagnosed ADHD. Results suggested that paternal antisocial personality disorder (ASPD) symptoms (rather than ADHD symptoms) were robustly associated with child conduct problems, with an indirect effect through paternal negative parenting. This study suggests that negative parenting may be a potential mechanism by which paternal ASPD is associated with child conduct problems, and demonstrates the importance of considering co-occurring psychopathology in research examining adult ADHD, parenting, and child outcomes. © The Author(s) 2015.

Optimization-based additive decomposition of weakly coercive problems with applications

DOE PAGES

Bochev, Pavel B.; Ridzal, Denis

2016-01-27

In this study, we present an abstract mathematical framework for an optimization-based additive decomposition of a large class of variational problems into a collection of concurrent subproblems. The framework replaces a given monolithic problem by an equivalent constrained optimization formulation in which the subproblems define the optimization constraints and the objective is to minimize the mismatch between their solutions. The significance of this reformulation stems from the fact that one can solve the resulting optimality system by an iterative process involving only solutions of the subproblems. Consequently, assuming that stable numerical methods and efficient solvers are available for every subproblem,more » our reformulation leads to robust and efficient numerical algorithms for a given monolithic problem by breaking it into subproblems that can be handled more easily. An application of the framework to the Oseen equations illustrates its potential.« less

Predictive factors of excessive online poker playing.

PubMed

Hopley, Anthony A B; Nicki, Richard M

2010-08-01

Despite the widespread rise of online poker playing, there is a paucity of research examining potential predictors for excessive poker playing. The aim of this study was to build on recent research examining motives for Texas Hold'em play in students by determining whether predictors of other kinds of excessive gambling apply to Texas Hold'em. Impulsivity, negative mood states, dissociation, and boredom proneness have been linked to general problem gambling and may play a role in online poker. Participants of this study were self-selected online poker players (N = 179) who completed an online survey. Results revealed that participants played an average of 20 hours of online poker a week and approximately 9% of the sample was classified as a problem gambler according to the Canadian Problem Gambling Index. Problem gambling, in this sample, was uniquely predicted by time played, dissociation, boredom proneness, impulsivity, and negative affective states, namely depression, anxiety, and stress.

Social Networking Sites: An Adjunctive Treatment Modality for Psychological Problems

PubMed Central

Menon, Indu S.; Sharma, Manoj Kumar; Chandra, Prabha S.; Thennarasu, K.

2014-01-01

Background: Social networking is seen as a way to enhance social support and feeling of well-being. The present work explores the potentials of social networking sites as an adjunctive treatment modality for initiating treatment contact as well as for managing psychological problems. Materials and Methods: Interview schedule, Facebook intensity questionnaire were administered on 28 subjects with a combination of 18 males and 10 females. They were taken from the in-patient and out-patient psychiatry setting of the hospital. Results: Facebook was the most popular sites and used to seek emotional support on the basis of the frequent updates of emotional content that users put in their profile; reconciliations, escape from the problems or to manage the loneliness; getting information about illness and its treatment and interaction with experts and also manifested as problematic use. Conclusions: It has implications for developing social networking based adjunctive treatment modality for psychological problems. PMID:25035548

Leading Causes of Death in Nonmetropolitan and Metropolitan Areas— United States, 1999–2014

PubMed Central

Garcia, Macarena C.; Bastian, Brigham; Rossen, Lauren M.; Ingram, Deborah D.; Faul, Mark; Massetti, Greta M.; Thomas, Cheryll C.; Hong, Yuling; Yoon, Paula W.; Iademarco, Michael F.

2017-01-01

Problem/Condition Higher rates of death in nonmetropolitan areas (often referred to as rural areas) compared with metropolitan areas have been described but not systematically assessed. Period Covered 1999–2014 Description of System Mortality data for U.S. residents from the National Vital Statistics System were used to calculate age-adjusted death rates and potentially excess deaths for nonmetropolitan and metropolitan areas for the five leading causes of death. Age-adjusted death rates included all ages and were adjusted to the 2000 U.S. standard population by the direct method. Potentially excess deaths are defined as deaths among persons aged <80 years that exceed the numbers that would be expected if the death rates of states with the lowest rates (i.e., benchmark states) occurred across all states. (Benchmark states were the three states with the lowest rates for each cause during 2008–2010.) Potentially excess deaths were calculated separately for nonmetropolitan and metropolitan areas. Data are presented for the United States and the 10 U.S. Department of Health and Human Services public health regions. Results Across the United States, nonmetropolitan areas experienced higher age-adjusted death rates than metropolitan areas. The percentages of potentially excess deaths among persons aged <80 years from the five leading causes were higher in nonmetropolitan areas than in metropolitan areas. For example, approximately half of deaths from unintentional injury and chronic lower respiratory disease in nonmetropolitan areas were potentially excess deaths, compared with 39.2% and 30.9%, respectively, in metropolitan areas. Potentially excess deaths also differed among and within public health regions; within regions, nonmetropolitan areas tended to have higher percentages of potentially excess deaths than metropolitan areas. Interpretation Compared with metropolitan areas, nonmetropolitan areas have higher age-adjusted death rates and greater percentages of potentially excess deaths from the five leading causes of death, nationally and across public health regions. Public Health Action Routine tracking of potentially excess deaths in nonmetropolitan areas might help public health departments identify emerging health problems, monitor known problems, and focus interventions to reduce preventable deaths in these areas. PMID:28081058

Time Perspectives and Gambling in Adolescent Boys: Differential Effects of Present- and Future-Orientation.

PubMed

Donati, Maria Anna; Sottili, Elena; Morsanyi, Kinga; Primi, Caterina

2018-06-04

Adolescent boys are characterised by increased risk-taking behavior, including a relatively high propensity to develop problem gambling habits. The association between gambling and sensitivity to immediately available rewards is well-established, suggesting that gamblers are less influenced by potential future consequences than non-gamblers. Nevertheless, existing studies have considered present- and future-orientation as two ends of the same continuum, and have not investigated the possibility that present and future perspectives might make independent contributions to gambling behavior. In the current study, we adopted Zimbardo's multidimensional approach, which discriminates between not only present and future perspectives, but also between a hedonistic and fatalistic present-orientation (in addition to positive and negative orientations towards the past). The participants were 223 male adolescents (mean age = 16.7 years). We investigated the effects of time perspectives on gambling frequency and gambling problem severity, after taking into account the effects of age, sensation seeking, and gambling-related cognitive distortions. Gambling frequency was significantly predicted by the present fatalistic perspective, and problem gambling was significantly (negatively) related to the future perspective. The present hedonistic and past negative perspectives were also significantly related to both gambling frequency and gambling problems, although they did not explain additional variance in gambling behavior when the effects of the other factors were controlled. Overall, these results offer a fresh perspective on the role of time perspectives in gambling behavior, with potential implications for understanding the origins of gambling problems and the development of novel interventions.

Risk and protective factors for psychological distress among adolescents: a family study in the Nord-Trøndelag Health Study.

PubMed

Myklestad, Ingri; Røysamb, Espen; Tambs, Kristian

2012-05-01

The study aimed to investigate potential adolescent and parental psychosocial risk and protective factors for psychological distress among adolescents and, in addition, to examine potential gender and age differences in the effects of risk factors on adolescent psychological distress. Data were collected among 8,984 Norwegian adolescents (13-19 years) and their parents in the Nord-Trøndelag Health Study (HUNT). The outcome measure was psychological distress (SCL-5). Bivariate regression analysis with generalized estimating equation (GEE) model showed that all parental self-reported variables (mental distress, substance use, social network, economic problems, unemployment and family structure) and adolescents' self-reported variables (leisure activities, social support from friends, school-related problems and substance use) were significantly associated with psychological distress among adolescents. Results revealed that in a multiple regression analysis with a GEE model, adolescent psychosocial variables, specifically academic-related problems and being bullied at school, emerged as the strongest predictors of psychological distress among adolescents after controlling for age, gender, and all parental and adolescent variables. The following psychosocial risk factors were significantly more important for girl's psychological distress compared to boys: problems with academic achievement, conduct problems in school, frequency of being drunk, smoking, dissatisfaction in school, living alone and seen parents being drunk. Academic achievement and being bullied at school were the psychosocial factors most strongly associated with psychological distress among adolescents. Parental factors had an indirect effect on adolescent psychological distress, through adolescents' psychosocial factors.

Patient safety is not enough: targeting quality improvements to optimize the health of the population.

PubMed

Woolf, Steven H

2004-01-06

Ensuring patient safety is essential for better health care, but preoccupation with niches of medicine, such as patient safety, can inadvertently compromise outcomes if it distracts from other problems that pose a greater threat to health. The greatest benefit for the population comes from a comprehensive view of population needs and making improvements in proportion with their potential effect on public health; anything less subjects an excess of people to morbidity and death. Patient safety, in context, is a subset of health problems affecting Americans. Safety is a subcategory of medical errors, which also includes mistakes in health promotion and chronic disease management that cost lives but do not affect "safety." These errors are a subset of lapses in quality, which result not only from errors but also from systemic problems, such as lack of access, inequity, and flawed system designs. Lapses in quality are a subset of deficient caring, which encompasses gaps in therapeutics, respect, and compassion that are undetected by normative quality indicators. These larger problems arguably cost hundreds of thousands more lives than do lapses in safety, and the system redesigns to correct them should receive proportionately greater emphasis. Ensuring such rational prioritization requires policy and medical leaders to eschew parochialism and take a global perspective in gauging health problems. The public's well-being requires policymakers to view the system as a whole and consider the potential effect on overall population health when prioritizing care improvements and system redesigns.

Problems as Opportunity: Meeting Growth Needs

ERIC Educational Resources Information Center

Brokenleg, Martin; Long, Nicholas J.

2013-01-01

Children have innate brain programs for building personal strengths and social bonds, but conflict and trauma can jeopardize their growth potentials. Life Space Crisis Intervention (LSCI) provides specific tools to turn problems into potentials. Life Space Crisis Intervention provides advanced therapeutic strategies for building strengths in…

The Social Psychology of Potential Problems in Family Vacation Travel

ERIC Educational Resources Information Center

Rosenblatt, Paul C.; Russell, Martha G.

1975-01-01

Social psychological thinking and the data of an exploratory study are used to illuminate potential problems in family vacation travel. Vacation travel is seen as providing both the opportunity for revitalization and creative change and the opportunity for serious interpersonal difficulties. (Author)

PROBLEMS OF THE OPTICAL MODEL FOR DEUTERONS. I. PARAMETERS OF THE OPTICAL POTENTIAL (in Polish)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grotowski, K.

1963-01-01

S>Problems concerning the optical model are discussed. Some special properties of deuterons as projectiles influence the optical model describing their interaction with nuclei. Several experiments were performed to obtain parameters of the optical model potential. (auth)

Determination of the expansion of the potential of the earth's normal gravitational field

NASA Astrophysics Data System (ADS)

Kochiev, A. A.

The potential of the generalized problem of 2N fixed centers is expanded in a polynomial and Legendre function series. Formulas are derived for the expansion coefficients, and the disturbing function of the problem is constructed in an explicit form.

Why is working memory capacity related to matrix reasoning tasks?

PubMed

Harrison, Tyler L; Shipstead, Zach; Engle, Randall W

2015-04-01

One of the reasons why working memory capacity is so widely researched is its substantial relationship with fluid intelligence. Although this relationship has been found in numerous studies, researchers have been unable to provide a conclusive answer as to why the two constructs are related. In a recent study, researchers examined which attributes of Raven's Progressive Matrices were most strongly linked with working memory capacity (Wiley, Jarosz, Cushen, & Colflesh, Journal of Experimental Psychology: Learning, Memory, and Cognition, 37, 256-263, 2011). In that study, Raven's problems that required a novel combination of rules to solve were more strongly correlated with working memory capacity than were problems that did not. In the present study, we wanted to conceptually replicate the Wiley et al. results while controlling for a few potential confounds. Thus, we experimentally manipulated whether a problem required a novel combination of rules and found that repeated-rule-combination problems were more strongly related to working memory capacity than were novel-rule-combination problems. The relationship to other measures of fluid intelligence did not change based on whether the problem required a novel rule combination.

The public's view of the competence, dangerousness, and need for legal coercion of persons with mental health problems.

PubMed Central

Pescosolido, B A; Monahan, J; Link, B G; Stueve, A; Kikuzawa, S

1999-01-01

OBJECTIVES: The authors examined Americans' opinions about financial and treatment competence of people with mental health problems, potential for harm to self or others, and the use of legal means to force treatment. METHODS: The 1996 General Social Survey provided interview data with a nationally representative sample (n = 1444). Respondents were given a vignette based on diagnostic criteria for schizophrenia, major depression, alcohol dependence, or drug dependence, or a "control" case. RESULTS: The specific nature of the problem was the most important factor shaping public reaction. Respondents viewed those with "troubles," alcohol dependence, or depression as able to make treatment decisions. Most reported that persons with alcohol or drug problems or schizophrenia cannot manage money and are likely to be violent toward others. Respondents indicated a willingness to coerce individuals into treatment. Respondent and other case characteristics rarely affected opinions. CONCLUSIONS: Americans report greater concern with individuals who have drug or alcohol problems than with persons who have other mental health problems. Evaluations of dangerousness and coercion indicate a continuing need for public education. PMID:10474550

Agrichemical safety practices on farms in the western Cape.

PubMed

London, L

1994-05-01

In order to study agrichemical safety practices in a rural farming area in the western Cape, an audit of 45 randomly sampled farms was performed over 3 months in 1992. A response rate of 87% was achieved, and the survey results suggest that approximately 9% of permanent and 14% of seasonal farm workers are employed in jobs with potential exposure to agrichemicals. While protective equipment was widely available, gloves and masks were seldom used, with little enforcement or commercial support from the suppliers of the equipment. Farm workers receive little training on pesticide safety, but interest in the possibility of further training for workers was high. In the absence of a system of pesticide disposal, the presence of residual, unwanted and outdated stocks of pesticides in farmers' stores, and to a lesser extent the presence of empty containers, are identified as important problems. Current pesticide storage practices require improvement by simple industrial hygiene measures. Health facilities available to workers on most farms are extremely limited, particularly in the light of statutory requirements for occupational safety and health under the Machinery and Occupational Safety Act. It is argued that collective solutions to problems of pesticide safety are possible within the ambit of a public health response, particularly given the willingness of the farming community to identify and address potential health problems. As a result, initiatives to meet these needs are currently under way in the region.

Reliability and Validity of Three Instruments (DSM-IV, CPGI, and PPGM) in the Assessment of Problem Gambling in South Korea.

PubMed

Back, Ki-Joon; Williams, Robert J; Lee, Choong-Ki

2015-09-01

Most research on the assessment, epidemiology, and treatment of problem gambling has occurred in Western jurisdictions. This potentially limits the cross-cultural validity of problem gambling assessment instruments as well as etiological models of problem gambling. The primary objective of the present research was to investigate the reliability and validity of three problem gambling assessment instruments within a South Korean context. A total of 4,330 South Korean adults participated in a comprehensive assessment of their gambling behavior that included the administration of the DSM-IV criteria for pathological gambling (NODS), the Canadian Problem Gambling Index (CPGI), and the Problem and Pathological Gambling Measure (PPGM). Cronbach alpha showed that all three instruments had good internal consistency. Concurrent validity was established by the significant associations observed between scores on the instruments and measures of gambling involvement (number of gambling formats engaged in; frequency of gambling; and gambling expenditure). Most importantly, kappa statistics showed that all instruments have satisfactory classification accuracy against clinical assessment of problem gambling conducted by South Korean clinicians (NODS κ = .66; PPGM κ = .62; CPGI κ = .51). These results confirm that Western-derived operationalizations of problem gambling have applicability in a South Korean setting.

Enhancing School Asthma Action Plans: Qualitative Results from Southeast Minnesota Beacon Stakeholder Groups

ERIC Educational Resources Information Center

Egginton, Jason S.; Textor, Lauren; Knoebel, Erin; McWilliams, Deborah; Aleman, Marty; Yawn, Barbara

2013-01-01

Background: This study explores ways southeast Minnesota schools currently address asthma problems, identifies areas for improvement, and assesses the potential value of asthma action plans (AAPs) in schools. Methods: Focus groups were used to query stakeholder groups on asthma care in schools. Groups were held separately for elementary school…

Using Anchoring Vignettes to Assess Group Differences in General Self-Rated Health

ERIC Educational Resources Information Center

Grol-Prokopczyk, Hanna; Freese, Jeremy; Hauser, Robert M.

2011-01-01

This article addresses a potentially serious problem with the widely used self-rated health (SRH) survey item: that different groups have systematically different ways of using the item's response categories. Analyses based on unadjusted SRH may thus yield misleading results. The authors evaluate anchoring vignettes as a possible solution to this…

Using Propensity Scores in Quasi-Experimental Designs to Equate Groups

ERIC Educational Resources Information Center

Lane, Forrest C.; Henson, Robin K.

2010-01-01

Education research rarely lends itself to large scale experimental research and true randomization, leaving the researcher to quasi-experimental designs. The problem with quasi-experimental research is that underlying factors may impact group selection and lead to potentially biased results. One way to minimize the impact of non-randomization is…

Quantitative assessment of landslide risk in design practice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romanov, A.M.; Darevskii, V.E.

1995-03-01

Developments of the State Institute for River Transport Protection, which are directed toward practical implementation of an engineering method recommended by regulatory documents for calculation of landslide phenomena, are cited; the potential of operating computer software is demonstrated. Results of calculations are compared with test data, and also with problems solved in the new developments.

Classroom Interaction: Potential or Problem? The Case of Karagwe

ERIC Educational Resources Information Center

Wedin, Asa

2010-01-01

This paper discusses interactional patterns in classrooms in primary school in rural Tanzania, based on an ethnographic study on literacy practices. The paper argues that the official policy of Swahili-only in primary school, together with the huge gap between high expectations on educational outcome and lack of resources, have resulted in the…

Genes and Memory: The Neuroanatomical Correlates of Emotional Memory in Monozygotic Twin Discordant for Schizophrenia

ERIC Educational Resources Information Center

Fahim, Cherine; Stip, Emmanuel; Mancini-Marie, Adham; Beauregard, Mario

2004-01-01

Background: Brain morphology and physiological measures in schizophrenia have yielded inconsistent results. This may be due in part to difficulties in ascertaining precisely to what degree each measure deviates from its genetically and environmentally determined potential level. We attempted to surmount this problem in a paradigm involving…

Testing the School-to-Prison Pipeline

ERIC Educational Resources Information Center

Owens, Emily G.

2017-01-01

The School-to-Prison Pipeline is a social phenomenon where students become formally involved with the criminal justice system as a result of school policies that use law enforcement, rather than discipline, to address behavioral problems. A potentially important part of the School-to-Prison Pipeline is the use of sworn School Resource Officers…

Texas Youth Fitness Study: A Commentary

ERIC Educational Resources Information Center

Corbin, Charles B.

2010-01-01

When institutional testing is done well, there are many potential benefits; however, it is not without its negatives. The Texas Youth Evaluation Project (TYEP) is an example of large scale institutional testing that yielded more than a few benefits. However, results reported some problems as well. Much has been learned from the TYEP, including…

Recall of Childhood Neglect and Physical Abuse as Differential Predictors of Current Psychological Functioning.

ERIC Educational Resources Information Center

Gauthier, Lisa; And Others

1996-01-01

Histories of child neglect or child physical abuse were correlated with psychological functioning in 236 male and 276 female undergraduates. Childhood neglect was more predictive of psychological problems and anxious attachment styles than was physical abuse. Results suggest neglect and physical abuse are potentially separate moderators of…

Important Factors Underlying Ethical Intentions of Students: Implications for Marketing Education

ERIC Educational Resources Information Center

Singhapakdi, Anusorn

2004-01-01

This study analyzes the relative influences of perceived ethical problems, perceived importance of ethics, idealism, relativism, and gender on ethical intention of students. The potential impacts of grade point average and education level of students were also investigated. The results from a survey of students in marketing classes from two major…

Recruitment to Physics and Mathematics Teaching: A Personality Problem?

ERIC Educational Resources Information Center

Smithers, Alan; Hill, Susan

1989-01-01

Results of a British study indicate that, among potential applicants (N=177), a small demand exists for a proposed science education degree program. Findings suggest that recruitment of science and math teachers may be hampered because the satisfactions provided by teaching are unlike those sought by science and math specialists. (IAH)

Identifying, Recruiting, Developing, and Retaining Quality Adjunct Faculty in Rural Community Colleges in Ohio

ERIC Educational Resources Information Center

Wise, Jessica L.

2013-01-01

The purpose of this research was to determine how to identify, recruit, develop, and retain suitable adjunct faculty in rural community colleges in Ohio. The research problem resulted from a limited availability of potential faculty possessing the required credentials and andragogical training in Ohio's rural and Appalachian areas. Research…

49 CFR Appendix D to Part 218 - Requirements and Considerations for Implementing Technology Aided Point Protection

Code of Federal Regulations, 2011 CFR

2011-10-01

... for a remote control crew; however, several potential problems may result when non-crewmembers are... cameras or other technological means, provided that it and the procedures for use provide an equivalent... protection as well as specific additional requirements for those operations involving remote control...

49 CFR Appendix D to Part 218 - Requirements and Considerations for Implementing Technology Aided Point Protection

Code of Federal Regulations, 2012 CFR

2012-10-01

... for a remote control crew; however, several potential problems may result when non-crewmembers are... cameras or other technological means, provided that it and the procedures for use provide an equivalent... protection as well as specific additional requirements for those operations involving remote control...

49 CFR Appendix D to Part 218 - Requirements and Considerations for Implementing Technology Aided Point Protection

Code of Federal Regulations, 2014 CFR

2014-10-01

... for a remote control crew; however, several potential problems may result when non-crewmembers are... cameras or other technological means, provided that it and the procedures for use provide an equivalent... protection as well as specific additional requirements for those operations involving remote control...

49 CFR Appendix D to Part 218 - Requirements and Considerations for Implementing Technology Aided Point Protection

Code of Federal Regulations, 2013 CFR

2013-10-01

... for a remote control crew; however, several potential problems may result when non-crewmembers are... cameras or other technological means, provided that it and the procedures for use provide an equivalent... protection as well as specific additional requirements for those operations involving remote control...

49 CFR Appendix D to Part 218 - Requirements and Considerations for Implementing Technology Aided Point Protection

Code of Federal Regulations, 2010 CFR

2010-10-01

... for a remote control crew; however, several potential problems may result when non-crewmembers are... cameras or other technological means, provided that it and the procedures for use provide an equivalent... protection as well as specific additional requirements for those operations involving remote control...

Converting Municipal Waste into Automobile Fuel: Ethanol from Newspaper

ERIC Educational Resources Information Center

Mascal, Mark; Scown, Richard

2008-01-01

Waste newspaper is pulped with acid and its cellulose is hydrolyzed. The resulting glucose syrup is fermented with yeast and distilled to give ethanol. The experiment highlights the potential of applied chemistry to confront problems of economic importance, that is, the effective utilization of biomass to reduce dependence on non-renewable…

American college of gastroenterology monograph on the management of irritable bowel syndrome.

PubMed

Camilleri, Michael

2015-04-01

This editorial reviews a recently published guideline on management of irritable bowel syndrome. The guideline illustrates problems arising from the quality of clinical trials used in systematic reviews and the potential impact of the inherent weaknesses of those trials on rating the strength of evidence and the resulting recommendations.

Web-Based Family Life Education: Spotlight on User Experience

ERIC Educational Resources Information Center

Doty, Jennifer; Doty, Matthew; Dwrokin, Jodi

2011-01-01

Family Life Education (FLE) websites can benefit from the field of user experience, which makes technology easy to use. A heuristic evaluation of five FLE sites was performed using Neilson's heuristics, guidelines for making sites user friendly. Greater site complexity resulted in more potential user problems. Sites most frequently had problems…

Aldehyde emissions from particleboard and medium density fiberboard products

Treesearch

Melissa G. D. Baumann; Linda F. Lorenz; Stuart A. Batterman; Guo-Zheng Zhang

2000-01-01

Indoor air quality problems resulting from the emission of volatile organic compounds (VOCs) have become an issue of increasing concern. Emissions from building and furnishing materials, which are frequently constructed from particleboard and medium density fiberboard (MDF), are a potentially important contributor of indoor VOCs. In this research, VOC emissions from...

Landscape change in the southern Piedmont: challenges, solutions, and uncertainty across scales

USGS Publications Warehouse

Conroy, M.J.; Allen, Craig R.; Peterson, J.T.; Pritchard, L.J.; Moore, C.T.

2003-01-01

The southern Piedmont of the southeastern United States epitomizes the complex and seemingly intractable problems and hard decisions that result from uncontrolled urban and suburban sprawl. Here we consider three recurrent themes in complicated problems involving complex systems: (1) scale dependencies and cross-scale, often nonlinear relationships; (2) resilience, in particular the potential for complex systems to move to alternate stable states with decreased ecological and/or economic value; and (3) uncertainty in the ability to understand and predict outcomes, perhaps particularly those that occur as a result of human impacts. We consider these issues in the context of landscape-level decision making, using as an example water resources and lotic systems in the Piedmont region of the southeastern United States.

Heat Conduction in Ceramic Coatings: Relationship Between Microstructure and Effective Thermal Conductivity

NASA Technical Reports Server (NTRS)

Kachanov, Mark

1998-01-01

Analysis of the effective thermal conductivity of ceramic coatings and its relation to the microstructure continued. Results (obtained in Task 1) for the three-dimensional problem of heat conduction in a solid containing an inclusion (or, in particular, cavity - thermal insulator) of the ellipsoidal shape, were further advanced in the following two directions: (1) closed form expressions of H tensor have been derived for special cases of ellipsoidal cavity geometry: spheroid, crack-like spheroidal cavity and needle shaped spheroidal cavity; (2) these results for one cavity have been incorporated to construct heat energy potential for a solid with many spheroidal cavities (in the approximation of non-interacting defects). This problem constitutes a basic building block for further analyses.

Status of research into lightning effects on aircraft

NASA Technical Reports Server (NTRS)

Plumer, J. A.

1976-01-01

Developments in aircraft lightning protection since 1938 are reviewed. Potential lightning problems resulting from present trends toward the use of electronic controls and composite structures are discussed, along with presently available lightning test procedures for problem assessment. The validity of some procedures is being questioned because of pessimistic results and design implications. An in-flight measurement program is needed to provide statistics on lightning severity at flight altitudes and to enable more realistic tests, and operators are urged to supply researchers with more details on electronic components damaged by lightning strikes. A need for review of certain aspects of fuel system vulnerability is indicated by several recent accidents, and specific areas for examination are identified. New educational materials and standardization activities are also noted.

Mathematical characterization of mechanical behavior of porous frictional granular media

NASA Technical Reports Server (NTRS)

Chung, T. J.; Lee, J. K.

1972-01-01

A new definition of loading and unloading along the yield surface of Roscoe and Burland is introduced. This is achieved by noting that the strain-hardening parameter in the plastic potential function is deduced from the yield locus equation of Roscoe and Burland. The analytical results are compared with the experimental results for plate-bearing and cone-penetrometer problems and close agreements are demonstrated. The wheel-soil interaction is studied under dynamic loading. The rate-dependent plasticity or viscoelastoplastic behavior is considered. This is accomplished by the internal (hidden) variables associated with time-dependent viscous properties directly superimposed with inelastic behavior governed by the yield criteria of Roscoe and Burland. Effects of inertia and energy dissipation are properly accounted for. Example problems are presented.

The intergenerational transmission of problem gambling: The mediating role of parental psychopathology.

PubMed

Dowling, N A; Shandley, K; Oldenhof, E; Youssef, G J; Thomas, S A; Frydenberg, E; Jackson, A C

2016-08-01

The present study investigated the intergenerational transmission of problem gambling and the potential mediating role of parental psychopathology (problem drinking, drug use problems, and mental health issues). The study comprised 3953 participants (1938 males, 2015 females) recruited from a large-scale Australian community telephone survey of adults retrospectively reporting on parental problem gambling and psychopathology during their childhood. Overall, 4.0% [95%CI 3.0, 5.0] (n=157) of participants reported paternal problem gambling and 1.7% [95%CI 1.0, 2.0] (n=68) reported maternal problem gambling. Compared to their peers, participants reporting paternal problem gambling were 5.1 times more likely to be moderate risk gamblers and 10.7 times more likely to be problem gamblers. Participants reporting maternal problem gambling were 1.7 times more likely to be moderate risk gamblers and 10.6 times more likely to be problem gamblers. The results revealed that the relationships between paternal-and-participant and maternal-and-participant problem gambling were significant, but that only the relationship between paternal-and-participant problem gambling remained statistically significant after controlling for maternal problem gambling and sociodemographic factors. Paternal problem drinking and maternal drug use problems partially mediated the relationship between paternal-and-participant problem gambling, and fully mediated the relationship between maternal-and-participant problem gambling. In contrast, parental mental health issues failed to significantly mediate the transmission of gambling problems by either parent. When parental problem gambling was the mediator, there was full mediation of the effect between parental psychopathology and offspring problem gambling for fathers but not mothers. Overall, the study highlights the vulnerability of children from problem gambling households and suggests that it would be of value to target prevention and intervention efforts towards this cohort. Copyright © 2016 Elsevier Ltd. All rights reserved.

Numerical Computation of Homogeneous Slope Stability

PubMed Central

Xiao, Shuangshuang; Li, Kemin; Ding, Xiaohua; Liu, Tong

2015-01-01

To simplify the computational process of homogeneous slope stability, improve computational accuracy, and find multiple potential slip surfaces of a complex geometric slope, this study utilized the limit equilibrium method to derive expression equations of overall and partial factors of safety. This study transformed the solution of the minimum factor of safety (FOS) to solving of a constrained nonlinear programming problem and applied an exhaustive method (EM) and particle swarm optimization algorithm (PSO) to this problem. In simple slope examples, the computational results using an EM and PSO were close to those obtained using other methods. Compared to the EM, the PSO had a small computation error and a significantly shorter computation time. As a result, the PSO could precisely calculate the slope FOS with high efficiency. The example of the multistage slope analysis indicated that this slope had two potential slip surfaces. The factors of safety were 1.1182 and 1.1560, respectively. The differences between these and the minimum FOS (1.0759) were small, but the positions of the slip surfaces were completely different than the critical slip surface (CSS). PMID:25784927

Numerical computation of homogeneous slope stability.

PubMed

Xiao, Shuangshuang; Li, Kemin; Ding, Xiaohua; Liu, Tong

2015-01-01

To simplify the computational process of homogeneous slope stability, improve computational accuracy, and find multiple potential slip surfaces of a complex geometric slope, this study utilized the limit equilibrium method to derive expression equations of overall and partial factors of safety. This study transformed the solution of the minimum factor of safety (FOS) to solving of a constrained nonlinear programming problem and applied an exhaustive method (EM) and particle swarm optimization algorithm (PSO) to this problem. In simple slope examples, the computational results using an EM and PSO were close to those obtained using other methods. Compared to the EM, the PSO had a small computation error and a significantly shorter computation time. As a result, the PSO could precisely calculate the slope FOS with high efficiency. The example of the multistage slope analysis indicated that this slope had two potential slip surfaces. The factors of safety were 1.1182 and 1.1560, respectively. The differences between these and the minimum FOS (1.0759) were small, but the positions of the slip surfaces were completely different than the critical slip surface (CSS).

Feasibility and potential efficacy of the family-centered Prevent-Teach-Reinforce model with families of children with developmental disorders.

PubMed

Bailey, Kathleen M; Blair, Kwang-Sun Cho

2015-12-01

This study examined the feasibility and potential efficacy of the family-centered Prevent-Teach-Reinforce (PTR) model with three families of young children with an autism spectrum disorder or language delay with sensory processing problems. Particularly, the study assessed the family adherence to the PTR intervention, changes in child behavior, family use of the Individualized Behavior Rating Scale Tool (IBRST), procedural integrity, and social validity. A multiple-baseline design across families was used to examine the functional relation between parent-implemented PTR intervention and changes in child behavior. Results indicated that the family-centered PTR process was successful in promoting parents to design and implement the PTR intervention plans with fidelity, and the parents' implemented intervention plans were effective in increasing replacement behavior and decreasing problem behavior across children. The results also indicated that the parents successfully used the IBRST to monitor their child's progress and were highly satisfied with the PTR intervention process and outcomes for their children. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fast and accurate enzyme activity measurements using a chip-based microfluidic calorimeter.

PubMed

van Schie, Morten M C H; Ebrahimi, Kourosh Honarmand; Hagen, Wilfred R; Hagedoorn, Peter-Leon

2018-03-01

Recent developments in microfluidic and nanofluidic technologies have resulted in development of new chip-based microfluidic calorimeters with potential use in different fields. One application would be the accurate high-throughput measurement of enzyme activity. Calorimetry is a generic way to measure activity of enzymes, but unlike conventional calorimeters, chip-based calorimeters can be easily automated and implemented in high-throughput screening platforms. However, application of chip-based microfluidic calorimeters to measure enzyme activity has been limited due to problems associated with miniaturization such as incomplete mixing and a decrease in volumetric heat generated. To address these problems we introduced a calibration method and devised a convenient protocol for using a chip-based microfluidic calorimeter. Using the new calibration method, the progress curve of alkaline phosphatase, which has product inhibition for phosphate, measured by the calorimeter was the same as that recorded by UV-visible spectroscopy. Our results may enable use of current chip-based microfluidic calorimeters in a simple manner as a tool for high-throughput screening of enzyme activity with potential applications in drug discovery and enzyme engineering. Copyright © 2017. Published by Elsevier Inc.

Approximate labeling via graph cuts based on linear programming.

PubMed

Komodakis, Nikos; Tziritas, Georgios

2007-08-01

A new framework is presented for both understanding and developing graph-cut-based combinatorial algorithms suitable for the approximate optimization of a very wide class of Markov Random Fields (MRFs) that are frequently encountered in computer vision. The proposed framework utilizes tools from the duality theory of linear programming in order to provide an alternative and more general view of state-of-the-art techniques like the \\alpha-expansion algorithm, which is included merely as a special case. Moreover, contrary to \\alpha-expansion, the derived algorithms generate solutions with guaranteed optimality properties for a much wider class of problems, for example, even for MRFs with nonmetric potentials. In addition, they are capable of providing per-instance suboptimality bounds in all occasions, including discrete MRFs with an arbitrary potential function. These bounds prove to be very tight in practice (that is, very close to 1), which means that the resulting solutions are almost optimal. Our algorithms' effectiveness is demonstrated by presenting experimental results on a variety of low-level vision tasks, such as stereo matching, image restoration, image completion, and optical flow estimation, as well as on synthetic problems.

Automation and adaptation: Nurses' problem-solving behavior following the implementation of bar coded medication administration technology.

PubMed

Holden, Richard J; Rivera-Rodriguez, A Joy; Faye, Héléne; Scanlon, Matthew C; Karsh, Ben-Tzion

2013-08-01

The most common change facing nurses today is new technology, particularly bar coded medication administration technology (BCMA). However, there is a dearth of knowledge on how BCMA alters nursing work. This study investigated how BCMA technology affected nursing work, particularly nurses' operational problem-solving behavior. Cognitive systems engineering observations and interviews were conducted after the implementation of BCMA in three nursing units of a freestanding pediatric hospital. Problem-solving behavior, associated problems, and goals, were specifically defined and extracted from observed episodes of care. Three broad themes regarding BCMA's impact on problem solving were identified. First, BCMA allowed nurses to invent new problem-solving behavior to deal with pre-existing problems. Second, BCMA made it difficult or impossible to apply some problem-solving behaviors that were commonly used pre-BCMA, often requiring nurses to use potentially risky workarounds to achieve their goals. Third, BCMA created new problems that nurses were either able to solve using familiar or novel problem-solving behaviors, or unable to solve effectively. Results from this study shed light on hidden hazards and suggest three critical design needs: (1) ecologically valid design; (2) anticipatory control; and (3) basic usability. Principled studies of the actual nature of clinicians' work, including problem solving, are necessary to uncover hidden hazards and to inform health information technology design and redesign.

Automation and adaptation: Nurses’ problem-solving behavior following the implementation of bar coded medication administration technology

PubMed Central

Holden, Richard J.; Rivera-Rodriguez, A. Joy; Faye, Héléne; Scanlon, Matthew C.; Karsh, Ben-Tzion

2012-01-01

The most common change facing nurses today is new technology, particularly bar coded medication administration technology (BCMA). However, there is a dearth of knowledge on how BCMA alters nursing work. This study investigated how BCMA technology affected nursing work, particularly nurses’ operational problem-solving behavior. Cognitive systems engineering observations and interviews were conducted after the implementation of BCMA in three nursing units of a freestanding pediatric hospital. Problem-solving behavior, associated problems, and goals, were specifically defined and extracted from observed episodes of care. Three broad themes regarding BCMA’s impact on problem solving were identified. First, BCMA allowed nurses to invent new problem-solving behavior to deal with pre-existing problems. Second, BCMA made it difficult or impossible to apply some problem-solving behaviors that were commonly used pre-BCMA, often requiring nurses to use potentially risky workarounds to achieve their goals. Third, BCMA created new problems that nurses were either able to solve using familiar or novel problem-solving behaviors, or unable to solve effectively. Results from this study shed light on hidden hazards and suggest three critical design needs: (1) ecologically valid design; (2) anticipatory control; and (3) basic usability. Principled studies of the actual nature of clinicians’ work, including problem solving, are necessary to uncover hidden hazards and to inform health information technology design and redesign. PMID:24443642

Developing Image Processing Meta-Algorithms with Data Mining of Multiple Metrics

PubMed Central

Cunha, Alexandre; Toga, A. W.; Parker, D. Stott

2014-01-01

People often use multiple metrics in image processing, but here we take a novel approach of mining the values of batteries of metrics on image processing results. We present a case for extending image processing methods to incorporate automated mining of multiple image metric values. Here by a metric we mean any image similarity or distance measure, and in this paper we consider intensity-based and statistical image measures and focus on registration as an image processing problem. We show how it is possible to develop meta-algorithms that evaluate different image processing results with a number of different metrics and mine the results in an automated fashion so as to select the best results. We show that the mining of multiple metrics offers a variety of potential benefits for many image processing problems, including improved robustness and validation. PMID:24653748

Mixed boundary value problems in mechanics

NASA Technical Reports Server (NTRS)

Erdogan, F.

1975-01-01

Certain boundary value problems were studied over a domain D which may contain the point at infinity and may be multiply connected. Contours forming the boundary are assumed to consist of piecewise smooth arcs. Mixed boundary value problems are those with points of flux singularity on the boundary; these are points on the surface, either side of which at least one of the differential operator has different behavior. The physical system was considered to be described by two quantities, the potential and the flux type quantities. Some of the examples that were illustrated included problems in potential theory and elasticity.

Technology needs for the development of the accommodative intraocular lens

NASA Astrophysics Data System (ADS)

Nishi, Okihiro

2010-02-01

Refilling the lens capsule while preserving capsular integrity offers the potential to restore ocular accommodation. There are two persisting problems in capsular bag refilling for possible clinical application: Leakage of the injectable material through the capsular opening and capsular opacification. Numerous attempts for solving these cardinal problems have not been proven to be clinically applicable. Recently, we developed a novel capsular bag refilling procedure using a novel accommodative intraocular lens that serves as an optic as well as a plug for sealing the capsular opening. The procedure and the results of monkey experiments will be presented.

Reducing air pollutant emissions at airports by controlling aircraft ground operations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelinas, C.G.; Fan, H.S.L.

1979-02-01

Potential reductions in air pollutant emissions were determined for four stategies to control aircraft ground operations at two case study airports, Los Angeles and San Francisco International Airports. Safety, cost, and fuel savings associated with strategy implementation were examined. Two strategies, aircraft towing and shutdown of one engine during taxi operations, provided significant emission reductions. However, there are a number of safety problems associated with aircraft towing. The shutdown of one engine while taxiing was found to be the most viable strategy because of substantial emission reductions, cost benefits resulting from fuel savings, and no apparent safety problems.

A traveling-salesman-based approach to aircraft scheduling in the terminal area

NASA Technical Reports Server (NTRS)

Luenberger, Robert A.

1988-01-01

An efficient algorithm is presented, based on the well-known algorithm for the traveling salesman problem, for scheduling aircraft arrivals into major terminal areas. The algorithm permits, but strictly limits, reassigning an aircraft from its initial position in the landing order. This limitation is needed so that no aircraft or aircraft category is unduly penalized. Results indicate, for the mix of arrivals investigated, a potential increase in capacity in the 3 to 5 percent range. Furthermore, it is shown that the computation time for the algorithm grows only linearly with problem size.

Probabilistic models, learning algorithms, and response variability: sampling in cognitive development.

PubMed

Bonawitz, Elizabeth; Denison, Stephanie; Griffiths, Thomas L; Gopnik, Alison

2014-10-01

Although probabilistic models of cognitive development have become increasingly prevalent, one challenge is to account for how children might cope with a potentially vast number of possible hypotheses. We propose that children might address this problem by 'sampling' hypotheses from a probability distribution. We discuss empirical results demonstrating signatures of sampling, which offer an explanation for the variability of children's responses. The sampling hypothesis provides an algorithmic account of how children might address computationally intractable problems and suggests a way to make sense of their 'noisy' behavior. Copyright © 2014 Elsevier Ltd. All rights reserved.

Methods proposed to achieve air quality standards for mobile sources and technology surveillance.

PubMed Central

Piver, W T

1975-01-01

The methods proposed to meet the 1975 Standards of the Clean Air Act for mobile sources are alternative antiknocks, exhaust emission control devices, and alternative engine designs. Technology surveillance analysis applied to this situation is an attempt to anticipate potential public and environmental health problems from these methods, before they happen. Components of this analysis are exhaust emission characterization, environmental transport and transformation, levels of public and environmental exposure, and the influence of economics on the selection of alternative methods. The purpose of this presentation is to show trends as a result of the interaction of these different components. In no manner can these trends be interpreted explicitly as to what will really happen. Such an analysis is necessary so that public and environmental health officials have the opportunity to act on potential problems before they become manifest. PMID:50944

B-52G crew noise exposure study

NASA Astrophysics Data System (ADS)

Decker, W. H.; Nixon, C. W.

1985-08-01

The B-52G aircraft produces acoustic environments that are potentially hazardous, interfere with voice communications and may degrade task performance. Numerous reports from aircrew of high noise levels at crew location have been documented for those B-52G aircraft that have been modified with the Offensive Avionics System. To alleviate and minimize the excessive noise exposures of aircrews, a study of the noise problem in the b-52G was deemed necessary. First, in-flight noise measurements were obtained at key personnel locations on a B-52G during a typical training mission. Then, extensive laboratory analyses were conducted on these in-flight noise data. The resulting noise exposure data were evaluated in terms of the various segments of and the total flight profile relative to allowable noise exposures. Finally, recommendations were developed for short term and long term approaches toward potential improvement in the B-52G noise exposure problem.