WorldWideScience

Sample records for modeling small movements

  1. Evaluation model of reinforcement structures of Small mass movement

    Directory of Open Access Journals (Sweden)

    Gustavo Antonio Piazza

    2015-04-01

    Full Text Available Mass movements can be the result of elevated precipitation events and inadequate policies of land use. This study aims at diagnosing the performance of a hillside stabilization structure that suffered a landslide in the meteorological event at the Itajaí Valley in 2008, and to propose a simple method for evaluating reinforcement structures of small mass movement. The study area is located at BR–470 – km 45, near to the city limit of Gaspar and Blumenau, in Santa Catarina, South Brazil. Tests were performed to determine the infiltration rate and soil moisture, as well as a survey of the floristic composition and slope. The mass movement still takes place and the stabilization structure is compromised. The use of gabion wall and other geotechnical techniques for environmental recovery were insufficient to provide the hillside stabilization. To a greater efficiency we suggest: slope reduction; soil compaction; suitable planting species (ecologic succession; and implementation of a comprehensive drainage system.

  2. Edge effect modeling of small tool polishing in planetary movement

    Science.gov (United States)

    Li, Qi-xin; Ma, Zhen; Jiang, Bo; Yao, Yong-sheng

    2018-03-01

    As one of the most challenging problems in Computer Controlled Optical Surfacing (CCOS), the edge effect greatly affects the polishing accuracy and efficiency. CCOS rely on stable tool influence function (TIF), however, at the edge of the mirror surface,with the grinding head out of the mirror ,the contact area and pressure distribution changes, which resulting in a non-linear change of TIF, and leads to tilting or sagging at the edge of the mirror. In order reduce the adverse effects and improve the polishing accuracy and efficiency. In this paper, we used the finite element simulation to analyze the pressure distribution at the mirror edge and combined with the improved traditional method to establish a new model. The new method fully considered the non-uniformity of pressure distribution. After modeling the TIFs in different locations, the description and prediction of the edge effects are realized, which has a positive significance on the control and suppression of edge effects

  3. A mathematical model for the peristaltic flow of chyme movement in small intestine.

    Science.gov (United States)

    Tripathi, Dharmendra

    2011-10-01

    A mathematical model based on viscoelastic fluid (fractional Oldroyd-B model) flow is considered for the peristaltic flow of chyme in small intestine, which is assumed to be in the form of an inclined cylindrical tube. The peristaltic flow of chyme is modeled more realistically by assuming that the peristaltic rush wave is a sinusoidal wave, which propagates along the tube. The governing equations are simplified by making the assumptions of long wavelength and low Reynolds number. Analytical approximate solutions of problem are obtained by using homotopy analysis method and convergence of the obtained series solution is properly checked. For the realistic values of the emerging parameters such as fractional parameters, relaxation time, retardation time, Reynolds number, Froude number and inclination of tube, the numerical results for the pressure difference and the frictional force across one wavelength are computed and discussed the roles played by these parameters during the peristaltic flow. On the basis of this study, it is found that the first fractional parameter, relaxation time and Froude number resist the movement of chyme, while, the second fractional parameter, retardation time, Reynolds number and inclination of tube favour the movement of chyme through the small intestine during pumping. It is further revealed that size of trapped bolus reduces with increasing the amplitude ratio whereas it is unaltered with other parameters. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Modelling group dynamic animal movement

    DEFF Research Database (Denmark)

    Langrock, Roland; Hopcraft, J. Grant C.; Blackwell, Paul G.

    2014-01-01

    in non-ideal scenarios, we show that generally the estimation of models of this type is both feasible and ecologically informative. We illustrate the approach using real movement data from 11 reindeer (Rangifer tarandus). Results indicate a directional bias towards a group centroid for reindeer......Group dynamic movement is a fundamental aspect of many species' movements. The need to adequately model individuals' interactions with other group members has been recognised, particularly in order to differentiate the role of social forces in individual movement from environmental factors. However......, to date, practical statistical methods which can include group dynamics in animal movement models have been lacking. We consider a flexible modelling framework that distinguishes a group-level model, describing the movement of the group's centre, and an individual-level model, such that each individual...

  5. Dissemination of parasites by animal movements in small ruminant farms.

    Science.gov (United States)

    Vasileiou, N G C; Fthenakis, G C; Papadopoulos, E

    2015-09-30

    The present paper discusses the spread of parasites by animal movements in small ruminant farms; it focuses in dissemination of parasitic forms that would lead to subsequent infection of sheep or goats. Systems of small ruminant production involve a component of animal movement (e.g., grazing) as part of routine husbandry, which favors spread of parasitic forms; that refers mainly to parasites of the digestive system (nematodes, trematodes, cestodes, protozoa), as well as helminthes of the respiratory system, although dissemination of the various parasitic forms in the environment would not always result to subsequent infection; external parasites may also be disseminated during movements, e.g., to inhabit wooden poles used in fencing. New livestock into a farm constitutes a biosecurity hazard and the most common means to introducing new parasitic pathogens into a farm; in contemporary small ruminant health management, this contributes in dissemination of anthelmintic resistant parasitic strains; other parasitic disease agents (e.g., mange mites, ticks) may also be spread into a farm that way. Often, especially in small scale farming, visits of rams or bucks take place from one farm to another during the mating season; in such cases, ectoparasites (e.g., mange mites) can be disseminated through direct contact of animals, as well other pathogens (e.g., Toxoplasma gondii, Neospora caninum) via the semen. During transportation of sheep/goats, parasitic forms can also spread, as well as during movement of sheep or goats to slaughterhouses, in which case dogs present in these places would contribute to their dissemination. Spread of life forms of various parasites can also occur from animal species present in the environment of sheep or goats; these include animals present within a farm, stray dogs roaming around a farm (e.g., for spread of Multiceps multiceps, Echinococcus granulosus, Taenia hydatigena, N. caninum), cats commanding the environment of a farm (e.g., for

  6. Mechanistic movement models to understand epidemic spread.

    Science.gov (United States)

    Fofana, Abdou Moutalab; Hurford, Amy

    2017-05-05

    An overlooked aspect of disease ecology is considering how and why animals come into contact with one and other resulting in disease transmission. Mathematical models of disease spread frequently assume mass-action transmission, justified by stating that susceptible and infectious hosts mix readily, and foregoing any detailed description of host movement. Numerous recent studies have recorded, analysed and modelled animal movement. These movement models describe how animals move with respect to resources, conspecifics and previous movement directions and have been used to understand the conditions for the occurrence and the spread of infectious diseases when hosts perform a type of movement. Here, we summarize the effect of the different types of movement on the threshold conditions for disease spread. We identify gaps in the literature and suggest several promising directions for future research. The mechanistic inclusion of movement in epidemic models may be beneficial for the following two reasons. Firstly, the estimation of the transmission coefficient in an epidemic model is possible because animal movement data can be used to estimate the rate of contacts between conspecifics. Secondly, unsuccessful transmission events, where a susceptible host contacts an infectious host but does not become infected can be quantified. Following an outbreak, this enables disease ecologists to identify 'near misses' and to explore possible alternative epidemic outcomes given shifts in ecological or immunological parameters.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'. © 2017 The Author(s).

  7. An information maximization model of eye movements

    Science.gov (United States)

    Renninger, Laura Walker; Coughlan, James; Verghese, Preeti; Malik, Jitendra

    2005-01-01

    We propose a sequential information maximization model as a general strategy for programming eye movements. The model reconstructs high-resolution visual information from a sequence of fixations, taking into account the fall-off in resolution from the fovea to the periphery. From this framework we get a simple rule for predicting fixation sequences: after each fixation, fixate next at the location that minimizes uncertainty (maximizes information) about the stimulus. By comparing our model performance to human eye movement data and to predictions from a saliency and random model, we demonstrate that our model is best at predicting fixation locations. Modeling additional biological constraints will improve the prediction of fixation sequences. Our results suggest that information maximization is a useful principle for programming eye movements.

  8. Modeling animal movements using stochastic differential equations

    Science.gov (United States)

    Haiganoush K. Preisler; Alan A. Ager; Bruce K. Johnson; John G. Kie

    2004-01-01

    We describe the use of bivariate stochastic differential equations (SDE) for modeling movements of 216 radiocollared female Rocky Mountain elk at the Starkey Experimental Forest and Range in northeastern Oregon. Spatially and temporally explicit vector fields were estimated using approximating difference equations and nonparametric regression techniques. Estimated...

  9. Recruitment of small synergistic movement makes a good pianist.

    Science.gov (United States)

    Jelfs, Beth; Zhou, Shengli; Wong, Bernard K Y; Tin, Chung; Chan, Rosa H M

    2015-01-01

    Time-varying synergies from kinematic data can be used to discern fundamental patterns of movement. We show through simultaneous extraction of synergies from both novice and experienced pianists that movement common to both groups can be identified. The extracted synergies successfully allow for the majority of the variability of the data to be accounted for by a limited number of components. Furthermore, classification of the weightings representing the recruitment of each of the synergies accurately distinguishes between the piano playing of the two groups of subjects. However, the major differences between the two groups lie not in the synergies representing the majority of the variance of the data but in the recruitment of smaller synergies.

  10. The random walk model of intrafraction movement

    International Nuclear Information System (INIS)

    Ballhausen, H; Reiner, M; Kantz, S; Belka, C; Söhn, M

    2013-01-01

    The purpose of this paper is to understand intrafraction movement as a stochastic process driven by random external forces. The hypothetically proposed three-dimensional random walk model has significant impact on optimal PTV margins and offers a quantitatively correct explanation of experimental findings. Properties of the random walk are calculated from first principles, in particular fraction-average population density distributions for displacements along the principal axes. When substituted into the established optimal margin recipes these fraction-average distributions yield safety margins about 30% smaller as compared to the suggested values from end-of-fraction Gaussian fits. Stylized facts of a random walk are identified in clinical data, such as the increase of the standard deviation of displacements with the square root of time. Least squares errors in the comparison to experimental results are reduced by about 50% when accounting for non-Gaussian corrections from the random walk model. (paper)

  11. The random walk model of intrafraction movement.

    Science.gov (United States)

    Ballhausen, H; Reiner, M; Kantz, S; Belka, C; Söhn, M

    2013-04-07

    The purpose of this paper is to understand intrafraction movement as a stochastic process driven by random external forces. The hypothetically proposed three-dimensional random walk model has significant impact on optimal PTV margins and offers a quantitatively correct explanation of experimental findings. Properties of the random walk are calculated from first principles, in particular fraction-average population density distributions for displacements along the principal axes. When substituted into the established optimal margin recipes these fraction-average distributions yield safety margins about 30% smaller as compared to the suggested values from end-of-fraction gaussian fits. Stylized facts of a random walk are identified in clinical data, such as the increase of the standard deviation of displacements with the square root of time. Least squares errors in the comparison to experimental results are reduced by about 50% when accounting for non-gaussian corrections from the random walk model.

  12. MODELLING FINE SCALE MOVEMENT CORRIDORS FOR THE TRICARINATE HILL TURTLE

    Directory of Open Access Journals (Sweden)

    I. Mondal

    2016-06-01

    Full Text Available Habitat loss and the destruction of habitat connectivity can lead to species extinction by isolation of population. Identifying important habitat corridors to enhance habitat connectivity is imperative for species conservation by preserving dispersal pattern to maintain genetic diversity. Circuit theory is a novel tool to model habitat connectivity as it considers habitat as an electronic circuit board and species movement as a certain amount of current moving around through different resistors in the circuit. Most studies involving circuit theory have been carried out at small scales on large ranging animals like wolves or pumas, and more recently on tigers. This calls for a study that tests circuit theory at a large scale to model micro-scale habitat connectivity. The present study on a small South-Asian geoemydid, the Tricarinate Hill-turtle (Melanochelys tricarinata, focuses on habitat connectivity at a very fine scale. The Tricarinate has a small body size (carapace length: 127–175 mm and home range (8000–15000 m2, with very specific habitat requirements and movement patterns. We used very high resolution Worldview satellite data and extensive field observations to derive a model of landscape permeability at 1 : 2,000 scale to suit the target species. Circuit theory was applied to model potential corridors between core habitat patches for the Tricarinate Hill-turtle. The modelled corridors were validated by extensive ground tracking data collected using thread spool technique and found to be functional. Therefore, circuit theory is a promising tool for accurately identifying corridors, to aid in habitat studies of small species.

  13. Modelling Fine Scale Movement Corridors for the Tricarinate Hill Turtle

    Science.gov (United States)

    Mondal, I.; Kumar, R. S.; Habib, B.; Talukdar, G.

    2016-06-01

    Habitat loss and the destruction of habitat connectivity can lead to species extinction by isolation of population. Identifying important habitat corridors to enhance habitat connectivity is imperative for species conservation by preserving dispersal pattern to maintain genetic diversity. Circuit theory is a novel tool to model habitat connectivity as it considers habitat as an electronic circuit board and species movement as a certain amount of current moving around through different resistors in the circuit. Most studies involving circuit theory have been carried out at small scales on large ranging animals like wolves or pumas, and more recently on tigers. This calls for a study that tests circuit theory at a large scale to model micro-scale habitat connectivity. The present study on a small South-Asian geoemydid, the Tricarinate Hill-turtle (Melanochelys tricarinata), focuses on habitat connectivity at a very fine scale. The Tricarinate has a small body size (carapace length: 127-175 mm) and home range (8000-15000 m2), with very specific habitat requirements and movement patterns. We used very high resolution Worldview satellite data and extensive field observations to derive a model of landscape permeability at 1 : 2,000 scale to suit the target species. Circuit theory was applied to model potential corridors between core habitat patches for the Tricarinate Hill-turtle. The modelled corridors were validated by extensive ground tracking data collected using thread spool technique and found to be functional. Therefore, circuit theory is a promising tool for accurately identifying corridors, to aid in habitat studies of small species.

  14. Hidden Markov models: the best models for forager movements?

    Science.gov (United States)

    Joo, Rocio; Bertrand, Sophie; Tam, Jorge; Fablet, Ronan

    2013-01-01

    One major challenge in the emerging field of movement ecology is the inference of behavioural modes from movement patterns. This has been mainly addressed through Hidden Markov models (HMMs). We propose here to evaluate two sets of alternative and state-of-the-art modelling approaches. First, we consider hidden semi-Markov models (HSMMs). They may better represent the behavioural dynamics of foragers since they explicitly model the duration of the behavioural modes. Second, we consider discriminative models which state the inference of behavioural modes as a classification issue, and may take better advantage of multivariate and non linear combinations of movement pattern descriptors. For this work, we use a dataset of >200 trips from human foragers, Peruvian fishermen targeting anchovy. Their movements were recorded through a Vessel Monitoring System (∼1 record per hour), while their behavioural modes (fishing, searching and cruising) were reported by on-board observers. We compare the efficiency of hidden Markov, hidden semi-Markov, and three discriminative models (random forests, artificial neural networks and support vector machines) for inferring the fishermen behavioural modes, using a cross-validation procedure. HSMMs show the highest accuracy (80%), significantly outperforming HMMs and discriminative models. Simulations show that data with higher temporal resolution, HSMMs reach nearly 100% of accuracy. Our results demonstrate to what extent the sequential nature of movement is critical for accurately inferring behavioural modes from a trajectory and we strongly recommend the use of HSMMs for such purpose. In addition, this work opens perspectives on the use of hybrid HSMM-discriminative models, where a discriminative setting for the observation process of HSMMs could greatly improve inference performance.

  15. Hidden Markov models: the best models for forager movements?

    Directory of Open Access Journals (Sweden)

    Rocio Joo

    Full Text Available One major challenge in the emerging field of movement ecology is the inference of behavioural modes from movement patterns. This has been mainly addressed through Hidden Markov models (HMMs. We propose here to evaluate two sets of alternative and state-of-the-art modelling approaches. First, we consider hidden semi-Markov models (HSMMs. They may better represent the behavioural dynamics of foragers since they explicitly model the duration of the behavioural modes. Second, we consider discriminative models which state the inference of behavioural modes as a classification issue, and may take better advantage of multivariate and non linear combinations of movement pattern descriptors. For this work, we use a dataset of >200 trips from human foragers, Peruvian fishermen targeting anchovy. Their movements were recorded through a Vessel Monitoring System (∼1 record per hour, while their behavioural modes (fishing, searching and cruising were reported by on-board observers. We compare the efficiency of hidden Markov, hidden semi-Markov, and three discriminative models (random forests, artificial neural networks and support vector machines for inferring the fishermen behavioural modes, using a cross-validation procedure. HSMMs show the highest accuracy (80%, significantly outperforming HMMs and discriminative models. Simulations show that data with higher temporal resolution, HSMMs reach nearly 100% of accuracy. Our results demonstrate to what extent the sequential nature of movement is critical for accurately inferring behavioural modes from a trajectory and we strongly recommend the use of HSMMs for such purpose. In addition, this work opens perspectives on the use of hybrid HSMM-discriminative models, where a discriminative setting for the observation process of HSMMs could greatly improve inference performance.

  16. Footballers' movement behaviour during 2-, 3-, 4- and 5-a-side small-sided games

    NARCIS (Netherlands)

    Aguiar, Marco; Goncalves, Bruno; Botelho, Goreti; Lemmink, Koen; Sampaio, Jaime

    2015-01-01

    The aim of this study was to compare footballers' movement behaviour during 2-, 3-, 4- and 5-a-side small-sided games. Ten young professional players (age=18.0 +/- 0.67years) participated in 3 bouts of each small-sided games for 6min with 1min of active rest between bouts. Positional data were

  17. Analysis of Small Muscle Movement Effects on EEG Signals

    Science.gov (United States)

    2016-12-22

    Hz Emotional Stress; Creative Inspiration; Meditation Alpha 8-13 Hz Empty mind ; Closed eyes Beta 13-30 Hz Active thinking; Attention; Problem...and Training Command In Partial Fulfillment of the Requirements for the Degree of Master of Science (Computer Engineering) Erhan E YANTERI... Training and Test Data from the Rest and Activity Conditions. ..................60 Figure 4.12. Neural Network Model for Classification of Activity

  18. Reflected stochastic differential equation models for constrained animal movement

    Science.gov (United States)

    Hanks, Ephraim M.; Johnson, Devin S.; Hooten, Mevin B.

    2017-01-01

    Movement for many animal species is constrained in space by barriers such as rivers, shorelines, or impassable cliffs. We develop an approach for modeling animal movement constrained in space by considering a class of constrained stochastic processes, reflected stochastic differential equations. Our approach generalizes existing methods for modeling unconstrained animal movement. We present methods for simulation and inference based on augmenting the constrained movement path with a latent unconstrained path and illustrate this augmentation with a simulation example and an analysis of telemetry data from a Steller sea lion (Eumatopias jubatus) in southeast Alaska.

  19. Coarse-scale movement patterns of a small-bodied fish inhabiting a desert stream

    Science.gov (United States)

    Dzul, M.C.; Quist, M.C.; Dinsmore, S.J.; Gaines, D.B.; Bower, M.R.

    2013-01-01

    Located on the floor of Death Valley (CA, USA), Salt Creek harbors a single fish species, the Salt Creek pupfish, Cyprinodon salinus salinus, which has adapted to this extremely harsh environment. Salt Creek is fed by an underground spring and is comprised of numerous pools, runs, and marshes that exhibit substantial variability in temperature, salinity, and dissolved oxygen concentrations. In addition, the wetted area of Salt Creek is reduced throughout the summer months due to high rates of evaporation, with some reaches drying completely. Therefore, it seems logical that short- and long-term movement patterns may play an important role in Salt Creek pupfish population dynamics. The objective of this study was to describe coarse-scale movements of Salt Creek pupfish in Salt Creek during their breeding season from March to May. Sex ratios and length–frequency distributions varied spatially within Salt Creek, suggesting population segregation during the breeding season. Long-distance movements were generally rare, although two fish moved more than 1.2 km. Movement in upstream reaches was rare or absent, in contrast to the greater movement observed in downstream reaches (29% of recaptures). Temporal trends and demographic patterns in movement were not observed. Because the two most downstream habitats dry up in the summer, our results indicate that coarse-scale movements that re-populate downstream reaches likely occur during other times of year. Consequently, the importance of small- and large-scale movements is influenced by season. Further assessment of Salt Creek movement patterns conducted during other times of year may better illuminate long-distance movement patterns and source-sink dynamics.

  20. A functional model for characterizing long-distance movement behaviour

    Science.gov (United States)

    Buderman, Frances E.; Hooten, Mevin B.; Ivan, Jacob S.; Shenk, Tanya M.

    2016-01-01

    Advancements in wildlife telemetry techniques have made it possible to collect large data sets of highly accurate animal locations at a fine temporal resolution. These data sets have prompted the development of a number of statistical methodologies for modelling animal movement.Telemetry data sets are often collected for purposes other than fine-scale movement analysis. These data sets may differ substantially from those that are collected with technologies suitable for fine-scale movement modelling and may consist of locations that are irregular in time, are temporally coarse or have large measurement error. These data sets are time-consuming and costly to collect but may still provide valuable information about movement behaviour.We developed a Bayesian movement model that accounts for error from multiple data sources as well as movement behaviour at different temporal scales. The Bayesian framework allows us to calculate derived quantities that describe temporally varying movement behaviour, such as residence time, speed and persistence in direction. The model is flexible, easy to implement and computationally efficient.We apply this model to data from Colorado Canada lynx (Lynx canadensis) and use derived quantities to identify changes in movement behaviour.

  1. Chicago's Renaissance 2010: The Small Schools Movement Meets the Ownership Society

    Science.gov (United States)

    Ayers, William; Klonsky, Michael

    2006-01-01

    Would-be reformers need to beware of those who would co-opt the language of reform to undermine its ideals. Mr. Ayers and Mr. Klonsky examine how Chicago's Renaissance 2010 initiative has used the terms of the small schools movement to promote privatization and the erosion of public space. (Contains 5 endnotes.)

  2. Measurement and Modelling of Blast Movement to Reduce Ore ...

    African Journals Online (AJOL)

    user

    with comprehensive monitoring using high speed video and blast movement markers. 2. Develop site specific models ... The Blast Movement Monitor (BMM) is a system developed and patented by the JKMRC, University .... at Ahafo mine, the current practice was to mine to pre-blast grade boundaries (from blast hole drilling.

  3. A competitive integration model of exogenous and endogenous eye movements

    NARCIS (Netherlands)

    Meeter, M.; van der Stigchel, S.; Theeuwes, J.

    2010-01-01

    We present a model of the eye movement system in which the programming of an eye movement is the result of the competitive integration of information in the superior colliculi (SC). This brain area receives input from occipital cortex, the frontal eye fields, and the dorsolateral prefrontal cortex,

  4. MODELLING SYNERGISTIC EYE MOVEMENTS IN THE VISUAL FIELD

    Directory of Open Access Journals (Sweden)

    BARITZ Mihaela

    2015-06-01

    Full Text Available Some theoretical and practical considerations about eye movements in visual field are presented in the first part of this paper. These movements are developed into human body to be synergistic and are allowed to obtain the visual perception in 3D space. The theoretical background of the eye movements’ analysis is founded on the establishment of movement equations of the eyeball, as they consider it a solid body with a fixed point. The exterior actions, the order and execution of the movements are ensured by the neural and muscular external system and thus the position, stability and movements of the eye can be quantified through the method of reverse kinematic. The purpose of these researches is the development of a simulation model of human binocular visual system, an acquisition methodology and an experimental setup for data processing and recording regarding the eye movements, presented in the second part of the paper. The modeling system of ocular movements aims to establish the binocular synergy and limits of visual field changes in condition of ocular motor dysfunctions. By biomechanical movements of eyeball is established a modeling strategy for different sort of processes parameters like convergence, fixation and eye lens accommodation to obtain responses from binocular balance. The results of modelling processes and the positions of eye ball and axis in visual field are presented in the final part of the paper.

  5. Social network models predict movement and connectivity in ecological landscapes

    Science.gov (United States)

    Fletcher, Robert J.; Acevedo, M.A.; Reichert, Brian E.; Pias, Kyle E.; Kitchens, Wiley M.

    2011-01-01

    Network analysis is on the rise across scientific disciplines because of its ability to reveal complex, and often emergent, patterns and dynamics. Nonetheless, a growing concern in network analysis is the use of limited data for constructing networks. This concern is strikingly relevant to ecology and conservation biology, where network analysis is used to infer connectivity across landscapes. In this context, movement among patches is the crucial parameter for interpreting connectivity but because of the difficulty of collecting reliable movement data, most network analysis proceeds with only indirect information on movement across landscapes rather than using observed movement to construct networks. Statistical models developed for social networks provide promising alternatives for landscape network construction because they can leverage limited movement information to predict linkages. Using two mark-recapture datasets on individual movement and connectivity across landscapes, we test whether commonly used network constructions for interpreting connectivity can predict actual linkages and network structure, and we contrast these approaches to social network models. We find that currently applied network constructions for assessing connectivity consistently, and substantially, overpredict actual connectivity, resulting in considerable overestimation of metapopulation lifetime. Furthermore, social network models provide accurate predictions of network structure, and can do so with remarkably limited data on movement. Social network models offer a flexible and powerful way for not only understanding the factors influencing connectivity but also for providing more reliable estimates of connectivity and metapopulation persistence in the face of limited data.

  6. Social network models predict movement and connectivity in ecological landscapes.

    Science.gov (United States)

    Fletcher, Robert J; Acevedo, Miguel A; Reichert, Brian E; Pias, Kyle E; Kitchens, Wiley M

    2011-11-29

    Network analysis is on the rise across scientific disciplines because of its ability to reveal complex, and often emergent, patterns and dynamics. Nonetheless, a growing concern in network analysis is the use of limited data for constructing networks. This concern is strikingly relevant to ecology and conservation biology, where network analysis is used to infer connectivity across landscapes. In this context, movement among patches is the crucial parameter for interpreting connectivity but because of the difficulty of collecting reliable movement data, most network analysis proceeds with only indirect information on movement across landscapes rather than using observed movement to construct networks. Statistical models developed for social networks provide promising alternatives for landscape network construction because they can leverage limited movement information to predict linkages. Using two mark-recapture datasets on individual movement and connectivity across landscapes, we test whether commonly used network constructions for interpreting connectivity can predict actual linkages and network structure, and we contrast these approaches to social network models. We find that currently applied network constructions for assessing connectivity consistently, and substantially, overpredict actual connectivity, resulting in considerable overestimation of metapopulation lifetime. Furthermore, social network models provide accurate predictions of network structure, and can do so with remarkably limited data on movement. Social network models offer a flexible and powerful way for not only understanding the factors influencing connectivity but also for providing more reliable estimates of connectivity and metapopulation persistence in the face of limited data.

  7. Investigating the Process of Process Modeling with Eye Movement Analysis

    OpenAIRE

    Pinggera, Jakob; Furtner, Marco; Martini, Markus; Sachse, Pierre; Reiter, Katharina; Zugal, Stefan; Weber, Barbara

    2015-01-01

    Research on quality issues of business process models has recently begun to explore the process of creating process models by analyzing the modeler's interactions with the modeling environment. In this paper we aim to complement previous insights on the modeler's modeling behavior with data gathered by tracking the modeler's eye movements when engaged in the act of modeling. We present preliminary results and outline directions for future research to triangulate toward a more comprehensive un...

  8. Small animal models of xenotransplantation.

    Science.gov (United States)

    Wang, Hao

    2012-01-01

    Organ transplantation has become a successful and acceptable treatment for end-stage organ failure. Such success has allowed transplant patients to resume a normal lifestyle. The demands for transplantation have been steadily increasing, as more patients and new diseases are being deemed eligible for treatment via transplantation. However, it is clear that human organs will never meet the increasing demand of transplantation. Therefore, scientists must continue to pursue alternative therapies and explore new treatments to meet the growing demand for the limited number of organs available. Transplanting organs from animals into humans (xenotransplantation) is one such therapy. The observed enthusiasm for xenotransplantation, irrespective of the severe shortage of human organs and tissues available for transplantation, can be said to stem from at least two factors. First, there is the possibility that animal organs and tissues might be less susceptible than those of humans to the recurrence of disease processes. Second, a xenograft might be used as a vehicle for introducing novel genes or biochemical processes which could be of therapeutic value for the transplant recipient.To date, millions of lives have been saved by organ transplantation. These remarkable achievements would have been impossible without experimental transplantation research in animal models. Presently, more than 95% of organ transplantation research projects are carried out using rodents, such as rats and mice. The key factor to ensure the success of these experiments lies in state-of-the art experimental surgery. Small animal models offer unique advantages for the mechanistic study of xenotransplantation rejection. Currently, multiple models have been developed for investigating the different stages of immunological barriers in xenotransplantation. In this chapter, we describe six valuable small animal models that have been used in xenotransplantation research. The methodology for the small animal

  9. Effect of slow, small movement on the vibration-evoked kinesthetic illusion.

    Science.gov (United States)

    Cordo, P J; Gurfinkel, V S; Brumagne, S; Flores-Vieira, C

    2005-12-01

    The study reported in this paper investigated how vibration-evoked illusions of joint rotation are influenced by slow (0.3 degrees /s), small (2-4 degrees ) passive rotation of the joint. Normal human adults (n=15) matched the perceived position of the left ("reference") arm with the right ("matching") arm while vibration (50 pps, 0.5 mm) was applied for 30 s to the relaxed triceps brachii of the reference arm. Both arms were constrained to rotate horizontally at the elbow. Three experimental conditions were investigated: (1) vibration of the stationary reference arm, (2) slow, small passive extension or flexion of the reference arm during vibration, and (3) slow, small passive extension or flexion of the reference arm without vibration. Triceps brachii vibration at 50 pps induced an illusion of elbow flexion. The movement illusion began after several seconds, relatively fast to begin with and gradually slowing down to a stop. On average, triceps vibration produced illusory motion at an average latency of 6.3 s, amplitude of 9.7 degrees , velocity of 0.6 degrees /s, and duration of 16.4 s. During vibration, slow, small ( approximately 0.3 degrees /s, 1.3 degrees ) passive rotations of the joint dramatically enhanced, stopped, or reversed the direction of illusory movement, depending on the direction of the passive joint rotation. However, the subjects' perceptions of these passive elbow rotations were exaggerated: 2-3 times the size of the actual movement. In the absence of vibration, the subjects accurately reproduced these passive joint rotations. We discuss whether the exaggerated perception of slow, small movement during vibration is better explained by contributions of non muscle spindle Ia afferents or by changes in the mechanical transmission of vibration to the receptor.

  10. Hidden Markov modelling of movement data from fish

    DEFF Research Database (Denmark)

    Pedersen, Martin Wæver

    Movement data from marine animals tagged with electronic tags are becoming increasingly diverse and plentiful. This trend entails a need for statistical methods that are able to filter the observations to extract the ecologically relevant content. This dissertation focuses on the development...... and application of hidden Markov models (HMMs) for analysis of movement data from sh. The main contributions are represented by six scientific publications. Estimation of animal location from uncertain and possibly indirect observations is the starting point of most movement data analyses. In this work a discrete...... the behaviour of the animal. With the extended model can migratory and resident movement behaviour be related to geographical regions. For population inference multiple individual state-space analyses can be interconnected using mixed effects modelling. This framework provides parameter estimates...

  11. Eye Movement Abnormalities in Multiple Sclerosis: Pathogenesis, Modeling, and Treatment

    Directory of Open Access Journals (Sweden)

    Alessandro Serra

    2018-02-01

    Full Text Available Multiple sclerosis (MS commonly causes eye movement abnormalities that may have a significant impact on patients’ disability. Inflammatory demyelinating lesions, especially occurring in the posterior fossa, result in a wide range of disorders, spanning from acquired pendular nystagmus (APN to internuclear ophthalmoplegia (INO, among the most common. As the control of eye movements is well understood in terms of anatomical substrate and underlying physiological network, studying ocular motor abnormalities in MS provides a unique opportunity to gain insights into mechanisms of disease. Quantitative measurement and modeling of eye movement disorders, such as INO, may lead to a better understanding of common symptoms encountered in MS, such as Uhthoff’s phenomenon and fatigue. In turn, the pathophysiology of a range of eye movement abnormalities, such as APN, has been clarified based on correlation of experimental model with lesion localization by neuroimaging in MS. Eye movement disorders have the potential of being utilized as structural and functional biomarkers of early cognitive deficit, and possibly help in assessing disease status and progression, and to serve as platform and functional outcome to test novel therapeutic agents for MS. Knowledge of neuropharmacology applied to eye movement dysfunction has guided testing and use of a number of pharmacological agents to treat some eye movement disorders found in MS, such as APN and other forms of central nystagmus.

  12. Forward models and state estimation in compensatory eye movements

    Directory of Open Access Journals (Sweden)

    Maarten A Frens

    2009-11-01

    Full Text Available The compensatory eye movement system maintains a stable retinal image, integrating information from different sensory modalities to compensate for head movements. Inspired by recent models of physiology of limb movements, we suggest that compensatory eye movements (CEM can be modeled as a control system with three essential building blocks: a forward model that predicts the effects of motor commands; a state estimator that integrates sensory feedback into this prediction; and, a feedback controller that translates a state estimate into motor commands. We propose a specific mapping of nuclei within the CEM system onto these control functions. Specifically, we suggest that the Flocculus is responsible for generating the forward model prediction and that the Vestibular Nuclei integrate sensory feedback to generate an estimate of current state. Finally, the brainstem motor nuclei – in the case of horizontal compensation this means the Abducens Nucleus and the Nucleus Prepositus Hypoglossi – implement a feedback controller, translating state into motor commands. While these efforts to understand the physiological control system as a feedback control system are in their infancy, there is the intriguing possibility that compensatory eye movements and targeted voluntary movements use the same cerebellar circuitry in fundamentally different ways.

  13. Modeling of human movement monitoring using Bluetooth Low Energy technology.

    Science.gov (United States)

    Mokhtari, G; Zhang, Q; Karunanithi, M

    2015-01-01

    Bluetooth Low Energy (BLE) is a wireless communication technology which can be used to monitor human movements. In this monitoring system, a BLE signal scanner scans signal strength of BLE tags carried by people, to thus infer human movement patterns within its monitoring zone. However to the extent of our knowledge one main aspect of this monitoring system which has not yet been thoroughly investigated in literature is how to build a sound theoretical model, based on tunable BLE communication parameters such as scanning time interval and advertising time interval, to enable the study and design of effective and efficient movement monitoring systems. In this paper, we proposed and developed a statistical model based on Monte-Carlo simulation, which can be utilized to assess impacts of BLE technology parameters in terms of latency and efficiency, on a movement monitoring system, and can thus benefit a more efficient system design.

  14. Movement as a critical concept in model generation to attain ...

    African Journals Online (AJOL)

    ... and provide guidelines for the operationalisation of a model as a framework of reference for nursing to facilitate the individual faced with mental health challenges as an integral part of wholeness. A model was generated to facilitate the engagement of self through movement, which contributes to and manifests in a mindful ...

  15. Modeling Uncertainty of Directed Movement via Markov Chains

    Directory of Open Access Journals (Sweden)

    YIN Zhangcai

    2015-10-01

    Full Text Available Probabilistic time geography (PTG is suggested as an extension of (classical time geography, in order to present the uncertainty of an agent located at the accessible position by probability. This may provide a quantitative basis for most likely finding an agent at a location. In recent years, PTG based on normal distribution or Brown bridge has been proposed, its variance, however, is irrelevant with the agent's speed or divergent with the increase of the speed; so they are difficult to take into account application pertinence and stability. In this paper, a new method is proposed to model PTG based on Markov chain. Firstly, a bidirectional conditions Markov chain is modeled, the limit of which, when the moving speed is large enough, can be regarded as the Brown bridge, thus has the characteristics of digital stability. Then, the directed movement is mapped to Markov chains. The essential part is to build step length, the state space and transfer matrix of Markov chain according to the space and time position of directional movement, movement speed information, to make sure the Markov chain related to the movement speed. Finally, calculating continuously the probability distribution of the directed movement at any time by the Markov chains, it can be get the possibility of an agent located at the accessible position. Experimental results show that, the variance based on Markov chains not only is related to speed, but also is tending towards stability with increasing the agent's maximum speed.

  16. Optimum force magnitude for orthodontic tooth movement: a mathematic model.

    NARCIS (Netherlands)

    Ren, Y.; Maltha, J.C.; Hof, M.A. van 't; Kuijpers-Jagtman, A.M.

    2004-01-01

    The aim of this study was to develop a mathematic model to describe the relationship between magnitude of applied force and rate of orthodontic tooth movement. Initially, data were extracted from experimental studies in dogs (beagles), in which controlled, standardized forces were used to move

  17. Home range and local movement of small mammals on the Radioactive Waste Management Complex Idaho National Engineering Laboratory Site

    International Nuclear Information System (INIS)

    Groves, C.R.

    1978-01-01

    In April 1978, a study of local movement of small mammals on the Subsurface Disposal Area (SDA) of the Radioactive Waste Management Complex (RWMC) was undertaken in conjunction with a study of rodent dispersal. Live trapping in May and June revealed a strong potential for the detection of local movement of at least four species of rodents. Information on this movement is important as each species, during burrowing, may transport radioactive waste from the point of interment to the surface. The area over which contamination may be spread, as fecal deposits or as metabolically incorporated elements, is a function of the daily movement of each animal. At least eight factors may effect size and shape of home range. These factors are discussed, techniques employed in the calculation of home range are outlined, and problems associated with live trapping and studying local movement of small mammals are considered

  18. Small is beautiful: models of small neuronal networks.

    Science.gov (United States)

    Lamb, Damon G; Calabrese, Ronald L

    2012-08-01

    Modeling has contributed a great deal to our understanding of how individual neurons and neuronal networks function. In this review, we focus on models of the small neuronal networks of invertebrates, especially rhythmically active CPG networks. Models have elucidated many aspects of these networks, from identifying key interacting membrane properties to pointing out gaps in our understanding, for example missing neurons. Even the complex CPGs of vertebrates, such as those that underlie respiration, have been reduced to small network models to great effect. Modeling of these networks spans from simplified models, which are amenable to mathematical analyses, to very complicated biophysical models. Some researchers have now adopted a population approach, where they generate and analyze many related models that differ in a few to several judiciously chosen free parameters; often these parameters show variability across animals and thus justify the approach. Models of small neuronal networks will continue to expand and refine our understanding of how neuronal networks in all animals program motor output, process sensory information and learn. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. A Simulation Model for Intra-Urban Movements.

    Directory of Open Access Journals (Sweden)

    Nimrod Serok

    Full Text Available Human mobility patterns (HMP have become of interest to a variety of disciplines. The increasing availability of empirical data enables researchers to analyze patterns of people's movements. Recent work suggested that HMP follow a Levy-flight distribution and present regularity. Here, we present an innovative agent-based model that simulates HMP for various purposes. It is based on the combination of regular movements with spatial considerations, represented by an expanded gravitation model. The agents in this model have different attributes that affect their choice of destination and the duration they stay in each location. Thus, their movement mimics real-life situations. This is a stochastic, bottom-up model, yet it yields HMP that qualitatively fit HMP empirical data in terms of individuals, as well as the entire population. Our results also correspond to real-life phenomena in terms of urban spatial dynamics, that is, the emergence of popular locations in the city due to bottom-up behavior of people. Our model is novel in being based on the assumption that HMP are space-dependent as well as follow high regularity. To our knowledge, we are the first to succeed in simulating HMP not only at the inter-city scale but also at the intra-urban one.

  20. Deriving movement properties and the effect of the environment from the Brownian bridge movement model in monkeys and birds

    NARCIS (Netherlands)

    Buchin, K.; Sijben, S.; van Loon, E.E.; Sapir, N.; Mercier, S.; Arseneau, T.J.M.; Willems, E.P.

    2015-01-01

    Background: The Brownian bridge movement model (BBMM) provides a biologically sound approximation of the movement path of an animal based on discrete location data, and is a powerful method to quantify utilization distributions. Computing the utilization distribution based on the BBMM while

  1. Unsupervised Posture Modeling Based on Spatial-Temporal Movement Features

    Science.gov (United States)

    Yan, Chunjuan

    Traditional posture modeling for human action recognition is based on silhouette segmentation, which is subject to the noise from illumination variation and posture occlusions and shadow interruptions. In this paper, we extract spatial temporal movement features from human actions and adopt unsupervised clustering method for salient posture learning. First, spatial-temporal interest points (STIPs) were extracted according to the properties of human movement, and then, histogram of gradient was built to describe the distribution of STIPs in each frame for a single pose. In addition, the training samples were clustered by non-supervised classification method. Moreover, the salient postures were modeled with GMM according to Expectation Maximization (EM) estimation. The experiment results proved that our method can effectively and accurately recognize human's action postures.

  2. DEMOGRAPHIC CHALLENGES AND STAFF MOVEMENTS MODELING IN BUSINESS ORGANIZATIONS

    Directory of Open Access Journals (Sweden)

    Vladimir I. Kuznetsov

    2013-01-01

    Full Text Available In recent years a special attention is given to various aspects and problems of development of business and steady social and economic growth of modern Russia. In this context, a big scientific and practical interest is the all-round analysis of various barriers arising on a way of this process. A significant role belongs to specific threats of formation and modeling movement of the personnel in enterprises.

  3. A novel Direct Small World network model

    Directory of Open Access Journals (Sweden)

    LIN Tao

    2016-10-01

    Full Text Available There is a certain degree of redundancy and low efficiency of existing computer networks.This paper presents a novel Direct Small World network model in order to optimize networks.In this model,several nodes construct a regular network.Then,randomly choose and replot some nodes to generate Direct Small World network iteratively.There is no change in average distance and clustering coefficient.However,the network performance,such as hops,is improved.The experiments prove that compared to traditional small world network,the degree,average of degree centrality and average of closeness centrality are lower in Direct Small World network.This illustrates that the nodes in Direct Small World networks are closer than Watts-Strogatz small world network model.The Direct Small World can be used not only in the communication of the community information,but also in the research of epidemics.

  4. Estimating movement and survival rates of a small saltwater fish using autonomous antenna receiver arrays and passive integrated transponder tags

    Science.gov (United States)

    Rudershausen, Paul J.; Buckel, Jeffery A.; Dubreuil, Todd; O'Donnell, Matthew J.; Hightower, Joseph E.; Poland, Steven J.; Letcher, Benjamin H.

    2014-01-01

    We evaluated the performance of small (12.5 mm long) passive integrated transponder (PIT) tags and custom detection antennas for obtaining fine-scale movement and demographic data of mummichog Fundulus heteroclitus in a salt marsh creek. Apparent survival and detection probability were estimated using a Cormack Jolly Seber (CJS) model fitted to detection data collected by an array of 3 vertical antennas from November 2010 to March 2011 and by a single horizontal antenna from April to August 2011. Movement of mummichogs was monitored during the period when the array of vertical antennas was used. Antenna performance was examined in situ using tags placed in wooden dowels (drones) and in live mummichogs. Of the 44 tagged fish, 42 were resighted over the 9 mo monitoring period. The in situ detection probabilities of the drone and live mummichogs were high (~80-100%) when the ambient water depth was less than ~0.8 m. Upstream and downstream movement of mummichogs was related to hourly water depth and direction of tidal current in a way that maximized time periods over which mummichogs utilized the intertidal vegetated marsh. Apparent survival was lower during periods of colder water temperatures in December 2010 and early January 2011 (median estimate of daily apparent survival = 0.979) than during other periods of the study (median estimate of daily apparent survival = 0.992). During late fall and winter, temperature had a positive effect on the CJS detection probability of a tagged mummichog, likely due to greater fish activity over warmer periods. During the spring and summer, this pattern reversed possibly due to mummichogs having reduced activity during the hottest periods. This study demonstrates the utility of PIT tags and continuously operating autonomous detection systems for tracking fish at fine temporal scales, and improving estimates of demographic parameters in salt marsh creeks that are difficult or impractical to sample with active fishing gear.

  5. A comparison of two- and three-dimensional stochastic models of regional solute movement

    Science.gov (United States)

    Shapiro, A.M.; Cvetkovic, V.D.

    1990-01-01

    Recent models of solute movement in porous media that are based on a stochastic description of the porous medium properties have been dedicated primarily to a three-dimensional interpretation of solute movement. In many practical problems, however, it is more convenient and consistent with measuring techniques to consider flow and solute transport as an areal, two-dimensional phenomenon. The physics of solute movement, however, is dependent on the three-dimensional heterogeneity in the formation. A comparison of two- and three-dimensional stochastic interpretations of solute movement in a porous medium having a statistically isotropic hydraulic conductivity field is investigated. To provide an equitable comparison between the two- and three-dimensional analyses, the stochastic properties of the transmissivity are defined in terms of the stochastic properties of the hydraulic conductivity. The variance of the transmissivity is shown to be significantly reduced in comparison to that of the hydraulic conductivity, and the transmissivity is spatially correlated over larger distances. These factors influence the two-dimensional interpretations of solute movement by underestimating the longitudinal and transverse growth of the solute plume in comparison to its description as a three-dimensional phenomenon. Although this analysis is based on small perturbation approximations and the special case of a statistically isotropic hydraulic conductivity field, it casts doubt on the use of a stochastic interpretation of the transmissivity in describing regional scale movement. However, by assuming the transmissivity to be the vertical integration of the hydraulic conductivity field at a given position, the stochastic properties of the hydraulic conductivity can be estimated from the stochastic properties of the transmissivity and applied to obtain a more accurate interpretation of solute movement. ?? 1990 Kluwer Academic Publishers.

  6. Connections for small vertex models

    Indian Academy of Sciences (India)

    In this section we prove that every biunitary matrix in BЕ2Y nЖ is equivalent to a biunitary matrix in a model form with Е3n └ 5Ж independent parameters. PROPOSITION 2.1. Any biunitary matrix W P BЕ2Y nЖ is equivalent to a matrix of the form. C. US. VS └UVC. Y where UY V are diagonal unitary matrices and CY S are ...

  7. Seasonal cues of Arctic grayling movement in a small Arctic stream: the importance of surface water connectivity

    Science.gov (United States)

    Heim, Kurt C.; Wipfli, Mark S.; Whitman, Matthew S.; Arp, Christopher D.; Adams, Jeff; Falke, Jeffrey A.

    2015-01-01

    In Arctic ecosystems, freshwater fish migrate seasonally between productive shallow water habitats that freeze in winter and deep overwinter refuge in rivers and lakes. How these movements relate to seasonal hydrology is not well understood. We used passive integrated transponder tags and stream wide antennae to track 1035 Arctic grayling in Crea Creek, a seasonally flowing beaded stream on the Arctic Coastal Plain, Alaska. Migration of juvenile and adult fish into Crea Creek peaked in June immediately after ice break-up in the stream. Fish that entered the stream during periods of high flow and cold stream temperature traveled farther upstream than those entering during periods of lower flow and warmer temperature. We used generalized linear models to relate migration of adult and juvenile fish out of Crea Creek to hydrology. Most adults migrated in late June – early July, and there was best support (Akaike weight = 0.46; w i ) for a model indicating that the rate of migration increased with decreasing discharge. Juvenile migration occurred in two peaks; the early peak consisted of larger juveniles and coincided with adult migration, while the later peak occurred shortly before freeze-up in September and included smaller juveniles. A model that included discharge, minimum stream temperature, year, season, and mean size of potential migrants was most strongly supported (w i  = 0.86). Juvenile migration rate increased sharply as daily minimum stream temperature decreased, suggesting fish respond to impending freeze-up. We found fish movements to be intimately tied to the strong seasonality of discharge and temperature, and demonstrate the importance of small stream connectivity for migratory Arctic grayling during the entire open-water period. The ongoing and anticipated effects of climate change and petroleum development on Arctic hydrology (e.g. reduced stream connectivity, earlier peak flows, increased evapotranspiration) have important implications

  8. Parametric Hidden Markov Models for Recognition and Synthesis of Movements

    DEFF Research Database (Denmark)

    Herzog, Dennis; Krüger, Volker; Grest, Daniel

    2008-01-01

    In humanoid robotics, the recognition and synthesis of parametric movements plays an extraordinary role for robot human interaction. Such a parametric movement is a movement of a particular type (semantic), for example, similar pointing movements performed at different table-top positions. For un...

  9. Antiparkinsonian Efficacy of Guanosine in Rodent Models of Movement Disorder

    Science.gov (United States)

    Massari, Caio M.; López-Cano, Marc; Núñez, Fabiana; Fernández-Dueñas, Víctor; Tasca, Carla I.; Ciruela, Francisco

    2017-01-01

    Guanosine (GUO) is a guanine-based purine nucleoside with important trophic functions and promising neuroprotective properties. Although the neuroprotective effects of GUO have been corroborated in cellular models of Parkinson’s disease (PD), its efficacy as an antiparkinsonian agent has not been fully explored in PD animal models. Accordingly, we evaluated the effectiveness of GUO in reversing motor impairments in several rodent movement disorder models, including catalepsy, tremor, and hemiparkinsonism. Our results showed that orally administered GUO antagonized reserpine-mediated catalepsy, reduced reserpine-induced tremulous jaw movements, and potentiated the number of contralateral rotations induced by L-3,4-dihydroxyphenylalanine in unilaterally 6-hydroxidopamine-lesioned rats. In addition, at 5 and 7.5 mg/kg, GUO inhibited L-DOPA-induced dyskinesia in rats chronically treated with a pro-dopaminergic agent. Overall, we describe the therapeutic potential of GUO, which may be effective not only for reversing parkinsonian motor impairments but also for reducing dyskinesia induced by treatment for PD. PMID:29046640

  10. Human Posture and Movement Prediction based on Musculoskeletal Modeling

    DEFF Research Database (Denmark)

    Farahani, Saeed Davoudabadi

    2014-01-01

    Abstract This thesis explores an optimization-based formulation, so-called inverse-inverse dynamics, for the prediction of human posture and motion dynamics performing various tasks. It is explained how this technique enables us to predict natural kinematic and kinetic patterns for human posture...... and motion using AnyBody Modeling System (AMS). AMS uses inverse dynamics to analyze musculoskeletal systems and is, therefore, limited by its dependency on input kinematics. We propose to alleviate this dependency by assuming that voluntary postures and movement strategies in humans are guided by a desire...... specifications. The model is then scaled to the desired anthropometric data by means of one of the existing scaling law in AMS. If the simulation results are to be compared with the experimental measurements, the model should be scaled to match the involved subjects. Depending on the scientific question...

  11. Damage modeling in Small Punch Test specimens

    DEFF Research Database (Denmark)

    Martínez Pañeda, Emilio; Cuesta, I.I.; Peñuelas, I.

    2016-01-01

    Ductile damage modeling within the Small Punch Test (SPT) is extensively investigated. The capabilities ofthe SPT to reliably estimate fracture and damage properties are thoroughly discussed and emphasis isplaced on the use of notched specimens. First, different notch profiles are analyzed....... Furthermore,Gurson-Tvergaard-Needleman model predictions from a top-down approach are employed to gain insightinto the mechanisms governing crack initiation and subsequent propagation in small punch experiments.An accurate assessment of micromechanical toughness parameters from the SPT...

  12. Model selection for the extraction of movement primitives

    Directory of Open Access Journals (Sweden)

    Dominik M Endres

    2013-12-01

    Full Text Available A wide range of blind source separation methods have been used in motor control research for the extraction of movement primitives from EMG and kinematic data. Popular examples are principal component analysis (PCA,independent component analysis (ICA, anechoic demixing, and the time-varying synergy model. However, choosing the parameters of these models, or indeed choosing the type of model, is often done in a heuristic fashion, driven by result expectations as much as by the data. We propose an objective criterion which allows to select the model type, number of primitives and the temporal smoothness prior. Our approach is based on a Laplace approximation to the posterior distribution of the parameters of a given blind source separation model, re-formulated as a Bayesian generative model.We first validate our criterion on ground truth data, showing that it performs at least as good as traditional model selection criteria (Bayesian information criterion, BIC and the Akaike Information Criterion (AIC. Then, we analyze human gait data, finding that an anechoic mixture model with a temporal smoothness constraint on the sources can best account for the data.

  13. Spatiotemporal modelling of marine movement data using Template Model Builder (TMB)

    DEFF Research Database (Denmark)

    Auger-Méthé, Marie; Albertsen, Christoffer Moesgaard; Jonsen, Ian D.

    2017-01-01

    Tracking of marine animals has increased exponentially in the past decade, and the resulting data could lead to an in-depth understanding of the causes and consequences of movement in the ocean. However, most common marine tracking systems are associated with large measurement errors. Accounting...... for these errors requires the use of hierarchical models, which are often difficult to fit to data. Using 3 case studies, we demonstrate that Template Model Builder (TMB), a new R package, is an accurate, efficient and flexible framework for modelling movement data. First, to demonstrate that TMB is as accurate...... tool for modelling marine movement data. We discuss how TMB’s potential reaches beyond marine movement studies...

  14. Solid modeling of fossil small mammal teeth

    Science.gov (United States)

    Marschallinger, Robert; Hofmann, Peter; Daxner-Höck, Gudrun; Ketcham, Richard A.

    2011-09-01

    This paper presents an approach to create solid models of fossil small mammal teeth using a combination of microcomputed tomography, object based image analysis and voxel modeling. Small mammal teeth, because of their durability, are widely found in Cenozioc sediments the world over and play a key role in stratigraphy as well as in researching the rapid evolution and the paleogeographic spreading of small mammals. Recent advances in microcomputed tomography make this non-destructive analysis method an ideal data source for high-resolution 3D models of fossil small animal teeth. To derive internally consistent solid models of such fossils from micro-CT imagery, we propose a combination of 3D object based image analysis and solid modeling. Incorporating paleontological expert knowledge in the image processing cycle, object based image analysis yields topologically consistent image stacks classified by the main tooth components—enamel, dentine and pulp. Forwarding these data to a voxel modeling system, they can be quantitatively analyzed in an unprecedented manner: going beyond the possibilities of the state-of-art surface models, solid models are capable of unambiguously portraying the entire object volume—teeth can be peeled by material properties, subvolumes can be extracted and automatically analyzed by Boolean operations. The proposed method, which can be flexibly extended to handle a range of paleontological and geological micro-objects, is demonstrated with two typical fossil small mammal teeth.

  15. Extending the E-Z Reader Model of Eye Movement Control to Chinese Readers

    Science.gov (United States)

    Rayner, Keith; Li, Xingshan; Pollatsek, Alexander

    2007-01-01

    Chinese readers' eye movements were simulated in the context of the E-Z Reader model, which was developed to account for the eye movements of readers of English. Despite obvious differences between English and Chinese, the model did a fairly good job of simulating the eye movements of Chinese readers. The successful simulation suggests that the…

  16. Is that really my movement? - Students' experiences of a video-supported interactive learning model for movement awareness.

    Science.gov (United States)

    Backåberg, Sofia; Gummesson, Christina; Brunt, David; Rask, Mikael

    2015-01-01

    Healthcare staff and students have a great risk of developing musculoskeletal symptoms. One cause of this is heavy load related work activities such as manual handling, in which the quality of individual work technique may play a major role. Preventive interventions and well-defined educational strategies to support movement awareness and long-lasting movement changes need to be developed. The aim of the present study was to explore nursing students' experiences of a newly developed interactive learning model for movement awareness. The learning model, which is based on a life-world perspective with focus on interpersonal interaction, has been used with 11 undergraduate students from the second and final year. Each student participated in three individual video sessions with a facilitator. Two individual interviews were carried out with each student during the learning process and one interview 12-18 months after the last session. The interviews were audio-recorded and transcribed verbatim, and a phenomenological hermeneutic method inspired by Paul Ricoeur and described by Lindseth and Norberg was used to interpret the interviews and diary notes. The interpretation resulted in three key themes and nine subthemes. The key themes were; "Obtaining better preconditions for bodily awareness," "Experiencing changes in one's own movement," and "Experiencing challenges in the learning process." The interactive learning model entails a powerful and challenging experience that develops movement awareness. The experience of meaningfulness and usefulness emerges increasingly and alternates with a feeling of discomfort. The learning model may contribute to the body of knowledge of well-defined educational strategies in movement awareness and learning in, for example, preventive interventions and ergonomic education. It may also be valuable in other practical learning situations where movement awareness is required.

  17. Is that really my movement?—Students' experiences of a video-supported interactive learning model for movement awareness

    Science.gov (United States)

    Backåberg, Sofia; Gummesson, Christina; Brunt, David; Rask, Mikael

    2015-01-01

    Healthcare staff and students have a great risk of developing musculoskeletal symptoms. One cause of this is heavy load related work activities such as manual handling, in which the quality of individual work technique may play a major role. Preventive interventions and well-defined educational strategies to support movement awareness and long-lasting movement changes need to be developed. The aim of the present study was to explore nursing students’ experiences of a newly developed interactive learning model for movement awareness. The learning model, which is based on a life-world perspective with focus on interpersonal interaction, has been used with 11 undergraduate students from the second and final year. Each student participated in three individual video sessions with a facilitator. Two individual interviews were carried out with each student during the learning process and one interview 12–18 months after the last session. The interviews were audio-recorded and transcribed verbatim, and a phenomenological hermeneutic method inspired by Paul Ricoeur and described by Lindseth and Norberg was used to interpret the interviews and diary notes. The interpretation resulted in three key themes and nine subthemes. The key themes were; “Obtaining better preconditions for bodily awareness,” “Experiencing changes in one's own movement,” and “Experiencing challenges in the learning process.” The interactive learning model entails a powerful and challenging experience that develops movement awareness. The experience of meaningfulness and usefulness emerges increasingly and alternates with a feeling of discomfort. The learning model may contribute to the body of knowledge of well-defined educational strategies in movement awareness and learning in, for example, preventive interventions and ergonomic education. It may also be valuable in other practical learning situations where movement awareness is required. PMID:26274385

  18. Is that really my movement?—Students' experiences of a video-supported interactive learning model for movement awareness

    Directory of Open Access Journals (Sweden)

    Sofia Backåberg

    2015-08-01

    Full Text Available Healthcare staff and students have a great risk of developing musculoskeletal symptoms. One cause of this is heavy load related work activities such as manual handling, in which the quality of individual work technique may play a major role. Preventive interventions and well-defined educational strategies to support movement awareness and long-lasting movement changes need to be developed. The aim of the present study was to explore nursing students’ experiences of a newly developed interactive learning model for movement awareness. The learning model, which is based on a life-world perspective with focus on interpersonal interaction, has been used with 11 undergraduate students from the second and final year. Each student participated in three individual video sessions with a facilitator. Two individual interviews were carried out with each student during the learning process and one interview 12–18 months after the last session. The interviews were audio-recorded and transcribed verbatim, and a phenomenological hermeneutic method inspired by Paul Ricoeur and described by Lindseth and Norberg was used to interpret the interviews and diary notes. The interpretation resulted in three key themes and nine subthemes. The key themes were; “Obtaining better preconditions for bodily awareness,” “Experiencing changes in one's own movement,” and “Experiencing challenges in the learning process.” The interactive learning model entails a powerful and challenging experience that develops movement awareness. The experience of meaningfulness and usefulness emerges increasingly and alternates with a feeling of discomfort. The learning model may contribute to the body of knowledge of well-defined educational strategies in movement awareness and learning in, for example, preventive interventions and ergonomic education. It may also be valuable in other practical learning situations where movement awareness is required.

  19. RAILWAY TRACK REPRESENTATION IN MATHEMATICAL MODEL OF VEHICLES MOVEMENT

    Directory of Open Access Journals (Sweden)

    M. B. Kurhan

    2017-12-01

    Full Text Available Purpose. The tasks of modeling the interaction of track and rolling stock are basic ones for most areas of mo-dern scientific research of railway transport. The compilation of the model by the principle of Lagrange d'Alembert has found a very wide application for solving the problems of rolling stock dynamics. Representation of the railway track in the model of crew movement can be implemented in several ways, which, among other things, will differ in detail. The purpose of this work is to create a methodology for representing the railway track in mathematical mo-dels of interaction with rolling stock and obtaining practical results for different characteristics and design of the track and the level of maximum speed. Methodology. The problem consists of determining such characteristics of the path as the reduced mass, the stiffness coefficient, and the dissipation coefficient. As a tool for solving this problem it was used the model of the stress-strain behavior of the railway track based on the joint use of the elastic wave propagation equations to describe the geometry of the outline of the part of the system space that is involved in the interaction at a given time and the equations of dynamic equilibrium of its deformation. This makes it possible to take into account the dynamics of the deflection of the under-rail base, which is especially important for the conditions of passenger traffic, which can be carried out at high speed. Findings. Theoretically justified stiffness and dissipation coefficients of the railway track for calculating the dynamics of rolling stock in modern models based on systems of equations in accordance with the Lagrange d'Alembert principle are obtained. The established va-lues, in contrast to those given in other sources, have a reasonable dependence on the design of the path and the speed of movement. Originality. The approaches of railroad track representation in models of rolling stock described by systems of

  20. Cytokines and VEGF Induction in Orthodontic Movement in Animal Models

    Directory of Open Access Journals (Sweden)

    M. Di Domenico

    2012-01-01

    Full Text Available Orthodontics is a branch of dentistry that aims at the resolution of dental malocclusions. The specialist carries out the treatment using intraoral or extraoral orthodontic appliances that require forces of a given load level to obtain a tooth movement in a certain direction in dental arches. Orthodontic tooth movement is dependent on efficient remodeling of periodontal ligament and alveolar bone, correlated with several biological and mechanical responses of the tissues surrounding the teeth. A periodontal ligament placed under pressure will result in bone resorption whereas a periodontal ligament under tension results in bone formation. In the primary stage of the application of orthodontic forces, an acute inflammation occurs in periodontium. Several proinflammatory cytokines are produced by immune-competent cells migrating by means of dilated capillaries. In this paper we summarize, also through the utilization of animal models, the role of some of these molecules, namely, interleukin-1β and vascular endothelial growth factor, that are some proliferation markers of osteoclasts and osteoblasts, and the macrophage colony stimulating factor.

  1. Features of microscopic pedestrian movement in a panic situation based on cellular automata model

    Science.gov (United States)

    Ibrahim, Najihah; Hassan, Fadratul Hafinaz

    2017-10-01

    Pedestrian movement is the one of the subset for the crowd management under simulation objective. During panic situation, pedestrian usually will create a microscopic movement that lead towards the self-organization. During self-organizing, the behavioral and physical factors had caused the mass effect on the pedestrian movement. The basic CA model will create a movement path for each pedestrian over a time step. However, due to the factors immerge, the CA model needs some enhancement that will establish a real simulation state. Hence, this concept paper will discuss on the enhanced features of CA model for microscopic pedestrian movement during panic situation for a better pedestrian simulation.

  2. Recording Lifetime Behavior and Movement in an Invertebrate Model

    Science.gov (United States)

    Zou, Sige; Liedo, Pablo; Altamirano-Robles, Leopoldo; Cruz-Enriquez, Janeth; Morice, Amy; Ingram, Donald K.; Kaub, Kevin; Papadopoulos, Nikos; Carey, James R.

    2011-01-01

    Characterization of lifetime behavioral changes is essential for understanding aging and aging-related diseases. However, such studies are scarce partly due to the lack of efficient tools. Here we describe and provide proof of concept for a stereo vision system that classifies and sequentially records at an extremely fine scale six different behaviors (resting, micro-movement, walking, flying, feeding and drinking) and the within-cage (3D) location of individual tephritid fruit flies by time-of-day throughout their lives. Using flies fed on two different diets, full sugar-yeast and sugar-only diets, we report for the first time their behavioral changes throughout their lives at a high resolution. We have found that the daily activity peaks at the age of 15–20 days and then gradually declines with age for flies on both diets. However, the overall daily activity is higher for flies on sugar-only diet than those on the full diet. Flies on sugar-only diet show a stronger diurnal localization pattern with higher preference to staying on the top of the cage during the period of light-off when compared to flies on the full diet. Clustering analyses of age-specific behavior patterns reveal three distinct young, middle-aged and old clusters for flies on each of the two diets. The middle-aged groups for flies on sugar-only diet consist of much younger age groups when compared to flies on full diet. This technology provides research opportunities for using a behavioral informatics approach for understanding different ways in which behavior, movement, and aging in model organisms are mutually affecting. PMID:21559058

  3. An accurate and portable eye movement detector for studying sleep in small animals.

    Science.gov (United States)

    Sánchez-López, Álvaro; Escudero, Miguel

    2015-08-01

    Although eye movements are a highly valuable variable in attempts to precisely identify different periods of the sleep-wake cycle, their indirect measurement by electrooculography is not good enough. The present article describes an accurate and portable scleral search coil that allows the detection of tonic and phasic characteristics of eye movements in free-moving animals. Six adult Wistar rats were prepared for chronic recording of electroencephalography, electromyography and eye movements using the scleral search coil technique. We developed a miniature magnetic field generator made with two coils, consisting of 35 turns and 15 mm diameter of insulated 0.2 mm cooper wire, mounted in a frame of carbon fibre. This portable scleral search coil was fixed on the head of the animal, with each magnetic coil parallel to the eye coil and at 5 mm from each eye. Eye movements detected by the portable scleral search coil were compared with those measured by a commercial scleral search coil requiring immobilizing the head of the animal. No qualitative differences were found between the two scleral search coil systems in their capabilities to detect eye movements. This innovative portable scleral search coil system is an essential tool to detect slow changes in eye position and miniature rapid eye movements during sleep. The portable scleral search coil is much more suitable for detecting eye movements than any previously available system because of its precision and simplicity, and because it does not require immobilization of the animal's head. © 2015 European Sleep Research Society.

  4. Prediction of Pig Trade Movements in Different European Production Systems Using Exponential Random Graph Models.

    Science.gov (United States)

    Relun, Anne; Grosbois, Vladimir; Alexandrov, Tsviatko; Sánchez-Vizcaíno, Jose M; Waret-Szkuta, Agnes; Molia, Sophie; Etter, Eric Marcel Charles; Martínez-López, Beatriz

    2017-01-01

    In most European countries, data regarding movements of live animals are routinely collected and can greatly aid predictive epidemic modeling. However, the use of complete movements' dataset to conduct policy-relevant predictions has been so far limited by the massive amount of data that have to be processed (e.g., in intensive commercial systems) or the restricted availability of timely and updated records on animal movements (e.g., in areas where small-scale or extensive production is predominant). The aim of this study was to use exponential random graph models (ERGMs) to reproduce, understand, and predict pig trade networks in different European production systems. Three trade networks were built by aggregating movements of pig batches among premises (farms and trade operators) over 2011 in Bulgaria, Extremadura (Spain), and Côtes-d'Armor (France), where small-scale, extensive, and intensive pig production are predominant, respectively. Three ERGMs were fitted to each network with various demographic and geographic attributes of the nodes as well as six internal network configurations. Several statistical and graphical diagnostic methods were applied to assess the goodness of fit of the models. For all systems, both exogenous (attribute-based) and endogenous (network-based) processes appeared to govern the structure of pig trade network, and neither alone were capable of capturing all aspects of the network structure. Geographic mixing patterns strongly structured pig trade organization in the small-scale production system, whereas belonging to the same company or keeping pigs in the same housing system appeared to be key drivers of pig trade, in intensive and extensive production systems, respectively. Heterogeneous mixing between types of production also explained a part of network structure, whichever production system considered. Limited information is thus needed to capture most of the global structure of pig trade networks. Such findings will be useful

  5. Flying cheap : modelling the passive movement of plants and animals

    NARCIS (Netherlands)

    Treep, H.J.

    2018-01-01

    Movement of organisms is a key process in ecology, as it enables colonization and gene flow. The ongoing worldwide decline of biodiversity and the increasing pressures of climate change and habitat fragmentation, stress the importance of movement ecology research. There is rapid progress in

  6. Exemplar-based Parametric Hidden Markov Models for Recognition and Synthesis of Movements

    DEFF Research Database (Denmark)

    Herzog, Dennis; Krüger, Volker; Grest, Daniel

    2007-01-01

    A common problem in movement recognition is the recognition of movements of a particular type. E.g. pointing movements are of a particular type but differ in terms of the pointing direction. Arm movements with the goal of reaching out and grasping an object are of a particular type but differ...... with the location of the involved object. In this paper, we present an exemplar-based parametric hidden Markov model (PHMM) that is able to recognize and synthesize movements of a particular type. The PHMM is based on exemplar movements that have to be ``demonstrated'' to the system. Recognition and synthesis...... are carried out through locally linear interpolation of the exemplar movements. Experiments are performed with pointing and grasping movements. Synthesis is done based on the object position as parameterization. In case of the recognition, the coordinates of the grasped or pointed at object are recovered. Our...

  7. A computational model for BMP movement in sea urchin embryos.

    Science.gov (United States)

    van Heijster, Peter; Hardway, Heather; Kaper, Tasso J; Bradham, Cynthia A

    2014-12-21

    Bone morphogen proteins (BMPs) are distributed along a dorsal-ventral (DV) gradient in many developing embryos. The spatial distribution of this signaling ligand is critical for correct DV axis specification. In various species, BMP expression is spatially localized, and BMP gradient formation relies on BMP transport, which in turn requires interactions with the extracellular proteins Short gastrulation/Chordin (Chd) and Twisted gastrulation (Tsg). These binding interactions promote BMP movement and concomitantly inhibit BMP signaling. The protease Tolloid (Tld) cleaves Chd, which releases BMP from the complex and permits it to bind the BMP receptor and signal. In sea urchin embryos, BMP is produced in the ventral ectoderm, but signals in the dorsal ectoderm. The transport of BMP from the ventral ectoderm to the dorsal ectoderm in sea urchin embryos is not understood. Therefore, using information from a series of experiments, we adapt the mathematical model of Mizutani et al. (2005) and embed it as the reaction part of a one-dimensional reaction-diffusion model. We use it to study aspects of this transport process in sea urchin embryos. We demonstrate that the receptor-bound BMP concentration exhibits dorsally centered peaks of the same type as those observed experimentally when the ternary transport complex (Chd-Tsg-BMP) forms relatively quickly and BMP receptor binding is relatively slow. Similarly, dorsally centered peaks are created when the diffusivities of BMP, Chd, and Chd-Tsg are relatively low and that of Chd-Tsg-BMP is relatively high, and the model dynamics also suggest that Tld is a principal regulator of the system. At the end of this paper, we briefly compare the observed dynamics in the sea urchin model to a version that applies to the fly embryo, and we find that the same conditions can account for BMP transport in the two types of embryos only if Tld levels are reduced in sea urchin compared to fly. Copyright © 2014 Elsevier Ltd. All rights

  8. Modeling a Small Punch Testing Device

    Directory of Open Access Journals (Sweden)

    S. Habibi

    2014-04-01

    Full Text Available A small punch test of a sample in miniature is implemented in order to estimate the ultimate load of CrMoV ductile steel. The objective of this study is to model the ultimate tensile strength and ultimate load indentation according to the geometrical parameters of the SPT using experimental data. A comparison of the model obtained with the two models (European code of practice and method of Norris and Parker allows the design and dimensioning of an indentation device that meets the practical constraints. Implemented as a Matlab program, allows the investigation of new combinations of test variables.

  9. Showing a model's eye movements in examples does not improve learning of problem-solving tasks

    NARCIS (Netherlands)

    van Marlen, Tim; van Wermeskerken, Margot; Jarodzka, Halszka; van Gog, Tamara

    2016-01-01

    Eye movement modeling examples (EMME) are demonstrations of a computer-based task by a human model (e.g., a teacher), with the model's eye movements superimposed on the task to guide learners' attention. EMME have been shown to enhance learning of perceptual classification tasks; however, it is an

  10. Computational Model-Based Prediction of Human Episodic Memory Performance Based on Eye Movements

    Science.gov (United States)

    Sato, Naoyuki; Yamaguchi, Yoko

    Subjects' episodic memory performance is not simply reflected by eye movements. We use a ‘theta phase coding’ model of the hippocampus to predict subjects' memory performance from their eye movements. Results demonstrate the ability of the model to predict subjects' memory performance. These studies provide a novel approach to computational modeling in the human-machine interface.

  11. Geochemistry, water dynamics and metals: Major, trace elements, Pb and Sr isotope constraints on their origins and movements in a small anthropized catchment over a flood

    International Nuclear Information System (INIS)

    Luck, J.M.; Othman, D.B.

    1997-01-01

    Major, trace elements and Sr-Pb isotope data on the dissolved and particulate phases are reported for water samples taken regularly over the September flood of a Mediterranean river (S France). This river drains runoff from a small, carbonate, karstified watershed with Miocene and Jurassic lithologies, and characterized by agricultural, urban and road network activities. The objective is to combine all the data into a dynamic model for constraining the origin(s) and movements of waters and of their loads. Furthermore, for metals, it becomes then feasible to know their fate and bioavailability downstream

  12. Microcosm Experiments and Modeling of Microbial Movement Under Unsaturated Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Brockman, F.J.; Kapadia, N.; Williams, G.; Rockhold, M.

    2006-04-05

    Colonization of bacteria in porous media has been studied primarily in saturated systems. In this study we examine how microbial colonization in unsaturated porous media is controlled by water content and particle size. This is important for understanding the feasibility and success of bioremediation via nutrient delivery when contaminant degraders are at low densities and when total microbial populations are sparse and spatially discontinuous. The study design used 4 different sand sizes, each at 4 different water contents; experiments were run with and without acetate as the sole carbon source. All experiments were run in duplicate columns and used the motile organism Pseudomonas stutzeri strain KC, a carbon tetrachloride degrader. At a given sand size, bacteria traveled further with increasing volumetric water content. At a given volumetric water content, bacteria generally traveled further with increasing sand size. Water redistribution, solute transport, gas diffusion, and bacterial colonization dynamics were simulated using a numerical finite-difference model. Solute and bacterial transport were modeled using advection-dispersion equations, with reaction rate source/sink terms to account for bacterial growth and substrate utilization, represented using dual Monod-type kinetics. Oxygen transport and diffusion was modeled accounting for equilibrium partitioning between the aqueous and gas phases. The movement of bacteria in the aqueous phase was modeled using a linear impedance model in which the term D{sub m} is a coefficient, as used by Barton and Ford (1995), representing random motility. The unsaturated random motility coefficients we obtained (1.4 x 10{sup -6} to 2.8 x 10{sup -5} cm{sup 2}/sec) are in the same range as those found by others for saturated systems (3.5 x 10{sup -6} to 3.5 x 10{sup -5} cm{sup 2}/sec). The results show that some bacteria can rapidly migrate in well sorted unsaturated sands (and perhaps in relatively high porosity, poorly

  13. Estimating natal dispersal movement rates of female European ducks with multistate modeling

    Science.gov (United States)

    Blums, P.; Nichols, J.D.; Hines, J.E.; Lindberg, M.S.; Mednis, A.

    2003-01-01

    1. We used up to 34 years of capture-recapture data from about 22,100 new releases of day-old female ducklings and multistate modelling to test predictions about the influence of environmental, habitat and management factors on natal dispersal probability of three species of ducks within the Engure Marsh, Latvia. 2. The mean natal dispersal distances were very similar (c . 0?6-0?7 km) for all three species and were on average 2?7 times greater than breeding dispersal distances recorded within the same study system. 3. We were unable to confirm the kinship hypothesis and found no evidence that young first-nesting females nested closer to their relatives (either mother or sister) than to the natal nest. 4. Young female northern shovelers, like adults, moved from small islands to the large island when water level was high and vice versa when water level was low before the construction of elevated small islands. Movement probabilities between the two strata were much higher for young shovelers than adults, suggesting that young birds had not yet developed strong fidelity to the natal site. Movements of young female tufted ducks, unlike those of shovelers, were not dependent on water level fluctuations and reflected substantial flexibility in choice of first nesting sites. 5. Data for young birds supported our earlier conclusion that common pochard nesting habitats in black-headed gull colonies were saturated during the entire study period. Young females, like the two adult age groups, moved into and out of colonies with similar probability. Fidelity probability of female pochards to each stratum increased with age, being the lowest (0?62) for young (DK) females, intermediate (0?78) for yearlings (SY) and the highest (0?84) for adult (ASY) females. 6. Young female tufted ducks, like adults, showed higher probabilities of moving from islands to emergent marshes when water levels were higher both before and after habitat management. The relationship between the spring

  14. Contaminant plume configuration and movement: an experimental model

    Science.gov (United States)

    Alencoao, A.; Reis, A.; Pereira, M. G.; Liberato, M. L. R.; Caramelo, L.; Amraoui, M.; Amorim, V.

    2009-04-01

    The relevance of Science and Technology in our daily routines makes it compulsory to educate citizens who have both scientific literacy and scientific knowledge. These will allow them to be intervening citizens in a constantly changing society. Thus, physical and natural sciences are included in school curricula, both in primary and secondary education, with the fundamental aim of developing in the students the skills, attitudes and knowledge needed for the understanding of the planet Earth and its real problems. On the other hand, teaching in Geosciences is more and more based on practical methodologies which use didactic material, sustaining teachers' pedagogical practices and facilitating students' learning tasks suggested on the syllabus defined for each school level. Themes related to exploring the different components of the Hydrological Cycle and themes related to natural environment protection and preservation, namely water resources and soil contamination by industrial and urban sewage are examples of subject matters included on the Portuguese syllabus. These topics motivated the conception and construction of experimental models for the study of the propagation of pollutants on a porous medium. The experimental models allow inducing a horizontal flux of water though different kinds of permeable substances (e.g. sand, silt), with contamination spots on its surface. These experimental activities facilitate the student to understand the flow path of contaminating substances on the saturated zone and to observe the contaminant plume configuration and movement. The activities are explored in a teaching and learning process perspective where the student builds its own knowledge through real question- problem based learning which relate Science, Technology and Society. These activities have been developed in the framework of project ‘Water in the Environment' (CV/PVI/0854) of the POCTI Program (Programa Operacional "Ciência, Tecnologia, Inovação") financed

  15. Body Movement Music Score – Introduction of a newly developed model for the analysis and description of body qualities, movement and music in music therapy

    Directory of Open Access Journals (Sweden)

    Hanna Agnieszka Skrzypek

    2017-01-01

    Full Text Available Background In music therapy, there is a range of music therapy concepts that, in addition to music, describe and analyse the body and movement. A model that equally examines the body, movement and music has not been developed. The Body Movement Music Score (BMMS is a newly developed and evaluated music therapy model for analysing body qualities, movement, playing style of musical instruments and music and to describe body behaviour and body expression, movement behaviour and movement expression, playing behaviour and musical expression in music therapy treatment. The basis for the development of the Body Movement Music Score was the evaluation of the analytical movement model Emotorics-Emotive Body Movement Mind Paradigm (Emotorics-EBMMP by Yona Shahar Levy for the analysis and description of the emotive-motor behaviour and movement expression of schizophrenic patients in music therapy treatment. Participants and procedure The application of the Body Movement Music Score is presented in a videotaped example from the music therapy treatment of one schizophrenic patient. Results The results of applying the Body Movement Music Score are presented in the form of Body Qualities I Analysis, Body Qualities II Analysis, Movement Analysis, Playing Style Analysis and Music Analysis Profiles. Conclusions The Body Movement Music Score has been developed and evaluated for the music therapy treatment of schizophrenic patients. For the development of the model, a proof of reliability is necessary to verify the reliability and limitations of the model in practice and show that the Body Movement Music Score could be used for both practical and clinical work, for documentation purposes and to impact research in music therapy.

  16. Modeling potential movements of the emerald ash borer: the model framework

    Science.gov (United States)

    Louis R. Iverson; Anantha Prasad; Jonathan Bossenbroek; Davis Sydnor; Mark W. Schwartz

    2010-01-01

    The emerald ash borer (EAB, Agrilus planipennis Fairmaire) is threatening to decimate native ashes (Fraxinus spp.) across North America and, so far, has devastated ash populations across sections of Michigan, Ohio, Indiana, and Ontario. We are attempting to develop a computer model that will predict EAB future movement by adapting...

  17. Using Eye Movements to Model the Sequence of Text-Picture Processing for Multimedia Comprehension

    Science.gov (United States)

    Mason, L.; Scheiter, K.; Tornatora, M. C.

    2017-01-01

    This study used eye movement modeling examples (EMME) to support students' integrative processing of verbal and graphical information during the reading of an illustrated text. EMME consists of a replay of eye movements of a model superimposed onto the materials that are processed for accomplishing the task. Specifically, the study investigated…

  18. Learning to See: Guiding Students' Attention via a Model's Eye Movements Fosters Learning

    Science.gov (United States)

    Jarodzka, Halszka; van Gog, Tamara; Dorr, Michael; Scheiter, Katharina; Gerjets, Peter

    2013-01-01

    This study investigated how to teach perceptual tasks, that is, classifying fish locomotion, through eye movement modeling examples (EMME). EMME consisted of a replay of eye movements of a didactically behaving domain expert (model), which had been recorded while he executed the task, superimposed onto the video stimulus. Seventy-five students…

  19. Modeling of Batter Pile Behavior under Lateral Soil Movement

    Science.gov (United States)

    Chen, C. Y.; Hsu, H. Q.

    2017-06-01

    Pile foundation is frequently used when structures are located on weak sublayers or are at risk from lateral loadings such as earthquakes. The design of pile foundations has recently become crucial to stop slope movement. To understand the behavior of pile foundations subjected to lateral soil movement, the three-dimensional Fast Lagrangian Analysis of Continua (FLAC3D) program was used to perform numerical simulations, which can reduce the cost of field testing. Vertical piles and batter piles were combined into 3 × 3 pile groups, and the response of batter piles to soil movement was analyzed. The outer batter piles led to an increased bending moment in the middle, vertical pile row. Increasing the pile spacing and the presence of battered piles reduced the pile group’s displacement. The batter pile group’s maximum bending moment was smaller than the vertical pile group’s in sand soil, but 5-8 times higher in clay soil.

  20. How-to-Do-It: Tracing Small Mammal Movements with Fluorescent Pigments.

    Science.gov (United States)

    Mullican, Tim R.; Streubel, Donald P.

    1989-01-01

    Discussed is an activity designed to teach small mammal ecology and the scientific method using fluorescent dyes and pigments. Procedures for analyzing home ranges and social organizations are described. A list of 16 references is included. (CW)

  1. Toward the quantification of a conceptual framework for movement ecology using circular statistical modeling.

    Science.gov (United States)

    Shimatani, Ichiro Ken; Yoda, Ken; Katsumata, Nobuhiro; Sato, Katsufumi

    2012-01-01

    To analyze an animal's movement trajectory, a basic model is required that satisfies the following conditions: the model must have an ecological basis and the parameters used in the model must have ecological interpretations, a broad range of movement patterns can be explained by that model, and equations and probability distributions in the model should be mathematically tractable. Random walk models used in previous studies do not necessarily satisfy these requirements, partly because movement trajectories are often more oriented or tortuous than expected from the models. By improving the modeling for turning angles, this study aims to propose a basic movement model. On the basis of the recently developed circular auto-regressive model, we introduced a new movement model and extended its applicability to capture the asymmetric effects of external factors such as wind. The model was applied to GPS trajectories of a seabird (Calonectris leucomelas) to demonstrate its applicability to various movement patterns and to explain how the model parameters are ecologically interpreted under a general conceptual framework for movement ecology. Although it is based on a simple extension of a generalized linear model to circular variables, the proposed model enables us to evaluate the effects of external factors on movement separately from the animal's internal state. For example, maximum likelihood estimates and model selection suggested that in one homing flight section, the seabird intended to fly toward the island, but misjudged its navigation and was driven off-course by strong winds, while in the subsequent flight section, the seabird reset the focal direction, navigated the flight under strong wind conditions, and succeeded in approaching the island.

  2. Movements and behaviour by juvenile Atlantic salmon in relation to ice conditions in small rivers in Canada and Norway

    Energy Technology Data Exchange (ETDEWEB)

    Linnansaari, T.; Cunjak, R.A. [New Brunswick Univ., Saint John, NB (Canada). Canadian Rivers Inst., Dept. of Biology; Stickler, M.; Alfredsen, K. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Dept. of Hydraulic and Environmental Engineering; Arnekleiv, J.V. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Museum of Natural History and Archeology; Fjeldstad, H.P.; Halleraker, J.H.; Harby, A. [Sintef Energy Research, Trondheim (Norway)

    2005-07-01

    Ice dominates aquatic habitats in temperate and polar regions for a large part of the year. Different ice formations below and above the water surface occur depending on the river characteristics and the local climate. Aquatic microhabitats are influenced by rapidly changing ice conditions which redistribute the flow pattern and cause water velocities and depths to change. In shallow streams significant variation occurs in the physical habitat even within a 24-h cycle in early winter. Increased movements of fish have been observed in response to declining water temperatures. In particular, salmonids may have problems acclimatizing to these rapidly changing conditions during early winter. Passive Integrated Transponder (PIT) technology was used in this study to track the individual movement and behaviour of 144 tagged Atlantic salmon parr during two winters from 2003-2005. This method has proven to be efficient even during the most challenging winter conditions. It allows for accurate spatial positioning of the fish across different mesohabitat classes in shallow headwater streams. The movements of PIT-tagged juvenile Atlantic salmon were followed under various ice conditions in 3 small streams: 1) Catamaran Brook in northern New Brunswick, 2) Dalaa River in Norway, and 3) Sokna River in Norway. The physical characteristics of the study sites were presented. All of the study sites were affected by variable ice formations between October and April and most of the surface area was ice covered by January. The water temperature regime during the study period was also presented. Juvenile Atlantic salmon was the dominant fish species in all of the study sites, with small populations of trout. The primary objective was to identify any causal mechanisms between ice formation and fish movement. Their behaviour and site fidelity was also investigated. The study revealed that fish often chose positions under ice cover if the ice was near to the initial territory of parr, but

  3. Tidal Movement of Nioghalvfjerdsfjorden Glacier, Northeast Greenland: Observations and Modelling

    DEFF Research Database (Denmark)

    Reeh, Niels; Mayer, C.; Olesen, O. B.

    2000-01-01

    , 1997 and 1998. As part of this work, tidal-movement observations were carried out by simultaneous differential global positioning system (GPS) measurements at several locations distributed on the glacier surface. The GPS observations were performed continuously over several tidal cycles. At the same...

  4. Coordination Mechanisms in Fast Human Movement. Experimental and Modelling Studies.

    Science.gov (United States)

    1984-07-15

    INTRODUCTION Whether the performance task involves the total body as in gymnastics , or only a part of the body as in playing a piano, skilled performance is...Human stretch reflexes (SRs) are often too weak and ineffectual to provide adequate postural regulation or rhythmic movement boosting (e.g. in ankle

  5. Modelling active antennal movements of the American cockroach

    DEFF Research Database (Denmark)

    Pequeno-Zurro, Alejandro; Nitschke, Jahn; Szyszka, Paul

    2017-01-01

    and the spatial properties of encountered odorant concentrations. Video recordings reveal that the animal’s antennae exhibit systematic movements in the presence of behaviourally relevant odorants. We hypothesise a dynamic coupling between the left and right antenna modulated by odour stimulation. To test this we...

  6. Small-Animal Models of Zika Virus.

    Science.gov (United States)

    Julander, Justin G; Siddharthan, Venkatraman

    2017-12-16

    Zika virus (ZIKV) infection can result in serious consequences, including severe congenital manifestations, persistent infection in the testes, and neurologic sequelae. After a pandemic emergence, the virus has spread to much of North and South America and has been introduced to many countries outside of ZIKV-endemic areas as infected travelers return to their home countries. Rodent models have been important in gaining a better understanding of the wide range of disease etiologies associated with ZIKV infection and for the initial phase of developing countermeasures to prevent or treat viral infections. We discuss herein the advantages and disadvantages of small-animal models that have been developed to replicate various aspects of disease associated with ZIKV infection. © The Author(s) 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  7. Business Model Innovation for Small Medium Enterprises

    Directory of Open Access Journals (Sweden)

    Wirania Swasty

    2015-09-01

    Full Text Available Indonesian economy through Small Medium Enterprises (SMEs is expected to absorb labor and contribute to the growth of Gross Domestic Product. However, SMEs lack both managerial and technical skills. This research is about business model innovation for SMEs especially in fashion and garment industry. Study used qualitative approach by mentoring four selected SMEs in Babakan Penghulu Village– Cinambo Sub-District, Eastern Bandung. The tools used to analyze them including PEST analysis, Porter’s Five Forces,Resource Based View, Value Chain Analysis and Business Model Canvas. Finding suggests SMEs to have business model innovation derived from value proposition. SMEs should build their own brand awareness. Moreover, as garment and fashion industry, design can be a particularly important part of the Value Proposition. SMEs could communicate its value propositions and inform their service through its official websites and other social media. Since the intangible resources include brand and design, thus SMEs should build brand image and innovate year by year. SMEs must hire designers and launch a series of new products offers under the signature of their own brands. Ideation to strengthen strategies derives from value proposition building block as a starting point. Moreover, Business Model Canvas makes strategy more focused and measurable. Business model innovation is expected to increase overall performance of SMEs.

  8. Study of a bio-mechanical model of the movements and deformations of the pelvic organs and integration in the process of radiotherapy treatment for prostate cancer

    International Nuclear Information System (INIS)

    Azad, M.

    2011-01-01

    One of the goals of optimizing treatment planning of prostate cancer radiation therapy is to maintain the margins added to the clinical target volume (CTV) as small as possible to reduce the volumes of normal tissue irradiated. Several methods have been proposed to define these margins: 1) Methods based on the observation of movements obtained by different imaging systems, 2) The predictive methods of the movement of organs, from a model representing the motions of pelvis organs, a calculation of a margin can be made. We have developed and optimized a finite element bio-mechanical model of the prostate, bladder and rectum. This model describes the movement and deformation of the pelvic organs during the filling of certain organs such as the bladder and rectum. An evaluation of this model to predict the movement of the prostate during the various sessions of radiotherapy is shown using a series of CBCT images (Cone Beam Computerized Tomography). (author)

  9. Analysis and Modelling of Pedestrian Movement Dynamics at Large-scale Events

    NARCIS (Netherlands)

    Duives, D.C.

    2016-01-01

    To what extent can we model the movements of pedestrians who walk across a large-scale event terrain? This dissertation answers this question by analysing the operational movement dynamics of pedestrians in crowds at several large music and sport events in the Netherlands and extracting the key

  10. Small mammal density and movement on the SL-1 disposal area, Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Filipovich, M.A.; Keller, B.L.

    1983-01-01

    This study was initiated to examine the population composition, density and food habits of small mammals on a radioactive waste disposal area. Population parameters of small mammals were studied at 3-month intervals on and adjacent to the SL-1 radioactive waste disposal area (1.4 ha) and a 0.3 ha control area between August 1981 and February 1982 with mark-release methods. Both areas have crested wheatgrass (Agropyron cristatum) stands surrounded by sagebrush steppe. Species composition on the SL-1 and control area was similar to that found on the Subsurface Disposal Area at the Idaho National Engineering Laboratory. Considerable use by small mammals of the perimeter of the crested wheatgrass stands was found on both the SL-1 and control area. Additionally, deer mice (Peromyscus maniculatus) and Ord's kangaroo rats (Dipodomys ordii) that frequent the crested wheatgrass stands of the SL-1 and control area were often captured over 100 m from the crested wheatgrass stands. Thus, future research efforts will focus on examining the intensity of perimeter use and food habits of rodents residing on and adjacent to the SL-1. Results of this study will be used to evaluate ecological conditions that affect small mammal use of radioactive waste disposal areas

  11. Perspectives on a Learning-Model for Innovating Game-Based Movement in Sports and Health

    DEFF Research Database (Denmark)

    Elbæk, Lars; Friis, Jørgen Jakob

    2017-01-01

    an active lifestyle. Such digitally supported movement promote health and underlines a need for students to understand that movement design incorporates many aspects: technology, gamification, motivation and understanding of health. To support this, a movement innovation program was needed at our sports...... science and health education. We therefore ask: Which learning approach and educational factors does a learning model need to provide, in order to establish the best foundation for learning innovation and the design of game-based movement solutions within sport and health education? This paper suggests...... a model that covers three approaches; design ‘for’, ‘with’ and ‘of’ movement. From an innovation perspective, it is essential to sense needs and identify future opportunities. This includes understanding technologies and the lives of potential users. Being able to transform core knowledge and insights...

  12. Computational Aerodynamic Modeling of Small Quadcopter Vehicles

    Science.gov (United States)

    Yoon, Seokkwan; Ventura Diaz, Patricia; Boyd, D. Douglas; Chan, William M.; Theodore, Colin R.

    2017-01-01

    High-fidelity computational simulations have been performed which focus on rotor-fuselage and rotor-rotor aerodynamic interactions of small quad-rotor vehicle systems. The three-dimensional unsteady Navier-Stokes equations are solved on overset grids using high-order accurate schemes, dual-time stepping, low Mach number preconditioning, and hybrid turbulence modeling. Computational results for isolated rotors are shown to compare well with available experimental data. Computational results in hover reveal the differences between a conventional configuration where the rotors are mounted above the fuselage and an unconventional configuration where the rotors are mounted below the fuselage. Complex flow physics in forward flight is investigated. The goal of this work is to demonstrate that understanding of interactional aerodynamics can be an important factor in design decisions regarding rotor and fuselage placement for next-generation multi-rotor drones.

  13. An ocular biomechanic model for dynamic simulation of different eye movements.

    Science.gov (United States)

    Iskander, J; Hossny, M; Nahavandi, S; Del Porto, L

    2018-04-11

    Simulating and analysing eye movement is useful for assessing visual system contribution to discomfort with respect to body movements, especially in virtual environments where simulation sickness might occur. It can also be used in the design of eye prosthesis or humanoid robot eye. In this paper, we present two biomechanic ocular models that are easily integrated into the available musculoskeletal models. The model was previously used to simulate eye-head coordination. The models are used to simulate and analyse eye movements. The proposed models are based on physiological and kinematic properties of the human eye. They incorporate an eye-globe, orbital suspension tissues and six muscles with their connective tissues (pulleys). Pulleys were incorporated in rectus and inferior oblique muscles. The two proposed models are the passive pulleys and the active pulleys models. Dynamic simulations of different eye movements, including fixation, saccade and smooth pursuit, are performed to validate both models. The resultant force-length curves of the models were similar to the experimental data. The simulation results show that the proposed models are suitable to generate eye movement simulations with results comparable to other musculoskeletal models. The maximum kinematic root mean square error (RMSE) is 5.68° and 4.35° for the passive and active pulley models, respectively. The analysis of the muscle forces showed realistic muscle activation with increased muscle synergy in the active pulley model. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Mapping behavioral landscapes for animal movement: a finite mixture modeling approach

    Science.gov (United States)

    Tracey, Jeff A.; Zhu, Jun; Boydston, Erin E.; Lyren, Lisa M.; Fisher, Robert N.; Crooks, Kevin R.

    2013-01-01

    Because of its role in many ecological processes, movement of animals in response to landscape features is an important subject in ecology and conservation biology. In this paper, we develop models of animal movement in relation to objects or fields in a landscape. We take a finite mixture modeling approach in which the component densities are conceptually related to different choices for movement in response to a landscape feature, and the mixing proportions are related to the probability of selecting each response as a function of one or more covariates. We combine particle swarm optimization and an Expectation-Maximization (EM) algorithm to obtain maximum likelihood estimates of the model parameters. We use this approach to analyze data for movement of three bobcats in relation to urban areas in southern California, USA. A behavioral interpretation of the models revealed similarities and differences in bobcat movement response to urbanization. All three bobcats avoided urbanization by moving either parallel to urban boundaries or toward less urban areas as the proportion of urban land cover in the surrounding area increased. However, one bobcat, a male with a dispersal-like large-scale movement pattern, avoided urbanization at lower densities and responded strictly by moving parallel to the urban edge. The other two bobcats, which were both residents and occupied similar geographic areas, avoided urban areas using a combination of movements parallel to the urban edge and movement toward areas of less urbanization. However, the resident female appeared to exhibit greater repulsion at lower levels of urbanization than the resident male, consistent with empirical observations of bobcats in southern California. Using the parameterized finite mixture models, we mapped behavioral states to geographic space, creating a representation of a behavioral landscape. This approach can provide guidance for conservation planning based on analysis of animal movement data using

  15. Modeling of tanker movement at the oil terminal in the high seas at crosshair management

    Directory of Open Access Journals (Sweden)

    Petrov S.O.

    2015-03-01

    Full Text Available The process of modeling of tanker movement during cargo operations at the oil terminal in the high seas has been considered. An innovative method of crosshair management has been used

  16. Modeling of movement-induced and flow-induced fluid forces in fast switching valves

    DEFF Research Database (Denmark)

    Roemer, Daniel Beck; Johansen, Per; Schmidt, Lasse

    2015-01-01

    Fast switching fluid power valves set strict requirements on performance, size and energy efficiency and simulation models are therefore needed to obtain good designs of such components. The valve moving member is subject to fluid forces depending on the valve flow rate and movement of the valve...... member itself. These fluid forces may be accurately simulated using Computational Fluid Dynamics (CFD) analysis, but such models suffer from being computationally expensive and is not suited for optimization routines. In this paper, a computationally inexpensive method for modeling the fluid forces...... is proposed, which includes both the flow-induced fluid forces and the movement-induced fluid forces resulting from movement of the valve moving member. The movement-induced fluid force model is based on a known solution to the linearized Navier-Stokes equations. A method for accurately simulating the flow...

  17. NEUROMUSCULAR ELECTRICAL STIMULATION OF THE HINDLIMB MUSCLES FOR MOVEMENT THERAPY IN A RODENT MODEL

    OpenAIRE

    Ichihara, Kazuhiko; Venkatasubramanian, Ganapriya; Abbas, James J.; Jung, Ranu

    2008-01-01

    Neuromuscular electrical stimulation (NMES) can provide functional movements in people after central nervous system injury. The neuroplastic effects of long-term NMES induced repetitive limb movement are not well understood. A rodent model of neurotrauma in which NMES can be implemented may be effective for such investigations. We present a rodent model for NMES of the flexor and extensor muscles of the hip, knee, and ankle hindlimb muscles. Custom fabricated intramuscular stimulating electro...

  18. Advanced Small Modular Reactor Economics Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Thomas J [ORNL

    2014-10-01

    The US Department of Energy Office of Nuclear Energy’s Advanced Small Modular Reactor (SMR) research and development activities focus on four key areas: Developing assessment methods for evaluating advanced SMR technologies and characteristics; and Developing and testing of materials, fuels and fabrication techniques; and Resolving key regulatory issues identified by US Nuclear Regulatory Commission and industry; and Developing advanced instrumentation and controls and human-machine interfaces. This report focuses on development of assessment methods to evaluate advanced SMR technologies and characteristics. Specifically, this report describes the expansion and application of the economic modeling effort at Oak Ridge National Laboratory. Analysis of the current modeling methods shows that one of the primary concerns for the modeling effort is the handling of uncertainty in cost estimates. Monte Carlo–based methods are commonly used to handle uncertainty, especially when implemented by a stand-alone script within a program such as Python or MATLAB. However, a script-based model requires each potential user to have access to a compiler and an executable capable of handling the script. Making the model accessible to multiple independent analysts is best accomplished by implementing the model in a common computing tool such as Microsoft Excel. Excel is readily available and accessible to most system analysts, but it is not designed for straightforward implementation of a Monte Carlo–based method. Using a Monte Carlo algorithm requires in-spreadsheet scripting and statistical analyses or the use of add-ons such as Crystal Ball. An alternative method uses propagation of error calculations in the existing Excel-based system to estimate system cost uncertainty. This method has the advantage of using Microsoft Excel as is, but it requires the use of simplifying assumptions. These assumptions do not necessarily bring into question the analytical results. In fact, the

  19. A Hidden Markov Movement Model for rapidly identifying behavioral states from animal tracks

    DEFF Research Database (Denmark)

    Whoriskey, Kim; Auger-Méthé, Marie; Albertsen, Christoffer Moesgaard

    2017-01-01

    1. Electronic telemetry is frequently used to document animal movement through time. Methods that can identify underlying behaviors driving specific movement patterns can help us understand how and why animals use available space, thereby aiding conservation and management efforts. For aquatic...... animal tracking data with significant measurement error, a Bayesian state-space model called the first-Difference Correlated Random Walk with Switching (DCRWS) has often been used for this purpose. However, for aquatic animals, highly accurate tracking data of animal movement are now becoming more common....... 2. We developed a new Hidden Markov Model (HMM) for identifying behavioral states from animal tracks with negligible error, which we called the Hidden Markov Movement Model (HMMM). We implemented as the basis for the HMMM the process equation of the DCRWS, but we used the method of maximum...

  20. Jaguars on the move: modeling movement to mitigate fragmentation from road expansion in the Mayan Forests

    DEFF Research Database (Denmark)

    Colchero, Fernando; Conde, Dalia Amor; Manterola, Carlos

    2011-01-01

    Road-induced habitat fragmentation is one of the greatest threats to large carnivores. Wildlife passes have been used to reduce fragmentation by mitigating the effects of roads as barriers to animal movement. However, direct observations of animals crossing roads are extremely rare and thus...... indirect methods are necessary to locate crossings. Yet, current methods fail to incorporate the animals' movement behavior and thus have little predictive power. Based on the principles of resource selection functions and state-space modeling, we developed a Bayesian movement model applied to radio......-telemetry and GPS data to infer the movement behavior of jaguars Panthera onca as a response to vegetation, roads and human population density in the Mayan Forests of Mexico and Guatemala. We used the results of the model to simulate jaguars moving along a road that bisects the major reserve system in the area...

  1. Model-Based Synthesis of Visual Speech Movements from 3D Video

    Directory of Open Access Journals (Sweden)

    Edge JamesD

    2009-01-01

    Full Text Available We describe a method for the synthesis of visual speech movements using a hybrid unit selection/model-based approach. Speech lip movements are captured using a 3D stereo face capture system and split up into phonetic units. A dynamic parameterisation of this data is constructed which maintains the relationship between lip shapes and velocities; within this parameterisation a model of how lips move is built and is used in the animation of visual speech movements from speech audio input. The mapping from audio parameters to lip movements is disambiguated by selecting only the most similar stored phonetic units to the target utterance during synthesis. By combining properties of model-based synthesis (e.g., HMMs, neural nets with unit selection we improve the quality of our speech synthesis.

  2. Use of colloid filtration theory in modeling movement of bacteria through a contaminated sandy aquifer

    Science.gov (United States)

    Harvey, R.W.; Garabedian, S.P.

    1991-01-01

    ??? A filtration model commonly used to describe removal of colloids during packed-bed filtration in water treatment applications was modified for describing downgradient transport of bacteria in sandy, aquifer sediments. The modified model was applied to the results of a small-scale (7 m), natural-gradient tracer test and to observations of an indigenous bacterial population moving downgradient within a plume of organically contaminated groundwater in Cape Cod, MA. The model reasonably accounted for concentration histories of labeled bacteria appearing at samplers downgradient from the injection well in the tracer experiment and for the observed 0.25-??m increase in average cell length for an unlabeled, indigenous bacterial population, 0.6 km downgradient from the source of the plume. Several uncertainties were apparent in applying filtration theory to problems involving transport of bacteria in groundwater. However, adsorption (attachment) appeared to be a major control of the extent of bacterial movement downgradient, which could be described, in part, by filtration theory. Estimates of the collision efficiency factor, which represents the physicochemical factors that determine adsorption of the bacteria onto the grain surfaces, ranged from 5.4 ?? 10-3 to 9.7 ?? 10-3.

  3. Modeling and forecasting monthly movement of annual average solar insolation based on the least-squares Fourier-model

    International Nuclear Information System (INIS)

    Yang, Zong-Chang

    2014-01-01

    Highlights: • Introduce a finite Fourier-series model for evaluating monthly movement of annual average solar insolation. • Present a forecast method for predicting its movement based on the extended Fourier-series model in the least-squares. • Shown its movement is well described by a low numbers of harmonics with approximately 6-term Fourier series. • Predict its movement most fitting with less than 6-term Fourier series. - Abstract: Solar insolation is one of the most important measurement parameters in many fields. Modeling and forecasting monthly movement of annual average solar insolation is of increasingly importance in areas of engineering, science and economics. In this study, Fourier-analysis employing finite Fourier-series is proposed for evaluating monthly movement of annual average solar insolation and extended in the least-squares for forecasting. The conventional Fourier analysis, which is the most common analysis method in the frequency domain, cannot be directly applied for prediction. Incorporated with the least-square method, the introduced Fourier-series model is extended to predict its movement. The extended Fourier-series forecasting model obtains its optimums Fourier coefficients in the least-square sense based on its previous monthly movements. The proposed method is applied to experiments and yields satisfying results in the different cities (states). It is indicated that monthly movement of annual average solar insolation is well described by a low numbers of harmonics with approximately 6-term Fourier series. The extended Fourier forecasting model predicts the monthly movement of annual average solar insolation most fitting with less than 6-term Fourier series

  4. Hillslope sediment and soil carbon transport: can we model their movement?

    Science.gov (United States)

    Hancock, Greg; Kunkel, Veikko; Dever, Chris; Braggins, Matthew; Willgoose, Garry

    2016-04-01

    Quantifying and predicting the movement of hillslope sediment and soil organic carbon (SOC) is of huge scientific, agronomic and economic benefit. In particular, the movement and fate of SOC has attracted considerable recent attention. However, the reliable modelling and prediction of sediment and SOC movement has proved elusive. Here we examine the movement of sediment and SOC along a grazing hillslope in south-eastern Australia. The slope is linear, uniformly managed and has consistent vegetation (grassland). We quantify sediment and SOC transport using the environmental tracer 137-Ceasium. However, here we collect field samples using the conventional soil cores but also shallow samples to quantify the dynamics of the near surface. We also model the movement of sediment and SOC using a numerically based soil erosion and landscape evolution model. Our results show that the hillslope is erosional which is supported by field observation. However, there was no relationship between SOC and 137-Caesium suggesting that SOC and their movement and fate are not related. Significant relationships were observed between soil texture and SOC for the near surface but not for the deeper cores suggesting any movement and fate of SOC is more controlled by soil particle size at the near surface. The SIBERIA sediment transport model was calibrated and run for the site. Comparing the field derived erosion and SOC data with model prediction found no significant relationship. However, the numerical model was able to predict the cyclic pattern of 137-Ceasium and SOC as well as overall trends. Our findings demonstrate that the movement and fate of sediment and SOC is complex.

  5. Computational movement analysis

    CERN Document Server

    Laube, Patrick

    2014-01-01

    This SpringerBrief discusses the characteristics of spatiotemporal movement data, including uncertainty and scale. It investigates three core aspects of Computational Movement Analysis: Conceptual modeling of movement and movement spaces, spatiotemporal analysis methods aiming at a better understanding of movement processes (with a focus on data mining for movement patterns), and using decentralized spatial computing methods in movement analysis. The author presents Computational Movement Analysis as an interdisciplinary umbrella for analyzing movement processes with methods from a range of fi

  6. Model for movement of molten limiter material during the ISX-B beryllium limiter experiment

    International Nuclear Information System (INIS)

    Langley, R.A.; England, A.C.; Edmonds, P.H.; Hogan, J.T.; Neilson, G.H.

    1986-01-01

    A model is proposed for the movement and erosion of limiter material during the Beryllium Limiter Experiment performed on the ISX-B Tokamak. This model is consistent with observed experimental results and plasma operational characteristics. Conclusions drawn from the model can provide an understanding of erosion mechanisms, thereby contributing to the development of future design criteria. (author)

  7. Movement as a critical concept in model generation to attain wholeness

    Directory of Open Access Journals (Sweden)

    Charlene Downing

    2017-10-01

    Full Text Available Movement is an integral aspect of daily living. Movement allows the human being to express, find meaning and reflect a part or the whole of the unfolding of the stories of their lives. The essence of the dialogue is the movement towards caring and healing between the professional nurse and the individual.The purpose of this research is to develop, describe, evaluate and provide guidelines for the operationalisation of a model as a framework of reference for nursing to facilitate the individual faced with mental health challenges as an integral part of wholeness. A model was generated to facilitate the engagement of self through movement, which contributes to and manifests in a mindful way of living to promote mental health as an integral part of wholeness. The findings of the study are applicable to the world of nursing practice, nursing education and research.

  8. Hybrid Modelling of Individual Movement and Collective Behaviour

    KAUST Repository

    Franz, Benjamin

    2013-01-01

    Mathematical models of dispersal in biological systems are often written in terms of partial differential equations (PDEs) which describe the time evolution of population-level variables (concentrations, densities). A more detailed modelling approach is given by individual-based (agent-based) models which describe the behaviour of each organism. In recent years, an intermediate modelling methodology - hybrid modelling - has been applied to a number of biological systems. These hybrid models couple an individual-based description of cells/animals with a PDE-model of their environment. In this chapter, we overview hybrid models in the literature with the focus on the mathematical challenges of this modelling approach. The detailed analysis is presented using the example of chemotaxis, where cells move according to extracellular chemicals that can be altered by the cells themselves. In this case, individual-based models of cells are coupled with PDEs for extracellular chemical signals. Travelling waves in these hybrid models are investigated. In particular, we show that in contrary to the PDEs, hybrid chemotaxis models only develop a transient travelling wave. © 2013 Springer-Verlag Berlin Heidelberg.

  9. Modelling human musculoskeletal functional movements using ultrasound imaging

    Directory of Open Access Journals (Sweden)

    Stenlund Hans

    2010-05-01

    Full Text Available Abstract Background A widespread and fundamental assumption in the health sciences is that muscle functions are related to a wide variety of conditions, for example pain, ischemic and neurological disorder, exercise and injury. It is therefore highly desirable to study musculoskeletal contributions in clinical applications such as the treatment of muscle injuries, post-surgery evaluations, monitoring of progressive degeneration in neuromuscular disorders, and so on. The spatial image resolution in ultrasound systems has improved tremendously in the last few years and nowadays provides detailed information about tissue characteristics. It is now possible to study skeletal muscles in real-time during activity. Methods The ultrasound images are transformed to be congruent and are effectively compressed and stacked in order to be analysed with multivariate techniques. The method is applied to a relevant clinical orthopaedic research field, namely to describe the dynamics in the Achilles tendon and the calf during real-time movements. Results This study introduces a novel method to medical applications that can be used to examine ultrasound image sequences and to detect, visualise and quantify skeletal muscle dynamics and functions. Conclusions This new objective method is a powerful tool to use when visualising tissue activity and dynamics of musculoskeletal ultrasound registrations.

  10. A NEW CONCEPT OF MODELING NEEDS OF THE POPULATION IN THE LABOR MOVEMENT BY PUBLIC TRANSPORT

    Directory of Open Access Journals (Sweden)

    P. F. Ghorbachov

    2015-05-01

    Full Text Available In the paper, with the purpose of accounting a casual character of distribution of capacities of transport areas on labor movements in a matrix of correspondences, the interval concept of modeling the population needs in movements has been suggested when for transport calculations one uses not one variant of a matrix but borders of an interval of its possible values at the set area capacities.

  11. The Earth's Shape and Movements: Teachers' Perception of the Relations Between Daily Observation and Scientific Models

    Science.gov (United States)

    Ferreira, Flávia Polati; Leite, Cristina

    2015-07-01

    The Earth’s shape and movements are some of the most common issues in official documents and research studies of astronomy education. Many didactic proposals suggest these issues within observational astronomy. Therefore, we present in this paper some of the main results of a research study of the teachers’ perception of the relations between the knowledge from daily observation and scientific models currently accepted about the “earth’s shape and movements”. Data were obtained in application of the didactic proposal during a teacher training course for teachers from São Paulo, have been constructed with the dynamics “Three Pedagogical Moments” and guided by some of the central ideas of the educator Paulo Freire. The results indicate that a small proportion of teachers seem to understand some of the relations of “apparent contradictions” and “limitations” with the concepts of spatiality, and many of them argued based only on vague phrases or "buzzwords", unconnected to the problem explored. The difficulties of teachers to relate elements of daily observation with scientific models seem to indicate a necessity to approach some these aspects with the astronomical knowledge in the teacher training courses.

  12. Impact of respiratory movement on the computed tomographic images of small lung tumors in three-dimensional (3D) radiotherapy

    International Nuclear Information System (INIS)

    Shimizu, Shinichi; Shirato, Hiroki; Kagei, Kenji; Nishioka, Takeshi; Bo Xo; Dosaka-Akita, Hirotoshi; Hashimoto, Seiko; Aoyama, Hidefumi; Tsuchiya, Kazuhiko; Miyasaka, Kazuo

    2000-01-01

    Purpose: Three-dimensional (3D) treatment planning has often been performed while patients breathe freely, under the assumption that the computed tomography (CT) images represent the average position of the tumor. We investigated the impact of respiratory movement on the free-breathing CT images of small lung tumors using sequential CT scanning at the same table position. Methods: Using a preparatory free-breathing CT scan, the patient's couch was fixed at the position where each tumor showed its maximum diameter on image. For 16 tumors, over 20 sequential CT images were taken every 2 s, with a 1-s acquisition time occurring during free breathing. For each tumor, the distance between the surface of the CT table and the posterior border of the tumor was measured to determine whether the edge of the tumor was sufficiently included in the planning target volume (PTV) during normal breathing. Results: In the sequential CT scanning, the tumor itself was not visible in the examination slice in 21% (75/357) of cases. There were statistically significant differences between lower lobe tumors (39.4%, 71/180) and upper lobe tumors (0%, 0/89) (p < 0.01) and between lower lobe tumors and middle lobe tumor (8.9%, 4/45) (p < 0.01) in the incidence of the disappearance of the tumor from the image. The mean difference between the maximum and minimum distances between the surface of the CT table and the posterior border of the tumor was 6.4 mm (range 2.1-24.4). Conclusion: Three-dimensional treatment planning for lung carcinoma would significantly underdose many lesions, especially those in the lower lobe. The excess 'safety margin' might call into question any additional benefit of 3D treatment. More work is required to determine how to control respiratory movement

  13. Generalized Pareto for Pattern-Oriented Random Walk Modelling of Organisms' Movements.

    Science.gov (United States)

    Bertrand, Sophie; Joo, Rocío; Fablet, Ronan

    2015-01-01

    How organisms move and disperse is crucial to understand how population dynamics relates to the spatial heterogeneity of the environment. Random walk (RW) models are typical tools to describe movement patterns. Whether Lévy or alternative RW better describes forager movements is keenly debated. We get around this issue using the Generalized Pareto Distribution (GPD). GPD includes as specific cases Normal, exponential and power law distributions, which underlie Brownian, Poisson-like and Lévy walks respectively. Whereas previous studies typically confronted a limited set of candidate models, GPD lets the most likely RW model emerge from the data. We illustrate the wide applicability of the method using GPS-tracked seabird foraging movements and fishing vessel movements tracked by Vessel Monitoring System (VMS), both collected in the Peruvian pelagic ecosystem. The two parameters from the fitted GPD, a scale and a shape parameter, provide a synoptic characterization of the observed movement in terms of characteristic scale and diffusive property. They reveal and quantify the variability, among species and individuals, of the spatial strategies selected by predators foraging on a common prey field. The GPD parameters constitute relevant metrics for (1) providing a synthetic and pattern-oriented description of movement, (2) using top predators as ecosystem indicators and (3) studying the variability of spatial behaviour among species or among individuals with different personalities.

  14. Generalized Pareto for Pattern-Oriented Random Walk Modelling of Organisms’ Movements

    Science.gov (United States)

    Bertrand, Sophie; Joo, Rocío; Fablet, Ronan

    2015-01-01

    How organisms move and disperse is crucial to understand how population dynamics relates to the spatial heterogeneity of the environment. Random walk (RW) models are typical tools to describe movement patterns. Whether Lévy or alternative RW better describes forager movements is keenly debated. We get around this issue using the Generalized Pareto Distribution (GPD). GPD includes as specific cases Normal, exponential and power law distributions, which underlie Brownian, Poisson-like and Lévy walks respectively. Whereas previous studies typically confronted a limited set of candidate models, GPD lets the most likely RW model emerge from the data. We illustrate the wide applicability of the method using GPS-tracked seabird foraging movements and fishing vessel movements tracked by Vessel Monitoring System (VMS), both collected in the Peruvian pelagic ecosystem. The two parameters from the fitted GPD, a scale and a shape parameter, provide a synoptic characterization of the observed movement in terms of characteristic scale and diffusive property. They reveal and quantify the variability, among species and individuals, of the spatial strategies selected by predators foraging on a common prey field. The GPD parameters constitute relevant metrics for (1) providing a synthetic and pattern–oriented description of movement, (2) using top predators as ecosystem indicators and (3) studying the variability of spatial behaviour among species or among individuals with different personalities. PMID:26172045

  15. Computational Modelling and Movement Analysis of Hip Joint with Muscles

    Science.gov (United States)

    Siswanto, W. A.; Yoon, C. C.; Salleh, S. Md.; Ngali, M. Z.; Yusup, Eliza M.

    2017-01-01

    In this study, the model of hip joint and the main muscles are modelled by finite elements. The parts included in the model are hip joint, hemi pelvis, gluteus maximus, quadratus femoris and gamellus inferior. The materials that used in these model are isotropic elastic, Mooney Rivlin and Neo-hookean. The hip resultant force of the normal gait and stair climbing are applied on the model of hip joint. The responses of displacement, stress and strain of the muscles are then recorded. FEBio non-linear solver for biomechanics is employed to conduct the simulation of the model of hip joint with muscles. The contact interfaces that used in this model are sliding contact and tied contact. From the analysis results, the gluteus maximus has the maximum displacement, stress and strain in the stair climbing. Quadratus femoris and gamellus inferior has the maximum displacement and strain in the normal gait however the maximum stress in the stair climbing. Besides that, the computational model of hip joint with muscles is produced for research and investigation platform. The model can be used as a visualization platform of hip joint.

  16. A large 3D physical model: a tool to investigate the consequences of ground movements on the surface structures

    Directory of Open Access Journals (Sweden)

    Hor B.

    2010-06-01

    Full Text Available Soil subsidence of various extend and amplitude can result from the failure of underground cavities, whether natural (for example caused by the dissolution of rocks by underground water flow or man-made (such as mines. The impact of the ground movements on existing structures (houses, buildings, bridges, etc… is generally dramatic. A large small-scale physical model is developed in order to improve our understanding of the behaviour of the building subjected to ground subsidence or the collapse of cavities. We focus on the soil-structure interaction and on the mitigation techniques allowing reducing the vulnerability of the buildings (structures.

  17. Modeling the Movement of Beach Alluvia in the Alongshore Direction

    Directory of Open Access Journals (Sweden)

    Elena V. Bondareva

    2014-06-01

    Full Text Available The authors have worked out a design model for the dynamics of a mixed-composition beach in the vicinity of transverse structures. The model uses a modified formula for calculating alluvia, which is based on modified energy dependencies. The authors provide an algorithm for performing these calculations.

  18. The punctum fixum-punctum mobile model: a neuromuscular principle for efficient movement generation?

    Directory of Open Access Journals (Sweden)

    Christoph von Laßberg

    Full Text Available According to the "punctum fixum-punctum mobile model" that was introduced in prior studies, for generation of the most effective intentional acceleration of a body part the intersegmental neuromuscular onset succession has to spread successively from the rotation axis (punctum fixum toward the body part that shall be accelerated (punctum mobile. The aim of the present study was to investigate whether this principle is, indeed, fundamental for any kind of efficient rotational accelerations in general, independent of the kind of movements, type of rotational axis, the current body position, or movement direction. Neuromuscular onset succession was captured by surface electromyography of relevant muscles of the anterior and posterior muscle chain in 16 high-level gymnasts during intentional accelerating movement phases while performing 18 different gymnastics elements (in various body positions to forward and backward, performed on high bar, parallel bars, rings and trampoline, as well as during non-sport specific pivot movements around the longitudinal axis. The succession patterns to generate the acceleration phases during these movements were described and statistically evaluated based on the onset time difference between the muscles of the corresponding muscle chain. In all the analyzed movement phases, the results clearly support the hypothesized succession pattern from punctum fixum to punctum mobile. This principle was further underlined by the finding that the succession patterns do change their direction running through the body when the rotational axis (punctum fixum has been changed (e.g., high bar or rings [hands] vs. floor or trampoline [feet]. The findings improve our understanding of intersegmental neuromuscular coordination patterns to generate intentional movements most efficiently. This could help to develop more specific methods to facilitate such patterns in particular contexts, thus allowing for shorter motor learning

  19. Applications of flocking algorithms to input modeling for agent movement

    OpenAIRE

    Singham, Dashi; Therkildsen, Meredith; Schruben, Lee

    2011-01-01

    Refereed Conference Paper The article of record as published can be found at http://dx.doi.org/10.1109/WSC.2011.6147953 Simulation flocking has been introduced as a method for generating simulation input from multivariate dependent time series for sensitivity and risk analysis. It can be applied to data for which a parametric model is not readily available or imposes too many restrictions on the possible inputs. This method uses techniques from agent-based modeling to generate ...

  20. Development of a model for evaluating mechanical effects of crustal movements on the disposal system in Japan (Contract research)

    International Nuclear Information System (INIS)

    Nagasawa, Hirokazu; Takeda, Seiji; Kimura, Hideo

    2010-08-01

    In the safety assessment of geological disposal for high level radioactive wastes, it is important to develop the modelling for evaluating mechanical effects of crustal movements on the disposal system in Japan. In this study, the model on crustal movements is represented by accumulating two components of velocity magnitude of the crust to horizontal direction, caused by transient movements associated with fault and/or volcanic activities and ordinary movements with the other continuous factors. We have quantified the ordinary movements with the statistical analysis of data included in the GEONET (GPS Earth Observation Network System) of GSI (Geographical Survey Institute). Okada Model is applied for evaluating the transient movements, which can handle three-dimensional movements of earthquake and volcanic activities theologically and comprehensively. In this report, we provide the specification of the model on crustal movement and analyze the horizontal velocity in Tohoku region using the model. The result indicates that the ordinary movements are classified with magnitude of the longitudinal velocities. The cluster of longitudinal velocities has been distributed along the plate boundary. Because the velocities of the ordinary movements are grater than one of transient movements, the spatial distribution of longitudinal velocities in Tohoku region is similar to that of the ordinary movements. (author)

  1. Numerical modelling of air movement in road tunnels

    International Nuclear Information System (INIS)

    Kashef, A.; Benichou, N.; Lougheed, G. . E-mail; Debs, A.

    2003-01-01

    The objective of the Mechanical Ventilation Systems (MVS) in highway tunnels is to provide tunnel patrons with a reasonable degree of comfort during normal operation and to assist in keeping tunnels safe during emergencies. Temperature, humidity, and air velocity are among the parameters that determine the tunnel environment and indicate the level of MVS performance. To investigate the performance of the current emergency ventilation strategies for an existing tunnel system in the event of a fire, a research project is being conducted at the National Research Council of Canada. The primary objectives of the study are: a) to assess and validate the ability of in-place emergency ventilation strategies to control smoke spread and minimize the impact of smoke on tunnel users; and b) to recommend guidelines for improving ventilation operation to maximize intervention effectiveness. This will allow future development of an intelligent ventilation system based on a pre-established scenario of ventilation activated using automatic fire detection. The research study includes two phases, numerical and experimental phases. The numerical phase will use a CFD model (Solvent) to study smoke ventilation in the tunnel. The experimental phase will be used to calibrate and validate the CFD model and to establish the boundary conditions for the numerical model. Solvent was used to model a ventilation scenario using existing data. The current paper presents the initial efforts to validate the CFD model against onsite flow measurements conducted in the tunnel. The CFD model included aerodynamically significant physical features of the tunnel. (author)

  2. Perspectives on a Learning-Model for Innovating Game-Based Movement in Sports and Health

    DEFF Research Database (Denmark)

    Elbæk, Lars; Friis, Jørgen Jakob

    2017-01-01

    into innovative practice requires abilities best formed in a creative learning environment that also contains a production space, where physical prototypes creates realizations and insights. Learning is optimally done in project-based setups, and close contact with co-learners and mentors plays a central role...... an active lifestyle. Such digitally supported movement promote health and underlines a need for students to understand that movement design incorporates many aspects: technology, gamification, motivation and understanding of health. To support this, a movement innovation program was needed at our sports...... science and health education. We therefore ask: Which learning approach and educational factors does a learning model need to provide, in order to establish the best foundation for learning innovation and the design of game-based movement solutions within sport and health education? This paper suggests...

  3. The Space-Jump Model of the Movement of Tumor Cells and Healthy Cells

    Directory of Open Access Journals (Sweden)

    Meng-Rong Li

    2014-01-01

    Full Text Available We establish the interaction model of two cell populations following the concept of the random-walk, and assume the cell movement is constrained by space limitation primarily. Furthermore, we analyze the model to obtain the behavior of two cell populations as time is closed to initial state and far into the future.

  4. A likelihood-based biostatistical model for analyzing consumer movement in simultaneous choice experiments.

    Science.gov (United States)

    Zeilinger, Adam R; Olson, Dawn M; Andow, David A

    2014-08-01

    Consumer feeding preference among resource choices has critical implications for basic ecological and evolutionary processes, and can be highly relevant to applied problems such as ecological risk assessment and invasion biology. Within consumer choice experiments, also known as feeding preference or cafeteria experiments, measures of relative consumption and measures of consumer movement can provide distinct and complementary insights into the strength, causes, and consequences of preference. Despite the distinct value of inferring preference from measures of consumer movement, rigorous and biologically relevant analytical methods are lacking. We describe a simple, likelihood-based, biostatistical model for analyzing the transient dynamics of consumer movement in a paired-choice experiment. With experimental data consisting of repeated discrete measures of consumer location, the model can be used to estimate constant consumer attraction and leaving rates for two food choices, and differences in choice-specific attraction and leaving rates can be tested using model selection. The model enables calculation of transient and equilibrial probabilities of consumer-resource association, which could be incorporated into larger scale movement models. We explore the effect of experimental design on parameter estimation through stochastic simulation and describe methods to check that data meet model assumptions. Using a dataset of modest sample size, we illustrate the use of the model to draw inferences on consumer preference as well as underlying behavioral mechanisms. Finally, we include a user's guide and computer code scripts in R to facilitate use of the model by other researchers.

  5. Decoding finger movements from ECoG signals using switching linear models

    Directory of Open Access Journals (Sweden)

    Remi eFlamary

    2012-03-01

    Full Text Available One of the most interesting challenges in ECoG-based Brain-Machine Interface is movement prediction. Being able to perform such a prediction paves the way to high-degree precision command for a machine such as a robotic arm or robotic hands. As a witness of the BCI community increasing interest towards such a problem, the fourth BCI Competition provides a dataset which aim is to predict individual finger movements from ECog signals. The difficulty of the problem relies on the fact that there is no simple relation between ECoG signals and finger movements. We propose in this paper, to estimate and decode these finger flexions using switching models controlled by an hidden state. Switching models can integrate prior knowledge about the decoding problem and helps in predicting fine and precise movements. Our model is thus based on a first block which estimates which finger is moving and anotherblock which, knowing which finger is moving, predicts the movements of allother fingers. Numerical results that have been submitted to the Competition show that the model yields high decoding performances when the hidden state is well estimated. This approach achieved the second place in the BCI competition with a correlation measure between real and predictedmovements of 0.42.

  6. Navigational efficiency in a biased and correlated random walk model of individual animal movement.

    Science.gov (United States)

    Bailey, Joseph D; Wallis, Jamie; Codling, Edward A

    2018-01-01

    Understanding how an individual animal is able to navigate through its environment is a key question in movement ecology that can give insight into observed movement patterns and the mechanisms behind them. Efficiency of navigation is important for behavioral processes at a range of different spatio-temporal scales, including foraging and migration. Random walk models provide a standard framework for modeling individual animal movement and navigation. Here we consider a vector-weighted biased and correlated random walk (BCRW) model for directed movement (taxis), where external navigation cues are balanced with forward persistence. We derive a mathematical approximation of the expected navigational efficiency for any BCRW of this form and confirm the model predictions using simulations. We demonstrate how the navigational efficiency is related to the weighting given to forward persistence and external navigation cues, and highlight the counter-intuitive result that for low (but realistic) levels of error on forward persistence, a higher navigational efficiency is achieved by giving more weighting to this indirect navigation cue rather than direct navigational cues. We discuss and interpret the relevance of these results for understanding animal movement and navigation strategies. © 2017 by the Ecological Society of America.

  7. Measurement and Modelling of Blast Movement to Reduce Ore ...

    African Journals Online (AJOL)

    This paper describes the application of the latest measurements and modelling techniques in understanding the blast dynamics and develops site specific solutions to minimise blast induced dilution and ore losses. These solutions are validated at Newmont Ahafo open pit mine through systematic trials and subsequently ...

  8. A parsimonious approach to modeling animal movement data.

    Directory of Open Access Journals (Sweden)

    Yann Tremblay

    Full Text Available Animal tracking is a growing field in ecology and previous work has shown that simple speed filtering of tracking data is not sufficient and that improvement of tracking location estimates are possible. To date, this has required methods that are complicated and often time-consuming (state-space models, resulting in limited application of this technique and the potential for analysis errors due to poor understanding of the fundamental framework behind the approach. We describe and test an alternative and intuitive approach consisting of bootstrapping random walks biased by forward particles. The model uses recorded data accuracy estimates, and can assimilate other sources of data such as sea-surface temperature, bathymetry and/or physical boundaries. We tested our model using ARGOS and geolocation tracks of elephant seals that also carried GPS tags in addition to PTTs, enabling true validation. Among pinnipeds, elephant seals are extreme divers that spend little time at the surface, which considerably impact the quality of both ARGOS and light-based geolocation tracks. Despite such low overall quality tracks, our model provided location estimates within 4.0, 5.5 and 12.0 km of true location 50% of the time, and within 9, 10.5 and 20.0 km 90% of the time, for above, equal or below average elephant seal ARGOS track qualities, respectively. With geolocation data, 50% of errors were less than 104.8 km (<0.94 degrees, and 90% were less than 199.8 km (<1.80 degrees. Larger errors were due to lack of sea-surface temperature gradients. In addition we show that our model is flexible enough to solve the obstacle avoidance problem by assimilating high resolution coastline data. This reduced the number of invalid on-land location by almost an order of magnitude. The method is intuitive, flexible and efficient, promising extensive utilization in future research.

  9. Applications of Flocking Algorithms to Input Modeling for Agent Movement

    Science.gov (United States)

    2011-12-01

    2445 Singham, Therkildsen, and Schruben We apply the following flocking algorithm to this leading boid to generate followers, who will then be mapped...due to the paths crossing. 2447 Singham, Therkildsen, and Schruben Figure 2: Plot of the path of a boid generated by the Group 4 flocking algorithm ...on the possible inputs. This method uses techniques from agent-based modeling to generate a flock of boids that follow the data. In this paper, we

  10. A Brownian Bridge Movement Model to Track Mobile Targets

    Science.gov (United States)

    2016-09-01

    the probability of a pirate attack at various locations and times. In another work, Johnston (1995) applied search theory to estimate the probability...model, developed by the U.S. Naval Research Laboratory, that generates the probability that a pirate will attack at a given time and location in the... Shark onboard the carrier. It would seem that China is making remarkable progress in learning the science and art of carrier aviation and likely will

  11. Movement behaviour within and beyond perceptual ranges in three small mammals: effects of matrix type and body mass.

    Science.gov (United States)

    Prevedello, Jayme Augusto; Forero-Medina, Germán; Vieira, Marcus Vinícius

    2010-11-01

    1. For animal species inhabiting heterogeneous landscapes, the tortuosity of the dispersal path is a key determinant of the success in locating habitat patches. Path tortuosity within and beyond perceptual range must differ, and may be differently affected by intrinsic attributes of individuals and extrinsic environmental factors. Understanding how these factors interact to determine path tortuosity allows more accurate inference of successful movements between habitat patches. 2. We experimentally determined the effects of intrinsic (body mass and species identity) and extrinsic factors (distance to nearest forest fragment and matrix type) on the tortuosity of movements of three forest-dwelling didelphid marsupials, in a fragmented landscape of the Atlantic Forest, Brazil. 3. A total of 202 individuals were captured in forest fragments and released in three unsuitable matrix types (mowed pasture, abandoned pasture and manioc plantation), carrying spool-and-line devices. 4. Twenty-four models were formulated representing a priori hypotheses of major determinants of path tortuosity, grouped in three scenarios (only intrinsic factors, only extrinsic factors and models with combinations of both), and compared using a model selection approach. Models were tested separately for individuals released within the perceptual range of the species, and for individuals released beyond the perceptual range. 5. Matrix type strongly affected path tortuosity, with more obstructed matrix types hampering displacement of animals. Body mass was more important than species identity to determine path tortuosity, with larger animals moving more linearly. Increased distance to the fragment resulted in more tortuous paths, but actually reflects a threshold in perceptual range: linear paths within perceptual range, tortuous paths beyond. 6. The variables tested explained successfully path tortuosity, but only for animals released within the perceptual range. Other factors, such as wind

  12. Implications of movement for species distribution models - Rethinking environmental data tools.

    Science.gov (United States)

    Bruneel, Stijn; Gobeyn, Sacha; Verhelst, Pieterjan; Reubens, Jan; Moens, Tom; Goethals, Peter

    2018-07-01

    Movement is considered an essential process in shaping the distributions of species. Nevertheless, most species distribution models (SDMs) still focus solely on environment-species relationships to predict the occurrence of species. Furthermore, the currently used indirect estimates of movement allow to assess habitat accessibility, but do not provide an accurate description of movement. Better proxies of movement are needed to assess the dispersal potential of individual species and to gain a more practical insight in the interconnectivity of communities. Telemetry techniques are rapidly evolving and highly capable to provide explicit descriptions of movement, but their usefulness for SDMs will mainly depend on the ability of these models to deal with hitherto unconsidered ecological processes. More specifically, the integration of movement is likely to affect the environmental data requirements as the connection between environmental and biological data is crucial to provide reliable results. Mobility implies the occupancy of a continuum of space, hence an adequate representation of both geographical and environmental space is paramount to study mobile species distributions. In this context, environmental models, remote sensing techniques and animal-borne environmental sensors are discussed as potential techniques to obtain suitable environmental data. In order to provide an in-depth review of the aforementioned methods, we have chosen to use the modelling of fish distributions as a case study. The high mobility of fish and the often highly variable nature of the aquatic environment generally complicate model development, making it an adequate subject for research. Furthermore, insight into the distribution of fish is of great interest for fish stock assessments and water management worldwide, underlining its practical relevance. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Musculoskeletal Modeling of a Forward Lunge Movement:Implications for ACL Loading

    DEFF Research Database (Denmark)

    Alkjaer, T; Wieland, MR; Andersen, MS

    2010-01-01

    Context: The forward lunge is widely used among athletes for training and rehabilitation purposes. The forward lunge movement has also been suggested as a model to study functional adaptation to ACL rupture. Previous investigations indicate that the absence of the ACL influences the movement...... pattern of many patients during a forward lunge, while direct measurements of ACL strain show that except for cases close to full extension, quadriceps activity does not seem to influence the ACL strain. The question is whether there are other external forces present in the lunge movement that may cause...... an anterior force on the tibia, requiring the ACL to be intact to stabilize the knee? Objective: To establish a musculoskeletal model of the forward lunge to computationally investigate the force equilibrium in the knee during forward lunge and answer the following questions: 1) Which structures in the knee...

  14. Small-scale anomaly detection in panoramic imaging using neural models of low-level vision

    Science.gov (United States)

    Casey, Matthew C.; Hickman, Duncan L.; Pavlou, Athanasios; Sadler, James R. E.

    2011-06-01

    Our understanding of sensory processing in animals has reached the stage where we can exploit neurobiological principles in commercial systems. In human vision, one brain structure that offers insight into how we might detect anomalies in real-time imaging is the superior colliculus (SC). The SC is a small structure that rapidly orients our eyes to a movement, sound or touch that it detects, even when the stimulus may be on a small-scale; think of a camouflaged movement or the rustle of leaves. This automatic orientation allows us to prioritize the use of our eyes to raise awareness of a potential threat, such as a predator approaching stealthily. In this paper we describe the application of a neural network model of the SC to the detection of anomalies in panoramic imaging. The neural approach consists of a mosaic of topographic maps that are each trained using competitive Hebbian learning to rapidly detect image features of a pre-defined shape and scale. What makes this approach interesting is the ability of the competition between neurons to automatically filter noise, yet with the capability of generalizing the desired shape and scale. We will present the results of this technique applied to the real-time detection of obscured targets in visible-band panoramic CCTV images. Using background subtraction to highlight potential movement, the technique is able to correctly identify targets which span as little as 3 pixels wide while filtering small-scale noise.

  15. Continuum modelling of pedestrian flows - Part 2: Sensitivity analysis featuring crowd movement phenomena

    Science.gov (United States)

    Duives, Dorine C.; Daamen, Winnie; Hoogendoorn, Serge P.

    2016-04-01

    In recent years numerous pedestrian simulation tools have been developed that can support crowd managers and government officials in their tasks. New technologies to monitor pedestrian flows are in dire need of models that allow for rapid state-estimation. Many contemporary pedestrian simulation tools model the movements of pedestrians at a microscopic level, which does not provide an exact solution. Macroscopic models capture the fundamental characteristics of the traffic state at a more aggregate level, and generally have a closed form solution which is necessary for rapid state estimation for traffic management purposes. This contribution presents a next step in the calibration and validation of the macroscopic continuum model detailed in Hoogendoorn et al. (2014). The influence of global and local route choice on the development of crowd movement phenomena, such as dissipation, lane-formation and stripe-formation, is studied. This study shows that most self-organization phenomena and behavioural trends only develop under very specific conditions, and as such can only be simulated using specific parameter sets. Moreover, all crowd movement phenomena can be reproduced by means of the continuum model using one parameter set. This study concludes that the incorporation of local route choice behaviour and the balancing of the aptitude of pedestrians with respect to their own class and other classes are both essential in the correct prediction of crowd movement dynamics.

  16. SMALL BODY SHAPE MODELS V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the Peter Thomas shape models for small solar system bodies, as well as image mosaics constructed from these models. The current version of...

  17. Models To Predict Persistent Scatterers Data Distribution And Their Capacity To Register Movement Along The Slope

    Science.gov (United States)

    Notti, D.; Meisina, C.; Zucca, F.; Colombo, A.

    2012-01-01

    Two models were developed to improve the use of persistent scatterers (PS) techniques in the landslides studies. The first model, called “CR-Index”, allows to forecast the potential PS distribution calculating the effect of topography and of the land use. The second model, called “V slope Coefficient”, has the aim to calculate the percentage of the movement detected along Vlos supposing to have a slide parallel to the maximum slope line.

  18. DETERMINED MODEL FOR COORDINATED REGULATION OF MOTOR TRANSPORT MOVEMENT ON HIGHWAY

    Directory of Open Access Journals (Sweden)

    V. P. Ivanov

    2011-01-01

    Full Text Available The paper examines certain parameters of a determined model and its response to changes in these parameters. The determined model for bidirectional movement has been developed in the paper. The paper contains proposals for an optimization of the developed model which are intended for reduction of motor vehicle delays in front of an in-traffic light stop line along the main highway direction.

  19. Small oilfield integrated production management model

    Directory of Open Access Journals (Sweden)

    Danilović Dušan

    2016-01-01

    Full Text Available In this paper is presented the concept of integrated oil production management model. The model's main objective is to provide more efficient tool for oil production process management in terms of the technological and economical aspects. Integrated oil production management model implies multidisciplinary approach which connects oil reservoir development and production with application of risk analysis. Model's task is to simulate behavior of the whole production system, enabling overcoming the weaknesses of conventional deterministic analysis and significantly enhancing oil production, as well as an investment decision making. In the article is presented shortly the application of integrated oil production management model at the oilfield 'K'. The ultimate goal was techno-economic analysis of managing production process, i.e. determination of production economic limit based on production history data, decline analysis and operating costs.

  20. Model for the prediction of subsurface strata movement due to underground mining

    Science.gov (United States)

    Cheng, Jianwei; Liu, Fangyuan; Li, Siyuan

    2017-12-01

    The problem of ground control stability due to large underground mining operations is often associated with large movements and deformations of strata. It is a complicated problem, and can induce severe safety or environmental hazards either at the surface or in strata. Hence, knowing the subsurface strata movement characteristics, and making any subsidence predictions in advance, are desirable for mining engineers to estimate any damage likely to affect the ground surface or subsurface strata. Based on previous research findings, this paper broadly applies a surface subsidence prediction model based on the influence function method to subsurface strata, in order to predict subsurface stratum movement. A step-wise prediction model is proposed, to investigate the movement of underground strata. The model involves a dynamic iteration calculation process to derive the movements and deformations for each stratum layer; modifications to the influence method function are also made for more precise calculations. The critical subsidence parameters, incorporating stratum mechanical properties and the spatial relationship of interest at the mining level, are thoroughly considered, with the purpose of improving the reliability of input parameters. Such research efforts can be very helpful to mining engineers’ understanding of the moving behavior of all strata over underground excavations, and assist in making any damage mitigation plan. In order to check the reliability of the model, two methods are carried out and cross-validation applied. One is to use a borehole TV monitor recording to identify the progress of subsurface stratum bedding and caving in a coal mine, the other is to conduct physical modelling of the subsidence in underground strata. The results of these two methods are used to compare with theoretical results calculated by the proposed mathematical model. The testing results agree well with each other, and the acceptable accuracy and reliability of the

  1. Gravity monitoring of CO2 movement during sequestration: Model studies

    Energy Technology Data Exchange (ETDEWEB)

    Gasperikova, E.; Hoversten, G.M.

    2008-07-15

    We examine the relative merits of gravity measurements as a monitoring tool for geological CO{sub 2} sequestration in three different modeling scenarios. The first is a combined CO{sub 2} enhanced oil recovery (EOR) and sequestration in a producing oil field, the second is sequestration in a brine formation, and the third is for a coalbed methane formation. EOR/sequestration petroleum reservoirs have relatively thin injection intervals with multiple fluid components (oil, hydrocarbon gas, brine, and CO{sub 2}), whereas brine formations usually have much thicker injection intervals and only two components (brine and CO{sub 2}). Coal formations undergoing methane extraction tend to be thin (3-10 m), but shallow compared to either EOR or brine formations. The injection of CO{sub 2} into the oil reservoir produced a bulk density decrease in the reservoir. The spatial pattern of the change in the vertical component of gravity (G{sub z}) is directly correlated with the net change in reservoir density. Furthermore, time-lapse changes in the borehole G{sub z} clearly identified the vertical section of the reservoir where fluid saturations are changing. The CO{sub 2}-brine front, on the order of 1 km within a 20 m thick brine formation at 1900 m depth, with 30% CO{sub 2} and 70% brine saturations, respectively, produced a -10 Gal surface gravity anomaly. Such anomaly would be detectable in the field. The amount of CO{sub 2} in a coalbed methane test scenario did not produce a large enough surface gravity response; however, we would expect that for an industrial size injection, the surface gravity response would be measurable. Gravity inversions in all three scenarios illustrated that the general position of density changes caused by CO{sub 2} can be recovered, but not the absolute value of the change. Analysis of the spatial resolution and detectability limits shows that gravity measurements could, under certain circumstances, be used as a lower-cost alternative to seismic

  2. Mass movement hazard assessment model in the slope profile

    Science.gov (United States)

    Colangelo, A. C.

    2003-04-01

    The central aim of this work is to assess the spatial behaviour of critical depths for slope stability and the behaviour of their correlated variables in the soil-regolith transition along slope profiles over granite, migmatite and mica-schist parent materials in an humid tropical environment. In this way, we had making measures of shear strength for residual soils and regolith materials with soil "Cohron Sheargraph" apparatus and evaluated the shear stress tension behaviour at soil-regolith boundary along slope profiles, in each referred lithology. In the limit equilibrium approach applied here we adapt the infinite slope model for slope analysis in whole slope profile by means of finite element solution like in Fellenius or Bishop methods. In our case, we assume that the potential rupture surface occurs at soil-regolith or soil-rock boundary in slope material. For each slice, the factor of safety was calculated considering the value of shear strength (cohesion and friction) of material, soil-regolith boundary depth, soil moisture level content, slope gradient, top of subsurface flow gradient, apparent soil bulk density. The correlations showed the relative weight of cohesion, internal friction angle, apparent bulk density of soil materials and slope gradient variables with respect to the evaluation of critical depth behaviour for different simulated soil moisture content levels at slope profile scale. Some important results refer to the central role of behaviour of soil bulk-density variable along slope profile during soil evolution and in present day, because the intense clay production, mainly Kaolinite and Gibbsite at B and C-horizons, in the humid tropical environment. A increase in soil clay content produce a fall of friction angle and bulk density of material, specially when some montmorillonite or illite clay are present. We have observed too at threshold conditions, that a slight change in soil bulk-density value may disturb drastically the equilibrium of

  3. PB-Piedmont: A numerical model for predicting the movement of biological material near the ground at night.

    Science.gov (United States)

    Gary L. Achtemeier

    2000-01-01

    PB-Piedmont is a numerical model designed to simulate near-ground smoke movement at night under clear skies and near calm winds over irregular terrain characterized by ridge/valley elevation differences of the order of 50 m. Although the model was developed for monitoring smoke at night, the model is equally suitable for monitoring movement of agricultural odors and...

  4. Reduced order modelling techniques for mesh movement strategies as applied to fluid structure interactions

    CSIR Research Space (South Africa)

    Bogaers, Alfred EJ

    2010-01-01

    Full Text Available In this paper, we implement the method of Proper Orthogonal Decomposition (POD) to generate a reduced order model (ROM) of an optimization based mesh movement technique. In the study it is shown that POD can be used effectively to generate a ROM...

  5. Modeling moisture movement in revegetating waste heaps: 2. Application to oil shale wastes

    Science.gov (United States)

    Connell, L. D.; Bell, P. R.; Haverkamp, R.

    1993-05-01

    The application of a model for the movement of water within waste dumps, described in a previous paper, requires the estimation of a range of physical characteristics. Parameters relating to the transfer of liquid water, water vapor, heat, and air within the waste dump must be estimated in addition to surface parameters which determine the interaction between subsurface processs and the atmospheric boundary layer. Three different methods are used to estimate the hydraulic conductivity and moisture retentivity: an inverse analysis based on field measurements of moisture movement; an application of the instantaneous profile method; and the Haverkamp-Parlange method. The water vapor-air diffusivity and intrinsic permeability of air are estimated, as well as the thermal properties of the various waste materials. The model presented previously is refined through a series of sensitivity analyses and applied to simulate the water movement observed within a lysimeter. Model predictions were particularly sensitive to the surface roughness. Evaporation from a bare surface was found to be related primarily to the surface moisture content, most evaporation occurring directly after rainfall. The contribution of vapor transport to cumulative evaporation was not significant in comparison to the contribution of liquid flow, even for long periods of dry surface conditions. Finally, the model is applied to predict the moisture movement within waste dumps that could be expected from an oil shale-mining operation.

  6. Active controlled muscles in numerical model of human arm for movement in two degrees of freedom

    NARCIS (Netherlands)

    Budziszewski, P.; Nunen, E. van; Mordaka, J.K.; Kȩdzior, K.

    2008-01-01

    This paper describes the development of numerical model of human upper extremity able to perform movements and stabilization tasks in two degrees of freedom as a result of muscle activation controlled by a PID-based controller. These tasks are defined by functions of specified angle for every degree

  7. Creating a Double-Spring Model to Teach Chromosome Movement during Mitosis & Meiosis

    Science.gov (United States)

    Luo, Peigao

    2012-01-01

    The comprehension of chromosome movement during mitosis and meiosis is essential for understanding genetic transmission, but students often find this process difficult to grasp in a classroom setting. I propose a "double-spring model" that incorporates a physical demonstration and can be used as a teaching tool to help students understand this…

  8. Small Signal Modeling of Wind Farms

    DEFF Research Database (Denmark)

    Ebrahimzadeh, Esmaeil; Blaabjerg, Frede; Wang, Xiongfei

    2017-01-01

    In large power electronic systems like a wind farm, the mutual interactions between the control systems of the power converters can lead to various stability and power quality problems. In order to predict the system dynamic behavior, this paper presents an approach to model a wind farm as a Multi......-Input Multi-Output (MIMO) dynamic system, where the current control loops with Phase-Locked Loops (PLLs) are linearized around an operating point. Each sub-module of the wind farm is modeled as a 2×2 admittance matrix in dq-domain and all are combined together by using a dq nodal admittance matrix....... The frequency and damping of the oscillatory modes are calculated by finding the poles of the introduced MIMO matrix. Time-domain simulation results obtained from a 400-MW wind farm are used to verify the effectiveness of the presented model....

  9. A Single, Continuously Applied Control Policy for Modeling Reaching Movements with and without Perturbation.

    Science.gov (United States)

    Li, Zhe; Mazzoni, Pietro; Song, Sen; Qian, Ning

    2018-02-01

    It has been debated whether kinematic features, such as the number of peaks or decomposed submovements in a velocity profile, indicate the number of discrete motor impulses or result from a continuous control process. The debate is particularly relevant for tasks involving target perturbation, which can alter movement kinematics. To simulate such tasks, finite-horizon models require two preset movement durations to compute two control policies before and after the perturbation. Another model employs infinite- and finite-horizon formulations to determine, respectively, movement durations and control policies, which are updated every time step. We adopted an infinite-horizon optimal feedback control model that, unlike previous approaches, does not preset movement durations or use multiple control policies. It contains both control-dependent and independent noises in system dynamics, state-dependent and independent noises in sensory feedbacks, and different delays and noise levels for visual and proprioceptive feedbacks. We analytically derived an optimal solution that can be applied continuously to move an effector toward a target regardless of whether, when, or where the target jumps. This single policy produces different numbers of peaks and "submovements" in velocity profiles for different conditions and trials. Movements that are slower or perturbed later appear to have more submovements. The model is also consistent with the observation that subjects can perform the perturbation task even without detecting the target jump or seeing their hands during reaching. Finally, because the model incorporates Weber's law via a state representation relative to the target, it explains why initial and terminal visual feedback are, respectively, less and more effective in improving end-point accuracy. Our work suggests that the number of peaks or submovements in a velocity profile does not necessarily reflect the number of motor impulses and that the difference between

  10. A hidden Markov movement model for rapidly identifying behavioral states from animal tracks.

    Science.gov (United States)

    Whoriskey, Kim; Auger-Méthé, Marie; Albertsen, Christoffer M; Whoriskey, Frederick G; Binder, Thomas R; Krueger, Charles C; Mills Flemming, Joanna

    2017-04-01

    Electronic telemetry is frequently used to document animal movement through time. Methods that can identify underlying behaviors driving specific movement patterns can help us understand how and why animals use available space, thereby aiding conservation and management efforts. For aquatic animal tracking data with significant measurement error, a Bayesian state-space model called the first-Difference Correlated Random Walk with Switching (DCRWS) has often been used for this purpose. However, for aquatic animals, highly accurate tracking data are now becoming more common. We developed a new hidden Markov model (HMM) for identifying behavioral states from animal tracks with negligible error, called the hidden Markov movement model (HMMM). We implemented as the basis for the HMMM the process equation of the DCRWS, but we used the method of maximum likelihood and the R package TMB for rapid model fitting. The HMMM was compared to a modified version of the DCRWS for highly accurate tracks, the DCRWSNOME, and to a common HMM for animal tracks fitted with the R package moveHMM. We show that the HMMM is both accurate and suitable for multiple species by fitting it to real tracks from a grey seal, lake trout, and blue shark, as well as to simulated data. The HMMM is a fast and reliable tool for making meaningful inference from animal movement data that is ideally suited for ecologists who want to use the popular DCRWS implementation and have highly accurate tracking data. It additionally provides a groundwork for development of more complex modeling of animal movement with TMB. To facilitate its uptake, we make it available through the R package swim.

  11. Modelling non-Euclidean movement and landscape connectivity in highly structured ecological networks

    Science.gov (United States)

    Sutherland, Christopher; Fuller, Angela K.; Royle, J. Andrew

    2015-01-01

    Movement is influenced by landscape structure, configuration and geometry, but measuring distance as perceived by animals poses technical and logistical challenges. Instead, movement is typically measured using Euclidean distance, irrespective of location or landscape structure, or is based on arbitrary cost surfaces. A recently proposed extension of spatial capture-recapture (SCR) models resolves this issue using spatial encounter histories of individuals to calculate least-cost paths (ecological distance: Ecology, 94, 2013, 287) thereby relaxing the Euclidean assumption. We evaluate the consequences of not accounting for movement heterogeneity when estimating abundance in highly structured landscapes, and demonstrate the value of this approach for estimating biologically realistic space-use patterns and landscape connectivity.

  12. Oscillator-based assistance of cyclical movements: model-based and model-free approaches

    NARCIS (Netherlands)

    Ronsse, Renaud; Lenzi, Tommaso; Vitiello, Nicola; Koopman, Bram; van Asseldonk, Edwin H.F.; de Rossi, Stefano Marco Maria; van den Kieboom, Jesse; van der Kooij, Herman; Carozza, Maria Chiara; IJspeert, Auke Jan

    2011-01-01

    In this article, we propose a new method for providing assistance during cyclical movements. This method is trajectory-free, in the sense that it provides user assistance irrespective of the performed movement, and requires no other sensing than the assisting robot’s own encoders. The approach is

  13. A Bayesian Combined Model for Time-Dependent Turning Movement Proportions Estimation at Intersections

    Directory of Open Access Journals (Sweden)

    Pengpeng Jiao

    2014-01-01

    Full Text Available Time-dependent turning movement flows are very important input data for intelligent transportation systems but are impossible to be detected directly through current traffic surveillance systems. Existing estimation models have proved to be not accurate and reliable enough during all intervals. An improved way to address this problem is to develop a combined model framework that can integrate multiple submodels running simultaneously. This paper first presents a back propagation neural network model to estimate dynamic turning movements, as well as the self-adaptive learning rate approach and the gradient descent with momentum method for solving. Second, this paper develops an efficient Kalman filtering model and designs a revised sequential Kalman filtering algorithm. Based on the Bayesian method using both historical data and currently estimated results for error calibration, this paper further integrates above two submodels into a Bayesian combined model framework and proposes a corresponding algorithm. A field survey is implemented at an intersection in Beijing city to collect both time series of link counts and actual time-dependent turning movement flows, including historical and present data. The reported estimation results show that the Bayesian combined model is much more accurate and stable than other models.

  14. Effects of underestimating the kinematics of trunk rotation on simultaneous reaching movements: predictions of a biomechanical model.

    Science.gov (United States)

    Simoneau, Martin; Guillaud, Étienne; Blouin, Jean

    2013-06-12

    Rotation of the torso while reaching produces torques (e.g., Coriolis torque) that deviate the arm from its planned trajectory. To ensure an accurate reaching movement, the brain may take these perturbing torques into account during movement planning or, alternatively, it may correct hand trajectory during movement execution. Irrespective of the process selected, it is expected that an underestimation of trunk rotation would likely induce inaccurate shoulder and elbow torques, resulting in hand deviation. Nonetheless, it is still undetermined to what extent a small error in the perception of trunk rotations, translating into an inappropriate selection of motor commands, would affect reaching accuracy. To investigate, we adapted a biomechanical model (J Neurophysiol 89: 276-289, 2003) to predict the consequences of underestimating trunk rotations on right hand reaching movements performed during either clockwise or counter clockwise torso rotations. The results revealed that regardless of the degree to which the torso rotation was underestimated, the amplitude of hand deviation was much larger for counter clockwise rotations than for clockwise rotations. This was attributed to the fact that the Coriolis and centripetal joint torques were acting in the same direction during counter clockwise rotation yet in opposite directions during clockwise rotations, effectively cancelling each other out. These findings suggest that in order to anticipate and compensate for the interaction torques generated during torso rotation while reaching, the brain must have an accurate prediction of torso rotation kinematics. The present study proposes that when designing upper limb prostheses controllers, adding a sensor to monitor trunk kinematics may improve prostheses control and performance.

  15. SOLUTION OF MATHEMATICAL MODEL FOR TRACKED VEHICLE MOVEMENT UNDER DIFFERENT CONTROL ACTIONS

    Directory of Open Access Journals (Sweden)

    S. Volosnikov

    2017-06-01

    Full Text Available The paper presents a solution to the mathematical model of the caterpillar platform motion in the process of going into corner at various speed of movement. The presented model made it possible to obtain characteristic trajectories of a caterpillar platform in a turn for different road conditions and control actions. The «steering wheel» and «levers», which are most widely used in turn control systems, are considered as controls for the caterpillar platform.

  16. Small-scale models of multiring basins

    Science.gov (United States)

    Allemand, Pascal; Thomas, Pierre

    1999-07-01

    Small-scale sand-silicone simulations of multiring impact structures have been undertaken in order to understand the effects of the rheology of the lithosphere on the variability of natural multiring structures. For low sand-silicone thickness ratio (1:3), brittle strain is accommodated by spiral strike-slip faults. For higher sand-silicone ratios (1:1 or 2:1), an inner concentric ring affected by strike-slip faults is relayed by an external ring affected by concentric normal faults. The diameter of the inner ring decreases with the increase of the sand-silicone thickness ratio. It is suggested that the flexure of the brittle layer due to the silicone flow is responsible for the brittle strain field which is enhanced by the channel flow of the lower crust. The characteristic geometry of the intersection of conjugated strike-slip faults can be observed around large multiring basins on silicate crust such as Orientale on the Moon and on icy crust, such as Valhalla on Callisto and Gilgamesh on Ganymede. The strain field around these large craters is discussed in terms of mechanical properties of the lithospheres. On the Moon, large craters without relaxation faults, such as Imbrium are located on thin crust regions. The crust was too thin to have a ductile lower layer at the time of impact. Gilgamesh on Ganymede is surrounded mainly by strike-slip faults. Asgard on Callisto has the same diameter as Gilgamesh but is surrounded by concentric normal faults. The brittle-ductile thickness ratio is thus higher on Callisto than on Ganymede.

  17. Evaluation of the simulation robot for mandibular movements with the patient-specific 3-dimensional plaster model and mandibular movement data: clinical application of the physical simulation robot.

    Science.gov (United States)

    Ikawa, Tomoko; Ogawa, Takumi; Shigeta, Yuko; Hirabayashi, Rio; Fukushima, Shunji; Otake, Yoshito; Hattori, Asaki; Suzuki, Naoki

    2008-01-01

    We developed a multi-phase simulation system for patients with jaw deformity and dysfunction as a collaborate study between our departments. The intended application of the physical simulation robot was to evaluate its function based on well it quantitatively measured the movement of the individual patient. This physical simulation robot consists of a 6-degree-of-freedom robotic manipulator and a plaster model of patient-specific bone geometry. Each plaster model was mounted on the serial-articulated robotic manipulator. To establish the accuracy of the robot movement, the programmed movement of the robotic arm was validated using an optical tracking device. The results of the physical simulation robot corresponded with the data from the 4D analysis system. We could construct interactive relations between the 4D analysis system that was presented by virtual reality and the simulation robot which was constructed from physical simulation.

  18. A refined cellular automaton model to rectify impractical vehicular movement behavior

    Science.gov (United States)

    Lan, Lawrence W.; Chiou, Yu-Chiun; Lin, Zih-Shin; Hsu, Chih-Cheng

    2009-09-01

    When implementing cellular automata (CA) into a traffic simulation, one common defect yet to be rectified is the abrupt deceleration when vehicles encounter stationary obstacles or traffic jams. To be more in line with real world vehicular movement, this paper proposes a piecewise-linear movement to replace the conventional particle-hopping movement adopted in most previous CA models. Upon this adjustment and coupled with refined cell system, a new CA model is developed using the rationale of Forbes’ et al. car-following concept. The proposed CA model is validated on a two-lane freeway mainline context. It shows that this model can fix the unrealistic deceleration behaviors, and thus can reflect genuine driver behavior in the real world. The model is also capable of revealing Kerner’s three-phase traffic patterns and phase transitions among them. Furthermore, the proposed CA model is applied to simulate a highway work zone wherein traffic efficiency (maximum flow rates) and safety (speed deviations) impacted by various control schemes are tested.

  19. Experimental Evaluation of Balance Prediction Models for Sit-to-Stand Movement in the Sagittal Plane

    Directory of Open Access Journals (Sweden)

    Oscar David Pena Cabra

    2013-01-01

    Full Text Available Evaluation of balance control ability would become important in the rehabilitation training. In this paper, in order to make clear usefulness and limitation of a traditional simple inverted pendulum model in balance prediction in sit-to-stand movements, the traditional simple model was compared to an inertia (rotational radius variable inverted pendulum model including multiple-joint influence in the balance predictions. The predictions were tested upon experimentation with six healthy subjects. The evaluation showed that the multiple-joint influence model is more accurate in predicting balance under demanding sit-to-stand conditions. On the other hand, the evaluation also showed that the traditionally used simple inverted pendulum model is still reliable in predicting balance during sit-to-stand movement under non-demanding (normal condition. Especially, the simple model was shown to be effective for sit-to-stand movements with low center of mass velocity at the seat-off. Moreover, almost all trajectories under the normal condition seemed to follow the same control strategy, in which the subjects used extra energy than the minimum one necessary for standing up. This suggests that the safety considerations come first than the energy efficiency considerations during a sit to stand, since the most energy efficient trajectory is close to the backward fall boundary.

  20. A dynamic model of the knee and lower limb for simulating rising movements.

    Science.gov (United States)

    Shelburne, Kevin B; Pandy, Marcus G

    2002-04-01

    A two-dimensional dynamical model of the human body was developed and used to simulate muscle and knee-ligament loading during a fast rising movement. The hip, ankle, and toes were each modeled as a simple hinge joint. Relative movements of the femur, tibia, and patella in the sagittal plane were described using a more detailed representation of the knee. The geometry of the model bones was adapted from cadaver data. Eleven elastic elements described the geometric and mechanical properties of the knee ligaments and joint capsule. The patella was assumed to be massless. Smooth hypersurfaces were constructed and used to calculate the position and orientation of the patella during a forward integration of the model. Each hypersurface was formed by applying the principle of static equilibrium to approximate patellofemoral mechanics during the simulation. The model was actuated by 22 musculotendinous units, each unit represented as a three-element muscle in series with tendon. A first-order process was assumed to model muscle excitation-contraction dynamics. Dynamic optimization theory was used to calculate the pattern of muscle excitations that produces a coordinated rising movement from an initial squatting position in minimum time. The calculations support the contention that squatting is a relatively safe exercise for rehabilitation following ACL reconstruction. ACL forces remain less than 20 N for the duration of the task.

  1. Experimental Evaluation of Balance Prediction Models for Sit-to-Stand Movement in the Sagittal Plane

    Science.gov (United States)

    Pena Cabra, Oscar David; Watanabe, Takashi

    2013-01-01

    Evaluation of balance control ability would become important in the rehabilitation training. In this paper, in order to make clear usefulness and limitation of a traditional simple inverted pendulum model in balance prediction in sit-to-stand movements, the traditional simple model was compared to an inertia (rotational radius) variable inverted pendulum model including multiple-joint influence in the balance predictions. The predictions were tested upon experimentation with six healthy subjects. The evaluation showed that the multiple-joint influence model is more accurate in predicting balance under demanding sit-to-stand conditions. On the other hand, the evaluation also showed that the traditionally used simple inverted pendulum model is still reliable in predicting balance during sit-to-stand movement under non-demanding (normal) condition. Especially, the simple model was shown to be effective for sit-to-stand movements with low center of mass velocity at the seat-off. Moreover, almost all trajectories under the normal condition seemed to follow the same control strategy, in which the subjects used extra energy than the minimum one necessary for standing up. This suggests that the safety considerations come first than the energy efficiency considerations during a sit to stand, since the most energy efficient trajectory is close to the backward fall boundary. PMID:24187580

  2. The rat as a model for orthodontic tooth movement--a critical review and a proposed solution.

    NARCIS (Netherlands)

    Ren, Y.; Maltha, J.C.; Kuijpers-Jagtman, A.M.

    2004-01-01

    The aims of this study were to perform a systematic review of the use of rats as a model for experimental tooth movement, to give a critical evaluation of the use of elastics as a force delivery system, and to describe a newly designed well-defined model for tooth movement in rats. The literature

  3. The rat as a model for orthodontic tooth movement--a critical review and a proposed solution

    NARCIS (Netherlands)

    Ren, Yijin; Maltha, Jaap C; Kuijpers-Jagtman, Anne Marie

    2004-01-01

    The aims of this study were to perform a systematic review of the use of rats as a model for experimental tooth movement, to give a critical evaluation of the use of elastics as a force delivery system, and to describe a newly designed well-defined model for tooth movement in rats. The literature

  4. Modeling the Scheduling of Eye Movements and Manual Responses in Performing a Sequence of Discrete Tasks

    Science.gov (United States)

    Wu, Shu-Chieh; Remington, Roger W.; Lewis, Richard

    2006-01-01

    Common tasks in daily life are often accomplished by a sequence of actions that interleave information acquisition through the eyes and action execution by the hands. How are eye movements coordinated with the release of manual responses and how may their coordination be represented at the level of component mental operations? We have previously presented data from a typing-like task requiring separate choice responses to a series of five stimuli. We found a consistent pattern of results in both motor and ocular timing, and hypothesized possible relationships among underlying components. Here we report a model of that task, which demonstrates how the observed timing of eye movements to successive stimuli could be accounted for by assuming systems: an open-loop system generating saccades at a periodic rate, and a closed-loop system commanding a saccade based on stimulus processing. We relate this model to models of reading and discuss the motivation for dual control.

  5. Consistently modeling the same movement strategy is more important than model skill level in observational learning contexts.

    Science.gov (United States)

    Buchanan, John J; Dean, Noah

    2014-02-01

    The experiment undertaken was designed to elucidate the impact of model skill level on observational learning processes. The task was bimanual circle tracing with a 90° relative phase lead of one hand over the other hand. Observer groups watched videos of either an instruction model, a discovery model, or a skilled model. The instruction and skilled model always performed the task with the same movement strategy, the right-arm traced clockwise and the left-arm counterclockwise around circle templates with the right-arm leading. The discovery model used several movement strategies (tracing-direction/hand-lead) during practice. Observation of the instruction and skilled model provided a significant benefit compared to the discovery model when performing the 90° relative phase pattern in a post-observation test. The observers of the discovery model had significant room for improvement and benefited from post-observation practice of the 90° pattern. The benefit of a model is found in the consistency with which that model uses the same movement strategy, and not within the skill level of the model. It is the consistency in strategy modeled that allows observers to develop an abstract perceptual representation of the task that can be implemented into a coordinated action. Theoretically, the results show that movement strategy information (relative motion direction, hand lead) and relative phase information can be detected through visual perception processes and be successfully mapped to outgoing motor commands within an observational learning context. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Assessing the impact of marine wind farms on birds through movement modelling.

    Science.gov (United States)

    Masden, Elizabeth A; Reeve, Richard; Desholm, Mark; Fox, Anthony D; Furness, Robert W; Haydon, Daniel T

    2012-09-07

    Advances in technology and engineering, along with European Union renewable energy targets, have stimulated a rapid growth of the wind power sector. Wind farms contribute to carbon emission reductions, but there is a need to ensure that these structures do not adversely impact the populations that interact with them, particularly birds. We developed movement models based on observed avoidance responses of common eider Somateria mollissima to wind farms to predict, and identify potential measures to reduce, impacts. Flight trajectory data that were collected post-construction of the Danish Nysted offshore wind farm were used to parameterize competing models of bird movements around turbines. The model most closely fitting the observed data incorporated individual variation in the minimum distance at which birds responded to the turbines. We show how such models can contribute to the spatial planning of wind farms by assessing their extent, turbine spacing and configurations on the probability of birds passing between the turbines. Avian movement models can make new contributions to environmental assessments of wind farm developments, and provide insights into how to reduce impacts that can be identified at the planning stage.

  7. inverse gaussian model for small area estimation via gibbs sampling

    African Journals Online (AJOL)

    ADMIN

    (1994) extended the work by Fries and. Bhattacharyya (1983) to include the maximum likelihood analysis of the two-factor inverse. Gaussian model for the unbalanced and interaction case for the estimation of small area parameters in finite populations. The object of this article is to develop a Bayesian approach for small ...

  8. Inverse Gaussian model for small area estimation via Gibbs sampling

    African Journals Online (AJOL)

    We present a Bayesian method for estimating small area parameters under an inverse Gaussian model. The method is extended to estimate small area parameters for finite populations. The Gibbs sampler is proposed as a mechanism for implementing the Bayesian paradigm. We illustrate the method by application to ...

  9. Small larvae in large rivers: observations on downstream movement of European grayling Thymallus thymallus during early life stages.

    Science.gov (United States)

    Van Leeuwen, C H A; Dokk, T; Haugen, T O; Kiffney, P M; Museth, J

    2017-06-01

    Behaviour of early life stages of the salmonid European grayling Thymallus thymallus was investigated by assessing the timing of larval downstream movement from spawning areas, the depth at which larvae moved and the distribution of juvenile fish during summer in two large connected river systems in Norway. Trapping of larvae moving downstream and electrofishing surveys revealed that T. thymallus larvae emerging from the spawning gravel moved downstream predominantly during the night, despite light levels sufficient for orientation in the high-latitude study area. Larvae moved in the water mostly at the bottom layer close to the substratum, while drifting debris was caught in all layers of the water column. Few young-of-the-year still resided close to the spawning areas in autumn, suggesting large-scale movement (several km). Together, these observations show that there may be a deliberate, active component to downstream movement of T. thymallus during early life stages. This research signifies the importance of longitudinal connectivity for T. thymallus in Nordic large river systems. Human alterations of flow regimes and the construction of reservoirs for hydropower may not only affect the movement of adult fish, but may already interfere with active movement behaviour of fish during early life stages. © 2017 The Fisheries Society of the British Isles.

  10. Oscillator-based assistance of cyclical movements: model-based and model-free approaches

    OpenAIRE

    Ronsse, Renaud; Lenzi, Tommaso; Vitiello, Nicola; Koopman, Bram; van Asseldonk, Edwin; De Rossi, Stefano Marco Maria; van den Kieboom, Jesse; van der Kooij, Herman; Carrozza, Maria Chiara; Ijspeert, Auke Jan

    2011-01-01

    In this article, we propose a new method for providing assistance during cyclical movements. This method is trajectory-free, in the sense that it provides user assistance irrespective of the performed movement, and requires no other sensing than the assisting robot's own encoders. The approach is based on adaptive oscillators, i.e., mathematical tools that are capable of learning the high level features (frequency, envelope, etc.) of a periodic input signal. Here we present two experiments th...

  11. State-Space Modelling of the Drivers of Movement Behaviour in Sympatric Species.

    Directory of Open Access Journals (Sweden)

    F J Pérez-Barbería

    Full Text Available Understanding animal movement behaviour is key to furthering our knowledge on intra- and inter-specific competition, group cohesion, energy expenditure, habitat use, the spread of zoonotic diseases or species management. We used a radial basis function surface approximation subject to minimum description length constraint to uncover the state-space dynamical systems from time series data. This approximation allowed us to infer structure from a mathematical model of the movement behaviour of sheep and red deer, and the effect of density, thermal stress and vegetation type. Animal movement was recorded using GPS collars deployed in sheep and deer grazing a large experimental plot in winter and summer. Information on the thermal stress to which animals were exposed was estimated using the power consumption of mechanical heated models and meteorological records of a network of stations in the plot. Thermal stress was higher in deer than in sheep, with less differences between species in summer. Deer travelled more distance than sheep, and both species travelled more in summer than in winter; deer travel distance showed less seasonal differences than sheep. Animal movement was better predicted in deer than in sheep and in winter than in summer; both species showed a swarming behaviour in group cohesion, stronger in deer. At shorter separation distances swarming repulsion was stronger between species than within species. At longer separation distances inter-specific attraction was weaker than intra-specific; there was a positive density-dependent effect on swarming, and stronger in deer than in sheep. There was not clear evidence which species attracted or repelled the other; attraction between deer at long separation distances was stronger when the model accounted for thermal stress, but in general the dynamic movement behaviour was hardly affected by the thermal stress. Vegetation type affected intra-species interactions but had little effect on

  12. State-Space Modelling of the Drivers of Movement Behaviour in Sympatric Species.

    Science.gov (United States)

    Pérez-Barbería, F J; Small, M; Hooper, R J; Aldezabal, A; Soriguer-Escofet, R; Bakken, G S; Gordon, I J

    2015-01-01

    Understanding animal movement behaviour is key to furthering our knowledge on intra- and inter-specific competition, group cohesion, energy expenditure, habitat use, the spread of zoonotic diseases or species management. We used a radial basis function surface approximation subject to minimum description length constraint to uncover the state-space dynamical systems from time series data. This approximation allowed us to infer structure from a mathematical model of the movement behaviour of sheep and red deer, and the effect of density, thermal stress and vegetation type. Animal movement was recorded using GPS collars deployed in sheep and deer grazing a large experimental plot in winter and summer. Information on the thermal stress to which animals were exposed was estimated using the power consumption of mechanical heated models and meteorological records of a network of stations in the plot. Thermal stress was higher in deer than in sheep, with less differences between species in summer. Deer travelled more distance than sheep, and both species travelled more in summer than in winter; deer travel distance showed less seasonal differences than sheep. Animal movement was better predicted in deer than in sheep and in winter than in summer; both species showed a swarming behaviour in group cohesion, stronger in deer. At shorter separation distances swarming repulsion was stronger between species than within species. At longer separation distances inter-specific attraction was weaker than intra-specific; there was a positive density-dependent effect on swarming, and stronger in deer than in sheep. There was not clear evidence which species attracted or repelled the other; attraction between deer at long separation distances was stronger when the model accounted for thermal stress, but in general the dynamic movement behaviour was hardly affected by the thermal stress. Vegetation type affected intra-species interactions but had little effect on inter

  13. Prediction model of oil slick movement in the Nemunas river (Lithuania)

    International Nuclear Information System (INIS)

    Ignatavicius, G.; Sakalauskiene, G.

    2005-01-01

    Full text : Oil products (petroleum products) were used to fuel airplanes, cars and trucks, to heat the houses, and to make products like medicines and plastics. Even petroleum products make life easier, but extraction, production, movement, and use of them cause environment pollution in air, soil and water. There are several sources of water pollution, like ship traffic, oil refineries and other industry, which together deteriorate the river water quality and disturb the life within rivers and lakes. Rain as it falls through the air, or drains from urban areas and farmland, absorbs contaminants. The model has been developed based on the solution of the governing partial differential equations of flow and oil products for predicting the oil slick transformation in the rivers. In the present model, the processes included are advection, diffusion, evaporation and dissolution. The model can take into account all losses of oil products during the movement of oil slick. It can be used either as a real time basis to predict the movement of oil spill or as a scenario model to analyse to possible impact of accidental oil spill in to the rivers

  14. A model for altered neural network dynamics related to prehension movements in Parkinson disease.

    Science.gov (United States)

    Molina-Vilaplana, J; Contreras-Vidal, J L; Herrero-Ezquerro, M T; Lopez-Coronado, J

    2009-04-01

    In this paper, we present a neural network model of the interactions between cortex and the basal ganglia during prehensile movements. Computational neuroscience methods are used to explore the hypothesis that the altered kinematic patterns observed in Parkinson's disease patients performing prehensile movements is mainly due to an altered neuronal activity located in the networks of cholinergic (ACh) interneurons of the striatum. These striatal cells, under a strong influence of the dopaminergic system, significantly contribute to the neural processing within the striatum and in the cortico-basal ganglia loops. In order to test this hypothesis, a large-scale model of neural interactions in the basal ganglia has been integrated with previous models accounting for the cortical organization of goal directed reaching and grasping movements in normal and perturbed conditions. We carry out a discussion of the model hypothesis validation by providing a control engineering analysis and by comparing results of real experiments with our simulation results in conditions resembling these original experiments.

  15. Validation of a spatial–temporal soil water movement and plant water uptake model

    KAUST Repository

    HEPPELL, J.

    2014-06-01

    © 2014, (publisher). All rights reserved. Management and irrigation of plants increasingly relies on accurate mathematical models for the movement of water within unsaturated soils. Current models often use values for water content and soil parameters that are averaged over the soil profile. However, many applications require models to more accurately represent the soil–plant–atmosphere continuum, in particular, water movement and saturation within specific parts of the soil profile. In this paper a mathematical model for water uptake by a plant root system from unsaturated soil is presented. The model provides an estimate of the water content level within the soil at different depths, and the uptake of water by the root system. The model was validated using field data, which include hourly water content values at five different soil depths under a grass/herb cover over 1 year, to obtain a fully calibrated system for plant water uptake with respect to climate conditions. When compared quantitatively to a simple water balance model, the proposed model achieves a better fit to the experimental data due to its ability to vary water content with depth. To accurately model the water content in the soil profile, the soil water retention curve and saturated hydraulic conductivity needed to vary with depth.

  16. Sole vibration improves locomotion through the recovery of joint movements in a mouse cast model.

    Directory of Open Access Journals (Sweden)

    Atsushi Doi

    Full Text Available We investigated the effects of a vibratory stimulus on the plantar surface of the hind limb for motor, sensory, and locomotive function using a mouse cast model. The right knee joint of C57BL/6 male mice (7 weeks, 20 g, n = 31 was flexed with aluminum splint and tape for 6 weeks. These mice were randomly divided into 2 groups (control group, n = 11 and vibration group, n = 12. The mice in the vibration group received vibration on the sole of the ankle for 15 minutes per day, 5 days per week. After the knee joint cast was removed, we measured the range of motion (ROM of both knee and ankle joints and the sensory threshold of the sole. Further, both walking and swimming movements were analyzed with a digital video. The sole vibration did not affect the passive ROM of the knee joint and sensory threshold after cast removal. However, it increased the ankle dorsiflexion range and improved free walking, swimming, and active movement of the knee joint. In conclusion, we show that the vibration recovered both walking and swimming movements, which resulted from improvements in both the passive ankle dorsiflexion and active knee movement.

  17. Modeling and simulation of high-speed passenger train movements in the rail line

    Science.gov (United States)

    Cao, Cheng-Xuan; Xu, Yan; Li, Ke-Ping

    2013-06-01

    In this paper, we propose a new formula of the real-time minimum safety headway based on the relative velocity of consecutive trains and present a dynamic model of high-speed passenger train movements in the rail line based on the proposed formula of the minimum safety headway. Moreover, we provide the control strategies of the high-speed passenger train operations based on the proposed formula of the real-time minimum safety headway and the dynamic model of high-speed passenger train movements. The simulation results demonstrate that the proposed control strategies of the passenger train operations can greatly reduce the delay propagation in the high-speed rail line when a random delay occurs.

  18. Linking spring phenology with mechanistic models of host movement to predict disease transmission risk

    Science.gov (United States)

    Merkle, Jerod A.; Cross, Paul C.; Scurlock, Brandon M.; Cole, Eric K.; Courtemanch, Alyson B.; Dewey, Sarah R.; Kauffman, Matthew J.

    2018-01-01

    Disease models typically focus on temporal dynamics of infection, while often neglecting environmental processes that determine host movement. In many systems, however, temporal disease dynamics may be slow compared to the scale at which environmental conditions alter host space-use and accelerate disease transmission.Using a mechanistic movement modelling approach, we made space-use predictions of a mobile host (elk [Cervus Canadensis] carrying the bacterial disease brucellosis) under environmental conditions that change daily and annually (e.g., plant phenology, snow depth), and we used these predictions to infer how spring phenology influences the risk of brucellosis transmission from elk (through aborted foetuses) to livestock in the Greater Yellowstone Ecosystem.Using data from 288 female elk monitored with GPS collars, we fit step selection functions (SSFs) during the spring abortion season and then implemented a master equation approach to translate SSFs into predictions of daily elk distribution for five plausible winter weather scenarios (from a heavy snow, to an extreme winter drought year). We predicted abortion events by combining elk distributions with empirical estimates of daily abortion rates, spatially varying elk seroprevelance and elk population counts.Our results reveal strong spatial variation in disease transmission risk at daily and annual scales that is strongly governed by variation in host movement in response to spring phenology. For example, in comparison with an average snow year, years with early snowmelt are predicted to have 64% of the abortions occurring on feedgrounds shift to occurring on mainly public lands, and to a lesser extent on private lands.Synthesis and applications. Linking mechanistic models of host movement with disease dynamics leads to a novel bridge between movement and disease ecology. Our analysis framework offers new avenues for predicting disease spread, while providing managers tools to proactively mitigate

  19. Peculiarity by Modeling of the Control Rod Movement by the Kalinin-3 Benchmark

    International Nuclear Information System (INIS)

    Nikonov, S. P.; Velkov, K.; Pautz, A.

    2010-01-01

    The paper presents an important part of the results of the OECD/NEA benchmark transient 'Switching off one main circulation pump at nominal power' analyzed as a boundary condition problem by the coupled system code ATHLET-BIPR-VVER. Some observations and comparisons with measured data for integral reactor parameters are discussed. Special attention is paid on the modeling and comparisons performed for the control rod movement and the reactor power history. (Authors)

  20. Modeling of temperatures by using the algorithm of queue burning movement in the UCG Process

    Directory of Open Access Journals (Sweden)

    Milan Durdán

    2015-10-01

    Full Text Available In this contribution, a proposal of the system for indirect measurement temperatures in the underground coal gasification (UCG process is presented. A two-dimensional solution results from the Fourier partial differential equation of the heat conduction was used for the calculation of the temperature field in the real coal seam. An algorithm of queue burning movement for modeling the boundary conditions in gasification channel was created. Indirect measurement temperatures system was verified in the laboratory conditions.

  1. Simulating large-scale pedestrian movement using CA and event driven model: Methodology and case study

    Science.gov (United States)

    Li, Jun; Fu, Siyao; He, Haibo; Jia, Hongfei; Li, Yanzhong; Guo, Yi

    2015-11-01

    Large-scale regional evacuation is an important part of national security emergency response plan. Large commercial shopping area, as the typical service system, its emergency evacuation is one of the hot research topics. A systematic methodology based on Cellular Automata with the Dynamic Floor Field and event driven model has been proposed, and the methodology has been examined within context of a case study involving the evacuation within a commercial shopping mall. Pedestrians walking is based on Cellular Automata and event driven model. In this paper, the event driven model is adopted to simulate the pedestrian movement patterns, the simulation process is divided into normal situation and emergency evacuation. The model is composed of four layers: environment layer, customer layer, clerk layer and trajectory layer. For the simulation of movement route of pedestrians, the model takes into account purchase intention of customers and density of pedestrians. Based on evacuation model of Cellular Automata with Dynamic Floor Field and event driven model, we can reflect behavior characteristics of customers and clerks at the situations of normal and emergency evacuation. The distribution of individual evacuation time as a function of initial positions and the dynamics of the evacuation process is studied. Our results indicate that the evacuation model using the combination of Cellular Automata with Dynamic Floor Field and event driven scheduling can be used to simulate the evacuation of pedestrian flows in indoor areas with complicated surroundings and to investigate the layout of shopping mall.

  2. Holonic Business Process Modeling in Small to Medium Sized Enterprises

    Directory of Open Access Journals (Sweden)

    Nur Budi Mulyono

    2012-01-01

    Full Text Available Holonic modeling analysis which is the application of system thinking in design, manage, and improvement, is used in a novel context for business process modeling. An approach and techniques of holon and holarchies is presented specifically for small and medium sized enterprise process modeling development. The fitness of the approach is compared with well known reductionist or task breakdown approach. The strength and weaknesses of the holonic modeling is discussed with illustrating case example in term of its suitability for an Indonesia’s small and medium sized industry. The novel ideas in this paper have great impact on the way analyst should perceive business process. Future research is applying the approach in supply chain context.Key words: Business process, holonic modeling, operations management, small to medium sized enterprise

  3. An integrative model for the neural mechanism of Eye Movement Desensitization and Reprocessing (EMDR

    Directory of Open Access Journals (Sweden)

    Olivier A. Coubard

    2016-04-01

    Full Text Available Since the seminal report by Shapiro that bilateral stimulation induces cognitive and emotional changes, twenty-six years of basic and clinical research have examined the effects of Eye Movement Desensitization and Reprocessing (EMDR in anxiety disorders, particularly in Post-Traumatic Stress Disorder (PTSD. The present article aims at better understanding EMDR neural mechanism. I first review procedural aspects of EMDR protocol and theoretical hypothesis about EMDR effects, and develop the reasons why the scientific community is still divided about EMDR. I then slide from psychology to physiology describing eye movements/emotion interaction from the physiological viewpoint, and introduce theoretical and technical tools used in movement research to re-examine EMDR neural mechanism. Using a recent physiological model for the neuropsychological architecture of motor and cognitive control, the Threshold Interval Modulation with Early Release-Rate of rIse Deviation with Early Release – TIMER-RIDER – model, I explore how attentional control and bilateral stimulation may participate to EMDR effects. These effects may be obtained by two processes acting in parallel: (i activity level enhancement of attentional control component; and (ii bilateral stimulation in any sensorimotor modality, both resulting in lower inhibition enabling dysfunctional information to be processed and anxiety to be reduced. The TIMER-RIDER model offers quantitative predictions about EMDR effects for future research about its underlying physiological mechanisms.

  4. An Integrative Model for the Neural Mechanism of Eye Movement Desensitization and Reprocessing (EMDR).

    Science.gov (United States)

    Coubard, Olivier A

    2016-01-01

    Since the seminal report by Shapiro that bilateral stimulation induces cognitive and emotional changes, 26 years of basic and clinical research have examined the effects of Eye Movement Desensitization and Reprocessing (EMDR) in anxiety disorders, particularly in post-traumatic stress disorder (PTSD). The present article aims at better understanding EMDR neural mechanism. I first review procedural aspects of EMDR protocol and theoretical hypothesis about EMDR effects, and develop the reasons why the scientific community is still divided about EMDR. I then slide from psychology to physiology describing eye movements/emotion interaction from the physiological viewpoint, and introduce theoretical and technical tools used in movement research to re-examine EMDR neural mechanism. Using a recent physiological model for the neuropsychological architecture of motor and cognitive control, the Threshold Interval Modulation with Early Release-Rate of rIse Deviation with Early Release (TIMER-RIDER)-model, I explore how attentional control and bilateral stimulation may participate to EMDR effects. These effects may be obtained by two processes acting in parallel: (i) activity level enhancement of attentional control component; and (ii) bilateral stimulation in any sensorimotor modality, both resulting in lower inhibition enabling dysfunctional information to be processed and anxiety to be reduced. The TIMER-RIDER model offers quantitative predictions about EMDR effects for future research about its underlying physiological mechanisms.

  5. A modeling investigation of vowel-to-vowel movement planning in acoustic and muscle spaces

    Science.gov (United States)

    Zandipour, Majid

    The primary objective of this research was to explore the coordinate space in which speech movements are planned. A two dimensional biomechanical model of the vocal tract (tongue, lips, jaw, and pharynx) was constructed based on anatomical and physiological data from a subject. The model transforms neural command signals into the actions of muscles. The tongue was modeled by a 221-node finite element mesh. Each of the eight tongue muscles defined within the mesh was controlled by a virtual muscle model. The other vocal-tract components were modeled as simple 2nd-order systems. The model's geometry was adapted to a speaker, using MRI scans of the speaker's vocal tract. The vocal tract model, combined with an adaptive controller that consisted of a forward model (mapping 12-dimensional motor commands to a 64-dimensional acoustic spectrum) and an inverse model (mapping acoustic trajectories to motor command trajectories), was used to simulate and explore the implications of two planning hypotheses: planning in motor space vs. acoustic space. The acoustic, kinematic, and muscle activation (EMG) patterns of vowel-to-vowel sequences generated by the model were compared to data from the speaker whose acoustic, kinematic and EMG were also recorded. The simulation results showed that: (a) modulations of the motor commands effectively accounted for the effects of speaking rate on EMG, kinematic, and acoustic outputs; (b) the movement and acoustic trajectories were influenced by vocal tract biomechanics; and (c) both planning schemes produced similar articulatory movement, EMG, muscle length, force, and acoustic trajectories, which were also comparable to the subject's data under normal speaking conditions. In addition, the effects of a bite-block on measured EMG, kinematics and formants were simulated by the model. Acoustic planning produced successful simulations but motor planning did not. The simulation results suggest that with somatosensory feedback but no auditory

  6. A Novel Rat Model of Orthodontic Tooth Movement Using Temporary Skeletal Anchorage Devices: 3D Finite Element Analysis and In Vivo Validation

    Directory of Open Access Journals (Sweden)

    Neelambar Kaipatur

    2014-01-01

    Full Text Available The aim of this animal study was to develop a model of orthodontic tooth movement using a microimplant as a TSAD in rodents. A finite element model of the TSAD in alveolar bone was built using μCT images of rat maxilla to determine the von Mises stresses and displacement in the alveolar bone surrounding the TSAD. For in vivo validation of the FE model, Sprague-Dawley rats (n=25 were used and a Stryker 1.2 × 3 mm microimplant was inserted in the right maxilla and used to protract the right first permanent molar using a NiTi closed coil spring. Tooth movement measurements were taken at baseline, 4 and 8 weeks. At 8 weeks, animals were euthanized and tissues were analyzed by histology and EPMA. FE modeling showed maximum von Mises stress of 45 Mpa near the apex of TSAD but the average von Mises stress was under 25 Mpa. Appreciable tooth movement of 0.62 ± 0.04 mm at 4 weeks and 1.99 ± 0.14 mm at 8 weeks was obtained. Histological and EPMA results demonstrated no active bone remodeling around the TSAD at 8 weeks depicting good secondary stability. This study provided evidence that protracted tooth movement is achieved in small animals using TSADs.

  7. A Novel Rat Model of Orthodontic Tooth Movement Using Temporary Skeletal Anchorage Devices: 3D Finite Element Analysis and In Vivo Validation.

    Science.gov (United States)

    Kaipatur, Neelambar; Wu, Yuchin; Adeeb, Samer; Stevenson, Thomas; Major, Paul; Doschak, Michael

    2014-01-01

    The aim of this animal study was to develop a model of orthodontic tooth movement using a microimplant as a TSAD in rodents. A finite element model of the TSAD in alveolar bone was built using μCT images of rat maxilla to determine the von Mises stresses and displacement in the alveolar bone surrounding the TSAD. For in vivo validation of the FE model, Sprague-Dawley rats (n = 25) were used and a Stryker 1.2 × 3 mm microimplant was inserted in the right maxilla and used to protract the right first permanent molar using a NiTi closed coil spring. Tooth movement measurements were taken at baseline, 4 and 8 weeks. At 8 weeks, animals were euthanized and tissues were analyzed by histology and EPMA. FE modeling showed maximum von Mises stress of 45 Mpa near the apex of TSAD but the average von Mises stress was under 25 Mpa. Appreciable tooth movement of 0.62 ± 0.04 mm at 4 weeks and 1.99 ± 0.14 mm at 8 weeks was obtained. Histological and EPMA results demonstrated no active bone remodeling around the TSAD at 8 weeks depicting good secondary stability. This study provided evidence that protracted tooth movement is achieved in small animals using TSADs.

  8. Movement Speed Models of Natural Grasp and Release Used for an Industrial Robot Equipped with a Gripper

    Science.gov (United States)

    Stoica, Mihai; Calangiu, Gabriela Andreea; Sisak, Francisc

    In this paper, movement speed models of a robotic manipulator are presented according to the mode of operation of the human hand, when it wants to grasp and release an object. In order to develop the models, measurements on a human agent were required regarding the movement coordinates of his hand. The movement patterns have been approximated on the intervals, using first and second degree functions. The speeds were obtained by deriving these functions. The models obtained are generally presented; for their implementation in models applied for a certain robot, specific changes from case to case have to be made.

  9. Volt-time characteristics of small airgaps with Hyperbolic model

    Energy Technology Data Exchange (ETDEWEB)

    Venkatesan, S. [Cardiff University, School of Engineering, Queens Building, The Parade, Cardiff, Wales CF24 3AA (United Kingdom); Usa, S. [Cardiff University, School of Engineering, Queens Building, The Parade, Cardiff, Wales CF24 3AA (United Kingdom); Division of High Voltage Engineering, Anna University, Chennai - 600025 (India)

    2010-07-15

    An experimental investigation of the volt-time characteristics of small airgaps is performed. A Hyperbolic model is proposed to account for the results. The constants of the model have a direct bearing on parameters of the Disruptive Effect model for breakdown with non-standard Lightning Impulses (LIs). Analyses with uniform and non-uniform electrodes show their effect on the Hyperbolic model parameters. (author)

  10. Holonic Business Process Modeling in Small to Medium Sized Enterprises

    OpenAIRE

    Nur Budi Mulyono; Tezar Yuliansyah Saputra; Nur Arief Rahmatsyah

    2012-01-01

    Holonic modeling analysis which is the application of system thinking in design, manage, and improvement, is used in a novel context for business process modeling. An approach and techniques of holon and holarchies is presented specifically for small and medium sized enterprise process modeling development. The fitness of the approach is compared with well known reductionist or task breakdown approach. The strength and weaknesses of the holonic modeling is discussed with illustrating case exa...

  11. Small Signal Audiosusceptibility Model for Series Resonant Converter

    OpenAIRE

    G., Subhash Joshi T.; John, Vinod

    2018-01-01

    Models that accurately predict the output voltage ripple magnitude are essential for applications with stringent performance target for it. Impact of dc input ripple on the output ripple for a Series Resonant Converter (SRC) using discrete domain exact discretization modelling method is analysed in this paper. A novel discrete state space model along with a small signal model for SRC considering 3 state variables is presented. The audiosusceptibility (AS) transfer function which relates the i...

  12. An Institutionalist Explanation of the Evolution of Taiwan’s Disability Movement: From the Charity Model to the Social Model

    Directory of Open Access Journals (Sweden)

    I-lun Tsai

    2010-01-01

    Full Text Available In this article, we analyze the process of institutional change in Taiwan’s disability field by focusing on the role of social movements. An institutional perspective emphasizes how a particular logic in an organizational field generates formal and informal institutions that define how persons with disabilities are treated in a society. Before the 1990s, the charity model was dominant, and later it came to be challenged by the disability movement, which advocated for the social model. We argue that the transition to a social model was a major achievement by disability organizations, which successfully combined the dual roles of advocate and service provider. By making strategic use of welfare privatization in the 1990s, they were able to mobilize a series of lobbying campaigns. Their efforts culminated in the passing of the Physically and Mentally Disabled Citizens Protection Act in 1997, which marked the beginning of the social model in Taiwan.

  13. Oscillator-based assistance of cyclical movements: model-based and model-free approaches.

    Science.gov (United States)

    Ronsse, Renaud; Lenzi, Tommaso; Vitiello, Nicola; Koopman, Bram; van Asseldonk, Edwin; De Rossi, Stefano Marco Maria; van den Kieboom, Jesse; van der Kooij, Herman; Carrozza, Maria Chiara; Ijspeert, Auke Jan

    2011-10-01

    In this article, we propose a new method for providing assistance during cyclical movements. This method is trajectory-free, in the sense that it provides user assistance irrespective of the performed movement, and requires no other sensing than the assisting robot's own encoders. The approach is based on adaptive oscillators, i.e., mathematical tools that are capable of learning the high level features (frequency, envelope, etc.) of a periodic input signal. Here we present two experiments that we recently conducted to validate our approach: a simple sinusoidal movement of the elbow, that we designed as a proof-of-concept, and a walking experiment. In both cases, we collected evidence illustrating that our approach indeed assisted healthy subjects during movement execution. Owing to the intrinsic periodicity of daily life movements involving the lower-limbs, we postulate that our approach holds promise for the design of innovative rehabilitation and assistance protocols for the lower-limb, requiring little to no user-specific calibration.

  14. Seasonal Climate Variation and Caribou Availability: Modeling Sequential Movement Using Satellite-Relocation Data

    Directory of Open Access Journals (Sweden)

    Craig Nicolson

    2013-06-01

    Full Text Available Livelihood systems that depend on mobile resources must constantly adapt to change. For people living in permanent settlements, environmental changes that affect the distribution of a migratory species may reduce the availability of a primary food source, with the potential to destabilize the regional social-ecological system. Food security for Arctic indigenous peoples harvesting barren ground caribou (Rangifer tarandus granti depends on movement patterns of migratory herds. Quantitative assessments of physical, ecological, and social effects on caribou distribution have proven difficult because of the significant interannual variability in seasonal caribou movement patterns. We developed and evaluated a modeling approach for simulating the distribution of a migratory herd throughout its annual cycle over a multiyear period. Beginning with spatial and temporal scales developed in previous studies of the Porcupine Caribou Herd of Canada and Alaska, we used satellite collar locations to compute and analyze season-by-season probabilities of movement of animals between habitat zones under two alternative weather conditions for each season. We then built a set of transition matrices from these movement probabilities, and simulated the sequence of movements across the landscape as a Markov process driven by externally imposed seasonal weather states. Statistical tests showed that the predicted distributions of caribou were consistent with observed distributions, and significantly correlated with subsistence harvest levels for three user communities. Our approach could be applied to other caribou herds and could be adapted for simulating the distribution of other ungulates and species with similarly large interannual variability in the use of their range.

  15. DEVELOPMENT OF SMALL-SCALE CONSTRUCTION ENTERPRISE PROCESS MANAGEMENT MODEL

    OpenAIRE

    E. V. Folomeev

    2012-01-01

    Process approach is one of most effective ways of managing construction companies. Resulting from using models based on this approach, the company’s structure becomes flexible enough to quickly acquire the ability to get functionally and structurally tuned for specific projects. It is demonstrated in this article how to develop a process management model mechanism for a small-scale construction company.

  16. Numerical calculation of path integrals : The small-polaron model

    NARCIS (Netherlands)

    Raedt, Hans De; Lagendijk, Ad

    1983-01-01

    The thermodynamic properties of the small-polaron model are studied by means of a discrete version of the Feynman path-integral representation of the partition function. This lattice model describes a fermion interacting with a boson field. The bosons are treated analytically, the fermion

  17. Modeling the Movement of Homicide by Type to Inform Public Health Prevention Efforts.

    Science.gov (United States)

    Zeoli, April M; Grady, Sue; Pizarro, Jesenia M; Melde, Chris

    2015-10-01

    We modeled the spatiotemporal movement of hotspot clusters of homicide by motive in Newark, New Jersey, to investigate whether different homicide types have different patterns of clustering and movement. We obtained homicide data from the Newark Police Department Homicide Unit's investigative files from 1997 through 2007 (n = 560). We geocoded the address at which each homicide victim was found and recorded the date of and the motive for the homicide. We used cluster detection software to model the spatiotemporal movement of statistically significant homicide clusters by motive, using census tract and month of occurrence as the spatial and temporal units of analysis. Gang-motivated homicides showed evidence of clustering and diffusion through Newark. Additionally, gang-motivated homicide clusters overlapped to a degree with revenge and drug-motivated homicide clusters. Escalating dispute and nonintimate familial homicides clustered; however, there was no evidence of diffusion. Intimate partner and robbery homicides did not cluster. By tracking how homicide types diffuse through communities and determining which places have ongoing or emerging homicide problems by type, we can better inform the deployment of prevention and intervention efforts.

  18. Empirical spatial econometric modelling of small scale neighbourhood

    Science.gov (United States)

    Gerkman, Linda

    2012-07-01

    The aim of the paper is to model small scale neighbourhood in a house price model by implementing the newest methodology in spatial econometrics. A common problem when modelling house prices is that in practice it is seldom possible to obtain all the desired variables. Especially variables capturing the small scale neighbourhood conditions are hard to find. If there are important explanatory variables missing from the model, the omitted variables are spatially autocorrelated and they are correlated with the explanatory variables included in the model, it can be shown that a spatial Durbin model is motivated. In the empirical application on new house price data from Helsinki in Finland, we find the motivation for a spatial Durbin model, we estimate the model and interpret the estimates for the summary measures of impacts. By the analysis we show that the model structure makes it possible to model and find small scale neighbourhood effects, when we know that they exist, but we are lacking proper variables to measure them.

  19. 3E model for a small HEPP design

    International Nuclear Information System (INIS)

    Tesnjak, S.; Krznaric, M.; Buinac, R.; Lipovaca, N.

    2012-01-01

    Small HEPPs in every electric power system are classified as renewable energy sources. The 3E model works out fundamental power characteristics of small HEPPs, analyzes their impact on the environment and explains the financial analysis of costs, revenues, and economic methods of evaluating the project. The advantages of small HEPPs include low distribution costs, no negative impact on the environment unlike large HEPPs, and lower maintenance costs. All the above benefits depend on the proper choice of the power plant equipment, object design, as well as advantages and disadvantages in every particular situation. (Authors)

  20. A computational model of human-robot load sharing during robot-assisted arm movement training after stroke.

    Science.gov (United States)

    Reinkensmeyer, David J; Wolbrecht, Eric; Bobrow, James

    2007-01-01

    An important goal in robot-assisted movement therapy after neurologic injury is to provide an optimal amount of mechanical assistance to patients as they complete motor tasks. This paper presents a computational model of how humans interact with robotic therapy devices for the task of lifting a load to a desired height. The model predicts that an adaptive robotic therapy device will take over performance of the lifting task if the human motor control system contains a slacking term (i.e. a term that tries to the reduce force output of the arm when error is small) but the robot does not. We present experimental data from people with a chronic stroke as they train with a robotic arm orthosis that confirms this prediction. We also show that incorporating a slacking term into the robot overcomes this problem, increasing load sharing by the patient while still keeping kinematic errors small. These results provide insight into the computational mechanisms of human motor adaptation during rehabilitation therapy, and provide a framework for optimizing robot-assisted therapy.

  1. Specific-activity and concentration model applied to cesium movement in an oligotrophic lake

    International Nuclear Information System (INIS)

    Vanderploeg, H.A.; Booth, R.S.; Clark, F.H.

    1975-01-01

    A linear systems-analysis model was derived to simulate the time-dependent dynamics of specific activity and concentration of radionuclides in aquatic systems. Transfer coefficients were determined for movement of 137 Cs in the components of an oligotrophic lake. These coefficients were defined in terms of basic environmental and ecological data so that the model can be applied to a wide variety of sites. Simulations with a model that ignored sediment--water interactions predicted much higher 137 Cs specific activities in the lake water and biota than did those with the complete model. Comparing 137 Cs concentrations predicted by the model with concentrations reported for the biota of an experimentally contaminated oligotrophic lake indicated that the transfer coefficients derived for the biota are adequate

  2. Stereotactic body radiotherapy for stage I lung cancer and small lung metastasis: evaluation of an immobilization system for suppression of respiratory tumor movement and preliminary results

    Directory of Open Access Journals (Sweden)

    Ayakawa Shiho

    2009-05-01

    Full Text Available Abstract Background In stereotactic body radiotherapy (SBRT for lung tumors, reducing tumor movement is necessary. In this study, we evaluated changes in tumor movement and percutaneous oxygen saturation (SpO2 levels, and preliminary clinical results of SBRT using the BodyFIX immobilization system. Methods Between 2004 and 2006, 53 consecutive patients were treated for 55 lesions; 42 were stage I non-small cell lung cancer (NSCLC, 10 were metastatic lung cancers, and 3 were local recurrences of NSCLC. Tumor movement was measured with fluoroscopy under breath holding, free breathing on a couch, and free breathing in the BodyFIX system. SpO2 levels were measured with a finger pulseoximeter under each condition. The delivered dose was 44, 48 or 52 Gy, depending on tumor diameter, in 4 fractions over 10 or 11 days. Results By using the BodyFIX system, respiratory tumor movements were significantly reduced compared with the free-breathing condition in both craniocaudal and lateral directions, although the amplitude of reduction in the craniocaudal direction was 3 mm or more in only 27% of the patients. The average SpO2 did not decrease by using the system. At 3 years, the local control rate was 80% for all lesions. Overall survival was 76%, cause-specific survival was 92%, and local progression-free survival was 76% at 3 years in primary NSCLC patients. Grade 2 radiation pneumonitis developed in 7 patients. Conclusion Respiratory tumor movement was modestly suppressed by the BodyFIX system, while the SpO2 level did not decrease. It was considered a simple and effective method for SBRT of lung tumors. Preliminary results were encouraging.

  3. Design and Modelling of Small Scale Low Temperature Power Cycles

    DEFF Research Database (Denmark)

    Wronski, Jorrit

    he work presented in this report contributes to the state of the art within design and modelling of small scale low temperature power cycles. The study is divided into three main parts: (i) fluid property evaluation, (ii) expansion device investigations and (iii) heat exchanger performance...... times and below 10−7 away from the phase boundaries.Regarding expansion devices for small scale organic Rankine cycle (ORC) systems,this work focussed on reciprocating machines. A prototype of a reciprocating expander with a swept volume of 736 cm3 was tested and modelled. he model was written in object......-oriented Modelica code and was included in the thermo Cycle framework for small scale ORC systems. Special attention was paid to the valve system and a control method for variable expansion ratios was introduced based on a cogeneration scenario. Admission control based on evaporator and condenser conditions...

  4. Organisational models in agriculture with special reference to small farmers

    Directory of Open Access Journals (Sweden)

    Zakić Nebojša

    2014-01-01

    Full Text Available Agricultural value chains can be understood as the systems of people, organizations and activities needed to create process and deliver agricultural products from producers to consumers. Over time and due to huge changes that have happened in the surroundings, agricultural value chains have become very integrated and complex. Small farmers can prosper by joining in modern higher-level agricultural value chains, but there are numerous obstacles, as well. The work presents the typology of organizational models for agricultural production that consists of the models organised by producers, agribusiness companies (processors, retail chains, and intermediaries, facilitators (governments, non-governmental organisations and completely integrated models, established by some big companies. None of these models provides ideal solutions from the perspective of small producers. However, they say that the institutions, such as cooperatives and small farmers' organisations, present important mechanisms for including small producers in modern value chains and realizing the cooperation with agribusiness companies and other important players. This is also important for decision-makers and governmental bodies that should create a suitable environment and provide support so that small farmers and their organisations can integrate in modern value chains in a successful way.

  5. Elucidating the significance of spatial memory on movement decisions by African savannah elephants using state–space models

    Science.gov (United States)

    Polansky, Leo; Kilian, Werner; Wittemyer, George

    2015-01-01

    Spatial memory facilitates resource acquisition where resources are patchy, but how it influences movement behaviour of wide-ranging species remains to be resolved. We examined African elephant spatial memory reflected in movement decisions regarding access to perennial waterholes. State–space models of movement data revealed a rapid, highly directional movement behaviour almost exclusively associated with visiting perennial water. Behavioural change point (BCP) analyses demonstrated that these goal-oriented movements were initiated on average 4.59 km, and up to 49.97 km, from the visited waterhole, with the closest waterhole accessed 90% of the time. Distances of decision points increased when switching to different waterholes, during the dry season, or for female groups relative to males, while selection of the closest waterhole decreased when switching. Overall, our analyses indicated detailed spatial knowledge over large scales, enabling elephants to minimize travel distance through highly directional movement when accessing water. We discuss the likely cognitive and socioecological mechanisms driving these spatially precise movements that are most consistent with our findings. By applying modern analytic techniques to high-resolution movement data, this study illustrates emerging approaches for studying how cognition structures animal movement behaviour in different ecological and social contexts. PMID:25808888

  6. Elucidating the significance of spatial memory on movement decisions by African savannah elephants using state-space models.

    Science.gov (United States)

    Polansky, Leo; Kilian, Werner; Wittemyer, George

    2015-04-22

    Spatial memory facilitates resource acquisition where resources are patchy, but how it influences movement behaviour of wide-ranging species remains to be resolved. We examined African elephant spatial memory reflected in movement decisions regarding access to perennial waterholes. State-space models of movement data revealed a rapid, highly directional movement behaviour almost exclusively associated with visiting perennial water. Behavioural change point (BCP) analyses demonstrated that these goal-oriented movements were initiated on average 4.59 km, and up to 49.97 km, from the visited waterhole, with the closest waterhole accessed 90% of the time. Distances of decision points increased when switching to different waterholes, during the dry season, or for female groups relative to males, while selection of the closest waterhole decreased when switching. Overall, our analyses indicated detailed spatial knowledge over large scales, enabling elephants to minimize travel distance through highly directional movement when accessing water. We discuss the likely cognitive and socioecological mechanisms driving these spatially precise movements that are most consistent with our findings. By applying modern analytic techniques to high-resolution movement data, this study illustrates emerging approaches for studying how cognition structures animal movement behaviour in different ecological and social contexts. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  7. Scheduling of high-speed rail traffic based on discrete-time movement model

    International Nuclear Information System (INIS)

    Sun Ya-Hua; Cao Cheng-Xuan; Xu Yan; Wu Chao

    2013-01-01

    In this paper, a new simulation approach for solving the mixed train scheduling problem on the high-speed double-track rail line is presented. Based on the discrete-time movement model, we propose control strategies for mixed train movement with different speeds on a high-speed double-track rail line, including braking strategy, priority rule, travelling strategy, and departing rule. A new detailed algorithm is also presented based on the proposed control strategies for mixed train movement. Moreover, we analyze the dynamic properties of rail traffic flow on a high-speed rail line. Using our proposed method, we can effectively simulate the mixed train schedule on a rail line. The numerical results demonstrate that an appropriate decrease of the departure interval can enhance the capacity, and a suitable increase of the distance between two adjacent stations can enhance the average speed. Meanwhile, the capacity and the average speed will be increased by appropriately enhancing the ratio of faster train number to slower train number from 1. (general)

  8. Development of biological movement recognition by interaction between active basis model and fuzzy optical flow division.

    Science.gov (United States)

    Yousefi, Bardia; Loo, Chu Kiong

    2014-01-01

    Following the study on computational neuroscience through functional magnetic resonance imaging claimed that human action recognition in the brain of mammalian pursues two separated streams, that is, dorsal and ventral streams. It follows up by two pathways in the bioinspired model, which are specialized for motion and form information analysis (Giese and Poggio 2003). Active basis model is used to form information which is different from orientations and scales of Gabor wavelets to form a dictionary regarding object recognition (human). Also biologically movement optic-flow patterns utilized. As motion information guides share sketch algorithm in form pathway for adjustment plus it helps to prevent wrong recognition. A synergetic neural network is utilized to generate prototype templates, representing general characteristic form of every class. Having predefined templates, classifying performs based on multitemplate matching. As every human action has one action prototype, there are some overlapping and consistency among these templates. Using fuzzy optical flow division scoring can prevent motivation for misrecognition. We successfully apply proposed model on the human action video obtained from KTH human action database. Proposed approach follows the interaction between dorsal and ventral processing streams in the original model of the biological movement recognition. The attained results indicate promising outcome and improvement in robustness using proposed approach.

  9. LoMAPAM--Logical Model of Autowave Processes of Amoebic Movement.

    Science.gov (United States)

    Haverlík, Ivan K R; Výrasteková, Jana

    2002-07-01

    This work describes a logical discrete model of the spatiotemporal dynamics of amoebic movement (Logical Model of Autowave Processes of Amoebic Movement (LoMAPAM)) based on finite automata (homogeneous structures) and specified for Physarum polycephalum. The basic system of passing rules for the information and regulation levels of the model, describing the contractile behavior of the ectoplasmic walls of P. polycephalum, enables a rhythmic generation of contractile waves and their propagation in the ectoplasmic wall due to the created structure of the LoMAPAM model. The finite automata corresponds to elementary square planar elements. This construction is alike homogeneous structures with the only exception is its finite. The planar element is assigned to the pair of integers (i,j). The state vector defined for every element (i,j) in discrete time t will have three components. Each of them will be written in one of the matrices B, C, or W. The information matrix B describes the state of the matter. The regulation matrix C, the local Ca(2+) concentration. The flow matrix W describes the local flow of endoplasm or ectoplasm. The passing rules for the state vector was written in the form of Boolean functions. Six actomyosin generators placed on a circle and three and five neighbouring ectoplasmatic generators on a line and a layer of endoplasm were analysed.

  10. Model simulation studies to clarify the effect on saccadic eye movements of initial condition velocities set by the Vestibular Ocular Reflex (VOR)

    Science.gov (United States)

    Nam, M. H.; Winters, J. M.; Stark, L.

    1981-01-01

    Voluntary active head rotations produced vestibulo-ocular reflex eye movements (VOR) with the subject viewing a fixation target. When this target jumped, the size of the refixation saccades were a function of the ongoing initial velocity of the eye. Saccades made against the VOR were larger in magnitude. Simulation of a reciprocally innervated model eye movement provided results comparable to the experimental data. Most of the experimental effect appeared to be due to linear summation for saccades of 5 and 10 degree magnitude. For small saccades of 2.5 degrees, peripheral nonlinear interaction of state variables in the neuromuscular plant also played a role as proven by comparable behavior in the simulated model with known controller signals.

  11. Integrative modelling of animal movement: incorporating in situ habitat and behavioural information for a migratory marine predator.

    Science.gov (United States)

    Bestley, Sophie; Jonsen, Ian D; Hindell, Mark A; Guinet, Christophe; Charrassin, Jean-Benoît

    2013-01-07

    A fundamental goal in animal ecology is to quantify how environmental (and other) factors influence individual movement, as this is key to understanding responsiveness of populations to future change. However, quantitative interpretation of individual-based telemetry data is hampered by the complexity of, and error within, these multi-dimensional data. Here, we present an integrative hierarchical Bayesian state-space modelling approach where, for the first time, the mechanistic process model for the movement state of animals directly incorporates both environmental and other behavioural information, and observation and process model parameters are estimated within a single model. When applied to a migratory marine predator, the southern elephant seal (Mirounga leonina), we find the switch from directed to resident movement state was associated with colder water temperatures, relatively short dive bottom time and rapid descent rates. The approach presented here can have widespread utility for quantifying movement-behaviour (diving or other)-environment relationships across species and systems.

  12. Finite Elements Modeling in Diagnostics of Small Closed Pneumothorax.

    Science.gov (United States)

    Lorkowski, J; Mrzygłód, M; Grzegorowska, O

    2015-01-01

    Posttraumatic pneumothorax still remains to be a serious clinical problem and requires a comprehensive diagnostic and monitoring during treatment. The aim of this paper is to present a computer method of modeling of small closed pneumothorax. Radiological images of 34 patients of both sexes with small closed pneumothorax were taken into consideration. The control group consisted of X-rays of 22 patients treated because of tension pneumothorax. In every single case the model was correlated with the clinical manifestations. The procedure of computational rapid analysis (CRA) for in silico analysis of surgical intervention was introduced. It included implementation of computerize tomography images and their automatic conversion into 3D finite elements model (FEM). In order to segmentize the 3D model, an intelligent procedure of domain recognition was used. In the final step, a computer simulation project of fluid-structure interaction was built, using the ANSYS\\Workbench environment of multi-physics analysis. The FEM model and computer simulation project were employed in the analysis in order to optimize surgical intervention. The model worked out well and was compatible with the clinical manifestations of pneumothorax. We conclude that the created FEM model is a promising tool for facilitation of diagnostic procedures and prognosis of treatment in the case of small closed pneumothorax.

  13. PROPOSAL OF A MODEL MANAGEMENT TO SMALL DESIGN COMPANIES

    Directory of Open Access Journals (Sweden)

    Otávio José de OLIVEIRA

    2008-11-01

    Full Text Available The main purpose of this paper is the proposition of a management model specifically developed for small building design firms, aligned with their needs and particularities. The field research was conducted with a qualitative approach through the analysis of four case studies in small building design firms acting mainly in São Paulo City. The data collection was accomplished through semi-structured interviews, direct observation and analysis of documents. The proposed model includes guidance to the management of the core processes and activities of small building design firms, such as: organizational structure; strategic planning; planning and control of design process; costs management; sales management; information systems; human resources management; services added to the design; and performance evaluation. Key-words: design firms; design process; building construction.

  14. Use of ionic model for analysis of intramolecular movement in alkali metal metaborate molecules

    International Nuclear Information System (INIS)

    Ezhov, Yu.S.; Vinogradov, V.S.

    1978-01-01

    To clear out the peculiarities of intramolecular movement in MBO 2 (where M=Li, Na, K, Rb, Cs) molecules the energy dependence of cation electrostatic interaction with BO 2 anion on the charge value of oxygen, values of the MOB valence angle and internuclear distance r(M-O) is calculated. The calculation results on the base of ionic model show that the minimum of potential energy function corresponds to angular configuration of the MBO 2 molecules. Parameters of potential function of deformation oscillation connected with the change of MOB angle, are evaluated

  15. Continuous Dependence in Front Propagation for Convective Reaction-Diffusion Models with Aggregative Movements

    Directory of Open Access Journals (Sweden)

    Luisa Malaguti

    2011-01-01

    Full Text Available The paper deals with a degenerate reaction-diffusion equation, including aggregative movements and convective terms. The model also incorporates a real parameter causing the change from a purely diffusive to a diffusive-aggregative and to a purely aggregative regime. Existence and qualitative properties of traveling wave solutions are investigated, and estimates of their threshold speeds are furnished. Further, the continuous dependence of the threshold wave speed and of the wave profiles on a real parameter is studied, both when the process maintains its diffusion-aggregation nature and when it switches from it to another regime.

  16. A MATHEMATICAL MODEL OF THE MILITARY TRANSPORT AIRCRAFT MOVEMENT AT CARGO ITEM DROP

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The controllability of military transport aircraft deteriorates at heavy single piece landing. To solve this problem and a specific methodology for pilotage of the pre-emption, and automation tools are being developed. Preliminary study ofpilotage technique and authomatic control algorythm demand a reliable mathematical model of aircraft dynamics at cargo item drop. Such model should take into account significant change in the position of the aircraft center of mass and aircraft inertia tensor. Simplified models were based on modeling the movement of the center of mass and rotation around the cen- ter of mass of the aircraft. Such models do not take into account the inertial forces and moments of moving a cargo item. This circumstance does not allow to obtain reliable results in the simulation. The article presents the description of the complete mathematical model of the movement of military transport aircraft in landing of a cargo item. Examines the com- plex material system of solids and a detailed description of the properties of its components. The equations of motion of the aircraft as a system carrier (aircraft without a cargo item and wear (of moving a cargo item bodies to reflect the changes in the inertia tensor. The functioning of the power plant, steering actuators, flight control system, an exhaust chute, the sen- sors of the primary information are taken into account. The equations of motion for systems of bodies projected on the air- craft reference plane are being recorded. This approach takes into account changes of the inertia tensor and the position of the main central axes of inertia in the process of landing of a cargo item. It allows us to simulate the condition of the air- craft at all speeds of the pitch, normal overload, and masses of single piece and placement, as evidenced by the high con- vergence of modeling results with data from flight tests.

  17. On the small-time behavior of stochastic logistic models

    Directory of Open Access Journals (Sweden)

    Dung Tien Nguyen

    2017-09-01

    Full Text Available In this paper we investigate the small-time behaviors of the solution to  a stochastic logistic model. The obtained results allow us to estimate the number of individuals in the population and can be used to study stochastic prey-predator systems.

  18. Waste Reduction Model (WARM) Resources for Small Businesses and Organizations

    Science.gov (United States)

    This page provides a brief overview of how EPA’s Waste Reduction Model (WARM) can be used by small businesses and organizations. The page includes a brief summary of uses of WARM for the audience and links to other resources.

  19. Small-Scale Helicopter Automatic Autorotation : Modeling, Guidance, and Control

    NARCIS (Netherlands)

    Taamallah, S.

    2015-01-01

    Our research objective consists in developing a, model-based, automatic safety recovery system, for a small-scale helicopter Unmanned Aerial Vehicle (UAV) in autorotation, i.e. an engine OFF flight condition, that safely flies and lands the helicopter to a pre-specified ground location. In pursuit

  20. The Academic Knowledge Management Model of Small Schools in Thailand

    Science.gov (United States)

    Tumtuma, Chamnan; Chantarasombat, Chalard; Yeamsang, Theerawat

    2015-01-01

    The Academic Knowledge Management Model of Small Schools in Thailand was created by research and development. The quantitative and qualitative data were collected via the following steps: a participatory workshop meeting, the formation of a team according to knowledge base, field study, brainstorming, group discussion, activities carried out…

  1. 3D Dynamic Modeling of the Head-Neck Complex for Fast Eye and Head Orientation Movements Research

    Directory of Open Access Journals (Sweden)

    Daniel A. Sierra

    2011-01-01

    Full Text Available A 3D dynamic computer model for the movement of the head-neck complex is presented. It incorporates anatomically correct information about the diverse elements forming the system. The skeleton is considered as a set of interconnected rigid 3D bodies following the Newton-Euler laws of movement. The muscles are modeled using Enderle's linear model, which shows equivalent dynamic characteristics to Loeb's virtual muscle model. The soft tissues, namely, the ligaments, intervertebral disks, and facet joints, are modeled considering their physiological roles and dynamics. In contrast with other head and neck models developed for safety research, the model is aimed to study the neural control of the complex during fast eye and head movements, such as saccades and gaze shifts. In particular, the time-optimal hypothesis and the feedback control ones are discussed.

  2. Evaluation Model of Organizational Performance for Small and Medium Enterprises

    Directory of Open Access Journals (Sweden)

    Carlos Augusto Passos

    2014-12-01

    Full Text Available In the 1980’s, many tools for evaluating organizational performance were created. However, most of them are useful only to large companies and do not foster results in small and medium-sized enterprises (SMEs. In light of this fact, this article aims at proposing an Organizational Performance Assessment model (OPA which is flexible and adaptable to the reality of SMEs, based on the theoretical framework of various models, and comparisons on the basis of three major authors’ criteria to evaluate OPA models. The research has descriptive and exploratory character, with qualitative nature. The MADE-O model, according to the criteria described in the bibliography, is the one that best fits the needs of SMEs, used as a baseline for the model proposed in this study with adaptations pertaining to the BSC model. The model called the Overall Performance Indicator – Environment (IDG-E has as its main differential, in addition to the base of the models mentioned above, the assessment of the external and internal environment weighted in modules of OPA. As the SME is characterized by having few processes and people, the small amount of performance indicators is another positive aspect. Submitted to the evaluation of the criteria subscribed by the authors, the model proved to be quite feasible for use in SMEs.

  3. The importance of examining movements within the US health care system: sequential logit modeling

    Directory of Open Access Journals (Sweden)

    Lee Chioun

    2010-09-01

    Full Text Available Abstract Background Utilization of specialty care may not be a discrete, isolated behavior but rather, a behavior of sequential movements within the health care system. Although patients may often visit their primary care physician and receive a referral before utilizing specialty care, prior studies have underestimated the importance of accounting for these sequential movements. Methods The sample included 6,772 adults aged 18 years and older who participated in the 2001 Survey on Disparities in Quality of Care, sponsored by the Commonwealth Fund. A sequential logit model was used to account for movement in all stages of utilization: use of any health services (i.e., first stage, having a perceived need for specialty care (i.e., second stage, and utilization of specialty care (i.e., third stage. In the sequential logit model, all stages are nested within the previous stage. Results Gender, race/ethnicity, education and poor health had significant explanatory effects with regard to use of any health services and having a perceived need for specialty care, however racial/ethnic, gender, and educational disparities were not present in utilization of specialty care. After controlling for use of any health services and having a perceived need for specialty care, inability to pay for specialty care via income (AOR = 1.334, CI = 1.10 to 1.62 or health insurance (unstable insurance: AOR = 0.26, CI = 0.14 to 0.48; no insurance: AOR = 0.12, CI = 0.07 to 0.20 were significant barriers to utilization of specialty care. Conclusions Use of a sequential logit model to examine utilization of specialty care resulted in a detailed representation of utilization behaviors and patient characteristics that impact these behaviors at all stages within the health care system. After controlling for sequential movements within the health care system, the biggest barrier to utilizing specialty care is the inability to pay, while racial, gender, and educational disparities

  4. A GEO-VISUAL ANALYTICS APPROACH TO BIOLOGICAL SHEPHERDING: MODELLING ANIMAL MOVEMENTS AND IMPACTS

    Directory of Open Access Journals (Sweden)

    K. K. Benke

    2012-07-01

    Full Text Available The lamb industry in Victoria is a significant component of the state economy with annual exports in the vicinity of $1 billion. GPS and visualisation tools can be used to monitor grazing animal movements at the farm scale and observe interactions with the environment. Modelling the spatial-temporal movements of grazing animals in response to environmental conditions provides input for the design of paddocks with the aim of improving management procedures, animal performance and animal welfare. The term "biological shepherding" is associated with the re-design of environmental conditions and the analysis of responses from grazing animals. The combination of biological shepherding with geo-visual analytics (geo-spatial data analysis with visualisation provides a framework for improving landscape design and supports research in grazing behaviour in variable landscapes, heat stress avoidance behaviour during summer months, and modelling excreta distributions (with respect to nitrogen emissions and nitrogen return for fertilising the paddock. Nitrogen losses due to excreta are mainly in the form of gaseous emissions to the atmosphere and leaching into the groundwater. In this study, background and context are provided in the case of biological shepherding and tracking animal movements. Examples are provided of recent applications in regional Australia and New Zealand. Based on experimental data and computer simulation, and using data visualisation and feature extraction, it was demonstrated that livestock excreta are not always randomly located, but concentrated around localised gathering points, sometimes separated by the nature of the excretion. Farmers require information on the nitrogen losses in order to reduce emissions to meet local and international nitrogen leaching and greenhouse gas targets and to improve the efficiency of nutrient management.

  5. Hydrodynamic modelling of small upland lakes under strong wind forcing

    Science.gov (United States)

    Morales, L.; French, J.; Burningham, H.

    2012-04-01

    Small lakes (Area important source of water supply. Lakes also provide an important sedimentary archive of environmental and climate changes and ecosystem function. Hydrodynamic controls on the transport and distribution of lake sediments, and also seasonal variations in thermal structure due to solar radiation, precipitation, evaporation and mixing and the complex vertical and horizontal circulation patterns induced by the action of wind are not very well understood. The work presented here analyses hydrodynamic motions present in small upland lakes due to circulation and internal scale waves, and their linkages with the distribution of bottom sediment accumulation in the lake. For purpose, a 3D hydrodynamic is calibrated and implemented for Llyn Conwy, a small oligotrophic upland lake in North Wales, UK. The model, based around the FVCOM open source community model code, resolves the Navier-Stokes equations using a 3D unstructured mesh and a finite volume scheme. The model is forced by meteorological boundary conditions. Improvements made to the FVCOM code include a new graphical user interface to pre- and post process the model input and results respectively, and a JONSWAT wave model to include the effects of wind-wave induced bottom stresses on lake sediment dynamics. Modelled internal scale waves are validated against summer temperature measurements acquired from a thermistor chain deployed at the deepest part of the lake. Seiche motions were validated using data recorded by high-frequency level sensors around the lake margins, and the velocity field and the circulation patterns were validated using the data recorded by an ADCP and GPS drifters. The model is shown to reproduce the lake hydrodynamics and reveals well-developed seiches at different frequencies superimposed on wind-driven circulation patterns that appear to control the distribution of bottom sediments in this small upland lake.

  6. Evaluation of simplified analytical models for CO2 plume movement and pressure buildup

    Science.gov (United States)

    Oruganti, Y.; Mishra, S.

    2011-12-01

    CO2 injection into the sub-surface is emerging as a viable technology for reducing anthropogenic CO2 emissions into the atmosphere. When large amounts of CO2 are sequestered, pressure buildup is an associated risk, along with plume movement beyond the injected domain. In this context, simple modeling tools become valuable assets in preliminary CO2 injection project screening and implementation phases. This study presents an evaluation of two commonly used simplified analytical models for plume movement and pressure buildup, (1) the sharp interface model of Nordbotten et al. (2005), and the corresponding pressure distribution solution of Mathias et al. (2008), and (2) the 3-region model of Burton et al. (2008) based on fractional flow and steady-state pressure gradient considerations. The three-region model of Burton et al. assumes a constant pressure outer boundary. In this study, we incorporate the radius of investigation of the pressure front as the transient pressure boundary, in order to represent an infinite-acting system. The sharp-interface model also assumes the system to be infinite-acting. Temperature and pressure conditions used in these models correspond to the "warm, shallow" and "cold, deep" aquifer conditions as defined by Nordbotten et al. The saturation and pressure profiles as well as injection-well pressure buildup predicted by the analytical models are compared with those from the numerical simulator STOMP in order to provide a verification of the simplified modeling assumptions. Both the STOMP results and the three-region model show two sharp fronts (the drying and two-phase fronts), and a good match is obtained between the front positions at any time. For the sharp interface model, the vertically averaged gas saturation does not exhibit two sharp fronts as seen in the STOMP simulations, but shows a gradual change in saturation with radial distance over the two-phase region. The pressure profiles from STOMP and the analytical model are

  7. Modeling Small Noncanonical RNA Motifs with the Rosetta FARFAR Server.

    Science.gov (United States)

    Yesselman, Joseph D; Das, Rhiju

    2016-01-01

    Noncanonical RNA motifs help define the vast complexity of RNA structure and function, and in many cases, these loops and junctions are on the order of only ten nucleotides in size. Unfortunately, despite their small size, there is no reliable method to determine the ensemble of lowest energy structures of junctions and loops at atomic accuracy. This chapter outlines straightforward protocols using a webserver for Rosetta Fragment Assembly of RNA with Full Atom Refinement (FARFAR) ( http://rosie.rosettacommons.org/rna_denovo/submit ) to model the 3D structure of small noncanonical RNA motifs for use in visualizing motifs and for further refinement or filtering with experimental data such as NMR chemical shifts.

  8. Voussoir beam model for lower strong roof strata movement in longwall mining – Case study

    Directory of Open Access Journals (Sweden)

    Chuang Liu

    2017-12-01

    Full Text Available The paper presents the influence of varying immediate roof thickness on the lower strong roof strata movement and failure pattern in longwall coal mining with large mining height. The investigation is based on 58 geological drill holes and hydraulic shield pressure measurements around the longwall Panel 42105 of the Buertai Mine in Inner Mongolia Autonomous Region, China. The longwall Panel 42105 is characterized by relatively soft immediate roof strata of varying thickness superposed by strong strata, herein defined as lower strong roof. A voussoir beam model is adopted to interpret the structural movement of the lower strong roof strata and shield pressure measurements. It is shown that when the immediate roof is relatively thick, the broken overlying lower strong roof tends to form a stable voussoir beam with previously broken layer, thus not exerting high pressure on the hydraulic shield and working face. When the immediate roof is relatively thin, the broken overlying lower strong roof tends to behave as a cantilever beam, thus exerting higher pressure on the hydraulic shield and working face. Comparison of model predictions with measured time-weighted average shield pressure (TWAP shows good agreement.

  9. Ab initio modeling of small proteins by iterative TASSER simulations

    Directory of Open Access Journals (Sweden)

    Zhang Yang

    2007-05-01

    Full Text Available Abstract Background Predicting 3-dimensional protein structures from amino-acid sequences is an important unsolved problem in computational structural biology. The problem becomes relatively easier if close homologous proteins have been solved, as high-resolution models can be built by aligning target sequences to the solved homologous structures. However, for sequences without similar folds in the Protein Data Bank (PDB library, the models have to be predicted from scratch. Progress in the ab initio structure modeling is slow. The aim of this study was to extend the TASSER (threading/assembly/refinement method for the ab initio modeling and examine systemically its ability to fold small single-domain proteins. Results We developed I-TASSER by iteratively implementing the TASSER method, which is used in the folding test of three benchmarks of small proteins. First, data on 16 small proteins (α-root mean square deviation (RMSD of 3.8Å, with 6 of them having a Cα-RMSD α-RMSD α-RMSD of the I-TASSER models was 3.9Å, whereas it was 5.9Å using TOUCHSTONE-II software. Finally, 20 non-homologous small proteins (α-RMSD of 3.9Å was obtained for the third benchmark, with seven cases having a Cα-RMSD Conclusion Our simulation results show that I-TASSER can consistently predict the correct folds and sometimes high-resolution models for small single-domain proteins. Compared with other ab initio modeling methods such as ROSETTA and TOUCHSTONE II, the average performance of I-TASSER is either much better or is similar within a lower computational time. These data, together with the significant performance of automated I-TASSER server (the Zhang-Server in the 'free modeling' section of the recent Critical Assessment of Structure Prediction (CASP7 experiment, demonstrate new progresses in automated ab initio model generation. The I-TASSER server is freely available for academic users http://zhang.bioinformatics.ku.edu/I-TASSER.

  10. Modeling and Parameter Estimation of a Small Wind Generation System

    Directory of Open Access Journals (Sweden)

    Carlos A. Ramírez Gómez

    2013-11-01

    Full Text Available The modeling and parameter estimation of a small wind generation system is presented in this paper. The system consists of a wind turbine, a permanent magnet synchronous generator, a three phase rectifier, and a direct current load. In order to estimate the parameters wind speed data are registered in a weather station located in the Fraternidad Campus at ITM. Wind speed data were applied to a reference model programed with PSIM software. From that simulation, variables were registered to estimate the parameters. The wind generation system model together with the estimated parameters is an excellent representation of the detailed model, but the estimated model offers a higher flexibility than the programed model in PSIM software.

  11. A holistic water depth simulation model for small ponds

    Science.gov (United States)

    Ali, Shakir; Ghosh, Narayan C.; Mishra, P. K.; Singh, R. K.

    2015-10-01

    Estimation of time varying water depth and time to empty of a pond is prerequisite for comprehensive and coordinated planning of water resource for its effective utilization. A holistic water depth simulation (HWDS) and time to empty (TE) model for small, shallow ephemeral ponds have been derived by employing the generalized model based on the Green-Ampt equation in the basic water balance equation. The HWDS model includes time varying rainfall, runoff, surface water evaporation, outflow and advancement of wetting front length as external inputs. The TE model includes two external inputs; surface water evaporation and advancement of wetting front length. Both the models also consider saturated hydraulic conductivity and fillable porosity of the pond's bed material as their parameters. The solution of the HWDS model involved numerical iteration in successive time intervals. The HWDS model has successfully evaluated with 3 years of field data from two small ponds located within a watershed in a semi-arid region in western India. The HWDS model simulated time varying water depth in the ponds with high accuracy as shown by correlation coefficient (R2 ⩾ 0.9765), index of agreement (d ⩾ 0.9878), root mean square errors (RMSE ⩽ 0.20 m) and percent bias (PB ⩽ 6.23%) for the pooled data sets of the measured and simulated water depth. The statistical F and t-tests also confirmed the reliability of the HWDS model at probability level, p ⩽ 0.0001. The response of the TE model showed its ability to estimate the time to empty the ponds. An additional field calibration and validation of the HWDS and TE models with observed field data in varied hydro-climatic conditions could be conducted to increase the applicability and credibility of the models.

  12. Modelling of agricultural combination driver behaviour from the aspect of safety of movement.

    Science.gov (United States)

    Szczepaniak, Jan; Tanaś, Wojciech; Pawłowski, Tadeusz; Kromulski, Jacek

    2014-01-01

    Statistics show that the travel of agricultural machinery to a work area and their movement during labour is the source of many serious accidents. The most dangerous in consequences prove to be those that occur during transport and associated with maneuvering tractors and machinery (about 30% of all fatal accidents). It can be assumed that at least some of these accidents were caused indirectly by the specific design features of agricultural machines which adversely affect the driveability. The single- and multi-loop structures of the driver-vehicle system models are formulated to study the contributions of various preview and prediction strategies to the path tracking and dynamic performance of the articulated vehicle. In the presented study the compensatory model of driver utilizes the lateral acceleration of the tractor, roll angle of trailer sprung mass and the articulation rate as the internal motion feedback variables. The control model of steering of an agricultural set has been implemented in the Matlab/Simulink environment. The model has been constructed with the use of stochastic methods and operational transmittances describing the various components of the system. The model operational transmittances has been estimated using Box-Jenkins and continuous-time process models from input-output data. The model has been tested using experimental data from road investigation of the agricultural set.

  13. Inflammatory responses in two commonly used rat models for experimental tooth movement: comparison with ligature-induced periodontitis

    NARCIS (Netherlands)

    Xie, R.; Kuijpers-Jagtman, A.M.; Maltha, J.C.

    2011-01-01

    OBJECTIVE: To compare two often used rat models for experimental tooth movement, namely the elastic band, and the coil spring model. They were compared with a silk-ligature-induced periodontitis model. DESIGN: Thirty six, 6-weeks-old rats were used. In a split mouth design four experimental

  14. A Model-Based Approach for the Measurement of Eye Movements Using Image Processing

    Science.gov (United States)

    Sung, Kwangjae; Reschke, Millard F.

    1997-01-01

    This paper describes a video eye-tracking algorithm which searches for the best fit of the pupil modeled as a circular disk. The algorithm is robust to common image artifacts such as the droopy eyelids and light reflections while maintaining the measurement resolution available by the centroid algorithm. The presented algorithm is used to derive the pupil size and center coordinates, and can be combined with iris-tracking techniques to measure ocular torsion. A comparison search method of pupil candidates using pixel coordinate reference lookup tables optimizes the processing requirements for a least square fit of the circular disk model. This paper includes quantitative analyses and simulation results for the resolution and the robustness of the algorithm. The algorithm presented in this paper provides a platform for a noninvasive, multidimensional eye measurement system which can be used for clinical and research applications requiring the precise recording of eye movements in three-dimensional space.

  15. Modelling of redox front and uranium movement in a uranium mine at Pocos de Caldas

    International Nuclear Information System (INIS)

    Cross, J.E.; Haworth, A.; Neretnieks, I.; Sharland, S.M.; Tweed, C.J.

    1991-01-01

    A study of the natural migration of uranium at the Pocos de Caldas uranium mine in Brazil under the influence of the movement of oxidizing groundwaters has been performed. This has involved use of the coupled chemical equilibria/transport code CHEQMATE. Preliminary results give some encouraging agreements with field data which gives confidence in the validity of using such modelling techniques in other problems associated with the migration of radionuclides away from a nuclear waste repository. For particular aspects of the problem where good agreement with field data was not obtained, a number of suggestions have been made. These include incorrect choice of solubility-limiting mineral phases in the model, mineral precipitation reactions not being at equilibrium and possible errors in field measurements due to contamination of deep groundwater samples by surface waters. (orig.)

  16. A small-world network model of facial emotion recognition.

    Science.gov (United States)

    Takehara, Takuma; Ochiai, Fumio; Suzuki, Naoto

    2016-01-01

    Various models have been proposed to increase understanding of the cognitive basis of facial emotions. Despite those efforts, interactions between facial emotions have received minimal attention. If collective behaviours relating to each facial emotion in the comprehensive cognitive system could be assumed, specific facial emotion relationship patterns might emerge. In this study, we demonstrate that the frameworks of complex networks can effectively capture those patterns. We generate 81 facial emotion images (6 prototypes and 75 morphs) and then ask participants to rate degrees of similarity in 3240 facial emotion pairs in a paired comparison task. A facial emotion network constructed on the basis of similarity clearly forms a small-world network, which features an extremely short average network distance and close connectivity. Further, even if two facial emotions have opposing valences, they are connected within only two steps. In addition, we show that intermediary morphs are crucial for maintaining full network integration, whereas prototypes are not at all important. These results suggest the existence of collective behaviours in the cognitive systems of facial emotions and also describe why people can efficiently recognize facial emotions in terms of information transmission and propagation. For comparison, we construct three simulated networks--one based on the categorical model, one based on the dimensional model, and one random network. The results reveal that small-world connectivity in facial emotion networks is apparently different from those networks, suggesting that a small-world network is the most suitable model for capturing the cognitive basis of facial emotions.

  17. Scaling and percolation in the small-world network model

    International Nuclear Information System (INIS)

    Newman, M. E. J.; Watts, D. J.

    1999-01-01

    In this paper we study the small-world network model of Watts and Strogatz, which mimics some aspects of the structure of networks of social interactions. We argue that there is one nontrivial length-scale in the model, analogous to the correlation length in other systems, which is well-defined in the limit of infinite system size and which diverges continuously as the randomness in the network tends to zero, giving a normal critical point in this limit. This length-scale governs the crossover from large- to small-world behavior in the model, as well as the number of vertices in a neighborhood of given radius on the network. We derive the value of the single critical exponent controlling behavior in the critical region and the finite size scaling form for the average vertex-vertex distance on the network, and, using series expansion and Pade approximants, find an approximate analytic form for the scaling function. We calculate the effective dimension of small-world graphs and show that this dimension varies as a function of the length-scale on which it is measured, in a manner reminiscent of multifractals. We also study the problem of site percolation on small-world networks as a simple model of disease propagation, and derive an approximate expression for the percolation probability at which a giant component of connected vertices first forms (in epidemiological terms, the point at which an epidemic occurs). The typical cluster radius satisfies the expected finite size scaling form with a cluster size exponent close to that for a random graph. All our analytic results are confirmed by extensive numerical simulations of the model. (c) 1999 The American Physical Society

  18. Electromagnetic fields in small systems from a multiphase transport model

    Science.gov (United States)

    Zhao, Xin-Li; Ma, Yu-Gang; Ma, Guo-Liang

    2018-02-01

    We calculate the electromagnetic fields generated in small systems by using a multiphase transport (AMPT) model. Compared to A +A collisions, we find that the absolute electric and magnetic fields are not small in p +Au and d +Au collisions at energies available at the BNL Relativistic Heavy Ion Collider and in p +Pb collisions at energies available at the CERN Large Hadron Collider. We study the centrality dependencies and the spatial distributions of electromagnetic fields. We further investigate the azimuthal fluctuations of the magnetic field and its correlation with the fluctuating geometry using event-by-event simulations. We find that the azimuthal correlation 〈" close="〉cos(ϕα+ϕβ-2 ΨRP)〉">cos2 (ΨB-Ψ2) between the magnetic field direction and the second-harmonic participant plane is almost zero in small systems with high multiplicities, but not in those with low multiplicities. This indicates that the charge azimuthal correlation is not a valid probe to study the chiral magnetic effect (CME) in small systems with high multiplicities. However, we suggest searching for possible CME effects in small systems with low multiplicities.

  19. Reinforcement learning of targeted movement in a spiking neuronal model of motor cortex.

    Science.gov (United States)

    Chadderdon, George L; Neymotin, Samuel A; Kerr, Cliff C; Lytton, William W

    2012-01-01

    Sensorimotor control has traditionally been considered from a control theory perspective, without relation to neurobiology. In contrast, here we utilized a spiking-neuron model of motor cortex and trained it to perform a simple movement task, which consisted of rotating a single-joint "forearm" to a target. Learning was based on a reinforcement mechanism analogous to that of the dopamine system. This provided a global reward or punishment signal in response to decreasing or increasing distance from hand to target, respectively. Output was partially driven by Poisson motor babbling, creating stochastic movements that could then be shaped by learning. The virtual forearm consisted of a single segment rotated around an elbow joint, controlled by flexor and extensor muscles. The model consisted of 144 excitatory and 64 inhibitory event-based neurons, each with AMPA, NMDA, and GABA synapses. Proprioceptive cell input to this model encoded the 2 muscle lengths. Plasticity was only enabled in feedforward connections between input and output excitatory units, using spike-timing-dependent eligibility traces for synaptic credit or blame assignment. Learning resulted from a global 3-valued signal: reward (+1), no learning (0), or punishment (-1), corresponding to phasic increases, lack of change, or phasic decreases of dopaminergic cell firing, respectively. Successful learning only occurred when both reward and punishment were enabled. In this case, 5 target angles were learned successfully within 180 s of simulation time, with a median error of 8 degrees. Motor babbling allowed exploratory learning, but decreased the stability of the learned behavior, since the hand continued moving after reaching the target. Our model demonstrated that a global reinforcement signal, coupled with eligibility traces for synaptic plasticity, can train a spiking sensorimotor network to perform goal-directed motor behavior.

  20. Reinforcement learning of targeted movement in a spiking neuronal model of motor cortex.

    Directory of Open Access Journals (Sweden)

    George L Chadderdon

    Full Text Available Sensorimotor control has traditionally been considered from a control theory perspective, without relation to neurobiology. In contrast, here we utilized a spiking-neuron model of motor cortex and trained it to perform a simple movement task, which consisted of rotating a single-joint "forearm" to a target. Learning was based on a reinforcement mechanism analogous to that of the dopamine system. This provided a global reward or punishment signal in response to decreasing or increasing distance from hand to target, respectively. Output was partially driven by Poisson motor babbling, creating stochastic movements that could then be shaped by learning. The virtual forearm consisted of a single segment rotated around an elbow joint, controlled by flexor and extensor muscles. The model consisted of 144 excitatory and 64 inhibitory event-based neurons, each with AMPA, NMDA, and GABA synapses. Proprioceptive cell input to this model encoded the 2 muscle lengths. Plasticity was only enabled in feedforward connections between input and output excitatory units, using spike-timing-dependent eligibility traces for synaptic credit or blame assignment. Learning resulted from a global 3-valued signal: reward (+1, no learning (0, or punishment (-1, corresponding to phasic increases, lack of change, or phasic decreases of dopaminergic cell firing, respectively. Successful learning only occurred when both reward and punishment were enabled. In this case, 5 target angles were learned successfully within 180 s of simulation time, with a median error of 8 degrees. Motor babbling allowed exploratory learning, but decreased the stability of the learned behavior, since the hand continued moving after reaching the target. Our model demonstrated that a global reinforcement signal, coupled with eligibility traces for synaptic plasticity, can train a spiking sensorimotor network to perform goal-directed motor behavior.

  1. On the origin of crossover interference: A chromosome oscillatory movement (COM model

    Directory of Open Access Journals (Sweden)

    Hultén Maj A

    2011-04-01

    Full Text Available Abstract Background It is now nearly a century since it was first discovered that crossovers between homologous parental chromosomes, originating at the Prophase stage of Meiosis I, are not randomly placed. In fact, the number and distribution of crossovers are strictly regulated with crossovers/chiasmata formed in optimal positions along the length of individual chromosomes, facilitating regular chromosome segregation at the first meiotic division. In spite of much research addressing this question, the underlying mechanism(s for the phenomenon called crossover/chiasma interference is/are still unknown; and this constitutes an outstanding biological enigma. Results The Chromosome Oscillatory Movement (COM model for crossover/chiasma interference implies that, during Prophase of Meiosis I, oscillatory movements of the telomeres (attached to the nuclear membrane and the kinetochores (within the centromeres create waves along the length of chromosome pairs (bivalents so that crossing-over and chiasma formation is facilitated by the proximity of parental homologs induced at the nodal regions of the waves thus created. This model adequately explains the salient features of crossover/chiasma interference, where (1 there is normally at least one crossover/chiasma per bivalent, (2 the number is correlated to bivalent length, (3 the positions are dependent on the number per bivalent, (4 interference distances are on average longer over the centromere than along chromosome arms, and (5 there are significant changes in carriers of structural chromosome rearrangements. Conclusions The crossover/chiasma frequency distribution in humans and mice with normal karyotypes as well as in carriers of structural chromosome rearrangements are those expected on the COM model. Further studies are underway to analyze mechanical/mathematical aspects of this model for the origin of crossover/chiasma interference, using string replicas of the homologous chromosomes at the

  2. Landscape fragmentation and pollinator movement within agricultural environments: a modelling framework for exploring foraging and movement ecology

    Directory of Open Access Journals (Sweden)

    Sean A. Rands

    2014-02-01

    Full Text Available Pollinator decline has been linked to landscape change, through both habitat fragmentation and the loss of habitat suitable for the pollinators to live within. One method for exploring why landscape change should affect pollinator populations is to combine individual-level behavioural ecological techniques with larger-scale landscape ecology. A modelling framework is described that uses spatially-explicit individual-based models to explore the effects of individual behavioural rules within a landscape. The technique described gives a simple method for exploring the effects of the removal of wild corridors, and the creation of wild set-aside fields: interventions that are common to many national agricultural policies. The effects of these manipulations on central-place nesting pollinators are varied, and depend upon the behavioural rules that the pollinators are using to move through the environment. The value of this modelling framework is discussed, and future directions for exploration are identified.

  3. Landscape fragmentation and pollinator movement within agricultural environments: a modelling framework for exploring foraging and movement ecology.

    Science.gov (United States)

    Rands, Sean A

    2014-01-01

    Pollinator decline has been linked to landscape change, through both habitat fragmentation and the loss of habitat suitable for the pollinators to live within. One method for exploring why landscape change should affect pollinator populations is to combine individual-level behavioural ecological techniques with larger-scale landscape ecology. A modelling framework is described that uses spatially-explicit individual-based models to explore the effects of individual behavioural rules within a landscape. The technique described gives a simple method for exploring the effects of the removal of wild corridors, and the creation of wild set-aside fields: interventions that are common to many national agricultural policies. The effects of these manipulations on central-place nesting pollinators are varied, and depend upon the behavioural rules that the pollinators are using to move through the environment. The value of this modelling framework is discussed, and future directions for exploration are identified.

  4. A dual visual-local feedback model of the vergence eye movement system

    NARCIS (Netherlands)

    Erkelens, C.J.

    2011-01-01

    Pure vergence movements are the eye movements that we make when we change our binocular fixation between targets differing in distance but not in direction relative to the head. Pure vergence is slow and controlled by visual feedback. Saccades are the rapid eye movements that we make between targets

  5. Mindless reading revisited: an analysis based on the SWIFT model of eye-movement control.

    Science.gov (United States)

    Nuthmann, Antje; Engbert, Ralf

    2009-02-01

    In this article, we revisit the mindless reading paradigm from the perspective of computational modeling. In the standard version of the paradigm, participants read sentences in both their normal version as well as the transformed (or mindless) version where each letter is replaced with a z. z-String scanning shares the oculomotor requirements with reading but none of the higher-level lexical and semantic processes. Here we use the z-string scanning task to validate the SWIFT model of saccade generation [Engbert, R., Nuthmann, A., Richter, E., & Kliegl, R. (2005). SWIFT: A dynamical model of saccade generation during reading. Psychological Review, 112(4), 777-813] as an example for an advanced theory of eye-movement control in reading. We test the central assumption of spatially distributed processing across an attentional gradient proposed by the SWIFT model. Key experimental results like prolonged average fixation durations in z-string scanning compared to normal reading and the existence of a string-length effect on fixation durations and probabilities were reproduced by the model, which lends support to the model's assumptions on visual processing. Moreover, simulation results for patterns of regressive saccades in z-string scanning confirm SWIFT's concept of activation field dynamics for the selection of saccade targets.

  6. Digestion modeling in the small intestine: impact of dietary fiber.

    Science.gov (United States)

    Taghipoor, M; Barles, G; Georgelin, C; Licois, J R; Lescoat, P

    2014-12-01

    In this work, the modeling of the digestion in the small intestine is developed by investigating specifically the effects of dietary fiber. As our previous model, this new version takes into account the three main phenomena of digestion: transit of the bolus, degradation of feedstuffs and absorption through the intestinal wall. However the two main physiochemical characteristics of dietary fiber, namely viscosity and water holding capacity, lead us to substantially modify our initial model by emphasizing the role of water and its intricated dynamics with dry matter in the bolus. Various numerical simulations given by this new model are qualitatively in agreement with the positive effect of insoluble dietary fiber on the velocity of bolus and on its degradation all along the small intestine. These simulations reproduce the negative effect of soluble dietary fiber on digestion as it has been experimentally observed. Although, this model is generic and contains a large number of parameters but, to the best of our knowledge, it is among the first qualitative dynamical models of fiber influence on intestinal digestion. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Rock glaciers originating from mass movements: A new model based on field data

    Science.gov (United States)

    Reitner, J. M.; Gruber, A.

    2009-04-01

    The morphological and geological conditions for the formation of rock glaciers in Alpine environments seem to be clear according to our present knowledge (BARSCH, 1996; HAEBERLI et al. 2006). All known examples derive from porous more or less coarse grained sedimentary bodies, either from moraines or, in most cases, from talus fans. In the latter case the debris accumulation originates overwhelmingly from physical weathering, rock falls or rock avalanches in proximity to rockwalls. However, in the course of geological mapping in the crystalline areas of Eastern and Northern Tyrol (Schober Gruppe, Tuxer Alpen) we found an additional setting. Some relict rock glaciers occur directly at the bulging toe of bedrock slopes, which had been affected by deep-seated gravitational slope deformations (REITNER, 2003; GRUBER, 2005). Furthermore rock glaciers are also present in ridge-top depressions and similar graben-like features that originated from gravitational processes in jointed bedrock. In all these cases talus fans with debris accumulation are missing in the source area of those rock glaciers. According to our model the disintegration of jointed rocks by creeping mass movements resulted in an increased volume of joint space. This enabled the formation of interstitial ice under permafrost conditions. Increased ice saturation led to the reduction of the angle of internal friction and finally to the initial formation of a rock glacier. Abundant material was provided for the further movement and thus for formation of quite large rock glaciers due to the previous and maybe still ongoing slope deformation. Most rock glaciers of this type originated from mass movements of sagging -type (Sackung sensu ZISCHINSKY, 1966), which illustrates the continuous transition from gravitational to periglacial creep process in high Alpine areas. All studied examples are of Lateglacial age according to the altitude in correspondence to the known amount of permafrost depression compared to

  8. Sculpture, Dance and Heritage: animating dance sequences from temple reliefs using movement modelling software

    Directory of Open Access Journals (Sweden)

    Alessandra Lopez y Royo Iyer

    2001-06-01

    Full Text Available This article discusses research carried out in 1999 at the School of Performing Arts of the University of Surrey, Dance Studies Department. For this research project, computer animation modelling techniques were used to recreate a series of dance movement sequences depicted in the reliefs around the balustrade of the main temple at the Prambanan temple complex in Central Java, built in the 9th century CE. The reconstruction and re-creation of the dance movements from the reliefs are inseparable from the context of the temple complex. The issues of heritage, its interpretation and conservation are also discussed, particularly since the construction of dance as heritage is widespread in Southeast Asia and is linked with tourist consumption of archaeological sites. The article makes a case for the use of computer technology in research areas previously regarded as distinct and disconnected, such as archaeology, art history and dance, and in this specific case study, computer technology has provided a bridge between these disciplines.

  9. Advancing research on animal-transported subsidies by integrating animal movement and ecosystem modelling.

    Science.gov (United States)

    Earl, Julia E; Zollner, Patrick A

    2017-09-01

    Connections between ecosystems via animals (active subsidies) support ecosystem services and contribute to numerous ecological effects. Thus, the ability to predict the spatial distribution of active subsidies would be useful for ecology and conservation. Previous work modelling active subsidies focused on implicit space or static distributions, which treat passive and active subsidies similarly. Active subsidies are fundamentally different from passive subsidies, because animals can respond to the process of subsidy deposition and ecosystem changes caused by subsidy deposition. We propose addressing this disparity by integrating animal movement and ecosystem ecology to advance active subsidy investigations, make more accurate predictions of subsidy spatial distributions, and enable a mechanistic understanding of subsidy spatial distributions. We review selected quantitative techniques that could be used to accomplish integration and lead to novel insights. The ultimate objective for these types of studies is predictions of subsidy spatial distributions from characteristics of the subsidy and the movement strategy employed by animals that transport subsidies. These advances will be critical in informing the management of ecosystem services, species conservation and ecosystem degradation related to active subsidies. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  10. Luminance change generates apparent movement: implications for models of directional specificity in the human visual system.

    Science.gov (United States)

    Mather, G

    1984-01-01

    Two alternative schemes have been proposed for coding the local direction of stimulus motion in the visual image. The "sequence discrimination" scheme (e.g. Barlow H.B. and Levick W. R., J. Physiol., Lond. 178, 477-504, 1965) uses sequential change in stimulus position over time to infer movement direction; the "spatiotemporal derivative" scheme (Marr D.M. and Ullman S., Proc. R. Soc. Lond. B211, 151-180, 1981) uses change in stimulus luminance over space and time at just one position to infer movement direction. To test these models, subjects were shown stimuli which contained combinations of stationary vertical edges and changing luminances over time. They consistently reported either leftward or rightward motion, even though no sequential change in edge location took place. Perceived directions agreed with the predictions of the spatiotemporal derivative scheme. Alternative explanations for the results based on changes in apparent edge location could not account for the data. Previous reports of apparent motion during changes in stimulus luminance are also consistent with the scheme.

  11. A Revised Model for Dosimetry in the Human Small Intestine

    Energy Technology Data Exchange (ETDEWEB)

    John Poston; Nasir U. Bhuiyan; R. Alex Redd; Neil Parham; Jennifer Watson

    2005-02-28

    A new model for an adult human gastrointestinal tract (GIT) has been developed for use in internal dose estimations to the wall of the GIT and to the other organs and tissues of the body from radionuclides deposited in the lumenal contents of the five sections of the GIT. These sections were the esophasgus, stomach, small intestine, upper large intestine, and the lower large intestine. The wall of each section was separated from its lumenal contents.

  12. A Revised Model for Dosimetry in the Human Small Intestine

    International Nuclear Information System (INIS)

    John Poston; Bhuiyan, Nasir U.; Redd, R. Alex; Neil Parham; Jennifer Watson

    2005-01-01

    A new model for an adult human gastrointestinal tract (GIT) has been developed for use in internal dose estimations to the wall of the GIT and to the other organs and tissues of the body from radionuclides deposited in the lumenal contents of the five sections of the GIT. These sections were the esophasgus, stomach, small intestine, upper large intestine, and the lower large intestine. The wall of each section was separated from its lumenal contents

  13. An approach for quantifying small effects in regression models.

    Science.gov (United States)

    Bedrick, Edward J; Hund, Lauren

    2018-04-01

    We develop a novel approach for quantifying small effects in regression models. Our method is based on variation in the mean function, in contrast to methods that focus on regression coefficients. Our idea applies in diverse settings such as testing for a negligible trend and quantifying differences in regression functions across strata. Straightforward Bayesian methods are proposed for inference. Four examples are used to illustrate the ideas.

  14. SIMPLIFIED MATHEMATICAL MODEL OF SMALL SIZED UNMANNED AIRCRAFT VEHICLE LAYOUT

    OpenAIRE

    2016-01-01

    Strong reduction of new aircraft design period using new technology based on artificial intelligence is the key problem mentioned in forecasts of leading aerospace industry research centers. This article covers the approach to devel- opment of quick aerodynamic design methods based on artificial intelligence neural system. The problem is being solved for the classical scheme of small sized unmanned aircraft vehicle (UAV). The principal parts of the method are the mathe- matical model of layou...

  15. Learning models of Human-Robot Interaction from small data.

    Science.gov (United States)

    Zehfroosh, Ashkan; Kokkoni, Elena; Tanner, Herbert G; Heinz, Jeffrey

    2017-07-01

    This paper offers a new approach to learning discrete models for human-robot interaction (HRI) from small data. In the motivating application, HRI is an integral part of a pediatric rehabilitation paradigm that involves a play-based, social environment aiming at improving mobility for infants with mobility impairments. Designing interfaces in this setting is challenging, because in order to harness, and eventually automate, the social interaction between children and robots, a behavioral model capturing the causality between robot actions and child reactions is needed. The paper adopts a Markov decision process (MDP) as such a model, and selects the transition probabilities through an empirical approximation procedure called smoothing. Smoothing has been successfully applied in natural language processing (NLP) and identification where, similarly to the current paradigm, learning from small data sets is crucial. The goal of this paper is two-fold: (i) to describe our application of HRI, and (ii) to provide evidence that supports the application of smoothing for small data sets.

  16. Using GPS telemetry to validate least-cost modeling of gray squirrel (Sciurus carolinensis) movement within a fragmented landscape.

    Science.gov (United States)

    Stevenson, Claire D; Ferryman, Mark; Nevin, Owen T; Ramsey, Andrew D; Bailey, Sallie; Watts, Kevin

    2013-07-01

    In Britain, the population of native red squirrels Sciurus vulgaris has suffered population declines and local extinctions. Interspecific resource competition and disease spread by the invasive gray squirrel Sciurus carolinensis are the main factors behind the decline. Gray squirrels have adapted to the British landscape so efficiently that they are widely distributed. Knowledge on how gray squirrels are using the landscape matrix and being able to predict their movements will aid management. This study is the first to use global positioning system (GPS) collars on wild gray squirrels to accurately record movements and land cover use within the landscape matrix. This data were used to validate Geographical Information System (GIS) least-cost model predictions of movements and provided much needed information on gray squirrel movement pathways and network use. Buffered least-cost paths and least-cost corridors provide predictions of the most probable movements through the landscape and are seen to perform better than the more expansive least-cost networks which include all possible movements. Applying the knowledge and methodologies gained to current gray squirrel expansion areas, such as Scotland and in Italy, will aid in the prediction of potential movement areas and therefore management of the invasive gray squirrel. The methodologies presented in this study could potentially be used in any landscape and on numerous species.

  17. Model Predictive Control for a Small Scale Unmanned Helicopter

    Directory of Open Access Journals (Sweden)

    Jianfu Du

    2008-11-01

    Full Text Available Kinematical and dynamical equations of a small scale unmanned helicoper are presented in the paper. Based on these equations a model predictive control (MPC method is proposed for controlling the helicopter. This novel method allows the direct accounting for the existing time delays which are used to model the dynamics of actuators and aerodynamics of the main rotor. Also the limits of the actuators are taken into the considerations during the controller design. The proposed control algorithm was verified in real flight experiments where good perfomance was shown in postion control mode.

  18. A small Maglev car model using YBCO bulk superconductors

    International Nuclear Information System (INIS)

    Yang, W M; Zhou, L; Yong, Feng; Zhang, P X; Chao, X X; Bian, X B; Zhu, S H; Wu, X L; Liu, P

    2006-01-01

    Models of two small Maglev cars have been made. The track was paved with NdFeB magnets. The arrangement of the magnets made it easy to get a uniform magnetic field distribution along the length of the track and a magnetic field gradient in the lateral direction. When the car with YBCO bulk superconductors was field cooled to LN 2 temperature at a certain distance above the track, the car could be automatically levitated over the track and moved along the track without any obvious friction. The model can be used to demonstrate the Meissner effect and a fast transportation system to students and adults

  19. Small velocity and finite temperature variations in kinetic relaxation models

    KAUST Repository

    Markowich, Peter

    2010-01-01

    A small Knuden number analysis of a kinetic equation in the diffusive scaling is performed. The collision kernel is of BGK type with a general local Gibbs state. Assuming that the flow velocity is of the order of the Knudsen number, a Hilbert expansion yields a macroscopic model with finite temperature variations, whose complexity lies in between the hydrodynamic and the energy-transport equations. Its mathematical structure is explored and macroscopic models for specific examples of the global Gibbs state are presented. © American Institute of Mathematical Sciences.

  20. ORDEM2010 and MASTER-2009 Modeled Small Debris Population Comparison

    Science.gov (United States)

    Krisko, Paula H.; Flegel, S.

    2010-01-01

    The latest versions of the two premier orbital debris engineering models, NASA s ORDEM2010 and ESA s MASTER-2009, have been publicly released. Both models have gone through significant advancements since inception, and now represent the state-of-the-art in orbital debris knowledge of their respective agencies. The purpose of these models is to provide satellite designers/operators and debris researchers with reliable estimates of the artificial debris environment in near-Earth orbit. The small debris environment within the size range of 1 mm to 1 cm is of particular interest to both human and robotic spacecraft programs. These objects are much more numerous than larger trackable debris but are still large enough to cause significant, if not catastrophic, damage to spacecraft upon impact. They are also small enough to elude routine detection by existing observation systems (radar and telescope). Without reliable detection the modeling of these populations has always coupled theoretical origins with supporting observational data in different degrees. This paper details the 1 mm to 1 cm orbital debris populations of both ORDEM2010 and MASTER-2009; their sources (both known and presumed), current supporting data and theory, and methods of population analysis. Fluxes on spacecraft for chosen orbits are also presented and discussed within the context of each model.

  1. Modelling foraging movements of diving predators: a theoretical study exploring the effect of heterogeneous landscapes on foraging efficiency.

    Science.gov (United States)

    Chimienti, Marianna; Bartoń, Kamil A; Scott, Beth E; Travis, Justin M J

    2014-01-01

    Foraging in the marine environment presents particular challenges for air-breathing predators. Information about prey capture rates, the strategies that diving predators use to maximise prey encounter rates and foraging success are still largely unknown and difficult to observe. As well, with the growing awareness of potential climate change impacts and the increasing interest in the development of renewable sources it is unknown how the foraging activity of diving predators such as seabirds will respond to both the presence of underwater structures and the potential corresponding changes in prey distributions. Motivated by this issue we developed a theoretical model to gain general understanding of how the foraging efficiency of diving predators may vary according to landscape structure and foraging strategy. Our theoretical model highlights that animal movements, intervals between prey capture and foraging efficiency are likely to critically depend on the distribution of the prey resource and the size and distribution of introduced underwater structures. For multiple prey loaders, changes in prey distribution affected the searching time necessary to catch a set amount of prey which in turn affected the foraging efficiency. The spatial aggregation of prey around small devices (∼ 9 × 9 m) created a valuable habitat for a successful foraging activity resulting in shorter intervals between prey captures and higher foraging efficiency. The presence of large devices (∼ 24 × 24 m) however represented an obstacle for predator movement, thus increasing the intervals between prey captures. In contrast, for single prey loaders the introduction of spatial aggregation of the resources did not represent an advantage suggesting that their foraging efficiency is more strongly affected by other factors such as the timing to find the first prey item which was found to occur faster in the presence of large devices. The development of this theoretical model represents a useful

  2. Osteogenic Activity of Locally Applied Small Molecule Drugs in a Rat Femur Defect Model

    Directory of Open Access Journals (Sweden)

    Jessica A. Cottrell

    2010-01-01

    Full Text Available The long-term success of arthroplastic joints is dependent on the stabilization of the implant within the skeletal site. Movement of the arthroplastic implant within the bone can stimulate osteolysis, and therefore methods which promote rigid fixation or bone growth are expected to enhance implant stability and the long-term success of joint arthroplasty. In the present study, we used a simple bilateral bone defect model to analyze the osteogenic activity of three small-molecule drug implants via microcomputerized tomography (micro-CT and histomorphometry. In this study, we show that local delivery of alendronate, but not lovastatin or omeprazole, led to significant new bone formation at the defect site. Since alendronate impedes osteoclast-development, it is theorized that alendronate treatment results in a net increase in bone formation by preventing osteoclast mediated remodeling of the newly formed bone and upregulating osteoblasts.

  3. ON DISCRETE STRUCTURE OF GEOLOGIC MEDIUM AND CONTINUAL APPROACH TO MODELING ITS MOVEMENTS

    Directory of Open Access Journals (Sweden)

    Sh. A. Mukhamediev

    2016-01-01

    Full Text Available This paper discusses the structure of a geologic medium represented by accessible lithified rocks and provides an overview of methods used to describe its movements. Two basic opinions are considered in the framework of the discussion: (1 an initially homogeneous and continuous geologic medium acquires the structure composed of blocks in the process of the geologic medium’s deformation/destruction/degradation, and (2 a geologic medium is composed of blocks (and often has hierarchic, active, energy-saturated features, and the continuity model is thus not valid for describing the geologic medium’s deformation. Proponents of the first point of view actively apply the standard or modified continuum model of a solid deformed body (SDB in estimations of the stress-strain state, but the input parameters of this model do not contain any information on discreteness in principle. Authors who support the second opinion, either explicitly or implicitly assume that the block structure of the geologic medium, which is detectable by geological methods, makes a direct and unambiguous impact on all other mechanical properties of the geologic medium and, above all, on the nature of its movements.Based on results obtained by interpreting the data collected in our long-term field studies of rock fracturing, mathematical processing of GPS-measurements, and theoretical models, we agree with the concept of the geologic medium’s block structure, but argue that the geologic block-structure property is not acquired but congenital. Regarding sedimentary rocks, it means that the discrete structure has been already embodied in the rock before sediment lithification, regardless of the intensity of macroscopic deformations. A discrete structure is the form of the geologic medium existence and a cause of the congenital anisotropy of the geologic medium’s strength characteristics. Due to subsequent deformation of the geologic medium, some elements of the structure can

  4. Project Finance Model for Small Contractors in USA

    Directory of Open Access Journals (Sweden)

    Jawahar Nesan

    2012-11-01

    Full Text Available Construction projects do not require a large capital outlay but a large working capital to start up the project. Unfortunately, for small contractors there are very limited options available from the banks or other lending institutions to cover this large working capital requirement in the absence of sufficient collateral. The “Project Finance” method presented in this paper is recommended as the most effective method for small contractors in the United States. The problems of small and start up contractors in funding their projects have been little addressed in the literature. The current financing practices were observed through both the literature review and interviews with contractors and bankers in the western Michigan area and subsequently a system has been proposed which could help a small start-up company seeking higher growth. The growth rates that can be achieved using the project finance system in contrast to the traditional “line of credit” arrangements as illustrated in this paper show that the project finance model is beneficial.

  5. A Model of the Smooth Pursuit Eye Movement with Prediction and Learning

    Directory of Open Access Journals (Sweden)

    Davide Zambrano

    2010-01-01

    Full Text Available Smooth pursuit is one of the five main eye movements in humans, consisting of tracking a steadily moving visual target. Smooth pursuit is a good example of a sensory-motor task that is deeply based on prediction: tracking a visual target is not possible by correcting the error between the eye and the target position or velocity with a feedback loop, but it is only possible by predicting the trajectory of the target. This paper presents a model of smooth pursuit based on prediction and learning. It starts from amodel of the neuro-physiological system proposed by Shibata and Schaal (Shibata et al., Neural Networks, vol. 18, pp. 213-224, 2005. The learning component added here decreases the prediction time in the case of target dynamics already experienced by the system. In the implementation described here, the convergence time is, after the learning phase, 0.8 s.

  6. Numeric simulation model for long-term orthodontic tooth movement with contact boundary conditions using the finite element method.

    Science.gov (United States)

    Hamanaka, Ryo; Yamaoka, Satoshi; Anh, Tuan Nguyen; Tominaga, Jun-Ya; Koga, Yoshiyuki; Yoshida, Noriaki

    2017-11-01

    Although many attempts have been made to simulate orthodontic tooth movement using the finite element method, most were limited to analyses of the initial displacement in the periodontal ligament and were insufficient to evaluate the effect of orthodontic appliances on long-term tooth movement. Numeric simulation of long-term tooth movement was performed in some studies; however, neither the play between the brackets and archwire nor the interproximal contact forces were considered. The objectives of this study were to simulate long-term orthodontic tooth movement with the edgewise appliance by incorporating those contact conditions into the finite element model and to determine the force system when the space is closed with sliding mechanics. We constructed a 3-dimensional model of maxillary dentition with 0.022-in brackets and 0.019 × 0.025-in archwire. Forces of 100 cN simulating sliding mechanics were applied. The simulation was accomplished on the assumption that bone remodeling correlates with the initial tooth displacement. This method could successfully represent the changes in the moment-to-force ratio: the tooth movement pattern during space closure. We developed a novel method that could simulate the long-term orthodontic tooth movement and accurately determine the force system in the course of time by incorporating contact boundary conditions into finite element analysis. It was also suggested that friction is progressively increased during space closure in sliding mechanics. Copyright © 2017. Published by Elsevier Inc.

  7. An empirical model of glacio-isostatic movements and shore-level displacement in Fennoscandia

    International Nuclear Information System (INIS)

    Paasse, T.

    2001-08-01

    Shore-level displacement in Fennoscandia is mainly due to two co-operative vertical movements, glacio-isostatic uplift and global eustatic sea level rise. The course of the glacio-isostatic uplift has been made discernible according to an investigation of the lake-tilting phenomenon. This information made it possible to start an iteration process that has given mathematical expression for factors involved both within the isostatic movements and the eustatic rise. There are two components involved in glacio-isostatic uplift. The main uplift, still in progress, acts slowly and is thus called the slow component. Arctan functions have proved to be suitable tools for describing the slow component. There are two main factors involved in the function used for calculation; A s (m), the download factor and B s (y -1 ), which is an inertia factor. A strong linear correlation between the inertia factor Bs and lithosphere thickness has been found in the model. There was also a fast component involved in the crustal changes at the end of Late Weichselian and early Holocene. This component gave rise to fast subsidence followed by fast uplift during the final part of the deglaciation. Crustal subsidence is assumed to be due to reloading of the crust in the central parts of Fennoscandia during the Younger Dryas stadial. Normal distribution functions are used for calculating this component. Glacio-isostatic uplift and thus a regressive shore-level displacement was extremely rapid around 10,300 years BP. This fast regression was contemporaneous and occurred in a similar way at the West Coasts of Norway and Sweden as well as in the Baltic. The 'drainage' of the Baltic Ice Lake has been interpreted in the model as due to this fast regression. The slow component is most probably due to viscous flow in the asthenosphere and the fast component is assumed to be due to its elasticity

  8. An empirical model of glacio-isostatic movements and shore-level displacement in Fennoscandia

    Energy Technology Data Exchange (ETDEWEB)

    Paasse, T. [Geological Survey of Sweden, Uppsala (Sweden)

    2001-08-01

    Shore-level displacement in Fennoscandia is mainly due to two co-operative vertical movements, glacio-isostatic uplift and global eustatic sea level rise. The course of the glacio-isostatic uplift has been made discernible according to an investigation of the lake-tilting phenomenon. This information made it possible to start an iteration process that has given mathematical expression for factors involved both within the isostatic movements and the eustatic rise. There are two components involved in glacio-isostatic uplift. The main uplift, still in progress, acts slowly and is thus called the slow component. Arctan functions have proved to be suitable tools for describing the slow component. There are two main factors involved in the function used for calculation; A{sub s} (m), the download factor and B{sub s} (y{sup -1} ), which is an inertia factor. A strong linear correlation between the inertia factor Bs and lithosphere thickness has been found in the model. There was also a fast component involved in the crustal changes at the end of Late Weichselian and early Holocene. This component gave rise to fast subsidence followed by fast uplift during the final part of the deglaciation. Crustal subsidence is assumed to be due to reloading of the crust in the central parts of Fennoscandia during the Younger Dryas stadial. Normal distribution functions are used for calculating this component. Glacio-isostatic uplift and thus a regressive shore-level displacement was extremely rapid around 10,300 years BP. This fast regression was contemporaneous and occurred in a similar way at the West Coasts of Norway and Sweden as well as in the Baltic. The 'drainage' of the Baltic Ice Lake has been interpreted in the model as due to this fast regression. The slow component is most probably due to viscous flow in the asthenosphere and the fast component is assumed to be due to its elasticity.

  9. Fighting Columns in Small Wars: An OMFTS Model

    Science.gov (United States)

    2000-01-01

    the People’s Movement for the Liberation of Angola (MPLA), a Marxist movement under the leadership of Agostinho Neto. The United Nations (UN...with the theater of combat operations, destroyed these efforts. Angolan President dos Santos , advised by military experts from Cuba and the Soviet

  10. Modeling Small-Amplitude Perturbations in Inertial Confinement Fusion Pellets

    Science.gov (United States)

    Zalesak, Steven; Metzler, N.; Velikovich, A. L.; Gardner, J. H.; Manheimer, W.

    2005-10-01

    Recent advances in inertial confinement fusion (ICF) technology serve to ensure that imploding laser-driven ICF pellets will spend a significantly larger portion of their time in what is regarded as the ``linear'' portion of their perturbation evolution, i.e., in the presence of small-amplitude but nonetheless evolving perturbations. Since the evolution of these linear perturbations collectively form the initial conditions for the subsequent nonlinear evolution of the pellet, which in turn determines the energy yield of the pellet, the accurate numerical modeling of these small-amplitude perturbations has taken on an increased importance. This modeling is difficult despite the expected linear evolution of the perturbations themselves, because these perturbations are embedded in a highly nonlinear, strongly-shocked, and highly complex flow field which in and of itself stresses numerical computation capabilities, and whose simulation often employs numerical techniques which were not designed with the proper treatment of small-amplitude perturbations in mind. In this paper we will review some of the techniques that we have recently found to be of use toward this end.

  11. Predicting the Direction of Stock Market Index Movement Using an Optimized Artificial Neural Network Model.

    Science.gov (United States)

    Qiu, Mingyue; Song, Yu

    2016-01-01

    In the business sector, it has always been a difficult task to predict the exact daily price of the stock market index; hence, there is a great deal of research being conducted regarding the prediction of the direction of stock price index movement. Many factors such as political events, general economic conditions, and traders' expectations may have an influence on the stock market index. There are numerous research studies that use similar indicators to forecast the direction of the stock market index. In this study, we compare two basic types of input variables to predict the direction of the daily stock market index. The main contribution of this study is the ability to predict the direction of the next day's price of the Japanese stock market index by using an optimized artificial neural network (ANN) model. To improve the prediction accuracy of the trend of the stock market index in the future, we optimize the ANN model using genetic algorithms (GA). We demonstrate and verify the predictability of stock price direction by using the hybrid GA-ANN model and then compare the performance with prior studies. Empirical results show that the Type 2 input variables can generate a higher forecast accuracy and that it is possible to enhance the performance of the optimized ANN model by selecting input variables appropriately.

  12. Hidden Markov model analysis reveals the advantage of analytic eye movement patterns in face recognition across cultures.

    Science.gov (United States)

    Chuk, Tim; Crookes, Kate; Hayward, William G; Chan, Antoni B; Hsiao, Janet H

    2017-12-01

    It remains controversial whether culture modulates eye movement behavior in face recognition. Inconsistent results have been reported regarding whether cultural differences in eye movement patterns exist, whether these differences affect recognition performance, and whether participants use similar eye movement patterns when viewing faces from different ethnicities. These inconsistencies may be due to substantial individual differences in eye movement patterns within a cultural group. Here we addressed this issue by conducting individual-level eye movement data analysis using hidden Markov models (HMMs). Each individual's eye movements were modeled with an HMM. We clustered the individual HMMs according to their similarities and discovered three common patterns in both Asian and Caucasian participants: holistic (looking mostly at the face center), left-eye-biased analytic (looking mostly at the two individual eyes in addition to the face center with a slight bias to the left eye), and right-eye-based analytic (looking mostly at the right eye in addition to the face center). The frequency of participants adopting the three patterns did not differ significantly between Asians and Caucasians, suggesting little modulation from culture. Significantly more participants (75%) showed similar eye movement patterns when viewing own- and other-race faces than different patterns. Most importantly, participants with left-eye-biased analytic patterns performed significantly better than those using either holistic or right-eye-biased analytic patterns. These results suggest that active retrieval of facial feature information through an analytic eye movement pattern may be optimal for face recognition regardless of culture. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Effect of Boards in Small-Sided Street Soccer Games on Movement Pattern and Physiological Response in Recreationally Active Young Men

    DEFF Research Database (Denmark)

    Randers, Morten B; Brix, Jonathan; Hagman, Marie

    2018-01-01

    after WB than after WOB (7.1±1.0 vs. 5.5±1.2, p conclusion, intensity was sufficiently high in both game formats to expect short- and long-term health improvements as a result of regular participation. Boards affected movement pattern and physiological demands, producing higher......The present study investigated whether street soccer might be proposed as an alternative to recreational small-sided games on grass as a health-enhancing activity, and specifically the effects of the boards surrounding the pitch. Eleven recreationally active young males (28.4±4.2 (±SD) yrs, 19...... used to evaluate exercise intensity and physiological strain. Total number of accelerations (19%) and Player Load (18%) were higher (p whereas total distance covered (12%), high-speed running (59%) and peak speed (11%) were lower (p Moreover, HRmean...

  14. Correcting Model Fit Criteria for Small Sample Latent Growth Models with Incomplete Data

    Science.gov (United States)

    McNeish, Daniel; Harring, Jeffrey R.

    2017-01-01

    To date, small sample problems with latent growth models (LGMs) have not received the amount of attention in the literature as related mixed-effect models (MEMs). Although many models can be interchangeably framed as a LGM or a MEM, LGMs uniquely provide criteria to assess global data-model fit. However, previous studies have demonstrated poor…

  15. Recent crustal movements

    Science.gov (United States)

    Maelzer, H.

    Calculation of temporal height changes for the determination of recent vertical crustal movements in northern, western, and southern Germany is described. Precise geodetic measurements and their analysis for the determination of recent crustal movements in north-eastern Iceland, western Venezuela, and central Peru are described. Determination of recent vertical crustal movements by leveling and gravity data; geodetic modeling of deformations and recent crustal movements; geodetic modeling of plate motions; and instrumental developments in geodetic measuring are discussed.

  16. Dynamic model of the vergence eye movement system: simulations using MATLAB/SIMULINK.

    Science.gov (United States)

    Hung, G K

    1998-01-01

    A dynamic model of the vergence eye movement system was developed and simulated using MATLAB/SIMULINK. The model was based on a dual-mode dynamic model previously written in FORTRAN. It consisted of a fast open-loop component and a slow closed-loop component. The new model contained several important modifications. For example, in the fast component, a zero-order hold element replaced the sampler and the target trajectory estimator in the earlier model to provide more stable and accurate responses. Also, a periodicity detector was added to automatically detect periodicity in the stimulus waveform. The stored periodic stimulus, with a reduction in latency, was used to drive the fast component output. Moreover, a connection representing the efference copy signal was added from the fast component output to the disparity input to provide an accurate estimate of the stimulus waveform. Further, Robinson's model of the extraocular muscles replaced the earlier 2nd-order plant to provide more realistic muscle dynamics. The entire model, containing the fast and slow components, was simulated using a variety of stimuli such as pulses, positive and negative ramps, square-wave, and sine-wave. The responses showed dynamic characteristics similar to experimental results. Thus, this new MATLAB/SIMULINK program provides a relatively easy-to-use, versatile, and powerful simulation environment for investigating the basic as well as clinical aspects of vergence dynamics. Moreover, the simulation program has general characteristics that can be modified to represent other oculomotor systems such as the versional and accommodation systems. This provides a framework for future investigation of dynamic interactions between oculomotor systems.

  17. A simple physical model predicts small exon length variations.

    Directory of Open Access Journals (Sweden)

    2006-04-01

    Full Text Available One of the most common splice variations are small exon length variations caused by the use of alternative donor or acceptor splice sites that are in very close proximity on the pre-mRNA. Among these, three-nucleotide variations at so-called NAGNAG tandem acceptor sites have recently attracted considerable attention, and it has been suggested that these variations are regulated and serve to fine-tune protein forms by the addition or removal of a single amino acid. In this paper we first show that in-frame exon length variations are generally overrepresented and that this overrepresentation can be quantitatively explained by the effect of nonsense-mediated decay. Our analysis allows us to estimate that about 50% of frame-shifted coding transcripts are targeted by nonsense-mediated decay. Second, we show that a simple physical model that assumes that the splicing machinery stochastically binds to nearby splice sites in proportion to the affinities of the sites correctly predicts the relative abundances of different small length variations at both boundaries. Finally, using the same simple physical model, we show that for NAGNAG sites, the difference in affinities of the neighboring sites for the splicing machinery accurately predicts whether splicing will occur only at the first site, splicing will occur only at the second site, or three-nucleotide splice variants are likely to occur. Our analysis thus suggests that small exon length variations are the result of stochastic binding of the spliceosome at neighboring splice sites. Small exon length variations occur when there are nearby alternative splice sites that have similar affinity for the splicing machinery.

  18. Development of a system model for advanced small modular reactors.

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Tom Goslee,; Holschuh, Thomas Vernon,

    2014-01-01

    This report describes a system model that can be used to analyze three advance small modular reactor (SMR) designs through their lifetime. Neutronics of these reactor designs were evaluated using Monte Carlo N-Particle eXtended (MCNPX/6). The system models were developed in Matlab and Simulink. A major thrust of this research was the initial scoping analysis of Sandias concept of a long-life fast reactor (LLFR). The inherent characteristic of this conceptual design is to minimize the change in reactivity over the lifetime of the reactor. This allows the reactor to operate substantially longer at full power than traditional light water reactors (LWRs) or other SMR designs (e.g. high temperature gas reactor (HTGR)). The system model has subroutines for lifetime reactor feedback and operation calculations, thermal hydraulic effects, load demand changes and a simplified SCO2 Brayton cycle for power conversion.

  19. Utility of Small Animal Models of Developmental Programming.

    Science.gov (United States)

    Reynolds, Clare M; Vickers, Mark H

    2018-01-01

    Any effective strategy to tackle the global obesity and rising noncommunicable disease epidemic requires an in-depth understanding of the mechanisms that underlie these conditions that manifest as a consequence of complex gene-environment interactions. In this context, it is now well established that alterations in the early life environment, including suboptimal nutrition, can result in an increased risk for a range of metabolic, cardiovascular, and behavioral disorders in later life, a process preferentially termed developmental programming. To date, most of the mechanistic knowledge around the processes underpinning development programming has been derived from preclinical research performed mostly, but not exclusively, in laboratory mouse and rat strains. This review will cover the utility of small animal models in developmental programming, the limitations of such models, and potential future directions that are required to fully maximize information derived from preclinical models in order to effectively translate to clinical use.

  20. Hydro-morphological modelling of small, wave-dominated estuaries

    Science.gov (United States)

    Slinger, Jill H.

    2017-11-01

    Small, intermittently open or closed estuaries are characteristic of the coasts of South Africa, Australia, California, Mexico and many other areas of the world. However, modelling attention has tended to focus on big estuaries that drain large catchments and serve a wide diversity of interests e.g. agriculture, urban settlement, recreation, commercial fishing. In this study, the development of a simple, parametric, system dynamics model to simulate the opening and closure of the mouths of small, wave-dominated estuaries is reported. In the model, the estuary is conceived as a basin with a specific water volume to water level relationship, connected to the sea by a channel of fixed width, but variable sill height. Changes in the form of the basin are not treated in the model, while the dynamics of the mouth channel are central to the model. The magnitude and direction of the flow through the mouth determines whether erosion or deposition of sediment occurs in the mouth channel, influencing the sill height. The model is implemented on the Great Brak Estuary in South Africa and simulations reveal that the raised low water levels in the estuary during spring tide relative to neap tide, are occasioned by the constriction of the tidal flow through the shallow mouth. Freshwater inflows to the estuary are shown to be significant in determining the behaviour of the inlet mouth, a factor often ignored in studies on tidal inlets. Further it is the balance between freshwater inflows and wave events that determines the opening or closure of the mouth of a particular estuary.

  1. Modeling studies of gas movement and moisture migration at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, Y.W.; Pruess, K. [Lawrence Berkeley Lab., CA (United States)

    1991-06-01

    Modeling studies on moisture redistribution processes that are mediated by gas phase flow and diffusion have been carried out. The problem addressed is the effect of a lowered humidity of the soil gas at the land surface on moisture removal from Yucca Mountain, the potential site for a high-level nuclear waste repository. At the land surface, humid formation gas contacts much drier atmospheric air. Near this contact, the humidity of the soil gas may be considerably lower than at greater depth, where the authors expect equilibrium with the liquid phase and close to 100% humidity. The lower relative humidity of the soil gas may be modeled by imposing, at the land surface, an additional negative capillary suction corresponding to vapor pressure lowering according to Kelvin`s Equation, thus providing a driving force for the upward movement of moisture in both the vapor and liquid phases. Sensitivity studies show that moisture removal from Yucca Mountain arising from the lowered-relative-humidity boundary condition is controlled by vapor diffusion. There is much experimental evidence in the soil literature that diffusion of vapor is enhanced due to pore-level phase change effects by a few orders of magnitude. Modeling results presented here will account for this enhancement in vapor diffusion.

  2. Modelling ground movements at Campi Flegrei caldera (Italy): the role of the shallow geothermal system

    Science.gov (United States)

    Troiano, Antonio; Giulia di Giuseppe, Maria; Petrillo, Zaccaria; Troise, Claudia; de Natale, Giuseppe

    2010-05-01

    Campi Flegrei caldera is characterized by large ground movements, well known since Roman times. Superimposed to a general secular subsidence occurring at a rate of 1.5-2.0 cm/year, an episode of sharp uplift is in progress since 1969, with peak rates up to 1 m/year (in 1982-1984), similar to another episode which culminated with the 1538 eruption. Peak uplift episodes are often followed by some amount of subsidence, which prevent a simple interpretation in terms of purely magmatic inflation phenomena. Such up and down episodes of ground deformations are rather common at large calderas, like in Yellowstone (USA), Long Valley (USA), etc. Here we propose an interpretation based on a mixed mechanical-fluid-dynamical model, in which part of the uplift is generated by increase of water pressure in the shallow geothermal system, as a response to rapid inflow of magmatic fluids exsolved from a deeper magma chamber. We use the program THOUGH2 to model the changes of temperature and pressure in the geothermal system due to the magmatic fluids inflow. Changes in pressure in the caldera volume are then used to compute ground deformations. This way, a theoretical time evolution of ground deformation has been obtained, which compares well with the observed one, if appropriate values of permeability are used. We discuss the implication of such a model for eruption forecast purposes, and the extent at which the required values of permeability can be really representative of the real medium.

  3. MODELING THE VERY SMALL SCALE CLUSTERING OF LUMINOUS RED GALAXIES

    International Nuclear Information System (INIS)

    Watson, Douglas F.; Berlind, Andreas A.; McBride, Cameron K.; Masjedi, Morad

    2010-01-01

    We model the small-scale clustering of luminous red galaxies (LRGs) in the Sloan Digital Sky Survey. Specifically, we use the halo occupation distribution formalism to model the projected two-point correlation function of LRGs on scales well within the sizes of their host halos (0.016 h -1 Mpc ≤ r ≤ 0.42 h -1 Mpc). We start by varying P(N|M), the probability distribution that a dark matter halo of mass M contains N LRGs, and assuming that the radial distribution of satellite LRGs within halos traces the Navarro-Frenk-White (NFW) dark matter density profile. We find that varying P(N|M) alone is not sufficient to match the small-scale data. We next allow the concentration of satellite LRG galaxies to differ from that of dark matter and find that this is also not sufficient. Finally, we relax the assumption of an NFW profile and allow the inner slope of the density profile to vary. We find that this model provides a good fit to the data and the resulting value of the slope is -2.17 ± 0.12. The radial density profile of satellite LRGs within halos is thus not compatible with that of the underlying dark matter, but rather is closer to an isothermal distribution.

  4. Gaining Efficiency of Computational Experiments in Modeling the Flight Vehicle Movement

    Directory of Open Access Journals (Sweden)

    I. K. Romanova

    2017-01-01

    -dimensional cube, where N is the number of variable parameters, the calculations of functions on which meet the specified accuracy.In computational experiments the grid sizes have been increased step-by-step, with the data sets being reconstructed and the residuals being calculated. The tolerance values were visualized using the level lines on the functions of errors. Special attention was paid to the pitching moment, which is directly connected with the stability problem of of the body movement. Here not only answering the question on the mean square error of calculations is important, but also the change of the sign of the moment coefficient.It turned out that despite the available errors, there was no sign change observed. We have also identified areas of overstatement and understatement of the aerodynamic coefficients (ADC when using the larger grids. Noted that when preparing the grid, the prerequisite is to identify areas of finding the system at the boundaries of stability.The calculation results have shown that as compared to the exact calculations the moment is underestimated. Moreover, taking into account the opposite sign of the dependence on the angle of attack in modulus, the moment is overstated; there are overestimations of the lifting force, resistance in the modulus and damping in the operating range.The choice of the optimal grid for evaluation of the mean square error led to a rather small grid, so a capability to introduce a grid of the variable size was considered. It was proposed to divide the grid into two parts. In the region of problem areas an estimate of the allowable increase of size is based on the analysis of a Pareto front of the relative derivative (increment function. After scaling we have obtained the Nash equilibrium point. For the remaining areas the grid is to be selected either according to the tolerable error (with a constant size or using an equality principle of the function increments.The proposed approach to select the mixed grids enables

  5. Analysing movements in investor’s risk aversion using the Heston volatility model

    Directory of Open Access Journals (Sweden)

    Alexie ALUPOAIEI

    2013-03-01

    Full Text Available In this paper we intend to identify and analyze, if it is the case, an “epidemiological” relationship between forecasts of professional investors and short-term developments in the EUR/RON exchange rate. Even that we don’t call a typical epidemiological model as those ones used in biology fields of research, we investigated the hypothesis according to which after the Lehman Brothers crash and implicit the generation of the current financial crisis, the forecasts of professional investors pose a significant explanatory power on the futures short-run movements of EUR/RON. How does it work this mechanism? Firstly, the professional forecasters account for the current macro, financial and political states, then they elaborate forecasts. Secondly, based on that forecasts they get positions in the Romanian exchange market for hedging and/or speculation purposes. But their positions incorporate in addition different degrees of uncertainty. In parallel, a part of their anticipations are disseminated to the public via media channels. Since some important movements are viewed within macro, financial or political fields, the positions of professsional investors from FX derivative market are activated. The current study represents a first step in that direction of analysis for Romanian case. For the above formulated objectives, in this paper different measures of EUR/RON rate volatility have been estimated and compared with implied volatilities. In a second timeframe we called the co-integration and dynamic correlation based tools in order to investigate the relationship between implied volatility and daily returns of EUR/RON exchange rate.

  6. Modelling and Simulation of the Knee Joint with a Depth Sensor Camera for Prosthetics and Movement Rehabilitation

    Science.gov (United States)

    Risto, S.; Kallergi, M.

    2015-09-01

    The purpose of this project was to model and simulate the knee joint. A computer model of the knee joint was first created, which was controlled by Microsoft's Kinect for Windows. Kinect created a depth map of the knee and lower leg motion independent of lighting conditions through an infrared sensor. A combination of open source software such as Blender, Python, Kinect SDK and NI_Mate were implemented for the creation and control of the simulated knee based on movements of a live physical model. A physical size model of the knee and lower leg was also created, the movement of which was controlled remotely by the computer model and Kinect. The real time communication of the model and the robotic knee was achieved through programming in Python and Arduino language. The result of this study showed that Kinect in the modelling of human kinematics and can play a significant role in the development of prosthetics and other assistive technologies.

  7. Inferring spatial memory and spatiotemporal scaling from GPS data: comparing red deer Cervus elaphus movements with simulation models.

    Science.gov (United States)

    Gautestad, Arild O; Loe, Leif E; Mysterud, Atle

    2013-05-01

    1. Increased inference regarding underlying behavioural mechanisms of animal movement can be achieved by comparing GPS data with statistical mechanical movement models such as random walk and Lévy walk with known underlying behaviour and statistical properties. 2. GPS data are typically collected with ≥ 1 h intervals not exactly tracking every mechanistic step along the movement path, so a statistical mechanical model approach rather than a mechanistic approach is appropriate. However, comparisons require a coherent framework involving both scaling and memory aspects of the underlying process. Thus, simulation models have recently been extended to include memory-guided returns to previously visited patches, that is, site fidelity. 3. We define four main classes of movement, differing in incorporation of memory and scaling (based on respective intervals of the statistical fractal dimension D and presence/absence of site fidelity). Using three statistical protocols to estimate D and site fidelity, we compare these main movement classes with patterns observed in GPS data from 52 females of red deer (Cervus elaphus). 4. The results show best compliance with a scale-free and memory-enhanced kind of space use; that is, a power law distribution of step lengths, a fractal distribution of the spatial scatter of fixes and site fidelity. 5. Our study thus demonstrates how inference regarding memory effects and a hierarchical pattern of space use can be derived from analysis of GPS data. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

  8. Cognitive mechanisms of visuomotor transformation in movement imitation: examining predictions based on models of apraxia and motor control.

    Science.gov (United States)

    Gravenhorst, Robynne M; Walter, Charles B

    2009-11-01

    When we observe a movement and then reproduce it, how is this visual input transformed into motor output? Studies on stroke patients with apraxia suggest that there may be two distinct routes used for gesture imitation; an indirect route that recruits stored movement memories (motor programs) and a direct route that bypasses them. The present study examined 30 healthy adults ages 18-80 (mean age=44.0 years, SD=19.5) to learn how motor programs are recruited or bypassed in movement imitation depending upon task conditions (whether familiar letters or novel shapes are imitated) and perceptual factors (whether shapes or letters are perceived). Subjects were asked to imitate the movements of a model who formed shapes and letters on a sheer mesh screen, and to report whether they perceived the task as a shape or a letter. Movements were recorded using a Vicon motion analysis system, and subsequently analyzed to determine the degree of difference between the demonstrated and produced movements. As predicted, letter perception on the letter tasks resulted in increased temporal error when the demonstrated stroke order conflicted with subjects' habitual pattern of letter formation. No such interference effects were observed when the letter tasks were perceived as shapes. These findings are discussed in the context of current theories on imitation, and implications for rehabilitation and motor re-learning are presented.

  9. Building a Scoring Model for Small and Medium Enterprises

    Directory of Open Access Journals (Sweden)

    Răzvan Constantin CARACOTA

    2010-09-01

    Full Text Available The purpose of the paper is to produce a scoring model for small and medium enterprises seeking financing through a bank loan. To analyze the loan application, scoring system developed for companies is as follows: scoring quantitative factors and scoring qualitative factors. We have estimated the probability of default using logistic regression. Regression coefficients determination was made with a solver in Excel using five ratios as input data. Analyses and simulations were conducted on a sample of 113 companies, all accepted for funding. Based on financial information obtained over two years, 2007 and 2008, we could establishe and appreciate the default value.

  10. Modeling Snow Regime in Cores of Small Planetary Bodies

    Science.gov (United States)

    Boukaré, C. E.; Ricard, Y. R.; Parmentier, E.; Parman, S. W.

    2017-12-01

    Observations of present day magnetic field on small planetary bodies such as Ganymede or Mercury challenge our understanding of planetary dynamo. Several mechanisms have been proposed to explain the origin of magnetic fields. Among the proposed scenarios, one family of models relies on snow regime. Snow regime is supported by experimental studies showing that melting curves can first intersect adiabats in regions where the solidifying phase is not gravitationaly stable. First solids should thus remelt during their ascent or descent. The effect of the snow zone on magnetic field generation remains an open question. Could magnetic field be generated in the snow zone? If not, what is the depth extent of the snow zone? How remelting in the snow zone drive compositional convection in the liquid layer? Several authors have tackled this question with 1D-spherical models. Zhang and Schubert, 2012 model sinking of the dense phase as internally heated convection. However, to our knowledge, there is no study on the convection structure associated with sedimentation and phase change at planetary scale. We extend the numerical model developped in [Boukare et al., 2017] to model snow dynamics in 2D Cartesian geometry. We build a general approach for modeling double diffusive convection coupled with solid-liquid phase change and phase separation. We identify several aspects that may govern the convection structure of the solidifying system: viscosity contrast between the snow zone and the liquid layer, crystal size, rate of melting/solidification and partitioning of light components during phase change.

  11. Quantification of physiological, movement, and technical outputs during a novel small-sided game in young team sport athletes.

    Science.gov (United States)

    Harrison, Craig B; Gill, Nicholas D; Kinugasa, Taisuke; Kilding, Andrew E

    2013-10-01

    The aim of this study was to quantify the physiological responses, time-motion characteristics, and technical executions associated with a novel non-sport-specific small-sided game (SSG) in young team sport players. On 6 separate occasions, 12 young male team sport athletes (mean ± SD: age, 13.0 ± 0.3 years; height, 157.4 ± 4.9 cm; body mass, 47.0 ± 5.0 kg; and V[Combining Dot Above]O2peak, 55.1 ± 4.6 ml·kg·min) completed various "bucketball" SSG formats (i.e., 3 vs. 3, 4 vs. 4, and 6 vs. 6) twice each. Heart rate (HR) was measured during each SSG at 5-second intervals. Time-motion characteristics were measured using global positioning systems. Ratings of perceived exertion (RPEs) were recorded immediately after the SSGs using the Borg scale (RPEs, 6-20). Technical skill executions were measured using a high-speed digital video camera. Analysis revealed a tendency for the 3 vs. 3 games to elicit higher HRs (88.3 ± 4.3) than either 4 vs. 4 (85.9 ± 4.9) or 6 vs. 6 formats (85.9 ± 3.2). Total distance traveled at 13-17.9 km·h was more during 6 vs. 6 than 3 vs. 3 games (very likely substantial true difference, 97%), and total possessions and number of catches, passes, and shots were all higher in 3 vs. 3 compared with 4 vs. 4 and 6 vs. 6 games. There was no difference in RPE between the game formats. The results of this study indicate that 3 vs. 3 non-sport-specific SSGs provide higher stimulus for aerobic fitness adaptation and technical improvement than 4 vs. 4 and 6 vs. 6 formats, and their use for training young team sport athletes is recommended.

  12. A minimal limit-cycle model to profile movement patterns of individuals during agility drill performance: Effects of skill level.

    Science.gov (United States)

    Mehdizadeh, Sina; Arshi, Ahmed Reza; Davids, Keith

    2015-06-01

    Identification of control strategies during agility performance is significant in understanding movement behavior. This study aimed at providing a fundamental mathematical model for describing the motion of participants during an agility drill and to determine whether skill level constrained model components. Motion patterns of two groups of skilled and unskilled participants (n=8 in each) during performance of a forward/backward agility drill modeled as limit-cycles. Participant movements were recorded by motion capture of a reflective marker attached to the sacrum of each individual. Graphical and regression analyses of movement kinematics in Hooke's plane, phase plane and velocity profile were performed to determine components of the models. Results showed that the models of both skilled and unskilled groups had terms from Duffing stiffness as well as Van der Pol damping oscillators. Data also indicated that the proposed models captured on average 97% of the variance for both skilled and unskilled groups. Findings from this study revealed the movement patterning associated with skilled and unskilled performance in a typical forward/backward agility drill which might be helpful for trainers and physiotherapists in enhancing agility. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Numerical Modeling of Oil Spill Movement along North-West Coast of India Using GNOME

    Directory of Open Access Journals (Sweden)

    R Remyalekshmi

    2013-03-01

    Full Text Available India is located at a very strategic point with respect to the international commercial sea routes with a large amount of crude oil traffic. Hence, the risk of oil spill occurring in the Indian waters is considerably high. In the present paper, forecasting the movement of a possible crude oil spill of 10,000 barrels at a location of latitude 21° 41′ 48.53′ N and longitude 66° 46′ 41.45″ E, intersection point of two ship routes from Kandla port and Bombay port (Kandla port of India to Yanbu port of Saudi Arabia and Bombay port of India to Ras Tanura port of Saudi Arabia has been carried out using GNOME (General NOAA Operational Modeling Environment model developed by Hazardous Materials Response Division (HAZMAT of the National Oceanic and Atmospheric Administration Office of Response and Restoration (NOAA OR&R of United States government. The governing equations for horizontal diffusion, evaporation, dissolution, dispersion etc, adopted by GNOME have been presented in the paper. The simulation is carried out for month of September 2011. It is found that the spill possibly takes 10 hours to reach Gujarat coast and 15 hours to reach Maharashtra coast. With this available knowledge, appropriate mitigation measures may be adopted before spill reaches the shores.

  14. Computer-aided pulmonary image analysis in small animal models

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ziyue; Mansoor, Awais; Mollura, Daniel J. [Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, National Institutes of Health (NIH), Bethesda, Maryland 32892 (United States); Bagci, Ulas, E-mail: ulasbagci@gmail.com [Center for Research in Computer Vision (CRCV), University of Central Florida (UCF), Orlando, Florida 32816 (United States); Kramer-Marek, Gabriela [The Institute of Cancer Research, London SW7 3RP (United Kingdom); Luna, Brian [Microfluidic Laboratory Automation, University of California-Irvine, Irvine, California 92697-2715 (United States); Kubler, Andre [Department of Medicine, Imperial College London, London SW7 2AZ (United Kingdom); Dey, Bappaditya; Jain, Sanjay [Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 (United States); Foster, Brent [Department of Biomedical Engineering, University of California-Davis, Davis, California 95817 (United States); Papadakis, Georgios Z. [Radiology and Imaging Sciences, National Institutes of Health (NIH), Bethesda, Maryland 32892 (United States); Camp, Jeremy V. [Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky 40202 (United States); Jonsson, Colleen B. [National Institute for Mathematical and Biological Synthesis, University of Tennessee, Knoxville, Tennessee 37996 (United States); Bishai, William R. [Howard Hughes Medical Institute, Chevy Chase, Maryland 20815 and Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 (United States); Udupa, Jayaram K. [Medical Image Processing Group, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2015-07-15

    Purpose: To develop an automated pulmonary image analysis framework for infectious lung diseases in small animal models. Methods: The authors describe a novel pathological lung and airway segmentation method for small animals. The proposed framework includes identification of abnormal imaging patterns pertaining to infectious lung diseases. First, the authors’ system estimates an expected lung volume by utilizing a regression function between total lung capacity and approximated rib cage volume. A significant difference between the expected lung volume and the initial lung segmentation indicates the presence of severe pathology, and invokes a machine learning based abnormal imaging pattern detection system next. The final stage of the proposed framework is the automatic extraction of airway tree for which new affinity relationships within the fuzzy connectedness image segmentation framework are proposed by combining Hessian and gray-scale morphological reconstruction filters. Results: 133 CT scans were collected from four different studies encompassing a wide spectrum of pulmonary abnormalities pertaining to two commonly used small animal models (ferret and rabbit). Sensitivity and specificity were greater than 90% for pathological lung segmentation (average dice similarity coefficient > 0.9). While qualitative visual assessments of airway tree extraction were performed by the participating expert radiologists, for quantitative evaluation the authors validated the proposed airway extraction method by using publicly available EXACT’09 data set. Conclusions: The authors developed a comprehensive computer-aided pulmonary image analysis framework for preclinical research applications. The proposed framework consists of automatic pathological lung segmentation and accurate airway tree extraction. The framework has high sensitivity and specificity; therefore, it can contribute advances in preclinical research in pulmonary diseases.

  15. Comparing interval estimates for small sample ordinal CFA models.

    Science.gov (United States)

    Natesan, Prathiba

    2015-01-01

    Robust maximum likelihood (RML) and asymptotically generalized least squares (AGLS) methods have been recommended for fitting ordinal structural equation models. Studies show that some of these methods underestimate standard errors. However, these studies have not investigated the coverage and bias of interval estimates. An estimate with a reasonable standard error could still be severely biased. This can only be known by systematically investigating the interval estimates. The present study compares Bayesian, RML, and AGLS interval estimates of factor correlations in ordinal confirmatory factor analysis models (CFA) for small sample data. Six sample sizes, 3 factor correlations, and 2 factor score distributions (multivariate normal and multivariate mildly skewed) were studied. Two Bayesian prior specifications, informative and relatively less informative were studied. Undercoverage of confidence intervals and underestimation of standard errors was common in non-Bayesian methods. Underestimated standard errors may lead to inflated Type-I error rates. Non-Bayesian intervals were more positive biased than negatively biased, that is, most intervals that did not contain the true value were greater than the true value. Some non-Bayesian methods had non-converging and inadmissible solutions for small samples and non-normal data. Bayesian empirical standard error estimates for informative and relatively less informative priors were closer to the average standard errors of the estimates. The coverage of Bayesian credibility intervals was closer to what was expected with overcoverage in a few cases. Although some Bayesian credibility intervals were wider, they reflected the nature of statistical uncertainty that comes with the data (e.g., small sample). Bayesian point estimates were also more accurate than non-Bayesian estimates. The results illustrate the importance of analyzing coverage and bias of interval estimates, and how ignoring interval estimates can be misleading

  16. Calculation modelling of the RCCA movement through bowed FA guide tubes

    International Nuclear Information System (INIS)

    Razoumovsky, D.V.; Lihkachev, Yu.I.; Troyanov, V.M.

    2000-01-01

    Rod control cluster assembly movement through the bowed guide tubes is considered. The movement equation is presented with some of the assumptions and special attention is paid to the determination of the mechanical friction force. The numerical algorithm is described and some results of parametric studies are presented. (author)

  17. Coordination Mechanism in Fast Human Movements. Experimental and Modelling Studies. Volume 2.

    Science.gov (United States)

    1983-09-01

    manipulating the pulse frequency did not seem to have any drastic effects. Therefore, muscular contractions ŕ-.W %: obtained from the stimulations...movement reeducation . More recently, a series of studies -f investigating the motor learning effects of functional electrical stimulation was realized...technique in order to manipulate movement performance. Therefore, such technique could see many usefull applications in the rehabilitation and reeducation

  18. Semi-analytical model of the axial movements of an oil-well drillstring in vertical wellbores

    Science.gov (United States)

    Hovda, Sigve

    2018-03-01

    A lumped element model for the axial movement of an oil-well drillstring is presented. In this paper, the model is restricted to vertical holes, where damping is due to skin friction from time dependent Newtonian annular Couette-Poiseuille flow. The drillstring is constructed of pipes with different diameters and the diameter of the hole varies as a function of depth. Under these assumptions, the axial movement anywhere in the drillstring is basically a convolution between the axial movement on the top and a semi-analytical function that is derived in this paper. Expressions are given for transfer functions for downhole movements and pressures (surge and swab). In a vertical drilling situation, the motion is clearly underdamped, even when the hole is tight. The semi-analytical model illuminates various factors that are shown to be important for describing downhole pressure and motion. In particular the effect of added mass, the steady state viscous forces, the Basset viscous forces and the distribution of pipe sizes in the hole. The latter have non-neglectable impacts on where the resonant frequencies are located, how much they are amplified and what happens to the downhole pressure. Together with statistical power spectra of ocean wave patterns and the response amplitude operators for a floating structure, this model illustrates design concerns related to heave motion and how fast one can run the drillstring into the hole. Moreover, because of the computational simplicity of computing the convolution, the model is well suited for a real-time implementation.

  19. Differentiated analysis of orthodontic tooth movement in rats with an improved rat model and three-dimensional imaging.

    Science.gov (United States)

    Kirschneck, Christian; Proff, Peter; Fanghaenel, Jochen; Behr, Michael; Wahlmann, Ulrich; Roemer, Piero

    2013-12-01

    Rat models currently available for analysis of orthodontic tooth movement often lack differentiated, reliable and precise measurement systems allowing researchers to separately investigate the individual contribution of tooth tipping, body translation and root torque to overall displacement. Many previously proposed models have serious limitations such as the rather inaccurate analysis of the effects of orthodontic forces on rat incisors. We therefore developed a differentiated measurement system that was used within a rat model with the aim of overcoming the limitations of previous studies. The first left upper molar and the upper incisors of 24 male Wistar rats were subjected to a constant orthodontic force of 0.25 N by means of a NiTi closed coil spring for up to four weeks. The extent of the various types of tooth movement was measured optometrically with a CCD microscope camera and cephalometrically by means of cone beam computed tomography (CBCT). Both types of measurement proved to be reliable for consecutive measurements and the significant tooth movement induced had no harmful effects on the animals. Movement kinetics corresponded to known physiological processes and tipping and body movement equally contributed to the tooth displacement. The upper incisors of the rats were significantly deformed and their natural eruption was effectively halted. The results showed that our proposed measurement systems used within a rat model resolved most of the inadequacies of previous studies. They are reliable, precise and physiological tools for the differentiated analysis of orthodontic tooth movement while simultaneously preserving animal welfare. Copyright © 2013 Elsevier GmbH. All rights reserved.

  20. Ultrasound Evaluation of the Combined Effects of Thoracolumbar Fascia Injury and Movement Restriction in a Porcine Model.

    Science.gov (United States)

    Bishop, James H; Fox, James R; Maple, Rhonda; Loretan, Caitlin; Badger, Gary J; Henry, Sharon M; Vizzard, Margaret A; Langevin, Helene M

    2016-01-01

    The persistence of back pain following acute back "sprains" is a serious public health problem with poorly understood pathophysiology. The recent finding that human subjects with chronic low back pain (LBP) have increased thickness and decreased mobility of the thoracolumbar fascia measured with ultrasound suggest that the fasciae of the back may be involved in LBP pathophysiology. This study used a porcine model to test the hypothesis that similar ultrasound findings can be produced experimentally in a porcine model by combining a local injury of fascia with movement restriction using a "hobble" device linking one foot to a chest harness for 8 weeks. Ultrasound measurements of thoracolumbar fascia thickness and shear plane mobility (shear strain) during passive hip flexion were made at the 8 week time point on the non-intervention side (injury and/or hobble). Injury alone caused both an increase in fascia thickness (p = .007) and a decrease in fascia shear strain on the non-injured side (p = .027). Movement restriction alone did not change fascia thickness but did decrease shear strain on the non-hobble side (p = .024). The combination of injury plus movement restriction had additive effects on reducing fascia mobility with a 52% reduction in shear strain compared with controls and a 28% reduction compared to movement restriction alone. These results suggest that a back injury involving fascia, even when healed, can affect the relative mobility of fascia layers away from the injured area, especially when movement is also restricted.

  1. Ultrasound Evaluation of the Combined Effects of Thoracolumbar Fascia Injury and Movement Restriction in a Porcine Model.

    Directory of Open Access Journals (Sweden)

    James H Bishop

    Full Text Available The persistence of back pain following acute back "sprains" is a serious public health problem with poorly understood pathophysiology. The recent finding that human subjects with chronic low back pain (LBP have increased thickness and decreased mobility of the thoracolumbar fascia measured with ultrasound suggest that the fasciae of the back may be involved in LBP pathophysiology. This study used a porcine model to test the hypothesis that similar ultrasound findings can be produced experimentally in a porcine model by combining a local injury of fascia with movement restriction using a "hobble" device linking one foot to a chest harness for 8 weeks. Ultrasound measurements of thoracolumbar fascia thickness and shear plane mobility (shear strain during passive hip flexion were made at the 8 week time point on the non-intervention side (injury and/or hobble. Injury alone caused both an increase in fascia thickness (p = .007 and a decrease in fascia shear strain on the non-injured side (p = .027. Movement restriction alone did not change fascia thickness but did decrease shear strain on the non-hobble side (p = .024. The combination of injury plus movement restriction had additive effects on reducing fascia mobility with a 52% reduction in shear strain compared with controls and a 28% reduction compared to movement restriction alone. These results suggest that a back injury involving fascia, even when healed, can affect the relative mobility of fascia layers away from the injured area, especially when movement is also restricted.

  2. Fiberotomy enhances orthodontic tooth movement and diminishes relapse in a rat model.

    Science.gov (United States)

    Young, L; Binderman, I; Yaffe, A; Beni, L; Vardimon, A D

    2013-08-01

    Accelerated orthodontic tooth movement is triggered by procedures that include mucoperiosteum flap surgery and surgical scarring of cortical bone. Our aim was to test whether fiberotomy by itself will accelerate orthodontic tooth movement and diminish relapse. In 34 Wistar rats, alveolar bone resorption and molar tooth movement were measured after fiberotomy, apical full-thickness flap without detachment of gingiva from the roots, or no surgery. Orthodontic appliance was installed at time of surgery and activated for 14 days, generating movement of the first maxillary molar buccal and then removed. Percent of sections in which alveolar bone resorption was detected was significantly higher (p accelerated orthodontic tooth movement and diminished relapse. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Systems analysis of the vestibulo-ocular system. [mathematical model of vestibularly driven head and eye movements

    Science.gov (United States)

    Schmid, R. M.

    1973-01-01

    The vestibulo-ocular system is examined from the standpoint of system theory. The evolution of a mathematical model of the vestibulo-ocular system in an attempt to match more and more experimental data is followed step by step. The final model explains many characteristics of the eye movement in vestibularly induced nystagmus. The analysis of the dynamic behavior of the model at the different stages of its development is illustrated in time domain, mainly in a qualitative way.

  4. Modelling soil carbon movement by erosion over large scales and long time periods

    Science.gov (United States)

    Quinton, John; Davies, Jessica; Tipping, Ed

    2014-05-01

    Agricultural intensification accelerates physical erosion rates and the transport of carbon within the landscape. In order to improve understanding of how past, present and future anthropogenic land-use change has and will influence carbon and nutrient cycling, it is necessary to develop quantitative tools that can predict soil erosion and carbon movement at large temporal and spatial scales, that are consistent with the time constants of biogeochemical processes and the spatial scales of land-use change and natural resources. However, representing erosion and its impact on the carbon cycle over large spatial scales and long time periods is challenging. Erosion and sediment transport processes operate at multiple spatial and temporal scales with splash erosion dominating at the sub-plot scale and occurring within seconds, up to gully formation operating at field-catchment scales over days to months. In addition, most erosion production observations are made at the experimental plot scale, where fine time scales and detailed processes dominate. This is coupled with complexities associated with carbon detachment, decomposition and uncertainties surrounding carbon burial rates and stability - all of which occur over widely different temporal and spatial scales. As such, these data cannot be simply scaled to inform erosion and carbon representation at the regional scale, where topography, vegetation cover and landscape organisation become more important controls on sediment fluxes. We have developed a simple energy-based regional scale method of soil erosion modelling, which is integration into a hydro-biogeochemical model that will simulate carbon, nitrogen and phosphorus pools and fluxes across the UK from the industrial revolution to the present day. The model is driven by overland flow, dynamic vegetation cover, soil properties, and topographic distributions and produces sediment production and yield at the 5km grid scale. In this paper we will introduce the

  5. Muscle Sensor Model Using Small Scale Optical Device for Pattern Recognitions

    Directory of Open Access Journals (Sweden)

    Kreangsak Tamee

    2013-01-01

    Full Text Available A new sensor system for measuring contraction and relaxation of muscles by using a PANDA ring resonator is proposed. The small scale optical device is designed and configured to perform the coupling effects between the changes in optical device phase shift and human facial muscle movement, which can be used to form the relationship between optical phase shift and muscle movement. By using the Optiwave and MATLAB programs, the results obtained have shown that the measurement of the contraction and relaxation of muscles can be obtained after the muscle movements, in which the unique pattern of individual muscle movement from facial expression can be established. The obtained simulation results, that is, interference signal patterns, can be used to form the various pattern recognitions, which are useful for the human machine interface and the human computer interface application and discussed in detail.

  6. Soybean yield modeling using bootstrap methods for small samples

    Energy Technology Data Exchange (ETDEWEB)

    Dalposso, G.A.; Uribe-Opazo, M.A.; Johann, J.A.

    2016-11-01

    One of the problems that occur when working with regression models is regarding the sample size; once the statistical methods used in inferential analyzes are asymptotic if the sample is small the analysis may be compromised because the estimates will be biased. An alternative is to use the bootstrap methodology, which in its non-parametric version does not need to guess or know the probability distribution that generated the original sample. In this work we used a set of soybean yield data and physical and chemical soil properties formed with fewer samples to determine a multiple linear regression model. Bootstrap methods were used for variable selection, identification of influential points and for determination of confidence intervals of the model parameters. The results showed that the bootstrap methods enabled us to select the physical and chemical soil properties, which were significant in the construction of the soybean yield regression model, construct the confidence intervals of the parameters and identify the points that had great influence on the estimated parameters. (Author)

  7. Digestion of starch in a dynamic small intestinal model.

    Science.gov (United States)

    Jaime-Fonseca, M R; Gouseti, O; Fryer, P J; Wickham, M S J; Bakalis, S

    2016-12-01

    The rate and extent of starch digestion have been linked with important health aspects, such as control of obesity and type-2 diabetes. In vitro techniques are often used to study digestion and simulated nutrient absorption; however, the effect of gut motility is often disregarded. The present work aims at studying fundamentals of starch digestion, e.g. the effect of viscosity on digestibility, taking into account both biochemical and engineering (gut motility) parameters. New small intestinal model (SIM) that realistically mimics gut motility (segmentation) was used to study digestibility and simulated oligosaccharide bio accessibility of (a) model starch solutions; (b) bread formulations. First, the model was compared with the rigorously mixed stirred tank reactor (STR). Then the effects of enzyme concentration/flow rate, starch concentration, and digesta viscosity (addition of guar gum) were evaluated. Compared to the STR, the SIM showed presence of lag phase when no digestive processes could be detected. The effects of enzyme concentration and flow rate appeared to be marginal in the region of mass transfer limited reactions. Addition of guar gum reduced simulated glucose absorption by up to 45 % in model starch solutions and by 35 % in bread formulations, indicating the importance of chyme rheology on nutrient bioaccessibility. Overall, the work highlights the significance of gut motility in digestive processes and offers a powerful tool in nutritional studies that, additionally to biochemical, considers engineering aspects of digestion. The potential to modulate food digestibility and nutrient bioaccessibility by altering food formulation is indicated.

  8. Heterogeneous movement of insectivorous Amazonian birds through primary and secondary forest: A case study using multistate models with radiotelemetry data

    Science.gov (United States)

    Luke L. Powell; Jared D. Wolfe; Erik I. Johnson; James E. Hines; James D. Nichols; Philip C Stouffer

    2015-01-01

    Given rates of deforestation, disturbance, and secondary forest accumulation in tropical rainforests, there is a great need to quantify habitat use and movement among different habitats. This need is particularly pronounced for animals most sensitive to disturbance, such as insectivorous understory birds. Here we use multistate capture–recapture models with...

  9. High-speed video gait analysis reveals early and characteristic locomotor phenotypes in mouse models of neurodegenerative movement disorders.

    Science.gov (United States)

    Preisig, Daniel F; Kulic, Luka; Krüger, Maik; Wirth, Fabian; McAfoose, Jordan; Späni, Claudia; Gantenbein, Pascal; Derungs, Rebecca; Nitsch, Roger M; Welt, Tobias

    2016-09-15

    Neurodegenerative diseases of the central nervous system frequently affect the locomotor system resulting in impaired movement and gait. In this study we performed a whole-body high-speed video gait analysis in three different mouse lines of neurodegenerative movement disorders to investigate the motor phenotype. Based on precise computerized motion tracking of all relevant joints and the tail, a custom-developed algorithm generated individual and comprehensive locomotor profiles consisting of 164 spatial and temporal parameters. Gait changes observed in the three models corresponded closely to the classical clinical symptoms described in these disorders: Muscle atrophy due to motor neuron loss in SOD1 G93A transgenic mice led to gait characterized by changes in hind-limb movement and positioning. In contrast, locomotion in huntingtin N171-82Q mice modeling Huntington's disease with basal ganglia damage was defined by hyperkinetic limb movements and rigidity of the trunk. Harlequin mutant mice modeling cerebellar degeneration showed gait instability and extensive changes in limb positioning. Moreover, model specific gait parameters were identified and were shown to be more sensitive than conventional motor tests. Altogether, this technique provides new opportunities to decipher underlying disease mechanisms and test novel therapeutic approaches. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. CFD model of air movement in ventilated facade: comparison between natural and forced air flow

    Energy Technology Data Exchange (ETDEWEB)

    Mora Perez, Miguel; Lopez Patino, Gonzalo; Lopez Jimenez, P. Amparo [Hydraulic and Environmental Engineering Department, Universitat Politècnica de Valencia (Spain)

    2013-07-01

    This study describes computational fluid dynamics (CFD) modeling of ventilated facade. Ventilated facades are normal facade but it has an extra channel between the concrete wall and the (double skin) facade. Several studies found in the literature are carried out with CFD simulations about the behavior of the thermodynamic phenomena of the double skin facades systems. These studies conclude that the presence of the air gap in the ventilated facade affects the temperature in the building skin, causing a cooling effect, at least in low-rise buildings. One of the most important factors affecting the thermal effects of ventilated facades is the wind velocity. In this contribution, a CFD analysis applied on two different velocity assumptions for air movement in the air gap of a ventilated facade is presented. A comparison is proposed considering natural wind induced velocity with forced fan induced velocity in the gap. Finally, comparing temperatures in the building skin, the differences between both solutions are described determining that, related to the considered boundary conditions, there is a maximum height in which the thermal effect of the induced flow is significantly observed.

  11. Small-scale engagement model with arrivals: analytical solutions

    International Nuclear Information System (INIS)

    Engi, D.

    1977-04-01

    This report presents an analytical model of small-scale battles. The specific impetus for this effort was provided by a need to characterize hypothetical battles between guards at a nuclear facility and their potential adversaries. The solution procedure can be used to find measures of a number of critical parameters; for example, the win probabilities and the expected duration of the battle. Numerical solutions are obtainable if the total number of individual combatants on the opposing sides is less than 10. For smaller force size battles, with one or two combatants on each side, symbolic solutions can be found. The symbolic solutions express the output parameters abstractly in terms of symbolic representations of the input parameters while the numerical solutions are expressed as numerical values. The input parameters are derived from the probability distributions of the attrition and arrival processes. The solution procedure reduces to solving sets of linear equations that have been constructed from the input parameters. The approach presented in this report does not address the problems associated with measuring the inputs. Rather, this report attempts to establish a relatively simple structure within which small-scale battles can be studied

  12. Small Area Model-Based Estimators Using Big Data Sources

    Directory of Open Access Journals (Sweden)

    Marchetti Stefano

    2015-06-01

    Full Text Available The timely, accurate monitoring of social indicators, such as poverty or inequality, on a finegrained spatial and temporal scale is a crucial tool for understanding social phenomena and policymaking, but poses a great challenge to official statistics. This article argues that an interdisciplinary approach, combining the body of statistical research in small area estimation with the body of research in social data mining based on Big Data, can provide novel means to tackle this problem successfully. Big Data derived from the digital crumbs that humans leave behind in their daily activities are in fact providing ever more accurate proxies of social life. Social data mining from these data, coupled with advanced model-based techniques for fine-grained estimates, have the potential to provide a novel microscope through which to view and understand social complexity. This article suggests three ways to use Big Data together with small area estimation techniques, and shows how Big Data has the potential to mirror aspects of well-being and other socioeconomic phenomena.

  13. Extracting Small and Long-Wavelength Vertical Land Surface Movements from an InSAR Time Series: The Case of Glacial Isostatic Adjustment in Scotland

    Science.gov (United States)

    Stockamp, J.; Li, Z.

    2016-12-01

    Understanding the effects of Glacial Isostatic Adjustment (GIA) in Scotland is essential for the assessment of past and future sea-level trends around the coast. Against the backdrop of climate change and the global rise of sea-levels, the question arises as to what are the modern rate and spatial distribution of GIA-related crustal uplift in Scotland. Differential SAR Interferometry (D-InSAR) is an established technique for analysing crustal motion and land surface deformation caused by co- and interseismic processes, volcanic activity, landslides or subsidence. When it comes to the detection of small, long-wavelength displacements, such as GIA-induced vertical land movement, the application of D-InSAR becomes challenging and a very high quality standard in terms of precision and accuracy is necessary to make it a competitive tool to established geodetic techniques, such as GNSS. This study investigates the applicability of a D-InSAR time series technique, the Small Baseline approach, in its ability to determine recent rates of vertical land movement in Scotland with a high accuracy and precision (in the mm/yr level) and on a broader spatial scale than conventional geodetic techniques that rely on spatial interpolation. A range of error signals (atmospheric water vapour, orbital ramps, temporal decorrelation, topographic artefacts etc.) require to be addressed before the extraction of any uplift signal is possible. This includes the advancement of error correction techniques for such artefacts within the time series inversion processing chain. To reduce orbit errors in the interferograms, an improved network correction technique, that incorporates phase loop triplets of interferograms into the observation equations, has been tested with good results. In addition, further methods are being explored for the separation of the desired deformation signal from residual orbital and atmospheric errors, such as Principal Component Analysis and Independent Component

  14. A Comprehensive Mixture of Tobacco Smoke Components Retards Orthodontic Tooth Movement via the Inhibition of Osteoclastogenesis in a Rat Model

    Directory of Open Access Journals (Sweden)

    Maya Nagaie

    2014-10-01

    Full Text Available Tobacco smoke is a complex mixture of numerous components. Nevertheless, most experiments have examined the effects of individual chemicals in tobacco smoke. The comprehensive effects of components on tooth movement and bone resorption remain unexplored. Here, we have shown that a comprehensive mixture of tobacco smoke components (TSCs attenuated bone resorption through osteoclastogenesis inhibition, thereby retarding experimental tooth movement in a rat model. An elastic power chain (PC inserted between the first and second maxillary molars robustly yielded experimental tooth movement within 10 days. TSC administration effectively retarded tooth movement since day 4. Histological evaluation disclosed that tooth movement induced bone resorption at two sites: in the bone marrow and the peripheral bone near the root. TSC administration significantly reduced the number of tartrate-resistant acid phosphatase (TRAP-positive osteoclastic cells in the bone marrow cavity of the PC-treated dentition. An in vitro study indicated that the inhibitory effects of TSCs on osteoclastogenesis seemed directed more toward preosteoclasts than osteoblasts. These results indicate that the comprehensive mixture of TSCs might be a useful tool for detailed verification of the adverse effects of tobacco smoke, possibly contributing to the development of reliable treatments in various fields associated with bone resorption.

  15. A comprehensive mixture of tobacco smoke components retards orthodontic tooth movement via the inhibition of osteoclastogenesis in a rat model.

    Science.gov (United States)

    Nagaie, Maya; Nishiura, Aki; Honda, Yoshitomo; Fujiwara, Shin-Ichi; Matsumoto, Naoyuki

    2014-10-15

    Tobacco smoke is a complex mixture of numerous components. Nevertheless, most experiments have examined the effects of individual chemicals in tobacco smoke. The comprehensive effects of components on tooth movement and bone resorption remain unexplored. Here, we have shown that a comprehensive mixture of tobacco smoke components (TSCs) attenuated bone resorption through osteoclastogenesis inhibition, thereby retarding experimental tooth movement in a rat model. An elastic power chain (PC) inserted between the first and second maxillary molars robustly yielded experimental tooth movement within 10 days. TSC administration effectively retarded tooth movement since day 4. Histological evaluation disclosed that tooth movement induced bone resorption at two sites: in the bone marrow and the peripheral bone near the root. TSC administration significantly reduced the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclastic cells in the bone marrow cavity of the PC-treated dentition. An in vitro study indicated that the inhibitory effects of TSCs on osteoclastogenesis seemed directed more toward preosteoclasts than osteoblasts. These results indicate that the comprehensive mixture of TSCs might be a useful tool for detailed verification of the adverse effects of tobacco smoke, possibly contributing to the development of reliable treatments in various fields associated with bone resorption.

  16. ICT evaluation models and performance of medium and small enterprises

    Directory of Open Access Journals (Sweden)

    Bayaga Anass

    2014-01-01

    Full Text Available Building on prior research related to (1 impact of information communication technology (ICT and (2 operational risk management (ORM in the context of medium and small enterprises (MSEs, the focus of this study was to investigate the relationship between (1 ICT operational risk management (ORM and (2 performances of MSEs. To achieve the focus, the research investigated evaluating models for understanding the value of ICT ORM in MSEs. Multiple regression, Repeated-Measures Analysis of Variance (RM-ANOVA and Repeated-Measures Multivariate Analysis of Variance (RM-MANOVA were performed. The findings of the distribution revealed that only one variable made a significant percentage contribution to the level of ICT operation in MSEs, the Payback method (β = 0.410, p < .000. It may thus be inferred that the Payback method is the prominent variable, explaining the variation in level of evaluation models affecting ICT adoption within MSEs. Conclusively, in answering the two questions (1 degree of variability explained and (2 predictors, the results revealed that the variable contributed approximately 88.4% of the variations in evaluation models affecting ICT adoption within MSEs. The analysis of variance also revealed that the regression coefficients were real and did not occur by chance

  17. Simple Electromagnetic Modeling of Small Airplanes: Neural Network Approach

    Directory of Open Access Journals (Sweden)

    P. Tobola

    2009-04-01

    Full Text Available The paper deals with the development of simple electromagnetic models of small airplanes, which can contain composite materials in their construction. Electromagnetic waves can penetrate through the surface of the aircraft due to the specific electromagnetic properties of the composite materials, which can increase the intensity of fields inside the airplane and can negatively influence the functionality of the sensitive avionics. The airplane is simulated by two parallel dielectric layers (the left-hand side wall and the right-hand side wall of the airplane. The layers are put into a rectangular metallic waveguide terminated by the absorber in order to simulate the illumination of the airplane by the external wave (both of the harmonic nature and pulse one. Thanks to the simplicity of the model, the parametric analysis can be performed, and the results can be used in order to train an artificial neural network. The trained networks excel in further reduction of CPU-time demands of an airplane modeling.

  18. SIMPLIFIED MATHEMATICAL MODEL OF SMALL SIZED UNMANNED AIRCRAFT VEHICLE LAYOUT

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available Strong reduction of new aircraft design period using new technology based on artificial intelligence is the key problem mentioned in forecasts of leading aerospace industry research centers. This article covers the approach to devel- opment of quick aerodynamic design methods based on artificial intelligence neural system. The problem is being solved for the classical scheme of small sized unmanned aircraft vehicle (UAV. The principal parts of the method are the mathe- matical model of layout, layout generator of this type of aircraft is built on aircraft neural networks, automatic selection module for cleaning variety of layouts generated in automatic mode, robust direct computational fluid dynamics method, aerodynamic characteristics approximators on artificial neural networks.Methods based on artificial neural networks have intermediate position between computational fluid dynamics methods or experiments and simplified engineering approaches. The use of ANN for estimating aerodynamic characteris-tics put limitations on input data. For this task the layout must be presented as a vector with dimension not exceeding sev-eral hundred. Vector components must include all main parameters conventionally used for layouts description and com- pletely replicate the most important aerodynamics and structural properties.The first stage of the work is presented in the paper. Simplified mathematical model of small sized UAV was developed. To estimate the range of geometrical parameters of layouts the review of existing vehicle was done. The result of the work is the algorithm and computer software for generating the layouts based on ANN technolo-gy. 10000 samples were generated and the dataset containig geometrical and aerodynamic characteristics of layoutwas created.

  19. Volitional and Real-Time Control Cursor Based on Eye Movement Decoding Using a Linear Decoding Model

    Directory of Open Access Journals (Sweden)

    Jinhua Zhang

    2016-01-01

    Full Text Available The aim of this study is to build a linear decoding model that reveals the relationship between the movement information and the EOG (electrooculogram data to online control a cursor continuously with blinks and eye pursuit movements. First of all, a blink detection method is proposed to reject a voluntary single eye blink or double-blink information from EOG. Then, a linear decoding model of time series is developed to predict the position of gaze, and the model parameters are calibrated by the RLS (Recursive Least Square algorithm; besides, the assessment of decoding accuracy is assessed through cross-validation procedure. Additionally, the subsection processing, increment control, and online calibration are presented to realize the online control. Finally, the technology is applied to the volitional and online control of a cursor to hit the multiple predefined targets. Experimental results show that the blink detection algorithm performs well with the voluntary blink detection rate over 95%. Through combining the merits of blinks and smooth pursuit movements, the movement information of eyes can be decoded in good conformity with the average Pearson correlation coefficient which is up to 0.9592, and all signal-to-noise ratios are greater than 0. The novel system allows people to successfully and economically control a cursor online with a hit rate of 98%.

  20. Modeling vertical movement of organic matter in a soil incubated for 41 years with "1"4C labeled straw

    DEFF Research Database (Denmark)

    Bruun, S.; Christensen, B.T.; Thomsen, I.K.

    2007-01-01

    The distribution of organic matter (OM) in the soil profile reflects the balance between inputs and decomposition at different depths as well as transport of OM within the profile. In this study we modeled movement of OM in the soil profile as a result of mechanisms resulting in dispersive...... and advective movement. The model was used to interpret the distribution of C-14 in the soil profile 41 years after the labeling event. The model fitted the observed distribution of C-14 well (R-2 = 0.988, AIC(c) = -82.6), with a dispersion constant of D = 0.71 cm(2) yr(-1) and an advection constant of v = 0.......0081 cm yr(-1). However, the model consistently underestimated the amount of OM in the soil layers from 27 to 37 cm depth. A possible explanation for this is that different fractions of OM are transported by different mechanisms. For example, particulate OM, organomineral colloids and dissolved OM...

  1. Effect of human movement on airborne disease transmission in an airplane cabin: study using numerical modeling and quantitative risk analysis.

    Science.gov (United States)

    Han, Zhuyang; To, Gin Nam Sze; Fu, Sau Chung; Chao, Christopher Yu-Hang; Weng, Wenguo; Huang, Quanyi

    2014-08-06

    Airborne transmission of respiratory infectious disease in indoor environment (e.g. airplane cabin, conference room, hospital, isolated room and inpatient ward) may cause outbreaks of infectious diseases, which may lead to many infection cases and significantly influences on the public health. This issue has received more and more attentions from academics. This work investigates the influence of human movement on the airborne transmission of respiratory infectious diseases in an airplane cabin by using an accurate human model in numerical simulation and comparing the influences of different human movement behaviors on disease transmission. The Eulerian-Lagrangian approach is adopted to simulate the dispersion and deposition of the expiratory aerosols. The dose-response model is used to assess the infection risks of the occupants. The likelihood analysis is performed as a hypothesis test on the input parameters and different human movement pattern assumptions. An in-flight SARS outbreak case is used for investigation. A moving person with different moving speeds is simulated to represent the movement behaviors. A digital human model was used to represent the detailed profile of the occupants, which was obtained by scanning a real thermal manikin using the 3D laser scanning system. The analysis results indicate that human movement can strengthen the downward transport of the aerosols, significantly reduce the overall deposition and removal rate of the suspended aerosols and increase the average infection risk in the cabin. The likelihood estimation result shows that the risk assessment results better fit the outcome of the outbreak case when the movements of the seated passengers are considered. The intake fraction of the moving person is significantly higher than most of the seated passengers. The infection risk distribution in the airplane cabin highly depends on the movement behaviors of the passengers and the index patient. The walking activities of the crew

  2. Modelling transition states of a small once-through boiler

    Energy Technology Data Exchange (ETDEWEB)

    Talonpoika, T. [Lappeenranta Univ. of Technology (Finland). Dept. of Energy Technology

    1997-12-31

    the model gives results that are logical in the directions of the charges, and the order of magnitude of the time scale of charges is also as expected. The results of the tests on the process fluid side show that the model gives reasonable results both on temperature charges that cause small alterations in the process state and on mass flow rate charges causing very great alterations. The test runs show that the dynamic model has no problems in calculating cases in which the temperature of the entering heat source suddenly goes below that of the tube wall or the process fluid. (author) 7 refs.

  3. Validity of a small low-cost triaxial accelerometer with integrated logger for uncomplicated measurements of postures and movements of head, upper back and upper arms.

    Science.gov (United States)

    Dahlqvist, Camilla; Hansson, Gert-Åke; Forsman, Mikael

    2016-07-01

    Repetitive work and work in constrained postures are risk factors for developing musculoskeletal disorders. Low-cost, user-friendly technical methods to quantify these risks are needed. The aims were to validate inclination angles and velocities of one model of the new generation of accelerometers with integrated data loggers against a previously validated one, and to compare meaurements when using a plain reference posture with that of a standardized one. All mean (n = 12 subjects) angular RMS-differences in 4 work tasks and 4 body parts were movements during work. Further work is needed for validation of the plain reference posture for upper arms. Copyright © 2016 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  4. Modelling hourly rates of evaporation from small lakes

    Directory of Open Access Journals (Sweden)

    R. J. Granger

    2011-01-01

    Full Text Available The paper presents the results of a field study of open water evaporation carried out on three small lakes in Western and Northern Canada. In this case small lakes are defined as those for which the temperature above the water surface is governed by the upwind land surface conditions; that is, a continuous boundary layer exists over the lake, and large-scale atmospheric effects such as entrainment do not come into play. Lake evaporation was measured directly using eddy covariance equipment; profiles of wind speed, air temperature and humidity were also obtained over the water surfaces. Observations were made as well over the upwind land surface.

    The major factors controlling open water evaporation were examined. The study showed that for time periods shorter than daily, the open water evaporation bears no relationship to the net radiation; the wind speed is the most significant factor governing the evaporation rates, followed by the land-water temperature contrast and the land-water vapour pressure contrast. The effect of the stability on the wind field was demonstrated; relationships were developed relating the land-water wind speed contrast to the land-water temperature contrast. The open water period can be separated into two distinct evaporative regimes: the warming period in the Spring, when the land is warmer than the water, the turbulent fluxes over water are suppressed; and the cooling period, when the water is warmer than the land, the turbulent fluxes over water are enhanced.

    Relationships were developed between the hourly rates of lake evaporation and the following significant variables and parameters (wind speed, land-lake temperature and humidity contrasts, and the downwind distance from shore. The result is a relatively simple versatile model for estimating the hourly lake evaporation rates. The model was tested using two independent data sets. Results show that the modelled evaporation follows the observed values

  5. The mathematics of movement

    Science.gov (United States)

    Johnson, D.H.

    1999-01-01

    Review of: Quantitative Analysis of Movement: Measuring and Modeling Population Redistribution in Animals and Plants. Peter Turchin. 1998. Sinauer Associates, Sunderland, MA. 306 pages. $38.95 (paper).

  6. Extended Fitts' model of pointing time in eye-gaze input system - Incorporating effects of target shape and movement direction into modeling.

    Science.gov (United States)

    Murata, Atsuo; Fukunaga, Daichi

    2018-04-01

    This study attempted to investigate the effects of the target shape and the movement direction on the pointing time using an eye-gaze input system and extend Fitts' model so that these factors are incorporated into the model and the predictive power of Fitts' model is enhanced. The target shape, the target size, the movement distance, and the direction of target presentation were set as within-subject experimental variables. The target shape included: a circle, and rectangles with an aspect ratio of 1:1, 1:2, 1:3, and 1:4. The movement direction included eight directions: upper, lower, left, right, upper left, upper right, lower left, and lower right. On the basis of the data for identifying the effects of the target shape and the movement direction on the pointing time, an attempt was made to develop a generalized and extended Fitts' model that took into account the movement direction and the target shape. As a result, the generalized and extended model was found to fit better to the experimental data, and be more effective for predicting the pointing time for a variety of human-computer interaction (HCI) task using an eye-gaze input system. Copyright © 2017. Published by Elsevier Ltd.

  7. Using Wearable Sensors and Machine Learning Models to Separate Functional Upper Extremity Use From Walking-Associated Arm Movements.

    Science.gov (United States)

    McLeod, Adam; Bochniewicz, Elaine M; Lum, Peter S; Holley, Rahsaan J; Emmer, Geoff; Dromerick, Alexander W

    2016-02-01

    To improve measurement of upper extremity (UE) use in the community by evaluating the feasibility of using body-worn sensor data and machine learning models to distinguish productive prehensile and bimanual UE activity use from extraneous movements associated with walking. Comparison of machine learning classification models with criterion standard of manually scored videos of performance in UE prosthesis users. Rehabilitation hospital training apartment. Convenience sample of UE prosthesis users (n=5) and controls (n=13) similar in age and hand dominance (N=18). Participants were filmed executing a series of functional activities; a trained observer annotated each frame to indicate either UE movement directed at functional activity or walking. Synchronized data from an inertial sensor attached to the dominant wrist were similarly classified as indicating either a functional use or walking. These data were used to train 3 classification models to predict the functional versus walking state given the associated sensor information. Models were trained over 4 trials: on UE amputees and controls and both within subject and across subject. Model performance was also examined with and without preprocessing (centering) in the across-subject trials. Percent correct classification. With the exception of the amputee/across-subject trial, at least 1 model classified >95% of test data correctly for all trial types. The top performer in the amputee/across-subject trial classified 85% of test examples correctly. We have demonstrated that computationally lightweight classification models can use inertial data collected from wrist-worn sensors to reliably distinguish prosthetic UE movements during functional use from walking-associated movement. This approach has promise in objectively measuring real-world UE use of prosthetic limbs and may be helpful in clinical trials and in measuring response to treatment of other UE pathologies. Copyright © 2016 American Congress of

  8. Eye movement control in reading: accounting for initial fixation locations and refixations within the E-Z Reader model.

    Science.gov (United States)

    Reichle, E D; Rayner, K; Pollatsek, A

    1999-10-01

    Reilly and O'Regan (1998, Vision Research, 38, 303-317) used computer simulations to evaluate how well several different word-targeting strategies could account for results which show that the distributions of fixation locations in reading are systematically related to low-level oculomotor variables, such as saccade distance and launch site [McConkie, Kerr, Reddix & Zola, (1988). Vision Research, 28, 1107-1118]. Their simulation results suggested that fixation locations are primarily determined by word length information, and that the processing of language, such as the identification of words, plays only a minimal role in deciding where to move the eyes. This claim appears to be problematic for our model of eye movement control in reading, E-Z Reader [Rayner, Reichle & Pollatsek (1998). Eye movement control in reading: an overview and model. In G. Underwood, Eye guidance in reading and scene perception (pp. 243-268). Oxford, UK: Elsevier; Reichle, Pollatsek, Fisher & Rayner (1998). Psychological Review, 105, 125-157], because it assumes that lexical access is the engine that drives the eyes forward during reading. However, we show that a newer version of E-Z Reader which still assumes that lexical access is the engine driving eye movements also predicts the locations of fixations and within-word refixations, and therefore provides a viable framework for understanding how both linguistic and oculomotor variables affect eye movements in reading.

  9. Low-level laser therapy stimulates bone metabolism and inhibits root resorption during tooth movement in a rodent model.

    Science.gov (United States)

    Suzuki, Selly Sayuri; Garcez, Aguinaldo Silva; Suzuki, Hideo; Ervolino, Edilson; Moon, Won; Ribeiro, Martha Simões

    2016-12-01

    This study evaluated the biological effects of low-level laser therapy (LLLT) on bone remodeling, tooth displacement and root resorption, occurred during the orthodontic tooth movement. Upper first molars of a total of sixty-eight male rats were subjected to orthodontic tooth movement and euthanized on days 3, 6, 9, 14 and 21 days and divided as negative control, control and LLLT group. Tooth displacement and histomorphometric analysis were performed in all animals; scanning electron microscopy analysis was done on days 3, 6 and 9, as well as the immunohistochemistry analysis of RANKL/OPG and TRAP markers. Volumetric changes in alveolar bone were analyzed using MicroCT images on days 14 and 21. LLLT influenced bone resorption by increasing the number of TRAP-positive osteoclasts and the RANKL expression at the compression side. This resulted in less alveolar bone and hyalinization areas on days 6, 9 and 14. LLLT also induced less bone volume and density, facilitating significant acceleration of tooth movement and potential reduction in root resorption besides stimulating bone formation at the tension side by enhancing OPG expression, increasing trabecular thickness and bone volume on day 21. Taken together, our results indicate that LLLT can stimulate bone remodeling reducing root resorption in a rat model. LLLT improves tooth movement via bone formation and bone resorption in a rat model. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Is having similar eye movement patterns during face learning and recognition beneficial for recognition performance? Evidence from hidden Markov modeling.

    Science.gov (United States)

    Chuk, Tim; Chan, Antoni B; Hsiao, Janet H

    2017-12-01

    The hidden Markov model (HMM)-based approach for eye movement analysis is able to reflect individual differences in both spatial and temporal aspects of eye movements. Here we used this approach to understand the relationship between eye movements during face learning and recognition, and its association with recognition performance. We discovered holistic (i.e., mainly looking at the face center) and analytic (i.e., specifically looking at the two eyes in addition to the face center) patterns during both learning and recognition. Although for both learning and recognition, participants who adopted analytic patterns had better recognition performance than those with holistic patterns, a significant positive correlation between the likelihood of participants' patterns being classified as analytic and their recognition performance was only observed during recognition. Significantly more participants adopted holistic patterns during learning than recognition. Interestingly, about 40% of the participants used different patterns between learning and recognition, and among them 90% switched their patterns from holistic at learning to analytic at recognition. In contrast to the scan path theory, which posits that eye movements during learning have to be recapitulated during recognition for the recognition to be successful, participants who used the same or different patterns during learning and recognition did not differ in recognition performance. The similarity between their learning and recognition eye movement patterns also did not correlate with their recognition performance. These findings suggested that perceptuomotor memory elicited by eye movement patterns during learning does not play an important role in recognition. In contrast, the retrieval of diagnostic information for recognition, such as the eyes for face recognition, is a better predictor for recognition performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Computational model for simulation small testing launcher, technical solution

    Science.gov (United States)

    Chelaru, Teodor-Viorel; Cristian, Barbu; Chelaru, Adrian

    2014-12-01

    The purpose of this paper is to present some aspects regarding the computational model and technical solutions for multistage suborbital launcher for testing (SLT) used to test spatial equipment and scientific measurements. The computational model consists in numerical simulation of SLT evolution for different start conditions. The launcher model presented will be with six degrees of freedom (6DOF) and variable mass. The results analysed will be the flight parameters and ballistic performances. The discussions area will focus around the technical possibility to realize a small multi-stage launcher, by recycling military rocket motors. From technical point of view, the paper is focused on national project "Suborbital Launcher for Testing" (SLT), which is based on hybrid propulsion and control systems, obtained through an original design. Therefore, while classical suborbital sounding rockets are unguided and they use as propulsion solid fuel motor having an uncontrolled ballistic flight, SLT project is introducing a different approach, by proposing the creation of a guided suborbital launcher, which is basically a satellite launcher at a smaller scale, containing its main subsystems. This is why the project itself can be considered an intermediary step in the development of a wider range of launching systems based on hybrid propulsion technology, which may have a major impact in the future European launchers programs. SLT project, as it is shown in the title, has two major objectives: first, a short term objective, which consists in obtaining a suborbital launching system which will be able to go into service in a predictable period of time, and a long term objective that consists in the development and testing of some unconventional sub-systems which will be integrated later in the satellite launcher as a part of the European space program. This is why the technical content of the project must be carried out beyond the range of the existing suborbital vehicle

  12. Modeling Small Scale Solar Powered ORC Unit for Standalone Application

    Directory of Open Access Journals (Sweden)

    Enrico Bocci

    2012-01-01

    Full Text Available When the electricity from the grid is not available, the generation of electricity in remote areas is an essential challenge to satisfy important needs. In many developing countries the power generation from Diesel engines is the applied technical solution. However the cost and supply of fuel make a strong dependency of the communities on the external support. Alternatives to fuel combustion can be found in photovoltaic generators, and, with suitable conditions, small wind turbines or microhydroplants. The aim of the paper is to simulate the power generation of a generating unit using the Rankine Cycle and using refrigerant R245fa as a working fluid. The generation unit has thermal solar panels as heat source and photovoltaic modules for the needs of the auxiliary items (pumps, electronics, etc.. The paper illustrates the modeling of the system using TRNSYS platform, highlighting standard and “ad hoc” developed components as well as the global system efficiency. In the future the results of the simulation will be compared with the data collected from the 3 kW prototype under construction in the Tuscia University in Italy.

  13. MODELING AND DESIGN OF INNOVATIVE SMALL DIAMETER GRAVITY SEWERAGE SYSTEM

    Directory of Open Access Journals (Sweden)

    Tadeusz Nawrot

    2017-05-01

    Full Text Available The article presents modern methods of hydraulic design of an innovative small diameter gravity sewerage system. In this system, domestic wastewater is preliminary treated in septic tanks equipped with outlet filters, thus the effluent features are similar to those of clear water. Innovative non-return valves at the outlets eliminate introduction of air to the system and thus the flows can be treated as one-phase ones. Computer codes EPANET 2 and SWMM 5.0 were applied and compared. Two flow schemes typical for the sewerage system were implemented in EPANET 2, and the third - in a slightly modified SWMM 5.0. Simulation results were validated on empirical data obtained on a laboratory physical model, consisting of four tanks of minimum volumes 600 dm3 each, connecting PE pipelines of diameters 25 mm and 36 mm and relevant sanitary fittings. Water inflows, typical for domestic wastewater outflows from single homesteads, were provided by a pump. Water flows were measured using water meters with pulse outputs, and water levels in tanks by pressure transducers. Hydraulic characteristics of filters and non-return valves were provided. Simulation results showed good agreement with the empirical data. Ranges of values of design parameters, needed for successful application of both codes, were established and discussed.

  14. Image-based modelling of nutrient movement in and around the rhizosphere.

    Science.gov (United States)

    Daly, Keith R; Keyes, Samuel D; Masum, Shakil; Roose, Tiina

    2016-02-01

    In this study, we developed a spatially explicit model for nutrient uptake by root hairs based on X-ray computed tomography images of the rhizosphere soil structure. This work extends our previous work to larger domains and hence is valid for longer times. Unlike the model used previously, which considered only a small region of soil about the root, we considered an effectively infinite volume of bulk soil about the rhizosphere. We asked the question: At what distance away from root surfaces do the specific structural features of root-hair and soil aggregate morphology not matter because average properties start dominating the nutrient transport? The resulting model was used to capture bulk and rhizosphere soil properties by considering representative volumes of soil far from the root and adjacent to the root, respectively. By increasing the size of the volumes that we considered, the diffusive impedance of the bulk soil and root uptake were seen to converge. We did this for two different values of water content. We found that the size of region for which the nutrient uptake properties converged to a fixed value was dependent on the water saturation. In the fully saturated case, the region of soil we needed to consider was only of radius 1.1mm for poorly soil-mobile species such as phosphate. However, in the case of a partially saturated medium (relative saturation 0.3), we found that a radius of 1.4mm was necessary. This suggests that, in addition to the geometrical properties of the rhizosphere, there is an additional effect of soil moisture properties, which extends further from the root and may relate to other chemical changes in the rhizosphere. The latter were not explicitly included in our model. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  15. A Biologically Realistic Cortical Model of Eye Movement Control in Reading

    Science.gov (United States)

    Heinzle, Jakob; Hepp, Klaus; Martin, Kevan A. C.

    2010-01-01

    Reading is a highly complex task involving a precise integration of vision, attention, saccadic eye movements, and high-level language processing. Although there is a long history of psychological research in reading, it is only recently that imaging studies have identified some neural correlates of reading. Thus, the underlying neural mechanisms…

  16. Documentation and user's guide for DOSTOMAN: a pathways computer model of radionuclide movement

    International Nuclear Information System (INIS)

    Root, R.W. Jr.

    1980-01-01

    This report documents the mathematical development and the computer implementation of the Savannah River Laboratory computer code used to simulate radonuclide movement in the environment. The user's guide provides all the necessary information for the prospective user to input the required data, execute the computer program, and display the results

  17. Accelerated orthodontic tooth movement following le fort I osteotomy in a rodent model.

    Science.gov (United States)

    Yuan, Hao; Zhu, Xiaofang; Lu, Jingting; Dai, Jiewen; Fang, Bing; Shen, Steve G F

    2014-04-01

    In surgery-first accelerated orthognathic surgery, the clinical phenomenon of accelerated orthodontic tooth movement after osteotomy is a benefit compared with the conventional approach. However, because much of the literature on this phenomenon is based on empirical evidence and case reports, experimental animal-based studies are needed to verify and quantify this acceleration effect. The purpose of this prospective experimental study was to identify whether osteotomy procedures increase tooth movement. Le Fort I osteotomies were performed on the left maxillas in 15 male adult Sprague-Dawley rats. After surgery, a continuous force of 0.5 N was placed on the maxillary left first molar to move the tooth mesially. Another 15 rats had no surgery and served as controls. On days 1, 14, and 28, digital caliper measurements were taken to record tooth movement. In the experimental group, the maxillary left first molars moved significantly more rapidly on days 14 and 28 (P accelerated the rate of orthodontic tooth movement. Histologically, more active and extensive bone remodeling was observed after osteotomy. Copyright © 2014. Published by Elsevier Inc.

  18. Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

    International Nuclear Information System (INIS)

    Reeves, T.L.; Turner, J.P.; Hasfurther, V.R.; Skinner, Q.D.

    1992-06-01

    The scope of this program is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 x 3.0 x 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by RBOSC to carry out this study. Research objectives were designed to evaluate hydrologic, geotechnical, and chemical properties and conditions which would affect the design and performance of large-scale embankments. The objectives of this research are: assess the unsaturated movement and redistribution of water and the development of potential saturated zones and drainage in disposed processed oil shale under natural and simulated climatic conditions; assess the unsaturated movement of solubles and major chemical constituents in disposed processed oil shale under natural and simulated climatic conditions; assess the physical and constitutive properties of the processed oil shale and determine potential changes in these properties caused by disposal and weathering by natural and simulated climatic conditions; assess the use of previously developed computer model(s) to describe the infiltration, unsaturated movement, redistribution, and drainage of water in disposed processed oil shale; evaluate the stability of field scale processed oil shale solid waste embankments using computer models

  19. Combining High-Speed Cameras and Stop-Motion Animation Software to Support Students' Modeling of Human Body Movement

    Science.gov (United States)

    Lee, Victor R.

    2015-04-01

    Biomechanics, and specifically the biomechanics associated with human movement, is a potentially rich backdrop against which educators can design innovative science teaching and learning activities. Moreover, the use of technologies associated with biomechanics research, such as high-speed cameras that can produce high-quality slow-motion video, can be deployed in such a way to support students' participation in practices of scientific modeling. As participants in classroom design experiment, fifteen fifth-grade students worked with high-speed cameras and stop-motion animation software (SAM Animation) over several days to produce dynamic models of motion and body movement. The designed series of learning activities involved iterative cycles of animation creation and critique and use of various depictive materials. Subsequent analysis of flipbooks of human jumping movements created by the students at the beginning and end of the unit revealed a significant improvement in both the epistemic fidelity of students' representations. Excerpts from classroom observations highlight the role that the teacher plays in supporting students' thoughtful reflection of and attention to slow-motion video. In total, this design and research intervention demonstrates that the combination of technologies, activities, and teacher support can lead to improvements in some of the foundations associated with students' modeling.

  20. Pain-Related Brain Activity Evoked by Active and Dynamic Arm Movement: Delayed-Onset Muscle Soreness as a Promising Model for Studying Movement-Related Pain in Humans.

    Science.gov (United States)

    Matsuda, Yoichi; Kan, Shigeyuki; Uematsu, Hironobu; Shibata, Masahiko; Fujino, Yuji

    2015-08-01

    To demonstrate delayed-onset muscle soreness (DOMS) is a suitable model for the study of movement-evoked pain, we attempted to identify brain regions specifically involved in pain evoked by active and dynamic movement under DOMS condition. Twelve healthy volunteers DOMS was induced in the left upper-arm flexor muscles by an eccentric elbow contraction exercise. Movement-evoked pain in the affected muscles was evaluated just before (day 0) and after (days 1-7 and 30) the exercise using a visual analog scale. Subjects underwent functional magnetic resonance imaging scans while performing repeated elbow flexion on day 2 (DOMS condition) and day 30 (painless condition). We compared brain activity between the DOMS and painless conditions. Movement-evoked pain reached peak intensity on day 2 and disappeared by day 30 in all subjects. No subject felt pain at rest on either of these days. Contralateral primary motor cortex (M1), parietal operculum and bilateral presupplementary motor area (pre-SMA) showed greater activity during active and dynamic arm movement with DOMS than during the same movement without pain. There was no difference in activation of brain regions known collectively as the "pain matrix," except for the parietal operculum, between the two conditions. Active and dynamic movement with pain selectively evoked activation of M1, pre-SMA, and parietal operculum, as assessed using DOMS. Our results demonstrate that DOMS is a promising experimental model for the study of movement-evoked pain in humans. 2015 The Authors Pain Medicine published by Wiley Periodicals, Inc. on behalf of American Academy of Pain Medicine.

  1. Using Small Models for Big Issues : Exploratory System Dynamics Modelling and Analysis for Insightful Crisis Management

    NARCIS (Netherlands)

    Pruyt, E.

    2010-01-01

    The main goal of this paper is to explain and illustrate different exploratory uses of small System Dynamics models for analysis and decision support in case of dynamically complex issues that are deeply uncertain. The applied focuss of the paper is the field of inter/national safety and security.

  2. Multiobjective Bak-Sneppen model on a small-world network

    International Nuclear Information System (INIS)

    Elettreby, M.

    2004-09-01

    Small-world networks (SWN) are relevant to biological systems. We study the dynamics of the Bak-Sneppen (BS) model on small-world network, including the concepts of extremal dynamics, multiobjective optimization and coherent noise. We find that the small-world structure stabilizes the system. Also, it is more realistic to augment the Bak-Sneppen model by these concepts. (author)

  3. Multiobjective Bak-Sneppen model on a small-world network

    International Nuclear Information System (INIS)

    Elettreby, M.F.

    2005-01-01

    Small-world networks (SWN) are relevant to biological systems. We study the dynamics of the Bak-Sneppen (BS) model on small-world network, including the concepts of extremal dynamics, multiobjective optimization and coherent noise. We find that the small-world structure stabilizes the system. Also, it is more realistic to augment the Bak-Sneppen model by these concepts

  4. Pest Movement

    Directory of Open Access Journals (Sweden)

    Rod Bhar

    1998-12-01

    Full Text Available Maintenance of woody borders surrounding crop fields is desirable for biodiversity conservation. However, for crop pest management, the desirability of woody borders depends on the trade-off between their effects at the local field scale and the landscape scale. At the local scale, woody borders can reduce pest populations by increasing predation rates, but they can also increase pest populations by providing complementary habitats and reducing movement rate of pests out of crop fields. At the regional scale, woody borders can reduce pest populations by reducing colonization of newly planted crop fields. Our objective was to develop guidelines for maximizing pest control while maintaining woody borders in the landscape. We wished to determine the conditions under which the regional effect of borders on colonization can outweigh local enhancement effects of borders on pest populations. We built a stochastic, individual-based, spatially implicit simulation model of a specialist insect population in a landscape divided into a number of crop fields. We conducted simulations to determine the conditions under which woody borders enhance vs. reduce the regional pest population size. The following factors were considered: landscape fragmentation, crop rotation period, barrier effect of woody borders, disperser success rate, and effect of woody borders on local survival. The simulation results suggest that woody borders are most likely to enhance regional control of crop pests if (1 the woody borders are very effective in reducing insect movement from one crop field to another, and (2 crop rotation is on a very short cycle. Based on these results, our preliminary recommendations are that woody borders should contain dense, tall vegetation to reduce insect movement, and crops should be rotated on as short a cycle as possible. These conditions should ensure that woody borders can be maintained for their conservation value without enhancing crop pest

  5. Modelling and Simulation of the Knee Joint with a Depth Sensor Camera for Prosthetics and Movement Rehabilitation

    International Nuclear Information System (INIS)

    Risto, S; Kallergi, M

    2015-01-01

    The purpose of this project was to model and simulate the knee joint. A computer model of the knee joint was first created, which was controlled by Microsoft's Kinect for Windows. Kinect created a depth map of the knee and lower leg motion independent of lighting conditions through an infrared sensor. A combination of open source software such as Blender, Python, Kinect SDK and NI-Mate were implemented for the creation and control of the simulated knee based on movements of a live physical model. A physical size model of the knee and lower leg was also created, the movement of which was controlled remotely by the computer model and Kinect. The real time communication of the model and the robotic knee was achieved through programming in Python and Arduino language. The result of this study showed that Kinect in the modelling of human kinematics and can play a significant role in the development of prosthetics and other assistive technologies. (paper)

  6. Inflammatory responses in two commonly used rat models for experimental tooth movement: comparison with ligature-induced periodontitis.

    Science.gov (United States)

    Xie, Rui; Kuijpers-Jagtman, Anne Marie; Maltha, Jaap C

    2011-02-01

    To compare two often used rat models for experimental tooth movement, namely the elastic band, and the coil spring model. They were compared with a silk-ligature-induced periodontitis model. Thirty six, 6-weeks-old rats were used. In a split mouth design four experimental conditions were allocated by permutation: (1) insertion of an orthodontic elastic band between the maxillary first and the second molar, (2) placement of a silk ligature around the cervix of the upper second molar, (3) a 10cN NiTi coil spring for mesial movement of the three maxillary molars as one block, and (4) Control. After 1, 3, and 5 days, rats were killed and immunohistochemical staining for ED1, cathepsin K, and MMP9 was performed. A time-dependent increase in the inflammatory infiltration of the interdental papilla was found in the elastic band and the ligature model, but not in the spring model. The disruption of the epithelium of the interdental papilla and the transseptal fibers was less severe in the spring group than in the other two experimental groups. All three experimental groups showed a time-dependent resorption of the interdental bony septum. However, this started faster and was more severe in the elastic band and the ligature than in the spring group. The numbers of cathepsin K+ and MMP9+ cells were higher in the elastic band and the ligature group than in the spring group. Elastic bands yield similar periodontal effects as ligatures. The spring model is to be preferred for experimental tooth movement studies. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. ORGANIZATIONAL CHANGE MODELS IN SMALL AND MEDIUM SIZED ENTERPRISES (SMES)

    OpenAIRE

    Oliviana Bold, Ph. D Student

    2011-01-01

    Bringing forward the concepts of change and change management is no longer surprising nowadays. Small and Medium Enterprises (SMEs) face unique and difficult challenges in the business environment. Challenges to the growth and viability of Small and Medium Enterprises (SMEs) are arising from several external factors, like globalization, increased customer expectations or competition, technological advances, all of the factors being determined by the change. SMEs need to successfully deal with...

  8. The virtual promenade, didactic experiments on the potentials of combining conventional and digital modelling of the city experienced in movement

    DEFF Research Database (Denmark)

    Kreutzberg, Anette; Bohn, Claus

    2014-01-01

    and digital modelling. The workshop serves as an education-based research project in which we want to investigate the potentials of working consciously with bodily movement as a generator in the creation of architecture by combining actual experience of the city with conventional model building and digital...... in the education of future architects? This paper is therefore likewise divided. The first part is about the city and the architectural tools involved in the workshop. This section is titled Representing the City. The second part is elaborating on the technical aspects of the Virtual Reality technology used...

  9. To Pass or Not to Pass: Modeling the Movement and Affordance Dynamics of a Pick and Place Task

    Directory of Open Access Journals (Sweden)

    Maurice Lamb

    2017-06-01

    Full Text Available Humans commonly engage in tasks that require or are made more efficient by coordinating with other humans. In this paper we introduce a task dynamics approach for modeling multi-agent interaction and decision making in a pick and place task where an agent must move an object from one location to another and decide whether to act alone or with a partner. Our aims were to identify and model (1 the affordance related dynamics that define an actor's choice to move an object alone or to pass it to their co-actor and (2 the trajectory dynamics of an actor's hand movements when moving to grasp, relocate, or pass the object. Using a virtual reality pick and place task, we demonstrate that both the decision to pass or not pass an object and the movement trajectories of the participants can be characterized in terms of a behavioral dynamics model. Simulations suggest that the proposed behavioral dynamics model exhibits features observed in human participants including hysteresis in decision making, non-straight line trajectories, and non-constant velocity profiles. The proposed model highlights how the same low-dimensional behavioral dynamics can operate to constrain multiple (and often nested levels of human activity and suggests that knowledge of what, when, where and how to move or act during pick and place behavior may be defined by these low dimensional task dynamics and, thus, can emerge spontaneously and in real-time with little a priori planning.

  10. State Models to Incentivize and Streamline Small Hydropower Development

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Taylor [National Renewable Energy Lab. (NREL), Golden, CO (United States); Levine, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Johnson, Kurt [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-10-31

    In 2016, the hydropower fleet in the United States produced more than 6 percent (approximately 265,829 gigawatt-hours [GWh]) of the total net electricity generation. The median-size hydroelectric facility in the United States is 1.6 MW and 75 percent of total facilities have a nameplate capacity of 10 MW or less. Moreover, the U.S. Department of Energy's Hydropower Vision study identified approximately 79 GW hydroelectric potential beyond what is already developed. Much of the potential identified is at low-impact new stream-reaches, existing conduits, and non-powered dams with a median project size of 10 MW or less. To optimize the potential and value of small hydropower development, state governments are crafting policies that provide financial assistance and expedite state and federal review processes for small hydroelectric projects. This report analyzes state-led initiatives and programs that incentivize and streamline small hydroelectric development.

  11. Low back pain patients' responses to videos of avoided movements.

    Science.gov (United States)

    Pincus, T; Henderson, J

    2013-02-01

    Fear avoidance (FA) has been identified as a risk factor for poor prognosis and a target for intervention in patients with low back pain (LBP), but the mechanisms involved need clarification. Experimental studies would benefit from the use of carefully developed and controlled stimuli representing avoided movements in back pain, and matched stimuli of movements to provide a credible control stimuli. Existing stimuli depicting avoided movements in LBP are static, do not include a set of control stimuli and do not control for possible systematic observer biases. Two studies were carried out aiming to develop and test LBP patients' responses to videos of models depicting commonly avoided movements associated with back pain, and those associated with a control condition, wrist pain. Two samples of LBP patients rated how much pain and harm each movement would cause them. They also reported how often they avoided the movement. The findings from the first study (n = 99) indicate that using videos of commonly avoided movements in low back pain is viable, and that movements associated with wrist pain provide an acceptable control stimuli. Participants in the second study (n = 85) consistently rated movements depicted by females as causing more harm, and more frequently avoided than the same movements depicted by males. The use of video stimuli could advance research into the processes associated with FA through experimental paradigms. However, although small, the model gender effects should be carefully considered. © 2012 European Federation of International Association for the Study of Pain Chapters.

  12. Effect of cetirizine, a histamine (H(1)) receptor antagonist, on bone modeling during orthodontic tooth movement in rats.

    Science.gov (United States)

    Meh, Alja; Sprogar, Spela; Vaupotic, Tomaz; Cör, Andrej; Drevenšek, Gorazd; Marc, Janja; Drevenšek, Martina

    2011-04-01

    Histamine (H(1)) receptor antagonists are widely used drugs for treatment of allergic conditions. Although histamine was shown to be involved in bone remodeling, the aim of this study was to determine the effects of cetirizine, an H(1) receptor antagonist, on bone modeling processes during orthodontic tooth movement. We used 3 groups of Wistar rats: control group (n = 16), appliance-only group (n = 16) and cetirizine group (n = 16). Each animal of the last 2 groups was fitted with a superelastic closed-coil spring appliance and treated daily with saline solution or cetirizine. Tooth movement was measured weekly from day 0 to day 42. Gene expression levels for bone turnover markers cathepsin K and osteocalcin were determined by means of real-time polymerase chain reaction. Histologic samples were analyzed by using histomorphometry. Cetirizine decreased the amount of tooth movement from day 28 onward (P orthodontic treatment. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  13. Effects of dwell time of excitation waveform on meniscus movements for a tubular piezoelectric print-head: experiments and model

    Science.gov (United States)

    Chang, Jiaqing; Liu, Yaxin; Huang, Bo

    2017-07-01

    In inkjet applications, it is normal to search for an optimal drive waveform when dispensing a fresh fluid or adjusting a newly fabricated print-head. To test trial waveforms with different dwell times, a camera and a strobe light were used to image the protruding or retracting liquid tongues without ejecting any droplets. An edge detection method was used to calculate the lengths of the liquid tongues to draw the meniscus movement curves. The meniscus movement is determined by the time-domain response of the acoustic pressure at the nozzle of the print-head. Starting at the inverse piezoelectric effect, a mathematical model which considers the liquid viscosity in acoustic propagation is constructed to study the acoustic pressure response at the nozzle of the print-head. The liquid viscosity retards the propagation speed and dampens the harmonic amplitude. The pressure response, which is the combined effect of the acoustic pressures generated during the rising time and the falling time and after their propagations and reflections, explains the meniscus movements well. Finally, the optimal dwell time for droplet ejections is discussed.

  14. Effects of dwell time of excitation waveform on meniscus movements for a tubular piezoelectric print-head: experiments and model

    International Nuclear Information System (INIS)

    Chang, Jiaqing; Liu, Yaxin; Huang, Bo

    2017-01-01

    In inkjet applications, it is normal to search for an optimal drive waveform when dispensing a fresh fluid or adjusting a newly fabricated print-head. To test trial waveforms with different dwell times, a camera and a strobe light were used to image the protruding or retracting liquid tongues without ejecting any droplets. An edge detection method was used to calculate the lengths of the liquid tongues to draw the meniscus movement curves. The meniscus movement is determined by the time-domain response of the acoustic pressure at the nozzle of the print-head. Starting at the inverse piezoelectric effect, a mathematical model which considers the liquid viscosity in acoustic propagation is constructed to study the acoustic pressure response at the nozzle of the print-head. The liquid viscosity retards the propagation speed and dampens the harmonic amplitude. The pressure response, which is the combined effect of the acoustic pressures generated during the rising time and the falling time and after their propagations and reflections, explains the meniscus movements well. Finally, the optimal dwell time for droplet ejections is discussed. (paper)

  15. Water Distribution Network Modelling of a Small Community using ...

    African Journals Online (AJOL)

    ... of a small community (Sakwa) water distribution network in North Eastern geopolitical region of Nigeria using WaterCAD simulator. The analysis included a review of pressures, velocities and head loss gradients under steady state average day demand, maximum day demand conditions, and fire flow under maximum day ...

  16. Computational approaches for efficiently modelling of small atmospheric clusters

    DEFF Research Database (Denmark)

    Elm, Jonas; Mikkelsen, Kurt Valentin

    2014-01-01

    the basis set used in the geometry and frequency calculation from 6-311++G(3df,3pd) → 6-31++G(d,p) implies a significant speed-up in computational time and only leads to small errors in the thermal contribution to the Gibbs free energy and subsequent coupled cluster single point energy calculation....

  17. inverse gaussian model for small area estimation via gibbs sampling

    African Journals Online (AJOL)

    ADMIN

    For example, MacGibbon and Tomberlin. (1989) have considered estimating small area rates and binomial parameters using empirical Bayes methods. Stroud (1991) used hierarchical Bayes approach for univariate natural exponential families with quadratic variance functions in sample survey applications, while Chaubey ...

  18. A feasibility and implementation model of small-scale hydropower ...

    African Journals Online (AJOL)

    Large numbers of households and communities will not be connected to the national electricity grid for the foreseeable future due to high cost of transmission and distribution systems to remote communities and the relatively low electricity demand within rural communities. Small-scale hydropower used to play a very ...

  19. Modelling of a Small Scale Waste Water Treatment Plant (SSWWTP)

    African Journals Online (AJOL)

    PROF. OLIVER OSUAGWA

    2014-06-01

    Jun 1, 2014 ... the waste water [3]. Aim. The aim of this project is to bring into existence a Small Scale Waste Water. Treatment Plant that can convert a waste water with high Chemical Oxygen ... Reduce water born disease and high acidic nature of water ... proper maintenance and operation training is made available to ...

  20. Interactive effects of periodontitis and orthodontic tooth movement on dental root resorption, tooth movement velocity and alveolar bone loss in a rat model.

    Science.gov (United States)

    Kirschneck, Christian; Fanghänel, Jochen; Wahlmann, Ulrich; Wolf, Michael; Roldán, J Camilo; Proff, Peter

    2017-03-01

    Many adult orthodontic patients suffer from chronic periodontitis with recurrent episodes of active periodontal inflammation. As their number is steadily increasing, orthodontists are more and more frequently challenged by respective treatment considerations. However, little is currently known regarding interactive effects on undesired dental root resorption (DRR), tooth movement velocity, periodontal bone loss and the underlying cellular and tissue reactions. A total of 63 male Fischer344 rats were used in three consecutive experiments employing 21 animals each (A/B/C), randomly assigned to 3 experimental groups (n=7, 1/2/3), respectively: (A) CBCT; (B) histology/serology; (C) RT-qPCR-(1) control; (2) orthodontic tooth movement (OTM) of the first/second upper left molars (NiTi coil spring, 0.25N); (3) OTM with experimentally induced periodontitis (cervical silk ligature). After 14days of OTM, we quantified blood leukocyte level, DRR, osteoclast activity and relative gene expression of inflammatory and osteoclast marker genes within the dental-periodontal tissue as well as tooth movement velocity and periodontal bone loss after 14 and 28 days. The experimentally induced periodontal bone loss was significantly increased by concurrent orthodontic force application. Periodontal inflammation during OTM on the other hand significantly augmented the extent of DRR, relative expression of inflammatory/osteoclast marker genes, blood leukocyte level and periodontal osteoclast activity. In addition, contrary to previous studies, we observed a significant increase in tooth movement velocity. Although accelerated tooth movement would be favourable for orthodontic treatment, our results suggest that orthodontic interventions should only be performed after successful systematic periodontal therapy and paused in case of recurrent active inflammation. Copyright © 2016 Elsevier GmbH. All rights reserved.

  1. Eye Movement Deficits Are Consistent with a Staging Model of pTDP-43 Pathology in Amyotrophic Lateral Sclerosis.

    Directory of Open Access Journals (Sweden)

    Martin Gorges

    Full Text Available The neuropathological process underlying amyotrophic lateral sclerosis (ALS can be traced as a four-stage progression scheme of sequential corticofugal axonal spread. The examination of eye movement control gains deep insights into brain network pathology and provides the opportunity to detect both disturbance of the brainstem oculomotor circuitry as well as executive deficits of oculomotor function associated with higher brain networks.To study systematically oculomotor characteristics in ALS and its underlying network pathology in order to determine whether eye movement deterioration can be categorized within a staging system of oculomotor decline that corresponds to the neuropathological model.Sixty-eight ALS patients and 31 controls underwent video-oculographic, clinical and neuropsychological assessments.Oculomotor examinations revealed increased anti- and delayed saccades' errors, gaze-palsy and a cerebellary type of smooth pursuit disturbance. The oculomotor disturbances occurred in a sequential manner: Stage 1, only executive control of eye movements was affected. Stage 2 indicates disturbed executive control plus 'genuine' oculomotor dysfunctions such as gaze-paly. We found high correlations (p<0.001 between the oculomotor stages and both, the clinical presentation as assessed by the ALS Functional Rating Scale (ALSFRS score, and cognitive scores from the Edinburgh Cognitive and Behavioral ALS Screen (ECAS.Dysfunction of eye movement control in ALS can be characterized by a two-staged sequential pattern comprising executive deficits in Stage 1 and additional impaired infratentorial oculomotor control pathways in Stage 2. This pattern parallels the neuropathological staging of ALS and may serve as a technical marker of the neuropathological spreading.

  2. Relation between velocity and curvature in movement: equivalence and divergence between a power law and a minimum-jerk model.

    Science.gov (United States)

    Wann, J; Nimmo-Smith, I; Wing, A M

    1988-11-01

    Unconstrained hand movements typically display a decrease in hand speed around highly curved sections of a trajectory. It has been suggested that this relation between tangential velocity and radius of curvature conforms to a one-third power law. We demonstrate that a one-third power law can be explained by models taking account of trajectory costs such as a minimum-jerk model. Data were analyzed from 6 subjects performing elliptical drawing movements of varying eccentricities. Conformity to the one-third power law in the average was obtained but is shown to be artifactual. It is demonstrated that asymmetric velocity profiles may result in consistent departures from a one-third power law but that such differences may be masked by inappropriate analysis procedures. We introduce a modification to the original minimum-jerk model by replacing the assumption of a Newtonian point-mass with a visco-elastic body. Simulations with the modified model identify a basis for asymmetry of velocity profiles and thereby predict departures from a one-third law commensurate with the empirical findings.

  3. Theoretical modelling of the movement of sodium fire fumes in a building

    International Nuclear Information System (INIS)

    Vaughan, G.J.; Simpson, C.P.; Smith, A.G.

    1989-01-01

    The important effect that the thermal hydraulic behaviour in a containment can have on the burning rate of a sodium fire is discussed. To explore the nature of the convective motion induced y the fire and how these might be affected by the containment morphology, calculations with a thermal hydraulic code, PHOENICS, were carried out. This code has also been used to investigate the movement of the smoke cloud produced by a fire to support a study of the use of a venting system. Both studies are reported and some conclusions on the role of thermal hydraulic phenomena on sodium fire investigations are made. (author)

  4. Wireless inclinometer acquisition system for reducing swing movement control module experiment of hook model

    Science.gov (United States)

    Yu, Yan; Ou, Jinping; Zhang, Chunwei; Li, Luyu

    2008-03-01

    Large Scale Heavy Derrick Lay Barge is very important for sea work. Under intense wind and wave load, the hook on the Barge will vibrate so large that in some cases it can not work. Through installing the Tuned Mass Damper(TMD) on the hook, the vibration will be reduced to a certain range to meet the demand on sea work, which is also important for increasing the efficiency of sea work. To design the suitable TMD for the hook, the dynamical parameters should be specified beforehand. Generally, the related dynamical parameters such as inclinometer and acceleration are measured by wire sensors. But due to the restriction of the actual condition, the wire sensors are very hard to implement. Recently, the wireless sensors have been presented to overcome the shortcomings of wire ones. It is more suitable and also convenient to utilize wireless sensors to acquire the useful data of large scale heavy derrick lay barge. In this paper, the hook reducing swing movement control module is designed for large scale heavy derrick lay barge. Secondly, wireless inclinometer sensor system is integrated using the technique of MEMS, sensing and wireless communication. Finally, the hook reducing swing movement control module is validated by the developed wireless inclinometer data acquisition system. The wireless inclinometer sensor can be used not only in swing monitoring for large scale heavy derrick lay barge's Hook, but also in vibration monitoring for TV tower, large crane. In general, it has great application foreground.

  5. Distribution of fluorescein sodium and triamcinolone acetonide in the simulated liquefied and vitrectomized Vitreous Model with simulated eye movements.

    Science.gov (United States)

    Stein, Sandra; Bogdahn, Malte; Rosenbaum, Christoph; Weitschies, Werner; Seidlitz, Anne

    2017-11-15

    Intravitreal administration is the method of choice for drug delivery to the posterior segment of the eye with special emphasis on the vitreous body and its surrounding retinal vasculature. In order to gain a better understanding of the underlying distribution processes, an in vitro model simulating the vitreous body (Vitreous Model, VM) and a system simulating the impact of movement on the VM (Eye Movement System, EyeMoS) was previously developed. In the study reported here, these systems were modified in regard to a standardized injection procedure, the diversity of simulated eye movements, extended periods of investigation, the opportunity to simulate the state after vitrectomy and in considering the physiological temperature. Fluorescein sodium (FS) and triamcinolone acetonide (TA) were used as (model) drugs to examine the drug distribution within the VM. Vitrectomy was simulated by replacing half the volume of the polyacrylamide gel that was used as vitreous substitute with the clinically used Siluron® 5000 whereas for a simulated liquefaction half the volume of the gel was replaced by buffer. A simulated liquefaction caused a 12-fold faster distribution of FS compared to the simulated juvenile VM, which was most likely caused by convective forces and mass transfer. Also, the injection technique (injection into the gel or into the buffer compartment) influenced the resulting distribution pattern. Without any liquefaction, the previously described initial injection channel occurred with both (model) drugs and, in the case of TA, remained almost unchanged during the investigation period of 72h. Simulating vitrectomized eyes, TA did not spread uniformly, but either remained in the depot or strongly sedimented within the VM suggesting that a homogenous distribution of a TA suspension is highly unlikely in vitrectomized eyes. High variabilities were observed with ex vivo animal eyes, demonstrating the limited benefit of explanted tissues for such distribution

  6. Statistical credit risk assessment model of small and very small enterprises for Lithuanian credit unions

    OpenAIRE

    Špicas, Renatas

    2017-01-01

    While functioning in accordance with the new, business and efficiency-oriented operating model, credit unions develop and begin functioning outside the community. It is universally recognised in scientific literature that as credit unions expand their activities beyond a community, social relations with credit union members weaken and the credit unions lose their social control element, which help them to better assess and manage information asymmetry and credit risk. So far, the analysis of ...

  7. [Stereotypic movements].

    Science.gov (United States)

    Fernández-Alvarez, E

    2003-02-01

    Stereotypic movements are repetitive patterns of movement with certain peculiar features that make them especially interesting. Their physiopathology and their relationship with the neurobehavioural disorders they are frequently associated with are unknown. In this paper our aim is to offer a simple analysis of their dominant characteristics, their differentiation from other processes and a hypothesis of the properties of stereotypic movements, which could all set the foundations for research work into their physiopathology.

  8. Large Scale Community Detection Using a Small World Model

    Directory of Open Access Journals (Sweden)

    Ranjan Kumar Behera

    2017-11-01

    Full Text Available In a social network, small or large communities within the network play a major role in deciding the functionalities of the network. Despite of diverse definitions, communities in the network may be defined as the group of nodes that are more densely connected as compared to nodes outside the group. Revealing such hidden communities is one of the challenging research problems. A real world social network follows small world phenomena, which indicates that any two social entities can be reachable in a small number of steps. In this paper, nodes are mapped into communities based on the random walk in the network. However, uncovering communities in large-scale networks is a challenging task due to its unprecedented growth in the size of social networks. A good number of community detection algorithms based on random walk exist in literature. In addition, when large-scale social networks are being considered, these algorithms are observed to take considerably longer time. In this work, with an objective to improve the efficiency of algorithms, parallel programming framework like Map-Reduce has been considered for uncovering the hidden communities in social network. The proposed approach has been compared with some standard existing community detection algorithms for both synthetic and real-world datasets in order to examine its performance, and it is observed that the proposed algorithm is more efficient than the existing ones.

  9. Movement ecology: size-specific behavioral response of an invasive snail to food availability.

    Science.gov (United States)

    Snider, Sunny B; Gilliam, James F

    2008-07-01

    Immigration, emigration, migration, and redistribution describe processes that involve movement of individuals. These movements are an essential part of contemporary ecological models, and understanding how movement is affected by biotic and abiotic factors is important for effectively modeling ecological processes that depend on movement. We asked how phenotypic heterogeneity (body size) and environmental heterogeneity (food resource level) affect the movement behavior of an aquatic snail (Tarebia granifera), and whether including these phenotypic and environmental effects improves advection-diffusion models of movement. We postulated various elaborations of the basic advection diffusion model as a priori working hypotheses. To test our hypotheses we measured individual snail movements in experimental streams at high- and low-food resource treatments. Using these experimental movement data, we examined the dependency of model selection on resource level and body size using Akaike's Information Criterion (AIC). At low resources, large individuals moved faster than small individuals, producing a platykurtic movement distribution; including size dependency in the model improved model performance. In stark contrast, at high resources, individuals moved upstream together as a wave, and body size differences largely disappeared. The model selection exercise indicated that population heterogeneity is best described by the advection component of movement for this species, because the top-ranked model included size dependency in advection, but not diffusion. Also, all probable models included resource dependency. Thus population and environmental heterogeneities both influence individual movement behaviors and the population-level distribution kernels, and their interaction may drive variation in movement behaviors in terms of both advection rates and diffusion rates. A behaviorally informed modeling framework will integrate the sentient response of individuals in terms of

  10. Small Animal [18F]FDG PET Imaging for Tumor Model Study

    International Nuclear Information System (INIS)

    Woo, Sang Keun; Kim, Kyeong Min; Cheon, Gi Jeong

    2008-01-01

    PET allows non-invasive, quantitative and repetitive imaging of biological function in living animals. Small animal PET imaging with [ 18 F]FDG has been successfully applied to investigation of metabolism, receptor, ligand interactions, gene expression, adoptive cell therapy and somatic gene therapy. Experimental condition of animal handling impacts on the biodistribution of [ 18 F]FDG in small animal study. The small animal PET and CT images were registered using the hardware fiducial markers and small animal contour point. Tumor imaging in small animal with small animal [ 18 F]FDG PET should be considered fasting, warming, and isoflurane anesthesia level. Registered imaging with small animal PET and CT image could be useful for the detection of tumor. Small animal experimental condition of animal handling and registration method will be of most importance for small lesion detection of metastases tumor model

  11. Spatial modeling of personalized exposure dynamics: the case of pesticide use in small-scale agricultural production landscapes of the developing world

    Directory of Open Access Journals (Sweden)

    Binder Claudia R

    2009-03-01

    Full Text Available Abstract Background Pesticide poisoning is a global health issue with the largest impacts in the developing countries where residential and small-scale agricultural areas are often integrated and pesticides sprayed manually. To reduce health risks from pesticide exposure approaches for personalized exposure assessment (PEA are needed. We present a conceptual framework to develop a spatial individual-based model (IBM prototype for assessing potential exposure of farm-workers conducting small-scale agricultural production, which accounts for a considerable portion of global food crop production. Our approach accounts for dynamics in the contaminant distributions in the environment, as well as patterns of movement and activities performed on an individual level under different safety scenarios. We demonstrate a first prototype using data from a study area in a rural part of Colombia, South America. Results Different safety scenarios of PEA were run by including weighting schemes for activities performed under different safety conditions. We examined the sensitivity of individual exposure estimates to varying patterns of pesticide application and varying individual patterns of movement. This resulted in a considerable variation in estimates of magnitude, frequency and duration of exposure over the model runs for each individual as well as between individuals. These findings indicate the influence of patterns of pesticide application, individual spatial patterns of movement as well as safety conditions on personalized exposure in the agricultural production landscape that is the focus of our research. Conclusion This approach represents a conceptual framework for developing individual based models to carry out PEA in small-scale agricultural settings in the developing world based on individual patterns of movement, safety conditions, and dynamic contaminant distributions. The results of our analysis indicate our prototype model is sufficiently

  12. Modelling the Diel Vertical Movement of Swordfish (Xiphias gladius Linnaeus, 1758 Based on Temperature and Depth Recorder Data

    Directory of Open Access Journals (Sweden)

    Bram Setyadji

    2016-03-01

    Full Text Available Understanding the vertical distribution of large pelagic fish, swordfish in particular, could improve our knowledge on its fisheries strategy, management and resource conservation. However the methods often require expensive tools and resources, which probably most scientists from the development countries couldn’t afford. Thus developing model on the diel vertical movement behavior of swordfish using number of hook between float (HBF and complete-set temperature and depth recorder (TDR data could be an alternative. In general context, capture depth distributions are a good indicator of the natural depth distribution of the fish if the entire depth range of the species is targeted by longline gear. The proposed sinusoidal model suggested that swordfish showed a diel pattern in depth distribution, marked by remained in the surface and mixed layer waters at night and dived into deeper waters during the day. Keywords: swordfish, behavior, HBF, TDR, sinusoidal model

  13. Transferable Atomic Multipole Machine Learning Models for Small Organic Molecules.

    Science.gov (United States)

    Bereau, Tristan; Andrienko, Denis; von Lilienfeld, O Anatole

    2015-07-14

    Accurate representation of the molecular electrostatic potential, which is often expanded in distributed multipole moments, is crucial for an efficient evaluation of intermolecular interactions. Here we introduce a machine learning model for multipole coefficients of atom types H, C, O, N, S, F, and Cl in any molecular conformation. The model is trained on quantum-chemical results for atoms in varying chemical environments drawn from thousands of organic molecules. Multipoles in systems with neutral, cationic, and anionic molecular charge states are treated with individual models. The models' predictive accuracy and applicability are illustrated by evaluating intermolecular interaction energies of nearly 1,000 dimers and the cohesive energy of the benzene crystal.

  14. Out of the net: An agent-based model to study human movements influence on local-scale malaria transmission.

    Science.gov (United States)

    Pizzitutti, Francesco; Pan, William; Feingold, Beth; Zaitchik, Ben; Álvarez, Carlos A; Mena, Carlos F

    2018-01-01

    Though malaria control initiatives have markedly reduced malaria prevalence in recent decades, global eradication is far from actuality. Recent studies show that environmental and social heterogeneities in low-transmission settings have an increased weight in shaping malaria micro-epidemiology. New integrated and more localized control strategies should be developed and tested. Here we present a set of agent-based models designed to study the influence of local scale human movements on local scale malaria transmission in a typical Amazon environment, where malaria is transmission is low and strongly connected with seasonal riverine flooding. The agent-based simulations show that the overall malaria incidence is essentially not influenced by local scale human movements. In contrast, the locations of malaria high risk spatial hotspots heavily depend on human movements because simulated malaria hotspots are mainly centered on farms, were laborers work during the day. The agent-based models are then used to test the effectiveness of two different malaria control strategies both designed to reduce local scale malaria incidence by targeting hotspots. The first control scenario consists in treat against mosquito bites people that, during the simulation, enter at least once inside hotspots revealed considering the actual sites where human individuals were infected. The second scenario involves the treatment of people entering in hotspots calculated assuming that the infection sites of every infected individual is located in the household where the individual lives. Simulations show that both considered scenarios perform better in controlling malaria than a randomized treatment, although targeting household hotspots shows slightly better performance.

  15. Small- and large-signal modeling of InP HBTs in transferred-substrate technology

    DEFF Research Database (Denmark)

    Johansen, Tom Keinicke; Rudolph, Matthias; Jensen, Thomas

    2014-01-01

    a direct parameter extraction methodology dedicated to III–V based HBTs. It is shown that the modeling of measured S-parameters can be improved in the millimeter-wave frequency range by augmenting the small-signal model with a description of AC current crowding. The extracted elements of the small......-signal model structure are employed as a starting point for the extraction of a large-signal model. The developed large-signal model for the TS-HBTs accurately predicts the DC over temperature and small-signal performance over bias as well as the large-signal performance at millimeter-wave frequencies....

  16. Hydrological Modelling of Small Scale Processes in a Wetland Habitat

    DEFF Research Database (Denmark)

    Johansen, Ole; Jensen, Jacob Birk; Pedersen, Morten Lauge

    2009-01-01

    Numerical modelling of the hydrology in a Danish rich fen area has been conducted. By collecting various data in the field the model has been successfully calibrated and the flow paths as well as the groundwater discharge distribution have been simulated in details. The results of this work have...

  17. Framing Negotiation: Dynamics of Epistemological and Positional Framing in Small Groups during Scientific Modeling

    Science.gov (United States)

    Shim, Soo-Yean; Kim, Heui-Baik

    2018-01-01

    In this study, we examined students' epistemological and positional framing during small group scientific modeling to explore their context-dependent perceptions about knowledge, themselves, and others. We focused on two small groups of Korean eighth-grade students who participated in six modeling activities about excretion. The two groups were…

  18. Size Matters: Observed and Modeled Camouflage Response of European Cuttlefish (Sepia officinalis) to Different Substrate Patch Sizes during Movement.

    Science.gov (United States)

    Josef, Noam; Berenshtein, Igal; Rousseau, Meghan; Scata, Gabriella; Fiorito, Graziano; Shashar, Nadav

    2016-01-01

    Camouflage is common throughout the phylogenetic tree and is largely used to minimize detection by predator or prey. Cephalopods, and in particular Sepia officinalis cuttlefish, are common models for camouflage studies. Predator avoidance behavior is particularly important in this group of soft-bodied animals that lack significant physical defenses. While previous studies have suggested that immobile cephalopods selectively camouflage to objects in their immediate surroundings, the camouflage characteristics of cuttlefish during movement are largely unknown. In a heterogenic environment, the visual background and substrate feature changes quickly as the animal swim across it, wherein substrate patch is a distinctive and high contrast patch of substrate in the animal's trajectory. In the current study, we examine the effect of substrate patch size on cuttlefish camouflage, and specifically the minimal size of an object for eliciting intensity matching response while moving. Our results indicated that substrate patch size has a positive effect on animal's reflectance change, and that the threshold patch size resulting in camouflage response falls between 10 and 19 cm (width). These observations suggest that the animal's length (7.2-12.3 cm mantle length in our case) serves as a possible threshold filter below which objects are considered irrelevant for camouflage, reducing the frequency of reflectance changes-which may lead to detection. Accordingly, we have constructed a computational model capturing the main features of the observed camouflaging behavior, provided for cephalopod camouflage during movement.

  19. STOOKE SMALL BODY SHAPE MODELS V2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Philip Stooke shape models for 243 Ida, 253 Mathilde, 951 Gaspra, comet Halley, J5 Amalthea, J14 Thebe, N7 Larissa, N8 Proteus, S10 Janus, S11...

  20. Pesticide modelling for a small catchment using SWAT-2000.

    Science.gov (United States)

    Kannan, Narayanan; White, Sue M; Worrall, Fred; Whelan, Mick J

    2006-01-01

    Pesticides in stream flow from the 142 ha Colworth catchment in Bedfordshire, UK were monitored from October 1999 to December 2000. About 47% of the catchment is tile-drained and different pesticides and cropping patterns have recently been evaluated in terms of their effect on nutrient and pesticide losses to the stream. The data from Colworth were used to test soil and water assessment tool (SWAT) 2000 predictions of pesticide concentrations at the catchment outlet. A sound model set-up to carry out pesticide modelling was created by means of hydrological modelling with proper simulation of crop growth and evapotranspiration. The pesticides terbuthylazine, terbutryn, cyanazine and bentazone were modelled. There was close agreement between SWAT-predicted pesticide concentration values and observations. Scenario trials were conducted to explore management options for reducing pesticide loads arriving at the catchment outlet. The results obtained indicate that SWAT can be used as a tool to understand pesticide behavior at the catchment scale.

  1. SU-E-J-134: Motion Modeling of Non-Small Cell Lung Nodules Based on Respiratory Mechanics.

    Science.gov (United States)

    Serratore, D; Hartl, B; Chan, P; Neicu, T; Li, S

    2012-06-01

    To quantify the movements of non-small cell lung nodules using 4D cone-beam computed tomography (4D-CBCT) that is automatically registered with planning CT, and to develop a mathematical model to predict the motion trajectory. Modeling the tumor motion may reduce the PTV and ultimately increase the therapeutic ratio. Absolute coordinates of the lung nodules in 15 patients were quantified for each phase of 4D-CBCT scans using auto-registration methods. Assuming respiration follows an elliptical pattern spatially in the lung, these coordinates were fitted to trigonometric functions in each x-y-z direction. Adjusting for phase dependence, the motion could be compared quantitatively for inter-fractional and intra-patient variations to determine if this model is universally applicable and has predictive value. Examination of over 36 sets of 4D-CBCT data shows acceptable agreement (elliptical model for both individual scans and over the course of treatment. Some inter-fractional variations in amplitude and cycling periods indicate the need to remodel as patients' conditions change. The intra-patient variations are significant and strongly dependent on the patient lung volume and tumor location, thus individual modeling of tumor motion is expected. The model indicates good agreement and clinical relevance with non-small cell lung nodule motion, and it appears to be potentially relevant over the course of treatment. Most re-acquired 4D-CBCT images inter-fractionally were within the baseline spatial resolution of the auto- registration technique. However, if remodeling is necessary inter-fractionally, this model still has the potential for significant motion margin reduction over the course of treatment. © 2012 American Association of Physicists in Medicine.

  2. Salt movements and faulting of the overburden - can numerical modeling predict the fault patterns above salt structures?

    DEFF Research Database (Denmark)

    Clausen, O.R.; Egholm, D.L.; Wesenberg, Rasmus

    among other things the productivity due to the segmentation of the reservoir (Stewart 2006). 3D seismic data above salt structures can map such fault patterns in great detail and studies have shown that a variety of fault patterns exists. Yet, most patterns fall between two end members: concentric....... radiating) can thus be linked to two different styles of salt movement: i) the vertical rising of a salt indenter and ii) the inflation of a ‘salt-balloon’ beneath the deformed strata. The results are in accordance with published analogue and theoretical models, as well as natural systems, and the model may...... the hydrocarbon production from reservoirs located above salt structures is optimized....

  3. Heterogeneous movement of insectivorous Amazonian birds through primary and secondary forest: A case study using multistate models with radiotelemetry data

    Science.gov (United States)

    Hines, James; Powell, Luke L.; Wolfe, Jared D.; Johnson, Erik l.; Nichols, James D.; Stouffer, Phillip C.

    2015-01-01

    Given rates of deforestation, disturbance, and secondary forest accumulation in tropical rainforests, there is a great need to quantify habitat use and movement among different habitats. This need is particularly pronounced for animals most sensitive to disturbance, such as insectivorous understory birds. Here we use multistate capture–recapture models with radiotelemetry data to determine the successional stage at which within-day movement probabilities of Amazonian birds in secondary forest are similar to those in primary forest. We radio-tracked three common understory insectivore species in primary and secondary forest at the Biological Dynamics of Forest Fragments project near Manaus, Brazil: two woodcreepers, Glyphorynchus spirurus (n = 19) andXiphorhynchus pardalotus (n = 18), and the terrestrial antthrush Formicarius colma(n = 19). Forest age was a strong predictor of fidelity to a given habitat. All three species showed greater fidelity to primary forest than to 8–14-year-old secondary forest, indicating the latter’s relatively poor quality. The two woodcreeper species used 12–18-year-old secondary forest in a manner comparable to continuous forest, but F. colmaavoided moving even to 27–31-year-old secondary forest—the oldest at our site. Our results suggest that managers concerned with less sensitive species can assume that forest reserves connected by 12–18-year-old secondary forest corridors are effectively connected. On the other hand, >30 years are required after land abandonment before secondary forest serves as a primary forest-like conduit for movement by F. colma; more sensitive terrestrial insectivores may take longer still.

  4. Can physical exercise have a protective effect in an animal model of sleep-related movement disorder?

    Science.gov (United States)

    Esteves, Andrea M; Lopes, Cleide; Frank, Miriam K; Arida, Ricardo M; Frussa-Filho, Roberto; Tufik, Sergio; de Mello, Marco Túlio

    2016-05-15

    The purpose of the present study was to determine whether physical exercise (PE) has a protective effect in an experimental animal model of sleep-related movement disorder (A11 dopaminergic nuclei lesions with 6-OHDA). Rats were divided into four groups (Control PE-CTRL/PE, SHAM/PE, A11 lesion/NPE, A11 lesion/PE). Two experiments were performed: (1) the rats underwent PE before (2 weeks) and after (4 weeks) the A11 lesion; and (2) the rats underwent PE only after (4 weeks) the A11 lesion. Electrode insertion surgery was performed and sleep analyses were conducted over a period of 24h (baseline and after PE) and analyzed in 6 blocks of 4h. The results demonstrated that the A11 lesion produced an increased percentage of wakefulness in the final block of the dark period (3-7am) and a significant enhancement of the number of limb movements (LM) throughout the day. Four weeks of PE was important for reducing the number of LMs in the A11 lesion group in the rats that performed PE before and after the A11 lesion. However, in the analysis of the protective effect of PE on LM, the results showed that the number of LMs was lower at baseline in the group that had performed 2 weeks of PE prior to the A11 lesion than in the group that had not previously performed PE. In conclusion, these findings consistently demonstrate that non-pharmacological manipulations had a beneficial effect on the symptoms of sleep-related movement disorder. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Small Signal Model for VSC-HVDC Connected DFIG-Based Offshore Wind Farms

    Directory of Open Access Journals (Sweden)

    Kai Liao

    2014-01-01

    Full Text Available Large-scale offshore wind farms are integrated with onshore ac grids through the voltage source converter based high voltage direct current (VSC-HVDC transmission system. The impact on the stability of the ac grids will be significant. The small signal model of a wind farm connected with voltage source converter based dc transmission system is studied in this paper. A suitable model for small signal stability analysis is presented. The control system of wind generator and the HVDC system has also been modeled in this model for small signal stability analysis. The impact of the control parameters on the network stability is investigated.

  6. Rhythm, movement, and autism: Using rhythmic rehabilitation research as a model for autism

    Directory of Open Access Journals (Sweden)

    A. Blythe eLaGasse

    2013-03-01

    Full Text Available Recently, there has been increased focus on movement and sensory abnormalities in autism spectrum disorders (ASD. This has come from research demonstrating cortical and cerebellar difference in autism, with suggestion of early cerebellar dysfunction. As evidence for an extended profile of ASD grows, there are vast implications for treatment and therapy for individuals with autism. Persons with autism are often provided behavioral or cognitive strategies for navigating their environment; however, these strategies do not consider differences in motor functioning. One accommodation that has not yet been explored in the literature is the use of auditory rhythmic cueing to improve motor functioning in ASD. The purpose of this paper is to illustrate the potential impact of auditory rhythmic cueing for motor functioning in persons with ASD. To this effect, we review research on rhythm in motor rehabilitation, draw parallels to motor dysfunction in ASD, and propose a rationale for how rhythmic input can improve sensorimotor functioning, thereby allowing individuals with autism to demonstrate their full cognitive, behavioral, social, and communicative potential.

  7. Comparisons of orthodontic root resorption under heavy and jiggling reciprocating forces during experimental tooth movement in a rat model

    OpenAIRE

    Hikida, Takuji; Yamaguchi, Masaru; Shimizu, Mami; Kikuta, Jun; Yoshino, Tomokazu; Kasai, Kazutaka

    2016-01-01

    Objective Root mobility due to reciprocating movement of the tooth (jiggling) may exacerbate orthodontic root resorption (ORR). "Jiggling" describes mesiodistal or buccolingual movement of the roots of the teeth during orthodontic treatment. In the present study, buccolingual movement is described as "jiggling." We aimed to investigate the relationship between ORR and jiggling and to test for positive cell expression in odontoclasts in resorbed roots during experimental tooth movement (jiggli...

  8. A small-open-economy model and endogeous money stock

    Czech Academy of Sciences Publication Activity Database

    Kodera, Jan; Sladký, Karel; Vošvrda, Miloslav

    2005-01-01

    Roč. 13, č. 1 (2005), s. 27-34 ISSN 0572-3043 R&D Projects: GA ČR GA402/03/1292; GA AV ČR IAA7075202 Institutional research plan: CEZ:AV0Z10750506 Keywords : non-linear dynamic model * money market dynamics * uncovered interest rate parity Subject RIV: AH - Economics

  9. Accounting for small scale heterogeneity in ecohydrologic watershed models

    Science.gov (United States)

    Burke, W.; Tague, C.

    2017-12-01

    Spatially distributed ecohydrologic models are inherently constrained by the spatial resolution of their smallest units, below which land and processes are assumed to be homogenous. At coarse scales, heterogeneity is often accounted for by computing store and fluxes of interest over a distribution of land cover types (or other sources of heterogeneity) within spatially explicit modeling units. However this approach ignores spatial organization and the lateral transfer of water and materials downslope. The challenge is to account both for the role of flow network topology and fine-scale heterogeneity. We present a new approach that defines two levels of spatial aggregation and that integrates spatially explicit network approach with a flexible representation of finer-scale aspatial heterogeneity. Critically, this solution does not simply increase the resolution of the smallest spatial unit, and so by comparison, results in improved computational efficiency. The approach is demonstrated by adapting Regional Hydro-Ecologic Simulation System (RHESSys), an ecohydrologic model widely used to simulate climate, land use, and land management impacts. We illustrate the utility of our approach by showing how the model can be used to better characterize forest thinning impacts on ecohydrology. Forest thinning is typically done at the scale of individual trees, and yet management responses of interest include impacts on watershed scale hydrology and on downslope riparian vegetation. Our approach allow us to characterize the variability in tree size/carbon reduction and water transfers between neighboring trees while still capturing hillslope to watershed scale effects, Our illustrative example demonstrates that accounting for these fine scale effects can substantially alter model estimates, in some cases shifting the impacts of thinning on downslope water availability from increases to decreases. We conclude by describing other use cases that may benefit from this approach

  10. Phasor model of full scale converter wind turbine for small-signal stability analysis

    DEFF Research Database (Denmark)

    Ghiga, Radu; Wu, Qiuwei; Nielsen, Arne Hejde

    2017-01-01

    The small-signal stability analysis of power system electromechanical oscillations is a well-established field in control and stability assessment of power systems. The impact of large wind farms on small-signal stability of power systems has been a topic of high interest in recent years....... This study presents a phasor model of full scale converter wind turbines (WTs) implemented in MATLAB/SIMULINK for small-signal stability studies. The phasor method is typically used for dynamic studies of power systems consisting of large electric machines. It can also be applied to any linear system....... This represents an advantage in small-signal stability studies, which are based on modal analysis of the linearised model and are usually complemented with dynamic simulations. The proposed model can represent a single WT or an aggregated wind power plant. The implemented model for small-signal stability analysis...

  11. Linking movement behavior and fine-scale genetic structure to model landscape connectivity for bobcats (Lynx rufus)

    Science.gov (United States)

    Dawn M. Reding; Samuel A. Cushman; Todd E. Gosselink; William R. Clark

    2013-01-01

    Spatial heterogeneity can constrain the movement of individuals and consequently genes across a landscape, influencing demographic and genetic processes. In this study, we linked information on landscape composition, movement behavior, and genetic differentiation to gain a mechanistic understanding of how spatial heterogeneity may influence movement and gene flow of...

  12. An improved quasi-steady aerodynamic model for insect wings that considers movement of the center of pressure.

    Science.gov (United States)

    Han, Jong-Seob; Kim, Joong-Kwan; Chang, Jo Won; Han, Jae-Hung

    2015-07-30

    A quasi-steady aerodynamic model in consideration of the center of pressure (C.P.) was developed for insect flight. A dynamically scaled-up robotic hawkmoth wing was used to obtain the translational lift, drag, moment and rotational force coefficients. The translational force coefficients were curve-fitted with respect to the angles of attack such that two coefficients in the Polhamus leading-edge suction analogy model were obtained. The rotational force coefficient was also compared to that derived by the standard Kutta-Joukowski theory. In order to build the accurate pitching moment model, the locations of the C.Ps. and its movements depending on the pitching velocity were investigated in detail. We found that the aerodynamic moment model became suitable when the rotational force component was assumed to act on the half-chord. This implies that the approximation borrowed from the conventional airfoil concept, i.e., the 'C.P. at the quarter-chord' may lead to an incorrect moment prediction. In the validation process, the model showed excellent time-course force and moment estimations in comparison with the robotic wing measurement results. A fully nonlinear multibody flight dynamic simulation was conducted to check the effect of the traveling C.P. on the overall flight dynamics. This clearly showed the importance of an accurate aerodynamic moment model.

  13. Test of the movement expansion model: anticipatory vowel lip protrusion and constriction in French and English speakers.

    Science.gov (United States)

    Noiray, Aude; Cathiard, Marie-Agnès; Ménard, Lucie; Abry, Christian

    2011-01-01

    The modeling of anticipatory coarticulation has been the subject of longstanding debates for more than 40 yr. Empirical investigations in the articulatory domain have converged toward two extreme modeling approaches: a maximal anticipation behavior (Look-ahead model) or a fixed pattern (Time-locked model). However, empirical support for any of these models has been hardly conclusive, both within and across languages. The present study tested the temporal organization of vocalic anticipatory coarticulation of the rounding feature from [i] to [u] transitions for adult speakers of American English and Canadian French. Articulatory data were synchronously recorded using an Optotrak for lip protrusion and a dedicated Lip-Shape-Tracking-System for lip constriction. Results show that (i) protrusion is an inconsistent parameter for tracking anticipatory rounding gestures across individuals, more specifically in English; (ii) labial constriction (between-lip area) is a more reliable correlate, allowing for the description of vocalic rounding in both languages; (iii) when tested on the constriction component, speakers show a lawful anticipatory behavior expanding linearly as the intervocalic consonant interval increases from 0 to 5 consonants. The Movement Expansion Model from Abry and Lallouache [(1995a) Bul. de la Comm. Parlée 3, 85-99; (1995b) Proceedings of ICPHS 4, 152-155.] predicted such a regular behavior, i.e., a lawful variability with a speaker-specific expansion rate, which is not language-specific.

  14. A comparison of the lubrication behavior of whey protein model foods using tribology in linear and elliptical movement.

    Science.gov (United States)

    Campbell, Caroline L; Foegeding, E Allen; van de Velde, Fred

    2017-08-01

    Lubrication is an important factor in the sensory evaluation of food products. Tribology provides a theoretical framework and instrumental methods for evaluating frictional properties between two moving surfaces and the lubrication behavior of products between these surfaces. Relating frictional measurements to sensory properties detected during oral processing requires careful and pertinent choices in surface materials and testing conditions. The aims of this study were to investigate: (a) differences in lubrication behavior of a range of food textures and (b) the differences between linear and elliptical movement and added saliva to understand the contribution of food structure to friction. Six whey protein model food samples, ranging in texture from fluid to semisolid to soft solid, were analyzed using a pin on disk tribometer to determine the coefficient of friction (COF) across a range of sliding speeds. The samples were analyzed in their initial form and post-oral processing (n = 4) in both linear and elliptical movements. Elliptical movement slightly decreased coefficients of friction and extended the shape of the friction curve. Increases in test food viscosity decreased the COF but differences in viscosity were not apparent when test foods were mixed with saliva. Data correction for viscosity shifted the friction curves horizontally, indicating that lubrication had a greater impact upon friction than viscosity. This study provides initial insights for further comparison of linear and elliptical movement with a variety of sample compositions. Sensory perception of smoothness and creaminess are often major contributors to overall hedonic food liking and are a major reason why products high in fat and sugar are more highly preferred over other foods. These parameters are influenced by friction and lubrication between the tongue, palate, teeth, food products, and saliva during oral processing. Tribology provides an instrumental method to evaluate friction

  15. Foundations in Elementary Education: Movement.

    Science.gov (United States)

    Weikart, Phyllis S.; Carlton, Elizabeth B.

    The eight chapters in this book explain a teaching model to help students develop their kinesthetic intelligence through purposeful movement education. The major focus is the kindergarten through third grade child, but because in movement one can be a "beginner" at any age, movement experiences of both older and younger learners are occasionally…

  16. Individuality of movements in music--finger and body movements during playing of the flute.

    Science.gov (United States)

    Albrecht, Stefan; Janssen, Daniel; Quarz, Esther; Newell, Karl M; Schöllhorn, Wolfgang I

    2014-06-01

    The achievement of mastery in playing a composition by means of a musical instrument typically requires numerous repetitions and corrections according to the keys and notations of the music piece. Nevertheless, differences in the interpretation of the same music piece by highly skilled musicians seem to be recognizable. The present study investigated differences within and between skilled flute players in their finger and body movements playing the same piece several times on the same and on different days. Six semiprofessional and four professional musicians played an excerpt of Mozart's Flute Concerto No. 2 several times on three different days. Finger and body movements were recorded by 3D motion capture and analyzed by linear and nonlinear classification approaches. The findings showed that the discrete and continuous movement timing data correctly identified individuals up to 100% by means of their finger movements and up to 94% by means of their body movements. These robust examples of identifying individual movement patterns contradict the prevailing models of small, economic finger movements that are favored in the didactic literature for woodwind players and question traditional recommendations for teaching the learning of motor skills. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Movement timing and invariance arise from several geometries.

    Directory of Open Access Journals (Sweden)

    Daniel Bennequin

    2009-07-01

    Full Text Available Human movements show several prominent features; movement duration is nearly independent of movement size (the isochrony principle, instantaneous speed depends on movement curvature (captured by the 2/3 power law, and complex movements are composed of simpler elements (movement compositionality. No existing theory can successfully account for all of these features, and the nature of the underlying motion primitives is still unknown. Also unknown is how the brain selects movement duration. Here we present a new theory of movement timing based on geometrical invariance. We propose that movement duration and compositionality arise from cooperation among Euclidian, equi-affine and full affine geometries. Each geometry posses a canonical measure of distance along curves, an invariant arc-length parameter. We suggest that for continuous movements, the actual movement duration reflects a particular tensorial mixture of these canonical parameters. Near geometrical singularities, specific combinations are selected to compensate for time expansion or compression in individual parameters. The theory was mathematically formulated using Cartan's moving frame method. Its predictions were tested on three data sets: drawings of elliptical curves, locomotion and drawing trajectories of complex figural forms (cloverleaves, lemniscates and limaçons, with varying ratios between the sizes of the large versus the small loops. Our theory accounted well for the kinematic and temporal features of these movements, in most cases better than the constrained Minimum Jerk model, even when taking into account the number of estimated free parameters. During both drawing and locomotion equi-affine geometry was the most dominant geometry, with affine geometry second most important during drawing; Euclidian geometry was second most important during locomotion. We further discuss the implications of this theory: the origin of the dominance of equi-affine geometry, the possibility

  18. Movement Timing and Invariance Arise from Several Geometries

    Science.gov (United States)

    Bennequin, Daniel; Fuchs, Ronit; Berthoz, Alain; Flash, Tamar

    2009-01-01

    Human movements show several prominent features; movement duration is nearly independent of movement size (the isochrony principle), instantaneous speed depends on movement curvature (captured by the 2/3 power law), and complex movements are composed of simpler elements (movement compositionality). No existing theory can successfully account for all of these features, and the nature of the underlying motion primitives is still unknown. Also unknown is how the brain selects movement duration. Here we present a new theory of movement timing based on geometrical invariance. We propose that movement duration and compositionality arise from cooperation among Euclidian, equi-affine and full affine geometries. Each geometry posses a canonical measure of distance along curves, an invariant arc-length parameter. We suggest that for continuous movements, the actual movement duration reflects a particular tensorial mixture of these canonical parameters. Near geometrical singularities, specific combinations are selected to compensate for time expansion or compression in individual parameters. The theory was mathematically formulated using Cartan's moving frame method. Its predictions were tested on three data sets: drawings of elliptical curves, locomotion and drawing trajectories of complex figural forms (cloverleaves, lemniscates and limaçons, with varying ratios between the sizes of the large versus the small loops). Our theory accounted well for the kinematic and temporal features of these movements, in most cases better than the constrained Minimum Jerk model, even when taking into account the number of estimated free parameters. During both drawing and locomotion equi-affine geometry was the most dominant geometry, with affine geometry second most important during drawing; Euclidian geometry was second most important during locomotion. We further discuss the implications of this theory: the origin of the dominance of equi-affine geometry, the possibility that the brain

  19. Measuring the Effect of Exchange Rate Movements on Stock Market Returns Volatility: GARCH Model

    Directory of Open Access Journals (Sweden)

    Abdelkadir BESSEBA

    2017-06-01

    Full Text Available This paper aims to investigate the dynamic links between exchange rate fluctuations and stock market return volatility. For this purpose, we have employed a Generalized Autoregressive Conditional Heteroscedasticity model (GARCH model. Stock market returns sensitivities are found to be stronger for exchange rates, implying that exchange rate change plays an important role in determining the dynamics of the stock market returns.

  20. Infection dynamics on spatial small-world network models

    Science.gov (United States)

    Iotti, Bryan; Antonioni, Alberto; Bullock, Seth; Darabos, Christian; Tomassini, Marco; Giacobini, Mario

    2017-11-01

    The study of complex networks, and in particular of social networks, has mostly concentrated on relational networks, abstracting the distance between nodes. Spatial networks are, however, extremely relevant in our daily lives, and a large body of research exists to show that the distances between nodes greatly influence the cost and probability of establishing and maintaining a link. A random geometric graph (RGG) is the main type of synthetic network model used to mimic the statistical properties and behavior of many social networks. We propose a model, called REDS, that extends energy-constrained RGGs to account for the synergic effect of sharing the cost of a link with our neighbors, as is observed in real relational networks. We apply both the standard Watts-Strogatz rewiring procedure and another method that conserves the degree distribution of the network. The second technique was developed to eliminate unwanted forms of spatial correlation between the degree of nodes that are affected by rewiring, limiting the effect on other properties such as clustering and assortativity. We analyze both the statistical properties of these two network types and their epidemiological behavior when used as a substrate for a standard susceptible-infected-susceptible compartmental model. We consider and discuss the differences in properties and behavior between RGGs and REDS as rewiring increases and as infection parameters are changed. We report considerable differences both between the network types and, in the case of REDS, between the two rewiring schemes. We conclude that REDS represent, with the application of these rewiring mechanisms, extremely useful and interesting tools in the study of social and epidemiological phenomena in synthetic complex networks.

  1. Neurovascular modeling: small-batch manufacturing of silicone vascular replicas.

    Science.gov (United States)

    Chueh, J Y; Wakhloo, A K; Gounis, M J

    2009-06-01

    Realistic, population based cerebrovascular replicas are required for the development of neuroendovascular devices. The objective of this work was to develop an efficient methodology for manufacturing realistic cerebrovascular replicas. Brain MR angiography data from 20 patients were acquired. The centerline of the vasculature was calculated, and geometric parameters were measured to describe quantitatively the internal carotid artery (ICA) siphon. A representative model was created on the basis of the quantitative measurements. Using this virtual model, we designed a mold with core-shell structure and converted it into a physical object by fused-deposit manufacturing. Vascular replicas were created by injection molding of different silicones. Mechanical properties, including the stiffness and luminal coefficient of friction, were measured. The average diameter, length, and curvature of the ICA siphon were 4.15 +/- 0.09 mm, 22.60 +/- 0.79 mm, and 0.34 +/- 0.02 mm(-1) (average +/- standard error of the mean), respectively. From these image datasets, we created a median virtual model, which was transformed into a physical replica by an efficient batch-manufacturing process. The coefficient of friction of the luminal surface of the replica was reduced by up to 55% by using liquid silicone rubber coatings. The modulus ranged from 0.67 to 1.15 MPa compared with 0.42 MPa from human postmortem studies, depending on the material used to make the replica. Population-representative, smooth, and true-to-scale silicone arterial replicas with uniform wall thickness were successfully built for in vitro neurointerventional device-testing by using a batch-manufacturing process.

  2. Analysing Possible Applications for Available Mathematical Models of Tracked Vehicle Movement Over the Rough Terrain to Examine Tracked Chain Dynamic Processes

    Directory of Open Access Journals (Sweden)

    M. E. Lupyan

    2014-01-01

    Full Text Available The article offered for consideration provides a survey of methods to study a tracked vehicle movement over unpaved grounds and obstacles using various software systems. The relevant issue is to optimize chassis elements of a caterpillar at the design stage. The challenges, engineers face using different methods to study the tracked vehicle elements, are given. Advantages of using simulation to study a state of the various components of the loaded chassis are described. Beside, an important and relevant issue is brought up i.e. modeling a vehicle movement in real time.While writing an article, different modeling methods for an interaction between a tracked vehicle chassis and an underlying subgrade used both in domestic and in foreign practice have been analysed. The applied analytical assumptions in creating these models and their basic elements are described. The way to specify an interaction between the track and road wheels of a caterpillar, crawler belt specification, and interaction between its elements have been analysed in detail as well. Special attention was also paid to the various ways of specifying the subgrade both in planar models and in models enabling us to study all chassis elements of a caterpillar as a whole.In addition to the classical simulation of tracked vehicle movement used to analyse Ride qualities of tracked vehicle and loaded state of various chassis elements, is offered a model used to simulate a movement coil in real time.The article presents advantages and disadvantages of different models of movement in terms of engineering analysis of caterpillar elements. A task to develop a simulation model of caterpillar movement is set. Requirements for a model in case of its use in engineering analysis of chassis elements of a caterpillar are defined. A problem of a lack of the single technique to conduct engineering analysis of tracked vehicle chassis is noted. 

  3. Protest movements

    International Nuclear Information System (INIS)

    Rucht, D.

    1989-01-01

    The author describes the development of protest movements in postwar Germay and outlines two essential overlapping 'flow cycles'. The first of these was characterised by the restaurative postwar years. It culminated and ended in the students' revolt. This revolt is at the same time the start of a second cycle of protest which encompasses all subsequent individual movement and is initated by an economic, political and sociocultural procrastination of modernisation. This cycle culminates in the late 70s and early 80s and clearly lost momentum over the last few years. The follwoing phases and themes are described profoundly: against restauration and armament in the 1950; the revolutionary impatience of the students' movement, politisation of everyday life by the womens' movement and citizens' action groups, antinuclear- and ecological movement, differentiation and stabilisation of the movement in the 70s and 80s; break-up and continuity in the German protest behaviour. The paper contains a detailed chronicle of protest activities since 1945. (orig.) [de

  4. Spherical sector model for describing the experimental small-angle neutron scattering data for dendrimers

    International Nuclear Information System (INIS)

    Rogachev, A. V.; Cherny, A. Yu.; Ozerin, A. N.; Gordeliy, V. I.; Kuklin, A. I.

    2007-01-01

    A new model for interpreting the results of small-angle neutron scattering from dendrimer solutions is proposed. The mathematical description is given and the theoretical small-angle scattering curves for spherical sectors with different parameters are presented. It is shown that the model proposed is in good agreement with the experimental results. Comparison of the experimental small-angle neutron scattering curves for polyallylcarbosilane dendrimers of the ninth generation with model scattering curves suggests that the inner dendrimer sphere is permeable to a solvent whose density is lower than the density of the solvent beyond the dendrimer by a factor of at least 2

  5. New Indicated Mean Effective Pressure (IMEP) model for predicting crankshaft movement

    International Nuclear Information System (INIS)

    Omran, Rabih; Younes, Rafic; Champoussin, Jean-Claude; Outbib, Rachid

    2011-01-01

    Highlights: → IMEP is essential to estimate the indicated torque in internal combustion engine. → We proposed model which describes the IMEP-Low pressure and the IMEP-High pressure. → We studied the evolution of the IMEP with respect to the engine's variables. → We deduced the variables of influence that can be used to develop the models. → The IMEP model is compared to transient experimental New European Driving Cycle. - Abstract: Indicated Mean Effective Pressure models (IMEP) are essential to estimate the indicated torque in internal combustion engine; they also provide important information about the mechanical efficiency of the engine thermodynamic cycle which describes the conversion of the fuel combustion energy into mechanical work. In the past, many researches were made to improve the IMEP prediction and measurement techniques at different engine operating conditions. In this paper, we proposed a detailed IMEP model which separately describes the IMEP-Low pressure and the IMEP-High pressure of a modern diesel engine; the IMEP is the direct subtraction result between these two variables. We firstly studied the evolution of the IMEP HP and IMEP LP with respect to the engine's variables and then we deduced the variables of influence and the form of the equations that can be used to develop the models. Finally, the models' coefficients were determined based on experimental data collected on a steady state test bench and using the least square regression method. In addition, the IMEP HP model results were compared to transient experimental data collected on a chassis dynamometer test bench; the model results are in excellent agreement with the experimental data.

  6. The small intestine and irritable bowel syndrome (IBS): a batch process model.

    Science.gov (United States)

    Dobson, Brian C

    2008-11-01

    Faults in a batch process model of the small intestine create the symptoms of all types of irritable bowel syndrome. The model has three sequential processing sections corresponding to the natural divisions of the intestine. It is governed by a brain controller that is divided into four sub-controllers, each with a unique neurotransmitter. Each section has a sub-controller to manage transport. Sensors in the walls of the intestine provide input and output goes to the muscles lining the walls of the intestine. The output controls the speed of the food soup, moves it in both directions, mixes it, controls absorption, and transfers it to the next section at the correct speed (slow). The fourth sub-controller manages the addition of chemicals. It obtains input from the first section of the process via the signalling hormone Cholecystokinin and sends output to the muscles that empty the gall bladder and pancreas. The correct amounts of bile salts and enzymes are then added to the first section. The sub-controllers produce output only when input is received. When output is missing the enteric nervous system applies a default condition. This default condition normally happens when no food is in the intestine. If food is in the intestine and a transport sub-controller fails to provide output then the default condition moves the food soup to the end of that section. The movement is in one direction only (forward), at a speed dependent on the amount and type of fibre present. Cereal, bean and vegetable fibre causes high speeds. This default high speed transport causes irritable bowel syndrome. A barrier is created when a section moving fast at the default speed, precedes a section controlled by a transport sub-controller. Then the sub-controller constricts the intestine to stop the fast flow. The barrier causes constipation, cramping, and bloating. Diarrhoea results when the section terminating the process moves at the fast default speed. Two problems can occur to prevent

  7. Mental imagery of speech and movement implicates the dynamics of internal forward models

    Directory of Open Access Journals (Sweden)

    Xing eTian

    2010-10-01

    Full Text Available The classical concept of efference copies in the context of internal forward models has stimulated productive research in cognitive science and neuroscience. There are compelling reasons to argue for such a mechanism, but finding direct evidence in the human brain remains difficult. Here we investigate the dynamics of internal forward models from an unconventional angle: mental imagery, assessed while recording high temporal resolution neuronal activity using magnetoencephalography (MEG. We compare two overt and covert tasks; our covert, mental imagery tasks are unconfounded by overt input/output demands – but in turn necessitate the development of appropriate multi-dimensional topographic analyses. Finger tapping (studies 1-2 and speech experiments (studies 3-5 provide temporally constrained results that implicate the estimation of an efference copy. We suggest that one internal forward model over parietal cortex subserves the kinesthetic feeling in motor imagery. Secondly, observed auditory neural activity ~170 ms after motor estimation in speech experiments (studies 3-5 demonstrates the anticipated auditory consequences of planned motor commands in a second internal forward model in imagery of speech production. Our results provide neurophysiological evidence from the human brain in favor of internal forward models deploying efference copies in somatosensory and auditory cortex, in finger tapping and speech production tasks, respectively, and also suggest the dynamics and sequential updating structure of internal forward models.

  8. Model structure of the stream salmonid simulator (S3)—A dynamic model for simulating growth, movement, and survival of juvenile salmonids

    Science.gov (United States)

    Perry, Russell W.; Plumb, John M.; Jones, Edward C.; Som, Nicholas A.; Hetrick, Nicholas J.; Hardy, Thomas B.

    2018-04-06

    Fisheries and water managers often use population models to aid in understanding the effect of alternative water management or restoration actions on anadromous fish populations. We developed the Stream Salmonid Simulator (S3) to help resource managers evaluate the effect of management alternatives on juvenile salmonid populations. S3 is a deterministic stage-structured population model that tracks daily growth, movement, and survival of juvenile salmon. A key theme of the model is that river flow affects habitat availability and capacity, which in turn drives density dependent population dynamics. To explicitly link population dynamics to habitat quality and quantity, the river environment is constructed as a one-dimensional series of linked habitat units, each of which has an associated daily time series of discharge, water temperature, and usable habitat area or carrying capacity. The physical characteristics of each habitat unit and the number of fish occupying each unit, in turn, drive survival and growth within each habitat unit and movement of fish among habitat units.The purpose of this report is to outline the underlying general structure of the S3 model that is common among different applications of the model. We have developed applications of the S3 model for juvenile fall Chinook salmon (Oncorhynchus tshawytscha) in the lower Klamath River. Thus, this report is a companion to current application of the S3 model to the Trinity River (in review). The general S3 model structure provides a biological and physical framework for the salmonid freshwater life cycle. This framework captures important demographics of juvenile salmonids aimed at translating management alternatives into simulated population responses. Although the S3 model is built on this common framework, the model has been constructed to allow much flexibility in application of the model to specific river systems. The ability for practitioners to include system-specific information for the

  9. Modeling amphibian energetics, habitat suitability, and movements of western toads, Anaxyrus (=Bufo) boreas, across present and future landscapes

    Science.gov (United States)

    Bartelt, Paul E.; Klaver, Robert W.; Porter, Warren P.

    2010-01-01

    Effective conservation of amphibian populations requires the prediction of how amphibians use and move through a landscape. Amphibians are closely coupled to their physical environment. Thus an approach that uses the physiological attributes of amphibians, together with knowledge of their natural history, should be helpful. We used Niche Mapper™ to model the known movements and habitat use patterns of a population of Western toads (Anaxyrus (=Bufo) boreas) occupying forested habitats in southeastern Idaho. Niche Mapper uses first principles of environmental biophysics to combine features of topography, climate, land cover, and animal features to model microclimates and animal physiology and behavior across landscapes. Niche Mapper reproduced core body temperatures (Tc) and evaporation rates of live toads with average errors of 1.6 ± 0.4 °C and 0.8 ± 0.2 g/h, respectively. For four different habitat types, it reproduced similar mid-summer daily temperature patterns as those measured in the field and calculated evaporation rates (g/h) with an average error rate of 7.2 ± 5.5%. Sensitivity analyses indicate these errors do not significantly affect estimates of food consumption or activity. Using Niche Mapper we predicted the daily habitats used by free-ranging toads; our accuracy for female toads was greater than for male toads (74.2 ± 6.8% and 53.6 ± 15.8%, respectively), reflecting the stronger patterns of habitat selection among females. Using these changing to construct a cost surface, we also reconstructed movement paths that were consistent with field observations. The effect of climate warming on toads depends on the interaction of temperature and atmospheric moisture. If climate change occurs as predicted, results from Niche Mapper suggests that climate warming will increase the physiological cost of landscapes thereby limiting the activity for toads in different habitats.

  10. Development of a simple force prediction model and consistency assessment of knee movements in ten-pin bowling

    Directory of Open Access Journals (Sweden)

    Li-Cheng Hsieh

    2012-08-01

    Full Text Available The aim of this research is to use LabVIEW to help bowlers understand theirjoint movements, forces acting on their joints, and the consistency of their knee movements while competing in ten-pin bowling. Kinetic and kinematic data relating to the lower limbs were derived from bowlers’ joint angles and the joint forces were calculated from the Euler angles using the inverse dynamics method with Newton-Euler equations. An artificial-neural-network (ANN-based data-driven model for predicting knee forces using the Euler angles was developed. This approach allows for the collection of data inbowling alleys without the use of force plates. Correlation coefficients were computed after ANN training and all values exceeded 0.9. This result implies a strong correlation between the joint angles and forces. Furthermore, the predicted 3D forces (obtained from ANN simulations and the measured forces (obtained from force plates via the inverse dynamics method are strongly correlated. The agreement between the predicted andmeasured forces was evaluated by the coefficient of determination (R2, which reflects the bowler’s consistency and steadiness of the bowling motion at the knee. The R2 value was beneficial in assessing the consistency of the bowling motion. An R2 value close to 1 implies a more consistent sliding motion. This research enables the prediction of the forceson the knee during ten-pin bowling by ANN simulations using the measured knee angles. Consequently, coaches and bowlers can use the developed ANN model and the analysis module to improve bowling motion.

  11. A Mathematical Model of the Human Small Intestine Following Acute Radiation and Burn Exposures

    Science.gov (United States)

    2016-08-01

    intestinal lumen Cell Migration Radiation damages proliferating crypt cells, causing mitotic arrest and delaying regeneration Burns can...04-08-2016 Technical Report A Mathematical Model of the Human Small Intestine Following Acute Radiation and Burn Exposures HDTRA1...the small intestine , reducing the density of the gut barrier. A reduced epithelial lining can result in suppressed nutrient absorption, bacterial

  12. The Accuracy of Inference in Small Samples of Dynamic Panel Data Models

    NARCIS (Netherlands)

    Bun, M.J.G.; Kiviet, J.F.

    2001-01-01

    Through Monte Carlo experiments the small sample behavior is examined of various inference techniques for dynamic panel data models when both the time-series and cross-section dimensions of the data set are small. The LSDV technique and corrected versions of it are compared with IV and GMM

  13. Central nervous system radiation injury in small animal models

    International Nuclear Information System (INIS)

    Kogel, A.J. van der

    1991-01-01

    Experimental studies on radiation injury in the central nervous system have been carried out in many species ranging from mouse to monkey. This review is restricted to studies in rodents irradiated with low linear energy transfer (LET) radiation. In this paper, the various rodent models of brain and spinal cord injury are described with particular emphasis on the pathology of different types of lesions and theories of their pathogenesis. Many of the initial studies were limited to relatively high single doses, but in later work more clinically relevant fractionated irradiation schemes were employed. This has led to the recognition of various types of early and late delayed injury that are analogous to the syndromes observed in humans. Two main pathways have been suggested for the pathogenesis, one involving predominantly the progressive loss of glial cells and the other involving vascular injury. The relative importance of both mechanisms will be discussed with respect to treatment conditions and to dose level in particular. An hypothesis is presented concerning the possible role of different cell types in the development of specific syndromes

  14. [Comparison between the Range of Movement Canine Real Cervical Spine and Numerical Simulation - Computer Model Validation].

    Science.gov (United States)

    Srnec, R; Horák, Z; Sedláček, R; Sedlinská, M; Krbec, M; Nečas, A

    2017-01-01

    PURPOSE OF THE STUDY In developing new or modifying the existing surgical treatment methods of spine conditions an integral part of ex vivo experiments is the assessment of mechanical, kinematic and dynamic properties of created constructions. The aim of the study is to create an appropriately validated numerical model of canine cervical spine in order to obtain a tool for basic research to be applied in cervical spine surgeries. For this purpose, canine is a suitable model due to the occurrence of similar cervical spine conditions in some breeds of dogs and in humans. The obtained model can also be used in research and in clinical veterinary practice. MATERIAL AND METHODS In order to create a 3D spine model, the LightSpeed 16 (GE, Milwaukee, USA) multidetector computed tomography was used to scan the cervical spine of Doberman Pinscher. The data were transmitted to Mimics 12 software (Materialise HQ, Belgium), in which the individual vertebrae were segmented on CT scans by thresholding. The vertebral geometry was exported to Rhinoceros software (McNeel North America, USA) for modelling, and subsequently the specialised software Abaqus (Dassault Systemes, France) was used to analyse the response of the physiological spine model to external load by the finite element method (FEM). All the FEM based numerical simulations were considered as nonlinear contact statistic tasks. In FEM analyses, angles between individual spinal segments were monitored in dependence on ventroflexion/ /dorziflexion. The data were validated using the latero-lateral radiographs of cervical spine of large breed dogs with no evident clinical signs of cervical spine conditions. The radiographs within the cervical spine range of motion were taken at three different positions: in neutral position, in maximal ventroflexion and in maximal dorziflexion. On X-rays, vertebral inclination angles in monitored spine positions were measured and compared with the results obtain0ed from FEM analyses of the

  15. Simulation of water movement and isoproturon behaviour in a heavy clay soil using the MACRO model

    Directory of Open Access Journals (Sweden)

    T. J. Besien

    1997-01-01

    Full Text Available In this paper, the dual-porosity MACRO model has been used to investigate methods of reducing leaching of isoproturon from a structured heavy clay soil. The MACRO model was applied to a pesticide leaching data-set generated from a plot scale experiment on a heavy clay soil at the Oxford University Farm, Wytham, England. The field drain was found to be the most important outflow from the plot in terms of pesticide removal. Therefore, this modelling exercise concentrated on simulating field drain flow. With calibration of field-saturated and micropore saturated hydraulic conductivity, the drain flow hydrographs were simulated during extended periods of above average rainfall, with both the hydrograph shape and peak flows agreeing well. Over the whole field season, the observed drain flow water budget was well simulated. However, the first and second drain flow events after pesticide application were not simulated satisfactorily. This is believed to be due to a poor simulation of evapotranspiration during a period of low rainfall around the pesticide application day. Apart from an initial rapid drop in the observed isoproturon soil residue, the model simulated isoproturon residues during the 100 days after pesticide application reasonably well. Finally, the calibrated model was used to show that changes in agricultural practice (deep ploughing, creating fine consolidated seed beds and organic matter applications could potentially reduce pesticide leaching to surface waters by up to 60%.

  16. Simulating Salt Movement using a Coupled Salinity Transport Model in a Variably Saturated Agricultural Groundwater System

    Science.gov (United States)

    Tavakoli Kivi, S.; Bailey, R. T.; Gates, T. K.

    2017-12-01

    Salinization is one of the major concerns in irrigated agricultural fields. Increasing salinity concentrations are due principally to a high water table that results from excessive irrigation, canal seepage, and a lack of efficient drainage systems, and lead to decreasing crop yield. High groundwater salinity loading to nearby river systems also impacts downstream areas, with saline river water diverted for application on irrigated fields. To assess the different strategies for salt remediation, we present a reactive transport model (UZF-RT3D) coupled with a salinity equilibrium chemistry module for simulating the fate and transport of salt ions in a variably-saturated agricultural groundwater system. The developed model accounts not for advection, dispersion, nitrogen and sulfur cycling, oxidation-reduction, sorption, complexation, ion exchange, and precipitation/dissolution of salt minerals. The model is applied to a 500 km2 region within the Lower Arkansas River Valley (LARV) in southeastern Colorado, an area acutely affected by salinization in the past few decades. The model is tested against salt ion concentrations in the saturated zone, total dissolved solid concentrations in the unsaturated zone, and salt groundwater loading to the Arkansas River. The model now can be used to investigate salinity remediation strategies.

  17. Stable phase-shift despite quasi-rhythmic movements: a CPG-driven dynamic model of active tactile exploration in an insect

    Directory of Open Access Journals (Sweden)

    Nalin eHarischandra

    2015-08-01

    Full Text Available An essential component of autonomous and flexible behaviour in animals is active exploration of the environment, allowing for perception-guided planning and control of actions. An important sensory system involved is active touch. Here, we introduce a general modelling framework of Central Pattern Generators (CPGs for movement generation in active tactile exploration behaviour. The CPG consists of two network levels: (i phase-coupled Hopf oscillators for rhythm generation, and (ii pattern formation networks for capturing the frequency and phase characteristics of individual joint oscillations. The model captured the natural, quasi-rhythmic joint kinematics as observed in coordinated antennal movements of walking stick insects. Moreover, it successfully produced tactile exploration behaviour on a three-dimensional skeletal model of the insect antennal system with physically realistic parameters. The effect of proprioceptor ablations could be simulated by changing the amplitude and offset parameters of the joint oscillators, only. As in the animal, the movement of both antennal joints was coupled with a stable phase difference, despite the quasi-rhythmicity of the joint angle time courses. We found that the phase-lead of the distal scape-pedicel joint relative to the proximal head-scape joint was essential for producing the natural tactile exploration behaviour and, thus, for tactile efficiency. For realistic movement patterns, the phase-lead could vary within a limited range of 10 to 30 degrees only. Tests with artificial movement patterns strongly suggest that this phase sensitivity is not a matter of the frequency composition of the natural movement pattern. Based on our modelling results, we propose that a constant phase difference is coded into the CPG of the antennal motor system and that proprioceptors are acting locally to regulate the joint movement amplitude.

  18. Modelling and Analysis on Biomechanical Dynamic Characteristics of Knee Flexion Movement under Squatting

    Directory of Open Access Journals (Sweden)

    Jianping Wang

    2014-01-01

    Full Text Available The model of three-dimensional (3D geometric knee was built, which included femoral-tibial, patellofemoral articulations and the bone and soft tissues. Dynamic finite element (FE model of knee was developed to simulate both the kinematics and the internal stresses during knee flexion. The biomechanical experimental system of knee was built to simulate knee squatting using cadaver knees. The flexion motion and dynamic contact characteristics of knee were analyzed, and verified by comparing with the data from in vitro experiment. The results showed that the established dynamic FE models of knee are capable of predicting kinematics and the contact stresses during flexion, and could be an efficient tool for the analysis of total knee replacement (TKR and knee prosthesis design.

  19. Modelling of redox front and uranium movement in a uranium mine at Pocos de Caldas, Brazil

    International Nuclear Information System (INIS)

    Cross, J.E.; Gabriel, D.S.; Haworth, A.; Sharland, S.M.; Tweed, C.J.

    1991-04-01

    A study of the migration of uranium at the Pocos de Caldas uranium mine in Brazil under the influence of the infiltration of oxidising groundwaters has been performed. The modelling was carried out using the coupled chemical equilibria/transport code CHEQMATE. The work presented in this paper extends a previous study. Results give some encouraging agreements with field data, generally increasing confidence in the use of such modelling techniques in problems associated with the migration of radionuclides away from a nuclear waste repository. For particular aspects of the problem where good agreement with field data was not obtained, a number of reasons have been suggested. This study also highlights the importance of accurate thermodynamic data and choice of solubility-limiting mineral phases for modelling such systems. (author)

  20. Learning and production of movement sequences: Behavioral, neurophysiological, and modelling perspectives.

    NARCIS (Netherlands)

    Rhodes, Bradley J.; Bullock, Daniel; Verwey, Willem B.; Averbeck, Bruno B.; Page, Michael P.A.

    2004-01-01

    A wave of recent behavioral studies has generated a new wealth of parametric observations about serial order behavior. What was a trickle of neurophysiological studies has grown to a steady stream of probes of neural sites and mechanisms underlying sequential behavior. Moreover, simulation models of

  1. Validation of Nonlinear Bipolar Transistor Model by Small-Signal Measurements

    DEFF Research Database (Denmark)

    Vidkjær, Jens; Porra, V.; Zhu, J.

    1992-01-01

    A new method for the validity analysis of nonlinear transistor models is presented based on DC-and small-signal S-parameter measurements and realistic consideration of the measurement and de-embedding errors and singularities of the small-signal equivalent circuit. As an example, some analysis...... results for an extended Gummel Poon model are presented in the case of a UHF bipolar power transistor....

  2. Automatic generation of zonal models to study air movement and temperature distribution in buildings; Generation automatique de modeles zonaux pour l'etude du comportement thermo-aeraulique des batiments

    Energy Technology Data Exchange (ETDEWEB)

    Musy, M.

    1999-07-01

    This study consists in showing that it is possible to automatically build zonal models that allow to predict air movement, temperature distribution and air quality in the whole building. Zonal models are based on a rough partitioning of the rooms. It is an intermediate approach between one-node models and CFD models. One-node models consider an homogeneous temperature in each room, and for that reason, do not permit to predict the thermal comfort in a room whereas CFD models require a great amount of simulation time To achieve this aim, the zonal model was entirely reformulated as the connection of small sets of equations. The equations describe, either the state of a sub-zone of the partitioning (such sets of equations are called 'cells'), or mass and energy transfers that occur between two sub-zones (then, they are called 'interfaces'). There are various 'cells' and 'interfaces' to represent different air flows that occur in buildings. They all have been translated into SPARK objects that form a model library. Building a simulation consists in choosing the appropriate models to represent the rooms, and connecting them. The last stage has been automated. So, the only thing the user has to do is to give the partitioning and to choose the models to be implemented. The resulting set of equations is solved iteratively with SPARK. Results of simulations in 3D-rooms are presented and compared with experimental data. examples of zonal models are also given. They are applied to the study of a group of two rooms, a building, and a room the geometry of which is complex. (author)

  3. Research on Three-dimensional Motion History Image Model and Extreme Learning Machine for Human Body Movement Trajectory Recognition

    Directory of Open Access Journals (Sweden)

    Zheng Chang

    2015-01-01

    Full Text Available Based on the traditional machine vision recognition technology and traditional artificial neural networks about body movement trajectory, this paper finds out the shortcomings of the traditional recognition technology. By combining the invariant moments of the three-dimensional motion history image (computed as the eigenvector of body movements and the extreme learning machine (constructed as the classification artificial neural network of body movements, the paper applies the method to the machine vision of the body movement trajectory. In detail, the paper gives a detailed introduction about the algorithm and realization scheme of the body movement trajectory recognition based on the three-dimensional motion history image and the extreme learning machine. Finally, by comparing with the results of the recognition experiments, it attempts to verify that the method of body movement trajectory recognition technology based on the three-dimensional motion history image and extreme learning machine has a more accurate recognition rate and better robustness.

  4. The Impact of Surface Bending, A Complete Mineralogical Model and Movement of the Overriding Plate on Subduction Zones

    Science.gov (United States)

    Arredondo, Katrina Marie

    Modern observations of subduction zones provide only snapshots of a complex geologic system that can last tens of millions of years. Surface velocity measurements and seismic tomography images provide information on the possible forces acting on the plate and influencing slab shape and behavior. Modern subduction zones exhibit a wide range of behavior, from the rapidly rolling back Tonga subduction zone (where the trench is moving toward the subducting plate) to stationary trenches to trench advance (where the trench is moving toward the overriding plate). Slabs may also stagnate at 660 km while others directly penetrate into the lower mantle. Numerical models can combine observations and laboratory data to test and study possible forces that may explain the wide variety of behavior observed in modern subduction zones. Past numerical model studies have not studied the impact on subduction zone behavior from: composition-dependent phase transitions, a complete mineralogical model and movement of the overriding plate. Here we show that: 1) weakening of the subducting plate can be observed from the forebulge to the trench using highly detailed bathymetry and gravity measurement tracks parallel to the trench, 2) using a complete mineralogy model is important for accurate numerical models because incomplete approximations may overestimate slab stagnation and slab rollback, 3) in free subduction models, the complete mineralogy model creates a strong feedback loop between broad slab folds and trench velocities, and 4) the movement of the overriding plate is very important for slab rollback. Results presented in Chapter 1 indicate that the rheology in the numerical models should produce weakening in the slab as it bends into the trench, which is observed in the models of Chapter 2 and 3. Past published models can be analyzed in relation to Chapter 2 and 3 to determine if their conclusions are skewed by an overestimation of slab stagnation or trench rollback. The presented

  5. MATHEMATICAL AND COMPUTATIONAL MODELLING OF RIBOSOMAL MOVEMENT AND PROTEIN SYNTHESIS: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    Tobias von der Haar

    2012-04-01

    Full Text Available Translation or protein synthesis consists of a complex system of chemical reactions, which ultimately result in decoding of the mRNA and the production of a protein. The complexity of this reaction system makes it difficult to quantitatively connect its input parameters (such as translation factor or ribosome concentrations, codon composition of the mRNA, or energy availability to output parameters (such as protein synthesis rates or ribosome densities on mRNAs. Mathematical and computational models of translation have now been used for nearly five decades to investigate translation, and to shed light on the relationship between the different reactions in the system. This review gives an overview over the principal approaches used in the modelling efforts, and summarises some of the major findings that were made.

  6. Virtual anatomy and movement of lower extremities using virtual reality modeling language

    OpenAIRE

    Kim, D. O.; Kang, H. S.; Kim, J. H.; Min, B. G.

    2000-01-01

    In medical imaging, the use of three-dimensional image is increasing for both educational and diagnostic purposes. With the advent of techniques for browsing a three-dimensional object, it became possible to display three-dimensional images on a personal computer via the Internet. This report describes the construction of a three-dimensional virtual model of human lower extremities that was linked with the data acquired from gait analysis in order to perform threedimensional gait analysis.

  7. Bayesian Predictive Inference of a Proportion Under a Twofold Small-Area Model

    Directory of Open Access Journals (Sweden)

    Nandram Balgobin

    2016-03-01

    Full Text Available We extend the twofold small-area model of Stukel and Rao (1997; 1999 to accommodate binary data. An example is the Third International Mathematics and Science Study (TIMSS, in which pass-fail data for mathematics of students from US schools (clusters are available at the third grade by regions and communities (small areas. We compare the finite population proportions of these small areas. We present a hierarchical Bayesian model in which the firststage binary responses have independent Bernoulli distributions, and each subsequent stage is modeled using a beta distribution, which is parameterized by its mean and a correlation coefficient. This twofold small-area model has an intracluster correlation at the first stage and an intercluster correlation at the second stage. The final-stage mean and all correlations are assumed to be noninformative independent random variables. We show how to infer the finite population proportion of each area. We have applied our models to synthetic TIMSS data to show that the twofold model is preferred over a onefold small-area model that ignores the clustering within areas. We further compare these models using a simulation study, which shows that the intracluster correlation is particularly important.

  8. Physical and mathematical modeling of diesel fuel liquid and vapor movement in porous media

    International Nuclear Information System (INIS)

    Johnson, T.E.; Kreamer, D.K.

    1994-01-01

    Two-dimensional physical modeling of diesel fuel leaks was conducted in sand tanks to determine liquid and vapor migration characteristics. Mathematical modeling provided estimation of vapor concentrations at discrete times and distances from the vapor source and was compared to the physical experiment. The mathematical gaseous diffusion model was analogous to the Theis equation for ground-water flow, accounted for sorptive effects of the media, and was calibrated using measured concentrations from the sand tank. Mathematically different positions of the vapor source were tested to better relate observed liquid flow rates and media configuration to gaseous concentrations. The calculated diffusion parameters were then used to estimate theoretical, three-dimensional vapor transport from a hypothetical liquid leak of 2.0 1/hr for 30 days. The associated three-dimensional vapor plume, which would be reasonably detectable by commercially available vadose zone monitors, was estimated to have a diameter of 8 m with a vapor concentration of 50 ppm at the outside edge of the vapor plume. A careful application of the method and values can be used to give a first approximation to the number of vapor monitors required at a field site as well as the optimal locations for the monitors

  9. Modelling of strata movement with a special reference to caving mechanism in thick seam coal mining

    Energy Technology Data Exchange (ETDEWEB)

    Unver, B.; Yasitli, N.E. [Hacettepe University, Department of Mining Engineering, Beytepe 06532, Ankara (Turkey)

    2006-04-03

    Caving of top coal behind the face is the key factor affecting the efficiency of production at thick coal seams. During production of top coal by caving behind the face not only is a significant amount of coal lost in the goaf but also the coal drawn by means of caving is usually diluted considerably with surrounding rock. Therefore, it is not possible to carry out an efficient production operation unless caving of top coal behind the face is optimized. In this paper, results of 3-D modelling of the top coal caving mechanism at the M3 longwall panel of Omerler Underground Mine located at Tuncbilek (Turkey) are presented by using a finite difference code called FLAC{sup 3D}. According to modelling results, a 1.5-2.0-m-thick layer of coal just above the shield supports is well fractured. However, 3.0-3.5-m-thick layer of coal above the well-fractured part is either not fractured or fractured in the form of large blocks leading to obstruction of windows of shields during coal drawing. It is concluded that, in order to decrease dilution and increase extraction ratio and production efficiency, the top coal should be as uniformly fractured as much as possible. Hence, an efficient and continuous coal flowing behind the face can be maintained. A special pre-fracture blasting strategy just sufficient enough to form cracks in the top coal is suggested by means of comparing results from numerical modelling. (author)

  10. Modeling the spatial and temporal dynamics of foraging movements of humpback whales (Megaptera novaeangliae) in the Western Antarctic Peninsula.

    Science.gov (United States)

    Curtice, Corrie; Johnston, David W; Ducklow, Hugh; Gales, Nick; Halpin, Patrick N; Friedlaender, Ari S

    2015-01-01

    A population of humpback whales (Megaptera novaeangliae) spends the austral summer feeding on Antarctic krill (Euphausia superba) along the Western Antarctic Peninsula (WAP). These whales acquire their annual energetic needs during an episodic feeding season in high latitude waters that must sustain long-distance migration and fasting on low-latitude breeding grounds. Antarctic krill are broadly distributed along the continental shelf and nearshore waters during the spring and early summer, and move closer to land during late summer and fall, where they overwinter under the protective and nutritional cover of sea ice. We apply a novel space-time utilization distribution method to test the hypothesis that humpback whale distribution reflects that of krill: spread broadly during summer with increasing proximity to shore and associated embayments during fall. Humpback whales instrumented with satellite-linked positional telemetry tags (n = 5), show decreased home range size, amount of area used, and increased proximity to shore over the foraging season. This study applies a new method to model the movements of humpback whales in the WAP region throughout the feeding season, and presents a baseline for future observations of the seasonal changes in the movement patterns and foraging behavior of humpback whales (one of several krill-predators affected by climate-driven changes) in the WAP marine ecosystem. As the WAP continues to warm, it is prudent to understand the ecological relationships between sea-ice dependent krill and krill predators, as well as the interactions among recovering populations of krill predators that may be forced into competition for a shared food resource.

  11. Mixed Movements

    DEFF Research Database (Denmark)

    Brabrand, Helle

    2010-01-01

    levels than those related to building, and this exploration is a special challenge and competence implicit artistic development work. The project Mixed Movements generates drawing-material, not primary as representation, but as a performance-based media, making the body being-in-the-media felt and appear......Mixed Movements is a research project engaged in performance-based architectural drawing. Architectonic implementation questions relations between the human body and a body of architecture by the different ways we handle drawing materials. A drawing may explore architectonic problems at other...

  12. New model of the vertical crustal movements in the area of Poland

    OpenAIRE

    Kowalczyk, Kamil

    2006-01-01

    In 2003 the fourth levelling campaign has been finished in Poland. This campaign, together with the previous one carried out in 1974–1982, gave a very good opportunity to determine the land uplift in the area of Poland. The paper describes shortly the third and fourth campaigns, the computation of the relative land uplift, computation of land uplift referred to the mean sea level and modeling the land uplift by the least-squares collocation method. Obtained results are compared with the compu...

  13. Modelling Movement Energetics Using Global Positioning System Devices in Contact Team Sports: Limitations and Solutions.

    Science.gov (United States)

    Gray, Adrian J; Shorter, Kathleen; Cummins, Cloe; Murphy, Aron; Waldron, Mark

    2018-03-27

    Quantifying the training and competition loads of players in contact team sports can be performed in a variety of ways, including kinematic, perceptual, heart rate or biochemical monitoring methods. Whilst these approaches provide data relevant for team sports practitioners and athletes, their application to a contact team sport setting can sometimes be challenging or illogical. Furthermore, these methods can generate large fragmented datasets, do not provide a single global measure of training load and cannot adequately quantify all key elements of performance in contact team sports. A previous attempt to address these limitations via the estimation of metabolic energy demand (global energy measurement) has been criticised for its inability to fully quantify the energetic costs of team sports, particularly during collisions. This is despite the seemingly unintentional misapplication of the model's principles to settings outside of its intended use. There are other hindrances to the application of such models, which are discussed herein, such as the data-handling procedures of Global Position System manufacturers and the unrealistic expectations of end users. Nevertheless, we propose an alternative energetic approach, based on Global Positioning System-derived data, to improve the assessment of mechanical load in contact team sports. We present a framework for the estimation of mechanical work performed during locomotor and contact events with the capacity to globally quantify the work done during training and matches.

  14. “We are all Garimpeiros:” Settlement and movement in communities of the Tapajós small-scale gold mining reserve

    NARCIS (Netherlands)

    Kolen, Judith; de Smet, Eline; de Theije, M.E.M.

    2017-01-01

    Abstract Scholars have been carrying out research into the urbanization of the Brazilian Amazon since the 1960s. This article addresses the role of small-scale gold mining in urbanization, by focusing on local processes in two mining settlements in the Tapajós Mineral Province: Creporizão and

  15. Striking movements

    DEFF Research Database (Denmark)

    Dahl, Sofia

    2011-01-01

    Like all music performance, percussion playing requires high control over timing and sound properties. Specific to percussionists, however, is the need to adjust the movement to different instruments with varying physical properties and tactile feedback to the player. Furthermore, the well define...

  16. Movement disorders

    International Nuclear Information System (INIS)

    Leenders, K.L.

    1986-01-01

    This thesis describes the measurement of brain-tissue functions in patients with movement disorders using positron emission tomography (PET). This scanning technique is a method for direct in vivo quantitation of the regional tissue content of positron emitting radionuclides in brain (or other organs) in an essentially non-invasive way. Ch. 2 outlines some general features of PET and describes the scanner which has been used for the studies in this thesis. Also the tracer methodology, as applied to data investigations of movement disorders, are discussed. Ch. 3 contains the results of the PET investigations which were performed in the study of movement disorders. The results are presented in the form of 12 papers. The main goals of these studies were the understanding of the pathophysiology of Parkinson's disease, Huntington's chorea, Steele-Richardson-Olzewski syndrome and special case reports. Ch. 4 summarizes the results of these publications and Ch. 5 concludes the main part of this thesis with a general discussion of movement disorders in relation to PET investigations. 697 refs.; 60 figs.; 31 tabs

  17. Psychodynamic Movement

    DEFF Research Database (Denmark)

    Pedersen, Inge Nygaard

    2002-01-01

    This chapter/article describes the historical development of the disciplin Psychodynamic Movement. The importance of this disciplin for self-experience and for training in developing a therapist identy for the music therapy students are emphasized. Prototypeexercises developed and simplified...

  18. A novel Eulerian approach for modelling cyanobacteria movement: Thin layer formation and recurrent risk to drinking water intakes.

    Science.gov (United States)

    Ndong, Mouhamed; Bird, David; Nguyen Quang, Tri; Kahawita, René; Hamilton, David; de Boutray, Marie Laure; Prévost, Michèle; Dorner, Sarah

    2017-12-15

    Toxic cyanobacteria (CB) blooms are being reported in an increasing number of water bodies worldwide. As drinking water (DW) treatment can be disrupted by CB, in addition to long term management plans, short term operational decision-making tools are needed that enable an understanding of the temporal variability of CB movement in relation to drinking water intakes. In this paper, we propose a novel conservative model based on a Eulerian framework and compare results with data from CB blooms in Missisquoi Bay (Québec, Canada). The hydrodynamic model considered the effects of wind and light intensity, demonstrated that current understanding of cell buoyancy in relation to light intensity in full-scale systems is incomplete and some factors are yet to be fully characterized. Factors affecting CB buoyancy play a major role in the formation of a thin surface layer that could be of ecological importance with regards to cell concentrations and toxin production. Depending on velocities, wind contributes either to the accumulation or to the dispersion of CB. Lake recirculation effects have a tendency to create zones of low CB concentrations in a water body. Monitoring efforts and future research should focus on short-term variations of CB throughout the water column and the characterization of factors other than light intensity that affect cell buoyancy. These factors are critical for understanding the risk of breakthrough into treatment plants as well as the formation of surface scums and subsequent toxin production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. A small community model for the transmission of infectious diseases: comparison of school closure as an intervention in individual-based models of an influenza pandemic.

    Directory of Open Access Journals (Sweden)

    George J Milne

    Full Text Available BACKGROUND: In the absence of other evidence, modelling has been used extensively to help policy makers plan for a potential future influenza pandemic. METHOD: We have constructed an individual based model of a small community in the developed world with detail down to exact household structure obtained from census collection datasets and precise simulation of household demographics, movement within the community and individual contact patterns. We modelled the spread of pandemic influenza in this community and the effect on daily and final attack rates of four social distancing measures: school closure, increased case isolation, workplace non-attendance and community contact reduction. We compared the modelled results of final attack rates in the absence of any interventions and the effect of school closure as a single intervention with other published individual based models of pandemic influenza in the developed world. RESULTS: We showed that published individual based models estimate similar final attack rates over a range of values for R(0 in a pandemic where no interventions have been implemented; that multiple social distancing measures applied early and continuously can be very effective in interrupting transmission of the pandemic virus for R(0 values up to 2.5; and that different conclusions reached on the simulated benefit of school closure in published models appear to result from differences in assumptions about the timing and duration of school closure and flow-on effects on other social contacts resulting from school closure. CONCLUSION: Models of the spread and control of pandemic influenza have the potential to assist policy makers with decisions about which control strategies to adopt. However, attention needs to be given by policy makers to the assumptions underpinning both the models and the control strategies examined.

  20. A New Perspective on Design Education: A "Creative Production-Manufacturing Model" in "The Maker Movement" Context

    Science.gov (United States)

    Zhong, Xiang-Ming; Fan, Kuo-Kuang

    2016-01-01

    When "The Maker Movement" started, it made a great impact and influence on many aspects of society. "The Maker Movement" has transformed industries as well as people's way of life and thinking. For this reason, many people decided to create something by turning their ideas to tangible products. Media has become a bridge that…

  1. Spontaneous body movements in spatial cognition

    Directory of Open Access Journals (Sweden)

    Sergiu eTcaci Popescu

    2012-05-01

    Full Text Available People often perform spontaneous body movements during spatial tasks such as giving complex directions or orienting themselves on maps. How are these spontaneous gestures related to spatial problem-solving? We measured spontaneous movements during a perspective-taking task inspired by map reading. Analyzing the motion data to isolate rotation and translation components of motion in specific geometric relation to the task, we found out that most participants executed spontaneous miniature rotations of the head that were significantly related to the main task parameter. These head rotations were as if participants were trying to align themselves with the orientation on the map either in the image plane or on the ground plane, but with tiny amplitudes, typically below 1% of the actual movements. Our results are consistent with a model of sensorimotor prediction driving spatial reasoning. The efference copy of planned movements triggers this prediction mechanism. The movements themselves may then be mostly inhibited; the small spontaneous gestures that we measure are the visible traces of these planned but inhibited actions.

  2. Active buildings: modelling physical activity and movement in office buildings. An observational study protocol.

    Science.gov (United States)

    Smith, Lee; Ucci, Marcella; Marmot, Alexi; Spinney, Richard; Laskowski, Marek; Sawyer, Alexia; Konstantatou, Marina; Hamer, Mark; Ambler, Gareth; Wardle, Jane; Fisher, Abigail

    2013-11-12

    Health benefits of regular participation in physical activity are well documented but population levels are low. Office layout, and in particular the number and location of office building destinations (eg, print and meeting rooms), may influence both walking time and characteristics of sitting time. No research to date has focused on the role that the layout of the indoor office environment plays in facilitating or inhibiting step counts and characteristics of sitting time. The primary aim of this study was to investigate associations between office layout and physical activity, as well as sitting time using objective measures. Active buildings is a unique collaboration between public health, built environment and computer science researchers. The study involves objective monitoring complemented by a larger questionnaire arm. UK office buildings will be selected based on a variety of features, including office floor area and number of occupants. Questionnaires will include items on standard demographics, well-being, physical activity behaviour and putative socioecological correlates of workplace physical activity. Based on survey responses, approximately 30 participants will be recruited from each building into the objective monitoring arm. Participants will wear accelerometers (to monitor physical activity and sitting inside and outside the office) and a novel tracking device will be placed in the office (to record participant location) for five consecutive days. Data will be analysed using regression analyses, as well as novel agent-based modelling techniques. The results of this study will be disseminated through peer-reviewed publications and scientific presentations. Ethical approval was obtained through the University College London Research Ethics Committee (Reference number 4400/001).

  3. Uncertainty Estimation in SiGe HBT Small-Signal Modeling

    DEFF Research Database (Denmark)

    Masood, Syed M.; Johansen, Tom Keinicke; Vidkjær, Jens

    2005-01-01

    An uncertainty estimation and sensitivity analysis is performed on multi-step de-embedding for SiGe HBT small-signal modeling. The uncertainty estimation in combination with uncertainty model for deviation in measured S-parameters, quantifies the possible error value in de-embedded two-port param...

  4. A simple model for dynamic small-angle X-ray diffraction in colloidal crystals

    NARCIS (Netherlands)

    de Beer, A.G.F.; Petukhov, A.V.

    2007-01-01

    A simple model is presented that allows calculation of the small-angle X-ray diffraction patterns of perfect colloidal crystals. The model is based on the Wentzel–Kramers–Brillouin approximation and permits a straightforward evaluation of multibeam interactions. Results are illustrated by several

  5. Human Enteroids as a Model of Upper Small Intestinal Ion Transport Physiology and Pathophysiology

    NARCIS (Netherlands)

    J. Foulke-Abel (Jennifer); J. In (Julie); Yin, J. (Jianyi); N.C. Zachos (Nicholas C.); O. Kovbasnjuk (Olga); M.K. Estes (Mary K.); H.R. de Jonge (Hugo); M. Donowitz (Mark)

    2016-01-01

    textabstractBackground & Aims Human intestinal crypt-derived enteroids are a model of intestinal ion transport that require validation by comparison with cell culture and animal models. We used human small intestinal enteroids to study neutral Na+ absorption and stimulated fluid and anion secretion

  6. SUSTAINABLE AGRICULTURE PRODUCTION MODEL FOR SMALL FARMER IN RAINFED ARID LAND

    OpenAIRE

    Sharma, Arun K.

    2015-01-01

    A production system model has been developed at model organic farm ,CAZRI,Jodhpur,India with integration of organic system and rainwater harvesting that can be proved viable for providing livelihood security and income insurance to the small farmers in rainfed arid land.

  7. Simulated small-angle scattering patterns for a plastically deformed model composite material

    NARCIS (Netherlands)

    Shenoy, V.B.; Cleveringa, H.H.M.; Phillips, R.; Giessen, E. van der; Needleman, A.

    2000-01-01

    The small-angle scattering patterns predicted by discrete dislocation plasticity versus local and non-local continuum plasticity theory are compared in a model problem. The problem considered is a two-dimensional model composite with elastic reinforcements in a crystalline matrix subject to

  8. Movement pattern and physiological response in recreational small-sided football - effect of number of players with a fixed pitch size

    DEFF Research Database (Denmark)

    Randers, Morten B; Ørntoft, Christina; Hagman, Marie

    2018-01-01

    Recreational soccer is an effective health-promoting activity, but it is unclear how different game formats influence internal and external load. Thus, to be able to advise how to maximise the outcome of recreational football, we examined movement pattern and physiological response in 11 untrained.......05) total distance and high-speed distance was covered during 3v3 than 5v5 (14 and 30%) and 7v7 (15 and 75%). Mean HR was higher in 3v3 (85.7 ± 5.7%HRmax) and 5v5 (84.2 ± 5.1%HRmax) than in 7v7 (80.7 ± 4.6%HRmax, P 90%HR was higher in 3v3 (43 ± 18%, P ... ± 21%) and 7v7 (18 ± 14%). Blood lactate was higher in 3v3 (7.4 ± 2.7 mmol·l-1) than in 7v7 (4.5 ± 2.2 mmol·l-1, P external...

  9. Adapted strategic plannig model applied to small business: a case study in the fitness area

    Directory of Open Access Journals (Sweden)

    Eduarda Tirelli Hennig

    2012-06-01

    Full Text Available The strategic planning is an important management tool in the corporate scenario and shall not be restricted to big Companies. However, this kind of planning process in small business may need special adaptations due to their own characteristics. This paper aims to identify and adapt the existent models of strategic planning to the scenario of a small business in the fitness area. Initially, it is accomplished a comparative study among models of different authors to identify theirs phases and activities. Then, it is defined which of these phases and activities should be present in a model that will be utilized in a small business. That model was applied to a Pilates studio; it involves the establishment of an organizational identity, an environmental analysis as well as the definition of strategic goals, strategies and actions to reach them. Finally, benefits to the organization could be identified, as well as hurdles in the implementation of the tool.

  10. Imaging system models for small-bore DOI-PET scanners

    International Nuclear Information System (INIS)

    Takahashi, Hisashi; Kobayashi, Tetsuya; Yamaya, Taiga; Murayama, Hideo; Kitamura, Keishi; Hasegawa, Tomoyuki; Suga, Mikio

    2006-01-01

    Depth-of-interaction (DOI) information, which improves resolution uniformity in the field of view (FOV), is expected to lead to high-sensitivity PET scanners with small-bore detector rings. We are developing small-bore PET scanners with DOI detectors arranged in hexagonal or overlapped tetragonal patterns for small animal imaging or mammography. It is necessary to optimize the imaging system model because these scanners exhibit irregular detector sampling. In this work, we compared two imaging system models: (a) a parallel sub-LOR model in which the detector response functions (DRFs) are assumed to be uniform along the line of responses (LORs) and (b) a sub-crystal model in which each crystal is divided into a set of smaller volumes. These two models were applied to the overlapped tetragonal scanner (FOV 38.1 mm in diameter) and the hexagonal scanner (FOV 85.2 mm in diameter) simulated by GATE. We showed that the resolution non-uniformity of system model (b) was improved by 40% compared with that of system model (a) in the overlapped tetragonal scanner and that the resolution non-uniformity of system model (a) was improved by 18% compared with that of system model (b) in the hexagonal scanner. These results indicate that system model (b) should be applied to the overlapped tetragonal scanner and system model (a) should be applied to the hexagonal scanner. (author)

  11. Modelling small-angle scattering data from complex protein-lipid systems

    DEFF Research Database (Denmark)

    Kynde, Søren Andreas Røssell

    the techniques very well suited for the study of the nanodisc system. Chapter 3 explains two different modelling approaches that can be used in the analysis of small-angle scattering data from lipid-protein complexes. These are the continuous approach where the system of interest is modelled as a few regular...... are particularly interesting to study because they are common targets for pharmaceutical drugs. At the same time they are unfortunately unstable in solution which make them challenging to study. Phospholipid nanodiscs are small patches of lipid membrane stabilised by a belt of amphipathic helices. They can act...... as carriers of membrane proteins. Together they form monodisperse soluble aggregates of about 10 nm in size. Chapter 2 introduces the method of small-angle scattering. Small-angle X-ray and neutron scattering are well suited for studying particles in solution on length scales from 1 to 100 nm. This makes...

  12. Do Readers Obtain Preview Benefit from Word n + 2? A Test of Serial Attention Shift versus Distributed Lexical Processing Models of Eye Movement Control in Reading

    Science.gov (United States)

    Rayner, Keith; Juhasz, Barbara J.; Brown, Sarah J.

    2007-01-01

    Two experiments tested predictions derived from serial lexical processing and parallel distributed models of eye movement control in reading. The boundary paradigm (K. Rayner, 1975) was used, and the boundary location was set either at the end of word n - 1 (the word just to the left of the target word) or at the end of word n - 2. Serial lexical…

  13. Self-Regulated Learning from Illustrated Text: Eye Movement Modelling to Support Use and Regulation of Cognitive Processes during Learning from Multimedia

    Science.gov (United States)

    Scheiter, Katharina; Schubert, Carina; Schüler, Anne

    2018-01-01

    Background: When learning with text and pictures, learners often fail to adequately process the materials, which can be explained as a failure to self-regulate one's learning by choosing adequate cognitive learning processes. Eye movement modelling examples (EMME) showing how to process multimedia instruction have improved elementary school…

  14. Fast fitting of non-Gaussian state-space models to animal movement data via Template Model Builder

    DEFF Research Database (Denmark)

    Albertsen, Christoffer Moesgaard; Whoriskey, Kim; Yurkowski, David

    2015-01-01

    recommend using the Laplace approximation combined with automatic differentiation (as implemented in the novel R package Template Model Builder; TMB) for the fast fitting of continuous-time multivariate non-Gaussian SSMs. Through Argos satellite tracking data, we demonstrate that the use of continuous...... are able to estimate additional parameters compared to previous methods, all without requiring a substantial increase in computational time. The model implementation is made available through the R package argosTrack....

  15. MILITARY RECRUITMENT MODEL FOR ARMED FORCES OF SMALL STATES AND MIDDLE POWERS

    OpenAIRE

    Jaroslav Usiak; Erik Gorner

    2018-01-01

    States have many functions. The core one should be keeping its sovereignty and territorial integrity. Diplomacy and international law cannot guarantee their security. An armed force is an inherent part of each state that wants to be truly independent. Small states and middle powers have more difficulties when recruiting manpower for the military service compared to the great powers. The aim of this article is to find out what kind of recruitment model is the most suitable for small states and...

  16. Modelling small-angle scattering data from complex protein-lipid systems

    DEFF Research Database (Denmark)

    Kynde, Søren Andreas Røssell

    as carriers of membrane proteins. Together they form monodisperse soluble aggregates of about 10 nm in size. Chapter 2 introduces the method of small-angle scattering. Small-angle X-ray and neutron scattering are well suited for studying particles in solution on length scales from 1 to 100 nm. This makes...... describes a protein system that has successfully been measured with small-angle scattering methods and subsequently analysed using the hybrid approach. Paper I governs the transmembrane protein bacteriorhodopsin embedded into a phospholipid nanodisc. The modelling is based on a crystal structure...

  17. Phasor model of full scale converter wind turbine for small-signal stability analysis

    OpenAIRE

    Gihga, Radu; Wu, Qiuwei; Nielsen, Arne Hejde

    2017-01-01

    The small-signal stability analysis of power system electromechanical oscillations is a well-established field in control and stability assessment of power systems. The impact of large wind farms on small-signal stability of power systems has been a topic of high interest in recent years. This study presents a phasor model of full scale converter wind turbines (WTs) implemented in MATLAB/SIMULINK for small-signal stability studies. The phasor method is typically used for dynamic studies of po...

  18. Small-signal model parameter extraction for AlGaN/GaN HEMT

    Science.gov (United States)

    Le, Yu; Yingkui, Zheng; Sheng, Zhang; Lei, Pang; Ke, Wei; Xiaohua, Ma

    2016-03-01

    A new 22-element small signal equivalent circuit model for the AlGaN/GaN high electron mobility transistor (HEMT) is presented. Compared with the traditional equivalent circuit model, the gate forward and breakdown conductions (G gsf and G gdf) are introduced into the new model to characterize the gate leakage current. Additionally, for the new gate-connected field plate and the source-connected field plate of the device, an improved method for extracting the parasitic capacitances is proposed, which can be applied to the small-signal extraction for an asymmetric device. To verify the model, S-parameters are obtained from the modeling and measurements. The good agreement between the measured and the simulated results indicate that this model is accurate, stable and comparatively clear in physical significance.

  19. Small-signal model parameter extraction for AlGaN/GaN HEMT

    International Nuclear Information System (INIS)

    Yu Le; Zhang Sheng; Ma Xiaohua; Zheng Yingkui; Pang Lei; Wei Ke

    2016-01-01

    A new 22-element small signal equivalent circuit model for the AlGaN/GaN high electron mobility transistor (HEMT) is presented. Compared with the traditional equivalent circuit model, the gate forward and breakdown conductions (G gsf and G gdf ) are introduced into the new model to characterize the gate leakage current. Additionally, for the new gate-connected field plate and the source-connected field plate of the device, an improved method for extracting the parasitic capacitances is proposed, which can be applied to the small-signal extraction for an asymmetric device. To verify the model, S-parameters are obtained from the modeling and measurements. The good agreement between the measured and the simulated results indicate that this model is accurate, stable and comparatively clear in physical significance. (paper)

  20. Antinuclear movement

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Hee; Im, Jaeg Yeong

    1988-08-15

    This book is for antinuclear movement. So, this book introduces many articles on nuclear issues of Asia and the pacific area. The titles of articles are the crusades of Reagan by Werner Plaha, contending between super powers in Europe by Alva Reimer Myrdal, claims of resistance by Daniel Ellsberg, nuclear and the Korean Peninsula by Go, Seung Woo, Liberation but of belief of nuclear weapon by Lee, Young Hee and nuclear weapon in Korea by peter Haze.

  1. Three-dimensional Acoustic Localisation via Directed Movements of a Two-dimensional Model of the Lizard Peripheral Auditory System

    DEFF Research Database (Denmark)

    Shaikh, Danish; Kjær Schmidt, Michael

    2017-01-01

    Three-dimensional acoustic localisation is relevant in personal and social robot platforms. Conventional approaches extract interaural time difference cues via impractically large stationary two-dimensional multi-microphone grids with at least four microphones or spectral cues via head-related tr......Three-dimensional acoustic localisation is relevant in personal and social robot platforms. Conventional approaches extract interaural time difference cues via impractically large stationary two-dimensional multi-microphone grids with at least four microphones or spectral cues via head......-related transfer functions of stationary KEMAR dummy heads equipped with two microphones. We present a preliminary approach using two sound sensors, whose directed movements resolve the location of a stationary acoustic target in three dimensions. A model of the peripheral auditory system of lizards provides sound...... direction information in a single plane which by itself is insufficient to localise the acoustic target in three dimensions. Two spatial orientations of this plane by rotating the sound sensors by -45 deg. and +45 deg. along the sagittal axis generate a pair of measurements, each encoding the location...

  2. Establishment of a mathematical model for the influence of respiratory movement upon the position of an intrahepatic space-occupying lesion

    International Nuclear Information System (INIS)

    Yu Yonghua; Luo Limin; Li Baosheng; Yu Jinming; Liang Chaoqian; Zhao Yuehuan

    2002-01-01

    Objective: To investigate the extent of liver lesion shifting with respiration in an attempt to establish a relevant mathematical model. Methods: We measured breathing movements with B ultrasonography in 84 primary or metastatic liver tumors and defined the relation between the lesion shifting extent with age, sex, height, weight, lesion location and size analyzed with the SPSS statistic software. Results: The Z, X and Y breathing-axis motions were 1.029±0.321 cm (range: 0.6-1.9 cm), 0.301 ± 0.131 cm (range: 0.0-0.6 cm) and 0.387±0.130 cm (range: 0.2-0.7 cm), respectively. The movement-related factor analysis revealed that age, weight and (right lobe) lesion location presented a negative relationship but height, sex and lesion size presented a positive relationship for Z, Y and X breathing-axis motions. Their mathematical regression models were established as Z = -2.660 + 2.952 H-1.539 x 10 -2 W-3.928 x 10 -3 A; Y = -0. 926 + 0. 987 H-4.992 x 10 -3 W, and X = 0.507 + 7.629 x 10 -2 S-3.686 x 10 -3 W [H : height (m), W : weight (kg) A : age (year), S : sex(M:1, F: 0)]. The liver breathing movement was verified with the model in another 11 patients and the conformation rate was up to 91%. Conclusions: The impact of breathing movement on the location of intrahepatic lesion is mainly focused on the Z-axis motion. The practical accuracy in anticipating breathing movement with the mathematical model is so justified that the use of this model be recommended in stereotactic radiotherapy

  3. MOVEMENT OF INTRA-INDUSTRY TRADE INDEX IN TERMS OF EXCHANGE RATE CHANGE: THEORETICAL ANALYSIS BASED ON A TWO-STAGE PRODUCTION MODEL

    Directory of Open Access Journals (Sweden)

    Nobuhiro Takahashi

    2017-09-01

    Full Text Available This paper analyzes the movement of intra-industry trade index when the exchange rate or the world price changes. In our two-stage production model, firms construct factories in a foreign country by foreign direct investment (FDI. The firms export components from the home country to the foreign factories, and import final products from the foreign factories. The foreign factories also sell the final products in the world market. Under this knockdown system, we research the movement of the intra-industry trade index of the home country. This paper shows that appreciation of the exchange rate does not always raise the intra-industry trade index. We also show that changes in the world price have the similar effect on the movement of the intra-industry trade index.

  4. Bilateral alteration in stepping pattern after unilateral motor cortex injury: a new test strategy for analysis of skilled limb movements in neurological mouse models.

    Science.gov (United States)

    Farr, Tracy D; Liu, Lily; Colwell, Keri L; Whishaw, Ian Q; Metz, Gerlinde A

    2006-05-15

    Mice are becoming increasingly popular to model neurological disease and motor system dysfunction. For evaluation of discrete, chronic motor impairments, skilled limb movements represent a valuable extension of standard mouse test batteries. This study introduces an efficient and sensitive test strategy for comprehensive assessment of skilled fore- and hind-limb stepping in mice. Adult C57BL/6 mice were trained and video-recorded in two walking tasks, the widely used rotorod test and a new ladder rung task. The animals then received a unilateral ischemic lesion in the motor cortex forelimb and hind limb area and were video-recorded on days 12 and 26 post-lesion. Forelimb and hind limb stepping movements were rated using a combination of endpoint measures and qualitative assessment. The results showed that while animals maintained a weight-supported gait, posture and stepping movements were abnormal at both post-operative intervals. The rotorod analysis revealed stepping deficits in both forelimbs that led to adoption of compensatory movement strategies. The ladder rung task revealed stepping errors in ipsi- and contralateral fore- and hind-limbs. The findings demonstrate that this test strategy provides comprehensive assessment of motor impairments in mice and that qualitative movement analysis is a valuable tool for elaborating subtle motor disturbances.

  5. A model for design of tailored working environment intervention programmes for small enterprises.

    Science.gov (United States)

    Hasle, Peter; Kvorning, Laura V; Rasmussen, Charlotte Dn; Smith, Louise H; Flyvholm, Mari-Ann

    2012-09-01

    Small enterprises have higher exposure to occupational hazards compared to larger enterprises and further, they have fewer resources to control the risks. In order to improve the working environment, development of efficient measures is therefore a major challenge for regulators and other stakeholders. The aim of this paper is to develop a systematic model for the design of tailored intervention programmes meeting the needs of small enterprises. An important challenge for the design process is the transfer of knowledge from one context to another. The concept of realist analysis can provide insight into mechanisms by which intervention knowledge can be transferred from one context to another. We use this theoretical approach to develop a design model. THE MODEL CONSIST OF FIVE STEPS: 1) Defining occupational health and safety challenges of the target group, 2) selecting methods to improve the working environment, 3) developing theories about mechanisms which motivate the target group, 4) analysing the specific context of the target group for small enterprise programmes including owner-management role, social relations, and the perception of the working environment, and 5) designing the intervention based on the preceding steps. We demonstrate how the design model can be applied in practice by the development of an intervention programme for small enterprises in the construction industry. The model provides a useful tool for a systematic design process. The model makes it transparent for both researchers and practitioners as to how existing knowledge can be used in the design of new intervention programmes.

  6. Small signal modeling of AlGaN/GaN HEMTs with consideration of CPW capacitances

    International Nuclear Information System (INIS)

    Du Jiangfeng; Wang Kang; Yin Chenggong; Liu Yang; Yu Qi; Xu Peng; Feng Zhihong; Dun Shaobo

    2015-01-01

    Given the coplanar waveguide (CPW) effect on AlGaN/GaN high electron mobility transistors at a high frequency, the traditional equivalent circuit model cannot accurately describe the electrical characteristics of the device. The admittance of CPW capacitances is large when the frequency is higher than 40 GHz; its impact on the device cannot be ignored. In this study, a small-signal equivalent circuit model considering CPW capacitance is provided. To verify the model, S-parameters are obtained from the modeling and measurements. A good agreement is observed between the simulation and measurement results, indicating the reliability of the model. (paper)

  7. System Dynamics Modeling of interactive cost factors for small modular reactors

    International Nuclear Information System (INIS)

    Ahn, Nam Sung; Lee, Keun Dae; Yoon, Suk Ho

    2011-01-01

    As a part of the Study on Economic Efficiency and Marketability of small modular reactors project, we at Nemo partners NEC consulting corporation were studying the various cost factors on small modular reactors (SMRs). To have a better knowledge of the interaction between the cost factors, System Dynamics Modeling has been developed. This model will contribute to our understanding of the interaction on the major factors effecting on the unit cost of SMRs to the SMRs' market share in the market economics as competition

  8. Progress in model development for eddy current response in the presence of small conductivity changes

    Science.gov (United States)

    Cherry, Matt; Sathish, Shamachary; Mooers, Ryan; Pilchak, Adam

    2016-02-01

    In this paper, an approximation technique for predicting the response of an eddy current coil in the presence of small changes in conductivity is discussed. The small changes in conductivity that are considered in this work are changes in the orientation of single crystals in polycrystalline, anisotropic materials. Data from electron backscatter imaging techniques is presented and used for the analysis. The models were run for the microstructure data and an approximation to the eddy current response is shown. This image is compared with images from actual eddy current probes and the approximations are shown to be relatively accurate compared with a previously presented model.

  9. Financial analysis and forecasting of the results of small businesses performance based on regression model

    Directory of Open Access Journals (Sweden)

    Svetlana O. Musienko

    2017-03-01

    Full Text Available Objective to develop the economicmathematical model of the dependence of revenue on other balance sheet items taking into account the sectoral affiliation of the companies. Methods using comparative analysis the article studies the existing approaches to the construction of the company management models. Applying the regression analysis and the least squares method which is widely used for financial management of enterprises in Russia and abroad the author builds a model of the dependence of revenue on other balance sheet items taking into account the sectoral affiliation of the companies which can be used in the financial analysis and prediction of small enterprisesrsquo performance. Results the article states the need to identify factors affecting the financial management efficiency. The author analyzed scientific research and revealed the lack of comprehensive studies on the methodology for assessing the small enterprisesrsquo management while the methods used for large companies are not always suitable for the task. The systematized approaches of various authors to the formation of regression models describe the influence of certain factors on the company activity. It is revealed that the resulting indicators in the studies were revenue profit or the company relative profitability. The main drawback of most models is the mathematical not economic approach to the definition of the dependent and independent variables. Basing on the analysis it was determined that the most correct is the model of dependence between revenues and total assets of the company using the decimal logarithm. The model was built using data on the activities of the 507 small businesses operating in three spheres of economic activity. Using the presented model it was proved that there is direct dependence between the sales proceeds and the main items of the asset balance as well as differences in the degree of this effect depending on the economic activity of small

  10. High resolution climate scenarios for snowmelt modelling in small alpine catchments

    Science.gov (United States)

    Schirmer, M.; Peleg, N.; Burlando, P.; Jonas, T.

    2017-12-01

    Snow in the Alps is affected by climate change with regard to duration, timing and amount. This has implications with respect to important societal issues as drinking water supply or hydropower generation. In Switzerland, the latter received a lot of attention following the political decision to phase out of nuclear electricity production. An increasing number of authorization requests for small hydropower plants located in small alpine catchments was observed in the recent years. This situation generates ecological conflicts, while the expected climate change poses a threat to water availability thus putting at risk investments in such hydropower plants. Reliable high-resolution climate scenarios are thus required, which account for small-scale processes to achieve realistic predictions of snowmelt runoff and its variability in small alpine catchments. We therefore used a novel model chain by coupling a stochastic 2-dimensional weather generator (AWE-GEN-2d) with a state-of-the-art energy balance snow cover model (FSM). AWE-GEN-2d was applied to generate ensembles of climate variables at very fine temporal and spatial resolution, thus providing all climatic input variables required for the energy balance modelling. The land-surface model FSM was used to describe spatially variable snow cover accumulation and melt processes. The FSM was refined to allow applications at very high spatial resolution by specifically accounting for small-scale processes, such as a subgrid-parametrization of snow covered area or an improved representation of forest-snow processes. For the present study, the model chain was tested for current climate conditions using extensive observational dataset of different spatial and temporal coverage. Small-scale spatial processes such as elevation gradients or aspect differences in the snow distribution were evaluated using airborne LiDAR data. 40-year of monitoring data for snow water equivalent, snowmelt and snow-covered area for entire

  11. Vibrating makes for better seeing: from the fly's micro eye movements to hyperacute visual sensors

    Directory of Open Access Journals (Sweden)

    Stéphane eViollet

    2014-04-01

    Full Text Available Active vision means that visual perception not only depends closely on the subject's own movements, but that these movements actually contribute to the visual perceptual processes. Vertebrates' and invertebrates' eye movements are probably part of an active visual process, but their exact role still remains to be determined. In this paper, studies on the retinal micro-movements occurring in the compound eye of the fly are reviewed. Several authors have located and identified the muscles involved in these small retinal movements. Others have established that these retinal micro-movements occur in walking and flying flies, but their exact functional role still remains to be determined. Many robotic studies have been performed in which animals' (flies' and spiders' miniature eye movements have been modelled, simulated and even implemented mechanically. Several robotic platforms have been endowed with artificial visual sensors performing periodic micro-scanning movements. Artificial eyes performing these active retinal micro-movements have some extremely interesting properties, such as hyperacuity and the ability to detect very slow movements (motion hyperacuity. The fundamental role of miniature eye movements still remains to be described in detail, but several studies on natural and artificial eyes have advanced considerably toward this goal.

  12. Resistance to Ditylenchus destructor Infection in Sweet Potato by the Expression of Small Interfering RNAs Targeting unc-15, a Movement-Related Gene.

    Science.gov (United States)

    Fan, Weijuan; Wei, Zhaorong; Zhang, Min; Ma, Peiyong; Liu, Guiling; Zheng, Jianli; Guo, Xiaoding; Zhang, Peng

    2015-11-01

    Stem nematode (Ditylenchus destructor) is one of most serious diseases that limit the productivity and quality of sweet potato (Ipomoea batatas), a root crop with worldwide importance for food security and nutrition improvement. Hence, there is a global demand for developing sweet potato varieties that are resistant to the disease. In this study, we have investigated the interference of stem nematode infectivity by the expression of small interfering RNAs (siRNAs) in transgenic sweet potato that are homologous to the unc-15 gene, which affects the muscle protein paramyosin of the pathogen. The production of double-stranded RNAs and siRNAs in transgenic lines with a single transgene integration event was verified by Northern blot analysis. The expression of unc-15 was reduced dramatically in stem nematodes collected from the inoculated storage roots of transgenic plants, and the infection areas of their storage roots were dramatically smaller than that of wild-type (WT). Compared with the WT, the transgenic plants showed increased yield in the stem nematode-infested field. Our results demonstrate that the expression of siRNAs targeting the unc-15 gene of D. destructor is an effective approach in improving stem nematode resistance in sweet potato, in adjunct with the global integrated pest management programs.

  13. A customized light sheet microscope to measure spatio-temporal protein dynamics in small model organisms.

    Science.gov (United States)

    Rieckher, Matthias; Kyparissidis-Kokkinidis, Ilias; Zacharopoulos, Athanasios; Kourmoulakis, Georgios; Tavernarakis, Nektarios; Ripoll, Jorge; Zacharakis, Giannis

    2015-01-01

    We describe a customizable and cost-effective light sheet microscopy (LSM) platform for rapid three-dimensional imaging of protein dynamics in small model organisms. The system is designed for high acquisition speeds and enables extended time-lapse in vivo experiments when using fluorescently labeled specimens. We demonstrate the capability of the setup to monitor gene expression and protein localization during ageing and upon starvation stress in longitudinal studies in individual or small groups of adult Caenorhabditis elegans nematodes. The system is equipped to readily perform fluorescence recovery after photobleaching (FRAP), which allows monitoring protein recovery and distribution under low photobleaching conditions. Our imaging platform is designed to easily switch between light sheet microscopy and optical projection tomography (OPT) modalities. The setup permits monitoring of spatio-temporal expression and localization of ageing biomarkers of subcellular size and can be conveniently adapted to image a wide range of small model organisms and tissue samples.

  14. Implications of a conceptual model for the allocation of energy resources by small mammals

    International Nuclear Information System (INIS)

    Wunder, B.A.

    1978-01-01

    This paper presents a conceptual model describing the manner in which small mammals utilize energy and the ways in which the physical environment influences allocation of energy resources. It is suggested that for homeothermic mammals, thermoregulation is a first priority for energy utilization and feeding a second priority. Once these needs are met additional energy gathered may be allocated to production or other behaviors. Deductions from the model, coupled with conclusions from field studies of weather effects on small mammal reproduction and the effects of supplemental feeding experiments on reproduction, suggest that many difficulties in interpreting such studies may be due to inattention to the interactive effects of food and weather on reproduction. The paper then describes the manner in which three sorts of environments (subarctic-boreal, north temperate grassland, and deserts) vary seasonally in their productivity and level of cold stress for small mammals

  15. Prognostic and symptomatic aspects of rapid eye movement sleep in a mouse model of posttraumatic stress disorder

    Directory of Open Access Journals (Sweden)

    Stephanie A. Polta

    2013-05-01

    Full Text Available Not every individual develops Posttraumatic Stress Disorder (PTSD after the exposure to a potentially traumatic event. Therefore, the identification of pre-existing risk factors and early diagnostic biomarkers is of high medical relevance. However, no objective biomarker has yet progressed into clinical practice. Sleep disturbances represent commonly reported complaints in PTSD patients. In particular, changes in rapid eye movement sleep (REMS properties are frequently observed in PTSD patients. Here, we examined in a mouse model of PTSD whether (1 mice developed REMS alterations after trauma and (2 whether REMS architecture before and/or shortly after trauma predicted the development of PTSD-like symptoms. We monitored sleep-wake behavior via combined EEG/EMG recordings immediately before (24 h pre, immediately after (0-48 h post and two months after exposure to an electric foot shock in male C57BL/6N mice (n=15. PTSD-like symptoms, including hyperarousal, contextual and generalized fear, were assessed one month post-trauma.Shocked mice showed early-onset and sustained elevation of REMS compared to non-shocked controls. In addition, REMS architecture before trauma was correlated with the intensity of acoustic startle responses, but not contextual fear, one month after trauma.Our data suggest REMS as prognostic (pre-trauma and symptomatic (post-trauma marker of PTSD-like symptoms in mice. Translated to the situation in humans, REMS may constitute a viable, objective and non-invasive biomarker in PTSD and other trauma-related psychiatric disorders, which could guide pharmacological interventions in humans at high risk.

  16. Market dimensionality and the proliferation of small-scale firms : An agent-based modeling simulation

    NARCIS (Netherlands)

    Garcia Diaz, Cesar; van Witteloostuijn, A.

    We build an agent-based computational model to study how the changing number of active product variants in a two-dimensional product space affects the performance of different firm types (i.e. large-scale and small-scale enterprises). We use an alternative approach to measure product space

  17. Validation of a mesoscale hydrological model in a small-scale forested catchment

    Czech Academy of Sciences Publication Activity Database

    Šípek, Václav; Tesař, Miroslav

    2016-01-01

    Roč. 47, č. 1 (2016), s. 27-41 ISSN 1998-9563 R&D Projects: GA TA ČR TA02021451 Institutional support: RVO:67985874 Keywords : hydrological modelling * small catchment * soil moisture * subsurface lateral flow * SWIM Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.754, year: 2016

  18. Development and Analysis of a Swept Blade Aeroelastic Model for a Small Wind Turbine (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Preus, R.; Damiani, R.; Lee, S.; Larwood, S.

    2014-06-01

    As part of the U.S. Department-of-Energy-funded Competitiveness Improvement Project, the National Renewable Energy Laboratory (NREL) developed new capabilities for aeroelastic modeling of precurved and preswept blades for small wind turbines. This presentation covers the quest for optimized rotors, computer-aided engineering tools, a case study, and summary of the results.

  19. A Life-Cycle Overlapping-Generations Model of the Small Open Economy

    NARCIS (Netherlands)

    Heijdra, Ben J.; Romp, Ward E.

    2005-01-01

    In this paper we construct an overlapping generations model for the small open economy incorporating a realistic description of the mortality process. With agedependent mortality, the typical life-cycle pattern of consumption and saving results from the maximizing behaviour of individual households.

  20. Simulations of the soil moisture dynamics in the small scale forested catchment using mesoscale hydrological model

    Czech Academy of Sciences Publication Activity Database

    Šípek, Václav

    2012-01-01

    Roč. 14, - (2012), s. 4791 ISSN 1607-7962. [European Geosciences Union General Assembly 2012. 22.04.2012-27.04.2012, Vienna] R&D Projects: GA AV ČR IAA300600901 Institutional research plan: CEZ:AV0Z20600510 Keywords : soil moisture * hydrological modelling * small catchment Subject RIV: DA - Hydrology ; Limnology

  1. Landslide model performance in a high resolution small-scale landscape

    NARCIS (Netherlands)

    Sy, De V.; Schoorl, J.M.; Keesstra, S.D.; Jones, K.E.; Claessens, L.F.G.

    2013-01-01

    The frequency and severity of shallow landslides in New Zealand threatens life and property, both on- and off-site. The physically-based shallow landslide model LAPSUS-LS is tested for its performance in simulating shallow landslide locations induced by a high intensity rain event in a small-scale

  2. Small-signal model of a decoupled double synchronous reference frame current controller

    DEFF Research Database (Denmark)

    Dowlatabadi, Mohammadkazem Bakhshizadeh; Hjerrild, Jester; Kocewiak, Lukasz

    2016-01-01

    the dq signals are not dc anymore, and therefore, linearization cannot be done. In this paper a Decoupled Double Synchronous Frame PLL is used to eliminate the oscillations in the dq frame signals. The small signal model of this PLL including an unbalanced current controller is presented in this paper....

  3. Studying the Immunomodulatory Effects of Small Molecule Ras-Inhibitors in Animal Models of Rheumatoid Arthritis

    Science.gov (United States)

    2017-10-01

    pre-clinical animal models of autoimmune. For example, FTS can attenuate disease manifestations in experimental autoimmune encephalo- myelitis (34...the clinical score of the disease; however, the biology behind the effect of FTS was not comprehensively elucidated. AIA is an experimental animal ...AWARD NUMBER: W81XWH-14-1-0609 TITLE: Studying the Immunomodulatory Effects of Small Molecule Ras-Inhibitors in Animal Models of Rheumatoid

  4. Estimating DSGE model parameters in a small open economy: Do real-time data matter?

    Directory of Open Access Journals (Sweden)

    Capek Jan

    2015-03-01

    Full Text Available This paper investigates the differences between parameters estimated using real-time and those estimated with revised data. The models used are New Keynesian DSGE models of the Czech, Polish, Hungarian, Swiss, and Swedish small open economies in interaction with the euro area. The paper also offers an analysis of data revisions of GDP growth and inflation and trend revisions of interest rates.

  5. Small-Signal Modeling and Analysis of Grid-Connected Inverter with Power Differential Droop Control

    OpenAIRE

    Chen, Xin; Zhang, Changhua; Huang, Qi; Ofori-Oduro, Mark

    2016-01-01

    The conventional voltage and frequency droop control strategy in grid-connected inverter suffers a major setback in the presence of disturbance by producing oscillations. Adding a power differential term in droop controller is an effective way to address such drawback. In this paper, grid-connected inverter’s small-signal models of the conventional droop control and the power differential droop control are established. The eigenvalues of the models are then determined by system matrix. The ei...

  6. Estimation of thawing cryolithic area with numerical modeling in 3D geometry while exploiting underground small nuclear power plant

    Directory of Open Access Journals (Sweden)

    Melnikov N. N.

    2016-03-01

    Full Text Available The paper presents results on 3D numerical calculation of a thermal task related to assessing a thawing area when placing modules with reactor and steam-turbine facility of a small nuclear power plant in thickness of permafrost rocks. The paper discusses influence of the coefficient of thermal conductivity for large-scaled underground excavations lining and cryolithic area porosity on thawing depth and front movement velocity under different spatial directions

  7. An Optimal Strategic Business Model for Small Businesses Using Online Platforms

    Directory of Open Access Journals (Sweden)

    Hana Kim

    2018-02-01

    Full Text Available As ecommerce continues to grow, small businesses are using a variety of platforms to secure potential consumers. However, it is important for small business owners to choose an efficient business model because of constraints such as technical problems. In this study, based on platform characteristics we divide online shopping platforms into different types as follows: (1 information brokerage services; (2 online malls; and (3 omni-channel platforms. The efficiency of each group is measured by stochastic frontier analysis, and the efficiency comparison between the groups is made using meta-frontier analysis. As a result of the study, it is found that the efficiency of small business owners increases as functional integration increases, satisfying utilitarian motivations. However, a platform with greater integration that has a social presence satisfying hedonic motivations improves the efficiency of all small businesses using the platform instead of just the efficiency of a marginal number of small business owners. This study, based on the dynamic capabilities viewpoint, suggests that the omni-channel platform represents the most sustainable approach for small business owners undergoing difficulties such as technological and organizational changes.

  8. Movement ecology of migration in turkey vultures.

    Science.gov (United States)

    Mandel, J T; Bildstein, K L; Bohrer, G; Winkler, D W

    2008-12-09

    We develop individual-based movement ecology models (MEM) to explore turkey vulture (Cathartes aura) migration decisions at both hourly and daily scales. Vulture movements in 10 migration events were recorded with satellite-reporting GPS sensors, and flight behavior was observed visually, aided by on-the-ground VHF radio-tracking. We used the North American Regional Reanalysis dataset to obtain values for wind speed, turbulent kinetic energy (TKE), and cloud height and used a digital elevation model for a measure of terrain ruggedness. A turkey vulture fitted with a heart-rate logger during 124 h of flight during 38 contiguous days showed only a small increase in mean heart rate as distance traveled per day increased, which suggests that, unlike flapping, soaring flight does not lead to greatly increased metabolic costs. Data from 10 migrations for 724 hourly segments and 152 daily segments showed that vultures depended heavily upon high levels of TKE in the atmospheric boundary layer to increase flight distances and maintain preferred bearings at both hourly and daily scales. We suggest how the MEM can be extended to other spatial and temporal scales of avian migration. Our success in relating model-derived atmospheric variables to migration indicates the potential of using regional reanalysis data, as here, and potentially other regional, higher-resolution, atmospheric models in predicting changing movement patterns of soaring birds under various scenarios of climate and land use change.

  9. Model for defining the level of implementation of the management functions in small enterprises

    Directory of Open Access Journals (Sweden)

    Dragan Mišetić

    2001-01-01

    Full Text Available Small enterprises, based on private ownership and entrepreneurial capability, represent, for the majority of the scientific and professional public, the prime movers of economic growth, both in developed market economies and in the economies of countries in transition. At the same time, various studies show that the main reason for the bankruptcy of many small enterprises (more than 90% can be found in weak management, i.e. unacquaintance with management functions (planning, organization, human resources management, leading and control and with the need of implementing those functions in practice. Although it is not easy to define the ingredients of the recipe for success or to define precisely the importance of different elements, and regardless of the fact that many authors think that the management theory for large enterprises is inapplicable for the small ones, we all agree that the owner/manager and his implementation of the management theory has a decisive influence on small enterprises in modern economic circumstances. Therefore, the author of this work is hereby representing the model, which defines the level of implementation of management functions in small enterprises, as well as three systems/levels (danger, risk, progress in which small enterprises may find themselves. After the level of implementation of the management function is identified, it is possible to undertake some corrective actions, which will remove the found failures. While choosing the variables of the model, the author took into consideration specific features of a small enterprise, as well as specific features of its owner/manager.

  10. A three-paradigm treatment model using soft tissue mobilization and guided movement-awareness techniques for a patient with chronic low back pain: a case study.

    Science.gov (United States)

    Cottingham, J T; Maitland, J

    1997-09-01

    It is not uncommon for physical therapists to report difficulty in treating certain subjects with chronic idiopathic low back pain. The purpose of this case study is to present a three-paradigm model of intervention that may be adapted to the treatment of such cases. The model consists of: 1) relaxation paradigm, consisting of pain modulation procedures; 2) corrective paradigm, involving manual techniques and exercise to correct specific faulty biomechanical alignment(s) eg., pelvic asymmetry); and 3) integrative paradigm, utilizing guided movement/mobilization techniques for improving the subject's overall pattern of posture and movement. The case study of a young adult with chronic low back pain correlated with unilateral innominate bone rotation is presented to illustrate the three-paradigm approach. Over six sessions, the subject received a corrective (sessions 1-3) and an integrative treatment protocol (sessions 4-6) consisting of Rolf's method of soft tissue mobilization and Alexander's system of guided movement-awareness techniques. Before and after each session and after a 4-week follow-up, the subject was assessed for sacroiliac joint pain using a compression technique, anterior rotation of the innominate bones, pelvic angle in the standing position, and vagal tone as determined from heart rate variability. The therapist's visual analysis of sit-to-stand movement and the subject's self-reports of pain were noted. A corrective paradigm protocol of soft tissue mobilization and exercise was unsuccessful in eliminating the subject's assessed anterior rotation of the innominate bone and associated low back pain for more than 1-2 days posttreatment. Only after the implementation of a third paradigm movement/mobilization protocol did the subject begin to exhibit sustained improvement through a 4-week follow-up. Interpretations of the results, appropriate selection of corrective and integrative protocols, and physiological mechanisms are discussed.

  11. Exploiting Human Resource Requirements to Infer Human Movement Patterns for Use in Modelling Disease Transmission Systems: An Example from Eastern Province, Zambia.

    Directory of Open Access Journals (Sweden)

    Simon Alderton

    Full Text Available In this research, an agent-based model (ABM was developed to generate human movement routes between homes and water resources in a rural setting, given commonly available geospatial datasets on population distribution, land cover and landscape resources. ABMs are an object-oriented computational approach to modelling a system, focusing on the interactions of autonomous agents, and aiming to assess the impact of these agents and their interactions on the system as a whole. An A* pathfinding algorithm was implemented to produce walking routes, given data on the terrain in the area. A* is an extension of Dijkstra's algorithm with an enhanced time performance through the use of heuristics. In this example, it was possible to impute daily activity movement patterns to the water resource for all villages in a 75 km long study transect across the Luangwa Valley, Zambia, and the simulated human movements were statistically similar to empirical observations on travel times to the water resource (Chi-squared, 95% confidence interval. This indicates that it is possible to produce realistic data regarding human movements without costly measurement as is commonly achieved, for example, through GPS, or retrospective or real-time diaries. The approach is transferable between different geographical locations, and the product can be useful in providing an insight into human movement patterns, and therefore has use in many human exposure-related applications, specifically epidemiological research in rural areas, where spatial heterogeneity in the disease landscape, and space-time proximity of individuals, can play a crucial role in disease spread.

  12. A Multifractal Detrended Fluctuation Analysis of the Ising Financial Markets Model with Small World Topology

    International Nuclear Information System (INIS)

    Zhang Ang-Hui; Li Xiao-Wen; Su Gui-Feng; Zhang Yi

    2015-01-01

    We present a multifractal detrended fluctuation analysis (MFDFA) of the time series of return generated by our recently-proposed Ising financial market model with underlying small world topology. The result of the MFDFA shows that there exists obvious multifractal scaling behavior in produced time series. We compare the MFDFA results for original time series with those for shuffled series, and find that its multifractal nature is due to two factors: broadness of probability density function of the series and different correlations in small- and large-scale fluctuations. This may provide new insight to the problem of the origin of multifractality in financial time series. (paper)

  13. A phase transition between small- and large-field models of inflation

    International Nuclear Information System (INIS)

    Itzhaki, Nissan; Kovetz, Ely D

    2009-01-01

    We show that models of inflection point inflation exhibit a phase transition from a region in parameter space where they are of large-field type to a region where they are of small-field type. The phase transition is between a universal behavior, with respect to the initial condition, at the large-field region and non-universal behavior at the small-field region. The order parameter is the number of e-foldings. We find integer critical exponents at the transition between the two phases.

  14. Evaluation of remotely sensed actual evapotranspiration data for modeling small scale irrigation in Ethiopia.

    Science.gov (United States)

    Taddele, Y. D.; Ayana, E.; Worqlul, A. W.; Srinivasan, R.; Gerik, T.; Clarke, N.

    2017-12-01

    The research presented in this paper is conducted in Ethiopia, which is located in the horn of Africa. Ethiopian economy largely depends on rainfed agriculture, which employs 80% of the labor force. The rainfed agriculture is frequently affected by droughts and dry spells. Small scale irrigation is considered as the lifeline for the livelihoods of smallholder farmers in Ethiopia. Biophysical models are highly used to determine the agricultural production, environmental sustainability, and socio-economic outcomes of small scale irrigation in Ethiopia. However, detailed spatially explicit data is not adequately available to calibrate and validate simulations from biophysical models. The Soil and Water Assessment Tool (SWAT) model was setup using finer resolution spatial and temporal data. The actual evapotranspiration (AET) estimation from the SWAT model was compared with two remotely sensed data, namely the Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectrometer (MODIS). The performance of the monthly satellite data was evaluated with correlation coefficient (R2) over the different land use groups. The result indicated that over the long term and monthly the AVHRR AET captures the pattern of SWAT simulated AET reasonably well, especially on agricultural dominated landscapes. A comparison between SWAT simulated AET and AVHRR AET provided mixed results on grassland dominated landscapes and poor agreement on forest dominated landscapes. Results showed that the AVHRR AET products showed superior agreement with the SWAT simulated AET than MODIS AET. This suggests that remotely sensed products can be used as valuable tool in properly modeling small scale irrigation.

  15. Hierarchical Bayes Small Area Estimation under a Unit Level Model with Applications in Agriculture

    Directory of Open Access Journals (Sweden)

    Nageena Nazir

    2016-09-01

    Full Text Available To studied Bayesian aspect of small area estimation using Unit level model. In this paper we proposed and evaluated new prior distribution for the ratio of variance components in unit level model rather than uniform prior. To approximate the posterior moments of small area means, Laplace approximation method is applied. This choice of prior avoids the extreme skewness, usually present in the posterior distribution of variance components. This property leads to more accurate Laplace approximation. We apply the proposed model to the analysis of horticultural data and results from the model are compared with frequestist approach and with Bayesian model of uniform prior in terms of average relative bias, average squared relative bias and average absolute bias. The numerical results obtained highlighted the superiority of using the proposed prior over the uniform prior. Thus Bayes estimators (with new prior of small area means have good frequentist properties such as MSE and ARB as compared to other traditional methods viz., Direct, Synthetic and Composite estimators.

  16. Small-Signal Modeling and Analysis of Grid-Connected Inverter with Power Differential Droop Control

    Directory of Open Access Journals (Sweden)

    Xin Chen

    2016-01-01

    Full Text Available The conventional voltage and frequency droop control strategy in grid-connected inverter suffers a major setback in the presence of disturbance by producing oscillations. Adding a power differential term in droop controller is an effective way to address such drawback. In this paper, grid-connected inverter’s small-signal models of the conventional droop control and the power differential droop control are established. The eigenvalues of the models are then determined by system matrix. The eigenvalues analysis is presented which helps in identifying the relationship between the system stability and controller parameters. It is concluded that the damping ratio of dominant low-frequency eigenvalues increased and the oscillation caused by the disturbance is suppressed when a power differential term is added to the droop control method. The MATLAB/Simulink models of grid-connected inverter with both control strategies are also established to validate the results of small-signal analysis.

  17. Small Signal Modeling and Comprehensive Analysis of Magnetically Coupled Impedance Source Converters

    DEFF Research Database (Denmark)

    Forouzesh, Mojtaba; Siwakoti, Yam Prasad; Blaabjerg, Frede

    2016-01-01

    applications; however, due to effective role of system modeling in the closed-loop controller design, this paper is allocated to small-signal modeling and analysis of MCIS converters. The modeling is performed by means of the circuit averaging and averaged switch technique. A generalized small......-signal derivation is demonstrated for pulse width modulation (PWM) MCIS converters and it is shown that the derived transfer functions can simply be applied to Y-source, Γ-source, and T-source impedance networks. Various transfer functions for capacitor voltage, output voltage, magnetizing current, input and output...... impedance are derived and have been validated through frequency and dynamic responses of computer simulation results. In addition, a comprehensive analysis has been done for all mentioned PWM MCIS converters regarding their circuit parameters. Furthermore, the effect of considering the equivalent series...

  18. Self-organizing Ising model of artificial financial markets with small-world network topology

    Science.gov (United States)

    Zhao, Haijie; Zhou, Jie; Zhang, Anghui; Su, Guifeng; Zhang, Yi

    2013-01-01

    We study a self-organizing Ising-like model of artificial financial markets with underlying small-world (SW) network topology. The asset price dynamics results from the collective decisions of interacting agents which are located on a small-world complex network (the nodes symbolize the agents of a financial market). The model incorporates the effects of imitation, the impact of external news and private information. We also investigate the influence of different network topologies, from regular lattice to random graph, on the asset price dynamics by adjusting the probability of the rewiring procedure. We find that a specific combination of model parameters reproduce main stylized facts of real-world financial markets.

  19. On Spatial Resolution in Habitat Models: Can Small-scale Forest Structure Explain Capercaillie Numbers?

    Directory of Open Access Journals (Sweden)

    Ilse Storch

    2002-06-01

    Full Text Available This paper explores the effects of spatial resolution on the performance and applicability of habitat models in wildlife management and conservation. A Habitat Suitability Index (HSI model for the Capercaillie (Tetrao urogallus in the Bavarian Alps, Germany, is presented. The model was exclusively built on non-spatial, small-scale variables of forest structure and without any consideration of landscape patterns. The main goal was to assess whether a HSI model developed from small-scale habitat preferences can explain differences in population abundance at larger scales. To validate the model, habitat variables and indirect sign of Capercaillie use (such as feathers or feces were mapped in six study areas based on a total of 2901 20 m radius (for habitat variables and 5 m radius sample plots (for Capercaillie sign. First, the model's representation of Capercaillie habitat preferences was assessed. Habitat selection, as expressed by Ivlev's electivity index, was closely related to HSI scores, increased from poor to excellent habitat suitability, and was consistent across all study areas. Then, habitat use was related to HSI scores at different spatial scales. Capercaillie use was best predicted from HSI scores at the small scale. Lowering the spatial resolution of the model stepwise to 36-ha, 100-ha, 400-ha, and 2000-ha areas and relating Capercaillie use to aggregated HSI scores resulted in a deterioration of fit at larger scales. Most importantly, there were pronounced differences in Capercaillie abundance at the scale of study areas, which could not be explained by the HSI model. The results illustrate that even if a habitat model correctly reflects a species' smaller scale habitat preferences, its potential to predict population abundance at larger scales may remain limited.

  20. On spherical symmetry modelling of DNA packing within bacteriophage heads according to small angle scattering data

    International Nuclear Information System (INIS)

    Dembo, A.T.; Tikhonychev, V.V.

    1983-01-01

    Spherical symmetry models were used for interpretation of X-ray small angle scattering curves of bacteriophage solutions. These models were built of concentric spherical layers of finite thickness with various scattering densities. The attention was attached to the ripple intensity of DNA packing maximum. In model calculations such parameters as external radius, scattering densities, number of DNA-imitating layers and internal radii were changed. The results show that the fine structure of DNA packing maximum depends on the overall shape and size of the region occupied by DNA inside the bacteriophage head. (author)