WorldWideScience

Sample records for group-based trajectory analysis

  1. Group-based trajectory modeling (GBMT) of citations in scholarly literature: dynamic qualities of "transient" and "sticky knowledge claims"

    NARCIS (Netherlands)

    Baumgartner, S.E.; Leydesdorff, L.

    2014-01-01

    Group-based trajectory modeling (GBTM) is applied to the citation curves of articles in six journals and to all citable items in a single field of science (virology, 24 journals) to distinguish among the developmental trajectories in subpopulations. Can citation patterns of highly-cited papers be

  2. Group-based trajectory modeling to assess adherence to biologics among patients with psoriasis

    Directory of Open Access Journals (Sweden)

    Li Y

    2014-04-01

    Full Text Available Yunfeng Li,1 Huanxue Zhou,2 Beilei Cai,1 Kristijan H Kahler,1 Haijun Tian,1 Susan Gabriel,1 Steve Arcona11Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA; 2KMK Consulting Inc., Florham Park, NJ, USABackground: Proportion of days covered (PDC, a commonly used adherence metric, does not provide information about the longitudinal course of adherence to treatment over time. Group-based trajectory model (GBTM is an alternative method that overcomes this limitation.Methods: The statistical principles of GBTM and PDC were applied to assess adherence during a 12-month follow-up in psoriasis patients starting treatment with a biologic. The optimal GBTM model was determined on the basis of the balance between each model's Bayesian information criterion and the percentage of patients in the smallest group in each model. Variables potentially predictive of adherence were evaluated.Results: In all, 3,249 patients were included in the analysis. Four GBTM adherence groups were suggested by the optimal model, and patients were categorized as demonstrating continuously high adherence, high-then-low adherence, moderate-then-low adherence, or consistently moderate adherence during follow-up. For comparison, four PDC groups were constructed: PDC Group 4 (PDC ≥75%, PDC Group 3 (25%≤ PDC <50%, PDC Group 2 (PDC <25%, and PDC Group 1 (50%≤ PDC <75%. Our findings suggest that the majority of patients (97.9% from PDC Group 2 demonstrated moderate-then-low adherence, whereas 96.4% of patients from PDC Group 4 showed continuously high adherence. The remaining PDC-based categorizations did not capture patients with uniform adherence behavior based on GBTM. In PDC Group 3, 25.3%, 17.2%, and 57.5% of patients exhibited GBTM-defined consistently moderate adherence, moderate-then-low adherence, or high-then-low adherence, respectively. In PDC Group 1, 70.8%, 23.6%, and 5.7% of patients had consistently moderate adherence, high-then-low adherence, and

  3. Group-based trajectory models: a new approach to classifying and predicting long-term medication adherence.

    Science.gov (United States)

    Franklin, Jessica M; Shrank, William H; Pakes, Juliana; Sanfélix-Gimeno, Gabriel; Matlin, Olga S; Brennan, Troyen A; Choudhry, Niteesh K

    2013-09-01

    Classifying medication adherence is important for efficiently targeting adherence improvement interventions. The purpose of this study was to evaluate the use of a novel method, group-based trajectory models, for classifying patients by their long-term adherence. We identified patients who initiated a statin between June 1, 2006 and May 30, 2007 in prescription claims from CVS Caremark and evaluated adherence over the subsequent 15 months. We compared several adherence summary measures, including proportion of days covered (PDC) and trajectory models with 2-6 groups, with the observed adherence pattern, defined by monthly indicators of full adherence (defined as having ≥24 d covered of 30). We also compared the accuracy of adherence prediction based on patient characteristics when adherence was defined by either a trajectory model or PDC. In 264,789 statin initiators, the 6-group trajectory model summarized long-term adherence best (C=0.938), whereas PDC summarized less well (C=0.881). The accuracy of adherence predictions was similar whether adherence was classified by PDC or by trajectory model. Trajectory models summarized adherence patterns better than traditional approaches and were similarly predicted by covariates. Group-based trajectory models may facilitate targeting of interventions and may be useful to adjust for confounding by health-seeking behavior.

  4. The impact of covariance misspecification in group-based trajectory models for longitudinal data with non-stationary covariance structure.

    Science.gov (United States)

    Davies, Christopher E; Glonek, Gary Fv; Giles, Lynne C

    2017-08-01

    One purpose of a longitudinal study is to gain a better understanding of how an outcome of interest changes among a given population over time. In what follows, a trajectory will be taken to mean the series of measurements of the outcome variable for an individual. Group-based trajectory modelling methods seek to identify subgroups of trajectories within a population, such that trajectories that are grouped together are more similar to each other than to trajectories in distinct groups. Group-based trajectory models generally assume a certain structure in the covariances between measurements, for example conditional independence, homogeneous variance between groups or stationary variance over time. Violations of these assumptions could be expected to result in poor model performance. We used simulation to investigate the effect of covariance misspecification on misclassification of trajectories in commonly used models under a range of scenarios. To do this we defined a measure of performance relative to the ideal Bayesian correct classification rate. We found that the more complex models generally performed better over a range of scenarios. In particular, incorrectly specified covariance matrices could significantly bias the results but using models with a correct but more complicated than necessary covariance matrix incurred little cost.

  5. Trajectory Based Traffic Analysis

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Lewis-Kelham, Edwin

    2013-01-01

    -and-click analysis, due to a novel and efficient indexing structure. With the web-site daisy.aau.dk/its/spqdemo/we will demonstrate several analyses, using a very large real-world data set consisting of 1.9 billion GPS records (1.5 million trajectories) recorded from more than 13000 vehicles, and touching most...

  6. 14 CFR 417.207 - Trajectory analysis.

    Science.gov (United States)

    2010-01-01

    ... potential three-sigma trajectory dispersions about the nominal trajectory. (2) A fuel exhaustion trajectory...) Trajectory model. A final trajectory analysis must use a six-degree of freedom trajectory model to...

  7. PANTHER. Trajectory Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rintoul, Mark Daniel [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Wilson, Andrew T. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Valicka, Christopher G. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Kegelmeyer, W. Philip [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Shead, Timothy M. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Newton, Benjamin D. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Czuchlewski, Kristina Rodriguez [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    We want to organize a body of trajectories in order to identify, search for, classify and predict behavior among objects such as aircraft and ships. Existing compari- son functions such as the Fr'echet distance are computationally expensive and yield counterintuitive results in some cases. We propose an approach using feature vectors whose components represent succinctly the salient information in trajectories. These features incorporate basic information such as total distance traveled and distance be- tween start/stop points as well as geometric features related to the properties of the convex hull, trajectory curvature and general distance geometry. Additionally, these features can generally be mapped easily to behaviors of interest to humans that are searching large databases. Most of these geometric features are invariant under rigid transformation. We demonstrate the use of different subsets of these features to iden- tify trajectories similar to an exemplar, cluster a database of several hundred thousand trajectories, predict destination and apply unsupervised machine learning algorithms.

  8. Geometric Algorithms for Trajectory Analysis

    NARCIS (Netherlands)

    Staals, Frank

    2015-01-01

    Technology such as the Global Positing System (GPS) has made tracking moving entities easy and cheap. As a result there is a large amount of trajectory data available, and an increasing demand on tools and techniques to analyze such data. We consider several analysis tasks for trajectory data, and d

  9. Future Development Strategies for S Group Based on SWOT Analysis

    Institute of Scientific and Technical Information of China (English)

    Guohui; QI; Ligen; CHEN

    2014-01-01

    In recent years,the real estate development enterprises are facing the gradually increased government’s macro-control,and the increasingly fierce market competition,so it is very imperative to timely adjust and change the enterprises’ development strategies to adapt to the new development situation.With S Group as the study object,we use SWOT analysis to analyze the company’s internal and external environment,study the current situation of the company and the existing problems,and clearly point out the opportunities and challenges facing the company.Finally we put forth some targeted strategic recommendations,in order to provide a reference for the development of S Group.

  10. Analysis of Controlled Trajectory Optimization for Canard Trajectory Correction Fuze

    Institute of Scientific and Technical Information of China (English)

    郭泽荣; 李世义; 申强

    2004-01-01

    The optimization method of the canard trajectory correction fuze's controlled trajectory phase is researched by using the aerodynamics of aerocraft and the optimal control theory, the trajectory parameters of the controlled trajectory phase based on the least energy cost are determined. On the basis of determining the control starting point and the target point, the optimal trajectory and the variation rule of the normal overload with the least energy cost are provided, when there is no time restriction in the simulation process. The results provide a theoretical basis for the structure design of the canard mechanism.

  11. Soccer ball lift coefficients via trajectory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Goff, John Eric [Department of Physics, Lynchburg College, Lynchburg, VA 24501 (United States); Carre, Matt J, E-mail: goff@lynchburg.ed [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2010-07-15

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.

  12. The ESA's Space Trajectory Analysis software suite

    Science.gov (United States)

    Ortega, Guillermo

    The European Space Agency (ESA) initiated in 2005 an internal activity to develop an open source software suite involving university science departments and research institutions all over the world. This project is called the "Space Trajectory Analysis" or STA. This article describes the birth of STA and its present configuration. One of the STA aims is to promote the exchange of technical ideas, and raise knowledge and competence in the areas of applied mathematics, space engineering, and informatics at University level. Conceived as a research and education tool to support the analysis phase of a space mission, STA is able to visualize a wide range of space trajectories. These include among others ascent, re-entry, descent and landing trajectories, orbits around planets and moons, interplanetary trajectories, rendezvous trajectories, etc. The article explains that STA project is an original idea of the Technical Directorate of ESA. It was born in August 2005 to provide a framework in astrodynamics research at University level. As research and education software applicable to Academia, a number of Universities support this development by joining ESA in leading the development. ESA and Universities partnership are expressed in the STA Steering Board. Together with ESA, each University has a chair in the board whose tasks are develop, control, promote, maintain, and expand the software suite. The article describes that STA provides calculations in the fields of spacecraft tracking, attitude analysis, coverage and visibility analysis, orbit determination, position and velocity of solar system bodies, etc. STA implements the concept of "space scenario" composed of Solar system bodies, spacecraft, ground stations, pads, etc. It is able to propagate the orbit of a spacecraft where orbital propagators are included. STA is able to compute communication links between objects of a scenario (coverage, line of sight), and to represent the trajectory computations and

  13. Trajectory analysis and optimization system (TAOS) user`s manual

    Energy Technology Data Exchange (ETDEWEB)

    Salguero, D.E.

    1995-12-01

    The Trajectory Analysis and Optimization System (TAOS) is software that simulates point--mass trajectories for multiple vehicles. It expands upon the capabilities of the Trajectory Simulation and Analysis program (TAP) developed previously at Sandia National Laboratories. TAOS is designed to be a comprehensive analysis tool capable of analyzing nearly any type of three degree-of-freedom, point-mass trajectory. Trajectories are broken into segments, and within each segment, guidance rules provided by the user control how the trajectory is computed. Parametric optimization provides a powerful method for satisfying mission-planning constraints. Althrough TAOS is not interactive, its input and output files have been designed for ease of use. When compared to TAP, the capability to analyze trajectories for more than one vehicle is the primary enhancement, although numerous other small improvements have been made. This report documents the methods used in TAOS as well as the input and output file formats.

  14. Trajectory analysis and optimization system (TAOS) user`s manual

    Energy Technology Data Exchange (ETDEWEB)

    Salguero, D.E.

    1995-12-01

    The Trajectory Analysis and Optimization System (TAOS) is software that simulates point--mass trajectories for multiple vehicles. It expands upon the capabilities of the Trajectory Simulation and Analysis program (TAP) developed previously at Sandia National Laboratories. TAOS is designed to be a comprehensive analysis tool capable of analyzing nearly any type of three degree-of-freedom, point-mass trajectory. Trajectories are broken into segments, and within each segment, guidance rules provided by the user control how the trajectory is computed. Parametric optimization provides a powerful method for satisfying mission-planning constraints. Althrough TAOS is not interactive, its input and output files have been designed for ease of use. When compared to TAP, the capability to analyze trajectories for more than one vehicle is the primary enhancement, although numerous other small improvements have been made. This report documents the methods used in TAOS as well as the input and output file formats.

  15. Stochastic and fractal analysis of fracture trajectories

    Science.gov (United States)

    Bessendorf, Michael H.

    1987-01-01

    Analyses of fracture trajectories are used to investigate structures that fall between 'micro' and 'macro' scales. It was shown that fracture trajectories belong to the class of nonstationary processes. It was also found that correlation distance, which may be related to a characteristic size of a fracture process, increases with crack length. An assemblage of crack trajectory processes may be considered as a diffusive process. Chudnovsky (1981-1985) introduced a 'crack diffusion coefficient' d which reflects the ability of the material to deviate the crack trajectory from the most energetically efficient path and thus links the material toughness to its structure. For the set of fracture trajectories in AISI 304 steel, d was found to be equal to 1.04 microns. The fractal dimension D for the same set of trajectories was found to be 1.133.

  16. Soccer Ball Lift Coefficients via Trajectory Analysis

    Science.gov (United States)

    Goff, John Eric; Carre, Matt J.

    2010-01-01

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…

  17. Soccer Ball Lift Coefficients via Trajectory Analysis

    Science.gov (United States)

    Goff, John Eric; Carre, Matt J.

    2010-01-01

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…

  18. Mars Ascent Propulsion Trades with Trajectory Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, J

    2004-04-22

    Optimized trajectories to a 500 km circular orbit are calculated for vehicles having a 100 kg Mars launch mass. Staging trades, thrust optimization, and the importance of vehicle shape for drag are all taken into consideration. The high acceleration of solid rockets requires a steep trajectory for drag avoidance, followed by a relatively large circularization burn, appropriate for a second stage. Liquid thrust reduces drag, resulting in less steep trajectories which have small circularization burns. Liquid propulsion requires less total {Delta}v, and offers options for multiple stages or just one. Graphs of payload mass versus stage propellant fractions are compared for liquid and solid propulsion.

  19. Solution space analysis of Double Lunar-Swingby periodic trajectory

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The Double Lunar-Swingby(DLS)periodic trajectory is a type of large-scale trajectory in Restricted Three-Body Problem framework.First,the principium of the DLS periodic trajectory is studied,and a preliminary design of the DLS trajectory is developed by the Patched Conic method.Second,the solution space of the DLS periodic trajectory is discussed in detail and in combination with numerical simulation,a distribution about orbital parameter relationship in the solution space is given.Finally,the variations of the orbital elements with different rotation angular velocities of geocentric apsidal line are found,and two typical orbits are given according to three reference frames.It is shown that Patched Conic method is feasible for the DLS periodic trajectory solution space analysis,and the conclusions will be valuable to the deep-space exploration orbit design in future.

  20. Automated Sensitivity Analysis of Interplanetary Trajectories for Optimal Mission Design

    Science.gov (United States)

    Knittel, Jeremy; Hughes, Kyle; Englander, Jacob; Sarli, Bruno

    2017-01-01

    This work describes a suite of Python tools known as the Python EMTG Automated Trade Study Application (PEATSA). PEATSA was written to automate the operation of trajectory optimization software, simplify the process of performing sensitivity analysis, and was ultimately found to out-perform a human trajectory designer in unexpected ways. These benefits will be discussed and demonstrated on sample mission designs.

  1. Quantum hydrodynamic analysis of decoherence: quantum trajectories and stress tensor

    Energy Technology Data Exchange (ETDEWEB)

    Na, Kyungsun; Wyatt, Robert E

    2002-12-30

    Quantum trajectories, obtained by integrating equations of motion for elements of the probability fluid, are used to analyze decoherence in a model two-mode system. Analysis of trajectories, flux maps, and the stress tensor for two composite systems, in one of which the system is uncoupled from the environment, leads to a hydrodynamic interpretation of the decoherence process.

  2. Cell mechanics through analysis of cell trajectories in microfluidic channel

    Science.gov (United States)

    Bowie, Samuel; Alexeev, Alexander; Sulchek, Todd

    The understanding of dynamic cell behavior can aid in research ranging from the mechanistic causes of diseases to the development of microfluidic devices for cancer detection. Through analysis of trajectories captured from video of the cells moving in a specially designed microfluidic device, insight into the dynamic viscoelastic nature of cells can be found. The microfluidic device distinguishes cells viscoelastic properties through the use of angled ridges causing a series of compressions, resulting in differences in trajectories based on cell stiffness. Trajectories of cell passing through the device are collected using image processing methods and data mining techniques are used to relate the trajectories to cell properties obtained from experiments. Furthermore, numerical simulation of the cell and microfluidic device are used to match the experimental results from the trajectory analysis. Combination of the modeling and experimental data help to uncover how changes in cellular structures result in changes in mechanical properties.

  3. The Best Estimated Trajectory Analysis for Pad Abort One

    Science.gov (United States)

    Kutty, Prasad; Noonan, Meghan; Karlgaard, Christopher; Beck, Roger

    2011-01-01

    I. Best Estimated Trajectory (BET) objective: a) Produce reconstructed trajectory of the PA-1 flight to understand vehicle dynamics and aid other post flight analyses. b) Leverage all measurement sources taken of vehicle during flight to produce the most accurate estimate of vehicle trajectory. c) Generate trajectory reconstructions of the Crew Module (CM), Launch Abort System (LAS), and Forward Bay Cover (FBC). II. BET analysis was started immediately following the PA-1 mission and was completed in September, 2010 a) Quick look version of BET released 5/25/2010: initial repackaging of SIGI data. b) Preliminary version of BET released 7/6/2010: first blended solution using available sources of external measurements. c) Final version of BET released 9/1/2010: final blended solution using all available sources of data.

  4. Visual traffic jam analysis based on trajectory data.

    Science.gov (United States)

    Wang, Zuchao; Lu, Min; Yuan, Xiaoru; Zhang, Junping; van de Wetering, Huub

    2013-12-01

    In this work, we present an interactive system for visual analysis of urban traffic congestion based on GPS trajectories. For these trajectories we develop strategies to extract and derive traffic jam information. After cleaning the trajectories, they are matched to a road network. Subsequently, traffic speed on each road segment is computed and traffic jam events are automatically detected. Spatially and temporally related events are concatenated in, so-called, traffic jam propagation graphs. These graphs form a high-level description of a traffic jam and its propagation in time and space. Our system provides multiple views for visually exploring and analyzing the traffic condition of a large city as a whole, on the level of propagation graphs, and on road segment level. Case studies with 24 days of taxi GPS trajectories collected in Beijing demonstrate the effectiveness of our system.

  5. Analysis and Interpretation of Superresolution Single-Particle Trajectories.

    Science.gov (United States)

    Holcman, D; Hoze, N; Schuss, Z

    2015-11-01

    A large number (tens of thousands) of single molecular trajectories on a cell membrane can now be collected by superresolution methods. The data contains information about the diffusive motion of molecule, proteins, or receptors and here we review methods for its recovery by statistical analysis of the data. The information includes the forces, organization of the membrane, the diffusion tensor, the long-time behavior of the trajectories, and more. To recover the long-time behavior and statistics of long trajectories, a stochastic model of their nonequilibrium motion is required. Modeling and data analysis serve extracting novel biophysical features at an unprecedented spatiotemporal resolution. The review presents data analysis, modeling, and stochastic simulations applied in particular on surface receptors evolving in neuronal cells.

  6. Successful Aging: Multiple Trajectories and Population Heterogeneity

    OpenAIRE

    Fengyan Tang

    2014-01-01

    Following Rowe and Kahn¡¯s successful aging model, this study identified successful aging as a distinctive aging trajectory and examined gender differences in the aging process. Using the Health and Retirement Study data (2000-2008), this study applied group-based trajectory analysis to identify multiple aging trajectories in a sample of older Americans aged 65 and over (N=9,226). Six dimensions were analyzed in the multi-trajectory model: chronic disease, physical functional limitation, disa...

  7. CFD Analysis of Swing of Cricket Ball and Trajectory Prediction

    Science.gov (United States)

    G, Jithin; Tom, Josin; Ruishikesh, Kamat; Jose, Jyothish; Kumar, Sanjay

    2013-11-01

    This work aims to understand the aerodynamics associated with the flight and swing of a cricket ball and predict its flight trajectory over the course of the game: at start (smooth ball) and as the game progresses (rough ball). Asymmetric airflow over the ball due to seam orientation and surface roughness can cause flight deviation (swing). The values of Drag, Lift and Side forces which are crucial for determining the trajectory of the ball were found with the help of FLUENT using the standard K- ɛ model. Analysis was done to study how the ball velocity, spin imparted to be ball and the tilt of the seam affects the movement of the ball through air. The governing force balance equations in 3 dimensions in combination a MATLAB code which used Heun's method was used for obtaining the trajectory of the ball. The conditions for the conventional swing and reverse swing to occur were deduced from the analysis and found to be in alignment with the real life situation. Critical seam angle for maximum swing and transition speed for normal to reverse swing were found out. The obtained trajectories were compared to real life hawk eye trajectories for validation. The analysis results were in good agreement with the real life situation.

  8. Group Based Interference Alignment

    CERN Document Server

    Ma, Yanjun; Chen, Rui; Yao, Junliang

    2010-01-01

    in $K$-user single-input single-output (SISO) frequency selective fading interference channels, it is shown that the achievable multiplexing gain is almost surely $K/2$ by using interference alignment (IA). However when the signaling dimensions is limited, allocating all the resource to all the users simultaneously is not optimal. According to this problem, a group based interference alignment (GIA) scheme is proposed and a search algorithm is designed to get the group patterns and the resource allocation among them. Analysis results show that our proposed scheme achieves a higher multiplexing gain when the resource is limited.

  9. Trajectory Browser: An Online Tool for Interplanetary Trajectory Analysis and Visualization

    Science.gov (United States)

    Foster, Cyrus James

    2013-01-01

    The trajectory browser is a web-based tool developed at the NASA Ames Research Center for finding preliminary trajectories to planetary bodies and for providing relevant launch date, time-of-flight and (Delta)V requirements. The site hosts a database of transfer trajectories from Earth to planets and small-bodies for various types of missions such as rendezvous, sample return or flybys. A search engine allows the user to find trajectories meeting desired constraints on the launch window, mission duration and (Delta)V capability, while a trajectory viewer tool allows the visualization of the heliocentric trajectory and the detailed mission itinerary. The anticipated user base of this tool consists primarily of scientists and engineers designing interplanetary missions in the context of pre-phase A studies, particularly for performing accessibility surveys to large populations of small-bodies.

  10. Benchmarking Foot Trajectory Estimation Methods for Mobile Gait Analysis

    Directory of Open Access Journals (Sweden)

    Julius Hannink

    2017-08-01

    Full Text Available Mobile gait analysis systems based on inertial sensing on the shoe are applied in a wide range of applications. Especially for medical applications, they can give new insights into motor impairment in, e.g., neurodegenerative disease and help objectify patient assessment. One key component in these systems is the reconstruction of the foot trajectories from inertial data. In literature, various methods for this task have been proposed. However, performance is evaluated on a variety of datasets due to the lack of large, generally accepted benchmark datasets. This hinders a fair comparison of methods. In this work, we implement three orientation estimation and three double integration schemes for use in a foot trajectory estimation pipeline. All methods are drawn from literature and evaluated against a marker-based motion capture reference. We provide a fair comparison on the same dataset consisting of 735 strides from 16 healthy subjects. As a result, the implemented methods are ranked and we identify the most suitable processing pipeline for foot trajectory estimation in the context of mobile gait analysis.

  11. Food pattern analysis over time: unhealthful eating trajectories predict obesity.

    Science.gov (United States)

    Pachucki, M A

    2012-05-01

    Analysis of dietary patterns is prominent in nutrition literatures, yet few studies have taken advantage of multiple repeated measurements to understand the nature of individual-level changes over time in food choice, or the relation between these changes and body mass index (BMI). To investigate changes in eating patterns at the individual level across three exam periods, and to prospectively examine the relation of eating trajectories to BMI at the cohort level. The study included 3418 participants at baseline. Clinically measured BMI and dietary intake were assessed during three exam periods between 1991 and 2001 using a validated food frequency questionnaire. An individual's eating trajectory across exam periods was analyzed using sequence analysis, and then used to estimate outcomes of continuous BMI and categorical obesity status. Ordinary least squares regression models with robust standard errors were adjusted for socio-economic and demographic confounders, baseline BMI and baseline eating. A total of 66.2% (n=1614) of participants change their diet pattern during the study period, 33.8% (n=823) remain stable. After accounting for potential confounders, an unhealthful trajectory is significantly associated with a 0.42 kg m(-2) increase in BMI (confidence interval (CI): 0.1, 0.7). Those with an unhealthful trajectory are 1.79 times more likely to be overweight (relative risk ratio, 95% CI: 1.1, 2.8) and 2.4 times more likely to be obese (relative risk ratio, 95% CI: 1.3, 4.4). Moreover, a number of specific diet transitions between exams are predictive of weight gain or loss. Contextualizing an individual's current eating behaviors with an eye towards diet history may be an important boon in the reduction of obesity. Although it may not be realistic for many people to shift from the least to most healthful diet, results from this study suggest that consistent movement in an overall healthier direction is associated with less weight gain.

  12. Trajectory Browser: An online tool for interplanetary trajectory analysis and visualization

    Science.gov (United States)

    Foster, C.

    The Trajectory Browser is a web-based tool developed at the NASA Ames Research Center for finding preliminary trajectories to planetary bodies and for providing relevant launch date, time-of-flight and Δ V requirements. The site hosts a database of transfer trajectories from Earth to planets and small-bodies for various types of missions such as rendezvous, sample return or flybys. A search engine allows the user to find trajectories meeting desired constraints on the launch window, mission duration and Δ V capability, while a trajectory viewer tool allows the visualization of the heliocentric trajectory and the detailed mission itinerary. The anticipated user base of this tool consists primarily of scientists and engineers designing interplanetary missions in the context of pre-phase A studies, particularly for performing accessibility surveys to large populations of small-bodies. The educational potential of the website is also recognized for academia and the public with regards to trajectory design, a field that has generally been poorly understood by the public. The website is currently hosted on NASA-internal URL http://trajbrowser.arc.nasa.gov/ with plans for a public release in early 2013.

  13. Mars Hybrid Propulsion System Trajectory Analysis. Part I; Crew Missions

    Science.gov (United States)

    Chai, Patrick R.; Merrill, Raymond G.; Qu, Min

    2015-01-01

    NASAs Human spaceflight Architecture team is developing a reusable hybrid transportation architecture in which both chemical and electric propulsion systems are used to send crew and cargo to Mars destinations such as Phobos, Deimos, the surface of Mars, and other orbits around Mars. By combining chemical and electrical propulsion into a single space- ship and applying each where it is more effective, the hybrid architecture enables a series of Mars trajectories that are more fuel-efficient than an all chemical architecture without significant increases in flight times. This paper provides the analysis of the interplanetary segments of the three Evolvable Mars Campaign crew missions to Mars using the hybrid transportation architecture. The trajectory analysis provides departure and arrival dates and propellant needs for the three crew missions that are used by the campaign analysis team for campaign build-up and logistics aggregation analysis. Sensitivity analyses were performed to investigate the impact of mass growth, departure window, and propulsion system performance on the hybrid transportation architecture. The results and system analysis from this paper contribute to analyses of the other human spaceflight architecture team tasks and feed into the definition of the Evolvable Mars Campaign.

  14. Spin system trajectory analysis under optimal control pulses

    Science.gov (United States)

    Kuprov, Ilya

    2013-08-01

    Several methods are proposed for the analysis, visualization and interpretation of high-dimensional spin system trajectories produced by quantum mechanical simulations. It is noted that expectation values of specific observables in large spin systems often feature fast, complicated and hard-to-interpret time dynamics and suggested that populations of carefully selected subspaces of states are much easier to analyze and interpret. As an illustration of the utility of the proposed methods, it is demonstrated that the apparent "noisy" appearance of many optimal control pulses in NMR and EPR spectroscopy is an illusion - the underlying spin dynamics is shown to be smooth, orderly and very tightly controlled.

  15. Analysis of single particle trajectories: when things go wrong

    CERN Document Server

    Holcman, D; Schuss, Z

    2015-01-01

    To recover the long-time behavior and the statistics of molecular trajectories from the large number (tens of thousands) of their short fragments, obtained by super-resolution methods at the single molecule level, data analysis based on a stochastic model of their non-equilibrium motion is required. Recently, we characterized the local biophysical properties underlying receptor motion based on coarse-grained long-range interactions, corresponding to attracting potential wells of large sizes. The purpose of this letter is to discuss optimal estimators and show what happens when thing goes wrong.

  16. Eucb: A C++ program for molecular dynamics trajectory analysis

    Science.gov (United States)

    Tsoulos, Ioannis G.; Stavrakoudis, Athanassios

    2011-03-01

    Eucb is a standalone program for geometrical analysis of molecular dynamics trajectories of protein systems. The program is written in GNU C++ and it can be installed in any operating system running a C++ compiler. The program performs its analytical tasks based on user supplied keywords. The source code is freely available from http://stavrakoudis.econ.uoi.gr/eucb under LGPL 3 license. Program summaryProgram title:Eucb Catalogue identifier: AEIC_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIC_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 31 169 No. of bytes in distributed program, including test data, etc.: 297 364 Distribution format: tar.gz Programming language: GNU C++ Computer: The tool is designed and tested on GNU/Linux systems Operating system: Unix/Linux systems RAM: 2 MB Supplementary material: Sample data files are available Classification: 3 Nature of problem: Analysis of molecular dynamics trajectories. Solution method: The program finds all possible interactions according to input files and the user instructions. Then it reads all the trajectory frames and finds those frames in which these interactions occur, under certain geometrical criteria. This is a blind search, without a priori knowledge if a certain interaction occurs or not. The program exports time series of these quantities (distance, angles, etc.) and appropriate descriptive statistics. Running time: Depends on the input data and the required options.

  17. Identification of sources and long term trends for pollutants in the arctic using isentropic trajectory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mahura, A.; Jaffe, D.; Harris, J.

    2003-07-01

    The understanding of factors driving climate and ecosystem changes in the Arctic requires careful consideration of the sources, correlation and trends for anthropogenic pollutants. The database from the NOAA-CMDL Barrow Observatory (71deg.17'N, 156deg.47'W) is the longest and most complete record of pollutant measurements in the Arctic. It includes observations of carbon dioxide (CO{sub 2}), methane (CH{sub 4}), carbon monoxide (CO), ozone (O{sub 3}), aerosol scattering coefficient ({sigma}{sub sp}), aerosol number concentration (NC{sub asl}), etc. The objectives of this study are to understand the role of long-range transport to Barrow in explaining: (1) the year-to-year variations, and (2) the trends in the atmospheric chemistry record at the NOAA-CMDL Barrow observatory. The key questions we try to answer are: 1. What is the relationship between various chemical species measured at Barrow Observatory, Alaska and transport pathways at various altitudes? 2. What are the trends of species and their relation to transport patterns from the source regions? 3. What is the impact of the Prudhoe Bay emissions on the Barrow's records? To answer on these questions we apply the following main research tools. First, it is an isentropic trajectory model used to calculate the trajectories arriving at Barrow at three altitudes of 0.5, 1.5 and 3 km above sea level. Second - clustering procedure used to divide the trajectories into groups based on source regions. Third - various statistical analysis tools such as the exploratory data analysis, two component correlation analysis, trend analysis, principal components and factor analysis used to identify the relationship between various chemical species vs. source regions as a function of time. In this study, we used the chemical data from the NOAA-CMDL Barrow observatory in combination with isentropic backward trajectories from gridded ECMWF data to understand the importance of various pollutant source regions on

  18. Quantitative multivariate analysis of dynamic multicellular morphogenic trajectories.

    Science.gov (United States)

    White, Douglas E; Sylvester, Jonathan B; Levario, Thomas J; Lu, Hang; Streelman, J Todd; McDevitt, Todd C; Kemp, Melissa L

    2015-07-01

    Interrogating fundamental cell biology principles that govern tissue morphogenesis is critical to better understanding of developmental biology and engineering novel multicellular systems. Recently, functional micro-tissues derived from pluripotent embryonic stem cell (ESC) aggregates have provided novel platforms for experimental investigation; however elucidating the factors directing emergent spatial phenotypic patterns remains a significant challenge. Computational modelling techniques offer a unique complementary approach to probe mechanisms regulating morphogenic processes and provide a wealth of spatio-temporal data, but quantitative analysis of simulations and comparison to experimental data is extremely difficult. Quantitative descriptions of spatial phenomena across multiple systems and scales would enable unprecedented comparisons of computational simulations with experimental systems, thereby leveraging the inherent power of computational methods to interrogate the mechanisms governing emergent properties of multicellular biology. To address these challenges, we developed a portable pattern recognition pipeline consisting of: the conversion of cellular images into networks, extraction of novel features via network analysis, and generation of morphogenic trajectories. This novel methodology enabled the quantitative description of morphogenic pattern trajectories that could be compared across diverse systems: computational modelling of multicellular structures, differentiation of stem cell aggregates, and gastrulation of cichlid fish. Moreover, this method identified novel spatio-temporal features associated with different stages of embryo gastrulation, and elucidated a complex paracrine mechanism capable of explaining spatiotemporal pattern kinetic differences in ESC aggregates of different sizes.

  19. Ares I-X Best Estimated Trajectory Analysis and Results

    Science.gov (United States)

    Karlgaard, Christopher D.; Beck, Roger E.; Starr, Brett R.; Derry, Stephen D.; Brandon, Jay; Olds, Aaron D.

    2011-01-01

    The Ares I-X trajectory reconstruction produced best estimated trajectories of the flight test vehicle ascent through stage separation, and of the first and upper stage entries after separation. The trajectory reconstruction process combines on-board, ground-based, and atmospheric measurements to produce the trajectory estimates. The Ares I-X vehicle had a number of on-board and ground based sensors that were available, including inertial measurement units, radar, air-data, and weather balloons. However, due to problems with calibrations and/or data, not all of the sensor data were used. The trajectory estimate was generated using an Iterative Extended Kalman Filter algorithm, which is an industry standard processing algorithm for filtering and estimation applications. This paper describes the methodology and results of the trajectory reconstruction process, including flight data preprocessing and input uncertainties, trajectory estimation algorithms, output transformations, and comparisons with preflight predictions.

  20. Dynamic analysis and trajectory tracking of a tethered space robot

    Science.gov (United States)

    Soltani, Mehrzad; Keshmiri, Mehdi; Misra, Arun K.

    2016-11-01

    Dynamic analysis and trajectory tracking of a Tethered Space Robot (TSR) is investigated in this paper. A hybrid controller is used to perform the control task. It consists of two components, the first one deals with librational motion of the tether, while the second one takes care of the manipulator motion. A Nonlinear Model Predictive Control (NMPC) approach is used to control the tether libration; for this purpose, the libration is described by a single degree of freedom and the tether length rate is employed as the input to suppress the librational motion. A modified Computed Torque Method (CTM) is used to control the manipulator motion. The dynamic interaction between the manipulator motion and the librational motion is considered both in the system dynamics and control of the system. Using numerical simulations, performance of the proposed control system is evaluated for end-effector positioning as well as for trajectory tracking for two cases: a Low Earth Orbit (LEO) and the Geostationary Earth Orbit (GEO).

  1. Mars Hybrid Propulsion System Trajectory Analysis. Part II; Cargo Missions

    Science.gov (United States)

    Chai, Patrick R.; Merrill, Raymond G.; Qu, Min

    2015-01-01

    NASA's Human Spaceflight Architecture Team is developing a reusable hybrid transportation architecture in which both chemical and electric propulsion systems are used to send crew and cargo to Mars destinations such as Phobos, Deimos, the surface of Mars, and other orbits around Mars. By combining chemical and electrical propulsion into a single spaceship and applying each where it is more effective, the hybrid architecture enables a series of Mars trajectories that are more fuel-efficient than an all chemical architecture without significant increases in flight times. This paper shows the feasibility of the hybrid transportation architecture to pre-deploy cargo to Mars and Phobos in support of the Evolvable Mars Campaign crew missions. The analysis shows that the hybrid propulsion stage is able to deliver all of the current manifested payload to Phobos and Mars through the first three crew missions. The conjunction class trajectory also allows the hybrid propulsion stage to return to Earth in a timely fashion so it can be reused for additional cargo deployment. The 1,100 days total trip time allows the hybrid propulsion stage to deliver cargo to Mars every other Earth-Mars transit opportunity. For the first two Mars surface mission in the Evolvable Mars Campaign, the short trip time allows the hybrid propulsion stage to be reused for three round-trip journeys to Mars, which matches the hybrid propulsion stage's designed lifetime for three round-trip crew missions to the Martian sphere of influence.

  2. Trajectories of body mass index before the diagnosis of cardiovascular disease: a latent class trajectory analysis

    NARCIS (Netherlands)

    K. Dhana (Klodian); J.M. van Rosmalen (Joost); D. Vistisen (Dorte); M.A. Ikram (Arfan); A. Hofman (Albert); O.H. Franco (Oscar); M. Kavousi (Maryam)

    2016-01-01

    textabstractPatients with cardiovascular disease (CVD) are a heterogeneous group regarding their body mass index (BMI) levels at the time of diagnosis. To address the heterogeneity of CVD, we examined the trajectories of change in body mass index (BMI) and in other cardio-metabolic risk factors befo

  3. Hi-G electronic gated camera for precision trajectory analysis

    Science.gov (United States)

    Snyder, Donald R.; Payne, Scott; Keller, Ed; Longo, Salvatore; Caudle, Dennis E.; Walker, Dennis C.; Sartor, Mark A.; Keeler, Joe E.; Kerr, David A.; Fail, R. Wallace; Gannon, Jim; Carrol, Ernie; Jamison, Todd A.

    1997-12-01

    It is extremely difficult and expensive to determine the flight attitude and aimpoint of small maneuvering miniature air vehicles from ground based fixed or tracking photography. Telemetry alone cannot provide sufficient information bandwidth on 'what' the ground tracking is seeing and consequently 'why' it did or did not function properly. Additionally, it is anticipated that 'smart' and 'brilliant' guided vehicles now in development will require a high resolution imaging support system to determine which target and which part of a ground feature is being used for navigation or targeting. Other requirements include support of sub-component separation from developmental supersonic vehicles, where the clean separation from the container is not determinable from ground based film systems and film cameras do not survive vehicle breakup and impact. Hence, the requirement is to develop and demonstrate an imaging support system for development/testing that can provide the flight vehicle developer/analyst with imagery (combined with miniature telemetry sources) sufficient to recreate the trajectory, terminal navigation, and flight termination events. This project is a development and demonstration of a real-time, launch-rated, shuttered, electronic imager, transmitter, and analysis system. This effort demonstrated boresighted imagery from inside small flight vehicles for post flight analysis of trajectory, and capture of ground imagery during random triggered vehicle functions. The initial studies for this capability have been accomplished by the Experimental Dynamics Section of the Air Force Wright Laboratory, Armament Directorate, Eglin AFB, Florida, and the Telemetry Support Branch of the Army Material Research and Development Center at Picatinny Arsenal, New Jersey. It has been determined that at 1/10,000 of a second exposure time, new ultra-miniature CCD sensors have sufficient sensitivity to image key ground target features without blur, thereby providing data for

  4. Classifying life course trajectories : a comparison of latent class and sequence analysis

    NARCIS (Netherlands)

    Barban, Nicola; Billari, Francesco C.

    2012-01-01

    . We compare two techniques that are widely used in the analysis of life course trajectories: latent class analysis and sequence analysis. In particular, we focus on the use of these techniques as devices to obtain classes of individual life course trajectories. We first compare the consistency of t

  5. Towards analysis of growth trajectory through multimodal longitudinal MR imaging

    Science.gov (United States)

    Sadeghi, Neda; Prastawa, Marcel; Gilmore, John H.; Lin, Weili; Gerig, Guido

    2010-03-01

    The human brain undergoes significant changes in the first few years after birth, but knowledge about this critical period of development is quite limited. Previous neuroimaging studies have been mostly focused on morphometric measures such as volume and shape, although tissue property measures related to the degree of myelination and axon density could also add valuable information to our understanding of brain maturation. Our goal is to complement brain growth analysis via morphometry with the study of longitudinal tissue property changes as reflected in patterns observed in multi-modal structural MRI and DTI. Our preliminary study includes eight healthy pediatric subjects with repeated scans at the age of two weeks, one year, and two years with T1, T2, PD, and DT MRI. Analysis is driven by the registration of multiple modalities and time points within and between subjects into a common coordinate frame, followed by image intensity normalization. Quantitative tractography with diffusion and structural image parameters serves for multi-variate tissue analysis. Different patterns of rapid changes were observed in the corpus callosum and the posterior and anterior internal capsule, structures known for distinctly different myelination growth. There are significant differences in central versus peripheral white matter. We demonstrate that the combined longitudinal analysis of structural and diffusion MRI proves superior to individual modalities and might provide a better understanding of the trajectory of early neurodevelopment.

  6. Detecting Hotspots from Taxi Trajectory Data Using Spatial Cluster Analysis

    Science.gov (United States)

    Zhao, P. X.; Qin, K.; Zhou, Q.; Liu, C. K.; Chen, Y. X.

    2015-07-01

    A method of trajectory clustering based on decision graph and data field is proposed in this paper. The method utilizes data field to describe spatial distribution of trajectory points, and uses decision graph to discover cluster centres. It can automatically determine cluster parameters and is suitable to trajectory clustering. The method is applied to trajectory clustering on taxi trajectory data, which are on the holiday (May 1st, 2014), weekday (Wednesday, May 7th, 2014) and weekend (Saturday, May 10th, 2014) respectively, in Wuhan City, China. The hotspots in four hours (8:00-9:00, 12:00-13:00, 18:00-19:00 and 23:00-24:00) for three days are discovered and visualized in heat maps. In the future, we will further research the spatiotemporal distribution and laws of these hotspots, and use more data to carry out the experiments.

  7. The analysis of control trajectories using symbolic and database computing

    Science.gov (United States)

    Grossman, Robert

    1995-01-01

    This final report comprises the formal semi-annual status reports for this grant for the periods June 30-December 31, 1993, January 1-June 30, 1994, and June 1-December 31, 1994. The research supported by this grant is broadly concerned with the symbolic computation, mixed numeric-symbolic computation, and database computation of trajectories of dynamical systems, especially control systems. A review of work during the report period covers: trajectories and approximating series, the Cayley algebra of trees, actions of differential operators, geometrically stable integration algorithms, hybrid systems, trajectory stores, PTool, and other activities. A list of publications written during the report period is attached.

  8. Quantifying ataxia: ideal trajectory analysis--a technical note

    Science.gov (United States)

    McPartland, M. D.; Krebs, D. E.; Wall, C. 3rd

    2000-01-01

    We describe a quantitative method to assess repeated stair stepping stability. In both the mediolateral (ML) and anterioposterior (AP) directions, the trajectory of the subject's center of mass (COM) was compared to an ideal sinusoid. The two identified sinusoids were unique in each direction but coupled. Two dimensionless numbers-the mediolateral instability index (IML) and AP instability index (IAP)-were calculated using the COM trajectory and ideal sinusoids for each subject with larger index values resulting from less stable performance. The COM trajectories of nine nonimpaired controls and six patients diagnosed with unilateral or bilateral vestibular labyrinth hypofunction were analyzed. The average IML and IAP values of labyrinth disorder patients were respectively 127% and 119% greater than those of controls (panalysis distinguishes persons with labyrinth disorder from those without. The COM trajectories also identify movement inefficiencies attributable to vestibulopathy.

  9. Detailed analysis of structure and particle trajectories in sheared suspensions

    Science.gov (United States)

    Morris, Jeffrey; Katyal, Bhavana

    1999-11-01

    The structure and particle dynamics of sheared suspensions of hard spheres over a range of shear strength to Brownain motion (Péclet number, Pe) have been studied by detailed analysis of extended sampling of Stokesian Dynamics simulations of simple shear. The emphasis is upon large Pe. The structure has been analyzed by decomposition of the pair distribution function, g(r), into spherical harmonics; the harmonics are a complete set for the decompositon. The results indicate a profound and very marked change in structure due to shearing. It is shown that as Pe increases, the structure is increasingly distorted from teh equilibrium spherical symmetry and the number of harmonics required to recompose the original data to within an arbitrary accuracy increases, and this variation depends upon particle fraction. We present information on the content of the dominant harmonics as a function of radial distance for a pair, and interpret the results in terms of preferred directions in the material. Dynamic particle trajectories at time scales long relative to that used for the Brownian step are analyzed in a novel fashion by simple differential geometric measures, such as root mean square path curvature and torsion. Preliminary results illustrate that the path variation from mean flow correlates with the particle stress.

  10. Aerodynamic, structural, and trajectory analysis of ASTRID-1 vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Glover, L.S.; Iwaskiw, A.P.; Oursler, M.A.; Perini, L.L.; Schaefer, E.D.

    1994-02-10

    The Johns Hopkins University/Applied Physics Laboratory, JHU/API, in support of Lawrence Livermore National Laboratory, LLNL, is conducting aerodynamic, trajectory, and structural analysis of the Advanced Single Stage Technology Rapid Insertion Demonstration (ASTRID) vehicle, being launched out of Vandenberg Air Force Base (VAFB) in February 1994. The launch is designated ASTRID-1 and is the first in a series of three that will be launched out of VAFB. Launch dates for the next two flights have not been identified, but they are scheduled for the 1994-1995 time frame. The primary goal of the ASTRID-1 flight is to test the LLNL light weight thrust on demand bi-propellant pumped divert propulsion system. The system is employed as the main thrusters for the ASTRID-1 vehicle and uses hydrazine as the mono-propellant. The major conclusions are: (1) The vehicle is very stable throughout flight (stability margin = 17 to 24 inches); (2) The aerodynamic frequency and the roll rate are such that pitch-roll interactions will be small; (3) The high stability margin combined with the high launcher elevation angle makes the vehicle flight path highly sensitive to perturbations during the initial phase of flight, i.e., during the first second of flight after leaving the rail; (4) The major impact dispersions for the test flight are due to winds. The wind impact dispersions are 90% dictated by the low altitude, 0 to 1000 ft., wind conditions; and (5) In order to minimize wind dispersions, head wind conditions are favored for the launch as November VAFB mean tail winds result in land impacts. The ballistic wind methodology can be employed to assess the impact points of winds at the launch site.

  11. Design and Analysis of Optimal Ascent Trajectories for Stratospheric Airships

    Science.gov (United States)

    Mueller, Joseph Bernard

    Stratospheric airships are lighter-than-air vehicles that have the potential to provide a long-duration airborne presence at altitudes of 18-22 km. Designed to operate on solar power in the calm portion of the lower stratosphere and above all regulated air traffic and cloud cover, these vehicles represent an emerging platform that resides between conventional aircraft and satellites. A particular challenge for airship operation is the planning of ascent trajectories, as the slow moving vehicle must traverse the high wind region of the jet stream. Due to large changes in wind speed and direction across altitude and the susceptibility of airship motion to wind, the trajectory must be carefully planned, preferably optimized, in order to ensure that the desired station be reached within acceptable performance bounds of flight time and energy consumption. This thesis develops optimal ascent trajectories for stratospheric airships, examines the structure and sensitivity of these solutions, and presents a strategy for onboard guidance. Optimal ascent trajectories are developed that utilize wind energy to achieve minimum-time and minimum-energy flights. The airship is represented by a three-dimensional point mass model, and the equations of motion include aerodynamic lift and drag, vectored thrust, added mass effects, and accelerations due to mass flow rate, wind rates, and Earth rotation. A representative wind profile is developed based on historical meteorological data and measurements. Trajectory optimization is performed by first defining an optimal control problem with both terminal and path constraints, then using direct transcription to develop an approximate nonlinear parameter optimization problem of finite dimension. Optimal ascent trajectories are determined using SNOPT for a variety of upwind, downwind, and crosswind launch locations. Results of extensive optimization solutions illustrate definitive patterns in the ascent path for minimum time flights across

  12. Neutrinos in gravitational collapse. I. Analysis of trajectories

    Energy Technology Data Exchange (ETDEWEB)

    Dhurandhar, S.V.; Vishveshwara, C.V.

    1981-05-01

    The behavior of neurinos is investigated in a collapsing object. The model considered consists of the Friedmann dust interior matched onto the Schwarzchild exterior. The neutrino trajectories are taken to be null geodesics, the geometric optics approximation being valid for the relevant energy range. The matter is assumed to be transparent to the neutrinos.

  13. On cooperative patrolling: optimal trajectories, complexity analysis, and approximation algorithms

    CERN Document Server

    Pasqualetti, Fabio; Bullo, Francesco

    2011-01-01

    The subject of this work is the patrolling of an environment with the aid of a team of autonomous agents. We consider both the design of open-loop trajectories with optimal properties, and of distributed control laws converging to optimal trajectories. As performance criteria, the refresh time and the latency are considered, i.e., respectively, time gap between any two visits of the same region, and the time necessary to inform every agent about an event occurred in the environment. We associate a graph with the environment, and we study separately the case of a chain, tree, and cyclic graph. For the case of chain graph, we first describe a minimum refresh time and latency team trajectory, and we propose a polynomial time algorithm for its computation. Then, we describe a distributed procedure that steers the robots toward an optimal trajectory. For the case of tree graph, a polynomial time algorithm is developed for the minimum refresh time problem, under the technical assumption of a constant number of robo...

  14. Correlation analysis of chaotic trajectories from Chua's system

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Ramirez, Jose [Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana-Iatapalapa, Apartado Postal 55-534, Mexico, D.F. 09340 (Mexico)], E-mail: jjar@xanum.uam.mx; Rodriguez, Eduardo; Echeverria, Juan Carlos; Puebla, Hector [Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana-Iatapalapa, Apartado Postal 55-534, Mexico, D.F. 09340 (Mexico)

    2008-06-15

    Chaotic systems exhibit an erratic behavior reflected by a strong divergence of trajectories with arbitrarily close initial condition. In this way, similar to trajectories from pseudorandom number generators, chaotic trajectories can be seen as noise with some degree of correlation. This work focuses on the study of some correlation properties (i.e., scaling) of chaotic trajectories from the Chua's system. This is done by using detrended fluctuation analysis, which is a method designed for the detection of correlations in stochastic time series. It is found that, in general, Chua's trajectories behave as a Brownian motion for small time scales, while they can display a white noise-like behavior or be dominated by harmonic oscillations for large time scales.

  15. Discrimination of marine algal taxonomic groups based on fluorescence excitation emission matrix, parallel factor analysis and CHEMTAX

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaona; SURongguo; BAIYing; SHI Xiaoyong; YANG Rujun

    2014-01-01

    An in vivo three-dimensional fluorescence method for the determination of algae community structure was developed by parallel factor analysis (PARAFAC) and CHEMTAX. The PARAFAC model was applied to fluo-rescence excitation-emission matrix (EEM) of 60 algae species belonging to five divisions and 11 fluorescent components were identified according to the residual sum of squares and specificity of the composition profiles of fluorescent. By the 11 fluorescent components, the algae species at different growth stages were classified correctly at the division level using Bayesian discriminant analysis (BDA). Then the reference fluo-rescent component ratio matrix was constructed for CHEMTAX, and the EEM–PARAFAC–CHEMTAX method was developed to differentiate algae taxonomic groups. The correct discrimination ratios (CDRs) when the fluorometric method was used for single-species samples were 100% at the division level, except for Bacil-lariophyta with a CDR of 95.6%. The CDRs for the mixtures were above 94.0% for the dominant algae species and above 87.0% for the subdominant algae species. However, the CDRs of the subdominant algae species were too low to be unreliable when the relative abundance estimated was less than 15.0%. The fluorometric method was tested using the samples from the Jiaozhou Bay and the mesocosm experiments in the Xiaomai Island Bay in August 2007. The discrimination results of the dominant algae groups agreed with microscopy cell counts, as well as the subdominant algae groups of which the estimated relative abundance was above 15.0%. This technique would be of great aid when low-cost and rapid analysis is needed for samples in a large batch. The fluorometric technique has the ability to correctly identify dominant species with proper abundance both in vivo and in situ.

  16. Some considerations on velocity vector accuracy in dust trajectory analysis

    Science.gov (United States)

    Jackson, A. A.; Zook, Herbert A.

    1994-01-01

    The relative contributions of comets and asteroids to the reservoir of dust in the interplanetary medium is not known. There are direct observations of dust released from comets and there is evidence to associate the IRAS dust bands with possible collisions of asteroids in the main belt. A means towards sorting out the parent sources has been proposed in the establishment of a dust collector in orbit about the Earth. The purpose of such a facility would be to collect not only cosmic dust particles intact but also the state vectors, as they arrive at the detector, the idea being that one may combine analytical laboratory analysis of the physics and chemistry of the captured particles with orbital data in order to help distinguish between bodies and identify parent bodies. The theoretical study of dust particle orbits in the solar system takes on greatly more importance if we use collected trajectory data. The orbital motion of dust when radiation and forces alone are acting is well understood. When gravitational forces due to the planets are included, the motion can become quite complex. In order to characterize the orbits of particles as they crossed the Earth's orbits, a study of the long-time dust orbital evolution was undertaken. We have considered various parameters associated with these dust orbits to see if one may in a general way discriminate between particles evolved from comets and asteroids. We proceed in this study as we have done previously. That is, we considered the dust particles as ideal black bodies, of density 1 gm/cc, spherical, with radii 10-100 microns. Particles of this size are affected by radiation forces, photon pressure, and Poynting-Robertson drag. Account was also taken of solar wind drag, which amounts to about 30 percent of the Poynting-Robertson drag negligible. The gravitational forces due to the planets are included, unlike in our previous study; the planetary orbits are those of true n-body interaction so that the possibility of

  17. Population Differentiations and Phylogenetic Analysis of Tibet and Qinghai Tibetan Groups Based on 30 InDel Loci.

    Science.gov (United States)

    Guo, Yuxin; Shen, Chunmei; Meng, Haotian; Dong, Qian; Kong, Tingting; Yang, Chunhua; Wang, Hongdan; Jin, Rui; Zhu, Bofeng

    2016-12-01

    In recent years, Insertion/Deletion (InDel) polymorphisms have become a hot area of forensic research. In this study, 30 InDel loci were selected to investigate the genetic polymorphisms of Tibetan groups, which are from Tibet Autonomous Region and Qinghai province of China, and explore the genetic relationships between Tibetan groups and other groups. Allele frequencies of the 30 InDel loci ranged from 0.1219 (HLD111) to 0.5609 (HLD57) in the Tibet Tibetan group and 0.1639 (HLD118) to 0.5655 (HLD124) in the Qinghai Tibetan group. The combined power of discrimination, matching probability, and power of exclusion were 0.999999999986, 0.999999988, and 0.9913 in the Tibet Tibetan group, respectively, and 0.99999999999204, 0.9999999796, and 0.9862 in the Qinghai Tibetan group. The results of principal component analysis, phylogenetic tree, and population structure demonstrated that the four Tibetan groups (Tibetan1, Tibetan2, Tibet, and Qinghai Tibetan groups) clustered together and had relatively close genetic relationships with nine Asian groups and then European and Amerindian groups.

  18. Optimization and Sensitivity Analysis for a Launch Trajectory

    Science.gov (United States)

    2014-12-01

    Finding solutions to a boundary value problem can be time consuming and difficult due to the twin curses of sensitivity and dimensionality. In an...Hamiltonian boundary value problem. Finding solutions to a boundary value problem can be time consuming and difficult due to the twin curses of...case performance to be identified. This knowledge will lead to more flexibility in the launch window and a more reliable launch trajectory. D

  19. Analysis of Trajectory Flexibility Preservation Impact on Traffic Complexity

    Science.gov (United States)

    Idris, Husni; El-Wakil, Tarek; Wing, David J.

    2009-01-01

    The growing demand for air travel is increasing the need for mitigation of air traffic congestion and complexity problems, which are already at high levels. At the same time new information and automation technologies are enabling the distribution of tasks and decisions from the service providers to the users of the air traffic system, with potential capacity and cost benefits. This distribution of tasks and decisions raises the concern that independent user actions will decrease the predictability and increase the complexity of the traffic system, hence inhibiting and possibly reversing any potential benefits. In answer to this concern, the authors proposed the introduction of decision-making metrics for preserving user trajectory flexibility. The hypothesis is that such metrics will make user actions naturally mitigate traffic complexity. In this paper, the impact of using these metrics on traffic complexity is investigated. The scenarios analyzed include aircraft in en route airspace with each aircraft meeting a required time of arrival in a one-hour time horizon while mitigating the risk of loss of separation with the other aircraft, thus preserving its trajectory flexibility. The experiments showed promising results in that the individual trajectory flexibility preservation induced self-separation and self-organization effects in the overall traffic situation. The effects were quantified using traffic complexity metrics, namely dynamic density indicators, which indicated that using the flexibility metrics reduced aircraft density and the potential of loss of separation.

  20. Practices and Trajectories: a comparative analysis of reading in France, Norway, Netherlands, UK and USA

    OpenAIRE

    Southerton, Dale; Olsen, Wendy; Warde, Alan; Cheng, Shu-li

    2013-01-01

    Practices and Trajectories: a comparative analysis of reading in France, Norway, Netherlands, UK and USADale Southerton, Wendy Olsen, Alan Warde, (all at University of Manchester), & Shu-Li Cheng (Institute of Statistical Science, China) PRE-PROOF VERSION – ACCEPTED FOR PUBLICATION IN JOURNAL OF CONSUMER CULTURE 2013AbstractUsing time diary data to examine practices of reading, this article examines trajectories of change within five countries in the last quarter of the 20th century. It e...

  1. Orbiter/carrier separation for the ALT free flight no. 1 reference trajectories. Mission planning, mission analysis and software formulation

    Science.gov (United States)

    Glenn, G. M.

    1976-01-01

    Details of the generation of the separation trajectories are discussed. The analysis culminated in definition of separation trajectories between physical separation and orbiter/carrier vortex clearance. Specifications, assumptions and analytical approach used to generate the separation trajectories are presented. Results of the analytical approach are evaluated. Conclusions and recommendations are summarized. Supporting references are listed.

  2. Family income trajectory during childhood is associated with adiposity in adolescence: a latent class growth analysis

    Directory of Open Access Journals (Sweden)

    Kendzor Darla E

    2012-08-01

    Full Text Available Abstract Background Childhood socioeconomic disadvantage has been linked with obesity in cross-sectional research, although less is known about how changes in socioeconomic status influence the development of obesity. Researchers have hypothesized that upward socioeconomic mobility may attenuate the health effects of earlier socioeconomic disadvantage; while downward socioeconomic mobility might have a negative influence on health despite relative socioeconomic advantages at earlier stages. The purpose of the current study was to characterize trajectories of family income during childhood, and to evaluate the influence of these trajectories on adiposity at age 15. Methods Data were collected as part of the Study of Early Child Care and Youth Development (SECCYD between 1991 and 2007 at 10 sites across the United States. A latent class growth analysis (LCGA was conducted to identify trajectories of family income from birth to 15 years of age. Analyses of covariance (ANCOVAs were conducted to determine whether measures of adiposity differed by trajectory, while controlling for relevant covariates. Results The LCGA supported a 5-class trajectory model, which included two stable, one downward, and two upward trajectories. ANCOVAs indicated that BMI percentile, waist circumference, and skinfold thicknesses at age 15 differed significantly by trajectory, such that those who experienced downward mobility or stable low income had greater adiposity relative to the more advantaged trajectories. Conversely, upwardly mobile children and those with consistently adequate incomes had similar and more positive outcomes relative to the most disadvantaged trajectories. Conclusions Findings suggest that promoting upward socioeconomic mobility among disadvantaged families may have a positive impact on obesity-related outcomes in adolescence.

  3. Relation of air mass history to nucleation events in Po Valley, Italy, using back trajectories analysis

    Directory of Open Access Journals (Sweden)

    L. Sogacheva

    2006-11-01

    Full Text Available In this paper, we study the transport of air mass to San Pietro Capofiume (SPC in Po Valley, Italy, by means of back trajectory analysis. Our main aim is to investigate whether air masses originate from different regions on nucleation event days and on nonevent days, during three years when nucleation events have been continuously recorded at SPC. The results indicate that nucleation events occur frequently in air masses arriving form Central Europe, whereas event frequency is much lower in air transported from southern directions and from the Atlantic Ocean. We also analyzed the behaviour of meteorological parameters during 96 h transport to SPC, and found that on average, event trajectories undergo stronger subsidence during the last 12 h before the arrival at SPC than nonevent trajectories. This causes a reversal in the temperature and relative humidity (RH differences between event and nonevent trajectories: between 96 and 12 h back time, temperatures are lower and RH's higher for event than nonevent trajectories and between 12 and 0 h vice versa. Boundary layer mixing is stronger along the event trajectories compared to nonevent trajectories. The absolute humidity (AH is similar for the event and nonevent trajectories between about 96 h and about 60 h back time, but after that, the event trajectories AH becomes lower due to stronger rain. We also studied transport of SO2 to SPC, and conclude that although sources in Po Valley most probably dominate the measured concentrations, certain Central and Eastern European sources can also have a non-negligible contribution.

  4. Monte Carlo Analysis as a Trajectory Design Driver for the TESS Mission

    Science.gov (United States)

    Nickel, Craig; Lebois, Ryan; Lutz, Stephen; Dichmann, Donald; Parker, Joel

    2016-01-01

    The Transiting Exoplanet Survey Satellite (TESS) will be injected into a highly eccentric Earth orbit and fly 3.5 phasing loops followed by a lunar flyby to enter a mission orbit with lunar 2:1 resonance. Through the phasing loops and mission orbit, the trajectory is significantly affected by lunar and solar gravity. We have developed a trajectory design to achieve the mission orbit and meet mission constraints, including eclipse avoidance and a 30-year geostationary orbit avoidance requirement. A parallelized Monte Carlo simulation was performed to validate the trajectory after injecting common perturbations, including launch dispersions, orbit determination errors, and maneuver execution errors. The Monte Carlo analysis helped identify mission risks and is used in the trajectory selection process.

  5. Monte Carlo Analysis as a Trajectory Design Driver for the Transiting Exoplanet Survey Satellite (TESS) Mission

    Science.gov (United States)

    Nickel, Craig; Parker, Joel; Dichmann, Don; Lebois, Ryan; Lutz, Stephen

    2016-01-01

    The Transiting Exoplanet Survey Satellite (TESS) will be injected into a highly eccentric Earth orbit and fly 3.5 phasing loops followed by a lunar flyby to enter a mission orbit with lunar 2:1 resonance. Through the phasing loops and mission orbit, the trajectory is significantly affected by lunar and solar gravity. We have developed a trajectory design to achieve the mission orbit and meet mission constraints, including eclipse avoidance and a 30-year geostationary orbit avoidance requirement. A parallelized Monte Carlo simulation was performed to validate the trajectory after injecting common perturbations, including launch dispersions, orbit determination errors, and maneuver execution errors. The Monte Carlo analysis helped identify mission risks and is used in the trajectory selection process.

  6. Space Trajectory Error Analysis Program (STEAP) for halo orbit missions. Volume 1: Analytic and user's manual

    Science.gov (United States)

    Byrnes, D. V.; Carney, P. C.; Underwood, J. W.; Vogt, E. D.

    1974-01-01

    Development, test, conversion, and documentation of computer software for the mission analysis of missions to halo orbits about libration points in the earth-sun system is reported. The software consisting of two programs called NOMNAL and ERRAN is part of the Space Trajectories Error Analysis Programs (STEAP). The program NOMNAL targets a transfer trajectory from Earth on a given launch date to a specified halo orbit on a required arrival date. Either impulsive or finite thrust insertion maneuvers into halo orbit are permitted by the program. The transfer trajectory is consistent with a realistic launch profile input by the user. The second program ERRAN conducts error analyses of the targeted transfer trajectory. Measurements including range, doppler, star-planet angles, and apparent planet diameter are processed in a Kalman-Schmidt filter to determine the trajectory knowledge uncertainty. Execution errors at injection, midcourse correction and orbit insertion maneuvers are analyzed along with the navigation uncertainty to determine trajectory control uncertainties and fuel-sizing requirements. The program is also capable of generalized covariance analyses.

  7. Stochastic analysis of particle trajectories through river valleys

    Science.gov (United States)

    Malmon, D. V.; Dunne, T.; Reneau, S. L.

    2008-12-01

    The movement of sediment through fluvial systems includes short episodes of transport separated by long periods of particle storage in fluvial sediment storage reservoirs such as floodplains. The trajectory of a particle through a valley floor containing sediment storage reservoirs can be modeled as a random process, consisting of a series of mobilization, transport, and deposition events. The probabilities of these events are determined by the rates of sediment transport and exchange in the valley floor, and by the masses of well- mixed storage reservoirs (i.e., the sediment budget). We developed and formalized a probabilistic theory of particle trajectories through alluvial valley floors by casting the movement of a particle as a finite Markov chain, a stochastic process in which the movement from one state to the next is determined by the transition probabilities among storage states. Transition probabilities for a valley floor in steady state with respect to sediment storage can be directly computed from the sediment budget using a simple set of equations. The transition probability matrix can be used to compute probability distributions of sediment residence times within valley floor storage elements, and to predict the fate of sediment-bound constituents such as pollutants, nutrients, and tracers. The theory was tested by modeling the redistribution and radioactive decay of particle-bound 137Cs in a small alluvial valley downstream of Los Alamos, New Mexico, and comparing the modeled distribution in 1997 with an independent map of 137Cs storage in that year. The study area is a sand-dominated valley with an ephemeral channel and a narrow floodplain, which is approximately in steady-state with respect to sediment storage over several decades. The results show that this approach can be used to route particle-bound tracers through alluvial valleys with temporary sediment storage reservoirs, analyze the impacts of upstream mitigation on downstream sediment and

  8. Trajectory Correction and Locomotion Analysis of a Hexapod Walking Robot with Semi-Round Rigid Feet

    Directory of Open Access Journals (Sweden)

    Yaguang Zhu

    2016-08-01

    Full Text Available Aimed at solving the misplaced body trajectory problem caused by the rolling of semi-round rigid feet when a robot is walking, a legged kinematic trajectory correction methodology based on the Least Squares Support Vector Machine (LS-SVM is proposed. The concept of ideal foothold is put forward for the three-dimensional kinematic model modification of a robot leg, and the deviation value between the ideal foothold and real foothold is analyzed. The forward/inverse kinematic solutions between the ideal foothold and joint angular vectors are formulated and the problem of direct/inverse kinematic nonlinear mapping is solved by using the LS-SVM. Compared with the previous approximation method, this correction methodology has better accuracy and faster calculation speed with regards to inverse kinematics solutions. Experiments on a leg platform and a hexapod walking robot are conducted with multi-sensors for the analysis of foot tip trajectory, base joint vibration, contact force impact, direction deviation, and power consumption, respectively. The comparative analysis shows that the trajectory correction methodology can effectively correct the joint trajectory, thus eliminating the contact force influence of semi-round rigid feet, significantly improving the locomotion of the walking robot and reducing the total power consumption of the system.

  9. Analysis of self-overlap reveals trade-offs in plankton swimming trajectories

    DEFF Research Database (Denmark)

    Mariani, Patrizio; Visser, Andre W.; Mazzocchi, Maria Grazia

    2014-01-01

    these contrasting processes. This trade-off can be hypothesized as being evident in the behaviour of plankton, which inhabit a dilute three-dimensional environment with few refuges or orienting landmarks. We present an analysis of the swimming path geometries based on a volumetric Monte Carlo sampling approach......, which is particularly adept at revealing such trade-offs by measuring the self-overlap of the trajectories. Application of this method to experimentally measured trajectories reveals that swimming patterns in copepods are shaped to efficiently explore volumes at small scales, while achieving a large...

  10. Stereoscopic Analysis of STEREO/SECCHI Data for CME Trajectory Determination

    Science.gov (United States)

    Liewer, P. C.; Hall, J. R.; Howard, R. A.; DeJong, E. M.; Thompson, W. T.; Thernisten, A.

    2010-01-01

    The Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) coronagraphs on the twin Solar TErrestrial RElations Observatory (STEREO) spacecraft provide simultaneous views of the corona and coronal mass ejections from two view points. Here, we analyze simultaneous image pairs using the technique of tie-pointing and triangulation (T&T) to determine the three-dimensional trajectory of seven coronal mass ejections (CMEs). The bright leading edge of a CME seen in coronagraph images results from line-of-sight integration through the CME front; the two STEREO coronagraphs see different apparent leading edges, leading to a systematic error in its three-dimensional reconstruction. We analyze this systematic error using a simple geometric model of a CME front. We validate the technique and analysis by comparing T&T trajectory determinations for seven CMEs with trajectories determined by Thernisien et al. (2009) using a forward modeling technique not susceptible to this systematic effect.

  11. Substance Use and Abuse Trajectories across Adolescence: A Latent Trajectory Analysis of a Community-Recruited Sample of Girls

    Science.gov (United States)

    Marti, C. Nathan; Stice, Eric; Springer, David W.

    2010-01-01

    We used data from a school-based study of 496 adolescent girls to identify qualitatively distinct substance use and substance abuse developmental trajectory groups and tested whether the problematic groups differed from the non-problematic groups on baseline and outcome validation variables. Results identified four substance use groups (late…

  12. MDTraj: A Modern Open Library for the Analysis of Molecular Dynamics Trajectories.

    Science.gov (United States)

    McGibbon, Robert T; Beauchamp, Kyle A; Harrigan, Matthew P; Klein, Christoph; Swails, Jason M; Hernández, Carlos X; Schwantes, Christian R; Wang, Lee-Ping; Lane, Thomas J; Pande, Vijay S

    2015-10-20

    As molecular dynamics (MD) simulations continue to evolve into powerful computational tools for studying complex biomolecular systems, the necessity of flexible and easy-to-use software tools for the analysis of these simulations is growing. We have developed MDTraj, a modern, lightweight, and fast software package for analyzing MD simulations. MDTraj reads and writes trajectory data in a wide variety of commonly used formats. It provides a large number of trajectory analysis capabilities including minimal root-mean-square-deviation calculations, secondary structure assignment, and the extraction of common order parameters. The package has a strong focus on interoperability with the wider scientific Python ecosystem, bridging the gap between MD data and the rapidly growing collection of industry-standard statistical analysis and visualization tools in Python. MDTraj is a powerful and user-friendly software package that simplifies the analysis of MD data and connects these datasets with the modern interactive data science software ecosystem in Python.

  13. Space Trajectories Error Analysis (STEAP) Programs. Volume 1: Analytic manual, update

    Science.gov (United States)

    1971-01-01

    Manual revisions are presented for the modified and expanded STEAP series. The STEAP 2 is composed of three independent but related programs: NOMAL for the generation of n-body nominal trajectories performing a number of deterministic guidance events; ERRAN for the linear error analysis and generalized covariance analysis along specific targeted trajectories; and SIMUL for testing the mathematical models used in the navigation and guidance process. The analytic manual provides general problem description, formulation, and solution and the detailed analysis of subroutines. The programmers' manual gives descriptions of the overall structure of the programs as well as the computational flow and analysis of the individual subroutines. The user's manual provides information on the input and output quantities of the programs. These are updates to N69-36472 and N69-36473.

  14. Mode Analysis for Long-Term Behavior in a Resonant Earth-Moon Trajectory

    Science.gov (United States)

    Short, Cody; Howell, Kathleen; Haapala, Amanda; Dichmann, Donald

    2016-11-01

    Trajectory design in chaotic regimes allows for the exploitation of system dynamics to achieve certain behaviors. For example, for the Transiting Exoplanet Survey Satellite (TESS) mission, the selected science orbit represents a stable option well-suited to meet the mission objectives. Extended analysis of particular solutions nearby in the phase space reveals transitions into desirable terminal modes induced by natural dynamics. This investigation explores the trajectory behavior and borrows from flow-based analysis strategies to characterize modes of such a motion. Perturbed initial states from a TESS-like orbit are evolved to supply motion suitable for contingency analysis. Through the associated analysis, mechanisms are identified that drive the spacecraft into particular modes and supply conditions necessary for such transitions.

  15. Data Flow Analysis and Visualization for Spatiotemporal Statistical Data without Trajectory Information.

    Science.gov (United States)

    Kim, Seokyeon; Jeong, Seongmin; Woo, Insoo; Jang, Yun; Maciejewski, Ross; Ebert, David

    2017-02-08

    Geographic visualization research has focused on a variety of techniques to represent and explore spatiotemporal data. The goal of those techniques is to enable users to explore events and interactions over space and time in order to facilitate the discovery of patterns, anomalies and relationships within the data. However, it is difficult to extract and visualize data flow patterns over time for non-directional statistical data without trajectory information. In this work, we develop a novel flow analysis technique to extract, represent, and analyze flow maps of non-directional spatiotemporal data unaccompanied by trajectory information. We estimate a continuous distribution of these events over space and time, and extract flow fields for spatial and temporal changes utilizing a gravity model. Then, we visualize the spatiotemporal patterns in the data by employing flow visualization techniques. The user is presented with temporal trends of geo-referenced discrete events on a map. As such, overall spatiotemporal data flow patterns help users analyze geo-referenced temporal events, such as disease outbreaks, crime patterns, etc. To validate our model, we discard the trajectory information in an origin-destination dataset and apply our technique to the data and compare the derived trajectories and the original. Finally, we present spatiotemporal trend analysis for statistical datasets including twitter data, maritime search and rescue events, and syndromic surveillance.

  16. Maximum likelihood-based analysis of photon arrival trajectories in single-molecule FRET

    Energy Technology Data Exchange (ETDEWEB)

    Waligorska, Marta [Adam Mickiewicz University, Faculty of Chemistry, Grunwaldzka 6, 60-780 Poznan (Poland); Molski, Andrzej, E-mail: amolski@amu.edu.pl [Adam Mickiewicz University, Faculty of Chemistry, Grunwaldzka 6, 60-780 Poznan (Poland)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer We study model selection and parameter recovery from single-molecule FRET experiments. Black-Right-Pointing-Pointer We examine the maximum likelihood-based analysis of two-color photon trajectories. Black-Right-Pointing-Pointer The number of observed photons determines the performance of the method. Black-Right-Pointing-Pointer For long trajectories, one can extract mean dwell times that are comparable to inter-photon times. -- Abstract: When two fluorophores (donor and acceptor) are attached to an immobilized biomolecule, anti-correlated fluctuations of the donor and acceptor fluorescence caused by Foerster resonance energy transfer (FRET) report on the conformational kinetics of the molecule. Here we assess the maximum likelihood-based analysis of donor and acceptor photon arrival trajectories as a method for extracting the conformational kinetics. Using computer generated data we quantify the accuracy and precision of parameter estimates and the efficiency of the Akaike information criterion (AIC) and the Bayesian information criterion (BIC) in selecting the true kinetic model. We find that the number of observed photons is the key parameter determining parameter estimation and model selection. For long trajectories, one can extract mean dwell times that are comparable to inter-photon times.

  17. Kick-Off Point (KOP and End of Buildup (EOB Data Analysis in Trajectory Design

    Directory of Open Access Journals (Sweden)

    Novrianti Novrianti

    2017-06-01

    Full Text Available Well X is a development well which is directionally drilled. Directional drilling is choosen because the coordinate target of Well X is above the buffer zone. The directional track plan needs accurate survey calculation in order to make the righ track for directional drilling. There are many survey calculation in directional drilling such as tangential, underbalance, average angle, radius of curvature, and mercury method. Minimum curvature method is used in this directional track plan calculation. This method is used because it gives less error than other method.  Kick-Off Point (KOP and End of Buildup (EOB analysis is done at 200 ft, 400 ft, and 600 ft depth to determine the trajectory design and optimal inclination. The hole problem is also determined in this trajectory track design. Optimal trajectory design determined at 200 ft depth because the inclination below 35º and also already reach the target quite well at 1632.28 ft TVD and 408.16 AHD. The optimal inclination at 200 ft KOP depth because the maximum inclination is 18.87º which is below 35º. Hole problem will occur if the trajectory designed at 600 ft. The problems are stuck pipe and the casing or tubing will not able to bend.

  18. Statistically optimal analysis of state-discretized trajectory data from multiple thermodynamic states

    CERN Document Server

    Wu, Hao; Rosta, Edina; Noé, Frank

    2014-01-01

    We propose a discrete transition-based reweighting analysis method (dTRAM) for analyzing configuration-space-discretized simulation trajectories produced at different thermodynamic states (temperatures, Hamiltonians, etc.) dTRAM provides maximum-likelihood estimates of stationary quantities (probabilities, free energies, expectation values) at any thermodynamic state. In contrast to the weighted histogram analysis method (WHAM), dTRAM does not require data to be sampled from global equilibrium, and can thus produce superior estimates for enhanced sampling data such as parallel/simulated tempering, replica exchange, umbrella sampling, or metadynamics. In addition, dTRAM provides optimal estimates of Markov state models (MSMs) from the discretized state-space trajectories at all thermodynamic states. Under suitable conditions, these MSMs can be used to calculate kinetic quantities (e.g. rates, timescales). In the limit of a single thermodynamic state, dTRAM estimates a maximum likelihood reversible MSM, while i...

  19. Trajectories of Diurnal Cortisol in Mothers of Children with Autism and Other Developmental Disabilities: Relations to Health and Mental Health

    Science.gov (United States)

    Dykens, Elisabeth M.; Lambert, Warren

    2013-01-01

    This study used a stress biomarker, diurnal cortisol, to identify how elevated stress in mothers of children and adults with autism and other disabilities relates to their health and mental health. Based on semi-parametric, group-based trajectory analysis of 91 mothers, two distinctive cortisol trajectories emerged: blunted (63%) or steep (37%).…

  20. Trajectories of Diurnal Cortisol in Mothers of Children with Autism and Other Developmental Disabilities: Relations to Health and Mental Health

    Science.gov (United States)

    Dykens, Elisabeth M.; Lambert, Warren

    2013-01-01

    This study used a stress biomarker, diurnal cortisol, to identify how elevated stress in mothers of children and adults with autism and other disabilities relates to their health and mental health. Based on semi-parametric, group-based trajectory analysis of 91 mothers, two distinctive cortisol trajectories emerged: blunted (63%) or steep (37%).…

  1. Maximum likelihood-based analysis of photon arrival trajectories in single-molecule FRET

    Science.gov (United States)

    Waligórska, Marta; Molski, Andrzej

    2012-07-01

    When two fluorophores (donor and acceptor) are attached to an immobilized biomolecule, anti-correlated fluctuations of the donor and acceptor fluorescence caused by Förster resonance energy transfer (FRET) report on the conformational kinetics of the molecule. Here we assess the maximum likelihood-based analysis of donor and acceptor photon arrival trajectories as a method for extracting the conformational kinetics. Using computer generated data we quantify the accuracy and precision of parameter estimates and the efficiency of the Akaike information criterion (AIC) and the Bayesian information criterion (BIC) in selecting the true kinetic model. We find that the number of observed photons is the key parameter determining parameter estimation and model selection. For long trajectories, one can extract mean dwell times that are comparable to inter-photon times.

  2. Maximum likelihood-based analysis of single-molecule photon arrival trajectories

    Science.gov (United States)

    Hajdziona, Marta; Molski, Andrzej

    2011-02-01

    In this work we explore the statistical properties of the maximum likelihood-based analysis of one-color photon arrival trajectories. This approach does not involve binning and, therefore, all of the information contained in an observed photon strajectory is used. We study the accuracy and precision of parameter estimates and the efficiency of the Akaike information criterion and the Bayesian information criterion (BIC) in selecting the true kinetic model. We focus on the low excitation regime where photon trajectories can be modeled as realizations of Markov modulated Poisson processes. The number of observed photons is the key parameter in determining model selection and parameter estimation. For example, the BIC can select the true three-state model from competing two-, three-, and four-state kinetic models even for relatively short trajectories made up of 2 × 103 photons. When the intensity levels are well-separated and 104 photons are observed, the two-state model parameters can be estimated with about 10% precision and those for a three-state model with about 20% precision.

  3. Grcarma: A fully automated task-oriented interface for the analysis of molecular dynamics trajectories.

    Science.gov (United States)

    Koukos, Panagiotis I; Glykos, Nicholas M

    2013-10-05

    We report the availability of grcarma, a program encoding for a fully automated set of tasks aiming to simplify the analysis of molecular dynamics trajectories of biological macromolecules. It is a cross-platform, Perl/Tk-based front-end to the program carma and is designed to facilitate the needs of the novice as well as those of the expert user, while at the same time maintaining a user-friendly and intuitive design. Particular emphasis was given to the automation of several tedious tasks, such as extraction of clusters of structures based on dihedral and Cartesian principal component analysis, secondary structure analysis, calculation and display of root-meansquare deviation (RMSD) matrices, calculation of entropy, calculation and analysis of variance–covariance matrices, calculation of the fraction of native contacts, etc. The program is free-open source software available immediately for download.

  4. Applications for single cell trajectory analysis in inner ear development and regeneration.

    Science.gov (United States)

    Durruthy-Durruthy, Robert; Heller, Stefan

    2015-07-01

    Single cell trajectory analysis is a computational approach that orders cells along a pseudotime axis. This temporal modeling approach allows the characterization of transitional processes such as lineage development, response to insult, and tissue regeneration. The concept can also be applied to resolve spatial organization of cells within the originating tissue. Known as temporal and spatial transcriptomics, respectively, these methods belong to the most powerful analytical techniques for quantitative gene expression data currently available. Here, we discuss three different approaches: principal component analysis, the 'Monocle' algorithm, and self-organizing maps. We use a previously published qRT-PCR dataset of single neuroblast cells isolated from the developing mouse inner ear to highlight the basic features of the three methods and their individual limitations, as well as the distinct advantages that make them useful for research on the inner ear. The complex developmental morphogenesis of the inner ear and its specific challenges such as the paucity of cells as well as important open questions such as sensory hair cell regeneration render this organ a prime target for single cell trajectory analysis strategies.

  5. JED: a Java Essential Dynamics Program for comparative analysis of protein trajectories.

    Science.gov (United States)

    David, Charles C; Singam, Ettayapuram Ramaprasad Azhagiya; Jacobs, Donald J

    2017-05-25

    Essential Dynamics (ED) is a common application of principal component analysis (PCA) to extract biologically relevant motions from atomic trajectories of proteins. Covariance and correlation based PCA are two common approaches to determine PCA modes (eigenvectors) and their eigenvalues. Protein dynamics can be characterized in terms of Cartesian coordinates or internal distance pairs. In understanding protein dynamics, a comparison of trajectories taken from a set of proteins for similarity assessment provides insight into conserved mechanisms. Comprehensive software is needed to facilitate comparative-analysis with user-friendly features that are rooted in best practices from multivariate statistics. We developed a Java based Essential Dynamics toolkit called JED to compare the ED from multiple protein trajectories. Trajectories from different simulations and different proteins can be pooled for comparative studies. JED implements Cartesian-based coordinates (cPCA) and internal distance pair coordinates (dpPCA) as options to construct covariance (Q) or correlation (R) matrices. Statistical methods are implemented for treating outliers, benchmarking sampling adequacy, characterizing the precision of Q and R, and reporting partial correlations. JED output results as text files that include transformed coordinates for aligned structures, several metrics that quantify protein mobility, PCA modes with their eigenvalues, and displacement vector (DV) projections onto the top principal modes. Pymol scripts together with PDB files allow movies of individual Q- and R-cPCA modes to be visualized, and the essential dynamics occurring within user-selected time scales. Subspaces defined by the top eigenvectors are compared using several statistical metrics to quantify similarity/overlap of high dimensional vector spaces. Free energy landscapes can be generated for both cPCA and dpPCA. JED offers a convenient toolkit that encourages best practices in applying multivariate

  6. A Six Degree of Freedom Trajectory Analysis of Spin-Stabilized Projectiles

    Science.gov (United States)

    Gkritzapis, Dimitrios N.; Panagiotopoulos, Elias E.; Margaris, Dionissios P.; Papanikas, Dimitrios G.

    2007-12-01

    A full six degrees of freedom (6-DOF) flight dynamics model is proposed for the accurate prediction of short and long-range trajectories of high and low spin-stabilized projectiles via atmospheric flight to final impact point. The projectile is assumed to be both rigid (non-flexible), and rotationally symmetric about its spin axis launched at low and high pitch angles. The projectile maneuvering motion depends on the most significant force and moment variations in addition to gravity and Magnus Effect. The computational flight analysis takes into consideration the Mach number and total angle of attack effects by means of the variable aerodynamic coefficients. For the purposes of the present work, linear interpolation has been applied from the tabulated database of McCoy's book. The aforementioned variable flight model is compared with a trajectory atmospheric motion based on appropriate constant mean values of the aerodynamic projectile coefficients. Static stability, also called gyroscopic stability, is examined as a necessary condition for stable flight motion in order to locate the initial spinning projectile rotation. Static stability examination takes into account the overturning moment variations with Mach number flight motion. The developed method gives satisfactory results compared with published data of verified experiments and computational codes on atmospheric dynamics model analysis.

  7. Statistically optimal analysis of state-discretized trajectory data from multiple thermodynamic states.

    Science.gov (United States)

    Wu, Hao; Mey, Antonia S J S; Rosta, Edina; Noé, Frank

    2014-12-07

    We propose a discrete transition-based reweighting analysis method (dTRAM) for analyzing configuration-space-discretized simulation trajectories produced at different thermodynamic states (temperatures, Hamiltonians, etc.) dTRAM provides maximum-likelihood estimates of stationary quantities (probabilities, free energies, expectation values) at any thermodynamic state. In contrast to the weighted histogram analysis method (WHAM), dTRAM does not require data to be sampled from global equilibrium, and can thus produce superior estimates for enhanced sampling data such as parallel/simulated tempering, replica exchange, umbrella sampling, or metadynamics. In addition, dTRAM provides optimal estimates of Markov state models (MSMs) from the discretized state-space trajectories at all thermodynamic states. Under suitable conditions, these MSMs can be used to calculate kinetic quantities (e.g., rates, timescales). In the limit of a single thermodynamic state, dTRAM estimates a maximum likelihood reversible MSM, while in the limit of uncorrelated sampling data, dTRAM is identical to WHAM. dTRAM is thus a generalization to both estimators.

  8. Analysis of Load-Carrying Capacity for Redundant Free-Floating Space Manipulators in Trajectory Tracking Task

    Directory of Open Access Journals (Sweden)

    Qingxuan Jia

    2014-01-01

    Full Text Available The aim of this paper is to analyze load-carrying capacity of redundant free-floating space manipulators (FFSM in trajectory tracking task. Combined with the analysis of influential factors in load-carrying process, evaluation of maximum load-carrying capacity (MLCC is described as multiconstrained nonlinear programming problem. An efficient algorithm based on repeated line search within discontinuous feasible region is presented to determine MLCC for a given trajectory of the end-effector and corresponding joint path. Then, considering the influence of MLCC caused by different initial configurations for the starting point of given trajectory, a kind of maximum payload initial configuration planning method is proposed by using PSO algorithm. Simulations are performed for a particular trajectory tracking task of the 7-DOF space manipulator, of which MLCC is evaluated quantitatively. By in-depth research of the simulation results, significant gap between the values of MLCC when using different initial configurations is analyzed, and the discontinuity of allowable load-carrying capacity is illustrated. The proposed analytical method can be taken as theoretical foundation of feasibility analysis, trajectory optimization, and optimal control of trajectory tracking task in on-orbit load-carrying operations.

  9. Automatic Analysis of Cellularity in Glioblastoma and Correlation with ADC Using Trajectory Analysis and Automatic Nuclei Counting

    Science.gov (United States)

    Burth, Sina; Kieslich, Pascal J.; Jungk, Christine; Sahm, Felix; Kickingereder, Philipp; Kiening, Karl; Unterberg, Andreas; Wick, Wolfgang; Schlemmer, Heinz-Peter; Bendszus, Martin; Radbruch, Alexander

    2016-01-01

    Objective Several studies have analyzed a correlation between the apparent diffusion coefficient (ADC) derived from diffusion-weighted MRI and the tumor cellularity of corresponding histopathological specimens in brain tumors with inconclusive findings. Here, we compared a large dataset of ADC and cellularity values of stereotactic biopsies of glioblastoma patients using a new postprocessing approach including trajectory analysis and automatic nuclei counting. Materials and Methods Thirty-seven patients with newly diagnosed glioblastomas were enrolled in this study. ADC maps were acquired preoperatively at 3T and coregistered to the intraoperative MRI that contained the coordinates of the biopsy trajectory. 561 biopsy specimens were obtained; corresponding cellularity was calculated by semi-automatic nuclei counting and correlated to the respective preoperative ADC values along the stereotactic biopsy trajectory which included areas of T1-contrast-enhancement and necrosis. Results There was a weak to moderate inverse correlation between ADC and cellularity in glioblastomas that varied depending on the approach towards statistical analysis: for mean values per patient, Spearman’s ρ = -0.48 (p = 0.002), for all trajectory values in one joint analysis Spearman’s ρ = -0.32 (p < 0.001). The inverse correlation was additionally verified by a linear mixed model. Conclusions Our data confirms a previously reported inverse correlation between ADC and tumor cellularity. However, the correlation in the current article is weaker than the pooled correlation of comparable previous studies. Hence, besides cell density, other factors, such as necrosis and edema might influence ADC values in glioblastomas. PMID:27467557

  10. Trajectories of health care service utilization and differences in patient characteristics among adults with specific chronic pain: analysis of health plan member claims

    Directory of Open Access Journals (Sweden)

    Ruetsch C

    2013-02-01

    Full Text Available Charles Ruetsch,1 Joseph Tkacz,1 Peter G Kardel,1 Andrew Howe,2 Helen Pai,2 Bennett Levitan31Health Analytics, LLC, Columbia, Maryland, 2Janssen Research & Development, Raritan, New Jersey, 3Janssen Research & Development, Titusville, New Jersey, USAIntroduction: The lack of consistency surrounding the diagnosis of chronic non-cancer pain, treatment approaches, and patient management suggests the need for further research to better characterize the chronic non-cancer pain population.Objective: The purpose of this study was to identify distinct trajectories of health care service utilization of chronic non-cancer pain patients and describe the characteristic differences between trajectory groups.Patients and methods: This study utilized the MarketScan claims databases. A total of 71,392 patients diagnosed with either low back pain or osteoarthritis between 2006 and 2009 served as the study sample. Each subject's claims data were divided into three time periods around an initial diagnosis date: pre-period, post-Year 1, and post-Year 2. Subjects were categorized as either high (H or low (L cost at each post period, resulting in the creation of four trajectory groups based on the post-Year 1 and 2 cost pattern: H-H, H-L, L-H, and L-L. Multivariate statistical tests were used to predict and discriminate between trajectory group memberships.Results: The H-H, L-H, and H-L groups each utilized significantly greater pre-period high-cost venue services, post-Year 1 outpatient services, and post-Year 1 opioids compared to the L-L group (P <0.001. Additionally, the H-H and L-H groups displayed elevated Charlson comorbidity index scores compared with the L-L group (P <0.001, with each showing increased odds of having both opioid dependence and cardiovascular disease diagnoses (P <0.01.Conclusion: This study identified patient characteristics among chronic pain patients that discriminated between different levels of post-index high-cost venue service

  11. The Effectiveness of Group-based Self-management Programmes to Improve Physical and Psychological Outcomes in Patients with Cancer: a Systematic Review and Meta-analysis of Randomised Controlled Trials.

    Science.gov (United States)

    Smith-Turchyn, J; Morgan, A; Richardson, J

    2016-05-01

    The purpose of this study was to determine if patients with cancer who participate in group-based self-management programmes have better physical and psychological outcomes than patients with cancer who do not participate in group-based self-management programmes. A literature search was conducted in Ovid MEDLINE, Embase, PsycINFO, CINAHL, CENTRAL, Web of Science and ProQUEST using the terms 'self-management' OR 'self-care' AND 'cancer' OR 'neoplasm'. Randomised controlled trials comparing outcomes for people with cancer participating in group-based self-management programmes with those not participating in these programmes were selected after screening by two reviewers. Initial searches yielded 563 articles. Two reviewers independently extracted data using piloted forms and assessed risk of bias using Cochrane's tool. Standard mean differences were calculated for continuous outcomes. The percentage of variability due to heterogeneity was assessed using I(2). A subgroup analysis was carried out where possible. Six trials were included in the review after 141 full-text articles were screened. Group-based self-management programmes were found to improve physical function [standard mean difference (95% confidence interval) = 0.34 (0.02, 0.65), P = 0.04]. No significant results were found between groups for quality of life [0.48 (-0.16, 1.11), P = 0.14] and physical activity level [0.21 (-0.07, 0.5), P = 0.15] outcomes. Group-based self-management programmes for individuals with cancer resulted in improvements in physical outcomes. However, considerable heterogeneity was found between the included studies and the quality of evidence was very low for all main outcomes. Therefore the results should be viewed with caution.

  12. Trajectory Analysis of Fuel Injection into Supersonic Cross Flow Based on Schlieren Method

    Institute of Scientific and Technical Information of China (English)

    YANG Hui; LI Feng; SUN Baigang

    2012-01-01

    Trajectory analysis of fuel injection into supersonic cross flow is studied in this paper.A directly-connected wind tunnel is constructed to provide stable supersonic freestream.Based on the test rig,the schlieren system is established to reveal the fuel injection process visually.Subsequently,the method of quantitative schlieren is adopted to obtain data of both fuel/air interface and bow shock with the aid of Photoshop and Origin.Finally,the mechanism based on two influential factors of fuel injection angle and fuel injection driven pressure,is researched by vector analysis.A dimensionless model is deduced and analyzed.The curve fitting result is achieved.The relationship between the data and the two influential factors is established.The results provide not only the quantitative characteristics of the fuel injection in supersonic cross flow but also the valuable reference for the future computational simulation.

  13. Coral population trajectories, increased disturbance and management intervention: A sensitivity analysis

    KAUST Repository

    Riegl, Bernhard

    2013-03-07

    Coral reefs distant from human population were sampled in the Red Sea and one-third showed degradation by predator outbreaks (crown-of-thorns-starfish=COTS observed in all regions in all years) or bleaching (1998, 2010). Models were built to assess future trajectories. They assumed variable coral types (slow/fast growing), disturbance frequencies (5,10,20years), mortality (equal or not), and connectivity (un/connected to un/disturbed community). Known disturbances were used to parameterize models. Present and future disturbances were estimated from remote-sensing chlorophyll and temperature data. Simulations and sensitivity analysis suggest community resilience at >20-year disturbance frequency, but degradation at higher frequency. Trajectories move from fast-grower to slow-grower dominance at intermediate disturbance frequency, then again to fast-grower dominance. A similar succession was observed in the field: Acropora to Porites to Stylophora/Pocillopora dominance on shallow reefs, and a transition from large poritids to small faviids on deep reefs. Synthesis and application: Even distant reefs are impacted by global changes. COTS impacts and bleaching were key driver of coral degradation, coral population decline could be reduced if these outbreaks and bleaching susceptibility were managed by maintaining water quality and by other interventions. Just leaving reefs alone, seems no longer a satisfactory option. 2013 The Authors. Ecology and Evolution.

  14. Comparative Analysis of VLF Signal Variation along Trajectory Induced by X-ray Solar Flares

    Indian Academy of Sciences (India)

    A. Kolarski; D. Grubor

    2015-12-01

    Comparative qualitative analysis of amplitude and phase delay variations was carried out along the trajectory of GQD/22.1 kHz and NAA/24.0 kHz VLF signal traces, propagating from Skelton (UK) and Maine (USA) toward Belgrade, induced by four isolated solar X-ray flare events occurred during the period from September 2005 to December 2006. For monitoring, recording and for storage of VLF data at the Institute of Physics in Belgrade, Serbia, the AbsPAL system was used. For modeling purposes of propagating conditions along GQD and NAA signal propagation paths, LWPCv21 program code was used. Occurred solar flare events induced lower ionosphere electron density height profile changes, causing perturbations in VLF wave propagation within Earth-ionosphere waveguides. As analyzed VLF signals characterize by different propagation parameters along trajectories from their transmitters to the Belgrade receiver site, their propagation is affected in different ways for different solar flare events and also for the same solar flare events.

  15. Coral population trajectories, increased disturbance and management intervention: a sensitivity analysis.

    Science.gov (United States)

    Riegl, Bernhard; Berumen, Michael; Bruckner, Andrew

    2013-04-01

    Coral reefs distant from human population were sampled in the Red Sea and one-third showed degradation by predator outbreaks (crown-of-thorns-starfish = COTS observed in all regions in all years) or bleaching (1998, 2010). Models were built to assess future trajectories. They assumed variable coral types (slow/fast growing), disturbance frequencies (5,10,20 years), mortality (equal or not), and connectivity (un/connected to un/disturbed community). Known disturbances were used to parameterize models. Present and future disturbances were estimated from remote-sensing chlorophyll and temperature data. Simulations and sensitivity analysis suggest community resilience at >20-year disturbance frequency, but degradation at higher frequency. Trajectories move from fast-grower to slow-grower dominance at intermediate disturbance frequency, then again to fast-grower dominance. A similar succession was observed in the field: Acropora to Porites to Stylophora/Pocillopora dominance on shallow reefs, and a transition from large poritids to small faviids on deep reefs. Synthesis and application: Even distant reefs are impacted by global changes. COTS impacts and bleaching were key driver of coral degradation, coral population decline could be reduced if these outbreaks and bleaching susceptibility were managed by maintaining water quality and by other interventions. Just leaving reefs alone, seems no longer a satisfactory option.

  16. Student trajectories in physics: the need for analysis through a socio-cultural lens

    Science.gov (United States)

    Zapata, Mara

    2010-09-01

    An analysis of student connections through time and space relative to the core discipline of physics is attempted, as viewed through the lens of actor-network-theory, by Antonia Candela. Using lenses of cultural realities, networks, and perceived power in the discourse of one specific university in the capital city of Mexico and one undergraduate physics classroom, the trajectories and itineraries of students are analyzed, relative to a physics professor's pedagogical practices. This ethnographic study then yields comparisons between Mexican undergraduate students and students from the United States. Actor network theory recognizes that the symbiotic relationship existing between an actor and a continuum of space and time is defined by the symbiotic yet interdependent relationships and networks of practice (Lemke in Downward causation: Minds, bodies, and matter 2000). As part of this study and in line with actor-network-theory, human actors and non-human participants were viewed in relation to how subjects acted and were acted upon within networks of practice. Through this forum I reflect on this work with particular focus on the issues of situatedness of actors from a sociocultural perspective and how established networks viewed within this perspective frame and subsequently impact student trajectories and itineraries. In essence I argue for a need to look at a myriad of further complexities driving the symbiotic relationships being analyzed.

  17. Optimization and Analysis on Trajectory with Multiple Constraints for Hypersonic Air-vehicle

    Directory of Open Access Journals (Sweden)

    Wei Changzhu

    2015-01-01

    Full Text Available The trajectory optimization technology is one of the key technologies for hypersonic air-vehicle. There are multiple constraints in the process of hypersonic flight, such as uncertainty of flight environment, thermal current, dynamic pressure and overload. The trajectory optimization of hypersonic air-vehicle is facing with a great challenge. This article studies the direct shooting method, the Gauss pseudo spectral method and sequential gradient-restoration algorithm, among which the direct shooting method simply makes the control variables discrete in the time domain, and obtains the status value by explicit numerical integration; Gauss pseudo spectral method makes the status variable and control variable discrete in a series of Gauss points, and constructs multinomial to approximate to the status and control variable by taking the discrete points as the nodes; sequential gradient-restoration algorithm uses iteration to meet the constraints and minimize the increment of initial value of control and status variable in order to constantly approximate to the optimal solution on condition that the constraints meet first order approximation. Finally this article conducts a numerical simulation by taking the diving segment of hypersonic air-vehicle as an example for comparative analysis on those three algorithms respectively from, such as, the initial value selection, constraint handling, convergence speed and calculation accuracy. The simulation result indicates Gauss pseudo spectral method is a method with fairly good comprehensive performance.

  18. Comparative Analysis of VLF Signal Variation along Trajectory Induced by X-ray Solar Flares

    Science.gov (United States)

    Kolarski, A.; Grubor, D.

    2015-12-01

    Comparative qualitative analysis of amplitude and phase delay variations was carried out along the trajectory of GQD/22.1 kHz and NAA/24.0 kHz VLF signal traces, propagating from Skelton (UK) and Maine (USA) toward Belgrade, induced by four isolated solar X-ray flare events occurred during the period from September 2005 to December 2006. For monitoring, recording and for storage of VLF data at the Institute of Physics in Belgrade, Serbia, the AbsPAL system was used. For modeling purposes of propagating conditions along GQD and NAA signal propagation paths, LWPCv21 program code was used. Occurred solar flare events induced lower ionosphere electron density height profile changes, causing perturbations in VLF wave propagation within Earth-ionosphere waveguides. As analyzed VLF signals characterize by different propagation parameters along trajectories from their transmitters to the Belgrade receiver site, their propagation is affected in different ways for different solar flare events and also for the same solar flare events.

  19. Source attribution of Bornean air masses by back trajectory analysis during the OP3 project

    Directory of Open Access Journals (Sweden)

    N. H. Robinson

    2011-09-01

    Full Text Available Atmospheric composition affects the radiative balance of the Earth through the creation of greenhouse gases and the formation of aerosols. The latter interact with incoming solar radiation, both directly and indirectly through their effects on cloud formation and lifetime. The tropics have a major influence on incoming sunlight however the tropical atmosphere is poorly characterised, especially outside Amazonia. The origins of air masses influencing a measurement site in a protected rainforest in Borneo, South East Asia, were assessed and the likely sources of a range of trace gases and particles were determined. This was conducted by interpreting in situ measurements made at the site in the context of ECMWF backwards air mass trajectories. Two different but complementary methods were employed to interpret the data: comparison of periods classified by cluster analysis of trajectories, and inspection of the dependence of mean measured values on geographical history of trajectories. Sources of aerosol particles, carbon monoxide and halocarbons were assessed. The likely source influences include: terrestrial organic biogenic emissions; long range transport of anthropogenic emissions; biomass burning; sulphurous emissions from marine phytoplankton, with a possible contribution from volcanoes; marine production of inorganic mineral aerosol; and marine production of halocarbons. Aerosol sub- and super-saturated water affinity was found to be dependent on source (and therefore composition, with more hygroscopic aerosol and higher numbers of cloud condensation nuclei measured in air masses of marine origin. The prevailing sector during the majority of measurements was south-easterly, which is from the direction of the coast closest to the site, with a significant influence inland from the south-west. This analysis shows that marine and terrestrial air masses have different dominant chemical sources. Comparison with the AMAZE-08 project in the Amazon

  20. Source attribution of Bornean air masses by back trajectory analysis during the OP3 project

    Directory of Open Access Journals (Sweden)

    N. H. Robinson

    2011-05-01

    Full Text Available Atmospheric composition affects the radiative balance of the Earth through the creation of greenhouse gases and the formation of aerosols. The latter interact with incoming solar radiation, both directly and indirectly through their effects on cloud formation and lifetime. The tropics have a major influence on incoming sunlight however the tropical atmosphere is poorly characterised, especially outside Amazonia. The origins of air masses influencing a measurement site in a protected rainforest in Borneo, South East Asia, were assessed and the likely sources of a range of trace gases and particles were determined. This was conducted by interpreting in situ measurements made at the site in the context of ECMWF backwards air mass trajectories. Two different but complementary methods were employed to interpret the data: comparison of periods classified by cluster analysis of trajectories, and inspection of the dependence of mean measured values on geographical history of trajectories. Sources of aerosol particles, carbon monoxide and halocarbons were assessed. The likely source influences include: terrestrial organic biogenic emissions; long range transport of anthropogenic emissions; biomass burning; sulphurous emissions from marine phytoplankton, with a possible contribution from volcanoes; marine production of inorganic mineral aerosol; and marine production of halocarbons. Aerosol sub- and super-saturated water affinity was found to be dependent on source (and therefore composition, with more hygroscopic aerosol and higher numbers of cloud condensation nuclei measured in air masses of marine origin. The prevailing sector during the majority of measurements was south-easterly, which is from the direction of the coast closest to the site, with a significant influence inland from the south-west. This analysis shows that marine and terrestrial air masses have different dominant chemical sources. Comparison with the AMAZE-08 project in the Amazon

  1. Precursors and trajectories of sensory features: qualitative analysis of infant home videos.

    Science.gov (United States)

    Freuler, Ashley; Baranek, Grace T; Watson, Linda R; Boyd, Brian A; Bulluck, John C

    2012-01-01

    OBJECTIVE. This study explored precursors and trajectories of extreme sensory patterns in children with autism spectrum disorders (ASD) compared with children with developmental delay (DD). METHOD. We conducted a retrospective analysis of home videos of 12 infants who later displayed extreme presence or absence of three sensory patterns at preschool and school age. RESULTS. In ASD, hyporesponsiveness was most evident in infancy, followed by sensory repetitions. Hyporesponsiveness appeared stable over time and also was a precursor of sensory seeking. Infants with DD had few sensory precursors. CONCLUSION. Precursors of extreme sensory features emerge early in children with ASD and appear relatively stable over time for a pattern of hyporesponsiveness but less stable for patterns of hyperresponsiveness and sensory seeking. These findings highlight the emergent nature of sensory features that may inform early identification and intervention.

  2. Geomagnetically trapped, albedo and solar energetic particles: trajectory analysis and flux reconstruction with PAMELA

    CERN Document Server

    Bruno, A; Barbarino, G C; Bazilevskaya, G A; Bellotti, R; Boezio, M; Bogomolov, E A; Bongi, M; Bonvicini, V; Bottai, S; Cafagna, F; Campana, D; Carlson, P; Casolino, M; Castellini, G; Christian, E C; De Donato, C; de Nolfo, G A; De Santis, C; De Simone, N; Di Felice, V; Galper, A M; Karelin, A V; Koldashov, S V; Koldobskiy, S; Krutkov, S Y; Kvashnin, A N; Leonov, A; Malakhov, V; Marcelli, L; Martucci, M; Mayorov, A G; Menn, W; Mergé, M; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Munini, R; Osteria, G; Palma, F; Panico, B; Papini, P; Pearce, M; Picozza, P; Ricci, M; Ricciarini, S B; Ryan, J M; Sarkar, R; Scotti, V; Simon, M; Sparvoli, R; Spillantini, P; Stochaj, S; Stozhkov, Y I; Vacchi, A; Vannuccini, E; Vasilyev, G I; Voronov, S A; Yurkin, Y T; Zampa, G; Zampa, N

    2016-01-01

    The PAMELA satellite experiment is providing comprehensive observations of the interplanetary and magnetospheric radiation in the near-Earth environment. Thanks to its identification capabilities and the semi-polar orbit, PAMELA is able to precisely measure the energetic spectra and the angular distributions of the different cosmic-ray populations over a wide latitude region, including geomagnetically trapped and albedo particles. Its observations comprise the solar energetic particle events between solar cycles 23 and 24, and the geomagnetic cutoff variations during magnetospheric storms. PAMELA's measurements are supported by an accurate analysis of particle trajectories in the Earth's magnetosphere based on a realistic geomagnetic field modeling, which allows the classification of particle populations of different origin and the investigation of the asymptotic directions of arrival.

  3. Solar energetic particle events: trajectory analysis and flux reconstruction with PAMELA

    CERN Document Server

    Bruno, A; Barbarino, G C; Bazilevskaya, G A; Bellotti, R; Boezio, M; Bogomolov, E A; Bongi, M; Bonvicini, V; Bottai, S; Bravar, U; Cafagna, F; Campana, D; Carbone, R; Carlson, P; Casolino, M; Castellini, G; Christian, E C; De Donato, C; de Nolfo, G A; De Santis, C; De Simone, N; Di Felice, V; Formato, V; Galper, A M; Karelin, A V; Koldashov, S V; Koldobskiy, S; Krutkov, S Y; Kvashnin, A N; Lee, M; Leonov, A; Malakhov, V; Marcelli, L; Martucci, M; Mayorov, A G; Menn, W; Mergè, M; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Munini, R; Osteria, G; Palma, F; Panico, B; Papini, P; Pearce, M; Picozza, P; Ricci, M; Ricciarini, S B; Ryan, J M; Sarkar, R; Scotti, V; Simon, M; Sparvoli, R; Spillantini, P; Stochaj, S; Stozhkov, Y I; Vacchi, A; Vannuccini, E; Vasilyev, G I; Voronov, S A; Yurkin, Y T; Zampa, G; Zampa, N; Zverev, V G

    2016-01-01

    The PAMELA satellite experiment is providing first direct measurements of Solar Energetic Particles (SEPs) with energies from about 80 MeV to several GeV in near-Earth space, bridging the low energy data by other space-based instruments and the Ground Level Enhancement (GLE) data by the worldwide network of neutron monitors. Its unique observational capabilities include the possibility of measuring the flux angular distribution and thus investigating possible anisotropies. This work reports the analysis methods developed to estimate the SEP energy spectra as a function of the particle pitch-angle with respect to the Interplanetary Magnetic Field (IMF) direction. The crucial ingredient is provided by an accurate simulation of the asymptotic exposition of the PAMELA apparatus, based on a realistic reconstruction of particle trajectories in the Earth's magnetosphere. As case study, the results for the May 17, 2012 event are presented.

  4. Gunshot wound trajectory analysis using forensic animation to establish relative positions of shooter and victim.

    Science.gov (United States)

    Galligan, Aisling A; Fries, Craig; Melinek, Judy

    2017-02-01

    Forensic pathologists who autopsy the victims of gun violence are often called upon to answer questions in both criminal and civil proceedings about the relative position of the shooter and the victim. In this case report of an officer-involved shooting incident, the statement of the police officer appeared to be in direct contradiction to the statements of other eyewitnesses, the evidence at the scene, and the final resting position of the decedent's body. Trajectory analysis of two gunshot wound pathways (only one of which was instantaneously incapacitating) was performed to assess the veracity of the officer's statement and forensic animation was used to create a court exhibit. A discussion of the current peer-reviewed literature is included.

  5. Using trajectory sensitivity analysis to find suitable locations of series compensators for improving rotor angle stability

    DEFF Research Database (Denmark)

    Nasri, Amin; Eriksson, Robert; Ghandhar, Mehrdad

    2014-01-01

    This paper proposes an approach based on trajectory sensitivity analysis (TSA) to find most suitable placement of series compensators in the power system. The main objective is to maximize the benefit of these devices in order to enhance the rotor angle stability. This approach is formulated...... as a two-stage problem, whose first-stage describes prior to fault occurrence and whose second-stage epresents the power system behavior involving a set of severe faults. The first-stage focuses on small signal stability, while the second-stage deals with transient stability of power system. In this vein......-machine 39-bus test system demonstrate the usefulness of the proposed method....

  6. An Analysis of the Trajectory of Intellectual Capital in a Mexican Public University

    Directory of Open Access Journals (Sweden)

    Rosa María Nava Rogel

    2011-11-01

    Full Text Available Although knowledge contributes to the creation of intellectual capital, and there are studies to measure it in European universities, in Mexico little has been generated on the subject. The aim of this paper is to propose a model constructed on the basis of an analysis of trajectories of intellectual capital at a Mexican public university, with the goal of demonstrating that the element which most strongly influences it is the human capital devoted to teaching. We reviewed previous research, observed the correlations between the components of intellectual capital, and developed the model. We obtained evidence to determine that the human capital devoted to teaching influences the human capital devoted to research, as well as the structural capital, and to a lesser degree, the relational capital.

  7. Pseudospectral method based trajectory optimization and fairing rejection time analysis of solid launch vehicle

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The problem of real-time trajectory optimization for small solid launch vehicle of operational responsive space (ORS) was studied by using pseudospectral method. According to the characteristic of the trajectory design, the dynamics model was set up in the inertia right-angled reference frame, and the equation and parameter at the orbit injection point were simplified and converted. The infinite dimension dynamic optimal control problem was converted to a finite dimension static state optimization problem and the algorithm reduced the complexity so as to become a general algorithm in trajectories optimization. With the trajectories optimization of a three-stage solid vehicle with a liquor upper stage as example, the model of the trajectory optimization was set up and simulations were carried out. The results demonstrated the advantage and validity of the pseudospectral method. The rejection time of fairing was also analyzed by the simulation results, and the optimal flight procedure and trajectory were obtained.

  8. Conformational and functional analysis of molecular dynamics trajectories by Self-Organising Maps

    Directory of Open Access Journals (Sweden)

    Stella Fabio

    2011-05-01

    Full Text Available Abstract Background Molecular dynamics (MD simulations are powerful tools to investigate the conformational dynamics of proteins that is often a critical element of their function. Identification of functionally relevant conformations is generally done clustering the large ensemble of structures that are generated. Recently, Self-Organising Maps (SOMs were reported performing more accurately and providing more consistent results than traditional clustering algorithms in various data mining problems. We present a novel strategy to analyse and compare conformational ensembles of protein domains using a two-level approach that combines SOMs and hierarchical clustering. Results The conformational dynamics of the α-spectrin SH3 protein domain and six single mutants were analysed by MD simulations. The Cα's Cartesian coordinates of conformations sampled in the essential space were used as input data vectors for SOM training, then complete linkage clustering was performed on the SOM prototype vectors. A specific protocol to optimize a SOM for structural ensembles was proposed: the optimal SOM was selected by means of a Taguchi experimental design plan applied to different data sets, and the optimal sampling rate of the MD trajectory was selected. The proposed two-level approach was applied to single trajectories of the SH3 domain independently as well as to groups of them at the same time. The results demonstrated the potential of this approach in the analysis of large ensembles of molecular structures: the possibility of producing a topological mapping of the conformational space in a simple 2D visualisation, as well as of effectively highlighting differences in the conformational dynamics directly related to biological functions. Conclusions The use of a two-level approach combining SOMs and hierarchical clustering for conformational analysis of structural ensembles of proteins was proposed. It can easily be extended to other study cases and to

  9. A Spatiotemporal Analysis of Brazilian Science from the Perspective of Researchers' Career Trajectories.

    Directory of Open Access Journals (Sweden)

    Caio Alves Furtado

    Full Text Available The growth of Brazilian scientific production in recent years is remarkable, which motivates an investigation on the factors, inside and outside the country, that helped shape this wealthy research environment. This article provides a thorough analysis of the education of researchers that constitute the main Brazilian research groups, using data on about 6,000 researchers involved in the country's National Institutes of Science and Technology (INCT initiative. Data on the steps taken by each researcher in her education, from the bachelor's degree to doctorate, including a possible postdoctoral experience, and employment, are extracted from an official curriculum vitae repository. The location and the time at which each career step occurred define spatiotemporal career trajectories. We then analyze such trajectories considering additional data, including the area of knowledge of the INCTs to which each researcher is associated. We found an increasing prevalence of Brazilian institutions in the education of Brazilian scientists, as the number of doctorates earned abroad is decreasing over time. Postdoctoral stages, on the other hand, often take place in Europe or in the United States. Taking an international postdoctoral position after a full education in Brazil suggests a drive towards seeking higher-level exchange and cooperation with foreign groups in a more advanced career stage. Results also show that Brazilian researchers tend to seek employment in regions that are close to the institutions at which they received their bachelor's degrees, suggesting low mobility within the country. This study can be instrumental in defining public policies for correcting distortions, and can help other developing countries that aim to improve their national science systems.

  10. Analysis of Spatio-Temporal Traffic Patterns Based on Pedestrian Trajectories

    Science.gov (United States)

    Busch, S.; Schindler, T.; Klinger, T.; Brenner, C.

    2016-06-01

    For driver assistance and autonomous driving systems, it is essential to predict the behaviour of other traffic participants. Usually, standard filter approaches are used to this end, however, in many cases, these are not sufficient. For example, pedestrians are able to change their speed or direction instantly. Also, there may be not enough observation data to determine the state of an object reliably, e.g. in case of occlusions. In those cases, it is very useful if a prior model exists, which suggests certain outcomes. For example, it is useful to know that pedestrians are usually crossing the road at a certain location and at certain times. This information can then be stored in a map which then can be used as a prior in scene analysis, or in practical terms to reduce the speed of a vehicle in advance in order to minimize critical situations. In this paper, we present an approach to derive such a spatio-temporal map automatically from the observed behaviour of traffic participants in everyday traffic situations. In our experiments, we use one stationary camera to observe a complex junction, where cars, public transportation and pedestrians interact. We concentrate on the pedestrians trajectories to map traffic patterns. In the first step, we extract trajectory segments from the video data. These segments are then clustered in order to derive a spatial model of the scene, in terms of a spatially embedded graph. In the second step, we analyse the temporal patterns of pedestrian movement on this graph. We are able to derive traffic light sequences as well as the timetables of nearby public transportation. To evaluate our approach, we used a 4 hour video sequence. We show that we are able to derive traffic light sequences as well as time tables of nearby public transportation.

  11. Understanding Process in Group-Based Intervention Delivery: Social Network Analysis and Intra-entity Variability Methods as Windows into the "Black Box".

    Science.gov (United States)

    Molloy Elreda, Lauren; Coatsworth, J Douglas; Gest, Scott D; Ram, Nilam; Bamberger, Katharine

    2016-11-01

    Although the majority of evidence-based programs are designed for group delivery, group process and its role in participant outcomes have received little empirical attention. Data were collected from 20 groups of participants (94 early adolescents, 120 parents) enrolled in an efficacy trial of a mindfulness-based adaptation of the Strengthening Families Program (MSFP). Following each weekly session, participants reported on their relations to group members. Social network analysis and methods sensitive to intraindividual variability were integrated to examine weekly covariation between group process and participant progress, and to predict post-intervention outcomes from levels and changes in group process. Results demonstrate hypothesized links between network indices of group process and intervention outcomes and highlight the value of this unique analytic approach to studying intervention group process.

  12. Diagnostic Analysis of Rainstorm and Backward Trajectory Simulation of Water Vapor in Jilin Province in July,2010

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The research aimed to analyze the rainstorm process and backward trajectory simulation of water vapor condition in Jilin Province in July,2010.[Method] Based on the actual situation data of routine weather chart,NCEP (2.5°×2.5°) reanalysis data per 6 h and GBL data of NOAA,the rainstorm process was carried out the diagnostic analysis of physical quantity in Jilin Province in July,2010.Moreover,HYSPLIT backward trajectory mode was used to simulate the water vapor source.[Result] The coexistence o...

  13. SharkDB: an in-memory column-oriented storage for trajectory analysis

    KAUST Repository

    Zheng, Bolong

    2017-05-05

    The last decade has witnessed the prevalence of sensor and GPS technologies that produce a high volume of trajectory data representing the motion history of moving objects. However some characteristics of trajectories such as variable lengths and asynchronous sampling rates make it difficult to fit into traditional database systems that are disk-based and tuple-oriented. Motivated by the success of column store and recent development of in-memory databases, we try to explore the potential opportunities of boosting the performance of trajectory data processing by designing a novel trajectory storage within main memory. In contrast to most existing trajectory indexing methods that keep consecutive samples of the same trajectory in the same disk page, we partition the database into frames in which the positions of all moving objects at the same time instant are stored together and aligned in main memory. We found this column-wise storage to be surprisingly well suited for in-memory computing since most frames can be stored in highly compressed form, which is pivotal for increasing the memory throughput and reducing CPU-cache miss. The independence between frames also makes them natural working units when parallelizing data processing on a multi-core environment. Lastly we run a variety of common trajectory queries on both real and synthetic datasets in order to demonstrate advantages and study the limitations of our proposed storage.

  14. Chemical and Trajectory Analysis of an Air Mass Plume from Asia

    Science.gov (United States)

    Guo, J. J.; Marrero, J. E.; Blake, D. R.

    2014-12-01

    Tracking the source of pollution events is important in understanding the transport of pollution plumes and impact on areas far from the source. Previous studies have shown that the rising contribution of Asian air pollution to the US has increased the number of days that pollution events exceed National Ambient Air Quality Standards (NAAQS). Whole air samples collected over the Edwards Air Force Base during a June 2014 NASA Student Airborne Research Program (SARP) flight exhibited enhancements in the concentrations of several compounds between 23-32 thousand feet. Chemical tracer analysis of these high altitude samples reveal that the air does not correspond to California emitted air. Chemical signatures in the plume, including high levels of OCS, chloroform, and methyl chloride, and low levels of methyl bromide, indicate that the plume was most heavily influence by coal combustion with contributions from biomass burning events from Asia. Low concentrations of ethene at the high altitude despite enhanced concentrations of ethane and ethyne suggest that this plume was aged. Further analysis of the plume using meteorological wind trajectories reveal that the plume had originated in China approximately 4-5 days prior. This is faster than results from previous studies that had found a Spring transport time of approximately 6 days.

  15. Leg mechanics contribute to establishing swing phase trajectories during memory-guided stepping movements in walking cats: a computational analysis

    Directory of Open Access Journals (Sweden)

    Keir Gordon Pearson

    2015-09-01

    Full Text Available When quadrupeds stop walking after stepping over a barrier with their forelegs, the memory of barrier height and location is retained for many minutes. This memory is subsequently used to guide hind leg movements over the barrier when walking is resumed. The upslope of the initial trajectory of hind leg paw movements is strongly dependent on the initial location of the paw relative to the barrier. In this study, we have attempted to determine whether mechanical factors contribute significantly in establishing the slope of the paw trajectories by creating a 4-link biomechanical model of a cat hind leg and driving this model with a variety of joint-torque profiles, including average torques for a range on initial paw positions relative to the barrier. Torque profiles for individual steps were determined by an inverse dynamic analysis of leg movements in three normal cats. Our study demonstrates that limb mechanics can contribute to establishing the dependency of trajectory slope on the initial position of the paw relative to the barrier. However, an additional contribution of neuronal motor commands was indicated by the fact that the simulated slopes of paw trajectories were significantly less that the observed slopes. A neuronal contribution to the modification of paw trajectories was also revealed by our observations that both the magnitudes of knee flexor muscle EMG bursts and the initial knee flexion torques depended on initial paw position. Previous studies have shown that a shift in paw position prior to stepping over a barrier changes the paw trajectory to be appropriate for the new paw position. Our data indicate that both mechanical and neuronal factors contribute to this updating process, and that any shift in leg position during the delay period modifies the working memory of barrier location.

  16. Course trajectories of unipolar depressive disorders identified by latent class growth analysis

    NARCIS (Netherlands)

    Rhebergen, D.; Lamers, F.; Spijker, J.; Graaf, R. de; Beekman, A.T.; Penninx, B.W.J.H.

    2012-01-01

    BACKGROUND: Current classification of unipolar depression reflects the idea that prognosis is essential. However, do DSM categories of major depressive disorder (MDD), dysthymic disorder (Dysth) and double depression (DD=MDD+Dysth) indeed adequately represent clinically relevant course trajectories

  17. Course trajectories of unipolar depressive disorders identified by latent class growth analysis

    NARCIS (Netherlands)

    Rhebergen, D.; Lamers, F.; Spijker, J.; Graaf, R. de; Beekman, A.T.F.; Penninx, B.W.J.H.

    2012-01-01

    Background. Current classification of unipolar depression reflects the idea that prognosis is essential. However, do DSM categories of major depressive disorder (MDD), dysthymic disorder (Dysth) and double depression (DD=MDD+Dysth) indeed adequately represent clinically relevant course trajectories

  18. Characteristic analysis and design of near moon abort trajectory for manned lunar landing mission

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The safety of astronauts would be severely threatened if the lunar-landing spacecraft were under an emergency during the near moon phase of flight, which was far from the Earth. For the problem of mission abort caused by the main engine (service propulsion system, SPS) failure during lunar orbit insertion, firstly, the family of trajectories resulted from SPS premature shutdown and corresponding abort trajectories were analyzed; then an algorithm that can be applied to the near moon abort trajectories was proposed using patched-conic technique. The characteristics of the abort trajectory, such as energy consumption and return time of flight, were analyzed and presented. Finally, simulation examples were given to demonstrate various cases of near moon SPS failure. The results of the simulation have validated the approach proposed.

  19. TRAJECTORY-BASED ANALYSIS OF URBAN LAND-COVER CHANGE DETECTION

    Directory of Open Access Journals (Sweden)

    Y. H. Zhang

    2016-06-01

    difference water index (MNDWI that extracted from time series Landsat images. Secondly, we applied SI in similarity comparison between the observed change trajectory and the possible trajectories. Lastly, verifying the accuracy of the results. The overall accuracy in four periods is 85.7 % and the overall accuracy of each two years is about 90 % and kappa statistic is about 0.85. The results show that this method is effective for time series land-cover change detection.

  20. Feature point tracking and trajectory analysis for video imaging in cell biology.

    Science.gov (United States)

    Sbalzarini, I F; Koumoutsakos, P

    2005-08-01

    This paper presents a computationally efficient, two-dimensional, feature point tracking algorithm for the automated detection and quantitative analysis of particle trajectories as recorded by video imaging in cell biology. The tracking process requires no a priori mathematical modeling of the motion, it is self-initializing, it discriminates spurious detections, and it can handle temporary occlusion as well as particle appearance and disappearance from the image region. The efficiency of the algorithm is validated on synthetic video data where it is compared to existing methods and its accuracy and precision are assessed for a wide range of signal-to-noise ratios. The algorithm is well suited for video imaging in cell biology relying on low-intensity fluorescence microscopy. Its applicability is demonstrated in three case studies involving transport of low-density lipoproteins in endosomes, motion of fluorescently labeled Adenovirus-2 particles along microtubules, and tracking of quantum dots on the plasma membrane of live cells. The present automated tracking process enables the quantification of dispersive processes in cell biology using techniques such as moment scaling spectra.

  1. Trajectory analysis for the nucleus and dust of comet C/2013 A1 (Siding Spring)

    Energy Technology Data Exchange (ETDEWEB)

    Farnocchia, Davide; Chesley, Steven R.; Chodas, Paul W. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Tricarico, Pasquale [Planetary Science Institute, Tucson, AZ 85719 (United States); Kelley, Michael S. P.; Farnham, Tony L., E-mail: Davide.Farnocchia@jpl.nasa.gov [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)

    2014-08-01

    Comet C/2013 A1 (Siding Spring) will experience a high velocity encounter with Mars on 2014 October 19 at a distance of 135,000 km ± 5000 km from the planet center. We present a comprehensive analysis of the trajectory of both the comet nucleus and the dust tail. The nucleus of C/2013 A1 cannot impact on Mars even in the case of unexpectedly large nongravitational perturbations. Furthermore, we compute the required ejection velocities for the dust grains of the tail to reach Mars as a function of particle radius and density and heliocentric distance of the ejection. A comparison between our results and the most current modeling of the ejection velocities suggests that impacts are possible only for millimeter to centimeter size particles released more than 13 AU from the Sun. However, this level of cometary activity that far from the Sun is considered extremely unlikely. The arrival time of these particles spans a 20-minute time interval centered at 2014 October 19 at 20:09 TDB, i.e., around the time that Mars crosses the orbital plane of C/2013 A1. Ejection velocities larger than currently estimated by a factor >2 would allow impacts for smaller particles ejected as close as 3 AU from the Sun. These particles would reach Mars from 19:13 TDB to 20:40 TDB.

  2. Nonlinear dynamic analysis and optimal trajectory planning of a high-speed macro-micro manipulator

    Science.gov (United States)

    Yang, Yi-ling; Wei, Yan-ding; Lou, Jun-qiang; Fu, Lei; Zhao, Xiao-wei

    2017-09-01

    This paper reports the nonlinear dynamic modeling and the optimal trajectory planning for a flexure-based macro-micro manipulator, which is dedicated to the large-scale and high-speed tasks. In particular, a macro- micro manipulator composed of a servo motor, a rigid arm and a compliant microgripper is focused. Moreover, both flexure hinges and flexible beams are considered. By combining the pseudorigid-body-model method, the assumed mode method and the Lagrange equation, the overall dynamic model is derived. Then, the rigid-flexible-coupling characteristics are analyzed by numerical simulations. After that, the microscopic scale vibration excited by the large-scale motion is reduced through the trajectory planning approach. Especially, a fitness function regards the comprehensive excitation torque of the compliant microgripper is proposed. The reference curve and the interpolation curve using the quintic polynomial trajectories are adopted. Afterwards, an improved genetic algorithm is used to identify the optimal trajectory by minimizing the fitness function. Finally, the numerical simulations and experiments validate the feasibility and the effectiveness of the established dynamic model and the trajectory planning approach. The amplitude of the residual vibration reduces approximately 54.9%, and the settling time decreases 57.1%. Therefore, the operation efficiency and manipulation stability are significantly improved.

  3. Analysis of Single Locus Trajectories for Extracting In Vivo Chromatin Tethering Interactions.

    Directory of Open Access Journals (Sweden)

    Assaf Amitai

    2015-08-01

    Full Text Available Is it possible to extract tethering forces applied on chromatin from the statistics of a single locus trajectories imaged in vivo? Chromatin fragments interact with many partners such as the nuclear membrane, other chromosomes or nuclear bodies, but the resulting forces cannot be directly measured in vivo. However, they impact chromatin dynamics and should be reflected in particular in the motion of a single locus. We present here a method based on polymer models and statistics of single trajectories to extract the force characteristics and in particular when they are generated by the gradient of a quadratic potential well. Using numerical simulations of a Rouse polymer and live cell imaging of the MAT-locus located on the yeast Saccharomyces cerevisiae chromosome III, we recover the amplitude and the distance between the observed and the interacting monomer. To conclude, the confined trajectories we observed in vivo reflect local interaction on chromatin.

  4. On trajectory generation for flexible space crane: Inverse dynamics analysis by LATDYN

    Science.gov (United States)

    Chen, G.-S.; Housner, J. M.; Wu, S.-C.; Chang, C.-W.

    1989-01-01

    For future in-space construction facility, one or more space cranes capable of manipulating and positioning large and massive spacecraft components will be needed. Inverse dynamics was extensively studied as a basis for trajectory generation and control of robot manipulators. The focus here is on trajectory generation in the gross-motion phase of space crane operation. Inverse dynamics of the flexible crane body is much more complex and intricate as compared with rigid robot link. To model and solve the space crane's inverse dynamics problem, LATDYN program which employs a three-dimensional finite element formulation for the multibody truss-type structures will be used. The formulation is oriented toward a joint dominated structure which is suitable for the proposed space crane concept. To track a planned trajectory, procedures will be developed to obtain the actuation profile and dynamics envelope which are pertinent to the design and performance requirements of the space crane concept.

  5. Combinatorial pattern discovery approach for the folding trajectory analysis of a beta-hairpin.

    Directory of Open Access Journals (Sweden)

    Laxmi Parida

    2005-06-01

    Full Text Available The study of protein folding mechanisms continues to be one of the most challenging problems in computational biology. Currently, the protein folding mechanism is often characterized by calculating the free energy landscape versus various reaction coordinates, such as the fraction of native contacts, the radius of gyration, RMSD from the native structure, and so on. In this paper, we present a combinatorial pattern discovery approach toward understanding the global state changes during the folding process. This is a first step toward an unsupervised (and perhaps eventually automated approach toward identification of global states. The approach is based on computing biclusters (or patterned clusters-each cluster is a combination of various reaction coordinates, and its signature pattern facilitates the computation of the Z-score for the cluster. For this discovery process, we present an algorithm of time complexity c in RO((N + nm log n, where N is the size of the output patterns and (n x m is the size of the input with n time frames and m reaction coordinates. To date, this is the best time complexity for this problem. We next apply this to a beta-hairpin folding trajectory and demonstrate that this approach extracts crucial information about protein folding intermediate states and mechanism. We make three observations about the approach: (1 The method recovers states previously obtained by visually analyzing free energy surfaces. (2 It also succeeds in extracting meaningful patterns and structures that had been overlooked in previous works, which provides a better understanding of the folding mechanism of the beta-hairpin. These new patterns also interconnect various states in existing free energy surfaces versus different reaction coordinates. (3 The approach does not require calculating the free energy values, yet it offers an analysis comparable to, and sometimes better than, the methods that use free energy landscapes, thus validating the

  6. Combinatorial Pattern Discovery Approach for the Folding Trajectory Analysis of a beta-Hairpin.

    Directory of Open Access Journals (Sweden)

    2005-06-01

    Full Text Available The study of protein folding mechanisms continues to be one of the most challenging problems in computational biology. Currently, the protein folding mechanism is often characterized by calculating the free energy landscape versus various reaction coordinates, such as the fraction of native contacts, the radius of gyration, RMSD from the native structure, and so on. In this paper, we present a combinatorial pattern discovery approach toward understanding the global state changes during the folding process. This is a first step toward an unsupervised (and perhaps eventually automated approach toward identification of global states. The approach is based on computing biclusters (or patterned clusters-each cluster is a combination of various reaction coordinates, and its signature pattern facilitates the computation of the Z-score for the cluster. For this discovery process, we present an algorithm of time complexity cinRO((N + nm log n, where N is the size of the output patterns and (n x m is the size of the input with n time frames and m reaction coordinates. To date, this is the best time complexity for this problem. We next apply this to a beta-hairpin folding trajectory and demonstrate that this approach extracts crucial information about protein folding intermediate states and mechanism. We make three observations about the approach: (1 The method recovers states previously obtained by visually analyzing free energy surfaces. (2 It also succeeds in extracting meaningful patterns and structures that had been overlooked in previous works, which provides a better understanding of the folding mechanism of the beta-hairpin. These new patterns also interconnect various states in existing free energy surfaces versus different reaction coordinates. (3 The approach does not require calculating the free energy values, yet it offers an analysis comparable to, and sometimes better than, the methods that use free energy landscapes, thus validating the

  7. A Modification and Analysis of Lagrangian Trajectory Modeling and Granular Dynamics of Lunar Dust Particles

    Science.gov (United States)

    Long, Jason M.; Lane, John E.; Metzger, Philip T.

    2008-01-01

    A previously developed mathematical model is amended to more accurately incorporate the effects of lift and drag on single dust particles in order to predict their behavior in the wake of high velocity gas flow. The model utilizes output from a CFD or DSMC simulation of exhaust from a rocket nozzle hot gas jet. An extension of the Saffman equation for lift based on the research of McLaughlin (1991) and Mei (1992) is used, while an equation for the Magnus force modeled after the work of Oesterle (1994) and Tsuji et al (1985) is applied. A relationship for drag utilizing a particle shape factor (phi = 0.8) is taken from the work of Haider and Levenspiel (1989) for application to non-spherical particle dynamics. The drag equation is further adjusted to account for rarefaction and compressibility effects in rarefied and high Mach number flows according to the work of Davies (1945) and Loth (2007) respectively. Simulations using a more accurate model with the correction factor (Epsilon = 0.8 in a 20% particle concentration gas flow) given by Richardson and Zaki (1954) and Rowe (1961) show that particles have lower ejection angles than those that were previously calculated. This is more prevalent in smaller particles, which are shown through velocity and trajectory comparison to be more influenced by the flow of the surrounding gas. It is shown that particles are more affected by minor changes to drag forces than larger adjustments to lift forces, demanding a closer analysis of the shape and behavior of lunar dust particles and the composition of the surrounding gas flow.

  8. Analysis of free text in electronic health records for identification of cancer patient trajectories

    DEFF Research Database (Denmark)

    Jensen, Kasper; Soguero-Ruiz, Cristina; Mikalsen, Karl Oyvind

    2017-01-01

    a methodology that allows disease trajectories of the cancer patients to be estimated from free text in electronic health records (EHRs). By using these disease trajectories, we predict 80% of patient events ahead in time. By control of confounders from 8326 quantified events, we identified 557 events......, there has never been a greater need to enforce evidence-led medical decision-making using available health care data. In the present work, we studied a cohort of 7,741 patients, of whom 4,080 were diagnosed with cancer, surgically treated at a University Hospital in the years 2004-2012. We have developed...

  9. Sequence Analysis of How Disability Influenced Life Trajectories in a Past Population from the Nineteenth-Century Sundsvall Region, Sweden

    Directory of Open Access Journals (Sweden)

    Lotta Vikström

    2017-05-01

    Full Text Available Historically, little is known about whether and to what extent disabled people found work and formed families. To fill this gap, this study analyses the life course trajectories of both disabled and non-disabled individuals, between the ages of 15 and 33, from the Sundsvall region in Sweden during the nineteenth century. Having access to micro-data that report disabilities in a population of 8,874 individuals from the parish registers digitised by the Demographic Data Base, Umeå University, we employ sequence analysis on a series of events that are expected to occur in life of young adults: getting a job, marrying and becoming a parent, while also taking into account out-migration and death. Through this method we obtain a holistic picture of the life course of disabled people. Main findings show that their trajectories did not include work or family to the same extent as those of non-disabled people. Secondary findings concerning migration and mortality indicate that the disabled rarely out-migrated from the region, and they suffered from premature deaths. To our knowledge this is the first study to employ sequence analysis on a substantially large number of cases to provide demographic evidence of how disability shaped human trajectories in the past during an extended period of life. Accordingly, we detail our motivation for this method, describe our analytical approach, and discuss the advantages and disadvantages associated with sequence analysis for our case study.

  10. Phylogenetic invariants for group-based models

    CERN Document Server

    Donten-Bury, Maria

    2010-01-01

    In this paper we investigate properties of algebraic varieties representing group-based phylogenetic models. We give the (first) example of a nonnormal general group-based model for an abelian group. Following Kaie Kubjas we also determine some invariants of group-based models showing that the associated varieties do not have to be deformation equivalent. We propose a method of generating many phylogenetic invariants and in particular we show that our approach gives the whole ideal of the claw tree for 3-Kimura model under the assumption of the conjecture of Sturmfels and Sullivant. This, combined with the results of Sturmfels and Sullivant, would enable to determine all phylogenetic invariants for any tree for 3-Kimura model and possibly for other group-based models.

  11. Identification of synoptic precursors to extreme precipitation events in the Swiss Alps by the analysis of backward trajectories

    Science.gov (United States)

    Nguyen, Liliane; Horton, Pascal; Jaboyedoff, Michel

    2015-04-01

    combinations of tools, datasets and methods as possible. For the second part, in order to reduce the number of models to be assessed, we removed those models yielding to similar results. Then, the selected models were used to search simple precursors leading to heavy precipitations. Based on deviations analysis, we preliminary observed that the larger differences between trajectories result mainly from the dataset used rather than the model. Then, we processed 10 days backward trajectories for the Binn station (Wallis, Switzerland), which is a gauging station that often measures big amount of rain. As for the validity domain, we selected all the days between 1961 and 2014 that were characterized by a southerly circulation in autumn. Backward trajectories offer a way to understand some characteristics of air masses inducing heavy precipitation. For example, specific humidity can be retrieved all along the trajectories. Therefore, the origin of moisture contributing to heavy precipitation, and the role of the different weather systems in transporting moisture towards the Alps can be determined with the help of a Lagrangian moisture source diagnostic. According to the first results, moisture sources for heavy precipitation in autumn are mainly located on the western Mediterranean. An identification of simple synoptic precursors is by then attempted throughout analysis made on the resulting trajectories.

  12. A mixture model for the joint analysis of latent developmental trajectories and survival

    NARCIS (Netherlands)

    Klein Entink, R.H.; Fox, J.P.; Hout, A. van den

    2011-01-01

    A general joint modeling framework is proposed that includes a parametric stratified survival component for continuous time survival data, and a mixture multilevel item response component to model latent developmental trajectories given mixed discrete response data. The joint model is illustrated in

  13. Trajectories of childbearing among HIV infected Indian women: A sequence analysis approach

    NARCIS (Netherlands)

    Darak, S.; Mills, M.; Kulkarni, V.; Kulkarni, S.; Hutter, I.; Janssen, F.

    2015-01-01

    Background HIV infection closely relates to and deeply affects the reproductive career of those infected. However, little is known about the reproductive career trajectories, specifically the interaction of the timing of HIV diagnosis with the timing and sequencing of reproductive events among HIV i

  14. Understanding the Gender Gap in School Performance among Low-Income Children: A Developmental Trajectory Analysis

    Science.gov (United States)

    Kingdon, Danielle; Serbin, Lisa A.; Stack, Dale M.

    2017-01-01

    Internationally, girls outperform boys in overall school performance. The gender gap is particularly large among those in at-risk groups, such as children from families at economic disadvantage. This study modeled the academic trajectories of a low-income sample of boys and girls from the Concordia Longitudinal Risk Project across the full course…

  15. Trajectories of Childbearing among HIV Infected Indian Women : A Sequence Analysis Approach

    NARCIS (Netherlands)

    Darak, Shrinivas; Mills, Melinda; Kulkarni, Vinay; Kulkarni, Sanjeevani; Hutter, Inge; Janssen, Fanny

    2015-01-01

    Background HIV infection closely relates to and deeply affects the reproductive career of those infected. However, little is known about the reproductive career trajectories, specifically the interaction of the timing of HIV diagnosis with the timing and sequencing of reproductive events among HIV i

  16. A mixture model for the joint analysis of latent developmental trajectories and survival

    NARCIS (Netherlands)

    Klein Entink, R.H.; Fox, J.P.; Hout, A. van den

    2011-01-01

    A general joint modeling framework is proposed that includes a parametric stratified survival component for continuous time survival data, and a mixture multilevel item response component to model latent developmental trajectories given mixed discrete response data. The joint model is illustrated in

  17. Path Planning, Dynamic Trajectory Generation and Control Analysis for Industrial Manipulators

    OpenAIRE

    2011-01-01

    Many unsolved problems exists in the field of robot control.This text investigates state of the art methods for path finding, trajectory generation and control in order to identify their properties, which problems they are applicable to, and their weaknesses.This is done by applying them to problems with actual real-world relevance.

  18. LONG-DISTANCE GM POLLEN MOVEMENT OF CREEPING BENTGRASS USING MODELED WIND TRAJECTORY ANALYSIS

    Science.gov (United States)

    The importance of understanding the role of atmospheric conditions in pollen dispersal has grown in recent years with increased field-testing of genetically modified (GM) crop plants. An atmospheric model was used to characterize wind trajectories at 10 m and 100 m above GM polle...

  19. Developmental Trajectories of Childhood Obesity and Risk Behaviors in Adolescence

    Science.gov (United States)

    Huang, David Y. C.; Lanza, H. Isabella; Wright-Volel, Kynna; Anglin, M. Douglas

    2013-01-01

    Using group-based trajectory modeling, this study examined 5156 adolescents from the child sample of the 1979 National Longitudinal Survey of Youth to identify developmental trajectories of obesity from ages 6-18 and evaluate associations of such trajectories with risk behaviors and psychosocial health in adolescence. Four distinctive obesity…

  20. Developmental Trajectories of Childhood Obesity and Risk Behaviors in Adolescence

    Science.gov (United States)

    Huang, David Y. C.; Lanza, H. Isabella; Wright-Volel, Kynna; Anglin, M. Douglas

    2013-01-01

    Using group-based trajectory modeling, this study examined 5156 adolescents from the child sample of the 1979 National Longitudinal Survey of Youth to identify developmental trajectories of obesity from ages 6-18 and evaluate associations of such trajectories with risk behaviors and psychosocial health in adolescence. Four distinctive obesity…

  1. Childhood growth trajectories according to combinations of pregestational weight status and maternal smoking during pregnancy: a multilevel analysis.

    Science.gov (United States)

    Suzuki, Kohta; Sato, Miri; Zheng, Wei; Shinohara, Ryoji; Yokomichi, Hiroshi; Yamagata, Zentaro

    2015-01-01

    Pregestational weight status and maternal smoking during pregnancy are significantly associated with fetal and childhood growth. However, few studies have examined associations between childhood growth and combinations of these factors using multilevel analysis. This study aimed to describe differences in childhood growth trajectories according to these combinations, using data from a prospective cohort study in Japan. The study participants were 1,973 women and their singletons, who were born between April 1, 1991 and March 31, 2003. Children were categorized according to whether they were born to normal-weight, nonsmoking mothers (NN); normal-weight, smoking mothers (NS); underweight, nonsmoking mothers (UN); underweight, smoking mothers (US); overweight, nonsmoking mothers (ON); or overweight, smoking mothers (OS). Birth weight and anthropometric data were collected from 1,965 children at birth (99.6%), 1,655 aged 3 (83.9%), 1,527 aged 5 (77.4%), 1,497 aged 7-8 (75.9%), and 1,501 aged 9-10 (76.1%). Multilevel analysis examining both individual and age as different level variables according to sex was used to describe the trajectories of body mass index z scores for statistical analyses. Although children of the OS group were the leanest at birth, their body mass indices had increased rapidly by 3 years of age. Moreover, body mass index was also likely to increase in boys in the NS and ON groups. A different trend was observed in girls. Body mass index decreased from 5 years of age in girls in the US group. There were no remarkable differences in body mass index trajectories between children in the other groups. In conclusion, childhood growth trajectories differed according to combinations of pregestational weight status and maternal smoking during pregnancy. Further, there were sex-related differences in the associations between childhood growth and factor combinations.

  2. Design of cycler trajectories and analysis of solar influences on radioactive decay rates during space missions

    Science.gov (United States)

    Rogers, Blake A.

    This thesis investigates the design of interplanetary missions for the continual habitation of Mars via Earth-Mars cyclers and for the detection of variations in nuclear decay rates due to solar influences. Several cycler concepts have been proposed to provide safe and comfortable quarters for astronauts traveling between the Earth and Mars. However, no literature has appeared to show how these massive vehicles might be placed into their cycler trajectories. Trajectories are designed that use either Vinfinity leveraging or low thrust to establish cycler vehicles in their desired orbits. In the cycler trajectory cases considered, the use of Vinfinity leveraging or low thrust substantially reduces the total propellant needed to achieve the cycler orbit compared to direct orbit insertion. In the case of the classic Aldrin cycler, the propellant savings due to Vinfinity leveraging can be as large as a 24 metric ton reduction for a cycler vehicle with a dry mass of 75 metric tons, and an additional 111 metric ton reduction by instead using low thrust. The two-synodic period cyclers considered benefit less from Vinfinity leveraging, but have a smaller total propellant mass due to their lower approach velocities at Earth and Mars. It turns out that, for low-thrust establishment, the propellant required is approximately the same for each of the cycler trajectories. The Aldrin cycler has been proposed as a transportation system for human missions between Earth and Mars. However, the hyperbolic excess velocity values at the planetary encounters for these orbits are infeasibly large, especially at Mars. In a new version of the Aldrin cycler, low thrust is used in the interplanetary trajectories to reduce the encounter velocities. Reducing the encounter velocities at both planets reduces the propellant needed by the taxis (astronauts use these taxis to transfer between the planetary surfaces and the cycler vehicle) to perform hyperbolic rendezvous. While the propellant

  3. Trajectory design and navigation analysis for Cargo Transfer Vehicle proximity operations

    Science.gov (United States)

    Marsh, S. M.; White, B. D.

    1992-01-01

    The paper documents an investigation of alternative (or off-nominal) final approach trajectories and terminal guidance algorithms for Cargo Transfer Vehicle (CTV) automated rendezvous and proximity operation in the vicinity of Space Station Freedom (SSF). Ten candidate trajectory designs, representing a survey of all approaches that reasonably satisfy the mission constraints, are compared qualitatively and quantitatively. It is shown that several fundamentally different types of approach strategies are feasible in the CTV application and enjoy more favorable passive collision avoidance and plume impingement properties than the nominal. They are, however, generally more costly in propellant. The extent to which an alternative approach is more costly is determined largely by the abort (or specifically the 'hold' or 'wave-off') requirements. These approach techniques are verified in a software simulation using a parametrically defined candidate navigation system, and proximity sensor accuracy requirements are derived.

  4. Trajectory design and navigation analysis for Cargo Transfer Vehicle proximity operations

    Science.gov (United States)

    Marsh, S. M.; White, B. D.

    1992-08-01

    The paper documents an investigation of alternative (or off-nominal) final approach trajectories and terminal guidance algorithms for Cargo Transfer Vehicle (CTV) automated rendezvous and proximity operation in the vicinity of Space Station Freedom (SSF). Ten candidate trajectory designs, representing a survey of all approaches that reasonably satisfy the mission constraints, are compared qualitatively and quantitatively. It is shown that several fundamentally different types of approach strategies are feasible in the CTV application and enjoy more favorable passive collision avoidance and plume impingement properties than the nominal. They are, however, generally more costly in propellant. The extent to which an alternative approach is more costly is determined largely by the abort (or specifically the 'hold' or 'wave-off') requirements. These approach techniques are verified in a software simulation using a parametrically defined candidate navigation system, and proximity sensor accuracy requirements are derived.

  5. Quantum trajectories

    CERN Document Server

    Chattaraj, Pratim Kumar

    2010-01-01

    The application of quantum mechanics to many-particle systems has been an active area of research in recent years as researchers have looked for ways to tackle difficult problems in this area. The quantum trajectory method provides an efficient computational technique for solving both stationary and time-evolving states, encompassing a large area of quantum mechanics. Quantum Trajectories brings the expertise of an international panel of experts who focus on the epistemological significance of quantum mechanics through the quantum theory of motion.Emphasizing a classical interpretation of quan

  6. SU-E-T-144: Effective Analysis of VMAT QA Generated Trajectory Log Files for Medical Accelerator Predictive Maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Able, CM; Baydush, AH; Nguyen, C; Munley, MT [Wake Forest School of Medicine, Department of Radiation Oncology, Winston Salem, NC (United States); Gersh, J [Gibbs Cancer Center and Research Institute, Spartenburg Regional Medical Ce, Spartenburg, SC (United States); Ndlovu, A; Rebo, I [John Theuer Cancer Center, Hackensack University Medical Center, Hackensack, NJ (United States); Booth, J; Perez, M [North Sydney Cancer Center, Royal North Shore Hospital, Sydney, St Leonards (Australia); Sintay, B [Cone Health Cancer Center, Greensboro, NC (United States)

    2014-06-01

    Purpose: To determine the effectiveness of SPC analysis for a model predictive maintenance process that uses accelerator generated parameter and performance data contained in trajectory log files. Methods: Each trajectory file is decoded and a total of 131 axes positions are recorded (collimator jaw position, gantry angle, each MLC, etc.). This raw data is processed and either axis positions are extracted at critical points during the delivery or positional change over time is used to determine axis velocity. The focus of our analysis is the accuracy, reproducibility and fidelity of each axis. A reference positional trace of the gantry and each MLC is used as a motion baseline for cross correlation (CC) analysis. A total of 494 parameters (482 MLC related) were analyzed using Individual and Moving Range (I/MR) charts. The chart limits were calculated using a hybrid technique that included the use of the standard 3σ limits and parameter/system specifications. Synthetic errors/changes were introduced to determine the initial effectiveness of I/MR charts in detecting relevant changes in operating parameters. The magnitude of the synthetic errors/changes was based on: TG-142 and published analysis of VMAT delivery accuracy. Results: All errors introduced were detected. Synthetic positional errors of 2mm for collimator jaw and MLC carriage exceeded the chart limits. Gantry speed and each MLC speed are analyzed at two different points in the delivery. Simulated Gantry speed error (0.2 deg/sec) and MLC speed error (0.1 cm/sec) exceeded the speed chart limits. Gantry position error of 0.2 deg was detected by the CC maximum value charts. The MLC position error of 0.1 cm was detected by the CC maximum value location charts for every MLC. Conclusion: SPC I/MR evaluation of trajectory log file parameters may be effective in providing an early warning of performance degradation or component failure for medical accelerator systems.

  7. Transition Path Times for Nucleic Acid Folding Determined from Energy-Landscape Analysis of Single-Molecule Trajectories

    Science.gov (United States)

    Neupane, Krishna; Ritchie, Dustin B.; Yu, Hao; Foster, Daniel A. N.; Wang, Feng; Woodside, Michael T.

    2012-08-01

    The duration of structural transitions in biopolymers is only a fraction of the time spent searching diffusively over the configurational energy landscape. We found the transition time, τTP, and the diffusion constant, D, for DNA and RNA folding using energy landscapes obtained from single-molecule trajectories under tension in optical traps. DNA hairpins, RNA pseudoknots, and a riboswitch all had τTP˜10μs and D˜10-13-14m2/s, despite widely differing unfolding rates. These results show how energy-landscape analysis can be harnessed to characterize brief but critical events during folding reactions.

  8. Analysis of total least squares in estimating the parameters of a mortar trajectory

    Energy Technology Data Exchange (ETDEWEB)

    Lau, D.L.; Ng, L.C.

    1994-12-01

    Least Squares (LS) is a method of curve fitting used with the assumption that error exists in the observation vector. The method of Total Least Squares (TLS) is more useful in cases where there is error in the data matrix as well as the observation vector. This paper describes work done in comparing the LS and TLS results for parameter estimation of a mortar trajectory based on a time series of angular observations. To improve the results, we investigated several derivations of the LS and TLS methods, and early findings show TLS provided slightly, 10%, improved results over the LS method.

  9. Statistical analysis of piloted simulation of real time trajectory optimization algorithms

    Science.gov (United States)

    Price, D. B.

    1982-01-01

    A simulation of time-optimal intercept algorithms for on-board computation of control commands is described. The effects of three different display modes and two different computation modes on the pilots' ability to intercept a moving target in minimum time were tested. Both computation modes employed singular perturbation theory to help simplify the two-point boundary value problem associated with trajectory optimization. Target intercept time was affected by both the display and computation modes chosen, but the display mode chosen was the only significant influence on the miss distance.

  10. [The trajectory towards alternative medicines: an analysis of health professionals' social representations].

    Science.gov (United States)

    Queiroz, M S

    2000-01-01

    This article focuses on social representations of alternative medicines by a group of professors from the School of Medicine and health professionals from the public health system in the city of Campinas, São Paulo, basically physicians and nurses. The article also emphasizes personal trajectories by which these health professionals opted for a dissident theoretical and practical perspective vis-à-vis the hegemonic positivist scientific medical paradigm. The research methods were mainly ethnographic, from a phenomenological perspective. The article concludes by sustaining (in theoretical terms) the importance of these dissident perspectives for scientific development.

  11. Multiple trajectory analysis of MLS observed stratospheric chemical ozone loss in Arctic winter 1995/96

    Science.gov (United States)

    Lemmen, C.; Riese, R.; Grooss, J.-U.; Mueller, R.

    2003-04-01

    Daily ozone loss rates and total chemical ozone depletion during Arctic winter 1995/96 were evaluated based on ozone measurements by the Microwave Limb Sounder (MLS) instrument onboard the Upper Atmosphere Research Satellite (UARS). Employing the 3-dimensional transport scheme of the Chemical Lagrangian Model of the Stratosphere (CLaMS), trajectories from successive satellite measurements were compared with each other using a variation of the Match technique, such that ozone concentration differences between double sounded (``matched'') air parcels represent chemical ozone loss. The ensemble average of many (typically 30--150) matches yields an average ozone depletion rate for the area covered by the trajectories. Total ozone loss from late December to early March was 1.4 ppmv at the 475 K isentropic level within the vortex core (PV > 45 PVU at 475 K). Ozone loss decreased towards the edge of the vortex, no significant ozone loss could be observed in the outer vortex edge (between ≈ 27 and ≈ 35 PVU). Daily ozone loss was found to average 10 ppbv/day throughout January and throughout the extended vortex area. For the month of February daily ozone loss rates were highly variable and peaked at 40 ppbv/day in the vortex (≈ 35 PVU). In this study, no chemical ozone loss could be observed in the outer vortex edge region during February, which suggests that the dynamically defined vortex boundary separated two different chemical regimes during February, but not in January.

  12. Gradient trajectory analysis of the scalar superlayer in a jet flow

    Science.gov (United States)

    Gampert, Markus; Schaefer, Philip; Peters, Norbert

    2012-11-01

    Based on planar high-speed Rayleigh scattering measurements of the mass fraction of propane discharging from a turbulent round jet into co-flowing carbon dioxide at nozzle based Reynolds numbers Re0 = 3 , 000 - 8 , 600 , we investigate the scalar superlayer. The latter is located between the fully turbulent part of the jet and the outer flow and has the so called turbulent/non-turbulent interface embedded within it. It is termed in analogy to the laminar superlayer introduced by Corrsin and Kistler (NACA Report 1244, 1955). Using scalar gradient trajectories, we partition the turbulent scalar field into the afore mentioned three regions according to an approach developed by Mellado et al. (J. Fluid Mech. 626:333-365, 2009) based on which we in a next step investigate conditioned zonal statistics of the scalar pdf as well as the scalar difference along the trajectory and its mean scalar value. Finally, we relate our results for the scalar superlayer on the one hand to the findings made in other experimental and numerical studies of the turbulent/non-turbulent interface and discuss them on the other hand in the context of the flamelet approach in turbulent non-premixed combustion. This work was funded by the Cluster of Excellence ``Tailor-Made Fuels from Biomass,'' which is funded by the Excellence Initiative of the German federal state governments to promote science and research at German universities.

  13. Estimating Jupiter’s Gravity Field Using Juno Measurements, Trajectory Estimation Analysis, and a Flow Model Optimization

    Science.gov (United States)

    Galanti, Eli; Durante, Daniele; Finocchiaro, Stefano; Iess, Luciano; Kaspi, Yohai

    2017-07-01

    The upcoming Juno spacecraft measurements have the potential of improving our knowledge of Jupiter’s gravity field. The analysis of the Juno Doppler data will provide a very accurate reconstruction of spatial gravity variations, but these measurements will be very accurate only over a limited latitudinal range. In order to deduce the full gravity field of Jupiter, additional information needs to be incorporated into the analysis, especially regarding the Jovian flow structure and its depth, which can influence the measured gravity field. In this study we propose a new iterative method for the estimation of the Jupiter gravity field, using a simulated Juno trajectory, a trajectory estimation model, and an adjoint-based inverse model for the flow dynamics. We test this method both for zonal harmonics only and with a full gravity field including tesseral harmonics. The results show that this method can fit some of the gravitational harmonics better to the “measured” harmonics, mainly because of the added information from the dynamical model, which includes the flow structure. Thus, it is suggested that the method presented here has the potential of improving the accuracy of the expected gravity harmonics estimated from the Juno and Cassini radio science experiments.

  14. Differentially Private Trajectory Data Publication

    CERN Document Server

    Chen, Rui; Desai, Bipin C

    2011-01-01

    With the increasing prevalence of location-aware devices, trajectory data has been generated and collected in various application domains. Trajectory data carries rich information that is useful for many data analysis tasks. Yet, improper publishing and use of trajectory data could jeopardize individual privacy. However, it has been shown that existing privacy-preserving trajectory data publishing methods derived from partition-based privacy models, for example k-anonymity, are unable to provide sufficient privacy protection. In this paper, motivated by the data publishing scenario at the Societe de transport de Montreal (STM), the public transit agency in Montreal area, we study the problem of publishing trajectory data under the rigorous differential privacy model. We propose an efficient data-dependent yet differentially private sanitization algorithm, which is applicable to different types of trajectory data. The efficiency of our approach comes from adaptively narrowing down the output domain by building...

  15. Trajectory Generation and Stability Analysis for Reconfigurable Klann Mechanism Based Walking Robot

    Directory of Open Access Journals (Sweden)

    Jaichandar Kulandaidaasan Sheba

    2016-06-01

    Full Text Available Reconfigurable legged robots based on one degree of freedom are highly desired because they are effective on rough and irregular terrains and they provide mobility in such terrain with simple control schemes. It is necessary that reconfigurable legged robots should maintain stability during rest and motion, with a minimum number of legs while maintaining their full range of walking patterns resulting from different gait configuration. In this paper we present a method to generate input trajectory for reconfigurable quadruped robots based on Klann mechanism to properly synchronize movement. Six useful gait cycles based on this reconfigurable Klann mechanism for quadruped robots has been clearly shown here. The platform stability for these six useful gait cycles are validated through simulated results which clearly shows the capabilities of reconfigurable design.

  16. Analysis of the trajectory of a sphere moving through a geometric constriction

    CERN Document Server

    Risbud, Sumedh R; Frechette, Joelle; Drazer, German

    2013-01-01

    We present a numerical study of the effect of inertia on suspended particles moving through a geometric constriction to understand the behavior of particles in analogous microfluidic settings, such as pinched flow fractionation devices. The particles are driven by a constant force in a quiescent fluid, and the constriction (the pinching gap) corresponds to the space between a plane wall and a second, fixed sphere of the same size (the obstacle). The results show that, due to the effect of inertia and geometric constriction (individual or combined) the particles attain smaller surface-to-surface separations from the obstacle. We then relate the minimum surface-to-surface separation to the effect that the short-range repulsive non-hydrodynamic interactions (such as solid-solid contact due to surface roughness, electrostatic double layer repulsion, etc.) would have on the particle trajectories. In particular, using a simple hard-core repulsive potential model for such interactions, we infer that the particles wo...

  17. Life trajectory as a process of identity formation: The potential of narrative analysis

    Directory of Open Access Journals (Sweden)

    E S Pavlenko

    2016-12-01

    Full Text Available In the contemporary highly differentiated society, culture and the symbolic processes within it are becoming increasingly important. The strengthening of symbolic mechanisms effect is obvious in many social phenomena, in particular in the transition to adulthood. The process of growing up and becoming an adult, as well as the image of adulthood itself, are transforming, which demands that social researchers seek for new conceptual resources for understanding the new nuances of the transition to adulthood in the contemporary society. Cultural psychology has developed the categorical apparatus that is quite sensitive to the symbolic processes within the personality development in the course of transition to adulthood. Cultural psychologists believe that every life trajectory as a process of personal identity development should be studied as determined by narratives and narration. However, despite the claim and intention to develop an approach that would take into account social factors (such as community influence, role of collective practices, and dominant social representations of adulthood in fact, cultural psychologists prefer to conceptualize the nowadays social reality as reduced to the political and ideological discourses. Thus, cultural sociology can provide theoretical means for analyzing narratives of transition to adulthood as mainly collective processes, therefore discovering the symbolic mechanisms of transition to adulthood through life stories. With cultural sociology as a conceptual background for the development of appropriate tools for youth studies in sociology, there is a quite new research agenda, which consists of discovering genres and categorical repertoire of becoming an adult in narratives of the younger people. This can lead to the sociological reconstruction of categories that create the meaningful space of coming of age, from which young people draw resources to create meaningful narratives about their life

  18. Optimal trajectories for an aerospace plane. Part 1: Formulation, results, and analysis

    Science.gov (United States)

    Miele, Angelo; Lee, W. Y.; Wu, G. D.

    1990-01-01

    The optimization of the trajectories of an aerospace plane is discussed. This is a hypervelocity vehicle capable of achieving orbital speed, while taking off horizontally. The vehicle is propelled by four types of engines: turbojet engines for flight at subsonic speeds/low supersonic speeds; ramjet engines for flight at moderate supersonic speeds/low hypersonic speeds; scramjet engines for flight at hypersonic speeds; and rocket engines for flight at near-orbital speeds. A single-stage-to-orbit (SSTO) configuration is considered, and the transition from low supersonic speeds to orbital speeds is studied under the following assumptions: the turbojet portion of the trajectory has been completed; the aerospace plane is controlled via the angle of attack and the power setting; the aerodynamic model is the generic hypersonic aerodynamics model example (GHAME). Concerning the engine model, three options are considered: (EM1), a ramjet/scramjet combination in which the scramjet specific impulse tends to a nearly-constant value at large Mach numbers; (EM2), a ramjet/scramjet combination in which the scramjet specific impulse decreases monotonically at large Mach numbers; and (EM3), a ramjet/scramjet/rocket combination in which, owing to stagnation temperature limitations, the scramjet operates only at M approx. less than 15; at higher Mach numbers, the scramjet is shut off and the aerospace plane is driven only by the rocket engines. Under the above assumptions, four optimization problems are solved using the sequential gradient-restoration algorithm for optimal control problems: (P1) minimization of the weight of fuel consumed; (P2) minimization of the peak dynamic pressure; (P3) minimization of the peak heating rate; and (P4) minimization of the peak tangential acceleration.

  19. A novel theoretical framework for the dynamic stability analysis, movement control, and trajectory generation in a multisegment biomechanical model.

    Science.gov (United States)

    Iqbal, Kamran; Roy, Anindo

    2009-01-01

    We consider a simplified characterization of the postural control system that embraces two broad components: one representing the musculoskeletal dynamics in the sagittal plane and the other representing proprioceptive feedback and the central nervous system (CNS). Specifically, a planar four-segment neuromusculoskeletal model consisting of the ankle, knee, and hip degrees-of-freedom (DOFs) is described in this paper. The model includes important physiological constructs such as Hill-type muscle model, active and passive muscle stiffnesses, force feedback from the Golgi tendon organ, muscle length and rate feedback from the muscle spindle, and transmission latencies in the neural pathways. A proportional-integral-derivative (PID) controller for each individual DOF is assumed to represent the CNS analog in the modeling paradigm. Our main hypothesis states that all stabilizing PID controllers for such multisegment biomechanical models can be parametrized and analytically synthesized. Our analytical and simulation results show that the proposed representation adequately shapes a postural control that (a) possesses good disturbance rejection and trajectory tracking, (b) is robust against feedback latencies and torque perturbations, and (c) is flexible to embrace changes in the musculoskeletal parameters. We additionally present detailed sensitivity analysis to show that control under conditions of limited or no proprioceptive feedback results in (a) significant reduction in the stability margins, (b) substantial decrease in the available stabilizing parameter set, and (c) oscillatory movement trajectories. Overall, these results suggest that anatomical arrangement, active muscle stiffness, force feedback, and physiological latencies play a major role in shaping motor control processes in humans.

  20. PROCESSING AND ANALYSIS OF Fligh experiment DATA FOR DETERMINING THE CHARACTERISTICS OF THE MOTION OF A ROUND PARACHUTE on a spiral trajectory AT HIGH ALTITUDES

    Directory of Open Access Journals (Sweden)

    S. V. Zhurin

    2015-01-01

    Full Text Available The article is addressed to the analysis of the trajectory parameters and videos obtained during the flight experiment at the launch of meteo-rocket MMP-06 with the purpose to determine major parameters of motion of a round parachute at subsonic speeds in the range of altitudes from 0 to 40 km. The data analysis showed that the trajectory of the parachute represents spiral "stretched" by the wind in the horizontal direction and disturbed by random factors of a non-stationary flow around the parachute. The main parameters of the trajectory are obtained according to the experimental data. Only qualitative analysis of spiral motion paths for round parachutes may be found in the publications on parachute subjects. This article presents the quantitative characteristics of this process.

  1. Using Lidar, in-situ measurements and Trajectory Analysis to observe air pollution in Beijing, 2014

    Directory of Open Access Journals (Sweden)

    Chen Zhenyi

    2016-01-01

    Full Text Available We present combined Mie lidar, ozone lidar and wide-range particle spectrometer observations that were carried out in Beijing, north China during two periods—one haze period before the Asia-Pacific Economic Cooperation (APEC meeting and one moderate pollution period during the meeting in 2014. High extinction coefficient, moderate ozone concentration and variable particle number concentration were obtained throughout the first haze observation period. The mean extinction coefficients in the two pollution periods were 0.52 km-1 and 0.23 km-1, respectively, at 532 nm. The ozone concentration during the first haze phase was more various with higher average value of 49 ppb compared to that in the second pollution observations (32 ppb. The comparison of aerosols and ozone in different heights indicate different pollution sources and complicated ozone process of generation and disappearance. The four-day back trajectories from a HYSPLIT model indicate that the air masses in the lower boundary layer were advected from the densely populated south regions of China and the long pollution transportation passing through northern China.

  2. Using Lidar, in-situ measurements and Trajectory Analysis to observe air pollution in Beijing, 2014

    Science.gov (United States)

    Chen, Zhenyi; Liu, Wenqing; Liu, Jianguo; Zhang, Tianshu; Dong, Yunsheng

    2016-06-01

    We present combined Mie lidar, ozone lidar and wide-range particle spectrometer observations that were carried out in Beijing, north China during two periods—one haze period before the Asia-Pacific Economic Cooperation (APEC) meeting and one moderate pollution period during the meeting in 2014. High extinction coefficient, moderate ozone concentration and variable particle number concentration were obtained throughout the first haze observation period. The mean extinction coefficients in the two pollution periods were 0.52 km-1 and 0.23 km-1, respectively, at 532 nm. The ozone concentration during the first haze phase was more various with higher average value of 49 ppb compared to that in the second pollution observations (32 ppb). The comparison of aerosols and ozone in different heights indicate different pollution sources and complicated ozone process of generation and disappearance. The four-day back trajectories from a HYSPLIT model indicate that the air masses in the lower boundary layer were advected from the densely populated south regions of China and the long pollution transportation passing through northern China.

  3. Developmental trajectories of romantic stages and associations with problem behaviours during adolescence.

    Science.gov (United States)

    Connolly, Jennifer; Nguyen, Hien N T; Pepler, Debra; Craig, Wendy; Jiang, Depeng

    2013-12-01

    Normative romantic development is theorized to progress through a series of stages: affiliative activities, group-based dating, and romantic relationships. The objectives of this research were threefold: empirically examine this progression of romantic stages during adolescence, determine normative and atypical trajectories, and examine links with internalizing and externalizing symptoms. An eight-wave longitudinal study was conducted with 698 adolescents (53.6% female; M(age) = 11.8 years at start of study). A group-based trajectory approach was employed to identify prototypical trajectories of romantic development and a model with three distinct romantic trajectories (i.e., On-time, Early Starters and Late Bloomers) was identified. Both timing and sequencing of romantic activity differed among trajectory groups. Analysis of Variance (ANOVAs) identified associations between Early Starters and externalizing behaviours in early, middle and later adolescence. The findings support progression through theorized stages of romantic activity and highlight the problems that are linked to early-starting and non-sequenced romantic development.

  4. PM over summertime India: Sources and trends investigated using long term measurements and multi-receptor site back trajectory analysis

    Science.gov (United States)

    Kumar, Vinod; Sarkar, Chinmoy; Sachan, Himanshu; Kumar, Devender; Sinha, Baerbel

    2013-04-01

    We apply multi-receptor site residence-time weighted concentration back trajectory analysis to a ten year data set (1991-2003) of PM10 and TSP measurement data from four Indian megacities Delhi, Mumbai, Kolkata and Chennai. The dataset was sourced from the published and peer reviewed work of Gupta and Kumar (2006). Sources and trends of PM10 and TSP during the pre-monsoon season (March-June) were investigated. Residence-time weighted concentration maps were derived using 72 hour HYSPLIT back trajectory ensemble calculations. Trajectory runs were started 100 m AGL and the observed PM monthly averages were attributed to all trajectory runs in a month and each trajectory of the ensemble runs with equal probability. For investigating trends the dataset was further subdivided into two groups of four year durations each (1992-1995 and 2000-2003). We found a linear correlation with a slope of 1.0 (R2=0.9) between estimated seasonal average TSP (2000-2003) using our approach and the measured seasonal averages (2006-2007) for Kanpur, Ahmedabad, Pune and Bangalore. A linear fit between predicted and measured PM10 concentration for 19 sites with PM10 observations of at least one seasonal average between 1999-2009 shows a slope of 1.4 (R2=0.4). For the observation period 2000-2003, the Thar Desert and Taklimakan Desert emerged as largest sources for both PM10 (>180 μg/m3 and >200 μg/m3 respectively) and TSP (>650 μg/m3 and >725 μg/m3 respectively). In-situ observation at Bikaner (central Thar Desert) and in Jhunjhunu (semi-arid site at the border of the Thar Desert) indicate that both TSP and PM10 inside the desert source region are underpredicted by a factor of 10 compared to in-situ observations while for the semi arid area bordering the desert PM10 and TSP are underpredicted by a factor of 5 and 3 respectively. This indicates that strong sources are underpredicted by a receptor site centred approach. The entire North-Western Indo-Gangetic Basin (NW-IGB), where crop

  5. Analysis of the attention network to the cervical cancer from the trajectory of users in the Federal District-BR

    Directory of Open Access Journals (Sweden)

    Jeíza Andrade Santana

    2012-04-01

    Full Text Available This study deals with the attention network to the cervical cancer (CC in the Federal District (DF from the trajectory of users of these services. Objectives: to delineate the pathway of care for women from the onset of symptoms until the completion of treatment; identify the potential and limits of the attention network to the CC in the DF. Methodology: ten qualitative and quantitative case studies were held from individual narratives. Data was collected through interviews and analysis of medical records, in 2010. Results: women have easy access to the basic health network, for consultation and colpo-cytological, but they live with the diversity of medical conducts, delayed test results, barriers in the access to the specialty consultations and examinations that support a diagnosis, leading them to have recourse to the private network. Conclusions: there is disconnection between the attention points, jeopardizing the quality and continuity of care for women with CC.

  6. Aircraft Conflict Analysis and Real-Time Conflict Probing Using Probabilistic Trajectory Modeling

    Science.gov (United States)

    Yang, Lee C.; Kuchar, James K.

    2000-01-01

    Methods for maintaining separation between aircraft in the current airspace system have been built from a foundation of structured routes and evolved procedures. However, as the airspace becomes more congested and the chance of failures or operational error become more problematic, automated conflict alerting systems have been proposed to help provide decision support and to serve as traffic monitoring aids. The problem of conflict detection and resolution has been tackled from a number of different ways, but in this thesis, it is recast as a problem of prediction in the presence of uncertainties. Much of the focus is concentrated on the errors and uncertainties from the working trajectory model used to estimate future aircraft positions. The more accurate the prediction, the more likely an ideal (no false alarms, no missed detections) alerting system can be designed. Additional insights into the problem were brought forth by a review of current operational and developmental approaches found in the literature. An iterative, trial and error approach to threshold design was identified. When examined from a probabilistic perspective, the threshold parameters were found to be a surrogate to probabilistic performance measures. To overcome the limitations in the current iterative design method, a new direct approach is presented where the performance measures are directly computed and used to perform the alerting decisions. The methodology is shown to handle complex encounter situations (3-D, multi-aircraft, multi-intent, with uncertainties) with relative ease. Utilizing a Monte Carlo approach, a method was devised to perform the probabilistic computations in near realtime. Not only does this greatly increase the method's potential as an analytical tool, but it also opens up the possibility for use as a real-time conflict alerting probe. A prototype alerting logic was developed and has been utilized in several NASA Ames Research Center experimental studies.

  7. Is infant body mass index associated with adulthood body composition trajectories? An exploratory analysis.

    Science.gov (United States)

    Johnson, W; Choh, A C; Lee, M; Towne, B; Czerwinski, S A; Demerath, E W

    2017-02-01

    Infant body mass index (BMI) is increasingly used as a marker of obesity risk based on its association with young-adulthood BMI. The aim of this study is to test the association of infant BMI with young-adulthood fat mass and fat-free mass, and how this association changes during advancing adulthood. Body mass index Z-score at age 9 months was measured in 350 White, non-Hispanic Fels Longitudinal Study participants. This exposure was entered into multilevel models to test its association with trajectories describing 2665 BMI observations and 1388 observations of fat mass index (FMI, kg m(-2) ) and fat-free mass index (FFMI, kg m(-2) ) between ages 20 and 60 years. Partitioning young-adulthood BMI into its fat and fat-free components, infant BMI Z-score was associated with FFMI (β = 0.745; 95% confidence interval = 0.367 to 1.124) but not FMI (0.528; -0.055 to 1.110) at age 20 years. Greater infant BMI Z-score was associated with slower age-related increases in all outcomes, such that (looking at 10-year intervals) only FFMI at age 30 years was related to infant BMI Z-score (0.338; 0.119, 0.557). Focus on infant BMI reduction for adulthood obesity prevention warrants caution as high infant BMI values are associated with greater lean mass, which is protective against ageing changes. © 2016 World Obesity Federation.

  8. Trajectories of dental anxiety in a birth cohort

    Science.gov (United States)

    Thomson, W. M.; Broadbent, J. M.; Locker, D.; Poulton, R.

    2010-01-01

    Objective To examine predictors of dental anxiety trajectories in a longitudinal study of New Zealanders. Methods Prospective study of a complete birth cohort born in 1972/73 in Dunedin, New Zealand, with dental anxiety scale (DAS) scores and dental utilization determined at ages 15, 18, 26 and 32 years. Personality traits were assessed at a superfactor and (more fine-grained) subscale level via the Multidimensional Personality Questionnaire at age 18 years. Group-based trajectory analysis was used to identify dental anxiety trajectories. Results DAS scores from at least three assessments were available for 828 participants. Six dental anxiety trajectories were observed: stable nonanxious low (39.6%); stable nonanxious medium (37.9%); recovery (1.6%); adult-onset anxious (7.7%); stable anxious (7.2%) and adolescent-onset anxious (5.9%). Multivariate analysis showed that males and those with higher DMFS at age 15 years were more likely to be in the stable nonanxious low trajectory group. Membership of the stable nonanxious medium group was predicted by the dental caries experience at age 15 years. Participants who had lost one or more teeth between ages 26 and 32 years had almost twice the relative risk for membership of the adult-onset anxious group. Personality traits predicted group membership. Specifically, high scorers (via median split) on the ‘stress reaction’ subscale had over twice the risk of being in the stable anxious group; low scorers on the traditionalism subscale were more likely to be members of the recovery trajectory group; and high scorers on the ‘social closeness’ subscale had half the risk of being in the stable anxious group. Dental caries experience at age 5 years was also a predictor for the stable anxious group. Membership of the late-adolescent-onset anxious group was predicted by higher dental caries experience by age 15 years, but none of the other predictors was significant. Conclusion Six discrete trajectories of dental anxiety

  9. Seismic analysis of clinoform depositional sequences and shelf-margin trajectories in Lower Cretaceous (Albian) strata, Alaska North Slope

    Science.gov (United States)

    Houseknecht, D.W.; Bird, K.J.; Schenk, C.J.

    2009-01-01

    Lower Cretaceous strata beneath the Alaska North Slope include clinoform depositional sequences that filled the western Colville foreland basin and overstepped the Beaufort rift shoulder. Analysis of Albian clinoform sequences with two-dimensional (2D) seismic data resulted in the recognition of seismic facies inferred to represent lowstand, transgressive and highstand systems tracts. These are stacked to produce shelf-margin trajectories that appear in low-resolution seismic data to alternate between aggradational and progradational. Higher-resolution seismic data reveal shelf-margin trajectories that are more complex, particularly in net-aggradational areas, where three patterns commonly are observed: (1) a negative (downward) step across the sequence boundary followed by mostly aggradation in the lowstand systems tract (LST), (2) a positive (upward) step across the sequence boundary followed by mostly progradation in the LST and (3) an upward backstep across a mass-failure d??collement. These different shelf-margin trajectories are interpreted as (1) fall of relative sea level below the shelf edge, (2) fall of relative sea level to above the shelf edge and (3) mass-failure removal of shelf-margin sediment. Lowstand shelf margins mapped using these criteria are oriented north-south in the foreland basin, indicating longitudinal filling from west to east. The shelf margins turn westward in the north, where the clinoform depositional system overstepped the rift shoulder, and turn eastward in the south, suggesting progradation of depositional systems from the ancestral Brooks Range into the foredeep. Lowstand shelf-margin orientations are consistently perpendicular to clinoform-foreset-dip directions. Although the Albian clinoform sequences of the Alaska North Slope are generally similar in stratal geometry to clinoform sequences elsewhere, they are significantly thicker. Clinoform-sequence thickness ranges from 600-1000 m in the north to 1700-2000 m in the south

  10. Galileo's Trajectory with Mild Resistance

    Science.gov (United States)

    Groetsch, C. W.

    2012-01-01

    An aspect of Galileo's classical trajectory that persists in a simple resistance model is noted. The resistive model provides a case study for the classroom analysis of limiting behaviour of an implicitly defined function. (Contains 1 note.)

  11. Trajectories of Sexual Risk from Middle Adolescence to Early Adulthood

    Science.gov (United States)

    Moilanen, Kristin L.; Crockett, Lisa J.; Raffaelli, Marcela; Jones, Bobby L.

    2010-01-01

    Developmental trajectories of risky sexual behavior were identified in a multiethnic sample of 1,121 youth drawn from the Children of the National Longitudinal Survey of Youth data set (NLSY79). Group-based trajectory modeling of a composite index of sexual risk taking revealed four sexual risk groups from ages 16 to 22: low risk, decreasing risk,…

  12. Cluster Analysis as a Method of Recovering Types of Intraindividual Growth Trajectories: A Monte Carlo Study.

    Science.gov (United States)

    Dumenci, Levent; Windle, Michael

    2001-01-01

    Used Monte Carlo methods to evaluate the adequacy of cluster analysis to recover group membership based on simulated latent growth curve (LCG) models. Cluster analysis failed to recover growth subtypes adequately when the difference between growth curves was shape only. Discusses circumstances under which it was more successful. (SLD)

  13. Radiation Analysis for Two Trajectory Points of the Fire II Entry

    Directory of Open Access Journals (Sweden)

    Romain Savajano

    2012-01-01

    (QSS and Boltzmann have been compared, and the influence of catalytic wall condition was taken into account. An analysis on the spectral range and on the spectral resolution has also been carried out.

  14. Chemical characteristics of trace metals in PM10 and their concentrated weighted trajectory analysis at Central Delhi, India.

    Science.gov (United States)

    Chandra, Subhash; Kulshrestha, Monika J; Singh, Ruchi; Singh, Nahar

    2017-05-01

    Trace metals associated with PM10 aerosols and their variation during day and nighttime as well as during different seasons have been studied for the year 2012. PCA analysis suggested 5 PCs, which accounted for 86.8% cumulative variance. PC1 accounted for 30% with a significant loading of metals of anthropogenic origin, while PC2 showed 28% variance with the loading of metals of crustal origin. These trace metals showed seasonal distinct day and night time characteristics. The concentrations of Cu, Pb, and Cd were found to be higher during nighttime in all the seasons. Only Fe was observed with significantly higher mean concentrations during daytime of all seasons except monsoon. The highest mean values of Cu, Cd, Zn, and Pb during post-monsoon might be attributed to winds advection over the regions of waste/biomass burning and industrial activities in Punjab and Haryana regions. Furthermore, concentration weighted trajectory analysis suggested that metals of crustal origin were contributed by long-range transport while metals of anthropogenic and industrial activities were contributed by regional/local source regions. Copyright © 2016. Published by Elsevier B.V.

  15. Classification of Aerosol over Central Europe by Cluster Analysis of Aerosol Columnar Optical Properties and Backward Trajectory Statistics

    Science.gov (United States)

    Szkop, Artur; Pietruczuk, Aleksander; Posyniak, Michał

    2016-12-01

    A cluster analysis is applied to the Aerosol Robotic Network (AERONET) data obtained at Belsk, Poland, as well as three nearby Central European stations (Leipzig, Minsk and Moldova) for estimation of atmospheric aerosol types. Absorption Ångstrom exponent (AAE), aerosol optical thickness (AOT) and extinction Ångstrom exponent (EAE) parameters are used. Clustering in both 2D (AOT, EAE) and 3D (AOT, EAE, AAE) is investigated. A method of air mass backward trajectory analysis is then proposed, with the receptor site at Belsk, to determine possible source regions for each cluster. Four dominant aerosol source regions are identified. The biomass burning aerosol source is localized in the vicinity of Belarusian-Ukrainian border. Slovakia and northern Hungary are found to be the source of urban/industrial pollutants. Western Poland and eastern Germany are the main sources of polluted continental aerosols. The most differentiated source region of Scandinavia, Baltic Sea and Northern Atlantic, associated with lowest values of AOT, corresponds to clean continental and possibly maritime type aerosols.

  16. The Neighbourhood Built Environment and Trajectories of Depression Symptom Episodes in Adults: A Latent Class Growth Analysis.

    Directory of Open Access Journals (Sweden)

    Genevieve Gariepy

    Full Text Available To investigate the effect of the neighbourhood built environment on trajectories of depression symptom episodes in adults from the general Canadian population.We used 10 years of data collection (2000/01-2010/11 from the Canadian National Population Health Study (n = 7114. Episodes of depression symptoms were identified using the Composite International Diagnostic Interview Short-Form. We assessed the presence of local parks, healthy food stores, fast food restaurants, health services and cultural services using geospatial data. We used latent class growth modelling to identify different trajectories of depression symptom episodes in the sample and tested for the effect of neighbourhood variables on the trajectories over time.We uncovered three distinct trajectories of depression symptom episodes: low prevalence (76.2% of the sample, moderate prevalence (19.2% and high prevalence of depression symptom episodes (2.8%. The presence of any neighbourhood service (healthy food store, fast-food restaurant, health service, except for cultural service was significantly associated with a lower probability of a depression symptom episode for those following a trajectory of low prevalence of depression symptom episodes. The presence of a local park was also a significant protective factor in trajectory groups with both low and moderate prevalence of depression symptom episodes. Neighbourhood characteristics did not significantly affect the trajectory of high prevalence of depression symptom episodes.For individuals following a trajectory of low and moderate prevalence of depression symptom episodes, the neighbourhood built environment was associated with a shift in the trajectory of depression symptom episodes. Future intervention studies are recommended to make policy recommendations.

  17. Student Trajectories in Physics: The Need for Analysis through a Socio-Cultural Lens

    Science.gov (United States)

    Zapata, Mara

    2010-01-01

    An analysis of student connections through time and space relative to the core discipline of physics is attempted, as viewed through the lens of actor-network-theory, by Antonia Candela. Using lenses of cultural realities, networks, and perceived power in the discourse of one specific university in the capital city of Mexico and one undergraduate…

  18. Comparison study of sub-trajectory clustering in data mining

    Science.gov (United States)

    Yang, Guodong; Huang, Zhitao; Wang, Xiang

    2017-06-01

    Trajectory clustering is an important method to achieve moving object data mining, multi-sensor information fusion and trajectory knowledge discovery. Sub-trajectory clustering is an important method to extract useful information from a large number of trajectory data in trajectory analysis. In this paper, comparative experiments are made on the time consumption, similarity measure and clustering performance based on the existing sub-trajectory clustering methods. Based on the comparisons, the advantages and disadvantages of different methods are presented and an improved method is proposed for dealing with trajectories with low positioning accuracy and correlating tracklets from asynchronous sensors. Besides, a general framework of trajectory data mining is discussed.

  19. A Topical Trajectory on Survival: an Analysis of Link-Making in a Sequence of Lessons on Evolution

    Science.gov (United States)

    Rocksén, Miranda; Olander, Clas

    2017-04-01

    This study explores the concept of link-making in relation to communicative strategies applied in the teaching and studying of biological evolution. The analysis focused on video recordings of 11 lessons on biological evolution conducted in a Swedish 9th grade class of students aged 15 years. It reveals how the teacher and students connected classroom conversations, the frequency of references to conversations in whole-class settings, and the development of a theme focusing on species survival and extinction. Detailed examples from the data illustrate how this theme developed from its initiation during the first lesson, through discussion and clarification, to its wrapping up during the last lesson. They further illustrate how students made sense of what the teacher said and wrote, and how the teacher postponed issues, explained and developed topics, provided opportunities for link-making, organised the class, motivated students, and checked their understanding. The study's methodological approach offers a way of including several time dimensions within research. Based on our findings, we conclude that the excerpts examined here did succeed in building `islands of coherence' in the co-construction of curricular content. Moreover, the topical trajectory in relation to species survival provided opportunities for constructing a `scientific story' in the classroom.

  20. A Topical Trajectory on Survival: an Analysis of Link-Making in a Sequence of Lessons on Evolution

    Science.gov (United States)

    Rocksén, Miranda; Olander, Clas

    2016-04-01

    This study explores the concept of link-making in relation to communicative strategies applied in the teaching and studying of biological evolution. The analysis focused on video recordings of 11 lessons on biological evolution conducted in a Swedish 9th grade class of students aged 15 years. It reveals how the teacher and students connected classroom conversations, the frequency of references to conversations in whole-class settings, and the development of a theme focusing on species survival and extinction. Detailed examples from the data illustrate how this theme developed from its initiation during the first lesson, through discussion and clarification, to its wrapping up during the last lesson. They further illustrate how students made sense of what the teacher said and wrote, and how the teacher postponed issues, explained and developed topics, provided opportunities for link-making, organised the class, motivated students, and checked their understanding. The study's methodological approach offers a way of including several time dimensions within research. Based on our findings, we conclude that the excerpts examined here did succeed in building `islands of coherence' in the co-construction of curricular content. Moreover, the topical trajectory in relation to species survival provided opportunities for constructing a `scientific story' in the classroom.

  1. Preliminary Design and Characteristic Analysis of Moon-to-Earth Transfer Trajectories%月地转移轨道快速设计与特性分析

    Institute of Scientific and Technical Information of China (English)

    张磊; 于登云; 张熇

    2011-01-01

    With the constraints of atmosphere reentry interface parameters and the landingpoint location, a method was proposed for the preliminary design of the moon-to-earth trajectory with direct atmosphere reentry. The method included two stages of iteration loops. The inner loop made moon-center orbit and earth-center orbit continuous at the boundary of the moon influence sphere. To solve the earth-center orbit parameters meeting the reentry angle constrain, a method combined Lambert problem and Newton-Raphson method was adopted. The outer loop made the moon-to-earth trajectory meet the landing-point location constrain by adjusting the launch time.The analysis shows that four types of moon-to-earth trajectories meet atmosphere reentry interface parameters. The four trajectories are descent-descent trajectory, descent-ascent trjectory, ascentdescent trajectory and ascent-ascent trajectory. Then the characteristics of the transfer trajectories were analyzed, such as the perigee geocentric distance, the transfer orbit insertion point distribution, the reentry point distribution. Simulation results indicate that the preliminary design method is effective.%对采用直接大气再入方式的月地转移轨道,考虑大气再入界面参数和地面落点位置约束,提出了一种基于双二体模型的快速设计方法.该方法分为内外两层迭代循环,内层循环使月心段轨道和地心段轨道在月球影响球边界处连续,并采用Lambert问题与Newton-Raphson法相集合的方法求解满足再入角约束的地心段轨道参数;外层循环通过调整地心段轨道倾角和轨道置入时间使月地转移轨道满足地面落点位置约束.分析表明,存在四种类型的月地转移轨道满足大气再入界面约束,分别为降-降型、降-升型、升-降型和升-升型.在此基础上,对四种类型月地转移轨道的近地点地心距、置入分布点、再入点分布等特性进行了分析.仿真结果验证了所提出方法的有效性.

  2. Automatic Vehicle Trajectory Extraction for Traffic Analysis from Aerial Video Data

    Science.gov (United States)

    Apeltauer, J.; Babinec, A.; Herman, D.; Apeltauer, T.

    2015-03-01

    This paper presents a new approach to simultaneous detection and tracking of vehicles moving through an intersection in aerial images acquired by an unmanned aerial vehicle (UAV). Detailed analysis of spatial and temporal utilization of an intersection is an important step for its design evaluation and further traffic inspection. Traffic flow at intersections is typically very dynamic and requires continuous and accurate monitoring systems. Conventional traffic surveillance relies on a set of fixed cameras or other detectors, requiring a high density of the said devices in order to monitor the intersection in its entirety and to provide data in sufficient quality. Alternatively, a UAV can be converted to a very agile and responsive mobile sensing platform for data collection from such large scenes. However, manual vehicle annotation in aerial images would involve tremendous effort. In this paper, the proposed combination of vehicle detection and tracking aims to tackle the problem of automatic traffic analysis at an intersection from visual data. The presented method has been evaluated in several real-life scenarios.

  3. Analysis of Seed Sorting Process by Estimation of Seed Motion Trajectories

    DEFF Research Database (Denmark)

    Buus, Ole Thomsen; Jørgensen, Johannes Ravn; Carstensen, Jens Michael

    2011-01-01

    Seed sorting is a mechanical process in which the goal is to achieve a high level of purity and quality in the final product. Prediction and control of such processes are generally considered very difficult. One possible solution is a systems identification approach in which the seeds and their m......Seed sorting is a mechanical process in which the goal is to achieve a high level of purity and quality in the final product. Prediction and control of such processes are generally considered very difficult. One possible solution is a systems identification approach in which the seeds...... and their movement are directly observed and data about important process parameters extracted. Image analysis was used to extract such data from the internal sorting process in one particular seed sorting device - the so-called “indented cylinder”. Twenty high speed image sequences were recorded of the indented...

  4. Hybrid trajectory spaces

    NARCIS (Netherlands)

    Collins, P.J.

    2005-01-01

    In this paper, we present a general framework for describing and studying hybrid systems. We represent the trajectories of the system as functions on a hybrid time domain, and the system itself by its trajectory space, which is the set of all possible trajectories. The trajectory space is given a na

  5. Analysis of Debris Trajectories at the Scaled Wind Farm Technology (SWiFT) Facility

    Energy Technology Data Exchange (ETDEWEB)

    White, Jonathan R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Burnett, Damon J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    Sandia National Laboratories operates the Scaled Wind Farm Technology Facility (SWiFT) on behalf of the Department of Energy Wind and Water Power Technologies Office. An analysis was performed to evaluate the hazards associated with debris thrown from one of SWiFT’s operating wind turbines, assuming a catastrophic failure. A Monte Carlo analysis was conducted to assess the complex variable space associated with debris throw hazards that included wind speed, wind direction, azimuth and pitch angles of the blade, and percentage of the blade that was separated. In addition, a set of high fidelity explicit dynamic finite element simulations were performed to determine the threshold impact energy envelope for the turbine control building located on-site. Assuming that all of the layered, independent, passive and active engineered safety systems and administrative procedures failed (a 100% failure rate of the safety systems), the likelihood of the control building being struck was calculated to be less than 5/10,000 and ballistic simulations showed that the control building would not provide passive protection for the majority of impact scenarios. Although options exist to improve the ballistic resistance of the control building, the recommendation is not to pursue them because there is a low probability of strike and there is an equal likelihood personnel could be located at similar distances in other areas of the SWiFT facility which are not passively protected, while the turbines are operating. A fenced exclusion area has been created around the turbines which restricts access to the boundary of the 1/100 strike probability. The overall recommendation is to neither relocate nor improve passive protection of the control building as the turbine safety systems have been improved to have no less than two independent, redundant, high quality engineered safety systems. Considering this, in combination with a control building strike probability of less than 5/10,000, the

  6. Eye safety analysis for non-uniform retinal scanning laser trajectories

    Science.gov (United States)

    Schelinski, Uwe; Dallmann, Hans-Georg; Grüger, Heinrich; Knobbe, Jens; Pügner, Tino; Reinig, Peter; Woittennek, Franziska

    2016-03-01

    Scanning the retinae of the human eyes with a laser beam is an approved diagnosis method in ophthalmology; moreover the retinal blood vessels form a biometric modality for identifying persons. Medical applied Scanning Laser Ophthalmoscopes (SLOs) usually contain galvanometric mirror systems to move the laser spot with a defined speed across the retina. Hence, the load of laser radiation is uniformly distributed and eye safety requirements can be easily complied. Micro machined mirrors also known as Micro Electro Mechanical Systems (MEMS) are interesting alternatives for designing retina scanning systems. In particular double-resonant MEMS are well suited for mass fabrication at low cost. However, their Lissajous-shaped scanning figure requires a particular analysis and specific measures to meet the requirements for a Class 1 laser device, i.e. eye-safe operation. The scanning laser spot causes a non-uniform pulsing radiation load hitting the retinal elements within the field of view (FoV). The relevant laser safety standards define a smallest considerable element for eye-related impacts to be a point source that is visible with an angle of maximum 1.5 mrad. For non-uniform pulsing expositions onto retinal elements the standard requires to consider all particular impacts, i.e. single pulses, pulse sequences in certain time intervals and cumulated laser radiation loads. As it may be expected, a Lissajous scanning figure causes the most critical radiation loads at its edges and borders. Depending on the applied power the laser has to be switched off here to avoid any retinal injury.

  7. [Bloodstain pattern analysis on examples from practice: Are calculations with application parabolic trajectory usable?].

    Science.gov (United States)

    Makovický, Peter; Matlach, Radek; Pokorná, Olga; Mošna, František; Makovický, Pavol

    2015-01-01

    The bloodstain pattern analysis (BPA) is useful in the forensic medicine. In Czechoslovakian criminology is this method not commonly used. The objective of this work is to calculate the impact length, height and distance splashing of blood drops. The results are compared with the real values for specific cases. It is also compared to calculate the angle of incidence of blood drops, using sinα with a form using tgα. For this purposes we used two different character cases from practice with well-preserved condition and readable blood stains. Selected blood stains were documented in order to calculate the angle of incidence of blood drops and to calculateorigin splashes. For this drop of blood, the distance of impact of the drops of blood (x), the height of the sprayed blood drops (y) and the length of the flight path the drop of blood (l). The obtained data was retrospectively analysed for the two models. The first straight line is represented by the triangle (M1) and the other is the parabolic model (M2). The formulae were derived using the Euler substitution. The results show that the angle of incidence of the drop of blood can be calculated as sinα and the tgα. When applying, the triangle is appropriate to consider the application and sinα parabolic requires the calculation of the angle of incidence drops of blood tgα. Parabola is useful for the BPA. In Czechoslovakian should be providing workplace training seminars BPA primarily intended for forensic investigators.We recommend the use of this method during investigations, verification of acts in forensic practice.

  8. Depression symptoms are persistent in Type 2 diabetes: risk factors and outcomes of 5-year depression trajectories using latent class growth analysis.

    Science.gov (United States)

    Whitworth, S R; Bruce, D G; Starkstein, S E; Davis, W A; Davis, T M E; Skinner, T C; Bucks, R S

    2017-08-01

    To describe the long-term trajectories of depression symptom severity in people with Type 2 diabetes, and to identify predictors and associates of these trajectories. A community-dwelling cohort of 1201 individuals with Type 2 diabetes from the Fremantle Diabetes Study Phase II was followed for 5 years. The nine-item version of the Patient Health Questionnaire was administered annually to assess depression symptoms, and biomedical and psychosocial measures were assessed at baseline and biennially. Latent class growth analysis was used to identify classes of depression severity trajectories and associated outcomes, and logistic regression models were used to determine predictors of class membership. Three trajectories of depression symptoms were identified: continuously low depression symptoms (85.2%); gradually worsening symptoms that then began to improve (persistent depression - low-start; 7.3%); and gradually improving symptoms which later worsened (persistent depression - high-start; 7.5%). Younger age, being a woman, and a lifetime history of major depressive disorder, were associated with greater risk of persistent depression symptoms. Persistent depression was associated with consistently higher BMI over time, but not with changes in HbA1c or self-monitoring of blood glucose. A subset of individuals with Type 2 diabetes is at risk of depression symptoms that remain elevated over time. Younger, overweight individuals with a history of depression may benefit from early and intensive depression management and ongoing follow-up as part of routine Type 2 diabetes care. © 2017 Diabetes UK.

  9. Potential emission flux to aerosol pollutants over Bengal Gangetic plain through combined trajectory clustering and aerosol source fields analysis

    Science.gov (United States)

    Kumar, D. Bharath; Verma, S.

    2016-09-01

    A hybrid source-receptor analysis was carried out to evaluate the potential emission flux to winter monsoon (WinMon) aerosols over Bengal Gangetic plain urban (Kolkata, Kol) and semi-urban atmospheres (Kharagpur, Kgp). This was done through application of fuzzy c-mean clustering to back-trajectory data combined with emission flux and residence time weighted aerosols analysis. WinMon mean aerosol optical depth (AOD) and angstrom exponent (AE) at Kol (AOD: 0.77; AE: 1.17) were respectively slightly higher than and nearly equal to that at Kgp (AOD: 0.71; AE: 1.18). Out of six source region clusters over Indian subcontinent and two over Indian oceanic region, the cluster mean AOD was the highest when associated with the mean path of air mass originating from the Bay of Bengal and the Arabian sea clusters at Kol and that from the Indo-Gangetic plain (IGP) cluster at Kgp. Spatial distribution of weighted AOD fields showed the highest potential source of aerosols over the IGP, primarily over upper IGP (e.g. Punjab, Haryana), lower IGP (e.g. Uttarpradesh) and eastern region (e.g. west Bengal, Bihar, northeast India) clusters. The emission flux contribution potential (EFCP) of fossil fuel (FF) emissions at surface (SL) of Kol/Kgp, elevated layer (EL) of Kol, and of biomass burning (BB) emissions at SL of Kol were primarily from upper, lower, upper/lower IGP clusters respectively. The EFCP of FF/BB emissions at Kgp-EL/SL, and that of BB at EL of Kol/Kgp were mainly from eastern region and Africa (AFR) clusters respectively. Though the AFR cluster was constituted of significantly high emission flux source potential of dust emissions, the EFCP of dust from northwest India (NWI) was comparable to that from AFR at Kol SL/EL.

  10. The trajectory and the related physical and social determinants of body mass index in elementary school children: results from the child and adolescent behaviors in long-term evolution study.

    Science.gov (United States)

    Lin, Li-Ju; Chang, Hsing-Yi; Luh, Dih-Ling; Hurng, Baai-Shyun; Yen, Lee-Lan

    2014-01-01

    This study explored developmental trajectory patterns of BMI and associated factors. Participants included 1,609 students who were followed from age 7 to 12 years. Data collection involved annual self-administered questionnaires and records of height and weight. An ecological model was used to identify the factors associated with BMI trajectories. Group-based trajectory models and multinomial logit models were used in the statistical analysis. There were gender differences in BMI trajectories. Among boys, four BMI trajectories were normal or slightly underweight, persistently normal weight, overweight becoming obese, and persistently obese. Among girls, four BMI trajectories were persistently slightly underweight, persistently normal weight, persistently overweight, and persistently obese. The mean BMI in each trajectory group demonstrated an upward trend over time. In boys, BMI trajectories were significantly associated with after-school exercise, academic performance, family interactions, overweight parents, and father's education level. In girls, BMI trajectories were significantly associated with television viewing or computer use, family interactions, peer interactions, and overweight parents. Children under age 7 years who are already overweight or obese are an important target for interventions. The different factors associated with BMI trajectories can be used for targeting high risk groups.

  11. The Trajectory and the Related Physical and Social Determinants of Body Mass Index in Elementary School Children: Results from the Child and Adolescent Behaviors in Long-Term Evolution Study

    Directory of Open Access Journals (Sweden)

    Li-Ju Lin

    2014-01-01

    Full Text Available This study explored developmental trajectory patterns of BMI and associated factors. Participants included 1,609 students who were followed from age 7 to 12 years. Data collection involved annual self-administered questionnaires and records of height and weight. An ecological model was used to identify the factors associated with BMI trajectories. Group-based trajectory models and multinomial logit models were used in the statistical analysis. There were gender differences in BMI trajectories. Among boys, four BMI trajectories were normal or slightly underweight, persistently normal weight, overweight becoming obese, and persistently obese. Among girls, four BMI trajectories were persistently slightly underweight, persistently normal weight, persistently overweight, and persistently obese. The mean BMI in each trajectory group demonstrated an upward trend over time. In boys, BMI trajectories were significantly associated with after-school exercise, academic performance, family interactions, overweight parents, and father’s education level. In girls, BMI trajectories were significantly associated with television viewing or computer use, family interactions, peer interactions, and overweight parents. Children under age 7 years who are already overweight or obese are an important target for interventions. The different factors associated with BMI trajectories can be used for targeting high risk groups.

  12. 3D bloodstain pattern analysis: ballistic reconstruction of the trajectories of blood drops and determination of the centres of origin of the bloodstains.

    Science.gov (United States)

    Buck, Ursula; Kneubuehl, Beat; Näther, Silvio; Albertini, Nicola; Schmidt, Lars; Thali, Michael

    2011-03-20

    For crime scene investigation in cases of homicide, the pattern of bloodstains at the incident site is of critical importance. The morphology of the bloodstain pattern serves to determine the approximate blood source locations, the minimum number of blows and the positioning of the victim. In the present work, the benefits of the three-dimensional bloodstain pattern analysis, including the ballistic approximation of the trajectories of the blood drops, will be demonstrated using two illustrative cases. The crime scenes were documented in 3D, using the non-contact methods digital photogrammetry, tachymetry and laser scanning. Accurate, true-to-scale 3D models of the crime scenes, including the bloodstain pattern and the traces, were created. For the determination of the areas of origin of the bloodstain pattern, the trajectories of up to 200 well-defined bloodstains were analysed in CAD and photogrammetry software. The ballistic determination of the trajectories was performed using ballistics software. The advantages of this method are the short preparation time on site, the non-contact measurement of the bloodstains and the high accuracy of the bloodstain analysis. It should be expected that this method delivers accurate results regarding the number and position of the areas of origin of bloodstains, in particular the vertical component is determined more precisely than using conventional methods. In both cases relevant forensic conclusions regarding the course of events were enabled by the ballistic bloodstain pattern analysis.

  13. Enhanced Dynamic Voltage Stability Support by VSC-HVDC for Offshore Wind Applications using Trajectory Sensitivity Analysis

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe; Liu, Leo

    2013-01-01

    . In this paper, VSC-HVDC transmission system is used to integrate a large-scale wind power plant into the onshore power grid. For different voltage support strategies of VSC-HVDC, a trajectory sensitivity analysisbased approach is proposed to find the minimum onshore VSC capacity with which the VSC-HVDC can...

  14. The Longitudinal Interplay of Adolescents' Self-Esteem and Body Image: A Conditional Autoregressive Latent Trajectory Analysis

    Science.gov (United States)

    Morin, Alexandre J. S.; Maiano, Christophe; Marsh, Herbert W.; Janosz, Michel; Nagengast, Benjamin

    2011-01-01

    Self-esteem and body image are central to coping successfully with the developmental challenges of adolescence. However, the current knowledge surrounding self-esteem and body image is fraught with controversy. This study attempts to clarify some of them by addressing three questions: (1) Are the intraindividual developmental trajectories of…

  15. Cluster analysis of an impact of air back-trajectories on aerosol optical properties at Hornsund, Spitsbergen

    Directory of Open Access Journals (Sweden)

    A. Rozwadowska

    2009-07-01

    Full Text Available In this paper spectra of aerosol optical thickness from AERONET (AErosol RObotic NETwork station at Hornsund in the southern part of Spitsbergen were employed to study the impact of air mass history on aerosol optical thickness (AOT(500 and Angstrom coefficient. Backward trajectories computed by means of NOAA HYSPLIT model were used to trace air history. It was found that in spring changes in AOT values over the Hornsund station were influenced by the at least 8-day trajectories of air, which was advected both in free troposphere and in the boundary layer. However, the free tropospheric advection was dominating. In summer the AOT variability was created mainly by local conditions, local direction and speed of advection (1-day trajectories. During the ASTAR 2007 campaign aerosols near Hornsund showed low AOT values ranging from 0.06 to 0.09, which is lower than the mean AOT(500 for spring seasons from 2005 to 2007 (0.110±0.007; mean ± standard deviation of mean. The 9 April 2007 with AOT(500=0.147 was an exception. Back-trajectories belonged to the clusters of low and average cluster mean AOT value. Beside the maximum AOT of the 9 April 2007, the observed AOT values were close to the means for the clusters to which they belonged or were lower than the means.

  16. Cluster analysis of the impact of air back-trajectories on aerosol optical properties at Hornsund, Spitsbergen

    Directory of Open Access Journals (Sweden)

    A. Rozwadowska

    2010-02-01

    Full Text Available In this paper, spectra of aerosol optical thickness from the AERONET (AErosol RObotic NETwork station at Hornsund in the southern part of Spitsbergen were employed to study the impact of air mass history on aerosol optical thickness for wavelength λ=500 nm – AOT(500 – and the Ångström exponent. Backward trajectories computed, using the NOAA HYSPLIT model, were used to trace air history. It was found that in spring, the changes in AOT values over the Hornsund station were strongly influenced by air mass trajectories 8 days or longer in duration, arriving both in the free troposphere and at an altitude of 1 km above sea level. Nevertheless, free tropospheric advection was dominant. AOT variability in summer was best explained by the local direction and speed of advection (1-day trajectories and was dominated by the effectiveness of cleansing processes. During the ASTAR 2007 campaign, the aerosols near Hornsund displayed low AOT values ranging from 0.06 to 0.09, which is lower than the mean AOT(500 for spring seasons from 2005 to 2007 (0.110±0.007; mean ± standard deviation of mean. 9 April 2007 with AOT(500=0.147 was exceptional. The back-trajectories belonged to clusters with low and average cluster mean AOT. Apart from the maximum AOT of 9 April 2007, the observed AOT values were close to or lower than the means for the clusters to which they belonged.

  17. The Longitudinal Interplay of Adolescents' Self-Esteem and Body Image: A Conditional Autoregressive Latent Trajectory Analysis

    Science.gov (United States)

    Morin, Alexandre J. S.; Maiano, Christophe; Marsh, Herbert W.; Janosz, Michel; Nagengast, Benjamin

    2011-01-01

    Self-esteem and body image are central to coping successfully with the developmental challenges of adolescence. However, the current knowledge surrounding self-esteem and body image is fraught with controversy. This study attempts to clarify some of them by addressing three questions: (1) Are the intraindividual developmental trajectories of…

  18. Integrated change detection and temporal trajectory analysis of coastal wetlands using high spatial resolution Korean Multi-Purpose Satellite series imagery

    Science.gov (United States)

    Nguyen, Hoang Hai; Tran, Hien; Sunwoo, Wooyeon; Yi, Jong-hyuk; Kim, Dongkyun; Choi, Minha

    2017-04-01

    A series of multispectral high-resolution Korean Multi-Purpose Satellite (KOMPSAT) images was used to detect the geographical changes in four different tidal flats between the Yellow Sea and the west coast of South Korea. The method of unsupervised classification was used to generate a series of land use/land cover (LULC) maps from satellite images, which were then used as input for temporal trajectory analysis to detect the temporal change of coastal wetlands and its association with natural and anthropogenic activities. The accurately classified LULC maps of KOMPSAT images, with overall accuracy ranging from 83.34% to 95.43%, indicate that these multispectral high-resolution satellite data are highly applicable to the generation of high-quality thematic maps for extracting wetlands. The result of the trajectory analysis showed that, while the variation of the tidal flats in the Gyeonggi and Jeollabuk provinces was well correlated with the regular tidal regimes, the reductive trajectory of the wetland areas belonging to the Saemangeum province was caused by a high degree of human-induced activities including large reclamation and urbanization. The conservation of the Jeungdo Wetland Protected Area in the Jeollanam province revealed that effective social and environmental policies could help in protecting coastal wetlands from degradation.

  19. 平面磁力研磨轨迹的研究与分析%Study and analysis on plane magnetic abrasive trajectory

    Institute of Scientific and Technical Information of China (English)

    焦安源; 邹艳华

    2011-01-01

    In this paper, complex polishing trajectory of magnetic brush has been modified and studied by use of newly designed experiment device. The results show the surface roughness and precision can be elevated, and the homogeneity of section shape can also be improved in improving process. In addition, the magnetic abrasive finishing results can be predicted by the theoretical analysis on polishing trajectory of magnetic brush.%利用自行设计的试验装置,改善了磁力刷的研磨轨迹.结果表明:改善磁力刷研磨轨迹后,不仅可以减小表面粗糙度值、提高平面精度,还改善了研磨截面微观形状均匀性.另外,可通过采取理论分析的方法对研磨效果进行预测.

  20. A new approach for estimating the Jupiter and Saturn gravity fields using Juno and Cassini measurements, trajectory estimation analysis, and a dynamical wind model optimization

    Science.gov (United States)

    Galanti, Eli; Durante, Daniele; Iess, Luciano; Kaspi, Yohai

    2017-04-01

    The ongoing Juno spacecraft measurements are improving our knowledge of Jupiter's gravity field. Similarly, the Cassini Grand Finale will improve the gravity estimate of Saturn. The analysis of the Juno and Cassini Doppler data will provide a very accurate reconstruction of spacial gravity variations, but these measurements will be very accurate only over a limited latitudinal range. In order to deduce the full gravity fields of Jupiter and Saturn, additional information needs to be incorporated into the analysis, especially with regards to the planets' wind structures. In this work we propose a new iterative approach for the estimation of Jupiter and Saturn gravity fields, using simulated measurements, a trajectory estimation model, and an adjoint based inverse thermal wind model. Beginning with an artificial gravitational field, the trajectory estimation model is used to obtain the gravitational moments. The solution from the trajectory model is then used as an initial guess for the thermal wind model, and together with an optimization method, the likely penetration depth of the winds is computed, and its uncertainty is evaluated. As a final step, the gravity harmonics solution from the thermal wind model is given back to the trajectory model, along with an estimate of their uncertainties, to be used as a priori for a new calculation of the gravity field. We test this method both for zonal harmonics only and with a full gravity field including tesseral harmonics. The results show that by using this method some of the gravitational moments are fitted better to the `observed' ones, mainly due to the added information from the dynamical model which includes the wind structure and its depth. Thus, it is suggested that the method presented here has the potential of improving the accuracy of the expected gravity moments estimated from the Juno and Cassini radio science experiments.

  1. Computing with spatial trajectories

    CERN Document Server

    2011-01-01

    Covers the fundamentals and the state-of-the-art research inspired by the spatial trajectory data Readers are provided with tutorial-style chapters, case studies and references to other relevant research work This is the first book that presents the foundation dealing with spatial trajectories and state-of-the-art research and practices enabled by trajectories

  2. The Longitudinal Interplay of Adolescents' Self-Esteem and Body Image: A Conditional Autoregressive Latent Trajectory Analysis.

    Science.gov (United States)

    Morin, Alexandre J S; Maïano, Christophe; Marsh, Herbert W; Janosz, Michel; Nagengast, Benjamin

    2011-04-11

    Self-esteem and body image are central to coping successfully with the developmental challenges of adolescence. However, the current knowledge surrounding self-esteem and body image is fraught with controversy. This study attempts to clarify some of them by addressing three questions: (1) Are the intraindividual developmental trajectories of self-esteem and body image stable across adolescence? (2) What is the direction of the relations between body image and self-esteem over time? (3) What is the role of gender, ethnicity, and pubertal development on those trajectories? This study relies on Autoregressive Latent Trajectory analyses based on data from a 4-year, 6-wave, prospective longitudinal study of 1,001 adolescents. Self-esteem and body image levels remained high and stable over time, although body image levels also tended to increase slightly. The results show that levels of self-esteem were positively influenced by levels of body image. However, these effects remained small and most of the observed associations were cross-sectional. Finally, the effects of pubertal development on body image and self-esteem levels were mostly limited to non-Caucasian females who appeared to benefit from more advanced pubertal development. Conversely, Caucasian females presented the lowest self-esteem and body image levels of all, although for them more advanced pubertal development levels were associated with a slight rise in body image over time.

  3. Network Applications for Group-Based Learning: Is More Better?

    Science.gov (United States)

    Veen, Jan; Collis, Betty; Jones, Val

    2003-01-01

    Group-based learning is being introduced into many settings in higher education. Is this a sustainable development with respect to the resources required? Under what conditions can group-based learning be applied successfully in distance education and in increasingly flexible campus-based learning? Can networked support facilitate and enrich…

  4. 木星探测轨道分析与设计%Jupiter Exploration Mission Analysis and Trajectory Design

    Institute of Scientific and Technical Information of China (English)

    陈杨; 宝音贺西; 李俊峰

    2012-01-01

    The trajectory design for Jupiter exploration mission is investigated in this paper. The differences between Jupiter exploration trajectory and Mars or Venus exploration trajectory are mainly concerned about. Firstly, the selection of the Jupiter-centered orbit is analyzed based on the Galileo Jupiter mission. As for the Earth-Jupiter transfer orbit, the fuel consumption of the direct transfer is too large. So the energy-saving technologies such as the planetary gravity assist should be used for the trajectory to the Jupiter. The different sequences of planetary gravity assist for the trajectory from the Earth to the Jupiter are examined by applying the Particle Swarm Optimization (PSO). According to the searching results, Venus-Earth-Earth gravity assist (VEEGA) is the most effective gravity-assist sequence for the Jupiter mission. During the Jupiter mission, the spacecraft will pass though the main asteroid belt which is between the orbits of Mars and Jupiter, and may encounter several asteroids. The Jupiter mission is able to combine with the main-belt asteroid flyby missions. The design method of the intermediate asteroid flyby trajectory is also considered. At last, an entire designed trajectory for the Jupiter mission launched in 2023 is presented.%研究了与木星探测相关的轨道设计问题.重点关注木星探测轨道与火星、金星等类地行星探测轨道的不同及由此带来的轨道设计难点.首先分析了绕木星探测任务轨道的选择.建立近似模型讨论了向木星飞行需要借助多颗行星的多次引力辅助,对地木转移的多种行星引力辅助序列,使用粒子群算法搜索了2020年至2025年之间的燃料最省飞行方案并对比得到了向木星飞行较好的引力辅助方式为金星-地球-地球引力辅助.结合多任务探测,研究了航天器在飞向木星途中穿越主小行星带飞越探测小行星的轨道设计.最后,给出2023年发射完整的结合引力辅助与小行星

  5. Research on Marketing strategies of Heilongjiang Forest Industry Group Based on SWOT Analysis%基于SWOT分析法的黑龙江森工集团营销策略研究

    Institute of Scientific and Technical Information of China (English)

    张慧

    2012-01-01

    Along with "Fraud-gate Scandal" of Davinci furniture, consumers begin to focus their eyes on the furniture industry. Furniture enterprises of Heilongjiang Forest Industry Group have always been playing a supporting role in China's furniture market. Especially due to their backward marketing strategies, they cannot capture market share, and achieve higher sales. This paper analyzes marketing opportunities of furniture enterprises of Heilongjiang Forest Industry Group in the furniture market by means of SWOT analysis, and thus puts forward some targeted strategies for their better development.%随着达芬奇家具"造假门"的出现,消费者的眼光又聚焦到家具行业,黑龙江省森工集团家具企业在中国家具市场中一直扮演着配角的角色,尤其是其自身的营销策略的落后使其无法抢占市场份额,达到更高的销售业绩。此文利用SWOT分析法对黑龙江省森工集团家具企业在家具市场的营销机会进行分析,从而为其更好的发展提出一些有针对性的策略。

  6. Using Synoptic Classification and Trajectory Analysis to Assess Air Quality during the Winter Heating Period in (U)rümqi, China

    Institute of Scientific and Technical Information of China (English)

    WANG Lili; WANG Yuesi; SUN Yang; LI Yuanyuan

    2012-01-01

    Synoptic patterns identified by an automated procedure employing principal- component analysis and a two-stage cluster analysis,and backward trajectory analysis clustered by the HYSPLIT4.9 model were used to examine air quality patterns over (U)rümqi,China,one of the most heavily polluted cities in the world.Six synoptic patterns representing different atmospheric circulation patterns and air-mass characteristics were classified during the winter heating periods from 2001 to 2008,and seven trajectory clusters representing different paths of air masses arriving at (U)rümqi were calculated during the winter heating periods from 2005 to 2008.Then air quality was evaluated using these two approaches,and significant variations were found across both synoptic patterns and trajectory clusters.The heaviest air-pollution episodes occurred when (U)rümqi was either in an extremely cold,strong anticyclone or at the front of a migrating cyclone.Both conditions were characterized by with light winds,cold,wet surface air,and relatively dry upper air.(U)rümqi was predominately influenced by air masses from the southwest and from local areas.Air pollution index (API) levels were highest for air masses originating from the southwest with a longer path or for the local area,because of transport from semi-desert/desert regions by strong winds and because of local heavy pollution emissions,respectively.The interactions between these two analytical approaches showed that poor diffusion conditions,together with local circulation,enhanced air pollution,besides,regional air-mass transport caused by strong winds contributed to serious air quality under relatively good diffusion conditions.

  7. Multivariate nonlinear regression analysis of trajectory tracking performance using force reflecting joystick in chronic stroke-induced hemiparesis.

    Science.gov (United States)

    Feng, Xin; Winters, Jack M

    2011-01-01

    Individualizing a neurorehabilitation training protocol requires understanding the performance of subjects with various capabilities under different task settings. We use multivariate regression to evaluate the performance of subjects with stroke-induced hemiparesis in trajectory tracking tasks using a force-reflecting joystick. A nonlinear effect was consistently shown in both dimensions of force field strength and impairment level for selected kinematic performance measures, with greatest sensitivity at lower force fields. This suggests that the form of a force field may play a different "role" for subjects with various impairment levels, and confirms that to achieve optimized therapeutic benefit, it is necessary to personalize interfaces.

  8. 1.6 μm DIAL Measurement and Back Trajectory Analysis of CO2 Concentration Profiles in the Lower-Atmosphere

    Science.gov (United States)

    Shibata, Y.; Nagasawa, C.; Abo, M.

    2016-12-01

    Carbon dioxide (CO2) is the primary greenhouse gas emitted through human activities. In addition to the ground level CO2 network, vertical CO2 concentration profiles also play an important role for the estimation of the carbon budget and global warming in the inversion method. Especially, for the detailed analysis of forest carbon dynamics and CO2 fluxes of urban area, vertical CO2 concentration profiles with high spatial and temporal resolution in the lower atmosphere have been conducted by a differential absorption lidar (DIAL). We have observed several vertical profiles of CO2 concentrations for nighttime and daytime from 0.25 to 2.5 km altitude with range resolution of 300 m and integration time of 1 hour. In order to extract information on the origin of the CO2 masses, one day back trajectories were calculated by using a three dimensional (3-D) atmospheric transport model. In many cases, CO2 low concentration layers of over 1.5km altitude were flown by westerly winds from the forest. In another case, high concentration layers of CO2 were flown from the urban areas. As the spectra of absorption lines of any molecules are influenced basically by the temperature in the atmosphere, laser beams of three wavelengths around a CO2 absorption spectrum are transmitted alternately to the atmosphere for simultaneous measurements of CO2 concentration and temperature profiles. Moreover, a few processing algorithms of CO2-DIAL are also performed for improvement of measurement accuracy. For computation of trajectories and drawing their figures, the JRA-25 data provided by the cooperative research project for the JRA-25 long-term reanalysis of the Japan Meteorological Agency (JMA) and the Central Research Institute of Electric Power Industry (CRIEPI) and the NIPR trajectory model (Tomikawa and Sato, 2005; http://firp-nitram.nipr.ac.jp) were used. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and

  9. The influence of work-family conflict trajectories on self-rated health trajectories in Switzerland: a life course approach.

    Science.gov (United States)

    Cullati, Stéphane

    2014-07-01

    Self-rated health (SRH) trajectories tend to decline over a lifetime. Moreover, the Cumulative Advantage and Disadvantage (CAD) model indicates that SRH trajectories are known to consistently diverge along socioeconomic positions (SEP) over the life course. However, studies of working adults to consider the influence of work and family conflict (WFC) on SRH trajectories are scarce. We test the CAD model and hypothesise that SRH trajectories diverge over time according to socioeconomic positions and WFC trajectories accentuate this divergence. Using longitudinal data from the Swiss Household Panel (N = 2327 working respondents surveyed from 2004 to 2010), we first examine trajectories of SRH and potential divergence over time across age, gender, SEP and family status using latent growth curve analysis. Second, we assess changes in SRH trajectories in relation to changes in WFC trajectories and divergence in SRH trajectories according to gender, SEP and family status using parallel latent growth curve analysis. Three measures of WFC are used: exhaustion after work, difficulty disconnecting from work, and work interference in private family obligations. The results show that SRH trajectories slowly decline over time and that the rate of change is not influenced by age, gender or SEP, a result which does not support the CAD model. SRH trajectories are significantly correlated with exhaustion after work trajectories but not the other two WFC measures. When exhaustion after work trajectories are taken into account, SRH trajectories of higher educated people decline slower compared to less educated people, supporting the CAD hypothesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. An Examination of "The Martian" Trajectory

    Science.gov (United States)

    Burke, Laura

    2015-01-01

    This analysis was performed to support a request to examine the trajectory of the Hermes vehicle in the novel "The Martian" by Andy Weir. Weir developed his own tool to perform the analysis necessary to provide proper trajectory information for the novel. The Hermes vehicle is the interplanetary spacecraft that shuttles the crew to and from Mars. It is notionally a Nuclear powered vehicle utilizing VASIMR engines for propulsion. The intent of this analysis was the determine whether the trajectory as it was outlined in the novel is consistent with the rules of orbital mechanics.

  11. Lunar and interplanetary trajectories

    CERN Document Server

    Biesbroek, Robin

    2016-01-01

    This book provides readers with a clear description of the types of lunar and interplanetary trajectories, and how they influence satellite-system design. The description follows an engineering rather than a mathematical approach and includes many examples of lunar trajectories, based on real missions. It helps readers gain an understanding of the driving subsystems of interplanetary and lunar satellites. The tables and graphs showing features of trajectories make the book easy to understand. .

  12. Identification of nitrogen dioxide and ozone source regions for an urban area in Korea using back trajectory analysis

    Science.gov (United States)

    Vellingiri, Kowsalya; Kim, Ki-Hyun; Lim, Jong-Myoung; Lee, Jin-Hong; Ma, Chang-Jin; Jeon, Byong-Hun; Sohn, Jong-Ryeul; Kumar, Pawan; Kang, Chang-Hee

    2016-07-01

    The NO2 and O3 in an urban background site of Seoul, Korea (Yongsan), were analyzed using hourly data collected from 2005 to 2013. The potential role of meteorological parameters in controlling air quality at the receptor site was analyzed using a conditional probability function. In addition, the relative contributions of such variables were examined for special cases (i.e., more than 60 ppb of NO2 and O3) with the help of trajectory. A potential source contribution function with a grid size resolution of 0.25° × 0.25° was used to determine the potential exogenous sources of NO2 and O3 for the study area. The results of both the trajectory and potential source contribution function analyses suggest that both the northern China region and local emission sources are the most influential source pathways contributing to the recent increase in NO2 concentration at the study site. In the case of O3, this role was shared by both oceanic and mountainous regions of China and Japan.

  13. Analysis and simulation of land use spatial pattern in Harbin prefecture based on trajectories and cellular automata-Markov modelling

    Science.gov (United States)

    Gong, Wenfeng; Yuan, Li; Fan, Wenyi; Stott, Philip

    2015-02-01

    There have been rapid population and accelerating urban growth with associated changes in land use and soil degradation in northeast China, an important grain-producing region. The development of integrated use of remote sensing, geographic information systems, and combined cellular automata- Markov models has provided new means of assessing changes in land use and land cover, and has enabled projection of trajectories into the future. We applied such techniques to the prefecture-level city of Harbin, the tenth largest city in China. We found that there had been significant losses of the land uses termed "cropland", "grassland", "wetland", and "floodplain" in favour of "built-up land" and lesser transformations from "floodplain" to "forestland" and "water body" over the 18-year period. However, the transition was not a simple process but a complex network of changes, interchanges, and multiple transitions. In the absence of effective land use policies, projection of past trajectories into a balance state in the future would result in the decline of cropland from 65.6% to 46.9% and the increase of built-up area from 7.7% to 23.0% relative to the total area of the prefecture in 1989. It also led to the virtual elimination of land use types such as unused wetland and floodplain.

  14. Dynamics Analysis of a Three-DOF Planar Serial-Parallel Mechanism for Active Dynamic Balancing with Respect to a Given Trajectory

    National Research Council Canada - National Science Library

    Wang, Kun; Luo, Minzhou; Mei, Tao; Zhao, Jianghai; Cao, Yi

    2013-01-01

    .... Trajectory-based dynamic balancing is a technique that brings additional mechanisms to unbalanced mechanisms with the purpose of actuating the original mechanism to move along a predefined trajectory...

  15. Trajectory P system

    Institute of Scientific and Technical Information of China (English)

    Subbaiah Annadurai; Thiyagarajan Kalyani; Vincent Rajkumar Dare; Durairaj Gnanaraj Thomas

    2008-01-01

    Membrane computing is a branch of natural computing aiming to abstract computing ideas for the structure and the functioning of living cells as well as from the way the cells are organized in tissues or higher-order structures.Trajectories are used as a tool for modeling language operations and other related objects.A trajectory P system consists of a membrane structure in which the object in each membrane is a collection of words and the evolutionary rules are given in terms of trajectories.In this paper,we present some properties of trajectory P systems.

  16. Point Groups Based on Methane and Adamantane (Td) Skeletons.

    Science.gov (United States)

    Fujita, Shinsaku

    1986-01-01

    Describes a procedure for constructing point groups based on the symmetric parent molecules of methane and adamantane. Intended for use in teaching concepts such as subgroups and cosets to beginners in group theory. (TW)

  17. Evolutionary trajectory of channel planforms in the middle Garonne River (Toulouse, SW France) over a 130-year period: Contribution of mixed multiple factor analysis (MFAmix)

    Science.gov (United States)

    David, Mélodie; Labenne, Amaury; Carozza, Jean-Michel; Valette, Philippe

    2016-04-01

    The purpose of this study is to propose a methodological essay for defining evolutionary trajectories of channel planforms and to examine the channel change in the middle Garonne River (southwest France) over a 130-year period. The study focuses on a reach of ~ 90 km situated downstream from the city of Toulouse. A set of four historical maps (1868, 1940s, 1970s, and 2000s) is used to build a geomorphometric diachronic database. Data processing through mixed multiple factor analysis (MFAmix) and hierarchical cluster analysis (HCA) allows distinction between four homogeneous zones within the study reach, depending on their evolutionary trajectories. Channel behavior in the upstream and median zones evolved as of the beginning of the study period (narrowing of the fluvial area, colonization by vegetation, and removal of alluvial bars), likely owing to punctual anthropogenic actions. The downstream zone is characterized by stabilization of the channel and alluvial bar removal over the second half of the twentieth century, coinciding with the campaign undertaken by French local authorities between 1960 and 1984 to protect river banks. The role of climate transition between the Little Ice Age (LIA) and the onset of the Global Warming period (GW) is also discussed. Results generally are consistent with the chronology established for most European rivers.

  18. Zero- vs. one-dimensional, parametric vs. non-parametric, and confidence interval vs. hypothesis testing procedures in one-dimensional biomechanical trajectory analysis.

    Science.gov (United States)

    Pataky, Todd C; Vanrenterghem, Jos; Robinson, Mark A

    2015-05-01

    Biomechanical processes are often manifested as one-dimensional (1D) trajectories. It has been shown that 1D confidence intervals (CIs) are biased when based on 0D statistical procedures, and the non-parametric 1D bootstrap CI has emerged in the Biomechanics literature as a viable solution. The primary purpose of this paper was to clarify that, for 1D biomechanics datasets, the distinction between 0D and 1D methods is much more important than the distinction between parametric and non-parametric procedures. A secondary purpose was to demonstrate that a parametric equivalent to the 1D bootstrap exists in the form of a random field theory (RFT) correction for multiple comparisons. To emphasize these points we analyzed six datasets consisting of force and kinematic trajectories in one-sample, paired, two-sample and regression designs. Results showed, first, that the 1D bootstrap and other 1D non-parametric CIs were qualitatively identical to RFT CIs, and all were very different from 0D CIs. Second, 1D parametric and 1D non-parametric hypothesis testing results were qualitatively identical for all six datasets. Last, we highlight the limitations of 1D CIs by demonstrating that they are complex, design-dependent, and thus non-generalizable. These results suggest that (i) analyses of 1D data based on 0D models of randomness are generally biased unless one explicitly identifies 0D variables before the experiment, and (ii) parametric and non-parametric 1D hypothesis testing provide an unambiguous framework for analysis when one׳s hypothesis explicitly or implicitly pertains to whole 1D trajectories.

  19. Preliminary Analysis of Low-Thrust Gravity Assist Trajectories by An Inverse Method and a Global Optimization Technique.

    Science.gov (United States)

    de Pascale, P.; Vasile, M.; Casotto, S.

    The design of interplanetary trajectories requires the solution of an optimization problem, which has been traditionally solved by resorting to various local optimization techniques. All such approaches, apart from the specific method employed (direct or indirect), require an initial guess, which deeply influences the convergence to the optimal solution. The recent developments in low-thrust propulsion have widened the perspectives of exploration of the Solar System, while they have at the same time increased the difficulty related to the trajectory design process. Continuous thrust transfers, typically characterized by multiple spiraling arcs, have a broad number of design parameters and thanks to the flexibility offered by such engines, they typically turn out to be characterized by a multi-modal domain, with a consequent larger number of optimal solutions. Thus the definition of the first guesses is even more challenging, particularly for a broad search over the design parameters, and it requires an extensive investigation of the domain in order to locate the largest number of optimal candidate solutions and possibly the global optimal one. In this paper a tool for the preliminary definition of interplanetary transfers with coast-thrust arcs and multiple swing-bys is presented. Such goal is achieved combining a novel methodology for the description of low-thrust arcs, with a global optimization algorithm based on a hybridization of an evolutionary step and a deterministic step. Low thrust arcs are described in a 3D model in order to account the beneficial effects of low-thrust propulsion for a change of inclination, resorting to a new methodology based on an inverse method. The two-point boundary values problem (TPBVP) associated with a thrust arc is solved by imposing a proper parameterized evolution of the orbital parameters, by which, the acceleration required to follow the given trajectory with respect to the constraints set is obtained simply through

  20. Trajectory Analysis of Cloud Properties During the 2014-2015 Holuhraun Lava Field Fissure Eruption in Iceland

    Science.gov (United States)

    Berry, S. E.; Hartmann, D. L.

    2016-12-01

    One of the major uncertainties in climate models and our understanding of anthropogenic effects on the atmosphere is the effect of aerosols on clouds. Anomalously high concentrations of cloud condensation nuclei (CCN) tend to increase cloud droplet concentrations and decrease droplet size leading to cloud brightening, known as the first indirect effect, and reduce the efficiency of precipitation processes leading to longer persistence times, known as the second indirect effect. In pre-industrial times, volcanoes were believed to be a primary source of CCN. The 2014-2015 fissure eruption at the Holuhraun lava field in Iceland, lasting from August 31, 2014 to February 28, 2015, released up to 120kt of sulfur dioxide per day at its peak, dwarfing all anthropogenic sulfur sources in the region. The continuity, magnitude, and length of the eruption makes it an ideal opportunity to examine the cloud-aerosol first indirect effect. Previous studies have shown the average cloud droplet effective radius in the region to drop to its lowest value recorded in the MODIS data record during September and October when the eruption was strongest. We aim to understand how this alteration of cloud properties occurred along parcel paths during the height of the eruption and establish a parcel relative mean magnitude change and activation time. Utilizing MODIS AQUA measurements and HYSPLIT forward trajectories, we composite cloud droplet effective radius, optical depth, and other cloud variables along trajectories, then compare to previous years with similar meteorology. We hope to provide a real world case by which to verify Lagrangian framed cloud-aerosol interactions and pre-industrial models.

  1. Predictors of severe psychological distress trajectory after nuclear disaster: evidence from the Fukushima Health Management Survey

    Science.gov (United States)

    Oe, Misari; Maeda, Masaharu; Nagai, Masato; Yasumura, Seiji; Yabe, Hirooki; Suzuki, Yuriko; Harigane, Mayumi; Ohira, Tetsuya; Abe, Masafumi

    2016-01-01

    Objectives The Fukushima Daiichi Nuclear Power Plant accident, which occurred after the Great East Japan Earthquake and Tsunami in March 2011, may have a considerable long-term impact on the lives of area residents. The aims of this study were to determine the trajectories of psychological distress using 3-year consecutive data, and to find predictive factors of severe distress that may also prove useful for public health intervention. Methods Data were obtained on 12 371 residents who were registered in the municipalities categorised as complete evacuation areas for 3 years after the disaster and who completed an assessment in each of the 3 years. Results Using group-based trajectory modelling, we identified four trajectory patterns distinguished by the levels of psychological distress, which gradually improved over time in all trajectories. Subjective sleep insufficiency, problem drinking, poor social support and perception of radiation risk 3 years after the accident were associated with the severity of psychological distress, according to the multivariate analysis. Conclusions The identified factors may be useful for community-based mental healthcare over the long term following a nuclear disaster. PMID:27798033

  2. Association between body mass index percentile trajectories in infancy and adiposity in childhood and early adulthood.

    Science.gov (United States)

    Kwon, Soyang; Janz, Kathleen F; Letuchy, Elena M; Burns, Trudy L; Levy, Steven M

    2017-01-01

    To identify distinct body mass index (BMI) percentile trajectories during early childhood and examine adiposity levels in childhood and early adulthood according to the BMI percentile trajectories. Iowa Fluoride Study cohort parents (n = 1,093) reported their child's anthropometric data on average six times between ages 0 and 23 months. A subset of the cohort underwent DXA scans at approximately age 8 years (n = 495) and again at approximately age 19 years (n = 314). Group-based trajectory analysis was conducted to identify distinct BMI percentile trajectories from ages 0 to 23 months. Sex-specific age-adjusted linear regression analyses were conducted to compare fat mass index in childhood and early adulthood among subgroups that follow the distinct BMI percentile patterns. Four BMI percentile patterns were identified: consistently low (group 1: 9.8%), increase in the second year (group 2: 33.7%), increase in the first year (group 3: 23.9%), and consistently high (group 4: 32.6%). Compared with group 2 females, groups 3 and 4 females had higher fat mass index in childhood and early adulthood (P BMI percentile in the first year of life, as opposed to a steep increase in the second year of life, may have higher body fat later in life, but this was not found in males. © 2016 The Obesity Society.

  3. Trajectories of Intimate Partner Violence Victimization

    Directory of Open Access Journals (Sweden)

    Kevin M. Swartout

    2012-08-01

    Full Text Available Introduction: The purposes of this study were to assess the extent to which latent trajectories of female intimate partner violence (IPV victimization exist; and, if so, use negative childhood experiences to predict trajectory membership.Methods: We collected data from 1,575 women at 5 time-points regarding experiences during adolescence and their 4 years of college. We used latent class growth analysis to fit a series of personcentered, longitudinal models ranging from 1 to 5 trajectories. Once the best-fitting model was selected, we used negative childhood experience variables—sexual abuse, physical abuse, and witnessing domestic violence—to predict most-likely trajectory membership via multinomial logistic regression.Results: A 5-trajectory model best fit the data both statistically and in terms of interpretability. The trajectories across time were interpreted as low or no IPV, low to moderate IPV, moderate to low IPV, high to moderate IPV, and high and increasing IPV, respectively. Negative childhood experiences differentiated trajectory membership, somewhat, with childhood sexual abuse as a consistent predictor of membership in elevated IPV trajectories.Conclusion: Our analyses show how IPV risk changes over time and in different ways. These differential patterns of IPV suggest the need for prevention strategies tailored for women that consider victimization experiences in childhood and early adulthood. [West J Emerg Med. 2012;13(3:272–277.

  4. Dynamic drag force based on iterative density mapping: A new numerical tool for three-dimensional analysis of particle trajectories in a dielectrophoretic system.

    Science.gov (United States)

    Knoerzer, Markus; Szydzik, Crispin; Tovar-Lopez, Francisco Javier; Tang, Xinke; Mitchell, Arnan; Khoshmanesh, Khashayar

    2016-02-01

    Dielectrophoresis is a widely used means of manipulating suspended particles within microfluidic systems. In order to efficiently design such systems for a desired application, various numerical methods exist that enable particle trajectory plotting in two or three dimensions based on the interplay of hydrodynamic and dielectrophoretic forces. While various models are described in the literature, few are capable of modeling interactions between particles as well as their surrounding environment as these interactions are complex, multifaceted, and computationally expensive to the point of being prohibitive when considering a large number of particles. In this paper, we present a numerical model designed to enable spatial analysis of the physical effects exerted upon particles within microfluidic systems employing dielectrophoresis. The model presents a means of approximating the effects of the presence of large numbers of particles through dynamically adjusting hydrodynamic drag force based on particle density, thereby introducing a measure of emulated particle-particle and particle-liquid interactions. This model is referred to as "dynamic drag force based on iterative density mapping." The resultant numerical model is used to simulate and predict particle trajectory and velocity profiles within a microfluidic system incorporating curved dielectrophoretic microelectrodes. The simulated data are compared favorably with experimental data gathered using microparticle image velocimetry, and is contrasted against simulated data generated using traditional "effective moment Stokes-drag method," showing more accurate particle velocity profiles for areas of high particle density.

  5. Autonomous Navigation Performance Evaluation Method Based on Trajectory Analysis%基于轨迹分析的自主导航性能评估方法

    Institute of Scientific and Technical Information of China (English)

    王勇鑫; 钱徽; 金卓军; 朱淼良

    2011-01-01

    在马尔可夫决策模型框架下,提出一种基于轨迹分析的计算评估方法,通过分析驾驶回报设置和车辆轨迹的特征期望衡量自主导航系统的性能.假定回报函数是回报特征的线性组合,通过逼近不同的车辆自主驾驶策略,求解应用于沙盒场景的回报设置,从而仿真导航轨迹的特征期望.实验结果表明,该方法能对自主导航系统的轨迹数据实现定性和定量评估.%This paper proposes a novel trajectory-analysis-based performance evaluation method, which assesses and compares the navigation performances by reward settings and feature expectations under Markov Decision Process(MDP) framework. Assuming that the reward function is a linear combination of known features, this method evaluates reward settings by approximating the driving styles of different land autonomous navigation systems. On this basis, reward settings are used to simulate the feature expectations of navigation trajectories in a standard land navigation environment called the sandbox. Experimental results show the validity of this method in both qualitative and quantitative performance evaluations.

  6. A tensorial approach to the inversion of group-based phylogenetic models.

    Science.gov (United States)

    Sumner, Jeremy G; Jarvis, Peter D; Holland, Barbara R

    2014-12-04

    Hadamard conjugation is part of the standard mathematical armoury in the analysis of molecular phylogenetic methods. For group-based models, the approach provides a one-to-one correspondence between the so-called "edge length" and "sequence" spectrum on a phylogenetic tree. The Hadamard conjugation has been used in diverse phylogenetic applications not only for inference but also as an important conceptual tool for thinking about molecular data leading to generalizations beyond strictly tree-like evolutionary modelling. For general group-based models of phylogenetic branching processes, we reformulate the problem of constructing a one-one correspondence between pattern probabilities and edge parameters. This takes a classic result previously shown through use of Fourier analysis and presents it in the language of tensors and group representation theory. This derivation makes it clear why the inversion is possible, because, under their usual definition, group-based models are defined for abelian groups only. We provide an inversion of group-based phylogenetic models that can implemented using matrix multiplication between rectangular matrices indexed by ordered-partitions of varying sizes. Our approach provides additional context for the construction of phylogenetic probability distributions on network structures, and highlights the potential limitations of restricting to group-based models in this setting.

  7. Personalized trajectory matching in spatial networks

    KAUST Repository

    Shang, Shuo

    2013-07-31

    With the increasing availability of moving-object tracking data, trajectory search and matching is increasingly important. We propose and investigate a novel problem called personalized trajectory matching (PTM). In contrast to conventional trajectory similarity search by spatial distance only, PTM takes into account the significance of each sample point in a query trajectory. A PTM query takes a trajectory with user-specified weights for each sample point in the trajectory as its argument. It returns the trajectory in an argument data set with the highest similarity to the query trajectory. We believe that this type of query may bring significant benefits to users in many popular applications such as route planning, carpooling, friend recommendation, traffic analysis, urban computing, and location-based services in general. PTM query processing faces two challenges: how to prune the search space during the query processing and how to schedule multiple so-called expansion centers effectively. To address these challenges, a novel two-phase search algorithm is proposed that carefully selects a set of expansion centers from the query trajectory and exploits upper and lower bounds to prune the search space in the spatial and temporal domains. An efficiency study reveals that the algorithm explores the minimum search space in both domains. Second, a heuristic search strategy based on priority ranking is developed to schedule the multiple expansion centers, which can further prune the search space and enhance the query efficiency. The performance of the PTM query is studied in extensive experiments based on real and synthetic trajectory data sets. © 2013 Springer-Verlag Berlin Heidelberg.

  8. Risk analysis for rumor propagation in metropolises based on improved 8-state ICSAR model and dynamic personal activity trajectories

    Science.gov (United States)

    Zhang, N.; Huang, H.; Duarte, M.; Zhang, J.

    2016-06-01

    Social media has developed extremely fast in metropolises in recent years resulting in more and more rumors disturbing our daily lives. Knowing the characteristics of rumor propagation in metropolises can help the government make efficient rumor refutation plans. In this paper, we established a dynamic spatio-temporal comprehensive risk assessment model for rumor propagation based on an improved 8-state ICSAR model (Ignorant, Information Carrier, Information Spreader, Advocate, Removal), large personal activity trajectory data, and governmental rumor refutation (anti-rumor) scenarios. Combining these relevant data with the 'big' traffic data on the use of subways, buses, and taxis, we simulated daily oral communications among inhabitants in Beijing. In order to analyze rumor and anti-rumor competition in the actual social network, personal resistance, personal preference, conformity, rumor intensity, government rumor refutation and other influencing factors were considered. Based on the developed risk assessment model, a long-term dynamic rumor propagation simulation for a seven day period was conducted and a comprehensive rumor propagation risk distribution map was obtained. A set of the sensitivity analyses were conducted for different social media and propagation routes. We assessed different anti-rumor coverage ratios and the rumor-spreading thresholds at which the government started to launch anti-rumor actions. The results we obtained provide worthwhile references useful for governmental decision making towards control of social-disrupting rumors.

  9. Mindfulness Training Promotes Upward Spirals of Positive Affect and Cognition: Multilevel and Autoregressive Latent Trajectory Modeling Analysis

    Directory of Open Access Journals (Sweden)

    Eric L Garland

    2015-02-01

    Full Text Available Recent theory suggests that positive psychological processes integral to health may be energized through the self-reinforcing dynamics of an upward spiral to counter emotion dysregulation. The present study examined positive emotion-cognition interactions among individuals in partial remission from depression who had been randomly assigned to treatment with mindfulness-based cognitive therapy (MBCT; n = 64 or a wait-list control condition (n = 66. We hypothesized that MBCT stimulates upward spirals by increasing positive affect and positive cognition. Experience sampling assessed changes in affect and cognition during 6 days before and after treatment, which were analyzed with a series of multilevel and autoregressive latent trajectory models. Findings suggest that MBCT was associated with significant increases in trait positive affect and momentary positive cognition, which were preserved through autoregressive and cross-lagged effects driven by global emotional tone. Findings suggest that daily positive affect and cognition are maintained by an upward spiral that might be promoted by mindfulness training.

  10. Identifying anthropogenic and natural influences on extreme pollution of respirable suspended particulates in Beijing using backward trajectory analysis.

    Science.gov (United States)

    Song, Yu; Miao, Weijie; Liu, Bing; Dai, Wei; Cai, Xuhui

    2008-06-15

    In China, daily respirable suspended particulate (RSP, particles with aerodynamic diameters less than 10 microm) concentrations exceeding 420 microg m(-3) are considered "hazardous" to health. These can lead to the premature onset of certain diseases and premature death of sick and elderly people; even healthy people are warned to avoid outdoor activity when RSP concentrations are high. Such high pollution levels are defined as extreme RSP pollution events. Recent epidemiological studies have shown that a distinct difference exists between the health effects caused by natural sources and anthropogenic sources, mandating knowledge of the source of extreme RSP pollution. Twenty-six extreme RSP pollution events were recorded in Beijing from January 2003 to December 2006. The HYSPLIT4 (Hybrid Single Particle Lagrangian Integrated Trajectory) model (Version 4) was used to discriminate the sources of these extreme RSP pollution events. The model found that twelve events were caused from natural sources (dust storms), nine events from anthropogenic sources (e.g., vehicles and industrial activities, etc.) under quasi-quiescent weather, and five events were from mixed causes. Identifying such events will be valuable in epidemiological studies on air pollution in Beijing.

  11. Finite-time Lagrangian transport analysis: Stable and unstable manifolds of hyperbolic trajectories and finite-time Lyapunov exponents

    CERN Document Server

    Branicki, Michal

    2009-01-01

    We consider issues associated with the Lagrangian characterisation of flow structures arising in aperiodically time-dependent vector fields that are only known on a finite time interval. A major motivation for the consideration of this problem arises from the desire to study transport and mixing problems in geophysical flows where the flow is obtained from a numerical solution, on a finite space-time grid, of an appropriate partial differential equation model for the velocity field. Of particular interest is the characterisation, location, and evolution of "transport barriers" in the flow, i.e. material curves and surfaces. We argue that a general theory of Lagrangian transport has to account for the effects of transient flow phenomena which are not captured by the infinite-time notions of hyperbolicity even for flows defined for all time. Notions of finite-time hyperbolic trajectories, their finite time stable and unstable manifolds, as well as finite-time Lyapunov exponent (FTLE) fields and associated Lagra...

  12. Reducing Social Loafing in Group-Based Projects

    Science.gov (United States)

    Perron, Brian E.

    2011-01-01

    Social loafing in group-based projects is a common problem for college teachers. This problem has received great attention, including a Quick Fix article by Stevens (2007), whose recommendations remain useful today, particularly the mechanism for peer evaluations--a key strategy for reducing social loafing. Since the publication of Stevens's…

  13. Analysis of the three-dimensional trajectories of dusts observed with a stereoscopic fast framing camera in the Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Shoji, M., E-mail: shoji@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Gifu (Japan); Masuzaki, S. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Gifu (Japan); Tanaka, Y. [Kanazawa University, Kakuma, Kanazawa 920-1192 (Japan); Pigarov, A.Yu.; Smirnov, R.D. [University of California at San Diego, La Jolla, CA 92093 (United States); Kawamura, G.; Uesugi, Y.; Yamada, H. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Gifu (Japan)

    2015-08-15

    The three-dimensional trajectories of dusts have been observed with two stereoscopic fast framing cameras installed in upper and outer viewports in the Large Helical Device (LHD). It shows that the dust trajectories locate in divertor legs and an ergodic layer around the main plasma confinement region. While it is found that most of the dusts approximately move along the magnetic field lines with acceleration, there are some dusts which have sharply curved trajectories crossing over the magnetic field lines. A dust transport simulation code was modified to investigate the dust trajectories in fully three dimensional geometries such as LHD plasmas. It can explain the general trend of most of observed dust trajectories by the effect of the plasma flow in the peripheral plasma. However, the behavior of the some dusts with sharply curved trajectories is not consistent with the simulations.

  14. Ornithopter transition trajectories

    Science.gov (United States)

    Dietl, John M.; Garcia, Ephrahim

    2010-04-01

    The design of stable trim conditions for forward flight and for hover has been achieved. In forward flight, an ornithopter is configured like a conventional airplane or large bird. Its fuselage is essentially horizontal and the wings heave in a vertical plane. In hover, however, the body pitches vertically so that the wing stroke in the horizontal plane. Thrust directed downward, the vehicle remains aloft while the downdraft envelops the tail to provide enough flow for vehicle control and stabilization. To connect these trajectories dynamically is the goal. The naïve approach-to choose two stable trajectories and switch between them-has been accomplished. A new approach is to establish an open-loop trajectory through a trajectory optimization algorithm-optimized for shortest altitude drop, shortest stopping distance, or lowest energy consumption.

  15. Automated Cooperative Trajectories

    Science.gov (United States)

    Hanson, Curt; Pahle, Joseph; Brown, Nelson

    2015-01-01

    This presentation is an overview of the Automated Cooperative Trajectories project. An introduction to the phenomena of wake vortices is given, along with a summary of past research into the possibility of extracting energy from the wake by flying close parallel trajectories. Challenges and barriers to adoption of civilian automatic wake surfing technology are identified. A hardware-in-the-loop simulation is described that will support future research. Finally, a roadmap for future research and technology transition is proposed.

  16. Finite-time Lagrangian transport analysis: stable and unstable manifolds of hyperbolic trajectories and finite-time Lyapunov exponents

    Directory of Open Access Journals (Sweden)

    M. Branicki

    2010-01-01

    Full Text Available We consider issues associated with the Lagrangian characterisation of flow structures arising in aperiodically time-dependent vector fields that are only known on a finite time interval. A major motivation for the consideration of this problem arises from the desire to study transport and mixing problems in geophysical flows where the flow is obtained from a numerical solution, on a finite space-time grid, of an appropriate partial differential equation model for the velocity field. Of particular interest is the characterisation, location, and evolution of transport barriers in the flow, i.e. material curves and surfaces. We argue that a general theory of Lagrangian transport has to account for the effects of transient flow phenomena which are not captured by the infinite-time notions of hyperbolicity even for flows defined for all time. Notions of finite-time hyperbolic trajectories, their finite time stable and unstable manifolds, as well as finite-time Lyapunov exponent (FTLE fields and associated Lagrangian coherent structures have been the main tools for characterising transport barriers in the time-aperiodic situation. In this paper we consider a variety of examples, some with explicit solutions, that illustrate in a concrete manner the issues and phenomena that arise in the setting of finite-time dynamical systems. Of particular significance for geophysical applications is the notion of flow transition which occurs when finite-time hyperbolicity is lost or gained. The phenomena discovered and analysed in our examples point the way to a variety of directions for rigorous mathematical research in this rapidly developing and important area of dynamical systems theory.

  17. Developmental Trajectories of Social Skills during Early Childhood and Links to Parenting Practices in a Japanese Sample.

    Science.gov (United States)

    Takahashi, Yusuke; Okada, Kensuke; Hoshino, Takahiro; Anme, Tokie

    2015-01-01

    This study used data from a nationwide survey in Japan to model the developmental course of social skills during early childhood. The goals of this study were to identify longitudinal profiles of social skills between 2 and 5 years of age using a group-based trajectory approach, and to investigate whether and to what extent parenting practices at 2 years of age predicted developmental trajectories of social skills during the preschool period. A relatively large sample of boys and girls (N > 1,000) was assessed on three social skill dimensions (Cooperation, Self-control, and Assertion) at four time points (ages 2, 3, 4, and 5), and on four parenting practices (cognitive and emotional involvement, avoidance of restriction and punishment, social stimulation, and social support for parenting) at age 2. The results indicated that for each social skill dimension, group-based trajectory models identified three distinct trajectories: low, moderate, and high. Multinomial regression analysis revealed that parenting practice variables showed differential contributions to development of child social skills. Specifically, Cooperation and Assertion were promoted by cognitive and emotional involvement, Self-control by social stimulation, and Assertion by avoidance of restriction and punishment. Abundant social support for parenting was not associated with higher child social skills trajectories. We found heterogeneity in developmental profiles of social skills during the preschool ages, and we identified parenting practices that contributed to different patterns of social skills development. We discussed the implications of higher-quality parenting practices on the improvement of child social skills across early childhood.

  18. Developmental Trajectories of Social Skills during Early Childhood and Links to Parenting Practices in a Japanese Sample.

    Directory of Open Access Journals (Sweden)

    Yusuke Takahashi

    Full Text Available This study used data from a nationwide survey in Japan to model the developmental course of social skills during early childhood. The goals of this study were to identify longitudinal profiles of social skills between 2 and 5 years of age using a group-based trajectory approach, and to investigate whether and to what extent parenting practices at 2 years of age predicted developmental trajectories of social skills during the preschool period. A relatively large sample of boys and girls (N > 1,000 was assessed on three social skill dimensions (Cooperation, Self-control, and Assertion at four time points (ages 2, 3, 4, and 5, and on four parenting practices (cognitive and emotional involvement, avoidance of restriction and punishment, social stimulation, and social support for parenting at age 2. The results indicated that for each social skill dimension, group-based trajectory models identified three distinct trajectories: low, moderate, and high. Multinomial regression analysis revealed that parenting practice variables showed differential contributions to development of child social skills. Specifically, Cooperation and Assertion were promoted by cognitive and emotional involvement, Self-control by social stimulation, and Assertion by avoidance of restriction and punishment. Abundant social support for parenting was not associated with higher child social skills trajectories. We found heterogeneity in developmental profiles of social skills during the preschool ages, and we identified parenting practices that contributed to different patterns of social skills development. We discussed the implications of higher-quality parenting practices on the improvement of child social skills across early childhood.

  19. "Traditional knowledge" and local development trajectories

    OpenAIRE

    2005-01-01

    The paper discusses the concept of "traditional knowledge": its definition, economic significance and role in shaping regional development trajectories. After outlining a conceptual framework for the analysis of traditional knowledge, the paper examines the changing position of traditional knowledge in two Italian regions that have followed quite different development trajectories since the 1950s: the "Sibillini Mountains Region", which has one of the most complex human landscapes in Europe, ...

  20. Hybrid 3-D rocket trajectory program. Part 1: Formulation and analysis. Part 2: Computer programming and user's instruction. [computerized simulation using three dimensional motion analysis

    Science.gov (United States)

    Huang, L. C. P.; Cook, R. A.

    1973-01-01

    Models utilizing various sub-sets of the six degrees of freedom are used in trajectory simulation. A 3-D model with only linear degrees of freedom is especially attractive, since the coefficients for the angular degrees of freedom are the most difficult to determine and the angular equations are the most time consuming for the computer to evaluate. A computer program is developed that uses three separate subsections to predict trajectories. A launch rail subsection is used until the rocket has left its launcher. The program then switches to a special 3-D section which computes motions in two linear and one angular degrees of freedom. When the rocket trims out, the program switches to the standard, three linear degrees of freedom model.

  1. When are emotions related to group-based appraisals? : A comparison between group-based emotions and general group emotions

    NARCIS (Netherlands)

    Kuppens, Toon; Yzerbyt, Vincent Y.

    2014-01-01

    In the literature on emotions in intergroup relations, it is not always clear how exactly emotions are group-related. Here, we distinguish between emotions that involve appraisals of immediate group concerns (i.e., group-based emotions) and emotions that do not. Recently, general group emotions, mea

  2. 基于ADAMS的危险作业机械手工作轨迹分析%Working Trajectory Analysis of Hazardous Operation Manipulator Based on ADAMS

    Institute of Scientific and Technical Information of China (English)

    赵亮亮; 马振书; 杜峰坡; 来升

    2011-01-01

    利用SolidWorks软件创建机械手的虚拟样机模型,采用D-H法对机械臂进行正向运动学分析和解算,为进一步验证解的正确性,运用ADAMS软件对机械臂运动特性进行仿真分析,得到了机械手处于2种抓取位姿时手爪形心随大臂俯仰的轨迹曲线,与经过正向运动学分析由Matlab绘制的曲线相吻合,这就证明了正向运动学分析的正确性.同时,基于ADAMS的机械手工作轨迹分析,为机械臂的优化设计及运动控制提供了参考依据.%The virtual model of the manipulator is established using SolidWorks,and the direct kinematics problem is analyzed based on the Denavit - Hartenberg method. In order to verify the accuracy of solutions, moving behavior simulation for the manipulator is analyzed depending on ADAMS,and trajectory curves of the gripper's centroid accompanied with the first arm's moving are drawn when the manipulator is set in the two kinds of working poses. The curves are consistent with the ones that are drawn by Matlab through analyzing direct kinematics,which proves the analytic results of direct kinematics to be right. In addition, the working trajectory analysis of the gripper provides a reference for optimal design and motion control of the manipulator.

  3. Body weight trajectories and risk of oesophageal and gastric cardia adenocarcinomas: a pooled analysis of NIH-AARP and PLCO Studies.

    Science.gov (United States)

    Petrick, Jessica L; Kelly, Scott P; Liao, Linda M; Freedman, Neal D; Graubard, Barry I; Cook, Michael B

    2017-03-28

    Elevated body mass index (BMI, kg m(-2)) has been consistently associated with oesophageal adenocarcinoma (EA) and gastric cardia adenocarcinoma (GCA) incidence. However, effects of adiposity over the life course in relation to EA/GCA have not been thoroughly explored. We pooled two prospective cohort studies: NIH-AARP Diet and Health Study and Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, with data on 409 796 individuals (633 EA, 415 GCA). At baseline, participants reported their height and weight at ages 20 and 50 years, and current. Body mass index trajectories were determined using latent class analysis. Hazard ratios (HRs) and 95% confidence intervals (CI) were estimated using proportional hazards regression. Compared with individuals with a BMIobesity (⩾30 kg m(-2)) by age 50 was associated with increased risks of EA (HR=2.90, 95% CI: 1.67-5.04) and GCA (HR=4.07, 95% CI: 2.32-7.15), compared with individuals with a normal weight (⩾18.5-<25 kg m(-2)) trajectory. Weight gain of ⩾20 kg between age 20 and baseline was also associated with a two times increased risk of EA (HR=1.97, 95% CI: 1.43-2.73) and more modestly with GCA (HR=1.40, 95% CI: 0.96-2.05). Being overweight in early adulthood and weight gain later in life were each associated with increased risks of EA and GCA. This underscores the potential of weight control programs for reducing EA and GCA risk.

  4. Origin of the Ion Foreshock in a Quasi-perpendicular Curved Collisionless Shock: Particles Trajectory Analysis in 2D PIC Simulations

    Science.gov (United States)

    Savoini, P.; Lembege, B.

    2015-12-01

    The ion foreshock located upstream of the Earth's shock wave is populated with ions having interacted with the shock, and then, reflected back with an high energy gain. Spacecrafts have clearly established the existence of two distinct populations in the quasi-perpendicular shock region (i.e. for 45° ≤ ΘBn ≤ 90°, where ΘBn is the angle between the shock normal and the upstream magnetic field) : (i) field-aligned ion beams or « FAB » characterized by a gyrotropic distribution, and (ii) gyro-phase bunched ions or « GPB » characterized by a NON gyrotropic distribution. One of the important unresolved problem is the exact origin of the particles contributing to these two populations. To our knowledge, it was the first time that full-particle simulations have been performed including self-consistently the shock front curvature and nonstationarity, and the time-of-flight effects. Our analysis evidences that these two backstreaming populations may be reflected by the front itself and can be differentiated both in terms of interaction time and trajectory within the shock front. In particular, simulations evidence that "GPB" population is characterized by a short interaction time (ΔTinter = 1 to 2 τci) while the "FAB" population corresponds to a much larger time range (from 1 τci to 10 τci), where tci is the upstream ion gyroperiod. Present individual ion trajectories evidence that "FAB" population shows a strong perpendicular drift at the shock front (i.e. strong dependence of the pitch angle to the perpendicular velocity) whereas the "GPB" population shows no perpendicular drift (i.e. its pitch angle is mainly driven by the parallel velocity). Such differences explain why the "FAB" population loses their gyro-phase coherency and become gyrotropic which is not the case for the "GPB". This important result was not expected and greatly simplifies the question of their origin.

  5. Comparative analysis of land use/cover change trajectories and their driving forces in two small watersheds in the western Loess Plateau of China

    Science.gov (United States)

    Wang, Dongchuan; Gong, Jianhua; Chen, Liding; Zhang, Lihui; Song, Yiquan; Yue, Yujuan

    2013-04-01

    To prevent soil loss and achieve better ecological environments, soil conservation measures have been taken during the past decades in the western Loess Plateau of China. In this paper, a case study was taken in Luoyu valley and Lver valley, two sub-watersheds of Xihe watershed and comparison was carried out between them. The main object of this study is to monitor land use/cover changes in the two similar small watersheds utilizing SPOT5 imageries by object-oriented human-computer interactive classification method, further develop the method of spatio-temporal analysis of land use/cover change by using pattern metrics of change trajectories and relative land use suitability index (R) in smaller watersheds, and make comparisons between the two similar small watersheds, taking water and soil conservation measures into consideration. Results show that combining GIS and RS, this method can be perfectly applied to make comparisons between different small watersheds with similar geographical backgrounds. And land use/cover spatiotemporal dynamic change characteristics can be preferably expressed by pattern metrics of change trajectories and R values based on topographical data. Different emphases have been laid according to their own geological backgrounds in the two watersheds and human activities have different effects on the landscapes of the two watersheds. The main change pattern is from slope farmland to terrace (322, the largest in Luoyu valley) or to economic fruit forest (344, the largest in Lver valley). R value of every slope grade in both of the two watersheds drops with the rising of slope degree on the whole and it shows that there is still much to do for people in the two watersheds in consideration that all the R values are still lower than 0.7.

  6. 木薯清洗机滚筒内运动轨迹的分析%Analysis of the Cassava Washing Machine Drum Trajectory

    Institute of Scientific and Technical Information of China (English)

    覃振友; 班彩霞; 周清; 李岩舟; 阳潮声

    2015-01-01

    Based on the analysis of the cassava washing machine drum trajectory , establishing the arc-parabolic trajecto-ry equations to study the innermost layer of the cassava in the cleaning machine drum movement minimum radius , the best divorce angle , maximum drop height , cleaning factor , the best drum speed and other relevant parameters , in order to remove the dirt and fibrous roots on the surface of cassava more quickly , improve the cleaning efficiency of the cassava washing machines .To further optimize the cassava washing machine , thereby improving the efficiency of the entire indus-trial production of cassava provides a solid theoretical basis .%通过对木薯清洗机滚筒内运动轨迹的分析,建立了圆弧—抛物线运动轨迹方程;研究了木薯在清洗机滚筒内运动的最内层最小半径、最佳脱离角、最大降落高度、清洗系数及滚筒最佳速度等相关参数,以更加快速地清除木薯表面的泥土和须根,提高木薯清洗机的清洗效率。该研究可为进一步优化木薯清洗机,从而提高整个木薯工业化生产的效率提供了坚实的理论依据。

  7. Compressing spatio-temporal trajectories

    DEFF Research Database (Denmark)

    Gudmundsson, Joachim; Katajainen, Jyrki; Merrick, Damian

    2009-01-01

    A trajectory is a sequence of locations, each associated with a timestamp, describing the movement of a point. Trajectory data is becoming increasingly available and the size of recorded trajectories is getting larger. In this paper we study the problem of compressing planar trajectories such tha...

  8. Cleaners' experiences with group-based workplace physical training

    DEFF Research Database (Denmark)

    Kirkelund, Lasse; Mortensen, Ole Steen; Holtermann, Andreas

    2012-01-01

    This study investigates how work-site health promotion intervention, by involving group-based physical coordination training, may increase participants’ social awareness of new ways to use the body. Purpose: We investigated cleaners’ experiences with a one-year health promotion intervention...... involving group-based physical coordination training (PCT) during working hours. Design: We conducted a qualitative evaluation using method triangulation; continuous unfocused participant observation during the whole intervention, semi-structured focus group interview, and individual written evaluations one...... for implementation seem to be important for sustained effects of health-promotion interventions in the workplace. Originality: The social character of the physical training facilitated a community of practice, which potentially supported the learning of new competencies, and how to improve the organization...

  9. Personality traits and group-based information behaviour

    DEFF Research Database (Denmark)

    Hyldegård, Jette

    2009-01-01

    Introduction. The relationship between hypothesised behaviour resulting from a personality test and actual information behaviour resulting from a group-based assignment process is addressed in this paper. Methods. Three voluntary groups of ten librarianship and information science students were...... but there were also deviations, which were found that seemed to be related to the group-work context. The importance of studying personality traits in context has further been confirmed....

  10. An Event Grouping Based Algorithm for University Course Timetabling Problem

    OpenAIRE

    Kralev, Velin; Kraleva, Radoslava; Yurukov, Borislav

    2016-01-01

    This paper presents the study of an event grouping based algorithm for a university course timetabling problem. Several publications which discuss the problem and some approaches for its solution are analyzed. The grouping of events in groups with an equal number of events in each group is not applicable to all input data sets. For this reason, a universal approach to all possible groupings of events in commensurate in size groups is proposed here. Also, an implementation of an algorithm base...

  11. Personality traits and group-based information behaviour

    DEFF Research Database (Denmark)

    Hyldegård, Jette

    2009-01-01

    Introduction. The relationship between hypothesised behaviour resulting from a personality test and actual information behaviour resulting from a group-based assignment process is addressed in this paper. Methods. Three voluntary groups of ten librarianship and information science students were....... Information behaviour associated with personality traits was identified, but the presence of personality effects tended to vary with the perceived presence of the social context. Conclusions. Some matches were identified between group members' personality traits and their actual information behaviour...

  12. An Event Grouping Based Algorithm for University Course Timetabling Problem

    OpenAIRE

    Kralev, Velin; Kraleva, Radoslava; Yurukov, Borislav

    2016-01-01

    This paper presents the study of an event grouping based algorithm for a university course timetabling problem. Several publications which discuss the problem and some approaches for its solution are analyzed. The grouping of events in groups with an equal number of events in each group is not applicable to all input data sets. For this reason, a universal approach to all possible groupings of events in commensurate in size groups is proposed here. Also, an implementation of an algorithm base...

  13. OPTIMAL TRAJECTORY PLANNING OF MANIPULATORS: A REVIEW

    Directory of Open Access Journals (Sweden)

    ATEF A. ATA

    2007-04-01

    Full Text Available Optimal motion planning is very important to the operation of robot manipulators. Its main target is the generation of a trajectory from start to goal that satisfies objectives, such as minimizing path traveling distance or time interval, lowest energy consumption or obstacle avoidance and satisfying the robot’s kinematics and dynamics. Review, discussion and analysis of optimization techniques to find the optimal trajectory either in Cartesian space or joint space are presented and investigated. Optimal trajectory selection approaches such as kinematics and dynamics techniques with various constraints are presented and explained. Although the kinematics approach is simple and straight forward, it will experience some problems in implementation because of lack of Inertia and torque constraints. The application of Genetic Algorithms to find the optimal trajectory of manipulators especially in the obstacle avoidance is also highlighted. Combining the Genetic Algorithms with other classical optimization methods proves to have better performance as a hybrid optimization technique.

  14. Moon Landing Trajectory Optimization

    Directory of Open Access Journals (Sweden)

    Ibrahim Mustafa MEHEDI

    2016-03-01

    Full Text Available Trajectory optimization is a crucial process during the planning phase of a spacecraft landing mission. Once a trajectory is determined, guidance algorithms are created to guide the vehicle along the given trajectory. Because fuel mass is a major driver of the total vehicle mass, and thus mission cost, the objective of most guidance algorithms is to minimize the required fuel consumption. Most of the existing algorithms are termed as “near-optimal” regarding fuel expenditure. The question arises as to how close to optimal are these guidance algorithms. To answer this question, numerical trajectory optimization techniques are often required. With the emergence of improved processing power and the application of new methods, more direct approaches may be employed to achieve high accuracy without the associated difficulties in computation or pre-existing knowledge of the solution. An example of such an approach is DIDO optimization. This technique is applied in the current research to find these minimum fuel optimal trajectories.

  15. When are emotions related to group-based appraisals? A comparison between group-based emotions and general group emotions.

    Science.gov (United States)

    Kuppens, Toon; Yzerbyt, Vincent Y

    2014-12-01

    In the literature on emotions in intergroup relations, it is not always clear how exactly emotions are group-related. Here, we distinguish between emotions that involve appraisals of immediate group concerns (i.e., group-based emotions) and emotions that do not. Recently, general group emotions, measured by asking people how they feel "as a group member" but without specifying an object for these emotions, have been conceptualized as reflecting appraisals of group concerns. In contrast, we propose that general group emotions are best seen as emotions about belonging to a group. In two studies, general group emotions were closely related to emotions that are explicitly measured as belonging emotions. Two further studies showed that general group emotions were not related to appraisals of immediate group concerns, whereas group-based emotions were. We argue for more specificity regarding the group-level aspects of emotion that are tapped by emotion measures.

  16. Prosocial Behavior: Long-Term Trajectories and Psychosocial Outcomes.

    Science.gov (United States)

    Flynn, Elinor; Ehrenreich, Samuel E; Beron, Kurt J; Underwood, Marion K

    2015-08-01

    This study investigated developmental trajectories for prosocial behavior for a sample followed from age 10 - 18 and examined possible adjustment outcomes associated with membership in different trajectory groups. Participants were 136 boys and 148 girls, their teachers, and their parents (19.4% African American, 2.4% Asian, 51.9% Caucasian, 19.5% Hispanic, and 5.8% other). Teachers rated children's prosocial behavior yearly in grades 4 - 12. At the end of the 12(th) grade year, teachers, parents, and participants reported externalizing behaviors and participants reported internalizing symptoms, narcissism, and features of borderline personality disorder. Results suggested that prosocial behavior remained stable from middle childhood through late adolescence. Group-based mixture modeling revealed three prosocial trajectory groups: low (18.7%), medium (52.8%), and high (29.6%). Membership in the high prosocial trajectory group predicted lower levels of externalizing behavior as compared to the low prosocial trajectory group, and for girls, lower levels of internalizing symptoms. Membership in the medium prosocial trajectory group also predicted being lower on externalizing behaviors. Membership in the high prosocial trajectory group predicted lower levels of borderline personality features for girls only.

  17. Job satisfaction developmental trajectories and health: A life course perspective.

    Science.gov (United States)

    Dirlam, Jonathan; Zheng, Hui

    2017-04-01

    Understanding the health consequence of job dissatisfaction becomes increasingly important because job insecurity, stress and dissatisfaction have significantly increased in the United States in the last decade. Despite the extensive work in this area, prior studies nonetheless may underestimate the harmful effect of job dissatisfaction due to the cross-sectional nature of their data and sample selection bias. This study applies a life-course approach to more comprehensively examine the relationship between job satisfaction and health. Using data from the NLSY 1979 cohort, we estimate group based job satisfaction trajectories of respondents starting at age 25 and ending at age 39. Four job satisfaction trajectory groups are identified, a consistently high satisfaction group, a downward group, an upward group, and a lowest satisfaction group. We examine the effects of these trajectories on several physical and mental health outcomes of respondents in their early forties. We find membership in the lowest job satisfaction trajectory group to be negatively associated with all five mental health outcomes, supporting the accumulation of risks life course model. Those in the upward job satisfaction trajectory group have similar health outcomes to those in the high job satisfaction trajectory group, supporting the social mobility life course model. Overall, we find the relationship between job satisfaction trajectories and health to be stronger for mental health compared to physical health. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Wordom: a user-friendly program for the analysis of molecular structures, trajectories, and free energy surfaces.

    Science.gov (United States)

    Seeber, Michele; Felline, Angelo; Raimondi, Francesco; Muff, Stefanie; Friedman, Ran; Rao, Francesco; Caflisch, Amedeo; Fanelli, Francesca

    2011-04-30

    Wordom is a versatile, user-friendly, and efficient program for manipulation and analysis of molecular structures and dynamics. The following new analysis modules have been added since the publication of the original Wordom paper in 2007: assignment of secondary structure, calculation of solvent accessible surfaces, elastic network model, motion cross correlations, protein structure network, shortest intra-molecular and inter-molecular communication paths, kinetic grouping analysis, and calculation of mincut-based free energy profiles. In addition, an interface with the Python scripting language has been built and the overall performance and user accessibility enhanced. The source code of Wordom (in the C programming language) as well as documentation for usage and further development are available as an open source package under the GNU General Purpose License from http://wordom.sf.net.

  19. A Topical Trajectory on Survival: An Analysis of Link-Making in a Sequence of Lessons on Evolution

    Science.gov (United States)

    Rocksén, Miranda; Olander, Clas

    2017-01-01

    This study explores the concept of link-making in relation to communicative strategies applied in the teaching and studying of biological evolution. The analysis focused on video recordings of 11 lessons on biological evolution conducted in a Swedish 9th grade class of students aged 15 years. It reveals how the teacher and students connected…

  20. Self-Esteem Trajectories among Ethnic Minority Adolescents: A Growth Curve Analysis of the Patterns and Predictors of Change

    Science.gov (United States)

    Greene, Melissa L.; Way, Niobe

    2005-01-01

    The current study presents a growth curve analysis of self-esteem among Black, Latino, and Asian American high school students. A series of hierarchical linear models were used to examine patterns and predictors of change in self-esteem over time. Results revealed an average increase in self-esteem with age. Although boys and girls experienced…

  1. Self-Esteem Trajectories among Ethnic Minority Adolescents: A Growth Curve Analysis of the Patterns and Predictors of Change

    Science.gov (United States)

    Greene, Melissa L.; Way, Niobe

    2005-01-01

    The current study presents a growth curve analysis of self-esteem among Black, Latino, and Asian American high school students. A series of hierarchical linear models were used to examine patterns and predictors of change in self-esteem over time. Results revealed an average increase in self-esteem with age. Although boys and girls experienced…

  2. Mean Square Displacement Analysis of Single-Particle Trajectories with Localization Error: Brownian Motion in Isotropic Medium

    OpenAIRE

    Michalet, Xavier

    2010-01-01

    We examine the capability of mean square displacement analysis to extract reliable values of the diffusion coefficient D of single particle undergoing Brownian motion in an isotropic medium in the presence of localization uncertainty. The theoretical results, supported by simulations, show that a simple unweighted least square fit of the MSD curve can provide the best estimate of D provided an optimal number of MSD points is used for the fit. We discuss the practical implications of these res...

  3. Trajectory grouping structure

    Directory of Open Access Journals (Sweden)

    Maike Buchin

    2015-03-01

    Full Text Available The collective motion of a set of moving entities like people, birds, or other animals, is characterized by groups arising, merging, splitting, and ending. Given the trajectories of these entities, we define and model a structure that captures all of such changes using the Reeb graph, a concept from topology. The trajectory grouping structure has three natural parameters that allow more global views of the data in group size, group duration, and entity inter-distance. We prove complexity bounds on the maximum number of maximal groups that can be present, and give algorithms to compute the grouping structure efficiently. We also study how the trajectory grouping structure can be made robust, that is, how brief interruptions of groups can be disregarded in the global structure, adding a notion of persistence to the structure. Furthermore, we showcase the results of experiments using data generated by the NetLogo flocking model and from the Starkey project. The Starkey data describe the movement of elk, deer, and cattle. Although there is no ground truth for the grouping structure in this data, the experiments show that the trajectory grouping structure is plausible and has the desired effects when changing the essential parameters. Our research provides the first complete study of trajectory group evolvement, including combinatorial,algorithmic, and experimental results.

  4. [The effect of group-based psychodrama therapy on decreasing the level of aggression in adolescents].

    Science.gov (United States)

    Karataş, Zeynep; Gökçakan, Dan Zafer

    2009-01-01

    This study aimed to examine the effect of group-based psychodrama therapy on the level aggression in adolescents. The study included 23 students from Nezihe Yalvac Anatolian Vocational High School of Hotel Management and Tourism that had high aggression scores. Eleven of the participants (6 female, 5 male) constituted the experimental group and 12 (6 male, 6 female) were in the control group. The 34-item Aggression Scale was used to measure level of aggression. We utilized mixed pattern design including experiment-control, pre-test and post test and follow up. The experimental group participated in group-based psychodrama therapy once a week for 90 minutes, for 14 weeks in total. The Aggression Scale was administered to the experimental and control groups before and after treatment; it was additionally administered to the experimental group 16 weeks after treatment. Data were analyzed using ANCOVA and dependent samples t tests. Our analysis shows that group-based psychodrama had an effect on the experimental group in terms of total aggression, anger, hostility, and indirect aggression scores (F=65.109, F=20.175, F=18.593, F=40.987, respectively, P<.001). There was no effect of the group-based treatment on verbal or physical aggression scores. Follow-up indicated that the effect of the therapy was still measureable 16 weeks after the cessation of the therapy. Results of the present study indicate that group-based psychodrama therapy decreased the level of aggression in the experimental group. Current findings are discussed with reference to the literature. Recommendations for further research and for psychiatric counselors are provided.

  5. Clustering vessel trajectories with alignment kernels under trajectory compression

    NARCIS (Netherlands)

    de Vries, G.; van Someren, M.

    2010-01-01

    In this paper we apply a selection of alignment measures, such as dynamic time warping and edit distance, to the problem of clustering vessel trajectories. Vessel trajectories are an example of moving object trajectories, which have recently become an important research topic. The alignment measures

  6. Finding human promoter groups based on DNA physical properties

    Science.gov (United States)

    Zeng, Jia; Cao, Xiao-Qin; Zhao, Hongya; Yan, Hong

    2009-10-01

    DNA rigidity is an important physical property originating from the DNA three-dimensional structure. Although the general DNA rigidity patterns in human promoters have been investigated, their distinct roles in transcription are largely unknown. In this paper, we discover four highly distinct human promoter groups based on similarity of their rigidity profiles. First, we find that all promoter groups conserve relatively rigid DNAs at the canonical TATA box [a consensus TATA(A/T)A(A/T) sequence] position, which are important physical signals in binding transcription factors. Second, we find that the genes activated by each group of promoters share significant biological functions based on their gene ontology annotations. Finally, we find that these human promoter groups correlate with the tissue-specific gene expression.

  7. Finding human promoter groups based on DNA physical properties.

    Science.gov (United States)

    Zeng, Jia; Cao, Xiao-Qin; Zhao, Hongya; Yan, Hong

    2009-10-01

    DNA rigidity is an important physical property originating from the DNA three-dimensional structure. Although the general DNA rigidity patterns in human promoters have been investigated, their distinct roles in transcription are largely unknown. In this paper, we discover four highly distinct human promoter groups based on similarity of their rigidity profiles. First, we find that all promoter groups conserve relatively rigid DNAs at the canonical TATA box [a consensus TATA(A/T)A(A/T) sequence] position, which are important physical signals in binding transcription factors. Second, we find that the genes activated by each group of promoters share significant biological functions based on their gene ontology annotations. Finally, we find that these human promoter groups correlate with the tissue-specific gene expression.

  8. Dissipative Bohmian mechanics within the Caldirola–Kanai framework: A trajectory analysis of wave-packet dynamics in viscid media

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, A.S., E-mail: asanz@iff.csic.es [Instituto de Física Fundamental (IFF-CSIC), Serrano 123, 28006 Madrid (Spain); Martínez-Casado, R. [Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ (United Kingdom); Peñate-Rodríguez, H.C.; Rojas-Lorenzo, G. [Instituto Superior de Tecnologías y Ciencias Aplicadas, Ave. Salvador Allende y Luaces, Quinta de Los Molinos, Plaza, La Habana 10600 (Cuba); Miret-Artés, S. [Instituto de Física Fundamental (IFF-CSIC), Serrano 123, 28006 Madrid (Spain)

    2014-08-15

    Classical viscid media are quite common in our everyday life. However, we are not used to find such media in quantum mechanics, and much less to analyze their effects on the dynamics of quantum systems. In this regard, the Caldirola–Kanai time-dependent Hamiltonian constitutes an appealing model, accounting for friction without including environmental fluctuations (as it happens, for example, with quantum Brownian motion). Here, a Bohmian analysis of the associated friction dynamics is provided in order to understand how a hypothetical, purely quantum viscid medium would act on a wave packet from a (quantum) hydrodynamic viewpoint. To this purpose, a series of paradigmatic contexts have been chosen, such as the free particle, the motion under the action of a linear potential, the harmonic oscillator, or the superposition of two coherent wave packets. Apart from their analyticity, these examples illustrate interesting emerging behaviors, such as localization by “quantum freezing” or a particular type of quantum–classical correspondence. The reliability of the results analytically determined has been checked by means of numerical simulations, which has served to investigate other problems lacking of such analyticity (e.g., the coherent superpositions). - Highlights: • A dissipative Bohmian approach is developed within the Caldirola–Kanai model. • Some simple yet physically insightful systems are then studied analytically. • Dissipation leads to spatial localization in free-force regimes. • Under the action of linear forces, dissipation leads to uniform motion. • In harmonic potentials, the system decays unavoidable to the well minimum.

  9. Semantic enrichment of GPS trajectories

    NARCIS (Netherlands)

    Graaff, de Victor; Keulen, van Maurice; By, de Rolf

    2012-01-01

    Semantic annotation of GPS trajectories helps us to recognize the interests of the creator of the GPS trajectories. Automating this trajectory annotation circumvents the requirement of additional user input. To annotate the GPS traces automatically, two types of automated input are required: 1) a co

  10. Growth Trajectories of Health Behaviors from Adolescence through Young Adulthood

    Directory of Open Access Journals (Sweden)

    Nora Wiium

    2015-10-01

    Full Text Available Based on nine waves of data collected during a period of 17 years (1990–2007, the present study explored different developmental trajectories of the following unhealthy behaviors: regular smoking, lack of regular exercise, lack of daily fruit intake, and drunkenness. A baseline sample of 1195 13-year-old pupils was from 22 randomly selected schools in the Hordaland County in western Norway. Latent class growth analysis revealed three developmental trajectories. The first trajectory was a conventional trajectory, comprising 36.3% of participants, who showed changes in smoking, physical exercise, fruit intake, and drunkenness consistent with the prevailing age specific norms of these behaviors in the Norwegian society at the time. The second trajectory was a passive trajectory, comprising 25.5% of participants, who reported low levels of both healthy and unhealthy behaviors during the 17-year period. The third trajectory was an unhealthy trajectory, comprising 38.2% of participants, who had high levels of unhealthy behaviors over time. Several covariates were examined, but only sex and mother’s and father’s educational levels were found to be significantly associated with the identified trajectories. While these findings need to be replicated in future studies, the identification of the different trajectories suggests the need to tailor intervention according to specific needs.

  11. Thoracostomy tube function not trajectory dictates reintervention.

    Science.gov (United States)

    Kugler, Nathan W; Carver, Thomas W; Knechtges, Paul; Milia, David; Goodman, Lawrence; Paul, Jasmeet S

    2016-12-01

    Hemothorax and/or pneumothorax can be managed successfully managed with tube thoracostomy (TT) in the majority of cases. Improperly placed tubes are common with rates near 30%. This study aimed to determine whether TT trajectory affects the rate of secondary intervention. A retrospective review of all adult trauma patients undergoing TT placement over a 4-y period was performed. TT trajectory was classified as ideal, nonideal, or kinked-based on anterior-posterior chest x-ray. TTs with sentinel port outside the thoracic cavity were excluded. The primary outcome was any secondary intervention. Four-hundred eighty-six patients and a total of 547 hemithoraces underwent placement and met inclusion criteria. The majority of patients were male (76%), with a median age of 41 y, and majority suffered blunt trauma ideal trajectory was identified in 429 (78.4%). Kinked TTs were noted in 33 (6%) hemothoraces with a 45.5% replacement rate. Review with staff demonstrates inherent bias to replace kinked TTs. The overall secondary intervention rate was 27.8%. Kinked TTs were removed from final analysis due to treatment bias. Subsequent analysis demonstrated no significant difference between ideal and nonideal trajectories (25.1% versus 34.1%, P = 0.09). Intrathoracic trajectory of nonkinked TTs with the sentinel port within the thoracic cavity does not affect secondary intervention rates, including the rate of surgical intervention. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Interference, Reduced Action, and Trajectories

    Science.gov (United States)

    Floyd, Edward R.

    2007-09-01

    Instead of investigating the interference between two stationary, rectilinear wave functions in a trajectory representation by examining the trajectories of the two rectilinear wave functions individually, we examine a dichromatic wave function that is synthesized from the two interfering wave functions. The physics of interference is contained in the reduced action for the dichromatic wave function. As this reduced action is a generator of the motion for the dichromatic wave function, it determines the dichromatic wave function’s trajectory. The quantum effective mass renders insight into the behavior of the trajectory. The trajectory in turn renders insight into quantum nonlocality.

  13. Trajectories of Marital Conflict Across the Life Course: Predictors and Interactions With Marital Happiness Trajectories.

    Science.gov (United States)

    Kamp Dush, Claire M; Taylor, Miles G

    2012-03-01

    Using typologies outlined by Gottman and Fitzpatrick as well as institutional and companionate models of marriage, the authors conducted a latent class analysis of marital conflict trajectories using 20 years of data from the Marital Instability Over the Life Course study. Respondents were in one of three groups: high, medium (around the mean), or low conflict. Several factors predicted conflict trajectory group membership; respondents who believed in lifelong marriage and shared decisions equally with their spouse were more likely to report low and less likely to report high conflict. The conflict trajectories were intersected with marital happiness trajectories to examine predictors of high and low quality marriages. A stronger belief in lifelong marriage, shared decision making, and husbands sharing a greater proportion of housework were associated with an increased likelihood of membership in a high happiness, low conflict marriage, and a decreased likelihood of a low marital happiness group.

  14. A Trajectory UML profile For Modeling Trajectory Data: A Mobile Hospital Use Case

    CERN Document Server

    Oueslati, Wided

    2011-01-01

    A large amount of data resulting from trajectories of moving objects activities are collected thanks to localization based services and some associated automated processes. Trajectories data can be used either for transactional and analysis purposes in various domains (heath care, commerce, environment, etc.). For this reason, modeling trajectory data at the conceptual level is an important stair leading to global vision and successful implementations. However, current modeling tools fail to fulfill specific moving objects activities requirements. In this paper, we propose a new profile based on UML in order to enhance the conceptual modeling of trajectory data related to mobile objects by new stereotypes and icons. As illustration, we present a mobile hospital use case.

  15. Dynamics Analysis of a Three-DOF Planar Serial-Parallel Mechanism for Active Dynamic Balancing with Respect to a Given Trajectory

    Directory of Open Access Journals (Sweden)

    Kun Wang

    2013-01-01

    Full Text Available The concept of dynamic balancing with respect to a given trajectory is proposed in this paper. Trajectory-based dynamic balancing is a technique that brings additional mechanisms to unbalanced mechanisms with the purpose of actuating the original mechanism to move along a predefined trajectory, regardless of the shaking forces and moments. In this work, a planar three degrees of freedom (3-DOF serial-parallel mechanism is proposed to implement this technique on an unbalanced platform. The overall structure of the system is firstly introduced and the mechanical design and kinematics of the proposed mechanism is then presented. The dynamic model of the mechanism and the platform is derived and analysed. Finally, numerical examples are presented to verify the effectiveness of the active dynamic balancing mechanism and the improved dynamic performance of the system.

  16. The gap between entitlement and access to healthcare: An analysis of "candidacy" in the help-seeking trajectories of asylum seekers in Montreal.

    Science.gov (United States)

    Chase, Liana E; Cleveland, Janet; Beatson, Jesse; Rousseau, Cécile

    2017-06-01

    In 2012 the Canadian government made significant cuts to its historically strong federal refugee health coverage plan. While this policy had negligible effects on the level of coverage provided to asylum seekers in Quebec, there is evidence that this group nonetheless experienced reduced healthcare access during the period of polarized national debate that ensued. This study engaged the "candidacy" model of healthcare access to illuminate factors contributing to the observed gap between entitlement and access. Twenty-five semi-structured interviews were conducted with asylum seekers in Montreal to elicit narrative accounts of difficulties encountered in the pursuit of healthcare. Thematic content analysis in conjunction with a holistic examination of help-seeking trajectories revealed several important barriers to obtaining care, including widespread confusion and misinformation about refugee health coverage, cumbersome administrative procedures specific to asylum seekers, and long wait times. Feelings of marginalization and insecurity associated with precarious migratory status appeared to amplify the effects of these barriers to care such that even a minor access difficulty could have dramatic effects on future help-seeking and access outcomes. Demonstrating awareness of public discourses interrogating their deservingness of health coverage, participants often interpreted access difficulties as evidence of health professionals' unwillingness to serve them. Such interpretations conspired with fears associated with the asylum claim process to suppress self-advocacy, further help-seeking, and at times even information-seeking. This finding is particularly significant in that it suggests a mechanism through which hostile public representations of forced migrants-increasingly prevalent in Western host countries-can themselves endanger the physical, psychological, and social health of highly disadvantaged populations, even in the presence of strong entitlement policies

  17. Group-based sparse representation for image restoration.

    Science.gov (United States)

    Zhang, Jian; Zhao, Debin; Gao, Wen

    2014-08-01

    Traditional patch-based sparse representation modeling of natural images usually suffer from two problems. First, it has to solve a large-scale optimization problem with high computational complexity in dictionary learning. Second, each patch is considered independently in dictionary learning and sparse coding, which ignores the relationship among patches, resulting in inaccurate sparse coding coefficients. In this paper, instead of using patch as the basic unit of sparse representation, we exploit the concept of group as the basic unit of sparse representation, which is composed of nonlocal patches with similar structures, and establish a novel sparse representation modeling of natural images, called group-based sparse representation (GSR). The proposed GSR is able to sparsely represent natural images in the domain of group, which enforces the intrinsic local sparsity and nonlocal self-similarity of images simultaneously in a unified framework. In addition, an effective self-adaptive dictionary learning method for each group with low complexity is designed, rather than dictionary learning from natural images. To make GSR tractable and robust, a split Bregman-based technique is developed to solve the proposed GSR-driven ℓ0 minimization problem for image restoration efficiently. Extensive experiments on image inpainting, image deblurring and image compressive sensing recovery manifest that the proposed GSR modeling outperforms many current state-of-the-art schemes in both peak signal-to-noise ratio and visual perception.

  18. Hardware Accelerators Targeting a Novel Group Based Packet Classification Algorithm

    Directory of Open Access Journals (Sweden)

    O. Ahmed

    2013-01-01

    Full Text Available Packet classification is a ubiquitous and key building block for many critical network devices. However, it remains as one of the main bottlenecks faced when designing fast network devices. In this paper, we propose a novel Group Based Search packet classification Algorithm (GBSA that is scalable, fast, and efficient. GBSA consumes an average of 0.4 megabytes of memory for a 10 k rule set. The worst-case classification time per packet is 2 microseconds, and the preprocessing speed is 3 M rules/second based on an Xeon processor operating at 3.4 GHz. When compared with other state-of-the-art classification techniques, the results showed that GBSA outperforms the competition with respect to speed, memory usage, and processing time. Moreover, GBSA is amenable to implementation in hardware. Three different hardware implementations are also presented in this paper including an Application Specific Instruction Set Processor (ASIP implementation and two pure Register-Transfer Level (RTL implementations based on Impulse-C and Handel-C flows, respectively. Speedups achieved with these hardware accelerators ranged from 9x to 18x compared with a pure software implementation running on an Xeon processor.

  19. Efficient One-click Browsing of Large Trajectory Sets

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Lewis-Kelham, Edwin

    2014-01-01

    Traffic researchers, planners, and analysts want a simple way to query the large quantities of GPS trajectories collected from vehicles. In addition, users expect the results to be presented immediately even when querying very large transportation networks with huge trajectory data sets. This paper...... presents a novel query type called sheaf, where users can browse trajectory data sets using a single mouse click. Sheaves are very versatile and can be used for location-based advertising, travel-time analysis, intersection analysis, and reachability analysis (isochrones). A novel in-memory trajectory...... index compresses the data by a factor of 12.4 and enables execution of sheaf queries in 40 ms. This is up to 2 orders of magnitude faster than existing work. We demonstrate the simplicity, versatility, and efficiency of sheaf queries using a real-world trajectory set consisting of 2.7 million...

  20. Test particle trajectories near cosmic strings

    Indian Academy of Sciences (India)

    Farook Rahaman; Subenoy Chakraborty; K Maity

    2002-01-01

    We present a detailed analysis of the motion of test particle in the gravitational field of cosmic strings in different situations using the Hamilton–Jacobi (H–J) formalism. We have discussed the trajectories near static cosmic string, cosmic string in Brans–Dicke theory and cosmic string in dilaton gravity.

  1. Romantic attraction and adolescent smoking trajectories.

    Science.gov (United States)

    Pollard, Michael S; Tucker, Joan S; Green, Harold D; Kennedy, David P; Go, Myong-Hyun

    2011-12-01

    Research on sexual orientation and substance use has established that lesbian, gay, and bisexual (LGB) individuals are more likely to smoke than heterosexuals. This analysis furthers the examination of smoking behaviors across sexual orientation groups by describing how same- and opposite-sex romantic attraction, and changes in romantic attraction, are associated with distinct six-year developmental trajectories of smoking. The National Longitudinal Study of Adolescent Health dataset is used to test our hypotheses. Multinomial logistic regressions predicting smoking trajectory membership as a function of romantic attraction were separately estimated for men and women. Romantic attraction effects were found only for women. The change from self-reported heterosexual attraction to lesbian or bisexual attraction was more predictive of higher smoking trajectories than was a consistent lesbian or bisexual attraction, with potentially important differences between the smoking patterns of these two groups.

  2. Trajectory Optimization: OTIS 4

    Science.gov (United States)

    Riehl, John P.; Sjauw, Waldy K.; Falck, Robert D.; Paris, Stephen W.

    2010-01-01

    The latest release of the Optimal Trajectories by Implicit Simulation (OTIS4) allows users to simulate and optimize aerospace vehicle trajectories. With OTIS4, one can seamlessly generate optimal trajectories and parametric vehicle designs simultaneously. New features also allow OTIS4 to solve non-aerospace continuous time optimal control problems. The inputs and outputs of OTIS4 have been updated extensively from previous versions. Inputs now make use of objectoriented constructs, including one called a metastring. Metastrings use a greatly improved calculator and common nomenclature to reduce the user s workload. They allow for more flexibility in specifying vehicle physical models, boundary conditions, and path constraints. The OTIS4 calculator supports common mathematical functions, Boolean operations, and conditional statements. This allows users to define their own variables for use as outputs, constraints, or objective functions. The user-defined outputs can directly interface with other programs, such as spreadsheets, plotting packages, and visualization programs. Internally, OTIS4 has more explicit and implicit integration procedures, including high-order collocation methods, the pseudo-spectral method, and several variations of multiple shooting. Users may switch easily between the various methods. Several unique numerical techniques such as automated variable scaling and implicit integration grid refinement, support the integration methods. OTIS4 is also significantly more user friendly than previous versions. The installation process is nearly identical on various platforms, including Microsoft Windows, Apple OS X, and Linux operating systems. Cross-platform scripts also help make the execution of OTIS and post-processing of data easier. OTIS4 is supplied free by NASA and is subject to ITAR (International Traffic in Arms Regulations) restrictions. Users must have a Fortran compiler, and a Python interpreter is highly recommended.

  3. Going Ballistic: Bullet Trajectories

    Directory of Open Access Journals (Sweden)

    Amanda Wade

    2011-01-01

    Full Text Available This project seeks to answer at what angle does a gun marksman have to aim in order to hit the center of a target one meter off the ground and 1000 meters away? We begin by modeling the bullet's trajectory using Euler's method with the help of a Microsoft Excel spreadsheet solver, and then systematically search for the angle corresponding to the center of the target. It was found that a marksman shooting a target 1000 meters away and 1 meter off the ground has to aim the rifle 0.436° above horizontal to hit the center.

  4. Posttraumatic Stress Symptoms and Trajectories in Child Sexual Abuse Victims: An Analysis of Sex Differences Using the National Survey of Child and Adolescent Well-Being

    Science.gov (United States)

    Maikovich, Andrea Kohn; Koenen, Karestan C.; Jaffee, Sara R.

    2009-01-01

    Very few studies have prospectively examined sex differences in posttraumatic stress symptoms and symptom trajectories in youth victimized by childhood sexual abuse. This study addresses that question in a relatively large sample of children, drawn from the National Survey of Child and Adolescent Well-Being, who were between the ages of 8-16 years…

  5. Trajectories in parallel optics.

    Science.gov (United States)

    Klapp, Iftach; Sochen, Nir; Mendlovic, David

    2011-10-01

    In our previous work we showed the ability to improve the optical system's matrix condition by optical design, thereby improving its robustness to noise. It was shown that by using singular value decomposition, a target point-spread function (PSF) matrix can be defined for an auxiliary optical system, which works parallel to the original system to achieve such an improvement. In this paper, after briefly introducing the all optics implementation of the auxiliary system, we show a method to decompose the target PSF matrix. This is done through a series of shifted responses of auxiliary optics (named trajectories), where a complicated hardware filter is replaced by postprocessing. This process manipulates the pixel confined PSF response of simple auxiliary optics, which in turn creates an auxiliary system with the required PSF matrix. This method is simulated on two space variant systems and reduces their system condition number from 18,598 to 197 and from 87,640 to 5.75, respectively. We perform a study of the latter result and show significant improvement in image restoration performance, in comparison to a system without auxiliary optics and to other previously suggested hybrid solutions. Image restoration results show that in a range of low signal-to-noise ratio values, the trajectories method gives a significant advantage over alternative approaches. A third space invariant study case is explored only briefly, and we present a significant improvement in the matrix condition number from 1.9160e+013 to 34,526.

  6. REVERSE DESIGN APPROACH FOR MECHANISM TRAJECTORY BASED ON CODE-CHAINS MATCHING

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shuyou; YI Guodong; XU Xiaofeng

    2007-01-01

    Aiming at the problem of reverse-design of mechanism, a method based on the matching of trajectory code-chains is presented. The motion trajectory of mechanism is described with code-chain,which is normalized to simplify the operation of geometric transformation. The geometric transformation formulas of scale, mirror and rotation for trajectory code-chain are defined, and the reverse design for mechanism trajectory is realized through the analysis and solution of similarity matching between the desired trajectory and the predefined trajectory. The algorithm program and prototype system of reverse design for mechanism trajectory are developed. Application samples show that the method can break the restriction of trajectory patterns in matching, meet the demand of partial matching, and overcome the influence of geometric transformation of trajectory on the reverse design for mechanism.

  7. Simulation Study on Fuzzy Control of Rotary Steering Drilling Trajectory

    Directory of Open Access Journals (Sweden)

    Xue Qi-Long

    2012-07-01

    Full Text Available The purpose of this study is to establish a control method to make borehole trajectory smoother. Considering that the complexity of rotary steerable drilling trajectory control and uncertainty of underground work, analysis of the deficiencies for the traditional trajectory control and the rotary steerable drilling trajectory deviation vector control theory, introduced the concept of "trend Angle", combined with the deviation vector as joint control variables, using fuzzy control algorithm that established of rotary steerable drilling trajectory fuzzy control model. Designed the fuzzy controller using Matlab/Simulink toolbox and dynamic simulation analysis for the fuzzy control systems, simulation results show that the designed fuzzy controller can effectively track the well path design, has a strong adaptability and control results is better than traditional PID control method.

  8. 基于不确定性分析的自主导航轨迹评测方法%Autonomous Navigation Trajectory Evaluation Method Based on Uncertainty Analysis

    Institute of Scientific and Technical Information of China (English)

    阎岩; 唐振民; 刘家银

    2013-01-01

    为满足自主导航轨迹定性和定量评测要求,提出一种基于不确定性云模型的轨迹分析计算方法.该方法通过提取机器人自主行驶和避障行为中的运动轨迹特征,建立对应的方位偏离、方向偏差和避障安全距离轨迹特征云模型,以云模型的期望作为轨迹特征基本度量,以熵和超熵表达特征所具有的模糊性和随机性.利用云模型所具有的不确定性度量优势,反映系统自主导航过程中的瞬时状态和系统稳定性.实验结果表明,该方法能够有效评估自主导航系统轨迹数据,并能够弥补基于增强学习的方法无法直观反映系统评价稳定性的不足.%In order to achieve qualitative and quantitative evaluation of autonomous navigation trajectory, a trajectory analysis method based on uncertainty cloud model is proposed. In this method, robot's trajectory features are extracted from autonomous driving and avoiding actions, and corresponding feature cloud models for position warp, direction warp and obstacle-avoidance safety distance trajectories are generated. In cloud model, expectation is the basic metric of trajectories, and the fuzziness and randomness of features are expressed by entropy and hyper-entropy. By taking advantages of uncertainty metric of cloud models, the transient state and stability in autonomous navigation can be calculated. Experiment results show that this method can effectively be used in trajectory evaluation of autonomous navigation, and it can compensate shortcomings of reinforcement learning methods in stability evaluation.

  9. Periodic billiard trajectories in polygons: generating mechanisms

    Science.gov (United States)

    Vorobets, Ya B.; Gal'perin, G. A.; Stepin, Anatolii M.

    1992-06-01

    CONTENTSIntroduction §1. Billiard trajectories in a plane domain §2. Fagnano's problem. Mechanical interpretations of periodic trajectories in triangles §3. An extremal property of billiard trajectories. Birkhoff's theorem. The non-existence of a unified construction of periodic trajectories in obtuse triangles §4. 'Perpendicular' trajectories in obtuse triangles of special shape §5. 'Perpendicular' trajectories in rational polygons and polyhedra §6. Stable trajectories §7. Stable perpendicular trajectories §8. Isolated trajectories §9. Isolated trajectories in acute and obtuse triangles. The bifurcation diagram of isolated trajectories (a 'hang-glider' configuration) §10. The density of F-triangles in a neighbourhood of (0, 0) §11. Generalization of the construction of isolated trajectories in obtuse triangles §12. Stable and unstable billiard trajectories in plane Weyl chambers §13. A criterion for the stability of periodic trajectories in a regular hexagonConclusionReferences

  10. Interference, reduced action, and trajectories

    CERN Document Server

    Floyd, E R

    2006-01-01

    Instead of investigating the interference between two stationary, rectilinear wave functions in a trajectory representation by examining the two rectilinear wave functions individually, we examine a dichromatic wave function that is synthesized from the two interfering wave functions. The physics of interference is contained in the reduced action for the dichromatic wave function. As this reduced action is a generator of the motion for the dichromatic wave function, it determines the dichromatic wave function's trajectory. The quantum effective mass renders insight into the behavior of the trajectory. The trajectory in turn renders insight into quantum nonlocality.

  11. Stratospheric ozone loss in the 1996/1997 Arctic winter: Evaluation based on multiple trajectory analysis for double-sounded air parcels by ILAS

    Science.gov (United States)

    Terao, Yukio; Sasano, Yasuhiro; Nakajima, Hideaki; Tanaka, H. L.; Yasunari, Tetsuzo

    2002-12-01

    Quantitative chemical ozone loss rates and amounts in the Arctic polar vortex for the spring of 1997 are analyzed based on ozone profile data obtained by the Improved Limb Atmospheric Spectrometer (ILAS) using an extension of the Match technique. In this study, we calculated additional multiple trajectories and set very strict criteria to overcome the weakness of the satellite sensor data (lower vertical resolution and larger sampling air mass volume) and to identify more accurately a double-sounded air mass. On the average inside the inner edge of the vortex boundary (north of about 70°N equivalent latitude), the local ozone loss rate was 50-80 ppbv/day at the maximum during late February between the levels of 450 and 500 K potential temperatures. The integrated ozone loss during February to March reached 2.0 ± 0.1 ppmv at 475-529 K levels, and the column ozone loss between 400 and 600 K during the 2 months was 96 ± 0.3 DU. Using a relative potential vorticity (rPV) scale, the vortex was divided into some rPV belts, and it was shown that the magnitude of the ozone loss increased gradually toward the vortex center from the edge. The maximum ozone loss rate of 6.0 ± 0.6 ppbv/sunlit hour near the vortex center was higher than near the vortex edge by a factor of 2-3. When we expanded the area of interest to include all the data obtained inside the vortex edge (north of about 65°N equivalent latitude), the local ozone loss rate was about 50 ppbv/day at the maximum. This value is slightly larger than that estimated by the Match analysis using ozonesondes for the same winter by ˜10 ppbv/day. Temperature histories of double-sounded air parcels indicated that the extreme ozone loss in the innermost part of the vortex was observed when the air parcel experienced temperatures below TNAT during the two soundings and had experienced temperatures near Tice in the 10 days prior to the first sounding. These facts suggest that the high ozone loss rate deep inside the vortex

  12. Trajectories of Learning : Embodied Interaction in Change

    OpenAIRE

    Melander, Helen

    2009-01-01

    This dissertation is about learning as changing understanding in social and situated activities. It takes part in the development of a reconceptualization of learning initiated within participationist perspectives. Multiparty interaction in situated activities is a primordial site for the exploration of human action and cognition. Through the theoretical framework of Conversation Analysis (CA), a method for the analysis and description of trajectories of learning is proposed. Departing from a...

  13. Predicting adherence trajectory using initial patterns of medication filling.

    Science.gov (United States)

    Franklin, Jessica M; Krumme, Alexis A; Shrank, William H; Matlin, Olga S; Brennan, Troyen A; Choudhry, Niteesh K

    2015-09-01

    To evaluate the ability of initial medication dispensings to predict long-term patterns of adherence. A retrospective cohort study of statin initiators enrolled in a Medicare Part D drug plan from CVS Caremark from 2005 to 2008. We used group-based trajectory models to classify patients into 6 adherence trajectories based on patterns of statin filling over the year following therapy initiation. Baseline clinical characteristics and indicators of statin filling during the first 2 to 4 months following initiation were used to predict adherence trajectory in logistic regression models, separately within strata of the days' supply of the initial statin dispensing. Cross-validation was used to measure predictive accuracy of models in data not used for model estimation. Among 77,703 statin initiators, prediction using baseline variables only was poor (cross-validated C statistic ≤ 0.61). When using 3 months of initial adherence to predict trajectory, prediction was greatly improved among patients with an index supply ≤30 days (0.62 ≤ C ≤ 0.91). With 4 months of initial adherence in the model, prediction was strong for all patients (C ≥ 0.72), especially for the best and worst trajectories (C = 0.90 and 0.94, respectively, in patients with an index supply ≤ 30 days; and C = 0.83 and 0.90, respectively, in patients with an index supply > 30 days). Initial filling behavior strongly predicted future adherence trajectory. Predicting adherence trajectories may facilitate better targeting of interventions to patients most likely to benefit.

  14. Intergroup Consensus/Disagreement in Support of Group-Based Hierarchy: An Examination of Socio-Structural and Psycho-Cultural Factors

    Science.gov (United States)

    Lee, I-Ching; Pratto, Felicia; Johnson, Blair T.

    2011-01-01

    A meta-analysis examined the extent to which socio-structural and psycho-cultural characteristics of societies correspond with how much gender and ethnic/racial groups differ on their support of group-based hierarchy. Robustly, women opposed group-based hierarchy more than men did, and members of lower power ethnic/racial groups opposed…

  15. Urban water trajectories

    CERN Document Server

    Allen, Adriana; Hofmann, Pascale; Teh, Tse-Hui

    2017-01-01

    Water is an essential element in the future of cities. It shapes cities’ locations, form, ecology, prosperity and health. The changing nature of urbanisation, climate change, water scarcity, environmental values, globalisation and social justice mean that the models of provision of water services and infrastructure that have dominated for the past two centuries are increasingly infeasible. Conventional arrangements for understanding and managing water in cities are being subverted by a range of natural, technological, political, economic and social changes. The prognosis for water in cities remains unclear, and multiple visions and discourses are emerging to fill the space left by the certainty of nineteenth century urban water planning and engineering. This book documents a sample of those different trajectories, in terms of water transformations, option, services and politics. Water is a key element shaping urban form, economies and lifestyles, part of the ongoing transformation of cities. Cities are face...

  16. [Critical trajectories of female victims of gender violence: discourse analysis of women and staff professionals in Porto Alegre, Rio Grande do Sul State, Brazil].

    Science.gov (United States)

    Meneghel, Stela Nazareth; Bairros, Fernanda; Mueller, Betânia; Monteiro, Débora; Oliveira, Lidiane Pellenz de; Collaziol, Marceli Emer

    2011-04-01

    This qualitative study aims to describe the trajectories of female victims of gender violence in Porto Alegre, Rio Grande do Sul State, Brazil. The methodology included in-depth interviews with women and staff, attempting to map the critical paths of women when they made the decision to seek professional help. We interviewed 21 women victims of gender violence and 25 professionals, including law enforcement officials, health and social workers, and nongovernmental organizations. The women's trajectories in the services were mapped, identifying facilitating factors and obstacles in the process of breaking with gender violence. The victims reported: pressure by professional staff to return to their marriages and police inefficiency in providing protection. The discourse of law enforcement officials and health and social workers showed a range of different concepts regarding violence, medicalization of violence, and network fragmentation.

  17. Dynamics Analysis of a Three-DOF Planar Serial-Parallel Mechanism for Active Dynamic Balancing with Respect to a Given Trajectory

    Directory of Open Access Journals (Sweden)

    Kun Wang

    2013-01-01

    Full Text Available The concept of dynamic balancing with respect to a given trajectory is proposed in this paper. Trajectory‐based dynamic balancing is a technique that brings additional mechanisms to unbalanced mechanisms with the purpose of actuating the original mechanism to move along a predefined trajectory, regardless of the shaking forces and moments. In this work, a planar three degrees of freedom (3‐DOF serial‐parallel mechanism is proposed to implement this technique on an unbalanced platform. The overall structure of the system is firstly introduced and the mechanical design and kinematics of the proposed mechanism is then presented. The dynamic model of the mechanism and the platform is derived and analysed. Finally, numerical examples are presented to verify the effectiveness of the active dynamic balancing mechanism and the improved dynamic performance of the system.

  18. Access, Coping and Relevance of Education at Local Level: A Case Study. A life course approach to the analysis of young people’s educational trajectories

    Directory of Open Access Journals (Sweden)

    Silvia Demozzi

    2016-07-01

    Full Text Available The present paper introduces the objectives and the design of the project “Governance of Educational Trajectories in Europe” (GOETE and it presents some findings emerging from a case study conducted in one of the cities involved in the project, Bologna. GOETE project analyzed how educational trajectories of children and young people between the end of primary education and the beginning of post-compulsory routes are regulated in eight different EU-member states: Finland, France, Germany, Italy, Netherlands, Poland, Slovenia and the UK. The research assesses the outcomes of education, taking into account the effects of social inequalities, changes in the governance of education in terms of lifelong learning, knowledge societies and transnational educational spaces. “Life course” perspective provides an interactive understanding of educational processes and addresses the interplay between the institutionalization of individual lives and subjective biographies.

  19. Trajectories of glycaemia, insulin sensitivity, and insulin secretion before diagnosis of type 2 diabetes: an analysis from the Whitehall II study

    DEFF Research Database (Denmark)

    Tabák, A.G.; Jokela, M.; Akbaraly, T.N.

    2009-01-01

    BACKGROUND: Little is known about the timing of changes in glucose metabolism before occurrence of type 2 diabetes. We aimed to characterise trajectories of fasting and postload glucose, insulin sensitivity, and insulin secretion in individuals who develop type 2 diabetes. METHODS: We analysed data...... from our prospective occupational cohort study (Whitehall II study) of 6538 (71% male and 91% white) British civil servants without diabetes mellitus at baseline. During a median follow-up period of 9.7 years, 505 diabetes cases were diagnosed (49.1% on the basis of oral glucose tolerance test). We...... assessed retrospective trajectories of fasting and 2-h postload glucose, homoeostasis model assessment (HOMA) insulin sensitivity, and HOMA beta-cell function from up to 13 years before diabetes diagnosis (diabetic group) or at the end of follow-up (non-diabetics). FINDINGS: Multilevel models adjusted...

  20. Organized Sport Trajectories from Childhood to Adolescence and Health Associations.

    Science.gov (United States)

    Howie, Erin K; McVeigh, Joanne A; Smith, Anne J; Straker, Leon M

    2016-07-01

    The purpose of this study was to identify unique organized sport trajectories from early childhood to late adolescence in an Australian pregnancy cohort, the Raine Study. Participation in organized sport was assessed at ages 5, 8, 10, 14, and 17 yr. Physical activity, body composition, and self-rated physical and mental health were assessed at the age of 20 yr. Latent class analysis was used to identify patterns of sport participation. To assess the internal validity of the trajectory classes, differences in health characteristics between trajectories were analyzed using generalized linear models. For girls, three trajectory classes were identified: consistent sport participators (47.5%), sport dropouts (34.3%), and sport nonparticipators (18.1%). For boys, three trajectory classes were identified: consistent sport participators (55.2%), sport dropouts (36.9%), and sport joiners (8.1%). For girls, there were overall differences across trajectory classes in lean body mass (P = 0.003), lean mass index (P = 0.06), and physical health (P = 0.004). For boys, there were differences across classes in physical activity (P = 0.018), percent body fat (P = 0.002), lean body mass (P health (P = 0.06), and depression scores (P = 0.27). This study identified unique, sex-specific trajectories of organized sport participation. The differences in health outcomes between trajectory classes, such as participants with consistent sport participation having more preferable health outcomes at the age of 20 yr, support the internal validity of the trajectories. Strategies are needed to identify and encourage those in the dropout trajectory to maintain their participation and those in the nonparticipator or joiner trajectories to join sport earlier. Specifically, interventions to encourage early sport participation in girls and help nonparticipating boys to join sport during adolescence may help more children receive the benefits of sport participation.

  1. Iso-chemical potential trajectories in the P-T plane for He II

    Science.gov (United States)

    Maytal, B.; Nissen, J. A.; Van Sciver, S. W.

    1990-01-01

    Trajectories of constant chemical potential in the P-T plane serve as an integral formulation of London's equation. The trajectories are useful for analysis and synthesis of fountain effect pump performance. A family of trajectories is generated from available numerical codes.

  2. Iso-chemical potential trajectories in the P-T plane for He II

    Science.gov (United States)

    Maytal, B.; Nissen, J. A.; Van Sciver, S. W.

    1990-01-01

    Trajectories of constant chemical potential in the P-T plane serve as an integral formulation of London's equation. The trajectories are useful for analysis and synthesis of fountain effect pump performance. A family of trajectories is generated from available numerical codes.

  3. Segmenting Trajectories by Movement States

    NARCIS (Netherlands)

    Buchin, M.; Kruckenberg, H.; Kölzsch, A.; Timpf, S.; Laube, P.

    2013-01-01

    Dividing movement trajectories according to different movement states of animals has become a challenge in movement ecology, as well as in algorithm development. In this study, we revisit and extend a framework for trajectory segmentation based on spatio-temporal criteria for this purpose. We adapt

  4. A user's guide for a generalized interplanetary trajectory generation program

    Science.gov (United States)

    1972-01-01

    The analysis, structure, and capability of a generalized precision interplanetary trajectory computation program are discussed, with emphasis being placed on the description of input and output. Sample cases showing input and output information are included.

  5. The Multiobjective Trajectory Optimization for Hypersonic Glide Vehicle Based on Normal Boundary Intersection Method

    OpenAIRE

    Zhengnan Li; Tao Yang; Zhiwei Feng

    2016-01-01

    To solve the multiobjective optimization problem on hypersonic glider vehicle trajectory design subjected to complex constraints, this paper proposes a multiobjective trajectory optimization method that combines the boundary intersection method and pseudospectral method. The multiobjective trajectory optimization problem (MTOP) is established based on the analysis of the feature of hypersonic glider vehicle trajectory. The MTOP is translated into a set of general optimization subproblems by u...

  6. Linking Oppositional Behaviour Trajectories to the Development of Depressive Symptoms in Childhood

    Science.gov (United States)

    Boylan, Khrista; Vaillancourt, Tracy; Szatmari, Peter

    2012-01-01

    Oppositional defiant disorder in childhood is a predictor of later mood disorders. This study assessed whether groups of children can be identified by their course of co-occurring oppositional and depressive symptoms in childhood using group based trajectory modeling. Participants were a cohort of 932 4 or 5 year old offspring of women…

  7. Trajectories of Marital Conflict across the Life Course: Predictors and Interactions with Marital Happiness Trajectories

    Science.gov (United States)

    Kamp Dush, Claire M.; Taylor, Miles G.

    2012-01-01

    Using typologies outlined by Gottman and Fitzpatrick as well as institutional and companionate models of marriage, the authors conducted a latent class analysis of marital conflict trajectories using 20 years of data from the Marital Instability Over the Life Course study. Respondents were in one of three groups: high, medium (around the mean), or…

  8. Aircraft Trajectory Optimization Using Parametric Optimization Theory

    OpenAIRE

    Valenzuela Romero, Alfonso

    2012-01-01

    In this thesis, a study of the optimization of aircraft trajectories using parametric optimization theory is presented. To that end, an approach based on the use of predefined trajectory patterns and parametric optimization is proposed. The trajectory pat

  9. Parental smoking exposure and adolescent smoking trajectories.

    Science.gov (United States)

    Mays, Darren; Gilman, Stephen E; Rende, Richard; Luta, George; Tercyak, Kenneth P; Niaura, Raymond S

    2014-06-01

    In a multigenerational study of smoking risk, the objective was to investigate the intergenerational transmission of smoking by examining if exposure to parental smoking and nicotine dependence predicts prospective smoking trajectories among adolescent offspring. Adolescents (n = 406) ages 12 to 17 and a parent completed baseline interviews (2001-2004), and adolescents completed up to 2 follow-up interviews 1 and 5 years later. Baseline interviews gathered detailed information on parental smoking history, including timing and duration, current smoking, and nicotine dependence. Adolescent smoking and nicotine dependence were assessed at each time point. Latent Class Growth Analysis identified prospective smoking trajectory classes from adolescence into young adulthood. Logistic regression was used to examine relationships between parental smoking and adolescent smoking trajectories. Four adolescent smoking trajectory classes were identified: early regular smokers (6%), early experimenters (23%), late experimenters (41%), and nonsmokers (30%). Adolescents with parents who were nicotine-dependent smokers at baseline were more likely to be early regular smokers (odds ratio 1.18, 95% confidence interval 1.05-1.33) and early experimenters (odds ratio 1.04, 95% confidence interval 1.04-1.25) with each additional year of previous exposure to parental smoking. Parents' current non-nicotine-dependent and former smoking were not associated with adolescent smoking trajectories. Exposure to parental nicotine dependence is a critical factor influencing intergenerational transmission of smoking. Adolescents with nicotine-dependent parents are susceptible to more intense smoking patterns and this risk increases with longer duration of exposure. Research is needed to optimize interventions to help nicotine-dependent parents quit smoking early in their children's lifetime to reduce these risks. Copyright © 2014 by the American Academy of Pediatrics.

  10. A quasiclassical trajectory analysis of stereodynamics of the H+FCl (=0-3, =0-3) → HCl+F reaction

    Indian Academy of Sciences (India)

    Xian-Fang Yue; Xiangyang Miao

    2011-01-01

    The chemical stereodynamics for the title reaction are studied by the quasiclassical trajectory method. Employing the recent works of Deskevich, Hayes, Takahashi, Skodje, and Nesbitt (DHTSN) potential energy surface of the ground 12A' electronic state, the present work calculates the polarizationdependent differential cross sections and the three angular distributions which describe the vector correlations among the product angular momentum j' and the reagent and the product initial relative velocities k and k'. The effect of vibrational and rotational excitations for the reagent FCl and the influence of collision energies on the stereodynamical quantities are also investigated and discussed.

  11. Decentralized architecture for resource management of group-based distributed systems

    Institute of Scientific and Technical Information of China (English)

    Rong ZHANG; Koji ZETTSU; Yutaka KIDAWARA; Yasushi KIYOKI

    2008-01-01

    As the development of hardware and software,large scale,flexible,distributed,secure and coordinated resource sharing has attracted much attention.One of the major challenges is to support distributed group-based resource management,e.g.interest-based organization,with resources/services classifiable.Although there have been some proposals to-address this challenge,they share the same weakness of using either severs or super peers to keep global knowledge,and win good search efficiency at the expenses of the system scalability.As a result,such designs can not keep both the search efficiency and system scalability.To that end,this paper proposes a group-based distributed architecture.It organizes the nodes inside the groups by Chord protocol,a classical Peer-to-Peer (P2P) technology and it defines new communication protocol for nodes among different groups but removes servers/super peers for group management.Such a design keeps the resource classifiable property together with good system performance.The main characteristics of this architecture are highlighted by its convenience for group activity analysis,promising scalability,high search efficiency,as well as robustness.The experimental performance results presented in the paper demonstrate the efficiency of the design.

  12. Trajectory Design to Benefit Trajectory-Based Surface Operations Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Trajectory-based operations constitute a key mechanism considered by the Joint Planning and Development Office (JPDO) for managing traffic in high-density or...

  13. Trajectory Design to Benefit Trajectory-Based Surface Operations Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Trajectory-based operations constitute a key mechanism considered by the Joint Planning and Development Office (JPDO) for managing traffic in high-density or...

  14. Trajectory models and reference frames for crustal motion geodesy

    Science.gov (United States)

    Bevis, Michael; Brown, Abel

    2014-03-01

    We sketch the evolution of station trajectory models used in crustal motion geodesy over the last several decades, and describe some recent generalizations of these models that allow geodesists and geophysicists to parameterize accelerating patterns of displacement in general, and postseismic transient deformation in particular. Modern trajectory models are composed of three sub-models that represent secular trends, annual oscillations, and instantaneous jumps in coordinate time series. Traditionally the trend model invoked constant station velocity. This can be generalized by assuming that position is a polynomial function of time. The trajectory model can also be augmented as needed, by including one or more logarithmic transients in order to account for typical multi-year patterns of postseismic transient motion. Many geodetic and geophysical research groups are using general classes of trajectory model to characterize their crustal displacement time series, but few if any of them are using these trajectory models to define and realize the terrestrial reference frames (RFs) in which their time series are expressed. We describe a global GPS reanalysis program in which we use two general classes of trajectory model, tuned on a station by station basis. We define the network trajectory model as the set of station trajectory models encompassing every station in the network. We use the network trajectory model from the each global analysis to assign prior position estimates for the next round of GPS data processing. We allow our daily orbital solutions to relax so as to maintain their consistency with the network polyhedron. After several iterations we produce GPS time series expressed in a RF similar to, but not identical with ITRF2008. We find that each iteration produces an improvement in the daily repeatability of our global time series and in the predictive power of our trajectory models.

  15. Young adults' trajectories of Ecstasy use: a population based study.

    Science.gov (United States)

    Smirnov, Andrew; Najman, Jake M; Hayatbakhsh, Reza; Plotnikova, Maria; Wells, Helene; Legosz, Margot; Kemp, Robert

    2013-11-01

    Young adults' Ecstasy use trajectories have important implications for individual and population-level consequences of Ecstasy use, but little relevant research has been conducted. This study prospectively examines Ecstasy trajectories in a population-based sample. Data are from the Natural History Study of Drug Use, a retrospective/prospective cohort study conducted in Australia. Population screening identified a probability sample of Ecstasy users aged 19-23 years. Complete data for 30 months of follow-up, comprising 4 time intervals, were available for 297 participants (88.4% of sample). Trajectories were derived using cluster analysis based on recent Ecstasy use at each interval. Trajectory predictors were examined using a generalized ordered logit model and included Ecstasy dependence (World Mental Health Composite International Diagnostic Instrument), psychological distress (Hospital Anxiety Depression Scale), aggression (Young Adult Self Report) and contextual factors (e.g. attendance at electronic/dance music events). Three Ecstasy trajectories were identified (low, intermediate and high use). At its peak, the high-use trajectory involved 1-2 days Ecstasy use per week. Decreasing frequency of use was observed for intermediate and high-use trajectories from 12 months, independently of market factors. Intermediate and high-use trajectory membership was predicted by past Ecstasy consumption (>70 pills) and attendance at electronic/dance music events. High-use trajectory members were unlikely to have used Ecstasy for more than 3 years and tended to report consistently positive subjective effects at baseline. Given the social context and temporal course of Ecstasy use, Ecstasy trajectories might be better understood in terms of instrumental rather than addictive drug use patterns.

  16. Fractional trajectories: Decorrelation versus friction

    Science.gov (United States)

    Svenkeson, A.; Beig, M. T.; Turalska, M.; West, B. J.; Grigolini, P.

    2013-11-01

    The fundamental connection between fractional calculus and subordination processes is explored and affords a physical interpretation of a fractional trajectory, that being an average over an ensemble of stochastic trajectories. Heretofore what has been interpreted as intrinsic friction, a form of non-Markovian dissipation that automatically arises from adopting the fractional calculus, is shown to be a manifestation of decorrelations between trajectories. We apply the general theory developed herein to the Lotka-Volterra ecological model, providing new insight into the final equilibrium state. The relaxation time to achieve this state is also considered.

  17. Early Risk Factors of Overweight Developmental Trajectories during Middle Childhood.

    Directory of Open Access Journals (Sweden)

    Laura E Pryor

    Full Text Available Research is needed to identify early life risk factors associated with different developmental paths leading to overweight by adolescence.To model heterogeneity in overweight development during middle childhood and identify factors associated with differing overweight trajectories.Data was drawn from the Quebec Longitudinal Study of Child Development (QLSCD; 1998-2010. Trained research assistants measured height and weight according to a standardized protocol and conducted yearly home interviews with the child's caregiver (mother in 98% of cases. Information on several putative early life risk factors for the development of overweight were obtained, including factors related to the child's perinatal, early behavioral family and social environment. Group-based trajectories of the probability of overweight (6-12 years were identified with a semiparametric method (n=1678. Logistic regression analyses were used to identify early risk factors (5 months- 5 years associated with each trajectory.Three trajectories of overweight were identified: "early-onset overweight" (11.0 %, "late-onset overweight" (16.6% and "never overweight" (72.5%. Multinomial analyses indicated that children in the early and late-onset group, compared to the never overweight group, had 3 common types of risk factors: parental overweight, preschool overweight history, and large size for gestational age. Maternal overprotection (OR= 1.12, CI: 1.01-1.25, short nighttime sleep duration (OR=1.66, CI: 1.07-2.57, and immigrant status (OR=2.01, CI: 1.05-3.84 were factors specific to the early-onset group. Finally, family food insufficiency (OR=1.81, CI: 1.00-3.28 was weakly associated with membership in the late-onset trajectory group.The development of overweight in childhood follows two different trajectories, which have common and distinct risk factors that could be the target of early preventive interventions.

  18. The trajectory analysis of GPS automatics homing system in a changing wind%GPS自动归航系统在变化风场中的轨迹

    Institute of Scientific and Technical Information of China (English)

    殷俊; 谷雷

    2001-01-01

    This paper analyses the trajectory of GPS automatics homing system in constant wind fields , and discusses the condition under which the gliding parachute system could reach preassigned location. Certain kinds of changing wind fields are presented, the trajectory of radial homing system in changing wind fields were calculated. In order to find weather the radial homing system could reach preassigned location or divergent, simulating program is given. Through the analyses of results of simulation, the solution about head-wind control is presented that GPS orientation technology and the measured data of velocity should be adopted.%研究了全球卫星定位系统(GPS)自动归航系统在恒定风场中归航轨迹的计算,探讨了系统能够达到预定目标点的条件,给出系统在几种变化风场中的轨迹图。为了进一步验证归航轨迹能否回到预定点,给出了系统在变化风场中的仿真算法。并通过对仿真结果的分析,提出在系统着陆期间利用GPS定位和测速数据实行逆风控制的方案。

  19. Motivations for choosing various food groups based on individual foods.

    Science.gov (United States)

    Phan, Uyen T X; Chambers, Edgar

    2016-10-01

    Understanding "why people eat what they eat" is important for improving the lives of people around the world by helping provide industrial and social solutions for people to have greater pleasure and health from the foods they choose. The objective of this study was to investigate the motivations behind everyday choices of different food groups using a bottom-up approach that targeted the specific choices of foods and beverages people consumed at various times of a day. This study was conducted using an online survey included questions related to demographics, the most recent meal including specific food choices, and a slightly modified Eating Motivation Surveys (2 motivations were added, and Check-All-That-Apply procedure was used), which contained 50 sub-scales to measure 17 motivations including such topics as Liking, Pleasure, Convenience, Health, Price, Variety Seeking etc. A total of 198 participants have completed the surveys. Data were analyzed by Correspondence Analysis. Liking was found to be the strongest motivation that drove people to select all sorts of foods. Need and Hunger and Convenience were the main motivations for baked products, "fast" foods, sausages and meats, and snack foods while Health and Weight Control were found to be the main driving factors for vegetables, fruits & fruit juices, nuts, seeds, dairy & egg, and poultry products. Sweets were linked to Pleasure. For beverages, people were motivated most by Heath and Weight Control to choose water and tea. Coffee was used due to Habits; soda was because of Pleasure and alcoholic was for socialization purposes. This study provided developers, marketers, health educators, etc. With a new method to understand food choice in order to promote better eating.

  20. Adaptive Trajectory Design (ATD) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mission design within unstable/stable regions needs unification of individual trajectories from different dynamical regimes. NASA needs an automated process to blend...

  1. Drug use trajectory patterns among older drug users

    Directory of Open Access Journals (Sweden)

    Tyndall B

    2011-05-01

    Full Text Available Miriam Boeri, Thor Whalen, Benjamin Tyndall, Ellen BallardKennesaw State University, Department of Sociology and Criminal Justice, Kennesaw GA, USAAbstract: To better understand patterns of drug use trajectories over time, it is essential to have standard measures of change. Our goal here is to introduce measures we developed to quantify change in drug use behaviors. A secondary goal is to provide effective visualizations of these trajectories for applied use. We analyzed data from a sample of 92 older drug users (ages 45 to 65 to identify transition patterns in drug use trajectories across the life course. Data were collected for every year since birth using a mixed methods design. The community-drawn sample of active and former users were 40% female, 50% African American, and 60% reporting some college or greater. Their life histories provided retrospective longitudinal data on the diversity of paths taken throughout the life course and changes in drug use patterns that occurred over time. Bayesian analysis was used to model drug trajectories displayed by innovative computer graphics. The mathematical techniques and visualizations presented here provide the foundation for future models using Bayesian analysis. In this paper we introduce the concepts of transition counts, transition rates and relapse/remission rates, and we describe how these measures can help us better understand drug use trajectories. Depicted through these visual tools, measurements of discontinuous patterns provide a succinct view of individual drug use trajectories. The measures we use on drug use data will be further developed to incorporate contextual influences on the drug trajectory and build predictive models that inform rehabilitation efforts for drug users. Although the measures developed here were conceived to better examine drug use trajectories, the applications of these measures can be used with other longitudinal datasets.Keywords: drug use, trajectory patterns

  2. Clicker Score Trajectories and Concept Inventory Scores as Predictors for Early Warning Systems for Large STEM Classes

    Science.gov (United States)

    Lee, Un Jung; Sbeglia, Gena C.; Ha, Minsu; Finch, Stephen J.; Nehm, Ross H.

    2015-12-01

    Increasing the retention of STEM (science, technology, engineering, and mathematics) majors has recently emerged as a national priority in undergraduate education. Since poor performance in large introductory science and math courses is one significant factor in STEM dropout, early detection of struggling students is needed. Technology-supported "early warning systems" (EWSs) are being developed to meet these needs. Our study explores the utility of two commonly collected data sources—pre-course concept inventory scores and longitudinal clicker scores—for use in EWS, specifically, in determining the time points at which robust predictions of student success can first be established. The pre-course diagnostic assessments, administered to 287 students, included two concept inventories and one attitude assessment. Clicker question scores were also obtained for each of the 37 class sessions. Additionally, student characteristics (sex, ethnicity, and English facility) were gathered in a survey. Our analyses revealed that all variables were predictive of final grades. The correlation of the first 3 weeks of clicker scores with final grades was 0.53, suggesting that this set of variables could be used in an EWS starting at the third week. We also used group-based trajectory models to assess whether trajectory patterns were homogeneous in the class. The trajectory analysis identified three distinct clicker performance patterns that were also significant predictors of final grade. Trajectory analyses of clicker scores, student characteristics, and pre-course diagnostic assessment appear to be valuable data sources for EWS, although further studies in a diversity of instructional contexts are warranted.

  3. 基于灰色靶关联的智能体任意球轨迹修正方法%Analysis of Intelligent Arbitrary Ball Trajectory Correction Method Based on Grey Correlation

    Institute of Scientific and Technical Information of China (English)

    姚贞光; 刘巧芳

    2014-01-01

    无论是在实体足球比赛还是智能体机器人足球比赛中,近距离的任意球破门收益率较高。研究智能体足球机器人比赛的任意球轨迹修正和优化控制问题,进而指导足球训练提高任意球得分率。提出一种基于灰色靶关联分析的智能体任意球轨迹修正方法,首先对整个机器人足球的环境态势和球员行为体选择进行模型构建,然后给出了灰色靶关联分析的任意球轨迹修正算法,进行球体着力点和应力点的适应值分析,构建基于灰色靶关联分析的任意球应力衰减特性分析模型,指导任意球轨迹修正,最后在智能体足球世界杯3D仿真平台进行实验验证了算法的优越性能。实验结果得出,采用该算法能有效指导任意球发球着力点控制,优化任意球的攻击轨迹,提高智能体机器人足球的任意球进球成功率,预测和控制精度提高。%Either in the real football game or agent in the robot soccer competition, a free kick near distance and higher rate is perfect. Correction of arbitrary ball trajectory is researched for intelligent robot soccer competition and the optimal con⁃trol problem, and then guide the football training is proposed to improve the kick rate. A correction method of grey correla⁃tion analysis of agent is proposed based on arbitrary trajectory of the ball, first to the robot soccer environment situation and player behavior selection of model construction, and then gives the ball trajectory analysis of grey correlation algorithm, sphere to point and stress value analysis, construction of arbitrary ball analysis the grey target association based on the stress analysis model attenuation characteristics, guiding the ball trajectory correction, finally verify the superior perfor⁃mance of the algorithm in intelligent football World Cup in 3D simulation platform. Experimental results show that, the algo⁃rithm can effectively guide the

  4. Entry guidance and trajectory tracking error analysis%再入制导和弹道跟踪误差分析

    Institute of Scientific and Technical Information of China (English)

    Kenneth D.Mease; 杨小龙

    2004-01-01

    新一代可重复使用运载器对再入制导提出了更高地要求.目前的空间运输系统证明基于阻力加速度的制导方法是行之有效的.其基本概念是跟踪基准阻力加速度包线,在飞行过程中可根据需要更新这个包线.跟踪适当的阻力加速度包线保证了飞行器可以飞行准确的距离达到目标,同时满足弹道约束.在横向上,我们可采用类似于美国航天飞机的倾斜反转逻辑或航向角跟踪技术.本文推导出了基于反馈线性化的控制算法,并将其应用于可重复使用运载器纵向和横向的制导.最后,我们分析了阻力加速度跟踪的误差.%The new generation of Reusable Launch Vehicles (RLVs) demands improvements to the current entry guidance capability.The acceleration guidance method has proven effective for the current space transportation system.The basic concept is to track a reference drag acceleration generated by a planner,replanning these profiles periodically if necessary.From the guidance perspective,the trajectory is controlled by adjusting the normal and lateral components of lift to bend the trajectory in the vertical and lateral directions respectively.Tracking an appropriately designed drag profile ensures that the vehicle will fly the correct distance to reach the target without ever violating the vehicle constraints.In the lateral direction,either shuttle type of bank reversal logic or heading angle tracking can be used to ensure that the trajectory will curve such that the desired target is reached.In this paper,we first derive a feedback linearization based control algorithm.We then formulate a baseline entry tracking law for the RLVs.Finally the drag tracking error is analyzed.

  5. Experimental observation of anomalous trajectories of single photons

    Science.gov (United States)

    Zhou, Zong-Quan; Liu, Xiao; Kedem, Yaron; Cui, Jin-Min; Li, Zong-Feng; Hua, Yi-Lin; Li, Chuan-Feng; Guo, Guang-Can

    2017-04-01

    A century after its conception, quantum mechanics still hold surprises that contradict many "common sense" notions. The contradiction is especially sharp in case one consider trajectories of truly quantum objects such as single photons. From a classical point of view, trajectories are well defined for particles, but not for waves. The wave-particle duality forces a breakdown of this dichotomy and quantum mechanics resolves this in a remarkable way: Trajectories can be well defined, but they are utterly different from classical trajectories. Here, we give an operational definition to the trajectory of a single photon by introducing a technique to mark its path using its spectral composition. The method demonstrates that the frequency degree of freedom can be used as a bona fide quantum measurement device (meter). The analysis of a number of setups, using our operational definition, leads to anomalous trajectories which are noncontinuous and in some cases do not even connect the source of the photon to where it is detected. We carried out an experimental demonstration of these anomalous trajectories using a nested interferometer. We show that the two-state vector formalism provides a simple explanation for the results.

  6. Obesity status trajectory groups among elementary school children

    OpenAIRE

    Chen, Tzu-An; Baranowski, Tom; Jennette P. Moreno; O’Connor, Teresia M; Hughes, Sheryl O; Baranowski, Janice; Woehler, Deborah; Kimbro, Rachel T.; Johnston, Craig A.

    2016-01-01

    Background Little is known about patterns in the transition from healthy weight to overweight or obesity during the elementary school years. This study examined whether there were distinct body mass index (BMI) trajectory groups among elementary school children, and predictors of trajectory group membership. Methods This is a secondary analysis of 1651 elementary school children with complete biannual longitudinal data from kindergarten to the beginning of 5th grade. Heights and weights were ...

  7. Transitions in young adulthood: Exploring trajectories of parent-child conflict during college.

    Science.gov (United States)

    Nelson, Sarah C; Bahrassa, Nazneen F; Syed, Moin; Lee, Richard M

    2015-07-01

    This longitudinal study examined trajectories of parent-child conflict from the perspective of young adults during their college years. Using group-based trajectory modeling, self-report data from 3 time points were analyzed and 4 conflict trajectories emerged. The largest group of students (65%) had low, stable levels of parent-child conflict. Ten percent of the sample reported increases in parent-child conflict, and the remainder (25%) reported 1 of 2 patterns of decreasing parent-child conflict. Students with at least 1 immigrant parent were more likely to experience changes in parent-child conflict in contrast to peers with no immigrant parents. Contrary to our hypotheses, individuals in the groups in which conflict was decreasing were more likely to experience psychological distress. Results are discussed in terms of implications for the heterogeneity of conflict trajectories over time, particularly considering the contextual influence of immigrant family status.

  8. Trajectories in Operating a Handheld Tool

    Science.gov (United States)

    Heuer, Herbert; Sulzenbruck, Sandra

    2009-01-01

    The authors studied the trajectories of the hand and of the tip of a handheld sliding first-order lever in aiming movements. With this kind of tool, straight trajectories of the hand are generally associated with curved trajectories of the tip of the lever and vice versa. Trajectories of the tip of the lever exhibited smaller deviations from…

  9. Trajectories in Operating a Handheld Tool

    Science.gov (United States)

    Heuer, Herbert; Sulzenbruck, Sandra

    2009-01-01

    The authors studied the trajectories of the hand and of the tip of a handheld sliding first-order lever in aiming movements. With this kind of tool, straight trajectories of the hand are generally associated with curved trajectories of the tip of the lever and vice versa. Trajectories of the tip of the lever exhibited smaller deviations from…

  10. Asthma trajectories in early childhood: identifying modifiable factors.

    Directory of Open Access Journals (Sweden)

    Lidia Panico

    Full Text Available BACKGROUND: There are conflicting views as to whether childhood wheezing represents several discreet entities or a single but variable disease. Classification has centered on phenotypes often derived using subjective criteria, small samples, and/or with little data for young children. This is particularly problematic as asthmatic features appear to be entrenched by age 6/7. In this paper we aim to: identify longitudinal trajectories of wheeze and other atopic symptoms in early childhood; characterize the resulting trajectories by the socio-economic background of children; and identify potentially modifiable processes in infancy correlated with these trajectories. DATA AND METHODS: The Millennium Cohort Study is a large, representative birth cohort of British children born in 2000-2002. Our analytical sample includes 11,632 children with data on key variables (wheeze in the last year; ever hay-fever and/or eczema reported by the main carers at age 3, 5 and 7 using a validated tool, the International Study of Asthma and Allergies in Childhood module. We employ longitudinal Latent Class Analysis, a clustering methodology which identifies classes underlying the observed population heterogeneity. RESULTS: Our model distinguished four latent trajectories: a trajectory with both low levels of wheeze and other atopic symptoms (54% of the sample; a trajectory with low levels of wheeze but high prevalence of other atopic symptoms (29%; a trajectory with high prevalence of both wheeze and other atopic symptoms (9%; and a trajectory with high levels of wheeze but low levels of other atopic symptoms (8%. These groups differed in terms of socio-economic markers and potential intervenable factors, including household damp and breastfeeding initiation. CONCLUSION: Using data-driven techniques, we derived four trajectories of asthmatic symptoms in early childhood in a large, population based sample. These groups differ in terms of their socio-economic profiles

  11. A Tube-and-Droplet-based Approach for Representing and Analyzing Motion Trajectories.

    Science.gov (United States)

    Lin, Weiyao; Zhou, Yang; Xu, Hongteng; Yan, Junchi; Xu, Mingliang; Wu, Jianxin; Liu, Zicheng

    2016-09-13

    Trajectory analysis is essential in many applications. In this paper, we address the problem of representing motion trajectories in a highly informative way, and consequently utilize it for analyzing trajectories. Our approach first leverages the complete information from given trajectories to construct a thermal transfer field which provides a contextrich way to describe the global motion pattern in a scene. Then, a 3D tube is derived which depicts an input trajectory by integrating its surrounding motion patterns contained in the thermal transfer field. The 3D tube effectively: 1) maintains the movement information of a trajectory, 2) embeds the complete contextual motion pattern around a trajectory, 3) visualizes information about a trajectory in a clear and unified way. We further introduce a droplet-based process. It derives a droplet vector from a 3D tube, so as to characterize the high-dimensional 3D tube information in a simple but effective way. Finally, we apply our tubeand- droplet representation to trajectory analysis applications including trajectory clustering, trajectory classification & abnormality detection, and 3D action recognition. Experimental comparisons with state-of-theart algorithms demonstrate the effectiveness of our approach.

  12. Designing Complex Interplanetary Trajectories for the Global Trajectory Optimization Competitions

    CERN Document Server

    Izzo, Dario; Simões, Luís F; Märtens, Marcus

    2015-01-01

    The design of interplanetary trajectories often involves a preliminary search for options that are later refined into one final selected trajectory. It is this broad search that, often being intractable, inspires the international event called Global Trajectory Optimization Competition. In the first part of this chapter, we introduce some fundamental problems of space flight mechanics, building blocks of any attempt to participate successfully in these competitions and we describe the use of the open source software PyKEP to assemble them into a final global solution strategy. In the second part, we formulate an instance of a multiple asteroid rendezvous problem, related to the 7th edition of the competition, and we show step by step how to build a possible solution strategy. We introduce two new techniques useful in the design of this particular mission type: the use of an asteroid phasing value and its surrogates and the efficient computation of asteroid clusters. We show how basic building blocks, sided to...

  13. Academic trajectories of newcomer immigrant youth.

    Science.gov (United States)

    Suárez-Orozco, Carola; Gaytán, Francisco X; Bang, Hee Jin; Pakes, Juliana; O'Connor, Erin; Rhodes, Jean

    2010-05-01

    Immigration to the United States presents both challenges and opportunities that affect students' academic achievement. Using a 5-year longitudinal, mixed-methods approach, we identified varying academic trajectories of newcomer immigrant students from Central America, China, the Dominican Republic, Haiti, and Mexico. Latent class growth curve analysis revealed that although some newcomer students performed at high or improving levels over time, others showed diminishing performance. Multinomial logistic regressions identified significant group differences in academic trajectories, particularly between the high-achieving youth and the other groups. In keeping with ecological-developmental and stage-environment fit theories, School Characteristics (school segregation rate, school poverty rate, and student perceptions of school violence), Family Characteristics (maternal education, parental employment, and household structure), and Individual Characteristics (academic English proficiency, academic engagement, psychological symptoms, gender, and 2 age-related risk factors, number of school transitions and being overaged for grade placement) were associated with different trajectories of academic performance. A series of case studies triangulate many of the quantitative findings as well as illuminate patterns that were not detected in the quantitative data. Thus, the mixed-methods approach sheds light on the cumulative developmental challenges that immigrant students face as they adjust to their new educational settings.

  14. Complexity of trajectories in rectangular billiards

    CERN Document Server

    Baryshnikov, Yu

    1994-01-01

    To a trajectory of a billiard in a parallelogram we assign its symbolic trajectory --- the sequence of numbers of coordinate planes, to which the faces met by the trajectory are parallel. The complexity of the trajectory is the number of different words of length n occurring in it. We prove that for generic trajectories the complexity is well defined and calculate it, confirming the conjecture of Arnoux, Mauduit, Shiokawa and Tamura[AMST].

  15. Complexity of trajectories in rectangular billiards

    Science.gov (United States)

    Baryshnikov, Yu.

    1995-11-01

    To a trajectory of the billiard in a cube we assign its symbolic trajectory-the sequence of numbers of coordinate planes, to which the faces met by the trajectory are parallel. The complexity of the trajectory is the number of different words of lengthn occurring in it. We prove that for generic trajectories the complexity is well defined and calculate it, confirming the conjecture of Arnoux, Mauduit, Shiokawa and Tamura [AMST].

  16. Group-based discrimination in judgments of moral purity-related behaviors: experimental and archival evidence.

    Science.gov (United States)

    Masicampo, E J; Barth, Maria; Ambady, Nalini

    2014-12-01

    Knowledge of individuals' group membership can alter moral judgments of their behavior. We found that such moral judgments were amplified when judgers learned that a person belonged to a group shown to elicit disgust in others. When a person was labeled as obese, a hippie, or "trailer trash," people judged that person's behavior differently than when such descriptors were omitted: Virtuous behaviors were more highly praised, and moral violations were more severely criticized. Such group-based discrimination in moral judgment was specific to the domain of moral purity. Members of disgust-eliciting groups but not members of other minorities were the target of harsh judgments for purity violations (e.g., lewd behavior) but not for other violations (e.g., refusing to help others). The same pattern held true for virtuous behaviors, so that members of disgust-eliciting groups were more highly praised than others but only in the purity domain. Furthermore, group-based discrimination was mediated by feelings of disgust toward the target group but not by other emotions. Last, analysis of New York Police Department officers' encounters with suspected criminals revealed a similar pattern to that found in laboratory experiments. Police officers were increasingly likely to make an arrest or issue a summons as body mass index increased (i.e., as obesity rose) among people suspected of purity crimes (e.g., prostitution) but not of other crimes (e.g., burglary). Thus, moral judgments in the lab and in the real world exhibit patterns of discrimination that are both group and behavior specific.

  17. Frequency domain synthesis of trajectory learning controllers for robot manipulators

    Directory of Open Access Journals (Sweden)

    Tom Kavli

    1993-07-01

    Full Text Available Trajectory learning control is a method for generating near to optimal feedforward control for systems that are controlled along a reference trajectory in repeated cycles. Iterative refinements of a stored feedforward control sequence corresponding to one cycle of the control trajectory is computed based upon the recorded trajectory error from the previous cycle. Several learning operators have been proposed in earlier work, and convergence proofs are developed for certain classes of systems, but no satisfactory method for design and analysis of learning operators under the presence of uncertainties in the system model have been presented. This article presents frequency domain methods for analysing the convergence properties and performance of the learning controller when the amplitude and phase of the system transfer function is assumed to be within specified windows. Experimental results with an industrial robot manipulator confirm the theoretical results.

  18. Generic trajectory representation and trajectory following for wheeled robots

    DEFF Research Database (Denmark)

    Kjærgaard, Morten; Andersen, Nils Axel; Ravn, Ole

    2014-01-01

    This article presents the work towards a purely generic navigation solution for wheeled mobile robots motivated by the following goals: Generic: Works for different types of robots. Configurable: Parameters maps to geometric properties of the robot. Predictable: Well defined where the robot...... will drive. Safe: Avoid fatal collisions. Based on a survey of existing methods and algorithms the article presents a generic way to represent constraints for different types of robots, a generic way to represent trajectories using Bëzier curves, a method to convert the trajectory so it can be driven...

  19. Weight Change Trajectories After Incident Lower-Limb Amputation.

    Science.gov (United States)

    Bouldin, Erin D; Thompson, Mary Lou; Boyko, Edward J; Morgenroth, David C; Littman, Alyson J

    2016-01-01

    To characterize weight change after amputation by identifying typical weight trajectories in men with incident lower-limb amputation (LLA) and describing characteristics associated with each trajectory. Retrospective cohort study and analyzed using group-based trajectory modeling. Administrative data. Veterans who were men (N=759), living in the Northwest United States, and who had an incident toe, foot, or leg amputation between 1997 and 2008 and at least 18 months of amputation-free survival thereafter. Not applicable. Postamputation weight and body mass index change. The mean weight at baseline was 91.6±24 kg (202±53 lb), and average follow-up was 2.4 years. We identified 4 trajectory groups for weight change: weight loss (13%), stable weight (47%), slow weight gain (33%), and rapid weight gain (7%). Men with a toe or foot amputation most frequently were assigned to the stable weight group (58%), whereas men with transtibial or transfemoral amputations were most commonly assigned to the slow weight gain group (42% each). Men who died during follow-up were more likely to be assigned to the weight loss group (24%) than men who did not die (11%). We identified distinct weight change trajectories that represent heterogeneity in weight change after LLA. An improved understanding of factors predictive of weight gain or loss in people with LLA may help better target rehabilitation and prosthetic prescription. Additional research is needed to fully understand the relation between weight change and health status after amputation. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  20. Contributions of a Group-Based Exercise Program for Coping with Fibromyalgia: A Qualitative Study Giving Voice to Female Patients

    OpenAIRE

    Beltrán Carrillo, Vicente J.; Tortosa Martínez, Juan; Jennings, George; Sánchez, Elena S.

    2013-01-01

    Numerous quantitative studies have illustrated the potential usefulness of exercise programs for women with fibromyalgia. However, a deeper understanding of the physical and especially psychosocial benefits of exercise therapy from the subjective perspective of this population is still needed. This study was conducted with 25 women who had fibromyalgia and were participating in a nine-month, group-based exercise program. The aim was to provide an in-depth description and analysis of the perce...

  1. The Multiobjective Trajectory Optimization for Hypersonic Glide Vehicle Based on Normal Boundary Intersection Method

    Directory of Open Access Journals (Sweden)

    Zhengnan Li

    2016-01-01

    Full Text Available To solve the multiobjective optimization problem on hypersonic glider vehicle trajectory design subjected to complex constraints, this paper proposes a multiobjective trajectory optimization method that combines the boundary intersection method and pseudospectral method. The multiobjective trajectory optimization problem (MTOP is established based on the analysis of the feature of hypersonic glider vehicle trajectory. The MTOP is translated into a set of general optimization subproblems by using the boundary intersection method and pseudospectral method. The subproblems are solved by nonlinear programming algorithm. In this method, the solution that has been solved is employed as the initial guess for the next subproblem so that the time consumption of the entire multiobjective trajectory optimization problem shortens. The maximal range and minimal peak heat problem is solved by the proposed method. The numerical results demonstrate that the proposed method can obtain the Pareto front of the optimal trajectory, which can provide the reference for the trajectory design of hypersonic glider vehicle.

  2. Lunar Landing Trajectory Design for Onboard Hazard Detection and Avoidance

    Science.gov (United States)

    Paschall, Steve; Brady, Tye; Sostaric, Ron

    2009-01-01

    The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project is developing the software and hardware technology needed to support a safe and precise landing for the next generation of lunar missions. ALHAT provides this capability through terrain-relative navigation measurements to enhance global-scale precision, an onboard hazard detection system to select safe landing locations, and an Autonomous Guidance, Navigation, and Control (AGNC) capability to process these measurements and safely direct the vehicle to a landing location. This paper focuses on the key trajectory design issues relevant to providing an onboard Hazard Detection and Avoidance (HDA) capability for the lander. Hazard detection can be accomplished by the crew visually scanning the terrain through a window, a sensor system imaging the terrain, or some combination of both. For ALHAT, this hazard detection activity is provided by a sensor system, which either augments the crew s perception or entirely replaces the crew in the case of a robotic landing. Detecting hazards influences the trajectory design by requiring the proper perspective, range to the landing site, and sufficient time to view the terrain. Following this, the trajectory design must provide additional time to process this information and make a decision about where to safely land. During the final part of the HDA process, the trajectory design must provide sufficient margin to enable a hazard avoidance maneuver. In order to demonstrate the effects of these constraints on the landing trajectory, a tradespace of trajectory designs was created for the initial ALHAT Design Analysis Cycle (ALDAC-1) and each case evaluated with these HDA constraints active. The ALHAT analysis process, described in this paper, narrows down this tradespace and subsequently better defines the trajectory design needed to support onboard HDA. Future ALDACs will enhance this trajectory design by balancing these issues and others in an overall system

  3. Short-Term Trajectories of Depressive Symptoms in Stroke Survivors and Their Family Caregivers.

    Science.gov (United States)

    Malhotra, Rahul; Chei, Choy-Lye; Menon, Edward; Chow, Wai Leng; Quah, Stella; Chan, Angelique; Matchar, David Bruce

    2016-01-01

    We utilize group-based trajectory modeling (GBTM) to delineate depressive symptom trajectories among stroke survivor-caregiver dyads, to identify predictors of the delineated trajectories, and to assess the influence of time-varying covariates (stroke survivor depressive symptoms and functional disability, caregiver depressive symptoms, and foreign domestic worker [FDW] assistance) on the level of the depressive symptom trajectories. Data on 172 stroke survivor-caregiver dyads in Singapore, for whom depressive symptoms were assessed thrice (baseline/3 months/6 months), were utilized. GBTM was applied to delineate depressive symptom trajectories, and to identify their predictors and time-varying covariates. Three stroke survivor depressive symptom trajectories (low and decreasing [47.6%], low and increasing [43.1%], and high and increasing [9.3%]) and 2 caregiver depressive symptom trajectories (low and stable [71.5%] and high and decreasing [28.5%]) were delineated. Caregivers with chronic diseases were more likely (odds ratio [95% confidence interval]: 8.09[2.04-32.07]) and those caring for older stroke survivors (0.94[0.90-0.98]) were less likely to follow the high and decreasing than the low and stable depressive symptom trajectory. An increase in stroke survivor functional disability and caregiver depressive symptoms led to a rise (~worsening) in stroke survivor depressive symptom trajectories. Whereas an increase in stroke survivor depressive symptoms led to a rise in caregiver depressive symptom trajectories, FDW assistance led to a decline (~improvement). Care professionals should be mindful of heterogeneity in depressive symptom patterns over time among stroke survivor-caregiver dyads. Reciprocal association of depressive symptoms in the stroke survivor-caregiver dyad suggests that addressing mood problems in 1 member may benefit the other member, and calls for dyadic mental health interventions. Copyright © 2015 National Stroke Association. Published by

  4. Group-based antenatal birth and parent preparation for improving birth outcomes and parenting resources

    DEFF Research Database (Denmark)

    Koushede, Vibeke; Brixval, Carina Sjöberg; Axelsen, Solveig Forberg

    2013-01-01

    To examine the efficacy and cost-effectiveness of group based antenatal education for improving childbirth and parenting resources compared to auditorium based education.......To examine the efficacy and cost-effectiveness of group based antenatal education for improving childbirth and parenting resources compared to auditorium based education....

  5. Group-based compunction and anger: Their antecedents and consequences in relation to colonial conflicts

    NARCIS (Netherlands)

    Figueiredo, A.; Doosje, B.; Pires Valentim, J.

    2015-01-01

    Group-based emotions can be experienced by group members for the past misdeeds of their ingroup towards an outgroup.. The present study examines distinct antecedents and consequences of group-based compunction and anger in two countries with a history of colonization (Portugal, N = 280 and the Nethe

  6. Trajectory generation of space telerobots

    Science.gov (United States)

    Lumia, R.; Wavering, A. J.

    1989-01-01

    The purpose is to review a variety of trajectory generation techniques which may be applied to space telerobots and to identify problems which need to be addressed in future telerobot motion control systems. As a starting point for the development of motion generation systems for space telerobots, the operation and limitations of traditional path-oriented trajectory generation approaches are discussed. This discussion leads to a description of more advanced techniques which have been demonstrated in research laboratories, and their potential applicability to space telerobots. Examples of this work include systems that incorporate sensory-interactive motion capability and optimal motion planning. Additional considerations which need to be addressed for motion control of a space telerobot are described, such as redundancy resolution and the description and generation of constrained and multi-armed cooperative motions. A task decomposition module for a hierarchical telerobot control system which will serve as a testbed for trajectory generation approaches which address these issues is also discussed briefly.

  7. Trajectory Indexing Using Movement Constraints

    DEFF Research Database (Denmark)

    Pfoser, D.; Jensen, Christian Søndergaard

    2005-01-01

    With the proliferation of mobile computing, the ability to index efficiently the movements of mobile objects becomes important. Objects are typically seen as moving in two-dimensional (x,y) space, which means that their movements across time may be embedded in the three-dimensional (x,y,t) space...... is to reduce movements to occur in one spatial dimension. As a consequence, the movement occurs in two-dimensional (x,t) space. The advantages of considering such lower-dimensional trajectories are that the overall size of the data is reduced and that lower-dimensional data is to be indexed. Since off......-the-shelf database management systems typically do not offer higher-dimensional indexing, this reduction in dimensionality allows us to use existing DBMSes to store and index trajectories. Moreover, we argue that, given the right circumstances, indexing these dimensionality-reduced trajectories can be more efficient...

  8. Dynamical Convergence Trajectory in Networks

    Institute of Scientific and Technical Information of China (English)

    TAN Ning; ZHANG Yun-Jun; OUYANG Qi; GENG Zhi

    2005-01-01

    @@ It is well known that topology and dynamics are two major aspects to determine the function of a network. We study one of the dynamic properties of a network: trajectory convergence, i.e. how a system converges to its steady state. Using numerical and analytical methods, we show that in a logical-like dynamical model, the occurrence of convergent trajectory in a network depends mainly on the type of the fixed point and the ratio between activation and inhibition links. We analytically proof that this property is induced by the competition between two types of state transition structures in phase space: tree-like transition structure and star-like transition structure. We show that the biological networks, such as the cell cycle network in budding yeast, prefers the tree-like transition structures and suggest that this type of convergence trajectories may be universal.

  9. Simulation Propulsion System and Trajectory Optimization

    Science.gov (United States)

    Hendricks, Eric S.; Falck, Robert D.; Gray, Justin S.

    2017-01-01

    A number of new aircraft concepts have recently been proposed which tightly couple the propulsion system design and operation with the overall vehicle design and performance characteristics. These concepts include propulsion technology such as boundary layer ingestion, hybrid electric propulsion systems, distributed propulsion systems and variable cycle engines. Initial studies examining these concepts have typically used a traditional decoupled approach to aircraft design where the aerodynamics and propulsion designs are done a-priori and tabular data is used to provide inexpensive look ups to the trajectory ana-ysis. However the cost of generating the tabular data begins to grow exponentially when newer aircraft concepts require consideration of additional operational parameters such as multiple throttle settings, angle-of-attack effects on the propulsion system, or propulsion throttle setting effects on aerodynamics. This paper proposes a new modeling approach that eliminated the need to generate tabular data, instead allowing an expensive propulsion or aerodynamic analysis to be directly integrated into the trajectory analysis model and the entire design problem optimized in a fully coupled manner. The new method is demonstrated by implementing a canonical optimal control problem, the F-4 minimum time-to-climb trajectory optimization using three relatively new analysis tools: Open M-DAO, PyCycle and Pointer. Pycycle and Pointer both provide analytic derivatives and Open MDAO enables the two tools to be combined into a coupled model that can be run in an efficient parallel manner that helps to cost the increased cost of the more expensive propulsion analysis. Results generated with this model serve as a validation of the tightly coupled design method and guide future studies to examine aircraft concepts with more complex operational dependencies for the aerodynamic and propulsion models.

  10. Group-based Compunction and Anger: Their Antecedents and Consequences in Relation to Colonial Conflicts

    Directory of Open Access Journals (Sweden)

    Ana Figueiredo

    2016-04-01

    Full Text Available Group-based emotions can be experienced by group members for the past misdeeds of their ingroup towards an outgroup.. The present study examines distinct antecedents and consequences of group-based compunction and anger in two countries with a history of colonization (Portugal, N = 280 and the Netherlands, N = 184. While previous research has focused mainly on ingroup-focused antecedents of group-based emotions, such as ingroup identification and perceptions of responsibility, our research also analyzed outgroup-focused variables, such as outgroup identification and meta-perceptions. Multiple group structural equation modeling showed that group-based compunction and group-based anger have similar antecedents (exonerating cognitions, collectivism, outgroup identification and meta-perceptions. Furthermore, the results showed that the two emotions have distinct but related consequences for the improvement of intergroup relations (compensation, subjective importance of discussing the past and forgiveness assignment.

  11. Together we cry: Social motives and preferences for group-based sadness.

    Science.gov (United States)

    Porat, Roni; Halperin, Eran; Mannheim, Ittay; Tamir, Maya

    2016-01-01

    Group-based emotions play an important role in helping people feel that they belong to their group. People are motivated to belong, but does this mean that they actively try to experience group-based emotions to increase their sense of belonging? In this investigation, we propose that people may be motivated to experience even group-based emotions that are typically considered unpleasant to satisfy their need to belong. To test this hypothesis, we examined people's preferences for group-based sadness in the context of the Israeli National Memorial Day. In two correlational (Studies 1a and 1b) and two experimental (Studies 2 and 3) studies, we demonstrate that people with a stronger need to belong have a stronger preference to experience group-based sadness. This effect was mediated by the expectation that experiencing sadness would be socially beneficial (Studies 1 and 2). We discuss the implications of our findings for understanding motivated emotion regulation and intergroup relations.

  12. Lost in Transition or Geared for the S-Curve? An Analysis of Flemish Transition Trajectories with a Focus on Energy Use and Buildings

    Directory of Open Access Journals (Sweden)

    Han Vandevyvere

    2015-02-01

    Full Text Available In recent years, many cities have adopted action plans to become climate neutral in the coming decades. Hereby, a strong motivational factor has been the goal to realize a win-win situation in the long term: climate neutrality and sustainable functioning are not only beneficial for the environment, but are equally beneficial for society and for the economy if well-integrated trajectories are adopted. Nevertheless, as actors across the fields start to implement these plans, many practical obstacles have arisen. These barriers are typical of a systemic transition: dominant practices are characterized by path dependencies, vast institutional frameworks and vested interests that are hard to break through. At the same time, relevant initiatives typically show some elements of uncertainty and a long term return, factors that make it difficult to attract financial investments. The present article addresses the state of the art for current transition experiments in the region of Flanders, Belgium, focusing on actions related to energy and buildings in cities. A brief overview of the state of affairs in several cities and provinces is presented, and some important opportunities and bottlenecks are identified. The resultant findings are tested against the framework of transition theory and related literature on the subject. Subsequently, a set of possible strategies to overcome the above mentioned barriers is formulated. These strategies focus on effectively mobilizing actors and investments.

  13. Fractional Trajectories: Decorrelation Versus Friction

    Science.gov (United States)

    2013-07-27

    function, andmoving back to the time domain yields the fractional trajectory V(t) = Eα(Otα)V(0). (4) Note that the Mittag-Leffler function is defined...bxy) ∂ ∂x − (cy − δxy) ∂ ∂y , (35) with the vector V having the components x and y. The predictor– corrector integration method is adopted to solve...Using the predictor– corrector method with α = 1 we numerically integrate the system of differential equations to find the operational time trajectory

  14. Classical trajectories and quantum tunneling

    CERN Document Server

    Ivlev, B I

    2003-01-01

    The problem of inter-band tunneling in a semiconductor (Zener breakdown) in a nonstationary and homogeneous electric field is solved exactly. Using the exact analytical solution, the approximation based on classical trajectories is studied. A new mechanism of enhanced tunneling through static non-one-dimensional barriers is proposed in addition to well known normal tunneling solely described by a trajectory in imaginary time. Under certain conditions on the barrier shape and the particle energy, the probability of enhanced tunneling is not exponentially small even for non-transparent barriers, in contrast to the case of normal tunneling.

  15. Dynamic trajectory control of gliders

    CERN Document Server

    Dilão, Rui

    2013-01-01

    We propose a new dynamic control algorithm in order to direct the trajectory of a glider to a pre-assigned target point. The algorithms runs iteratively and the approach to the target point is self-correcting. The algorithm is applicable to any non-powered lift-enabled vehicle (glider) travelling in planetary atmospheres. As a proof of concept, we have applied the new algorithm to the command and control of the trajectory of the Space Shuttle during the Terminal Area Energy Management (TAEM) phase.

  16. Destination Prediction by Identifying and Clustering Prominent Features from Public Trajectory Datasets

    Directory of Open Access Journals (Sweden)

    Li Yang

    2015-07-01

    Full Text Available Destination prediction is an essential task in many location-based services (LBS such as providing targeted advertisements and route recommendations. Most existing solutions were generative methods that model the problem as a series of probabilistic events that are then used to compute the destination probability using Bayes’ rule. In contrast, we propose a discriminative method that chooses the most prominent features found in a public trajectory dataset, clusters the trajectories into groups based on these features, and performs destination prediction queries accordingly. Our method is more concise and simple than existing methods while achieving better runtime efficiency and prediction accuracy as verified by experimental studies.

  17. Hybrid Models for Trajectory Error Modelling in Urban Environments

    Science.gov (United States)

    Angelatsa, E.; Parés, M. E.; Colomina, I.

    2016-06-01

    This paper tackles the first step of any strategy aiming to improve the trajectory of terrestrial mobile mapping systems in urban environments. We present an approach to model the error of terrestrial mobile mapping trajectories, combining deterministic and stochastic models. Due to urban specific environment, the deterministic component will be modelled with non-continuous functions composed by linear shifts, drifts or polynomial functions. In addition, we will introduce a stochastic error component for modelling residual noise of the trajectory error function. First step for error modelling requires to know the actual trajectory error values for several representative environments. In order to determine as accurately as possible the trajectories error, (almost) error less trajectories should be estimated using extracted nonsemantic features from a sequence of images collected with the terrestrial mobile mapping system and from a full set of ground control points. Once the references are estimated, they will be used to determine the actual errors in terrestrial mobile mapping trajectory. The rigorous analysis of these data sets will allow us to characterize the errors of a terrestrial mobile mapping system for a wide range of environments. This information will be of great use in future campaigns to improve the results of the 3D points cloud generation. The proposed approach has been evaluated using real data. The data originate from a mobile mapping campaign over an urban and controlled area of Dortmund (Germany), with harmful GNSS conditions. The mobile mapping system, that includes two laser scanner and two cameras, was mounted on a van and it was driven over a controlled area around three hours. The results show the suitability to decompose trajectory error with non-continuous deterministic and stochastic components.

  18. Trajectory Design Considerations for Exploration Mission 1

    Science.gov (United States)

    Dawn, Timothy F.; Gutkowski, Jeffrey P.; Batcha, Amelia L.

    2017-01-01

    Exploration Mission 1 (EM-1) will be the first mission to send an uncrewed Orion vehicle to cislunar space in 2018, targeted to a Distant Retrograde Orbit (DRO). Analysis of EM-1 DRO mission opportunities in 2018 help characterize mission parameters that are of interest to other subsystems (e.g., power, thermal, communications, flight operations, etc). Subsystems request mission design trades which include: landing lighting, addition of an Orion main engine checkout burn, and use of auxiliary thruster only cases. This paper examines the evolving trade studies that incorporate subsystem feedback and demonstrate the feasibility of these constrained mission trajectory designs and contingencies.

  19. Congenitally Deaf Children's Care Trajectories in the Context of Universal Neonatal Hearing Screening: A Qualitative Study of the Parental Experiences

    Science.gov (United States)

    Hardonk, Stefan; Desnerck, Greetje; Loots, Gerrit; Van Hove, Geert; Van Kerschaver, Erwin; Sigurjonsdottir, Hanna Bjorg; Vanroelen, Christophe; Louckx, Fred

    2011-01-01

    The objective of this study is to examine the early care trajectories of congenitally deaf children from a parental perspective, starting with universal neonatal hearing screenings. The analysis using a three-dimensional care trajectory concept is aimed at developing a basic typology of postscreening care trajectories. Children with…

  20. Available Instruments for Analyzing Molecular Dynamics Trajectories.

    Science.gov (United States)

    Likhachev, I V; Balabaev, N K; Galzitskaya, O V

    2016-01-01

    Molecular dynamics trajectories are the result of molecular dynamics simulations. Trajectories are sequential snapshots of simulated molecular system which represents atomic coordinates at specific time periods. Based on the definition, in a text format trajectory files are characterized by their simplicity and uselessness. To obtain information from such files, special programs and information processing techniques are applied: from molecular dynamics animation to finding characteristics along the trajectory (versus time). In this review, we describe different programs for processing molecular dynamics trajectories. The performance of these programs, usefulness for analyses of molecular dynamics trajectories, strong and weak aspects are discussed.

  1. Trajectories of posttraumatic growth and depreciation after two major earthquakes.

    Science.gov (United States)

    Marshall, Emma M; Frazier, Patricia; Frankfurt, Sheila; Kuijer, Roeline G

    2015-03-01

    This study examined trajectories of posttraumatic growth or depreciation (i.e., positive or negative life change) in personal strength and relationships after 2 major earthquakes in Canterbury, New Zealand using group-based trajectory modeling. Participants completed questionnaires regarding posttraumatic growth or depreciation in personal strength and relationship domains 1 month after the first earthquake in September 2010 (N = 185) and 3 months (n = 156) and 12 months (n = 144) after the more severe February 2011 earthquake. Three classes of growth or depreciation patterns were found for both domains. For personal strength, most of the participants were grouped into a "no growth or depreciation" class and smaller proportions were grouped into either a "posttraumatic depreciation" or "posttraumatic growth" class. The 3 classes for relationships all reported posttraumatic growth, differing only in degree. None of the slopes were significant for any of the classes, indicating that levels of growth or depreciation reported after the first earthquake remained stable when assessed at 2 time points after the second earthquake. Multinomial logistic regression analyses examining pre- and postearthquake predictors of trajectory class membership revealed that those in the "posttraumatic growth" personal strength class were significantly younger and had significantly higher pre-earthquake mental health than those in the "posttraumatic depreciation" class. Sex was the only predictor of the relationship classes: No men were assigned to the "high posttraumatic growth" class. Implications and future directions are discussed.

  2. Classical Trajectories and Quantum Spectra

    Science.gov (United States)

    Mielnik, Bogdan; Reyes, Marco A.

    1996-01-01

    A classical model of the Schrodinger's wave packet is considered. The problem of finding the energy levels corresponds to a classical manipulation game. It leads to an approximate but non-perturbative method of finding the eigenvalues, exploring the bifurcations of classical trajectories. The role of squeezing turns out decisive in the generation of the discrete spectra.

  3. Canonical Transformations of Kepler Trajectories

    Science.gov (United States)

    Mostowski, Jan

    2010-01-01

    In this paper, canonical transformations generated by constants of motion in the case of the Kepler problem are discussed. It is shown that canonical transformations generated by angular momentum are rotations of the trajectory. Particular attention is paid to canonical transformations generated by the Runge-Lenz vector. It is shown that these…

  4. Privacy-Preserving Trajectory Collection

    DEFF Research Database (Denmark)

    Gidofalvi, Gyozo; Xuegang, Huang; Pedersen, Torben Bach

    2008-01-01

    . To remedy this situation, this paper first formally defines novel location privacy requirements. Then, it briefly presents a system for privacy--preserving trajectory collection that meets these requirements. The system is composed of an untrusted server and clients communicating in a P2P network. Location...

  5. Association Between Early Life Growth and Blood Pressure Trajectories in Black South African Children.

    Science.gov (United States)

    Kagura, Juliana; Adair, Linda S; Munthali, Richard J; Pettifor, John M; Norris, Shane A

    2016-11-01

    Early growth is associated with blood pressure measured on one occasion, but whether early life growth patterns are associated with longitudinal blood pressure trajectories is under-researched. Therefore, we sought to examine the association between early growth and blood pressure trajectories from childhood to adulthood. Blood pressure was measured on 7 occasions between ages 5 and 18 years in the Birth to Twenty cohort study, and conditional variables for growth in infancy and mid-childhood were computed from anthropometric measures (n=1937, 52% girls). We used a group-based trajectory modeling approach to identify distinct height-adjusted blood pressure trajectories and then tested their association with growth between birth and mid-childhood adjusting for several covariates. Three trajectory groups were identified for systolic and diastolic blood pressure: lower, middle, and upper in boys and girls, separately. In boys, predictors of the middle or upper systolic blood pressure trajectories versus the lower trajectory were in birth weight (odds ratio 0.75 [95% confidence interval 0.58-0.96] per SD) and relative weight gain in infancy (4.11 [1.25-13.51] per SD). In girls, greater relative weight gain and linear growth in both infancy and mid-childhood were consistently associated with an almost 2-fold higher likelihood of being in the upper versus lower systolic blood pressure trajectory. The associations for the diastolic blood pressure trajectories were inconsistent. These findings emphasize the importance of identifying children at risk of progression to high blood pressure. Accelerated growth in infancy and mid-childhood may be a key target for early life intervention in prevention of elevated blood pressure progression. © 2016 American Heart Association, Inc.

  6. Trajectories of delinquency and parenting styles

    NARCIS (Netherlands)

    Hoeve, M.; Blokland, A.; Dubas, J.S.; Loeber, R.; Gerris, J.R.M.; Laan, P.H. van der

    2008-01-01

    We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering

  7. Trajectories of Delinquency and Parenting Styles

    NARCIS (Netherlands)

    Hoeve, M.; Blokland, A.; Dubas, J.S.; Loeber, R.; Gerris, J.R.M.; Laan, P.H. van der

    2008-01-01

    We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering

  8. Trajectories of Delinquency and Parenting Styles

    NARCIS (Netherlands)

    Hoeve, M.; Blokland, A.; Dubas, J.S.; Loeber, R.; Gerris, J.R.M.; Laan, P.H. van der

    2008-01-01

    We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering

  9. Trajectories of delinquency and parenting styles

    NARCIS (Netherlands)

    M. Hoeve; A. van Blokland; J.S. Dubas; R Loeber; J.R.M. Gerris; P.H. van der Laan

    2008-01-01

    We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering

  10. Trajectory Synthesis for Fisher Information Maximization

    Science.gov (United States)

    Wilson, Andrew D.; Schultz, Jarvis A.; Murphey, Todd D.

    2015-01-01

    Estimation of model parameters in a dynamic system can be significantly improved with the choice of experimental trajectory. For general nonlinear dynamic systems, finding globally “best” trajectories is typically not feasible; however, given an initial estimate of the model parameters and an initial trajectory, we present a continuous-time optimization method that produces a locally optimal trajectory for parameter estimation in the presence of measurement noise. The optimization algorithm is formulated to find system trajectories that improve a norm on the Fisher information matrix (FIM). A double-pendulum cart apparatus is used to numerically and experimentally validate this technique. In simulation, the optimized trajectory increases the minimum eigenvalue of the FIM by three orders of magnitude, compared with the initial trajectory. Experimental results show that this optimized trajectory translates to an order-of-magnitude improvement in the parameter estimate error in practice. PMID:25598763

  11. The Trajectory Synthesizer Generalized Profile Interface

    Science.gov (United States)

    Lee, Alan G.; Bouyssounouse, Xavier; Murphy, James R.

    2010-01-01

    The Trajectory Synthesizer is a software program that generates aircraft predictions for Air Traffic Management decision support tools. The Trajectory Synthesizer being used by researchers at NASA Ames Research Center was restricted in the number of trajectory types that could be generated. This limitation was not sufficient to support the rapidly changing Air Traffic Management research requirements. The Generalized Profile Interface was developed to address this issue. It provides a flexible approach to describe the constraints applied to trajectory generation and may provide a method for interoperability between trajectory generators. It also supports the request and generation of new types of trajectory profiles not possible with the previous interface to the Trajectory Synthesizer. Other enhancements allow the Trajectory Synthesizer to meet the current and future needs of Air Traffic Management research.

  12. Individual and group-based learning from complex cognitive tasks: Effects on retention and transfer efficiency

    NARCIS (Netherlands)

    Kirschner, Femke; Paas, Fred; Kirschner, Paul A.

    2009-01-01

    Kirschner, F., Paas, F., & Kirschner, P. (2009). Individual and group-based learning from complex cognitive tasks: Effects on retention and transfer efficiency. Computers in Human Behavior, 25, 306-314.

  13. Estimation of pyrethroid pesticide intake using regression modeling of food groups based on composite dietary samples

    Science.gov (United States)

    Population-based estimates of pesticide intake are needed to characterize exposure for particular demographic groups based on their dietary behaviors. Regression modeling performed on measurements of selected pesticides in composited duplicate diet samples allowed (1) estimation ...

  14. Estimation of pyrethroid pesticide intake using regression modeling of food groups based on composite dietary samples

    Data.gov (United States)

    U.S. Environmental Protection Agency — Population-based estimates of pesticide intake are needed to characterize exposure for particular demographic groups based on their dietary behaviors. Regression...

  15. The Visual Matrix Method: Imagery and Affect in a Group-Based Research Setting

    Directory of Open Access Journals (Sweden)

    Lynn Froggett

    2015-07-01

    Full Text Available The visual matrix is a method for researching shared experience, stimulated by sensory material relevant to a research question. It is led by imagery, visualization and affect, which in the matrix take precedence over discourse. The method enables the symbolization of imaginative and emotional material, which might not otherwise be articulated and allows "unthought" dimensions of experience to emerge into consciousness in a participatory setting. We describe the process of the matrix with reference to the study "Public Art and Civic Engagement" (FROGGETT, MANLEY, ROY, PRIOR & DOHERTY, 2014 in which it was developed and tested. Subsequently, examples of its use in other contexts are provided. Both the matrix and post-matrix discussions are described, as is the interpretive process that follows. Theoretical sources are highlighted: its origins in social dreaming; the atemporal, associative nature of the thinking during and after the matrix which we describe through the Deleuzian idea of the rhizome; and the hermeneutic analysis which draws from object relations theory and the Lorenzerian tradition of scenic understanding. The matrix has been conceptualized as a "scenic rhizome" to account for its distinctive quality and hybrid origins in research practice. The scenic rhizome operates as a "third" between participants and the "objects" of contemplation. We suggest that some of the drawbacks of other group-based methods are avoided in the visual matrix—namely the tendency for inter-personal dynamics to dominate the event. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs150369

  16. Attitudes of older adults in a group-based exercise program towards a blended intervention; a focus-group study.

    Directory of Open Access Journals (Sweden)

    Sumit Mehra

    2016-11-01

    Full Text Available Ageing is associated with a decline in daily functioning and mobility. A physically active life and physical exercise can minimize the decline of daily functioning and improve the physical-, psychological- and social functioning of older adults. Despite several advantages of group-based exercise programs, older adults participating in such interventions often do not meet the frequency, intensity or duration of exercises needed to gain health benefits. An exercise program that combines the advantages of group-based exercises led by an instructor with tailored home-based exercises can increase the effectiveness. Technology can assist in delivering a personalized program. The aim of the study was to determine the susceptibility of older adults currently participating in a nationwide group-based exercise program to such a blended exercise program. Eight focus-groups were held with adults of 55 years of age or older. Two researchers coded independently the remarks of the 30 participants that were included in the analysis according to the three key concepts of the Self Determination Theory: autonomy, competence and relatedness. The results show that maintaining self-reliance and keeping in touch with others were the main motives to participate in the weekly group-based exercises. Participants recognized benefits of doing additional home-based exercises, but had concerns regarding guidance, safety and motivation. Furthermore, some participants strongly rejected the idea to use technology to support them in doing exercises at home, but the majority was open to it. Insights are discussed how these findings can help design novel interventions that can increase the wellbeing of older adults and preserve an independent living.

  17. Minimal Exit Trajectories with Optimum Correctional Manoeuvres

    Directory of Open Access Journals (Sweden)

    T. N. Srivastava

    1980-10-01

    Full Text Available Minimal exit trajectories with optimum correctional manoeuvers to a rocket between two coplaner, noncoaxial elliptic orbits in an inverse square gravitational field have been investigated. Case of trajectories with no correctional manoeuvres has been analysed. In the end minimal exit trajectories through specified orbital terminals are discussed and problem of ref. (2 is derived as a particular case.

  18. 在线重力补偿下工程机器人自主作业轨迹跟踪性能分析%Analysis on autonomous task trajectory tracking performance of construction robot with online gravity compensation

    Institute of Scientific and Technical Information of China (English)

    唐新星; 侯敬巍; 倪涛; 张邦成

    2013-01-01

    By the visual feedback and the space position information of the target object of stereo vision camera, the construction robot can realize the autonomous task according to the kinematics analysis and trajectory planning. However, in the process of the autonomous task, because the link mass of construction robot is big, the driving force of the cylinder calculated by the pressure sensors attached at the cylinders will be divided into two parts, one is used for balancing the link gravity, and the other is used for driving the moving of the cylinder. Therefore, the construction robot will overcome the gravity to work in the process of gravity rising along with the lift of boom and swing of arm, and the links gravity of boom and arm will participate in working in the process of gravity fall along with the dropping of boom and swing of arm, this phenomena will influence the moving velocity of construction robot and the effect of the effect of trajectory tracking, especially in the lifting process, moreover, in the process of the links dropping of construction robot, it is dangerous to the construction robot because of the bigger links masses. Aiming at this problem, the dynamics models of construction robot were deduced followed by kinematics analysis, and the least squares method was used for identifying the dynamics parameters, and then online gravity offset method was purposed based on the dynamics parameters, which was used for eliminating the gravity impact from the driving force of the cylinders, and improving the trajectory tracking effect in autonomous task. Finally, experiment was finished on the construction robot test bench, and the experimental results show that the online gravity compensation algorithm could compensate the gravity of construction robot effectively, and eliminate the influence of gravity working to the trajectory planning of construction robot, and the tracking errors under online gravity compensation are smaller than no gravity compensation

  19. Trajectories of low back pain

    DEFF Research Database (Denmark)

    Axén, Iben; Leboeuf-Yde, Charlotte

    2013-01-01

    Low back pain is not a self-limiting problem, but rather a recurrent and sometimes persistent disorder. To understand the course over time, detailed investigation, preferably using repeated measurements over extended periods of time, is needed. New knowledge concerning short-term trajectories...... indicates that the low back pain 'episode' is short lived, at least in the primary care setting, with most patients improving. Nevertheless, in the long term, low back pain often runs a persistent course with around two-thirds of patients estimated to be in pain after 12 months. Some individuals never have...... low back pain, but most have it on and off or persistently. Thus, the low back pain 'condition' is usually a lifelong experience. However, subgroups of patients with different back pain trajectories have been identified and linked to clinical parameters. Further investigation is warranted...

  20. Geometric diffusion of quantum trajectories.

    Science.gov (United States)

    Yang, Fan; Liu, Ren-Bao

    2015-07-16

    A quantum object can acquire a geometric phase (such as Berry phases and Aharonov-Bohm phases) when evolving along a path in a parameter space with non-trivial gauge structures. Inherent to quantum evolutions of wavepackets, quantum diffusion occurs along quantum trajectories. Here we show that quantum diffusion can also be geometric as characterized by the imaginary part of a geometric phase. The geometric quantum diffusion results from interference between different instantaneous eigenstate pathways which have different geometric phases during the adiabatic evolution. As a specific example, we study the quantum trajectories of optically excited electron-hole pairs in time-reversal symmetric insulators, driven by an elliptically polarized terahertz field. The imaginary geometric phase manifests itself as elliptical polarization in the terahertz sideband generation. The geometric quantum diffusion adds a new dimension to geometric phases and may have applications in many fields of physics, e.g., transport in topological insulators and novel electro-optical effects.

  1. Trajectory Indexing Using Movement Constraints

    DEFF Research Database (Denmark)

    Pfoser, D.; Jensen, Christian Søndergaard

    2005-01-01

    With the proliferation of mobile computing, the ability to index efficiently the movements of mobile objects becomes important. Objects are typically seen as moving in two-dimensional (x,y) space, which means that their movements across time may be embedded in the three-dimensional (x,y,t) space....... Further, the movements are typically represented as trajectories, sequences of connected line segments. In certain cases, movement is restricted; specifically, in this paper, we aim at exploiting that movements occur in transportation networks to reduce the dimensionality of the data. Briefly, the idea...... is to reduce movements to occur in one spatial dimension. As a consequence, the movement occurs in two-dimensional (x,t) space. The advantages of considering such lower-dimensional trajectories are that the overall size of the data is reduced and that lower-dimensional data is to be indexed. Since off...

  2. Ray trajectories for Alcubierre spacetime

    CERN Document Server

    Anderson, Tom H; Lakhtakia, Akhlesh

    2011-01-01

    The Alcubierre spacetime was simulated by means of a Tamm medium which is asymptotically identical to vacuum and has constitutive parameters which are ontinuous functions of the spatial coordinates. Accordingly, the Tamm medium is amenable to physical realization as a nanostructured metamaterial. A comprehensive characterization of ray trajectories in the Tamm medium was undertaken, within the geometric-optics regime. Propagation directions corresponding to evanescent waves were identified: these occur in the region of the Tamm medium which corresponds to the warp bubble of the Alcubierre spacetime, especially for directions perpendicular to the velocity of the warp bubble at high speeds of that bubble. Ray trajectories are acutely sensitive to the magnitude and direction of the warp bubble's velocity, but rather less sensitive to the thickness of the transition zone between the warp bubble and its background. In particular, for rays which travel in the same direction as the warp bubble, the latter acts as a ...

  3. Quantum frictionless trajectories versus geodesics

    Science.gov (United States)

    Barbado, Luis C.; Barceló, Carlos; Garay, Luis J.

    2015-10-01

    Moving particles outside a star will generally experience quantum friction caused by the Unruh radiation reaction. There exist however radial trajectories that lack this effect (in the outgoing radiation sector, and ignoring backscattering). Along these trajectories, observers perceive just stellar emission, without further contribution from the Unruh effect. They turn out to have the property that the variations of the Doppler and the gravitational shifts compensate each other. They are not geodesics, and their proper acceleration obeys an inverse square law, which means that it could in principle be generated by outgoing stellar radiation. In the case of a black hole emitting Hawking radiation, this may lead to a buoyancy scenario. The ingoing radiation sector has little effect and seems to slow down the fall even further.

  4. Interference, reduced action, and trajectories

    OpenAIRE

    2006-01-01

    Instead of investigating the interference between two stationary, rectilinear wave functions in a trajectory representation by examining the two rectilinear wave functions individually, we examine a dichromatic wave function that is synthesized from the two interfering wave functions. The physics of interference is contained in the reduced action for the dichromatic wave function. As this reduced action is a generator of the motion for the dichromatic wave function, it determines the dichroma...

  5. [Oxaliplatin -- A 10-Year Trajectory].

    Science.gov (United States)

    Kanaji, Shingo; Oki, Eiji; Saeki, Hiroshi; Kitao, Hiroyuki; Maehara, Yoshihiko; Kakeji, Yoshihiro

    2016-06-01

    Oxaliplatin(Elplat(®)iv infusion solution)is a third-generation 1,2-DACH-platinum derivative. A number of international clinical trials have investigated the effects of this drug for each of its four indications. Building on the results of these earlier studies, much research has also been carried out in Japan in terms of developing and accumulating evidence on oxaliplatin. This report reviews the trajectory of its use over the last 10-years and considers its future potential.

  6. Periodic billiard trajectories in polyhedra

    CERN Document Server

    Bedaride, Nicolas

    2011-01-01

    We consider the billiard map inside a polyhedron. We give a condition for the stability of the periodic trajectories. We apply this result to the case of the tetrahedron. We deduce the existence of an open set of tetrahedra which have a periodic orbit of length four (generalization of Fagnano's orbit for triangles), moreover we can study completly the orbit of points along this coding.

  7. Perching aerodynamics and trajectory optimization

    Science.gov (United States)

    Wickenheiser, Adam; Garcia, Ephrahim

    2007-04-01

    Advances in smart materials, actuators, and control architecture have enabled new flight capabilities for aircraft. Perching is one such capability, described as a vertical landing maneuver using in-flight shape reconfiguration in lieu of high thrust generation. A morphing, perching aircraft design is presented that is capable of post stall flight and very slow landing on a vertical platform. A comprehensive model of the aircraft's aerodynamics, with special regard to nonlinear affects such as flow separation and dynamic stall, is discussed. Trajectory optimization using nonlinear programming techniques is employed to show the effects that morphing and nonlinear aerodynamics have on the maneuver. These effects are shown to decrease the initial height and distance required to initiate the maneuver, reduce the bounds on the trajectory, and decrease the required thrust for the maneuver. Perching trajectories comparing morphing versus fixed-configuration and stalled versus un-stalled aircraft are presented. It is demonstrated that a vertical landing is possible in the absence of high thrust if post-stall flight capabilities and vehicle reconfiguration are utilized.

  8. Bohmian trajectories of Airy packets

    Energy Technology Data Exchange (ETDEWEB)

    Nassar, Antonio B., E-mail: anassar@hw.com [Science Department, Harvard-Westlake School, 3700 Coldwater Canyon, Studio City, 91604 (United States); Department of Sciences, University of California, Los Angeles, Extension Program, 10995 Le Conte Avenue, Los Angeles, CA 90024 (United States); Miret-Artés, Salvador [Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid (Spain)

    2014-09-15

    The discovery of Berry and Balazs in 1979 that the free-particle Schrödinger equation allows a non-dispersive and accelerating Airy-packet solution has taken the folklore of quantum mechanics by surprise. Over the years, this intriguing class of wave packets has sparked enormous theoretical and experimental activities in related areas of optics and atom physics. Within the Bohmian mechanics framework, we present new features of Airy wave packet solutions to Schrödinger equation with time-dependent quadratic potentials. In particular, we provide some insights to the problem by calculating the corresponding Bohmian trajectories. It is shown that by using general space–time transformations, these trajectories can display a unique variety of cases depending upon the initial position of the individual particle in the Airy wave packet. Further, we report here a myriad of nontrivial Bohmian trajectories associated to the Airy wave packet. These new features are worth introducing to the subject’s theoretical folklore in light of the fact that the evolution of a quantum mechanical Airy wave packet governed by the Schrödinger equation is analogous to the propagation of a finite energy Airy beam satisfying the paraxial equation. Numerous experimental configurations of optics and atom physics have shown that the dynamics of Airy beams depends significantly on initial parameters and configurations of the experimental set-up.

  9. Trajectories of childhood weight gain: the relative importance of local environment versus individual social and early life factors.

    Directory of Open Access Journals (Sweden)

    Megan A Carter

    Full Text Available OBJECTIVE: To determine the association between local environmental factors with child weight status in a longitudinal study, using a semi-parametric, group-based method, while also considering social and early life factors. METHODS: Standardized, directly measured BMI from 4-10 y of age, and group-based trajectory modeling (PROC TRAJ were used to estimate developmental trajectories of weight change in a Québec birth cohort (n = 1,566. Associations between the weight trajectories and living location, social cohesion, disorder, and material and social deprivation were estimated after controlling for social and early life factors. RESULTS: FOUR WEIGHT TRAJECTORY GROUPS WERE ESTIMATED: low-increasing (9.7%; low-medium, accelerating (36.2%; medium-high, increasing (43.0%; and high-stable (11.1%. In the low-increasing and medium-high trajectory groups, living in a semi-urban area was inversely related to weight, while living in a rural area was positively related to weight in the high-stable group. Disorder was inversely related to weight in the low-increasing group only. Other important risk factors for high-stable weight included obesity status of the mother, smoking during pregnancy, and overeating behaviors. CONCLUSIONS: In this study, associations between local environment factors and weight differed by trajectory group. Early life factors appear to play a more consistent role in weight status. Further work is needed to determine the influence of place on child weight.

  10. Life Course Trajectories of Later-Life Cognitive Functions: Does Social Engagement in Old Age Matter?

    Science.gov (United States)

    Park, Sojung; Kwon, Eunsun; Lee, Hyunjoo

    2017-04-07

    This study identified differential patterns of later-life cognitive function trajectories and examined to what extent life course factors and social engagement are associated with group trajectories. Data came from seven waves of the Health and Retirement Study (HRS 1998-2010; n = 7374; Observations = 41,051). Latent class growth analysis identified cognitive function trajectory groups, and multinomial logistic regression was used to examine the factors associated with group trajectories. Five heterogeneous trajectories were identified: stable high, stable moderate, stable low, high-to-moderate, and moderate-to-low. Findings suggest that, after adjusting for life course factors, individuals who became volunteers were more likely to belong to one of the two least vulnerable trajectories, stable high or high-to-moderate. Our findings suggest that, despite the cumulative life course factors evident in cognitive decline, social engagement in old age may serve as a potential protective resource.

  11. Characteristics of barbell trajectory in snatch, fulfilled by elite female weight-lifters

    Directory of Open Access Journals (Sweden)

    Antoniuk O.V.

    2016-12-01

    Full Text Available Purpose: to determine trajectories of elite female weight-lifters’ movements. Material: 137 elite sportswomen were tested. Analysis of sportswomen’s bio-kinematic actions was fulfilled with the help of Weight lifting analyzer 3.0 apparatus, Germany. Results: we found correlation of barbell snatch trajectory in respect to different weight categories of sportswomen. General characteristics of barbell trajectory are equal both for men and women. We determined indicators of barbell grip deviation from vertical axis. Optimal barbell trajectory depends on relative length values of body segments and other important factors. Conclusions: it was proved that execution of 2nd type trajectory of barbell horizontal movement is the most wide spread and effective. Such type of trajectory is the most often for high sport results off light weight categories (48-58 kg.

  12. Mobile Information Collectors' Trajectory Data Warehouse Design

    CERN Document Server

    oueslati, wided

    2010-01-01

    To analyze complex phenomena which involve moving objects, Trajectory Data Warehouse (TDW) seems to be an answer for many recent decision problems related to various professions (physicians, commercial representatives, transporters, ecologists ...) concerned with mobility. This work aims to make trajectories as a first class concept in the trajectory data conceptual model and to design a TDW, in which data resulting from mobile information collectors' trajectory are gathered. These data will be analyzed, according to trajectory characteristics, for decision making purposes, such as new products commercialization, new commerce implementation, etc.

  13. Path-based Queries on Trajectory Data

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Pelekis, Nikos; Theodoridis, Yannis

    2014-01-01

    a specific path by only retrieving data from the first and last edge in the path. To correctly answer strict path queries existing network-constrained trajectory indexes must retrieve data from all edges in the path. An extensive performance study of NETTRA using a very large real-world trajectory data set....... To efficiently support strict path queries, we present a novel NETwork-constrained TRAjectory index (NETTRA). This index enables very efficient retrieval of trajectories that follow a specific path, i.e., strict path queries. NETTRA uses a new path encoding scheme that can determine if a trajectory follows......, consisting of 1.7 million trajectories (941 million GPS records) and a road network with 1.3 million edges, shows a speed-up of two orders of magnitude compared to state-of-the-art trajectory indexes....

  14. Study on Control Algorithm for Continuous Segments Trajectory Interpolation

    Institute of Scientific and Technical Information of China (English)

    SHI Chuan; YE Peiqing; LV Qiang

    2006-01-01

    In CNC machining, the complexity of the part contour causes a series of problems including the repeated start-stop of the motor, low machining efficiency, and poor machining quality. To relieve those problems, a new interpolation algorithm was put forward to realize the interpolation control of continuous sections trajectory. The relevant error analysis of the algorithm was also studied. The feasibility of the algorithm was proved by machining experiment using a laser machine to carve the interpolation trajectory in the CNC system GT100. This algorithm effectively improved the machining efficiency and the contour quality.

  15. Underwater vehicle trajectory estimation using contracting PDE-based observers

    DEFF Research Database (Denmark)

    Jouffroy, Jerome; Opderbecke, Jan

    This paper addresses the issue of estimating underwater vehicle trajectories using Gyro-Doppler (body-fixed velocities) and acoustic signals (earth-fixed positions). The approach consists of diffusion-based observers processing a whole trajectory segment at a time, allowing to consider important...... practical problems such as different information update rates, outages, and outliers in a very simple framework. Results of (Lohmiller and Slotine, 1999) are used to prove that the observers are contracting, i.e. convergent in the sense of contraction analysis. Simulation and experimental results...

  16. PLANCK and WMAP constraints on generalised Hubble flow inflationary trajectories

    Energy Technology Data Exchange (ETDEWEB)

    Contaldi, Carlo R.; Horner, Jonathan S., E-mail: c.contaldi@imperial.ac.uk, E-mail: j.horner11@imperial.ac.uk [Theoretical Physics Group, Blackett Laboratory, Imperial College London, South Kensington, London, SW7 2BZ (United Kingdom)

    2014-08-01

    We use the Hamilton-Jacobi formalism to constrain the space of possible single field, inflationary Hubble flow trajectories when compared to the WMAP and PLANK satellites Cosmic Microwave Background (CMB) results. This method yields posteriors on the space of Hubble Slow Roll (HSR) parameters that uniquely determine the history of the Hubble parameter during the inflating epoch. The trajectories are used to numerically determine the observable primordial power spectrum and bispectra that can then be compared to observations. Our analysis is used to infer the most likely shape of the inflaton potential V(φ) and also yields a prediction for, B, the dimensionless amplitude of the non-Gaussian bispectrum.

  17. Atypical gunshot wound: Bullet trajectory analyzed by computed tomography

    Directory of Open Access Journals (Sweden)

    Tae Ro

    2015-01-01

    Conclusion: If an abnormal trajectory is maintained, it is possible for a bullet to traverse half the length of the body without the patient realizing it. Accurate CT analysis and quick decisions in surgical and medical management are critical takeaways to provide quality care to patients with these injuries.

  18. Contributions to Variations in Academic Trajectories amongst Recent Immigrant Youth

    Science.gov (United States)

    Suarez-Orozco, Carola; Bang, Hee Jin; Onaga, Marie

    2010-01-01

    Immigration presents both challenges and opportunities that affect students' academic achievement. Over the course of five years, varying academic trajectories were identified for recent immigrant students from Central America, China, the Dominican Republic, Haiti, and Mexico. Latent class growth curve analysis revealed that although some students…

  19. Global Launcher Trajectory Optimization for Lunar Base Settlement

    NARCIS (Netherlands)

    Pagano, A.; Mooij, E.

    2010-01-01

    The problem of a mission to the Moon to set a permanent outpost can be tackled by dividing the journey into three phases: the Earth ascent, the Earth-Moon transfer and the lunar landing. In this paper we present an optimization analysis of Earth ascent trajectories of existing launch vehicles inject

  20. Steps towards Participation: The Social Support of Learning Trajectories

    Science.gov (United States)

    Edwards, Anne; Mackenzie, Lin

    2005-01-01

    In this paper we argue that interventions aimed at preventing social exclusion need to be informed by detailed analysis of the formation, disruption, reformation and support of trajectories of participation in the opportunities for action provided. We draw on evidence we gathered on the lives of two women who used an inner city drop-in centre to…

  1. Contributions to Variations in Academic Trajectories amongst Recent Immigrant Youth

    Science.gov (United States)

    Suarez-Orozco, Carola; Bang, Hee Jin; Onaga, Marie

    2010-01-01

    Immigration presents both challenges and opportunities that affect students' academic achievement. Over the course of five years, varying academic trajectories were identified for recent immigrant students from Central America, China, the Dominican Republic, Haiti, and Mexico. Latent class growth curve analysis revealed that although some students…

  2. Scaffolding dynamics and the emergence of problematic learning trajectories

    NARCIS (Netherlands)

    Steenbeek, Henderien; Jansen, Louise; van Geert, Paul

    2012-01-01

    This study aims at examining problematic learning trajectories of students with emotional behavioral disorders (EBD) by means of a longitudinal and time serial (micro genetic) study of individual instruction sessions during arithmetic lessons. Micro genetic analysis techniques were applied on the va

  3. Computer program documentation user information for the MPAD trajectory tape print program (TRJPR1)

    Science.gov (United States)

    Gibbs, P. M.

    1981-01-01

    The Trajectory Tape Print Program (TRJPR1) was developed to print applicable information from a Space Trajectory tape created by the Mission Planning and Analysis Division (MPAD) in the MPAD Common Format for the on-orbit phase of the Mission. Instructions for TRJPR1's use are given.

  4. Trajectory Simulation for Underwater Vehicle with Power-Lunched

    Institute of Scientific and Technical Information of China (English)

    Chaoqian Chen; Wei Cao; Cong Wang∗and Yingjie Wei

    2016-01-01

    The motion of combustion gas bubble produced by underwater ignition was developed based on Rayleigh⁃Plesset equation. Combining the bubble motion equation with the underwater launched vehicle motion equation in the longitudinal plane, a trajectory simulation model with power⁃launched was established. The hydrodynamic characteristics of underwater ignition at different depths and the trajectory analysis of the underwater vehicle with power⁃launched were given by simulation. The simulation results have a good agreement with experimental results, and show that the thrust peak caused by underwater ignition and the stable thrust both decrease slightly with the increase of the water depth, and the thrust peak will decline obviously by enlarging the initial radius of gas bubble; the thrust peak generated at the instant of ignition and the low⁃frequency oscillation of the stable thrust have no significant influence on the trajectory of underwater vehicle.

  5. Evaluating user reputation in online rating systems via an iterative group-based ranking method

    CERN Document Server

    Gao, Jian

    2015-01-01

    Reputation is a valuable asset in online social lives and it has drawn increased attention. How to evaluate user reputation in online rating systems is especially significant due to the existence of spamming attacks. To address this issue, so far, a variety of methods have been proposed, including network-based methods, quality-based methods and group-based ranking method. In this paper, we propose an iterative group-based ranking (IGR) method by introducing an iterative reputation-allocation process into the original group-based ranking (GR) method. More specifically, users with higher reputation have higher weights in dominating the corresponding group sizes. The reputation of users and the corresponding group sizes are iteratively updated until they become stable. Results on two real data sets suggest that the proposed IGR method has better performance and its robustness is considerably improved comparing with the original GR method. Our work highlights the positive role of users' grouping behavior towards...

  6. Employment trajectory as determinant of change in health-related lifestyle: the prospective HeSSup study

    National Research Council Canada - National Science Library

    Virtanen, Pekka; Vahtera, Jussi; Broms, Ulla; Sillanmäki, Lauri; Kivimäki, Mika; Koskenvuo, Markku

    2008-01-01

    .... Associations of the employment trajectories with changes in smoking, alcohol drinking, body weight, physical activity and sleep duration were assessed with analysis of variance for repeated measures...

  7. Longitudinal Trajectories of Ketamine Use among Young Injection Drug Users

    Science.gov (United States)

    Lankenau, Stephen E.; Bloom, Jennifer Jackson; Shin, Charles

    2010-01-01

    Background Ketamine is a dissociative anesthetic that became increasing popular in the club and rave scene in the 1980s and 1990s. Reports surfaced in the late 1990s indicating that ketamine was being injected in several U.S. cities by young injection drug users (IDUs). Since all studies on ketamine injection were cross-sectional, a longitudinal study was undertaken in 2005 to determine: characteristics of young IDUs who continue to inject ketamine; frequency of ketamine injection over an extended time period; risks associated with ongoing ketamine injection; and environmental factors that impact patterns of ketamine use. Methods Young IDUs aged 16 to 29 with a history of injecting ketamine (n=101) were recruited from public locations in Los Angeles and followed during a two-year longitudinal study. A semi-structured instrument captured quantitative and qualitative data on patterns of ketamine injection and other drug use. A statistical model sorted IDUs who completed three or more interviews (n=66) into three groups based upon patterns of ketamine injection at baseline and follow-up. Qualitative analysis focused on detailed case studies within each group. Results IDUs recruited at baseline were typically in their early 20s, male, heterosexual, white, and homeless. Longitudinal injection trajectories included: “Moderates,” who injected ketamine several times per year (n=5); “Occasionals,” who injected ketamine approximately once per year (n=21); and “Abstainers,” who did not inject any ketamine during follow-up (n=40). Findings suggest that ketamine is infrequently injected compared to other drugs such as heroin, cocaine, and methamphetamine. Most IDUs who begin injecting ketamine will stop or curb use due to: negative or ambivalent experiences associated with ketamine; an inability to find the drug due to declining supply; or maturing out of injecting drugs more generally. Conclusion Reducing ketamine injection among young IDUs may best be accomplished

  8. Mobility, education and life trajectories

    DEFF Research Database (Denmark)

    Olwig, Karen Fog; Valentin, Karen

    2015-01-01

    the perspective that education includes a broad range of formative experiences, the articles explore different educational trajectories and the local, regional and transnational relations in which they are embedded. Three key issues emerge from the analyses: firstly, the central role of temporality in terms...... of both the overall historical conditions and the specific biographical circumstances shaping educational opportunities; secondly, the complex agendas informing individuals’ migration and the adjustment of these agendas in the light of the vagaries of migrant life; and thirdly, the importance of migrants...

  9. Quantum Tunneling and Complex Trajectories

    Science.gov (United States)

    Meynig, Max; Haggard, Hal

    2017-01-01

    In general, the semiclassical approximation of quantum mechanical tunneling fails to treat tunneling through barriers if real initial conditions and trajectories are used. By analytically continuing classical dynamics to the complex plane the problems encountered in the approximation can be resolved. While, the complex methods discussed here have been previously explored, no one has exhibited an analytically solvable case. The essential features of the complex method will be discussed in the context of a novel, analytically solvable problem. These methods could be useful in quantum gravity, with applications to the tunneling of spacetime geometries.

  10. Quantum frictionless trajectories versus geodesics

    CERN Document Server

    Barbado, Luis C; Garay, Luis J

    2015-01-01

    Moving particles outside a star will generally experience quantum friction caused by Unruh radiation reaction. There exist however radial trajectories that lack this effect (in the outgoing radiation sector, and ignoring back-scattering). They turn out to have the property that the variations of the Doppler and the gravitational shifts compensate each other. They are not geodesics, and their proper acceleration obeys an inverse square law, which means that could in principle be generated by outgoing stellar radiation. In the case of a black hole emitting Hawking radiation, this may lead to a buoyancy scenario. The ingoing radiation sector has little effect and seems to slow down the fall even further.

  11. Privacy-Preserving Trajectory Collection

    DEFF Research Database (Denmark)

    Gidofalvi, Gyozo; Xuegang, Huang; Pedersen, Torben Bach

    2008-01-01

    In order to provide context--aware Location--Based Services, real location data of mobile users must be collected and analyzed by spatio--temporal data mining methods. However, the data mining methods need precise location data, while the mobile users want to protect their location privacy....... To remedy this situation, this paper first formally defines novel location privacy requirements. Then, it briefly presents a system for privacy--preserving trajectory collection that meets these requirements. The system is composed of an untrusted server and clients communicating in a P2P network. Location...

  12. Ferreting out correlations from trajectory data.

    Science.gov (United States)

    Cukier, Robert I

    2011-12-14

    Thermally driven materials characterized by complex energy landscapes, such as proteins, exhibit motions on a broad range of space and time scales. Principal component analysis (PCA) is often used to extract modes of motion from protein trajectory data that correspond to coherent, functional motions. In this work, two other methods, maximum covariance analysis (MCA) and canonical correlation analysis (CCA) are formulated in a way appropriate to analyze protein trajectory data. Both methods partition the coordinates used to describe the system into two sets (two measurement domains) and inquire as to the correlations that may exist between them. MCA and CCA provide rotations of the original coordinate system that successively maximize the covariance (MCA) or correlation (CCA) between modes of each measurement domain under suitable constraint conditions. We provide a common framework based on the singular value decomposition of appropriate matrices to derive MCA and CCA. The differences between and strengths and weaknesses of MCA and CCA are discussed and illustrated. The application presented here examines the correlation between the backbone and side chain of the peptide met-enkephalin as it fluctuates between open conformations, found in solution, to closed conformations appropriate to when it is bound to its receptor. Difficulties with PCA carried out in Cartesian coordinates are found and motivate a formulation in terms of dihedral angles for the backbone atoms and selected atom distances for the side chains. These internal coordinates are a more reliable basis for all the methods explored here. MCA uncovers a correlation between combinations of several backbone dihedral angles and selected side chain atom distances of met-enkephalin. It could be used to suggest residues and dihedral angles to focus on to favor specific side chain conformers. These methods could be applied to proteins with domains that, when they rearrange upon ligand binding, may have

  13. Trajectories of educational expectations from adolescence to young adulthood in Finland.

    Science.gov (United States)

    Tynkkynen, Lotta; Tolvanen, Asko; Salmela-Aro, Katariina

    2012-11-01

    The purpose of this person-oriented, 5-wave longitudinal study was to examine the trajectories of educational expectations from adolescence to young adulthood in the context of the expectancy-value theory (Eccles et al., 1983). Altogether, 853 (48% female; M age = 16 years) Finnish adolescents reported their educational expectation, 1st in the last year of comprehensive school and 4 times during the following 5 years. Latent class analysis showed that 5 trajectories of educational expectations fit the data best: stable-university (38%), stable-vocational (18%), stable-polytechnic (24%), increasing-expectations (10%), and decreasing-expectations (10%). In line with the expectancy-value theory, adolescents' academic achievement, socioeconomic status (SES), perception of parents' aspirations for them, and ability-beliefs were all related to their trajectories of educational expectations. For example, the higher the adolescent's SES, perception of parents' educational aspirations, and grade point average (GPA), the more likely the participant was to be in the stable-university trajectory compared to the stable-vocational trajectory. Gender had an indirect effect on the trajectories via GPA. Moreover, participants with higher ability-beliefs were more likely to be in trajectories with high and stable educational expectations compared to the unstable trajectories. The trajectories were related to the participants' educational situation after comprehensive school.

  14. PM2.5 chemical composition at a rural background site in Central Europe, including correlation and air mass back trajectory analysis

    Science.gov (United States)

    Schwarz, Jaroslav; Cusack, Michael; Karban, Jindřich; Chalupníčková, Eva; Havránek, Vladimír; Smolík, Jiří; Ždímal, Vladimír

    2016-07-01

    PM2.5 mass concentrations and chemical compositions sampled over a 13-month period at a Central European rural background site (Košetice) are presented in this work. A comprehensive chemical analysis of PM2.5 was performed, which provided elemental composition (Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, Zr, and Pb) and the concentration of water-soluble inorganic anions (SO42 -, NO3-. Cl-, NO2-, Br-, and H2PO4-) and cations (Na+, NH4+, K+, Ca2 +, and Mg2 +), elemental and organic carbon (EC and OC), and levoglucosan. Spearman correlation coefficients between individual chemical species and particle number concentrations were calculated for the following six size ranges: 10-25 nm (N10-25), 25-50 nm (N25-50), 50-80 nm (N50-80), 80-150 nm (N80-150), 150-300 nm (N150-300), and 300-800 nm (N300-800). Average concentrations of individual species were comparable with concentrations reported from similar sites across Central Europe. Organic matter (OM) accounted for 45% of the PM2.5 mass (calculated from OC by a factor of 1.6), while the second most common component were secondary aerosols (SO42 -: 19%, NO3-: 14%, NH4+: 10%), which accounted for 43% of the mass. Based on levoglucosan analysis, 31% of OM was attributed to emissions associated with biomass burning (OMBB). EC concentrations, determined using the EUSAAR_2 thermal optical protocol, contributed 4% to PM2.5 mass. A total of 1% of the mass was attributed to a mineral matter source, while the remaining 6% was from an undetermined mass. Seasonal variations showed highest concentrations of NO3- and OMBB in winter, nitrate share in spring, and an increase in percentage of SO42 - and mineral matter in summer. The largest seasonal variation was found for species associated with wood and coal combustion (levoglucosan, K+, Zn, Pb, As), which had clear maxima during winter. Correlation analysis of different size fraction particle number concentrations was used to distinguish the influence

  15. Evaluation of the Trajectory Sensitivity Analysis of the DFIG Control Parameters in Response to Changes in Wind Speed and the Line Impedance Connection to the Grid DFIG

    Directory of Open Access Journals (Sweden)

    Mehdi Fooladgar

    2015-01-01

    Full Text Available Economic and environmental conditions often make large stations and transmission lines, restrictions are placed. Small and medium-sized production units connected to existing systems as a strategy is in progress. These units are usually near the center of the load placed and distributed generators (DG famous are the DG are allowed types vary, such as induction generators rack squirrel-connected wind turbines, generators fed induction double mounted wind turbines, fuel cells connected to the system by power electronic converters or synchronous generator connected to the turbine combustion [10]. This way sensitivity analysis in systems of distributed generation (DG is assessed. It is shown that the method can detect the effect of control parameters listed wind turbine connected to a double-fed induction generator (DFIG Badoou the impedance of the changing the speed of on the stability of the transmission line useful system invested. The control parameters of the importance of influencing the behavior of DFIG are divided.

  16. Trajectory Codes for Flash Memory

    CERN Document Server

    Anxiao,; Langberg, Michael; Schwartz, Moshe; Bruck, Jehoshua

    2010-01-01

    Flash memory is well-known for its inherent asymmetry: the flash-cell charge levels are easy to increase but are hard to decrease. In a general rewriting model, the stored data changes its value with certain patterns. The patterns of data updates are determined by the data structure and the application, and are independent of the constraints imposed by the storage medium. Thus, an appropriate coding scheme is needed so that the data changes can be updated and stored efficiently under the storage-medium's constraints. In this paper, we define the general rewriting problem using a graph model. It extends many known rewriting models such as floating codes, WOM codes, buffer codes, etc. We present a new rewriting scheme for flash memories, called the trajectory code, for rewriting the stored data as many times as possible without block erasures. We prove that the trajectory code is asymptotically optimal in a wide range of scenarios. We also present randomized rewriting codes optimized for expected performance (g...

  17. Debt trajectories and mental health.

    Science.gov (United States)

    Hojman, Daniel A; Miranda, Álvaro; Ruiz-Tagle, Jaime

    2016-10-01

    In the last few decades, there was a marked increase in consumer debt in the United States, Latin America and other emerging countries, spurring a debate about the real costs and benefits of household credit. Using a unique longitudinal dataset with detailed health and balance sheet information from a large sample of 10,900 Chilean households we study the relationship between debt trajectories in a three-year time window and mental health. We find that depressive symptoms are higher for those who have been persistently over-indebted, followed by those who transit from moderate to high debt levels. We also find that those who transition from over-indebtedness to moderate debt levels have no additional depressive symptoms compared to those with trajectories of moderate debt throughout (never over-indebted). This suggests that the debt-related contribution to depressive symptoms vanishes as debt levels fall. The association between debt and depressive symptoms seems to be driven by non-mortgage debt -primarily consumer credit- or late mortgage payments; secured debt (secured by collateral) per se is not associated with depressive symptoms. Policy interventions to reduce the negative association of over-indebtedness on mental health are discussed.

  18. Information Activities and Appropriation in Teacher Trainees' Digital, Group-Based Learning

    Science.gov (United States)

    Hanell, Fredrik

    2016-01-01

    Introduction: This paper reports results from an ethnographic study of teacher trainees' information activities in digital, group-based learning and their relation to the interplay between use and appropriation of digital tools and the learning environment. Method: The participants in the present study are 249 pre-school teacher trainees in…

  19. Student Perceptions of Group-Based Competitive Exercises in the Chemistry Classroom

    Science.gov (United States)

    Cannon, Kevin C.; Mody, Tina; Breen, Maureen P.

    2008-01-01

    A non-traditional teaching method that can operate as a vehicle for engaging students is group-based competitive exercises. These exercises combine cooperative learning with a competitive environment and may be employed to promote subject- and problem-based learning. Survey responses of college-level organic chemistry and biochemistry students…

  20. Web Environments for Group-Based Project Work in Higher Education

    NARCIS (Netherlands)

    Diepen, van Nico; Collis, Betty; Andernach, Toine

    1997-01-01

    We discuss problems confronting the use of group-based project work as an instructional strategy in higher education and describe two courses in which course-specific World Wide Web (Web) environments have evolved over a series of course sequences and are used both as tool environments for group-pro

  1. Personality Traits and Group-Based Information Behaviour: An Exploratory Study

    Science.gov (United States)

    Hyldegard, Jette

    2009-01-01

    Introduction: The relationship between hypothesised behaviour resulting from a personality test and actual information behaviour resulting from a group-based assignment process is addressed in this paper. Methods: Three voluntary groups of ten librarianship and information science students were followed during a project assignment. The long…

  2. Effectiveness of a Group-Based Program for Parents of Children with Dyslexia

    Science.gov (United States)

    Multhauf, Bettina; Buschmann, Anke; Soellner, Renate

    2016-01-01

    Parents of children with dyslexia experience more parenting stress and depressive symptoms than other parents. The purpose of this study was to evaluate the effects of a cognitive-behavioral group-based program for parents of dyslexic children on parenting stress levels, parent-child homework interactions and parental competencies. 39 children…

  3. The Process Model of Group-Based Emotion : Integrating Intergroup Emotion and Emotion Regulation Perspectives

    NARCIS (Netherlands)

    Goldenberg, Amit; Halperin, Eran; van Zomeren, Martijn; Gross, James J.

    2016-01-01

    Scholars interested in emotion regulation have documented the different goals and strategies individuals have for regulating their emotions. However, little attention has been paid to the regulation of group-based emotions, which are based on individuals' self-categorization as a group member and oc

  4. Introducing group-based asynchronous learning to business education : Reflections on effective course design and delivery

    NARCIS (Netherlands)

    Arnold, I.J.M.; Walker, R.

    2004-01-01

    This paper explores the contribution of virtual tools to student learning within full-time management programmes. More specifically, the paper focuses on asynchronous communication tools, considering the scope they offer for group-based collaborative learning outside the classroom. We report on the

  5. Evaluation of a group-based social skills training for children with problem behavior

    NARCIS (Netherlands)

    van Vugt, E.S.; Deković, M.; Prinzie, P.; Stams, G.J.J.M.; Asscher, J.J.

    2012-01-01

    This study evaluated a group-based training program in social skills targeting reduction of problem behaviors in N = 161 children between 7 and 13 years of age. The effects of the intervention were tested in a quasi-experimental study, with a follow-up assessment 12 months after an optional

  6. The Process Model of Group-Based Emotion : Integrating Intergroup Emotion and Emotion Regulation Perspectives

    NARCIS (Netherlands)

    Goldenberg, Amit; Halperin, Eran; van Zomeren, Martijn; Gross, James J.

    2016-01-01

    Scholars interested in emotion regulation have documented the different goals and strategies individuals have for regulating their emotions. However, little attention has been paid to the regulation of group-based emotions, which are based on individuals' self-categorization as a group member and oc

  7. Introducing group-based asynchronous learning to business education : Reflections on effective course design and delivery

    NARCIS (Netherlands)

    Arnold, I.J.M.; Walker, R.

    2004-01-01

    This paper explores the contribution of virtual tools to student learning within full-time management programmes. More specifically, the paper focuses on asynchronous communication tools, considering the scope they offer for group-based collaborative learning outside the classroom. We report on the

  8. When talking makes you feel like a group: The emergence of group-based emotions.

    Science.gov (United States)

    Yzerbyt, Vincent; Kuppens, Toon; Mathieu, Bernard

    2016-01-01

    Group-based emotions are emotional reactions to group concerns and have been shown to emerge when people appraise events while endorsing a specific social identity. Here we investigate whether discussing a group-relevant event with other group members affects emotional reactions in a similar way. In two experiments, we confronted participants with an unfair group-relevant event, while manipulating their social identity and whether they discussed the event or an unrelated topic. Our major finding is that having group members discuss the unfair group-relevant event led to emotions that were more negative than in the irrelevant discussion and comparable to those observed when social identity had been made salient explicitly beforehand. Moreover, it also generated group-based appraisals of injustice (Experiment 1) and group-based identity (Experiment 2). This research sheds new light not only on the consequences of within-group sharing of emotions for the unfolding of intergroup relations but also on the nature of group-based emotions.

  9. Effectiveness of a Group-Based Program for Parents of Children with Dyslexia

    Science.gov (United States)

    Multhauf, Bettina; Buschmann, Anke; Soellner, Renate

    2016-01-01

    Parents of children with dyslexia experience more parenting stress and depressive symptoms than other parents. The purpose of this study was to evaluate the effects of a cognitive-behavioral group-based program for parents of dyslexic children on parenting stress levels, parent-child homework interactions and parental competencies. 39 children…

  10. The Process Model of Group-Based Emotion: Integrating Intergroup Emotion and Emotion Regulation Perspectives.

    Science.gov (United States)

    Goldenberg, Amit; Halperin, Eran; van Zomeren, Martijn; Gross, James J

    2016-05-01

    Scholars interested in emotion regulation have documented the different goals and strategies individuals have for regulating their emotions. However, little attention has been paid to the regulation of group-based emotions, which are based on individuals' self-categorization as a group member and occur in response to situations perceived as relevant for that group. We propose a model for examining group-based emotion regulation that integrates intergroup emotions theory and the process model of emotion regulation. This synergy expands intergroup emotion theory by facilitating further investigation of different goals (i.e., hedonic or instrumental) and strategies (e.g., situation selection and modification strategies) used to regulate group-based emotions. It also expands emotion regulation research by emphasizing the role of self-categorization (e.g., as an individual or a group member) in the emotional process. Finally, we discuss the promise of this theoretical synergy and suggest several directions for future research on group-based emotion regulation. © 2015 by the Society for Personality and Social Psychology, Inc.

  11. Left Atrial trajectory impairment in Hypertrophic Cardiomyopathy disclosed by Geometric Morphometrics and Parallel Transport

    Science.gov (United States)

    Piras, Paolo; Torromeo, Concetta; Re, Federica; Evangelista, Antonietta; Gabriele, Stefano; Esposito, Giuseppe; Nardinocchi, Paola; Teresi, Luciano; Madeo, Andrea; Chialastri, Claudia; Schiariti, Michele; Varano, Valerio; Uguccioni, Massimo; Puddu, Paolo E.

    2016-10-01

    The analysis of full Left Atrium (LA) deformation and whole LA deformational trajectory in time has been poorly investigated and, to the best of our knowledge, seldom discussed in patients with Hypertrophic Cardiomyopathy. Therefore, we considered 22 patients with Hypertrophic Cardiomyopathy (HCM) and 46 healthy subjects, investigated them by three-dimensional Speckle Tracking Echocardiography, and studied the derived landmark clouds via Geometric Morphometrics with Parallel Transport. Trajectory shape and trajectory size were different in Controls versus HCM and their classification powers had high AUC (Area Under the Receiving Operator Characteristic Curve) and accuracy. The two trajectories were much different at the transition between LA conduit and booster pump functions. Full shape and deformation analyses with trajectory analysis enabled a straightforward perception of pathophysiological consequences of HCM condition on LA functioning. It might be worthwhile to apply these techniques to look for novel pathophysiological approaches that may better define atrio-ventricular interaction.

  12. Left Atrial trajectory impairment in Hypertrophic Cardiomyopathy disclosed by Geometric Morphometrics and Parallel Transport

    Science.gov (United States)

    Piras, Paolo; Torromeo, Concetta; Re, Federica; Evangelista, Antonietta; Gabriele, Stefano; Esposito, Giuseppe; Nardinocchi, Paola; Teresi, Luciano; Madeo, Andrea; Chialastri, Claudia; Schiariti, Michele; Varano, Valerio; Uguccioni, Massimo; Puddu, Paolo E.

    2016-01-01

    The analysis of full Left Atrium (LA) deformation and whole LA deformational trajectory in time has been poorly investigated and, to the best of our knowledge, seldom discussed in patients with Hypertrophic Cardiomyopathy. Therefore, we considered 22 patients with Hypertrophic Cardiomyopathy (HCM) and 46 healthy subjects, investigated them by three–dimensional Speckle Tracking Echocardiography, and studied the derived landmark clouds via Geometric Morphometrics with Parallel Transport. Trajectory shape and trajectory size were different in Controls versus HCM and their classification powers had high AUC (Area Under the Receiving Operator Characteristic Curve) and accuracy. The two trajectories were much different at the transition between LA conduit and booster pump functions. Full shape and deformation analyses with trajectory analysis enabled a straightforward perception of pathophysiological consequences of HCM condition on LA functioning. It might be worthwhile to apply these techniques to look for novel pathophysiological approaches that may better define atrio–ventricular interaction. PMID:27713503

  13. Winding light beams along elliptical helical trajectories

    CERN Document Server

    Wen, Yuanhui; Zhang, Yanfeng; Chen, Hui; Yu, Siyuan

    2016-01-01

    Conventional caustic methods in real or Fourier space produced accelerating optical beams only with convex trajectories. We develop a superposition caustic method capable of winding light beams along non-convex trajectories. We ascertain this method by constructing a one-dimensional (1D) accelerating beam moving along a sinusoidal trajectory, and subsequently extending to two-dimensional (2D) accelerating beams along arbitrarily elliptical helical trajectories. We experimentally implement the method with a compact and robust integrated optics approach by fabricating micro-optical structures on quartz glass plates to perform the spatial phase and amplitude modulation to the incident light, generating beam trajectories highly consistent with prediction. The theoretical and implementation methods can in principle be extended to the construction of accelerating beams with a wide variety of non-convex trajectories, thereby opening up a new route of manipulating light beams for fundamental research and practical ap...

  14. Trajectory data analyses for pedestrian space-time activity study.

    Science.gov (United States)

    Qi, Feng; Du, Fei

    2013-01-01

    It is well recognized that human movement in the spatial and temporal dimensions has direct influence on disease transmission(1-3). An infectious disease typically spreads via contact between infected and susceptible individuals in their overlapped activity spaces. Therefore, daily mobility-activity information can be used as an indicator to measure exposures to risk factors of infection. However, a major difficulty and thus the reason for paucity of studies of infectious disease transmission at the micro scale arise from the lack of detailed individual mobility data. Previously in transportation and tourism research detailed space-time activity data often relied on the time-space diary technique, which requires subjects to actively record their activities in time and space. This is highly demanding for the participants and collaboration from the participants greatly affects the quality of data(4). Modern technologies such as GPS and mobile communications have made possible the automatic collection of trajectory data. The data collected, however, is not ideal for modeling human space-time activities, limited by the accuracies of existing devices. There is also no readily available tool for efficient processing of the data for human behavior study. We present here a suite of methods and an integrated ArcGIS desktop-based visual interface for the pre-processing and spatiotemporal analyses of trajectory data. We provide examples of how such processing may be used to model human space-time activities, especially with error-rich pedestrian trajectory data, that could be useful in public health studies such as infectious disease transmission modeling. The procedure presented includes pre-processing, trajectory segmentation, activity space characterization, density estimation and visualization, and a few other exploratory analysis methods. Pre-processing is the cleaning of noisy raw trajectory data. We introduce an interactive visual pre-processing interface as well as an

  15. Comparative Analysis of Organized Crime Groups based on Income-Generating Crimes: The Case of Erzurum

    Directory of Open Access Journals (Sweden)

    Musa KARAKAYA

    2014-06-01

    Full Text Available Majority of the investigations realized in Turkey, about organized crime groups do not apply to mafia groups that include violence in their criminal activities. In this sense, the organizational structures that have come together to commit other types of crimes needs to be revealed. This study includes investigative works carried out in Erzurum between 01.01.2010-01.12.2013 regarding organized crime groups and based on the document reviews of said investigations. The problem of this study is the differences among Erzurum based organized crime groups regarding their income generating criminal activities. The aim of this study is determination of the differences among organized crime groups under following subtitles; criminal activities, profiles of leaders and members, continuity, division of labor, and hierarchy.

  16. Stabilization of cat paw trajectory during locomotion.

    Science.gov (United States)

    Klishko, Alexander N; Farrell, Bradley J; Beloozerova, Irina N; Latash, Mark L; Prilutsky, Boris I

    2014-09-15

    We investigated which of cat limb kinematic variables during swing of regular walking and accurate stepping along a horizontal ladder are stabilized by coordinated changes of limb segment angles. Three hypotheses were tested: 1) animals stabilize the entire swing trajectory of specific kinematic variables (performance variables); and 2) the level of trajectory stabilization is similar between regular and ladder walking and 3) is higher for forelimbs compared with hindlimbs. We used the framework of the uncontrolled manifold (UCM) hypothesis to quantify the structure of variance of limb kinematics in the limb segment orientation space across steps. Two components of variance were quantified for each potential performance variable, one of which affected it ("bad variance," variance orthogonal to the UCM, VORT) while the other one did not ("good variance," variance within the UCM, VUCM). The analysis of five candidate performance variables revealed that cats during both locomotor behaviors stabilize 1) paw vertical position during the entire swing (VUCM > VORT, except in mid-hindpaw swing of ladder walking) and 2) horizontal paw position in initial and terminal swing (except for the entire forepaw swing of regular walking). We also found that the limb length was typically stabilized in midswing, whereas limb orientation was not (VUCM ≤ VORT) for both limbs and behaviors during entire swing. We conclude that stabilization of paw position in early and terminal swing enables accurate and stable locomotion, while stabilization of vertical paw position in midswing helps paw clearance. This study is the first to demonstrate the applicability of the UCM-based analysis to nonhuman movement.

  17. Girls' childhood trajectories of disruptive behavior predict adjustment problems in early adolescence.

    Science.gov (United States)

    van der Molen, Elsa; Blokland, Arjan A J; Hipwell, Alison E; Vermeiren, Robert R J M; Doreleijers, Theo A H; Loeber, Rolf

    2015-07-01

    It is widely recognized that early onset of disruptive behavior is linked to a variety of detrimental outcomes in males, later in life. In contrast, little is known about the association between girls' childhood trajectories of disruptive behavior and adjustment problems in early adolescence. This study used nine waves of data from the ongoing Pittsburgh Girls Study. A semiparametric group-based model was used to identify trajectories of disruptive behavior in 1,513 girls from age 6 to 12 years. Adjustment problems were characterized by depression, self-harm, Post Traumatic Stress Disorder (PTSD), substance use, interpersonal aggression, sexual behavior, affiliation with delinquent peers, and academic achievement at ages 13 and 14. Three trajectories of childhood disruptive behavior were identified: low, medium, and high. Girls in the high group were at increased risk for depression, self-harm, PTSD, illegal substance use, interpersonal aggression, early and risky sexual behavior, and lower academic achievement. The likelihood of multiple adjustment problems increased with trajectories reflecting higher levels of disruptive behavior. Girls following the high childhood trajectory of disruptive behavior require early intervention programs to prevent multiple, adverse outcomes in adolescence and further escalation in adulthood. © 2014 Association for Child and Adolescent Mental Health.

  18. Girls’ childhood trajectories of disruptive behavior predict adjustment problems in early adolescence

    Science.gov (United States)

    van der Molen, Elsa; Blokland, Arjan A. J.; Hipwell, Alison E.; Vermeiren, Robert R.J.M.; Doreleijers, Theo A.H.; Loeber, Rolf

    2014-01-01

    Background It is widely recognized that early onset of disruptive behavior is linked to a variety of detrimental outcomes in males later in life. In contrast, little is known about the association between girls’ childhood trajectories of disruptive behavior and adjustment problems in early adolescence. Methods The current study used 9 waves of data from the ongoing Pittsburgh Girls Study. A semi-parametric group based model was used to identify trajectories of disruptive behavior in 1,513 girls from age 6 to 12 years. Adjustment problems were characterized by depression, self-harm, PTSD, substance use, interpersonal aggression, sexual behavior, affiliation with delinquent peers, and academic achievement at ages 13 and 14. Results Three trajectories of childhood disruptive behavior were identified: low, medium, and high. Girls in the high group were at increased risk for depression, self-harm, PTSD, illegal substance use, interpersonal aggression, early and risky sexual behavior, and lower academic achievement. The likelihood of multiple adjustment problems increased with trajectories reflecting higher levels of disruptive behavior. Conclusion Girls following the high childhood trajectory of disruptive behavior require early intervention programs to prevent multiple, adverse outcomes in adolescence and further escalation in adulthood. PMID:25302849

  19. Trajectory similarity join in spatial networks

    KAUST Repository

    Shang, Shuo

    2017-09-07

    The matching of similar pairs of objects, called similarity join, is fundamental functionality in data management. We consider the case of trajectory similarity join (TS-Join), where the objects are trajectories of vehicles moving in road networks. Thus, given two sets of trajectories and a threshold θ, the TS-Join returns all pairs of trajectories from the two sets with similarity above θ. This join targets applications such as trajectory near-duplicate detection, data cleaning, ridesharing recommendation, and traffic congestion prediction. With these applications in mind, we provide a purposeful definition of similarity. To enable efficient TS-Join processing on large sets of trajectories, we develop search space pruning techniques and take into account the parallel processing capabilities of modern processors. Specifically, we present a two-phase divide-and-conquer algorithm. For each trajectory, the algorithm first finds similar trajectories. Then it merges the results to achieve a final result. The algorithm exploits an upper bound on the spatiotemporal similarity and a heuristic scheduling strategy for search space pruning. The algorithm\\'s per-trajectory searches are independent of each other and can be performed in parallel, and the merging has constant cost. An empirical study with real data offers insight in the performance of the algorithm and demonstrates that is capable of outperforming a well-designed baseline algorithm by an order of magnitude.

  20. 海洋环境影响声自导鱼雷的弹道分析与动态仿真%Trajectory Analysis and Dynamic Simulation for Acoustic Homing Torpedo Influenced by Marine Environment

    Institute of Scientific and Technical Information of China (English)

    陈建; 张韧; 李佳讯; 彭鹏; 田文通

    2012-01-01

    Aiming at acoustic detection bias of acoustic homing torpedo influenced marine environment, by making use of the comparative analysis and dynamic analysis methods and Argo data, the following topics in both search phase and self-directed phase of torpedo are investigated. The mechanism of marine environment impacting on torpedo's acoustic detection, the strategy of rectifying the bias of torpedo's sound ray tracing and their simulations. The results are shown as follows : in search phase, sea condition remarkably determines the time that the torpedo detects its target, while in self-directed phase, the exist of vertical temperature and salinity gradients generates the trajectory's bias, shortens the encounter time and the total distance, increases the maximum required overload, and the torpedo's final miss distance can be effectively decreased by taking the corresponding correction measures, thus improving its homing performance.%针对海洋环境引起的声自导鱼雷的声探测偏差问题,基于Argo资料,运用动态和对比分析,研究了鱼雷搜索和自导两个阶段中海洋环境对其声探测的影响机制、鱼雷声线轨迹偏差的纠正对策并进行仿真实现.结果表明:在搜索段,海况对鱼雷发现目标的时机具有显著的影响;在自导段,垂直温盐梯度的存在使鱼雷弹道产生偏差、遭遇时间变短、总航程缩短、最大需用过载变大,采取相应的纠正对策可以有效地降低鱼雷的脱靶量、提高自导性能.

  1. A Robot Trajectory Optimization Approach for Thermal Barrier Coatings Used for Free-Form Components

    Science.gov (United States)

    Cai, Zhenhua; Qi, Beichun; Tao, Chongyuan; Luo, Jie; Chen, Yuepeng; Xie, Changjun

    2017-08-01

    This paper is concerned with a robot trajectory optimization approach for thermal barrier coatings. As the requirements of high reproducibility of complex workpieces increase, an optimal thermal spraying trajectory should not only guarantee an accurate control of spray parameters defined by users (e.g., scanning speed, spray distance, scanning step, etc.) to achieve coating thickness homogeneity but also help to homogenize the heat transfer distribution on the coating surface. A mesh-based trajectory generation approach is introduced in this work to generate path curves on a free-form component. Then, two types of meander trajectories are generated by performing a different connection method. Additionally, this paper presents a research approach for introducing the heat transfer analysis into the trajectory planning process. Combining heat transfer analysis with trajectory planning overcomes the defects of traditional trajectory planning methods (e.g., local over-heating), which helps form the uniform temperature field by optimizing the time sequence of path curves. The influence of two different robot trajectories on the process of heat transfer is estimated by coupled FEM models which demonstrates the effectiveness of the presented optimization approach.

  2. Airmass Trajectories and Long Range Transport of Pollutants: Review of Wet Deposition Scenario in South Asia

    Directory of Open Access Journals (Sweden)

    Umesh Kulshrestha

    2014-01-01

    Full Text Available This paper presents a review of airmass trajectories and their role in air pollution transport. It describes the concept, history, and basic calculation of air trajectories citing various trajectory models used worldwide. It highlights various areas of trajectory applications and errors associated with trajectory calculations. South Asian region receives airmasses from Europe, Middle East, Africa, and Indian Ocean, and so forth, depending upon the season. These airmasses are responsible for export and import of pollutants depositing in nearby states. Trajectory analysis revealed that soil is contributed by the dust storms coming from Oman through Gulf and Iran, while most of black carbon (BC sources are located in India. A detailed review of trajectories associated with wet deposition events indicated that airmasses coming from Europe and Middle East carry high concentration of acidic pollutants which are deposited in Himalayan ranges. Similarly, trajectory analysis revealed that acidic pollutants from continental anthropogenic sources are transported to an ecosensitive site in Western Ghats in India and the outward fluxes of anthropogenic activities of Indo-Gangetic region are transported towards Bay of Bengal. Hence, transboundary and long range transport of pollutants are very important issues in South Asia which need immediate attention of scientists and policy makers.

  3. A Robot Trajectory Optimization Approach for Thermal Barrier Coatings Used for Free-Form Components

    Science.gov (United States)

    Cai, Zhenhua; Qi, Beichun; Tao, Chongyuan; Luo, Jie; Chen, Yuepeng; Xie, Changjun

    2017-10-01

    This paper is concerned with a robot trajectory optimization approach for thermal barrier coatings. As the requirements of high reproducibility of complex workpieces increase, an optimal thermal spraying trajectory should not only guarantee an accurate control of spray parameters defined by users (e.g., scanning speed, spray distance, scanning step, etc.) to achieve coating thickness homogeneity but also help to homogenize the heat transfer distribution on the coating surface. A mesh-based trajectory generation approach is introduced in this work to generate path curves on a free-form component. Then, two types of meander trajectories are generated by performing a different connection method. Additionally, this paper presents a research approach for introducing the heat transfer analysis into the trajectory planning process. Combining heat transfer analysis with trajectory planning overcomes the defects of traditional trajectory planning methods (e.g., local over-heating), which helps form the uniform temperature field by optimizing the time sequence of path curves. The influence of two different robot trajectories on the process of heat transfer is estimated by coupled FEM models which demonstrates the effectiveness of the presented optimization approach.

  4. On Integral Invariants for Effective 3-D Motion Trajectory Matching and Recognition.

    Science.gov (United States)

    Shao, Zhanpeng; Li, Youfu

    2016-02-01

    Motion trajectories tracked from the motions of human, robots, and moving objects can provide an important clue for motion analysis, classification, and recognition. This paper defines some new integral invariants for a 3-D motion trajectory. Based on two typical kernel functions, we design two integral invariants, the distance and area integral invariants. The area integral invariants are estimated based on the blurred segment of noisy discrete curve to avoid the computation of high-order derivatives. Such integral invariants for a motion trajectory enjoy some desirable properties, such as computational locality, uniqueness of representation, and noise insensitivity. Moreover, our formulation allows the analysis of motion trajectories at a range of scales by varying the scale of kernel function. The features of motion trajectories can thus be perceived at multiscale levels in a coarse-to-fine manner. Finally, we define a distance function to measure the trajectory similarity to find similar trajectories. Through the experiments, we examine the robustness and effectiveness of the proposed integral invariants and find that they can capture the motion cues in trajectory matching and sign recognition satisfactorily.

  5. Point Return Trajectory Characteristics Analysis for a Lunar Spacecraft%探月飞行器定点返回轨迹特性分析

    Institute of Scientific and Technical Information of China (English)

    沈红新; 李海阳; 彭祺擘; 杜昕

    2011-01-01

    对探月飞行器返回到预期着陆点的轨迹特性进行了研究,着重分析了月球定点返回着陆点和再入点位置的变化规律.分析了返回轨迹特征点的相对位置特性,包括月球反垂点、再入点、近地点,得到了再入点速度、纬度具有变化较稳定的规律.在特征点位置特性研究的基础上,给出了着陆点和再入点位置分析近似方法;基于月相原理研究了着陆点光照条件和月球返回窗口的关系,定性地给出了基本结论.基于双二体模型进行轨迹仿真计算,验证了利用该理论模型分析月球定点返回轨迹的有效性.%The point return orbit characteristics for a vehicle from a lunar mission were studied, and how the landing point and reentry point vary was focused upon. Firstly, analysis of some characteristic points was presented, and lunar anb'pode, reentry point and perigee were included. Tnen the stabilization property of the latitude and velocity at reentry point was achieved. Furthermore, baaed on the characteristics of the foregoing three points, approximate method for the theoretical relation of landing point and reentry point was proposed. In addition, relation of lighting condition at landing point and lunar return window was analyzed by using lunar phase law, and die basic conclusions was attained qualitatively. Finally, the orbit simulation was established with double two-body model, which shows the feasibility of this theoretical model in predicting the lunar point return orbit.

  6. Growth Trajectories of Body Mass Index during Childhood: Associated Factors and Health Outcome at Adulthood.

    Science.gov (United States)

    Péneau, Sandrine; Giudici, Kelly Virecoulon; Gusto, Gaëlle; Goxe, Didier; Lantieri, Olivier; Hercberg, Serge; Rolland-Cachera, Marie-Françoise

    2017-07-01

    To identify body mass index (BMI) trajectories from birth to age 10 years and to assess their association with child and parental characteristics and with adult nutritional status and metabolic risk factors. Retrospective cohort study with 1188 subjects aged 20-60 years. Childhood growth was assessed using measured weight and height data collected retrospectively from health booklets, which also provided information on gestational age, birth weight, and early nutrition. Height, weight, waist circumference, fasting blood glucose, lipids profile, and blood pressure were measured at adulthood. Participants self-reported parental silhouette based on a 9-figural scale. Group-based modeling was applied to identify BMI trajectories. Associations were assessed using ANOVA and multiple logistic regression. Five growth trajectories following or crossing BMI percentiles emerged: stable-25th (15.3% of the sample), stable-50th (35.9%), stable-75th (28.0%), ascending-75th (19.2%), and ascending-obesity (1.6%). Overall, associated factors from early life were mother's corpulence (higher in the ascending-obesity group), gestational age (higher in the stable-50th, stable-75th, and in the ascending-obesity groups), and birth weight (higher in the ascending-obesity group) (all P Childhood trajectories were associated with adult BMI and waist circumference (higher in the stable-75th and in the ascending groups) (all P < .0001). This study shows heterogeneity in patterns of growth trajectories. Specific trajectories were associated with greater BMI and waist circumference during adulthood. Monitoring growth trajectories may improve chronic disease prevention. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Nonsuicidal self-injury in adolescence: longitudinal course, trajectories, and intrapersonal predictors.

    Science.gov (United States)

    Barrocas, Andrea L; Giletta, Matteo; Hankin, Benjamin L; Prinstein, Mitchell J; Abela, John R Z

    2015-02-01

    Although prevalence rates of nonsuicidal self-injury (NSSI) has been established throughout adolescence, little is known about the progression of NSSI, and consequently, about the risk factors for youth NSSI engagement. This study aimed to describe the overall longitudinal course of NSSI and the latent trajectory classes of NSSI in a population-based sample of adolescents using multi-wave data. Moreover, this study examined whether sex, lifetime history of depression, rumination, and negative attributional style predicted the longitudinal course of NSSI and trajectory group membership. Participants were 617 Chinese adolescents in Grades 10 through 12 (51.4 % girls). NSSI was assessed across eight waves of data. History of depression, rumination, and negative attributional style were assessed at baseline. Latent growth curve modeling revealed that only lifetime depression predicted the longitudinal course of NSSI from Grades 10 to 12, with depressed adolescents showing greater and more stable NSSI engagement over time than non-depressed adolescents. Group-based trajectory modeling yielded three distinct trajectory classes of NSSI engagement: low (69.2 %), moderate (26.1 %), and chronic (4.7 %). Negative attributional style distinguished adolescents in the chronic vs. low and moderate NSSI trajectory classes. Sex, rumination, and lifetime depression predicted membership in the chronic and/or moderate vs. low NSSI trajectory class. NSSI trajectory classes, based on frequency of NSSI, exist and are differentiated by sex, depression history, rumination, and negative attributional style. This study suggests that during this period of adolescence NSSI may be a relatively stable behavior, especially for some adolescents. Negative attributional style may be a salient risk factor for chronic NSSI engagement.

  8. Entry Into a Care Trajectory

    Directory of Open Access Journals (Sweden)

    Normand Carpentier

    2013-06-01

    Full Text Available A broad range of services are developing in response to the needs of an aging population. Although most interventions are carried out in the patient’s living environment—at the heart of society—few studies on service utilization refer to social theory. This paper suggests that studies on older people with chronic health conditions would benefit from a stronger theoretical foundation. Drawing on 15 in-depth interviews, it highlights the relevance of individualization processes and the network society, 2 central theoretical concerns in sociology. The research provides a unique perspective on the entry into the care trajectory and expands our comprehension of the emergence of a social organization that can respond to the needs of elderly patients. Data of this nature may be useful in service planning and the development of a care-centered approach.

  9. Low-thrust rocket trajectories

    Energy Technology Data Exchange (ETDEWEB)

    Keaton, P.W.

    1986-01-01

    The development of low-thrust propulsion systems to complement chemical propulsion systems will greatly enhance the evolution of future space programs. Two advantages of low-thrust rockets are stressed: first, in a strong gravitational field, such as occurs near the Earth, freighter missions with low-thrust engines require one-tenth as much propellant as do chemical engines. Second, in a weak gravitational field, such as occurs in the region between Venus and Mars, low-thrust rockets are faster than chemical rockets with comparable propellant mass. The purpose here is to address the physics of low-thrust trajectories and to interpret the results with two simple models. Analytic analyses are used where possible - otherwise, the results of numerical calculations are presented in graphs. The author has attempted to make this a self-contained report. 57 refs., 10 figs.

  10. Low-thrust rocket trajectories

    Energy Technology Data Exchange (ETDEWEB)

    Keaton, P.W.

    1987-03-01

    The development of low-thrust propulsion systems to complement chemical propulsion systems will greatly enhance the evolution of future space programs. Two advantages of low-thrust rockets are stressed: first, in a strong gravitational field, such as occurs near the Earth, freighter missions with low-thrust engines require one-tenth as much propellant as do chemical engines. Second, in a weak gravitational field, such as occurs in the region between Venus and Mars, low-thrust rockets are faster than chemical rockets with comparable propellant mass. The purpose here is to address the physics of low-thrust trajectories and to interpret the results with two simple models. Analytic analyses are used where possible - otherwise, the results of numerical calculations are presented in graphs. The author has attempted to make this a self-contained report.

  11. The association between trajectories of endocrine therapy adherence and mortality among women with breast cancer.

    Science.gov (United States)

    Winn, Aaron N; Dusetzina, Stacie B

    2016-08-01

    Studies examining adherence to endocrine therapy (ET) and breast cancer-related outcomes have traditionally used the proportion of days covered (PDC) by medication to define adherence which may mask true treatment-outcome associations for patients with different medication use behaviors. We use group-based trajectory models to examine the association between ET adherence patterns and mortality compared to a standard PDC adherence measure. Using Surveillance, Epidemiology and End Results-Medicare data we included 9492 women with breast cancer who initiated ET between 2007 and 2010. We excluded women who died/recurred in the 12 months after ET initiation. We used monthly group-based trajectory models to characterize longitudinal adherence patterns and adjusted Cox proportional hazard models to estimate the association between ET adherence and mortality, comparing trajectory-based adherence to traditional PDC-based measures. Trajectory models identified five adherence groups: (i) high (56.2%); (ii) quick decline (9.5%); (iii) moderate decline (7.9%); (iv) quick decline, then increase (16.0%); and (v) slow decline (10.5%). Mortality was significantly associated with group assignment; compared to the high adherers, there was a significantly higher risk of death among quick declines (HR = 1.41, 95%CI = 1.09-1.72) and moderate declines (HR = 1.25, 95%CI = 1.00-1.55). Using the standard PDC adherence measure women with adherence adherence ≥80% (HR = 1.21, 95%CI = 1.06-1.38). Defining ET adherence using trajectory models improved adherence measurement. These models could inform clinical practice by helping to identify common adherence patterns, potential areas for intervention and better isolate adherence-related outcomes in comparative effectiveness studies. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Trajectories of Marijuana Use among HIV-seropositive and HIV-seronegative MSM in the Multicenter AIDS Cohort Study (MACS), 1984-2013.

    Science.gov (United States)

    Okafor, Chukwuemeka N; Cook, Robert L; Chen, Xinguang; Surkan, Pamela J; Becker, James T; Shoptaw, Steve; Martin, Eileen; Plankey, Michael W

    2017-04-01

    To construct longitudinal trajectories of marijuana use in a sample of men who have sex with men living with or at-risk for HIV infection. We determined factors associated with distinct trajectories of use as well as those that serve to modify the course of the trajectory. Data were from 3658 [1439 HIV-seropositive (HIV+) and 2219 HIV-seronegative (HIV-)] participants of the Multicenter AIDS Cohort Study. Frequency of marijuana use was obtained semiannually over a 29-year period (1984-2013). Group-based trajectory models were used to identify the trajectories and to determine predictors and modifiers of the trajectories over time. Four distinct trajectories of marijuana use were identified: abstainer/infrequent (65 %), decreaser (13 %), increaser (12 %) and chronic high (10 %) use groups. HIV+ status was significantly associated with increased odds of membership in the decreaser, increaser and chronic high use groups. Alcohol, smoking, stimulant and other recreational drug use were associated with increasing marijuana use across all four trajectory groups. Antiretroviral therapy use over time was associated with decreasing marijuana use in the abstainer/infrequent and increaser trajectory groups. Having a detectable HIV viral load was associated with increasing marijuana use in the increaser group only. Future investigations are needed to determine whether long-term patterns of use are associated with adverse consequences especially among HIV+ persons.

  13. Trend-Residual Dual Modeling for Detection of Outliers in Low-Cost GPS Trajectories.

    Science.gov (United States)

    Chen, Xiaojian; Cui, Tingting; Fu, Jianhong; Peng, Jianwei; Shan, Jie

    2016-12-01

    Low-cost GPS (receiver) has become a ubiquitous and integral part of our daily life. Despite noticeable advantages such as being cheap, small, light, and easy to use, its limited positioning accuracy devalues and hampers its wide applications for reliable mapping and analysis. Two conventional techniques to remove outliers in a GPS trajectory are thresholding and Kalman-based methods, which are difficult in selecting appropriate thresholds and modeling the trajectories. Moreover, they are insensitive to medium and small outliers, especially for low-sample-rate trajectories. This paper proposes a model-based GPS trajectory cleaner. Rather than examining speed and acceleration or assuming a pre-determined trajectory model, we first use cubic smooth spline to adaptively model the trend of the trajectory. The residuals, i.e., the differences between the trend and GPS measurements, are then further modeled by time series method. Outliers are detected by scoring the residuals at every GPS trajectory point. Comparing to the conventional procedures, the trend-residual dual modeling approach has the following features: (a) it is able to model trajectories and detect outliers adaptively; (b) only one critical value for outlier scores needs to be set; (c) it is able to robustly detect unapparent outliers; and (d) it is effective in cleaning outliers for GPS trajectories with low sample rates. Tests are carried out on three real-world GPS trajectories datasets. The evaluation demonstrates an average of 9.27 times better performance in outlier detection for GPS trajectories than thresholding and Kalman-based techniques.

  14. Trend-Residual Dual Modeling for Detection of Outliers in Low-Cost GPS Trajectories

    Directory of Open Access Journals (Sweden)

    Xiaojian Chen

    2016-12-01

    Full Text Available Low-cost GPS (receiver has become a ubiquitous and integral part of our daily life. Despite noticeable advantages such as being cheap, small, light, and easy to use, its limited positioning accuracy devalues and hampers its wide applications for reliable mapping and analysis. Two conventional techniques to remove outliers in a GPS trajectory are thresholding and Kalman-based methods, which are difficult in selecting appropriate thresholds and modeling the trajectories. Moreover, they are insensitive to medium and small outliers, especially for low-sample-rate trajectories. This paper proposes a model-based GPS trajectory cleaner. Rather than examining speed and acceleration or assuming a pre-determined trajectory model, we first use cubic smooth spline to adaptively model the trend of the trajectory. The residuals, i.e., the differences between the trend and GPS measurements, are then further modeled by time series method. Outliers are detected by scoring the residuals at every GPS trajectory point. Comparing to the conventional procedures, the trend-residual dual modeling approach has the following features: (a it is able to model trajectories and detect outliers adaptively; (b only one critical value for outlier scores needs to be set; (c it is able to robustly detect unapparent outliers; and (d it is effective in cleaning outliers for GPS trajectories with low sample rates. Tests are carried out on three real-world GPS trajectories datasets. The evaluation demonstrates an average of 9.27 times better performance in outlier detection for GPS trajectories than thresholding and Kalman-based techniques.

  15. Trajectories of quality of life among Chinese patients diagnosed with nasopharynegeal cancer.

    Directory of Open Access Journals (Sweden)

    Wendy W T Lam

    Full Text Available OBJECTIVE: This secondary longitudinal analysis describes distinct quality of life trajectories during eight months of radiation therapy (RT among patients with nasopharyngeal cancer (NPC and examines factors differentiating these trajectories. METHODS: 253 Chinese patients with NPC scheduled for RT were assessed at pre-treatment, and 4 months and 8 months later on QoL (Chinese version of the FACT-G, optimism, pain, eating function, and patient satisfaction. Latent growth mixture modelling identified different trajectories within each of four QoL domains: Physical, Emotional, Social/family, and Functional well-being. Multinomial logistic regression compared optimism, pain, eating function, and patient satisfaction by trajectories adjusted for demographic and medical characteristics. RESULTS: We identified three distinct trajectories for physical and emotional QoL domains, four trajectories for social/family, and two trajectories for functional domains. Within each domain most patients (physical (77%, emotional (85%, social/family (55% and functional (63% experienced relatively stable high levels of well-being over the 8-month period. Different Physical trajectory patterns were predicted by pain and optimism, whereas for Emotion-domain trajectories pain, optimism, eating enjoyment, patient satisfaction with information, and gender were predictive. Age, appetite, optimism, martial status, and household income predicted Social/family trajectories; household income, eating enjoyment, optimism, and patient satisfaction with information predicted Functional trajectories. CONCLUSION: Most patients with NPC showed high stable QoL during radiotherapy. Optimism predicted good QoL. Symptom impacts varied by QoL domain. Information satisfaction was protective in emotional and functional well-being, reflecting the importance in helping patients to establish a realistic expectation of treatment impacts.

  16. Radial and angular-momentum Regge trajectories: a systematic approach

    Directory of Open Access Journals (Sweden)

    Arriola E.R.

    2012-12-01

    Full Text Available We present the analysis of Ref. [1] of the radial (n and angular-momentum (J Regge trajectories for all light-quark meson states listed in the Particle Data Tables. The parameters of the trajectories are obtained with linear regression, with weight of each resonance inversely proportional to its half-width squared, (Γ/22. The joint analysis in the (n, J, M2 Regge plane indicates, at the 4.5 standard deviation level, that the slopes in n are larger from the slopes in J. Thus no strict universality of slopes occurs in the light non-strange meson sector. We also extend our analysis to the kaon sector.

  17. High Speed Solution of Spacecraft Trajectory Problems Using Taylor Series Integration

    Science.gov (United States)

    Scott, James R.; Martini, Michael C.

    2008-01-01

    Taylor series integration is implemented in a spacecraft trajectory analysis code-the Spacecraft N-body Analysis Program (SNAP) - and compared with the code s existing eighth-order Runge-Kutta Fehlberg time integration scheme. Nine trajectory problems, including near Earth, lunar, Mars and Europa missions, are analyzed. Head-to-head comparison at five different error tolerances shows that, on average, Taylor series is faster than Runge-Kutta Fehlberg by a factor of 15.8. Results further show that Taylor series has superior convergence properties. Taylor series integration proves that it can provide rapid, highly accurate solutions to spacecraft trajectory problems.

  18. Uncertainty dimensions of information behaviour in a group based problem solving context

    DEFF Research Database (Denmark)

    Hyldegård, Jette

    2009-01-01

    This paper presents a study of uncertainty dimensions of information behaviour in a group based problem solving context. After a presentation of the cognitive uncertainty dimension underlying Kuhlthau's ISP-model, uncertainty factors associated with personality, the work task situation and social......-dimensional phenomenon, which should not be studied out of context. On the other hand, this complexity of the uncertainty concept also represents a methodological and practical challenge to the researcher as well as the practioner....

  19. Computer-Aided Robot Trajectory Auto-generation Strategy in Thermal Spraying

    Science.gov (United States)

    Cai, Zhenhua; Liang, Hong; Quan, Shuhai; Deng, Sihao; Zeng, Chunnian; Zhang, Feng

    2015-10-01

    This paper is concerned with a new methodology which is designed to auto-generate the robotic trajectory for thermal spraying process. Based on it, a software package named Thermal Spray Toolkit is developed and integrated in the main frame of off-line programming software RobotStudio™ (Product of ABB Company, Sweden). This toolkit implements the robotic trajectory planning in an interactive manner between RobotStudio™ and the finite element analysis software (FES). It allows rearranging the imported node index created on the surface of workpiece by FES and in turn generating the thermal spraying needed robot trajectories. Several parameters in thermal spraying, such as scanning step and torch-substrate relative velocity which have major influence on the coating deposition, are considered in the trajectory generation process. Experiment is carried out to check the reliability of the generated robot trajectory.

  20. Towards Efficient Search for Activity Trajectories

    DEFF Research Database (Denmark)

    Zheng, Kai; Shang, Shuo; Yuan, Jing

    2013-01-01

    The advances in location positioning and wireless communication technologies have led to a myriad of spatial trajectories representing the mobility of a variety of moving objects. While processing trajectory data with the focus of spatio-temporal features has been widely studied in the last decad...

  1. Trajectories of CBCL Attention Problems in childhood

    NARCIS (Netherlands)

    Robbers, S.C.C.; Oort, F.V.A. van; Polderman, T.J.C.; Bartels, M.; Boomsma, D.I.; Verhulst, F.C.; Huizink, A.C.

    2011-01-01

    The first aim of this study was to identify developmental trajectories of Attention Problems in twins followed from age 6 to 12 years. Second, we investigated whether singletons follow similar trajectories. Maternal longitudinal ratings on the Attention Problems (AP) subscale of the Child Behavior

  2. Trajectories of Delinquency and Parenting Styles

    Science.gov (United States)

    Hoeve, Machteld; Blokland, Arjan; Dubas, Judith Semon; Loeber, Rolf; Gerris, Jan R. M.; van der Laan, Peter H.

    2008-01-01

    We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering ages 10-19, we identified five distinct…

  3. Comment on "The envelope of projectile trajectories"

    CERN Document Server

    Butikov, E I

    2003-01-01

    Several simple alternative methods to obtain the equation of the envelope of the family of projectile trajectories corresponding to the same initial speed are suggested, including methods in which the boundary of the region occupied by the parabolic trajectories is found as an envelope of a set of circles. Two possible generalizations of the discussed problem are also suggested. (letters and comments)

  4. Estimation of motility parameters from trajectory data

    DEFF Research Database (Denmark)

    Vestergaard, Christian L.; Pedersen, Jonas Nyvold; Mortensen, Kim I.;

    2015-01-01

    Given a theoretical model for a self-propelled particle or micro-organism, how does one optimally determine the parameters of the model from experimental data in the form of a time-lapse recorded trajectory? For very long trajectories, one has very good statistics, and optimality may matter little...... to which similar results may be obtained also for self-propelled particles....

  5. A Framework for Context-aware Trajectory

    NARCIS (Netherlands)

    Bogorny, V.; Wachowicz, M.

    2009-01-01

    The recent advances in technologies for mobile devices, like GPS and mobile phones, are generating large amounts of a new kind of data: trajectories of moving objects. These data are normally available as sample points, with very little or no semantics. Trajectory data can be used in a variety of ap

  6. Efficient Spatial Keyword Search in Trajectory Databases

    CERN Document Server

    Cong, Gao; Ooi, Beng Chin; Zhang, Dongxiang; Zhang, Meihui

    2012-01-01

    An increasing amount of trajectory data is being annotated with text descriptions to better capture the semantics associated with locations. The fusion of spatial locations and text descriptions in trajectories engenders a new type of top-$k$ queries that take into account both aspects. Each trajectory in consideration consists of a sequence of geo-spatial locations associated with text descriptions. Given a user location $\\lambda$ and a keyword set $\\psi$, a top-$k$ query returns $k$ trajectories whose text descriptions cover the keywords $\\psi$ and that have the shortest match distance. To the best of our knowledge, previous research on querying trajectory databases has focused on trajectory data without any text description, and no existing work has studied such kind of top-$k$ queries on trajectories. This paper proposes one novel method for efficiently computing top-$k$ trajectories. The method is developed based on a new hybrid index, cell-keyword conscious B$^+$-tree, denoted by \\cellbtree, which enabl...

  7. Simulation of Airplane and Rocket Trajectories

    Science.gov (United States)

    Wahbah, Magdy M.; Berning, Michael J.; Choy, Tony S.

    1987-01-01

    Simulation and Optimization of Rocket Trajectories program (SORT) contains comprehensive mathematical models for simulating aircraft dynamics, freely falling objects, and many types of ballistic trajectories. Provides high-fidelity, three-degrees-of-freedom simulation for atmospheric and exoatmospheric flight. It numerically models vehicle subsystems and vehicle environment. Used for wide range of simulations. Written in machine-independent FORTRAN 77.

  8. Efficient Calculation of Earth Penetrating Projectile Trajectories

    Science.gov (United States)

    2006-09-01

    CALCULATION OF EARTH PENETRATING PROJECTILE TRAJECTORIES by Daniel F . Youch September 2006 Thesis Advisor: Joshua Gordis... Daniel F . Youch 5. FUNDING NUMBERS 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School Monterey, CA 93943-5000 8. PERFORMING...EFFICIENT CALCULATION OF EARTH PENETRATING PROJECTILE TRAJECTORIES Daniel F . Youch Lieutenant Commander, United States Navy B.S., Temple

  9. Trajectories of CBCL Attention Problems in childhood

    NARCIS (Netherlands)

    S.C.C. Robbers (Sylvana); F.V.A. van Oort (Floor); T.J.C. Polderman (Tinca); M. Bartels (Meike); D.I. Boomsma (Dorret); F.C. Verhulst (Frank); G.H. Lubke (Gitta); A.C. Huizink (Anja)

    2011-01-01

    textabstractThe first aim of this study was to identify developmental trajectories of Attention Problems in twins followed from age 6 to 12 years. Second, we investigated whether singletons follow similar trajectories. Maternal longitudinal ratings on the Attention Problems (AP) subscale of the Chil

  10. A Multistage Control Mechanism for Group-Based Machine-Type Communications in an LTE System

    Directory of Open Access Journals (Sweden)

    Wen-Chien Hung

    2013-01-01

    Full Text Available When machine-type communication (MTC devices perform the long-term evolution (LTE attach procedure without bit rate limitations, they may produce congestion in the core network. To prevent this congestion, the LTE standard suggests using group-based policing to regulate the maximum bit rate of all traffic generated by a group of MTC devices. However, previous studies on the access point name-aggregate maximum bit rate based on group-based policing are relatively limited. This study proposes a multistage control (MSC mechanism to process the operations of maximum bit rate allocation based on resource-use information. For performance evaluation, this study uses a Markov chain with to analyze MTC application in a 3GPP network. Traffic flow simulations in an LTE system indicate that the MSC mechanism is an effective bandwidth allocation method in an LTE system with MTC devices. Experimental results show that the MSC mechanism achieves a throughput 22.5% higher than that of the LTE standard model using the group-based policing, and it achieves a lower delay time and greater long-term fairness as well.

  11. IMPACTS OF GROUP-BASED SIGNAL CONTROL POLICY ON DRIVER BEHAVIOR AND INTERSECTION SAFETY

    Directory of Open Access Journals (Sweden)

    Keshuang TANG

    2008-01-01

    Full Text Available Unlike the typical stage-based policy commonly applied in Japan, the group-based control (often called movement-based in the traffic control industry in Japan refers to such a control pattern that the controller is capable of separately allocating time to each signal group instead of stage based on traffic demand. In order to investigate its applicability at signalized intersections in Japan, an intersection located in Yokkaichi City of Mie Prefecture was selected as an experimental application site by the Japan Universal Traffic Management Society (UTMS. Based on the data collected at the intersection before and after implementing the group-based control policy respectively, this study evaluated the impacts of such a policy on driver behavior and intersection safety. To specify those impacts, a few models utilizing cycle-based data were first developed to interpret the occurrence probability and rate of red-light-running (RLR. Furthermore, analyses were performed on the yellow-entry time (Ye of the last cleared vehicle and post encroachment time (PET during the phase switching. Conclusions supported that the group-based control policy, along with certain other factors, directly or indirectly influenced the RLR behavior of through and right-turn traffics. Meanwhile, it has potential safety benefits as well, indicated by the declined Ye and increased PET values.

  12. Global 4-D trajectory optimization for spacecraft

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Global 4-D trajectory(x,y,z,t)is optimized for a spacecraft,which is launched from the Earth to fly around the Sun,just as star-drift of 1437 asteroids in the solar system.The spacecraft trajectory is controlled by low thrust.The performance index of optimal trajectory is to maximize the rendezvous times with the intermediate asteroids,and also maximize the final mass.This paper provides a combined algorithm of global 4-D trajectory optimization.The algorithm is composed of dynamic programming and two-point-boundary algorithm based on optimal control theory.The best 4-D trajectory is obtained:the spacecraft flies passing 55 asteroids,and rendezvous with(following or passing again)asteroids for 454 days,and finally rendezvous with the asteroid 2005SN25 on the day 60521(MJD),the final mass of the spacecraft is 836.53 kg.

  13. Trajectory Dispersion Control for the Cassini Grand Finale Mission

    Science.gov (United States)

    Wong, Mau; Hahn, Yungsun; Roth, Duane; Vaquero, Mar

    2015-01-01

    The Cassini Grand Finale Mission, which consists of 22 ballistic orbits, will begin on April 22, 2017 after the last targeted Titan flyby. It will end on September 15, 2017 when the spacecraft dives into Saturn's atmosphere and be permanently captured. High volumes of unique science data from various onboard instruments are expected from the mission. To ensure its success and facilitate science planning, the trajectory dispersion needs to be controlled below 250 km (root-mean-square spatial deviation at the 68th percentile level) for a few segments of trajectory in the mission. This paper reports the formulation and solution of this dispersion control problem. We consider various sources of uncertainties including flyby error, orbit determination error, maneuver execution error, thruster firing control error, and uncertainty in Saturn's atmospheric model. A non-linear Monte Carlo Trajectory Dispersion tool is developed and employed for the analysis. It is found that a total of three Orbit Trim Maneuvers with a 99% (Delta)V usage of less than 2 m/s will adequately control the trajectory.

  14. Trajectories of Work Disability and Economic Insecurity Approaching Retirement.

    Science.gov (United States)

    Shuey, Kim M; Willson, Andrea E

    2017-07-08

    In this article, we examine the connection between trajectories of work disability and economic precarity in late midlife. We conceptualize work disability as a possible mechanism linking early and later life economic disadvantage. We model trajectories of work disability characterized by timing and stability for a cohort of Baby Boomers (22-32 in 1981) using 32 years of data from the Panel Study of Income Dynamics and latent class analysis. Measures of childhood disadvantage are included as predictors of work disability trajectories, which are subsequently included in logistic regression models predicting four economic outcomes (poverty, asset poverty, home ownership, and pension ownership) at ages 54-64. Childhood disadvantage selected individuals into five distinct classes of work disability that differed in timing and stability. All of the disability trajectories were associated with an increased risk of economic insecurity in late midlife compared to the never work disabled. This study contributes to the aging literature through its incorporation of the early life origins of pathways of disability and their links to economic outcomes approaching retirement. Findings suggest work disability is anchored in early life disadvantage and is associated with economic insecurity later in life.

  15. Trajectory control strategy of cathodes in blisk electrochemical machining

    Institute of Scientific and Technical Information of China (English)

    Zhu Dong; Zhu Di; Xu Zhengyang; Zhou Laishui

    2013-01-01

    A turbine blisk,which combines blades and a disk together,is one of the most important components of an aero engine.In the process of blisk electrochemical machining (ECM),the sheet cathode,which is usually used as a tool electrode,has a complicated structure.In addition to that,the channel between the adjacent blades is narrow and twisted,so interference is apt to happen when the sheet cathode feeds into the channel.Therefore,it is important to choose suitable trajectory control strategy.In this paper,a new trajectory control strategy of the sheet cathode is presented and corresponding simulation analysis is conducted on the basis of an actual blisk model.The simulation results demonstrate that the sheet cathode can feed into the channel by a spatial line trajectory without interference.Moreover,the verification experiments are carried out according to the simulation.The experimental results show that the cathode can move into the channel without interference.It is verified that the new trajectory control strategy is correct and can be used in the blisk ECM process successfully.

  16. The enduring effect of education-socioeconomic differences in disability trajectories from age 85 years in the Newcastle 85+ Study

    Science.gov (United States)

    Kingston, Andrew; Davies, Karen; Collerton, Joanna; Robinson, Louise; Duncan, Rachel; Kirkwood, Thomas B.L.; Jagger, Carol

    2015-01-01

    Objective Little is known about disability progression in very old age despite this being vital for care planning. We investigate whether distinct trajectories of disability are evident from age 85 to 90 and their association with socio-economic status (SES). Methods The Newcastle 85+ Study recruited people born in 1921 through participating general practices in Newcastle and North Tyneside. Participants underwent a health assessment (HA) at baseline, 18, 36 and 60 months and a GP record review (GPRR) at baseline, 36 and 60 months. Disability was measured via difficulty in 17 Activities of Daily Living. Trajectory identification was assessed by gender stratified, mortality adjusted, group-based trajectory modelling (GBTM) and the impact of life-course SES (level of education; occupational class; deprivation) on trajectory membership evaluated (adjusting for confounding variables). Results 851 participants agreed to HA and GPRR, 840 (98.7%) with complete disability data. Four distinct trajectories were evident for both sexes. A disability-free trajectory between age 85 and 90 was identified in men only (9% of the sample). The most disabled trajectories had severe disability at age 85 progressing to profound disability by age 90. After adjusting for confounders education remained significant; men and women with most education being less likely to be in the most disabled trajectory (Men: OR = 0.80, 95% CI 0.65–0.98; women: OR = 0.59, 95% CI 0.42–0.83). Conclusion Distinct disability trajectories are evident in the very old and these are influenced by education, suggesting SES disadvantages cumulate throughout the life-course to create health and mortality inequalities later. PMID:25747850

  17. Application of group-based QSAR on 2-thioxo-4-thiazolidinone for development of potent anti-diabetic compounds

    Science.gov (United States)

    Choudhari, Prafulla; Kumbhar, Santosh; Phalle, Siddharth; Choudhari, Sujata; Desai, Sujit; Khare, Shivratna; Jadhav, Swapnil

    2017-01-01

    To identify the structural requirement for development of lead structures with PPAR gamma binding activity group based quantitative structure activity relationship (GQSAR) studies on 46 reported structures were carried out. The molecules in the current dataset were fragmented into seven functional groups fragments (R1, R2, R3, R4, R5, R6 and R7). GQSAR models were derived using multiple linear regressions analysis. Four generated GQSAR models were selected based on the statistical significance of the model. It was found that the presence of smaller groups on fragment R7 and presence of lipophilic group at fragment R2 was conducive for PPAR gamma binding. Additionally, the existence of hydrogen bond acceptor at fragments R6 was fruitful PPAR gamma binding. The generated models provide a site-specific insight into the structural requirements PPAR γ binding which can be used to design and develop potent antidiabetic compounds.

  18. Zeno Paradox for Bohmian Trajectories: The Unfolding of the Metatron

    CERN Document Server

    de Gosson, Maurice

    2010-01-01

    We study an analogue of the quantum Zeno paradox for the Bohm trajectory of a sharply located particle (or a system of particles). We show that a continuously observed Bohm trajectory is the classical trajectory predicted by Hamiltonian mechanics.

  19. Inferring Taxi Status Using GPS Trajectories

    CERN Document Server

    Zhu, Yin; Zhang, Liuhang; Santani, Darshan; Xie, Xing; Yang, Qiang

    2012-01-01

    In this paper, we infer the statuses of a taxi, consisting of occupied, non-occupied and parked, in terms of its GPS trajectory. The status information can enable urban computing for improving a city's transportation systems and land use planning. In our solution, we first identify and extract a set of effective features incorporating the knowledge of a single trajectory, historical trajectories and geographic data like road network. Second, a parking status detection algorithm is devised to find parking places (from a given trajectory), dividing a trajectory into segments (i.e., sub-trajectories). Third, we propose a two-phase inference model to learn the status (occupied or non-occupied) of each point from a taxi segment. This model first uses the identified features to train a local probabilistic classifier and then carries out a Hidden Semi-Markov Model (HSMM) for globally considering long term travel patterns. We evaluated our method with a large-scale real-world trajectory dataset generated by 600 taxis...

  20. Heliocentric interplanetary low thrust trajectory optimization program, supplement 1

    Science.gov (United States)

    Mann, F. I.; Horsewood, J. L.

    1974-01-01

    The modifications and improvements made to the HILTOP electric propulsion trajectory optimization computer program up through the end of 1974 is described. New program features include the simulation of power degradation, housekeeping power, launch asymptote declination optimization, and powered and unpowered ballistic multiple swingby missions with an optional deep space burn. The report contains the new analysis describing these features, a complete description of program input quantities, and sample cases of computer output illustrating the new program capabilities.

  1. [Home based and group based exercise programs in patients with ankylosing spondylitis: systematic review].

    Science.gov (United States)

    Lopes, S; Costa, S; Mesquita, C; Duarte, J

    2016-01-01

    Ankylosing Spondylitis (AS) is a chronic inflammatory rheumatic disease characterized by inflammation of the joints of the spine and sacroiliac and to a lesser percentage of the peripheral joints. It is a debilitating condition which reduces quality of life in patients with AS. The practice of physical therapy is recommended as non-pharmacological treatment as well as the treatment and prevention of associated deformities. To collect and summarize the available evidence in scientific databases to realize the effectiveness of home based and group based programs in patients with AS. Systematic review, where articles for the study were collected from scientific database PubMed. We have found 65 articles with publication date between January 1, 2004 and January 31, 2014. Inclusion and exclusion criteria were established to make the selection of articles to include in the study. All investigators provided their agreement in presencial meeting for a final selection, and at a later stage, the articles were read in full by the three investigators. The present systematic review includes eight randomized controlled trials. All articles show functional benefits in patients with AS subject to exercise programs in group based and / or home based. From the eight articles, 4 addressed programs conducted in home based context and 4 addressed in group based context programs. There appears to be evidence that the programs carried out based on group are more effective than those home based conducted in patients with AS. It was concluded also be advantageous to carry out home based exercise programs than the absence of any exercise program..

  2. Home based and group based exercise programs in patients with ankylosing spondylitis: systematic review

    Directory of Open Access Journals (Sweden)

    Sofia Lopes

    2016-04-01

    Full Text Available Introduction: Ankylosing Spondylitis (AS is a chronic inflammatory rheumatic disease characterized by inflammation of the joints of the spine and sacroiliac and to a lesser percentage of the peripheral joints. It is a debilitating condition which reduces quality of life in patients with AS. The practice of physical therapy is recommended as non-pharmacological treatment as well as the treatment and prevention of associated deformities. Objective: To collect and summarize the available evidence in scientific databases to realize the effectiveness of home based and group based programs in patients with AS. Methods: Systematic review, where articles for the study were collected from scientific database PubMed. We have found 65 articles with publication date between January 1, 2004 and January 31, 2014. Inclusion and exclusion criteria were established to make the selection of articles to include in the study. All investigators provided their agreement in presencial meeting for a final selection, and at a later stage, the articles were read in full by the three investigators. Results: The present systematic review includes eight randomized controlled trials. All articles show functional benefits in patients with AS subject to exercise programs in group based and / or home based. From the eight articles, 4 addressed programs conducted in home based context and 4 addressed in group based context programs. Conclusion: There appears to be evidence that the programs carried out based on group are more effective than those home based conducted in patients with AS. It was concluded also be advantageous to carry out home based exercise programs than the absence of any exercise program.

  3. Characterizing long-term patterns of weight change in China using latent class trajectory modeling.

    Directory of Open Access Journals (Sweden)

    Lauren Paynter

    Full Text Available Over the past three decades, obesity-related diseases have increased tremendously in China, and are now the leading causes of morbidity and mortality. Patterns of weight change can be used to predict risk of obesity-related diseases, increase understanding of etiology of disease risk, identify groups at particularly high risk, and shape prevention strategies.Latent class trajectory modeling was used to compute weight change trajectories for adults aged 18 to 66 using the China Health and Nutrition Survey (CHNS data (n = 12,611. Weight change trajectories were computed separately for males and females by age group at baseline due to differential age-related patterns of weight gain in China with urbanization. Generalized linear mixed effects models examined the association between weight change trajectories and baseline characteristics including urbanicity, BMI category, age, and year of study entry.Trajectory classes were identified for each of six age-sex subgroups corresponding to various degrees of weight loss, maintenance and weight gain. Baseline BMI status was a significant predictor of trajectory membership for all age-sex subgroups. Baseline overweight/obesity increased odds of following 'initial loss with maintenance' trajectories. We found no significant association between baseline urbanization and trajectory membership after controlling for other covariates.Trajectory analysis identified patterns of weight change for age by gender groups. Lack of association between baseline urbanization status and trajectory membership suggests that living in a rural environment at baseline was not protective. Analyses identified age-specific nuances in weight change patterns, pointing to the importance of subgroup analyses in future research.

  4. A heretical view on linear Regge trajectories

    CERN Document Server

    Diakonov, D; Diakonov, Dmitri; Petrov, Victor

    2003-01-01

    We discuss a possibility that linear Regge trajectories originate not from gluonic strings connecting quarks, as it is usually assumed, but from pion excitations of light hadrons. From this point of view, at large angular momenta both baryons and mesons lying on linear Regge trajectories are slowly rotating thick strings of pion field, giving rise to a universal slope computable from the pion decay constant. The finite resonance widths are mainly due to the semiclassical radiation of pion fields by the rotating elongated chiral solitons. Quantum fluctuations about the soliton determine a string theory which, being quantized, gives the quantum numbers for Regge trajectories.

  5. Estimation of motility parameters from trajectory data

    DEFF Research Database (Denmark)

    Vestergaard, Christian L.; Pedersen, Jonas Nyvold; Mortensen, Kim I.;

    2015-01-01

    Given a theoretical model for a self-propelled particle or micro-organism, how does one optimally determine the parameters of the model from experimental data in the form of a time-lapse recorded trajectory? For very long trajectories, one has very good statistics, and optimality may matter little....... However, for biological micro-organisms, one may not control the duration of recordings, and then optimality can matter. This is especially the case if one is interested in individuality and hence cannot improve statistics by taking population averages over many trajectories. One can learn much about...

  6. Helicopter trajectory planning using optimal control theory

    Science.gov (United States)

    Menon, P. K. A.; Cheng, V. H. L.; Kim, E.

    1988-01-01

    A methodology for optimal trajectory planning, useful in the nap-of-the-earth guidance of helicopters, is presented. This approach uses an adjoint-control transformation along with a one-dimensional search scheme for generating the optimal trajectories. In addition to being useful for helicopter nap-of-the-earth guidance, the trajectory planning solution is of interest in several other contexts, such as robotic vehicle guidance and terrain-following guidance for cruise missiles and aircraft. A distinguishing feature of the present research is that the terrain constraint and the threat envelopes are incorporated in the equations of motion. Second-order necessary conditions are examined.

  7. Evaluating Trajectory Queries over Imprecise Location Data

    DEFF Research Database (Denmark)

    Xie, Scott, Xike; Cheng, Reynold; Yiu, Man Lung

    2012-01-01

    Trajectory queries, which retrieve nearby objects for every point of a given route, can be used to identify alerts of potential threats along a vessel route, or monitor the adjacent rescuers to a travel path. However, the locations of these objects (e.g., threats, succours) may not be precisely......, the query is quite time-consuming, since all the points on the trajectory are considered. In this paper, we study how to efficiently evaluate trajectory queries over imprecise location data, by proposing a new concept called the u-bisector. In general, the u-bisector is an extension of bisector to handle...

  8. Designing for interaction: Six steps to designing computer-supported group-based learning

    OpenAIRE

    2004-01-01

    At present, the design of computer-supported group-based learning (CS)GBL) is often based on subjective decisions regarding tasks, pedagogy and technology, or concepts such as ‘cooperative learning’ and ‘collaborative learning’. Critical review reveals these concepts as insufficiently substantial to serve as a basis for (CS)GBL design. Furthermore, the relationship between outcome and group interaction is rarely specified a priori. Thus, there is a need for a more systematic approach to desig...

  9. Psychiatric hospital nursing staff's experiences of participating in group-based clinical supervision:

    DEFF Research Database (Denmark)

    Buus, Niels; Angel, Sanne; Traynor, Michael

    2010-01-01

    Group-based clinical supervision is commonly offered as a stress-reducing intervention in psychiatric settings, but nurses often feel ambivalent about participating. This study aimed at exploring psychiatric nurses' experiences of participating in groupbased supervision and identifying psychosocial...... reasons for their ambivalence. Semi-structured interviews were conducted with 22 psychiatric nurses at a Danish university hospital. The results indicated that participation in clinical supervision was difficult for the nurses because of an uncomfortable exposure to the professional community. The sense...... of exposure was caused by the particular interactional organisation during the sessions, which brought to light pre-existing but covert conflicts among the nurses....

  10. Intergroup consensus/disagreement in support of group-based hierarchy: an examination of socio-structural and psycho-cultural factors.

    Science.gov (United States)

    Lee, I-Ching; Pratto, Felicia; Johnson, Blair T

    2011-11-01

    A meta-analysis examined the extent to which socio-structural and psycho-cultural characteristics of societies correspond with how much gender and ethnic/racial groups differ on their support of group-based hierarchy. Robustly, women opposed group-based hierarchy more than men did, and members of lower power ethnic/racial groups opposed group-based hierarchy more than members of higher power ethnic/racial groups did. As predicted by social dominance theory, gender differences were larger, more stable, and less variable from sample to sample than differences between ethnic/racial groups. Subordinate gender and ethnic/racial group members disagreed more with dominants in their views of group-based hierarchy in societies that can be considered more liberal and modern (e.g., emphasizing individualism and change from traditions), as well as in societies that enjoyed greater gender equality. The relations between gender and ethnic/racial groups are discussed, and implications are developed for social dominance theory, social role theory, biosocial theory, social identity theory, system justification theory, realistic group conflict theory, and relative deprivation theory. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

  11. Intergroup Consensus/Disagreement in Support of Group Based Hierarchy: An Examination of Socio-Structural and Psycho-Cultural Factors

    Science.gov (United States)

    Lee, I-Ching; Pratto, Felicia; Johnson, Blair T.

    2011-01-01

    A meta-analysis examined the extent to which socio-structural and psycho-cultural characteristics of societies correspond with how much gender and ethnic/racial groups differ on their support of group-based hierarchy. Robustly, women opposed group-based hierarchy more than men did and members of lower-power ethnic/racial groups opposed group-based hierarchy more than members of higher-power ethnic/racial groups. As predicted by social dominance theory, gender differences were larger, more stable, and less variable from sample to sample than differences between ethnic/racial groups. Subordinate gender and ethnic/racial group members disagreed more with dominants in their views of group-based hierarchy in societies that can be considered more liberal and modern (e.g., emphasizing individualism and change from traditions), as well as in societies that enjoyed greater gender equality. The relations between gender and ethnic/racial groups are discussed and implications are developed for social dominance theory, social role theory and biosocial theory, social identity theory, system justification theory, realistic group conflict theory and relative deprivation theory. PMID:22023142

  12. Trajectory Design for the Transiting Exoplanet Survey Satellite

    Science.gov (United States)

    Dichmann, Donald J.; Parker, Joel J. K.; Williams, Trevor W.; Mendelsohn, Chad R.

    2014-01-01

    The Transiting Exoplanet Survey Satellite (TESS) is a National Aeronautics and Space Administration (NASA) mission, scheduled to be launched in 2017. TESS will travel in a highly eccentric orbit around Earth, with initial perigee radius near 17 Earth radii (Re) and apogee radius near 59 Re. The orbit period is near 2:1 resonance with the Moon, with apogee nearly 90 degrees out-of-phase with the Moon, in a configuration that has been shown to be operationally stable. TESS will execute phasing loops followed by a lunar flyby, with a final maneuver to achieve 2:1 resonance with the Moon. The goals of a resonant orbit with long-term stability, short eclipses and limited oscillations of perigee present significant challenges to the trajectory design. To rapidly assess launch opportunities, we adapted the Schematics Window Methodology (SWM76) launch window analysis tool to assess the TESS mission constraints. To understand the long-term dynamics of such a resonant orbit in the Earth-Moon system we employed Dynamical Systems Theory in the Circular Restricted 3-Body Problem (CR3BP). For precise trajectory analysis we use a high-fidelity model and multiple shooting in the General Mission Analysis Tool (GMAT) to optimize the maneuver delta-V and meet mission constraints. Finally we describe how the techniques we have developed can be applied to missions with similar requirements. Keywords: resonant orbit, stability, lunar flyby, phasing loops, trajectory optimization

  13. Augmenting Parametric Optimal Ascent Trajectory Modeling with Graph Theory

    Science.gov (United States)

    Dees, Patrick D.; Zwack, Matthew R.; Edwards, Stephen; Steffens, Michael

    2016-01-01

    into Conceptual and Pre-Conceptual design, knowledge of the effects originating from changes to the vehicle must be calculated. In order to do this, a model capable of quantitatively describing any vehicle within the entire design space under consideration must be constructed. This model must be based upon analysis of acceptable fidelity, which in this work comes from POST. Design space interrogation can be achieved with surrogate modeling, a parametric, polynomial equation representing a tool. A surrogate model must be informed by data from the tool with enough points to represent the solution space for the chosen number of variables with an acceptable level of error. Therefore, Design Of Experiments (DOE) is used to select points within the design space to maximize information gained on the design space while minimizing number of data points required. To represent a design space with a non-trivial number of variable parameters the number of points required still represent an amount of work which would take an inordinate amount of time via the current paradigm of manual analysis, and so an automated method was developed. The best practices of expert trajectory analysts working within NASA Marshall's Advanced Concepts Office (ACO) were implemented within a tool called multiPOST. These practices include how to use the output data from a previous run of POST to inform the next, determining whether a trajectory solution is feasible from a real-world perspective, and how to handle program execution errors. The tool was then augmented with multiprocessing capability to enable analysis on multiple trajectories simultaneously, allowing throughput to scale with available computational resources. In this update to the previous work the authors discuss issues with the method and solutions.

  14. LINEAR LATTICE AND TRAJECTORY RECONSTRUCTION AND CORRECTION AT FAST LINEAR ACCELERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Romanov, A. [Fermilab; Edstrom, D. [Fermilab; Halavanau, A. [Northern Illinois U.

    2017-07-16

    The low energy part of the FAST linear accelerator based on 1.3 GHz superconducting RF cavities was successfully commissioned [1]. During commissioning, beam based model dependent methods were used to correct linear lattice and trajectory. Lattice correction algorithm is based on analysis of beam shape from profile monitors and trajectory responses to dipole correctors. Trajectory responses to field gradient variations in quadrupoles and phase variations in superconducting RF cavities were used to correct bunch offsets in quadrupoles and accelerating cavities relative to their magnetic axes. Details of used methods and experimental results are presented.

  15. Trajectory Design to Mitigate Risk on the Transiting Exoplanet Survey Satellite (TESS) Mission

    Science.gov (United States)

    Dichmann, Donald

    2016-01-01

    The Transiting Exoplanet Survey Satellite (TESS) will employ a highly eccentric Earth orbit, in 2:1 lunar resonance, reached with a lunar flyby preceded by 3.5 phasing loops. The TESS mission has limited propellant and several orbit constraints. Based on analysis and simulation, we have designed the phasing loops to reduce delta-V and to mitigate risk due to maneuver execution errors. We have automated the trajectory design process and use distributed processing to generate and to optimize nominal trajectories, check constraint satisfaction, and finally model the effects of maneuver errors to identify trajectories that best meet the mission requirements.

  16. Regularities in hadron systematics, Regge trajectories and a string quark model

    Energy Technology Data Exchange (ETDEWEB)

    Chekanov, S.V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Levchenko, B.B. [Moscow State Univ. (Russian Federation). Skobeltsyn Inst. of Nuclear Physics

    2006-08-15

    An empirical principle for the construction of a linear relationship between the total angular momentum and squared-mass of baryons is proposed. In order to examine linearity of the trajectories, a rigorous least-squares regression analysis was performed. Unlike the standard Regge-Chew-Frautschi approach, the constructed trajectories do not have non-linear behaviour. A similar regularity may exist for lowest-mass mesons. The linear baryonic trajectories are well described by a semi-classical picture based on a spinning relativistic string with tension. The obtained numerical solution of this model was used to extract the (di)quark masses. (orig.)

  17. Fatigue trajectories during the first 8 months after breast cancer diagnosis

    DEFF Research Database (Denmark)

    Bødtcher, Hanne; Bidstrup, Pernille Envold; Andersen, Ingelise;

    2015-01-01

    Purpose The objective of this study was to identify distinct groups of fatigue trajectories among women with breast cancer and to evaluate whether age, anxiety symptoms, physical activity, and type of treatment were associated with belonging to the most adverse fatigue group. Methods Women...... scheduled for breast cancer surgery at Copenhagen University Hospital, Denmark, were consecutively invited to participate in the study (n = 424), resulting in 290 women included in the analyses. Semiparametric group-based mixture modeling was used to identify distinct trajectories of fatigue assessed......-fatigue group. Conclusions The results show that one-fifth of women with breast cancer experience continuously high fatigue up to 8 months after surgery and may have been more anxious and physically inactive. This knowledge is important in targeting interventions to women with fatigue throughout their treatment...

  18. Parenting styles and body mass index trajectories from adolescence to adulthood.

    Science.gov (United States)

    Fuemmeler, Bernard F; Yang, Chongming; Costanzo, Phil; Hoyle, Rick H; Siegler, Ilene C; Williams, Redford B; Ostbye, Truls

    2012-07-01

    Parenting styles such as authoritarian, disengaged, or permissive are thought to be associated with greater adolescent obesity risk than an authoritative style. This study assessed the relationship between parenting styles and changes in body mass index (BMI) from adolescence to young adulthood. The study included self-reported data from adolescents in the National Longitudinal Study of Adolescent Health. Factor mixture modeling, a data-driven approach, was used to classify participants into parenting style groups based on measures of acceptance and control. Latent growth modeling (LGM) identified patterns of developmental changes in BMI. After a number of potential confounders were controlled for, parenting style variables were entered as predictors of BMI trajectories. Analyses were also conducted for male and female individuals of 3 racial-ethnic groups (Hispanic, black, white) to assess whether parenting styles were differentially associated with BMI trajectories in these 6 groups. Parenting styles were classified into 4 groups: authoritarian, disengaged, permissive, and balanced. Compared with the balanced parenting style, authoritarian and disengaged parenting styles were associated with a less steep average BMI increase (linear slope) over time, but also less leveling off (quadratic) of BMI over time. Differences in BMI trajectories were observed for various genders and races, but the differences did not reach statistical significance. Adolescents who reported having parents with authoritarian or disengaged parenting styles had greater increases in BMI as they transitioned to young adulthood despite having a lower BMI trajectory through adolescence.

  19. Trajectories of Delinquency from Age 14 to 23 in the National Longitudinal Survey of Youth Sample.

    Science.gov (United States)

    Murphy, Debra A; Brecht, Mary-Lynn; Huang, David; Herbeck, Diane M

    2012-03-01

    This study utilized data from the National Longitudinal Survey of Youth to investigate risk trajectories for delinquency and factors associated with different trajectories, particularly substance use. The sample (N = 8,984) was 49% female. A group-based trajectory model was applied, which identified four distinct trajectories for both males and females: (1) a High group with delinquency rates consistently higher than other groups, with some decrease across the age range; (2) a Decreased group, beginning at high levels with substantial decrease to near zero; (3) a Moderate group experiencing some decline but remaining at moderate rates of delinquency through most of the age range; and (4) a consistently Low group, having low rates of delinquency declining to near zero by mid- to late-teens. The Low group was distinguished by several protective factors, including higher rates of maternal authoritative parenting style, possible lower acculturation (higher rates of non-English spoken at home), higher rates of religious activity, later substance use initiation, lower rates of early delinquent activity, less early experience with neighborhood or personal violence, and higher rates of perceiving penalty for wrongdoing. Conversely, the High group was characterized by several vulnerability factors-essentially the converse of the protective factors above.

  20. Parenting Styles and Body Mass Index Trajectories From Adolescence to Adulthood

    Science.gov (United States)

    Fuemmeler, Bernard F.; Yang, Chongming; Costanzo, Phil; Hoyle, Rick H.; Ph.D.; Siegler, Ilene C.; Williams, Redford B.; Østbye, Truls

    2013-01-01

    Objective Parenting styles such as authoritarian, disengaged, or permissive are thought to be associated with greater adolescent obesity risk than an authoritative style. This study assessed the relationship between parenting styles and changes in body mass index (BMI) from adolescence to young adulthood. Methods The study included self-reported data from adolescents in the National Longitudinal Study of Adolescent Health. Factor mixture modeling, a data-driven approach, was used to classify participants into parenting style groups based on measures of acceptance and control. Latent growth modeling (LGM) identified patterns of developmental changes in BMI. After a number of potential cofounders were controlled for, parenting style variables were entered as predictors of BMI trajectories. Analyses were also conducted for males and females of three racial/ethnic groups (Hispanic, black, white) to assess whether parenting styles were differentially associated with BMI trajectories in these 6 groups. Results Parenting styles were classified into 4 groups: authoritarian, disengaged, permissive, and balanced. Compared with the balanced parenting style, authoritarian and disengaged parenting styles were associated with a less steep average BMI increase (linear slope) over time, but also less leveling off (quadratic) of BMI over time. Differences in BMI trajectories were observed for various genders and races, but the differences did not reach statistical significance. Conclusions Adolescents who reported having parents with authoritarian or disengaged parenting styles had greater increases in BMI as they transitioned to young adulthood despite having a lower BMI trajectory through adolescence. PMID:22545979