Science.gov

Sample records for coordination dynamics measuring

  1. A new approach on restoration of dynamic measurement uncertainties in optical precision coordinate metrology

    NASA Astrophysics Data System (ADS)

    Holder, S.; Reetz, E.; Linß, G.

    2015-02-01

    This paper presents a new approach to the restoration of dynamic influenced measurement uncertainties in optical precision coordinate metrology (OPCM) using image sensors to measure geometrical features. Dynamic measurements within the context of this paper are based upon relative motion between the imaging setup (CCD-camera and optical system) and the measuring object respectively the measuring scene. The dynamic image acquisition causes image motion blur effects, which downgrades the uncertainties of the measurand. The approach presented deals with a new technique to restore motion degraded images using different methods to analyze important image features by extending the famous state of the art Richardson-Lucy image restoration technique using a new convergence criteria based on the variation of the detectable sub-pixel edge position of each iteration.

  2. Team coordination dynamics.

    PubMed

    Gorman, Jamie C; Amazeen, Polemnia G; Cooke, Nancy J

    2010-07-01

    Team coordination consists of both the dynamics of team member interaction and the environmental dynamics to which a team is subjected. Focusing on dynamics, an approach is developed that contrasts with traditional aggregate-static concepts of team coordination as characterized by the shared mental model approach. A team coordination order parameter was developed to capture momentary fluctuations in coordination. Team coordination was observed in three-person uninhabited air vehicle teams across two experimental sessions. The dynamics of the order parameter were observed under changes of a team familiarity control parameter. Team members returned for the second session to either the same (Intact) or different (Mixed) team. 'Roadblock' perturbations, or novel changes in the task environment, were introduced in order to probe the stability of team coordination. Nonlinear dynamic methods revealed differences that a traditional approach did not: Intact and Mixed team coordination dynamics looked very different; Mixed teams were more stable than Intact teams and explored the space of solutions without the need for correction. Stability was positively correlated with the number of roadblock perturbations that were overcome successfully. The novel and non-intuitive contribution of a dynamical analysis was that Mixed teams, who did not have a long history working together, were more adaptive. Team coordination dynamics carries new implications for traditional problems such as training adaptive teams. PMID:20587302

  3. Study of coordinate measuring machines synthetic dynamic error under different positions and speeds based on dual linear returns

    NASA Astrophysics Data System (ADS)

    Ma, Xiushui; Fei, Yetai; Wang, Hongtao; Ying, Zhongyang; Li, Guang

    2006-11-01

    Modern manufacturing increasingly places a high requirement on the speed and accuracy of Coordinate Measuring Machines (CMMs). Measuring speed has become one of the key factors in evaluating the performance of CMMs. In high speed measuring, dynamic error will have a greater influence on accuracy. This paper tests the dynamic error of CMM's measuring system under different measuring positions and speeds using the dual frequency laser interferometer. Based on measured data, the modeling of synthetic dynamic errors is set up adopting the dual linear returns method. Comparing with the measured data, the relative error of modeling is between 15% to 20%, the returns equation is prominent at α=0.01 level, verified by "F". Based on the modeling of synthetic dynamic errors under different measuring positions and speeds, the measuring system dynamic error of CMMs is corrected and reduced.

  4. Information theoretic measures of network coordination in high-frequency scalp EEG reveal dynamic patterns associated with seizure termination.

    PubMed

    Stamoulis, Catherine; Schomer, Donald L; Chang, Bernard S

    2013-08-01

    How a seizure terminates is still under-studied and, despite its clinical importance, remains an obscure phase of seizure evolution. Recent studies of seizure-related scalp EEGs at frequencies >100 Hz suggest that neural activity, in the form of oscillations and/or neuronal network interactions, may play an important role in preictal/ictal seizure evolution (Andrade-Valenca et al., 2011; Stamoulis et al., 2012). However, the role of high-frequency activity in seizure termination, is unknown, if it exists at all. Using information theoretic measures of network coordination, this study investigated ictal and immediate postictal neurodynamic interactions encoded in scalp EEGs from a relatively small sample of 8 patients with focal epilepsy and multiple seizures originating in temporal and/or frontal brain regions, at frequencies ≤ 100 Hz and >100 Hz, respectively. Despite some heterogeneity in the dynamics of these interactions, consistent patterns were also estimated. Specifically, in several seizures, linear or non-linear increase in high-frequency neuronal coordination during ictal intervals, coincided with a corresponding decrease in coordination at frequencies <100 Hz, suggesting a potential interference role of high-frequency activity, to disrupt abnormal ictal synchrony at lower frequencies. These changes in network synchrony started at least 20-30s prior to seizure offset, depending on the seizure duration. Opposite patterns were estimated at frequencies ≤ 100 Hz in several seizures. These results raise the possibility that high-frequency interference may occur in the form of progressive network coordination during the ictal interval, which continues during the postictal interval. This may be one of several possible mechanisms that facilitate seizure termination. In fact, inhibition of pairwise interactions between EEGs by other signals in their spatial neighborhood, quantified by negative interaction information, was estimated at frequencies ≤ 100 Hz

  5. Coordinate Standard Measurement Development

    SciTech Connect

    Hanshaw, R.A.

    2000-02-18

    A Shelton Precision Interferometer Base, which is used for calibration of coordinate standards, was improved through hardware replacement, software geometry error correction, and reduction of vibration effects. Substantial increases in resolution and reliability, as well as reduction in sampling time, were achieved through hardware replacement; vibration effects were reduced substantially through modification of the machine component dampening and software routines; and the majority of the machine's geometry error was corrected through software geometry error correction. Because of these modifications, the uncertainty of coordinate standards calibrated on this device has been reduced dramatically.

  6. Coordinate measuring system

    DOEpatents

    Carlisle, Keith

    2003-04-08

    An apparatus and method is utilized to measure relative rigid body motion between two bodies by measuring linear motion in the principal axis and linear motion in an orthogonal axis. From such measurements it is possible to obtain displacement, departure from straightness, and angular displacement from the principal axis of a rigid body.

  7. Measuring motor coordination in mice.

    PubMed

    Deacon, Robert M J

    2013-01-01

    Mice are increasingly being used in behavioral neuroscience, largely replacing rats as the behaviorist's animal of choice. Before aspects of behavior such as emotionality or cognition can be assessed, however, it is vital to determine whether the motor capabilities of e.g. a mutant or lesioned mouse allow such an assessment. Performance on a maze task requiring strength and coordination, such as the Morris water maze, might well be impaired in a mouse by motor, rather than cognitive, impairments, so it is essential to selectively dissect the latter from the former. For example, sensorimotor impairments caused by NMDA antagonists have been shown to impair water maze performance(2). Motor coordination has traditionally been assessed in mice and rats by the rotarod test, in which the animal is placed on a horizontal rod that rotates about its long axis; the animal must walk forwards to remain upright and not fall off. Both set speed and accelerating versions of the rotarod are available. The other three tests described in this article (horizontal bar, static rods and parallel bars) all measure coordination on static apparatus. The horizontal bar also requires strength for adequate performance, particularly of the forelimbs as the mouse initially grips the bar just with the front paws. Adult rats do not perform well on tests such as the static rods and parallel bars (personal observations); they appear less well coordinated than mice. I have only tested male rats, however, and male mice seem generally less well coordinated than females. Mice appear to have a higher strength:weight ratio than rats; the Latin name, Mus musculus, seems entirely appropriate. The rotarod, the variations of the foot fault test(12) or the Catwalk (Noldus)(15) apparatus are generally used to assess motor coordination in rats. PMID:23748408

  8. Modeling and prototyping of a fiber Bragg grating-based dynamic micro-coordinate measuring machine probe

    NASA Astrophysics Data System (ADS)

    Liu, Fangfang; Chen, Lijuan; Wang, Jingfan; Xia, Haojie; Li, Ruijun; Yu, Liandong; Fei, Yetai

    2016-02-01

    Higher-accuracy measurements of the 3D metrology of nano- and micro-structures are increasingly demanded. This paper details the prototyping of a novel 3D micro-scale coordinate measuring machine probe based on fiber Bragg grating sensors for true 3D measurements at micro- and nanometer scales. A new manufacturing technique for the high-precision cantilever used in the probe is also reported. Simulations are performed during the design and testing to help to test important aspects of the probe and to gain understanding about the influence of the probe geometrical parameters on the sensor sensitivity. The initial performance of the probe has been tested in both the vertical and horizontal directions, and the characterization results are promising. Further experimental results demonstrate that the probe is not affected by surface interaction forces.

  9. Computer aided coordinate measuring systems

    NASA Astrophysics Data System (ADS)

    Nastri, J. W.

    Sikorsky's computer-aided inspection system and equipment utilized to assure that manufactured parts meet drawing tolerance specifications are discussed. An overview of the system is given, and the software is described, including the monitor console routine and commands and the language commands. The system's three coordinate measuring machines are discussed, and the part inspection methods are described in stepwise fashion. System benefits and time savings items are detailed, including quick and accurate measurement of parts difficult to inspect by conventional methods, significant reduction in inspection time, a consistent baseline that highlights variances, and the use of personnel with lower skill levels to effectively inspect critical parts.

  10. Concurrent Cognitive Task Modulates Coordination Dynamics

    ERIC Educational Resources Information Center

    Pellecchia, Geraldine L.; Shockley, Kevin; Turvey, M. T.

    2005-01-01

    Does a concurrent cognitive task affect the dynamics of bimanual rhythmic coordination? In-phase coordination was performed under manipulations of phase detuning and movement frequency and either singly or in combination with an arithmetic task. Predicted direction-specific shifts in stable relative phase from 0 degrees due to detuning and…

  11. Neuroimaging Coordination Dynamics in the Sport Sciences

    PubMed Central

    Jantzen, Kelly J.; Oullier, Olivier; Kelso, J.A. Scott

    2008-01-01

    Key methodological issues for designing, analyzing, and interpreting neuroimaging experiments are presented from the perspective of the framework of Coordination Dynamics. To this end, a brief overview of Coordination Dynamics is introduced, including the main concepts of control parameters and collective variables, theoretical modeling, novel experimental paradigms, and cardinal empirical findings. Basic conceptual and methodological issues for the design and implementation of coordination experiments in the context of neuroimaging are discussed. The paper concludes with a presentation of neuroimaging findings central to understanding the neural basis of coordination and addresses their relevance for the sport sciences. The latter include but are not restricted to learning and practice-related issues, the role of mental imagery, and the recovery of function following brain injury. PMID:18602998

  12. The coordination dynamics of social neuromarkers

    PubMed Central

    Tognoli, Emmanuelle; Kelso, J. A. Scott

    2015-01-01

    Social behavior is a complex integrative function that entails many aspects of the brain’s sensory, cognitive, emotional and movement capacities. Its neural processes are seldom simultaneous but occur according to precise spatiotemporal choreographies, manifested by the coordination of their oscillations within and between brains. Methods with good temporal resolution can help to identify so-called “neuromarkers” of social function and aid in disentangling the dynamical architecture of social brains. In our ongoing research, we have used dual-electroencephalography (EEG) to study neuromarker dynamics during synchronic interactions in which pairs of subjects coordinate behavior spontaneously and intentionally (social coordination) and during diachronic transactions that require subjects to perceive or behave in turn (action observation, delayed imitation). In this paper, after outlining our dynamical approach to the neurophysiological basis of social behavior, we examine commonalities and differences in the neuromarkers that are recruited for both kinds of tasks. We find the neuromarker landscape to be task-specific: synchronic paradigms of social coordination reveal medial mu, alpha and the phi complex as contributing neuromarkers. Diachronic tasks recruit alpha as well, in addition to lateral mu rhythms and the newly discovered nu and kappa rhythms whose functional significance is still unclear. Social coordination, observation, and delayed imitation share commonality of context: in each of our experiments, subjects exchanged information through visual perception and moved in similar ways. Nonetheless, there was little overlap between their neuromarkers, a result that hints strongly of task-specific neural mechanisms for social behavior. The only neuromarker that transcended both synchronic and diachronic social behaviors was the ubiquitous alpha rhythm, which appears to be a key signature of visually-mediated social behaviors. The present paper is both an

  13. A dynamic human motion: coordination analysis.

    PubMed

    Pchelkin, Stepan; Shiriaev, Anton S; Freidovich, Leonid B; Mettin, Uwe; Gusev, Sergei V; Kwon, Woong; Paramonov, Leonid

    2015-02-01

    This article is concerned with the generic structure of the motion coordination system resulting from the application of the method of virtual holonomic constraints (VHCs) to the problem of the generation and robust execution of a dynamic humanlike motion by a humanoid robot. The motion coordination developed using VHCs is based on a motion generator equation, which is a scalar nonlinear differential equation of second order. It can be considered equivalent in function to a central pattern generator in living organisms. The relative time evolution of the degrees of freedom of a humanoid robot during a typical motion are specified by a set of coordination functions that uniquely define the overall pattern of the motion. This is comparable to a hypothesis on the existence of motion patterns in biomechanics. A robust control is derived based on a transverse linearization along the configuration manifold defined by the coordination functions. It is shown that the derived coordination and control architecture possesses excellent robustness properties. The analysis is performed on an example of a real human motion recorded in test experiments. PMID:25158624

  14. Highly accurate articulated coordinate measuring machine

    DOEpatents

    Bieg, Lothar F.; Jokiel, Jr., Bernhard; Ensz, Mark T.; Watson, Robert D.

    2003-12-30

    Disclosed is a highly accurate articulated coordinate measuring machine, comprising a revolute joint, comprising a circular encoder wheel, having an axis of rotation; a plurality of marks disposed around at least a portion of the circumference of the encoder wheel; bearing means for supporting the encoder wheel, while permitting free rotation of the encoder wheel about the wheel's axis of rotation; and a sensor, rigidly attached to the bearing means, for detecting the motion of at least some of the marks as the encoder wheel rotates; a probe arm, having a proximal end rigidly attached to the encoder wheel, and having a distal end with a probe tip attached thereto; and coordinate processing means, operatively connected to the sensor, for converting the output of the sensor into a set of cylindrical coordinates representing the position of the probe tip relative to a reference cylindrical coordinate system.

  15. Internal Coordinate Molecular Dynamics: A Foundation for Multiscale Dynamics

    PubMed Central

    2015-01-01

    Internal coordinates such as bond lengths, bond angles, and torsion angles (BAT) are natural coordinates for describing a bonded molecular system. However, the molecular dynamics (MD) simulation methods that are widely used for proteins, DNA, and polymers are based on Cartesian coordinates owing to the mathematical simplicity of the equations of motion. However, constraints are often needed with Cartesian MD simulations to enhance the conformational sampling. This makes the equations of motion in the Cartesian coordinates differential-algebraic, which adversely impacts the complexity and the robustness of the simulations. On the other hand, constraints can be easily placed in BAT coordinates by removing the degrees of freedom that need to be constrained. Thus, the internal coordinate MD (ICMD) offers an attractive alternative to Cartesian coordinate MD for developing multiscale MD method. The torsional MD method is a special adaptation of the ICMD method, where all the bond lengths and bond angles are kept rigid. The advantages of ICMD simulation methods are the longer time step size afforded by freezing high frequency degrees of freedom and performing a conformational search in the more important low frequency torsional degrees of freedom. However, the advancements in the ICMD simulations have been slow and stifled by long-standing mathematical bottlenecks. In this review, we summarize the recent mathematical advancements we have made based on spatial operator algebra, in developing a robust long time scale ICMD simulation toolkit useful for various applications. We also present the applications of ICMD simulations to study conformational changes in proteins and protein structure refinement. We review the advantages of the ICMD simulations over the Cartesian simulations when used with enhanced sampling methods and project the future use of ICMD simulations in protein dynamics. PMID:25517406

  16. Generalized Geometric Error Correction in Coordinate Measurement

    NASA Astrophysics Data System (ADS)

    Hermann, Gyula

    Software compensation of geometric errors in coordinate measuring is hot subject because it results the decrease of manufacturing costs. The paper gives a summary of the results and achievements of earlier works on the subject. In order to improve these results a method is adapted to capture simultaneously the new coordinate frames in order use exact transformation values at discrete points of the measuring volume. The interpolation techniques published in the literature have the draw back that they could not maintain the orthogonality of the rotational part of the transformation matrices. The paper gives a technique, based on quaternions, which avoid this problem and leads to better results.

  17. Dynamic similarity promotes interpersonal coordination in joint action

    PubMed Central

    Słowiński, Piotr; Zhai, Chao; Alderisio, Francesco; Salesse, Robin; Gueugnon, Mathieu; Marin, Ludovic; Bardy, Benoit G.; di Bernardo, Mario; Tsaneva-Atanasova, Krasimira

    2016-01-01

    Human movement has been studied for decades, and dynamic laws of motion that are common to all humans have been derived. Yet, every individual moves differently from everyone else (faster/slower, harder/smoother, etc.). We propose here an index of such variability, namely an individual motor signature (IMS) able to capture the subtle differences in the way each of us moves. We show that the IMS of a person is time-invariant and that it significantly differs from those of other individuals. This allows us to quantify the dynamic similarity, a measure of rapport between dynamics of different individuals' movements, and demonstrate that it facilitates coordination during interaction. We use our measure to confirm a key prediction of the theory of similarity that coordination between two individuals performing a joint-action task is higher if their motions share similar dynamic features. Furthermore, we use a virtual avatar driven by an interactive cognitive architecture based on feedback control theory to explore the effects of different kinematic features of the avatar motion on coordination with human players. PMID:27009178

  18. Dynamic similarity promotes interpersonal coordination in joint action.

    PubMed

    Słowiński, Piotr; Zhai, Chao; Alderisio, Francesco; Salesse, Robin; Gueugnon, Mathieu; Marin, Ludovic; Bardy, Benoit G; di Bernardo, Mario; Tsaneva-Atanasova, Krasimira

    2016-03-01

    Human movement has been studied for decades, and dynamic laws of motion that are common to all humans have been derived. Yet, every individual moves differently from everyone else (faster/slower, harder/smoother, etc.). We propose here an index of such variability, namely an individual motor signature (IMS) able to capture the subtle differences in the way each of us moves. We show that the IMS of a person is time-invariant and that it significantly differs from those of other individuals. This allows us to quantify the dynamic similarity, a measure of rapport between dynamics of different individuals' movements, and demonstrate that it facilitates coordination during interaction. We use our measure to confirm a key prediction of the theory of similarity that coordination between two individuals performing a joint-action task is higher if their motions share similar dynamic features. Furthermore, we use a virtual avatar driven by an interactive cognitive architecture based on feedback control theory to explore the effects of different kinematic features of the avatar motion on coordination with human players. PMID:27009178

  19. The coordination dynamics of mobile conjugate reinforcement.

    PubMed

    Kelso, J A Scott; Fuchs, Armin

    2016-02-01

    What we know about infant learning and memory is founded largely on systematic studies by the late Carolyn Rovee-Collier (1942-2014) and her associates of a phenomenon called mobile conjugate reinforcement. Experiments show that when a ribbon is attached from a 3-month-old infant's foot to a mobile suspended overhead the baby quickly realizes it can make the mobile move. The mobile, which offers interesting sights and sounds, responds conjugately to the baby's vigorous kicks which increase in rate by a factor of 3-4. In this paper, using the concepts, methods and tools of coordination dynamics, we present a theoretical model which reproduces the experimental observations of Rovee-Collier and others and predicts a number of additional features that can be experimentally tested. The model is a dynamical system consisting of three equations, one for the baby's leg movements, one for the jiggling motion of the mobile and one for the functional coupling between the two. A key mechanism in the model is positive feedback which is shown to depend sensitively on bifurcation parameters related to the infant's level of attention and inertial properties of the mobile. The implications of our model for the dynamical (and developmental) origins of agency are discussed. PMID:26759265

  20. Conservative-coordinate transformations for atmospheric measurements

    NASA Technical Reports Server (NTRS)

    Schoeberl, M. R.; Lait, L. R.

    1992-01-01

    This lecture describes a technique by which atmospheric measurements of trace species with medium to long lifetimes can be 'coincidentally' compared and validated even though measurements are taken at different locations and different times In other words, the method, under suitable counditions, can remove a large amount of the natural meteorological variability. The technique involves the use of quasi-Lagrangian or conservative coordinates - air parcel tags which are invariant or nearly invariant under the motion of the parcel. The technique is called 'reconstruction', since measurements taken at one location can be reconstructed at different locations. In order to do this, the data are transformed into the conservative coordinates and accumulated. Within the conservative reference frame, much of the meteorological variability is removed. Once enough data are obtained within the system, the observations can be tranformed back into physical space at any location and compared with other measurements. The method by which the trace species data are obtained makes no difference; satellite, balloon, rocket, aircraft and ground-based data all become equivalent and can be intercompared. The conservative-coordinate system not only allows for intercomparison of data, but shows how data can be taken in such a way as to maximize the physical scope of the information. In other words, the method automatically suggests when conditions might be suitable to obtain information with different environmental situations. It also allows for the forecast of constituent fields using only the meteorological forecasts and limited observational data.

  1. Coordinate measurement machines as an alignment tool

    SciTech Connect

    Wand, B.T.

    1991-03-01

    In February of 1990 the Stanford Linear Accelerator Center (SLAC) purchased a LEITZ PM 12-10-6 CMM (Coordinate measurement machine). The machine is shared by the Quality Control Team and the Alignment Team. One of the alignment tasks in positioning beamline components in a particle accelerator is to define the component's magnetic centerline relative to external fiducials. This procedure, called fiducialization, is critical to the overall positioning tolerance of a magnet. It involves the definition of the magnetic center line with respect to the mechanical centerline and the transfer of the mechanical centerline to the external fiducials. To perform the latter a magnet coordinate system has to be established. This means defining an origin and the three rotation angles of the magnet. The datum definition can be done by either optical tooling techniques or with a CMM. As optical tooling measurements are very time consuming, not automated and are prone to errors, it is desirable to use the CMM fiducialization method instead. The establishment of a magnet coordinate system based on the mechanical center and the transfer to external fiducials will be discussed and presented with 2 examples from the Stanford Linear Collider (SLC). 7 figs.

  2. A heart for interaction: Shared physiological dynamics and behavioral coordination in a collective, creative construction task.

    PubMed

    Fusaroli, Riccardo; Bjørndahl, Johanne S; Roepstorff, Andreas; Tylén, Kristian

    2016-09-01

    Interpersonally shared physiological dynamics are increasingly argued to underlie rapport, empathy, and even team performance. Inspired by the model of interpersonal synergy, we critically investigate the presence, temporal development, possible mechanisms and impact of shared interpersonal heart rate (HR) dynamics during individual and collective creative LEGO® construction tasks. In Study 1 we show how shared HR dynamics are driven by a plurality of sources, including task constraints and behavioral coordination. Generally, shared HR dynamics are more prevalent in individual trials (involving participants doing the same things) than in collective ones (involving participants taking turns and performing complementary actions). However, when contrasted against virtual pairs, collective trials display more stable shared HR dynamics suggesting that online social interaction plays an important role. Furthermore, in contrast to individual trials, shared HR dynamics are found to increase across collective trials. Study 2 investigates which aspects of social interaction might drive these effects. We show that shared HR dynamics are statistically predicted by interpersonal speech and building coordination. In Study 3, we explore the relation between HR dynamics, behavioral coordination, and self-reported measures of rapport and group competence. Although behavioral coordination predicts rapport and group competence, shared HR dynamics do not. Although shared physiological dynamics were reliably observed in our study, our results warrant not to consider HR dynamics a general driving mechanism of social coordination. Behavioral coordination-on the other hand-seems to be more informative of both shared physiological dynamics and collective experience. (PsycINFO Database Record PMID:26962844

  3. Phase Retrieval Techniques In Coordinates Measurement

    SciTech Connect

    Harizanova, J. I.; Stoykova, E. V.; Sainov, V. C.

    2007-04-23

    A precise pattern projection profilometry for three-dimensional shape measurements with different methods of fringe generation is presented. The application of phase-shifting algorithm along with two-spacing illumination allow for phase retrieval and estimation of relative and absolute coordinates of the tested samples. The following experimental approaches for fringe generation are investigated: interferometric approach based on a classical Michelson interferometer, digital computation with a DMD projection and light modulation by a sinusoidal phase grating. The theoretical background, experimental results as well as comparison of the applied generation methods are analyzed. The obtained outcomes successfully display the applicability of this technique for surface profile measurement. The application of the proposed techniques for remote, non-destructive in-situ inspection of real objects from cultural heritage is discussed.

  4. Measurement, coordination, and the relativized a priori

    NASA Astrophysics Data System (ADS)

    Padovani, Flavia

    2015-11-01

    The problem of measurement is a central issue in the epistemology and methodology of the physical sciences. In recent literature on scientific representation, large emphasis has been put on the "constitutive role" played by measurement procedures as forms of representation. Despite its importance, this issue hardly finds any mention in writings on constitutive principles, viz. in Michael Friedman's account of relativized a priori principles. This issue, instead, was at the heart of Reichenbach's analysis of coordinating principles that has inspired Friedman's interpretation. This paper suggests that these procedures should have a part in an account of constitutive principles of science, and that they could be interpreted following the intuition originally present (but ultimately not fully developed) in Reichenbach's early work.

  5. Framework for coordination of activities in dynamic situations

    NASA Astrophysics Data System (ADS)

    Franke, Jörn; Charoy, François; El Khoury, Paul

    2013-02-01

    Recent disasters, such as Hurricane Katrina in 2005, have shown several issues for the coordination of human activities in these dynamic situations. Contemporary tools for the coordination used in the disaster response, such as e-mail, Whiteboards or phones, only allow for unstructured coordination, which can cause coordination problems. Hence, we discuss about the current information systems for coordinating the activities in a structured manner and identify their weaknesses in the context of a process modelling effort conducted together with experienced disaster managers. Afterwards, we propose a framework for coordination of activities in dynamic situations. The framework presented in this paper has been implemented as an extension to an open collaboration service. This shows how it can be used in the context of other tools required for disaster response management, such as maps, pictures or videos of the situation. The work described here is the foundation for enabling inter-organisational coordination of activities relevant in other domains, e.g. enterprise support processes, production processes or distributed software development projects. Furthermore, comments by disaster managers show that the concepts are relevant for their work. The expected impact is a more effective and efficient coordination of human activities in dynamic situations by structuring what needs to be coordinated.

  6. Dynamical methods for evaluating the time-dependent unfolding of social coordination in children with autism

    PubMed Central

    Fitzpatrick, Paula; Diorio, Rachel; Richardson, Michael J.; Schmidt, R. C.

    2013-01-01

    Children with Autism Spectrum Disorder (ASD) suffer from numerous impairments in social interaction that affect both their mental and bodily coordination with others. We explored here whether interpersonal motor coordination may be an important key for understanding the profound social problems of children with ASD. We employed a set of experimental techniques to evaluate not only traditional cognitive measures of social competence but also the dynamical structure of social coordination by using dynamical measures of social motor coordination and analyzing the time series records of behavior. Preliminary findings suggest that children with ASD were equivalent to typically developing children on many social performance outcome measures. However, significant relationships were found between cognitive social measures (e.g., intentionality) and dynamical social motor measures. In addition, we found that more perceptually-based measures of social coordination were not associated with social motor coordination. These findings suggest that social coordination may not be a unitary construct and point to the promise of this multi-method and process-oriented approach to analyzing social coordination as an important pathway for understanding ASD-specific social deficits. PMID:23580133

  7. Higher-Order Synaptic Interactions Coordinate Dynamics in Recurrent Networks

    PubMed Central

    Chambers, Brendan; MacLean, Jason N.

    2016-01-01

    Linking synaptic connectivity to dynamics is key to understanding information processing in neocortex. Circuit dynamics emerge from complex interactions of interconnected neurons, necessitating that links between connectivity and dynamics be evaluated at the network level. Here we map propagating activity in large neuronal ensembles from mouse neocortex and compare it to a recurrent network model, where connectivity can be precisely measured and manipulated. We find that a dynamical feature dominates statistical descriptions of propagating activity for both neocortex and the model: convergent clusters comprised of fan-in triangle motifs, where two input neurons are themselves connected. Fan-in triangles coordinate the timing of presynaptic inputs during ongoing activity to effectively generate postsynaptic spiking. As a result, paradoxically, fan-in triangles dominate the statistics of spike propagation even in randomly connected recurrent networks. Interplay between higher-order synaptic connectivity and the integrative properties of neurons constrains the structure of network dynamics and shapes the routing of information in neocortex. PMID:27542093

  8. Higher-Order Synaptic Interactions Coordinate Dynamics in Recurrent Networks.

    PubMed

    Chambers, Brendan; MacLean, Jason N

    2016-08-01

    Linking synaptic connectivity to dynamics is key to understanding information processing in neocortex. Circuit dynamics emerge from complex interactions of interconnected neurons, necessitating that links between connectivity and dynamics be evaluated at the network level. Here we map propagating activity in large neuronal ensembles from mouse neocortex and compare it to a recurrent network model, where connectivity can be precisely measured and manipulated. We find that a dynamical feature dominates statistical descriptions of propagating activity for both neocortex and the model: convergent clusters comprised of fan-in triangle motifs, where two input neurons are themselves connected. Fan-in triangles coordinate the timing of presynaptic inputs during ongoing activity to effectively generate postsynaptic spiking. As a result, paradoxically, fan-in triangles dominate the statistics of spike propagation even in randomly connected recurrent networks. Interplay between higher-order synaptic connectivity and the integrative properties of neurons constrains the structure of network dynamics and shapes the routing of information in neocortex. PMID:27542093

  9. Method to describe stochastic dynamics using an optimal coordinate.

    PubMed

    Krivov, Sergei V

    2013-12-01

    A general method to describe the stochastic dynamics of Markov processes is suggested. The method aims to solve three related problems: the determination of an optimal coordinate for the description of stochastic dynamics; the reconstruction of time from an ensemble of stochastic trajectories; and the decomposition of stationary stochastic dynamics into eigenmodes which do not decay exponentially with time. The problems are solved by introducing additive eigenvectors which are transformed by a stochastic matrix in a simple way - every component is translated by a constant distance. Such solutions have peculiar properties. For example, an optimal coordinate for stochastic dynamics with detailed balance is a multivalued function. An optimal coordinate for a random walk on a line corresponds to the conventional eigenvector of the one-dimensional Dirac equation. The equation for the optimal coordinate in a slowly varying potential reduces to the Hamilton-Jacobi equation for the action function. PMID:24483410

  10. Specimen coordinate automated measuring machine/fiducial automated measuring machine

    SciTech Connect

    Hedglen, Robert E.; Jacket, Howard S.; Schwartz, Allan I.

    1991-01-01

    The Specimen coordinate Automated Measuring Machine (SCAMM) and the Fiducial Automated Measuring Machine (FAMM) is a computer controlled metrology system capable of measuring length, width, and thickness, and of locating fiducial marks. SCAMM and FAMM have many similarities in their designs, and they can be converted from one to the other without taking them out of the hot cell. Both have means for: supporting a plurality of samples and a standard; controlling the movement of the samples in the +/- X and Y directions; determining the coordinates of the sample; compensating for temperature effects; and verifying the accuracy of the measurements and repeating as necessary. SCAMM and FAMM are designed to be used in hot cells.

  11. Challenges for the understanding of the dynamics of social coordination

    PubMed Central

    Lagarde, Julien

    2013-01-01

    The way people interact can be examined by looking at the way they move relative to each other. Seeking the principles behind those interactions have consequences potentially related to any type of interpersonal function, far beyond the so-called “motor” processes typically associated with the study of movements, be it perceptive, cognitive, affective, pragmatic, or epistemic. Here, we present the way the framework of coordination dynamics define and addresses the interactive actions in a dyad. We first introduce the basics of pattern formation as the roots of the theoretical approach of coordination dynamics, and then the way this framework may contribute to establish a solution to classify behaviors. Thereafter we review promising empirical results on the dynamics of interpersonal coordination, and finally discuss were to go next to decipher the way the coordination between two people and the way each individual contribute may be disentangled. PMID:24130526

  12. Minimal Coordinate Formulation of Contact Dynamics in Operational Space

    NASA Technical Reports Server (NTRS)

    Jain, Abhinandan; Crean, Cory; Ku, Calvin; Myint, Steven; vonBremen, Hubertus

    2012-01-01

    In recent years, complementarity techniques have been developed for modeling non-smooth contact and collision dynamics problems for multi-link robotic systems. Normally, in this approach, a linear complementarity problem (LCP) is set up using 6n non-minimal coordinates for a system with n links together with all the unilateral constraints and inter-link bilateral constraints on the system. In this paper, we use operational space dynamics to develop a complementarity formulation for contact and collision dynamics that uses minimal coordinates. The use of such non-redundant coordinates results in much smaller size LCP problems and the automatic enforcement of the inter-link bilateral constraints. Furthermore, we exploit operational space low-order computational algorithms to overcome some of the bottlenecks in using minimal coordinates.

  13. Multiple measurement models of articulated arm coordinate measuring machines

    NASA Astrophysics Data System (ADS)

    Zheng, Dateng; Xiao, Zhongyue; Xia, Xiang

    2015-09-01

    The existing articulated arm coordinate measuring machines(AACMM) with one measurement model are easy to cause low measurement accuracy because the whole sampling space is much bigger than the result in the unstable calibration parameters. To compensate for the deficiency of one measurement model, the multiple measurement models are built by the Denavit-Hartenberg's notation, the homemade standard rod components are used as a calibration tool and the Levenberg-Marquardt calibration algorithm is applied to solve the structural parameters in the measurement models. During the tests of multiple measurement models, the sample areas are selected in two situations. It is found that the measurement errors' sigma value(0.083 4 mm) dealt with one measurement model is nearly two times larger than that of the multiple measurement models(0.043 1 mm) in the same sample area. While in the different sample area, the measurement errors' sigma value(0.054 0 mm) dealt with the multiple measurement models is about 40% of one measurement model(0.137 3 mm). The preliminary results suggest that the measurement accuracy of AACMM dealt with multiple measurement models is superior to the accuracy of the existing machine with one measurement model. This paper proposes the multiple measurement models to improve the measurement accuracy of AACMM without increasing any hardware cost.

  14. Dynamic coordination of a self-reconfigurable manipulator system

    NASA Technical Reports Server (NTRS)

    Kim, Sungbok; Lee, Sukhan

    1991-01-01

    The authors present the dynamic coordination of a self-reconfigurable manipulator system capable of changing its mechanical structure according to given task requirements. The self-reconfiguration is achieved by reconfiguring the topology of a dual-arm system through serial, parallel, and bracing structures. Particular emphasis is placed on the dynamic coordination of two arms having three different dual-arm topologies. The authors develop the Cartesian space dynamic models of a dual-arm system of three dual-arm topologies and derive the kinematic and dynamic constraints imposed on two arms in cooperation. Dual-arm dynamic manipulabilities are defined to quantify the dynamic performance of three dual-arm topologies in terms of the efficiency of generating Cartesian accelerations. A methodology of selecting serial, parallel, and bracing structures based on dual-arm dynamic manipulabilities is provided.

  15. Bihemispheric network dynamics coordinating vocal feedback control.

    PubMed

    Kort, Naomi S; Cuesta, Pablo; Houde, John F; Nagarajan, Srikantan S

    2016-04-01

    Modulation of vocal pitch is a key speech feature that conveys important linguistic and affective information. Auditory feedback is used to monitor and maintain pitch. We examined induced neural high gamma power (HGP) (65-150 Hz) using magnetoencephalography during pitch feedback control. Participants phonated into a microphone while hearing their auditory feedback through headphones. During each phonation, a single real-time 400 ms pitch shift was applied to the auditory feedback. Participants compensated by rapidly changing their pitch to oppose the pitch shifts. This behavioral change required coordination of the neural speech motor control network, including integration of auditory and somatosensory feedback to initiate change in motor plans. We found increases in HGP across both hemispheres within 200 ms of pitch shifts, covering left sensory and right premotor, parietal, temporal, and frontal regions, involved in sensory detection and processing of the pitch shift. Later responses to pitch shifts (200-300 ms) were right dominant, in parietal, frontal, and temporal regions. Timing of activity in these regions indicates their role in coordinating motor change and detecting and processing of the sensory consequences of this change. Subtracting out cortical responses during passive listening to recordings of the phonations isolated HGP increases specific to speech production, highlighting right parietal and premotor cortex, and left posterior temporal cortex involvement in the motor response. Correlation of HGP with behavioral compensation demonstrated right frontal region involvement in modulating participant's compensatory response. This study highlights the bihemispheric sensorimotor cortical network involvement in auditory feedback-based control of vocal pitch. PMID:26917046

  16. Virtual Partner Interaction (VPI): exploring novel behaviors via coordination dynamics.

    PubMed

    Kelso, J A Scott; de Guzman, Gonzalo C; Reveley, Colin; Tognoli, Emmanuelle

    2009-01-01

    Inspired by the dynamic clamp of cellular neuroscience, this paper introduces VPI -- Virtual Partner Interaction -- a coupled dynamical system for studying real time interaction between a human and a machine. In this proof of concept study, human subjects coordinate hand movements with a virtual partner, an avatar of a hand whose movements are driven by a computerized version of the Haken-Kelso-Bunz (HKB) equations that have been shown to govern basic forms of human coordination. As a surrogate system for human social coordination, VPI allows one to examine regions of the parameter space not typically explored during live interactions. A number of novel behaviors never previously observed are uncovered and accounted for. Having its basis in an empirically derived theory of human coordination, VPI offers a principled approach to human-machine interaction and opens up new ways to understand how humans interact with human-like machines including identification of underlying neural mechanisms. PMID:19492044

  17. Virtual Partner Interaction (VPI): Exploring Novel Behaviors via Coordination Dynamics

    PubMed Central

    Kelso, J. A. Scott; de Guzman, Gonzalo C.; Reveley, Colin; Tognoli, Emmanuelle

    2009-01-01

    Inspired by the dynamic clamp of cellular neuroscience, this paper introduces VPI—Virtual Partner Interaction—a coupled dynamical system for studying real time interaction between a human and a machine. In this proof of concept study, human subjects coordinate hand movements with a virtual partner, an avatar of a hand whose movements are driven by a computerized version of the Haken-Kelso-Bunz (HKB) equations that have been shown to govern basic forms of human coordination. As a surrogate system for human social coordination, VPI allows one to examine regions of the parameter space not typically explored during live interactions. A number of novel behaviors never previously observed are uncovered and accounted for. Having its basis in an empirically derived theory of human coordination, VPI offers a principled approach to human-machine interaction and opens up new ways to understand how humans interact with human-like machines including identification of underlying neural mechanisms. PMID:19492044

  18. Large-deformation modal coordinates for nonrigid vehicle dynamics

    NASA Technical Reports Server (NTRS)

    Likins, P. W.; Fleischer, G. E.

    1972-01-01

    The derivation of minimum-dimension sets of discrete-coordinate and hybrid-coordinate equations of motion of a system consisting of an arbitrary number of hinge-connected rigid bodies assembled in tree topology is presented. These equations are useful for the simulation of dynamical systems that can be idealized as tree-like arrangements of substructures, with each substructure consisting of either a rigid body or a collection of elastically interconnected rigid bodies restricted to small relative rotations at each connection. Thus, some of the substructures represent elastic bodies subjected to small strains or local deformations, but possibly large gross deformations, in the hybrid formulation, distributed coordinates referred to herein as large-deformation modal coordinates, are used for the deformations of these substructures. The equations are in a form suitable for incorporation into one or more computer programs to be used as multipurpose tools in the simulation of spacecraft and other complex electromechanical systems.

  19. Coupling Dynamics Interlip Coordination in Lower Lip Load Compensation

    ERIC Educational Resources Information Center

    van Lieshout, Pascal; Neufeld, Chris

    2014-01-01

    Purpose: To study the effects of lower lip loading on lower and upper lip movements and their coordination to test predictions on coupling dynamics derived from studies in limb control. Method: Movement data were acquired using electromagnetic midsagittal articulography under 4 conditions: (a) without restrictions, serving as a baseline; (b) with…

  20. The Teaching of Polar Coordinates with Dynamic Mathematics Software

    ERIC Educational Resources Information Center

    Zengin, Yilmaz; Tatar, Enver

    2015-01-01

    The purpose of this study was to determine the effects of dynamic mathematics software on the achievement of pre-service mathematics teachers in the topic of polar coordinates and to solicit their opinions about computer-assisted instruction. The study was conducted for 11 weeks with 33 pre-service teachers in the Department of Mathematics…

  1. Functional coordination of muscles underlying changes in behavioural dynamics.

    PubMed

    Vernooij, Carlijn A; Rao, Guillaume; Perdikis, Dionysios; Huys, Raoul; Jirsa, Viktor K; Temprado, Jean-Jacques

    2016-01-01

    The dynamical systems approach addresses Bernstein's degrees of freedom problem by assuming that the neuro-musculo-skeletal system transiently assembles and dismantles its components into functional units (or synergies) to meet task demands. Strikingly, little is known from a dynamical point of view about the functioning of the muscular sub-system in this process. To investigate the interaction between the dynamical organisation at muscular and behavioural levels, we searched for specific signatures of a phase transition in muscular coordination when a transition is displayed at the behavioural level. Our results provide evidence that, during Fitts' task when behaviour switches to a different dynamical regime, muscular activation displays typical signatures of a phase transition; a reorganisation in muscular coordination patterns accompanied by a peak in the variability of muscle activation. This suggests that consistent changes occur in coordination processes across the different levels of description (i.e., behaviour and muscles). Specifically, in Fitts' task, target size acts as a control parameter that induces a destabilisation and a reorganisation of coordination patterns at different levels of the neuro-musculo-skeletal system. PMID:27282349

  2. Functional coordination of muscles underlying changes in behavioural dynamics

    PubMed Central

    Vernooij, Carlijn A.; Rao, Guillaume; Perdikis, Dionysios; Huys, Raoul; Jirsa, Viktor K.; Temprado, Jean-Jacques

    2016-01-01

    The dynamical systems approach addresses Bernstein’s degrees of freedom problem by assuming that the neuro-musculo-skeletal system transiently assembles and dismantles its components into functional units (or synergies) to meet task demands. Strikingly, little is known from a dynamical point of view about the functioning of the muscular sub-system in this process. To investigate the interaction between the dynamical organisation at muscular and behavioural levels, we searched for specific signatures of a phase transition in muscular coordination when a transition is displayed at the behavioural level. Our results provide evidence that, during Fitts’ task when behaviour switches to a different dynamical regime, muscular activation displays typical signatures of a phase transition; a reorganisation in muscular coordination patterns accompanied by a peak in the variability of muscle activation. This suggests that consistent changes occur in coordination processes across the different levels of description (i.e., behaviour and muscles). Specifically, in Fitts’ task, target size acts as a control parameter that induces a destabilisation and a reorganisation of coordination patterns at different levels of the neuro-musculo-skeletal system. PMID:27282349

  3. Building Blocks for Measuring Care Coordination with Claims Data

    PubMed Central

    DuGoff, Eva H.

    2014-01-01

    Abstract Tools to measure care coordination are needed to evaluate federal, state, and private sector efforts encouraging coordination to improve health outcomes and contain costs. Administrative data are a rich source of data for studying the use of medical services, thus allowing for measurement of patient level, provider level, and system measures of care coordination. Based on a review the literature and input from an expert panel, this article describes 4 key components—building blocks—of care coordination and corresponding measures. These building blocks should have utility across clinical conditions. They may be used to test hypotheses about the impact of coordinated care on medication utilization, adherence to medications, and clinical outcomes. (Population Health Management 2014;17:247–252) PMID:24606582

  4. Building blocks for measuring care coordination with claims data.

    PubMed

    Segal, Jodi B; DuGoff, Eva H

    2014-08-01

    Tools to measure care coordination are needed to evaluate federal, state, and private sector efforts encouraging coordination to improve health outcomes and contain costs. Administrative data are a rich source of data for studying the use of medical services, thus allowing for measurement of patient level, provider level, and system measures of care coordination. Based on a review the literature and input from an expert panel, this article describes 4 key components-building blocks-of care coordination and corresponding measures. These building blocks should have utility across clinical conditions. They may be used to test hypotheses about the impact of coordinated care on medication utilization, adherence to medications, and clinical outcomes. PMID:24606582

  5. Rowing Crew Coordination Dynamics at Increasing Stroke Rates

    PubMed Central

    2015-01-01

    In rowing, perfect synchronisation is important for optimal performance of a crew. Remarkably, a recent study on ergometers demonstrated that antiphase crew coordination might be mechanically more efficient by reducing the power lost to within-cycle velocity fluctuations of the boat. However, coupled oscillator dynamics predict the stability of the coordination to decrease with increasing stroke rate, which in case of antiphase may eventually yield breakdowns to in-phase. Therefore, this study examined the effects of increasing stroke rate on in- and antiphase crew coordination in rowing dyads. Eleven experienced dyads rowed on two mechanically coupled ergometers on slides, which allowed the ergometer system to move back and forth as one ‘boat’. The dyads performed a ramp trial in both in- and antiphase pattern, in which stroke rates gradually increased from 30 strokes per minute (spm) to as fast as possible in steps of 2 spm. Kinematics of rowers, handles and ergometers were captured. Two dyads showed a breakdown of antiphase into in-phase coordination at the first stroke rate of the ramp trial. The other nine dyads reached between 34–42 spm in antiphase but achieved higher rates in in-phase. As expected, the coordinative accuracy in antiphase was worse than in in-phase crew coordination, while, somewhat surprisingly, the coordinative variability did not differ between the patterns. Whereas crew coordination did not substantially deteriorate with increasing stroke rate, stroke rate did affect the velocity fluctuations of the ergometers: fluctuations were clearly larger in the in-phase pattern than in the antiphase pattern, and this difference significantly increased with stroke rate. Together, these results suggest that although antiphase rowing is less stable (i.e., less resistant to perturbation), potential on-water benefits of antiphase over in-phase rowing may actually increase with stroke rate. PMID:26185987

  6. Automatic ball bar for a coordinate measuring machine

    DOEpatents

    Jostlein, H.

    1997-07-15

    An automatic ball bar for a coordinate measuring machine determines the accuracy of a coordinate measuring machine having at least one servo drive. The apparatus comprises a first and second gauge ball connected by a telescoping rigid member. The rigid member includes a switch such that inward radial movement of the second gauge ball relative to the first gauge ball causes activation of the switch. The first gauge ball is secured in a first magnetic socket assembly in order to maintain the first gauge ball at a fixed location with respect to the coordinate measuring machine. A second magnetic socket assembly secures the second gauge ball to the arm or probe holder of the coordinate measuring machine. The second gauge ball is then directed by the coordinate measuring machine to move radially inward from a point just beyond the length of the ball bar until the switch is activated. Upon switch activation, the position of the coordinate measuring machine is determined and compared to known ball bar length such that the accuracy of the coordinate measuring machine can be determined. 5 figs.

  7. Automatic ball bar for a coordinate measuring machine

    DOEpatents

    Jostlein, Hans

    1997-01-01

    An automatic ball bar for a coordinate measuring machine determines the accuracy of a coordinate measuring machine having at least one servo drive. The apparatus comprises a first and second gauge ball connected by a telescoping rigid member. The rigid member includes a switch such that inward radial movement of the second gauge ball relative to the first gauge ball causes activation of the switch. The first gauge ball is secured in a first magnetic socket assembly in order to maintain the first gauge ball at a fixed location with respect to the coordinate measuring machine. A second magnetic socket assembly secures the second gauge ball to the arm or probe holder of the coordinate measuring machine. The second gauge ball is then directed by the coordinate measuring machine to move radially inward from a point just beyond the length of the ball bar until the switch is activated. Upon switch activation, the position of the coordinate measuring machine is determined and compared to known ball bar length such that the accuracy of the coordinate measuring machine can be determined.

  8. Measurement system for 3-D foot coordinates and parameters

    NASA Astrophysics Data System (ADS)

    Liu, Guozhong; Li, Yunhui; Wang, Boxiong; Shi, Hui; Luo, Xiuzhi

    2008-12-01

    The 3-D foot-shape measurement system based on laser-line-scanning principle and the model of the measurement system were presented. Errors caused by nonlinearity of CCD cameras and caused by installation can be eliminated by using the global calibration method for CCD cameras, which based on nonlinear coordinate mapping function and the optimized method. A local foot coordinate system is defined with the Pternion and the Acropodion extracted from the boundaries of foot projections. The characteristic points can thus be located and foot parameters be extracted automatically by the local foot coordinate system and the related sections. Foot measurements for about 200 participants were conducted and the measurement results for male and female participants were presented. 3-D foot coordinates and parameters measurement makes it possible to realize custom-made shoe-making and shows great prosperity in shoe design, foot orthopaedic treatment, shoe size standardization, and establishment of a feet database for consumers.

  9. Advanced techniques for constrained internal coordinate molecular dynamics.

    PubMed

    Wagner, Jeffrey R; Balaraman, Gouthaman S; Niesen, Michiel J M; Larsen, Adrien B; Jain, Abhinandan; Vaidehi, Nagarajan

    2013-04-30

    Internal coordinate molecular dynamics (ICMD) methods provide a more natural description of a protein by using bond, angle, and torsional coordinates instead of a Cartesian coordinate representation. Freezing high-frequency bonds and angles in the ICMD model gives rise to constrained ICMD (CICMD) models. There are several theoretical aspects that need to be developed to make the CICMD method robust and widely usable. In this article, we have designed a new framework for (1) initializing velocities for nonindependent CICMD coordinates, (2) efficient computation of center of mass velocity during CICMD simulations, (3) using advanced integrators such as Runge-Kutta, Lobatto, and adaptive CVODE for CICMD simulations, and (4) cancelling out the "flying ice cube effect" that sometimes arises in Nosé-Hoover dynamics. The Generalized Newton-Euler Inverse Mass Operator (GNEIMO) method is an implementation of a CICMD method that we have developed to study protein dynamics. GNEIMO allows for a hierarchy of coarse-grained simulation models based on the ability to rigidly constrain any group of atoms. In this article, we perform tests on the Lobatto and Runge-Kutta integrators to determine optimal simulation parameters. We also implement an adaptive coarse-graining tool using the GNEIMO Python interface. This tool enables the secondary structure-guided "freezing and thawing" of degrees of freedom in the molecule on the fly during molecular dynamics simulations and is shown to fold four proteins to their native topologies. With these advancements, we envision the use of the GNEIMO method in protein structure prediction, structure refinement, and in studying domain motion. PMID:23345138

  10. Coordination dynamics of (a)symmetrically loaded gait.

    PubMed

    Russell, Daniel M; Haworth, Joshua L; Martinez-Garza, Cesar

    2016-03-01

    Asymmetries in the resonant frequency of limbs/effectors lead to changes in coordination dynamics, including deviations in relative phase at ϕ = 0 or π rad and reduced stability. These effects have been successfully modeled by the extended Haken-Kelso-Bunz (HKB) coupled oscillator model (Kelso et al. in Attention and performance XIII. Erlbaum, Hillsdale, pp 139-169, 1990), and supported in laboratory tasks of rhythmic limb motions. Efforts to apply the HKB model to walking have supported the predicted deviations in phase, but not the expected decreases in coordination stability. The lack of stability effects arising from asymmetries may be due to the stabilizing influence of a treadmill or may be obscured by the balance requirements and ground impacts in gait. This study examined these possibilities by investigating walking overground with ankle weights of 3 or 6 kg to create asymmetries between the legs, as well as symmetrical loads. Participants walked without a metronome and separately with a metronome to control speed and cadence. Coordination dynamics between the legs were quantified through mean and standard deviation (SD) of ϕ, while individual leg local dynamic stability was calculated as maximum Lyapunov exponent (λ (MAX)). Irrespective of the condition, asymmetrical loads led to deviations in phase from antiphase with the loaded leg lagging behind the other, and both SDϕ and λ (MAX) increased (i.e., stability decreased). Symmetrical loads had no effect on phase deviations, but decreased stability. Overall, these findings indicate that the HKB model captures coordination dynamics in walking, but also highlights limitations in modeling the influence of loads on an individual limb. PMID:26661338

  11. Coordination of Cellular Dynamics Contributes to Tooth Epithelium Deformations.

    PubMed

    Morita, Ritsuko; Kihira, Miho; Nakatsu, Yousuke; Nomoto, Yohei; Ogawa, Miho; Ohashi, Kazumasa; Mizuno, Kensaku; Tachikawa, Tetsuhiko; Ishimoto, Yukitaka; Morishita, Yoshihiro; Tsuji, Takashi

    2016-01-01

    The morphologies of ectodermal organs are shaped by appropriate combinations of several deformation modes, such as invagination and anisotropic tissue elongation. However, how multicellular dynamics are coordinated during deformation processes remains to be elucidated. Here, we developed a four-dimensional (4D) analysis system for tracking cell movement and division at a single-cell resolution in developing tooth epithelium. The expression patterns of a Fucci probe clarified the region- and stage-specific cell cycle patterns within the tooth germ, which were in good agreement with the pattern of the volume growth rate estimated from tissue-level deformation analysis. Cellular motility was higher in the regions with higher growth rates, while the mitotic orientation was significantly biased along the direction of tissue elongation in the epithelium. Further, these spatio-temporal patterns of cellular dynamics and tissue-level deformation were highly correlated with that of the activity of cofilin, which is an actin depolymerization factor, suggesting that the coordination of cellular dynamics via actin remodeling plays an important role in tooth epithelial morphogenesis. Our system enhances the understanding of how cellular behaviors are coordinated during ectodermal organogenesis, which cannot be observed from histological analyses. PMID:27588418

  12. Phosphoinositides: Important lipids in the coordination of cell dynamics.

    PubMed

    Viaud, Julien; Mansour, Rana; Antkowiak, Adrien; Mujalli, Abdulrahman; Valet, Colin; Chicanne, Gaëtan; Xuereb, Jean-Marie; Terrisse, Anne-Dominique; Séverin, Sonia; Gratacap, Marie-Pierre; Gaits-Iacovoni, Frédérique; Payrastre, Bernard

    2016-06-01

    By interacting specifically with proteins, phosphoinositides organize the spatiotemporal formation of protein complexes involved in the control of intracellular signaling, vesicular trafficking and cytoskeleton dynamics. A set of specific kinases and phosphatases ensures the production, degradation and inter-conversion of phosphoinositides to achieve a high level of precision in the regulation of cellular dynamics coordinated by these lipids. The direct involvement of these enzymes in cancer, genetic or infectious diseases, and the recent arrival of inhibitors targeting specific phosphoinositide kinases in clinic, emphasize the importance of these lipids and their metabolism in the biomedical field. PMID:26391221

  13. Coordinate Measuring Machine Pit Artifact Inspection Procedure

    SciTech Connect

    Montano, Joshua D.

    2012-07-31

    The goal of this document is to outline a procedure for dimensional measurement of Los Alamos National Laboratory's CMM Pit Artifact. This procedure will be used by the Manufacturing Practice's Inspection Technology Subgroup of the Interagency Manufacturing Operations Group and Joint Operations Weapon Operations Group (IMOG/JOWOG 39) round robin participants. The intent is to assess the state of industry within the Nuclear Weapons Complex for measurements made on this type of part and find which current measurement strategies and techniques produce the best results.

  14. Magnet Fiducialization with Coordinate Measuring Machines

    SciTech Connect

    Friedsam, H.; Oren, W.; Pietryka, M.; /SLAC

    2005-08-12

    One of the fundamental alignment problems encountered when building a particle accelerator is the transfer of a component's magnetic centerline position to external fiducials. This operation, dubbed fiducialization, is critical because it can contribute significantly to the alignment error budget. The fiducialization process requires two measurements: (1) from magnetic centerline to mechanical centerline, and (2) from mechanical centerline to external fiducials. This paper will focus on methods for observing the second measurement. Two Stanford Linear Collider (SLC) examples are presented. The object of magnet fiducialization is to relate the magnet-defined beamline position to exterior reference surfaces. To be useful for later component alignment, this relationship must be established in a manner consistent with overall positioning tolerances. The error budget for the SLC's {+-} 100 {micro}m component to component alignment tolerance is as follows: magnetic centerline to mechanical centerline--{sigma} = {+-}30 {micro}m; mechanical centerline to fiducial marks--{sigma} = {+-}50 {micro}m; and fiducial marks to adjacent components--{sigma} = {+-}80 {micro}m; the TOTAL {sigma} = {+-}100 {micro}m. The offset between the mechanical and magnetic centerlines of well-known magnets is generally smaller than the {+-}30 {micro}m measurement tolerance. It is commonly assumed to be zero without measurement. When this tiny value must be measured, extreme care is necessary to avoid obscuring the offset with measurement tool registration errors. In contrast, the mechanical centerline to fiducial measurement must be performed on every magnet. The 50 {micro}m tolerance for this operation is only slightly larger and pushes conventional surveying technology to its limit.

  15. Advanced Techniques for Constrained Internal Coordinate Molecular Dynamics

    PubMed Central

    Wagner, Jeffrey R.; Balaraman, Gouthaman S.; Niesen, Michiel J. M.; Larsen, Adrien B.; Jain, Abhinandan; Vaidehi, Nagarajan

    2013-01-01

    Internal coordinate molecular dynamics (ICMD) methods provide a more natural description of a protein by using bond, angle and torsional coordinates instead of a Cartesian coordinate representation. Freezing high frequency bonds and angles in the ICMD model gives rise to constrained ICMD (CICMD) models. There are several theoretical aspects that need to be developed in order to make the CICMD method robust and widely usable. In this paper we have designed a new framework for 1) initializing velocities for non-independent CICMD coordinates, 2) efficient computation of center of mass velocity during CICMD simulations, 3) using advanced integrators such as Runge-Kutta, Lobatto and adaptive CVODE for CICMD simulations, and 4) cancelling out the “flying ice cube effect” that sometimes arises in Nosé-Hoover dynamics. The Generalized Newton-Euler Inverse Mass Operator (GNEIMO) method is an implementation of a CICMD method that we have developed to study protein dynamics. GNEIMO allows for a hierarchy of coarse-grained simulation models based on the ability to rigidly constrain any group of atoms. In this paper, we perform tests on the Lobatto and Runge-Kutta integrators to determine optimal simulation parameters. We also implement an adaptive coarse graining tool using the GNEIMO Python interface. This tool enables the secondary structure-guided “freezing and thawing” of degrees of freedom in the molecule on the fly during MD simulations, and is shown to fold four proteins to their native topologies. With these advancements we envision the use of the GNEIMO method in protein structure prediction, structure refinement, and in studying domain motion. PMID:23345138

  16. The teaching of polar coordinates with dynamic mathematics software

    NASA Astrophysics Data System (ADS)

    Zengin, Yılmaz; Tatar, Enver

    2015-01-01

    The purpose of this study was to determine the effects of dynamic mathematics software on the achievement of pre-service mathematics teachers in the topic of polar coordinates and to solicit their opinions about computer-assisted instruction. The study was conducted for 11 weeks with 33 pre-service teachers in the Department of Mathematics Education Program of a state university in Turkey. Data collection tools comprised a knowledge test of polar coordinates and administration of a semi-structured interview form developed by the researchers who conducted the study using an embedded design as part of a mixed-method research. The results of data analysis showed that the computer-assisted instruction method in which dynamic mathematics software was used positively contributed to the success of pre-service teachers in understanding the subject of polar coordinates. Furthermore, it was found that pre-service teachers supported the use of this method in lessons as it provides visualization, increases retention, concretization of abstract mathematical structures, better understanding and learning, and creates an interesting and interactive learning environment.

  17. Interpersonal coordination and ball dynamics in futsal (indoor football).

    PubMed

    Travassos, B; Araújo, D; Vilar, L; McGarry, T

    2011-12-01

    Here, we report an investigation of the patterned movement behavior of players for a specific sub-phase of the game of futsal, namely when the goalkeeper for the attacking team is substituted with an extra outfield player. The movement trajectories of the ball and players were recorded in both lateral and longitudinal directions and investigated using relative phase analysis. Some differences in phase relations between different playing dyads were noted, indicating specificity of phase attractions, or otherwise, for certain players. In general terms, the defenders demonstrated strong in-phase attractions with the ball and with each other, whereas weaker phase attractions, indicated by increased relative phase variability, were observed for the attackers and ball, as well as between attackers themselves. These results demonstrate different coordination dynamics for the defending and attacking dyads, from which we interpret evidence for different playing sub-systems consistent with different team objectives linked together in an overarching game structure. In keeping with dynamical systems theory for complex systems, we view this sub-phase of futsal as being characterized by coordinated behavior patterns that emerge as a result of self-organizing processes. These dynamic patterns are generated within functional constraints, with players and teams exerting mutual influence on each other. PMID:21683464

  18. Inter-segmental Postural Coordination Measures Differentiate Athletes with ACL Reconstruction from Uninjured Athletes

    PubMed Central

    Kiefer, Adam W.; Ford, Kevin R.; Paterno, Mark V.; Schmitt, Laura C.; Myer, Gregory D.; Riley, Michael A.; Shockley, Kevin; Hewett, Timothy E.

    2012-01-01

    Athletes who sustain non-contact anterior cruciate ligament (ACL) injuries and undergo surgical reconstruction exhibit deficits in sensorimotor control, which often impairs lower-limb movement coordination. The purpose of this experiment was to measure the influence of sensorimotor deficits on the ankle-hip coordination of a postural coordination task in athletes following ACL reconstruction. Twenty-two female athletes who were cleared to return to sports participation following ACL reconstruction and 22 uninjured female athletes performed a unilateral dynamic postural rhythmic coordination task at two movement frequencies (0.2 and 0.7 Hz). Athletes with ACL-reconstruction exhibited greater ankle-hip relative phase variability and reduced regularity of coupling than uninjured athletes, especially during the 0.2 Hz condition. The results of this study show altered lower extremity coordination patterns in athletes following ACL reconstruction and return to sports participation. The results also indicate that dynamical coordination measures may provide objective measures of sensorimotor deficits following ACL reconstruction and can potentially guide rehabilitation interventions following reconstruction. PMID:23219784

  19. Study on portable optical 3D coordinate measuring system

    NASA Astrophysics Data System (ADS)

    Ren, Tongqun; Zhu, Jigui; Guo, Yinbiao

    2009-05-01

    A portable optical 3D coordinate measuring system based on digital Close Range Photogrammetry (CRP) technology and binocular stereo vision theory is researched. Three ultra-red LED with high stability is set on a hand-hold target to provide measuring feature and establish target coordinate system. Ray intersection based field directional calibrating is done for the intersectant binocular measurement system composed of two cameras by a reference ruler. The hand-hold target controlled by Bluetooth wireless communication is free moved to implement contact measurement. The position of ceramic contact ball is pre-calibrated accurately. The coordinates of target feature points are obtained by binocular stereo vision model from the stereo images pair taken by cameras. Combining radius compensation for contact ball and residual error correction, object point can be resolved by transfer of axes using target coordinate system as intermediary. This system is suitable for on-field large-scale measurement because of its excellent portability, high precision, wide measuring volume, great adaptability and satisfying automatization. It is tested that the measuring precision is near to +/-0.1mm/m.

  20. Unified Selenocentric Reference Coordinates Net in the Dynamic System

    NASA Astrophysics Data System (ADS)

    Nefedyev, Yuri; Petrova, Natalia; Varaksina, Natalia

    In this report the task of the making selenocentric inertial reference net is solved. The purpose is making summary reference net by expansion KSC-1162 selenodetic system using 12 cosmic and ground selenodesic catalogues. The prospective analysis of this net was performed. These selenocentric reference catalogue covers full visible and a part of far lunar sides. Modern cosmic technologies need the accurate coordinate - temporal support including reference frame realization, inertial and dynamic system orientation and studying dynamic and geometry celestial bodies. That refers to dynamic and geometric selenocentric lunar parameters. The catalogue based on mission “Apollo” and reference nets of the west lunar hemisphere made by missions “Zond 5”, ”Zond 8” cover small part of the Moon surface. Three ALSEP stations were used to transform “Apollo” topographic coordinates. Transformation mean-square errors are less than 80 meters and measurement’s errors are about 60 meters. On this account positions inaccuracy near and between ALSEP stations are less 150 meters. The offset from place of the location ALSEP enlarges the supposed mistake is more than 300 m and this is a major part of the lunar surface. In solving the problem of high-precision condensation and expansion of fundamental selenocentric net KSC-1162 on the visible side of the Moon and lunar far side were obtained following new results: a) the analysis and investigation of the accuracy of basic net contained in ULCN were carried out; b) the decryption of common objects for coordinate systems which are being explored was executed; c) the extension of the mathematical content package TSC was carried out; d) the development of TSC as an expert system of universal transformation planet's coordinates was carried out; e) the possibility of applying the ARM-approach to the problem TC on common objects, which allows to find optimal parameter estimation and model structure of TC was confirmed; f) the

  1. Measuring a hidden coordinate: Rate-exchange kinetics from 3D correlation functions

    NASA Astrophysics Data System (ADS)

    Berg, Mark A.; Darvin, Jason R.

    2016-08-01

    Nonexponential kinetics imply the existence of at least one slow variable other than the observable, that is, the system has a "hidden" coordinate. We develop a simple, but general, model that allows multidimensional correlation functions to be calculated for these systems. Homogeneous and heterogeneous mechanisms are both included, and slow exchange of the rates is allowed. This model shows that 2D and 3D correlation functions of the observable measure the distribution and kinetics of the hidden coordinate controlling the rate exchange. Both the mean exchange time and the shape of the exchange relaxation are measurable. However, complications arise because higher correlation functions are sums of multiple "pathways," each of which measures different dynamics. Only one 3D pathway involves exchange dynamics. Care must be used to extract exchange dynamics without contamination from other processes.

  2. Combined non-contact coordinate measurement system and calibration method

    NASA Astrophysics Data System (ADS)

    Fan, Yiyan; Zhao, Bin

    2015-07-01

    A combined non-contact measurement system comprising attitude angle sensor, angle encoder, laser rangefinder, and total station is adopted to measure the spatial coordinate of the hidden zones in large-scale space. The laser from the total station is aimed at the optical system of the attitude angle sensor to obtain the spatial coordinate and the spatial attitude angles. Then, the angle encoder driven by a stepping motor is rotated to drive the laser rangefinder to direct at the measured point. This approach is used to obtain the distance from the rangefinder to the measured point and the angle of the angle encoder. Finally, the spatial coordinates of the measured point can be calculated by using these measured parameters. For the measurement system, we propose a weighted least squares (WLS) calibration method, in which weights are determined for the angular distribution density. Experimental results show that the measurement system could expand the scale and achieve reliable precision during combined measurement and the measurement error of the weighted least squares method is less than that of the ordinary least square (OLS) method.

  3. The delimitation of the workspace accuracy in coordinate measuring technique.

    PubMed

    Swornowski, Pawel

    2011-01-01

    Dimensional measurements based on coordinate metrology are widely used for product verification, process control and dimensional faults root causes diagnostics of various manufacturing processes. In this study, the results of the measuring surface scanning of coordinate measuring machine with the prototype of optoelectronic device have been presented. The presented device is able to determine actual (real) inaccuracy of the CMM in two axes (X, Y). The prototype scanning device is installed in the measuring probe place. The method makes possible scanning with the established accuracy (max. 0.1 µm). A short description of the new method and the device is added, and some initial results are discussed. The results concern the inaccuracy of the CMMs example measuring area. PMID:21370236

  4. Quadratic elongation: A quantitative measure of distortion in coordination polyhedra

    USGS Publications Warehouse

    Robinson, Kelly F.; Gibbs, G.V.; Ribbe, P.H.

    1971-01-01

    Quadratic elongation and the variance of bond angles are linearly correlated for distorted octahedral and tetrahedral coordination complexes, both of which show variations in bond length and bond angle. The quadratic elonga tion is dimensionless, giving a quantitative measure of polyhedral distortion which is independent of the effective size of the polyhedron.

  5. Modeling river plume dynamics with the HYbrid Coordinate Ocean Model

    NASA Astrophysics Data System (ADS)

    Schiller, Rafael V.; Kourafalou, Vassiliki H.

    The dynamics of large-scale river plumes are investigated in idealized numerical experiments using the HYbrid Coordinate Ocean Model (HYCOM). The focus of this study is to address how the development and structure of a buoyant plume are affected by the outflow properties, as impacted by processes within the estuary and at the point of discharge to the coastal basin. Changes in the outflow properties involved vertical and horizontal redistribution of the river inflow and enhanced vertical mixing inside an idealized estuary. The development of the buoyant plume was evaluated in a rectangular, f-plane basin with flat and sloping bottom conditions and in the absence of other external forcing. The general behavior of a mid-latitude river plume was reproduced, with the development of a surface anticyclonic bulge off the estuary mouth and a surface along-shore coastal current which flows in the direction of Kelvin wave propagation ("downstream"); the momentum balance was predominantly geostrophic. Conditions within the estuary and the outflow properties at the river mouth (where observed profiles may be available) greatly impacted the fate of riverine waters. In flat bottom conditions, larger mixing at the freshwater source enhanced the estuarine gravitational circulation, promoting larger upward entrainment and stronger outflow velocities. Although the overall geostrophic balance was maintained, estuarine mixing led to an asymmetry of the currents reaching the river mouth and to a sharp anticyclonic veering within the estuary, resulting in reduced upstream flow and enhanced downstream coastal current. These patterns were altered when the plumes evolved in the presence of a bottom slope. The anticyclonic veering of the buoyant outflow was suppressed, the offshore intrusion decreased and the recirculating bulge was displaced upstream. The sloping bottom impacts were accompanied by enhanced transport and increased downstream extent of the coastal current in most cases. No

  6. Measurement error analysis of three dimensional coordinates of tomatoes acquired using the binocular stereo vision

    NASA Astrophysics Data System (ADS)

    Xiang, Rong

    2014-09-01

    This study analyzes the measurement errors of three dimensional coordinates of binocular stereo vision for tomatoes based on three stereo matching methods, centroid-based matching, area-based matching, and combination matching to improve the localization accuracy of the binocular stereo vision system of tomato harvesting robots. Centroid-based matching was realized through the matching of the feature points of centroids of tomato regions. Area-based matching was realized based on the gray similarity between two neighborhoods of two pixels to be matched in stereo images. Combination matching was realized using the rough disparity acquired through centroid-based matching as the center of the dynamic disparity range which was used in area-based matching. After stereo matching, three dimensional coordinates of tomatoes were acquired using the triangle range finding principle. Test results based on 225 stereo images captured at the distances from 300 to 1000 mm of 3 tomatoes showed that the measurement errors of x coordinates were small, and can meet the need of harvesting robots. However, the measurement biases of y coordinates and depth values were large, and the measurement variation of depth values was also large. Therefore, the measurement biases of y coordinates and depth values, and the measurement variation of depth values should be corrected in the future researches.

  7. The modeling of portable 3D vision coordinate measuring system

    NASA Astrophysics Data System (ADS)

    Liu, Shugui; Huang, Fengshan; Peng, Kai

    2005-02-01

    The portable three-dimensional vision coordinate measuring system, which consists of a light pen, a CCD camera and a laptop computer, can be widely applied in most coordinate measuring fields especially on the industrial spots. On the light pen there are at least three point-shaped light sources (LEDs) acting as the measured control characteristic points and a touch trigger probe with a spherical stylus which is used to contact the point to be measured. The most important character of this system is that three light sources and the probe stylus are aligned in one line with known positions. In building and studying this measuring system, how to construct the system"s mathematical model is the most key problem called perspective of three-collinear-points problem, which is a particular case of perspective of three-points problem (P3P). On the basis of P3P and spatial analytical geometry theory, the system"s mathematical model is established in this paper. What"s more, it is verified that perspective of three-collinear-points problem has a unique solution. And the analytical equations of the measured point"s coordinates are derived by using the system"s mathematical model and the restrict condition that three light sources and the probe stylus are aligned in one line. Finally, the effectiveness of the mathematical model is confirmed by experiments.

  8. Coordinated scheduling for dynamic real-time systems

    NASA Technical Reports Server (NTRS)

    Natarajan, Swaminathan; Zhao, Wei

    1994-01-01

    In this project, we addressed issues in coordinated scheduling for dynamic real-time systems. In particular, we concentrated on design and implementation of a new distributed real-time system called R-Shell. The design objective of R-Shell is to provide computing support for space programs that have large, complex, fault-tolerant distributed real-time applications. In R-shell, the approach is based on the concept of scheduling agents, which reside in the application run-time environment, and are customized to provide just those resource management functions which are needed by the specific application. With this approach, we avoid the need for a sophisticated OS which provides a variety of generalized functionality, while still not burdening application programmers with heavy responsibility for resource management. In this report, we discuss the R-Shell approach, summarize the achievement of the project, and describe a preliminary prototype of R-Shell system.

  9. Articulated Arm Coordinate Measuring Machine Calibration by Laser Tracker Multilateration

    PubMed Central

    Majarena, Ana C.; Brau, Agustín; Velázquez, Jesús

    2014-01-01

    A new procedure for the calibration of an articulated arm coordinate measuring machine (AACMM) is presented in this paper. First, a self-calibration algorithm of four laser trackers (LTs) is developed. The spatial localization of a retroreflector target, placed in different positions within the workspace, is determined by means of a geometric multilateration system constructed from the four LTs. Next, a nonlinear optimization algorithm for the identification procedure of the AACMM is explained. An objective function based on Euclidean distances and standard deviations is developed. This function is obtained from the captured nominal data (given by the LTs used as a gauge instrument) and the data obtained by the AACMM and compares the measured and calculated coordinates of the target to obtain the identified model parameters that minimize this difference. Finally, results show that the procedure presented, using the measurements of the LTs as a gauge instrument, is very effective by improving the AACMM precision. PMID:24688418

  10. Articulated arm coordinate measuring machine calibration by laser tracker multilateration.

    PubMed

    Santolaria, Jorge; Majarena, Ana C; Samper, David; Brau, Agustín; Velázquez, Jesús

    2014-01-01

    A new procedure for the calibration of an articulated arm coordinate measuring machine (AACMM) is presented in this paper. First, a self-calibration algorithm of four laser trackers (LTs) is developed. The spatial localization of a retroreflector target, placed in different positions within the workspace, is determined by means of a geometric multilateration system constructed from the four LTs. Next, a nonlinear optimization algorithm for the identification procedure of the AACMM is explained. An objective function based on Euclidean distances and standard deviations is developed. This function is obtained from the captured nominal data (given by the LTs used as a gauge instrument) and the data obtained by the AACMM and compares the measured and calculated coordinates of the target to obtain the identified model parameters that minimize this difference. Finally, results show that the procedure presented, using the measurements of the LTs as a gauge instrument, is very effective by improving the AACMM precision. PMID:24688418

  11. Strategy for non-contact freeform measurements with a cylinder coordinate measuring instrument

    NASA Astrophysics Data System (ADS)

    Beutler, A.

    2015-10-01

    The strategy for measuring and analyzing freeforms with a new high precision cylinder coordinate measuring instrument equipped with an optical point sensor is presented. As freeforms compared to aspheres are not rotationally symmetric considering outline and shape the measuring process has to be designed in new ways. In addition fiducials on the sample or fixture have to be measured to determine position and orientation, i.e. a coordinate system, of the sample. In the following analysis process this coordinate system has to be taken into account. The performance of the measuring instrument is demonstrated and measuring results of different samples are shown.

  12. Coordinate measuring machine test standard apparatus and method

    DOEpatents

    Bieg, Lothar F.

    1994-08-30

    A coordinate measuring machine test standard apparatus and method which iudes a rotary spindle having an upper phase plate and an axis of rotation, a kinematic ball mount attached to the phase plate concentric with the axis of rotation of the phase plate, a groove mounted at the circumference of the phase plate, and an arm assembly which rests in the groove. The arm assembly has a small sphere at one end and a large sphere at the other end. The small sphere may be a coordinate measuring machine probe tip and may have variable diameters. The large sphere is secured in the kinematic ball mount and the arm is held in the groove. The kinematic ball mount includes at least three mounting spheres and the groove is an angular locating groove including at least two locking spheres. The arm may have a hollow inner core and an outer layer. The rotary spindle may be a ratio reducer. The device is used to evaluate the measuring performance of a coordinate measuring machine for periodic recertification, including 2 and 3 dimensional accuracy, squareness, straightness, and angular accuracy.

  13. Coordinate measuring machine test standard apparatus and method

    DOEpatents

    Bieg, L.F.

    1994-08-30

    A coordinate measuring machine test standard apparatus and method are disclosed which includes a rotary spindle having an upper phase plate and an axis of rotation, a kinematic ball mount attached to the phase plate concentric with the axis of rotation of the phase plate, a groove mounted at the circumference of the phase plate, and an arm assembly which rests in the groove. The arm assembly has a small sphere at one end and a large sphere at the other end. The small sphere may be a coordinate measuring machine probe tip and may have variable diameters. The large sphere is secured in the kinematic ball mount and the arm is held in the groove. The kinematic ball mount includes at least three mounting spheres and the groove is an angular locating groove including at least two locking spheres. The arm may have a hollow inner core and an outer layer. The rotary spindle may be a ratio reducer. The device is used to evaluate the measuring performance of a coordinate measuring machine for periodic recertification, including 2 and 3 dimensional accuracy, squareness, straightness, and angular accuracy. 5 figs.

  14. Advanced coordinate measuring machine at Sandia National Laboratories/California

    SciTech Connect

    Pilkey, R.D.; Klevgard, P.A.

    1993-03-01

    Sandia National Laboratories/California has acquired a new Moore M-48V CNC five-axis universal coordinate measuring machine (CMM). Site preparation, acceptance testing, and initial performance results are discussed. Unique features of the machine include a ceramic ram and vacuum evacuated laser pathways (VELPS). The implementation of a VELPS system on the machine imposed certain design requirements and entailed certain start-up problems. The machine's projected capabilities, workload, and research possibilities are outlined.

  15. Advanced coordinate measuring machine at Sandia National Laboratories/California

    SciTech Connect

    Pilkey, R.D.; Klevgard, P.A.

    1993-03-01

    Sandia National Laboratories/California has acquired a new Moore M-48V CNC five-axis universal coordinate measuring machine (CMM). Site preparation, acceptance testing, and initial performance results are discussed. Unique features of the machine include a ceramic ram and vacuum evacuated laser pathways (VELPS). The implementation of a VELPS system on the machine imposed certain design requirements and entailed certain start-up problems. The machine`s projected capabilities, workload, and research possibilities are outlined.

  16. Flexible coordinate measurement system based on robot for industries

    NASA Astrophysics Data System (ADS)

    Guo, Yin; Yang, Xue-you; Liu, Chang-jie; Ye, Sheng-hua

    2010-10-01

    The flexible coordinate measurement system based on robot which is applicable to multi-model vehicle is designed to meet the needs of online measurement for current mainstream mixed body-in-white(BIW) production line. The moderate precision, good flexibility and no blind angle are the benefits of this measurement system. According to the measurement system, a monocular structured light vision sensor has been designed, which can measure not only edges, but also planes, apertures and other features. And a effective way to fast on-site calibration of the whole system using the laser tracker has also been proposed, which achieves the unity of various coordinate systems in industrial fields. The experimental results show satisfactory precision of +/-0.30mm of this measurement system, which is sufficient for the needs of online measurement for body-in-white(BIW) in the auto production line. The system achieves real-time detection and monitoring of the whole process of the car body's manufacture, and provides a complete data support in purpose of overcoming the manufacturing error immediately and accurately and improving the manufacturing precision.

  17. Project Vesta: A Laboratory Exercise on the Measurement of Celestial Coordinates

    ERIC Educational Resources Information Center

    Laird, David E.

    1974-01-01

    Described is an activity that was developed to measure celestial coordinates. Pictures were taken of the asteroid Vesta, coordinates for reference stars determined, and then celestial coordinates of Vesta were determined with assistance of a computer. (RH)

  18. Statistical process control (SPC) for coordinate measurement machines

    SciTech Connect

    Escher, R.N.

    2000-01-04

    The application of process capability analysis, using designed experiments, and gage capability studies as they apply to coordinate measurement machine (CMM) uncertainty analysis and control will be demonstrated. The use of control standards in designed experiments, and the use of range charts and moving range charts to separate measurement error into it's discrete components will be discussed. The method used to monitor and analyze the components of repeatability and reproducibility will be presented with specific emphasis on how to use control charts to determine and monitor CMM performance and capability, and stay within your uncertainty assumptions.

  19. Unique sensor fusion system for coordinate-measuring machine tasks

    NASA Astrophysics Data System (ADS)

    Nashman, Marilyn; Yoshimi, Billibon; Hong, Tsai Hong; Rippey, William G.; Herman, Martin

    1997-09-01

    This paper describes a real-time hierarchical system that fuses data from vision and touch sensors to improve the performance of a coordinate measuring machine (CMM) used for dimensional inspection tasks. The system consists of sensory processing, world modeling, and task decomposition modules. It uses the strengths of each sensor -- the precision of the CMM scales and the analog touch probe and the global information provided by the low resolution camera -- to improve the speed and flexibility of the inspection task. In the experiment described, the vision module performs all computations in image coordinate space. The part's boundaries are extracted during an initialization process and then the probe's position is continuously updated as it scans and measures the part surface. The system fuses the estimated probe velocity and distance to the part boundary in image coordinates with the estimated velocity and probe position provided by the CMM controller. The fused information provides feedback to the monitor controller as it guides the touch probe to scan the part. We also discuss integrating information from the vision system and the probe to autonomously collect data for 2-D to 3-D calibration, and work to register computer aided design (CAD) models with images of parts in the workplace.

  20. Decision-making ability of Physarum polycephalum enhanced by its coordinated spatiotemporal oscillatory dynamics.

    PubMed

    Iwayama, Koji; Zhu, Liping; Hirata, Yoshito; Aono, Masashi; Hara, Masahiko; Aihara, Kazuyuki

    2016-06-01

    An amoeboid unicellular organism, a plasmodium of the true slime mold Physarum polycephalum, exhibits complex spatiotemporal oscillatory dynamics and sophisticated information processing capabilities while deforming its amorphous body. We previously devised an 'amoeba-based computer (ABC),' that implemented optical feedback control to lead this amoeboid organism to search for a solution to the traveling salesman problem (TSP). In the ABC, the shortest TSP route (the optimal solution) is represented by the shape of the organism in which the body area (nutrient absorption) is maximized while the risk of being exposed to aversive light stimuli is minimized. The shortness of the TSP route found by ABC, therefore, serves as a quantitative measure of the optimality of the decision made by the organism. However, it remains unclear how the decision-making ability of the organism originates from the oscillatory dynamics of the organism. We investigated the number of coexisting traveling waves in the spatiotemporal patterns of the oscillatory dynamics of the organism. We show that a shorter TSP route can be found when the organism exhibits a lower number of traveling waves. The results imply that the oscillatory dynamics are highly coordinated throughout the global body. Based on the results, we discuss the fact that the decision-making ability of the organism can be enhanced not by uncorrelated random fluctuations, but by its highly coordinated oscillatory dynamics. PMID:27070463

  1. Spatially coordinated dynamic gene transcription in living pituitary tissue

    PubMed Central

    Featherstone, Karen; Hey, Kirsty; Momiji, Hiroshi; McNamara, Anne V; Patist, Amanda L; Woodburn, Joanna; Spiller, David G; Christian, Helen C; McNeilly, Alan S; Mullins, John J; Finkenstädt, Bärbel F; Rand, David A; White, Michael RH; Davis, Julian RE

    2016-01-01

    Transcription at individual genes in single cells is often pulsatile and stochastic. A key question emerges regarding how this behaviour contributes to tissue phenotype, but it has been a challenge to quantitatively analyse this in living cells over time, as opposed to studying snap-shots of gene expression state. We have used imaging of reporter gene expression to track transcription in living pituitary tissue. We integrated live-cell imaging data with statistical modelling for quantitative real-time estimation of the timing of switching between transcriptional states across a whole tissue. Multiple levels of transcription rate were identified, indicating that gene expression is not a simple binary ‘on-off’ process. Immature tissue displayed shorter durations of high-expressing states than the adult. In adult pituitary tissue, direct cell contacts involving gap junctions allowed local spatial coordination of prolactin gene expression. Our findings identify how heterogeneous transcriptional dynamics of single cells may contribute to overall tissue behaviour. DOI: http://dx.doi.org/10.7554/eLife.08494.001 PMID:26828110

  2. COSPAR, IAU, LSI Colloquium on Lunar Dynamics and Observational Coordinate Systems: Revised abstracts

    NASA Technical Reports Server (NTRS)

    Moutsoulas, M. (Editor)

    1973-01-01

    The proceedings of a colloquium on lunar dynamics and observational coordinate systems are presented. Discussions were held on the establishment of a fundamental reference system and on the lunar ephemerides. Abstracts of the subjects discussed at the meeting are submitted. Some of the topics discussed are: (1) coordinates of the Apollo retroreflectors, (2) determination of lunar baselines, (3) numerical series for the variations of lunar coordinates, (4) fundamental craters for establishing a lunar coordinate system, and (5) composite lunar gravity fields.

  3. Dimensional coordinate measurements: application in characterizing cervical spine motion

    NASA Astrophysics Data System (ADS)

    Zheng, Weilong; Li, Linan; Wang, Shibin; Wang, Zhiyong; Shi, Nianke; Xue, Yuan

    2014-06-01

    Cervical spine as a complicated part in the human body, the form of its movement is diverse. The movements of the segments of vertebrae are three-dimensional, and it is reflected in the changes of the angle between two joint and the displacement in different directions. Under normal conditions, cervical can flex, extend, lateral flex and rotate. For there is no relative motion between measuring marks fixed on one segment of cervical vertebra, the cervical vertebrae with three marked points can be seen as a body. Body's motion in space can be decomposed into translational movement and rotational movement around a base point .This study concerns the calculation of dimensional coordinate of the marked points pasted to the human body's cervical spine by an optical method. Afterward, these measures will allow the calculation of motion parameters for every spine segment. For this study, we choose a three-dimensional measurement method based on binocular stereo vision. The object with marked points is placed in front of the CCD camera. Through each shot, we will get there two parallax images taken from different cameras. According to the principle of binocular vision we can be realized three-dimensional measurements. Cameras are erected parallelly. This paper describes the layout of experimental system and a mathematical model to get the coordinates.

  4. Motor Coordination Dynamics Underlying Graphic Motion in 7- to 11-Year-Old Children

    ERIC Educational Resources Information Center

    Danna, Jeremy; Enderli, Fabienne; Athenes, Sylvie; Zanone, Pier-Giorgio

    2012-01-01

    Using concepts and tools of a dynamical system approach in order to understand motor coordination underlying graphomotor skills, the aim of the current study was to establish whether the basic coordination dynamics found in adults is already established in children at elementary school, when handwriting is trained and eventually acquired. In the…

  5. Dynamic Assessment of Binocular Eye Movement Coordination: Norms and Functional Implications

    PubMed Central

    Viirre, Erik

    2014-01-01

    Alignment of the two eyes is controlled by a finely tuned, fast acting system with components within the brain. Assessment of binocular alignment has classically been done statically. Eye positions are assessed in primary position and at eccentric angles to interpret the functional status of the oculomotor nerves and muscles. However, assessment of dynamic eye alignment, the coordination of the eyes during eye movements, has been less commonly carried out and has not been formalized with population norms. Clinicians are aware of slow eye movement dynamic alignment changes, such as that clinically observed in Intranuclear Ophthalmoplegia. But assessment of eye alignment during rapid eye movements, such as saccade or pursuit has not been part of neuro-ophthalmologic assessment. With the advent of inexpensive, high resolution recording systems, both eyes can be simultaneously recorded and their coordination during movement compared. Thus, we now have an opportunity to provide a laboratory based objective measurement of a gamut of binocular coordination systems. Recent research in humans has demonstrated increased variability of binocular coordination during divided attention. Variability is an interesting statistic that can be sensitively assessed in the velocity domain without extensive gaze position recalibration procedures during recording over long intervals. Variability can thus be used as a robust, long-term eye movement parameter with minimal intrusiveness to the subject. It is proposed that population studies of binocular coordination during eye movements be carried out to determine neurologic norms so that conditions such as brain injury and others can be assessed with a functional tool with objective parameters. PMID:24804278

  6. Extracting numeric measurements and temporal coordinates from Japanese radiological reports

    NASA Astrophysics Data System (ADS)

    Imai, Takeshi; Onogi, Yuzo

    2004-04-01

    Medical records are written mainly, in natural language. The focus of this study is narrative radiological reports written in natural Japanese. These reports cannot be used for advanced retrieval, data mining, and so on, unless they are stored, using a structured format such as DICOM-SR. The goal is to structure narrative reports progressively, using natural language processing (NLP). Structure has many different levels, for example, DICOM-SR has three established levels -- basic text, enhanced and comprehensive. At the enhanced level, it is necessary to use numerical measurements and spatial & temporal coordinates. In this study, the wording used in the reports was first standardized, dictionaries were organized, and morphological analysis performed. Next, numerical measurements and temporal coordinates were extracted, and the objects to which they referred, analyzed. 10,000 CT and MR reports were separated into 82,122 sentences, and 34,269 of the 36,444 numerical descriptions were tagged. Periods, slashes, hyphens, and parentheses are ambiguously used in the description of enumerated lists, dates, image numbers, and anatomical names, as well as at the end of sentences; to resolve this ambiguity, descriptions were processed, according to the order -- date, size, unit, enumerated list, and abbreviation -- then, the tagged reports were separated into sentences.

  7. Reference coordinate systems for Earth dynamics: A preview

    NASA Technical Reports Server (NTRS)

    Mueller, I. I.

    1982-01-01

    Geodynamics is the subject of intensive international research during last decade. A common requirement for all investigations is the necessity of a well defined coordinate system attached to the Earth in some prescribed way. In addition, a well defined inertial coordinate system is also needed in which the motions of the terrestrial system can be monitored. The problems encountered when establishing such coordinate systems and the transformations between them are presented. In addition, problems related to the modeling of the deformable Earth are discussed. Finally, action items are listed which are necessary to assure that the reference system issue is resolved early and that uniformity is assured by means of international agreements.

  8. Determination of RGB Color Coordinates from Spectroscopic Reflectance Measurements

    NASA Astrophysics Data System (ADS)

    Rodriguez, Cesar; Nelson, Cayla; Abdallah, Lina; Zollner, Stefan

    2012-10-01

    A numerical value (RGB coordinate) for a certain color, based on a color model, can be determined from a spectroscopic reflectance measurement. To obtain this measurement, an ellipsometer was used with a wavelength ranging from 380 nm to 780 nm to cover the visible light spectrum. The peaks seen in the reflectance versus wavelength graph represent the color of the sample used. Our paper samples were round and coated with a metallic paint. The data was then analyzed using ASTM Standard E308-99 (adopted in 1999) for ``computing the colors of objects by using the CIE system.'' Once a color is in the CIE color model, it can be transformed into an RGB color model and then compared to the RGB color displayed in many consumer electronics.

  9. Some notions of decentralization and coordination in large-scale dynamic systems

    NASA Technical Reports Server (NTRS)

    Chong, C. Y.

    1975-01-01

    Some notions of decentralization and coordination in the control of large-scale dynamic systems are discussed. Decentralization and coordination have always been important concepts in the study of large systems. Roughly speaking decentralization is the process of dividing a large problem into subproblems so that it can be handled more easily. Coordination is the manipulation of the subproblem so that the original problem is solved. The various types of decentralization and coordination that have been used to control dynamic systems are discussed. The emphasis was to distinguish between on-line and off-line operations to understand the results available by indicating the aspects of the problem which are decentralized.

  10. Reaction coordinates, one-dimensional Smoluchowski equations, and a test for dynamical self-consistency

    NASA Astrophysics Data System (ADS)

    Peters, Baron; Bolhuis, Peter G.; Mullen, Ryan G.; Shea, Joan-Emma

    2013-02-01

    We propose a method for identifying accurate reaction coordinates among a set of trial coordinates. The method applies to special cases where motion along the reaction coordinate follows a one-dimensional Smoluchowski equation. In these cases the reaction coordinate can predict its own short-time dynamical evolution, i.e., the dynamics projected from multiple dimensions onto the reaction coordinate depend only on the reaction coordinate itself. To test whether this property holds, we project an ensemble of short trajectory swarms onto trial coordinates and compare projections of individual swarms to projections of the ensemble of swarms. The comparison, quantified by the Kullback-Leibler divergence, is numerically performed for each isosurface of each trial coordinate. The ensemble of short dynamical trajectories is generated only once by sampling along an initial order parameter. The initial order parameter should separate the reactants and products with a free energy barrier, and distributions on isosurfaces of the initial parameter should be unimodal. The method is illustrated for three model free energy landscapes with anisotropic diffusion. Where exact coordinates can be obtained from Kramers-Langer-Berezhkovskii-Szabo theory, results from the new method agree with the exact results. We also examine characteristics of systems where the proposed method fails. We show how dynamical self-consistency is related (through the Chapman-Kolmogorov equation) to the earlier isocommittor criterion, which is based on longer paths.

  11. Dynamic aperture measurement on Aladdin

    SciTech Connect

    Bridges, J.; Cho, Y.; Chou, W.; Crosbie, E.; Kramer, S.; Kustom, R.; Voss, D.; Teng, L.; Kleman, K.; Otte, R.; Trzeciak, W.; Symon, K.; Wisconsin Univ., Stoughton, WI . Synchrotron Radiation Center; Wisconsin Univ., Madison, WI . Dept. of Physics)

    1989-01-01

    The sextupole-induced non-linear transverse beam dynamics in the synchrotron radiation storage ring Aladdin is studied. Specifically, the dynamic aperture is measured as function of the sextupole strength. The results agree reasonably well with computer simulations. 1 ref., 8 figs., 1 tab.

  12. Mutual and asynchronous anticipation and action in sports as globally competitive and locally coordinative dynamics

    PubMed Central

    Fujii, Keisuke; Isaka, Tadao; Kouzaki, Motoki; Yamamoto, Yuji

    2015-01-01

    Humans interact by changing their actions, perceiving other’s actions and executing solutions in conflicting situations. Using oscillator models, nonlinear dynamics have been considered for describing these complex human movements as an emergence of self-organisation. However, these frameworks cannot explain the hierarchical structures of complex behaviours between conflicting inter-agent and adapting intra-agent systems, especially in sport competitions wherein mutually quick decision making and execution are required. Here we adopt a hybrid multiscale approach to model an attack-and-defend game during which both players predict the opponent’s movement and move with a delay. From both simulated and measured data, one synchronous outcome between two-agent (i.e. successful defence) can be described as one attractor. In contrast, the other coordination-breaking outcome (i.e. successful attack) cannot be explained using gradient dynamics because the asymmetric interaction cannot always assume a conserved physical quantity. Instead, we provide the asymmetric and asynchronous hierarchical dynamical models to discuss two-agent competition. Our framework suggests that possessing information about an opponent and oneself in local-coordinative and global-competitive scale enables us to gain a deeper understanding of sports competitions. We anticipate developments in the scientific fields of complex movement adapting to such uncontrolled environments. PMID:26538452

  13. Mutual and asynchronous anticipation and action in sports as globally competitive and locally coordinative dynamics

    NASA Astrophysics Data System (ADS)

    Fujii, Keisuke; Isaka, Tadao; Kouzaki, Motoki; Yamamoto, Yuji

    2015-11-01

    Humans interact by changing their actions, perceiving other’s actions and executing solutions in conflicting situations. Using oscillator models, nonlinear dynamics have been considered for describing these complex human movements as an emergence of self-organisation. However, these frameworks cannot explain the hierarchical structures of complex behaviours between conflicting inter-agent and adapting intra-agent systems, especially in sport competitions wherein mutually quick decision making and execution are required. Here we adopt a hybrid multiscale approach to model an attack-and-defend game during which both players predict the opponent’s movement and move with a delay. From both simulated and measured data, one synchronous outcome between two-agent (i.e. successful defence) can be described as one attractor. In contrast, the other coordination-breaking outcome (i.e. successful attack) cannot be explained using gradient dynamics because the asymmetric interaction cannot always assume a conserved physical quantity. Instead, we provide the asymmetric and asynchronous hierarchical dynamical models to discuss two-agent competition. Our framework suggests that possessing information about an opponent and oneself in local-coordinative and global-competitive scale enables us to gain a deeper understanding of sports competitions. We anticipate developments in the scientific fields of complex movement adapting to such uncontrolled environments.

  14. Tortoise Coordinate Transformation on Apparent Horizon of a Dynamical Black Hole

    NASA Astrophysics Data System (ADS)

    Liu, Xianming; Zhao, Zheng; Liu, Wenbiao

    Thinking of Hawking radiation calculation from a Schwarzschild black hole using Damour-Ruffini method, some key requirements of the tortoise coordinate transformation are pointed out. Extending these requirements to a dynamical black hole, a dynamical tortoise coordinate transformation is proposed. Under this new dynamical tortoise coordinate transformation, Hawking radiation from a Vaidya black hole can be got successfully using Damour-Ruffini method. Moreover, we also find that the radiation should be regarded as originating from the apparent horizon rather than the event horizon at least from the viewpoint of the first law of thermodynamics.

  15. Control systems improvements in a precision coordinate measuring machine

    NASA Astrophysics Data System (ADS)

    Douglass, S. S.; Babelay, E. F., Jr.; Igou, R. E.; Woodard, L. M.; Green, W. L.

    1981-09-01

    A conventional, manually driven Moore No. 3 coordinate measuring machine at the Oak Ridge Y-12 Plant is being upgraded to provide a continuous-path numerical control capability and simultaneously serve as a vehicle for testing new machine slide-control concepts. Besides new lead screw drive motors, an NC machine control unit, and a closed-loop servo system, the machine has also been equipped with vibration isolation, air-bearing slideways, and laser interferometric position feedback. The present conventional slide servo system will be replaced with a digital servo system wherein various feedback and compensation techniques can be realized through the use of a high speed, dedicated digital processor. The improvements to data are described with emphasis on identification and compensation of the slide control systems.

  16. Analysis of Spherical Form Errors to Coordinate Measuring Machine Data

    NASA Astrophysics Data System (ADS)

    Chen, Mu-Chen

    Coordinates measuring machines (CMMs) are commonly utilized to take measurement data from manufactured surfaces for inspection purposes. The measurement data are then used to evaluate the geometric form errors associated with the surface. Traditionally, the evaluation of spherical form errors involves an optimization process of fitting a substitute sphere to the sampled points. This paper proposes the computational strategies for sphericity with respect to ASME Y14.5M-1994 standard. The proposed methods consider the trade-off between the accuracy of sphericity and the efficiency of inspection. Two approaches of computational metrology based on genetic algorithms (GAs) are proposed to explore the optimality of sphericity measurements and the sphericity feasibility analysis, respectively. The proposed algorithms are verified by using several CMM data sets. Observing from the computational results, the proposed algorithms are practical for on-line implementation to the sphericity evaluation. Using the GA-based computational techniques, the accuracy of sphericity assessment and the efficiency of sphericity feasibility analysis are agreeable.

  17. Optimal Sampling of a Reaction Coordinate in Molecular Dynamics

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew

    2005-01-01

    Estimating how free energy changes with the state of a system is a central goal in applications of statistical mechanics to problems of chemical or biological interest. From these free energy changes it is possible, for example, to establish which states of the system are stable, what are their probabilities and how the equilibria between these states are influenced by external conditions. Free energies are also of great utility in determining kinetics of transitions between different states. A variety of methods have been developed to compute free energies of condensed phase systems. Here, I will focus on one class of methods - those that allow for calculating free energy changes along one or several generalized coordinates in the system, often called reaction coordinates or order parameters . Considering that in almost all cases of practical interest a significant computational effort is required to determine free energy changes along such coordinates it is hardly surprising that efficiencies of different methods are of great concern. In most cases, the main difficulty is associated with its shape along the reaction coordinate. If the free energy changes markedly along this coordinate Boltzmann sampling of its different values becomes highly non-uniform. This, in turn, may have considerable, detrimental effect on the performance of many methods for calculating free energies.

  18. Molecular dynamics simulation of alkali borate glass using coordination dependent potential

    SciTech Connect

    Park, B.; Cormack, A.N.

    1997-12-31

    The structure of sodium borate glass was investigated by molecular dynamics simulation using coordination dependent potential model. The simulated alkali borate glass consists of basic units, BO{sub 3} triangle, BO{sub 4} tetrahedra and structural groups such as boroxol ring and triborate units. The coordination of boron is converted from 3 to 4 by adding alkali oxide.

  19. Contouring error compensation on a micro coordinate measuring machine

    NASA Astrophysics Data System (ADS)

    Fan, Kuang-Chao; Wang, Hung-Yu; Ye, Jyun-Kuan

    2011-12-01

    In recent years, three-dimensional measurements of nano-technology researches have received a great attention in the world. Based on the high accuracy demand, the error compensation of measurement machine is very important. In this study, a high precision Micro-CMM (coordinate measuring machine) has been developed which is composed of a coplanar stage for reducing the Abbé error in the vertical direction, the linear diffraction grating interferometer (LDGI) as the position feedback sensor in nanometer resolution, and ultrasonic motors for position control. This paper presents the error compensation strategy including "Home accuracy" and "Position accuracy" in both axes. For the home error compensation, we utilize a commercial DVD pick-up head and its S-curve principle to accurately search the origin of each axis. For the positioning error compensation, the absolute positions relative to the home are calibrated by laser interferometer and the error budget table is stored for feed forward error compensation. Contouring error can thus be compensated if both the compensation of both X and Y positioning errors are applied. Experiments show the contouring accuracy can be controlled to within 50nm after compensation.

  20. Instrument measures dynamic pressure fluctuations

    NASA Technical Reports Server (NTRS)

    Coats, J. W.; Penko, P. E.; Reshotko, M.

    1977-01-01

    Pressure probe instrument, incorporating "infinite line" principle, can be used to remotely measure dynamic pressure fluctuations in hot high-pressure environemnts too severe for sensors. System is designed and can be utilized for measurements in core of operating turbofan engine.

  1. Mass properties measurement system dynamics

    NASA Technical Reports Server (NTRS)

    Doty, Keith L.

    1993-01-01

    The MPMS mechanism possess two revolute degrees-of-freedom and allows the user to measure the mass, center of gravity, and the inertia tensor of an unknown mass. The dynamics of the Mass Properties Measurement System (MPMS) from the Lagrangian approach to illustrate the dependency of the motion on the unknown parameters.

  2. Bio-Inspired Metal-Coordination Dynamics: A Unique Tool for Engineering Soft Matter Mechanics

    NASA Astrophysics Data System (ADS)

    Holten-Andersen, Niels

    Growing evidence supports a critical role of metal-coordination in soft biological material properties such as self-healing, underwater adhesion and autonomous wound plugging. Using bio-inspired metal-binding polymers, initial efforts to mimic these properties with metal-coordination crosslinked polymer materials have shown promise. In addition, with polymer network mechanics strongly coupled to coordinate crosslink dynamics material properties can be easily tuned from visco-elastic fluids to solids. Given their exploitation in desirable material applications in Nature, bio-inspired metal-coordinate complex crosslinking provides an opportunity to further advance synthetic polymer materials design. Early lessons from this pursuit are presented.

  3. Coordinated weather balloon solar radiation measurements during a solar eclipse.

    PubMed

    Harrison, R G; Marlton, G J; Williams, P D; Nicoll, K A

    2016-09-28

    Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'. PMID:27550757

  4. Stochastic evolutionary dynamics in minimum-effort coordination games

    NASA Astrophysics Data System (ADS)

    Li, Kun; Cong, Rui; Wang, Long

    2016-08-01

    The minimum-effort coordination game draws recently more attention for the fact that human behavior in this social dilemma is often inconsistent with the predictions of classical game theory. Here, we combine evolutionary game theory and coalescence theory to investigate this game in finite populations. Both analytic results and individual-based simulations show that effort costs play a key role in the evolution of contribution levels, which is in good agreement with those observed experimentally. Besides well-mixed populations, set structured populations have also been taken into consideration. Therein we find that large number of sets and moderate migration rate greatly promote effort levels, especially for high effort costs.

  5. The role of general dynamic coordination in the handwriting skills of children

    PubMed Central

    Scordella, Andrea; Di Sano, Sergio; Aureli, Tiziana; Cerratti, Paola; Verratti, Vittore; Fanò-Illic, Giorgio; Pietrangelo, Tiziana

    2015-01-01

    Difficulties in handwriting are often reported in children with developmental coordination disorder, and they represent an important element in the diagnosis. The present study was aimed at investigating the relation between motor coordination and handwriting skills, and to identify differences in handwriting between children without and with coordination difficulties. In particular, we asked whether visual–spatial skills have a role as mediating variables between motor coordination and handwriting. We assessed motor coordination as well as graphic abilities in children aged 7–10 years. Moreover, we evaluated their visual–motor integration, visual–spatial skills, and other cognitive abilities (memory and planning). We found no relation between motor coordination and handwriting skills, while visual–spatial skills (measured by a visual-constructive task) were related with both. Our conclusion is that visual–spatial skills are involved both in general motor coordination and in handwriting, but the relationship involves different aspects in the two cases. PMID:25999893

  6. Measuring mitotic spindle dynamics in budding yeast

    NASA Astrophysics Data System (ADS)

    Plumb, Kemp

    In order to carry out its life cycle and produce viable progeny through cell division, a cell must successfully coordinate and execute a number of complex processes with high fidelity, in an environment dominated by thermal noise. One important example of such a process is the assembly and positioning of the mitotic spindle prior to chromosome segregation. The mitotic spindle is a modular structure composed of two spindle pole bodies, separated in space and spanned by filamentous proteins called microtubules, along which the genetic material of the cell is held. The spindle is responsible for alignment and subsequent segregation of chromosomes into two equal parts; proper spindle positioning and timing ensure that genetic material is appropriately divided amongst mother and daughter cells. In this thesis, I describe fluorescence confocal microscopy and automated image analysis algorithms, which I have used to observe and analyze the real space dynamics of the mitotic spindle in budding yeast. The software can locate structures in three spatial dimensions and track their movement in time. By selecting fluorescent proteins which specifically label the spindle poles and cell periphery, mitotic spindle dynamics have been measured in a coordinate system relevant to the cell division. I describe how I have characterised the accuracy and precision of the algorithms by simulating fluorescence data for both spindle poles and the budding yeast cell surface. In this thesis I also describe the construction of a microfluidic apparatus that allows for the measurement of long time-scale dynamics of individual cells and the development of a cell population. The tools developed in this thesis work will facilitate in-depth quantitative analysis of the non-equilibrium processes in living cells.

  7. Incorporating coordination dynamics into an evolutionarily grounded science of intentional change.

    PubMed

    Kostrubiec, Viviane; Kelso, J A Scott

    2014-08-01

    We suggest the authors' endeavor toward a science of intentional change may benefit from recent advances in informationally meaningful self-organizing dynamical systems. Coordination Dynamics, having contributed to an understanding of behavior on several time scales - adaptation, learning, and development - and on different levels of analysis, from the neural to the social, may complement, if not enhance, the authors' insights. PMID:25162873

  8. A simple procedure to include a free-form measurement capability to standard coordinate measurement machines

    NASA Astrophysics Data System (ADS)

    Schneider, Florian; Rascher, Rolf; Stamp, Richard; Smith, Gordon

    2013-09-01

    The modern optical industry requires objects with complex topographical structures. Free-form shaped objects are of large interest in many branches, especially for size reduced, modern lifestyle products like digital cameras. State of the art multi-axes-coordinate measurement machines (CMM), like the topographical measurement machine TII-3D, are by principle suitable to measure free-form shaped objects. The only limitation is the software package. This paper may illustrate a simple way to enhance coordinate measurement machines in order to add a free-form function. Next to a coordinate measurement machine, only a state of the art CAD† system and a simple piece of software are necessary. For this paper, the CAD software CREO‡ had been used. CREO enables the user to develop a 3D object in two different ways. With the first method, the user might design the shape by drawing one or more 2D sketches and put an envelope around. Using the second method, the user could define one or more formulas in the editor to describe the favoured surface. Both procedures lead to the required three-dimensional shape. However, further features of CREO enable the user to export the XYZ-coordinates of the created surface. A special designed software tool, developed with Matlab§, converts the XYZ-file into a measurement matrix which can be used as a reference file. Finally the result of the free-form measurement, carried out with a CMM, has to be loaded into the software tool and both files will be computed. The result is an error profile which provides the deviation between the measurement and the target-geometry.

  9. Mg2+ coordinating dynamics in Mg:ATP fueled motor proteins

    NASA Astrophysics Data System (ADS)

    Bojovschi, A.; Liu, Ming S.; Sadus, Richard J.

    2014-03-01

    The coordination of Mg2+ with the triphosphate group of adenosine triphosphate (ATP) in motor proteins is investigated using data mining and molecular dynamics. The possible coordination structures available from crystal data for actin, myosin, RNA polymerase, DNA polymerase, DNA helicase, and F1-ATPase are verified and investigated further by molecular dynamics. Coordination states are evaluated using structural analysis and quantified by radial distribution functions, coordination numbers, and pair interaction energy calculations. The results reveal a diverse range of both transitory and stable coordination arrangements between Mg2+ and ATP. The two most stable coordinating states occur when Mg2+ coordinates two or three oxygens from the triphosphate group of ATP. Evidence for five-site coordination is also reported involving water in addition to the triphosphate group. The stable states correspond to a pair interaction energy of either ˜-2750 kJ/mol or -3500 kJ/mol. The role of water molecules in the hydration shell surrounding Mg2+ is also reported.

  10. Equations of nonlinear dynamics of elastic shells in cylindrical Eulerian coordinates

    NASA Astrophysics Data System (ADS)

    Zubov, L. M.

    2016-05-01

    The equations of dynamics of elastic shells subjected to large deformations are formulated. The Eulerian coordinates on a circular cylinder and time are accepted as independent variables, and one of the unknown functions is the distance from a point of the shell surface to the cylinder axis. The equations of dynamics of nonlinearly elastic shells in the Eulerian coordinates are convenient for exact formulation of the problem on the interaction of strongly deformable shells with moving fluids and gases. The equations obtained can be used for dynamic calculations of fluids and gases flowings in pipelines, blood vessels, hoses, and other nonlinearly deformable thin-walled tubular elements of constructions.

  11. Approximating high-dimensional dynamics by barycentric coordinates with linear programming

    SciTech Connect

    Hirata, Yoshito Aihara, Kazuyuki; Suzuki, Hideyuki; Shiro, Masanori; Takahashi, Nozomu; Mas, Paloma

    2015-01-15

    The increasing development of novel methods and techniques facilitates the measurement of high-dimensional time series but challenges our ability for accurate modeling and predictions. The use of a general mathematical model requires the inclusion of many parameters, which are difficult to be fitted for relatively short high-dimensional time series observed. Here, we propose a novel method to accurately model a high-dimensional time series. Our method extends the barycentric coordinates to high-dimensional phase space by employing linear programming, and allowing the approximation errors explicitly. The extension helps to produce free-running time-series predictions that preserve typical topological, dynamical, and/or geometric characteristics of the underlying attractors more accurately than the radial basis function model that is widely used. The method can be broadly applied, from helping to improve weather forecasting, to creating electronic instruments that sound more natural, and to comprehensively understanding complex biological data.

  12. Plasmodesmata dynamics are coordinated by intracellular signaling pathways

    PubMed Central

    Brunkard, Jacob O.; Runkel, Anne M.; Zambryski, Patricia C.

    2013-01-01

    Membrane-lined channels called plasmodesmata (PD) connect the cytoplasts of adjacent plant cells across the cell wall, permitting intercellular movement of small molecules, proteins, and RNA. Recent genetic screens for mutants with altered PD transport identified genes suggesting that chloroplasts play crucial roles in coordinating PD transport. Complementing this discovery, studies manipulating expression of PD-localized proteins imply that changes in PD transport strongly impact chloroplast biology. Ongoing efforts to find genes that control root and stomatal development reveal the critical role of PD in enforcing tissue patterning, and newly discovered PD-localized proteins show that PD influence development, intracellular signaling, and defense against pathogens. Together, these studies demonstrate that PD function and formation are tightly integrated with plant physiology. PMID:23978390

  13. Imperfection and Thickness Measurement of Panels Using a Coordinate Measurement Machine

    NASA Technical Reports Server (NTRS)

    Thornburgh, Robert P.

    2006-01-01

    This paper summarizes the methodology used to measure imperfection and thickness variation for flat and curved panels using a Coordinate Measurement Machine (CMM) and the software program MeasPanel. The objective is to provide a reference document so that someone with a basic understanding of CMM operation can measure a panel with minimal training. Detailed information about both the measurement system setup and computer software is provided. Information is also provided about the format of the raw data, as well as how it is post-processed for use in finite-element analysis.

  14. Estimation of measuring uncertainty for optical micro-coordinate measuring machine

    NASA Astrophysics Data System (ADS)

    Song, Kang; Jiang, Zhuangde

    2004-12-01

    Based on the evaluation principle of the measuring uncertainty of the traditional coordinate measuring machine (CMM), the analysis and evaluation of the measuring uncertainty for optical micro-CMM have been made. Optical micro-CMM is an integrated measuring system with optical, mechanical, and electronic components, which may influence the measuring uncertainty of the optical micro-CMM. If the influence of laser speckle is taken into account, its longitudinal measuring uncertainty is 2.0 ?m, otherwise it is 0.88 ?m. It is proved that the estimation of the synthetic uncertainty for optical micro-CMM is correct and reliable by measuring the standard reference materials and simulating the influence of the diameter of laser beam. With Heisenberg's uncertainty principle and quantum mechanics theory, a method for improving the measuring accuracy of optical micro-CMM through adding a diaphragm in the receiving terminal of the light path was proposed, and the measuring results are verified by experiments.

  15. Dynamic Coordination Of A Two-Arm Robotic Manipulator

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan; Kim, Sungbok

    1994-01-01

    Report presents study of dynamical and kinematical considerations guiding selection of configuration of self-reconfigurable, two-arm robotic manipulator. Two multiple-link arms cooperate in manipulating single object, reconfiguring their mutual, cooperative structure according to changing task requirements.

  16. General Tortoise Coordinate Transformation in a Dynamical Kerr-Newman Black Hole

    NASA Astrophysics Data System (ADS)

    Liu, Xian-Ming; Cheng, Su-Jun; Liu, Wen-Biao

    2012-02-01

    Under the extended dynamical tortoise coordinate transformation, Damour-Ruffini method has been applied to calculate the charged particles' Hawking radiation from the apparent horizon of a dynamical Kerr-Newman black hole. It is shown that Hawking radiation is still purely thermal black body spectrum. Moreover, the temperature of Hawking radiation is corresponding to the apparent horizon surface gravity and the first law of thermodynamics can also be constructed successfully on the apparent horizon in the dynamical Kerr-Newman black hole.

  17. Evaluation of influence parameters on measurement reliability of coordinated measuring arms

    NASA Astrophysics Data System (ADS)

    Cuesta, E.; Álvarez, B. J.; Martínez, S.; Barreiro, J.; González-Madruga, D.

    2012-04-01

    Coordinate Measuring Arms (PCMAs or CMAs), despite using three-dimensional measurement techniques conceptually similar to the CMMs, are still manual measuring instruments for contact and their reliability requires an analysis of the most significant parameters of influence. In this work two types of tests were performed: in first place measurements of gauge blocks and ring gauges were made using the same CMA by several inspectors, thus simulating a study of repeatability and reproducibility (r&R). Based on preliminary results, a new study was carried out with more geometric features, over a "feature's master part" designed accordingly, and comparing the results with the measurements obtained in a CMM with traceability. This comparison has proven that measurement results are influenced not only by the operator (number and distribution of points, contact force, etc.) but also by the measured feature type and the probe type, thus by the CMA feasibility for measurement.

  18. Emergent complexity matching in interpersonal coordination: Local dynamics and global variability.

    PubMed

    Fine, Justin M; Likens, Aaron D; Amazeen, Eric L; Amazeen, Polemnia G

    2015-06-01

    Rhythmic coordination with stimuli and other people's movements containing variable or unpredictable fluctuations might involve distinct processes: detecting the fluctuation structure and tuning to or matching the structure's temporal complexity. This framework predicts that global tuning and local parameter adjustments (e.g., position, velocity or phase) can operate independently during coordination (Marmelat & Delignières, 2012). Alternatively, we propose that complexity matching is a result of local phase adjustments during coordination (Delignières & Marmelat, 2014; Torre, Varlet, & Marmelat, 2013). The current study examined this relationship in a rhythmic interpersonal coordination task. Dyads coordinated swinging pendulums that differed in their uncoupled frequencies (detuning). We predicted that frequency detuning would require increased local corrections to maintain the intended phase pattern (in phase). This was expected to yield a relative phase shift accompanied by a change in period complexity and matching. Experimental data and numerical modeling of the pendulum dynamics confirmed our predictions. Increased relative phase shifts occurred simultaneously with increased dissociation between individuals' movement period complexity. This provided evidence that global complexity matching is intricately linked to local movement adjustments and is not a distinct coordination mechanism. These findings are considered with respect to dynamical and computational approaches to interpersonal coordination. PMID:25798782

  19. A vision-aided alignment datum system for coordinate measuring machines

    NASA Astrophysics Data System (ADS)

    Wang, L.; Lin, G. C. I.

    1997-07-01

    This paper presents the development of a CAD-based and vision-aided precision measurement system. A new coordinate system alignment technique for coordinate measuring machines (CMMs) is described. This alignment technique involves a machine vision system with CAD-based planning and execution of inspection. The determination method for measuring datums for the coordinate measuring technique, using the AutoCAD development system, is described in more detail. To improve image quality in the machine vision system, a contrast enhancement technique is used on the image background to reduce image noise, and an on-line calibration technique is applied. Some systematic errors may be caused by imperfect geometric features in components during coordinate system alignment. This measurement system approach, with its new measuring coordinate alignment method, can be used for high-precision measurement to overcome such errors.

  20. Deployment dynamics of a simplified spinning IKAROS solar sail via absolute coordinate based method

    NASA Astrophysics Data System (ADS)

    Zhao, Jiang; Tian, Qiang; Hu, Hai-Yan

    2013-02-01

    The spinning solar sail of large scale has been well developed in recent years. Such a solar sail can be considered as a rigid-flexible multibody system mainly composed of a spinning central rigid hub, a number of flexible thin tethers, sail membranes, and tip masses. A simplified interplanetary kite-craft accelerated by radiation of the Sun (IKAROS) model is established in this study by using the absolute-coordinate-based (ACB) method that combines the natural coordinate formulation (NCF) describing the central rigid hub and the absolute nodal coordinate formulation (ANCF) describing flexible parts. The initial configuration of the system in the second-stage deployment is determined through both dynamic and static analyses. The huge set of stiff equations of system dynamics is solved by using the generalized-alpha method, and thus the deployment dynamics of the system can be well understood.

  1. Laser measuring system accurately locates point coordinates on photograph

    NASA Technical Reports Server (NTRS)

    Doede, J. H.; Lindenmeyer, C. W.; Vonderohe, R. H.

    1966-01-01

    Laser activated ultraprecision ranging apparatus interfaced with a computer determines point coordinates on a photograph. A helium-neon gas CW laser provides collimated light for a null balancing optical system. This system has no mechanical connection between the ranging apparatus and the photograph.

  2. Dynamic Models and Coordination Analysis of Reverse Supply Chain with Remanufacturing

    NASA Astrophysics Data System (ADS)

    Yan, Nina

    In this paper, we establish a reverse chain system with one manufacturer and one retailer under demand uncertainties. Distinguishing between the recycling process of the retailer and the remanufacturing process of the manufacturer, we formulate a two-stage dynamic model for reverse supply chain based on remanufacturing. Using buyback contract as coordination mechanism and applying dynamic programming the optimal decision problems for each stage are analyzed. It concluded that the reverse supply chain system could be coordinated under the given condition. Finally, we carry out numerical calculations to analyze the expected profits for the manufacturer and the retailer under different recovery rates and recovery prices and the outcomes validate the theoretical analyses.

  3. Coordinated DNA dynamics during the human telomerase catalytic cycle

    NASA Astrophysics Data System (ADS)

    Parks, Joseph W.; Stone, Michael D.

    2014-06-01

    The human telomerase reverse transcriptase (hTERT) utilizes a template within the integral RNA subunit (hTR) to direct extension of telomeres. Telomerase exhibits repeat addition processivity (RAP) and must therefore translocate the nascent DNA product into a new RNA:DNA hybrid register to prime each round of telomere repeat synthesis. Here, we use single-molecule FRET and nuclease protection assays to monitor telomere DNA structure and dynamics during the telomerase catalytic cycle. DNA translocation during RAP proceeds through a previously uncharacterized kinetic substep during which the 3‧-end of the DNA substrate base pairs downstream within the hTR template. The rate constant for DNA primer realignment reveals this step is not rate limiting for RAP, suggesting a second slow conformational change repositions the RNA:DNA hybrid into the telomerase active site and drives the extrusion of the 5‧-end of the DNA primer out of the enzyme complex.

  4. Low-load coordination dynamics in athletes, physiotherapists, gymnasts, musicians and patients with spinal cord injury, after stroke, traumatic brain lesion and with cerebral palsy.

    PubMed

    Schalow, G; Pääsuke, M

    2003-06-01

    Low-load coordination dynamics were measured in athletes, physiotherapists, gymnasts, musicians and patients after stroke, traumatic brain injury and spinal cord lesion during exercise on a special coordination dynamic therapy device to quantify differences in central nervous system (CNS) organization between healthy subjects and patients with CNS injury. In healthy humans coordination dynamics (arrhythmicity of turning) varied between 5.2 and 6.0 for forward and between 6.9 and 10.7 1/s for backward turning. The frequency of turning varied between 1.24 (athletes) and 1.49 Hz (musicians) for forward and between 1.11 and 1.25 Hz for backward turning. Apart from the poor rhythmicity of backward turning among physiotherapists, gymnasts and musicians, inter-group differences were small in comparison to intra-group variation. In patients with spinal cord lesion the coordination dynamics value was 8.3 for forward and 11.0 for backward turning. The frequencies for forward and backward turning were 1.20 and 1.20 Hz respectively. The values for coordination dynamics and frequency of turning thus did only slightly differ from those measured for healthy subjects. The patients after stroke, traumatic brain injury and cerebral palsy had much higher coordination dynamic values (20.4, 22.9 and 30 1/s respectively) and lower forward (0.85, 0.93, and 0.52 Hz) and backward turning frequencies (0.98, 1.06, 0.42 Hz), suggesting strongly pathologic CNS organization. Low-load coordination dynamics (20N) are thus useful to measure progress in CNS organization due to therapy in patients with CNS injury. PMID:12836583

  5. Coordinated Dynamics of RNA Splicing Speckles in the Nucleus.

    PubMed

    Zhang, Qiao; Kota, Krishna P; Alam, Samer G; Nickerson, Jeffrey A; Dickinson, Richard B; Lele, Tanmay P

    2016-06-01

    Despite being densely packed with chromatin, nuclear bodies and a nucleoskeletal network, the nucleus is a remarkably dynamic organelle. Chromatin loops form and relax, RNA transcripts and transcription factors move diffusively, and nuclear bodies move. We show here that RNA splicing speckled domains (splicing speckles) fluctuate in constrained nuclear volumes and remodel their shapes. Small speckles move in a directed way toward larger speckles with which they fuse. This directed movement is reduced upon decreasing cellular ATP levels or inhibiting RNA polymerase II activity. The random movement of speckles is reduced upon decreasing cellular ATP levels, moderately reduced after inhibition of SWI/SNF chromatin remodeling and modestly increased upon inhibiting RNA polymerase II activity. To define the paths through which speckles can translocate in the nucleus, we generated a pressure gradient to create flows in the nucleus. In response to the pressure gradient, speckles moved along curvilinear paths in the nucleus. Collectively, our results demonstrate a new type of ATP-dependent motion in the nucleus. We present a model where recycling splicing factors return as part of small sub-speckles from distal sites of RNA processing to larger splicing speckles by a directed ATP-driven mechanism through interchromatin spaces. PMID:26496460

  6. Milking the spherical cow - on aspherical dynamics in spherical coordinates

    NASA Astrophysics Data System (ADS)

    Pontzen, Andrew; Read, Justin I.; Teyssier, Romain; Governato, Fabio; Gualandris, Alessia; Roth, Nina; Devriendt, Julien

    2015-08-01

    Galaxies and the dark matter haloes that host them are not spherically symmetric, yet spherical symmetry is a helpful simplifying approximation for idealized calculations and analysis of observational data. The assumption leads to an exact conservation of angular momentum for every particle, making the dynamics unrealistic. But how much does that inaccuracy matter in practice for analyses of stellar distribution functions, collisionless relaxation, or dark matter core-creation? We provide a general answer to this question for a wide class of aspherical systems; specifically, we consider distribution functions that are `maximally stable', i.e. that do not evolve at first order when external potentials (which arise from baryons, large-scale tidal fields or infalling substructure) are applied. We show that a spherically symmetric analysis of such systems gives rise to the false conclusion that the density of particles in phase space is ergodic (a function of energy alone). Using this idea we are able to demonstrate that: (a) observational analyses that falsely assume spherical symmetry are made more accurate by imposing a strong prior preference for near-isotropic velocity dispersions in the centre of spheroids; (b) numerical simulations that use an idealized spherically symmetric setup can yield misleading results and should be avoided where possible; and (c) triaxial dark matter haloes (formed in collisionless cosmological simulations) nearly attain our maximally stable limit, but their evolution freezes out before reaching it.

  7. Exact dynamics of stochastic linear delayed systems: Application to spatiotemporal coordination of comoving agents

    NASA Astrophysics Data System (ADS)

    McKetterick, Thomas John; Giuggioli, Luca

    2014-10-01

    Delayed dynamics result from finite transmission speeds of a signal in the form of energy, mass, or information. In stochastic systems the resulting lagged dynamics challenge our understanding due to the rich behavioral repertoire encompassing monotonic, oscillatory, and unstable evolution. Despite the vast literature, quantifying this rich behavior is limited by a lack of explicit analytic studies of high-dimensional stochastic delay systems. Here we fill this gap for systems governed by a linear Langevin equation of any number of delays and spatial dimensions with additive Gaussian noise. By exploiting Laplace transforms we are able to derive an exact time-dependent analytic solution of the Langevin equation. By using characteristic functionals we are able to construct the full time dependence of the multivariate probability distribution of the stochastic process as a function of the delayed and nondelayed random variables. As an application we consider interactions in animal collective movement that go beyond the traditional assumption of instantaneous alignment. We propose models for coordinated maneuvers of comoving agents applicable to recent empirical findings in pigeons and bats whereby individuals copy the heading of their neighbors with some delay. We highlight possible strategies that individual pairs may adopt to reduce the variance in their velocity difference and/or in their spatial separation. We also show that a minimum in the variance of the spatial separation at long times can be achieved with certain ratios of measurement to reaction delay.

  8. Study on technology of double parallel-joints coordinate measuring machine

    NASA Astrophysics Data System (ADS)

    Xia, Guisuo; Liao, Cheng; Yu, Runqiao; Fu, Yanjun

    2013-10-01

    The research of the high accuracy coordinate measuring machine is now playing a more and more considerable role in heightening the technical level of equipment manufacturing industry. With reference to the characteristics of foreign ScanMax coordinate measuring machine, this paper introduces the development of a double parallel-joint coordinate measuring machine with our own dependent intellectual property. This paper details the structural design, the calibration method and the evaluation for the uncertainty measurement of a prototype. The prototype has several advantages when compared with foreign instruments: first, decrease of Abbe error; second, enlargement of the measuring range; third, improvement of the rigidity of the instrument. The measurement test indicates that the measurement uncertainty (when K=2) of special random distance is 10.2 μm. The double parallel-joint coordinate measuring machine studied by this paper is of great academic value and the developed prototype is highly practical and worthy of being popularized.

  9. Tortoise coordinate and Hawking effect in a dynamical Kerr black hole

    NASA Astrophysics Data System (ADS)

    Yang, Jian; Zhao, Zheng; Liu, Wenbiao

    2011-02-01

    Hawking effect from a dynamical Kerr black hole is investigated using the improved Damour-Ruffini method with a new tortoise coordinate transformation. Hawking temperature of the black hole can be obtained point by point at the event horizon. It is found that Hawking temperatures of different points on the surface are different. Moreover, the temperature does not turn to zero while the dynamical black hole turns to an extreme one.

  10. Motor learning of novel dynamics is not represented in a single global coordinate system: evaluation of mixed coordinate representations and local learning

    PubMed Central

    Franklin, David W.; Flanagan, J. Randall; Wolpert, Daniel M.; Kording, Konrad

    2013-01-01

    Successful motor performance requires the ability to adapt motor commands to task dynamics. A central question in movement neuroscience is how these dynamics are represented. Although it is widely assumed that dynamics (e.g., force fields) are represented in intrinsic, joint-based coordinates (Shadmehr R, Mussa-Ivaldi FA. J Neurosci 14: 3208–3224, 1994), recent evidence has questioned this proposal. Here we reexamine the representation of dynamics in two experiments. By testing generalization following changes in shoulder, elbow, or wrist configurations, the first experiment tested for extrinsic, intrinsic, or object-centered representations. No single coordinate frame accounted for the pattern of generalization. Rather, generalization patterns were better accounted for by a mixture of representations or by models that assumed local learning and graded, decaying generalization. A second experiment, in which we replicated the design of an influential study that had suggested encoding in intrinsic coordinates (Shadmehr and Mussa-Ivaldi 1994), yielded similar results. That is, we could not find evidence that dynamics are represented in a single coordinate system. Taken together, our experiments suggest that internal models do not employ a single coordinate system when generalizing and may well be represented as a mixture of coordinate systems, as a single system with local learning, or both. PMID:24353296

  11. Single camera stereo vision coordinate measurement in parts pose recognization on CMM

    NASA Astrophysics Data System (ADS)

    Wang, Chun-mei; Huang, Feng-shan; Wang, Xue-sha; Chen, Li

    2014-11-01

    In order to recognize parts' pose on Coordinate Measuring Machine (CMM) correctly and fast, based on the translation of CMM, A single camera stereo vision measurement method for feature points' 3D coordinate on the measured parts is proposed. According to the double cameras stereo vision principle, a image of the part to be measured is captured by A CCD camera, which is driven by CMM along its X or Y axis, on two different position correspondly. Thus, the part's single camera stereo vision measurement is realized with the proposed image matching method, which is based on the centroid offset of image edge, on two images of the same feature point on the part, and each feature point's 3D coordinate in the camera coordinate system can be obtained. The measuring system is set up, and the experiment is conducted. The feature point's coordinate measuring time is 1.818s, and the difference value, which is between feature points' 3D coordinate calculated with the experiment result and that measured by CMM in the machine coordinate system, is less than 0.3mm. This measuring result can meet parts' pose real-time recognization requirement on the intelligent CMM, and also show that the method proposed in this paper is feasible.

  12. Application of a virtual coordinate measuring machine for measurement uncertainty estimation of aspherical lens parameters

    NASA Astrophysics Data System (ADS)

    Küng, Alain; Meli, Felix; Nicolet, Anaïs; Thalmann, Rudolf

    2014-09-01

    Tactile ultra-precise coordinate measuring machines (CMMs) are very attractive for accurately measuring optical components with high slopes, such as aspheres. The METAS µ-CMM, which exhibits a single point measurement repeatability of a few nanometres, is routinely used for measurement services of microparts, including optical lenses. However, estimating the measurement uncertainty is very demanding. Because of the many combined influencing factors, an analytic determination of the uncertainty of parameters that are obtained by numerical fitting of the measured surface points is almost impossible. The application of numerical simulation (Monte Carlo methods) using a parametric fitting algorithm coupled with a virtual CMM based on a realistic model of the machine errors offers an ideal solution to this complex problem: to each measurement data point, a simulated measurement variation calculated from the numerical model of the METAS µ-CMM is added. Repeated several hundred times, these virtual measurements deliver the statistical data for calculating the probability density function, and thus the measurement uncertainty for each parameter. Additionally, the eventual cross-correlation between parameters can be analyzed. This method can be applied for the calibration and uncertainty estimation of any parameter of the equation representing a geometric element. In this article, we present the numerical simulation model of the METAS µ-CMM and the application of a Monte Carlo method for the uncertainty estimation of measured asphere parameters.

  13. Dynamic indocyanine green angiography measurements

    NASA Astrophysics Data System (ADS)

    Holmes, Timothy; Invernizzi, Alessandro; Larkin, Sean; Staurenghi, Giovanni

    2012-11-01

    Dynamic indocyanine green imaging uses a scanning laser ophthalmoscope and a fluorescent dye to produce movies of the dye-filling pattern in the retina and choroid of the eye. It is used for evaluating choroidal neovascularization. Movies are examined to identify the anatomy of the pathology for planning treatment and to evaluate progression or response to treatment. The popularity of this approach is affected by the complexity and difficulty in interpreting the movies. Software algorithms were developed to produce images from the movies that are easy to interpret. A mathematical model is formulated of the flow dynamics, and a fitting algorithm is designed that solves for the flow parameters. The images provide information about flow and perfusion, including regions of change between examinations. Imaged measures include the dye fill-time, temporal dispersion, and magnitude of the dye dilution temporal curves associated with image pixels. Cases show how the software can help to identify clinically relevant anatomy such as feeder vessels, drain vessels, capillary networks, and normal choroidal draining vessels. As a potential tool for research into the character of neovascular conditions and treatments, it reveals the flow dynamics and character of the lesion. Future varieties of this methodology may be used for evaluating the success of engineered tissue transplants, surgical flaps, reconstructive surgery, breast surgery, and many other surgical applications where flow, perfusion, and vascularity of tissue are important.

  14. Evolutionary dynamics of the traveler's dilemma and minimum-effort coordination games on complex networks

    NASA Astrophysics Data System (ADS)

    Iyer, Swami; Killingback, Timothy

    2014-10-01

    The traveler's dilemma game and the minimum-effort coordination game are social dilemmas that have received significant attention resulting from the fact that the predictions of classical game theory are inconsistent with the results found when the games are studied experimentally. Moreover, both the traveler's dilemma and the minimum-effort coordination games have potentially important applications in evolutionary biology. Interestingly, standard deterministic evolutionary game theory, as represented by the replicator dynamics in a well-mixed population, is also inadequate to account for the behavior observed in these games. Here we study the evolutionary dynamics of both these games in populations with interaction patterns described by a variety of complex network topologies. We investigate the evolutionary dynamics of these games through agent-based simulations on both model and empirical networks. In particular, we study the effects of network clustering and assortativity on the evolutionary dynamics of both games. In general, we show that the evolutionary behavior of the traveler's dilemma and minimum-effort coordination games on complex networks is in good agreement with that observed experimentally. Thus, formulating the traveler's dilemma and the minimum-effort coordination games on complex networks neatly resolves the paradoxical aspects of these games.

  15. Multi-responsive coordination polymers utilising metal-stabilised, dynamic covalent imine bonds.

    PubMed

    García, Fátima; Pelss, Janis; Zuilhof, Han; Smulders, Maarten M J

    2016-07-12

    We report how the combination of dynamic covalent imine bonds and coordination bonds in a single polymer material not only imparts enhanced stability to the final polymer, but also allows the material to be sensitive to a range of stimuli, offering more fine-grained control over its properties. PMID:26879208

  16. Kinematic modeling and verification of an articulated arm coordinate measuring machine

    NASA Astrophysics Data System (ADS)

    Zhang, Huaishan; Gao, Guanbin; Wang, Wen; Na, Jing; Wu, Xing

    2016-01-01

    The articulated arm coordinate measuring machine (AACMM) is a new type of non-orthogonal coordinate measuring machine (CMM). Unlike the traditional orthogonal CMM which has three linear guides the AACMM is composed of a series of linkages connected by rotating joints. Firstly, the coordinate systems of the AACMM are established according to D-H method, the homogeneous transformation matrixes from the probe to the base of the AACMM are derived. And the graphic simulation system of the AACMM is built in Matlab, which verify the magnitude and direction of the joint angles qualitatively. Then, the data acquisition software of the AACMM is compiled by Visual C++, and there is a statistical analysis on the calculated measuring coordinates and actual coordinates, which indicates that the kinematic model of the AACMM is correct. The kinematic model provides a basis for measurement, calibration and error compensation of the AACMM.

  17. Noise and Low-Level Dynamics Can Coordinate Multicomponent Bet Hedging Mechanisms

    PubMed Central

    Garcia-Bernardo, Javier; Dunlop, Mary J.

    2015-01-01

    To counter future uncertainty, cells can stochastically express stress response mechanisms to diversify their population and hedge against stress. This approach allows a small subset of the population to survive without the prohibitive cost of constantly expressing resistance machinery at the population level. However, expression of multiple genes in concert is often needed to ensure survival, requiring coordination of infrequent events across many downstream targets. This raises the question of how cells orchestrate the timing of multiple rare events without adding cost. To investigate this, we used a stochastic model to study regulation of downstream target genes by a transcription factor. We compared several upstream regulator profiles, including constant expression, pulsatile dynamics, and noisy expression. We found that pulsatile dynamics and noise are sufficient to coordinate expression of multiple downstream genes. Notably, this is true even when fluctuations in the upstream regulator are far below the dissociation constants of the regulated genes, as with infrequently activated genes. As an example, we simulated the dynamics of the multiple antibiotic resistance activator (MarA) and 40 diverse downstream genes it regulates, determining that low-level dynamics in MarA are sufficient to coordinate expression of resistance mechanisms. We also demonstrated that noise can play a similar coordinating role. Importantly, we found that these benefits are present without a corresponding increase in the population-level cost. Therefore, our model suggests that low-level dynamics or noise in a transcription factor can coordinate expression of multiple stress response mechanisms by engaging them simultaneously without adding to the overall cost. PMID:25564865

  18. THE FEASIBILITY OF RELATING HVI COLOR MEASUREMENTS TO CIELAB COORDINATES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have begun work to demonstrate that HVI color measurements can be related to measurements made on a laboratory spectrophotometer set for measurement in the CIE L*a*b* (CIELAB) color space. The color of cotton as measured by HVI is characterized by two parameters: brightness or reflectance (Rd) a...

  19. Scaling and coordination deficits during dynamic object manipulation in Parkinson's disease

    PubMed Central

    Snider, Joseph; Lee, Dongpyo; Harrington, Deborah L.

    2014-01-01

    The ability to reach for and dynamically manipulate objects in a dexterous fashion requires scaling and coordination of arm, hand, and fingertip forces during reach and grasp components of this behavior. The neural substrates underlying dynamic object manipulation are not well understood. Insight into the role of basal ganglia-thalamocortical circuits in object manipulation can come from the study of patients with Parkinson's disease (PD). We hypothesized that scaling and coordination aspects of motor control are differentially affected by this disorder. We asked 20 PD patients and 23 age-matched control subjects to reach for, grasp, and lift virtual objects along prescribed paths. The movements were subdivided into two types, intensive (scaling) and coordinative, by detecting their underlying self-similarity. PD patients off medication were significantly impaired relative to control subjects for both aspects of movement. Intensive deficits, reduced peak speed and aperture, were seen during the reach. Coordinative deficits were observed during the reach, namely, the relative position along the trajectory at which peak speed and aperture were achieved, and during the lift, when objects tilted with respect to the gravitational axis. These results suggest that basal ganglia-thalamocortical circuits may play an important role in fine motor coordination. Dopaminergic therapy significantly improved intensive but not coordinative aspects of movements. These findings are consistent with a framework in which tonic levels of dopamine in the dorsal striatum encode the energetic cost of a movement, thereby improving intensive or scaling aspects of movement. However, repletion of brain dopamine levels does not restore finely coordinated movement. PMID:24760787

  20. Estimation of measurement accuracy of track point coordinates in nuclear photoemulsion

    NASA Astrophysics Data System (ADS)

    Shamanov, V. V.

    1995-03-01

    A simple method for an estimation of the measurement accuracy of track point coordinates in nuclear photoemulsion is described. The method is based on analysis of residual deviations of measured track points from a straight line approximating the track. Reliability of the algorithm is illustrated by Monte Carlo simulation. Examples of using the method for an estimation of the accuracy of track point coordinates measured with the microscope KSM-1 (VEB Carl Zeiss Jena) are given.

  1. Homodyne displacement measuring interferometer probe for optical coordinate measuring machine with tip and tilt sensitivity

    NASA Astrophysics Data System (ADS)

    Butler, Sam C.; Ricci, Michael A.; Wang, Chen; Wei, Qun; Ellis, Jonathan D.

    2015-10-01

    In this proceedings, we present a 3DoF (one linear, two angular) optical probe for measuring freeform optics in conjunction with an optical coordinate measuring machine (OCMM). This probe uses homodyne interferometry in a Michelson configuration and position sensing detection to simultaneously measure displacement, tip, and tilt. The goal of this work is to investigate point-to-point methods for measuring freeform optics and establish a probing methodology that can perform self-alignment with respect to the local optical surface. We present the design and preliminary benchtop validation of the probe's performance. Benchtop validation shows successful measurements with 5 nm linear and 20 μrad angular noise levels, with a 15 μm spot size. A CMOS sensor is used for visual confirmation of proper focus on measurement surface to minimize initial defocus error. A PSD detects linear horizontal and vertical displacement of the reflected beam from the measurement surface using autocollimation. In-phase and quadrature signals are measured by two photodetectors and post-processed to obtain displacement information. Periodic error caused by polarization effects and beam mixing is compensated by FPGA-based signal processing.

  2. Patterns of Horse-Rider Coordination during Endurance Race: A Dynamical System Approach

    PubMed Central

    Viry, Sylvain; Sleimen-Malkoun, Rita; Temprado, Jean-Jacques; Frances, Jean-Philippe; Berton, Eric; Laurent, Michel; Nicol, Caroline

    2013-01-01

    In riding, most biomechanical studies have focused on the description of the horse locomotion in unridden condition. In this study, we draw the prospect of how the basic principles established in inter-personal coordination by the theory of Coordination Dynamics may provide a conceptual and methodological framework for understanding the horse-rider coupling. The recent development of mobile technologies allows combined horse and rider recordings during long lasting natural events such as endurance races. Six international horse-rider dyads were thus recorded during a 120 km race by using two tri-axial accelerometers placed on the horses and riders, respectively. The analysis concentrated on their combined vertical displacements. The obtained shapes and angles of Lissajous plots together with values of relative phase between horse and rider displacements at lower reversal point allowed us to characterize four coordination patterns, reflecting the use of two riding techniques per horse's gait (trot and canter). The present study shows that the concepts, methods and tools of self-organizing dynamic system approach offer new directions for understanding horse-rider coordination. The identification of the horse-rider coupling patterns constitutes a firm basis to further study the coalition of multiple constraints that determine their emergence and their dynamics in endurance race. PMID:23940788

  3. The Virtual Teacher (VT) Paradigm: Learning New Patterns of Interpersonal Coordination Using the Human Dynamic Clamp.

    PubMed

    Kostrubiec, Viviane; Dumas, Guillaume; Zanone, Pier-Giorgio; Kelso, J A Scott

    2015-01-01

    The Virtual Teacher paradigm, a version of the Human Dynamic Clamp (HDC), is introduced into studies of learning patterns of inter-personal coordination. Combining mathematical modeling and experimentation, we investigate how the HDC may be used as a Virtual Teacher (VT) to help humans co-produce and internalize new inter-personal coordination pattern(s). Human learners produced rhythmic finger movements whilst observing a computer-driven avatar, animated by dynamic equations stemming from the well-established Haken-Kelso-Bunz (1985) and Schöner-Kelso (1988) models of coordination. We demonstrate that the VT is successful in shifting the pattern co-produced by the VT-human system toward any value (Experiment 1) and that the VT can help humans learn unstable relative phasing patterns (Experiment 2). Using transfer entropy, we find that information flow from one partner to the other increases when VT-human coordination loses stability. This suggests that variable joint performance may actually facilitate interaction, and in the long run learning. VT appears to be a promising tool for exploring basic learning processes involved in social interaction, unraveling the dynamics of information flow between interacting partners, and providing possible rehabilitation opportunities. PMID:26569608

  4. The Virtual Teacher (VT) Paradigm: Learning New Patterns of Interpersonal Coordination Using the Human Dynamic Clamp

    PubMed Central

    2015-01-01

    The Virtual Teacher paradigm, a version of the Human Dynamic Clamp (HDC), is introduced into studies of learning patterns of inter-personal coordination. Combining mathematical modeling and experimentation, we investigate how the HDC may be used as a Virtual Teacher (VT) to help humans co-produce and internalize new inter-personal coordination pattern(s). Human learners produced rhythmic finger movements whilst observing a computer-driven avatar, animated by dynamic equations stemming from the well-established Haken-Kelso-Bunz (1985) and Schöner-Kelso (1988) models of coordination. We demonstrate that the VT is successful in shifting the pattern co-produced by the VT-human system toward any value (Experiment 1) and that the VT can help humans learn unstable relative phasing patterns (Experiment 2). Using transfer entropy, we find that information flow from one partner to the other increases when VT-human coordination loses stability. This suggests that variable joint performance may actually facilitate interaction, and in the long run learning. VT appears to be a promising tool for exploring basic learning processes involved in social interaction, unraveling the dynamics of information flow between interacting partners, and providing possible rehabilitation opportunities. PMID:26569608

  5. Low Band Gap Coplanar Conjugated Molecules Featuring Dynamic Intramolecular Lewis Acid-Base Coordination.

    PubMed

    Zhu, Congzhi; Guo, Zi-Hao; Mu, Anthony U; Liu, Yi; Wheeler, Steven E; Fang, Lei

    2016-05-20

    Ladder-type conjugated molecules with a low band gap and low LUMO level were synthesized through an N-directed borylation reaction of pyrazine-derived donor-acceptor-donor precursors. The intramolecular boron-nitrogen coordination bonds played a key role in rendering the rigid and coplanar conformation of these molecules and their corresponding electronic structures. Experimental investigation and theoretical simulation revealed the dynamic nature of such coordination, which allowed for active manipulation of the optical properties of these molecules by using competing Lewis basic solvents. PMID:27096728

  6. Path planning in multi-scale ocean flows: Coordination and dynamic obstacles

    NASA Astrophysics Data System (ADS)

    Lolla, T.; Haley, P. J., Jr.; Lermusiaux, P. F. J.

    2015-10-01

    As the concurrent use of multiple autonomous vehicles in ocean missions grows, systematic control for their coordinated operation is becoming a necessity. Many ocean vehicles, especially those used in longer-range missions, possess limited operating speeds and are thus sensitive to ocean currents. Yet, the effect of currents on their trajectories is ignored by many coordination techniques. To address this issue, we first derive a rigorous level-set methodology for distance-based coordination of vehicles operating in minimum time within strong and dynamic ocean currents. The new methodology integrates ocean modeling, time-optimal level-sets and optimization schemes to predict the ocean currents, the short-term reachability sets, and the optimal headings for the desired coordination. Schemes are developed for dynamic formation control, where multiple vehicles achieve and maintain a given geometric pattern as they carry out their missions. To do so, a new score function that is suitable for regular polygon formations is obtained. Secondly, we obtain an efficient, non-intrusive technique for level-set-based time-optimal path planning in the presence of moving obstacles. The results are time-optimal path forecasts that rigorously avoid moving obstacles and sustain the desired coordination. They are exemplified and investigated for a variety of simulated ocean flows. A wind-driven double-gyre flow is used to study time-optimal dynamic formation control. Currents exiting an idealized strait or estuary are employed to explore dynamic obstacle avoidance. Finally, results are analyzed for the complex geometry and multi-scale ocean flows of the Philippine Archipelago.

  7. Optimized measurement strategy for multiple-orientation technique on coordinate-measuring machines

    NASA Astrophysics Data System (ADS)

    Kondo, Yohan; Sasajima, Kazuyuki; Osawa, Sonko; Sato, Osamu; Watanabe, Tsukasa; Komori, Masaharu

    2009-10-01

    Coordinate-measuring machines (CMMs) are widely used to measure the characteristics of various geometrical features. The measurement results using CMMs include systematic errors. To eliminate the systematic errors, the multiple-orientation technique is effective for rotationally symmetric workpieces such as cylinders or gears. However, there are Fourier components of the calibration curve that cannot be analyzed on the basis of the number of orientations; therefore, the number of orientations was set to be larger than the number of required Fourier components. Such a method takes, however, a very long time and it is difficult to maintain a stable environment during the measurement. In this paper, we propose a new measurement strategy for reducing the total number of orientations by compensating the deficient Fourier components using the measurement result with another number of orientations. When the lowest common multiple of integers m and n is set to be larger than the number of required Fourier components, the calibration result can be obtained from m + n - 1 orientations. To select m and n most efficiently, the combination should not include a common prime number. The effectiveness of the combination measurement strategy for the multiple-orientation technique was demonstrated by calibrating a multiball artifact and a gear.

  8. Two applications of small feature dimensional measurements on a coordinate measuring machine with a fiber probe

    NASA Astrophysics Data System (ADS)

    Stanfield, Eric; Muralikrishnan, Bala; Doiron, Ted; Zheng, Alan; Orandi, Shahram; Duquette, David

    2013-10-01

    This paper describes two applications of dimensional measurements performed using a contact fiber probe on a commercial coordinate measuring machine (CMM). Both examples involve artifacts that serve as reference standards and contain features in the 100 μm to 500 μm range. The first application involves measuring the spacing between features, either holes or rectangular prisms, on a cylinder that is approximately the size of a finger. The artifact, referred to as the fingerprint target, serves as a standard for verifying the performance of fingerprint scanners. The second application involves measuring the volume of small three-dimensional features such as cylinders and rectangular prisms that rise from a plate. This artifact is referred to as the volume target in this paper; these targets serve as volume standards for manufacturers and users of solder paste inspection systems. In each case, the measurement challenges presented by these artifacts are discussed and the measurand, the measurement plan, error sources, and uncertainty budget are described.

  9. Methodology for the assessment of measuring uncertainties of articulated arm coordinate measuring machines

    NASA Astrophysics Data System (ADS)

    Romdhani, Fekria; Hennebelle, François; Ge, Min; Juillion, Patrick; Coquet, Richard; François Fontaine, Jean

    2014-12-01

    Articulated Arm Coordinate Measuring Machines (AACMMs) have gradually evolved and are increasingly used in mechanical industry. At present, measurement uncertainties relating to the use of these devices are not yet well quantified. The work carried out consists of determining the measurement uncertainties of a mechanical part by an AACMM. The studies aiming to develop a model of measurement uncertainty are based on the Monte Carlo method developed in Supplement 1 of the Guide to Expression of Uncertainty in Measurement [1] but also identifying and characterizing the main sources of uncertainty. A multi-level Monte Carlo approach principle has been developed which allows for characterizing the possible evolution of the AACMM during the measurement and quantifying in a second level the uncertainty on the considered measurand. The first Monte Carlo level is the most complex and is thus divided into three sub-levels, namely characterization on the positioning error of a point, estimation of calibration errors and evaluation of fluctuations of the ‘localization point’. The global method is thus presented and results of the first sub-level are particularly developed. The main sources of uncertainty, including AACMM deformations, are exposed.

  10. Effect of muscular fatigue on fractal upper limb coordination dynamics and muscle synergies.

    PubMed

    Bueno, Diana R; Lizano, J M; Montano, L

    2015-08-01

    Rehabilitation exercises cause fatigue because tasks are repetitive. Therefore, inevitable human motion performance changes occur during the therapy. Although traditionally fatigue is considered an event that occurs in the musculoskeletal level, this paper studies whether fatigue can be regarded as context that influences lower-dimensional motor control organization and coordination at neural level. Non Negative Factorization Matrix (NNFM) and Detrended Fluctuations Analysis (DFA) are the tools used to analyze the changes in the coordination of motor function when someone is affected by fatigue. The study establishes that synergies remain fairly stable with the onset of fatigue, but the fatigue affects the dynamical coordination understood as a cognitive process. These results have been validated with 9 healthy subjects for three representative exercises for upper limb: biceps, triceps and deltoid. PMID:26737679

  11. The Effects of Shoe Traction and Obstacle Height on Lower Extremity Coordination Dynamics during Walking

    PubMed Central

    Decker, Leslie; Houser, Jeremy J.; Noble, John M.; Karst, Gregory M.; Stergiou, Nicholas

    2009-01-01

    This study aims to investigate the effects of shoe traction and obstacle height on lower extremity relative phase dynamics (analysis of intralimb coordination) during walking to better understand the mechanisms employed to avoid slippage following obstacle clearance. Ten participants walked at a self-selected pace during eight conditions: four obstacle heights (0%, 10%, 20%, and 40% of limb length) while wearing two pairs of shoes (low and high traction). A coordination analysis was used and phasing relationships between lower extremity segments were examined. The results demonstrated that significant behavioral changes were elicited under varied obstacle heights and frictional conditions. Both decreasing shoe traction and increasing obstacle height resulted in a more in-phase relationship between the interacting lower limb segments. The higher the obstacle and the lower the shoe traction, the more unstable the system became. These changes in phasing relationship and variability are indicators of alterations in coordinative behavior, which if pushed further may have lead to falling. PMID:19187929

  12. Determination of a geocentric coordinate frame for GPS measurements

    NASA Technical Reports Server (NTRS)

    Wu, S. C.; Malla, R. P.

    1988-01-01

    Two strategies for determining the offset from the geocenter for GPS measurements are considered. In the first strategy, VLBI-determined relative positions are used to fix the frame orientation and the absolute scaling, while the geocenter offset is determined from GPS measurements. In the second strategy, the absolute scaling is determined by the adopted gravitational constant of earth and the adjusted periods of GPS orbits, with the latitude being obtained from the time signature of earth rotation in the GPS measurements. The results indicate that geocentric positioning to an accuracy of a few centimeters can be achieved with just one day of precise GPS pseudorange and carrier phase data.

  13. Differing Dynamics of Intrapersonal and Interpersonal Coordination: Two-finger and Four-Finger Tapping Experiments

    PubMed Central

    Kodama, Kentaro; Furuyama, Nobuhiro; Inamura, Tetsunari

    2015-01-01

    Finger-tapping experiments were conducted to examine whether the dynamics of intrapersonal and interpersonal coordination systems can be described equally by the Haken—Kelso—Bunz model, which describes inter-limb coordination dynamics. This article reports the results of finger-tapping experiments conducted in both systems. Two within-subject factors were investigated: the phase mode and the number of fingers. In the intrapersonal experiment (Experiment 1), the participants were asked to tap, paced by a gradually hastening auditory metronome, looking at their fingers moving, using the index finger in the two finger condition, or the index and middle finger in the four-finger condition. In the interpersonal experiment (Experiment 2), pairs of participants performed the task while each participant used the outside hand, tapping with the index finger in the two finger condition, or the index and middle finger in the four-finger condition. Some results did not agree with the HKB model predictions. First, from Experiment 1, no significant difference was observed in the movement stability between the in-phase and anti-phase modes in the two finger condition. Second, from Experiment 2, no significant difference was found in the movement stability between the in-phase and anti-phase mode in the four-finger condition. From these findings, different coordination dynamics were inferred between intrapersonal and interpersonal coordination systems against prediction from the previous studies. Results were discussed according to differences between intrapersonal and interpersonal coordination systems in the availability of perceptual information and the complexity in the interaction between limbs derived from a nested structure. PMID:26070119

  14. Dynamic modeling and optimal joint torque coordination of advanced robotic systems

    NASA Astrophysics Data System (ADS)

    Kang, Hee-Jun

    The development is documented of an efficient dynamic modeling algorithm and the subsequent optimal joint input load coordination of advanced robotic systems for industrial application. A closed-form dynamic modeling algorithm for the general closed-chain robotic linkage systems is presented. The algorithm is based on the transfer of system dependence from a set of open chain Lagrangian coordinates to any desired system generalized coordinate set of the closed-chain. Three different techniques for evaluation of the kinematic closed chain constraints allow the representation of the dynamic modeling parameters in terms of system generalized coordinates and have no restriction with regard to kinematic redundancy. The total computational requirement of the closed-chain system model is largely dependent on the computation required for the dynamic model of an open kinematic chain. In order to improve computational efficiency, modification of an existing open-chain KIC based dynamic formulation is made by the introduction of the generalized augmented body concept. This algorithm allows a 44 pct. computational saving over the current optimized one (O(N4), 5995 when N = 6). As means of resolving redundancies in advanced robotic systems, local joint torque optimization is applied for effectively using actuator power while avoiding joint torque limits. The stability problem in local joint torque optimization schemes is eliminated by using fictitious dissipating forces which act in the necessary null space. The performance index representing the global torque norm is shown to be satisfactory. In addition, the resulting joint motion trajectory becomes conservative, after a transient stage, for repetitive cyclic end-effector trajectories. The effectiveness of the null space damping method is shown. The modular robot, which is built of well defined structural modules from a finite-size inventory and is controlled by one general computer system, is another class of evolving

  15. High-precision three-dimensional coordinate measurement with subwavelength-aperture-fiber point diffraction interferometer

    NASA Astrophysics Data System (ADS)

    Wang, Daodang; Xu, Yangbo; Chen, Xixi; Wang, Fumin; Kong, Ming; Zhao, Jun

    2014-11-01

    To overcome the accuracy limitation due to the machining error of standard parts in measurement system, a threedimensional coordinate measurement method with subwavelength-aperture-fiber point diffraction interferometer (PDI) is proposed, in which the high-precision measurement standard is obtained from the ideal point-diffracted spherical wavefront instead of standard components. On the basis of the phase distribution demodulated from point-diffraction interference field, high-precision three-dimensional coordinate measurement is realized with numerical iteration optimization algorithm. The subwavelength-aperture fiber is used as point-diffraction source to get precise and highenergy spherical wavefront within high aperture angle range, by which the conflict between diffraction wave angle and energy in traditional PDI can be avoided. Besides, a double-iterative method based on Levenbery-Marquardt algorithm is proposed to realize precise reconstruct three-dimensional coordinate. The analysis shows that the proposed method can reach the measurement precision better than microns within a 200×200×300 (in unit of mm) working volume. This measurement method does not rely on the initial iteration value in numerical coordinate reconstruction, and also has high measurement precision, large measuring range, fast processing speed and preferable anti-noise ability. It is of great practicality for measurement of three-dimensional coordinate and calibration of measurement system.

  16. Switching among graphic patterns is governed by oscillatory coordination dynamics: implications for understanding handwriting

    PubMed Central

    Zanone, Pier-Giorgio; Athènes, Sylvie

    2013-01-01

    Revisiting an original idea by Hollerbach (1981), previous work has established that the production of graphic shapes, assumed to be the blueprint for handwriting, is governed by the dynamics of orthogonal non-linear coupled oscillators. Such dynamics determines few stable coordination patterns, giving rise to a limited set of preferred graphic shapes, namely, four lines and four ellipsoids independent of orientation. The present study investigates the rules of switching among such graphic coordination patterns. Seven participants were required to voluntarily switch within twelve pairs of shapes presented on a graphic tablet. In line with previous theoretical and experimental work on bimanual coordination, results corroborated our hypothesis that the relative stability of the produced coordination patterns determines the time needed for switching: the transition to a more stable pattern was shorter, and inversely. Moreover, switching between patterns with the same orientation but different eccentricities was faster than with a change in orientation. Nonetheless, the switching time covaried strictly with the change in relative phase effected by the transition between two shapes, whether this implied a change in eccentricity or in orientation. These findings suggest a new operational definition of what the (motor) units or strokes of handwriting are and shed a novel light on how coarticulation and recruitment of degrees of freedom may occur in graphic skills. They also yield some leads for understanding the acquisition and the neural underpinnings of handwriting. PMID:24069014

  17. Investigation of the complex reaction coordinate of acid catalyzed amide hydrolysis from molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Zahn, Dirk

    2004-05-01

    The rate-determining step of acid catalyzed peptide hydrolysis is the nucleophilic attack of a water molecule to the carbon atom of the amide group. Therein the addition of the hydroxyl group to the amide carbon atom involves the association of a water molecule transferring one of its protons to an adjacent water molecule. The protonation of the amide nitrogen atom follows as a separate reaction step. Since the nucleophilic attack involves the breaking and formation of several bonds, the underlying reaction coordinate is rather complex. We investigate this reaction step from path sampling Car-Parrinello molecular dynamics simulations. This approach does not require the predefinition of reaction coordinates and is thus particularly suited for investigating reaction mechanisms. From our simulations the most relevant components of the reaction coordinate are elaborated. Though the C⋯O distance of the oxygen atom of the water molecule performing the nucleophilic attack and the corresponding amide carbon atom is a descriptor of the reaction progress, a complete picture of the reaction coordinate must include all three molecules taking part in the reaction. Moreover, the proton transfer is found to depend on favorable solvent configurations. Thus, also the arrangement of non-reacting, i.e. solvent water molecules needs to be considered in the reaction coordinate.

  18. Interplay of structure and vibrational dynamics in six-coordinate heme nitrosyls.

    SciTech Connect

    Silvernail, N. J.; Barabanschikov, A.; Pavlik, J. W.; Noll, B. C.; Zhao, J.; Alp, E. E.; Sturhahn, W.; Stage, J. T.; Scheidt, W. R.; Univ. of Notre Dame; Notheastern Univ.

    2007-02-02

    The isolation of two polymorphic forms of nitrosyl(1-methylimidazole)(tetra-p-fluorophenylporphinato)iron(II) provides a unique opportunity to explore the interplay of structure and vibrational dynamics in six-coordinate {l_brace}FeNO{r_brace}{sup 7} nitrosyliron porphyrinates. The two species display differing vibrational spectroscopic properties both in {nu}{sub NO} (IR) and the iron vibrational modes obtained through the use of nuclear resonance vibrational spectroscopy. Structural characterization of the two complexes has yielded extremely high-quality structures that further confirm that coordination of NO leads to ligand tilting and asymmetry in the equatorial Fe-Np bond distances. The two polymorphic structures (monoclinic and triclinic crystal systems) differ in the relative orientations of the two axial ligands and small but significant differences in coordination group bond distances. Although DFT calculations suggest that the NO/imidazole orientations should be indistinguishable, real experimental (structural and vibrational) differences between the two are found. The observed variation in the axial and equatorial Fe-N bonds is strongly correlated to the dynamics of the Fe-NO unit and other motions of iron. Other structural differences appear to have little effect on the vibrational properties of the two forms. The in-plane motions of iron in CO versus NO heme complexes illustrate distinct dynamic differences.

  19. Coordinated airborne and satellite measurements of equatorial plasma depletions

    SciTech Connect

    Weber, E.J.; Brinton, H.C.; Buchau, J.; Moore, J.G.

    1982-12-01

    A series of experiments was conducted in December 1979 to investigate the structure of plasma depletions in the low latitude, nightime ionosphere. The measurements included all sky imaging photometer (ASIP), ionosonde and amplitude scintillation observations from the AFGL Airborne Ionospheric Observatory (AIO), and in situ ion density measurements from the Atmosphere Explorer (AE-E) Bennett Ion Mass Spectrometer (BIMS). The AIO performed two flights along the Ascension Island (-18/sup 0/ MLAT) magnetic meridian: one in the southern hemisphere and one near the Ascension conjugate point in the northern hemisphere. During these flights, measurements from the AE-E satellite at 434 km altitude are compared with simultaneous remote ionospheric measurements from the AIO. Density biteouts of approximately one order of magnitude in the dominant ion O/sup +/, were mapped to lower altitudes along magnetic field lines for comparison with 6300-A and 7774-A O I airglow depletions. Because of the different airglow production mechanisms (dissociative recombination of O/sup +//sub 2/ for 6300 A and radiative recombination of O/sup +/ for 7774 A) the 6300-A depletions reflect plasma depletions near the bottomside of the F layer, while those at 7774 A are located near the peak of the layer. The O/sup +/ biteouts map directly into the 7774-A airglow depletions in the same hemisphere and also when traced into the opposite hemisphere, which indicates magnetic flux tube alignment over north-south distances of approx.2220 km. The 6300-A (bottomside) depletions are wider in longitude than the 7774-A (F-peak) depletions near the equatorward edge of the Appleton anomaly. This difference in topside and bottomside structure is used to infer large-scale structure near the anomaly and to relate this to structure, commonly observed near the magnetic equator by the ALTAIR radar.

  20. Measuring emission coordinates in a pulsar-based relativistic positioning system

    NASA Astrophysics Data System (ADS)

    Bunandar, Darius; Caveny, Scott A.; Matzner, Richard A.

    2011-11-01

    A relativistic deep space positioning system has been proposed using four or more pulsars with stable repetition rates. (Each pulsar emits pulses at a fixed repetition period in its rest frame.) The positioning system uses the fact that an event in spacetime can be fully described by emission coordinates: the proper emission time of each pulse measured at the event. The proper emission time of each pulse from four different pulsars—interpolated as necessary—provides the four spacetime coordinates of the reception event in the emission coordinate system. If more than four pulsars are available, the redundancy can improve the accuracy of the determination and/or resolve degeneracies resulting from special geometrical arrangements of the sources and the event. We introduce a robust numerical approach to measure the emission coordinates of an event in any arbitrary spacetime geometry. Our approach uses a continuous solution of the eikonal equation describing the backward null cone from the event. The pulsar proper time at the instant the null cone intersects the pulsar world line is one of the four required coordinates. The process is complete (modulo degeneracies) when four pulsar world lines have been crossed by the light cone. The numerical method is applied in two different examples: measuring emission coordinates of an event in Minkowski spacetime, using pulses from four pulsars stationary in the spacetime; and measuring emission coordinates of an event in Schwarzschild spacetime, using pulses from four pulsars freely falling toward a static black hole. These numerical simulations are merely exploratory, but with improved resolution and computational resources the method can be applied to more pertinent problems. For instance one could measure the emission coordinates, and therefore the trajectory, of the Earth.

  1. Comparison of clinical bracket point registration with 3D laser scanner and coordinate measuring machine

    PubMed Central

    Nouri, Mahtab; Farzan, Arash; Baghban, Ali Reza Akbarzadeh; Massudi, Reza

    2015-01-01

    OBJECTIVE: The aim of the present study was to assess the diagnostic value of a laser scanner developed to determine the coordinates of clinical bracket points and to compare with the results of a coordinate measuring machine (CMM). METHODS: This diagnostic experimental study was conducted on maxillary and mandibular orthodontic study casts of 18 adults with normal Class I occlusion. First, the coordinates of the bracket points were measured on all casts by a CMM. Then, the three-dimensional coordinates (X, Y, Z) of the bracket points were measured on the same casts by a 3D laser scanner designed at Shahid Beheshti University, Tehran, Iran. The validity and reliability of each system were assessed by means of intraclass correlation coefficient (ICC) and Dahlberg's formula. RESULTS: The difference between the mean dimension and the actual value for the CMM was 0.0066 mm. (95% CI: 69.98340, 69.99140). The mean difference for the laser scanner was 0.107 ± 0.133 mm (95% CI: -0.002, 0.24). In each method, differences were not significant. The ICC comparing the two methods was 0.998 for the X coordinate, and 0.996 for the Y coordinate; the mean difference for coordinates recorded in the entire arch and for each tooth was 0.616 mm. CONCLUSION: The accuracy of clinical bracket point coordinates measured by the laser scanner was equal to that of CMM. The mean difference in measurements was within the range of operator errors. PMID:25741826

  2. How to measure microtubule dynamics?

    PubMed

    Straube, Anne

    2011-01-01

    Microtubules are one of the most spectacular features in the cell: long, fairly rigid tubules that provide physical strength while at the same time serving as tracks of the intracellular transport network. In addition, they are the main constituents of the cell division machinery, and guide axonal growth and the direction of cell migration. To be able to fulfil such diverse functions, microtubules have to be arranged into suitable patterns and remodelled according to extra- and intracellular cues. Moreover, the delicate regulation of microtubule dynamics and the dynamic interactions with subcellular structures, such as kinetochores or cell adhesion sites, appear to be of crucial importance to microtubule functions. It is, therefore, important to understand microtubule dynamics and its spatiotemporal regulation at the molecular level. In this chapter, I introduce the concept of microtubule dynamics and discuss the techniques that can be employed to study microtubule dynamics in vitro and in cells, for many of which detailed protocols can be found in this volume. Microtubule dynamics is traditionally assessed by the four parameters of dynamic instability: growth and shrinkage rates, rescue and catastrophe frequencies, sometimes supplemented by pause duration. I discuss emerging issues with and alternatives to this parameter description of microtubule dynamics. PMID:21773917

  3. Coordinated rocket and satellite measurements of an auroral event. I - Satellite observations and analysis

    NASA Technical Reports Server (NTRS)

    Rees, M. H.; Stewart, A. I.; Sharp, W. E.; Hays, P. B.; Hoffman, R. A.; Brace, L. H.; Doering, J. P.; Peterson, W. K.

    1977-01-01

    Results of a coordinated auroral experiment involving the Atmosphere Explorer C satellite and a sounding rocket are reported. Auroral primary electron fluxes and neutral gas densities measured by instruments on the satellite are used in a model calculation of the thermospheric manifestation of the aurora. There is encouraging agreement between the calculated and measured electron density, electron temperature, secondary electron flux, and O I emissions at 5577 and 6300 A. A discrepancy between the calculated and the rocket-measured 3914-A emission profile is discussed in terms of experiment geometry and auroral physics. The coordinated measurements are used to infer vertical fluxes of ionization and of electron thermal energy at high altitudes

  4. Sensor Prototype to Evaluate the Contact Force in Measuring with Coordinate Measuring Arms

    PubMed Central

    Cuesta, Eduardo; Telenti, Alejandro; Patiño, Hector; González-Madruga, Daniel; Martínez-Pellitero, Susana

    2015-01-01

    This paper describes the design, development and evaluation tests of an integrated force sensor prototype for portable Coordinate Measuring Arms (CMAs or AACMMs). The development is based on the use of strain gauges located on the surface of the CMAs’ hard probe. The strain gauges as well as their cables and connectors have been protected with a custom case, made by Additive Manufacturing techniques (Polyjet 3D). The same method has been selected to manufacture an ergonomic handle that includes trigger mechanics and the electronic components required for synchronizing the trigger signal when probing occurs. The paper also describes the monitoring software that reads the signals in real time, the calibration procedure of the prototype and the validation tests oriented towards increasing knowledge of the forces employed in manual probing. Several experiments read and record the force in real time comparing different ways of probing (discontinuous and continuous contact) and measuring different types of geometric features, from single planes to exterior cylinders, cones, or spheres, through interior features. The probing force is separated into two components allowing the influence of these strategies in probe deformation to be known. The final goal of this research is to improve the probing technique, for example by using an operator training programme, allowing extra-force peaks and bad contacts to be minimized or just to avoid bad measurements. PMID:26057038

  5. Sensor Prototype to Evaluate the Contact Force in Measuring with Coordinate Measuring Arms.

    PubMed

    Cuesta, Eduardo; Telenti, Alejandro; Patiño, Hector; González-Madruga, Daniel; Martínez-Pellitero, Susana

    2015-01-01

    This paper describes the design, development and evaluation tests of an integrated force sensor prototype for portable Coordinate Measuring Arms (CMAs or AACMMs). The development is based on the use of strain gauges located on the surface of the CMAs' hard probe. The strain gauges as well as their cables and connectors have been protected with a custom case, made by Additive Manufacturing techniques (Polyjet 3D). The same method has been selected to manufacture an ergonomic handle that includes trigger mechanics and the electronic components required for synchronizing the trigger signal when probing occurs. The paper also describes the monitoring software that reads the signals in real time, the calibration procedure of the prototype and the validation tests oriented towards increasing knowledge of the forces employed in manual probing. Several experiments read and record the force in real time comparing different ways of probing (discontinuous and continuous contact) and measuring different types of geometric features, from single planes to exterior cylinders, cones, or spheres, through interior features. The probing force is separated into two components allowing the influence of these strategies in probe deformation to be known. The final goal of this research is to improve the probing technique, for example by using an operator training programme, allowing extra-force peaks and bad contacts to be minimized or just to avoid bad measurements. PMID:26057038

  6. Coordination of Flow and Traction in Migration of Amoeboid Physarum polycephalum: Model and Measurement

    NASA Astrophysics Data System (ADS)

    Lewis, Owen; Guy, Robert; Zhang, Shun; Del Alamo, Juan Carlos

    2014-11-01

    In this research, we develop a computational model of crawling Physarum based on the Immersed Boundary Method. Our model incorporates the effects of cell cytoplasm, the internal cytoskeleton and adhesions to the substrate. Cytoplasmic flows and traction stresses predicted by the model are compared to experimentally measured values obtained using simultaneous Traction Force Microscopy (TFM) and Particle Image Velocimetry (PIV). Of particular interest are stresses generated by flow and how transmission of stresses to the substrate is coordinated. We identify methods of adhesion-flow coordination which are consistent with experiments. Certain consisten coordinations are seen to be ``optimal'' with regards to crawling speed, and robust to perturbations in the extracellular environment.

  7. Students' Coordination of Geometric Reasoning and Measuring Strategies on a Fixed Perimeter Task: Developing Mathematical Understanding of Linear Measurement

    ERIC Educational Resources Information Center

    Barrett, Jeffrey E.; Clements, Douglas H.; Klanderman, David; Pennisi, Sarah-Jean; Polaki, Mokaeane V.

    2006-01-01

    This article examines students' development of levels of understanding for measurement by describing the coordination of geometric reasoning with measurement and numerical strategies. In analyzing the reasoning and argumentation of 38 Grade 2 through Grade 10 students on linear measure tasks, we found support for the application and elaboration of…

  8. Research on the multi-angle monocular coordinates measuring system for spatial points

    NASA Astrophysics Data System (ADS)

    Zhang, Yihui; Sun, Changku; Wang, Peng; Sun, Pengfei

    2015-08-01

    To improve the accuracy of coordinate measurement, the precise 3D coordinates of spatial points on the surface of the target object are needed. Based on the stereo vision measurement model, an all-around coordinates measuring system with single camera and a two-dimensional turntable is proposed. By controlling the rotation of objects in two different orientations and by the principle of relative motion, the single-CCD sensor model was imaged as a visual multi-CCD sensor model. In other words, the visual CCD sensors at different but relative positions are used to acquire coordinates information of the measured points. Considering the calibration accuracy of those two shafts affecting the accuracy of the entire system, the mathematical calibration model is built, consisting of virtual multi-CCD sensor measuring system based on the non-orthogonal shafting. The shaft and its calibration method are described in detail. The experimental result shows that the system based on the virtual multi-CCD sensor model can achieve the standard deviation of 0.44mm, and thus proves the feasibility of its multi-angle coordinates measurement for spatial points.

  9. Contact dynamics of elasto-plastic thin beams simulated via absolute nodal coordinate formulation

    NASA Astrophysics Data System (ADS)

    Wang, Qing-Tao; Tian, Qiang; Hu, Hai-Yan

    2015-12-01

    Under the frame of multibody dynamics, the contact dynamics of elasto-plastic spatial thin beams is numerically studied by using the spatial thin beam elements of absolute nodal coordinate formulation (ANCF). The internal force of the elasto-plastic spatial thin beam element is derived under the assumption that the plastic strain of the beam element depends only on its longitudinal deformation. A new body-fixed local coordinate system is introduced into the spatial thin beam element of ANCF for efficient contact detection in the contact dynamics simulation. The linear isotropic hardening constitutive law is used to describe the elasto-plastic deformation of beam material, and the classical return mapping algorithm is adopted to evaluate the plastic strains. A multi-zone contact approach of thin beams previously proposed by the authors is also introduced to detect the multiple contact zones of beams accurately, and the penalty method is used to compute the normal contact force of thin beams in contact. Four numerical examples are given to demonstrate the applicability and effectiveness of the proposed elasto-plastic spatial thin beam element of ANCF for flexible multibody system dynamics.

  10. Contact dynamics of elasto-plastic thin beams simulated via absolute nodal coordinate formulation

    NASA Astrophysics Data System (ADS)

    Wang, Qing-Tao; Tian, Qiang; Hu, Hai-Yan

    2016-06-01

    Under the frame of multibody dynamics, the contact dynamics of elasto-plastic spatial thin beams is numerically studied by using the spatial thin beam elements of absolute nodal coordinate formulation (ANCF). The internal force of the elasto-plastic spatial thin beam element is derived under the assumption that the plastic strain of the beam element depends only on its longitudinal deformation. A new body-fixed local coordinate system is introduced into the spatial thin beam element of ANCF for efficient contact detection in the contact dynamics simulation. The linear isotropic hardening constitutive law is used to describe the elasto-plastic deformation of beam material, and the classical return mapping algorithm is adopted to evaluate the plastic strains. A multi-zone contact approach of thin beams previously proposed by the authors is also introduced to detect the multiple contact zones of beams accurately, and the penalty method is used to compute the normal contact force of thin beams in contact. Four numerical examples are given to demonstrate the applicability and effectiveness of the proposed elasto-plastic spatial thin beam element of ANCF for flexible multibody system dynamics.

  11. Setting Standards at the Forefront of Delivery System Reform: Aligning Care Coordination Quality Measures for Multiple Chronic Conditions

    PubMed Central

    DuGoff, Eva H.; Dy, Sydney; Giovannetti, Erin R.; Leff, Bruce; Boyd, Cynthia M.

    2015-01-01

    The primary study objective is to assess how three major health reform care coordination initiatives (Accountable Care Organizations, Independence at Home, and Community-based Care Transitions) measure concepts critical to care coordination for people with multiple chronic conditions. We find that there are major differences in quality measurement across these three large and politically important programs. Quality measures currently used or proposed for these new health reform-related programs addressing care coordination primarily capture continuity of care. Other key areas of care coordination, such as care transitions, patient-centeredness, and cross-cutting care across multiple conditions are infrequently addressed. The lack of a comprehensive and consistent measure set for care coordination will pose challenges for health care providers and policymakers who seek, respectively, to provide and reward well-coordinated care. In addition, this heterogeneity in measuring care coordination quality will generate new information, but will inhibit comparisons between these care coordination programs. PMID:24004040

  12. Setting standards at the forefront of delivery system reform: aligning care coordination quality measures for multiple chronic conditions.

    PubMed

    DuGoff, Eva H; Dy, Sydney; Giovannetti, Erin R; Leff, Bruce; Boyd, Cynthia M

    2013-01-01

    The primary study objective is to assess how three major health reform care coordination initiatives (Accountable Care Organizations, Independence at Home, and Community-Based Care Transitions) measure concepts critical to care coordination for people with multiple chronic conditions. We find that there are major differences in quality measurement across these three large and politically important programs. Quality measures currently used or proposed for these new health reform-related programs addressing care coordination primarily capture continuity of care. Other key areas of care coordination, such as care transitions, patient-centeredness, and cross-cutting care across multiple conditions are infrequently addressed. The lack of a comprehensive and consistent measure set for care coordination will pose challenges for healthcare providers and policy makers who seek, respectively, to provide and reward well-coordinated care. In addition, this heterogeneity in measuring care coordination quality will generate new information, but will inhibit comparisons between these care coordination programs. PMID:24004040

  13. Determination of measurement uncertainty on coordinate measurement machines by measurement decomposition and utilization of canonical artifacts

    SciTech Connect

    Rasnick, B.; Cox, B.; Sherrill, M.

    1996-08-01

    The requirement for primary-level calibration of complex forms, e.g., gear profiles, has led to development of a method for quantifying the measurement uncertainty on the artifact being calibrated that does not rely on a transfer comparison. This method, developed jointly by National Institute of Standards and Technology (NIST) and Oak Ridge Metrology Center (ORMC) personnel, consists of breaking down the measurement method into simpler components and quantifying these components using generally accepted artifacts with low uncertainties (gage blocks, ring gages, spheres, etc.). Once quantified, these components are added vectorially according to NIST Technical Note 1297, 1994 Edition. Verification of this method can be accomplished by intercomparisons with other methods and laboratories.

  14. A practical coordinate unification method for integrated tactile-optical measuring system

    NASA Astrophysics Data System (ADS)

    Li, Feng; Peter Longstaff, Andrew; Fletcher, Simon; Myers, Alan

    2014-04-01

    To meet the requirement of both high speed and high accuracy 3D measurements for dimensional metrology, multi-sensor measuring systems have been developed to measure, analyse and reverse engineer the geometry of objects. This paper presents a new development in coordinate unification called the "centroid of spherical centres" method, which can be used instead of the traditional method which uses three datum-points to perform the geometric transformation and unification of tactile and optical sensors. The benefits of the proposed method are improved accuracy in coordinate unification and the method is used to integrate a coordinate measuring machine (CMM) and optical sensors (structured light scanning system and FaroArm laser line probe). A sphere-plate artefact is developed for data fusion of the multi-sensor system and experimental results validate the accuracy and effectiveness of this method.

  15. Research on performance evaluation of non-arm coordinate measuring machine (NACMM)

    NASA Astrophysics Data System (ADS)

    Wang, Weinong; Wei, Hengzheng; Xia, Yang

    2010-11-01

    The methods for performance evaluation of Articulated Arm Coordinate Measuring Machine (AACMM) have been published. Non-arm Coordinate Measuring Machine (NACMM) is similar with AACMM in function, and then the performance evaluation methods should be also similar. The research based on comparing the principle and error resources of the both systems, set up a new combination of the position, orientation and test number, try to locate a more reasonable procedure in evaluate the performance of NACMMs which can be comparable with ASME B89.4.22-2004, but better for find the characteristic of accuracy changing in measurement volume. The procedure is confirmed by testing of different NACMMs.

  16. Coordination, Organisation and Model-driven Approaches for Dynamic, Flexible, Robust Software and Services Engineering

    NASA Astrophysics Data System (ADS)

    Nieves, Juan Carlos; Padget, Julian; Vasconcelos, Wamberto; Staikopoulos, Athanasios; Cliffe, Owen; Dignum, Frank; Vázquez-Salceda, Javier; Clarke, Siobhán; Reed, Chris

    Enterprise systems are increasingly composed of (and even functioning as) components in a dynamic, digital ecosystem. On the one hand, this new situation requires flexible, spontaneous and opportunistic collaboration activities to be identified and established among (electronic) business parties. On the other, it demands engineering methods that are able to integrate new functionalities and behaviours into running systems composed by active, distributed, interdependent processes. Here we present a multi-level architecture that combines organisational and coordination theories with model driven development, for the implementation, deployment and management of dynamic, flexible and robust service-oriented business applications, combined with a service layer that accommodates semantic service description, fine-grained semantic service discovery and the dynamic adaptation of services to meet changing circumstances.

  17. Traffic Management Coordinator Evaluation of the Dynamic Weather Routes Concept and System

    NASA Technical Reports Server (NTRS)

    Gong, Chester

    2014-01-01

    Dynamic Weather Routes (DWR) is a weather-avoidance system for airline dispatchers and FAA traffic managers that continually searches for and advises the user of more efficient routes around convective weather. NASA and American Airlines (AA) have been conducting an operational trial of DWR since July 17, 2012. The objective of this evaluation is to assess DWR from a traffic management coordinator (TMC) perspective, using recently retired TMCs and actual DWR reroutes advisories that were rated acceptable by AA during the operational trial. Results from the evaluation showed that the primary reasons for a TMC to modify or reject airline reroute requests were related to airspace configuration. Approximately 80 percent of the reroutes evaluated required some coordination before implementation. Analysis showed TMCs approved 62 percent of the requested DWR reroutes, resulting in 57 percent of the total requested DWR time savings.

  18. Hamilton-Jacobi tunneling method for dynamical horizons in different coordinate gauges

    NASA Astrophysics Data System (ADS)

    Di Criscienzo, Roberto; Hayward, Sean A.; Nadalini, Mario; Vanzo, Luciano; Zerbini, Sergio

    2010-01-01

    Previous work on dynamical black hole instability is further elucidated within the Hamilton-Jacobi method for horizon tunneling and the reconstruction of the classical action by means of the null expansion method. Everything is based on two natural requirements, namely that the tunneling rate is an observable and therefore it must be based on invariantly defined quantities, and that coordinate systems which do not cover the horizon should not be admitted. These simple observations can help to clarify some ambiguities, like the doubling of the temperature occurring in the static case when using singular coordinates and the role, if any, of the temporal contribution of the action to the emission rate. The formalism is also applied to FRW cosmological models, where it is observed that it predicts the positivity of the temperature naturally, without further assumptions on the sign of energy.

  19. Design and verification of an ultra-precision 3D-coordinate measuring machine with parallel drives

    NASA Astrophysics Data System (ADS)

    Bos, Edwin; Moers, Ton; van Riel, Martijn

    2015-08-01

    An ultra-precision 3D coordinate measuring machine (CMM), the TriNano N100, has been developed. In our design, the workpiece is mounted on a 3D stage, which is driven by three parallel drives that are mutually orthogonal. The linear drives support the 3D stage using vacuum preloaded (VPL) air bearings, whereby each drive determines the position of the 3D stage along one translation direction only. An exactly constrained design results in highly repeatable machine behavior. Furthermore, the machine complies with the Abbé principle over its full measurement range and the application of parallel drives allows for excellent dynamic behavior. The design allows a 3D measurement uncertainty of 100 nanometers in a measurement range of 200 cubic centimeters. Verification measurements using a Gannen XP 3D tactile probing system on a spherical artifact show a standard deviation in single point repeatability of around 2 nm in each direction.

  20. Coordinate measuring method with two operation modes based on the adjustable articulated arms

    NASA Astrophysics Data System (ADS)

    Zhu, Lianqing; Li, Weixian; Pan, Zhikang; Guo, Yangkuan; Chen, Qingshan

    2014-12-01

    A coordinate measuring method with two operation modes, based on the adjustable articulated arms, is proposed to keep measurement capability in global space and improve the measurement precision in local space. The adjustable articulated arm coordinate measuring machine (AACMM) with an electromagnetic locking device can automatically switch between the all-free articulated arms operation mode and the partially bound articulated arms operation mode. In the former mode, three arms and six articulations can freely move and measure the coordinates of any point in global space. In the latter mode, the front two articulations are locked to improve the measurement precision by decreasing the importation of angle errors in the local space. A prototype of the adjustable AACMM has also been designed and developed. A mathematical model for the adjustable AACMM has been built. Theoretical analysis and numerical simulation show that the partially bound AACMM performed much better than the all-free AACMM in single point repeatability and length measurement precision in the local space. Therefore, the proposed coordinate measuring method based on the adjustable articulated arms is verified as being effective.

  1. Perspective: Insight into reaction coordinates and dynamics from the potential energy landscape

    SciTech Connect

    Wales, D. J.

    2015-04-07

    This perspective focuses on conceptual and computational aspects of the potential energy landscape framework. It has two objectives: first to summarise some key developments of the approach and second to illustrate how such techniques can be applied using a specific example that exploits knowledge of pathways. Recent developments in theory and simulation within the landscape framework are first outlined, including methods for structure prediction, analysis of global thermodynamic properties, and treatment of rare event dynamics. We then develop a connection between the kinetic transition network treatment of dynamics and a potential of mean force defined by a reaction coordinate. The effect of projection from the full configuration space to low dimensionality is illustrated for an atomic cluster. In this example, where a relatively successful structural order parameter is available, the principal change in cluster morphology is reproduced, but some details are not faithfully represented. In contrast, a profile based on configurations that correspond to the discrete path defined geometrically retains all the barriers and minima. This comparison provides insight into the physical origins of “friction” effects in low-dimensionality descriptions of dynamics based upon a reaction coordinate.

  2. Impact Loading and Locomotor-Respiratory Coordination Significantly Influence Breathing Dynamics in Running Humans

    PubMed Central

    Daley, Monica A.; Bramble, Dennis M.; Carrier, David R.

    2013-01-01

    Locomotor-respiratory coupling (LRC), phase-locking between breathing and stepping rhythms, occurs in many vertebrates. When quadrupedal mammals gallop, 1∶1 stride per breath coupling is necessitated by pronounced mechanical interactions between locomotion and ventilation. Humans show more flexibility in breathing patterns during locomotion, using LRC ratios of 2∶1, 2.5∶1, 3∶1, or 4∶1 and sometimes no coupling. Previous studies provide conflicting evidence on the mechanical significance of LRC in running humans. Some studies suggest LRC improves breathing efficiency, but others suggest LRC is mechanically insignificant because ‘step-driven flows’ (ventilatory flows attributable to step-induced forces) contribute a negligible fraction of tidal volume. Yet, although step-driven flows are brief, they cause large fluctuations in ventilatory flow. Here we test the hypothesis that running humans use LRC to minimize antagonistic effects of step-driven flows on breathing. We measured locomotor-ventilatory dynamics in 14 subjects running at a self-selected speed (2.6±0.1 ms−1) and compared breathing dynamics in their naturally ‘preferred’ and ‘avoided’ entrainment patterns. Step-driven flows occurred at 1-2X step frequency with peak magnitudes of 0.97±0.45 Ls−1 (mean ±S.D). Step-driven flows varied depending on ventilatory state (high versus low lung volume), suggesting state-dependent changes in compliance and damping of thoraco-abdominal tissues. Subjects naturally preferred LRC patterns that minimized antagonistic interactions and aligned ventilatory transitions with assistive phases of the step. Ventilatory transitions initiated in ‘preferred’ phases within the step cycle occurred 2x faster than those in ‘avoided’ phases. We hypothesize that humans coordinate breathing and locomotion to minimize antagonistic loading of respiratory muscles, reduce work of breathing and minimize rate of fatigue. Future work could address the potential

  3. Impact loading and locomotor-respiratory coordination significantly influence breathing dynamics in running humans.

    PubMed

    Daley, Monica A; Bramble, Dennis M; Carrier, David R

    2013-01-01

    Locomotor-respiratory coupling (LRC), phase-locking between breathing and stepping rhythms, occurs in many vertebrates. When quadrupedal mammals gallop, 1∶1 stride per breath coupling is necessitated by pronounced mechanical interactions between locomotion and ventilation. Humans show more flexibility in breathing patterns during locomotion, using LRC ratios of 2∶1, 2.5∶1, 3∶1, or 4∶1 and sometimes no coupling. Previous studies provide conflicting evidence on the mechanical significance of LRC in running humans. Some studies suggest LRC improves breathing efficiency, but others suggest LRC is mechanically insignificant because 'step-driven flows' (ventilatory flows attributable to step-induced forces) contribute a negligible fraction of tidal volume. Yet, although step-driven flows are brief, they cause large fluctuations in ventilatory flow. Here we test the hypothesis that running humans use LRC to minimize antagonistic effects of step-driven flows on breathing. We measured locomotor-ventilatory dynamics in 14 subjects running at a self-selected speed (2.6±0.1 ms(-1)) and compared breathing dynamics in their naturally 'preferred' and 'avoided' entrainment patterns. Step-driven flows occurred at 1-2X step frequency with peak magnitudes of 0.97±0.45 Ls(-1) (mean ±S.D). Step-driven flows varied depending on ventilatory state (high versus low lung volume), suggesting state-dependent changes in compliance and damping of thoraco-abdominal tissues. Subjects naturally preferred LRC patterns that minimized antagonistic interactions and aligned ventilatory transitions with assistive phases of the step. Ventilatory transitions initiated in 'preferred' phases within the step cycle occurred 2x faster than those in 'avoided' phases. We hypothesize that humans coordinate breathing and locomotion to minimize antagonistic loading of respiratory muscles, reduce work of breathing and minimize rate of fatigue. Future work could address the potential consequences of

  4. Tortoise Coordinates and Hawking Radiation in a Dynamical Spherically Symmetric Spacetime

    NASA Astrophysics Data System (ADS)

    Yang, Jian; Zhao, Zheng; Tian, Gui-Hua; Liu, Wen-Biao

    2009-12-01

    Hawking effect from dynamical spherical Vaidya black hole, Vaidya-Bonner black hole, and Vaidya-de Sitter black hole is investigated using the improved Damour-Ruffini method. After the new tortoise coordinate transformation in which the position r of event horizon is an undetermined function and the temperature parameter κ is an undetermined constant, the Klein-Gordon equation can be written as the standard form at the event horizon, and both r and κ can be determined automatically. Then extending the outgoing wave from outside to inside of the horizon analytically, the Hawking temperature can also be obtained automatically.

  5. Selective Adsorption of CO2 from Light Gas Mixtures Using a Structurally Dynamic Porous Coordination Polymer**

    SciTech Connect

    Kristi L. Kauffman, Jeffrey T. Culp, Andrew J. Allen, Laura Espinal, Winnie Wong-Ng, Thomas D. Brown, Angela Goodman, Mark P. Bernardo, Russel J. Pancoast, Danielle Chirdon, Christopher Matranga*

    2010-01-01

    The selective adsorption of CO{sub 2} from mixtures with N{sub 2}, CH{sub 4}, and N{sub 2}O in a dynamic porous coordination polymer (see monomer structure) was evaluated by ATR-FTIR spectroscopy, GC, and SANS. All three techniques indicate highly selective adsorption of CO{sub 2} from CO{sub 2}/CH{sub 4} and CO{sub 2}/N{sub 2} mixtures at 30 C, with no selectivity observed for the CO{sub 2}/N{sub 2}O system.

  6. Minimization of deviations of gear real tooth surfaces determined by coordinate measurements

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Kuan, C.; Wang, J.-C.; Handschuh, R. F.; Masseth, J.; Maruyama, N.

    1992-01-01

    The deviations of a gear's real tooth surface from the theoretical surface are determined by coordinate measurements at the grid of the surface. A method was developed to transform the deviations from Cartesian coordinates to those along the normal at the measurement locations. Equations are derived that relate the first order deviations with the adjustment to the manufacturing machine-tool settings. The deviations of the entire surface are minimized. The minimization is achieved by application of the least-square method for an overdetermined system of linear equations. The proposed method is illustrated with a numerical example for hypoid gear and pinion.

  7. Simultaneous determination of the free energy profile and effective dynamics along a reaction coordinate

    NASA Astrophysics Data System (ADS)

    Zhang, Jiong; Kosztin, Ioan

    2015-03-01

    Often one can gain insight into the functioning of a biomolecular system by following its dynamics along a relevant reaction coordinate (RC). A proper description of the motion along the RC requires not only the determination of the corresponding free energy profile (PMF) but also the correct identification of the underlying stochastic model. While there exist several methods for determining the PMF from fast non-equilibrium pulling processes, for simplicity it is implicitly assumed that the dynamics along the RC is a simple overdamped Brownian motion with known diffusion coefficient. However, in general, the dynamics along the RC is non-Markovian that can be modeled with a generalized Langevin equation characterized by a friction memory kernel. Here we propose and demonstrate a method that permits the simultaneous determination of both PMF and friction memory kernel from fast bi-directional (forward and time-reversed) pulling processes. As a result, one can determine whether the diffusion along the RC is normal or anomalous (e.g., subdiffusion). The proposed method provides a novel approach for identifying and characterizing the effective dynamics along a RC of a biomolecular system studied by either single-molecule force microscopy or steered molecular dynamics simulations. Computer time was provided by the University of Missouri Bioinformatics Consortium.

  8. Control of hierarchical polymer mechanics with bioinspired metal-coordination dynamics.

    PubMed

    Grindy, Scott C; Learsch, Robert; Mozhdehi, Davoud; Cheng, Jing; Barrett, Devin G; Guan, Zhibin; Messersmith, Phillip B; Holten-Andersen, Niels

    2015-12-01

    In conventional polymer materials, mechanical performance is traditionally engineered via material structure, using motifs such as polymer molecular weight, polymer branching, or block copolymer design. Here, by means of a model system of 4-arm poly(ethylene glycol) hydrogels crosslinked with multiple, kinetically distinct dynamic metal-ligand coordinate complexes, we show that polymer materials with decoupled spatial structure and mechanical performance can be designed. By tuning the relative concentration of two types of metal-ligand crosslinks, we demonstrate control over the material's mechanical hierarchy of energy-dissipating modes under dynamic mechanical loading, and therefore the ability to engineer a priori the viscoelastic properties of these materials by controlling the types of crosslinks rather than by modifying the polymer itself. This strategy to decouple material mechanics from structure is general and may inform the design of soft materials for use in complex mechanical environments. Three examples that demonstrate this are provided. PMID:26322715

  9. Bio-Inspired Composite Interfaces: Controlling Hydrogel Mechanics via Polymer-Nanoparticle Coordination Bond Dynamics

    NASA Astrophysics Data System (ADS)

    Holten-Andersen, Niels

    2015-03-01

    In soft nanocomposite materials, the effective interaction between polymer molecules and inorganic nanoparticle surfaces plays a critical role in bulk mechanical properties. However, controlling these interfacial interactions remains a challenge. Inspired by the adhesive chemistry in mussel threads, we present a novel approach to control composite mechanics via polymer-particle interfacial dynamics; by incorporating iron oxide nanoparticles (Fe3O4 NPs) into a catechol-modified polymer network the resulting hydrogels are crosslinked via reversible coordination bonds at Fe3O4 NP surfaces thereby providing a dynamic gel network with robust self-healing properties. By studying the thermally activated composite network relaxation processes we have found that the polymer-NP binding energy can be controlled by engineering both the organic and inorganic side of the interface.

  10. Coordinated Action of Fast and Slow Reserves for Optimal Sequential and Dynamic Emergency Reserve Activation

    NASA Astrophysics Data System (ADS)

    Salkuti, Surender Reddy; Bijwe, P. R.; Abhyankar, A. R.

    2016-04-01

    This paper proposes an optimal dynamic reserve activation plan after the occurrence of an emergency situation (generator/transmission line outage, load increase or both). An optimal plan is developed to handle the emergency situation, using coordinated action of fast and slow reserves, for secure operation with minimum overall cost. This paper considers the reserves supplied by generators (spinning reserves) and loads (demand-side reserves). The optimal backing down of costly/fast reserves and bringing up of slow reserves in each sub-interval in an integrated manner is proposed. The simulation studies are performed on IEEE 30, 57 and 300 bus test systems to demonstrate the advantage of proposed integrated/dynamic reserve activation plan over the conventional/sequential approach.

  11. Control of hierarchical polymer mechanics with bioinspired metal-coordination dynamics

    PubMed Central

    Grindy, Scott C.; Learsch, Robert; Mozhdehi, Davoud; Cheng, Jing; Barrett, Devin G.; Guan, Zhibin; Messersmith, Phillip B.; Holten-Andersen, Niels

    2015-01-01

    In conventional polymer materials, mechanical performance is traditionally engineered via material structure, using motifs such as polymer molecular weight, polymer branching, or copolymer-block design1. Here, by means of a model system of 4-arm poly(ethylene glycol) hydrogels crosslinked with multiple, kinetically distinct dynamic metal-ligand coordinate complexes, we show that polymer materials with decoupled spatial structure and mechanical performance can be designed. By tuning the relative concentration of two types of metal-ligand crosslinks, we demonstrate control over the material’s mechanical hierarchy of energy-dissipating modes under dynamic mechanical loading, and therefore the ability to engineer a priori the viscoelastic properties of these materials by controlling the types of crosslinks rather than by modifying the polymer itself. This strategy to decouple material mechanics from structure may inform the design of soft materials for use in complex mechanical environments. PMID:26322715

  12. On the use of first order rotor dynamics in multiblade coordinates. [for compound helicopter

    NASA Technical Reports Server (NTRS)

    Hohenemser, K. H.; Yin, S. K.

    1974-01-01

    This paper is directed to the question of how to represent most efficiently rotor/body coupling in a linear flight dynamics analysis. Rigid body pitch, roll and vertical motions are considered for the rotor/body coupling studies. Flapping stability limits, eigenvalues, transient responses to control step inputs, to step gusts and to random gusts are determined for a hypothetical hingeless compound helicopter operating up to .8 advance ratio. Data are obtained for the basic helicopter and for the craft with two simple control feedback systems. While complete periodic system modeling is necessary for determining flapping stability limits and vibrations, constant system modeling using first order dynamics in each of the multiblade rotor coordinates was found to be adequate for rotor-craft stability and response computations.

  13. Experimental study on performance verification tests for coordinate measuring systems with optical distance sensors

    NASA Astrophysics Data System (ADS)

    Carmignato, Simone

    2009-01-01

    Optical sensors are increasingly used for dimensional and geometrical metrology. However, the lack of international standards for testing optical coordinate measuring systems is currently limiting the traceability of measurements and the easy comparison of different optical systems. This paper presents an experimental investigation on artefacts and procedures for testing coordinate measuring systems equipped with optical distance sensors. The work is aimed at contributing to the standardization of testing methods. The VDI/VDE 2617-6.2:2005 guideline, which is probably the most complete document available at the state of the art for testing systems with optical distance sensors, is examined with specific experiments. Results from the experiments are discussed, with particular reference to the tests used for determining the following characteristics: error of indication for size measurement, probing error and structural resolution. Particular attention is given to the use of artefacts alternative to gauge blocks for determining the error of indication for size measurement.

  14. GneimoSim: A Modular Internal Coordinates Molecular Dynamics Simulation Package

    PubMed Central

    Larsen, Adrien B.; Wagner, Jeffrey R.; Kandel, Saugat; Salomon-Ferrer, Romelia; Vaidehi, Nagarajan; Jain, Abhinandan

    2014-01-01

    The Generalized Newton Euler Inverse Mass Operator (GNEIMO) method is an advanced method for internal coordinates molecular dynamics (ICMD). GNEIMO includes several theoretical and algorithmic advancements that address longstanding challenges with ICMD simulations. In this paper we describe the GneimoSim ICMD software package that implements the GNEIMO method. We believe that GneimoSim is the first software package to include advanced features such as the equipartition principle derived for internal coordinates, and a method for including the Fixman potential to eliminate systematic statistical biases introduced by the use of hard constraints. Moreover, by design, GneimoSim is extensible and can be easily interfaced with third party force field packages for ICMD simulations. Currently, GneimoSim includes interfaces to LAMMPS, OpenMM, Rosetta force field calculation packages. The availability of a comprehensive Python interface to the underlying C++ classes and their methods provides a powerful and versatile mechanism for users to develop simulation scripts to configure the simulation and control the simulation flow. GneimoSim has been used extensively for studying the dynamics of protein structures, refinement of protein homology models, and for simulating large scale protein conformational changes with enhanced sampling methods. GneimoSim is not limited to proteins and can also be used for the simulation of polymeric materials. PMID:25263538

  15. Dynamics of the Earth's fluid core: implementation of a Clairaut coordinate system

    NASA Astrophysics Data System (ADS)

    Seyed-Mahmoud, B.; Moradi, A.

    2013-12-01

    If the reference state of a rotating and self gravitating fluid body is one of hydrostatic equilibrium then the figure of the body is a spheroid such that a cross sectional area parallel to the equatorial plane of the body is a circle while that parallel to a meridional plane is an ellipse. The effect of the fluid body's flattened (spheroidal) figure is small on the frequencies of the body's short-period (shorter than a few hours in the case of the Earth) normal modes. For the log-period normal modes, however, these effects must be considered. Furthermore, the body's wobble and nutation modes owe their existence to its ellipsoidal figure. In the conventional approach to computing these frequencies, an orthogonal coordinate system is usually considered. It is then necessary to have the knowledge of the derivatives of the material properties of the body, such as the density and Lamé parameters, in order to include the effects of the ellipticity in the dynamical equations. In the available Earth models, however, these derivatives are not well defined. In order to minimize the effects of these derivatives in the treatment of the dynamical problems we use a non-orthogonal (Clairaut) coordinate system. Using this approach, we compute the frequencies and displacement eigenfunctions for some of the inertial modes of a realistic spheroidal model of the Earth's fluid core and compare them to the known results for an Earth model with a homogeneous and incompressible fluid core.

  16. Dynamic measurement of bulk modulus

    NASA Technical Reports Server (NTRS)

    Dowler, W. L.; Strand, L. D.

    1979-01-01

    Technique based on measuring phase difference between microwave reference and test signals and has been used to determine change in bulk modulus of solid-fuel rocket propellants should be useful in studying other dielectric materials.

  17. Overcoming potential energy distortions in constrained internal coordinate molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Kandel, Saugat; Salomon-Ferrer, Romelia; Larsen, Adrien B.; Jain, Abhinandan; Vaidehi, Nagarajan

    2016-01-01

    The Internal Coordinate Molecular Dynamics (ICMD) method is an attractive molecular dynamics (MD) method for studying the dynamics of bonded systems such as proteins and polymers. It offers a simple venue for coarsening the dynamics model of a system at multiple hierarchical levels. For example, large scale protein dynamics can be studied using torsional dynamics, where large domains or helical structures can be treated as rigid bodies and the loops connecting them as flexible torsions. ICMD with such a dynamic model of the protein, combined with enhanced conformational sampling method such as temperature replica exchange, allows the sampling of large scale domain motion involving high energy barrier transitions. Once these large scale conformational transitions are sampled, all-torsion, or even all-atom, MD simulations can be carried out for the low energy conformations sampled via coarse grained ICMD to calculate the energetics of distinct conformations. Such hierarchical MD simulations can be carried out with standard all-atom forcefields without the need for compromising on the accuracy of the forces. Using constraints to treat bond lengths and bond angles as rigid can, however, distort the potential energy landscape of the system and reduce the number of dihedral transitions as well as conformational sampling. We present here a two-part solution to overcome such distortions of the potential energy landscape with ICMD models. To alleviate the intrinsic distortion that stems from the reduced phase space in torsional MD, we use the Fixman compensating potential. To additionally alleviate the extrinsic distortion that arises from the coupling between the dihedral angles and bond angles within a force field, we propose a hybrid ICMD method that allows the selective relaxing of bond angles. This hybrid ICMD method bridges the gap between all-atom MD and torsional MD. We demonstrate with examples that these methods together offer a solution to eliminate the potential

  18. Overcoming potential energy distortions in constrained internal coordinate molecular dynamics simulations.

    PubMed

    Kandel, Saugat; Salomon-Ferrer, Romelia; Larsen, Adrien B; Jain, Abhinandan; Vaidehi, Nagarajan

    2016-01-28

    The Internal Coordinate Molecular Dynamics (ICMD) method is an attractive molecular dynamics (MD) method for studying the dynamics of bonded systems such as proteins and polymers. It offers a simple venue for coarsening the dynamics model of a system at multiple hierarchical levels. For example, large scale protein dynamics can be studied using torsional dynamics, where large domains or helical structures can be treated as rigid bodies and the loops connecting them as flexible torsions. ICMD with such a dynamic model of the protein, combined with enhanced conformational sampling method such as temperature replica exchange, allows the sampling of large scale domain motion involving high energy barrier transitions. Once these large scale conformational transitions are sampled, all-torsion, or even all-atom, MD simulations can be carried out for the low energy conformations sampled via coarse grained ICMD to calculate the energetics of distinct conformations. Such hierarchical MD simulations can be carried out with standard all-atom forcefields without the need for compromising on the accuracy of the forces. Using constraints to treat bond lengths and bond angles as rigid can, however, distort the potential energy landscape of the system and reduce the number of dihedral transitions as well as conformational sampling. We present here a two-part solution to overcome such distortions of the potential energy landscape with ICMD models. To alleviate the intrinsic distortion that stems from the reduced phase space in torsional MD, we use the Fixman compensating potential. To additionally alleviate the extrinsic distortion that arises from the coupling between the dihedral angles and bond angles within a force field, we propose a hybrid ICMD method that allows the selective relaxing of bond angles. This hybrid ICMD method bridges the gap between all-atom MD and torsional MD. We demonstrate with examples that these methods together offer a solution to eliminate the potential

  19. Dynamic measurements of beam-pump parameters

    SciTech Connect

    Lea, J.F.; Bowen, J.F. )

    1992-02-01

    Measurements of nine electrical and mechanical parameters were made on conventional and special-geometry units during operation of beam-pump/sucker rod systems in oil and natural gas wells. All quantities were measured simultaneously and computer-recorded for a variety of pumping conditions. In this paper, using this data, the authors compared measured dynamic gearbox torques with calculated values, illustrating how calculation techniques model dynamically measured data. Calculated efficiencies indicating losses through the units from polished rod to the gearbox are shown to be necessary for adjusting gearbox torque calculations to measured values. Also, torque/speed curves are shown at the motor sheave. These data are corrected for inertial effects and plotted vs. motor manufacturers' published curves. Possibilities for future work incorporating these measurement techniques while the unit is in operation were discussed. In general, the data show how dynamically measured beam-pump data compare with conventional calculation techniques.

  20. Research on large spatial coordinate automatic measuring system based on multilateral method

    NASA Astrophysics Data System (ADS)

    Miao, Dongjing; Li, Jianshuan; Li, Lianfu; Jiang, Yuanlin; Kang, Yao; He, Mingzhao; Deng, Xiangrui

    2015-10-01

    To measure the spatial coordinate accurately and efficiently in large size range, a manipulator automatic measurement system which based on multilateral method is developed. This system is divided into two parts: The coordinate measurement subsystem is consists of four laser tracers, and the trajectory generation subsystem is composed by a manipulator and a rail. To ensure that there is no laser beam break during the measurement process, an optimization function is constructed by using the vectors between the laser tracers measuring center and the cat's eye reflector measuring center, then an orientation automatically adjust algorithm for the reflector is proposed, with this algorithm, the laser tracers are always been able to track the reflector during the entire measurement process. Finally, the proposed algorithm is validated by taking the calibration of laser tracker for instance: the actual experiment is conducted in 5m × 3m × 3.2m range, the algorithm is used to plan the orientations of the reflector corresponding to the given 24 points automatically. After improving orientations of some minority points with adverse angles, the final results are used to control the manipulator's motion. During the actual movement, there are no beam break occurs. The result shows that the proposed algorithm help the developed system to measure the spatial coordinates over a large range with efficiency.

  1. Measurements of glottal structure dynamics

    NASA Astrophysics Data System (ADS)

    Holzrichter, John F.; Ng, Lawrence C.; Burke, Gerry J.; Champagne, Nathan J.; Kallman, Jeffrey S.; Sharpe, Robert M.; Kobler, James B.; Hillman, Robert E.; Rosowski, John J.

    2005-03-01

    Low power, radarlike electromagnetic (EM) wave sensors, operating in a homodyne interferometric mode, are being used to measure tissue motions in the human vocal tract during speech. However, when these and similar sensors are used in front of the laryngeal region during voiced speech, there remains an uncertainty regarding the contributions to the sensor signal from vocal fold movements versus those from pressure induced trachea-wall movements. Several signal-source hypotheses are tested by performing experiments with a subject who had undergone tracheostomy, and who still was able to phonate when her stoma was covered (e.g., with a plastic plate). Laser-doppler motion-measurements of the subject's posterior trachea show small tissue movements, about 15 microns, that do not contribute significantly to signals from presently used EM sensors. However, signals from the anterior wall do contribute. EM sensor and air-pressure measurements, together with 3-D EM wave simulations, show that EM sensors measure movements of the vocal folds very well. The simulations show a surprisingly effective guiding of EM waves across the vocal fold membrane, which, upon glottal opening, are interrupted and reflected. These measurements are important for EM sensor applications to speech signal de-noising, vocoding, speech recognition, and diagnostics. .

  2. Dynamic Force Measurement with Strain Gauges

    ERIC Educational Resources Information Center

    Lee, Bruce E.

    1974-01-01

    Discusses the use of four strain gauges, a Wheatstone bridge, and an oscilloscope to measure forces dynamically. Included is an example of determining the centripetal force of a pendulum in a general physics laboratory. (CC)

  3. Determining material loss from the femoral stem trunnion in hip arthroplasty using a coordinate measuring machine.

    PubMed

    Bone, Martin C; Sidaginamale, Raghavendra P; Lord, James K; Scholes, Susan C; Joyce, Thomas J; Nargol, Anthony V F; Langton, David J

    2015-01-01

    In contrast to the articulating and taper surfaces of failed total hip replacements, volumetric wear analysis of trunnions is not routinely performed. Metal wear particles from the trunnion may contribute not only to the failures of metal-on-metal total hip replacements but also to all hip replacements utilising metal trunnions. A validation study was performed with the material removed in stages from the trunnions of an Exeter V40 stem, a Corail stem and an Accolade stem to simulate different magnitudes of wear. The material loss from the trunnions was measured both volumetrically with a coordinate measuring machine and gravimetrically with a high-precision balance. A cohort of 28 ex vivo trunnions was also measured using the coordinate measuring machine. The maximum error between the two methods was found to be 0.13 mm(3). This result was comparable with the coordinate measuring machine method for the taper surface (0.2 mm(3)). The ex vivo trunnions had a median wear volume of 0.14mm(3) (range: 0.04-0.28 mm(3)). This is the first study to determine the accuracy of volumetric wear measurements of trunnions by comparing against gravimetric measurements. Volumetric wear analysis of trunnions may provide additional insights into failures of modular total hip prostheses and will be performed routinely at our centre. PMID:25655956

  4. Mass properties measurement system: Dynamics and statics measurements

    NASA Technical Reports Server (NTRS)

    Doty, Keith L.

    1993-01-01

    This report presents and interprets experimental data obtained from the Mass Properties Measurement System (MPMS). Statics measurements yield the center-of-gravity of an unknown mass and dynamics measurements yield its inertia matrix. Observations of the MPMS performance has lead us to specific design criteria and an understanding of MPMS limitations.

  5. Coordinates calibration method in a robotic remanufacturing measurement system based on linear laser scanner

    NASA Astrophysics Data System (ADS)

    Shen, C. D.; Zhu, S.; Li, C.; Liang, Y. Y.

    2009-07-01

    In robotic remanufacturing measurement system, the 3D laser scanner is arranged by the robot and the object scanned is mounted on a turntable. This paper deals with the method of calibrating the relationship between the scanner coordinate and the robot Tool0 and furthermore locating the center axis of the turntable. The data of Tool0 can be directly obtained denoting its relationship with the robot base coordinate. So, the new methods of coordinate's transformation are effectively developed. Moreover some motivated experiments and optimized programs are designed for realizing process stabilization and reliability. This paper detailed explains the basic algorithm theory, practical operation instructions, the experiment data analysis, and etc. Theory deduction and experiments show the new methods are reasonable and efficient.

  6. The model and its solution's uniqueness of a portable 3D vision coordinate measuring system

    NASA Astrophysics Data System (ADS)

    Huang, Fengshan; Qian, Huifen

    2009-11-01

    The portable three-dimensional vision coordinate measuring system, which consists of a light pen, a CCD camera and a laptop computer, can be widely applied in most coordinate measuring fields especially on the industrial spots. On the light pen there are at least three point-shaped light sources (LEDs) acting as the measured control characteristic points and a touch trigger probe with a spherical stylus which is used to contact the point to be measured. The most important character of this system is that three light sources and the probe stylus are aligned in one line with known positions. In building and studying this measuring system, how to construct the system's mathematical model is the most key problem called Perspective of Three-Collinear-points Problem, which is a particular case of Perspective of Three-points Problem (P3P). On the basis of P3P and spatial analytical geometry theory, the system's mathematical model is established. What's more, it is verified that Perspective of Three-Collinear-points Problem has a unique solution. And the analytical equations of the measured point's coordinates are derived by using the system's mathematical model and the restrict condition that three light sources and the probe stylus are aligned in one line. Finally, the effectiveness of the mathematical model is confirmed by experiments.

  7. Dynamic temperature measurements with embedded optical sensors.

    SciTech Connect

    Dolan, Daniel H.,; Seagle, Christopher T; Ao, Tommy

    2013-10-01

    This report summarizes LDRD project number 151365, %5CDynamic Temperature Measurements with Embedded Optical Sensors%22. The purpose of this project was to develop an optical sensor capable of detecting modest temperature states (<1000 K) with nanosecond time resolution, a recurring diagnostic need in dynamic compression experiments at the Sandia Z machine. Gold sensors were selected because the visible re ectance spectrum of gold varies strongly with temperature. A variety of static and dynamic measurements were performed to assess re ectance changes at di erent temperatures and pressures. Using a minimal optical model for gold, a plausible connection between static calibrations and dynamic measurements was found. With re nements to the model and diagnostic upgrades, embedded gold sensors seem capable of detecting minor (<50 K) temperature changes under dynamic compression.

  8. High dynamic range charge measurements

    DOEpatents

    De Geronimo, Gianluigi

    2012-09-04

    A charge amplifier for use in radiation sensing includes an amplifier, at least one switch, and at least one capacitor. The switch selectively couples the input of the switch to one of at least two voltages. The capacitor is electrically coupled in series between the input of the amplifier and the input of the switch. The capacitor is electrically coupled to the input of the amplifier without a switch coupled therebetween. A method of measuring charge in radiation sensing includes selectively diverting charge from an input of an amplifier to an input of at least one capacitor by selectively coupling an output of the at least one capacitor to one of at least two voltages. The input of the at least one capacitor is operatively coupled to the input of the amplifier without a switch coupled therebetween. The method also includes calculating a total charge based on a sum of the amplified charge and the diverted charge.

  9. Decipher the dynamic coordination between enzymatic activity and structural modulation at focal adhesions in living cells

    NASA Astrophysics Data System (ADS)

    Lu, Shaoying; Seong, Jihye; Wang, Yi; Chang, Shiou-Chi; Eichorst, John Paul; Ouyang, Mingxing; Li, Julie Y.-S.; Chien, Shu; Wang, Yingxiao

    2014-07-01

    Focal adhesions (FAs) are dynamic subcellular structures crucial for cell adhesion, migration and differentiation. It remains an enigma how enzymatic activities in these local complexes regulate their structural remodeling in live cells. Utilizing biosensors based on fluorescence resonance energy transfer (FRET), we developed a correlative FRET imaging microscopy (CFIM) approach to quantitatively analyze the subcellular coordination between the enzymatic Src activation and the structural FA disassembly. CFIM reveals that the Src kinase activity only within the microdomain of lipid rafts at the plasma membrane is coupled with FA dynamics. FA disassembly at cell periphery was linearly dependent on this raft-localized Src activity, although cells displayed heterogeneous levels of response to stimulation. Within lipid rafts, the time delay between Src activation and FA disassembly was 1.2 min in cells seeded on low fibronectin concentration ([FN]) and 4.3 min in cells on high [FN]. CFIM further showed that the level of Src-FA coupling, as well as the time delay, was regulated by cell-matrix interactions, as a tight enzyme-structure coupling occurred in FA populations mediated by integrin αvβ3, but not in those by integrin α5β1. Therefore, different FA subpopulations have distinctive regulation mechanisms between their local kinase activity and structural FA dynamics.

  10. Standard conforming involute gear metrology using an articulated arm coordinate measuring system

    NASA Astrophysics Data System (ADS)

    Härtig, Frank; Lin, Hu; Kniel, Karin; Shi, Zhaoyao

    2012-10-01

    Standard conforming involute gear measurements were taken by a manually operating articulated arm system and the respective task-specific measurement uncertainties were estimated. User-friendly templates were developed to provide almost unambiguous and repeatable measurement results. They allow the metrologist to easily detect and gather the single measurement points according to existing guidelines and standards commonly used in gear metrology. The research activities were carried out at the Physikalisch-Technische Bundesanstalt (PTB), Germany in the Department of Coordinate Metrology. Measurements were taken on a robust and highly accurate large gear measurement standard of PTB, in the following called the gear standard. This gear standard materializes a left-hand and a right-hand gear as well as a spur gear. The 1 m outside diameter of the gear standard is similar to the gears used in wind power plants. A commercial articulated arm coordinate measuring system was used for the measurements. A high temperature stability of ±0.2 °C was provided to minimize thermal influences. The results of profile and helix measurements will be presented. This worldwide first investigation, on the basis of a calibrated involute gear standard, gives users of the articulating arm system quantitative information on a task-specific performance of a representative gear measurement.

  11. The impact of Wii Fit intervention on dynamic balance control in children with probable Developmental Coordination Disorder and balance problems.

    PubMed

    Jelsma, Dorothee; Geuze, Reint H; Mombarg, Remo; Smits-Engelsman, Bouwien C M

    2014-02-01

    The aim of this study was to examine differences in the performance of children with probable Developmental Coordination Disorder (p-DCD) and balance problems (BP) and typical developing children (TD) on a Wii Fit task and to measure the effect on balance skills after a Wii Fit intervention. Twenty-eight children with BP and 20 TD-children participated in the study. Motor performance was assessed with the Movement Assessment Battery for Children (MABC2), three subtests of the Bruininks Oseretsky Test (BOT2): Bilateral Coordination, Balance and Running Speed & Agility, and a Wii Fit ski slalom test. The TD children and half of the children in the BP group were tested before and after a 6weeks non-intervention period. All children with BP received 6weeks of Wii Fit intervention (with games other than the ski game) and were tested before and afterwards. Children with BP were less proficient than TD children in playing the Wii Fit ski slalom game. Training with the Wii Fit improved their motor performance. The improvement was significantly larger after intervention than after a period of non-intervention. Therefore the change cannot solely be attributed to spontaneous development or test-retest effect. Nearly all children enjoyed participation during the 6weeks of intervention. Our study shows that Wii Fit intervention is effective and is potentially a method to support treatment of (dynamic) balance control problems in children. PMID:24444657

  12. Coordinating two-period ordering and advertising policies in a dynamic market with stochastic demand

    NASA Astrophysics Data System (ADS)

    Wang, Junping; Wang, Shengdong; Min, Jie

    2015-03-01

    In this paper, we study the optimal two-stage advertising and ordering policies and the channel coordination issues in a supply chain composed of one manufacturer and one retailer. The manufacturer sells a short-life-cycle product through the retailer facing stochastic demand in dynamic markets characterised by price declines and product obsolescence. Following a two-period newsvendor framework, we develop two members' optimal ordering and advertising models under both the centralised and decentralised settings, and present the closed-form solutions to the developed models as well. Moreover, we design a two-period revenue-sharing contract, and develop sufficient conditions such that the channel coordination can be achieved and a win-win outcome can be guaranteed. Our analysis suggests that the centralised decision creates an incentive for the retailer to increase the advertising investments in two periods and put the purchase forward, but the decentralised decision mechanism forces the retailer to decrease the advertising investments in two periods and postpone/reduce its purchase in the first period. This phenomenon becomes more evident when demand variability is high.

  13. A Dynamical Model of Hierarchical Selection and Coordination in Speech Planning

    PubMed Central

    Tilsen, Sam

    2013-01-01

    Studies of the control of complex sequential movements have dissociated two aspects of movement planning: control over the sequential selection of movement plans, and control over the precise timing of movement execution. This distinction is particularly relevant in the production of speech: utterances contain sequentially ordered words and syllables, but articulatory movements are often executed in a non-sequential, overlapping manner with precisely coordinated relative timing. This study presents a hybrid dynamical model in which competitive activation controls selection of movement plans and coupled oscillatory systems govern coordination. The model departs from previous approaches by ascribing an important role to competitive selection of articulatory plans within a syllable. Numerical simulations show that the model reproduces a variety of speech production phenomena, such as effects of preparation and utterance composition on reaction time, and asymmetries in patterns of articulatory timing associated with onsets and codas. The model furthermore provides a unified understanding of a diverse group of phonetic and phonological phenomena which have not previously been related. PMID:23638147

  14. Dynamics of the 1054 UT March 22, 1979, substorm event - CDAW 6. [Coordinated Data Analysis Workshop

    NASA Technical Reports Server (NTRS)

    Mcpherron, R. L.; Manka, R. H.

    1985-01-01

    The Coordinated Data Analysis Workshop (CDAW 6) has the primary objective to trace the flow of energy from the solar wind through the magnetosphere to its ultimate dissipation in the ionosphere. An essential role in this energy transfer is played by magnetospheric substorms, however, details are not yet completely understood. The International Magnetospheric Study (IMS) has provided an ideal data base for the study conducted by CDAW 6. The present investigation is concerned with the 1054 UT March 22, 1979, substorm event, which had been selected for detailed examination in connection with the studies performed by the CDAW 6. The observations of this substorm are discussed, taking into account solar wind conditions, ground magnetic activity on March 22, 1979, observations at synchronous orbit, observations in the near geomagnetic tail, and the onset of the 1054 UT expansion phase. Substorm development and magnetospheric dynamics are discussed on the basis of a synthesis of the observations.

  15. Oscillatory dynamics coordinating human frontal networks in support of goal maintenance.

    PubMed

    Voytek, Bradley; Kayser, Andrew S; Badre, David; Fegen, David; Chang, Edward F; Crone, Nathan E; Parvizi, Josef; Knight, Robert T; D'Esposito, Mark

    2015-09-01

    Humans have a capacity for hierarchical cognitive control-the ability to simultaneously control immediate actions while holding more abstract goals in mind. Neuropsychological and neuroimaging evidence suggests that hierarchical cognitive control emerges from a frontal architecture whereby prefrontal cortex coordinates neural activity in the motor cortices when abstract rules are needed to govern motor outcomes. We utilized the improved temporal resolution of human intracranial electrocorticography to investigate the mechanisms by which frontal cortical oscillatory networks communicate in support of hierarchical cognitive control. Responding according to progressively more abstract rules resulted in greater frontal network theta phase encoding (4-8 Hz) and increased prefrontal local neuronal population activity (high gamma amplitude, 80-150 Hz), which predicts trial-by-trial response times. Theta phase encoding coupled with high gamma amplitude during inter-regional information encoding, suggesting that inter-regional phase encoding is a mechanism for the dynamic instantiation of complex cognitive functions by frontal cortical subnetworks. PMID:26214371

  16. Event heap: a coordination infrastructure for dynamic heterogeneous application interactions in ubiquitous computing environments

    DOEpatents

    Johanson, Bradley E.; Fox, Armando; Winograd, Terry A.; Hanrahan, Patrick M.

    2010-04-20

    An efficient and adaptive middleware infrastructure called the Event Heap system dynamically coordinates application interactions and communications in a ubiquitous computing environment, e.g., an interactive workspace, having heterogeneous software applications running on various machines and devices across different platforms. Applications exchange events via the Event Heap. Each event is characterized by a set of unordered, named fields. Events are routed by matching certain attributes in the fields. The source and target versions of each field are automatically set when an event is posted or used as a template. The Event Heap system implements a unique combination of features, both intrinsic to tuplespaces and specific to the Event Heap, including content based addressing, support for routing patterns, standard routing fields, limited data persistence, query persistence/registration, transparent communication, self-description, flexible typing, logical/physical centralization, portable client API, at most once per source first-in-first-out ordering, and modular restartability.

  17. DUVFEL PHOTOINJECTOR DYNAMICS: MEASUREMENT AND SIMULATION.

    SciTech Connect

    GRAVES, W.S.; DIMAURO, L.F.; HEESE, R.; JOHNSON, E.D.; ROSE, J.; RUDATI, J.; SHAFTAN, T.; SHEEHY, B.; YU, L.H.; DOWELL, D.H.

    2001-06-18

    The DUVFEL photoinjector consists of a 1.6 cell BNL gun IV with copper cathode, variable pulse length Ti:Sapp and solenoid magnet. The beam dynamics and the electromagnetic fields in the photoinjector have been characterized by producing a short electron beam with very low charge that is used as a field probe. Transverse beam size and divergence are measured as a function of initial RF phase and initial spot size and compared with simulations using the code HOMDYN. The electromagnetic fields used in the simulations are produced by SUPERFISH, and have been verified with RF measurements. The simulations and measurements of beam dynamics are presented.

  18. Mars 2001 Lander Mission: Measurement Synergy Through Coordinated Operations Planning And Implementation

    NASA Technical Reports Server (NTRS)

    Arvidson, R.; Bell, J. F., III; Kaplan, D.; Marshall, J.; Mishkin, A.; Saunders, S.; Smith, P.; Squyres, S.

    1999-01-01

    , together with quantitative information on material mineralogy, chemistry, and physical properties (rock textures; soil grain size and shape distributions; degree and nature of soil induration; soil magnetic properties). The calibration targets provide radiometric and mineralogical control surfaces. The magnets allow observations of magnetic phases. Patch plates are imaged to determine adhesive and abrasive properties of soils. Coordinated mission planning is crucial for optimizing the measurement synergy among the packages included on the lander. This planning has already begun through generation of multi-sol detailed operations activities. One focus has been to develop a scenario to use the arm to dig a soil trench to a depth of tens of centimeters. The activity will be monitored through use of Pancam and RAC to ensure nominal operations and to acquire data to determine subsurface physical properties (e.g., angle of repose of trench walls). Pancam and Mini-TES observations would also provide constraints on mineralogy and texture for the walls and bottom of the trench during excavation. If desired, soils excavated at depth could be deposited on the surface and Mossbauer and APXS measurements could be acquired for these materials. Soil samples from various depths would be delivered to MECA for characterization of aqueous geochemistry and physical properties of soil grains, particularly size, shape, and hardness. These physical properties would be determined by optical and atomic force microscopy. When completed, detailed information of soil properties as a function of depth would be obtained. These various data sets would constrain our understanding of whether or not there are systematic variations in soil characteristics as a function of depth. These variations might be related, for example, to evaporative moisture losses and formation of salt deposits, thereby indicating water transport processes occurred fairly recently. Many other value-added measurement scenarios are

  19. Combination of optically measured coordinates and displacements for quantitative investigation of complex objects

    NASA Astrophysics Data System (ADS)

    Andrae, Peter; Beeck, Manfred-Andreas; Jueptner, Werner P. O.; Nadeborn, Werner; Osten, Wolfgang

    1996-09-01

    Holographic interferometry makes it possible to measure high precision displacement data in the range of the wavelength of the used laser light. However, the determination of 3D- displacement vectors of objects with complex surfaces requires the measurement of 3D-object coordinates not only to consider local sensitivities but to distinguish between in-plane deformation, i.e. strains, and out-of-plane components, i.e. shears, too. To this purpose both the surface displacement and coordinates have to be combined and it is advantageous to make the data available for CAE- systems. The object surface has to be approximated analytically from the measured point cloud to generate a surface mesh. The displacement vectors can be assigned to the nodes of this surface mesh for visualization of the deformation of the object under test. They also can be compared to the results of FEM-calculations or can be used as boundary conditions for further numerical investigations. Here the 3D-object coordinates are measured in a separate topometric set-up using a modified fringe projection technique to acquire absolute phase values and a sophisticated geometrical model to map these phase data onto coordinates precisely. The determination of 3D-displacement vectors requires the measurement of several interference phase distributions for at least three independent sensitivity directions depending on the observation and illumination directions as well as the 3D-position of each measuring point. These geometric quantities have to be transformed into a reference coordinate system of the interferometric set-up in order to calculate the geometric matrix. The necessary transformation can be realized by means of a detection of object features in both data sets and a subsequent determination of the external camera orientation. This paper presents a consistent solution for the measurement and combination of shape and displacement data including their transformation into simulation systems. The

  20. 3D precision surface measurement by dynamic structured light

    NASA Astrophysics Data System (ADS)

    Franke, Ernest A.; Magee, Michael J.; Mitchell, Joseph N.; Rigney, Michael P.

    2004-02-01

    This paper describes a 3-D imaging technique developed as an internal research project at Southwest Research Institute. The technique is based on an extension of structured light methods in which a projected pattern of parallel lines is rotated over the surface to be measured. A sequence of images is captured and the surface elevation at any location can then be determined from measurements of the temporal pattern, at any point, without considering any other points on the surface. The paper describes techniques for system calibration and surface measurement based on the method of projected quadric shells. Algorithms were developed for image and signal analysis and computer programs were written to calibrate the system and to calculate 3-D coordinates of points on a measured surface. A prototype of the Dynamic Structured Light (DSL) 3-D imaging system was assembled and typical parts were measured. The design procedure was verified and used to implement several different configurations with different measurement volumes and measurement accuracy. A small-parts measurement accuracy of 32 micrometers (.0012") RMS was verified by measuring the surface of a precision-machined plane. Large aircraft control surfaces were measured with a prototype setup that provided .02" depth resolution over a 4" by 8" field of view. Measurement times are typically less than three minutes for 300,000 points. A patent application has been filed.

  1. A discussion of dynamic stability measurement techniques

    NASA Technical Reports Server (NTRS)

    Johnson, W.

    1975-01-01

    Techniques for the measurement of the dynamic stability of linear systems are discussed. Particular attention is given to an analysis of the errors in the procedures, and to methods for calculating the system damping from the data. The techniques discussed include: transient decay, moving block analysis, spectral analysis, random decrement signatures, transfer function analysis, and parameter identification methods. The special problems of rotorcraft dynamic stability testing are discussed.

  2. EB1-recruited microtubule +TIP complexes coordinate protrusion dynamics during 3D epithelial remodeling

    PubMed Central

    Gierke, Sarah; Wittmann, Torsten

    2012-01-01

    SUMMARY Background Epithelial remodeling, in which apical-basal polarized cells switch to a migratory phenotype, plays a central role in development and disease of multicellular organisms. Although dynamic microtubules (MTs) are required for directed migration on flat surfaces, how MT dynamics are controlled or contribute to epithelial remodeling in a more physiological three-dimensional (3D) environment is not understood. We use confocal live cell imaging to analyze MT function and dynamics during 3D epithelial morphogenesis and remodeling of polarized Madin-Darby canine kidney (MDCK) epithelial cells that undergo partial epithelial-to-mesenchymal transition (EMT) in response to hepatocyte growth factor (HGF). Results We find that HGF treatment increases MT growth rate before morphological changes are evident, and that large numbers of MTs grow into HGF-induced cell extensions independent of centrosome reorientation. Using lentivirus-mediated shRNA, we demonstrate that EB1, an adaptor protein that mediates recruitment of numerous other +TIP proteins to growing MT plus ends, is required for this HGF-induced MT reorganization. We further show that protrusion and adhesion dynamics are disorganized, and that vesicular trafficking to the tip of HGF-induced cell extensions is disrupted in EB1-depleted cells. Conclusions We conclude that EB1-mediated interactions with growing MTs are important to coordinate cell shape changes and directed migration into the surrounding extracellular matrix during epithelial remodeling in a physiological 3D environment. In contrast, EB1 is not required for the establishment or maintenance of apical-basal cell polarity, suggesting different functions of +TIPs and MTs in different types of cell polarity. PMID:22483942

  3. Optimization of Dynamical Decoupling Using Measurement Feedback

    NASA Astrophysics Data System (ADS)

    Uys, Hermann; Biercuk, Michael; Vandevender, Aaron; Shiga, Nobuyasu; Itano, Wayne; Bollinger, John

    2009-05-01

    We study the optimization of dynamical decoupling sequences using ^9Be^+ ions in a Penning ion trap. We artificially synthesize the noise environment the ions see to emulate a variety of physical systems. By incorporating measurement feedback with a Nelder-Mead search algorithm, our locally optimized dynamical decoupling sequences (LODD) attain an order of magnitude improved error suppression compared to known sequences in noise environments with power spectra that have sharp, high-frequency cutoffs. The technique requires no prior knowledge of the noise spectrum. This work shows that optimized dynamical decoupling will be a useful tool in suppressing qubit errors below the fault-tolerant threshold for quantum computation.

  4. Learning a single limb multijoint coordination pattern: the impact of a mechanical constraint on the coordination dynamics of learning and transfer.

    PubMed

    Buchanan, John J

    2004-05-01

    The coordination dynamics of learning and transfer were studied in a single limb multijoint task requiring rhythmic elbow and wrist motions. Participants were required to learn a continuous 90 degrees relative phase pattern between the elbow and wrist such that an angle-angle plot of elbow and wrist motion produced a circle with a diameter of 80 degrees. Joint motion was restricted to elbow and wrist flexion-extension on the sagittal plane and the to-be-learned 90 degrees relative phase pattern was always practiced with the learning arm supine. Cycling frequency was controlled by a pacing metronome set at 0.75 Hz. Issues regarding effector-independent and effector-specific transfer were addressed with three transfer conditions: (1). learning arm prone (LP), (2). non-learning arm supine (NS), and (3). non-learning arm prone (NP). Four subjects learned the required relative phase (90 degrees ) and amplitude (80 degrees ) pattern with their dominant arm and four with their non-dominant arm. The experiment produced three main findings with regard to elbow-wrist control processes: First, seven of eight participants spontaneously produced a wrist-lagging coordination pattern (wrist motion lagged elbow motion) in learning to produce a continuous relative phase pattern of 90 degrees between the elbow and wrist. The wrist-lagging pattern may emerge as a result of the central nervous system exploiting the transfer of angular momentum from the elbow to the wrist as the elbow rotates up and down. The influence of interactive torque on elbow-wrist coordination represents an important mechanical constraint on the selection of intralimb coordination strategies during learning. The transfer conditions revealed that this mechanical constraint was effector-independent with regard to ipsilateral limb transfer (LP) and contralateral limb transfer (NS and NP). Second, consistent transfer of the learned relative phase pattern across ipsilateral and contralateral conditions demonstrates

  5. The Method of Measurements of Celestial Coordinates in Wide-Field TV-Frames

    NASA Astrophysics Data System (ADS)

    Kartashova, Anna P.

    2012-06-01

    We present a method for calculations of equatorial coordinates of any point in the single frame of the wide-field TV systems. This method can be applying for the different television systems [wide-field cameras, all-sky cameras, the cameras with the hybrid TV-system (the system with coupled of the Image Intensifier) et al.]. In that system the calculations of distortions are difficult. Therefore, we devised this method which helps decrease errors (due to distortion and the electro-optical system).The method can be used for measuring of equatorial coordinates of meteor tracks under difficult conditions during the observations such as partial cloudiness, small number of stars and large distortions of the coordinate grid in the frame. These restrictions cannot be overcome by other methods. In the case of the small number of stars the present method using of the reference stars received on a series of frames during the observation period. The accuracy of the method has been estimated to be 4'-8' (for cameras with fov 50° × 40° at the CCD 720 × 576 pixels) for maximum number of reference points in the frame. The method used 3 reference points for calculation of the equatorial coordinates of the object. One can use this method if the camera was re-oriented as well. We use this method for our wide field of view cameras.

  6. Use of global positioning system measurements to determine geocentric coordinates and variations in Earth orientation

    NASA Technical Reports Server (NTRS)

    Malla, R. P.; Wu, S.-C.; Lichten, S. M.

    1993-01-01

    Geocentric tracking station coordinates and short-period Earth-orientation variations can be measured with Global Positioning System (GPS) measurements. Unless calibrated, geocentric coordinate errors and changes in Earth orientation can lead to significant deep-space tracking errors. Ground-based GPS estimates of daily and subdaily changes in Earth orientation presently show centimeter-level precision. Comparison between GPS-estimated Earth-rotation variations, which are the differences between Universal Time 1 and Universal Coordinated Time (UT1-UTC), and those calculated from ocean tide models suggests that observed subdaily variations in Earth rotation are dominated by oceanic tidal effects. Preliminary GPS estimates for the geocenter location (from a 3-week experiment) agree with independent satellite laser-ranging estimates to better than 10 cm. Covariance analysis predicts that temporal resolution of GPS estimates for Earth orientation and geocenter improves significantly when data collected from low Earth-orbiting satellites as well as from ground sites are combined. The low Earth GPS tracking data enhance the accuracy and resolution for measuring high-frequency global geodynamical signals over time scales of less than 1 day.

  7. Bioinspired dynamic inclination measurement using inertial sensors.

    PubMed

    Vikas, Vishesh; Crane, Carl

    2015-06-01

    Biologically, the vestibular feedback is critical to the ability of human body to balance in different conditions. This balancing ability inspires analysis of the reference equilibrium position in dynamic environments. The research proposes and experimentally validates the concept of equilibrium for the human body modeled as an inverted pendulum, which is instrumental in explaining why we align the body along the surface normal when standing on a surface but not on an incline, and tend to lean backward or forward on non-static surfaces e.g. accelerating or decelerating bus. This equilibrium position--the dynamic equilibrium axis--is dependent only on the acceleration of surface of contact (e.g. gravity) and acts as the reference to the orientation measurements. The research also draws design inspiration from the two human ears--symmetry and plurality of inertial sensors. The vestibular dynamic inclinometer and planar vestibular dynamic inclinometer consist of multiple (two or four) symmetrically placed accelerometers and a gyroscope. The sensors measure the angular acceleration and absolute orientation, not the change in orientation, from the reference equilibrium position and are successful in separating gravity from motion for objects moving on ground. The measurement algorithm is an analytical solution that is not time-recursive, independent of body dynamics and devoid of integration errors. The experimental results for the two sensor combinations validate the theoretically (kinematics) derived analytical solution of the measurement algorithm. PMID:25879912

  8. Predictive-model-based dynamic coordination control strategy for power-split hybrid electric bus

    NASA Astrophysics Data System (ADS)

    Zeng, Xiaohua; Yang, Nannan; Wang, Junnian; Song, Dafeng; Zhang, Nong; Shang, Mingli; Liu, Jianxin

    2015-08-01

    Parameter-matching methods and optimal control strategies of the top-selling hybrid electric vehicle (HEV), namely, power-split HEV, are widely studied. In particular, extant research on control strategy focuses on the steady-state energy management strategy to obtain better fuel economy. However, given that multi-power sources are highly coupled in power-split HEVs and influence one another during mode shifting, conducting research on dynamic coordination control strategy (DCCS) to achieve riding comfort is also important. This paper proposes a predictive-model-based DCCS. First, the dynamic model of the objective power-split HEV is built and the mode shifting process is analyzed based on the developed model to determine the reason for the system shock generated. Engine torque estimation algorithm is then designed according to the principle of the nonlinear observer, and the prediction model of the degree of shock is established based on the theory of model predictive control. Finally, the DCCS with adaptation for a complex driving cycle is realized by combining the feedback control and the predictive model. The presented DCCS is validated on the co-simulation platform of AMESim and Simulink. Results show that the shock during mode shifting is well controlled, thereby improving riding comfort.

  9. A measuring model study of a new coordinate-measuring machine based on the parallel kinematic mechanism

    NASA Astrophysics Data System (ADS)

    Liu, Dejun; Huang, Qingcheng; Che, Rensheng; Ai, Qinghui

    1999-11-01

    This paper introduces a new coordinate measuring machine (CMM) comprising a parallel kinematic mechanism with three spatial degrees of freedom and describes its structure, measuring theory and characteristics. Compared with the conventional CMM, this kind of CMM has a simple structure, a flexible probe posture, low moving errors, high stiffness and minimal deformations etc. In this paper, the measuring model of the new parallel CMM is established according to the theory of the spatial mechanics and verified by computer simulation. This research offers a theoretical basis for developing new CMMs.

  10. Solar radiation measurements from coordinated radiosonde flights during the 20th March 2015 solar eclipse

    NASA Astrophysics Data System (ADS)

    Harrison, R. Giles; Marlton, Graeme; Williams, Paul; Nicoll, Keri

    2016-04-01

    Solar radiation sensors can be carried on standard weather balloon packages and provide additional information about the atmosphere's vertical structure beyond the traditional thermodynamic measurements [1]. An interesting set of circumstances for such sensors occurs during a solar eclipse, which provides a rapidly changing solar radiation environment within the duration of a typical free balloon flight. Coordinating several launches of solar radiation measuring radiosondes brings a good likelihood of at least one being above any cloud during the maximum eclipse, allowing solar eclipse radiation measurements for comparison with theory. For the 20th March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44N, 0.94W), Lerwick (60.15N, 1.13W) and Reykjavik (64.13N, 21.90W), straddling the path of the eclipse. All three balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. These approaches, which are essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes. [1] K.A. Nicoll and R.G. Harrison, Balloon-borne disposable radiometer Rev Sci Instrum 83, 025111 (2012) doi: 10.1063/1.3685252

  11. Integrated calibration sphere and calibration step fixture for improved coordinate measurement machine calibration

    DOEpatents

    Clifford, Harry J.

    2011-03-22

    A method and apparatus for mounting a calibration sphere to a calibration fixture for Coordinate Measurement Machine (CMM) calibration and qualification is described, decreasing the time required for such qualification, thus allowing the CMM to be used more productively. A number of embodiments are disclosed that allow for new and retrofit manufacture to perform as integrated calibration sphere and calibration fixture devices. This invention renders unnecessary the removal of a calibration sphere prior to CMM measurement of calibration features on calibration fixtures, thereby greatly reducing the time spent qualifying a CMM.

  12. Changes in measured vector magnetic fields when transformed into heliographic coordinates

    NASA Technical Reports Server (NTRS)

    Hagyard, M. J.

    1987-01-01

    The changes that occur in measured magnetic fields when they are transformed into a heliographic coordinate system are investigated. To carry out this investigation, measurements of the vector magnetic field of an active region that was observed at 1/3 the solar radius from disk center are taken, and the observed field is transformed into heliographic coordinates. Differences in the calculated potential field that occur when the heliographic normal component of the field is used as the boundary condition rather than the observed line-of-sight component are also examined. The results of this analysis show: (1) that the observed fields of sunspots more closely resemble the generally accepted picture of the distribution of umbral fields if they are displayed in heliographic coordinates; (2) that the differences in the potential calculations are less than 200 G in field strength and 20 deg in field azimuth outside sunspots; and (3) that differences in the two potential calculations in the sunspot areas are no more than 400 G in field strength but range from 60 to 80 deg in field azimuth in localized umbral areas.

  13. Coordination Chemistry and Structural Dynamics of a Long and Flexible Piperazine-Derived Ligand.

    PubMed

    Hawes, Chris S; Hamilton, Sophie E; Hicks, Jamie; Knowles, Gregory P; Chaffee, Alan L; Turner, David R; Batten, Stuart R

    2016-07-01

    A long and highly flexible internally functionalized dipyridyl ligand α,α'-p-xylylenebis(1-(4-pyridylmethylene)-piper-4-azine), L, has been employed in the synthesis of a series of coordination polymer materials with Co(II), Cd(II), and Ag(I) ions. In poly-[Cd(L)(TPA)] 1 and poly-[Co(L)(IPA)], 2, (TPA = terephthalate, IPA = isophthalate) the ligand adopts a similar linear conformation to that seen in the structure of the unbound molecule and provides a long (2.6 nm) metal-metal bridging distance. Due to the mismatch of edge lengths with that provided by the carboxylate coligands, geometric distortions from the regular dia and (4,4) network geometries for 1 and 2, respectively, are observed. In poly-[Ag2(CF3SO3)2(L)], 3, the ligand coordinates through both pyridine groups and two of the four piperazine nitrogen donors, forming a high-connectivity 2-dimensional network. The compound poly-[Ag2(L)](BF4)2·2MeCN, 4, a porous 3-dimensional cds network, undergoes a fascinating and rapid single-crystal-to-single-crystal rearrangement on exchange of the acetonitrile guests for water in ambient air, forming a nonporous hydrated network poly-[Ag2(L)](BF4)2·2H2O, 5, in which the well-ordered guest water molecules mediate the rearrangement of the tetrafluoroborate anions and the framework itself through hydrogen bonding. The dynamics of the system are examined in greater detail through the preparation of a kinetic product, the dioxane-solvated species poly-[Ag2(L)](BF4)2·2C4H8O2, 6, which undergoes a slow conversion to 5 over the course of approximately 16 h, a transition which can be monitored in real time. The reverse transformation can also be observed on immersing the hydrate 5 in dioxane. The structural features and physical properties of each of the materials can be rationalized based on the flexible and multifunctional nature of the ligand molecule, as well as the coordination behavior of the chosen metal ions. PMID:27328206

  14. Measuring Dynamic Transfer Functions of Cavitating Pumps

    NASA Technical Reports Server (NTRS)

    Baun, Daniel

    2007-01-01

    A water-flow test facility has been built to enable measurement of dynamic transfer functions (DTFs) of cavitating pumps and of inducers in such pumps. Originally, the facility was intended for use in an investigation of the effects of cavitation in a rocket-engine low-pressure oxygen turbopump. The facility can also be used to measure DTFs of cavitating pumps in general

  15. Mathematical analysis of errors resulting from choice of reference frame coordinates in measuring human joint motion

    SciTech Connect

    Hollerbach, K.; Hollister, A.

    1995-02-01

    Measurements of human joint motion frequently involve the use of opto-electronic and other motion analysis systems where some type of makers are used to establish joint motion within a global reference coordinate frame. Typically, this global reference coordinate frame is chosen to be most convenient for the person carrying out the experiment in which the joint motion is measured, and Euler angles are chosen as the measure of joint motion. Results, however, may be quite arbitrary and therefore rendered meaningless if the reference frame is not properly chosen with respect to the physical joint axis. In order to make a proper choice of coordinate axes in the reference frame, one must take into consideration both the location and the orientation of die physical joint axis relative to the reference frame`s axes. In nature, joint axes can exist at any orientation and location relative to an arbitrarily chosen global reference frame. An axis that is not properly aligned with the global reference frame is therefore called an arbitrary axis. We demonstrate that errors result when measurements and calculations are made in a global reference frame that is arbitrarily placed and oriented, with little regard for the physical axis. Slight offsets of global reference frame produce significant errors in recording rotations about the joint axis. We conclude that, in order to be able to reach valid conclusions from joint motion measurements, the reference frame with respect to which all are taken must be brought to the physical axis; furthermore, one of the reference axes must be aligned with the physical axis. Any other choice of reference axes will result in misleading an often erroneous results.

  16. Handwriting measures as reflectors of executive functions among adults with Developmental Coordination Disorders (DCD)

    PubMed Central

    Rosenblum, Sara

    2013-01-01

    Planning ahead and organizational abilities in time and space are ingredients of high-level cognitive functions labeled as ‘Executive Functions’ (EF) required for daily activities such as writing or home management. EF deficits are considered a possible underlying brain mechanism involved in Developmental Coordination Disorders (DCD). The aim: of the study was to compare the handwriting process measures and the planning and organizational abilities in space and time of students with DCD with those of matched controls and to find whether handwriting measures can predict daily planning and organizational abilities among students with DCD. Method: 30 students diagnosed with DCD, between the ages of 24–41, and 30 age- and gender-matched controls participated in the study. They filled out the Handwriting Proficiency Screening Questionnaire (HPSQ) and the Adult Developmental Co-ordination Disorders Checklist (ADC). Furthermore, they copied a paragraph on a digitizer that is part of a computerized system Computerised Penmanship Evaluation Toll (ComPET). Results: Significant group differences were found for the HPSQ subscales scores as well as for the temporal and spatial measures of the paragraph copy task. Significant group differences were also found for the planning and organizational abilities in space and time as reflected through the ADC subscales. Significant medium correlations were found in both groups between the mean HPSQ time subscale and the ADC-B subscale mean score (r = 0.50/0.58, p < 0.05). Series of regression analyses indicated that two handwriting performance measures (mean HPSQ time subscale and mean stroke duration) predicted 19% of planning and organizational abilities as reflected through daily functions (ADC-B) [F(3, 54) = 38.37, β = 0.40, p < 0.0001]. Conclusion: The results support previous evidence about EF deficits as an underlying brain mechanism involved in motor coordination disorders, their significance as related to theoretical

  17. Coordinated measurements made by Sondrestrom radar and Polar Bear Ultraviolet Imager

    NASA Astrophysics Data System (ADS)

    Robinson, R.; Dabbs, T.; Vickrey, J.; Eastes, R.; del Greco, F.; Huffman, R.; Meng, C.; Daniell, R.; Strickland, D.; Vondrak, R.

    1992-03-01

    Results of coordinated experiments in which the Sondrestrom incoherent scatter radar measured the ionospheric electron density during overpasses of the Polar Bear satellite are presented. The properties of the incident electron distribution during three midnight sector auroral events over Sondre Stromfjord are determined. The incident electron flux is used to calculate the expected height profile of electron density which is compared with the simultaneous and coincident radar measurements. The results show that the derived profiles agree well with the measured profiles both in the peak electron density and the altitude of the peak. Differences between the measured and derived profiles below the peak are attributed to deviations between the actual spectral shape and the Maxwellian shape assumed in the modeling.

  18. The study of dual camera 3D coordinate vision measurement system using a special probe

    NASA Astrophysics Data System (ADS)

    Liu, Shugui; Peng, Kai; Zhang, Xuefei; Zhang, Haifeng; Huang, Fengshan

    2006-11-01

    Due to high precision and convenient operation, the vision coordinate measurement machine with one probe has become the research focus in visual industry. In general such a visual system can be setup conveniently with just one CCD camera and probe. However, the price of the system will surge up too high to accept while the top performance hardware, such as CCD camera, image captured card and etc, have to be applied in the system to obtain the high axis-oriented measurement precision. In this paper, a new dual CCD camera vision coordinate measurement system based on redundancy principle is proposed to achieve high precision by moderate price. Since two CCD cameras are placed with the angle of camera axis like about 90 degrees to build the system, two sub-systems can be built by each CCD camera and the probe. With the help of the probe the inner and outer parameters of camera are first calibrated, the system by use of redundancy technique is set up now. When axis-oriented error is eliminated within the two sub-systems, which is so large and always exits in the single camera system, the high precision measurement is obtained by the system. The result of experiment compared to that from CMM shows that the system proposed is more excellent in stableness and precision with the uncertainty beyond +/-0.1 mm in xyz orient within the distance of 2m using two common CCD cameras.

  19. Mars 2001 Lander Mission: Measurement Synergy Through Coordinated Operations Planning And Implementation

    NASA Astrophysics Data System (ADS)

    Arvidson, R.; Bell, J. F., III; Kaplan, D.; Marshall, J.; Mishkin, A.; Saunders, S.; Smith, P.; Squyres, S.

    1999-09-01

    , together with quantitative information on material mineralogy, chemistry, and physical properties (rock textures; soil grain size and shape distributions; degree and nature of soil induration; soil magnetic properties). The calibration targets provide radiometric and mineralogical control surfaces. The magnets allow observations of magnetic phases. Patch plates are imaged to determine adhesive and abrasive properties of soils. Coordinated mission planning is crucial for optimizing the measurement synergy among the packages included on the lander. This planning has already begun through generation of multi-sol detailed operations activities. One focus has been to develop a scenario to use the arm to dig a soil trench to a depth of tens of centimeters. The activity will be monitored through use of Pancam and RAC to ensure nominal operations and to acquire data to determine subsurface physical properties (e.g., angle of repose of trench walls). Pancam and Mini-TES observations would also provide constraints on mineralogy and texture for the walls and bottom of the trench during excavation. If desired, soils excavated at depth could be deposited on the surface and Mossbauer and APXS measurements could be acquired for these materials. Soil samples from various depths would be delivered to MECA for characterization of aqueous geochemistry and physical properties of soil grains, particularly size, shape, and hardness. These physical properties would be determined by optical and atomic force microscopy. When completed, detailed information of soil properties as a function of depth would be obtained. These various data sets would constrain our understanding of whether or not there are systematic variations in soil characteristics as a function of depth. These variations might be related, for example, to evaporative moisture losses and formation of salt deposits, thereby indicating water transport processes occurred fairly recently. Many other value-added measurement scenarios are

  20. Mars 2001 Lander Mission: Measurement Synergy Through Coordinated Operations Planning And Implementation

    NASA Technical Reports Server (NTRS)

    Arvidson, R.; Bell, J. F., III; Kaplan, D.; Marshall, J.; Mishkin, A.; Saunders, S.; Smith, P.; Squyres, S.

    1999-01-01

    , together with quantitative information on material mineralogy, chemistry, and physical properties (rock textures; soil grain size and shape distributions; degree and nature of soil induration; soil magnetic properties). The calibration targets provide radiometric and mineralogical control surfaces. The magnets allow observations of magnetic phases. Patch plates are imaged to determine adhesive and abrasive properties of soils. Coordinated mission planning is crucial for optimizing the measurement synergy among the packages included on the lander. This planning has already begun through generation of multi-sol detailed operations activities. One focus has been to develop a scenario to use the arm to dig a soil trench to a depth of tens of centimeters. The activity will be monitored through use of Pancam and RAC to ensure nominal operations and to acquire data to determine subsurface physical properties (e.g., angle of repose of trench walls). Pancam and Mini-TES observations would also provide constraints on mineralogy and texture for the walls and bottom of the trench during excavation. If desired, soils excavated at depth could be deposited on the surface and Mossbauer and APXS measurements could be acquired for these materials. Soil samples from various depths would be delivered to MECA for characterization of aqueous geochemistry and physical properties of soil grains, particularly size, shape, and hardness. These physical properties would be determined by optical and atomic force microscopy. When completed, detailed information of soil properties as a function of depth would be obtained. These various data sets would constrain our understanding of whether or not there are systematic variations in soil characteristics as a function of depth. These variations might be related, for example, to evaporative moisture losses and formation of salt deposits, thereby indicating water transport processes occurred fairly recently. Many other value-added measurement scenarios are

  1. Structural investigation of lanthanoid coordination: a combined XANES and molecular dynamics study.

    PubMed

    D'Angelo, Paola; Zitolo, Andrea; Migliorati, Valentina; Mancini, Giordano; Persson, Ingmar; Chillemi, Giovanni

    2009-11-01

    This is the first systematic study exploring the potentiality of the X-ray absorption near edge structure (XANES) technique as a structural tool for systems containing lanthanoid(III) ions. A quantitative analysis of the XANES spectra at the K- and L(3)-edges has been carried out for three hydrated lanthanoid(III) ions, namely, Yb, Nd, and Gd, in aqueous solution and in the isostructural trifluoromethanesulfonate salts. The structural and dynamic properties of the hydrated lanthanoid(III) ions in aqueous solution have been investigated by a combined experimental-theoretical approach employing X-ray absorption spectroscopy and molecular dynamics (MD) simulations. This method allows one to perform a quantitative analysis of the XANES spectra of ionic solutions using a proper description of the thermal and structural fluctuations. XANES spectra have been computed starting from the MD trajectory, without carrying out any minimization in the structural parameter space. A comparative K- and L(3)-edge XANES data analysis is presented, demonstrating the clear advantages of the L(3)-edge XANES analysis over the K-edge studies for structural investigations of lanthanoid compounds. The second hydration shells provide a detectable contribution to the L(3)-edge spectra while the K-edge data are insensitive to the more distant coordination spheres because of the strong damping and broadening of the signal caused by the extremely large core hole widths. The XANES technique has been found to be a new valuable tool for the structural characterization of metal complexes both in the solid and in the liquid state, especially in the presence of low symmetry. PMID:19788258

  2. Embodied economics: how bodily information shapes the social coordination dynamics of decision-making

    PubMed Central

    Oullier, Olivier; Basso, Frédéric

    2010-01-01

    To date, experiments in economics are restricted to situations in which individuals are not influenced by the physical presence of other people. In such contexts, interactions remain at an abstract level, agents guessing what another person is thinking or is about to decide based on money exchange. Physical presence and bodily signals are therefore left out of the picture. However, in real life, social interactions (involving economic decisions or not) are not solely determined by a person's inference about someone else's state-of-mind. In this essay, we argue for embodied economics: an approach to neuroeconomics that takes into account how information provided by the entire body and its coordination dynamics influences the way we make economic decisions. Considering the role of embodiment in economics—movements, posture, sensitivity to mimicry and every kind of information the body conveys—makes sense. This is what we claim in this essay which, to some extent, constitutes a plea to consider bodily interactions between agents in social (neuro)economics. PMID:20026467

  3. Learning robotic eye-arm-hand coordination from human demonstration: a coupled dynamical systems approach.

    PubMed

    Lukic, Luka; Santos-Victor, José; Billard, Aude

    2014-04-01

    We investigate the role of obstacle avoidance in visually guided reaching and grasping movements. We report on a human study in which subjects performed prehensile motion with obstacle avoidance where the position of the obstacle was systematically varied across trials. These experiments suggest that reaching with obstacle avoidance is organized in a sequential manner, where the obstacle acts as an intermediary target. Furthermore, we demonstrate that the notion of workspace travelled by the hand is embedded explicitly in a forward planning scheme, which is actively involved in detecting obstacles on the way when performing reaching. We find that the gaze proactively coordinates the pattern of eye-arm motion during obstacle avoidance. This study provides also a quantitative assessment of the coupling between the eye-arm-hand motion. We show that the coupling follows regular phase dependencies and is unaltered during obstacle avoidance. These observations provide a basis for the design of a computational model. Our controller extends the coupled dynamical systems framework and provides fast and synchronous control of the eyes, the arm and the hand within a single and compact framework, mimicking similar control system found in humans. We validate our model for visuomotor control of a humanoid robot. PMID:24570352

  4. Evolving dynamics of trading behavior based on coordination game in complex networks

    NASA Astrophysics Data System (ADS)

    Bian, Yue-tang; Xu, Lu; Li, Jin-sheng

    2016-05-01

    This work concerns the modeling of evolvement of trading behavior in stock markets. Based on the assumption of the investors' limited rationality, the evolution mechanism of trading behavior is modeled according to the investment strategy of coordination game in network, that investors are prone to imitate their neighbors' activity through comprehensive analysis on the risk dominance degree of certain investment behavior, the network topology of their relationship and its heterogeneity. We investigate by mean-field analysis and extensive simulations the evolution of investors' trading behavior in various typical networks under different risk dominance degree of investment behavior. Our results indicate that the evolution of investors' behavior is affected by the network structure of stock market and the effect of risk dominance degree of investment behavior; the stability of equilibrium states of investors' behavior dynamics is directly related with the risk dominance degree of some behavior; connectivity and heterogeneity of the network plays an important role in the evolution of the investment behavior in stock market.

  5. Coordinating Multi-Rover Systems: Evaluation Functions for Dynamic and Noisy Environments

    NASA Technical Reports Server (NTRS)

    Turner, Kagan; Agogino, Adrian

    2005-01-01

    This paper addresses the evolution of control strategies for a collective: a set of entities that collectively strives to maximize a global evaluation function that rates the performance of the full system. Directly addressing such problems by having a population of collectives and applying the evolutionary algorithm to that population is appealing, but the search space is prohibitively large in most cases. Instead, we focus on evolving control policies for each member of the collective. The fundamental issue in this approach is how to create an evaluation function for each member of the collective that is both aligned with the global evaluation function and is sensitive to the fitness changes of the member, while relatively insensitive to the fitness changes of other members. We show how to construct evaluation functions in dynamic, noisy and communication-limited collective environments. On a rover coordination problem, a control policy evolved using aligned and member-sensitive evaluations outperfoms global evaluation methods by up to 400%. More notably, in the presence of a larger number of rovers or rovers with noisy and communication limited sensors, the proposed method outperforms global evaluation by a higher percentage than in noise-free conditions with a small number of rovers.

  6. Strength and weaknesses of modeling the dynamics of mode-locked lasers by means of collective coordinates

    NASA Astrophysics Data System (ADS)

    Alsaleh, M.; Mback, C. B. L.; Tchomgo Felenou, E.; Tchofo Dinda, P.; Grelu, Ph; Porsezian, K.

    2016-07-01

    We address the efficiency of theoretical tools used in the development and optimization of mode-locked fiber lasers. Our discussion is based on the practical case of modeling the dynamics of a dispersion-managed fiber laser. One conventional approach uses discrete propagation equations, followed by the analysis of the numerical results through a collective coordinate projection. We compare the latter with our dynamical collective coordinate approach (DCCA), which combines both modeling and analysis in a compact form. We show that for single pulse dynamics, the DCCA allows a much quicker solution mapping in the space of cavity parameters than the conventional approach, along with a good accuracy. We also discuss the weaknesses of the DCCA, in particular when multiple pulsing bifurcations occur.

  7. Bio-inspired metal-coordination dynamics: A unique tool for engineering novel properties in soft matter systems

    NASA Astrophysics Data System (ADS)

    Grindy, Scott; Li, Qiaochu; Halim, Abigail; Learsch, Robert; Holten-Andersen, Niels

    2015-03-01

    In soft material systems, materials properties are generally governed by transient, dynamic interactions of many types over many hierarchal length- and time-scales. However, explicit control over these dynamics is not always possible, leaving open questions into how transient interactions can be exploited to design soft materials with unique and exceptional properties. Inspired by the adhesive chemistry and tough character of mussel byssal threads, we present several studies on both the mechanical properties of soft materials and templated crystallization kinetics to show the diverse array of materials properties that can be generated using bio-inspired metal-coordination. By studying our model systems, we can determine the explicit effects of metal-coordination dynamics on various bulk properties, further adding to the set of tools we can use to design soft material systems.

  8. Installation and Implementation of an In-Process Coordinate Measuring Machine (CMM)

    SciTech Connect

    Johnston, Derek

    2008-06-16

    This report documents the work accomplished during the installation and implementation of the in-process Coordinate Measuring Machine (CMM) in Department A. A wealth of knowledge has been gained in solving the many technical issues that delayed the partial implementation of this CMM. The work completed thus far lead to the successfully calibrated in-process CMM workstation. A great deal of current and future work has been outlined in the following pages that shall be used as a guide for the full implementation of this CMM with machining processes in Department A.

  9. Testing coordinate measuring arms with a geometric feature-based gauge: in situ field trials

    NASA Astrophysics Data System (ADS)

    Cuesta, E.; Alvarez, B. J.; Patiño, H.; Telenti, A.; Barreiro, J.

    2016-05-01

    This work describes in detail the definition of a procedure for calibrating and evaluating coordinate measuring arms (AACMMs or CMAs). CMAs are portable coordinate measuring machines that have been widely accepted in industry despite their sensitivity to the skill and experience of the operator in charge of the inspection task. The procedure proposed here is based on the use of a dimensional gauge that incorporates multiple geometric features, specifically designed for evaluating the measuring technique when CMAs are used, at company facilities (workshops or laboratories) and by the usual operators who handle these devices in their daily work. After establishing the procedure and manufacturing the feature-based gauge, the research project was complemented with diverse in situ field tests performed with the collaboration of companies that use these devices in their inspection tasks. Some of the results are presented here, not only comparing different operators but also comparing different companies. The knowledge extracted from these experiments has allowed the procedure to be validated, the defects of the methodologies currently used for in situ inspections to be detected, and substantial improvements for increasing the reliability of these portable instruments to be proposed.

  10. Real-time multicamera system for measurement of 3D coordinates by pattern projection

    NASA Astrophysics Data System (ADS)

    Sainov, Ventseslav; Stoykova, Elena; Harizanova, Jana

    2007-06-01

    The report describes a real-time pattern-projection system for measurement of 3D coordinates with simultaneous illumination and recording of four phase-shifted fringe patterns which are projected at four different wavelengths and captured by four synchronized CCD cameras. This technical solution overcomes the main drawback of the temporal phase-shifting profilometry in which the pattern acquisition is made successively in time. The work considers the use of a sinusoidal phase grating as a projection element which is made by analysis of the frequency content of the projected fringes in the Fresnel diffraction zone and by test measurements of relative 3D coordinates that are performed with interferometrically recorded sinusoidal phase gratings on holographic plates. Finally, operation of a four-wavelength profilometric system with four spatially phase-shifted at π/2 sinusoidal phase gratings illuminated with four diode lasers at wavelengths 790 nm, 810 nm, 850 nm and 910 nm is simulated and the systematical error of the profilometric measurement is evaluated.

  11. A new concept of feature-based gauge for coordinate measuring arm evaluation

    NASA Astrophysics Data System (ADS)

    Cuesta, E.; González-Madruga, D.; Alvarez, B. J.; Barreiro, J.

    2014-06-01

    Articulated arm coordinate measuring machines (AACMM or CMA) have conquered a market share in the actual dimensional metrology field, overall when their role implies the inspection of geometrical and dimensional tolerances in an accurate 3D environment for medium-size parts. However, the unavoidable fact of AACMM manual operation constrains its reliability to a great extent, avoiding rigorous evaluation and casting doubt upon the usefulness of external calibration. In this research, a dimensional gauge especially aimed at AACMM evaluation has been developed. Furthermore, the operator skill will be revealed through the use of this gauge. A set of geometrical features, some of them oriented to evaluate the operator and others the equipment, have been collected for the gauge. The proposed evaluation methodology clearly distinguishes between dimensional and geometrical tolerances (with or without datum references), whereas actual verification standards only consider the former. Next, quality indicators deduced from the measurement results are proposed in order to compare AACMM versus coordinate measuring machine (CMM) performance, assuming that CMM possess the maximum accuracy that AACMM could reach, because CMM combines maximum contact accuracy with minimum operator influence. As a result, AACMM evaluation time could be significantly reduced since this gauge allows us to perform a customized evaluation of only those specific tolerances of interest to the user.

  12. The importance of measuring dynamic visual acuity.

    PubMed

    Muzdalo, Natasa Vujko

    2013-04-01

    In their everyday life, people interact with different objects, static as well as those in motion. However, dynamic acuity is rarely checked in medical examinations, even those preceding the issue of driving license. In order for driving to be safe, good eyesight or good correction with visual aids is imperative. Beside good eyesight, drivers also have to have good reflexes and short reaction span. The aim of this study was to compare dynamic and static visual acuity in order to observe how they vary among individuals. Twenty female and male participants, 65 years of age, took part in the study and the comparison was made with the results provided by 20 20-year old participants. Dynamic acuity was tested using the Landolt-ring optotype which was simulating movement velocity of 72 km/h. T-test demonstrated the presence of a statistically significant difference between dynamic and static acuity among the participants from 62 to 68 years of age (t = 15.852; df = 39; p < 0.01). Within the same group, dynamic acuity (mean = 0.887; std. deviation = 0.297) proved to be significantly worse than static acuity (mean = 1.40; std. deviation = 0.317). By comparing the results measured within the older group of participants with those measured in the younger group, it was shown that there exists a statistically significant difference (t = 0.275; df = 58; p < 0,05) between the older and younger group in their dynamic binocular acuity with correction. Younger participants had better dynamic binocular acuity with correction (mean = 1.063; std. deviation = 0.259) than the older participants (mean = 0.884; std. deviation = 0.298). The differences between dynamic and static acuity and its degradation in the older age groups have to be taken into account when issuing driving licenses. The future of research lies within the study of correlation between the age and acuity in order that the results can be applied in practice. PMID:23837257

  13. Dynamically defined measures and equilibrium states

    NASA Astrophysics Data System (ADS)

    Werner, Ivan

    2011-12-01

    A technique of dynamically defined measures is developed and its relation to the theory of equilibrium states is shown. The technique uses Carathéodory's method and the outer measure introduced in a previous work by I. Werner [Math. Proc. Camb. Phil. Soc. 140(2), 333-347 (2006), 10.1017/S0305004105009072]. As an application, equilibrium states for contractive Markov systems [I. Werner, J. London Math. Soc. 71(1), 236-258 (2005), 10.1112/S0024610704006088] are obtained.

  14. Viscosity measurement techniques in Dissipative Particle Dynamics

    NASA Astrophysics Data System (ADS)

    Boromand, Arman; Jamali, Safa; Maia, Joao M.

    2015-11-01

    In this study two main groups of viscosity measurement techniques are used to measure the viscosity of a simple fluid using Dissipative Particle Dynamics, DPD. In the first method, a microscopic definition of the pressure tensor is used in equilibrium and out of equilibrium to measure the zero-shear viscosity and shear viscosity, respectively. In the second method, a periodic Poiseuille flow and start-up transient shear flow is used and the shear viscosity is obtained from the velocity profiles by a numerical fitting procedure. Using the standard Lees-Edward boundary condition for DPD will result in incorrect velocity profiles at high values of the dissipative parameter. Although this issue was partially addressed in Chatterjee (2007), in this work we present further modifications (Lagrangian approach) to the original LE boundary condition (Eulerian approach) that will fix the deviation from the desired shear rate at high values of the dissipative parameter and decrease the noise to signal ratios in stress measurement while increases the accessible low shear rate window. Also, the thermostat effect of the dissipative and random forces is coupled to the dynamic response of the system and affects the transport properties like the viscosity and diffusion coefficient. We investigated thoroughly the dependency of viscosity measured by both Eulerian and Lagrangian methodologies, as well as numerical fitting procedures and found that all the methods are in quantitative agreement.

  15. Dimensionality and size scaling of coordinated Ca(2+) dynamics in MIN6 β-cell clusters.

    PubMed

    Hraha, Thomas H; Bernard, Abigail B; Nguyen, Linda M; Anseth, Kristi S; Benninger, Richard K P

    2014-01-01

    Pancreatic islets of Langerhans regulate blood glucose homeostasis by the secretion of the hormone insulin. Like many neuroendocrine cells, the coupling between insulin-secreting β-cells in the islet is critical for the dynamics of hormone secretion. We have examined how this coupling architecture regulates the electrical dynamics that underlie insulin secretion by utilizing a microwell-based aggregation method to generate clusters of a β-cell line with defined sizes and dimensions. We measured the dynamics of free-calcium activity ([Ca(2+)]i) and insulin secretion and compared these measurements with a percolating network model. We observed that the coupling dimension was critical for regulating [Ca(2+)]i dynamics and insulin secretion. Three-dimensional coupling led to size-invariant suppression of [Ca(2+)]i at low glucose and robust synchronized [Ca(2+)]i oscillations at elevated glucose, whereas two-dimensional coupling showed poor suppression and less robust synchronization, with significant size-dependence. The dimension- and size-scaling of [Ca(2+)]i at high and low glucose could be accurately described with the percolating network model, using similar network connectivity. As such this could explain the fundamentally different behavior and size-scaling observed under each coupling dimension. This study highlights the dependence of proper β-cell function on the coupling architecture that will be important for developing therapeutic treatments for diabetes such as islet transplantation techniques. Furthermore, this will be vital to gain a better understanding of the general features by which cellular interactions regulate coupled multicellular systems. PMID:24411262

  16. HotEye (tm) Based Coordinate Measuring Machine for Forging Industry

    SciTech Connect

    OG Technologies

    2003-06-09

    The objective of this project is to develop a 3 dimensional measurement system for the domestic forging industry based on HotEye{trademark}. This technology will allow high definition camera to accurately image a red hot object. The project marries conventional Coordinate Measurement Machine ''CMM'' technology to HotEye{trademark} technology to permit the accurate measurement of forged parts while they are at high temperature. Being able to take such measurements will dramatically reduce the amount of scrap produced by the domestic forging industry. This industry wastes a significant amount of energy because of the high rate of scrap it produces. OGT will: (1) Develop a 3D measurement sensor head that will work on a part at a temperature up to 1,450 C with an accuracy of 0.1mm or better and with a scanning speed of less than 10 seconds for an area of 100mm x 100mm. (2) Develop a Virtual-Fixturing software package to alleviate the need of precise hard fixturing. (3) Integrate the 3D measurement sensor head and the Virtual-Fixturing software into a standard CMM, both hardware (replacing the probes) and software (data format and user interface match) so that the system can automatically perform a complete preprogrammed measurement of a hot product. (4) Test and evaluate the system in a forging facility.

  17. Multidimensional characterization of stochastic dynamical systems based on multiple perturbations and measurements.

    PubMed

    Kryvohuz, Maksym; Mukamel, Shaul

    2015-06-01

    Generalized nonlinear response theory is presented for stochastic dynamical systems. Experiments in which multiple measurements of dynamical quantities are used along with multiple perturbations of parameters of dynamical systems are described by generalized response functions (GRFs). These constitute a new type of multidimensional measures of stochastic dynamics either in the time or the frequency domains. Closed expressions for GRFs in stochastic dynamical systems are derived and compared with numerical non-equilibrium simulations. Several types of perturbations are considered: impulsive and periodic perturbations of temperature and impulsive perturbations of coordinates. The present approach can be used to study various types of stochastic processes ranging from single-molecule conformational dynamics to chemical kinetics of finite-size reactors such as biocells. PMID:26049450

  18. Multidimensional characterization of stochastic dynamical systems based on multiple perturbations and measurements

    SciTech Connect

    Kryvohuz, Maksym Mukamel, Shaul

    2015-06-07

    Generalized nonlinear response theory is presented for stochastic dynamical systems. Experiments in which multiple measurements of dynamical quantities are used along with multiple perturbations of parameters of dynamical systems are described by generalized response functions (GRFs). These constitute a new type of multidimensional measures of stochastic dynamics either in the time or the frequency domains. Closed expressions for GRFs in stochastic dynamical systems are derived and compared with numerical non-equilibrium simulations. Several types of perturbations are considered: impulsive and periodic perturbations of temperature and impulsive perturbations of coordinates. The present approach can be used to study various types of stochastic processes ranging from single-molecule conformational dynamics to chemical kinetics of finite-size reactors such as biocells.

  19. Embodiment of intersubjective time: relational dynamics as attractors in the temporal coordination of interpersonal behaviors and experiences.

    PubMed

    Laroche, Julien; Berardi, Anna Maria; Brangier, Eric

    2014-01-01

    This paper addresses the issue of "being together," and more specifically the issue of "being together in time." We provide with an integrative framework that is inspired by phenomenology, the enactive approach and dynamical systems theories. To do so, we first define embodiment as a living and lived phenomenon that emerges from agent-world coupling. We then show that embodiment is essentially dynamical and therefore we describe experiential, behavioral and brain dynamics. Both lived temporality and the temporality of the living appear to be complex, multiscale phenomena. Next we discuss embodied dynamics in the context of interpersonal interactions, and briefly review the empirical literature on between-persons temporal coordination. Overall, we propose that being together in time emerges from the relational dynamics of embodied interactions and their flexible co-regulation. PMID:25400598

  20. Embodiment of intersubjective time: relational dynamics as attractors in the temporal coordination of interpersonal behaviors and experiences

    PubMed Central

    Laroche, Julien; Berardi, Anna Maria; Brangier, Eric

    2014-01-01

    This paper addresses the issue of “being together,” and more specifically the issue of “being together in time.” We provide with an integrative framework that is inspired by phenomenology, the enactive approach and dynamical systems theories. To do so, we first define embodiment as a living and lived phenomenon that emerges from agent-world coupling. We then show that embodiment is essentially dynamical and therefore we describe experiential, behavioral and brain dynamics. Both lived temporality and the temporality of the living appear to be complex, multiscale phenomena. Next we discuss embodied dynamics in the context of interpersonal interactions, and briefly review the empirical literature on between-persons temporal coordination. Overall, we propose that being together in time emerges from the relational dynamics of embodied interactions and their flexible co-regulation. PMID:25400598

  1. Sequential and Coordinative Processing Dynamics in Figural Transformations across the Life Span.

    ERIC Educational Resources Information Center

    Mayr, Ulrich; And Others

    1996-01-01

    Investigated the proposition that two distinct factors involved in life span cognitive development are mental speed and coordination efficiency. Results show dissociable speed of processing and working memory functioning over the life span and age-related differential effects of coordinative demands. (ET)

  2. An Investigation of Embodied Language Comprehension from the Perspective of Coordination Dynamics

    ERIC Educational Resources Information Center

    Olmstead, Anne Jane

    2009-01-01

    In four experiments, participants performed sentence comprehension tasks simultaneously with bimanual coordination. Half of the sentences described events that could not be performed by a human (non-performable) and half described actions that could be performed by a human (performable). Effects of sentence type on coordination were indexed by…

  3. Coordinated measurements of low-energy electron precipitation and scintilations/TEC in the auroral oval

    SciTech Connect

    Basu, S.; Mackenzie, E.; Basu, S.

    1983-11-01

    A geostationary satellite transmitting at 244 MHz was employed in a coordinated observation study of low energy electron precipitation in the auroral oval from DMSP/F2 (a satellite in sun-synchronous circular orbit) and phase and amplitude scintillations from Goose Bay, Labrador. Total electron content and magnetometer measurements indicate that the precipitation event onset was 10 min prior to the DMSP pass. Within this time scale, the ionization generated in the F region could reach the topside, so that the thermal sensor on board the DMSP satellite could measure a factor of 2-3 density enhancement. The phase-to-amplitude ratio changed drastically by comparison to quiet magnetic times, implying that increased convection velocities during magnetic disturbances were partially responsible for the enhanced phase scintillation. 49 references.

  4. External and internal waves in stream-potential pressure-coordinate dynamics

    NASA Astrophysics Data System (ADS)

    Zirk, Marko; Rõõm, Rein

    2014-05-01

    In stream-potential dynamics pressure coordinate velocity -→v = {dx/dt,dy/dt,dp/dt} = {vx,vy,vp} = {u,v,ω } is presented in terms of 4D stream-potential {ψ0,ψx,ψy,ψp} -→v = downtriangleψ0 + downtriangle× -→ψ leftrightarrow vi = Giαδαψ0 + ɛαβγδβψγ, with diagonal metric tensor with main elements G11 = G22 = 1, G33 = p2/H2 (H = RT/g is the height scale). Vector potential -→ ψ is further expressed via horizontal curl and divergence of the stream function ω = δxψy - δyψx ≠¡ dp/dt, Ξ = δxψx + δyψy. The wave-vector components in linearized stream-potential dynamics are the scalar flow potential ψ0, surface pressure fluctuation p's, horizontal divergence Ξ and curl ω of the fluctuative part -→ψ' of complete vector potential -→ψ = -→ψ + -→ψ' . Equations for ψ0 and p's form the external wave subsystem δp' δ« ps dξ0 - -→- p2 δ2 -s+ downtriangle2 ψ0dp = 0, -+gH downtriangle2(p's/ps) = A0(ψ ,ω,Ξ), L0ψ0 = ξ0, L0 =-2 -2+downtriangle2, δt 0 dt H δp (1) while the equations for Ξ, ω and temperature fluctuation T' form the internal wave subsystem d-→ξ -→ -→- dT ' Tiω ( ) ( p2 δ2 ) p2 -dt = A (ψ,ω,Ξ), -dt = -p-+Q, L0Ξ = δp p2ξp/H2 , H2- δp2 + downtriangle2 ω = H2-(δyξx - δxξy) (2) with Ti = (R/cp)T - pδpT. In these equations 0 -→ α -→ -→ i iαβ ξ = downtriangle · v = δαv , ξ = downtriangle ×v leftrightarrow ξ = ɛ δαvβ are the 3D divergence and curl of velocity. In the presentation equation systems (1) and (2) are solved both analytically and numerically. Interaction of external waves with stationary internal orographic waves is investigated.

  5. Dynamic heart rate measurements from video sequences

    PubMed Central

    Yu, Yong-Poh; Raveendran, P.; Lim, Chern-Loon

    2015-01-01

    This paper shows how dynamic heart rate measurements that are typically obtained from sensors mounted near to the heart can also be obtained from video sequences. In this study, two experiments are carried out where a video camera captures the facial images of the seven subjects. The first experiment involves the measurement of subjects’ increasing heart rates (79 to 150 beats per minute (BPM)) while cycling whereas the second involves falling heart beats (153 to 88 BPM). In this study, independent component analysis (ICA) is combined with mutual information to ensure accuracy is not compromised in the use of short video duration. While both experiments are going on measures of heartbeat using the Polar heart rate monitor is also taken to compare with the findings of the proposed method. Overall experimental results show the proposed method can be used to measure dynamic heart rates where the root mean square error (RMSE) and the correlation coefficient are 1.88 BPM and 0.99 respectively. PMID:26203374

  6. Coordination properties of a metal chelator clioquinol to Zn(2+) studied by static DFT and ab initio molecular dynamics.

    PubMed

    Rodríguez-Santiago, Luis; Alí-Torres, Jorge; Vidossich, Pietro; Sodupe, Mariona

    2015-05-28

    Several lines of evidence supporting the role of metal ions in amyloid aggregation, one of the hallmarks of Alzheimer's disease (AD), have turned metal ion chelation into a promising therapeutic treatment. The design of efficient chelating ligands requires proper knowledge of the electronic and molecular structure of the complexes formed, including their hydration properties. Among various potential chelators, clioquinol (5-chloro-7-iodo-8-hydroxyquinoline, CQH) has been evaluated with relative success in in vitro experiments and even in phase 2 clinical trials. Clioquinol interacts with Zn(ii) to lead to a binary metal/ligand 1 : 2 stoichiometric complex in which the phenolic group of CQH is deprotonated, resulting in Zn(CQ)2 neutral complexes, to which additional water molecules may coordinate. In the present work, the coordinative properties of clioquinol in aqueous solution have been analyzed by means of static, minimal cluster based DFT calculations and explicit solvent ab initio molecular dynamics simulations. Results from static calculations accounting for solvent effects by means of polarized continuum models suggest that the preferred metal coordination environment is tetrahedral Zn(CQ)2, whereas ab initio molecular dynamics simulations point to quasi degenerate penta Zn(CQ)2(H2O) and hexa Zn(CQ)2(H2O)2 coordinated complexes. The possible reasons for these discrepant results are discussed. PMID:25939963

  7. Determination of dynamic corrections to point coordinates of photographs obtained by the Zond 6 and Zond 8 spacecraft. [image motion correction

    NASA Technical Reports Server (NTRS)

    Kiselev, V. V.; Rodionov, B. N.

    1974-01-01

    The linear and angular motions of the Zond 6 and Zond 8 spacecraft imaging camera during the exposure cause displacements of the optical image points. In the case of instantaneous exposure of each individual point and the nonsimultaneous exposure of the complete frame, this leads to finite geometric shifts of the points without causing blurring of the photographic image. Therefore, when measuring the resulting photographic pictures, the problem arises of reducing the picture point positions to a common instant of time. This reduction is performed by means of dynamic corrections to the measured picture point coordinates. These corrections are found by using formulas of dynamic photogrammetry. Their use with the Zond space probe photographs is described.

  8. Coordination and Hydrolysis of Plutonium Ions in Aqueous Solution using Car-Parrinello Molecular Dynamics Free Energy Simulations

    SciTech Connect

    Odoh, Samuel O.; Bylaska, Eric J.; De Jong, Wibe A.

    2013-11-27

    Car-Parrinello molecular dynamics (CPMD) simulations have been used to examine the hydration structures, coordination energetics and the first hydrolysis constants of Pu3+, Pu4+, PuO2+ and PuO22+ ions in aqueous solution at 300 K. The coordination numbers and structural properties of the first shell of these ions are in good agreement with available experimental estimates. The hexavalent PuO22+ species is coordinated to 5 aquo ligands while the pentavalent PuO2+ complex is coordinated to 4 aquo ligands. The Pu3+ and Pu4+ ions are both coordinated to 8 water molecules. The first hydrolysis constants obtained for Pu3+ and PuO22+ are 6.65 and 5.70 respectively, all within 0.3 pH units of the experimental values (6.90 and 5.50 respectively). The hydrolysis constant of Pu4+, 0.17, disagrees with the value of -0.60 in the most recent update of the Nuclear Energy Agency Thermochemical Database (NEA-TDB) but supports recent experimental findings. The hydrolysis constant of PuO2+, 9.51, supports the experimental results of Bennett et al. (Radiochim. Act. 1992, 56, 15). A correlation between the pKa of the first hydrolysis reaction and the effective charge of the plutonium center was found.

  9. Integrative data analysis through coordination of measurement and analysis protocol across independent longitudinal studies.

    PubMed

    Hofer, Scott M; Piccinin, Andrea M

    2009-06-01

    Replication of research findings across independent longitudinal studies is essential for a cumulative and innovative developmental science. Meta-analysis of longitudinal studies is often limited by the amount of published information on particular research questions, the complexity of longitudinal designs and the sophistication of analyses, and practical limits on full reporting of results. In many cases, cross-study differences in sample composition and measurements impede or lessen the utility of pooled data analysis. A collaborative, coordinated analysis approach can provide a broad foundation for cumulating scientific knowledge by facilitating efficient analysis of multiple studies in ways that maximize comparability of results and permit evaluation of study differences. The goal of such an approach is to maximize opportunities for replication and extension of findings across longitudinal studies through open access to analysis scripts and output for published results, permitting modification, evaluation, and extension of alternative statistical models and application to additional data sets. Drawing on the cognitive aging literature as an example, the authors articulate some of the challenges of meta-analytic and pooled-data approaches and introduce a coordinated analysis approach as an important avenue for maximizing the comparability, replication, and extension of results from longitudinal studies. PMID:19485626

  10. Integrative Data Analysis through Coordination of Measurement and Analysis Protocol across Independent Longitudinal Studies

    PubMed Central

    Hofer, Scott M.; Piccinin, Andrea M.

    2009-01-01

    Replication of research findings across independent longitudinal studies is essential for a cumulative and innovative developmental science. Meta-analysis of longitudinal studies is often limited by the amount of published information on particular research questions, the complexity of longitudinal designs and sophistication of analyses, and practical limits on full reporting of results. In many cases, cross-study differences in sample composition and measurements impede or lessen the utility of pooled data analysis. A collaborative, coordinated analysis approach can provide a broad foundation for cumulating scientific knowledge by facilitating efficient analysis of multiple studies in ways that maximize comparability of results and permit evaluation of study differences. The goal of such an approach is to maximize opportunities for replication and extension of findings across longitudinal studies through open access to analysis scripts and output for published results, permitting modification, evaluation, and extension of alternative statistical models, and application to additional data sets. Drawing on the cognitive aging literature as an example, we articulate some of the challenges of meta-analytic and pooled-data approaches and introduce a coordinated analysis approach as an important avenue for maximizing the comparability, replication, and extension of results from longitudinal studies. PMID:19485626

  11. Coordinated measurements made by the Sondrestrom radar and the Polar Bear ultraviolet imager

    SciTech Connect

    Robinson, R.; Vondrak, R. ); Dabbs, T.; Vickrey, J. ); Eastes, R.; Del Greco, F.; Huffman, R. ); Meng, C. ); Daniell, R.; Strickland, D.; Vondrak, R. )

    1992-03-01

    In 1986 and 1987 the Sondrestrom incoherent scatter radar in Greenland was operated routinely in coordination with selected overpasses of the Polar Bear satellite. For these experiments the auroral ionospheric remote sensor on Polar Bear obtained images of auroral emissions in two far ultraviolet wavelength bands centered at approximately 136 and 160 nm and one visible band centered at 391.4 nm. Measurements at these three wavelengths were extracted from the images for comparison with the coincident radar measurements. Model calculations have shown that for Maxwellian incident electron distributions the ratio between the 136-nm luminosity and 391.4-nm luminosity can be used to estimate the mean energy of precipitating electrons. Once the mean energy is known, then either of the two emissions can be used to determine the total energy flux. This procedure is used to determine the properties of the incident electron distribution during three midnight sector auroral events over Sondre Stromfjord. The incident electron flux is then used to calculate the expected height profile of electron density which is compared with the simultaneous and coincident radar measurements. The results show that the derived profiles agree well with the measured profiles both in the peak electron density and the altitude of the peak. The accuracy with which the peak of the profile is predicted by this technique is such that many important ionospheric parameters can be reliably inferred from remote measurements, including, for example, the height-integrated electrical conductivities.

  12. Application of a Force Sensor to Improve the Reliability of Measurement with Articulated Arm Coordinate Measuring Machines

    PubMed Central

    González-Madruga, Daniel; Eduardo Cuesta, González; Joaquín Barreiro, García; Fernandez-Abia, Ana Isabel

    2013-01-01

    A study of the operator contact force influence on the performance of Articulated Arm Coordinate Measuring Machines (AACMMs) is presented in this paper. After developing a sensor capable of measuring the contact force applied by an operator, a ring gauge has been used to analyse the relationship between the contact force and diameter and form errors measured with the AACMM. As a result, contact force has been proved as one of the main factors influencing the AACMM performance. A probe deflection model based on the Finite Element Method (FEM) has been also proposed in order to obtain the AACMM probe deflection caused by contact force. This allows measurement correction by comparing them with reference values, specifically, a ring gauge. Experimental test results show a significant measurement improvement that minimizes diameter error. Finally, an uncertainty evaluation for the contact force sensor and AACMM measurements with and without probe deflection model has been carried out in order to validate the ability of the sensor and the methodology followed. PMID:23945737

  13. Application of a force sensor to improve the reliability of measurement with Articulated Arm Coordinate Measuring Machines.

    PubMed

    González-Madruga, Daniel; Cuesta González, Eduardo; Barreiro García, Joaquín; Fernandez-Abia, Ana Isabel

    2013-01-01

    A study of the operator contact force influence on the performance of Articulated Arm Coordinate Measuring Machines (AACMMs) is presented in this paper. After developing a sensor capable of measuring the contact force applied by an operator, a ring gauge has been used to analyse the relationship between the contact force and diameter and form errors measured with the AACMM. As a result, contact force has been proved as one of the main factors influencing the AACMM performance. A probe deflection model based on the Finite Element Method (FEM) has been also proposed in order to obtain the AACMM probe deflection caused by contact force. This allows measurement correction by comparing them with reference values, specifically, a ring gauge. Experimental test results show a significant measurement improvement that minimizes diameter error. Finally, an uncertainty evaluation for the contact force sensor and AACMM measurements with and without probe deflection model has been carried out in order to validate the ability of the sensor and the methodology followed. PMID:23945737

  14. Hawking Radiation and Entropy of a Dynamic Dilaton-Maxwell Black Hole with a New Tortoise Coordinate Transformation

    NASA Astrophysics Data System (ADS)

    Lan, Xiao-Gang

    2013-05-01

    By introducing a new tortoise coordinate transformation, we apply Damour-Ruffini-Sannan method to study the Hawking radiation of massive scalar particles in a dynamic Dilaton-Maxwell black hole. We find that Hawking radiation spectrum shows still the blackbody one, while the Hawking temperature is significantly changed. Additionally, by adopting the thin film method, we calculate the entropy of a dynamic Dilaton-Maxwell black hole. The result indicates that the entropy for such a black hole is still in proportional to the area of its event horizon.

  15. Measurement of Gear Tooth Dynamic Friction

    NASA Technical Reports Server (NTRS)

    Rebbechi, Brian; Oswald, Fred B.; Townsend, Dennis P.

    1996-01-01

    Measurements of dynamic friction forces at the gear tooth contact were undertaken using strain gages at the root fillets of two successive teeth. Results are presented from two gear sets over a range of speeds and loads. The results demonstrate that the friction coefficient does not appear to be significantly influenced by the sliding reversal at the pitch point, and that the friction coefficient values found are in accord with those in general use. The friction coefficient was found to increase at low sliding speeds. This agrees with the results of disc machine testing.

  16. A dynamic care pathway to coordinate the use of advanced therapy in diabetic foot ulceration.

    PubMed

    Chadwick, P; Haycocks, S; Bielby, A; Milne, J

    2009-10-01

    The non-coordinated use of advanced therapies is not clinically or cost effective. A care pathway for the sequential use of these interventions on complex wounds provides a more restructured approach, and helped improve patient outcomes. PMID:19816383

  17. Non-coincident Inter-instrument Comparisons of Ozone Measurements Using Quasi-conservative Coordinates

    NASA Technical Reports Server (NTRS)

    Lait, L. R.; Newman, P. A.; Schoeberl, M. R.; McGee, T.; Twigg, T.; Browell, E.; Bevilacqua, R.; Andersen, S. B.; DeBacker, H.; Benesova, A.

    2004-01-01

    Ozone measurements from ozonesondes, AROTAL, DIAL, and POAM III instruments during the SOLVE-2/VINTERSOL period are composited in a time-varying, flow-following quasi-conservative (PV-6) coordinate space; the resulting composites from each instrument are mapped onto the other instruments locations and times. The mapped data are then used to intercompare data from the different instruments. Overall, the four data sets are found to be in good agreement. AROTAL shows somewhat lower values below 16 km, and DIAL has a positive bias at the upper limits of its altitude range. These intercomparisons are consistent with those obtained from more conventional near-coincident profiles, where available. Although the PV-theta mapping technique entails larger uncertainties of individual profile differences compared to direct near-coincident comparisons, the ability to include much larger numbers of comparisons can make this technique advantageous.

  18. Atomic Quadrupole Moment Measurement Using Dynamic Decoupling.

    PubMed

    Shaniv, R; Akerman, N; Ozeri, R

    2016-04-01

    We present a method that uses dynamic decoupling of a multilevel quantum probe to distinguish small frequency shifts that depend on m_{j}^{2}, where m_{j}^{2} is the angular momentum of level |j⟩ along the quantization axis, from large noisy shifts that are linear in m_{j}, such as those due to magnetic field noise. Using this method we measured the electric-quadrupole moment of the 4D_{5/2} level in ^{88}Sr^{+} to be 2.973_{-0.033}^{+0.026}ea_{0}^{2}. Our measurement improves the uncertainty of this value by an order of magnitude and thus helps mitigate an important systematic uncertainty in ^{88}Sr^{+} based optical atomic clocks and verifies complicated many-body quantum calculations. PMID:27104691

  19. Atomic Quadrupole Moment Measurement Using Dynamic Decoupling

    NASA Astrophysics Data System (ADS)

    Shaniv, R.; Akerman, N.; Ozeri, R.

    2016-04-01

    We present a method that uses dynamic decoupling of a multilevel quantum probe to distinguish small frequency shifts that depend on mj2, where mj2 is the angular momentum of level |j ⟩ along the quantization axis, from large noisy shifts that are linear in mj, such as those due to magnetic field noise. Using this method we measured the electric-quadrupole moment of the 4 D5 /2 level in 88Sr+ to be 2.97 3-0.033+0.026e a02 . Our measurement improves the uncertainty of this value by an order of magnitude and thus helps mitigate an important systematic uncertainty in 88Sr+ based optical atomic clocks and verifies complicated many-body quantum calculations.

  20. Asymmetric coordination chemistry by chiral-auxiliary-mediated dynamic resolution under thermodynamic control.

    PubMed

    Lin, Zhijie; Gong, Lei; Celik, Mehmet Ali; Harms, Klaus; Frenking, Gernot; Meggers, Eric

    2011-02-01

    A method is presented for the asymmetric synthesis of chiral ruthenium polypyridyl complexes that starts from racemic cis-[Ru(pp)(2)Cl(2)] (pp=2,2'-bipyridine or 1,10-phenanthroline ligands). The chiral bidentate ligands (R)-2-(isopropylsulfinyl)phenol, (R)-SO, and preferably the more electron-rich derivative (R)-2-(isopropylsulfinyl)-4-methoxyphenol, (R)-SO', serve as convenient chiral auxiliaries for the conversion of racemic starting complexes (1a: pp=2,2'-bipyridine; 1b: pp=5,5'-dimethyl-2,2'-bipyridine; c: pp=1,10-phenanthroline) into single diastereomers Λ-[Ru(pp)(2){(R)-SO}]PF(6) (Λ-(S)-2a-c) or Λ-[Ru(pp)(2){(R)-SO'}]PF(6) (Λ-(S)-2a') under a thermodynamically controlled dynamic transformation. The complexes Λ-(S)-2a-c and Λ-(S)-2a' themselves are direct precursors for the generation of optically active ruthenium-polypyridyl complexes by trifluoroacetic-acid-induced replacement of the sulfinylphenolate auxiliaries with bidentate pp ligands under retention of configuration, thereby affording Λ-[Ru(pp)(3)](PF(6))(2) (3a-c) complexes with high enantiomeric ratios of ≥98:2. In particular, by employing the methoxy-modified chiral auxiliary (R)-SO', enantiomeric ratios of >99:1 were reached. In the strategy introduced here, the high steric crowding of an octahedral coordination sphere was exploited by placing a sulfur-based stereocenter in direct proximity to the ruthenium stereocenter, thereby leading to a large difference in the stabilities of the intermediate Λ-S and Δ-S diastereomers and thus providing the opportunity to find suitable reaction conditions for conversion of the destabilized diastereomer into the thermodynamically more-stable one. This method should be of high practical value for the asymmetric synthesis of ruthenium-polypyridyl complexes because it allows one to use readily available racemic ruthenium complexes as starting materials. PMID:21254425

  1. The dynamics of information-driven coordination phenomena: A transfer entropy analysis

    PubMed Central

    Borge-Holthoefer, Javier; Perra, Nicola; Gonçalves, Bruno; González-Bailón, Sandra; Arenas, Alex; Moreno, Yamir; Vespignani, Alessandro

    2016-01-01

    Data from social media provide unprecedented opportunities to investigate the processes that govern the dynamics of collective social phenomena. We consider an information theoretical approach to define and measure the temporal and structural signatures typical of collective social events as they arise and gain prominence. We use the symbolic transfer entropy analysis of microblogging time series to extract directed networks of influence among geolocalized subunits in social systems. This methodology captures the emergence of system-level dynamics close to the onset of socially relevant collective phenomena. The framework is validated against a detailed empirical analysis of five case studies. In particular, we identify a change in the characteristic time scale of the information transfer that flags the onset of information-driven collective phenomena. Furthermore, our approach identifies an order-disorder transition in the directed network of influence between social subunits. In the absence of clear exogenous driving, social collective phenomena can be represented as endogenously driven structural transitions of the information transfer network. This study provides results that can help define models and predictive algorithms for the analysis of societal events based on open source data. PMID:27051875

  2. The dynamics of information-driven coordination phenomena: A transfer entropy analysis.

    PubMed

    Borge-Holthoefer, Javier; Perra, Nicola; Gonçalves, Bruno; González-Bailón, Sandra; Arenas, Alex; Moreno, Yamir; Vespignani, Alessandro

    2016-04-01

    Data from social media provide unprecedented opportunities to investigate the processes that govern the dynamics of collective social phenomena. We consider an information theoretical approach to define and measure the temporal and structural signatures typical of collective social events as they arise and gain prominence. We use the symbolic transfer entropy analysis of microblogging time series to extract directed networks of influence among geolocalized subunits in social systems. This methodology captures the emergence of system-level dynamics close to the onset of socially relevant collective phenomena. The framework is validated against a detailed empirical analysis of five case studies. In particular, we identify a change in the characteristic time scale of the information transfer that flags the onset of information-driven collective phenomena. Furthermore, our approach identifies an order-disorder transition in the directed network of influence between social subunits. In the absence of clear exogenous driving, social collective phenomena can be represented as endogenously driven structural transitions of the information transfer network. This study provides results that can help define models and predictive algorithms for the analysis of societal events based on open source data. PMID:27051875

  3. A PLM-based automated inspection planning system for coordinate measuring machine

    NASA Astrophysics Data System (ADS)

    Zhao, Haibin; Wang, Junying; Wang, Boxiong; Wang, Jianmei; Chen, Huacheng

    2006-11-01

    With rapid progress of Product Lifecycle Management (PLM) in manufacturing industry, automatic generation of inspection planning of product and the integration with other activities in product lifecycle play important roles in quality control. But the techniques for these purposes are laggard comparing with techniques of CAD/CAM. Therefore, an automatic inspection planning system for Coordinate Measuring Machine (CMM) was developed to improve the automatization of measuring based on the integration of inspection system in PLM. Feature information representation is achieved based on a PLM canter database; measuring strategy is optimized through the integration of multi-sensors; reasonable number and distribution of inspection points are calculated and designed with the guidance of statistic theory and a synthesis distribution algorithm; a collision avoidance method is proposed to generate non-collision inspection path with high efficiency. Information mapping is performed between Neutral Interchange Files (NIFs), such as STEP, DML, DMIS, XML, etc., to realize information integration with other activities in the product lifecycle like design, manufacturing and inspection execution, etc. Simulation was carried out to demonstrate the feasibility of the proposed system. As a result, the inspection process is becoming simpler and good result can be got based on the integration in PLM.

  4. Spin-labelled cyclometallated palladium complexes. EPR study of dynamic processes in coordination sphere

    NASA Astrophysics Data System (ADS)

    Kozhanov, K. A.; Bubnov, M. P.; Abakumov, G. A.; Cherkasov, V. K.

    2012-12-01

    New four-, five- and six-coordinated cyclometallated o-semiquinonato palladium complexes were obtained and characterized in solution by EPR. Interaction of square-planar azaphenyl palladium semiquinonate with mono and bidentate phosphane donors leads to formation of five- and six-coordinated adducts. Typical values of HFC constants on apical and basal phosphorouses are observed for such compounds. In one case the reversible addition of tri-phenyl-phosphane was observed. The coordination mode of pincer ligand (bi- or tridentate) in o-semiquinonato pincer complexes depends on the nature of linker between coordinating group and pincer aryl ring. In the case of sbnd CH2sbnd linker five coordinated complexes are formed. The "swing" and "fan" oscillations are observed for these compounds. Complexes with sbnd Osbnd linker are the first examples of compounds with bidentate bonded phosphorous-based pincer ligand. Most of complexes are unstable and decompose during some hours. Only the application of o-semiquinones as spin labels and using the EPR technique made possible to observe and interpret their structure.

  5. Subcellular and Dynamic Coordination between Src Activity and Cell Protrusion in Microenvironment

    PubMed Central

    Zhuo, Yue; Qian, Tongcheng; Wu, Yiqian; Seong, Jihye; Gong, Ya; Ma, Hongwei; Wang, Yingxiao; Lu, Shaoying

    2015-01-01

    Migration of endothelial cells is essential for wound healing and angiogenesis. Src kinase activity plays important roles at the protrusions of migrating endothelial cells. However, the spatiotemporal coordination between Src kinase activity and the protrusion of cell edge remains unclear. Therefore, we investigate these coordinated molecular events at the initiation of cell migration, by integrating microfabrication, fluorescence resonance energy transfer (FRET)-based biosensors, and automated computational image analysis. We demonstrate that the physical release of restrictive micropattern triggered a significant decrease of Src activity at the protrusive edge of endothelial cells. Computational cross-correlation analysis reveals that the decrease of Src activity occurred earlier in time, and was well-coordinated with the protrusion of cell edge in polarized cells, but not in non-polarized cells. These results suggest that the spatiotemporal control of Src kinase activity is well-coordinated with cell polarization and protrusion in endothelial cells upon the release of physical constraint, as that experienced by endothelial cells sprouting from stiff tumor micro-environment during angiogenesis. Therefore, our integrative approach enabled the discovery of a new model where Src is de-activated in coordination with membrane protrusion, providing important insights into the regulation of endothelial migration and angiogenesis. PMID:26261043

  6. Subcellular and Dynamic Coordination between Src Activity and Cell Protrusion in Microenvironment

    NASA Astrophysics Data System (ADS)

    Zhuo, Yue; Qian, Tongcheng; Wu, Yiqian; Seong, Jihye; Gong, Ya; Ma, Hongwei; Wang, Yingxiao; Lu, Shaoying

    2015-08-01

    Migration of endothelial cells is essential for wound healing and angiogenesis. Src kinase activity plays important roles at the protrusions of migrating endothelial cells. However, the spatiotemporal coordination between Src kinase activity and the protrusion of cell edge remains unclear. Therefore, we investigate these coordinated molecular events at the initiation of cell migration, by integrating microfabrication, fluorescence resonance energy transfer (FRET)-based biosensors, and automated computational image analysis. We demonstrate that the physical release of restrictive micropattern triggered a significant decrease of Src activity at the protrusive edge of endothelial cells. Computational cross-correlation analysis reveals that the decrease of Src activity occurred earlier in time, and was well-coordinated with the protrusion of cell edge in polarized cells, but not in non-polarized cells. These results suggest that the spatiotemporal control of Src kinase activity is well-coordinated with cell polarization and protrusion in endothelial cells upon the release of physical constraint, as that experienced by endothelial cells sprouting from stiff tumor micro-environment during angiogenesis. Therefore, our integrative approach enabled the discovery of a new model where Src is de-activated in coordination with membrane protrusion, providing important insights into the regulation of endothelial migration and angiogenesis.

  7. Subcellular and Dynamic Coordination between Src Activity and Cell Protrusion in Microenvironment.

    PubMed

    Zhuo, Yue; Qian, Tongcheng; Wu, Yiqian; Seong, Jihye; Gong, Ya; Ma, Hongwei; Wang, Yingxiao; Lu, Shaoying

    2015-01-01

    Migration of endothelial cells is essential for wound healing and angiogenesis. Src kinase activity plays important roles at the protrusions of migrating endothelial cells. However, the spatiotemporal coordination between Src kinase activity and the protrusion of cell edge remains unclear. Therefore, we investigate these coordinated molecular events at the initiation of cell migration, by integrating microfabrication, fluorescence resonance energy transfer (FRET)-based biosensors, and automated computational image analysis. We demonstrate that the physical release of restrictive micropattern triggered a significant decrease of Src activity at the protrusive edge of endothelial cells. Computational cross-correlation analysis reveals that the decrease of Src activity occurred earlier in time, and was well-coordinated with the protrusion of cell edge in polarized cells, but not in non-polarized cells. These results suggest that the spatiotemporal control of Src kinase activity is well-coordinated with cell polarization and protrusion in endothelial cells upon the release of physical constraint, as that experienced by endothelial cells sprouting from stiff tumor micro-environment during angiogenesis. Therefore, our integrative approach enabled the discovery of a new model where Src is de-activated in coordination with membrane protrusion, providing important insights into the regulation of endothelial migration and angiogenesis. PMID:26261043

  8. Dynamic neurotransmitter interactions measured with PET

    SciTech Connect

    Schiffer, W.K.; Dewey, S.L.

    2001-04-02

    Positron emission tomography (PET) has become a valuable interdisciplinary tool for understanding physiological, biochemical and pharmacological functions at a molecular level in living humans, whether in a healthy or diseased state. The utility of tracing chemical activity through the body transcends the fields of cardiology, oncology, neurology and psychiatry. In this, PET techniques span radiochemistry and radiopharmaceutical development to instrumentation, image analysis, anatomy and modeling. PET has made substantial contributions in each of these fields by providing a,venue for mapping dynamic functions of healthy and unhealthy human anatomy. As diverse as the disciplines it bridges, PET has provided insight into an equally significant variety of psychiatric disorders. Using the unique quantitative ability of PET, researchers are now better able to non-invasively characterize normally occurring neurotransmitter interactions in the brain. With the knowledge that these interactions provide the fundamental basis for brain response, many investigators have recently focused their efforts on an examination of the communication between these chemicals in both healthy volunteers and individuals suffering from diseases classically defined as neurotransmitter specific in nature. In addition, PET can measure the biochemical dynamics of acute and sustained drug abuse. Thus, PET studies of neurotransmitter interactions enable investigators to describe a multitude of specific functional interactions in the human brain. This information can then be applied to understanding side effects that occur in response to acute and chronic drug therapy, and to designing new drugs that target multiple systems as opposed to single receptor types. Knowledge derived from PET studies can be applied to drug discovery, research and development (for review, see (Fowler et al., 1999) and (Burns et al., 1999)). Here, we will cover the most substantial contributions of PET to understanding

  9. Aging induced loss of complexity and dedifferentiation: consequences for coordination dynamics within and between brain, muscular and behavioral levels

    PubMed Central

    Sleimen-Malkoun, Rita; Temprado, Jean-Jacques; Hong, S. Lee

    2014-01-01

    Growing evidence demonstrates that aging not only leads to structural and functional alterations of individual components of the neuro-musculo-skeletal system (NMSS) but also results in a systemic re-organization of interactions within and between the different levels and functional domains. Understanding the principles that drive the dynamics of these re-organizations is an important challenge for aging research. The present Hypothesis and Theory paper is a contribution in this direction. We propose that age-related declines in brain and behavior that have been characterized in the literature as dedifferentiation and the loss of complexity (LOC) are: (i) synonymous; and (ii) integrated. We argue that a causal link between the aforementioned phenomena exists, evident in the dynamic changes occurring in the aging NMSS. Through models and methods provided by a dynamical systems approach to coordination processes in complex living systems, we: (i) formalize operational hypotheses about the general principles of changes in cross-level and cross-domain interactions during aging; and (ii) develop a theory of the aging NMSS based on the combination of the frameworks of coordination dynamics (CD), dedifferentiation, and LOC. Finally, we provide operational predictions in the study of aging at neural, muscular, and behavioral levels, which lead to testable hypotheses and an experimental agenda to explore the link between CD, LOC and dedifferentiation within and between these different levels. PMID:25018731

  10. Conditions for order and chaos in the dynamics of a trapped Bose-Einstein condensate in coordinate and energy space

    NASA Astrophysics Data System (ADS)

    Sakhel, Roger R.; Sakhel, Asaad R.; Ghassib, Humam B.; Balaz, Antun

    2016-03-01

    We investigate numerically conditions for order and chaos in the dynamics of an interacting Bose-Einstein condensate (BEC) confined by an external trap cut off by a hard-wall box potential. The BEC is stirred by a laser to induce excitations manifesting as irregular spatial and energy oscillations of the trapped cloud. Adding laser stirring to the external trap results in an effective time-varying trapping frequency in connection with the dynamically changing combined external+laser potential trap. The resulting dynamics are analyzed by plotting their trajectories in coordinate phase space and in energy space. The Lyapunov exponents are computed to confirm the existence of chaos in the latter space. Quantum effects and trap anharmonicity are demonstrated to generate chaos in energy space, thus confirming its presence and implicating either quantum effects or trap anharmonicity as its generator. The presence of chaos in energy space does not necessarily translate into chaos in coordinate space. In general, a dynamic trapping frequency is found to promote chaos in a trapped BEC. An apparent means to suppress chaos in a trapped BEC is achieved by increasing the characteristic scale of the external trap with respect to the condensate size.

  11. Crystalline coordination framework endowed with dynamic gate-opening behaviour by being downsized to a thin film

    NASA Astrophysics Data System (ADS)

    Sakaida, Shun; Otsubo, Kazuya; Sakata, Osami; Song, Chulho; Fujiwara, Akihiko; Takata, Masaki; Kitagawa, Hiroshi

    2016-04-01

    The fabrication of porous coordination frameworks in thin-film forms has been investigated intensively with a view to using their structural response to external stimuli and guests for potential nanotechnological applications, for example as membranes for gas separation. Here we report a coordination framework that exhibits a dynamic guest-sorption behaviour in a nanometre-sized thin-film form (16 nm thick), yet shows no guest uptake in the bulk. Highly oriented crystalline thin films of this coordination framework—which consists of interdigitated two-dimensional layers of {Fe(py)2[Pt(CN)4]} (py, pyridine)—were fabricated through liquid-phase layer-by-layer synthesis. The resulting thin film exhibited a clear guest uptake with a structural transformation of the gate-opening type as characterized by in situ X-ray diffraction. Increasing the film's thickness markedly suppressed this behaviour. We envisage that such a crystal-downsizing effect may be observed with other coordination frameworks, and may be of use to develop functional materials, for example, for switching or sensing devices.

  12. Crystalline coordination framework endowed with dynamic gate-opening behaviour by being downsized to a thin film.

    PubMed

    Sakaida, Shun; Otsubo, Kazuya; Sakata, Osami; Song, Chulho; Fujiwara, Akihiko; Takata, Masaki; Kitagawa, Hiroshi

    2016-04-01

    The fabrication of porous coordination frameworks in thin-film forms has been investigated intensively with a view to using their structural response to external stimuli and guests for potential nanotechnological applications, for example as membranes for gas separation. Here we report a coordination framework that exhibits a dynamic guest-sorption behaviour in a nanometre-sized thin-film form (16 nm thick), yet shows no guest uptake in the bulk. Highly oriented crystalline thin films of this coordination framework-which consists of interdigitated two-dimensional layers of {Fe(py)2[Pt(CN)4]} (py, pyridine)-were fabricated through liquid-phase layer-by-layer synthesis. The resulting thin film exhibited a clear guest uptake with a structural transformation of the gate-opening type as characterized by in situ X-ray diffraction. Increasing the film's thickness markedly suppressed this behaviour. We envisage that such a crystal-downsizing effect may be observed with other coordination frameworks, and may be of use to develop functional materials, for example, for switching or sensing devices. PMID:27001734

  13. Measurements and analysis of end-to-end Internet dynamics

    SciTech Connect

    Paxson, V

    1997-04-01

    Accurately characterizing end-to-end Internet dynamics - the performance that a user actually obtains from the lengthy series of network links that comprise a path through the Internet - is exceptionally difficult, due to the network`s immense heterogeneity. At the heart of this work is a `measurement framework` in which a number of sites around the Internet host a specialized measurement service. By coordinating `probes` between pairs of these sites one can measure end-to-end behavior along O(N{sup 2}) paths for a framework consisting of N sites. Consequently, one obtains a superlinear scaling that allows measuring a rich cross-section of Internet behavior without requiring huge numbers of observation points. 37 sites participated in this study, allowing the author to measure more than 1,000 distinct Internet paths. The first part of this work looks at the behavior of end-to-end routing: the series of routers over which a connection`s packets travel. Based on 40,000 measurements made using this framework, the author analyzes: routing `pathologies` such as loops, outages, and flutter; the stability of routes over time; and the symmetry of routing along the two directions of an end-to-end path. The author finds that pathologies increased significantly over the course of 1995 and that Internet paths are heavily dominated by a single route. The second part of this work studies end-to-end Internet packet dynamics. The author analyzes 20,000 TCP transfers of 100 Kbyte each to investigate the performance of both the TCP endpoints and the Internet paths. The measurements used for this part of the study are much richer than those for the first part, but require a great degree of attention to issues of calibration, which are addressed by applying self-consistency checks to the measurements whenever possible. The author finds that packet filters are capable of a wide range of measurement errors, some of which, if undetected, can significantly taint subsequent analysis.

  14. Combining radial basis function surrogates and dynamic coordinate search in high-dimensional expensive black-box optimization

    NASA Astrophysics Data System (ADS)

    Regis, Rommel G.; Shoemaker, Christine A.

    2013-05-01

    This article presents the DYCORS (DYnamic COordinate search using Response Surface models) framework for surrogate-based optimization of HEB (High-dimensional, Expensive, and Black-box) functions that incorporates an idea from the DDS (Dynamically Dimensioned Search) algorithm. The iterate is selected from random trial solutions obtained by perturbing only a subset of the coordinates of the current best solution. Moreover, the probability of perturbing a coordinate decreases as the algorithm reaches the computational budget. Two DYCORS algorithms that use RBF (Radial Basis Function) surrogates are developed: DYCORS-LMSRBF is a modification of the LMSRBF algorithm while DYCORS-DDSRBF is an RBF-assisted DDS. Numerical results on a 14-D watershed calibration problem and on eleven 30-D and 200-D test problems show that DYCORS algorithms are generally better than EGO, DDS, LMSRBF, MADS with kriging, SQP, an RBF-assisted evolution strategy, and a genetic algorithm. Hence, DYCORS is a promising approach for watershed calibration and for HEB optimization.

  15. Geometrically motivated coordinate system for exploring spacetime dynamics in numerical-relativity simulations using a quasi-Kinnersley tetrad

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Brink, Jeandrew; Szilágyi, Béla; Lovelace, Geoffrey

    2012-10-01

    We investigate the suitability and properties of a quasi-Kinnersley tetrad and a geometrically motivated coordinate system as tools for quantifying both strong-field and wave-zone effects in numerical relativity (NR) simulations. We fix two of the coordinate degrees of freedom of the metric, namely, the radial and latitudinal coordinates, using the Coulomb potential associated with the quasi-Kinnersley transverse frame. These coordinates are invariants of the spacetime and can be used to unambiguously fix the outstanding spin-boost freedom associated with the quasi-Kinnersley frame (and thus can be used to choose a preferred quasi-Kinnersley tetrad). In the limit of small perturbations about a Kerr spacetime, these geometrically motivated coordinates and quasi-Kinnersley tetrad reduce to Boyer-Lindquist coordinates and the Kinnersley tetrad, irrespective of the simulation gauge choice. We explore the properties of this construction both analytically and numerically, and we gain insights regarding the propagation of radiation described by a super-Poynting vector, further motivating the use of this construction in NR simulations. We also quantify in detail the peeling properties of the chosen tetrad and gauge. We argue that these choices are particularly well-suited for a rapidly converging wave-extraction algorithm as the extraction location approaches infinity, and we explore numerically the extent to which this property remains applicable on the interior of a computational domain. Using a number of additional tests, we verify numerically that the prescription behaves as required in the appropriate limits regardless of simulation gauge; these tests could also serve to benchmark other wave extraction methods. We explore the behavior of the geometrically motivated coordinate system in dynamical binary-black-hole NR mergers; while we obtain no unexpected results, we do find that these coordinates turn out to be useful for visualizing NR simulations (for example, for

  16. Measuring Visual Expertise in Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Hertzberg, Jean; Curran, Tim; Goodman, Katherine

    2014-11-01

    What role does visual expertise play in the learning of abstract physics? In surveys for the Flow Visualization course at the University of Colorado, Boulder, students often commented positively about a new awareness of fluid dynamics in everyday life. Could this new awareness, termed visual expertise, be measured in some way? Working with research psychologists at CU Boulder, who had already been working in this area on projects such as face recognition, a study was developed. This study had subjects with no prior fluid dynamics expertise classify flow images as either turbulent or laminar. The first group was given error-driven learning; that is, they had to guess the correct category for each image, were given feedback as to whether they had guessed correctly, and after a period of training, were tested on both the training images and a set of similar but new images. A second group was given simple instruction for the training images; that is, they were shown the image along with the name of the correct category, before being tested on both training images and new images. Preliminary results of the pilot study are presented, along with next steps. This work is supported by NSF Grant Number 1240294.

  17. Dynamic plasmapause model based on THEMIS measurements

    NASA Astrophysics Data System (ADS)

    Liu, X.; Liu, W.; Cao, J. B.; Fu, H. S.; Yu, J.; Li, X.

    2015-12-01

    This paper presents a dynamic plasmapause location model established based on 5 years of Time History of Events and Macroscale Interactions during Substorms (THEMIS) measurements from 2009 to 2013. In total, 5878 plasmapause crossing events are identified, sufficiently covering all 24 magnetic local time (MLT) sectors. Based on this plasmapause crossing database, we investigate the correlations between plasmapause locations with solar wind parameters and geomagnetic indices. Input parameters for the best fits are obtained for different MLT sectors, and finally, we choose five input parameters to build a plasmapause location model, including 5 min-averaged SYM-H, AL, and AU indices as well as hourly-averaged AE and Kp indices. two out-of-sample comparisons on the evolution of the plasmapause is shown during two magnetic storms, demonstrating good agreement between model results and observations. Two major advantages are achieved by this model. First, this model provides plasmapause locations at 24 MLT sectors, still providing good consistency with observations. Second, this model is able to reproduce dynamic variations of the plasmapause on timescales as short as 5 min.

  18. SPC techniques for the M-48 Coordinate Measurement Machine applied to uncertainty analysis and monitoring

    SciTech Connect

    Escher, R.N. Jr.

    1998-04-14

    The Moore M-48 Coordinate Measuring Machine (CMM) is used to calibrate step gages, ball bars and hole plates. The expanded uncertainty (2 sigma) of the M-48 CMM was determined to be {+-}0.3 + 0.4 L microns (L is length in meters), using the decomposition method. The problem statement becomes, how does one monitor and control the calibration process to ensure that one maintains this level of reliability? Traditional methods of statistical process control, such as X-bar and R charts assume large lot production and are designed to detect changes in the process being monitored. Since calibrations are performed one at a time, with sometimes years between calibrations, standard control charting methodology falls a bit short of what is needed to maintain process capability. Upon examination of the process uncertainty for the M-48 CMM the author finds the following parameters play an important roll in process capability. Since the M-48 uses laser scales, the Edlen equation is used to convert pressure, temperature and humidity to wavelength correction. The largest source of uncertainty comes from temperature effects based on gradients, accuracy of the thermistors and the actual coefficient of thermal expansion of the artifact. The probe calibration, which is performed for each calibration, is another important variable. Since the M-48 CMM`s movement is very slow, drift is also an important parameter to monitor. The paper describes the selection of check standards and measurement protocol made.

  19. Measuring multipartite entanglement through dynamic susceptibilities

    NASA Astrophysics Data System (ADS)

    Hauke, Philipp; Heyl, Markus; Tagliacozzo, Luca; Zoller, Peter

    2016-08-01

    Entanglement is considered an essential resource in quantum technologies, and central to the understanding of quantum many-body physics. Developing protocols to detect and quantify the entanglement of many-particle quantum states is thus a key challenge for present experiments. Here, we show that the quantum Fisher information, a witness for genuinely multipartite entanglement, becomes measurable for thermal ensembles by means of the dynamic susceptibility--that is, with resources readily available in present cold atomic-gas and condensed-matter experiments. This establishes a connection between multipartite entanglement and many-body correlations contained in response functions, with immediate implications close to quantum phase transitions, where the quantum Fisher information becomes universal, allowing us to identify strongly entangled phase transitions with a divergent multipartite entanglement. We illustrate our framework using paradigmatic quantum Ising models, and point out potential signatures in optical-lattice experiments and strongly correlated materials.

  20. Measuring Atmospheric Dynamics on Titan with AO

    NASA Astrophysics Data System (ADS)

    Adamkovics, Mate; de Pater, I.; Hartung, M.

    2009-05-01

    The cycling of fluid methane between Titan's atmosphere and surface, via seemingly familiar meteorological phenomena, is often compared to Earth's hydrology. Near-IR observations with AO resolve the moon's 1" disk, measure spatial variation in both the surface reflectivity and scattering in the atmosphere, and constrain the methane cycle. Forward models of the atmosphere are compared to observations and used to identify and quantify sources and altitudes of atmospheric opacity; including aerosols, clouds, and precipitation. The ubiquitous submicron aerosol hazes are tracers of global stratospheric dynamics over yearly timescales. Cloud properties may constrain the tropospheric circulation and are observed to change on hourly, daily, and seasonal timescales. Here we present observations of the daily life-cycle of a cloud system, a signature of tropospheric precipitation, seasonal changes in aerosol, and discuss the models that are used to quantify the observed meteorology.

  1. A Multi-layer Dynamic Model for Coordination Based Group Decision Making in Water Resource Allocation and Scheduling

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Zhang, Xingnan; Li, Chenming; Wang, Jianying

    Management of group decision-making is an important issue in water source management development. In order to overcome the defects in lacking of effective communication and cooperation in the existing decision-making models, this paper proposes a multi-layer dynamic model for coordination in water resource allocation and scheduling based group decision making. By introducing the scheme-recognized cooperative satisfaction index and scheme-adjusted rationality index, the proposed model can solve the problem of poor convergence of multi-round decision-making process in water resource allocation and scheduling. Furthermore, the problem about coordination of limited resources-based group decision-making process can be solved based on the effectiveness of distance-based group of conflict resolution. The simulation results show that the proposed model has better convergence than the existing models.

  2. Analyzing Group Coordination when Solving Geometry Problems with Dynamic Geometry Software

    ERIC Educational Resources Information Center

    Oner, Diler

    2013-01-01

    In CSCL research, collaborative activity is conceptualized along various yet intertwined dimensions. When functioning within these multiple dimensions, participants make use of several resources, which can be social or content-related (and sometimes temporal) in nature. It is the effective coordination of these resources that appears to…

  3. Review and Evaluation of Hand-Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces.

    PubMed

    Dong, Ren G; Sinsel, Erik W; Welcome, Daniel E; Warren, Christopher; Xu, Xueyan S; McDowell, Thomas W; Wu, John Z

    2015-09-01

    The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study. PMID:26929824

  4. Review and Evaluation of Hand–Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces

    PubMed Central

    Dong, Ren G.; Sinsel, Erik W.; Welcome, Daniel E.; Warren, Christopher; Xu, Xueyan S.; McDowell, Thomas W.; Wu, John Z.

    2015-01-01

    The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study. PMID:26929824

  5. Fluid dynamic factors in tracheal pressure measurement.

    PubMed

    Chang, H K; Mortola, J P

    1981-07-01

    Because tracheal pressure measurement generally involves the use of a cannula or an endotracheal tube, fluid dynamic factors may cause a considerable artifact. We present a theoretical explanation of the observed apparent paradox in which the resistance of a tracheal cannula or an endotracheal tube is isolation was found to exceed the resistance of the airways plus the cannula or the tube in situ. By estimating the viscous dissipation and the kinetic energy change in a conduit with sudden variation of cross-sectional area, a predictive model is derived. The predictions are verified by a series of in vitro experiments with both steady and oscillatory flows. The experiments showed that the pressure recorded from the sidearm of a tracheal cannula or endotracheal tube contains an error which, in general, increased with the mean Reynolds' number of the through flow and also depends on the diameter ratio between the trachea and the tube or cannula, the position of the pressure tap, and the frequency of ventilation. When feasible, direct measurement with a needle in the trachea is suggested as a way to avoid the possible artifacts arising from the use fo a side tap of the cannula. Theoretical considerations, as well as in vitro and animal experiments, indicate that adding a properly chosen expansion to the tracheal cannula makes it possible to alter inspiratory and expiratory pressures selectively. This device may prove useful in control of breathing studies. PMID:7263418

  6. Using a co-ordinate measuring machine to align multiple element large optical systems

    NASA Astrophysics Data System (ADS)

    Howick, Eleanor F.; Cochrane, David; Meier, David

    2007-09-01

    A high precision Co-ordinate Measuring Machine (CMM) is an ideal instrument for aligning mid to large (400 to 600 mm) diameter multiple element lens assemblies. The CMM has many advantages over simpler dial gauge and rotary table setups. For example, these traditional methods do not necessarily make it easy to separate the out-of-roundness of a lens or its mounting cell, from a misalignment of the lens and cell. With a CMM, the 'as made' geometry of both the lenses and their mounting cells can be determined before the mounting and alignment process begins. By considering the actual shape of the lenses and cells, adjustments can be made during the alignment process to ensure that the complete assembly meets the designer's tolerances. This paper discusses CMM alignment techniques used and experience gained while assembling large lens corrector assemblies (for example, the three element Prime Focus Unit for FMOS, the Subaru Fibre Multi-Object Spectrograph) destined for installation in astronomical telescopes.

  7. Determination of the auroral O/1S/ production sources from coordinated rocket and satellite measurements

    NASA Technical Reports Server (NTRS)

    Sharp, W. E.; Torr, D. G.

    1979-01-01

    This paper examines the auroral excitation mechanisms using data collected in a satellite/rocket/aurora coordination. Past theories considered that variation with altitude of the emission from the O(1S) state is the same as that from the N2(+) first negative band system. Actually, the source function for O(1S) does not covary with N2(+) but has a smaller scale height. The covariation is due to quenching of the source function by O(3P). The steadiness of the aurora in a flight of the Michigan Airglow Payload allows the profile to be differentiated for direct comparison with theory. It is concluded that when most of the relevant variables for production of the O(1S) state are simultaneously measured in aurora, the major source functions are dissociative recombination of O2(+) above 210 km to apogee at 250 km, and below 180 km the energy transfer from N2(A3sigma) in the oxygen atom quenching reaction.

  8. Beyond the Niche: Tissue-Level Coordination of Stem Cell Dynamics

    PubMed Central

    O’Brien, Lucy Erin; Bilder, David

    2014-01-01

    Adult animals rely on populations of stem cells to ensure organ function throughout their lifetime. Stem cells are governed by signals from stem cell niches, and much is known about how single niches promote stemness and direct stem cell behavior. However, most organs contain a multitude of stem cell–niche units, which are often distributed across the entire expanse of the tissue. Beyond the biology of individual stem cell–niche interactions, the next challenge is to uncover the tissue-level processes that orchestrate spatial control of stem-based renewal, repair, and remodeling throughout a whole organ. Here we examine what is known about higher order mechanisms for interniche coordination in epithelial organs, whose simple geometry offers a promising entry point for understanding the regulation of niche number, distribution, and activity. We also consider the potential existence of stem cell territories and how tissue architecture may influence niche coordination. PMID:23937350

  9. Hydrothermal alteration and diagenesis of terrestrial lacustrine pillow basalts: Coordination of hyperspectral imaging with laboratory measurements

    NASA Astrophysics Data System (ADS)

    Greenberger, Rebecca N.; Mustard, John F.; Cloutis, Edward A.; Mann, Paul; Wilson, Janette H.; Flemming, Roberta L.; Robertson, Kevin M.; Salvatore, Mark R.; Edwards, Christopher S.

    2015-12-01

    We investigate an outcrop of ∼187 Ma lacustrine pillow basalts of the Talcott Formation exposed in Meriden, Connecticut, USA, focusing on coordinated analyses of one pillow lava to characterize the aqueous history of these basalts in the Hartford Basin. This work uses a suite of multidisciplinary measurements, including hyperspectral imaging, other spectroscopic techniques, and chemical and mineralogical analyses, from the microscopic scale up to the scale of an outcrop. The phases identified in the sample are albite, large iron oxides, and titanite throughout; calcite in vesicles; calcic clinopyroxene, aegirine, and Fe/Mg-bearing clay in the rind; and fine-grained hematite and pyroxenes in the interior. Using imaging spectroscopy, the chemistry and mineralogy results extend to the hand sample and larger outcrop. From all of the analyses, we suggest that the pillow basalts were altered initially after emplacement, either by heated lake water or magmatic fluids, at temperatures of at least 400-600 °C, and the calcic clinopyroxenes and aegirine identified in the rind are a preserved record of that alteration. As the hydrothermal system cooled to slightly lower temperatures, clays formed in the rind, and, during this alteration, the sample oxidized to form hematite in the matrix of the interior and Fe3+ in the pyroxenes in the rind. During the waning stages of the hydrothermal system, calcite precipitated in vesicles within the rind. Later, diagenetic processes albitized the sample, with albite replacing plagioclase, lining vesicles, and accreting onto the exterior of the sample. This albitization or Na-metasomatism occurred when the lake within the Hartford Basin evaporated during a drier past climatic era, resulting in Na-rich brines. As Ca-rich plagioclase altered to albite, Ca was released into solution, eventually precipitating as calcite in previously-unfilled vesicles, dominantly in the interior of the pillow. Coordinated analyses of this sample permit

  10. Mars 2001 Lander Mission: Measurement Synergy Through Coordinated Operations Planning and Implementation

    NASA Astrophysics Data System (ADS)

    Arvidson, R.

    1999-01-01

    exposed at the site, together with quantitative information on material mineralogy, chemistry, and physical properties (rock textures; soil grain size and shape distributions; degree and nature of soil induration; soil magnetic properties). Observations from the APEX, MECA, and MIP Experiments, including use of the robotic arm robotic arm camera (RAC) and the Marie Curie rover, will be used to address these parameters in a synergistic way. Further, calibration targets on APEX will provide radiometric and mineralogical control surfaces, and magnet targets will allow observations of magnetic phases. Patch plates on MECA will be imaged to determine adhesive and abrasive properties of soils. Coordinated mission planning is crucial for optimizing the measurement synergy among the packages included on the lander. This planning has already begun through generation of multi-sol detailed operations activities.

  11. Measuring mandibular asymmetry in Class I normal subjects using 3D novel coordinate system

    PubMed Central

    Kheir, Nadia Abou; Kau, Chung How

    2014-01-01

    Introduction: Orthodontic treatment plays a major role in cosmetic dentistry. A harmonious facial balance is normally the end point in comprehensive orthodontic outcomes. In order to achieve this goal, correct diagnosis of asymmetry should be done starting from the outer facial morphology forms and progressively moving to the dental occlusion. The prime importance of measuring mandibular asymmetry is its tremendous effect on the occlusion. Objective: The aim of this study was to measure mandibular asymmetry in a cohort Class I molar relationship comparing right and left sides using new three-dimensions (3D) imaging technique with the aid of 3D software (in vivo 5.2.3 [San Jose, CA]). Materials and Methods: 35 DICOM files were initially collected retrospectively and seven were excluded due to (1) condylar resorption, (2) history of trauma and (3) unclear DICOM file. A new coordinate system was set for the mid-sagittal plane (MSP), Frankfort horizontal plane and frontal plane (FP). Each cone beam computed tomography (CBCT) was appraised using 16 evaluation criteria bilaterally. Five mandibular landmarks were selected: Condylion_R, Gonion_R, Menton, Gonion_L and Condylion_L. Using these points, the mandible was further divided into four parts: (1) Ramus length right side, body of the mandible right side, body of the Ramus left side and Ramus length left side. The angles between each line and the three different planes were acquired in order to compare each line from a 3D aspect. Mean and standard deviation were calculated for the 28 CBCTs. Results: Significant bilateral differences were reported in the angle between the ramus length and MSP and the ramus length and the FP (P < 0.05). Significant lateroanterior shift of the mandibular ramus on the left side in comparison with the right side. Conclusion: Viewing an object using three different angles between the four parts of the mandible and each plane is a valid method to replicate the actual object. PMID:24987596

  12. Mars 2001 Lander Mission: Measurement Synergy through Coordinated Operations Planning and Implementation

    NASA Astrophysics Data System (ADS)

    Arvidson, R.; Bell, J. F., III; Kaplan, D.; Marshall, J.; Mishkin, A.; Saunders, S.; Smith, P.; Squyres, S.

    1999-03-01

    The Science Operations Working Group, Mars 2001 Mission, has developed coordinated plans for scientific observations that treat the instruments as an integrated payload. This approach ensures maximum return of scientific information.

  13. Statistics of dynamic speckles in application to distance measurements

    NASA Astrophysics Data System (ADS)

    Kamshilin, Alexei A.; Miridonov, Serguei V.; Sidorov, Igor S.; Semenov, Dmitry V.; Nippolainen, Ervin

    2009-03-01

    We present an analysis of statistical properties of dynamic speckles to estimate the limiting accuracy of measurements achievable in a distance sensor using spatially filtered dynamic speckles. The main reason for inaccurate measurements using dynamic speckles is their stochastic nature. It is shown that the average lifetime of dynamic speckles is the key factor defining the measurement accuracy. Main conclusions of the theoretical analysis were confirmed in an experiment carried out with a fast moving rough surface. Special attention is paid to a recently proposed range sensor using dynamic speckles generated by a fast-deflecting laser beam. It is shown that this sensor possesses the best combination of accuracy and response time.

  14. Coordination in the dynamics of the brain as inferred from EEG analysis.

    PubMed

    Pravitha, R; Nampoori, V P N

    2002-10-01

    The present study observed the coordination between cortical areas during no task conditions as well as for the pathological condition of epilepsy, by application of the phase synchronization technique to the EEG signal in a multichannel recording. The index obtained from the phase entrainment investigation was properly scaled by a novel method to take into account the effect of nearest neighbor interactions. This scaled index was analyzed temporally to learn about the behavior of regional interactions in time. The results obtained not only corroborate earlier known results, but also give deeper insight into actual brain functioning. PMID:12587525

  15. Thomson Scattering Measurements of Plasma Dynamics

    SciTech Connect

    Holl, A; Redmer, R; Tschentscher, T; Toleikis, S; Forster, E; Cao, L; Glenzer, S H; Neumayer, P

    2006-03-29

    The authors propose to investigate the dynamics of plasmas in the warm dense matter (WDM) regime on ultra-short time scales. Accessible plasma conditions are in the density range of n = 10{sup 20} - 10{sup 23} cm{sup -3} and at moderate temperatures of T = 1 - 20 eV. These plasmas are of importance for laboratory astrophysics, high energy density science and inertial confinement fusion. They are characterized by a coupling parameter of {Lambda} {approx}> 1, where electromagnetic interactions are of the same order as the kinetic energy. The high density of the plasma makes it opaque to radiation in the visible range and, as a consequence, UV up to x-ray radiation can be used to probe such systems. Therefore a wide range in the temperature-density plane of WDM is presently unexplored and only the VUV-FEL opens for the first time the opportunity for its detailed investigation. In equilibrium, the macroscopic state of the plasma is completely characterized by its density and temperature. In pump-probe experiments however, the plasma is initially in a nonequilibrium state and relaxes towards equilibrium within the relaxation time {tau}{sub R}. For t > {tau}{sub R}, the plasma is in an equilibrium state and expands hydrodynamically on a time scale {tau}{sub H}. The proposed experiment measures the time-resolved Thomson scattering signal with the VUV-FEL radiation characterizing the plasma in equilibrium and nonequilibrium states. Both regimes are extremely interesting and will provide new insight into the following phenomena: (1) details of nonequilibrium correlations, (2) relaxation phenomena, (3) hydrodynamic expansion, (4) recombination kinetics. The time-resolved Thomson scattering signal is obtained in a pump-probe experiment by varying the delay between pump and probe. The final stage of the relaxation process (t {approx} {tau}{sub R}) is of special interest since the plasma components (electrons and ion species) can be assumed to be in quasi-equilibrium. This

  16. A theoretical and experimental study on no-guide light pen type 3D-coordinate measurement system

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaofang; Yu, Xin; Jiang, Chengzhi; Wang, Baoguang

    2003-04-01

    A novel no-guide light pen type 3D-coordinate measurement system with three sets of position sensitive devices (PSDs) to realize intersection converge imaging is introduced. It is called as the light pen type measurement system, because the measuring head is shaped as a pen with several light sources on it. The structure design, measurement principle and experimental results are presented. The theoretical analysis and experimental results prove that this system has advanced features of simple structure, high automation, and high accuracy, and can be used in the measurement fields of mechanical manufacture, robot, auto, aviation and medicine effectively.

  17. Measuring Word Learning: Dynamic versus Static Assessment of Kindergarten Vocabulary

    ERIC Educational Resources Information Center

    Burton, Vera Joanna; Watkins, Ruth V.

    2007-01-01

    This preliminary study investigated the potential of using a dynamic approach to assessing expressive word mapping. Because measuring word mapping with productive language responses is much more difficult than measuring receptive word mapping, incorporating a dynamic measure allowed us to tap partial mapping and provided useful information on word…

  18. Usage of I++ Simulator to Program Coordinate Measuring Machines when Common Programming Methods are difficult to apply

    NASA Astrophysics Data System (ADS)

    Gąska, A.; Szewczyk, D.; Gąska, P.; Gruza, M.; Sładek, J.

    2014-02-01

    Nowadays, simulators facilitate tasks performed daily by the engineers of different branches, including coordinate metrologists. Sometimes it is difficult or almost impossible to program a Coordinate Measuring Machine (CMM) using standard methods. This happens, for example, during measurements of nano elements or in cases when measurements are performed on high-precision (accurate) measuring machines which work in strictly air-conditioned spaces and the presence of the operator in such room during the programming of CMM could cause an increase in temperature, which in turn could make it necessary to wait some time until conditions stabilize. This article describes functioning of a simulator and its usage during Coordinate Measuring Machine programming in the latter situation. Article also describes a general process of programming CMMs which ensures the correct machine performance after starting the program on a real machine. As an example proving the presented considerations, measurement of exemplary workpiece, which was performed on the machine working in the strictly air-conditioned room, was described

  19. Rotor/bearing system dynamic stiffness measurements

    NASA Technical Reports Server (NTRS)

    Muszynska, A.

    1985-01-01

    Sweep perturbation testing as used in Modal Analysis when applied to a rotating machine has to take into consideration the machine dynamic state of equilibrium at its operational rotative speed. This stands in contrasts to a static equilibrium of nonrotating structures. The rotational energy has a significant influence on rotor dynamic characteristics. The best perturbing input for rotating machines is a forward or reverse rotating, circular force applied directly to the shaft. Determination of Dynamic Stiffness Characteristics of the rotor bearing system by nonsynchronous perturbation of a symmetric rotating shaft supported in one relatively rigid and one oil lubricated bearing.

  20. Coordinated Observations of X-ray and High-resolution EUV Active Region Dynamics

    NASA Technical Reports Server (NTRS)

    Savage, Sabrina

    2013-01-01

    The recently-launched High-resolution Coronal imager (Hi-C) sounding rocket provided the highest resolution images of coronal loops and other small-scale structures in the 193 Angstrom passband to date. With just 5 minutes of observations, the instrument recorded a variety of dynamic coronal events -- including even a small B-class flare. We will present our results comparing these extreme-ultraviolet (EUV) observations with X-ray imaging from Hinode/XRT as well as EUV AIA data to identify sources of hot plasma rooted in the photosphere and track their affect on the overall topology and dynamics of the active region.

  1. Coordinated Observations of X-ray and High-Resolution EUV Active Region Dynamics

    NASA Technical Reports Server (NTRS)

    Savage, Sabrina; Cirtain, Jonathan; Winebarger, Amy; Kobayashi, Ken; Golub, Leon; Korreck, Kelly

    2013-01-01

    The recently-launched High-resolution Coronal imager (Hi-C) sounding rocket provided the highest resolution images of coronal loops and other small-scale structures in the 193 Angstrom passband to date. With just 5 minutes of observations, the instrument recorded a variety of dynamic coronal events -- including even a small B-class flare. We will present our results comparing these extreme-ultraviolet (EUV) observations with X-ray imaging from Hinode/XRT as well as EUV AIA data to identify sources of hot plasma rooted in the photosphere and track their affect on the overall topology and dynamics of the active region.

  2. Coordination of Molecular Motors: From in vitro Assays to Intracellular Dynamics

    PubMed Central

    Holzbaur, Erika L.F.; Goldman, Yale E.

    2010-01-01

    Summary New technologies have emerged that enable the tracking of molecular motors and their cargos with very high resolution both in vitro and in live cells. Classic in vitro motility assays are being supplemented with assays of increasing complexity that more closely model the cellular environment. In cells, the introduction of probes such as quantum dots allows the high resolution tracking of both motors and vesicular cargos. The “bottom up” enhancement of in vitro assays and the “top down” analysis of motility inside cells are likely to converge over the next few years. Together, these studies are providing new insights into the coordination of motors during intracellular transport. PMID:20102789

  3. Stable reduced-order models of generalized dynamical systems using coordinate-transformed Arnoldi algorithms

    SciTech Connect

    Silveira, L.M.; Kamon, M.; Elfadel, I.; White, J.

    1996-12-31

    Model order reduction based on Krylov subspace iterative methods has recently emerged as a major tool for compressing the number of states in linear models used for simulating very large physical systems (VLSI circuits, electromagnetic interactions). There are currently two main methods for accomplishing such a compression: one is based on the nonsymmetric look-ahead Lanczos algorithm that gives a numerically stable procedure for finding Pade approximations, while the other is based on a less well characterized Arnoldi algorithm. In this paper, we show that for certain classes of generalized state-space systems, the reduced-order models produced by a coordinate-transformed Arnoldi algorithm inherit the stability of the original system. Complete Proofs of our results will be given in the final paper.

  4. Motion in cylindrical coordinates: applications to J2 gravity perturbed trajectories of space dynamics

    NASA Astrophysics Data System (ADS)

    Sharaf, M. A.; Selim, H. H.

    2011-05-01

    In this paper, a computational algorithm for the initial value problem of J2 gravity perturbed trajectories in cylindrical coordinates will be established. Applications of the algorithm for the problem of the final state prediction are illustrated by numerical examples of eight test orbits of different eccentricities. The numerical results are highly accurate and efficient in predicting J2 final state for gravity perturbed trajectories which is of great importance for scientific researches. Moreover, an additional efficiency of the algorithm is that one can reach the accuracy of one cm using at most 70% of the number of steps that used for obtaining the reference final state solution. By this reduction, the step size becomes larger, hence minimizing the computational errors.

  5. Outcome measures for hand function naturally reveal three latent domains in older adults: strength, coordinated upper extremity function, and sensorimotor processing

    PubMed Central

    Lawrence, Emily L.; Dayanidhi, Sudarshan; Fassola, Isabella; Requejo, Philip; Leclercq, Caroline; Winstein, Carolee J.; Valero-Cuevas, Francisco J.

    2015-01-01

    Understanding the mapping between individual outcome measures and the latent functional domains of interest is critical to a quantitative evaluation and rehabilitation of hand function. We examined whether and how the associations among six hand-specific outcome measures reveal latent functional domains in elderly individuals. We asked 66 healthy older adult participants (38F, 28M, 66.1 ± 11.6 years, range: 45–88 years) and 33 older adults (65.8 ± 9.7 years, 44–81 years, 51 hands) diagnosed with osteoarthritis (OA) of the carpometacarpal (CMC) joint, to complete six functional assessments: hand strength (Grip, Key and Precision Pinch), Box and Block, Nine Hole Pegboard, and Strength-Dexterity tests. The first three principal components suffice to explain 86% of variance among the six outcome measures in healthy older adults, and 84% of variance in older adults with CMC OA. The composition of these dominant associations revealed three distinct latent functional domains: strength, coordinated upper extremity function, and sensorimotor processing. Furthermore, in participants with thumb CMC OA we found a blurring of the associations between the latent functional domains of strength and coordinated upper extremity function. This motivates future work to understand how the physiological effects of thumb CMC OA lead upper extremity coordination to become strongly associated with strength, while dynamic sensorimotor ability remains an independent functional domain. Thus, when assessing the level of hand function in our growing older adult populations, it is particularly important to acknowledge its multidimensional nature—and explicitly consider how each outcome measure maps to these three latent and fundamental domains of function. Moreover, this ability to distinguish among latent functional domains may facilitate the design of treatment modalities to target the rehabilitation of each of them. PMID:26097455

  6. Penta- and hexa-coordinate ferric hemoglobins display distinct pH titration profiles measured by Soret peak shifts.

    PubMed

    Uppal, Sheetal; Kumar, Amit; Shandilya, Manish; Mukhi, Nitika; Singh, Amit Kumar; Kateriya, Suneel; Kaur, Jagreet; Kundu, Suman

    2016-10-01

    Hemoglobins with diverse characteristics have been identified in all kingdoms of life. Their ubiquitous presence indicates that these proteins play important roles in physiology, though function for all hemoglobins are not yet established with certainty. Their physiological role may depend on their ability to bind ligands, which in turn is dictated by their heme chemistry. However, we have an incomplete understanding of the mechanism of ligand binding for these newly discovered hemoglobins and the measurement of their kinetic parameters depend on their coordination at the heme iron. To gain insights into their functional role, it is important to categorize the new hemoglobins into either penta- or hexa-coordinated varieties. We demonstrate that simple pH titration and absorbance measurements can determine the coordination state of heme iron atom in ferric hemoglobins, thus providing unambiguous information about the classification of new globins. This method is rapid, sensitive and requires low concentration of protein. Penta- and hexa-coordinate hemoglobins displayed distinct pH titration profiles as observed in a variety of hemoglobins. The pentacoordinate distal histidine mutant proteins of hexacoordinate hemoglobins and ligand-bound hexacoordinate forms of pentacoordinate hemoglobins reverse the pH titration profiles, thus validating the sensitivity of this spectroscopic technique. PMID:27449132

  7. Coordinated Approaches to Quantify Long-Term Ecosystem dynamics in Response to Global Change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate change and its impact on ecosystems are usually assessed at decadal and century time scales. Ecological responses to climate change at those scales are strongly regulated by long-term processes, such as changes in species composition, carbon dynamics in soil and by big trees, and nutrient r...

  8. Numbers and Measuring, Learning With TOR: MINNEMAST Coordinated Mathematics - Science Series, Unit 16.

    ERIC Educational Resources Information Center

    Vogt, Elaine E., Ed.

    This volume is the sixteenth in a series of 29 coordinated MINNEMAST units in mathematics and science for kindergarten and the primary grades. Intended for use by second-grade teachers, this unit guide provides a summary and overview of the unit, a list of materials needed, and descriptions of five groups of lessons. The purposes and procedures…

  9. Coordinated power control of unified power flow controller and its application for enhancing dynamic power system performance

    NASA Astrophysics Data System (ADS)

    Fang, Wanliang

    This thesis focuses on reporting my research study on a problem area relating to use of Unified Power Flow Controller (UPFC) for coordinating load flow in power systems so as to enhance their static and dynamic performance by having more secure and economical operation and higher dynamic stability margin. UPFC is considered as one of the most promising devices for implementing the Flexible AC Transmission System (FACTS) concept. Although development of UPFC is still on an infant stage, probing into its impact on power system operation is actively pursued and significant effort has been devoted to put it forward as a practical FACTS device and as a challenging academic research object. In order to consider UPFC as a basic power system element, it has to be involved in associated load flow computation essentially for power system control analysis and operational planning. An up front problem for design engineers is therefore pointing to a need to modify existing load flow program so as to accommodate interactions of UPFCs. A lot of research output start coming out but their computational efficiency are not high enough. In this regard, I propose two methods to perform the UPFC embedded load flow calculation to cater for two different types of application. The first one caters for analyzing direct control of load flow on transmission lines with embedded UPFCs. In this type of problem, active and reactive power of the lines, as well as the magnitude of bus voltages are priori given. The load flow solution can then be obtained and enables the UPFC parameters to be determined with a significantly improved computational efficiency. The second one works in contrary to the first one by which parameters of UPFCs are given before hand and the load flow calculation is performed for conforming a feasible operation. It can be regarded as an indirect load flow control calculation which is useful in planning stage for incorporating UPFC into existing system and/or carrying out

  10. Dynamic Forces in Spur Gears - Measurement, Prediction, and Code Validation

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Townsend, Dennis P.; Rebbechi, Brian; Lin, Hsiang Hsi

    1996-01-01

    Measured and computed values for dynamic loads in spur gears were compared to validate a new version of the NASA gear dynamics code DANST-PC. Strain gage data from six gear sets with different tooth profiles were processed to determine the dynamic forces acting between the gear teeth. Results demonstrate that the analysis code successfully simulates the dynamic behavior of the gears. Differences between analysis and experiment were less than 10 percent under most conditions.

  11. Evolutionary dynamics on measurable strategy spaces: Asymmetric games

    NASA Astrophysics Data System (ADS)

    Mendoza-Palacios, Saul; Hernández-Lerma, Onésimo

    2015-12-01

    The theory of evolutionary dynamics in asymmetric games has been mainly studied for games with a finite strategy space. In this paper we introduce an evolutionary dynamics model for asymmetric games where the strategy sets are measurable spaces (separable metric spaces). Under this hypothesis the replicator dynamics is in a Banach Space. We specify conditions under which the replicator dynamics has a solution. Furthermore, under suitable assumptions, a critical point of the system is stable. Finally, an example illustrates our results.

  12. Flexible dynamic measurement method of three-dimensional surface profilometry based on multiple vision sensors.

    PubMed

    Liu, Zhen; Li, Xiaojing; Li, Fengjiao; Zhang, Guangjun

    2015-01-12

    Single vision sensor cannot measure an entire object because of their limited field of view. Meanwhile, multiple rigidly-fixed vision sensors for the dynamic vision measurement of three-dimensional (3D) surface profilometry are complex and sensitive to strong environmental vibrations. To overcome these problems, a novel flexible dynamic measurement method for 3D surface profilometry based on multiple vision sensors is presented in this paper. A raster binocular stereo vision sensor is combined with a wide-field camera to produce a 3D optical probe. Multiple 3D optical probes are arranged around the object being measured, then many planar targets are set up. These planar targets function as the mediator to integrate the local 3D data measured by the raster binocular stereo vision sensors into the coordinate system. The proposed method is not sensitive to strong environmental vibrations, and the positions of these 3D optical probes need not be rigidly-fixed during the measurement. The validity of the proposed method is verified in a physical experiment with two 3D optical probes. When the measuring range of raster binocular stereo vision sensor is about 0.5 m × 0.38 m × 0.4 m and the size of the measured object is about 0.7 m, the accuracy of the proposed method could reach 0.12 mm. Meanwhile, the effectiveness of the proposed method in dynamic measurement is confirmed by measuring the rotating fan blades. PMID:25835684

  13. Suppressing Respiration Effects when Geometric Distortion Is Corrected Dynamically by Phase Labeling for Additional Coordinate Encoding (PLACE) during Functional MRI

    PubMed Central

    Faraji-Dana, Zahra; Tam, Fred; Chen, J. Jean; Graham, Simon J.

    2016-01-01

    Echo planar imaging (EPI) suffers from geometric distortions caused by magnetic field inhomogeneities, which can be time-varying as a result of small amounts of head motion that occur over seconds and minutes during fMRI experiments, also known as “dynamic geometric distortion”. Phase Labeling for Additional Coordinate Encoding (PLACE) is a promising technique for geometric distortion correction without reduced temporal resolution and in principle can be used to correct for motion-induced dynamic geometric distortion. PLACE requires at least two EPI images of the same anatomy that are ideally acquired with no variation in the magnetic field inhomogeneities. However, head motion and lung ventilation during the respiratory cycle can cause changes in magnetic field inhomogeneities within the EPI pair used for PLACE. In this work, we exploited dynamic off-resonance in k-space (DORK) and averaging to correct the within EPI pair magnetic field inhomogeneities; and hence proposed a combined technique (DORK+PLACE+averaging) to mitigate dynamic geometric distortion in EPI-based fMRI while preserving the temporal resolution. The performance of the combined DORK, PLACE and averaging technique was characterized through several imaging experiments involving test phantoms and six healthy adult volunteers. Phantom data illustrate reduced temporal standard deviation of fMRI signal intensities after use of combined dynamic PLACE, DORK and averaging compared to the standard processing and static geometric distortion correction. The combined technique also substantially improved the temporal standard deviation and activation maps obtained from human fMRI data in comparison to the results obtained by standard processing and static geometric distortion correction, highlighting the utility of the approach. PMID:27258194

  14. Inner and Outer Coordination Shells of Mg(2+) in CorA Selectivity Filter from Molecular Dynamics Simulations.

    PubMed

    Kitjaruwankul, Sunan; Wapeesittipan, Pattama; Boonamnaj, Panisak; Sompornpisut, Pornthep

    2016-01-28

    Structural data of CorA Mg(2+) channels show that the five Gly-Met-Asn (GMN) motifs at the periplasmic loop of the pentamer structure form a molecular scaffold serving as a selectivity filter. Unfortunately, knowledge about the cation selectivity of Mg(2+) channels remains limited. Since Mg(2+) in aqueous solution has a strong first hydration shell and apparent second hydration sphere, the coordination structure of Mg(2+) in a CorA selectivity filter is expected to be different from that in bulk water. Hence, this study investigated the hydration structure and ligand coordination of Mg(2+) in a selectivity filter of CorA using molecular dynamics (MD) simulations. The simulations reveal that the inner-shell structure of Mg(2+) in the filter is not significantly different from that in aqueous solution. The major difference is the characteristic structural features of the outer shell. The GMN residues engage indirectly in the interactions with the metal ion as ligands in the second shell of Mg(2+). Loss of hydrogen bonds between inner- and outer-shell waters observed from Mg(2+) in bulk water is mostly compensated by interactions between waters in the first solvation shell and the GMN motif. Some water molecules in the second shell remain in the selectivity filter and become less mobile to support the metal binding. Removal of Mg(2+) from the divalent cation sensor sites of the protein had an impact on the structure and metal binding of the filter. From the results, it can be concluded that the GMN motif enhances the affinity of the metal binding site in the CorA selectivity filter by acting as an outer coordination ligand. PMID:26727882

  15. Leading-process actomyosin coordinates organelle positioning and adhesion receptor dynamics in radially migrating cerebellar granule neurons

    SciTech Connect

    Trivedi, Niraj; Ramahi, Joseph S.; Karakaya, Mahmut; Howell, Danielle; Kerekes, Ryan A.; Solecki, David J.

    2014-12-02

    During brain development, neurons migrate from germinal zones to their final positions to assemble neural circuits. A unique saltatory cadence involving cyclical organelle movement (e.g., centrosome motility) and leading-process actomyosin enrichment prior to nucleokinesis organizes neuronal migration. While functional evidence suggests that leading-process actomyosin is essential for centrosome motility, the role of the actin-enriched leading process in globally organizing organelle transport or traction forces remains unexplored. Our results show that myosin ii motors and F-actin dynamics are required for Golgi apparatus positioning before nucleokinesis in cerebellar granule neurons (CGNs) migrating along glial fibers. Moreover, we show that primary cilia are motile organelles, localized to the leading-process F-actin-rich domain and immobilized by pharmacological inhibition of myosin ii and F-actin dynamics. Finally, leading process adhesion dynamics are dependent on myosin ii and F-actin. In conclusion, we propose that actomyosin coordinates the overall polarity of migrating CGNs by controlling asymmetric organelle positioning and cell-cell contacts as these cells move along their glial guides.

  16. Leading-process actomyosin coordinates organelle positioning and adhesion receptor dynamics in radially migrating cerebellar granule neurons

    DOE PAGESBeta

    Trivedi, Niraj; Ramahi, Joseph S.; Karakaya, Mahmut; Howell, Danielle; Kerekes, Ryan A.; Solecki, David J.

    2014-12-02

    During brain development, neurons migrate from germinal zones to their final positions to assemble neural circuits. A unique saltatory cadence involving cyclical organelle movement (e.g., centrosome motility) and leading-process actomyosin enrichment prior to nucleokinesis organizes neuronal migration. While functional evidence suggests that leading-process actomyosin is essential for centrosome motility, the role of the actin-enriched leading process in globally organizing organelle transport or traction forces remains unexplored. Our results show that myosin ii motors and F-actin dynamics are required for Golgi apparatus positioning before nucleokinesis in cerebellar granule neurons (CGNs) migrating along glial fibers. Moreover, we show that primary cilia aremore » motile organelles, localized to the leading-process F-actin-rich domain and immobilized by pharmacological inhibition of myosin ii and F-actin dynamics. Finally, leading process adhesion dynamics are dependent on myosin ii and F-actin. In conclusion, we propose that actomyosin coordinates the overall polarity of migrating CGNs by controlling asymmetric organelle positioning and cell-cell contacts as these cells move along their glial guides.« less

  17. Biomolecular folding rates as understood from single-reaction-coordinate Langevin dynamics and Kramers' theory

    NASA Astrophysics Data System (ADS)

    Kabir, Md Adnan

    Langevin dynamics was used to model the folding and unfolding of simple, hairpin-like biomolecules whose ends are attached to laser-trapped beads, as occurs in optical tweezers experiments. The Langevin process was evolved numerically, using parameters motivated by real experimental systems. Folding trajectories were generated and analyzed to extract the folding rate as a function of the force applied to the beads. The observed rate was compared to the analytical predictions of Kramers' theory. Strong discrepancies were noted. The failure of the Kramers' theory was attributed to the slow dynamical response of the beads, which it does not account for. The results of this work highlight the necessity to include in the modeling the experimental systems that mediate force along the length of the biomolecule.

  18. Integration of dynamic information for visuomotor control in young adults with developmental coordination disorder.

    PubMed

    de Oliveira, Rita F; Wann, John P

    2010-09-01

    We examined the hypothesis that developmental coordination disorder (DCD) consists of a poor integration of distal preparatory visual information with the visual information that arises during movement execution. We set up a steering task where the action goal was to steer smoothly on a virtual winding course under conditions that manipulated the availability and timing of visual information. Participants were 20 young adults who had been diagnosed with DCD in their childhood and 20 typically developing age-matched controls. On a simple tracking task, participants with DCD were slower and more variable than controls. The group differences dissipated, however, when the display highlighted the directional changes necessary within the next 500 ms. When the latter condition was modified to also include the full layout of the course, however, the performance of the DCD group once again decreased. This result could not be attributed to a simple distraction effect. The results suggest that distinct neural mechanisms are associated with the processing of fast visual information for online control and longer-term action preparation based on spatial layout. In skilled action, cerebellar and parietal areas process information effectively and their outputs are integrated into one smooth movement. Because the DCD group showed difficulties in steering when both types of information were present, it is likely that this integration is suboptimal. PMID:20677003

  19. Magnetosheath Coordinates

    NASA Astrophysics Data System (ADS)

    Schulz, M.; Chen, M. W.

    2010-12-01

    The eventual goal of this work is to develop an approximate analytical representation of solar-wind streamlines in the magnetosheath surrounding a magnetosphere of rather general shape. Previous analytical representations of magnetosheath streamlines and magnetic fields have invoked magnetopause shapes that conform to standard coordinate systems (e.g., spherical, cylindrical, paraboloidal, ellipsoidal), but it seems now that such a restriction on magnetopause shape is unnecessary. In the present work it is assumed only that the magnetopause is a continuously differentiable convex surface axisymmetric about the Sun-Earth line. This geometry permits the construction of an orthogonal coordinate system (mu, eta, chi) such that eta is the cosine of the cone angle between the Sun-Earth line and any conical surafce extending normally outward from the magnetopause, mu is a measure of the perpendicular distance of any magnetosheath point from the magnetopause, and chi is an azimuthal coordinate measured around the Sun-Earth line. It is convenient here to assign a label mu = mu* to the magnetopause itself, so that mu - mu* denotes perpendicular distance from the magnetopause and mu* is an adjustable parameter roughly comparable to the radius of the magnetotail. This choice provides for a rough correspondence between the (mu, eta, chi) coordinates introduced here and the ellipsoidal coordinates used in our previous efforts at magnetosheath modeling.

  20. Effects of coordinate system choice on measured regional myocardial function in short axis cine electron-beam tomography

    SciTech Connect

    Reed, J.; Rumberger, J.; Buithieu, J.; Behrenbeck, T.; Breen, J.; Sheedy, P. II

    1995-12-31

    Following myocardial infarction, the size of the infarcted region and the systolic functioning of the non-infarcted region are commonly assessed by various cross-sectional imaging techniques. For the assessment of patterns of ventricular contraction, images are commonly acquired of ventricular cross-sections normal to the long axis of the heart and parallel to the mitral valve plane. The endocardial and epicardial surfaces of the myocardium are identified. Then the ventricle is divided into sectors and the volumes of blood and myocardium within each sector at multiple phases of the cardiac cycle are measured. Regional function parameters are derived from these measurements. This generally mandates the use of a polar or cylindrical coordinate system. Various algorithms have been used to select the origin of this coordinate system. These include the centroid of the endocardial surface, the epicardial surface, or of a polygon whose vertices lie midway between the epicardial and endocardial surfaces of the myocardium (centerline method). Another algorithm has been developed in the laboratory. This uses the centroid (or center of mass) of the myocardium exclusive of the ventricular cavity.Each of these choices for origin of coordinate system can be derived from the end-diastolic image or from the end-systolic image. Alternately, new coordinate system can be selected for each phase of the cardiac cycle. These are referred to as floating coordinate systems. A series of computer models have been developed in the laboratory to study the effects of each of these choices on the regional function parameters of normal ventricles and how these choices effect the quantification of regional abnormalities after myocardial infarction.

  1. Evaluation of a dual beam laser Doppler displacement meter retrofitted to a coordinate measuring machine. Final report

    SciTech Connect

    Ramsdale, S.J.; Hanshaw, R.A.

    1997-05-01

    A dual beam laser Doppler displacement measuring system was mounted to a fixed-table, cantilever-type coordinate measuring machine (CMM) to establish the feasibility of real time angular error correction for each CMM axis. The performance improvement was evaluated relative to the CMM`s standard scales. The dual beam system proved to have no advantage over a single beam laser due to an inability to measure the actual angular errors at the probe location, but showed potential for substantial accuracy improvement over the standard CMM scales when geometry errors were software corrected.

  2. System for measuring the coordinates of tire surfaces in transient conditions when rolling over obstacles: Description of the system and performance analysis

    SciTech Connect

    Castellini, Paolo; Di Giuseppe, Andrea

    2008-06-15

    This paper describes the development of a system for measuring surface coordinates (commonly known as ''shape measurements'') which is able to give the temporal evolution of the position of the tire sidewall in transient conditions (such as during braking, when there are potholes or when the road surface is uneven) which may or may not be reproducible. The system is based on the well-known technique of projecting and observing structured light using a digital camera with an optical axis which is slanted with respect to the axis of the projector. The transient nature of the phenomenon has led to the development of specific innovative solutions as regards image processing algorithms. This paper briefly describes the components which make up the measuring system and presents the results of the measurements carried out on the drum bench. It then analyses the performance of the measuring system and the sources of uncertainty which led to the development of the system for a specific dynamic application: impact with an obstacle (cleat test). The measuring system guaranteed a measurement uncertainty of 0.28 mm along the Z axis (the axial direction of the tire) with a measurement range of 250(X)x80(Y)x25(Z) mm{sup 3}, with the tire rolling at a speed of up to 30 km/h.

  3. System for measuring the coordinates of tire surfaces in transient conditions when rolling over obstacles: description of the system and performance analysis.

    PubMed

    Castellini, Paolo; Di Giuseppe, Andrea

    2008-06-01

    This paper describes the development of a system for measuring surface coordinates (commonly known as "shape measurements") which is able to give the temporal evolution of the position of the tire sidewall in transient conditions (such as during braking, when there are potholes or when the road surface is uneven) which may or may not be reproducible. The system is based on the well-known technique of projecting and observing structured light using a digital camera with an optical axis which is slanted with respect to the axis of the projector. The transient nature of the phenomenon has led to the development of specific innovative solutions as regards image processing algorithms. This paper briefly describes the components which make up the measuring system and presents the results of the measurements carried out on the drum bench. It then analyses the performance of the measuring system and the sources of uncertainty which led to the development of the system for a specific dynamic application: impact with an obstacle (cleat test). The measuring system guaranteed a measurement uncertainty of 0.28 mm along the Z axis (the axial direction of the tire) with a measurement range of 250(X) x 80(Y) x 25(Z) mm(3), with the tire rolling at a speed of up to 30 km/h. PMID:18601435

  4. System for measuring the coordinates of tire surfaces in transient conditions when rolling over obstacles: Description of the system and performance analysis

    NASA Astrophysics Data System (ADS)

    Castellini, Paolo; Di Giuseppe, Andrea

    2008-06-01

    This paper describes the development of a system for measuring surface coordinates (commonly known as "shape measurements") which is able to give the temporal evolution of the position of the tire sidewall in transient conditions (such as during braking, when there are potholes or when the road surface is uneven) which may or may not be reproducible. The system is based on the well-known technique of projecting and observing structured light using a digital camera with an optical axis which is slanted with respect to the axis of the projector. The transient nature of the phenomenon has led to the development of specific innovative solutions as regards image processing algorithms. This paper briefly describes the components which make up the measuring system and presents the results of the measurements carried out on the drum bench. It then analyses the performance of the measuring system and the sources of uncertainty which led to the development of the system for a specific dynamic application: impact with an obstacle (cleat test). The measuring system guaranteed a measurement uncertainty of 0.28mm along the Z axis (the axial direction of the tire) with a measurement range of 250(X)×80(Y)×25(Z)mm3, with the tire rolling at a speed of up to 30km/h.

  5. Coordinated Global Measurements of TLEs from the Space Shuttle and Ground Stations during MEIDEX

    NASA Astrophysics Data System (ADS)

    Yair, Y.; Price, C.; Levin, Z.; Israelevitch, P.; Devir, A.; Ziv, B.; Jospeh, J.; Mekler, Y.

    2001-12-01

    in the crew cabin. Simultaneously with the optical observations from space, dedicated ground measurements will be conducted on a global scale. Two field sites in the Negev Desert in Israel will be used to collect electromagnetic data in the ELF and VLF frequency range. Additional ground stations in Germany, Hungary, USA, Antarctica, Chile, South Africa, Australia, Taiwan and Japan will also record Schumann Resonance and VLF signals. The coordinated measurements from various locations on Earth and from space will enable us to triangulate the location, and determine the polarity and charge moment of the parent lightning of the optically observed TLEs. The success of the campaign will further clarify the global picture of TLE occurrence.

  6. Modelling and calibration technique of laser triangulation sensors for integration in robot arms and articulated arm coordinate measuring machines.

    PubMed

    Santolaria, Jorge; Guillomía, David; Cajal, Carlos; Albajez, José A; Aguilar, Juan J

    2009-01-01

    A technique for intrinsic and extrinsic calibration of a laser triangulation sensor (LTS) integrated in an articulated arm coordinate measuring machine (AACMM) is presented in this paper. After applying a novel approach to the AACMM kinematic parameter identification problem, by means of a single calibration gauge object, a one-step calibration method to obtain both intrinsic-laser plane, CCD sensor and camera geometry-and extrinsic parameters related to the AACMM main frame has been developed. This allows the integration of LTS and AACMM mathematical models without the need of additional optimization methods after the prior sensor calibration, usually done in a coordinate measuring machine (CMM) before the assembly of the sensor in the arm. The experimental tests results for accuracy and repeatability show the suitable performance of this technique, resulting in a reliable, quick and friendly calibration method for the AACMM final user. The presented method is also valid for sensor integration in robot arms and CMMs. PMID:22400001

  7. Using Mean Absolute Relative Phase, Deviation Phase and Point-Estimation Relative Phase to Measure Postural Coordination in a Serial Reaching Task

    PubMed Central

    Galgon, Anne K.; Shewokis, Patricia A.

    2016-01-01

    The objectives of this communication are to present the methods used to calculate mean absolute relative phase (MARP), deviation phase (DP) and point estimate relative phase (PRP) and compare their utility in measuring postural coordination during the performance of a serial reaching task. MARP and DP are derived from continuous relative phase time series representing the relationship between two body segments or joints during movements. MARP is a single measure used to quantify the coordination pattern and DP measures the stability of the coordination pattern. PRP also quantifies coordination patterns by measuring the relationship between the timing of maximal or minimal angular displacements of two segments within cycles of movement. Seven young adults practiced a bilateral serial reaching task 300 times over 3 days. Relative phase measures were used to evaluate inter-joint relationships for shoulder-hip (proximal) and hip-ankle (distal) postural coordination at early and late learning. MARP, PRP and DP distinguished between proximal and distal postural coordination. There was no effect of practice on any of the relative phase measures for the group, but individual differences were seen over practice. Combined, MARP and DP estimated stability of in-phase and anti-phase postural coordination patterns, however additional qualitative movement analyses may be needed to interpret findings in a serial task. We discuss the strengths and limitations of using MARP and DP and compare MARP and DP to PRP measures in assessing coordination patterns in the context of various types of skillful tasks. Key points MARP, DP and PRP measures coordination between segments or joint angles Advantages and disadvantages of each measure should be considered in relationship to the performance task MARP and DP may capture coordination patterns and stability of the patterns during discrete tasks or phases of movements within a task PRP and SD or PRP may capture coordination patterns and

  8. Application of a dimensional artifact to verify permanent-control programs of computer controlled coordinate measuring machines

    SciTech Connect

    Schweitzer, T.F.; Deitesfeld, C.A.

    1987-05-03

    The introduction of computer controlled coordinate measuring machines (CMM) created a concern for the Dimensional Metrology Laboratory at the Rocky Flats Plant, Golden, Colorado. The permanent-control program software of these machines required verification. Until the software was verified, it had to be assumed that the convergence of the modeling algorithms established by the manufacturer were acceptable. This report documents research for developing a method to verify the permanent-control programs of computer controlled CMMs.

  9. A program for performing exact quantum dynamics calculations using cylindrical polar coordinates: A nanotube application

    NASA Astrophysics Data System (ADS)

    Skouteris, Dimitris; Gervasi, Osvaldo; Laganà, Antonio

    2009-03-01

    A program that uses the time-dependent wavepacket method to study the motion of structureless particles in a force field of quasi-cylindrical symmetry is presented here. The program utilises cylindrical polar coordinates to express the wavepacket, which is subsequently propagated using a Chebyshev expansion of the Schrödinger propagator. Time-dependent exit flux as well as energy-dependent S matrix elements can be obtained for all states of the particle (describing its angular momentum component along the nanotube axis and the excitation of the radial degree of freedom in the cylinder). The program has been used to study the motion of an H atom across a carbon nanotube. Program summaryProgram title: CYLWAVE Catalogue identifier: AECL_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECL_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 3673 No. of bytes in distributed program, including test data, etc.: 35 237 Distribution format: tar.gz Programming language: Fortran 77 Computer: RISC workstations Operating system: UNIX RAM: 120 MBytes Classification: 16.7, 16.10 External routines: SUNSOFT performance library (not essential) TFFT2D.F (Temperton Fast Fourier Transform), BESSJ.F (from Numerical Recipes, for the calculation of Bessel functions) (included in the distribution file). Nature of problem: Time evolution of the state of a structureless particle in a quasicylindrical potential. Solution method: Time dependent wavepacket propagation. Running time: 50000 secs. The test run supplied with the distribution takes about 10 minutes to complete.

  10. GUI for Coordinate Measurement of an Image for the Estimation of Geometric Distortion of an Opto-electronic Display System

    NASA Astrophysics Data System (ADS)

    Saini, Surender Singh; Sardana, Harish Kumar; Pattnaik, Shyam Sundar

    2016-07-01

    Conventional image editing software in combination with other techniques are not only difficult to apply to an image but also permits a user to perform some basic functions one at a time. However, image processing algorithms and photogrammetric systems are developed in the recent past for real-time pattern recognition applications. A graphical user interface (GUI) is developed which can perform multiple functions simultaneously for the analysis and estimation of geometric distortion in an image with reference to the corresponding distorted image. The GUI measure, record, and visualize the performance metric of X/Y coordinates of one image over the other. The various keys and icons provided in the utility extracts the coordinates of distortion free reference image and the image with geometric distortion. The error between these two corresponding points gives the measure of distortion and also used to evaluate the correction parameters for image distortion. As the GUI interface minimizes human interference in the process of geometric correction, its execution just requires use of icons and keys provided in the utility; this technique gives swift and accurate results as compared to other conventional methods for the measurement of the X/Y coordinates of an image.

  11. Design and Mechanical Evaluation of a Capacitive Sensor-Based Indexed Platform for Verification of Portable Coordinate Measuring Instruments

    PubMed Central

    Avila, Agustín Brau; Mazo, Jorge Santolaria; Martín, Juan José Aguilar

    2014-01-01

    During the last years, the use of Portable Coordinate Measuring Machines (PCMMs) in industry has increased considerably, mostly due to their flexibility for accomplishing in-line measuring tasks as well as their reduced costs and operational advantages as compared to traditional coordinate measuring machines (CMMs). However, their operation has a significant drawback derived from the techniques applied in the verification and optimization procedures of their kinematic parameters. These techniques are based on the capture of data with the measuring instrument from a calibrated gauge object, fixed successively in various positions so that most of the instrument measuring volume is covered, which results in time-consuming, tedious and expensive verification procedures. In this work the mechanical design of an indexed metrology platform (IMP) is presented. The aim of the IMP is to increase the final accuracy and to radically simplify the calibration, identification and verification of geometrical parameter procedures of PCMMs. The IMP allows us to fix the calibrated gauge object and move the measuring instrument in such a way that it is possible to cover most of the instrument working volume, reducing the time and operator fatigue to carry out these types of procedures. PMID:24451458

  12. Design and mechanical evaluation of a capacitive sensor-based indexed platform for verification of portable coordinate measuring instruments.

    PubMed

    Avila, Agustín Brau; Mazo, Jorge Santolaria; Martín, Juan José Aguilar

    2014-01-01

    During the last years, the use of Portable Coordinate Measuring Machines (PCMMs) in industry has increased considerably, mostly due to their flexibility for accomplishing in-line measuring tasks as well as their reduced costs and operational advantages as compared to traditional coordinate measuring machines (CMMs). However, their operation has a significant drawback derived from the techniques applied in the verification and optimization procedures of their kinematic parameters. These techniques are based on the capture of data with the measuring instrument from a calibrated gauge object, fixed successively in various positions so that most of the instrument measuring volume is covered, which results in time-consuming, tedious and expensive verification procedures. In this work the mechanical design of an indexed metrology platform (IMP) is presented. The aim of the IMP is to increase the final accuracy and to radically simplify the calibration, identification and verification of geometrical parameter procedures of PCMMs. The IMP allows us to fix the calibrated gauge object and move the measuring instrument in such a way that it is possible to cover most of the instrument working volume, reducing the time and operator fatigue to carry out these types of procedures. PMID:24451458

  13. Lectures on Dynamical Models for Quantum Measurements

    NASA Astrophysics Data System (ADS)

    Nieuwenhuizen, Theo M.; Perarnau-Llobet, Martí Balian, Roger

    2015-10-01

    In textbooks, ideal quantum measurements are described in terms of the tested system only by the collapse postulate and Born's rule. This level of description offers a rather flexible position for the interpretation of quantum mechanics. Here we analyse an ideal measurement as a process of interaction between the tested system S and an apparatus A, so as to derive the properties postulated in textbooks. We thus consider within standard quantum mechanics the measurement of a quantum spin component ŝz by an apparatus A, being a magnet coupled to a bath. We first consider the evolution of the density operator of S+A describing a large set of runs of the measurement process. The approach describes the disappearance of the off-diagonal terms ("truncation") of the density matrix as a physical effect due to A, while the registration of the outcome has classical features due to the large size of the pointer variable, the magnetisation. A quantum ambiguity implies that the density matrix at the final time can be decomposed on many bases, not only the one of the measurement. This quantum oddity prevents to connect individual outcomes to measurements, a difficulty known as the "measurement problem". It is shown that it is circumvented by the apparatus as well, since the evolution in a small time interval erases all decompositions, except the one on the measurement basis. Once one can derive the outcome of individual events from quantum theory, the so-called "collapse of the wave function" or the "reduction of the state" appears as the result of a selection of runs among the original large set. Hence nothing more than standard quantum mechanics is needed to explain features of measurements. The employed statistical formulation is advocated for the teaching of quantum theory.

  14. Van Allen Probe measurements of the electric drift E × B/B2 at Arecibo's L = 1.4 field line coordinate

    NASA Astrophysics Data System (ADS)

    Lejosne, Solène; Mozer, F. S.

    2016-07-01

    We have used electric and magnetic measurements by Van Allen Probe B from 2013 to 2014 to examine the equatorial electric drift E × B/B2 at one field line coordinate set to Arecibo's incoherent scatter radar location (L = 1.43). We report on departures from the traditional picture of corotational motion with the Earth in two ways: (1) the rotational angular speed is found to be 10% smaller than the rotational angular speed of the Earth, in agreement with previous works on plasmaspheric notches, and (2) the equatorial electric drift displays a dependence in magnetic local time, with a pattern consistent with the mapping of the Arecibo ionosphere dynamo electric fields along equipotential magnetic field lines. The electric fields due to the ionosphere dynamo are therefore expected to play a significant role when discussing, for instance, the structure and dynamics of the plasmasphere or the transport of trapped particles in the inner belt.

  15. Huntingtin coordinates the dynein-mediated dynamic positioning of endosomes and lysosomes

    PubMed Central

    Caviston, Juliane P.; Zajac, Allison L.; Tokito, Mariko; Holzbaur, Erika L.F.

    2011-01-01

    Huntingtin (Htt) is a membrane-associated scaffolding protein that interacts with microtubule motors as well as actin-associated adaptor molecules. We examined a role for Htt in the dynein-mediated intracellular trafficking of endosomes and lysosomes. In HeLa cells depleted of either Htt or dynein, early, recycling, and late endosomes (LE)/lysosomes all become dispersed. Despite altered organelle localization, kinetic assays indicate only minor defects in intracellular trafficking. Expression of full-length Htt is required to restore organelle localization in Htt-depleted cells, supporting a role for Htt as a scaffold that promotes functional interactions along its length. In dynein-depleted cells, LE/lysosomes accumulate in tight patches near the cortex, apparently enmeshed by cortactin-positive actin filaments; Latrunculin B-treatment disperses these patches. Peripheral LE/lysosomes in dynein-depleted cells no longer colocalize with microtubules. Htt may be required for this off-loading, as the loss of microtubule association is not seen in Htt-depleted cells or in cells depleted of both dynein and Htt. Inhibition of kinesin-1 relocalizes peripheral LE/lysosomes induced by Htt depletion but not by dynein depletion, consistent with their detachment from microtubules upon dynein knockdown. Together, these data support a model of Htt as a facilitator of dynein-mediated trafficking that may regulate the cytoskeletal association of dynamic organelles. PMID:21169558

  16. Emergence of rich-club topology and coordinated dynamics in development of hippocampal functional networks in vitro.

    PubMed

    Schroeter, Manuel S; Charlesworth, Paul; Kitzbichler, Manfred G; Paulsen, Ole; Bullmore, Edward T

    2015-04-01

    Recent studies demonstrated that the anatomical network of the human brain shows a "rich-club" organization. This complex topological feature implies that highly connected regions, hubs of the large-scale brain network, are more densely interconnected with each other than expected by chance. Rich-club nodes were traversed by a majority of short paths between peripheral regions, underlining their potential importance for efficient global exchange of information between functionally specialized areas of the brain. Network hubs have also been described at the microscale of brain connectivity (so-called "hub neurons"). Their role in shaping synchronous dynamics and forming microcircuit wiring during development, however, is not yet fully understood. The present study aimed to investigate the role of hubs during network development, using multi-electrode arrays and functional connectivity analysis during spontaneous multi-unit activity (MUA) of dissociated primary mouse hippocampal neurons. Over the first 4 weeks in vitro, functional connectivity significantly increased in strength, density, and size, with mature networks demonstrating a robust modular and small-world topology. As expected by a "rich-get-richer" growth rule of network evolution, MUA graphs were found to form rich-clubs at an early stage in development (14 DIV). Later on, rich-club nodes were a consistent topological feature of MUA graphs, demonstrating high nodal strength, efficiency, and centrality. Rich-club nodes were also found to be crucial for MUA dynamics. They often served as broker of spontaneous activity flow, confirming that hub nodes and rich-clubs may play an important role in coordinating functional dynamics at the microcircuit level. PMID:25855164

  17. Emergence of Rich-Club Topology and Coordinated Dynamics in Development of Hippocampal Functional Networks In Vitro

    PubMed Central

    Charlesworth, Paul; Kitzbichler, Manfred G.; Paulsen, Ole

    2015-01-01

    Recent studies demonstrated that the anatomical network of the human brain shows a “rich-club” organization. This complex topological feature implies that highly connected regions, hubs of the large-scale brain network, are more densely interconnected with each other than expected by chance. Rich-club nodes were traversed by a majority of short paths between peripheral regions, underlining their potential importance for efficient global exchange of information between functionally specialized areas of the brain. Network hubs have also been described at the microscale of brain connectivity (so-called “hub neurons”). Their role in shaping synchronous dynamics and forming microcircuit wiring during development, however, is not yet fully understood. The present study aimed to investigate the role of hubs during network development, using multi-electrode arrays and functional connectivity analysis during spontaneous multi-unit activity (MUA) of dissociated primary mouse hippocampal neurons. Over the first 4 weeks in vitro, functional connectivity significantly increased in strength, density, and size, with mature networks demonstrating a robust modular and small-world topology. As expected by a “rich-get-richer” growth rule of network evolution, MUA graphs were found to form rich-clubs at an early stage in development (14 DIV). Later on, rich-club nodes were a consistent topological feature of MUA graphs, demonstrating high nodal strength, efficiency, and centrality. Rich-club nodes were also found to be crucial for MUA dynamics. They often served as broker of spontaneous activity flow, confirming that hub nodes and rich-clubs may play an important role in coordinating functional dynamics at the microcircuit level. PMID:25855164

  18. Quantum chemical and molecular dynamics study of the coordination of Th(IV) in aqueous solvent.

    PubMed

    Réal, Florent; Trumm, Michael; Vallet, Valérie; Schimmelpfennig, Bernd; Masella, Michel; Flament, Jean-Pierre

    2010-12-01

    In this work, we investigate the solvation of tetravalent thorium Th(IV) in aqueous solution using classical molecular dynamics simulations at the 10 ns scale and based on polarizable force-field approaches, which treat explicitly the covalent character of the metal-water interaction (and its inherent cooperative character). We have carried out a thorough analysis of the accuracy of the ab initio data that we used to adjust the force-field parameters. In particular, we show that large atomic basis sets combined with wave function-based methods (such as the MP2 level) have to be preferred to density functional theory when investigating Th(IV)/water aggregates in gas phase. The information extracted from trajectories in solution shows a well-structured Th(IV) first hydration shell formed of 8.25 ± 0.2 water molecules and located at about 2.45 ± 0.02 Å and a second shell of 17.5 ± 0.5 water molecules at about 4.75 Å. Concerning the first hydration sphere, our results correspond to the lower bounds of experimental estimates (which range from 8 to 12.7); however, they are in very good agreement with the average of existing experimental data, 2.45 ± 0.02 Å. All our results demonstrate the predictable character of the proposed approach, as well as the need of accounting explicitly for the cooperative character of charge-transfer phenomena affecting the Th(IV)/water interaction to build up reliable and accurate force-field approaches devoted to such studies. PMID:21070066

  19. Conductance measurement circuit with wide dynamic range

    NASA Technical Reports Server (NTRS)

    Mount, Bruce E. (Inventor); Von Esch, Myron (Inventor)

    1994-01-01

    A conductance measurement circuit to measure conductance of a solution under test with an output voltage proportional to conductance over a 5-decade range, i.e., 0.01 uS to 1000 uS or from 0.1 uS to 10,000 uS. An increase in conductance indicates growth, or multiplication, of the bacteria in the test solution. Two circuits are used each for an alternate half-cycle time periods of an alternate squarewave in order to cause alternate and opposite currents to be applied to the test solution. The output of one of the two circuits may be scaled for a different range optimum switching frequency dependent upon the solution conductance and to enable uninterrupted measurement over the complete 5-decade range. This circuitry provides two overlapping ranges of conductance which can be read simultaneously without discontinuity thereby eliminating range switching within the basic circuitry. A VCO is used to automatically change the operating frequency according to the particular value of the conductance being measured, and comparators indicate which range is valid and also facilitate computer-controlled data acquisition. A multiplexer may be used to monitor any number of solutions under test continuously.

  20. Introducing Variable-Step Topography (VST) coordinates within dynamically constrained Nonhydrostatic Modeling System (NMS). Part 1: VST formulation within NMS host model framework

    NASA Astrophysics Data System (ADS)

    Tripoli, Gregory J.; Smith, Eric A.

    2014-06-01

    A Variable-Step Topography (VST) surface coordinate system is introduced into a dynamically constrained, scalable, nonhydrostatic atmospheric model for reliable simulations of flows over both smooth and steep terrain without sacrificing dynamical integrity over either type of surface. Backgrounds of both terrain-following and step coordinate model developments are presented before justifying the turn to a VST approach within an appropriately configured host model. In this first part of a two-part sequence of papers, the full formulation of the VST model, prefaced by a description of the framework of its apposite host, i.e., a re-tooled Nonhydrostatic Modeling System (NMS), are presented. [The second part assesses the performance and benefits of the new VST coordinate system in conjunction with seven orthodox obstacle flow problems.] The NMS is a 3-dimensional, nonhydrostatic cloud-mesoscale model, designed for integrations from plume-cloud scales out to regional-global scales. The derivative properties of VST in conjunction with the NMS's newly designed dynamically constrained core are capable of accurately capturing the deformations of flows by any type of terrain variability. Numerical differencing schemes needed to satisfy critical integral constraints, while also effectively enabling the VST lower boundary, are described. The host model constraints include mass, momentum, energy, vorticity and enstrophy conservation. A quasi-compressible closure cast on multiple-nest rotated spherical grids is the underlying framework used to study the advantages of the VST coordinate system. The principle objective behind the VST formulation is to combine the advantages of both terrain-following and step coordinate systems without suffering either of their disadvantages, while at the same time creating a vertical surface coordinate setting suitable for a scalable, nonhydrostatic model, safeguarded with physically realistic dynamical constraints.

  1. HIGH DYNAMIC-RANGE HIGH SPEED LINAC CURRENT MEASUREMENTS

    SciTech Connect

    Deibele, Craig Edmond; Curry, Douglas E; Dickson, Richard W

    2012-01-01

    It is desired to measure the linac current of a charged particle beam with a consistent accuracy over a dynamic range of over 120 dB. Conventional current transformers suffer from droop, can be susceptible to electromagnetic interference (EMI), and can be bandwidth limited. A novel detector and electronics were designed to maximize dynamic range of about 120 dB and measure rise-times on the order of 10 nanoseconds.

  2. Laser application in measuring the dynamic deformation of gear teeth

    NASA Astrophysics Data System (ADS)

    Gao, Qi; Wu, Zhao-Tong; Li, Jianfeng; Tian, Zhiren

    1996-10-01

    The paper shows how the laser measurement method may be applied in mechanical engineering. Double-exposure speckle photography is used to measure the dynamic deformation of spur gear tooth. A series of experiments of gears with different speed, load and accuracy have been done and double-exposure speckle patterns at different meshing positions have been shot. The dynamic information of spur gear tooth during the whole meshing procedure is obtained by means of automatic image processing.

  3. Setting the Stage: Measure Selection, Coordination, and Data Collection for a National Self-Management Initiative

    PubMed Central

    Kulinski, Kristie P.; Boutaugh, Michele; Smith, Matthew Lee; Ory, Marcia G.; Lorig, Kate

    2015-01-01

    This paper describes the history and rationale behind the development of a centralized data collection system for the national rollout of the Chronic Disease Self-Management Program (CDSMP) through the American Recovery and Reinvestment Act of 2009 Communities Putting Prevention to Work: CDSMP initiative. In addition to justifying the need for solutions to the burgeoning burden of chronic disease in the United States, this paper provides details about CDSMP and related self-management education programs, including their structure, facilitator training, and effectiveness. These topics set the stage for the processes and procedures to create and manage the database for use at the national, state, and local levels. Furthermore, this paper describes the processes related to selecting variables, coordinating data collection, and utilizing data to inform research and policy. PMID:25964919

  4. Recent THEMIS and Coordinated GBO Measurements of Substorm Expansion Onset: Do We Finally Have an Answer?

    NASA Technical Reports Server (NTRS)

    Kepko, L.

    2011-01-01

    For nearly 30 years an often-times heated debate has engaged the substorm community: Do substorms begin with the formation of a new reconnection site in the midtail plasma sheet (the Near-Earth Neutral Line model) or do they begin near the transition region between stretched tail and dipolar field lines (the Current Disruption model). The THEMIS mission, with a coordinated suite of five in-situ spacecraft and ground observatories, has greatly extended our understanding of how substorms initiate and evolve. But have the new data resolved the fundamental question? In this talk I review the last few year's of sub storm research, with an emphasis of how the THEMIS data have revolutionized our understanding.

  5. Recent Themis and Coordinated GBO Measurements of Substorm Expansion Onset: Do We Finally Have an Answer?

    NASA Technical Reports Server (NTRS)

    Kepko, Larry

    2011-01-01

    For nearly 30 years an often-times heated debate has engaged the substorm community: Do substorms begin with the formation of a new reconnection site in the midtail plasmasheet (the Near-Earth Neutral Line model) or do they begin near the transition region between stretched tail and dipolar field lines (the Current Disruption model). The THEMIS mission, with a coordinated suite of five in-situ spacecraft and ground observatories. has greatly extended our understanding of how substorms initiate and evolve. But have the new data resolved the fundamental question? In this talk I review the last few year's of substorm research, with an emphasis of how the THEMIS data have revolutionized our understanding.

  6. The New Pelagic Operational Observatory of the Catalan Sea (OOCS) for the Multisensor Coordinated Measurement of Atmospheric and Oceanographic Conditions

    PubMed Central

    Bahamon, Nixon; Aguzzi, Jacopo; Bernardello, Raffaele; Ahumada-Sempoal, Miguel-Angel; Puigdefabregas, Joan; Cateura, Jordi; Muñoz, Eduardo; Velásquez, Zoila; Cruzado, Antonio

    2011-01-01

    The new pelagic Operational Observatory of the Catalan Sea (OOCS) for the coordinated multisensor measurement of atmospheric and oceanographic conditions has been recently installed (2009) in the Catalan Sea (41°39′N, 2°54′E; Western Mediterranean) and continuously operated (with minor maintenance gaps) until today. This multiparametric platform is moored at 192 m depth, 9.3 km off Blanes harbour (Girona, Spain). It is composed of a buoy holding atmospheric sensors and a set of oceanographic sensors measuring the water conditions over the upper 100 m depth. The station is located close to the head of the Blanes submarine canyon where an important multispecies pelagic and demersal fishery gives the station ecological and economic relevance. The OOCS provides important records on atmospheric and oceanographic conditions, the latter through the measurement of hydrological and biogeochemical parameters, at depths with a time resolution never attained before for this area of the Mediterranean. Twenty four moored sensors and probes operating in a coordinated fashion provide important data on Essential Ocean Variables (EOVs; UNESCO) such as temperature, salinity, pressure, dissolved oxygen, chlorophyll fluorescence, and turbidity. In comparison with other pelagic observatories presently operating in other world areas, OOCS also measures photosynthetic available radiation (PAR) from above the sea surface and at different depths in the upper 50 m. Data are recorded each 30 min and transmitted in real-time to a ground station via GPRS. This time series is published and automatically updated at the frequency of data collection on the official OOCS website (http://www.ceab.csic.es/~oceans). Under development are embedded automated routines for the in situ data treatment and assimilation into numerical models, in order to provide a reliable local marine processing forecast. In this work, our goal is to detail the OOCS multisensor architecture in relation to the

  7. The new pelagic Operational Observatory of the Catalan Sea (OOCS) for the multisensor coordinated measurement of atmospheric and oceanographic conditions.

    PubMed

    Bahamon, Nixon; Aguzzi, Jacopo; Bernardello, Raffaele; Ahumada-Sempoal, Miguel-Angel; Puigdefabregas, Joan; Cateura, Jordi; Muñoz, Eduardo; Velásquez, Zoila; Cruzado, Antonio

    2011-01-01

    The new pelagic Operational Observatory of the Catalan Sea (OOCS) for the coordinated multisensor measurement of atmospheric and oceanographic conditions has been recently installed (2009) in the Catalan Sea (41°39'N, 2°54'E; Western Mediterranean) and continuously operated (with minor maintenance gaps) until today. This multiparametric platform is moored at 192 m depth, 9.3 km off Blanes harbour (Girona, Spain). It is composed of a buoy holding atmospheric sensors and a set of oceanographic sensors measuring the water conditions over the upper 100 m depth. The station is located close to the head of the Blanes submarine canyon where an important multispecies pelagic and demersal fishery gives the station ecological and economic relevance. The OOCS provides important records on atmospheric and oceanographic conditions, the latter through the measurement of hydrological and biogeochemical parameters, at depths with a time resolution never attained before for this area of the Mediterranean. Twenty four moored sensors and probes operating in a coordinated fashion provide important data on Essential Ocean Variables (EOVs; UNESCO) such as temperature, salinity, pressure, dissolved oxygen, chlorophyll fluorescence, and turbidity. In comparison with other pelagic observatories presently operating in other world areas, OOCS also measures photosynthetic available radiation (PAR) from above the sea surface and at different depths in the upper 50 m. Data are recorded each 30 min and transmitted in real-time to a ground station via GPRS. This time series is published and automatically updated at the frequency of data collection on the official OOCS website (http://www.ceab.csic.es/~oceans). Under development are embedded automated routines for the in situ data treatment and assimilation into numerical models, in order to provide a reliable local marine processing forecast. In this work, our goal is to detail the OOCS multisensor architecture in relation to the coordinated

  8. Models for the prediction of polar coordinates of lunar reflectors in the dynamic Earth-Moon system

    NASA Astrophysics Data System (ADS)

    Teichert, B. D.

    Two models for the prediction of polar coordinates of reflectors installed on the Moon were investigated with respect to their usefulness for Lunar Laser Ranging (LLR). The first model is purely mechanical-analytical, and is based on the Brown Moon theory and on the Moon rotation and libration theory. The second method applies recursive filter algorithms using Kalman filtering. Data from laser ranging measurements were compared with data obtained with both models. Both models fulfil the required accuracy, and are more or less equivalent, with respect to the accuracy of the predictions of azimuth and elevation. However, for range, the Kalman filtering method is preferable. The FORTRAN computer programs for the Kalman filtering are enclosed.

  9. Incomplete fusion dynamics by spin distribution measurements

    SciTech Connect

    Singh, D.; Ali, R.; Ansari, M. Afzal; Singh, Pushpendra P.; Sharma, M. K.; Singh, B. P.; Babu, K. Surendra; Sinha, Rishi K.; Kumar, R.; Muralithar, S.; Singh, R. P.; Bhowmik, R. K.

    2010-02-15

    Spin distributions for various evaporation residues populated via complete and incomplete fusion of {sup 16}O with {sup 124}Sn at 6.3 MeV/nucleon have been measured, using charged particles (Z=1,2)-{gamma} coincidence technique. Experimentally measured spin distributions of the residues produced as incomplete fusion products associated with 'fast'{alpha}- and 2{alpha}-emission channels observed in the 'forward cone' are found to be distinctly different from those of the residues produced as complete fusion products. Moreover, 'fast'{alpha}-particles that arise from larger angular momentum in the entrance channel are populated at relatively higher driving input angular momentum than those produced through complete fusion. The incomplete fusion residues are populated in a limited, higher-angular-momentum range, in contrast to the complete fusion products, which are populated over a broad spin range.

  10. Making Scents: Dynamic Olfactometry for Threshold Measurement

    PubMed Central

    Schmidt, Roland

    2010-01-01

    Data on human odor thresholds show disparities huge enough to marginalize olfactory psychophysics and delegitimize importation of its data into other areas. Variation of orders of magnitude from study to study, much of it systematic, threatens meaningful comparisons with animal species, comparison between in vivo with in vitro studies, the search for molecular determinants of potency, and use of olfactory information for environmental or public health policy. On the premise that good experimental results will flow from use of good tools, this report describes a vapor delivery system and its peripherals that instantiate good tools. The vapor delivery device 8 (VDD8) provides flexibility in range of delivered concentrations, offers definable stability of delivery, accommodates solvent-free delivery below a part per trillion, gives a realistic interface with subjects, has accessible and replaceable components, and adapts to a variety of psychophysical methodologies. The device serves most often for measurement of absolute sensitivity, where its design encourages collection of thousands of judgments per day from subjects tested simultaneously. The results have shown humans to be more sensitive and less variable than has previous testing. The VDD8 can also serve for measurement of differential sensitivity, discrimination of quality, and perception of mixtures and masking. The exposition seeks to transmit general lessons while it proffers some specifics of design to reproduce features of the device in a new or existing system. The principles can apply to devices for animal testing. PMID:19965900

  11. The density matrix functional approach to electron correlation: dynamic and nondynamic correlation along the full dissociation coordinate.

    PubMed

    Mentel, Ł M; van Meer, R; Gritsenko, O V; Baerends, E J

    2014-06-01

    For chemistry an accurate description of bond weakening and breaking is vital. The great advantage of density matrix functionals, as opposed to density functionals, is their ability to describe such processes since they naturally cover both nondynamical and dynamical correlation. This is obvious in the Löwdin-Shull functional, the exact natural orbital functional for two-electron systems. We present in this paper extensions of this functional for the breaking of a single electron pair bond in N-electron molecules, using LiH, BeH(+), and Li2 molecules as prototypes. Attention is given to the proper formulation of the functional in terms of not just J and K integrals but also the two-electron L integrals (K integrals with a different distribution of the complex conjugation of the orbitals), which is crucial for the calculation of response functions. Accurate energy curves are obtained with extended Löwdin-Shull functionals along the complete dissociation coordinate using full CI calculations as benchmark. PMID:24907988

  12. The density matrix functional approach to electron correlation: Dynamic and nondynamic correlation along the full dissociation coordinate

    NASA Astrophysics Data System (ADS)

    Mentel, Ł. M.; van Meer, R.; Gritsenko, O. V.; Baerends, E. J.

    2014-06-01

    For chemistry an accurate description of bond weakening and breaking is vital. The great advantage of density matrix functionals, as opposed to density functionals, is their ability to describe such processes since they naturally cover both nondynamical and dynamical correlation. This is obvious in the Löwdin-Shull functional, the exact natural orbital functional for two-electron systems. We present in this paper extensions of this functional for the breaking of a single electron pair bond in N-electron molecules, using LiH, BeH+, and Li2 molecules as prototypes. Attention is given to the proper formulation of the functional in terms of not just J and K integrals but also the two-electron L integrals (K integrals with a different distribution of the complex conjugation of the orbitals), which is crucial for the calculation of response functions. Accurate energy curves are obtained with extended Löwdin-Shull functionals along the complete dissociation coordinate using full CI calculations as benchmark.

  13. The density matrix functional approach to electron correlation: Dynamic and nondynamic correlation along the full dissociation coordinate

    SciTech Connect

    Mentel, Ł. M.; Meer, R. van; Gritsenko, O. V.; Baerends, E. J.

    2014-06-07

    For chemistry an accurate description of bond weakening and breaking is vital. The great advantage of density matrix functionals, as opposed to density functionals, is their ability to describe such processes since they naturally cover both nondynamical and dynamical correlation. This is obvious in the Löwdin-Shull functional, the exact natural orbital functional for two-electron systems. We present in this paper extensions of this functional for the breaking of a single electron pair bond in N-electron molecules, using LiH, BeH{sup +}, and Li{sub 2} molecules as prototypes. Attention is given to the proper formulation of the functional in terms of not just J and K integrals but also the two-electron L integrals (K integrals with a different distribution of the complex conjugation of the orbitals), which is crucial for the calculation of response functions. Accurate energy curves are obtained with extended Löwdin-Shull functionals along the complete dissociation coordinate using full CI calculations as benchmark.

  14. Dynamic gas temperature measurement system, volume 1

    NASA Technical Reports Server (NTRS)

    Elmore, D. L.; Robinson, W. W.; Watkins, W. B.

    1983-01-01

    A gas temperature measurement system with compensated frequency response of 1 kHz and capability to operate in the exhaust of a gas turbine engine combustor was developed. A review of available technologies which could attain this objective was done. The most promising method was identified as a two wire thermocouple, with a compensation method based on the responses of the two different diameter thermocouples to the fluctuating gas temperature field. In a detailed design of the probe, transient conduction effects were identified as significant. A compensation scheme was derived to include the effects of gas convection and wire conduction. The two wire thermocouple concept was tested in a laboratory burner exhaust to temperatures of about 3000 F and in a gas turbine engine to combustor exhaust temperatures of about 2400 F. Uncompensated and compensated waveforms and compensation spectra are presented.

  15. Coordinated ground-based and geosynchronous satellite-based measurements of auroral pulsations

    SciTech Connect

    Suszcynsky, David M.; Borovsky, Joseph E.; Thomsen, Michelle F.; McComas, David J.; Belian, Richard D.

    1996-09-01

    We describe a technique that uses a ground-based all-sky video camera and geosynchronous satellite-based plasma and energetic particle detectors to study ionosphere-magnetosphere coupling as it relates to the aurora. The video camera system was deployed in Eagle, Alaska for a seven month period at the foot of the magnetic field line that threads geosynchronous satellite 1989-046. Since 1989-046 corotates with the earth, its footprint remains nearly fixed in the vicinity of Eagle, allowing for routine continuous monitoring of an auroral field line at its intersections with the ground and with geosynchronous orbit. As an example of the utility of this technique, we present coordinated ground-based and satellite based observations during periods of auroral pulsations and compare this data to the predictions of both the relaxation oscillator theory and flow cyclotron maser theory for the generation of pulsating aurorae. The observed plasma and energetic particle characteristics at geosynchronous orbit during pulsating aurorae displays are found to be in agreement with the predictions of both theories lending further support that a cyclotron resonance mechanism is responsible for auroral pulsations.

  16. Quantitative measures to reveal coordinated cytoskeleton-nucleus reorganization during in vitro invasion of cancer cells

    NASA Astrophysics Data System (ADS)

    Dvir, Liron; Nissim, Ronen; Alvarez-Elizondo, Martha B.; Weihs, Daphne

    2015-04-01

    Metastasis formation is a major cause of mortality in cancer patients and includes tumor cell relocation to distant organs. A metastatic cell invades through other cells and extracellular matrix by biochemical attachment and mechanical force application. Force is used to move on or through a 2- or 3-dimensional (3D) environment, respectively, or to penetrate a 2D substrate. We have previously shown that even when a gel substrate is impenetrable, metastatic breast cancer cells can still indent it by applying force. Cells typically apply force through the acto-myosin network, which is mechanically connected to the nucleus. We develop a 3D image-analysis to reveal relative locations of the cell elements, and show that as cells apply force to the gel, a coordinated process occurs that involves cytoskeletal remodeling and repositioning of the nucleus. Our approach shows that the actin and microtubules reorganize in the cell, bringing the actin to the leading edge of the cell. In parallel, the nucleus is transported behind the actin, likely by the cytoskeleton, into the indentation dimple formed in the gel. The nucleus volume below the gel surface correlates with indentation depth, when metastatic breast cancer cells indent gels deeply. However, the nucleus always remains above the gel in benign cells, even when small indentations are observed. Determining mechanical processes during metastatic cell invasion can reveal how cells disseminate in the body and can uncover targets for diagnosis and treatment.

  17. Symmetrically associated combination method for accuracy verification of Coordinate Measuring Machines

    NASA Astrophysics Data System (ADS)

    Wang, Hongtao; Chen, Xiaohuai; Fei, Yetai

    2008-10-01

    The paper is enlightened by the traditional combination verification method, provides a new detection way to CMM which is the combination of space one-dimension balls combination. It uses one-dimension balls instead of the standard ruler of the tradition combination verification method, adopts special researched detection equipment to CMM making one-dimension balls to three-dimension. The CMM processes the space random line with symmetry associating and comparing measurement method, and then uses the least-squares method to the measured data to obtain the measurement error of the space line, consequently realizes the measurement accuracy detection of the CMM.

  18. Towards Measurable Types for Dynamical Process Modeling Languages

    PubMed Central

    Mjolsness, Eric

    2011-01-01

    Process modeling languages such as “Dynamical Grammars” are highly expressive in the processes they model using stochastic and deterministic dynamical systems, and can be given formal semantics in terms of an operator algebra. However such process languages may be more limited in the types of objects whose dynamics is easily expressible. For many applications in biology, the dynamics of spatial objects in particular (including combinations of discrete and continuous spatial structures) should be formalizable at a high level of abstraction. We suggest that this may be achieved by formalizing such objects within a type system endowed with type constructors suitable for complex dynamical objects. To this end we review and illustrate the operator algebraic formulation of heterogeneous process modeling and semantics, extending it to encompass partial differential equations and intrinsic graph grammar dynamics. We show that in the operator approach to heterogeneous dynamics, types require integration measures. From this starting point, “measurable” object types can be enriched with generalized metrics under which approximation can be defined. The resulting measurable and “metricated” types can be built up systematically by type constructors such as vectors, products, and labelled graphs. We find conditions under which functions and quotients can be added as constructors of measurable and metricated types. PMID:21572536

  19. Essential Measures for Student Success: Implementing Cooperation, Collaboration, and Coordination between Schools and Parents

    ERIC Educational Resources Information Center

    Kirby, Edwena

    2012-01-01

    This book unveils "essential measures" that create a revitalized educational system of which educators and parents can use to promote student success. When these measures are applied properly, the benefits include, eradicating student fear, elevating student motivation, improving school attendance, and reducing student dropout rates. These…

  20. Simultaneous dynamic electrical and structural measurements of functional materials

    SciTech Connect

    Vecchini, C.; Stewart, M.; Muñiz-Piniella, A.; Wooldridge, J.; Thompson, P.; McMitchell, S. R. C.; Bouchenoire, L.; Brown, S.; Wermeille, D.; Lucas, C. A.; Lepadatu, S.; Bikondoa, O.; Hase, T. P. A.; Lesourd, M.; Dontsov, D.; Cain, M. G.

    2015-10-15

    A new materials characterization system developed at the XMaS beamline, located at the European Synchrotron Radiation Facility in France, is presented. We show that this new capability allows to measure the atomic structural evolution (crystallography) of piezoelectric materials whilst simultaneously measuring the overall strain characteristics and electrical response to dynamically (ac) applied external stimuli.

  1. Atom Interferometry Measurements of Static and Dynamic Polarizability

    NASA Astrophysics Data System (ADS)

    Trubko, Raisa; Holmgren, Will; Hromada, Ivan; Ronan, Joe; Cronin, Alex

    2011-10-01

    We report progress towards new measurements of static and dynamic polarizabilities for several atomic species. We use a nanograting Mach-Zehnder atom interferometer with an electric field gradient to observe atomic de Broglie wave phase shifts that are proportional to the electric polarizability. These measurements provide tests of atomic structure calculations that are needed to improve the precision of atomic clocks. We explain the progress and challenges of measuring the dynamic polarizability of potassium, the static polarizability of strontium and ytterbium, and several polarizability ratios (e.g. αNa/αLi) with one part per thousand accuracy.

  2. Altazimuth mount based dynamic calibration method for GNSS attitude measurement

    NASA Astrophysics Data System (ADS)

    Jiang, Nan; He, Tao; Sun, Shaohua; Gu, Qing

    2015-02-01

    As the key process to ensure the test accuracy and quality, the dynamic calibration of the GNSS attitude measuring instrument is often embarrassed by the lack of the rigid enough test platform and an accurate enough calibration reference. To solve the problems, a novel dynamic calibration method for GNSS attitude measurement based on altazimuth mount is put forward in this paper. The principle and implementation of this method are presented, and then the feasibility and usability of the method are analyzed in detail involving the applicability of the mount, calibrating precision, calibrating range, base line rigidity and the satellite signal involved factors. Furthermore, to verify and test the method, a confirmatory experiment is carried out with the survey ship GPS attitude measuring instrument, and the experimental results prove that it is a feasible way to the dynamic calibration for GNSS attitude measurement.

  3. High-speed scanning of critical structures in aviation using coordinate measurement machine and the laser ultrasonic.

    PubMed

    Swornowski, Pawel J

    2012-01-01

    Aviation is one of the know-how spheres containing a great deal of responsible sub-assemblies, in this case landing gear. The necessity for reducing production cycle times while achieving better quality compels metrologists to look for new and improved ways to perform inspection of critical structures. This article describes the ability to determine the shape deviation and location of defects in landing gear using coordinate measuring machines and laser ultrasonic with high-speed scanning. A nondestructive test is the basis for monitoring microcrack and corrosion propagation in the context of a damage-tolerant design approach. This article presents an overview of the basics and of the various metrological aspects of coordinate measurement and a nondestructive testing method in terms of high-speed scanning. The new test method (laser ultrasonic) promises to produce the necessary increase in inspection quality, but this is limited by the wide range of materials, geometries, and structure aeronautic parts used. A technique combining laser ultrasonic and F-SAFT (Fourier-Synthetic Aperture Focusing Technique) processing has been proposed for the detection of small defects buried in landing gear. The experimental results of landing gear inspection are also presented. PMID:22700384

  4. Hydrothermal alteration and diagenesis of terrestrial lacustrine pillow basalts: Coordination of hyperspectral imaging with laboratory measurements

    USGS Publications Warehouse

    Greenberger, Rebecca N; Mustard, John F; Cloutis, Edward A; Mann, Paul; Wilson, Janette H.; Flemming, Roberta L; Robertson, Kevin; Salvatore, Mark R; Edwards, Christopher

    2015-01-01

    The phases identified in the sample are albite, large iron oxides, and titanite throughout; calcite in vesicles; calcic clinopyroxene, aegirine, and Fe/Mg-bearing clay in the rind; and fine-grained hematite and pyroxenes in the interior. Using imaging spectroscopy, the chemistry and mineralogy results extend to the hand sample and larger outcrop. From all of the analyses, we suggest that the pillow basalts were altered initially after emplacement, either by heated lake water or magmatic fluids, at temperatures of at least 400-600°C, and the calcic clinopyroxenes and aegirine identified in the rind are a preserved record of that alteration. As the hydrothermal system cooled to slightly lower temperatures, clays formed in the rind, and, during this alteration, the sample oxidized to form hematite in the matrix of the interior and Fe3+ in the pyroxenes in the rind. During the waning stages of the hydrothermal system, calcite precipitated in vesicles within the rind. Later, diagenetic processes albitized the sample, with albite replacing plagioclase, lining vesicles, and accreting onto the exterior of the sample. This albitization or Na-metasomatism occurred when the lake within the Hartford Basin evaporated during a drier past climatic era, resulting in Na-rich brines. As Ca-rich plagioclase altered to albite, Ca was released into solution, eventually precipitating as calcite in previously-unfilled vesicles, dominantly in the interior of the pillow. Coordinated analyses of this sample permit identification of the alteration phases and help synthesize the aqueous history of pillow lavas of the Talcott formation. These results are also relevant to Mars, where volcanically-resurfaced open basin lakes have been found, and this Hartford Basin outcrop may be a valuable analog for any potential volcano-lacustrine interactions. The results can also help to inform the utility and optimization of potentially complementary, synergistic, and uniquely-suited techniques for

  5. Vertical dynamic deflection measurement in concrete beams with the Microsoft Kinect.

    PubMed

    Qi, Xiaojuan; Lichti, Derek; El-Badry, Mamdouh; Chow, Jacky; Ang, Kathleen

    2014-01-01

    The Microsoft Kinect is arguably the most popular RGB-D camera currently on the market, partially due to its low cost. It offers many advantages for the measurement of dynamic phenomena since it can directly measure three-dimensional coordinates of objects at video frame rate using a single sensor. This paper presents the results of an investigation into the development of a Microsoft Kinect-based system for measuring the deflection of reinforced concrete beams subjected to cyclic loads. New segmentation methods for object extraction from the Kinect's depth imagery and vertical displacement reconstruction algorithms have been developed and implemented to reconstruct the time-dependent displacement of concrete beams tested in laboratory conditions. The results demonstrate that the amplitude and frequency of the vertical displacements can be reconstructed with submillimetre and milliHz-level precision and accuracy, respectively. PMID:24556668

  6. Vertical Dynamic Deflection Measurement in Concrete Beams with the Microsoft Kinect

    PubMed Central

    Qi, Xiaojuan; Lichti, Derek; El-Badry, Mamdouh; Chow, Jacky; Ang, Kathleen

    2014-01-01

    The Microsoft Kinect is arguably the most popular RGB-D camera currently on the market, partially due to its low cost. It offers many advantages for the measurement of dynamic phenomena since it can directly measure three-dimensional coordinates of objects at video frame rate using a single sensor. This paper presents the results of an investigation into the development of a Microsoft Kinect-based system for measuring the deflection of reinforced concrete beams subjected to cyclic loads. New segmentation methods for object extraction from the Kinect's depth imagery and vertical displacement reconstruction algorithms have been developed and implemented to reconstruct the time-dependent displacement of concrete beams tested in laboratory conditions. The results demonstrate that the amplitude and frequency of the vertical displacements can be reconstructed with submillimetre and milliHz-level precision and accuracy, respectively. PMID:24556668

  7. Effects of Coordinate Rotation and Averaging Period on Energy Closure Characteristics of Eddy Covariance Measurements over Mountainous Terrain

    NASA Astrophysics Data System (ADS)

    Li, M.; Chen, Y.

    2009-12-01

    Coordinate rotation is typically applied to align measured turbulence data along the stream wise direction before calculating turbulent fluxes. A standard averaging period (30 min) is commonly used when estimating these fluxes. Different rotation approaches with various averaging periods can cause systemic bias and significant variations in flux estimations. Thus, measuring surface fluxes over a non-flat terrain requires that an appropriate rotation technique and optimal averaging period are applied. In this study, two coordinate rotation approaches (double and planar-fit rotations) and no-rotation, in associated with averaging periods of 15-240 min, were applied to compute heat and water vapor fluxes over a mountainous terrain using the eddy covariance method. Measurements were conducted in an experimental watershed, the Lien-Hua-Chih (LHC) watershed, located in the central Taiwan. This watershed has considerable meso-scale circulation and mountainous terrain. Vegetation type is a mixture of natural deciduous forest and shrubs; canopy height is about 17 m. A 22 m tall observation tower was built inside the canopy. The prevailing wind direction is NW during daytime and ES during the night time at the LHC site in both the dry and wet seasons. Turbulence data above the canopy were measured with an eddy covariance system comprising a 3-D sonic anemometer (Young 81000) and a krypton hygrometer (Campbell KH20). Raw data of 10 Hz were recorded simultaneously with a data logger (CR1000) and a CF card. Air temperature/humidity profiles were measured to calculate the heat/moisture storage inside the canopy layer. Air pressure data were used to correct the effect of air density fluctuations on surface fluxes. The effects of coordinate rotation approaches with various averaging periods on the average daily energy closure fraction are presented. The criteria of the best energy closure fraction and minimum uncertainty indicate that planar-fit rotation with an averaging period

  8. Measuring the Dynamic Parameters of MCF7 Cell Microtubules

    NASA Astrophysics Data System (ADS)

    Winton, Carly; Shojania Feizabadi, Mitra

    2013-03-01

    Microtubules are the key component of the cytoskeleton. They are intrinsically dynamic displaying dynamic instability in which they randomly switch between a phase of growing and shrinking, both in vitro and in vivo. This dynamic is specified by the following parameters: growing rate, shrinking rate, frequency of catastrophe, and frequency of rescue. In this work, we will present our primary results in which we measured the dynamic parameters of a single microtubule polymerized from MCF7 tubulin in vitro. The results are significant since the MCF7 microtubules are non-neural mammalian consisting of different beta tubulin isotypes in their structures as compared to neural mammalian microtubules, such as bovine brain. The unique dynamic parameters of individual MCF7 microtubules in vitro, which are reported for the first time, indicate that non-neural microtubules can be fundamentally different from neural microtubules.

  9. Phase unwrapping in the dynamic 3D measurement

    NASA Astrophysics Data System (ADS)

    Su, Xianyu; Zhang, Qican

    2010-04-01

    In the dynamic 3D shape measurement phase distribution has 3D character, in which phase changes along x and y directions in space and also along t direction in time. 3D phase unwrapping plays a very important role in the dynamic 3D shape measurement. In the dynamic 3D shape measurement methods based on the structured illumination, Fourier transformation profilometry (FTP) is particularly fit for dynamic 3D measurement, because of only one fringe pattern needed and full field analysis. In this paper some 3D phase unwrapping techniques for dynamic 3D shape measurement mainly in our Lab. are presented and reviewed. The basic methods and algorithm design are introduced. The basic methods include direct 3D phase unwrapping, 3D diamond phase unwrapping, 3D phase unwrapping based on reliability ordering, 3D phase unwrapping based on marked fringe tracing. The advantage of the phase unwrapping based on reliability ordering is that the path of phase unwrapping is always along the direction from the pixel with higher reliability parameter value to the pixel with low reliability parameter value. Therefore, in the worse case the error is limited, if there is any, to local minimum areas.

  10. Development of a transfer function method for dynamic stability measurement

    NASA Technical Reports Server (NTRS)

    Johnson, W.

    1977-01-01

    Flutter testing method based on transfer function measurements is developed. The error statistics of several dynamic stability measurement methods are reviewed. It is shown that the transfer function measurement controls the error level by averaging the data and correlating the input and output. The method also gives a direct estimate of the error in the response measurement. An algorithm is developed for obtaining the natural frequency and damping ratio of low damped modes of the system, using integrals of the transfer function in the vicinity of a resonant peak. Guidelines are given for selecting the parameters in the transfer function measurement. Finally, the dynamic stability measurement technique is applied to data from a wind tunnel test of a proprotor and wing model.

  11. Cumulative Measurement Errors for Dynamic Testing of Space Flight Hardware

    NASA Technical Reports Server (NTRS)

    Winnitoy, Susan

    2012-01-01

    Located at the NASA Johnson Space Center in Houston, TX, the Six-Degree-of-Freedom Dynamic Test System (SDTS) is a real-time, six degree-of-freedom, short range motion base simulator originally designed to simulate the relative dynamics of two bodies in space mating together (i.e., docking or berthing). The SDTS has the capability to test full scale docking and berthing systems utilizing a two body dynamic docking simulation for docking operations and a Space Station Remote Manipulator System (SSRMS) simulation for berthing operations. The SDTS can also be used for nonmating applications such as sensors and instruments evaluations requiring proximity or short range motion operations. The motion base is a hydraulic powered Stewart platform, capable of supporting a 3,500 lb payload with a positional accuracy of 0.03 inches. The SDTS is currently being used for the NASA Docking System testing and has been also used by other government agencies. The SDTS is also under consideration for use by commercial companies. Examples of tests include the verification of on-orbit robotic inspection systems, space vehicle assembly procedures and docking/berthing systems. The facility integrates a dynamic simulation of on-orbit spacecraft mating or de-mating using flight-like mechanical interface hardware. A force moment sensor is used for input during the contact phase, thus simulating the contact dynamics. While the verification of flight hardware presents unique challenges, one particular area of interest involves the use of external measurement systems to ensure accurate feedback of dynamic contact. The measurement systems for the test facility have two separate functions. The first is to take static measurements of facility and test hardware to determine both the static and moving frames used in the simulation and control system. The test hardware must be measured after each configuration change to determine both sets of reference frames. The second function is to take dynamic

  12. Coordinated Airborne, Spaceborne and Ground-based Measurements of Massive Thick Aerosol Layers during the Dry Season in Southern Africa

    NASA Technical Reports Server (NTRS)

    Schmid, B.; Redemann, J.; Russell, P. B.; Hobbs, P. V.; Hlavka, D. L.; McGill, M. J.; Holben, B. N.; Welton, E. J.; Campbell, J. R.; Torres, O.

    2003-01-01

    During the dry season airborne campaign of the Southern African Regional Science Initiative (SAFARI 2000), coordinated observations were made of massive thick aerosol layers. These layers were often dominated by aerosols from biomass burning. We report on airborne Sun photometer measurements of aerosol optical depth (lambda = 0.354- 1.557 microns), columnar water vapor, and vertical profiles of aerosol extinction and water vapor density that were obtained aboard the University of Washington's Convair-580 research aircraft. We compare these with ground-based AERONET Sun/sky radiometer results, with ground based lidar data (MPL-Net), and with measurements from a downward pointing lidar aboard the high-flying NASA ER-2 aircraft. Finally, we show comparisons between aerosol optical depths fiom the Sun photometer and those retrieved over land and over water using four spaceborne sensors (TOMS, MODIS, MISR, and ATSR-2).

  13. Coordinated Airborne, Spaceborne, and Ground-Based Measurements of Massive, Thick Aerosol Layers During the Dry Season in Southern Africa

    NASA Technical Reports Server (NTRS)

    Schmid, B.; Redemann, J.; Russell, P. B.; Hobbs, P. V.; Hlavka, D. L.; McGill, M. J.; Holben, B. N.; Welton, E. J.; Campbell, J.; Torres, O.; Hipskind, R. Stephen (Technical Monitor)

    2002-01-01

    During the dry-season airborne campaign of the Southern African Regional Science Initiative (SAFARI 2000), unique coordinated observations were made of massive, thick aerosol layers. These layers were often dominated by aerosols from biomass burning. We report on airborne Sunphotometer measurements of aerosol optical depth (lambda=354-1558 nm), columnar water vapor, and vertical profiles of aerosol extinction and water vapor density that were obtained aboard the University of Washington's Convair-580 research aircraft. We compare these with ground-based AERONET Sun/sky radiometer results, with ground based lidar data MPL-Net), and with measurements from a downward-pointing lidar aboard the high-flying NASA ER-2 aircraft. Finally, we show comparisons between aerosol optical depths from the Sunphotometer and those retrieved over land and over water using four spaceborne sensors (TOMS (Total Ozone Mapping Spectrometer), MODIS (Moderate Resolution Imaging Spectrometer), MISR (Multiangle Imaging Spectroradiometer) and ATSR-2 (Along Track Scanning Radiometer)).

  14. Dynamic Aperture Measurements at the Advanced Light Source

    SciTech Connect

    Decking, W.; Robin, D.

    1999-03-12

    A large dynamic aperture for a storage ring is of importance for long lifetimes and a high injection efficiency. Measurements of the dynamic aperture of the third generation synchrotron light source Advanced Light Source (ALS) using beam excitation with kicker magnets are presented. The experiments were done for various accelerator conditions, allowing us to investigate the influence of different working points, chromaticities, insertion devices, etc.. The results are compared both with tracking calculations and a simple model for the dynamic aperture yielding good agreements. This gives us confidence in the predictability of the nonlinear accelerator model. This is especially important for future ALS upgrades as well as new storage ring designs.

  15. Development of a probing system for a micro-coordinate measuring machine by utilizing shear-force detection

    NASA Astrophysics Data System (ADS)

    Ito, So; Kodama, Issei; Gao, Wei

    2014-06-01

    This paper introduces a newly developed probing system for a micro-coordinate measurement machine (micro-CMM) based on an interaction force generated by the water layer on the surface of the measuring object. In order to measure the dimensions of the micrometric structures, a probing system using a nanopipette ball stylus has been developed. A glass microsphere with diameter of 9 µm is used as a stylus tip of the probing system. The glass nanopipette, which is fabricated from a capillary glass tube by a thermal pulling process, is employed as a stylus shaft to improve the fixation strength of the stylus tip. The approach between the stylus tip and the surface of the measuring object can be detected by utilizing the method of shear-force detection. The stylus is oscillated in the lateral direction at its resonant frequency to detect an interaction force owing to the viscoelasticity of the meniscus layer existing on the surface of the measuring object. The oscillation amplitude is decreased by the shear-force applied to the stylus tip. In this study, the basic characteristics of the probing system including sensitivity, resolution and reproducibility are investigated. The experimental result of dimensional measurement of micrometer-scale structure is presented.

  16. Dual redundant arm system operational quality measures and their applications - Dynamic measures

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan; Kim, Sungbok

    1990-01-01

    Dual-arm dynamic operation quality measures are presented which quantify the efficiency and capability of generating Cartesian accelerations by two cooperative arms based on the analysis of dual-arm dynamic interactions. Dual-arm dynamic manipulability is defined as the efficiency of generating Cartesian accelerations under the dynamic and kinematic interactions between individual arms and an object under manipulation. The analysis of dual-arm dynamic interactions is based on the so-called Cartesian space agent model of an arm, which represents an individual arm as a force source acting upon a point mass with the effective Cartesian space arm dynamics and an environment or an object under manipulation. The Cartesian space agent model of an arm makes it possible to derive the dynamic and kinematic constraints involved in the transport, assembly and grasping modes of dual-arm cooperation. A task-oriented operational quality measure, (TOQd) is defined by evaluating dual-arm dynamic manipulability in terms of given task requirements. TOQd is used in dual-arm joint configuration optimization. Simulation results are shown. A complete set of forward dynamic equations for a dual-arm system is derived, and dual-arm dynamic operational quality measures for various modes of dual-arm cooperation allowing sliding contacts are established.

  17. Design of a data acquisition system of articulated arm coordinate measuring machines

    NASA Astrophysics Data System (ADS)

    Yang, Huiping; Gao, Guanbin; Wang, Wen

    2015-02-01

    A novel cylindrical capacitive sensor (CCS) with differential, symmetrical and integrated structure was proposed to measure multi-degree-of-freedom rotation errors of high precision spindle simultaneously and to reduce impacts of multiple-sensors installation errors on the measurement accuracy. The nonlinear relationship between the output capacitance of CCS and the radial gap was derived using the capacitance formula and was quantitatively analyzed. It was found through analysis that the thickness of curved electrode plates led to the existence of fringe effect. The influence of the fringe effect on the output capacitance was investigated through FEM simulation. It was found through analysis and simulation that the CCS could be optimized to improve the measurement accuracy.

  18. Coordinated analysis of airborne spectrophotometric measurements from the mid-day auroras

    NASA Technical Reports Server (NTRS)

    Sivjee, G. G.

    1974-01-01

    Measurements made in the midday auroras are analyzed and compared to measurements from the nighttime auroras. The auroral emission features in the UV spectrum, the N2(+)ING, the N22PG, and N2VK bands, are discussed. Spectral profiles of different bands are presented, and intensity distributions are obtained. Three mechanisms are suggested which can account for the marked differences between the intensity distributions of the N2(+)ING bands of the high altitude midday auroras and the low altitude nighttime auroras: (1) differences in vibrational, rotational, and transitional temperatures; (2) resonant scattering of solar radiation; and (3) excitation of slow ions.

  19. Dynamic Tire Pressure Sensor for Measuring Ground Vibration

    PubMed Central

    Wang, Qi; McDaniel, James Gregory; Wang, Ming L.

    2012-01-01

    This work presents a convenient and non-contact acoustic sensing approach for measuring ground vibration. This approach, which uses an instantaneous dynamic tire pressure sensor (DTPS), possesses the capability to replace the accelerometer or directional microphone currently being used for inspecting pavement conditions. By measuring dynamic pressure changes inside the tire, ground vibration can be amplified and isolated from environmental noise. In this work, verifications of the DTPS concept of sensing inside the tire have been carried out. In addition, comparisons between a DTPS, ground-mounted accelerometer, and directional microphone are made. A data analysis algorithm has been developed and optimized to reconstruct ground acceleration from DTPS data. Numerical and experimental studies of this DTPS reveal a strong potential for measuring ground vibration caused by a moving vehicle. A calibration of transfer function between dynamic tire pressure change and ground acceleration may be needed for different tire system or for more accurate application. PMID:23202206

  20. Dynamic tire pressure sensor for measuring ground vibration.

    PubMed

    Wang, Qi; McDaniel, James Gregory; Wang, Ming L

    2012-01-01

    This work presents a convenient and non-contact acoustic sensing approach for measuring ground vibration. This approach, which uses an instantaneous dynamic tire pressure sensor (DTPS), possesses the capability to replace the accelerometer or directional microphone currently being used for inspecting pavement conditions. By measuring dynamic pressure changes inside the tire, ground vibration can be amplified and isolated from environmental noise. In this work, verifications of the DTPS concept of sensing inside the tire have been carried out. In addition, comparisons between a DTPS, ground-mounted accelerometer, and directional microphone are made. A data analysis algorithm has been developed and optimized to reconstruct ground acceleration from DTPS data. Numerical and experimental studies of this DTPS reveal a strong potential for measuring ground vibration caused by a moving vehicle. A calibration of transfer function between dynamic tire pressure change and ground acceleration may be needed for different tire system or for more accurate application. PMID:23202206

  1. Dynamic subcriticality measurements using the CF neutron noise method: Videotape

    SciTech Connect

    Mihalczo, J.T.; Blakeman, E.D.; Ragan, G.E.; Johnson, E.B.

    1987-01-01

    The capability to measure the subcriticality for a multiplying system with k-effective values as low as 0.3 was demonstrated for measurement times of approximately 10 s; the measured k-effective values obtained do not depend on the speed with which the solution height is changed or on whether the tank is filling or draining. As in previous experiments, the low-frequency ratios of spectral densities are all that are needed to obtain the k-effective value. This method's effectiveness for systems where conditions are changing with time as demonstrated, probably exceeds the dynamic requirements for most nuclear fuel plant processing applications. The calculated k-effective values using the KENO code and Hansen-Roach cross-sections compare well with the experimental values. Before the dynamic capability of the method can be considered fully explored, additional dynamic experiments are required for other geometries and fuel concentrations.

  2. Dynamic fracture toughness evaluation by measurement of CTOD

    SciTech Connect

    Sharpe, W.N. Jr.; Douglas, A.S.; Shapiro, J.M.

    1988-02-01

    Quantification of the dynamic fracture toughness of structural materials is essential to a wide range of problems-from nuclear accidents to ordnance applications. However, the difficulties associated with accurate measurements of crack under dynamic loading are considerable. Thus there are no standardized procedures and few reliable results. A systematic study of the dynamic fracture toughness of SAE-01 tool steel, 4340 and HY100 steels, and a tungsten are described using the Interferometric Strain/Displacement Gage (ISDG) system which has very high frequency resolution. The ISDG system is used to measure the crack tip opening displacement (CTOD) 100 microns behind a fatigue crack tip in a three-point bend specimen. Static measurements on similar specimens serve to calibrate the method and ensure consistency with the accepted procedures for static fracture toughness testing. Finite element analyses are used to obtain full field information at the point of initiation and to assess the material characteristics which lead to changes in toughness with loading rate. The major advantage of the method is that information is obtained very close to the crack tip, so that stress wave loading effects are accounted for. Results show that 4340 steel, which is strain-rate insensitive, has no significant change in toughness with loading rate. Measurable toughness dependence on loading rate is found for HY-100 and tungsten, which are approximately 15 percent tougher under dynamic conditions. The SAE-01 tool steel shows a significant increase (50 percent) in fracture toughness for dynamic over static loading.

  3. Rayleigh Scattering Diagnostic for Dynamic Measurement of Velocity and Temperature

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.; Panda, J.

    2001-01-01

    A new technique for measuring dynamic gas velocity and temperature is described. The technique is based on molecular Rayleigh scattering of laser light, so no seeding of the flow is necessary. The Rayleigh scattered light is filtered with a fixed cavity, planar mirror Fabry-Perot interferometer. A minimum number of photodetectors were used in order to allow the high data acquisition rate needed for dynamic measurements. One photomultiplier tube (PMT) was used to measure the total Rayleigh scattering, which is proportional to the gas density. Two additional PMTs were used to detect light that passes through two apertures in a mask located in the interferometer fringe plane. An uncertainty analysis was used to select the optimum aperture parameters and to predict the measurement uncertainty due to photon shot-noise. Results of an experiment to measure the velocity of a subsonic free jet are presented.

  4. Color measurement in standard CIELAB coordinates using a 3CCD camera: correction for the influence of the light source

    NASA Astrophysics Data System (ADS)

    Corbalan-Fuertes, Montserrat; Millan, Maria S.; Yzuel, Maria J.

    2000-06-01

    We have analyzed the accuracy of the compensating performance of the white-balance mechanism of a 3CCD camera for the three common types of light--fluorescent (F), incandescent (I), and daylight (D). We study the behavior of the camera using the RGB and CIELAB coordinates for a wide set of color samples covering the visible spectrum. CIELAB coordinates are obtained from the tristimulus XYZ. Using linear methods, we obtain the XYZ values from the (RGB)CCD values acquired by a 3CCD camera. We propose two different approaches: the first is specific for each particular light source (F, I, and D); the second considers the equienergetic spectral light source as an approximation for white lighting. We measure the mean color difference in the CIELAB space under a change of illuminant and compare the results in order to evaluate the performance of the response of a 3CCD camera. The transformations that are specific for a given light source allow an improved response under change of illuminant in terms of color constancy.

  5. Gravimetric method for the dynamic measurement of urine flow.

    PubMed

    Steele, J E; Skarlatos, S; Brand, P H; Metting, P J; Britton, S L

    1993-10-01

    The rate of urine formation is a primary index of renal function, but no techniques are currently available to accurately measure low rates of urine flow on a continuous basis, such as are normally found in rats. We developed a gravimetric method for the dynamic measurement of urine flow in anesthetized rats. Catheters were inserted directly into the ureters close to the renal pelves, and a siphon was created to collect all of the urine formed as rapidly as it was produced. Urine flow was determined by measuring the weight of the urine using a direct-reading analytical balance interfaced to a computer. Basal urine flow was measured at 2-sec intervals for 30 to 60 min. The dynamic response of urine flow to a rapid decrease in arterial pressure produced by a bolus intravenous injection of acetylcholine (0.5 micrograms) was also measured. Intrinsic drift, evaporative losses, and the responsiveness of the system to several fixed pump flows in the low physiologic range were evaluated in vitro. The gravimetric method described was able to continuously measure basal urine flows that averaged 37.3 +/- 12.4 microliters/min. Error due to drift and evaporation was negligible, totaling less than 1% of the measured urine flow. Acetylcholine-induced declines in arterial pressure were followed within 8 sec by a decline in urine flow. These data demonstrate that this new gravimetric method provides a simple, inexpensive, dynamic measurement of urine flow in the microliter/min range. PMID:8372099

  6. An innovative method for coordinate measuring machine one-dimensional self-calibration with simplified experimental process

    NASA Astrophysics Data System (ADS)

    Fang, Cheng; Butler, David Lee

    2013-05-01

    In this paper, an innovative method for CMM (Coordinate Measuring Machine) self-calibration is proposed. In contrast to conventional CMM calibration that relies heavily on a high precision reference standard such as a laser interferometer, the proposed calibration method is based on a low-cost artefact which is fabricated with commercially available precision ball bearings. By optimizing the mathematical model and rearranging the data sampling positions, the experimental process and data analysis can be simplified. In mathematical expression, the samples can be minimized by eliminating the redundant equations among those configured by the experimental data array. The section lengths of the artefact are measured at arranged positions, with which an equation set can be configured to determine the measurement errors at the corresponding positions. With the proposed method, the equation set is short of one equation, which can be supplemented by either measuring the total length of the artefact with a higher-precision CMM or calibrating the single point error at the extreme position with a laser interferometer. In this paper, the latter is selected. With spline interpolation, the error compensation curve can be determined. To verify the proposed method, a simple calibration system was set up on a commercial CMM. Experimental results showed that with the error compensation curve uncertainty of the measurement can be reduced to 50%.

  7. Direct measurements of the coordination of lever arm swing and the catalytic cycle in myosin V

    PubMed Central

    Trivedi, Darshan V.; Muretta, Joseph M.; Swenson, Anja M.; Davis, Jonathon P.; Thomas, David D.; Yengo, Christopher M.

    2015-01-01

    Myosins use a conserved structural mechanism to convert the energy from ATP hydrolysis into a large swing of the force-generating lever arm. The precise timing of the lever arm movement with respect to the steps in the actomyosin ATPase cycle has not been determined. We have developed a FRET system in myosin V that uses three donor–acceptor pairs to examine the kinetics of lever arm swing during the recovery and power stroke phases of the ATPase cycle. During the recovery stroke the lever arm swing is tightly coupled to priming the active site for ATP hydrolysis. The lever arm swing during the power stroke occurs in two steps, a fast step that occurs before phosphate release and a slow step that occurs before ADP release. Time-resolved FRET demonstrates a 20-Å change in distance between the pre- and postpower stroke states and shows that the lever arm is more dynamic in the postpower stroke state. Our results suggest myosin binding to actin in the ADP.Pi complex triggers a rapid power stroke that gates the release of phosphate, whereas a second slower power stroke may be important for mediating strain sensitivity. PMID:26553992

  8. Coordinated rocket and satellite measurements of an auroral event. II - The rocket observations and analysis

    NASA Technical Reports Server (NTRS)

    Sharp, W. E.; Rees, M. H.; Stewart, A. I.

    1979-01-01

    A rocket-borne payload launched into an aurora and a simultaneous overpass of the Atmosphere Explorer C satellite yielded measurements of auroral optical emission rates, thermal ion and electron densities, and low-energy electron fluxes. Model calculations of the thermospheric manifestation of the aurora were performed through use of rocket-determined auroral ionization rates and satellite-determined neutral gas densities. Measured oxygen densities provided a means of assessing the quenching rate of an excited state of N2. Energy transfer from this excited state appears to be the major source of 5577-A emission. Optical emission at 6300 A cannot be explained either by electron impact on atomic oxygen or by dissociative recombination of O2(+).

  9. Effect of refraction parallax on the accuracy of measuring the angular coordinates of artificial satellites

    NASA Astrophysics Data System (ADS)

    Vygon, V. G.; Deryugina, A. I.

    1994-03-01

    This paper analyzes the effect of optical refraction in the earth's atmosphere on the accuracy of astronometric measurements, and presents the results of calculations that were used to investigate the accuracy with which the orbits of artificial satellites are reconstructed from the data of goniometric observations. It is shown that, in a number of cases, neglecting the effect of refraction parallax results in fundamental errors in the character of the reconstructed trajectories.

  10. Dynamics and constituent measurements with the Waves Michelson Interferometer

    NASA Astrophysics Data System (ADS)

    Ward, W. E.; Wang, D. Y.; Kowalski, M.; Gault, W. A.; Bell, A.

    The Waves Michelson Interferometer WaMI is an imaging Michelson interferometer designed to provide altitude profiles of wind temperature ozone atomic oxygen and density from the stratopause to the lower thermosphere This is accomplished through simultaneous measurements of the Doppler shifts line widths and irradiance of emission lines in airglow emissions O2 IR atmospheric band OH and O 1S These measurements are crucial to an understanding the behaviour of the upper stratosphere and mesosphere and its role in the middle atmosphere Observations in this region are complicated by observational issues and subtleties in the dynamical forcings Amplitudes of gravity waves and tides are substantial and as a result temperatures and winds exhibit strong variability In addition vertical and horizontal displacements associated with these waves are significant so that the interpretation of constituent signatures becomes difficult By providing simultaneous profiles of a number of quantities of dynamical interest WaMI has the potential to resolve a number of these observational issues and to provide insights into the dynamics and constituent transport in this region These measurements would be most valuable if they were part of a multiple satellite mission tentatively termed the D-Train D for dynamics each satellite of which sampled a different local time In this talk the measurement and inversion approach being developed for WaMI is described The importance of these measurements for interpreting the behaviour of the atmosphere in the upper stratosphere and

  11. A growing-drop technique for measuring dynamic interfacial tension

    SciTech Connect

    MacLeod, C.A.; Radke, C.J.

    1993-10-01

    A novel, growing-drop technique is described for measuring dynamic interfacial tension due to sorption of surface-active solutes. The proposed method relates the instantaneous pressure and size of expanding liquid drops to interfacial tension and is useful for measuring both liquid/gas and liquid/liquid tensions over a wide range of time scales, currently from 10 ms to several hours. Growing-drop measurements on surfactant-free water/air and water/octanol interfaces yield constant tensions equal to their known literature values. For surfactant-laden, liquid drops, the growing-drop technique captures the actual transient tension evolution of a single interface, rather than interval times as with the classic maximum-drop-pressure and drop.-volume tension measurements. Dynamic tensions measured for 0.25 mM aqueous 1-decanol solution/air and 0.02 kg/m{sup 3} aqueous Triton X-100 solution/dodecane interfaces show nonmonotonic behavior, indicating slow surfactant transport relative to the imposed rates of interfacial dilatation. The dynamic tension of a purified and fresh 6 mM aqueous sodium dodecyl sulfate (SDS) solution/air interface shows only a monotonic decrease, indicating rapid surfactant transport relative to the imposed rates of dilatation. ConverselY, an aged SDS solution, naturally containing trace dodecanol impurities, exhibits dynamic tensions which reflect a superposition of the rapidly equilibrating SDS and the slowly adsorbing dodecanol.

  12. A theory of neural dimensionality, dynamics, and measurement

    NASA Astrophysics Data System (ADS)

    Ganguli, Surya

    In many experiments, neuroscientists tightly control behavior, record many trials, and obtain trial-averaged firing rates from hundreds of neurons in circuits containing millions of behaviorally relevant neurons. Dimensionality reduction has often shown that such datasets are strikingly simple; they can be described using a much smaller number of dimensions than the number of recorded neurons, and the resulting projections onto these dimensions yield a remarkably insightful dynamical portrait of circuit computation. This ubiquitous simplicity raises several profound and timely conceptual questions. What is the origin of this simplicity and its implications for the complexity of brain dynamics? Would neuronal datasets become more complex if we recorded more neurons? How and when can we trust dynamical portraits obtained from only hundreds of neurons in circuits containing millions of neurons? We present a theory that answers these questions, and test it using neural data recorded from reaching monkeys. Overall, this theory yields a picture of the neural measurement process as a random projection of neural dynamics, conceptual insights into how we can reliably recover dynamical portraits in such under-sampled measurement regimes, and quantitative guidelines for the design of future experiments. Moreover, it reveals the existence of phase transition boundaries in our ability to successfully decode cognition and behavior as a function of the number of recorded neurons, the complexity of the task, and the smoothness of neural dynamics. membership pending.

  13. Introducing variable-step topography (VST) coordinates within dynamically constrained nonhydrostatic modeling system (NMS). Part 2: VST performance on orthodox obstacle flows

    NASA Astrophysics Data System (ADS)

    Tripoli, Gregory J.; Smith, Eric A.

    2014-06-01

    In this second part of a two-part sequence of papers, the performance metrics and quantitative advantages of a new VST surface coordinate system, implemented within a dynamically constrained, nonhydrostatic, cloud mesoscale atmospheric model, are evaluated in conjunction with seven orthodox obstacle flow problems. [The first part presented a full formulation of the VST model, prefaced by a description of the framework of the newly re-tooled nonhydrostatic modeling system (NMS) operating within integral constraints based on the conservation of the foremost quantities of mass, energy and circulation.] The intent behind VST is to create a vertical surface coordinate system boundary underpinning a nonhydrostatic atmosphere capable of reliable simulations of flows over both smooth and steep terrain without sacrificing dynamical integrity over either type of surface. Model simulation results are analyzed for six classical fluid dynamics problems involving flows relative to obstacles with known analytical or laboratory-simulated solutions, as well as for a seventh noteworthy mountain wave breaking problem that has well-studied numerical solutions. For cases when topography becomes excessively severe or poorly resolved numerically, atmospheric models using transform (terrain-following) coordinates produce noteworthy errors rendering a stable integration only if the topography is smoothed. For cases when topography is slowly varying (smooth or subtle), models using discrete-step coordinates also produce noteworthy errors relative to known solutions. Alternatively, the VST model demonstrates that both limitations of the two conventional approaches, for the entire range of slope severities, can be overcome. This means that VST is ideally suited for a scalable, nonhydrostatic atmospheric model, safeguarded with physically realistic dynamical constraints.

  14. Quality control measurements for fluoroscopy systems in eight countries participating in the SENTINEL EU coordination action.

    PubMed

    Zoetelief, J; Schultz, F W; Kottou, S; Gray, L; O'Connor, U; Salat, D; Kepler, K; Kaplanis, P; Jankowski, J; Schreiner, A; Vassileva, J

    2008-01-01

    Quality control (QC) is becoming increasingly important in relation to the introduction of digital medical imaging systems using X rays. It was, therefore, decided to organise and perform a trial on image quality and physical measurements. The SENTINEL toolkit for QC measurements of fluoroscopy systems containing equipment and instructions for their use in the assessment of dose and image quality circulated among participants in the trial. The participants reported on their results. In the present contribution, the impact of the trial on the selected protocols is presented. The Medical Physics and Bioengineering protocol appeared to be useful for QC, and also for digital systems. The protocol needs an additional section, or an addition to each section, to state compliance with the requirements. The circular cross-sections of the Leeds test objects need adaptation for rectangular flat panel detector (FPD) systems. Only one participant was able to perform the monitor test using MoniQA. This is due to the fact that assistance is required from the suppliers of the X-ray systems. This problem needs to be solved to apply MoniQA in practice. PMID:18310607

  15. Scale-Independent Measures and Pathologic Cardiac Dynamics

    NASA Astrophysics Data System (ADS)

    Amaral, Luís A.; Goldberger, Ary L.; Ivanov, Plamen Ch.; Stanley, H. Eugene

    1998-09-01

    We study several scale-independent measures of cardiac interbeat interval dynamics defined through the application of the wavelet transform. We test their performance in detecting heart disease using a database consisting of records of interbeat intervals for a group of healthy individuals and subjects with congestive heart failure. We find that scale-independent measures effectively distinguish healthy from pathologic behavior and propose a new two-variable scale-independent measure that could be clinically useful. We compare the performance of a recently proposed scale-dependent measure and find that the results depend on the database analyzed and on the analyzing wavelet.

  16. Objective and automated measurement of dynamic vision functions

    NASA Technical Reports Server (NTRS)

    Flom, M. C.; Adams, A. J.

    1976-01-01

    A phoria stimulus array and electro-oculographic (EOG) arrangements for measuring motor and sensory responses of subjects subjected to stress or drug conditions are described, along with experimental procedures. Heterophoria (as oculomotor function) and glare recovery time (time required for photochemical and neural recovery after exposure to a flash stimulus) are measured, in research aimed at developing automated objective measurement of dynamic vision functions. Onset of involuntary optokinetic nystagmus in subjects attempting to track moving stripes (while viewing through head-mounted binocular eyepieces) after exposure to glare serves as an objective measure of glare recovery time.

  17. Optical feedback interferometry for measuring dynamic stress deformation of beams

    NASA Astrophysics Data System (ADS)

    Atashkhooei, Reza; Azcona, Francisco; Royo, Santiago; Espert, Lluis Gil

    2012-06-01

    An optical feedback interferometer has been used as a sensor for measuring the deformation of the beams under dynamic loading. The compactness, non-contact nature, high accuracy (below half wavelength of the laser) and the cost-effectiveness of this sensor makes it a suitable choice for material deformation measurements. A general procedure of the measurement is described in detail, including the proposed solution to deal with the speckle effect which appears when large deformations are presented. The performance of the proposed sensor has been compared and validated with a commercial contact LVDT sensor showing measurement differences below 20μm (2.9%).

  18. A method of measuring dynamic strain under electromagnetic forming conditions.

    PubMed

    Chen, Jinling; Xi, Xuekui; Wang, Sijun; Lu, Jun; Guo, Chenglong; Wang, Wenquan; Liu, Enke; Wang, Wenhong; Liu, Lin; Wu, Guangheng

    2016-04-01

    Dynamic strain measurement is rather important for the characterization of mechanical behaviors in electromagnetic forming process, but it has been hindered by high strain rate and serious electromagnetic interference for years. In this work, a simple and effective strain measuring technique for physical and mechanical behavior studies in the electromagnetic forming process has been developed. High resolution (∼5 ppm) of strain curves of a budging aluminum tube in pulsed electromagnetic field has been successfully measured using this technique. The measured strain rate is about 10(5) s(-1), which depends on the discharging conditions, nearly one order of magnitude of higher than that under conventional split Hopkins pressure bar loading conditions (∼10(4) s(-1)). It has been found that the dynamic fracture toughness of an aluminum alloy is significantly enhanced during the electromagnetic forming, which explains why the formability is much larger under electromagnetic forging conditions in comparison with conventional forging processes. PMID:27131683

  19. A method of measuring dynamic strain under electromagnetic forming conditions

    NASA Astrophysics Data System (ADS)

    Chen, Jinling; Xi, Xuekui; Wang, Sijun; Lu, Jun; Guo, Chenglong; Wang, Wenquan; Liu, Enke; Wang, Wenhong; Liu, Lin; Wu, Guangheng

    2016-04-01

    Dynamic strain measurement is rather important for the characterization of mechanical behaviors in electromagnetic forming process, but it has been hindered by high strain rate and serious electromagnetic interference for years. In this work, a simple and effective strain measuring technique for physical and mechanical behavior studies in the electromagnetic forming process has been developed. High resolution (˜5 ppm) of strain curves of a budging aluminum tube in pulsed electromagnetic field has been successfully measured using this technique. The measured strain rate is about 105 s-1, which depends on the discharging conditions, nearly one order of magnitude of higher than that under conventional split Hopkins pressure bar loading conditions (˜104 s-1). It has been found that the dynamic fracture toughness of an aluminum alloy is significantly enhanced during the electromagnetic forming, which explains why the formability is much larger under electromagnetic forging conditions in comparison with conventional forging processes.

  20. Enhanced crosslimb transfer of force-field learning for dynamics that are identical in extrinsic and joint-based coordinates for both limbs

    PubMed Central

    de Rugy, Aymar; Howard, Ian S.; Ingram, James N.; Wolpert, Daniel M.

    2015-01-01

    Humans are able to adapt their motor commands to make accurate movements in novel sensorimotor environments, such as when wielding tools that alter limb dynamics. However, it is unclear to what extent sensorimotor representations, obtained through experience with one limb, are available to the opposite, untrained limb and in which form they are available. Here, we compared crosslimb transfer of force-field compensation after participants adapted to a velocity-dependent curl field, oriented either in the sagittal or the transverse plane. Due to the mirror symmetry of the limbs, the force field had identical effects for both limbs in joint and extrinsic coordinates in the sagittal plane but conflicting joint-based effects in the transverse plane. The degree of force-field compensation exhibited by the opposite arm in probe trials immediately after initial learning was significantly greater after sagittal (26 ± 5%) than transverse plane adaptation (9 ± 4%; P < 0.001), irrespective of whether participants learned initially with the left or the right arm or via abrupt or gradual exposure to the force field. Thus transfer was impaired when the orientation of imposed dynamics conflicted in intrinsic coordinates for the two limbs. The data reveal that neural representations of novel dynamics are only partially available to the opposite limb, since transfer is incomplete even when force-field perturbation is spatially compatible for the two limbs, according to both intrinsic and extrinsic coordinates. PMID:26581867

  1. Coordinated thermospheric day-night airglow and ionospheric measurements from low latitudes—First results

    NASA Astrophysics Data System (ADS)

    Taori, Alok; Sridharan, R.; Chakrabarty, D.; Narayanan, R.; Ramarao, P. V. S.

    2001-04-01

    The Dayglow photometer which monitors the O(¹D) 630.0 nm thermospheric airglow emission, has been converted into a day-night photometer and was operated from Waltair (17.7°N, 83.3°E dip. Lat. 10.09°N) during March 1998 as a part of the Indian Solar Terrestrial Energy Programme (ISTEP) campaign. The first results on the day-night airglow measurements together with ionosonde data from the same location are scrutinized in the present exercise. The base height of the F-layer (h'F) showed a strong negative correlation with dayglow intensity similar to nighttime conditions and a new empirical relation (Barbier type) linking the F-region electron densities and the h'F with the dayglow intensity has been worked out highlighting the importance of chemical processes in OI 630.0 nm dayglow and its variabilities.

  2. Deciphering Jupiter's atmospheric dynamics using the upcoming Juno gravity measurements

    NASA Astrophysics Data System (ADS)

    Kaspi, Yohai; Galanti, Eli

    2016-07-01

    This summer, the Juno spacecraft will arrive at Jupiter in course for close flybys of the planet, obtaining a high precision gravity spectrum of Jupiter. This data can be used to estimate the depth of Jupiter's observed cloud-level wind, and decipher the possible internal flows, that might be decoupled from the surface wind. In this talk, we discuss the Juno gravity experiment, and the possible outcomes with regard to the flows on Jupiter. We show several ways in which the gravity spectrum might be used to study the large scale flows: 1. measurements of the high order even harmonics which beyond J10 are dominated by the dynamics; 2. measurements of odd gravity harmonics which have no contribution from a static planet, and therefore are a pure signature of dynamics; 3. upper limits on the depth of the surface flow can be obtained by comparing low order even harmonics from dynamical models to the difference between the measured low order even harmonics and the largest possible values of a static planet; 4. direct latitudinally varying measurements of the gravity field exerted on the spacecraft. We will discuss how these methods may be applied given the expected sensitivities of the Juno gravity experiment. In addition, we present an inverse adjoint model, which allows given the gravity data, to infer the flows that produce it. This will allow, hopefully, to make significant progress in one of the longest-standing question in planetary atmospheric dynamics regarding the nature of the flows on the giant planets.

  3. Dynamic measurements of gear tooth friction and load

    NASA Technical Reports Server (NTRS)

    Rebbechi, Brian; Oswald, Fred B.; Townsend, Dennis P.

    1991-01-01

    As part of a program to study fundamental mechanisms of gear noise, static and dynamic gear tooth strain measurements were made on the NASA gear-noise rig. Tooth-fillet strains from low-contact ratio-spur gears were recorded for 28 operating conditions. A method is introduced whereby strain gage measurements taken from both the tension and compression sides of a gear tooth can be transformed into the normal and frictional loads on the tooth. This technique was applied to both the static and dynamic strain data. The static case results showed close agreement with expected results. For the dynamic case, the normal-force computation produced very good results, but the friction results, although promising, were not as accurate. Tooth sliding friction strongly affected the signal from the strain gage on the tensionside of the tooth. The compression gage was affected by friction to a much lesser degree. The potential of the method to measure friction force was demonstrated, but further refinement will be required before this technique can be used to measure friction forces dynamically with an acceptable degree of accuracy.

  4. Unitary dynamics and finite-time measurements: a case study

    NASA Astrophysics Data System (ADS)

    Prinz-Zwick, Andreas; Ingold, Gert-Ludwig; Talkner, Peter

    2015-10-01

    The inhibition of the decay of a quantum system by frequent measurements is known as quantum Zeno effect. Beyond the limit of projective measurements, the interplay between the unitary dynamics of the system and the coupling to a measurement apparatus becomes relevant. We explore this interplay by considering a quantum particle moving on a one-dimensional chain. A local measurement by coupling to an apparatus with a two-dimensional Hilbert space detects the presence of the particle on a specific chain site. The decay of the population is studied analytically for a two-site chain and numerically for a larger system as a function of the measurement time and the time between subsequent measurements. Particular attention is given to the shift of the energy of the measured site due to the coupling to the apparatus. The decay of the initial population can be hindered or accelerated, depending on the chosen system and the coupling parameters.

  5. Electron energy budget in the high-latitude ionosphere during Viking/EISCAT coordinated measurements

    SciTech Connect

    Lilensten, J.; Kofman, W.; Lathuillere, C. ); Fontaine, D. ); Eliasson, L. ); Oran, E.S. )

    1990-05-01

    The magnetospheric electron fluxes precipitating at the top of the auroral ionosphere contribute to the production of ionization, to the excitation of atmospheric constituents, and to the heating of the ambient electrons. This last process occurs essentially when the energy of the initial precipitated electrons and photoelectrons has been degraded to values lower than approximately 10 eV. The heated ambient electron gas loses this energy to the neutral gas and ambient ions. Finally, the temperature gradient produced in the ionospheric plasma induces a heat flux. In the absence of an electric field and for stationary conditions, the energy budget of ionospheric electrons results from the balance between these processes of heating, cooling, and heat conduction. The intensity of these different processes is quantitatively computed at each altitude in the ionosphere by combining simultaneous EISCAT and Viking in situ measurements, and by means of an electron transport model. The stationary electron flux, which leads to the heating rate, is computed, and remaining differences in the energy budget are discussed.

  6. Deciphering Jupiter's complex flow dynamics using the upcoming Juno gravity measurements and an adjoint based dynamical model

    NASA Astrophysics Data System (ADS)

    Galanti, Eli; Kaspi, Yohai

    2015-11-01

    The nature of the large scale flow on Jupiter below the cloud level is still unknown. The observed surface wind might be confined to the upper layers, or be a manifestation of deep cylindrical flow. Moreover, it is possible that in the case where the observed wind is superficial, there exists deep flow that is completely separated from the surface. To date, all models linking the wind (via the induced density nomalies) to the gravity field to be measured by Juno, consider only wind flow related to the observed could level wind. Some assume full cylindrical flow while others allow for the wind to decay with depth.Here we explore the possibility of complex wind dynamics that include both the upper-layer wind, and a deep flow that is completely detached from the flow above it. The surface flow is based on the observed cloud level flow and is set to decay with depth. The deep flow is constructed synthetically to produce cylindrical structures with variable width and magnitude, thus allowing for a wide range of possible setups of the unknown deep flow. This flow is also set to decay when approaching the surface flow in coordination with the exponential decay rate. The combined 3D flow is then related to the density anomalies via a dynamical model, taking into account oblateness effects as well, and the resulting density field is then used to calculate the gravitational moments. An adjoint inverse model is constructed for the dynamical model, thus allowing backward integration of the dynamical model, from the expected observations of the gravity moments to the parameters controlling the setup of the deep and surface flows. We show that the model can be used for examination of various scenarios, including cases in which the deep flow is dominating over the surface wind. The novelty of our adjoint based inversion approach is in the ability to identify complex dynamics including deep cylindrical flows that have no manifestation in the observed cloud-level wind. Furthermore

  7. In-flight measurement of upwind dynamic soaring in albatrosses

    NASA Astrophysics Data System (ADS)

    Sachs, Gottfried

    2016-03-01

    In-flight measurement results on upwind flight of albatrosses using dynamic soaring are presented. It is shown how the birds manage to make progress against the wind on the basis of small-scale dynamic soaring maneuvers. For this purpose, trajectory features, motion quantities and mechanical energy relationships as well as force characteristics are analyzed. The movement on a large-scale basis consists of a tacking type flight technique which is composed of dynamic soaring cycle sequences with alternating orientation to the left and right. It is shown how this is performed by the birds so that they can achieve a net upwind flight without a transversal large-scale movement and how this compares with downwind or across wind flight. Results on upwind dynamic soaring are presented for low and high wind speed cases. It is quantified how much the tacking trajectory length is increased when compared with the beeline distance. The presented results which are based on in-flight measurements of free flying albatrosses were achieved with an in-house developed GPS-signal tracking method yielding the required high precision for the small-scale dynamic soaring flight maneuvers.

  8. Analysis of in situ measurements of cirrus anvil outflow dynamics

    NASA Astrophysics Data System (ADS)

    Lederman, J. I.; Whiteway, J. A.

    2012-12-01

    The airborne campaign, EMERALD 2 (Egrett Microphysics Experiment with Radiation, Lidar, and Dynamics,) was conducted out of Darwin, Australia in 2002. Objectives included characterization of the dynamics in the cirrus anvil outflow from tropical deep convection. Two aircraft, the Egrett and King Air, were flown in tandem in the upper troposphere (7 km - 15 km) to collect in situ measurements in the anvil outflow from a storm named "Hector" that occurs on a regular basis over the Tiwi Islands north of Darwin during November and December. Turbulence probes mounted on the wings of the Egrett aircraft were used to measure the wind fluctuations across the anvil and along its length with a spatial resolution of 2 meters. The in situ measurements from the Egrett were coincident with lidar measurements of the cloud structure from the King Air aircraft flying directly below. The presentation will show results of the analysis of the measurements with an emphasis on the turbulence, gravity waves, and coherent structures that are particular to the cirrus anvil outflow environment. Emphasis is placed on the dynamics associated with the generation of mammatus formations at the base of the anvil clouds.

  9. Correlation of Spatially Filtered Dynamic Speckles in Distance Measurement Application

    SciTech Connect

    Semenov, Dmitry V.; Nippolainen, Ervin; Kamshilin, Alexei A.; Miridonov, Serguei V.

    2008-04-15

    In this paper statistical properties of spatially filtered dynamic speckles are considered. This phenomenon was not sufficiently studied yet while spatial filtering is an important instrument for speckles velocity measurements. In case of spatial filtering speckle velocity information is derived from the modulation frequency of filtered light power which is measured by photodetector. Typical photodetector output is represented by a narrow-band random noise signal which includes non-informative intervals. Therefore more or less precious frequency measurement requires averaging. In its turn averaging implies uncorrelated samples. However, conducting research we found that correlation is typical property not only of dynamic speckle patterns but also of spatially filtered speckles. Using spatial filtering the correlation is observed as a response of measurements provided to the same part of the object surface or in case of simultaneously using several adjacent photodetectors. Found correlations can not be explained using just properties of unfiltered dynamic speckles. As we demonstrate the subject of this paper is important not only from pure theoretical point but also from the point of applied speckle metrology. E.g. using single spatial filter and an array of photodetector can greatly improve accuracy of speckle velocity measurements.

  10. Measurements of nuclear spin dynamics by spin-noise spectroscopy

    SciTech Connect

    Ryzhov, I. I.; Poltavtsev, S. V.; Kozlov, G. G.; Zapasskii, V. S.; Kavokin, K. V.; Glazov, M. M.; Vladimirova, M.; Scalbert, D.; Cronenberger, S.; Lemaître, A.; Bloch, J.

    2015-06-15

    We exploit the potential of the spin noise spectroscopy (SNS) for studies of nuclear spin dynamics in n-GaAs. The SNS experiments were performed on bulk n-type GaAs layers embedded into a high-finesse microcavity at negative detuning. In our experiments, nuclear spin polarisation initially prepared by optical pumping is monitored in real time via a shift of the peak position in the electron spin noise spectrum. We demonstrate that this shift is a direct measure of the Overhauser field acting on the electron spin. The dynamics of nuclear spin is shown to be strongly dependent on the electron concentration.

  11. Methodology of the Westinghouse dynamic rod worth measurement technique

    SciTech Connect

    Chao, Y.A.; Chapman, D.M.; Easter, M.E.; Hill, D.J.; Hoerner, J.A. ); Kurtz, P.N. )

    1992-01-01

    During zero-power physics testing, plant operations personnel use one of various techniques to measure the reactivity worth of the control rods to confirm shutdown margin. A simple and fast procedure for measuring rod worths called dynamic rod worth measurement (DRWM) has been developed at Westinghouse. This procedure was tested at the recent startups of Point Beach Nuclear Power Plant Unit 1 cycle 20 and Unit 2 cycle 18. The results of these tests show that DRWM measures rod worths with accuracy comparable to that of both boron dilution and rod bank exchange measurements. The DRWM procedure is a fast process of measuring the reactivity worth of individual banks by inserting and withdrawing the bank continuously at the maximum stepping speed without changing the boron concentration and recording the signals of the ex-core detectors.

  12. Multiple Point Dynamic Gas Density Measurements Using Molecular Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard; Panda, Jayanta

    1999-01-01

    A nonintrusive technique for measuring dynamic gas density properties is described. Molecular Rayleigh scattering is used to measure the time-history of gas density simultaneously at eight spatial locations at a 50 kHz sampling rate. The data are analyzed using the Welch method of modified periodograms to reduce measurement uncertainty. Cross-correlations, power spectral density functions, cross-spectral density functions, and coherence functions may be obtained from the data. The technique is demonstrated using low speed co-flowing jets with a heated inner jet.

  13. 3D surface coordinate inspection of formed sheet material parts using optical measurement systems and virtual distortion compensation

    NASA Astrophysics Data System (ADS)

    Weckenmann, Albert A.; Gall, P.; Gabbia, A.

    2005-02-01

    Modern forming technology allows the production of highly sophisticated free form sheet material components, affording great flexibility to the design and manufacturing processes across a wide range of industries. This increased design and manufacturing potential places an ever growing demand on the accompanying inspection metrology. As a consequence of their surface shape, these parts underlie a reversible geometrical deformation caused by variations of the material and the manufacturing process, as well as by gravity. This distortion is removed during the assembly process, usually performed in automated robotic processes. For this reason, the part's tolerated parameters have to be inspected in a defined state, simulating the assembly process' boundary conditions. Thus, the inspection process chain consists of six steps: picking the workpiece up, manual fixation of the workpiece, tactile measurement of the surface's coordinates using a defined measurement strategy, manual removal of the fixation and removal of the workpiece from the inspection area. These steps are both laborious and time consuming (for example, the inspection of a car door can take up to a working day to complete). Using optical measuring systems and virtual distortion compensation, this process chain can be dramatically shortened. Optical measuring systems provide as a measurement result a point cloud representing a sample of all nearest surfaces in the measuring range containing the measurand. From this data, a surface model of the measurand can be determined, independent of its position in the measuring range. For thin sheet material parts an approximating finite element model can be deduced from such a surface model. By means of pattern recognition, assembly relevant features of the measurand can be identified and located on this model. Together with the boundary conditions given by the assembly process, the shape of the surface in its assembled state can be calculated using the finite

  14. Indentation Measurements to Validate Dynamic Elasticity Imaging Methods.

    PubMed

    Altahhan, Khaldoon N; Wang, Yue; Sobh, Nahil; Insana, Michael F

    2016-09-01

    We describe macro-indentation techniques for estimating the elastic modulus of soft hydrogels. Our study describes (a) conditions under which quasi-static indentation can validate dynamic shear-wave imaging estimates and (b) how each of these techniques uniquely biases modulus estimates as they couple to the sample geometry. Harmonic shear waves between 25 and 400 Hz were imaged using ultrasonic Doppler and optical coherence tomography methods to estimate shear dispersion. From the shear-wave speed of sound, average elastic moduli of homogeneous samples were estimated. These results are compared directly with macroscopic indentation measurements measured two ways. One set of measurements applied Hertzian theory to the loading phase of the force-displacement curves using samples treated to minimize surface adhesion forces. A second set of measurements applied Johnson-Kendall-Roberts theory to the unloading phase of the force-displacement curve when surface adhesions were significant. All measurements were made using gelatin hydrogel samples of different sizes and concentrations. Agreement within 5% among elastic modulus estimates was achieved for a range of experimental conditions. Consequently, a simple quasi-static indentation measurement using a common gel can provide elastic modulus measurements that help validate dynamic shear-wave imaging estimates. PMID:26376923

  15. Real-Time Dynamics Monitoring System with Synchronized Phasor Measurements

    Energy Science and Technology Software Center (ESTSC)

    2005-01-01

    The Real-Time Dynamics Monitoring System is designed to monitor the dynamics within the power grid and assess the system behavior during normal and disturbance conditions. The RTDMS application was built on the Grid-3P technology platform and takes real-time information collected by Synchronized Phasor Measurement Units (PMU5) or other collection devices and transmitted to a central Phasor Data Concentrator (PDC) for monitoring grid dynamics. The data is sampled 30 times per second and is time-synchronized. Thismore » data is processed to create graphical and geographical displays to provide visualization for frequency/frequency response, voltage magnitudes and angles, voltage angle differences across critical paths as well as real and reactive power-flows on a sub-second and second basis. Software allows for monitoring, tracking, historical data archiving and electric system troubleshooting for reliability management.« less

  16. The application of co-ordination dynamics to the analysis of discrete movements using table-tennis as a paradigm skill.

    PubMed

    Sørensen, V; Ingvaldsen, R P; Whiting, H T

    2001-07-01

    The purpose of this experiment was to explore the application of co-ordination dynamics to the analysis of discrete rather than cyclical movements. Subjects, standing in a fixed position, were required to return table-tennis balls delivered to different spatial locations in the direction of a fixed target. This was achieved in condition 1 by systematically scaling, from left to right and vice versa, the 'spatial location' of the ball-identified as a control parameter. In condition 2, the control condition, the spatial location was varied randomly over the same range. The changes between regimes of the stroke co-ordination pattern, defined at two different levels, (1) organisational--forehand or backhand drive. and (2) kinematic-the distance of the bat at ball-bat contact relative to the leading edge of the table, were identified as collective variables, the values of which changed spontaneously at the transition points exposed by the control parameter. The switch between regimes was shown to be dependent upon the direction of scaling, i.e. a hysteresis effect was identified in both conditions. These findings confirm that the conceptual and methodological frameworks of co-ordination dynamics can be applied, appropriately, to the analysis of discrete movements. Moreover, it would seem that control parameter values (spatial location of the ball) do not necessarily have to be scaled in a systematic way in order to produce the required effects. PMID:11471838

  17. Effects of a mu-opioid receptor agonist (codeine phosphate) on visuo-motor coordination and dynamic visual acuity in man.

    PubMed Central

    Bradley, C M; Nicholson, A N

    1986-01-01

    Effects of codeine (30, 60 and 90 mg) on visuo-motor coordination and dynamic visual acuity, together with critical flicker fusion, digit symbol substitution, complex reaction time and subjective assessments of mood, were studied from 0.75-2.0 h after ingestion by six healthy female adults. The study was double-blind and placebo controlled, and triprolidine (10 mg) was used as the active control. The effect on visuo-motor coordination was limited and was dose related and linear, and performance was altered on visuo-motor coordination with 60 and 90 mg codeine, and on dynamic visual acuity with 90 mg codeine (P less than 0.05). No other effect of codeine was detected. Modulated neuromuscular function is likely to be the common denominator of the changes in performance with codeine, though nausea, but not sedation, may be a contributory factor. It is possible that altered performance with codeine may involve interactions with different receptors than those which lead to sedation. PMID:3024689

  18. Symplectic coordinates on S×S for perturbed Keplerian problems: Application to the dynamics of a generalised Størmer problem

    NASA Astrophysics Data System (ADS)

    Iñarrea, Manuel; Lanchares, Víctor; Palacián, Jesús F.; Pascual, Ana I.; Salas, J. Pablo; Yanguas, Patricia

    In order to analyse the dynamics of a given Hamiltonian system in the space defined as the Cartesian product of two spheres, we propose to combine Delaunay coordinates with Poincaré-like coordinates. The coordinates are of local character and have to be selected accordingly with the type of motions one has to take into consideration, so we distinguish the following types: (i) rectilinear motions; (ii) circular and equatorial motions; (iii) circular non-equatorial motions; (iv) non-circular equatorial motions; and (v) non-circular and non-equatorial motions. We apply the theory to study the dynamics of the reduced flow of a generalised Størmer problem that is modelled as a perturbation of the Kepler problem. After using averaging and reduction theories, the corresponding flow is analysed on the manifold S×S, calculating the occurring equilibria and their stability. Finally, the flow of the original problem is reconstructed, concluding the existence of some families of periodic solutions and KAM tori.

  19. A Dynamic Attitude Measurement System Based on LINS

    PubMed Central

    Li, Hanzhou; Pan, Quan; Wang, Xiaoxu; Zhang, Juanni; Li, Jiang; Jiang, Xiangjun

    2014-01-01

    A dynamic attitude measurement system (DAMS) is developed based on a laser inertial navigation system (LINS). Three factors of the dynamic attitude measurement error using LINS are analyzed: dynamic error, time synchronization and phase lag. An optimal coning errors compensation algorithm is used to reduce coning errors, and two-axis wobbling verification experiments are presented in the paper. The tests indicate that the attitude accuracy is improved 2-fold by the algorithm. In order to decrease coning errors further, the attitude updating frequency is improved from 200 Hz to 2000 Hz. At the same time, a novel finite impulse response (FIR) filter with three notches is designed to filter the dither frequency of the ring laser gyro (RLG). The comparison tests suggest that the new filter is five times more effective than the old one. The paper indicates that phase-frequency characteristics of FIR filter and first-order holder of navigation computer constitute the main sources of phase lag in LINS. A formula to calculate the LINS attitude phase lag is introduced in the paper. The expressions of dynamic attitude errors induced by phase lag are derived. The paper proposes a novel synchronization mechanism that is able to simultaneously solve the problems of dynamic test synchronization and phase compensation. A single-axis turntable and a laser interferometer are applied to verify the synchronization mechanism. The experiments results show that the theoretically calculated values of phase lag and attitude error induced by phase lag can both match perfectly with testing data. The block diagram of DAMS and physical photos are presented in the paper. The final experiments demonstrate that the real-time attitude measurement accuracy of DAMS can reach up to 20″ (1σ) and the synchronization error is less than 0.2 ms on the condition of three axes wobbling for 10 min. PMID:25177802

  20. A dynamic attitude measurement system based on LINS.

    PubMed

    Li, Hanzhou; Pan, Quan; Wang, Xiaoxu; Zhang, Juanni; Li, Jiang; Jiang, Xiangjun

    2014-01-01

    A dynamic attitude measurement system (DAMS) is developed based on a laser inertial navigation system (LINS). Three factors of the dynamic attitude measurement error using LINS are analyzed: dynamic error, time synchronization and phase lag. An optimal coning errors compensation algorithm is used to reduce coning errors, and two-axis wobbling verification experiments are presented in the paper. The tests indicate that the attitude accuracy is improved 2-fold by the algorithm. In order to decrease coning errors further, the attitude updating frequency is improved from 200 Hz to 2000 Hz. At the same time, a novel finite impulse response (FIR) filter with three notches is designed to filter the dither frequency of the ring laser gyro (RLG). The comparison tests suggest that the new filter is five times more effective than the old one. The paper indicates that phase-frequency characteristics of FIR filter and first-order holder of navigation computer constitute the main sources of phase lag in LINS. A formula to calculate the LINS attitude phase lag is introduced in the paper. The expressions of dynamic attitude errors induced by phase lag are derived. The paper proposes a novel synchronization mechanism that is able to simultaneously solve the problems of dynamic test synchronization and phase compensation. A single-axis turntable and a laser interferometer are applied to verify the synchronization mechanism. The experiments results show that the theoretically calculated values of phase lag and attitude error induced by phase lag can both match perfectly with testing data. The block diagram of DAMS and physical photos are presented in the paper. The final experiments demonstrate that the real-time attitude measurement accuracy of DAMS can reach up to 20″ (1σ) and the synchronization error is less than 0.2 ms on the condition of three axes wobbling for 10 min. PMID:25177802

  1. Plasma crystal dynamics measured with a three-dimensional plenoptic camera.

    PubMed

    Jambor, M; Nosenko, V; Zhdanov, S K; Thomas, H M

    2016-03-01

    Three-dimensional (3D) imaging of a single-layer plasma crystal was performed using a commercial plenoptic camera. To enhance the out-of-plane oscillations of particles in the crystal, the mode-coupling instability (MCI) was triggered in it by lowering the discharge power below a threshold. 3D coordinates of all particles in the crystal were extracted from the recorded videos. All three fundamental wave modes of the plasma crystal were calculated from these data. In the out-of-plane spectrum, only the MCI-induced hot spots (corresponding to the unstable hybrid mode) were resolved. The results are in agreement with theory and show that plenoptic cameras can be used to measure the 3D dynamics of plasma crystals. PMID:27036775

  2. Plasma crystal dynamics measured with a three-dimensional plenoptic camera

    NASA Astrophysics Data System (ADS)

    Jambor, M.; Nosenko, V.; Zhdanov, S. K.; Thomas, H. M.

    2016-03-01

    Three-dimensional (3D) imaging of a single-layer plasma crystal was performed using a commercial plenoptic camera. To enhance the out-of-plane oscillations of particles in the crystal, the mode-coupling instability (MCI) was triggered in it by lowering the discharge power below a threshold. 3D coordinates of all particles in the crystal were extracted from the recorded videos. All three fundamental wave modes of the plasma crystal were calculated from these data. In the out-of-plane spectrum, only the MCI-induced hot spots (corresponding to the unstable hybrid mode) were resolved. The results are in agreement with theory and show that plenoptic cameras can be used to measure the 3D dynamics of plasma crystals.

  3. Dynamic tread wear measurement method for train wheels against vibrations.

    PubMed

    Chen, Xu; Sun, Junhua; Liu, Zhen; Zhang, Guangjun

    2015-06-10

    Dynamic tread wear measurement is difficult but significant for railway transportation safety and efficiency. The accuracy of existing methods is inclined to be affected by environmental vibrations since they are highly dependent on the accurate calibration of the relative pose between vision sensors. In this paper, we present a method to obtain full wheel profiles based on automatic registration of vision sensor data instead of traditional global calibrations. We adopt two structured light vision sensors to recover the inner and outer profiles of each wheel, and register them by the iterative closest point algorithm. Computer simulations show that the proposed method is insensitive to noises and relative pose vibrations. Static experiments demonstrate that our method has high accuracy and great repeatability. Dynamic experiments show that the measurement accuracy of our method is about 0.18 mm, which is a twofold improvement over traditional methods. PMID:26192824

  4. Myosin II Motors and F-Actin Dynamics Drive the Coordinated Movement of the Centrosome and Soma during CNS Glial-Guided Neuronal Migration

    SciTech Connect

    Solecki, Dr. David; Trivedi, Dr. Niraj; Govek, Eve-Ellen; Kerekes, Ryan A; Gleason, Shaun Scott; Hatten, Mary E

    2009-01-01

    Lamination of cortical regions of the vertebrate brain depends on glial-guided neuronal migration. The conserved polarity protein Par6{alpha} localizes to the centrosome and coordinates forward movement of the centrosome and soma in migrating neurons. The cytoskeletal components that produce this unique form of cell polarity and their relationship to polarity signaling cascades are unknown. We show that F-actin and Myosin II motors are enriched in the neuronal leading process and that Myosin II activity is necessary for leading process actin dynamics. Inhibition of Myosin II decreased the speed of centrosome and somal movement, whereas Myosin II activation increased coordinated movement. Ectopic expression or silencing of Par6{alpha} inhibited Myosin II motors by decreasing Myosin light-chain phosphorylation. These findings suggest leading-process Myosin II may function to 'pull' the centrosome and soma forward during glial-guided migration by a mechanism involving the conserved polarity protein Par6{alpha}.

  5. Measuring contemporary crustal motions; NASA’s Crustal Dynamics Project

    USGS Publications Warehouse

    Frey, H. V.; Bosworth, J. M.

    1988-01-01

    In this article we describe briefly the two space geodetic techniques and how they are used by the Crustal Dynamics Project, show some of the very exciting results that have emerged at the halfway point in the project's life, describe the availability and utilization of the data being collected, and consider what the future may hold when measurement accuracies eventually exceed even those now available and when other international groups become more heavily involved.   

  6. Dynamic CT perfusion measurement in a cardiac phantom.

    PubMed

    Ziemer, Benjamin P; Hubbard, Logan; Lipinski, Jerry; Molloi, Sabee

    2015-10-01

    Widespread clinical implementation of dynamic CT myocardial perfusion has been hampered by its limited accuracy and high radiation dose. The purpose of this study was to evaluate the accuracy and radiation dose reduction of a dynamic CT myocardial perfusion technique based on first pass analysis (FPA). To test the FPA technique, a pulsatile pump was used to generate known perfusion rates in a range of 0.96-2.49 mL/min/g. All the known perfusion rates were determined using an ultrasonic flow probe and the known mass of the perfusion volume. FPA and maximum slope model (MSM) perfusion rates were measured using volume scans acquired from a 320-slice CT scanner, and then compared to the known perfusion rates. The measured perfusion using FPA (P(FPA)), with two volume scans, and the maximum slope model (P(MSM)) were related to known perfusion (P(K)) by P(FPA) = 0.91P(K) + 0.06 (r = 0.98) and P(MSM) = 0.25P(K) - 0.02 (r = 0.96), respectively. The standard error of estimate for the FPA technique, using two volume scans, and the MSM was 0.14 and 0.30 mL/min/g, respectively. The estimated radiation dose required for the FPA technique with two volume scans and the MSM was 2.6 and 11.7-17.5 mSv, respectively. Therefore, the FPA technique can yield accurate perfusion measurements using as few as two volume scans, corresponding to approximately a factor of four reductions in radiation dose as compared with the currently available MSM. In conclusion, the results of the study indicate that the FPA technique can make accurate dynamic CT perfusion measurements over a range of clinically relevant perfusion rates, while substantially reducing radiation dose, as compared to currently available dynamic CT perfusion techniques. PMID:26156231

  7. Measurements of combustion dynamics with laser-based diagnostic techniques

    NASA Astrophysics Data System (ADS)

    Kang, Dal Mo

    Since the early days of gas turbine engines, combustion/flow instability inside the combustor has been an issue in many engines, but little has been understood as to how the dynamics of the system involved contribute to the instability. The primary objective of this work is to provide general experimental procedures and to validate methods for examining the dynamic behaviors of combustion systems, and to provide accurate measurements of the combustion dynamics for use as a foundation for further theoretical and numerical research. Knowledge of the fundamental dynamics of combustion systems is crucial in understanding and modeling the flame behavior and enabling the use of insights in design process and for creating robust active control of combustors. Since mixing plays significant roles in combustion processes, the dynamics of fuel/air mixing were studied. A non-premixed burner was examined with acoustic excitations at 22˜55 Hz to assess the mixing and its relation to the thermo-acoustic coupling. Phase-resolved acetone-PLIF was used to image the mixing, and from this the unmixedness was calculated, which quantifies the degree of mixing. The results show that (1) the acoustic waves induce periodicity in the degree of mixing; (2) the way the unmixedness behaves coincides well with the behavior of the Rayleigh index, implying the degree of mixing is a major factor in determining the stability of the combustion system; (3) the two-dimensional measurements of temporal unmixedness effectively visualize the shear mixing zone. A second low-swirl premixed burner was studied to examine the impact of acoustic waves on the combustion dynamics. Measurements were performed with OH-PLIF, with acoustic forcing up to 400 Hz. Swirl burners at higher pressure are industry standard, and this study examined the dynamics at elevated combustor pressure. The results show that (1) the thermo-acoustic coupling seems to be closely coupled to the vortices generated at the flame boundary

  8. Decentralized coordination through digital technology, dynamic pricing, and Customer-Driven control: the GridWise testbed demonstration project

    SciTech Connect

    Chassin, David P.; Kiesling, Lynne

    2008-10-15

    The project highlights the idea that technology-enabled decentralized coordination can achieve the same, or better, economic and reliability benefits when compared to utility-focused centralized physical and economic control. Among the design's unique features was a retail double auction with five-minute market-clearing intervals that included residential customers as direct, active market participants. (author)

  9. TECHNICAL DESIGN NOTE: An iterative neighborhood search approach for minimum zone circularity evaluation from coordinate measuring machine data

    NASA Astrophysics Data System (ADS)

    Cui, Changcai; Fan, Wei; Huang, Fugui

    2010-02-01

    An iterative neighborhood search approach (INSA) was proposed to precisely evaluate the circularity error under minimum zone conditions without directly solving nonlinear equations from coordinate measurement machine (CMM) data. The method starts with calculating the initial location and radius of an initial circular search scope. The location is the center of the circle based on an approximate least-squares method of all measurement data points uniformly sampled around the circle, and the radius is the circularity error value by using the approximate center as the datum center of two concentric circles enclosing all measurement data points. Then the circular search scope was divided according to some concentric circles and radials with some radius and angle step lengths. Intersections of the circles and radials were candidate centers for circularity evaluation under the minimum zone criteria. An optimal center with minimum circularity error value was picked out as a new location of the search scope. The distance from the old location was the radius of the new search scope. Further it was divided and the intersections were evaluated until the optimal solution was met. Some examples in the literature were used to verify the validity of this method. The results are the same as or better than those minimum zone solutions adopted from previous work, and computation time is no more than 0.07 s implementing on an IBM ThinkPad R40 laptop for all examples. The computation and comparison show that the proposed INSA is a precise, fast, convergent and simple approach which solved circularity evaluation problems effectively.

  10. Dynamic friction measurements on living HeLa cells

    NASA Astrophysics Data System (ADS)

    Goulet, Marc-Antoni; Colbert, Marie-Josée; Dalnoki-Veress, Kari

    2008-03-01

    The interaction of cells with various interfaces, and especially man-made surfaces, is an active field of research. In our experiment we use a micropipette to measure both the friction and normal force as a cell slides across a surface. A thin substrate, coated with Poly-L-Lysine is brought into contact with a HeLa cell. The adjustable substrate motion is used to study the response of the cell at various normal forces and speeds. Analysis of the micropipette provides dynamic measurements of both the friction and normal force. With our novel setup we are able to probe the attachment/detachment process of living cells.

  11. Considering Measurement Model Parameter Errors in Static and Dynamic Systems

    NASA Astrophysics Data System (ADS)

    Woodbury, Drew P.; Majji, Manoranjan; Junkins, John L.

    2011-07-01

    In static systems, state values are estimated using traditional least squares techniques based on a redundant set of measurements. Inaccuracies in measurement model parameter estimates can lead to significant errors in the state estimates. This paper describes a technique that considers these parameters in a modified least squares framework. It is also shown that this framework leads to the minimum variance solution. Both batch and sequential (recursive) least squares methods are described. One static system and one dynamic system are used as examples to show the benefits of the consider least squares methodology.

  12. Generalized Dynamic Factor Models for Mixed-Measurement Time Series

    PubMed Central

    Cui, Kai; Dunson, David B.

    2013-01-01

    In this article, we propose generalized Bayesian dynamic factor models for jointly modeling mixed-measurement time series. The framework allows mixed-scale measurements associated with each time series, with different measurements having different distributions in the exponential family conditionally on time-varying latent factor(s). Efficient Bayesian computational algorithms are developed for posterior inference on both the latent factors and model parameters, based on a Metropolis Hastings algorithm with adaptive proposals. The algorithm relies on a Greedy Density Kernel Approximation (GDKA) and parameter expansion with latent factor normalization. We tested the framework and algorithms in simulated studies and applied them to the analysis of intertwined credit and recovery risk for Moody’s rated firms from 1982–2008, illustrating the importance of jointly modeling mixed-measurement time series. The article has supplemental materials available online. PMID:24791133

  13. Generalized Dynamic Factor Models for Mixed-Measurement Time Series.

    PubMed

    Cui, Kai; Dunson, David B

    2014-02-12

    In this article, we propose generalized Bayesian dynamic factor models for jointly modeling mixed-measurement time series. The framework allows mixed-scale measurements associated with each time series, with different measurements having different distributions in the exponential family conditionally on time-varying latent factor(s). Efficient Bayesian computational algorithms are developed for posterior inference on both the latent factors and model parameters, based on a Metropolis Hastings algorithm with adaptive proposals. The algorithm relies on a Greedy Density Kernel Approximation (GDKA) and parameter expansion with latent factor normalization. We tested the framework and algorithms in simulated studies and applied them to the analysis of intertwined credit and recovery risk for Moody's rated firms from 1982-2008, illustrating the importance of jointly modeling mixed-measurement time series. The article has supplemental materials available online. PMID:24791133

  14. The Neural Network In Coordinate Transformation

    NASA Astrophysics Data System (ADS)

    Urusan, Ahmet Yucel

    2011-12-01

    In international literature, Coordinate operations is divided into two categories. They are coordinate conversion and coordinate transformation. Coordinates converted from coordinate system A to coordinate system B in the same datum (mean origine, scale and axis directions are same) by coordinate conversion. There are two different datum in coordinate transformation. The basis of each datum to a different coordinate reference system. In Coordinate transformation, coordinates are transformed from coordinate reference system A to coordinate referance system B. Geodetic studies based on physical measurements. Coordinate transformation needs identical points which were measured in each coordinate reference system (A and B). However it is difficult (and need a big reserved budget) to measure in some places like as top of mountain, boundry of countries and seaside. In this study, this sample problem solution was researched. The method of learning which is one of the neural network methods, was used for solution of this problem.

  15. A self-centering active probing technique for kinematic parameter identification and verification of articulated arm coordinate measuring machines

    NASA Astrophysics Data System (ADS)

    Santolaria, J.; Brau, A.; Velázquez, J.; Aguilar, J. J.

    2010-05-01

    A crucial task in the procedure of identifying the parameters of a kinematic model of an articulated arm coordinate measuring machine (AACMM) or robot arm is the process of capturing data. In this paper a capturing data method is analyzed using a self-centering active probe, which drastically reduces the capture time and the required number of positions of the gauge as compared to the usual standard and manufacturer methods. The mathematical models of the self-centering active probe and AACMM are explained, as well as the mathematical model that links the AACMM global reference system to the probe reference system. We present a self-calibration method that will allow us to determine a homogeneous transformation matrix that relates the probe's reference system to the AACMM last reference system from the probing of a single sphere. In addition, a comparison between a self-centering passive probe and self-centering active probe is carried out to show the advantages of the latter in the procedures of kinematic parameter identification and verification of the AACMM.

  16. A three-coordinate system (ecliptic, galactic, ISMF) spectral analysis of heliospheric ENA emissions using CASSINI/INCA measurements

    SciTech Connect

    Dialynas, K.; Krimigis, S. M.; Mitchell, D. G.; Roelof, E. C.; Decker, R. B

    2013-11-20

    In the present study, we use all-sky energy-resolved energetic neutral atom (ENA) maps obtained by the Ion and Neutral CAmera (INCA) instrument on board Cassini that correspond to the time period from 2003 to 2009, in four discrete energy passbands (∼5.4 to ∼55 keV), to investigate the geometrical characteristics of the belt (a broad band of emission in the sky). The heliospheric ENA emissions are mapped in three different coordinate systems (ecliptic, Galactic, and interstellar magnetic field (ISMF)), and spectral analyses are performed to further examine the belt's possible energy dependence. Our conclusions are summarized as follows: (1) the high flux ENA belt identified in the energy range of 8-42 keV is moderately well organized in Galactic coordinates, as the ENA minima appear in the vicinity of the north and south Galactic poles; (2) using minimization criteria ( B · R ∼ 0), the deviation of the ENA emissions from the equator is effectively minimized in a rotated frame, which we interpret as ISMF, where its north pole points toward 190° ecliptic longitude and 15° ecliptic latitude; (3) ENA spectra show a power-law form in energy that can be fitted with a single function presenting higher spectral slopes in the belt region and lower outside (3.4 < γ < 4.4); (4) the spectra are almost indistinguishable between the tail and the nose regions, i.e., no noticeable asymmetry is observed; (5) the consistency of the ENA distributions as a function of latitude among the different INCA channels indicates that the morphology of the belt (peak, width, and structure) is nearly energy independent from 8 keV to 30 keV (minor deviations start to appear at >35 keV); and (6) in the low count rate regions, the long-term ENA count rate profiles do not match the measured cosmic ray profiles, indicating that even the minimum ENA emissions detected by INCA are foreground ENAs.

  17. A Three-coordinate System (Ecliptic, Galactic, ISMF) Spectral Analysis of Heliospheric ENA Emissions Using Cassini/INCA Measurements

    NASA Astrophysics Data System (ADS)

    Dialynas, K.; Krimigis, S. M.; Mitchell, D. G.; Roelof, E. C.; Decker, R. B.

    2013-11-01

    In the present study, we use all-sky energy-resolved energetic neutral atom (ENA) maps obtained by the Ion and Neutral CAmera (INCA) instrument on board Cassini that correspond to the time period from 2003 to 2009, in four discrete energy passbands (~5.4 to ~55 keV), to investigate the geometrical characteristics of the belt (a broad band of emission in the sky). The heliospheric ENA emissions are mapped in three different coordinate systems (ecliptic, Galactic, and interstellar magnetic field (ISMF)), and spectral analyses are performed to further examine the belt's possible energy dependence. Our conclusions are summarized as follows: (1) the high flux ENA belt identified in the energy range of 8-42 keV is moderately well organized in Galactic coordinates, as the ENA minima appear in the vicinity of the north and south Galactic poles; (2) using minimization criteria ( B · R ~ 0), the deviation of the ENA emissions from the equator is effectively minimized in a rotated frame, which we interpret as ISMF, where its north pole points toward 190° ecliptic longitude and 15° ecliptic latitude; (3) ENA spectra show a power-law form in energy that can be fitted with a single function presenting higher spectral slopes in the belt region and lower outside (3.4 < γ < 4.4); (4) the spectra are almost indistinguishable between the tail and the nose regions, i.e., no noticeable asymmetry is observed; (5) the consistency of the ENA distributions as a function of latitude among the different INCA channels indicates that the morphology of the belt (peak, width, and structure) is nearly energy independent from 8 keV to 30 keV (minor deviations start to appear at >35 keV) and (6) in the low count rate regions, the long-term ENA count rate profiles do not match the measured cosmic ray profiles, indicating that even the minimum ENA emissions detected by INCA are foreground ENAs.

  18. An improved method for dynamic measurement of deflections of the vertical based on the maintenance of attitude reference.

    PubMed

    Dai, Dongkai; Wang, Xingshu; Zhan, Dejun; Huang, Zongsheng

    2014-01-01

    A new method for dynamic measurement of deflections of the vertical (DOV) is proposed in this paper. The integration of an inertial navigation system (INS) and global navigation satellite system (GNSS) is constructed to measure the body's attitude with respect to the astronomical coordinates. Simultaneously, the attitude with respect to the geodetic coordinates is initially measured by a star sensor under quasi-static condition and then maintained by the laser gyroscope unit (LGU), which is composed of three gyroscopes in the INS, when the vehicle travels along survey lines. Deflections of the vertical are calculated by using the difference between the attitudes with respect to the geodetic coordinates and astronomical coordinates. Moreover, an algorithm for removing the trend error of the vertical deflections is developed with the aid of Earth Gravitational Model 2008 (EGM2008). In comparison with traditional methods, the new method required less accurate GNSS, because the dynamic acceleration calculation is avoided. The errors of inertial sensors are well resolved in the INS/GNSS integration, which is implemented by a Rauch-Tung-Striebel (RTS) smoother. In addition, a single-axis indexed INS is adopted to improve the observability of the system errors and to restrain the inertial sensor errors. The proposed method is validated by Monte Carlo simulations. The results show that deflections of the vertical can achieve a precision of better than 1″ for a single survey line. The proposed method can be applied to a gravimetry system based on a ground vehicle or ship with a speed lower than 25 m/s. PMID:25192311

  19. An Improved Method for Dynamic Measurement of Deflections of the Vertical Based on the Maintenance of Attitude Reference

    PubMed Central

    Dai, Dongkai; Wang, Xingshu; Zhan, Dejun; Huang, Zongsheng

    2014-01-01

    A new method for dynamic measurement of deflections of the vertical (DOV) is proposed in this paper. The integration of an inertial navigation system (INS) and global navigation satellite system (GNSS) is constructed to measure the body's attitude with respect to the astronomical coordinates. Simultaneously, the attitude with respect to the geodetic coordinates is initially measured by a star sensor under quasi-static condition and then maintained by the laser gyroscope unit (LGU), which is composed of three gyroscopes in the INS, when the vehicle travels along survey lines. Deflections of the vertical are calculated by using the difference between the attitudes with respect to the geodetic coordinates and astronomical coordinates. Moreover, an algorithm for removing the trend error of the vertical deflections is developed with the aid of Earth Gravitational Model 2008 (EGM2008). In comparison with traditional methods, the new method required less accurate GNSS, because the dynamic acceleration calculation is avoided. The errors of inertial sensors are well resolved in the INS/GNSS integration, which is implemented by a Rauch–Tung–Striebel (RTS) smoother. In addition, a single-axis indexed INS is adopted to improve the observability of the system errors and to restrain the inertial sensor errors. The proposed method is validated by Monte Carlo simulations. The results show that deflections of the vertical can achieve a precision of better than 1″ for a single survey line. The proposed method can be applied to a gravimetry system based on a ground vehicle or ship with a speed lower than 25 m/s. PMID:25192311

  20. Beyond the blank slate: routes to learning new coordination patterns depend on the intrinsic dynamics of the learner—experimental evidence and theoretical model

    PubMed Central

    Kostrubiec, Viviane; Zanone, Pier-Giorgio; Fuchs, Armin; Kelso, J. A. Scott

    2012-01-01

    Using an approach that combines experimental studies of bimanual movements to visual stimuli and theoretical modeling, the present paper develops a dynamical account of sensorimotor learning, that is, how new skills are acquired and old ones modified. A significant aspect of our approach is the focus on the individual learner as the basic unit of analysis, in particular the quantification of predispositions and capabilities that the individual learner brings to the learning environment. Such predispositions constitute the learner's behavioral repertoire, captured here theoretically as a dynamical landscape (“intrinsic dynamics”). The learning process is demonstrated to not only lead to a relatively permanent improvement of performance in the required task—the usual outcome—but also to alter the individual's entire repertoire. Changes in the dynamical landscape due to learning are shown to result from two basic mechanisms or “routes”: bifurcation and shift. Which mechanism is selected depends the initial individual repertoire before new learning begins. Both bifurcation and shift mechanisms are accommodated by a dynamical model, a relatively straightforward development of the well-established HKB model of movement coordination. Model simulations show that although environmental or task demands may be met equally well using either mechanism, the bifurcation route results in greater stabilization of the to-be-learned behavior. Thus, stability not (or not only) error is demonstrated to be the basis of selection, both of a new pattern of behavior and the path (smooth shift versus abrupt qualitative change) that learning takes. In line with these results, recent neurophysiological evidence indicates that stability is a relevant feature around which brain activity is organized while an individual performs a coordination task. Finally, we explore the consequences of the dynamical approach to learning for theories of biological change. PMID:22876227

  1. A new device to measure drug-induced changes on reactive and coordinative skills of human performance.

    PubMed

    Linnavuo, M; Ylilääkkölä, P; Mattila, M J; Mäki, M; Seppälä, T

    1987-08-01

    A computerized device for simultaneous measurement of coordinative and reactive skills related to driving was developed and tested in two consecutive trials of psychoactive agents in healthy volunteers. The test system comprises a vehicle, a driving computer (Sinclair QL), and the programming and measurement computer (IBM-PC). The computerized driving programme projects to the colour--TV screen a winding road, and the driver has to keep the car on the road by turning the steering wheel. The driving proceedes at a fixed, fairly rapid rate for 5 min., and the numbers of tracking errors (deviations from the road) as well as the tracking percentage (relative length of the track driven off the road) were computed separately for both halves of the track. During the latter half of the track 60 visual or/and sound stimuli were given in random order, and the driver had to respond or not respond to them by pressing a button or by pushing a foot pedal. The number of reaction errors and the cumulative reaction time were recorded. The programme also provides a histogramme that relates the number of deviations from the road to their duration, enabling a visual judgement of the severity of errors. Matched versions (mirror image, reverse direction) of tracks of varying severity were offered to reduce learning effect during the trial. When testing the device in two placebo-controlled double-blind and cross-over trials, a considerable practice effect on tracking and reaction strategies took place, but after proper training the baselines remained reasonably stable.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2890156

  2. Measurements of radiated elastic wave energy from dynamic tensile cracks

    NASA Technical Reports Server (NTRS)

    Boler, Frances M.

    1990-01-01

    The role of fracture-velocity, microstructure, and fracture-energy barriers in elastic wave radiation during a dynamic fracture was investigated in experiments in which dynamic tensile cracks of two fracture cofigurations of double cantilever beam geometry were propagating in glass samples. The first, referred to as primary fracture, consisted of fractures of intact glass specimens; the second configuration, referred to as secondary fracture, consisted of a refracture of primary fracture specimens which were rebonded with an intermittent pattern of adhesive to produce variations in fracture surface energy along the crack path. For primary fracture cases, measurable elastic waves were generated in 31 percent of the 16 fracture events observed; the condition for radiation of measurable waves appears to be a local abrupt change in the fracture path direction, such as occurs when the fracture intersects a surface flaw. For secondary fractures, 100 percent of events showed measurable elastic waves; in these fractures, the ratio of radiated elastic wave energy in the measured component to fracture surface energy was 10 times greater than for primary fracture.

  3. Airborne Measurement of Ecosystem Carbon Dynamics over Heterogeneous Landscapes

    NASA Astrophysics Data System (ADS)

    Wade, T. J.; Hill, T. C.; Clement, R.; Moncrieff, J.; Disney, M.; Nichol, C. J.; Williams, M. D.

    2009-12-01

    Terrestrial carbon sinks are currently believed to account for the removal and storage of approximately 25% of anthropogenic carbon emissions from the atmosphere. The processes involved are numerous and complex and many feedbacks are at play. The ability to study the dynamics of different ecosystems at scales meaningful to climatic forcing is essential for understanding the key processes involved and identifying crucial sensitivities and thresholds. Airborne platforms with the requisite instrumentation offer the opportunity to directly measure biological processes and atmospheric structures at scales that are not achievable by ground measurements alone. The current generation of small research aircraft such as the University of Edinburgh’s Diamond HK36TTC ECO Dimona present excellent platforms for measurement of both the atmosphere and terrestrial surface. In this study we present results from airborne CO2/H2O flux measuring campaigns in contrasting climatic systems to quantify spatial patterns in ecosystem photosynthesis. Several airborne campaigns were undertaken in Arctic Finland, as part of the Arctic Biosphere Atmosphere Coupling at Multiple Scales (ABACUS) project (2008), and mainland UK as part of the UK Population Biology Network (UKPopNet) 2009 project, to explore the variability in surface CO2 flux across spatial scales larger than captured using conventional ground based eddy covariance. We discuss the application of our aircraft platform as a tool to address the challenge of understanding carbon dynamics within landscapes of heterogeneous vegetation class, terrain and hydrology using complementary datasets acquired from airborne eddy covariance and remote sensing.

  4. Accurate measurements of dynamics and reproducibility in small genetic networks

    PubMed Central

    Dubuis, Julien O; Samanta, Reba; Gregor, Thomas

    2013-01-01

    Quantification of gene expression has become a central tool for understanding genetic networks. In many systems, the only viable way to measure protein levels is by immunofluorescence, which is notorious for its limited accuracy. Using the early Drosophila embryo as an example, we show that careful identification and control of experimental error allows for highly accurate gene expression measurements. We generated antibodies in different host species, allowing for simultaneous staining of four Drosophila gap genes in individual embryos. Careful error analysis of hundreds of expression profiles reveals that less than ∼20% of the observed embryo-to-embryo fluctuations stem from experimental error. These measurements make it possible to extract not only very accurate mean gene expression profiles but also their naturally occurring fluctuations of biological origin and corresponding cross-correlations. We use this analysis to extract gap gene profile dynamics with ∼1 min accuracy. The combination of these new measurements and analysis techniques reveals a twofold increase in profile reproducibility owing to a collective network dynamics that relays positional accuracy from the maternal gradients to the pair-rule genes. PMID:23340845

  5. Measuring and Modeling Exciton Dynamics in Multichromophore Macromolecules

    NASA Astrophysics Data System (ADS)

    Weingarten, Daniel; Hu, Nan; Lacount, Michael; Ferguson, Andrew; Dessau, Daniel; Walba, David; Vandelagemaat, Jao; Lusk, Mark; Rumbles, Garry; Shaheen, Sean

    2014-03-01

    Attaining specific control over the dynamics of exciton movement in organic photovoltaics (OPV) has, thus far, been a largely unachieved goal of OPV design. Such an understanding of exciton transfer dynamics would allow for the design of macromolecules whose energetics, bandgaps, and conformational properties allow for control of exciton flow toward specific reaction site chromophores, potentially enabling non-linear improvements in energy harvesting. To better understand exciton movement we synthesized and characterized a multi-chromophoric macromolecule and measured the dynamics of exciton transfer across coupled chromophores. Our model system is a hexabenzocoronene molecule attached to six oligothiophene. We developed a kinetic model and by fitting it to the decay rates of excited states measured via time-correlated single photon counting, we were able to extract rates for exciton transfer between chromophores. Since this macromolecule exhibits liquid crystalline aggregation behavior, observing the dependence of exciton transfer rates on solution concentration yields an improved understanding of exciton movement within a single molecule as well as the dependence of that transfer process on local material structure.

  6. Measurements of granular flow dynamics with high speed digital images

    SciTech Connect

    Lee, J.

    1994-12-31

    The flow of granular materials is common to many industrial processes. This dissertation suggests and validates image processing algorithms applied to high speed digital images to measure the dynamics (velocity, temperature and volume fraction) of dry granular solids flowing down an inclined chute under the action of gravity. Glass and acrylic particles have been used as granular solids in the experiment. One technique utilizes block matching for spatially averaged velocity measurements of the glass particles. This technique is compared with the velocity measurement using an optic probe which is a conventional granular flow velocity measurement device. The other technique for measuring the velocities of individual acrylic particles is developed with correspondence using a Hopfield network. This technique first locates the positions of particles with pattern recognition techniques, followed by a clustering technique, which produces point patterns. Also, several techniques are compared for particle recognition: synthetic discriminant function (SDF), minimum average correlation energy (MACE) filter, modified minimum average correlation energy (MMACE) filter and variance normalized correlation. The author proposes an MMACE filter which improves generalization of the MACE filter by adjusting the amount of averaged spectrum of training images in the spectrum whitening stages of the MACE filter. Variance normalized correlation is applied to measure the velocity and temperature of flowing glass particles down the inclined chute. The measurements are taken for the steady and wavy flow and qualitatively compared with a theoretical model of granular flow.

  7. Novel dynamic fatigue-testing device: design and measurements

    NASA Astrophysics Data System (ADS)

    Foong, Chee-Hoe; Wiercigroch, Marian; Deans, William F.

    2006-08-01

    The influence of dynamics on a propagating fatigue crack has not been studied experimentally yet mainly due to quasi-static loading from traditional fatigue-testing machines. To overcome this serious drawback, a novel base-excited fatigue-testing device was designed and built to allow measurement of the dynamic responses of a single-edge-notch beam (SENB) under a growing fatigue crack. In this paper, the details of the novel test rig including initial development, modification and instrumentation are given. The experimental time histories obtained for harmonic and chaotic excitations have shown that the fatigue rig is capable of generating a wide range of loading patterns. Moreover, the experimental crack growth curves and features of the fracture surface have confirmed that the rig is capable of inducing proper fatigue cracks.

  8. Sensitivity evaluation of dynamic speckle activity measurements using clustering methods

    SciTech Connect

    Etchepareborda, Pablo; Federico, Alejandro; Kaufmann, Guillermo H.

    2010-07-01

    We evaluate and compare the use of competitive neural networks, self-organizing maps, the expectation-maximization algorithm, K-means, and fuzzy C-means techniques as partitional clustering methods, when the sensitivity of the activity measurement of dynamic speckle images needs to be improved. The temporal history of the acquired intensity generated by each pixel is analyzed in a wavelet decomposition framework, and it is shown that the mean energy of its corresponding wavelet coefficients provides a suited feature space for clustering purposes. The sensitivity obtained by using the evaluated clustering techniques is also compared with the well-known methods of Konishi-Fujii, weighted generalized differences, and wavelet entropy. The performance of the partitional clustering approach is evaluated using simulated dynamic speckle patterns and also experimental data.

  9. High spatial resolution measurements of ram accelerator gas dynamic phenomena

    NASA Technical Reports Server (NTRS)

    Hinkey, J. B.; Burnham, E. A.; Bruckner, A. P.

    1992-01-01

    High spatial resolution experimental tube wall pressure measurements of ram accelerator gas dynamic phenomena are presented. The projectile resembles the centerbody of a ramjet and travels supersonically through a tube filled with a combustible gaseous mixture, with the tube acting as the outer cowling. Pressure data are recorded as the projectile passes by sensors mounted in the tube wall at various locations along the tube. Data obtained by using a special highly instrumented section of tube has allowed the recording of gas dynamic phenomena with a spatial resolution on the order of one tenth the projectile length. High spatial resolution tube wall pressure data from the three regimes of propulsion studied to date (subdetonative, transdetonative, and superdetonative) are presented and reveal the 3D character of the flowfield induced by projectile fins and the canting of the projectile body relative to the tube wall. Also presented for comparison to the experimental data are calculations made with an inviscid, 3D CFD code.

  10. Evaluation of biological cell properties using dynamic indentation measurement.

    PubMed

    Cao, Guoxin; Chandra, Namas

    2010-02-01

    Viscoelastic mechanical properties of biological cells are commonly measured using atomic force microscope (AFM) dynamic indentation with spherical tips. A semiempirical analysis based on numerical simulation is built to determine the cell mechanical properties. It is shown that the existing analysis cannot reflect the accurate values of cell elastic/dynamic modulus due to the effects of substrate, indenter tip size, and cell size. Among these factors, substrate not only increases the true contact radius but also interferes the indentation stress field, which can cause the overestimation of cell moduli. Typically, the substrate effect is much stronger than the other two influences in cell indentation; and, thus, the cell modulii are usually overestimated. It is estimated that the moduli can be overestimated by as high as over 200% using the existing analysis. In order to obtain the accurate properties of cells, correction factors that account for these effects are required in the existing analysis. PMID:20365612

  11. Coordination defects in bismuth-modified arsenic selenide glasses: High-resolution x-ray photoelectron spectroscopy measurements

    SciTech Connect

    Golovchak, Roman; Shpotyuk, Oleh

    2008-05-01

    The possibility of coordination defects formation in Bi-modified chalcogenide glasses is examined by high-resolution x-ray photoelectron spectroscopy. The results provide evidence for the formation of positively charged fourfold coordinated defects on As and Bi sites in glasses with low Bi concentration. At high Bi concentration, mixed As{sub 2}Se{sub 3}-Bi{sub 2}Se{sub 3} nanocrystallites are formed in the investigated Se-rich As-Se glasses.

  12. Blood Sugar Measurement in Zebrafish Reveals Dynamics of Glucose Homeostasis

    PubMed Central

    Eames, Stefani C.; Philipson, Louis H.; Prince, Victoria E.

    2010-01-01

    Abstract The adult zebrafish has the potential to become an important model for diabetes-related research. To realize this potential, small-scale methods for analyzing pancreas function are required. The measurement of blood glucose level is a commonly used method for assessing β-cell function, but the small size of the zebrafish presents challenges both for collecting blood samples and for measuring glucose. We have developed methods for collecting microsamples of whole blood and plasma for the measurement of hematocrit and blood glucose. We demonstrate that two hand-held glucose meters designed for use by human diabetics return valid results with zebrafish blood. Additionally, we present methods for fasting and for performing postprandial glucose and intraperitoneal glucose tolerance tests. We find that the dynamics of zebrafish blood glucose homeostasis are consistent with patterns reported for other omnivorous teleost fish. PMID:20515318

  13. Spatio-temporal co-ordination of RhoA, Rac1 and Cdc42 activation during prototypical edge protrusion and retraction dynamics

    PubMed Central

    Martin, Katrin; Reimann, Andreas; Fritz, Rafael D.; Ryu, Hyunryul; Jeon, Noo Li; Pertz, Olivier

    2016-01-01

    The three canonical Rho GTPases RhoA, Rac1 and Cdc42 co-ordinate cytoskeletal dynamics. Recent studies indicate that all three Rho GTPases are activated at the leading edge of motile fibroblasts, where their activity fluctuates at subminute time and micrometer length scales. Here, we use a microfluidic chip to acutely manipulate fibroblast edge dynamics by applying pulses of platelet-derived growth factor (PDGF) or the Rho kinase inhibitor Y-27632 (which lowers contractility). This induces acute and robust membrane protrusion and retraction events, that exhibit stereotyped cytoskeletal dynamics, allowing us to fairly compare specific morphodynamic states across experiments. Using a novel Cdc42, as well as previously described, second generation RhoA and Rac1 biosensors, we observe distinct spatio-temporal signaling programs that involve all three Rho GTPases, during protrusion/retraction edge dynamics. Our results suggest that Rac1, Cdc42 and RhoA regulate different cytoskeletal and adhesion processes to fine tune the highly plastic edge protrusion/retraction dynamics that power cell motility. PMID:26912264

  14. A general procedure for estimating dynamic displacements using strain measurements and operational modal analysis

    NASA Astrophysics Data System (ADS)

    Skafte, Anders; Aenlle, Manuel L.; Brincker, Rune

    2016-02-01

    Measurement systems are being installed in more and more civil structures with the purpose of monitoring the general dynamic behavior of the structure. The instrumentation is typically done with accelerometers, where experimental frequencies and mode shapes can be identified using modal analysis and used in health monitoring algorithms. But the use of accelerometers is not suitable for all structures. Structures like wind turbine blades and wings on airplanes can be exposed to lightning, which can cause the measurement systems to fail. Structures like these are often equipped with fiber sensors measuring the in-plane deformation. This paper proposes a method in which the displacement mode shapes and responses can be predicted using only strain measurements. The method relies on the newly discovered principle of local correspondence, which states that each experimental mode can be expressed as a unique subset of finite element modes. In this paper the technique is further developed to predict the mode shapes in different states of the structure. Once an estimate of the modes is found, responses can be predicted using the superposition of the modal coordinates weighted by the mode shapes. The method is validated with experimental tests on a scaled model of a two-span bridge installed with strain gauges. Random load was applied to simulate a civil structure under operating condition, and strain mode shapes were identified using operational modal analysis.

  15. Dynamic cerebral autoregulation measured with coherent hemodynamics spectroscopy (CHS)

    NASA Astrophysics Data System (ADS)

    Kainerstorfer, Jana M.; Sassaroli, Angelo; Tgavalekos, Kristen T.; Fantini, Sergio

    2015-03-01

    Coherent Hemodynamics Spectroscopy (CHS) is a novel technique for non-invasive measurements of local microcirculation quantities such as the capillary blood transit times and dynamic autoregulation. The basis of CHS is to measure, for instance with near-infrared spectroscopy (NIRS), peripheral coherent hemodynamic changes that are induced by controlled perturbations in the systemic mean arterial pressure (MAP). In this study, the MAP perturbation was induced by the fast release of two pneumatic cuffs placed around the subject's thighs after they were kept inflated (at 200 mmHg) for two minutes. The resulting transient changes in cerebral oxy- (O) and deoxy- (D) hemoglobin concentrations measured with NIRS on the prefrontal cortex are then described by a novel hemodynamic model, from which quantifiable parameters such as the capillary blood transit time and a cutoff frequency for cerebral autoregulation are obtained. We present results on eleven healthy volunteers in a protocol involving measurements during normal breathing and during hyperventilation, which is known to cause a hypocapnia-induced increase in cerebral autoregulation. The measured capillary transit time was unaffected by hyperventilation (normal breathing: 1.1±0.1 s; hyperventilation: 1.1±0.1 s), whereas the cutoff frequency of autoregulation, which increases for higher autoregulation efficiency, was indeed found to be significantly greater during hyperventilation (normal breathing: 0.017±0.002 Hz; hyperventilation: 0.034±0.005 Hz). These results provide a validation of local cerebral autoregulation measurements with the new technique of CHS.

  16. Statistical prediction of dynamic distortion of inlet flow using minimum dynamic measurement. An application to the Melick statistical method and inlet flow dynamic distortion prediction without RMS measurements

    NASA Technical Reports Server (NTRS)

    Schweikhard, W. G.; Chen, Y. S.

    1986-01-01

    The Melick method of inlet flow dynamic distortion prediction by statistical means is outlined. A hypothetic vortex model is used as the basis for the mathematical formulations. The main variables are identified by matching the theoretical total pressure rms ratio with the measured total pressure rms ratio. Data comparisons, using the HiMAT inlet test data set, indicate satisfactory prediction of the dynamic peak distortion for cases with boundary layer control device vortex generators. A method for the dynamic probe selection was developed. Validity of the probe selection criteria is demonstrated by comparing the reduced-probe predictions with the 40-probe predictions. It is indicated that the the number of dynamic probes can be reduced to as few as two and still retain good accuracy.

  17. A Direct Method for Mapping the Center of Pressure Measured by an Insole Pressure Sensor System to the Shoe's Local Coordinate System.

    PubMed

    Weaver, Brian T; Braman, Jerrod E; Haut, Roger C

    2016-06-01

    A direct method to express the center of pressure (CoP) measured by an insole pressure sensor system (IPSS) into a known coordinate system measured by motion tracking equipment is presented. A custom probe was constructed with reflective markers to allow its tip to be precisely tracked with motion tracking equipment. This probe was utilized to activate individual sensors on an IPSS that was placed in a shoe fitted with reflective markers used to establish a local shoe coordinate system. When pressed onto the IPSS the location of the probe's tip was coincident with the CoP measured by the IPSS (IPSS-CoP). Two separate pushes (i.e., data points) were used to develop vectors in each respective coordinate system. Simple vector mathematics determined the rotational and translational components of the transformation matrix needed to express the IPSS-CoP into the local shoe coordinate system. Validation was performed by comparing IPSS-CoP with an embedded force plate measured CoP (FP-CoP) from data gathered during kinematic trials. Six male subjects stood on an embedded FP and performed anterior/posterior (AP) sway, internal rotation, and external rotation of the body relative to a firmly planted foot. The IPSS-CoP was highly correlated with the FP-CoP for all motions, root mean square errors (RMSRRs) were comparable to other research, and there were no statistical differences between the displacement of the IPSS-CoP and FP-CoP for both the AP and medial/lateral (ML) axes, respectively. The results demonstrated that this methodology could be utilized to determine the transformation variables need to express IPSS-CoP into a known coordinate system measured by motion tracking equipment and that these variables can be determined outside the laboratory anywhere motion tracking equipment is available. PMID:27109294

  18. Prediction and measurement of human pilot dynamic characteristics

    NASA Technical Reports Server (NTRS)

    Hess, Ronald A.; Reedy, James T.

    1988-01-01

    An analytical and experimental study of human pilot control strategies in a manned rotorcraft simulation is described. The task simulated involves a low-speed, constant-altitude maneuvering task in which a head-down display is utilized to allow the pilot to track a moving hover point. The efficacy of the display law driving an 'acceleration symbol' is determined and the manner in which the prediction and measurement of pilot/vehicle dynamics can be made part of man/machine system evaluations is demonstrated.

  19. Spatiotemporal Dynamics of the Wind Velocity from Minisodar Measurement Data

    NASA Astrophysics Data System (ADS)

    Simakhin, V. A.; Cherepanov, O. S.; Shamanaeva, L. G.

    2016-04-01

    The spatiotemporal dynamics of the three wind velocity components in the atmospheric boundary layer is analyzed on the basis of Doppler minisodar measurements. The data were processed and analyzed with the help of robust nonparametric methods based on the weighted maximum likelihood method and classical methods. Distribution laws were obtained for each wind velocity component. There are outliers in the distribution functions; both right and left asymmetry of the distributions are observed. For the x- and ycomponents, the width of the distribution increases as the observation altitude is increased, but the maximum of the distribution function decreases, which is in agreement with the data available in the literature. For the zcomponents the width of the distribution remains practically constant, but the value of the maximum also decreases with altitude. Analysis of the hourly semidiurnal dynamics showed that all three components have maxima in the morning and evening hours. For the y- and z-components the maxima in the evening hours are more strongly expressed than in the morning hours. For the x- and y-components the horizontal wind shear is closely tracked in the evening hours. It is shown that adaptive estimates on the efficiency significantly exceed the classical parametric estimates and allow one to analyze the spatiotemporal dynamics of the wind velocity, and reveal jets and detect wind shears.

  20. Quantitative fluorescent speckle microscopy (QFSM) to measure actin dynamics.

    PubMed

    Mendoza, Michelle C; Besson, Sebastien; Danuser, Gaudenz

    2012-10-01

    Quantitative fluorescent speckle microscopy (QFSM) is a live-cell imaging method to analyze the dynamics of macromolecular assemblies with high spatial and temporal resolution. Its greatest successes were in the analysis of actin filament and adhesion dynamics in the context of cell migration and microtubule dynamics in interphase and the meiotic/mitotic spindle. Here, focus is on the former application to illustrate the procedures of FSM imaging and the computational image processing that extracts quantitative information from these experiments. QFSM is advantageous over other methods because it measures the movement and turnover kinetics of the actin filament (F-actin) network in living cells across the entire field of view. Experiments begin with the microinjection of fluorophore-labeled actin into cells, which generate a low ratio of fluorescently labeled to endogenously unlabeled actin monomers. Spinning disk confocal or wide-field imaging then visualizes fluorophore clusters (two to eight actin monomers) within the assembled F-actin network as speckles. QFSM software identifies and computationally tracks and utilizes the location, appearance, and disappearance of speckles to derive network flows and maps of the rate of filament assembly and disassembly. PMID:23042526

  1. A Coordinated Ice-based and Airborne Snow and Ice Thickness Measurement Campaign on Arctic Sea Ice

    NASA Astrophysics Data System (ADS)

    Richter-Menge, J.; Farrell, S.; Elder, B. C.; Gardner, J. M.; Brozena, J. M.

    2011-12-01

    A rare opportunity presented itself in March 2011 when the Naval Research Laboratory (NRL) and NASA IceBridge teamed with scientists from the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) to coordinate a multi-scale approach to mapping snow depth and sea ice thickness distribution in the Arctic. Ground-truth information for calibration/validation of airborne and CryoSat-2 satellite data were collected near a manned camp deployed in support of the US Navy's Ice Expedition 2011 (ICEX 2011). The ice camp was established at a location approximately 230 km north of Prudhoe Bay, Alaska, at the edge of the perennial ice zone. The suite of measurements was strategically organized around a 9-km-long survey line that covered a wide range of ice types, including refrozen leads, deformed and undeformed first year ice, and multiyear ice. A highly concentrated set of in situ measurements of snow depth and ice thickness were taken along the survey line. Once the survey line was in place, NASA IceBridge flew a dedicated mission along the survey line, collecting data with an instrument suite that included the Airborne Topographic Mapper (ATM), a high precision, airborne scanning laser altimeter; the Digital Mapping System (DMS), nadir-viewing digital camera; and the University of Kansas ultra-wideband Frequency Modulated Continuous Wave (FMCW) snow radar. NRL also flew a dedicated mission over the survey line with complementary airborne radar, laser and photogrammetric sensors (see Brozena et al., this session). These measurements were further leveraged by a series of CryoSat-2 under flights made in the region by the instrumented NRL and NASA planes, as well as US Navy submarine underpasses of the 9-km-long survey line to collect ice draft measurements. This comprehensive suite of data provides the full spectrum of sampling resolutions from satellite, to airborne, to ground-based, to submarine and will allow for a careful determination of

  2. Perfusion measures from dynamic ICG scanning laser ophthalmoscopy

    NASA Astrophysics Data System (ADS)

    Larkin, Sean; Invernizzi, Alessandro; Beecher, David; Staurenghi, Giovanni; Holmes, Tim

    2010-02-01

    Movies acquired from fundus imaging using Indocyanine Green (ICG) and a scanning laser ophthalmoscope provide information for identifying vascular and other retinal abnormalities. Today, the main limitation of this modality is that it requires esoteric training for interpretation. A straightforward interpretation of these movies by objective measurements would aid in eliminating this training barrier. A software program has been developed and tested that produces and visualizes 2D maps of perfusion measures. The program corrects for frame-to-frame misalignment caused by eye motion, including rigid misalignment and warp. The alignment method uses a cross-correlation operation that automatically detects the distance due to motion between adjacent frames. The d-ICG movie is further corrected by removing flicker and vignetting artifacts. Each pixel in the corrected movie sequence is fit with a least-squares spline to yield a smooth intensity temporal profile. From the dynamics of these intensity curves, several perfusion measures are calculated. The most effective of these measures include a metric that represents the amount of time required for a vessel to fill with dye, a metric that represents the diffusion of dye, and a metric that is affected by local blood volume. These metrics are calculated from movies acquired before and after treatment for a neovascular condition. A comparison of these before and after measures may someday provide information to the clinician that helps them to evaluate disease progression and response to treatment.

  3. Laboratory measurements of static and dynamic elastic properties in carbonate

    NASA Astrophysics Data System (ADS)

    Bakhorji, Aiman M.

    S-wave velocities, Gassmann's model consistently over-predict the saturated at low pressure and closely fit the measured velocities at high pressure, whereas, Biot model over-predicts the saturated velocities in most of the studied samples. The strains measured from the vertical and horizontal strain gages are differing by around 27%. The strains over the horizontal axis are higher than the vertical axis suggesting that the majority of the compliant pores and crack-like pores are oriented almost in direction parallel to the length of the sample. The static bulk modulus is always lower than dynamic one for all measured samples. There is no correlation between porosity and static-dynamic ratio. The measured grain bulk modulus obtained from the unjacketed test is reasonably close to the bulk modulus of the constituent mineral phases.

  4. Understanding quantum measurement from the solution of dynamical models

    NASA Astrophysics Data System (ADS)

    Allahverdyan, Armen E.; Balian, Roger; Nieuwenhuizen, Theo M.

    2013-04-01

    The quantum measurement problem, to wit, understanding why a unique outcome is obtained in each individual experiment, is currently tackled by solving models. After an introduction we review the many dynamical models proposed over the years for elucidating quantum measurements. The approaches range from standard quantum theory, relying for instance on quantum statistical mechanics or on decoherence, to quantum-classical methods, to consistent histories and to modifications of the theory. Next, a flexible and rather realistic quantum model is introduced, describing the measurement of the z-component of a spin through interaction with a magnetic memory simulated by a Curie-Weiss magnet, including N≫1 spins weakly coupled to a phonon bath. Initially prepared in a metastable paramagnetic state, it may transit to its up or down ferromagnetic state, triggered by its coupling with the tested spin, so that its magnetization acts as a pointer. A detailed solution of the dynamical equations is worked out, exhibiting several time scales. Conditions on the parameters of the model are found, which ensure that the process satisfies all the features of ideal measurements. Various imperfections of the measurement are discussed, as well as attempts of incompatible measurements. The first steps consist in the solution of the Hamiltonian dynamics for the spin-apparatus density matrix Dˆ(t). Its off-diagonal blocks in a basis selected by the spin-pointer coupling, rapidly decay owing to the many degrees of freedom of the pointer. Recurrences are ruled out either by some randomness of that coupling, or by the interaction with the bath. On a longer time scale, the trend towards equilibrium of the magnet produces a final state Dˆ(t) that involves correlations between the system and the indications of the pointer, thus ensuring registration. Although Dˆ(t) has the form expected for ideal measurements, it only describes a large set of runs. Individual runs are approached by analyzing

  5. Measuring kinetic coefficients by molecular dynamics simulation of zone melting

    NASA Astrophysics Data System (ADS)

    Celestini, Franck; Debierre, Jean-Marc

    2002-04-01

    Molecular dynamics simulations are performed to measure the kinetic coefficient at the solid-liquid interface in pure gold. Results are obtained for the (111), (100), and (110) orientations. Both Au(100) and Au(110) are in reasonable agreement with the law proposed for collision-limited growth. For Au(111), stacking fault domains form, as first reported by Burke, Broughton, and Gilmer [J. Chem. Phys. 89, 1030 (1988)]. The consequence on the kinetics of this interface is dramatic: the measured kinetic coefficient is three times smaller than that predicted by collision-limited growth. Finally, crystallization and melting are found to be always asymmetrical and here again the effect is much more pronounced for the (111) orientation.

  6. Neural measures of dynamic changes in attentive tracking load.

    PubMed

    Drew, Trafton; Horowitz, Todd S; Wolfe, Jeremy M; Vogel, Edward K

    2012-02-01

    In everyday life, we often need to track several objects simultaneously, a task modeled in the laboratory using the multiple-object tracking (MOT) task [Pylyshyn, Z., & Storm, R. W. Tracking multiple independent targets: Evidence for a parallel tracking mechanism. Spatial Vision, 3, 179-197, 1988]. Unlike MOT, however, in life, the set of relevant targets tends to be fluid and change over time. Humans are quite adept at "juggling" targets in and out of the target set [Wolfe, J. M., Place, S. S., & Horowitz, T. S. Multiple object juggling: Changing what is tracked during extended MOT. Psychonomic Bulletin & Review, 14, 344-349, 2007]. Here, we measured the neural underpinnings of this process using electrophysiological methods. Vogel and colleagues [McCollough, A. W., Machizawa, M. G., & Vogel, E. K. Electrophysiological measures of maintaining representations in visual working memory. Cortex, 43, 77-94, 2007; Vogel, E. K., McCollough, A. W., & Machizawa, M. G. Neural measures reveal individual differences in controlling access to working memory. Nature, 438, 500-503, 2005; Vogel, E. K., & Machizawa, M. G. Neural activity predicts individual differences in visual working memory capacity. Nature, 428, 748-751, 2004] have shown that the amplitude of a sustained lateralized negativity, contralateral delay activity (CDA) indexes the number of items held in visual working memory. Drew and Vogel [Drew, T., & Vogel, E. K. Neural measures of individual differences in selecting and tracking multiple moving objects. Journal of Neuroscience, 28, 4183-4191, 2008] showed that the CDA also indexes the number of items being tracking a standard MOT task. In the current study, we set out to determine whether the CDA is a signal that merely represents the number of objects that are attended during a trial or a dynamic signal capable of reflecting on-line changes in tracking load during a single trial. By measuring the response to add or drop cues, we were able to observe dynamic

  7. Z-correction, a method for achieving ultraprecise self-calibration on large area coordinate measurement machines for photomasks

    NASA Astrophysics Data System (ADS)

    Ekberg, Peter; Stiblert, Lars; Mattsson, Lars

    2014-05-01

    High-quality photomasks are a prerequisite for the production of flat panel TVs, tablets and other kinds of high-resolution displays. During the past years, the resolution demand has become more and more accelerated, and today, the high-definition standard HD, 1920 × 1080 pixels2, is well established, and already the next-generation so-called ultra-high-definition UHD or 4K display is entering the market. Highly advanced mask writers are used to produce the photomasks needed for the production of such displays. The dimensional tolerance in X and Y on absolute pattern placement on these photomasks, with sizes of square meters, has been in the range of 200-300 nm (3σ), but is now on the way to be <150 nm (3σ). To verify these photomasks, 2D ultra-precision coordinate measurement machines are used with even tighter tolerance requirements. The metrology tool MMS15000 is today the world standard tool used for the verification of large area photomasks. This paper will present a method called Z-correction that has been developed for the purpose of improving the absolute X, Y placement accuracy of features on the photomask in the writing process. However, Z-correction is also a prerequisite for achieving X and Y uncertainty levels <90 nm (3σ) in the self-calibration process of the MMS15000 stage area of 1.4 × 1.5 m2. When talking of uncertainty specifications below 200 nm (3σ) of such a large area, the calibration object used, here an 8-16 mm thick quartz plate of size approximately a square meter, cannot be treated as a rigid body. The reason for this is that the absolute shape of the plate will be affected by gravity and will therefore not be the same at different places on the measurement machine stage when it is used in the self-calibration process. This mechanical deformation will stretch or compress the top surface (i.e. the image side) of the plate where the pattern resides, and therefore spatially deform the mask pattern in the X- and Y-directions. Errors due

  8. A technique for measuring dynamic friction coefficient under impact loading

    NASA Astrophysics Data System (ADS)

    Lin, Y. L.; Qin, J. G.; Chen, R.; Zhao, P. D.; Lu, F. Y.

    2014-09-01

    We develop a novel setup based on the split Hopkinson pressure bar technique to test the dynamic friction coefficient under impact loading. In the setup, the major improvement is that the end of the incident bar near the specimen is wedge-shaped, which results in a combined compressive and shear loading applied to the specimen. In fact, the shear loading is caused by the interfacial friction between specimen and bars. Therefore, when the two loading force histories are measured, the friction coefficient histories can be calculated without any assumptions and theoretical derivations. The geometry of the friction pairs is simple, and can be either cuboid or cylindrical. Regarding the measurements, two quartz transducers are used to directly record the force histories, and an optical apparatus is designed to test the interfacial slip movement. By using the setup, the dynamic friction coefficient of PTFE/aluminum 7075 friction pairs was tested. The time resolved dynamic friction coefficient and slip movement histories were achieved. The results show that the friction coefficient changes during the loading process, the average data of the relatively stable flat plateau section of the friction coefficient curves is 0.137, the maximum normal pressure is 52 MPa, the maximum relative slip velocity is 1.5 m/s, and the acceleration is 8400 m2/s. Furthermore, the friction test was simulated using an explicit FEM code LS-DYNA. The simulation results showed that the constant pressure and slip velocity can both be obtained with a wide flat plateau incident pulse. For some special friction pairs, normal pressure up to a few hundred MPa, interfacial slip velocities up to 10 m/s, and slip movement up to centimeter-level can be expected.

  9. A technique for measuring dynamic friction coefficient under impact loading.

    PubMed

    Lin, Y L; Qin, J G; Chen, R; Zhao, P D; Lu, F Y

    2014-09-01

    We develop a novel setup based on the split Hopkinson pressure bar technique to test the dynamic friction coefficient under impact loading. In the setup, the major improvement is that the end of the incident bar near the specimen is wedge-shaped, which results in a combined compressive and shear loading applied to the specimen. In fact, the shear loading is caused by the interfacial friction between specimen and bars. Therefore, when the two loading force histories are measured, the friction coefficient histories can be calculated without any assumptions and theoretical derivations. The geometry of the friction pairs is simple, and can be either cuboid or cylindrical. Regarding the measurements, two quartz transducers are used to directly record the force histories, and an optical apparatus is designed to test the interfacial slip movement. By using the setup, the dynamic friction coefficient of PTFE/aluminum 7075 friction pairs was tested. The time resolved dynamic friction coefficient and slip movement histories were achieved. The results show that the friction coefficient changes during the loading process, the average data of the relatively stable flat plateau section of the friction coefficient curves is 0.137, the maximum normal pressure is 52 MPa, the maximum relative slip velocity is 1.5 m/s, and the acceleration is 8400 m(2)/s. Furthermore, the friction test was simulated using an explicit FEM code LS-DYNA. The simulation results showed that the constant pressure and slip velocity can both be obtained with a wide flat plateau incident pulse. For some special friction pairs, normal pressure up to a few hundred MPa, interfacial slip velocities up to 10 m/s, and slip movement up to centimeter-level can be expected. PMID:25273746

  10. Dynamic Pressure Probes Developed for Supersonic Flow-Field Measurements

    NASA Technical Reports Server (NTRS)

    Porro, A. Robert

    2001-01-01

    A series of dynamic flow-field pressure probes were developed for use in large-scale supersonic wind tunnels at the NASA Glenn Research Center. These flow-field probes include pitot and static pressure probes that can capture fast-acting flow-field pressure transients occurring on a millisecond timescale. The pitot and static probes can be used to determine local Mach number time histories during a transient event. The flow-field pressure probe contains four major components: 1) Static pressure aerodynamic tip; 2) Pressure-sensing cartridge assembly; 3) Pitot pressure aerodynamic tip; 4) Mounting stem. This modular design allows for a variety of probe tips to be used for a specific application. Here, the focus is on flow-field pressure measurements in supersonic flows, so we developed a cone-cylinder static pressure tip and a pitot pressure tip. Alternatively, probe tips optimized for subsonic and transonic flows could be used with this design. The pressure-sensing cartridge assembly allows the simultaneous measurement of steady-state and transient pressure which allows continuous calibration of the dynamic pressure transducer.

  11. Technology coordination

    NASA Technical Reports Server (NTRS)

    Hartman, Steven

    1992-01-01

    Viewgraphs on technology coordination are provided. Topics covered include: technology coordination process to date; goals; how the Office of Aeronautics and Space Technology (OAST) can support the Office of Space Science and Applications (OSSA); how OSSA can support OAST; steps to technology transfer; and recommendations.

  12. MEASURING THE MASS OF 4UO900-40 DYNAMICALLY

    NASA Technical Reports Server (NTRS)

    Dolan, J. F.; Etzel, Paul B.; Boyd, Patricia T.

    2006-01-01

    Accurate measurements of neutron star masses are needed to constrain the equation of state of neutron star matter - of importance to both particle physics and the astrophysics of neutron stars - and to identify the evolutionary track of the progenitor stars that form neutron stars. The best measured values of the mass of 4UO900-40 (= Vela XR-l), 1.86 +/- 0.16 Msun (Barziv et al. 2001) and 1.93 +/- 0.20 Msun (Abubekerov et al. 2004), make it a leading candidate for the most massive neutron star known. The direct relationship between the maximum mass of neutron stars and the equation of state of ultra-dense matter makes 4UO900-40 an important neutron star mass to determine accurately. The confidence interval on previous mass estimates, obtained from observations that include parameters determined by non-dynamical methods, are not small enough to significantly restrict possible equations of state. We describe here a purely dynamical method for determining the mass of 4UO900-40, an X-ray pulsar, using the reprocessed UV pulses emitted by its BO.5Ib companion. One can derive the instantaneous radial velocity of each component by simultaneous X-ray and UV observations at the two quadratures of the system. The Doppler shift caused by the primary's rotational velocity and the illumination pattern of the X-rays on the primary, two of the three principal contributors to the uncertainty on the derived mass of the neutron star, almost exactly cancel by symmetry in this method. A heuristic measurement of the mass of 4UO900-40 using observations obtained previously with the High Speed Photometer on HST is given in Appendix A.

  13. Developing a New System to Measure Outcomes in a Service Coordination Program for Youth with Severe Emotional Disturbance

    ERIC Educational Resources Information Center

    Shannon, Lisa M.; Walker, Robert; Blevins, Michele

    2009-01-01

    This paper presents information on re-developing an outcome evaluation for a state-funded program providing service coordination utilizing wraparound to youth with severe emotional disturbance (SED) and their families. Originally funded by the Robert Wood Johnson Foundation, the Kentucky IMPACT program has existed statewide since 1990. Changing…

  14. Structural anomaly and dynamic heterogeneity in cycloether/water binary mixtures: Signatures from composition dependent dynamic fluorescence measurements and computer simulations

    NASA Astrophysics Data System (ADS)

    Indra, Sandipa; Guchhait, Biswajit; Biswas, Ranjit

    2016-03-01

    We have performed steady state UV-visible absorption and time-resolved fluorescence measurements and computer simulations to explore the cosolvent mole fraction induced changes in structural and dynamical properties of water/dioxane (Diox) and water/tetrahydrofuran (THF) binary mixtures. Diox is a quadrupolar solvent whereas THF is a dipolar one although both are cyclic molecules and represent cycloethers. The focus here is on whether these cycloethers can induce stiffening and transition of water H-bond network structure and, if they do, whether such structural modification differentiates the chemical nature (dipolar or quadrupolar) of the cosolvent molecules. Composition dependent measured fluorescence lifetimes and rotation times of a dissolved dipolar solute (Coumarin 153, C153) suggest cycloether mole-fraction (XTHF/Diox) induced structural transition for both of these aqueous binary mixtures in the 0.1 ≤ XTHF/Diox ≤ 0.2 regime with no specific dependence on the chemical nature. Interestingly, absorption measurements reveal stiffening of water H-bond structure in the presence of both the cycloethers at a nearly equal mole-fraction, XTHF/Diox ˜ 0.05. Measurements near the critical solution temperature or concentration indicate no role for the solution criticality on the anomalous structural changes. Evidences for cycloether aggregation at very dilute concentrations have been found. Simulated radial distribution functions reflect abrupt changes in respective peak heights at those mixture compositions around which fluorescence measurements revealed structural transition. Simulated water coordination numbers (for a dissolved C153) and number of H-bonds also exhibit minima around these cosolvent concentrations. In addition, several dynamic heterogeneity parameters have been simulated for both the mixtures to explore the effects of structural transition and chemical nature of cosolvent on heterogeneous dynamics of these systems. Simulated four-point dynamic

  15. Structural anomaly and dynamic heterogeneity in cycloether/water binary mixtures: Signatures from composition dependent dynamic fluorescence measurements and computer simulations.

    PubMed

    Indra, Sandipa; Guchhait, Biswajit; Biswas, Ranjit

    2016-03-28

    We have performed steady state UV-visible absorption and time-resolved fluorescence measurements and computer simulations to explore the cosolvent mole fraction induced changes in structural and dynamical properties of water/dioxane (Diox) and water/tetrahydrofuran (THF) binary mixtures. Diox is a quadrupolar solvent whereas THF is a dipolar one although both are cyclic molecules and represent cycloethers. The focus here is on whether these cycloethers can induce stiffening and transition of water H-bond network structure and, if they do, whether such structural modification differentiates the chemical nature (dipolar or quadrupolar) of the cosolvent molecules. Composition dependent measured fluorescence lifetimes and rotation times of a dissolved dipolar solute (Coumarin 153, C153) suggest cycloether mole-fraction (X(THF)/Diox) induced structural transition for both of these aqueous binary mixtures in the 0.1 ≤ X(THF)/Diox ≤ 0.2 regime with no specific dependence on the chemical nature. Interestingly, absorption measurements reveal stiffening of water H-bond structure in the presence of both the cycloethers at a nearly equal mole-fraction, X(THF)/Diox ∼ 0.05. Measurements near the critical solution temperature or concentration indicate no role for the solution criticality on the anomalous structural changes. Evidences for cycloether aggregation at very dilute concentrations have been found. Simulated radial distribution functions reflect abrupt changes in respective peak heights at those mixture compositions around which fluorescence measurements revealed structural transition. Simulated water coordination numbers (for a dissolved C153) and number of H-bonds also exhibit minima around these cosolvent concentrations. In addition, several dynamic heterogeneity parameters have been simulated for both the mixtures to explore the effects of structural transition and chemical nature of cosolvent on heterogeneous dynamics of these systems. Simulated four

  16. Coordinated Regulation of TIP60 and Poly(ADP-Ribose) Polymerase 1 in Damaged-Chromatin Dynamics.

    PubMed

    Ikura, Masae; Furuya, Kanji; Fukuto, Atsuhiko; Matsuda, Ryo; Adachi, Jun; Matsuda, Tomonari; Kakizuka, Akira; Ikura, Tsuyoshi

    2016-05-15

    The dynamic exchange of histones alleviates the nucleosome barrier and simultaneously facilitates various aspects of cellular DNA metabolism, such as DNA repair and transcription. In response to DNA damage, the acetylation of Lys5 in the histone variant H2AX, catalyzed by TIP60, plays a key role in promoting histone exchange; however, the detailed molecular mechanism still is unclear. Here, we show that the TIP60 complex includes poly(ADP-ribose) polymerase 1 (PARP-1). PARP-1 is required for the rapid exchange of H2AX on chromatin at DNA damage sites. It is known that PARP-1 binds dynamically to damaged chromatin and is crucial for the subsequent recruitment of other repair factors, and its auto-poly(ADP-ribosyl)ation is required for the dynamics. We also show that the acetylation of histone H2AX at Lys5 by TIP60, but not the phosphorylation of H2AX, is required for the ADP-ribosylation activity of PARP-1 and its dynamic binding to damaged chromatin. Our results indicate the reciprocal regulation of K5 acetylation of H2AX and PARP-1, which could modulate the chromatin structure to facilitate DNA metabolism at damage sites. This could explain the rather undefined roles of PARP-1 in various DNA damage responses. PMID:26976643

  17. Dynamics and particle image velocimetry measurements of miniaturized thermoacoustic refrigerators

    NASA Astrophysics Data System (ADS)

    El-Gendy, Husam El-Deen Mohamad

    This research deals with the design and characterization of the dynamics of miniaturized thermoacoustic refrigerators (in the audible frequency range ˜ 4000 Hz) using a random array of cotton wool as the stack and a commercial piezoelectric loudspeaker as the acoustic driver. Also of primary interest is the optimization of the refrigerator by investigating the factors affecting its performance such as the stack configuration, the acoustic drive ratio, the acoustic pressure and the mean pressure in the refrigerator. Experimental measurements of cooling power, and stray heat leaks were conducted. Digital particle image velocimetry (DPIV) was used to study the acoustic flow field in the refrigerator and to correlate measurements using PIV to the characteristic acoustic measurements. A temperature difference between the refrigerator's cold and hot heat exchangers of 13°C was obtained under optimized experimental conditions. Air at atmospheric pressure was used as the working gas, and an electric power to the acoustic driver of 2 W produced 159 dB of sound, which pumped heat by the stack. Higher sound levels would raise the performance. Results showed that the cotton stack performs well at atmospheric pressure rather than higher mean pressures where nonlinear and viscous losses affect its performance. PIV measurements, such as imaged velocity fields and gas flows, showed an excellent correlation with the acoustic pressure measurements in the refrigerator. Extreme care was taken, by investigating different PIV parameters, to fulfill the conditions that distinguish between the oscillating first-order velocity field, such as the acoustic particle velocity, and the second-order nonoscillating (steady state) fields, such as acoustic streaming. Results also showed that Rayleigh streaming, produced by and superimposed on, the oscillating particle velocity, is one of the effects affecting the performance of the refrigerator, where the time it takes the streaming to be in the

  18. Measurement of dynamic surface tension by mechanically vibrated sessile droplets.

    PubMed

    Iwata, Shuichi; Yamauchi, Satoko; Yoshitake, Yumiko; Nagumo, Ryo; Mori, Hideki; Kajiya, Tadashi

    2016-04-01

    We developed a novel method for measuring the dynamic surface tension of liquids using mechanically vibrated sessile droplets. Under continuous mechanical vibration, the shape of the deformed droplet was fitted by numerical analysis, taking into account the force balance at the drop surface and the momentum equation. The surface tension was determined by optimizing four parameters: the surface tension, the droplet's height, the radius of the droplet-substrate contact area, and the horizontal symmetrical position of the droplet. The accuracy and repeatability of the proposed method were confirmed using drops of distilled water as well as viscous aqueous glycerol solutions. The vibration frequency had no influence on surface tension in the case of pure liquids. However, for water-soluble surfactant solutions, the dynamic surface tension gradually increased with vibration frequency, which was particularly notable for low surfactant concentrations slightly below the critical micelle concentration. This frequency dependence resulted from the competition of two mechanisms at the drop surface: local surface deformation and surfactant transport towards the newly generated surface. PMID:27131706

  19. Measurement of dynamic surface tension by mechanically vibrated sessile droplets

    NASA Astrophysics Data System (ADS)

    Iwata, Shuichi; Yamauchi, Satoko; Yoshitake, Yumiko; Nagumo, Ryo; Mori, Hideki; Kajiya, Tadashi

    2016-04-01

    We developed a novel method for measuring the dynamic surface tension of liquids using mechanically vibrated sessile droplets. Under continuous mechanical vibration, the shape of the deformed droplet was fitted by numerical analysis, taking into account the force balance at the drop surface and the momentum equation. The surface tension was determined by optimizing four parameters: the surface tension, the droplet's height, the radius of the droplet-substrate contact area, and the horizontal symmetrical position of the droplet. The accuracy and repeatability of the proposed method were confirmed using drops of distilled water as well as viscous aqueous glycerol solutions. The vibration frequency had no influence on surface tension in the case of pure liquids. However, for water-soluble surfactant solutions, the dynamic surface tension gradually increased with vibration frequency, which was particularly notable for low surfactant concentrations slightly below the critical micelle concentration. This frequency dependence resulted from the competition of two mechanisms at the drop surface: local surface deformation and surfactant transport towards the newly generated surface.

  20. Methodological aspects of EEG and body dynamics measurements during motion

    PubMed Central

    Reis, Pedro M. R.; Hebenstreit, Felix; Gabsteiger, Florian; von Tscharner, Vinzenz; Lochmann, Matthias

    2014-01-01

    EEG involves the recording, analysis, and interpretation of voltages recorded on the human scalp which originate from brain gray matter. EEG is one of the most popular methods of studying and understanding the processes that underlie behavior. This is so, because EEG is relatively cheap, easy to wear, light weight and has high temporal resolution. In terms of behavior, this encompasses actions, such as movements that are performed in response to the environment. However, there are methodological difficulties which can occur when recording EEG during movement such as movement artifacts. Thus, most studies about the human brain have examined activations during static conditions. This article attempts to compile and describe relevant methodological solutions that emerged in order to measure body and brain dynamics during motion. These descriptions cover suggestions on how to avoid and reduce motion artifacts, hardware, software and techniques for synchronously recording EEG, EMG, kinematics, kinetics, and eye movements during motion. Additionally, we present various recording systems, EEG electrodes, caps and methods for determinating real/custom electrode positions. In the end we will conclude that it is possible to record and analyze synchronized brain and body dynamics related to movement or exercise tasks. PMID:24715858